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 "config.h"
  34 #include "resolver.h"
  35
  36 #include <netdb.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40
  41 #ifdef WIN32
  42 #  include <ws2tcpip.h>
  43 #  include <winsock.h>
  44 #else
  45 #  include <netinet/in.h>
  46 #  include <arpa/inet.h>
  47 #  include <sys/socket.h>
  48 #  include <sys/un.h>
  49 #  include <netdb.h>
  50 #endif
  51
  52 #ifndef MPD_NO_GAI
  53 #  ifdef AI_ADDRCONFIG
  54 #    define MPD_HAVE_GAI
  55 #  endif
  56 #endif
  57
  58 struct resolver {
  59         enum {
  60                 TYPE_ZERO, TYPE_ONE, TYPE_ANY
  61         } type;
  62
  63 #ifdef MPD_HAVE_GAI
  64         struct addrinfo *ai;
  65         const struct addrinfo *next;
  66 #else
  67         struct sockaddr_in sin;
  68 #endif
  69
  70         struct resolver_address current;
  71
  72 #ifndef WIN32
  73         struct sockaddr_un saun;
  74 #endif
  75 };
  76
  77 struct resolver *
  78 resolver_new(const char *host, int port)
  79 {
  80         struct resolver *resolver;
  81
  82         resolver = malloc(sizeof(*resolver));
  83         if (resolver == NULL)
  84                 return NULL;
  85
  86 #ifndef WIN32
  87         if (host[0] == '/') {
  88                 size_t path_length = strlen(host);
  89                 if (path_length >= sizeof(resolver->saun.sun_path)) {
  90                         free(resolver);
  91                         return NULL;
  92                 }
  93
  94                 resolver->saun.sun_family = AF_UNIX;
  95                 memcpy(resolver->saun.sun_path, host, path_length + 1);
  96
  97                 resolver->current.family = PF_UNIX;
  98                 resolver->current.protocol = 0;
  99                 resolver->current.addrlen = sizeof(resolver->saun);
 100                 resolver->current.addr = (const struct sockaddr *)&resolver->saun;
 101                 resolver->type = TYPE_ONE;
 102         } else {
 103 #endif
 104 #ifdef MPD_HAVE_GAI
 105                 struct addrinfo hints;
 106                 char service[20];
 107                 int ret;
 108
 109                 memset(&hints, 0, sizeof(hints));
 110                 hints.ai_flags = AI_ADDRCONFIG;
 111                 hints.ai_family = PF_UNSPEC;
 112                 hints.ai_socktype = SOCK_STREAM;
 113                 hints.ai_protocol = IPPROTO_TCP;
 114
 115                 snprintf(service, sizeof(service), "%d", port);
 116
 117                 ret = getaddrinfo(host, service, &hints, &resolver->ai);
 118                 if (ret != 0) {
 119                         free(resolver);
 120                         return NULL;
 121                 }
 122
 123                 resolver->next = resolver->ai;
 124                 resolver->type = TYPE_ANY;
 125 #else
 126                 const struct hostent *he;
 127
 128                 he = gethostbyname(host);
 129                 if (he == NULL) {
 130                         free(resolver);
 131                         return NULL;
 132                 }
 133
 134                 if (he->h_addrtype != AF_INET) {
 135                         free(resolver);
 136                         return NULL;
 137                 }
 138
 139
 140                 memset(&resolver->sin, 0, sizeof(resolver->sin));
 141                 resolver->sin.sin_family = AF_INET;
 142                 resolver->sin.sin_port = htons(port);
 143                 memcpy((char *)&resolver->sin.sin_addr.s_addr,
 144                        (char *)he->h_addr, he->h_length);
 145
 146                 resolver->current.family = PF_INET;
 147                 resolver->current.protocol = 0;
 148                 resolver->current.addrlen = sizeof(resolver->sin);
 149                 resolver->current.addr = (const struct sockaddr *)&resolver->sin;
 150
 151                 resolver->type = TYPE_ONE;
 152 #endif
 153 #ifndef WIN32
 154         }
 155 #endif
 156
 157         return resolver;
 158 }
 159
 160 void
 161 resolver_free(struct resolver *resolver)
 162 {
 163 #ifdef MPD_HAVE_GAI
 164         if (resolver->type == TYPE_ANY)
 165                 freeaddrinfo(resolver->ai);
 166 #endif
 167         free(resolver);
 168 }
 169
 170 const struct resolver_address *
 171 resolver_next(struct resolver *resolver)
 172 {
 173         if (resolver->type == TYPE_ZERO)
 174                 return NULL;
 175
 176         if (resolver->type == TYPE_ONE) {
 177                 resolver->type = TYPE_ZERO;
 178                 return &resolver->current;
 179         }
 180
 181 #ifdef MPD_HAVE_GAI
 182         if (resolver->next == NULL)
 183                 return NULL;
 184
 185         resolver->current.family = resolver->next->ai_family;
 186         resolver->current.protocol = resolver->next->ai_protocol;
 187         resolver->current.addrlen = resolver->next->ai_addrlen;
 188         resolver->current.addr = resolver->next->ai_addr;
 189
 190         resolver->next = resolver->next->ai_next;
 191
 192         return &resolver->current;
 193 #else
 194         return NULL;
 195 #endif
 196 }