1 files changed, 261 insertions, 0 deletions
diff --git a/lib/dns/portlist.c b/lib/dns/portlist.c
new file mode 100644
index 0000000..7de7178
--- /dev/null
+++ b/lib/dns/portlist.c
@@ -0,0 +1,261 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+
+/*! \file */
+
+#include <config.h>
+
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include <isc/magic.h>
+#include <isc/mem.h>
+#include <isc/mutex.h>
+#include <isc/net.h>
+#include <isc/refcount.h>
+#include <isc/result.h>
+#include <isc/string.h>
+#include <isc/types.h>
+#include <isc/util.h>
+
+#include <dns/types.h>
+#include <dns/portlist.h>
+
+#define DNS_PORTLIST_MAGIC	ISC_MAGIC('P','L','S','T')
+#define DNS_VALID_PORTLIST(p)	ISC_MAGIC_VALID(p, DNS_PORTLIST_MAGIC)
+
+typedef struct dns_element {
+	in_port_t	port;
+	uint16_t	flags;
+} dns_element_t;
+
+struct dns_portlist {
+	unsigned int	magic;
+	isc_mem_t	*mctx;
+	isc_refcount_t	refcount;
+	isc_mutex_t	lock;
+	dns_element_t 	*list;
+	unsigned int	allocated;
+	unsigned int	active;
+};
+
+#define DNS_PL_INET	0x0001
+#define DNS_PL_INET6	0x0002
+#define DNS_PL_ALLOCATE	16
+
+static int
+compare(const void *arg1, const void *arg2) {
+	const dns_element_t *e1 = (const dns_element_t *)arg1;
+	const dns_element_t *e2 = (const dns_element_t *)arg2;
+
+	if (e1->port < e2->port)
+		return (-1);
+	if (e1->port > e2->port)
+		return (1);
+	return (0);
+}
+
+isc_result_t
+dns_portlist_create(isc_mem_t *mctx, dns_portlist_t **portlistp) {
+	dns_portlist_t *portlist;
+	isc_result_t result;
+
+	REQUIRE(portlistp != NULL && *portlistp == NULL);
+
+	portlist = isc_mem_get(mctx, sizeof(*portlist));
+	if (portlist == NULL)
+		return (ISC_R_NOMEMORY);
+	result = isc_mutex_init(&portlist->lock);
+	if (result != ISC_R_SUCCESS) {
+		isc_mem_put(mctx, portlist, sizeof(*portlist));
+		return (result);
+	}
+	result = isc_refcount_init(&portlist->refcount, 1);
+	if (result != ISC_R_SUCCESS) {
+		DESTROYLOCK(&portlist->lock);
+		isc_mem_put(mctx, portlist, sizeof(*portlist));
+		return (result);
+	}
+	portlist->list = NULL;
+	portlist->allocated = 0;
+	portlist->active = 0;
+	portlist->mctx = NULL;
+	isc_mem_attach(mctx, &portlist->mctx);
+	portlist->magic = DNS_PORTLIST_MAGIC;
+	*portlistp = portlist;
+	return (ISC_R_SUCCESS);
+}
+
+static dns_element_t *
+find_port(dns_element_t *list, unsigned int len, in_port_t port) {
+	unsigned int xtry = len / 2;
+	unsigned int min = 0;
+	unsigned int max = len - 1;
+	unsigned int last = len;
+
+	for (;;) {
+		if (list[xtry].port == port)
+			return (&list[xtry]);
+		if (port > list[xtry].port) {
+			if (xtry == max)
+				break;
+			min = xtry;
+			xtry = xtry + (max - xtry + 1) / 2;
+			INSIST(xtry <= max);
+			if (xtry == last)
+				break;
+			last = min;
+		} else {
+			if (xtry == min)
+				break;
+			max = xtry;
+			xtry = xtry - (xtry - min + 1) / 2;
+			INSIST(xtry >= min);
+			if (xtry == last)
+				break;
+			last = max;
+		}
+	}
+	return (NULL);
+}
+
+isc_result_t
+dns_portlist_add(dns_portlist_t *portlist, int af, in_port_t port) {
+	dns_element_t *el;
+	isc_result_t result;
+
+	REQUIRE(DNS_VALID_PORTLIST(portlist));
+	REQUIRE(af == AF_INET || af == AF_INET6);
+
+	LOCK(&portlist->lock);
+	if (portlist->active != 0) {
