/* * BIRD -- BGP Attributes * * (c) 2000 Martin Mares * * Can be freely distributed and used under the terms of the GNU GPL. */ #undef LOCAL_DEBUG #include #include "nest/bird.h" #include "nest/iface.h" #include "nest/protocol.h" #include "nest/route.h" #include "nest/attrs.h" #include "conf/conf.h" #include "lib/resource.h" #include "lib/string.h" #include "lib/unaligned.h" #include "bgp.h" static byte bgp_mandatory_attrs[] = { BA_ORIGIN, BA_AS_PATH #ifndef IPV6 ,BA_NEXT_HOP #endif }; struct attr_desc { char *name; int expected_length; int expected_flags; int type; int allow_in_ebgp; int (*validate)(struct bgp_proto *p, byte *attr, int len); void (*format)(eattr *ea, byte *buf); }; static int bgp_check_origin(struct bgp_proto *p, byte *a, int len) { if (len > 2) return 6; return 0; } static void bgp_format_origin(eattr *a, byte *buf) { static char *bgp_origin_names[] = { "IGP", "EGP", "Incomplete" }; bsprintf(buf, bgp_origin_names[a->u.data]); } static int bgp_check_path(struct bgp_proto *p, byte *a, int len) { while (len) { DBG("Path segment %02x %02x\n", a[0], a[1]); if (len < 2 || a[0] != AS_PATH_SET && a[0] != AS_PATH_SEQUENCE || 2*a[1] + 2 > len) return 11; len -= 2*a[1] + 2; a += 2*a[1] + 2; } return 0; } static int bgp_check_next_hop(struct bgp_proto *p, byte *a, int len) { #ifdef IPV6 return -1; #else ip_addr addr; memcpy(&addr, a, len); ipa_ntoh(addr); if (ipa_classify(addr) & IADDR_HOST) return 0; else return 8; #endif } static int bgp_check_reach_nlri(struct bgp_proto *p, byte *a, int len) { #ifdef IPV6 p->mp_reach_start = a; p->mp_reach_len = len; return 0; #else return -1; #endif } static int bgp_check_unreach_nlri(struct bgp_proto *p, byte *a, int len) { #ifdef IPV6 p->mp_unreach_start = a; p->mp_unreach_len = len; return 0; #else return -1; #endif } static struct attr_desc bgp_attr_table[] = { { NULL, -1, 0, 0, 0, /* Undefined */ NULL, NULL }, { "origin", 1, BAF_TRANSITIVE, EAF_TYPE_INT, 1, /* BA_ORIGIN */ bgp_check_origin, bgp_format_origin }, { "as_path", -1, BAF_TRANSITIVE, EAF_TYPE_AS_PATH, 1, /* BA_AS_PATH */ bgp_check_path, NULL }, { "next_hop", 4, BAF_TRANSITIVE, EAF_TYPE_IP_ADDRESS, 1, /* BA_NEXT_HOP */ bgp_check_next_hop, NULL }, { "med", 4, BAF_OPTIONAL, EAF_TYPE_INT, 0, /* BA_MULTI_EXIT_DISC */ NULL, NULL }, { "local_pref", 4, BAF_OPTIONAL, EAF_TYPE_INT, 0, /* BA_LOCAL_PREF */ NULL, NULL }, { "atomic_aggr", 0, BAF_TRANSITIVE, EAF_TYPE_OPAQUE, 1, /* BA_ATOMIC_AGGR */ NULL, NULL }, { "aggregator", 6, BAF_OPTIONAL | BAF_TRANSITIVE, EAF_TYPE_OPAQUE, 1, /* BA_AGGREGATOR */ NULL, NULL }, { "community", -1, BAF_OPTIONAL | BAF_TRANSITIVE, EAF_TYPE_INT_SET, 1, /* BA_COMMUNITY */ NULL, NULL }, { NULL, }, /* BA_ORIGINATOR_ID */ { NULL, }, /* BA_CLUSTER_LIST */ { NULL, }, /* BA_DPA */ { NULL, }, /* BA_ADVERTISER */ { NULL, }, /* BA_RCID_PATH */ { "mp_reach_nlri", -1, BAF_OPTIONAL, EAF_TYPE_OPAQUE, 1, /* BA_MP_REACH_NLRI */ bgp_check_reach_nlri, NULL }, { "mp_unreach_nlri", -1, BAF_OPTIONAL, EAF_TYPE_OPAQUE, 1, /* BA_MP_UNREACH_NLRI */ bgp_check_unreach_nlri, NULL }, }; #define ATTR_KNOWN(code) ((code) < ARRAY_SIZE(bgp_attr_table) && bgp_attr_table[code].name) byte * bgp_encode_attrs(byte *w, struct bgp_bucket *buck) { int remains = 1024; unsigned int i, code, flags; byte *start = w; int len; w += 2; for(i=0; ieattrs->count; i++) { eattr *a = &buck->eattrs->attrs[i]; ASSERT(EA_PROTO(a->id) == EAP_BGP); code = EA_ID(a->id); flags = a->flags & (BAF_OPTIONAL | BAF_TRANSITIVE | BAF_PARTIAL); if (ATTR_KNOWN(code)) { struct attr_desc *desc = &bgp_attr_table[code]; len = desc->expected_length; if (len < 0) { ASSERT(!(a->type & EAF_EMBEDDED)); len = a->u.ptr->length; } } else { ASSERT((a->type & EAF_TYPE_MASK) == EAF_TYPE_OPAQUE); len = a->u.ptr->length; } DBG("\tAttribute %02x (type %02x, %d bytes, flags %02x)\n", code, a->type, len, flags); if (remains < len + 4) { log(L_ERR "BGP: attribute list too long, ignoring the remaining attributes"); break; } if (len < 256) { *w++ = flags; *w++ = code; *w++ = len; remains -= 3; } else { *w++ = flags | BAF_EXT_LEN; *w++ = code; put_u16(w, len); w += 2; remains -= 4; } switch (a->type & EAF_TYPE_MASK) { case EAF_TYPE_INT: case EAF_TYPE_ROUTER_ID: if (len == 4) put_u32(w, a->u.data); else *w = a->u.data; break; case EAF_TYPE_IP_ADDRESS: { ip_addr ip = *(ip_addr *)a->u.ptr->data; ipa_hton(ip); memcpy(w, &ip, len); break; } case EAF_TYPE_INT_SET: { u32 *z = (u32 *)a->u.ptr->data; int i; for(i=0; iu.ptr->data, len); break; default: bug("bgp_encode_attrs: unknown attribute type %02x", a->type); } remains -= len; w += len; } put_u16(start, w-start-2); return w; } static void bgp_init_prefix(struct fib_node *N) { struct bgp_prefix *p = (struct bgp_prefix *) N; p->bucket_node.next = NULL; } static int bgp_compare_u32(const u32 *x, const u32 *y) { return (*x < *y) ? -1 : (*x > *y) ? 1 : 0; } static void bgp_normalize_set(u32 *dest, u32 *src, unsigned cnt) { memcpy(dest, src, sizeof(u32) * cnt); qsort(dest, cnt, sizeof(u32), (int(*)(const void *, const void *)) bgp_compare_u32); } static void bgp_rehash_buckets(struct bgp_proto *p) { struct bgp_bucket **old = p->bucket_hash; struct bgp_bucket **new; unsigned oldn = p->hash_size; unsigned i, e, mask; struct bgp_bucket *b; p->hash_size = p->hash_limit; DBG("BGP: Rehashing bucket table from %d to %d\n", oldn, p->hash_size); p->hash_limit *= 4; if (p->hash_limit >= 65536) p->hash_limit = ~0; new = p->bucket_hash = mb_allocz(p->p.pool, p->hash_size * sizeof(struct bgp_bucket *)); mask = p->hash_size - 1; for (i=0; ihash_next; e = b->hash & mask; b->hash_next = new[e]; if (b->hash_next) b->hash_next->hash_prev = b; b->hash_prev = NULL; new[e] = b; } mb_free(old); } static struct bgp_bucket * bgp_new_bucket(struct bgp_proto *p, ea_list *new, unsigned hash) { struct bgp_bucket *b; unsigned ea_size = sizeof(ea_list) + new->count * sizeof(eattr); unsigned ea_size_aligned = ALIGN(ea_size, CPU_STRUCT_ALIGN); unsigned size = sizeof(struct bgp_bucket) + ea_size; unsigned i; byte *dest; unsigned index = hash & (p->hash_size - 1); /* Gather total size of non-inline attributes */ for (i=0; icount; i++) { eattr *a = &new->attrs[i]; if (!