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/*
* linux/fs/fcntl.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include <linux/mm.h>
#include <linux/file.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
extern int sock_fcntl (struct file *, unsigned int cmd, unsigned long arg);
static inline int dupfd(unsigned int fd, unsigned int arg)
{
struct files_struct * files = current->files;
struct file * file;
int error;
error = -EINVAL;
if (arg >= NR_OPEN)
goto out;
error = -EBADF;
file = fget(fd);
if (!file)
goto out;
error = -EMFILE;
arg = find_next_zero_bit(&files->open_fds, NR_OPEN, arg);
if (arg >= current->rlim[RLIMIT_NOFILE].rlim_cur)
goto out_putf;
FD_SET(arg, &files->open_fds);
FD_CLR(arg, &files->close_on_exec);
fd_install(arg, file);
error = arg;
out:
return error;
out_putf:
fput(file);
goto out;
}
asmlinkage int sys_dup2(unsigned int oldfd, unsigned int newfd)
{
int err = -EBADF;
lock_kernel();
if (!fcheck(oldfd))
goto out;
err = newfd;
if (newfd == oldfd)
goto out;
err = -EBADF;
if (newfd >= NR_OPEN)
goto out; /* following POSIX.1 6.2.1 */
sys_close(newfd);
err = dupfd(oldfd, newfd);
out:
unlock_kernel();
return err;
}
asmlinkage int sys_dup(unsigned int fildes)
{
int ret;
lock_kernel();
ret = dupfd(fildes, 0);
unlock_kernel();
return ret;
}
#define SETFL_MASK (O_APPEND | O_NONBLOCK | O_NDELAY | FASYNC)
static int setfl(int fd, struct file * filp, unsigned long arg)
{
struct inode * inode = filp->f_dentry->d_inode;
/*
* In the case of an append-only file, O_APPEND
* cannot be cleared
*/
if (!(arg & O_APPEND) && IS_APPEND(inode))
return -EPERM;
/* Did FASYNC state change? */
if ((arg ^ filp->f_flags) & FASYNC) {
if (filp->f_op && filp->f_op->fasync)
filp->f_op->fasync(fd, filp, (arg & FASYNC) != 0);
}
/* required for strict SunOS emulation */
if (O_NONBLOCK != O_NDELAY)
if (arg & O_NDELAY)
arg |= O_NONBLOCK;
filp->f_flags = (arg & SETFL_MASK) | (filp->f_flags & ~SETFL_MASK);
return 0;
}
asmlinkage long sys_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg)
{
struct file * filp;
long err = -EBADF;
lock_kernel();
filp = fget(fd);
if (!filp)
goto out;
err = 0;
switch (cmd) {
case F_DUPFD:
err = dupfd(fd, arg);
break;
case F_GETFD:
err = FD_ISSET(fd, ¤t->files->close_on_exec);
break;
case F_SETFD:
if (arg&1)
FD_SET(fd, ¤t->files->close_on_exec);
else
FD_CLR(fd, ¤t->files->close_on_exec);
break;
case F_GETFL:
err = filp->f_flags;
break;
case F_SETFL:
err = setfl(fd, filp, arg);
break;
case F_GETLK:
err = fcntl_getlk(fd, (struct flock *) arg);
break;
case F_SETLK:
err = fcntl_setlk(fd, cmd, (struct flock *) arg);
break;
case F_SETLKW:
err = fcntl_setlk(fd, cmd, (struct flock *) arg);
break;
case F_GETOWN:
/*
* XXX If f_owner is a process group, the
* negative return value will get converted
* into an error. Oops. If we keep the
* current syscall conventions, the only way
* to fix this will be in libc.
*/
err = filp->f_owner.pid;
break;
case F_SETOWN:
err = 0;
filp->f_owner.pid = arg;
filp->f_owner.uid = current->uid;
filp->f_owner.euid = current->euid;
if (S_ISSOCK (filp->f_dentry->d_inode->i_mode))
err = sock_fcntl (filp, F_SETOWN, arg);
break;
case F_GETSIG:
err = filp->f_owner.signum;
break;
case F_SETSIG:
if (arg <= 0 || arg > _NSIG) {
err = -EINVAL;
break;
}
err = 0;
filp->f_owner.signum = arg;
break;
default:
/* sockets need a few special fcntls. */
if (S_ISSOCK (filp->f_dentry->d_inode->i_mode))
err = sock_fcntl (filp, cmd, arg);
else
err = -EINVAL;
break;
}
fput(filp);
out:
unlock_kernel();
return err;
}
static void send_sigio_to_task(struct task_struct *p,
struct fown_struct *fown, struct fasync_struct *fa)
{
if ((fown->euid != 0) &&
(fown->euid ^ p->suid) && (fown->euid ^ p->uid) &&
(fown->uid ^ p->suid) && (fown->uid ^ p->uid))
return;
switch (fown->signum) {
siginfo_t si;
default:
/* Queue a rt signal with the appropriate fd as its
value. We use SI_SIGIO as the source, not
SI_KERNEL, since kernel signals always get
delivered even if we can't queue. Failure to
queue in this case _should_ be reported; we fall
back to SIGIO in that case. --sct */
si.si_signo = fown->signum;
si.si_errno = 0;
si.si_code = SI_SIGIO;
si.si_pid = fown->pid;
si.si_uid = fown->uid;
si.si_fd = fa->fa_fd;
if (!send_sig_info(fown->signum, &si, p))
break;
/* fall-through: fall back on the old plain SIGIO signal */
case 0:
send_sig(SIGIO, p, 1);
}
}
static void send_sigio(struct fown_struct *fown, struct fasync_struct *fa)
{
struct task_struct * p;
int pid = fown->pid;
read_lock(&tasklist_lock);
if ( (pid > 0) && (p = find_task_by_pid(pid)) ) {
send_sigio_to_task(p, fown, fa);
goto out;
}
for_each_task(p) {
int match = p->pid;
if (pid < 0)
match = -p->pgrp;
if (pid != match)
continue;
send_sigio_to_task(p, fown, fa);
}
out:
read_unlock(&tasklist_lock);
}
void kill_fasync(struct fasync_struct *fa, int sig)
{
while (fa) {
struct fown_struct * fown;
if (fa->magic != FASYNC_MAGIC) {
printk("kill_fasync: bad magic number in "
"fasync_struct!\n");
return;
}
fown = &fa->fa_file->f_owner;
if (fown->pid)
send_sigio(fown, fa);
fa = fa->fa_next;
}
}
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