/* * snat.c - simple nat plugin * * Copyright (c) 2016 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 #include #include #include #include #include #include snat_main_t snat_main; /* define message IDs */ #include /* define message structures */ #define vl_typedefs #include #undef vl_typedefs /* define generated endian-swappers */ #define vl_endianfun #include #undef vl_endianfun #define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__) /* Get the API version number */ #define vl_api_version(n,v) static u32 api_version=(v); #include #undef vl_api_version /* Macro to finish up custom dump fns */ #define FINISH \ vec_add1 (s, 0); \ vl_print (handle, (char *)s); \ vec_free (s); \ return handle; /* * A handy macro to set up a message reply. * Assumes that the following variables are available: * mp - pointer to request message * rmp - pointer to reply message type * rv - return value */ #define REPLY_MACRO(t) \ do { \ unix_shared_memory_queue_t * q = \ vl_api_client_index_to_input_queue (mp->client_index); \ if (!q) \ return; \ \ rmp = vl_msg_api_alloc (sizeof (*rmp)); \ rmp->_vl_msg_id = ntohs((t)+sm->msg_id_base); \ rmp->context = mp->context; \ rmp->retval = ntohl(rv); \ \ vl_msg_api_send_shmem (q, (u8 *)&rmp); \ } while(0); /* Hook up input features */ VNET_IP4_UNICAST_FEATURE_INIT (ip4_snat_in2out, static) = { .node_name = "snat-in2out", .runs_before = {"snat-out2in", 0}, .feature_index = &snat_main.rx_feature_in2out, }; VNET_IP4_UNICAST_FEATURE_INIT (ip4_snat_out2in, static) = { .node_name = "snat-out2in", .runs_before = {"ip4-lookup", 0}, .feature_index = &snat_main.rx_feature_out2in, }; /* * This routine exists to convince the vlib plugin framework that * we haven't accidentally copied a random .dll into the plugin directory. * * Also collects global variable pointers passed from the vpp engine */ clib_error_t * vlib_plugin_register (vlib_main_t * vm, vnet_plugin_handoff_t * h, int from_early_init) { snat_main_t * sm = &snat_main; clib_error_t * error = 0; sm->vlib_main = vm; sm->vnet_main = h->vnet_main; sm->ethernet_main = h->ethernet_main; return error; } /*$$$$$ move to an installed header file */ #if (1 || CLIB_DEBUG > 0) /* "trust, but verify" */ #define VALIDATE_SW_IF_INDEX(mp) \ do { u32 __sw_if_index = ntohl(mp->sw_if_index); \ vnet_main_t *__vnm = vnet_get_main(); \ if (pool_is_free_index(__vnm->interface_main.sw_interfaces, \ __sw_if_index)) { \ rv = VNET_API_ERROR_INVALID_SW_IF_INDEX; \ goto bad_sw_if_index; \ } \ } while(0); #define BAD_SW_IF_INDEX_LABEL \ do { \ bad_sw_if_index: \ ; \ } while (0); #define VALIDATE_RX_SW_IF_INDEX(mp) \ do { u32 __rx_sw_if_index = ntohl(mp->rx_sw_if_index); \ vnet_main_t *__vnm = vnet_get_main(); \ if (pool_is_free_index(__vnm->interface_main.sw_interfaces, \ __rx_sw_if_index)) { \ rv = VNET_API_ERROR_INVALID_SW_IF_INDEX; \ goto bad_rx_sw_if_index; \ } \ } while(0); #define BAD_RX_SW_IF_INDEX_LABEL \ do { \ bad_rx_sw_if_index: \ ; \ } while (0); #define VALIDATE_TX_SW_IF_INDEX(mp) \ do { u32 __tx_sw_if_index = ntohl(mp->tx_sw_if_index); \ vnet_main_t *__vnm = vnet_get_main(); \ if (pool_is_free_index(__vnm->interface_main.sw_interfaces, \ __tx_sw_if_index)) { \ rv = VNET_API_ERROR_INVALID_SW_IF_INDEX; \ goto bad_tx_sw_if_index; \ } \ } while(0); #define