(a->type & EAF_EMBEDDED)) size += ALIGN(sizeof(struct adata) + a->u.ptr->length, CPU_STRUCT_ALIGN); } /* Create the bucket and hash it */ b = mb_alloc(p->p.pool, size); b->hash_next = p->bucket_hash[index]; if (b->hash_next) b->hash_next->hash_prev = b; p->bucket_hash[index] = b; b->hash_prev = NULL; b->hash = hash; add_tail(&p->bucket_queue, &b->send_node); init_list(&b->prefixes); memcpy(b->eattrs, new, ea_size); dest = ((byte *)b->eattrs) + ea_size_aligned; /* Copy values of non-inline attributes */ for (i=0; icount; i++) { eattr *a = &b->eattrs->attrs[i]; if (!(a->type & EAF_EMBEDDED)) { struct adata *oa = a->u.ptr; struct adata *na = (struct adata *) dest; memcpy(na, oa, sizeof(struct adata) + oa->length); a->u.ptr = na; dest += ALIGN(sizeof(struct adata) + na->length, CPU_STRUCT_ALIGN); } } /* If needed, rehash */ p->hash_count++; if (p->hash_count > p->hash_limit) bgp_rehash_buckets(p); return b; } static int bgp_export_check(struct bgp_proto *p, ea_list *new) { eattr *a; struct adata *d; /* Check if next hop is valid */ a = ea_find(new, EA_CODE(EAP_BGP, BA_NEXT_HOP)); if (!a || ipa_equal(p->next_hop, *(ip_addr *)a->u.ptr)) { DBG("\tInvalid NEXT_HOP\n"); return 0; } /* Check if we aren't forbidden to export the route by communities */ a = ea_find(new, EA_CODE(EAP_BGP, BA_COMMUNITY)); if (a) { d = a->u.ptr; if (int_set_contains(d, BGP_COMM_NO_ADVERTISE)) { DBG("\tNO_ADVERTISE\n"); return 0; } if (!p->is_internal && (int_set_contains(d, BGP_COMM_NO_EXPORT) || int_set_contains(d, BGP_COMM_NO_EXPORT_SUBCONFED))) { DBG("\tNO_EXPORT\n"); return 0; } } return 1; } static struct bgp_bucket * bgp_get_bucket(struct bgp_proto *p, ea_list *old, ea_list *tmp, int originate) { ea_list *t, *new; unsigned i, cnt, hash, code; eattr *a, *d; u32 seen = 0; struct bgp_bucket *b; /* Merge the attribute lists */ if (tmp) { for(t=tmp; t->next; t=t->next) ; t->next = old; new = alloca(ea_scan(tmp)); ea_merge(tmp, new); t->next = NULL; } else { new = alloca(ea_scan(old)); ea_merge(old, new); } ea_sort(new); /* Normalize attributes */ d = new->attrs; cnt = new->count; new->count = 0; for(i=0; iattrs[i]; #ifdef LOCAL_DEBUG { byte buf[EA_FORMAT_BUF_SIZE]; ea_format(a, buf); DBG("\t%s\n", buf); } #endif if (EA_PROTO(a->id) != EAP_BGP) continue; code = EA_ID(a->id); if (ATTR_KNOWN(code)) { if (!bgp_attr_table[code].allow_in_ebgp && !p->is_internal) continue; /* The flags might have been zero if the attr was added by filters */ a->flags = (a->flags & BAF_PARTIAL) | bgp_attr_table[code].expected_flags; if (code < 32) seen |= 1 << code; } else { /* Don't re-export unknown non-transitive attributes */ if (!