/*
 * -------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42 - bzerk)
 * <rdg@bzerk.org> wrote this file. As long as you retain this notice
 * you can do whatever you want with this stuff. If we meet some day,
 * and you think this stuff is worth it, you can buy me a beer in 
 * return. Ruben de Groot
 * -------------------------------------------------------------------
 */

 /* jailinit.c, RdG 2002 */

static const char copyright[] =
"Copyright (c) 2002 Ruben de Groot, BZERK.ORG.\n";

#if !defined(__FreeBSD__) || __FreeBSD__ < 4
#error This program only works on FreeBSD >= 4.x
#endif

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <limits.h>
#include <fcntl.h>
#include <kvm.h>
#include <sys/param.h>
#include <sys/sysctl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/proc.h>
#include <libutil.h>
#include <sys/user.h>

#define UP_SCRIPT      "/etc/rc"
#define DOWN_SCRIPT    "/etc/rc.shutdown"
#define SHELL_PATH     "/bin/sh"
#define SHELL          "sh"
#define JIPID          "/var/run/jailinit.pid"
#define MAX_LINE	255

FILE *jf;

void script_exec(shell, args)
    char *shell;
    char *args[];
{
    pid_t pid;
    if ((pid = fork()) == 0)
        execv(shell, args);
    else
        waitpid(pid, NULL, 0);
}

void kill_procs(sig)
    int sig;
{
    kvm_t *kd;
    struct kinfo_proc *pbase;
    struct kinfo_proc *pp;
    int nproc, i;
    kd = kvm_open(NULL, NULL, NULL, O_RDONLY, "kvm_open");
    pbase = kvm_getprocs(kd, KERN_PROC_ALL, 0, &nproc);
    for (pp = pbase, i = 0; i < nproc; pp++, i++)
#if __FreeBSD__ == 4
        if (((pp)->kp_proc.p_stat) != 0 && ((pp)->kp_proc.p_pid) != getpid() 
            && ((pp)->kp_proc.p_pid) >1)
            kill(((pp)->kp_proc.p_pid), sig);
#endif
#if __FreeBSD__ >= 5
        if ((pp->ki_stat != 0) && (pp->ki_pid != getpid())
            && (pp->ki_pid >1))
            kill(pp->ki_pid, sig);
#endif
}

void jailrc(sig)
    int sig;
{
    char *args[3];
    struct stat sb;
    signal(SIGTERM, SIG_IGN);
    signal(SIGHUP, SIG_IGN);
    if (stat(DOWN_SCRIPT, &sb) == 0)
    {
        args[0] = SHELL;
        args[1] = DOWN_SCRIPT;
        args[2] = 0;
        logwtmp("~", "shutdown", "");
        script_exec(SHELL_PATH, args);
    }
    kill_procs(SIGTERM);
    sleep(2);
    kill_procs(SIGKILL);
    if ((stat(UP_SCRIPT, &sb) == 0) && (sig == SIGHUP))
    {
        args[0] = SHELL;
        args[1] = UP_SCRIPT;
        args[2] = 0;
        logwtmp("~", "reboot", "");
        script_exec(SHELL_PATH, args);
        if ((jf = fopen(JIPID, "w")) != NULL)
            fprintf(jf, "%d\n", getpid());
	else exit(2);
        fclose(jf);
    } else {
        logwtmp("~", "halt", "");
	unlink(JIPID);
	exit(sig);
    }
    signal(SIGTERM, jailrc);
    signal(SIGHUP, jailrc);
}

int check_if_jailed(void)
{
    kvm_t *kd;
    struct kinfo_proc *pbase;
    struct kinfo_proc *pp;
    int nproc, i;
    kd = kvm_open(NULL, NULL, NULL, O_RDONLY, "kvm_open");
    pbase = kvm_getprocs(kd, KERN_PROC_ALL, 0, &nproc);
    for (pp = pbase, i = 0; i < nproc; pp++, i++)
#if __FreeBSD__ == 4
        if (((pp)->kp_proc.p_stat) != 0 && ((pp)->kp_proc.p_pid) == getpid() )
            return (int) ((pp)->kp_proc.p_prison);
#endif
#if __FreeBSD__ >= 5
        if ((pp->ki_stat != 0) && (pp->ki_pid == getpid() ))
            return ( pp->ki_flag & P_JAILED );
#endif
/* something must be terribly wrong, so we'll assume we're not in jail */
    return 0;
}

int
main(argc, argv)
    int argc;
    char *argv[];  
{
    char *args[3];
    int s;
    if (! check_if_jailed()) {
        printf("We are not in a jail!\nexiting...\n");
        exit(1);
    }
    for (s = 1; s < NSIG; s++) signal(s, SIG_IGN);
    signal(SIGTERM, jailrc);
    signal(SIGHUP, jailrc);
    daemon(0,0);
    args[0] = SHELL;
    args[1] = UP_SCRIPT;
    args[2] = 0;
    logwtmp("~", "boot", "");
    script_exec(SHELL_PATH, args);
    if ((jf = fopen(JIPID, "w")) != NULL)
        fprintf(jf, "%d\n", getpid());
    else exit(2);
    fclose(jf);
    while (1) { 
	pause();
    }
}