From fe0aa7648703f63159be8362836b39d4727fbb0c Mon Sep 17 00:00:00 2001 From: Juraj Sloboda Date: Mon, 23 Jul 2018 12:22:54 +0200 Subject: NAT44 virtual fragmentation reassembly for endpoint-dependent mode (VPP-1325) Change-Id: I36ece2ef2eaef9fa559d69ec7f7f07e7c16a7a9d Signed-off-by: Juraj Sloboda --- src/plugins/nat/out2in.c | 405 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 389 insertions(+), 16 deletions(-) (limited to 'src/plugins/nat/out2in.c') diff --git a/src/plugins/nat/out2in.c b/src/plugins/nat/out2in.c index 3d4e9228e67..ba343ad72a5 100755 --- a/src/plugins/nat/out2in.c +++ b/src/plugins/nat/out2in.c @@ -106,6 +106,7 @@ vlib_node_registration_t snat_det_out2in_node; vlib_node_registration_t nat44_out2in_reass_node; vlib_node_registration_t nat44_ed_out2in_node; vlib_node_registration_t nat44_ed_out2in_slowpath_node; +vlib_node_registration_t nat44_ed_out2in_reass_node; #define foreach_snat_out2in_error \ _(UNSUPPORTED_PROTOCOL, "Unsupported protocol") \ @@ -539,13 +540,16 @@ static inline u32 icmp_out2in (snat_main_t *sm, if (next0 == SNAT_OUT2IN_NEXT_DROP || dont_translate) goto out; - sum0 = ip_incremental_checksum (0, icmp0, - ntohs(ip0->length) - ip4_header_bytes (ip0)); - checksum0 = ~ip_csum_fold (sum0); - if (checksum0 != 0 && checksum0 != 0xffff) + if (PREDICT_TRUE (!ip4_is_fragment (ip0))) { - next0 = SNAT_OUT2IN_NEXT_DROP; - goto out; + sum0 = ip_incremental_checksum (0, icmp0, + ntohs(ip0->length) - ip4_header_bytes (ip0)); + checksum0 = ~ip_csum_fold (sum0); + if (checksum0 != 0 && checksum0 != 0xffff) + { + next0 = SNAT_OUT2IN_NEXT_DROP; + goto out; + } } old_addr0 = ip0->dst_address.as_u32; @@ -1582,6 +1586,7 @@ typedef enum { NAT44_ED_OUT2IN_NEXT_ICMP_ERROR, NAT44_ED_OUT2IN_NEXT_IN2OUT, NAT44_ED_OUT2IN_NEXT_SLOW_PATH, + NAT44_ED_OUT2IN_NEXT_REASS, NAT44_ED_OUT2IN_N_NEXT, } nat44_ed_out2in_next_t; @@ -2298,7 +2303,7 @@ nat44_ed_out2in_node_fn_inline (vlib_main_t * vm, } else { - if (PREDICT_FALSE (proto0 == ~0 || proto0 == SNAT_PROTOCOL_ICMP)) + if (PREDICT_FALSE (proto0 == ~0)) { next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH; goto trace00; @@ -2306,8 +2311,13 @@ nat44_ed_out2in_node_fn_inline (vlib_main_t * vm, if (ip4_is_fragment (ip0)) { - b0->error = node->errors[SNAT_OUT2IN_ERROR_DROP_FRAGMENT]; - next0 = NAT44_ED_OUT2IN_NEXT_DROP; + next0 = NAT44_ED_OUT2IN_NEXT_REASS; + goto trace00; + } + + if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP)) + { + next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH; goto trace00; } } @@ -2501,7 +2511,7 @@ nat44_ed_out2in_node_fn_inline (vlib_main_t * vm, } else { - if (PREDICT_FALSE (proto1 == ~0 || proto1 == SNAT_PROTOCOL_ICMP)) + if (PREDICT_FALSE (proto1 == ~0)) { next1 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH; goto trace01; @@ -2509,8 +2519,13 @@ nat44_ed_out2in_node_fn_inline (vlib_main_t * vm, if (ip4_is_fragment (ip1)) { - b1->error = node->errors[SNAT_OUT2IN_ERROR_DROP_FRAGMENT]; - next1 = NAT44_ED_OUT2IN_NEXT_DROP; + next1 = NAT44_ED_OUT2IN_NEXT_REASS; + goto trace01; + } + + if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP)) + { + next1 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH; goto trace01; } } @@ -2736,7 +2751,7 @@ nat44_ed_out2in_node_fn_inline (vlib_main_t * vm, } else { - if (PREDICT_FALSE (proto0 == ~0 || proto0 == SNAT_PROTOCOL_ICMP)) + if (PREDICT_FALSE (proto0 == ~0)) { next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH; goto trace0; @@ -2744,8 +2759,13 @@ nat44_ed_out2in_node_fn_inline (vlib_main_t * vm, if (ip4_is_fragment (ip0)) { - b0->error = node->errors[SNAT_OUT2IN_ERROR_DROP_FRAGMENT]; - next0 = NAT44_ED_OUT2IN_NEXT_DROP; + next0 = NAT44_ED_OUT2IN_NEXT_REASS; + goto trace0; + } + + if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP)) + { + next0 = NAT44_ED_OUT2IN_NEXT_SLOW_PATH; goto trace0; } } @@ -2891,7 +2911,6 @@ nat44_ed_out2in_node_fn_inline (vlib_main_t * vm, } pkts_processed += next0 != NAT44_ED_OUT2IN_NEXT_DROP; - /* verify speculative enqueue, maybe switch current next frame */ vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, n_left_to_next, @@ -2936,6 +2955,7 @@ VLIB_REGISTER_NODE (nat44_ed_out2in_node) = { [NAT44_ED_OUT2IN_NEXT_SLOW_PATH] = "nat44-ed-out2in-slowpath", [NAT44_ED_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error", [NAT44_ED_OUT2IN_NEXT_IN2OUT] = "nat44-ed-in2out", + [NAT44_ED_OUT2IN_NEXT_REASS] = "nat44-ed-out2in-reass", }, }; @@ -2970,12 +2990,365 @@ VLIB_REGISTER_NODE (nat44_ed_out2in_slowpath_node) = { [NAT44_ED_OUT2IN_NEXT_SLOW_PATH] = "nat44-ed-out2in-slowpath", [NAT44_ED_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error", [NAT44_ED_OUT2IN_NEXT_IN2OUT] = "nat44-ed-in2out", + [NAT44_ED_OUT2IN_NEXT_REASS] = "nat44-ed-out2in-reass", }, }; VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_out2in_slowpath_node, nat44_ed_out2in_slow_path_fn); +static uword +nat44_ed_out2in_reass_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, + vlib_frame_t * frame) +{ + u32 n_left_from, *from, *to_next; + snat_out2in_next_t next_index; + u32 pkts_processed = 0; + snat_main_t *sm = &snat_main; + f64 now = vlib_time_now (vm); + u32 thread_index = vm->thread_index; + snat_main_per_thread_data_t *per_thread_data = + &sm->per_thread_data[thread_index]; + u32 *fragments_to_drop = 0; + u32 *fragments_to_loopback = 0; + + from = vlib_frame_vector_args (frame); + n_left_from = frame->n_vectors; + 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 bi0, sw_if_index0, proto0, rx_fib_index0, new_addr0, old_addr0; + vlib_buffer_t *b0; + u32 next0; + u8 cached0 = 0; + ip4_header_t *ip0; + nat_reass_ip4_t *reass0; + udp_header_t * udp0; + tcp_header_t * tcp0; + icmp46_header_t * icmp0; + clib_bihash_kv_16_8_t kv0, value0; + snat_session_t * s0 = 0; + u16 old_port0, new_port0; + ip_csum_t sum0; + snat_session_key_t e_key0, l_key0; + lb_nat_type_t lb0; + twice_nat_type_t twice_nat0; + + /* speculatively enqueue b0 to the current next frame */ + bi0 = from[0]; + to_next[0] = bi0; + from += 1; + to_next += 1; + n_left_from -= 1; + n_left_to_next -= 1; + + b0 = vlib_get_buffer (vm, bi0); + next0 = NAT44_ED_OUT2IN_NEXT_LOOKUP; + + sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX]; + rx_fib_index0 = fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, + sw_if_index0); + + if (PREDICT_FALSE (nat_reass_is_drop_frag(0))) + { + next0 = NAT44_ED_OUT2IN_NEXT_DROP; + b0->error = node->errors[SNAT_OUT2IN_ERROR_DROP_FRAGMENT]; + goto trace0; + } + + ip0 = (ip4_header_t *) vlib_buffer_get_current (b0); + udp0 = ip4_next_header (ip0); + tcp0 = (tcp_header_t *) udp0; + icmp0 = (icmp46_header_t *) udp0; + proto0 = ip_proto_to_snat_proto (ip0->protocol); + + reass0 = nat_ip4_reass_find_or_create (ip0->src_address, + ip0->dst_address, + ip0->fragment_id, + ip0->protocol, + 1, + &fragments_to_drop); + + if (PREDICT_FALSE (!reass0)) + { + next0 = NAT44_ED_OUT2IN_NEXT_DROP; + b0->error = node->errors[SNAT_OUT2IN_ERROR_MAX_REASS]; + nat_log_notice ("maximum reassemblies exceeded"); + goto trace0; + } + + if (PREDICT_FALSE (ip4_is_first_fragment (ip0))) + { + if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP)) + { + next0 = icmp_out2in_slow_path + (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node, + next0, now, thread_index, &s0); + + if (PREDICT_TRUE(next0 != NAT44_ED_OUT2IN_NEXT_DROP)) + { + if (s0) + reass0->sess_index = s0 - per_thread_data->sessions; + else + reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE; + reass0->thread_index = thread_index; + nat_ip4_reass_get_frags (reass0, &fragments_to_loopback); + } + + goto trace0; + } + + make_ed_kv (&kv0, &ip0->dst_address, &ip0->src_address, ip0->protocol, + rx_fib_index0, udp0->dst_port, udp0->src_port); + + if (clib_bihash_search_16_8 (&per_thread_data->out2in_ed, &kv0, &value0)) + { + /* Try to match static mapping by external address and port, + destination address and port in packet */ + e_key0.addr = ip0->dst_address; + e_key0.port = udp0->dst_port; + e_key0.protocol = proto0; + e_key0.fib_index = rx_fib_index0; + if (snat_static_mapping_match(sm, e_key0, &l_key0, 1, 0, + &twice_nat0, &lb0, 0)) + { + /* + * Send DHCP packets to the ipv4 stack, or we won't + * be able to use dhcp client on the outside interface + */ + if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_UDP + && (udp0->dst_port + == clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client)))) + { + vnet_feature_next(&next0, b0); + goto trace0; + } + + if (!sm->forwarding_enabled) + { + b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION]; + next0 = NAT44_ED_OUT2IN_NEXT_DROP; + } + else + { + if (next_src_nat(sm, ip0, ip0->protocol, + udp0->src_port, udp0->dst_port, + thread_index, rx_fib_index0)) + { + next0 = NAT44_ED_OUT2IN_NEXT_IN2OUT; + goto trace0; + } + create_bypass_for_fwd(sm, ip0, rx_fib_index0, + thread_index); + reass0->flags |= NAT_REASS_FLAG_ED_DONT_TRANSLATE; + nat_ip4_reass_get_frags (reass0, &fragments_to_loopback); + } + goto trace0; + } + + /* Create session initiated by host from external network */ + s0 = create_session_for_static_mapping_ed(sm, b0, l_key0, + e_key0, node, + thread_index, + twice_nat0, lb0, + now); + if (!s0) + { + b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION]; + next0 = NAT44_ED_OUT2IN_NEXT_DROP; + goto trace0; + } + reass0->sess_index = s0 - per_thread_data->sessions; + reass0->thread_index = thread_index; + } + else + { + s0 = pool_elt_at_index (per_thread_data->sessions, + value0.value); + reass0->sess_index = value0.value; + } + nat_ip4_reass_get_frags (reass0, &fragments_to_loopback); + } + else + { + if (reass0->flags & NAT_REASS_FLAG_ED_DONT_TRANSLATE) + goto trace0; + if (PREDICT_FALSE (reass0->sess_index == (u32) ~0)) + { + if (nat_ip4_reass_add_fragment (reass0, bi0, &fragments_to_drop)) + { + b0->error = node->errors[SNAT_OUT2IN_ERROR_MAX_FRAG]; + nat_log_notice ("maximum fragments per reassembly exceeded"); + next0 = NAT44_ED_OUT2IN_NEXT_DROP; + goto trace0; + } + cached0 = 1; + goto trace0; + } + s0 = pool_elt_at_index (per_thread_data->sessions, + reass0->sess_index); + } + + old_addr0 = ip0->dst_address.as_u32; + ip0->dst_address = s0->in2out.addr; + new_addr0 = ip0->dst_address.as_u32; + vnet_buffer(b0)->sw_if_index[VLIB_TX] = s0->in2out.fib_index; + + sum0 = ip0->checksum; + sum0 = ip_csum_update (sum0, old_addr0, new_addr0, + ip4_header_t, + dst_address /* changed member */); + if (PREDICT_FALSE (is_twice_nat_session (s0))) + sum0 = ip_csum_update (sum0, ip0->src_address.as_u32, + s0->ext_host_nat_addr.as_u32, ip4_header_t, + src_address); + ip0->checksum = ip_csum_fold (sum0); + + if (PREDICT_FALSE (ip4_is_first_fragment (ip0))) + { + if (PREDICT_TRUE(proto0 == SNAT_PROTOCOL_TCP)) + { + old_port0 = tcp0->dst_port; + tcp0->dst_port = s0->in2out.port; + new_port0 = tcp0->dst_port; + + sum0 = tcp0->checksum; + sum0 = ip_csum_update (sum0, old_addr0, new_addr0, + ip4_header_t, + dst_address /* changed member */); + + sum0 = ip_csum_update (sum0, old_port0, new_port0, + ip4_header_t /* cheat */, + length /* changed member */); + if (is_twice_nat_session (s0)) + { + sum0 = ip_csum_update (sum0, ip0->src_address.as_u32, + s0->ext_host_nat_addr.as_u32, + ip4_header_t, dst_address); + sum0 = ip_csum_update (sum0, tcp0->src_port, + s0->ext_host_nat_port, ip4_header_t, + length); + tcp0->src_port = s0->ext_host_nat_port; + ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32; + } + tcp0->checksum = ip_csum_fold(sum0); + } + else + { + old_port0 = udp0->dst_port; + udp0->dst_port = s0->in2out.port; + if (is_twice_nat_session (s0)) + { + udp0->src_port = s0->ext_host_nat_port; + ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32; + } + udp0->checksum = 0; + } + } + + /* Accounting */ + nat44_session_update_counters (s0, now, + vlib_buffer_length_in_chain (vm, b0)); + /* Per-user LRU list maintenance */ + nat44_session_update_lru (sm, s0, thread_index); + + trace0: + if (PREDICT_FALSE((node->flags & VLIB_NODE_FLAG_TRACE) + && (b0->flags & VLIB_BUFFER_IS_TRACED))) + { + nat44_out2in_reass_trace_t *t = + vlib_add_trace (vm, node, b0, sizeof (*t)); + t->cached = cached0; + t->sw_if_index = sw_if_index0; + t->next_index = next0; + } + + if (cached0) + { + n_left_to_next++; + to_next--; + } + else + { + pkts_processed += next0 != NAT44_ED_OUT2IN_NEXT_DROP; + + /* verify speculative enqueue, maybe switch current next frame */ + vlib_validate_buffer_enqueue_x1 (vm, node, next_index, + to_next, n_left_to_next, + bi0, next0); + } + + if (n_left_from == 0 && vec_len (fragments_to_loopback)) + { + from = vlib_frame_vector_args (frame); + u32 len = vec_len (fragments_to_loopback); + if (len <= VLIB_FRAME_SIZE) + { + clib_memcpy (from, fragments_to_loopback, sizeof (u32) * len); + n_left_from = len; + vec_reset_length (fragments_to_loopback); + } + else + { + clib_memcpy (from, + fragments_to_loopback + (len - VLIB_FRAME_SIZE), + sizeof (u32) * VLIB_FRAME_SIZE); + n_left_from = VLIB_FRAME_SIZE; + _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE; + } + } + } + + vlib_put_next_frame (vm, node, next_index, n_left_to_next); + } + + vlib_node_increment_counter (vm, nat44_out2in_reass_node.index, + SNAT_OUT2IN_ERROR_OUT2IN_PACKETS, + pkts_processed); + + nat_send_all_to_node (vm, fragments_to_drop, node, + &node->errors[SNAT_OUT2IN_ERROR_DROP_FRAGMENT], + SNAT_OUT2IN_NEXT_DROP); + + vec_free (fragments_to_drop); + vec_free (fragments_to_loopback); + return frame->n_vectors; +} + +VLIB_REGISTER_NODE (nat44_ed_out2in_reass_node) = { + .function = nat44_ed_out2in_reass_node_fn, + .name = "nat44-ed-out2in-reass", + .vector_size = sizeof (u32), + .format_trace = format_nat44_out2in_reass_trace, + .type = VLIB_NODE_TYPE_INTERNAL, + + .n_errors = ARRAY_LEN(snat_out2in_error_strings), + .error_strings = snat_out2in_error_strings, + + .n_next_nodes = NAT44_ED_OUT2IN_N_NEXT, + + /* edit / add dispositions here */ + .next_nodes = { + [NAT44_ED_OUT2IN_NEXT_DROP] = "error-drop", + [NAT44_ED_OUT2IN_NEXT_LOOKUP] = "ip4-lookup", + [NAT44_ED_OUT2IN_NEXT_SLOW_PATH] = "nat44-ed-out2in-slowpath", + [NAT44_ED_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error", + [NAT44_ED_OUT2IN_NEXT_IN2OUT] = "nat44-ed-in2out", + [NAT44_ED_OUT2IN_NEXT_REASS] = "nat44-ed-out2in-reass", + }, +}; + +VLIB_NODE_FUNCTION_MULTIARCH (nat44_ed_out2in_reass_node, + nat44_ed_out2in_reass_node_fn); + /**************************/ /*** deterministic mode ***/ /**************************/ -- cgit 1.2.3-korg