// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Linux INET6 implementation
* FIB front-end.
*
* Authors:
* Pedro Roque <[email protected]>
*/
/* Changes:
*
* YOSHIFUJI Hideaki @USAGI
* reworked default router selection.
* - respect outgoing interface
* - select from (probably) reachable routers (i.e.
* routers in REACHABLE, STALE, DELAY or PROBE states).
* - always select the same router if it is (probably)
* reachable. otherwise, round-robin the list.
* Ville Nuorvala
* Fixed routing subtrees.
*/
#define pr_fmt(fmt) "IPv6: " fmt
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/types.h>
#include <linux/times.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/route.h>
#include <linux/netdevice.h>
#include <linux/in6.h>
#include <linux/mroute6.h>
#include <linux/init.h>
#include <linux/if_arp.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/nsproxy.h>
#include <linux/slab.h>
#include <linux/jhash.h>
#include <linux/siphash.h>
#include <net/net_namespace.h>
#include <net/snmp.h>
#include <net/ipv6.h>
#include <net/ip6_fib.h>
#include <net/ip6_route.h>
#include <net/ndisc.h>
#include <net/addrconf.h>
#include <net/tcp.h>
#include <linux/rtnetlink.h>
#include <net/dst.h>
#include <net/dst_metadata.h>
#include <net/xfrm.h>
#include <net/netevent.h>
#include <net/netlink.h>
#include <net/rtnh.h>
#include <net/lwtunnel.h>
#include <net/ip_tunnels.h>
#include <net/l3mdev.h>
#include <net/ip.h>
#include <linux/uaccess.h>
#include <linux/btf_ids.h>
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
#endif
static int ip6_rt_type_to_error(u8 fib6_type);
#define CREATE_TRACE_POINTS
#include <trace/events/fib6.h>
EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup);
#undef CREATE_TRACE_POINTS
enum rt6_nud_state {
RT6_NUD_FAIL_HARD = -3,
RT6_NUD_FAIL_PROBE = -2,
RT6_NUD_FAIL_DO_RR = -1,
RT6_NUD_SUCCEED = 1
};
INDIRECT_CALLABLE_SCOPE
struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie);
static unsigned int ip6_default_advmss(const struct dst_entry *dst);
INDIRECT_CALLABLE_SCOPE
unsigned int ip6_mtu(const struct dst_entry *dst);
static void ip6_negative_advice(struct sock *sk,
struct dst_entry *dst);
static void ip6_dst_destroy(struct dst_entry *);
static void ip6_dst_ifdown(struct dst_entry *,
struct net_device *dev);
static void ip6_dst_gc(struct dst_ops *ops);
static int ip6_pkt_discard(struct sk_buff *skb);
static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
static int ip6_pkt_prohibit(struct sk_buff *skb);
static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb);
static void ip6_link_failure(struct sk_buff *skb);
static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
struct sk_buff *skb, u32 mtu,
bool confirm_neigh);
static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
struct sk_buff *skb);
static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
int strict);
static size_t rt6_nlmsg_size(struct fib6_info *f6i);
static int rt6_fill_node(struct net *net, struct sk_buff *skb,
struct fib6_info *rt, struct dst_entry *dst,
struct in6_addr *dest, struct in6_addr *src,
int iif, int type, u32 portid, u32 seq,
unsigned int flags);
static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
const struct in6_addr *daddr,
const struct in6_addr *saddr);
#ifdef CONFIG_IPV6_ROUTE_INFO
static struct fib6_info *rt6_add_route_info(struct net *net,
const struct in6_addr *prefix, int prefixlen,
const struct in6_addr *gwaddr,
struct net_device *dev,
unsigned int pref);
static struct fib6_info *rt6_get_route_info(struct net *net,
const struct in6_addr *prefix, int prefixlen,
const struct in6_addr *gwaddr,
struct net_device *dev);
#endif
struct uncached_list {
spinlock_t lock;
struct list_head head;
};
static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
void rt6_uncached_list_add(struct rt6_info *rt)
{
struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list);
rt->dst.rt_uncached_list = ul;
spin_lock_bh(&ul->lock);
list_add_tail(&rt->dst.rt_uncached, &ul->head);
spin_unlock_bh(&ul->lock);
}
void rt6_uncached_list_del(struct rt6_info *rt)
{
if (!list_empty(&rt->dst.rt_uncached)) {
struct uncached_list *ul = rt->dst.rt_uncached_list;
spin_lock_bh(&ul->lock);
list_del_init(&rt->dst.rt_uncached);
spin_unlock_bh(&ul->lock);
}
}
static void rt6_uncached_list_flush_dev(struct net_device *dev)
{
int cpu;
for_each_possible_cpu(cpu) {
struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
struct rt6_info *rt, *safe;
if (list_empty(&ul->head))
continue;
spin_lock_bh(&ul->lock);
list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) {
struct inet6_dev *rt_idev = rt->rt6i_idev;
struct net_device *rt_dev = rt->dst.dev;
bool handled = false;
if (rt_idev && rt_idev->dev == dev) {
rt->rt6i_idev = in6_dev_get(blackhole_netdev);
in6_dev_put(rt_idev);
handled = true;
}
if (rt_dev == dev) {
rt->dst.dev = blackhole_netdev;
netdev_ref_replace(rt_dev, blackhole_netdev,
&rt->dst.dev_tracker,
GFP_ATOMIC);
handled = true;
}
if (handled)
list_del_init(&rt->dst.rt_uncached);
}
spin_unlock_bh(&ul->lock);
}
}
static inline const void *choose_neigh_daddr(const struct in6_addr *p,
struct sk_buff *skb,
const void *daddr)
{
if (!ipv6_addr_any(p))
return (const void *) p;
else if (skb)
return &ipv6_hdr(skb)->daddr;
return daddr;
}
struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
struct net_device *dev,
struct sk_buff *skb,
const void *daddr)
{
struct neighbour *n;
daddr = choose_neigh_daddr(gw, skb, daddr);
n = __ipv6_neigh_lookup(dev, daddr);
if (n)
return n;
n = neigh_create(&nd_tbl, daddr, dev);
return IS_ERR(n) ? NULL : n;
}
static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst,
struct sk_buff *skb,
const void *daddr)
{
const struct rt6_info *rt = dst_rt6_info(dst);
return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any),
dst->dev, skb, daddr);
}
static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr)
{
const struct rt6_info *rt = dst_rt6_info(dst);
struct net_device *dev = dst->dev;
daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr);
if (!daddr)
return;
if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
return;
if (ipv6_addr_is_multicast((const struct in6_addr *)daddr))
return;
__ipv6_confirm_neigh(dev, daddr);
}
static struct dst_ops ip6_dst_ops_template = {
.family = AF_INET6,
.gc = ip6_dst_gc,
.gc_thresh = 1024,
.check = ip6_dst_check,
.default_advmss = ip6_default_advmss,
.mtu = ip6_mtu,
.cow_metrics = dst_cow_metrics_generic,
.destroy = ip6_dst_destroy,
.ifdown = ip6_dst_ifdown,
.negative_advice = ip6_negative_advice,
.link_failure = ip6_link_failure,
.update_pmtu = ip6_rt_update_pmtu,
.redirect = rt6_do_redirect,
.local_out = __ip6_local_out,
.neigh_lookup = ip6_dst_neigh_lookup,
.confirm_neigh = ip6_confirm_neigh,
};
static struct dst_ops ip6_dst_blackhole_ops = {
.family = AF_INET6,
.default_advmss = ip6_default_advmss,
.neigh_lookup = ip6_dst_neigh_lookup,
.check = ip6_dst_check,
.destroy = ip6_dst_destroy,
.cow_metrics = dst_cow_metrics_generic,
.update_pmtu = dst_blackhole_update_pmtu,
.redirect = dst_blackhole_redirect,
.mtu = dst_blackhole_mtu,
};
static const u32 ip6_template_metrics[RTAX_MAX] = {
[RTAX_HOPLIMIT - 1] = 0,
};
static const struct fib6_info fib6_null_entry_template = {
.fib6_flags = (RTF_REJECT | RTF_NONEXTHOP),
.fib6_protocol = RTPROT_KERNEL,
.fib6_metric = ~(u32)0,
.fib6_ref = REFCOUNT_INIT(1),
.fib6_type = RTN_UNREACHABLE,
.fib6_metrics = (struct dst_metrics *)&dst_default_metrics,
};
static const struct rt6_info ip6_null_entry_template = {
.dst = {
.__rcuref = RCUREF_INIT(1),
.__use = 1,
.obsolete = DST_OBSOLETE_FORCE_CHK,
.error = -ENETUNREACH,
.input = ip6_pkt_discard,
.output = ip6_pkt_discard_out,
},
.rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP),
};
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
static const struct rt6_info ip6_prohibit_entry_template = {
.dst = {
.__rcuref = RCUREF_INIT(1),
.__use = 1,
.obsolete = DST_OBSOLETE_FORCE_CHK,
.error = -EACCES,
.input = ip6_pkt_prohibit,
.output = ip6_pkt_prohibit_out,
},
.rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP),
};
static const struct rt6_info ip6_blk_hole_entry_template = {
.dst = {
.__rcuref = RCUREF_INIT(1),
.__use = 1,
.obsolete = DST_OBSOLETE_FORCE_CHK,
.error = -EINVAL,
.input = dst_discard,
.output = dst_discard_out,
},
.rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP),
};
#endif
static void rt6_info_init(struct rt6_info *rt)
{
memset_after(rt, 0, dst);
}
/* allocate dst with ip6_dst_ops */
struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
int flags)
{
struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
DST_OBSOLETE_FORCE_CHK, flags);
if (rt) {
rt6_info_init(rt);
atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
}
return rt;
}
EXPORT_SYMBOL(ip6_dst_alloc);
static void ip6_dst_destroy(struct dst_entry *dst)
{
struct rt6_info *rt = dst_rt6_info(dst);
struct fib6_info *from;
struct inet6_dev *idev;
ip_dst_metrics_put(dst);
rt6_uncached_list_del(rt);
idev = rt->rt6i_idev;
if (idev) {
rt->rt6i_idev = NULL;
in6_dev_put(idev);
}
from = unrcu_pointer(xchg(&rt->from, NULL));
fib6_info_release(from);
}
static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
{
struct rt6_info *rt = dst_rt6_info(dst);
struct inet6_dev *idev = rt->rt6i_idev;
if (idev && idev->dev != blackhole_netdev) {
struct inet6_dev *blackhole_idev = in6_dev_get(blackhole_netdev);
if (blackhole_idev) {
rt->rt6i_idev = blackhole_idev;
in6_dev_put(idev);
}
}
}
static bool __rt6_check_expired(const struct rt6_info *rt)
{
if (rt->rt6i_flags & RTF_EXPIRES)
return time_after(jiffies, rt->dst.expires);
else
return false;
}
static bool rt6_check_expired(const struct rt6_info *rt)
{
struct fib6_info *from;
from = rcu_dereference(rt->from);
if (rt->rt6i_flags & RTF_EXPIRES) {
if (time_after(jiffies, rt->dst.expires))
return true;
} else if (from) {
return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
fib6_check_expired(from);
}
return false;
}
void fib6_select_path(const struct net *net, struct fib6_result *res,
struct flowi6 *fl6, int oif, bool have_oif_match,
const struct sk_buff *skb, int strict)
{
struct fib6_info *sibling, *next_sibling;
struct fib6_info *match = res->f6i;
if (!match->nh && (!match->fib6_nsiblings || have_oif_match))
goto out;
if (match->nh && have_oif_match && res->nh)
return;
if (skb)
IP6CB(skb)->flags |= IP6SKB_MULTIPATH;
/* We might have already computed the hash for ICMPv6 errors. In such
* case it will always be non-zero. Otherwise now is the time to do it.
*/
if (!fl6->mp_hash &&
(!match->nh || nexthop_is_multipath(match->nh)))
fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
if (unlikely(match->nh)) {
nexthop_path_fib6_result(res, fl6->mp_hash);
return;
}
if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
goto out;
list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
fib6_siblings) {
const struct fib6_nh *nh = sibling->fib6_nh;
int nh_upper_bound;
nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
if (fl6->mp_hash > nh_upper_bound)
continue;
if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
break;
match = sibling;
break;
}
out:
res->f6i = match;
res->nh = match->fib6_nh;
}
/*
* Route lookup. rcu_read_lock() should be held.
*/
static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh,
const struct in6_addr *saddr, int oif, int flags)
{
const struct net_device *dev;
if (nh->fib_nh_flags & RTNH_F_DEAD)
return false;
dev = nh->fib_nh_dev;
if (oif) {
if (dev->ifindex == oif)
return true;
} else {
if (ipv6_chk_addr(net, saddr, dev,
flags & RT6_LOOKUP_F_IFACE))
return true;
}
return false;
}
struct fib6_nh_dm_arg {
struct net *net;
const struct in6_addr *saddr;
int oif;
int flags;
struct fib6_nh *nh;
};
static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg)
{
struct fib6_nh_dm_arg *arg = _arg;
arg->nh = nh;
return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif,
arg->flags);
}
/* returns fib6_nh from nexthop or NULL */
static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh,
struct fib6_result *res,
const struct in6_addr *saddr,
int oif, int flags)
{
struct fib6_nh_dm_arg arg = {
.net = net,
.saddr = saddr,
.oif = oif,
.flags = flags,
};
if (nexthop_is_blackhole(nh))
return NULL;
if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg))
return arg.nh;
return NULL;
}
static void rt6_device_match(struct net *net, struct fib6_result *res,
const struct in6_addr *saddr, int oif, int flags)
{
struct fib6_info *f6i = res->f6i;
struct fib6_info *spf6i;
struct fib6_nh *nh;
if (!oif && ipv6_addr_any(saddr)) {
if (unlikely(f6i->nh)) {
nh = nexthop_fib6_nh(f6i->nh);
if (nexthop_is_blackhole(f6i->nh))
goto out_blackhole;
} else {
nh = f6i->fib6_nh;
}
if (!(nh->fib_nh_flags & RTNH_F_DEAD))
goto out;
}
for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
bool matched = false;
if (unlikely(spf6i->nh)) {
nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr,
oif, flags);
if (nh)
matched = true;
} else {
nh = spf6i->fib6_nh;
if (__rt6_device_match(net, nh, saddr, oif, flags))
matched = true;
}
if (matched) {
res->f6i = spf6i;
goto out;
}
}
if (oif && flags & RT6_LOOKUP_F_IFACE) {
res->f6i = net->ipv6.fib6_null_entry;
nh = res->f6i->fib6_nh;
goto out;
}
if (unlikely(f6i->nh)) {
nh = nexthop_fib6_nh(f6i->nh);
if (nexthop_is_blackhole(f6i->nh))
goto out_blackhole;
} else {
nh = f6i->fib6_nh;
}
if (nh->fib_nh_flags & RTNH_F_DEAD) {
res->f6i = net->ipv6.fib6_null_entry;
nh = res->f6i->fib6_nh;
}
out:
res->nh = nh;
res->fib6_type = res->f6i->fib6_type;
res->fib6_flags = res->f6i->fib6_flags;
return;
out_blackhole:
res->fib6_flags |= RTF_REJECT;
res->fib6_type = RTN_BLACKHOLE;
res->nh = nh;
}
#ifdef CONFIG_IPV6_ROUTER_PREF
struct __rt6_probe_work {
struct work_struct work;
struct in6_addr target;
struct net_device *dev;
netdevice_tracker dev_tracker;
};
static void rt6_probe_deferred(struct work_struct *w)
{
struct in6_addr mcaddr;
struct __rt6_probe_work *work =
container_of(w, struct __rt6_probe_work, work);
addrconf_addr_solict_mult(&work->target, &mcaddr);
ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
netdev_put(work->dev, &work->dev_tracker);
kfree(work);
}
static void rt6_probe(struct fib6_nh *fib6_nh)
{
struct __rt6_probe_work *work = NULL;
const struct in6_addr *nh_gw;
unsigned long last_probe;
struct neighbour *neigh;
struct net_device *dev;
struct inet6_dev *idev;
/*
* Okay, this does not seem to be appropriate
* for now, however, we need to check if it
* is really so; aka Router Reachability Probing.
*
* Router Reachability Probe MUST be rate-limited
* to no more than one per minute.
*/
if (!fib6_nh->fib_nh_gw_family)
return;
nh_gw = &fib6_nh->fib_nh_gw6;
dev = fib6_nh->fib_nh_dev;
rcu_read_lock();
last_probe = READ_ONCE(fib6_nh->last_probe);
idev = __in6_dev_get(dev);
if (!idev)
goto out;
neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
if (neigh) {
if (READ_ONCE(neigh->nud_state) & NUD_VALID)
goto out;
write_lock_bh(&neigh->lock);
if (!(neigh->nud_state & NUD_VALID) &&
time_after(jiffies,
neigh->updated +
READ_ONCE(idev->cnf.rtr_probe_interval))) {
work = kmalloc(sizeof(*work), GFP_ATOMIC);
if (work)
__neigh_set_probe_once(neigh);
}
write_unlock_bh(&neigh->lock);
} else if (time_after(jiffies, last_probe +
READ_ONCE(idev->cnf.rtr_probe_interval))) {
work = kmalloc(sizeof(*work), GFP_ATOMIC);
}
if (!work || cmpxchg(&fib6_nh->last_probe,
last_probe, jiffies) != last_probe) {
kfree(work);
} else {
INIT_WORK(&work->work, rt6_probe_deferred);
work->target = *nh_gw;
netdev_hold(dev, &work->dev_tracker, GFP_ATOMIC);
work->dev = dev;
schedule_work(&work->work);
}
out:
rcu_read_unlock();
}
#else
static inline void rt6_probe(struct fib6_nh *fib6_nh)
{
}
#endif
/*
* Default Router Selection (RFC 2461 6.3.6)
*/
static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh)
{
enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
struct neighbour *neigh;
rcu_read_lock();
neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev,
&fib6_nh->fib_nh_gw6);
if (neigh) {
u8 nud_state = READ_ONCE(neigh->nud_state);
if (nud_state & NUD_VALID)
ret = RT6_NUD_SUCCEED;
#ifdef CONFIG_IPV6_ROUTER_PREF
else if (!(nud_state & NUD_FAILED))
ret = RT6_NUD_SUCCEED;
else
ret = RT6_NUD_FAIL_PROBE;
#endif
} else {
ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
}
rcu_read_unlock();
return ret;
}
static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
int strict)
{
int m = 0;
if (!oif || nh->fib_nh_dev->ifindex == oif)
m = 2;
if (!m && (strict & RT6_LOOKUP_F_IFACE))
return RT6_NUD_FAIL_HARD;
#ifdef CONFIG_IPV6_ROUTER_PREF
m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2;
#endif
if ((strict & RT6_LOOKUP_F_REACHABLE) &&
!(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) {
int n = rt6_check_neigh(nh);
if (n < 0)
return n;
}
return m;
}
static bool find_match(struct fib6_nh *nh, u32 fib6_flags,
int oif, int strict, int *mpri, bool *do_rr)
{
bool match_do_rr = false;
bool rc = false;
int m;
if (nh->fib_nh_flags & RTNH_F_DEAD)
goto out;
if (ip6_ignore_linkdown(nh->fib_nh_dev) &&
nh->fib_nh_flags & RTNH_F_LINKDOWN &&
!(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
goto out;
m = rt6_score_route(nh, fib6_flags, oif, strict);
if (m == RT6_NUD_FAIL_DO_RR) {
match_do_rr = true;
m = 0; /* lowest valid score */
} else if (m == RT6_NUD_FAIL_HARD) {
goto out;
}
if (strict & RT6_LOOKUP_F_REACHABLE)
rt6_probe(nh);
/* note that m can be RT6_NUD_FAIL_PROBE at this point */
if (m > *mpri) {
*do_rr = match_do_rr;
*mpri = m;
rc = true;
}
out:
return rc;
}
struct fib6_nh_frl_arg {
u32 flags;
int oif;
int strict;
int *mpri;
bool *do_rr;
struct fib6_nh *nh;
};
static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg)
{
struct fib6_nh_frl_arg *arg = _arg;
arg->nh = nh;
return find_match(nh, arg->flags, arg->oif, arg->strict,
arg->mpri, arg->do_rr);
}
static void __find_rr_leaf(struct fib6_info *f6i_start,
struct fib6_info *nomatch, u32 metric,
struct fib6_result *res, struct fib6_info **cont,
int oif, int strict, bool *do_rr, int *mpri)
{
struct fib6_info *f6i;
for (f6i = f6i_start;
f6i && f6i != nomatch;
f6i = rcu_dereference(f6i->fib6_next)) {
bool matched = false;
struct fib6_nh *nh;
if (cont && f6i->fib6_metric != metric) {
*cont = f6i;
return;
}
if (fib6_check_expired(f6i))
continue;
if (unlikely(f6i->nh)) {
struct fib6_nh_frl_arg arg = {
.flags = f6i->fib6_flags,
.oif = oif,
.strict = strict,
.mpri = mpri,
.do_rr = do_rr
};
if (nexthop_is_blackhole(f6i->nh)) {
res->fib6_flags = RTF_REJECT;
res->fib6_type = RTN_BLACKHOLE;
res->f6i = f6i;
res->nh = nexthop_fib6_nh(f6i->nh);
return;
}
if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match,
&arg)) {
matched = true;
nh = arg.nh;
}
} else {
nh = f6i->fib6_nh;
if (find_match(nh, f6i->fib6_flags, oif, strict,
mpri, do_rr))
matched = true;
}
if (matched) {
res->f6i = f6i;
res->nh = nh;
res->fib6_flags = f6i->fib6_flags;
res->fib6_type = f6i->fib6_type;
}
}
}
static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf,
struct fib6_info *rr_head, int oif, int strict,
bool *do_rr, struct fib6_result *res)
{
u32 metric = rr_head->fib6_metric;
struct fib6_info *cont = NULL;
int mpri = -1;
__find_rr_leaf(rr_head, NULL, metric, res, &cont,
oif, strict, do_rr, &mpri);
__find_rr_leaf(leaf, rr_head, metric, res, &cont,
oif, strict, do_rr, &mpri);
if (res->f6i || !cont)
return;
__find_rr_leaf(cont, NULL, metric, res, NULL,
oif, strict, do_rr, &mpri);
}
static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
struct fib6_result *res, int strict)
{
struct fib6_info *leaf = rcu_dereference(fn->leaf);
struct fib6_info *rt0;
bool do_rr = false;
int key_plen;
/* make sure this function or its helpers sets f6i */
res->f6i = NULL;
if (!leaf || leaf == net->ipv6.fib6_null_entry)
goto out;
rt0 = rcu_dereference(fn->rr_ptr);
if (!rt0)
rt0 = leaf;
/* Double check to make sure fn is not an intermediate node
* and fn->leaf does not points to its child's leaf
* (This might happen if all routes under fn are deleted from
* the tree and fib6_repair_tree() is called on the node.)
