1#if !defined(lint) && !defined(SABER)
2static const char rcsid[] = "$Id: res_update.c,v 1.13 2005/04/27 04:56:43 sra Exp $";
3#endif /* not lint */
4
5/*
6 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
7 * Copyright (c) 1996-1999 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
22/*! \file
23 * \brief
24 * Based on the Dynamic DNS reference implementation by Viraj Bais
25 * <viraj_bais@ccm.fm.intel.com>
26 */
27
28#include "port_before.h"
29
30#include <sys/param.h>
31#include <sys/socket.h>
32#include <sys/time.h>
33
34#include <netinet/in.h>
35#include <arpa/inet.h>
36#include <arpa/nameser.h>
37
38#include <errno.h>
39#include <limits.h>
40#include <netdb.h>
41#include <res_update.h>
42#include <stdarg.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <string.h>
46
47#include <isc/list.h>
48#include <resolv.h>
49
50#include "port_after.h"
51#include "res_private.h"
52
53/*%
54 * Separate a linked list of records into groups so that all records
55 * in a group will belong to a single zone on the nameserver.
56 * Create a dynamic update packet for each zone and send it to the
57 * nameservers for that zone, and await answer.
58 * Abort if error occurs in updating any zone.
59 * Return the number of zones updated on success, < 0 on error.
60 *
61 * On error, caller must deal with the unsynchronized zones
62 * eg. an A record might have been successfully added to the forward
63 * zone but the corresponding PTR record would be missing if error
64 * was encountered while updating the reverse zone.
65 */
66
67struct zonegrp {
68	char			z_origin[MAXDNAME];
69	ns_class		z_class;
70	union res_sockaddr_union z_nsaddrs[MAXNS];
71	int			z_nscount;
72	int			z_flags;
73	LIST(ns_updrec)		z_rrlist;
74	LINK(struct zonegrp)	z_link;
75};
76
77#define ZG_F_ZONESECTADDED	0x0001
78
79/* Forward. */
80
81static void	res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2);
82
83/* Macros. */
84
85#define DPRINTF(x) do {\
86		int save_errno = errno; \
87		if ((statp->options & RES_DEBUG) != 0U) res_dprintf x; \
88		errno = save_errno; \
89	} while (0)
90
91/* Public. */
92
93int
94res_nupdate(res_state statp, ns_updrec *rrecp_in, ns_tsig_key *key) {
95	ns_updrec *rrecp;
96	u_char answer[PACKETSZ];
97	u_char *packet;
98	struct zonegrp *zptr, tgrp;
99	LIST(struct zonegrp) zgrps;
100	int nzones = 0, nscount = 0, n;
101	union res_sockaddr_union nsaddrs[MAXNS];
102
103	packet = malloc(NS_MAXMSG);
104	if (packet == NULL) {
105		DPRINTF(("malloc failed"));
106		return (0);
107	}
108	/* Thread all of the updates onto a list of groups. */
109	INIT_LIST(zgrps);
110	memset(&tgrp, 0, sizeof (tgrp));
111	for (rrecp = rrecp_in; rrecp;
112	     rrecp = LINKED(rrecp, r_link) ? NEXT(rrecp, r_link) : NULL) {
113		int nscnt;
114		/* Find the origin for it if there is one. */
115		tgrp.z_class = rrecp->r_class;
116		nscnt = res_findzonecut2(statp, rrecp->r_dname, tgrp.z_class,
117					 RES_EXHAUSTIVE, tgrp.z_origin,
118					 sizeof tgrp.z_origin,
119					 tgrp.z_nsaddrs, MAXNS);
120		if (nscnt <= 0) {
121			DPRINTF(("res_findzonecut failed (%d)", nscnt));
122			goto done;
123		}
124		tgrp.z_nscount = nscnt;
125		/* Find the group for it if there is one. */
126		for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link))
127			if (ns_samename(tgrp.z_origin, zptr->z_origin) == 1 &&
128			    tgrp.z_class == zptr->z_class)
129				break;
130		/* Make a group for it if there isn't one. */
131		if (zptr == NULL) {
132			zptr = malloc(sizeof *zptr);
133			if (zptr == NULL) {
134				DPRINTF(("malloc failed"));
135				goto done;
136			}
137			*zptr = tgrp;
138			zptr->z_flags = 0;
139			INIT_LINK(zptr, z_link);
140			INIT_LIST(zptr->z_rrlist);
141			APPEND(zgrps, zptr, z_link);
142		}
143		/* Thread this rrecp onto the right group. */
144		APPEND(zptr->z_rrlist, rrecp, r_glink);
145	}
146
147	for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link)) {
148		/* Construct zone section and prepend it. */
149		rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin,
150				     zptr->z_class, ns_t_soa, 0);
151		if (rrecp == NULL) {
152			DPRINTF(("res_mkupdrec failed"));
153			goto done;
154		}
155		PREPEND(zptr->z_rrlist, rrecp, r_glink);
156		zptr->z_flags |= ZG_F_ZONESECTADDED;
157
158		/* Marshall the update message. */
159		n = res_nmkupdate(statp, HEAD(zptr->z_rrlist),
160				  packet, NS_MAXMSG);
161		DPRINTF(("res_mkupdate -> %d", n));
162		if (n < 0)
163			goto done;
164
165		/* Temporarily replace the resolver's nameserver set. */
166		nscount = res_getservers(statp, nsaddrs, MAXNS);
167		res_setservers(statp, zptr->z_nsaddrs, zptr->z_nscount);
168
169		/* Send the update and remember the result. */
170		if (key != NULL)
171			n = res_nsendsigned(statp, packet, n, key,
172					    answer, sizeof answer);
173		else
174			n = res_nsend(statp, packet, n, answer, sizeof answer);
175		if (n < 0) {
176			DPRINTF(("res_nsend: send error, n=%d (%s)\n",
177				 n, strerror(errno)));
178			goto done;
179		}
180		if (((HEADER *)answer)->rcode == NOERROR)
181			nzones++;
182
183		/* Restore resolver's nameserver set. */
184		res_setservers(statp, nsaddrs, nscount);
185		nscount = 0;
186	}
187 done:
188	while (!EMPTY(zgrps)) {
189		zptr = HEAD(zgrps);
190		if ((zptr->z_flags & ZG_F_ZONESECTADDED) != 0)
191			res_freeupdrec(HEAD(zptr->z_rrlist));
192		UNLINK(zgrps, zptr, z_link);
193		free(zptr);
194	}
195	if (nscount != 0)
196		res_setservers(statp, nsaddrs, nscount);
197
198	free(packet);
199	return (nzones);
200}
201
202/* Private. */
203
204static void
205res_dprintf(const char *fmt, ...) {
206	va_list ap;
207
208	va_start(ap, fmt);
209	fputs(";; res_nupdate: ", stderr);
210	vfprintf(stderr, fmt, ap);
211	fputc('\n', stderr);
212	va_end(ap);
213}
214