1 #include <u.h>
2 #include <libc.h>
3 #include <auth.h>
4
5 int verbose;
6 int trusted;
7
8 void
usage(void)9 usage(void)
10 {
11 fprint(2, "usage: listen1 [-tv] address cmd args...\n");
12 exits("usage");
13 }
14
15 void
becomenone(void)16 becomenone(void)
17 {
18 int fd;
19
20 fd = open("#c/user", OWRITE);
21 if(fd < 0 || write(fd, "none", strlen("none")) < 0)
22 sysfatal("can't become none: %r");
23 close(fd);
24 if(newns("none", nil) < 0)
25 sysfatal("can't build namespace: %r");
26 }
27
28 char*
remoteaddr(char * dir)29 remoteaddr(char *dir)
30 {
31 static char buf[128];
32 char *p;
33 int n, fd;
34
35 snprint(buf, sizeof buf, "%s/remote", dir);
36 fd = open(buf, OREAD);
37 if(fd < 0)
38 return "";
39 n = read(fd, buf, sizeof(buf));
40 close(fd);
41 if(n > 0){
42 buf[n] = 0;
43 p = strchr(buf, '!');
44 if(p)
45 *p = 0;
46 return buf;
47 }
48 return "";
49 }
50
51 void
main(int argc,char ** argv)52 main(int argc, char **argv)
53 {
54 char data[60], dir[40], ndir[40];
55 int ctl, nctl, fd;
56
57 ARGBEGIN{
58 default:
59 usage();
60 case 't':
61 trusted = 1;
62 break;
63 case 'v':
64 verbose = 1;
65 break;
66 }ARGEND
67
68 if(argc < 2)
69 usage();
70
71 if(!verbose){
72 close(1);
73 fd = open("/dev/null", OWRITE);
74 if(fd != 1){
75 dup(fd, 1);
76 close(fd);
77 }
78 }
79
80 if(!trusted)
81 becomenone();
82
83 print("listen started\n");
84 ctl = announce(argv[0], dir);
85 if(ctl < 0)
86 sysfatal("announce %s: %r", argv[0]);
87
88 for(;;){
89 nctl = listen(dir, ndir);
90 if(nctl < 0)
91 sysfatal("listen %s: %r", argv[0]);
92
93 switch(rfork(RFFDG|RFPROC|RFNOWAIT|RFENVG|RFNAMEG|RFNOTEG)){
94 case -1:
95 reject(nctl, ndir, "host overloaded");
96 close(nctl);
97 continue;
98 case 0:
99 fd = accept(nctl, ndir);
100 if(fd < 0){
101 fprint(2, "accept %s: can't open %s/data: %r\n",
102 argv[0], ndir);
103 _exits(0);
104 }
105 print("incoming call for %s from %s in %s\n", argv[0],
106 remoteaddr(ndir), ndir);
107 fprint(nctl, "keepalive");
108 close(ctl);
109 close(nctl);
110 putenv("net", ndir);
111 snprint(data, sizeof data, "%s/data", ndir);
112 bind(data, "/dev/cons", MREPL);
113 dup(fd, 0);
114 dup(fd, 1);
115 dup(fd, 2);
116 close(fd);
117 exec(argv[1], argv+1);
118 if(argv[1][0] != '/')
119 exec(smprint("/bin/%s", argv[1]), argv+1);
120 fprint(2, "%s: exec: %r\n", argv0);
121 exits(nil);
122 default:
123 close(nctl);
124 break;
125 }
126 }
127 }
128