dist/ntp/libisc/ifiter_sysctl.c

   1 /*      $NetBSD: ifiter_sysctl.c,v 1.3 2004/02/26 18:17:13 drochner Exp $       */
   2
   3 /*
   4  * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   5  * Copyright (C) 1999-2003  Internet Software Consortium.
   6  *
   7  * Permission to use, copy, modify, and 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 1.14.12.7 2004/03/08 09:04:56 marka Exp */
  21
  22 /*
  23  * Obtain the list of network interfaces using sysctl.
  24  * See TCP/IP Illustrated Volume 2, sections 19.8, 19.14,
  25  * and 19.16.
  26  */
  27
  28 #include <sys/param.h>
  29 #include <sys/sysctl.h>
  30
  31 #include <net/route.h>
  32 #include <net/if_dl.h>
  33
  34 /* XXX what about Alpha? */
  35 #ifdef sgi
  36 #define ROUNDUP(a) ((a) > 0 ? \
  37                 (1 + (((a) - 1) | (sizeof(__uint64_t) - 1))) : \
  38                 sizeof(__uint64_t))
  39 #else
  40 #define ROUNDUP(a) ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) \
  41                     : sizeof(long))
  42 #endif
  43
  44 #define IFITER_MAGIC            ISC_MAGIC('I', 'F', 'I', 'S')
  45 #define VALID_IFITER(t)         ISC_MAGIC_VALID(t, IFITER_MAGIC)
  46
  47 struct isc_interfaceiter {
  48         unsigned int            magic;          /* Magic number. */
  49         isc_mem_t               *mctx;
  50         void                    *buf;           /* Buffer for sysctl data. */
  51         unsigned int            bufsize;        /* Bytes allocated. */
  52         unsigned int            bufused;        /* Bytes used. */
  53         unsigned int            pos;            /* Current offset in
  54                                                    sysctl data. */
  55         isc_interface_t         current;        /* Current interface data. */
  56         isc_result_t            result;         /* Last result code. */
  57 };
  58
  59 static int mib[6] = {
  60         CTL_NET,
  61         PF_ROUTE,
  62         0,
  63         0,                      /* Any address family. */
  64         NET_RT_IFLIST,
  65         0                       /* Flags. */
  66 };
  67
  68 isc_result_t
  69 isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
  70         isc_interfaceiter_t *iter;
  71         isc_result_t result;
  72         size_t bufsize;
  73         size_t bufused;
  74         char strbuf[ISC_STRERRORSIZE];
  75
  76         REQUIRE(iterp != NULL);
  77         REQUIRE(*iterp == NULL);
  78
  79         iter = isc_mem_get(mctx, sizeof(*iter));
  80         if (iter == NULL)
  81                 return (ISC_R_NOMEMORY);
  82
  83         iter->mctx = mctx;
  84         iter->buf = 0;
  85
  86         /*
  87          * Determine the amount of memory needed.
  88          */
  89         bufsize = 0;
  90         if (sysctl(mib, 6, NULL, &bufsize, NULL, (size_t) 0) < 0) {
  91                 isc__strerror(errno, strbuf, sizeof(strbuf));
  92                 UNEXPECTED_ERROR(__FILE__, __LINE__,
  93                                  isc_msgcat_get(isc_msgcat,
  94                                                 ISC_MSGSET_IFITERSYSCTL,
  95                                                 ISC_MSG_GETIFLISTSIZE,
  96                                                 "getting interface "
  97                                                 "list size: sysctl: %s"),
  98                                  strbuf);
  99                 result = ISC_R_UNEXPECTED;
 100                 goto failure;
 101         }
 102         iter->bufsize = bufsize;
 103
 104         iter->buf = isc_mem_get(iter->mctx, iter->bufsize);
 105         if (iter->buf == NULL) {
 106                 result = ISC_R_NOMEMORY;
 107                 goto failure;
 108         }
 109
 110         bufused = bufsize;
 111         if (sysctl(mib, 6, iter->buf, &bufused, NULL, (size_t) 0) < 0) {
 112                 isc__strerror(errno, strbuf, sizeof(strbuf));
 113                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 114                                  isc_msgcat_get(isc_msgcat,
 115                                                 ISC_MSGSET_IFITERSYSCTL,
 116                                                 ISC_MSG_GETIFLIST,
 117                                                 "getting interface list: "
 118                                                 "sysctl: %s"),
 119                                  strbuf);
 120                 result = ISC_R_UNEXPECTED;
 121                 goto failure;
 122         }
 123         iter->bufused = bufused;
 124         INSIST(iter->bufused <= iter->bufsize);
 125
 126         /*
 127          * A newly created iterator has an undefined position
 128          * until isc_interfaceiter_first() is called.
