zebra/if_ioctl.c

   1 /*
   2  * Interface looking up by ioctl ().
   3  * Copyright (C) 1997, 98 Kunihiro Ishiguro
   4  *
   5  * This file is part of GNU Zebra.
   6  *
   7  * GNU Zebra is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2, or (at your option) any
  10  * later version.
  11  *
  12  * GNU Zebra is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  19  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  20  * 02111-1307, USA.
  21  */
  22
  23 #include <zebra.h>
  24
  25 #include "if.h"
  26 #include "sockunion.h"
  27 #include "prefix.h"
  28 #include "ioctl.h"
  29 #include "connected.h"
  30 #include "memory.h"
  31 #include "zebra_memory.h"
  32 #include "log.h"
  33 #include "vrf.h"
  34 #include "vty.h"
  35
  36 #include "zebra/interface.h"
  37 #include "zebra/rib.h"
  38
  39 #include <ifaddrs.h>
  40
  41 /* Interface looking up using infamous SIOCGIFCONF. */
  42 static int interface_list_ioctl(void)
  43 {
  44         int ret;
  45         int sock;
  46 #define IFNUM_BASE 32
  47         int ifnum;
  48         struct ifreq *ifreq;
  49         struct ifconf ifconf;
  50         struct interface *ifp;
  51         int n;
  52         int lastlen;
  53
  54         /* Normally SIOCGIFCONF works with AF_INET socket. */
  55         sock = socket(AF_INET, SOCK_DGRAM, 0);
  56         if (sock < 0) {
  57                 zlog_warn("Can't make AF_INET socket stream: %s",
  58                           safe_strerror(errno));
  59                 return -1;
  60         }
  61
  62 /* Set initial ifreq count.  This will be double when SIOCGIFCONF
  63    fail.  Solaris has SIOCGIFNUM. */
  64 #ifdef SIOCGIFNUM
  65         ret = ioctl(sock, SIOCGIFNUM, &ifnum);
  66         if (ret < 0)
  67                 ifnum = IFNUM_BASE;
  68         else
  69                 ifnum++;
  70 #else
  71         ifnum = IFNUM_BASE;
  72 #endif /* SIOCGIFNUM */
  73
  74         ifconf.ifc_buf = NULL;
  75
  76         lastlen = 0;
  77         /* Loop until SIOCGIFCONF success. */
  78         for (;;) {
  79                 ifconf.ifc_len = sizeof(struct ifreq) * ifnum;
  80                 ifconf.ifc_buf =
  81                         XREALLOC(MTYPE_TMP, ifconf.ifc_buf, ifconf.ifc_len);
  82
  83                 ret = ioctl(sock, SIOCGIFCONF, &ifconf);
  84
  85                 if (ret < 0) {
  86                         zlog_warn("SIOCGIFCONF: %s", safe_strerror(errno));
  87                         goto end;
  88                 }
  89                 /* Repeatedly get info til buffer fails to grow. */
  90                 if (ifconf.ifc_len > lastlen) {
  91                         lastlen = ifconf.ifc_len;
  92                         ifnum += 10;
  93                         continue;
  94                 }
  95                 /* Success. */
  96                 break;
  97         }
  98
  99         /* Allocate interface. */
 100         ifreq = ifconf.ifc_req;
 101
 102 #ifdef OPEN_BSD
 103         for (n = 0; n < ifconf.ifc_len;) {
 104                 unsigned int size;
 105
 106                 ifreq = (struct ifreq *)((caddr_t)ifconf.ifc_req + n);
 107                 ifp = if_get_by_name_len(
 108                         ifreq->ifr_name,
 109                         strnlen(ifreq->ifr_name, sizeof(ifreq->ifr_name)),
 110                         VRF_DEFAULT, 0);
 111                 if_add_update(ifp);
 112                 size = ifreq->ifr_addr.sa_len;
 113                 if (size < sizeof(ifreq->ifr_addr))
 114                         size = sizeof(ifreq->ifr_addr);
 115                 size += sizeof(ifreq->ifr_name);
 116                 n += size;
 117         }
 118 #else
 119         for (n = 0; n < ifconf.ifc_len; n += sizeof(struct ifreq)) {
 120                 ifp = if_get_by_name_len(
 121                         ifreq->ifr_name,
 122                         strnlen(ifreq->ifr_name, sizeof(ifreq->ifr_name)),
 123                         VRF_DEFAULT, 0);
 124                 if_add_update(ifp);
 125                 ifreq++;
 126         }
 127 #endif /* OPEN_BSD */
 128
 129 end:
 130         close(sock);
 131         XFREE(MTYPE_TMP, ifconf.ifc_buf);
 132
 133         return ret;
