src/net/resolver.c

   1 /* libmpdclient
   2    (c) 2003-2017 The Music Player Daemon Project
   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    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
  20    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  21    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  22    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  23    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  24    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  25    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  26    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27 */
  28
  29 #include "resolver.h"
  30 #include "config.h"
  31
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35
  36 #ifdef WIN32
  37 #  include <winsock2.h>
  38 #  include <ws2tcpip.h>
  39 #else
  40 #  include <sys/socket.h>
  41 #  include <sys/un.h>
  42 #ifdef ENABLE_TCP
  43 #  include <netinet/in.h>
  44 #  include <arpa/inet.h>
  45 #  include <netdb.h>
  46 #endif
  47 #endif
  48
  49 struct resolver {
  50         enum {
  51                 TYPE_ZERO, TYPE_ONE, TYPE_ANY
  52         } type;
  53
  54 #ifdef ENABLE_TCP
  55 #ifdef HAVE_GETADDRINFO
  56         struct addrinfo *ai;
  57         const struct addrinfo *next;
  58 #else
  59         struct sockaddr_in sin;
  60 #endif
  61 #endif
  62
  63         struct resolver_address current;
  64
  65 #ifndef WIN32
  66         struct sockaddr_un saun;
  67 #endif
  68 };
  69
  70 struct resolver *
  71 resolver_new(const char *host, unsigned port)
  72 {
  73         struct resolver *resolver;
  74
  75         resolver = malloc(sizeof(*resolver));
  76         if (resolver == NULL)
  77                 return NULL;
  78
  79         if (host[0] == '/' || host[0] == '@') {
  80 #ifndef WIN32
  81                 size_t path_length = strlen(host);
  82                 if (path_length >= sizeof(resolver->saun.sun_path)) {
  83                         free(resolver);
  84                         return NULL;
  85                 }
  86
  87                 resolver->saun.sun_family = AF_UNIX;
  88                 memcpy(resolver->saun.sun_path, host, path_length + 1);
  89
  90                 if (host[0] == '@')
  91                         /* abstract socket */
  92                         resolver->saun.sun_path[0] = 0;
  93
  94                 resolver->current.family = PF_UNIX;
  95                 resolver->current.protocol = 0;
  96                 resolver->current.addrlen = sizeof(resolver->saun);
  97                 resolver->current.addr = (const struct sockaddr *)&resolver->saun;
  98                 resolver->type = TYPE_ONE;
  99 #else /* WIN32 */
 100                 /* there are no UNIX domain sockets on Windows */
 101                 free(resolver);
 102                 return NULL;
 103 #endif /* WIN32 */
 104         } else {
 105 #ifdef ENABLE_TCP
 106 #ifdef HAVE_GETADDRINFO
 107                 struct addrinfo hints;
 108                 char service[20];
 109                 int ret;
 110
 111                 memset(&hints, 0, sizeof(hints));
 112                 hints.ai_family = PF_UNSPEC;
 113                 hints.ai_socktype = SOCK_STREAM;
 114                 hints.ai_protocol = IPPROTO_TCP;
 115
 116                 snprintf(service, sizeof(service), "%d", port);
 117
 118                 ret = getaddrinfo(host, service, &hints, &resolver->ai);
 119                 if (ret != 0) {
 120                         free(resolver);
 121                         return NULL;
 122                 }
 123
 124                 resolver->next = resolver->ai;
 125                 resolver->type = TYPE_ANY;
 126 #else
 127                 const struct hostent *he;
 128
 129                 he = gethostbyname(host);
 130                 if (he == NULL) {
 131                         free(resolver);
 132                         return NULL;
 133                 }
 134
 135                 if (he->h_addrtype != AF_INET) {
 136                         free(resolver);
 137                         return NULL;
 138                 }
 139
 140
 141                 memset(&resolver->sin, 0, sizeof(resolver->sin));
 142                 resolver->sin.sin_family = AF_INET;
 143                 resolver->sin.sin_port = htons(port);
 144                 memcpy((char *)&resolver->sin.sin_addr.s_addr,
 145                        (char *)he->h_addr, he->h_length);
 146
 147                 resolver->current.family = PF_INET;
 148                 resolver->current.protocol = 0;
 149                 resolver->current.addrlen = sizeof(resolver->sin);
 150                 resolver->current.addr = (const struct sockaddr *)&resolver->sin;
 151
 152                 resolver->type = TYPE_ONE;
 153 #endif
 154 #else /* !ENABLE_TCP */
 155                 (void)port;
 156                 free(resolver);
 157                 return NULL;
 158 #endif
 159         }
 160
 161         return resolver;
 162 }
 163
 164 void
 165 resolver_free(struct resolver *resolver)
 166 {
 167 #if defined(ENABLE_TCP) && defined(HAVE_GETADDRINFO)
 168         if (resolver->type == TYPE_ANY)
 169                 freeaddrinfo(resolver->ai);
 170 #endif
 171         free(resolver);
 172 }
 173
 174 const struct resolver_address *
 175 resolver_next(struct resolver *resolver)
 176 {
 177         if (resolver->type == TYPE_ZERO)
 178                 return NULL;
 179
 180         if (resolver->type == TYPE_ONE) {
 181                 resolver->type = TYPE_ZERO;
 182                 return &resolver->current;
 183         }
 184
 185 #if defined(ENABLE_TCP) && defined(HAVE_GETADDRINFO)
 186         if (resolver->next == NULL)
 187                 return NULL;
 188
 189         resolver->current.family = resolver->next->ai_family;
 190         resolver->current.protocol = resolver->next->ai_protocol;
 191         resolver->current.addrlen = resolver->next->ai_addrlen;
 192         resolver->current.addr = resolver->next->ai_addr;
 193
 194         resolver->next = resolver->next->ai_next;
 195
 196         return &resolver->current;
 197 #else
 198         return NULL;
 199 #endif
 200 }