1
2 /*-
3 * SPDX-License-Identifier: ISC
4 *
5 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
6 * Copyright (c) 1996-1999 by Internet Software Consortium.
7 *
8 * Permission to use, copy, modify, and distribute this software for any
9 * purpose with or without fee is hereby granted, provided that the above
10 * copyright notice and this permission notice appear in all copies.
11 *
12 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
18 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 */
20
21 /*! \file
22 * \brief
23 * Based on the Dynamic DNS reference implementation by Viraj Bais
24 * <viraj_bais@ccm.fm.intel.com>
25 */
26
27 #include "port_before.h"
28
29 #include <sys/param.h>
30 #include <sys/socket.h>
31 #include <sys/time.h>
32
33 #include <netinet/in.h>
34 #include <arpa/inet.h>
35 #include <arpa/nameser.h>
36
37 #include <errno.h>
38 #include <limits.h>
39 #include <netdb.h>
40 #include <res_update.h>
41 #include <stdarg.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45
46 #include <isc/list.h>
47 #include <resolv.h>
48
49 #include "port_after.h"
50 #include "res_private.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 union res_sockaddr_union z_nsaddrs[MAXNS];
70 int z_nscount;
71 int z_flags;
72 LIST(ns_updrec) z_rrlist;
73 LINK(struct zonegrp) z_link;
74 };
75
76 #define ZG_F_ZONESECTADDED 0x0001
77
78 /* Forward. */
79
80 static void res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2);
81
82 /* Macros. */
83
84 #define DPRINTF(x) do {\
85 int save_errno = errno; \
86 if ((statp->options & RES_DEBUG) != 0U) res_dprintf x; \
87 errno = save_errno; \
88 } while (0)
89
90 /* Public. */
91
92 int
res_nupdate(res_state statp,ns_updrec * rrecp_in,ns_tsig_key * key)93 res_nupdate(res_state statp, ns_updrec *rrecp_in, ns_tsig_key *key) {
94 ns_updrec *rrecp;
95 u_char answer[PACKETSZ];
96 u_char *packet;
97 struct zonegrp *zptr, tgrp;
98 LIST(struct zonegrp) zgrps;
99 int nzones = 0, nscount = 0, n;
100 union res_sockaddr_union nsaddrs[MAXNS];
101
102 packet = malloc(NS_MAXMSG);
103 if (packet == NULL) {
104 DPRINTF(("malloc failed"));
105 return (0);
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, NS_MAXMSG);
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 #ifdef _LIBC
171 DPRINTF(("TSIG is not supported\n"));
172 RES_SET_H_ERRNO(statp, NO_RECOVERY);
173 goto done;
174 #else
175 n = res_nsendsigned(statp, packet, n, key,
176 answer, sizeof answer);
177 #endif
178 } else
179 n = res_nsend(statp, packet, n, answer, 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 if (((HEADER *)answer)->rcode == NOERROR)
186 nzones++;
187
188 /* Restore resolver's nameserver set. */
189 res_setservers(statp, nsaddrs, nscount);
190 nscount = 0;
191 }
192 done:
193 while (!EMPTY(zgrps)) {
194 zptr = HEAD(zgrps);
195 if ((zptr->z_flags & ZG_F_ZONESECTADDED) != 0)
196 res_freeupdrec(HEAD(zptr->z_rrlist));
197 UNLINK(zgrps, zptr, z_link);
198 free(zptr);
199 }
200 if (nscount != 0)
201 res_setservers(statp, nsaddrs, nscount);
202
203 free(packet);
204 return (nzones);
205 }
206
207 /* Private. */
208
209 static void
res_dprintf(const char * fmt,...)210 res_dprintf(const char *fmt, ...) {
211 va_list ap;
212
213 va_start(ap, fmt);
214 fputs(";; res_nupdate: ", stderr);
215 vfprintf(stderr, fmt, ap);
216 fputc('\n', stderr);
217 va_end(ap);
218 }
219