lib/libc/net/getifaddrs.c

   1 /*      $FreeBSD: src/lib/libc/net/getifaddrs.c,v 1.6 2002/07/25 08:08:30 ume Exp $     */
   2 /*      $KAME: getifaddrs.c,v 1.9 2001/08/20 02:31:20 itojun Exp $      */
   3
   4 /*
   5  * Copyright (c) 1995, 1999
   6  *      Berkeley Software Design, Inc.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  *      BSDI getifaddrs.c,v 2.12 2000/02/23 14:51:59 dab Exp
  27  */
  28 /*
  29  * NOTE: SIOCGIFCONF case is not LP64 friendly.  it also does not perform
  30  * try-and-error for region size.
  31  */
  32 #include "namespace.h"
  33 #include <sys/types.h>
  34 #include <sys/ioctl.h>
  35 #include <sys/socket.h>
  36 #include <net/if.h>
  37 #ifdef  NET_RT_IFLIST
  38 #include <sys/param.h>
  39 #include <net/route.h>
  40 #include <sys/sysctl.h>
  41 #include <net/if_dl.h>
  42 #endif
  43
  44 #include <errno.h>
  45 #include <ifaddrs.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include "un-namespace.h"
  49
  50 #if !defined(AF_LINK)
  51 #define SA_LEN(sa)      sizeof(struct sockaddr)
  52 #endif
  53
  54 #if !defined(SA_LEN)
  55 #define SA_LEN(sa)      (sa)->sa_len
  56 #endif
  57
  58 #define SA_RLEN(sa)     RT_ROUNDUP((sa)->sa_len)
  59
  60 #ifndef ALIGNBYTES
  61 /*
  62  * On systems with a routing socket, ALIGNBYTES should match the value
  63  * that the kernel uses when building the messages.
  64  */
  65 #define ALIGNBYTES      XXX
  66 #endif
  67 #ifndef ALIGN
  68 #define ALIGN(p)        (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES)
  69 #endif
  70
  71 #if     _BSDI_VERSION >= 199701
  72 #define HAVE_IFM_DATA
  73 #endif
  74
  75 #if     _BSDI_VERSION >= 199802
  76 /* ifam_data is very specific to recent versions of bsdi */
  77 #define HAVE_IFAM_DATA
  78 #endif
  79
  80 #if defined(__NetBSD__) || defined(__OpenBSD__) || \
  81     defined(__FreeBSD__) || defined(__DragonFly__)
  82 #define HAVE_IFM_DATA
  83 #endif
  84
  85 #define MAX_SYSCTL_TRY 5
  86
  87 int
  88 getifaddrs(struct ifaddrs **pif)
  89 {
  90         int icnt = 1;
  91         int dcnt = 0;
  92         int ncnt = 0;
  93 #ifdef  NET_RT_IFLIST
  94         int ntry = 0;
  95         int mib[6];
  96         size_t needed;
  97         char *buf;
  98         char *next;
  99         struct ifaddrs *cif = NULL;
 100         char *p, *p0;
 101         struct rt_msghdr *rtm;
 102         struct if_msghdr *ifm;
 103         struct ifa_msghdr *ifam;
 104         struct sockaddr_dl *dl;
 105         struct sockaddr *sa;
 106         struct ifaddrs *ifa, *ift;
 107         u_short idx = 0;
 108 #else   /* NET_RT_IFLIST */
 109         char buf[1024];
 110         int sock;
 111         struct ifconf ifc;
 112         struct ifreq *ifr;
 113         struct ifreq *lifr;
 114 #endif  /* NET_RT_IFLIST */
 115         int i;
 116         size_t len, alen;
 117         char *data;
 118         char *names;
 119
 120 #ifdef  NET_RT_IFLIST
 121         mib[0] = CTL_NET;
 122         mib[1] = PF_ROUTE;
 123         mib[2] = 0;             /* protocol */
 124         mib[3] = 0;             /* wildcard address family */
 125         mib[4] = NET_RT_IFLIST;
 126         mib[5] = 0;             /* no flags */
 127         do {
 128                 /*
 129                  * We'll try to get addresses several times in case that
 130                  * the number of addresses is unexpectedly increased during
 131                  * the two sysctl calls.  This should rarely happen, but we'll
 132                  * try to do our best for applications that assume success of
 133                  * this library (which should usually be the case).
 134                  * Portability note: since FreeBSD does not add margin of
 135                  * memory at the first sysctl, the possibility of failure on
 136                  * the second sysctl call is a bit higher.
