From 6545716c073c88ad86458620c6dbc59ba1cd00bb Mon Sep 17 00:00:00 2001 From: Dave Barach Date: Tue, 10 Oct 2017 17:53:14 -0400 Subject: VPP-1027: DNS name resolver This patch is a plausible first-cut, suitable for initial testing by vcl (host stack client library). Main features; - recursive name resolution - multiple ip4/ip6 name servers - cache size limit enforcement - currently limited to 65K - ttl / aging - static mapping support - show / clear / debug CLI commands Binary APIs provided for the following: - add/delete name servers - enable/disable the name cache - resolve a name To Do list: - Respond to ip4/ip6 client DNS requests (vs. binary API requests) - Perf / scale tuning - map pending transaction ids to pool indices, so the cache can (greatly) exceed 65K entries - Security improvements - Use unpredictable dns transaction IDs, related to previous item - Make sure that response-packet src ip addresses match the server - Add binary APIs - deliver raw response data to clients - control recursive name resolution - Documentation Change-Id: I48c373d5c05d7108ccd814d4055caf8c75ca10b7 Signed-off-by: Dave Barach --- src/vnet/dns/dns.api | 66 ++ src/vnet/dns/dns.c | 2114 +++++++++++++++++++++++++++++++++++++++ src/vnet/dns/dns.h | 149 +++ src/vnet/dns/dns_packet.h | 154 +++ src/vnet/dns/reply_node.c | 214 ++++ src/vnet/dns/resolver_process.c | 243 +++++ 6 files changed, 2940 insertions(+) create mode 100644 src/vnet/dns/dns.api create mode 100644 src/vnet/dns/dns.c create mode 100644 src/vnet/dns/dns.h create mode 100644 src/vnet/dns/dns_packet.h create mode 100644 src/vnet/dns/reply_node.c create mode 100644 src/vnet/dns/resolver_process.c (limited to 'src/vnet/dns') diff --git a/src/vnet/dns/dns.api b/src/vnet/dns/dns.api new file mode 100644 index 00000000000..55574458ddd --- /dev/null +++ b/src/vnet/dns/dns.api @@ -0,0 +1,66 @@ +/* + * Copyright (c) 2017 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. + */ + +vl_api_version 1.0.0 + +/** \brief enable/disable name resolution + + @param client_index - opaque cookie to identify the sender + @param context - sender context, to match reply w/ request + @param is_enable - 1 = enable, 0 = disable +*/ +autoreply define dns_enable_disable { + u32 client_index; + u32 context; + u8 enable; +}; + +/** \brief add or delete an upstream name server + + @param client_index - opaque cookie to identify the sender + @param context - sender context, to match reply w/ request + @param is_ip6 - an ip6 name server + @param is_add - add = 1, delete = 0 + @param server_address - server ip address +*/ +autoreply define dns_name_server_add_del { + u32 client_index; + u32 context; + u8 is_ip6; + u8 is_add; + u8 server_address[16]; +}; + +/** \brief DNS name resolution request + + @param client_index - opaque cookie to identify the sender + @param context - sender context, to match reply w/ request + @param name - the name to resolve +*/ +define dns_resolve_name { + u32 client_index; + u32 context; + u8 name[128]; + }; + +define dns_resolve_name_reply { + u32 context; + i32 retval; + u8 ip4_set; + u8 ip6_set; + u8 ip4_address[4]; + u8 ip6_address[16]; +}; + diff --git a/src/vnet/dns/dns.c b/src/vnet/dns/dns.c new file mode 100644 index 00000000000..90079e17e99 --- /dev/null +++ b/src/vnet/dns/dns.c @@ -0,0 +1,2114 @@ +/* + * Copyright (c) 2017 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 + +#define vl_typedefs /* define message structures */ +#include +#undef vl_typedefs + +#define vl_endianfun /* define message structures */ +#include +#undef vl_endianfun + +/* instantiate all the print functions we know about */ +#define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__) +#define vl_printfun +#include +#undef vl_printfun + +#include + +dns_main_t dns_main; + +static int +dns_cache_clear (dns_main_t * dm) +{ + dns_cache_entry_t *ep; + + if (dm->is_enabled == 0) + return VNET_API_ERROR_NAME_RESOLUTION_NOT_ENABLED; + + dns_cache_lock (dm); + + /* *INDENT-OFF* */ + pool_foreach (ep, dm->entries, + ({ + vec_free (ep->name); + vec_free (ep->api_clients_to_notify); + vec_free (ep->api_client_contexts); + vec_free (ep->ip4_peers_to_notify); + vec_free (ep->ip6_peers_to_notify); + })); + /* *INDENT-ON* */ + + pool_free (dm->entries); + hash_free (dm->cache_entry_by_name); + dm->cache_entry_by_name = hash_create_string (0, sizeof (uword)); + vec_free (dm->unresolved_entries); + dns_cache_unlock (dm); + return 0; +} + +static int +dns_enable_disable (dns_main_t * dm, int is_enable) +{ + vlib_thread_main_t *tm = &vlib_thread_main; + u32 n_vlib_mains = tm->n_vlib_mains; + + if (is_enable) + { + if (vec_len (dm->ip4_name_servers) == 0 + && (vec_len (dm->ip6_name_servers) == 0)) + return VNET_API_ERROR_NO_NAME_SERVERS; + + if (dm->cache_entry_by_name == 0) + { + if (n_vlib_mains > 1) + dm->cache_lock = clib_mem_alloc_aligned (CLIB_CACHE_LINE_BYTES, + CLIB_CACHE_LINE_BYTES); + + dm->cache_entry_by_name = hash_create_string (0, sizeof (uword)); + } + + dm->is_enabled = 1; + } + else + { + dns_cache_clear (dm); + dm->is_enabled = 0; + } + return 0; +} + +static void vl_api_dns_enable_disable_t_handler + (vl_api_dns_enable_disable_t * mp) +{ + vl_api_dns_enable_disable_reply_t *rmp; + dns_main_t *dm = &dns_main; + int rv; + + rv = dns_enable_disable (dm, mp->enable); + + REPLY_MACRO (VL_API_DNS_ENABLE_DISABLE_REPLY); +} + +static int +dns6_name_server_add_del (dns_main_t * dm, + u8 * server_address_as_u8, int is_add) +{ + int i; + ip6_address_t *ap; + + if (is_add) + { + /* Already there? done... */ + for (i = 0; i < vec_len (dm->ip6_name_servers); i++) + { + if (!memcmp (dm->ip6_name_servers + i, server_address_as_u8, + sizeof (ip6_address_t))) + return 0; + } + + vec_add2 (dm->ip6_name_servers, ap, 1); + clib_memcpy (ap, server_address_as_u8, sizeof (*ap)); + } + else + { + for (i = 0; i < vec_len (dm->ip6_name_servers); i++) + { + if (!memcmp (dm->ip6_name_servers + i, server_address_as_u8, + sizeof (ip6_address_t))) + { + vec_delete (dm->ip6_name_servers, 1, i); + return 0; + } + } + return VNET_API_ERROR_NAME_SERVER_NOT_FOUND; + } + return 0; +} + +static int +dns4_name_server_add_del (dns_main_t * dm, + u8 * server_address_as_u8, int is_add) +{ + int i; + ip4_address_t *ap; + + if (is_add) + { + /* Already there? done... */ + for (i = 0; i < vec_len (dm->ip4_name_servers); i++) + { + if (!memcmp (dm->ip4_name_servers + i, server_address_as_u8, + sizeof (ip4_address_t))) + return 0; + } + + vec_add2 (dm->ip4_name_servers, ap, 1); + clib_memcpy (ap, server_address_as_u8, sizeof (*ap)); + } + else + { + for (i = 0; i < vec_len (dm->ip4_name_servers); i++) + { + if (!memcmp (dm->ip4_name_servers + i, server_address_as_u8, + sizeof (ip4_address_t))) + { + vec_delete (dm->ip4_name_servers, 1, i); + return 0; + } + } + return VNET_API_ERROR_NAME_SERVER_NOT_FOUND; + } + return 0; +} + +static void vl_api_dns_name_server_add_del_t_handler + (vl_api_dns_name_server_add_del_t * mp) +{ + dns_main_t *dm = &dns_main; + vl_api_dns_name_server_add_del_reply_t *rmp; + int rv; + + if (mp->is_ip6) + rv = dns6_name_server_add_del (dm, mp->server_address, mp->is_add); + else + rv = dns4_name_server_add_del (dm, mp->server_address, mp->is_add); + + REPLY_MACRO (VL_API_DNS_NAME_SERVER_ADD_DEL_REPLY); +} + +static void +send_dns4_request (dns_main_t * dm, + dns_cache_entry_t * ep, ip4_address_t * server) +{ + vlib_main_t *vm = dm->vlib_main; + f64 now = vlib_time_now (vm); + u32 bi; + vlib_buffer_t *b; + ip4_header_t *ip; + fib_prefix_t prefix; + fib_node_index_t fei; + u32 sw_if_index, fib_index; + udp_header_t *udp; + ip4_main_t *im4 = &ip4_main; + ip_lookup_main_t *lm4 = &im4->lookup_main; + ip_interface_address_t *ia = 0; + ip4_address_t *src_address; + u8 *dns_request; + vlib_frame_t *f; + u32 *to_next; + + ASSERT (ep->dns_request); + + /* Find a FIB path to the server */ + clib_memcpy (&prefix.fp_addr.ip4, server, sizeof (*server)); + prefix.fp_proto = FIB_PROTOCOL_IP4; + prefix.fp_len = 32; + + fib_index = fib_table_find (prefix.fp_proto, 0 /* default VRF for now */ ); + if (fib_index == (u32) ~ 0) + { + clib_warning ("no fib table"); + return; + } + + fei = fib_table_lookup (fib_index, &prefix); + + /* Couldn't find route to destination. Bail out. */ + if (fei == FIB_NODE_INDEX_INVALID) + { + clib_warning ("no route to DNS server"); + return; + } + + sw_if_index = fib_entry_get_resolving_interface (fei); + + if (sw_if_index == ~0) + { + clib_warning + ("route to %U exists, fei %d, get_resolving_interface returned" + " ~0", fei, format_ip4_address, &prefix.fp_addr); + return; + } + + /* *INDENT-OFF* */ + foreach_ip_interface_address(lm4, ia, sw_if_index, 