/*
 * Copyright (c) 2008 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * 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. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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 "config.h"

#ifndef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_PTY_H
#include <pty.h>
#endif
#ifdef HAVE_UTIL_H
#include <util.h>
#endif
#ifdef HAVE_LIBUTIL_H
#include <libutil.h>
#endif

#ifdef  STREAMSPTY
#include <stropts.h>
#endif /* STREAMPTY */

#include "roken.h"
#include <getarg.h>

struct command {
    enum { CMD_EXPECT = 0, CMD_SEND, CMD_PASSWORD } type;
    unsigned int lineno;
    char *str;
    struct command *next;
};

/*
 *
 */

static struct command *commands, **next = &commands;

static sig_atomic_t alarmset = 0;

static int timeout = 10;
static int verbose;
static int help_flag;
static int version_flag;

static int master;
static int slave;
static char line[256] = { 0 };

static void
caught_signal(int signo)
{
    alarmset = signo;
}


static void
open_pty(void)
{
#ifdef _AIX
    printf("implement open_pty\n");
    exit(77);
#endif
#if defined(HAVE_OPENPTY) || defined(__linux) || defined(__osf__) /* XXX */
    if(openpty(&master, &slave, line, 0, 0) == 0)
        return;
#endif /* HAVE_OPENPTY .... */
#ifdef STREAMSPTY
    {
        char *clone[] = {
            "/dev/ptc",
            "/dev/ptmx",
            "/dev/ptm",
            "/dev/ptym/clone",
            NULL
        };
        char **q;

        for(q = clone; *q; q++){
            master = open(*q, O_RDWR);
            if(master >= 0){
#ifdef HAVE_GRANTPT
                grantpt(master);
#endif
#ifdef HAVE_UNLOCKPT
                unlockpt(master);
#endif
                strlcpy(line, ptsname(master), sizeof(line));
                slave = open(line, O_RDWR);
                if (slave < 0)
                    errx(1, "failed to open slave when using %s", *q);
                ioctl(slave, I_PUSH, "ptem");
                ioctl(slave, I_PUSH, "ldterm");

                return;
            }
        }
    }
#endif /* STREAMSPTY */

    /* more cases, like open /dev/ptmx, etc */

    exit(77);
}

/*
 *
 */

static char *
iscmd(const char *buf, const char *s)
{
    size_t len = strlen(s);
    if (strncmp(buf, s, len) != 0)
        return NULL;
    return estrdup(buf + len);
}

static void
parse_configuration(const char *fn)
{
    struct command *c;
    char s[1024];
    char *str;
    unsigned int lineno = 0;
    FILE *cmd;

    cmd = fopen(fn, "r");
    if (cmd == NULL)
        err(1, "open: %s", fn);

    while (fgets(s, sizeof(s),  cmd) != NULL) {

        s[strcspn(s, "#\n")] = '\0';
        lineno++;

        c = calloc(1, sizeof(*c));
        if (c == NULL)
            errx(1, "malloc");

        c->lineno = lineno;
        (*next) = c;
        next = &(c->next);

        if ((str = iscmd(s, "expect ")) != NULL) {
            c->type = CMD_EXPECT;
            c->str = str;
        } else if ((str = iscmd(s, "send ")) != NULL) {
            c->type = CMD_SEND;
            c->str = str;
        } else if ((str = iscmd(s, "password ")) != NULL) {
            c->type = CMD_PASSWORD;
            c->str = str;
        } else
            errx(1, "Invalid command on line %d: %s", lineno, s);
    }

    fclose(cmd);
}


/*
 *
 */

static int
eval_parent(pid_t pid)
{
    struct command *c;
    char in;
    size_t len = 0;
    ssize_t sret;

