* New upstream release (closes: #474301). Important changes not previously

  backported to 4.7p1:
  - 4.9/4.9p1 (http://www.openssh.com/txt/release-4.9):
    + Added chroot(2) support for sshd(8), controlled by a new option
      "ChrootDirectory" (closes: #139047, LP: #24777).
    + Linked sftp-server(8) into sshd(8). The internal sftp server is used
      when the command "internal-sftp" is specified in a Subsystem or
      ForceCommand declaration. When used with ChrootDirectory, the
      internal sftp server requires no special configuration of files
      inside the chroot environment.
    + Added a protocol extension method "posix-rename@openssh.com" for
      sftp-server(8) to perform POSIX atomic rename() operations; sftp(1)
      prefers this if available (closes: #308561).
    + Removed the fixed limit of 100 file handles in sftp-server(8).
    + ssh(8) will now skip generation of SSH protocol 1 ephemeral server
      keys when in inetd mode and protocol 2 connections are negotiated.
      This speeds up protocol 2 connections to inetd-mode servers that
      also allow Protocol 1.
    + Accept the PermitRootLogin directive in a sshd_config(5) Match
      block. Allows for, e.g. permitting root only from the local network.
    + Reworked sftp(1) argument splitting and escaping to be more
      internally consistent (i.e. between sftp commands) and more
      consistent with sh(1). Please note that this will change the
      interpretation of some quoted strings, especially those with
      embedded backslash escape sequences.
    + Support "Banner=none" in sshd_config(5) to disable sending of a
      pre-login banner (e.g. in a Match block).
    + ssh(1) ProxyCommands are now executed with $SHELL rather than
      /bin/sh.
    + ssh(1)'s ConnectTimeout option is now applied to both the TCP
      connection and the SSH banner exchange (previously it just covered
      the TCP connection). This allows callers of ssh(1) to better detect
      and deal with stuck servers that accept a TCP connection but don't
      progress the protocol, and also makes ConnectTimeout useful for
      connections via a ProxyCommand.
    + scp(1) incorrectly reported "stalled" on slow copies (closes:
      #140828).
    + scp(1) date underflow for timestamps before epoch.
    + ssh(1) used the obsolete SIG DNS RRtype for host keys in DNS,
      instead of the current standard RRSIG.
    + Correctly drain ACKs when a sftp(1) upload write fails midway,
      avoids a fatal() exit from what should be a recoverable condition.
    + Fixed ssh-keygen(1) selective host key hashing (i.e. "ssh-keygen -HF
      hostname") to not include any IP address in the data to be hashed.
    + Make ssh(1) skip listening on the IPv6 wildcard address when a
      binding address of 0.0.0.0 is used against an old SSH server that
      does not support the RFC4254 syntax for wildcard bind addresses.
    + Enable IPV6_V6ONLY socket option on sshd(8) listen socket, as is
      already done for X11/TCP forwarding sockets (closes: #439661).
    + Fix FD leak that could hang a ssh(1) connection multiplexing master.
    + Make ssh(1) -q option documentation consistent with reality.
    + Fixed sshd(8) PAM support not calling pam_session_close(), or
      failing to call it with root privileges (closes: #372680).
    + Fix activation of OpenSSL engine support when requested in configure
      (LP: #119295).
  - 5.1/5.1p1 (http://www.openssh.com/txt/release-5.1):
    + Introduce experimental SSH Fingerprint ASCII Visualisation to ssh(1)
      and ssh-keygen(1). Visual fingerprint display is controlled by a new
      ssh_config(5) option "VisualHostKey". The intent is to render SSH
      host keys in a visual form that is amenable to easy recall and
      rejection of changed host keys.
    + sshd_config(5) now supports CIDR address/masklen matching in "Match
      address" blocks, with a fallback to classic wildcard matching.
    + sshd(8) now supports CIDR matching in ~/.ssh/authorized_keys
      from="..." restrictions, also with a fallback to classic wildcard
      matching.
    + Added an extended test mode (-T) to sshd(8) to request that it write
      its effective configuration to stdout and exit. Extended test mode
      also supports the specification of connection parameters (username,
      source address and hostname) to test the application of
      sshd_config(5) Match rules.
    + ssh(1) now prints the number of bytes transferred and the overall
      connection throughput for SSH protocol 2 sessions when in verbose
      mode (previously these statistics were displayed for protocol 1
      connections only).
    + sftp-server(8) now supports extension methods statvfs@openssh.com
      and fstatvfs@openssh.com that implement statvfs(2)-like operations.
    + sftp(1) now has a "df" command to the sftp client that uses the
      statvfs@openssh.com to produce a df(1)-like display of filesystem
      space and inode utilisation (requires statvfs@openssh.com support on
      the server).
    + Added a MaxSessions option to sshd_config(5) to allow control of the
      number of multiplexed sessions supported over a single TCP
      connection. This allows increasing the number of allowed sessions
      above the previous default of 10, disabling connection multiplexing
      (MaxSessions=1) or disallowing login/shell/subsystem sessions
      entirely (MaxSessions=0).
    + Added a no-more-sessions@openssh.com global request extension that
      is sent from ssh(1) to sshd(8) when the client knows that it will
      never request another session (i.e. when session multiplexing is
      disabled). This allows a server to disallow further session requests
      and terminate the session in cases where the client has been
      hijacked.
    + ssh-keygen(1) now supports the use of the -l option in combination
      with -F to search for a host in ~/.ssh/known_hosts and display its
      fingerprint.
    + ssh-keyscan(1) now defaults to "rsa" (protocol 2) keys, instead of
      "rsa1".
    + Added an AllowAgentForwarding option to sshd_config(8) to control
      whether authentication agent forwarding is permitted. Note that this
      is a loose control, as a client may install their own unofficial
      forwarder.
    + ssh(1) and sshd(8): avoid unnecessary malloc/copy/free when
      receiving network data, resulting in a ~10% speedup.
    + ssh(1) and sshd(8) will now try additional addresses when connecting
      to a port forward destination whose DNS name resolves to more than
      one address. The previous behaviour was to try the only first
      address and give up if that failed.
    + ssh(1) and sshd(8) now support signalling that channels are
      half-closed for writing, through a channel protocol extension
      notification "eow@openssh.com". This allows propagation of closed
      file descriptors, so that commands such as "ssh -2 localhost od
      /bin/ls | true" do not send unnecessary data over the wire.
    + sshd(8): increased the default size of ssh protocol 1 ephemeral keys
      from 768 to 1024 bits.
    + When ssh(1) has been requested to fork after authentication ("ssh
      -f") with ExitOnForwardFailure enabled, delay the fork until after
      replies for any -R forwards have been seen. Allows for robust
      detection of -R forward failure when using -f.
    + "Match group" blocks in sshd_config(5) now support negation of
      groups. E.g. "Match group staff,!guests".
    + sftp(1) and sftp-server(8) now allow chmod-like operations to set
      set[ug]id/sticky bits.
    + The MaxAuthTries option is now permitted in sshd_config(5) match
      blocks.
    + Multiplexed ssh(1) sessions now support a subset of the ~ escapes
      that are available to a primary connection.
    + ssh(1) connection multiplexing will now fall back to creating a new
      connection in most error cases (closes: #352830).
    + Make ssh(1) deal more gracefully with channel requests that fail.
      Previously it would optimistically assume that requests would always
      succeed, which could cause hangs if they did not (e.g. when the
      server runs out of file descriptors).
    + ssh(1) now reports multiplexing errors via the multiplex slave's
      stderr where possible (subject to LogLevel in the mux master).
    + Prevent sshd(8) from erroneously applying public key restrictions
      leaned from ~/.ssh/authorized_keys to other authentication methods
      when public key authentication subsequently fails (LP: #161047).
    + Fixed an UMAC alignment problem that manifested on Itanium
      platforms.

