| /* |
| * 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: |
| */ |