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
|
#include "includes.h"
RCSID("$Id: nchan.c,v 1.1 1999/10/27 03:42:44 damien Exp $");
#include "ssh.h"
#include "buffer.h"
#include "packet.h"
#include "channels.h"
#include "nchan.h"
static void chan_send_ieof(Channel *c);
static void chan_send_oclose(Channel *c);
static void chan_shutdown_write(Channel *c);
static void chan_shutdown_read(Channel *c);
static void chan_delele_if_full_closed(Channel *c);
/*
* EVENTS: update channel input/output states
* execute ACTIONS
*/
/* events concerning the INPUT from socket for channel (istate) */
void
chan_rcvd_oclose(Channel *c){
switch(c->istate){
case CHAN_INPUT_WAIT_OCLOSE:
debug("channel %d: INPUT_WAIT_OCLOSE -> INPUT_CLOSED [rcvd OCLOSE]", c->self);
c->istate=CHAN_INPUT_CLOSED;
chan_delele_if_full_closed(c);
break;
case CHAN_INPUT_OPEN:
debug("channel %d: INPUT_OPEN -> INPUT_CLOSED [rvcd OCLOSE, send IEOF]", c->self);
chan_shutdown_read(c);
chan_send_ieof(c);
c->istate=CHAN_INPUT_CLOSED;
chan_delele_if_full_closed(c);
break;
default:
debug("protocol error: chan_rcvd_oclose %d for istate %d",c->self,c->istate);
break;
}
}
void
chan_read_failed(Channel *c){
switch(c->istate){
case CHAN_INPUT_OPEN:
debug("channel %d: INPUT_OPEN -> INPUT_WAIT_DRAIN [read failed]", c->self);
chan_shutdown_read(c);
c->istate=CHAN_INPUT_WAIT_DRAIN;
break;
default:
debug("internal error: we do not read, but chan_read_failed %d for istate %d",
c->self,c->istate);
break;
}
}
void
chan_ibuf_empty(Channel *c){
if(buffer_len(&c->input)){
debug("internal error: chan_ibuf_empty %d for non empty buffer",c->self);
return;
}
switch(c->istate){
case CHAN_INPUT_WAIT_DRAIN:
debug("channel %d: INPUT_WAIT_DRAIN -> INPUT_WAIT_OCLOSE [inbuf empty, send IEOF]", c->self);
chan_send_ieof(c);
c->istate=CHAN_INPUT_WAIT_OCLOSE;
break;
default:
debug("internal error: chan_ibuf_empty %d for istate %d",c->self,c->istate);
break;
}
}
/* events concerning the OUTPUT from channel for socket (ostate) */
void
chan_rcvd_ieof(Channel *c){
switch(c->ostate){
case CHAN_OUTPUT_OPEN:
debug("channel %d: OUTPUT_OPEN -> OUTPUT_WAIT_DRAIN [rvcd IEOF]", c->self);
c->ostate=CHAN_OUTPUT_WAIT_DRAIN;
break;
case CHAN_OUTPUT_WAIT_IEOF:
debug("channel %d: OUTPUT_WAIT_IEOF -> OUTPUT_CLOSED [rvcd IEOF]", c->self);
c->ostate=CHAN_OUTPUT_CLOSED;
chan_delele_if_full_closed(c);
break;
default:
debug("protocol error: chan_rcvd_ieof %d for ostate %d", c->self,c->ostate);
break;
}
}
void
chan_write_failed(Channel *c){
switch(c->ostate){
case CHAN_OUTPUT_OPEN:
debug("channel %d: OUTPUT_OPEN -> OUTPUT_WAIT_IEOF [write failed]", c->self);
chan_send_oclose(c);
c->ostate=CHAN_OUTPUT_WAIT_IEOF;
break;
case CHAN_OUTPUT_WAIT_DRAIN:
debug("channel %d: OUTPUT_WAIT_DRAIN -> OUTPUT_CLOSED [write failed]", c->self);
chan_send_oclose(c);
c->ostate=CHAN_OUTPUT_CLOSED;
chan_delele_if_full_closed(c);
break;
default:
debug("internal error: chan_write_failed %d for ostate %d",c->self,c->ostate);
break;
}
}
void
chan_obuf_empty(Channel *c){
if(buffer_len(&c->output)){
debug("internal error: chan_obuf_empty %d for non empty buffer",c->self);
return;
}
switch(c->ostate){
case CHAN_OUTPUT_WAIT_DRAIN:
debug("channel %d: OUTPUT_WAIT_DRAIN -> OUTPUT_CLOSED [obuf empty, send OCLOSE]", c->self);
chan_send_oclose(c);
c->ostate=CHAN_OUTPUT_CLOSED;
chan_delele_if_full_closed(c);
break;
default:
debug("internal error: chan_obuf_empty %d for ostate %d",c->self,c->ostate);
break;
}
}
/*
* ACTIONS: should never update c->istate or c->ostate
*/
static void
chan_send_ieof(Channel *c){
switch(c->istate){
case CHAN_INPUT_OPEN:
case CHAN_INPUT_WAIT_DRAIN:
packet_start(SSH_MSG_CHANNEL_INPUT_EOF);
packet_put_int(c->remote_id);
packet_send();
break;
default:
debug("internal error: channel %d: cannot send IEOF for istate %d",c->self,c->istate);
break;
}
}
static void
chan_send_oclose(Channel *c){
switch(c->ostate){
case CHAN_OUTPUT_OPEN:
case CHAN_OUTPUT_WAIT_DRAIN:
chan_shutdown_write(c);
buffer_consume(&c->output, buffer_len(&c->output));
packet_start(SSH_MSG_CHANNEL_OUTPUT_CLOSE);
packet_put_int(c->remote_id);
packet_send();
break;
default:
debug("internal error: channel %d: cannot send OCLOSE for ostate %d",c->self,c->istate);
break;
}
}
/* helper */
static void
chan_shutdown_write(Channel *c){
debug("channel %d: shutdown_write", c->self);
if(shutdown(c->sock, SHUT_WR)<0)
error("chan_shutdown_write failed for #%d/fd%d: %.100s",
c->self, c->sock, strerror(errno));
}
static void
chan_shutdown_read(Channel *c){
debug("channel %d: shutdown_read", c->self);
if(shutdown(c->sock, SHUT_RD)<0)
error("chan_shutdown_read failed for #%d/fd%d: %.100s",
c->self, c->sock, strerror(errno));
}
static void
chan_delele_if_full_closed(Channel *c){
if(c->istate==CHAN_INPUT_CLOSED && c->ostate==CHAN_OUTPUT_CLOSED){
debug("channel %d: closing", c->self);
channel_free(c->self);
}
}
void
chan_init_iostates(Channel *c){
c->ostate=CHAN_OUTPUT_OPEN;
c->istate=CHAN_INPUT_OPEN;
}
|