BAD_TX_SW_IF_INDEX_LABEL \ do { \ bad_tx_sw_if_index: \ ; \ } while (0); #else #define VALIDATE_SW_IF_INDEX(mp) #define BAD_SW_IF_INDEX_LABEL #define VALIDATE_RX_SW_IF_INDEX(mp) #define BAD_RX_SW_IF_INDEX_LABEL #define VALIDATE_TX_SW_IF_INDEX(mp) #define BAD_TX_SW_IF_INDEX_LABEL #endif /* CLIB_DEBUG > 0 */ void snat_add_address (snat_main_t *sm, ip4_address_t *addr) { snat_address_t * ap; vec_add2 (sm->addresses, ap, 1); ap->addr = *addr; } static void increment_v4_address (ip4_address_t * a) { u32 v; v = clib_net_to_host_u32(a->as_u32) + 1; a->as_u32 = clib_host_to_net_u32(v); } static void vl_api_snat_add_address_range_t_handler (vl_api_snat_add_address_range_t * mp) { snat_main_t * sm = &snat_main; vl_api_snat_add_address_range_reply_t * rmp; ip4_address_t this_addr; u32 start_host_order, end_host_order; int i, count; int rv = 0; u32 * tmp; if (mp->is_ip4 != 1) { rv = VNET_API_ERROR_UNIMPLEMENTED; goto send_reply; } tmp = (u32 *) mp->first_ip_address; start_host_order = clib_host_to_net_u32 (tmp[0]); tmp = (u32 *) mp->last_ip_address; end_host_order = clib_host_to_net_u32 (tmp[0]); count = (end_host_order - start_host_order) + 1; if (count > 1024) clib_warning ("%U - %U, %d addresses...", format_ip4_address, mp->first_ip_address, format_ip4_address, mp->last_ip_address, count); memcpy (&this_addr.as_u8, mp->first_ip_address, 4); for (i = 0; i < count; i++) { snat_add_address (sm, &this_addr); increment_v4_address (&this_addr); } send_reply: REPLY_MACRO (VL_API_SNAT_ADD_ADDRESS_RANGE_REPLY); } static void *vl_api_snat_add_address_range_t_print (vl_api_snat_add_address_range_t *mp, void * handle) { u8 * s; s = format (0, "SCRIPT: snat_add_address_range "); s = format (s, "%U ", format_ip4_address, mp->first_ip_address); if (memcmp (mp->first_ip_address, mp->last_ip_address, 4)) { s = format (s, " - %U ", format_ip4_address, mp->last_ip_address); } FINISH; } static void vl_api_snat_interface_add_del_feature_t_handler (vl_api_snat_interface_add_del_feature_t * mp) { snat_main_t * sm = &snat_main; vl_api_snat_interface_add_del_feature_reply_t * rmp; u8 is_del = mp->is_add == 0; u32 sw_if_index = ntohl(mp->sw_if_index); u32 ci; ip4_main_t * im = &ip4_main; ip_lookup_main_t * lm = &im->lookup_main; ip_config_main_t * rx_cm = &lm->rx_config_mains[VNET_UNICAST]; u32 feature_index; int rv = 0; VALIDATE_SW_IF_INDEX(mp); feature_index = mp->is_inside ? sm->rx_feature_in2out : sm->rx_feature_out2in; ci = rx_cm->config_index_by_sw_if_index[sw_if_index]; ci = (is_del ? vnet_config_del_feature : vnet_config_add_feature) (sm->vlib_main, &rx_cm->config_main, ci, feature_index, 0 /* config struct */, 0 /* sizeof config struct*/); rx_cm->config_index_by_sw_if_index[sw_if_index] = ci; BAD_SW_IF_INDEX_LABEL; REPLY_MACRO(VL_API_SNAT_INTERFACE_ADD_DEL_FEATURE_REPLY); } static void *vl_api_snat_interface_add_del_feature_t_print (vl_api_snat_interface_add_del_feature_t * mp, void *handle) { u8 * s; s = format (0, "SCRIPT: snat_interface_add_del_feature "); s = format (s, "sw_if_index %d %s %s", clib_host_to_net_u32(mp->sw_if_index), mp->is_inside ? "in":"out", mp->is_add ? "" : "del"); FINISH; } /* List of message types that this plugin understands */ #define foreach_snat_plugin_api_msg \ _(SNAT_ADD_ADDRESS_RANGE, snat_add_address_range) \ _(SNAT_INTERFACE_ADD_DEL_FEATURE, snat_interface_add_del_feature) /* Set up the API message handling tables */ static clib_error_t * snat_plugin_api_hookup (vlib_main_t *vm) { snat_main_t * sm __attribute__ ((unused)) = &snat_main; #define _(N,n) \ vl_msg_api_set_handlers((VL_API_##N + sm->msg_id_base), \ #n, \ vl_api_##n##_t_handler, \ vl_noop_handler, \ vl_api_##n##_t_endian, \ vl_api_##n##_t_print, \ sizeof(vl_api_##n##_t), 1); foreach_snat_plugin_api_msg; #undef _ return 0; } static void plugin_custom_dump_configure (snat_main_t * sm) { #define _(n,f) sm->api_main->msg_print_handlers \ [VL_API_##n + sm->msg_id_base] \ = (void *) vl_api_##f##_t_print; foreach_snat_plugin_api_msg; #undef _ } static clib_error_t * snat_init (vlib_main_t * vm) { snat_main_t * sm = &snat_main; clib_error_t * error = 0; ip4_main_t * im = &ip4_main; ip_lookup_main_t * lm = &im->lookup_main; u8 * name; name = format (0, "snat_%08x%c", api_version, 0); /* Ask for a correctly-sized block of API message decode slots */ sm->msg_id_base = vl_msg_api_get_msg_ids ((char *) name, VL_MSG_FIRST_AVAILABLE); sm->vlib_main = vm; sm->vnet_main = vnet_get_main(); sm->ip4_main = im; sm->ip4_lookup_main = lm; sm->api_main = &api_main; error = snat_plugin_api_hookup (vm); plugin_custom_dump_configure (sm); vec_free(name); return error; } VLIB_INIT_FUNCTION (snat_init); void snat_free_outside_address_and_port (snat_main_t * sm, snat_session_key_t * k, u32 address_index) { snat_address_t *a; u16 port_host_byte_order = clib_net_to_host_u16 (k->port); ASSERT (address_index < vec_len (sm->addresses)); a = sm->addresses + address_index; ASSERT (clib_bitmap_get (a->busy_port_bitmap, port_host_byte_order) == 1); a->busy_port_bitmap = clib_bitmap_set (a->busy_port_bitmap, port_host_byte_order, 0); a->busy_ports--; } int snat_alloc_outside_address_and_port (snat_main_t * sm, snat_session_key_t * k, u32 * address_indexp) { int i; snat_address_t *a; u32 portnum; for (i = 0; i < vec_len (sm->addresses); i++) { if (sm->addresses[i].busy_ports < (65535-1024)) { a = sm->addresses + i; while (1) { portnum = random_u32 (&sm->random_seed); portnum &= 0xFFFF; if (portnum < 1024) continue; if (clib_bitmap_get (a->busy_port_bitmap, portnum)) continue; a->busy_port_bitmap = clib_bitmap_set (a->busy_port_bitmap, portnum, 1); a->busy_ports++; /* Caller sets protocol and fib index */ k->addr = a->addr; k->port = clib_host_to_net_u16(portnum); *address_indexp = i; return 0; } } } /* Totally out of translations to use... */ return 1; } static clib_error_t * add_address_command_fn (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd) { snat_main_t * sm = &snat_main; ip4_address_t start_addr, end_addr, this_addr; u32 start_host_order, end_host_order; int i, count; if (unformat (input, "%U - %U", unformat_ip4_address, &start_addr, unformat_ip4_address, &end_addr)) ; else if (unformat (input, "%U", unformat_ip4_address, &start_addr)) end_addr = start_addr; start_host_order = clib_host_to_net_u32 (start_addr.as_u32); end_host_order = clib_host_to_net_u32 (end_addr.as_u32); if (end_host_order < start_host_order) return clib_error_return (0, "end address less than start address"); count = (end_host_order - start_host_order) + 1; if (count > 1024) clib_warning ("%U - %U, %d