/* * ethernet/arp.c: IP v4 ARP node * * Copyright (c) 2010 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. */ #include <vnet/arp/arp.h> #include <vnet/arp/arp_packet.h> #include <vnet/fib/ip4_fib.h> typedef struct { ip4_address_t lo_addr; ip4_address_t hi_addr; u32 fib_index; } ethernet_proxy_arp_t; typedef struct arp_proxy_main_t_ { /** Per interface state */ bool *enabled_by_sw_if_index; /* Proxy arp vector */ ethernet_proxy_arp_t *proxy_arps; } arp_proxy_main_t; arp_proxy_main_t arp_proxy_main; void proxy_arp_walk (proxy_arp_walk_t cb, void *data) { arp_proxy_main_t *am = &arp_proxy_main; ethernet_proxy_arp_t *pa; vec_foreach (pa, am->proxy_arps) { if (!cb (&pa->lo_addr, &pa->hi_addr, pa->fib_index, data)) break; } } int arp_proxy_disable (u32 sw_if_index) { arp_proxy_main_t *am = &arp_proxy_main; vec_validate (am->enabled_by_sw_if_index, sw_if_index); if (am->enabled_by_sw_if_index[sw_if_index]) { vnet_feature_enable_disable ("arp", "arp-proxy", sw_if_index, 0, NULL, 0); } am->enabled_by_sw_if_index[sw_if_index] = false; return (0); } int arp_proxy_enable (u32 sw_if_index) { arp_proxy_main_t *am = &arp_proxy_main; vec_validate (am->enabled_by_sw_if_index, sw_if_index); if (!am->enabled_by_sw_if_index[sw_if_index]) { vnet_feature_enable_disable ("arp", "arp-proxy", sw_if_index, 1, NULL, 0); } am->enabled_by_sw_if_index[sw_if_index] = true; return (0); } static int vnet_proxy_arp_add_del (const ip4_address_t * lo_addr, const ip4_address_t * hi_addr, u32 fib_index, int is_del) { arp_proxy_main_t *am = &arp_proxy_main; ethernet_proxy_arp_t *pa; u32 found_at_index = ~0; vec_foreach (pa, am->proxy_arps) { if (pa->lo_addr.as_u32 == lo_addr->as_u32 && pa->hi_addr.as_u32 == hi_addr->as_u32 && pa->fib_index == fib_index) { found_at_index = pa - am->proxy_arps; break; } } if (found_at_index != ~0) { /* Delete, otherwise it's already in the table */ if (is_del) vec_delete (am->proxy_arps, 1, found_at_index); return 0; } /* delete, no such entry */ if (is_del) return VNET_API_ERROR_NO_SUCH_ENTRY; /* add, not in table */ vec_add2 (am->proxy_arps, pa, 1); pa->lo_addr.as_u32 = lo_addr->as_u32; pa->hi_addr.as_u32 = hi_addr->as_u32; pa->fib_index = fib_index; return 0; } int arp_proxy_add (u32 fib_index, const ip4_address_t * lo, const ip4_address_t * hi) { return (vnet_proxy_arp_add_del (lo, hi, fib_index, 0)); } int arp_proxy_del (u32 fib_index, const ip4_address_t * lo, const ip4_address_t * hi) { return (vnet_proxy_arp_add_del (lo, hi, fib_index, 1)); } void proxy_arp_intfc_walk (proxy_arp_intf_walk_t cb, void *data) { arp_proxy_main_t *am = &arp_proxy_main; bool *enabled; vec_foreach (enabled, am->enabled_by_sw_if_index) { if (*enabled) cb (enabled - am->enabled_by_sw_if_index, data); } } static clib_error_t * set_int_proxy_arp_command_fn (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd) { vnet_main_t *vnm = vnet_get_main (); u32 sw_if_index; int enable = 0; sw_if_index = ~0; while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT) { if (unformat (input, "%U", unformat_vnet_sw_interface, vnm, &sw_if_index)) ; else if (unformat (input, "enable") || unformat (input, "on")) enable = 1; else if (unformat (input, "disable") || unformat (input, "off")) enable = 0; else break; } if (~0 == sw_if_index) return clib_error_return (0, "unknown input '%U'", format_unformat_error, input); if (enable) arp_proxy_enable (sw_if_index); else arp_proxy_disable (sw_if_index); return 0; } static clib_error_t * set_arp_proxy (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd) { ip4_address_t start = {.as_u32 = ~0 }, end = { .as_u32 = ~0}; u32 fib_index, table_id = 0; int add = 1; while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT) { if (unformat (input, "table-id %d", &table_id)) ; else if (unformat (input, "start %U", unformat_ip4_address, &start)) ; else if (unformat (input, "end %U", unformat_ip4_address, &end)) ; else if (unformat (input, "del") || unformat (input, "delete")) add = 0; else break; } fib_index = fib_table_find (FIB_PROTOCOL_IP4, table_id); if (~0 == fib_index) return (clib_error_return (0, "no such table: %d", table_id)); if (add) arp_proxy_add (fib_index, &start, &end); else arp_proxy_del (fib_index, &start, &end); return (NULL); } /* *INDENT-OFF* */ /*? * Enable proxy-arp on an interface. The vpp stack will answer ARP * requests for the indicated address range. Multiple proxy-arp * ranges may be provisioned. * * @note Proxy ARP as a technology is infamous for blackholing traffic. * Also, the underlying implementation has not been performance-tuned. * Avoid creating an unnecessarily large set of ranges. * * @cliexpar * To enable proxy arp on a range of addresses, use: * @cliexcmd{set ip arp proxy 6.0.0.1 - 6.0.0.11} * Append 'del' to delete a range of proxy ARP addresses: * @cliexcmd{set ip arp proxy 6.0.0.1 - 6.0.0.11 del} * You must then specifically enable proxy arp on individual interfaces: * @cliexcmd{set interface proxy-arp GigabitEthernet0/8/0 enable} * To disable proxy arp on an individual interface: * @cliexcmd{set interface proxy-arp GigabitEthernet0/8/0 disable} ?