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authorMartin Mares <mj@ucw.cz>2000-03-30 20:44:23 +0200
committerMartin Mares <mj@ucw.cz>2000-03-30 20:44:23 +0200
commit973399ae2c21b41983a35fe71657fb41351d99e6 (patch)
tree5f61b53e382e301a497fe1481704ba8e0b1bd64c /proto/bgp/packets.c
parentb552ecc4d7ddb1b960aa26b96ebea95a3af72043 (diff)
downloadbird-973399ae2c21b41983a35fe71657fb41351d99e6.tar
bird-973399ae2c21b41983a35fe71657fb41351d99e6.zip
Basic analysis of UPDATE packets.
Diffstat (limited to 'proto/bgp/packets.c')
-rw-r--r--proto/bgp/packets.c65
1 files changed, 64 insertions, 1 deletions
diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c
index e530f81..3bddbc9 100644
--- a/proto/bgp/packets.c
+++ b/proto/bgp/packets.c
@@ -215,14 +215,77 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, int len)
conn->state = BS_OPENCONFIRM;
}
+#define DECODE_PREFIX(pp, ll) do { \
+ int b = *pp++; \
+ int q; \
+ ip_addr temp; \
+ ll--; \
+ if (b > BITS_PER_IP_ADDRESS) { bgp_error(conn, 3, 10, b, 0); return; } \
+ q = (b+7) / 8; \
+ if (ll < q) goto too_small; \
+ memcpy(&temp, pp, q); \
+ pp += q; \
+ ll -= q; \
+ n.n.prefix = ipa_and(ipa_ntoh(temp), ipa_mkmask(b)); \
+ n.n.pxlen = b; \
+} while (0)
+
static void
bgp_rx_update(struct bgp_conn *conn, byte *pkt, int len)
{
+ byte *withdrawn, *attrs, *nlri;
+ int withdrawn_len, attr_len, nlri_len;
+ net n;
+ rte e;
+
+ DBG("BGP: UPDATE\n");
if (conn->state != BS_ESTABLISHED)
{ bgp_error(conn, 5, 0, conn->state, 0); return; }
bgp_start_timer(conn->hold_timer, conn->hold_time);
- DBG("BGP: UPDATE (ignored)\n");
+ /* Find parts of the packet and check sizes */
+ if (len < 23)
+ {
+ too_small:
+ bgp_error(conn, 1, 2, len, 2);
+ return;
+ }
+ withdrawn = pkt + 21;
+ withdrawn_len = get_u16(pkt + 19);
+ if (withdrawn_len + 23 > len)
+ goto too_small;
+ attrs = withdrawn + withdrawn_len + 2;
+ attr_len = get_u16(attrs - 2);
+ if (withdrawn_len + attr_len + 23 > len)
+ goto too_small;
+ nlri = attrs + attr_len;
+ nlri_len = len - withdrawn_len - attr_len - 23;
+ if (!attr_len && nlri_len)
+ goto too_small;
+ DBG("Sizes: withdrawn=%d, attrs=%d, NLRI=%d\n", withdrawn_len, attr_len, nlri_len);
+
+ /* Withdraw routes */
+ while (withdrawn_len)
+ {
+ DECODE_PREFIX(withdrawn, withdrawn_len);
+ DBG("Withdraw %I/%d\n", n.n.prefix, n.n.pxlen);
+ }
+
+ if (nlri_len)
+ {
+#if 0
+ rta *a = bgp_decode_attrs(conn, attrs, attr_len, bgp_linpool);
+ if (a)
+#endif
+ {
+ while (nlri_len)
+ {
+ DECODE_PREFIX(nlri, nlri_len);
+ DBG("Add %I/%d\n", n.n.prefix, n.n.pxlen);
+ }
+ }
+ lp_flush(bgp_linpool);
+ }
}
static void