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-rw-r--r--proto/bgp/packets.c234
1 files changed, 198 insertions, 36 deletions
diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c
index 52e9351..45397fb 100644
--- a/proto/bgp/packets.c
+++ b/proto/bgp/packets.c
@@ -68,6 +68,8 @@ bgp_encode_prefixes(struct bgp_proto *p, byte *w, struct bgp_bucket *buck, unsig
return w - start;
}
+#ifndef IPV6 /* IPv4 version */
+
static byte *
bgp_create_update(struct bgp_conn *conn, byte *buf)
{
@@ -117,6 +119,16 @@ bgp_create_update(struct bgp_conn *conn, byte *buf)
return (wd_size || r_size) ? w : NULL;
}
+#else /* IPv6 version */
+
+static byte *
+bgp_create_update(struct bgp_conn *conn, byte *buf)
+{
+ return NULL;
+}
+
+#endif
+
static void
bgp_create_header(byte *buf, unsigned int len, unsigned int type)
{
@@ -321,9 +333,9 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, int len)
int b = *pp++; \
int q; \
ll--; \
- if (b > BITS_PER_IP_ADDRESS) { bgp_error(conn, 3, 10, NULL, 0); return; } \
+ if (b > BITS_PER_IP_ADDRESS) { err=10; goto bad; } \
q = (b+7) / 8; \
- if (ll < q) goto malformed; \
+ if (ll < q) { err=1; goto bad; } \
memcpy(&prefix, pp, q); \
pp += q; \
ll -= q; \
@@ -332,42 +344,40 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, int len)
pxlen = b; \
} while (0)
+static inline int
+bgp_get_nexthop(struct bgp_proto *bgp, rta *a)
+{
+ neighbor *neigh;
+ ip_addr nexthop;
+ struct eattr *nh = ea_find(a->eattrs, EA_CODE(EAP_BGP, BA_NEXT_HOP));
+ ASSERT(nh);
+ nexthop = *(ip_addr *) nh->u.ptr->data;
+ if (ipa_equal(nexthop, bgp->local_addr))
+ {
+ DBG("BGP: Loop!\n");
+ return 0;
+ }
+ neigh = neigh_find(&bgp->p, &nexthop, 0) ? : bgp->neigh;
+ a->gw = neigh->addr;
+ a->iface = neigh->iface;
+ return 1;
+}
+
+#ifndef IPV6 /* IPv4 version */
+
static void
-bgp_rx_update(struct bgp_conn *conn, byte *pkt, int len)
+bgp_do_rx_update(struct bgp_conn *conn,
+ byte *withdrawn, int withdrawn_len,
+ byte *nlri, int nlri_len,
+ byte *attrs, int attr_len)
{
struct bgp_proto *p = conn->bgp;
- byte *withdrawn, *attrs, *nlri;
+ rta *a0;
+ rta *a = NULL;
ip_addr prefix;
- int withdrawn_len, attr_len, nlri_len, pxlen;
net *n;
rte e;
- rta *a0;
- rta *a = NULL;
-
- BGP_TRACE(D_PACKETS, "Got UPDATE");
- if (conn->state != BS_ESTABLISHED)
- { bgp_error(conn, 5, 0, NULL, 0); return; }
- bgp_start_timer(conn->hold_timer, conn->hold_time);
-
- /* Find parts of the packet and check sizes */
- if (len < 23)
- {
- bgp_error(conn, 1, 2, pkt+16, 2);
- return;
- }
- withdrawn = pkt + 21;
- withdrawn_len = get_u16(pkt + 19);
- if (withdrawn_len + 23 > len)
- goto malformed;
- attrs = withdrawn + withdrawn_len + 2;
- attr_len = get_u16(attrs - 2);
- if (withdrawn_len + attr_len + 23 > len)
- goto malformed;
- nlri = attrs + attr_len;
- nlri_len = len - withdrawn_len - attr_len - 23;
- if (!attr_len && nlri_len)
- goto malformed;
- DBG("Sizes: withdrawn=%d, attrs=%d, NLRI=%d\n", withdrawn_len, attr_len, nlri_len);
+ int err = 0, pxlen;
/* Withdraw routes */
while (withdrawn_len)
@@ -382,7 +392,7 @@ bgp_rx_update(struct bgp_conn *conn, byte *pkt, int len)
return;
a0 = bgp_decode_attrs(conn, attrs, attr_len, bgp_linpool, nlri_len);
- if (a0 && nlri_len)
+ if (a0 && nlri_len && bgp_get_nexthop(p, a0))
{
a = rta_lookup(a0);
while (nlri_len)
@@ -396,14 +406,166 @@ bgp_rx_update(struct bgp_conn *conn, byte *pkt, int len)
e->pflags = 0;
rte_update(p->p.table, n, &p->p, e);
}
- rta_free(a);
}
- lp_flush(bgp_linpool);
