/* * esp_decrypt.c : IPSec ESP 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/l2/l2_input.h> #include <vnet/ipsec/ipsec.h> #include <vnet/ipsec/esp.h> #include <vnet/ipsec/ipsec_io.h> #include <vnet/ipsec/ipsec_tun.h> #include <vnet/gre/gre.h> #define foreach_esp_decrypt_next \ _(DROP, "error-drop") \ _(IP4_INPUT, "ip4-input-no-checksum") \ _(IP6_INPUT, "ip6-input") \ _(L2_INPUT, "l2-input") \ _(HANDOFF, "handoff") #define _(v, s) ESP_DECRYPT_NEXT_##v, typedef enum { foreach_esp_decrypt_next #undef _ ESP_DECRYPT_N_NEXT, } esp_decrypt_next_t; #define foreach_esp_decrypt_error \ _(RX_PKTS, "ESP pkts received") \ _(DECRYPTION_FAILED, "ESP decryption failed") \ _(INTEG_ERROR, "Integrity check failed") \ _(CRYPTO_ENGINE_ERROR, "crypto engine error (packet dropped)") \ _(REPLAY, "SA replayed packet") \ _(RUNT, "undersized packet") \ _(NO_BUFFERS, "no buffers (packet dropped)") \ _(OVERSIZED_HEADER, "buffer with oversized header (dropped)") \ _(NO_TAIL_SPACE, "no enough buffer tail space (dropped)") \ _(TUN_NO_PROTO, "no tunnel protocol") \ _(UNSUP_PAYLOAD, "unsupported payload") \ typedef enum { #define _(sym,str) ESP_DECRYPT_ERROR_##sym, foreach_esp_decrypt_error #undef _ ESP_DECRYPT_N_ERROR, } esp_decrypt_error_t; static char *esp_decrypt_error_strings[] = { #define _(sym,string) string, foreach_esp_decrypt_error #undef _ }; typedef struct { u32 seq; u32 sa_seq; u32 sa_seq_hi; ipsec_crypto_alg_t crypto_alg; ipsec_integ_alg_t integ_alg; } esp_decrypt_trace_t; /* packet trace format function */ static u8 * format_esp_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 *); esp_decrypt_trace_t *t = va_arg (*args, esp_decrypt_trace_t *); s = format (s, "esp: crypto %U integrity %U pkt-seq %d sa-seq %u sa-seq-hi %u", format_ipsec_crypto_alg, t->crypto_alg, format_ipsec_integ_alg, t->integ_alg, t->seq, t->sa_seq, t->sa_seq_hi); return s; } typedef struct { vlib_buffer_t *lb; union { struct { u8 icv_sz; u8 iv_sz; ipsec_sa_flags_t flags; u32 sa_index; }; u64 sa_data; }; u32 seq; u32 free_buffer_index; i16 current_data; i16 current_length; u16 hdr_sz; u8 icv_removed; u8 __unused; } esp_decrypt_packet_data_t; STATIC_ASSERT_SIZEOF (esp_decrypt_packet_data_t, 4 * sizeof (u64)); #define ESP_ENCRYPT_PD_F_FD_TRANSPORT (1 << 2) static_always_inline void esp_process_ops (vlib_main_t * vm, vlib_node_runtime_t * node, vnet_crypto_op_t * ops, vlib_buffer_t * b[], u16 * nexts, int e) { vnet_crypto_op_t *op = ops; u32 n_fail, n_ops = vec_len (ops); if (n_ops == 0) return; n_fail = n_ops - vnet_crypto_process_ops (vm, op, n_ops); while (n_fail) { ASSERT (op - ops < n_ops); if (op->status != VNET_CRYPTO_OP_STATUS_COMPLETED) { u32 err, bi = op->user_data; if (op->status == VNET_CRYPTO_OP_STATUS_FAIL_BAD_HMAC) err = e; else err = ESP_DECRYPT_ERROR_CRYPTO_ENGINE_ERROR; b[bi]->error = node->errors[err]; nexts[bi] = ESP_DECRYPT_NEXT_DROP; n_fail--; } op++; } } static_always_inline void