Really fix parameters length calculation this time.

[l2tpns.git] / bgp.c

diff --git a/bgp.c b/bgp.c
index 31e6424..0566393 100644 (file)
--- a/bgp.c
+++ b/bgp.c
@@ -1555,9 +1555,9 @@ static int bgp_send_update(struct bgp_peer *peer)
 /* send/buffer UPDATE message for IPv6 routes */
 static int bgp_send_update6(struct bgp_peer *peer)
 {
-    uint16_t unf_len = 0;
     uint16_t attr_len;
-    char *unreach_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;
@@ -1580,24 +1580,24 @@ static int bgp_send_update6(struct bgp_peer *peer)
 
     peer->outbuf->packet.header.type = BGP_MSG_UPDATE;
 
-    /* insert non-MP unf_len */
-    memcpy(data, &unf_len, sizeof(unf_len));
-    /* skip over attr_len too; will be filled when known */
-    data += sizeof(unf_len) + sizeof(attr_len);
-    len += sizeof(unf_len) + sizeof(attr_len);
+    /* 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;
-    len += 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 = data + 2;
+    unreach_len_pos = data + 2;
     data += BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE;
-    len += BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE;
+    attr_len += BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE;
 
     peer->update_routes6 = 0; /* tentatively clear */
 
@@ -1619,8 +1619,8 @@ static int bgp_send_update6(struct bgp_peer *peer)
            s = BGP_IP_PREFIX_SIZE(tmp->dest);
            memcpy(data, &tmp->dest, s);
            data += s;
-           unf_len += s;
-           len += 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),
@@ -1662,21 +1662,21 @@ static int bgp_send_update6(struct bgp_peer *peer)
        peer->update_routes6 = 1; /* more to do */
 
     /* anything changed? */
-    if (!(unf_len || add))
+    if (!(unreach_len || add))
        return 1;
 
-    if (unf_len)
+    if (unreach_len)
     {
-       /* go back and insert MP unf_len */
-       unf_len += sizeof(struct bgp_attr_mp_unreach_nlri_partial);
-       unf_len = htons(unf_len);
-       memcpy(unreach_len, &unf_len, sizeof(unf_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;
-       len -= BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE;
+       attr_len -= BGP_PATH_ATTR_MP_UNREACH_NLRI_PARTIAL_SIZE;
     }
 
     if (add)
@@ -1701,20 +1701,23 @@ static int bgp_send_update6(struct bgp_peer *peer)
        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;
-       len += 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;
-       len += 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(len - 4);
-    memcpy(&peer->outbuf->packet.data + 2, &attr_len, sizeof(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;