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8bbd8b0ba2
l_start == 0 and l_len == 1 as we do l_len == 0.
208 lines
5.7 KiB
C
208 lines
5.7 KiB
C
/* Copyright (C) 1992-1997,1999,2000,2002 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <errno.h>
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#include <fcntl.h>
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#include <hurd.h>
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#include <hurd/fd.h>
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#include <stdarg.h>
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#include <sys/file.h> /* XXX for LOCK_* */
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/* Perform file control operations on FD. */
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int
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__libc_fcntl (int fd, int cmd, ...)
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{
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va_list ap;
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struct hurd_fd *d;
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int result;
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d = _hurd_fd_get (fd);
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if (d == NULL)
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return __hurd_fail (EBADF);
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va_start (ap, cmd);
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switch (cmd)
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{
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error_t err;
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default: /* Bad command. */
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errno = EINVAL;
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result = -1;
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break;
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/* First the descriptor-based commands, which do no RPCs. */
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case F_DUPFD: /* Duplicate the file descriptor. */
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{
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struct hurd_fd *new;
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io_t port, ctty;
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struct hurd_userlink ulink, ctty_ulink;
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int flags;
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HURD_CRITICAL_BEGIN;
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/* Extract the ports and flags from the file descriptor. */
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__spin_lock (&d->port.lock);
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flags = d->flags;
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ctty = _hurd_port_get (&d->ctty, &ctty_ulink);
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port = _hurd_port_locked_get (&d->port, &ulink); /* Unlocks D. */
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/* Get a new file descriptor. The third argument to __fcntl is the
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minimum file descriptor number for it. */
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new = _hurd_alloc_fd (&result, va_arg (ap, int));
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if (new == NULL)
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/* _hurd_alloc_fd has set errno. */
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result = -1;
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else
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{
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/* Give the ports each a user ref for the new descriptor. */
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__mach_port_mod_refs (__mach_task_self (), port,
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MACH_PORT_RIGHT_SEND, 1);
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if (ctty != MACH_PORT_NULL)
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__mach_port_mod_refs (__mach_task_self (), ctty,
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MACH_PORT_RIGHT_SEND, 1);
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/* Install the ports and flags in the new descriptor. */
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if (ctty != MACH_PORT_NULL)
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_hurd_port_set (&new->ctty, ctty);
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/* Duplication clears the FD_CLOEXEC flag. */
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new->flags = flags & ~FD_CLOEXEC;
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_hurd_port_locked_set (&new->port, port); /* Unlocks NEW. */
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}
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HURD_CRITICAL_END;
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_hurd_port_free (&d->port, &ulink, port);
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if (ctty != MACH_PORT_NULL)
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_hurd_port_free (&d->ctty, &ctty_ulink, port);
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break;
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}
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/* Set RESULT by evaluating EXPR with the descriptor locked.
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Check for an empty descriptor and return EBADF. */
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#define LOCKED(expr) \
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HURD_CRITICAL_BEGIN; \
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__spin_lock (&d->port.lock); \
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if (d->port.port == MACH_PORT_NULL) \
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result = __hurd_fail (EBADF); \
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else \
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result = (expr); \
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__spin_unlock (&d->port.lock); \
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HURD_CRITICAL_END;
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case F_GETFD: /* Get descriptor flags. */
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LOCKED (d->flags);
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break;
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case F_SETFD: /* Set descriptor flags. */
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LOCKED ((d->flags = va_arg (ap, int), 0));
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break;
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/* Now the real io operations, done by RPCs to io servers. */
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case F_GETLK:
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case F_SETLK:
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case F_SETLKW:
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{
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/* XXX
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We need new RPCs to support POSIX.1 fcntl file locking!!
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For the time being we support the whole-file case only,
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with all kinds of WRONG WRONG WRONG semantics,
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by using flock. This is definitely the Wrong Thing,
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but it might be better than nothing (?). */
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struct flock *fl = va_arg (ap, struct flock *);
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va_end (ap);
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switch (cmd)
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{
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case F_GETLK:
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errno = ENOSYS;
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return -1;
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case F_SETLK:
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cmd = LOCK_NB;
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break;
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default:
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cmd = 0;
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break;
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}
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switch (fl->l_type)
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{
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case F_RDLCK: cmd |= LOCK_SH; break;
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case F_WRLCK: cmd |= LOCK_EX; break;
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case F_UNLCK: cmd |= LOCK_UN; break;
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default:
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errno = EINVAL;
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return -1;
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}
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switch (fl->l_whence)
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{
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case SEEK_SET:
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if (fl->l_start == 0 && fl->l_len == 0) /* Whole file request. */
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break;
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/* It seems to be common for applications to lock the first
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byte of the file when they are really doing whole-file locking.
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So, since it's so wrong already, might as well do that too. */
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if (fl->l_start == 0 && fl->l_len == 1)
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break;
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/* FALLTHROUGH */
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case SEEK_CUR:
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case SEEK_END:
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errno = ENOTSUP;
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return -1;
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default:
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errno = EINVAL;
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return -1;
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}
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return __flock (fd, cmd);
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}
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case F_GETFL: /* Get per-open flags. */
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if (err = HURD_FD_PORT_USE (d, __io_get_openmodes (port, &result)))
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result = __hurd_dfail (fd, err);
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break;
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case F_SETFL: /* Set per-open flags. */
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err = HURD_FD_PORT_USE (d, __io_set_all_openmodes (port,
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va_arg (ap, int)));
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result = err ? __hurd_dfail (fd, err) : 0;
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break;
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case F_GETOWN: /* Get owner. */
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if (err = HURD_FD_PORT_USE (d, __io_get_owner (port, &result)))
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result = __hurd_dfail (fd, err);
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break;
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case F_SETOWN: /* Set owner. */
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err = HURD_FD_PORT_USE (d, __io_mod_owner (port, va_arg (ap, pid_t)));
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result = err ? __hurd_dfail (fd, err) : 0;
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break;
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}
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va_end (ap);
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return result;
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}
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libc_hidden_def (__libc_fcntl)
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weak_alias (__libc_fcntl, __fcntl)
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libc_hidden_weak (__fcntl)
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weak_alias (__libc_fcntl, fcntl)
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