// SPDX-License-Identifier: GPL-2.0-or-later
/*
* SR-IPv6 implementation
*
* Authors:
* David Lebrun <[email protected]>
* eBPF support: Mathieu Xhonneux <[email protected]>
*/
#include <linux/filter.h>
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/net.h>
#include <linux/module.h>
#include <net/ip.h>
#include <net/lwtunnel.h>
#include <net/netevent.h>
#include <net/netns/generic.h>
#include <net/ip6_fib.h>
#include <net/route.h>
#include <net/seg6.h>
#include <linux/seg6.h>
#include <linux/seg6_local.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>
#include <net/dst_cache.h>
#include <net/ip_tunnels.h>
#ifdef CONFIG_IPV6_SEG6_HMAC
#include <net/seg6_hmac.h>
#endif
#include <net/seg6_local.h>
#include <linux/etherdevice.h>
#include <linux/bpf.h>
#include <linux/netfilter.h>
#define SEG6_F_ATTR(i) BIT(i)
struct seg6_local_lwt;
/* callbacks used for customizing the creation and destruction of a behavior */
struct seg6_local_lwtunnel_ops {
int (*build_state)(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack);
void (*destroy_state)(struct seg6_local_lwt *slwt);
};
struct seg6_action_desc {
int action;
unsigned long attrs;
/* The optattrs field is used for specifying all the optional
* attributes supported by a specific behavior.
* It means that if one of these attributes is not provided in the
* netlink message during the behavior creation, no errors will be
* returned to the userspace.
*
* Each attribute can be only of two types (mutually exclusive):
* 1) required or 2) optional.
* Every user MUST obey to this rule! If you set an attribute as
* required the same attribute CANNOT be set as optional and vice
* versa.
*/
unsigned long optattrs;
int (*input)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
int static_headroom;
struct seg6_local_lwtunnel_ops slwt_ops;
};
struct bpf_lwt_prog {
struct bpf_prog *prog;
char *name;
};
/* default length values (expressed in bits) for both Locator-Block and
* Locator-Node Function.
*
* Both SEG6_LOCAL_LCBLOCK_DBITS and SEG6_LOCAL_LCNODE_FN_DBITS *must* be:
* i) greater than 0;
* ii) evenly divisible by 8. In other terms, the lengths of the
* Locator-Block and Locator-Node Function must be byte-aligned (we can
* relax this constraint in the future if really needed).
*
* Moreover, a third condition must hold:
* iii) SEG6_LOCAL_LCBLOCK_DBITS + SEG6_LOCAL_LCNODE_FN_DBITS <= 128.
*
* The correctness of SEG6_LOCAL_LCBLOCK_DBITS and SEG6_LOCAL_LCNODE_FN_DBITS
* values are checked during the kernel compilation. If the compilation stops,
* check the value of these parameters to see if they meet conditions (i), (ii)
* and (iii).
*/
#define SEG6_LOCAL_LCBLOCK_DBITS 32
#define SEG6_LOCAL_LCNODE_FN_DBITS 16
/* The following next_csid_chk_{cntr,lcblock,lcblock_fn}_bits macros can be
* used directly to check whether the lengths (in bits) of Locator-Block and
* Locator-Node Function are valid according to (i), (ii), (iii).
*/
#define next_csid_chk_cntr_bits(blen, flen) \
((blen) + (flen) > 128)
#define next_csid_chk_lcblock_bits(blen) \
({ \
typeof(blen) __tmp = blen; \
(!__tmp || __tmp > 120 || (__tmp & 0x07)); \
})
#define next_csid_chk_lcnode_fn_bits(flen) \
next_csid_chk_lcblock_bits(flen)
/* flag indicating that flavors are set up for a given End* behavior */
#define SEG6_F_LOCAL_FLAVORS SEG6_F_ATTR(SEG6_LOCAL_FLAVORS)
#define SEG6_F_LOCAL_FLV_OP(flvname) BIT(SEG6_LOCAL_FLV_OP_##flvname)
#define SEG6_F_LOCAL_FLV_NEXT_CSID SEG6_F_LOCAL_FLV_OP(NEXT_CSID)
#define SEG6_F_LOCAL_FLV_PSP SEG6_F_LOCAL_FLV_OP(PSP)
/* Supported RFC8986 Flavor operations are reported in this bitmask */
#define SEG6_LOCAL_FLV8986_SUPP_OPS SEG6_F_LOCAL_FLV_PSP
#define SEG6_LOCAL_END_FLV_SUPP_OPS (SEG6_F_LOCAL_FLV_NEXT_CSID | \
SEG6_LOCAL_FLV8986_SUPP_OPS)
#define SEG6_LOCAL_END_X_FLV_SUPP_OPS SEG6_F_LOCAL_FLV_NEXT_CSID
struct seg6_flavors_info {
/* Flavor operations */
__u32 flv_ops;
/* Locator-Block length, expressed in bits */
__u8 lcblock_bits;
/* Locator-Node Function length, expressed in bits*/
__u8 lcnode_func_bits;
};
enum seg6_end_dt_mode {
DT_INVALID_MODE = -EINVAL,
DT_LEGACY_MODE = 0,
DT_VRF_MODE = 1,
};
struct seg6_end_dt_info {
enum seg6_end_dt_mode mode;
struct net *net;
/* VRF device associated to the routing table used by the SRv6
* End.DT4/DT6 behavior for routing IPv4/IPv6 packets.
*/
int vrf_ifindex;
int vrf_table;
/* tunneled packet family (IPv4 or IPv6).
* Protocol and header length are inferred from family.
*/
u16 family;
};
struct pcpu_seg6_local_counters {
u64_stats_t packets;
u64_stats_t bytes;
u64_stats_t errors;
struct u64_stats_sync syncp;
};
/* This struct groups all the SRv6 Behavior counters supported so far.
*
* put_nla_counters() makes use of this data structure to collect all counter
* values after the per-CPU counter evaluation has been performed.
* Finally, each counter value (in seg6_local_counters) is stored in the
* corresponding netlink attribute and sent to user space.
*
* NB: we don't want to expose this structure to user space!
*/
struct seg6_local_counters {
__u64 packets;
__u64 bytes;
__u64 errors;
};
#define seg6_local_alloc_pcpu_counters(__gfp) \
__netdev_alloc_pcpu_stats(struct pcpu_seg6_local_counters, \
((__gfp) | __GFP_ZERO))
#define SEG6_F_LOCAL_COUNTERS SEG6_F_ATTR(SEG6_LOCAL_COUNTERS)
struct seg6_local_lwt {
int action;
struct ipv6_sr_hdr *srh;
int table;
struct in_addr nh4;
struct in6_addr nh6;
int iif;
int oif;
struct bpf_lwt_prog bpf;
#ifdef CONFIG_NET_L3_MASTER_DEV
struct seg6_end_dt_info dt_info;
#endif
struct seg6_flavors_info flv_info;
struct pcpu_seg6_local_counters __percpu *pcpu_counters;
int headroom;
struct seg6_action_desc *desc;
/* unlike the required attrs, we have to track the optional attributes
* that have been effectively parsed.
*/
unsigned long parsed_optattrs;
};
static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt)
{
return (struct seg6_local_lwt *)lwt->data;
}
static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb)
{
struct ipv6_sr_hdr *srh;
srh = seg6_get_srh(skb, IP6_FH_F_SKIP_RH);
if (!srh)
return NULL;
#ifdef CONFIG_IPV6_SEG6_HMAC
if (!seg6_hmac_validate_skb(skb))
return NULL;
#endif
return srh;
}
static bool decap_and_validate(struct sk_buff *skb, int proto)
{
struct ipv6_sr_hdr *srh;
unsigned int off = 0;
srh = seg6_get_srh(skb, 0);
if (srh && srh->segments_left > 0)
return false;
#ifdef CONFIG_IPV6_SEG6_HMAC
if (srh && !seg6_hmac_validate_skb(skb))
return false;
#endif
if (ipv6_find_hdr(skb, &off, proto, NULL, NULL) < 0)
return false;
if (!pskb_pull(skb, off))
return false;
skb_postpull_rcsum(skb, skb_network_header(skb), off);
skb_reset_network_header(skb);
skb_reset_transport_header(skb);
if (iptunnel_pull_offloads(skb))
return false;
return true;
}
static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr)
{
struct in6_addr *addr;
srh->segments_left--;
addr = srh->segments + srh->segments_left;
*daddr = *addr;
}
static int
seg6_lookup_any_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
u32 tbl_id, bool local_delivery)
{
struct net *net = dev_net(skb->dev);
struct ipv6hdr *hdr = ipv6_hdr(skb);
int flags = RT6_LOOKUP_F_HAS_SADDR;
struct dst_entry *dst = NULL;
struct rt6_info *rt;
struct flowi6 fl6;
int dev_flags = 0;
memset(&fl6, 0, sizeof(fl6));
fl6.flowi6_iif = skb->dev->ifindex;
fl6.daddr = nhaddr ? *nhaddr : hdr->daddr;
fl6.saddr = hdr->saddr;
fl6.flowlabel = ip6_flowinfo(hdr);
fl6.flowi6_mark = skb->mark;
fl6.flowi6_proto = hdr->nexthdr;
if (nhaddr)
fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH;
if (!tbl_id) {
dst = ip6_route_input_lookup(net, skb->dev, &fl6, skb, flags);
} else {
struct fib6_table *table;
table = fib6_get_table(net, tbl_id);
if (!table)
goto out;
rt = ip6_pol_route(net, table, 0, &fl6, skb, flags);
dst = &rt->dst;
}
/* we want to discard traffic destined for local packet processing,
* if @local_delivery is set to false.
