/*
* Copyright (c) 2011, Jonathan Schleifer <js@webkeks.org>
* Copyright (c) 2011, Florian Zeitz <florob@babelmonkeys.de>
*
* https://webkeks.org/git/?p=objxmpp.git
*
* 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.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdlib.h>
#include <assert.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <sys/types.h>
#include <openssl/rand.h>
#import "XMPPSRVLookup.h"
@implementation XMPPSRVEntry
+ entryWithPriority: (uint16_t)priority
weight: (uint16_t)weight
port: (uint16_t)port
target: (OFString*)target
{
return [[[self alloc] initWithPriority: priority
weight: weight
port: port
target: target] autorelease];
}
+ entryWithResourceRecord: (ns_rr)resourceRecord
handle: (ns_msg)handle
{
return [[[self alloc] initWithResourceRecord: resourceRecord
handle: handle] autorelease];
}
- init
{
@try {
[self doesNotRecognizeSelector: _cmd];
} @catch (id e) {
[self release];
@throw e;
}
abort();
}
- initWithPriority: (uint16_t)priority
weight: (uint16_t)weight
port: (uint16_t)port
target: (OFString*)target
{
self = [super init];
@try {
_priority = priority;
_weight = weight;
_port = port;
_target = [target copy];
} @catch (id e) {
[self release];
@throw e;
}
return self;
}
- initWithResourceRecord: (ns_rr)resourceRecord
handle: (ns_msg)handle
{
self = [super init];
@try {
const uint16_t *rdata;
char buffer[NS_MAXDNAME];
rdata = (const uint16_t*)(void*)ns_rr_rdata(resourceRecord);
_priority = ntohs(rdata[0]);
_weight = ntohs(rdata[1]);
_port = ntohs(rdata[2]);
if (dn_expand(ns_msg_base(handle), ns_msg_end(handle),
(uint8_t*)&rdata[3], buffer, NS_MAXDNAME) < 1)
@throw [OFInitializationFailedException
exceptionWithClass: [self class]];
_target = [[OFString alloc]
initWithCString: buffer
encoding: OF_STRING_ENCODING_NATIVE];
} @catch (id e) {
[self release];
@throw e;
}
return self;
}
- (void)dealloc
{
[_target release];
[super dealloc];
}
- (OFString*)description
{
return [OFString stringWithFormat:
@"<%@ priority: %" PRIu16 @", weight: %" PRIu16 @", target: %@:%"
PRIu16 @">", [self class], _priority, _weight, _target, _port];
}
- (uint16_t)priority
{
return _priority;
}
- (uint16_t)weight
{
return _weight;
}
- (void)setAccumulatedWeight: (uint32_t)accumulatedWeight
{
_accumulatedWeight = accumulatedWeight;
}
- (uint32_t)accumulatedWeight
{
return _accumulatedWeight;
}
- (uint16_t)port
{
return _port;
}
- (OFString*)target
{
OF_GETTER(_target, true)
}
@end
@implementation XMPPSRVLookup
+ lookupWithDomain: (OFString*)domain
{
return [[[self alloc] initWithDomain: domain] autorelease];
}
- initWithDomain: (OFString*)domain
{
self = [super init];
@try {
_list = [[OFList alloc] init];
_domain = [domain copy];
[self XMPP_lookup];
} @catch (id e) {
[self release];
@throw e;
}
return self;
}
- (void)dealloc
{
[_list release];
[_domain release];
[super dealloc];
}
- (OFString*)domain;
{
OF_GETTER(_domain, true)
}
- (void)XMPP_lookup
{
OFAutoreleasePool *pool = [[OFAutoreleasePool alloc] init];
unsigned char *answer = NULL;
size_t pageSize = [OFSystemInfo pageSize];
OFString *request;
request = [OFString stringWithFormat: @"_xmpp-client._tcp.%@", _domain];
@try {
int answerLen, resourceRecordCount, i;
ns_rr resourceRecord;
ns_msg handle;
if (res_ninit(&_resState))