*/
key_plen = rt0->fib6_dst.plen;
#ifdef CONFIG_IPV6_SUBTREES
if (rt0->fib6_src.plen)
key_plen = rt0->fib6_src.plen;
#endif
if (fn->fn_bit != key_plen)
goto out;
find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res);
if (do_rr) {
struct fib6_info *next = rcu_dereference(rt0->fib6_next);
/* no entries matched; do round-robin */
if (!next || next->fib6_metric != rt0->fib6_metric)
next = leaf;
if (next != rt0) {
spin_lock_bh(&leaf->fib6_table->tb6_lock);
/* make sure next is not being deleted from the tree */
if (next->fib6_node)
rcu_assign_pointer(fn->rr_ptr, next);
spin_unlock_bh(&leaf->fib6_table->tb6_lock);
}
}
out:
if (!res->f6i) {
res->f6i = net->ipv6.fib6_null_entry;
res->nh = res->f6i->fib6_nh;
res->fib6_flags = res->f6i->fib6_flags;
res->fib6_type = res->f6i->fib6_type;
}
}
static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res)
{
return (res->f6i->fib6_flags & RTF_NONEXTHOP) ||
res->nh->fib_nh_gw_family;
}
#ifdef CONFIG_IPV6_ROUTE_INFO
int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
const struct in6_addr *gwaddr)
{
struct net *net = dev_net(dev);
struct route_info *rinfo = (struct route_info *) opt;
struct in6_addr prefix_buf, *prefix;
struct fib6_table *table;
unsigned int pref;
unsigned long lifetime;
struct fib6_info *rt;
if (len < sizeof(struct route_info)) {
return -EINVAL;
}
/* Sanity check for prefix_len and length */
if (rinfo->length > 3) {
return -EINVAL;
} else if (rinfo->prefix_len > 128) {
return -EINVAL;
} else if (rinfo->prefix_len > 64) {
if (rinfo->length < 2) {
return -EINVAL;
}
} else if (rinfo->prefix_len > 0) {
if (rinfo->length < 1) {
return -EINVAL;
}
}
pref = rinfo->route_pref;
if (pref == ICMPV6_ROUTER_PREF_INVALID)
return -EINVAL;
lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
if (rinfo->length == 3)
prefix = (struct in6_addr *)rinfo->prefix;
else {
/* this function is safe */
ipv6_addr_prefix(&prefix_buf,
(struct in6_addr *)rinfo->prefix,
rinfo->prefix_len);
prefix = &prefix_buf;
}
if (rinfo->prefix_len == 0)
rt = rt6_get_dflt_router(net, gwaddr, dev);
else
rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
gwaddr, dev);
if (rt && !lifetime) {
ip6_del_rt(net, rt, false);
rt = NULL;
}
if (!rt && lifetime)
rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
dev, pref);
else if (rt)
rt->fib6_flags = RTF_ROUTEINFO |
(rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
if (rt) {
table = rt->fib6_table;
spin_lock_bh(&table->tb6_lock);
if (!addrconf_finite_timeout(lifetime)) {
fib6_clean_expires(rt);
fib6_remove_gc_list(rt);
} else {
fib6_set_expires(rt, jiffies + HZ * lifetime);
fib6_add_gc_list(rt);
}
spin_unlock_bh(&table->tb6_lock);
fib6_info_release(rt);
}
return 0;
}
#endif
/*
* Misc support functions
*/
/* called with rcu_lock held */
static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
{
struct net_device *dev = res->nh->fib_nh_dev;
if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
/* for copies of local routes, dst->dev needs to be the
* device if it is a master device, the master device if
* device is enslaved, and the loopback as the default
*/
if (netif_is_l3_slave(dev) &&
!rt6_need_strict(&res->f6i->fib6_dst.addr))
dev = l3mdev_master_dev_rcu(dev);
else if (!netif_is_l3_master(dev))
dev = dev_net(dev)->loopback_dev;
/* last case is netif_is_l3_master(dev) is true in which
* case we want dev returned to be dev
*/
}
return dev;
}
static const int fib6_prop[RTN_MAX + 1] = {
[RTN_UNSPEC] = 0,
[RTN_UNICAST] = 0,
[RTN_LOCAL] = 0,
[RTN_BROADCAST] = 0,
[RTN_ANYCAST] = 0,
[RTN_MULTICAST] = 0,
[RTN_BLACKHOLE] = -EINVAL,
[RTN_UNREACHABLE] = -EHOSTUNREACH,
[RTN_PROHIBIT] = -EACCES,
[RTN_THROW] = -EAGAIN,
[RTN_NAT] = -EINVAL,
[RTN_XRESOLVE] = -EINVAL,
};
static int ip6_rt_type_to_error(u8 fib6_type)
{
return fib6_prop[fib6_type];
}
static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
{
unsigned short flags = 0;
if (rt->dst_nocount)
flags |= DST_NOCOUNT;
if (rt->dst_nopolicy)
flags |= DST_NOPOLICY;
return flags;
}
static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
{
rt->dst.error = ip6_rt_type_to_error(fib6_type);
switch (fib6_type) {
case RTN_BLACKHOLE:
rt->dst.output = dst_discard_out;
rt->dst.input = dst_discard;
break;
case RTN_PROHIBIT:
rt->dst.output = ip6_pkt_prohibit_out;
rt->dst.input = ip6_pkt_prohibit;
break;
case RTN_THROW:
case RTN_UNREACHABLE:
default:
rt->dst.output = ip6_pkt_discard_out;
rt->dst.input = ip6_pkt_discard;
break;
}
}
static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
{
struct fib6_info *f6i = res->f6i;
if (res->fib6_flags & RTF_REJECT) {
ip6_rt_init_dst_reject(rt, res->fib6_type);
return;
}
rt->dst.error = 0;
rt->dst.output = ip6_output;
if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
rt->dst.input = ip6_input;
} else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
rt->dst.input = ip6_mc_input;
} else {
rt->dst.input = ip6_forward;
}
if (res->nh->fib_nh_lws) {
rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws);
lwtunnel_set_redirect(&rt->dst);
}
rt->dst.lastuse = jiffies;
}
/* Caller must already hold reference to @from */
static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
{
rt->rt6i_flags &= ~RTF_EXPIRES;
rcu_assign_pointer(rt->from, from);
ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
}
/* Caller must already hold reference to f6i in result */
static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
{
const struct fib6_nh *nh = res->nh;
const struct net_device *dev = nh->fib_nh_dev;
struct fib6_info *f6i = res->f6i;
ip6_rt_init_dst(rt, res);
rt->rt6i_dst = f6i->fib6_dst;
rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
rt->rt6i_flags = res->fib6_flags;
if (nh->fib_nh_gw_family) {
rt->rt6i_gateway = nh->fib_nh_gw6;
rt->rt6i_flags |= RTF_GATEWAY;
}
rt6_set_from(rt, f6i);
#ifdef CONFIG_IPV6_SUBTREES
rt->rt6i_src = f6i->fib6_src;
#endif
}
static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
struct in6_addr *saddr)
{
struct fib6_node *pn, *sn;
while (1) {
if (fn->fn_flags & RTN_TL_ROOT)
return NULL;
pn = rcu_dereference(fn->parent);
sn = FIB6_SUBTREE(pn);
if (sn && sn != fn)
fn = fib6_node_lookup(sn, NULL, saddr);
else
fn = pn;
if (fn->fn_flags & RTN_RTINFO)
return fn;
}
}
static bool ip6_hold_safe(struct net *net, struct rt6_info **prt)
{
struct rt6_info *rt = *prt;
if (dst_hold_safe(&rt->dst))
return true;
if (net) {
rt = net->ipv6.ip6_null_entry;
dst_hold(&rt->dst);
} else {
rt = NULL;
}
*prt = rt;
return false;
}
/* called with rcu_lock held */
static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res)
{
struct net_device *dev = res->nh->fib_nh_dev;
struct fib6_info *f6i = res->f6i;
unsigned short flags;
struct rt6_info *nrt;
if (!fib6_info_hold_safe(f6i))
goto fallback;
flags = fib6_info_dst_flags(f6i);
nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
if (!nrt) {
fib6_info_release(f6i);
goto fallback;
}
ip6_rt_copy_init(nrt, res);
return nrt;
fallback:
nrt = dev_net(dev)->ipv6.ip6_null_entry;
dst_hold(&nrt->dst);
return nrt;
}
INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net,
struct fib6_table *table,
struct flowi6 *fl6,
const struct sk_buff *skb,
int flags)
{
struct fib6_result res = {};
struct fib6_node *fn;
struct rt6_info *rt;
rcu_read_lock();
fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
restart:
res.f6i = rcu_dereference(fn->leaf);
if (!res.f6i)
res.f6i = net->ipv6.fib6_null_entry;
else
rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif,
flags);
if (res.f6i == net->ipv6.fib6_null_entry) {
fn = fib6_backtrack(fn, &fl6->saddr);
if (fn)
goto restart;
rt = net->ipv6.ip6_null_entry;
dst_hold(&rt->dst);
goto out;
} else if (res.fib6_flags & RTF_REJECT) {
goto do_create;
}
fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
fl6->flowi6_oif != 0, skb, flags);
/* Search through exception table */
rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
if (rt) {
if (ip6_hold_safe(net, &rt))
dst_use_noref(&rt->dst, jiffies);
} else {
do_create:
rt = ip6_create_rt_rcu(&res);
}
out:
trace_fib6_table_lookup(net, &res, table, fl6);
rcu_read_unlock();
return rt;
}
struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
const struct sk_buff *skb, int flags)
{
return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
}
EXPORT_SYMBOL_GPL(ip6_route_lookup);
struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
const struct in6_addr *saddr, int oif,
const struct sk_buff *skb, int strict)
{
struct flowi6 fl6 = {
.flowi6_oif = oif,
.daddr = *daddr,
};
struct dst_entry *dst;
int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
if (saddr) {
memcpy(&fl6.saddr, saddr, sizeof(*saddr));
flags |= RT6_LOOKUP_F_HAS_SADDR;
}
dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
if (dst->error == 0)
return dst_rt6_info(dst);
dst_release(dst);
return NULL;
}
EXPORT_SYMBOL(rt6_lookup);
/* ip6_ins_rt is called with FREE table->tb6_lock.
* It takes new route entry, the addition fails by any reason the
* route is released.
* Caller must hold dst before calling it.
*/
static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
struct netlink_ext_ack *extack)
{
int err;
struct fib6_table *table;
table = rt->fib6_table;
spin_lock_bh(&table->tb6_lock);
err = fib6_add(&table->tb6_root, rt, info, extack);
spin_unlock_bh(&table->tb6_lock);
return err;
}
int ip6_ins_rt(struct net *net, struct fib6_info *rt)
{
struct nl_info info = { .nl_net = net, };
return __ip6_ins_rt(rt, &info, NULL);
}
static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res,
const struct in6_addr *daddr,
const struct in6_addr *saddr)
{
struct fib6_info *f6i = res->f6i;
struct net_device *dev;
struct rt6_info *rt;
/*
* Clone the route.
*/
if (!fib6_info_hold_safe(f6i))
return NULL;
dev = ip6_rt_get_dev_rcu(res);
rt = ip6_dst_alloc(dev_net(dev), dev, 0);
if (!rt) {
fib6_info_release(f6i);
return NULL;
}
ip6_rt_copy_init(rt, res);
rt->rt6i_flags |= RTF_CACHE;
rt->rt6i_dst.addr = *daddr;
rt->rt6i_dst.plen = 128;
if (!rt6_is_gw_or_nonexthop(res)) {
if (f6i->fib6_dst.plen != 128 &&
ipv6_addr_equal(&f6i->fib6_dst.addr, daddr))
rt->rt6i_flags |= RTF_ANYCAST;
#ifdef CONFIG_IPV6_SUBTREES
if (rt->rt6i_src.plen && saddr) {
rt->rt6i_src.addr = *saddr;
rt->rt6i_src.plen = 128;
}
#endif
}
return rt;
}
static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res)
{
struct fib6_info *f6i = res->f6i;
unsigned short flags = fib6_info_dst_flags(f6i);
struct net_device *dev;
struct rt6_info *pcpu_rt;
if (!fib6_info_hold_safe(f6i))
return NULL;
rcu_read_lock();
dev = ip6_rt_get_dev_rcu(res);
pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT);
rcu_read_unlock();
if (!pcpu_rt) {
fib6_info_release(f6i);
return NULL;
}
ip6_rt_copy_init(pcpu_rt, res);
pcpu_rt->rt6i_flags |= RTF_PCPU;
if (f6i->nh)
pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev));
return pcpu_rt;
}
static bool rt6_is_valid(const struct rt6_info *rt6)
{
return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev));
}
/* It should be called with rcu_read_lock() acquired */
static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
{
struct rt6_info *pcpu_rt;
pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) {
struct rt6_info *prev, **p;
p = this_cpu_ptr(res->nh->rt6i_pcpu);
/* Paired with READ_ONCE() in __fib6_drop_pcpu_from() */
prev = xchg(p, NULL);
if (prev) {
dst_dev_put(&prev->dst);
dst_release(&prev->dst);
}
pcpu_rt = NULL;
}
return pcpu_rt;
}
static struct rt6_info *rt6_make_pcpu_route(struct net *net,
const struct fib6_result *res)
{
struct rt6_info *pcpu_rt, *prev, **p;
pcpu_rt = ip6_rt_pcpu_alloc(res);
if (!pcpu_rt)
return NULL;
p = this_cpu_ptr(res->nh->rt6i_pcpu);
prev = cmpxchg(p, NULL, pcpu_rt);
BUG_ON(prev);
if (res->f6i->fib6_destroying) {
struct fib6_info *from;
from = unrcu_pointer(xchg(&pcpu_rt->from, NULL));
fib6_info_release(from);
}
return pcpu_rt;
}
/* exception hash table implementation
*/
static DEFINE_SPINLOCK(rt6_exception_lock);
/* Remove rt6_ex from hash table and free the memory
* Caller must hold rt6_exception_lock
*/
static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
struct rt6_exception *rt6_ex)
{
struct fib6_info *from;
struct net *net;
if (!bucket || !rt6_ex)
return;
net = dev_net(rt6_ex->rt6i->dst.dev);
net->ipv6.rt6_stats->fib_rt_cache--;
/* purge completely the exception to allow releasing the held resources:
* some [sk] cache may keep the dst around for unlimited time
*/
from = unrcu_pointer(xchg(&rt6_ex->rt6i->from, NULL));
fib6_info_release(from);
dst_dev_put(&rt6_ex->rt6i->dst);
hlist_del_rcu(&rt6_ex->hlist);
dst_release(&rt6_ex->rt6i->dst);
kfree_rcu(rt6_ex, rcu);
WARN_ON_ONCE(!bucket->depth);
bucket->depth--;
}
/* Remove oldest rt6_ex in bucket and free the memory
* Caller must hold rt6_exception_lock
*/
static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
{
struct rt6_exception *rt6_ex, *oldest = NULL;
if (!bucket)
return;
hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
oldest = rt6_ex;
}
rt6_remove_exception(bucket, oldest);
}
static u32 rt6_exception_hash(const struct in6_addr *dst,
const struct in6_addr *src)
{
static siphash_aligned_key_t rt6_exception_key;
struct {
struct in6_addr dst;
struct in6_addr src;
} __aligned(SIPHASH_ALIGNMENT) combined = {
.dst = *dst,
};
u64 val;
net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key));
#ifdef CONFIG_IPV6_SUBTREES
if (src)
combined.src = *src;
#endif
val = siphash(&combined, sizeof(combined), &rt6_exception_key);
return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
}
/* Helper function to find the cached rt in the hash table
* and update bucket pointer to point to the bucket for this
* (daddr, saddr) pair
* Caller must hold rt6_exception_lock
*/
static struct rt6_exception *
__rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
const struct in6_addr *daddr,
const struct in6_addr *saddr)
{
struct rt6_exception *rt6_ex;
u32 hval;
if (!(*bucket) || !daddr)
return NULL;
hval = rt6_exception_hash(daddr, saddr);
*bucket += hval;
hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
struct rt6_info *rt6 = rt6_ex->rt6i;
bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
#ifdef CONFIG_IPV6_SUBTREES
if (matched && saddr)
matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
#endif
if (matched)
return rt6_ex;
}
return NULL;
}
/* Helper function to find the cached rt in the hash table
* and update bucket pointer to point to the bucket for this
* (daddr, saddr) pair
* Caller must hold rcu_read_lock()
*/
static struct rt6_exception *
__rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
const struct in6_addr *daddr,
const struct in6_addr *saddr)
{
struct rt6_exception *rt6_ex;
u32 hval;
WARN_ON_ONCE(!rcu_read_lock_held());
if (!(*bucket) || !daddr)
return NULL;
hval = rt6_exception_hash(daddr, saddr);
*bucket += hval;
hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
struct rt6_info *rt6 = rt6_ex->rt6i;
bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
#ifdef CONFIG_IPV6_SUBTREES
if (matched && saddr)
matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
#endif
if (matched)
return rt6_ex;
}
return NULL;
}
static unsigned int fib6_mtu(const struct fib6_result *res)
{
const struct fib6_nh *nh = res->nh;
unsigned int mtu;
if (res->f6i->fib6_pmtu) {
mtu = res->f6i->fib6_pmtu;
} else {
struct net_device *dev = nh->fib_nh_dev;
struct inet6_dev *idev;
rcu_read_lock();
idev = __in6_dev_get(dev);
mtu = READ_ONCE(idev->cnf.mtu6);
rcu_read_unlock();
}
mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
}
#define FIB6_EXCEPTION_BUCKET_FLUSHED 0x1UL
/* used when the flushed bit is not relevant, only access to the bucket
* (ie., all bucket users except rt6_insert_exception);
*
* called under rcu lock; sometimes called with rt6_exception_lock held
*/
static
struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh,
spinlock_t *lock)
{
struct rt6_exception_bucket *bucket;
if (lock)
bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
lockdep_is_held(lock));
else
bucket = rcu_dereference(nh->rt6i_exception_bucket);
/* remove bucket flushed bit if set */
if (bucket) {
unsigned long p = (unsigned long)bucket;
p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED;
bucket = (struct rt6_exception_bucket *)p;
}
return bucket;
}
static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket)
{
unsigned long p = (unsigned long)bucket;
return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED);
}
/* called with rt6_exception_lock held */
static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh,
spinlock_t *lock)
{
struct rt6_exception_bucket *bucket;
unsigned long p;
bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
lockdep_is_held(lock));
p = (unsigned long)bucket;
p |= FIB6_EXCEPTION_BUCKET_FLUSHED;
bucket = (struct rt6_exception_bucket *)p;
rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
}
static int rt6_insert_exception(struct rt6_info *nrt,
const struct fib6_result *res)
{
struct net *net = dev_net(nrt->dst.dev);
struct rt6_exception_bucket *bucket;
struct fib6_info *f6i = res->f6i;
struct in6_addr *src_key = NULL;
struct rt6_exception *rt6_ex;
struct fib6_nh *nh = res->nh;
int max_depth;
int err = 0;
spin_lock_bh(&rt6_exception_lock);
bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
lockdep_is_held(&rt6_exception_lock));
if (!bucket) {
bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
GFP_ATOMIC);
if (!bucket) {
err = -ENOMEM;
goto out;
}
rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
} else if (fib6_nh_excptn_bucket_flushed(bucket)) {
err = -EINVAL;
goto out;
}
#ifdef CONFIG_IPV6_SUBTREES
/* fib6_src.plen != 0 indicates f6i is in subtree
* and exception table is indexed by a hash of
* both fib6_dst and fib6_src.
