libpurple/protocols/jabber/parser.c

Tue, 06 Oct 2009 03:25:26 +0000

author
Paul Aurich <darkrain42@pidgin.im>
date
Tue, 06 Oct 2009 03:25:26 +0000
changeset 28623
4f7f9d7bb23d
parent 28322
ac8fec1d2234
child 28855
c5bc85f9c00e
child 28986
57ed606f526d
permissions
-rw-r--r--

jabber: Re-arrange the code that detects legacy servers so that we don't stomp over "Host Unknown" errors.

Legacy servers don't send <stream:features>, so we need to notice when
we've finished the opening <stream:stream> tag and, if there was no
version, start authentication right then. This was causingon other valid
errors (like the server complaining it's not who we think it is) to be
replaced by a complaint "You require encryption...". Closes #10450.

This seems to work in all the cases I've tested (including with jabberd14).

/*
 * purple - Jabber XML parser stuff
 *
 * Purple is the legal property of its developers, whose names are too numerous
 * to list here.  Please refer to the COPYRIGHT file distributed with this
 * source distribution.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA
 *
 */
#include "internal.h"

#include <libxml/parser.h>

#include "connection.h"
#include "debug.h"
#include "jabber.h"
#include "parser.h"
#include "util.h"
#include "xmlnode.h"

static void
jabber_parser_element_start_libxml(void *user_data,
				   const xmlChar *element_name, const xmlChar *prefix, const xmlChar *namespace,
				   int nb_namespaces, const xmlChar **namespaces,
				   int nb_attributes, int nb_defaulted, const xmlChar **attributes)
{
	JabberStream *js = user_data;
	xmlnode *node;
	int i, j;

	if(!element_name) {
		return;
	} else if(!xmlStrcmp(element_name, (xmlChar*) "stream")) {
		js->protocol_version = JABBER_PROTO_0_9;
		for(i=0; i < nb_attributes * 5; i += 5) {
			int attrib_len = attributes[i+4] - attributes[i+3];
			char *attrib = g_malloc(attrib_len + 1);
			memcpy(attrib, attributes[i+3], attrib_len);
			attrib[attrib_len] = '\0';

			if(!xmlStrcmp(attributes[i], (xmlChar*) "version")
					&& !strcmp(attrib, "1.0")) {
				js->protocol_version = JABBER_PROTO_1_0;
				g_free(attrib);
			} else if(!xmlStrcmp(attributes[i], (xmlChar*) "id")) {
				g_free(js->stream_id);
				js->stream_id = attrib;
			} else {
				g_free(attrib);
			}
		}
	} else {

		if(js->current)
			node = xmlnode_new_child(js->current, (const char*) element_name);
		else
			node = xmlnode_new((const char*) element_name);
		xmlnode_set_namespace(node, (const char*) namespace);
		xmlnode_set_prefix(node, (const char *)prefix);

		if (nb_namespaces != 0) {
			node->namespace_map = g_hash_table_new_full(
				g_str_hash, g_str_equal, g_free, g_free);

			for (i = 0, j = 0; i < nb_namespaces; i++, j += 2) {
				const char *key = (const char *)namespaces[j];
				const char *val = (const char *)namespaces[j + 1];
				g_hash_table_insert(node->namespace_map,
					g_strdup(key ? key : ""), g_strdup(val ? val : ""));
			}
		}
		for(i=0; i < nb_attributes * 5; i+=5) {
			const char *name = (const char *)attributes[i];
			const char *prefix = (const char *)attributes[i+1];
			const char *attrib_ns = (const char *)attributes[i+2];
			char *txt;
			int attrib_len = attributes[i+4] - attributes[i+3];
			char *attrib = g_malloc(attrib_len + 1);

			memcpy(attrib, attributes[i+3], attrib_len);
			attrib[attrib_len] = '\0';

			txt = attrib;
			attrib = purple_unescape_html(txt);
			g_free(txt);
			xmlnode_set_attrib_full(node, name, attrib_ns, prefix, attrib);
			g_free(attrib);
		}

		js->current = node;
	}
}

static void
jabber_parser_element_end_libxml(void *user_data, const xmlChar *element_name,
				 const xmlChar *prefix, const xmlChar *namespace)
{
	JabberStream *js = user_data;

	if(!js->current)
		return;

	if(js->current->parent) {
		if(!xmlStrcmp((xmlChar*) js->current->name, element_name))
			js->current = js->current->parent;
	} else {
		xmlnode *packet = js->current;
		js->current = NULL;
		jabber_process_packet(js, &packet);
		if (packet != NULL)
			xmlnode_free(packet);
	}
}

static void
jabber_parser_element_text_libxml(void *user_data, const xmlChar *text, int text_len)
{
	JabberStream *js = user_data;

	if(!js->current)
		return;

	if(!text || !text_len)
		return;

