xref: /titanic_41/usr/src/cmd/ssh/include/channels.h (revision e5ba14ff435beeefdaa2e6649e175c74afe02c76)
1 /*
2  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 /*	$OpenBSD: channels.h,v 1.70 2002/06/24 14:33:27 markus Exp $	*/
6 
7 #ifndef	_CHANNELS_H
8 #define	_CHANNELS_H
9 
10 #pragma ident	"%Z%%M%	%I%	%E% SMI"
11 
12 #ifdef __cplusplus
13 extern "C" {
14 #endif
15 
16 
17 /*
18  * Author: Tatu Ylonen <ylo@cs.hut.fi>
19  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
20  *                    All rights reserved
21  *
22  * As far as I am concerned, the code I have written for this software
23  * can be used freely for any purpose.  Any derived versions of this
24  * software must be clearly marked as such, and if the derived work is
25  * incompatible with the protocol description in the RFC file, it must be
26  * called by a name other than "ssh" or "Secure Shell".
27  */
28 /*
29  * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl.  All rights reserved.
30  *
31  * Redistribution and use in source and binary forms, with or without
32  * modification, are permitted provided that the following conditions
33  * are met:
34  * 1. Redistributions of source code must retain the above copyright
35  *    notice, this list of conditions and the following disclaimer.
36  * 2. Redistributions in binary form must reproduce the above copyright
37  *    notice, this list of conditions and the following disclaimer in the
38  *    documentation and/or other materials provided with the distribution.
39  *
40  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
41  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
42  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
43  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
44  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
46  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
47  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
48  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
49  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
50  */
51 
52 #include "buffer.h"
53 
54 /* Definitions for channel types. */
55 #define SSH_CHANNEL_X11_LISTENER	1	/* Listening for inet X11 conn. */
56 #define SSH_CHANNEL_PORT_LISTENER	2	/* Listening on a port. */
57 #define SSH_CHANNEL_OPENING		3	/* waiting for confirmation */
58 #define SSH_CHANNEL_OPEN		4	/* normal open two-way channel */
59 #define SSH_CHANNEL_CLOSED		5	/* waiting for close confirmation */
60 #define SSH_CHANNEL_AUTH_SOCKET		6	/* authentication socket */
61 #define SSH_CHANNEL_X11_OPEN		7	/* reading first X11 packet */
62 #define SSH_CHANNEL_INPUT_DRAINING	8	/* sending remaining data to conn */
63 #define SSH_CHANNEL_OUTPUT_DRAINING	9	/* sending remaining data to app */
64 #define SSH_CHANNEL_LARVAL		10	/* larval session */
65 #define SSH_CHANNEL_RPORT_LISTENER	11	/* Listening to a R-style port  */
66 #define SSH_CHANNEL_CONNECTING		12
67 #define SSH_CHANNEL_DYNAMIC		13
68 #define SSH_CHANNEL_ZOMBIE		14	/* Almost dead. */
69 #define SSH_CHANNEL_MAX_TYPE		15
70 
71 #define SSH_CHANNEL_PATH_LEN		256
72 
73 struct Channel;
74 typedef struct Channel Channel;
75 
76 typedef void channel_callback_fn(int, void *);
77 typedef int channel_filter_fn(struct Channel *, char *, int);
78 
79 struct Channel {
80 	int     type;		/* channel type/state */
81 	int     self;		/* my own channel identifier */
82 	int     remote_id;	/* channel identifier for remote peer */
83 	u_int   istate;		/* input from channel (state of receive half) */
84 	u_int   ostate;		/* output to channel  (state of transmit half) */
85 	int	wait_for_exit;	/* no close till after exit-status is sent */
86 	int     flags;		/* close sent/rcvd */
87 	int     rfd;		/* read fd */
88 	int     wfd;		/* write fd */
89 	int     efd;		/* extended fd */
90 	int     sock;		/* sock fd */
91 	int     isatty;		/* rfd is a tty */
92 	int     wfd_isatty;	/* wfd is a tty */
93 	int     force_drain;	/* force close on iEOF */
94 	int     delayed;		/* fdset hack */
95 	Buffer  input;		/* data read from socket, to be sent over
96 				 * encrypted connection */
97 	Buffer  output;		/* data received over encrypted connection for
98 				 * send on socket */
99 	Buffer  extended;
100 	char    path[SSH_CHANNEL_PATH_LEN];
101 		/* path for unix domain sockets, or host name for forwards */
102 	int     listening_port;	/* port being listened for forwards */
103 	int     host_port;	/* remote port to connect for forwards */
104 	char   *remote_name;	/* remote hostname */
105 
106 	u_int	remote_window;
107 	u_int	remote_maxpacket;
108 	u_int	local_window;
109 	u_int	local_window_max;
110 	u_int	local_consumed;
111 	u_int	local_maxpacket;
112 	int     extended_usage;
113 	int	single_connection;
114 
115 	char   *ctype;		/* type */
116 
117 	/* callback */
118 	channel_callback_fn	*confirm;
119 	channel_callback_fn	*detach_user;
120 
121 	/* filter */
122 	channel_filter_fn	*input_filter;
123 };
124 
125 #define CHAN_EXTENDED_IGNORE		0
126 #define CHAN_EXTENDED_READ		1
127 #define CHAN_EXTENDED_WRITE		2
128 
129 /* default window/packet sizes for tcp/x11-fwd-channel */
130 #define CHAN_SES_PACKET_DEFAULT	(32*1024)
131 #define CHAN_SES_WINDOW_DEFAULT	(4*CHAN_SES_PACKET_DEFAULT)
132 #define CHAN_TCP_PACKET_DEFAULT	(32*1024)
133 #define CHAN_TCP_WINDOW_DEFAULT	(4*CHAN_TCP_PACKET_DEFAULT)
134 #define CHAN_X11_PACKET_DEFAULT	(16*1024)
135 #define CHAN_X11_WINDOW_DEFAULT	(4*CHAN_X11_PACKET_DEFAULT)
136 
137 /* possible input states */
138 #define CHAN_INPUT_OPEN			0
139 #define CHAN_INPUT_WAIT_DRAIN		1
140 #define CHAN_INPUT_WAIT_OCLOSE		2
141 #define CHAN_INPUT_CLOSED		3
142 
143 /* possible output states */
144 #define CHAN_OUTPUT_OPEN		0
145 #define CHAN_OUTPUT_WAIT_DRAIN		1
146 #define CHAN_OUTPUT_WAIT_IEOF		2
147 #define CHAN_OUTPUT_CLOSED		3
148 
149 /*
150  * Other channel flag bits are specific to each type of channel and are
151  * defined locally with the code that uses them.