1 /* honor unnummbered */, + ({ + src_address = ip_interface_address_get_address (lm4, ia); + goto found_src_address; + })); + /* *INDENT-ON* */ + + clib_warning ("FIB BUG"); + return; + +found_src_address: + + /* Go get a buffer */ + if (vlib_buffer_alloc (dm->vlib_main, &bi, 1) != 1) + return; + + b = vlib_get_buffer (vm, bi); + b->current_length = sizeof (ip4_header_t) + sizeof (udp_header_t) + + vec_len (ep->dns_request); + b->total_length_not_including_first_buffer = 0; + b->flags = + VLIB_BUFFER_TOTAL_LENGTH_VALID | VNET_BUFFER_F_LOCALLY_ORIGINATED; + vnet_buffer (b)->sw_if_index[VLIB_RX] = 0; /* "local0" */ + vnet_buffer (b)->sw_if_index[VLIB_TX] = 0; /* default VRF for now */ + + ip = vlib_buffer_get_current (b); + memset (ip, 0, sizeof (*ip)); + udp = (udp_header_t *) (ip + 1); + memset (udp, 0, sizeof (*udp)); + + dns_request = (u8 *) (udp + 1); + + /* IP header */ + ip->ip_version_and_header_length = 0x45; + ip->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b)); + ip->ttl = 255; + ip->protocol = IP_PROTOCOL_UDP; + ip->src_address.as_u32 = src_address->as_u32; + ip->dst_address.as_u32 = server->as_u32; + ip->checksum = ip4_header_checksum (ip); + + /* UDP header */ + udp->src_port = clib_host_to_net_u16 (UDP_DST_PORT_dns_reply); + udp->dst_port = clib_host_to_net_u16 (UDP_DST_PORT_dns); + udp->length = clib_host_to_net_u16 (sizeof (udp_header_t) + + vec_len (ep->dns_request)); + udp->checksum = 0; + + /* The actual DNS request */ + clib_memcpy (dns_request, ep->dns_request, vec_len (ep->dns_request)); + + /* Ship it to ip4_lookup */ + f = vlib_get_frame_to_node (vm, ip4_lookup_node.index); + to_next = vlib_frame_vector_args (f); + to_next[0] = bi; + f->n_vectors = 1; + vlib_put_frame_to_node (vm, ip4_lookup_node.index, f); + + ep->retry_timer = now + 2.0; +} + +static void +send_dns6_request (dns_main_t * dm, + dns_cache_entry_t * ep, ip6_address_t * server) +{ + vlib_main_t *vm = dm->vlib_main; + f64 now = vlib_time_now (vm); + u32 bi; + vlib_buffer_t *b; + ip6_header_t *ip; + fib_prefix_t prefix; + fib_node_index_t fei; + u32 sw_if_index, fib_index; + udp_header_t *udp; + ip6_main_t *im6 = &ip6_main; + ip_lookup_main_t *lm6 = &im6->lookup_main; + ip_interface_address_t *ia = 0; + ip6_address_t *src_address; + u8 *dns_request; + vlib_frame_t *f; + u32 *to_next; + int junk __attribute__ ((unused)); + + ASSERT (ep->dns_request); + + /* Find a FIB path to the server */ + clib_memcpy (&prefix.fp_addr, server, sizeof (*server)); + prefix.fp_proto = FIB_PROTOCOL_IP6; + prefix.fp_len = 32; + + fib_index = fib_table_find (prefix.fp_proto, 0 /* default VRF for now */ ); + if (fib_index == (u32) ~ 0) + { + clib_warning ("no fib table"); + return; + } + + fei = fib_table_lookup (fib_index, &prefix); + + /* Couldn't find route to destination. Bail out. */ + if (fei == FIB_NODE_INDEX_INVALID) + { + clib_warning ("no route to DNS server"); + } + + sw_if_index = fib_entry_get_resolving_interface (fei); + + /* *INDENT-OFF* */ + foreach_ip_interface_address(lm6, ia, sw_if_index, 1 /* honor unnummbered */, + ({ + src_address = ip_interface_address_get_address (lm6, ia); + goto found_src_address; + })); + /* *INDENT-ON* */ + + clib_warning ("FIB BUG"); + return; + +found_src_address: + + /* Go get a buffer */ + if (vlib_buffer_alloc (dm->vlib_main, &bi, 1) != 1) + return; + + b = vlib_get_buffer (vm, bi); + b->current_length = sizeof (ip6_header_t) + sizeof (udp_header_t) + + vec_len (ep->dns_request); + b->total_length_not_including_first_buffer = 0; + b->flags = + VLIB_BUFFER_TOTAL_LENGTH_VALID | VNET_BUFFER_F_LOCALLY_ORIGINATED; + + ip = vlib_buffer_get_current (b); + memset (ip, 0, sizeof (*ip)); + udp = (udp_header_t *) (ip + 1); + memset (udp, 0, sizeof (*udp)); + + dns_request = (u8 *) (udp + 1); + + /* IP header */ + ip->ip_version_traffic_class_and_flow_label = + clib_host_to_net_u32 (0x6 << 28); + + ip->payload_length = + clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b) + - sizeof (ip6_header_t)); + ip->hop_limit = 255; + ip->protocol = IP_PROTOCOL_UDP; + clib_memcpy (&ip->src_address, src_address, sizeof (ip6_address_t)); + clib_memcpy (&ip->dst_address, server, sizeof (ip6_address_t)); + + /* UDP header */ + udp->src_port = clib_host_to_net_u16 (UDP_DST_PORT_dns_reply); + udp->dst_port = clib_host_to_net_u16 (UDP_DST_PORT_dns); + udp->length = clib_host_to_net_u16 (sizeof (udp_header_t) + + vec_len (ep->dns_request)); + udp->checksum = 0; + udp->checksum = ip6_tcp_udp_icmp_compute_checksum (vm, b, ip, &junk); + + /* The actual DNS request */ + clib_memcpy (dns_request, ep->dns_request, vec_len (ep->dns_request)); + + /* Ship it to ip6_lookup */ + f = vlib_get_frame_to_node (vm, ip6_lookup_node.index); + to_next = vlib_frame_vector_args (f); + to_next[0] = bi; + f->n_vectors = 1; + + ep->retry_timer = now + 2.0; +} + +/** + * Translate "foo.com" into "0x3 f o o 0x3 c o m 0x0" + * A historical / hysterical micro-TLV scheme. DGMS. + */ +u8 * +name_to_labels (u8 * name) +{ + int i; + int last_label_index; + u8 *rv; + + rv = vec_dup (name); + + /* punch in space for the first length */ + vec_insert (rv, 1, 0); + last_label_index = 0; + i = 1; + + while (i < vec_len (rv)) + { + if (rv[i] == '.') + { + rv[last_label_index] = (i - last_label_index) - 1; + if ((i - last_label_index) > 63) + clib_warning ("stupid name, label length %d", + i - last_label_index); + last_label_index = i; + rv[i] = 0; + } + i++; + } + /* Set the last real label length */ + rv[last_label_index] = (i - last_label_index) - 1; + + /* + * Add a [sic] NULL root label. Otherwise, the name parser can't figure out + * where to stop. + */ + vec_add1 (rv, 0); + return rv; +} + +/** + * arc-function for the above. + * Translate "0x3 f o o 0x3 c o m 0x0" into "foo.com" + * Produces a non-NULL-terminated u8 *vector. %v format is your friend. + */ +u8 * +labels_to_name (u8 * label, u8 * full_text, u8 ** parse_from_here) +{ + u8 *reply = 0; + u16 offset; + u8 len; + int i; + + *parse_from_here = 0; + + /* chase initial pointer? */ + if ((label[0] & 0xC0) == 0xC0) + { + *parse_from_here = label + 2; + offset = ((label[0] & 0x3f) << 8) + label[1]; + label = full_text + offset; + } + + len = *label++; + + while (len) + { + for (i = 0; i < len; i++) + vec_add1 (reply, *label++); + + /* chase pointer? */ + if ((label[0] & 0xC0) == 0xC0) + { + *parse_from_here = label + 2; + offset = ((label[0] & 0x3f) << 8) + label[1]; + label = full_text + offset; + } + + len = *label++; + if (len) + vec_add1 (reply, '.'); + } + if (*parse_from_here == 0) + *parse_from_here = label; + return reply; +} + +void +vnet_send_dns_request (dns_main_t * dm, dns_cache_entry_t * ep) +{ + dns_header_t *h; + dns_query_t *qp; + u16 tmp; + u8 *request; + u32 qp_offset; + + /* Construct the dns request, if we haven't been here already */ + if (vec_len (ep->dns_request) == 0) + { + /* + * Start with the variadic portion of the exercise. + * Turn the name into a set of DNS "labels". Max length + * per label is 63, enforce that. + */ + request = name_to_labels (ep->name); + qp_offset = vec_len (request); + + /* Add space for the query header */ + vec_validate (request, qp_offset + sizeof (dns_query_t) - 1); + + qp = (dns_query_t *) (request + qp_offset); + + qp->type = clib_host_to_net_u16 (DNS_TYPE_ALL); + qp->class = clib_host_to_net_u16 (DNS_CLASS_IN); + + /* Punch in space for the dns_header_t */ + vec_insert (request, sizeof (dns_header_t), 0); + + h = (dns_header_t *) request; + + /* Transaction ID = pool index */ + h->id = clib_host_to_net_u16 (ep - dm->entries); + + /* Ask for a recursive lookup */ + tmp = DNS_RD | DNS_OPCODE_QUERY; + h->flags = clib_host_to_net_u16 (tmp); + h->qdcount = clib_host_to_net_u16 (1); + h->nscount = 0; + h->arcount = 0; + + ep->dns_request = request; + } + + /* Work out which server / address family we're going to use */ + + /* Retry using current server */ + if (ep->retry_count++ < DNS_RETRIES_PER_SERVER) + { + if (ep->server_af == 1 /* ip6 */ ) + { + if (vec_len (dm->ip6_name_servers)) + { + send_dns6_request (dm, ep, + dm->ip6_name_servers + ep->server_rotor); + goto out; + } + else + ep->server_af = 0; + } + if (vec_len (dm->ip4_name_servers)) + { + send_dns4_request (dm, ep, dm->ip4_name_servers + ep->server_rotor); + goto out; + } + } + else /* switch to a new server */ + { + ep->retry_count = 1; + ep->server_rotor++; + if (ep->server_af == 1 /* ip6 */ ) + { + if (ep->server_rotor >= vec_len (dm->ip6_name_servers)) + { + ep->server_rotor = 0; + ep->server_af = vec_len (dm->ip4_name_servers) > 0 ? 