Revert part of 180714 - the intent was to flatten dist, not to nuke it.

1 files changed, 2047 insertions, 0 deletions

diff --git a/crypto/openssh/clientloop.c b/crypto/openssh/clientloop.c
new file mode 100644
index 0000000..4c51081
--- /dev/null
+++ b/crypto/openssh/clientloop.c
@@ -0,0 +1,2047 @@
+/* $OpenBSD: clientloop.c,v 1.176 2006/10/11 12:38:03 markus Exp $ */
+/*
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ *                    All rights reserved
+ * The main loop for the interactive session (client side).
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose.  Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ *
+ *
+ * Copyright (c) 1999 Theo de Raadt.  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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+ *
+ *
+ * SSH2 support added by Markus Friedl.
+ * Copyright (c) 1999, 2000, 2001 Markus Friedl.  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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 "includes.h"
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/param.h>
+#ifdef HAVE_SYS_STAT_H
+# include <sys/stat.h>
+#endif
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+#include <sys/socket.h>
+
+#include <ctype.h>
+#include <errno.h>
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
+#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <pwd.h>
+#include <unistd.h>
+
+#include "xmalloc.h"
+#include "ssh.h"
+#include "ssh1.h"
+#include "ssh2.h"
+#include "packet.h"
+#include "buffer.h"
+#include "compat.h"
+#include "channels.h"
+#include "dispatch.h"
+#include "key.h"
+#include "cipher.h"
+#include "kex.h"
+#include "log.h"
+#include "readconf.h"
+#include "clientloop.h"
+#include "sshconnect.h"
+#include "authfd.h"
+#include "atomicio.h"
+#include "sshpty.h"
+#include "misc.h"
+#include "monitor_fdpass.h"
+#include "match.h"
+#include "msg.h"
+
+/* import options */
+extern Options options;
+
+/* Flag indicating that stdin should be redirected from /dev/null. */
+extern int stdin_null_flag;
+
+/* Flag indicating that no shell has been requested */
+extern int no_shell_flag;
+
+/* Control socket */
+extern int control_fd;
+
+/*
+ * Name of the host we are connecting to.  This is the name given on the
+ * command line, or the HostName specified for the user-supplied name in a
+ * configuration file.
+ */
+extern char *host;
+
+/*
+ * Flag to indicate that we have received a window change signal which has
+ * not yet been processed.  This will cause a message indicating the new
+ * window size to be sent to the server a little later.  This is volatile
+ * because this is updated in a signal handler.
+ */
+static volatile sig_atomic_t received_window_change_signal = 0;
+static volatile sig_atomic_t received_signal = 0;
+
+/* Flag indicating whether the user's terminal is in non-blocking mode. */
+static int in_non_blocking_mode = 0;
+
+/* Common data for the client loop code. */
+static volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
+static int escape_char;		/* Escape character. */
+static int escape_pending;	/* Last character was the escape character */
+static int last_was_cr;		/* Last character was a newline. */
+static int exit_status;		/* Used to store the exit status of the command. */
+static int stdin_eof;		/* EOF has been encountered on standard error. */
+static Buffer stdin_buffer;	/* Buffer for stdin data. */
+static Buffer stdout_buffer;	/* Buffer for stdout data. */
+static Buffer stderr_buffer;	/* Buffer for stderr data. */
+static u_long stdin_bytes, stdout_bytes, stderr_bytes;
+static u_int buffer_high;/* Soft max buffer size. */
+static int connection_in;	/* Connection to server (input). */
+static int connection_out;	/* Connection to server (output). */
+static int need_rekeying;	/* Set to non-zero if rekeying is requested. */
+static int session_closed = 0;	/* In SSH2: login session closed. */
+static int server_alive_timeouts = 0;
+
+static void client_init_dispatch(void);
+int	session_ident = -1;
+
+struct confirm_ctx {
+	int want_tty;
+	int want_subsys;
+	int want_x_fwd;
+	int want_agent_fwd;
+	Buffer cmd;
+	char *term;
+	struct termios tio;
+	char **env;
+};
+
+/*XXX*/
+extern Kex *xxx_kex;
+
+void ssh_process_session2_setup(int, int, int, Buffer *);
+
+/* Restores stdin to blocking mode. */
+
+static void
+leave_non_blocking(void)
+{
+	if (in_non_blocking_mode) {
+		unset_nonblock(fileno(stdin));
+		in_non_blocking_mode = 0;
+	}
+}
+
+/* Puts stdin terminal in non-blocking mode. */
+
+static void
+enter_non_blocking(void)
+{
+	in_non_blocking_mode = 1;
+	set_nonblock(fileno(stdin));
+}
+
+/*
+ * Signal handler for the window change signal (SIGWINCH).  This just sets a
+ * flag indicating that the window has changed.
+ */
+/*ARGSUSED */
+static void
+window_change_handler(int sig)
+{
+	received_window_change_signal = 1;
+	signal(SIGWINCH, window_change_handler);
+}
+
+/*
+ * Signal handler for signals that cause the program to terminate.  These
+ * signals must be trapped to restore terminal modes.
+ */
+/*ARGSUSED */
+static void
+signal_handler(int sig)
+{
+	received_signal = sig;
+	quit_pending = 1;
+}
+
+/*
+ * Returns current time in seconds from Jan 1, 1970 with the maximum
+ * available resolution.
+ */
+
+static double
+get_current_time(void)
+{
+	struct timeval tv;
+	gettimeofday(&tv, NULL);
+	return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
+}
+
+#define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
+void
+client_x11_get_proto(const char *display, const char *xauth_path,
+    u_int trusted, char **_proto, char **_data)
+{
+	char cmd[1024];
+	char line[512];
+	char xdisplay[512];
+	static char proto[512], data[512];
+	FILE *f;
+	int got_data = 0, generated = 0, do_unlink = 0, i;
+	char *xauthdir, *xauthfile;
+	struct stat st;
+
+	xauthdir = xauthfile = NULL;
+	*_proto = proto;
+	*_data = data;
+	proto[0] = data[0] = '\0';
+
+	if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
+		debug("No xauth program.");
+	} else {
+		if (display == NULL) {
+			debug("x11_get_proto: DISPLAY not set");
+			return;
+		}
+		/*
+		 * Handle FamilyLocal case where $DISPLAY does
+		 * not match an authorization entry.  For this we
+		 * just try "xauth list unix:displaynum.screennum".
+		 * XXX: "localhost" match to determine FamilyLocal
+		 *      is not perfect.
+		 */
+		if (strncmp(display, "localhost:", 10) == 0) {
+			snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
+			    display + 10);
+			display = xdisplay;
+		}
+		if (trusted == 0) {
+			xauthdir = xmalloc(MAXPATHLEN);
+			xauthfile = xmalloc(MAXPATHLEN);
+			strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
+			if (mkdtemp(xauthdir) != NULL) {
+				do_unlink = 1;
+				snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
+				    xauthdir);
+				snprintf(cmd, sizeof(cmd),
+				    "%s -f %s generate %s " SSH_X11_PROTO
+				    " untrusted timeout 1200 2>" _PATH_DEVNULL,
+				    xauth_path, xauthfile, display);
+				debug2("x11_get_proto: %s", cmd);
+				if (system(cmd) == 0)
+					generated = 1;
+			}
+		}
+		snprintf(cmd, sizeof(cmd),
+		    "%s %s%s list %s 2>" _PATH_DEVNULL,
+		    xauth_path,
+		    generated ? "-f " : "" ,
+		    generated ? xauthfile : "",
+		    display);
+		debug2("x11_get_proto: %s", cmd);
+		f = popen(cmd, "r");
+		if (f && fgets(line, sizeof(line), f) &&
+		    sscanf(line, "%*s %511s %511s", proto, data) == 2)
+			got_data = 1;
+		if (f)
+			pclose(f);
+	}
+
+	if (do_unlink) {
+		unlink(xauthfile);
+		rmdir(xauthdir);
+	}
+	if (xauthdir)
+		xfree(xauthdir);
+	if (xauthfile)
+		xfree(xauthfile);
+
+	/*
+	 * If we didn't get authentication data, just make up some
+	 * data.  The forwarding code will check the validity of the
+	 * response anyway, and substitute this data.  The X11
+	 * server, however, will ignore this fake data and use
+	 * whatever authentication mechanisms it was using otherwise
+	 * for the local connection.