*/
if (!local_delivery)
dev_flags |= IFF_LOOPBACK;
if (dst && (dst->dev->flags & dev_flags) && !dst->error) {
dst_release(dst);
dst = NULL;
}
out:
if (!dst) {
rt = net->ipv6.ip6_blk_hole_entry;
dst = &rt->dst;
dst_hold(dst);
}
skb_dst_drop(skb);
skb_dst_set(skb, dst);
return dst->error;
}
int seg6_lookup_nexthop(struct sk_buff *skb,
struct in6_addr *nhaddr, u32 tbl_id)
{
return seg6_lookup_any_nexthop(skb, nhaddr, tbl_id, false);
}
static __u8 seg6_flv_lcblock_octects(const struct seg6_flavors_info *finfo)
{
return finfo->lcblock_bits >> 3;
}
static __u8 seg6_flv_lcnode_func_octects(const struct seg6_flavors_info *finfo)
{
return finfo->lcnode_func_bits >> 3;
}
static bool seg6_next_csid_is_arg_zero(const struct in6_addr *addr,
const struct seg6_flavors_info *finfo)
{
__u8 fnc_octects = seg6_flv_lcnode_func_octects(finfo);
__u8 blk_octects = seg6_flv_lcblock_octects(finfo);
__u8 arg_octects;
int i;
arg_octects = 16 - blk_octects - fnc_octects;
for (i = 0; i < arg_octects; ++i) {
if (addr->s6_addr[blk_octects + fnc_octects + i] != 0x00)
return false;
}
return true;
}
/* assume that DA.Argument length > 0 */
static void seg6_next_csid_advance_arg(struct in6_addr *addr,
const struct seg6_flavors_info *finfo)
{
__u8 fnc_octects = seg6_flv_lcnode_func_octects(finfo);
__u8 blk_octects = seg6_flv_lcblock_octects(finfo);
/* advance DA.Argument */
memmove(&addr->s6_addr[blk_octects],
&addr->s6_addr[blk_octects + fnc_octects],
16 - blk_octects - fnc_octects);
memset(&addr->s6_addr[16 - fnc_octects], 0x00, fnc_octects);
}
static int input_action_end_finish(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
seg6_lookup_nexthop(skb, NULL, 0);
return dst_input(skb);
}
static int input_action_end_core(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
return input_action_end_finish(skb, slwt);
drop:
kfree_skb(skb);
return -EINVAL;
}
static int end_next_csid_core(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
const struct seg6_flavors_info *finfo = &slwt->flv_info;
struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
if (seg6_next_csid_is_arg_zero(daddr, finfo))
return input_action_end_core(skb, slwt);
/* update DA */
seg6_next_csid_advance_arg(daddr, finfo);
return input_action_end_finish(skb, slwt);
}
static int input_action_end_x_finish(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
seg6_lookup_nexthop(skb, &slwt->nh6, 0);
return dst_input(skb);
}
static int input_action_end_x_core(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
return input_action_end_x_finish(skb, slwt);
drop:
kfree_skb(skb);
return -EINVAL;
}
static int end_x_next_csid_core(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
const struct seg6_flavors_info *finfo = &slwt->flv_info;
struct in6_addr *daddr = &ipv6_hdr(skb)->daddr;
if (seg6_next_csid_is_arg_zero(daddr, finfo))
return input_action_end_x_core(skb, slwt);
/* update DA */
seg6_next_csid_advance_arg(daddr, finfo);
return input_action_end_x_finish(skb, slwt);
}
static bool seg6_next_csid_enabled(__u32 fops)
{
return fops & SEG6_F_LOCAL_FLV_NEXT_CSID;
}
/* Processing of SRv6 End, End.X, and End.T behaviors can be extended through
* the flavors framework. These behaviors must report the subset of (flavor)
* operations they currently implement. In this way, if a user specifies a
* flavor combination that is not supported by a given End* behavior, the
* kernel refuses to instantiate the tunnel reporting the error.
*/
static int seg6_flv_supp_ops_by_action(int action, __u32 *fops)
{
switch (action) {
case SEG6_LOCAL_ACTION_END:
*fops = SEG6_LOCAL_END_FLV_SUPP_OPS;
break;
case SEG6_LOCAL_ACTION_END_X:
*fops = SEG6_LOCAL_END_X_FLV_SUPP_OPS;
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
/* We describe the packet state in relation to the absence/presence of the SRH
* and the Segment Left (SL) field.
* For our purposes, it is not necessary to record the exact value of the SL
* when the SID List consists of two or more segments.
*/
enum seg6_local_pktinfo {
/* the order really matters! */
SEG6_LOCAL_PKTINFO_NOHDR = 0,
SEG6_LOCAL_PKTINFO_SL_ZERO,
SEG6_LOCAL_PKTINFO_SL_ONE,
SEG6_LOCAL_PKTINFO_SL_MORE,
__SEG6_LOCAL_PKTINFO_MAX,
};
#define SEG6_LOCAL_PKTINFO_MAX (__SEG6_LOCAL_PKTINFO_MAX - 1)
static enum seg6_local_pktinfo seg6_get_srh_pktinfo(struct ipv6_sr_hdr *srh)
{
__u8 sgl;
if (!srh)
return SEG6_LOCAL_PKTINFO_NOHDR;
sgl = srh->segments_left;
if (sgl < 2)
return SEG6_LOCAL_PKTINFO_SL_ZERO + sgl;
return SEG6_LOCAL_PKTINFO_SL_MORE;
}
enum seg6_local_flv_action {
SEG6_LOCAL_FLV_ACT_UNSPEC = 0,
SEG6_LOCAL_FLV_ACT_END,
SEG6_LOCAL_FLV_ACT_PSP,
SEG6_LOCAL_FLV_ACT_USP,
SEG6_LOCAL_FLV_ACT_USD,
__SEG6_LOCAL_FLV_ACT_MAX
};
#define SEG6_LOCAL_FLV_ACT_MAX (__SEG6_LOCAL_FLV_ACT_MAX - 1)
/* The action table for RFC8986 flavors (see the flv8986_act_tbl below)
* contains the actions (i.e. processing operations) to be applied on packets
* when flavors are configured for an End* behavior.
* By combining the pkinfo data and from the flavors mask, the macro
* computes the index used to access the elements (actions) stored in the
* action table. The index is structured as follows:
*
* index
* _______________/\________________
* / \
* +----------------+----------------+
* | pf | afm |
* +----------------+----------------+
* ph-1 ... p1 p0 fk-1 ... f1 f0
* MSB LSB
*
* where:
* - 'afm' (adjusted flavor mask) is the mask containing a combination of the
* RFC8986 flavors currently supported. 'afm' corresponds to the @fm
* argument of the macro whose value is righ-shifted by 1 bit. By doing so,
* we discard the SEG6_LOCAL_FLV_OP_UNSPEC flag (bit 0 in @fm) which is
* never used here;
* - 'pf' encodes the packet info (pktinfo) regarding the presence/absence of
* the SRH, SL = 0, etc. 'pf' is set with the value of @pf provided as
* argument to the macro.
*/
#define flv8986_act_tbl_idx(pf, fm) \
((((pf) << bits_per(SEG6_LOCAL_FLV8986_SUPP_OPS)) | \
((fm) & SEG6_LOCAL_FLV8986_SUPP_OPS)) >> SEG6_LOCAL_FLV_OP_PSP)
/* We compute the size of the action table by considering the RFC8986 flavors
* actually supported by the kernel. In this way, the size is automatically
* adjusted when new flavors are supported.
*/
#define FLV8986_ACT_TBL_SIZE \
roundup_pow_of_two(flv8986_act_tbl_idx(SEG6_LOCAL_PKTINFO_MAX, \
SEG6_LOCAL_FLV8986_SUPP_OPS))
/* tbl_cfg(act, pf, fm) macro is used to easily configure the action
* table; it accepts 3 arguments:
* i) @act, the suffix from SEG6_LOCAL_FLV_ACT_{act} representing
* the action that should be applied on the packet;
* ii) @pf, the suffix from SEG6_LOCAL_PKTINFO_{pf} reporting the packet
* info about the lack/presence of SRH, SRH with SL = 0, etc;
* iii) @fm, the mask of flavors.
*/
#define tbl_cfg(act, pf, fm) \
[flv8986_act_tbl_idx(SEG6_LOCAL_PKTINFO_##pf, \
(fm))] = SEG6_LOCAL_FLV_ACT_##act
/* shorthand for improving readability */
#define F_PSP SEG6_F_LOCAL_FLV_PSP
/* The table contains, for each combination of the pktinfo data and
* flavors, the action that should be taken on a packet (e.g.
* "standard" Endpoint processing, Penultimate Segment Pop, etc).
*
* By default, table entries not explicitly configured are initialized with the
* SEG6_LOCAL_FLV_ACT_UNSPEC action, which generally has the effect of
* discarding the processed packet.
*/
static const u8 flv8986_act_tbl[FLV8986_ACT_TBL_SIZE] = {
/* PSP variant for packet where SRH with SL = 1 */
tbl_cfg(PSP, SL_ONE, F_PSP),
/* End for packet where the SRH with SL > 1*/
tbl_cfg(END, SL_MORE, F_PSP),
};
#undef F_PSP
#undef tbl_cfg
/* For each flavor defined in RFC8986 (or a combination of them) an action is
* performed on the packet. The specific action depends on:
* - info extracted from the packet (i.e. pktinfo data) regarding the
* lack/presence of the SRH, and if the SRH is available, on the value of
* Segment Left field;
* - the mask of flavors configured for the specific SRv6 End* behavior.
*
* The function combines both the pkinfo and the flavors mask to evaluate the
* corresponding action to be taken on the packet.
