/*
* Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The OpenAirInterface Software Alliance licenses this file to You under
* the OAI Public License, Version 1.1 (the "License"); you may not use this file
* except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.openairinterface.org/?page_id=698
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*-------------------------------------------------------------------------------
* For more information about the OpenAirInterface (OAI) Software Alliance:
* contact@openairinterface.org
*/
/*
play_scenario_s1ap_compare_ie.c
-------------------
AUTHOR : Lionel GAUTHIER
COMPANY : EURECOM
EMAIL : Lionel.Gauthier@eurecom.fr
*/
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdarg.h>
#include <unistd.h>
#include <crypt.h>
#include <errno.h>
#include <libxml/tree.h>
#include <libxml/parser.h>
#include <libxml/xpath.h>
#include <libxml/xpathInternals.h>
#include "tree.h"
#include "queue.h"
#include "intertask_interface.h"
#include "platform_types.h"
#include "assertions.h"
#include "conversions.h"
#include "s1ap_common.h"
#include "play_scenario_s1ap_eNB_defs.h"
#include "play_scenario.h"
#include "msc.h"
//------------------------------------------------------------------------------
extern et_scenario_t *g_scenario;
extern uint32_t g_constraints;
//------------------------------------------------------------------------------
//asn_comp_rval_t * et_s1ap_ies_is_matching(const S1AP_PDU_PR present, s1ap_message * const m1, s1ap_message * const m2, const uint32_t constraints)
//{
//}
void update_xpath_node_mme_ue_s1ap_id(et_s1ap_t * const s1ap, xmlNode *node, const S1ap_MME_UE_S1AP_ID_t new_id)
{
xmlNode *cur_node = NULL;
xmlAttrPtr attr = NULL;
xmlChar *xml_char = NULL;
int size = 0;
int pos = 0;
int go_deeper_in_tree = 1;
//S1AP_INFO("%s() mme_ue_s1ap_id %u\n", __FUNCTION__, new_id);
// modify
for (cur_node = (xmlNode *)node; cur_node; cur_node = cur_node->next) {
go_deeper_in_tree = 1;
if ((!xmlStrcmp(cur_node->name, (const xmlChar *)"field"))) {
// do not get hidden fields
xml_char = xmlGetProp((xmlNode *)cur_node, (const xmlChar *)"hide");
if (NULL != xml_char) {
if ((!xmlStrcmp(xml_char, (const xmlChar *)"yes"))) {
go_deeper_in_tree = 0;
}
xmlFree(xml_char);
}
if (0 < go_deeper_in_tree) {
// first get size
xml_char = xmlGetProp((xmlNode *)cur_node, (const xmlChar *)"pos");
if (NULL != xml_char) {
pos = strtoul((const char *)xml_char, NULL, 0);
pos -= s1ap->xml_stream_pos_offset;
AssertFatal(pos >= 0, "Bad pos %d xml_stream_pos_offset %d", pos, s1ap->xml_stream_pos_offset);
xmlFree(xml_char);
xml_char = xmlGetProp((xmlNode *)cur_node, (const xmlChar *)"size");
if (NULL != xml_char) {
const xmlChar value_d[32];
const xmlChar value_h[20];
const xmlChar showname[64];
int ret = 0;
int pos2 = 0;
unsigned long int uli = 0;
char hex[3] = {0,0,0};
char *end_ptr = NULL;
size = strtoul((const char *)xml_char, NULL, 0);
xmlFree(xml_char);
// second: try to set value (always hex)
ret = snprintf((char *)value_d, 32, "%ld", new_id);
AssertFatal((ret > 0) && (ret < 32), "Could not convert int to dec str");
ret = snprintf((char *)value_h, 20, "C0%08X", new_id);
AssertFatal((ret > 0) && (ret < 20), "Could not convert int to hex str");
ret = snprintf((char *)showname, 64, "MME-UE-S1AP-ID: %d", new_id);
AssertFatal((ret > 0) && (ret < 64), "Could not convert int to dec str");
attr = xmlSetProp((xmlNode *)cur_node, (const xmlChar *)"value", value_h);
attr = xmlSetProp((xmlNode *)cur_node, (const xmlChar *)"show", value_d);
attr = xmlSetProp((xmlNode *)cur_node, (const xmlChar *)"showname", showname);
//TODO update s1ap->binary_stream @pos with new_id_hex, size
AssertFatal((pos+size) < s1ap->binary_stream_allocated_size, "Rewrite of mme_ue_s1ap_id out of bounds of binary_stream");
//avoid endianess issues
do {
hex[0] = value_h[pos2++];
hex[1] = value_h[pos2++];
hex[2] = '\0';
end_ptr = hex;
uli = strtoul(hex, &end_ptr, 16);
AssertFatal((uli != ULONG_MAX) && (end_ptr != NULL) && (*end_ptr == '\0'), "Conversion of hexstring %s failed returned %lu errno %d", hex, uli, errno);
s1ap->binary_stream[pos++] = (unsigned char)uli;
} while (pos2 < (2*5));
// update ASN1
et_decode_s1ap(s1ap);
//S1AP_INFO("Updated ASN1 for %s\n", showname);
}
}
}
}
if (0 < go_deeper_in_tree) {
update_xpath_node_mme_ue_s1ap_id(s1ap, cur_node->children, new_id);
}
}
}
/**
* update_xpath_nodes:
* @nodes: the nodes set.
