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
  75                 /* Initialize sockaddr for bind */
  76                 sin6ptr->sin6_family = family;
  77                 sin6ptr->sin6_addr = in6addr_any;
  78                 sin6ptr->sin6_port = htons(*port);
  79
  80                 socklen = sizeof(*sin6ptr);
  81                 ret = bind(server_fd, (struct sockaddr *)sin6ptr, socklen);
  82                 if (ret == -1) {
  83                         goto cleanup;
  84                 }
  85
  86                 ret = getsockname(server_fd, (struct sockaddr *)sin6ptr, &socklen);
  87                 if (ret == -1) {
  88                         goto cleanup;
  89                 }
  90                 *port = ntohs(sin6ptr->sin6_port);
  91         } else {
  92                 struct sockaddr_in *sinptr = (struct sockaddr_in *)&saddr;
  93
  94                 /* Initialize sockaddr for bind */
  95                 sinptr->sin_family = family;
  96                 sinptr->sin_addr.s_addr = INADDR_ANY;
  97                 sinptr->sin_port = htons(*port);
  98
  99                 socklen = sizeof(*sinptr);
 100                 ret = bind(server_fd, (struct sockaddr *)sinptr, socklen);
 101                 if (ret == -1) {
 102                         goto cleanup;
 103                 }
 104
 105                 ret = getsockname(server_fd, (struct sockaddr *)sinptr, &socklen);
 106                 if (ret == -1) {
 107                         goto cleanup;
 108                 }
 109                 *port = ntohs(sinptr->sin_port);
 110         }
 111         return server_fd;
 112
 113 cleanup:
 114         ret = SOCKET_GET_ERROR();
 115         if (server_fd != -1) {
 116                 closesocket(server_fd);
 117         }
 118         SOCKET_SET_ERROR(ret);
 119         return -1;
 120 }
 121
 122 unsigned char *
 123 netutils_get_address(void *sockaddr, int *length)
 124 {
 125         unsigned char ipv4_prefix[] = { 0,0,0,0,0,0,0,0,0,0,255,255 };
 126         struct sockaddr *address = sockaddr;
 127
 128         assert(address);
 129         assert(length);
 130
 131         if (address->sa_family == AF_INET) {
 132                 struct sockaddr_in *sin;
 133
 134                 sin = (struct sockaddr_in *)address;
 135                 *length = sizeof(sin->sin_addr.s_addr);
 136                 return (unsigned char *)&sin->sin_addr.s_addr;
 137         } else if (address->sa_family == AF_INET6) {
 138                 struct sockaddr_in6 *sin6;
 139
 140                 sin6 = (struct sockaddr_in6 *)address;
 141                 if (!memcmp(sin6->sin6_addr.s6_addr, ipv4_prefix, 12)) {
 142                         /* Actually an embedded IPv4 address */
 143                         *length = sizeof(sin6->sin6_addr.s6_addr)-12;
 144                         return (sin6->sin6_addr.s6_addr+12);
 145                 }
 146                 *length = sizeof(sin6->sin6_addr.s6_addr);
 147                 return sin6->sin6_addr.s6_addr;
 148         }
 149
 150         *length = 0;
 151         return NULL;
 152 }
 153