Add Multiprotocol definitions and more param handling.
[l2tpns.git] / bgp.c
diff --git a/bgp.c b/bgp.c
index cf8ab7e..9d237c9 100644 (file)
--- a/bgp.c
+++ b/bgp.c
@@ -10,7 +10,7 @@
  *   nor RFC2385 (which requires a kernel patch on 2.4 kernels).
  */
 
-char const *cvs_id_bgp = "$Id: bgp.c,v 1.8 2004/11/29 02:17:17 bodea Exp $";
+char const *cvs_id_bgp = "$Id: bgp.c,v 1.12 2005/09/02 23:39:36 bodea Exp $";
 
 #include <stdlib.h>
 #include <unistd.h>
@@ -34,7 +34,7 @@ static struct bgp_route_list *bgp_insert_route(struct bgp_route_list *head,
     struct bgp_route_list *new);
 
 static void bgp_free_routes(struct bgp_route_list *routes);
-static char const *bgp_msg_type_str(u8 type);
+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);
 static int bgp_write(struct bgp_peer *peer);
@@ -43,9 +43,12 @@ 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_notification(struct bgp_peer *peer, u8 code, u8 subcode);
+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 u16 our_as;
+static uint16_t our_as;
 static struct bgp_route_list *bgp_routes = 0;
 
 int bgp_configured = 0;
@@ -74,6 +77,10 @@ int bgp_setup(int as)
 
            return 0;
        }
+
+       peer->edata.type = FD_TYPE_BGP;
+       peer->edata.index = i;
+       peer->events = 0;
     }
 
     if (as < 1)
@@ -89,7 +96,8 @@ int bgp_setup(int as)
 }
 
 /* start connection with a peer */
-int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, int hold, int enable)
+int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive,
+    int hold, int enable)
 {
     struct hostent *h;
     int ibgp;
@@ -98,8 +106,8 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, int hold
     char path_attrs[64];
     char *p = path_attrs;
     in_addr_t ip;
-    u32 metric = htonl(BGP_METRIC);
-    u32 no_export = htonl(BGP_COMMUNITY_NO_EXPORT);
+    uint32_t metric = htonl(BGP_METRIC);
+    uint32_t no_export = htonl(BGP_COMMUNITY_NO_EXPORT);
 
     if (!our_as)
        return 0;
@@ -170,9 +178,9 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, int hold
     {
        /* just our AS */
        struct {
-           u8 type;
-           u8 len;
-           u16 value;
+           uint8_t type;
+           uint8_t len;
+           uint16_t value;
        } as_path = {
            BGP_PATH_ATTR_CODE_AS_PATH_AS_SEQUENCE,
            1,
@@ -204,7 +212,7 @@ int bgp_start(struct bgp_peer *peer, char *name, int as, int keepalive, int hold
 
     if (ibgp)
     {
-       u32 local_pref = htonl(BGP_LOCAL_PREF);
+       uint32_t local_pref = htonl(BGP_LOCAL_PREF);
 
        /* LOCAL_PREF */
        a.flags = BGP_PATH_ATTR_FLAG_TRANS;
@@ -268,6 +276,7 @@ static void bgp_clear(struct bgp_peer *peer)
     peer->inbuf->done = 0;
 
     peer->cli_flag = 0;
+    peer->events = 0;
 
     if (peer->state != peer->next_state)
     {
@@ -324,7 +333,7 @@ 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)
 {
     int i;
-    u32 b;
+    uint32_t b;
 
     /* convert to prefix notation */
     pfx->len = 32;
@@ -485,130 +494,160 @@ void bgp_enable_routing(int enable)
     LOG(4, 0, 0, "%s BGP routing\n", enable ? "Enabled" : "Suspended");
 }
 
-/* return a bitmask indicating if the socket should be added to the
-   read set (1) and or write set (2) for select */
-int bgp_select_state(struct bgp_peer *peer)
+#ifdef HAVE_EPOLL
+# include <sys/epoll.h>
+#else
+# include "fake_epoll.h"
+#endif
+
+/* return a bitmask of the events required to poll this peer's fd */
+int bgp_set_poll()
 {
-    int flags = 0;
+    int i;
 
     if (!bgp_configured)
        return 0;
 
-    if (peer->state == Disabled || peer->state == Idle)
-       return 0;
+    for (i = 0; i < BGP_NUM_PEERS; i++)
+    {
+       struct bgp_peer *peer = &bgp_peers[i];
+       int events = 0;
 
-    if (peer->inbuf->done < BGP_MAX_PACKET_SIZE)
-       flags |= 1;
+       if (peer->state == Disabled || peer->state == Idle)
+           continue;
 
