diff options
author | Maria Matejka <mq@ucw.cz> | 2022-09-27 12:39:07 +0200 |
---|---|---|
committer | Maria Matejka <mq@ucw.cz> | 2022-09-27 12:39:07 +0200 |
commit | 32a67c93ebf29309286dca5195f026eeda3f78a2 (patch) | |
tree | 578c6038187d0c50c4a4f250e440983dbb93029d /proto/bgp/packets.c | |
parent | 57a34d466e85bedbf40a0f7cbde23b843a303c8d (diff) | |
parent | cae5979871ee7aa341334f8b1af6bafc60ee9692 (diff) |
Merge commit 'cae5979871ee7aa341334f8b1af6bafc60ee9692' into tmp-bad-learn
Diffstat (limited to 'proto/bgp/packets.c')
-rw-r--r-- | proto/bgp/packets.c | 207 |
1 files changed, 123 insertions, 84 deletions
diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c index 647551e5..9911738d 100644 --- a/proto/bgp/packets.c +++ b/proto/bgp/packets.c @@ -15,8 +15,8 @@ #include "nest/bird.h" #include "nest/iface.h" #include "nest/protocol.h" -#include "nest/route.h" -#include "nest/attrs.h" +#include "nest/rt.h" +#include "lib/attrs.h" #include "proto/mrt/mrt.h" #include "conf/conf.h" #include "lib/unaligned.h" @@ -932,11 +932,15 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, uint len) #define WITHDRAW(msg, args...) \ ({ REPORT(msg, ## args); s->err_withdraw = 1; return; }) +#define REJECT(msg, args...) \ + ({ log(L_ERR "%s: " msg, s->proto->p.name, ## args); s->err_reject = 1; return; }) + #define BAD_AFI "Unexpected AF <%u/%u> in UPDATE" #define BAD_NEXT_HOP "Invalid NEXT_HOP attribute" #define NO_NEXT_HOP "Missing NEXT_HOP attribute" #define NO_LABEL_STACK "Missing MPLS stack" +#define MISMATCHED_AF " - mismatched address family (%I for %s)" static void bgp_apply_next_hop(struct bgp_parse_state *s, rta *a, ip_addr gw, ip_addr ll) @@ -949,67 +953,86 @@ bgp_apply_next_hop(struct bgp_parse_state *s, rta *a, ip_addr gw, ip_addr ll) neighbor *nbr = NULL; /* GW_DIRECT -> single_hop -> p->neigh != NULL */ - if (ipa_nonzero(gw)) + if (ipa_nonzero2(gw)) nbr = neigh_find(&p->p, gw, NULL, 0); else if (ipa_nonzero(ll)) nbr = neigh_find(&p->p, ll, p->neigh->iface, 0); + else + WITHDRAW(BAD_NEXT_HOP " - zero address"); + + if (!nbr) + WITHDRAW(BAD_NEXT_HOP " - address %I not directly reachable", ipa_nonzero(gw) ? gw : ll); - if (!nbr || (nbr->scope == SCOPE_HOST)) - WITHDRAW(BAD_NEXT_HOP); + if (nbr->scope == SCOPE_HOST) + WITHDRAW(BAD_NEXT_HOP " - address %I is local", nbr->addr); - a->dest = RTD_UNICAST; - a->nh.gw = nbr->addr; - a->nh.iface = nbr->iface; - a->igp_metric = c->cf->cost; + ea_set_attr_u32(&a->eattrs, &ea_gen_igp_metric, 0, c->cf->cost); + + struct nexthop_adata nhad = { + .nh = { + .gw = nbr->addr, + .iface = nbr->iface, + }, + .ad = { + .length = sizeof nhad - sizeof nhad.ad, + }, + }; + ea_set_attr_data(&a->eattrs, &ea_gen_nexthop, 0, nhad.ad.data, nhad.ad.length); } else /* GW_RECURSIVE */ { - if (ipa_zero(gw)) - WITHDRAW(BAD_NEXT_HOP); + if (ipa_zero2(gw)) + WITHDRAW(BAD_NEXT_HOP " - zero address"); rtable *tab = ipa_is_ip4(gw) ? c->igp_table_ip4 : c->igp_table_ip6; - s->hostentry = rt_get_hostentry(tab, gw, ll, c->c.table); - - if (!s->mpls) - rta_apply_hostentry(a, s->hostentry, NULL); - - /* With MPLS, hostentry is applied later in bgp_apply_mpls_labels() */ + if (s->mpls) + { + u32 labels[BGP_MPLS_MAX]; + ea_set_hostentry(&a->eattrs, c->c.table, tab, gw, ll, BGP_MPLS_MAX, labels); + } + else + ea_set_hostentry(&a->eattrs, c->c.table, tab, gw, ll, 0, NULL); } } static void -bgp_apply_mpls_labels(struct bgp_parse_state *s, rta *a, u32 *labels, uint lnum) +bgp_apply_mpls_labels(struct bgp_parse_state *s, rta *a, u32 lnum, u32 labels[lnum]) { if (lnum > MPLS_MAX_LABEL_STACK) { REPORT("Too many MPLS labels ($u)", lnum); - a->dest = RTD_UNREACHABLE; - a->hostentry = NULL; - a->nh = (struct nexthop) { }; + ea_set_dest(&a->eattrs, 0, RTD_UNREACHABLE); return; } /* Handle implicit NULL as empty MPLS stack */ if ((lnum == 1) && (labels[0] == BGP_MPLS_NULL)) - lnum = 0; + lnum = s->mpls_labels->length = 0; if (s->channel->cf->gw_mode == GW_DIRECT) { - a->nh.labels = lnum; - memcpy(a->nh.label, labels, 4*lnum); + eattr *e = ea_find(a->eattrs, &ea_gen_nexthop); + struct { + struct nexthop_adata nhad; + u32 labels[MPLS_MAX_LABEL_STACK]; + } nh; + + memcpy(&nh.nhad, e->u.ptr, sizeof(struct adata) + e->u.ptr->length); + nh.nhad.nh.labels = lnum; + memcpy(nh.labels, labels, lnum * sizeof(u32)); + nh.nhad.ad.length = sizeof nh.nhad + lnum * sizeof(u32); } else /* GW_RECURSIVE */ { - mpls_label_stack ms; - - ms.len = lnum; - memcpy(ms.stack, labels, 4*lnum); - rta_apply_hostentry(a, s->hostentry, &ms); + eattr *e = ea_find(a->eattrs, &ea_gen_hostentry); + ASSERT_DIE(e); + struct hostentry_adata *head = (void *) e->u.ptr; + memcpy(&head->labels, labels, lnum * sizeof(u32)); + head->ad.length = (void *)(&head->labels[lnum]) - (void *) head->ad.data; } } - static int bgp_match_src(struct bgp_export_state *s, int mode) { @@ -1039,7 +1062,7 @@ bgp_use_next_hop(struct bgp_export_state *s, eattr *a) return 1; /* Keep it when explicitly set in export filter */ - if (a->type & EAF_FRESH) + if (a->fresh) return 1; /* Check for non-matching AF */ @@ -1056,7 +1079,7 @@ bgp_use_next_hop(struct bgp_export_state *s, eattr *a) return p->neigh && (p->neigh->iface == ifa); } -static inline int +static inline struct nexthop * bgp_use_gateway(struct bgp_export_state *s) { struct bgp_proto *p = s->proto; @@ -1065,22 +1088,32 @@ bgp_use_gateway(struct bgp_export_state *s) /* Handle next hop self option - also applies to gateway */ if (c->cf->next_hop_self && bgp_match_src(s, c->cf->next_hop_self)) - return 0; + return NULL; + + eattr *nhea = ea_find(ra->eattrs, &ea_gen_nexthop); + if (!nhea) + return NULL; /* We need one valid global gateway */ - if ((ra->dest != RTD_UNICAST) || ra->nh.next || ipa_zero(ra->nh.gw) || ipa_is_link_local(ra->nh.gw)) - return 0; + struct nexthop_adata *nhad = (struct nexthop_adata *) nhea->u.ptr; + if (!NEXTHOP_IS_REACHABLE(nhad) || + !NEXTHOP_ONE(nhad) || ipa_zero(nhad->nh.gw) || + ipa_is_link_local(nhad->nh.gw)) + return