addresses...", format_ip4_address, &start_addr, format_ip4_address, &end_addr, count); this_addr = start_addr; for (i = 0; i < count; i++) { snat_add_address (sm, &this_addr); increment_v4_address (&this_addr); } return 0; } VLIB_CLI_COMMAND (add_address_command, static) = { .path = "snat add address", .short_help = "snat add addresses [- ]", .function = add_address_command_fn, }; static clib_error_t * snat_feature_command_fn (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd) { vnet_main_t * vnm = vnet_get_main(); snat_main_t * sm = &snat_main; ip4_main_t * im = &ip4_main; ip_lookup_main_t * lm = &im->lookup_main; ip_config_main_t * rx_cm = &lm->rx_config_mains[VNET_UNICAST]; clib_error_t * error = 0; u32 sw_if_index, ci; u32 feature_index; u32 * inside_sw_if_indices = 0; u32 * outside_sw_if_indices = 0; int is_del = 0; int i; sw_if_index = ~0; while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT) { if (unformat (input, "in %U", unformat_vnet_sw_interface, vnm, &sw_if_index)) vec_add1 (inside_sw_if_indices, sw_if_index); else if (unformat (input, "out %U", unformat_vnet_sw_interface, vnm, &sw_if_index)) vec_add1 (outside_sw_if_indices, sw_if_index); else if (unformat (input, "del")) is_del = 1; else break; } if (vec_len (inside_sw_if_indices)) { feature_index = sm->rx_feature_in2out; for (i = 0; i < vec_len(inside_sw_if_indices); i++) { sw_if_index = inside_sw_if_indices[i]; ci = rx_cm->config_index_by_sw_if_index[sw_if_index]; ci = (is_del ? vnet_config_del_feature : vnet_config_add_feature) (vm, &rx_cm->config_main, ci, feature_index, 0 /* config struct */, 0 /* sizeof config struct*/); rx_cm->config_index_by_sw_if_index[sw_if_index] = ci; } } if (vec_len (outside_sw_if_indices)) { feature_index = sm->rx_feature_out2in; for (i = 0; i < vec_len(outside_sw_if_indices); i++) { sw_if_index = outside_sw_if_indices[i]; ci = rx_cm->config_index_by_sw_if_index[sw_if_index]; ci = (is_del ? vnet_config_del_feature : vnet_config_add_feature) (vm, &rx_cm->config_main, ci, feature_index, 0 /* config struct */, 0 /* sizeof config struct*/); rx_cm->config_index_by_sw_if_index[sw_if_index] = ci; } } vec_free (inside_sw_if_indices); vec_free (outside_sw_if_indices); return error; } VLIB_CLI_COMMAND (set_interface_snat_command, static) = { .path = "set interface snat", .function = snat_feature_command_fn, .short_help = "set interface snat in out [del]", }; static clib_error_t * snat_config (vlib_main_t * vm, unformat_input_t * input) { snat_main_t * sm = &snat_main; u32 translation_buckets = 1024; u32 translation_memory_size = 128<<20; u32 user_buckets = 128; u32 user_memory_size = 64<<20; u32 max_translations_per_user = 100; u32 outside_vrf_id = 0; while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT) { if (unformat (input, "translation hash buckets %d", &translation_buckets)) ; else if (unformat (input, "translation hash memory %d", &translation_memory_size)); else if (unformat (input, "user hash buckets %d", &user_buckets)) ; else if (unformat (input, "user hash memory %d", &user_memory_size)) ; else if (unformat (input, "max translations per user %d", &max_translations_per_user)) ; else if (unformat (input, "outside VRF id %d", &outside_vrf_id)) ; else return clib_error_return (0, "unknown input `%U'", format_unformat_error, input); } /* for show commands, etc. */ sm->translation_buckets = translation_buckets; sm->translation_memory_size = translation_memory_size; sm->user_buckets = user_buckets; sm->user_memory_size = user_memory_size; sm->max_translations_per_user = max_translations_per_user; sm->outside_vrf_id = outside_vrf_id; clib_bihash_init_8_8 (&sm->in2out, "in2out", translation_buckets, translation_memory_size); clib_bihash_init_8_8 (&sm->out2in, "out2in", translation_buckets, translation_memory_size); clib_bihash_init_8_8 (&sm->user_hash, "users", user_buckets, user_memory_size); return 0; } VLIB_CONFIG_FUNCTION (snat_config, "snat"); u8 * format_snat_key (u8 * s, va_list * args) { snat_session_key_t * key = va_arg (*args, snat_session_key_t *); char * protocol_string = "unknown"; static char *protocol_strings[] = { "UDP", "TCP", "ICMP", }; if (key->protocol < ARRAY_LEN(protocol_strings)) protocol_string = protocol_strings[key->protocol]; s = format (s, "%U proto %s port %d fib %d", format_ip4_address, &key->addr, protocol_string, key->port, key->fib_index); return s; } u8 * format_snat_session (u8 * s, va_list * args) { snat_main_t * sm __attribute__((unused)) = va_arg (*args, snat_main_t *); snat_session_t * sess = va_arg (*args, snat_session_t *); s = format (s, " i2o %U\n", format_snat_key, &sess->in2out); s = format (s, " o2i %U\n", format_snat_key, &sess->out2in); s = format (s, " last heard %.2f\n", sess->last_heard); s = format (s, " total pkts %d, total bytes %lld\n", sess->total_pkts, sess->total_bytes); return s; } u8 * format_snat_user (u8 * s, va_list * args) { snat_main_t * sm = va_arg (*args, snat_main_t *); snat_user_t * u = va_arg (*args, snat_user_t *); int verbose = va_arg (*args, int); dlist_elt_t * head, * elt; u32 elt_index, head_index; u32 session_index; snat_session_t * sess; s = format (s, "%U: %d translations\n", format_ip4_address, &u->addr, u->nsessions); if (verbose == 0) return s; head_index = u->sessions_per_user_list_head_index; head = pool_elt_at_index (sm->list_pool, head_index); elt_index = head->next; elt = pool_elt_at_index (sm->list_pool, elt_index); session_index = elt->value; while (session_index != ~0) { sess = pool_elt_at_index (sm->sessions, session_index); s = format (s, " %U\n", format_snat_session, sm, sess); elt_index = elt->next; elt = pool_elt_at_index (sm->list_pool, elt_index); session_index = elt->value; } return s; } static clib_error_t * show_snat_command_fn (vlib_main_t * vm, unformat_input_t * input, vlib_cli_command_t * cmd) { int verbose = 0; snat_main_t * sm = &snat_main; snat_user_t * u; if (unformat (input, "detail")) verbose = 1; else if (unformat (input, "verbose")) verbose = 2; vlib_cli_output (vm, "%d users, %d outside addresses, %d active sessions", pool_elts (sm->users), vec_len (sm->addresses), pool_elts (sm->sessions)); if (verbose > 0) { vlib_cli_output (vm, "%U", format_bihash_8_8, &sm->in2out, verbose - 1); vlib_cli_output (vm, "%U", format_bihash_8_8, &sm->out2in, verbose - 1); vlib_cli_output (vm, "%d list pool elements", pool_elts (sm->list_pool)); pool_foreach (u, sm->users, ({ vlib_cli_output (vm, "%U", format_snat_user, sm, u, verbose - 1); })); } return 0; } VLIB_CLI_COMMAND (show_snat_command, static) = { .path = "show snat", .short_help = "show snat", .function = show_snat_command_fn, };