- djm@cvs.openbsd.org 2010/01/26 01:28:35
[channels.c channels.h clientloop.c clientloop.h mux.c nchan.c ssh.c]
rewrite ssh(1) multiplexing code to a more sensible protocol.
The new multiplexing code uses channels for the listener and
accepted control sockets to make the mux master non-blocking, so
no stalls when processing messages from a slave.
avoid use of fatal() in mux master protocol parsing so an errant slave
process cannot take down a running master.
implement requesting of port-forwards over multiplexed sessions. Any
port forwards requested by the slave are added to those the master has
established.
add support for stdio forwarding ("ssh -W host:port ...") in mux slaves.
document master/slave mux protocol so that other tools can use it to
control a running ssh(1). Note: there are no guarantees that this
protocol won't be incompatibly changed (though it is versioned).
feedback Salvador Fandino, dtucker@
channel changes ok markus@
diff --git a/channels.h b/channels.h
index 79ebe04..cc71885 100644
--- a/channels.h
+++ b/channels.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: channels.h,v 1.102 2010/01/11 01:39:46 dtucker Exp $ */
+/* $OpenBSD: channels.h,v 1.103 2010/01/26 01:28:35 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -53,7 +53,9 @@
#define SSH_CHANNEL_CONNECTING 12
#define SSH_CHANNEL_DYNAMIC 13
#define SSH_CHANNEL_ZOMBIE 14 /* Almost dead. */
-#define SSH_CHANNEL_MAX_TYPE 15
+#define SSH_CHANNEL_MUX_LISTENER 15 /* Listener for mux conn. */
+#define SSH_CHANNEL_MUX_CLIENT 16 /* Conn. to mux slave */
+#define SSH_CHANNEL_MAX_TYPE 17
struct Channel;
typedef struct Channel Channel;
@@ -81,6 +83,9 @@
struct addrinfo *ai, *aitop;
};
+/* Callbacks for mux channels back into client-specific code */
+typedef int mux_callback_fn(struct Channel *);
+
struct Channel {
int type; /* channel type/state */
int self; /* my own channel identifier */
@@ -92,7 +97,7 @@
int wfd; /* write fd */
int efd; /* extended fd */
int sock; /* sock fd */
- int ctl_fd; /* control fd (client sharing) */
+ int ctl_chan; /* control channel (multiplexed connections) */
int isatty; /* rfd is a tty */
int wfd_isatty; /* wfd is a tty */
int client_tty; /* (client) TTY has been requested */
@@ -142,6 +147,10 @@
/* non-blocking connect */
struct channel_connect connect_ctx;
+
+ /* multiplexing protocol hook, called for each packet received */
+ mux_callback_fn *mux_rcb;
+ void *mux_ctx;
};
#define CHAN_EXTENDED_IGNORE 0
@@ -172,6 +181,7 @@
#define CHAN_CLOSE_RCVD 0x02
#define CHAN_EOF_SENT 0x04
#define CHAN_EOF_RCVD 0x08
+#define CHAN_LOCAL 0x10
#define CHAN_RBUF 16*1024
@@ -243,7 +253,7 @@
void channel_print_adm_permitted_opens(void);
int channel_input_port_forward_request(int, int);
Channel *channel_connect_to(const char *, u_short, char *, char *);
-Channel *channel_connect_stdio_fwd(const char*, u_short);
+Channel *channel_connect_stdio_fwd(const char*, u_short, int, int);
Channel *channel_connect_by_listen_address(u_short, char *, char *);
int channel_request_remote_forwarding(const char *, u_short,
const char *, u_short);