| 1 | /* |
| 2 | * QEMU DNS resolver |
| 3 | * |
| 4 | * Copyright (c) 2016 Red Hat, Inc. |
| 5 | * |
| 6 | * This library is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * This library is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with this library; if not, see <http://www.gnu.org/licenses/>. |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | #include "qemu/osdep.h" |
| 22 | #include "io/dns-resolver.h" |
| 23 | #include "qapi/clone-visitor.h" |
| 24 | #include "qapi/qapi-visit-sockets.h" |
| 25 | #include "qemu/sockets.h" |
| 26 | #include "qapi/error.h" |
| 27 | #include "qemu/cutils.h" |
| 28 | #include "qemu/module.h" |
| 29 | |
| 30 | #ifndef AI_NUMERICSERV |
| 31 | # define AI_NUMERICSERV 0 |
| 32 | #endif |
| 33 | |
| 34 | static QIODNSResolver *instance; |
| 35 | static GOnce instance_init = G_ONCE_INIT; |
| 36 | |
| 37 | static gpointer qio_dns_resolve_init_instance(gpointer unused G_GNUC_UNUSED) |
| 38 | { |
| 39 | instance = QIO_DNS_RESOLVER(object_new(TYPE_QIO_DNS_RESOLVER)); |
| 40 | return NULL; |
| 41 | } |
| 42 | |
| 43 | QIODNSResolver *qio_dns_resolver_get_instance(void) |
| 44 | { |
| 45 | g_once(&instance_init, qio_dns_resolve_init_instance, NULL); |
| 46 | return instance; |
| 47 | } |
| 48 | |
| 49 | static int qio_dns_resolver_lookup_sync_inet(QIODNSResolver *resolver, |
| 50 | SocketAddress *addr, |
| 51 | size_t *naddrs, |
| 52 | SocketAddress ***addrs, |
| 53 | Error **errp) |
| 54 | { |
| 55 | struct addrinfo ai, *res, *e; |
| 56 | InetSocketAddress *iaddr = &addr->u.inet; |
| 57 | char port[33]; |
| 58 | char uaddr[INET6_ADDRSTRLEN + 1]; |
| 59 | char uport[33]; |
| 60 | int rc; |
| 61 | Error *err = NULL; |
| 62 | size_t i; |
| 63 | |
| 64 | *naddrs = 0; |
| 65 | *addrs = NULL; |
| 66 | |
| 67 | memset(&ai, 0, sizeof(ai)); |
| 68 | ai.ai_flags = AI_PASSIVE; |
| 69 | if (iaddr->has_numeric && iaddr->numeric) { |
| 70 | ai.ai_flags |= AI_NUMERICHOST | AI_NUMERICSERV; |
| 71 | } |
| 72 | ai.ai_family = inet_ai_family_from_address(iaddr, &err); |
| 73 | ai.ai_socktype = SOCK_STREAM; |
| 74 | |
| 75 | if (err) { |
| 76 | error_propagate(errp, err); |
| 77 | return -1; |
| 78 | } |
| 79 | |
| 80 | if (iaddr->host == NULL) { |
| 81 | error_setg(errp, "host not specified"); |
| 82 | return -1; |
| 83 | } |
| 84 | if (iaddr->port != NULL) { |
| 85 | pstrcpy(port, sizeof(port), iaddr->port); |
| 86 | } else { |
| 87 | port[0] = '\0'; |
| 88 | } |
| 89 | |
| 90 | rc = getaddrinfo(strlen(iaddr->host) ? iaddr->host : NULL, |
| 91 | strlen(port) ? port : NULL, &ai, &res); |
| 92 | if (rc != 0) { |
| 93 | error_setg(errp, "address resolution failed for %s:%s: %s", |
| 94 | iaddr->host, port, gai_strerror(rc)); |
| 95 | return -1; |
| 96 | } |
| 97 | |
| 98 | for (e = res; e != NULL; e = e->ai_next) { |
| 99 | (*naddrs)++; |
| 100 | } |
| 101 | |
| 102 | *addrs = g_new0(SocketAddress *, *naddrs); |
| 103 | |
| 104 | /* create socket + bind */ |
| 105 | for (i = 0, e = res; e != NULL; i++, e = e->ai_next) { |
| 106 | SocketAddress *newaddr = g_new0(SocketAddress, 1); |
| 107 | |
| 108 | newaddr->type = SOCKET_ADDRESS_TYPE_INET; |
| 109 | |
| 110 | getnameinfo((struct sockaddr *)e->ai_addr, e->ai_addrlen, |
| 111 | uaddr, INET6_ADDRSTRLEN, uport, 32, |
| 112 | NI_NUMERICHOST | NI_NUMERICSERV); |
| 113 | |
| 114 | newaddr->u.inet = *iaddr; |
| 115 | newaddr->u.inet.host = g_strdup(uaddr), |
| 116 | newaddr->u.inet.port = g_strdup(uport), |
| 117 | newaddr->u.inet.has_numeric = true, |
| 118 | newaddr->u.inet.numeric = true, |
| 119 | |
| 120 | (*addrs)[i] = newaddr; |
| 121 | } |
| 122 | freeaddrinfo(res); |
| 123 | return 0; |
| 124 | } |
| 125 | |
| 126 | |
| 127 | static int qio_dns_resolver_lookup_sync_nop(QIODNSResolver *resolver, |
| 128 | SocketAddress *addr, |
| 129 | size_t *naddrs, |
| 130 | SocketAddress ***addrs, |
| 131 | Error **errp) |
| 132 | { |
| 133 | *naddrs = 1; |
| 134 | *addrs = g_new0(SocketAddress *, 1); |