+	 */
+	if (!got_data) {
+		u_int32_t rnd = 0;
+
+		logit("Warning: No xauth data; "
+		    "using fake authentication data for X11 forwarding.");
+		strlcpy(proto, SSH_X11_PROTO, sizeof proto);
+		for (i = 0; i < 16; i++) {
+			if (i % 4 == 0)
+				rnd = arc4random();
+			snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
+			    rnd & 0xff);
+			rnd >>= 8;
+		}
+	}
+}
+
+/*
+ * This is called when the interactive is entered.  This checks if there is
+ * an EOF coming on stdin.  We must check this explicitly, as select() does
+ * not appear to wake up when redirecting from /dev/null.
+ */
+
+static void
+client_check_initial_eof_on_stdin(void)
+{
+	int len;
+	char buf[1];
+
+	/*
+	 * If standard input is to be "redirected from /dev/null", we simply
+	 * mark that we have seen an EOF and send an EOF message to the
+	 * server. Otherwise, we try to read a single character; it appears
+	 * that for some files, such /dev/null, select() never wakes up for
+	 * read for this descriptor, which means that we never get EOF.  This
+	 * way we will get the EOF if stdin comes from /dev/null or similar.
+	 */
+	if (stdin_null_flag) {
+		/* Fake EOF on stdin. */
+		debug("Sending eof.");
+		stdin_eof = 1;
+		packet_start(SSH_CMSG_EOF);
+		packet_send();
+	} else {
+		enter_non_blocking();
+
+		/* Check for immediate EOF on stdin. */
+		len = read(fileno(stdin), buf, 1);
+		if (len == 0) {
+			/* EOF.  Record that we have seen it and send EOF to server. */
+			debug("Sending eof.");
+			stdin_eof = 1;
+			packet_start(SSH_CMSG_EOF);
+			packet_send();
+		} else if (len > 0) {
+			/*
+			 * Got data.  We must store the data in the buffer,
+			 * and also process it as an escape character if
+			 * appropriate.
+			 */
+			if ((u_char) buf[0] == escape_char)
+				escape_pending = 1;
+			else
+				buffer_append(&stdin_buffer, buf, 1);
+		}
+		leave_non_blocking();
+	}
+}
+
+
+/*
+ * Make packets from buffered stdin data, and buffer them for sending to the
+ * connection.
+ */
+
+static void
+client_make_packets_from_stdin_data(void)
+{
+	u_int len;
+
+	/* Send buffered stdin data to the server. */
+	while (buffer_len(&stdin_buffer) > 0 &&
+	    packet_not_very_much_data_to_write()) {
+		len = buffer_len(&stdin_buffer);
+		/* Keep the packets at reasonable size. */
+		if (len > packet_get_maxsize())
+			len = packet_get_maxsize();
+		packet_start(SSH_CMSG_STDIN_DATA);
+		packet_put_string(buffer_ptr(&stdin_buffer), len);
+		packet_send();
+		buffer_consume(&stdin_buffer, len);
+		stdin_bytes += len;
+		/* If we have a pending EOF, send it now. */
+		if (stdin_eof && buffer_len(&stdin_buffer) == 0) {
+			packet_start(SSH_CMSG_EOF);
+			packet_send();
+		}
+	}
+}
+
+/*
+ * Checks if the client window has changed, and sends a packet about it to
+ * the server if so.  The actual change is detected elsewhere (by a software
+ * interrupt on Unix); this just checks the flag and sends a message if
+ * appropriate.
+ */
+
+static void
+client_check_window_change(void)
+{
+	struct winsize ws;
+
+	if (! received_window_change_signal)
+		return;
+	/** XXX race */
+	received_window_change_signal = 0;
+
+	debug2("client_check_window_change: changed");
+
+	if (compat20) {
+		channel_send_window_changes();
+	} else {
+		if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
+			return;
+		packet_start(SSH_CMSG_WINDOW_SIZE);
+		packet_put_int((u_int)ws.ws_row);
+		packet_put_int((u_int)ws.ws_col);
+		packet_put_int((u_int)ws.ws_xpixel);
+		packet_put_int((u_int)ws.ws_ypixel);
+		packet_send();
+	}
+}
+
+static void
+client_global_request_reply(int type, u_int32_t seq, void *ctxt)
+{
+	server_alive_timeouts = 0;
+	client_global_request_reply_fwd(type, seq, ctxt);
+}
+
+static void
+server_alive_check(void)
+{
+	if (++server_alive_timeouts > options.server_alive_count_max) {
+		logit("Timeout, server not responding.");
+		cleanup_exit(255);
+	}
+	packet_start(SSH2_MSG_GLOBAL_REQUEST);
+	packet_put_cstring("keepalive@openssh.com");
+	packet_put_char(1);     /* boolean: want reply */
+	packet_send();
+}
+
+/*
+ * Waits until the client can do something (some data becomes available on
+ * one of the file descriptors).
+ */
+static void
+client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
+    int *maxfdp, u_int *nallocp, int rekeying)
+{
+	struct timeval tv, *tvp;
+	int ret;
+
+	/* Add any selections by the channel mechanism. */
+	channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, rekeying);
+
+	if (!compat20) {
+		/* Read from the connection, unless our buffers are full. */
+		if (buffer_len(&stdout_buffer) < buffer_high &&
+		    buffer_len(&stderr_buffer) < buffer_high &&
+		    channel_not_very_much_buffered_data())
+			FD_SET(connection_in, *readsetp);
+		/*
+		 * Read from stdin, unless we have seen EOF or have very much
+		 * buffered data to send to the server.
+		 */
+		if (!stdin_eof && packet_not_very_much_data_to_write())
+			FD_SET(fileno(stdin), *readsetp);
+
+		/* Select stdout/stderr if have data in buffer. */
+		if (buffer_len(&stdout_buffer) > 0)
+			FD_SET(fileno(stdout), *writesetp);
+		if (buffer_len(&stderr_buffer) > 0)
+			FD_SET(fileno(stderr), *writesetp);
+	} else {
+		/* channel_prepare_select could have closed the last channel */
+		if (session_closed && !channel_still_open() &&
+		    !packet_have_data_to_write()) {
+			/* clear mask since we did not call select() */
+			memset(*readsetp, 0, *nallocp);
+			memset(*writesetp, 0, *nallocp);
+			return;
+		} else {
+			FD_SET(connection_in, *readsetp);
+		}
+	}
+
+	/* Select server connection if have data to write to the server. */
+	if (packet_have_data_to_write())
+		FD_SET(connection_out, *writesetp);
+
+	if (control_fd != -1)
+		FD_SET(control_fd, *readsetp);
+
+	/*
+	 * Wait for something to happen.  This will suspend the process until
+	 * some selected descriptor can be read, written, or has some other
+	 * event pending.
+	 */
+
+	if (options.server_alive_interval == 0 || !compat20)
+		tvp = NULL;
+	else {
+		tv.tv_sec = options.server_alive_interval;
+		tv.tv_usec = 0;
+		tvp = &tv;
+	}
+	ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
+	if (ret < 0) {
+		char buf[100];
+
+		/*
+		 * We have to clear the select masks, because we return.
