suricata/src/detect-within.c

/* WITHIN part of the detection engine. */

#include "decode.h"
#include "detect.h"
#include "flow-var.h"

#include <pcre.h>
#include "detect-content.h"
#include "detect-uricontent.h"
#include "detect-pcre.h"

int DetectWithinSetup (Signature *s, SigMatch *m, char *withinstr);

void DetectWithinRegister (void) {
    sigmatch_table[DETECT_WITHIN].name = "within";
    sigmatch_table[DETECT_WITHIN].Match = NULL;
    sigmatch_table[DETECT_WITHIN].Setup = DetectWithinSetup;
    sigmatch_table[DETECT_WITHIN].Free  = NULL;
    sigmatch_table[DETECT_WITHIN].RegisterTests = NULL;
}

int DetectWithinSetup (Signature *s, SigMatch *m, char *withinstr)
{
    char *str = withinstr;
    char dubbed = 0;

    //printf("DetectWithinSetup: s->match:%p,m:%p,withinstr:\'%s\'\n", s->match, m, withinstr);

    /* strip "'s */
    if (withinstr[0] == '\"' && withinstr[strlen(withinstr)-1] == '\"') {
        str = strdup(withinstr+1);
        str[strlen(withinstr)-2] = '\0';
        dubbed = 1;
    }

    SigMatch *pm = m;
    if (pm != NULL) {
        if (pm->type == DETECT_PCRE) {
            DetectPcreData *pe = (DetectPcreData *)pm->ctx;

            pe->within = strtol(str, NULL, 10);
            pe->flags |= DETECT_PCRE_WITHIN;

            //printf("DetectWithinSetup: set within %d for previous pcre\n", pe->within);
        } else if (pm->type == DETECT_CONTENT) {
            DetectContentData *cd = (DetectContentData *)pm->ctx;

            cd->within = strtol(str, NULL, 10);
            cd->flags |= DETECT_CONTENT_WITHIN;

            //printf("DetectWithinSetup: set within %d for previous content\n", cd->within);
        } else if (pm->type == DETECT_URICONTENT) {
            DetectUricontentData *ud = (DetectUricontentData *)pm->ctx;

            ud->within = strtol(str, NULL, 10);
            ud->flags |= DETECT_URICONTENT_WITHIN;

            //printf("DetectWithinSetup: set within %d for previous content\n", cd->within);
        } else {
            printf("DetectWithinSetup: Unknown previous keyword!\n");
        }
    } else {
        printf("DetectWithinSetup: No previous match!\n");
    }
    pm = m->prev;
    if (pm != NULL) {
        if (pm->type == DETECT_PCRE) {
            DetectPcreData *pe = (DetectPcreData *)pm->ctx;
            pe->flags |= DETECT_PCRE_WITHIN_NEXT;
        } else if (pm->type == DETECT_CONTENT) {
            DetectContentData *cd = (DetectContentData *)pm->ctx;
            cd->flags |= DETECT_CONTENT_WITHIN_NEXT;
        } else if (pm->type == DETECT_URICONTENT) {
            DetectUricontentData *ud = (DetectUricontentData *)pm->ctx;
            ud->flags |= DETECT_URICONTENT_WITHIN_NEXT;
        } else {
            printf("DetectWithinSetup: Unknown previous-previous keyword!\n");
        }
    } else {
        printf("DetectWithinSetup: No previous-previous match!\n");
    }

    if (dubbed) free(str);
    return 0;
}