* @value: the new value for the node(s)
*
* Prints the @nodes content to @output.
* From http://www.xmlsoft.org/examples/#xpath2.c
*/
void update_xpath_nodes_mme_ue_s1ap_id(et_s1ap_t * const s1ap_payload, xmlNodeSetPtr nodes, const S1ap_MME_UE_S1AP_ID_t new_id)
{
int size = 0;
int i = 0;
xmlNode *s1ap_node = NULL;
size = (nodes) ? nodes->nodeNr : 0;
//S1AP_DEBUG("%s() num nodes %u\n", __FUNCTION__, size);
/*
* NOTE: the nodes are processed in reverse order, i.e. reverse document
* order because xmlNodeSetContent can actually free up descendant
* of the node and such nodes may have been selected too ! Handling
* in reverse order ensure that descendant are accessed first, before
* they get removed. Mixing XPath and modifications on a tree must be
* done carefully !
*/
for(i = size - 1; i >= 0; i--) {
s1ap_node = nodes->nodeTab[i];
AssertFatal(NULL != s1ap_node, "One element of resultset of XPATH expression is NULL\n");
update_xpath_node_mme_ue_s1ap_id(s1ap_payload, s1ap_node, new_id);
/*
* All the elements returned by an XPath query are pointers to
* elements from the tree *except* namespace nodes where the XPath
* semantic is different from the implementation in libxml2 tree.
* As a result when a returned node set is freed when
* xmlXPathFreeObject() is called, that routine must check the
* element type. But node from the returned set may have been removed
* by xmlNodeSetContent() resulting in access to freed data.
* This can be exercised by running valgrind
* There is 2 ways around it:
* - make a copy of the pointers to the nodes from the result set
* then call xmlXPathFreeObject() and then modify the nodes
* or
* - remove the reference to the modified nodes from the node set
* as they are processed, if they are not namespace nodes.
*/
if (nodes->nodeTab[i]->type != XML_NAMESPACE_DECL) {
nodes->nodeTab[i] = NULL;
}
}
}
//------------------------------------------------------------------------------
int et_s1ap_update_mme_ue_s1ap_id(et_packet_t * const packet, const S1ap_MME_UE_S1AP_ID_t old_id, const S1ap_MME_UE_S1AP_ID_t new_id)
{
xmlChar xpath_expression[ET_XPATH_EXPRESSION_MAX_LENGTH];
int ret = 0;
xmlDocPtr doc = NULL;
xmlXPathContextPtr xpath_ctx = NULL;
xmlXPathObjectPtr xpath_obj = NULL;
//S1AP_DEBUG("%s() packet num %u original frame number %u, mme_ue_s1ap_id %u -> %u\n", __FUNCTION__, packet->packet_number, packet->original_frame_number, old_id, new_id);
ret = snprintf(xpath_expression, ET_XPATH_EXPRESSION_MAX_LENGTH, "//field[@name=\"s1ap.MME_UE_S1AP_ID\"][@show=\"%u\"]", old_id);
AssertFatal((ret > 0) && (ret < ET_XPATH_EXPRESSION_MAX_LENGTH), "Could not build XPATH expression err=%d", ret);
doc = packet->sctp_hdr.u.data_hdr.payload.doc;
// Create xpath evaluation context
xpath_ctx = xmlXPathNewContext(doc);
if(xpath_ctx == NULL) {
fprintf(stderr,"Error: unable to create new XPath context\n");
xmlFreeDoc(doc);
return(-1);
}
// Evaluate xpath expression
xpath_obj = xmlXPathEvalExpression(xpath_expression, xpath_ctx);
xmlXPathFreeContext(xpath_ctx);
AssertFatal(xpath_obj != NULL, "Unable to evaluate XPATH expression \"%s\"\n", xpath_expression);
if(xmlXPathNodeSetIsEmpty(xpath_obj->nodesetval)){
xmlXPathFreeObject(xpath_obj);
S1AP_DEBUG("%s() No match \"%s\"packet num %u original frame number %u, mme_ue_s1ap_id %u -> %u\n",
__FUNCTION__, xpath_expression, packet->packet_number, packet->original_frame_number, old_id, new_id);
return -1;
}
// update selected nodes
update_xpath_nodes_mme_ue_s1ap_id(&packet->sctp_hdr.u.data_hdr.payload, xpath_obj->nodesetval, new_id);
// Cleanup of XPath data
xmlXPathFreeObject(xpath_obj);
return 0;
}