 137                  */
 138
 139                 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
 140                         return (-1);
 141                 if ((buf = malloc(needed)) == NULL)
 142                         return (-1);
 143                 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
 144                         if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) {
 145                                 free(buf);
 146                                 return (-1);
 147                         }
 148                         free(buf);
 149                         buf = NULL;
 150                 }
 151         } while (buf == NULL);
 152
 153         for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
 154                 rtm = (struct rt_msghdr *)(void *)next;
 155                 if (rtm->rtm_version != RTM_VERSION)
 156                         continue;
 157                 switch (rtm->rtm_type) {
 158                 case RTM_IFINFO:
 159                         ifm = (struct if_msghdr *)(void *)rtm;
 160                         if (ifm->ifm_addrs & RTA_IFP) {
 161                                 idx = ifm->ifm_index;
 162                                 ++icnt;
 163                                 dl = (struct sockaddr_dl *)(void *)(ifm + 1);
 164                                 dcnt += SA_RLEN((struct sockaddr *)(void*)dl) +
 165                                     ALIGNBYTES;
 166 #ifdef  HAVE_IFM_DATA
 167                                 dcnt += sizeof(ifm->ifm_data);
 168 #endif  /* HAVE_IFM_DATA */
 169                                 ncnt += dl->sdl_nlen + 1;
 170                         } else
 171                                 idx = 0;
 172                         break;
 173
 174                 case RTM_NEWADDR:
 175                         ifam = (struct ifa_msghdr *)(void *)rtm;
 176                         if (idx && ifam->ifam_index != idx)
 177                                 abort();        /* this cannot happen */
 178
 179 #define RTA_MASKS       (RTA_NETMASK | RTA_IFA | RTA_BRD)
 180                         if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
 181                                 break;
 182                         p = (char *)(void *)(ifam + 1);
 183                         ++icnt;
 184 #ifdef  HAVE_IFAM_DATA
 185                         dcnt += sizeof(ifam->ifam_data) + ALIGNBYTES;
 186 #endif  /* HAVE_IFAM_DATA */
 187                         /* Scan to look for length of address */
 188                         alen = 0;
 189                         for (p0 = p, i = 0; i < RTAX_MAX; i++) {
 190                                 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
 191                                     == 0)
 192                                         continue;
 193                                 sa = (struct sockaddr *)(void *)p;
 194                                 len = SA_RLEN(sa);
 195                                 if (i == RTAX_IFA) {
 196                                         alen = len;
 197                                         break;
 198                                 }
 199                                 p += len;
 200                         }
 201                         for (p = p0, i = 0; i < RTAX_MAX; i++) {
 202                                 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
 203                                     == 0)
 204                                         continue;
 205                                 sa = (struct sockaddr *)(void *)p;
 206                                 len = SA_RLEN(sa);
 207                                 if (i == RTAX_NETMASK && SA_LEN(sa) == 0)
 208                                         dcnt += alen;
 209                                 else
 210                                         dcnt += len;
 211                                 p += len;
 212                         }
 213                         break;
 214                 }
 215         }
 216 #else   /* NET_RT_IFLIST */
 217         ifc.ifc_buf = buf;
 218         ifc.ifc_len = sizeof(buf);
 219
 220         if ((sock = _socket(AF_INET, SOCK_STREAM, 0)) < 0)
 221                 return (-1);
 222         i =  _ioctl(sock, SIOCGIFCONF, (char *)&ifc);
 223         _close(sock);
 224         if (i < 0)
 225                 return (-1);
 226
 227         ifr = ifc.ifc_req;
 228         lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len];
 229
 230         while (ifr < lifr) {
 231                 struct sockaddr *sa;
 232
 233                 sa = &ifr->ifr_addr;
 234                 ++icnt;
 235                 dcnt += SA_RLEN(sa);
 236                 ncnt += sizeof(ifr->ifr_name) + 1;
 237
 238                 if (SA_LEN(sa) < sizeof(*sa))
 239                         ifr = (struct ifreq *)(((char *)sa) + sizeof(*sa));
 240                 else
 241                         ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa));
 242         }
 243 #endif  /* NET_RT_IFLIST */
 244
 245         if (icnt + dcnt + ncnt == 1) {
 246                 *pif = NULL;
 247                 free(buf);
 248                 return (0);
 249         }
 250         data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt);
 251         if (data == NULL) {
 252                 free(buf);
 253                 return(-1);
 254         }
 255
 256         ifa = (struct ifaddrs *)(void *)data;
 257         data += sizeof(struct ifaddrs) * icnt;
 258         names = data + dcnt;
 259
 260         memset(ifa, 0, sizeof(struct ifaddrs) * icnt);
 261         ift = ifa;
 262
 263 #ifdef  NET_RT_IFLIST
 264         idx = 0;
 265         for (next = buf; next < buf + needed; next += rtm->rtm_msglen) {
 266                 rtm = (struct rt_msghdr *)(void *)next;
 267                 if (rtm->rtm_version != RTM_VERSION)
 268                         continue;
 269                 switch (rtm->rtm_type) {
 270                 case RTM_IFINFO:
 271                         ifm = (struct if_msghdr *)(void *)rtm;
 272                         if (ifm->ifm_addrs & RTA_IFP) {
 273                                 idx = ifm->ifm_index;
 274                                 dl = (struct sockaddr_dl *)(void *)(ifm + 1);
 275
 276                                 cif = ift;
 277                                 ift->ifa_name = names;
 278                                 ift->ifa_flags = (int)ifm->ifm_flags;
