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
63struct 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
77static 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
89int
90res_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
200static void
201res_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