// SPDX-License-Identifier: GPL-2.0
#include <linux/errno.h>
#include <linux/ip.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/types.h>
#include <net/checksum.h>
#include <net/dst_cache.h>
#include <net/ip.h>
#include <net/ip6_fib.h>
#include <net/ip6_route.h>
#include <net/lwtunnel.h>
#include <net/protocol.h>
#include <uapi/linux/ila.h>
#include "ila.h"
struct ila_lwt {
struct ila_params p;
struct dst_cache dst_cache;
u32 connected : 1;
u32 lwt_output : 1;
};
static inline struct ila_lwt *ila_lwt_lwtunnel(
struct lwtunnel_state *lwt)
{
return (struct ila_lwt *)lwt->data;
}
static inline struct ila_params *ila_params_lwtunnel(
struct lwtunnel_state *lwt)
{
return &ila_lwt_lwtunnel(lwt)->p;
}
static int ila_output(struct net *net, struct sock *sk, struct sk_buff *skb)
{
struct dst_entry *orig_dst = skb_dst(skb);
struct rt6_info *rt = dst_rt6_info(orig_dst);
struct ila_lwt *ilwt = ila_lwt_lwtunnel(orig_dst->lwtstate);
struct dst_entry *dst;
int err = -EINVAL;
if (skb->protocol != htons(ETH_P_IPV6))
goto drop;
if (ilwt->lwt_output)
ila_update_ipv6_locator(skb,
ila_params_lwtunnel(orig_dst->lwtstate),
true);
if (rt->rt6i_flags & (RTF_GATEWAY | RTF_CACHE)) {
/* Already have a next hop address in route, no need for
* dest cache route.
*/
return orig_dst->lwtstate->orig_output(net, sk, skb);
}
local_bh_disable();
dst = dst_cache_get(&ilwt->dst_cache);
local_bh_enable();
if (unlikely(!dst)) {
struct ipv6hdr *ip6h = ipv6_hdr(skb);
struct flowi6 fl6;
/* Lookup a route for the new destination. Take into
* account that the base route may already have a gateway.
*/
memset(&fl6, 0, sizeof(fl6));
fl6.flowi6_oif = orig_dst->dev->ifindex;
fl6.flowi6_iif = LOOPBACK_IFINDEX;
fl6.daddr = *rt6_nexthop(dst_rt6_info(orig_dst),
&ip6h->daddr);
dst = ip6_route_output(net, NULL, &fl6);
if (dst->error) {
err = -EHOSTUNREACH;
dst_release(dst);
goto drop;
}
dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
if (IS_ERR(dst)) {
err = PTR_ERR(dst);
goto drop;
}
if (ilwt->connected) {
local_bh_disable();
dst_cache_set_ip6(&ilwt->dst_cache, dst, &fl6.saddr);
local_bh_enable();
}
}
skb_dst_set(skb, dst);
return dst_output(net, sk, skb);
drop:
kfree_skb(skb);
return err;
}
static int ila_input(struct sk_buff *skb)
{
struct dst_entry *dst = skb_dst(skb);
struct ila_lwt *ilwt = ila_lwt_lwtunnel(dst->lwtstate);
if (skb->protocol != htons(ETH_P_IPV6))
goto drop;
if (!ilwt->lwt_output)
ila_update_ipv6_locator(skb,
ila_params_lwtunnel(dst->lwtstate),
false);
return dst->lwtstate->orig_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
static const struct nla_policy ila_nl_policy[ILA_ATTR_MAX + 1] = {
[ILA_ATTR_LOCATOR] = { .type = NLA_U64, },
[ILA_ATTR_CSUM_MODE] = { .type = NLA_U8, },
[ILA_ATTR_IDENT_TYPE] = { .type = NLA_U8, },
[ILA_ATTR_HOOK_TYPE] = { .type = NLA_U8, },
};
static int ila_build_state(struct net *net, struct nlattr *nla,
unsigned int family, const void *cfg,
struct lwtunnel_state **ts,
struct netlink_ext_ack *extack)
{
struct ila_lwt *ilwt;
struct ila_params *p;
struct nlattr *tb[ILA_ATTR_MAX + 1];
struct lwtunnel_state *newts;
const struct fib6_config *cfg6 = cfg;
struct ila_addr *iaddr;
u8 ident_type = ILA_ATYPE_USE_FORMAT;
u8 hook_type = ILA_HOOK_ROUTE_OUTPUT;
u8 csum_mode = ILA_CSUM_NO_ACTION;
bool lwt_output = true;
u8 eff_ident_type;
int ret;
if (family != AF_INET6)
return -EINVAL;
ret = nla_parse_nested_deprecated(tb, ILA_ATTR_MAX, nla,
ila_nl_policy, extack);
if (ret < 0)
return ret;
if (!tb[ILA_ATTR_LOCATOR])
return -EINVAL;
iaddr = (struct ila_addr *)&cfg6->fc_dst;
if (tb[ILA_ATTR_IDENT_TYPE])
ident_type = nla_get_u8(tb[ILA_ATTR_IDENT_TYPE]);
if (ident_type == ILA_ATYPE_USE_FORMAT) {
/* Infer identifier type from type field in formatted
* identifier.
