/*      $NetBSD: t_exhaust.c,v 1.14 2021/06/09 21:09:20 christos Exp $  */

/*-
 * Copyright (c) 2011 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__RCSID("$NetBSD: t_exhaust.c,v 1.14 2021/06/09 21:09:20 christos Exp $");

#include <sys/resource.h>
#include <err.h>

#ifdef TEST
# include <assert.h>
# define ATF_REQUIRE(a) assert(a)
# define ATF_REQUIRE_MSG(a, fmt, ...) \
    if (!(a)) err(EXIT_FAILURE, fmt, __VA_ARGS__)
#else
# include <atf-c.h>
#endif

#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifndef REGEX_MAXSIZE
#define REGEX_MAXSIZE   9999
#endif

#ifdef TRACE

#include <dlfcn.h>
void *
malloc(size_t l)
{
        static void *(*m)(size_t);
        static int q;
        if (m == NULL) m = dlsym(RTLD_NEXT, "malloc");
        void *p = (*m)(l);
        if (q)
                return p;
        q = 1;
        printf("%p m %zu\n", p, l);
        q = 0;
        return p;
}

void
free(void *p)
{
        static void (*f)(void *);
        if (f == NULL) f = dlsym(RTLD_NEXT, "malloc");
        printf("%p f\n", p);
        (*f)(p);
}
#endif

static char *
mkstr(const char *str, size_t len)
{
        size_t slen = strlen(str);
        char *p = malloc(slen * len + 1);
        ATF_REQUIRE_MSG(p != NULL, "slen=%zu, len=%zu", slen, len);
        for (size_t i = 0; i < len; i++)
                strcpy(&p[i * slen], str);
        return p;
}

static char *
concat(const char *d, const char *s)
{
        size_t dlen = strlen(d);
        size_t slen = strlen(s);
        char *p = malloc(dlen + slen + 1);

        ATF_REQUIRE_MSG(p != NULL, "slen=%zu, dlen=%zu", slen, dlen);
        strcpy(p, d);
        strcpy(p + dlen, s);
        return p;
}

static char *
p0(size_t len)
{
        char *d, *s1, *s2;
        s1 = mkstr("\\(", len);
        s2 = concat(s1, ")");
        free(s1);
        d = concat("(", s2);
        free(s2);
        return d;
}

static char *
p1(size_t len)
{
        char *d, *s1, *s2, *s3;
        s1 = mkstr("\\(", 60);
        s2 = mkstr("(.*)", len);
        s3 = concat(s1, s2);
        free(s2);
        free(s1);
        s1 = concat(s3, ")");
        free(s3);
        d = concat("(", s1);
        free(s1);
        return d;
}

static char *
ps(const char *m, const char *s, size_t len)
{
        char *d, *s1, *s2, *s3;
        s1 = mkstr(m, len);
        s2 = mkstr(s, len);
        s3 = concat(s1, s2);
        free(s2);
        free(s1);
        d = concat("(.?)", s3);
        free(s3);
        return d;
}

static char *
p2(size_t len)
{
        return ps("((.*){0,255}", ")", len);
}

static char *
p3(size_t len)
{
        return ps("(.\\{0,}", ")", len);
}

static char *
p4(size_t len)
{
        return ps("((.*){1,255}", ")", len);
}

static char *
p5(size_t len)
{
        return ps("(", "){1,100}", len);
}

static char *
p6(size_t len)
{
        char *d, *s1, *s2;
        s1 = mkstr("(?:(.*)|", len);
        s2 = concat(s1, "(.*)");
        free(s1);
        s1 = mkstr(")", len);
        d = concat(s2, s1);
        free(s1);
        free(s2);
        return d;
}

static const struct {
        char *(*pattern)(size_t);
        int type;
} tests[] = {
        { p0, REG_EXTENDED },
        { p1, REG_EXTENDED },
        { p2, REG_EXTENDED },
        { p3, REG_EXTENDED },
        { p4, REG_EXTENDED },
        { p5, REG_EXTENDED },
        { p6, REG_BASIC },
};

static void
run(void)
{
        regex_t re;
        int e;
        struct rlimit limit;
        char *patterns[__arraycount(tests)];

        for (size_t i = 0; i < __arraycount(patterns); i++) {
                patterns[i] = (*tests[i].pattern)(REGEX_MAXSIZE);
        }

        limit.rlim_cur = limit.rlim_max = 256 * 1024 * 1024;
        ATF_REQUIRE(setrlimit(RLIMIT_VMEM, &limit) != -1);

        for (size_t i = 0; i < __arraycount(tests); i++) {
                e = regcomp(&re, patterns[i], tests[i].type);
                if (e) {
                        char ebuf[1024];
                        (void)regerror(e, &re, ebuf, sizeof(ebuf));
                        ATF_REQUIRE_MSG(e == REG_ESPACE,
                            "regcomp returned %d (%s) for pattern %zu [%s]", e,
                            ebuf, i, patterns[i]);
                        continue;
                }
                (void)regexec(&re, "aaaaaaaaaaa", 0, NULL, 0);
                regfree(&re);
        }
        for (size_t i = 0; i < __arraycount(patterns); i++) {
                free(patterns[i]);
        }
}

#ifndef TEST

ATF_TC(regcomp_too_big);

ATF_TC_HEAD(regcomp_too_big, tc)
{

        atf_tc_set_md_var(tc, "descr", "Check that large patterns don't"
            " crash, but return a proper error code");
        // libtre needs it.
        atf_tc_set_md_var(tc, "timeout", "600");
        atf_tc_set_md_var(tc, "require.memory", "256M");
}

ATF_TC_BODY(regcomp_too_big, tc)
{
        run();
}

ATF_TP_ADD_TCS(tp)
{

        ATF_TP_ADD_TC(tp, regcomp_too_big);
        return atf_no_error();
}
#else
int
main(void)
{
        run();
        return 0;
}
#endif