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
|
/*
* 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. */
#ifndef _CHANNEL_H_
#define _CHANNEL_H_
#include "includes.h"
#include "buffer.h"
#include "circbuffer.h"
/* channel->type values */
#define CHANNEL_ID_NONE 0
#define CHANNEL_ID_SESSION 1
#define CHANNEL_ID_X11 2
#define CHANNEL_ID_AGENT 3
#define CHANNEL_ID_TCPDIRECT 4
#define CHANNEL_ID_TCPFORWARDED 5
#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
/* Not a real type */
#define SSH_OPEN_IN_PROGRESS 99
#define MAX_CHANNELS 100 /* simple mem restriction, includes each tcp/x11
connection, so can't be _too_ small */
#define CHAN_EXTEND_SIZE 3 /* how many extra slots to add when we need more */
#define RECV_MAXWINDOW 8000 /* tweak */
#define RECV_WINDOWEXTEND 1000 /* We send a "window extend" every
RECV_WINDOWEXTEND bytes */
#define RECV_MAXPACKET RECV_MAXWINDOW /* tweak */
struct ChanType;
struct Channel {
unsigned int index; /* the local channel index */
unsigned int remotechan;
unsigned int recvwindow, transwindow;
unsigned int recvdonelen;
unsigned int recvmaxpacket, transmaxpacket;
void* typedata; /* a pointer to type specific data */
int writefd; /* read from wire, written to insecure side */
int readfd; /* read from insecure size, written to wire */
int errfd; /* used like writefd or readfd, depending if it's client or server.
Doesn't exactly belong here, but is cleaner here */
circbuffer *writebuf; /* data from the wire, for local consumption */
circbuffer *extrabuf; /* extended-data for the program - used like writebuf
but for stderr */
int sentclosed, recvclosed;
/* this is set when we receive/send a channel eof packet */
int recveof, senteof;
int initconn; /* used for TCP forwarding, whether the channel has been
fully initialised */
int await_open; /* flag indicating whether we've sent an open request
for this channel (and are awaiting a confirmation
or failure). */
const struct ChanType* type;
};
struct ChanType {
int sepfds; /* Whether this channel has seperate pipes for in/out or not */
char *name;
int (*inithandler)(struct Channel*);
int (*checkclose)(struct Channel*);
void (*reqhandler)(struct Channel*);
void (*closehandler)(struct Channel*);
};
void chaninitialise(const struct ChanType *chantypes[]);
void chancleanup();
void setchannelfds(fd_set *readfd, fd_set *writefd);
void channelio(fd_set *readfd, fd_set *writefd);
struct Channel* getchannel();
struct Channel* newchannel(unsigned int remotechan,
const struct ChanType *type,
unsigned int transwindow, unsigned int transmaxpacket);
void recv_msg_channel_open();
void recv_msg_channel_request();
void send_msg_channel_failure(struct Channel *channel);
void send_msg_channel_success(struct Channel *channel);
void recv_msg_channel_data();
void recv_msg_channel_extended_data();
void recv_msg_channel_window_adjust();
void recv_msg_channel_close();
void recv_msg_channel_eof();
void common_recv_msg_channel_data(struct Channel *channel, int fd,
circbuffer * buf);
#ifdef DROPBEAR_CLIENT
extern const struct ChanType clichansess;
#endif
#if defined(USING_LISTENERS) || defined(DROPBEAR_CLIENT)
int send_msg_channel_open_init(int fd, const struct ChanType *type);
void recv_msg_channel_open_confirmation();
void recv_msg_channel_open_failure();
#endif
#endif /* _CHANNEL_H_ */
|