0 : 1; + } + } + else + { + if (ep->server_rotor >= vec_len (dm->ip4_name_servers)) + { + ep->server_rotor = 0; + ep->server_af = vec_len (dm->ip6_name_servers) > 0 ? 1 : 0; + } + } + } + + if (ep->server_af == 1 /* ip6 */ ) + send_dns6_request (dm, ep, dm->ip6_name_servers + ep->server_rotor); + else + send_dns4_request (dm, ep, dm->ip4_name_servers + ep->server_rotor); + +out: + + vlib_process_signal_event_mt (dm->vlib_main, dns_resolver_node.index, + DNS_RESOLVER_EVENT_PENDING, 0); +} + +int +vnet_dns_delete_entry_by_index_nolock (dns_main_t * dm, u32 index) +{ + dns_cache_entry_t *ep; + int i; + + if (dm->is_enabled == 0) + return VNET_API_ERROR_NAME_RESOLUTION_NOT_ENABLED; + + if (pool_is_free_index (dm->entries, index)) + return VNET_API_ERROR_NO_SUCH_ENTRY; + + ep = pool_elt_at_index (dm->entries, index); + + if (!(ep->flags & DNS_CACHE_ENTRY_FLAG_VALID)) + { + for (i = 0; i < vec_len (dm->unresolved_entries); i++) + if (index == dm->unresolved_entries[i]) + { + vec_delete (dm->unresolved_entries, 1, i); + goto found; + } + clib_warning ("pool elt %d supposedly pending, but not found...", + index); + } + +found: + hash_unset_mem (dm->cache_entry_by_name, ep->name); + vec_free (ep->name); + vec_free (ep->api_clients_to_notify); + vec_free (ep->api_client_contexts); + vec_free (ep->ip4_peers_to_notify); + vec_free (ep->ip6_peers_to_notify); + pool_put (dm->entries, ep); + + return 0; +} + +static int +dns_delete_by_name (dns_main_t * dm, u8 * name) +{ + int rv; + uword *p; + + if (dm->is_enabled == 0) + return VNET_API_ERROR_NAME_RESOLUTION_NOT_ENABLED; + + dns_cache_lock (dm); + p = hash_get_mem (dm->cache_entry_by_name, name); + if (!p) + { + dns_cache_unlock (dm); + return VNET_API_ERROR_NO_SUCH_ENTRY; + } + rv = vnet_dns_delete_entry_by_index_nolock (dm, p[0]); + + dns_cache_unlock (dm); + + return rv; +} + +static int +delete_random_entry (dns_main_t * dm) +{ + int rv; + u32 victim_index, start_index, i; + u32 limit; + dns_cache_entry_t *ep; + + if (dm->is_enabled == 0) + return VNET_API_ERROR_NAME_RESOLUTION_NOT_ENABLED; + + dns_cache_lock (dm); + limit = pool_elts (dm->entries); + start_index = random_u32 (&dm->random_seed) % limit; + + for (i = 0; i < limit; i++) + { + victim_index = (start_index + i) % limit; + + if (!pool_is_free_index (dm->entries, victim_index)) + { + ep = pool_elt_at_index (dm->entries, victim_index); + /* Delete only valid, non-static entries */ + if ((ep->flags & DNS_CACHE_ENTRY_FLAG_VALID) + && ((ep->flags & DNS_CACHE_ENTRY_FLAG_STATIC) == 0)) + { + rv = vnet_dns_delete_entry_by_index_nolock (dm, victim_index); + dns_cache_unlock (dm); + return rv; + } + } + } + dns_cache_unlock (dm); + + clib_warning ("Couldn't find an entry to delete?"); + return VNET_API_ERROR_UNSPECIFIED; +} + +static int +dns_add_static_entry (dns_main_t * dm, u8 * name, u8 * dns_reply_data) +{ + dns_cache_entry_t *ep; + uword *p; + int rv; + + if (dm->is_enabled == 0) + return VNET_API_ERROR_NAME_RESOLUTION_NOT_ENABLED; + + dns_cache_lock (dm); + p = hash_get_mem (dm->cache_entry_by_name, name); + if (p) + { + dns_cache_unlock (dm); + return VNET_API_ERROR_ENTRY_ALREADY_EXISTS; + } + + if (pool_elts (dm->entries) == dm->name_cache_size) + { + /* Will only fail if the cache is totally filled w/ static entries... */ + rv = delete_random_entry (dm); + if (rv) + { + dns_cache_unlock (dm); + return rv; + } + } + + pool_get (dm->entries, ep); + memset (ep, 0, sizeof (*ep)); + + /* Note: consumes the name vector */ + ep->name = name; + hash_set_mem (dm->cache_entry_by_name, ep->name, ep - dm->entries); + ep->flags = DNS_CACHE_ENTRY_FLAG_VALID | DNS_CACHE_ENTRY_FLAG_STATIC; + ep->dns_response = dns_reply_data; + + dns_cache_unlock (dm); + return 0; +} + +static int +dns_resolve_name (dns_main_t * dm, + u8 * name, u32 client_index, u32 client_context, + dns_cache_entry_t ** retp) +{ + dns_cache_entry_t *ep; + int rv; + f64 now; + uword *p; + + now = vlib_time_now (dm->vlib_main); + + /* In case we can't actually answer the question right now... */ + *retp = 0; + + dns_cache_lock (dm); + p = hash_get_mem (dm->cache_entry_by_name, name); + if (p) + { + ep = pool_elt_at_index (dm->entries, p[0]); + if (ep->flags & DNS_CACHE_ENTRY_FLAG_VALID) + { + /* Has the entry expired? */ + if (((ep->flags & DNS_CACHE_ENTRY_FLAG_STATIC) == 0) + && (now > ep->expiration_time)) + { + clib_warning ("Re-resolve %s", name); + /* Yes, kill it... */ + vnet_dns_delete_entry_by_index_nolock (dm, p[0]); + goto re_resolve; + } + + /* Note: caller must drop the lock! */ + *retp = ep; + return (0); + } + } + + if (pool_elts (dm->entries) == dm->name_cache_size) + { + /* Will only fail if the cache is totally filled w/ static entries... */ + rv = delete_random_entry (dm); + if (rv) + { + dns_cache_unlock (dm); + return rv; + } + } + +re_resolve: + /* add new hash table entry */ + pool_get (dm->entries, ep); + memset (ep, 0, sizeof (*ep)); + + ep->name = format (0, "%s%c", name, 0); + _vec_len (ep->name) = vec_len (ep->name) - 1; + + hash_set_mem (dm->cache_entry_by_name, ep->name, ep - dm->entries); + + vec_add1 (dm->unresolved_entries, ep - dm->entries); + vec_add1 (ep->api_clients_to_notify, client_index); + vec_add1 (ep->api_client_contexts, client_context); + vnet_send_dns_request (dm, ep); + dns_cache_unlock (dm); + + return 0; +} + +/** + * Handle cname indirection. JFC. Called with the cache locked. + * returns 0 if the reply is not a CNAME. + */ + +int +vnet_dns_cname_indirection_nolock (dns_main_t * dm, dns_cache_entry_t * ep, + u8 * reply) +{ + dns_header_t *h; + dns_query_t *qp; + dns_rr_t *rr; + u8 *curpos; + u8 *pos, *pos2; + int len, i; + u8 *cname = 0; + u8 *request = 0; + u32 qp_offset; + u16 flags; + u16 rcode; + + h = (dns_header_t *) reply; + flags = clib_net_to_host_u16 (h->flags); + rcode = flags & DNS_RCODE_MASK; + + /* See if the response is OK */ + switch (rcode) + { + case DNS_RCODE_NO_ERROR: + break; + + case DNS_RCODE_NAME_ERROR: + case DNS_RCODE_FORMAT_ERROR: + case DNS_RCODE_SERVER_FAILURE: + case DNS_RCODE_NOT_IMPLEMENTED: + case DNS_RCODE_REFUSED: + return 0; + } + + curpos = (u8 *) (h + 1); + pos = curpos; + len = *pos++; + + /* Skip the questions */ + for (i = 0; i < clib_net_to_host_u16 (h->qdcount); i++) + { + while (len) + { + pos += len; + len = *pos++; + } + qp = (dns_query_t *) pos; + pos += sizeof (*qp); + } + pos2 = pos; + /* expect a pointer chase here for a CNAME record */ + if ((pos2[0] & 0xC0) == 0xC0) + pos += 2; + else + return 0; + + rr = (dns_rr_t *) pos; + + /* This is a real record, not a CNAME record */ + if (clib_net_to_host_u16 (rr->type) != DNS_TYPE_CNAME) + return 0; + + /* Crap. Chase the CNAME name chain. */ + + cname = labels_to_name (rr->rdata, reply, &pos2); + request = name_to_labels (cname); + vec_free (cname); + + qp_offset = vec_len (request); + + /* Add space for the query header */ + vec_validate (request, qp_offset + sizeof (dns_query_t) - 1); + + qp = (dns_query_t *) (request + qp_offset); + + qp->type = clib_host_to_net_u16 (DNS_TYPE_ALL); + qp->class = clib_host_to_net_u16 (DNS_CLASS_IN); + + /* Punch in space for the dns_header_t */ + vec_insert (request, sizeof (dns_header_t), 0); + + h = (dns_header_t *) request; + + /* Transaction ID = pool index */ + h->id = clib_host_to_net_u16 (ep - dm->entries); + + /* Ask for a recursive lookup */ + h->flags = clib_host_to_net_u16 (DNS_RD | DNS_OPCODE_QUERY); + h->qdcount = clib_host_to_net_u16 (1); + h->nscount = 0; + h->arcount = 0; + + vec_free (ep->dns_request); + ep->dns_request = request; + ep->retry_timer = vlib_time_now (dm->vlib_main) + 2.0; + ep->retry_count = 0; + + /* + * Enable this to watch recursive resolution happen... + * fformat (stdout, "%U", format_dns_reply, request, 2); + */ + + if (ep->server_af == 1 /* ip6 */ ) + send_dns6_request (dm, ep, dm->ip6_name_servers + ep->server_rotor); + else + send_dns4_request (dm, ep, dm->ip4_name_servers + ep->server_rotor); + + vec_free (reply); + return (1); +} + +int +vnet_dns_response_to_reply (u8 * response, + vl_api_dns_resolve_name_reply_t * rmp, + u32 * min_ttlp) +{ + dns_header_t *h; + dns_query_t *qp; + dns_rr_t *rr; + int i, limit; + u8 len; + u8 *curpos, *pos; + u16 flags; + u16 rcode; + u32 ttl; + + h = (dns_header_t *) response; + flags = clib_net_to_host_u16 (h->flags); + rcode = flags & DNS_RCODE_MASK; + + /* See if the response is OK, etc. */ + switch (rcode) + { + default: + case DNS_RCODE_NO_ERROR: + break; + + case DNS_RCODE_NAME_ERROR: + case DNS_RCODE_FORMAT_ERROR: + return VNET_API_ERROR_NAME_SERVER_NO_SUCH_NAME; + + case DNS_RCODE_SERVER_FAILURE: + case DNS_RCODE_NOT_IMPLEMENTED: + case DNS_RCODE_REFUSED: + return