1 /* $NetBSD: res_update.c,v 1.2 2022/04/19 20:32:17 rillig Exp $ */ 2 3 /* 4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (c) 1996-1999 by Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 /*! \file 21 * \brief 22 * Based on the Dynamic DNS reference implementation by Viraj Bais 23 * <viraj_bais@ccm.fm.intel.com> 24 */ 25 #include <sys/cdefs.h> 26 #if 0 27 static const char rcsid[] = "Id: res_update.c,v 1.13 2005/04/27 04:56:43 sra Exp "; 28 #else 29 __RCSID("$NetBSD: res_update.c,v 1.2 2022/04/19 20:32:17 rillig Exp $"); 30 #endif 31 32 33 #include "port_before.h" 34 35 #include <sys/param.h> 36 #include <sys/socket.h> 37 #include <sys/time.h> 38 39 #include <netinet/in.h> 40 #include <arpa/inet.h> 41 #include <arpa/nameser.h> 42 43 #include <errno.h> 44 #include <limits.h> 45 #include <netdb.h> 46 #include <res_update.h> 47 #include <stdarg.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 52 #include <isc/list.h> 53 #include <resolv.h> 54 55 #include "port_after.h" 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[MAXDNAME]; 74 ns_class z_class; 75 union res_sockaddr_union z_nsaddrs[MAXNS]; 76 int z_nscount; 77 int z_flags; 78 TAILQ_HEAD(, ns_updrec) z_rrlist; 79 TAILQ_ENTRY(zonegrp) z_link; 80 }; 81 82 #define ZG_F_ZONESECTADDED 0x0001 83 84 /* Forward. */ 85 86 static void res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2); 87 88 /* Macros. */ 89 90 #define DPRINTF(x) do {\ 91 int save_errno = errno; \ 92 if ((statp->options & RES_DEBUG) != 0U) 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[PACKETSZ]; 102 u_char *packet; 103 struct zonegrp *zptr, tgrp; 104 TAILQ_HEAD(, zonegrp) zgrps; 105 int nzones = 0, nscount = 0, n; 106 union res_sockaddr_union nsaddrs[MAXNS]; 107 108 packet = malloc(NS_MAXMSG); 109 if (packet == NULL) { 110 DPRINTF(("malloc failed")); 111 return (0); 112 } 113 /* Thread all of the updates onto a list of groups. */ 114 TAILQ_INIT(&zgrps); 115 memset(&tgrp, 0, sizeof (tgrp)); 116 for (rrecp = rrecp_in; rrecp; rrecp = TAILQ_NEXT(rrecp, r_link)) { 117 int nscnt; 118 /* Find the origin for it if there is one. */ 119 tgrp.z_class = rrecp->r_class; 120 nscnt = res_findzonecut2(statp, rrecp->r_dname, tgrp.z_class, 121 RES_EXHAUSTIVE, tgrp.z_origin, 122 sizeof tgrp.z_origin, 123 tgrp.z_nsaddrs, MAXNS); 124 if (nscnt <= 0) { 125 DPRINTF(("res_findzonecut failed (%d)", nscnt)); 126 goto done; 127 } 128 tgrp.z_nscount = nscnt; 129 /* Find the group for it if there is one. */ 130 TAILQ_FOREACH(zptr, &zgrps, z_link) 131 if (ns_samename(tgrp.z_origin, zptr->z_origin) == 1 && 132 tgrp.z_class == zptr->z_class) 133 break; 134 /* Make a group for it if there isn't one. */ 135 if (zptr == NULL) { 136 zptr = malloc(sizeof *zptr); 137 if (zptr == NULL) { 138 DPRINTF(("malloc failed")); 139 goto done; 140 } 141 *zptr = tgrp; 142 zptr->z_flags = 0; 143 TAILQ_INIT(&zptr->z_rrlist); 144 TAILQ_INSERT_TAIL(&zgrps, zptr, z_link); 145 } 146 /* Thread this rrecp onto the right group. */ 147 TAILQ_INSERT_TAIL(&zptr->z_rrlist, rrecp, r_glink); 148 } 149 150 TAILQ_FOREACH(zptr, &zgrps, z_link) { 151 HEADER h; 152 /* Construct zone section and prepend it. */ 153 rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin, 154 (u_int)zptr->z_class, ns_t_soa, 0); 155 if (rrecp == NULL) { 156 DPRINTF(("res_mkupdrec failed")); 157 goto done; 158 } 159 TAILQ_INSERT_HEAD(&zptr->z_rrlist, rrecp, r_glink); 160 zptr->z_flags |= ZG_F_ZONESECTADDED; 161 162 /* Marshall the update message. */ 163 n = res_nmkupdate(statp, TAILQ_FIRST(&zptr->z_rrlist), 164 packet, NS_MAXMSG); 165 DPRINTF(("res_mkupdate -> %d", n)); 166 if (n < 0) 167 goto done; 168 169 /* Temporarily replace the resolver's nameserver set. */ 170 nscount = res_getservers(statp, nsaddrs, MAXNS); 171 res_setservers(statp, zptr->z_nsaddrs, zptr->z_nscount); 172 173 /* Send the update and remember the result. */ 174 if (key != NULL) 175 n = res_nsendsigned(statp, packet, n, key, 176 answer, (int)sizeof answer); 177 else 178 n = res_nsend(statp, packet, n, answer, 179 (int)sizeof answer); 180 if (n < 0) { 181 DPRINTF(("res_nsend: send error, n=%d (%s)\n", 182 n, strerror(errno))); 183 goto done; 184 } 185 memcpy(&h, answer, sizeof(h)); 186 if (h.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 (!TAILQ_EMPTY(&zgrps)) { 195 zptr = TAILQ_FIRST(&zgrps); 196 if ((zptr->z_flags & ZG_F_ZONESECTADDED) != 0) 197 res_freeupdrec(TAILQ_FIRST(&zptr->z_rrlist)); 198 TAILQ_REMOVE(&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 } 220