tyler.durden
/
openssh-portable
mirror of https://github.com/PowerShell/openssh-portable.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

- djm@cvs.openbsd.org 2008/05/09 14:18:44 

[clientloop.c clientloop.h ssh.c mux.c]
     tidy up session multiplexing code, moving it into its own file and
     making the function names more consistent - making ssh.c and
     clientloop.c a fair bit more readable.
     ok markus@
This commit is contained in:
Damien Miller 2008-05-19 16:00:08 +10:00
parent bd74025c7b
commit b1cbfa25f1
6 changed files with 699 additions and 596 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
ChangeLog
View File

@ -111,6 +111,12 @@
was to try the first address and give up.
Reported by stig AT venaas.com in bz#343
great feedback and ok markus@
- djm@cvs.openbsd.org 2008/05/09 14:18:44
[clientloop.c clientloop.h ssh.c mux.c]
tidy up session multiplexing code, moving it into its own file and
making the function names more consistent - making ssh.c and
clientloop.c a fair bit more readable.
ok markus@
20080403
- (djm) [openbsd-compat/bsd-poll.c] Include stdlib.h to avoid compile-
@ -3971,4 +3977,4 @@
OpenServer 6 and add osr5bigcrypt support so when someone migrates
passwords between UnixWare and OpenServer they will still work. OK dtucker@
$Id: ChangeLog,v 1.4925 2008/05/19 05:37:09 djm Exp $
$Id: ChangeLog,v 1.4926 2008/05/19 06:00:08 djm Exp $

4
Makefile.in
View File

@ -1,4 +1,4 @@
# $Id: Makefile.in,v 1.289 2008/03/13 01:41:31 djm Exp $
# $Id: Makefile.in,v 1.290 2008/05/19 06:00:08 djm Exp $
# uncomment if you run a non bourne compatable shell. Ie. csh
#SHELL = @SH@
@ -74,7 +74,7 @@ LIBSSH_OBJS=acss.o authfd.o authfile.o bufaux.o bufbn.o buffer.o \
entropy.o scard-opensc.o gss-genr.o umac.o
SSHOBJS= ssh.o readconf.o clientloop.o sshtty.o \
sshconnect.o sshconnect1.o sshconnect2.o
sshconnect.o sshconnect1.o sshconnect2.o mux.o
SSHDOBJS=sshd.o auth-rhosts.o auth-passwd.o auth-rsa.o auth-rh-rsa.o \
sshpty.o sshlogin.o servconf.o serverloop.o \

308
clientloop.c
View File

@ -1,4 +1,4 @@
/* $OpenBSD: clientloop.c,v 1.191 2008/05/09 04:55:56 djm Exp $ */
/* $OpenBSD: clientloop.c,v 1.192 2008/05/09 14:18:44 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@ -121,7 +121,7 @@ extern int stdin_null_flag;
extern int no_shell_flag;
/* Control socket */
extern int control_fd;
extern int muxserver_sock;
/*
* Name of the host we are connecting to. This is the name given on the
@ -162,17 +162,6 @@ static int session_closed = 0; /* In SSH2: login session closed. */
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;
};
struct channel_reply_ctx {
const char *request_type;
int id, do_close;
@ -538,8 +527,8 @@ client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
if (packet_have_data_to_write())
FD_SET(connection_out, *writesetp);
if (control_fd != -1)
FD_SET(control_fd, *readsetp);
if (muxserver_sock != -1)
FD_SET(muxserver_sock, *readsetp);
/*
* Wait for something to happen. This will suspend the process until
@ -706,284 +695,6 @@ client_expect_confirm(int id, const char *request, int do_close)
client_abandon_status_confirm, cr);
}
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);
c->open_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, window, packetmax;
socklen_t addrlen;
struct sockaddr_storage addr;
struct confirm_ctx *cctx;
char *cmd;
u_int i, j, 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 */
for(i = 0; i < 3; i++) {
if ((new_fd[i] = mm_receive_fd(client_fd)) == -1) {
error("%s: failed to receive fd %d from slave",
__func__, i);
for (j = 0; j < i; j++)
close(new_fd[j]);
for (j = 0; j < env_len; j++)
xfree(cctx->env[j]);
if (env_len > 0)
xfree(cctx->env);
xfree(cctx->term);
buffer_free(&cctx->cmd);
close(client_fd);
xfree(cctx);
return;
}
}
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);
window = CHAN_SES_WINDOW_DEFAULT;
packetmax = CHAN_SES_PACKET_DEFAULT;
if (cctx->want_tty) {
window >>= 1;
packetmax >>= 1;
}
c = channel_new("session", SSH_CHANNEL_OPENING,
new_fd[0], new_fd[1], new_fd[2], window, packetmax,
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_open_confirm(c->self,
client_extra_session2_setup, cctx);
}
static void
process_cmdline(void)
{
@ -1448,8 +1159,8 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
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 (muxserver_sock != -1)
max_fd = MAX(max_fd, muxserver_sock);
if (!compat20) {
/* enable nonblocking unless tty */
@ -1569,7 +1280,10 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
client_process_net_input(readset);
/* Accept control connections. */
client_process_control(readset);
if (muxserver_sock != -1 &&FD_ISSET(muxserver_sock, readset)) {
if (muxserver_accept_control())
quit_pending = 1;
}
if (quit_pending)
break;
@ -2157,7 +1871,7 @@ cleanup_exit(int i)
{
leave_raw_mode();
leave_non_blocking();
if (options.control_path != NULL && control_fd != -1)
if (options.control_path != NULL && muxserver_sock != -1)
unlink(options.control_path);
_exit(i);
}