+		 * We have to return, because the mainloop checks for the flags
+		 * set by the signal handlers.
+		 */
+		memset(*readsetp, 0, *nallocp);
+		memset(*writesetp, 0, *nallocp);
+
+		if (errno == EINTR)
+			return;
+		/* Note: we might still have data in the buffers. */
+		snprintf(buf, sizeof buf, "select: %s\r\n", strerror(errno));
+		buffer_append(&stderr_buffer, buf, strlen(buf));
+		quit_pending = 1;
+	} else if (ret == 0)
+		server_alive_check();
+}
+
+static void
+client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
+{
+	/* Flush stdout and stderr buffers. */
+	if (buffer_len(bout) > 0)
+		atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
+	if (buffer_len(berr) > 0)
+		atomicio(vwrite, fileno(stderr), buffer_ptr(berr), buffer_len(berr));
+
+	leave_raw_mode();
+
+	/*
+	 * Free (and clear) the buffer to reduce the amount of data that gets
+	 * written to swap.
+	 */
+	buffer_free(bin);
+	buffer_free(bout);
+	buffer_free(berr);
+
+	/* Send the suspend signal to the program itself. */
+	kill(getpid(), SIGTSTP);
+
+	/* Reset window sizes in case they have changed */
+	received_window_change_signal = 1;
+
+	/* OK, we have been continued by the user. Reinitialize buffers. */
+	buffer_init(bin);
+	buffer_init(bout);
+	buffer_init(berr);
+
+	enter_raw_mode();
+}
+
+static void
+client_process_net_input(fd_set *readset)
+{
+	int len;
+	char buf[8192];
+
+	/*
+	 * Read input from the server, and add any such data to the buffer of
+	 * the packet subsystem.
+	 */
+	if (FD_ISSET(connection_in, readset)) {
+		/* Read as much as possible. */
+		len = read(connection_in, buf, sizeof(buf));
+		if (len == 0) {
+			/* Received EOF.  The remote host has closed the connection. */
+			snprintf(buf, sizeof buf, "Connection to %.300s closed by remote host.\r\n",
+				 host);
+			buffer_append(&stderr_buffer, buf, strlen(buf));
+			quit_pending = 1;
+			return;
+		}
+		/*
+		 * There is a kernel bug on Solaris that causes select to
+		 * sometimes wake up even though there is no data available.
+		 */
+		if (len < 0 && (errno == EAGAIN || errno == EINTR))
+			len = 0;
+
+		if (len < 0) {
+			/* An error has encountered.  Perhaps there is a network problem. */
+			snprintf(buf, sizeof buf, "Read from remote host %.300s: %.100s\r\n",
+				 host, strerror(errno));
+			buffer_append(&stderr_buffer, buf, strlen(buf));
+			quit_pending = 1;
+			return;
+		}
+		packet_process_incoming(buf, len);
+	}
+}
+
+static void
+client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
+{
+	int id;
+	Channel *c;
+
+	id = packet_get_int();
+	packet_check_eom();
+
+	if ((c = channel_lookup(id)) == NULL) {
+		error("%s: no channel for id %d", __func__, id);
+		return;
+	}
+
+	if (type == SSH2_MSG_CHANNEL_SUCCESS)
+		debug2("Request suceeded on channel %d", id);
+	else if (type == SSH2_MSG_CHANNEL_FAILURE) {
+		error("Request failed on channel %d", id);
+		channel_free(c);
+	}
+}
+
+static void
+client_extra_session2_setup(int id, void *arg)
+{
+	struct confirm_ctx *cctx = arg;
+	const char *display;
+	Channel *c;
+	int i;
+
+	if (cctx == NULL)
+		fatal("%s: cctx == NULL", __func__);
+	if ((c = channel_lookup(id)) == NULL)
+		fatal("%s: no channel for id %d", __func__, id);
+
+	display = getenv("DISPLAY");
+	if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
+		char *proto, *data;
+		/* Get reasonable local authentication information. */
+		client_x11_get_proto(display, options.xauth_location,
+		    options.forward_x11_trusted, &proto, &data);
+		/* Request forwarding with authentication spoofing. */
+		debug("Requesting X11 forwarding with authentication spoofing.");
+		x11_request_forwarding_with_spoofing(id, display, proto, data);
+		/* XXX wait for reply */
+	}
+
+	if (cctx->want_agent_fwd && options.forward_agent) {
+		debug("Requesting authentication agent forwarding.");
+		channel_request_start(id, "auth-agent-req@openssh.com", 0);
+		packet_send();
+	}
+
+	client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
+	    cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env,
+	    client_subsystem_reply);
+
+	c->confirm_ctx = NULL;
+	buffer_free(&cctx->cmd);
+	xfree(cctx->term);
+	if (cctx->env != NULL) {
+		for (i = 0; cctx->env[i] != NULL; i++)
+			xfree(cctx->env[i]);
+		xfree(cctx->env);
+	}
+	xfree(cctx);
+}
+
+static void
+client_process_control(fd_set *readset)
+{
+	Buffer m;
+	Channel *c;
+	int client_fd, new_fd[3], ver, allowed;
+	socklen_t addrlen;
+	struct sockaddr_storage addr;
+	struct confirm_ctx *cctx;
+	char *cmd;
+	u_int i, len, env_len, command, flags;
+	uid_t euid;
+	gid_t egid;
+
+	/*
+	 * Accept connection on control socket
+	 */
+	if (control_fd == -1 || !FD_ISSET(control_fd, readset))
+		return;
+
+	memset(&addr, 0, sizeof(addr));
+	addrlen = sizeof(addr);
+	if ((client_fd = accept(control_fd,
+	    (struct sockaddr*)&addr, &addrlen)) == -1) {
+		error("%s accept: %s", __func__, strerror(errno));
+		return;
+	}
+
+	if (getpeereid(client_fd, &euid, &egid) < 0) {
+		error("%s getpeereid failed: %s", __func__, strerror(errno));
+		close(client_fd);
+		return;
+	}
+	if ((euid != 0) && (getuid() != euid)) {
+		error("control mode uid mismatch: peer euid %u != uid %u",
+		    (u_int) euid, (u_int) getuid());
+		close(client_fd);
+		return;
+	}
+
+	unset_nonblock(client_fd);
+
+	/* Read command */
+	buffer_init(&m);
+	if (ssh_msg_recv(client_fd, &m) == -1) {
+		error("%s: client msg_recv failed", __func__);
+		close(client_fd);
+		buffer_free(&m);
+		return;
+	}
+	if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
+		error("%s: wrong client version %d", __func__, ver);
+		buffer_free(&m);
+		close(client_fd);
+		return;
+	}
+
+	allowed = 1;
+	command = buffer_get_int(&m);
+	flags = buffer_get_int(&m);
+
+	buffer_clear(&m);
+
+	switch (command) {
+	case SSHMUX_COMMAND_OPEN:
+		if (options.control_master == SSHCTL_MASTER_ASK ||
+		    options.control_master == SSHCTL_MASTER_AUTO_ASK)
+			allowed = ask_permission("Allow shared connection "
+			    "to %s? ", host);
+		/* continue below */
+		break;
+	case SSHMUX_COMMAND_TERMINATE:
+		if (options.control_master == SSHCTL_MASTER_ASK ||
+		    options.control_master == SSHCTL_MASTER_AUTO_ASK)
+			allowed = ask_permission("Terminate shared connection "
+			    "to %s? ", host);
+		if (allowed)
+			quit_pending = 1;
+		/* FALLTHROUGH */
+	case SSHMUX_COMMAND_ALIVE_CHECK:
+		/* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */
+		buffer_clear(&m);
+		buffer_put_int(&m, allowed);
+		buffer_put_int(&m, getpid());
+		if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
+			error("%s: client msg_send failed", __func__);
+			close(client_fd);
+			buffer_free(&m);
+			return;
+		}
+		buffer_free(&m);
+		close(client_fd);
+		return;
+	default:
+		error("Unsupported command %d", command);
+		buffer_free(&m);
+		close(client_fd);
+		return;
+	}
+
+	/* Reply for SSHMUX_COMMAND_OPEN */
+	buffer_clear(&m);
+	buffer_put_int(&m, allowed);
+	buffer_put_int(&m, getpid());
+	if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
+		error("%s: client msg_send failed", __func__);
+		close(client_fd);
+		buffer_free(&m);
+		return;
