external/bsd/ntp/dist/lib/isc/unix/ifiter_getifaddrs.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2004, 2005, 2007, 2008  Internet Systems Consortium, Inc. ("ISC")
   5  * Copyright (C) 2003  Internet Software Consortium.
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  12  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  13  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  14  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  15  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  16  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  17  * PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 /* Id: ifiter_getifaddrs.c,v 1.11 2008/03/20 23:47:00 tbox Exp */
  21
  22 /*! \file
  23  * \brief
  24  * Obtain the list of network interfaces using the getifaddrs(3) library.
  25  */
  26
  27 #include <ifaddrs.h>
  28
  29 /*% Iterator Magic */
  30 #define IFITER_MAGIC            ISC_MAGIC('I', 'F', 'I', 'G')
  31 /*% Valid Iterator */
  32 #define VALID_IFITER(t)         ISC_MAGIC_VALID(t, IFITER_MAGIC)
  33
  34 #ifdef __linux
  35 static isc_boolean_t seenv6 = ISC_FALSE;
  36 #endif
  37
  38 /*% Iterator structure */
  39 struct isc_interfaceiter {
  40         unsigned int            magic;          /*%< Magic number. */
  41         isc_mem_t               *mctx;
  42         void                    *buf;           /*%< (unused) */
  43         unsigned int            bufsize;        /*%< (always 0) */
  44         struct ifaddrs          *ifaddrs;       /*%< List of ifaddrs */
  45         struct ifaddrs          *pos;           /*%< Ptr to current ifaddr */
  46         isc_interface_t         current;        /*%< Current interface data. */
  47         isc_result_t            result;         /*%< Last result code. */
  48 #ifdef  __linux
  49         FILE *                  proc;
  50         char                    entry[ISC_IF_INET6_SZ];
  51         isc_result_t            valid;
  52 #endif
  53 };
  54
  55 isc_result_t
  56 isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
  57         isc_interfaceiter_t *iter;
  58         isc_result_t result;
  59         char strbuf[ISC_STRERRORSIZE];
  60
  61         REQUIRE(mctx != NULL);
  62         REQUIRE(iterp != NULL);
  63         REQUIRE(*iterp == NULL);
  64
  65         iter = isc_mem_get(mctx, sizeof(*iter));
  66         if (iter == NULL)
  67                 return (ISC_R_NOMEMORY);
  68
  69         iter->mctx = mctx;
  70         iter->buf = NULL;
  71         iter->bufsize = 0;
  72         iter->ifaddrs = NULL;
  73 #ifdef __linux
  74         /*
  75          * Only open "/proc/net/if_inet6" if we have never seen a IPv6
  76          * address returned by getifaddrs().
  77          */
  78         if (!seenv6)
  79                 iter->proc = fopen("/proc/net/if_inet6", "r");
  80         else
  81                 iter->proc = NULL;
  82         iter->valid = ISC_R_FAILURE;
  83 #endif
  84
  85         if (getifaddrs(&iter->ifaddrs) < 0) {
  86                 isc__strerror(errno, strbuf, sizeof(strbuf));
  87                 UNEXPECTED_ERROR(__FILE__, __LINE__,
  88                                  isc_msgcat_get(isc_msgcat,
  89                                                 ISC_MSGSET_IFITERGETIFADDRS,
  90                                                 ISC_MSG_GETIFADDRS,
  91                                                 "getting interface "
  92                                                 "addresses: getifaddrs: %s"),
  93                                  strbuf);
  94                 result = ISC_R_UNEXPECTED;
  95                 goto failure;
  96         }
  97
  98         /*
  99          * A newly created iterator has an undefined position
 100          * until isc_interfaceiter_first() is called.
 101          */
 102         iter->pos = NULL;
 103         iter->result = ISC_R_FAILURE;
 104
 105         iter->magic = IFITER_MAGIC;
 106         *iterp = iter;
 107         return (ISC_R_SUCCESS);
 108
 109  failure:
 110 #ifdef __linux
 111         if (iter->proc != NULL)
 112                 fclose(iter->proc);
 113 #endif
 114         if (iter->ifaddrs != NULL) /* just in case */
 115                 freeifaddrs(iter->ifaddrs);
 116         isc_mem_put(mctx, iter, sizeof(*iter));
 117         return (result);
 118 }
 119
 120 /*
 121  * Get information about the current interface to iter->current.
 122  * If successful, return ISC_R_SUCCESS.
 123  * If the interface has an unsupported address family,
 124  * return ISC_R_IGNORE.
