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
|
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <task.h>
#include <stdlib.h>
#include <sys/socket.h>
enum
{
STACK = 32768
};
char *server;
int port;
void proxytask(void*);
void rwtask(void*);
int*
mkfd2(int fd1, int fd2)
{
int *a;
a = malloc(2*sizeof a[0]);
if(a == 0){
fprintf(stderr, "out of memory\n");
abort();
}
a[0] = fd1;
a[1] = fd2;
return a;
}
void
taskmain(int argc, char **argv)
{
int cfd, fd;
int rport;
char remote[16];
if(argc != 4){
fprintf(stderr, "usage: tcpproxy localport server remoteport\n");
taskexitall(1);
}
server = argv[2];
port = atoi(argv[3]);
if((fd = netannounce(TCP, 0, atoi(argv[1]))) < 0){
fprintf(stderr, "cannot announce on tcp port %d: %s\n", atoi(argv[1]), strerror(errno));
taskexitall(1);
}
fdnoblock(fd);
while((cfd = netaccept(fd, remote, &rport)) >= 0){
fprintf(stderr, "connection from %s:%d\n", remote, rport);
taskcreate(proxytask, (void*)cfd, STACK);
}
}
void
proxytask(void *v)
{
int fd, remotefd;
fd = (int)v;
if((remotefd = netdial(TCP, server, port)) < 0){
close(fd);
return;
}
fprintf(stderr, "connected to %s:%d\n", server, port);
taskcreate(rwtask, mkfd2(fd, remotefd), STACK);
taskcreate(rwtask, mkfd2(remotefd, fd), STACK);
}
void
rwtask(void *v)
{
int *a, rfd, wfd, n;
char buf[2048];
a = v;
rfd = a[0];
wfd = a[1];
free(a);
while((n = fdread(rfd, buf, sizeof buf)) > 0)
fdwrite(wfd, buf, n);
shutdown(wfd, SHUT_WR);
close(rfd);
}
|