1 files changed, 170 insertions, 371 deletions

diff --git a/ssh.c b/ssh.c
index 85043a8c0..e2e2ef498 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.301 2007/08/07 07:32:53 djm Exp $ */
+/* $OpenBSD: ssh.c,v 1.318 2008/07/02 13:47:39 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -49,7 +49,6 @@
 #include <sys/resource.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>
-#include <sys/un.h>
 
 #include <ctype.h>
 #include <errno.h>
@@ -72,6 +71,8 @@
 
 #include <openssl/evp.h>
 #include <openssl/err.h>
+#include "openbsd-compat/openssl-compat.h"
+#include "openbsd-compat/sys-queue.h"
 
 #include "xmalloc.h"
 #include "ssh.h"
@@ -97,7 +98,6 @@
 #include "sshpty.h"
 #include "match.h"
 #include "msg.h"
-#include "monitor_fdpass.h"
 #include "uidswap.h"
 #include "version.h"
 
@@ -107,7 +107,7 @@
 
 extern char *__progname;
 
-/* Flag indicating whether debug mode is on.  This can be set on the command line. */
+/* Flag indicating whether debug mode is on.  May be set on the command line. */
 int debug_flag = 0;
 
 /* Flag indicating whether a tty should be allocated */
@@ -164,20 +164,14 @@ Buffer command;
 int subsystem_flag = 0;
 
 /* # of replies received for global requests */
-static int client_global_request_id = 0;
+static int remote_forward_confirms_received = 0;
 
 /* pid of proxycommand child process */
 pid_t proxy_command_pid = 0;
 
