lib/libc/resolv/res_update.c

   1 /*
   2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (c) 1996-1999 by Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  *
  17  * $Id: res_update.c,v 1.13 2005/04/27 04:56:43 sra Exp $
  18  */
  19
  20 /*! \file
  21  * \brief
  22  * Based on the Dynamic DNS reference implementation by Viraj Bais
  23  * &lt;viraj_bais@ccm.fm.intel.com>
  24  */
  25
  26 #include "port_before.h"
  27
  28 #include <sys/param.h>
  29 #include <sys/socket.h>
  30 #include <sys/time.h>
  31
  32 #include <netinet/in.h>
  33 #include <arpa/inet.h>
  34 #include <arpa/nameser.h>
  35
  36 #include <errno.h>
  37 #include <limits.h>
  38 #include <netdb.h>
  39 #include <res_update.h>
  40 #include <stdarg.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44
  45 #include "isc/list.h"
  46 #include <resolv.h>
  47
  48 #include "port_after.h"
  49 #include "res_private.h"
  50
  51 /*%
  52  * Separate a linked list of records into groups so that all records
  53  * in a group will belong to a single zone on the nameserver.
  54  * Create a dynamic update packet for each zone and send it to the
  55  * nameservers for that zone, and await answer.
  56  * Abort if error occurs in updating any zone.
  57  * Return the number of zones updated on success, < 0 on error.
  58  *
  59  * On error, caller must deal with the unsynchronized zones
  60  * eg. an A record might have been successfully added to the forward
  61  * zone but the corresponding PTR record would be missing if error
  62  * was encountered while updating the reverse zone.
  63  */
  64
  65 struct zonegrp {
  66         char                    z_origin[MAXDNAME];
  67         ns_class                z_class;
  68         union res_sockaddr_union z_nsaddrs[MAXNS];
  69         int                     z_nscount;
  70         int                     z_flags;
  71         LIST(ns_updrec)         z_rrlist;
  72         LINK(struct zonegrp)    z_link;
  73 };
  74
  75 #define ZG_F_ZONESECTADDED      0x0001
  76
  77 /* Forward. */
  78
  79 static void     res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2);
  80
  81 /* Macros. */
  82
  83 #define DPRINTF(x) do {\
  84                 int save_errno = errno; \
  85                 if ((statp->options & RES_DEBUG) != 0U) res_dprintf x; \
  86                 errno = save_errno; \
  87         } while (0)
  88
  89 /* Public. */
  90
  91 int
  92 res_nupdate(res_state statp, ns_updrec *rrecp_in, ns_tsig_key *key) {
  93         ns_updrec *rrecp;
  94         u_char answer[PACKETSZ];
  95         u_char *packet;
  96         struct zonegrp *zptr, tgrp;
  97         LIST(struct zonegrp) zgrps;
  98         int nzones = 0, nscount = 0, n;
  99         union res_sockaddr_union nsaddrs[MAXNS];
 100
 101         packet = malloc(NS_MAXMSG);
 102         if (packet == NULL) {
 103                 DPRINTF(("malloc failed"));
 104                 return (0);
 105         }
 106         /* Thread all of the updates onto a list of groups. */
 107         INIT_LIST(zgrps);
 108         memset(&tgrp, 0, sizeof (tgrp));
 109         for (rrecp = rrecp_in; rrecp;
 110              rrecp = LINKED(rrecp, r_link) ? NEXT(rrecp, r_link) : NULL) {
 111                 int nscnt;
 112                 /* Find the origin for it if there is one. */
 113                 tgrp.z_class = rrecp->r_class;
 114                 nscnt = res_findzonecut2(statp, rrecp->r_dname, tgrp.z_class,
 115                                          RES_EXHAUSTIVE, tgrp.z_origin,
 116                                          sizeof tgrp.z_origin,
 117                                          tgrp.z_nsaddrs, MAXNS);
 118                 if (nscnt <= 0) {
 119                         DPRINTF(("res_findzonecut failed (%d)", nscnt));
 120                         goto done;
 121                 }
 122                 tgrp.z_nscount = nscnt;
 123                 /* Find the group for it if there is one. */
 124                 for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link))
