From 64e35281a8e8e4f7dddc8c8c48ebdb05de1b0da9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?S=C3=A9bastien=20Parisot?= Date: Thu, 12 Feb 2026 16:09:31 +0000 Subject: [PATCH 1/5] nest: Add SRv6 SID stack support to nexthop Add SRv6 SID stack type and constants (SRV6_MAX_SID_STACK, SRV6_MAX_SID_STRING), srv6_sid_stack struct, and nexthop fields (sid6s_orig, sid6s, sid6[]). Extend nexthop_hash(), nexthop_equal_1(), nexthop__same(), nexthop_compare_node(), nexthop_copy() and rta_dump() for SRv6 SID handling. Update rta_apply_hostentry() and rta_set_recursive_next_hop() signatures with SRv6 parameter. Add SRv6 SID display in route show output and propagate SRv6 SIDs through recursive next hop resolution. --- conf/confbase.Y | 16 ++++++++++++++++ lib/ip.h | 7 +++++++ nest/mpls.c | 2 +- nest/route.h | 9 ++++++--- nest/rt-attr.c | 32 ++++++++++++++++++++++++++++++-- nest/rt-show.c | 18 ++++++++++++++---- nest/rt-table.c | 38 +++++++++++++++++++++++++++++++++++--- 7 files changed, 109 insertions(+), 13 deletions(-) diff --git a/conf/confbase.Y b/conf/confbase.Y index 27c422e..3621f37 100644 --- a/conf/confbase.Y +++ b/conf/confbase.Y @@ -125,6 +125,7 @@ CF_DECLS struct timeformat tf; struct timeformat *tfp; mpls_label_stack *mls; + srv6_sid_stack *sid6; const struct adata *bs; struct aggr_item_node *ai; } @@ -148,6 +149,7 @@ CF_DECLS %type net_ip4_ net_ip4 net_ip6_ net_ip6 net_ip_ net_ip net_or_ipa %type net_ net_any net_vpn4_ net_vpn6_ net_vpn_ net_roa4_ net_roa6_ net_roa_ net_ip6_sadr_ net_mpls_ net_aspa_ %type label_stack_start label_stack +%type srv6_sid_stack %type text opttext %type bytestring @@ -442,6 +444,20 @@ label_stack: } ; +srv6_sid_stack: IP6 +{ + $$ = cfg_allocz(sizeof(srv6_sid_stack)); + $$->len = 1; + $$->sid[0] = ipa_from_ip6($1); +} + | srv6_sid_stack ',' IP6 +{ + $$ = $1; + if ($$->len >= SRV6_MAX_SID_STACK) + cf_error("Too many SRv6 SIDs (max %d)", SRV6_MAX_SID_STACK); + $$->sid[$$->len++] = ipa_from_ip6($3); +} +; /* Strings */ diff --git a/lib/ip.h b/lib/ip.h index bae0526..7f3c8cc 100644 --- a/lib/ip.h +++ b/lib/ip.h @@ -393,6 +393,13 @@ static inline ip6_addr ip6_ntoh(ip6_addr a) { return _MI6(ntohl(_I0(a)), ntohl(_I1(a)), ntohl(_I2(a)), ntohl(_I3(a))); } +#define SRV6_MAX_SID_STACK 1 +#define SRV6_MAX_SID_STRING (8 /* " srv6 <" */ + IP6_MAX_TEXT_LENGTH + (1 /* "," */ + IP6_MAX_TEXT_LENGTH) * (SRV6_MAX_SID_STACK - 1) + 1 /* ">" */ + 1 /* '\0' */) +typedef struct srv6_sid_stack { + uint len; + ip6_addr sid[SRV6_MAX_SID_STACK]; +} srv6_sid_stack; + /* * Unaligned data access (in network order) */ diff --git a/nest/mpls.c b/nest/mpls.c index 9cdcd57..20aa09e 100644 --- a/nest/mpls.c +++ b/nest/mpls.c @@ -1065,7 +1065,7 @@ mpls_announce_fec(struct mpls_fec_map *m, struct mpls_fec *fec, const rta *src) /* The same hostentry, but different dependent table */ struct hostentry *s = src->hostentry; - rta_set_recursive_next_hop(m->channel->table, a, s->owner, s->addr, s->link, &ms); + rta_set_recursive_next_hop(m->channel->table, a, s->owner, s->addr, s->link, &ms, NULL); } net_addr_mpls n = NET_ADDR_MPLS(fec->label); diff --git a/nest/route.h b/nest/route.h index 5a9e7fa..3addc17 100644 --- a/nest/route.h +++ b/nest/route.h @@ -434,6 +434,9 @@ struct nexthop { struct nexthop *next; byte flags; byte weight; + byte sid6s_orig; /* Number of SRv6 SIDs before hostentry was applied */ + byte sid6s; /* Number of all SRv6 SIDs */ + ip6_addr sid6[SRV6_MAX_SID_STACK]; byte labels_orig; /* Number of labels before hostentry was applied */ byte labels; /* Number of all labels */ u32 label[0]; @@ -724,12 +727,12 @@ void rta_show(struct cli *, rta *); u32 rt_get_igp_metric(rte *rt); struct hostentry * rt_get_hostentry(rtable *tab, ip_addr a, ip_addr ll, rtable *dep); -void rta_apply_hostentry(rta *a, struct hostentry *he, mpls_label_stack *mls); +void rta_apply_hostentry(rta *a, struct hostentry *he, mpls_label_stack *mls, srv6_sid_stack *sid6); static inline void -rta_set_recursive_next_hop(rtable *dep, rta *a, rtable *tab, ip_addr gw, ip_addr ll, mpls_label_stack *mls) +rta_set_recursive_next_hop(rtable *dep, rta *a, rtable *tab, ip_addr gw, ip_addr ll, mpls_label_stack *mls, srv6_sid_stack *sid6) { - rta_apply_hostentry(a, rt_get_hostentry(tab, gw, ll, dep), mls); + rta_apply_hostentry(a, rt_get_hostentry(tab, gw, ll, dep), mls, sid6); } /* diff --git a/nest/rt-attr.c b/nest/rt-attr.c index e10e1ec..4a3366d 100644 --- a/nest/rt-attr.c +++ b/nest/rt-attr.c @@ -180,6 +180,9 @@ nexthop_hash(struct nexthop *x) for (int i = 0; i < x->labels; i++) h ^= x->label[i] ^ (h << 6) ^ (h >> 7); + + for (int i = 0; i < x->sid6s; i++) + h ^= ip6_hash(x->sid6[i]) ^ (h << 7) ^ (h >> 8); } return h; @@ -190,13 +193,18 @@ nexthop_equal_1(struct nexthop *x, struct nexthop *y) { if (!ipa_equal(x->gw, y->gw) || (x->iface != y->iface) || (x->flags != y->flags) || (x->weight != y->weight) || - (x->labels != y->labels)) + (x->labels != y->labels) || + (x->sid6s != y->sid6s)) return 0; for (int i = 0; i < x->labels; i++) if (x->label[i] != y->label[i]) return 0; + for (int i = 0; i < x->sid6s; i++) + if (memcmp(&x->sid6[i], &y->sid6[i], sizeof(x->sid6[0])) != 0) + return 0; + return 1; } @@ -217,7 +225,8 @@ nexthop__same(struct nexthop *x, struct nexthop *y) { for (; x && y; x = x->next, y = y->next) if (!nexthop_equal_1(x, y) || - (x->labels_orig != y->labels_orig)) + (x->labels_orig != y->labels_orig) || + (x->sid6s_orig != y->sid6s_orig)) return 0; return x == y; @@ -255,6 +264,17 @@ nexthop_compare_node(const struct nexthop *x, const struct nexthop *y) return r; } + r = ((int) y->sid6s) - ((int) x->sid6s); + if (r) + return r; + + for (int i = 0; i < y->sid6s; i++) + { + r = ip6_compare(x->sid6[i], y->sid6[i]); + if (r) + return r; + } + return ((int) x->iface->index) - ((int) y->iface->index); } @@ -398,6 +418,10 @@ nexthop_copy(struct nexthop *o) n->labels = o->labels; for (int i=0; ilabels; i++) n->label[i] = o->label[i]; + n->sid6s_orig = o->sid6s_orig; + n->sid6s = o->sid6s; + for (int i=0; isid6s; i++) + memcpy(&n->sid6[i], &o->sid6[i], sizeof(n->sid6[0])); *last = n; last = &(n->next); @@ -1340,6 +1364,10 @@ rta_dump(struct dump_request *dreq, rta *a) if (nh->labels) RDUMP(" L %d", nh->label[0]); for (int i=1; ilabels; i++) RDUMP("/%d", nh->label[i]); + if (nh->sid6s) RDUMP(" SRv6 <%I6", nh->sid6[0]); + for (int i=1; isid6s; i++) + RDUMP(",%I6", nh->sid6[i]); + if (nh->sid6s) RDUMP(">"); RDUMP(" [%s]", nh->iface ? nh->iface->name : "???"); } if (a->eattrs) diff --git a/nest/rt-show.c b/nest/rt-show.c index 0ecc863..c8f07ea 100644 --- a/nest/rt-show.c +++ b/nest/rt-show.c @@ -73,6 +73,7 @@ rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary for (nh = &(a->nh); nh; nh = nh->next) { char mpls[MPLS_MAX_LABEL_STRING], *lsp = mpls; + char srv6[SRV6_MAX_SID_STRING], *sid6 = srv6; char *onlink = (nh->flags & RNF_ONLINK) ? " onlink" : ""; char weight[16] = ""; @@ -84,15 +85,24 @@ rt_show_rte(struct cli *c, byte *ia, rte *e, struct rt_show_data *d, int primary } *lsp = '\0'; + if (nh->sid6s) + { + sid6 += bsprintf(sid6, " srv6 <%I6", nh->sid6[0]); + for (int i = 1; i < nh->sid6s; ++i) + sid6 += bsprintf(sid6, ",%I6", nh->sid6[i]); + sid6 += bsprintf(sid6, ">"); + } + *sid6 = '\0'; + if (a->nh.next) bsprintf(weight, " weight %d", nh->weight + 1); if (ipa_nonzero(nh->gw)) - cli_printf(c, -1007, "\tvia %I on %s%s%s%s", - nh->gw, nh->iface->name, mpls, onlink, weight); + cli_printf(c, -1007, "\tvia %I on %s%s%s%s%s", + nh->gw, nh->iface->name, mpls, srv6, onlink, weight); else - cli_printf(c, -1007, "\tdev %s%s%s", - nh->iface->name, mpls, onlink, weight); + cli_printf(c, -1007, "\tdev %s%s%s%s", + nh->iface->name, mpls, srv6, onlink, weight); } if (d->verbose) diff --git a/nest/rt-table.c b/nest/rt-table.c index ed364d3..cdcebd5 100644 --- a/nest/rt-table.c +++ b/nest/rt-table.c @@ -2391,7 +2391,7 @@ rt_postconfig(struct config *c) */ void -rta_apply_hostentry(rta *a, struct hostentry *he, mpls_label_stack *mls) +rta_apply_hostentry(rta *a, struct hostentry *he, mpls_label_stack *mls, srv6_sid_stack *sid6) { a->hostentry = he; a->dest = he->dest; @@ -2407,10 +2407,15 @@ no_nexthop: a->nh.labels_orig = a->nh.labels = mls->len; memcpy(a->nh.label, mls->stack, mls->len * sizeof(u32)); } + if (sid6) + { + a->nh.sid6s_orig = a->nh.sid6s = sid6->len; + memcpy(a->nh.sid6, sid6->sid, sid6->len * sizeof(sid6->sid[0])); + } return; } - if (((!mls) || (!mls->len)) && he->nexthop_linkable) + if ((((!mls) || (!mls->len)) && (!(sid6) || !(sid6->len))) && he->nexthop_linkable) { /* Just link the nexthop chain, no label append happens. */ memcpy(&(a->nh), &(he->src->nh), nexthop_size(&(he->src->nh))); return; @@ -2457,6 +2462,30 @@ no_nexthop: memcpy(nhp->label, nh->label, nh->labels * sizeof(u32)); } + if (sid6) + { + nhp->sid6s = nh->sid6s + sid6->len; + nhp->sid6s_orig = sid6->len; + if (nhp->sid6s <= SRV6_MAX_SID_STACK) + { + memcpy(nhp->sid6, nh->sid6, nh->sid6s * sizeof(nhp->sid6[0])); /* First the hostentry SIDs */ + memcpy(&(nhp->sid6[nh->sid6s]), sid6->sid, sid6->len * sizeof(nhp->sid6[0])); /* Then the bottom SIDs */ + } + else + { + log(L_WARN "Sum of SID stack sizes %d + %d = %d exceedes allowed maximum (%d)", + nh->sid6s, sid6->len, nhp->sid6s, SRV6_MAX_SID_STACK); + skip_nexthop++; + continue; + } + } + else if (nh->sid6s) + { + nhp->sid6s = nh->sid6s; + nhp->sid6s_orig = 0; + memcpy(nhp->sid6, nh->sid6, nhp->sid6s * sizeof(nhp->sid6[0])); + } + if (ipa_nonzero(nh->gw)) { nhp->gw = nh->gw; /* Router nexthop */ @@ -2508,7 +2537,10 @@ rt_next_hop_update_rte(rtable *tab UNUSED, rte *old) mpls_label_stack mls = { .len = a->nh.labels_orig }; memcpy(mls.stack, &a->nh.label[a->nh.labels - mls.len], mls.len * sizeof(u32)); - rta_apply_hostentry(a, old->attrs->hostentry, &mls); + srv6_sid_stack sid6 = { .len = a->nh.sid6s_orig }; + memcpy(sid6.sid, &a->nh.sid6[a->nh.sid6s - sid6.len], sid6.len * sizeof(sid6.sid[0])); + + rta_apply_hostentry(a, old->attrs->hostentry, &mls, &sid6); a->cached = 0; rte *e = sl_alloc(rte_slab); -- 2.47.3