-    if (peer->state == Connect ||              /* connection in progress */
-       peer->update_routes ||                  /* routing updates */
-       peer->outbuf->packet.header.len)        /* pending output */
-       flags |= 2;
+       if (peer->inbuf->done < BGP_MAX_PACKET_SIZE)
+           events |= EPOLLIN;
+
+       if (peer->state == Connect ||           /* connection in progress */
+           peer->update_routes ||              /* routing updates */
+           peer->outbuf->packet.header.len)    /* pending output */
+           events |= EPOLLOUT;
+
+       if (peer->events != events)
+       {
+           struct epoll_event ev;
+
+           ev.events = peer->events = events;
+           ev.data.ptr = &peer->edata;
+           epoll_ctl(epollfd, EPOLL_CTL_MOD, peer->sock, &ev);
+       }
+    }
 
-    return flags;
+    return 1;
 }
 
-/* process bgp peer */
-int bgp_process(struct bgp_peer *peer, int readable, int writable)
+/* process bgp events/timers */
+int bgp_process(uint32_t events[])
 {
+    int i;
+
     if (!bgp_configured)
        return 0;
 
-    if (*peer->name && peer->cli_flag == BGP_CLI_RESTART)
-       return bgp_restart(peer);
+    for (i = 0; i < BGP_NUM_PEERS; i++)
+    {
+       struct bgp_peer *peer = &bgp_peers[i];
 
-    if (peer->state == Disabled)
-       return 1;
+       if (*peer->name && peer->cli_flag == BGP_CLI_RESTART)
+       {
+           bgp_restart(peer);
+           continue;
+       }
 
-    if (peer->cli_flag)
-    {
-       switch (peer->cli_flag)
+       if (peer->state == Disabled)
+           continue;
+
+       if (peer->cli_flag)
        {
-       case BGP_CLI_SUSPEND:
-           if (peer->routing)
+           switch (peer->cli_flag)
            {
-               peer->routing = 0;
-               if (peer->state == Established)
-                   peer->update_routes = 1;
-           }
+           case BGP_CLI_SUSPEND:
+               if (peer->routing)
+               {
+                   peer->routing = 0;
+                   if (peer->state == Established)
+                       peer->update_routes = 1;
+               }
 
-           break;
+               break;
 
-       case BGP_CLI_ENABLE:
-           if (!peer->routing)
-           {
-               peer->routing = 1;
-               if (peer->state == Established)
-                   peer->update_routes = 1;
+           case BGP_CLI_ENABLE:
+               if (!peer->routing)
+               {
+                   peer->routing = 1;
+                   if (peer->state == Established)
+                       peer->update_routes = 1;
+               }
+
+               break;
            }
 
-           break;
+           peer->cli_flag = 0;
        }
 
-       peer->cli_flag = 0;
-    }
-
-    /* handle empty/fill of buffers */
-    if (writable)
-    {
-       int r = 1;
-       if (peer->state == Connect)
-           r = bgp_handle_connect(peer);
-       else if (peer->outbuf->packet.header.len)
-           r = bgp_write(peer);
+       /* handle empty/fill of buffers */
+       if (events[i] & EPOLLOUT)
+       {
+           int r = 1;
+           if (peer->state == Connect)
+               r = bgp_handle_connect(peer);
+           else if (peer->outbuf->packet.header.len)
+               r = bgp_write(peer);
 
-       if (!r)
-           return 0;
-    }
+           if (!r)
+               continue;
+       }
 
-    if (readable)
-    {
-       if (!bgp_read(peer))
-           return 0;
-    }
+       if (events[i] & (EPOLLIN|EPOLLHUP))
+       {
+           if (!bgp_read(peer))
+               continue;
+       }
 
-    /* process input buffer contents */
-    while (peer->inbuf->done >= sizeof(peer->inbuf->packet.header)
-       && !peer->outbuf->packet.header.len) /* may need to queue a response */
-    {
-       if (bgp_handle_input(peer) < 0)
-           return 0;
-    }
+       /* process input buffer contents */
+       while (peer->inbuf->done >= sizeof(peer->inbuf->packet.header)
+           && !peer->outbuf->packet.header.len) /* may need to queue a response */
+       {
+           if (bgp_handle_input(peer) < 0)
+               continue;
+       }
 
-    /* process pending updates */
-    if (peer->update_routes
-       && !peer->outbuf->packet.header.len) /* ditto */
-    {
-       if (!bgp_send_update(peer))
-           return 0;
-    }
+       /* process pending updates */
+       if (peer->update_routes
+           && !peer->outbuf->packet.header.len) /* ditto */
+       {
+           if (!bgp_send_update(peer))
+               continue;
+       }
 
-    /* process timers */
-    if (peer->state == Established)
-    {
-       if (time_now > peer->expire_time)
+       /* process timers */
+       if (peer->state == Established)
        {
-           LOG(1, 0, 0, "No message from BGP peer %s in %ds\n",
-               peer->name, peer->hold);
+           if (time_now > peer->expire_time)
+           {
+               LOG(1, 0, 0, "No message from BGP peer %s in %ds\n",
+                   peer->name, peer->hold);
 