 129          */
 130         iter->pos = (unsigned int) -1;
 131         iter->result = ISC_R_FAILURE;
 132
 133         iter->magic = IFITER_MAGIC;
 134         *iterp = iter;
 135         return (ISC_R_SUCCESS);
 136
 137  failure:
 138         if (iter->buf != NULL)
 139                 isc_mem_put(mctx, iter->buf, iter->bufsize);
 140         isc_mem_put(mctx, iter, sizeof(*iter));
 141         return (result);
 142 }
 143
 144 /*
 145  * Get information about the current interface to iter->current.
 146  * If successful, return ISC_R_SUCCESS.
 147  * If the interface has an unsupported address family,
 148  * return ISC_R_IGNORE.  In case of other failure,
 149  * return ISC_R_UNEXPECTED.
 150  */
 151
 152 static isc_result_t
 153 internal_current(isc_interfaceiter_t *iter) {
 154         struct ifa_msghdr *ifam, *ifam_end;
 155
 156         REQUIRE(VALID_IFITER(iter));
 157         REQUIRE (iter->pos < (unsigned int) iter->bufused);
 158
 159         ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
 160         ifam_end = (struct ifa_msghdr *) ((char *) iter->buf + iter->bufused);
 161
 162         if (ifam->ifam_type == RTM_IFINFO) {
 163                 struct if_msghdr *ifm = (struct if_msghdr *) ifam;
 164                 struct sockaddr_dl *sdl = (struct sockaddr_dl *) (ifm + 1);
 165                 unsigned int namelen;
 166
 167                 memset(&iter->current, 0, sizeof(iter->current));
 168
 169                 namelen = sdl->sdl_nlen;
 170                 if (namelen > sizeof(iter->current.name) - 1)
 171                         namelen = sizeof(iter->current.name) - 1;
 172
 173                 memset(iter->current.name, 0, sizeof(iter->current.name));
 174                 memcpy(iter->current.name, sdl->sdl_data, namelen);
 175
 176                 iter->current.flags = 0;
 177
 178                 if ((ifam->ifam_flags & IFF_UP) != 0)
 179                         iter->current.flags |= INTERFACE_F_UP;
 180
 181                 if ((ifam->ifam_flags & IFF_POINTOPOINT) != 0)
 182                         iter->current.flags |= INTERFACE_F_POINTTOPOINT;
 183
 184                 if ((ifam->ifam_flags & IFF_LOOPBACK) != 0)
 185                         iter->current.flags |= INTERFACE_F_LOOPBACK;
 186
 187                 if ((ifam->ifam_flags & IFF_BROADCAST) != 0) {
 188                         iter->current.flags |= INTERFACE_F_BROADCAST;
 189                 }
 190 #ifdef IFF_MULTICAST
 191                 if ((ifam->ifam_flags & IFF_MULTICAST) != 0) {
 192                         iter->current.flags |= INTERFACE_F_MULTICAST;
 193                 }
 194 #endif
 195
 196                 /*
 197                  * This is not an interface address.
 198                  * Force another iteration.
 199                  */
 200                 return (ISC_R_IGNORE);
 201         } else if (ifam->ifam_type == RTM_NEWADDR) {
 202                 int i;
 203                 int family;
 204                 struct sockaddr *mask_sa = NULL;
 205                 struct sockaddr *addr_sa = NULL;
 206                 struct sockaddr *dst_sa = NULL;
 207
 208                 struct sockaddr *sa = (struct sockaddr *)(ifam + 1);
 209                 family = sa->sa_family;
 210
 211                 for (i = 0; i < RTAX_MAX; i++)
 212                 {
 213                         if ((ifam->ifam_addrs & (1 << i)) == 0)
 214                                 continue;
 215
 216                         INSIST(sa < (struct sockaddr *) ifam_end);
 217
 218                         switch (i) {
 219                         case RTAX_NETMASK: /* Netmask */
 220                                 mask_sa = sa;
 221                                 break;
 222                         case RTAX_IFA: /* Interface address */
 223                                 addr_sa = sa;
 224                                 break;
 225                         case RTAX_BRD: /* Broadcast or destination address */
 226                                 dst_sa = sa;
 227                                 break;
 228                         }
 229 #ifdef ISC_PLATFORM_HAVESALEN
 230                         sa = (struct sockaddr *)((char*)(sa)
 231                                          + ROUNDUP(sa->sa_len));
 232 #else
 233 #ifdef sgi
 234                         /*
 235                          * Do as the contributed SGI code does.
