sys/src/cmd/aux/listen1.c

   1 #include <u.h>
   2 #include <libc.h>
   3 #include <auth.h>
   4
   5 int verbose;
   6 int trusted;
   7
   8 void
   9 usage(void)
  10 {
  11         fprint(2, "usage: listen1 [-tv] address cmd args...\n");
  12         exits("usage");
  13 }
  14
  15 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*
  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
  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 }