long
sys_close(SyscallFrame *f)
{
int fd;
File *file;
if (argfd(f, 0, &fd)) {
// todo errstr
return -1;
}
file = proc->files[fd];
releasefile(file);
proc->files[fd] = nil;
return 0;
}
static File *
getfile(char *fname)
{
File *f = allocfile();
if (f == nil)
return nil;
if (strcmp(fname, "/hello.txt") == 0) {
initfile(f, hello, strlen(hello));
} else if (strcmp(fname, "/dev/cons") == 0) {
consfile(f);
} else {
releasefile(f);
f = nil;
}
return f;
}
int
sys_open(SyscallFrame *f)
{
char *fname;
long l;
int omode, fd;
File *file;
if (argstr(f, 0, &fname) < 0)
return -1;
if (arglong(f, 1, &l) < 0)
return -1;
omode = (long)l;
if (omode & (OEXEC | OTRUNC | OCEXEC | ORCLOSE)) {
// todo errstr
return -1;
}
if (omode & (OWRITE | ORDWR) && !canwrite(fname)) {
// todo errstr
return -1;
}
file = getfile(fname);
if (file == nil)
return -1;
file->omode = omode;
fd = allocfd(proc, file);
if (fd == -1) {
// todo errstr
releasefile(file);
return -1;
}
return fd;
}
/*
* return a block of a tar file
*/
int
mktar(Dfile *df, Symbol *dp, uchar *area, uint offset, int len)
{
int fd, i, j, n, off;
uchar *p, *buf;
uchar *vec;
File *f;
f = &df->file[dp->fno];
vec = f->refvec;
p = area;
/* find file */
for(i = 0; i < df->nfile && len > 0; i++){
if((vec[i/8] & (1<<(i&7))) == 0)
continue;
f = &df->file[i];
n = Tblocksize + ((f->len + Tblocksize - 1)/Tblocksize)*Tblocksize;
if(offset >= n){
offset -= n;
continue;
}
if(offset < Tblocksize){
buf = mktardir(f);
if(offset + len > Tblocksize)
j = Tblocksize - offset;
else
j = len;
//if(debug)fprint(2, "reading %d bytes dir of %s\n", j, f->name);
memmove(p, buf+offset, j);
p += j;
len -= j;
offset += j;
free(buf);
}
if(len <= 0)
break;
off = offset - Tblocksize;
if(off >= 0 && off < f->len){
if(off + len > f->len)
j = f->len - off;
else
j = len;
fd = getfile(df, f);
if(fd >= 0){
//if(debug)fprint(2, "reading %d bytes from offset %d of %s\n", j, off, f->name);
if(pread(fd, p, j, off) != j)
syslog(0, dependlog, "%r reading %d bytes from offset %d of %s", j, off, f->name);
}
releasefile(f);
p += j;
len -= j;
offset += j;
}
if(len <= 0)
break;
if(offset < n){
if(offset + len > n)
j = n - offset;
else
j = len;
//if(debug)fprint(2, "filling %d bytes after %s\n", j, f->name);
memset(p, 0, j);
p += j;
len -= j;
}
offset = 0;
}
/* null blocks at end of tar file */
if(offset < 2*Tblocksize && len > 0){
if(offset + len > 2*Tblocksize)
j = 2*Tblocksize - offset;
else
j = len;
//if(debug)fprint(2, "filling %d bytes at end\n", j);
memset(p, 0, j);
p += j;
}
return p - area;
}
