src/IOHandler/IODNSEngine_cares.c

   1 /* IODNSEngine_cares.c - IOMultiplexer
   2  * Copyright (C) 2014  Philipp Kreil (pk910)
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  16  */
  17 #define _IOHandler_internals
  18 #include "IOInternal.h"
  19 #include "IOHandler.h"
  20 #include "IODNSLookup.h"
  21 #include "IOLog.h"
  22 #include "IOSockets.h"
  23 #include "IOTimer.h"
  24
  25 #ifdef HAVE_ARES_H
  26 #include <ares.h>
  27 #include <string.h>
  28 #include <sys/time.h>
  29 #ifdef WIN32
  30 #define _WIN32_WINNT 0x501
  31 #include <windows.h>
  32 #include <winsock2.h>
  33 #elif defined HAVE_SYS_SELECT_H
  34 #include <sys/select.h>
  35 #include <netdb.h>
  36 #include <arpa/inet.h>
  37 #endif
  38
  39 #include "compat/inet.h"
  40
  41 struct dnsengine_cares_socket {
  42         struct _IOSocket *iosock;
  43         int want_read : 1;
  44         int want_write : 1;
  45 };
  46
  47 struct dnsengine_cares_query {
  48         int query_count;
  49         int query_successful;
  50         struct _IODNSQuery *iodns;
  51 };
  52
  53 static IOTIMER_CALLBACK(dnsengine_cares_timer_callback);
  54
  55 static ares_channel dnsengine_cares_channel;
  56 static struct dnsengine_cares_socket dnsengine_cares_sockets[ARES_GETSOCK_MAXNUM];
  57 static struct IOTimerDescriptor *dnsengine_cares_timer = NULL;
  58
  59 static int dnsengine_cares_init() {
  60         int res;
  61
  62         // zero dnsengine_cares_sockets array
  63         memset(dnsengine_cares_sockets, 0, sizeof(*dnsengine_cares_sockets) * ARES_GETSOCK_MAXNUM);
  64
  65         // initialize cares
  66         if((res = ares_init(&dnsengine_cares_channel)) != ARES_SUCCESS) {
  67                 iolog_trigger(IOLOG_ERROR, "Failed to initialize c-ares in %s:%d", __FILE__, __LINE__);
  68                 return 0;
  69         }
  70         return 1;
  71 }
  72
  73 static void dnsengine_cares_update_sockets() {
  74         int ares_socks[ARES_GETSOCK_MAXNUM];
  75         memset(ares_socks, 0, sizeof(*ares_socks) * ARES_GETSOCK_MAXNUM);
  76         int sockreqs = ares_getsock(dnsengine_cares_channel, ares_socks, ARES_GETSOCK_MAXNUM);
  77         int i, j, sockid, newsock, updatesock;
  78         struct _IOSocket *iosock;
  79
  80         //unregister "old" sockets
  81         for(i = 0; i < ARES_GETSOCK_MAXNUM; i++) {
  82                 if(!dnsengine_cares_sockets[i].iosock)
  83                         continue;
  84
  85                 //search matching ares_socks
  86                 sockid = -1;
  87                 for(j = 0; j < ARES_GETSOCK_MAXNUM; j++) {
  88                         if(dnsengine_cares_sockets[i].iosock->fd == ares_socks[j]) {
  89                                 sockid = j;
  90                                 break;
  91                         }
  92                 }
  93                 if(sockid == -1) {
  94                         //unregister socket
  95                         _free_socket(dnsengine_cares_sockets[i].iosock);
  96                         dnsengine_cares_sockets[i].iosock = NULL;
  97                 }
  98         }
  99
 100         //register new / update existing sockets
 101         for(i = 0; i < ARES_GETSOCK_MAXNUM; i++) {
 102                 if(!ares_socks[i])
 103                         break;
 104
 105                 //search matching dnsengine_cares_socket
 106                 sockid = -1;
 107                 for(j = 0; j < ARES_GETSOCK_MAXNUM; j++) {
 108                         if(dnsengine_cares_sockets[j].iosock && dnsengine_cares_sockets[j].iosock->fd == ares_socks[i]) {
 109                                 sockid = j;
 110                                 break;
 111                         }
 112                 }
 113
 114                 if(sockid == -1) {
 115                         //append new socket
 116                         for(j = 0; j < ARES_GETSOCK_MAXNUM; j++) {
 117                                 if(!dnsengine_cares_sockets[j].iosock) {
 118                                         sockid = j;
 119                                         break;
 120                                 }
 121                         }
 122                         if(sockid == -1) {
 123                                 iolog_trigger(IOLOG_ERROR, "Error in dnsengine_cares_update_sockets: could not find free dnsengine_cares_socket in %s:%d", __FILE__, __LINE__);
