usr/src/lib/libinetutil/common/ifaddrlist.c

   1 /*
   2  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
   3  * Use is subject to license terms.
   4  */
   5
   6 /*
   7  * Copyright (c) 1997
   8  *      The Regents of the University of California.  All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the Computer Systems
  21  *      Engineering Group at Lawrence Berkeley Laboratory.
  22  * 4. Neither the name of the University nor of the Laboratory may be used
  23  *    to endorse or promote products derived from this software without
  24  *    specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  *
  38  * @(#) $Header: ifaddrlist.c,v 1.2 97/04/22 13:31:05 leres Exp $ (LBL)
  39  */
  40
  41 #include <errno.h>
  42 #include <libinetutil.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46 #include <unistd.h>
  47 #include <sys/socket.h>
  48 #include <sys/sockio.h>
  49
  50 /*
  51  * See <libinetutil.h> for a description of the programming interface.
  52  */
  53 int
  54 ifaddrlist(struct ifaddrlist **ipaddrp, int family, uint_t flags, char *errbuf)
  55 {
  56         struct ifaddrlist       *ifaddrlist = NULL, *al = NULL;
  57         struct sockaddr_in      *sin;
  58         struct sockaddr_in6     *sin6;
  59         struct lifconf          lifc;
  60         struct lifnum           lifn;
  61         struct lifreq           *lifrp;
  62         int                     i, count, nlifr;
  63         int                     fd;
  64         const char              *opstr;
  65
  66         (void) memset(&lifc, 0, sizeof (lifc));
  67         if (family != AF_INET && family != AF_INET6) {
  68                 (void) strlcpy(errbuf, "invalid address family", ERRBUFSIZE);
  69                 return (-1);
  70         }
  71
  72         if ((fd = socket(family, SOCK_DGRAM, 0)) == -1) {
  73                 opstr = "socket";
  74                 goto fail;
  75         }
  76
  77         /*
  78          * Get the number of network interfaces of type `family'.
  79          */
  80         lifn.lifn_family = family;
  81         lifn.lifn_flags = flags;
  82 again:
  83         if (ioctl(fd, SIOCGLIFNUM, &lifn) == -1) {
  84                 opstr = "SIOCGLIFNUM";
  85                 goto fail;
  86         }
  87
  88         /*
  89          * Pad the interface count to detect when additional interfaces have
  90          * been configured between SIOCGLIFNUM and SIOCGLIFCONF.
  91          */
  92         lifn.lifn_count += 4;
  93
  94         lifc.lifc_flags = flags;
  95         lifc.lifc_family = family;
  96         lifc.lifc_len = lifn.lifn_count * sizeof (struct lifreq);
  97         if ((lifc.lifc_buf = realloc(lifc.lifc_buf, lifc.lifc_len)) == NULL) {
  98                 opstr = "realloc";
  99                 goto fail;
 100         }
 101
 102         if (ioctl(fd, SIOCGLIFCONF, &lifc) == -1) {
 103                 opstr = "SIOCGLIFCONF";
 104                 goto fail;
 105         }
 106
 107         /*
 108          * If every lifr_req slot is taken, then additional interfaces must
 109          * have been plumbed between the SIOCGLIFNUM and the SIOCGLIFCONF.
 110          * Recalculate to make sure we didn't miss any interfaces.
 111          */
 112         nlifr = lifc.lifc_len / sizeof (struct lifreq);
 113         if (nlifr >= lifn.lifn_count)
 114                 goto again;
 115
 116         /*
 117          * Allocate the address list to return.
 118          */
 119         if ((ifaddrlist = calloc(nlifr, sizeof (struct ifaddrlist))) == NULL) {
 120                 opstr = "calloc";
 121                 goto fail;
 122         }
 123
 124         /*
 125          * Populate the address list by querying each underlying interface.
 126          * If a query ioctl returns ENXIO, then the interface must have been
 127          * removed after the SIOCGLIFCONF completed -- so we just ignore it.
 128          */
 129         al = ifaddrlist;
 130         count = 0;
 131         for (lifrp = lifc.lifc_req, i = 0; i < nlifr; i++, lifrp++) {
 132                 (void) strlcpy(al->device, lifrp->lifr_name, LIFNAMSIZ);
 133
 134                 if (ioctl(fd, SIOCGLIFFLAGS, lifrp) == -1) {
 135                         if (errno == ENXIO)
 136                                 continue;
 137                         opstr = "SIOCGLIFFLAGS";
 138                         goto fail;
 139                 }
 140                 al->flags = lifrp->lifr_flags;
 141
 142                 if (ioctl(fd, SIOCGLIFINDEX, lifrp) == -1) {
 143                         if (errno == ENXIO)
 144                                 continue;
 145                         opstr = "SIOCGLIFINDEX";
 146                         goto fail;
 147                 }
 148                 al->index = lifrp->lifr_index;
 149
 150                 if (ioctl(fd, SIOCGLIFADDR, lifrp) == -1) {
 151                         if (errno == ENXIO)
 152                                 continue;
 153                         opstr = "SIOCGLIFADDR";
 154                         goto fail;
 155                 }
 156
 157                 if (family == AF_INET) {
 158                         sin = (struct sockaddr_in *)&lifrp->lifr_addr;
 159                         al->addr.addr = sin->sin_addr;
 160                 } else {
 161                         sin6 = (struct sockaddr_in6 *)&lifrp->lifr_addr;
 162                         al->addr.addr6 = sin6->sin6_addr;
 163                 }
 164                 al++;
 165                 count++;
 166         }
 167
 168         (void) close(fd);
 169         free(lifc.lifc_buf);
 170         if (count == 0) {
 171                 free(ifaddrlist);
 172                 *ipaddrp = NULL;
 173                 return (0);
 174         }
 175
 176         *ipaddrp = ifaddrlist;
 177         return (count);
 178 fail:
 179         if (al == NULL) {
 180                 (void) snprintf(errbuf, ERRBUFSIZE, "%s: %s", opstr,
 181                     strerror(errno));
 182         } else {
 183                 (void) snprintf(errbuf, ERRBUFSIZE, "%s: %s: %s", opstr,
 184                     al->device, strerror(errno));
 185         }
 186         free(lifc.lifc_buf);
 187         free(ifaddrlist);
 188         (void) close(fd);
 189         return (-1);
 190 }