usr.sbin/rpcbind/check_bound.c

   1 /*      $NetBSD: check_bound.c,v 1.4 2007/05/13 20:03:46 christos Exp $ */
   2
   3 /*
   4  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   5  * unrestricted use provided that this legend is included on all tape
   6  * media and as a part of the software program in whole or part.  Users
   7  * may copy or modify Sun RPC without charge, but are not authorized
   8  * to license or distribute it to anyone else except as part of a product or
   9  * program developed by the user.
  10  *
  11  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  12  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  13  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  14  *
  15  * Sun RPC is provided with no support and without any obligation on the
  16  * part of Sun Microsystems, Inc. to assist in its use, correction,
  17  * modification or enhancement.
  18  *
  19  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  20  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  21  * OR ANY PART THEREOF.
  22  *
  23  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  24  * or profits or other special, indirect and consequential damages, even if
  25  * Sun has been advised of the possibility of such damages.
  26  *
  27  * Sun Microsystems, Inc.
  28  * 2550 Garcia Avenue
  29  * Mountain View, California  94043
  30  */
  31 /*
  32  * Copyright (c) 1986 - 1991 by Sun Microsystems, Inc.
  33  */
  34
  35 /* #ident       "@(#)check_bound.c      1.15    93/07/05 SMI" */
  36
  37 #if 0
  38 #ifndef lint
  39 static  char sccsid[] = "@(#)check_bound.c 1.11 89/04/21 Copyr 1989 Sun Micro";
  40 #endif
  41 #endif
  42
  43 /*
  44  * check_bound.c
  45  * Checks to see whether the program is still bound to the
  46  * claimed address and returns the univeral merged address
  47  *
  48  */
  49
  50 #include <sys/types.h>
  51 #include <sys/socket.h>
  52 #include <rpc/rpc.h>
  53 #include <stdio.h>
  54 #include <netconfig.h>
  55 #include <syslog.h>
  56 #include <string.h>
  57 #include <unistd.h>
  58 #include <stdlib.h>
  59
  60 #include "rpcbind.h"
  61
  62 struct fdlist {
  63         int fd;
  64         struct netconfig *nconf;
  65         struct fdlist *next;
  66         int check_binding;
  67 };
  68
  69 static struct fdlist *fdhead;   /* Link list of the check fd's */
  70 static struct fdlist *fdtail;
  71 static const char emptystring[] = "";
  72
  73 static bool_t check_bound(struct fdlist *, const char *uaddr);
  74
  75 /*
  76  * Returns 1 if the given address is bound for the given addr & transport
  77  * For all error cases, we assume that the address is bound
  78  * Returns 0 for success.
  79  */
  80 static bool_t
  81 check_bound(struct fdlist *fdl, const char *uaddr)
  82 {
  83         int fd;
  84         struct netbuf *na;
  85         int ans;
  86
  87         if (fdl->check_binding == FALSE)
  88                 return (TRUE);
  89
  90         na = uaddr2taddr(fdl->nconf, uaddr);
  91         if (!na)
  92                 return (TRUE); /* punt, should never happen */
  93
  94         fd = __rpc_nconf2fd(fdl->nconf);
  95         if (fd < 0) {
  96                 free(na);
  97                 return (TRUE);
  98         }
  99
 100         ans = bind(fd, (struct sockaddr *)na->buf, na->len);
 101
 102         close(fd);
 103         free(na);
 104
 105         return (ans == 0 ? FALSE : TRUE);
 106 }
 107
 108 int
 109 add_bndlist(struct netconfig *nconf, struct netbuf *baddr)
 110 {
 111         struct fdlist *fdl;
 112         struct netconfig *newnconf;
 113
 114         newnconf = getnetconfigent(nconf->nc_netid);
 115         if (newnconf == NULL)
 116                 return (-1);
 117         fdl = (struct fdlist *)malloc((u_int)sizeof (struct fdlist));
 118         if (fdl == NULL) {
 119                 freenetconfigent(newnconf);
 120                 syslog(LOG_ERR, "no memory!");
 121                 return (-1);
 122         }
 123         fdl->nconf = newnconf;
 124         fdl->next = NULL;
 125         if (fdhead == NULL) {
 126                 fdhead = fdl;
 127                 fdtail = fdl;
 128         } else {
 129                 fdtail->next = fdl;
 130                 fdtail = fdl;
 131         }
 132         /* XXX no bound checking for now */
 133         fdl->check_binding = FALSE;
 134
 135         return 0;
 136 }
 137
 138 bool_t
 139 is_bound(const char *netid, const char *uaddr)
 140 {
 141         struct fdlist *fdl;
 142
 143         for (fdl = fdhead; fdl; fdl = fdl->next)
 144                 if (strcmp(fdl->nconf->nc_netid, netid) == 0)
 145                         break;
 146         if (fdl == NULL)
 147                 return (TRUE);
 148         return (check_bound(fdl, uaddr));
 149 }
 150
 151 /*
 152  * Returns NULL if there was some system error.
