1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 1989 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 /* Copyright (c) 1984 AT&T */ 28 /* All Rights Reserved */ 29 30 #pragma ident "%Z%%M% %I% %E% SMI" 31 32 #include <fcntl.h> 33 #include <unistd.h> 34 #include <errno.h> 35 #include <sys/syscall.h> 36 37 /* 38 * convert lockf() into fcntl() for SystemV compatibility 39 */ 40 41 /* New SVR4 values */ 42 #define SV_GETLK 5 43 #define SV_SETLK 6 44 #define SV_SETLKW 7 45 46 lockf(fildes, function, size) 47 int fildes; 48 int function; 49 long size; 50 { 51 struct flock ld; 52 register int cmd; 53 54 cmd = SV_SETLK; /* assume non-blocking operation */ 55 ld.l_type = F_WRLCK; /* lockf() only deals with exclusive locks */ 56 ld.l_whence = 1; /* lock always starts at current position */ 57 if (size < 0) { 58 ld.l_start = size; 59 ld.l_len = -size; 60 } else { 61 ld.l_start = 0L; 62 ld.l_len = size; 63 } 64 65 switch (function) { 66 case F_TEST: 67 if (_syscall(SYS_fcntl, fildes, SV_GETLK, &ld) != -1) { 68 if (ld.l_type == F_UNLCK) { 69 ld.l_pid = ld.l_xxx; 70 /* l_pid is the last field in the 71 SVr3 flock structure */ 72 return (0); 73 } else 74 errno = EACCES; /* EAGAIN ?? */ 75 } 76 return (-1); 77 78 default: 79 errno = EINVAL; 80 return (-1); 81 82 /* the rest fall thru to the fcntl() at the end */ 83 case F_ULOCK: 84 ld.l_type = F_UNLCK; 85 break; 86 87 case F_LOCK: 88 cmd = SV_SETLKW; /* block, if not available */ 89 break; 90 91 case F_TLOCK: 92 break; 93 } 94 if (_syscall(SYS_fcntl, fildes, cmd, &ld) == -1) { 95 switch (errno) { 96 /* this hack is purported to be for /usr/group compatibility */ 97 case ENOLCK: 98 errno = EDEADLK; 99 } 100 return(-1); 101 } else { 102 ld.l_pid = ld.l_xxx; /* l_pid is the last field in the 103 SVr3 flock structure */ 104 return(0); 105 } 106 } 107