-/* fd to control socket */
-int control_fd = -1;
-
-/* Multiplexing control command */
-static u_int mux_command = 0;
-
-/* Only used in control client mode */
-volatile sig_atomic_t control_client_terminate = 0;
-u_int control_server_pid = 0;
+/* mux.c */
+extern int muxserver_sock;
+extern u_int muxclient_command;
 
 /* Prints a help message to the user.  This function never returns. */
 
@@ -198,7 +192,10 @@ usage(void)
 static int ssh_session(void);
 static int ssh_session2(void);
 static void load_public_identity_files(void);
-static void control_client(const char *path);
+
+/* from muxclient.c */
+void muxclient(const char *);
+void muxserver_listen(void);
 
 /*
  * Main program for the ssh client.
@@ -210,7 +207,7 @@ main(int ac, char **av)
         char *p, *cp, *line, buf[256];
         struct stat st;
         struct passwd *pw;
-        int dummy;
+        int dummy, timeout_ms;
         extern int optind, optreset;
         extern char *optarg;
         struct servent *sp;
@@ -264,15 +261,18 @@ main(int ac, char **av)
          */
         umask(022);
 
-        /* Initialize option structure to indicate that no values have been set. */
+        /*
+         * Initialize option structure to indicate that no values have been
+         * set.
+         */
         initialize_options(&options);
 
         /* Parse command-line arguments. */
         host = NULL;
 
  again:
-        while ((opt = getopt(ac, av,
-            "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:KL:MNO:PR:S:TVw:XY")) != -1) {
+        while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
+            "ACD:F:I:KL:MNO:PR:S:TVw:XY")) != -1) {
                 switch (opt) {
                 case '1':
                         options.protocol = SSH_PROTO_1;
@@ -308,9 +308,9 @@ main(int ac, char **av)
                         break;
                 case 'O':
                         if (strcmp(optarg, "check") == 0)
-                                mux_command = SSHMUX_COMMAND_ALIVE_CHECK;
+                                muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
                         else if (strcmp(optarg, "exit") == 0)
-                                mux_command = SSHMUX_COMMAND_TERMINATE;
+                                muxclient_command = SSHMUX_COMMAND_TERMINATE;
                         else
                                 fatal("Invalid multiplex command.");
                         break;
@@ -377,7 +377,8 @@ main(int ac, char **av)
                                 options.tun_open = SSH_TUNMODE_DEFAULT;
                         options.tun_local = a2tun(optarg, &options.tun_remote);
                         if (options.tun_local == SSH_TUNID_ERR) {
-                                fprintf(stderr, "Bad tun device '%s'\n", optarg);
+                                fprintf(stderr,
+                                    "Bad tun device '%s'\n", optarg);
                                 exit(255);
                         }
                         break;
@@ -485,7 +486,8 @@ main(int ac, char **av)
                         }
                         if (cp != NULL) {
                                 fwd.listen_port = a2port(cp);
-                                fwd.listen_host = cleanhostname(fwd.listen_host);
+                                fwd.listen_host =
+                                    cleanhostname(fwd.listen_host);
                         } else {
                                 fwd.listen_port = a2port(fwd.listen_host);
                                 fwd.listen_host = NULL;
@@ -591,8 +593,10 @@ main(int ac, char **av)
         }
 
         /* Cannot fork to background if no command. */
-        if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag)
-                fatal("Cannot fork into background without a command to execute.");
+        if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
+            !no_shell_flag)
+                fatal("Cannot fork into background without a command "
+                    "to execute.");
 
         /* Allocate a tty by default if no command specified. */
         if (buffer_len(&command) == 0)
@@ -604,7 +608,8 @@ main(int ac, char **av)
         /* Do not allocate a tty if stdin is not a tty. */
         if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
                 if (tty_flag && options.log_level > SYSLOG_LEVEL_QUIET)
-                        logit("Pseudo-terminal will not be allocated because stdin is not a terminal.");
+                        logit("Pseudo-terminal will not be allocated because "
+                            "stdin is not a terminal.");
                 tty_flag = 0;
         }
 
@@ -612,7 +617,8 @@ main(int ac, char **av)
          * Initialize "log" output.  Since we are the client all output
          * actually goes to stderr.
          */
-        log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
+        log_init(av[0],
+            options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
             SYSLOG_FACILITY_USER, 1);
 
         /*
@@ -646,6 +652,28 @@ main(int ac, char **av)
         if (options.user == NULL)
                 options.user = xstrdup(pw->pw_name);
 
