ipsec: fix chained ESP
This fixes a special case when buffer chain enters decrypt node
and becomes a single buffer after decryption.
Type: fix
Change-Id: Id5da9e8a074f83ec3561949631ce613f35528312
Signed-off-by: Filip Tehlar <ftehlar@cisco.com>
diff --git a/src/vnet/ipsec/esp_decrypt.c b/src/vnet/ipsec/esp_decrypt.c
index 3668948..80b3246 100644
--- a/src/vnet/ipsec/esp_decrypt.c
+++ b/src/vnet/ipsec/esp_decrypt.c
@@ -214,7 +214,7 @@
return pointer to it */
static_always_inline u8 *
esp_move_icv (vlib_main_t * vm, vlib_buffer_t * first,
- esp_decrypt_packet_data_t * pd, u16 icv_sz)
+ esp_decrypt_packet_data_t * pd, u16 icv_sz, u16 * dif)
{
vlib_buffer_t *before_last, *bp;
u16 last_sz = pd->lb->current_length;
@@ -232,6 +232,8 @@
clib_memcpy_fast (lb_curr, vlib_buffer_get_tail (before_last) - first_sz,
first_sz);
before_last->current_length -= first_sz;
+ if (dif)
+ dif[0] = first_sz;
pd->lb = before_last;
pd->icv_removed = 1;
pd->free_buffer_index = before_last->next_buffer;
@@ -239,6 +241,76 @@
return lb_curr;
}
+static_always_inline int
+esp_insert_esn (vlib_main_t * vm, ipsec_sa_t * sa,
+ esp_decrypt_packet_data_t * pd, vnet_crypto_op_t * op,
+ u16 * len, vlib_buffer_t * b, u8 * payload)
+{
+ if (!ipsec_sa_is_set_USE_ESN (sa))
+ return 1;
+
+ /* shift ICV by 4 bytes to insert ESN */
+ u32 seq_hi = clib_host_to_net_u32 (sa->seq_hi);
+ u8 tmp[ESP_MAX_ICV_SIZE], sz = sizeof (sa->seq_hi);
+
+ if (pd->icv_removed)
+ {
+ u16 space_left = vlib_buffer_space_left_at_end (vm, pd->lb);
+ if (space_left >= sz)
+ {
+ clib_memcpy_fast (vlib_buffer_get_tail (pd->lb), &seq_hi, sz);
+ op->len += sz;
+ }
+ else
+ return 0;
+
+ len[0] = b->current_length;
+ }
+ else
+ {
+ clib_memcpy_fast (tmp, payload + len[0], ESP_MAX_ICV_SIZE);
+ clib_memcpy_fast (payload + len[0], &seq_hi, sz);
+ clib_memcpy_fast (payload + len[0] + sz, tmp, ESP_MAX_ICV_SIZE);
+ op->len += sz;
+ op->digest += sz;
+ }
+ return 1;
+}
+
+static_always_inline u8 *
+esp_move_icv_esn (vlib_main_t * vm, vlib_buffer_t * first,
+ esp_decrypt_packet_data_t * pd, u16 icv_sz, ipsec_sa_t * sa,
+ u8 * extra_esn, vnet_crypto_op_t * op)
+{
+ u16 dif = 0;
+ u8 *digest = esp_move_icv (vm, first, pd, icv_sz, &dif);
+ if (dif)
+ op->len -= dif;
+
+ if (ipsec_sa_is_set_USE_ESN (sa))
+ {
+ u8 sz = sizeof (sa->seq_hi);
+ u32 seq_hi = clib_host_to_net_u32 (sa->seq_hi);
+ u16 space_left = vlib_buffer_space_left_at_end (vm, pd->lb);
+
+ if (space_left >= sz)
+ {
+ clib_memcpy_fast (vlib_buffer_get_tail (pd->lb), &seq_hi, sz);
+ op->len += sz;
+ }
+ else
+ {
+ /* no space for ESN at the tail, use the next buffer
+ * (with ICV data) */
+ ASSERT (pd->icv_removed);
+ vlib_buffer_t *tmp = vlib_get_buffer (vm, pd->free_buffer_index);