@throw [OFAddressTranslationFailedException
exceptionWithHost: _domain];
answer = [self allocMemoryWithSize: pageSize];
answerLen = res_nsearch(&_resState,
[request cStringWithEncoding: OF_STRING_ENCODING_NATIVE],
ns_c_in, ns_t_srv, answer, (int)pageSize);
if ((answerLen == -1) && ((h_errno == HOST_NOT_FOUND) ||
(h_errno == NO_DATA)))
return;
if (answerLen < 1 || answerLen > pageSize)
@throw [OFAddressTranslationFailedException
exceptionWithHost: _domain];
if (ns_initparse(answer, answerLen, &handle))
@throw [OFAddressTranslationFailedException
exceptionWithHost: _domain];
resourceRecordCount = ns_msg_count(handle, ns_s_an);
for (i = 0; i < resourceRecordCount; i++) {
if (ns_parserr(&handle, ns_s_an, i, &resourceRecord))
continue;
if (ns_rr_type(resourceRecord) != ns_t_srv ||
ns_rr_class(resourceRecord) != ns_c_in)
continue;
[self XMPP_addEntry: [XMPPSRVEntry
entryWithResourceRecord: resourceRecord
handle: handle]];
}
} @finally {
[self freeMemory: answer];
#ifdef HAVE_RES_NDESTROY
res_ndestroy(&_resState);
#endif
}
[pool release];
}
- (void)XMPP_addEntry: (XMPPSRVEntry*)entry
{
OFAutoreleasePool *pool;
OFList *subList;
of_list_object_t *iter;
/* Look if there already is a list with the priority */
for (iter = [_list firstListObject]; iter != NULL; iter = iter->next) {
if ([[iter->object firstObject] priority] == [entry priority]) {
/*
* RFC 2782 says those with weight 0 should be at the
* beginning of the list.
*/
if ([entry weight] > 0)
[iter->object appendObject: entry];
else
[iter->object prependObject: entry];
return;
}
/* We can't have one if the priority is already bigger */
if ([[iter->object firstObject] priority] > [entry priority])
break;
}
pool = [[OFAutoreleasePool alloc] init];
subList = [OFList list];
[subList appendObject: entry];
if (iter != NULL)
[_list insertObject: subList
beforeListObject: iter];
else
[_list appendObject: subList];
[pool release];
}
- (OFEnumerator*)objectEnumerator
{
return [[[XMPPSRVEnumerator alloc] initWithList: _list] autorelease];
}
@end
@implementation XMPPSRVEnumerator
- initWithList: (OFList*)list_
{
self = [super init];
@try {
list = [list_ copy];
} @catch (id e) {
[self release];
@throw e;
}
return self;
}
- (id)nextObject
{
XMPPSRVEntry *ret = nil;
of_list_object_t *iter;
uint32_t totalWeight = 0;
if (done)
return nil;
if (listIter == NULL)
listIter = [list firstListObject];
if (listIter == NULL)
return nil;
if (subListCopy == nil)
subListCopy = [listIter->object copy];
for (iter = [subListCopy firstListObject]; iter != NULL;
iter = iter->next) {
totalWeight += [iter->object weight];
[iter->object setAccumulatedWeight: totalWeight];
}
if ([subListCopy count] > 0) {
uint32_t randomWeight;
RAND_pseudo_bytes((uint8_t*)&randomWeight, sizeof(uint32_t));
randomWeight %= (totalWeight + 1);
for (iter = [subListCopy firstListObject]; iter != NULL;
iter = iter->next) {
if ([iter->object accumulatedWeight] >= randomWeight) {
ret = [[iter->object retain] autorelease];
[subListCopy removeListObject: iter];
break;
}
}
}
if ([subListCopy count] == 0) {
[subListCopy release];
subListCopy = nil;
listIter = listIter->next;
if (listIter == NULL)
done = true;
}
return ret;
}
- (void)reset
{
listIter = NULL;
[subListCopy release];
subListCopy = nil;
done = false;
}
@end