 279                                 memcpy(names, dl->sdl_data,
 280                                     (size_t)dl->sdl_nlen);
 281                                 names[dl->sdl_nlen] = 0;
 282                                 names += dl->sdl_nlen + 1;
 283
 284                                 ift->ifa_addr = (struct sockaddr *)(void *)data;
 285                                 memcpy(data, dl,
 286                                     (size_t)SA_LEN((struct sockaddr *)
 287                                     (void *)dl));
 288                                 data += SA_RLEN((struct sockaddr *)(void *)dl);
 289
 290 #ifdef  HAVE_IFM_DATA
 291                                 /* ifm_data needs to be aligned */
 292                                 ift->ifa_data = data = (void *)ALIGN(data);
 293                                 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data));
 294                                 data += sizeof(ifm->ifm_data);
 295 #else   /* HAVE_IFM_DATA */
 296                                 ift->ifa_data = NULL;
 297 #endif  /* HAVE_IFM_DATA */
 298
 299                                 ift = (ift->ifa_next = ift + 1);
 300                         } else
 301                                 idx = 0;
 302                         break;
 303
 304                 case RTM_NEWADDR:
 305                         ifam = (struct ifa_msghdr *)(void *)rtm;
 306                         if (idx && ifam->ifam_index != idx)
 307                                 abort();        /* this cannot happen */
 308
 309                         if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0)
 310                                 break;
 311                         ift->ifa_name = cif->ifa_name;
 312                         ift->ifa_flags = cif->ifa_flags;
 313                         ift->ifa_data = NULL;
 314                         p = (char *)(void *)(ifam + 1);
 315                         /* Scan to look for length of address */
 316                         alen = 0;
 317                         for (p0 = p, i = 0; i < RTAX_MAX; i++) {
 318                                 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
 319                                     == 0)
 320                                         continue;
 321                                 sa = (struct sockaddr *)(void *)p;
 322                                 len = SA_RLEN(sa);
 323                                 if (i == RTAX_IFA) {
 324                                         alen = len;
 325                                         break;
 326                                 }
 327                                 p += len;
 328                         }
 329                         for (p = p0, i = 0; i < RTAX_MAX; i++) {
 330                                 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i))
 331                                     == 0)
 332                                         continue;
 333                                 sa = (struct sockaddr *)(void *)p;
 334                                 len = SA_RLEN(sa);
 335                                 switch (i) {
 336                                 case RTAX_IFA:
 337                                         ift->ifa_addr =
 338                                             (struct sockaddr *)(void *)data;
 339                                         memcpy(data, p, len);
 340                                         data += len;
 341                                         break;
 342
 343                                 case RTAX_NETMASK:
 344                                         ift->ifa_netmask =
 345                                             (struct sockaddr *)(void *)data;
 346                                         if (SA_LEN(sa) == 0) {
 347                                                 memset(data, 0, alen);
 348                                                 data += alen;
 349                                                 break;
 350                                         }
 351                                         memcpy(data, p, len);
 352                                         data += len;
 353                                         break;
 354
 355                                 case RTAX_BRD:
 356                                         ift->ifa_broadaddr =
 357                                             (struct sockaddr *)(void *)data;
 358                                         memcpy(data, p, len);
 359                                         data += len;
 360                                         break;
 361                                 }
 362                                 p += len;
 363                         }
 364
 365 #ifdef  HAVE_IFAM_DATA
 366                         /* ifam_data needs to be aligned */
 367                         ift->ifa_data = data = (void *)ALIGN(data);
 368                         memcpy(data, &ifam->ifam_data, sizeof(ifam->ifam_data));
 369                         data += sizeof(ifam->ifam_data);
 370 #endif  /* HAVE_IFAM_DATA */
 371
 372                         ift = (ift->ifa_next = ift + 1);
 373                         break;
 374                 }
 375         }
 376
 377         free(buf);
 378 #else   /* NET_RT_IFLIST */
 379         ifr = ifc.ifc_req;
 380         lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len];
 381
 382         while (ifr < lifr) {
 383                 struct sockaddr *sa;
 384
 385                 ift->ifa_name = names;
 386                 names[sizeof(ifr->ifr_name)] = 0;
 387                 strncpy(names, ifr->ifr_name, sizeof(ifr->ifr_name));
 388                 while (*names++)
 389                         ;
 390
 391                 ift->ifa_addr = (struct sockaddr *)data;
 392                 sa = &ifr->ifr_addr;
 393                 memcpy(data, sa, SA_LEN(sa));
 394                 data += SA_RLEN(sa);
 395
 396                 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa));
 397                 ift = (ift->ifa_next = ift + 1);
 398         }
 399 #endif  /* NET_RT_IFLIST */
 400         if (--ift >= ifa) {
 401                 ift->ifa_next = NULL;
 402                 *pif = ifa;
 403         } else {
 404                 *pif = NULL;
 405                 free(ifa);
 406         }
 407         return (0);
 408 }
 409
 410 void
 411 freeifaddrs(struct ifaddrs *ifp)
 412 {
 413
 414         free(ifp);
 415 }