contrib/bind-9.2.4rc7/lib/isc/unix/ifiter_sysctl.c

   1 /*
   2  * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1999-2001  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 1.14.2.1 2004/03/09 06:12:10 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         REQUIRE(mctx != NULL);
  73         REQUIRE(iterp != NULL);
  74         REQUIRE(*iterp == NULL);
  75
  76         iter = isc_mem_get(mctx, sizeof(*iter));
  77         if (iter == NULL)
  78                 return (ISC_R_NOMEMORY);
  79
  80         iter->mctx = mctx;
  81         iter->buf = 0;
  82
  83         /*
  84          * Determine the amount of memory needed.
  85          */
  86         bufsize = 0;
  87         if (sysctl(mib, 6, NULL, &bufsize, NULL, (size_t) 0) < 0) {
  88                 UNEXPECTED_ERROR(__FILE__, __LINE__,
  89                                  isc_msgcat_get(isc_msgcat,
  90                                                 ISC_MSGSET_IFITERSYSCTL,
  91                                                 ISC_MSG_GETIFLISTSIZE,
  92                                                 "getting interface "
  93                                                 "list size: sysctl: %s"),
  94                                  strerror(errno));
  95                 result = ISC_R_UNEXPECTED;
  96                 goto failure;
  97         }
  98         iter->bufsize = bufsize;
  99
 100         iter->buf = isc_mem_get(iter->mctx, iter->bufsize);
 101         if (iter->buf == NULL) {
 102                 result = ISC_R_NOMEMORY;
 103                 goto failure;
 104         }
 105
 106         bufused = bufsize;
 107         if (sysctl(mib, 6, iter->buf, &bufused, NULL, (size_t) 0) < 0) {
 108                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 109                                  isc_msgcat_get(isc_msgcat,
 110                                                 ISC_MSGSET_IFITERSYSCTL,
 111                                                 ISC_MSG_GETIFLIST,
 112                                                 "getting interface list: "
 113                                                 "sysctl: %s"),
 114                                  strerror(errno));
 115                 result = ISC_R_UNEXPECTED;
 116                 goto failure;
 117         }
 118         iter->bufused = bufused;
 119         INSIST(iter->bufused <= iter->bufsize);
 120
 121         /*
 122          * A newly created iterator has an undefined position
 123          * until isc_interfaceiter_first() is called.
 124          */
 125         iter->pos = (unsigned int) -1;
 126         iter->result = ISC_R_FAILURE;
 127
 128         iter->magic = IFITER_MAGIC;
 129         *iterp = iter;
 130         return (ISC_R_SUCCESS);
 131
 132  failure:
 133         if (iter->buf != NULL)
 134                 isc_mem_put(mctx, iter->buf, iter->bufsize);
 135         isc_mem_put(mctx, iter, sizeof *iter);
 136         return (result);
 137 }
 138
 139 /*
 140  * Get information about the current interface to iter->current.
 141  * If successful, return ISC_R_SUCCESS.
 142  * If the interface has an unsupported address family,
 143  * return ISC_R_IGNORE.  In case of other failure,
 144  * return ISC_R_UNEXPECTED.
 145  */
 146
 147 static isc_result_t
 148 internal_current(isc_interfaceiter_t *iter) {
 149         struct ifa_msghdr *ifam, *ifam_end;
 150
 151         REQUIRE(VALID_IFITER(iter));
 152         REQUIRE (iter->pos < (unsigned int) iter->bufused);
 153
 154         ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
 155         ifam_end = (struct ifa_msghdr *) ((char *) iter->buf + iter->bufused);
 156
 157         if (ifam->ifam_type == RTM_IFINFO) {
 158                 struct if_msghdr *ifm = (struct if_msghdr *) ifam;
 159                 struct sockaddr_dl *sdl = (struct sockaddr_dl *) (ifm + 1);
 160                 unsigned int namelen;
 161
 162                 memset(&iter->current, 0, sizeof(iter->current));
 163
 164                 namelen = sdl->sdl_nlen;
 165                 if (namelen > sizeof(iter->current.name) - 1)
 166                         namelen = sizeof(iter->current.name) - 1;
 167
 168                 memset(iter->current.name, 0, sizeof(iter->current.name));
 169                 memcpy(iter->current.name, sdl->sdl_data, namelen);
 170
 171                 iter->current.flags = 0;
 172
 173                 if ((ifam->ifam_flags & IFF_UP) != 0)
 174                         iter->current.flags |= INTERFACE_F_UP;
 175
 176                 if ((ifam->ifam_flags & IFF_POINTOPOINT) != 0)
 177                         iter->current.flags |= INTERFACE_F_POINTTOPOINT;
 178
 179                 if ((ifam->ifam_flags & IFF_LOOPBACK) != 0)
 180                         iter->current.flags |= INTERFACE_F_LOOPBACK;
 181
 182                 /*
 183                  * This is not an interface address.
 184                  * Force another iteration.
 185                  */
 186                 return (ISC_R_IGNORE);
 187         } else if (ifam->ifam_type == RTM_NEWADDR) {
 188                 int i;
 189                 int family;
 190                 struct sockaddr *mask_sa = NULL;
 191                 struct sockaddr *addr_sa = NULL;
 192                 struct sockaddr *dst_sa = NULL;
 193
 194                 struct sockaddr *sa = (struct sockaddr *)(ifam + 1);
 195                 family = sa->sa_family;
 196
 197                 for (i = 0; i < RTAX_MAX; i++)
 198                 {
 199                         if ((ifam->ifam_addrs & (1 << i)) == 0)
 200                                 continue;
 201
 202                         INSIST(sa < (struct sockaddr *) ifam_end);
 203
 204                         switch (i) {
 205                         case RTAX_NETMASK: /* Netmask */
 206                                 mask_sa = sa;
 207                                 break;
 208                         case RTAX_IFA: /* Interface address */
 209                                 addr_sa = sa;
 210                                 break;
 211                         case RTAX_BRD: /* Broadcast or destination address */
 212                                 dst_sa = sa;
 213                                 break;
 214                         }
 215 #ifdef ISC_PLATFORM_HAVESALEN
 216                         sa = (struct sockaddr *)((char*)(sa)
 217                                          + ROUNDUP(sa->sa_len));
 218 #else
 219 #ifdef sgi
 220                         /*
 221                          * Do as the contributed SGI code does.
 222                          */
 223                         sa = (struct sockaddr *)((char*)(sa)
 224                                          + ROUNDUP(_FAKE_SA_LEN_DST(sa)));
 225 #else
 226                         /* XXX untested. */
 227                         sa = (struct sockaddr *)((char*)(sa)
 228                                          + ROUNDUP(sizeof(struct sockaddr)));
 229 #endif
 230 #endif
 231                 }
 232
 233                 if (addr_sa == NULL)
 234                         return (ISC_R_IGNORE);
 235
 236                 family = addr_sa->sa_family;
 237                 if (family != AF_INET) /* XXX IP6 */
 238                         return (ISC_R_IGNORE);
 239
 240                 iter->current.af = family;
 241
 242                 get_addr(family, &iter->current.address, addr_sa);
 243
 244                 if (mask_sa != NULL)
 245                         get_addr(family, &iter->current.netmask, mask_sa);
 246
 247                 if (dst_sa != NULL &&
 248                     (iter->current.flags & IFF_POINTOPOINT) != 0)
 249                         get_addr(family, &iter->current.dstaddress, dst_sa);
 250
 251                 return (ISC_R_SUCCESS);
 252         } else {
 253                 printf(isc_msgcat_get(isc_msgcat, ISC_MSGSET_IFITERSYSCTL,
 254                                       ISC_MSG_UNEXPECTEDTYPE,
 255                                       "warning: unexpected interface list "
 256                                       "message type\n"));
 257                 return (ISC_R_IGNORE);
 258         }
 259 }
 260
 261 /*
 262  * Step the iterator to the next interface.  Unlike
 263  * isc_interfaceiter_next(), this may leave the iterator
 264  * positioned on an interface that will ultimately
 265  * be ignored.  Return ISC_R_NOMORE if there are no more
 266  * interfaces, otherwise ISC_R_SUCCESS.
 267  */
 268 static isc_result_t
 269 internal_next(isc_interfaceiter_t *iter) {
 270         struct ifa_msghdr *ifam;
 271         REQUIRE (iter->pos < (unsigned int) iter->bufused);
 272
 273         ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
 274
 275         iter->pos += ifam->ifam_msglen;
 276
 277         if (iter->pos >= iter->bufused)
 278                 return (ISC_R_NOMORE);
 279
 280         return (ISC_R_SUCCESS);
 281 }
 282
 283 static void
 284 internal_destroy(isc_interfaceiter_t *iter) {
 285         UNUSED(iter); /* Unused. */
 286         /*
 287          * Do nothing.
 288          */
 289 }
 290