 125  */
 126
 127 static isc_result_t
 128 internal_current(isc_interfaceiter_t *iter) {
 129         struct ifaddrs *ifa;
 130         int family;
 131         unsigned int namelen;
 132
 133         REQUIRE(VALID_IFITER(iter));
 134
 135         ifa = iter->pos;
 136
 137 #ifdef __linux
 138         if (iter->pos == NULL)
 139                 return (linux_if_inet6_current(iter));
 140 #endif
 141
 142         INSIST(ifa != NULL);
 143         INSIST(ifa->ifa_name != NULL);
 144
 145         if (ifa->ifa_addr == NULL)
 146                 return (ISC_R_IGNORE);
 147
 148         family = ifa->ifa_addr->sa_family;
 149         if (family != AF_INET && family != AF_INET6)
 150                 return (ISC_R_IGNORE);
 151
 152 #ifdef __linux
 153         if (family == AF_INET6)
 154                 seenv6 = ISC_TRUE;
 155 #endif
 156
 157         memset(&iter->current, 0, sizeof(iter->current));
 158
 159         namelen = strlen(ifa->ifa_name);
 160         if (namelen > sizeof(iter->current.name) - 1)
 161                 namelen = sizeof(iter->current.name) - 1;
 162
 163         memset(iter->current.name, 0, sizeof(iter->current.name));
 164         memcpy(iter->current.name, ifa->ifa_name, namelen);
 165
 166         iter->current.flags = 0;
 167
 168         if ((ifa->ifa_flags & IFF_UP) != 0)
 169                 iter->current.flags |= INTERFACE_F_UP;
 170
 171         if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0)
 172                 iter->current.flags |= INTERFACE_F_POINTTOPOINT;
 173
 174         if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
 175                 iter->current.flags |= INTERFACE_F_LOOPBACK;
 176
 177         if ((ifa->ifa_flags & IFF_BROADCAST) != 0)
 178                 iter->current.flags |= INTERFACE_F_BROADCAST;
 179
 180 #ifdef IFF_MULTICAST
 181         if ((ifa->ifa_flags & IFF_MULTICAST) != 0)
 182                 iter->current.flags |= INTERFACE_F_MULTICAST;
 183 #endif
 184
 185         iter->current.af = family;
 186
 187         get_addr(family, &iter->current.address, ifa->ifa_addr, ifa->ifa_name);
 188
 189         if (ifa->ifa_netmask != NULL)
 190                 get_addr(family, &iter->current.netmask, ifa->ifa_netmask,
 191                          ifa->ifa_name);
 192
 193         if (ifa->ifa_dstaddr != NULL &&
 194             (iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0)
 195                 get_addr(family, &iter->current.dstaddress, ifa->ifa_dstaddr,
 196                          ifa->ifa_name);
 197
 198         if (ifa->ifa_broadaddr != NULL &&
 199             (iter->current.flags & INTERFACE_F_BROADCAST) != 0)
 200                 get_addr(family, &iter->current.broadcast, ifa->ifa_broadaddr,
 201                          ifa->ifa_name);
 202
 203         return (ISC_R_SUCCESS);
 204 }
 205
 206 /*
 207  * Step the iterator to the next interface.  Unlike
 208  * isc_interfaceiter_next(), this may leave the iterator
 209  * positioned on an interface that will ultimately
 210  * be ignored.  Return ISC_R_NOMORE if there are no more
 211  * interfaces, otherwise ISC_R_SUCCESS.
 212  */
 213 static isc_result_t
 214 internal_next(isc_interfaceiter_t *iter) {
 215
 216         if (iter->pos != NULL)
 217                 iter->pos = iter->pos->ifa_next;
 218         if (iter->pos == NULL) {
 219 #ifdef __linux
 220                 if (!seenv6)
 221                         return (linux_if_inet6_next(iter));
 222 #endif
 223                 return (ISC_R_NOMORE);
 224         }
 225
 226         return (ISC_R_SUCCESS);
 227 }
 228
 229 static void
 230 internal_destroy(isc_interfaceiter_t *iter) {
 231
 232 #ifdef __linux
 233         if (iter->proc != NULL)
 234                 fclose(iter->proc);
 235         iter->proc = NULL;
 236 #endif
 237         if (iter->ifaddrs)
 238                 freeifaddrs(iter->ifaddrs);
 239         iter->ifaddrs = NULL;
 240 }
 241
 242 static
 243 void internal_first(isc_interfaceiter_t *iter) {
 244
 245 #ifdef __linux
 246         linux_if_inet6_first(iter);
 247 #endif
 248         iter->pos = iter->ifaddrs;
 249 }