* Otherwise, the exception table is indexed by
* a hash of only fib6_dst.
*/
if (f6i->fib6_src.plen)
src_key = &nrt->rt6i_src.addr;
#endif
/* rt6_mtu_change() might lower mtu on f6i.
* Only insert this exception route if its mtu
* is less than f6i's mtu value.
*/
if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) {
err = -EINVAL;
goto out;
}
rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
src_key);
if (rt6_ex)
rt6_remove_exception(bucket, rt6_ex);
rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
if (!rt6_ex) {
err = -ENOMEM;
goto out;
}
rt6_ex->rt6i = nrt;
rt6_ex->stamp = jiffies;
hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
bucket->depth++;
net->ipv6.rt6_stats->fib_rt_cache++;
/* Randomize max depth to avoid some side channels attacks. */
max_depth = FIB6_MAX_DEPTH + get_random_u32_below(FIB6_MAX_DEPTH);
while (bucket->depth > max_depth)
rt6_exception_remove_oldest(bucket);
out:
spin_unlock_bh(&rt6_exception_lock);
/* Update fn->fn_sernum to invalidate all cached dst */
if (!err) {
spin_lock_bh(&f6i->fib6_table->tb6_lock);
fib6_update_sernum(net, f6i);
spin_unlock_bh(&f6i->fib6_table->tb6_lock);
fib6_force_start_gc(net);
}
return err;
}
static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
{
struct rt6_exception_bucket *bucket;
struct rt6_exception *rt6_ex;
struct hlist_node *tmp;
int i;
spin_lock_bh(&rt6_exception_lock);
bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
if (!bucket)
goto out;
/* Prevent rt6_insert_exception() to recreate the bucket list */
if (!from)
fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock);
for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) {
if (!from ||
rcu_access_pointer(rt6_ex->rt6i->from) == from)
rt6_remove_exception(bucket, rt6_ex);
}
WARN_ON_ONCE(!from && bucket->depth);
bucket++;
}
out:
spin_unlock_bh(&rt6_exception_lock);
}
static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg)
{
struct fib6_info *f6i = arg;
fib6_nh_flush_exceptions(nh, f6i);
return 0;
}
void rt6_flush_exceptions(struct fib6_info *f6i)
{
if (f6i->nh)
nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions,
f6i);
else
fib6_nh_flush_exceptions(f6i->fib6_nh, f6i);
}
/* Find cached rt in the hash table inside passed in rt
* Caller has to hold rcu_read_lock()
*/
static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
const struct in6_addr *daddr,
const struct in6_addr *saddr)
{
const struct in6_addr *src_key = NULL;
struct rt6_exception_bucket *bucket;
struct rt6_exception *rt6_ex;
struct rt6_info *ret = NULL;
#ifdef CONFIG_IPV6_SUBTREES
/* fib6i_src.plen != 0 indicates f6i is in subtree
* and exception table is indexed by a hash of
* both fib6_dst and fib6_src.
* However, the src addr used to create the hash
* might not be exactly the passed in saddr which
* is a /128 addr from the flow.
* So we need to use f6i->fib6_src to redo lookup
* if the passed in saddr does not find anything.
* (See the logic in ip6_rt_cache_alloc() on how
* rt->rt6i_src is updated.)
*/
if (res->f6i->fib6_src.plen)
src_key = saddr;
find_ex:
#endif
bucket = fib6_nh_get_excptn_bucket(res->nh, NULL);
rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
ret = rt6_ex->rt6i;
#ifdef CONFIG_IPV6_SUBTREES
/* Use fib6_src as src_key and redo lookup */
if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) {
src_key = &res->f6i->fib6_src.addr;
goto find_ex;
}
#endif
return ret;
}
/* Remove the passed in cached rt from the hash table that contains it */
static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen,
const struct rt6_info *rt)
{
const struct in6_addr *src_key = NULL;
struct rt6_exception_bucket *bucket;
struct rt6_exception *rt6_ex;
int err;
if (!rcu_access_pointer(nh->rt6i_exception_bucket))
return -ENOENT;
spin_lock_bh(&rt6_exception_lock);
bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
#ifdef CONFIG_IPV6_SUBTREES
/* rt6i_src.plen != 0 indicates 'from' is in subtree
* and exception table is indexed by a hash of
* both rt6i_dst and rt6i_src.
* Otherwise, the exception table is indexed by
* a hash of only rt6i_dst.
*/
if (plen)
src_key = &rt->rt6i_src.addr;
#endif
rt6_ex = __rt6_find_exception_spinlock(&bucket,
&rt->rt6i_dst.addr,
src_key);
if (rt6_ex) {
rt6_remove_exception(bucket, rt6_ex);
err = 0;
} else {
err = -ENOENT;
}
spin_unlock_bh(&rt6_exception_lock);
return err;
}
struct fib6_nh_excptn_arg {
struct rt6_info *rt;
int plen;
};
static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg)
{
struct fib6_nh_excptn_arg *arg = _arg;
int err;
err = fib6_nh_remove_exception(nh, arg->plen, arg->rt);
if (err == 0)
return 1;
return 0;
}
static int rt6_remove_exception_rt(struct rt6_info *rt)
{
struct fib6_info *from;
from = rcu_dereference(rt->from);
if (!from || !(rt->rt6i_flags & RTF_CACHE))
return -EINVAL;
if (from->nh) {
struct fib6_nh_excptn_arg arg = {
.rt = rt,
.plen = from->fib6_src.plen
};
int rc;
/* rc = 1 means an entry was found */
rc = nexthop_for_each_fib6_nh(from->nh,
rt6_nh_remove_exception_rt,
&arg);
return rc ? 0 : -ENOENT;
}
return fib6_nh_remove_exception(from->fib6_nh,
from->fib6_src.plen, rt);
}
/* Find rt6_ex which contains the passed in rt cache and
* refresh its stamp
*/
static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen,
const struct rt6_info *rt)
{
const struct in6_addr *src_key = NULL;
struct rt6_exception_bucket *bucket;
struct rt6_exception *rt6_ex;
bucket = fib6_nh_get_excptn_bucket(nh, NULL);
#ifdef CONFIG_IPV6_SUBTREES
/* rt6i_src.plen != 0 indicates 'from' is in subtree
* and exception table is indexed by a hash of
* both rt6i_dst and rt6i_src.
* Otherwise, the exception table is indexed by
* a hash of only rt6i_dst.
*/
if (plen)
src_key = &rt->rt6i_src.addr;
#endif
rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
if (rt6_ex)
rt6_ex->stamp = jiffies;
}
struct fib6_nh_match_arg {
const struct net_device *dev;
const struct in6_addr *gw;
struct fib6_nh *match;
};
/* determine if fib6_nh has given device and gateway */
static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg)
{
struct fib6_nh_match_arg *arg = _arg;
if (arg->dev != nh->fib_nh_dev ||
(arg->gw && !nh->fib_nh_gw_family) ||
(!arg->gw && nh->fib_nh_gw_family) ||
(arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6)))
return 0;
arg->match = nh;
/* found a match, break the loop */
return 1;
}
static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
{
struct fib6_info *from;
struct fib6_nh *fib6_nh;
rcu_read_lock();
from = rcu_dereference(rt->from);
if (!from || !(rt->rt6i_flags & RTF_CACHE))
goto unlock;
if (from->nh) {
struct fib6_nh_match_arg arg = {
.dev = rt->dst.dev,
.gw = &rt->rt6i_gateway,
};
nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
if (!arg.match)
goto unlock;
fib6_nh = arg.match;
} else {
fib6_nh = from->fib6_nh;
}
fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt);
unlock:
rcu_read_unlock();
}
static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
struct rt6_info *rt, int mtu)
{
/* If the new MTU is lower than the route PMTU, this new MTU will be the
* lowest MTU in the path: always allow updating the route PMTU to
* reflect PMTU decreases.
*
* If the new MTU is higher, and the route PMTU is equal to the local
* MTU, this means the old MTU is the lowest in the path, so allow
* updating it: if other nodes now have lower MTUs, PMTU discovery will
* handle this.
*/
if (dst_mtu(&rt->dst) >= mtu)
return true;
if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
return true;
return false;
}
static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
const struct fib6_nh *nh, int mtu)
{
struct rt6_exception_bucket *bucket;
struct rt6_exception *rt6_ex;
int i;
bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
if (!bucket)
return;
for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
struct rt6_info *entry = rt6_ex->rt6i;
/* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
* route), the metrics of its rt->from have already
* been updated.
*/
if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
rt6_mtu_change_route_allowed(idev, entry, mtu))
dst_metric_set(&entry->dst, RTAX_MTU, mtu);
}
bucket++;
}
}
#define RTF_CACHE_GATEWAY (RTF_GATEWAY | RTF_CACHE)
static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh,
const struct in6_addr *gateway)
{
struct rt6_exception_bucket *bucket;
struct rt6_exception *rt6_ex;
struct hlist_node *tmp;
int i;
if (!rcu_access_pointer(nh->rt6i_exception_bucket))
return;
spin_lock_bh(&rt6_exception_lock);
bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
if (bucket) {
for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
hlist_for_each_entry_safe(rt6_ex, tmp,
&bucket->chain, hlist) {
struct rt6_info *entry = rt6_ex->rt6i;
if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
RTF_CACHE_GATEWAY &&
ipv6_addr_equal(gateway,
&entry->rt6i_gateway)) {
rt6_remove_exception(bucket, rt6_ex);
}
}
bucket++;
}
}
spin_unlock_bh(&rt6_exception_lock);
}
static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
struct rt6_exception *rt6_ex,
struct fib6_gc_args *gc_args,
unsigned long now)
{
struct rt6_info *rt = rt6_ex->rt6i;
/* we are pruning and obsoleting aged-out and non gateway exceptions
* even if others have still references to them, so that on next
* dst_check() such references can be dropped.
* EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
* expired, independently from their aging, as per RFC 8201 section 4
*/
if (!(rt->rt6i_flags & RTF_EXPIRES)) {
if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
pr_debug("aging clone %p\n", rt);
rt6_remove_exception(bucket, rt6_ex);
return;
}
} else if (time_after(jiffies, rt->dst.expires)) {
pr_debug("purging expired route %p\n", rt);
rt6_remove_exception(bucket, rt6_ex);
return;
}
if (rt->rt6i_flags & RTF_GATEWAY) {
struct neighbour *neigh;
neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
if (!(neigh && (neigh->flags & NTF_ROUTER))) {
pr_debug("purging route %p via non-router but gateway\n",
rt);
rt6_remove_exception(bucket, rt6_ex);
return;
}
}
gc_args->more++;
}
static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
struct fib6_gc_args *gc_args,
unsigned long now)
{
struct rt6_exception_bucket *bucket;
struct rt6_exception *rt6_ex;
struct hlist_node *tmp;
int i;
if (!rcu_access_pointer(nh->rt6i_exception_bucket))
return;
rcu_read_lock_bh();
spin_lock(&rt6_exception_lock);
bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
if (bucket) {
for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
hlist_for_each_entry_safe(rt6_ex, tmp,
&bucket->chain, hlist) {
rt6_age_examine_exception(bucket, rt6_ex,
gc_args, now);
}
bucket++;
}
}
spin_unlock(&rt6_exception_lock);
rcu_read_unlock_bh();
}
struct fib6_nh_age_excptn_arg {
struct fib6_gc_args *gc_args;
unsigned long now;
};
static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg)
{
struct fib6_nh_age_excptn_arg *arg = _arg;
fib6_nh_age_exceptions(nh, arg->gc_args, arg->now);
return 0;
}
void rt6_age_exceptions(struct fib6_info *f6i,
struct fib6_gc_args *gc_args,
unsigned long now)
{
if (f6i->nh) {
struct fib6_nh_age_excptn_arg arg = {
.gc_args = gc_args,
.now = now
};
nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions,
&arg);
} else {
fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now);
}
}
/* must be called with rcu lock held */
int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
struct flowi6 *fl6, struct fib6_result *res, int strict)
{
struct fib6_node *fn, *saved_fn;
fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
saved_fn = fn;
redo_rt6_select:
rt6_select(net, fn, oif, res, strict);
if (res->f6i == net->ipv6.fib6_null_entry) {
fn = fib6_backtrack(fn, &fl6->saddr);
if (fn)
goto redo_rt6_select;
else if (strict & RT6_LOOKUP_F_REACHABLE) {
/* also consider unreachable route */
strict &= ~RT6_LOOKUP_F_REACHABLE;
fn = saved_fn;
goto redo_rt6_select;
}
}
trace_fib6_table_lookup(net, res, table, fl6);
return 0;
}
struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
int oif, struct flowi6 *fl6,
const struct sk_buff *skb, int flags)
{
struct fib6_result res = {};
struct rt6_info *rt = NULL;
int strict = 0;
WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
!rcu_read_lock_held());
strict |= flags & RT6_LOOKUP_F_IFACE;
strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
if (READ_ONCE(net->ipv6.devconf_all->forwarding) == 0)
strict |= RT6_LOOKUP_F_REACHABLE;
rcu_read_lock();
fib6_table_lookup(net, table, oif, fl6, &res, strict);
if (res.f6i == net->ipv6.fib6_null_entry)
goto out;
fib6_select_path(net, &res, fl6, oif, false, skb, strict);
/*Search through exception table */
rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
if (rt) {
goto out;
} else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
!res.nh->fib_nh_gw_family)) {
/* Create a RTF_CACHE clone which will not be
* owned by the fib6 tree. It is for the special case where
* the daddr in the skb during the neighbor look-up is different
* from the fl6->daddr used to look-up route here.
*/
rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
if (rt) {
/* 1 refcnt is taken during ip6_rt_cache_alloc().
* As rt6_uncached_list_add() does not consume refcnt,
* this refcnt is always returned to the caller even
* if caller sets RT6_LOOKUP_F_DST_NOREF flag.
*/
rt6_uncached_list_add(rt);
rcu_read_unlock();
return rt;
}
} else {
/* Get a percpu copy */
local_bh_disable();
rt = rt6_get_pcpu_route(&res);
if (!rt)
rt = rt6_make_pcpu_route(net, &res);
local_bh_enable();
}
out:
if (!rt)
rt = net->ipv6.ip6_null_entry;
if (!(flags & RT6_LOOKUP_F_DST_NOREF))
ip6_hold_safe(net, &rt);
rcu_read_unlock();
return rt;
}
EXPORT_SYMBOL_GPL(ip6_pol_route);
INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net,
struct fib6_table *table,
struct flowi6 *fl6,
const struct sk_buff *skb,
int flags)
{
return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
}
struct dst_entry *ip6_route_input_lookup(struct net *net,
struct net_device *dev,
struct flowi6 *fl6,
const struct sk_buff *skb,
int flags)
{
if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
flags |= RT6_LOOKUP_F_IFACE;
return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
}
EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
static void ip6_multipath_l3_keys(const struct sk_buff *skb,
struct flow_keys *keys,
struct flow_keys *flkeys)
{
const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
const struct ipv6hdr *key_iph = outer_iph;
struct flow_keys *_flkeys = flkeys;
const struct ipv6hdr *inner_iph;
const struct icmp6hdr *icmph;
struct ipv6hdr _inner_iph;
struct icmp6hdr _icmph;
if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
goto out;
icmph = skb_header_pointer(skb, skb_transport_offset(skb),
sizeof(_icmph), &_icmph);
if (!icmph)
goto out;
if (!icmpv6_is_err(icmph->icmp6_type))
goto out;
inner_iph = skb_header_pointer(skb,
skb_transport_offset(skb) + sizeof(*icmph),
sizeof(_inner_iph), &_inner_iph);
if (!inner_iph)
goto out;
key_iph = inner_iph;
_flkeys = NULL;
out:
if (_flkeys) {
keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
keys->tags.flow_label = _flkeys->tags.flow_label;
keys->basic.ip_proto = _flkeys->basic.ip_proto;
} else {
keys->addrs.v6addrs.src = key_iph->saddr;
keys->addrs.v6addrs.dst = key_iph->daddr;
keys->tags.flow_label = ip6_flowlabel(key_iph);
keys->basic.ip_proto = key_iph->nexthdr;
}
}
static u32 rt6_multipath_custom_hash_outer(const struct net *net,
const struct sk_buff *skb,
bool *p_has_inner)
{
u32 hash_fields = ip6_multipath_hash_fields(net);
struct flow_keys keys, hash_keys;
if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
return 0;
memset(&hash_keys, 0, sizeof(hash_keys));
skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP);
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
hash_keys.basic.ip_proto = keys.basic.ip_proto;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
hash_keys.tags.flow_label = keys.tags.flow_label;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
hash_keys.ports.src = keys.ports.src;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
hash_keys.ports.dst = keys.ports.dst;
*p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION);
return fib_multipath_hash_from_keys(net, &hash_keys);
}
static u32 rt6_multipath_custom_hash_inner(const struct net *net,
const struct sk_buff *skb,
bool has_inner)
{
u32 hash_fields = ip6_multipath_hash_fields(net);
struct flow_keys keys, hash_keys;
/* We assume the packet carries an encapsulation, but if none was
* encountered during dissection of the outer flow, then there is no
* point in calling the flow dissector again.
