/*-
 * Copyright (c) 2009   Simon L. Nielsen <simon@FreeBSD.org>,
 *                      Bjoern A. Zeeb <bz@FreeBSD.org>
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/param.h>
#include <sys/mman.h>
#include <sys/sysctl.h>

#include <atf-c.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>

#define MAP_AT_ZERO     "security.bsd.map_at_zero"

#ifdef __LP64__
#define ALLOW_WX "kern.elf64.allow_wx"
#else
#define ALLOW_WX "kern.elf32.allow_wx"
#endif

ATF_TC_WITHOUT_HEAD(mmap__map_at_zero);
ATF_TC_BODY(mmap__map_at_zero, tc)
{
        void *p;
        size_t len;
        unsigned int i;
        int map_at_zero;
        bool allow_wx;
        int prot_flags;
        size_t pgsz = getpagesize();

        const struct {
                void    *addr;
                int     ok[2];  /* Depending on security.bsd.map_at_zero {0, !=0}. */
        } map_at_zero_tests[] = {
                { (void *)0,                    { 0, 1 } }, /* Test sysctl. */
                { (void *)1,                    { 0, 0 } },
                { (void *)(pgsz - 1),           { 0, 0 } },
                { (void *)pgsz,                 { 1, 1 } },
                { (void *)-1,                   { 0, 0 } },
                { (void *)(-pgsz),              { 0, 0 } },
                { (void *)(-1 - pgsz),          { 0, 0 } },
                { (void *)(-1 - pgsz - 1),      { 0, 0 } },
                { (void *)(0x1000 * pgsz),      { 1, 1 } },
        };

        len = sizeof(map_at_zero);
        if (sysctlbyname(MAP_AT_ZERO, &map_at_zero, &len, NULL, 0) == -1) {
                atf_tc_skip("sysctl for %s failed: %s\n", MAP_AT_ZERO,
                    strerror(errno));
                return;
        }

        len = sizeof(allow_wx);
        if (sysctlbyname(ALLOW_WX, &allow_wx, &len, NULL, 0) == -1) {
                if (errno == ENOENT) {
                        /* Allow W+X if sysctl isn't present */
                        allow_wx = true;
                } else {
                        atf_tc_skip("sysctl for %s failed: %s\n", ALLOW_WX,
                            strerror(errno));
                        return;
                }
        }

        /* Normalize to 0 or 1 for array access. */
        map_at_zero = !!map_at_zero;

        for (i = 0; i < nitems(map_at_zero_tests); i++) {
                prot_flags = PROT_READ | PROT_WRITE;
                if (allow_wx)
                        prot_flags |= PROT_EXEC;
                p = mmap((void *)map_at_zero_tests[i].addr, PAGE_SIZE,
                    prot_flags, MAP_ANON | MAP_FIXED, -1, 0);
                if (p == MAP_FAILED) {
                        ATF_CHECK_MSG(map_at_zero_tests[i].ok[map_at_zero] == 0,
                            "mmap(%p, ...) failed", map_at_zero_tests[i].addr);
                } else {
                        ATF_CHECK_MSG(map_at_zero_tests[i].ok[map_at_zero] == 1,
                            "mmap(%p, ...) succeeded: p=%p\n",
                            map_at_zero_tests[i].addr, p);
                }
        }
}

static void
checked_mmap(int prot, int flags, int fd, int error, const char *msg)
{
        void *p;
        int pagesize;

        ATF_REQUIRE((pagesize = getpagesize()) > 0);
        p = mmap(NULL, pagesize, prot, flags, fd, 0);
        if (p == MAP_FAILED) {
                if (error == 0)
                        ATF_CHECK_MSG(0, "%s failed with errno %d", msg,
                            errno);
                else
                        ATF_CHECK_EQ_MSG(error, errno,
                            "%s failed with wrong errno %d (expected %d)", msg,
                            errno, error);
        } else {
                ATF_CHECK_MSG(error == 0, "%s succeeded", msg);
                munmap(p, pagesize);
        }
}

ATF_TC_WITHOUT_HEAD(mmap__bad_arguments);
ATF_TC_BODY(mmap__bad_arguments, tc)
{
        int devstatfd, pagesize, shmfd, zerofd;

        ATF_REQUIRE((pagesize = getpagesize()) > 0);
        ATF_REQUIRE((devstatfd = open("/dev/devstat", O_RDONLY)) >= 0);
        ATF_REQUIRE((shmfd = shm_open(SHM_ANON, O_RDWR, 0644)) >= 0);
        ATF_REQUIRE(ftruncate(shmfd, pagesize) == 0);
        ATF_REQUIRE((zerofd = open("/dev/zero", O_RDONLY)) >= 0);

