- djm@cvs.openbsd.org 2008/06/12 03:40:52
[clientloop.h mux.c channels.c clientloop.c channels.h]
Enable ~ escapes for multiplex slave sessions; give each channel
its own escape state and hook the escape filters up to muxed
channels. bz #1331
Mux slaves do not currently support the ~^Z and ~& escapes.
NB. this change cranks the mux protocol version, so a new ssh
mux client will not be able to connect to a running old ssh
mux master.
ok dtucker@
diff --git a/clientloop.c b/clientloop.c
index 3bc8bb8..b45e729 100644
--- a/clientloop.c
+++ b/clientloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.194 2008/05/19 20:53:52 djm Exp $ */
+/* $OpenBSD: clientloop.c,v 1.195 2008/06/12 03:40:52 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -144,8 +144,8 @@
/* Common data for the client loop code. */
static volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
-static int escape_char; /* Escape character. */
-static int escape_pending; /* Last character was the escape character */
+static int escape_char1; /* Escape character. (proto1 only) */
+static int escape_pending1; /* Last character was an escape (proto1 only) */
static int last_was_cr; /* Last character was a newline. */
static int exit_status; /* Used to store the exit status of the command. */
static int stdin_eof; /* EOF has been encountered on standard error. */
@@ -162,6 +162,13 @@
static void client_init_dispatch(void);
int session_ident = -1;
+/* Track escape per proto2 channel */
+struct escape_filter_ctx {
+ int escape_pending;
+ int escape_char;
+};
+
+/* Context for channel confirmation replies */
struct channel_reply_ctx {
const char *request_type;
int id, do_close;
@@ -385,8 +392,8 @@
* and also process it as an escape character if
* appropriate.
*/
- if ((u_char) buf[0] == escape_char)
- escape_pending = 1;
+ if ((u_char) buf[0] == escape_char1)
+ escape_pending1 = 1;
else
buffer_append(&stdin_buffer, buf, 1);
}
@@ -813,9 +820,12 @@
xfree(fwd.connect_host);
}
-/* process the characters one by one */
+/*
+ * Process the characters one by one, call with c==NULL for proto1 case.
+ */
static int
-process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
+process_escapes(Channel *c, Buffer *bin, Buffer *bout, Buffer *berr,
+ char *buf, int len)
{
char string[1024];
pid_t pid;
@@ -823,7 +833,20 @@
u_int i;
u_char ch;
char *s;
+ int *escape_pendingp, escape_char;
+ struct escape_filter_ctx *efc;
+ if (c == NULL) {
+ escape_pendingp = &escape_pending1;
+ escape_char = escape_char1;
+ } else {
+ if (c->filter_ctx == NULL)
+ return 0;
+ efc = (struct escape_filter_ctx *)c->filter_ctx;
+ escape_pendingp = &efc->escape_pending;
+ escape_char = efc->escape_char;
+ }
+
if (len <= 0)
return (0);
@@ -831,25 +854,43 @@
/* Get one character at a time. */
ch = buf[i];
- if (escape_pending) {
+ if (*escape_pendingp) {
/* We have previously seen an escape character. */
/* Clear the flag now. */
- escape_pending = 0;
+ *escape_pendingp = 0;
/* Process the escaped character. */
switch (ch) {
case '.':
/* Terminate the connection. */
- snprintf(string, sizeof string, "%c.\r\n", escape_char);
+ snprintf(string, sizeof string, "%c.\r\n",
+ escape_char);
buffer_append(berr, string, strlen(string));
- quit_pending = 1;
+ if (c && c->ctl_fd != -1) {
+ chan_read_failed(c);
+ chan_write_failed(c);
+ return 0;
+ } else
+ quit_pending = 1;
return -1;
case 'Z' - 64:
+ /* XXX support this for mux clients */
+ if (c && c->ctl_fd != -1) {
+ noescape:
+ snprintf(string, sizeof string,
+ "%c%c escape not available to "
+ "multiplexed sessions\r\n",
+ escape_char, ch);
+ buffer_append(berr, string,
+ strlen(string));
+ continue;
+ }
/* Suspend the program. */
/* Print a message to that effect to the user. */
- snprintf(string, sizeof string, "%c^Z [suspend ssh]\r\n", escape_char);
+ snprintf(string, sizeof string,
+ "%c^Z [suspend ssh]\r\n", escape_char);
buffer_append(berr, string, strlen(string));
/* Restore terminal modes and suspend. */
@@ -881,6 +922,8 @@
continue;
case '&':
+ if (c && c->ctl_fd != -1)
+ goto noescape;
/*
* Detach the program (continue to serve connections,
* but put in background and no more new connections).