+        /* Get default port if port has not been set. */
+        if (options.port == 0) {
+                sp = getservbyname(SSH_SERVICE_NAME, "tcp");
+                options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
+        }
+
+        if (options.local_command != NULL) {
+                char thishost[NI_MAXHOST];
+
+                if (gethostname(thishost, sizeof(thishost)) == -1)
+                        fatal("gethostname: %s", strerror(errno));
+                snprintf(buf, sizeof(buf), "%d", options.port);
+                debug3("expanding LocalCommand: %s", options.local_command);
+                cp = options.local_command;
+                options.local_command = percent_expand(cp, "d", pw->pw_dir,
+                    "h", options.hostname? options.hostname : host,
+                    "l", thishost, "n", host, "r", options.user, "p", buf,
+                    "u", pw->pw_name, (char *)NULL);
+                debug3("expanded LocalCommand: %s", options.local_command);
+                xfree(cp);
+        }
+
         if (options.hostname != NULL)
                 host = options.hostname;
 
@@ -656,18 +684,16 @@ main(int ac, char **av)
                                 *p = (char)tolower(*p);
         }
 
-        /* Get default port if port has not been set. */
-        if (options.port == 0) {
-                sp = getservbyname(SSH_SERVICE_NAME, "tcp");
-                options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
-        }
-
         if (options.proxy_command != NULL &&
-            strcmp(options.proxy_command, "none") == 0)
+            strcmp(options.proxy_command, "none") == 0) {
+                xfree(options.proxy_command);
                 options.proxy_command = NULL;
+        }
         if (options.control_path != NULL &&
-            strcmp(options.control_path, "none") == 0)
+            strcmp(options.control_path, "none") == 0) {
+                xfree(options.control_path);
                 options.control_path = NULL;
+        }
 
         if (options.control_path != NULL) {
                 char thishost[NI_MAXHOST];
@@ -677,18 +703,22 @@ main(int ac, char **av)
                 snprintf(buf, sizeof(buf), "%d", options.port);
                 cp = tilde_expand_filename(options.control_path,
                     original_real_uid);
+                xfree(options.control_path);
                 options.control_path = percent_expand(cp, "p", buf, "h", host,
                     "r", options.user, "l", thishost, (char *)NULL);
                 xfree(cp);
         }
-        if (mux_command != 0 && options.control_path == NULL)
+        if (muxclient_command != 0 && options.control_path == NULL)
                 fatal("No ControlPath specified for \"-O\" command");
         if (options.control_path != NULL)
-                control_client(options.control_path);
+                muxclient(options.control_path);
+
+        timeout_ms = options.connection_timeout * 1000;
 
         /* Open a connection to the remote host. */
         if (ssh_connect(host, &hostaddr, options.port,
-            options.address_family, options.connection_attempts,
+            options.address_family, options.connection_attempts, &timeout_ms,
+            options.tcp_keep_alive, 
 #ifdef HAVE_CYGWIN
             options.use_privileged_port,
 #else
@@ -697,6 +727,9 @@ main(int ac, char **av)
             options.proxy_command) != 0)
                 exit(255);
 
+        if (timeout_ms > 0)
+                debug3("timeout: %d ms remain after connect", timeout_ms);
+
         /*
          * If we successfully made the connection, load the host private key
          * in case we will need it later for combined rsa-rhosts
@@ -750,7 +783,8 @@ main(int ac, char **av)
          * Now that we are back to our own permissions, create ~/.ssh
          * directory if it doesn't already exist.
          */
-        snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
+        snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir,
+            strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
         if (stat(buf, &st) < 0)
                 if (mkdir(buf, 0700) < 0)
                         error("Could not create directory '%.200s'.", buf);
@@ -771,8 +805,9 @@ main(int ac, char **av)
 
         signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
 
-        /* Log into the remote system.  This never returns if the login fails. */
-        ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw);
+        /* Log into the remote system.  Never returns if the login fails. */
+        ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
+            pw, timeout_ms);
 
         /* We no longer need the private host keys.  Clear them now. */
         if (sensitive_data.nkeys != 0) {
@@ -800,7 +835,7 @@ main(int ac, char **av)
         exit_status = compat20 ? ssh_session2() : ssh_session();
         packet_close();
 
-        if (options.control_path != NULL && control_fd != -1)
+        if (options.control_path != NULL && muxserver_sock != -1)
                 unlink(options.control_path);
 
         /*
@@ -813,6 +848,34 @@ main(int ac, char **av)
         return exit_status;
 }
 
+/* Callback for remote forward global requests */
+static void
+ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
+{
+        Forward *rfwd = (Forward *)ctxt;
+
+        debug("remote forward %s for: listen %d, connect %s:%d",
+            type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
+            rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
+        if (type == SSH2_MSG_REQUEST_FAILURE) {
+                if (options.exit_on_forward_failure)
+                        fatal("Error: remote port forwarding failed for "
+                            "listen port %d", rfwd->listen_port);
+                else
+                        logit("Warning: remote port forwarding failed for "
+                            "listen port %d", rfwd->listen_port);
+        }
+        if (++remote_forward_confirms_received == options.num_remote_forwards) {
+                debug("All remote forwarding requests processed");
+                if (fork_after_authentication_flag) {
+                        fork_after_authentication_flag = 0;
+                        if (daemon(1, 1) < 0)
+                                fatal("daemon() failed: %.200s",
+                                    strerror(errno));
+                }
+        }
+}
+
 static void
 ssh_init_forwarding(void)
 {
@@ -861,6 +924,8 @@ ssh_init_forwarding(void)
                                 logit("Warning: Could not request remote "
                                     "forwarding.");
                 }
+                client_register_global_confirm(ssh_confirm_remote_forward,
+                    &options.remote_forwards[i]);
         }
 
