s = format (s, "%s(%d): ", h->name, t->t);
- for (i = 0; i < (t->l - sizeof (*t)); i++)
- vec_add1 (s, t->v[i]);
+ if (t->l >= 4)
+ {
+ for (i = 0; i < (t->l - sizeof (*t)); i++)
+ vec_add1 (s, t->v[i]);
+ }
vec_add1 (s, '\n');
return s;
static int
cdp_packet_scan (cdp_main_t * cm, cdp_neighbor_t * n)
{
- u8 *cur = n->last_rx_pkt;
+ u8 *end, *cur = n->last_rx_pkt;
cdp_hdr_t *h;
cdp_tlv_t *tlv;
cdp_error_t e = CDP_ERROR_NONE;
if (e)
return e;
+ // there are no tlvs
+ if (vec_len (n->last_rx_pkt) <= 0)
+ return CDP_ERROR_BAD_TLV;
+
cur = (u8 *) (h + 1);
+ end = n->last_rx_pkt + vec_len (n->last_rx_pkt) - 1;
- while (cur < n->last_rx_pkt + vec_len (n->last_rx_pkt) - 1)
+ // look ahead 4 bytes (u16 tlv->t + u16 tlv->l)
+ while (cur + 3 <= end)
{
tlv = (cdp_tlv_t *) cur;
tlv->t = ntohs (tlv->t);
tlv->l = ntohs (tlv->l);
+
+ /* tlv length includes t, l and v */
+
+ if (tlv->l < 4)
+ return CDP_ERROR_BAD_TLV;
+
+ cur += tlv->l;
+ if ((cur - 1) > end)
+ return CDP_ERROR_BAD_TLV;
+
/*
* Only process known TLVs. In practice, certain
* devices send tlv->t = 0xFF, perhaps as an EOF of sorts.
if (e)
return e;
}
- /* tlv length includes (t, l) */
- cur += tlv->l;
}
+ // did not process all tlvs or none tlv processed
+ if ((cur - 1) != end)
+ return CDP_ERROR_BAD_TLV;
+
return CDP_ERROR_NONE;
}
if (p == 0)
{
pool_get (cm->neighbors, n);
- memset (n, 0, sizeof (*n));
+ clib_memset (n, 0, sizeof (*n));
n->sw_if_index = vnet_buffer (b0)->sw_if_index[VLIB_RX];
n->packet_template_index = (u8) ~ 0;
hash_set (cm->neighbor_by_sw_if_index, n->sw_if_index,