dispatch.c

bind-3.2.

		goto kill_rpool;
	}

	isc_mempool_setname(mgr->epool, "dispmgr_epool");
	isc_mempool_setfreemax(mgr->epool, 1024);
	isc_mempool_associatelock(mgr->epool, &mgr->pool_lock);

	isc_mempool_setname(mgr->rpool, "dispmgr_rpool");
	isc_mempool_setfreemax(mgr->rpool, 1024);
	isc_mempool_associatelock(mgr->rpool, &mgr->pool_lock);

	isc_mempool_setname(mgr->dpool, "dispmgr_dpool");
	isc_mempool_setfreemax(mgr->dpool, 1024);
	isc_mempool_associatelock(mgr->dpool, &mgr->pool_lock);

	mgr->buffers = 0;
	mgr->buffersize = 0;
	mgr->maxbuffers = 0;
	mgr->bpool = NULL;
	mgr->entropy = NULL;
	mgr->qid = NULL;
	mgr->state = 0;
	ISC_LIST_INIT(mgr->list);
	mgr->magic = DNS_DISPATCHMGR_MAGIC;

	if (entropy != NULL)
		isc_entropy_attach(entropy, &mgr->entropy);

	*mgrp = mgr;
	return (ISC_R_SUCCESS);

 kill_rpool:
	isc_mempool_destroy(&mgr->rpool);
 kill_epool:
	isc_mempool_destroy(&mgr->epool);
 kill_pool_lock:
	DESTROYLOCK(&mgr->pool_lock);
 kill_buffer_lock:
	DESTROYLOCK(&mgr->buffer_lock);
 kill_lock:
	DESTROYLOCK(&mgr->lock);
 deallocate:
	isc_mem_put(mctx, mgr, sizeof(dns_dispatchmgr_t));
	isc_mem_detach(&mctx);

	return (result);
}

void
dns_dispatchmgr_setblackhole(dns_dispatchmgr_t *mgr, dns_acl_t *blackhole) {
	REQUIRE(VALID_DISPATCHMGR(mgr));
	if (mgr->blackhole != NULL)
		dns_acl_detach(&mgr->blackhole);
	dns_acl_attach(blackhole, &mgr->blackhole);
}

dns_acl_t *
dns_dispatchmgr_getblackhole(dns_dispatchmgr_t *mgr) {
	REQUIRE(VALID_DISPATCHMGR(mgr));
	return (mgr->blackhole);
}

static isc_result_t
dns_dispatchmgr_setudp(dns_dispatchmgr_t *mgr,
			unsigned int buffersize, unsigned int maxbuffers,
			unsigned int buckets, unsigned int increment)
{
	isc_result_t result;

	REQUIRE(VALID_DISPATCHMGR(mgr));
	REQUIRE(buffersize >= 512 && buffersize < (64 * 1024));
	REQUIRE(maxbuffers > 0);
	REQUIRE(buckets < 2097169);  /* next prime > 65536 * 32 */
	REQUIRE(increment > buckets);

	/*
	 * Keep some number of items around.  This should be a config
	 * option.  For now, keep 8, but later keep at least two even
	 * if the caller wants less.  This allows us to ensure certain
	 * things, like an event can be "freed" and the next allocation
	 * will always succeed.
	 *
	 * Note that if limits are placed on anything here, we use one
	 * event internally, so the actual limit should be "wanted + 1."
	 *
	 * XXXMLG
	 */

	if (maxbuffers < 8)
		maxbuffers = 8;

	LOCK(&mgr->buffer_lock);
	if (mgr->bpool != NULL) {
		isc_mempool_setmaxalloc(mgr->bpool, maxbuffers);
		mgr->maxbuffers = maxbuffers;
		UNLOCK(&mgr->buffer_lock);
		return (ISC_R_SUCCESS);
	}

	if (isc_mempool_create(mgr->mctx, buffersize,
			       &mgr->bpool) != ISC_R_SUCCESS) {
		return (ISC_R_NOMEMORY);
	}

	isc_mempool_setname(mgr->bpool, "dispmgr_bpool");
	isc_mempool_setmaxalloc(mgr->bpool, maxbuffers);
	isc_mempool_associatelock(mgr->bpool, &mgr->pool_lock);

	result = qid_allocate(mgr, buckets, increment, &mgr->qid);
	if (result != ISC_R_SUCCESS)
		goto cleanup;

	mgr->buffersize = buffersize;
	mgr->maxbuffers = maxbuffers;
	UNLOCK(&mgr->buffer_lock);
	return (ISC_R_SUCCESS);

 cleanup:
	isc_mempool_destroy(&mgr->bpool);
	UNLOCK(&mgr->buffer_lock);
	return (ISC_R_NOMEMORY);
}

void
dns_dispatchmgr_destroy(dns_dispatchmgr_t **mgrp) {
	dns_dispatchmgr_t *mgr;
	isc_boolean_t killit;

