lib/socket/interfaces.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    return a list of network interfaces
   4    Copyright (C) Andrew Tridgell 1998
   5    Copyright (C) Jeremy Allison 2007
   6    Copyright (C) Jelmer Vernooij 2007
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22
  23 #include "includes.h"
  24 #include "system/network.h"
  25 #include "interfaces.h"
  26 #include "lib/util/tsort.h"
  27 #include "librpc/gen_ndr/ioctl.h"
  28
  29 /****************************************************************************
  30  Create a struct sockaddr_storage with the netmask bits set to 1.
  31 ****************************************************************************/
  32
  33 bool make_netmask(struct sockaddr_storage *pss_out,
  34                         const struct sockaddr_storage *pss_in,
  35                         unsigned long masklen)
  36 {
  37         *pss_out = *pss_in;
  38         /* Now apply masklen bits of mask. */
  39 #if defined(HAVE_IPV6)
  40         if (pss_in->ss_family == AF_INET6) {
  41                 char *p = (char *)&((struct sockaddr_in6 *)pss_out)->sin6_addr;
  42                 unsigned int i;
  43
  44                 if (masklen > 128) {
  45                         return false;
  46                 }
  47                 for (i = 0; masklen >= 8; masklen -= 8, i++) {
  48                         *p++ = 0xff;
  49                 }
  50                 /* Deal with the partial byte. */
  51                 *p++ &= (0xff & ~(0xff>>masklen));
  52                 i++;
  53                 for (;i < sizeof(struct in6_addr); i++) {
  54                         *p++ = '\0';
  55                 }
  56                 return true;
  57         }
  58 #endif
  59         if (pss_in->ss_family == AF_INET) {
  60                 if (masklen > 32) {
  61                         return false;
  62                 }
  63                 ((struct sockaddr_in *)pss_out)->sin_addr.s_addr =
  64                         htonl(((0xFFFFFFFFL >> masklen) ^ 0xFFFFFFFFL));
  65                 return true;
  66         }
  67         return false;
  68 }
  69
  70 /****************************************************************************
  71  Create a struct sockaddr_storage set to the broadcast or network adress from
  72  an incoming sockaddr_storage.
  73 ****************************************************************************/
  74
  75 static void make_bcast_or_net(struct sockaddr_storage *pss_out,
  76                         const struct sockaddr_storage *pss_in,
  77                         const struct sockaddr_storage *nmask,
  78                         bool make_bcast_p)
  79 {
  80         unsigned int i = 0, len = 0;
  81         const char *pmask = NULL;
  82         char *p = NULL;
  83         *pss_out = *pss_in;
  84
  85         /* Set all zero netmask bits to 1. */
  86 #if defined(HAVE_IPV6)
  87         if (pss_in->ss_family == AF_INET6) {
  88                 p = (char *)&((struct sockaddr_in6 *)pss_out)->sin6_addr;
  89                 pmask = (const char *)&((const struct sockaddr_in6 *)nmask)->sin6_addr;
  90                 len = 16;
  91         }
  92 #endif
  93         if (pss_in->ss_family == AF_INET) {
  94                 p = (char *)&((struct sockaddr_in *)pss_out)->sin_addr;
  95                 pmask = (const char *)&((const struct sockaddr_in *)nmask)->sin_addr;
  96                 len = 4;
  97         }
  98
  99         for (i = 0; i < len; i++, p++, pmask++) {
 100                 if (make_bcast_p) {
 101                         *p = (*p & *pmask) | (*pmask ^ 0xff);
 102                 } else {
 103                         /* make_net */
 104                         *p = (*p & *pmask);
 105                 }
 106         }
 107 }
 108
 109 void make_bcast(struct sockaddr_storage *pss_out,
 110                         const struct sockaddr_storage *pss_in,
 111                         const struct sockaddr_storage *nmask)
 112 {
 113         make_bcast_or_net(pss_out, pss_in, nmask, true);
 114 }
 115
 116 void make_net(struct sockaddr_storage *pss_out,
 117                         const struct sockaddr_storage *pss_in,
 118                         const struct sockaddr_storage *nmask)
 119 {
 120         make_bcast_or_net(pss_out, pss_in, nmask, false);
 121 }
 122
 123
 124 /****************************************************************************
