lwresd.c

bind 9.3结合mysql数据库

/*
 * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2000-2003  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: lwresd.c,v 1.37.2.2.2.5 2004/03/08 04:04:19 marka Exp $ */

/*
 * Main program for the Lightweight Resolver Daemon.
 *
 * To paraphrase the old saying about X11, "It's not a lightweight deamon
 * for resolvers, it's a deamon for lightweight resolvers".
 */

#include <config.h>

#include <stdlib.h>
#include <string.h>

#include <isc/list.h>
#include <isc/magic.h>
#include <isc/mem.h>
#include <isc/once.h>
#include <isc/print.h>
#include <isc/socket.h>
#include <isc/task.h>
#include <isc/util.h>

#include <isccfg/namedconf.h>

#include <dns/log.h>
#include <dns/result.h>
#include <dns/view.h>

#include <named/config.h>
#include <named/globals.h>
#include <named/log.h>
#include <named/lwaddr.h>
#include <named/lwresd.h>
#include <named/lwdclient.h>
#include <named/lwsearch.h>
#include <named/server.h>

#define LWRESD_MAGIC		ISC_MAGIC('L', 'W', 'R', 'D')
#define VALID_LWRESD(l)		ISC_MAGIC_VALID(l, LWRESD_MAGIC)

#define LWRESLISTENER_MAGIC	ISC_MAGIC('L', 'W', 'R', 'L')
#define VALID_LWRESLISTENER(l)	ISC_MAGIC_VALID(l, LWRESLISTENER_MAGIC)

/*
 * The total number of clients we can handle will be NTASKS * NRECVS.
 */
#define NTASKS		2	/* tasks to create to handle lwres queries */
#define NRECVS		2	/* max clients per task */

typedef ISC_LIST(ns_lwreslistener_t) ns_lwreslistenerlist_t;

static ns_lwreslistenerlist_t listeners;
static isc_mutex_t listeners_lock;
static isc_once_t once = ISC_ONCE_INIT;


static void
initialize_mutex(void) {
	RUNTIME_CHECK(isc_mutex_init(&listeners_lock) == ISC_R_SUCCESS);
}


/*
 * Wrappers around our memory management stuff, for the lwres functions.
 */
void *
ns__lwresd_memalloc(void *arg, size_t size) {
	return (isc_mem_get(arg, size));
}

void
ns__lwresd_memfree(void *arg, void *mem, size_t size) {
	isc_mem_put(arg, mem, size);
}


#define CHECK(op)						\
	do { result = (op);					\
		if (result != ISC_R_SUCCESS) goto cleanup;	\
	} while (0)

static isc_result_t
buffer_putstr(isc_buffer_t *b, const char *s) {
	unsigned int len = strlen(s);
	if (isc_buffer_availablelength(b) <= len)
		return (ISC_R_NOSPACE);
	isc_buffer_putmem(b, (const unsigned char *)s, len);
	return (ISC_R_SUCCESS);
}

/*
 * Convert a resolv.conf file into a config structure.
 */
isc_result_t
ns_lwresd_parseeresolvconf(isc_mem_t *mctx, cfg_parser_t *pctx,
			   cfg_obj_t **configp)
{
	char text[4096];
	char str[16];
	isc_buffer_t b;
	lwres_context_t *lwctx = NULL;
	lwres_conf_t *lwc = NULL;
	isc_sockaddr_t sa;
	isc_netaddr_t na;
	int i;
	isc_result_t result;
	lwres_result_t lwresult;

	lwctx = NULL;
	lwresult = lwres_context_create(&lwctx, mctx, ns__lwresd_memalloc,
					ns__lwresd_memfree,
					LWRES_CONTEXT_SERVERMODE);
	if (lwresult != LWRES_R_SUCCESS) {
		result = ISC_R_NOMEMORY;
		goto cleanup;
	}

	lwresult = lwres_conf_parse(lwctx, lwresd_g_resolvconffile);
	if (lwresult != LWRES_R_SUCCESS) {
		result = DNS_R_SYNTAX;
		goto cleanup;
	}

	lwc = lwres_conf_get(lwctx);
	INSIST(lwc != NULL);

	isc_buffer_init(&b, text, sizeof(text));

	CHECK(buffer_putstr(&b, "options {\n"));

	/*
	 * Build the list of forwarders.
	 */
	if (lwc->nsnext > 0) {
		CHECK(buffer_putstr(&b, "\tforwarders {\n"));

		for (i = 0; i < lwc->nsnext; i++) {
			CHECK(lwaddr_sockaddr_fromlwresaddr(
							&sa,
							&lwc->nameservers[i],
							ns_g_port));
			isc_netaddr_fromsockaddr(&na, &sa);
			CHECK(buffer_putstr(&b, "\t\t"));
			CHECK(isc_netaddr_totext(&na, &b));
			CHECK(buffer_putstr(&b, ";\n"));
		}
		CHECK(buffer_putstr(&b, "\t};\n"));
	}

