X-Git-Url: https://gerrit.fd.io/r/gitweb?a=blobdiff_plain;f=src%2Fvnet%2Fipsec%2Fesp_decrypt.c;h=8afea9b32a05693ade55891e4de0780d3f7a3fe5;hb=568acbb7c980608e238b25b1330d2730b8534599;hp=8272bb0dbcb9b1214d5278ba9af5d8d37182470e;hpb=2a2e5938a3a019f94b4acf53191bf4a42d72c68a;p=vpp.git diff --git a/src/vnet/ipsec/esp_decrypt.c b/src/vnet/ipsec/esp_decrypt.c index 8272bb0dbcb..8afea9b32a0 100644 --- a/src/vnet/ipsec/esp_decrypt.c +++ b/src/vnet/ipsec/esp_decrypt.c @@ -22,12 +22,16 @@ #include #include #include +#include + +#include #define foreach_esp_decrypt_next \ _(DROP, "error-drop") \ _(IP4_INPUT, "ip4-input-no-checksum") \ _(IP6_INPUT, "ip6-input") \ -_(IPSEC_GRE_INPUT, "ipsec-gre-input") +_(L2_INPUT, "l2-input") \ +_(HANDOFF, "handoff") #define _(v, s) ESP_DECRYPT_NEXT_##v, typedef enum @@ -47,7 +51,8 @@ typedef enum _(RUNT, "undersized packet") \ _(CHAINED_BUFFER, "chained buffers (packet dropped)") \ _(OVERSIZED_HEADER, "buffer with oversized header (dropped)") \ - _(NO_TAIL_SPACE, "no enough buffer tail space (dropped)") + _(NO_TAIL_SPACE, "no enough buffer tail space (dropped)") \ + _(TUN_NO_PROTO, "no tunnel protocol") \ typedef enum @@ -67,6 +72,8 @@ static char *esp_decrypt_error_strings[] = { 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; @@ -79,9 +86,11 @@ format_esp_decrypt_trace (u8 * s, va_list * args) 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 seq %u", - format_ipsec_crypto_alg, t->crypto_alg, - format_ipsec_integ_alg, t->integ_alg, t->seq); + 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; } @@ -93,25 +102,26 @@ typedef struct { u8 icv_sz; u8 iv_sz; - ipsec_sa_flags_t flags:8; + ipsec_sa_flags_t flags; u32 sa_index; }; u64 sa_data; }; + u32 seq; i16 current_data; i16 current_length; u16 hdr_sz; } esp_decrypt_packet_data_t; -STATIC_ASSERT_SIZEOF (esp_decrypt_packet_data_t, 2 * sizeof (u64)); +STATIC_ASSERT_SIZEOF (esp_decrypt_packet_data_t, 3 * sizeof (u64)); #define ESP_ENCRYPT_PD_F_FD_TRANSPORT (1 << 2) 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_ip6, int is_tun) { ipsec_main_t *im = &ipsec_main; u32 thread_index = vm->thread_index; @@ -156,18 +166,34 @@ esp_decrypt_inline (vlib_main_t * vm, 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; + } - vlib_increment_combined_counter (&ipsec_sa_counters, thread_index, - current_sa_index, current_sa_pkts, - current_sa_bytes); + 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)); + } - current_sa_bytes = current_sa_pkts = 0; + 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 */ @@ -176,6 +202,7 @@ esp_decrypt_inline (vlib_main_t * vm, 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); /* we need 4 extra bytes for HMAC calculation when ESN are used */ if (ipsec_sa_is_set_USE_ESN (sa0) && pd->icv_sz && @@ -187,7 +214,7 @@ esp_decrypt_inline (vlib_main_t * vm, } /* anti-reply check */ - if (ipsec_sa_anti_replay_check (sa0, &((esp_header_t *) payload)->seq)) + if (ipsec_sa_anti_replay_check (sa0, pd->seq)) { b[0]->error = node->errors[ESP_DECRYPT_ERROR_REPLAY]; next[0] = ESP_DECRYPT_NEXT_DROP; @@ -220,10 +247,11 @@ esp_decrypt_inline (vlib_main_t * vm, op->len = len; if (ipsec_sa_is_set_USE_ESN (sa0)) { - /* shift