diff options
Diffstat (limited to 'src/plugins/nat/out2in.c')
| -rwxr-xr-x | src/plugins/nat/out2in.c | 336 |
1 files changed, 334 insertions, 2 deletions
diff --git a/src/plugins/nat/out2in.c b/src/plugins/nat/out2in.c index f250136b86e..489afadb4a2 100755 --- a/src/plugins/nat/out2in.c +++ b/src/plugins/nat/out2in.c @@ -25,6 +25,7 @@ #include <nat/nat.h> #include <nat/nat_ipfix_logging.h> #include <nat/nat_det.h> +#include <nat/nat_reass.h> #include <vppinfra/hash.h> #include <vppinfra/error.h> @@ -78,17 +79,40 @@ static u8 * format_snat_out2in_worker_handoff_trace (u8 * s, va_list * args) return s; } +typedef struct { + u32 sw_if_index; + u32 next_index; + u8 cached; +} nat44_out2in_reass_trace_t; + +static u8 * format_nat44_out2in_reass_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 *); + nat44_out2in_reass_trace_t * t = va_arg (*args, nat44_out2in_reass_trace_t *); + + s = format (s, "NAT44_OUT2IN_REASS: sw_if_index %d, next index %d, status %s", + t->sw_if_index, t->next_index, + t->cached ? "cached" : "translated"); + + return s; +} + vlib_node_registration_t snat_out2in_node; vlib_node_registration_t snat_out2in_fast_node; vlib_node_registration_t snat_out2in_worker_handoff_node; vlib_node_registration_t snat_det_out2in_node; +vlib_node_registration_t nat44_out2in_reass_node; #define foreach_snat_out2in_error \ _(UNSUPPORTED_PROTOCOL, "Unsupported protocol") \ _(OUT2IN_PACKETS, "Good out2in packets processed") \ _(BAD_ICMP_TYPE, "unsupported ICMP type") \ _(NO_TRANSLATION, "No translation") \ -_(MAX_SESSIONS_EXCEEDED, "Maximum sessions exceeded") +_(MAX_SESSIONS_EXCEEDED, "Maximum sessions exceeded") \ +_(DROP_FRAGMENT, "Drop fragment") \ +_(MAX_REASS, "Maximum reassemblies exceeded") \ +_(MAX_FRAG, "Maximum fragments per reassembly exceeded") typedef enum { #define _(sym,str) SNAT_OUT2IN_ERROR_##sym, @@ -107,6 +131,7 @@ typedef enum { SNAT_OUT2IN_NEXT_DROP, SNAT_OUT2IN_NEXT_LOOKUP, SNAT_OUT2IN_NEXT_ICMP_ERROR, + SNAT_OUT2IN_NEXT_REASS, SNAT_OUT2IN_N_NEXT, } snat_out2in_next_t; @@ -139,6 +164,7 @@ create_session_for_static_mapping (snat_main_t *sm, dlist_elt_t * per_user_translation_list_elt; dlist_elt_t * per_user_list_head_elt; ip4_header_t *ip0; + udp_header_t *udp0; if (PREDICT_FALSE (maximum_sessions_exceeded(sm, thread_index))) { @@ -147,6 +173,7 @@ create_session_for_static_mapping (snat_main_t *sm, } ip0 = vlib_buffer_get_current (b0); + udp0 = ip4_next_header (ip0); user_key.addr = in2out.addr; user_key.fib_index = in2out.fib_index; @@ -188,7 +215,8 @@ create_session_for_static_mapping (snat_main_t *sm, s->outside_address_index = ~0; s->flags |= SNAT_SESSION_FLAG_STATIC_MAPPING; - s->ext_host_addr.as_u32 = ip0->dst_address.as_u32; + s->ext_host_addr.as_u32 = ip0->src_address.as_u32; + s->ext_host_port = udp0->src_port; u->nstaticsessions++; /* Create list elts */ @@ -1033,6 +1061,12 @@ snat_out2in_node_fn (vlib_main_t * vm, goto trace0; } + if (PREDICT_FALSE (ip4_is_fragment (ip0))) + { + next0 = SNAT_OUT2IN_NEXT_REASS; + goto trace0; + } + key0.addr = ip0->dst_address; key0.port = udp0->dst_port; key0.protocol = proto0; @@ -1188,6 +1222,12 @@ snat_out2in_node_fn (vlib_main_t * vm, goto trace1; } + if (PREDICT_FALSE (ip4_is_fragment (ip1))) + { + next1 = SNAT_OUT2IN_NEXT_REASS; + goto trace1; + } + key1.addr = ip1->dst_address; key1.port = udp1->dst_port; key1.protocol = proto1; @@ -1379,6 +1419,12 @@ snat_out2in_node_fn (vlib_main_t * vm, goto trace00; } + if (PREDICT_FALSE (ip4_is_fragment (ip0))) + { + next0 = SNAT_OUT2IN_NEXT_REASS; + goto trace00; + } + key0.addr = ip0->dst_address; key0.port = udp0->dst_port; key0.protocol = proto0; @@ -1530,10 +1576,294 @@ VLIB_REGISTER_NODE (snat_out2in_node) = { [SNAT_OUT2IN_NEXT_DROP] = "error-drop", [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup", [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error", + [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass", }, }; VLIB_NODE_FUNCTION_MULTIARCH (snat_out2in_node, snat_out2in_node_fn); +static uword +nat44_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 = vlib_get_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; + snat_session_key_t key0, sm0; + clib_bihash_kv_8_8_t kv0, value0; + snat_session_t * s0 = 0; + u16 old_port0, new_port0; + ip_csum_t sum0; + + /* 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 = SNAT_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 = SNAT_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; + 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 = SNAT_OUT2IN_NEXT_DROP; + b0->error = node->errors[SNAT_OUT2IN_ERROR_MAX_REASS]; + goto trace0; + } + + if (PREDICT_FALSE (ip4_is_first_fragment (ip0))) + { + key0.addr = ip0->dst_address; + key0.port = udp0->dst_port; + key0.protocol = proto0; + key0.fib_index = rx_fib_index0; + kv0.key = key0.as_u64; + + if (clib_bihash_search_8_8 (&per_thread_data->out2in, &kv0, &value0)) + { + /* Try to match static mapping by external address and port, + destination address and port in packet */ + if (snat_static_mapping_match(sm, key0, &sm0, 1, 0)) + { + b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION]; + /* + * Send DHCP packets to the ipv4 stack, or we won't + * be able to use dhcp client on the outside interface + */ + if (proto0 != SNAT_PROTOCOL_UDP + || (udp0->dst_port + != clib_host_to_net_u16(UDP_DST_PORT_dhcp_to_client))) + + next0 = SNAT_OUT2IN_NEXT_DROP; + goto trace0; + } + + /* Create session initiated by host from external network */ + s0 = create_session_for_static_mapping(sm, b0, sm0, key0, node, + thread_index); + if (!s0) + { + b0->error = node->errors[SNAT_OUT2IN_ERROR_NO_TRANSLATION]; + next0 = SNAT_OUT2IN_NEXT_DROP; + goto trace0; + } + reass0->sess_index = s0 - per_thread_data->sessions; + } + 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 (PREDICT_FALSE (reass0->sess_index == (u32) ~0)) + { + if (nat_ip4_reass_add_fragment (reass0, bi0)) + { + b0->error = node->errors[SNAT_OUT2IN_ERROR_MAX_FRAG]; + next0 = SNAT_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 */); + 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 */); + tcp0->checksum = ip_csum_fold(sum0); + } + else + { + old_port0 = udp0->dst_port; + udp0->dst_port = s0->in2out.port; + udp0->checksum = 0; + } + } + + /* Accounting */ + s0->last_heard = now; + s0->total_pkts++; + s0->total_bytes += vlib_buffer_length_in_chain (vm, b0); + /* Per-user LRU list maintenance for dynamic translation */ + if (!snat_is_session_static (s0)) + { + clib_dlist_remove (sm->per_thread_data[thread_index].list_pool, + s0->per_user_index); + clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool, + s0->per_user_list_head_index, + s0->per_user_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 != SNAT_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_out2in_reass_node) = { + .function = nat44_out2in_reass_node_fn, + .name = "nat44-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 = SNAT_OUT2IN_N_NEXT, + + /* edit / add dispositions here */ + .next_nodes = { + [SNAT_OUT2IN_NEXT_DROP] = "error-drop", + [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup", + [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error", + [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass", + }, +}; +VLIB_NODE_FUNCTION_MULTIARCH (nat44_out2in_reass_node, + nat44_out2in_reass_node_fn); + /**************************/ /*** deterministic mode ***/ /**************************/ @@ -2017,6 +2347,7 @@ VLIB_REGISTER_NODE (snat_det_out2in_node) = { [SNAT_OUT2IN_NEXT_DROP] = "error-drop", [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup", [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error", + [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass", }, }; VLIB_NODE_FUNCTION_MULTIARCH (snat_det_out2in_node, snat_det_out2in_node_fn); @@ -2509,6 +2840,7 @@ VLIB_REGISTER_NODE (snat_out2in_fast_node) = { [SNAT_OUT2IN_NEXT_LOOKUP] = "ip4-lookup", [SNAT_OUT2IN_NEXT_DROP] = "error-drop", [SNAT_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error", + [SNAT_OUT2IN_NEXT_REASS] = "nat44-out2in-reass", }, }; VLIB_NODE_FUNCTION_MULTIARCH (snat_out2in_fast_node, snat_out2in_fast_node_fn); |