* nor RFC2385 (which requires a kernel patch on 2.4 kernels).
*/
-char const *cvs_id_bgp = "$Id: bgp.c,v 1.12 2005/09/02 23:39:36 bodea Exp $";
-
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
static void bgp_clear(struct bgp_peer *peer);
static void bgp_set_retry(struct bgp_peer *peer);
-static void bgp_cidr(in_addr_t ip, in_addr_t mask, struct bgp_ip_prefix *pfx);
static struct bgp_route_list *bgp_insert_route(struct bgp_route_list *head,
struct bgp_route_list *new);
static struct bgp_route6_list *bgp_insert_route6(struct bgp_route6_list *head,
struct bgp_route6_list *new);
+static void bgp_process_timers(struct bgp_peer *peer);
static void bgp_free_routes(struct bgp_route_list *routes);
static void bgp_free_routes6(struct bgp_route6_list *routes);
static char const *bgp_msg_type_str(uint8_t type);
static int bgp_send_update6(struct bgp_peer *peer);
static int bgp_send_notification(struct bgp_peer *peer, uint8_t code,
uint8_t subcode);
-static int bgp_send_notification_full(struct bgp_peer *peer, uint8_t code,
- uint8_t subcode, char *notification_data, uint16_t data_len);
static uint16_t our_as;
static struct bgp_route_list *bgp_routes = 0;
/* start connection with a peer */
int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive,
- int hold, int enable)
+ int hold, struct in_addr update_source, int enable)
{
struct hostent *h;
int ibgp;
}
memcpy(&peer->addr, h->h_addr, sizeof(peer->addr));
+ peer->source_addr = update_source.s_addr;
peer->as = as > 0 ? as : our_as;
ibgp = peer->as == our_as;
/* NEXT_HOP */
a.flags = BGP_PATH_ATTR_FLAG_TRANS;
a.code = BGP_PATH_ATTR_CODE_NEXT_HOP;
- ip = my_address; /* we're it */
+ if (config->nexthop_address)
+ {
+ ip = config->nexthop_address;
+ }
+ else
+ {
+ ip = my_address; /* we're it */
+ }
a.data.s.len = sizeof(ip);
memcpy(a.data.s.value, &ip, sizeof(ip));
memcpy(peer->path_attrs, path_attrs, peer->path_attr_len);
+ /* multiprotocol attributes initialization */
+ if (config->ipv6_prefix.s6_addr[0])
+ {
+ struct bgp_attr_mp_reach_nlri_partial mp_reach_nlri_partial;
+ struct bgp_attr_mp_unreach_nlri_partial mp_unreach_nlri_partial;
+
+ a.flags = BGP_PATH_ATTR_FLAG_OPTIONAL;
+ a.code = BGP_PATH_ATTR_CODE_MP_REACH_NLRI;
+ a.data.s.len = 0; /* will be set on UPDATE */
+
+ mp_reach_nlri_partial.afi = htons(BGP_MP_AFI_IPv6);
+ mp_reach_nlri_partial.safi = BGP_MP_SAFI_UNICAST;
+ mp_reach_nlri_partial.reserved = 0;
+ mp_reach_nlri_partial.next_hop_len = 16;
+
+ /* use the defined nexthop6, or our address in ipv6_prefix */
+ if (config->nexthop6_address.s6_addr[0])
+ memcpy(&mp_reach_nlri_partial.next_hop,
+ &config->nexthop6_address.s6_addr, 16);
+ else
+ {
+ /* our address is ipv6prefix::1 */
+ memcpy(&mp_reach_nlri_partial.next_hop,
+ &config->ipv6_prefix.s6_addr, 16);
+ mp_reach_nlri_partial.next_hop[15] = 1;
+ }
+
+ memcpy(&a.data.s.value, &mp_reach_nlri_partial,
+ sizeof(struct bgp_attr_mp_reach_nlri_partial));
+ memcpy(&peer->mp_reach_nlri_partial, &a,
+ BGP_PATH_ATTR_MP_REACH_NLRI_PARTIAL_SIZE);
+
+ a.flags = BGP_PATH_ATTR_FLAG_OPTIONAL | BGP_PATH_ATTR_FLAG_EXTLEN;