esp_process_chained_ops (vlib_main_t * vm, vlib_node_runtime_t * node, vnet_crypto_op_t * ops, vlib_buffer_t * b[], u16 * nexts, vnet_crypto_op_chunk_t * chunks, int e) { vnet_crypto_op_t *op = ops; u32 n_fail, n_ops = vec_len (ops); if (n_ops == 0) return; n_fail = n_ops - vnet_crypto_process_chained_ops (vm, op, chunks, n_ops); while (n_fail) { ASSERT (op - ops < n_ops); if (op->status != VNET_CRYPTO_OP_STATUS_COMPLETED) { u32 err, bi = op->user_data; if (op->status == VNET_CRYPTO_OP_STATUS_FAIL_BAD_HMAC) err = e; else err = ESP_DECRYPT_ERROR_CRYPTO_ENGINE_ERROR; b[bi]->error = node->errors[err]; nexts[bi] = ESP_DECRYPT_NEXT_DROP; n_fail--; } op++; } } always_inline void esp_remove_tail (vlib_main_t * vm, vlib_buffer_t * b, vlib_buffer_t * last, u16 tail) { vlib_buffer_t *before_last = b; if (last->current_length > tail) { last->current_length -= tail; return; } ASSERT (b->flags & VLIB_BUFFER_NEXT_PRESENT); while (b->flags & VLIB_BUFFER_NEXT_PRESENT) { before_last = b; b = vlib_get_buffer (vm, b->next_buffer); } before_last->current_length -= tail - last->current_length; vlib_buffer_free_one (vm, before_last->next_buffer); before_last->flags &= ~VLIB_BUFFER_NEXT_PRESENT; } /* ICV is splitted in last two buffers so move it to the last buffer and 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, u16 * dif) { vlib_buffer_t *before_last, *bp; u16 last_sz = pd->lb->current_length; u16 first_sz = icv_sz - last_sz; bp = before_last = first; while (bp->flags & VLIB_BUFFER_NEXT_PRESENT) { before_last = bp; bp = vlib_get_buffer (vm, bp->next_buffer); } u8 *lb_curr = vlib_buffer_get_current (pd->lb); memmove (lb_curr + first_sz, lb_curr, last_sz); 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; before_last->flags &= ~VLIB_BUFFER_NEXT_PRESENT; 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, int is_ip6, int is_tun) { ipsec_main_t *im = &ipsec_main; u32 thread_index = vm->thread_index; u16 len; ipsec_per_thread_data_t *ptd = vec_elt_at_index (im->ptd, thread_index); u32 *from = vlib_frame_vector_args (from_frame); u32 n_left = from_frame->n_vectors; vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b = bufs; u16 nexts[VLIB_FRAME_SIZE], *next = nexts; esp_decrypt_packet_data_t pkt_data[VLIB_FRAME_SIZE], *pd = pkt_data; esp_decrypt_packet_data_t cpd = { }; 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; vlib_get_buffers (vm, from, b, n_left); vec_reset_length (ptd->crypto_ops); vec_reset_length (ptd->integ_ops); vec_reset_length (ptd->chained_crypto_ops); vec_reset_length (ptd->chained_integ_ops); vec_reset_length (ptd->chunks); clib_memset_u16 (nexts, -1, n_left); while (n_left > 0) { u8 *payload; if (n_left > 2) { u8 *p; vlib_prefetch_buffer_header (b[2], LOAD); p = vlib_buffer_get_current (b[1]); CLIB_PREFETCH (p, CLIB_CACHE_LINE_BYTES, LOAD); p -= CLIB_CACHE_LINE_BYTES; CLIB_PREFETCH (p, CLIB_CACHE_LINE_BYTES, LOAD); } u32 n_bufs = vlib_buffer_chain_linearize (vm, b[0]); if (n_bufs == 0) { b[0]->error = node->errors[ESP_DECRYPT_ERROR_NO_BUFFERS]; next[0] = ESP_DECRYPT_NEXT_DROP; goto next; } if (vnet_buffer (b[0])->ipsec.sad_index != current_sa_index) { if (current_sa_pkts) vlib_increment_combined_counter (&ipsec_sa_counters, thread_index, current_sa_index, current_sa_pkts, current_sa_bytes); current_sa_bytes = current_sa_pkts = 0; current_sa_index = vnet_buffer (b[0])->ipsec.sad_index; sa0 = pool_elt_at_index (im->sad, current_sa_index); cpd.icv_sz = sa0->integ_icv_size; cpd.iv_sz = sa0->crypto_iv_size; cpd.flags = sa0->flags; cpd.sa_index = current_sa_index; } if (PREDICT_FALSE (~0 == sa0->decrypt_thread_index)) { /* this is the first packet to use this SA, claim the SA * for this thread. this could happen simultaneously on * another thread */ clib_atomic_cmp_and_swap (&sa0->decrypt_thread_index, ~0, ipsec_sa_assign_thread (thread_index)); } if (PREDICT_TRUE (thread_index != sa0->decrypt_thread_index)) { next[0] = ESP_DECRYPT_NEXT_HANDOFF; goto next; } /* store packet data for next round for easier prefetch */ pd->sa_data = cpd.sa_data; pd->current_data = b[0]->current_data; 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); pd->free_buffer_index = 0; pd->icv_removed = 0; pd->lb = b[0]; if (n_bufs > 1) { /* find last buffer in the chain */ while (pd->lb->flags & VLIB_BUFFER_NEXT_PRESENT) pd->lb = vlib_get_buffer (vm, pd->lb->next_buffer); crypto_ops = &ptd->chained_crypto_ops; integ_ops = &ptd->chained_integ_ops; } pd->current_length = b[0]->current_length; /* anti-reply check */ if (ipsec_sa_anti_replay_check (sa0, pd->seq)) { b[0]->error = node->errors[ESP_DECRYPT_ERROR_REPLAY]; next[0] = ESP_DECRYPT_NEXT_DROP; goto next; } if (pd->current_length < cpd.icv_sz + esp_sz + cpd.iv_sz) { b[0]->error = node->errors[ESP_DECRYPT_ERROR_RUNT]; next[0] = ESP_DECRYPT_NEXT_DROP; goto next; } len = pd->current_length - cpd.icv_sz; current_sa_pkts += 1; current_sa_bytes += vlib_buffer_length_in_chain (vm, b[0]); if (PREDICT_TRUE (sa0->integ_op_id != VNET_CRYPTO_OP_NONE)) { vnet_crypto_op_init (op, sa0->integ_op_id); op->key_index = sa0->integ_key_index; op->src = payload; op->flags = VNET_CRYPTO_OP_FLAG_HMAC_CHECK; op->user_data = b - bufs; op->digest = payload + len; op->digest_len = cpd.icv_sz; op->len = len; if (pd->lb != b[0]) { /* buffer is chained */ vlib_buffer_t *cb = b[0]; 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) { 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; cb = vlib_get_buffer (vm, cb->next_buffer); op->n_chunks = 1; while (1) { vec_add2 (ptd->chunks, ch, 1); op->n_chunks += 1; ch->src = vlib_buffer_get_current (cb); if (pd->lb == cb) { if (pd->icv_removed) ch->len = cb->current_length; else ch->len = cb->current_length - cpd.icv_sz; if (ipsec_sa_is_set_USE_ESN (sa0)) { u32 seq_hi = clib_host_to_net_u32 (sa0->seq_hi); u8 tmp[ESP_MAX_ICV_SIZE], sz = sizeof (sa0->seq_hi); u8 *esn; vlib_buffer_t *tmp_b; u16 space_left = vlib_buffer_space_left_at_end (vm, pd->lb); if (space_left < sz) { if (pd->icv_removed) { /* use pre-data area from the last bufer that was removed from the chain */ tmp_b = vlib_get_buffer (vm, pd->free_buffer_index); esn = tmp_b->data - sz; } else { /* no space, need to allocate new buffer */ u32 tmp_bi = 0; vlib_buffer_alloc (vm, &tmp_bi, 1); tmp_b = vlib_get_buffer (vm, tmp_bi); esn = tmp_b->data; pd->free_buffer_index = tmp_bi; } clib_memcpy_fast (esn, &seq_hi, sz); vec_add2 (ptd->chunks, ch, 1); op->n_chunks += 1; ch->src = esn; ch->len = sz; } else { if (pd->icv_removed) { clib_memcpy_fast (vlib_buffer_get_tail (pd->lb), &seq_hi, sz); } else { clib_memcpy_fast (tmp, op->digest, ESP_MAX_ICV_SIZE); clib_memcpy_fast (op->digest, &seq_hi, sz); clib_memcpy_fast (op->digest + sz, tmp, ESP_MAX_ICV_SIZE); op->digest += sz; } ch->len += sz; } } break; } else ch->len = cb->current_length; if (!(cb->flags & VLIB_BUFFER_NEXT_PRESENT)) break; cb = vlib_get_buffer (vm, cb->next_buffer); } } 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; len -= esp_sz; if (sa0->crypto_dec_op_id != VNET_CRYPTO_OP_NONE) { vnet_crypto_op_init (op, sa0->crypto_dec_op_id); op->key_index = sa0->crypto_key_index; op->iv = payload; if (ipsec_sa_is_set_IS_AEAD (sa0)) { esp_header_t *esp0; esp_aead_t *aad; u8 *scratch; /* * construct the AAD and the nonce (Salt || IV) in a scratch * space in front of the IP header. */ scratch = payload - esp_sz; esp0 = (esp_header_t *) (scratch); scratch -= (sizeof (*aad) + pd->hdr_sz); op->aad = scratch; esp_aad_fill (op, esp0, sa0); /* * we don't need to refer to the ESP header anymore so we * can overwrite it with the salt and use the IV where it is * to form the nonce = (Salt + IV) */ op->iv -= sizeof (sa0->salt); clib_memcpy_fast (op->iv, &sa0->salt, sizeof (sa0->salt)); op->tag = payload + len; op->tag_len = 16; } op->src = op->dst = payload += cpd.iv_sz; op->len = len - cpd.iv_sz; op->user_data = b - bufs; if (pd->lb != b[0]) { /* buffer is chained */ vlib_buffer_t *cb = b[0]; op->flags |= VNET_CRYPTO_OP_FLAG_CHAINED_BUFFERS; op->chunk_index = vec_len (ptd->chunks); vec_add2 (ptd->chunks, ch, 1); ch->len = len - cpd.iv_sz + cpd.icv_sz; ch->src = ch->dst = payload; cb = vlib_get_buffer (vm, cb->next_buffer); op->n_chunks = 1; while (1) { vec_add2 (ptd->chunks, ch, 1); op->n_chunks += 1; ch->src = ch->dst = vlib_buffer_get_current (cb); if (pd->lb == cb) { if (ipsec_sa_is_set_IS_AEAD (sa0)) { if (pd->lb->current_length < cpd.icv_sz) { u16 dif = 0; op->tag = esp_move_icv (vm, b[0], pd, cpd.icv_sz, &dif); /* this chunk does not contain crypto data */ op->n_chunks -= 1; /* and fix previous chunk's length as it might have been changed */ ASSERT (op->n_chunks > 0); if (pd->lb == b[0]) ch[-1].len -= dif; else ch[-1].len = pd->lb->current_length; break; } else op->tag = vlib_buffer_get_tail (pd->lb) - cpd.icv_sz; } if (pd->icv_removed) ch->len = cb->current_length; else ch->len = cb->current_length - cpd.icv_sz; } else ch->len = cb->current_length; if (!