1 #if !defined(lint) && !defined(SABER)
2 static const char rcsid[] = "$Id: res_update.c,v 1.13 2005/04/27 04:56:43 sra Exp $";
3 #endif /* not lint */
4 
5 /*
6  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
7  * Copyright (c) 1996-1999 by Internet Software Consortium.
8  *
9  * Permission to use, copy, modify, and distribute this software for any
10  * purpose with or without fee is hereby granted, provided that the above
11  * copyright notice and this permission notice appear in all copies.
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
14  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
16  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
19  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20  */
21 
22 /*! \file
23  * \brief
24  * Based on the Dynamic DNS reference implementation by Viraj Bais
25  * <viraj_bais@ccm.fm.intel.com>
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD: stable/9/lib/libc/resolv/res_update.c 270851 2014-08-30 17:56:58Z ume $");
30 
31 #include "port_before.h"
32 
33 #include <sys/param.h>
34 #include <sys/socket.h>
35 #include <sys/time.h>
36 
37 #include <netinet/in.h>
38 #include <arpa/inet.h>
39 #include <arpa/nameser.h>
40 
41 #include <errno.h>
42 #include <limits.h>
43 #include <netdb.h>
44 #include <res_update.h>
45 #include <stdarg.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 
50 #include <isc/list.h>
51 #include <resolv.h>
52 
53 #include "port_after.h"
54 #include "res_private.h"
55 
56 /*%
57  * Separate a linked list of records into groups so that all records
58  * in a group will belong to a single zone on the nameserver.
59  * Create a dynamic update packet for each zone and send it to the
60  * nameservers for that zone, and await answer.
61  * Abort if error occurs in updating any zone.
62  * Return the number of zones updated on success, < 0 on error.
63  *
64  * On error, caller must deal with the unsynchronized zones
65  * eg. an A record might have been successfully added to the forward
66  * zone but the corresponding PTR record would be missing if error
67  * was encountered while updating the reverse zone.
68  */
69 
70 struct zonegrp {
71 	char			z_origin[MAXDNAME];
72 	ns_class		z_class;
73 	union res_sockaddr_union z_nsaddrs[MAXNS];
74 	int			z_nscount;
75 	int			z_flags;
76 	LIST(ns_updrec)		z_rrlist;
77 	LINK(struct zonegrp)	z_link;
78 };
79 
80 #define ZG_F_ZONESECTADDED	0x0001
81 
82 /* Forward. */
83 
84 static void	res_dprintf(const char *, ...) ISC_FORMAT_PRINTF(1, 2);
85 
86 /* Macros. */
87 
88 #define DPRINTF(x) do {\
89 		int save_errno = errno; \
90 		if ((statp->options & RES_DEBUG) != 0U) res_dprintf x; \
91 		errno = save_errno; \
92 	} while (0)
93 
94 /* Public. */
95 
96 int
res_nupdate(res_state statp,ns_updrec * rrecp_in,ns_tsig_key * key)97 res_nupdate(res_state statp, ns_updrec *rrecp_in, ns_tsig_key *key) {
98 	ns_updrec *rrecp;
99 	u_char answer[PACKETSZ];
100 	u_char *packet;
101 	struct zonegrp *zptr, tgrp;
102 	LIST(struct zonegrp) zgrps;
103 	int nzones = 0, nscount = 0, n;
104 	union res_sockaddr_union nsaddrs[MAXNS];
105 
106 	packet = malloc(NS_MAXMSG);
107 	if (packet == NULL) {
108 		DPRINTF(("malloc failed"));
109 		return (0);
110 	}
111 	/* Thread all of the updates onto a list of groups. */
112 	INIT_LIST(zgrps);
113 	memset(&tgrp, 0, sizeof (tgrp));
114 	for (rrecp = rrecp_in; rrecp;
