res_update.c

   1 #ifndef __APPLE__
   2 #if !defined(lint) && !defined(SABER)
   3 static const char rcsid[] = "$Id: res_update.c,v 1.1 2006/03/01 19:01:39 majka Exp $";
   4 #endif /* not lint */
   5 #endif
   6
   7 /*
   8  * Copyright (c) 1996-1999 by Internet Software Consortium.
   9  *
  10  * Permission to use, copy, modify, and distribute this software for any
  11  * purpose with or without fee is hereby granted, provided that the above
  12  * copyright notice and this permission notice appear in all copies.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  15  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  17  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  18  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  19  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  20  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  21  * SOFTWARE.
  22  */
  23
  24 /*
  25  * Based on the Dynamic DNS reference implementation by Viraj Bais
  26  * <viraj_bais@ccm.fm.intel.com>
  27  */
  28
  29 #ifndef __APPLE__
  30 #include "port_before.h"
  31 #endif
  32
  33 #include <sys/param.h>
  34 #include <sys/socket.h>
  35 #include <sys/time.h>
  36
  37 #include <netinet/in.h>
  38 #include <arpa/inet.h>
  39 #include <arpa/nameser.h>
  40
  41 #include <errno.h>
  42 #include <limits.h>
  43 #include <netdb.h>
  44 #include <res_update.h>
  45 #include <stdarg.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49
  50 #include <resolv.h>
  51
  52 #ifndef __APPLE__
  53 #include <isc/list.h>
  54 #include "port_after.h"
  55 #endif
  56 #include "res_private.h"
  57
  58 /*
  59  * Separate a linked list of records into groups so that all records
  60  * in a group will belong to a single zone on the nameserver.
  61  * Create a dynamic update packet for each zone and send it to the
  62  * nameservers for that zone, and await answer.
  63  * Abort if error occurs in updating any zone.
  64  * Return the number of zones updated on success, < 0 on error.
  65  *
  66  * On error, caller must deal with the unsynchronized zones
  67  * eg. an A record might have been successfully added to the forward
  68  * zone but the corresponding PTR record would be missing if error
  69  * was encountered while updating the reverse zone.
  70  */
  71
  72 struct zonegrp {
  73         char                    z_origin[NS_MAXDNAME];
  74         ns_class                z_class;
  75         union res_sockaddr_union z_nsaddrs[MAXNS];
  76         int                     z_nscount;
  77         int                     z_flags;
  78         LIST(ns_updrec)         z_rrlist;
  79         LINK(struct zonegrp)    z_link;
  80 };
  81
  82 #define ZG_F_ZONESECTADDED      0x0001
  83
  84 /* Forward. */
  85
  86 static void     res_dprintf(const char *, ...);
  87
  88 /* Macros. */
  89
  90 #define DPRINTF(x) do {\
  91                 int save_errno = errno; \
  92                 if ((statp->options & RES_DEBUG) != 0) res_dprintf x; \
  93                 errno = save_errno; \
  94         } while (0)
  95
  96 /* Public. */
  97
  98 int
  99 res_nupdate(res_state statp, ns_updrec *rrecp_in, ns_tsig_key *key) {
 100         ns_updrec *rrecp;
 101         u_char answer[NS_PACKETSZ], packet[2*NS_PACKETSZ];
 102         struct zonegrp *zptr, tgrp;
 103         LIST(struct zonegrp) zgrps;
 104         int nzones = 0, nscount = 0, n;
 105         union res_sockaddr_union nsaddrs[MAXNS];
 106
 107         /* Thread all of the updates onto a list of groups. */
 108         INIT_LIST(zgrps);
 109         memset(&tgrp, 0, sizeof (tgrp));
 110         for (rrecp = rrecp_in; rrecp;
 111              rrecp = LINKED(rrecp, r_link) ? NEXT(rrecp, r_link) : NULL) {
 112                 int nscnt;
 113                 /* Find the origin for it if there is one. */
 114                 tgrp.z_class = rrecp->r_class;
 115                 nscnt = res_findzonecut2(statp, rrecp->r_dname, tgrp.z_class,
 116                                          RES_EXHAUSTIVE, tgrp.z_origin,
 117                                          sizeof tgrp.z_origin,
 118                                          tgrp.z_nsaddrs, MAXNS);
