/* * Copyright (c) 2018 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. */ /** * @file * @brief Classify for one armed NAT44 (in+out interface) */ #include <vlib/vlib.h> #include <vnet/vnet.h> #include <vnet/fib/ip4_fib.h> #include <nat/nat.h> #include <nat/nat_reass.h> #include <nat/nat_inlines.h> #define foreach_nat44_classify_error \ _(MAX_REASS, "Maximum reassemblies exceeded") \ _(MAX_FRAG, "Maximum fragments per reassembly exceeded") \ _(NEXT_IN2OUT, "next in2out") \ _(NEXT_OUT2IN, "next out2in") \ _(FRAG_CACHED, "fragment cached") typedef enum { #define _(sym,str) NAT44_CLASSIFY_ERROR_##sym, foreach_nat44_classify_error #undef _ NAT44_CLASSIFY_N_ERROR, } nat44_classify_error_t; static char *nat44_classify_error_strings[] = { #define _(sym,string) string, foreach_nat44_classify_error #undef _ }; typedef enum { NAT44_CLASSIFY_NEXT_IN2OUT, NAT44_CLASSIFY_NEXT_OUT2IN, NAT44_CLASSIFY_NEXT_DROP, NAT44_CLASSIFY_N_NEXT, } nat44_classify_next_t; typedef struct { u8 next_in2out; u8 cached; } nat44_classify_trace_t; static u8 * format_nat44_classify_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_classify_trace_t *t = va_arg (*args, nat44_classify_trace_t *); char *next; if (t->cached) s = format (s, "nat44-classify: fragment cached"); else { next = t->next_in2out ? "nat44-in2out" : "nat44-out2in"; s = format (s, "nat44-classify: next %s", next); } return s; } static inline uword nat44_classify_node_fn_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { u32 n_left_from, *from, *to_next; nat44_classify_next_t next_index; snat_main_t *sm = &snat_main; snat_static_mapping_t *m; u32 thread_index = vm->thread_index; u32 *fragments_to_drop = 0; u32 *fragments_to_loopback = 0; u32 next_in2out = 0, next_out2in = 0, frag_cached = 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; vlib_buffer_t *b0; u32 next0 = NAT44_CLASSIFY_NEXT_IN2OUT; ip4_header_t *ip0; snat_address_t *ap; snat_session_key_t m_key0; clib_bihash_kv_8_8_t kv0, value0; udp_header_t *udp0; nat_reass_ip4_t *reass0; u8 cached0 = 0; /* 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); ip0 = vlib_buffer_get_current (b0); udp0 = ip4_next_header (ip0); /* *INDENT-OFF* */ vec_foreach (ap, sm->addresses) { if (ip0->dst_address.as_u32 == ap->addr.as_u32) { next0 = NAT44_CLASSIFY_NEXT_OUT2IN; goto enqueue0; } } /* *INDENT-ON* */ if (PREDICT_FALSE (pool_elts (sm->static_mappings))) { m_key0.addr = ip0->dst_address; m_key0.port = 0; m_key0.protocol = 0; m_key0.fib_index = 0; kv0.key = m_key0.as_u64; /* try to classify the fragment based on IP header alone */ if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv0, &value0)) { m = pool_elt_at_index (sm->static_mappings, value0.value); if (m->local_addr.as_u32 != m->external_addr.as_u32) next0 = NAT44_CLASSIFY_NEXT_OUT2IN; goto enqueue0; } if (!ip4_is_fragment (ip0) || ip4_is_first_fragment (ip0)) { /* process leading fragment/whole packet (with L4 header) */ m_key0.port = clib_net_to_host_u16 (udp0->dst_port); m_key0.protocol = ip_proto_to_snat_proto (ip0->protocol); kv0.key = m_key0.as_u64; if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv0, &value0)) { m = pool_elt_at_index (sm->static_mappings, value0.value); if (m->local_addr.as_u32 != m->external_addr.as_u32) next0 = NAT44_CLASSIFY_NEXT_OUT2IN; } if (ip4_is_fragment (ip0)) { 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_CLASSIFY_NEXT_DROP; b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS]; nat_elog_notice ("maximum reassemblies exceeded"); goto enqueue0; } /* save classification for future fragments and set past * fragments to be looped over and reprocessed */ if (next0 == NAT44_CLASSIFY_NEXT_OUT2IN) reass0->classify_next = NAT_REASS_IP4_CLASSIFY_NEXT_OUT2IN; else reass0->classify_next = NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT; nat_ip4_reass_get_frags (reass0, &fragments_to_loopback); } } else { /* process non-first fragment */ 