Add support for SRV records

configure.ac

@@ -33,6 +33,37 @@ AS_IF([test x"$enable_static" = x"yes" -o x"$enable_shared" = x"no"], [
 	AC_SUBST(OBJXMPP_STATIC_LIB, "libobjxmpp.a")
 ])
 
+# This is an adapted version of what glib does for res_query
+# It should recognize the correct library on (at least) Linux,
+# NetBSD, FreeBSD, Mac OS X and Haiku
+AC_MSG_CHECKING([for res_nsearch])
+AC_TRY_LINK([#include <sys/types.h>
+	     #include <netinet/in.h>
+	     #include <arpa/nameser.h>
+	     #include <resolv.h>],
+	     [res_nsearch(&_res, "test", 0, 0, (void *)0, 0);],
+	     [AC_MSG_RESULT([yes])],
+	     [save_libs="$LIBS"
+	      LIBS="$LIBS -lresolv"
+	      AC_TRY_LINK([#include <sys/types.h>
+			   #include <netinet/in.h>
+			   #include <arpa/nameser.h>
+			   #include <resolv.h>],
+			   [res_nsearch(&_res, "test", 0, 0, (void *)0, 0);],
+			   [AC_MSG_RESULT([in -lresolv])],
+			   [LIBS="$save_libs -lnetwork"
+			    AC_TRY_LINK([#include <sys/types.h>
+					 #include <netinet/in.h>
+					 #include <arpa/nameser.h>
+					 #include <resolv.h>],
+					[res_nsearch(&_res, "test", 0, 0, (void *)0, 0);],
+					[AC_MSG_RESULT([in -lnetwork])],
+					[LIBS="$save_libs -lbind"
+					 AC_TRY_LINK([#include <resolv.h>],
+						     [res_nsearch(&_res, "test", 0, 0, (void *)0, 0);],
+						     [AC_MSG_RESULT([in -lbind])],
+						     [AC_MSG_ERROR(not found)])])])])
+
 AC_CHECK_LIB(objopenssl, main, [
 	LIBS="$LIBS -lobjopenssl -lcrypto"
 ], [

src/Makefile

@@ -16,6 +16,7 @@ SRCS = XMPPAuthenticator.m	\
        XMPPRoster.m		\
        XMPPRosterItem.m		\
        XMPPSCRAMAuth.m		\
+       XMPPSRVEnumerator.m	\
        XMPPStanza.m
 
 INCLUDES = ${SRCS:.m=.h}	\

src/XMPPConnection.m

@@ -31,6 +31,7 @@
 #import <ObjOpenSSL/SSLSocket.h>
 
 #import "XMPPConnection.h"
+#import "XMPPSRVEnumerator.h"
 #import "XMPPSCRAMAuth.h"
 #import "XMPPPLAINAuth.h"
 #import "XMPPStanza.h"
@@ -196,7 +197,25 @@
 - (void)connect
 {
 	OFAutoreleasePool *pool = [[OFAutoreleasePool alloc] init];
+	XMPPSRVEnumerator *SRVEnumerator =
+		[XMPPSRVEnumerator enumeratorWithDomain: server];
+	XMPPSRVEntry *candidate;
 
+	while ((candidate = [SRVEnumerator nextObject])) {
+		@try {
+			[sock connectToHost: [candidate target]
+				     onPort: [candidate port]];
+			break;
+		} @catch (id e) {
+			if (([e class] == [OFAddressTranslationFailedException
+					class]) || ([e class] ==
+					[OFConnectionFailedException class]))
+				continue;
+			else
+				@throw e;
+		}
+	}
+	if (!candidate)
 		[sock connectToHost: server
 			     onPort: port];
 	[self XMPP_startStream];