*/
if (!has_inner)
return 0;
if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK))
return 0;
memset(&hash_keys, 0, sizeof(hash_keys));
skb_flow_dissect_flow_keys(skb, &keys, 0);
if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION))
return 0;
if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst;
} else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP)
hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP)
hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL)
hash_keys.tags.flow_label = keys.tags.flow_label;
}
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO)
hash_keys.basic.ip_proto = keys.basic.ip_proto;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT)
hash_keys.ports.src = keys.ports.src;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT)
hash_keys.ports.dst = keys.ports.dst;
return fib_multipath_hash_from_keys(net, &hash_keys);
}
static u32 rt6_multipath_custom_hash_skb(const struct net *net,
const struct sk_buff *skb)
{
u32 mhash, mhash_inner;
bool has_inner = true;
mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner);
mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner);
return jhash_2words(mhash, mhash_inner, 0);
}
static u32 rt6_multipath_custom_hash_fl6(const struct net *net,
const struct flowi6 *fl6)
{
u32 hash_fields = ip6_multipath_hash_fields(net);
struct flow_keys hash_keys;
if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
return 0;
memset(&hash_keys, 0, sizeof(hash_keys));
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP)
hash_keys.addrs.v6addrs.src = fl6->saddr;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP)
hash_keys.addrs.v6addrs.dst = fl6->daddr;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO)
hash_keys.basic.ip_proto = fl6->flowi6_proto;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL)
hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT)
hash_keys.ports.src = fl6->fl6_sport;
if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT)
hash_keys.ports.dst = fl6->fl6_dport;
return fib_multipath_hash_from_keys(net, &hash_keys);
}
/* if skb is set it will be used and fl6 can be NULL */
u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
const struct sk_buff *skb, struct flow_keys *flkeys)
{
struct flow_keys hash_keys;
u32 mhash = 0;
switch (ip6_multipath_hash_policy(net)) {
case 0:
memset(&hash_keys, 0, sizeof(hash_keys));
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
if (skb) {
ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
} else {
hash_keys.addrs.v6addrs.src = fl6->saddr;
hash_keys.addrs.v6addrs.dst = fl6->daddr;
hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
hash_keys.basic.ip_proto = fl6->flowi6_proto;
}
mhash = fib_multipath_hash_from_keys(net, &hash_keys);
break;
case 1:
if (skb) {
unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
struct flow_keys keys;
/* short-circuit if we already have L4 hash present */
if (skb->l4_hash)
return skb_get_hash_raw(skb) >> 1;
memset(&hash_keys, 0, sizeof(hash_keys));
if (!flkeys) {
skb_flow_dissect_flow_keys(skb, &keys, flag);
flkeys = &keys;
}
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
hash_keys.ports.src = flkeys->ports.src;
hash_keys.ports.dst = flkeys->ports.dst;
hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
} else {
memset(&hash_keys, 0, sizeof(hash_keys));
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
hash_keys.addrs.v6addrs.src = fl6->saddr;
hash_keys.addrs.v6addrs.dst = fl6->daddr;
hash_keys.ports.src = fl6->fl6_sport;
hash_keys.ports.dst = fl6->fl6_dport;
hash_keys.basic.ip_proto = fl6->flowi6_proto;
}
mhash = fib_multipath_hash_from_keys(net, &hash_keys);
break;
case 2:
memset(&hash_keys, 0, sizeof(hash_keys));
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
if (skb) {
struct flow_keys keys;
if (!flkeys) {
skb_flow_dissect_flow_keys(skb, &keys, 0);
flkeys = &keys;
}
/* Inner can be v4 or v6 */
if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
} else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
hash_keys.tags.flow_label = flkeys->tags.flow_label;
hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
} else {
/* Same as case 0 */
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
}
} else {
/* Same as case 0 */
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
hash_keys.addrs.v6addrs.src = fl6->saddr;
hash_keys.addrs.v6addrs.dst = fl6->daddr;
hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
hash_keys.basic.ip_proto = fl6->flowi6_proto;
}
mhash = fib_multipath_hash_from_keys(net, &hash_keys);
break;
case 3:
if (skb)
mhash = rt6_multipath_custom_hash_skb(net, skb);
else
mhash = rt6_multipath_custom_hash_fl6(net, fl6);
break;
}
return mhash >> 1;
}
/* Called with rcu held */
void ip6_route_input(struct sk_buff *skb)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
struct net *net = dev_net(skb->dev);
int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF;
struct ip_tunnel_info *tun_info;
struct flowi6 fl6 = {
.flowi6_iif = skb->dev->ifindex,
.daddr = iph->daddr,
.saddr = iph->saddr,
.flowlabel = ip6_flowinfo(iph),
.flowi6_mark = skb->mark,
.flowi6_proto = iph->nexthdr,
};
struct flow_keys *flkeys = NULL, _flkeys;
tun_info = skb_tunnel_info(skb);
if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
flkeys = &_flkeys;
if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
skb_dst_drop(skb);
skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev,
&fl6, skb, flags));
}
INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net,
struct fib6_table *table,
struct flowi6 *fl6,
const struct sk_buff *skb,
int flags)
{
return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
}
static struct dst_entry *ip6_route_output_flags_noref(struct net *net,
const struct sock *sk,
struct flowi6 *fl6,
int flags)
{
bool any_src;
if (ipv6_addr_type(&fl6->daddr) &
(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
struct dst_entry *dst;
/* This function does not take refcnt on the dst */
dst = l3mdev_link_scope_lookup(net, fl6);
if (dst)
return dst;
}
fl6->flowi6_iif = LOOPBACK_IFINDEX;
flags |= RT6_LOOKUP_F_DST_NOREF;
any_src = ipv6_addr_any(&fl6->saddr);
if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
(fl6->flowi6_oif && any_src))
flags |= RT6_LOOKUP_F_IFACE;
if (!any_src)
flags |= RT6_LOOKUP_F_HAS_SADDR;
else if (sk)
flags |= rt6_srcprefs2flags(READ_ONCE(inet6_sk(sk)->srcprefs));
return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
}
struct dst_entry *ip6_route_output_flags(struct net *net,
const struct sock *sk,
struct flowi6 *fl6,
int flags)
{
struct dst_entry *dst;
struct rt6_info *rt6;
rcu_read_lock();
dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
rt6 = dst_rt6_info(dst);
/* For dst cached in uncached_list, refcnt is already taken. */
if (list_empty(&rt6->dst.rt_uncached) && !dst_hold_safe(dst)) {
dst = &net->ipv6.ip6_null_entry->dst;
dst_hold(dst);
}
rcu_read_unlock();
return dst;
}
EXPORT_SYMBOL_GPL(ip6_route_output_flags);
struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
{
struct rt6_info *rt, *ort = dst_rt6_info(dst_orig);
struct net_device *loopback_dev = net->loopback_dev;
struct dst_entry *new = NULL;
rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev,
DST_OBSOLETE_DEAD, 0);
if (rt) {
rt6_info_init(rt);
atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
new = &rt->dst;
new->__use = 1;
new->input = dst_discard;
new->output = dst_discard_out;
dst_copy_metrics(new, &ort->dst);
rt->rt6i_idev = in6_dev_get(loopback_dev);
rt->rt6i_gateway = ort->rt6i_gateway;
rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
#ifdef CONFIG_IPV6_SUBTREES
memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
#endif
}
dst_release(dst_orig);
return new ? new : ERR_PTR(-ENOMEM);
}
/*
* Destination cache support functions
*/
static bool fib6_check(struct fib6_info *f6i, u32 cookie)
{
u32 rt_cookie = 0;
if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
return false;
if (fib6_check_expired(f6i))
return false;
return true;
}
static struct dst_entry *rt6_check(struct rt6_info *rt,
struct fib6_info *from,
u32 cookie)
{
u32 rt_cookie = 0;
if (!from || !fib6_get_cookie_safe(from, &rt_cookie) ||
rt_cookie != cookie)
return NULL;
if (rt6_check_expired(rt))
return NULL;
return &rt->dst;
}
static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
struct fib6_info *from,
u32 cookie)
{
if (!__rt6_check_expired(rt) &&
rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
fib6_check(from, cookie))
return &rt->dst;
else
return NULL;
}
INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst,
u32 cookie)
{
struct dst_entry *dst_ret;
struct fib6_info *from;
struct rt6_info *rt;
rt = dst_rt6_info(dst);
if (rt->sernum)
return rt6_is_valid(rt) ? dst : NULL;
rcu_read_lock();
/* All IPV6 dsts are created with ->obsolete set to the value
* DST_OBSOLETE_FORCE_CHK which forces validation calls down
* into this function always.
*/
from = rcu_dereference(rt->from);
if (from && (rt->rt6i_flags & RTF_PCPU ||
unlikely(!list_empty(&rt->dst.rt_uncached))))
dst_ret = rt6_dst_from_check(rt, from, cookie);
else
dst_ret = rt6_check(rt, from, cookie);
rcu_read_unlock();
return dst_ret;
}
EXPORT_INDIRECT_CALLABLE(ip6_dst_check);
static void ip6_negative_advice(struct sock *sk,
struct dst_entry *dst)
{
struct rt6_info *rt = dst_rt6_info(dst);
if (rt->rt6i_flags & RTF_CACHE) {
rcu_read_lock();
if (rt6_check_expired(rt)) {
/* counteract the dst_release() in sk_dst_reset() */
dst_hold(dst);
sk_dst_reset(sk);
rt6_remove_exception_rt(rt);
}
rcu_read_unlock();
return;
}
sk_dst_reset(sk);
}
static void ip6_link_failure(struct sk_buff *skb)
{
struct rt6_info *rt;
icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
rt = dst_rt6_info(skb_dst(skb));
if (rt) {
rcu_read_lock();
if (rt->rt6i_flags & RTF_CACHE) {
rt6_remove_exception_rt(rt);
} else {
struct fib6_info *from;
struct fib6_node *fn;
from = rcu_dereference(rt->from);
if (from) {
fn = rcu_dereference(from->fib6_node);
if (fn && (rt->rt6i_flags & RTF_DEFAULT))
WRITE_ONCE(fn->fn_sernum, -1);
}
}
rcu_read_unlock();
}
}
static void rt6_update_expires(struct rt6_info *rt0, int timeout)
{
if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
struct fib6_info *from;
rcu_read_lock();
from = rcu_dereference(rt0->from);
if (from)
rt0->dst.expires = from->expires;
rcu_read_unlock();
}
dst_set_expires(&rt0->dst, timeout);
rt0->rt6i_flags |= RTF_EXPIRES;
}
static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
{
struct net *net = dev_net(rt->dst.dev);
dst_metric_set(&rt->dst, RTAX_MTU, mtu);
rt->rt6i_flags |= RTF_MODIFIED;
rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
}
static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
{
return !(rt->rt6i_flags & RTF_CACHE) &&
(rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
}
static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
const struct ipv6hdr *iph, u32 mtu,
bool confirm_neigh)
{
const struct in6_addr *daddr, *saddr;
struct rt6_info *rt6 = dst_rt6_info(dst);
/* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU)
* IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it.
* [see also comment in rt6_mtu_change_route()]
*/
if (iph) {
daddr = &iph->daddr;
saddr = &iph->saddr;
} else if (sk) {
daddr = &sk->sk_v6_daddr;
saddr = &inet6_sk(sk)->saddr;
} else {
daddr = NULL;
saddr = NULL;
}
if (confirm_neigh)
dst_confirm_neigh(dst, daddr);
if (mtu < IPV6_MIN_MTU)
return;
if (mtu >= dst_mtu(dst))
return;
if (!rt6_cache_allowed_for_pmtu(rt6)) {
rt6_do_update_pmtu(rt6, mtu);
/* update rt6_ex->stamp for cache */
if (rt6->rt6i_flags & RTF_CACHE)
rt6_update_exception_stamp_rt(rt6);
} else if (daddr) {
struct fib6_result res = {};
struct rt6_info *nrt6;
rcu_read_lock();
res.f6i = rcu_dereference(rt6->from);
if (!res.f6i)
goto out_unlock;
res.fib6_flags = res.f6i->fib6_flags;
res.fib6_type = res.f6i->fib6_type;
if (res.f6i->nh) {
struct fib6_nh_match_arg arg = {
.dev = dst->dev,
.gw = &rt6->rt6i_gateway,
};
nexthop_for_each_fib6_nh(res.f6i->nh,
fib6_nh_find_match, &arg);
/* fib6_info uses a nexthop that does not have fib6_nh
* using the dst->dev + gw. Should be impossible.
*/
if (!arg.match)
goto out_unlock;
res.nh = arg.match;
} else {
res.nh = res.f6i->fib6_nh;
}
nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
if (nrt6) {
rt6_do_update_pmtu(nrt6, mtu);
if (rt6_insert_exception(nrt6, &res))
dst_release_immediate(&nrt6->dst);
}
out_unlock:
rcu_read_unlock();
}
}
static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
struct sk_buff *skb, u32 mtu,
bool confirm_neigh)
{
__ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu,
confirm_neigh);
}
void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
int oif, u32 mark, kuid_t uid)
{
const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
struct dst_entry *dst;
struct flowi6 fl6 = {
.flowi6_oif = oif,
.flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
.daddr = iph->daddr,
.saddr = iph->saddr,
.flowlabel = ip6_flowinfo(iph),
.flowi6_uid = uid,
};
dst = ip6_route_output(net, NULL, &fl6);
if (!dst->error)
__ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true);
dst_release(dst);
}
EXPORT_SYMBOL_GPL(ip6_update_pmtu);
void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
{
int oif = sk->sk_bound_dev_if;
struct dst_entry *dst;
if (!oif && skb->dev)
oif = l3mdev_master_ifindex(skb->dev);
ip6_update_pmtu(skb, sock_net(sk), mtu, oif, READ_ONCE(sk->sk_mark),
sk->sk_uid);
dst = __sk_dst_get(sk);
if (!dst || !dst->obsolete ||
dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
return;
bh_lock_sock(sk);
if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
ip6_datagram_dst_update(sk, false);
bh_unlock_sock(sk);
}
EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
const struct flowi6 *fl6)
{
#ifdef CONFIG_IPV6_SUBTREES
struct ipv6_pinfo *np = inet6_sk(sk);
#endif
ip6_dst_store(sk, dst,
ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
&sk->sk_v6_daddr : NULL,
#ifdef CONFIG_IPV6_SUBTREES
ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
&np->saddr :
#endif
NULL);
}
static bool ip6_redirect_nh_match(const struct fib6_result *res,
struct flowi6 *fl6,
const struct in6_addr *gw,
struct rt6_info **ret)
{
const struct fib6_nh *nh = res->nh;
if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family ||
fl6->flowi6_oif != nh->fib_nh_dev->ifindex)
return false;
/* rt_cache's gateway might be different from its 'parent'
* in the case of an ip redirect.
* So we keep searching in the exception table if the gateway
* is different.
*/
if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) {
struct rt6_info *rt_cache;
rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr);
if (rt_cache &&
ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) {
*ret = rt_cache;
return true;
}
return false;
}
return true;
}
struct fib6_nh_rd_arg {
struct fib6_result *res;
struct flowi6 *fl6;
const struct in6_addr *gw;
struct rt6_info **ret;
};
static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg)
{
struct fib6_nh_rd_arg *arg = _arg;
arg->res->nh = nh;
return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret);
}
/* Handle redirects */
struct ip6rd_flowi {
struct flowi6 fl6;
struct in6_addr gateway;
};
INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net,
struct fib6_table *table,
struct flowi6 *fl6,
const struct sk_buff *skb,
int flags)
{
struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
struct rt6_info *ret = NULL;
struct fib6_result res = {};
struct fib6_nh_rd_arg arg = {
.res = &res,
.fl6 = fl6,
.gw = &rdfl->gateway,
.ret = &ret
};
struct fib6_info *rt;
struct fib6_node *fn;
/* Get the "current" route for this destination and
* check if the redirect has come from appropriate router.
*
* RFC 4861 specifies that redirects should only be
* accepted if they come from the nexthop to the target.
* Due to the way the routes are chosen, this notion
* is a bit fuzzy and one might need to check all possible
* routes.
*/
rcu_read_lock();
fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
restart:
for_each_fib6_node_rt_rcu(fn) {
res.f6i = rt;
if (fib6_check_expired(rt))
continue;
if (rt->fib6_flags & RTF_REJECT)
break;
if (unlikely(rt->nh)) {
if (nexthop_is_blackhole(rt->nh))
continue;
/* on match, res->nh is filled in and potentially ret */
if (nexthop_for_each_fib6_nh(rt->nh,
fib6_nh_redirect_match,
&arg))
goto out;
} else {
res.nh = rt->fib6_nh;
if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway,
&ret))
goto out;
}
}
if (!rt)
rt = net->ipv6.fib6_null_entry;
else if (rt->fib6_flags & RTF_REJECT) {
ret = net->ipv6.ip6_null_entry;
goto out;
}
if (rt == net->ipv6.fib6_null_entry) {
fn = fib6_backtrack(fn, &fl6->saddr);
if (fn)
goto restart;
}
res.f6i = rt;
res.nh = rt->fib6_nh;
out:
if (ret) {
ip6_hold_safe(net, &ret);
} else {
res.fib6_flags = res.f6i->fib6_flags;
res.fib6_type = res.f6i->fib6_type;
ret = ip6_create_rt_rcu(&res);
}
rcu_read_unlock();
trace_fib6_table_lookup(net, &res, table, fl6);
return ret;
};
static struct dst_entry *ip6_route_redirect(struct net *net,
const struct flowi6 *fl6,
const struct sk_buff *skb,
const struct in6_addr *gateway)
{
int flags = RT6_LOOKUP_F_HAS_SADDR;
struct ip6rd_flowi rdfl;
rdfl.fl6 = *fl6;
rdfl.gateway = *gateway;
return fib6_rule_lookup(net, &rdfl.fl6, skb,
flags, __ip6_route_redirect);
}
void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
kuid_t uid)
{
const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
struct dst_entry *dst;
struct flowi6 fl6 = {
.flowi6_iif = LOOPBACK_IFINDEX,
.flowi6_oif = oif,
.flowi6_mark = mark,
.daddr = iph->daddr,
.saddr = iph->saddr,
.flowlabel = ip6_flowinfo(iph),
.flowi6_uid = uid,
};
dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
rt6_do_redirect(dst, NULL, skb);
dst_release(dst);
}
EXPORT_SYMBOL_GPL(ip6_redirect);
void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
struct dst_entry *dst;
struct flowi6 fl6 = {
.flowi6_iif = LOOPBACK_IFINDEX,
.flowi6_oif = oif,
.daddr = msg->dest,
.saddr = iph->daddr,
.flowi6_uid = sock_net_uid(net, NULL),
};
dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
rt6_do_redirect(dst, NULL, skb);
dst_release(dst);
}
void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
{
ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if,
READ_ONCE(sk->sk_mark), sk->sk_uid);
}
EXPORT_SYMBOL_GPL(ip6_sk_redirect);
static unsigned int ip6_default_advmss(const struct dst_entry *dst)
{
struct net_device *dev = dst->dev;
unsigned int mtu = dst_mtu(dst);
struct net *net = dev_net(dev);
mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
/*
* Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
* corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
* IPV6_MAXPLEN is also valid and means: "any MSS,
* rely only on pmtu discovery"
*/
if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
mtu = IPV6_MAXPLEN;
return mtu;
}
INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst)
{
return ip6_dst_mtu_maybe_forward(dst, false);
}
EXPORT_INDIRECT_CALLABLE(ip6_mtu);
/* MTU selection:
* 1. mtu on route is locked - use it
* 2. mtu from nexthop exception
* 3. mtu from egress device
*
* based on ip6_dst_mtu_forward and exception logic of
* rt6_find_cached_rt; called with rcu_read_lock
*/
u32 ip6_mtu_from_fib6(const struct fib6_result *res,
const struct in6_addr *daddr,
const struct in6_addr *saddr)
{
const struct fib6_nh *nh = res->nh;
struct fib6_info *f6i = res->f6i;
struct inet6_dev *idev;
struct rt6_info *rt;
u32 mtu = 0;
if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
mtu = f6i->fib6_pmtu;
if (mtu)
goto out;
}
rt = rt6_find_cached_rt(res, daddr, saddr);
if (unlikely(rt)) {
mtu = dst_metric_raw(&rt->dst, RTAX_MTU);
} else {
struct net_device *dev = nh->fib_nh_dev;
mtu = IPV6_MIN_MTU;
idev = __in6_dev_get(dev);
if (idev)
mtu = max_t(u32, mtu, READ_ONCE(idev->cnf.mtu6));
}
mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
out:
return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
}
struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
struct flowi6 *fl6)
{
struct dst_entry *dst;
struct rt6_info *rt;
struct inet6_dev *idev = in6_dev_get(dev);
struct net *net = dev_net(dev);
if (unlikely(!idev))
return ERR_PTR(-ENODEV);
rt = ip6_dst_alloc(net, dev, 0);
if (unlikely(!rt)) {
in6_dev_put(idev);
dst = ERR_PTR(-ENOMEM);
goto out;
}
rt->dst.input = ip6_input;
rt->dst.output = ip6_output;
rt->rt6i_gateway = fl6->daddr;
rt->rt6i_dst.addr = fl6->daddr;
rt->rt6i_dst.plen = 128;
rt->rt6i_idev = idev;
dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
/* Add this dst into uncached_list so that rt6_disable_ip() can
* do proper release of the net_device
*/
rt6_uncached_list_add(rt);
dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
out:
return dst;
}
static void ip6_dst_gc(struct dst_ops *ops)
{
struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
unsigned int val;
int entries;
if (time_after(rt_last_gc + rt_min_interval, jiffies))
goto out;
fib6_run_gc(atomic_inc_return(&net->ipv6.ip6_rt_gc_expire), net, true);
entries = dst_entries_get_slow(ops);
if (entries < ops->gc_thresh)
atomic_set(&net->ipv6.ip6_rt_gc_expire, rt_gc_timeout >> 1);
out:
val = atomic_read(&net->ipv6.ip6_rt_gc_expire);
atomic_set(&net->ipv6.ip6_rt_gc_expire, val - (val >> rt_elasticity));
}
static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
const struct in6_addr *gw_addr, u32 tbid,
int flags, struct fib6_result *res)
{
struct flowi6 fl6 = {
.flowi6_oif = cfg->fc_ifindex,
.daddr = *gw_addr,
.saddr = cfg->fc_prefsrc,
};
struct fib6_table *table;
int err;
table = fib6_get_table(net, tbid);
if (!table)
return -EINVAL;
if (!ipv6_addr_any(&cfg->fc_prefsrc))
flags |= RT6_LOOKUP_F_HAS_SADDR;
flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags);
if (!err && res->f6i != net->ipv6.fib6_null_entry)
fib6_select_path(net, res, &fl6, cfg->fc_ifindex,
cfg->fc_ifindex != 0, NULL, flags);
return err;
}
static int ip6_route_check_nh_onlink(struct net *net,
struct fib6_config *cfg,
const struct net_device *dev,
struct netlink_ext_ack *extack)
{
u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
const struct in6_addr *gw_addr = &cfg->fc_gateway;
struct fib6_result res = {};
int err;
err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res);
if (!err && !(res.fib6_flags & RTF_REJECT) &&
/* ignore match if it is the default route */
!ipv6_addr_any(&res.f6i->fib6_dst.addr) &&
(res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) {
NL_SET_ERR_MSG(extack,
"Nexthop has invalid gateway or device mismatch");
err = -EINVAL;
}
return err;
}
static int ip6_route_check_nh(struct net *net,
struct fib6_config *cfg,
struct net_device **_dev,
netdevice_tracker *dev_tracker,
struct inet6_dev **idev)
{
const struct in6_addr *gw_addr = &cfg->fc_gateway;
struct net_device *dev = _dev ? *_dev : NULL;
int flags = RT6_LOOKUP_F_IFACE;
struct fib6_result res = {};
int err = -EHOSTUNREACH;
if (cfg->fc_table) {
err = ip6_nh_lookup_table(net, cfg, gw_addr,
cfg->fc_table, flags, &res);
/* gw_addr can not require a gateway or resolve to a reject
* route. If a device is given, it must match the result.