*/
static enum seg6_local_flv_action
seg6_local_flv8986_act_lookup(enum seg6_local_pktinfo pinfo, __u32 flvmask)
{
unsigned long index;
/* check if the provided mask of flavors is supported */
if (unlikely(flvmask & ~SEG6_LOCAL_FLV8986_SUPP_OPS))
return SEG6_LOCAL_FLV_ACT_UNSPEC;
index = flv8986_act_tbl_idx(pinfo, flvmask);
if (unlikely(index >= FLV8986_ACT_TBL_SIZE))
return SEG6_LOCAL_FLV_ACT_UNSPEC;
return flv8986_act_tbl[index];
}
/* skb->data must be aligned with skb->network_header */
static bool seg6_pop_srh(struct sk_buff *skb, int srhoff)
{
struct ipv6_sr_hdr *srh;
struct ipv6hdr *iph;
__u8 srh_nexthdr;
int thoff = -1;
int srhlen;
int nhlen;
if (unlikely(srhoff < sizeof(*iph) ||
!pskb_may_pull(skb, srhoff + sizeof(*srh))))
return false;
srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
srhlen = ipv6_optlen(srh);
/* we are about to mangle the pkt, let's check if we can write on it */
if (unlikely(skb_ensure_writable(skb, srhoff + srhlen)))
return false;
/* skb_ensure_writable() may change skb pointers; evaluate srh again */
srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
srh_nexthdr = srh->nexthdr;
if (unlikely(!skb_transport_header_was_set(skb)))
goto pull;
nhlen = skb_network_header_len(skb);
/* we have to deal with the transport header: it could be set before
* the SRH, after the SRH, or within it (which is considered wrong,
* however).
*/
if (likely(nhlen <= srhoff))
thoff = nhlen;
else if (nhlen >= srhoff + srhlen)
/* transport_header is set after the SRH */
thoff = nhlen - srhlen;
else
/* transport_header falls inside the SRH; hence, we can't
* restore the transport_header pointer properly after
* SRH removing operation.
*/
return false;
pull:
/* we need to pop the SRH:
* 1) first of all, we pull out everything from IPv6 header up to SRH
* (included) evaluating also the rcsum;
* 2) we overwrite (and then remove) the SRH by properly moving the
* IPv6 along with any extension header that precedes the SRH;
* 3) At the end, we push back the pulled headers (except for SRH,
* obviously).
*/
skb_pull_rcsum(skb, srhoff + srhlen);
memmove(skb_network_header(skb) + srhlen, skb_network_header(skb),
srhoff);
skb_push(skb, srhoff);
skb_reset_network_header(skb);
skb_mac_header_rebuild(skb);
if (likely(thoff >= 0))
skb_set_transport_header(skb, thoff);
iph = ipv6_hdr(skb);
if (iph->nexthdr == NEXTHDR_ROUTING) {
iph->nexthdr = srh_nexthdr;
} else {
/* we must look for the extension header (EXTH, for short) that
* immediately precedes the SRH we have just removed.
* Then, we update the value of the EXTH nexthdr with the one
* contained in the SRH nexthdr.
*/
unsigned int off = sizeof(*iph);
struct ipv6_opt_hdr *hp, _hdr;
__u8 nexthdr = iph->nexthdr;
for (;;) {
if (unlikely(!ipv6_ext_hdr(nexthdr) ||
nexthdr == NEXTHDR_NONE))
return false;
hp = skb_header_pointer(skb, off, sizeof(_hdr), &_hdr);
if (unlikely(!hp))
return false;
if (hp->nexthdr == NEXTHDR_ROUTING) {
hp->nexthdr = srh_nexthdr;
break;
}
switch (nexthdr) {
case NEXTHDR_FRAGMENT:
fallthrough;
case NEXTHDR_AUTH:
/* we expect SRH before FRAG and AUTH */
return false;
default:
off += ipv6_optlen(hp);
break;
}
nexthdr = hp->nexthdr;
}
}
iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
skb_postpush_rcsum(skb, iph, srhoff);
return true;
}
/* process the packet on the basis of the RFC8986 flavors set for the given
* SRv6 End behavior instance.
*/
static int end_flv8986_core(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
const struct seg6_flavors_info *finfo = &slwt->flv_info;
enum seg6_local_flv_action action;
enum seg6_local_pktinfo pinfo;
struct ipv6_sr_hdr *srh;
__u32 flvmask;
int srhoff;
srh = seg6_get_srh(skb, 0);
srhoff = srh ? ((unsigned char *)srh - skb->data) : 0;
pinfo = seg6_get_srh_pktinfo(srh);
#ifdef CONFIG_IPV6_SEG6_HMAC
if (srh && !seg6_hmac_validate_skb(skb))
goto drop;
#endif
flvmask = finfo->flv_ops;
if (unlikely(flvmask & ~SEG6_LOCAL_FLV8986_SUPP_OPS)) {
pr_warn_once("seg6local: invalid RFC8986 flavors\n");
goto drop;
}
/* retrieve the action triggered by the combination of pktinfo data and
* the flavors mask.
*/
action = seg6_local_flv8986_act_lookup(pinfo, flvmask);
switch (action) {
case SEG6_LOCAL_FLV_ACT_END:
/* process the packet as the "standard" End behavior */
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
break;
case SEG6_LOCAL_FLV_ACT_PSP:
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
if (unlikely(!seg6_pop_srh(skb, srhoff)))
goto drop;
break;
case SEG6_LOCAL_FLV_ACT_UNSPEC:
fallthrough;
default:
/* by default, we drop the packet since we could not find a
* suitable action.
*/
goto drop;
}
return input_action_end_finish(skb, slwt);
drop:
kfree_skb(skb);
return -EINVAL;
}
/* regular endpoint function */
static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
const struct seg6_flavors_info *finfo = &slwt->flv_info;
__u32 fops = finfo->flv_ops;
if (!fops)
return input_action_end_core(skb, slwt);
/* check for the presence of NEXT-C-SID since it applies first */
if (seg6_next_csid_enabled(fops))
return end_next_csid_core(skb, slwt);
/* the specific processing function to be performed on the packet
* depends on the combination of flavors defined in RFC8986 and some
* information extracted from the packet, e.g. presence/absence of SRH,
* Segment Left = 0, etc.
*/
return end_flv8986_core(skb, slwt);
}
/* regular endpoint, and forward to specified nexthop */
static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
const struct seg6_flavors_info *finfo = &slwt->flv_info;
__u32 fops = finfo->flv_ops;
/* check for the presence of NEXT-C-SID since it applies first */
if (seg6_next_csid_enabled(fops))
return end_x_next_csid_core(skb, slwt);
return input_action_end_x_core(skb, slwt);
}
static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
seg6_lookup_nexthop(skb, NULL, slwt->table);
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
/* decapsulate and forward inner L2 frame on specified interface */
static int input_action_end_dx2(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct net *net = dev_net(skb->dev);
struct net_device *odev;
struct ethhdr *eth;
if (!decap_and_validate(skb, IPPROTO_ETHERNET))
goto drop;
if (!pskb_may_pull(skb, ETH_HLEN))
goto drop;
skb_reset_mac_header(skb);
eth = (struct ethhdr *)skb->data;
/* To determine the frame's protocol, we assume it is 802.3. This avoids
* a call to eth_type_trans(), which is not really relevant for our
* use case.
*/
if (!eth_proto_is_802_3(eth->h_proto))
goto drop;
odev = dev_get_by_index_rcu(net, slwt->oif);
if (!odev)
goto drop;
/* As we accept Ethernet frames, make sure the egress device is of
* the correct type.
*/
if (odev->type != ARPHRD_ETHER)
goto drop;
if (!(odev->flags & IFF_UP) || !netif_carrier_ok(odev))
goto drop;
skb_orphan(skb);
if (skb_warn_if_lro(skb))
goto drop;
skb_forward_csum(skb);
if (skb->len - ETH_HLEN > odev->mtu)
goto drop;
skb->dev = odev;
skb->protocol = eth->h_proto;
return dev_queue_xmit(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
static int input_action_end_dx6_finish(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
struct dst_entry *orig_dst = skb_dst(skb);
struct in6_addr *nhaddr = NULL;
struct seg6_local_lwt *slwt;
slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
/* The inner packet is not associated to any local interface,
* so we do not call netif_rx().
*
* If slwt->nh6 is set to ::, then lookup the nexthop for the
* inner packet's DA. Otherwise, use the specified nexthop.
*/
if (!ipv6_addr_any(&slwt->nh6))
nhaddr = &slwt->nh6;
seg6_lookup_nexthop(skb, nhaddr, 0);
return dst_input(skb);
}
/* decapsulate and forward to specified nexthop */
static int input_action_end_dx6(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
/* this function accepts IPv6 encapsulated packets, with either
* an SRH with SL=0, or no SRH.