	/*
	 * Build the sortlist
	 */
	if (lwc->sortlistnxt > 0) {
		CHECK(buffer_putstr(&b, "\tsortlist {\n"));
		CHECK(buffer_putstr(&b, "\t\t{\n"));
		CHECK(buffer_putstr(&b, "\t\t\tany;\n"));
		CHECK(buffer_putstr(&b, "\t\t\t{\n"));
		for (i = 0; i < lwc->sortlistnxt; i++) {
			lwres_addr_t *lwaddr = &lwc->sortlist[i].addr;
			lwres_addr_t *lwmask = &lwc->sortlist[i].mask;
			unsigned int mask;

			CHECK(lwaddr_sockaddr_fromlwresaddr(&sa, lwmask, 0));
			isc_netaddr_fromsockaddr(&na, &sa);
			result = isc_netaddr_masktoprefixlen(&na, &mask);
			if (result != ISC_R_SUCCESS) {
				char addrtext[ISC_NETADDR_FORMATSIZE];
				isc_netaddr_format(&na, addrtext,
						   sizeof(addrtext));
				isc_log_write(ns_g_lctx,
					      NS_LOGCATEGORY_GENERAL,
					      NS_LOGMODULE_LWRESD,
					      ISC_LOG_ERROR,
					      "processing sortlist: '%s' is "
					      "not a valid netmask",
					      addrtext);
				goto cleanup;
			}

			CHECK(lwaddr_sockaddr_fromlwresaddr(&sa, lwaddr, 0));
			isc_netaddr_fromsockaddr(&na, &sa);

			CHECK(buffer_putstr(&b, "\t\t\t\t"));
			CHECK(isc_netaddr_totext(&na, &b));
			snprintf(str, sizeof(str), "%u", mask);
			CHECK(buffer_putstr(&b, "/"));
			CHECK(buffer_putstr(&b, str));
			CHECK(buffer_putstr(&b, ";\n"));
		}
		CHECK(buffer_putstr(&b, "\t\t\t};\n"));
		CHECK(buffer_putstr(&b, "\t\t};\n"));
		CHECK(buffer_putstr(&b, "\t};\n"));
	}

	CHECK(buffer_putstr(&b, "};\n\n"));

	CHECK(buffer_putstr(&b, "lwres {\n"));

	/*
	 * Build the search path
	 */
	if (lwc->searchnxt > 0) {
		if (lwc->searchnxt > 0) {
			CHECK(buffer_putstr(&b, "\tsearch {\n"));
			for (i = 0; i < lwc->searchnxt; i++) {
				CHECK(buffer_putstr(&b, "\t\t\""));
				CHECK(buffer_putstr(&b, lwc->search[i]));
			        CHECK(buffer_putstr(&b, "\";\n"));
			}
			CHECK(buffer_putstr(&b, "\t};\n"));
		}
	}

	/*
	 * Build the ndots line
	 */
	if (lwc->ndots != 1) {
		CHECK(buffer_putstr(&b, "\tndots "));
		snprintf(str, sizeof(str), "%u", lwc->ndots);
		CHECK(buffer_putstr(&b, str));
		CHECK(buffer_putstr(&b, ";\n"));
	}

	/*
	 * Build the listen-on line
	 */
	if (lwc->lwnext > 0) {
		CHECK(buffer_putstr(&b, "\tlisten-on {\n"));

		for (i = 0; i < lwc->lwnext; i++) {
			CHECK(lwaddr_sockaddr_fromlwresaddr(&sa,
							    &lwc->lwservers[i],
							    0));
			isc_netaddr_fromsockaddr(&na, &sa);
			CHECK(buffer_putstr(&b, "\t\t"));
			CHECK(isc_netaddr_totext(&na, &b));
			CHECK(buffer_putstr(&b, ";\n"));
		}
		CHECK(buffer_putstr(&b, "\t};\n"));
	}

	CHECK(buffer_putstr(&b, "};\n"));

#if 0
	printf("%.*s\n",
	       (int)isc_buffer_usedlength(&b),
	       (char *)isc_buffer_base(&b));
#endif

	lwres_conf_clear(lwctx);
	lwres_context_destroy(&lwctx);

	return (cfg_parse_buffer(pctx, &b, &cfg_type_namedconf, configp));

 cleanup:

	if (lwctx != NULL) {
		lwres_conf_clear(lwctx);
		lwres_context_destroy(&lwctx);
	}

	return (result);
}


/*
 * Handle lwresd manager objects
 */
isc_result_t
ns_lwdmanager_create(isc_mem_t *mctx, cfg_obj_t *lwres,
		     ns_lwresd_t **lwresdp)
{
	ns_lwresd_t *lwresd;
	const char *vname;
	dns_rdataclass_t vclass;
	cfg_obj_t *obj, *viewobj, *searchobj;
	cfg_listelt_t *element;
	isc_result_t result;

