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/*
* Dropbear SSH
*
* Copyright (c) 2002,2003 Matt Johnston
* Copyright (c) 2004 by Mihnea Stoenescu
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE. */
#include "includes.h"
#include "packet.h"
#include "buffer.h"
#include "session.h"
#include "dbutil.h"
#include "channel.h"
#include "ssh.h"
#include "runopts.h"
#include "termcodes.h"
#include "chansession.h"
static void cli_closechansess(struct Channel *channel);
static int cli_initchansess(struct Channel *channel);
static void cli_chansessreq(struct Channel *channel);
static void start_channel_request(struct Channel *channel, unsigned char *type);
static void send_chansess_pty_req(struct Channel *channel);
static void send_chansess_shell_req(struct Channel *channel);
static void cli_tty_setup();
const struct ChanType clichansess = {
0, /* sepfds */
"session", /* name */
cli_initchansess, /* inithandler */
NULL, /* checkclosehandler */
cli_chansessreq, /* reqhandler */
cli_closechansess, /* closehandler */
};
static void cli_chansessreq(struct Channel *channel) {
unsigned char* type = NULL;
int wantreply;
TRACE(("enter cli_chansessreq"))
type = buf_getstring(ses.payload, NULL);
wantreply = buf_getbool(ses.payload);
if (strcmp(type, "exit-status") == 0) {
cli_ses.retval = buf_getint(ses.payload);
TRACE(("got exit-status of '%d'", cli_ses.retval))
} else if (strcmp(type, "exit-signal") == 0) {
TRACE(("got exit-signal, ignoring it"))
} else {
TRACE(("unknown request '%s'", type))
send_msg_channel_failure(channel);
goto out;
}
out:
m_free(type);
}
/* If the main session goes, we close it up */
static void cli_closechansess(struct Channel *UNUSED(channel)) {
/* This channel hasn't gone yet, so we have > 1 */
if (ses.chancount > 1) {
dropbear_log(LOG_INFO, "Waiting for other channels to close...");
}
cli_tty_cleanup(); /* Restore tty modes etc */
}
static void start_channel_request(struct Channel *channel,
unsigned char *type) {
CHECKCLEARTOWRITE();
buf_putbyte(ses.writepayload, SSH_MSG_CHANNEL_REQUEST);
buf_putint(ses.writepayload, channel->remotechan);
buf_putstring(ses.writepayload, type, strlen(type));
}
/* Taken from OpenSSH's sshtty.c:
* RCSID("OpenBSD: sshtty.c,v 1.5 2003/09/19 17:43:35 markus Exp "); */
static void cli_tty_setup() {
struct termios tio;
TRACE(("enter cli_pty_setup"))
if (cli_ses.tty_raw_mode == 1) {
TRACE(("leave cli_tty_setup: already in raw mode!"))
return;
}
if (tcgetattr(STDIN_FILENO, &tio) == -1) {
dropbear_exit("Failed to set raw TTY mode");
}
/* make a copy */
cli_ses.saved_tio = tio;
tio.c_iflag |= IGNPAR;
tio.c_iflag &= ~(ISTRIP | INLCR | IGNCR | ICRNL | IXON | IXANY | IXOFF);
#ifdef IUCLC
tio.c_iflag &= ~IUCLC;
#endif
tio.c_lflag &= ~(ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHONL);
#ifdef IEXTEN
tio.c_lflag &= ~IEXTEN;
#endif
tio.c_oflag &= ~OPOST;
tio.c_cc[VMIN] = 1;
tio.c_cc[VTIME] = 0;
if (tcsetattr(STDIN_FILENO, TCSADRAIN, &tio) == -1) {
dropbear_exit("Failed to set raw TTY mode");
}
cli_ses.tty_raw_mode = 1;
TRACE(("leave cli_tty_setup"))
}
void cli_tty_cleanup() {
TRACE(("enter cli_tty_cleanup"))
if (cli_ses.tty_raw_mode == 0) {
TRACE(("leave cli_tty_cleanup: not in raw mode"))
return;
}
if (tcsetattr(STDIN_FILENO, TCSADRAIN, &cli_ses.saved_tio) == -1) {
dropbear_log(LOG_WARNING, "Failed restoring TTY");
} else {
cli_ses.tty_raw_mode = 0;
}
TRACE(("leave cli_tty_cleanup"))
}
static void put_termcodes() {
struct termios tio;
unsigned int sshcode;
const struct TermCode *termcode;
unsigned int value;
unsigned int mapcode;
unsigned int bufpos1, bufpos2;
TRACE(("enter put_termcodes"))
if (tcgetattr(STDIN_FILENO, &tio) == -1) {
dropbear_log(LOG_WARNING, "Failed reading termmodes");
buf_putint(ses.writepayload, 1); /* Just the terminator */
buf_putbyte(ses.writepayload, 0); /* TTY_OP_END */
return;
}
bufpos1 = ses.writepayload->pos;
buf_putint(ses.writepayload, 0); /* A placeholder for the final length */
/* As with Dropbear server, we ignore baud rates for now */