*/
if (!decap_and_validate(skb, IPPROTO_IPV6))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto drop;
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
nf_reset_ct(skb);
if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
dev_net(skb->dev), NULL, skb, skb->dev,
NULL, input_action_end_dx6_finish);
return input_action_end_dx6_finish(dev_net(skb->dev), NULL, skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
static int input_action_end_dx4_finish(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
struct dst_entry *orig_dst = skb_dst(skb);
struct seg6_local_lwt *slwt;
struct iphdr *iph;
__be32 nhaddr;
int err;
slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
iph = ip_hdr(skb);
nhaddr = slwt->nh4.s_addr ?: iph->daddr;
skb_dst_drop(skb);
err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev);
if (err) {
kfree_skb(skb);
return -EINVAL;
}
return dst_input(skb);
}
static int input_action_end_dx4(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
if (!decap_and_validate(skb, IPPROTO_IPIP))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto drop;
skb->protocol = htons(ETH_P_IP);
skb_set_transport_header(skb, sizeof(struct iphdr));
nf_reset_ct(skb);
if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
return NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING,
dev_net(skb->dev), NULL, skb, skb->dev,
NULL, input_action_end_dx4_finish);
return input_action_end_dx4_finish(dev_net(skb->dev), NULL, skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
#ifdef CONFIG_NET_L3_MASTER_DEV
static struct net *fib6_config_get_net(const struct fib6_config *fib6_cfg)
{
const struct nl_info *nli = &fib6_cfg->fc_nlinfo;
return nli->nl_net;
}
static int __seg6_end_dt_vrf_build(struct seg6_local_lwt *slwt, const void *cfg,
u16 family, struct netlink_ext_ack *extack)
{
struct seg6_end_dt_info *info = &slwt->dt_info;
int vrf_ifindex;
struct net *net;
net = fib6_config_get_net(cfg);
/* note that vrf_table was already set by parse_nla_vrftable() */
vrf_ifindex = l3mdev_ifindex_lookup_by_table_id(L3MDEV_TYPE_VRF, net,
info->vrf_table);
if (vrf_ifindex < 0) {
if (vrf_ifindex == -EPERM) {
NL_SET_ERR_MSG(extack,
"Strict mode for VRF is disabled");
} else if (vrf_ifindex == -ENODEV) {
NL_SET_ERR_MSG(extack,
"Table has no associated VRF device");
} else {
pr_debug("seg6local: SRv6 End.DT* creation error=%d\n",
vrf_ifindex);
}
return vrf_ifindex;
}
info->net = net;
info->vrf_ifindex = vrf_ifindex;
info->family = family;
info->mode = DT_VRF_MODE;
return 0;
}
/* The SRv6 End.DT4/DT6 behavior extracts the inner (IPv4/IPv6) packet and
* routes the IPv4/IPv6 packet by looking at the configured routing table.
*
* In the SRv6 End.DT4/DT6 use case, we can receive traffic (IPv6+Segment
* Routing Header packets) from several interfaces and the outer IPv6
* destination address (DA) is used for retrieving the specific instance of the
* End.DT4/DT6 behavior that should process the packets.
*
* However, the inner IPv4/IPv6 packet is not really bound to any receiving
* interface and thus the End.DT4/DT6 sets the VRF (associated with the
* corresponding routing table) as the *receiving* interface.
* In other words, the End.DT4/DT6 processes a packet as if it has been received
* directly by the VRF (and not by one of its slave devices, if any).
* In this way, the VRF interface is used for routing the IPv4/IPv6 packet in
* according to the routing table configured by the End.DT4/DT6 instance.
*
* This design allows you to get some interesting features like:
* 1) the statistics on rx packets;
* 2) the possibility to install a packet sniffer on the receiving interface
* (the VRF one) for looking at the incoming packets;
* 3) the possibility to leverage the netfilter prerouting hook for the inner
* IPv4 packet.
*
* This function returns:
* - the sk_buff* when the VRF rcv handler has processed the packet correctly;
* - NULL when the skb is consumed by the VRF rcv handler;
* - a pointer which encodes a negative error number in case of error.
* Note that in this case, the function takes care of freeing the skb.
*/
static struct sk_buff *end_dt_vrf_rcv(struct sk_buff *skb, u16 family,
struct net_device *dev)
{
/* based on l3mdev_ip_rcv; we are only interested in the master */
if (unlikely(!netif_is_l3_master(dev) && !netif_has_l3_rx_handler(dev)))
goto drop;
if (unlikely(!dev->l3mdev_ops->l3mdev_l3_rcv))
goto drop;
/* the decap packet IPv4/IPv6 does not come with any mac header info.
* We must unset the mac header to allow the VRF device to rebuild it,
* just in case there is a sniffer attached on the device.
*/
skb_unset_mac_header(skb);
skb = dev->l3mdev_ops->l3mdev_l3_rcv(dev, skb, family);
if (!skb)
/* the skb buffer was consumed by the handler */
return NULL;
/* when a packet is received by a VRF or by one of its slaves, the
* master device reference is set into the skb.
*/
if (unlikely(skb->dev != dev || skb->skb_iif != dev->ifindex))
goto drop;
return skb;
drop:
kfree_skb(skb);
return ERR_PTR(-EINVAL);
}
static struct net_device *end_dt_get_vrf_rcu(struct sk_buff *skb,
struct seg6_end_dt_info *info)
{
int vrf_ifindex = info->vrf_ifindex;
struct net *net = info->net;
if (unlikely(vrf_ifindex < 0))
goto error;
if (unlikely(!net_eq(dev_net(skb->dev), net)))
goto error;
return dev_get_by_index_rcu(net, vrf_ifindex);
error:
return NULL;
}
static struct sk_buff *end_dt_vrf_core(struct sk_buff *skb,
struct seg6_local_lwt *slwt, u16 family)
{
struct seg6_end_dt_info *info = &slwt->dt_info;
struct net_device *vrf;
__be16 protocol;
int hdrlen;
vrf = end_dt_get_vrf_rcu(skb, info);
if (unlikely(!vrf))
goto drop;
switch (family) {
case AF_INET:
protocol = htons(ETH_P_IP);
hdrlen = sizeof(struct iphdr);
break;
case AF_INET6:
protocol = htons(ETH_P_IPV6);
hdrlen = sizeof(struct ipv6hdr);
break;
case AF_UNSPEC:
fallthrough;
default:
goto drop;
}
if (unlikely(info->family != AF_UNSPEC && info->family != family)) {
pr_warn_once("seg6local: SRv6 End.DT* family mismatch");
goto drop;
}
skb->protocol = protocol;
skb_dst_drop(skb);
skb_set_transport_header(skb, hdrlen);
nf_reset_ct(skb);
return end_dt_vrf_rcv(skb, family, vrf);
drop:
kfree_skb(skb);
return ERR_PTR(-EINVAL);
}
static int input_action_end_dt4(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct iphdr *iph;
int err;
if (!decap_and_validate(skb, IPPROTO_IPIP))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct iphdr)))
goto drop;
skb = end_dt_vrf_core(skb, slwt, AF_INET);
if (!skb)
/* packet has been processed and consumed by the VRF */
return 0;
if (IS_ERR(skb))
return PTR_ERR(skb);
iph = ip_hdr(skb);
err = ip_route_input(skb, iph->daddr, iph->saddr, 0, skb->dev);
if (unlikely(err))
goto drop;
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
static int seg6_end_dt4_build(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack)
{
return __seg6_end_dt_vrf_build(slwt, cfg, AF_INET, extack);
}
static enum
seg6_end_dt_mode seg6_end_dt6_parse_mode(struct seg6_local_lwt *slwt)
{
unsigned long parsed_optattrs = slwt->parsed_optattrs;
bool legacy, vrfmode;
legacy = !!(parsed_optattrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE));
vrfmode = !!(parsed_optattrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE));
if (!(legacy ^ vrfmode))
/* both are absent or present: invalid DT6 mode */
return DT_INVALID_MODE;
return legacy ? DT_LEGACY_MODE : DT_VRF_MODE;
}
static enum seg6_end_dt_mode seg6_end_dt6_get_mode(struct seg6_local_lwt *slwt)
{
struct seg6_end_dt_info *info = &slwt->dt_info;
return info->mode;
}
static int seg6_end_dt6_build(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack)
{
enum seg6_end_dt_mode mode = seg6_end_dt6_parse_mode(slwt);
struct seg6_end_dt_info *info = &slwt->dt_info;
switch (mode) {
case DT_LEGACY_MODE:
info->mode = DT_LEGACY_MODE;
return 0;
case DT_VRF_MODE:
return __seg6_end_dt_vrf_build(slwt, cfg, AF_INET6, extack);
default:
NL_SET_ERR_MSG(extack, "table or vrftable must be specified");
return -EINVAL;
}
}
#endif
static int input_action_end_dt6(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
if (!decap_and_validate(skb, IPPROTO_IPV6))
goto drop;
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
goto drop;
#ifdef CONFIG_NET_L3_MASTER_DEV
if (seg6_end_dt6_get_mode(slwt) == DT_LEGACY_MODE)
goto legacy_mode;
/* DT6_VRF_MODE */
skb = end_dt_vrf_core(skb, slwt, AF_INET6);
if (!skb)
/* packet has been processed and consumed by the VRF */
return 0;
if (IS_ERR(skb))
return PTR_ERR(skb);
/* note: this time we do not need to specify the table because the VRF
* takes care of selecting the correct table.