NULL; /* Check for non-matching AF */ - if ((ipa_is_ip4(ra->nh.gw) != bgp_channel_is_ipv4(c)) && !c->ext_next_hop) - return 0; + if ((ipa_is_ip4(nhad->nh.gw) != bgp_channel_is_ipv4(c)) && !c->ext_next_hop) + return NULL; /* Use it when exported to internal peers */ if (p->is_interior) - return 1; + return &nhad->nh; /* Use it when forwarded to single-hop BGP peer on on the same iface */ - return p->neigh && (p->neigh->iface == ra->nh.iface); + if (p->neigh && (p->neigh->iface == nhad->nh.iface)) + return &nhad->nh; + + return NULL; } static void @@ -1088,31 +1121,31 @@ bgp_update_next_hop_ip(struct bgp_export_state *s, eattr *a, ea_list **to) { if (!a || !bgp_use_next_hop(s, a)) { - if (bgp_use_gateway(s)) + struct nexthop *nhloc; + if (nhloc = bgp_use_gateway(s)) { - rta *ra = s->route->attrs; - ip_addr nh[1] = { ra->nh.gw }; - bgp_set_attr_data(to, s->pool, BA_NEXT_HOP, 0, nh, 16); + ip_addr nh[1] = { nhloc->gw }; + bgp_set_attr_data(to, BA_NEXT_HOP, 0, nh, 16); if (s->mpls) { u32 implicit_null = BGP_MPLS_NULL; - u32 *labels = ra->nh.labels ? ra->nh.label : &implicit_null; - uint lnum = ra->nh.labels ? ra->nh.labels : 1; - bgp_set_attr_data(to, s->pool, BA_MPLS_LABEL_STACK, 0, labels, lnum * 4); + u32 *labels = nhloc->labels ? nhloc->label : &implicit_null; + uint lnum = nhloc->labels ? nhloc->labels : 1; + bgp_set_attr_data(to, BA_MPLS_LABEL_STACK, 0, labels, lnum * 4); } } else { ip_addr nh[2] = { s->channel->next_hop_addr, s->channel->link_addr }; - bgp_set_attr_data(to, s->pool, BA_NEXT_HOP, 0, nh, ipa_nonzero(nh[1]) ? 32 : 16); + bgp_set_attr_data(to, BA_NEXT_HOP, 0, nh, ipa_nonzero(nh[1]) ? 32 : 16); s->local_next_hop = 1; /* TODO: Use local MPLS assigned label */ if (s->mpls) { u32 implicit_null = BGP_MPLS_NULL; - bgp_set_attr_data(to, s->pool, BA_MPLS_LABEL_STACK, 0, &implicit_null, 4); + bgp_set_attr_data(to, BA_MPLS_LABEL_STACK, 0, &implicit_null, 4); } } } @@ -1120,28 +1153,28 @@ bgp_update_next_hop_ip(struct bgp_export_state *s, eattr *a, ea_list **to) /* Check if next hop is valid */ a = bgp_find_attr(*to, BA_NEXT_HOP); if (!a) - WITHDRAW(NO_NEXT_HOP); + REJECT(NO_NEXT_HOP); ip_addr *nh = (void *) a->u.ptr->data; ip_addr peer = s->proto->remote_ip; uint len = a->u.ptr->length; /* Forbid zero next hop */ - if (ipa_zero(nh[0]) && ((len != 32) || ipa_zero(nh[1]))) - WITHDRAW(BAD_NEXT_HOP); + if (ipa_zero2(nh[0]) && ((len != 32) || ipa_zero(nh[1]))) + REJECT(BAD_NEXT_HOP " - zero address"); /* Forbid next hop equal to neighbor IP */ if (ipa_equal(peer, nh[0]) || ((len == 32) && ipa_equal(peer, nh[1]))) - WITHDRAW(BAD_NEXT_HOP); + REJECT(BAD_NEXT_HOP " - neighbor address %I", peer); /* Forbid next hop with non-matching AF */ if ((ipa_is_ip4(nh[0]) != bgp_channel_is_ipv4(s->channel)) && !s->channel->ext_next_hop) - WITHDRAW(BAD_NEXT_HOP); + REJECT(BAD_NEXT_HOP MISMATCHED_AF, nh[0], s->channel->desc->name); /* Just check if MPLS stack */ if (s->mpls && !bgp_find_attr(*to, BA_MPLS_LABEL_STACK)) - WITHDRAW(NO_LABEL_STACK); + REJECT(NO_LABEL_STACK); } static uint @@ -1212,11 +1245,11 @@ bgp_decode_next_hop_ip(struct bgp_parse_state *s, byte *data, uint len, rta *a) ad->length = 16; if ((bgp_channel_is_ipv4(c) != ipa_is_ip4(nh[0])) && !c->ext_next_hop) - WITHDRAW(BAD_NEXT_HOP); + WITHDRAW(BAD_NEXT_HOP MISMATCHED_AF, nh[0], c->desc->name); // XXXX validate next hop - bgp_set_attr_ptr(&(a->eattrs), s->pool, BA_NEXT_HOP, 0, ad); + bgp_set_attr_ptr(&(a->eattrs), BA_NEXT_HOP, 0, ad); bgp_apply_next_hop(s, a, nh[0], nh[1]); } @@ -1293,11 +1326,11 @@ bgp_decode_next_hop_vpn(struct bgp_parse_state *s, byte *data, uint len, rta *a) bgp_parse_error(s, 9); if ((bgp_channel_is_ipv4(c) != ipa_is_ip4(nh[0])) && !c->ext_next_hop) - WITHDRAW(BAD_NEXT_HOP); + WITHDRAW(BAD_NEXT_HOP MISMATCHED_AF, nh[0], c->desc->name); // XXXX validate next hop - bgp_set_attr_ptr(&(a->eattrs), s->pool, BA_NEXT_HOP, 0, ad); + bgp_set_attr_ptr(&(a->eattrs), BA_NEXT_HOP, 0, ad); bgp_apply_next_hop(s, a, nh[0], nh[1]); } @@ -1322,11 +1355,11 @@ bgp_decode_next_hop_none(struct bgp_parse_state *s UNUSED, byte *data UNUSED, ui } static void -bgp_update_next_hop_none(struct bgp_export_state *s, eattr *a, ea_list **to) +bgp_update_next_hop_none(struct bgp_export_state *s UNUSED, eattr *a, ea_list **to) { /* NEXT_HOP shall not pass */ if (a) - bgp_unset_attr(to, s->pool, BA_NEXT_HOP); + bgp_unset_attr(to, BA_NEXT_HOP); } @@ -1335,7 +1368,7 @@ bgp_update_next_hop_none(struct bgp_export_state *s, eattr *a, ea_list **to) */ static void -bgp_rte_update(struct bgp_parse_state *s, net_addr *n, u32 path_id, rta *a0) +bgp_rte_update(struct bgp_parse_state *s, const net_addr *n, u32 path_id, rta *a0) { if (path_id != s->last_id) { @@ -1348,6 +1381,10 @@ bgp_rte_update(struct bgp_parse_state *s, net_addr *n, u32 path_id, rta *a0) if (!a0) { + /* Route update was changed to withdraw */ + if (s->err_withdraw && s->reach_nlri_step) + REPORT("Invalid route %N withdrawn", n); + /* Route withdraw */ rte_update(&s->channel->c, n, NULL, s->last_src); return; @@ -1392,7 +1429,8 @@ bgp_encode_mpls_labels(struct bgp_write_state *s UNUSED, const adata *mpls, byte static void bgp_decode_mpls_labels(struct bgp_parse_state *s, byte **pos, uint *len, uint *pxlen, rta *a) { - u32 labels[BGP_MPLS_MAX], label; + u32 labels[BGP_MPLS_MAX]; + u32 label; uint lnum = 0; do { @@ -1406,7 +1444,7 @@ bgp_decode_mpls_labels(struct bgp_parse_state *s, byte **pos, uint *len, uint *p /* RFC 8277 2.4 - withdraw does not have variable-size MPLS stack but fixed-size 24-bit Compatibility field, which MUST be ignored */ - if (!a && !s->err_withdraw) + if (!s->reach_nlri_step) return; } while (!