for (sshcode = 1; sshcode < MAX_TERMCODE; sshcode++) {
termcode = &termcodes[sshcode];
mapcode = termcode->mapcode;
switch (termcode->type) {
case TERMCODE_NONE:
continue;
case TERMCODE_CONTROLCHAR:
value = tio.c_cc[mapcode];
break;
case TERMCODE_INPUT:
value = tio.c_iflag & mapcode;
break;
case TERMCODE_OUTPUT:
value = tio.c_oflag & mapcode;
break;
case TERMCODE_LOCAL:
value = tio.c_lflag & mapcode;
break;
case TERMCODE_CONTROL:
value = tio.c_cflag & mapcode;
break;
default:
continue;
}
/* If we reach here, we have something to say */
buf_putbyte(ses.writepayload, sshcode);
buf_putint(ses.writepayload, value);
}
buf_putbyte(ses.writepayload, 0); /* THE END, aka TTY_OP_END */
/* Put the string length at the start of the buffer */
bufpos2 = ses.writepayload->pos;
buf_setpos(ses.writepayload, bufpos1); /* Jump back */
buf_putint(ses.writepayload, bufpos2 - bufpos1 - 4); /* len(termcodes) */
buf_setpos(ses.writepayload, bufpos2); /* Back where we were */
TRACE(("leave put_termcodes"))
}
static void put_winsize() {
struct winsize ws;
if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) < 0) {
/* Some sane defaults */
ws.ws_row = 25;
ws.ws_col = 80;
ws.ws_xpixel = 0;
ws.ws_ypixel = 0;
}
buf_putint(ses.writepayload, ws.ws_col); /* Cols */
buf_putint(ses.writepayload, ws.ws_row); /* Rows */
buf_putint(ses.writepayload, ws.ws_xpixel); /* Width */
buf_putint(ses.writepayload, ws.ws_ypixel); /* Height */
}
static void sigwinch_handler(int UNUSED(unused)) {
cli_ses.winchange = 1;
}
void cli_chansess_winchange() {
unsigned int i;
struct Channel *channel = NULL;
for (i = 0; i < ses.chansize; i++) {
channel = ses.channels[i];
if (channel != NULL && channel->type == &clichansess) {
CHECKCLEARTOWRITE();
buf_putbyte(ses.writepayload, SSH_MSG_CHANNEL_REQUEST);
buf_putint(ses.writepayload, channel->remotechan);
buf_putstring(ses.writepayload, "window-change", 13);
buf_putbyte(ses.writepayload, 0); /* FALSE says the spec */
put_winsize();
encrypt_packet();
}
}
cli_ses.winchange = 0;
}
static void send_chansess_pty_req(struct Channel *channel) {
unsigned char* term = NULL;
TRACE(("enter send_chansess_pty_req"))
start_channel_request(channel, "pty-req");
/* Don't want replies */
buf_putbyte(ses.writepayload, 0);
/* Get the terminal */
term = getenv("TERM");
if (term == NULL) {
term = "vt100"; /* Seems a safe default */
}
buf_putstring(ses.writepayload, term, strlen(term));
/* Window size */
put_winsize();
/* Terminal mode encoding */
put_termcodes();
encrypt_packet();
/* Set up a window-change handler */
if (signal(SIGWINCH, sigwinch_handler) == SIG_ERR) {
dropbear_exit("signal error");
}
TRACE(("leave send_chansess_pty_req"))
}
static void send_chansess_shell_req(struct Channel *channel) {
unsigned char* reqtype = NULL;
TRACE(("enter send_chansess_shell_req"))
if (cli_opts.cmd) {
reqtype = "exec";
} else {
reqtype = "shell";
}
start_channel_request(channel, reqtype);
/* XXX TODO */
buf_putbyte(ses.writepayload, 0); /* Don't want replies */
if (cli_opts.cmd) {
buf_putstring(ses.writepayload, cli_opts.cmd, strlen(cli_opts.cmd));
}
encrypt_packet();
TRACE(("leave send_chansess_shell_req"))
}
static int cli_initchansess(struct Channel *channel) {
channel->writefd = STDOUT_FILENO;
setnonblocking(STDOUT_FILENO);
channel->readfd = STDIN_FILENO;
setnonblocking(STDIN_FILENO);
channel->errfd = STDERR_FILENO;
setnonblocking(STDERR_FILENO);
channel->extrabuf = cbuf_new(RECV_MAXWINDOW);
if (cli_opts.wantpty) {
send_chansess_pty_req(channel);
}
send_chansess_shell_req(channel);
if (cli_opts.wantpty) {
cli_tty_setup();
}
return 0; /* Success */
}
void cli_send_chansess_request() {
TRACE(("enter cli_send_chansess_request"))
if (send_msg_channel_open_init(STDIN_FILENO, &clichansess)
== DROPBEAR_FAILURE) {
dropbear_exit("Couldn't open initial channel");
}
/* No special channel request data */
encrypt_packet();
TRACE(("leave cli_send_chansess_request"))
}
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