 134 }
 135
 136 /* Get interface's index by ioctl. */
 137 static int if_get_index(struct interface *ifp)
 138 {
 139         ifp->ifindex = if_nametoindex(ifp->name);
 140         return ifp->ifindex;
 141 }
 142
 143 #ifdef SIOCGIFHWADDR
 144 static int if_get_hwaddr(struct interface *ifp)
 145 {
 146         int ret;
 147         struct ifreq ifreq;
 148         int i;
 149
 150         strncpy(ifreq.ifr_name, ifp->name, IFNAMSIZ);
 151         ifreq.ifr_addr.sa_family = AF_INET;
 152
 153         /* Fetch Hardware address if available. */
 154         ret = if_ioctl(SIOCGIFHWADDR, (caddr_t)&ifreq);
 155         if (ret < 0)
 156                 ifp->hw_addr_len = 0;
 157         else {
 158                 memcpy(ifp->hw_addr, ifreq.ifr_hwaddr.sa_data, 6);
 159
 160                 for (i = 0; i < 6; i++)
 161                         if (ifp->hw_addr[i] != 0)
 162                                 break;
 163
 164                 if (i == 6)
 165                         ifp->hw_addr_len = 0;
 166                 else
 167                         ifp->hw_addr_len = 6;
 168         }
 169         return 0;
 170 }
 171 #endif /* SIOCGIFHWADDR */
 172
 173 static int if_getaddrs(void)
 174 {
 175         int ret;
 176         struct ifaddrs *ifap;
 177         struct ifaddrs *ifapfree;
 178         struct interface *ifp;
 179         int prefixlen;
 180
 181         ret = getifaddrs(&ifap);
 182         if (ret != 0) {
 183                 zlog_err("getifaddrs(): %s", safe_strerror(errno));
 184                 return -1;
 185         }
 186
 187         for (ifapfree = ifap; ifap; ifap = ifap->ifa_next) {
 188                 if (ifap->ifa_addr == NULL) {
 189                         zlog_err(
 190                                 "%s: nonsensical ifaddr with NULL ifa_addr, ifname %s",
 191                                 __func__,
 192                                 (ifap->ifa_name ? ifap->ifa_name : "(null)"));
 193                         continue;
 194                 }
 195
 196                 ifp = if_lookup_by_name(ifap->ifa_name, VRF_DEFAULT);
 197                 if (ifp == NULL) {
 198                         zlog_err("if_getaddrs(): Can't lookup interface %s\n",
 199                                  ifap->ifa_name);
 200                         continue;
 201                 }
 202
 203                 if (ifap->ifa_addr->sa_family == AF_INET) {
 204                         struct sockaddr_in *addr;
 205                         struct sockaddr_in *mask;
 206                         struct sockaddr_in *dest;
 207                         struct in_addr *dest_pnt;
 208                         int flags = 0;
 209
 210                         addr = (struct sockaddr_in *)ifap->ifa_addr;
 211                         mask = (struct sockaddr_in *)ifap->ifa_netmask;
 212                         prefixlen = ip_masklen(mask->sin_addr);
 213
 214                         dest_pnt = NULL;
 215
 216                         if (ifap->ifa_dstaddr
 217                             && !IPV4_ADDR_SAME(&addr->sin_addr,
 218                                                &((struct sockaddr_in *)
 219                                                          ifap->ifa_dstaddr)
 220                                                         ->sin_addr)) {
 221                                 dest = (struct sockaddr_in *)ifap->ifa_dstaddr;
 222                                 dest_pnt = &dest->sin_addr;
 223                                 flags = ZEBRA_IFA_PEER;
 224                         } else if (ifap->ifa_broadaddr
 225                                    && !IPV4_ADDR_SAME(
 226                                               &addr->sin_addr,
 227                                               &((struct sockaddr_in *)
 228                                                         ifap->ifa_broadaddr)
 229                                                        ->sin_addr)) {
 230                                 dest = (struct sockaddr_in *)
 231                                                ifap->ifa_broadaddr;
 232                                 dest_pnt = &dest->sin_addr;
 233                         }
 234
