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authorArthur de Kerhor <arthurdekerhor@gmail.com>2023-06-16 09:48:52 +0200
committerBeno�t Ganne <bganne@cisco.com>2023-12-12 09:02:03 +0000
commit8fce5463707e38c14320d2d0f49cd5ec32dc791e (patch)
tree650b45c296b1eb3a3605b61d65d82aa74ad57ea5 /src/vnet/ipsec
parentb321325a47993a87c3550a34082fba91b3dd817d (diff)
ipsec: allow receiving encrypted IP packets with TFC padding
Type: feature Change-Id: I7b29c71d3d053af9a53931aa333484bf43a424ca Signed-off-by: Arthur de Kerhor <arthurdekerhor@gmail.com> Signed-off-by: Benoît Ganne <bganne@cisco.com>
Diffstat (limited to 'src/vnet/ipsec')
-rw-r--r--src/vnet/ipsec/esp_decrypt.c46
1 files changed, 42 insertions, 4 deletions
diff --git a/src/vnet/ipsec/esp_decrypt.c b/src/vnet/ipsec/esp_decrypt.c
index 7b74e6e2c67..fba4549048d 100644
--- a/src/vnet/ipsec/esp_decrypt.c
+++ b/src/vnet/ipsec/esp_decrypt.c
@@ -161,6 +161,9 @@ esp_remove_tail (vlib_main_t * vm, vlib_buffer_t * b, vlib_buffer_t * last,
{
vlib_buffer_t *before_last = b;
+ if (b != last)
+ b->total_length_not_including_first_buffer -= tail;
+
if (last->current_length > tail)
{
last->current_length -= tail;
@@ -178,6 +181,37 @@ esp_remove_tail (vlib_main_t * vm, vlib_buffer_t * b, vlib_buffer_t * last,
before_last->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
}
+always_inline void
+esp_remove_tail_and_tfc_padding (vlib_main_t *vm, vlib_node_runtime_t *node,
+ const esp_decrypt_packet_data_t *pd,
+ vlib_buffer_t *b, vlib_buffer_t *last,
+ u16 *next, u16 tail, int is_ip6)
+{
+ const u16 total_buffer_length = vlib_buffer_length_in_chain (vm, b);
+ u16 ip_packet_length;
+ if (is_ip6)
+ {
+ const ip6_header_t *ip6 = vlib_buffer_get_current (b);
+ ip_packet_length =
+ clib_net_to_host_u16 (ip6->payload_length) + sizeof (ip6_header_t);
+ }
+ else
+ {
+ const ip4_header_t *ip4 = vlib_buffer_get_current (b);
+ ip_packet_length = clib_net_to_host_u16 (ip4->length);
+ }
+ /* In case of TFC padding, the size of the buffer data needs to be adjusted
+ * to the ip packet length */
+ if (PREDICT_FALSE (total_buffer_length < ip_packet_length + tail))
+ {
+ esp_decrypt_set_next_index (b, node, vm->thread_index,
+ ESP_DECRYPT_ERROR_NO_TAIL_SPACE, 0, next,
+ ESP_DECRYPT_NEXT_DROP, pd->sa_index);
+ return;
+ }
+ esp_remove_tail (vm, b, last, total_buffer_length - ip_packet_length);
+}
+
/* ICV is splitted in last two buffers so move it to the last buffer and
return pointer to it */
static_always_inline u8 *
@@ -203,9 +237,12 @@ esp_move_icv (vlib_main_t * vm, vlib_buffer_t * first,
before_last->current_length -= first_sz;
if (before_last == first)
pd->current_length -= first_sz;
+ else
+ first->total_length_not_including_first_buffer -= first_sz;
clib_memset (vlib_buffer_get_tail (before_last), 0, first_sz);
if (dif)
dif[0] = first_sz;
+ first->total_length_not_including_first_buffer -= last_sz;
pd2->lb = before_last;
pd2->icv_removed = 1;
pd2->free_buffer_index = before_last->next_buffer;
@@ -857,8 +894,7 @@ esp_decrypt_post_crypto (vlib_main_t *vm, vlib_node_runtime_t *node,
u16 tail = sizeof (esp_footer_t) + pad_length + icv_sz;
u16 tail_orig = sizeof (esp_footer_t) + pad_length + pd->icv_sz;
b->flags &=
- ~(VLIB_BUFFER_TOTAL_LENGTH_VALID | VNET_BUFFER_F_L4_CHECKSUM_COMPUTED |
- VNET_BUFFER_F_L4_CHECKSUM_CORRECT);
+ ~(VNET_BUFFER_F_L4_CHECKSUM_COMPUTED | VNET_BUFFER_F_L4_CHECKSUM_CORRECT);
if ((pd->flags & tun_flags) == 0 && !is_tun) /* transport mode */
{
@@ -908,14 +944,16 @@ esp_decrypt_post_crypto (vlib_main_t *vm, vlib_node_runtime_t *node,
next[0] = ESP_DECRYPT_NEXT_IP4_INPUT;
b->current_data = pd->current_data + adv;
b->current_length = pd->current_length - adv;
- esp_remove_tail (vm, b, lb, tail);
+ esp_remove_tail_and_tfc_padding (vm, node, pd, b, lb, next, tail,
+ false);
}
else if (next_header == IP_PROTOCOL_IPV6)
{
next[0] = ESP_DECRYPT_NEXT_IP6_INPUT;
b->current_data = pd->current_data + adv;
b->current_length = pd->current_length - adv;
- esp_remove_tail (vm, b, lb, tail);
+ esp_remove_tail_and_tfc_padding (vm, node, pd, b, lb, next, tail,
+ true);
}
else if (next_header == IP_PROTOCOL_MPLS_IN_IP)
{