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2001/0214
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#include <u.h>
#include <libc.h>
#include <auth.h>
#include <fcall.h>
#include <ip.h>
#include "boot.h"
/*
* reassemble 9P messages for stream based protocols
* interposed between devmnt and the network by srv for tcp connections
* fcall expects devmnt on fd0, network fd1
*/
static uchar msglen[256] =
{
[Tnop] 3,
[Rnop] 3,
[Tsession] 3+CHALLEN,
[Rsession] 3+NAMELEN+DOMLEN+CHALLEN,
[Terror] 0,
[Rerror] 67,
[Tflush] 5,
[Rflush] 3,
[Tattach] 5+2*NAMELEN+TICKETLEN+AUTHENTLEN,
[Rattach] 13+AUTHENTLEN,
[Tclone] 7,
[Rclone] 5,
[Twalk] 33,
[Rwalk] 13,
[Topen] 6,
[Ropen] 13,
[Tcreate] 38,
[Rcreate] 13,
[Tread] 15,
[Rread] 8,
[Twrite] 16,
[Rwrite] 7,
[Tclunk] 5,
[Rclunk] 5,
[Tremove] 5,
[Rremove] 5,
[Tstat] 5,
[Rstat] 121,
[Twstat] 121,
[Rwstat] 5,
[Tclwalk] 35,
[Rclwalk] 13,
};
enum
{
Twritehdr = 16, /* Min bytes for Twrite */
Rreadhdr = 8, /* Min bytes for Rread */
Twritecnt = 13, /* Offset in byte stream of write count */
Rreadcnt = 5, /* Offset for Readcnt */
};
void
echo(int f, int t)
{
int n;
char buf[MAXRPC];
for(;;) {
n = read9p(f, buf, MAXRPC);
if(n <= 0)
break;
if(write(t, buf, n) < n)
break;
}
}
int
mntrpclen(uchar *d, int n)
{
uchar t;
int len, off;
if(n < 1)
return 0;
t = d[0];
switch(t) { /* This is the type */
default:
len = msglen[t];
if(len == 0) /* Illegal type so consume */
return n;
if(n < len)
return 0;
return len;
case Twrite: /* Fmt: TGGFFOOOOOOOOCC */
len = Twritehdr; /* T = type, G = tag, F = fid */
off = Twritecnt; /* O = offset, C = count */
break;
case Rread: /* Fmt: TGGFFCC */
len = Rreadhdr;
off = Rreadcnt;
break;
}
if(n < off+2)
return 0;
len += d[off]|(d[off+1]<<8);
if(n < len)
return 0;
return len;
}
int
pushfcall(int fd)
{
int r, n, l, pfd[2];
uchar *p, buf[MAXRPC];
if(pipe(pfd) < 0){
fprint(2, "pipe: %r\n");
exits("pipe");
}
/* Downstream is just a copy process */
switch(rfork(RFPROC|RFFDG|RFMEM)){
case 0:
close(pfd[1]);
echo(pfd[0], fd);
fprint(2, "echo finished\n");
exits("echo done");
case -1:
fprint(2, "fcall fork failed: %r\n");
exits("fork");
}
switch(rfork(RFPROC|RFFDG|RFMEM)){
default:
close(pfd[0]);
return pfd[1];
case 0:
close(pfd[1]);
break;
case -1:
fprint(2, "fcall fork failed: %r\n");
exits("fork");
}
/* Dispatch only full RPC's to the mount driver */
l = MAXRPC;
p = buf;
for(;;) {
n = read(fd, p, l);
if(n < 0)
break;
p += n;
l -= n;
for(;;) {
r = mntrpclen(buf, p - buf);
if(r == 0)
break;
if(write(pfd[0], buf, r) < 0)
break;
n = (p - buf) - r;
memmove(buf, buf+r, n);
p = buf+n;
l = MAXRPC - n;
}
}
abort();
return 0;
}
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