-           bgp_send_notification(peer, BGP_ERR_HOLD_TIMER_EXP, 0);
-           return 0;
-       }
+               bgp_send_notification(peer, BGP_ERR_HOLD_TIMER_EXP, 0);
+               continue;
+           }
 
-       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)
-           return 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);
+           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 bgp_restart(peer);
+           bgp_restart(peer);
+       }
     }
 
     return 1;
@@ -641,7 +680,7 @@ char const *bgp_state_str(enum bgp_state state)
     return "?";
 }
 
-static char const *bgp_msg_type_str(u8 type)
+static char const *bgp_msg_type_str(uint8_t type)
 {
     switch (type)
     {
@@ -659,6 +698,7 @@ static int bgp_connect(struct bgp_peer *peer)
 {
     static int bgp_port = 0;
     struct sockaddr_in addr;
+    struct epoll_event ev;
 
     if (!bgp_port)
     {
@@ -681,6 +721,11 @@ static int bgp_connect(struct bgp_peer *peer)
        return 0;
     }
 
+    /* add to poll set */
+    ev.events = peer->events = EPOLLOUT;
+    ev.data.ptr = &peer->edata;
+    epoll_ctl(epollfd, EPOLL_CTL_ADD, peer->sock, &ev);
+
     /* set to non-blocking */
     fcntl(peer->sock, F_SETFL, fcntl(peer->sock, F_GETFL, 0) | O_NONBLOCK);
 
@@ -724,7 +769,7 @@ static int bgp_connect(struct bgp_peer *peer)
 static int bgp_handle_connect(struct bgp_peer *peer)
 {
     int err = 0;
-    int len = sizeof(int);
+    socklen_t len = sizeof(int);
     getsockopt(peer->sock, SOL_SOCKET, SO_ERROR, &err, &len);
     if (err)
     {
@@ -859,6 +904,12 @@ 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++)
            {
@@ -921,10 +972,90 @@ 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 *)(&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_CAPABILITY_PARAM_TYPE)
+               {
+                   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 */
+           if (capabilities)
+           {
+               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);
+
+                       bgp_send_notification_full(peer, BGP_ERR_OPEN, BGP_ERR_OPN_UNSUP_CAP,
+                               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 (mp_cap->afi != AF_INET6 && 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,
+                               capability, 2 + capability->len);
+                       /* we don't terminate, still; we just jump to the next one */
+                       continue;
+                   }
+
+               }
+           }
+
            /* next transition requires an exchange of keepalives */
            bgp_send_keepalive(peer);
-
-           /* FIXME: may need to check for optional params */
        }
 
        break;
@@ -953,7 +1084,7 @@ static int bgp_handle_input(struct bgp_peer *peer)
            if (notification->error_code == BGP_ERR_CEASE)
            {
                LOG(4, 0, 0, "BGP peer %s sent CEASE\n", peer->name);
-               bgp_halt(peer);
+               bgp_restart(peer);
                return 0;
            }
 
@@ -987,7 +1118,7 @@ static int bgp_handle_input(struct bgp_peer *peer)
 static int bgp_send_open(struct bgp_peer *peer)
 {
     struct bgp_data_open data;
-    u16 len = sizeof(peer->outbuf->packet.header);
+    uint16_t len = sizeof(peer->outbuf->packet.header);
 
     memset(peer->outbuf->packet.header.marker, 0xff,
        sizeof(peer->outbuf->packet.header.marker));
@@ -1029,9 +1160,9 @@ static int bgp_send_keepalive(struct bgp_peer *peer)
 /* send/buffer UPDATE message */
 static int bgp_send_update(struct bgp_peer *peer)
 {
-    u16 unf_len = 0;
-    u16 attr_len;
-    u16 len = sizeof(peer->outbuf->packet.header);
+    uint16_t unf_len = 0;
+    uint16_t attr_len;
+    uint16_t len = sizeof(peer->outbuf->packet.header);
     struct bgp_route_list *have = peer->routes;
     struct bgp_route_list *want = peer->routing ? bgp_routes : 0;
     struct bgp_route_list *e = 0;
@@ -1169,10 +1300,17 @@ static int bgp_send_update(struct bgp_peer *peer)
 }
 
 /* send/buffer NOTIFICATION message */
-static int bgp_send_notification(struct bgp_peer *peer, u8 code, u8 subcode)
+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;
-    u16 len = 0;
+    uint16_t len = 0;
 
     data.error_code = code;
     len += sizeof(data.error_code);
@@ -1180,6 +1318,9 @@ static int bgp_send_notification(struct bgp_peer *peer, u8 code, u8 subcode)
     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));