+ a.code = BGP_PATH_ATTR_CODE_MP_UNREACH_NLRI;
+ a.data.e.len = 0; /* will be set on UPDATE */
+
+ mp_unreach_nlri_partial.afi = htons(BGP_MP_AFI_IPv6);
+ mp_unreach_nlri_partial.safi = BGP_MP_SAFI_UNICAST;
+
+ memcpy(&a.data.e.value, &mp_unreach_nlri_partial,
+ sizeof(struct bgp_attr_mp_unreach_nlri_partial));
+ memcpy(&peer->mp_unreach_nlri_partial, &a,
+ BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE);
+ }
+
+ peer->mp_handling = HandlingUnknown;
+
LOG(4, 0, 0, "Initiating BGP connection to %s (routing %s)\n",
name, enable ? "enabled" : "suspended");
bgp_halt(peer); /* give up */
}
-/* convert ip/mask to CIDR notation */
-static void bgp_cidr(in_addr_t ip, in_addr_t mask, struct bgp_ip_prefix *pfx)
-{
- int i;
- uint32_t b;
-
- /* convert to prefix notation */
- pfx->len = 32;
- pfx->prefix = ip;
-
- if (!mask) /* bogus */
- mask = 0xffffffff;
-
- for (i = 0; i < 32 && ((b = ntohl(1 << i)), !(mask & b)); i++)
- {
- pfx->len--;
- pfx->prefix &= ~b;
- }
-}
-
/* insert route into list; sorted */
static struct bgp_route_list *bgp_insert_route(struct bgp_route_list *head,
struct bgp_route_list *new)
* that if that route is later deleted we don't have to be concerned
* about adding back the more specific one).
*/
-int bgp_add_route(in_addr_t ip, in_addr_t mask)
+int bgp_add_route(in_addr_t ip, int prefixlen)
{
struct bgp_route_list *r = bgp_routes;
struct bgp_route_list add;
int i;
- bgp_cidr(ip, mask, &add.dest);
+ add.dest.prefix = ip;
+ add.dest.len = prefixlen;
add.next = 0;
/* check for duplicate */
/* flag established peers for update */
for (i = 0; i < BGP_NUM_PEERS; i++)
- if (bgp_peers[i].state == Established)
+ if (bgp_peers[i].state == Established
+ && bgp_peers[i].mp_handling == HandleIPv6Routes)
bgp_peers[i].update_routes6 = 1;
LOG(4, 0, 0, "Registered BGP route %s/%d\n",
}
/* remove route from list for peers */
-int bgp_del_route(in_addr_t ip, in_addr_t mask)
+int bgp_del_route(in_addr_t ip, int prefixlen)
{
struct bgp_route_list *r = bgp_routes;
struct bgp_route_list *e = 0;
struct bgp_route_list del;
int i;
- bgp_cidr(ip, mask, &del.dest);
+ del.dest.prefix = ip;
+ del.dest.len = prefixlen;
del.next = 0;
/* find entry in routes list and remove */
/* flag established peers for update */
for (i = 0; i < BGP_NUM_PEERS; i++)
- if (bgp_peers[i].state == Established)
+ if (bgp_peers[i].state == Established
+ && bgp_peers[i].mp_handling == HandleIPv6Routes)
bgp_peers[i].update_routes6 = 1;
LOG(4, 0, 0, "Removed BGP route %s/%d\n",
}
/* process timers */
- if (peer->state == Established)
- {
- if (time_now > peer->expire_time)
- {
- LOG(1, 0, 0, "No message from BGP peer %s in %ds\n",
- peer->name, peer->hold);
+ bgp_process_timers(peer);
+ }
- bgp_send_notification(peer, BGP_ERR_HOLD_TIMER_EXP, 0);
- continue;
- }
+ return 1;
+}
- if (time_now > peer->keepalive_time && !peer->outbuf->packet.header.len)
- bgp_send_keepalive(peer);
- }
- else if (peer->state == Idle)
- {
- if (time_now > peer->retry_time)
- bgp_connect(peer);
- }
- else if (time_now > peer->state_time + BGP_STATE_TIME)
