channel.h 5.1 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
/*
 * Dropbear - a SSH2 server
 * 
 * Copyright (c) 2002,2003 Matt Johnston
 * All rights reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE. */

25
26
#ifndef DROPBEAR_CHANNEL_H_
#define DROPBEAR_CHANNEL_H_
27
28
29

#include "includes.h"
#include "buffer.h"
Matt Johnston's avatar
Nasty.    
Matt Johnston committed
30
#include "circbuffer.h"
31
32
33
34
35
36

#define SSH_OPEN_ADMINISTRATIVELY_PROHIBITED    1
#define SSH_OPEN_CONNECT_FAILED                 2
#define SSH_OPEN_UNKNOWN_CHANNEL_TYPE           3
#define SSH_OPEN_RESOURCE_SHORTAGE              4

37
38
39
/* Not a real type */
#define SSH_OPEN_IN_PROGRESS					99

40
41
42
43
#define CHAN_EXTEND_SIZE 3 /* how many extra slots to add when we need more */

struct ChanType;

Matt Johnston's avatar
Matt Johnston committed
44
45
46
47
48
49
50
enum dropbear_channel_prio {
	DROPBEAR_CHANNEL_PRIO_INTERACTIVE, /* pty shell, x11 */
	DROPBEAR_CHANNEL_PRIO_UNKNOWABLE, /* tcp - can't know what's being forwarded */
	DROPBEAR_CHANNEL_PRIO_BULK, /* the rest - probably scp or something */
	DROPBEAR_CHANNEL_PRIO_EARLY, /* channel is still being set up */
};

51
52
53
54
55
struct Channel {

	unsigned int index; /* the local channel index */
	unsigned int remotechan;
	unsigned int recvwindow, transwindow;
56
	unsigned int recvdonelen;
57
58
	unsigned int recvmaxpacket, transmaxpacket;
	void* typedata; /* a pointer to type specific data */
59
	int writefd; /* read from wire, written to insecure side */
60
	int readfd; /* read from insecure side, written to wire */
61
	int errfd; /* used like writefd or readfd, depending if it's client or server.
Matt Johnston's avatar
Nasty.    
Matt Johnston committed
62
				  Doesn't exactly belong here, but is cleaner here */
63
64
	circbuffer *writebuf; /* data from the wire, for local consumption. Can be
							 initially NULL */
Matt Johnston's avatar
Nasty.    
Matt Johnston committed
65
66
	circbuffer *extrabuf; /* extended-data for the program - used like writebuf
					     but for stderr */
67

68
69
70
	/* whether close/eof messages have been exchanged */
	int sent_close, recv_close;
	int recv_eof, sent_eof;
71

72
73
74
75
	/* Set after running the ChanType-specific close hander
	 * to ensure we don't run it twice (nor type->checkclose()). */
	int close_handler_done;

Matt Johnston's avatar
Matt Johnston committed
76
	struct dropbear_progress_connection *conn_pending;
77
78
79
	int initconn; /* used for TCP forwarding, whether the channel has been
					 fully initialised */

80
81
82
83
	int await_open; /* flag indicating whether we've sent an open request
					   for this channel (and are awaiting a confirmation
					   or failure). */

84
85
	int flushing;

86
87
	/* Used by client chansession to handle ~ escaping, NULL ignored otherwise */
	void (*read_mangler)(struct Channel*, unsigned char* bytes, int *len);
88

89
	const struct ChanType* type;
Matt Johnston's avatar
Matt Johnston committed
90
91

	enum dropbear_channel_prio prio;
92
93
94
95
};

struct ChanType {

96
	int sepfds; /* Whether this channel has separate pipes for in/out or not */
97
98
	char *name;
	int (*inithandler)(struct Channel*);
99
	int (*check_close)(struct Channel*);
100
101
102
103
	void (*reqhandler)(struct Channel*);
	void (*closehandler)(struct Channel*);
};

Matt Johnston's avatar
Matt Johnston committed
104
105
106
/* Callback for connect_remote */
void channel_connect_done(int result, int sock, void* user_data, const char* errstring);

107
void chaninitialise(const struct ChanType *chantypes[]);
Francois Perrad's avatar
Francois Perrad committed
108
void chancleanup(void);
109
void setchannelfds(fd_set *readfds, fd_set *writefds, int allow_reads);
110
void channelio(fd_set *readfd, fd_set *writefd);
Francois Perrad's avatar
Francois Perrad committed
111
struct Channel* getchannel(void);
112
113
/* Returns an arbitrary channel that is in a ready state - not
being initialised and no EOF in either direction. NULL if none. */
Francois Perrad's avatar
Francois Perrad committed
114
struct Channel* get_any_ready_channel(void);
115

Francois Perrad's avatar
Francois Perrad committed
116
117
void recv_msg_channel_open(void);
void recv_msg_channel_request(void);
118
119
void send_msg_channel_failure(struct Channel *channel);
void send_msg_channel_success(struct Channel *channel);
Francois Perrad's avatar
Francois Perrad committed
120
121
122
123
124
void recv_msg_channel_data(void);
void recv_msg_channel_extended_data(void);
void recv_msg_channel_window_adjust(void);
void recv_msg_channel_close(void);
void recv_msg_channel_eof(void);
125

Matt Johnston's avatar
Nasty.    
Matt Johnston committed
126
127
128
void common_recv_msg_channel_data(struct Channel *channel, int fd, 
		circbuffer * buf);

129
#if DROPBEAR_CLIENT
130
extern const struct ChanType clichansess;
131
#endif
Matt Johnston's avatar
Nasty.    
Matt Johnston committed
132

133
#if DROPBEAR_LISTENERS || DROPBEAR_CLIENT
134
int send_msg_channel_open_init(int fd, const struct ChanType *type);
Francois Perrad's avatar
Francois Perrad committed
135
136
void recv_msg_channel_open_confirmation(void);
void recv_msg_channel_open_failure(void);
137
#endif
138
void start_send_channel_request(struct Channel *channel, char *type);
139

Francois Perrad's avatar
Francois Perrad committed
140
141
void send_msg_request_success(void);
void send_msg_request_failure(void);
142

143

144
#endif /* DROPBEAR_CHANNEL_H_ */