xref: /netbsd-src/external/mpl/bind/dist/lib/ns/notify.c (revision bcda20f65a8566e103791ec395f7f499ef322704)
1 /*	$NetBSD: notify.c,v 1.8 2025/01/26 16:25:45 christos Exp $	*/
2 
3 /*
4  * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
5  *
6  * SPDX-License-Identifier: MPL-2.0
7  *
8  * This Source Code Form is subject to the terms of the Mozilla Public
9  * License, v. 2.0. If a copy of the MPL was not distributed with this
10  * file, you can obtain one at https://mozilla.org/MPL/2.0/.
11  *
12  * See the COPYRIGHT file distributed with this work for additional
13  * information regarding copyright ownership.
14  */
15 
16 #include <isc/log.h>
17 #include <isc/result.h>
18 
19 #include <dns/message.h>
20 #include <dns/rdataset.h>
21 #include <dns/result.h>
22 #include <dns/tsig.h>
23 #include <dns/view.h>
24 #include <dns/zone.h>
25 #include <dns/zt.h>
26 
27 #include <ns/log.h>
28 #include <ns/notify.h>
29 #include <ns/types.h>
30 
31 /*! \file
32  * \brief
33  * This module implements notify as in RFC1996.
34  */
35 
36 static void
37 notify_log(ns_client_t *client, int level, const char *fmt, ...) {
38 	va_list ap;
39 
40 	va_start(ap, fmt);
41 	ns_client_logv(client, DNS_LOGCATEGORY_NOTIFY, NS_LOGMODULE_NOTIFY,
42 		       level, fmt, ap);
43 	va_end(ap);
44 }
45 
46 static void
47 respond(ns_client_t *client, isc_result_t result) {
48 	dns_rcode_t rcode;
49 	dns_message_t *message;
50 	isc_result_t msg_result;
51 
52 	message = client->message;
53 	rcode = dns_result_torcode(result);
54 
55 	msg_result = dns_message_reply(message, true);
56 	if (msg_result != ISC_R_SUCCESS) {
57 		msg_result = dns_message_reply(message, false);
58 	}
59 	if (msg_result != ISC_R_SUCCESS) {
60 		ns_client_drop(client, msg_result);
61 		isc_nmhandle_detach(&client->reqhandle);
62 		return;
63 	}
64 	message->rcode = rcode;
65 	if (rcode == dns_rcode_noerror) {
66 		message->flags |= DNS_MESSAGEFLAG_AA;
67 	} else {
68 		message->flags &= ~DNS_MESSAGEFLAG_AA;
69 	}
70 
71 	ns_client_send(client);
72 	isc_nmhandle_detach(&client->reqhandle);
73 }
74 
75 void
76 ns_notify_start(ns_client_t *client, isc_nmhandle_t *handle) {
77 	dns_message_t *request = client->message;
78 	isc_result_t result;
79 	dns_name_t *zonename;
80 	dns_rdataset_t *zone_rdataset;
81 	dns_zone_t *zone = NULL;
82 	char namebuf[DNS_NAME_FORMATSIZE];
83 	char tsigbuf[DNS_NAME_FORMATSIZE * 2 + sizeof(": TSIG '' ()")];
84 	dns_tsigkey_t *tsigkey;
85 
86 	/*
87 	 * Attach to the request handle
88 	 */
89 	isc_nmhandle_attach(handle, &client->reqhandle);
90 
91 	/*
92 	 * Interpret the question section.
93 	 */
94 	result = dns_message_firstname(request, DNS_SECTION_QUESTION);
95 	if (result != ISC_R_SUCCESS) {
96 		notify_log(client, ISC_LOG_NOTICE,
97 			   "notify question section empty");
98 		result = DNS_R_FORMERR;
99 		goto done;
100 	}
101 
102 	/*
103 	 * The question section must contain exactly one question.
104 	 */
105 	zonename = NULL;
106 	dns_message_currentname(request, DNS_SECTION_QUESTION, &zonename);
107 	zone_rdataset = ISC_LIST_HEAD(zonename->list);
108 	if (ISC_LIST_NEXT(zone_rdataset, link) != NULL) {
109 		notify_log(client, ISC_LOG_NOTICE,
110 			   "notify question section contains multiple RRs");
111 		result = DNS_R_FORMERR;
112 		goto done;
113 	}
114 
115 	/* The zone section must have exactly one name. */
116 	result = dns_message_nextname(request, DNS_SECTION_ZONE);
117 	if (result != ISC_R_NOMORE) {
118 		notify_log(client, ISC_LOG_NOTICE,
119 			   "notify question section contains multiple RRs");
120 		result = DNS_R_FORMERR;
121 		goto done;
122 	}
123 
124 	/* The one rdataset must be an SOA. */
125 	if (zone_rdataset->type != dns_rdatatype_soa) {
126 		notify_log(client, ISC_LOG_NOTICE,
127 			   "notify question section contains no SOA");
128 		result = DNS_R_FORMERR;
129 		goto done;
130 	}
131 
132 	tsigkey = dns_message_gettsigkey(request);
133 	if (tsigkey != NULL) {
134 		dns_name_format(tsigkey->name, namebuf, sizeof(namebuf));
135 
136 		if (tsigkey->generated) {
137 			char cnamebuf[DNS_NAME_FORMATSIZE];
138 			dns_name_format(tsigkey->creator, cnamebuf,
139 					sizeof(cnamebuf));
140 			snprintf(tsigbuf, sizeof(tsigbuf), ": TSIG '%s' (%s)",
141 				 namebuf, cnamebuf);
142 		} else {
143 			snprintf(tsigbuf, sizeof(tsigbuf), ": TSIG '%s'",
144 				 namebuf);
145 		}
146 	} else {
147 		tsigbuf[0] = '\0';
148 	}
149 
150 	dns_name_format(zonename, namebuf, sizeof(namebuf));
151 	result = dns_view_findzone(client->view, zonename, DNS_ZTFIND_EXACT,
152 				   &zone);
153 	if (result == ISC_R_SUCCESS) {
154 		dns_zonetype_t zonetype = dns_zone_gettype(zone);
155 
156 		if ((zonetype == dns_zone_primary) ||
157 		    (zonetype == dns_zone_secondary) ||
158 		    (zonetype == dns_zone_mirror) ||
159 		    (zonetype == dns_zone_stub))
160 		{
161 			isc_sockaddr_t *from = ns_client_getsockaddr(client);
162 			isc_sockaddr_t *to = ns_client_getdestaddr(client);
163 			notify_log(client, ISC_LOG_INFO,
164 				   "received notify for zone '%s'%s", namebuf,
165 				   tsigbuf);
166 			result = dns_zone_notifyreceive(zone, from, to,
167 							request);
168 			goto done;
169 		}
170 	}
171 
172 	result = DNS_R_NOTAUTH;
173 	notify_log(client, ISC_LOG_NOTICE,
174 		   "received notify for zone '%s'%s: %s", namebuf, tsigbuf,
175 		   isc_result_totext(result));
176 
177 done:
178 	if (zone != NULL) {
179 		dns_zone_detach(&zone);
180 	}
181 	respond(client, result);
182 }
183