 124                                 continue;
 125                         }
 126                         iosock = _create_socket();
 127                         if(!iosock)
 128                                 continue;
 129
 130                         //set up iosock
 131                         iosock->socket_flags |= IOSOCKETFLAG_PARENT_DNSENGINE | IOSOCKETFLAG_OVERRIDE_WANT_RW;
 132                         iosock->fd = ares_socks[i];
 133                         dnsengine_cares_sockets[sockid].iosock = iosock;
 134                         dnsengine_cares_sockets[sockid].want_read = 0;
 135                         dnsengine_cares_sockets[sockid].want_write = 0;
 136
 137                         newsock = 1;
 138                 } else
 139                         newsock = 0;
 140
 141                 updatesock = 0;
 142                 if(dnsengine_cares_sockets[sockid].want_read ^ ARES_GETSOCK_READABLE(sockreqs, i)) {
 143                         if(ARES_GETSOCK_READABLE(sockreqs, i)) {
 144                                 dnsengine_cares_sockets[sockid].iosock->socket_flags |= IOSOCKETFLAG_OVERRIDE_WANT_R;
 145                                 dnsengine_cares_sockets[sockid].want_read = 1;
 146                         } else {
 147                                 dnsengine_cares_sockets[sockid].iosock->socket_flags &= ~IOSOCKETFLAG_OVERRIDE_WANT_R;
 148                                 dnsengine_cares_sockets[sockid].want_read = 0;
 149                         }
 150                         updatesock = 1;
 151                 }
 152                 if(dnsengine_cares_sockets[sockid].want_write ^ ARES_GETSOCK_WRITABLE(sockreqs, i)) {
 153                         if(ARES_GETSOCK_WRITABLE(sockreqs, i)) {
 154                                 dnsengine_cares_sockets[sockid].iosock->socket_flags |= IOSOCKETFLAG_OVERRIDE_WANT_W;
 155                                 dnsengine_cares_sockets[sockid].want_write = 1;
 156                         } else {
 157                                 dnsengine_cares_sockets[sockid].iosock->socket_flags &= ~IOSOCKETFLAG_OVERRIDE_WANT_W;
 158                                 dnsengine_cares_sockets[sockid].want_write = 0;
 159                         }
 160                         updatesock = 1;
 161                 }
 162                 if(updatesock || newsock) {
 163                         if(newsock)
 164                                 iosocket_activate(dnsengine_cares_sockets[sockid].iosock);
 165                         else
 166                                 iosocket_update(dnsengine_cares_sockets[sockid].iosock);
 167                 }
 168         }
 169 }
 170
 171 static void dnsengine_cares_update_timeout() {
 172         struct timeval timeout, now;
 173         timeout.tv_sec = 60;
 174         timeout.tv_usec = 0;
 175         ares_timeout(dnsengine_cares_channel, &timeout, &timeout);
 176
 177         gettimeofday(&now, NULL);
 178         timeout.tv_sec += now.tv_sec;
 179         timeout.tv_usec += now.tv_usec;
 180         if(timeout.tv_usec > 1000000) {
 181                 timeout.tv_sec += 1;
 182                 timeout.tv_usec -= 1000000;
 183         }
 184
 185         if(dnsengine_cares_timer)
 186                 iotimer_set_timeout(dnsengine_cares_timer, &timeout);
 187         else {
 188                 dnsengine_cares_timer = iotimer_create(&timeout);
 189                 iotimer_set_callback(dnsengine_cares_timer, dnsengine_cares_timer_callback);
 190                 iotimer_start(dnsengine_cares_timer);
 191         }
 192 }
 193
 194 static IOTIMER_CALLBACK(dnsengine_cares_timer_callback) {
 195         dnsengine_cares_timer = NULL;
 196         ares_process_fd(dnsengine_cares_channel, ARES_SOCKET_BAD, ARES_SOCKET_BAD);
 197         dnsengine_cares_update_timeout();
 198         dnsengine_cares_update_sockets();
 199 }
 200
 201 static void dnsengine_cares_socket_callback(struct _IOSocket *iosock, int wantread, int wantwrite) {
 202         int socketfd = iosock->fd;
 203         ares_process_fd(dnsengine_cares_channel, (wantread ? socketfd : ARES_SOCKET_BAD), (wantread ? socketfd : ARES_SOCKET_BAD));
 204         dnsengine_cares_update_timeout();
 205         dnsengine_cares_update_sockets();
 206 }
 207
 208 static void dnsengine_cares_stop() {
 209         if(dnsengine_cares_timer)
 210                 iotimer_destroy(dnsengine_cares_timer);
 211 }
 212