+/* process bgp timers only */
+void bgp_process_peers_timers()
+{
+ int i;
+
+ if (!bgp_configured)
+ return;
+
+ for (i = 0; i < BGP_NUM_PEERS; i++)
+ {
+ struct bgp_peer *peer = &bgp_peers[i];
+
+ if (peer->state == Disabled)
+ continue;
+
+ bgp_process_timers(peer);
+ }
+}
+
+static void bgp_process_timers(struct bgp_peer *peer)
+{
+ if (peer->state == Established)
+ {
+ if (time_now > peer->expire_time)
{
- LOG(1, 0, 0, "%s timer expired for BGP peer %s\n",
- bgp_state_str(peer->state), peer->name);
+ LOG(1, 0, 0, "No message from BGP peer %s in %ds\n",
+ peer->name, peer->hold);
- bgp_restart(peer);
+ bgp_send_notification(peer, BGP_ERR_HOLD_TIMER_EXP, 0);
+ return;
}
+
+ if (time_now > peer->keepalive_time && !peer->outbuf->packet.header.len)
+ bgp_send_keepalive(peer);
}
+ else if (peer->state == Idle)
+ {
+ if (time_now > peer->retry_time)
+ bgp_connect(peer);
+ }
+ else if (time_now > peer->state_time + BGP_STATE_TIME)
+ {
+ LOG(1, 0, 0, "%s timer expired for BGP peer %s\n",
+ bgp_state_str(peer->state), peer->name);
- return 1;
+ bgp_restart(peer);
+ }
}
static void bgp_free_routes(struct bgp_route_list *routes)
{
static int bgp_port = 0;
struct sockaddr_in addr;
+ struct sockaddr_in source_addr;
struct epoll_event ev;
if (!bgp_port)
/* set to non-blocking */
fcntl(peer->sock, F_SETFL, fcntl(peer->sock, F_GETFL, 0) | O_NONBLOCK);
+ /* set source address */
+ memset(&source_addr, 0, sizeof(source_addr));
+ source_addr.sin_family = AF_INET;
+ source_addr.sin_addr.s_addr = peer->source_addr; /* defaults to INADDR_ANY */
+ if (bind(peer->sock, (struct sockaddr *) &source_addr, sizeof(source_addr)) < 0)
+ {
+ LOG(1, 0, 0, "Can't set source address to %s: %s\n",
+ inet_ntoa(source_addr.sin_addr), strerror(errno));
+
+ bgp_set_retry(peer);
+ return 0;
+ }
+
/* try connect */
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
LOG(4, 0, 0, "BGP peer %s: state Active\n", inet_ntoa(addr.sin_addr));
- peer->handle_ipv6_routes = 0;
-
return bgp_send_open(peer);
}
LOG(4, 0, 0, "BGP peer %s: state Active\n", peer->name);
- peer->handle_ipv6_routes = 0;
-
return bgp_send_open(peer);
}
param_offset < data.opt_len;
param_offset += 2 + param->len)
{
- param = (struct bgp_opt_param *)(&data.opt_params + param_offset);
+ param = (struct bgp_opt_param *)((char *)&data.opt_params + param_offset);
/* sensible check */
if (data.opt_len - param_offset < 2
capabilities_len = param->len;
capabilities = (char *)¶m->value;
- }
- /* look for BGP multiprotocol capability */
- if (capabilities)
- {
+ /* look for BGP multiprotocol capability */
for (capability_offset = 0;
capability_offset < capabilities_len;
capability_offset += 2 + capability->len)
LOG(4, 0, 0, "Unsupported Capability code %d from BGP peer %s\n",
capability->code, peer->name);
- bgp_send_notification_full(peer, BGP_ERR_OPEN, BGP_ERR_OPN_UNSUP_CAP,
- (char *)capability, 2 + capability->len);
/* we don't terminate, still; we just jump to the next one */
continue;
}
mp_cap = (struct bgp_mp_cap_param *)&capability->value;