+		el = find_port(portlist->list, portlist->active, port);
+		if (el != NULL) {
+			if (af == AF_INET)
+				el->flags |= DNS_PL_INET;
+			else
+				el->flags |= DNS_PL_INET6;
+			result = ISC_R_SUCCESS;
+			goto unlock;
+		}
+	}
+
+	if (portlist->allocated <= portlist->active) {
+		unsigned int allocated;
+		allocated = portlist->allocated + DNS_PL_ALLOCATE;
+		el = isc_mem_get(portlist->mctx, sizeof(*el) * allocated);
+		if (el == NULL) {
+			result = ISC_R_NOMEMORY;
+			goto unlock;
+		}
+		if (portlist->list != NULL) {
+			memmove(el, portlist->list,
+				portlist->allocated * sizeof(*el));
+			isc_mem_put(portlist->mctx, portlist->list,
+				    portlist->allocated * sizeof(*el));
+		}
+		portlist->list = el;
+		portlist->allocated = allocated;
+	}
+	portlist->list[portlist->active].port = port;
+	if (af == AF_INET)
+		portlist->list[portlist->active].flags = DNS_PL_INET;
+	else
+		portlist->list[portlist->active].flags = DNS_PL_INET6;
+	portlist->active++;
+	qsort(portlist->list, portlist->active, sizeof(*el), compare);
+	result = ISC_R_SUCCESS;
+ unlock:
+	UNLOCK(&portlist->lock);
+	return (result);
+}
+
+void
+dns_portlist_remove(dns_portlist_t *portlist, int af, in_port_t port) {
+	dns_element_t *el;
+
+	REQUIRE(DNS_VALID_PORTLIST(portlist));
+	REQUIRE(af == AF_INET || af == AF_INET6);
+
+	LOCK(&portlist->lock);
+	if (portlist->active != 0) {
+		el = find_port(portlist->list, portlist->active, port);
+		if (el != NULL) {
+			if (af == AF_INET)
+				el->flags &= ~DNS_PL_INET;
+			else
+				el->flags &= ~DNS_PL_INET6;
+			if (el->flags == 0) {
+				*el = portlist->list[portlist->active];
+				portlist->active--;
+				qsort(portlist->list, portlist->active,
+				      sizeof(*el), compare);
+			}
+		}
+	}
+	UNLOCK(&portlist->lock);
+}
+
+bool
+dns_portlist_match(dns_portlist_t *portlist, int af, in_port_t port) {
+	dns_element_t *el;
+	bool result = false;
+
+	REQUIRE(DNS_VALID_PORTLIST(portlist));
+	REQUIRE(af == AF_INET || af == AF_INET6);
+	LOCK(&portlist->lock);
+	if (portlist->active != 0) {
+		el = find_port(portlist->list, portlist->active, port);
+		if (el != NULL) {
+			if (af == AF_INET && (el->flags & DNS_PL_INET) != 0)
+				result = true;
+			if (af == AF_INET6 && (el->flags & DNS_PL_INET6) != 0)
+				result = true;
+		}
+	}
+	UNLOCK(&portlist->lock);
+	return (result);
+}
+
+void
+dns_portlist_attach(dns_portlist_t *portlist, dns_portlist_t **portlistp) {
+
+	REQUIRE(DNS_VALID_PORTLIST(portlist));
+	REQUIRE(portlistp != NULL && *portlistp == NULL);
+
+	isc_refcount_increment(&portlist->refcount, NULL);
+	*portlistp = portlist;
+}
+
+void
+dns_portlist_detach(dns_portlist_t **portlistp) {
+	dns_portlist_t *portlist;
+	unsigned int count;
+
+	REQUIRE(portlistp != NULL);
+	portlist = *portlistp;
+	REQUIRE(DNS_VALID_PORTLIST(portlist));
+	*portlistp = NULL;
+	isc_refcount_decrement(&portlist->refcount, &count);
+	if (count == 0) {
+		portlist->magic = 0;
+		isc_refcount_destroy(&portlist->refcount);
+		if (portlist->list != NULL)
+			isc_mem_put(portlist->mctx, portlist->list,
+				    portlist->allocated *
+				    sizeof(*portlist->list));
+		DESTROYLOCK(&portlist->lock);
+		isc_mem_putanddetach(&portlist->mctx, portlist,
+				     sizeof(*portlist));
+	}
+}