	REQUIRE(mgrp != NULL);
	REQUIRE(VALID_DISPATCHMGR(*mgrp));

	mgr = *mgrp;
	*mgrp = NULL;

	LOCK(&mgr->lock);
	mgr->state |= MGR_SHUTTINGDOWN;

	killit = destroy_mgr_ok(mgr);
	UNLOCK(&mgr->lock);

	mgr_log(mgr, LVL(90), "destroy: killit=%d", killit);

	if (killit)
		destroy_mgr(&mgr);
}


#define ATTRMATCH(_a1, _a2, _mask) (((_a1) & (_mask)) == ((_a2) & (_mask)))

static isc_boolean_t
local_addr_match(dns_dispatch_t *disp, isc_sockaddr_t *addr) {

	if (addr == NULL)
		return (ISC_TRUE);

	return (isc_sockaddr_equal(&disp->local, addr));
}

/*
 * Requires mgr be locked.
 *
 * No dispatcher can be locked by this thread when calling this function.
 *
 *
 * NOTE:
 *	If a matching dispatcher is found, it is locked after this function
 *	returns, and must be unlocked by the caller.
 */
static isc_result_t
dispatch_find(dns_dispatchmgr_t *mgr, isc_sockaddr_t *local,
	      unsigned int attributes, unsigned int mask,
	      dns_dispatch_t **dispp)
{
	dns_dispatch_t *disp;
	isc_result_t result;

	/*
	 * Make certain that we will not match a private dispatch.
	 */
	attributes &= ~DNS_DISPATCHATTR_PRIVATE;
	mask |= DNS_DISPATCHATTR_PRIVATE;

	disp = ISC_LIST_HEAD(mgr->list);
	while (disp != NULL) {
		LOCK(&disp->lock);
		if ((disp->shutting_down == 0)
		    && ATTRMATCH(disp->attributes, attributes, mask)
		    && local_addr_match(disp, local))
			break;
		UNLOCK(&disp->lock);
		disp = ISC_LIST_NEXT(disp, link);
	}

	if (disp == NULL) {
		result = ISC_R_NOTFOUND;
		goto out;
	}

	*dispp = disp;
	result = ISC_R_SUCCESS;
 out:

	return (result);
}

static isc_result_t
qid_allocate(dns_dispatchmgr_t *mgr, unsigned int buckets,
	     unsigned int increment, dns_qid_t **qidp)
{
	dns_qid_t *qid;
	unsigned int i;

	REQUIRE(VALID_DISPATCHMGR(mgr));
	REQUIRE(buckets < 2097169);  /* next prime > 65536 * 32 */
	REQUIRE(increment > buckets);
	REQUIRE(qidp != NULL && *qidp == NULL);

	qid = isc_mem_get(mgr->mctx, sizeof(*qid));
	if (qid == NULL)
		return (ISC_R_NOMEMORY);

	qid->qid_table = isc_mem_get(mgr->mctx,
				     buckets * sizeof(dns_displist_t));
	if (qid->qid_table == NULL) {
		isc_mem_put(mgr->mctx, qid, sizeof(*qid));
		return (ISC_R_NOMEMORY);
	}

	if (isc_mutex_init(&qid->lock) != ISC_R_SUCCESS) {
		UNEXPECTED_ERROR(__FILE__, __LINE__, "isc_mutex_init failed");
		isc_mem_put(mgr->mctx, qid->qid_table,
			    buckets * sizeof(dns_displist_t));
		isc_mem_put(mgr->mctx, qid, sizeof(*qid));
		return (ISC_R_UNEXPECTED);
	}

	for (i = 0 ; i < buckets ; i++)
		ISC_LIST_INIT(qid->qid_table[i]);

	qid->qid_nbuckets = buckets;
	qid->qid_increment = increment;
	qid->magic = QID_MAGIC;

	/*
	 * Initialize to a 32-bit LFSR.  Both of these are from Applied
	 * Cryptography.
	 *
	 * lfsr1:
	 *	x^32 + x^7 + x^5 + x^3 + x^2 + x + 1
	 *
	 * lfsr2:
	 *	x^32 + x^7 + x^6 + x^2 + 1
	 */
	isc_lfsr_init(&qid->qid_lfsr1, 0, 32, 0x80000057U,
		      0, reseed_lfsr, mgr);
	isc_lfsr_init(&qid->qid_lfsr2, 0, 32, 0x80000062U,
		      0, reseed_lfsr, mgr);
	*qidp = qid;
	return (ISC_R_SUCCESS);
}

static void
qid_destroy(isc_mem_t *mctx, dns_qid_t **qidp) {
	dns_qid_t *qid;