VNET_API_ERROR_NAME_SERVER_NEXT_SERVER; + } + + /* No answers? Loser... */ + if (clib_net_to_host_u16 (h->anscount) < 1) + return VNET_API_ERROR_NAME_SERVER_NO_ADDRESSES; + + curpos = (u8 *) (h + 1); + + /* Skip the name we asked about */ + pos = curpos; + len = *pos++; + /* Should never happen, but stil... */ + if ((len & 0xC0) == 0xC0) + curpos += 2; + else + { + /* skip the name / label-set */ + while (len) + { + pos += len; + len = *pos++; + } + curpos = pos; + } + /* Skip queries */ + limit = clib_net_to_host_u16 (h->qdcount); + qp = (dns_query_t *) curpos; + qp += limit; + curpos = (u8 *) qp; + + /* Parse answers */ + limit = clib_net_to_host_u16 (h->anscount); + + for (i = 0; i < limit; i++) + { + pos = curpos; + + /* Expect pointer chases in the answer section... */ + if ((pos[0] & 0xC0) == 0xC0) + curpos += 2; + else + { + len = *pos++; + while (len) + { + if ((pos[0] & 0xC0) == 0xC0) + { + curpos = pos + 2; + break; + } + pos += len; + len = *pos++; + } + curpos = pos; + } + + rr = (dns_rr_t *) curpos; + + switch (clib_net_to_host_u16 (rr->type)) + { + case DNS_TYPE_A: + /* Collect an ip4 address. Do not pass go. Do not collect $200 */ + memcpy (rmp->ip4_address, rr->rdata, sizeof (ip4_address_t)); + rmp->ip4_set = 1; + ttl = clib_net_to_host_u32 (rr->ttl); + if (min_ttlp && *min_ttlp > ttl) + *min_ttlp = ttl; + break; + case DNS_TYPE_AAAA: + /* Collect an ip6 address. Do not pass go. Do not collect $200 */ + memcpy (rmp->ip6_address, rr->rdata, sizeof (ip6_address_t)); + ttl = clib_net_to_host_u32 (rr->ttl); + if (min_ttlp && *min_ttlp > ttl) + *min_ttlp = ttl; + rmp->ip6_set = 1; + break; + default: + break; + } + /* Might as well stop ASAP */ + if (rmp->ip4_set && rmp->ip6_set) + break; + curpos += sizeof (*rr) + clib_net_to_host_u16 (rr->rdlength); + } + + if ((rmp->ip4_set + rmp->ip6_set) == 0) + return VNET_API_ERROR_NAME_SERVER_NO_ADDRESSES; + return 0; +} + +static void +vl_api_dns_resolve_name_t_handler (vl_api_dns_resolve_name_t * mp) +{ + dns_main_t *dm = &dns_main; + vl_api_dns_resolve_name_reply_t *rmp; + dns_cache_entry_t *ep; + int rv; + + /* Sanitize the name slightly */ + mp->name[ARRAY_LEN (mp->name) - 1] = 0; + + rv = dns_resolve_name (dm, mp->name, mp->client_index, mp->context, &ep); + + /* Error, e.g. not enabled? Tell the user */ + if (rv < 0) + { + REPLY_MACRO (VL_API_DNS_RESOLVE_NAME_REPLY); + return; + } + + /* Resolution pending? Don't reply... */ + if (ep == 0) + return; + + /* *INDENT-OFF* */ + REPLY_MACRO2(VL_API_DNS_RESOLVE_NAME_REPLY, + ({ + rv = vnet_dns_response_to_reply (ep->dns_response, rmp, 0 /* ttl-ptr */); + rmp->retval = clib_host_to_net_u32 (rv); + })); + /* *INDENT-ON* */ + + /* + * dns_resolve_name leaves the cache locked when it returns + * a cached result, so unlock it here. + */ + dns_cache_unlock (dm); +} + +#define vl_msg_name_crc_list +#include +#undef vl_msg_name_crc_list + +static void +setup_message_id_table (api_main_t * am) +{ +#define _(id,n,crc) vl_msg_api_add_msg_name_crc (am, #n "_" #crc, id); + foreach_vl_msg_name_crc_dns; +#undef _ +} + +#define foreach_dns_api_msg \ +_(DNS_ENABLE_DISABLE, dns_enable_disable) \ +_(DNS_NAME_SERVER_ADD_DEL, dns_name_server_add_del) \ +_(DNS_RESOLVE_NAME, dns_resolve_name) + +static clib_error_t * +dns_api_hookup (vlib_main_t * vm) +{ +#define _(N,n) \ + vl_msg_api_set_handlers(VL_API_##N, #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_dns_api_msg; +#undef _ + + setup_message_id_table (&api_main); + return 0; +} + +VLIB_API_INIT_FUNCTION (dns_api_hookup); + + +static clib_error_t * +dns_config_fn (vlib_main_t * vm, unformat_input_t * input) +{ + dns_main_t *dm = &dns_main; + + while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT) + { + if (unformat (input, "max-cache-size %u", &dm->name_cache_size)) + ; + else if (unformat (input, "max-ttl %u", &dm->max_ttl_in_seconds)) + ; + else + return clib_error_return (0, "unknown input `%U'", + format_unformat_error, input); + } + return 0; +} + +VLIB_CONFIG_FUNCTION (dns_config_fn, "dns"); + +static clib_error_t * +dns_init (vlib_main_t * vm) +{ + dns_main_t *dm = &dns_main; + + dm->vlib_main = vm; + dm->vnet_main = vnet_get_main (); + dm->name_cache_size = 65535; + dm->max_ttl_in_seconds = 86400; + dm->random_seed = 0xDEADDABE; + + udp_register_dst_port (vm, UDP_DST_PORT_dns_reply, dns46_reply_node.index, + 1 /* is_ip4 */ ); + + udp_register_dst_port (vm, UDP_DST_PORT_dns_reply6, dns46_reply_node.index, + 0 /* is_ip4 */ ); + +#if 0 + udp_register_dst_port (vm, UDP_DST_PORT_dns, dns4_request_node.index, + 1 /* is_ip4 */ ); + udp_register_dst_port (vm, UDP_DST_PORT_dns6, dns6_request_node.index, + 0 /* is_ip4 */ ); +#endif + + return 0; +} + +VLIB_INIT_FUNCTION (dns_init); + +uword +unformat_dns_reply (unformat_input_t * input, va_list * args) +{ + u8 **result = va_arg (*args, u8 **); + u8 **namep = va_arg (*args, u8 **); + ip4_address_t a4; + ip6_address_t a6; + int a4_set = 0; + int a6_set = 0; + u8 *name; + int name_set = 0; + u8 *ce; + u32 qp_offset; + dns_header_t *h; + dns_query_t *qp; + dns_rr_t *rr; + u8 *rru8; + + if (unformat (input, "%v", &name)) + name_set = 1; + + if (unformat (input, "%U", unformat_ip4_address, &a4)) + { + a4_set = 1; + if (unformat (input, "%U", unformat_ip6_address, &a6)) + a6_set = 1; + } + + if (unformat (input, "%U", unformat_ip6_address, &a6)) + { + a6_set = 1; + if (unformat (input, "%U", unformat_ip4_address, &a6)) + a4_set = 1; + } + + /* Must have a name */ + if (!name_set) + return 0; + + /* Must have at least one address */ + if (!(a4_set + a6_set)) + return 0; + + /* Build a fake DNS cache entry string, one hemorrhoid at a time */ + ce = name_to_labels (name); + qp_offset = vec_len (ce); + + /* Add space for the query header */ + vec_validate (ce, qp_offset + sizeof (dns_query_t) - 1); + qp = (dns_query_t *) (ce + qp_offset); + + qp->type = clib_host_to_net_u16 (DNS_TYPE_ALL); + qp->class = clib_host_to_net_u16 (DNS_CLASS_IN); + + /* Punch in space for the dns_header_t */ + vec_insert (ce, sizeof (dns_header_t), 0); + + h = (dns_header_t *) ce; + + /* Fake Transaction ID */ + h->id = 0xFFFF; + + h->flags = clib_host_to_net_u16 (DNS_RD | DNS_RA); + h->qdcount = clib_host_to_net_u16 (1); + h->anscount = clib_host_to_net_u16 (a4_set + a6_set); + h->nscount = 0; + h->arcount = 0; + + /* Now append one or two A/AAAA RR's... */ + if (a4_set) + { + /* Pointer to the name (DGMS) */ + vec_add1 (ce, 0xC0); + vec_add1 (ce, 0x0C); + vec_add2 (ce, rru8, sizeof (*rr) + 4); + rr = (void *) rru8; + rr->type = clib_host_to_net_u16 (DNS_TYPE_A); + rr->class = clib_host_to_net_u16 (DNS_CLASS_IN); + rr->ttl = clib_host_to_net_u32 (86400); + rr->rdlength = clib_host_to_net_u16 (4); + memcpy (rr->rdata, &a4, sizeof (a4)); + } + if (a6_set) + { + /* Pointer to the name (DGMS) */ + vec_add1 (ce, 0xC0); + vec_add1 (ce, 0x0C); + vec_add2 (ce, rru8, sizeof (*rr) + 16); + rr = (void *) rru8; + rr->type = clib_host_to_net_u16 (DNS_TYPE_AAAA); + rr->class = clib_host_to_net_u16 (DNS_CLASS_IN); + rr->ttl = clib_host_to_net_u32 (86400); + rr->rdlength = clib_host_to_net_u16 (16); + memcpy (rr->rdata, &a6, sizeof (a6)); + } + *result = ce; + if (namep) + *namep = name; + else + vec_free (name); + + return 1; +} + +u8 * +format_dns_query (u8 * s, va_list * args) +{ + u8 **curpos = va_arg (*args, u8 **); + int verbose = va_arg (*args, int); + u8 *pos; + dns_query_t *qp; + int len, i; + if (verbose > 1) + s = format (s, " Name: "); + + /* Unwind execrated counted-label sheit */ + pos = *curpos; + len = *pos++; + + while (len) + { + for (i = 0; i < len; i++) + vec_add1 (s, *pos++); + + len = *pos++; + if (len) + vec_add1 (s, '.'); + else + { + vec_add1 (s, ':'); + vec_add1 (s, ' '); + } + } + + qp = (dns_query_t *) pos; + if (verbose > 1) + { + switch (clib_net_to_host_u16 (qp->type)) + { + case DNS_TYPE_A: + s = format (s, "type A\n"); + break; + case DNS_TYPE_AAAA: + s = format (s, "type AAAA\n"); + break; + case DNS_TYPE_ALL: + s = format (s, "type ALL\n"); + break; + + default: + s = format (s, "type %d\n", clib_net_to_host_u16 (qp->type)); + break; + } + } + + pos += sizeof (*qp); + + *curpos = pos; + return s; +} + +/** + * format dns reply data + * verbose > 1, dump everything + * verbose == 1, dump all A and AAAA records + * verbose == 0, dump one A record, and one AAAA record + */ + +u8 * +format_dns_reply_data (u8 * s, va_list * args) +{ + u8 *reply = va_arg (*args, u8 *); + u8 **curpos = va_arg (*args, u8 **); + int verbose = va_arg (*args, int); + int *print_ip4 = va_arg (*args, int *); + int *print_ip6 = va_arg (*args, int *); + int len; + u8 *pos, *pos2; + dns_rr_t *rr; + int i; + int