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_CLASSIFY_NEXT_DROP; b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS]; nat_elog_notice ("maximum reassemblies exceeded"); goto enqueue0; } if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NONE) /* first fragment still hasn't arrived */ { if (nat_ip4_reass_add_fragment (thread_index, reass0, bi0, &fragments_to_drop)) { b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_FRAG]; nat_elog_notice ("maximum fragments per reassembly exceeded"); next0 = NAT44_CLASSIFY_NEXT_DROP; goto enqueue0; } cached0 = 1; goto enqueue0; } else if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NEXT_OUT2IN) next0 = NAT44_CLASSIFY_NEXT_OUT2IN; else if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT) next0 = NAT44_CLASSIFY_NEXT_IN2OUT; } } enqueue0: if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) && (b0->flags & VLIB_BUFFER_IS_TRACED))) { nat44_classify_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t)); t->cached = cached0; if (!cached0) t->next_in2out = next0 == NAT44_CLASSIFY_NEXT_IN2OUT ? 1 : 0; } if (cached0) { n_left_to_next++; to_next--; frag_cached++; } else { next_in2out += next0 == NAT44_CLASSIFY_NEXT_IN2OUT; next_out2in += next0 == NAT44_CLASSIFY_NEXT_OUT2IN; /* 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_fast (from, fragments_to_loopback, sizeof (u32) * len); n_left_from = len; vec_reset_length (fragments_to_loopback); } else { clib_memcpy_fast (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); } nat_send_all_to_node (vm, fragments_to_drop, node, 0, NAT44_CLASSIFY_NEXT_DROP); vec_free (fragments_to_drop); vlib_node_increment_counter (vm, node->node_index, NAT44_CLASSIFY_ERROR_NEXT_IN2OUT, next_in2out); vlib_node_increment_counter (vm, node->node_index, NAT44_CLASSIFY_ERROR_NEXT_OUT2IN, next_out2in); vlib_node_increment_counter (vm, node->node_index, NAT44_CLASSIFY_ERROR_FRAG_CACHED, frag_cached); return frame->n_vectors; } static inline uword nat44_ed_classify_node_fn_inline (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { u32 n_left_from, *from, *to_next; nat44_classify_next_t next_index; snat_main_t *sm = &snat_main; snat_static_mapping_t *m; u32 thread_index = vm->thread_index; snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index]; u32 *fragments_to_drop = 0; u32 *fragments_to_loopback = 0; u32 next_in2out = 0, next_out2in = 0, frag_cached = 0; u8 in_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; vlib_buffer_t *b0; u32 next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH, sw_if_index0, rx_fib_index0; ip4_header_t *ip0; snat_address_t *ap; snat_session_key_t m_key0; clib_bihash_kv_8_8_t kv0, value0; clib_bihash_kv_16_8_t ed_kv0, ed_value0; udp_header_t *udp0; nat_reass_ip4_t *reass0; u8 cached0 = 0; /* 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); ip0 = vlib_buffer_get_current (b0); udp0 = ip4_next_header (ip0); if (!in_loopback) { u32 arc_next = 0; vnet_feature_next (&arc_next, b0); nat_buffer_opaque (b0)->arc_next = arc_next; } if (ip0->protocol != IP_PROTOCOL_ICMP) { if (!ip4_is_fragment (ip0) || ip4_is_first_fragment (ip0)) { /* process leading fragment/whole packet (with L4 header) */ 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); make_ed_kv (&ed_kv0, &ip0->src_address, &ip0->dst_address, ip0->protocol, rx_fib_index0, udp0->src_port, udp0->dst_port); if (ip4_is_fragment (ip0)) { 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 = NAT_NEXT_DROP; b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS]; nat_elog_notice ("maximum reassemblies exceeded"); goto enqueue0; } if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &ed_kv0, &ed_value0)) { /* session exists so classify as IN2OUT, * save this information for future fragments and set * past fragments to be looped over and reprocessed */ reass0->sess_index = ed_value0.value; reass0->classify_next = NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT; nat_ip4_reass_get_frags (reass0, &fragments_to_loopback); goto enqueue0; } else { /* session doesn't exist so continue in the code, * save this information for future fragments and set * past fragments to be looped over and reprocessed */ reass0->flags |= NAT_REASS_FLAG_CLASSIFY_ED_CONTINUE; nat_ip4_reass_get_frags (reass0, &fragments_to_loopback); } } else { /* process whole packet */ if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &ed_kv0, &ed_value0)) goto enqueue0; /* session doesn't exist so continue in code */ } } else { /* process non-first fragment */ 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 = NAT_NEXT_DROP; b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS]; nat_elog_notice ("maximum reassemblies exceeded"); goto enqueue0; } /* check if first fragment has arrived */ if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NONE && !(reass0->flags & NAT_REASS_FLAG_CLASSIFY_ED_CONTINUE)) { /* first fragment still hasn't arrived, cache this fragment */ if (nat_ip4_reass_add_fragment (thread_index, reass0, bi0, &fragments_to_drop)) { b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_FRAG]; nat_elog_notice ("maximum fragments per reassembly exceeded"); next0 = NAT_NEXT_DROP; goto enqueue0; } cached0 = 1; goto enqueue0; } if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT) goto enqueue0; /* flag NAT_REASS_FLAG_CLASSIFY_ED_CONTINUE is set * so keep the default next0 and continue in code to * potentially find other classification for this packet */ } } /* *INDENT-OFF* */ vec_foreach (ap, sm->addresses) { if (ip0->dst_address.as_u32 == ap->addr.as_u32) { next0 = NAT_NEXT_OUT2IN_ED_FAST_PATH; goto enqueue0; } } /* *INDENT-ON* */ if (PREDICT_FALSE (pool_elts (sm->static_mappings))) { m_key0.addr = ip0->dst_address; m_key0.port = 0; m_key0.protocol = 0; m_key0.fib_index = 0; kv0.key = m_key0.as_u64; /* try to classify the fragment based on IP header alone */ if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv0, &value0)) { m = pool_elt_at_index (sm->static_mappings, value0.value); if (m->local_addr.as_u32 != m->external_addr.as_u32) next0 = NAT_NEXT_OUT2IN_ED_FAST_PATH; goto enqueue0; } if (!ip4_is_fragment (ip0) || ip4_is_first_fragment (ip0)) { /* process leading fragment/whole packet (with L4 header) */ m_key0.port = clib_net_to_host_u16 (udp0->dst_port); m_key0.protocol = ip_proto_to_snat_proto (ip0->protocol); kv0.key = m_key0.as_u64; if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv0, &value0)) { m = pool_elt_at_index (sm->static_mappings, value0.value); if (m->local_addr.as_u32 != m->external_addr.as_u32) next0 = NAT_NEXT_OUT2IN_ED_FAST_PATH; } if (ip4_is_fragment (ip0)) { 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 = NAT_NEXT_DROP; b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS]; nat_elog_notice ("maximum reassemblies exceeded"); goto enqueue0; } /* save classification for future fragments and set past * fragments to be looped over and reprocessed */ if (next0 == NAT_NEXT_OUT2IN_ED_FAST_PATH) reass0->classify_next = NAT_NEXT_OUT2IN_ED_REASS; else reass0->classify_next = NAT_NEXT_IN2OUT_ED_REASS; nat_ip4_reass_get_frags (reass0, &fragments_to_loopback); } } else { /* process non-first fragment */ 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 = NAT_NEXT_DROP; b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS]; nat_elog_notice ("maximum reassemblies exceeded"); goto enqueue0; } if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NONE) /* first fragment still hasn't arrived */ { if (nat_ip4_reass_add_fragment (thread_index, reass0, bi0, &fragments_to_drop)) { b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_FRAG]; nat_elog_notice ("maximum fragments per reassembly exceeded"); next0 = NAT_NEXT_DROP; goto enqueue0; } cached0 = 1; goto enqueue0; } else if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NEXT_OUT2IN) next0 = NAT_NEXT_OUT2IN_ED_FAST_PATH; else if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT) next0 = NAT_NEXT_IN2OUT_ED_FAST_PATH; } } enqueue0: if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) && (b0->flags & VLIB_BUFFER_IS_TRACED))) { nat44_classify_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t)); t->cached = cached0; if (!cached0) t->next_in2out = next0 == NAT_NEXT_IN2OUT_ED_FAST_PATH ? 