| 1 | /*
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| 2 | * Copyright (c) 2011 Petr Koupy
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| 3 | * All rights reserved.
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| 4 | *
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| 5 | * Redistribution and use in source and binary forms, with or without
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| 6 | * modification, are permitted provided that the following conditions
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| 7 | * are met:
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| 8 | *
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| 9 | * - Redistributions of source code must retain the above copyright
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| 10 | * notice, this list of conditions and the following disclaimer.
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| 11 | * - Redistributions in binary form must reproduce the above copyright
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| 12 | * notice, this list of conditions and the following disclaimer in the
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| 13 | * documentation and/or other materials provided with the distribution.
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| 14 | * - The name of the author may not be used to endorse or promote products
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| 15 | * derived from this software without specific prior written permission.
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| 16 | *
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 27 | */
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| 28 |
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| 29 | /** @addtogroup libposix
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| 30 | * @{
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| 31 | */
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| 32 | /** @file File control.
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| 33 | */
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| 34 |
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| 35 | #define LIBPOSIX_INTERNAL
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| 36 |
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| 37 | #include "internal/common.h"
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| 38 | #include "fcntl.h"
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| 39 |
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| 40 | #include "libc/unistd.h"
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| 41 | #include "libc/vfs/vfs.h"
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| 42 | #include "errno.h"
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| 43 |
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| 44 | /**
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| 45 | * Performs set of operations on the opened files.
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| 46 | *
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| 47 | * @param fd File descriptor of the opened file.
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| 48 | * @param cmd Operation to carry out.
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| 49 | * @return Non-negative on success. Might have special meaning corresponding
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| 50 | * to the requested operation.
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| 51 | */
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| 52 | int posix_fcntl(int fd, int cmd, ...)
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| 53 | {
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| 54 | int rc;
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| 55 | int flags;
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| 56 |
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| 57 | switch (cmd) {
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| 58 | case F_DUPFD:
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| 59 | case F_DUPFD_CLOEXEC: /* FD_CLOEXEC is not supported. */
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| 60 | /* VFS does not provide means to express constraints on the new
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| 61 | * file descriptor so the third argument is ignored. */
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| 62 |
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| 63 | /* Retrieve node triplet corresponding to the file descriptor. */
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| 64 | /* Empty statement after label. */;
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| 65 | fdi_node_t node;
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| 66 | rc = fd_node(fd, &node);
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| 67 | if (rc != EOK) {
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| 68 | errno = -rc;
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| 69 | return -1;
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| 70 | }
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| 71 |
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| 72 | /* Reopen the node so the fresh file descriptor is generated. */
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| 73 | int newfd = open_node(&node, 0);
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| 74 | if (newfd < 0) {
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| 75 | errno = -newfd;
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| 76 | return -1;
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| 77 | }
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| 78 |
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| 79 | /* Associate the newly generated descriptor to the file description
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| 80 | * of the old file descriptor. Just reopened node will be automatically
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| 81 | * closed. */
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| 82 | rc = dup2(fd, newfd);
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| 83 | if (rc != EOK) {
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| 84 | errno = -rc;
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| 85 | return -1;
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| 86 | }
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| 87 |
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| 88 | return newfd;
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| 89 | case F_GETFD:
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| 90 | /* FD_CLOEXEC is not supported. There are no other flags. */
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| 91 | return 0;
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| 92 | case F_SETFD:
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| 93 | /* FD_CLOEXEC is not supported. Ignore arguments and report success. */
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| 94 | return 0;
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| 95 | case F_GETFL:
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| 96 | /* File status flags (i.e. O_APPEND) are currently private to the
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| 97 | * VFS server so it cannot be easily retrieved. */
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| 98 | flags = 0;
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| 99 | /* File access flags are currently not supported for file descriptors.
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| 100 | * Provide full access. */
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| 101 | flags |= O_RDWR;
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| 102 | return flags;
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| 103 | case F_SETFL:
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| 104 | /* File access flags are currently not supported for file descriptors.
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| 105 | * Ignore arguments and report success. */
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| 106 | return 0;
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| 107 | case F_GETOWN:
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| 108 | case F_SETOWN:
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| 109 | case F_GETLK:
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| 110 | case F_SETLK:
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| 111 | case F_SETLKW:
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| 112 | /* Signals (SIGURG) and file locks are not supported. */
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| 113 | errno = ENOTSUP;
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| 114 | return -1;
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| 115 | default:
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| 116 | /* Unknown command */
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| 117 | errno = EINVAL;
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| 118 | return -1;
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| 119 | }
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| 120 | }
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| 121 |
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| 122 | /** @}
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| 123 | */
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