*/
if (cfg6->fc_dst_len < 8 * sizeof(struct ila_locator) + 3) {
/* Need to have full locator and at least type field
* included in destination
*/
return -EINVAL;
}
eff_ident_type = iaddr->ident.type;
} else {
eff_ident_type = ident_type;
}
switch (eff_ident_type) {
case ILA_ATYPE_IID:
/* Don't allow ILA for IID type */
return -EINVAL;
case ILA_ATYPE_LUID:
break;
case ILA_ATYPE_VIRT_V4:
case ILA_ATYPE_VIRT_UNI_V6:
case ILA_ATYPE_VIRT_MULTI_V6:
case ILA_ATYPE_NONLOCAL_ADDR:
/* These ILA formats are not supported yet. */
default:
return -EINVAL;
}
if (tb[ILA_ATTR_HOOK_TYPE])
hook_type = nla_get_u8(tb[ILA_ATTR_HOOK_TYPE]);
switch (hook_type) {
case ILA_HOOK_ROUTE_OUTPUT:
lwt_output = true;
break;
case ILA_HOOK_ROUTE_INPUT:
lwt_output = false;
break;
default:
return -EINVAL;
}
if (tb[ILA_ATTR_CSUM_MODE])
csum_mode = nla_get_u8(tb[ILA_ATTR_CSUM_MODE]);
if (csum_mode == ILA_CSUM_NEUTRAL_MAP &&
ila_csum_neutral_set(iaddr->ident)) {
/* Don't allow translation if checksum neutral bit is
* configured and it's set in the SIR address.
*/
return -EINVAL;
}
newts = lwtunnel_state_alloc(sizeof(*ilwt));
if (!newts)
return -ENOMEM;
ilwt = ila_lwt_lwtunnel(newts);
ret = dst_cache_init(&ilwt->dst_cache, GFP_ATOMIC);
if (ret) {
kfree(newts);
return ret;
}
ilwt->lwt_output = !!lwt_output;
p = ila_params_lwtunnel(newts);
p->csum_mode = csum_mode;
p->ident_type = ident_type;
p->locator.v64 = (__force __be64)nla_get_u64(tb[ILA_ATTR_LOCATOR]);
/* Precompute checksum difference for translation since we
* know both the old locator and the new one.
*/
p->locator_match = iaddr->loc;
ila_init_saved_csum(p);
newts->type = LWTUNNEL_ENCAP_ILA;
newts->flags |= LWTUNNEL_STATE_OUTPUT_REDIRECT |
LWTUNNEL_STATE_INPUT_REDIRECT;
if (cfg6->fc_dst_len == 8 * sizeof(struct in6_addr))
ilwt->connected = 1;
*ts = newts;
return 0;
}
static void ila_destroy_state(struct lwtunnel_state *lwt)
{
dst_cache_destroy(&ila_lwt_lwtunnel(lwt)->dst_cache);
}
static int ila_fill_encap_info(struct sk_buff *skb,
struct lwtunnel_state *lwtstate)
{
struct ila_params *p = ila_params_lwtunnel(lwtstate);
struct ila_lwt *ilwt = ila_lwt_lwtunnel(lwtstate);
if (nla_put_u64_64bit(skb, ILA_ATTR_LOCATOR, (__force u64)p->locator.v64,
ILA_ATTR_PAD))
goto nla_put_failure;
if (nla_put_u8(skb, ILA_ATTR_CSUM_MODE, (__force u8)p->csum_mode))
goto nla_put_failure;
if (nla_put_u8(skb, ILA_ATTR_IDENT_TYPE, (__force u8)p->ident_type))
goto nla_put_failure;
if (nla_put_u8(skb, ILA_ATTR_HOOK_TYPE,
ilwt->lwt_output ? ILA_HOOK_ROUTE_OUTPUT :
ILA_HOOK_ROUTE_INPUT))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static int ila_encap_nlsize(struct lwtunnel_state *lwtstate)
{
return nla_total_size_64bit(sizeof(u64)) + /* ILA_ATTR_LOCATOR */
nla_total_size(sizeof(u8)) + /* ILA_ATTR_CSUM_MODE */
nla_total_size(sizeof(u8)) + /* ILA_ATTR_IDENT_TYPE */
nla_total_size(sizeof(u8)) + /* ILA_ATTR_HOOK_TYPE */
0;
}
static int ila_encap_cmp(struct lwtunnel_state *a, struct lwtunnel_state *b)
{
struct ila_params *a_p = ila_params_lwtunnel(a);
struct ila_params *b_p = ila_params_lwtunnel(b);
return (a_p->locator.v64 != b_p->locator.v64);
}
static const struct lwtunnel_encap_ops ila_encap_ops = {
.build_state = ila_build_state,
.destroy_state = ila_destroy_state,
.output = ila_output,
.input = ila_input,
.fill_encap = ila_fill_encap_info,
.get_encap_size = ila_encap_nlsize,
.cmp_encap = ila_encap_cmp,
.owner = THIS_MODULE,
};
int ila_lwt_init(void)
{
return lwtunnel_encap_add_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA);
}
void ila_lwt_fini(void)
{
lwtunnel_encap_del_ops(&ila_encap_ops, LWTUNNEL_ENCAP_ILA);
}
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