 213
 214 static void dnsengine_cares_callback(void *arg, int status, int timeouts, struct hostent *host) {
 215         struct dnsengine_cares_query *query = arg;
 216         struct _IODNSQuery *iodns = query->iodns;
 217         query->query_count--;
 218         if(iodns) {
 219                 if(!(iodns->flags & IODNSFLAG_RUNNING)) {
 220                         // query stopped
 221                         query->iodns = NULL;
 222                         iodns = NULL;
 223                         iodns_free_result(iodns->result);
 224                         _free_dnsquery(iodns);
 225                 }
 226                 if(iodns && status == ARES_SUCCESS) {
 227                         if((iodns->type & IODNS_FORWARD)) {
 228                                 char **h_addr;
 229                                 for(h_addr = host->h_addr_list; *h_addr; h_addr++) {
 230                                         struct IODNSResult *dnsresult = malloc(sizeof(*dnsresult));
 231                                         if(!dnsresult) {
 232                                                 iolog_trigger(IOLOG_ERROR, "Failed to allocate memory for IODNSResult in %s:%d", __FILE__, __LINE__);
 233                                                 goto dnsengine_cares_callback_finally;
 234                                         }
 235
 236                                         int sockaddrlen;
 237                                         if(host->h_addrtype == AF_INET) {
 238                                                 dnsresult->type = IODNS_RECORD_A;
 239                                                 sockaddrlen = sizeof(struct sockaddr_in);
 240                                         } else {
 241                                                 dnsresult->type = IODNS_RECORD_AAAA;
 242                                                 sockaddrlen = sizeof(struct sockaddr_in6);
 243                                         }
 244                                         dnsresult->result.addr.addresslen = sockaddrlen;
 245                                         dnsresult->result.addr.address = malloc(sockaddrlen);
 246                                         if(!dnsresult->result.addr.address) {
 247                                                 iolog_trigger(IOLOG_ERROR, "Failed to allocate memory for sockaddr in %s:%d", __FILE__, __LINE__);
 248                                                 goto dnsengine_cares_callback_finally;
 249                                         }
 250                                         void *target = (host->h_addrtype == AF_INET ? ((void *) &((struct sockaddr_in *)dnsresult->result.addr.address)->sin_addr) : ((void *) &((struct sockaddr_in6 *)dnsresult->result.addr.address)->sin6_addr));
 251                                         memcpy(target, *h_addr, host->h_length);
 252
 253                                         dnsresult->result.addr.address->sa_family = host->h_addrtype;
 254                                         if(host->h_addrtype == AF_INET) {
 255                                                 char str[INET_ADDRSTRLEN];
 256                                                 inet_ntop( AF_INET, &((struct sockaddr_in *)dnsresult->result.addr.address)->sin_addr, str, INET_ADDRSTRLEN );
 257                                                 iolog_trigger(IOLOG_DEBUG, "Resolved %s to (A): %s", iodns->request.host, str);
 258                                         } else {
 259                                                 char str[INET6_ADDRSTRLEN];
 260                                                 inet_ntop( AF_INET6, &((struct sockaddr_in6 *)dnsresult->result.addr.address)->sin6_addr, str, INET6_ADDRSTRLEN );
 261                                                 iolog_trigger(IOLOG_DEBUG, "Resolved %s to (AAAA): %s", iodns->request.host, str);
 262                                         }
 263
 264                                         dnsresult->next = iodns->result;
 265                                         iodns->result = dnsresult;
 266                                 }
 267
 268                         } else if((iodns->type & IODNS_REVERSE)) {
 269                                 struct IODNSResult *dnsresult = malloc(sizeof(*dnsresult));
 270                                 if(!dnsresult) {