+ clib_memcpy_fast (vlib_buffer_get_current (tmp) - sz, &seq_hi, sz);
+ extra_esn[0] = 1;
+ }
+ }
+ return digest;
+}
+
always_inline uword
esp_decrypt_inline (vlib_main_t * vm,
vlib_node_runtime_t * node, vlib_frame_t * from_frame,
@@ -246,7 +318,6 @@
{
ipsec_main_t *im = &ipsec_main;
u32 thread_index = vm->thread_index;
- u16 buffer_data_size = vlib_buffer_get_default_data_size (vm);
u16 len;
ipsec_per_thread_data_t *ptd = vec_elt_at_index (im->ptd, thread_index);
u32 *from = vlib_frame_vector_args (from_frame);
@@ -258,6 +329,7 @@
u32 current_sa_index = ~0, current_sa_bytes = 0, current_sa_pkts = 0;
const u8 esp_sz = sizeof (esp_header_t);
ipsec_sa_t *sa0 = 0;
+ vnet_crypto_op_t _op, *op = &_op;
vnet_crypto_op_chunk_t *ch;
vnet_crypto_op_t **crypto_ops = &ptd->crypto_ops;
vnet_crypto_op_t **integ_ops = &ptd->integ_ops;
@@ -327,7 +399,6 @@
/* store packet data for next round for easier prefetch */
pd->sa_data = cpd.sa_data;
pd->current_data = b[0]->current_data;
- pd->current_length = b[0]->current_length;
pd->hdr_sz = pd->current_data - vnet_buffer (b[0])->l3_hdr_offset;
payload = b[0]->data + pd->current_data;
pd->seq = clib_host_to_net_u32 (((esp_header_t *) payload)->seq);
@@ -346,17 +417,6 @@
}
pd->current_length = b[0]->current_length;
- /* we need 4 extra bytes for HMAC calculation when ESN are used */
- /* Chained buffers can process ESN as a separate chunk */
- if (pd->lb == b[0] && ipsec_sa_is_set_USE_ESN (sa0) && cpd.icv_sz &&
- (pd->lb->current_data + pd->lb->current_length + 4
- > buffer_data_size))
- {
- b[0]->error = node->errors[ESP_DECRYPT_ERROR_NO_TAIL_SPACE];
- next[0] = ESP_DECRYPT_NEXT_DROP;
- goto next;
- }
-
/* anti-reply check */
if (ipsec_sa_anti_replay_check (sa0, pd->seq))
{
@@ -378,9 +438,6 @@
if (PREDICT_TRUE (sa0->integ_op_id != VNET_CRYPTO_OP_NONE))
{
- vnet_crypto_op_t *op;
- vec_add2_aligned (integ_ops[0], op, 1, CLIB_CACHE_LINE_BYTES);
-
vnet_crypto_op_init (op, sa0->integ_op_id);
op->key_index = sa0->integ_key_index;
op->src = payload;
@@ -394,14 +451,43 @@
{
/* buffer is chained */
vlib_buffer_t *cb = b[0];
- op->flags |= VNET_CRYPTO_OP_FLAG_CHAINED_BUFFERS;
- op->chunk_index = vec_len (ptd->chunks);
+ op->len = pd->current_length;
+ /* special case when ICV is splitted and needs to be reassembled
+ * first -> move it to the last buffer. Also take into account
+ * that ESN needs to be added after encrypted data and may or
+ * may not fit in the tail.*/
if (pd->lb->current_length < cpd.icv_sz)
- op->digest = esp_move_icv (vm, b[0], pd, cpd.icv_sz);
+ {
+ u8 extra_esn = 0;
+ op->digest =
+ esp_move_icv_esn (vm, b[0], pd, cpd.icv_sz, sa0,
+ &extra_esn, op);
+
+ if (extra_esn)
+ {
+ /* esn is in the last buffer, that was unlinked from
+ * the chain */