*/
seg6_lookup_any_nexthop(skb, NULL, 0, true);
return dst_input(skb);
legacy_mode:
#endif
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
seg6_lookup_any_nexthop(skb, NULL, slwt->table, true);
return dst_input(skb);
drop:
kfree_skb(skb);
return -EINVAL;
}
#ifdef CONFIG_NET_L3_MASTER_DEV
static int seg6_end_dt46_build(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack)
{
return __seg6_end_dt_vrf_build(slwt, cfg, AF_UNSPEC, extack);
}
static int input_action_end_dt46(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
unsigned int off = 0;
int nexthdr;
nexthdr = ipv6_find_hdr(skb, &off, -1, NULL, NULL);
if (unlikely(nexthdr < 0))
goto drop;
switch (nexthdr) {
case IPPROTO_IPIP:
return input_action_end_dt4(skb, slwt);
case IPPROTO_IPV6:
return input_action_end_dt6(skb, slwt);
}
drop:
kfree_skb(skb);
return -EINVAL;
}
#endif
/* push an SRH on top of the current one */
static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
int err = -EINVAL;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
err = seg6_do_srh_inline(skb, slwt->srh);
if (err)
goto drop;
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
seg6_lookup_nexthop(skb, NULL, 0);
return dst_input(skb);
drop:
kfree_skb(skb);
return err;
}
/* encapsulate within an outer IPv6 header and a specified SRH */
static int input_action_end_b6_encap(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
int err = -EINVAL;
srh = get_and_validate_srh(skb);
if (!srh)
goto drop;
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
skb_reset_inner_headers(skb);
skb->encapsulation = 1;
err = seg6_do_srh_encap(skb, slwt->srh, IPPROTO_IPV6);
if (err)
goto drop;
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
seg6_lookup_nexthop(skb, NULL, 0);
return dst_input(skb);
drop:
kfree_skb(skb);
return err;
}
DEFINE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states) = {
.bh_lock = INIT_LOCAL_LOCK(bh_lock),
};
bool seg6_bpf_has_valid_srh(struct sk_buff *skb)
{
struct seg6_bpf_srh_state *srh_state =
this_cpu_ptr(&seg6_bpf_srh_states);
struct ipv6_sr_hdr *srh = srh_state->srh;
lockdep_assert_held(&srh_state->bh_lock);
if (unlikely(srh == NULL))
return false;
if (unlikely(!srh_state->valid)) {
if ((srh_state->hdrlen & 7) != 0)
return false;
srh->hdrlen = (u8)(srh_state->hdrlen >> 3);
if (!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3, true))
return false;
srh_state->valid = true;
}
return true;
}
static int input_action_end_bpf(struct sk_buff *skb,
struct seg6_local_lwt *slwt)
{
struct seg6_bpf_srh_state *srh_state;
struct ipv6_sr_hdr *srh;
int ret;
srh = get_and_validate_srh(skb);
if (!srh) {
kfree_skb(skb);
return -EINVAL;
}
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
/* The access to the per-CPU buffer srh_state is protected by running
* always in softirq context (with disabled BH). On PREEMPT_RT the
* required locking is provided by the following local_lock_nested_bh()
* statement. It is also accessed by the bpf_lwt_seg6_* helpers via
* bpf_prog_run_save_cb().
*/
local_lock_nested_bh(&seg6_bpf_srh_states.bh_lock);
srh_state = this_cpu_ptr(&seg6_bpf_srh_states);
srh_state->srh = srh;
srh_state->hdrlen = srh->hdrlen << 3;
srh_state->valid = true;
rcu_read_lock();
bpf_compute_data_pointers(skb);
ret = bpf_prog_run_save_cb(slwt->bpf.prog, skb);
rcu_read_unlock();
switch (ret) {
case BPF_OK:
case BPF_REDIRECT:
break;
case BPF_DROP:
goto drop;
default:
pr_warn_once("bpf-seg6local: Illegal return value %u\n", ret);
goto drop;
}
if (srh_state->srh && !seg6_bpf_has_valid_srh(skb))
goto drop;
local_unlock_nested_bh(&seg6_bpf_srh_states.bh_lock);
if (ret != BPF_REDIRECT)
seg6_lookup_nexthop(skb, NULL, 0);
return dst_input(skb);
drop:
local_unlock_nested_bh(&seg6_bpf_srh_states.bh_lock);
kfree_skb(skb);
return -EINVAL;
}
static struct seg6_action_desc seg6_action_table[] = {
{
.action = SEG6_LOCAL_ACTION_END,
.attrs = 0,
.optattrs = SEG6_F_LOCAL_COUNTERS |
SEG6_F_LOCAL_FLAVORS,
.input = input_action_end,
},
{
.action = SEG6_LOCAL_ACTION_END_X,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6),
.optattrs = SEG6_F_LOCAL_COUNTERS |
SEG6_F_LOCAL_FLAVORS,
.input = input_action_end_x,
},
{
.action = SEG6_LOCAL_ACTION_END_T,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_t,
},
{
.action = SEG6_LOCAL_ACTION_END_DX2,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_OIF),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_dx2,
},
{
.action = SEG6_LOCAL_ACTION_END_DX6,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_NH6),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_dx6,
},
{
.action = SEG6_LOCAL_ACTION_END_DX4,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_NH4),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_dx4,
},
{
.action = SEG6_LOCAL_ACTION_END_DT4,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE),
.optattrs = SEG6_F_LOCAL_COUNTERS,
#ifdef CONFIG_NET_L3_MASTER_DEV
.input = input_action_end_dt4,
.slwt_ops = {
.build_state = seg6_end_dt4_build,
},
#endif
},
{
.action = SEG6_LOCAL_ACTION_END_DT6,
#ifdef CONFIG_NET_L3_MASTER_DEV
.attrs = 0,
.optattrs = SEG6_F_LOCAL_COUNTERS |
SEG6_F_ATTR(SEG6_LOCAL_TABLE) |
SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE),
.slwt_ops = {
.build_state = seg6_end_dt6_build,
},
#else
.attrs = SEG6_F_ATTR(SEG6_LOCAL_TABLE),
.optattrs = SEG6_F_LOCAL_COUNTERS,
#endif
.input = input_action_end_dt6,
},
{
.action = SEG6_LOCAL_ACTION_END_DT46,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE),
.optattrs = SEG6_F_LOCAL_COUNTERS,
#ifdef CONFIG_NET_L3_MASTER_DEV
.input = input_action_end_dt46,
.slwt_ops = {
.build_state = seg6_end_dt46_build,
},
#endif
},
{
.action = SEG6_LOCAL_ACTION_END_B6,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_b6,
},
{
.action = SEG6_LOCAL_ACTION_END_B6_ENCAP,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_SRH),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_b6_encap,
.static_headroom = sizeof(struct ipv6hdr),
},
{
.action = SEG6_LOCAL_ACTION_END_BPF,
.attrs = SEG6_F_ATTR(SEG6_LOCAL_BPF),
.optattrs = SEG6_F_LOCAL_COUNTERS,
.input = input_action_end_bpf,
},
};
static struct seg6_action_desc *__get_action_desc(int action)
{
struct seg6_action_desc *desc;
int i, count;
count = ARRAY_SIZE(seg6_action_table);
for (i = 0; i < count; i++) {
desc = &seg6_action_table[i];
if (desc->action == action)
return desc;
}
return NULL;
}
static bool seg6_lwtunnel_counters_enabled(struct seg6_local_lwt *slwt)
{
return slwt->parsed_optattrs & SEG6_F_LOCAL_COUNTERS;
}
static void seg6_local_update_counters(struct seg6_local_lwt *slwt,
unsigned int len, int err)
{
struct pcpu_seg6_local_counters *pcounters;
pcounters = this_cpu_ptr(slwt->pcpu_counters);
u64_stats_update_begin(&pcounters->syncp);
if (likely(!err)) {
u64_stats_inc(&pcounters->packets);
u64_stats_add(&pcounters->bytes, len);
} else {
u64_stats_inc(&pcounters->errors);
}
u64_stats_update_end(&pcounters->syncp);
}
static int seg6_local_input_core(struct net *net, struct sock *sk,
struct sk_buff *skb)
{
struct dst_entry *orig_dst = skb_dst(skb);
struct seg6_action_desc *desc;
struct seg6_local_lwt *slwt;
unsigned int len = skb->len;
int rc;
slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
desc = slwt->desc;
rc = desc->input(skb, slwt);
if (!seg6_lwtunnel_counters_enabled(slwt))
return rc;
seg6_local_update_counters(slwt, len, rc);
return rc;
}
static int seg6_local_input(struct sk_buff *skb)
{
if (skb->protocol != htons(ETH_P_IPV6)) {
kfree_skb(skb);
return -EINVAL;
}
if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN,
dev_net(skb->dev), NULL, skb, skb->dev, NULL,
seg6_local_input_core);
return seg6_local_input_core(dev_net(skb->dev), NULL, skb);
}
static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
[SEG6_LOCAL_ACTION] = { .type = NLA_U32 },
[SEG6_LOCAL_SRH] = { .type = NLA_BINARY },
[SEG6_LOCAL_TABLE] = { .type = NLA_U32 },
[SEG6_LOCAL_VRFTABLE] = { .type = NLA_U32 },
[SEG6_LOCAL_NH4] = { .type = NLA_BINARY,
.len = sizeof(struct in_addr) },
[SEG6_LOCAL_NH6] = { .type = NLA_BINARY,
.len = sizeof(struct in6_addr) },
[SEG6_LOCAL_IIF] = { .type = NLA_U32 },
[SEG6_LOCAL_OIF] = { .type = NLA_U32 },
[SEG6_LOCAL_BPF] = { .type = NLA_NESTED },
[SEG6_LOCAL_COUNTERS] = { .type = NLA_NESTED },
[SEG6_LOCAL_FLAVORS] = { .type = NLA_NESTED },
};
static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
struct ipv6_sr_hdr *srh;
int len;
srh = nla_data(attrs[SEG6_LOCAL_SRH]);
len = nla_len(attrs[SEG6_LOCAL_SRH]);
/* SRH must contain at least one segment */
if (len < sizeof(*srh) + sizeof(struct in6_addr))
return -EINVAL;
if (!seg6_validate_srh(srh, len, false))
return -EINVAL;
slwt->srh = kmemdup(srh, len, GFP_KERNEL);
if (!slwt->srh)
