notify.c

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00001 /*
00002  * Copyright (C) 2004-2007  Internet Systems Consortium, Inc. ("ISC")
00003  * Copyright (C) 1999-2003  Internet Software Consortium.
00004  *
00005  * Permission to use, copy, modify, and/or distribute this software for any
00006  * purpose with or without fee is hereby granted, provided that the above
00007  * copyright notice and this permission notice appear in all copies.
00008  *
00009  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
00010  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
00011  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
00012  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
00013  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
00014  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
00015  * PERFORMANCE OF THIS SOFTWARE.
00016  */
00017 
00018 /* $Id: notify.c,v 1.37 2007/06/19 23:46:59 tbox Exp $ */
00019 
00020 #include <config.h>
00021 
00022 #include <isc/log.h>
00023 #include <isc/print.h>
00024 
00025 #include <dns/message.h>
00026 #include <dns/rdataset.h>
00027 #include <dns/result.h>
00028 #include <dns/tsig.h>
00029 #include <dns/view.h>
00030 #include <dns/zone.h>
00031 #include <dns/zt.h>
00032 
00033 #include <named/log.h>
00034 #include <named/notify.h>
00035 
00036 /*! \file
00037  * \brief
00038  * This module implements notify as in RFC1996.
00039  */
00040 
00041 static void
00042 notify_log(ns_client_t *client, int level, const char *fmt, ...) {
00043         va_list ap;
00044 
00045         va_start(ap, fmt);
00046         ns_client_logv(client, DNS_LOGCATEGORY_NOTIFY, NS_LOGMODULE_NOTIFY,
00047                        level, fmt, ap);
00048         va_end(ap);
00049 }
00050 
00051 static void
00052 respond(ns_client_t *client, isc_result_t result) {
00053         dns_rcode_t rcode;
00054         dns_message_t *message;
00055         isc_result_t msg_result;
00056 
00057         message = client->message;
00058         rcode = dns_result_torcode(result);
00059 
00060         msg_result = dns_message_reply(message, ISC_TRUE);
00061         if (msg_result != ISC_R_SUCCESS)
00062                 msg_result = dns_message_reply(message, ISC_FALSE);
00063         if (msg_result != ISC_R_SUCCESS) {
00064                 ns_client_next(client, msg_result);
00065                 return;
00066         }
00067         message->rcode = rcode;
00068         if (rcode == dns_rcode_noerror)
00069                 message->flags |= DNS_MESSAGEFLAG_AA;
00070         else
00071                 message->flags &= ~DNS_MESSAGEFLAG_AA;
00072         ns_client_send(client);
00073 }
00074 
00075 void
00076 ns_notify_start(ns_client_t *client) {
00077         dns_message_t *request = client->message;
00078         isc_result_t result;
00079         dns_name_t *zonename;
00080         dns_rdataset_t *zone_rdataset;
00081         dns_zone_t *zone = NULL;
00082         char namebuf[DNS_NAME_FORMATSIZE];
00083         char tsigbuf[DNS_NAME_FORMATSIZE + sizeof(": TSIG ''")];
00084         dns_tsigkey_t *tsigkey;
00085 
00086         /*
00087          * Interpret the question section.
00088          */
00089         result = dns_message_firstname(request, DNS_SECTION_QUESTION);
00090         if (result != ISC_R_SUCCESS) {
00091                 notify_log(client, ISC_LOG_NOTICE,
00092                            "notify question section empty");
00093                 goto formerr;
00094         }
00095 
00096         /*
00097          * The question section must contain exactly one question.
00098          */
00099         zonename = NULL;
00100         dns_message_currentname(request, DNS_SECTION_QUESTION, &zonename);
00101         zone_rdataset = ISC_LIST_HEAD(zonename->list);
00102         if (ISC_LIST_NEXT(zone_rdataset, link) != NULL) {
00103                 notify_log(client, ISC_LOG_NOTICE,
00104                            "notify question section contains multiple RRs");
00105                 goto formerr;
00106         }
00107 
00108         /* The zone section must have exactly one name. */
00109         result = dns_message_nextname(request, DNS_SECTION_ZONE);
00110         if (result != ISC_R_NOMORE) {
00111                 notify_log(client, ISC_LOG_NOTICE,
00112                            "notify question section contains multiple RRs");
00113                 goto formerr;
00114         }
00115 
00116         /* The one rdataset must be an SOA. */
00117         if (zone_rdataset->type != dns_rdatatype_soa) {
00118                 notify_log(client, ISC_LOG_NOTICE,
00119                            "notify question section contains no SOA");
00120                 goto formerr;
00121         }
00122 
00123         tsigkey = dns_message_gettsigkey(request);
00124         if (tsigkey != NULL) {
00125                 dns_name_format(&tsigkey->name, namebuf, sizeof(namebuf));
00126 
00127                 if (tsigkey->generated) {
00128                         char cnamebuf[DNS_NAME_FORMATSIZE];
00129                         dns_name_format(tsigkey->creator, cnamebuf,
00130                                         sizeof(cnamebuf));
00131                         snprintf(tsigbuf, sizeof(tsigbuf), ": TSIG '%s' (%s)",
00132                                  namebuf, cnamebuf);
00133                 } else {
00134                         snprintf(tsigbuf, sizeof(tsigbuf), ": TSIG '%s'",
00135                                  namebuf);
00136                 }
00137         } else
00138                 tsigbuf[0] = '\0';
00139         dns_name_format(zonename, namebuf, sizeof(namebuf));
00140         result = dns_zt_find(client->view->zonetable, zonename, 0, NULL,
00141                              &zone);
00142         if (result != ISC_R_SUCCESS)
00143                 goto notauth;
00144 
00145         switch (dns_zone_gettype(zone)) {
00146         case dns_zone_master:
00147         case dns_zone_slave:
00148         case dns_zone_stub:     /* Allow dialup passive to work. */
00149                 notify_log(client, ISC_LOG_INFO,
00150                            "received notify for zone '%s'%s", namebuf, tsigbuf);
00151                 respond(client, dns_zone_notifyreceive(zone,
00152                         ns_client_getsockaddr(client), request));
00153                 break;
00154         default:
00155                 goto notauth;
00156         }
00157         dns_zone_detach(&zone);
00158         return;
00159 
00160  notauth:
00161         notify_log(client, ISC_LOG_NOTICE,
00162                    "received notify for zone '%s'%s: not authoritative",
00163                    namebuf, tsigbuf);
00164         result = DNS_R_NOTAUTH;
00165         goto failure;
00166 
00167  formerr:
00168         result = DNS_R_FORMERR;
00169 
00170  failure:
00171         if (zone != NULL)
00172                 dns_zone_detach(&zone);
00173         respond(client, result);
00174 }

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