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 #ifndef _GNU_SOURCE
  13 #define _GNU_SOURCE
  14 #endif
  15
  16 #include <stddef.h>
  17 #include <string.h>
  18 #include <errno.h>
  19
  20 #ifndef _WIN32
  21 #include <sys/ioctl.h>
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24 #include <net/if.h>
  25 #include <ifaddrs.h>
  26 #include <arpa/inet.h>
  27 #include <netinet/in.h>
  28 #endif
  29
  30 #include <lua.h>
  31 #include <lauxlib.h>
  32
  33 #if (LUA_VERSION_NUM == 501)
  34 #define luaL_setfuncs(L, R, N) luaL_register(L, NULL, R)
  35 #endif
  36
  37 /* Enumerate all locally configured IP addresses */
  38
  39 const char *const type_strings[] = {
  40         "both",
  41         "ipv4",
  42         "ipv6",
  43         NULL
  44 };
  45
  46 static int lc_local_addresses(lua_State *L) {
  47 #ifndef _WIN32
  48         /* Link-local IPv4 addresses; see RFC 3927 and RFC 5735 */
  49         const long ip4_linklocal = htonl(0xa9fe0000); /* 169.254.0.0 */
  50         const long ip4_mask      = htonl(0xffff0000);
  51         struct ifaddrs *addr = NULL, *a;
  52 #endif
  53         int n = 1;
  54         int type = luaL_checkoption(L, 1, "both", type_strings);
  55         const char link_local = lua_toboolean(L, 2); /* defaults to 0 (false) */
  56         const char ipv4 = (type == 0 || type == 1);
  57         const char ipv6 = (type == 0 || type == 2);
  58
  59 #ifndef _WIN32
  60
  61         if(getifaddrs(&addr) < 0) {
  62                 lua_pushnil(L);
  63                 lua_pushfstring(L, "getifaddrs failed (%d): %s", errno,
  64                                 strerror(errno));
  65                 return 2;
  66         }
  67
  68 #endif
  69         lua_newtable(L);
  70
  71 #ifndef _WIN32
  72
  73         for(a = addr; a; a = a->ifa_next) {
  74                 int family;
  75                 char ipaddr[INET6_ADDRSTRLEN];
  76                 const char *tmp = NULL;
  77
  78                 if(a->ifa_addr == NULL || a->ifa_flags & IFF_LOOPBACK) {
  79                         continue;
  80                 }
  81
  82                 family = a->ifa_addr->sa_family;
  83
  84                 if(ipv4 && family == AF_INET) {
  85                         struct sockaddr_in *sa = (struct sockaddr_in *)a->ifa_addr;
  86
  87                         if(!link_local && ((sa->sin_addr.s_addr & ip4_mask) == ip4_linklocal)) {
  88                                 continue;
  89                         }
  90
  91                         tmp = inet_ntop(family, &sa->sin_addr, ipaddr, sizeof(ipaddr));
  92                 } else if(ipv6 && family == AF_INET6) {
  93                         struct sockaddr_in6 *sa = (struct sockaddr_in6 *)a->ifa_addr;
  94
  95                         if(!link_local && IN6_IS_ADDR_LINKLOCAL(&sa->sin6_addr)) {
  96                                 continue;
  97                         }
  98
  99                         if(IN6_IS_ADDR_V4MAPPED(&sa->sin6_addr) || IN6_IS_ADDR_V4COMPAT(&sa->sin6_addr)) {
 100                                 continue;
 101                         }
 102
 103                         tmp = inet_ntop(family, &sa->sin6_addr, ipaddr, sizeof(ipaddr));
 104                 }
 105
 106                 if(tmp != NULL) {
 107                         lua_pushstring(L, tmp);
 108                         lua_rawseti(L, -2, n++);
 109                 }
 110
 111                 /* TODO: Error reporting? */
 112         }
 113
 114         freeifaddrs(addr);
 115 #else
 116
 117         if(ipv4) {
 118                 lua_pushstring(L, "0.0.0.0");
 119                 lua_rawseti(L, -2, n++);
 120         }
 121
 122         if(ipv6) {
 123                 lua_pushstring(L, "::");
 124                 lua_rawseti(L, -2, n++);
 125         }
 126
 127 #endif
 128         return 1;
 129 }
 130
 131 static int lc_pton(lua_State *L) {
 132         char buf[16];
 133         const char *ipaddr = luaL_checkstring(L, 1);
 134         int errno_ = 0;
 135         int family = strchr(ipaddr, ':') ? AF_INET6 : AF_INET;
 136
 137         switch(inet_pton(family, ipaddr, &buf)) {
 138                 case 1:
 139                         lua_pushlstring(L, buf, family == AF_INET6 ? 16 : 4);
 140                         return 1;
 141
 142                 case -1:
 143                         errno_ = errno;
 144                         lua_pushnil(L);
 145                         lua_pushstring(L, strerror(errno_));
 146                         lua_pushinteger(L, errno_);
 147                         return 3;
 148
 149                 default:
 150                 case 0:
 151                         lua_pushnil(L);
 152                         lua_pushstring(L, strerror(EINVAL));
 153                         lua_pushinteger(L, EINVAL);
 154                         return 3;
 155         }
 156
 157 }
 158
 159 static int lc_ntop(lua_State *L) {
 160         char buf[INET6_ADDRSTRLEN];
 161         int family;
 162         int errno_;
 163         size_t l;
 164         const char *ipaddr = luaL_checklstring(L, 1, &l);
 165
 166         if(l == 16) {
 167                 family = AF_INET6;
 168         }
 169         else if(l == 4) {
 170                 family = AF_INET;
 171         }
 172         else {
 173                 lua_pushnil(L);
 174                 lua_pushstring(L, strerror(EAFNOSUPPORT));
 175                 lua_pushinteger(L, EAFNOSUPPORT);
 176                 return 3;
 177         }
 178
 179         if(!inet_ntop(family, ipaddr, buf, INET6_ADDRSTRLEN))
 180         {
 181                 errno_ = errno;
 182                 lua_pushnil(L);
 183                 lua_pushstring(L, strerror(errno_));
 184                 lua_pushinteger(L, errno_);
 185                 return 3;
 186         }
 187
 188         lua_pushstring(L, (const char *)(&buf));
 189         return 1;
 190 }
 191
 192 int luaopen_util_net(lua_State *L) {
 193 #if (LUA_VERSION_NUM > 501)
 194         luaL_checkversion(L);
 195 #endif
 196         luaL_Reg exports[] = {
 197                 { "local_addresses", lc_local_addresses },
 198                 { "pton", lc_pton },
 199                 { "ntop", lc_ntop },
 200                 { NULL, NULL }
 201         };
 202
 203         lua_createtable(L, 0, 1);
 204         luaL_setfuncs(L, exports, 0);
 205         return 1;
 206 }