	INSIST(lwresdp != NULL && *lwresdp == NULL);

	lwresd = isc_mem_get(mctx, sizeof(ns_lwresd_t));
	if (lwresd == NULL)
		return (ISC_R_NOMEMORY);

	lwresd->mctx = NULL;
	isc_mem_attach(mctx, &lwresd->mctx);
	lwresd->view = NULL;
	lwresd->search = NULL;
	lwresd->refs = 1;

	obj = NULL;
	(void)cfg_map_get(lwres, "ndots", &obj);
	if (obj != NULL)
		lwresd->ndots = cfg_obj_asuint32(obj);
	else
		lwresd->ndots = 1;

	RUNTIME_CHECK(isc_mutex_init(&lwresd->lock) == ISC_R_SUCCESS);

	lwresd->shutting_down = ISC_FALSE;

	viewobj = NULL;
	(void)cfg_map_get(lwres, "view", &viewobj);
	if (viewobj != NULL) {
		vname = cfg_obj_asstring(cfg_tuple_get(viewobj, "name"));
		obj = cfg_tuple_get(viewobj, "class");
		result = ns_config_getclass(obj, dns_rdataclass_in, &vclass);
		if (result != ISC_R_SUCCESS)
			goto fail;
	} else {
		vname = "_default";
		vclass = dns_rdataclass_in;
	}

	result = dns_viewlist_find(&ns_g_server->viewlist, vname, vclass,
				   &lwresd->view);
	if (result != ISC_R_SUCCESS) {
		isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
			      NS_LOGMODULE_LWRESD, ISC_LOG_WARNING,
			      "couldn't find view %s", vname);
		goto fail;
	}

	searchobj = NULL;
	(void)cfg_map_get(lwres, "search", &searchobj);
	if (searchobj != NULL) {
		lwresd->search = NULL;
		result = ns_lwsearchlist_create(lwresd->mctx,
						&lwresd->search);
		if (result != ISC_R_SUCCESS) {
			isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
				      NS_LOGMODULE_LWRESD, ISC_LOG_WARNING,
				      "couldn't create searchlist");
			goto fail;
		}
		for (element = cfg_list_first(searchobj);
		     element != NULL;
		     element = cfg_list_next(element))
		{
			cfg_obj_t *search;
			char *searchstr;
			isc_buffer_t namebuf;
			dns_fixedname_t fname;
			dns_name_t *name;

			search = cfg_listelt_value(element);
			searchstr = cfg_obj_asstring(search);

			dns_fixedname_init(&fname);
			name = dns_fixedname_name(&fname);
			isc_buffer_init(&namebuf, searchstr,
					strlen(searchstr));
			isc_buffer_add(&namebuf, strlen(searchstr));
			result = dns_name_fromtext(name, &namebuf,
						   dns_rootname, ISC_FALSE,
						   NULL);
			if (result != ISC_R_SUCCESS) {
				isc_log_write(ns_g_lctx,
					      NS_LOGCATEGORY_GENERAL,
					      NS_LOGMODULE_LWRESD,
					      ISC_LOG_WARNING,
					      "invalid name %s in searchlist",
					      searchstr);
				continue;
			}

			result = ns_lwsearchlist_append(lwresd->search, name);
			if (result != ISC_R_SUCCESS) {
				isc_log_write(ns_g_lctx,
					      NS_LOGCATEGORY_GENERAL,
					      NS_LOGMODULE_LWRESD,
					      ISC_LOG_WARNING,
					      "couldn't update searchlist");
				goto fail;
			}
		}
	}

	lwresd->magic = LWRESD_MAGIC;

	*lwresdp = lwresd;
	return (ISC_R_SUCCESS);

 fail:
	if (lwresd->view != NULL)
		dns_view_detach(&lwresd->view);
	if (lwresd->search != NULL)
		ns_lwsearchlist_detach(&lwresd->search);
	if (lwresd->mctx != NULL)
		isc_mem_detach(&lwresd->mctx);
	return (result);
}

void
ns_lwdmanager_attach(ns_lwresd_t *source, ns_lwresd_t **targetp) {
	INSIST(VALID_LWRESD(source));
	INSIST(targetp != NULL && *targetp == NULL);

	LOCK(&source->lock);
	source->refs++;
	UNLOCK(&source->lock);

	*targetp = source;
}

void
ns_lwdmanager_detach(ns_lwresd_t **lwresdp) {
	ns_lwresd_t *lwresd;
	isc_mem_t *mctx;
	isc_boolean_t done = ISC_FALSE;

	INSIST(lwresdp != NULL && *lwresdp != NULL);