*/
if (err || res.fib6_flags & RTF_REJECT ||
res.nh->fib_nh_gw_family ||
(dev && dev != res.nh->fib_nh_dev))
err = -EHOSTUNREACH;
}
if (err < 0) {
struct flowi6 fl6 = {
.flowi6_oif = cfg->fc_ifindex,
.daddr = *gw_addr,
};
err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags);
if (err || res.fib6_flags & RTF_REJECT ||
res.nh->fib_nh_gw_family)
err = -EHOSTUNREACH;
if (err)
return err;
fib6_select_path(net, &res, &fl6, cfg->fc_ifindex,
cfg->fc_ifindex != 0, NULL, flags);
}
err = 0;
if (dev) {
if (dev != res.nh->fib_nh_dev)
err = -EHOSTUNREACH;
} else {
*_dev = dev = res.nh->fib_nh_dev;
netdev_hold(dev, dev_tracker, GFP_ATOMIC);
*idev = in6_dev_get(dev);
}
return err;
}
static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
struct net_device **_dev,
netdevice_tracker *dev_tracker,
struct inet6_dev **idev,
struct netlink_ext_ack *extack)
{
const struct in6_addr *gw_addr = &cfg->fc_gateway;
int gwa_type = ipv6_addr_type(gw_addr);
bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
const struct net_device *dev = *_dev;
bool need_addr_check = !dev;
int err = -EINVAL;
/* if gw_addr is local we will fail to detect this in case
* address is still TENTATIVE (DAD in progress). rt6_lookup()
* will return already-added prefix route via interface that
* prefix route was assigned to, which might be non-loopback.
*/
if (dev &&
ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
goto out;
}
if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
/* IPv6 strictly inhibits using not link-local
* addresses as nexthop address.
* Otherwise, router will not able to send redirects.
* It is very good, but in some (rare!) circumstances
* (SIT, PtP, NBMA NOARP links) it is handy to allow
* some exceptions. --ANK
* We allow IPv4-mapped nexthops to support RFC4798-type
* addressing
*/
if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
NL_SET_ERR_MSG(extack, "Invalid gateway address");
goto out;
}
rcu_read_lock();
if (cfg->fc_flags & RTNH_F_ONLINK)
err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
else
err = ip6_route_check_nh(net, cfg, _dev, dev_tracker,
idev);
rcu_read_unlock();
if (err)
goto out;
}
/* reload in case device was changed */
dev = *_dev;
err = -EINVAL;
if (!dev) {
NL_SET_ERR_MSG(extack, "Egress device not specified");
goto out;
} else if (dev->flags & IFF_LOOPBACK) {
NL_SET_ERR_MSG(extack,
"Egress device can not be loopback device for this route");
goto out;
}
/* if we did not check gw_addr above, do so now that the
* egress device has been resolved.
*/
if (need_addr_check &&
ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
goto out;
}
err = 0;
out:
return err;
}
static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
{
if ((flags & RTF_REJECT) ||
(dev && (dev->flags & IFF_LOOPBACK) &&
!(addr_type & IPV6_ADDR_LOOPBACK) &&
!(flags & (RTF_ANYCAST | RTF_LOCAL))))
return true;
return false;
}
int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
struct fib6_config *cfg, gfp_t gfp_flags,
struct netlink_ext_ack *extack)
{
netdevice_tracker *dev_tracker = &fib6_nh->fib_nh_dev_tracker;
struct net_device *dev = NULL;
struct inet6_dev *idev = NULL;
int addr_type;
int err;
fib6_nh->fib_nh_family = AF_INET6;
#ifdef CONFIG_IPV6_ROUTER_PREF
fib6_nh->last_probe = jiffies;
#endif
if (cfg->fc_is_fdb) {
fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
fib6_nh->fib_nh_gw_family = AF_INET6;
return 0;
}
err = -ENODEV;
if (cfg->fc_ifindex) {
dev = netdev_get_by_index(net, cfg->fc_ifindex,
dev_tracker, gfp_flags);
if (!dev)
goto out;
idev = in6_dev_get(dev);
if (!idev)
goto out;
}
if (cfg->fc_flags & RTNH_F_ONLINK) {
if (!dev) {
NL_SET_ERR_MSG(extack,
"Nexthop device required for onlink");
goto out;
}
if (!(dev->flags & IFF_UP)) {
NL_SET_ERR_MSG(extack, "Nexthop device is not up");
err = -ENETDOWN;
goto out;
}
fib6_nh->fib_nh_flags |= RTNH_F_ONLINK;
}
fib6_nh->fib_nh_weight = 1;
/* We cannot add true routes via loopback here,
* they would result in kernel looping; promote them to reject routes
*/
addr_type = ipv6_addr_type(&cfg->fc_dst);
if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) {
/* hold loopback dev/idev if we haven't done so. */
if (dev != net->loopback_dev) {
if (dev) {
netdev_put(dev, dev_tracker);
in6_dev_put(idev);
}
dev = net->loopback_dev;
netdev_hold(dev, dev_tracker, gfp_flags);
idev = in6_dev_get(dev);
if (!idev) {
err = -ENODEV;
goto out;
}
}
goto pcpu_alloc;
}
if (cfg->fc_flags & RTF_GATEWAY) {
err = ip6_validate_gw(net, cfg, &dev, dev_tracker,
&idev, extack);
if (err)
goto out;
fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
fib6_nh->fib_nh_gw_family = AF_INET6;
}
err = -ENODEV;
if (!dev)
goto out;
if (!idev || idev->cnf.disable_ipv6) {
NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
err = -EACCES;
goto out;
}
if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
NL_SET_ERR_MSG(extack, "Nexthop device is not up");
err = -ENETDOWN;
goto out;
}
if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
!netif_carrier_ok(dev))
fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap,
cfg->fc_encap_type, cfg, gfp_flags, extack);
if (err)
goto out;
pcpu_alloc:
fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
if (!fib6_nh->rt6i_pcpu) {
err = -ENOMEM;
goto out;
}
fib6_nh->fib_nh_dev = dev;
fib6_nh->fib_nh_oif = dev->ifindex;
err = 0;
out:
if (idev)
in6_dev_put(idev);
if (err) {
lwtstate_put(fib6_nh->fib_nh_lws);
fib6_nh->fib_nh_lws = NULL;
netdev_put(dev, dev_tracker);
}
return err;
}
void fib6_nh_release(struct fib6_nh *fib6_nh)
{
struct rt6_exception_bucket *bucket;
rcu_read_lock();
fib6_nh_flush_exceptions(fib6_nh, NULL);
bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL);
if (bucket) {
rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL);
kfree(bucket);
}
rcu_read_unlock();
fib6_nh_release_dsts(fib6_nh);
free_percpu(fib6_nh->rt6i_pcpu);
fib_nh_common_release(&fib6_nh->nh_common);
}
void fib6_nh_release_dsts(struct fib6_nh *fib6_nh)
{
int cpu;
if (!fib6_nh->rt6i_pcpu)
return;
for_each_possible_cpu(cpu) {
struct rt6_info *pcpu_rt, **ppcpu_rt;
ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
pcpu_rt = xchg(ppcpu_rt, NULL);
if (pcpu_rt) {
dst_dev_put(&pcpu_rt->dst);
dst_release(&pcpu_rt->dst);
}
}
}
static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
gfp_t gfp_flags,
struct netlink_ext_ack *extack)
{
struct net *net = cfg->fc_nlinfo.nl_net;
struct fib6_info *rt = NULL;
struct nexthop *nh = NULL;
struct fib6_table *table;
struct fib6_nh *fib6_nh;
int err = -EINVAL;
int addr_type;
/* RTF_PCPU is an internal flag; can not be set by userspace */
if (cfg->fc_flags & RTF_PCPU) {
NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
goto out;
}
/* RTF_CACHE is an internal flag; can not be set by userspace */
if (cfg->fc_flags & RTF_CACHE) {
NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
goto out;
}
if (cfg->fc_type > RTN_MAX) {
NL_SET_ERR_MSG(extack, "Invalid route type");
goto out;
}
if (cfg->fc_dst_len > 128) {
NL_SET_ERR_MSG(extack, "Invalid prefix length");
goto out;
}
if (cfg->fc_src_len > 128) {
NL_SET_ERR_MSG(extack, "Invalid source address length");
goto out;
}
#ifndef CONFIG_IPV6_SUBTREES
if (cfg->fc_src_len) {
NL_SET_ERR_MSG(extack,
"Specifying source address requires IPV6_SUBTREES to be enabled");
goto out;
}
#endif
if (cfg->fc_nh_id) {
nh = nexthop_find_by_id(net, cfg->fc_nh_id);
if (!nh) {
NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
goto out;
}
err = fib6_check_nexthop(nh, cfg, extack);
if (err)
goto out;
}
err = -ENOBUFS;
if (cfg->fc_nlinfo.nlh &&
!(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
table = fib6_get_table(net, cfg->fc_table);
if (!table) {
pr_warn("NLM_F_CREATE should be specified when creating new route\n");
table = fib6_new_table(net, cfg->fc_table);
}
} else {
table = fib6_new_table(net, cfg->fc_table);
}
if (!table)
goto out;
err = -ENOMEM;
rt = fib6_info_alloc(gfp_flags, !nh);
if (!rt)
goto out;
rt->fib6_metrics = ip_fib_metrics_init(cfg->fc_mx, cfg->fc_mx_len,
extack);
if (IS_ERR(rt->fib6_metrics)) {
err = PTR_ERR(rt->fib6_metrics);
/* Do not leave garbage there. */
rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
goto out_free;
}
if (cfg->fc_flags & RTF_ADDRCONF)
rt->dst_nocount = true;
if (cfg->fc_flags & RTF_EXPIRES)
fib6_set_expires(rt, jiffies +
clock_t_to_jiffies(cfg->fc_expires));
if (cfg->fc_protocol == RTPROT_UNSPEC)
cfg->fc_protocol = RTPROT_BOOT;
rt->fib6_protocol = cfg->fc_protocol;
rt->fib6_table = table;
rt->fib6_metric = cfg->fc_metric;
rt->fib6_type = cfg->fc_type ? : RTN_UNICAST;
rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;
ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
rt->fib6_dst.plen = cfg->fc_dst_len;
#ifdef CONFIG_IPV6_SUBTREES
ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
rt->fib6_src.plen = cfg->fc_src_len;
#endif
if (nh) {
if (rt->fib6_src.plen) {
NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
goto out_free;
}
if (!nexthop_get(nh)) {
NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
goto out_free;
}
rt->nh = nh;
fib6_nh = nexthop_fib6_nh(rt->nh);
} else {
err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack);
if (err)
goto out;
fib6_nh = rt->fib6_nh;
/* We cannot add true routes via loopback here, they would
* result in kernel looping; promote them to reject routes
*/
addr_type = ipv6_addr_type(&cfg->fc_dst);
if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev,
addr_type))
rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
}
if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
struct net_device *dev = fib6_nh->fib_nh_dev;
if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
NL_SET_ERR_MSG(extack, "Invalid source address");
err = -EINVAL;
goto out;
}
rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
rt->fib6_prefsrc.plen = 128;
} else
rt->fib6_prefsrc.plen = 0;
return rt;
out:
fib6_info_release(rt);
return ERR_PTR(err);
out_free:
ip_fib_metrics_put(rt->fib6_metrics);
kfree(rt);
return ERR_PTR(err);
}
int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
struct netlink_ext_ack *extack)
{
struct fib6_info *rt;
int err;
rt = ip6_route_info_create(cfg, gfp_flags, extack);
if (IS_ERR(rt))
return PTR_ERR(rt);
err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
fib6_info_release(rt);
return err;
}
static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
{
struct net *net = info->nl_net;
struct fib6_table *table;
int err;
if (rt == net->ipv6.fib6_null_entry) {
err = -ENOENT;
goto out;
}
table = rt->fib6_table;
spin_lock_bh(&table->tb6_lock);
err = fib6_del(rt, info);
spin_unlock_bh(&table->tb6_lock);
out:
fib6_info_release(rt);
return err;
}
int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify)
{
struct nl_info info = {
.nl_net = net,
.skip_notify = skip_notify
};
return __ip6_del_rt(rt, &info);
}
static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
{
struct nl_info *info = &cfg->fc_nlinfo;
struct net *net = info->nl_net;
struct sk_buff *skb = NULL;
struct fib6_table *table;
int err = -ENOENT;
if (rt == net->ipv6.fib6_null_entry)
goto out_put;
table = rt->fib6_table;
spin_lock_bh(&table->tb6_lock);
if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
struct fib6_info *sibling, *next_sibling;
struct fib6_node *fn;
/* prefer to send a single notification with all hops */
skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
if (skb) {
u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
if (rt6_fill_node(net, skb, rt, NULL,
NULL, NULL, 0, RTM_DELROUTE,
info->portid, seq, 0) < 0) {
kfree_skb(skb);
skb = NULL;
} else
info->skip_notify = 1;
}
/* 'rt' points to the first sibling route. If it is not the
* leaf, then we do not need to send a notification. Otherwise,
* we need to check if the last sibling has a next route or not
* and emit a replace or delete notification, respectively.
*/
info->skip_notify_kernel = 1;
fn = rcu_dereference_protected(rt->fib6_node,
lockdep_is_held(&table->tb6_lock));
if (rcu_access_pointer(fn->leaf) == rt) {
struct fib6_info *last_sibling, *replace_rt;
last_sibling = list_last_entry(&rt->fib6_siblings,
struct fib6_info,
fib6_siblings);
replace_rt = rcu_dereference_protected(
last_sibling->fib6_next,
lockdep_is_held(&table->tb6_lock));
if (replace_rt)
call_fib6_entry_notifiers_replace(net,
replace_rt);
else
call_fib6_multipath_entry_notifiers(net,
FIB_EVENT_ENTRY_DEL,
rt, rt->fib6_nsiblings,
NULL);
}
list_for_each_entry_safe(sibling, next_sibling,
&rt->fib6_siblings,
fib6_siblings) {
err = fib6_del(sibling, info);
if (err)
goto out_unlock;
}
}
err = fib6_del(rt, info);
out_unlock:
spin_unlock_bh(&table->tb6_lock);
out_put:
fib6_info_release(rt);
if (skb) {
rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
info->nlh, gfp_any());
}
return err;
}
static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
{
int rc = -ESRCH;
if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
goto out;
if (cfg->fc_flags & RTF_GATEWAY &&
!ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
goto out;
rc = rt6_remove_exception_rt(rt);
out:
return rc;
}
static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt,
struct fib6_nh *nh)
{
struct fib6_result res = {
.f6i = rt,
.nh = nh,
};
struct rt6_info *rt_cache;
rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src);
if (rt_cache)
return __ip6_del_cached_rt(rt_cache, cfg);
return 0;
}
struct fib6_nh_del_cached_rt_arg {
struct fib6_config *cfg;
struct fib6_info *f6i;
};
static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg)
{
struct fib6_nh_del_cached_rt_arg *arg = _arg;
int rc;
rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh);
return rc != -ESRCH ? rc : 0;
}
static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i)
{
struct fib6_nh_del_cached_rt_arg arg = {
.cfg = cfg,
.f6i = f6i
};
return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg);
}
static int ip6_route_del(struct fib6_config *cfg,
struct netlink_ext_ack *extack)
{
struct fib6_table *table;
struct fib6_info *rt;
struct fib6_node *fn;
int err = -ESRCH;
table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
if (!table) {
NL_SET_ERR_MSG(extack, "FIB table does not exist");
return err;
}
rcu_read_lock();
fn = fib6_locate(&table->tb6_root,
&cfg->fc_dst, cfg->fc_dst_len,
&cfg->fc_src, cfg->fc_src_len,
!(cfg->fc_flags & RTF_CACHE));
if (fn) {
for_each_fib6_node_rt_rcu(fn) {
struct fib6_nh *nh;
if (rt->nh && cfg->fc_nh_id &&
rt->nh->id != cfg->fc_nh_id)
continue;
if (cfg->fc_flags & RTF_CACHE) {
int rc = 0;
if (rt->nh) {
rc = ip6_del_cached_rt_nh(cfg, rt);
} else if (cfg->fc_nh_id) {
continue;
} else {
nh = rt->fib6_nh;
rc = ip6_del_cached_rt(cfg, rt, nh);
}
if (rc != -ESRCH) {
rcu_read_unlock();
return rc;
}
continue;
}
if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
continue;
if (cfg->fc_protocol &&
cfg->fc_protocol != rt->fib6_protocol)
continue;
if (rt->nh) {
if (!fib6_info_hold_safe(rt))
continue;
rcu_read_unlock();
return __ip6_del_rt(rt, &cfg->fc_nlinfo);
}
if (cfg->fc_nh_id)
continue;
nh = rt->fib6_nh;
if (cfg->fc_ifindex &&
(!nh->fib_nh_dev ||
nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
continue;
if (cfg->fc_flags & RTF_GATEWAY &&
!ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6))
continue;
if (!fib6_info_hold_safe(rt))
continue;
rcu_read_unlock();
/* if gateway was specified only delete the one hop */
if (cfg->fc_flags & RTF_GATEWAY)
return __ip6_del_rt(rt, &cfg->fc_nlinfo);
return __ip6_del_rt_siblings(rt, cfg);
}
}
rcu_read_unlock();
return err;
}
static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
{
struct netevent_redirect netevent;
struct rt6_info *rt, *nrt = NULL;
struct fib6_result res = {};
struct ndisc_options ndopts;
struct inet6_dev *in6_dev;
struct neighbour *neigh;
struct rd_msg *msg;
int optlen, on_link;
u8 *lladdr;
optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
optlen -= sizeof(*msg);
if (optlen < 0) {
net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
return;
}
msg = (struct rd_msg *)icmp6_hdr(skb);
if (ipv6_addr_is_multicast(&msg->dest)) {
net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
return;
}
on_link = 0;
if (ipv6_addr_equal(&msg->dest, &msg->target)) {
on_link = 1;
} else if (ipv6_addr_type(&msg->target) !=
(IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
return;
}
in6_dev = __in6_dev_get(skb->dev);
if (!in6_dev)
return;
if (READ_ONCE(in6_dev->cnf.forwarding) ||
!READ_ONCE(in6_dev->cnf.accept_redirects))
return;
/* RFC2461 8.1:
* The IP source address of the Redirect MUST be the same as the current
* first-hop router for the specified ICMP Destination Address.
*/
if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
return;
}
lladdr = NULL;
if (ndopts.nd_opts_tgt_lladdr) {
lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
skb->dev);
if (!lladdr) {
net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
return;
}
}
rt = dst_rt6_info(dst);
if (rt->rt6i_flags & RTF_REJECT) {
net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
return;
}
/* Redirect received -> path was valid.
