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authorKlement Sekera <ksekera@cisco.com>2021-07-27 13:33:51 +0200
committerOle Tr�an <otroan@employees.org>2021-07-29 08:23:23 +0000
commit254c803612c0c9ec5dfc1b90de6efb23ec5bedd5 (patch)
tree5bac561399f5845c04bbe73438154f525fdc3345 /src
parentb2d36784ac6689e323017a6adb9fc284aae01e13 (diff)
nat: fix ICMP checksum validation
Handle case where extra data is present in buffer which is not part of IP/ICMP headers. Type: fix Fixes: 05b5a5b3b4b04823776feed6403b5a99b2e06d76 Change-Id: Icfef811470056d38c60fc45cc302139ed7594385 Signed-off-by: Klement Sekera <ksekera@cisco.com>
Diffstat (limited to 'src')
-rw-r--r--src/plugins/nat/nat44-ed/nat44_ed.c18
1 files changed, 9 insertions, 9 deletions
diff --git a/src/plugins/nat/nat44-ed/nat44_ed.c b/src/plugins/nat/nat44-ed/nat44_ed.c
index 4e13907a9d8..8ad971decea 100644
--- a/src/plugins/nat/nat44-ed/nat44_ed.c
+++ b/src/plugins/nat/nat44-ed/nat44_ed.c
@@ -3694,15 +3694,6 @@ nat_6t_flow_icmp_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
return NAT_ED_TRNSL_ERR_PACKET_TRUNCATED;
}
- ssize_t icmp_offset = (u8 *) icmp - (u8 *) vlib_buffer_get_current (b);
- ip_csum_t sum =
- ip_incremental_checksum (0, icmp, b->current_length - icmp_offset);
- sum = (u16) ~ip_csum_fold (sum);
- if (sum != 0)
- {
- return NAT_ED_TRNSL_ERR_INVALID_CSUM;
- }
-
if (!icmp_type_is_error_message (icmp->type))
{
if ((f->ops & NAT_FLOW_OP_ICMP_ID_REWRITE) &&
@@ -3718,6 +3709,15 @@ nat_6t_flow_icmp_translate (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
}
else
{
+ ip_csum_t sum = ip_incremental_checksum (
+ 0, icmp,
+ clib_net_to_host_u16 (ip->length) - ip4_header_bytes (ip));
+ sum = (u16) ~ip_csum_fold (sum);
+ if (sum != 0)
+ {
+ return NAT_ED_TRNSL_ERR_INVALID_CSUM;
+ }
+
// errors are not fragmented
ip4_header_t *inner_ip = (ip4_header_t *) (echo + 1);