         /* Initiate tunnel forwarding. */
@@ -897,10 +962,13 @@ ssh_session(void)
 
         /* Enable compression if requested. */
         if (options.compression) {
-                debug("Requesting compression at level %d.", options.compression_level);
+                debug("Requesting compression at level %d.",
+                    options.compression_level);
 
-                if (options.compression_level < 1 || options.compression_level > 9)
-                        fatal("Compression level must be from 1 (fast) to 9 (slow, best).");
+                if (options.compression_level < 1 ||
+                    options.compression_level > 9)
+                        fatal("Compression level must be from 1 (fast) to "
+                            "9 (slow, best).");
 
                 /* Send the request. */
                 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
@@ -913,7 +981,8 @@ ssh_session(void)
                 else if (type == SSH_SMSG_FAILURE)
                         logit("Warning: Remote host refused compression.");
                 else
-                        packet_disconnect("Protocol error waiting for compression response.");
+                        packet_disconnect("Protocol error waiting for "
+                            "compression response.");
         }
         /* Allocate a pseudo tty if appropriate. */
         if (tty_flag) {
@@ -950,9 +1019,11 @@ ssh_session(void)
                         interactive = 1;
                         have_tty = 1;
                 } else if (type == SSH_SMSG_FAILURE)
-                        logit("Warning: Remote host failed or refused to allocate a pseudo tty.");
+                        logit("Warning: Remote host failed or refused to "
+                            "allocate a pseudo tty.");
                 else
-                        packet_disconnect("Protocol error waiting for pty request response.");
+                        packet_disconnect("Protocol error waiting for pty "
+                            "request response.");
         }
         /* Request X11 forwarding if enabled and DISPLAY is set. */
         display = getenv("DISPLAY");
@@ -962,7 +1033,8 @@ ssh_session(void)
                 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.");
+                debug("Requesting X11 forwarding with authentication "
+                    "spoofing.");
                 x11_request_forwarding_with_spoofing(0, display, proto, data);
 
                 /* Read response from the server. */
@@ -972,7 +1044,8 @@ ssh_session(void)
                 } else if (type == SSH_SMSG_FAILURE) {
                         logit("Warning: Remote host denied X11 forwarding.");
                 } else {
-                        packet_disconnect("Protocol error waiting for X11 forwarding");
+                        packet_disconnect("Protocol error waiting for X11 "
+                            "forwarding");
                 }
         }
         /* Tell the packet module whether this is an interactive session. */
@@ -995,10 +1068,22 @@ ssh_session(void)
         /* Initiate port forwardings. */
         ssh_init_forwarding();
 
-        /* If requested, let ssh continue in the background. */
-        if (fork_after_authentication_flag)
+        /* Execute a local command */
+        if (options.local_command != NULL &&
+            options.permit_local_command)
+                ssh_local_cmd(options.local_command);
+
+        /*
+         * If requested and we are not interested in replies to remote
+         * forwarding requests, then let ssh continue in the background.
+         */
+        if (fork_after_authentication_flag &&
+            (!options.exit_on_forward_failure ||
+            options.num_remote_forwards == 0)) {
+                fork_after_authentication_flag = 0;
                 if (daemon(1, 1) < 0)
                         fatal("daemon() failed: %.200s", strerror(errno));
+        }
 
         /*
          * If a command was specified on the command line, execute the
@@ -1008,7 +1093,8 @@ ssh_session(void)
                 int len = buffer_len(&command);
                 if (len > 900)
                         len = 900;
-                debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command));
+                debug("Sending command: %.*s", len,
+                    (u_char *)buffer_ptr(&command));
                 packet_start(SSH_CMSG_EXEC_CMD);
                 packet_put_string(buffer_ptr(&command), buffer_len(&command));
                 packet_send();
@@ -1025,88 +1111,6 @@ ssh_session(void)
             options.escape_char : SSH_ESCAPECHAR_NONE, 0);
 }
 