* Look, redirects are sent only in response to data packets,
* so that this nexthop apparently is reachable. --ANK
*/
dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
if (!neigh)
return;
/*
* We have finally decided to accept it.
*/
ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
NEIGH_UPDATE_F_WEAK_OVERRIDE|
NEIGH_UPDATE_F_OVERRIDE|
(on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
NEIGH_UPDATE_F_ISROUTER)),
NDISC_REDIRECT, &ndopts);
rcu_read_lock();
res.f6i = rcu_dereference(rt->from);
if (!res.f6i)
goto out;
if (res.f6i->nh) {
struct fib6_nh_match_arg arg = {
.dev = dst->dev,
.gw = &rt->rt6i_gateway,
};
nexthop_for_each_fib6_nh(res.f6i->nh,
fib6_nh_find_match, &arg);
/* fib6_info uses a nexthop that does not have fib6_nh
* using the dst->dev. Should be impossible
*/
if (!arg.match)
goto out;
res.nh = arg.match;
} else {
res.nh = res.f6i->fib6_nh;
}
res.fib6_flags = res.f6i->fib6_flags;
res.fib6_type = res.f6i->fib6_type;
nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL);
if (!nrt)
goto out;
nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
if (on_link)
nrt->rt6i_flags &= ~RTF_GATEWAY;
nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
/* rt6_insert_exception() will take care of duplicated exceptions */
if (rt6_insert_exception(nrt, &res)) {
dst_release_immediate(&nrt->dst);
goto out;
}
netevent.old = &rt->dst;
netevent.new = &nrt->dst;
netevent.daddr = &msg->dest;
netevent.neigh = neigh;
call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
out:
rcu_read_unlock();
neigh_release(neigh);
}
#ifdef CONFIG_IPV6_ROUTE_INFO
static struct fib6_info *rt6_get_route_info(struct net *net,
const struct in6_addr *prefix, int prefixlen,
const struct in6_addr *gwaddr,
struct net_device *dev)
{
u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
int ifindex = dev->ifindex;
struct fib6_node *fn;
struct fib6_info *rt = NULL;
struct fib6_table *table;
table = fib6_get_table(net, tb_id);
if (!table)
return NULL;
rcu_read_lock();
fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
if (!fn)
goto out;
for_each_fib6_node_rt_rcu(fn) {
/* these routes do not use nexthops */
if (rt->nh)
continue;
if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex)
continue;
if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
!rt->fib6_nh->fib_nh_gw_family)
continue;
if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr))
continue;
if (!fib6_info_hold_safe(rt))
continue;
break;
}
out:
rcu_read_unlock();
return rt;
}
static struct fib6_info *rt6_add_route_info(struct net *net,
const struct in6_addr *prefix, int prefixlen,
const struct in6_addr *gwaddr,
struct net_device *dev,
unsigned int pref)
{
struct fib6_config cfg = {
.fc_metric = IP6_RT_PRIO_USER,
.fc_ifindex = dev->ifindex,
.fc_dst_len = prefixlen,
.fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
RTF_UP | RTF_PREF(pref),
.fc_protocol = RTPROT_RA,
.fc_type = RTN_UNICAST,
.fc_nlinfo.portid = 0,
.fc_nlinfo.nlh = NULL,
.fc_nlinfo.nl_net = net,
};
cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
cfg.fc_dst = *prefix;
cfg.fc_gateway = *gwaddr;
/* We should treat it as a default route if prefix length is 0. */
if (!prefixlen)
cfg.fc_flags |= RTF_DEFAULT;
ip6_route_add(&cfg, GFP_ATOMIC, NULL);
return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
}
#endif
struct fib6_info *rt6_get_dflt_router(struct net *net,
const struct in6_addr *addr,
struct net_device *dev)
{
u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
struct fib6_info *rt;
struct fib6_table *table;
table = fib6_get_table(net, tb_id);
if (!table)
return NULL;
rcu_read_lock();
for_each_fib6_node_rt_rcu(&table->tb6_root) {
struct fib6_nh *nh;
/* RA routes do not use nexthops */
if (rt->nh)
continue;
nh = rt->fib6_nh;
if (dev == nh->fib_nh_dev &&
((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
ipv6_addr_equal(&nh->fib_nh_gw6, addr))
break;
}
if (rt && !fib6_info_hold_safe(rt))
rt = NULL;
rcu_read_unlock();
return rt;
}
struct fib6_info *rt6_add_dflt_router(struct net *net,
const struct in6_addr *gwaddr,
struct net_device *dev,
unsigned int pref,
u32 defrtr_usr_metric,
int lifetime)
{
struct fib6_config cfg = {
.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
.fc_metric = defrtr_usr_metric,
.fc_ifindex = dev->ifindex,
.fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
.fc_protocol = RTPROT_RA,
.fc_type = RTN_UNICAST,
.fc_nlinfo.portid = 0,
.fc_nlinfo.nlh = NULL,
.fc_nlinfo.nl_net = net,
.fc_expires = jiffies_to_clock_t(lifetime * HZ),
};
cfg.fc_gateway = *gwaddr;
if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
struct fib6_table *table;
table = fib6_get_table(dev_net(dev), cfg.fc_table);
if (table)
table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
}
return rt6_get_dflt_router(net, gwaddr, dev);
}
static void __rt6_purge_dflt_routers(struct net *net,
struct fib6_table *table)
{
struct fib6_info *rt;
restart:
rcu_read_lock();
for_each_fib6_node_rt_rcu(&table->tb6_root) {
struct net_device *dev = fib6_info_nh_dev(rt);
struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
(!idev || idev->cnf.accept_ra != 2) &&
fib6_info_hold_safe(rt)) {
rcu_read_unlock();
ip6_del_rt(net, rt, false);
goto restart;
}
}
rcu_read_unlock();
table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
}
void rt6_purge_dflt_routers(struct net *net)
{
struct fib6_table *table;
struct hlist_head *head;
unsigned int h;
rcu_read_lock();
for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
head = &net->ipv6.fib_table_hash[h];
hlist_for_each_entry_rcu(table, head, tb6_hlist) {
if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
__rt6_purge_dflt_routers(net, table);
}
}
rcu_read_unlock();
}
static void rtmsg_to_fib6_config(struct net *net,
struct in6_rtmsg *rtmsg,
struct fib6_config *cfg)
{
*cfg = (struct fib6_config){
.fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
: RT6_TABLE_MAIN,
.fc_ifindex = rtmsg->rtmsg_ifindex,
.fc_metric = rtmsg->rtmsg_metric,
.fc_expires = rtmsg->rtmsg_info,
.fc_dst_len = rtmsg->rtmsg_dst_len,
.fc_src_len = rtmsg->rtmsg_src_len,
.fc_flags = rtmsg->rtmsg_flags,
.fc_type = rtmsg->rtmsg_type,
.fc_nlinfo.nl_net = net,
.fc_dst = rtmsg->rtmsg_dst,
.fc_src = rtmsg->rtmsg_src,
.fc_gateway = rtmsg->rtmsg_gateway,
};
}
int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg)
{
struct fib6_config cfg;
int err;
if (cmd != SIOCADDRT && cmd != SIOCDELRT)
return -EINVAL;
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
return -EPERM;
rtmsg_to_fib6_config(net, rtmsg, &cfg);
rtnl_lock();
switch (cmd) {
case SIOCADDRT:
/* Only do the default setting of fc_metric in route adding */
if (cfg.fc_metric == 0)
cfg.fc_metric = IP6_RT_PRIO_USER;
err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
break;
case SIOCDELRT:
err = ip6_route_del(&cfg, NULL);
break;
}
rtnl_unlock();
return err;
}
/*
* Drop the packet on the floor
*/
static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
{
struct dst_entry *dst = skb_dst(skb);
struct net *net = dev_net(dst->dev);
struct inet6_dev *idev;
SKB_DR(reason);
int type;
if (netif_is_l3_master(skb->dev) ||
dst->dev == net->loopback_dev)
idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
else
idev = ip6_dst_idev(dst);
switch (ipstats_mib_noroutes) {
case IPSTATS_MIB_INNOROUTES:
type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
if (type == IPV6_ADDR_ANY) {
SKB_DR_SET(reason, IP_INADDRERRORS);
IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
break;
}
SKB_DR_SET(reason, IP_INNOROUTES);
fallthrough;
case IPSTATS_MIB_OUTNOROUTES:
SKB_DR_OR(reason, IP_OUTNOROUTES);
IP6_INC_STATS(net, idev, ipstats_mib_noroutes);
break;
}
/* Start over by dropping the dst for l3mdev case */
if (netif_is_l3_master(skb->dev))
skb_dst_drop(skb);
icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
kfree_skb_reason(skb, reason);
return 0;
}
static int ip6_pkt_discard(struct sk_buff *skb)
{
return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
}
static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
{
skb->dev = skb_dst(skb)->dev;
return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
}
static int ip6_pkt_prohibit(struct sk_buff *skb)
{
return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
}
static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
{
skb->dev = skb_dst(skb)->dev;
return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
}
/*
* Allocate a dst for local (unicast / anycast) address.
*/
struct fib6_info *addrconf_f6i_alloc(struct net *net,
struct inet6_dev *idev,
const struct in6_addr *addr,
bool anycast, gfp_t gfp_flags,
struct netlink_ext_ack *extack)
{
struct fib6_config cfg = {
.fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
.fc_ifindex = idev->dev->ifindex,
.fc_flags = RTF_UP | RTF_NONEXTHOP,
.fc_dst = *addr,
.fc_dst_len = 128,
.fc_protocol = RTPROT_KERNEL,
.fc_nlinfo.nl_net = net,
.fc_ignore_dev_down = true,
};
struct fib6_info *f6i;
if (anycast) {
cfg.fc_type = RTN_ANYCAST;
cfg.fc_flags |= RTF_ANYCAST;
} else {
cfg.fc_type = RTN_LOCAL;
cfg.fc_flags |= RTF_LOCAL;
}
f6i = ip6_route_info_create(&cfg, gfp_flags, extack);
if (!IS_ERR(f6i)) {
f6i->dst_nocount = true;
if (!anycast &&
(READ_ONCE(net->ipv6.devconf_all->disable_policy) ||
READ_ONCE(idev->cnf.disable_policy)))
f6i->dst_nopolicy = true;
}
return f6i;
}
/* remove deleted ip from prefsrc entries */
struct arg_dev_net_ip {
struct net *net;
struct in6_addr *addr;
};
static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
{
struct net *net = ((struct arg_dev_net_ip *)arg)->net;
struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
if (!rt->nh &&
rt != net->ipv6.fib6_null_entry &&
ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr) &&
!ipv6_chk_addr(net, addr, rt->fib6_nh->fib_nh_dev, 0)) {
spin_lock_bh(&rt6_exception_lock);
/* remove prefsrc entry */
rt->fib6_prefsrc.plen = 0;
spin_unlock_bh(&rt6_exception_lock);
}
return 0;
}
void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
{
struct net *net = dev_net(ifp->idev->dev);
struct arg_dev_net_ip adni = {
.net = net,
.addr = &ifp->addr,
};
fib6_clean_all(net, fib6_remove_prefsrc, &adni);
}
#define RTF_RA_ROUTER (RTF_ADDRCONF | RTF_DEFAULT)
/* Remove routers and update dst entries when gateway turn into host. */
static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
{
struct in6_addr *gateway = (struct in6_addr *)arg;
struct fib6_nh *nh;
/* RA routes do not use nexthops */
if (rt->nh)
return 0;
nh = rt->fib6_nh;
if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6))
return -1;
/* Further clean up cached routes in exception table.
* This is needed because cached route may have a different
* gateway than its 'parent' in the case of an ip redirect.
*/
fib6_nh_exceptions_clean_tohost(nh, gateway);
return 0;
}
void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
{
fib6_clean_all(net, fib6_clean_tohost, gateway);
}
struct arg_netdev_event {
const struct net_device *dev;
union {
unsigned char nh_flags;
unsigned long event;
};
};
static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
{
struct fib6_info *iter;
struct fib6_node *fn;
fn = rcu_dereference_protected(rt->fib6_node,
lockdep_is_held(&rt->fib6_table->tb6_lock));
iter = rcu_dereference_protected(fn->leaf,
lockdep_is_held(&rt->fib6_table->tb6_lock));
while (iter) {
if (iter->fib6_metric == rt->fib6_metric &&
rt6_qualify_for_ecmp(iter))
return iter;
iter = rcu_dereference_protected(iter->fib6_next,
lockdep_is_held(&rt->fib6_table->tb6_lock));
}
return NULL;
}
/* only called for fib entries with builtin fib6_nh */
static bool rt6_is_dead(const struct fib6_info *rt)
{
if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD ||
(rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN &&
ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev)))
return true;
return false;
}
static int rt6_multipath_total_weight(const struct fib6_info *rt)
{
struct fib6_info *iter;
int total = 0;
if (!rt6_is_dead(rt))
total += rt->fib6_nh->fib_nh_weight;
list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
if (!rt6_is_dead(iter))
total += iter->fib6_nh->fib_nh_weight;
}
return total;
}
static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
{
int upper_bound = -1;
if (!rt6_is_dead(rt)) {
*weight += rt->fib6_nh->fib_nh_weight;
upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
total) - 1;
}
atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
}
static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
{
struct fib6_info *iter;
int weight = 0;
rt6_upper_bound_set(rt, &weight, total);
list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
rt6_upper_bound_set(iter, &weight, total);
}
void rt6_multipath_rebalance(struct fib6_info *rt)
{
struct fib6_info *first;
int total;
/* In case the entire multipath route was marked for flushing,
* then there is no need to rebalance upon the removal of every
* sibling route.
*/
if (!rt->fib6_nsiblings || rt->should_flush)
return;
/* During lookup routes are evaluated in order, so we need to
* make sure upper bounds are assigned from the first sibling
* onwards.
*/
first = rt6_multipath_first_sibling(rt);
if (WARN_ON_ONCE(!first))
return;
total = rt6_multipath_total_weight(first);
rt6_multipath_upper_bound_set(first, total);
}
static int fib6_ifup(struct fib6_info *rt, void *p_arg)
{
const struct arg_netdev_event *arg = p_arg;
struct net *net = dev_net(arg->dev);
if (rt != net->ipv6.fib6_null_entry && !rt->nh &&
rt->fib6_nh->fib_nh_dev == arg->dev) {
rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags;
fib6_update_sernum_upto_root(net, rt);
rt6_multipath_rebalance(rt);
}
return 0;
}
void rt6_sync_up(struct net_device *dev, unsigned char nh_flags)
{
struct arg_netdev_event arg = {
.dev = dev,
{
.nh_flags = nh_flags,
},
};
if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
arg.nh_flags |= RTNH_F_LINKDOWN;
fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
}
/* only called for fib entries with inline fib6_nh */
static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
const struct net_device *dev)
{
struct fib6_info *iter;
if (rt->fib6_nh->fib_nh_dev == dev)
return true;
list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
if (iter->fib6_nh->fib_nh_dev == dev)
return true;
return false;
}
static void rt6_multipath_flush(struct fib6_info *rt)
{
struct fib6_info *iter;
rt->should_flush = 1;
list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
iter->should_flush = 1;
}
static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
const struct net_device *down_dev)
{
struct fib6_info *iter;
unsigned int dead = 0;
if (rt->fib6_nh->fib_nh_dev == down_dev ||
rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
dead++;
list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
if (iter->fib6_nh->fib_nh_dev == down_dev ||
iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
dead++;
return dead;
}
static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
const struct net_device *dev,
unsigned char nh_flags)
{
struct fib6_info *iter;
if (rt->fib6_nh->fib_nh_dev == dev)
rt->fib6_nh->fib_nh_flags |= nh_flags;
list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
if (iter->fib6_nh->fib_nh_dev == dev)
iter->fib6_nh->fib_nh_flags |= nh_flags;
}
/* called with write lock held for table with rt */
static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
{
const struct arg_netdev_event *arg = p_arg;
const struct net_device *dev = arg->dev;
struct net *net = dev_net(dev);
if (rt == net->ipv6.fib6_null_entry || rt->nh)
return 0;
switch (arg->event) {
case NETDEV_UNREGISTER:
return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
case NETDEV_DOWN:
if (rt->should_flush)
return -1;
if (!rt->fib6_nsiblings)
return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
if (rt6_multipath_uses_dev(rt, dev)) {
unsigned int count;
count = rt6_multipath_dead_count(rt, dev);
if (rt->fib6_nsiblings + 1 == count) {
rt6_multipath_flush(rt);
return -1;
}
rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
RTNH_F_LINKDOWN);
fib6_update_sernum(net, rt);
rt6_multipath_rebalance(rt);
}
return -2;
case NETDEV_CHANGE:
if (rt->fib6_nh->fib_nh_dev != dev ||
rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
break;
rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
rt6_multipath_rebalance(rt);
break;
}
return 0;
}
void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
{
struct arg_netdev_event arg = {
.dev = dev,
{
.event = event,
},
};
struct net *net = dev_net(dev);
if (net->ipv6.sysctl.skip_notify_on_dev_down)
fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
else
fib6_clean_all(net, fib6_ifdown, &arg);
}
void rt6_disable_ip(struct net_device *dev, unsigned long event)
{
rt6_sync_down_dev(dev, event);
rt6_uncached_list_flush_dev(dev);
neigh_ifdown(&nd_tbl, dev);
}
struct rt6_mtu_change_arg {
struct net_device *dev;
unsigned int mtu;
struct fib6_info *f6i;
};
static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
{
struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg;
struct fib6_info *f6i = arg->f6i;
/* For administrative MTU increase, there is no way to discover
* IPv6 PMTU increase, so PMTU increase should be updated here.
* Since RFC 1981 doesn't include administrative MTU increase
* update PMTU increase is a MUST. (i.e. jumbo frame)
*/
if (nh->fib_nh_dev == arg->dev) {
struct inet6_dev *idev = __in6_dev_get(arg->dev);
u32 mtu = f6i->fib6_pmtu;
if (mtu >= arg->mtu ||
(mtu < arg->mtu && mtu == idev->cnf.mtu6))
fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
spin_lock_bh(&rt6_exception_lock);
rt6_exceptions_update_pmtu(idev, nh, arg->mtu);
spin_unlock_bh(&rt6_exception_lock);
}
return 0;
}
static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
{
struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
struct inet6_dev *idev;
/* In IPv6 pmtu discovery is not optional,
so that RTAX_MTU lock cannot disable it.
We still use this lock to block changes
caused by addrconf/ndisc.