    for (c = commands; c != NULL; c = c->next) {
        switch(c->type) {
        case CMD_EXPECT:
            if (verbose)
                printf("[expecting %s]", c->str);
            len = 0;
            alarm(timeout);
            while((sret = read(master, &in, sizeof(in))) > 0) {
                alarm(timeout);
                printf("%c", in);
                if (c->str[len] != in) {
                    len = 0;
                    continue;
                }
                len++;
                if (c->str[len] == '\0')
                    break;
            }
            alarm(0);
            if (alarmset == SIGALRM)
                errx(1, "timeout waiting for %s (line %u)",
                     c->str, c->lineno);
            else if (alarmset)
                errx(1, "got a signal %d waiting for %s (line %u)",
                     alarmset, c->str, c->lineno);
            if (sret <= 0)
                errx(1, "end command while waiting for %s (line %u)",
                     c->str, c->lineno);
            break;
        case CMD_SEND:
        case CMD_PASSWORD: {
            size_t i = 0;
            const char *msg = (c->type == CMD_PASSWORD) ? "****" : c->str;

            if (verbose)
                printf("[send %s]", msg);

            len = strlen(c->str);

            while (i < len) {
                if (c->str[i] == '\\' && i < len - 1) {
                    char ctrl;
                    i++;
                    switch(c->str[i]) {
                    case 'n': ctrl = '\n'; break;
                    case 'r': ctrl = '\r'; break;
                    case 't': ctrl = '\t'; break;
                    default:
                        errx(1, "unknown control char %c (line %u)",
                             c->str[i], c->lineno);
                    }
                    if (net_write(master, &ctrl, 1) != 1)
                        errx(1, "command refused input (line %u)", c->lineno);
                } else {
                    if (net_write(master, &c->str[i], 1) != 1)
                        errx(1, "command refused input (line %u)", c->lineno);
                }
                i++;
            }
            break;
        }
        default:
            abort();
        }
    }
    while(read(master, &in, sizeof(in)) > 0)
        printf("%c", in);

    if (verbose)
        printf("[end of program]\n");

    /*
     * Fetch status from child
     */
    {
        int ret, status;

        ret = waitpid(pid, &status, 0);
        if (ret == -1)
            err(1, "waitpid");
        if (WIFEXITED(status) && WEXITSTATUS(status))
            return WEXITSTATUS(status);
        else if (WIFSIGNALED(status)) {
            printf("killed by signal: %d\n", WTERMSIG(status));
            return 1;
        }
    }
    return 0;
}

/*
 *
 */

static struct getargs args[] = {
    { "timeout",        't', arg_integer, &timeout, "timout", "seconds" },
    { "verbose",        'v', arg_counter, &verbose, "verbose debugging" },
    { "version",        0, arg_flag,    &version_flag, "print version" },
    { "help",           0, arg_flag,    &help_flag, NULL }
};

static void
usage(int ret)
{
    arg_printusage (args, sizeof(args)/sizeof(*args), NULL, "infile command..");
    exit (ret);
}

int
main(int argc, char **argv)
{
    int optidx = 0;
    pid_t pid;

    setprogname(argv[0]);

    if(getarg(args, sizeof(args) / sizeof(args[0]), argc, argv, &optidx))
        usage(1);

    if (help_flag)
        usage (0);

    if (version_flag) {
        fprintf (stderr, "%s from %s-%s\n", getprogname(), PACKAGE, VERSION);
        return 0;
    }

    argv += optidx;
    argc -= optidx;

    if (argc < 2)
        usage(1);

    parse_configuration(argv[0]);

    argv += 1;

    open_pty();

    pid = fork();
    switch (pid) {
    case -1:
        err(1, "Failed to fork");
    case 0:

        if(setsid()<0)
            err(1, "setsid");

        dup2(slave, STDIN_FILENO);
        dup2(slave, STDOUT_FILENO);
        dup2(slave, STDERR_FILENO);
        closefrom(STDERR_FILENO + 1);

        execvp(argv[0], argv); /* add NULL to end of array ? */
        err(1, "Failed to exec: %s", argv[0]);
    default:
        close(slave);
        {
            struct sigaction sa;

            sa.sa_handler = caught_signal;
            sa.sa_flags = 0;
            sigemptyset (&sa.sa_mask);

            sigaction(SIGALRM, &sa, NULL);
        }

        return eval_parent(pid);
    }
}