initial_pointer_chase = 0; + u16 *tp; + + pos = pos2 = *curpos; + + if (verbose > 1) + s = format (s, " "); + + /* chase pointer? almost always yes here... */ + if (pos2[0] == 0xc0) + { + pos2 = reply + pos2[1]; + pos += 2; + initial_pointer_chase = 1; + } + + len = *pos2++; + + while (len) + { + for (i = 0; i < len; i++) + { + if (verbose > 1) + vec_add1 (s, *pos2); + pos2++; + } + len = *pos2++; + if (len) + { + if (verbose > 1) + vec_add1 (s, '.'); + } + else + { + if (verbose > 1) + vec_add1 (s, ' '); + } + } + + if (initial_pointer_chase == 0) + pos = pos2; + + rr = (dns_rr_t *) pos; + + switch (clib_net_to_host_u16 (rr->type)) + { + case DNS_TYPE_A: + if (verbose > 1) + { + s = format (s, "A: ttl %d %U\n", clib_net_to_host_u32 (rr->ttl), + format_ip4_address, rr->rdata); + } + else + { + if (*print_ip4) + s = format (s, "%U [%u] ", format_ip4_address, rr->rdata, + clib_net_to_host_u32 (rr->ttl)); + if (verbose == 0) + *print_ip4 = 0; + + } + pos += sizeof (*rr) + 4; + break; + + case DNS_TYPE_AAAA: + if (verbose > 1) + { + s = format (s, "AAAA: ttl %d %U\n", clib_net_to_host_u32 (rr->ttl), + format_ip6_address, rr->rdata); + } + else + { + if (*print_ip6) + s = format (s, "%U [%u] ", format_ip6_address, rr->rdata, + clib_net_to_host_u32 (rr->ttl)); + if (verbose == 0) + *print_ip6 = 0; + } + pos += sizeof (*rr) + 16; + break; + + case DNS_TYPE_TEXT: + if (verbose > 1) + { + s = format (s, "TEXT: "); + for (i = 0; i < clib_net_to_host_u16 (rr->rdlength); i++) + vec_add1 (s, rr->rdata[i]); + vec_add1 (s, '\n'); + } + pos += sizeof (*rr) + clib_net_to_host_u16 (rr->rdlength); + break; + + case DNS_TYPE_NAMESERVER: + if (verbose > 1) + { + s = format (s, "Nameserver: "); + pos2 = rr->rdata; + + /* chase pointer? */ + if (pos2[0] == 0xc0) + pos2 = reply + pos2[1]; + + len = *pos2++; + + while (len) + { + for (i = 0; i < len; i++) + vec_add1 (s, *pos2++); + + /* chase pointer, typically to offset 12... */ + if (pos2[0] == 0xC0) + pos2 = reply + pos2[1]; + + len = *pos2++; + if (len) + vec_add1 (s, '.'); + else + vec_add1 (s, '\n'); + } + } + pos += sizeof (*rr) + clib_net_to_host_u16 (rr->rdlength); + break; + + case DNS_TYPE_MAIL_EXCHANGE: + if (verbose > 1) + { + tp = (u16 *) rr->rdata; + + s = format (s, "Mail Exchange: Preference %d ", (u32) + clib_net_to_host_u16 (*tp)); + + pos2 = rr->rdata + 2; + + /* chase pointer? */ + if (pos2[0] == 0xc0) + pos2 = reply + pos2[1]; + + len = *pos2++; + + while (len) + { + for (i = 0; i < len; i++) + vec_add1 (s, *pos2++); + + /* chase pointer */ + if (pos2[0] == 0xC0) + pos2 = reply + pos2[1]; + + len = *pos2++; + if (len) + vec_add1 (s, '.'); + else + vec_add1 (s, '\n'); + } + } + + pos += sizeof (*rr) + clib_net_to_host_u16 (rr->rdlength); + break; + + case DNS_TYPE_CNAME: + if (verbose > 1) + { + tp = (u16 *) rr->rdata; + + s = format (s, "CNAME: "); + + pos2 = rr->rdata; + + /* chase pointer? */ + if (pos2[0] == 0xc0) + pos2 = reply + pos2[1]; + + len = *pos2++; + + while (len) + { + for (i = 0; i < len; i++) + vec_add1 (s, *pos2++); + + /* chase pointer */ + if (pos2[0] == 0xC0) + pos2 = reply + pos2[1]; + + len = *pos2++; + if (len) + vec_add1 (s, '.'); + else + vec_add1 (s, '\n'); + } + } + pos += sizeof (*rr) + clib_net_to_host_u16 (rr->rdlength); + break; + + default: + if (verbose > 1) + s = format (s, "type %d: len %d\n", + (int) clib_net_to_host_u16 (rr->type), + sizeof (*rr) + clib_net_to_host_u16 (rr->rdlength)); + pos += sizeof (*rr) + clib_net_to_host_u16 (rr->rdlength); + break; + } + + *curpos = pos; + + return s; +} + +u8 * +format_dns_reply (u8 * s, va_list * args) +{ + u8 *reply_as_u8 = va_arg (*args, u8 *); + int verbose = va_arg (*args, int); + dns_header_t *h; + u16 id, flags; + u8 *curpos; + int i; + int print_ip4 = 1; + int print_ip6 = 1; + + h = (dns_header_t *) reply_as_u8; + id = clib_net_to_host_u16 (h->id); + flags = clib_net_to_host_u16 (h->flags); + + if (verbose > 1) + { + s = format (s, "DNS %s: id %d\n", (flags & DNS_QR) ? "reply" : "query", + id); + s = format (s, " %s %s %s %s\n", + (flags & DNS_RA) ? "recur" : "no-recur", + (flags & DNS_RD) ? "recur-des" : "no-recur-des", + (flags & DNS_TC) ? "trunc" : "no-trunc", + (flags & DNS_AA) ? "auth" : "non-auth"); + s = format (s, " %d queries, %d answers, %d name-servers," + " %d add'l recs\n", + clib_net_to_host_u16 (h->qdcount), + clib_net_to_host_u16 (h->anscount), + clib_net_to_host_u16 (h->nscount), + clib_net_to_host_u16 (h->arcount)); + } + + curpos = (u8 *) (h + 1); + + if (h->qdcount) + { + if (verbose > 1) + s = format (s, " Queries:\n"); + for (i = 0; i < clib_net_to_host_u16 (h->qdcount); i++) + { + /* The query is variable-length, so curpos is a value-result parm */ + s = format (s, "%U", format_dns_query, &curpos, verbose); + } + } + if (h->anscount) + { + if (verbose > 1) + s = format (s, " Replies:\n"); + + for (i = 0; i < clib_net_to_host_u16 (h->anscount); i++) + { + /* curpos is a value-result parm */ + s = format (s, "%U", format_dns_reply_data, reply_as_u8, &curpos, + verbose, &print_ip4, &print_ip6); + } + } + return s; +} + +u8 * +format_dns_cache (u8 * s, va_list * args) +{ + dns_main_t *dm = va_arg (*args, dns_main_t *); + f64 now = va_arg (*args, f64); + int verbose = va_arg (*args, int); + u8 *name = va_arg (*args, u8 *); + dns_cache_entry_t *ep; + char *ss; + uword *p; + + if (dm->is_enabled == 0) + { + s = format (s, "The DNS cache is disabled..."); + return s; + } + + if (pool_elts (dm->entries) == 0) + { + s = format (s, "The DNS cache is empty..."); + return s; + } + + dns_cache_lock (dm); + + if (name) + { + p = hash_get_mem (dm->cache_entry_by_name, name); + if (!p) + { + s = format (s, "%s is not in the cache...", name); + dns_cache_unlock (dm); + return (s); + } + + ep = pool_elt_at_index (dm->entries, p[0]); + /* Magic to spit out a C-initializer to research hemorrhoids... */ + if (verbose == 3) + { + int i, j; + s = format (s, "static u8 dns_reply_data_initializer[] =\n"); + s = format (s, "{\n"); + j = 0; + for (i = 0; i < vec_len (ep->dns_response); i++) + { + if (j++ == 8) + { + j = 0; + vec_add1 (s, '\n'); + } + s = format (s, "0x%02x, ", ep->dns_response[i]); + } + s = format (s, "};\n"); + } + else + { + if (ep->flags & DNS_CACHE_ENTRY_FLAG_VALID) + { + ASSERT (ep->dns_response); + if (ep->flags & DNS_CACHE_ENTRY_FLAG_STATIC) + ss = "[S] "; + else + ss = " "; + + s = format (s, "%s%s -> %U", ss, ep->name, + format_dns_reply, ep->dns_response, verbose); + if (!(ep->flags & DNS_CACHE_ENTRY_FLAG_STATIC)) + { + f64 time_left = ep->expiration_time - now; + if (time_left > 0.0) + s = format (s, " TTL left %.1f", time_left); + else + s = format (s, " EXPIRED"); + } + } + else + { + ASSERT (ep->dns_request); + s = format (s, "[P] %U", format_dns_reply, ep->dns_request, + verbose); + } + vec_add1 (s, '\n'); + } + return s; + } + + /* *INDENT-OFF* */ + pool_foreach (ep, dm->entries, + ({ + if (ep->flags & DNS_CACHE_ENTRY_FLAG_VALID) + { + ASSERT (ep->dns_response); + if (ep->flags & DNS_CACHE_ENTRY_FLAG_STATIC) + ss = "[S] "; + else + ss = " "; + + s = format (s, "%s%s -> %U", ss, ep->name, + format_dns_reply, + ep->dns_response, + verbose); + if (!(ep->flags & DNS_CACHE_ENTRY_FLAG_STATIC)) + { + f64 time_left = ep->expiration_time - now; + if (time_left > 0.0) + s = format (s, " TTL left %.1f", time_left); + else + s = format (s, " EXPIRED"); + } + } + else + { + ASSERT (ep->dns_request); + s = format (s, "[P] %U", format_dns_reply, ep->dns_request, + verbose); + } + vec_add1 (s, '\n'); + })); + /* *INDENT-ON* */ + + dns_cache_unlock (dm); + + return s; +} + +static clib_error_t * +show_dns_cache_command_fn (vlib_main_t * vm, + unformat_input_t * input, vlib_cli_command_t * cmd) +{ + dns_main_t *dm = &dns_main; + int verbose = 0; + u8 *name = 0; + f64 now = vlib_time_now (vm); + + while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT) + { + if (unformat (input, "verbose %d", &verbose)) + ; + else if (unformat (input, "verbose")) + verbose = 1; + else if (unformat (input, "name %s", &name)) + ; + else + return clib_error_return (0, "unknown input `%U'", + format_unformat_error, input); + } + + vlib_cli_output (vm, "%U", format_dns_cache, dm, now, verbose, name); + + return 0; +} + +/* *INDENT-OFF* */ +VLIB_CLI_COMMAND (show_dns_cache_command) = +{ + .path = "show dns cache", + .short_help = "show dns cache [verbose [nn]]", + .function = show_dns_cache_command_fn, +}; +/* *INDENT-ON* */ + +static clib_error_t * +dns_cache_add_del_command_fn (vlib_main_t * vm, + unformat_input_t * input, + vlib_cli_command_t * cmd) +{ + dns_main_t *dm = &dns_main; + u8 *dns_reply_data; + u8 *name; + int