external/bsd/bind/dist/lib/isc/unix/ifiter_sysctl.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
   5  * Copyright (C) 1999-2003  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_sysctl.c,v 1.25 2007/06/19 23:47:18 tbox Exp */
  21
  22 /*! \file
  23  * \brief
  24  * Obtain the list of network interfaces using sysctl.
  25  * See TCP/IP Illustrated Volume 2, sections 19.8, 19.14,
  26  * and 19.16.
  27  */
  28
  29 #include <sys/param.h>
  30 #include <sys/sysctl.h>
  31
  32 #include <net/route.h>
  33 #include <net/if_dl.h>
  34
  35 /* XXX what about Alpha? */
  36 #ifdef sgi
  37 #define ROUNDUP(a) ((a) > 0 ? \
  38                 (1 + (((a) - 1) | (sizeof(__uint64_t) - 1))) : \
  39                 sizeof(__uint64_t))
  40 #else
  41 #define ROUNDUP(a) ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) \
  42                     : sizeof(long))
  43 #endif
  44
  45 #define IFITER_MAGIC            ISC_MAGIC('I', 'F', 'I', 'S')
  46 #define VALID_IFITER(t)         ISC_MAGIC_VALID(t, IFITER_MAGIC)
  47
  48 struct isc_interfaceiter {
  49         unsigned int            magic;          /* Magic number. */
  50         isc_mem_t               *mctx;
  51         void                    *buf;           /* Buffer for sysctl data. */
  52         unsigned int            bufsize;        /* Bytes allocated. */
  53         unsigned int            bufused;        /* Bytes used. */
  54         unsigned int            pos;            /* Current offset in
  55                                                    sysctl data. */
  56         isc_interface_t         current;        /* Current interface data. */
  57         isc_result_t            result;         /* Last result code. */
  58 };
  59
  60 static int mib[6] = {
  61         CTL_NET,
  62         PF_ROUTE,
  63         0,
  64         0,                      /* Any address family. */
  65         NET_RT_IFLIST,
  66         0                       /* Flags. */
  67 };
  68
  69 isc_result_t
  70 isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
  71         isc_interfaceiter_t *iter;
  72         isc_result_t result;
  73         size_t bufsize;
  74         size_t bufused;
  75         char strbuf[ISC_STRERRORSIZE];
  76
  77         REQUIRE(mctx != NULL);
  78         REQUIRE(iterp != NULL);
  79         REQUIRE(*iterp == NULL);
  80
  81         iter = isc_mem_get(mctx, sizeof(*iter));
  82         if (iter == NULL)
  83                 return (ISC_R_NOMEMORY);
  84
  85         iter->mctx = mctx;
  86         iter->buf = 0;
  87
  88         /*
  89          * Determine the amount of memory needed.
  90          */
  91         bufsize = 0;
  92         if (sysctl(mib, 6, NULL, &bufsize, NULL, (size_t) 0) < 0) {
  93                 isc__strerror(errno, strbuf, sizeof(strbuf));
  94                 UNEXPECTED_ERROR(__FILE__, __LINE__,
  95                                  isc_msgcat_get(isc_msgcat,
  96                                                 ISC_MSGSET_IFITERSYSCTL,
  97                                                 ISC_MSG_GETIFLISTSIZE,
  98                                                 "getting interface "
  99                                                 "list size: sysctl: %s"),
 100                                  strbuf);
 101                 result = ISC_R_UNEXPECTED;
 102                 goto failure;
 103         }
 104         iter->bufsize = bufsize;
 105
 106         iter->buf = isc_mem_get(iter->mctx, iter->bufsize);
 107         if (iter->buf == NULL) {
 108                 result = ISC_R_NOMEMORY;
 109                 goto failure;
 110         }
 111
 112         bufused = bufsize;
 113         if (sysctl(mib, 6, iter->buf, &bufused, NULL, (size_t) 0) < 0) {
 114                 isc__strerror(errno, strbuf, sizeof(strbuf));
 115                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 116                                  isc_msgcat_get(isc_msgcat,
 117                                                 ISC_MSGSET_IFITERSYSCTL,
 118                                                 ISC_MSG_GETIFLIST,
 119                                                 "getting interface list: "
 120                                                 "sysctl: %s"),
 121                                  strbuf);
 122                 result = ISC_R_UNEXPECTED;
 123                 goto failure;
 124         }
 125         iter->bufused = bufused;
 126         INSIST(iter->bufused <= iter->bufsize);
 127
 128         /*
 129          * A newly created iterator has an undefined position
 130          * until isc_interfaceiter_first() is called.
 131          */
 132         iter->pos = (unsigned int) -1;
 133         iter->result = ISC_R_FAILURE;
 134
 135         iter->magic = IFITER_MAGIC;
 136         *iterp = iter;
 137         return (ISC_R_SUCCESS);
 138
 139  failure:
 140         if (iter->buf != NULL)
 141                 isc_mem_put(mctx, iter->buf, iter->bufsize);
 142         isc_mem_put(mctx, iter, sizeof(*iter));
 143         return (result);
 144 }
 145
 146 /*
 147  * Get information about the current interface to iter->current.
 148  * If successful, return ISC_R_SUCCESS.
 149  * If the interface has an unsupported address family,
 150  * return ISC_R_IGNORE.  In case of other failure,
 151  * return ISC_R_UNEXPECTED.