return -ENOMEM;
slwt->headroom += len;
return 0;
}
static int put_nla_srh(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct ipv6_sr_hdr *srh;
struct nlattr *nla;
int len;
srh = slwt->srh;
len = (srh->hdrlen + 1) << 3;
nla = nla_reserve(skb, SEG6_LOCAL_SRH, len);
if (!nla)
return -EMSGSIZE;
memcpy(nla_data(nla), srh, len);
return 0;
}
static int cmp_nla_srh(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
int len = (a->srh->hdrlen + 1) << 3;
if (len != ((b->srh->hdrlen + 1) << 3))
return 1;
return memcmp(a->srh, b->srh, len);
}
static void destroy_attr_srh(struct seg6_local_lwt *slwt)
{
kfree(slwt->srh);
}
static int parse_nla_table(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
slwt->table = nla_get_u32(attrs[SEG6_LOCAL_TABLE]);
return 0;
}
static int put_nla_table(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
if (nla_put_u32(skb, SEG6_LOCAL_TABLE, slwt->table))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_table(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (a->table != b->table)
return 1;
return 0;
}
static struct
seg6_end_dt_info *seg6_possible_end_dt_info(struct seg6_local_lwt *slwt)
{
#ifdef CONFIG_NET_L3_MASTER_DEV
return &slwt->dt_info;
#else
return ERR_PTR(-EOPNOTSUPP);
#endif
}
static int parse_nla_vrftable(struct nlattr **attrs,
struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt);
if (IS_ERR(info))
return PTR_ERR(info);
info->vrf_table = nla_get_u32(attrs[SEG6_LOCAL_VRFTABLE]);
return 0;
}
static int put_nla_vrftable(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct seg6_end_dt_info *info = seg6_possible_end_dt_info(slwt);
if (IS_ERR(info))
return PTR_ERR(info);
if (nla_put_u32(skb, SEG6_LOCAL_VRFTABLE, info->vrf_table))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_vrftable(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
struct seg6_end_dt_info *info_a = seg6_possible_end_dt_info(a);
struct seg6_end_dt_info *info_b = seg6_possible_end_dt_info(b);
if (info_a->vrf_table != info_b->vrf_table)
return 1;
return 0;
}
static int parse_nla_nh4(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
memcpy(&slwt->nh4, nla_data(attrs[SEG6_LOCAL_NH4]),
sizeof(struct in_addr));
return 0;
}
static int put_nla_nh4(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct nlattr *nla;
nla = nla_reserve(skb, SEG6_LOCAL_NH4, sizeof(struct in_addr));
if (!nla)
return -EMSGSIZE;
memcpy(nla_data(nla), &slwt->nh4, sizeof(struct in_addr));
return 0;
}
static int cmp_nla_nh4(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
return memcmp(&a->nh4, &b->nh4, sizeof(struct in_addr));
}
static int parse_nla_nh6(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
memcpy(&slwt->nh6, nla_data(attrs[SEG6_LOCAL_NH6]),
sizeof(struct in6_addr));
return 0;
}
static int put_nla_nh6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct nlattr *nla;
nla = nla_reserve(skb, SEG6_LOCAL_NH6, sizeof(struct in6_addr));
if (!nla)
return -EMSGSIZE;
memcpy(nla_data(nla), &slwt->nh6, sizeof(struct in6_addr));
return 0;
}
static int cmp_nla_nh6(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
return memcmp(&a->nh6, &b->nh6, sizeof(struct in6_addr));
}
static int parse_nla_iif(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
slwt->iif = nla_get_u32(attrs[SEG6_LOCAL_IIF]);
return 0;
}
static int put_nla_iif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
if (nla_put_u32(skb, SEG6_LOCAL_IIF, slwt->iif))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_iif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (a->iif != b->iif)
return 1;
return 0;
}
static int parse_nla_oif(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
slwt->oif = nla_get_u32(attrs[SEG6_LOCAL_OIF]);
return 0;
}
static int put_nla_oif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
if (nla_put_u32(skb, SEG6_LOCAL_OIF, slwt->oif))
return -EMSGSIZE;
return 0;
}
static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (a->oif != b->oif)
return 1;
return 0;
}
#define MAX_PROG_NAME 256
static const struct nla_policy bpf_prog_policy[SEG6_LOCAL_BPF_PROG_MAX + 1] = {
[SEG6_LOCAL_BPF_PROG] = { .type = NLA_U32, },
[SEG6_LOCAL_BPF_PROG_NAME] = { .type = NLA_NUL_STRING,
.len = MAX_PROG_NAME },
};
static int parse_nla_bpf(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[SEG6_LOCAL_BPF_PROG_MAX + 1];
struct bpf_prog *p;
int ret;
u32 fd;
ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_BPF_PROG_MAX,
attrs[SEG6_LOCAL_BPF],
bpf_prog_policy, NULL);
if (ret < 0)
return ret;
if (!tb[SEG6_LOCAL_BPF_PROG] || !tb[SEG6_LOCAL_BPF_PROG_NAME])
return -EINVAL;
slwt->bpf.name = nla_memdup(tb[SEG6_LOCAL_BPF_PROG_NAME], GFP_KERNEL);
if (!slwt->bpf.name)
return -ENOMEM;
fd = nla_get_u32(tb[SEG6_LOCAL_BPF_PROG]);
p = bpf_prog_get_type(fd, BPF_PROG_TYPE_LWT_SEG6LOCAL);
if (IS_ERR(p)) {
kfree(slwt->bpf.name);
return PTR_ERR(p);
}
slwt->bpf.prog = p;
return 0;
}
static int put_nla_bpf(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct nlattr *nest;
if (!slwt->bpf.prog)
return 0;
nest = nla_nest_start_noflag(skb, SEG6_LOCAL_BPF);
if (!nest)
return -EMSGSIZE;
if (nla_put_u32(skb, SEG6_LOCAL_BPF_PROG, slwt->bpf.prog->aux->id))
return -EMSGSIZE;
if (slwt->bpf.name &&
nla_put_string(skb, SEG6_LOCAL_BPF_PROG_NAME, slwt->bpf.name))
return -EMSGSIZE;
return nla_nest_end(skb, nest);
}
static int cmp_nla_bpf(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
if (!a->bpf.name && !b->bpf.name)
return 0;
if (!a->bpf.name || !b->bpf.name)
return 1;
return strcmp(a->bpf.name, b->bpf.name);
}
static void destroy_attr_bpf(struct seg6_local_lwt *slwt)
{
kfree(slwt->bpf.name);
if (slwt->bpf.prog)
bpf_prog_put(slwt->bpf.prog);
}
static const struct
nla_policy seg6_local_counters_policy[SEG6_LOCAL_CNT_MAX + 1] = {
[SEG6_LOCAL_CNT_PACKETS] = { .type = NLA_U64 },
[SEG6_LOCAL_CNT_BYTES] = { .type = NLA_U64 },
[SEG6_LOCAL_CNT_ERRORS] = { .type = NLA_U64 },
};
static int parse_nla_counters(struct nlattr **attrs,
struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
struct pcpu_seg6_local_counters __percpu *pcounters;
struct nlattr *tb[SEG6_LOCAL_CNT_MAX + 1];
int ret;
ret = nla_parse_nested_deprecated(tb, SEG6_LOCAL_CNT_MAX,
attrs[SEG6_LOCAL_COUNTERS],
seg6_local_counters_policy, NULL);
if (ret < 0)
return ret;
/* basic support for SRv6 Behavior counters requires at least:
* packets, bytes and errors.
*/
if (!tb[SEG6_LOCAL_CNT_PACKETS] || !tb[SEG6_LOCAL_CNT_BYTES] ||
!tb[SEG6_LOCAL_CNT_ERRORS])
return -EINVAL;
/* counters are always zero initialized */
pcounters = seg6_local_alloc_pcpu_counters(GFP_KERNEL);
if (!pcounters)
return -ENOMEM;
slwt->pcpu_counters = pcounters;
return 0;
}
static int seg6_local_fill_nla_counters(struct sk_buff *skb,
struct seg6_local_counters *counters)
{
if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_PACKETS, counters->packets,
SEG6_LOCAL_CNT_PAD))
return -EMSGSIZE;
if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_BYTES, counters->bytes,
SEG6_LOCAL_CNT_PAD))
return -EMSGSIZE;
if (nla_put_u64_64bit(skb, SEG6_LOCAL_CNT_ERRORS, counters->errors,
SEG6_LOCAL_CNT_PAD))
return -EMSGSIZE;
return 0;
}
static int put_nla_counters(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct seg6_local_counters counters = { 0, 0, 0 };
struct nlattr *nest;
int rc, i;
nest = nla_nest_start(skb, SEG6_LOCAL_COUNTERS);
if (!nest)
return -EMSGSIZE;
for_each_possible_cpu(i) {
struct pcpu_seg6_local_counters *pcounters;
u64 packets, bytes, errors;
unsigned int start;
pcounters = per_cpu_ptr(slwt->pcpu_counters, i);
do {
start = u64_stats_fetch_begin(&pcounters->syncp);
packets = u64_stats_read(&pcounters->packets);
bytes = u64_stats_read(&pcounters->bytes);
errors = u64_stats_read(&pcounters->errors);
} while (u64_stats_fetch_retry(&pcounters->syncp, start));
counters.packets += packets;
counters.bytes += bytes;
counters.errors += errors;
}
rc = seg6_local_fill_nla_counters(skb, &counters);
if (rc < 0) {
nla_nest_cancel(skb, nest);
return rc;
}
return nla_nest_end(skb, nest);
}
static int cmp_nla_counters(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
/* a and b are equal if both have pcpu_counters set or not */
return (!!((unsigned long)a->pcpu_counters)) ^
(!!((unsigned long)b->pcpu_counters));
}
static void destroy_attr_counters(struct seg6_local_lwt *slwt)
{
free_percpu(slwt->pcpu_counters);
}
static const
struct nla_policy seg6_local_flavors_policy[SEG6_LOCAL_FLV_MAX + 1] = {
[SEG6_LOCAL_FLV_OPERATION] = { .type = NLA_U32 },
[SEG6_LOCAL_FLV_LCBLOCK_BITS] = { .type = NLA_U8 },
[SEG6_LOCAL_FLV_LCNODE_FN_BITS] = { .type = NLA_U8 },
};
/* check whether the lengths of the Locator-Block and Locator-Node Function
* are compatible with the dimension of a C-SID container.
