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
|
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/filio.h>
#include <sys/socket.h>
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#define MIN(a,b) ((a) < (b) ? (a) : (b))
int
relay(int fd1,
int fd2,
int (*callback)(char prefix, char *data, size_t nbytes))
{
fd_set readset;
int nfds, len;
char buffer[8192];
int fd1_eof = 0;
int fd2_eof = 0;
while (!fd1_eof || !fd2_eof)
{
/* Setup file descriptor set */
FD_ZERO(&readset);
if (!fd1_eof)
FD_SET(fd1, &readset);
if (!fd2_eof)
FD_SET(fd2, &readset);
nfds = select(MAX(fd1, fd2)+1,
&readset, NULL, NULL, NULL);
/* error? */
if (nfds < 0)
{
if (errno == EINTR)
continue;
return -1;
}
/* timeout? */
if (nfds == 0)
continue;
if (FD_ISSET(fd1, &readset))
{
long unread;
ioctl(fd1, FIONREAD, &unread);
do
{
if ((len = read(fd1, buffer, sizeof buffer)) < 0)
{
return -1;
}
unread -= len;
/* remote server close? */
if (len == 0)
{
shutdown(fd2, 1);
fd1_eof = 1;
}
callback('>', buffer, len);
write(fd2, buffer, len);
} while (unread > 0);
}
if (FD_ISSET(fd2, &readset))
{
long unread;
ioctl(fd2, FIONREAD, &unread);
do
{
if ((len = read(fd2, buffer, sizeof buffer)) < 0)
{
return -1;
}
unread -= len;
/* remote client close? */
if (len == 0)
{
shutdown(fd1, 1);
fd2_eof = 1;
}
callback('<', buffer, len);
write(fd1, buffer, len);
} while (unread > 0);
}
}
return 0;
}
|
