qubes-installer-qubes-os/loader/telnetd.c

/*
 * telnetd.c - glue to tie telnet.c from ttywatch to the loader
 *
 * Copyright (C) 2002  Red Hat, Inc.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Author(s): Erik Troan <ewt@redhat.com>
 *            Jeremy Katz <katzj@redhat.com>
 */

#include <arpa/inet.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <newt.h>
#include <pty.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/poll.h>
#include <sys/signal.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

#include "lang.h"
#include "loader.h"
#include "log.h"
#include "modules.h"
#include "net.h"
#include "telnet.h"
#include "windows.h"

#ifndef IPPORT_TELNET
#define IPPORT_TELNET 23
#endif

/* boot flags */
extern uint64_t flags;

/* Forks, keeping the loader as our child (so we know when it dies). */
int beTelnet(void) {
    int sock;
    int conn;
    socklen_t addrLength;
    pid_t child;
    int i;
    int masterFd, ttyFd;
    struct sockaddr_in address;
    char buf[4096];
    struct pollfd fds[3];
    telnet_state ts = TS_DATA;
    char * termType;
    int height, width;
    struct winsize ws;

    if ((sock = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
        logMessage(ERROR, "socket: %s", strerror(errno));
        return -1;
    }

    address.sin_family = AF_INET;
    address.sin_port = htons(IPPORT_TELNET);
    memset(&address.sin_addr, 0, sizeof(address.sin_addr));
    addrLength = sizeof(address);

    /* Let the kernel reuse the socket address. This lets us run
       twice in a row, without waiting for the (ip, port) tuple
       to time out. Makes testing much easier*/
    conn = 1;
    setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &conn, sizeof(conn));

    bind(sock, (struct sockaddr *) &address, sizeof(address));
    listen(sock, 5);

    winStatus(45, 3, _("Telnet"), _("Waiting for telnet connection."));

    if ((conn = accept(sock, (struct sockaddr *) &address, &addrLength)) < 0) {
        newtWinMessage(_("Error"), _("OK"), "accept failed: %s",
                       strerror(errno));
        close(sock);
        return -1;
    }

    stopNewt();
    close(sock);
    telnet_negotiate(conn, &termType, &height, &width);

#ifdef DEBUG_TELNET
    printf("got term type %s\n", termType);
#endif

    masterFd = open("/dev/ptmx", O_RDWR);
    if (masterFd < 0) {
        logMessage(CRITICAL, "cannot open /dev/ptmx");
        close(conn);
        return -1;
    }

    if (height != -1 && width != -1) {
#ifdef DEBUG_TELNET
        printf("setting window size to %d x %d\n", width, height);
#endif
        ws.ws_row = height;
        ws.ws_col = width;
        ioctl(masterFd, TIOCSWINSZ, &ws);
    }


    child = fork();

    if (child) {
#ifndef DEBUG_TELNET
        startNewt();
        winStatus(45, 3, _("Telnet"), _("Running anaconda via telnet."));
#endif

        fds[0].events = POLLIN;
        fds[0].fd = masterFd;

        fds[1].events = POLLIN;
        fds[1].fd = conn;

        while ((i = poll(fds, 2, -1)) > 0) {
            if (fds[0].revents) {
                i = read(masterFd, buf, sizeof(buf));
#ifdef DEBUG_TELNET
                {
                    int j;
                    int row;

                    for (row = 0; row < (i / 12) + 1; row++) {
                        printf("wrote:");

                        for (j = (row * 12); j < i && j < ((row + 1) * 12); j++)
                            printf(" 0x%2x", (unsigned char) buf[j]);

                        printf("\nwrote:");

                        for (j = (row*12); j < i && j < ((row+1)*12); j++) {
                            if (isprint(buf[j]))
                                printf("   %c ", buf[j]);
                            else
                                printf("     ");
                        }

                        printf("\n");
                    }
                }
#endif
                /* child died */
                if (i < 0)
                    break;

                telnet_send_output(conn, buf, i);
            }

            if (fds[1].revents) {
                int ret;
                i = read(conn, buf, sizeof(buf));

                /* connection went away */
                if (!i)
                    break;

                i = telnet_process_input(&ts, buf, i);
                ret = write(masterFd, buf, i);
#ifdef DEBUG_TELNET
                {
                    int j;

                    printf("got:");
                    for (j = 0; j < i; j++)
                        printf(" 0x%x", (unsigned char) buf[j]);
                    printf("\n");
                }
#endif
            }
        }

        if (i < 0) {
            logMessage(ERROR, "poll: %s", strerror(errno));
        }

#ifndef DEBUG_TELNET
        stopNewt();
#endif

        kill(child, SIGTERM);
        close(conn);
        doExit(0);
    }

    unlockpt(masterFd);
    grantpt(masterFd);
    ttyFd = open(ptsname(masterFd), O_RDWR);
    close(masterFd);
    setsid();
    close(0);
    close(1);
    close(2);

    if (ttyFd != 0) {
        dup2(ttyFd, 0);
        close(ttyFd);
    }

    dup2(0, 1);
    dup2(0, 2);

    /* brand new tty! */
    setenv("TERM", termType, 1);

    startNewt();

    return 0;
}

void startTelnetd(struct loaderData_s * loaderData) {
    char *ipaddr = NULL;
    iface_t iface;

    iface_init_iface_t(&iface);

    if (kickstartNetworkUp(loaderData, &iface)) {
        logMessage(ERROR, "unable to bring up network");
        return;
    }

    ipaddr = iface_ip2str(iface.device, AF_INET);
    if (ipaddr == NULL) {
        logMessage(ERROR, "%s (%d): no IP address found for %s",
                   __func__, __LINE__, iface.device);
        return;
    }

    logMessage(INFO, "going to beTelnet for %s", ipaddr);
    if (!beTelnet())
        flags |= LOADER_FLAGS_TEXT | LOADER_FLAGS_NOSHELL;

    return;
}