(a->flags & BAF_TRANSITIVE)) continue; } *d = *a; if ((d->type & EAF_ORIGINATED) && !originate && (d->flags & BAF_TRANSITIVE) && (d->flags & BAF_OPTIONAL)) d->flags |= BAF_PARTIAL; switch (d->type & EAF_TYPE_MASK) { case EAF_TYPE_INT_SET: { struct adata *z = alloca(sizeof(struct adata) + d->u.ptr->length); z->length = d->u.ptr->length; bgp_normalize_set((u32 *) z->data, (u32 *) d->u.ptr->data, z->length / 4); d->u.ptr = z; break; } default: } d++; new->count++; } /* Hash */ hash = ea_hash(new); for(b=p->bucket_hash[hash & (p->hash_size - 1)]; b; b=b->hash_next) if (b->hash == hash && ea_same(b->eattrs, new)) { DBG("Found bucket.\n"); return b; } /* Ensure that there are all mandatory attributes */ for(i=0; ip.name, bgp_attr_table[bgp_mandatory_attrs[i]].name); return NULL; } if (!bgp_export_check(p, new)) return NULL; /* Create new bucket */ DBG("Creating bucket.\n"); return bgp_new_bucket(p, new, hash); } void bgp_free_bucket(struct bgp_proto *p, struct bgp_bucket *buck) { if (buck->hash_next) buck->hash_next->hash_prev = buck->hash_prev; if (buck->hash_prev) buck->hash_prev->hash_next = buck->hash_next; else p->bucket_hash[buck->hash & (p->hash_size-1)] = buck->hash_next; mb_free(buck); } void bgp_rt_notify(struct proto *P, net *n, rte *new, rte *old, ea_list *tmpa) { struct bgp_proto *p = (struct bgp_proto *) P; struct bgp_bucket *buck; struct bgp_prefix *px; DBG("BGP: Got route %I/%d %s\n", n->n.prefix, n->n.pxlen, new ? "up" : "down"); if (new) { buck = bgp_get_bucket(p, new->attrs->eattrs, tmpa, new->attrs->source != RTS_BGP); if (!buck) /* Inconsistent attribute list */ return; } else { if (!(buck = p->withdraw_bucket)) { buck = p->withdraw_bucket = mb_alloc(P->pool, sizeof(struct bgp_bucket)); init_list(&buck->prefixes); } } px = fib_get(&p->prefix_fib, &n->n.prefix, n->n.pxlen); if (px->bucket_node.next) { DBG("\tRemoving old entry.\n"); rem_node(&px->bucket_node); } add_tail(&buck->prefixes, &px->bucket_node); bgp_schedule_packet(p->conn, PKT_UPDATE); } static int bgp_create_attrs(struct bgp_proto *p, rte *e, ea_list **attrs, struct linpool *pool) { ea_list *ea = lp_alloc(pool, sizeof(ea_list) + 4*sizeof(eattr)); eattr *a = ea->attrs; rta *rta = e->attrs; ea->next = *attrs; *attrs = ea; ea->flags = EALF_SORTED; ea->count = 4; a->id = EA_CODE(EAP_BGP, BA_ORIGIN); a->flags = BAF_TRANSITIVE; a->type = EAF_TYPE_INT; if (rta->source == RTS_RIP_EXT || rta->source == RTS_OSPF_EXT) a->u.data = ORIGIN_INCOMPLETE; else a->u.data = ORIGIN_IGP; a++; a->id = EA_CODE(EAP_BGP, BA_AS_PATH); a->flags = BAF_TRANSITIVE; a->type = EAF_TYPE_AS_PATH; if (p->is_internal) { a->u.ptr = lp_alloc(pool, sizeof(struct adata)); a->u.ptr->length = 0; } else { byte *z; a->u.ptr = lp_alloc(pool, sizeof(struct adata) + 4); a->u.ptr->length = 4; z = a->u.ptr->data; z[0] = AS_PATH_SEQUENCE; z[1] = 1; /* 1 AS */ put_u16(z+2, p->local_as); } a++; a->id = EA_CODE(EAP_BGP, BA_NEXT_HOP); a->flags = BAF_TRANSITIVE; a->type = EAF_TYPE_IP_ADDRESS; a->u.ptr = lp_alloc(pool, sizeof(struct adata) + sizeof(ip_addr)); a->u.ptr->length = sizeof(ip_addr); if (p->cf->next_hop_self || !p->is_internal || rta->dest != RTD_ROUTER) *(ip_addr *)a->u.ptr->data = p->local_addr; else *(ip_addr *)a->u.ptr->data = e->attrs->gw; a++; a->id = EA_CODE(EAP_BGP, BA_LOCAL_PREF); a->flags = BAF_OPTIONAL; a->type = EAF_TYPE_INT; a->u.data = 0; return 0; /* Leave decision to the filters */ } static ea_list * bgp_path_prepend(struct linpool *pool, eattr *a, ea_list *old, int as) { struct ea_list *e = lp_alloc(pool, sizeof(ea_list) + sizeof(eattr)); struct adata *olda = a->u.ptr; e->next = old; e->flags = EALF_SORTED; e->count = 1; e->attrs[0].id = EA_CODE(EAP_BGP, BA_AS_PATH); e->attrs[0].flags = BAF_TRANSITIVE; e->attrs[0].type = EAF_TYPE_AS_PATH; e->attrs[0].u.ptr = as_path_prepend(pool, olda, as); return e; } static int bgp_update_attrs(struct bgp_proto *p, rte *e, ea_list **attrs, struct linpool *pool) { eattr *a; if (!p->is_internal) *attrs = bgp_path_prepend(pool, ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)), *attrs, p->local_as); a = ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_NEXT_HOP)); if (a && (p->is_internal || (!p->is_internal && e->attrs->iface == p->neigh->iface))) { /* Leave the original next hop attribute, will check later where does it point */ } else { /* Need to create new one */ ea_list *ea = lp_alloc(pool, sizeof(ea_list) + sizeof(eattr)); ea->next = *attrs; *attrs = ea; ea->flags = EALF_SORTED; ea->count = 1; a = ea->attrs; a->id = EA_CODE(EAP_BGP, BA_NEXT_HOP); a->flags = BAF_TRANSITIVE; a->type = EAF_TYPE_IP_ADDRESS; a->u.ptr = lp_alloc(pool, sizeof(struct adata) + sizeof(ip_addr)); a->u.ptr->length = sizeof(ip_addr); *(ip_addr *)a->u.ptr->data = p->local_addr; } return 0; /* Leave decision to the filters */ } int bgp_import_control(struct proto *P, rte **new, ea_list **attrs, struct linpool *pool) { rte *e = *new; struct bgp_proto *p = (struct bgp_proto *) P; struct bgp_proto *new_bgp = (e->attrs->proto->proto == &proto_bgp) ? (struct bgp_proto *) e->attrs->proto : NULL; if (p == new_bgp) /* Poison reverse updates */ return -1; if (new_bgp) { if (p->local_as == new_bgp->local_as && p->is_internal && new_bgp->is_internal) return -1; /* Don't redistribute internal routes with IBGP */ return bgp_update_attrs(p, e, attrs, pool); } else return bgp_create_attrs(p, e, attrs, pool); } int bgp_rte_better(rte *new, rte *old) { struct bgp_proto *new_bgp = (struct bgp_proto *) new->attrs->proto; struct bgp_proto *old_bgp = (struct bgp_proto *) old->attrs->proto; eattr *x, *y; u32 n, o; /* Start with local preferences */ x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_LOCAL_PREF)); y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_LOCAL_PREF)); n = x ? x->u.data : new_bgp->cf->default_local_pref; o = y ? y->u.data : old_bgp->cf->default_local_pref; if (n > o) return 1; if (n < o) return 0; /* Use AS path lengths */ if (new_bgp->cf->compare_path_lengths || old_bgp->cf->compare_path_lengths) { x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)); y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)); n = x ? as_path_getlen(x->u.ptr) : 100000; o = y ? as_path_getlen(y->u.ptr) : 100000; if (n < o) return 1; if (n > o) return 0; } /* Use origins */ x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_ORIGIN)); y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_ORIGIN)); n = x ? x->u.data : ORIGIN_INCOMPLETE; o = y ? y->u.data : ORIGIN_INCOMPLETE; if (n < o) return 1; if (n > o) return 0; /* Compare MED's */ x = ea_find(new->attrs->eattrs, EA_CODE(EAP_BGP, BA_MULTI_EXIT_DISC)); y = ea_find(old->attrs->eattrs, EA_CODE(EAP_BGP, BA_MULTI_EXIT_DISC)); n = x ? x->u.data : new_bgp->cf->default_med; o = y ? y->u.data : old_bgp->cf->default_med; if (n < o) return 1; if (n > o) return 0; /* A tie breaking procedure according to RFC 1771, section 9.1.2.1 */ /* We don't have interior distances */ /* We prefer external peers */ if (new_bgp->is_internal > old_bgp->is_internal) return 0; if (new_bgp->is_internal < old_bgp->is_internal) return 1; /* Finally we compare BGP identifiers */ return (new_bgp->remote_id < old_bgp->remote_id); } static int bgp_path_loopy(struct bgp_proto *p, eattr *a) { byte *path = a->u.ptr->data; int len = a->u.ptr->length; int i, n; while (len > 0) { n = path[1]; len -= 2 + 2*n; path += 2; for(i=0; ilocal_as) return 1; path += 2; } } return 0; } struct rta * bgp_decode_attrs(struct bgp_conn *conn, byte *attr, unsigned int len, struct linpool *pool, int mandatory) { struct bgp_proto *bgp = conn->bgp; rta *a = lp_alloc(pool, sizeof(struct rta)); unsigned int flags, code, l, i, type; int errcode; byte *z, *attr_start; byte seen[256/8]; eattr *e; ea_list *ea; struct adata *ad; a->proto = &bgp->p; a->source = RTS_BGP; a->scope = SCOPE_UNIVERSE; a->cast = RTC_UNICAST; a->dest = RTD_ROUTER; a->flags = 0; a->aflags = 0; a->from = bgp->cf->remote_ip; a->eattrs = NULL; /* Parse the attributes */ bzero(seen, sizeof(seen)); DBG("BGP: Parsing attributes\n"); while (len) { if (len < 2) goto malformed; attr_start = attr; flags = *attr++; code = *attr++; len -= 2; if (flags & BAF_EXT_LEN) { if (len < 2) goto malformed; l = get_u16(attr); attr += 2; len -= 2; } else { if (len < 1) goto malformed; l = *attr++; len--; } if (l > len) goto malformed; len -= l; z = attr; attr += l; DBG("Attr %02x %02x %d\n", code, flags, l); if (seen[code/8] & (1 << (code%8))) goto malformed; if (ATTR_KNOWN(code)) { struct attr_desc *desc = &bgp_attr_table[code]; if (desc->expected_length >= 0 && desc->expected_length != (int) l) { errcode = 5; goto err; } if ((desc->expected_flags ^ flags) & (BAF_OPTIONAL | BAF_TRANSITIVE)) { errcode = 4; goto err; } if (!desc->allow_in_ebgp && !bgp->is_internal) continue; if (desc->validate) { errcode = desc->validate(bgp, z, l); if (errcode > 0) goto err; if (errcode < 0) continue; } type = desc->type; } else /* Unknown attribute */ { if (!