/* the only <AFI, SAFI> tuple we support */
- if (ntohs(mp_cap->afi) != AF_INET6 && mp_cap->safi != BGP_MP_SAFI_UNICAST)
+ if (ntohs(mp_cap->afi) != BGP_MP_AFI_IPv6 && mp_cap->safi != BGP_MP_SAFI_UNICAST)
{
LOG(4, 0, 0, "Unsupported multiprotocol AFI %d and SAFI %d from BGP peer %s\n",
mp_cap->afi, mp_cap->safi, peer->name);
- bgp_send_notification_full(peer, BGP_ERR_OPEN, BGP_ERR_OPN_UNSUP_CAP,
- (char *)capability, 2 + capability->len);
/* we don't terminate, still; we just jump to the next one */
continue;
}
- peer->handle_ipv6_routes = 1;
+ /* yes it can! */
+ peer->mp_handling = HandleIPv6Routes;
}
}
+ if (peer->mp_handling != HandleIPv6Routes)
+ {
+ peer->mp_handling = DoesntHandleIPv6Routes;
+ if (config->ipv6_prefix.s6_addr[0])
+ LOG(1, 0, 0, "Warning: BGP peer %s doesn't handle IPv6 prefixes updates\n",
+ peer->name);
+ }
+
/* next transition requires an exchange of keepalives */
bgp_send_keepalive(peer);
}
if (notification->error_code == BGP_ERR_CEASE)
{
LOG(4, 0, 0, "BGP peer %s sent CEASE\n", peer->name);
- bgp_restart(peer);
+ bgp_set_retry(peer);
+ return 0;
+ }
+
+ if (notification->error_code == BGP_ERR_OPEN
+ && notification->error_subcode == BGP_ERR_OPN_UNSUP_PARAM)
+ {
+ LOG(4, 0, 0, "BGP peer %s doesn't support BGP Capabilities\n", peer->name);
+ peer->mp_handling = DoesntHandleIPv6Routes;
+ bgp_set_retry(peer);
return 0;
}
an "unsupported capability" message, we disable IPv6 routes for
this peer */
LOG(4, 0, 0, "BGP peer %s doesn't support IPv6 routes advertisement\n", peer->name);
- peer->handle_ipv6_routes = 0;
+ peer->mp_handling = DoesntHandleIPv6Routes;
break;
}
static int bgp_send_open(struct bgp_peer *peer)
{
struct bgp_data_open data;
- struct bgp_mp_cap_param mp_ipv6 = { htons(AF_INET6), 0, BGP_MP_SAFI_UNICAST };
+ struct bgp_mp_cap_param mp_ipv6 = { htons(BGP_MP_AFI_IPv6), 0, BGP_MP_SAFI_UNICAST };
struct bgp_capability cap_mp_ipv6;
struct bgp_opt_param param_cap_mp_ipv6;
uint16_t len = sizeof(peer->outbuf->packet.header);
data.version = BGP_VERSION;
data.as = htons(our_as);
data.hold_time = htons(peer->hold);
- data.identifier = my_address;
+ /* use the source IP we use as identifier, if available */
+ if (peer->source_addr != INADDR_ANY)
+ data.identifier = peer->source_addr;
+ else
+ data.identifier = my_address;
- /* construct the param and capability */
- cap_mp_ipv6.code = BGP_CAP_CODE_MP;
- cap_mp_ipv6.len = sizeof(mp_ipv6);
- memcpy(&cap_mp_ipv6.value, &mp_ipv6, cap_mp_ipv6.len);
+ /* if we know peer doesn't support MP (mp_handling == DoesntHandleIPv6Routes)
+ then don't add this parameter */
+ if (config->ipv6_prefix.s6_addr[0]
+ && (peer->mp_handling == HandlingUnknown
+ || peer->mp_handling == HandleIPv6Routes))
+ {
+ /* construct the param and capability */
+ cap_mp_ipv6.code = BGP_CAP_CODE_MP;
+ cap_mp_ipv6.len = sizeof(mp_ipv6);
+ memcpy(&cap_mp_ipv6.value, &mp_ipv6, cap_mp_ipv6.len);
- param_cap_mp_ipv6.type = BGP_PARAM_TYPE_CAPABILITY;
- param_cap_mp_ipv6.len = 2 + sizeof(mp_ipv6);
- memcpy(¶m_cap_mp_ipv6.value, &cap_mp_ipv6, param_cap_mp_ipv6.len);
