/*

 * valid.c: a libFuzzer target to test DTD validation.

 *

 * See Copyright for the status of this software.

 */

#include <libxml/catalog.h>

#include <libxml/parser.h>

#include <libxml/tree.h>

#include <libxml/xmlerror.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

    return 0;

}

int

LLVMFuzzerTestOneInput(const char *data, size_t size) {

    xmlParserCtxtPtr ctxt;

    xmlDocPtr doc;

    const char *docBuffer, *docUrl;

    size_t failurePos, docSize;

    int opts;

    xmlFuzzDataInit(data, size);

    opts = (int) xmlFuzzReadInt(4);

    opts |= XML_PARSE_DTDVALID;

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

    xmlFuzzReadEntities();

    docBuffer = xmlFuzzMainEntity(&docSize);

    docUrl = xmlFuzzMainUrl();

    if (docBuffer == NULL)

        goto exit;

    /* Pull parser */

    xmlFuzzInjectFailure(failurePos);

    ctxt = xmlNewParserCtxt();

    if (ctxt != NULL) {

        xmlCtxtSetErrorHandler(ctxt, xmlFuzzSErrorFunc, NULL);

        xmlCtxtSetResourceLoader(ctxt, xmlFuzzResourceLoader, NULL);

        doc = xmlCtxtReadMemory(ctxt, docBuffer, docSize, docUrl, NULL, opts);

        xmlFuzzCheckFailureReport("xmlCtxtReadMemory",

                                  ctxt->errNo == XML_ERR_NO_MEMORY,

                                  ctxt->errNo == XML_IO_EIO);

        xmlFreeDoc(doc);

        xmlFreeParserCtxt(ctxt);

    }

    /* Post validation */

    xmlFuzzInjectFailure(failurePos);

    ctxt = xmlNewParserCtxt();

    if (ctxt != NULL) {

        xmlCtxtSetErrorHandler(ctxt, xmlFuzzSErrorFunc, NULL);

        xmlCtxtSetResourceLoader(ctxt, xmlFuzzResourceLoader, NULL);

        doc = xmlCtxtReadMemory(ctxt, docBuffer, docSize, docUrl, NULL,

                                opts & ~XML_PARSE_DTDVALID);

        xmlFuzzCheckFailureReport("xmlCtxtReadMemory",

                doc == NULL && ctxt->errNo == XML_ERR_NO_MEMORY,

                doc == NULL && ctxt->errNo == XML_IO_EIO);

        if (doc != NULL) {

            int valid = xmlCtxtValidateDocument(ctxt, doc);

            xmlFuzzCheckFailureReport("xmlCtxtValidateDocument",

                    !valid && ctxt->errNo == XML_ERR_NO_MEMORY,

                    !valid && ctxt->errNo == XML_IO_EIO);

        }

        xmlFreeDoc(doc);

        xmlFreeParserCtxt(ctxt);

    }

    /* Push parser */

#ifdef LIBXML_PUSH_ENABLED

    {

        static const size_t maxChunkSize = 128;

        size_t consumed, chunkSize;

        xmlFuzzInjectFailure(failurePos);

        /*

         * FIXME: xmlCreatePushParserCtxt can still report OOM errors

         * to stderr.

         */

        xmlSetGenericErrorFunc(NULL, xmlFuzzErrorFunc);

        ctxt = xmlCreatePushParserCtxt(NULL, NULL, NULL, 0, docUrl);

        xmlSetGenericErrorFunc(NULL, NULL);

        if (ctxt != NULL) {

            xmlCtxtSetErrorHandler(ctxt, xmlFuzzSErrorFunc, NULL);

            xmlCtxtSetResourceLoader(ctxt, xmlFuzzResourceLoader, NULL);

            xmlCtxtUseOptions(ctxt, opts);

            for (consumed = 0; consumed < docSize; consumed += chunkSize) {

                chunkSize = docSize - consumed;

                if (chunkSize > maxChunkSize)

                    chunkSize = maxChunkSize;

                xmlParseChunk(ctxt, docBuffer + consumed, chunkSize, 0);

            }

            xmlParseChunk(ctxt, NULL, 0, 1);

            xmlFuzzCheckFailureReport("xmlParseChunk",

                                      ctxt->errNo == XML_ERR_NO_MEMORY,

                                      ctxt->errNo == XML_IO_EIO);

            xmlFreeDoc(ctxt->myDoc);

            xmlFreeParserCtxt(ctxt);

        }

    }

#endif

exit:

    xmlFuzzInjectFailure(0);

    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 }, /* opts */

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

        { 0, 0 }

    };

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

                               LLVMFuzzerMutate);

}