+	}
+
+	if (!allowed) {
+		error("Refused control connection");
+		close(client_fd);
+		buffer_free(&m);
+		return;
+	}
+
+	buffer_clear(&m);
+	if (ssh_msg_recv(client_fd, &m) == -1) {
+		error("%s: client msg_recv failed", __func__);
+		close(client_fd);
+		buffer_free(&m);
+		return;
+	}
+	if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
+		error("%s: wrong client version %d", __func__, ver);
+		buffer_free(&m);
+		close(client_fd);
+		return;
+	}
+
+	cctx = xcalloc(1, sizeof(*cctx));
+	cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0;
+	cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0;
+	cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
+	cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
+	cctx->term = buffer_get_string(&m, &len);
+
+	cmd = buffer_get_string(&m, &len);
+	buffer_init(&cctx->cmd);
+	buffer_append(&cctx->cmd, cmd, strlen(cmd));
+
+	env_len = buffer_get_int(&m);
+	env_len = MIN(env_len, 4096);
+	debug3("%s: receiving %d env vars", __func__, env_len);
+	if (env_len != 0) {
+		cctx->env = xcalloc(env_len + 1, sizeof(*cctx->env));
+		for (i = 0; i < env_len; i++)
+			cctx->env[i] = buffer_get_string(&m, &len);
+		cctx->env[i] = NULL;
+	}
+
+	debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__,
+	    cctx->want_tty, cctx->want_subsys, cmd);
+	xfree(cmd);
+
+	/* Gather fds from client */
+	new_fd[0] = mm_receive_fd(client_fd);
+	new_fd[1] = mm_receive_fd(client_fd);
+	new_fd[2] = mm_receive_fd(client_fd);
+
+	debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__,
+	    new_fd[0], new_fd[1], new_fd[2]);
+
+	/* Try to pick up ttymodes from client before it goes raw */
+	if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
+		error("%s: tcgetattr: %s", __func__, strerror(errno));
+
+	/* This roundtrip is just for synchronisation of ttymodes */
+	buffer_clear(&m);
+	if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
+		error("%s: client msg_send failed", __func__);
+		close(client_fd);
+		close(new_fd[0]);
+		close(new_fd[1]);
+		close(new_fd[2]);
+		buffer_free(&m);
+		xfree(cctx->term);
+		if (env_len != 0) {
+			for (i = 0; i < env_len; i++)
+				xfree(cctx->env[i]);
+			xfree(cctx->env);
+		}
+		return;
+	}
+	buffer_free(&m);
+
+	/* enable nonblocking unless tty */
+	if (!isatty(new_fd[0]))
+		set_nonblock(new_fd[0]);
+	if (!isatty(new_fd[1]))
+		set_nonblock(new_fd[1]);
+	if (!isatty(new_fd[2]))
+		set_nonblock(new_fd[2]);
+
+	set_nonblock(client_fd);
+
+	c = channel_new("session", SSH_CHANNEL_OPENING,
+	    new_fd[0], new_fd[1], new_fd[2],
+	    CHAN_SES_WINDOW_DEFAULT, CHAN_SES_PACKET_DEFAULT,
+	    CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0);
+
+	/* XXX */
+	c->ctl_fd = client_fd;
+
+	debug3("%s: channel_new: %d", __func__, c->self);
+
+	channel_send_open(c->self);
+	channel_register_confirm(c->self, client_extra_session2_setup, cctx);
+}
+
+static void
+process_cmdline(void)
+{
+	void (*handler)(int);
+	char *s, *cmd, *cancel_host;
+	int delete = 0;
+	int local = 0;
+	u_short cancel_port;
+	Forward fwd;
+
+	leave_raw_mode();
+	handler = signal(SIGINT, SIG_IGN);
+	cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
+	if (s == NULL)
+		goto out;
+	while (*s && isspace(*s))
+		s++;
+	if (*s == '-')
+		s++;	/* Skip cmdline '-', if any */
+	if (*s == '\0')
+		goto out;
+
+	if (*s == 'h' || *s == 'H' || *s == '?') {
+		logit("Commands:");
+		logit("      -L[bind_address:]port:host:hostport    "
+		    "Request local forward");
+		logit("      -R[bind_address:]port:host:hostport    "
+		    "Request remote forward");
+		logit("      -KR[bind_address:]port                 "
+		    "Cancel remote forward");
+		if (!options.permit_local_command)
+			goto out;
+		logit("      !args                                  "
+		    "Execute local command");
+		goto out;
+	}
+
+	if (*s == '!' && options.permit_local_command) {
+		s++;
+		ssh_local_cmd(s);
+		goto out;
+	}
+
+	if (*s == 'K') {
+		delete = 1;
+		s++;
+	}
+	if (*s != 'L' && *s != 'R') {
+		logit("Invalid command.");
+		goto out;
+	}
+	if (*s == 'L')
+		local = 1;
+	if (local && delete) {
+		logit("Not supported.");
+		goto out;
+	}
+	if ((!local || delete) && !compat20) {
+		logit("Not supported for SSH protocol version 1.");
+		goto out;
+	}
+
+	s++;
+	while (*s && isspace(*s))
+		s++;
+
+	if (delete) {
+		cancel_port = 0;
+		cancel_host = hpdelim(&s);	/* may be NULL */
+		if (s != NULL) {
+			cancel_port = a2port(s);
+			cancel_host = cleanhostname(cancel_host);
+		} else {
+			cancel_port = a2port(cancel_host);
+			cancel_host = NULL;
+		}
+		if (cancel_port == 0) {
+			logit("Bad forwarding close port");
+			goto out;
+		}
+		channel_request_rforward_cancel(cancel_host, cancel_port);
+	} else {
+		if (!parse_forward(&fwd, s)) {
+			logit("Bad forwarding specification.");
+			goto out;
+		}
+		if (local) {
+			if (channel_setup_local_fwd_listener(fwd.listen_host,
+			    fwd.listen_port, fwd.connect_host,
+			    fwd.connect_port, options.gateway_ports) < 0) {
+				logit("Port forwarding failed.");
+				goto out;
+			}
+		} else {
+			if (channel_request_remote_forwarding(fwd.listen_host,
+			    fwd.listen_port, fwd.connect_host,
+			    fwd.connect_port) < 0) {
+				logit("Port forwarding failed.");
+				goto out;
+			}
+		}
+
+		logit("Forwarding port.");
+	}
+
+out:
+	signal(SIGINT, handler);
+	enter_raw_mode();
+	if (cmd)
+		xfree(cmd);
+}
+
+/* process the characters one by one */
+static int
+process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
+{
+	char string[1024];
+	pid_t pid;
+	int bytes = 0;
+	u_int i;
+	u_char ch;
+	char *s;
+
+	if (len <= 0)
+		return (0);
+
+	for (i = 0; i < (u_int)len; i++) {
+		/* Get one character at a time. */
+		ch = buf[i];
+
+		if (escape_pending) {
+			/* We have previously seen an escape character. */
+			/* Clear the flag now. */
+			escape_pending = 0;
+
+			/* Process the escaped character. */
+			switch (ch) {
+			case '.':
+				/* Terminate the connection. */
+				snprintf(string, sizeof string, "%c.\r\n", escape_char);
+				buffer_append(berr, string, strlen(string));
+
+				quit_pending = 1;
+				return -1;
+
+			case 'Z' - 64:
+				/* Suspend the program. */
+				/* Print a message to that effect to the user. */
+				snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
+				buffer_append(berr, string, strlen(string));
+
+				/* Restore terminal modes and suspend. */
+				client_suspend_self(bin, bout, berr);
+
+				/* We have been continued. */
+				continue;
+
+			case 'B':
+				if (compat20) {
+					snprintf(string, sizeof string,
+					    "%cB\r\n", escape_char);
+					buffer_append(berr, string,
+					    strlen(string));
+					channel_request_start(session_ident,
+					    "break", 0);
+					packet_put_int(1000);
+					packet_send();
+				}
+				continue;
+
+			case 'R':
+				if (compat20) {
+					if (datafellows & SSH_BUG_NOREKEY)
+						logit("Server does not support re-keying");
+					else
+						need_rekeying = 1;
+				}
+				continue;
+
+			case '&':
+				/*
+				 * Detach the program (continue to serve connections,
+				 * but put in background and no more new connections).