20
clientloop.h
View File

@ -1,4 +1,4 @@
/* $OpenBSD: clientloop.h,v 1.18 2008/05/08 13:06:11 djm Exp $ */
/* $OpenBSD: clientloop.h,v 1.19 2008/05/09 14:18:44 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
@ -58,3 +58,21 @@ int client_request_tun_fwd(int, int, int);
#define SSHMUX_FLAG_SUBSYS (1<<1) /* Subsystem request on open */
#define SSHMUX_FLAG_X11_FWD (1<<2) /* Request X11 forwarding */
#define SSHMUX_FLAG_AGENT_FWD (1<<3) /* Request agent forwarding */
/* Multiplexing routines */
struct mux_session_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;
};
/* mux.c */
void muxserver_listen(void);
int muxserver_accept_control(void);
void muxclient(const char *);

646
mux.c Normal file
View File

@ -0,0 +1,646 @@
/* $OpenBSD: mux.c,v 1.1 2008/05/09 14:18:44 djm Exp $ */
/*
* Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* ssh session multiplexing support */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <util.h>
#include <paths.h>
#include "openbsd-compat/sys-queue.h"
#include "xmalloc.h"
#include "log.h"
#include "ssh.h"
#include "pathnames.h"
#include "misc.h"
#include "match.h"
#include "buffer.h"
#include "channels.h"
#include "msg.h"
#include "packet.h"
#include "monitor_fdpass.h"
#include "sshpty.h"
#include "key.h"
#include "readconf.h"
#include "clientloop.h"
/* from ssh.c */
extern int tty_flag;
extern Options options;
extern int stdin_null_flag;
extern char *host;
int subsystem_flag;
extern Buffer command;
/* fd to control socket */
int muxserver_sock = -1;
/* Multiplexing control command */
u_int muxclient_command = 0;
/* Set when signalled. */
static volatile sig_atomic_t muxclient_terminate = 0;
/* PID of multiplex server */
static u_int muxserver_pid = 0;
/* ** Multiplexing master support */
/* Prepare a mux master to listen on a Unix domain socket. */
void
muxserver_listen(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 ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
fatal("%s socket(): %s", __func__, strerror(errno));
old_umask = umask(0177);
if (bind(muxserver_sock, (struct sockaddr *)&addr, addr_len) == -1) {
muxserver_sock = -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(muxserver_sock, 64) == -1)
fatal("%s listen(): %s", __func__, strerror(errno));
set_nonblock(muxserver_sock);
}
/* Callback on open confirmation in mux master for a mux client session. */
static void
client_extra_session2_setup(int id, void *arg)
{
struct mux_session_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);
c->open_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);
}
/*
* Accept a connection on the mux master socket and process the
* client's request. Returns flag indicating whether mux master should
* begin graceful close.
*/
int
muxserver_accept_control(void)
{
Buffer m;
Channel *c;
int client_fd, new_fd[3], ver, allowed, window, packetmax;
socklen_t addrlen;
struct sockaddr_storage addr;
struct mux_session_confirm_ctx *cctx;
char *cmd;
u_int i, j, len, env_len, mux_command, flags;
uid_t euid;
gid_t egid;
int start_close = 0;
/*
* Accept connection on control socket
*/
memset(&addr, 0, sizeof(addr));
addrlen = sizeof(addr);
if ((client_fd = accept(muxserver_sock,
(struct sockaddr*)&addr, &addrlen)) == -1) {
error("%s accept: %s", __func__, strerror(errno));
return 0;
}
if (getpeereid(client_fd, &euid, &egid) < 0) {
error("%s getpeereid failed: %s", __func__, strerror(errno));
close(client_fd);
return 0;
}
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 0;
}
/* XXX handle asynchronously */
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 0;
}
if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
error("%s: wrong client version %d", __func__, ver);
buffer_free(&m);
close(client_fd);
return 0;
}
allowed = 1;
mux_command = buffer_get_int(&m);
flags = buffer_get_int(&m);
buffer_clear(&m);
switch (mux_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)
start_close = 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 start_close;
}
buffer_free(&m);
close(client_fd);
return start_close;
default:
error("Unsupported command %d", mux_command);
buffer_free(&m);
close(client_fd);
return 0;
}
/* 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 0;
}
if (!allowed) {
error("Refused control connection");
close(client_fd);
buffer_free(&m);
return 0;
}
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 0;
}
if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