 152  */
 153
 154 static isc_result_t
 155 internal_current(isc_interfaceiter_t *iter) {
 156         struct ifa_msghdr *ifam, *ifam_end;
 157
 158         REQUIRE(VALID_IFITER(iter));
 159         REQUIRE (iter->pos < (unsigned int) iter->bufused);
 160
 161         ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
 162         ifam_end = (struct ifa_msghdr *) ((char *) iter->buf + iter->bufused);
 163
 164         if (ifam->ifam_type == RTM_IFINFO) {
 165                 struct if_msghdr *ifm = (struct if_msghdr *) ifam;
 166                 struct sockaddr_dl *sdl = (struct sockaddr_dl *) (ifm + 1);
 167                 unsigned int namelen;
 168
 169                 memset(&iter->current, 0, sizeof(iter->current));
 170
 171                 namelen = sdl->sdl_nlen;
 172                 if (namelen > sizeof(iter->current.name) - 1)
 173                         namelen = sizeof(iter->current.name) - 1;
 174
 175                 memset(iter->current.name, 0, sizeof(iter->current.name));
 176                 memcpy(iter->current.name, sdl->sdl_data, namelen);
 177
 178                 iter->current.flags = 0;
 179
 180                 if ((ifam->ifam_flags & IFF_UP) != 0)
 181                         iter->current.flags |= INTERFACE_F_UP;
 182
 183                 if ((ifam->ifam_flags & IFF_POINTOPOINT) != 0)
 184                         iter->current.flags |= INTERFACE_F_POINTTOPOINT;
 185
 186                 if ((ifam->ifam_flags & IFF_LOOPBACK) != 0)
 187                         iter->current.flags |= INTERFACE_F_LOOPBACK;
 188
 189                 /*
 190                  * This is not an interface address.
 191                  * Force another iteration.
 192                  */
 193                 return (ISC_R_IGNORE);
 194         } else if (ifam->ifam_type == RTM_NEWADDR) {
 195                 int i;
 196                 int family;
 197                 struct sockaddr *mask_sa = NULL;
 198                 struct sockaddr *addr_sa = NULL;
 199                 struct sockaddr *dst_sa = NULL;
 200
 201                 struct sockaddr *sa = (struct sockaddr *)(ifam + 1);
 202                 family = sa->sa_family;
 203
 204                 for (i = 0; i < RTAX_MAX; i++)
 205                 {
 206                         if ((ifam->ifam_addrs & (1 << i)) == 0)
 207                                 continue;
 208
 209                         INSIST(sa < (struct sockaddr *) ifam_end);
 210
 211                         switch (i) {
 212                         case RTAX_NETMASK: /* Netmask */
 213                                 mask_sa = sa;
 214                                 break;
 215                         case RTAX_IFA: /* Interface address */
 216                                 addr_sa = sa;
 217                                 break;
 218                         case RTAX_BRD: /* Broadcast or destination address */
 219                                 dst_sa = sa;
 220                                 break;
 221                         }
 222 #ifdef ISC_PLATFORM_HAVESALEN
 223                         sa = (struct sockaddr *)((char*)(sa)
 224                                          + ROUNDUP(sa->sa_len));
 225 #else
 226 #ifdef sgi
 227                         /*
 228                          * Do as the contributed SGI code does.
 229                          */
 230                         sa = (struct sockaddr *)((char*)(sa)
 231                                          + ROUNDUP(_FAKE_SA_LEN_DST(sa)));
 232 #else
 233                         /* XXX untested. */
 234                         sa = (struct sockaddr *)((char*)(sa)
 235                                          + ROUNDUP(sizeof(struct sockaddr)));
 236 #endif
 237 #endif
 238                 }
 239
 240                 if (addr_sa == NULL)
 241                         return (ISC_R_IGNORE);
 242
 243                 family = addr_sa->sa_family;
 244                 if (family != AF_INET && family != AF_INET6)
 245                         return (ISC_R_IGNORE);
 246
 247                 iter->current.af = family;
 248
 249                 get_addr(family, &iter->current.address, addr_sa,
 250                          iter->current.name);
 251
 252                 if (mask_sa != NULL)
 253                         get_addr(family, &iter->current.netmask, mask_sa,
 254                                  iter->current.name);
 255
 256                 if (dst_sa != NULL &&
 257                     (iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0)
 258                         get_addr(family, &iter->current.dstaddress, dst_sa,
 259                                  iter->current.name);
 260
 261                 return (ISC_R_SUCCESS);
 262         } else {
 263                 printf(isc_msgcat_get(isc_msgcat, ISC_MSGSET_IFITERSYSCTL,
 264                                       ISC_MSG_UNEXPECTEDTYPE,
 265                                       "warning: unexpected interface list "
 266                                       "message type\n"));
 267                 return (ISC_R_IGNORE);
 268         }
 269 }
 270
 271 /*
 272  * Step the iterator to the next interface.  Unlike
 273  * isc_interfaceiter_next(), this may leave the iterator
 274  * positioned on an interface that will ultimately
 275  * be ignored.  Return ISC_R_NOMORE if there are no more
 276  * interfaces, otherwise ISC_R_SUCCESS.
 277  */
 278 static isc_result_t
 279 internal_next(isc_interfaceiter_t *iter) {
 280         struct ifa_msghdr *ifam;
 281         REQUIRE (iter->pos < (unsigned int) iter->bufused);
 282
 283         ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
 284
 285         iter->pos += ifam->ifam_msglen;
 286
 287         if (iter->pos >= iter->bufused)
 288                 return (ISC_R_NOMORE);
 289
 290         return (ISC_R_SUCCESS);
 291 }
 292
 293 static void
 294 internal_destroy(isc_interfaceiter_t *iter) {
 295         UNUSED(iter); /* Unused. */
 296         /*
 297          * Do nothing.
 298          */
 299 }
 300
 301 static
 302 void internal_first(isc_interfaceiter_t *iter) {
 303         iter->pos = 0;
 304 }