zebra/if_ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Interface looking up by ioctl ().
   4  * Copyright (C) 1997, 98 Kunihiro Ishiguro
   5  */
   6
   7 #include <zebra.h>
   8
   9 #ifdef OPEN_BSD
  10
  11 #include "if.h"
  12 #include "sockunion.h"
  13 #include "prefix.h"
  14 #include "ioctl.h"
  15 #include "connected.h"
  16 #include "memory.h"
  17 #include "log.h"
  18 #include "vrf.h"
  19 #include "vty.h"
  20 #include "lib_errors.h"
  21
  22 #include "zebra/interface.h"
  23 #include "zebra/rib.h"
  24 #include "zebra/rt.h"
  25 #include "zebra/zebra_errors.h"
  26
  27 #include <ifaddrs.h>
  28
  29 /* Interface looking up using infamous SIOCGIFCONF. */
  30 static int interface_list_ioctl(void)
  31 {
  32         int ret;
  33         int sock;
  34 #define IFNUM_BASE 32
  35         int ifnum;
  36         struct ifreq *ifreq;
  37         struct ifconf ifconf;
  38         struct interface *ifp;
  39         int n;
  40         int lastlen;
  41
  42         /* Normally SIOCGIFCONF works with AF_INET socket. */
  43         sock = socket(AF_INET, SOCK_DGRAM, 0);
  44         if (sock < 0) {
  45                 flog_err_sys(EC_LIB_SOCKET,
  46                              "Can't make AF_INET socket stream: %s",
  47                              safe_strerror(errno));
  48                 return -1;
  49         }
  50
  51 /* Set initial ifreq count.  This will be double when SIOCGIFCONF
  52    fail.  Solaris has SIOCGIFNUM. */
  53 #ifdef SIOCGIFNUM
  54         ret = ioctl(sock, SIOCGIFNUM, &ifnum);
  55         if (ret < 0)
  56                 ifnum = IFNUM_BASE;
  57         else
  58                 ifnum++;
  59 #else
  60         ifnum = IFNUM_BASE;
  61 #endif /* SIOCGIFNUM */
  62
  63         ifconf.ifc_buf = NULL;
  64
  65         lastlen = 0;
  66         /* Loop until SIOCGIFCONF success. */
  67         for (;;) {
  68                 ifconf.ifc_len = sizeof(struct ifreq) * ifnum;
  69                 ifconf.ifc_buf =
  70                         XREALLOC(MTYPE_TMP, ifconf.ifc_buf, ifconf.ifc_len);
  71
  72                 ret = ioctl(sock, SIOCGIFCONF, &ifconf);
  73
  74                 if (ret < 0) {
  75                         flog_err_sys(EC_LIB_SYSTEM_CALL, "SIOCGIFCONF: %s",
  76                                      safe_strerror(errno));
  77                         goto end;
  78                 }
  79                 /* Repeatedly get info til buffer fails to grow. */
  80                 if (ifconf.ifc_len > lastlen) {
  81                         lastlen = ifconf.ifc_len;
  82                         ifnum += 10;
  83                         continue;
  84                 }
  85                 /* Success. */
  86                 break;
  87         }
  88
  89         /* Allocate interface. */
  90         ifreq = ifconf.ifc_req;
  91
  92 #ifdef OPEN_BSD
  93         for (n = 0; n < ifconf.ifc_len;) {
  94                 unsigned int size;
  95
  96                 ifreq = (struct ifreq *)((caddr_t)ifconf.ifc_req + n);
  97                 ifp = if_get_by_name(ifreq->ifr_name, VRF_DEFAULT,
  98                                      VRF_DEFAULT_NAME);
  99                 if_add_update(ifp);
 100                 size = ifreq->ifr_addr.sa_len;
 101                 if (size < sizeof(ifreq->ifr_addr))
 102                         size = sizeof(ifreq->ifr_addr);
 103                 size += sizeof(ifreq->ifr_name);
 104                 n += size;
 105         }
 106 #else
 107         for (n = 0; n < ifconf.ifc_len; n += sizeof(struct ifreq)) {
 108                 ifp = if_get_by_name(ifreq->ifr_name, VRF_DEFAULT,
 109                                      VRF_DEFAULT_NAME);
 110                 if_add_update(ifp);
