usr/src/lib/libresolv2/common/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
  18 /*! \file
  19  * \brief
  20  * Based on the Dynamic DNS reference implementation by Viraj Bais
  21  * &lt;viraj_bais@ccm.fm.intel.com>
  22  */
  23
  24 #include "port_before.h"
  25
  26 #include <sys/param.h>
  27 #include <sys/socket.h>
  28 #include <sys/time.h>
  29
  30 #include <netinet/in.h>
  31 #include <arpa/inet.h>
  32 #include <arpa/nameser.h>
  33
  34 #include <errno.h>
  35 #include <limits.h>
  36 #include <netdb.h>
  37 #include <res_update.h>
  38 #include <stdarg.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42
  43 #include <isc/list.h>
  44 #include <resolv.h>
  45
  46 #include "port_after.h"
  47 #include "res_private.h"
  48
  49 /*%
  50  * Separate a linked list of records into groups so that all records
  51  * in a group will belong to a single zone on the nameserver.
  52  * Create a dynamic update packet for each zone and send it to the
  53  * nameservers for that zone, and await answer.
  54  * Abort if error occurs in updating any zone.
  55  * Return the number of zones updated on success, < 0 on error.
  56  *
  57  * On error, caller must deal with the unsynchronized zones
  58  * eg. an A record might have been successfully added to the forward
  59  * zone but the corresponding PTR record would be missing if error
  60  * was encountered while updating the reverse zone.
  61  */
  62
  63 struct zonegrp {
  64         char                    z_origin[MAXDNAME];
  65         ns_class                z_class;
  66         union res_sockaddr_union z_nsaddrs[MAXNS];
  67         int                     z_nscount;
  68         int                     z_flags;
  69         LIST(ns_updrec)         z_rrlist;
  70         LINK(struct zonegrp)    z_link;
  71 };
  72
  73 #define ZG_F_ZONESECTADDED      0x0001
  74
  75 /* Forward. */
  76
  77 static void     res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2);
  78
  79 /* Macros. */
  80
  81 #define DPRINTF(x) do {\
  82                 int save_errno = errno; \
  83                 if ((statp->options & RES_DEBUG) != 0U) res_dprintf x; \
  84                 errno = save_errno; \
  85         } while (0)
  86
  87 /* Public. */
  88
  89 int
  90 res_nupdate(res_state statp, ns_updrec *rrecp_in, ns_tsig_key *key) {
  91         ns_updrec *rrecp;
  92         u_char answer[PACKETSZ];
  93         u_char *packet;
  94         struct zonegrp *zptr, tgrp;
  95         LIST(struct zonegrp) zgrps;
  96         int nzones = 0, nscount = 0, n;
  97         union res_sockaddr_union nsaddrs[MAXNS];
  98
  99         packet = malloc(NS_MAXMSG);
 100         if (packet == NULL) {
 101                 DPRINTF(("malloc failed"));
 102                 return (0);
 103         }
 104         /* Thread all of the updates onto a list of groups. */
 105         INIT_LIST(zgrps);
 106         memset(&tgrp, 0, sizeof (tgrp));
 107         for (rrecp = rrecp_in; rrecp;
 108              rrecp = LINKED(rrecp, r_link) ? NEXT(rrecp, r_link) : NULL) {
 109                 int nscnt;
 110                 /* Find the origin for it if there is one. */
 111                 tgrp.z_class = rrecp->r_class;
 112                 nscnt = res_findzonecut2(statp, rrecp->r_dname, tgrp.z_class,
 113                                          RES_EXHAUSTIVE, tgrp.z_origin,
 114                                          sizeof tgrp.z_origin,
 115                                          tgrp.z_nsaddrs, MAXNS);
 116                 if (nscnt <= 0) {
 117                         DPRINTF(("res_findzonecut failed (%d)", nscnt));
 118                         goto done;
 119                 }
 120                 tgrp.z_nscount = nscnt;
 121                 /* Find the group for it if there is one. */
 122                 for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link))
 123                         if (ns_samename(tgrp.z_origin, zptr->z_origin) == 1 &&
 124                             tgrp.z_class == zptr->z_class)
 125                                 break;
 126                 /* Make a group for it if there isn't one. */
 127                 if (zptr == NULL) {
 128                         zptr = malloc(sizeof *zptr);
 129                         if (zptr == NULL) {
 130                                 DPRINTF(("malloc failed"));
 131                                 goto done;
 132                         }
 133                         *zptr = tgrp;
 134                         zptr->z_flags = 0;
 135                         INIT_LINK(zptr, z_link);
 136                         INIT_LIST(zptr->z_rrlist);
 137                         APPEND(zgrps, zptr, z_link);
 138                 }
 139                 /* Thread this rrecp onto the right group. */
 140                 APPEND(zptr->z_rrlist, rrecp, r_glink);
 141         }
 142
 143         for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link)) {
 144                 /* Construct zone section and prepend it. */
 145                 rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin,
 146                                      zptr->z_class, ns_t_soa, 0);
 147                 if (rrecp == NULL) {
 148                         DPRINTF(("res_mkupdrec failed"));
 149                         goto done;
 150                 }
 151                 PREPEND(zptr->z_rrlist, rrecp, r_glink);
 152                 zptr->z_flags |= ZG_F_ZONESECTADDED;
 153
 154                 /* Marshall the update message. */
 155                 n = res_nmkupdate(statp, HEAD(zptr->z_rrlist),
 156                                   packet, NS_MAXMSG);
 157                 DPRINTF(("res_mkupdate -> %d", n));
 158                 if (n < 0)
 159                         goto done;
 160
 161                 /* Temporarily replace the resolver's nameserver set. */
 162                 nscount = res_getservers(statp, nsaddrs, MAXNS);
 163                 res_setservers(statp, zptr->z_nsaddrs, zptr->z_nscount);
 164
 165                 /* Send the update and remember the result. */
 166                 if (key != NULL)
 167                         n = res_nsendsigned(statp, packet, n, key,
 168                                             answer, sizeof answer);
 169                 else
 170                         n = res_nsend(statp, packet, n, answer, sizeof answer);
 171                 if (n < 0) {
 172                         DPRINTF(("res_nsend: send error, n=%d (%s)\n",
 173                                  n, strerror(errno)));
 174                         goto done;
 175                 }
 176                 if (((HEADER *)answer)->rcode == NOERROR)
 177                         nzones++;
 178
 179                 /* Restore resolver's nameserver set. */
 180                 res_setservers(statp, nsaddrs, nscount);
 181                 nscount = 0;
 182         }
 183  done:
 184         while (!EMPTY(zgrps)) {
 185                 zptr = HEAD(zgrps);
 186                 if ((zptr->z_flags & ZG_F_ZONESECTADDED) != 0)
 187                         res_freeupdrec(HEAD(zptr->z_rrlist));
 188                 UNLINK(zgrps, zptr, z_link);
 189                 free(zptr);
 190         }
 191         if (nscount != 0)
 192                 res_setservers(statp, nsaddrs, nscount);
 193
 194         free(packet);
 195         return (nzones);
 196 }
 197
 198 /* Private. */
 199
 200 static void
 201 res_dprintf(const char *fmt, ...) {
 202         va_list ap;
 203
 204         va_start(ap, fmt);
 205         fputs(";; res_nupdate: ", stderr);
 206         vfprintf(stderr, fmt, ap);
 207         fputc('\n', stderr);
 208         va_end(ap);
 209 }