        /* These should work. */
        checked_mmap(PROT_READ | PROT_WRITE, MAP_ANON, -1, 0,
            "simple MAP_ANON");
        checked_mmap(PROT_READ | PROT_WRITE, MAP_SHARED, shmfd, 0,
            "simple shm fd shared");
        checked_mmap(PROT_READ | PROT_WRITE, MAP_PRIVATE, shmfd, 0,
            "simple shm fd private");
        checked_mmap(PROT_READ, MAP_SHARED, zerofd, 0,
            "simple /dev/zero shared");
        checked_mmap(PROT_READ | PROT_WRITE, MAP_PRIVATE, zerofd, 0,
            "simple /dev/zero private");
        checked_mmap(PROT_READ, MAP_SHARED, devstatfd, 0,
            "simple /dev/devstat shared");

        /* Extra PROT flags. */
        checked_mmap(PROT_READ | PROT_WRITE | 0x100000, MAP_ANON, -1, EINVAL,
            "MAP_ANON with extra PROT flags");
        checked_mmap(0xffff, MAP_SHARED, shmfd, EINVAL,
            "shm fd with garbage PROT");

        /* Undefined flag. */
        checked_mmap(PROT_READ | PROT_WRITE, MAP_ANON | MAP_RESERVED0080, -1,
            EINVAL, "Undefined flag");

        /* Both MAP_SHARED and MAP_PRIVATE */
        checked_mmap(PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE |
            MAP_SHARED, -1, EINVAL, "MAP_ANON with both SHARED and PRIVATE");
        checked_mmap(PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_SHARED, shmfd,
            EINVAL, "shm fd with both SHARED and PRIVATE");

        /* At least one of MAP_SHARED or MAP_PRIVATE without ANON */
        checked_mmap(PROT_READ | PROT_WRITE, 0, shmfd, EINVAL,
            "shm fd without sharing flag");

        /* MAP_ANON with either sharing flag (impacts fork). */
        checked_mmap(PROT_READ | PROT_WRITE, MAP_ANON | MAP_SHARED, -1, 0,
            "shared MAP_ANON");
        checked_mmap(PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0,
            "private MAP_ANON");

        /* MAP_ANON should require an fd of -1. */
        checked_mmap(PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, 0, EINVAL,
            "MAP_ANON with fd != -1");

        /* Writable MAP_SHARED should fail on read-only descriptors. */
        checked_mmap(PROT_READ | PROT_WRITE, MAP_SHARED, zerofd, EACCES,
            "MAP_SHARED of read-only /dev/zero");

        /*
         * Character devices other than /dev/zero do not support private
         * mappings.
         */
        checked_mmap(PROT_READ, MAP_PRIVATE, devstatfd, EINVAL,
            "MAP_PRIVATE of /dev/devstat");

        close(devstatfd);
        close(shmfd);
        close(zerofd);
}

ATF_TC_WITHOUT_HEAD(mmap__dev_zero_private);
ATF_TC_BODY(mmap__dev_zero_private, tc)
{
        char *p1, *p2, *p3;
        int fd, i, pagesize;

        ATF_REQUIRE((pagesize = getpagesize()) > 0);
        ATF_REQUIRE((fd = open("/dev/zero", O_RDONLY)) >= 0);

        p1 = mmap(NULL, pagesize, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
        ATF_REQUIRE(p1 != MAP_FAILED);

        p2 = mmap(NULL, pagesize, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
        ATF_REQUIRE(p2 != MAP_FAILED);

        for (i = 0; i < pagesize; i++)
                ATF_REQUIRE_EQ_MSG(0, p1[i], "byte at p1[%d] is %x", i, p1[i]);

        ATF_REQUIRE(memcmp(p1, p2, pagesize) == 0);

        p1[0] = 1;

        ATF_REQUIRE(p2[0] == 0);

        p2[0] = 2;

        ATF_REQUIRE(p1[0] == 1);

        p3 = mmap(NULL, pagesize, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
        ATF_REQUIRE(p3 != MAP_FAILED);

        ATF_REQUIRE(p3[0] == 0);

        munmap(p1, pagesize);
        munmap(p2, pagesize);
        munmap(p3, pagesize);
        close(fd);
}

ATF_TC_WITHOUT_HEAD(mmap__dev_zero_shared);
ATF_TC_BODY(mmap__dev_zero_shared, tc)
{
        char *p1, *p2, *p3;
        int fd, i, pagesize;

        ATF_REQUIRE((pagesize = getpagesize()) > 0);
        ATF_REQUIRE((fd = open("/dev/zero", O_RDWR)) >= 0);

        p1 = mmap(NULL, pagesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
        ATF_REQUIRE(p1 != MAP_FAILED);

        p2 = mmap(NULL, pagesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
        ATF_REQUIRE(p2 != MAP_FAILED);

        for (i = 0; i < pagesize; i++)
                ATF_REQUIRE_EQ_MSG(0, p1[i], "byte at p1[%d] is %x", i, p1[i]);