 271                                         iolog_trigger(IOLOG_ERROR, "Failed to allocate memory for IODNSResult in %s:%d", __FILE__, __LINE__);
 272                                         goto dnsengine_cares_callback_finally;
 273                                 }
 274
 275                                 dnsresult->type = IODNS_RECORD_PTR;
 276                                 dnsresult->result.host = strdup(host->h_name);
 277                                 if(!dnsresult->result.host) {
 278                                         iolog_trigger(IOLOG_ERROR, "Failed to duplicate h_name string for IODNSResult in %s:%d", __FILE__, __LINE__);
 279                                         goto dnsengine_cares_callback_finally;
 280                                 }
 281
 282                                 dnsresult->next = iodns->result;
 283                                 iodns->result = dnsresult;
 284                         }
 285
 286                         query->query_successful++;
 287                 }
 288         }
 289         dnsengine_cares_callback_finally:
 290         if(query->query_count <= 0) {
 291                 if(iodns) {
 292                         iodns->flags &= ~(IODNSFLAG_PROCESSING | IODNSFLAG_RUNNING);
 293                         iodns_event_callback(iodns, (query->query_successful ? IODNSEVENT_SUCCESS : IODNSEVENT_FAILED));
 294                 }
 295                 free(query);
 296         }
 297 }
 298
 299 static void dnsengine_cares_add(struct _IODNSQuery *iodns) {
 300         struct dnsengine_cares_query *query = malloc(sizeof(*query));
 301         if(!query) {
 302                 iolog_trigger(IOLOG_ERROR, "Failed to allocate memory for dnsengine_cares_query in %s:%d", __FILE__, __LINE__);
 303                 iodns_event_callback(iodns, IODNSEVENT_FAILED);
 304                 return;
 305         }
 306         iodns->query = query;
 307         query->query_count = 0;
 308         query->query_successful = 0;
 309         query->iodns = iodns;
 310         iodns->flags |= IODNSFLAG_PROCESSING;
 311         if((iodns->type & IODNS_FORWARD)) {
 312                 if((iodns->type & IODNS_RECORD_A)) {
 313                         query->query_count++;
 314                         ares_gethostbyname(dnsengine_cares_channel, iodns->request.host, AF_INET, dnsengine_cares_callback, query);
 315                 }
 316                 if((iodns->type & IODNS_RECORD_AAAA)) {
 317                         query->query_count++;
 318                         ares_gethostbyname(dnsengine_cares_channel, iodns->request.host, AF_INET6, dnsengine_cares_callback, query);
 319                 }
 320         } else if((iodns->type & IODNS_REVERSE)) {
 321                 query->query_count++;
 322                 struct sockaddr *addr = iodns->request.addr.address;
 323                 if(addr->sa_family == AF_INET) {
 324                         struct sockaddr_in *addr4 = (struct sockaddr_in *) iodns->request.addr.address;
 325                         ares_gethostbyaddr(dnsengine_cares_channel, &addr4->sin_addr, sizeof(addr4->sin_addr), addr->sa_family, dnsengine_cares_callback, query);
 326                 } else {
 327                         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)iodns->request.addr.address;
 328                         ares_gethostbyaddr(dnsengine_cares_channel, &addr6->sin6_addr, sizeof(addr6->sin6_addr), addr->sa_family, dnsengine_cares_callback, query);
 329                 }
 330         }
 331         dnsengine_cares_update_timeout();
 332         dnsengine_cares_update_sockets();
 333 }
 334
 335 static void dnsengine_cares_remove(struct _IODNSQuery *iodns) {
 336         /* empty */
 337 }
 338
 339 static void dnsengine_cares_loop() {
 340         /* empty */
 341 }
 342
 343 struct IODNSEngine dnsengine_cares = {
 344         .name = "c-ares",
 345         .init = dnsengine_cares_init,
 346         .stop = dnsengine_cares_stop,
 347         .add = dnsengine_cares_add,
 348         .remove = dnsengine_cares_remove,
 349         .loop = dnsengine_cares_loop,
 350         .socket_callback = dnsengine_cares_socket_callback,
 351 };
 352
 353 #else
 354
 355 struct IODNSEngine dnsengine_cares = {
 356         .name = "c-ares",
 357         .init = NULL,
 358         .stop = NULL,
 359         .add = NULL,
 360         .remove = NULL,
 361         .loop = NULL,
 362         .socket_callback = NULL,
 363 };
 364
 365 #endif