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Diffstat (limited to 'proto/bgp/packets.c')
-rw-r--r--proto/bgp/packets.c60
1 files changed, 43 insertions, 17 deletions
diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c
index 1370ee70..27adc166 100644
--- a/proto/bgp/packets.c
+++ b/proto/bgp/packets.c
@@ -234,10 +234,10 @@ bgp_create_update(struct bgp_conn *conn, byte *buf)
{
struct bgp_proto *p = conn->bgp;
struct bgp_bucket *buck;
- int size, is_ll;
+ int size;
int remains = BGP_MAX_PACKET_LENGTH - BGP_HEADER_LENGTH - 4;
byte *w, *tmp, *tstart;
- ip_addr ip, ip_ll;
+ ip_addr *ipp, ip, ip_ll;
ea_list *ea;
eattr *nh;
neighbor *n;
@@ -291,26 +291,42 @@ bgp_create_update(struct bgp_conn *conn, byte *buf)
*tmp++ = 1;
nh = ea_find(buck->eattrs, EA_CODE(EAP_BGP, BA_NEXT_HOP));
ASSERT(nh);
- ip = *(ip_addr *) nh->u.ptr->data;
- is_ll = 0;
- if (ipa_equal(ip, p->local_addr))
- {
- is_ll = 1;
- ip_ll = p->local_link;
- }
+
+ /* We have two addresses here in 'nh'. Really. */
+ ipp = (ip_addr *) nh->u.ptr->data;
+ ip = ipp[0];
+ ip_ll = IPA_NONE;
+
+ if (ipa_equal(ip, p->source_addr))
+ ip_ll = p->local_link;
else
{
+ /* If we send a route with 'third party' next hop destinated
+ * in the same interface, we should also send a link local
+ * next hop address. We use the received one (stored in the
+ * other part of BA_NEXT_HOP eattr). If we didn't received
+ * it (for example it is a static route), we can't use
+ * 'third party' next hop and we have to use local IP address
+ * as next hop. Sending original next hop address without
+ * link local address seems to be a natural way to solve that
+ * problem, but it is contrary to RFC 2545 and Quagga does not
+ * accept such routes.
+ */
+
n = neigh_find(&p->p, &ip, 0);
if (n && n->iface == p->neigh->iface)
{
- /* FIXME: We are assuming the global scope addresses use the lower 64 bits
- * as an interface identifier which hasn't necessarily to be true.
- */
- is_ll = 1;
- ip_ll = ipa_or(ipa_build(0xfe800000,0,0,0), ipa_and(ip, ipa_build(0,0,~0,~0)));
+ if (ipa_nonzero(ipp[1]))
+ ip_ll = ipp[1];
+ else
+ {
+ ip = p->source_addr;
+ ip_ll = p->local_link;
+ }
}
}
- if (is_ll)
+
+ if (ipa_nonzero(ip_ll))
{
*tmp++ = 32;
ipa_hton(ip);
@@ -326,6 +342,7 @@ bgp_create_update(struct bgp_conn *conn, byte *buf)
memcpy(tmp, &ip, 16);
tmp += 16;
}
+
*tmp++ = 0; /* No SNPA information */
tmp += bgp_encode_prefixes(p, tmp, buck, remains - (8+3+32+1));
ea->attrs[0].u.ptr->length = tmp - tstart;
@@ -778,9 +795,18 @@ bgp_do_rx_update(struct bgp_conn *conn,
if (len < 1 || (*x != 16 && *x != 32) || len < *x + 2)
goto bad;
- byte *nh = bgp_attach_attr_wa(&a0->eattrs, bgp_linpool, BA_NEXT_HOP, 16);
+ ip_addr *nh = (ip_addr *) bgp_attach_attr_wa(&a0->eattrs, bgp_linpool, BA_NEXT_HOP, NEXT_HOP_LENGTH);
memcpy(nh, x+1, 16);
- ipa_ntoh(*(ip_addr *)nh);
+ ipa_ntoh(nh[0]);
+
+ /* We store received link local address in the other part of BA_NEXT_HOP eattr. */
+ if (*x == 32)
+ {
+ memcpy(nh+1, x+17, 16);
+ ipa_ntoh(nh[1]);
+ }
+ else
+ nh[1] = IPA_NONE;
/* Also ignore one reserved byte */
len -= *x + 2;