        ATF_REQUIRE(memcmp(p1, p2, pagesize) == 0);

        p1[0] = 1;

        ATF_REQUIRE(p2[0] == 0);

        p2[0] = 2;

        ATF_REQUIRE(p1[0] == 1);

        p3 = mmap(NULL, pagesize, PROT_READ | PROT_WRITE, MAP_SHARED, fd,
            0);
        ATF_REQUIRE(p3 != MAP_FAILED);

        ATF_REQUIRE(p3[0] == 0);

        munmap(p1, pagesize);
        munmap(p2, pagesize);
        munmap(p3, pagesize);
        close(fd);
}

ATF_TC_WITHOUT_HEAD(mmap__write_only);
ATF_TC_BODY(mmap__write_only, tc)
{
        void *p;
        int pagesize;

        ATF_REQUIRE((pagesize = getpagesize()) > 0);
        p = mmap(NULL, pagesize, PROT_WRITE, MAP_ANON, -1, 0);
        ATF_REQUIRE(p != MAP_FAILED);

        *(volatile uint32_t *)p = 0x12345678;

        munmap(p, pagesize);
}

ATF_TC_WITHOUT_HEAD(mmap__maxprot_basic);
ATF_TC_BODY(mmap__maxprot_basic, tc)
{
        void *p;
        int error, pagesize;

        ATF_REQUIRE((pagesize = getpagesize()) > 0);

        p = mmap(NULL, pagesize, PROT_READ | PROT_MAX(PROT_READ),
            MAP_ANON, -1, 0);
        ATF_REQUIRE(p != MAP_FAILED);

        error = mprotect(p, pagesize, PROT_WRITE);
        ATF_REQUIRE_ERRNO(EACCES, error == -1);
        error = mprotect(p, pagesize, PROT_READ | PROT_WRITE);
        ATF_REQUIRE_ERRNO(EACCES, error == -1);
        error = mprotect(p, pagesize, PROT_READ | PROT_EXEC);
        ATF_REQUIRE_ERRNO(EACCES, error == -1);

        ATF_REQUIRE(munmap(p, pagesize) == 0);
}

/* Make sure that PROT_MAX applies as expected to mappings of shm objects */
ATF_TC_WITHOUT_HEAD(mmap__maxprot_shm);
ATF_TC_BODY(mmap__maxprot_shm, tc)
{
        void *p;
        int error, fd, pagesize;

        ATF_REQUIRE((pagesize = getpagesize()) > 0);

        fd = shm_open(SHM_ANON, O_RDWR, 0644);
        ATF_REQUIRE(fd >= 0);

        error = ftruncate(fd, pagesize);
        ATF_REQUIRE(error == 0);

        p = mmap(NULL, pagesize, PROT_READ | PROT_MAX(PROT_READ),
            MAP_PRIVATE, fd, 0);
        ATF_REQUIRE(p != MAP_FAILED);

        error = mprotect(p, pagesize, PROT_WRITE);
        ATF_REQUIRE_ERRNO(EACCES, error == -1);
        error = mprotect(p, pagesize, PROT_READ | PROT_WRITE);
        ATF_REQUIRE_ERRNO(EACCES, error == -1);
        error = mprotect(p, pagesize, PROT_READ | PROT_EXEC);
        ATF_REQUIRE_ERRNO(EACCES, error == -1);

        ATF_REQUIRE(munmap(p, pagesize) == 0);

        /* Again, this time with a shared mapping. */
        p = mmap(NULL, pagesize, PROT_READ | PROT_MAX(PROT_READ),
            MAP_SHARED, fd, 0);
        ATF_REQUIRE(p != MAP_FAILED);

        error = mprotect(p, pagesize, PROT_WRITE);
        ATF_REQUIRE_ERRNO(EACCES, error == -1);
        error = mprotect(p, pagesize, PROT_READ | PROT_WRITE);
        ATF_REQUIRE_ERRNO(EACCES, error == -1);
        error = mprotect(p, pagesize, PROT_READ | PROT_EXEC);
        ATF_REQUIRE_ERRNO(EACCES, error == -1);

        ATF_REQUIRE(munmap(p, pagesize) == 0);

        ATF_REQUIRE(close(fd) == 0);
}

ATF_TP_ADD_TCS(tp)
{
        ATF_TP_ADD_TC(tp, mmap__map_at_zero);
        ATF_TP_ADD_TC(tp, mmap__bad_arguments);
        ATF_TP_ADD_TC(tp, mmap__dev_zero_private);
        ATF_TP_ADD_TC(tp, mmap__dev_zero_shared);
        ATF_TP_ADD_TC(tp, mmap__write_only);
        ATF_TP_ADD_TC(tp, mmap__maxprot_basic);
        ATF_TP_ADD_TC(tp, mmap__maxprot_shm);

        return (atf_no_error());
}