 125  Try the "standard" getifaddrs/freeifaddrs interfaces.
 126  Also gets IPv6 interfaces.
 127 ****************************************************************************/
 128
 129 /****************************************************************************
 130  Get the netmask address for a local interface.
 131 ****************************************************************************/
 132
 133 static int _get_interfaces(TALLOC_CTX *mem_ctx, struct iface_struct **pifaces)
 134 {
 135         struct iface_struct *ifaces;
 136         struct ifaddrs *iflist = NULL;
 137         struct ifaddrs *ifptr = NULL;
 138         int count;
 139         int total = 0;
 140         size_t copy_size;
 141         uint64_t if_speed = 1000 * 1000 * 1000; /* 1GBit */
 142
 143         if (getifaddrs(&iflist) < 0) {
 144                 return -1;
 145         }
 146
 147         count = 0;
 148         for (ifptr = iflist; ifptr != NULL; ifptr = ifptr->ifa_next) {
 149                 if (!ifptr->ifa_addr || !ifptr->ifa_netmask) {
 150                         continue;
 151                 }
 152                 if (!(ifptr->ifa_flags & IFF_UP)) {
 153                         continue;
 154                 }
 155                 count += 1;
 156         }
 157
 158         ifaces = talloc_array(mem_ctx, struct iface_struct, count);
 159         if (ifaces == NULL) {
 160                 errno = ENOMEM;
 161                 return -1;
 162         }
 163
 164         /* Loop through interfaces, looking for given IP address */
 165         for (ifptr = iflist; ifptr != NULL; ifptr = ifptr->ifa_next) {
 166
 167                 if (!ifptr->ifa_addr || !ifptr->ifa_netmask) {
 168                         continue;
 169                 }
 170
 171                 /* Check the interface is up. */
 172                 if (!(ifptr->ifa_flags & IFF_UP)) {
 173                         continue;
 174                 }
 175
 176                 memset(&ifaces[total], '\0', sizeof(ifaces[total]));
 177
 178                 copy_size = sizeof(struct sockaddr_in);
 179
 180                 ifaces[total].flags = ifptr->ifa_flags;
 181
 182 #if defined(HAVE_IPV6)
 183                 if (ifptr->ifa_addr->sa_family == AF_INET6) {
 184                         copy_size = sizeof(struct sockaddr_in6);
 185                 }
 186 #endif
 187
 188                 memcpy(&ifaces[total].ip, ifptr->ifa_addr, copy_size);
 189                 memcpy(&ifaces[total].netmask, ifptr->ifa_netmask, copy_size);
 190
 191                 /* calculate broadcast address */
 192 #if defined(HAVE_IPV6)
 193                 if (ifptr->ifa_addr->sa_family == AF_INET6) {
 194                         struct sockaddr_in6 *sin6 =
 195                                 (struct sockaddr_in6 *)ifptr->ifa_addr;
 196                         struct in6_addr *in6 =
 197                                 (struct in6_addr *)&sin6->sin6_addr;
 198
 199                         if (IN6_IS_ADDR_LINKLOCAL(in6) || IN6_IS_ADDR_V4COMPAT(in6)) {
 200                                 continue;
 201                         }
 202                         /* IPv6 does not have broadcast it uses multicast. */
 203                         memset(&ifaces[total].bcast, '\0', copy_size);
 204                 } else
 205 #endif
 206                 if (ifaces[total].flags & (IFF_BROADCAST|IFF_LOOPBACK)) {
 207                         make_bcast(&ifaces[total].bcast,
 208                                 &ifaces[total].ip,
 209                                 &ifaces[total].netmask);
 210                 } else if ((ifaces[total].flags & IFF_POINTOPOINT) &&
 211                                ifptr->ifa_dstaddr ) {
 212                         memcpy(&ifaces[total].bcast,
 213                                 ifptr->ifa_dstaddr,
 214                                 copy_size);
 215                 } else {
 216                         continue;
 217                 }
 218
 219                 ifaces[total].if_index = if_nametoindex(ifptr->ifa_name);
 220                 if (ifaces[total].if_index == 0) {
 221                         DBG_ERR("Failed to retrieve interface index for '%s': "
 222                                 "%s\n", ifptr->ifa_name, strerror(errno));
 223                 }
 224
 225                 ifaces[total].linkspeed = if_speed;
 226                 ifaces[total].capability = FSCTL_NET_IFACE_NONE_CAPABLE;
 227
 228                 if (strlcpy(ifaces[total].name, ifptr->ifa_name,
 229                         sizeof(ifaces[total].name)) >=
 230                                 sizeof(ifaces[total].name)) {
 231                         /* Truncation ! Ignore. */
 232                         continue;
 233                 }
 234                 total++;
 235         }
 236
 237         freeifaddrs(iflist);
 238
 239         *pifaces = ifaces;
 240         return total;
 241 }
 242
 243 static int iface_comp(struct iface_struct *i1, struct iface_struct *i2)
 244 {
 245         int r;
 246
 247 #if defined(HAVE_IPV6)
 248         /*
 249          * If we have IPv6 - sort these interfaces lower
 250          * than any IPv4 ones.