 236                          */
 237                         sa = (struct sockaddr *)((char*)(sa)
 238                                          + ROUNDUP(_FAKE_SA_LEN_DST(sa)));
 239 #else
 240                         /* XXX untested. */
 241                         sa = (struct sockaddr *)((char*)(sa)
 242                                          + ROUNDUP(sizeof(struct sockaddr)));
 243 #endif
 244 #endif
 245                 }
 246
 247                 if (addr_sa == NULL)
 248                         return (ISC_R_IGNORE);
 249
 250                 family = addr_sa->sa_family;
 251                 if (family != AF_INET && family != AF_INET6)
 252                         return (ISC_R_IGNORE);
 253
 254                 iter->current.af = family;
 255
 256                 get_addr(family, &iter->current.address, addr_sa,
 257                          iter->current.name);
 258
 259         /*
 260          * If the interface does not have a address ignore it.
 261          */
 262         switch (family) {
 263         case AF_INET:
 264                 if (iter->current.address.type.in.s_addr == htonl(INADDR_ANY))
 265                         return (ISC_R_IGNORE);
 266                 break;
 267         case AF_INET6:
 268                 if (memcmp(&iter->current.address.type.in6, &in6addr_any,
 269                            sizeof(in6addr_any)) == 0)
 270                         return (ISC_R_IGNORE);
 271                 break;
 272         }
 273
 274                 if (mask_sa != NULL)
 275                         get_addr(family, &iter->current.netmask, mask_sa,
 276                                  iter->current.name);
 277
 278                 if (dst_sa != NULL &&
 279                     (iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0)
 280                         get_addr(family, &iter->current.dstaddress, dst_sa,
 281                                  iter->current.name);
 282
 283                 if (dst_sa != NULL &&
 284                     (iter->current.flags & INTERFACE_F_BROADCAST) != 0)
 285                         get_addr(family, &iter->current.broadcast, dst_sa,
 286                                  iter->current.name);
 287
 288
 289                 return (ISC_R_SUCCESS);
 290         } else {
 291                 printf(isc_msgcat_get(isc_msgcat, ISC_MSGSET_IFITERSYSCTL,
 292                                       ISC_MSG_UNEXPECTEDTYPE,
 293                                       "warning: unexpected interface list "
 294                                       "message type\n"));
 295                 return (ISC_R_IGNORE);
 296         }
 297 }
 298
 299 /*
 300  * Step the iterator to the next interface.  Unlike
 301  * isc_interfaceiter_next(), this may leave the iterator
 302  * positioned on an interface that will ultimately
 303  * be ignored.  Return ISC_R_NOMORE if there are no more
 304  * interfaces, otherwise ISC_R_SUCCESS.
 305  */
 306 static isc_result_t
 307 internal_next(isc_interfaceiter_t *iter) {
 308         struct ifa_msghdr *ifam;
 309         REQUIRE (iter->pos < (unsigned int) iter->bufused);
 310
 311         ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos);
 312
 313         iter->pos += ifam->ifam_msglen;
 314
 315         if (iter->pos >= iter->bufused)
 316                 return (ISC_R_NOMORE);
 317
 318         return (ISC_R_SUCCESS);
 319 }
 320
 321 static void
 322 internal_destroy(isc_interfaceiter_t *iter) {
 323         UNUSED(iter); /* Unused. */
 324         /*
 325          * Do nothing.
 326          */
 327 }
 328
 329 static
 330 void internal_first(isc_interfaceiter_t *iter) {
 331         iter->pos = 0;
 332 }