diff options
Diffstat (limited to 'src/vnet/ipsec/ah_decrypt.c')
| -rw-r--r-- | src/vnet/ipsec/ah_decrypt.c | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/src/vnet/ipsec/ah_decrypt.c b/src/vnet/ipsec/ah_decrypt.c new file mode 100644 index 00000000000..c487d82e34a --- /dev/null +++ b/src/vnet/ipsec/ah_decrypt.c @@ -0,0 +1,343 @@ +/* + * ah_decrypt.c : IPSec AH decrypt node + * + * Copyright (c) 2015 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <vnet/vnet.h> +#include <vnet/api_errno.h> +#include <vnet/ip/ip.h> + +#include <vnet/ipsec/ipsec.h> +#include <vnet/ipsec/esp.h> +#include <vnet/ipsec/ah.h> + +#define foreach_ah_decrypt_next \ +_(DROP, "error-drop") \ +_(IP4_INPUT, "ip4-input") \ +_(IP6_INPUT, "ip6-input") \ +_(IPSEC_GRE_INPUT, "ipsec-gre-input") + +#define _(v, s) AH_DECRYPT_NEXT_##v, +typedef enum +{ + foreach_ah_decrypt_next +#undef _ + AH_DECRYPT_N_NEXT, +} ah_decrypt_next_t; + + +#define foreach_ah_decrypt_error \ + _(RX_PKTS, "AH pkts received") \ + _(DECRYPTION_FAILED, "AH decryption failed") \ + _(INTEG_ERROR, "Integrity check failed") \ + _(REPLAY, "SA replayed packet") \ + _(NOT_IP, "Not IP packet (dropped)") + + +typedef enum +{ +#define _(sym,str) AH_DECRYPT_ERROR_##sym, + foreach_ah_decrypt_error +#undef _ + AH_DECRYPT_N_ERROR, +} ah_decrypt_error_t; + +static char *ah_decrypt_error_strings[] = { +#define _(sym,string) string, + foreach_ah_decrypt_error +#undef _ +}; + +typedef struct +{ + ipsec_integ_alg_t integ_alg; +} ah_decrypt_trace_t; + +/* packet trace format function */ +static u8 * +format_ah_decrypt_trace (u8 * s, va_list * args) +{ + CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *); + CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *); + ah_decrypt_trace_t *t = va_arg (*args, ah_decrypt_trace_t *); + + s = format (s, "ah: integrity %U", format_ipsec_integ_alg, t->integ_alg); + return s; +} + +static uword +ah_decrypt_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, vlib_frame_t * from_frame) +{ + u32 n_left_from, *from, next_index, *to_next; + ipsec_main_t *im = &ipsec_main; + ipsec_proto_main_t *em = &ipsec_proto_main; + from = vlib_frame_vector_args (from_frame); + n_left_from = from_frame->n_vectors; + int icv_size = 0; + + next_index = node->cached_next_index; + + while (n_left_from > 0) + { + u32 n_left_to_next; + + vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next); + + while (n_left_from > 0 && n_left_to_next > 0) + { + u32 i_bi0; + u32 next0; + vlib_buffer_t *i_b0; + ah_header_t *ah0; + ipsec_sa_t *sa0; + u32 sa_index0 = ~0; + u32 seq; + ip4_header_t *ih4 = 0, *oh4 = 0; + ip6_header_t *ih6 = 0, *oh6 = 0; + u8 tunnel_mode = 1; + u8 transport_ip6 = 0; + u8 ip_hdr_size = 0; + u8 tos = 0; + u8 ttl = 0; + + + i_bi0 = from[0]; + from += 1; + n_left_from -= 1; + n_left_to_next -= 1; + + next0 = AH_DECRYPT_NEXT_DROP; + + i_b0 = vlib_get_buffer (vm, i_bi0); + to_next[0] = i_bi0; + to_next += 1; + ih4 = vlib_buffer_get_current (i_b0); + ip_hdr_size = ip4_header_bytes (ih4); + ah0 = (ah_header_t *) ((u8 *) ih4 + ip_hdr_size); + + sa_index0 = vnet_buffer (i_b0)->ipsec.sad_index; + sa0 = pool_elt_at_index (im->sad, sa_index0); + + seq = clib_host_to_net_u32 (ah0->seq_no); + /* anti-replay check */ + //TODO UT remaining + if (sa0->use_anti_replay) + { + int rv = 0; + + if (PREDICT_TRUE (sa0->use_esn)) + rv = esp_replay_check_esn (sa0, seq); + else + rv = esp_replay_check (sa0, seq); + + if (PREDICT_FALSE (rv)) + { + clib_warning ("anti-replay SPI %u seq %u", sa0->spi, seq); + vlib_node_increment_counter (vm, ah_decrypt_node.index, + AH_DECRYPT_ERROR_REPLAY, 1); + to_next[0] = i_bi0; + to_next += 1; + goto trace; + } + } + + + sa0->total_data_size += i_b0->current_length; + icv_size = + em->ipsec_proto_main_integ_algs[sa0->integ_alg].trunc_size; + if (PREDICT_TRUE (sa0->integ_alg != IPSEC_INTEG_ALG_NONE)) + { + u8 sig[64]; + u8 digest[64]; + memset (sig, 0, sizeof (sig)); + memset (digest, 0, sizeof (digest)); + u8 *icv = + vlib_buffer_get_current (i_b0) + ip_hdr_size + + sizeof (ah_header_t); + memcpy (digest, icv, icv_size); + memset (icv, 0, icv_size); + + if ((ih4->ip_version_and_header_length & 0xF0) == 0x40) + { + tos = ih4->tos; + ttl = ih4->ttl; + ih4->tos = 0; + ih4->ttl = 0; + ih4->checksum = 0; + ih4->flags_and_fragment_offset = 0; + } //TODO else part for IPv6 + hmac_calc (sa0->integ_alg, sa0->integ_key, sa0->integ_key_len, + (u8 *) ih4, i_b0->current_length, sig, sa0->use_esn, + sa0->seq_hi); + + if (PREDICT_FALSE (memcmp (digest, sig, icv_size))) + { + vlib_node_increment_counter (vm, ah_decrypt_node.index, + AH_DECRYPT_ERROR_INTEG_ERROR, + 1); + to_next[0] = i_bi0; + to_next += 1; + goto trace; + } + + //TODO UT remaining + if (PREDICT_TRUE (sa0->use_anti_replay)) + { + if (PREDICT_TRUE (sa0->use_esn)) + esp_replay_advance_esn (sa0, seq); + else + esp_replay_advance (sa0, seq); + } + + } + + + vlib_buffer_advance (i_b0, + ip_hdr_size + sizeof (ah_header_t) + icv_size); + i_b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID; + + /* transport mode */ + if (PREDICT_FALSE (!sa0->is_tunnel && !sa0->is_tunnel_ip6)) + { + tunnel_mode = 0; + + if (PREDICT_TRUE + ((ih4->ip_version_and_header_length & 0xF0) != 0x40)) + { + if (PREDICT_TRUE + ((ih4->ip_version_and_header_length & 0xF0) == 0x60)) + transport_ip6 = 1; + else + { + clib_warning ("next header: 0x%x", ah0->nexthdr); + vlib_node_increment_counter (vm, ah_decrypt_node.index, + AH_DECRYPT_ERROR_NOT_IP, + 1); + goto trace; + } + } + } + + if (PREDICT_TRUE (tunnel_mode)) + { + if (PREDICT_TRUE (ah0->nexthdr == IP_PROTOCOL_IP_IN_IP)) + next0 = AH_DECRYPT_NEXT_IP4_INPUT; + else if (ah0->nexthdr == IP_PROTOCOL_IPV6) + next0 = AH_DECRYPT_NEXT_IP6_INPUT; + else + { + clib_warning ("next header: 0x%x", ah0->nexthdr); + vlib_node_increment_counter (vm, ah_decrypt_node.index, + AH_DECRYPT_ERROR_DECRYPTION_FAILED, + 1); + goto trace; + } + } + /* transport mode */ + else + { + if (PREDICT_FALSE (transport_ip6)) + { + ih6 = + (ip6_header_t *) (i_b0->data + + sizeof (ethernet_header_t)); + vlib_buffer_advance (i_b0, -sizeof (ip6_header_t)); + oh6 = vlib_buffer_get_current (i_b0); + memmove (oh6, ih6, sizeof (ip6_header_t)); + + next0 = AH_DECRYPT_NEXT_IP6_INPUT; + oh6->protocol = ah0->nexthdr; + oh6->payload_length = + clib_host_to_net_u16 (vlib_buffer_length_in_chain + (vm, i_b0) - sizeof (ip6_header_t)); + } + else + { + vlib_buffer_advance (i_b0, -sizeof (ip4_header_t)); + oh4 = vlib_buffer_get_current (i_b0); + memmove (oh4, ih4, sizeof (ip4_header_t)); + + next0 = AH_DECRYPT_NEXT_IP4_INPUT; + oh4->ip_version_and_header_length = 0x45; + oh4->fragment_id = 0; + oh4->flags_and_fragment_offset = 0; + oh4->protocol = ah0->nexthdr; + oh4->length = + clib_host_to_net_u16 (vlib_buffer_length_in_chain + (vm, i_b0)); + oh4->ttl = ttl; + oh4->tos = tos; + oh4->checksum = ip4_header_checksum (oh4); + } + } + + /* for IPSec-GRE tunnel next node is ipsec-gre-input */ + if (PREDICT_FALSE + ((vnet_buffer (i_b0)->ipsec.flags) & + IPSEC_FLAG_IPSEC_GRE_TUNNEL)) + next0 = AH_DECRYPT_NEXT_IPSEC_GRE_INPUT; + + + vnet_buffer (i_b0)->sw_if_index[VLIB_TX] = (u32) ~ 0; + trace: + if (PREDICT_FALSE (i_b0->flags & VLIB_BUFFER_IS_TRACED)) + { + i_b0->flags |= VLIB_BUFFER_IS_TRACED; + ah_decrypt_trace_t *tr = + vlib_add_trace (vm, node, i_b0, sizeof (*tr)); + tr->integ_alg = sa0->integ_alg; + } + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, + n_left_to_next, i_bi0, next0); + } + vlib_put_next_frame (vm, node, next_index, n_left_to_next); + } + vlib_node_increment_counter (vm, ah_decrypt_node.index, + AH_DECRYPT_ERROR_RX_PKTS, + from_frame->n_vectors); + + return from_frame->n_vectors; +} + + +/* *INDENT-OFF* */ +VLIB_REGISTER_NODE (ah_decrypt_node) = { + .function = ah_decrypt_node_fn, + .name = "ah-decrypt", + .vector_size = sizeof (u32), + .format_trace = format_ah_decrypt_trace, + .type = VLIB_NODE_TYPE_INTERNAL, + + .n_errors = ARRAY_LEN(ah_decrypt_error_strings), + .error_strings = ah_decrypt_error_strings, + + .n_next_nodes = AH_DECRYPT_N_NEXT, + .next_nodes = { +#define _(s,n) [AH_DECRYPT_NEXT_##s] = n, + foreach_ah_decrypt_next +#undef _ + }, +}; +/* *INDENT-ON* */ + +VLIB_NODE_FUNCTION_MULTIARCH (ah_decrypt_node, ah_decrypt_node_fn) +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |