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 #ifdef HAVE_ETHTOOL
  30 #include "linux/sockios.h"
  31 #include "linux/ethtool.h"
  32 #endif
  33
  34 /****************************************************************************
  35  Create a struct sockaddr_storage with the netmask bits set to 1.
  36 ****************************************************************************/
  37
  38 bool make_netmask(struct sockaddr_storage *pss_out,
  39                         const struct sockaddr_storage *pss_in,
  40                         unsigned long masklen)
  41 {
  42         *pss_out = *pss_in;
  43         /* Now apply masklen bits of mask. */
  44 #if defined(HAVE_IPV6)
  45         if (pss_in->ss_family == AF_INET6) {
  46                 char *p = (char *)&((struct sockaddr_in6 *)pss_out)->sin6_addr;
  47                 unsigned int i;
  48
  49                 if (masklen > 128) {
  50                         return false;
  51                 }
  52                 for (i = 0; masklen >= 8; masklen -= 8, i++) {
  53                         *p++ = 0xff;
  54                 }
  55                 /* Deal with the partial byte. */
  56                 *p++ &= (0xff & ~(0xff>>masklen));
  57                 i++;
  58                 for (;i < sizeof(struct in6_addr); i++) {
  59                         *p++ = '\0';
  60                 }
  61                 return true;
  62         }
  63 #endif
  64         if (pss_in->ss_family == AF_INET) {
  65                 if (masklen > 32) {
  66                         return false;
  67                 }
  68                 ((struct sockaddr_in *)pss_out)->sin_addr.s_addr =
  69                         htonl(((0xFFFFFFFFL >> masklen) ^ 0xFFFFFFFFL));
  70                 return true;
  71         }
  72         return false;
  73 }
  74
  75 /****************************************************************************
  76  Create a struct sockaddr_storage set to the broadcast or network adress from
  77  an incoming sockaddr_storage.
  78 ****************************************************************************/
  79
  80 static void make_bcast_or_net(struct sockaddr_storage *pss_out,
  81                         const struct sockaddr_storage *pss_in,
  82                         const struct sockaddr_storage *nmask,
  83                         bool make_bcast_p)
  84 {
  85         unsigned int i = 0, len = 0;
  86         const char *pmask = NULL;
  87         char *p = NULL;
  88         *pss_out = *pss_in;
  89
  90         /* Set all zero netmask bits to 1. */
  91 #if defined(HAVE_IPV6)
  92         if (pss_in->ss_family == AF_INET6) {
  93                 p = (char *)&((struct sockaddr_in6 *)pss_out)->sin6_addr;
  94                 pmask = (const char *)&((const struct sockaddr_in6 *)nmask)->sin6_addr;
  95                 len = 16;
  96         }
  97 #endif
  98         if (pss_in->ss_family == AF_INET) {
  99                 p = (char *)&((struct sockaddr_in *)pss_out)->sin_addr;
 100                 pmask = (const char *)&((const struct sockaddr_in *)nmask)->sin_addr;
 101                 len = 4;
 102         }
 103
 104         for (i = 0; i < len; i++, p++, pmask++) {
 105                 if (make_bcast_p) {
 106                         *p = (*p & *pmask) | (*pmask ^ 0xff);
 107                 } else {
 108                         /* make_net */
 109                         *p = (*p & *pmask);
 110                 }
 111         }
 112 }
 113
 114 void make_bcast(struct sockaddr_storage *pss_out,
 115                         const struct sockaddr_storage *pss_in,
 116                         const struct sockaddr_storage *nmask)
 117 {
 118         make_bcast_or_net(pss_out, pss_in, nmask, true);
 119 }
 120
 121 void make_net(struct sockaddr_storage *pss_out,
 122                         const struct sockaddr_storage *pss_in,
 123                         const struct sockaddr_storage *nmask)
 124 {
 125         make_bcast_or_net(pss_out, pss_in, nmask, false);
 126 }
 127
 128 #ifdef HAVE_ETHTOOL
 129 static void query_iface_speed_from_name(const char *name, uint64_t *speed)
 130 {
 131         int ret = 0;
 132         struct ethtool_cmd ecmd;
 133         struct ethtool_value edata;
 134         struct ifreq ifr;
 135         int fd;
 136
 137         fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
 138         if (fd == -1) {
 139                 DBG_ERR("Failed to open socket.");
 140                 return;
 141         }
 142
 143         if (strlen(name) >= IF_NAMESIZE) {
 144                 DBG_ERR("Interface name too long.");
 145                 goto done;
 146         }
 147
 148         ZERO_STRUCT(ifr);
 149         strlcpy(ifr.ifr_name, name, IF_NAMESIZE);
 150
 151         ifr.ifr_data = (void *)&edata;
 152         edata.cmd = ETHTOOL_GLINK;
 153         ret = ioctl(fd, SIOCETHTOOL, &ifr);
 154         if (ret == -1) {
 155                 goto done;
 156         }
 157         if (edata.data == 0) {
 158                 /* no link detected */
 159                 *speed = 0;
 160                 goto done;
 161         }
 162
 163         ifr.ifr_data = (void *)&ecmd;
 164         ecmd.cmd = ETHTOOL_GSET;
 165         ret = ioctl(fd, SIOCETHTOOL, &ifr);
 166         if (ret == -1) {
 167                 goto done;
 168         }
 169         *speed = ((uint64_t)ethtool_cmd_speed(&ecmd)) * 1000 * 1000;
 170
 171 done:
 172         (void)close(fd);
 173 }
 174 #endif
 175
 176 /****************************************************************************