+ param_cap_mp_ipv6.type = BGP_PARAM_TYPE_CAPABILITY;
+ param_cap_mp_ipv6.len = 2 + sizeof(mp_ipv6);
+ memcpy(¶m_cap_mp_ipv6.value, &cap_mp_ipv6, param_cap_mp_ipv6.len);
- data.opt_len = 2 + param_cap_mp_ipv6.len;
- memcpy(&data.opt_params, ¶m_cap_mp_ipv6, data.opt_len);
+ data.opt_len = 2 + param_cap_mp_ipv6.len;
+ memcpy(&data.opt_params, ¶m_cap_mp_ipv6, data.opt_len);
+ }
+ else
+ data.opt_len = 0;
- memcpy(peer->outbuf->packet.data, &data, BGP_DATA_OPEN_SIZE);
- len += BGP_DATA_OPEN_SIZE;
+ memcpy(peer->outbuf->packet.data, &data, BGP_DATA_OPEN_SIZE + data.opt_len);
+ len += BGP_DATA_OPEN_SIZE + data.opt_len;
peer->outbuf->packet.header.len = htons(len);
peer->outbuf->done = 0;
/* send/buffer UPDATE message for IPv6 routes */
static int bgp_send_update6(struct bgp_peer *peer)
{
+ uint16_t attr_len;
+ uint16_t unreach_len = 0;
+ char *unreach_len_pos;
+ uint8_t reach_len;
+ uint16_t len = sizeof(peer->outbuf->packet.header);
+ struct bgp_route6_list *have = peer->routes6;
+ struct bgp_route6_list *want = peer->routing ? bgp_routes6 : 0;
+ struct bgp_route6_list *e = 0;
+ struct bgp_route6_list *add = 0;
+ int s;
+ char ipv6addr[INET6_ADDRSTRLEN];
+
+ char *data = (char *) &peer->outbuf->packet.data;
+
+ /* need leave room for attr_len, bgp_path_attrs and one prefix */
+ char *max = (char *) &peer->outbuf->packet.data
+ + sizeof(peer->outbuf->packet.data)
+ - sizeof(attr_len) - peer->path_attr_len_without_nexthop
+ - BGP_PATH_ATTR_MP_REACH_NLRI_PARTIAL_SIZE - sizeof(struct bgp_ip6_prefix);
+
+ memset(peer->outbuf->packet.header.marker, 0xff,
+ sizeof(peer->outbuf->packet.header.marker));
+
+ peer->outbuf->packet.header.type = BGP_MSG_UPDATE;
+
+ /* insert non-MP unfeasible routes length */
+ memcpy(data, &unreach_len, sizeof(unreach_len));
+ /* skip over it and attr_len too; it will be filled when known */
+ data += sizeof(unreach_len) + sizeof(attr_len);
+ len += sizeof(unreach_len) + sizeof(attr_len);
+
+ /* copy usual attributes */
+ memcpy(data, peer->path_attrs, peer->path_attr_len_without_nexthop);
+ data += peer->path_attr_len_without_nexthop;
+ attr_len = peer->path_attr_len_without_nexthop;
+
+ /* copy MP unreachable NLRI heading */
+ memcpy(data, peer->mp_unreach_nlri_partial,
+ BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE);
+ /* remember where to update this attr len */
+ unreach_len_pos = data + 2;
+ data += BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE;
+ attr_len += BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE;
+
+ peer->update_routes6 = 0; /* tentatively clear */
+
+ /* find differences */
+ while ((have || want) && data < (max - sizeof(struct bgp_ip6_prefix)))
+ {
+ if (have)
+ s = want
+ ? memcmp(&have->dest, &want->dest, sizeof(have->dest))
+ : -1;
+ else
+ s = 1;
+
+ if (s < 0) /* found one to delete */
+ {
+ struct bgp_route6_list *tmp = have;
+ have = have->next;
+
+ s = BGP_IP_PREFIX_SIZE(tmp->dest);
+ memcpy(data, &tmp->dest, s);
+ data += s;
+ unreach_len += s;
+ attr_len += s;
+
+ LOG(5, 0, 0, "Withdrawing route %s/%d from BGP peer %s\n",
