sys/src/cmd/disk/kfs/9p12.c

   1 #include "all.h"
   2
   3 static int
   4 readmsg(Chan *c, void *abuf, int n, int *ninep)
   5 {
   6         int fd, len;
   7         uchar *buf;
   8
   9         buf = abuf;
  10         fd = c->chan;
  11         qlock(&c->rlock);
  12         if(readn(fd, buf, 3) != 3){
  13                 qunlock(&c->rlock);
  14                 print("readn(3) fails: %r\n");
  15                 return -1;
  16         }
  17         if((50 <= buf[0] && buf[0] <= 87 && (buf[0]&1)==0 && GBIT16(buf+1) == 0xFFFF)
  18         || buf[0] == 86 /* Tattach */){
  19                 *ninep = 1;
  20                 /* assume message boundaries */
  21                 n = read(fd, buf+3, n-3);
  22                 if(n < 0){
  23                         qunlock(&c->rlock);
  24                         return -1;
  25                 }
  26                 return n+3;
  27         }
  28
  29         *ninep = 2;
  30         if(read(fd, buf+3, 1) != 1){
  31                 qunlock(&c->rlock);
  32                 print("read(1) fails: %r\n");
  33                 return -1;
  34         }
  35         len = GBIT32(buf);
  36         if(len > n){
  37                 print("msg too large\n");
  38                 qunlock(&c->rlock);
  39                 return -1;
  40         }
  41         if(readn(fd, buf+4, len-4) != len-4){
  42                 print("readn(%d) fails: %r\n", len-4);
  43                 qunlock(&c->rlock);
  44                 return -1;
  45         }
  46         qunlock(&c->rlock);
  47         return len;
  48 }
  49
  50 int
  51 startserveproc(void (*f)(Chan*, uchar*, int), char *name, Chan *c, uchar *b, int nb)
  52 {
  53         int pid;
  54
  55         switch(pid = rfork(RFMEM|RFPROC)){
  56         case -1:
  57                 panic("can't fork");
  58         case 0:
  59                 break;
  60         default:
  61                 return pid;
  62         }
  63         procname = name;
  64         f(c, b, nb);
  65         _exits(nil);
  66         return -1;      /* can't happen */
  67 }
  68
  69 void
  70 serve(Chan *chan)
  71 {
  72         int i, nin, p9, npid;
  73         uchar inbuf[1024];
  74         void (*s)(Chan*, uchar*, int);
  75         int *pid;
  76         Waitmsg *w;
  77
  78         p9 = 0;
  79         if((nin = readmsg(chan, inbuf, sizeof inbuf, &p9)) < 0)
  80                 return;
  81
  82         switch(p9){
  83         default:
  84                 print("unknown 9P type\n");
  85                 return;
  86         case 1:
  87                 s = serve9p1;
  88                 break;
  89         case 2:
  90                 s = serve9p2;
  91                 break;
  92         }
  93
  94         pid = malloc(sizeof(pid)*(conf.nserve-1));
  95         if(pid == nil)
  96                 return;
  97         for(i=1; i<conf.nserve; i++)
  98                 pid[i-1] = startserveproc(s, "srv", chan, nil, 0);
  99
 100         (*s)(chan, inbuf, nin);
 101
 102         /* wait till all other servers for this chan are done */
 103         for(npid = conf.nserve-1; npid > 0;){
 104                 w = wait();
 105                 if(w == 0)
 106                         break;
 107                 for(i = 0; i < conf.nserve-1; i++)
 108                         if(pid[i] == w->pid)
 109                                 npid--;
 110                 free(w);
 111         }
 112         free(pid);
 113 }
 114