+ op->len = b[0]->current_length;
+ }
+ else
+ {
+ if (pd->lb == b[0])
+ {
+ /* we now have a single buffer of crypto data, adjust
+ * the length (second buffer contains only ICV) */
+ integ_ops = &ptd->integ_ops;
+ crypto_ops = &ptd->crypto_ops;
+ len = b[0]->current_length;
+ goto out;
+ }
+ }
+ }
else
op->digest = vlib_buffer_get_tail (pd->lb) - cpd.icv_sz;
+ op->flags |= VNET_CRYPTO_OP_FLAG_CHAINED_BUFFERS;
+ op->chunk_index = vec_len (ptd->chunks);
vec_add2 (ptd->chunks, ch, 1);
ch->len = pd->current_length;
ch->src = payload;
@@ -472,6 +558,7 @@
ch->len += sz;
}
}
+ break;
}
else
ch->len = cb->current_length;
@@ -482,17 +569,10 @@
cb = vlib_get_buffer (vm, cb->next_buffer);
}
}
- else if (ipsec_sa_is_set_USE_ESN (sa0))
- {
- /* shift ICV by 4 bytes to insert ESN */
- u32 seq_hi = clib_host_to_net_u32 (sa0->seq_hi);
- u8 tmp[ESP_MAX_ICV_SIZE], sz = sizeof (sa0->seq_hi);
- clib_memcpy_fast (tmp, payload + len, ESP_MAX_ICV_SIZE);
- clib_memcpy_fast (payload + len, &seq_hi, sz);
- clib_memcpy_fast (payload + len + sz, tmp, ESP_MAX_ICV_SIZE);
- op->len += sz;
- op->digest += sz;
- }
+ else
+ esp_insert_esn (vm, sa0, pd, op, &len, b[0], payload);
+ out:
+ vec_add_aligned (integ_ops[0], op, 1, CLIB_CACHE_LINE_BYTES);
}
payload += esp_sz;
@@ -500,8 +580,6 @@
if (sa0->crypto_dec_op_id != VNET_CRYPTO_OP_NONE)
{
- vnet_crypto_op_t *op;
- vec_add2_aligned (crypto_ops[0], op, 1, CLIB_CACHE_LINE_BYTES);
vnet_crypto_op_init (op, sa0->crypto_dec_op_id);
op->key_index = sa0->crypto_key_index;
op->iv = payload;
@@ -562,8 +640,9 @@
{
if (pd->lb->current_length < cpd.icv_sz)
{
+ u16 dif = 0;
op->tag =
- esp_move_icv (vm, b[0], pd, cpd.icv_sz);
+ esp_move_icv (vm, b[0], pd, cpd.icv_sz, &dif);
/* this chunk does not contain crypto data */
op->n_chunks -= 1;
@@ -571,7 +650,10 @@
/* and fix previous chunk's length as it might have
been changed */
ASSERT (op->n_chunks > 0);
- ch[-1].len = pd->lb->current_length;
+ if (pd->lb == b[0])
+ ch[-1].len -= dif;
+ else
+ ch[-1].len = pd->lb->current_length;
break;
}
else
@@ -593,6 +675,8 @@
cb = vlib_get_buffer (vm, cb->next_buffer);
}
}
+
+ vec_add_aligned (crypto_ops[0], op, 1, CLIB_CACHE_LINE_BYTES);
}
/* next */
@@ -743,7 +827,7 @@
clib_memcpy_le64 (ip, old_ip, ip_hdr_sz);
b[0]->current_data = pd->current_data + adv - ip_hdr_sz;
- b[0]->current_length = pd->current_length + ip_hdr_sz - adv;
+ b[0]->current_length += ip_hdr_sz - adv;
esp_remove_tail (vm, b[0], pd->lb, tail);
if (is_ip6)
diff --git a/src/vnet/ipsec/esp_encrypt.c b/src/vnet/ipsec/esp_encrypt.c
index 4793fdd..e40d30d 100644
--- a/src/vnet/ipsec/esp_encrypt.c
+++ b/src/vnet/ipsec/esp_encrypt.c
@@ -44,7 +44,6 @@
_(SEQ_CYCLED, "sequence number cycled (packet dropped)") \