	xmlnode_insert_data(js->current, (const char*) text, text_len);
}

static void
jabber_parser_structured_error_handler(void *user_data, xmlErrorPtr error)
{
	JabberStream *js = user_data;

	if (error->level == XML_ERR_WARNING && error->message != NULL
			&& strcmp(error->message, "xmlns: URI vcard-temp is not absolute\n") == 0)
		/*
		 * This message happens when parsing vcards, and is normal, so don't
		 * bother logging it because people scare easily.
		 */
		return;

	purple_debug_error("jabber", "XML parser error for JabberStream %p: "
								 "Domain %i, code %i, level %i: %s",
					   js,
					   error->domain, error->code, error->level,
					   (error->message ? error->message : "(null)\n"));
}

static xmlSAXHandler jabber_parser_libxml = {
	NULL,									/*internalSubset*/
	NULL,									/*isStandalone*/
	NULL,									/*hasInternalSubset*/
	NULL,									/*hasExternalSubset*/
	NULL,									/*resolveEntity*/
	NULL,									/*getEntity*/
	NULL,									/*entityDecl*/
	NULL,									/*notationDecl*/
	NULL,									/*attributeDecl*/
	NULL,									/*elementDecl*/
	NULL,									/*unparsedEntityDecl*/
	NULL,									/*setDocumentLocator*/
	NULL,									/*startDocument*/
	NULL,									/*endDocument*/
	NULL,									/*startElement*/
	NULL,									/*endElement*/
	NULL,									/*reference*/
	jabber_parser_element_text_libxml,		/*characters*/
	NULL,									/*ignorableWhitespace*/
	NULL,									/*processingInstruction*/
	NULL,									/*comment*/
	NULL,									/*warning*/
	NULL,									/*error*/
	NULL,									/*fatalError*/
	NULL,									/*getParameterEntity*/
	NULL,									/*cdataBlock*/
	NULL,									/*externalSubset*/
	XML_SAX2_MAGIC,							/*initialized*/
	NULL,									/*_private*/
	jabber_parser_element_start_libxml,		/*startElementNs*/
	jabber_parser_element_end_libxml,		/*endElementNs*/
	jabber_parser_structured_error_handler	/*serror*/
};

void
jabber_parser_setup(JabberStream *js)
{
	/* This seems backwards, but it makes sense. The libxml code creates
	 * the parser context when you try to use it (this way, it can figure
	 * out the encoding at creation time. So, setting up the parser is
	 * just a matter of destroying any current parser. */
	jabber_parser_free(js);
}

void jabber_parser_free(JabberStream *js) {
	if (js->context) {
		xmlParseChunk(js->context, NULL,0,1);
		xmlFreeParserCtxt(js->context);
		js->context = NULL;
	}
}

void jabber_parser_process(JabberStream *js, const char *buf, int len)
{
	int ret;

	if (js->context == NULL) {
		/* libxml inconsistently starts parsing on creating the
		 * parser, so do a ParseChunk right afterwards to force it. */
		js->context = xmlCreatePushParserCtxt(&jabber_parser_libxml, js, buf, len, NULL);
		xmlParseChunk(js->context, "", 0, 0);
	} else if ((ret = xmlParseChunk(js->context, buf, len, 0)) != XML_ERR_OK) {
		xmlError *err = xmlCtxtGetLastError(js->context);
		/*
		 * libxml2 uses a global setting to determine whether or not to store
		 * warnings.  Other libraries may set this, which causes err to be
		 * NULL. See #8136 for details.
		 */
		xmlErrorLevel level = XML_ERR_WARNING;

		if (err)
			level = err->level;

		switch (level) {
			case XML_ERR_NONE:
				purple_debug_info("jabber", "xmlParseChunk returned info %i\n", ret);
				break;
			case XML_ERR_WARNING:
				purple_debug_warning("jabber", "xmlParseChunk returned warning %i\n", ret);
				break;
			case XML_ERR_ERROR:
				purple_debug_error("jabber", "xmlParseChunk returned error %i\n", ret);
				break;
			case XML_ERR_FATAL:
				purple_debug_error("jabber", "xmlParseChunk returned fatal %i\n", ret);
				purple_connection_error_reason (js->gc,
				                                PURPLE_CONNECTION_ERROR_NETWORK_ERROR,
				                                _("XML Parse error"));
				break;
		}
	}

	if (js->protocol_version == JABBER_PROTO_0_9 && !js->gc->disconnect_timeout &&
			(js->state == JABBER_STREAM_INITIALIZING ||
			 js->state == JABBER_STREAM_INITIALIZING_ENCRYPTION)) {
		/*
		 * Legacy servers don't advertise features, so if we've just gotten
		 * the opening <stream:stream> and there was no version, we need to
		 * immediately start legacy IQ auth.
		 */
		js->auth_type = JABBER_AUTH_IQ_AUTH;
		jabber_stream_set_state(js, JABBER_STREAM_AUTHENTICATING);
	}
}

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