usr.sbin/rpcbind/check_bound.c

   1 /*
   2  * Copyright (c) 2009, Sun Microsystems, Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  * - Redistributions of source code must retain the above copyright notice,
   8  *   this list of conditions and the following disclaimer.
   9  * - Redistributions in binary form must reproduce the above copyright notice,
  10  *   this list of conditions and the following disclaimer in the documentation
  11  *   and/or other materials provided with the distribution.
  12  * - Neither the name of Sun Microsystems, Inc. nor the names of its
  13  *   contributors may be used to endorse or promote products derived
  14  *   from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  26  * POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * @(#)check_bound.c    1.15    93/07/05 SMI; 1.11 89/04/21 Copyr 1989 Sun Micro
  29  * $NetBSD: check_bound.c,v 1.2 2000/06/22 08:09:26 fvdl Exp $
  30  * $FreeBSD: src/usr.sbin/rpcbind/check_bound.c,v 1.5 2007/11/07 10:53:39 kevlo Exp $
  31  */
  32 /*
  33  * Copyright (c) 1986 - 1991 by Sun Microsystems, Inc.
  34  */
  35
  36 /*
  37  * check_bound.c
  38  * Checks to see whether the program is still bound to the
  39  * claimed address and returns the univeral merged address
  40  *
  41  */
  42
  43 #include <sys/types.h>
  44 #include <sys/socket.h>
  45 #include <rpc/rpc.h>
  46 #include <stdio.h>
  47 #include <netconfig.h>
  48 #include <syslog.h>
  49 #include <string.h>
  50 #include <unistd.h>
  51 #include <stdlib.h>
  52
  53 #include "rpcbind.h"
  54
  55 struct fdlist {
  56         int fd;
  57         struct netconfig *nconf;
  58         struct fdlist *next;
  59         int check_binding;
  60 };
  61
  62 static struct fdlist *fdhead;   /* Link list of the check fd's */
  63 static struct fdlist *fdtail;
  64 static char *nullstring = "";
  65
  66 static bool_t   check_bound(struct fdlist *, char *uaddr);
  67
  68 /*
  69  * Returns 1 if the given address is bound for the given addr & transport
  70  * For all error cases, we assume that the address is bound
  71  * Returns 0 for success.
  72  */
  73 static bool_t
  74 check_bound(struct fdlist *fdl, char *uaddr)
  75 {
  76         int fd;
  77         struct netbuf *na;
  78         int ans;
  79
  80         if (fdl->check_binding == FALSE)
  81                 return (TRUE);
  82
  83         na = uaddr2taddr(fdl->nconf, uaddr);
  84         if (!na)
  85                 return (TRUE); /* punt, should never happen */
  86
  87         fd = __rpc_nconf2fd(fdl->nconf);
  88         if (fd < 0) {
  89                 free(na->buf);
  90                 free(na);
  91                 return (TRUE);
  92         }
  93
  94         ans = bind(fd, (struct sockaddr *)na->buf, na->len);
  95
  96         close(fd);
  97         free(na->buf);
  98         free(na);
  99
 100         return (ans == 0 ? FALSE : TRUE);
 101 }
 102
 103 int
 104 add_bndlist(struct netconfig *nconf, struct netbuf *baddr __unused)
 105 {
 106         struct fdlist *fdl;
 107         struct netconfig *newnconf;
 108
 109         newnconf = getnetconfigent(nconf->nc_netid);
 110         if (newnconf == NULL)
 111                 return (-1);
 112         fdl = malloc(sizeof (struct fdlist));
 113         if (fdl == NULL) {
 114                 freenetconfigent(newnconf);
 115                 syslog(LOG_ERR, "no memory!");
 116                 return (-1);
 117         }
 118         fdl->nconf = newnconf;
 119         fdl->next = NULL;
 120         if (fdhead == NULL) {
 121                 fdhead = fdl;
 122                 fdtail = fdl;
 123         } else {
 124                 fdtail->next = fdl;
 125                 fdtail = fdl;
 126         }
 127         /* XXX no bound checking for now */
 128         fdl->check_binding = FALSE;
 129
 130         return 0;
 131 }
 132
 133 bool_t
 134 is_bound(char *netid, char *uaddr)
 135 {
 136         struct fdlist *fdl;
 137
 138         for (fdl = fdhead; fdl; fdl = fdl->next)
 139                 if (strcmp(fdl->nconf->nc_netid, netid) == 0)
 140                         break;
 141         if (fdl == NULL)
 142                 return (TRUE);
 143         return (check_bound(fdl, uaddr));
 144 }
 145
 146 /*
 147  * Returns NULL if there was some system error.
 148  * Returns "" if the address was not bound, i.e the server crashed.
 149  * Returns the merged address otherwise.
 150  */
 151 char *
 152 mergeaddr(SVCXPRT *xprt, char *netid, char *uaddr, char *saddr)
 153 {
 154         struct fdlist *fdl;
 155         char *c_uaddr, *s_uaddr, *m_uaddr, *allocated_uaddr = NULL;
 156
 157         for (fdl = fdhead; fdl; fdl = fdl->next)
 158                 if (strcmp(fdl->nconf->nc_netid, netid) == 0)
 159                         break;
 160         if (fdl == NULL)
 161                 return (NULL);
 162         if (check_bound(fdl, uaddr) == FALSE)
 163                 /* that server died */
 164                 return (nullstring);
 165         /*
 166          * If saddr is not NULL, the remote client may have included the
 167          * address by which it contacted us.  Use that for the "client" uaddr,
 168          * otherwise use the info from the SVCXPRT.
 169          */
 170         if (saddr != NULL) {
 171                 c_uaddr = saddr;
 172         } else {
 173                 c_uaddr = taddr2uaddr(fdl->nconf, svc_getrpccaller(xprt));
 174                 if (c_uaddr == NULL) {
 175                         syslog(LOG_ERR, "taddr2uaddr failed for %s",
 176                                 fdl->nconf->nc_netid);
 177                         return (NULL);
 178                 }
 179                 allocated_uaddr = c_uaddr;
 180         }
 181
 182 #ifdef ND_DEBUG
 183         if (debugging) {
 184                 if (saddr == NULL) {
 185                         fprintf(stderr, "mergeaddr: client uaddr = %s\n",
 186                             c_uaddr);
 187                 } else {
 188                         fprintf(stderr, "mergeaddr: contact uaddr = %s\n",
 189                             c_uaddr);
 190                 }
 191         }
 192 #endif
 193         s_uaddr = uaddr;
 194         /*
 195          * This is all we should need for IP 4 and 6
 196          */
 197         m_uaddr = addrmerge(svc_getrpccaller(xprt), s_uaddr, c_uaddr, netid);
 198 #ifdef ND_DEBUG
 199         if (debugging)
 200                 fprintf(stderr, "mergeaddr: uaddr = %s, merged uaddr = %s\n",
 201                                 uaddr, m_uaddr);
 202 #endif
 203         if (allocated_uaddr != NULL)
 204                 free(allocated_uaddr);
 205         return (m_uaddr);
 206 }
 207
 208 /*
 209  * Returns a netconf structure from its internal list.  This
 210  * structure should not be freed.
 211  */
 212 struct netconfig *
 213 rpcbind_get_conf(char *netid)
 214 {
 215         struct fdlist *fdl;
 216
 217         for (fdl = fdhead; fdl; fdl = fdl->next)
 218                 if (strcmp(fdl->nconf->nc_netid, netid) == 0)
 219                         break;
 220         if (fdl == NULL)
 221                 return (NULL);
 222         return (fdl->nconf);
 223 }