is_add = -1; + int is_clear = -1; + int rv; + clib_error_t *error; + + if (unformat (input, "add")) + is_add = 1; + if (unformat (input, "del")) + is_add = 0; + if (unformat (input, "clear")) + is_clear = 1; + + if (is_add == -1 && is_clear == -1) + return clib_error_return (0, "add / del / clear required..."); + + if (is_clear == 1) + { + rv = dns_cache_clear (dm); + switch (rv) + { + case 0: + return 0; + + case VNET_API_ERROR_NAME_RESOLUTION_NOT_ENABLED: + error = clib_error_return (0, "Name resolution not enabled"); + return error; + } + } + + /* Delete (by name)? */ + if (is_add == 0) + { + if (unformat (input, "%v", &name)) + { + rv = dns_delete_by_name (dm, name); + switch (rv) + { + case VNET_API_ERROR_NO_SUCH_ENTRY: + error = clib_error_return (0, "%v not in the cache...", name); + vec_free (name); + return error; + + case VNET_API_ERROR_NAME_RESOLUTION_NOT_ENABLED: + error = clib_error_return (0, "Name resolution not enabled"); + vec_free (name); + return error; + + case 0: + vec_free (name); + return 0; + + default: + error = clib_error_return (0, "dns_delete_by_name returned %d", + rv); + vec_free (name); + return error; + } + } + return clib_error_return (0, "unknown input `%U'", + format_unformat_error, input); + } + + /* Note: dns_add_static_entry consumes the name vector if OK... */ + if (unformat (input, "%U", unformat_dns_reply, &dns_reply_data, &name)) + { + rv = dns_add_static_entry (dm, name, dns_reply_data); + switch (rv) + { + case VNET_API_ERROR_ENTRY_ALREADY_EXISTS: + vec_free (name); + vec_free (dns_reply_data); + return clib_error_return (0, "%v already in the cache...", name); + case 0: + return 0; + + default: + return clib_error_return (0, "dns_add_static_entry returned %d", + rv); + } + } + + return 0; +} + +/* *INDENT-OFF* */ +VLIB_CLI_COMMAND (dns_cache_add_del_command) = +{ + .path = "dns cache", + .short_help = "dns cache [add|del|clear] [ip4][ip6]", + .function = dns_cache_add_del_command_fn, +}; +/* *INDENT-ON* */ + +#define DNS_FORMAT_TEST 1 + +#if DNS_FORMAT_TEST > 0 +#if 0 +/* yahoo.com */ +static u8 dns_reply_data_initializer[] = + { 0x0, 0x0, 0x81, 0x80, 0x0, 0x1, 0x0, 0x10, 0x0, 0x0, 0x0, 0x0, 0x5, + 0x79, 0x61, 0x68, 0x6f, 0x6f, 0x3, 0x63, 0x6f, 0x6d, + 0x0, /* null lbl */ + 0x0, 0xff, /* type ALL */ + 0x0, 0x1, /* class IN */ + 0xc0, 0xc, /* pointer to yahoo.com name */ + 0x0, 0x10, 0x0, 0x1, 0x0, 0x0, 0x6, 0x5c, 0x0, 0x24, 0x23, + 0x76, 0x3d, 0x73, 0x70, 0x66, 0x31, 0x20, 0x72, 0x65, 0x64, 0x69, 0x72, + 0x65, 0x63, 0x74, 0x3d, 0x5f, 0x73, 0x70, 0x66, 0x2e, 0x6d, 0x61, 0x69, + 0x6c, 0x2e, 0x79, 0x61, 0x68, 0x6f, 0x6f, 0x2e, 0x63, 0x6f, 0x6d, 0xc0, + 0xc, 0x0, 0x2, 0x0, 0x1, 0x0, 0x1, 0x50, 0xd4, 0x0, 0x6, 0x3, 0x6e, 0x73, + 0x35, 0xc0, 0xc, 0xc0, 0xc, 0x0, 0x2, 0x0, 0x1, 0x0, 0x1, 0x50, 0xd4, 0x0, + 0x6, 0x3, 0x6e, 0x73, 0x34, 0xc0, 0xc, 0xc0, 0xc, 0x0, 0x2, 0x0, 0x1, 0x0, + 0x1, 0x50, 0xd4, 0x0, 0x6, 0x3, 0x6e, 0x73, 0x31, 0xc0, 0xc, 0xc0, 0xc, + 0x0, 0x2, 0x0, 0x1, 0x0, 0x1, 0x50, 0xd4, 0x0, 0x6, 0x3, 0x6e, 0x73, 0x32, + 0xc0, 0xc, 0xc0, 0xc, 0x0, 0x2, 0x0, 0x1, 0x0, 0x1, 0x50, 0xd4, 0x0, 0x6, + 0x3, 0x6e, 0x73, 0x33, 0xc0, 0xc, 0xc0, 0xc, 0x0, 0xf, 0x0, 0x1, 0x0, 0x0, + 0x6, 0x5c, 0x0, 0x19, 0x0, 0x1, 0x4, 0x6d, 0x74, 0x61, 0x36, 0x3, 0x61, + 0x6d, 0x30, 0x8, 0x79, 0x61, 0x68, 0x6f, 0x6f, 0x64, 0x6e, 0x73, 0x3, + 0x6e, + 0x65, 0x74, 0x0, 0xc0, 0xc, 0x0, 0xf, 0x0, 0x1, 0x0, 0x0, 0x6, 0x5c, 0x0, + 0x9, 0x0, 0x1, 0x4, 0x6d, 0x74, 0x61, 0x37, 0xc0, 0xb8, 0xc0, 0xc, 0x0, + 0xf, 0x0, 0x1, 0x0, 0x0, 0x6, 0x5c, 0x0, 0x9, 0x0, 0x1, 0x4, 0x6d, 0x74, + 0x61, 0x35, 0xc0, 0xb8, 0xc0, 0xc, 0x0, 0x1c, 0x0, 0x1, 0x0, 0x0, 0x6, + 0x5c, 0x0, 0x10, 0x20, 0x1, 0x49, 0x98, 0x0, 0x44, 0x2, 0x4, 0x0, 0x0, + 0x0, + 0x0, 0x0, 0x0, 0x0, 0xa7, 0xc0, 0xc, 0x0, 0x1c, 0x0, 0x1, 0x0, 0x0, 0x6, + 0x5c, 0x0, 0x10, 0x20, 0x1, 0x49, 0x98, 0x0, 0xc, 0xa, 0x6, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x2, 0x40, 0x8, 0xc0, 0xc, 0x0, 0x1c, 0x0, 0x1, 0x0, 0x0, 0x6, + 0x5c, 0x0, 0x10, 0x20, 0x1, 0x49, 0x98, 0x0, 0x58, 0xc, 0x2, 0x0, 0x0, + 0x0, + 0x0, 0x0, 0x0, 0x0, 0xa9, 0xc0, 0xc, 0x0, 0x1, 0x0, 0x1, 0x0, 0x0, 0x6, + 0x5c, 0x0, 0x4, 0x62, 0x8a, 0xfd, 0x6d, 0xc0, 0xc, 0x0, 0x1, 0x0, 0x1, + 0x0, + 0x0, 0x6, 0x5c, 0x0, 0x4, 0xce, 0xbe, 0x24, 0x2d, 0xc0, 0xc, 0x0, 0x1, + 0x0, + 0x1, 0x0, 0x0, 0x6, 0x5c, 0x0, 0x4, 0x62, 0x8b, 0xb4, 0x95, 0xc0, 0xc, + 0x0, + 0x6, 0x0, 0x1, 0x0, 0x0, 0x6, 0x5c, 0x0, 0x2d, 0xc0, 0x7b, 0xa, 0x68, + 0x6f, + 0x73, 0x74, 0x6d, 0x61, 0x73, 0x74, 0x65, 0x72, 0x9, 0x79, 0x61, 0x68, + 0x6f, 0x6f, 0x2d, 0x69, 0x6e, 0x63, 0xc0, 0x12, 0x78, 0x3a, 0x85, 0x44, + 0x0, 0x0, 0xe, 0x10, 0x0, 0x0, 0x1, 0x2c, 0x0, 0x1b, 0xaf, 0x80, 0x0, 0x0, + 0x2, 0x58 +}; + +/* www.cisco.com, has no addresses in reply */ +static u8 dns_reply_data_initializer[] = { + 0x00, 0x01, 0x81, 0x80, 0x00, 0x01, 0x00, 0x01, + 0x00, 0x00, 0x00, 0x00, 0x03, 0x77, 0x77, 0x77, 0x05, + 0x63, 0x69, 0x73, 0x63, 0x6f, 0x03, 0x63, 0x6f, 0x6d, + + 0x00, 0x00, 0xff, 0x00, 0x01, 0xc0, 0x0c, 0x00, 0x05, + 0x00, 0x01, 0x00, 0x00, 0x0b, 0xd3, 0x00, 0x1a, 0x03, + 0x77, 0x77, 0x77, 0x05, 0x63, 0x69, 0x73, 0x63, 0x6f, + 0x03, 0x63, 0x6f, 0x6d, 0x06, 0x61, 0x6b, 0x61, 0x64, + 0x6e, 0x73, 0x03, 0x6e, 0x65, 0x74, 0x00, +}; +#else +/* google.com */ +static u8 dns_reply_data_initializer[] = + { 0x0, 0x0, 0x81, 0x80, 0x0, 0x1, 0x0, 0xe, 0x0, 0x0, 0x0, 0x0, 0x6, + 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x3, 0x63, 0x6f, 0x6d, 0x0, 0x0, 0xff, + 0x0, 0x1, 0xc0, 0xc, 0x0, 0x1, 0x0, 0x1, 0x0, 0x0, 0x1, 0x2b, 0x0, 0x4, + 0xac, 0xd9, 0x3, 0x2e, 0xc0, 0xc, 0x0, 0x1c, 0x0, 0x1, 0x0, 0x0, 0x1, + 0x2b, + 0x0, 0x10, 0x26, 0x7, 0xf8, 0xb0, 0x40, 0x4, 0x8, 0xf, 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x20, 0xe, 0xc0, 0xc, 0x0, 0x2, 0x0, 0x1, 0x0, 0x1, 0x51, 0x7f, + 0x0, 0x6, 0x3, 0x6e, 0x73, 0x31, 0xc0, 0xc, 0xc0, 0xc, 0x0, 0x6, 0x0, 0x1, + 0x0, 0x0, 0x0, 0x3b, 0x0, 0x22, 0xc0, 0x54, 0x9, 0x64, 0x6e, 0x73, 0x2d, + 0x61, 0x64, 0x6d, 0x69, 0x6e, 0xc0, 0xc, 0xa, 0x3d, 0xc7, 0x30, 0x0, 0x0, + 0x3, 0x84, 0x0, 0x0, 0x3, 0x84, 0x0, 0x0, 0x7, 0x8, 0x0, 0x0, 0x0, 0x3c, + 0xc0, 0xc, 0x0, 0xf, 0x0, 0x1, 0x0, 0x0, 0x2, 0x57, 0x0, 0x11, 0x0, 0x1e, + 0x4, 0x61, 0x6c, 0x74, 0x32, 0x5, 0x61, 0x73, 0x70, 0x6d, 0x78, 0x1, 0x6c, + 0xc0, 0xc, 0xc0, 0xc, 0x0, 0xf, 0x0, 0x1, 0x0, 0x0, 0x2, 0x57, 0x0, 0x4, + 0x0, 0xa, 0xc0, 0x9b, 0xc0, 0xc, 0x0, 0x10, 0x0, 0x1, 0x0, 0x0, 0xe, 0xf, + 0x0, 0x24, 0x23, 0x76, 0x3d, 0x73, 0x70, 0x66, 0x31, 0x20, 0x69, 0x6e, + 0x63, 0x6c, 0x75, 0x64, 0x65, 0x3a, 0x5f, 0x73, 0x70, 0x66, 0x2e, 0x67, + 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x2e, 0x63, 0x6f, 0x6d, 0x20, 0x7e, 0x61, + 0x6c, 0x6c, 0xc0, 0xc, 0x0, 0x2, 0x0, 0x1, 0x0, 0x1, 0x51, 0x7f, 0x0, 0x6, + 0x3, 0x6e, 0x73, 0x32, 0xc0, 0xc, 0xc0, 0xc, 0x1, 0x1, 0x0, 0x1, 0x0, 0x1, + 0x51, 0x7f, 0x0, 0xf, 0x0, 0x5, 0x69, 0x73, 0x73, 0x75, 0x65, 0x70, 0x6b, + 0x69, 0x2e, 0x67, 0x6f, 0x6f, 0x67, 0xc0, 0xc, 0x0, 0x2, 0x0, 0x1, 0x0, + 0x1, 0x51, 0x7f, 0x0, 0x6, 0x3, 0x6e, 0x73, 0x34, 0xc0, 0xc, 0xc0, 0xc, + 0x0, 0xf, 0x0, 0x1, 0x0, 0x0, 0x2, 0x57, 0x0, 0x9, 0x0, 0x28, 0x4, 0x61, + 0x6c, 0x74, 0x33, 0xc0, 0x9b, 0xc0, 0xc, 0x0, 0x2, 0x0, 0x1, 0x0, 0x1, + 0x51, 0x7f, 0x0, 0x6, 0x3, 0x6e, 0x73, 0x33, 0xc0, 0xc, 0xc0, 0xc, 0x0, + 0xf, 0x0, 0x1, 0x0, 0x0, 0x2, 0x57, 0x0, 0x9, 0x0, 0x32, 0x4, 0x61, 0x6c, + 0x74, 0x34, 0xc0, 0x9b, 0xc0, 0xc, 0x0, 0xf, 0x0, 0x1, 0x0, 0x0, 0x2, + 0x57, + 0x0, 0x9, 0x0, 0x14, 0x4, 0x61, 0x6c, 0x74, 0x31, 0xc0, 0x9b +}; +#endif + +static clib_error_t * +test_dns_fmt_command_fn (vlib_main_t * vm, + unformat_input_t * input, vlib_cli_command_t * cmd) +{ + u8 *dns_reply_data = 0; + int verbose = 0; + int rv; + vl_api_dns_resolve_name_reply_t _rm, *rmp = &_rm; + + while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT) + { + if (unformat (input, "verbose %d", &verbose)) + ; + else if (unformat (input, "verbose")) + verbose = 1; + else + return clib_error_return (0, "unknown input `%U'", + format_unformat_error, input); + } + + vec_validate (dns_reply_data, ARRAY_LEN (dns_reply_data_initializer) - 1); + + memcpy (dns_reply_data, dns_reply_data_initializer, + ARRAY_LEN (dns_reply_data_initializer)); + + vlib_cli_output (vm, "%U", format_dns_reply, dns_reply_data, verbose); + + memset (rmp, 0, sizeof (*rmp)); + + rv = vnet_dns_response_to_reply (dns_reply_data, rmp, 0 /* ttl-ptr */ ); + + switch (rv) + { + case VNET_API_ERROR_NAME_SERVER_NO_ADDRESSES: + vlib_cli_output (vm, "no addresses found..."); + break; + + default: + vlib_cli_output (vm, "response to reply returned %d", rv); + break; + + case 0: + if (rmp->ip4_set) + vlib_cli_output (vm, "ip4 address: %U", format_ip4_address, + (ip4_address_t *) rmp->ip4_address); + if (rmp->ip6_set) + vlib_cli_output (vm, "ip6 address: %U", format_ip6_address, + (ip6_address_t *) rmp->ip6_address); + break; + } + + vec_free (dns_reply_data); + + return 0; +} + + +/* *INDENT-OFF* */ +VLIB_CLI_COMMAND (test_dns_fmt_command) = +{ + .path = "test dns format", + .short_help = "test dns format", + .function = test_dns_fmt_command_fn, +}; +/* *INDENT-ON* */ + +static clib_error_t * +test_dns_unfmt_command_fn (vlib_main_t * vm, + unformat_input_t * input, vlib_cli_command_t * cmd) +{ + u8 *dns_reply_data = 0; + int verbose = 0; + int reply_set = 0; + + while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT) + { + if (unformat (input, "verbose %d", &verbose)) + ; + else if (unformat (input, "verbose")) + verbose = 1; + else if (unformat (input, "%U", unformat_dns_reply, &dns_reply_data)) + reply_set = 1; + else + return clib_error_return (0, "unknown input `%U'", + format_unformat_error, input); + } + + if (reply_set == 0) + return clib_error_return (0, "dns data not set..."); + + vlib_cli_output (vm, "%U", format_dns_reply, dns_reply_data, verbose); + + vec_free (dns_reply_data); + + return 0; +} + +/* *INDENT-OFF* */ +VLIB_CLI_COMMAND (test_dns_unfmt_command) = +{ + .path = "test dns unformat", + .short_help = "test dns unformat [ip4][ip6]", + .function = test_dns_unfmt_command_fn, +}; +/* *INDENT-ON* */ +#endif + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ diff --git a/src/vnet/dns/dns.h b/src/vnet/dns/dns.h new file mode 100644 index 00000000000..5da26156f6c --- /dev/null +++ b/src/vnet/dns/dns.h @@ -0,0 +1,149 @@ +/* + * Copyright (c) 2017 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. + */ + +#ifndef included_dns_h +#define included_dns_h + +#include +#include +#include + +#include +#include +#include + +typedef struct +{ + /** flags */ + volatile u8 flags; + + /** The name in "normal human being" notation, e.g. www.foobar.com */ + u8 *name; + + /** Expiration time */ + f64 expiration_time; + + /** Cached dns request, for sending retries */ + u8 *dns_request; + + /** Retry parameters */ + int retry_count; + int server_rotor; + int server_af; + f64 retry_timer; + + /** Cached dns response */ + u8 *dns_response; + + /** Clients awaiting responses */ + u32 *api_clients_to_notify; + u32 *api_client_contexts; + ip4_address_t *ip4_peers_to_notify; + ip6_address_t *ip6_peers_to_notify; +} dns_cache_entry_t; + +#define DNS_CACHE_ENTRY_FLAG_VALID (1<<0) /**< we have Actual Data */ +#define DNS_CACHE_ENTRY_FLAG_STATIC (1<<1) /**< static entry */ + +#define DNS_RETRIES_PER_SERVER 3 + +#define DNS_RESOLVER_EVENT_RESOLVED 1 +#define DNS_RESOLVER_EVENT_PENDING 2 + + +typedef struct +{ + /** Pool of cache entries */ + dns_cache_entry_t *entries; + + /** Pool indices of unresolved entries */ + u32 *unresolved_entries; + + /** Find cached record by name */ + uword *cache_entry_by_name; + uword *cache_lock; + + /** enable / disable flag */ + int is_enabled; + + /** upstream name servers, e.g. 8.8.8.8 */ + ip4_address_t *ip4_name_servers; + ip6_address_t *ip6_name_servers; + + /** config parameters */ + u32 name_cache_size; + u32 max_ttl_in_seconds; + u32 random_seed; + + /* convenience */ + vlib_main_t *vlib_main; + vnet_main_t *vnet_main; +} dns_main_t; + +extern dns_main_t dns_main; + +extern vlib_node_registration_t dns46_reply_node; +extern vlib_node_registration_t dns_resolver_node; + +#define foreach_dns46_reply_error \ +_(PROCESSED, "DNS reply pkts processed") \ +_(NO_ELT, "No DNS pool element") \ +_(FORMAT_ERROR, "DNS format errors") \ +_(TEST_DROP, "DNS reply pkt dropped for test purposes") + +typedef enum +{ +#define _(sym,str) DNS46_REPLY_ERROR_##sym, + foreach_dns46_reply_error +#undef _ + DNS46_REPLY_N_ERROR, +} dns46_reply_error_t; + +void vnet_send_dns_request (dns_main_t * dm, dns_cache_entry_t * ep); +int vnet_dns_cname_indirection_nolock (dns_main_t * dm, + dns_cache_entry_t * ep, u8 * reply); +int vnet_dns_delete_entry_by_index_nolock (dns_main_t * dm, u32 index); + +format_function_t format_dns_reply; + +static inline void +dns_cache_lock (dns_main_t * dm) +{ + if (dm->cache_lock) + { + while (__sync_lock_test_and_set (dm->cache_lock, 1)) + ; + } +} + +static inline void +dns_cache_unlock (dns_main_t * dm) +{ + if (dm->cache_lock) + { + CLIB_MEMORY_BARRIER (); + *dm->cache_lock = 0; + } +} + +#endif /* included_dns_h */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ diff --git a/src/vnet/dns/dns_packet.h b/src/vnet/dns/dns_packet.h new file mode 100644 index 00000000000..e0ea8fe2706 --- /dev/null +++ b/src/vnet/dns/dns_packet.h @@ -0,0 +1,154 @@ +/* + * 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. + */ + +#ifndef included_dns_packet_h +#define included_dns_packet_h + +/** + * DNS packet header format + */ + +/* *INDENT-OFF* */ +typedef CLIB_PACKED (struct { + u16 id; /**< transaction ID */ + u16 flags; /**< flags */ + u16 qdcount; /**< number of questions */ + u16 anscount; /**< number of answers */ + u16 nscount; /**< number of name servers */ + u16 arcount; /**< number of additional records */ +}) dns_header_t; +/* *INDENT-ON* */ + +#define DNS_RCODE_MASK (0xf) +#define DNS_RCODE_NO_ERROR 0 +#define DNS_RCODE_FORMAT_ERROR 1 +#define DNS_RCODE_SERVER_FAILURE 2 +#define DNS_RCODE_NAME_ERROR 3 +#define DNS_RCODE_NOT_IMPLEMENTED 4 +#define DNS_RCODE_REFUSED 5 + +#define DNS_RA (1<<7) /**< recursion available */ +#define DNS_RD (1<<8) /**< recursion desired */ +#define DNS_TC (1<<9) /**< truncation */ +#define DNS_AA (1<<10) /**< authoritative answer */ +#define DNS_OPCODE_MASK (0xf<<11) /**< opcode mask */ +#define DNS_OPCODE_QUERY (0<<11) /**< standard query */ +#define DNS_OPCODE_IQUERY (1<<11) /**< inverse query (deprecated) */ +#define DNS_OPCODE_STATUS (2<<11) /**< server status */ +#define DNS_QR (1<<15) /**< query=0, response=1 */ + + +/* + * Note: in DNS-land, www.foobar.com is encoded as three "labels," + * each of which amount to a 1 octet length followed by up to 63 + * octets of name. Don't forget to add a "null root label" after the last + * real one, or the poor slob trying to parse the name will have + * no chance whatsoever. + * + * All RRs have the same top level format shown below: + * + * 1 1 1 1 1 1 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | | + * / / + * / NAME / + * | | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | TYPE | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | CLASS | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | TTL | + * | | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | RDLENGTH | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| + * / RDATA / + * / / + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * + * + * DNS "questions" have the following format: + * + * 1 1 1 1 1 1 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | | + * / QNAME / + * / / + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | QTYPE | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | QCLASS | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + */ + +/** + * DNS "question" fixed header. + */ +/* *INDENT-OFF* */ +typedef CLIB_PACKED (struct { + u16 type; /**< record type requested */ + u16 class; /**< class, 1 = internet */ +}) dns_query_t; +/* *INDENT-ON* */ + +/** + * DNS RR fixed header. + */ +/* *INDENT-OFF* */ +typedef CLIB_PACKED (struct { + u16 type; /**< record type */ + u16 class; /**< class, 1 = internet */ + u32 ttl; /**< time to live, in seconds */ + u16 rdlength; + /**< length of r */ + u8 rdata[0]; +}) dns_rr_t; +/* *INDENT-ON* */ + +/* + * There are quite a number of DNS record types + * Feel free to add as needed + */ +#define foreach_dns_type \ +_(A, 1) /**< ip4 host address */ \ +_(AAAA, 28) /**< ip6 host address */ \ +_(ALL, 255) /**< all available data */ \ +_(TEXT, 16) /**< a text string */ \ +_(NAMESERVER, 2) /**< a nameserver */ \ +_(CNAME, 5) /**< a CNAME (alias) */ \ +_(MAIL_EXCHANGE, 15) /**< a mail exchange */ + +typedef enum +{ +#define _(name,value) DNS_TYPE_##name = value, + foreach_dns_type +#undef _ +} dns_type_t; + +#define DNS_CLASS_IN 1 /**< The Internet */ + + +#endif /* included_dns_packet_h */ + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ diff --git a/src/vnet/dns/reply_node.c b/src/vnet/dns/reply_node.c new file mode 100644 index 00000000000..e045ba8cda4 --- /dev/null +++ b/src/vnet/dns/reply_node.c @@ -0,0 +1,214 @@ +/* + * Copyright (c) 2017 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 + +vlib_node_registration_t dns46_reply_node; + +typedef struct +{ + u32 pool_index; + u32 disposition; +} dns46_reply_trace_t; + +/* packet