/* * 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 Deterministic/CGN NAT44 outside to inside network translation */ #include <vlib/vlib.h> #include <vnet/vnet.h> #include <vnet/ip/ip.h> #include <vnet/fib/ip4_fib.h> #include <vppinfra/error.h> #include <vppinfra/elog.h> #include <nat/nat.h> #include <nat/nat_det.h> #include <nat/nat_inlines.h> typedef enum { NAT_DET_OUT2IN_NEXT_DROP, NAT_DET_OUT2IN_NEXT_LOOKUP, NAT_DET_OUT2IN_NEXT_ICMP_ERROR, NAT_DET_OUT2IN_N_NEXT, } nat_det_out2in_next_t; typedef struct { u32 sw_if_index; u32 next_index; u32 session_index; } nat_det_out2in_trace_t; #define foreach_nat_det_out2in_error \ _(UNSUPPORTED_PROTOCOL, "Unsupported protocol") \ _(NO_TRANSLATION, "No translation") \ _(BAD_ICMP_TYPE, "unsupported ICMP type") \ _(OUT2IN_PACKETS, "Good out2in packets processed") typedef enum { #define _(sym,str) NAT_DET_OUT2IN_ERROR_##sym, foreach_nat_det_out2in_error #undef _ SNAT_OUT2IN_N_ERROR, } nat_det_out2in_error_t; static char *nat_det_out2in_error_strings[] = { #define _(sym,string) string, foreach_nat_det_out2in_error #undef _ }; static u8 * format_nat_det_out2in_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 *); nat_det_out2in_trace_t *t = va_arg (*args, nat_det_out2in_trace_t *); s = format (s, "NAT_DET_OUT2IN: sw_if_index %d, next index %d, session index %d", t->sw_if_index, t->next_index, t->session_index); return s; } #ifndef CLIB_MARCH_VARIANT /** * Get address and port values to be used for ICMP packet translation * and create session if needed * * @param[in,out] sm NAT main * @param[in,out] node NAT node runtime * @param[in] thread_index thread index * @param[in,out] b0 buffer containing packet to be translated * @param[out] p_proto protocol used for matching * @param[out] p_value address and port after NAT translation * @param[out] p_dont_translate if packet should not be translated * @param d optional parameter * @param e optional parameter */ u32 icmp_match_out2in_det (snat_main_t * sm, vlib_node_runtime_t * node, u32 thread_index, vlib_buffer_t * b0, ip4_header_t * ip0, u8 * p_proto, snat_session_key_t * p_value, u8 * p_dont_translate, void *d, void *e) { icmp46_header_t *icmp0; u32 sw_if_index0; u8 protocol; snat_det_out_key_t key0; u8 dont_translate = 0; u32 next0 = ~0; icmp_echo_header_t *echo0, *inner_echo0 = 0; ip4_header_t *inner_ip0; void *l4_header = 0; icmp46_header_t *inner_icmp0; snat_det_map_t *dm0 = 0; ip4_address_t new_addr0 = { {0} }; snat_det_session_t *ses0 = 0; ip4_address_t out_addr; icmp0 = (icmp46_header_t *) ip4_next_header (ip0); echo0 = (icmp_echo_header_t *) (icmp0 + 1); sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX]; if (!icmp_is_error_message (icmp0)) { protocol = SNAT_PROTOCOL_ICMP; key0.ext_host_addr = ip0->src_address; key0.ext_host_port = 0; key0.out_port = echo0->identifier; out_addr = ip0->dst_address; } else { inner_ip0 = (ip4_header_t *) (echo0 + 1); l4_header = ip4_next_header (inner_ip0); protocol = ip_proto_to_snat_proto (inner_ip0->protocol); key0.ext_host_addr = inner_ip0->dst_address; out_addr = inner_ip0->src_address; switch (protocol) { case SNAT_PROTOCOL_ICMP: inner_icmp0 = (icmp46_header_t *) l4_header; inner_echo0 = (icmp_echo_header_t *) (inner_icmp0 + 1); key0.ext_host_port = 0; key0.out_port = inner_echo0->identifier; break; case SNAT_PROTOCOL_UDP: case SNAT_PROTOCOL_TCP: key0.ext_host_port = ((tcp_udp_header_t *) l4_header)->dst_port; key0.out_port = ((tcp_udp_header_t *) l4_header)->src_port; break; default: b0->error = node->errors[NAT_DET_OUT2IN_ERROR_UNSUPPORTED_PROTOCOL]; next0 = NAT_DET_OUT2IN_NEXT_DROP; goto out; } } dm0 = snat_det_map_by_out (sm, &out_addr); if (PREDICT_FALSE (!dm0)) { /* Don't NAT packet aimed at the intfc address */ if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index0, ip0->dst_address.as_u32))) { dont_translate = 1; goto out; } nat_log_info ("unknown dst address: %U", format_ip4_address, &ip0->dst_address); goto out; } snat_det_reverse (dm0, &ip0->dst_address, clib_net_to_host_u16 (key0.out_port), &new_addr0); ses0 = snat_det_get_ses_by_out (dm0, &new_addr0, key0.as_u64); if (PREDICT_FALSE (!ses0)) { /* Don't NAT packet aimed at the intfc address */ if (PREDICT_FALSE (is_interface_addr (sm, node, sw_if_index0, ip0->dst_address.as_u32))) { dont_translate = 1; goto out; } nat_log_info ("no match src %U:%d dst %U:%d for user %U", format_ip4_address, &key0.ext_host_addr, clib_net_to_host_u16 (key0.ext_host_port), format_ip4_address, &out_addr, clib_net_to_host_u16 (key0.out_port), format_ip4_address, &new_addr0); b0->error = node->errors[NAT_DET_OUT2IN_ERROR_NO_TRANSLATION]; next0 = NAT_DET_OUT2IN_NEXT_DROP; goto out; } if (PREDICT_FALSE (icmp0->type != ICMP4_echo_reply && !icmp_is_error_message (icmp0))) { b0->error = node->errors[NAT_DET_OUT2IN_ERROR_BAD_ICMP_TYPE]; next0 = NAT_DET_OUT2IN_NEXT_DROP; goto out; } goto out; out: *p_proto = protocol; if (ses0) { p_value->addr = new_addr0; p_value->fib_index = sm->inside_fib_index; p_value->port = ses0->in_port; } *p_dont_translate = dont_translate; if (d) *(snat_det_session_t **) d = ses0; if (e) *(snat_det_map_t **) e = dm0; return next0; } #endif VLIB_NODE_FN (snat_det_out2in_node) (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { u32 n_left_from, *from, *to_next; nat_det_out2in_next_t next_index; u32 pkts_processed = 0; snat_main_t *sm = &snat_main; u32 thread_index = vm->thread_index; 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 >= 4 && n_left_to_next >= 2) { u32 bi0, bi1; vlib_buffer_t *b0, *b1; u32 next0 = NAT_DET_OUT2IN_NEXT_LOOKUP; u32 next1 = NAT_DET_OUT2IN_NEXT_LOOKUP; u32 sw_if_index0, sw_if_index1; ip4_header_t *ip0, *ip1; ip_csum_t sum0, sum1; ip4_address_t new_addr0, old_addr0, new_addr1, old_addr1; u16 new_port0, old_port0, old_port1, new_port1; udp_header_t *udp0, *udp1; tcp_header_t *tcp0, *tcp1; u32 proto0, proto1; snat_det_out_key_t key0, key1; snat_det_map_t *dm0, *dm1; snat_det_session_t *ses0 = 0, *ses1 = 0; u32 rx_fib_index0, rx_fib_index1; icmp46_header_t *icmp0, *icmp1; /* Prefetch next iteration. */ { vlib_buffer_t *p2, *p3; p2 = vlib_get_buffer (vm, from[2]); p3 = vlib_get_buffer (vm, from[3]); vlib_prefetch_buffer_header (p2, LOAD); vlib_prefetch_buffer_header (p3, LOAD); CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, STORE); CLIB_PREFETCH (p3->data, CLIB_CACHE_LINE_BYTES, STORE); } /* speculatively enqueue b0 and b1 to the current next frame */ to_next[0] = bi0 = from[0]; to_next[1] = bi1 = from[1]; from += 2; to_next += 2; n_left_from -= 2; n_left_to_next -= 2; b0 = vlib_get_buffer (vm, bi0); b1 = vlib_get_buffer (vm, bi1); ip0 = vlib_buffer_get_current (b0); udp0 = ip4_next_header (ip0); tcp0 = (tcp_header_t *) udp0; sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX]; if (PREDICT_FALSE (ip0->ttl == 1)) { vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0; icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded, ICMP4_time_exceeded_ttl_exceeded_in_transit, 0); next0 = NAT_DET_OUT2IN_NEXT_ICMP_ERROR; goto trace0; } proto0 = ip_proto_to_snat_proto (ip0->protocol); if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP)) { rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0); icmp0 = (icmp46_header_t *) udp0; next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node, next0, thread_index, &ses0, &dm0); goto trace0; } key0.ext_host_addr = ip0->src_address; key0.ext_host_port = tcp0->src; key0.out_port = tcp0->dst; dm0 = snat_det_map_by_out (sm, &ip0->dst_address); if (PREDICT_FALSE (!dm0)) { nat_log_info ("unknown dst address: %U", format_ip4_address, &ip0->dst_address); next0 = NAT_DET_OUT2IN_NEXT_DROP; b0->error = node->errors[NAT_DET_OUT2IN_ERROR_NO_TRANSLATION]; goto trace0; } snat_det_reverse (dm0, &ip0->dst_address, clib_net_to_host_u16 (tcp0->dst), &new_addr0); ses0 = snat_det_get_ses_by_out (dm0, &new_addr0, key0.as_u64); if (PREDICT_FALSE (!ses0)) { nat_log_info ("no match src %U:%d dst %U:%d for user %U", format_ip4_address, &ip0->src_address, clib_net_to_host_u16 (tcp0->src), format_ip4_address, &ip0->dst_address, clib_net_to_host_u16 (tcp0->dst), format_ip4_address, &new_addr0); next0 = NAT_DET_OUT2IN_NEXT_DROP; b0->error = node->errors[NAT_DET_OUT2IN_ERROR_NO_TRANSLATION]; goto trace0; } new_port0 = ses0->in_port; old_addr0 = ip0->dst_address; ip0->dst_address = new_addr0; vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm->inside_fib_index; sum0 = ip0->checksum; sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32, ip4_header_t, dst_address /* changed member */ ); ip0->checksum = ip_csum_fold (sum0); if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP)) { if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_ESTABLISHED) ses0->state = SNAT_SESSION_TCP_CLOSE_WAIT; else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_LAST_ACK) snat_det_ses_close (dm0, ses0); old_port0 = tcp0->dst; tcp0->dst = new_port0; sum0 = tcp0->checksum; sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32, 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 = new_port0; udp0->checksum = 0; } trace0: if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) && (b0->flags & VLIB_BUFFER_IS_TRACED))) { nat_det_out2in_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t)); t->sw_if_index = sw_if_index0; t->next_index = next0; t->session_index = ~0; if (ses0) t->session_index = ses0 - dm0->sessions; } pkts_processed += next0 != NAT_DET_OUT2IN_NEXT_DROP; b1 = vlib_get_buffer (vm, bi1); ip1 = vlib_buffer_get_current (b1); udp1 = ip4_next_header (ip1); tcp1 = (tcp_header_t *) udp1; sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX]; if (PREDICT_FALSE (ip1->ttl == 1)) { vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0; icmp4_error_set_vnet_buffer (b1, ICMP4_time_exceeded, ICMP4_time_exceeded_ttl_exceeded_in_transit, 0); next1 = NAT_DET_OUT2IN_NEXT_ICMP_ERROR; goto trace1; } proto1 = ip_proto_to_snat_proto (ip1->protocol); if (PREDICT_FALSE (proto1 == SNAT_PROTOCOL_ICMP)) { rx_fib_index1 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index1); icmp1 = (icmp46_header_t *) udp1; next1 = icmp_out2in (sm, b1, ip1, icmp1, sw_if_index1, rx_fib_index1, node, next1, thread_index, &ses1, &dm1); goto trace1; } key1.ext_host_addr = ip1->src_address; key1.ext_host_port = tcp1->src; key1.out_port = tcp1->dst; dm1 = snat_det_map_by_out (sm, &ip1->dst_address); if (PREDICT_FALSE (!dm1)) { nat_log_info ("unknown dst address: %U", format_ip4_address, &ip1->dst_address); next1 = NAT_DET_OUT2IN_NEXT_DROP; b1->error = node->errors[NAT_DET_OUT2IN_ERROR_NO_TRANSLATION]; goto trace1; } snat_det_reverse (dm1, &ip1->dst_address, clib_net_to_host_u16 (tcp1->dst), &new_addr1); ses1 = snat_det_get_ses_by_out (dm1, &new_addr1, key1.as_u64); if (PREDICT_FALSE (!ses1)) { nat_log_info ("no match src %U:%d dst %U:%d for user %U", format_ip4_address, &ip1->src_address, clib_net_to_host_u16 (tcp1->src), format_ip4_address, &ip1->dst_address, clib_net_to_host_u16 (tcp1->dst), format_ip4_address, &new_addr1); next1 = NAT_DET_OUT2IN_NEXT_DROP; b1->error = node->errors[NAT_DET_OUT2IN_ERROR_NO_TRANSLATION]; goto trace1; } new_port1 = ses1->in_port; old_addr1 = ip1->dst_address; ip1->dst_address = new_addr1; vnet_buffer (b1)->sw_if_index[VLIB_TX] = sm->inside_fib_index; sum1 = ip1->checksum; sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32, ip4_header_t, dst_address /* changed member */ ); ip1->checksum = ip_csum_fold (sum1); if (PREDICT_TRUE (proto1 == SNAT_PROTOCOL_TCP)) { if (tcp1->flags & TCP_FLAG_FIN && ses1->state == SNAT_SESSION_TCP_ESTABLISHED) ses1->state = SNAT_SESSION_TCP_CLOSE_WAIT; else if (tcp1->flags & TCP_FLAG_ACK && ses1->state == SNAT_SESSION_TCP_LAST_ACK) snat_det_ses_close (dm1, ses1); old_port1 = tcp1->dst; tcp1->dst = new_port1; sum1 = tcp1->checksum; sum1 = ip_csum_update (sum1, old_addr1.as_u32, new_addr1.as_u32, ip4_header_t, dst_address /* changed member */ ); sum1 = ip_csum_update (sum1, old_port1, new_port1, ip4_header_t /* cheat */ , length /* changed member */ ); tcp1->checksum = ip_csum_fold (sum1); } else { old_port1 = udp1->dst_port; udp1->dst_port = new_port1; udp1->checksum = 0; } trace1: if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) && (b1->flags & VLIB_BUFFER_IS_TRACED))) { nat_det_out2in_trace_t *t = vlib_add_trace (vm, node, b1, sizeof (*t)); t->sw_if_index = sw_if_index1; t->next_index = next1; t->session_index = ~0; if (ses1) t->session_index = ses1 - dm1->sessions; } pkts_processed += next1 != NAT_DET_OUT2IN_NEXT_DROP; /* verify speculative enqueues, maybe switch current next frame */ vlib_validate_buffer_enqueue_x2 (vm, node, next_index, to_next, n_left_to_next, bi0, bi1, next0, next1); } while (n_left_from > 0 && n_left_to_next > 0) { u32 bi0; vlib_buffer_t *b0; u32 next0 = NAT_DET_OUT2IN_NEXT_LOOKUP; u32 sw_if_index0; ip4_header_t *ip0; ip_csum_t sum0; ip4_address_t new_addr0, old_addr0; u16 new_port0, old_port0; udp_header_t *udp0; tcp_header_t *tcp0; u32 proto0; snat_det_out_key_t key0; snat_det_map_t *dm0; snat_det_session_t *ses0 = 0; u32 rx_fib_index0; icmp46_header_t *icmp0; /* 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); tcp0 = (tcp_header_t *) udp0; sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX]; if (PREDICT_FALSE (ip0->ttl == 1)) { vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0; icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded, ICMP4_time_exceeded_ttl_exceeded_in_transit, 0); next0 = NAT_DET_OUT2IN_NEXT_ICMP_ERROR; goto