res_update.c revision 158787 
1#if !defined(lint) && !defined(SABER)
2static const char rcsid[] = "$Id: res_update.c,v 1.6.2.4.4.2 2004/03/16 12:34:20 marka Exp $";
3#endif /* not lint */
4
5/*
6 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
7 * Copyright (c) 1996-1999 by Internet Software Consortium.
8 *
9 * Permission to use, copy, modify, and distribute this software for any
10 * purpose with or without fee is hereby granted, provided that the above
11 * copyright notice and this permission notice appear in all copies.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
14 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
16 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
19 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20 */
21
22/*
23 * Based on the Dynamic DNS reference implementation by Viraj Bais
24 * <viraj_bais@ccm.fm.intel.com>
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/lib/libc/resolv/res_update.c 158787 2006-05-21 11:19:36Z ume $");
29
30#include "port_before.h"
31
32#include <sys/param.h>
33#include <sys/socket.h>
34#include <sys/time.h>
35
36#include <netinet/in.h>
37#include <arpa/inet.h>
38#include <arpa/nameser.h>
39
40#include <errno.h>
41#include <limits.h>
42#include <netdb.h>
43#include <res_update.h>
44#include <stdarg.h>
45#include <stdio.h>
46#include <stdlib.h>
47#include <string.h>
48
49#include <isc/list.h>
50#include <resolv.h>
51
52#include "port_after.h"
53#include "res_private.h"
54
55/*
56 * Separate a linked list of records into groups so that all records
57 * in a group will belong to a single zone on the nameserver.
58 * Create a dynamic update packet for each zone and send it to the
59 * nameservers for that zone, and await answer.
60 * Abort if error occurs in updating any zone.
61 * Return the number of zones updated on success, < 0 on error.
62 *
63 * On error, caller must deal with the unsynchronized zones
64 * eg. an A record might have been successfully added to the forward
65 * zone but the corresponding PTR record would be missing if error
66 * was encountered while updating the reverse zone.
67 */
68
69struct zonegrp {
70	char			z_origin[MAXDNAME];
71	ns_class		z_class;
72	union res_sockaddr_union z_nsaddrs[MAXNS];
73	int			z_nscount;
74	int			z_flags;
75	LIST(ns_updrec)		z_rrlist;
76	LINK(struct zonegrp)	z_link;
77};
78
79#define ZG_F_ZONESECTADDED	0x0001
80
81/* Forward. */
82
83static void	res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2);
84
85/* Macros. */
86
87#define DPRINTF(x) do {\
88		int save_errno = errno; \
89		if ((statp->options & RES_DEBUG) != 0U) res_dprintf x; \
90		errno = save_errno; \
91	} while (0)
92
93/* Public. */
94
95int
96res_nupdate(res_state statp, ns_updrec *rrecp_in, ns_tsig_key *key) {
97	ns_updrec *rrecp;
98	u_char answer[PACKETSZ];
99	u_char *packet;
100	struct zonegrp *zptr, tgrp;
101	LIST(struct zonegrp) zgrps;
102	int nzones = 0, nscount = 0, n;
103	union res_sockaddr_union nsaddrs[MAXNS];
104
105	packet = malloc(NS_MAXMSG);
106	if (packet == NULL) {
107		DPRINTF(("malloc failed"));
108		return (0);
109	}
110	/* Thread all of the updates onto a list of groups. */
111	INIT_LIST(zgrps);
112	memset(&tgrp, 0, sizeof (tgrp));
113	for (rrecp = rrecp_in; rrecp;
114	     rrecp = LINKED(rrecp, r_link) ? NEXT(rrecp, r_link) : NULL) {
115		int nscnt;
116		/* Find the origin for it if there is one. */
117		tgrp.z_class = rrecp->r_class;
118		nscnt = res_findzonecut2(statp, rrecp->r_dname, tgrp.z_class,
119					 RES_EXHAUSTIVE, tgrp.z_origin,
120					 sizeof tgrp.z_origin,
121					 tgrp.z_nsaddrs, MAXNS);
122		if (nscnt <= 0) {
123			DPRINTF(("res_findzonecut failed (%d)", nscnt));
124			goto done;
125		}
126		tgrp.z_nscount = nscnt;
127		/* Find the group for it if there is one. */
128		for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link))
129			if (ns_samename(tgrp.z_origin, zptr->z_origin) == 1 &&
130			    tgrp.z_class == zptr->z_class)
131				break;
132		/* Make a group for it if there isn't one. */
133		if (zptr == NULL) {
134			zptr = malloc(sizeof *zptr);
135			if (zptr == NULL) {
136				DPRINTF(("malloc failed"));
137				goto done;
138			}
139			*zptr = tgrp;
140			zptr->z_flags = 0;
141			INIT_LINK(zptr, z_link);
142			INIT_LIST(zptr->z_rrlist);
143			APPEND(zgrps, zptr, z_link);
144		}
145		/* Thread this rrecp onto the right group. */
146		APPEND(zptr->z_rrlist, rrecp, r_glink);
147	}
148
149	for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link)) {
150		/* Construct zone section and prepend it. */
151		rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin,
152				     zptr->z_class, ns_t_soa, 0);
153		if (rrecp == NULL) {
154			DPRINTF(("res_mkupdrec failed"));
155			goto done;
156		}
157		PREPEND(zptr->z_rrlist, rrecp, r_glink);
158		zptr->z_flags |= ZG_F_ZONESECTADDED;
159
160		/* Marshall the update message. */
161		n = res_nmkupdate(statp, HEAD(zptr->z_rrlist),
162				  packet, NS_MAXMSG);
163		DPRINTF(("res_mkupdate -> %d", n));
164		if (n < 0)
165			goto done;
166
167		/* Temporarily replace the resolver's nameserver set. */
168		nscount = res_getservers(statp, nsaddrs, MAXNS);
169		res_setservers(statp, zptr->z_nsaddrs, zptr->z_nscount);
170
171		/* Send the update and remember the result. */
172		if (key != NULL) {
173#ifdef _LIBC
174			DPRINTF(("TSIG is not supported\n"));
175			RES_SET_H_ERRNO(statp, NO_RECOVERY);
176			goto done;
177#else
178			n = res_nsendsigned(statp, packet, n, key,
179					    answer, sizeof answer);
180#endif
181		} else
182			n = res_nsend(statp, packet, n, answer, sizeof answer);
183		if (n < 0) {
184			DPRINTF(("res_nsend: send error, n=%d (%s)\n",
185				 n, strerror(errno)));
186			goto done;
187		}
188		if (((HEADER *)answer)->rcode == NOERROR)
189			nzones++;
190
191		/* Restore resolver's nameserver set. */
192		res_setservers(statp, nsaddrs, nscount);
193		nscount = 0;
194	}
195 done:
196	while (!EMPTY(zgrps)) {
197		zptr = HEAD(zgrps);
198		if ((zptr->z_flags & ZG_F_ZONESECTADDED) != 0)
199			res_freeupdrec(HEAD(zptr->z_rrlist));
200		UNLINK(zgrps, zptr, z_link);
201		free(zptr);
202	}
203	if (nscount != 0)
204		res_setservers(statp, nsaddrs, nscount);
205
206	free(packet);
207	return (nzones);
208}
209
210/* Private. */
211
212static void
213res_dprintf(const char *fmt, ...) {
214	va_list ap;
215
216	va_start(ap, fmt);
217	fputs(";; res_nupdate: ", stderr);
218	vfprintf(stderr, fmt, ap);
219	fputc('\n', stderr);
220	va_end(ap);
221}
222