error("%s: wrong client version %d", __func__, ver);
buffer_free(&m);
close(client_fd);
return 0;
}
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 */
for(i = 0; i < 3; i++) {
if ((new_fd[i] = mm_receive_fd(client_fd)) == -1) {
error("%s: failed to receive fd %d from slave",
__func__, i);
for (j = 0; j < i; j++)
close(new_fd[j]);
for (j = 0; j < env_len; j++)
xfree(cctx->env[j]);
if (env_len > 0)
xfree(cctx->env);
xfree(cctx->term);
buffer_free(&cctx->cmd);
close(client_fd);
xfree(cctx);
return 0;
}
}
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 0;
}
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);
window = CHAN_SES_WINDOW_DEFAULT;
packetmax = CHAN_SES_PACKET_DEFAULT;
if (cctx->want_tty) {
window >>= 1;
packetmax >>= 1;
}
c = channel_new("session", SSH_CHANNEL_OPENING,
new_fd[0], new_fd[1], new_fd[2], window, packetmax,
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_open_confirm(c->self,
client_extra_session2_setup, cctx);
return 0;
}
/* ** Multiplexing client support */
/* Exit signal handler */
static void
control_client_sighandler(int signo)
{
muxclient_terminate = signo;
}
/*
* Relay signal handler - used to pass some signals from mux client to
* mux master.
*/
static void
control_client_sigrelay(int signo)
{
int save_errno = errno;
if (muxserver_pid > 1)
kill(muxserver_pid, signo);
errno = save_errno;
}
/* Check mux client environment variables before passing them to mux master. */
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);
}
/* Multiplex client main loop. */
void
muxclient(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 (muxclient_command == 0)
muxclient_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 (muxclient_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;
signal(SIGPIPE, SIG_IGN);
buffer_init(&m);
/* Send our command to server */
buffer_put_int(&m, muxclient_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");
muxserver_pid = buffer_get_int(&m);
buffer_clear(&m);
switch (muxclient_command) {
case SSHMUX_COMMAND_ALIVE_CHECK:
fprintf(stderr, "Master running (pid=%d)\r\n",
muxserver_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 muxclient_command %d", muxclient_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__);
if (mm_send_fd(sock, STDIN_FILENO) == -1 ||
mm_send_fd(sock, STDOUT_FILENO) == -1 ||
mm_send_fd(sock, STDERR_FILENO) == -1)
fatal("%s: send fds failed", __func__);
/* 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; !muxclient_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 (muxclient_terminate) {
debug2("Exiting on signal %d", muxclient_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]);
}

309
ssh.c
View File

@ -1,4 +1,4 @@
/* $OpenBSD: ssh.c,v 1.311 2008/05/08 13:06:11 djm Exp $ */
/* $OpenBSD: ssh.c,v 1.312 2008/05/09 14:18:44 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>
@ -99,7 +98,6 @@
#include "sshpty.h"
#include "match.h"
#include "msg.h"
#include "monitor_fdpass.h"
#include "uidswap.h"
#include "version.h"
@ -171,15 +169,9 @@ static int client_global_request_id = 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. */
@ -200,7 +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.
@ -310,9 +305,9 @@ 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;
@ -683,10 +678,10 @@ main(int ac, char **av)
"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;
@ -809,7 +804,7 @@ 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);
/*
@ -1064,48 +1059,6 @@ client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt)
}
}
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)
@ -1204,7 +1157,7 @@ ssh_session2(void)
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)
@ -1272,237 +1225,3 @@ load_public_identity_files(void)
bzero(pwdir, strlen(pwdir));
xfree(pwdir);
}
static void
control_client_sighandler(int signo)
{
control_client_terminate = signo;
}
static void
control_client_sigrelay(int signo)
{
int save_errno = errno;
if (control_server_pid > 1)
kill(control_server_pid, signo);
errno = save_errno;
}
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;
signal(SIGPIPE, SIG_IGN);
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__);
if (mm_send_fd(sock, STDIN_FILENO) == -1 ||
mm_send_fd(sock, STDOUT_FILENO) == -1 ||
mm_send_fd(sock, STDERR_FILENO) == -1)
fatal("%s: send fds failed", __func__);
/* 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]);
}