lib/krb5/get_addrs.c

   1 /*
   2  * Copyright (c) 1997 - 2002 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "krb5_locl.h"
  35
  36 #ifdef __osf__
  37 /* hate */
  38 struct rtentry;
  39 struct mbuf;
  40 #endif
  41 #ifdef HAVE_NET_IF_H
  42 #include <net/if.h>
  43 #endif
  44 #include <ifaddrs.h>
  45
  46 static krb5_error_code
  47 gethostname_fallback (krb5_context context, krb5_addresses *res)
  48 {
  49     krb5_error_code ret;
  50     char hostname[MAXHOSTNAMELEN];
  51     struct hostent *hostent;
  52
  53     if (gethostname (hostname, sizeof(hostname))) {
  54         ret = errno;
  55         krb5_set_error_message(context, ret, "gethostname: %s", strerror(ret));
  56         return ret;
  57     }
  58     hostent = roken_gethostbyname (hostname);
  59     if (hostent == NULL) {
  60         ret = errno;
  61         krb5_set_error_message (context, ret, "gethostbyname %s: %s",
  62                                 hostname, strerror(ret));
  63         return ret;
  64     }
  65     res->len = 1;
  66     res->val = malloc (sizeof(*res->val));
  67     if (res->val == NULL) {
  68         krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
  69         return ENOMEM;
  70     }
  71     res->val[0].addr_type = hostent->h_addrtype;
  72     res->val[0].address.data = NULL;
  73     res->val[0].address.length = 0;
  74     ret = krb5_data_copy (&res->val[0].address,
  75                           hostent->h_addr,
  76                           hostent->h_length);
  77     if (ret) {
  78         free (res->val);
  79         return ret;
  80     }
  81     return 0;
  82 }
  83
  84 enum {
  85     LOOP            = 1,        /* do include loopback interfaces */
  86     LOOP_IF_NONE    = 2,        /* include loopback if no other if's */
  87     EXTRA_ADDRESSES = 4,        /* include extra addresses */
  88     SCAN_INTERFACES = 8         /* scan interfaces for addresses */
  89 };
  90
  91 /*
  92  * Try to figure out the addresses of all configured interfaces with a
  93  * lot of magic ioctls.
  94  */
  95
  96 static krb5_error_code
  97 find_all_addresses (krb5_context context, krb5_addresses *res, int flags)
  98 {
  99     struct sockaddr sa_zero;
 100     struct ifaddrs *ifa0, *ifa;
 101     krb5_error_code ret = ENXIO;
 102     unsigned int num, idx;
 103     krb5_addresses ignore_addresses;
 104
 105     if (getifaddrs(&ifa0) == -1) {
 106         ret = errno;
 107         krb5_set_error_message(context, ret, "getifaddrs: %s", strerror(ret));
 108         return (ret);
 109     }
 110
 111     memset(&sa_zero, 0, sizeof(sa_zero));
 112
 113     /* First, count all the ifaddrs. */
 114     for (ifa = ifa0, num = 0; ifa != NULL; ifa = ifa->ifa_next, num++)
 115         /* nothing */;
 116
 117     if (num == 0) {
 118         freeifaddrs(ifa0);
 119         krb5_set_error_message(context, ENXIO, N_("no addresses found", ""));
 120         return (ENXIO);
 121     }
 122
 123     if (flags & EXTRA_ADDRESSES) {
 124         /* we'll remove the addresses we don't care about */
 125         ret = krb5_get_ignore_addresses(context, &ignore_addresses);
 126         if(ret)
 127             return ret;
 128     }
 129
 130     /* Allocate storage for them. */
 131     res->val = calloc(num, sizeof(*res->val));
 132     if (res->val == NULL) {
 133         krb5_free_addresses(context, &ignore_addresses);
 134         freeifaddrs(ifa0);
 135         krb5_set_error_message(context, ENOMEM, N_("malloc: out of memory", ""));
 136         return ENOMEM;
 137     }
 138
 139     /* Now traverse the list. */
 140     for (ifa = ifa0, idx = 0; ifa != NULL; ifa = ifa->ifa_next) {
 141         if ((ifa->ifa_flags & IFF_UP) == 0)
 142             continue;
 143         if (ifa->ifa_addr == NULL)
 144             continue;
 145         if (memcmp(ifa->ifa_addr, &sa_zero, sizeof(sa_zero)) == 0)
 146             continue;
 147         if (krb5_sockaddr_uninteresting(ifa->ifa_addr))
 148             continue;
 149         if ((ifa->ifa_flags & IFF_LOOPBACK) != 0) {
 150             /* We'll deal with the LOOP_IF_NONE case later. */
 151             if ((flags & LOOP) == 0)
 152                 continue;
 153         }
 154
 155         ret = krb5_sockaddr2address(context, ifa->ifa_addr, &res->val[idx]);
 156         if (ret) {
 157             /*
 158              * The most likely error here is going to be "Program
 159              * lacks support for address type".  This is no big
 160              * deal -- just continue, and we'll listen on the
 161              * addresses who's type we *do* support.