 251          */
 252         if (i1->ip.ss_family == AF_INET6 &&
 253                         i2->ip.ss_family == AF_INET) {
 254                 return -1;
 255         } else if (i1->ip.ss_family == AF_INET &&
 256                         i2->ip.ss_family == AF_INET6) {
 257                 return 1;
 258         }
 259
 260         if (i1->ip.ss_family == AF_INET6) {
 261                 struct sockaddr_in6 *s1 = (struct sockaddr_in6 *)&i1->ip;
 262                 struct sockaddr_in6 *s2 = (struct sockaddr_in6 *)&i2->ip;
 263
 264                 r = memcmp(&s1->sin6_addr,
 265                                 &s2->sin6_addr,
 266                                 sizeof(struct in6_addr));
 267                 if (r) {
 268                         return r;
 269                 }
 270
 271                 s1 = (struct sockaddr_in6 *)&i1->netmask;
 272                 s2 = (struct sockaddr_in6 *)&i2->netmask;
 273
 274                 r = memcmp(&s1->sin6_addr,
 275                                 &s2->sin6_addr,
 276                                 sizeof(struct in6_addr));
 277                 if (r) {
 278                         return r;
 279                 }
 280         }
 281 #endif
 282
 283         /* AIX uses __ss_family instead of ss_family inside of
 284            sockaddr_storage. Instead of trying to figure out which field to
 285            use, we can just cast it to a sockaddr.
 286          */
 287
 288         if (((struct sockaddr *)&i1->ip)->sa_family == AF_INET) {
 289                 struct sockaddr_in *s1 = (struct sockaddr_in *)&i1->ip;
 290                 struct sockaddr_in *s2 = (struct sockaddr_in *)&i2->ip;
 291
 292                 r = ntohl(s1->sin_addr.s_addr) -
 293                         ntohl(s2->sin_addr.s_addr);
 294                 if (r) {
 295                         return r;
 296                 }
 297
 298                 s1 = (struct sockaddr_in *)&i1->netmask;
 299                 s2 = (struct sockaddr_in *)&i2->netmask;
 300
 301                 return ntohl(s1->sin_addr.s_addr) -
 302                         ntohl(s2->sin_addr.s_addr);
 303         }
 304         return 0;
 305 }
 306
 307 /* this wrapper is used to remove duplicates from the interface list generated
 308    above */
 309 int get_interfaces(TALLOC_CTX *mem_ctx, struct iface_struct **pifaces)
 310 {
 311         struct iface_struct *ifaces;
 312         int total, i, j;
 313
 314         total = _get_interfaces(mem_ctx, &ifaces);
 315         if (total <= 0) return total;
 316
 317         /* now we need to remove duplicates */
 318         TYPESAFE_QSORT(ifaces, total, iface_comp);
 319
 320         for (i=1;i<total;) {
 321                 if (iface_comp(&ifaces[i-1], &ifaces[i]) == 0) {
 322                         for (j=i-1;j<total-1;j++) {
 323                                 ifaces[j] = ifaces[j+1];
 324                         }
 325                         total--;
 326                 } else {
 327                         i++;
 328                 }
 329         }
 330
 331         *pifaces = ifaces;
 332         return total;
 333 }