	REQUIRE(qidp != NULL);
	qid = *qidp;

	REQUIRE(VALID_QID(qid));

	*qidp = NULL;
	qid->magic = 0;
	isc_mem_put(mctx, qid->qid_table,
		    qid->qid_nbuckets * sizeof(dns_displist_t));
	DESTROYLOCK(&qid->lock);
	isc_mem_put(mctx, qid, sizeof(*qid));
}

/*
 * Allocate and set important limits.
 */
static isc_result_t
dispatch_allocate(dns_dispatchmgr_t *mgr, unsigned int maxrequests,
		  dns_dispatch_t **dispp)
{
	dns_dispatch_t *disp;
	isc_result_t res;

	REQUIRE(VALID_DISPATCHMGR(mgr));
	REQUIRE(dispp != NULL && *dispp == NULL);

	/*
	 * Set up the dispatcher, mostly.  Don't bother setting some of
	 * the options that are controlled by tcp vs. udp, etc.
	 */

	disp = isc_mempool_get(mgr->dpool);
	if (disp == NULL)
		return (ISC_R_NOMEMORY);

	disp->magic = 0;
	disp->mgr = mgr;
	disp->maxrequests = maxrequests;
	disp->attributes = 0;
	ISC_LINK_INIT(disp, link);
	disp->refcount = 1;
	disp->recv_pending = 0;
	memset(&disp->local, 0, sizeof disp->local);
	disp->shutting_down = 0;
	disp->shutdown_out = 0;
	disp->connected = 0;
	disp->tcpmsg_valid = 0;
	disp->shutdown_why = ISC_R_UNEXPECTED;
	disp->requests = 0;
	disp->tcpbuffers = 0;
	disp->qid = NULL;

	if (isc_mutex_init(&disp->lock) != ISC_R_SUCCESS) {
		res = ISC_R_UNEXPECTED;
		UNEXPECTED_ERROR(__FILE__, __LINE__, "isc_mutex_init failed");
		goto deallocate;
	}

	disp->failsafe_ev = allocate_event(disp);
	if (disp->failsafe_ev == NULL) {
		res = ISC_R_NOMEMORY;
		goto kill_lock;
	}

	disp->magic = DISPATCH_MAGIC;

	*dispp = disp;
	return (ISC_R_SUCCESS);

	/*
	 * error returns
	 */
 kill_lock:
	DESTROYLOCK(&disp->lock);
 deallocate:
	isc_mempool_put(mgr->dpool, disp);

	return (res);
}


/*
 * MUST be unlocked, and not used by anthing.
 */
static void
dispatch_free(dns_dispatch_t **dispp)
{
	dns_dispatch_t *disp;
	dns_dispatchmgr_t *mgr;

	REQUIRE(VALID_DISPATCH(*dispp));
	disp = *dispp;
	*dispp = NULL;

	mgr = disp->mgr;
	REQUIRE(VALID_DISPATCHMGR(mgr));

	if (disp->tcpmsg_valid) {
		dns_tcpmsg_invalidate(&disp->tcpmsg);
		disp->tcpmsg_valid = 0;
	}

	INSIST(disp->tcpbuffers == 0);
	INSIST(disp->requests == 0);
	INSIST(disp->recv_pending == 0);

	isc_mempool_put(mgr->epool, disp->failsafe_ev);
	disp->failsafe_ev = NULL;

	if (disp->qid != NULL)
		qid_destroy(mgr->mctx, &disp->qid);
	disp->mgr = NULL;
	DESTROYLOCK(&disp->lock);
	disp->magic = 0;
	isc_mempool_put(mgr->dpool, disp);
}

isc_result_t
dns_dispatch_createtcp(dns_dispatchmgr_t *mgr, isc_socket_t *sock,
		       isc_taskmgr_t *taskmgr, unsigned int buffersize,
		       unsigned int maxbuffers, unsigned int maxrequests,
		       unsigned int buckets, unsigned int increment,
		       unsigned int attributes, dns_dispatch_t **dispp)
{
	isc_result_t result;
	dns_dispatch_t *disp;

	UNUSED(maxbuffers);
	UNUSED(buffersize);

