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dropbear/cli-session.c  view on Meta::CPAN

	NULL /* Null termination */
};

void cli_connected(int result, int sock, void* userdata, const char *errstring)
{
	struct sshsession *myses = userdata;
	if (result == DROPBEAR_FAILURE) {
		dropbear_exit("Connect failed: %s", errstring);
	}
	myses->sock_in = myses->sock_out = sock;
	DEBUG1(("cli_connected"))
	ses.socket_prio = DROPBEAR_PRIO_NORMAL;
	/* switches to lowdelay */
	update_channel_prio();
}

void cli_session(int sock_in, int sock_out, struct dropbear_progress_connection *progress, pid_t proxy_cmd_pid) {

	common_session_init(sock_in, sock_out);

	if (progress) {
		connect_set_writequeue(progress, &ses.writequeue);
	}

	chaninitialise(cli_chantypes);

	/* Set up cli_ses vars */
	cli_session_init(proxy_cmd_pid);

	/* Ready to go */
	ses.init_done = 1;

	/* Exchange identification */
	send_session_identification();

	kexfirstinitialise(); /* initialise the kex state */

	send_msg_kexinit();

	session_loop(cli_sessionloop);

	/* Not reached */

}

#if DROPBEAR_KEX_FIRST_FOLLOWS
static void cli_send_kex_first_guess() {
	send_msg_kexdh_init();
}
#endif

static void cli_session_init(pid_t proxy_cmd_pid) {

	cli_ses.state = STATE_NOTHING;
	cli_ses.kex_state = KEX_NOTHING;

	cli_ses.tty_raw_mode = 0;
	cli_ses.winchange = 0;

	/* We store std{in,out,err}'s flags, so we can set them back on exit
	 * (otherwise busybox's ash isn't happy */
	cli_ses.stdincopy = dup(STDIN_FILENO);
	cli_ses.stdinflags = fcntl(STDIN_FILENO, F_GETFL, 0);
	cli_ses.stdoutcopy = dup(STDOUT_FILENO);
	cli_ses.stdoutflags = fcntl(STDOUT_FILENO, F_GETFL, 0);
	cli_ses.stderrcopy = dup(STDERR_FILENO);
	cli_ses.stderrflags = fcntl(STDERR_FILENO, F_GETFL, 0);

	cli_ses.retval = EXIT_SUCCESS; /* Assume it's clean if we don't get a
									  specific exit status */
	cli_ses.proxy_cmd_pid = proxy_cmd_pid;
	TRACE(("proxy command PID='%d'", proxy_cmd_pid));

	/* Auth */
	cli_ses.lastprivkey = NULL;
	cli_ses.lastauthtype = 0;
	cli_ses.is_trivial_auth = 1;

	/* For printing "remote host closed" for the user */
	ses.remoteclosed = cli_remoteclosed;

	ses.extra_session_cleanup = cli_session_cleanup;

	/* packet handlers */
	ses.packettypes = cli_packettypes;

	ses.isserver = 0;

#if DROPBEAR_KEX_FIRST_FOLLOWS
	ses.send_kex_first_guess = cli_send_kex_first_guess;
#endif

}

static void send_msg_service_request(const char* servicename) {

	TRACE(("enter send_msg_service_request: servicename='%s'", servicename))

	CHECKCLEARTOWRITE();

	buf_putbyte(ses.writepayload, SSH_MSG_SERVICE_REQUEST);
	buf_putstring(ses.writepayload, servicename, strlen(servicename));

	encrypt_packet();
	TRACE(("leave send_msg_service_request"))
}

static void recv_msg_service_accept(void) {
	/* do nothing, if it failed then the server MUST have disconnected */
}

/* This function drives the progress of the session - it initiates KEX,
 * service, userauth and channel requests */
static void cli_sessionloop() {

	TRACE2(("enter cli_sessionloop"))

	if (ses.lastpacket == 0) {
		TRACE2(("exit cli_sessionloop: no real packets yet"))
		return;
	}

dropbear/cli-session.c  view on Meta::CPAN

#if DROPBEAR_CLI_NETCAT
			if (cli_opts.netcat_host) {
				cli_send_netcat_request();
			} else 
#endif
			if (!cli_opts.no_cmd) {
				cli_send_chansess_request();
			}

#if DROPBEAR_CLI_LOCALTCPFWD
			setup_localtcp();
#endif
#if DROPBEAR_CLI_REMOTETCPFWD
			setup_remotetcp();
#endif

			TRACE(("leave cli_sessionloop: running"))
			cli_ses.state = SESSION_RUNNING;
			return;

		case SESSION_RUNNING:
			if (ses.chancount < 1 && !cli_opts.no_cmd) {
				cli_finished();
			}

			if (cli_ses.winchange) {
				cli_chansess_winchange();
			}
			return;

		/* XXX more here needed */


	default:
		break;
	}

	TRACE2(("leave cli_sessionloop: fell out"))

}

void kill_proxy_command(void) {
	/*
	 * Send SIGHUP to proxy command if used. We don't wait() in
	 * case it hangs and instead rely on init to reap the child
	 */
	if (cli_ses.proxy_cmd_pid > 1) {
		TRACE(("killing proxy command with PID='%d'", cli_ses.proxy_cmd_pid));
		kill(cli_ses.proxy_cmd_pid, SIGHUP);
	}
}

static void cli_session_cleanup(void) {

	if (!ses.init_done) {
		return;
	}

	kill_proxy_command();

	/* Set std{in,out,err} back to non-blocking - busybox ash dies nastily if
	 * we don't revert the flags */
	/* Ignore return value since there's nothing we can do */
	(void)fcntl(cli_ses.stdincopy, F_SETFL, cli_ses.stdinflags);
	(void)fcntl(cli_ses.stdoutcopy, F_SETFL, cli_ses.stdoutflags);
	(void)fcntl(cli_ses.stderrcopy, F_SETFL, cli_ses.stderrflags);

	/* Don't leak */
	m_close(cli_ses.stdincopy);
	m_close(cli_ses.stdoutcopy);
	m_close(cli_ses.stderrcopy);

	cli_tty_cleanup();
	if (cli_ses.server_sig_algs) {
		buf_free(cli_ses.server_sig_algs);
	}
}

static void cli_finished() {
	TRACE(("cli_finished()"))

	session_cleanup();
	fprintf(stderr, "Connection to %s@%s:%s closed.\n", cli_opts.username,
			cli_opts.remotehost, cli_opts.remoteport);
	exit(cli_ses.retval);
}


/* called when the remote side closes the connection */
static void cli_remoteclosed() {

	/* XXX TODO perhaps print a friendlier message if we get this but have
	 * already sent/received disconnect message(s) ??? */
	m_close(ses.sock_in);
	m_close(ses.sock_out);
	ses.sock_in = -1;
	ses.sock_out = -1;
	dropbear_exit("Remote closed the connection");
}

/* Operates in-place turning dirty (untrusted potentially containing control
 * characters) text into clean text. 
 * Note: this is safe only with ascii - other charsets could have problems. */
void cleantext(char* dirtytext) {

	unsigned int i, j;
	char c;

	j = 0;
	for (i = 0; dirtytext[i] != '\0'; i++) {

		c = dirtytext[i];
		/* We can ignore '\r's */
		if ( (c >= ' ' && c <= '~') || c == '\n' || c == '\t') {
			dirtytext[j] = c;
			j++;
		}
	}
	/* Null terminate */
	dirtytext[j] = '\0';
}