| 135 | (*addrs)[0] = QAPI_CLONE(SocketAddress, addr); |
| 136 | |
| 137 | return 0; |
| 138 | } |
| 139 | |
| 140 | |
| 141 | int qio_dns_resolver_lookup_sync(QIODNSResolver *resolver, |
| 142 | SocketAddress *addr, |
| 143 | size_t *naddrs, |
| 144 | SocketAddress ***addrs, |
| 145 | Error **errp) |
| 146 | { |
| 147 | switch (addr->type) { |
| 148 | case SOCKET_ADDRESS_TYPE_INET: |
| 149 | return qio_dns_resolver_lookup_sync_inet(resolver, |
| 150 | addr, |
| 151 | naddrs, |
| 152 | addrs, |
| 153 | errp); |
| 154 | |
| 155 | case SOCKET_ADDRESS_TYPE_UNIX: |
| 156 | case SOCKET_ADDRESS_TYPE_VSOCK: |
| 157 | case SOCKET_ADDRESS_TYPE_FD: |
| 158 | return qio_dns_resolver_lookup_sync_nop(resolver, |
| 159 | addr, |
| 160 | naddrs, |
| 161 | addrs, |
| 162 | errp); |
| 163 | |
| 164 | default: |
| 165 | abort(); |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | |
| 170 | struct QIODNSResolverLookupData { |
| 171 | SocketAddress *addr; |
| 172 | SocketAddress **addrs; |
| 173 | size_t naddrs; |
| 174 | }; |
| 175 | |
| 176 | |
| 177 | static void qio_dns_resolver_lookup_data_free(gpointer opaque) |
| 178 | { |
| 179 | struct QIODNSResolverLookupData *data = opaque; |
| 180 | size_t i; |
| 181 | |
| 182 | qapi_free_SocketAddress(data->addr); |
| 183 | for (i = 0; i < data->naddrs; i++) { |
| 184 | qapi_free_SocketAddress(data->addrs[i]); |
| 185 | } |
| 186 | |
| 187 | g_free(data->addrs); |
| 188 | g_free(data); |
| 189 | } |
| 190 | |
| 191 | |
| 192 | static void qio_dns_resolver_lookup_worker(QIOTask *task, |
| 193 | gpointer opaque) |
| 194 | { |
| 195 | QIODNSResolver *resolver = QIO_DNS_RESOLVER(qio_task_get_source(task)); |
| 196 | struct QIODNSResolverLookupData *data = opaque; |
| 197 | Error *err = NULL; |
| 198 | |
| 199 | qio_dns_resolver_lookup_sync(resolver, |
| 200 | data->addr, |
| 201 | &data->naddrs, |
| 202 | &data->addrs, |
| 203 | &err); |
| 204 | if (err) { |
| 205 | qio_task_set_error(task, err); |
| 206 | } else { |
| 207 | qio_task_set_result_pointer(task, opaque, NULL); |
| 208 | } |
| 209 | |
| 210 | object_unref(OBJECT(resolver)); |
| 211 | } |
| 212 | |
| 213 | |
| 214 | void qio_dns_resolver_lookup_async(QIODNSResolver *resolver, |
| 215 | SocketAddress *addr, |
| 216 | QIOTaskFunc func, |
| 217 | gpointer opaque, |
| 218 | GDestroyNotify notify) |
| 219 | { |
| 220 | QIOTask *task; |
| 221 | struct QIODNSResolverLookupData *data = |
| 222 | g_new0(struct QIODNSResolverLookupData, 1); |
| 223 | |
| 224 | data->addr = QAPI_CLONE(SocketAddress, addr); |
| 225 | |
| 226 | task = qio_task_new(OBJECT(resolver), func, opaque, notify); |
| 227 | |
| 228 | qio_task_run_in_thread(task, |
| 229 | qio_dns_resolver_lookup_worker, |
| 230 | data, |
| 231 | qio_dns_resolver_lookup_data_free, |
| 232 | NULL); |
| 233 | } |
| 234 | |
| 235 | |
| 236 | void qio_dns_resolver_lookup_result(QIODNSResolver *resolver, |
| 237 | QIOTask *task, |
| 238 | size_t *naddrs, |
| 239 | SocketAddress ***addrs) |
| 240 | { |
| 241 | struct QIODNSResolverLookupData *data = |
| 242 | qio_task_get_result_pointer(task); |
| 243 | size_t i; |
| 244 | |
| 245 | *naddrs = 0; |
| 246 | *addrs = NULL; |
| 247 | if (!data) { |
| 248 | return; |
| 249 | } |
| 250 | |
| 251 | *naddrs = data->naddrs; |
| 252 | *addrs = g_new0(SocketAddress *, data->naddrs); |
| 253 | for (i = 0; i < data->naddrs; i++) { |
| 254 | (*addrs)[i] = QAPI_CLONE(SocketAddress, data->addrs[i]); |
| 255 | } |
| 256 | } |
| 257 | |
| 258 | |
| 259 | static const TypeInfo qio_dns_resolver_info = { |
| 260 | .parent = TYPE_OBJECT, |
| 261 | .name = TYPE_QIO_DNS_RESOLVER, |
| 262 | .instance_size = sizeof(QIODNSResolver), |
| 263 | }; |
| 264 | |
| 265 | |
| 266 | static void qio_dns_resolver_register_types(void) |
| 267 | { |
| 268 | type_register_static(&qio_dns_resolver_info); |
| 269 | } |
| 270 | |
| 271 | |
| 272 | type_init(qio_dns_resolver_register_types); |