[openssh.git] / channels.h

/* RCSID("$OpenBSD: channels.h,v 1.16 2000/08/19 21:55:51 markus 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.
 */
struct Channel;
typedef struct Channel Channel;

typedef void channel_callback_fn(int id, void *arg);
typedef int channel_filter_fn(struct Channel *c, char *buf, int len);

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     flags;		/* close sent/rcvd */
	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;

	/* filter */
	channel_filter_fn	*input_filter;
};

#define CHAN_EXTENDED_IGNORE		0
#define CHAN_EXTENDED_READ		1
#define CHAN_EXTENDED_WRITE		2

void	channel_set_fds(int id, int rfd, int wfd, int efd, int extusage);
void	channel_open(int id);
void	channel_request(int id, char *service, int wantconfirm);
void	channel_request_start(int id, char *service, int wantconfirm);
void	channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg);
void	channel_register_cleanup(int id, channel_callback_fn *fn);
void	channel_register_filter(int id, channel_filter_fn *fn);
void	channel_cancel_cleanup(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_channel_request(int type, int plen);
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_extended_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_window_adjust(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, int gateway_ports);

/*
 * 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(int client_session_id,
    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 is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
 * This starts forwarding authentication requests.
 */
int     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);

/* XXX */
int	channel_connect_to(const char *host, u_short host_port);
int	x11_connect_display(void);