 162              */
 163             continue;
 164         }
 165         /* possibly skip this address? */
 166         if((flags & EXTRA_ADDRESSES) &&
 167            krb5_address_search(context, &res->val[idx], &ignore_addresses)) {
 168             krb5_free_address(context, &res->val[idx]);
 169             flags &= ~LOOP_IF_NONE; /* we actually found an address,
 170                                        so don't add any loop-back
 171                                        addresses */
 172             continue;
 173         }
 174
 175         idx++;
 176     }
 177
 178     /*
 179      * If no addresses were found, and LOOP_IF_NONE is set, then find
 180      * the loopback addresses and add them to our list.
 181      */
 182     if ((flags & LOOP_IF_NONE) != 0 && idx == 0) {
 183         for (ifa = ifa0; ifa != NULL; ifa = ifa->ifa_next) {
 184             if ((ifa->ifa_flags & IFF_UP) == 0)
 185                 continue;
 186             if (ifa->ifa_addr == NULL)
 187                 continue;
 188             if (memcmp(ifa->ifa_addr, &sa_zero, sizeof(sa_zero)) == 0)
 189                 continue;
 190             if (krb5_sockaddr_uninteresting(ifa->ifa_addr))
 191                 continue;
 192
 193             if ((ifa->ifa_flags & IFF_LOOPBACK) != 0) {
 194                 ret = krb5_sockaddr2address(context,
 195                                             ifa->ifa_addr, &res->val[idx]);
 196                 if (ret) {
 197                     /*
 198                      * See comment above.
 199                      */
 200                     continue;
 201                 }
 202                 if((flags & EXTRA_ADDRESSES) &&
 203                    krb5_address_search(context, &res->val[idx],
 204                                        &ignore_addresses)) {
 205                     krb5_free_address(context, &res->val[idx]);
 206                     continue;
 207                 }
 208                 idx++;
 209             }
 210         }
 211     }
 212
 213     if (flags & EXTRA_ADDRESSES)
 214         krb5_free_addresses(context, &ignore_addresses);
 215     freeifaddrs(ifa0);
 216     if (ret) {
 217         free(res->val);
 218         res->val = NULL;
 219     } else
 220         res->len = idx;        /* Now a count. */
 221     return (ret);
 222 }
 223
 224 static krb5_error_code
 225 get_addrs_int (krb5_context context, krb5_addresses *res, int flags)
 226 {
 227     krb5_error_code ret = -1;
 228
 229     res->len = 0;
 230     res->val = NULL;
 231
 232     if (flags & SCAN_INTERFACES) {
 233         ret = find_all_addresses (context, res, flags);
 234         if(ret || res->len == 0)
 235             ret = gethostname_fallback (context, res);
 236     } else {
 237         ret = 0;
 238     }
 239
 240     if(ret == 0 && (flags & EXTRA_ADDRESSES)) {
 241         krb5_addresses a;
 242         /* append user specified addresses */
 243         ret = krb5_get_extra_addresses(context, &a);
 244         if(ret) {
 245             krb5_free_addresses(context, res);
 246             return ret;
 247         }
 248         ret = krb5_append_addresses(context, res, &a);
 249         if(ret) {
 250             krb5_free_addresses(context, res);
 251             return ret;
 252         }
 253         krb5_free_addresses(context, &a);
 254     }
 255     if(res->len == 0) {
 256         free(res->val);
 257         res->val = NULL;
 258     }
 259     return ret;
 260 }
 261
 262 /*
 263  * Try to get all addresses, but return the one corresponding to
 264  * `hostname' if we fail.
 265  *
 266  * Only include loopback address if there are no other.
 267  */
 268
 269 krb5_error_code KRB5_LIB_FUNCTION
 270 krb5_get_all_client_addrs (krb5_context context, krb5_addresses *res)
 271 {
 272     int flags = LOOP_IF_NONE | EXTRA_ADDRESSES;
 273
 274     if (context->scan_interfaces)
 275         flags |= SCAN_INTERFACES;
 276
 277     return get_addrs_int (context, res, flags);
 278 }
 279
 280 /*
 281  * Try to get all local addresses that a server should listen to.
 282  * If that fails, we return the address corresponding to `hostname'.
 283  */
 284
 285 krb5_error_code KRB5_LIB_FUNCTION
 286 krb5_get_all_server_addrs (krb5_context context, krb5_addresses *res)
 287 {
 288     return get_addrs_int (context, res, LOOP | SCAN_INTERFACES);
 289 }