diff options
| -rw-r--r-- | proto/bgp/attrs.c | 291 | ||||
| -rw-r--r-- | proto/bgp/bgp.h | 4 | ||||
| -rw-r--r-- | proto/bgp/packets.c | 69 |
3 files changed, 274 insertions, 90 deletions
diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c index 6d4fd9c..bc3de3b 100644 --- a/proto/bgp/attrs.c +++ b/proto/bgp/attrs.c @@ -31,13 +31,172 @@ struct attr_desc { void (*format)(eattr *ea, byte *buf); }; -extern struct attr_desc bgp_attr_table[]; +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] != BGP_PATH_AS_SET && a[0] != BGP_PATH_AS_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) +{ + ip_addr addr; + + memcpy(&addr, a, len); + ipa_ntoh(addr); + if (ipa_classify(addr) & IADDR_HOST) + return 0; + else + return 8; +} + +static int +bgp_check_local_pref(struct bgp_proto *p, byte *a, int len) +{ + if (!p->is_internal) /* Ignore local preference from EBGP connections */ + return -1; + return 0; +} + +static struct attr_desc bgp_attr_table[] = { + { NULL, -1, 0, 0, /* Undefined */ + NULL, NULL }, + { "origin", 1, BAF_TRANSITIVE, EAF_TYPE_INT, /* BA_ORIGIN */ + bgp_check_origin, bgp_format_origin }, + { "as_path", -1, BAF_TRANSITIVE, EAF_TYPE_AS_PATH, /* BA_AS_PATH */ + bgp_check_path, NULL }, + { "next_hop", 4, BAF_TRANSITIVE, EAF_TYPE_IP_ADDRESS, /* BA_NEXT_HOP */ + bgp_check_next_hop, NULL }, + { "MED", 4, BAF_OPTIONAL, EAF_TYPE_INT, /* BA_MULTI_EXIT_DISC */ + NULL, NULL }, + { "local_pref", 4, BAF_OPTIONAL, EAF_TYPE_INT, /* BA_LOCAL_PREF */ + bgp_check_local_pref, NULL }, + { "atomic_aggr", 0, BAF_OPTIONAL, EAF_TYPE_OPAQUE, /* BA_ATOMIC_AGGR */ + NULL, NULL }, + { "aggregator", 6, BAF_OPTIONAL, EAF_TYPE_OPAQUE, /* BA_AGGREGATOR */ + NULL, NULL }, +#if 0 + /* FIXME: Handle community lists and remember to convert their endianity and normalize them */ + { 0, 0 }, /* BA_COMMUNITY */ + { 0, 0 }, /* BA_ORIGINATOR_ID */ + { 0, 0 }, /* BA_CLUSTER_LIST */ +#endif +}; + +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; i<buck->eattrs->count; i++) + { + eattr *a = &buck->eattrs->attrs[i]; + ASSERT(EA_PROTO(a->id) == EAP_BGP); + code = EA_ID(a->id); + if (code && code < ARRAY_SIZE(bgp_attr_table)) + { + 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)\n", code, a->type, len); + /* FIXME: Partial bit for locally added transitive attributes */ + if (remains < len + 4) + { + log(L_ERR "BGP: attribute list too long, ignoring the remaining attributes"); + break; + } + flags = a->flags & (BAF_OPTIONAL | BAF_TRANSITIVE | BAF_PARTIAL); + 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_OPAQUE: + case EAF_TYPE_AS_PATH: + case EAF_TYPE_INT_SET: + memcpy(w, a->u.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; - /* FIXME */ + p->bucket_node.next = NULL; } static void @@ -104,6 +263,8 @@ bgp_new_bucket(struct bgp_proto *p, ea_list *new, unsigned hash) 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; @@ -169,7 +330,7 @@ bgp_get_bucket(struct bgp_proto *p, ea_list *old, ea_list *tmp) *d = *a; switch (d->type & EAF_TYPE_MASK) { - case EAF_TYPE_INT_SET: + case EAF_TYPE_INT_SET: /* FIXME: Normalize the other attributes? */ { struct adata *z = alloca(sizeof(struct adata) + d->u.ptr->length); z->length = d->u.ptr->length; @@ -200,27 +361,60 @@ bgp_get_bucket(struct bgp_proto *p, ea_list *old, ea_list *tmp) return NULL; } + /* Check if next hop is valid */ + a = ea_find(new, EA_CODE(EAP_BGP, BA_NEXT_HOP)); + ASSERT(a); + if (ipa_equal(p->next_hop, *(ip_addr *)a->u.ptr)) + 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\n", n->n.prefix, n->n.pxlen); + DBG("BGP: Got route %I/%d %s\n", n->n.prefix, n->n.pxlen, new ? "up" : "down"); if (new) { - struct bgp_bucket *buck = bgp_get_bucket(p, new->attrs->eattrs, tmpa); + buck = bgp_get_bucket(p, new->attrs->eattrs, tmpa); if (!buck) /* Inconsistent attribute list */ return; } - - /* FIXME: Normalize attributes */ - /* FIXME: Check next hop */ + 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 @@ -404,83 +598,6 @@ bgp_path_loopy(struct bgp_proto *p, eattr *a) return 0; } -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] != BGP_PATH_AS_SET && a[0] != BGP_PATH_AS_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) -{ - ip_addr addr; - - memcpy(&addr, a, len); - if (ipa_classify(ipa_ntoh(addr)) & IADDR_HOST) - return 0; - else - return 8; -} - -static int -bgp_check_local_pref(struct bgp_proto *p, byte *a, int len) -{ - if (!p->is_internal) /* Ignore local preference from EBGP connections */ - return -1; - return 0; -} - -static struct attr_desc bgp_attr_table[] = { - { NULL, -1, 0, 0, /* Undefined */ - NULL, NULL }, - { "origin", 1, BAF_TRANSITIVE, EAF_TYPE_INT, /* BA_ORIGIN */ - bgp_check_origin, bgp_format_origin }, - { "as_path", -1, BAF_TRANSITIVE, EAF_TYPE_AS_PATH, /* BA_AS_PATH */ - bgp_check_path, NULL }, - { "next_hop", 4, BAF_TRANSITIVE, EAF_TYPE_IP_ADDRESS, /* BA_NEXT_HOP */ - bgp_check_next_hop, NULL }, - { "MED", 4, BAF_OPTIONAL, EAF_TYPE_INT, /* BA_MULTI_EXIT_DISC */ - NULL, NULL }, - { "local_pref", 4, BAF_OPTIONAL, EAF_TYPE_INT, /* BA_LOCAL_PREF */ - bgp_check_local_pref, NULL }, - { "atomic_aggr", 0, BAF_OPTIONAL, EAF_TYPE_OPAQUE, /* BA_ATOMIC_AGGR */ - NULL, NULL }, - { "aggregator", 6, BAF_OPTIONAL, EAF_TYPE_OPAQUE, /* BA_AGGREGATOR */ - NULL, NULL }, -#if 0 - /* FIXME: Handle community lists and remember to convert their endianity and normalize them */ - { 0, 0 }, /* BA_COMMUNITY */ - { 0, 0 }, /* BA_ORIGINATOR_ID */ - { 0, 0 }, /* BA_CLUSTER_LIST */ -#endif -}; - struct rta * bgp_decode_attrs(struct bgp_conn *conn, byte *attr, unsigned int len, struct linpool *pool) { @@ -540,7 +657,7 @@ bgp_decode_attrs(struct bgp_conn *conn, byte *attr, unsigned int len, struct lin DBG("Attr %02x %02x %d\n", code, flags, l); if (seen[code/8] & (1 << (code%8))) goto malformed; - if (code && code < sizeof(bgp_attr_table)/sizeof(bgp_attr_table[0])) + if (code && code < ARRAY_SIZE(bgp_attr_table)) { struct attr_desc *desc = &bgp_attr_table[code]; if (desc->expected_length >= 0 && desc->expected_length != (int) l) @@ -591,7 +708,7 @@ bgp_decode_attrs(struct bgp_conn *conn, byte *attr, unsigned int len, struct lin ea->attrs[0].u.data = get_u32(z); break; case EAF_TYPE_IP_ADDRESS: - *(ip_addr *)ad->data = ipa_ntoh(*(ip_addr *)ad->data); + ipa_ntoh(*(ip_addr *)ad->data); break; } } diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h index 9ee5b41..0f84c3b 100644 --- a/proto/bgp/bgp.h +++ b/proto/bgp/bgp.h @@ -68,8 +68,8 @@ struct bgp_prefix { }; struct bgp_bucket { - struct bgp_bucket *hash_next, *hash_prev; /* Node in bucket hash table */ node send_node; /* Node in send queue */ + struct bgp_bucket *hash_next, *hash_prev; /* Node in bucket hash table */ unsigned hash; /* Hash over extended attributes */ list prefixes; /* Prefixes in this buckets */ ea_list eattrs[0]; /* Per-bucket extended attributes */ @@ -97,6 +97,8 @@ int bgp_rte_better(struct rte *, struct rte *); void bgp_rt_notify(struct proto *, struct network *, struct rte *, struct rte *, struct ea_list *); int bgp_import_control(struct proto *, struct rte **, struct ea_list **, struct linpool *); void bgp_attr_init(struct bgp_proto *); +byte *bgp_encode_attrs(byte *w, struct bgp_bucket *buck); +void bgp_free_bucket(struct bgp_proto *p, struct bgp_bucket *buck); /* packets.c */ diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c index e85d5c0..2f3f8ad 100644 --- a/proto/bgp/packets.c +++ b/proto/bgp/packets.c @@ -46,12 +46,76 @@ bgp_create_open(struct bgp_conn *conn, byte *buf) return buf+10; } +static unsigned int +bgp_encode_prefixes(struct bgp_proto *p, byte *w, struct bgp_bucket *buck, unsigned int remains) +{ + byte *start = w; + ip_addr a; + int bytes; + + while (!EMPTY_LIST(buck->prefixes) && remains >= 5) + { + struct bgp_prefix *px = SKIP_BACK(struct bgp_prefix, bucket_node, HEAD(buck->prefixes)); + DBG("\tDequeued route %I/%d\n", px->n.prefix, px->n.pxlen); + *w++ = px->n.pxlen; + bytes = (px->n.pxlen + 7) / 8; + a = px->n.prefix; + ipa_hton(a); + memcpy(w, &a, bytes); + w += bytes; + rem_node(&px->bucket_node); + fib_delete(&p->prefix_fib, px); + } + return w - start; +} + static byte * bgp_create_update(struct bgp_conn *conn, byte *buf) { + struct bgp_proto *bgp = conn->bgp; + struct bgp_bucket *buck; + int remains = BGP_MAX_PACKET_LENGTH - BGP_HEADER_LENGTH - 4; + byte *w, *wold; + ip_addr ip; + int wd_size = 0; + int r_size = 0; + DBG("BGP: Sending update\n"); + w = buf+2; + if ((buck = bgp->withdraw_bucket) && !EMPTY_LIST(buck->prefixes)) + { + DBG("Withdrawn routes:\n"); + wd_size = bgp_encode_prefixes(bgp, w, buck, remains); + w += wd_size; + remains -= wd_size; + } + put_u16(buf, wd_size); - bug("Don't know how to create updates"); + if (remains >= 2048) + { + while ((buck = (struct bgp_bucket *) HEAD(bgp->bucket_queue))->send_node.next) + { + if (EMPTY_LIST(buck->prefixes)) + { + DBG("Deleting empty bucket %p\n", buck); + rem_node(&buck->send_node); + bgp_free_bucket(bgp, buck); + continue; + } + DBG("Processing bucket %p\n", buck); + w = bgp_encode_attrs(w, buck); + remains = BGP_MAX_PACKET_LENGTH - BGP_HEADER_LENGTH - (w-buf); + r_size = bgp_encode_prefixes(bgp, w, buck, remains); + w += r_size; + break; + } + } + else + { + put_u16(w, 0); + w += 2; + } + return (wd_size || r_size) ? w : NULL; } static void @@ -225,7 +289,8 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, int len) memcpy(&prefix, pp, q); \ pp += q; \ ll -= q; \ - prefix = ipa_and(ipa_ntoh(prefix), ipa_mkmask(b)); \ + ipa_ntoh(prefix); \ + prefix = ipa_and(prefix, ipa_mkmask(b)); \ pxlen = b; \ } while (0) /* FIXME: Check validity of prefixes */ |