/* Copyright (C) 2007-2010 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>
 *
 * Implements the nocase keyword
 */

#include "suricata-common.h"
#include "decode.h"

#include "detect.h"
#include "detect-parse.h"

#include "flow-var.h"

#include "detect-content.h"
#include "detect-uricontent.h"
#include "detect-pcre.h"
#include "detect-http-client-body.h"
#include "detect-http-cookie.h"
#include "detect-http-header.h"
#include "detect-http-method.h"
#include "detect-http-uri.h"

#include "util-debug.h"

static int DetectNocaseSetup (DetectEngineCtx *, Signature *, char *);

void DetectNocaseRegister (void) {
    sigmatch_table[DETECT_NOCASE].name = "nocase";
    sigmatch_table[DETECT_NOCASE].Match = NULL;
    sigmatch_table[DETECT_NOCASE].Setup = DetectNocaseSetup;
    sigmatch_table[DETECT_NOCASE].Free  = NULL;
    sigmatch_table[DETECT_NOCASE].RegisterTests = NULL;

    sigmatch_table[DETECT_NOCASE].flags |= SIGMATCH_NOOPT;
    sigmatch_table[DETECT_NOCASE].flags |= SIGMATCH_PAYLOAD;
}

/**
 *  \internal
 *  \brief Apply the nocase keyword to the last pattern match, either content or uricontent
 *  \param det_ctx detection engine ctx
 *  \param s signature
 *  \param nullstr should be null
 *  \retval 0 ok
 *  \retval -1 failure
 */
static int DetectNocaseSetup (DetectEngineCtx *de_ctx, Signature *s, char *nullstr)
{
    SCEnter();

    if (nullstr != NULL) {
        SCLogError(SC_ERR_INVALID_VALUE, "nocase has value");
        SCReturnInt(-1);
    }

    /* Search for the first previous SigMatch that supports nocase */
    SigMatch *pm = SigMatchGetLastSMFromLists(s, 22,
            DETECT_CONTENT, s->sm_lists_tail[DETECT_SM_LIST_PMATCH],
            DETECT_CONTENT, s->sm_lists_tail[DETECT_SM_LIST_UMATCH],
            DETECT_CONTENT, s->sm_lists_tail[DETECT_SM_LIST_HCBDMATCH],
            DETECT_CONTENT, s->sm_lists_tail[DETECT_SM_LIST_HSBDMATCH],
            DETECT_CONTENT, s->sm_lists_tail[DETECT_SM_LIST_HHDMATCH],
            DETECT_CONTENT, s->sm_lists_tail[DETECT_SM_LIST_HRHDMATCH],
            DETECT_CONTENT, s->sm_lists_tail[DETECT_SM_LIST_HMDMATCH],
            DETECT_CONTENT, s->sm_lists_tail[DETECT_SM_LIST_HRUDMATCH],
            DETECT_CONTENT, s->sm_lists_tail[DETECT_SM_LIST_HSMDMATCH],
            DETECT_AL_HTTP_STAT_CODE, s->sm_lists_tail[DETECT_SM_LIST_HSCDMATCH],
            DETECT_CONTENT, s->sm_lists_tail[DETECT_SM_LIST_HCDMATCH]);
    if (pm == NULL) {
        SCLogError(SC_ERR_NOCASE_MISSING_PATTERN, "\"nocase\" needs a preceeding "
                "content, uricontent, http_client_body, http_server_body, "
                "http_header, http_method, http_uri, http_cookie, "
                "http_raw_uri, http_stat_msg or http_stat_code option");
        SCReturnInt(-1);
    }

    DetectContentData *cd = NULL;

    switch (pm->type) {
        case DETECT_CONTENT:
        case DETECT_AL_HTTP_STAT_CODE:
            cd = (DetectContentData *)pm->ctx;
            if (cd == NULL) {
                SCLogError(SC_ERR_INVALID_ARGUMENT, "invalid argument");
                SCReturnInt(-1);
            }
            cd->flags |= DETECT_CONTENT_NOCASE;
            /* Recreate the context with nocase chars */
            BoyerMooreCtxToNocase(cd->bm_ctx, cd->content, cd->content_len);
            break;
            /* should never happen */
        default:
            SCLogError(SC_ERR_NOCASE_MISSING_PATTERN, "\"nocase\" needs a preceeding "
                    "content, uricontent, http_client_body, http_server_body, "
                    "http_header, http_method, http_uri, http_cookie or "
                    "http_raw_uri option");
            SCReturnInt(-1);
            break;
    }

    SCReturnInt(0);
}