 111                 ifreq++;
 112         }
 113 #endif /* OPEN_BSD */
 114
 115 end:
 116         close(sock);
 117         XFREE(MTYPE_TMP, ifconf.ifc_buf);
 118
 119         return ret;
 120 }
 121
 122 /* Get interface's index by ioctl. */
 123 static int if_get_index(struct interface *ifp)
 124 {
 125         if_set_index(ifp, if_nametoindex(ifp->name));
 126         return ifp->ifindex;
 127 }
 128
 129 #ifdef SIOCGIFHWADDR
 130 static int if_get_hwaddr(struct interface *ifp)
 131 {
 132         int ret;
 133         struct ifreq ifreq;
 134         int i;
 135
 136         strlcpy(ifreq.ifr_name, ifp->name, sizeof(ifreq.ifr_name));
 137         ifreq.ifr_addr.sa_family = AF_INET;
 138
 139         /* Fetch Hardware address if available. */
 140         ret = vrf_if_ioctl(SIOCGIFHWADDR, (caddr_t)&ifreq, ifp->vrf->vrf_id);
 141         if (ret < 0)
 142                 ifp->hw_addr_len = 0;
 143         else {
 144                 memcpy(ifp->hw_addr, ifreq.ifr_hwaddr.sa_data, 6);
 145
 146                 for (i = 0; i < 6; i++)
 147                         if (ifp->hw_addr[i] != 0)
 148                                 break;
 149
 150                 if (i == 6)
 151                         ifp->hw_addr_len = 0;
 152                 else
 153                         ifp->hw_addr_len = 6;
 154         }
 155         return 0;
 156 }
 157 #endif /* SIOCGIFHWADDR */
 158
 159 static int if_getaddrs(void)
 160 {
 161         int ret;
 162         struct ifaddrs *ifap;
 163         struct ifaddrs *ifapfree;
 164         struct interface *ifp;
 165         int prefixlen;
 166
 167         ret = getifaddrs(&ifap);
 168         if (ret != 0) {
 169                 flog_err_sys(EC_LIB_SYSTEM_CALL, "getifaddrs(): %s",
 170                              safe_strerror(errno));
 171                 return -1;
 172         }
 173
 174         for (ifapfree = ifap; ifap; ifap = ifap->ifa_next) {
 175                 if (ifap->ifa_addr == NULL) {
 176                         flog_err(
 177                                 EC_LIB_INTERFACE,
 178                                 "%s: nonsensical ifaddr with NULL ifa_addr, ifname %s",
 179                                 __func__,
 180                                 (ifap->ifa_name ? ifap->ifa_name : "(null)"));
 181                         continue;
 182                 }
 183
 184                 ifp = if_lookup_by_name(ifap->ifa_name, VRF_DEFAULT);
 185                 if (ifp == NULL) {
 186                         flog_err(EC_LIB_INTERFACE,
 187                                  "%s: Can't lookup interface %s", __func__,
 188                                  ifap->ifa_name);
 189                         continue;
 190                 }
 191
 192                 if (ifap->ifa_addr->sa_family == AF_INET) {
 193                         struct sockaddr_in *addr;
 194                         struct sockaddr_in *mask;
 195                         struct sockaddr_in *dest;
 196                         struct in_addr *dest_pnt;
 197                         int flags = 0;
 198
 199                         addr = (struct sockaddr_in *)ifap->ifa_addr;
 200                         mask = (struct sockaddr_in *)ifap->ifa_netmask;
 201                         prefixlen = ip_masklen(mask->sin_addr);
 202
 203                         dest_pnt = NULL;
 204
 205                         if (if_is_pointopoint(ifp) && ifap->ifa_dstaddr
 206                             && !IPV4_ADDR_SAME(&addr->sin_addr,
 207                                                &((struct sockaddr_in *)
 208                                                          ifap->ifa_dstaddr)
 209                                                         ->sin_addr)) {