+				 */
+				/* Restore tty modes. */
+				leave_raw_mode();
+
+				/* Stop listening for new connections. */
+				channel_stop_listening();
+
+				snprintf(string, sizeof string,
+				    "%c& [backgrounded]\n", escape_char);
+				buffer_append(berr, string, strlen(string));
+
+				/* Fork into background. */
+				pid = fork();
+				if (pid < 0) {
+					error("fork: %.100s", strerror(errno));
+					continue;
+				}
+				if (pid != 0) {	/* This is the parent. */
+					/* The parent just exits. */
+					exit(0);
+				}
+				/* The child continues serving connections. */
+				if (compat20) {
+					buffer_append(bin, "\004", 1);
+					/* fake EOF on stdin */
+					return -1;
+				} else if (!stdin_eof) {
+					/*
+					 * Sending SSH_CMSG_EOF alone does not always appear
+					 * to be enough.  So we try to send an EOF character
+					 * first.
+					 */
+					packet_start(SSH_CMSG_STDIN_DATA);
+					packet_put_string("\004", 1);
+					packet_send();
+					/* Close stdin. */
+					stdin_eof = 1;
+					if (buffer_len(bin) == 0) {
+						packet_start(SSH_CMSG_EOF);
+						packet_send();
+					}
+				}
+				continue;
+
+			case '?':
+				snprintf(string, sizeof string,
+"%c?\r\n\
+Supported escape sequences:\r\n\
+%c.  - terminate connection\r\n\
+%cB  - send a BREAK to the remote system\r\n\
+%cC  - open a command line\r\n\
+%cR  - Request rekey (SSH protocol 2 only)\r\n\
+%c^Z - suspend ssh\r\n\
+%c#  - list forwarded connections\r\n\
+%c&  - background ssh (when waiting for connections to terminate)\r\n\
+%c?  - this message\r\n\
+%c%c  - send the escape character by typing it twice\r\n\
+(Note that escapes are only recognized immediately after newline.)\r\n",
+				    escape_char, escape_char, escape_char, escape_char,
+				    escape_char, escape_char, escape_char, escape_char,
+				    escape_char, escape_char, escape_char);
+				buffer_append(berr, string, strlen(string));
+				continue;
+
+			case '#':
+				snprintf(string, sizeof string, "%c#\r\n", escape_char);
+				buffer_append(berr, string, strlen(string));
+				s = channel_open_message();
+				buffer_append(berr, s, strlen(s));
+				xfree(s);
+				continue;
+
+			case 'C':
+				process_cmdline();
+				continue;
+
+			default:
+				if (ch != escape_char) {
+					buffer_put_char(bin, escape_char);
+					bytes++;
+				}
+				/* Escaped characters fall through here */
+				break;
+			}
+		} else {
+			/*
+			 * The previous character was not an escape char. Check if this
+			 * is an escape.
+			 */
+			if (last_was_cr && ch == escape_char) {
+				/* It is. Set the flag and continue to next character. */
+				escape_pending = 1;
+				continue;
+			}
+		}
+
+		/*
+		 * Normal character.  Record whether it was a newline,
+		 * and append it to the buffer.
+		 */
+		last_was_cr = (ch == '\r' || ch == '\n');
+		buffer_put_char(bin, ch);
+		bytes++;
+	}
+	return bytes;
+}
+
+static void
+client_process_input(fd_set *readset)
+{
+	int len;
+	char buf[8192];
+
+	/* Read input from stdin. */
+	if (FD_ISSET(fileno(stdin), readset)) {
+		/* Read as much as possible. */
+		len = read(fileno(stdin), buf, sizeof(buf));
+		if (len < 0 && (errno == EAGAIN || errno == EINTR))
+			return;		/* we'll try again later */
+		if (len <= 0) {
+			/*
+			 * Received EOF or error.  They are treated
+			 * similarly, except that an error message is printed
+			 * if it was an error condition.
+			 */
+			if (len < 0) {
+				snprintf(buf, sizeof buf, "read: %.100s\r\n", strerror(errno));
+				buffer_append(&stderr_buffer, buf, strlen(buf));
+			}
+			/* Mark that we have seen EOF. */
+			stdin_eof = 1;
+			/*
+			 * Send an EOF message to the server unless there is
+			 * data in the buffer.  If there is data in the
+			 * buffer, no message will be sent now.  Code
+			 * elsewhere will send the EOF when the buffer
+			 * becomes empty if stdin_eof is set.
+			 */
+			if (buffer_len(&stdin_buffer) == 0) {
+				packet_start(SSH_CMSG_EOF);
+				packet_send();
+			}
+		} else if (escape_char == SSH_ESCAPECHAR_NONE) {
+			/*
+			 * Normal successful read, and no escape character.
+			 * Just append the data to buffer.
+			 */
+			buffer_append(&stdin_buffer, buf, len);
+		} else {
+			/*
+			 * Normal, successful read.  But we have an escape character
+			 * and have to process the characters one by one.
+			 */
+			if (process_escapes(&stdin_buffer, &stdout_buffer,
+			    &stderr_buffer, buf, len) == -1)
+				return;
+		}
+	}
+}
+
+static void
+client_process_output(fd_set *writeset)
+{
+	int len;
+	char buf[100];
+
+	/* Write buffered output to stdout. */
+	if (FD_ISSET(fileno(stdout), writeset)) {
+		/* Write as much data as possible. */
+		len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
+		    buffer_len(&stdout_buffer));
+		if (len <= 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				len = 0;
+			else {
+				/*
+				 * An error or EOF was encountered.  Put an
+				 * error message to stderr buffer.
+				 */
+				snprintf(buf, sizeof buf, "write stdout: %.50s\r\n", strerror(errno));
+				buffer_append(&stderr_buffer, buf, strlen(buf));
+				quit_pending = 1;
+				return;
+			}
+		}
+		/* Consume printed data from the buffer. */
+		buffer_consume(&stdout_buffer, len);
+		stdout_bytes += len;
+	}
+	/* Write buffered output to stderr. */
+	if (FD_ISSET(fileno(stderr), writeset)) {
+		/* Write as much data as possible. */
+		len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
+		    buffer_len(&stderr_buffer));
+		if (len <= 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				len = 0;
+			else {
+				/* EOF or error, but can't even print error message. */
+				quit_pending = 1;
+				return;
+			}
+		}
+		/* Consume printed characters from the buffer. */
+		buffer_consume(&stderr_buffer, len);
+		stderr_bytes += len;
+	}
+}
+
+/*
+ * Get packets from the connection input buffer, and process them as long as
+ * there are packets available.
