/*
* 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