ICV for 4 bytes to insert ESN */ + /* 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, &sa0->seq_hi, sz); + 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; @@ -367,9 +395,37 @@ esp_decrypt_inline (vlib_main_t * vm, goto trace; sa0 = vec_elt_at_index (im->sad, pd->sa_index); - u8 *payload = b[0]->data + pd->current_data; - ipsec_sa_anti_replay_advance (sa0, ((esp_header_t *) payload)->seq); + /* + * 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); esp_footer_t *f = (esp_footer_t *) (b[0]->data + pd->current_data + pd->current_length - sizeof (*f) - @@ -377,7 +433,7 @@ esp_decrypt_inline (vlib_main_t * vm, u16 adv = pd->iv_sz + esp_sz; u16 tail = sizeof (esp_footer_t) + f->pad_length + pd->icv_sz; - if ((pd->flags & tun_flags) == 0) /* transport mode */ + 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; @@ -434,25 +490,102 @@ esp_decrypt_inline (vlib_main_t * vm, } else { - next[0] = ESP_DECRYPT_NEXT_DROP; - b[0]->error = node->errors[ESP_DECRYPT_ERROR_DECRYPTION_FAILED]; + if (is_tun && f->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: + 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: + next[0] = ESP_DECRYPT_NEXT_DROP; + break; + } + } + else + { + next[0] = ESP_DECRYPT_NEXT_DROP; + b[0]->error = + node->errors[ESP_DECRYPT_ERROR_DECRYPTION_FAILED]; + goto trace; + } + } + if (is_tun) + { + if (ipsec_sa_is_set_IS_PROTECT (sa0)) + { + /* + * Check that the reveal IP header matches that + * of the tunnel we are protecting + */ + const ipsec_tun_protect_t *itp; + + itp = ipsec_tun_protect_get + (vnet_buffer (b[0])->ipsec.protect_index); + + if (PREDICT_TRUE (f->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 (f->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]; + } + } + } } } - if (PREDICT_FALSE (ipsec_sa_is_set_IS_GRE (sa0))) - next[0] = ESP_DECRYPT_NEXT_IPSEC_GRE_INPUT; - trace: if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED)) { esp_decrypt_trace_t *tr; - u8 *payload = b[0]->data + pd->current_data; 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 = clib_host_to_net_u32 (((esp_header_t *) payload)->seq); + tr->seq = pd->seq; + tr->sa_seq = sa0->last_seq; + tr->sa_seq_hi = sa0->seq_hi; } /* next */ @@ -476,7 +609,28 @@ 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 /* is_ip6 */ ); + 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* */ @@ -491,21 +645,14 @@ VLIB_REGISTER_NODE (esp4_decrypt_node) = { .n_next_nodes = ESP_DECRYPT_N_NEXT, .next_nodes = { -#define _(s,n) [ESP_DECRYPT_NEXT_##s] = n, - foreach_esp_decrypt_next -#undef _ + [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", }, }; -/* *INDENT-ON* */ - -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 /* is_ip6 */ ); -} -/* *INDENT-OFF* */ VLIB_REGISTER_NODE (esp6_decrypt_node) = { .name = "esp6-decrypt", .vector_size = sizeof (u32), @@ -517,9 +664,45 @@ VLIB_REGISTER_NODE (esp6_decrypt_node) = { .n_next_nodes = ESP_DECRYPT_N_NEXT, .next_nodes = { -#define _(s,n) [ESP_DECRYPT_NEXT_##s] = n, - foreach_esp_decrypt_next -#undef _ + [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-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-handoff", }, }; /* *INDENT-ON* */