+ *
+ * Any unknown packets received during the actual
+ * session cause the session to terminate.  This is
+ * intended to make debugging easier since no
+ * confirmations are sent.  Any compatible protocol
+ * extensions must be negotiated during the
+ * preparatory phase.
+ */
+
+static void
+client_process_buffered_input_packets(void)
+{
+	dispatch_run(DISPATCH_NONBLOCK, &quit_pending, compat20 ? xxx_kex : NULL);
+}
+
+/* scan buf[] for '~' before sending data to the peer */
+
+static int
+simple_escape_filter(Channel *c, char *buf, int len)
+{
+	/* XXX we assume c->extended is writeable */
+	return process_escapes(&c->input, &c->output, &c->extended, buf, len);
+}
+
+static void
+client_channel_closed(int id, void *arg)
+{
+	channel_cancel_cleanup(id);
+	session_closed = 1;
+	leave_raw_mode();
+}
+
+/*
+ * Implements the interactive session with the server.  This is called after
+ * the user has been authenticated, and a command has been started on the
+ * remote host.  If escape_char != SSH_ESCAPECHAR_NONE, it is the character
+ * used as an escape character for terminating or suspending the session.
+ */
+
+int
+client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
+{
+	fd_set *readset = NULL, *writeset = NULL;
+	double start_time, total_time;
+	int max_fd = 0, max_fd2 = 0, len, rekeying = 0;
+	u_int nalloc = 0;
+	char buf[100];
+
+	debug("Entering interactive session.");
+
+	start_time = get_current_time();
+
+	/* Initialize variables. */
+	escape_pending = 0;
+	last_was_cr = 1;
+	exit_status = -1;
+	stdin_eof = 0;
+	buffer_high = 64 * 1024;
+	connection_in = packet_get_connection_in();
+	connection_out = packet_get_connection_out();
+	max_fd = MAX(connection_in, connection_out);
+	if (control_fd != -1)
+		max_fd = MAX(max_fd, control_fd);
+
+	if (!compat20) {
+		/* enable nonblocking unless tty */
+		if (!isatty(fileno(stdin)))
+			set_nonblock(fileno(stdin));
+		if (!isatty(fileno(stdout)))
+			set_nonblock(fileno(stdout));
+		if (!isatty(fileno(stderr)))
+			set_nonblock(fileno(stderr));
+		max_fd = MAX(max_fd, fileno(stdin));
+		max_fd = MAX(max_fd, fileno(stdout));
+		max_fd = MAX(max_fd, fileno(stderr));
+	}
+	stdin_bytes = 0;
+	stdout_bytes = 0;
+	stderr_bytes = 0;
+	quit_pending = 0;
+	escape_char = escape_char_arg;
+
+	/* Initialize buffers. */
+	buffer_init(&stdin_buffer);
+	buffer_init(&stdout_buffer);
+	buffer_init(&stderr_buffer);
+
+	client_init_dispatch();
+
+	/*
+	 * Set signal handlers, (e.g. to restore non-blocking mode)
+	 * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
+	 */
+	if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
+		signal(SIGHUP, signal_handler);
+	if (signal(SIGINT, SIG_IGN) != SIG_IGN)
+		signal(SIGINT, signal_handler);
+	if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
+		signal(SIGQUIT, signal_handler);
+	if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
+		signal(SIGTERM, signal_handler);
+	signal(SIGWINCH, window_change_handler);
+
+	if (have_pty)
+		enter_raw_mode();
+
+	if (compat20) {
+		session_ident = ssh2_chan_id;
+		if (escape_char != SSH_ESCAPECHAR_NONE)
+			channel_register_filter(session_ident,
+			    simple_escape_filter, NULL);
+		if (session_ident != -1)
+			channel_register_cleanup(session_ident,
+			    client_channel_closed, 0);
+	} else {
+		/* Check if we should immediately send eof on stdin. */
+		client_check_initial_eof_on_stdin();
+	}
+
+	/* Main loop of the client for the interactive session mode. */
+	while (!quit_pending) {
+
+		/* Process buffered packets sent by the server. */
+		client_process_buffered_input_packets();
+
+		if (compat20 && session_closed && !channel_still_open())
+			break;
+
+		rekeying = (xxx_kex != NULL && !xxx_kex->done);
+
+		if (rekeying) {
+			debug("rekeying in progress");
+		} else {
+			/*
+			 * Make packets of buffered stdin data, and buffer
+			 * them for sending to the server.
+			 */
+			if (!compat20)
+				client_make_packets_from_stdin_data();
+
+			/*
+			 * Make packets from buffered channel data, and
+			 * enqueue them for sending to the server.
+			 */
+			if (packet_not_very_much_data_to_write())
+				channel_output_poll();
+
+			/*
+			 * Check if the window size has changed, and buffer a
+			 * message about it to the server if so.
+			 */
+			client_check_window_change();
+
+			if (quit_pending)
+				break;
+		}
+		/*
+		 * Wait until we have something to do (something becomes
+		 * available on one of the descriptors).
+		 */
+		max_fd2 = max_fd;
+		client_wait_until_can_do_something(&readset, &writeset,
+		    &max_fd2, &nalloc, rekeying);
+
+		if (quit_pending)
+			break;
+
+		/* Do channel operations unless rekeying in progress. */
+		if (!rekeying) {
+			channel_after_select(readset, writeset);
+			if (need_rekeying || packet_need_rekeying()) {
+				debug("need rekeying");
+				xxx_kex->done = 0;
+				kex_send_kexinit(xxx_kex);
+				need_rekeying = 0;
+			}
+		}
+
+		/* Buffer input from the connection.  */
+		client_process_net_input(readset);
+
+		/* Accept control connections.  */
+		client_process_control(readset);
+
+		if (quit_pending)
+			break;
+
+		if (!compat20) {
+			/* Buffer data from stdin */
+			client_process_input(readset);
+			/*
+			 * Process output to stdout and stderr.  Output to
+			 * the connection is processed elsewhere (above).
+			 */
+			client_process_output(writeset);
+		}
+
+		/* Send as much buffered packet data as possible to the sender. */
+		if (FD_ISSET(connection_out, writeset))
+			packet_write_poll();
+	}
+	if (readset)
+		xfree(readset);
+	if (writeset)
+		xfree(writeset);
+
+	/* Terminate the session. */
+
+	/* Stop watching for window change. */
+	signal(SIGWINCH, SIG_DFL);
+
+	channel_free_all();
+
+	if (have_pty)
+		leave_raw_mode();
+
+	/* restore blocking io */
+	if (!isatty(fileno(stdin)))
+		unset_nonblock(fileno(stdin));
+	if (!isatty(fileno(stdout)))
+		unset_nonblock(fileno(stdout));
+	if (!isatty(fileno(stderr)))
+		unset_nonblock(fileno(stderr));
+
+	/*
+	 * If there was no shell or command requested, there will be no remote
+	 * exit status to be returned.  In that case, clear error code if the
+	 * connection was deliberately terminated at this end.
+	 */
+	if (no_shell_flag && received_signal == SIGTERM) {
+		received_signal = 0;
+		exit_status = 0;
+	}
+
+	if (received_signal)
+		fatal("Killed by signal %d.", (int) received_signal);
+
+	/*
+	 * In interactive mode (with pseudo tty) display a message indicating
+	 * that the connection has been closed.
