/* * Copyright (c) 2015 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. */ /* * ip/icmp4.c: ipv4 icmp * * Copyright (c) 2008 Eliot Dresselhaus * * Permission is hereby granted, free of charge, to any person obtaining * a copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sublicense, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice shall be * included in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ #include <vlib/vlib.h> #include <vnet/ip/ip.h> #include <vnet/pg/pg.h> static char *icmp_error_strings[] = { #define _(f,s) s, foreach_icmp4_error #undef _ }; static u8 * format_ip4_icmp_type_and_code (u8 * s, va_list * args) { icmp4_type_t type = va_arg (*args, int); u8 code = va_arg (*args, int); char *t = 0; #define _(n,f) case n: t = #f; break; switch (type) { foreach_icmp4_type; default: break; } #undef _ if (!t) return format (s, "unknown 0x%x", type); s = format (s, "%s", t); t = 0; switch ((type << 8) | code) { #define _(a,n,f) case (ICMP4_##a << 8) | (n): t = #f; break; foreach_icmp4_code; #undef _ } if (t) s = format (s, " %s", t); return s; } static u8 * format_ip4_icmp_header (u8 * s, va_list * args) { icmp46_header_t *icmp = va_arg (*args, icmp46_header_t *); u32 max_header_bytes = va_arg (*args, u32); /* Nothing to do. */ if (max_header_bytes < sizeof (icmp[0])) return format (s, "ICMP header truncated"); s = format (s, "ICMP %U checksum 0x%x", format_ip4_icmp_type_and_code, icmp->type, icmp->code, clib_net_to_host_u16 (icmp->checksum)); return s; } static u8 * format_icmp_input_trace (u8 * s, va_list * va) { CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *); CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *); icmp_input_trace_t *t = va_arg (*va, icmp_input_trace_t *); s = format (s, "%U", format_ip4_header, t->packet_data, sizeof (t->packet_data)); return s; } typedef enum { ICMP_INPUT_NEXT_ERROR, ICMP_INPUT_N_NEXT, } icmp_input_next_t; typedef struct { uword *type_and_code_by_name; uword *type_by_name; /* Vector dispatch table indexed by [icmp type]. */ u8 ip4_input_next_index_by_type[256]; } icmp4_main_t; icmp4_main_t icmp4_main; static uword ip4_icmp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { icmp4_main_t *im = &icmp4_main; uword n_packets = frame->n_vectors; u32 *from, *to_next; u32 n_left_from, n_left_to_next, next; from = vlib_frame_vector_args (frame); n_left_from = n_packets; next = node->cached_next_index; if (node->flags & VLIB_NODE_FLAG_TRACE) vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors, /* stride */ 1, sizeof (icmp_input_trace_t)); while (n_left_from > 0) { vlib_get_next_frame (vm, node, next, to_next, n_left_to_next); while (n_left_from > 0 && n_left_to_next > 0) { vlib_buffer_t *p0; ip4_header_t *ip0; icmp46_header_t *icmp0; icmp4_type_t type0; u32 bi0, next0; if (PREDICT_TRUE (n_left_from > 2)) { vlib_prefetch_buffer_with_index (vm, from[2], LOAD); p0 = vlib_get_buffer (vm, from[1]); ip0 = vlib_buffer_get_current (p0); CLIB_PREFETCH (ip0, CLIB_CACHE_LINE_BYTES, LOAD); } bi0 = to_next[0] = from[0]; from += 1; n_left_from -= 1; to_next += 1; n_left_to_next -= 1; p0 = vlib_get_buffer (vm, bi0); ip0 = vlib_buffer_get_current (p0); icmp0 = ip4_next_header (ip0); type0 = icmp0->type; next0 = im->ip4_input_next_index_by_type[type0]; p0->error = node->errors[ICMP4_ERROR_UNKNOWN_TYPE]; if (PREDICT_FALSE (next0 != next)) { vlib_put_next_frame (vm, node, next, n_left_to_next + 1); next = next0; vlib_get_next_frame (vm, node, next, to_next, n_left_to_next); to_next[0] = bi0; to_next += 1; n_left_to_next -= 1; } } vlib_put_next_frame (vm, node, next, n_left_to_next); } return frame->n_vectors; } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (ip4_icmp_input_node,static) = { .function = ip4_icmp_input, .name = "ip4-icmp-input", .vector_size = sizeof (u32), .format_trace = format_icmp_input_trace, .n_errors = ARRAY_LEN (icmp_error_strings), .error_strings = icmp_error_strings, .n_next_nodes = 1, .next_nodes = { [ICMP_INPUT_NEXT_ERROR] = "ip4-punt", }, }; /* *INDENT-ON* */ static uword ip4_icmp_echo_request (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { uword n_packets = frame->n_vectors; u32 *from, *to_next; u32 n_left_from, n_left_to_next, next; ip4_main_t *i4m = &ip4_main; u16 *fragment_ids, *fid; u8 host_config_ttl = i4m->host_config.ttl; from = vlib_frame_vector_args (frame); n_left_from = n_packets; next = node->cached_next_index; if (node->flags & VLIB_NODE_FLAG_TRACE) vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors, /* stride */ 1, sizeof (icmp_input_trace_t)); /* Get random fragment IDs for replies. */ fid = fragment_ids = clib_random_buffer_get_data (&vm->random_buffer, n_packets * sizeof (fragment_ids[0])); while (n_left_from > 0) { vlib_get_next_frame (vm, node, next, to_next, n_left_to_next); while (n_left_from > 2 && n_left_to_next > 2) { vlib_buffer_t *p0, *p1; ip4_header_t *ip0, *ip1; icmp46_header_t *icmp0, *icmp1; u32 bi0, src0, dst0; u32 bi1, src1, dst1; ip_csum_t sum0, sum1; bi0 = to_next[0] = from[0]; bi1 = to_next[1] = from[1]; from += 2; n_left_from -= 2; to_next += 2; n_left_to_next -= 2; p0 = vlib_get_buffer (vm, bi0); p1 = vlib_get_buffer (vm, bi1); ip0 = vlib_buffer_get_current (p0); ip1 = vlib_buffer_get_current (p1); icmp0 = ip4_next_header (ip0); icmp1 = ip4_next_header (ip1); vnet_buffer (p0)->sw_if_index[VLIB_RX] = vnet_main.local_interface_sw_if_index; vnet_buffer (p1)->sw_if_index[VLIB_RX] = vnet_main.local_interface_sw_if_index; /* Update ICMP checksum. */ sum0 = icmp0->checksum; sum1 = icmp1->checksum; ASSERT (icmp0->type == ICMP4_echo_request); ASSERT (icmp1->type == ICMP4_echo_request); sum0 = ip_csum_update (sum0, ICMP4_echo_request, ICMP4_echo_reply, icmp46_header_t, type); sum1 = ip_csum_update (sum1, ICMP4_echo_request, ICMP4_echo_reply, icmp46_header_t, type); icmp0->type = ICMP4_echo_reply; icmp1->type = ICMP4_echo_reply; icmp0->checksum = ip_csum_fold (sum0); icmp1->checksum = ip_csum_fold (sum1); src0 = ip0->src_address.data_u32; src1 = ip1->src_address.data_u32; dst0 = ip0->dst_address.data_u32; dst1 = ip1->dst_address.data_u32; /* Swap source and destination address. Does not change checksum. */ ip0->src_address.data_u32 = dst0; ip1->src_address.data_u32 = dst1; ip0->dst_address.data_u32 = src0; ip1->dst_address.data_u32 = src1; /* Update IP checksum. */ sum0 = ip0->checksum; sum1 = ip1->checksum; sum0 = ip_csum_update (sum0, ip0->ttl, host_config_ttl, ip4_header_t, ttl); sum1 = ip_csum_update (sum1, ip1->ttl, host_config_ttl, ip4_header_t, ttl); ip0->ttl = host_config_ttl; ip1->ttl = host_config_ttl; /* New fragment id. */ sum0 = ip_csum_update (sum0, ip0->fragment_id, fid[0], ip4_header_t, fragment_id); sum1 = ip_csum_update (sum1, ip1->fragment_id, fid[1], ip4_header_t, fragment_id); ip0->fragment_id = fid[0]; ip1->fragment_id = fid[1]; fid += 2; ip0->checksum = ip_csum_fold (sum0); ip1->checksum = ip_csum_fold (sum1); ASSERT (ip0->checksum == ip4_header_checksum (ip0)); ASSERT (ip1->checksum == ip4_header_checksum (ip1)); p0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED; p1->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED; } while (n_left_from > 0 && n_left_to_next > 0) { vlib_buffer_t *p0; ip4_header_t *ip0; icmp46_header_t *icmp0; u32 bi0, src0, dst0; ip_csum_t sum0; bi0 = to_next[0] = from[0]; from += 1; n_left_from -= 1; to_next += 1; n_left_to_next -= 1; p0 = vlib_get_buffer (vm, bi0); ip0 = vlib_buffer_get_current (p0); icmp0 = ip4_next_header (ip0); vnet_buffer (p0)->sw_if_index[VLIB_RX] = vnet_main.local_interface_sw_if_index; /* Update ICMP checksum. */ sum0 = icmp0->checksum; ASSERT (icmp0->type == ICMP4_echo_request); sum0 = ip_csum_update (sum0, ICMP4_echo_request, ICMP4_echo_reply, icmp46_header_t, type); icmp0->type = ICMP4_echo_reply; icmp0->checksum = ip_csum_fold (sum0); src0 = ip0->src_address.data_u32; dst0 = ip0->dst_address.data_u32; ip0->src_address.data_u32 = dst0; ip0->dst_address.data_u32 = src0; /* Update IP checksum. */ sum0 = ip0->checksum; sum0 = ip_csum_update (sum0, ip0->ttl, host_config_ttl, ip4_header_t, ttl); ip0->ttl = host_config_ttl; sum0 = ip_csum_update (sum0, ip0->fragment_id, fid[0], ip4_header_t, fragment_id); ip0->fragment_id = fid[0]; fid += 1; ip0->checksum = ip_csum_fold (sum0); ASSERT (ip0->checksum == ip4_header_checksum (ip0)); p0->flags |= VNET_BUFFER_F_LOCALLY_ORIGINATED; } vlib_put_next_frame (vm, node, next, n_left_to_next); } vlib_error_count (vm, ip4_icmp_input_node.index, ICMP4_ERROR_ECHO_REPLIES_SENT, frame->n_vectors); return frame->n_vectors; } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (ip4_icmp_echo_request_node,static) = { .function = ip4_icmp_echo_request, .name = "ip4-icmp-echo-request", .vector_size = sizeof (u32), .format_trace = format_icmp_input_trace, .n_next_nodes = 1, .next_nodes = { [0] = "ip4-load-balance", }, }; /* *INDENT-ON* */ typedef enum { IP4_ICMP_ERROR_NEXT_DROP, IP4_ICMP_ERROR_NEXT_LOOKUP, IP4_ICMP_ERROR_N_NEXT, } ip4_icmp_error_next_t; void icmp4_error_set_vnet_buffer (vlib_buffer_t * b, u8 type, u8 code, u32 data) { vnet_buffer (b)->ip.icmp.type = type; vnet_buffer (b)->ip.icmp.code = code; vnet_buffer (b)->ip.icmp.data = data; } static u8 icmp4_icmp_type_to_error (u8 type) { switch (type) { case ICMP4_destination_unreachable: return ICMP4_ERROR_DEST_UNREACH_SENT; case ICMP4_time_exceeded: return ICMP4_ERROR_TTL_EXPIRE_SENT; case ICMP4_parameter_problem: return ICMP4_ERROR_PARAM_PROBLEM_SENT; default: return ICMP4_ERROR_DROP; } } static uword ip4_icmp_error (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { u32 *from, *to_next; uword n_left_from, n_left_to_next; ip4_icmp_error_next_t next_index; ip4_main_t *im = &ip4_main; ip_lookup_main_t *lm = &im->lookup_main; from = vlib_frame_vector_args (frame); n_left_from = frame->n_vectors; next_index = node->cached_next_index; if (node->flags & VLIB_NODE_FLAG_TRACE) vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors, /* stride */ 1, sizeof (icmp_input_trace_t)); while (n_left_from > 0) { 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 pi0 = from[0]; u32 next0 = IP4_ICMP_ERROR_NEXT_LOOKUP; u8 error0 = ICMP4_ERROR_NONE; vlib_buffer_t *p0; ip4_header_t *ip0, *out_ip0; icmp46_header_t *icmp0; u32 sw_if_index0, if_add_index0; ip_csum_t sum; /* Speculatively enqueue p0 to the current next frame */ to_next[0] = pi0; from += 1; to_next += 1; n_left_from -= 1; n_left_to_next -= 1; p0 = vlib_get_buffer (vm, pi0); ip0 = vlib_buffer_get_current (p0); sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX]; /* * RFC1812 says to keep as much of the original packet as * possible within the minimum MTU (576). We cheat "a little" * here by keeping whatever fits in the first buffer, to be more * efficient */ if (PREDICT_FALSE (p0->total_length_not_including_first_buffer)) { /* clear current_length of all other buffers in chain */ vlib_buffer_t *b = p0; p0->total_length_not_including_first_buffer = 0; while (b->flags & VLIB_BUFFER_NEXT_PRESENT) { b = vlib_get_buffer (vm, b->next_buffer); b->current_length = 0; } } /* Add IP header and ICMPv4 header including a 4 byte data field */ vlib_buffer_advance (p0, -sizeof (ip4_header_t) - sizeof (icmp46_header_t) - 4); p0->current_length = p0->current_length > 576 ? 576 : p0->current_length; out_ip0 = vlib_buffer_get_current (p0); icmp0 = (icmp46_header_t *) & out_ip0[1]; /* Fill ip header fields */ out_ip0->ip_version_and_header_length = 0x45; out_ip0->tos = 0; out_ip0->length = clib_host_to_net_u16 (p0->current_length); out_ip0->fragment_id = 0; out_ip0->flags_and_fragment_offset = 0; out_ip0->ttl = 0xff; out_ip0->protocol = IP_PROTOCOL_ICMP; out_ip0->dst_address = ip0->src_address; if_add_index0 = ~0; if (PREDICT_TRUE (vec_len (lm->if_address_pool_index_by_sw_if_index) > sw_if_index0)) if_add_index0 = lm->if_address_pool_index_by_sw_if_index[sw_if_index0]; if (PREDICT_TRUE (if_add_index0 != ~0)) { ip_interface_address_t *if_add = pool_elt_at_index (lm->if_address_pool, if_add_index0); ip4_address_t *if_ip = ip_interface_address_get_address (lm, if_add); out_ip0->src_address = *if_ip; } else { /* interface has no IP4 address - should not happen */ next0 = IP4_ICMP_ERROR_NEXT_DROP; error0 = ICMP4_ERROR_DROP; } out_ip0->checksum = ip4_header_checksum (out_ip0); /* Fill icmp header fields */ icmp0->type = vnet_buffer (p0)->ip.icmp.type; icmp0->code = vnet_buffer (p0)->ip.icmp.code; *((u32 *) (icmp0 + 1)) = clib_host_to_net_u32 (vnet_buffer (p0)->ip.icmp.data); icmp0->checksum = 0; sum = ip_incremental_checksum (0, icmp0, p0->current_length - sizeof (ip4_header_t)); icmp0->checksum = ~ip_csum_fold (sum); /* Update error status */ if (error0 == ICMP4_ERROR_NONE) error0 = icmp4_icmp_type_to_error (icmp0->type); vlib_error_count (vm, node->node_index, error0, 1); /* Verify speculative enqueue, maybe switch current next frame */ vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, n_left_to_next, pi0, next0); } vlib_put_next_frame (vm, node, next_index, n_left_to_next); } return frame->n_vectors; } /* *INDENT-OFF* */ VLIB_REGISTER_NODE (ip4_icmp_error_node) = { .function = ip4_icmp_error, .name = "ip4-icmp-error", .vector_size = sizeof (u32), .n_errors = ARRAY_LEN (icmp_error_strings), .error_strings = icmp_error_strings, .n_next_nodes = IP4_ICMP_ERROR_N_NEXT, .next_nodes = { [IP4_ICMP_ERROR_NEXT_DROP] = "ip4-drop", [IP4_ICMP_ERROR_NEXT_LOOKUP] = "ip4-lookup", }, .format_trace = format_icmp_input_trace, }; /* *INDENT-ON* */ static uword unformat_icmp_type_and_code (unformat_input_t * input, va_list * args) { icmp46_header_t *h = va_arg (*args, icmp46_header_t *); icmp4_main_t *cm = &icmp4_main; u32 i; if (unformat_user (input, unformat_vlib_number_by_name, cm->type_and_code_by_name, &i)) { h->type = (i >> 8) & 0xff; h->code = (i >> 0) & 0xff; } else if (unformat_user (input, unformat_vlib_number_by_name, cm->type_by_name, &i)) { h->type = i; h->code = 0; } else return 0; return 1; } static