(label & BGP_MPLS_BOS)); @@ -1414,19 +1452,8 @@ bgp_decode_mpls_labels(struct bgp_parse_state *s, byte **pos, uint *len, uint *p if (!a) return; - /* Attach MPLS attribute unless we already have one */ - if (!s->mpls_labels) - { - s->mpls_labels = lp_alloc_adata(s->pool, 4*BGP_MPLS_MAX); - bgp_set_attr_ptr(&(a->eattrs), s->pool, BA_MPLS_LABEL_STACK, 0, s->mpls_labels); - } - - /* Overwrite data in the attribute */ - s->mpls_labels->length = 4*lnum; - memcpy(s->mpls_labels->data, labels, 4*lnum); - /* Update next hop entry in rta */ - bgp_apply_mpls_labels(s, a, labels, lnum); + bgp_apply_mpls_labels(s, a, lnum, labels); /* Attributes were changed, invalidate cached entry */ rta_free(s->cached_rta); @@ -2289,11 +2316,14 @@ bgp_create_update(struct bgp_channel *c, byte *buf) again: ; + struct lp_state tmpp; + lp_save(tmp_linpool, &tmpp); + /* Initialize write state */ struct bgp_write_state s = { .proto = p, .channel = c, - .pool = bgp_linpool, + .pool = tmp_linpool, .mp_reach = (c->afi != BGP_AF_IPV4) || c->ext_next_hop, .as4_session = p->as4_session, .add_path = c->add_path_tx, @@ -2319,6 +2349,7 @@ again: ; if (EMPTY_LIST(buck->prefixes)) { bgp_free_bucket(c, buck); + lp_restore(tmp_linpool, &tmpp); goto again; } @@ -2332,7 +2363,10 @@ again: ; bgp_defer_bucket(c, buck); if (!res) + { + lp_restore(tmp_linpool, &tmpp); goto again; + } goto done; } @@ -2343,7 +2377,7 @@ again: ; done: BGP_TRACE_RL(&rl_snd_update, D_PACKETS, "Sending UPDATE"); p->stats.tx_updates++; - lp_flush(s.pool); + lp_restore(tmp_linpool, &tmpp); return res; } @@ -2433,11 +2467,11 @@ bgp_decode_nlri(struct bgp_parse_state *s, u32 afi, byte *nlri, uint len, ea_lis { a = allocz(RTA_MAX_SIZE); - a->source = RTS_BGP; - a->scope = SCOPE_UNIVERSE; - a->from = s->proto->remote_ip; a->eattrs = ea; - a->pref = c->c.preference; + + ea_set_attr_data(&a->eattrs, &ea_gen_from, 0, &s->proto->remote_ip, sizeof(ip_addr)); + ea_set_attr_u32(&a->eattrs, &ea_gen_preference, 0, c->c.preference); + ea_set_attr_u32(&a->eattrs, &ea_gen_source, 0, RTS_BGP); c->desc->decode_next_hop(s, nh, nh_len, a); bgp_finish_attrs(s, a); @@ -2472,10 +2506,13 @@ bgp_rx_update(struct bgp_conn *conn, byte *pkt, uint len) bgp_start_timer(conn->hold_timer, conn->hold_time); + struct lp_state tmpp; + lp_save(tmp_linpool, &tmpp); + /* Initialize parse state */ struct bgp_parse_state s = { .proto = p, - .pool = bgp_linpool, + .pool = tmp_linpool, .as4_session = p->as4_session, }; @@ -2541,6 +2578,8 @@ bgp_rx_update(struct bgp_conn *conn, byte *pkt, uint len) if (s.mp_unreach_len) bgp_decode_nlri(&s, s.mp_unreach_af, s.mp_unreach_nlri, s.mp_unreach_len, NULL, NULL, 0); + s.reach_nlri_step = 1; + if (s.ip_reach_len) bgp_decode_nlri(&s, BGP_AF_IPV4, s.ip_reach_nlri, s.ip_reach_len, ea, s.ip_next_hop_data, s.ip_next_hop_len); @@ -2551,7 +2590,7 @@ bgp_rx_update(struct bgp_conn *conn, byte *pkt, uint len) done: rta_free(s.cached_rta); - lp_flush(s.pool); + lp_restore(tmp_linpool, &tmpp); return; } @@ -2695,7 +2734,7 @@ bgp_rx_route_refresh(struct bgp_conn *conn, byte *pkt, uint len) { case BGP_RR_REQUEST: BGP_TRACE(D_PACKETS, "Got ROUTE-REFRESH"); - channel_request_feeding(&c->c); + rt_refeed_channel(&c->c); break; case BGP_RR_BEGIN: |