+ inet_ntop(AF_INET6, &tmp->dest.prefix, ipv6addr, INET6_ADDRSTRLEN),
+ tmp->dest.len, peer->name);
+
+ free(tmp);
+
+ if (e)
+ e->next = have;
+ else
+ peer->routes6 = have;
+ }
+ else
+ {
+ if (!s) /* same */
+ {
+ e = have; /* stash the last found to relink above */
+ have = have->next;
+ want = want->next;
+ }
+ else if (s > 0) /* addition reqd. */
+ {
+ if (add)
+ {
+ peer->update_routes6 = 1; /* only one add per packet */
+ if (!have)
+ break;
+ }
+ else
+ add = want;
+
+ if (want)
+ want = want->next;
+ }
+ }
+ }
+
+ if (have || want)
+ peer->update_routes6 = 1; /* more to do */
+
+ /* anything changed? */
+ if (!(unreach_len || add))
+ return 1;
+
+ if (unreach_len)
+ {
+ /* go back and insert MP unreach_len */
+ unreach_len += sizeof(struct bgp_attr_mp_unreach_nlri_partial);
+ unreach_len = htons(unreach_len);
+ memcpy(unreach_len_pos, &unreach_len, sizeof(unreach_len));
+ }
+ else
+ {
+ /* we can remove this attribute, then */
+ data -= BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE;
+ attr_len -= BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE;
+ }
+
+ if (add)
+ {
+ if (!(e = malloc(sizeof(*e))))
+ {
+ LOG(0, 0, 0, "Can't allocate route for %s/%d (%s)\n",
+ inet_ntop(AF_INET6, &add->dest.prefix, ipv6addr, INET6_ADDRSTRLEN),
+ add->dest.len, strerror(errno));
+
+ return 0;
+ }
+
+ memcpy(e, add, sizeof(*e));
+ e->next = 0;
+ peer->routes6 = bgp_insert_route6(peer->routes6, e);
+
+ /* copy MP reachable NLRI heading */
+ memcpy(data, peer->mp_reach_nlri_partial,
+ BGP_PATH_ATTR_MP_REACH_NLRI_PARTIAL_SIZE);
+ /* with proper len */
+ reach_len = BGP_IP_PREFIX_SIZE(add->dest);
+ data[2] = sizeof(struct bgp_attr_mp_reach_nlri_partial) + reach_len;
+ data += BGP_PATH_ATTR_MP_REACH_NLRI_PARTIAL_SIZE;
+ attr_len += BGP_PATH_ATTR_MP_REACH_NLRI_PARTIAL_SIZE;
+
+ memcpy(data, &add->dest, reach_len);
+ data += reach_len;
+ attr_len += reach_len;
+
+ LOG(5, 0, 0, "Advertising route %s/%d to BGP peer %s\n",
+ inet_ntop(AF_INET6, &add->dest.prefix, ipv6addr, INET6_ADDRSTRLEN),
+ add->dest.len, peer->name);
+ }
+
+ /* update len with attributes we added */
+ len += attr_len;
+
+ /* go back and insert attr_len */
+ attr_len = htons(attr_len);
+ memcpy((char *)&peer->outbuf->packet.data + 2, &attr_len, sizeof(attr_len));
+
+ peer->outbuf->packet.header.len = htons(len);
+ peer->outbuf->done = 0;
+
+ return bgp_write(peer);
}
/* send/buffer NOTIFICATION message */
static int bgp_send_notification(struct bgp_peer *peer, uint8_t code,
uint8_t subcode)
-{
- return bgp_send_notification_full(peer, code, subcode, NULL, 0);
-}
-
-static int bgp_send_notification_full(struct bgp_peer *peer, uint8_t code,
- uint8_t subcode, char *notification_data, uint16_t data_len)
{
struct bgp_data_notification data;
uint16_t len = 0;
data.error_subcode = subcode;
len += sizeof(data.error_code);
- memcpy(data.data, notification_data, data_len);
- len += data_len;
-
memset(peer->outbuf->packet.header.marker, 0xff,
sizeof(peer->outbuf->packet.header.marker));
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