| 1 | --- /dev/null 2016-12-11 08:33:21.825618476 +0530 |
| 2 | +++ ./cups/lockf.cpp 2016-12-11 09:44:20.050966252 +0530 |
| 3 | @@ -0,0 +1,89 @@ |
| 4 | +/* |
| 5 | + * Copyright (C) 2016 The Android Open Source Project |
| 6 | + * All rights reserved. |
| 7 | + * |
| 8 | + * Redistribution and use in source and binary forms, with or without |
| 9 | + * modification, are permitted provided that the following conditions |
| 10 | + * are met: |
| 11 | + * * Redistributions of source code must retain the above copyright |
| 12 | + * notice, this list of conditions and the following disclaimer. |
| 13 | + * * Redistributions in binary form must reproduce the above copyright |
| 14 | + * notice, this list of conditions and the following disclaimer in |
| 15 | + * the documentation and/or other materials provided with the |
| 16 | + * distribution. |
| 17 | + * |
| 18 | + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 19 | + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 20 | + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 21 | + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 22 | + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 23 | + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| 24 | + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| 25 | + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| 26 | + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| 27 | + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| 28 | + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 29 | + * SUCH DAMAGE. |
| 30 | + */ |
| 31 | +#include <unistd.h> |
| 32 | +#include <errno.h> |
| 33 | +#include <fcntl.h> |
| 34 | +#include <string.h> |
| 35 | + |
| 36 | +#ifndef _BITS_LOCKF_H_ |
| 37 | +#define _BITS_LOCKF_H_ |
| 38 | + |
| 39 | +#include <sys/cdefs.h> |
| 40 | + |
| 41 | +#define F_ULOCK 0 |
| 42 | +#define F_LOCK 1 |
| 43 | +#define F_TLOCK 2 |
| 44 | +#define F_TEST 3 |
| 45 | + |
| 46 | +__BEGIN_DECLS |
| 47 | + |
| 48 | +#if defined(__USE_FILE_OFFSET64) |
| 49 | +int lockf(int, int, off_t) __RENAME(lockf64); |
| 50 | +#else |
| 51 | +int lockf(int, int, off_t); |
| 52 | +#endif |
| 53 | +int lockf64(int, int, off64_t); |
| 54 | + |
| 55 | +__END_DECLS |
| 56 | + |
| 57 | +#endif |
| 58 | + |
| 59 | + |
| 60 | +int lockf64(int fd, int cmd, off64_t length) { |
| 61 | + // Translate POSIX lockf into fcntl. |
| 62 | + struct flock fl; |
| 63 | + memset(&fl, 0, sizeof(fl)); |
| 64 | + fl.l_whence = SEEK_CUR; |
| 65 | + fl.l_start = 0; |
| 66 | + fl.l_len = length; |
| 67 | + if (cmd == F_ULOCK) { |
| 68 | + fl.l_type = F_UNLCK; |
| 69 | + cmd = F_SETLK64; |
| 70 | + return fcntl(fd, F_SETLK64, &fl); |
| 71 | + } |
| 72 | + if (cmd == F_LOCK) { |
| 73 | + fl.l_type = F_WRLCK; |
| 74 | + return fcntl(fd, F_SETLKW64, &fl); |
| 75 | + } |
| 76 | + if (cmd == F_TLOCK) { |
| 77 | + fl.l_type = F_WRLCK; |
| 78 | + return fcntl(fd, F_SETLK64, &fl); |
| 79 | + } |
| 80 | + if (cmd == F_TEST) { |
| 81 | + fl.l_type = F_RDLCK; |
| 82 | + if (fcntl(fd, F_GETLK64, &fl) == -1) return -1; |
| 83 | + if (fl.l_type == F_UNLCK || fl.l_pid == getpid()) return 0; |
| 84 | + errno = EACCES; |
| 85 | + return -1; |
| 86 | + } |
| 87 | + errno = EINVAL; |
| 88 | + return -1; |
| 89 | +} |
| 90 | +int lockf(int fd, int cmd, off_t length) { |
| 91 | + return lockf64(fd, cmd, length); |
| 92 | +} |