-static void
-ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt)
-{
-        int id, len;
-
-        id = packet_get_int();
-        len = buffer_len(&command);
-        if (len > 900)
-                len = 900;
-        packet_check_eom();
-        if (type == SSH2_MSG_CHANNEL_FAILURE)
-                fatal("Request for subsystem '%.*s' failed on channel %d",
-                    len, (u_char *)buffer_ptr(&command), id);
-}
-
-void
-client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt)
-{
-        int i;
-
-        i = client_global_request_id++;
-        if (i >= options.num_remote_forwards)
-                return;
-        debug("remote forward %s for: listen %d, connect %s:%d",
-            type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
-            options.remote_forwards[i].listen_port,
-            options.remote_forwards[i].connect_host,
-            options.remote_forwards[i].connect_port);
-        if (type == SSH2_MSG_REQUEST_FAILURE) {
-                if (options.exit_on_forward_failure)
-                        fatal("Error: remote port forwarding failed for "
-                            "listen port %d",
-                            options.remote_forwards[i].listen_port);
-                else
-                        logit("Warning: remote port forwarding failed for "
-                            "listen port %d",
-                            options.remote_forwards[i].listen_port);
-        }
-}
-
-static void
-ssh_control_listener(void)
-{
-        struct sockaddr_un addr;
-        mode_t old_umask;
-        int addr_len;
-
-        if (options.control_path == NULL ||
-            options.control_master == SSHCTL_MASTER_NO)
-                return;
-
-        debug("setting up multiplex master socket");
-
-        memset(&addr, '\0', sizeof(addr));
-        addr.sun_family = AF_UNIX;
-        addr_len = offsetof(struct sockaddr_un, sun_path) +
-            strlen(options.control_path) + 1;
-
-        if (strlcpy(addr.sun_path, options.control_path,
-            sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
-                fatal("ControlPath too long");
-
-        if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
-                fatal("%s socket(): %s", __func__, strerror(errno));
-
-        old_umask = umask(0177);
-        if (bind(control_fd, (struct sockaddr *)&addr, addr_len) == -1) {
-                control_fd = -1;
-                if (errno == EINVAL || errno == EADDRINUSE)
-                        fatal("ControlSocket %s already exists",
-                            options.control_path);
-                else
-                        fatal("%s bind(): %s", __func__, strerror(errno));
-        }
-        umask(old_umask);
-
-        if (listen(control_fd, 64) == -1)
-                fatal("%s listen(): %s", __func__, strerror(errno));
-
-        set_nonblock(control_fd);
-}
-
 /* request pty/x11/agent/tcpfwd/shell for channel */
 static void
 ssh_session2_setup(int id, void *arg)
@@ -1122,7 +1126,8 @@ ssh_session2_setup(int id, void *arg)
                 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.");
+                debug("Requesting X11 forwarding with authentication "
+                    "spoofing.");
                 x11_request_forwarding_with_spoofing(id, display, proto, data);
                 interactive = 1;
                 /* XXX wait for reply */
@@ -1136,7 +1141,7 @@ ssh_session2_setup(int id, void *arg)
         }
 
         client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
-            NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply);
+            NULL, fileno(stdin), &command, environ);
 
         packet_set_interactive(interactive);
 }
@@ -1182,7 +1187,8 @@ ssh_session2_open(void)
 
         channel_send_open(c->self);
         if (!no_shell_flag)
-                channel_register_confirm(c->self, ssh_session2_setup, NULL);
+                channel_register_open_confirm(c->self,
+                    ssh_session2_setup, NULL);
 
         return c->self;
 }
@@ -1198,18 +1204,29 @@ ssh_session2(void)
         if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
                 id = ssh_session2_open();
 
+        /* If we don't expect to open a new session, then disallow it */
+        if (options.control_master == SSHCTL_MASTER_NO) {
+                debug("Requesting no-more-sessions@openssh.com");
+                packet_start(SSH2_MSG_GLOBAL_REQUEST);
+                packet_put_cstring("no-more-sessions@openssh.com");
+                packet_put_char(0);
+                packet_send();
+        }
+
         /* Execute a local command */
         if (options.local_command != NULL &&
             options.permit_local_command)
                 ssh_local_cmd(options.local_command);
 
         /* Start listening for multiplex clients */
-        ssh_control_listener();
+        muxserver_listen();
 
         /* If requested, let ssh continue in the background. */
-        if (fork_after_authentication_flag)
+        if (fork_after_authentication_flag) {
+                fork_after_authentication_flag = 0;
                 if (daemon(1, 1) < 0)
                         fatal("daemon() failed: %.200s", strerror(errno));
+        }
 