152  */
153 #define CHAN_CLOSE_SENT			0x01
154 #define CHAN_CLOSE_RCVD			0x02
155 #define CHAN_EOF_SENT			0x04
156 #define CHAN_EOF_RCVD			0x08
157 
158 /* check whether 'efd' is still in use */
159 #define CHANNEL_EFD_INPUT_ACTIVE(c) \
160 	(compat20 && c->extended_usage == CHAN_EXTENDED_READ && \
161 	(c->efd != -1 || \
162 	buffer_len(&c->extended) > 0))
163 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \
164 	(compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \
165 	((c->efd != -1 && !(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD))) || \
166 	buffer_len(&c->extended) > 0))
167 
168 /* channel management */
169 
170 Channel	*channel_lookup(int);
171 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int);
172 void	 channel_set_fds(int, int, int, int, int, int, u_int);
173 void	 channel_set_wait_for_exit(int, int);
174 void	 channel_free(Channel *);
175 void	 channel_free_all(void);
176 void	 channel_stop_listening(void);
177 
178 void	 channel_send_open(int);
179 void	 channel_request_start(int, char *, int);
180 void	 channel_register_cleanup(int, channel_callback_fn *);
181 void	 channel_register_confirm(int, channel_callback_fn *);
182 void	 channel_register_filter(int, channel_filter_fn *);
183 void	 channel_cancel_cleanup(int);
184 int	 channel_close_fd(int *);
185 
186 /* protocol handler */
187 
188 void	 channel_input_close(int, u_int32_t, void *);
189 void	 channel_input_close_confirmation(int, u_int32_t, void *);
190 void	 channel_input_data(int, u_int32_t, void *);
191 void	 channel_input_extended_data(int, u_int32_t, void *);
192 void	 channel_input_ieof(int, u_int32_t, void *);
193 void	 channel_input_oclose(int, u_int32_t, void *);
194 void	 channel_input_open_confirmation(int, u_int32_t, void *);
195 void	 channel_input_open_failure(int, u_int32_t, void *);
196 void	 channel_input_port_open(int, u_int32_t, void *);
197 void	 channel_input_window_adjust(int, u_int32_t, void *);
198 
199 /* file descriptor handling (read/write) */
200 
201 void	 channel_prepare_select(fd_set **, fd_set **, int *, int*, int);
202 void     channel_after_select(fd_set *, fd_set *);
203 void     channel_output_poll(void);
204 
205 int      channel_not_very_much_buffered_data(void);
206 void     channel_close_all(void);
207 int      channel_still_open(void);
208 char	*channel_open_message(void);
209 int	 channel_find_open(void);
210 
211 /* tcp forwarding */
212 void	 channel_set_af(int af);
213 void     channel_permit_all_opens(void);
214 void	 channel_add_permitted_opens(char *, int);
215 void	 channel_clear_permitted_opens(void);
216 void     channel_input_port_forward_request(int, int);
217 int	 channel_connect_to(const char *, u_short);
218 int	 channel_connect_by_listen_address(u_short);
219 void	 channel_request_remote_forwarding(u_short, const char *, u_short);
220 int	 channel_setup_local_fwd_listener(u_short, const char *, u_short, int);
221 int	 channel_setup_remote_fwd_listener(const char *, u_short, int);
222 
223 /* x11 forwarding */
224 
225 int	 x11_connect_display(void);
226 int	 x11_create_display_inet(int, int, int, u_int *);
227 void     x11_input_open(int, u_int32_t, void *);
228 void	 x11_request_forwarding_with_spoofing(int, const char *, const char *,
229 	     const char *);
230 void	 deny_input_open(int, u_int32_t, void *);
231 
232 /* agent forwarding */
233 
234 void	 auth_request_forwarding(void);
235 void	 auth_input_open_request(int, u_int32_t, void *);
236 
237 /* channel close */
238 
239 int	 chan_is_dead(Channel *, int);
240 void	 chan_mark_dead(Channel *);
241 
242 /* channel events */
243 
244 void	 chan_rcvd_oclose(Channel *);
245 void	 chan_read_failed(Channel *);
246 void	 chan_ibuf_empty(Channel *);
247 
248 void	 chan_rcvd_ieof(Channel *);
249 void	 chan_write_failed(Channel *);
250 void	 chan_obuf_empty(Channel *);
251 
252 #ifdef __cplusplus
253 }
254 #endif
255 
256 #endif /* _CHANNELS_H */
257