src/lib/netutils.c

   1 /**
   2  *  Copyright (C) 2011-2012  Juho Vähä-Herttua
   3  *
   4  *  This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Lesser General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2.1 of the License, or (at your option) any later version.
   8  *
   9  *  This library 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 GNU
  12  *  Lesser General Public License for more details.
  13  */
  14
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <assert.h>
  18
  19 #include "compat.h"
  20
  21 int
  22 netutils_init()
  23 {
  24 #ifdef WIN32
  25         WORD wVersionRequested;
  26         WSADATA wsaData;
  27         int ret;
  28
  29         wVersionRequested = MAKEWORD(2, 2);
  30         ret = WSAStartup(wVersionRequested, &wsaData);
  31         if (ret) {
  32                 return -1;
  33         }
  34
  35         if (LOBYTE(wsaData.wVersion) != 2 ||
  36             HIBYTE(wsaData.wVersion) != 2) {
  37                 /* Version mismatch, requested version not found */
  38                 return -1;
  39         }
  40 #endif
  41         return 0;
  42 }
  43
  44 void
  45 netutils_cleanup()
  46 {
  47 #ifdef WIN32
  48         WSACleanup();
  49 #endif
  50 }
  51
  52 int
  53 netutils_init_socket(unsigned short *port, int use_ipv6, int use_udp)
  54 {
  55         int family = use_ipv6 ? AF_INET6 : AF_INET;
  56         int type = use_udp ? SOCK_DGRAM : SOCK_STREAM;
  57         int proto = use_udp ? IPPROTO_UDP : IPPROTO_TCP;
  58
  59         struct sockaddr_storage saddr;
  60         socklen_t socklen;
  61         int server_fd;
  62         int ret;
  63
  64         assert(port);
  65
  66         server_fd = socket(family, type, proto);
  67         if (server_fd == -1) {
  68                 goto cleanup;
  69         }
  70
  71         memset(&saddr, 0, sizeof(saddr));
  72         if (use_ipv6) {
  73                 struct sockaddr_in6 *sin6ptr = (struct sockaddr_in6 *)&saddr;
  74                 int v6only = 1;
  75
  76                 /* Initialize sockaddr for bind */
  77                 sin6ptr->sin6_family = family;
  78                 sin6ptr->sin6_addr = in6addr_any;
  79                 sin6ptr->sin6_port = htons(*port);
  80
  81                 /* Make sure we only listen to IPv6 addresses */
  82                 setsockopt(server_fd, IPPROTO_IPV6, IPV6_V6ONLY,
  83                            (char *) &v6only, sizeof(v6only));
  84
  85                 socklen = sizeof(*sin6ptr);
  86                 ret = bind(server_fd, (struct sockaddr *)sin6ptr, socklen);
  87                 if (ret == -1) {
  88                         goto cleanup;
  89                 }
  90
  91                 ret = getsockname(server_fd, (struct sockaddr *)sin6ptr, &socklen);
  92                 if (ret == -1) {
  93                         goto cleanup;
  94                 }
  95                 *port = ntohs(sin6ptr->sin6_port);
  96         } else {
  97                 struct sockaddr_in *sinptr = (struct sockaddr_in *)&saddr;
  98
  99                 /* Initialize sockaddr for bind */
 100                 sinptr->sin_family = family;
 101                 sinptr->sin_addr.s_addr = INADDR_ANY;
 102                 sinptr->sin_port = htons(*port);
 103
 104                 socklen = sizeof(*sinptr);
 105                 ret = bind(server_fd, (struct sockaddr *)sinptr, socklen);
 106                 if (ret == -1) {
 107                         goto cleanup;
 108                 }
 109
 110                 ret = getsockname(server_fd, (struct sockaddr *)sinptr, &socklen);
 111                 if (ret == -1) {
 112                         goto cleanup;
 113                 }
 114                 *port = ntohs(sinptr->sin_port);
 115         }
 116         return server_fd;
 117
 118 cleanup:
 119         ret = SOCKET_GET_ERROR();
 120         if (server_fd != -1) {
 121                 closesocket(server_fd);
 122         }
 123         SOCKET_SET_ERROR(ret);
 124         return -1;
 125 }
 126
 127 unsigned char *
 128 netutils_get_address(void *sockaddr, int *length)
 129 {
 130         unsigned char ipv4_prefix[] = { 0,0,0,0,0,0,0,0,0,0,255,255 };
 131         struct sockaddr *address = sockaddr;
 132
 133         assert(address);
 134         assert(length);
 135
 136         if (address->sa_family == AF_INET) {
 137                 struct sockaddr_in *sin;
 138
 139                 sin = (struct sockaddr_in *)address;
 140                 *length = sizeof(sin->sin_addr.s_addr);
 141                 return (unsigned char *)&sin->sin_addr.s_addr;
 142         } else if (address->sa_family == AF_INET6) {
 143                 struct sockaddr_in6 *sin6;
 144
 145                 sin6 = (struct sockaddr_in6 *)address;
 146                 if (!memcmp(sin6->sin6_addr.s6_addr, ipv4_prefix, 12)) {
 147                         /* Actually an embedded IPv4 address */
 148                         *length = sizeof(sin6->sin6_addr.s6_addr)-12;
 149                         return (sin6->sin6_addr.s6_addr+12);
 150                 }
 151                 *length = sizeof(sin6->sin6_addr.s6_addr);
 152                 return sin6->sin6_addr.s6_addr;
 153         }
 154
 155         *length = 0;
 156         return NULL;
 157 }
 158
 159 int
 160 netutils_parse_address(int family, const char *src, void *dst, int dstlen)
 161 {
 162         struct addrinfo *result;
 163         struct addrinfo *ptr;
 164         struct addrinfo hints;
 165         int length;
 166         int ret;
 167
 168         if (family != AF_INET && family != AF_INET6) {
 169                 return -1;
 170         }
 171         if (!src || !dst) {
 172                 return -1;
 173         }
 174
 175         memset(&hints, 0, sizeof(hints));
 176         hints.ai_family = family;
 177         hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
 178
 179         ret = getaddrinfo(src, NULL, &hints, &result);
 180         if (ret != 0) {
 181                 return -1;
 182         }
 183
 184         length = -1;
 185         for (ptr=result; ptr!=NULL; ptr=ptr->ai_next) {
 186                 if (family == ptr->ai_family && (unsigned int)dstlen >= ptr->ai_addrlen) {
 187                         memcpy(dst, ptr->ai_addr, ptr->ai_addrlen);
 188                         length = ptr->ai_addrlen;
 189                         break;
 190                 }
 191         }
 192         freeaddrinfo(result);
 193         return length;
 194 }