trace00; } proto0 = ip_proto_to_snat_proto (ip0->protocol); if (PREDICT_FALSE (proto0 == SNAT_PROTOCOL_ICMP)) { rx_fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0); icmp0 = (icmp46_header_t *) udp0; next0 = icmp_out2in (sm, b0, ip0, icmp0, sw_if_index0, rx_fib_index0, node, next0, thread_index, &ses0, &dm0); goto trace00; } key0.ext_host_addr = ip0->src_address; key0.ext_host_port = tcp0->src; key0.out_port = tcp0->dst; dm0 = snat_det_map_by_out (sm, &ip0->dst_address); if (PREDICT_FALSE (!dm0)) { nat_log_info ("unknown dst address: %U", format_ip4_address, &ip0->dst_address); next0 = NAT_DET_OUT2IN_NEXT_DROP; b0->error = node->errors[NAT_DET_OUT2IN_ERROR_NO_TRANSLATION]; goto trace00; } snat_det_reverse (dm0, &ip0->dst_address, clib_net_to_host_u16 (tcp0->dst), &new_addr0); ses0 = snat_det_get_ses_by_out (dm0, &new_addr0, key0.as_u64); if (PREDICT_FALSE (!ses0)) { nat_log_info ("no match src %U:%d dst %U:%d for user %U", format_ip4_address, &ip0->src_address, clib_net_to_host_u16 (tcp0->src), format_ip4_address, &ip0->dst_address, clib_net_to_host_u16 (tcp0->dst), format_ip4_address, &new_addr0); next0 = NAT_DET_OUT2IN_NEXT_DROP; b0->error = node->errors[NAT_DET_OUT2IN_ERROR_NO_TRANSLATION]; goto trace00; } new_port0 = ses0->in_port; old_addr0 = ip0->dst_address; ip0->dst_address = new_addr0; vnet_buffer (b0)->sw_if_index[VLIB_TX] = sm->inside_fib_index; sum0 = ip0->checksum; sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32, ip4_header_t, dst_address /* changed member */ ); ip0->checksum = ip_csum_fold (sum0); if (PREDICT_TRUE (proto0 == SNAT_PROTOCOL_TCP)) { if (tcp0->flags & TCP_FLAG_FIN && ses0->state == SNAT_SESSION_TCP_ESTABLISHED) ses0->state = SNAT_SESSION_TCP_CLOSE_WAIT; else if (tcp0->flags & TCP_FLAG_ACK && ses0->state == SNAT_SESSION_TCP_LAST_ACK) snat_det_ses_close (dm0, ses0); old_port0 = tcp0->dst; tcp0->dst = new_port0; sum0 = tcp0->checksum; sum0 = ip_csum_update (sum0, old_addr0.as_u32, new_addr0.as_u32, 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 = new_port0; udp0->checksum = 0; } trace00: if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) && (b0->flags & VLIB_BUFFER_IS_TRACED))) { nat_det_out2in_trace_t *t = vlib_add_trace (vm, node, b0, sizeof (*t)); t->sw_if_index = sw_if_index0; t->next_index = next0; t->session_index = ~0; if (ses0) t->session_index = ses0 - dm0->sessions; } pkts_processed += next0 != NAT_DET_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); } vlib_put_next_frame (vm, node, next_index, n_left_to_next); } vlib_node_increment_counter (vm, sm->det_out2in_node_index, NAT_DET_OUT2IN_ERROR_OUT2IN_PACKETS, pkts_processed); return frame->n_vectors; } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (snat_det_out2in_node) = { .name = "nat44-det-out2in", .vector_size = sizeof (u32), .format_trace = format_nat_det_out2in_trace, .type = VLIB_NODE_TYPE_INTERNAL, .n_errors = ARRAY_LEN(nat_det_out2in_error_strings), .error_strings = nat_det_out2in_error_strings, .runtime_data_bytes = sizeof (snat_runtime_t), .n_next_nodes = NAT_DET_OUT2IN_N_NEXT, /* edit / add dispositions here */ .next_nodes = { [NAT_DET_OUT2IN_NEXT_DROP] = "error-drop", [NAT_DET_OUT2IN_NEXT_LOOKUP] = "ip4-lookup", [NAT_DET_OUT2IN_NEXT_ICMP_ERROR] = "ip4-icmp-error", }, }; /* *INDENT-ON* */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */