1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
|
/* $OpenBSD: channels.h,v 1.66 2002/03/25 21:13:51 markus Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
/*
* Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef CHANNEL_H
#define CHANNEL_H
#include "buffer.h"
/* Definitions for channel types. */
#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_RPORT_LISTENER 11 /* Listening to a R-style port */
#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_PATH_LEN 256
struct Channel;
typedef struct Channel Channel;
typedef void channel_callback_fn(int, void *);
typedef int channel_filter_fn(struct Channel *, char *, int);
struct Channel {
int type; /* channel type/state */
int self; /* my own channel identifier */
int remote_id; /* channel identifier for remote peer */
u_int istate; /* input from channel (state of receive half) */
u_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 */
int isatty; /* rfd is a tty */
int force_drain; /* force close on iEOF */
int delayed; /* fdset hack */
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[SSH_CHANNEL_PATH_LEN];
/* 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;
int single_connection;
char *ctype; /* type */
/* callback */
channel_callback_fn *confirm;
channel_callback_fn *detach_user;
/* filter */
channel_filter_fn *input_filter;
};
#define CHAN_EXTENDED_IGNORE 0
#define CHAN_EXTENDED_READ 1
#define CHAN_EXTENDED_WRITE 2
/* default window/packet sizes for tcp/x11-fwd-channel */
#define CHAN_SES_PACKET_DEFAULT (32*1024)
#define CHAN_SES_WINDOW_DEFAULT (4*CHAN_SES_PACKET_DEFAULT)
#define CHAN_TCP_PACKET_DEFAULT (32*1024)
#define CHAN_TCP_WINDOW_DEFAULT (4*CHAN_TCP_PACKET_DEFAULT)
#define CHAN_X11_PACKET_DEFAULT (16*1024)
#define CHAN_X11_WINDOW_DEFAULT (4*CHAN_X11_PACKET_DEFAULT)
/* possible input states */
#define CHAN_INPUT_OPEN 0
#define CHAN_INPUT_WAIT_DRAIN 1
#define CHAN_INPUT_WAIT_OCLOSE 2
#define CHAN_INPUT_CLOSED 3
/* possible output states */
#define CHAN_OUTPUT_OPEN 0
#define CHAN_OUTPUT_WAIT_DRAIN 1
#define CHAN_OUTPUT_WAIT_IEOF 2
#define CHAN_OUTPUT_CLOSED 3
#define CHAN_CLOSE_SENT 0x01
#define CHAN_CLOSE_RCVD 0x02
#define CHAN_EOF_SENT 0x04
#define CHAN_EOF_RCVD 0x08
/* check whether 'efd' is still in use */
#define CHANNEL_EFD_INPUT_ACTIVE(c) \
(compat20 && c->extended_usage == CHAN_EXTENDED_READ && \
(c->efd != -1 || \
buffer_len(&c->extended) > 0))
#define CHANNEL_EFD_OUTPUT_ACTIVE(c) \
(compat20 && c->extended_usage == CHAN_EXTENDED_WRITE && \
((c->efd != -1 && !(c->flags & CHAN_EOF_RCVD)) || \
buffer_len(&c->extended) > 0))
/* channel management */
Channel *channel_lookup(int);
Channel *channel_new(char *, int, int, int, int, int, int, int, char *, int);
void channel_set_fds(int, int, int, int, int, int, u_int);
void channel_free(Channel *);
void channel_free_all(void);
void channel_stop_listening(void);
void channel_send_open(int);
void channel_request_start(int, char *, int);
void channel_register_cleanup(int, channel_callback_fn *);
void channel_register_confirm(int, channel_callback_fn *);
void channel_register_filter(int, channel_filter_fn *);
void channel_cancel_cleanup(int);
int channel_close_fd(int *);
/* protocol handler */
void channel_input_close(int, u_int32_t, void *);
void channel_input_close_confirmation(int, u_int32_t, void *);
void channel_input_data(int, u_int32_t, void *);
void channel_input_extended_data(int, u_int32_t, void *);
void channel_input_ieof(int, u_int32_t, void *);
void channel_input_oclose(int, u_int32_t, void *);
void channel_input_open_confirmation(int, u_int32_t, void *);
void channel_input_open_failure(int, u_int32_t, void *);
void channel_input_port_open(int, u_int32_t, void *);
void channel_input_window_adjust(int, u_int32_t, void *);
/* file descriptor handling (read/write) */
void channel_prepare_select(fd_set **, fd_set **, int *, int*, int);
void channel_after_select(fd_set *, fd_set *);
void channel_output_poll(void);
int channel_not_very_much_buffered_data(void);
void channel_close_all(void);
int channel_still_open(void);
char *channel_open_message(void);
int channel_find_open(void);
/* tcp forwarding */
void channel_set_af(int af);
void channel_permit_all_opens(void);
void channel_add_permitted_opens(char *, int);
void channel_clear_permitted_opens(void);
void channel_input_port_forward_request(int, int);
int channel_connect_to(const char *, u_short);
int channel_connect_by_listen_address(u_short);
void channel_request_remote_forwarding(u_short, const char *, u_short);
int channel_setup_local_fwd_listener(u_short, const char *, u_short, int);
int channel_setup_remote_fwd_listener(const char *, u_short, int);
/* x11 forwarding */
int x11_connect_display(void);
int x11_create_display_inet(int, int, int);
void x11_input_open(int, u_int32_t, void *);
void x11_request_forwarding_with_spoofing(int, const char *, const char *);
void deny_input_open(int, u_int32_t, void *);
/* agent forwarding */
void auth_request_forwarding(void);
char *auth_get_socket_name(void);
void auth_sock_cleanup_proc(void *);
int auth_input_request_forwarding(struct passwd *);
void auth_input_open_request(int, u_int32_t, void *);
/* channel close */
int chan_is_dead(Channel *, int);
void chan_mark_dead(Channel *);
/* channel events */
void chan_rcvd_oclose(Channel *);
void chan_read_failed(Channel *);
void chan_ibuf_empty(Channel *);
void chan_rcvd_ieof(Channel *);
void chan_write_failed(Channel *);
void chan_obuf_empty(Channel *);
#endif
|