+	 */
+	if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
+		snprintf(buf, sizeof buf, "Connection to %.64s closed.\r\n", host);
+		buffer_append(&stderr_buffer, buf, strlen(buf));
+	}
+
+	/* Output any buffered data for stdout. */
+	while (buffer_len(&stdout_buffer) > 0) {
+		len = write(fileno(stdout), buffer_ptr(&stdout_buffer),
+		    buffer_len(&stdout_buffer));
+		if (len <= 0) {
+			error("Write failed flushing stdout buffer.");
+			break;
+		}
+		buffer_consume(&stdout_buffer, len);
+		stdout_bytes += len;
+	}
+
+	/* Output any buffered data for stderr. */
+	while (buffer_len(&stderr_buffer) > 0) {
+		len = write(fileno(stderr), buffer_ptr(&stderr_buffer),
+		    buffer_len(&stderr_buffer));
+		if (len <= 0) {
+			error("Write failed flushing stderr buffer.");
+			break;
+		}
+		buffer_consume(&stderr_buffer, len);
+		stderr_bytes += len;
+	}
+
+	/* Clear and free any buffers. */
+	memset(buf, 0, sizeof(buf));
+	buffer_free(&stdin_buffer);
+	buffer_free(&stdout_buffer);
+	buffer_free(&stderr_buffer);
+
+	/* Report bytes transferred, and transfer rates. */
+	total_time = get_current_time() - start_time;
+	debug("Transferred: stdin %lu, stdout %lu, stderr %lu bytes in %.1f seconds",
+	    stdin_bytes, stdout_bytes, stderr_bytes, total_time);
+	if (total_time > 0)
+		debug("Bytes per second: stdin %.1f, stdout %.1f, stderr %.1f",
+		    stdin_bytes / total_time, stdout_bytes / total_time,
+		    stderr_bytes / total_time);
+
+	/* Return the exit status of the program. */
+	debug("Exit status %d", exit_status);
+	return exit_status;
+}
+
+/*********/
+
+static void
+client_input_stdout_data(int type, u_int32_t seq, void *ctxt)
+{
+	u_int data_len;
+	char *data = packet_get_string(&data_len);
+	packet_check_eom();
+	buffer_append(&stdout_buffer, data, data_len);
+	memset(data, 0, data_len);
+	xfree(data);
+}
+static void
+client_input_stderr_data(int type, u_int32_t seq, void *ctxt)
+{
+	u_int data_len;
+	char *data = packet_get_string(&data_len);
+	packet_check_eom();
+	buffer_append(&stderr_buffer, data, data_len);
+	memset(data, 0, data_len);
+	xfree(data);
+}
+static void
+client_input_exit_status(int type, u_int32_t seq, void *ctxt)
+{
+	exit_status = packet_get_int();
+	packet_check_eom();
+	/* Acknowledge the exit. */
+	packet_start(SSH_CMSG_EXIT_CONFIRMATION);
+	packet_send();
+	/*
+	 * Must wait for packet to be sent since we are
+	 * exiting the loop.
+	 */
+	packet_write_wait();
+	/* Flag that we want to exit. */
+	quit_pending = 1;
+}
+static void
+client_input_agent_open(int type, u_int32_t seq, void *ctxt)
+{
+	Channel *c = NULL;
+	int remote_id, sock;
+
+	/* Read the remote channel number from the message. */
+	remote_id = packet_get_int();
+	packet_check_eom();
+
+	/*
+	 * Get a connection to the local authentication agent (this may again
+	 * get forwarded).
+	 */
+	sock = ssh_get_authentication_socket();
+
+	/*
+	 * If we could not connect the agent, send an error message back to
+	 * the server. This should never happen unless the agent dies,
+	 * because authentication forwarding is only enabled if we have an
+	 * agent.
+	 */
+	if (sock >= 0) {
+		c = channel_new("", SSH_CHANNEL_OPEN, sock, sock,
+		    -1, 0, 0, 0, "authentication agent connection", 1);
+		c->remote_id = remote_id;
+		c->force_drain = 1;
+	}
+	if (c == NULL) {
+		packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
+		packet_put_int(remote_id);
+	} else {
+		/* Send a confirmation to the remote host. */
+		debug("Forwarding authentication connection.");
+		packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
+		packet_put_int(remote_id);
+		packet_put_int(c->self);
+	}
+	packet_send();
+}
+
+static Channel *
+client_request_forwarded_tcpip(const char *request_type, int rchan)
+{
+	Channel *c = NULL;
+	char *listen_address, *originator_address;
+	int listen_port, originator_port;
+	int sock;
+
+	/* Get rest of the packet */
+	listen_address = packet_get_string(NULL);
+	listen_port = packet_get_int();
+	originator_address = packet_get_string(NULL);
+	originator_port = packet_get_int();
+	packet_check_eom();
+
+	debug("client_request_forwarded_tcpip: listen %s port %d, originator %s port %d",
+	    listen_address, listen_port, originator_address, originator_port);
+
+	sock = channel_connect_by_listen_address(listen_port);
+	if (sock < 0) {
+		xfree(originator_address);
+		xfree(listen_address);
+		return NULL;
+	}
+	c = channel_new("forwarded-tcpip",
+	    SSH_CHANNEL_CONNECTING, sock, sock, -1,
+	    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
+	    originator_address, 1);
+	xfree(originator_address);
+	xfree(listen_address);
+	return c;
+}
+
+static Channel *
+client_request_x11(const char *request_type, int rchan)
+{
+	Channel *c = NULL;
+	char *originator;
+	int originator_port;
+	int sock;
+
+	if (!options.forward_x11) {
+		error("Warning: ssh server tried X11 forwarding.");
+		error("Warning: this is probably a break-in attempt by a malicious server.");
+		return NULL;
+	}
+	originator = packet_get_string(NULL);
+	if (datafellows & SSH_BUG_X11FWD) {
+		debug2("buggy server: x11 request w/o originator_port");
+		originator_port = 0;
+	} else {
+		originator_port = packet_get_int();
+	}
+	packet_check_eom();
+	/* XXX check permission */
+	debug("client_request_x11: request from %s %d", originator,
+	    originator_port);
+	xfree(originator);
+	sock = x11_connect_display();
+	if (sock < 0)
+		return NULL;
+	c = channel_new("x11",
+	    SSH_CHANNEL_X11_OPEN, sock, sock, -1,
+	    CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
+	c->force_drain = 1;
+	return c;
+}
+
+static Channel *
+client_request_agent(const char *request_type, int rchan)
+{
+	Channel *c = NULL;
+	int sock;
+
+	if (!options.forward_agent) {
+		error("Warning: ssh server tried agent forwarding.");
+		error("Warning: this is probably a break-in attempt by a malicious server.");
+		return NULL;
+	}
+	sock =  ssh_get_authentication_socket();
+	if (sock < 0)
+		return NULL;
+	c = channel_new("authentication agent connection",
+	    SSH_CHANNEL_OPEN, sock, sock, -1,
+	    CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_WINDOW_DEFAULT, 0,
+	    "authentication agent connection", 1);
+	c->force_drain = 1;
+	return c;
+}
+
+/* XXXX move to generic input handler */
+static void
+client_input_channel_open(int type, u_int32_t seq, void *ctxt)
+{
+	Channel *c = NULL;
+	char *ctype;
+	int rchan;
+	u_int rmaxpack, rwindow, len;
+
+	ctype = packet_get_string(&len);
+	rchan = packet_get_int();
+	rwindow = packet_get_int();
+	rmaxpack = packet_get_int();
+
+	debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
+	    ctype, rchan, rwindow, rmaxpack);
+
+	if (strcmp(ctype, "forwarded-tcpip") == 0) {
+		c = client_request_forwarded_tcpip(ctype, rchan);
+	} else if (strcmp(ctype, "x11") == 0) {
+		c = client_request_x11(ctype, rchan);
+	} else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
+		c = client_request_agent(ctype, rchan);
+	}
+/* XXX duplicate : */
+	if (c != NULL) {
+		debug("confirm %s", ctype);
+		c->remote_id = rchan;
+		c->remote_window = rwindow;
+		c->remote_maxpacket = rmaxpack;
+		if (c->type != SSH_CHANNEL_CONNECTING) {
+			packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
+			packet_put_int(c->remote_id);
+			packet_put_int(c->self);
+			packet_put_int(c->local_window);
+			packet_put_int(c->local_maxpacket);
+			packet_send();
+		}
+	} else {
+		debug("failure %s", ctype);
+		packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
+		packet_put_int(rchan);
+		packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
+		if (!(datafellows & SSH_BUG_OPENFAILURE)) {
+			packet_put_cstring("open failed");
+			packet_put_cstring("");
+		}
+		packet_send();
+	}
+	xfree(ctype);
+}
+static void
+client_input_channel_req(int type, u_int32_t seq, void *ctxt)
+{
+	Channel *c = NULL;
+	int exitval, id, reply, success = 0;
+	char *rtype;
+
+	id = packet_get_int();
+	rtype = packet_get_string(NULL);
+	reply = packet_get_char();
+
+	debug("client_input_channel_req: channel %d rtype %s reply %d",
+	    id, rtype, reply);
+
+	if (id == -1) {
+		error("client_input_channel_req: request for channel -1");
+	} else if ((c = channel_lookup(id)) == NULL) {
+		error("client_input_channel_req: channel %d: unknown channel", id);
+	} else if (strcmp(rtype, "exit-status") == 0) {
+		exitval = packet_get_int();
+		if (id == session_ident) {
+			success = 1;
+			exit_status = exitval;
+		} else if (c->ctl_fd == -1) {
+			error("client_input_channel_req: unexpected channel %d",
+			    session_ident);
+		} else {
+			atomicio(vwrite, c->ctl_fd, &exitval, sizeof(exitval));
+			success = 1;
+		}
+		packet_check_eom();
+	}
+	if (reply) {
+		packet_start(success ?