         return client_loop(tty_flag, tty_flag ?
             options.escape_char : SSH_ESCAPECHAR_NONE, id);
@@ -1219,6 +1236,7 @@ static void
 load_public_identity_files(void)
 {
         char *filename, *cp, thishost[NI_MAXHOST], *fp;
+        char *pwdir = NULL, *pwname = NULL;
         int i = 0;
         Key *public;
         struct passwd *pw;
@@ -1231,9 +1249,11 @@ load_public_identity_files(void)
                 int count = 0;
                 for (i = 0; keys[i] != NULL; i++) {
                         count++;
-                        memmove(&options.identity_files[1], &options.identity_files[0],
+                        memmove(&options.identity_files[1],
+                            &options.identity_files[0],
                             sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
-                        memmove(&options.identity_keys[1], &options.identity_keys[0],
+                        memmove(&options.identity_keys[1],
+                            &options.identity_keys[0],
                             sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
                         options.num_identity_files++;
                         options.identity_keys[0] = keys[i];
@@ -1247,14 +1267,16 @@ load_public_identity_files(void)
 #endif /* SMARTCARD */
         if ((pw = getpwuid(original_real_uid)) == NULL)
                 fatal("load_public_identity_files: getpwuid failed");
+        pwname = xstrdup(pw->pw_name);
+        pwdir = xstrdup(pw->pw_dir);
         if (gethostname(thishost, sizeof(thishost)) == -1)
                 fatal("load_public_identity_files: gethostname: %s",
                     strerror(errno));
         for (; i < options.num_identity_files; i++) {
                 cp = tilde_expand_filename(options.identity_files[i],
                     original_real_uid);
-                filename = percent_expand(cp, "d", pw->pw_dir,
-                    "u", pw->pw_name, "l", thishost, "h", host,
+                filename = percent_expand(cp, "d", pwdir,
+                    "u", pwname, "l", thishost, "h", host,
                     "r", options.user, (char *)NULL);
                 xfree(cp);
                 public = key_load_public(filename, NULL);
@@ -1280,231 +1302,8 @@ load_public_identity_files(void)
                 options.identity_files[i] = filename;
                 options.identity_keys[i] = public;
         }
-}
-
-static void
-control_client_sighandler(int signo)
-{
-        control_client_terminate = signo;
-}
-
-static void
-control_client_sigrelay(int signo)
-{
-        if (control_server_pid > 1)
-                kill(control_server_pid, signo);
-}
-
-static int
-env_permitted(char *env)
-{
-        int i, ret;
-        char name[1024], *cp;
-
-        if ((cp = strchr(env, '=')) == NULL || cp == env)
-                return (0);
-        ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env);
-        if (ret <= 0 || (size_t)ret >= sizeof(name))
-                fatal("env_permitted: name '%.100s...' too long", env);
-
-        for (i = 0; i < options.num_send_env; i++)
-                if (match_pattern(name, options.send_env[i]))
-                        return (1);
-
-        return (0);
-}
-
-static void
-control_client(const char *path)
-{
-        struct sockaddr_un addr;
-        int i, r, fd, sock, exitval[2], num_env, addr_len;
-        Buffer m;
-        char *term;
-        extern char **environ;
-        u_int  flags;
-
-        if (mux_command == 0)
-                mux_command = SSHMUX_COMMAND_OPEN;
-
-        switch (options.control_master) {
-        case SSHCTL_MASTER_AUTO:
-        case SSHCTL_MASTER_AUTO_ASK:
-                debug("auto-mux: Trying existing master");
-                /* FALLTHROUGH */
-        case SSHCTL_MASTER_NO:
-                break;
-        default:
-                return;
-        }
-
-        memset(&addr, '\0', sizeof(addr));
-        addr.sun_family = AF_UNIX;
-        addr_len = offsetof(struct sockaddr_un, sun_path) +
-            strlen(path) + 1;
-
-        if (strlcpy(addr.sun_path, path,
-            sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
-                fatal("ControlPath too long");
-
-        if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
-                fatal("%s socket(): %s", __func__, strerror(errno));
-
-        if (connect(sock, (struct sockaddr *)&addr, addr_len) == -1) {
-                if (mux_command != SSHMUX_COMMAND_OPEN) {
-                        fatal("Control socket connect(%.100s): %s", path,
-                            strerror(errno));
-                }
-                if (errno == ENOENT)
-                        debug("Control socket \"%.100s\" does not exist", path);
-                else {
-                        error("Control socket connect(%.100s): %s", path,
-                            strerror(errno));
-                }
-                close(sock);
-                return;
-        }
-
-        if (stdin_null_flag) {
-                if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1)
-                        fatal("open(/dev/null): %s", strerror(errno));
-                if (dup2(fd, STDIN_FILENO) == -1)
-                        fatal("dup2: %s", strerror(errno));
