+/* $OpenBSD: clientloop.c,v 1.173 2006/07/26 13:57:17 stevesk Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
*/
#include "includes.h"
-RCSID("$OpenBSD: clientloop.c,v 1.132 2004/10/29 21:47:15 djm Exp $");
+
+#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 <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
#include "ssh.h"
#include "ssh1.h"
#include "log.h"
#include "readconf.h"
#include "clientloop.h"
+#include "sshconnect.h"
#include "authfd.h"
#include "atomicio.h"
#include "sshpty.h"
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. */
+/* 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 int quit_pending; /* Set to non-zero to quit the client loop. */
+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. */
struct confirm_ctx {
int want_tty;
int want_subsys;
+ int want_x_fwd;
+ int want_agent_fwd;
Buffer cmd;
char *term;
struct termios tio;
* 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)
{
* 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)
{
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
if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
return;
packet_start(SSH_CMSG_WINDOW_SIZE);
- packet_put_int(ws.ws_row);
- packet_put_int(ws.ws_col);
- packet_put_int(ws.ws_xpixel);
- packet_put_int(ws.ws_ypixel);
+ 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_process_net_input(fd_set * readset)
+client_process_net_input(fd_set *readset)
{
int len;
char buf[8192];
client_extra_session2_setup(int id, void *arg)
{
struct confirm_ctx *cctx = arg;
+ const char *display;
Channel *c;
int i;
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);
}
static void
-client_process_control(fd_set * readset)
+client_process_control(fd_set *readset)
{
Buffer m;
Channel *c;
- int client_fd, new_fd[3], ver, i, allowed;
+ int client_fd, new_fd[3], ver, allowed;
socklen_t addrlen;
struct sockaddr_storage addr;
struct confirm_ctx *cctx;
char *cmd;
- u_int len, env_len;
+ u_int i, len, env_len, command, flags;
uid_t euid;
gid_t egid;
return;
}
- allowed = 1;
- if (options.control_master == 2) {
- char *p, prompt[1024];
-
- allowed = 0;
- snprintf(prompt, sizeof(prompt),
- "Allow shared connection to %s? ", host);
- p = read_passphrase(prompt, RP_USE_ASKPASS|RP_ALLOW_EOF);
- if (p != NULL) {
- /*
- * Accept empty responses and responses consisting
- * of the word "yes" as affirmative.
- */
- if (*p == '\0' || *p == '\n' ||
- strcasecmp(p, "yes") == 0)
- allowed = 1;
- xfree(p);
- }
- }
-
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, /* version */0, &m) == -1) {
+ 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_clear(&m);
if (!allowed) {
error("Refused control connection");
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)) != 0) {
+ if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
error("%s: wrong client version %d", __func__, ver);
buffer_free(&m);
close(client_fd);
return;
}
- cctx = xmalloc(sizeof(*cctx));
- memset(cctx, 0, sizeof(*cctx));
-
- cctx->want_tty = buffer_get_int(&m);
- cctx->want_subsys = buffer_get_int(&m);
+ 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);
env_len = MIN(env_len, 4096);
debug3("%s: receiving %d env vars", __func__, env_len);
if (env_len != 0) {
- cctx->env = xmalloc(sizeof(*cctx->env) * (env_len + 1));
+ 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);
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, /* version */0, &m) == -1) {
+ 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);
process_cmdline(void)
{
void (*handler)(int);
- char *s, *cmd;
- u_short fwd_port, fwd_host_port;
- char buf[1024], sfwd_port[6], sfwd_host_port[6];
+ 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);
if (*s == 'h' || *s == 'H' || *s == '?') {
logit("Commands:");
- logit(" -Lport:host:hostport Request local forward");
- logit(" -Rport:host:hostport Request remote forward");
- logit(" -KRhostport Cancel remote forward");
+ 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;
}
s++;
if (delete) {
- if (sscanf(s, "%5[0-9]", sfwd_host_port) != 1) {
- logit("Bad forwarding specification.");
- goto out;
+ 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 ((fwd_host_port = a2port(sfwd_host_port)) == 0) {
- logit("Bad forwarding port(s).");
+ if (cancel_port == 0) {
+ logit("Bad forwarding close port");
goto out;
}
- channel_request_rforward_cancel(fwd_host_port);
+ channel_request_rforward_cancel(cancel_host, cancel_port);
} else {
- if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
- sfwd_port, buf, sfwd_host_port) != 3 &&
- sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
- sfwd_port, buf, sfwd_host_port) != 3) {
+ if (!parse_forward(&fwd, s)) {
logit("Bad forwarding specification.");
goto out;
}
- if ((fwd_port = a2port(sfwd_port)) == 0 ||
- (fwd_host_port = a2port(sfwd_host_port)) == 0) {
- logit("Bad forwarding port(s).");
- goto out;
- }
if (local) {
- if (channel_setup_local_fwd_listener(fwd_port, buf,
- fwd_host_port, options.gateway_ports) < 0) {
+ 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;
}
- } else
- channel_request_remote_forwarding(fwd_port, buf,
- fwd_host_port);
+ }
+
logit("Forwarding port.");
}
u_char ch;
char *s;
- for (i = 0; i < len; i++) {
+ if (len <= 0)
+ return (0);
+
+ for (i = 0; i < (u_int)len; i++) {
/* Get one character at a time. */
ch = buf[i];
}
static void
-client_process_input(fd_set * readset)
+client_process_input(fd_set *readset)
{
int len;
char buf[8192];
}
static void
-client_process_output(fd_set * writeset)
+client_process_output(fd_set *writeset)
{
int len;
char buf[100];
session_ident = ssh2_chan_id;
if (escape_char != SSH_ESCAPECHAR_NONE)
channel_register_filter(session_ident,
- simple_escape_filter);
+ simple_escape_filter, NULL);
if (session_ident != -1)
channel_register_cleanup(session_ident,
- client_channel_closed);
+ client_channel_closed, 0);
} else {
/* Check if we should immediately send eof on stdin. */
client_check_initial_eof_on_stdin();
if (!options.forward_x11) {
error("Warning: ssh server tried X11 forwarding.");
- error("Warning: this is probably a break in attempt by a malicious server.");
+ error("Warning: this is probably a break-in attempt by a malicious server.");
return NULL;
}
originator = packet_get_string(NULL);
if (!options.forward_agent) {
error("Warning: ssh server tried agent forwarding.");
- error("Warning: this is probably a break in attempt by a malicious server.");
+ error("Warning: this is probably a break-in attempt by a malicious server.");
return NULL;
}
sock = ssh_get_authentication_socket();
channel_request_start(id, "pty-req", 0);
packet_put_cstring(term != NULL ? term : "");
- packet_put_int(ws.ws_col);
- packet_put_int(ws.ws_row);
- packet_put_int(ws.ws_xpixel);
- packet_put_int(ws.ws_ypixel);
+ 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();
/* Split */
name = xstrdup(env[i]);
if ((val = strchr(name, '=')) == NULL) {
- free(name);
+ xfree(name);
continue;
}
*val++ = '\0';
}
if (!matched) {
debug3("Ignored env %s", name);
- free(name);
+ xfree(name);
continue;
}
packet_put_cstring(name);
packet_put_cstring(val);
packet_send();
- free(name);
+ xfree(name);
}
}
andersk / openssh.git / blobdiff