contrib/bind-9.3/lib/isc/unix/ifiter_sysctl.c

   1 /*
   2  * Copyright (C) 2004, 2005  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1999-2003  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: ifiter_sysctl.c,v 1.14.12.9 2005/03/17 03:58:33 marka Exp $ */
  19
  20 /*
  21  * Obtain the list of network interfaces using sysctl.
  22  * See TCP/IP Illustrated Volume 2, sections 19.8, 19.14,
  23  * and 19.16.
  24  */
  25
  26 #include <sys/param.h>
  27 #include <sys/sysctl.h>
  28
  29 #include <net/route.h>
  30 #include <net/if_dl.h>
  31
  32 /* XXX what about Alpha? */
  33 #ifdef sgi
  34 #define ROUNDUP(a) ((a) > 0 ? \
  35                 (1 + (((a) - 1) | (sizeof(__uint64_t) - 1))) : \
  36                 sizeof(__uint64_t))
  37 #else
  38 #define ROUNDUP(a) ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) \
  39                     : sizeof(long))
  40 #endif
  41
  42 #define IFITER_MAGIC            ISC_MAGIC('I', 'F', 'I', 'S')
  43 #define VALID_IFITER(t)         ISC_MAGIC_VALID(t, IFITER_MAGIC)
  44
  45 struct isc_interfaceiter {
  46         unsigned int            magic;          /* Magic number. */
  47         isc_mem_t               *mctx;
  48         void                    *buf;           /* Buffer for sysctl data. */
  49         unsigned int            bufsize;        /* Bytes allocated. */
  50         unsigned int            bufused;        /* Bytes used. */
  51         unsigned int            pos;            /* Current offset in
  52                                                    sysctl data. */
  53         isc_interface_t         current;        /* Current interface data. */
  54         isc_result_t            result;         /* Last result code. */
  55 };
  56
  57 static int mib[6] = {
  58         CTL_NET,
  59         PF_ROUTE,
  60         0,
  61         0,                      /* Any address family. */
  62         NET_RT_IFLIST,
  63         0                       /* Flags. */
  64 };
  65
  66 isc_result_t
  67 isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
  68         isc_interfaceiter_t *iter;
  69         isc_result_t result;
  70         size_t bufsize;
  71         size_t bufused;
  72         char strbuf[ISC_STRERRORSIZE];
  73
  74         REQUIRE(mctx != NULL);
  75         REQUIRE(iterp != NULL);
  76         REQUIRE(*iterp == NULL);
  77
  78         iter = isc_mem_get(mctx, sizeof(*iter));
  79         if (iter == NULL)
  80                 return (ISC_R_NOMEMORY);
  81
  82         iter->mctx = mctx;
  83         iter->buf = 0;
  84
  85         /*
  86          * Determine the amount of memory needed.
  87          */
  88         bufsize = 0;
  89         if (sysctl(mib, 6, NULL, &bufsize, NULL, (size_t) 0) < 0) {
  90                 isc__strerror(errno, strbuf, sizeof(strbuf));
  91                 UNEXPECTED_ERROR(__FILE__, __LINE__,
  92                                  isc_msgcat_get(isc_msgcat,
  93                                                 ISC_MSGSET_IFITERSYSCTL,
  94                                                 ISC_MSG_GETIFLISTSIZE,
  95                                                 "getting interface "
  96                                                 "list size: sysctl: %s"),
  97                                  strbuf);
  98                 result = ISC_R_UNEXPECTED;
  99                 goto failure;
 100         }
 101         iter->bufsize = bufsize;
 102
 103         iter->buf = isc_mem_get(iter->mctx, iter->bufsize);
 104         if (iter->buf == NULL) {
 105                 result = ISC_R_NOMEMORY;
 106                 goto failure;
 107         }
 108
 109         bufused = bufsize;
 110         if (sysctl(mib, 6, iter->buf, &bufused, NULL, (size_t) 0) < 0) {
 111                 isc__strerror(errno, strbuf, sizeof(strbuf));
 112                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 113                                  isc_msgcat_get(isc_msgcat,
 114                                                 ISC_MSGSET_IFITERSYSCTL,
 115                                                 ISC_MSG_GETIFLIST,
 116                                                 "getting interface list: "
 117                                                 "sysctl: %s"),
 118                                  strbuf);
 119                 result = ISC_R_UNEXPECTED;
 120                 goto failure;
 121         }
 122         iter->bufused = bufused;
 123         INSIST(iter->bufused <= iter->bufsize);
 124
 125         /*
 126          * A newly created iterator has an undefined position
 127          * until isc_interfaceiter_first() is called.
 128          */
 129         iter->pos = (unsigned int) -1;
 130         iter->result = ISC_R_FAILURE;
 131
 132         iter->magic = IFITER_MAGIC;
 133         *iterp = iter;
 134         return (ISC_R_SUCCESS);
 135
 136  failure:
 137         if (iter->buf != NULL)
 138                 isc_mem_put(mctx, iter->buf, iter->bufsize);
 139         isc_mem_put(mctx, iter, sizeof(*iter));
 140         return (result);
 141 }
 142
 143 /*
 144  * Get information about the current interface to iter->current.
 145  * If successful, return ISC_R_SUCCESS.
 146  * If the interface has an unsupported address family,
 147  * return ISC_R_IGNORE.  In case of other failure,
 148  * return ISC_R_UNEXPECTED.
