conterm/libc/read9pmsg.c

32 lines
462 B
C

#include <u.h>
#include <libc.h>
#include <fcall.h>
int
read9pmsg(int fd, void *abuf, uint n)
{
int m, len;
uchar *buf;
buf = abuf;
/* read count */
m = readn(fd, buf, BIT32SZ);
if(m != BIT32SZ){
if(m < 0)
return -1;
return 0;
}
len = GBIT32(buf);
if(len <= BIT32SZ || len > n){
werrstr("bad length in 9P2000 message header");
return -1;
}
len -= BIT32SZ;
m = readn(fd, buf+BIT32SZ, len);
if(m < len)
return 0;
return BIT32SZ+m;
}