/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright (c) 2015, Joyent, Inc.
 */

/*
 * Tests to make sure that a parent and child do not get the same arc4random
 * state across a fork from a signal handler. This source file is used to make
 * two tests. One which initializes the data in advance, one of which does not.
 */

#include <stdlib.h>
#include <sys/mman.h>
#include <assert.h>
#include <errno.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/wait.h>
#include <signal.h>
#include <strings.h>

typedef struct arc4_fork {
        uint32_t        af_parent;
        uint32_t        af_child;
        uint8_t         af_pbuf[4096];
        uint8_t         af_cbuf[4096];
} arc4_fork_t;

arc4_fork_t *fork_data;
static pid_t pid;

/*ARGSUSED*/
static void
siguser_fork(int sig, siginfo_t *sip, void *ucp)
{
        pid = fork();
}

int
main(void)
{
        int e, i, ret;
        pid_t child;
        struct sigaction sact;

        bzero(&sact, sizeof (struct sigaction));
        sact.sa_flags = SA_SIGINFO;
        sact.sa_sigaction = siguser_fork;

        (void) sigemptyset(&sact.sa_mask);
        ret = sigaction(SIGUSR1, &sact, NULL);
        assert(ret == 0);

#ifdef  ARC4_PREINIT
        (void) arc4random();
#endif

        fork_data = (arc4_fork_t *)mmap(NULL, sizeof (arc4_fork_t),
            PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
        assert(fork_data != MAP_FAILED);

        ret = raise(SIGUSR1);
        assert(ret == 0);
        assert(pid != -1);
        if (pid == 0) {
                fork_data->af_child = arc4random();
                arc4random_buf(fork_data->af_cbuf, sizeof (fork_data->af_cbuf));
                exit(0);
        }

        fork_data->af_parent = arc4random();
        arc4random_buf(fork_data->af_pbuf, sizeof (fork_data->af_pbuf));
        do {
                child = wait(&e);
        } while (child == -1 && errno == EINTR);
        assert(child == pid);

        /* Now verify our data doesn't match */
        assert(fork_data->af_parent != fork_data->af_child);

        /*
         * For the buffer here, we're mostly concerned that they aren't somehow
         * getting the same stream.
         */
        for (i = 0; i < sizeof (fork_data->af_pbuf); i++) {
                if (fork_data->af_pbuf[i] != fork_data->af_cbuf[i])
                        break;
        }
        assert(i != sizeof (fork_data->af_pbuf));

        return (0);
}