/*

 * xpath.c: a libFuzzer target to test XPath and XPointer expressions.

 *

 * See Copyright for the status of this software.

 */

#include <libxml/catalog.h>

#include <libxml/parser.h>

#include <libxml/xpointer.h>

#include "fuzz.h"

int

LLVMFuzzerInitialize(int *argc ATTRIBUTE_UNUSED,

                     char ***argv ATTRIBUTE_UNUSED) {

    xmlFuzzMemSetup();

    xmlInitParser();

#ifdef LIBXML_CATALOG_ENABLED

    xmlInitializeCatalog();

    xmlCatalogSetDefaults(XML_CATA_ALLOW_NONE);

#endif

    xmlSetGenericErrorFunc(NULL, xmlFuzzErrorFunc);

    return 0;

}

int

LLVMFuzzerTestOneInput(const char *data, size_t size) {

    xmlDocPtr doc;

    const char *expr, *xml;

    size_t failurePos, exprSize, xmlSize;

    if (size > 10000)

        return(0);

    xmlFuzzDataInit(data, size);

    failurePos = xmlFuzzReadInt(4) % (size + 100);

    expr = xmlFuzzReadString(&exprSize);

    xml = xmlFuzzReadString(&xmlSize);

    /* Recovery mode allows more input to be fuzzed. */

    doc = xmlReadMemory(xml, xmlSize, NULL, NULL, XML_PARSE_RECOVER);

    if (doc != NULL) {

        xmlXPathContextPtr xpctxt;

        xmlFuzzInjectFailure(failurePos);

        xpctxt = xmlXPathNewContext(doc);

        if (xpctxt != NULL) {

            int res;

            /* Operation limit to avoid timeout */

            xpctxt->opLimit = 500000;

            res = xmlXPathContextSetCache(xpctxt, 1, 4, 0);

            xmlFuzzCheckFailureReport("xmlXPathContextSetCache", res == -1, 0);

            xmlFuzzResetFailure();

            xmlXPathFreeObject(xmlXPtrEval(BAD_CAST expr, xpctxt));

            xmlFuzzCheckFailureReport("xmlXPtrEval",

                    xpctxt->lastError.code == XML_ERR_NO_MEMORY, 0);

            xmlXPathFreeContext(xpctxt);

        }

        xmlFuzzInjectFailure(0);

        xmlFreeDoc(doc);

    }

    xmlFuzzDataCleanup();

    xmlResetLastError();

    return(0);

}

size_t

LLVMFuzzerCustomMutator(char *data, size_t size, size_t maxSize,

                        unsigned seed) {

    static const xmlFuzzChunkDesc chunks[] = {

        { 4, XML_FUZZ_PROB_ONE / 10 }, /* failurePos */

        { 0, 0 }

    };

    return xmlFuzzMutateChunks(chunks, data, size, maxSize, seed,

                               LLVMFuzzerMutate);

}