 125                         if (ns_samename(tgrp.z_origin, zptr->z_origin) == 1 &&
 126                             tgrp.z_class == zptr->z_class)
 127                                 break;
 128                 /* Make a group for it if there isn't one. */
 129                 if (zptr == NULL) {
 130                         zptr = malloc(sizeof *zptr);
 131                         if (zptr == NULL) {
 132                                 DPRINTF(("malloc failed"));
 133                                 goto done;
 134                         }
 135                         *zptr = tgrp;
 136                         zptr->z_flags = 0;
 137                         INIT_LINK(zptr, z_link);
 138                         INIT_LIST(zptr->z_rrlist);
 139                         APPEND(zgrps, zptr, z_link);
 140                 }
 141                 /* Thread this rrecp onto the right group. */
 142                 APPEND(zptr->z_rrlist, rrecp, r_glink);
 143         }
 144
 145         for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link)) {
 146                 /* Construct zone section and prepend it. */
 147                 rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin,
 148                                      zptr->z_class, ns_t_soa, 0);
 149                 if (rrecp == NULL) {
 150                         DPRINTF(("res_mkupdrec failed"));
 151                         goto done;
 152                 }
 153                 PREPEND(zptr->z_rrlist, rrecp, r_glink);
 154                 zptr->z_flags |= ZG_F_ZONESECTADDED;
 155
 156                 /* Marshall the update message. */
 157                 n = res_nmkupdate(statp, HEAD(zptr->z_rrlist),
 158                                   packet, NS_MAXMSG);
 159                 DPRINTF(("res_mkupdate -> %d", n));
 160                 if (n < 0)
 161                         goto done;
 162
 163                 /* Temporarily replace the resolver's nameserver set. */
 164                 nscount = res_getservers(statp, nsaddrs, MAXNS);
 165                 res_setservers(statp, zptr->z_nsaddrs, zptr->z_nscount);
 166
 167                 /* Send the update and remember the result. */
 168                 if (key != NULL)
 169 #ifdef _LIBC
 170                 {
 171                         DPRINTF(("TSIG is not supported\n"));
 172                         RES_SET_H_ERRNO(statp, NO_RECOVERY);
 173                         goto done;
 174                 }
 175 #else
 176                         n = res_nsendsigned(statp, packet, n, key,
 177                                             answer, sizeof answer);
 178 #endif
 179                 else
 180                         n = res_nsend(statp, packet, n, answer, sizeof answer);
 181                 if (n < 0) {
 182                         DPRINTF(("res_nsend: send error, n=%d (%s)\n",
 183                                  n, strerror(errno)));
 184                         goto done;
 185                 }
 186                 if (((HEADER *)answer)->rcode == NOERROR)
 187                         nzones++;
 188
 189                 /* Restore resolver's nameserver set. */
 190                 res_setservers(statp, nsaddrs, nscount);
 191                 nscount = 0;
 192         }
 193  done:
 194         while (!EMPTY(zgrps)) {
 195                 zptr = HEAD(zgrps);
 196                 if ((zptr->z_flags & ZG_F_ZONESECTADDED) != 0)
 197                         res_freeupdrec(HEAD(zptr->z_rrlist));
 198                 UNLINK(zgrps, zptr, z_link);
 199                 free(zptr);
 200         }
 201         if (nscount != 0)
 202                 res_setservers(statp, nsaddrs, nscount);
 203
 204         free(packet);
 205         return (nzones);
 206 }
 207
 208 /* Private. */
 209
 210 static void
 211 res_dprintf(const char *fmt, ...) {
 212         va_list ap;
 213
 214         va_start(ap, fmt);
 215         fputs(";; res_nupdate: ", stderr);
 216         vfprintf(stderr, fmt, ap);
 217         fputc('\n', stderr);
 218         va_end(ap);
 219 }