int
dup(int oldfdnum, int newfdnum)
{
int i, r;
u_int ova, nva, pte;
struct Fd *oldfd, *newfd;
if ((r = fd_lookup(oldfdnum, &oldfd)) < 0) {
return r;
}
close(newfdnum);
newfd = (struct Fd *)INDEX2FD(newfdnum);
ova = fd2data(oldfd);
nva = fd2data(newfd);
if ((r = syscall_mem_map(0, (u_int)oldfd, 0, (u_int)newfd,
((*vpt)[VPN(oldfd)]) & (PTE_V | PTE_R | PTE_LIBRARY))) < 0) {
goto err;
}
if ((* vpd)[PDX(ova)]) {
for (i = 0; i < PDMAP; i += BY2PG) {
pte = (* vpt)[VPN(ova + i)];
if (pte & PTE_V) {
// should be no error here -- pd is already allocated
if ((r = syscall_mem_map(0, ova + i, 0, nva + i,
pte & (PTE_V | PTE_R | PTE_LIBRARY))) < 0) {
goto err;
}
}
}
}
return newfdnum;
err:
syscall_mem_unmap(0, (u_int)newfd);
for (i = 0; i < PDMAP; i += BY2PG) {
syscall_mem_unmap(0, nva + i);
}
return r;
}
void
serve(void)
{
u_int req, whom, perm;
for (;;) {
perm = 0;
req = ipc_recv(&whom, REQVA, &perm);
// All requests must contain an argument page
if (!(perm & PTE_V)) {
writef("Invalid request from %08x: no argument page\n",
whom);
continue; // just leave it hanging...
}
switch (req) {
case FSREQ_OPEN:
serve_open(whom, (struct Fsreq_open *)REQVA);
break;
case FSREQ_MAP:
serve_map(whom, (struct Fsreq_map *)REQVA);
break;
case FSREQ_SET_SIZE:
serve_set_size(whom, (struct Fsreq_set_size *)REQVA);
break;
case FSREQ_CLOSE:
serve_close(whom, (struct Fsreq_close *)REQVA);
break;
case FSREQ_DIRTY:
serve_dirty(whom, (struct Fsreq_dirty *)REQVA);
break;
case FSREQ_REMOVE:
serve_remove(whom, (struct Fsreq_remove *)REQVA);
break;
case FSREQ_SYNC:
serve_sync(whom);
break;
default:
writef("Invalid request code %d from %08x\n", whom, req);
break;
}
syscall_mem_unmap(0, REQVA);
}
}
void
fd_close(struct Fd *fd)
{
syscall_mem_unmap(0, (u_int)fd);
}