Merge branch 'rfc4760' into fdn-mods

This commit is contained in:
Benjamin Cama 2011-07-29 13:04:31 +02:00
commit 1c898f7017
5 changed files with 627 additions and 23 deletions

556
bgp.c
View file

@ -32,8 +32,11 @@ 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_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_connect(struct bgp_peer *peer);
static int bgp_handle_connect(struct bgp_peer *peer);
@ -43,11 +46,13 @@ static int bgp_handle_input(struct bgp_peer *peer);
static int bgp_send_open(struct bgp_peer *peer);
static int bgp_send_keepalive(struct bgp_peer *peer);
static int bgp_send_update(struct bgp_peer *peer);
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 uint16_t our_as;
static struct bgp_route_list *bgp_routes = 0;
static struct bgp_route6_list *bgp_routes6 = 0;
int bgp_configured = 0;
struct bgp_peer *bgp_peers = 0;
@ -88,6 +93,7 @@ int bgp_setup(int as)
return 0;
bgp_routes = 0;
bgp_routes6 = 0;
bgp_configured = 0; /* set by bgp_start */
return 1;
@ -192,22 +198,6 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive,
ADD_ATTRIBUTE();
/* NEXT_HOP */
a.flags = BGP_PATH_ATTR_FLAG_TRANS;
a.code = BGP_PATH_ATTR_CODE_NEXT_HOP;
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));
ADD_ATTRIBUTE();
/* MULTI_EXIT_DISC */
a.flags = BGP_PATH_ATTR_FLAG_OPTIONAL;
a.code = BGP_PATH_ATTR_CODE_MULTI_EXIT_DISC;
@ -237,6 +227,25 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive,
ADD_ATTRIBUTE();
/* remember the len before adding NEXT_HOP */
peer->path_attr_len_without_nexthop = peer->path_attr_len;
/* NEXT_HOP */
a.flags = BGP_PATH_ATTR_FLAG_TRANS;
a.code = BGP_PATH_ATTR_CODE_NEXT_HOP;
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));
ADD_ATTRIBUTE();
if (!(peer->path_attrs = malloc(peer->path_attr_len)))
{
LOG(0, 0, 0, "Can't allocate path_attrs for %s (%s)\n",
@ -247,6 +256,53 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive,
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");
@ -275,6 +331,8 @@ static void bgp_clear(struct bgp_peer *peer)
bgp_free_routes(peer->routes);
peer->routes = 0;
bgp_free_routes6(peer->routes6);
peer->routes6 = 0;
peer->outbuf->packet.header.len = 0;
peer->outbuf->done = 0;
@ -382,6 +440,33 @@ static struct bgp_route_list *bgp_insert_route(struct bgp_route_list *head,
return head;
}
/* insert route6 into list; sorted */
static struct bgp_route6_list *bgp_insert_route6(struct bgp_route6_list *head,
struct bgp_route6_list *new)
{
struct bgp_route6_list *p = head;
struct bgp_route6_list *e = 0;
while (p && memcmp(&p->dest, &new->dest, sizeof(p->dest)) < 0)
{
e = p;
p = p->next;
}
if (e)
{
new->next = e->next;
e->next = new;
}
else
{
new->next = head;
head = new;
}
return head;
}
/* add route to list for peers */
/*
* Note: this doesn't do route aggregation, nor drop routes if a less
@ -434,6 +519,59 @@ int bgp_add_route(in_addr_t ip, in_addr_t mask)
return 1;
}
/* add route to list for peers */
/*
* Note: same provisions as above
*/
int bgp_add_route6(struct in6_addr ip, int prefixlen)
{
struct bgp_route6_list *r = bgp_routes6;
struct bgp_route6_list add;
int i;
char ipv6addr[INET6_ADDRSTRLEN];
memcpy(&add.dest.prefix, &ip.s6_addr, 16);
add.dest.len = prefixlen;
add.next = 0;
/* check for duplicate */
while (r)
{
i = memcmp(&r->dest, &add.dest, sizeof(r->dest));
if (!i)
return 1; /* already covered */
if (i > 0)
break;
r = r->next;
}
/* insert into route list; sorted */
if (!(r = malloc(sizeof(*r))))
{
LOG(0, 0, 0, "Can't allocate route for %s/%d (%s)\n",
inet_ntop(AF_INET6, &ip, ipv6addr, INET6_ADDRSTRLEN), add.dest.len,
strerror(errno));
return 0;
}
memcpy(r, &add, sizeof(*r));
bgp_routes6 = bgp_insert_route6(bgp_routes6, r);
/* flag established peers for update */
for (i = 0; i < BGP_NUM_PEERS; i++)
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",
inet_ntop(AF_INET6, &ip, ipv6addr, INET6_ADDRSTRLEN), add.dest.len);
return 1;
}
/* remove route from list for peers */
int bgp_del_route(in_addr_t ip, in_addr_t mask)
{
@ -483,6 +621,58 @@ int bgp_del_route(in_addr_t ip, in_addr_t mask)
return 1;
}
/* remove route from list for peers */
int bgp_del_route6(struct in6_addr ip, int prefixlen)
{
struct bgp_route6_list *r = bgp_routes6;
struct bgp_route6_list *e = 0;
struct bgp_route6_list del;
int i;
char ipv6addr[INET6_ADDRSTRLEN];
memcpy(&del.dest.prefix, &ip.s6_addr, 16);
del.dest.len = prefixlen;
del.next = 0;
/* find entry in routes list and remove */
while (r)
{
i = memcmp(&r->dest, &del.dest, sizeof(r->dest));
if (!i)
{
if (e)
e->next = r->next;
else
bgp_routes6 = r->next;
free(r);
break;
}
e = r;
if (i > 0)
r = 0; /* stop */
else
r = r->next;
}
/* not found */
if (!r)
return 1;
/* flag established peers for update */
