ipsec: ipsec-input: check for too-short packets
Make sure packet is big enough before processing it.
Policy matching is done speculatively but is discarded if packet is too
short.
Type: fix
Change-Id: I647db2c4e568b0d9bf2cfd5056e1b1c2e25132fe
Signed-off-by: Benoît Ganne <bganne@cisco.com>
diff --git a/src/vnet/ipsec/ipsec_input.c b/src/vnet/ipsec/ipsec_input.c
index 9fdbff5..61b10fb 100644
--- a/src/vnet/ipsec/ipsec_input.c
+++ b/src/vnet/ipsec/ipsec_input.c
@@ -195,6 +195,7 @@
ip4_ipsec_config_t *c0;
ipsec_spd_t *spd0;
ipsec_policy_t *p0 = 0;
+ u8 has_space0;
bi0 = to_next[0] = from[0];
from += 1;
@@ -230,8 +231,7 @@
esp0 =
(esp_header_t *) ((u8 *) esp0 + sizeof (udp_header_t));
}
- /* FIXME TODO missing check whether there is enough data inside
- * IP/UDP to contain ESP header & stuff ? */
+
p0 = ipsec_input_protect_policy_match (spd0,
clib_net_to_host_u32
(ip0->src_address.
@@ -242,7 +242,12 @@
clib_net_to_host_u32
(esp0->spi));
- if (PREDICT_TRUE (p0 != NULL))
+ has_space0 =
+ vlib_buffer_has_space (b0,
+ (clib_address_t) (esp0 + 1) -
+ (clib_address_t) ip0);
+
+ if (PREDICT_TRUE ((p0 != NULL) & (has_space0)))
{
ipsec_matched += 1;
@@ -259,6 +264,7 @@
}
else
{
+ p0 = 0;
pi0 = ~0;
};
@@ -271,10 +277,11 @@
vlib_add_trace (vm, node, b0, sizeof (*tr));
tr->proto = ip0->protocol;
- if (p0)
- tr->sa_id = p0->sa_id;
- tr->spi = clib_net_to_host_u32 (esp0->spi);
- tr->seq = clib_net_to_host_u32 (esp0->seq);
+ tr->sa_id = p0 ? p0->sa_id : ~0;
+ tr->spi =
+ has_space0 ? clib_net_to_host_u32 (esp0->spi) : ~0;
+ tr->seq =
+ has_space0 ? clib_net_to_host_u32 (esp0->seq) : ~0;
tr->spd = spd0->id;
tr->policy_index = pi0;
}
@@ -292,7 +299,12 @@
clib_net_to_host_u32
(ah0->spi));
- if (PREDICT_TRUE (p0 != 0))
+ has_space0 =
+ vlib_buffer_has_space (b0,
+ (clib_address_t) (ah0 + 1) -
+ (clib_address_t) ip0);
+
+ if (PREDICT_TRUE ((p0 != NULL) & (has_space0)))
{
ipsec_matched += 1;
@@ -308,6 +320,7 @@
}
else
{
+ p0 = 0;
pi0 = ~0;
}
/* FIXME bypass and discard */
@@ -319,10 +332,10 @@
vlib_add_trace (vm, node, b0, sizeof (*tr));
tr->proto = ip0->protocol;
- if (p0)
- tr->sa_id = p0->sa_id;
- tr->spi = clib_net_to_host_u32 (ah0->spi);
- tr->seq = clib_net_to_host_u32 (ah0->seq_no);
+ tr->sa_id = p0 ? p0->sa_id : ~0;
+ tr->spi = has_space0 ? clib_net_to_host_u32 (ah0->spi) : ~0;
+ tr->seq =
+ has_space0 ? clib_net_to_host_u32 (ah0->seq_no) : ~0;
tr->spd = spd0->id;
tr->policy_index = pi0;
}