dist/dhcp/minires/res_update.c

   1 #if !defined(lint) && !defined(SABER)
   2 static const char rcsid[] = "$Id: res_update.c,v 1.3 2005/08/11 17:13:26 drochner Exp $";
   3 #endif /* not lint */
   4
   5 /*
   6  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
   7  * Copyright (c) 1996-2003 by Internet Software Consortium
   8  *
   9  * Permission to use, copy, modify, and distribute this software for any
  10  * purpose with or without fee is hereby granted, provided that the above
  11  * copyright notice and this permission notice appear in all copies.
  12  *
  13  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  14  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  15  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  16  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  17  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  18  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  19  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  20  *
  21  *   Internet Systems Consortium, Inc.
  22  *   950 Charter Street
  23  *   Redwood City, CA 94063
  24  *   <info@isc.org>
  25  *   http://www.isc.org/
  26  */
  27
  28 /*
  29  * Based on the Dynamic DNS reference implementation by Viraj Bais
  30  * <viraj_bais@ccm.fm.intel.com>
  31  */
  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
  40 #include <errno.h>
  41 #include <limits.h>
  42 #include <netdb.h>
  43 #include <stdarg.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47
  48 #include <isc-dhcp/list.h>
  49 #include "minires/minires.h"
  50 #include "arpa/nameser.h"
  51
  52 /*
  53  * Separate a linked list of records into groups so that all records
  54  * in a group will belong to a single zone on the nameserver.
  55  * Create a dynamic update packet for each zone and send it to the
  56  * nameservers for that zone, and await answer.
  57  * Abort if error occurs in updating any zone.
  58  * Return the number of zones updated on success, < 0 on error.
  59  *
  60  * On error, caller must deal with the unsynchronized zones
  61  * eg. an A record might have been successfully added to the forward
  62  * zone but the corresponding PTR record would be missing if error
  63  * was encountered while updating the reverse zone.
  64  */
  65
  66 struct zonegrp {
  67         char z_origin[MAXDNAME];
  68         ns_class z_class;
  69         struct in_addr z_nsaddrs[MAXNS];
  70         int z_nscount;
  71         int z_flags;
  72         ISC_LIST(ns_updrec) z_rrlist;
  73         ISC_LINK(struct zonegrp) z_link;
  74 };
  75
  76 #define ZG_F_ZONESECTADDED      0x0001
  77
  78 /* Forward. */
  79
  80 static int      nscopy(struct sockaddr_in *, const struct sockaddr_in *, int);
  81 static int      nsprom(struct sockaddr_in *, const struct in_addr *, int);
  82
  83 void tkey_free (ns_tsig_key **);
  84
  85 isc_result_t
  86 res_nupdate(res_state statp, ns_updrec *rrecp_in) {
  87         ns_updrec *rrecp;
  88         double answer[PACKETSZ / sizeof (double)];
  89         double packet[2*PACKETSZ / sizeof (double)];
  90         struct zonegrp *zptr, tgrp;
  91         int nscount = 0;
  92         unsigned n;
  93         unsigned rval;
  94         struct sockaddr_in nsaddrs[MAXNS];
  95         ns_tsig_key *key;
  96         void *zcookie = 0;
  97         void *zcookp = &zcookie;
  98         isc_result_t rcode;
  99
 100       again:
 101         /* Make sure all the updates are in the same zone, and find out
 102            what zone they are in. */
 103         zptr = NULL;
 104         for (rrecp = rrecp_in; rrecp; rrecp = ISC_LIST_NEXT(rrecp, r_link)) {
 105                 /* Find the origin for it if there is one. */
 106                 tgrp.z_class = rrecp->r_class;
 107                 rcode = res_findzonecut(statp, rrecp->r_dname, tgrp.z_class,
 108                                         RES_EXHAUSTIVE,
 109                                         tgrp.z_origin,
 110                                         sizeof tgrp.z_origin,
 111                                         tgrp.z_nsaddrs, MAXNS, &tgrp.z_nscount,
 112                                         zcookp);
 113                 if (rcode != ISC_R_SUCCESS)
 114                         goto done;
 115                 if (tgrp.z_nscount <= 0) {
 116                         rcode = ISC_R_NOTZONE;
 117                         goto done;
 118                 }
 119                 /* Make a group for it if there isn't one. */
 120                 if (zptr == NULL) {
 121                         zptr = malloc(sizeof *zptr);
 122                         if (zptr == NULL) {
 123                                 rcode = ISC_R_NOMEMORY;
 124                                 goto done;
 125                         }
 126                         *zptr = tgrp;
 127                         zptr->z_flags = 0;
 128                         ISC_LIST_INIT(zptr->z_rrlist);
 129                 } else if (ns_samename(tgrp.z_origin, zptr->z_origin) == 0 ||
 130                            tgrp.z_class != zptr->z_class) {
 131                         /* Some of the records are in different zones. */
 132                         rcode = ISC_R_CROSSZONE;
 133                         goto done;
 134                 }
 135                 /* Thread this rrecp onto the zone group. */
 136                 ISC_LIST_APPEND(zptr->z_rrlist, rrecp, r_glink);
 137         }
 138
 139         /* Construct zone section and prepend it. */
 140         rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin,
 141                              zptr->z_class, ns_t_soa, 0);
 142         if (rrecp == NULL) {
 143                 rcode = ISC_R_UNEXPECTED;
 144                 goto done;
 145         }
 146         ISC_LIST_PREPEND(zptr->z_rrlist, rrecp, r_glink);
 147         zptr->z_flags |= ZG_F_ZONESECTADDED;
 148
 149         /* Marshall the update message. */
 150         n = sizeof packet;
 151         rcode = res_nmkupdate(statp,
 152                               ISC_LIST_HEAD(zptr->z_rrlist), packet, &n);
 153         if (rcode != ISC_R_SUCCESS)
 154                 goto done;
 155
 156         /* Temporarily replace the resolver's nameserver set. */
 157         nscount = nscopy(nsaddrs, statp->nsaddr_list, statp->nscount);
 158         statp->nscount = nsprom(statp->nsaddr_list,
 159                                 zptr->z_nsaddrs, zptr->z_nscount);
 160
 161         /* Send the update and remember the result. */
 162         key = (ns_tsig_key *)0;
 163         rcode = find_tsig_key (&key, zptr->z_origin, zcookie);
 164         if (rcode == ISC_R_SUCCESS) {
 165                 rcode = res_nsendsigned(statp, packet, n, key,
 166                                         answer, sizeof answer, &rval);
 167                 tkey_free (&key);
 168         } else if (rcode == ISC_R_NOTFOUND || rcode == ISC_R_KEY_UNKNOWN) {
 169                 rcode = res_nsend(statp, packet, n,
 170                                   answer, sizeof answer, &rval);
 171         }
 172         if (rcode != ISC_R_SUCCESS)
 173                 goto undone;
 174
 175         rcode = ns_rcode_to_isc (((HEADER *)answer)->rcode);
 176         if (zcookie && rcode == ISC_R_BADSIG) {
 177                 repudiate_zone (&zcookie);
 178         }
 179
 180  undone:
 181         /* Restore resolver's nameserver set. */
 182         statp->nscount = nscopy(statp->nsaddr_list, nsaddrs, nscount);
 183         nscount = 0;
 184  done:
 185         if (zptr) {
 186                 if ((zptr->z_flags & ZG_F_ZONESECTADDED) != 0)
 187                         res_freeupdrec(ISC_LIST_HEAD(zptr->z_rrlist));
 188                 free(zptr);
 189         }
 190
 191         /* If the update failed because we used a cached zone and it
 192            didn't work, try it again without the cached zone. */
 193         if (zcookp && (rcode == ISC_R_NOTZONE || rcode == ISC_R_BADSIG)) {
 194                 zcookp = 0;
 195                 goto again;
 196         }
 197
 198         if (zcookie)
 199                 forget_zone (&zcookie);
 200         return rcode;
 201 }
 202
 203 /* Private. */
 204
 205 static int
 206 nscopy(struct sockaddr_in *dst, const struct sockaddr_in *src, int n) {
 207         int i;
 208
 209         for (i = 0; i < n; i++)
 210                 dst[i] = src[i];
 211         return (n);
 212 }
 213
 214 static int
 215 nsprom(struct sockaddr_in *dst, const struct in_addr *src, int n) {
 216         int i;
 217
 218         for (i = 0; i < n; i++) {
 219                 memset(&dst[i], 0, sizeof dst[i]);
 220                 dst[i].sin_family = AF_INET;
 221                 dst[i].sin_port = htons(NS_DEFAULTPORT);
 222                 dst[i].sin_addr = src[i];
 223         }
 224         return (n);
 225 }