(cb->flags & VLIB_BUFFER_NEXT_PRESENT)) break; cb = vlib_get_buffer (vm, cb->next_buffer); } } vec_add_aligned (crypto_ops[0], op, 1, CLIB_CACHE_LINE_BYTES); } /* next */ next: n_left -= 1; next += 1; pd += 1; b += 1; } if (PREDICT_TRUE (~0 != current_sa_index)) vlib_increment_combined_counter (&ipsec_sa_counters, thread_index, current_sa_index, current_sa_pkts, current_sa_bytes); esp_process_ops (vm, node, ptd->integ_ops, bufs, nexts, ESP_DECRYPT_ERROR_INTEG_ERROR); esp_process_chained_ops (vm, node, ptd->chained_integ_ops, bufs, nexts, ptd->chunks, ESP_DECRYPT_ERROR_INTEG_ERROR); esp_process_ops (vm, node, ptd->crypto_ops, bufs, nexts, ESP_DECRYPT_ERROR_DECRYPTION_FAILED); esp_process_chained_ops (vm, node, ptd->chained_crypto_ops, bufs, nexts, ptd->chunks, ESP_DECRYPT_ERROR_DECRYPTION_FAILED); /* Post decryption ronud - adjust packet data start and length and next node */ n_left = from_frame->n_vectors; next = nexts; pd = pkt_data; b = bufs; while (n_left) { const u8 tun_flags = IPSEC_SA_FLAG_IS_TUNNEL | IPSEC_SA_FLAG_IS_TUNNEL_V6; if (n_left >= 2) { void *data = b[1]->data + pd[1].current_data; /* buffer metadata */ vlib_prefetch_buffer_header (b[1], LOAD); /* esp_footer_t */ CLIB_PREFETCH (data + pd[1].current_length - pd[1].icv_sz - 2, CLIB_CACHE_LINE_BYTES, LOAD); /* packet headers */ CLIB_PREFETCH (data - CLIB_CACHE_LINE_BYTES, CLIB_CACHE_LINE_BYTES * 2, LOAD); } if (next[0] < ESP_DECRYPT_N_NEXT) goto trace; sa0 = vec_elt_at_index (im->sad, pd->sa_index); /* * redo the anti-reply check * in this frame say we have sequence numbers, s, s+1, s+1, s+1 * and s and s+1 are in the window. When we did the anti-replay * check above we did so against the state of the window (W), * after packet s-1. So each of the packets in the sequence will be * accepted. * This time s will be cheked against Ws-1, s+1 chceked against Ws * (i.e. the window state is updated/advnaced) * so this time the successive s+! packet will be dropped. * This is a consequence of batching the decrypts. If the * check-dcrypt-advance process was done for each packet it would * be fine. But we batch the decrypts because it's much more efficient * to do so in SW and if we offload to HW and the process is async. * * You're probably thinking, but this means an attacker can send the * above sequence and cause VPP to perform decrpyts that will fail, * and that's true. But if the attacker can determine s (a valid * sequence number in the window) which is non-trivial, it can generate * a sequence s, s+1, s+2, s+3, ... s+n and nothing will prevent any * implementation, sequential or batching, from decrypting these. */ if (ipsec_sa_anti_replay_check (sa0, pd->seq)) { b[0]->error = node->errors[ESP_DECRYPT_ERROR_REPLAY]; next[0] = ESP_DECRYPT_NEXT_DROP; goto trace; } ipsec_sa_anti_replay_advance (sa0, pd->seq); u8 pad_length = 0, next_header = 0; u16 icv_sz = pd->icv_removed ? 