for (i = 0; i < BGP_NUM_PEERS; i++)
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",
inet_ntop(AF_INET6, &ip, ipv6addr, INET6_ADDRSTRLEN), del.dest.len);
return 1;
}
/* enable or disable routing */
void bgp_enable_routing(int enable)
{
@ -627,6 +817,14 @@ int bgp_process(uint32_t events[])
continue;
}
/* process pending IPv6 updates */
if (peer->update_routes6
&& !peer->outbuf->packet.header.len) /* ditto */
{
if (!bgp_send_update6(peer))
continue;
}
/* process timers */
if (peer->state == Established)
{
@ -670,6 +868,17 @@ static void bgp_free_routes(struct bgp_route_list *routes)
}
}
static void bgp_free_routes6(struct bgp_route6_list *routes)
{
struct bgp_route6_list *tmp;
while ((tmp = routes))
{
routes = tmp->next;
free(tmp);
}
}
char const *bgp_state_str(enum bgp_state state)
{
switch (state)
@ -924,6 +1133,12 @@ static int bgp_handle_input(struct bgp_peer *peer)
struct bgp_data_open data;
int hold;
int i;
off_t param_offset, capability_offset;
struct bgp_opt_param *param;
uint8_t capabilities_len;
char *capabilities = NULL;
struct bgp_capability *capability;
struct bgp_mp_cap_param *mp_cap;
for (i = 0; i < sizeof(p->header.marker); i++)
{
@ -986,10 +1201,93 @@ static int bgp_handle_input(struct bgp_peer *peer)
if (peer->keepalive * 3 > peer->hold)
peer->keepalive = peer->hold / 3;
/* check for optional parameters */
/* 2 is for the size of type + len (both uint8_t) */
for (param_offset = 0;
param_offset < data.opt_len;
param_offset += 2 + param->len)
{
param = (struct bgp_opt_param *)((char *)&data.opt_params + param_offset);
/* sensible check */
if (data.opt_len - param_offset < 2
|| param->len > data.opt_len - param_offset - 2)
{
LOG(1, 0, 0, "Malformed Optional Parameter list from BGP peer %s\n",
peer->name);
bgp_send_notification(peer, BGP_ERR_OPEN, BGP_ERR_UNSPEC);
return 0;
}
/* we know only one parameter type */
if (param->type != BGP_PARAM_TYPE_CAPABILITY)
{
LOG(1, 0, 0, "Unsupported Optional Parameter type %d from BGP peer %s\n",
param->type, peer->name);
bgp_send_notification(peer, BGP_ERR_OPEN, BGP_ERR_OPN_UNSUP_PARAM);
return 0;
}
capabilities_len = param->len;
capabilities = (char *)&param->value;
/* look for BGP multiprotocol capability */
for (capability_offset = 0;
capability_offset < capabilities_len;
capability_offset += 2 + capability->len)
{
capability = (struct bgp_capability *)(capabilities + capability_offset);
/* sensible check */
if (capabilities_len - capability_offset < 2
|| capability->len > capabilities_len - capability_offset - 2)
{
LOG(1, 0, 0, "Malformed Capabilities list from BGP peer %s\n",
peer->name);
bgp_send_notification(peer, BGP_ERR_OPEN, BGP_ERR_UNSPEC);
return 0;
}
/* we only know one capability code */
if (capability->code != BGP_CAP_CODE_MP
&& capability->len != sizeof(struct bgp_mp_cap_param))
{
LOG(4, 0, 0, "Unsupported Capability code %d from BGP peer %s\n",
capability->code, peer->name);
/* 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) != 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);
/* we don't terminate, still; we just jump to the next one */
continue;
}
/* 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);
/* FIXME: may need to check for optional params */
}
break;
@ -1022,6 +1320,26 @@ static int bgp_handle_input(struct bgp_peer *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;
}
if (notification->error_code == BGP_ERR_OPEN
&& notification->error_subcode == BGP_ERR_OPN_UNSUP_CAP)
{
/* the only capability we advertise is this one, so upon receiving
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->mp_handling = DoesntHandleIPv6Routes;
break;
}
/* FIXME: should handle more notifications */
LOG(4, 0, 0, "BGP peer %s sent unhandled NOTIFICATION %d\n",
peer->name, (int) notification->error_code);
@ -1052,6 +1370,9 @@ static int bgp_handle_input(struct bgp_peer *peer)
static int bgp_send_open(struct bgp_peer *peer)
{
struct bgp_data_open data;
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);
memset(peer->outbuf->packet.header.marker, 0xff,
@ -1063,10 +1384,30 @@ static int bgp_send_open(struct bgp_peer *peer)
data.as = htons(our_as);
data.hold_time = htons(peer->hold);
data.identifier = my_address;
data.opt_len = 0;
memcpy(peer->outbuf->packet.data, &data, BGP_DATA_OPEN_SIZE);
len += BGP_DATA_OPEN_SIZE;
/* 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(&param_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, &param_cap_mp_ipv6, data.opt_len);
}
else
data.opt_len = 0;
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;
@ -1233,6 +1574,179 @@ static int bgp_send_update(struct bgp_peer *peer)
return bgp_write(peer);
}
/* 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)