1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <unistd.h> 30 31 #include <errno.h> 32 #include <fcntl.h> 33 #include <string.h> 34 35 int lockf64(int fd, int cmd, off64_t length) { 36 // Translate POSIX lockf into fcntl. 37 struct flock64 fl; 38 memset(&fl, 0, sizeof(fl)); 39 fl.l_whence = SEEK_CUR; 40 fl.l_start = 0; 41 fl.l_len = length; 42 43 if (cmd == F_ULOCK) { 44 fl.l_type = F_UNLCK; 45 cmd = F_SETLK64; 46 return fcntl(fd, F_SETLK64, &fl); 47 } 48 49 if (cmd == F_LOCK) { 50 fl.l_type = F_WRLCK; 51 return fcntl(fd, F_SETLKW64, &fl); 52 } 53 54 if (cmd == F_TLOCK) { 55 fl.l_type = F_WRLCK; 56 return fcntl(fd, F_SETLK64, &fl); 57 } 58 59 if (cmd == F_TEST) { 60 fl.l_type = F_RDLCK; 61 if (fcntl(fd, F_GETLK64, &fl) == -1) return -1; 62 if (fl.l_type == F_UNLCK || fl.l_pid == getpid()) return 0; 63 errno = EACCES; 64 return -1; 65 } 66 67 errno = EINVAL; 68 return -1; 69 } 70 71 int lockf(int fd, int cmd, off_t length) { 72 return lockf64(fd, cmd, length); 73 } 74