+		    SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
+		packet_put_int(id);
+		packet_send();
+	}
+	xfree(rtype);
+}
+static void
+client_input_global_request(int type, u_int32_t seq, void *ctxt)
+{
+	char *rtype;
+	int want_reply;
+	int success = 0;
+
+	rtype = packet_get_string(NULL);
+	want_reply = packet_get_char();
+	debug("client_input_global_request: rtype %s want_reply %d",
+	    rtype, want_reply);
+	if (want_reply) {
+		packet_start(success ?
+		    SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
+		packet_send();
+		packet_write_wait();
+	}
+	xfree(rtype);
+}
+
+void
+client_session2_setup(int id, int want_tty, int want_subsystem,
+    const char *term, struct termios *tiop, int in_fd, Buffer *cmd, char **env,
+    dispatch_fn *subsys_repl)
+{
+	int len;
+	Channel *c = NULL;
+
+	debug2("%s: id %d", __func__, id);
+
+	if ((c = channel_lookup(id)) == NULL)
+		fatal("client_session2_setup: channel %d: unknown channel", id);
+
+	if (want_tty) {
+		struct winsize ws;
+		struct termios tio;
+
+		/* Store window size in the packet. */
+		if (ioctl(in_fd, TIOCGWINSZ, &ws) < 0)
+			memset(&ws, 0, sizeof(ws));
+
+		channel_request_start(id, "pty-req", 0);
+		packet_put_cstring(term != NULL ? term : "");
+		packet_put_int((u_int)ws.ws_col);
+		packet_put_int((u_int)ws.ws_row);
+		packet_put_int((u_int)ws.ws_xpixel);
+		packet_put_int((u_int)ws.ws_ypixel);
+		tio = get_saved_tio();
+		tty_make_modes(-1, tiop != NULL ? tiop : &tio);
+		packet_send();
+		/* XXX wait for reply */
+		c->client_tty = 1;
+	}
+
+	/* Transfer any environment variables from client to server */
+	if (options.num_send_env != 0 && env != NULL) {
+		int i, j, matched;
+		char *name, *val;
+
+		debug("Sending environment.");
+		for (i = 0; env[i] != NULL; i++) {
+			/* Split */
+			name = xstrdup(env[i]);
+			if ((val = strchr(name, '=')) == NULL) {
+				xfree(name);
+				continue;
+			}
+			*val++ = '\0';
+
+			matched = 0;
+			for (j = 0; j < options.num_send_env; j++) {
+				if (match_pattern(name, options.send_env[j])) {
+					matched = 1;
+					break;
+				}
+			}
+			if (!matched) {
+				debug3("Ignored env %s", name);
+				xfree(name);
+				continue;
+			}
+
+			debug("Sending env %s = %s", name, val);
+			channel_request_start(id, "env", 0);
+			packet_put_cstring(name);
+			packet_put_cstring(val);
+			packet_send();
+			xfree(name);
+		}
+	}
+
+	len = buffer_len(cmd);
+	if (len > 0) {
+		if (len > 900)
+			len = 900;
+		if (want_subsystem) {
+			debug("Sending subsystem: %.*s", len, (u_char*)buffer_ptr(cmd));
+			channel_request_start(id, "subsystem", subsys_repl != NULL);
+			if (subsys_repl != NULL) {
+				/* register callback for reply */
+				/* XXX we assume that client_loop has already been called */
+				dispatch_set(SSH2_MSG_CHANNEL_FAILURE, subsys_repl);
+				dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, subsys_repl);
+			}
+		} else {
+			debug("Sending command: %.*s", len, (u_char*)buffer_ptr(cmd));
+			channel_request_start(id, "exec", 0);
+		}
+		packet_put_string(buffer_ptr(cmd), buffer_len(cmd));
+		packet_send();
+	} else {
+		channel_request_start(id, "shell", 0);
+		packet_send();
+	}
+}
+
+static void
+client_init_dispatch_20(void)
+{
+	dispatch_init(&dispatch_protocol_error);
+
+	dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
+	dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
+	dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
+	dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
+	dispatch_set(SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
+	dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
+	dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
+	dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
+	dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
+	dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
+
+	/* rekeying */
+	dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
+
+	/* global request reply messages */
+	dispatch_set(SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
+	dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
+}
+static void
+client_init_dispatch_13(void)
+{
+	dispatch_init(NULL);
+	dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
+	dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
+	dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
+	dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
+	dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
+	dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
+	dispatch_set(SSH_SMSG_EXITSTATUS, &client_input_exit_status);
+	dispatch_set(SSH_SMSG_STDERR_DATA, &client_input_stderr_data);
+	dispatch_set(SSH_SMSG_STDOUT_DATA, &client_input_stdout_data);
+
+	dispatch_set(SSH_SMSG_AGENT_OPEN, options.forward_agent ?
+	    &client_input_agent_open : &deny_input_open);
+	dispatch_set(SSH_SMSG_X11_OPEN, options.forward_x11 ?
+	    &x11_input_open : &deny_input_open);
+}
+static void
+client_init_dispatch_15(void)
+{
+	client_init_dispatch_13();
+	dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
+	dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, & channel_input_oclose);
+}
+static void
+client_init_dispatch(void)
+{
+	if (compat20)
+		client_init_dispatch_20();
+	else if (compat13)
+		client_init_dispatch_13();
+	else
+		client_init_dispatch_15();
+}
+
+/* client specific fatal cleanup */
+void
+cleanup_exit(int i)
+{
+	leave_raw_mode();
+	leave_non_blocking();
+	if (options.control_path != NULL && control_fd != -1)
+		unlink(options.control_path);
+	_exit(i);
+}