 149  */
 150
 151 static isc_result_t
 152 internal_current(isc_interfaceiter_t *iter) {
 153         struct ifa_msghdr *ifam, *ifam_end;
 154
 155         REQUIRE(VALID_IFITER(iter));
 156         REQUIRE (iter->pos < (unsigned int) iter->bufused);
 157
 158         ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
 159         ifam_end = (struct ifa_msghdr *) ((char *) iter->buf + iter->bufused);
 160
 161         if (ifam->ifam_type == RTM_IFINFO) {
 162                 struct if_msghdr *ifm = (struct if_msghdr *) ifam;
 163                 struct sockaddr_dl *sdl = (struct sockaddr_dl *) (ifm + 1);
 164                 unsigned int namelen;
 165
 166                 memset(&iter->current, 0, sizeof(iter->current));
 167
 168                 namelen = sdl->sdl_nlen;
 169                 if (namelen > sizeof(iter->current.name) - 1)
 170                         namelen = sizeof(iter->current.name) - 1;
 171
 172                 memset(iter->current.name, 0, sizeof(iter->current.name));
 173                 memcpy(iter->current.name, sdl->sdl_data, namelen);
 174
 175                 iter->current.flags = 0;
 176
 177                 if ((ifam->ifam_flags & IFF_UP) != 0)
 178                         iter->current.flags |= INTERFACE_F_UP;
 179
 180                 if ((ifam->ifam_flags & IFF_POINTOPOINT) != 0)
 181                         iter->current.flags |= INTERFACE_F_POINTTOPOINT;
 182
 183                 if ((ifam->ifam_flags & IFF_LOOPBACK) != 0)
 184                         iter->current.flags |= INTERFACE_F_LOOPBACK;
 185
 186                 /*
 187                  * This is not an interface address.
 188                  * Force another iteration.
 189                  */
 190                 return (ISC_R_IGNORE);
 191         } else if (ifam->ifam_type == RTM_NEWADDR) {
 192                 int i;
 193                 int family;
 194                 struct sockaddr *mask_sa = NULL;
 195                 struct sockaddr *addr_sa = NULL;
 196                 struct sockaddr *dst_sa = NULL;
 197
 198                 struct sockaddr *sa = (struct sockaddr *)(ifam + 1);
 199                 family = sa->sa_family;
 200
 201                 for (i = 0; i < RTAX_MAX; i++)
 202                 {
 203                         if ((ifam->ifam_addrs & (1 << i)) == 0)
 204                                 continue;
 205
 206                         INSIST(sa < (struct sockaddr *) ifam_end);
 207
 208                         switch (i) {
 209                         case RTAX_NETMASK: /* Netmask */
 210                                 mask_sa = sa;
 211                                 break;
 212                         case RTAX_IFA: /* Interface address */
 213                                 addr_sa = sa;
 214                                 break;
 215                         case RTAX_BRD: /* Broadcast or destination address */
 216                                 dst_sa = sa;
 217                                 break;
 218                         }
 219 #ifdef ISC_PLATFORM_HAVESALEN
 220                         sa = (struct sockaddr *)((char*)(sa)
 221                                          + ROUNDUP(sa->sa_len));
 222 #else
 223 #ifdef sgi
 224                         /*
 225                          * Do as the contributed SGI code does.
 226                          */
 227                         sa = (struct sockaddr *)((char*)(sa)
 228                                          + ROUNDUP(_FAKE_SA_LEN_DST(sa)));
 229 #else
 230                         /* XXX untested. */
 231                         sa = (struct sockaddr *)((char*)(sa)
 232                                          + ROUNDUP(sizeof(struct sockaddr)));
 233 #endif
 234 #endif
 235                 }
 236
 237                 if (addr_sa == NULL)
 238                         return (ISC_R_IGNORE);
 239
 240                 family = addr_sa->sa_family;
 241                 if (family != AF_INET && family != AF_INET6)
 242                         return (ISC_R_IGNORE);
 243
 244                 iter->current.af = family;
 245
 246                 get_addr(family, &iter->current.address, addr_sa,
 247                          iter->current.name);
 248
 249                 if (mask_sa != NULL)
 250                         get_addr(family, &iter->current.netmask, mask_sa,
 251                                  iter->current.name);
 252
 253                 if (dst_sa != NULL &&
 254                     (iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0)
 255                         get_addr(family, &iter->current.dstaddress, dst_sa,
 256                                  iter->current.name);
 257
 258                 return (ISC_R_SUCCESS);
 259         } else {
 260                 printf(isc_msgcat_get(isc_msgcat, ISC_MSGSET_IFITERSYSCTL,
 261                                       ISC_MSG_UNEXPECTEDTYPE,
 262                                       "warning: unexpected interface list "
 263                                       "message type\n"));
 264                 return (ISC_R_IGNORE);
 265         }
 266 }
 267
 268 /*
 269  * Step the iterator to the next interface.  Unlike
 270  * isc_interfaceiter_next(), this may leave the iterator
 271  * positioned on an interface that will ultimately
 272  * be ignored.  Return ISC_R_NOMORE if there are no more
 273  * interfaces, otherwise ISC_R_SUCCESS.
 274  */
 275 static isc_result_t
 276 internal_next(isc_interfaceiter_t *iter) {
 277         struct ifa_msghdr *ifam;
 278         REQUIRE (iter->pos < (unsigned int) iter->bufused);
 279
 280         ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
 281
 282         iter->pos += ifam->ifam_msglen;
 283
 284         if (iter->pos >= iter->bufused)
 285                 return (ISC_R_NOMORE);
 286
 287         return (ISC_R_SUCCESS);
 288 }
 289
 290 static void
 291 internal_destroy(isc_interfaceiter_t *iter) {
 292         UNUSED(iter); /* Unused. */
 293         /*
 294          * Do nothing.
 295          */
 296 }
 297
 298 static
 299 void internal_first(isc_interfaceiter_t *iter) {
 300         iter->pos = 0;
 301 }