115 	     rrecp = LINKED(rrecp, r_link) ? NEXT(rrecp, r_link) : NULL) {
116 		int nscnt;
117 		/* Find the origin for it if there is one. */
118 		tgrp.z_class = rrecp->r_class;
119 		nscnt = res_findzonecut2(statp, rrecp->r_dname, tgrp.z_class,
120 					 RES_EXHAUSTIVE, tgrp.z_origin,
121 					 sizeof tgrp.z_origin,
122 					 tgrp.z_nsaddrs, MAXNS);
123 		if (nscnt <= 0) {
124 			DPRINTF(("res_findzonecut failed (%d)", nscnt));
125 			goto done;
126 		}
127 		tgrp.z_nscount = nscnt;
128 		/* Find the group for it if there is one. */
129 		for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link))
130 			if (ns_samename(tgrp.z_origin, zptr->z_origin) == 1 &&
131 			    tgrp.z_class == zptr->z_class)
132 				break;
133 		/* Make a group for it if there isn't one. */
134 		if (zptr == NULL) {
135 			zptr = malloc(sizeof *zptr);
136 			if (zptr == NULL) {
137 				DPRINTF(("malloc failed"));
138 				goto done;
139 			}
140 			*zptr = tgrp;
141 			zptr->z_flags = 0;
142 			INIT_LINK(zptr, z_link);
143 			INIT_LIST(zptr->z_rrlist);
144 			APPEND(zgrps, zptr, z_link);
145 		}
146 		/* Thread this rrecp onto the right group. */
147 		APPEND(zptr->z_rrlist, rrecp, r_glink);
148 	}
149 
150 	for (zptr = HEAD(zgrps); zptr != NULL; zptr = NEXT(zptr, z_link)) {
151 		/* Construct zone section and prepend it. */
152 		rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin,
153 				     zptr->z_class, ns_t_soa, 0);
154 		if (rrecp == NULL) {
155 			DPRINTF(("res_mkupdrec failed"));
156 			goto done;
157 		}
158 		PREPEND(zptr->z_rrlist, rrecp, r_glink);
159 		zptr->z_flags |= ZG_F_ZONESECTADDED;
160 
161 		/* Marshall the update message. */
162 		n = res_nmkupdate(statp, HEAD(zptr->z_rrlist),
163 				  packet, NS_MAXMSG);
164 		DPRINTF(("res_mkupdate -> %d", n));
165 		if (n < 0)
166 			goto done;
167 
168 		/* Temporarily replace the resolver's nameserver set. */
169 		nscount = res_getservers(statp, nsaddrs, MAXNS);
170 		res_setservers(statp, zptr->z_nsaddrs, zptr->z_nscount);
171 
172 		/* Send the update and remember the result. */
173 		if (key != NULL) {
174 #ifdef _LIBC
175 			DPRINTF(("TSIG is not supported\n"));
176 			RES_SET_H_ERRNO(statp, NO_RECOVERY);
177 			goto done;
178 #else
179 			n = res_nsendsigned(statp, packet, n, key,
180 					    answer, sizeof answer);
181 #endif
182 		} else
183 			n = res_nsend(statp, packet, n, answer, sizeof answer);
184 		if (n < 0) {
185 			DPRINTF(("res_nsend: send error, n=%d (%s)\n",
186 				 n, strerror(errno)));
187 			goto done;
188 		}
189 		if (((HEADER *)answer)->rcode == NOERROR)
190 			nzones++;
191 
192 		/* Restore resolver's nameserver set. */
193 		res_setservers(statp, nsaddrs, nscount);
194 		nscount = 0;
195 	}
196  done:
197 	while (!EMPTY(zgrps)) {
198 		zptr = HEAD(zgrps);
199 		if ((zptr->z_flags & ZG_F_ZONESECTADDED) != 0)
200 			res_freeupdrec(HEAD(zptr->z_rrlist));
201 		UNLINK(zgrps, zptr, z_link);
202 		free(zptr);
203 	}
204 	if (nscount != 0)
205 		res_setservers(statp, nsaddrs, nscount);
206 
207 	free(packet);
208 	return (nzones);
209 }
210 
211 /* Private. */
212 
213 static void
res_dprintf(const char * fmt,...)214 res_dprintf(const char *fmt, ...) {
215 	va_list ap;
216 
217 	va_start(ap, fmt);
218 	fputs(";; res_nupdate: ", stderr);
219 	vfprintf(stderr, fmt, ap);
220 	fputc('\n', stderr);
221 	va_end(ap);
222 }
223