_(CRYPTO_ENGINE_ERROR, "crypto engine error (packet dropped)") \
_(NO_BUFFERS, "no buffers (packet dropped)") \
- _(NO_TRAILER_SPACE, "no trailer space (packet dropped)")
typedef enum
{
@@ -91,7 +90,8 @@
/* pad packet in input buffer */
static_always_inline u8 *
-esp_add_footer_and_icv (vlib_buffer_t * b, u8 block_size, u8 icv_sz,
+esp_add_footer_and_icv (vlib_main_t * vm, vlib_buffer_t ** last,
+ u8 block_size, u8 icv_sz,
u16 * next, vlib_node_runtime_t * node,
u16 buffer_data_size, uword total_len)
{
@@ -103,18 +103,27 @@
u16 min_length = total_len + sizeof (esp_footer_t);
u16 new_length = round_pow2 (min_length, block_size);
u8 pad_bytes = new_length - min_length;
- esp_footer_t *f = (esp_footer_t *) (vlib_buffer_get_current (b) +
- b->current_length + pad_bytes);
+ esp_footer_t *f = (esp_footer_t *) (vlib_buffer_get_current (last[0]) +
+ last[0]->current_length + pad_bytes);
u16 tail_sz = sizeof (esp_footer_t) + pad_bytes + icv_sz;
- if (b->current_data + tail_sz > buffer_data_size)
+ if (last[0]->current_length + tail_sz > buffer_data_size)
{
- // TODO alloc new buffer
- b->error = node->errors[ESP_ENCRYPT_ERROR_NO_TRAILER_SPACE];
- next[0] = ESP_ENCRYPT_NEXT_DROP;
- return 0;
- }
+ u32 tmp_bi = 0;
+ if (vlib_buffer_alloc (vm, &tmp_bi, 1) != 1)
+ return 0;
+ vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
+ last[0]->next_buffer = tmp_bi;
+ last[0]->flags |= VLIB_BUFFER_NEXT_PRESENT;
+ f = (esp_footer_t *) (vlib_buffer_get_current (tmp) + pad_bytes);
+ tmp->current_length += tail_sz;
+ last[0] = tmp;
+ }
+ else
+ last[0]->current_length += tail_sz;
+
+ f->pad_length = pad_bytes;
if (pad_bytes)
{
ASSERT (pad_bytes <= ESP_MAX_BLOCK_SIZE);
@@ -122,8 +131,6 @@
clib_memcpy_fast ((u8 *) f - pad_bytes, pad_data, pad_bytes);
}
- f->pad_length = pad_bytes;
- b->current_length += tail_sz;
return &f->next_header;
}
@@ -402,13 +409,17 @@
if (ipsec_sa_is_set_IS_TUNNEL (sa0))
{
payload = vlib_buffer_get_current (b[0]);
- next_hdr_ptr = esp_add_footer_and_icv (lb, block_sz, icv_sz,
+ next_hdr_ptr = esp_add_footer_and_icv (vm, &lb, block_sz, icv_sz,
next, node,
buffer_data_size,
vlib_buffer_length_in_chain
(vm, b[0]));
if (!next_hdr_ptr)
- goto trace;
+ {
+ b[0]->error = node->errors[ESP_ENCRYPT_ERROR_NO_BUFFERS];
+ next[0] = ESP_ENCRYPT_NEXT_DROP;
+ goto trace;
+ }
b[0]->flags &= ~VLIB_BUFFER_TOTAL_LENGTH_VALID;
payload_len = b[0]->current_length;
payload_len_total = vlib_buffer_length_in_chain (vm, b[0]);
@@ -472,7 +483,7 @@
vlib_buffer_advance (b[0], ip_len);
payload = vlib_buffer_get_current (b[0]);
- next_hdr_ptr = esp_add_footer_and_icv (lb, block_sz, icv_sz,
+ next_hdr_ptr = esp_add_footer_and_icv (vm, &lb, block_sz, icv_sz,
next, node,
buffer_data_size,
vlib_buffer_length_in_chain