trace format function */ +static u8 * +format_dns46_reply_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 *); + dns46_reply_trace_t *t = va_arg (*args, dns46_reply_trace_t *); + + s = format (s, "DNS46_REPLY: pool index %d, disposition %d", + t->pool_index, t->disposition); + return s; +} + +vlib_node_registration_t dns46_reply_node; + +static char *dns46_reply_error_strings[] = { +#define _(sym,string) string, + foreach_dns46_reply_error +#undef _ +}; + +typedef enum +{ + DNS46_REPLY_NEXT_DROP, + DNS46_REPLY_N_NEXT, +} dns46_reply_next_t; + +static uword +dns46_reply_node_fn (vlib_main_t * vm, + vlib_node_runtime_t * node, vlib_frame_t * frame) +{ + u32 n_left_from, *from, *to_next; + dns46_reply_next_t next_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); + +#if 0 + while (n_left_from >= 4 && n_left_to_next >= 2) + { + u32 next0 = DNS46_REPLY_NEXT_INTERFACE_OUTPUT; + u32 next1 = DNS46_REPLY_NEXT_INTERFACE_OUTPUT; + u32 sw_if_index0, sw_if_index1; + u8 tmp0[6], tmp1[6]; + ethernet_header_t *en0, *en1; + u32 bi0, bi1; + vlib_buffer_t *b0, *b1; + + /* 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); + + /* $$$$$ End of processing 2 x packets $$$$$ */ + + if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE))) + { + if (b0->flags & VLIB_BUFFER_IS_TRACED) + { + dns46_reply_trace_t *t = + vlib_add_trace (vm, node, b0, sizeof (*t)); + t->sw_if_index = sw_if_index0; + t->next_index = next0; + } + if (b1->flags & VLIB_BUFFER_IS_TRACED) + { + dns46_reply_trace_t *t = + vlib_add_trace (vm, node, b1, sizeof (*t)); + t->sw_if_index = sw_if_index1; + t->next_index = next1; + } + } + + /* 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); + } +#endif + + while (n_left_from > 0 && n_left_to_next > 0) + { + u32 bi0; + vlib_buffer_t *b0; + u32 next0 = DNS46_REPLY_NEXT_DROP; + dns_header_t *d0; + u32 pool_index0; + u32 error0; + u8 *resp0 = 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); + d0 = vlib_buffer_get_current (b0); + + pool_index0 = clib_host_to_net_u16 (d0->id); + + /* Save the reply */ + vec_validate (resp0, vlib_buffer_length_in_chain (vm, b0) - 1); + clib_memcpy (resp0, d0, vlib_buffer_length_in_chain (vm, b0)); + + /* + * Deal with everything in process ctx on the main thread + */ + vlib_process_signal_event_mt (vm, dns_resolver_node.index, + DNS_RESOLVER_EVENT_RESOLVED, + (uword) resp0); + error0 = DNS46_REPLY_ERROR_PROCESSED; + + b0->error = node->errors[error0]; + + if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) + && (b0->flags & VLIB_BUFFER_IS_TRACED))) + { + dns46_reply_trace_t *t = + vlib_add_trace (vm, node, b0, sizeof (*t)); + t->disposition = error0; + t->pool_index = pool_index0; + } + + /* 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); + } + + return frame->n_vectors; +} + +VLIB_REGISTER_NODE (dns46_reply_node) = +{ + .function = dns46_reply_node_fn,.name = "dns46_reply",.vector_size = + sizeof (u32),.format_trace = format_dns46_reply_trace,.type = + VLIB_NODE_TYPE_INTERNAL,.n_errors = + ARRAY_LEN (dns46_reply_error_strings),.error_strings = + dns46_reply_error_strings,.n_next_nodes = DNS46_REPLY_N_NEXT, + /* edit / add dispositions here */ + .next_nodes = + { + [DNS46_REPLY_NEXT_DROP] = "error-drop",} +,}; + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ diff --git a/src/vnet/dns/resolver_process.c b/src/vnet/dns/resolver_process.c new file mode 100644 index 00000000000..91e5cef1bcd --- /dev/null +++ b/src/vnet/dns/resolver_process.c @@ -0,0 +1,243 @@ +/* + * Copyright (c) 2017 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 + +#define vl_typedefs /* define message structures */ +#include +#undef vl_typedefs + +#define vl_endianfun /* define message structures */ +#include +#undef vl_endianfun + +/* instantiate all the print functions we know about */ +#define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__) +#define vl_printfun +#include +#undef vl_printfun + +#include + +vlib_node_registration_t dns_resolver_node; + +extern int +vnet_dns_response_to_reply (u8 * response, + vl_api_dns_resolve_name_reply_t * rmp, + u32 * min_ttlp); + +static void +resolve_event (dns_main_t * dm, f64 now, u8 * reply) +{ + vlib_main_t *vm = dm->vlib_main; + dns_header_t *d; + u32 pool_index; + dns_cache_entry_t *ep; + u32 min_ttl; + u16 flags; + u16 rcode; + int i; + int rv = 0; + + d = (dns_header_t *) reply; + flags = clib_net_to_host_u16 (d->flags); + rcode = flags & DNS_RCODE_MASK; + + /* $$$ u16 limits cache to 65K entries, fix later multiple dst ports */ + pool_index = clib_net_to_host_u16 (d->id); + dns_cache_lock (dm); + + if (pool_is_free_index (dm->entries, pool_index)) + { + vec_free (reply); + vlib_node_increment_counter (vm, dns46_reply_node.index, + DNS46_REPLY_ERROR_NO_ELT, 1); + dns_cache_unlock (dm); + return; + } + + ep = pool_elt_at_index (dm->entries, pool_index); + + if (ep->dns_response) + vec_free (ep->dns_response); + + /* Handle [sic] recursion AKA CNAME indirection */ + if (vnet_dns_cname_indirection_nolock (dm, ep, reply)) + { + dns_cache_unlock (dm); + return; + } + + /* Save the response */ + ep->dns_response = reply; + /* Pick some sensible default. */ + ep->expiration_time = now + 600.0; + if (vec_len (ep->dns_response)) + ep->flags |= DNS_CACHE_ENTRY_FLAG_VALID; + + /* Most likely, send 1 message */ + for (i = 0; i < vec_len (ep->api_clients_to_notify); i++) + { + vl_api_registration_t *regp; + vl_api_dns_resolve_name_reply_t *rmp; + + regp = vl_api_client_index_to_registration + (ep->api_clients_to_notify[i]); + + if (regp == 0) + continue; + + rmp = vl_msg_api_alloc (sizeof (*rmp) + vec_len (ep->dns_response)); + rmp->_vl_msg_id = clib_host_to_net_u16 (VL_API_DNS_RESOLVE_NAME_REPLY); + rmp->context = ep->api_client_contexts[i]; + min_ttl = ~0; + rv = vnet_dns_response_to_reply (ep->dns_response, rmp, &min_ttl); + if (min_ttl != ~0) + ep->expiration_time = now + min_ttl; + rmp->retval = clib_host_to_net_u32 (rv); + vl_msg_api_send (regp, (u8 *) rmp); + } + vec_free (ep->api_clients_to_notify); + vec_free (ep->api_client_contexts); + + /* $$$ Add ip4/ip6 reply code */ + + for (i = 0; i < vec_len (dm->unresolved_entries); i++) + { + if (dm->unresolved_entries[i] == pool_index) + { + vec_delete (dm->unresolved_entries, 1, i); + goto found; + } + } + clib_warning ("pool index %d AWOL from unresolved vector", pool_index); + +found: + /* Deal with bogus names, server issues, etc. */ + switch (rcode) + { + default: + case DNS_RCODE_NO_ERROR: + break; + + case DNS_RCODE_SERVER_FAILURE: + case DNS_RCODE_NOT_IMPLEMENTED: + case DNS_RCODE_REFUSED: + if (ep->server_af == 0) + clib_warning ("name server %U backfire", + format_ip4_address, + dm->ip4_name_servers + ep->server_rotor); + else + clib_warning ("name server %U backfire", + format_ip6_address, + dm->ip6_name_servers + ep->server_rotor); + /* FALLTHROUGH */ + case DNS_RCODE_NAME_ERROR: + case DNS_RCODE_FORMAT_ERROR: + /* remove trash from the cache... */ + vnet_dns_delete_entry_by_index_nolock (dm, ep - dm->entries); + break; + } + + dns_cache_unlock (dm); + return; +} + +static void +retry_scan (dns_main_t * dm, f64 now) +{ + int i; + dns_cache_entry_t *ep; + + for (i = 0; i < vec_len (dm->unresolved_entries); i++) + { + dns_cache_lock (dm); + ep = pool_elt_at_index (dm->entries, dm->unresolved_entries[i]); + + ASSERT ((ep->flags & DNS_CACHE_ENTRY_FLAG_VALID) == 0); + + vnet_send_dns_request (dm, ep); + dns_cache_unlock (dm); + } +} + +static uword +dns_resolver_process (vlib_main_t * vm, + vlib_node_runtime_t * rt, vlib_frame_t * f) +{ + dns_main_t *dm = &dns_main; + f64 now; + f64 timeout = 1000.0; + uword *event_data = 0; + uword event_type; + int i; + + while (1) + { + vlib_process_wait_for_event_or_clock (vm, timeout); + + now = vlib_time_now (vm); + + event_type = vlib_process_get_events (vm, (uword **) & event_data); + + switch (event_type) + { + /* Send one of these when a resolution is pending */ + case DNS_RESOLVER_EVENT_PENDING: + timeout = 2.0; + break; + + case DNS_RESOLVER_EVENT_RESOLVED: + for (i = 0; i < vec_len (event_data); i++) + resolve_event (dm, now, (u8 *) event_data[i]); + break; + + case ~0: /* timeout */ + retry_scan (dm, now); + break; + } + vec_reset_length (event_data); + + /* No work? Back to slow timeout mode... */ + if (vec_len (dm->unresolved_entries) == 0) + timeout = 1000.0; + } + return 0; /* or not */ +} + +/* *INDENT-OFF* */ +VLIB_REGISTER_NODE (dns_resolver_node) = +{ + .function = dns_resolver_process, + .type = VLIB_NODE_TYPE_PROCESS, + .name = "dns-resolver-process", +}; +/* *INDENT-ON* */ + + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ -- cgit 1.2.3-korg