 177  Try the "standard" getifaddrs/freeifaddrs interfaces.
 178  Also gets IPv6 interfaces.
 179 ****************************************************************************/
 180
 181 /****************************************************************************
 182  Get the netmask address for a local interface.
 183 ****************************************************************************/
 184
 185 static int _get_interfaces(TALLOC_CTX *mem_ctx, struct iface_struct **pifaces)
 186 {
 187         struct iface_struct *ifaces;
 188         struct ifaddrs *iflist = NULL;
 189         struct ifaddrs *ifptr = NULL;
 190         int count;
 191         int total = 0;
 192         size_t copy_size;
 193
 194         if (getifaddrs(&iflist) < 0) {
 195                 return -1;
 196         }
 197
 198         count = 0;
 199         for (ifptr = iflist; ifptr != NULL; ifptr = ifptr->ifa_next) {
 200                 if (!ifptr->ifa_addr || !ifptr->ifa_netmask) {
 201                         continue;
 202                 }
 203                 if (!(ifptr->ifa_flags & IFF_UP)) {
 204                         continue;
 205                 }
 206                 count += 1;
 207         }
 208
 209         ifaces = talloc_array(mem_ctx, struct iface_struct, count);
 210         if (ifaces == NULL) {
 211                 errno = ENOMEM;
 212                 return -1;
 213         }
 214
 215         /* Loop through interfaces, looking for given IP address */
 216         for (ifptr = iflist; ifptr != NULL; ifptr = ifptr->ifa_next) {
 217                 uint64_t if_speed = 1000 * 1000 * 1000; /* 1Gbps */
 218
 219                 if (!ifptr->ifa_addr || !ifptr->ifa_netmask) {
 220                         continue;
 221                 }
 222
 223                 /* Check the interface is up. */
 224                 if (!(ifptr->ifa_flags & IFF_UP)) {
 225                         continue;
 226                 }
 227
 228                 memset(&ifaces[total], '\0', sizeof(ifaces[total]));
 229
 230                 copy_size = sizeof(struct sockaddr_in);
 231
 232                 ifaces[total].flags = ifptr->ifa_flags;
 233
 234 #if defined(HAVE_IPV6)
 235                 if (ifptr->ifa_addr->sa_family == AF_INET6) {
 236                         copy_size = sizeof(struct sockaddr_in6);
 237                 }
 238 #endif
 239
 240                 memcpy(&ifaces[total].ip, ifptr->ifa_addr, copy_size);
 241                 memcpy(&ifaces[total].netmask, ifptr->ifa_netmask, copy_size);
 242
 243                 /* calculate broadcast address */
 244 #if defined(HAVE_IPV6)
 245                 if (ifptr->ifa_addr->sa_family == AF_INET6) {
 246                         struct sockaddr_in6 *sin6 =
 247                                 (struct sockaddr_in6 *)ifptr->ifa_addr;
 248                         struct in6_addr *in6 =
 249                                 (struct in6_addr *)&sin6->sin6_addr;
 250
 251                         if (IN6_IS_ADDR_LINKLOCAL(in6) || IN6_IS_ADDR_V4COMPAT(in6)) {
 252                                 continue;
 253                         }
 254                         /* IPv6 does not have broadcast it uses multicast. */
 255                         memset(&ifaces[total].bcast, '\0', copy_size);
 256                 } else
 257 #endif
 258                 if (ifaces[total].flags & (IFF_BROADCAST|IFF_LOOPBACK)) {
 259                         make_bcast(&ifaces[total].bcast,
 260                                 &ifaces[total].ip,
 261                                 &ifaces[total].netmask);
 262                 } else if ((ifaces[total].flags & IFF_POINTOPOINT) &&
 263                                ifptr->ifa_dstaddr ) {
 264                         memcpy(&ifaces[total].bcast,
 265                                 ifptr->ifa_dstaddr,
 266                                 copy_size);
 267                 } else {
 268                         continue;
 269                 }
 270
 271                 ifaces[total].if_index = if_nametoindex(ifptr->ifa_name);
 272                 if (ifaces[total].if_index == 0) {
 273                         DBG_ERR("Failed to retrieve interface index for '%s': "
 274                                 "%s\n", ifptr->ifa_name, strerror(errno));
 275                 }
 276
 277 #ifdef HAVE_ETHTOOL
 278                 query_iface_speed_from_name(ifptr->ifa_name, &if_speed);
 279 #endif
 280                 ifaces[total].linkspeed = if_speed;
 281                 ifaces[total].capability = FSCTL_NET_IFACE_NONE_CAPABLE;
 282
 283                 if (strlcpy(ifaces[total].name, ifptr->ifa_name,
 284                         sizeof(ifaces[total].name)) >=
 285                                 sizeof(ifaces[total].name)) {
 286                         /* Truncation ! Ignore. */
 287                         continue;
 288                 }
 289                 total++;
 290         }
 291
 292         freeifaddrs(iflist);
 293
 294         *pifaces = ifaces;
 295         return total;
 296 }
 297
 298 static int iface_comp(struct iface_struct *i1, struct iface_struct *i2)
 299 {
 300         int r;
 301
 302 #if defined(HAVE_IPV6)
 303         /*
 304          * If we have IPv6 - sort these interfaces lower
 305          * than any IPv4 ones.
 306          */
 307         if (i1->ip.ss_family == AF_INET6 &&
 308                         i2->ip.ss_family == AF_INET) {
 309                 return -1;
 310         } else if (i1->ip.ss_family == AF_INET &&
 311                         i2->ip.ss_family == AF_INET6) {
 312                 return 1;
 313         }
 314
 315         if (i1->ip.ss_family == AF_INET6) {
 316                 struct sockaddr_in6 *s1 = (struct sockaddr_in6 *)&i1->ip;
 317                 struct sockaddr_in6 *s2 = (struct sockaddr_in6 *)&i2->ip;
 318
 319                 r = memcmp(&s1->sin6_addr,
 320                                 &s2->sin6_addr,
 321                                 sizeof(struct in6_addr));
 322                 if (r) {
 323                         return r;
 324                 }
 325
 326                 s1 = (struct sockaddr_in6 *)&i1->netmask;
 327                 s2 = (struct sockaddr_in6 *)&i2->netmask;
 328
 329                 r = memcmp(&s1->sin6_addr,
 330                                 &s2->sin6_addr,
 331                                 sizeof(struct in6_addr));
 332                 if (r) {
 333                         return r;
 334                 }
 335         }
 336 #endif
 337
 338         /* AIX uses __ss_family instead of ss_family inside of
 339            sockaddr_storage. Instead of trying to figure out which field to
 340            use, we can just cast it to a sockaddr.
 341          */
 342
 343         if (((struct sockaddr *)&i1->ip)->sa_family == AF_INET) {
 344                 struct sockaddr_in *s1 = (struct sockaddr_in *)&i1->ip;
 345                 struct sockaddr_in *s2 = (struct sockaddr_in *)&i2->ip;
 346
 347                 r = ntohl(s1->sin_addr.s_addr) -
 348                         ntohl(s2->sin_addr.s_addr);
 349                 if (r) {
 350                         return r;
 351                 }
 352
 353                 s1 = (struct sockaddr_in *)&i1->netmask;
 354                 s2 = (struct sockaddr_in *)&i2->netmask;
 355
 356                 return ntohl(s1->sin_addr.s_addr) -
 357                         ntohl(s2->sin_addr.s_addr);
 358         }
 359         return 0;
 360 }
 361
 362 /* this wrapper is used to remove duplicates from the interface list generated
 363    above */
 364 int get_interfaces(TALLOC_CTX *mem_ctx, struct iface_struct **pifaces)
 365 {
 366         struct iface_struct *ifaces;
 367         int total, i, j;
 368
 369         total = _get_interfaces(mem_ctx, &ifaces);
 370         /* If we have an error, no interface or just one we can leave */
 371         if (total <= 1) {
 372                 return total;
 373         }
 374
 375         /* now we need to remove duplicates */
 376         TYPESAFE_QSORT(ifaces, total, iface_comp);
 377
 378         for (i=1;i<total;) {
 379                 if (iface_comp(&ifaces[i-1], &ifaces[i]) == 0) {
 380                         for (j=i-1;j<total-1;j++) {
 381                                 ifaces[j] = ifaces[j+1];
 382                         }
 383                         total--;
 384                 } else {
 385                         i++;
 386                 }
 387         }
 388
 389         *pifaces = ifaces;
 390         return total;
 391 }