 210                                 dest = (struct sockaddr_in *)ifap->ifa_dstaddr;
 211                                 dest_pnt = &dest->sin_addr;
 212                                 flags = ZEBRA_IFA_PEER;
 213                         } else if (ifap->ifa_broadaddr
 214                                    && !IPV4_ADDR_SAME(
 215                                               &addr->sin_addr,
 216                                               &((struct sockaddr_in *)
 217                                                         ifap->ifa_broadaddr)
 218                                                        ->sin_addr)) {
 219                                 dest = (struct sockaddr_in *)
 220                                                ifap->ifa_broadaddr;
 221                                 dest_pnt = &dest->sin_addr;
 222                         }
 223
 224                         connected_add_ipv4(ifp, flags, &addr->sin_addr,
 225                                            prefixlen, dest_pnt, NULL,
 226                                            METRIC_MAX);
 227                 }
 228                 if (ifap->ifa_addr->sa_family == AF_INET6) {
 229                         struct sockaddr_in6 *addr;
 230                         struct sockaddr_in6 *mask;
 231                         int flags = 0;
 232
 233                         addr = (struct sockaddr_in6 *)ifap->ifa_addr;
 234                         mask = (struct sockaddr_in6 *)ifap->ifa_netmask;
 235                         prefixlen = ip6_masklen(mask->sin6_addr);
 236
 237 #if defined(KAME)
 238                         if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
 239                                 addr->sin6_scope_id =
 240                                         ntohs(*(uint16_t *)&addr->sin6_addr
 241                                                        .s6_addr[2]);
 242                                 addr->sin6_addr.s6_addr[2] =
 243                                         addr->sin6_addr.s6_addr[3] = 0;
 244                         }
 245 #endif
 246
 247                         connected_add_ipv6(ifp, flags, &addr->sin6_addr, NULL,
 248                                            prefixlen, NULL, METRIC_MAX);
 249                 }
 250         }
 251
 252         freeifaddrs(ifapfree);
 253
 254         return 0;
 255 }
 256
 257 /* Fetch interface information via ioctl(). */
 258 static void interface_info_ioctl()
 259 {
 260         struct vrf *vrf = vrf_lookup_by_id(VRF_DEFAULT);
 261         struct interface *ifp;
 262
 263         FOR_ALL_INTERFACES (vrf, ifp) {
 264                 if_get_index(ifp);
 265 #ifdef SIOCGIFHWADDR
 266                 if_get_hwaddr(ifp);
 267 #endif /* SIOCGIFHWADDR */
 268                 if_get_flags(ifp);
 269                 if_get_mtu(ifp);
 270                 if_get_metric(ifp);
 271         }
 272 }
 273
 274 /* Lookup all interface information. */
 275 void interface_list(struct zebra_ns *zns)
 276 {
 277
 278         zlog_info("%s: NS %u", __func__, zns->ns_id);
 279
 280 /* Linux can do both proc & ioctl, ioctl is the only way to get
 281    interface aliases in 2.2 series kernels. */
 282 #ifdef HAVE_PROC_NET_DEV
 283         interface_list_proc();
 284 #endif /* HAVE_PROC_NET_DEV */
 285         interface_list_ioctl();
 286
 287         /* After listing is done, get index, address, flags and other
 288            interface's information. */
 289         interface_info_ioctl();
 290
 291         if_getaddrs();
 292
 293 #if defined(HAVE_PROC_NET_IF_INET6)
 294         /* Linux provides interface's IPv6 address via
 295            /proc/net/if_inet6. */
 296         ifaddr_proc_ipv6();
 297 #endif /* HAVE_PROC_NET_IF_INET6 */
 298 }
 299
 300 #endif /* OPEN_BSD */