/* Copyright (C) 2007-2020 Open Information Security Foundation

 *

 * You can copy, redistribute or modify this Program under the terms of

 * the GNU General Public License version 2 as published by the Free

 * Software Foundation.

 *

 * 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

 * version 2 along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

 * 02110-1301, USA.

 */

/**

 * \file

 *

 * \author Victor Julien <victor@inliniac.net>

 * \author Anoop Saldanha <anoopsaldanha@gmail.com>

 *

 * Implements the priority keyword

 */

#include "suricata-common.h"

#include "detect.h"

#include "detect-parse.h"

#include "detect-priority.h"

#include "detect-engine.h"

#include "detect-engine-mpm.h"

#include "util-error.h"

#include "util-debug.h"

#include "util-unittest.h"

#define PARSE_REGEX "^\\s*(\\d+|\"\\d+\")\\s*$"

static DetectParseRegex parse_regex;

static int DetectPrioritySetup (DetectEngineCtx *, Signature *, const char *);

#ifdef UNITTESTS

static void PriorityRegisterTests(void);

#endif

/**

 * \brief Registers the handler functions for the "priority" keyword

 */

void DetectPriorityRegister (void)

{

    sigmatch_table[DETECT_PRIORITY].name = "priority";

    sigmatch_table[DETECT_PRIORITY].desc = "rules with a higher priority will be examined first";

    sigmatch_table[DETECT_PRIORITY].url = "/rules/meta.html#priority";

    sigmatch_table[DETECT_PRIORITY].Setup = DetectPrioritySetup;

#ifdef UNITTESTS

    sigmatch_table[DETECT_PRIORITY].RegisterTests = PriorityRegisterTests;

#endif

    DetectSetupParseRegexes(PARSE_REGEX, &parse_regex);

}

static int DetectPrioritySetup (DetectEngineCtx *de_ctx, Signature *s, const char *rawstr)

{

    char copy_str[128] = "";

    size_t pcre2len;

    pcre2_match_data *match = NULL;

    int ret = DetectParsePcreExec(&parse_regex, &match, rawstr, 0, 0);

    if (ret < 0) {

        SCLogError("Invalid Priority in Signature "

                   "- %s",

                rawstr);

        if (match)

            pcre2_match_data_free(match);

        return -1;

    }

    pcre2len = sizeof(copy_str);

    ret = pcre2_substring_copy_bynumber(match, 1, (PCRE2_UCHAR8 *)copy_str, &pcre2len);

    if (ret < 0) {

        SCLogError("pcre2_substring_copy_bynumber failed");

        pcre2_match_data_free(match);

        return -1;

    }

    pcre2_match_data_free(match);

    char *endptr = NULL;

    long prio = strtol(copy_str, &endptr, 10);

    if (endptr == NULL || *endptr != '\0') {

        SCLogError("Saw an invalid character as arg "

                   "to priority keyword");

        return -1;

    }

    if (s->init_data->init_flags & SIG_FLAG_INIT_PRIO_EXPLICIT) {

        SCLogWarning("duplicate priority "

                     "keyword. Using highest priority in the rule");

        s->prio = MIN(s->prio, prio);

    } else {

        s->prio = prio;

        s->init_data->init_flags |= SIG_FLAG_INIT_PRIO_EXPLICIT;

    }

    return 0;

}

/*------------------------------Unittests-------------------------------------*/

#ifdef UNITTESTS

static int DetectPriorityTest01(void)

{

    DetectEngineCtx *de_ctx = DetectEngineCtxInit();

    FAIL_IF_NULL(de_ctx);

    de_ctx->sig_list = SigInit(de_ctx, "alert tcp any any -> any any "

                               "(msg:\"Priority test\"; priority:2; sid:1;)");

    FAIL_IF_NULL(de_ctx->sig_list);

    FAIL_IF_NOT(de_ctx->sig_list->prio == 2);

    DetectEngineCtxFree(de_ctx);

    PASS;

}

static int DetectPriorityTest02(void)

{

    DetectEngineCtx *de_ctx = DetectEngineCtxInit();

    FAIL_IF_NULL(de_ctx);

    Signature *sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "

                  "(msg:\"Priority test\"; priority:1; sid:1;)");

    FAIL_IF_NULL(sig);

    FAIL_IF_NOT(sig->prio == 1);

    sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "

                  "(msg:\"Priority test\"; priority:boo; sid:2;)");

    FAIL_IF_NOT_NULL(sig);

    sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "

                  "(msg:\"Priority test\"; priority:10boo; sid:3;)");

    FAIL_IF_NOT_NULL(sig);

    sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "

                  "(msg:\"Priority test\"; priority:b10oo; sid:4;)");

    FAIL_IF_NOT_NULL(sig);

    sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "

                  "(msg:\"Priority test\"; priority:boo10; sid:5;)");

    FAIL_IF_NOT_NULL(sig);

    sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "

                  "(msg:\"Priority test\"; priority:-1; sid:6;)");

    FAIL_IF_NOT_NULL(sig);

    sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "

                  "(msg:\"Priority test\"; sid:7;)");

    FAIL_IF_NULL(sig);

    FAIL_IF_NOT(sig->prio == 3);

    sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "

                  "(msg:\"Priority test\"; priority:5; priority:4; sid:8;)");

    FAIL_IF_NULL(sig);

    FAIL_IF_NOT(sig->prio == 4);

    sig = DetectEngineAppendSig(de_ctx, "alert tcp any any -> any any "

                  "(msg:\"Priority test\"; priority:5; priority:4; "

                  "priority:1; sid:9;)");

    FAIL_IF_NULL(sig);

    FAIL_IF_NOT(sig->prio == 1);

    DetectEngineCtxFree(de_ctx);

    PASS;

}

/**

 * \brief This function registers unit tests for Classification Config API.

 */

static void PriorityRegisterTests(void)

{

    UtRegisterTest("DetectPriorityTest01", DetectPriorityTest01);

    UtRegisterTest("DetectPriorityTest02", DetectPriorityTest02);

}

#endif /* UNITTESTS */