src/XMPPSRVEnumerator.h

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2011, Florian Zeitz <florob@babelmonkeys.de>
+ *
+ * https://webkeks.org/hg/objxmpp/
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice is present in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <arpa/nameser.h>
+#import <ObjFW/ObjFW.h>
+
+@interface XMPPSRVEntry: OFObject
+{
+	uint16_t priority;
+	uint16_t weight;
+	uint16_t port;
+	OFString *target;
+}
+#ifdef OF_HAVE_PROPERTIES
+@property uint16_t priority;
+@property uint16_t weight;
+@property uint16_t port;
+@property (copy) OFString *target;
+#endif
+
+- (void) setPriority: (uint16_t)priority_;
+- (uint16_t) priority;
+- (void) setWeight: (uint16_t)weight_;
+- (uint16_t) weight;
+- (void) setPort: (uint16_t)port_;
+- (uint16_t) port;
+- (void) setTarget: (OFString*)target_;
+- (OFString*) target;
+@end
+
+@interface XMPPSRVEnumerator: OFEnumerator <OFFastEnumeration>
+{
+	OFString *domain;
+	OFList *priorityList;
+}
+#ifdef OF_HAVE_PROPERTIES
+@property (copy) OFString *domain;
+#endif
+
++ enumeratorWithDomain: (OFString*)domain;
+
+- initWithDomain: (OFString*)domain;
+- (void) setDomain: (OFString*)domain;
+- (OFString*) domain;
+- (void)XMPP_parseSRVRRWithHandle: (const ns_msg)handle
+			       RR: (const ns_rr)rr
+			   result: (XMPPSRVEntry*)result;
+- (void)XMPP_addSRVEntry: (XMPPSRVEntry*)item
+    toSortedPriorityList: (OFList*)list;
+@end