@@ -929,27 +972,50 @@
continue;
case '?':
- snprintf(string, sizeof string,
+ if (c && c->ctl_fd != -1) {
+ snprintf(string, sizeof string,
"%c?\r\n\
Supported escape sequences:\r\n\
-%c. - terminate connection\r\n\
-%cB - send a BREAK to the remote system\r\n\
-%cC - open a command line\r\n\
-%cR - Request rekey (SSH protocol 2 only)\r\n\
-%c^Z - suspend ssh\r\n\
-%c# - list forwarded connections\r\n\
-%c& - background ssh (when waiting for connections to terminate)\r\n\
-%c? - this message\r\n\
-%c%c - send the escape character by typing it twice\r\n\
+ %c. - terminate session\r\n\
+ %cB - send a BREAK to the remote system\r\n\
+ %cC - open a command line\r\n\
+ %cR - Request rekey (SSH protocol 2 only)\r\n\
+ %c# - list forwarded connections\r\n\
+ %c? - this message\r\n\
+ %c%c - send the escape character by typing it twice\r\n\
(Note that escapes are only recognized immediately after newline.)\r\n",
- escape_char, escape_char, escape_char, escape_char,
- escape_char, escape_char, escape_char, escape_char,
- escape_char, escape_char, escape_char);
+ escape_char, escape_char,
+ escape_char, escape_char,
+ escape_char, escape_char,
+ escape_char, escape_char,
+ escape_char);
+ } else {
+ snprintf(string, sizeof string,
+"%c?\r\n\
+Supported escape sequences:\r\n\
+ %c. - terminate connection (and any multiplexed sessions)\r\n\
+ %cB - send a BREAK to the remote system\r\n\
+ %cC - open a command line\r\n\
+ %cR - Request rekey (SSH protocol 2 only)\r\n\
+ %c^Z - suspend ssh\r\n\
+ %c# - list forwarded connections\r\n\
+ %c& - background ssh (when waiting for connections to terminate)\r\n\
+ %c? - this message\r\n\
+ %c%c - send the escape character by typing it twice\r\n\
+(Note that escapes are only recognized immediately after newline.)\r\n",
+ escape_char, escape_char,
+ escape_char, escape_char,
+ escape_char, escape_char,
+ escape_char, escape_char,
+ escape_char, escape_char,
+ escape_char);
+ }
buffer_append(berr, string, strlen(string));
continue;
case '#':
- snprintf(string, sizeof string, "%c#\r\n", escape_char);
+ snprintf(string, sizeof string, "%c#\r\n",
+ escape_char);
buffer_append(berr, string, strlen(string));
s = channel_open_message();
buffer_append(berr, s, strlen(s));
@@ -975,7 +1041,7 @@
*/
if (last_was_cr && ch == escape_char) {
/* It is. Set the flag and continue to next character. */
- escape_pending = 1;
+ *escape_pendingp = 1;
continue;
}
}
@@ -1026,7 +1092,7 @@
packet_start(SSH_CMSG_EOF);
packet_send();
}
- } else if (escape_char == SSH_ESCAPECHAR_NONE) {
+ } else if (escape_char1 == SSH_ESCAPECHAR_NONE) {
/*
* Normal successful read, and no escape character.
* Just append the data to buffer.
@@ -1037,8 +1103,8 @@
* Normal, successful read. But we have an escape character
* and have to process the characters one by one.
*/
- if (process_escapes(&stdin_buffer, &stdout_buffer,
- &stderr_buffer, buf, len) == -1)
+ if (process_escapes(NULL, &stdin_buffer,
+ &stdout_buffer, &stderr_buffer, buf, len) == -1)
return;
}
}
@@ -1113,13 +1179,26 @@
/* scan buf[] for '~' before sending data to the peer */
-static int
-simple_escape_filter(Channel *c, char *buf, int len)
+/* Helper: allocate a new escape_filter_ctx and fill in its escape char */
+void *
+client_new_escape_filter_ctx(int escape_char)
+{
+ struct escape_filter_ctx *ret;
+
+ ret = xmalloc(sizeof(*ret));
+ ret->escape_pending = 0;
+ ret->escape_char = escape_char;
+ return (void *)ret;
+}
+
+int
+client_simple_escape_filter(Channel *c, char *buf, int len)
{
if (c->extended_usage != CHAN_EXTENDED_WRITE)
return 0;
- return process_escapes(&c->input, &c->output, &c->extended, buf, len);
+ return process_escapes(c, &c->input, &c->output, &c->extended,
+ buf, len);
}
static void
@@ -1151,7 +1230,7 @@
start_time = get_current_time();
/* Initialize variables. */
- escape_pending = 0;
+ escape_pending1 = 0;
last_was_cr = 1;
exit_status = -1;
stdin_eof = 0;
@@ -1178,7 +1257,7 @@
stdout_bytes = 0;
stderr_bytes = 0;
quit_pending = 0;
- escape_char = escape_char_arg;
+ escape_char1 = escape_char_arg;
/* Initialize buffers. */
buffer_init(&stdin_buffer);
@@ -1206,9 +1285,10 @@
if (compat20) {
session_ident = ssh2_chan_id;
- if (escape_char != SSH_ESCAPECHAR_NONE)
+ if (escape_char_arg != SSH_ESCAPECHAR_NONE)
channel_register_filter(session_ident,
- simple_escape_filter, NULL);
+ client_simple_escape_filter, NULL,
+ client_new_escape_filter_ctx(escape_char_arg));
if (session_ident != -1)
channel_register_cleanup(session_ident,
client_channel_closed, 0);