+bad:
+ if (a)
+ rta_free(a);
+ if (err)
+ bgp_error(conn, 3, err, NULL, 0);
return;
+}
-malformed:
+#else /* IPv6 version */
+
+#define DO_NLRI(name) \
+ start = x = p->name##_start; \
+ len = len0 = p->name##_len; \
+ if (len) \
+ { \
+ if (len < 3) goto bad; \
+ af = get_u16(x); \
+ sub = x[2]; \
+ x += 3; \
+ len -= 3; \
+ DBG("\tNLRI AF=%d sub=%d len=%d\n", af, sub, len);\
+ } \
+ else \
+ af = 0; \
+ if (af == BGP_AF_IPV6)
+
+static void
+bgp_do_rx_update(struct bgp_conn *conn,
+ byte *withdrawn, int withdrawn_len,
+ byte *nlri, int nlri_len,
+ byte *attrs, int attr_len)
+{
+ struct bgp_proto *p = conn->bgp;
+ byte *start, *x;
+ int len, len0;
+ unsigned af, sub;
+ rta *a0;
+ rta *a = NULL;
+ ip_addr prefix;
+ net *n;
+ rte e;
+ int err = 0, pxlen;
+
+ p->mp_reach_len = 0;
+ p->mp_unreach_len = 0;
+ a0 = bgp_decode_attrs(conn, attrs, attr_len, bgp_linpool, 0);
+ if (!a0)
+ return;
+
+ DO_NLRI(mp_unreach)
+ {
+ while (len)
+ {
+ DECODE_PREFIX(x, len);
+ DBG("Withdraw %I/%d\n", prefix, pxlen);
+ if (n = net_find(p->p.table, prefix, pxlen))
+ rte_update(p->p.table, n, &p->p, NULL);
+ }
+ }
+
+ DO_NLRI(mp_reach)
+ {
+ ea_list *e = lp_alloc(bgp_linpool, sizeof(ea_list) + sizeof(eattr));
+ struct adata *ad = lp_alloc(bgp_linpool, sizeof(struct adata) + 16);
+ int i;
+
+ /* Create fake NEXT_HOP attribute */
+ if (len < 1 || (*x != 16 && *x != 32) || len < *x + 2)
+ goto bad;
+ e->next = a0->eattrs;
+ a0->eattrs = e;
+ e->flags = EALF_SORTED;
+ e->count = 1;
+ e->attrs[0].id = EA_CODE(EAP_BGP, BA_NEXT_HOP);
+ e->attrs[0].flags = BAF_TRANSITIVE;
+ e->attrs[0].type = EAF_TYPE_IP_ADDRESS;
+ e->attrs[0].u.ptr = ad;
+ ad->length = 16;
+ memcpy(ad->data, x+1, 16);
+ len -= *x + 1;
+ x += *x + 1;
+
+ /* Ignore SNPA info */
+ i = *x++;
+ while (i--)
+ {
+ if (len < 1 || len < 1 + *x)
+ goto bad;
+ len -= *x + 1;
+ x += *x + 1;
+ }
+
+ if (bgp_get_nexthop(p, a0))
+ {
+ a = rta_lookup(a0);
+ while (len)
+ {
+ rte *e;
+ DECODE_PREFIX(x, len);
+ DBG("Add %I/%d\n", prefix, pxlen);
+ e = rte_get_temp(rta_clone(a));
+ n = net_get(p->p.table, prefix, pxlen);
+ e->net = n;
+ e->pflags = 0;
+ rte_update(p->p.table, n, &p->p, e);
+ }
+ rta_free(a);
+ }
+ }
+
+ return;
+
+bad:
+ bgp_error(conn, 3, 9, start, len0);
if (a)
rta_free(a);
+ return;
+}
+
+#endif
+
+static void
+bgp_rx_update(struct bgp_conn *conn, byte *pkt, int len)
+{
+ struct bgp_proto *p = conn->bgp;
+ byte *withdrawn, *attrs, *nlri;
+ int withdrawn_len, attr_len, nlri_len;
+
+ BGP_TRACE(D_PACKETS, "Got UPDATE");
+ if (conn->state != BS_ESTABLISHED)
+ { bgp_error(conn, 5, 0, NULL, 0); return; }
+ bgp_start_timer(conn->hold_timer, conn->hold_time);
+
+ /* Find parts of the packet and check sizes */
+ if (len < 23)
+ {
+ bgp_error(conn, 1, 2, pkt+16, 2);
+ return;
+ }
+ withdrawn = pkt + 21;
+ withdrawn_len = get_u16(pkt + 19);
+ if (withdrawn_len + 23 > len)
+ goto malformed;
+ attrs = withdrawn + withdrawn_len + 2;
+ attr_len = get_u16(attrs - 2);
+ if (withdrawn_len + attr_len + 23 > len)
+ goto malformed;
+ nlri = attrs + attr_len;
+ nlri_len = len - withdrawn_len - attr_len - 23;
+ if (!attr_len && nlri_len)
+ goto malformed;
+ DBG("Sizes: withdrawn=%d, attrs=%d, NLRI=%d\n", withdrawn_len, attr_len, nlri_len);
+
+ lp_flush(bgp_linpool);
+
+ bgp_do_rx_update(conn, withdrawn, withdrawn_len, nlri, nlri_len, attrs, attr_len);
+ return;
+
+malformed:
bgp_error(conn, 3, 1, NULL, 0);
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-05 02:48:46 +0100