0 : pd->icv_sz; if (pd->free_buffer_index) vlib_buffer_free_one (vm, pd->free_buffer_index); if (pd->lb->current_length < sizeof (esp_footer_t) + icv_sz) { /* esp footer is either splitted in two buffers or in the before * last buffer */ vlib_buffer_t *before_last = b[0], *bp = b[0]; while (bp->flags & VLIB_BUFFER_NEXT_PRESENT) { before_last = bp; bp = vlib_get_buffer (vm, bp->next_buffer); } u8 *bt = vlib_buffer_get_tail (before_last); if (pd->lb->current_length == icv_sz) { esp_footer_t *f = (esp_footer_t *) (bt - sizeof (*f)); pad_length = f->pad_length; next_header = f->next_header; } else { pad_length = (bt - 1)[0]; next_header = ((u8 *) vlib_buffer_get_current (pd->lb))[0]; } } else { esp_footer_t *f = (esp_footer_t *) (pd->lb->data + pd->lb->current_data + pd->lb->current_length - sizeof (esp_footer_t) - icv_sz); pad_length = f->pad_length; next_header = f->next_header; } u16 adv = pd->iv_sz + esp_sz; u16 tail = sizeof (esp_footer_t) + pad_length + icv_sz; u16 tail_orig = sizeof (esp_footer_t) + pad_length + pd->icv_sz; b[0]->flags &= ~VLIB_BUFFER_TOTAL_LENGTH_VALID; if ((pd->flags & tun_flags) == 0 && !is_tun) /* transport mode */ { u8 udp_sz = (is_ip6 == 0 && pd->flags & IPSEC_SA_FLAG_UDP_ENCAP) ? sizeof (udp_header_t) : 0; u16 ip_hdr_sz = pd->hdr_sz - udp_sz; u8 *old_ip = b[0]->data + pd->current_data - ip_hdr_sz - udp_sz; u8 *ip = old_ip + adv + udp_sz; if (is_ip6 && ip_hdr_sz > 64) memmove (ip, old_ip, ip_hdr_sz); else clib_memcpy_le64 (ip, old_ip, ip_hdr_sz); b[0]->current_data = pd->current_data + adv - ip_hdr_sz; b[0]->current_length += ip_hdr_sz - adv; esp_remove_tail (vm, b[0], pd->lb, tail); if (is_ip6) { ip6_header_t *ip6 = (ip6_header_t *) ip; u16 len = clib_net_to_host_u16 (ip6->payload_length); len -= adv + tail_orig; ip6->payload_length = clib_host_to_net_u16 (len); ip6->protocol = next_header; next[0] = ESP_DECRYPT_NEXT_IP6_INPUT; } else { ip4_header_t *ip4 = (ip4_header_t *) ip; ip_csum_t sum = ip4->checksum; u16 len = clib_net_to_host_u16 (ip4->length); len = clib_host_to_net_u16 (len - adv - tail_orig - udp_sz); sum = ip_csum_update (sum, ip4->protocol, next_header, ip4_header_t, protocol); sum = ip_csum_update (sum, ip4->length, len, ip4_header_t, length); ip4->checksum = ip_csum_fold (sum); ip4->protocol = next_header; ip4->length = len; next[0] = ESP_DECRYPT_NEXT_IP4_INPUT; } } else { if (PREDICT_TRUE (next_header == IP_PROTOCOL_IP_IN_IP)) { next[0] = ESP_DECRYPT_NEXT_IP4_INPUT; b[0]->current_data = pd->current_data + adv; b[0]->current_length = pd->current_length - adv; esp_remove_tail (vm, b[0], pd->lb, tail); } else if (next_header == IP_PROTOCOL_IPV6) { next[0] = ESP_DECRYPT_NEXT_IP6_INPUT; b[0]->current_data = pd->current_data + adv; b[0]->current_length = pd->current_length - adv; esp_remove_tail (vm, b[0], pd->lb, tail); } else { if (is_tun && next_header == IP_PROTOCOL_GRE) { gre_header_t *gre; b[0]->current_data = pd->current_data + adv; b[0]->current_length = pd->current_length - adv - tail; gre = vlib_buffer_get_current (b[0]); vlib_buffer_advance (b[0], sizeof (*gre)); switch (clib_net_to_host_u16 (gre->protocol)) { case GRE_PROTOCOL_teb: vnet_update_l2_len (b[0]); next[0] = ESP_DECRYPT_NEXT_L2_INPUT; break; case GRE_PROTOCOL_ip4: next[0] = ESP_DECRYPT_NEXT_IP4_INPUT; break; case GRE_PROTOCOL_ip6: next[0] = ESP_DECRYPT_NEXT_IP6_INPUT; break; default: b[0]->error = node->errors[ESP_DECRYPT_ERROR_UNSUP_PAYLOAD]; next[0] = ESP_DECRYPT_NEXT_DROP; break; } } else { next[0] = ESP_DECRYPT_NEXT_DROP; b[0]->error = node->errors[ESP_DECRYPT_ERROR_UNSUP_PAYLOAD]; goto trace; } } if (is_tun) { if (ipsec_sa_is_set_IS_PROTECT (sa0)) { /* * There are two encap possibilities * 1) the tunnel and ths SA are prodiving encap, i.e. it's * MAC | SA-IP | TUN-IP | ESP | PAYLOAD * implying the SA is in tunnel mode (on a tunnel interface) * 2) only the tunnel provides encap * MAC | TUN-IP | ESP | PAYLOAD * implying the SA is in transport mode. * * For 2) we need only strip the tunnel encap and we're good. * since the tunnel and crypto ecnap (int the tun=protect * object) are the same and we verified above that these match * for 1) we need to strip the SA-IP outer headers, to * reveal the tunnel IP and then check that this matches * the configured tunnel. */ const ipsec_tun_protect_t *itp; itp = ipsec_tun_protect_get (vnet_buffer (b[0])->ipsec.protect_index); if (PREDICT_TRUE (next_header == IP_PROTOCOL_IP_IN_IP)) { const ip4_header_t *ip4; ip4 = vlib_buffer_get_current (b[0]); if (!ip46_address_is_equal_v4 (&itp->itp_tun.src, &ip4->dst_address) || !ip46_address_is_equal_v4 (&itp->itp_tun.dst, &ip4->src_address)) { next[0] = ESP_DECRYPT_NEXT_DROP; b[0]->error = node->errors[ESP_DECRYPT_ERROR_TUN_NO_PROTO]; } } else if (next_header == IP_PROTOCOL_IPV6) { const ip6_header_t *ip6; ip6 = vlib_buffer_get_current (b[0]); if (!ip46_address_is_equal_v6 (&itp->itp_tun.src, &ip6->dst_address) || !ip46_address_is_equal_v6 (&itp->itp_tun.dst, &ip6->src_address)) { next[0] = ESP_DECRYPT_NEXT_DROP; b[0]->error = node->errors[ESP_DECRYPT_ERROR_TUN_NO_PROTO]; } } } } } trace: if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED)) { esp_decrypt_trace_t *tr; tr = vlib_add_trace (vm, node, b[0], sizeof (*tr)); sa0 = pool_elt_at_index (im->sad, vnet_buffer (b[0])->ipsec.sad_index); tr->crypto_alg = sa0->crypto_alg; tr->integ_alg = sa0->integ_alg; tr->seq = pd->seq; tr->sa_seq = sa0->last_seq; tr->sa_seq_hi = sa0->seq_hi; } /* next */ n_left -= 1; next += 1; pd += 1; b += 1; } n_left = from_frame->n_vectors; vlib_node_increment_counter (vm, node->node_index, ESP_DECRYPT_ERROR_RX_PKTS, n_left); vlib_buffer_enqueue_to_next (vm, node, from, nexts, n_left); return n_left; } VLIB_NODE_FN (esp4_decrypt_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return