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/* RCSID("$Id: channels.h,v 1.5 2000/04/01 01:09:23 damien Exp $"); */
#ifndef CHANNELS_H
#define CHANNELS_H
/* Definitions for channel types. */
#define SSH_CHANNEL_FREE 0 /* This channel is free (unused). */
#define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
#define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */
#define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */
#define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */
#define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
#define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */
#define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */
#define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */
#define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */
#define SSH_CHANNEL_LARVAL 10 /* larval session */
#define SSH_CHANNEL_MAX_TYPE 11
/*
* Data structure for channel data. This is iniailized in channel_allocate
* and cleared in channel_free.
*/
typedef void channel_callback_fn(int id, void *arg);
typedef struct Channel {
int type; /* channel type/state */
int self; /* my own channel identifier */
int remote_id; /* channel identifier for remote peer */
/* peer can be reached over encrypted connection, via packet-sent */
int istate; /* input from channel (state of receive half) */
int ostate; /* output to channel (state of transmit half) */
int rfd; /* read fd */
int wfd; /* write fd */
int efd; /* extended fd */
int sock; /* sock fd */
Buffer input; /* data read from socket, to be sent over
* encrypted connection */
Buffer output; /* data received over encrypted connection for
* send on socket */
Buffer extended;
char path[200]; /* path for unix domain sockets, or host name
* for forwards */
int listening_port; /* port being listened for forwards */
int host_port; /* remote port to connect for forwards */
char *remote_name; /* remote hostname */
int remote_window;
int remote_maxpacket;
int local_window;
int local_window_max;
int local_consumed;
int local_maxpacket;
int extended_usage;
char *ctype; /* type */
// callback
channel_callback_fn *cb_fn;
void *cb_arg;
int cb_event;
channel_callback_fn *dettach_user;
} Channel;
#define CHAN_EXTENDED_IGNORE 0
#define CHAN_EXTENDED_READ 1
#define CHAN_EXTENDED_WRITE 2
void channel_open(int id);
Channel *channel_lookup(int id);
int
channel_new(char *ctype, int type, int rfd, int wfd, int efd,
int window, int maxpack, int extended_usage, char *remote_name);
void channel_input_close(int type, int plen);
void channel_input_close_confirmation(int type, int plen);
void channel_input_data(int type, int plen);
void channel_input_ieof(int type, int plen);
void channel_input_oclose(int type, int plen);
void channel_input_open_confirmation(int type, int plen);
void channel_input_open_failure(int type, int plen);
void channel_input_port_open(int type, int plen);
void channel_input_open(int type, int plen);
/* Sets specific protocol options. */
void channel_set_options(int hostname_in_open);
/*
* Allocate a new channel object and set its type and socket. Remote_name
* must have been allocated with xmalloc; this will free it when the channel
* is freed.
*/
int channel_allocate(int type, int sock, char *remote_name);
/* Free the channel and close its socket. */
void channel_free(int channel);
/* Add any bits relevant to channels in select bitmasks. */
void channel_prepare_select(fd_set * readset, fd_set * writeset);
/*
* After select, perform any appropriate operations for channels which have
* events pending.
*/
void channel_after_select(fd_set * readset, fd_set * writeset);
/* If there is data to send to the connection, send some of it now. */
void channel_output_poll(void);
/* Returns true if no channel has too much buffered data. */
int channel_not_very_much_buffered_data(void);
/* This closes any sockets that are listening for connections; this removes
any unix domain sockets. */
void channel_stop_listening(void);
/*
* Closes the sockets of all channels. This is used to close extra file
* descriptors after a fork.
*/
void channel_close_all(void);
/* Returns the maximum file descriptor number used by the channels. */
int channel_max_fd(void);
/* Returns true if there is still an open channel over the connection. */
int channel_still_open(void);
/*
* Returns a string containing a list of all open channels. The list is
* suitable for displaying to the user. It uses crlf instead of newlines.
* The caller should free the string with xfree.
*/
char *channel_open_message(void);
/*
* Initiate forwarding of connections to local port "port" through the secure
* channel to host:port from remote side. This never returns if there was an
* error.
*/
void
channel_request_local_forwarding(u_short port, const char *host,
u_short remote_port, int gateway_ports);
/*
* Initiate forwarding of connections to port "port" on remote host through
* the secure channel to host:port from local side. This never returns if
* there was an error. This registers that open requests for that port are
* permitted.
*/
void
channel_request_remote_forwarding(u_short port, const char *host,
u_short remote_port);
/*
* Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually
* called by the server, because the user could connect to any port anyway,
* and the server has no way to know but to trust the client anyway.
*/
void channel_permit_all_opens(void);
/*
* This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
* listening for the port, and sends back a success reply (or disconnect
* message if there was an error). This never returns if there was an error.
*/
void channel_input_port_forward_request(int is_root);
/*
* Creates a port for X11 connections, and starts listening for it. Returns
* the display name, or NULL if an error was encountered.
*/
char *x11_create_display(int screen);
/*
* Creates an internet domain socket for listening for X11 connections.
* Returns a suitable value for the DISPLAY variable, or NULL if an error
* occurs.
*/
char *x11_create_display_inet(int screen, int x11_display_offset);
/*
* This is called when SSH_SMSG_X11_OPEN is received. The packet contains
* the remote channel number. We should do whatever we want, and respond
* with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
*/
void x11_input_open(int type, int plen);
/*
* Requests forwarding of X11 connections. This should be called on the
* client only.
*/
void x11_request_forwarding(void);
/*
* Requests forwarding for X11 connections, with authentication spoofing.
* This should be called in the client only.
*/
void x11_request_forwarding_with_spoofing(const char *proto, const char *data);
/* Sends a message to the server to request authentication fd forwarding. */
void auth_request_forwarding(void);
/*
* Returns the name of the forwarded authentication socket. Returns NULL if
* there is no forwarded authentication socket. The returned value points to
* a static buffer.
*/
char *auth_get_socket_name(void);
/*
* This if called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
* This starts forwarding authentication requests.
*/
void auth_input_request_forwarding(struct passwd * pw);
/* This is called to process an SSH_SMSG_AGENT_OPEN message. */
void auth_input_open_request(int type, int plen);
#endif
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