*/
idev = __in6_dev_get(arg->dev);
if (!idev)
return 0;
if (fib6_metric_locked(f6i, RTAX_MTU))
return 0;
arg->f6i = f6i;
if (f6i->nh) {
/* fib6_nh_mtu_change only returns 0, so this is safe */
return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change,
arg);
}
return fib6_nh_mtu_change(f6i->fib6_nh, arg);
}
void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
{
struct rt6_mtu_change_arg arg = {
.dev = dev,
.mtu = mtu,
};
fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
}
static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
[RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 },
[RTA_GATEWAY] = { .len = sizeof(struct in6_addr) },
[RTA_PREFSRC] = { .len = sizeof(struct in6_addr) },
[RTA_OIF] = { .type = NLA_U32 },
[RTA_IIF] = { .type = NLA_U32 },
[RTA_PRIORITY] = { .type = NLA_U32 },
[RTA_METRICS] = { .type = NLA_NESTED },
[RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) },
[RTA_PREF] = { .type = NLA_U8 },
[RTA_ENCAP_TYPE] = { .type = NLA_U16 },
[RTA_ENCAP] = { .type = NLA_NESTED },
[RTA_EXPIRES] = { .type = NLA_U32 },
[RTA_UID] = { .type = NLA_U32 },
[RTA_MARK] = { .type = NLA_U32 },
[RTA_TABLE] = { .type = NLA_U32 },
[RTA_IP_PROTO] = { .type = NLA_U8 },
[RTA_SPORT] = { .type = NLA_U16 },
[RTA_DPORT] = { .type = NLA_U16 },
[RTA_NH_ID] = { .type = NLA_U32 },
};
static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
struct fib6_config *cfg,
struct netlink_ext_ack *extack)
{
struct rtmsg *rtm;
struct nlattr *tb[RTA_MAX+1];
unsigned int pref;
int err;
err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
rtm_ipv6_policy, extack);
if (err < 0)
goto errout;
err = -EINVAL;
rtm = nlmsg_data(nlh);
if (rtm->rtm_tos) {
NL_SET_ERR_MSG(extack,
"Invalid dsfield (tos): option not available for IPv6");
goto errout;
}
*cfg = (struct fib6_config){
.fc_table = rtm->rtm_table,
.fc_dst_len = rtm->rtm_dst_len,
.fc_src_len = rtm->rtm_src_len,
.fc_flags = RTF_UP,
.fc_protocol = rtm->rtm_protocol,
.fc_type = rtm->rtm_type,
.fc_nlinfo.portid = NETLINK_CB(skb).portid,
.fc_nlinfo.nlh = nlh,
.fc_nlinfo.nl_net = sock_net(skb->sk),
};
if (rtm->rtm_type == RTN_UNREACHABLE ||
rtm->rtm_type == RTN_BLACKHOLE ||
rtm->rtm_type == RTN_PROHIBIT ||
rtm->rtm_type == RTN_THROW)
cfg->fc_flags |= RTF_REJECT;
if (rtm->rtm_type == RTN_LOCAL)
cfg->fc_flags |= RTF_LOCAL;
if (rtm->rtm_flags & RTM_F_CLONED)
cfg->fc_flags |= RTF_CACHE;
cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
if (tb[RTA_NH_ID]) {
if (tb[RTA_GATEWAY] || tb[RTA_OIF] ||
tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {
NL_SET_ERR_MSG(extack,
"Nexthop specification and nexthop id are mutually exclusive");
goto errout;
}
cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);
}
if (tb[RTA_GATEWAY]) {
cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
cfg->fc_flags |= RTF_GATEWAY;
}
if (tb[RTA_VIA]) {
NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
goto errout;
}
if (tb[RTA_DST]) {
int plen = (rtm->rtm_dst_len + 7) >> 3;
if (nla_len(tb[RTA_DST]) < plen)
goto errout;
nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
}
if (tb[RTA_SRC]) {
int plen = (rtm->rtm_src_len + 7) >> 3;
if (nla_len(tb[RTA_SRC]) < plen)
goto errout;
nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
}
if (tb[RTA_PREFSRC])
cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
if (tb[RTA_OIF])
cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
if (tb[RTA_PRIORITY])
cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
if (tb[RTA_METRICS]) {
cfg->fc_mx = nla_data(tb[RTA_METRICS]);
cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
}
if (tb[RTA_TABLE])
cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
if (tb[RTA_MULTIPATH]) {
cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
cfg->fc_mp_len, extack);
if (err < 0)
goto errout;
}
if (tb[RTA_PREF]) {
pref = nla_get_u8(tb[RTA_PREF]);
if (pref != ICMPV6_ROUTER_PREF_LOW &&
pref != ICMPV6_ROUTER_PREF_HIGH)
pref = ICMPV6_ROUTER_PREF_MEDIUM;
cfg->fc_flags |= RTF_PREF(pref);
}
if (tb[RTA_ENCAP])
cfg->fc_encap = tb[RTA_ENCAP];
if (tb[RTA_ENCAP_TYPE]) {
cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
if (err < 0)
goto errout;
}
if (tb[RTA_EXPIRES]) {
unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
if (addrconf_finite_timeout(timeout)) {
cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
cfg->fc_flags |= RTF_EXPIRES;
}
}
err = 0;
errout:
return err;
}
struct rt6_nh {
struct fib6_info *fib6_info;
struct fib6_config r_cfg;
struct list_head next;
};
static int ip6_route_info_append(struct net *net,
struct list_head *rt6_nh_list,
struct fib6_info *rt,
struct fib6_config *r_cfg)
{
struct rt6_nh *nh;
int err = -EEXIST;
list_for_each_entry(nh, rt6_nh_list, next) {
/* check if fib6_info already exists */
if (rt6_duplicate_nexthop(nh->fib6_info, rt))
return err;
}
nh = kzalloc(sizeof(*nh), GFP_KERNEL);
if (!nh)
return -ENOMEM;
nh->fib6_info = rt;
memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
list_add_tail(&nh->next, rt6_nh_list);
return 0;
}
static void ip6_route_mpath_notify(struct fib6_info *rt,
struct fib6_info *rt_last,
struct nl_info *info,
__u16 nlflags)
{
/* if this is an APPEND route, then rt points to the first route
* inserted and rt_last points to last route inserted. Userspace
* wants a consistent dump of the route which starts at the first
* nexthop. Since sibling routes are always added at the end of
* the list, find the first sibling of the last route appended
*/
if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
rt = list_first_entry(&rt_last->fib6_siblings,
struct fib6_info,
fib6_siblings);
}
if (rt)
inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
}
static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
{
bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
bool should_notify = false;
struct fib6_info *leaf;
struct fib6_node *fn;
rcu_read_lock();
fn = rcu_dereference(rt->fib6_node);
if (!fn)
goto out;
leaf = rcu_dereference(fn->leaf);
if (!leaf)
goto out;
if (rt == leaf ||
(rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric &&
rt6_qualify_for_ecmp(leaf)))
should_notify = true;
out:
rcu_read_unlock();
return should_notify;
}
static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla,
struct netlink_ext_ack *extack)
{
if (nla_len(nla) < sizeof(*gw)) {
NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY");
return -EINVAL;
}
*gw = nla_get_in6_addr(nla);
return 0;
}
static int ip6_route_multipath_add(struct fib6_config *cfg,
struct netlink_ext_ack *extack)
{
struct fib6_info *rt_notif = NULL, *rt_last = NULL;
struct nl_info *info = &cfg->fc_nlinfo;
struct fib6_config r_cfg;
struct rtnexthop *rtnh;
struct fib6_info *rt;
struct rt6_nh *err_nh;
struct rt6_nh *nh, *nh_safe;
__u16 nlflags;
int remaining;
int attrlen;
int err = 1;
int nhn = 0;
int replace = (cfg->fc_nlinfo.nlh &&
(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
LIST_HEAD(rt6_nh_list);
nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
nlflags |= NLM_F_APPEND;
remaining = cfg->fc_mp_len;
rtnh = (struct rtnexthop *)cfg->fc_mp;
/* Parse a Multipath Entry and build a list (rt6_nh_list) of
* fib6_info structs per nexthop
*/
while (rtnh_ok(rtnh, remaining)) {
memcpy(&r_cfg, cfg, sizeof(*cfg));
if (rtnh->rtnh_ifindex)
r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
attrlen = rtnh_attrlen(rtnh);
if (attrlen > 0) {
struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
nla = nla_find(attrs, attrlen, RTA_GATEWAY);
if (nla) {
err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
extack);
if (err)
goto cleanup;
r_cfg.fc_flags |= RTF_GATEWAY;
}
r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
/* RTA_ENCAP_TYPE length checked in
* lwtunnel_valid_encap_type_attr
*/
nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
if (nla)
r_cfg.fc_encap_type = nla_get_u16(nla);
}
r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
if (IS_ERR(rt)) {
err = PTR_ERR(rt);
rt = NULL;
goto cleanup;
}
if (!rt6_qualify_for_ecmp(rt)) {
err = -EINVAL;
NL_SET_ERR_MSG(extack,
"Device only routes can not be added for IPv6 using the multipath API.");
fib6_info_release(rt);
goto cleanup;
}
rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
rt, &r_cfg);
if (err) {
fib6_info_release(rt);
goto cleanup;
}
rtnh = rtnh_next(rtnh, &remaining);
}
if (list_empty(&rt6_nh_list)) {
NL_SET_ERR_MSG(extack,
"Invalid nexthop configuration - no valid nexthops");
return -EINVAL;
}
/* for add and replace send one notification with all nexthops.
* Skip the notification in fib6_add_rt2node and send one with
* the full route when done
*/
info->skip_notify = 1;
/* For add and replace, send one notification with all nexthops. For
* append, send one notification with all appended nexthops.
*/
info->skip_notify_kernel = 1;
err_nh = NULL;
list_for_each_entry(nh, &rt6_nh_list, next) {
err = __ip6_ins_rt(nh->fib6_info, info, extack);
if (err) {
if (replace && nhn)
NL_SET_ERR_MSG_MOD(extack,
"multipath route replace failed (check consistency of installed routes)");
err_nh = nh;
goto add_errout;
}
/* save reference to last route successfully inserted */
rt_last = nh->fib6_info;
/* save reference to first route for notification */
if (!rt_notif)
rt_notif = nh->fib6_info;
/* Because each route is added like a single route we remove
* these flags after the first nexthop: if there is a collision,
* we have already failed to add the first nexthop:
* fib6_add_rt2node() has rejected it; when replacing, old
* nexthops have been replaced by first new, the rest should
* be added to it.
*/
if (cfg->fc_nlinfo.nlh) {
cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
NLM_F_REPLACE);
cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
}
nhn++;
}
/* An in-kernel notification should only be sent in case the new
* multipath route is added as the first route in the node, or if
* it was appended to it. We pass 'rt_notif' since it is the first
* sibling and might allow us to skip some checks in the replace case.
*/
if (ip6_route_mpath_should_notify(rt_notif)) {
enum fib_event_type fib_event;
if (rt_notif->fib6_nsiblings != nhn - 1)
fib_event = FIB_EVENT_ENTRY_APPEND;
else
fib_event = FIB_EVENT_ENTRY_REPLACE;
err = call_fib6_multipath_entry_notifiers(info->nl_net,
fib_event, rt_notif,
nhn - 1, extack);
if (err) {
/* Delete all the siblings that were just added */
err_nh = NULL;
goto add_errout;
}
}
/* success ... tell user about new route */
ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
goto cleanup;
add_errout:
/* send notification for routes that were added so that
* the delete notifications sent by ip6_route_del are
* coherent
*/
if (rt_notif)
ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
/* Delete routes that were already added */
list_for_each_entry(nh, &rt6_nh_list, next) {
if (err_nh == nh)
break;
ip6_route_del(&nh->r_cfg, extack);
}
cleanup:
list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
fib6_info_release(nh->fib6_info);
list_del(&nh->next);
kfree(nh);
}
return err;
}
static int ip6_route_multipath_del(struct fib6_config *cfg,
struct netlink_ext_ack *extack)
{
struct fib6_config r_cfg;
struct rtnexthop *rtnh;
int last_err = 0;
int remaining;
int attrlen;
int err;
remaining = cfg->fc_mp_len;
rtnh = (struct rtnexthop *)cfg->fc_mp;
/* Parse a Multipath Entry */
while (rtnh_ok(rtnh, remaining)) {
memcpy(&r_cfg, cfg, sizeof(*cfg));
if (rtnh->rtnh_ifindex)
r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
attrlen = rtnh_attrlen(rtnh);
if (attrlen > 0) {
struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
nla = nla_find(attrs, attrlen, RTA_GATEWAY);
if (nla) {
err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
extack);
if (err) {
last_err = err;
goto next_rtnh;
}
r_cfg.fc_flags |= RTF_GATEWAY;
}
}
err = ip6_route_del(&r_cfg, extack);
if (err)
last_err = err;
next_rtnh:
rtnh = rtnh_next(rtnh, &remaining);
}
return last_err;
}
static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct fib6_config cfg;
int err;
err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
if (err < 0)
return err;
if (cfg.fc_nh_id &&
!nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {
NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
return -EINVAL;
}
if (cfg.fc_mp)
return ip6_route_multipath_del(&cfg, extack);
else {
cfg.fc_delete_all_nh = 1;
return ip6_route_del(&cfg, extack);
}
}
static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct fib6_config cfg;
int err;
err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
if (err < 0)
return err;
if (cfg.fc_metric == 0)
cfg.fc_metric = IP6_RT_PRIO_USER;
if (cfg.fc_mp)
return ip6_route_multipath_add(&cfg, extack);
else
return ip6_route_add(&cfg, GFP_KERNEL, extack);
}
/* add the overhead of this fib6_nh to nexthop_len */
static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg)
{
int *nexthop_len = arg;
*nexthop_len += nla_total_size(0) /* RTA_MULTIPATH */
+ NLA_ALIGN(sizeof(struct rtnexthop))
+ nla_total_size(16); /* RTA_GATEWAY */
if (nh->fib_nh_lws) {
/* RTA_ENCAP_TYPE */
*nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
/* RTA_ENCAP */
*nexthop_len += nla_total_size(2);
}
return 0;
}
static size_t rt6_nlmsg_size(struct fib6_info *f6i)
{
int nexthop_len;
if (f6i->nh) {
nexthop_len = nla_total_size(4); /* RTA_NH_ID */
nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
&nexthop_len);
} else {
struct fib6_info *sibling, *next_sibling;
struct fib6_nh *nh = f6i->fib6_nh;
nexthop_len = 0;
if (f6i->fib6_nsiblings) {
rt6_nh_nlmsg_size(nh, &nexthop_len);
list_for_each_entry_safe(sibling, next_sibling,
&f6i->fib6_siblings, fib6_siblings) {
rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len);
}
}
nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
}
return NLMSG_ALIGN(sizeof(struct rtmsg))
+ nla_total_size(16) /* RTA_SRC */
+ nla_total_size(16) /* RTA_DST */
+ nla_total_size(16) /* RTA_GATEWAY */
+ nla_total_size(16) /* RTA_PREFSRC */
+ nla_total_size(4) /* RTA_TABLE */
+ nla_total_size(4) /* RTA_IIF */
+ nla_total_size(4) /* RTA_OIF */
+ nla_total_size(4) /* RTA_PRIORITY */
+ RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
+ nla_total_size(sizeof(struct rta_cacheinfo))
+ nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
+ nla_total_size(1) /* RTA_PREF */
+ nexthop_len;
}
static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh,
unsigned char *flags)
{
if (nexthop_is_multipath(nh)) {
struct nlattr *mp;
mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
if (!mp)
goto nla_put_failure;
if (nexthop_mpath_fill_node(skb, nh, AF_INET6))
goto nla_put_failure;
nla_nest_end(skb, mp);
} else {
struct fib6_nh *fib6_nh;
fib6_nh = nexthop_fib6_nh(nh);
if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,
flags, false) < 0)
goto nla_put_failure;
}
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static int rt6_fill_node(struct net *net, struct sk_buff *skb,
struct fib6_info *rt, struct dst_entry *dst,
struct in6_addr *dest, struct in6_addr *src,
int iif, int type, u32 portid, u32 seq,
unsigned int flags)
{
struct rt6_info *rt6 = dst_rt6_info(dst);
struct rt6key *rt6_dst, *rt6_src;
u32 *pmetrics, table, rt6_flags;
unsigned char nh_flags = 0;
struct nlmsghdr *nlh;
struct rtmsg *rtm;
long expires = 0;
nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
if (!nlh)
return -EMSGSIZE;
if (rt6) {
rt6_dst = &rt6->rt6i_dst;
rt6_src = &rt6->rt6i_src;
rt6_flags = rt6->rt6i_flags;
} else {
rt6_dst = &rt->fib6_dst;
rt6_src = &rt->fib6_src;
rt6_flags = rt->fib6_flags;
}
rtm = nlmsg_data(nlh);
rtm->rtm_family = AF_INET6;
rtm->rtm_dst_len = rt6_dst->plen;
rtm->rtm_src_len = rt6_src->plen;
rtm->rtm_tos = 0;
if (rt->fib6_table)
table = rt->fib6_table->tb6_id;
else
table = RT6_TABLE_UNSPEC;
rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
if (nla_put_u32(skb, RTA_TABLE, table))
goto nla_put_failure;
rtm->rtm_type = rt->fib6_type;
rtm->rtm_flags = 0;
rtm->rtm_scope = RT_SCOPE_UNIVERSE;
rtm->rtm_protocol = rt->fib6_protocol;
if (rt6_flags & RTF_CACHE)
rtm->rtm_flags |= RTM_F_CLONED;
if (dest) {
if (nla_put_in6_addr(skb, RTA_DST, dest))
goto nla_put_failure;
rtm->rtm_dst_len = 128;
} else if (rtm->rtm_dst_len)
if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
goto nla_put_failure;
#ifdef CONFIG_IPV6_SUBTREES
if (src) {
if (nla_put_in6_addr(skb, RTA_SRC, src))
goto nla_put_failure;
rtm->rtm_src_len = 128;
} else if (rtm->rtm_src_len &&
nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
goto nla_put_failure;
#endif
if (iif) {
#ifdef CONFIG_IPV6_MROUTE
if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
int err = ip6mr_get_route(net, skb, rtm, portid);
if (err == 0)
return 0;
if (err < 0)
goto nla_put_failure;
} else
#endif
if (nla_put_u32(skb, RTA_IIF, iif))
goto nla_put_failure;
} else if (dest) {
struct in6_addr saddr_buf;
if (ip6_route_get_saddr(net, rt, dest, 0, 0, &saddr_buf) == 0 &&
nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
goto nla_put_failure;
}
if (rt->fib6_prefsrc.plen) {
struct in6_addr saddr_buf;
saddr_buf = rt->fib6_prefsrc.addr;
if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
goto nla_put_failure;
}
pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
if (rtnetlink_put_metrics(skb, pmetrics) < 0)
goto nla_put_failure;
if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
goto nla_put_failure;
/* For multipath routes, walk the siblings list and add
* each as a nexthop within RTA_MULTIPATH.
*/
if (rt6) {
if (rt6_flags & RTF_GATEWAY &&
nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
goto nla_put_failure;
if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
goto nla_put_failure;
if (dst->lwtstate &&
lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
goto nla_put_failure;
} else if (rt->fib6_nsiblings) {
struct fib6_info *sibling, *next_sibling;
struct nlattr *mp;
mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
if (!mp)
goto nla_put_failure;
if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
rt->fib6_nh->fib_nh_weight, AF_INET6,
0) < 0)
goto nla_put_failure;
list_for_each_entry_safe(sibling, next_sibling,
&rt->fib6_siblings, fib6_siblings) {
if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
sibling->fib6_nh->fib_nh_weight,
AF_INET6, 0) < 0)
goto nla_put_failure;
}
nla_nest_end(skb, mp);
} else if (rt->nh) {
if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
goto nla_put_failure;
if (nexthop_is_blackhole(rt->nh))
rtm->rtm_type = RTN_BLACKHOLE;
if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) &&
rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0)
goto nla_put_failure;
rtm->rtm_flags |= nh_flags;
} else {
if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,
&nh_flags, false) < 0)
goto nla_put_failure;
rtm->rtm_flags |= nh_flags;
}
if (rt6_flags & RTF_EXPIRES) {
expires = dst ? dst->expires : rt->expires;
expires -= jiffies;
}
if (!dst) {
if (READ_ONCE(rt->offload))
rtm->rtm_flags |= RTM_F_OFFLOAD;
if (READ_ONCE(rt->trap))
rtm->rtm_flags |= RTM_F_TRAP;
if (READ_ONCE(rt->offload_failed))
rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED;
}
if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
goto nla_put_failure;
if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
goto nla_put_failure;
nlmsg_end(skb, nlh);
return 0;
nla_put_failure:
nlmsg_cancel(skb, nlh);
return -EMSGSIZE;
}
static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg)
{
const struct net_device *dev = arg;
if (nh->fib_nh_dev == dev)
return 1;
return 0;
}
static bool fib6_info_uses_dev(const struct fib6_info *f6i,
const struct net_device *dev)
{
if (f6i->nh) {
struct net_device *_dev = (struct net_device *)dev;
return !!nexthop_for_each_fib6_nh(f6i->nh,
fib6_info_nh_uses_dev,
_dev);
}
if (f6i->fib6_nh->fib_nh_dev == dev)
return true;
if (f6i->fib6_nsiblings) {
struct fib6_info *sibling, *next_sibling;
list_for_each_entry_safe(sibling, next_sibling,
&f6i->fib6_siblings, fib6_siblings) {
if (sibling->fib6_nh->fib_nh_dev == dev)
return true;
}
}
return false;
}
struct fib6_nh_exception_dump_walker {
struct rt6_rtnl_dump_arg *dump;
struct fib6_info *rt;
unsigned int flags;
unsigned int skip;
unsigned int count;
};
static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg)
{
struct fib6_nh_exception_dump_walker *w = arg;
struct rt6_rtnl_dump_arg *dump = w->dump;
struct rt6_exception_bucket *bucket;
struct rt6_exception *rt6_ex;
int i, err;
bucket = fib6_nh_get_excptn_bucket(nh, NULL);
if (!bucket)
return 0;
for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
if (w->skip) {
w->skip--;
continue;
}
/* Expiration of entries doesn't bump sernum, insertion
* does. Removal is triggered by insertion, so we can
* rely on the fact that if entries change between two
* partial dumps, this node is scanned again completely,
* see rt6_insert_exception() and fib6_dump_table().