1 : 0; } if (cached0) { n_left_to_next++; to_next--; frag_cached++; } else { next_in2out += next0 == NAT_NEXT_IN2OUT_ED_FAST_PATH; next_out2in += next0 == NAT_NEXT_OUT2IN_ED_FAST_PATH; /* 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)) { in_loopback = 1; from = vlib_frame_vector_args (frame); u32 len = vec_len (fragments_to_loopback); if (len <= VLIB_FRAME_SIZE) { clib_memcpy_fast (from, fragments_to_loopback, sizeof (u32) * len); n_left_from = len; vec_reset_length (fragments_to_loopback); } else { clib_memcpy_fast (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); } nat_send_all_to_node (vm, fragments_to_drop, node, 0, NAT44_CLASSIFY_NEXT_DROP); vec_free (fragments_to_drop); vlib_node_increment_counter (vm, node->node_index, NAT44_CLASSIFY_ERROR_NEXT_IN2OUT, next_in2out); vlib_node_increment_counter (vm, node->node_index, NAT44_CLASSIFY_ERROR_NEXT_OUT2IN, next_out2in); vlib_node_increment_counter (vm, node->node_index, NAT44_CLASSIFY_ERROR_FRAG_CACHED, frag_cached); return frame->n_vectors; } VLIB_NODE_FN (nat44_classify_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { return nat44_classify_node_fn_inline (vm, node, frame); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (nat44_classify_node) = { .name = "nat44-classify", .vector_size = sizeof (u32), .format_trace = format_nat44_classify_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_errors = ARRAY_LEN(nat44_classify_error_strings), .error_strings = nat44_classify_error_strings, .n_next_nodes = NAT44_CLASSIFY_N_NEXT, .next_nodes = { [NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-in2out", [NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-out2in", [NAT44_CLASSIFY_NEXT_DROP] = "error-drop", }, }; /* *INDENT-ON* */ VLIB_NODE_FN (nat44_ed_classify_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { return nat44_ed_classify_node_fn_inline (vm, node, frame); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (nat44_ed_classify_node) = { .name = "nat44-ed-classify", .vector_size = sizeof (u32), .sibling_of = "nat-default", .format_trace = format_nat44_classify_trace, .type = VLIB_NODE_TYPE_INTERNAL, }; /* *INDENT-ON* */ VLIB_NODE_FN (nat44_det_classify_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { return nat44_classify_node_fn_inline (vm, node, frame); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (nat44_det_classify_node) = { .name = "nat44-det-classify", .vector_size = sizeof (u32), .format_trace = format_nat44_classify_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_next_nodes = NAT44_CLASSIFY_N_NEXT, .next_nodes = { [NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-det-in2out", [NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-det-out2in", [NAT44_CLASSIFY_NEXT_DROP] = "error-drop", }, }; /* *INDENT-ON* */ VLIB_NODE_FN (nat44_handoff_classify_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { return nat44_classify_node_fn_inline (vm, node, frame); } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (nat44_handoff_classify_node) = { .name = "nat44-handoff-classify", .vector_size = sizeof (u32), .format_trace = format_nat44_classify_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_next_nodes = NAT44_CLASSIFY_N_NEXT, .next_nodes = { [NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-in2out-worker-handoff", [NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-out2in-worker-handoff", [NAT44_CLASSIFY_NEXT_DROP] = "error-drop", }, }; /* *INDENT-ON* */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */