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 * <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
res_nupdate(res_state statp,ns_updrec * rrecp_in,ns_tsig_key * key)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
res_dprintf(const char * fmt,...)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 }
210