 153  * Returns "" if the address was not bound, i.e the server crashed.
 154  * Returns the merged address otherwise.
 155  */
 156 char *
 157 mergeaddr(SVCXPRT *xprt, char *netid, char *uaddr, char *saddr)
 158 {
 159         struct fdlist *fdl;
 160         char *c_uaddr, *s_uaddr, *m_uaddr, *allocated_uaddr = NULL;
 161
 162         for (fdl = fdhead; fdl; fdl = fdl->next)
 163                 if (strcmp(fdl->nconf->nc_netid, netid) == 0)
 164                         break;
 165         if (fdl == NULL)
 166                 return (NULL);
 167         if (check_bound(fdl, uaddr) == FALSE)
 168                 /* that server died */
 169                 return strdup(emptystring);
 170         /*
 171          * If saddr is not NULL, the remote client may have included the
 172          * address by which it contacted us.  Use that for the "client" uaddr,
 173          * otherwise use the info from the SVCXPRT.
 174          */
 175         if (saddr != NULL) {
 176                 c_uaddr = saddr;
 177         } else {
 178                 c_uaddr = taddr2uaddr(fdl->nconf, svc_getrpccaller(xprt));
 179                 if (c_uaddr == NULL) {
 180                         syslog(LOG_ERR, "taddr2uaddr failed for %s",
 181                                 fdl->nconf->nc_netid);
 182                         return (NULL);
 183                 }
 184                 allocated_uaddr = c_uaddr;
 185         }
 186
 187 #ifdef RPCBIND_DEBUG
 188         if (debugging) {
 189                 if (saddr == NULL) {
 190                         fprintf(stderr, "mergeaddr: client uaddr = %s\n",
 191                             c_uaddr);
 192                 } else {
 193                         fprintf(stderr, "mergeaddr: contact uaddr = %s\n",
 194                             c_uaddr);
 195                 }
 196         }
 197 #endif
 198         s_uaddr = uaddr;
 199         /*
 200          * This is all we should need for IP 4 and 6
 201          */
 202         m_uaddr = addrmerge(svc_getrpccaller(xprt), s_uaddr, c_uaddr, netid);
 203 #ifdef RPCBIND_DEBUG
 204         if (debugging)
 205                 fprintf(stderr, "mergeaddr: uaddr = %s, merged uaddr = %s\n",
 206                                 uaddr, m_uaddr);
 207 #endif
 208         if (allocated_uaddr != NULL)
 209                 free(allocated_uaddr);
 210         return (m_uaddr);
 211 }
 212
 213 /*
 214  * Returns a netconf structure from its internal list.  This
 215  * structure should not be freed.
 216  */
 217 struct netconfig *
 218 rpcbind_get_conf(const char *netid)
 219 {
 220         struct fdlist *fdl;
 221
 222         for (fdl = fdhead; fdl; fdl = fdl->next)
 223                 if (strcmp(fdl->nconf->nc_netid, netid) == 0)
 224                         break;
 225         if (fdl == NULL)
 226                 return (NULL);
 227         return (fdl->nconf);
 228 }