 119                 if (nscnt <= 0) {
 120                         DPRINTF(("res_findzonecut failed (%d)", nscnt));
 121                         goto done;
 122                 }
 123                 tgrp.z_nscount = nscnt;
 124                 /* Find the group for it if there is one. */
 125                 for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link))
 126                         if (ns_samename(tgrp.z_origin, zptr->z_origin) == 1 &&
 127                             tgrp.z_class == zptr->z_class)
 128                                 break;
 129                 /* Make a group for it if there isn't one. */
 130                 if (zptr == NULL) {
 131                         zptr = malloc(sizeof *zptr);
 132                         if (zptr == NULL) {
 133                                 DPRINTF(("malloc failed"));
 134                                 goto done;
 135                         }
 136                         *zptr = tgrp;
 137                         zptr->z_flags = 0;
 138                         INIT_LINK(zptr, z_link);
 139                         INIT_LIST(zptr->z_rrlist);
 140                         APPEND(zgrps, zptr, z_link);
 141                 }
 142                 /* Thread this rrecp onto the right group. */
 143                 APPEND(zptr->z_rrlist, rrecp, r_glink);
 144         }
 145
 146         for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link)) {
 147                 /* Construct zone section and prepend it. */
 148                 rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin,
 149                                      zptr->z_class, ns_t_soa, 0);
 150                 if (rrecp == NULL) {
 151                         DPRINTF(("res_mkupdrec failed"));
 152                         goto done;
 153                 }
 154                 PREPEND(zptr->z_rrlist, rrecp, r_glink);
 155                 zptr->z_flags |= ZG_F_ZONESECTADDED;
 156
 157                 /* Marshall the update message. */
 158                 n = res_nmkupdate(statp, HEAD(zptr->z_rrlist),
 159                                   packet, sizeof packet);
 160                 DPRINTF(("res_mkupdate -> %d", n));
 161                 if (n < 0)
 162                         goto done;
 163
 164                 /* Temporarily replace the resolver's nameserver set. */
 165                 nscount = res_getservers(statp, nsaddrs, MAXNS);
 166                 res_setservers(statp, zptr->z_nsaddrs, zptr->z_nscount);
 167
 168                 /* Send the update and remember the result. */
 169                 if (key != NULL)
 170                         n = res_nsendsigned(statp, packet, n, key,
 171                                             answer, sizeof answer);
 172                 else
 173                         n = res_nsend(statp, packet, n, answer, sizeof answer);
 174                 if (n < 0) {
 175                         DPRINTF(("res_nsend: send error, n=%d (%s)\n",
 176                                  n, strerror(errno)));
 177                         goto done;
 178                 }
 179                 if (((HEADER *)answer)->rcode == ns_r_noerror)
 180                         nzones++;
 181
 182                 /* Restore resolver's nameserver set. */
 183                 res_setservers(statp, nsaddrs, nscount);
 184                 nscount = 0;
 185         }
 186  done:
 187         while (!EMPTY(zgrps)) {
 188                 zptr = HEAD(zgrps);
 189                 if ((zptr->z_flags & ZG_F_ZONESECTADDED) != 0)
 190                         res_freeupdrec(HEAD(zptr->z_rrlist));
 191                 UNLINK(zgrps, zptr, z_link);
 192                 free(zptr);
 193         }
 194         if (nscount != 0)
 195                 res_setservers(statp, nsaddrs, nscount);
 196
 197         return (nzones);
 198 }
 199
 200 /* Private. */
 201
 202 static void
 203 res_dprintf(const char *fmt, ...) {
 204         va_list ap;
 205
 206         va_start(ap, fmt);
 207         fputs(";; res_nupdate: ", stderr);
 208         vfprintf(stderr, fmt, ap);
 209         fputc('\n', stderr);
 210         va_end(ap);
 211 }