*/
static int seg6_chk_next_csid_cfg(__u8 block_len, __u8 func_len)
{
/* Locator-Block and Locator-Node Function cannot exceed 128 bits
* (i.e. C-SID container lenghts).
*/
if (next_csid_chk_cntr_bits(block_len, func_len))
return -EINVAL;
/* Locator-Block length must be greater than zero and evenly divisible
* by 8. There must be room for a Locator-Node Function, at least.
*/
if (next_csid_chk_lcblock_bits(block_len))
return -EINVAL;
/* Locator-Node Function length must be greater than zero and evenly
* divisible by 8. There must be room for the Locator-Block.
*/
if (next_csid_chk_lcnode_fn_bits(func_len))
return -EINVAL;
return 0;
}
static int seg6_parse_nla_next_csid_cfg(struct nlattr **tb,
struct seg6_flavors_info *finfo,
struct netlink_ext_ack *extack)
{
__u8 func_len = SEG6_LOCAL_LCNODE_FN_DBITS;
__u8 block_len = SEG6_LOCAL_LCBLOCK_DBITS;
int rc;
if (tb[SEG6_LOCAL_FLV_LCBLOCK_BITS])
block_len = nla_get_u8(tb[SEG6_LOCAL_FLV_LCBLOCK_BITS]);
if (tb[SEG6_LOCAL_FLV_LCNODE_FN_BITS])
func_len = nla_get_u8(tb[SEG6_LOCAL_FLV_LCNODE_FN_BITS]);
rc = seg6_chk_next_csid_cfg(block_len, func_len);
if (rc < 0) {
NL_SET_ERR_MSG(extack,
"Invalid Locator Block/Node Function lengths");
return rc;
}
finfo->lcblock_bits = block_len;
finfo->lcnode_func_bits = func_len;
return 0;
}
static int parse_nla_flavors(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
struct seg6_flavors_info *finfo = &slwt->flv_info;
struct nlattr *tb[SEG6_LOCAL_FLV_MAX + 1];
int action = slwt->action;
__u32 fops, supp_fops;
int rc;
rc = nla_parse_nested_deprecated(tb, SEG6_LOCAL_FLV_MAX,
attrs[SEG6_LOCAL_FLAVORS],
seg6_local_flavors_policy, NULL);
if (rc < 0)
return rc;
/* this attribute MUST always be present since it represents the Flavor
* operation(s) to be carried out.
*/
if (!tb[SEG6_LOCAL_FLV_OPERATION])
return -EINVAL;
fops = nla_get_u32(tb[SEG6_LOCAL_FLV_OPERATION]);
rc = seg6_flv_supp_ops_by_action(action, &supp_fops);
if (rc < 0 || (fops & ~supp_fops)) {
NL_SET_ERR_MSG(extack, "Unsupported Flavor operation(s)");
return -EOPNOTSUPP;
}
finfo->flv_ops = fops;
if (seg6_next_csid_enabled(fops)) {
/* Locator-Block and Locator-Node Function lengths can be
* provided by the user space. Otherwise, default values are
* applied.
*/
rc = seg6_parse_nla_next_csid_cfg(tb, finfo, extack);
if (rc < 0)
return rc;
}
return 0;
}
static int seg6_fill_nla_next_csid_cfg(struct sk_buff *skb,
struct seg6_flavors_info *finfo)
{
if (nla_put_u8(skb, SEG6_LOCAL_FLV_LCBLOCK_BITS, finfo->lcblock_bits))
return -EMSGSIZE;
if (nla_put_u8(skb, SEG6_LOCAL_FLV_LCNODE_FN_BITS,
finfo->lcnode_func_bits))
return -EMSGSIZE;
return 0;
}
static int put_nla_flavors(struct sk_buff *skb, struct seg6_local_lwt *slwt)
{
struct seg6_flavors_info *finfo = &slwt->flv_info;
__u32 fops = finfo->flv_ops;
struct nlattr *nest;
int rc;
nest = nla_nest_start(skb, SEG6_LOCAL_FLAVORS);
if (!nest)
return -EMSGSIZE;
if (nla_put_u32(skb, SEG6_LOCAL_FLV_OPERATION, fops)) {
rc = -EMSGSIZE;
goto err;
}
if (seg6_next_csid_enabled(fops)) {
rc = seg6_fill_nla_next_csid_cfg(skb, finfo);
if (rc < 0)
goto err;
}
return nla_nest_end(skb, nest);
err:
nla_nest_cancel(skb, nest);
return rc;
}
static int seg6_cmp_nla_next_csid_cfg(struct seg6_flavors_info *finfo_a,
struct seg6_flavors_info *finfo_b)
{
if (finfo_a->lcblock_bits != finfo_b->lcblock_bits)
return 1;
if (finfo_a->lcnode_func_bits != finfo_b->lcnode_func_bits)
return 1;
return 0;
}
static int cmp_nla_flavors(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
{
struct seg6_flavors_info *finfo_a = &a->flv_info;
struct seg6_flavors_info *finfo_b = &b->flv_info;
if (finfo_a->flv_ops != finfo_b->flv_ops)
return 1;
if (seg6_next_csid_enabled(finfo_a->flv_ops)) {
if (seg6_cmp_nla_next_csid_cfg(finfo_a, finfo_b))
return 1;
}
return 0;
}
static int encap_size_flavors(struct seg6_local_lwt *slwt)
{
struct seg6_flavors_info *finfo = &slwt->flv_info;
int nlsize;
nlsize = nla_total_size(0) + /* nest SEG6_LOCAL_FLAVORS */
nla_total_size(4); /* SEG6_LOCAL_FLV_OPERATION */
if (seg6_next_csid_enabled(finfo->flv_ops))
nlsize += nla_total_size(1) + /* SEG6_LOCAL_FLV_LCBLOCK_BITS */
nla_total_size(1); /* SEG6_LOCAL_FLV_LCNODE_FN_BITS */
return nlsize;
}
struct seg6_action_param {
int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack);
int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b);
/* optional destroy() callback useful for releasing resources which
* have been previously acquired in the corresponding parse()
* function.
*/
void (*destroy)(struct seg6_local_lwt *slwt);
};
static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = {
[SEG6_LOCAL_SRH] = { .parse = parse_nla_srh,
.put = put_nla_srh,
.cmp = cmp_nla_srh,
.destroy = destroy_attr_srh },
[SEG6_LOCAL_TABLE] = { .parse = parse_nla_table,
.put = put_nla_table,
.cmp = cmp_nla_table },
[SEG6_LOCAL_NH4] = { .parse = parse_nla_nh4,
.put = put_nla_nh4,
.cmp = cmp_nla_nh4 },
[SEG6_LOCAL_NH6] = { .parse = parse_nla_nh6,
.put = put_nla_nh6,
.cmp = cmp_nla_nh6 },
[SEG6_LOCAL_IIF] = { .parse = parse_nla_iif,
.put = put_nla_iif,
.cmp = cmp_nla_iif },
[SEG6_LOCAL_OIF] = { .parse = parse_nla_oif,
.put = put_nla_oif,
.cmp = cmp_nla_oif },
[SEG6_LOCAL_BPF] = { .parse = parse_nla_bpf,
.put = put_nla_bpf,
.cmp = cmp_nla_bpf,
.destroy = destroy_attr_bpf },
[SEG6_LOCAL_VRFTABLE] = { .parse = parse_nla_vrftable,
.put = put_nla_vrftable,
.cmp = cmp_nla_vrftable },
[SEG6_LOCAL_COUNTERS] = { .parse = parse_nla_counters,
.put = put_nla_counters,
.cmp = cmp_nla_counters,
.destroy = destroy_attr_counters },
[SEG6_LOCAL_FLAVORS] = { .parse = parse_nla_flavors,
.put = put_nla_flavors,
.cmp = cmp_nla_flavors },
};
/* call the destroy() callback (if available) for each set attribute in
* @parsed_attrs, starting from the first attribute up to the @max_parsed
* (excluded) attribute.
*/
static void __destroy_attrs(unsigned long parsed_attrs, int max_parsed,
struct seg6_local_lwt *slwt)
{
struct seg6_action_param *param;
int i;
/* Every required seg6local attribute is identified by an ID which is
* encoded as a flag (i.e: 1 << ID) in the 'attrs' bitmask;
*
* We scan the 'parsed_attrs' bitmask, starting from the first attribute
* up to the @max_parsed (excluded) attribute.
* For each set attribute, we retrieve the corresponding destroy()
* callback. If the callback is not available, then we skip to the next
* attribute; otherwise, we call the destroy() callback.
*/
for (i = SEG6_LOCAL_SRH; i < max_parsed; ++i) {
if (!(parsed_attrs & SEG6_F_ATTR(i)))
continue;
param = &seg6_action_params[i];
if (param->destroy)
param->destroy(slwt);
}
}
/* release all the resources that may have been acquired during parsing
* operations.
*/
static void destroy_attrs(struct seg6_local_lwt *slwt)
{
unsigned long attrs = slwt->desc->attrs | slwt->parsed_optattrs;
__destroy_attrs(attrs, SEG6_LOCAL_MAX + 1, slwt);
}
static int parse_nla_optional_attrs(struct nlattr **attrs,
struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
struct seg6_action_desc *desc = slwt->desc;
unsigned long parsed_optattrs = 0;
struct seg6_action_param *param;
int err, i;
for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; ++i) {
if (!(desc->optattrs & SEG6_F_ATTR(i)) || !attrs[i])
continue;
/* once here, the i-th attribute is provided by the
* userspace AND it is identified optional as well.
