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
|
#include <sys/socket.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <stdio.h>
#include <time.h>
#include <err.h>
#include "tunnel.h"
#include "macro.h"
#include "utils.h"
static time_t since;
static void tunnel_daemon_atexit(void)
{
unlink(TUNNEL_SOCK_PATH);
}
static void sighandler(int signo __unused)
{
exit(EXIT_FAILURE);
}
static char **parse_args(char *buf, int len)
{
char **args = NULL;
while (len) {
addv(&args, buf);
char *p = memchr(buf, '\0', len);
if (!p)
break;
len -= p - buf + 1;
buf = p + 1;
}
return args;
}
static void echo(FILE *fp, char **args)
{
for (int n = 0; args[n]; n++)
fprintf(fp, "%s%s", n ? " " : "", args[n]);
}
static void tunnel_daemon_loop(int sock)
{
bool alive = true;
while (alive) {
char msg[1024];
int len;
int fd = accept(sock, NULL, NULL);
if (fd < 0) {
warn("accept");
continue;
}
len = read(fd, msg, sizeof(msg) - 1);
if (len < 0) {
warn("read");
close(fd);
continue;
}
if (! len) {
close(fd);
continue;
}
msg[len] = '\0';
char **args = parse_args(msg, len);
let (fp, fdopen(fd, "w"), fclose) {
char *cmd = *args;
if (strequal(cmd, "echo"))
echo(fp, args + 1);
else if (strequal(cmd, "hello"))
fprintf(fp, "hello from %d", getpid());
else if (strequal(cmd, "alive"))
fprintf(fp, "since %s", ctime(&since));
else if (strequal(cmd, "stop")) {
fprintf(fp, "ok");
alive = false;
} else
fprintf(fp, "what do you want?");
}
free(args);
}
}
bool tunnel_daemon(int sock)
{
switch (fork()) {
case -1:
warn("fork");
return false;
case 0:
break;
default:
return true;
}
if (setsid() < 0)
err(EXIT_FAILURE, "setsid");
chdir("/");
struct sigaction sa = {
.sa_handler = sighandler
};
sigaction(SIGTERM, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
#if 0
int fd = open("/dev/null", O_RDWR);
if (fd < 0)
err(EXIT_FAILURE, "open /dev/null");
dup2(fd, STDIN_FILENO);
dup2(fd, STDOUT_FILENO);
dup2(fd, STDERR_FILENO);
if (fd > 2)
close(fd);
#endif
time(&since);
atexit(tunnel_daemon_atexit);
tunnel_daemon_loop(sock);
exit(EXIT_SUCCESS);
return true;
}
|