	REQUIRE(VALID_DISPATCHMGR(mgr));
	REQUIRE(isc_socket_gettype(sock) == isc_sockettype_tcp);
	REQUIRE((attributes & DNS_DISPATCHATTR_TCP) != 0);
	REQUIRE((attributes & DNS_DISPATCHATTR_UDP) == 0);

	attributes |= DNS_DISPATCHATTR_PRIVATE;  /* XXXMLG */

	LOCK(&mgr->lock);

	/*
	 * dispatch_allocate() checks mgr for us.
	 * qid_allocate() checks buckets and increment for us.
	 */
	disp = NULL;
	result = dispatch_allocate(mgr, maxrequests, &disp);
	if (result != ISC_R_SUCCESS) {
		UNLOCK(&mgr->lock);
		return (result);
	}

	result = qid_allocate(mgr, buckets, increment, &disp->qid);
	if (result != ISC_R_SUCCESS)
		goto deallocate_dispatch;

	disp->socktype = isc_sockettype_tcp;
	disp->socket = NULL;
	isc_socket_attach(sock, &disp->socket);

	disp->task = NULL;
	result = isc_task_create(taskmgr, 0, &disp->task);
	if (result != ISC_R_SUCCESS)
		goto kill_socket;

	disp->ctlevent = isc_event_allocate(mgr->mctx, disp,
					    DNS_EVENT_DISPATCHCONTROL,
					    destroy_disp, disp,
					    sizeof(isc_event_t));
	if (disp->ctlevent == NULL)
		goto kill_task;

	isc_task_setname(disp->task, "tcpdispatch", disp);

	dns_tcpmsg_init(mgr->mctx, disp->socket, &disp->tcpmsg);
	disp->tcpmsg_valid = 1;

	disp->attributes = attributes;

	/*
	 * Append it to the dispatcher list.
	 */
	ISC_LIST_APPEND(mgr->list, disp, link);
	UNLOCK(&mgr->lock);

	mgr_log(mgr, LVL(90), "created TCP dispatcher %p", disp);
	dispatch_log(disp, LVL(90), "created task %p", disp->task);

	*dispp = disp;

	return (ISC_R_SUCCESS);

	/*
	 * Error returns.
	 */
 kill_task:
	isc_task_detach(&disp->task);
 kill_socket:
	isc_socket_detach(&disp->socket);
 deallocate_dispatch:
	dispatch_free(&disp);

	UNLOCK(&mgr->lock);

	return (result);
}

isc_result_t
dns_dispatch_getudp(dns_dispatchmgr_t *mgr, isc_socketmgr_t *sockmgr,
		    isc_taskmgr_t *taskmgr, isc_sockaddr_t *localaddr,
		    unsigned int buffersize,
		    unsigned int maxbuffers, unsigned int maxrequests,
		    unsigned int buckets, unsigned int increment,
		    unsigned int attributes, unsigned int mask,
		    dns_dispatch_t **dispp)
{
	isc_result_t result;
	dns_dispatch_t *disp;

	REQUIRE(VALID_DISPATCHMGR(mgr));
	REQUIRE(sockmgr != NULL);
	REQUIRE(localaddr != NULL);
	REQUIRE(taskmgr != NULL);
	REQUIRE(buffersize >= 512 && buffersize < (64 * 1024));
	REQUIRE(maxbuffers > 0);
	REQUIRE(buckets < 2097169);  /* next prime > 65536 * 32 */
	REQUIRE(increment > buckets);
	REQUIRE(dispp != NULL && *dispp == NULL);
	REQUIRE((attributes & DNS_DISPATCHATTR_TCP) == 0);

	result = dns_dispatchmgr_setudp(mgr, buffersize, maxbuffers,
					buckets, increment);
	if (result != ISC_R_SUCCESS)
		return (result);

	LOCK(&mgr->lock);

	/*
	 * First, see if we have a dispatcher that matches.
	 */
	disp = NULL;
	result = dispatch_find(mgr, localaddr, attributes, mask, &disp);
	if (result == ISC_R_SUCCESS) {
		disp->refcount++;

		if (disp->maxrequests < maxrequests)
			disp->maxrequests = maxrequests;

		if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) == 0 &&
		    (attributes & DNS_DISPATCHATTR_NOLISTEN) != 0)
		{
			disp->attributes |= DNS_DISPATCHATTR_NOLISTEN;
			if (disp->recv_pending != 0)
				isc_socket_cancel(disp->socket, disp->task,
						  ISC_SOCKCANCEL_RECV);
		}

		UNLOCK(&disp->lock);
		UNLOCK(&mgr->lock);

		*dispp = disp;

		return (ISC_R_SUCCESS);
	}

	/*