*/
param = &seg6_action_params[i];
err = param->parse(attrs, slwt, extack);
if (err < 0)
goto parse_optattrs_err;
/* current attribute has been correctly parsed */
parsed_optattrs |= SEG6_F_ATTR(i);
}
/* store in the tunnel state all the optional attributed successfully
* parsed.
*/
slwt->parsed_optattrs = parsed_optattrs;
return 0;
parse_optattrs_err:
__destroy_attrs(parsed_optattrs, i, slwt);
return err;
}
/* call the custom constructor of the behavior during its initialization phase
* and after that all its attributes have been parsed successfully.
*/
static int
seg6_local_lwtunnel_build_state(struct seg6_local_lwt *slwt, const void *cfg,
struct netlink_ext_ack *extack)
{
struct seg6_action_desc *desc = slwt->desc;
struct seg6_local_lwtunnel_ops *ops;
ops = &desc->slwt_ops;
if (!ops->build_state)
return 0;
return ops->build_state(slwt, cfg, extack);
}
/* call the custom destructor of the behavior which is invoked before the
* tunnel is going to be destroyed.
*/
static void seg6_local_lwtunnel_destroy_state(struct seg6_local_lwt *slwt)
{
struct seg6_action_desc *desc = slwt->desc;
struct seg6_local_lwtunnel_ops *ops;
ops = &desc->slwt_ops;
if (!ops->destroy_state)
return;
ops->destroy_state(slwt);
}
static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt,
struct netlink_ext_ack *extack)
{
struct seg6_action_param *param;
struct seg6_action_desc *desc;
unsigned long invalid_attrs;
int i, err;
desc = __get_action_desc(slwt->action);
if (!desc)
return -EINVAL;
if (!desc->input)
return -EOPNOTSUPP;
slwt->desc = desc;
slwt->headroom += desc->static_headroom;
/* Forcing the desc->optattrs *set* and the desc->attrs *set* to be
* disjoined, this allow us to release acquired resources by optional
* attributes and by required attributes independently from each other
* without any interference.
* In other terms, we are sure that we do not release some the acquired
* resources twice.
*
* Note that if an attribute is configured both as required and as
* optional, it means that the user has messed something up in the
* seg6_action_table. Therefore, this check is required for SRv6
* behaviors to work properly.
*/
invalid_attrs = desc->attrs & desc->optattrs;
if (invalid_attrs) {
WARN_ONCE(1,
"An attribute cannot be both required AND optional");
return -EINVAL;
}
/* parse the required attributes */
for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) {
if (desc->attrs & SEG6_F_ATTR(i)) {
if (!attrs[i])
return -EINVAL;
param = &seg6_action_params[i];
err = param->parse(attrs, slwt, extack);
if (err < 0)
goto parse_attrs_err;
}
}
/* parse the optional attributes, if any */
err = parse_nla_optional_attrs(attrs, slwt, extack);
if (err < 0)
goto parse_attrs_err;
return 0;
parse_attrs_err:
/* release any resource that may have been acquired during the i-1
* parse() operations.
*/
__destroy_attrs(desc->attrs, i, slwt);
return err;
}
static int seg6_local_build_state(struct net *net, struct nlattr *nla,
unsigned int family, const void *cfg,
struct lwtunnel_state **ts,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[SEG6_LOCAL_MAX + 1];
struct lwtunnel_state *newts;
struct seg6_local_lwt *slwt;
int err;
if (family != AF_INET6)
return -EINVAL;
err = nla_parse_nested_deprecated(tb, SEG6_LOCAL_MAX, nla,
seg6_local_policy, extack);
if (err < 0)
return err;
if (!tb[SEG6_LOCAL_ACTION])
return -EINVAL;
newts = lwtunnel_state_alloc(sizeof(*slwt));
if (!newts)
return -ENOMEM;
slwt = seg6_local_lwtunnel(newts);
slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]);
err = parse_nla_action(tb, slwt, extack);
if (err < 0)
goto out_free;
err = seg6_local_lwtunnel_build_state(slwt, cfg, extack);
if (err < 0)
goto out_destroy_attrs;
newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL;
newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT;
newts->headroom = slwt->headroom;
*ts = newts;
return 0;
out_destroy_attrs:
destroy_attrs(slwt);
out_free:
kfree(newts);
return err;
}
static void seg6_local_destroy_state(struct lwtunnel_state *lwt)
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
seg6_local_lwtunnel_destroy_state(slwt);
destroy_attrs(slwt);
return;
}
static int seg6_local_fill_encap(struct sk_buff *skb,
struct lwtunnel_state *lwt)
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
struct seg6_action_param *param;
unsigned long attrs;
int i, err;
if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action))
return -EMSGSIZE;
attrs = slwt->desc->attrs | slwt->parsed_optattrs;
for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) {
if (attrs & SEG6_F_ATTR(i)) {
param = &seg6_action_params[i];
err = param->put(skb, slwt);
if (err < 0)
return err;
}
}
return 0;
}
static int seg6_local_get_encap_size(struct lwtunnel_state *lwt)
{
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
unsigned long attrs;
int nlsize;
nlsize = nla_total_size(4); /* action */
attrs = slwt->desc->attrs | slwt->parsed_optattrs;
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_SRH))
nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_TABLE))
nlsize += nla_total_size(4);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH4))
nlsize += nla_total_size(4);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_NH6))
nlsize += nla_total_size(16);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_IIF))
nlsize += nla_total_size(4);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_OIF))
nlsize += nla_total_size(4);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_BPF))
nlsize += nla_total_size(sizeof(struct nlattr)) +
nla_total_size(MAX_PROG_NAME) +
nla_total_size(4);
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_VRFTABLE))
nlsize += nla_total_size(4);
if (attrs & SEG6_F_LOCAL_COUNTERS)
nlsize += nla_total_size(0) + /* nest SEG6_LOCAL_COUNTERS */
/* SEG6_LOCAL_CNT_PACKETS */
nla_total_size_64bit(sizeof(__u64)) +
/* SEG6_LOCAL_CNT_BYTES */
nla_total_size_64bit(sizeof(__u64)) +
/* SEG6_LOCAL_CNT_ERRORS */
nla_total_size_64bit(sizeof(__u64));
if (attrs & SEG6_F_ATTR(SEG6_LOCAL_FLAVORS))
nlsize += encap_size_flavors(slwt);
return nlsize;
}
static int seg6_local_cmp_encap(struct lwtunnel_state *a,
struct lwtunnel_state *b)
{
struct seg6_local_lwt *slwt_a, *slwt_b;
struct seg6_action_param *param;
unsigned long attrs_a, attrs_b;
int i;
slwt_a = seg6_local_lwtunnel(a);
slwt_b = seg6_local_lwtunnel(b);
if (slwt_a->action != slwt_b->action)
return 1;
attrs_a = slwt_a->desc->attrs | slwt_a->parsed_optattrs;
attrs_b = slwt_b->desc->attrs | slwt_b->parsed_optattrs;
if (attrs_a != attrs_b)
return 1;
for (i = SEG6_LOCAL_SRH; i < SEG6_LOCAL_MAX + 1; i++) {
if (attrs_a & SEG6_F_ATTR(i)) {
param = &seg6_action_params[i];
if (param->cmp(slwt_a, slwt_b))
return 1;
}
}
return 0;
}
static const struct lwtunnel_encap_ops seg6_local_ops = {
.build_state = seg6_local_build_state,
.destroy_state = seg6_local_destroy_state,
.input = seg6_local_input,
.fill_encap = seg6_local_fill_encap,
.get_encap_size = seg6_local_get_encap_size,
.cmp_encap = seg6_local_cmp_encap,
.owner = THIS_MODULE,
};
int __init seg6_local_init(void)
{
/* If the max total number of defined attributes is reached, then your
* kernel build stops here.
*
* This check is required to avoid arithmetic overflows when processing
* behavior attributes and the maximum number of defined attributes
* exceeds the allowed value.
*/
BUILD_BUG_ON(SEG6_LOCAL_MAX + 1 > BITS_PER_TYPE(unsigned long));
/* Check whether the number of defined flavors exceeds the maximum
* allowed value.
*/
BUILD_BUG_ON(SEG6_LOCAL_FLV_OP_MAX + 1 > BITS_PER_TYPE(__u32));
/* If the default NEXT-C-SID Locator-Block/Node Function lengths (in
* bits) have been changed with invalid values, kernel build stops
* here.
*/
BUILD_BUG_ON(next_csid_chk_cntr_bits(SEG6_LOCAL_LCBLOCK_DBITS,
SEG6_LOCAL_LCNODE_FN_DBITS));
BUILD_BUG_ON(next_csid_chk_lcblock_bits(SEG6_LOCAL_LCBLOCK_DBITS));
BUILD_BUG_ON(next_csid_chk_lcnode_fn_bits(SEG6_LOCAL_LCNODE_FN_DBITS));
/* To be memory efficient, we use 'u8' to represent the different
* actions related to RFC8986 flavors. If the kernel build stops here,
* it means that it is not possible to correctly encode these actions
* with the data type chosen for the action table.
*/
BUILD_BUG_ON(SEG6_LOCAL_FLV_ACT_MAX > (typeof(flv8986_act_tbl[0]))~0U);
return lwtunnel_encap_add_ops(&seg6_local_ops,
LWTUNNEL_ENCAP_SEG6_LOCAL);
}
void seg6_local_exit(void)
{
lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL);
}
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