1 /*
2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
5 *
6 * As far as I am concerned, the code I have written for this software
7 * can be used freely for any purpose. Any derived versions of this
8 * software must be clearly marked as such, and if the derived work is
9 * incompatible with the protocol description in the RFC file, it must be
10 * called by a name other than "ssh" or "Secure Shell".
11 */
12 /*
13 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35 /*
36 * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
37 */
38 /* $OpenBSD: channels.h,v 1.70 2002/06/24 14:33:27 markus Exp $ */
39
40
41 #ifndef _CHANNELS_H
42 #define _CHANNELS_H
43
44 #ifdef __cplusplus
45 extern "C" {
46 #endif
47
48 #include "buffer.h"
49
50 /* Definitions for channel types. */
51 #define SSH_CHANNEL_X11_LISTENER 1 /* Listening for inet X11 conn. */
52 #define SSH_CHANNEL_PORT_LISTENER 2 /* Listening on a port. */
53 #define SSH_CHANNEL_OPENING 3 /* waiting for confirmation */
54 #define SSH_CHANNEL_OPEN 4 /* normal open two-way channel */
55 #define SSH_CHANNEL_CLOSED 5 /* waiting for close confirmation */
56 #define SSH_CHANNEL_AUTH_SOCKET 6 /* authentication socket */
57 #define SSH_CHANNEL_X11_OPEN 7 /* reading first X11 packet */
58 #define SSH_CHANNEL_INPUT_DRAINING 8 /* sending remaining data to conn */
59 #define SSH_CHANNEL_OUTPUT_DRAINING 9 /* sending remaining data to app */
60 #define SSH_CHANNEL_LARVAL 10 /* larval session */
61 #define SSH_CHANNEL_RPORT_LISTENER 11 /* Listening to a R-style port */
62 #define SSH_CHANNEL_CONNECTING 12
63 #define SSH_CHANNEL_DYNAMIC 13
64 #define SSH_CHANNEL_ZOMBIE 14 /* Almost dead. */
65 #define SSH_CHANNEL_MAX_TYPE 15
66
67 #define SSH_CHANNEL_PATH_LEN 256
68
69 struct Channel;
70 typedef struct Channel Channel;
71
72 typedef void channel_callback_fn(int, void *);
73 typedef int channel_filter_fn(struct Channel *, char *, int);
74
75 struct Channel {
76 int type; /* channel type/state */
77 int self; /* my own channel identifier */
78 int remote_id; /* channel identifier for remote peer */
79 u_int istate; /* input from channel (state of receive half) */
80 u_int ostate; /* output to channel (state of transmit half) */
81 int wait_for_exit; /* no close till after exit-status is sent */
82 int flags; /* close sent/rcvd */
83 int rfd; /* read fd */
84 int wfd; /* write fd */
85 int efd; /* extended fd */
86 int sock; /* sock fd */
87 int isatty; /* rfd is a tty */
88 int wfd_isatty; /* wfd is a tty */
89 int force_drain; /* force close on iEOF */
90 int delayed; /* post-select handlers for newly created
91 * channels are delayed until the first call
92 * to a matching pre-select handler.
93 * this way post-select handlers are not
94 * accidenly called if a FD gets reused */
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 #define CHAN_RBUF 16*1024
159
160 /* check whether 'efd' is still in use */
161 #define CHANNEL_EFD_INPUT_ACTIVE(c) \
162 (compat20 && c->extended_usage == CHAN_EXTENDED_READ && \
163 (c->efd != -1 || \
164 buffer_len(&c->extended) > 0))
165 #define CHANNEL_EFD_OUTPUT_ACTIVE(c) \
166 (compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \
167 ((c->efd != -1 && !(c->flags & (CHAN_EOF_RCVD|CHAN_CLOSE_RCVD))) || \
168 buffer_len(&c->extended) > 0))
169
170 /* channel management */
171
172 Channel *channel_lookup(int);
173 Channel *channel_new(char *, int, int, int, int, u_int, u_int, int, char *, int);
174 void channel_set_fds(int, int, int, int, int, int, u_int);
175 void channel_set_wait_for_exit(int, int);
176 void channel_free(Channel *);
177 void channel_free_all(void);
178 void channel_stop_listening(void);
179
180 void channel_send_open(int);
181 void channel_request_start(int, char *, int);
182 void channel_register_cleanup(int, channel_callback_fn *);
183 void channel_register_confirm(int, channel_callback_fn *);
184 void channel_register_filter(int, channel_filter_fn *);
185 void channel_cancel_cleanup(int);
186 int channel_close_fd(int *);
187
188 /* protocol handler */
189
190 void channel_input_close(int, u_int32_t, void *);
191 void channel_input_close_confirmation(int, u_int32_t, void *);
192 void channel_input_data(int, u_int32_t, void *);
193 void channel_input_extended_data(int, u_int32_t, void *);
194 void channel_input_ieof(int, u_int32_t, void *);
195 void channel_input_oclose(int, u_int32_t, void *);
196 void channel_input_open_confirmation(int, u_int32_t, void *);
197 void channel_input_open_failure(int, u_int32_t, void *);
198 void channel_input_port_open(int, u_int32_t, void *);
199 void channel_input_window_adjust(int, u_int32_t, void *);
200
201 /* file descriptor handling (read/write) */
202
203 void channel_prepare_select(fd_set **, fd_set **, int *, int*, int);
204 void channel_after_select(fd_set *, fd_set *);
205 void channel_output_poll(void);
206
207 int channel_not_very_much_buffered_data(void);
208 void channel_close_all(void);
209 int channel_still_open(void);
210 char *channel_open_message(void);
211 int channel_find_open(void);
212
213 /* tcp forwarding */
214 void channel_set_af(int af);
215 void channel_permit_all_opens(void);
216 void channel_add_permitted_opens(char *, int);
217 void channel_clear_permitted_opens(void);
218 void channel_input_port_forward_request(int, int);
219 int channel_connect_to(const char *, u_short);
220 int channel_connect_by_listen_address(u_short);
221 int channel_request_remote_forwarding(const char *, u_short,
222 const char *, u_short);
223 int channel_setup_local_fwd_listener(const char *, u_short,
224 const char *, u_short, int);
225 void channel_request_rforward_cancel(const char *host, u_short port);
226 int channel_setup_remote_fwd_listener(const char *, u_short, int);
227 int channel_cancel_rport_listener(const char *, u_short);
228
229 /* x11 forwarding */
230
231 int x11_connect_display(void);
232 int x11_create_display_inet(int, int, int, u_int *);
233 void x11_input_open(int, u_int32_t, void *);
234 void x11_request_forwarding_with_spoofing(int, const char *, const char *,
235 const char *);
236 void deny_input_open(int, u_int32_t, void *);
237
238 /* agent forwarding */
239
240 void auth_request_forwarding(void);
241 void auth_input_open_request(int, u_int32_t, void *);
242
243 /* channel close */
244
245 int chan_is_dead(Channel *, int);
246 void chan_mark_dead(Channel *);
247
248 /* channel events */
249
250 void chan_rcvd_oclose(Channel *);
251 void chan_rcvd_eow(Channel *); /* SSH2-only */
252 void chan_read_failed(Channel *);
253 void chan_ibuf_empty(Channel *);
254
255 void chan_rcvd_ieof(Channel *);
256 void chan_write_failed(Channel *);
257 void chan_obuf_empty(Channel *);
258
259 #ifdef __cplusplus
260 }
261 #endif
262
263 #endif /* _CHANNELS_H */