src/resolver.c

   1 /* libmpdclient
   2    (c) 2008 Max Kellermann <max@duempel.org>
   3    This project's homepage is: http://www.musicpd.org
   4
   5    Redistribution and use in source and binary forms, with or without
   6    modification, are permitted provided that the following conditions
   7    are met:
   8
   9    - Redistributions of source code must retain the above copyright
  10    notice, this list of conditions and the following disclaimer.
  11
  12    - Redistributions in binary form must reproduce the above copyright
  13    notice, this list of conditions and the following disclaimer in the
  14    documentation and/or other materials provided with the distribution.
  15
  16    - Neither the name of the Music Player Daemon nor the names of its
  17    contributors may be used to endorse or promote products derived from
  18    this software without specific prior written permission.
  19
  20    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  23    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
  24    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  25    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  26    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  27    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  28    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  29    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  30    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31 */
  32
  33 #include "resolver.h"
  34
  35 #include <netdb.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39
  40 #ifdef WIN32
  41 #  include <ws2tcpip.h>
  42 #  include <winsock.h>
  43 #else
  44 #  include <netinet/in.h>
  45 #  include <arpa/inet.h>
  46 #  include <sys/socket.h>
  47 #  include <sys/un.h>
  48 #  include <netdb.h>
  49 #endif
  50
  51 #ifndef MPD_NO_GAI
  52 #  ifdef AI_ADDRCONFIG
  53 #    define MPD_HAVE_GAI
  54 #  endif
  55 #endif
  56
  57 struct resolver {
  58         enum {
  59                 TYPE_ZERO, TYPE_ONE, TYPE_ANY
  60         } type;
  61
  62 #ifdef MPD_HAVE_GAI
  63         struct addrinfo *ai;
  64         const struct addrinfo *next;
  65 #else
  66         struct sockaddr_in sin;
  67 #endif
  68
  69         struct resolver_address current;
  70
  71 #ifndef WIN32
  72         struct sockaddr_un saun;
  73 #endif
  74 };
  75
  76 struct resolver *
  77 resolver_new(const char *host, int port)
  78 {
  79         struct resolver *resolver;
  80
  81         resolver = malloc(sizeof(*resolver));
  82         if (resolver == NULL)
  83                 return NULL;
  84
  85 #ifndef WIN32
  86         if (host[0] == '/') {
  87                 size_t path_length = strlen(host);
  88                 if (path_length >= sizeof(resolver->saun.sun_path)) {
  89                         free(resolver);
  90                         return NULL;
  91                 }
  92
  93                 resolver->saun.sun_family = AF_UNIX;
  94                 memcpy(resolver->saun.sun_path, host, path_length + 1);
  95
  96                 resolver->current.family = PF_UNIX;
  97                 resolver->current.protocol = 0;
  98                 resolver->current.addrlen = sizeof(resolver->saun);
  99                 resolver->current.addr = (const struct sockaddr *)&resolver->saun;
 100                 resolver->type = TYPE_ONE;
 101         } else {
 102 #endif
 103 #ifdef MPD_HAVE_GAI
 104                 struct addrinfo hints;
 105                 char service[20];
 106                 int ret;
 107
 108                 memset(&hints, 0, sizeof(hints));
 109                 hints.ai_flags = AI_ADDRCONFIG;
 110                 hints.ai_family = PF_UNSPEC;
 111                 hints.ai_socktype = SOCK_STREAM;
 112                 hints.ai_protocol = IPPROTO_TCP;
 113
 114                 snprintf(service, sizeof(service), "%d", port);
 115
 116                 ret = getaddrinfo(host, service, &hints, &resolver->ai);
 117                 if (ret != 0) {
 118                         free(resolver);
 119                         return NULL;
 120                 }
 121
 122                 resolver->next = resolver->ai;
 123                 resolver->type = TYPE_ANY;
 124 #else
 125                 const struct hostent *he;
 126
 127                 he = gethostbyname(host);
 128                 if (he == NULL) {
 129                         free(resolver);
 130                         return NULL;
 131                 }
 132
 133                 if (he->h_addrtype != AF_INET) {
 134                         free(resolver);
 135                         return NULL;
 136                 }
 137
 138
 139                 memset(&resolver->sin, 0, sizeof(resolver->sin));
 140                 resolver->sin.sin_family = AF_INET;
 141                 resolver->sin.sin_port = htons(port);
 142                 memcpy((char *)&resolver->sin.sin_addr.s_addr,
 143                        (char *)he->h_addr, he->h_length);
 144
 145                 resolver->current.family = PF_INET;
 146                 resolver->current.protocol = 0;
 147                 resolver->current.addrlen = sizeof(resolver->sin);
 148                 resolver->current.addr = (const struct sockaddr *)&resolver->sin;
 149
 150                 resolver->type = TYPE_ONE;
 151 #endif
 152 #ifndef WIN32
 153         }
 154 #endif
 155
 156         return resolver;
 157 }
 158
 159 void
 160 resolver_free(struct resolver *resolver)
 161 {
 162 #ifdef MPD_HAVE_GAI
 163         if (resolver->type == TYPE_ANY)
 164                 freeaddrinfo(resolver->ai);
 165 #endif
 166         free(resolver);
 167 }
 168
 169 const struct resolver_address *
 170 resolver_next(struct resolver *resolver)
 171 {
 172         if (resolver->type == TYPE_ZERO)
 173                 return NULL;
 174
 175         if (resolver->type == TYPE_ONE) {
 176                 resolver->type = TYPE_ZERO;
 177                 return &resolver->current;
 178         }
 179
 180 #ifdef MPD_HAVE_GAI
 181         if (resolver->next == NULL)
 182                 return NULL;
 183
 184         resolver->current.family = resolver->next->ai_family;
 185         resolver->current.protocol = resolver->next->ai_protocol;
 186         resolver->current.addrlen = resolver->next->ai_addrlen;
 187         resolver->current.addr = resolver->next->ai_addr;
 188
 189         resolver->next = resolver->next->ai_next;
 190
 191         return &resolver->current;
 192 #else
 193         return NULL;
 194 #endif
 195 }