(flags & BAF_OPTIONAL)) { errcode = 2; goto err; } type = EAF_TYPE_OPAQUE; } seen[code/8] |= (1 << (code%8)); ea = lp_alloc(pool, sizeof(ea_list) + sizeof(eattr)); ea->next = a->eattrs; a->eattrs = ea; ea->flags = 0; ea->count = 1; ea->attrs[0].id = EA_CODE(EAP_BGP, code); ea->attrs[0].flags = flags; ea->attrs[0].type = type; if (type & EAF_EMBEDDED) ad = NULL; else { ad = lp_alloc(pool, sizeof(struct adata) + l); ea->attrs[0].u.ptr = ad; ad->length = l; memcpy(ad->data, z, l); } switch (type) { case EAF_TYPE_ROUTER_ID: case EAF_TYPE_INT: if (l == 1) ea->attrs[0].u.data = *z; else ea->attrs[0].u.data = get_u32(z); break; case EAF_TYPE_IP_ADDRESS: ipa_ntoh(*(ip_addr *)ad->data); break; case EAF_TYPE_INT_SET: { u32 *z = (u32 *) ad->data; for(i=0; ilength/4; i++) z[i] = ntohl(z[i]); break; } } } #ifdef IPV6 if (seen[BA_MP_REACH_NLRI / 8] & (1 << (BA_MP_REACH_NLRI % 8))) mandatory = 1; #endif /* Check if all mandatory attributes are present */ if (mandatory) { for(i=0; i < ARRAY_SIZE(bgp_mandatory_attrs); i++) { code = bgp_mandatory_attrs[i]; if (!(seen[code/8] & (1 << (code%8)))) { bgp_error(conn, 3, 3, &bgp_mandatory_attrs[i], 1); return NULL; } } } /* If the AS path attribute contains our AS, reject the routes */ e = ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_AS_PATH)); if (e && bgp_path_loopy(bgp, e)) { DBG("BGP: Path loop!\n"); return NULL; } /* If there's no local preference, define one */ if (!(seen[0] && (1 << BA_LOCAL_PREF))) { ea = lp_alloc(pool, sizeof(ea_list) + sizeof(eattr)); ea->next = a->eattrs; a->eattrs = ea; ea->flags = 0; ea->count = 1; ea->attrs[0].id = EA_CODE(EAP_BGP, BA_LOCAL_PREF); ea->attrs[0].flags = BAF_OPTIONAL; ea->attrs[0].type = EAF_TYPE_INT; ea->attrs[0].u.data = 0; } return a; malformed: bgp_error(conn, 3, 1, NULL, 0); return NULL; err: bgp_error(conn, 3, errcode, z-2, l+2); return NULL; } int bgp_get_attr(eattr *a, byte *buf) { unsigned int i = EA_ID(a->id); struct attr_desc *d; if (ATTR_KNOWN(i)) { d = &bgp_attr_table[i]; buf += bsprintf(buf, "%s", d->name); if (d->format) { *buf++ = ':'; *buf++ = ' '; d->format(a, buf); return GA_FULL; } return GA_NAME; } bsprintf(buf, "%02x%s", i, (a->flags & BAF_TRANSITIVE) ? " [t]" : ""); return GA_NAME; } void bgp_attr_init(struct bgp_proto *p) { p->hash_size = 256; p->hash_limit = p->hash_size * 4; p->bucket_hash = mb_allocz(p->p.pool, p->hash_size * sizeof(struct bgp_bucket *)); init_list(&p->bucket_queue); p->withdraw_bucket = NULL; fib_init(&p->prefix_fib, p->p.pool, sizeof(struct bgp_prefix), 0, bgp_init_prefix); }