-                if (fd > STDERR_FILENO)
-                        close(fd);
-        }
-
-        term = getenv("TERM");
-
-        flags = 0;
-        if (tty_flag)
-                flags |= SSHMUX_FLAG_TTY;
-        if (subsystem_flag)
-                flags |= SSHMUX_FLAG_SUBSYS;
-        if (options.forward_x11)
-                flags |= SSHMUX_FLAG_X11_FWD;
-        if (options.forward_agent)
-                flags |= SSHMUX_FLAG_AGENT_FWD;
-
-        buffer_init(&m);
-
-        /* Send our command to server */
-        buffer_put_int(&m, mux_command);
-        buffer_put_int(&m, flags);
-        if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
-                fatal("%s: msg_send", __func__);
-        buffer_clear(&m);
-
-        /* Get authorisation status and PID of controlee */
-        if (ssh_msg_recv(sock, &m) == -1)
-                fatal("%s: msg_recv", __func__);
-        if (buffer_get_char(&m) != SSHMUX_VER)
-                fatal("%s: wrong version", __func__);
-        if (buffer_get_int(&m) != 1)
-                fatal("Connection to master denied");
-        control_server_pid = buffer_get_int(&m);
-
-        buffer_clear(&m);
-
-        switch (mux_command) {
-        case SSHMUX_COMMAND_ALIVE_CHECK:
-                fprintf(stderr, "Master running (pid=%d)\r\n",
-                    control_server_pid);
-                exit(0);
-        case SSHMUX_COMMAND_TERMINATE:
-                fprintf(stderr, "Exit request sent.\r\n");
-                exit(0);
-        case SSHMUX_COMMAND_OPEN:
-                /* continue below */
-                break;
-        default:
-                fatal("silly mux_command %d", mux_command);
-        }
-
-        /* SSHMUX_COMMAND_OPEN */
-        buffer_put_cstring(&m, term ? term : "");
-        buffer_append(&command, "\0", 1);
-        buffer_put_cstring(&m, buffer_ptr(&command));
-
-        if (options.num_send_env == 0 || environ == NULL) {
-                buffer_put_int(&m, 0);
-        } else {
-                /* Pass environment */
-                num_env = 0;
-                for (i = 0; environ[i] != NULL; i++)
-                        if (env_permitted(environ[i]))
-                                num_env++; /* Count */
-
-                buffer_put_int(&m, num_env);
-
-                for (i = 0; environ[i] != NULL && num_env >= 0; i++)
-                        if (env_permitted(environ[i])) {
-                                num_env--;
-                                buffer_put_cstring(&m, environ[i]);
-                        }
-        }
-
-        if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
-                fatal("%s: msg_send", __func__);
-
-        mm_send_fd(sock, STDIN_FILENO);
-        mm_send_fd(sock, STDOUT_FILENO);
-        mm_send_fd(sock, STDERR_FILENO);
-
-        /* Wait for reply, so master has a chance to gather ttymodes */
-        buffer_clear(&m);
-        if (ssh_msg_recv(sock, &m) == -1)
-                fatal("%s: msg_recv", __func__);
-        if (buffer_get_char(&m) != SSHMUX_VER)
-                fatal("%s: wrong version", __func__);
-        buffer_free(&m);
-
-        signal(SIGHUP, control_client_sighandler);
-        signal(SIGINT, control_client_sighandler);
-        signal(SIGTERM, control_client_sighandler);
-        signal(SIGWINCH, control_client_sigrelay);
-
-        if (tty_flag)
-                enter_raw_mode();
-
-        /*
-         * Stick around until the controlee closes the client_fd.
-         * Before it does, it is expected to write this process' exit
-         * value (one int). This process must read the value and wait for
-         * the closure of the client_fd; if this one closes early, the 
-         * multiplex master will terminate early too (possibly losing data).
-         */
-        exitval[0] = 0;
-        for (i = 0; !control_client_terminate && i < (int)sizeof(exitval);) {
-                r = read(sock, (char *)exitval + i, sizeof(exitval) - i);
-                if (r == 0) {
-                        debug2("Received EOF from master");
-                        break;
-                }
-                if (r == -1) {
-                        if (errno == EINTR)
-                                continue;
-                        fatal("%s: read %s", __func__, strerror(errno));
-                }
-                i += r;
-        }
-
-        close(sock);
-        leave_raw_mode();
-        if (i > (int)sizeof(int))
-                fatal("%s: master returned too much data (%d > %lu)",
-                    __func__, i, sizeof(int));
-        if (control_client_terminate) {
-                debug2("Exiting on signal %d", control_client_terminate);
-                exitval[0] = 255;
-        } else if (i < (int)sizeof(int)) {
-                debug2("Control master terminated unexpectedly");
-                exitval[0] = 255;
-        } else
-                debug2("Received exit status from master %d", exitval[0]);
-
-        if (tty_flag && options.log_level > SYSLOG_LEVEL_QUIET)
-                fprintf(stderr, "Shared connection to %s closed.\r\n", host);
-
-        exit(exitval[0]);
+        bzero(pwname, strlen(pwname));
+        xfree(pwname);
+        bzero(pwdir, strlen(pwdir));
+        xfree(pwdir);
 }