esp_decrypt_inline (vm, node, from_frame, 0, 0); } VLIB_NODE_FN (esp4_decrypt_tun_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return esp_decrypt_inline (vm, node, from_frame, 0, 1); } VLIB_NODE_FN (esp6_decrypt_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return esp_decrypt_inline (vm, node, from_frame, 1, 0); } VLIB_NODE_FN (esp6_decrypt_tun_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * from_frame) { return esp_decrypt_inline (vm, node, from_frame, 1, 1); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (esp4_decrypt_node) = { .name = "esp4-decrypt", .vector_size = sizeof (u32), .format_trace = format_esp_decrypt_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_errors = ARRAY_LEN(esp_decrypt_error_strings), .error_strings = esp_decrypt_error_strings, .n_next_nodes = ESP_DECRYPT_N_NEXT, .next_nodes = { [ESP_DECRYPT_NEXT_DROP] = "ip4-drop", [ESP_DECRYPT_NEXT_IP4_INPUT] = "ip4-input-no-checksum", [ESP_DECRYPT_NEXT_IP6_INPUT] = "ip6-input", [ESP_DECRYPT_NEXT_L2_INPUT] = "l2-input", [ESP_DECRYPT_NEXT_HANDOFF] = "esp4-decrypt-handoff", }, }; VLIB_REGISTER_NODE (esp6_decrypt_node) = { .name = "esp6-decrypt", .vector_size = sizeof (u32), .format_trace = format_esp_decrypt_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_errors = ARRAY_LEN(esp_decrypt_error_strings), .error_strings = esp_decrypt_error_strings, .n_next_nodes = ESP_DECRYPT_N_NEXT, .next_nodes = { [ESP_DECRYPT_NEXT_DROP] = "ip6-drop", [ESP_DECRYPT_NEXT_IP4_INPUT] = "ip4-input-no-checksum", [ESP_DECRYPT_NEXT_IP6_INPUT] = "ip6-input", [ESP_DECRYPT_NEXT_L2_INPUT] = "l2-input", [ESP_DECRYPT_NEXT_HANDOFF]= "esp6-decrypt-handoff", }, }; VLIB_REGISTER_NODE (esp4_decrypt_tun_node) = { .name = "esp4-decrypt-tun", .vector_size = sizeof (u32), .format_trace = format_esp_decrypt_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_errors = ARRAY_LEN(esp_decrypt_error_strings), .error_strings = esp_decrypt_error_strings, .n_next_nodes = ESP_DECRYPT_N_NEXT, .next_nodes = { [ESP_DECRYPT_NEXT_DROP] = "ip4-drop", [ESP_DECRYPT_NEXT_IP4_INPUT] = "ip4-input-no-checksum", [ESP_DECRYPT_NEXT_IP6_INPUT] = "ip6-input", [ESP_DECRYPT_NEXT_L2_INPUT] = "l2-input", [ESP_DECRYPT_NEXT_HANDOFF] = "esp4-decrypt-tun-handoff", }, }; VLIB_REGISTER_NODE (esp6_decrypt_tun_node) = { .name = "esp6-decrypt-tun", .vector_size = sizeof (u32), .format_trace = format_esp_decrypt_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_errors = ARRAY_LEN(esp_decrypt_error_strings), .error_strings = esp_decrypt_error_strings, .n_next_nodes = ESP_DECRYPT_N_NEXT, .next_nodes = { [ESP_DECRYPT_NEXT_DROP] = "ip6-drop", [ESP_DECRYPT_NEXT_IP4_INPUT] = "ip4-input-no-checksum", [ESP_DECRYPT_NEXT_IP6_INPUT] = "ip6-input", [ESP_DECRYPT_NEXT_L2_INPUT] = "l2-input", [ESP_DECRYPT_NEXT_HANDOFF]= "esp6-decrypt-tun-handoff", }, }; /* *INDENT-ON* */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */