diff options
Diffstat (limited to 'proto/bgp')
| -rw-r--r-- | proto/bgp/bgp.h | 5 | ||||
| -rw-r--r-- | proto/bgp/packets.c | 410 |
2 files changed, 91 insertions, 324 deletions
diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h index 5f68e3de..7c96e851 100644 --- a/proto/bgp/bgp.h +++ b/proto/bgp/bgp.h @@ -434,6 +434,7 @@ struct bgp_write_state { int as4_session; int add_path; int mpls; + int sham; eattr *mp_next_hop; const adata *mpls_labels; @@ -624,9 +625,7 @@ struct rte *bgp_rte_modify_stale(struct rte *r, struct linpool *pool); u32 bgp_rte_igp_metric(struct rte *); void bgp_rt_notify(struct proto *P, struct channel *C, net *n, rte *new, rte *old); int bgp_preexport(struct channel *, struct rte *); -void bgp_rte_update_in_notify(const struct proto *P, const struct channel *C, - const net *net, const struct rte *new, const struct rte *old, - const struct rte_src *src); +void bgp_rte_update_in_notify(struct channel *C, const net_addr *n, const struct rte *new, const struct rte_src *src); int bgp_get_attr(const struct eattr *e, byte *buf, int buflen); void bgp_get_route_info(struct rte *, byte *buf); int bgp_total_aigp_metric_(rte *e, u64 *metric, const struct adata **ad); diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c index bec8cd91..42016eae 100644 --- a/proto/bgp/packets.c +++ b/proto/bgp/packets.c @@ -1566,7 +1566,10 @@ bgp_encode_nlri_ip4(struct bgp_write_state *s, struct bgp_bucket *buck, byte *bu memcpy(pos, &a, b); ADVANCE(pos, size, b); - bgp_free_prefix(s->channel, px); + if (!s->sham) + bgp_free_prefix(s->channel, px); + else + rem_node(&px->buck_node); } return pos - buf; @@ -1651,7 +1654,10 @@ bgp_encode_nlri_ip6(struct bgp_write_state *s, struct bgp_bucket *buck, byte *bu memcpy(pos, &a, b); ADVANCE(pos, size, b); - bgp_free_prefix(s->channel, px); + if (!s->sham) + bgp_free_prefix(s->channel, px); + else + rem_node(&px->buck_node); } return pos - buf; @@ -1739,7 +1745,10 @@ bgp_encode_nlri_vpn4(struct bgp_write_state *s, struct bgp_bucket *buck, byte *b memcpy(pos, &a, b); ADVANCE(pos, size, b); - bgp_free_prefix(s->channel, px); + if (!s->sham) + bgp_free_prefix(s->channel, px); + else + rem_node(&px->buck_node); } return pos - buf; @@ -1836,7 +1845,10 @@ bgp_encode_nlri_vpn6(struct bgp_write_state *s, struct bgp_bucket *buck, byte *b memcpy(pos, &a, b); ADVANCE(pos, size, b); - bgp_free_prefix(s->channel, px); + if (!s->sham) + bgp_free_prefix(s->channel, px); + else + rem_node(&px->buck_node); } return pos - buf; @@ -1923,7 +1935,10 @@ bgp_encode_nlri_flow4(struct bgp_write_state *s, struct bgp_bucket *buck, byte * memcpy(pos, net->data, flen); ADVANCE(pos, size, flen); - bgp_free_prefix(s->channel, px); + if (!s->sham) + bgp_free_prefix(s->channel, px); + else + rem_node(&px->buck_node); } return pos - buf; @@ -2015,7 +2030,10 @@ bgp_encode_nlri_flow6(struct bgp_write_state *s, struct bgp_bucket *buck, byte * memcpy(pos, net->data, flen); ADVANCE(pos, size, flen); - bgp_free_prefix(s->channel, px); + if (!s->sham) + bgp_free_prefix(s->channel, px); + else + rem_node(&px->buck_node); } return pos - buf; @@ -2242,224 +2260,6 @@ bgp_update_next_hop(struct bgp_export_state *s, eattr *a, ea_list **to) #define MAX_ATTRS_LENGTH (end-buf+BGP_HEADER_LENGTH - 1024) -/** - * Following functions starting with prefix bgp_bmp_* compose BGP UPDATE messages. - * Their implementation has been adopted from relevant function without 'bmp_' part in - * their names. - */ - -// Buffer @buf should be big enough. It means that there should be available at least 19 bytes -static byte * -bgp_bmp_prepare_bgp_hdr(byte *buf, const u16 msg_size, const u8 msg_type) -{ - if (!buf) - { - return NULL; - } - - memset(buf + BGP_MSG_HDR_MARKER_POS, 0xff, BGP_MSG_HDR_MARKER_SIZE); - put_u16(buf + BGP_MSG_HDR_LENGTH_POS, msg_size); - put_u8(buf + BGP_MSG_HDR_TYPE_POS, msg_type); - - return buf + BGP_MSG_HDR_TYPE_POS + BGP_MSG_HDR_TYPE_SIZE; -} - -static uint -bgp_bmp_encode_nlri_ip4(struct bgp_write_state *s, const net *n, - const u32 path_id, byte *buf, uint size) -{ - const struct net_addr_ip4 *naddr = (net_addr_ip4 *)n->n.addr; - - byte *pos = buf; - /* Encode path ID */ - if (s->add_path) - { - put_u32(pos, path_id); - ADVANCE(pos, size, 4); - } - - /* Encode prefix length */ - *pos = naddr->pxlen; - ADVANCE(pos, size, 1); - - /* Encode MPLS labels */ - if (s->mpls) - { - bgp_encode_mpls_labels(s, s->mpls_labels, &pos, &size, pos - 1); - } - - /* Encode prefix body */ - ip4_addr a = ip4_hton(naddr->prefix); - uint b = (naddr->pxlen + 7) / 8; - memcpy(pos, &a, b); - ADVANCE(pos, size, b); - - return pos - buf; -} - -static uint -bgp_bmp_encode_nlri_ip6(struct bgp_write_state *s, const net *n, - const u32 path_id, byte *buf, uint size) -{ - if (size < BGP_NLRI_MAX) - { - return 0; - } - - const struct net_addr_ip6 *naddr = (net_addr_ip6 *)n->n.addr; - byte *pos = buf; - /* Encode path ID */ - if (s->add_path) - { - put_u32(pos, path_id); - ADVANCE(pos, size, 4); - } - - /* Encode prefix length */ - *pos = naddr->pxlen; - ADVANCE(pos, size, 1); - - /* Encode MPLS labels */ - if (s->mpls) - { - bgp_encode_mpls_labels(s, s->mpls_labels, &pos, &size, pos - 1); - } - - /* Encode prefix body */ - ip6_addr a = ip6_hton(naddr->prefix); - uint b = (naddr->pxlen + 7) / 8; - memcpy(pos, &a, b); - ADVANCE(pos, size, b); - - return pos - buf; -} - -static byte * -bgp_bmp_create_ip_reach(struct bgp_write_state *s, const net *n, - const struct rte *new, const struct rte *old, const u32 path_id, - byte *buf, uint size) -{ - /* - * 2 B Withdrawn Routes Length (zero) - * --- IPv4 Withdrawn Routes NLRI (unused) - * 2 B Total Path Attribute Length - * var Path Attributes - * var IPv4 Network Layer Reachability Information - */ - - int lr, la; // Route length, attribute length - ea_list *attrs = new ? new->attrs->eattrs : old->attrs->eattrs; - bgp_fix_attr_flags(attrs); - - la = bgp_encode_attrs(s, attrs, buf + 2, buf + size - 2); - if (la < 0) - { - /* Attribute list too long */ - log(L_ERR "Failed to encode UPDATE msg attributes"); - return NULL; - } - - put_u16(buf, la); - lr = bgp_bmp_encode_nlri_ip4(s, n, path_id, buf + 2 + la, size - (2 + la)); - - return buf + 2 + la + lr; -} - -static byte * -bgp_bmp_create_mp_reach(struct bgp_write_state *s, const net *n, - const struct rte *new, const struct rte *old, const u32 path_id, - byte *buf, uint size) -{ - /* - * 2 B IPv4 Withdrawn Routes Length (zero) - * --- IPv4 Withdrawn Routes NLRI (unused) - * 2 B Total Path Attribute Length - * 1 B MP_REACH_NLRI hdr - Attribute Flags - * 1 B MP_REACH_NLRI hdr - Attribute Type Code - * 2 B MP_REACH_NLRI hdr - Length of Attribute Data - * 2 B MP_REACH_NLRI data - Address Family Identifier - * 1 B MP_REACH_NLRI data - Subsequent Address Family Identifier - * 1 B MP_REACH_NLRI data - Length of Next Hop Network Address - * var MP_REACH_NLRI data - Network Address of Next Hop - * 1 B MP_REACH_NLRI data - Reserved (zero) - * var MP_REACH_NLRI data - Network Layer Reachability Information - * var Rest of Path Attributes - * --- IPv4 Network Layer Reachability Information (unused) - */ - - int lh, lr, la; /* Lengths of next hop, NLRI and attributes */ - - /* Begin of MP_REACH_NLRI atribute */ - buf[4] = BAF_OPTIONAL | BAF_EXT_LEN; - buf[5] = BA_MP_REACH_NLRI; - put_u16(buf+6, 0); /* Will be fixed later */ - put_af3(buf+8, s->channel->afi); - byte *pos = buf+11; - byte *end = buf + size; - /* Encode attributes to temporary buffer */ - byte *abuf = alloca(MAX_ATTRS_LENGTH); - - ea_list *attrs = new ? new->attrs->eattrs : old->attrs->eattrs; - bgp_fix_attr_flags(attrs); - - la = bgp_encode_attrs(s, attrs, abuf, abuf + MAX_ATTRS_LENGTH); - if (la < 0) - { - /* Attribute list too long */ - log(L_ERR "Failed to encode UPDATE msg attributes"); - return NULL; - } - - /* Encode the next hop */ - lh = bgp_encode_next_hop(s, s->mp_next_hop, pos+1); - *pos = lh; - pos += 1+lh; - - /* Reserved field */ - *pos++ = 0; - - /* Encode the NLRI */ - lr = bgp_bmp_encode_nlri_ip6(s, n, path_id, pos, end - (buf + la)); - pos += lr; - - /* End of MP_REACH_NLRI atribute, update data length */ - put_u16(buf+6, pos-buf-8); - - /* Copy remaining attributes */ - memcpy(pos, abuf, la); - pos += la; - - /* Initial UPDATE fields */ - put_u16(buf+0, 0); - put_u16(buf+2, pos-buf-4); - - return pos; -} - -static byte * -bgp_bmp_create_ip_unreach(struct bgp_write_state *s, const net *n, - const struct rte *new, const struct rte *old, const u32 path_id, - byte *buf, uint size) -{ - /* - * 2 B Withdrawn Routes Length - * var IPv4 Withdrawn Routes NLRI - * 2 B Total Path Attribute Length (zero) - * --- Path Attributes (unused) - * --- IPv4 Network Layer Reachability Information (unused) - */ - - uint len = 0; - bool is_withdrawn = !new && old; - if (is_withdrawn) - { - len = bgp_bmp_encode_nlri_ip4(s, n, path_id, buf + 2, size - 2); - } - - put_u16(buf, len); - return buf + 2 + len; -} - static byte * bgp_create_ip_reach(struct bgp_write_state *s, struct bgp_bucket *buck, byte *buf, byte *end) { @@ -2477,7 +2277,8 @@ bgp_create_ip_reach(struct bgp_write_state *s, struct bgp_bucket *buck, byte *bu if (la < 0) { /* Attribute list too long */ - bgp_withdraw_bucket(s->channel, buck); + if (!s->sham) + bgp_withdraw_bucket(s->channel, buck); return NULL; } @@ -2524,7 +2325,8 @@ bgp_create_mp_reach(struct bgp_write_state *s, struct bgp_bucket *buck, byte *bu if (la < 0) { /* Attribute list too long */ - bgp_withdraw_bucket(s->channel, buck); + if (!s->sham) + bgp_withdraw_bucket(s->channel, buck); return NULL; } @@ -2606,53 +2408,11 @@ bgp_create_mp_unreach(struct bgp_write_state *s, struct bgp_bucket *buck, byte * } static byte * -bgp_bmp_create_mp_unreach(struct bgp_write_state *s, const net *n, - const struct rte *new, const struct rte *old, const u32 path_id, - byte *buf, uint size) -{ - /* - * 2 B Withdrawn Routes Length (zero) - * --- IPv4 Withdrawn Routes NLRI (unused) - * 2 B Total Path Attribute Length - * 1 B MP_UNREACH_NLRI hdr - Attribute Flags - * 1 B MP_UNREACH_NLRI hdr - Attribute Type Code - * 2 B MP_UNREACH_NLRI hdr - Length of Attribute Data - * 2 B MP_UNREACH_NLRI data - Address Family Identifier - * 1 B MP_UNREACH_NLRI data - Subsequent Address Family Identifier - * var MP_UNREACH_NLRI data - Network Layer Reachability Information - * --- IPv4 Network Layer Reachability Information (unused) - */ - - uint len = 0; - bool is_withdrawn = !new && old; - if (is_withdrawn) - { - len = bgp_bmp_encode_nlri_ip6(s, n, path_id, buf + 11, size); - } - - put_u16(buf+0, 0); - put_u16(buf+2, 7+len); - - /* Begin of MP_UNREACH_NLRI atribute */ - buf[4] = BAF_OPTIONAL | BAF_EXT_LEN; - buf[5] = BA_MP_UNREACH_NLRI; - - put_u16(buf+6, 3+len); - put_af3(buf+8, s->channel->afi); - - return buf+11+len; -} - -void -bgp_rte_update_in_notify(const struct proto *P, const struct channel *C, - const net *n, const struct rte *new, const struct rte *old, - const struct rte_src *src) +bgp_create_update_bmp(struct bgp_channel *c, byte *buf, struct bgp_bucket *buck, bool update) { - struct bgp_proto *p = (struct bgp_proto *)P; - struct bgp_channel *c = (struct bgp_channel *)C; - byte buf[BGP_MAX_EXT_MSG_LENGTH] = { 0x00 }; - byte *pkt = buf + BGP_HEADER_LENGTH; - byte *end = pkt + (bgp_max_packet_length(p->conn) - BGP_HEADER_LENGTH); + struct bgp_proto *p = (void *) c->c.proto; + byte *end = buf + (BGP_MAX_EXT_MSG_LENGTH - BGP_HEADER_LENGTH); + /* FIXME: must be a bit shorter */ struct bgp_caps *peer = p->conn->remote_caps; const struct bgp_af_caps *rem = bgp_find_af_caps(peer, c->afi); @@ -2660,65 +2420,73 @@ bgp_rte_update_in_notify(const struct proto *P, const struct channel *C, .proto = p, .channel = c, .pool = tmp_linpool, - .mp_reach = (bgp_channel_is_ipv6(c) || rem->ext_next_hop), - .as4_session = peer->as4_support, + .mp_reach = (c->afi != BGP_AF_IPV4) || rem->ext_next_hop, + .as4_session = 1, .add_path = c->add_path_rx, .mpls = c->desc->mpls, + .sham = 1, }; - const u32 path_id = c->add_path_rx ? src->private_id : 0; - byte *pos = pkt; - if (!s.mp_reach) + if (!update) { - pos = bgp_bmp_create_ip_unreach(&s, n, new, old, path_id, pkt, end - pkt); - if (!pos) - { - log(L_ERR "Failed to create unreachable field in UPDATE message"); - return; - } - - pos = bgp_bmp_create_ip_reach(&s, n, new, old, path_id, pos, end - pos); - if (!pos) - { - log(L_ERR "Failed to create reachable field in UPDATE message"); - return; - } - - bgp_bmp_prepare_bgp_hdr(buf, pos - buf, PKT_UPDATE); - bmp_route_monitor_put_update_in_pre_msg(buf, pos - buf); + return !s.mp_reach ? + bgp_create_ip_unreach(&s, buck, buf, end): + bgp_create_mp_unreach(&s, buck, buf, end); } - else if (new) // && s.mp_reach + else { - pos = s.mp_reach - ? bgp_bmp_create_mp_reach(&s, n, new, old, path_id, pos, end - pos) - : bgp_bmp_create_ip_reach(&s, n, new, old, path_id, pos, end - pos); - if (!pos) - { - log(L_ERR "Failed to create reachable field in UPDATE message"); - return; - } - - bgp_bmp_prepare_bgp_hdr(buf, pos - buf, PKT_UPDATE); - bmp_route_monitor_put_update_in_pre_msg(buf, pos - buf); + return !s.mp_reach ? + bgp_create_ip_reach(&s, buck, buf, end): + bgp_create_mp_reach(&s, buck, buf, end); } +} - if (!new && old) - { - bmp_route_monitor_update_in_pre_commit(p); - bmp_route_monitor_update_in_pre_end(); - bmp_route_monitor_update_in_pre_begin(); - pkt = buf + BGP_HEADER_LENGTH; - end = pkt + (bgp_max_packet_length(p->conn) - BGP_HEADER_LENGTH); - pos = bgp_bmp_create_mp_unreach(&s, n, new, old, path_id, pkt, end - pkt); - if (!pos) - { - log(L_ERR "Failed to create unreachable field in UPDATE message"); - return; - } +static byte * +bgp_bmp_prepare_bgp_hdr(byte *buf, const u16 msg_size, const u8 msg_type) +{ + memset(buf + BGP_MSG_HDR_MARKER_POS, 0xff, BGP_MSG_HDR_MARKER_SIZE); + put_u16(buf + BGP_MSG_HDR_LENGTH_POS, msg_size); + put_u8(buf + BGP_MSG_HDR_TYPE_POS, msg_type); - bgp_bmp_prepare_bgp_hdr(buf, pos - buf, PKT_UPDATE); - bmp_route_monitor_put_update_in_pre_msg(buf, pos - buf); - } + return buf + BGP_MSG_HDR_TYPE_POS + BGP_MSG_HDR_TYPE_SIZE; +} + +void +bgp_rte_update_in_notify(struct channel *C, const net_addr *n, + const struct rte *new, const struct rte_src *src) +{ +// struct bgp_proto *p = (void *) C->proto; + struct bgp_channel *c = (void *) C; + + byte buf[BGP_MAX_EXT_MSG_LENGTH]; + byte *pkt = buf + BGP_HEADER_LENGTH; + + ea_list *attrs = new ? new->attrs->eattrs : NULL; + uint ea_size = new ? (sizeof(ea_list) + attrs->count * sizeof(eattr)) : 0; + uint bucket_size = sizeof(struct bgp_bucket) + ea_size; + uint prefix_size = sizeof(struct bgp_prefix) + n->length; + + /* Sham bucket */ + struct bgp_bucket *b = alloca(bucket_size); + *b = (struct bgp_bucket) { }; + init_list(&b->prefixes); + + if (attrs) + memcpy(b->eattrs, attrs, ea_size); + + /* Sham prefix */ + struct bgp_prefix *px = alloca(prefix_size); + *px = (struct bgp_prefix) { }; + px->path_id = src->private_id; + net_copy(px->net, n); + add_tail(&b->prefixes, &px->buck_node); + + byte *end = bgp_create_update_bmp(c, pkt, b, !!new); + if (!end) + return; + + bgp_bmp_prepare_bgp_hdr(buf, end - buf, PKT_UPDATE); + bmp_route_monitor_put_update_in_pre_msg(buf, end - buf); } static byte * |