*/ VLIB_CLI_COMMAND (set_int_proxy_enable_command, static) = { .path = "set interface proxy-arp", .short_help = "set interface proxy-arp <intfc> [enable|disable]", .function = set_int_proxy_arp_command_fn, }; /* *INDENT-ON* */ /* *INDENT-OFF* */ VLIB_CLI_COMMAND (set_arp_proxy_command, static) = { .path = "set arp proxy", .short_help = "set arp proxy [del] table-ID <table-ID> start <start-address> end <end-addres>", .function = set_arp_proxy, }; /* *INDENT-ON* */ typedef struct { u8 packet_data[64]; } ethernet_arp_input_trace_t; static u8 * format_ethernet_arp_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 *); ethernet_arp_input_trace_t *t = va_arg (*va, ethernet_arp_input_trace_t *); s = format (s, "%U", format_ethernet_arp_header, t->packet_data, sizeof (t->packet_data)); return s; } static uword arp_proxy (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) { arp_proxy_main_t *am = &arp_proxy_main; vnet_main_t *vnm = vnet_get_main (); u32 n_left_from, next_index, *from, *to_next; u32 n_arp_replies_sent = 0; 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 (ethernet_arp_input_trace_t)); 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) { vlib_buffer_t *p0; ethernet_arp_header_t *arp0; ethernet_header_t *eth_rx; ip4_address_t proxy_src; u32 pi0, error0, next0, sw_if_index0, fib_index0; u8 is_request0; ethernet_proxy_arp_t *pa; pi0 = from[0]; to_next[0] = pi0; from += 1; to_next += 1; n_left_from -= 1; n_left_to_next -= 1; p0 = vlib_get_buffer (vm, pi0); arp0 = vlib_buffer_get_current (p0); /* Fill in ethernet header. */ eth_rx = ethernet_buffer_get_header (p0); is_request0 = arp0->opcode == clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_request); error0 = ETHERNET_ARP_ERROR_replies_sent; sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX]; next0 = ARP_REPLY_NEXT_DROP; fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0); if (~0 == fib_index0) { error0 = ETHERNET_ARP_ERROR_interface_no_table; } if (0 == error0 && is_request0) { u32 this_addr = clib_net_to_host_u32 (arp0->ip4_over_ethernet[1].ip4.as_u32); vec_foreach (pa, am->proxy_arps) { u32 lo_addr = clib_net_to_host_u32 (pa->lo_addr.as_u32); u32 hi_addr = clib_net_to_host_u32 (pa->hi_addr.as_u32); /* an ARP request hit in the proxy-arp table? */ if ((this_addr >= lo_addr && this_addr <= hi_addr) && (fib_index0 == pa->fib_index)) { proxy_src.as_u32 = arp0->ip4_over_ethernet[1].ip4.data_u32; /* * change the interface address to the proxied */ n_arp_replies_sent++; next0 = arp_mk_reply (vnm, p0, sw_if_index0, &proxy_src, arp0, eth_rx); } } } else { p0->error = node->errors[error0]; } 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); } vlib_error_count (vm, node->node_index, ETHERNET_ARP_ERROR_replies_sent, n_arp_replies_sent); return frame->n_vectors; } static char *ethernet_arp_error_strings[] = { #define _(sym,string) string, foreach_ethernet_arp_error #undef _ }; VLIB_REGISTER_NODE (arp_proxy_node, static) = { .function = arp_proxy,.name = "arp-proxy",.vector_size = sizeof (u32),.n_errors = ETHERNET_ARP_N_ERROR,.error_strings = ethernet_arp_error_strings,.n_next_nodes = ARP_REPLY_N_NEXT,.next_nodes = { [ARP_REPLY_NEXT_DROP] = "error-drop", [ARP_REPLY_NEXT_REPLY_TX] = "interface-output",} ,.format_buffer = format_ethernet_arp_header,.format_trace = format_ethernet_arp_input_trace,}; static clib_error_t * show_ip4_arp (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd) { arp_proxy_main_t *am = &arp_proxy_main; ethernet_proxy_arp_t *pa; if (vec_len (am->proxy_arps)) { vlib_cli_output (vm, "Proxy arps enabled for:"); vec_foreach (pa, am->proxy_arps) { vlib_cli_output (vm, "Fib_index %d %U - %U ", pa->fib_index, format_ip4_address, &pa->lo_addr, format_ip4_address, &pa->hi_addr); } } return (NULL); } /*? * Display all the IPv4 ARP proxy entries. * * @cliexpar * Example of how to display the IPv4 ARP table: * @cliexstart{show ip arp} * Time FIB IP4 Flags Ethernet Interface * 346.3028 0 6.1.1.3 de:ad:be:ef:ba:be GigabitEthernet2/0/0 * 3077.4271 0 6.1.1.4 S de:ad:be:ef:ff:ff GigabitEthernet2/0/0 * 2998.6409 1 6.2.2.3 de:ad:be:ef:00:01 GigabitEthernet2/0/0 * Proxy arps enabled for: * Fib_index 0 6.0.0.1 - 6.0.0.11 * @cliexend ?*/ /* *INDENT-OFF* */ VLIB_CLI_COMMAND (show_ip4_arp_command, static) = { .path = "show arp proxy", .function = show_ip4_arp, .short_help = "show ip arp", }; /* *INDENT-ON* */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */