util-src/net.c

   1 /* Prosody IM
   2 --
   3 -- This project is MIT/X11 licensed. Please see the
   4 -- COPYING file in the source package for more information.
   5 --
   6 -- Copyright (C) 2012 Paul Aurich
   7 -- Copyright (C) 2013 Matthew Wild
   8 -- Copyright (C) 2013 Florian Zeitz
   9 --
  10 */
  11
  12 #define _GNU_SOURCE
  13 #include <stddef.h>
  14 #include <string.h>
  15 #include <errno.h>
  16
  17 #ifndef _WIN32
  18 #include <sys/ioctl.h>
  19 #include <sys/types.h>
  20 #include <sys/socket.h>
  21 #include <net/if.h>
  22 #include <ifaddrs.h>
  23 #include <arpa/inet.h>
  24 #include <netinet/in.h>
  25 #endif
  26
  27 #include <lua.h>
  28 #include <lauxlib.h>
  29
  30 #if (LUA_VERSION_NUM == 501)
  31 #define luaL_setfuncs(L, R, N) luaL_register(L, NULL, R)
  32 #endif
  33
  34 /* Enumerate all locally configured IP addresses */
  35
  36 const char *const type_strings[] = {
  37         "both",
  38         "ipv4",
  39         "ipv6",
  40         NULL
  41 };
  42
  43 static int lc_local_addresses(lua_State *L) {
  44 #ifndef _WIN32
  45         /* Link-local IPv4 addresses; see RFC 3927 and RFC 5735 */
  46         const long ip4_linklocal = htonl(0xa9fe0000); /* 169.254.0.0 */
  47         const long ip4_mask      = htonl(0xffff0000);
  48         struct ifaddrs *addr = NULL, *a;
  49 #endif
  50         int n = 1;
  51         int type = luaL_checkoption(L, 1, "both", type_strings);
  52         const char link_local = lua_toboolean(L, 2); /* defaults to 0 (false) */
  53         const char ipv4 = (type == 0 || type == 1);
  54         const char ipv6 = (type == 0 || type == 2);
  55
  56 #ifndef _WIN32
  57
  58         if(getifaddrs(&addr) < 0) {
  59                 lua_pushnil(L);
  60                 lua_pushfstring(L, "getifaddrs failed (%d): %s", errno,
  61                                 strerror(errno));
  62                 return 2;
  63         }
  64
  65 #endif
  66         lua_newtable(L);
  67
  68 #ifndef _WIN32
  69
  70         for(a = addr; a; a = a->ifa_next) {
  71                 int family;
  72                 char ipaddr[INET6_ADDRSTRLEN];
  73                 const char *tmp = NULL;
  74
  75                 if(a->ifa_addr == NULL || a->ifa_flags & IFF_LOOPBACK) {
  76                         continue;
  77                 }
  78
  79                 family = a->ifa_addr->sa_family;
  80
  81                 if(ipv4 && family == AF_INET) {
  82                         struct sockaddr_in *sa = (struct sockaddr_in *)a->ifa_addr;
  83
  84                         if(!link_local && ((sa->sin_addr.s_addr & ip4_mask) == ip4_linklocal)) {
  85                                 continue;
  86                         }
  87
  88                         tmp = inet_ntop(family, &sa->sin_addr, ipaddr, sizeof(ipaddr));
  89                 } else if(ipv6 && family == AF_INET6) {
  90                         struct sockaddr_in6 *sa = (struct sockaddr_in6 *)a->ifa_addr;
  91
  92                         if(!link_local && IN6_IS_ADDR_LINKLOCAL(&sa->sin6_addr)) {
  93                                 continue;
  94                         }
  95
  96                         if(IN6_IS_ADDR_V4MAPPED(&sa->sin6_addr) || IN6_IS_ADDR_V4COMPAT(&sa->sin6_addr)) {
  97                                 continue;
  98                         }
  99
 100                         tmp = inet_ntop(family, &sa->sin6_addr, ipaddr, sizeof(ipaddr));
 101                 }
 102
 103                 if(tmp != NULL) {
 104                         lua_pushstring(L, tmp);
 105                         lua_rawseti(L, -2, n++);
 106                 }
 107
 108                 /* TODO: Error reporting? */
 109         }
 110
 111         freeifaddrs(addr);
 112 #else
 113
 114         if(ipv4) {
 115                 lua_pushstring(L, "0.0.0.0");
 116                 lua_rawseti(L, -2, n++);
 117         }
 118
 119         if(ipv6) {
 120                 lua_pushstring(L, "::");
 121                 lua_rawseti(L, -2, n++);
 122         }
 123
 124 #endif
 125         return 1;
 126 }
 127
 128 int luaopen_util_net(lua_State *L) {
 129 #if (LUA_VERSION_NUM > 501)
 130         luaL_checkversion(L);
 131 #endif
 132         luaL_Reg exports[] = {
 133                 { "local_addresses", lc_local_addresses },
 134                 { NULL, NULL }
 135         };
 136
 137         lua_createtable(L, 0, 1);
 138         luaL_setfuncs(L, exports, 0);
 139         return 1;
 140 }