void icmp4_pg_edit_function (pg_main_t * pg, pg_stream_t * s, pg_edit_group_t * g, u32 * packets, u32 n_packets) { vlib_main_t *vm = vlib_get_main (); u32 ip_offset, icmp_offset; icmp_offset = g->start_byte_offset; ip_offset = (g - 1)->start_byte_offset; while (n_packets >= 1) { vlib_buffer_t *p0; ip4_header_t *ip0; icmp46_header_t *icmp0; u32 len0; p0 = vlib_get_buffer (vm, packets[0]); n_packets -= 1; packets += 1; ASSERT (p0->current_data == 0); ip0 = (void *) (p0->data + ip_offset); icmp0 = (void *) (p0->data + icmp_offset); /* if IP length has been specified, then calculate the length based on buffer */ if (ip0->length == 0) len0 = vlib_buffer_length_in_chain (vm, p0) - icmp_offset; else len0 = clib_net_to_host_u16 (ip0->length) - icmp_offset; icmp0->checksum = ~ip_csum_fold (ip_incremental_checksum (0, icmp0, len0)); } } typedef struct { pg_edit_t type, code; pg_edit_t checksum; } pg_icmp46_header_t; always_inline void pg_icmp_header_init (pg_icmp46_header_t * p) { /* Initialize fields that are not bit fields in the IP header. */ #define _(f) pg_edit_init (&p->f, icmp46_header_t, f); _(type); _(code); _(checksum); #undef _ } static uword unformat_pg_icmp_header (unformat_input_t * input, va_list * args) { pg_stream_t *s = va_arg (*args, pg_stream_t *); pg_icmp46_header_t *p; u32 group_index; p = pg_create_edit_group (s, sizeof (p[0]), sizeof (icmp46_header_t), &group_index); pg_icmp_header_init (p); p->checksum.type = PG_EDIT_UNSPECIFIED; { icmp46_header_t tmp; if (!unformat (input, "ICMP %U", unformat_icmp_type_and_code, &tmp)) goto error; pg_edit_set_fixed (&p->type, tmp.type); pg_edit_set_fixed (&p->code, tmp.code); } /* Parse options. */ while (1) { if (unformat (input, "checksum %U", unformat_pg_edit, unformat_pg_number, &p->checksum)) ; /* Can't parse input: try next protocol level. */ else break; } if (!unformat_user (input, unformat_pg_payload, s)) goto error; if (p->checksum.type == PG_EDIT_UNSPECIFIED) { pg_edit_group_t *g = pg_stream_get_group (s, group_index); g->edit_function = icmp4_pg_edit_function; g->edit_function_opaque = 0; } return 1; error: /* Free up any edits we may have added. */ pg_free_edit_group (s); return 0; } void ip4_icmp_register_type (vlib_main_t * vm, icmp4_type_t type, u32 node_index) { icmp4_main_t *im = &icmp4_main; ASSERT ((int) type < ARRAY_LEN (im->ip4_input_next_index_by_type)); im->ip4_input_next_index_by_type[type] = vlib_node_add_next (vm, ip4_icmp_input_node.index, node_index); } static clib_error_t * icmp4_init (vlib_main_t * vm) { ip_main_t *im = &ip_main; ip_protocol_info_t *pi; icmp4_main_t *cm = &icmp4_main; clib_error_t *error; error = vlib_call_init_function (vm, ip_main_init); if (error) return error; pi = ip_get_protocol_info (im, IP_PROTOCOL_ICMP); pi->format_header = format_ip4_icmp_header; pi->unformat_pg_edit = unformat_pg_icmp_header; cm->type_by_name = hash_create_string (0, sizeof (uword)); #define _(n,t) hash_set_mem (cm->type_by_name, #t, (n)); foreach_icmp4_type; #undef _ cm->type_and_code_by_name = hash_create_string (0, sizeof (uword)); #define _(a,n,t) hash_set_mem (cm->type_by_name, #t, (n) | (ICMP4_##a << 8)); foreach_icmp4_code; #undef _ clib_memset (cm->ip4_input_next_index_by_type, ICMP_INPUT_NEXT_ERROR, sizeof (cm->ip4_input_next_index_by_type)); ip4_icmp_register_type (vm, ICMP4_echo_request, ip4_icmp_echo_request_node.index); return 0; } VLIB_INIT_FUNCTION (icmp4_init); /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */