/*
 * main.c
 *
 * Copyright (c) 1996-1999 Whistle Communications, Inc.
 * All rights reserved.
 *
 * Subject to the following obligations and disclaimer of warranty, use and
 * redistribution of this software, in source or object code forms, with or
 * without modifications are expressly permitted by Whistle Communications;
 * provided, however, that:
 * 1. Any and all reproductions of the source or object code must include the
 *    copyright notice above and the following disclaimer of warranties; and
 * 2. No rights are granted, in any manner or form, to use Whistle
 *    Communications, Inc. trademarks, including the mark "WHISTLE
 *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
 *    such appears in the above copyright notice or in the software.
 *
 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER 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 WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * $Whistle: main.c,v 1.12 1999/11/29 19:17:46 archie Exp $
 */

#include <sys/param.h>
#include <sys/socket.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <poll.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
#ifdef EDITLINE
#include <signal.h>
#include <histedit.h>
#include <pthread.h>
#endif
#ifdef JAIL
#include <sys/jail.h>
#include <jail.h>
#endif

#include <netgraph.h>

#include "ngctl.h"

#define PROMPT                  "+ "
#define MAX_ARGS                512
#define WHITESPACE              " \t\r\n\v\f"
#define DUMP_BYTES_PER_LINE     16

/* Internal functions */
static int      ReadFile(FILE *fp);
static void     ReadCtrlSocket(void);
static void     ReadDataSocket(void);
static int      DoParseCommand(const char *line);
static int      DoCommand(int ac, char **av);
static int      DoInteractive(void);
static const    struct ngcmd *FindCommand(const char *string);
static int      MatchCommand(const struct ngcmd *cmd, const char *s);
static void     Usage(const char *msg);
static int      ReadCmd(int ac, char **av);
static int      HelpCmd(int ac, char **av);
static int      QuitCmd(int ac, char **av);
#ifdef EDITLINE
static volatile sig_atomic_t unblock;
static pthread_mutex_t  mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t   cond = PTHREAD_COND_INITIALIZER;
#endif

/* List of commands */
static const struct ngcmd *const cmds[] = {
        &config_cmd,
        &connect_cmd,
        &debug_cmd,
        &dot_cmd,
        &help_cmd,
        &list_cmd,
        &mkpeer_cmd,
        &msg_cmd,
        &name_cmd,
        &read_cmd,
        &rmhook_cmd,
        &show_cmd,
        &shutdown_cmd,
        &status_cmd,
        &types_cmd,
        &write_cmd,
        &quit_cmd,
        NULL
};

/* Commands defined in this file */
const struct ngcmd read_cmd = {
        ReadCmd,
        "read <filename>",
        "Read and execute commands from a file",
        NULL,
        { "source", "." }
};
const struct ngcmd help_cmd = {
        HelpCmd,
        "help [command]",
        "Show command summary or get more help on a specific command",
        NULL,
        { "?" }
};
const struct ngcmd quit_cmd = {
        QuitCmd,
        "quit",
        "Exit program",
        NULL,
        { "exit" }
};

/* Our control and data sockets */
int     csock, dsock;

/*
 * main()
 */
int
main(int ac, char *av[])
{
        char            name[NG_NODESIZ];
        int             interactive = isatty(0) && isatty(1);
        FILE            *fp = NULL;
#ifdef JAIL
        const char      *jail_name = NULL;
        int             jid;
#endif
        int             ch, rtn = 0;

        /* Set default node name */
        snprintf(name, sizeof(name), "ngctl%d", getpid());

        /* Parse command line */
        while ((ch = getopt(ac, av, "df:j:n:")) != -1) {
                switch (ch) {
                case 'd':
                        NgSetDebug(NgSetDebug(-1) + 1);
                        break;
                case 'f':
                        if (strcmp(optarg, "-") == 0)
                                fp = stdin;
                        else if ((fp = fopen(optarg, "r")) == NULL)
                                err(EX_NOINPUT, "%s", optarg);
                        break;
                case 'j':
#ifdef JAIL
                        jail_name = optarg;
#else
                        errx(EX_UNAVAILABLE, "not built with jail support");
#endif
                        break;
                case 'n':
                        snprintf(name, sizeof(name), "%s", optarg);
                        break;
                default:
                        Usage((char *)NULL);
                        break;
                }
        }
        ac -= optind;
        av += optind;

#ifdef JAIL
        if (jail_name != NULL) {
                if (jail_name[0] == '\0')
                        Usage("invalid jail name");

                jid = jail_getid(jail_name);

                if (jid == -1)
                        errx((errno == EPERM) ? EX_NOPERM : EX_NOHOST,
                            "%s", jail_errmsg);
                if (jail_attach(jid) != 0)
                        errx((errno == EPERM) ? EX_NOPERM : EX_OSERR,
                            "cannot attach to jail");
        }
#endif

        /* Create a new socket node */
        if (NgMkSockNode(name, &csock, &dsock) < 0)
                err(EX_OSERR, "can't create node");

        /* Do commands as requested */
        if (ac == 0) {
                if (fp != NULL) {
                        rtn = ReadFile(fp);
                } else if (interactive) {
                        rtn = DoInteractive();
                } else
                        Usage("no command specified");
        } else {
                rtn = DoCommand(ac, av);
        }

        /* Convert command return code into system exit code */
        switch (rtn) {
        case CMDRTN_OK:
        case CMDRTN_QUIT:
                rtn = 0;
                break;
        case CMDRTN_USAGE:
                rtn = EX_USAGE;
                break;
        case CMDRTN_ERROR:
                rtn = EX_OSERR;
                break;
        }
        return (rtn);
}

/*
 * Process commands from a file
 */
static int
ReadFile(FILE *fp)
{
        char *line = NULL;
        ssize_t len;
        size_t sz = 0;
        unsigned int lineno = 0;
        int rtn = CMDRTN_OK;

        while ((len = getline(&line, &sz, fp)) >= 0) {
                lineno++;
                if (*line == '#')
                        continue;
                if ((rtn = DoParseCommand(line)) != CMDRTN_OK) {
                        warnx("line %d: error in file", lineno);
                        break;
                }
        }
        if (ferror(fp))
                rtn = CMDRTN_ERROR;
        free(line);
        return (rtn);
}

#ifdef EDITLINE
/* Signal handler for Monitor() thread. */
static void
Unblock(int signal __unused)
{
        unblock = 1;
}

/*
 * Thread that monitors csock and dsock while main thread
 * can be blocked in el_gets().
 */
static void *
Monitor(void *v __unused)
{
        struct pollfd pfds[2] = {
                { .fd = csock, .events = POLLIN },
                { .fd = dsock, .events = POLLIN },
        };
        struct sigaction act;

        act.sa_handler = Unblock;
        sigemptyset(&act.sa_mask);
        act.sa_flags = 0;
        sigaction(SIGUSR1, &act, NULL);

        pthread_mutex_lock(&mutex);
        for (;;) {
                unblock = 0;
                if (poll(pfds, 2, INFTIM) <= 0) {
                        if (errno == EINTR) {
                                if (unblock == 1)
                                        pthread_cond_wait(&cond, &mutex);
                                continue;
                        }
                        err(EX_OSERR, "poll");
                }
                if (pfds[0].revents != 0)
                        ReadCtrlSocket();
                if (pfds[1].revents != 0)
                        ReadDataSocket();
        }

        return (NULL);
}

static char *
Prompt(EditLine *el __unused)
{
        return (PROMPT);
}

/*
 * Here we start a thread, that will monitor the netgraph
 * sockets and catch any unexpected messages or data on them,
 * that can arrive while user edits his/her commands.
 *
 * Whenever we expect data on netgraph sockets, we send signal
 * to monitoring thread. The signal forces it to exit select()
 * system call and sleep on condvar until we wake it. While
 * monitoring thread sleeps, we can do our work with netgraph
 * sockets.
 */
static int
DoInteractive(void)
{
        pthread_t monitor;
        EditLine *el;
        History *hist;
        HistEvent hev = { 0, "" };

        (*help_cmd.func)(0, NULL);
        pthread_create(&monitor, NULL, Monitor, NULL);
        el = el_init(getprogname(), stdin, stdout, stderr);
        if (el == NULL)
                return (CMDRTN_ERROR);
        el_set(el, EL_PROMPT, Prompt);
        el_set(el, EL_SIGNAL, 1);
        el_set(el, EL_EDITOR, "emacs");
        hist = history_init();
        if (hist == NULL)
                return (CMDRTN_ERROR);
        history(hist, &hev, H_SETSIZE, 100);
        history(hist, &hev, H_SETUNIQUE, 1);
        el_set(el, EL_HIST, history, (const char *)hist);
        el_source(el, NULL);

        for (;;) {
                const char *buf;
                int count;

                if ((buf = el_gets(el, &count)) == NULL) {
                        printf("\n");
                        break;
                }
                history(hist, &hev, H_ENTER, buf);
                pthread_kill(monitor, SIGUSR1);
                pthread_mutex_lock(&mutex);
                if (DoParseCommand(buf) == CMDRTN_QUIT) {
                        pthread_mutex_unlock(&mutex);
                        break;
                }
                pthread_cond_signal(&cond);
                pthread_mutex_unlock(&mutex);
        }

        history_end(hist);
        el_end(el);
        pthread_cancel(monitor);

        return (CMDRTN_QUIT);
}

#else /* !EDITLINE */

/*
 * Interactive mode w/o libedit functionality.
 */
static int
DoInteractive(void)
{
        struct pollfd pfds[3] = {
                { .fd = csock, .events = POLLIN },
                { .fd = dsock, .events = POLLIN },
                { .fd = STDIN_FILENO, .events = POLLIN },
        };
        char *line = NULL;
        ssize_t len;
        size_t sz = 0;

        (*help_cmd.func)(0, NULL);
        for (;;) {
                /* See if any data or control messages are arriving */
                if (poll(pfds, 2, 0) <= 0) {
                        /* Issue prompt and wait for anything to happen */
                        printf("%s", PROMPT);
                        fflush(stdout);
                        if (poll(pfds, 3, INFTIM) < 0 && errno != EINTR)
                                err(EX_OSERR, "poll");
                } else {
                        pfds[2].revents = 0;
                }

                /* If not user input, print a newline first */
                if (pfds[2].revents == 0)
                        printf("\n");

                if (pfds[0].revents != 0)
                        ReadCtrlSocket();
                if (pfds[1].revents != 0)
                        ReadDataSocket();

                /* Get any user input */
                if (pfds[2].revents != 0) {
                        if ((len = getline(&line, &sz, stdin)) <= 0) {
                                printf("\n");
                                break;
                        }
                        if (DoParseCommand(line) == CMDRTN_QUIT)
                                break;
                }
        }
        free(line);
        return (CMDRTN_QUIT);
}
#endif /* !EDITLINE */

/*
 * Read and process data on netgraph control and data sockets.
 */
static void
ReadCtrlSocket(void)
{
        MsgRead();
}

static void
ReadDataSocket(void)
{
        char hook[NG_HOOKSIZ];
        u_char *buf;
        int rl;

        /* Read packet from socket. */
        if ((rl = NgAllocRecvData(dsock, &buf, hook)) < 0)
                err(EX_OSERR, "reading hook \"%s\"", hook);
        if (rl == 0)
                errx(EX_OSERR, "EOF from hook \"%s\"?", hook);

        /* Write packet to stdout. */
        printf("Rec'd data packet on hook \"%s\":\n", hook);
        DumpAscii(buf, rl);
        free(buf);
}

/*
 * Parse a command line and execute the command
 */
static int
DoParseCommand(const char *line)
{
        char *av[MAX_ARGS];
        int ac;

        /* Parse line */
        for (ac = 0, av[0] = strtok((char *)line, WHITESPACE);
            ac < MAX_ARGS - 1 && av[ac];
            av[++ac] = strtok(NULL, WHITESPACE));

        /* Do command */
        return (DoCommand(ac, av));
}

/*
 * Execute the command
 */
static int
DoCommand(int ac, char **av)
{
        const struct ngcmd *cmd;
        int rtn;

        if (ac == 0 || *av[0] == 0)
                return (CMDRTN_OK);
        if ((cmd = FindCommand(av[0])) == NULL)
                return (CMDRTN_ERROR);
        if ((rtn = (*cmd->func)(ac, av)) == CMDRTN_USAGE)
                warnx("usage: %s", cmd->cmd);
        return (rtn);
}

/*
 * Find a command
 */
static const struct ngcmd *
FindCommand(const char *string)
{
        int k, found = -1;

        for (k = 0; cmds[k] != NULL; k++) {
                if (MatchCommand(cmds[k], string)) {
                        if (found != -1) {
                                warnx("\"%s\": ambiguous command", string);
                                return (NULL);
                        }
                        found = k;
                }
        }
        if (found == -1) {
                warnx("\"%s\": unknown command", string);
                return (NULL);
        }
        return (cmds[found]);
}

/*
 * See if string matches a prefix of "cmd" (or an alias) case insensitively
 */
static int
MatchCommand(const struct ngcmd *cmd, const char *s)
{
        int a;

        /* Try to match command, ignoring the usage stuff */
        if (strlen(s) <= strcspn(cmd->cmd, WHITESPACE)) {
                if (strncasecmp(s, cmd->cmd, strlen(s)) == 0)
                        return (1);
        }

        /* Try to match aliases */
        for (a = 0; a < MAX_CMD_ALIAS && cmd->aliases[a] != NULL; a++) {
                if (strlen(cmd->aliases[a]) >= strlen(s)) {
                        if (strncasecmp(s, cmd->aliases[a], strlen(s)) == 0)
                                return (1);
                }
        }

        /* No match */
        return (0);
}

/*
 * ReadCmd()
 */
static int
ReadCmd(int ac, char **av)
{
        FILE *fp;
        int rtn;

        /* Open file */
        switch (ac) {
        case 2:
                if ((fp = fopen(av[1], "r")) == NULL) {
                        warn("%s", av[1]);
                        return (CMDRTN_ERROR);
                }
                break;
        default:
                return (CMDRTN_USAGE);
        }

        /* Process it */
        rtn = ReadFile(fp);
        if (ferror(fp))
                warn("%s", av[1]);
        fclose(fp);
        return (rtn);
}

/*
 * HelpCmd()
 */
static int
HelpCmd(int ac, char **av)
{
        const struct ngcmd *cmd;
        const char *s;
        const int maxcol = 63;
        int a, k, len;

        switch (ac) {
        case 0:
        case 1:
                /* Show all commands */
                printf("Available commands:\n");
                for (k = 0; cmds[k] != NULL; k++) {
                        cmd = cmds[k];
                        for (s = cmd->cmd; *s != '\0' && !isspace(*s); s++)
                                /* nothing */;
                        printf("  %.*s%*s %s\n", (int)(s - cmd->cmd), cmd->cmd,
                            (int)(10 - (s - cmd->cmd)), "", cmd->desc);
                }
                return (CMDRTN_OK);
        default:
                /* Show help on a specific command */
                if ((cmd = FindCommand(av[1])) != NULL) {
                        printf("usage:    %s\n", cmd->cmd);
                        if (cmd->aliases[0] != NULL) {
                                printf("Aliases:  ");
                                for (a = 0; a < MAX_CMD_ALIAS &&
                                    cmd->aliases[a] != NULL; a++) {
                                        if (a > 0)
                                                printf(", ");
                                        printf("%s", cmd->aliases[a]);
                                }
                                printf("\n");
                        }
                        printf("Summary:  %s\n", cmd->desc);
                        if (cmd->help == NULL)
                                break;
                        printf("Description:\n");
                        for (s = cmd->help; *s != '\0'; s += len) {
                                while (isspace(*s))
                                        s++;
                                /* advance to the column limit */
                                for (len = 0; s[len] && len < maxcol; len++)
                                        /* nothing */;
                                /* back up to previous interword space */
                                while (len > 0 && s[len] && !isblank(s[len]))
                                        len--;
                                printf("  %.*s\n", len, s);
                        }
                }
        }
        return (CMDRTN_OK);
}

/*
 * QuitCmd()
 */
static int
QuitCmd(int ac __unused, char **av __unused)
{
        return (CMDRTN_QUIT);
}

/*
 * Dump data in hex and ASCII form
 */
void
DumpAscii(const u_char *buf, int len)
{
        int k, count;

        for (count = 0; count < len; count += DUMP_BYTES_PER_LINE) {
                printf("%04x:  ", count);
                for (k = 0; k < DUMP_BYTES_PER_LINE; k++) {
                        if (count + k < len) {
                                printf("%02x ", buf[count + k]);
                        } else {
                                printf("   ");
                        }
                }
                printf(" ");
                for (k = 0; k < DUMP_BYTES_PER_LINE; k++) {
                        if (count + k < len) {
                                printf("%c", isprint(buf[count + k]) ?
                                    buf[count + k] : '.');
                        } else {
                                printf(" ");
                        }
                }
                printf("\n");
        }
}

/*
 * Usage()
 */
static void
Usage(const char *msg)
{
        if (msg)
                warnx("%s", msg);
        fprintf(stderr,
                "usage: ngctl [-j jail] [-d] [-f filename] [-n nodename] "
                "[command [argument ...]]\n");
        exit(EX_USAGE);
}