 235                         connected_add_ipv4(ifp, flags, &addr->sin_addr,
 236                                            prefixlen, dest_pnt, NULL);
 237                 }
 238                 if (ifap->ifa_addr->sa_family == AF_INET6) {
 239                         struct sockaddr_in6 *addr;
 240                         struct sockaddr_in6 *mask;
 241                         struct sockaddr_in6 *dest;
 242                         struct in6_addr *dest_pnt;
 243                         int flags = 0;
 244
 245                         addr = (struct sockaddr_in6 *)ifap->ifa_addr;
 246                         mask = (struct sockaddr_in6 *)ifap->ifa_netmask;
 247                         prefixlen = ip6_masklen(mask->sin6_addr);
 248
 249                         dest_pnt = NULL;
 250
 251                         if (ifap->ifa_dstaddr
 252                             && !IPV6_ADDR_SAME(&addr->sin6_addr,
 253                                                &((struct sockaddr_in6 *)
 254                                                          ifap->ifa_dstaddr)
 255                                                         ->sin6_addr)) {
 256                                 dest = (struct sockaddr_in6 *)ifap->ifa_dstaddr;
 257                                 dest_pnt = &dest->sin6_addr;
 258                                 flags = ZEBRA_IFA_PEER;
 259                         } else if (ifap->ifa_broadaddr
 260                                    && !IPV6_ADDR_SAME(
 261                                               &addr->sin6_addr,
 262                                               &((struct sockaddr_in6 *)
 263                                                         ifap->ifa_broadaddr)
 264                                                        ->sin6_addr)) {
 265                                 dest = (struct sockaddr_in6 *)
 266                                                ifap->ifa_broadaddr;
 267                                 dest_pnt = &dest->sin6_addr;
 268                         }
 269
 270 #if defined(KAME)
 271                         if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
 272                                 addr->sin6_scope_id =
 273                                         ntohs(*(u_int16_t *)&addr->sin6_addr
 274                                                        .s6_addr[2]);
 275                                 addr->sin6_addr.s6_addr[2] =
 276                                         addr->sin6_addr.s6_addr[3] = 0;
 277                         }
 278 #endif
 279
 280                         connected_add_ipv6(ifp, flags, &addr->sin6_addr,
 281                                            prefixlen, dest_pnt, NULL);
 282                 }
 283         }
 284
 285         freeifaddrs(ifapfree);
 286
 287         return 0;
 288 }
 289
 290 /* Fetch interface information via ioctl(). */
 291 static void interface_info_ioctl()
 292 {
 293         struct listnode *node, *nnode;
 294         struct interface *ifp;
 295
 296         for (ALL_LIST_ELEMENTS(vrf_iflist(VRF_DEFAULT), node, nnode, ifp)) {
 297                 if_get_index(ifp);
 298 #ifdef SIOCGIFHWADDR
 299                 if_get_hwaddr(ifp);
 300 #endif /* SIOCGIFHWADDR */
 301                 if_get_flags(ifp);
 302                 if_get_mtu(ifp);
 303                 if_get_metric(ifp);
 304         }
 305 }
 306
 307 /* Lookup all interface information. */
 308 void interface_list(struct zebra_ns *zns)
 309 {
 310
 311         zlog_info("interface_list: NS %u", zns->ns_id);
 312
 313 /* Linux can do both proc & ioctl, ioctl is the only way to get
 314    interface aliases in 2.2 series kernels. */
 315 #ifdef HAVE_PROC_NET_DEV
 316         interface_list_proc();
 317 #endif /* HAVE_PROC_NET_DEV */
 318         interface_list_ioctl();
 319
 320         /* After listing is done, get index, address, flags and other
 321            interface's information. */
 322         interface_info_ioctl();
 323
 324         if_getaddrs();
 325
 326 #if defined(HAVE_PROC_NET_IF_INET6)
 327         /* Linux provides interface's IPv6 address via
 328            /proc/net/if_inet6. */
 329         ifaddr_proc_ipv6();
 330 #endif /* HAVE_PROC_NET_IF_INET6 */
 331 }