src/XMPPSRVEnumerator.m

@@ -0,0 +1,260 @@
+/*
+ * Copyright (c) 2011, Florian Zeitz <florob@babelmonkeys.de>
+ *
+ * https://webkeks.org/hg/objxmpp/
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice is present in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <resolv.h>
+#include <sys/types.h>
+#include <openssl/rand.h>
+#include <assert.h>
+
+#import "XMPPSRVEnumerator.h"
+
+@implementation XMPPSRVEntry
+- (void)dealloc
+{
+	[target release];
+
+	[super dealloc];
+}
+
+- (OFString*)description
+{
+	return [OFString stringWithFormat: @"priority: %" PRIu16
+				@" weight: %" PRIu16
+				@" target: %@:%" PRIu16, priority, weight,
+				target, port];
+}
+
+- (void)setPriority: (uint16_t)priority_
+{
+	priority = priority_;
+}
+
+- (uint16_t)priority
+{
+	return priority;
+}
+
+- (void)setWeight: (uint16_t)weight_
+{
+	weight = weight_;
+}
+
+- (uint16_t)weight
+{
+	return weight;
+}
+
+- (void)setPort: (uint16_t)port_
+{
+	port = port_;
+}
+
+- (uint16_t)port
+{
+	return port;
+}
+
+- (void)setTarget: (OFString*)target_
+{
+	OFString *old = target;
+	target = [target_ copy];
+	[old release];
+}
+
+- (OFString*)target
+{
+	return [[target copy] autorelease];
+}
+@end
+
+@implementation XMPPSRVEnumerator
++ enumeratorWithDomain: (OFString*)domain_
+{
+	return [[[self alloc] initWithDomain: domain_] autorelease];
+}
+
+- initWithDomain: (OFString*)domain_
+{
+	self = [super init];
+	priorityList = [[OFList alloc] init];
+	[self setDomain: domain_];
+
+	return self;
+}
+
+- (void)dealloc
+{
+	[priorityList release];
+	[domain release];
+
+	[super dealloc];
+}
+
+- (void)setDomain: (OFString*)domain_
+{
+	OFString *old = domain;
+	domain = [domain_ copy];
+	[old release];
+	[self reset];
+}
+
+- (OFString*)domain;
+{
+	return [[domain copy] autorelease];
+}
+
+- (void)XMPP_parseSRVRRWithHandle: (const ns_msg)handle
+			       RR: (const ns_rr)rr
+			   result: (XMPPSRVEntry*)result
+{
+	const uint16_t *rdata = (uint16_t*) ns_rr_rdata(rr);
+	char target[NS_MAXDNAME];
+	[result setPriority: ntohs(rdata[0])];
+	[result setWeight: ntohs(rdata[1])];
+	[result setPort: ntohs(rdata[2])];
+	dn_expand(ns_msg_base(handle), ns_msg_end(handle),
+			(uint8_t*) &rdata[3], target, NS_MAXDNAME);
+	[result setTarget: [OFString stringWithCString: target]];
+}
+
+- (id)nextObject
+{
+	if ([priorityList firstListObject]) {
+		uint16_t weight = 0;
+		of_list_object_t *iter;
+		XMPPSRVEntry *ret;
+		OFList *weightList = [priorityList firstObject];
+		uint16_t maximumWeight = [[weightList lastObject] weight];
+
+		if (maximumWeight) {
+			RAND_pseudo_bytes((unsigned char *)&weight, 2);
+			weight %= maximumWeight;
+		}
+
+		iter = [weightList firstListObject];
+		while (iter) {
+			if (weight <= [iter->object weight]) {
+				ret = [iter->object retain];
+				[weightList removeListObject: iter];
+				if (![weightList firstListObject])
+					[priorityList removeListObject:
+						[priorityList firstListObject]];
+				return [ret autorelease];
+			}
+			iter = iter->next;
+		}
+		assert(0);
+	}
+
+	return nil;
+}
+
+- (int)countByEnumeratingWithState: (of_fast_enumeration_state_t*)state
+			   objects: (id*)objects
+			     count: (int)count
+{
+	int len = 0;
+	XMPPSRVEntry *entry = [self nextObject];
+	state->itemsPtr = objects;
+	while ((len < count) && entry) {
+		state->mutationsPtr = (unsigned long *)self;
+		objects[len++] = entry;
+		entry = [self nextObject];
+	}
+	return len;
+}
+
+- (void)reset
+{
+	int i, rrCount;
+	unsigned char *answer;
+	OFString *request;
+	OFAutoreleasePool *pool = [[OFAutoreleasePool alloc] init];
+
+	request = [OFString stringWithFormat: @"_xmpp-client._tcp.%@", domain];
+	answer = [self allocMemoryWithSize: NS_MAXMSG];
+
+	res_ninit(&_res);
+	if (!(res_nsearch(&_res, [request cString], ns_c_in, ns_t_srv, answer,
+				NS_MAXMSG) < 0)) {
+		ns_rr rr;
+		ns_msg handle;
+
+		ns_initparse(answer, NS_MAXMSG, &handle);
+		rrCount = ns_msg_count(handle, ns_s_an);
+		for (i = 0; i < rrCount ; i++) {
+			XMPPSRVEntry *result = [[XMPPSRVEntry alloc] init];
+			ns_parserr(&handle, ns_s_an, i, &rr);
+			if ((ns_rr_type(rr) != ns_t_srv)
+					|| ns_rr_class(rr) != ns_c_in)
+				@throw [OFInvalidServerReplyException
+					newWithClass: isa];
+
+			[self XMPP_parseSRVRRWithHandle: handle
+						     RR: rr
+						 result: result];
+
+			[self XMPP_addSRVEntry: result
+			  toSortedPriorityList: priorityList];
+		}
+	}
+	[self freeMemory: answer];
+	[pool release];
+
+
+}
+
+- (void)XMPP_addSRVEntry: (XMPPSRVEntry*)item
+    toSortedPriorityList: (OFList*)list
+{
+	of_list_object_t *priorityIter =
+		[list firstListObject];
+	while (1) {
+		if (priorityIter == NULL ||
+				[[priorityIter->object firstObject]
+					priority] > [item priority]) {
+			OFList *newList = [OFList list];
+			[newList appendObject: item];
+			if (priorityIter)
+				[list insertObject: newList
+				  beforeListObject: priorityIter];
+			else
+				[list appendObject: newList];
+			break;
+		}
+		if ([[priorityIter->object firstObject] priority]
+				== [item priority]) {
+			if ([item weight] == 0)
+				[priorityIter->object prependObject: item];
+			else {
+				[item setWeight: [item weight] +
+				    [[priorityIter->object lastObject] weight]];
+				[priorityIter->object appendObject: item];
+			}
+			break;
+		}
+		priorityIter = priorityIter->next;
+	}
+}
+@end

tests/test.m

@@ -102,8 +102,8 @@ OF_APPLICATION_DELEGATE(AppDelegate)
 	[conn setPassword: [arguments objectAtIndex: 2]];
 	[conn setResource: @"ObjXMPP"];
 
-	[conn connect];
 	@try {
+		[conn connect];
 		[conn handleConnection];
 	} @catch (id e) {
 		of_log(@"%@", e);