*
* Count expired entries we go through as handled
* entries that we'll skip next time, in case of partial
* node dump. Otherwise, if entries expire meanwhile,
* we'll skip the wrong amount.
*/
if (rt6_check_expired(rt6_ex->rt6i)) {
w->count++;
continue;
}
err = rt6_fill_node(dump->net, dump->skb, w->rt,
&rt6_ex->rt6i->dst, NULL, NULL, 0,
RTM_NEWROUTE,
NETLINK_CB(dump->cb->skb).portid,
dump->cb->nlh->nlmsg_seq, w->flags);
if (err)
return err;
w->count++;
}
bucket++;
}
return 0;
}
/* Return -1 if done with node, number of handled routes on partial dump */
int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip)
{
struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
struct fib_dump_filter *filter = &arg->filter;
unsigned int flags = NLM_F_MULTI;
struct net *net = arg->net;
int count = 0;
if (rt == net->ipv6.fib6_null_entry)
return -1;
if ((filter->flags & RTM_F_PREFIX) &&
!(rt->fib6_flags & RTF_PREFIX_RT)) {
/* success since this is not a prefix route */
return -1;
}
if (filter->filter_set &&
((filter->rt_type && rt->fib6_type != filter->rt_type) ||
(filter->dev && !fib6_info_uses_dev(rt, filter->dev)) ||
(filter->protocol && rt->fib6_protocol != filter->protocol))) {
return -1;
}
if (filter->filter_set ||
!filter->dump_routes || !filter->dump_exceptions) {
flags |= NLM_F_DUMP_FILTERED;
}
if (filter->dump_routes) {
if (skip) {
skip--;
} else {
if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL,
0, RTM_NEWROUTE,
NETLINK_CB(arg->cb->skb).portid,
arg->cb->nlh->nlmsg_seq, flags)) {
return 0;
}
count++;
}
}
if (filter->dump_exceptions) {
struct fib6_nh_exception_dump_walker w = { .dump = arg,
.rt = rt,
.flags = flags,
.skip = skip,
.count = 0 };
int err;
rcu_read_lock();
if (rt->nh) {
err = nexthop_for_each_fib6_nh(rt->nh,
rt6_nh_dump_exceptions,
&w);
} else {
err = rt6_nh_dump_exceptions(rt->fib6_nh, &w);
}
rcu_read_unlock();
if (err)
return count + w.count;
}
return -1;
}
static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
const struct nlmsghdr *nlh,
struct nlattr **tb,
struct netlink_ext_ack *extack)
{
struct rtmsg *rtm;
int i, err;
if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
NL_SET_ERR_MSG_MOD(extack,
"Invalid header for get route request");
return -EINVAL;
}
if (!netlink_strict_get_check(skb))
return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
rtm_ipv6_policy, extack);
rtm = nlmsg_data(nlh);
if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
(rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
rtm->rtm_type) {
NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
return -EINVAL;
}
if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
NL_SET_ERR_MSG_MOD(extack,
"Invalid flags for get route request");
return -EINVAL;
}
err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
rtm_ipv6_policy, extack);
if (err)
return err;
if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
(tb[RTA_DST] && !rtm->rtm_dst_len)) {
NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
return -EINVAL;
}
for (i = 0; i <= RTA_MAX; i++) {
if (!tb[i])
continue;
switch (i) {
case RTA_SRC:
case RTA_DST:
case RTA_IIF:
case RTA_OIF:
case RTA_MARK:
case RTA_UID:
case RTA_SPORT:
case RTA_DPORT:
case RTA_IP_PROTO:
break;
default:
NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
return -EINVAL;
}
}
return 0;
}
static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
struct net *net = sock_net(in_skb->sk);
struct nlattr *tb[RTA_MAX+1];
int err, iif = 0, oif = 0;
struct fib6_info *from;
struct dst_entry *dst;
struct rt6_info *rt;
struct sk_buff *skb;
struct rtmsg *rtm;
struct flowi6 fl6 = {};
bool fibmatch;
err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
if (err < 0)
goto errout;
err = -EINVAL;
rtm = nlmsg_data(nlh);
fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
if (tb[RTA_SRC]) {
if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
goto errout;
fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
}
if (tb[RTA_DST]) {
if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
goto errout;
fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
}
if (tb[RTA_IIF])
iif = nla_get_u32(tb[RTA_IIF]);
if (tb[RTA_OIF])
oif = nla_get_u32(tb[RTA_OIF]);
if (tb[RTA_MARK])
fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
if (tb[RTA_UID])
fl6.flowi6_uid = make_kuid(current_user_ns(),
nla_get_u32(tb[RTA_UID]));
else
fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
if (tb[RTA_SPORT])
fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
if (tb[RTA_DPORT])
fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
if (tb[RTA_IP_PROTO]) {
err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
&fl6.flowi6_proto, AF_INET6,
extack);
if (err)
goto errout;
}
if (iif) {
struct net_device *dev;
int flags = 0;
rcu_read_lock();
dev = dev_get_by_index_rcu(net, iif);
if (!dev) {
rcu_read_unlock();
err = -ENODEV;
goto errout;
}
fl6.flowi6_iif = iif;
if (!ipv6_addr_any(&fl6.saddr))
flags |= RT6_LOOKUP_F_HAS_SADDR;
dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
rcu_read_unlock();
} else {
fl6.flowi6_oif = oif;
dst = ip6_route_output(net, NULL, &fl6);
}
rt = dst_rt6_info(dst);
if (rt->dst.error) {
err = rt->dst.error;
ip6_rt_put(rt);
goto errout;
}
if (rt == net->ipv6.ip6_null_entry) {
err = rt->dst.error;
ip6_rt_put(rt);
goto errout;
}
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
if (!skb) {
ip6_rt_put(rt);
err = -ENOBUFS;
goto errout;
}
skb_dst_set(skb, &rt->dst);
rcu_read_lock();
from = rcu_dereference(rt->from);
if (from) {
if (fibmatch)
err = rt6_fill_node(net, skb, from, NULL, NULL, NULL,
iif, RTM_NEWROUTE,
NETLINK_CB(in_skb).portid,
nlh->nlmsg_seq, 0);
else
err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
&fl6.saddr, iif, RTM_NEWROUTE,
NETLINK_CB(in_skb).portid,
nlh->nlmsg_seq, 0);
} else {
err = -ENETUNREACH;
}
rcu_read_unlock();
if (err < 0) {
kfree_skb(skb);
goto errout;
}
err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
errout:
return err;
}
void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
unsigned int nlm_flags)
{
struct sk_buff *skb;
struct net *net = info->nl_net;
u32 seq;
int err;
err = -ENOBUFS;
seq = info->nlh ? info->nlh->nlmsg_seq : 0;
skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
if (!skb)
goto errout;
err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
event, info->portid, seq, nlm_flags);
if (err < 0) {
/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
WARN_ON(err == -EMSGSIZE);
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
info->nlh, gfp_any());
return;
errout:
rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
}
void fib6_rt_update(struct net *net, struct fib6_info *rt,
struct nl_info *info)
{
u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
struct sk_buff *skb;
int err = -ENOBUFS;
skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
if (!skb)
goto errout;
err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
if (err < 0) {
/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
WARN_ON(err == -EMSGSIZE);
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
info->nlh, gfp_any());
return;
errout:
rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
}
void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
bool offload, bool trap, bool offload_failed)
{
struct sk_buff *skb;
int err;
if (READ_ONCE(f6i->offload) == offload &&
READ_ONCE(f6i->trap) == trap &&
READ_ONCE(f6i->offload_failed) == offload_failed)
return;
WRITE_ONCE(f6i->offload, offload);
WRITE_ONCE(f6i->trap, trap);
/* 2 means send notifications only if offload_failed was changed. */
if (net->ipv6.sysctl.fib_notify_on_flag_change == 2 &&
READ_ONCE(f6i->offload_failed) == offload_failed)
return;
WRITE_ONCE(f6i->offload_failed, offload_failed);
if (!rcu_access_pointer(f6i->fib6_node))
/* The route was removed from the tree, do not send
* notification.
*/
return;
if (!net->ipv6.sysctl.fib_notify_on_flag_change)
return;
skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL);
if (!skb) {
err = -ENOBUFS;
goto errout;
}
err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0,
0, 0);
if (err < 0) {
/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
WARN_ON(err == -EMSGSIZE);
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL);
return;
errout:
rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
}
EXPORT_SYMBOL(fib6_info_hw_flags_set);
static int ip6_route_dev_notify(struct notifier_block *this,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct net *net = dev_net(dev);
if (!(dev->flags & IFF_LOOPBACK))
return NOTIFY_OK;
if (event == NETDEV_REGISTER) {
net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev;
net->ipv6.ip6_null_entry->dst.dev = dev;
net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
net->ipv6.ip6_prohibit_entry->dst.dev = dev;
net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
#endif
} else if (event == NETDEV_UNREGISTER &&
dev->reg_state != NETREG_UNREGISTERED) {
/* NETDEV_UNREGISTER could be fired for multiple times by
* netdev_wait_allrefs(). Make sure we only call this once.
*/
in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
#endif
}
return NOTIFY_OK;
}
/*
* /proc
*/
#ifdef CONFIG_PROC_FS
static int rt6_stats_seq_show(struct seq_file *seq, void *v)
{
struct net *net = (struct net *)seq->private;
seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
net->ipv6.rt6_stats->fib_nodes,
net->ipv6.rt6_stats->fib_route_nodes,
atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
net->ipv6.rt6_stats->fib_rt_entries,
net->ipv6.rt6_stats->fib_rt_cache,
dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
net->ipv6.rt6_stats->fib_discarded_routes);
return 0;
}
#endif /* CONFIG_PROC_FS */
#ifdef CONFIG_SYSCTL
static int ipv6_sysctl_rtcache_flush(const struct ctl_table *ctl, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct net *net;
int delay;
int ret;
if (!write)
return -EINVAL;
ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
if (ret)
return ret;
net = (struct net *)ctl->extra1;
delay = net->ipv6.sysctl.flush_delay;
fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
return 0;
}
static struct ctl_table ipv6_route_table_template[] = {
{
.procname = "max_size",
.data = &init_net.ipv6.sysctl.ip6_rt_max_size,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "gc_thresh",
.data = &ip6_dst_ops_template.gc_thresh,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "flush",
.data = &init_net.ipv6.sysctl.flush_delay,
.maxlen = sizeof(int),
.mode = 0200,
.proc_handler = ipv6_sysctl_rtcache_flush
},
{
.procname = "gc_min_interval",
.data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "gc_timeout",
.data = &init_net.ipv6.sysctl.ip6_rt_gc_timeout,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "gc_interval",
.data = &init_net.ipv6.sysctl.ip6_rt_gc_interval,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "gc_elasticity",
.data = &init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "mtu_expires",
.data = &init_net.ipv6.sysctl.ip6_rt_mtu_expires,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
{
.procname = "min_adv_mss",
.data = &init_net.ipv6.sysctl.ip6_rt_min_advmss,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
.procname = "gc_min_interval_ms",
.data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_ms_jiffies,
},
{
.procname = "skip_notify_on_dev_down",
.data = &init_net.ipv6.sysctl.skip_notify_on_dev_down,
.maxlen = sizeof(u8),
.mode = 0644,
.proc_handler = proc_dou8vec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
};
struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
{
struct ctl_table *table;
table = kmemdup(ipv6_route_table_template,
sizeof(ipv6_route_table_template),
GFP_KERNEL);
if (table) {
table[0].data = &net->ipv6.sysctl.ip6_rt_max_size;
table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
table[2].data = &net->ipv6.sysctl.flush_delay;
table[2].extra1 = net;
table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
}
return table;
}
size_t ipv6_route_sysctl_table_size(struct net *net)
{
/* Don't export sysctls to unprivileged users */
if (net->user_ns != &init_user_ns)
return 1;
return ARRAY_SIZE(ipv6_route_table_template);
}
#endif
static int __net_init ip6_route_net_init(struct net *net)
{
int ret = -ENOMEM;
memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
sizeof(net->ipv6.ip6_dst_ops));
if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
goto out_ip6_dst_ops;
net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true);
if (!net->ipv6.fib6_null_entry)
goto out_ip6_dst_entries;
memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template,
sizeof(*net->ipv6.fib6_null_entry));
net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
sizeof(*net->ipv6.ip6_null_entry),
GFP_KERNEL);
if (!net->ipv6.ip6_null_entry)
goto out_fib6_null_entry;
net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
ip6_template_metrics, true);
INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->dst.rt_uncached);
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
net->ipv6.fib6_has_custom_rules = false;
net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
sizeof(*net->ipv6.ip6_prohibit_entry),
GFP_KERNEL);
if (!net->ipv6.ip6_prohibit_entry)
goto out_ip6_null_entry;
net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
ip6_template_metrics, true);
INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->dst.rt_uncached);
net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
sizeof(*net->ipv6.ip6_blk_hole_entry),
GFP_KERNEL);
if (!net->ipv6.ip6_blk_hole_entry)
goto out_ip6_prohibit_entry;
net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
ip6_template_metrics, true);
INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->dst.rt_uncached);
#ifdef CONFIG_IPV6_SUBTREES
net->ipv6.fib6_routes_require_src = 0;
#endif
#endif
net->ipv6.sysctl.flush_delay = 0;
net->ipv6.sysctl.ip6_rt_max_size = INT_MAX;
net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
net->ipv6.sysctl.skip_notify_on_dev_down = 0;
atomic_set(&net->ipv6.ip6_rt_gc_expire, 30*HZ);
ret = 0;
out:
return ret;
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
out_ip6_prohibit_entry:
kfree(net->ipv6.ip6_prohibit_entry);
out_ip6_null_entry:
kfree(net->ipv6.ip6_null_entry);
#endif
out_fib6_null_entry:
kfree(net->ipv6.fib6_null_entry);
out_ip6_dst_entries:
dst_entries_destroy(&net->ipv6.ip6_dst_ops);
out_ip6_dst_ops:
goto out;
}
static void __net_exit ip6_route_net_exit(struct net *net)
{
kfree(net->ipv6.fib6_null_entry);
kfree(net->ipv6.ip6_null_entry);
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
kfree(net->ipv6.ip6_prohibit_entry);
kfree(net->ipv6.ip6_blk_hole_entry);
#endif
dst_entries_destroy(&net->ipv6.ip6_dst_ops);
}
static int __net_init ip6_route_net_init_late(struct net *net)
{
#ifdef CONFIG_PROC_FS
if (!proc_create_net("ipv6_route", 0, net->proc_net,
&ipv6_route_seq_ops,
sizeof(struct ipv6_route_iter)))
return -ENOMEM;
if (!proc_create_net_single("rt6_stats", 0444, net->proc_net,
rt6_stats_seq_show, NULL)) {
remove_proc_entry("ipv6_route", net->proc_net);
return -ENOMEM;
}
#endif
return 0;
}
static void __net_exit ip6_route_net_exit_late(struct net *net)
{
#ifdef CONFIG_PROC_FS
remove_proc_entry("ipv6_route", net->proc_net);
remove_proc_entry("rt6_stats", net->proc_net);
#endif
}
static struct pernet_operations ip6_route_net_ops = {
.init = ip6_route_net_init,
.exit = ip6_route_net_exit,
};
static int __net_init ipv6_inetpeer_init(struct net *net)
{
struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
if (!bp)
return -ENOMEM;
inet_peer_base_init(bp);
net->ipv6.peers = bp;
return 0;
}
static void __net_exit ipv6_inetpeer_exit(struct net *net)
{
struct inet_peer_base *bp = net->ipv6.peers;
net->ipv6.peers = NULL;
inetpeer_invalidate_tree(bp);
kfree(bp);
}
static struct pernet_operations ipv6_inetpeer_ops = {
.init = ipv6_inetpeer_init,
.exit = ipv6_inetpeer_exit,
};
static struct pernet_operations ip6_route_net_late_ops = {
.init = ip6_route_net_init_late,
.exit = ip6_route_net_exit_late,
};
static struct notifier_block ip6_route_dev_notifier = {
.notifier_call = ip6_route_dev_notify,
.priority = ADDRCONF_NOTIFY_PRIORITY - 10,
};
void __init ip6_route_init_special_entries(void)
{
/* Registering of the loopback is done before this portion of code,
* the loopback reference in rt6_info will not be taken, do it
* manually for init_net */
init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev;
init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
#endif
}
#if IS_BUILTIN(CONFIG_IPV6)
#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt)
BTF_ID_LIST(btf_fib6_info_id)
BTF_ID(struct, fib6_info)
static const struct bpf_iter_seq_info ipv6_route_seq_info = {
.seq_ops = &ipv6_route_seq_ops,
.init_seq_private = bpf_iter_init_seq_net,
.fini_seq_private = bpf_iter_fini_seq_net,
.seq_priv_size = sizeof(struct ipv6_route_iter),
};
static struct bpf_iter_reg ipv6_route_reg_info = {
.target = "ipv6_route",
.ctx_arg_info_size = 1,
.ctx_arg_info = {
{ offsetof(struct bpf_iter__ipv6_route, rt),
PTR_TO_BTF_ID_OR_NULL },
},
.seq_info = &ipv6_route_seq_info,
};
static int __init bpf_iter_register(void)
{
ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id;
return bpf_iter_reg_target(&ipv6_route_reg_info);
}
static void bpf_iter_unregister(void)
{
bpf_iter_unreg_target(&ipv6_route_reg_info);
}
#endif
#endif
int __init ip6_route_init(void)
{
int ret;
int cpu;
ret = -ENOMEM;
ip6_dst_ops_template.kmem_cachep =
kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
if (!ip6_dst_ops_template.kmem_cachep)
goto out;
ret = dst_entries_init(&ip6_dst_blackhole_ops);
if (ret)
goto out_kmem_cache;
ret = register_pernet_subsys(&ipv6_inetpeer_ops);
if (ret)
goto out_dst_entries;
ret = register_pernet_subsys(&ip6_route_net_ops);
if (ret)
goto out_register_inetpeer;
ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
ret = fib6_init();
if (ret)
goto out_register_subsys;
ret = xfrm6_init();
if (ret)
goto out_fib6_init;
ret = fib6_rules_init();
if (ret)
goto xfrm6_init;
ret = register_pernet_subsys(&ip6_route_net_late_ops);
if (ret)
goto fib6_rules_init;
ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
inet6_rtm_newroute, NULL, 0);
if (ret < 0)
goto out_register_late_subsys;
ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
inet6_rtm_delroute, NULL, 0);
if (ret < 0)
goto out_register_late_subsys;
ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
inet6_rtm_getroute, NULL,
RTNL_FLAG_DOIT_UNLOCKED);
if (ret < 0)
goto out_register_late_subsys;
ret = register_netdevice_notifier(&ip6_route_dev_notifier);
if (ret)
goto out_register_late_subsys;
#if IS_BUILTIN(CONFIG_IPV6)
#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
ret = bpf_iter_register();
if (ret)
goto out_register_late_subsys;
#endif
#endif
for_each_possible_cpu(cpu) {
struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
INIT_LIST_HEAD(&ul->head);
spin_lock_init(&ul->lock);
}
out:
return ret;
out_register_late_subsys:
rtnl_unregister_all(PF_INET6);
unregister_pernet_subsys(&ip6_route_net_late_ops);
fib6_rules_init:
fib6_rules_cleanup();
xfrm6_init:
xfrm6_fini();
out_fib6_init:
fib6_gc_cleanup();
out_register_subsys:
unregister_pernet_subsys(&ip6_route_net_ops);
out_register_inetpeer:
unregister_pernet_subsys(&ipv6_inetpeer_ops);
out_dst_entries:
dst_entries_destroy(&ip6_dst_blackhole_ops);
out_kmem_cache:
kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
goto out;
}
void ip6_route_cleanup(void)
{
#if IS_BUILTIN(CONFIG_IPV6)
#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
bpf_iter_unregister();
#endif
#endif
unregister_netdevice_notifier(&ip6_route_dev_notifier);
unregister_pernet_subsys(&ip6_route_net_late_ops);
fib6_rules_cleanup();
xfrm6_fini();
fib6_gc_cleanup();
unregister_pernet_subsys(&ipv6_inetpeer_ops);
unregister_pernet_subsys(&ip6_route_net_ops);
dst_entries_destroy(&ip6_dst_blackhole_ops);
kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
}
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