#endif
Commit	Line	Data
2e73a022	1	/* RCSID("$OpenBSD: channels.h,v 1.16 2000/08/19 21:55:51 markus Exp $"); */
8efc0c15	2
	3	#ifndef CHANNELS_H
	4	#define CHANNELS_H
	5
	6	/* Definitions for channel types. */
aa3378df	7	#define SSH_CHANNEL_FREE 0 /* This channel is free (unused). */
aa3378df	8	#define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
5260325f	9	#define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */
	10	#define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */
	11	#define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */
aa3378df	12	#define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
7368a6c8	13	#define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */
	14	#define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */
	15	#define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */
	16	#define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */
	17	#define SSH_CHANNEL_LARVAL 10 /* larval session */
	18	#define SSH_CHANNEL_MAX_TYPE 11
8efc0c15	19
aa3378df	20	/*
	21	* Data structure for channel data. This is iniailized in channel_allocate
	22	* and cleared in channel_free.
	23	*/
2e73a022	24	struct Channel;
	25	typedef struct Channel Channel;
	26
7368a6c8	27	typedef void channel_callback_fn(int id, void *arg);
2e73a022	28	typedef int channel_filter_fn(struct Channel c, char buf, int len);
8efc0c15	29
2e73a022	30	struct Channel {
5260325f	31	int type; /* channel type/state */
	32	int self; /* my own channel identifier */
	33	int remote_id; /* channel identifier for remote peer */
	34	/* peer can be reached over encrypted connection, via packet-sent */
	35	int istate; /* input from channel (state of receive half) */
	36	int ostate; /* output to channel (state of transmit half) */
7e7327a1	37	int flags; /* close sent/rcvd */
7368a6c8	38	int rfd; /* read fd */
	39	int wfd; /* write fd */
	40	int efd; /* extended fd */
	41	int sock; /* sock fd */
5260325f	42	Buffer input; /* data read from socket, to be sent over
	43	* encrypted connection */
	44	Buffer output; /* data received over encrypted connection for
	45	* send on socket */
7368a6c8	46	Buffer extended;
5260325f	47	char path[200]; /* path for unix domain sockets, or host name
	48	* for forwards */
	49	int listening_port; /* port being listened for forwards */
	50	int host_port; /* remote port to connect for forwards */
	51	char remote_name; / remote hostname */
7368a6c8	52
	53	int remote_window;
	54	int remote_maxpacket;
	55	int local_window;
	56	int local_window_max;
	57	int local_consumed;
	58	int local_maxpacket;
	59	int extended_usage;
	60
	61	char ctype; / type */
	62
1d1ffb87	63	/* callback */
7368a6c8	64	channel_callback_fn *cb_fn;
	65	void *cb_arg;
	66	int cb_event;
	67	channel_callback_fn *dettach_user;
2e73a022	68
	69	/* filter */
	70	channel_filter_fn *input_filter;
	71	};
7368a6c8	72
	73	#define CHAN_EXTENDED_IGNORE 0
	74	#define CHAN_EXTENDED_READ 1
	75	#define CHAN_EXTENDED_WRITE 2
	76
7e7327a1	77	void channel_set_fds(int id, int rfd, int wfd, int efd, int extusage);
7368a6c8	78	void channel_open(int id);
7e7327a1	79	void channel_request(int id, char *service, int wantconfirm);
	80	void channel_request_start(int id, char *service, int wantconfirm);
	81	void channel_register_callback(int id, int mtype, channel_callback_fn fn, void arg);
	82	void channel_register_cleanup(int id, channel_callback_fn *fn);
2e73a022	83	void channel_register_filter(int id, channel_filter_fn *fn);
7e7327a1	84	void channel_cancel_cleanup(int id);
7368a6c8	85	Channel *channel_lookup(int id);
	86
	87	int
	88	channel_new(char *ctype, int type, int rfd, int wfd, int efd,
	89	int window, int maxpack, int extended_usage, char *remote_name);
	90
7e7327a1	91	void channel_input_channel_request(int type, int plen);
7368a6c8	92	void channel_input_close(int type, int plen);
	93	void channel_input_close_confirmation(int type, int plen);
	94	void channel_input_data(int type, int plen);
7e7327a1	95	void channel_input_extended_data(int type, int plen);
7368a6c8	96	void channel_input_ieof(int type, int plen);
	97	void channel_input_oclose(int type, int plen);
	98	void channel_input_open_confirmation(int type, int plen);
	99	void channel_input_open_failure(int type, int plen);
	100	void channel_input_port_open(int type, int plen);
7e7327a1	101	void channel_input_window_adjust(int type, int plen);
7368a6c8	102	void channel_input_open(int type, int plen);
	103
	104	/* Sets specific protocol options. */
	105	void channel_set_options(int hostname_in_open);
	106
	107	/*
	108	* Allocate a new channel object and set its type and socket. Remote_name
	109	* must have been allocated with xmalloc; this will free it when the channel
	110	* is freed.
	111	*/
	112	int channel_allocate(int type, int sock, char *remote_name);
	113
	114	/* Free the channel and close its socket. */
	115	void channel_free(int channel);
	116
	117	/* Add any bits relevant to channels in select bitmasks. */
	118	void channel_prepare_select(fd_set * readset, fd_set * writeset);
	119
	120	/*
	121	* After select, perform any appropriate operations for channels which have
	122	* events pending.
	123	*/
	124	void channel_after_select(fd_set * readset, fd_set * writeset);
	125
	126	/* If there is data to send to the connection, send some of it now. */
	127	void channel_output_poll(void);
	128
	129	/* Returns true if no channel has too much buffered data. */
	130	int channel_not_very_much_buffered_data(void);
	131
	132	/* This closes any sockets that are listening for connections; this removes
	133	any unix domain sockets. */
	134	void channel_stop_listening(void);
	135
	136	/*
	137	* Closes the sockets of all channels. This is used to close extra file
	138	* descriptors after a fork.
	139	*/
	140	void channel_close_all(void);
	141
	142	/* Returns the maximum file descriptor number used by the channels. */
	143	int channel_max_fd(void);
	144
	145	/* Returns true if there is still an open channel over the connection. */
	146	int channel_still_open(void);
	147
	148	/*
	149	* Returns a string containing a list of all open channels. The list is
	150	* suitable for displaying to the user. It uses crlf instead of newlines.
	151	* The caller should free the string with xfree.
	152	*/
	153	char *channel_open_message(void);
	154
	155	/*
	156	* Initiate forwarding of connections to local port "port" through the secure
	157	* channel to host:port from remote side. This never returns if there was an
	158	* error.
	159	*/
6ae2364d	160	void
7368a6c8	161	channel_request_local_forwarding(u_short port, const char *host,
	162	u_short remote_port, int gateway_ports);
	163
	164	/*
	165	* Initiate forwarding of connections to port "port" on remote host through
	166	* the secure channel to host:port from local side. This never returns if
	167	* there was an error. This registers that open requests for that port are
	168	* permitted.
	169	*/
6ae2364d	170	void
7368a6c8	171	channel_request_remote_forwarding(u_short port, const char *host,
	172	u_short remote_port);
	173
	174	/*
	175	* Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually
	176	* called by the server, because the user could connect to any port anyway,
	177	* and the server has no way to know but to trust the client anyway.
	178	*/
	179	void channel_permit_all_opens(void);
	180
	181	/*
	182	* This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
	183	* listening for the port, and sends back a success reply (or disconnect
	184	* message if there was an error). This never returns if there was an error.
	185	*/
1d1ffb87	186	void channel_input_port_forward_request(int is_root, int gateway_ports);
7368a6c8	187
	188	/*
	189	* Creates a port for X11 connections, and starts listening for it. Returns
	190	* the display name, or NULL if an error was encountered.
	191	*/
	192	char *x11_create_display(int screen);
	193
	194	/*
	195	* Creates an internet domain socket for listening for X11 connections.
	196	* Returns a suitable value for the DISPLAY variable, or NULL if an error
	197	* occurs.
	198	*/
	199	char *x11_create_display_inet(int screen, int x11_display_offset);
	200
	201	/*
	202	* This is called when SSH_SMSG_X11_OPEN is received. The packet contains
	203	* the remote channel number. We should do whatever we want, and respond
	204	* with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
	205	*/
	206	void x11_input_open(int type, int plen);
	207
	208	/*
	209	* Requests forwarding of X11 connections. This should be called on the
	210	* client only.
	211	*/
	212	void x11_request_forwarding(void);
	213
	214	/*
	215	* Requests forwarding for X11 connections, with authentication spoofing.
	216	* This should be called in the client only.
	217	*/
0b242b12	218	void
	219	x11_request_forwarding_with_spoofing(int client_session_id,
	220	const char proto, const char data);
7368a6c8	221
	222	/* Sends a message to the server to request authentication fd forwarding. */
	223	void auth_request_forwarding(void);
	224
	225	/*
	226	* Returns the name of the forwarded authentication socket. Returns NULL if
	227	* there is no forwarded authentication socket. The returned value points to
	228	* a static buffer.
	229	*/
	230	char *auth_get_socket_name(void);
	231
	232	/*
fa649821	233	* This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.
7368a6c8	234	* This starts forwarding authentication requests.
7368a6c8	235	*/
fa649821	236	int auth_input_request_forwarding(struct passwd * pw);
7368a6c8	237
	238	/* This is called to process an SSH_SMSG_AGENT_OPEN message. */
	239	void auth_input_open_request(int type, int plen);
	240
7e7327a1	241	/* XXX */
7e7327a1	242	int channel_connect_to(const char *host, u_short host_port);
0b242b12	243	int x11_connect_display(void);
7e7327a1	244
8efc0c15	245	#endif