1/* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. 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 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30#if defined(LIBC_SCCS) && !defined(lint) 31static char sccsid[] = "@(#)telldir.c 8.1 (Berkeley) 6/4/93"; 32#endif /* LIBC_SCCS and not lint */ 33#include <sys/cdefs.h> 34__FBSDID("$FreeBSD: src/lib/libc/gen/telldir.c,v 1.11 2008/05/05 14:05:23 kib Exp $"); 35 36#include "namespace.h" 37#include <sys/param.h> 38#include <sys/queue.h> 39#include <dirent.h> 40#include <pthread.h> 41#include <stdlib.h> 42#include <unistd.h> 43#include "un-namespace.h" 44 45#include "libc_private.h" 46#include "telldir.h" 47 48/* 49 * The option SINGLEUSE may be defined to say that a telldir 50 * cookie may be used only once before it is freed. This option 51 * is used to avoid having memory usage grow without bound. 52 */ 53#if !__DARWIN_UNIX03 54#define SINGLEUSE 55#endif /* !__DARWIN_UNIX03 */ 56 57/* 58 * return a pointer into a directory 59 */ 60long 61telldir(dirp) 62 DIR *dirp; 63{ 64 struct ddloc *lp; 65 66#if __DARWIN_UNIX03 67 if (__isthreaded) 68 _pthread_mutex_lock(&dirp->dd_lock); 69 LIST_FOREACH(lp, &dirp->dd_td->td_locq, loc_lqe) { 70 if ( 71#if __DARWIN_64_BIT_INO_T 72 (lp->loc_seek == dirp->dd_td->seekoff) 73#else /* !__DARWIN_64_BIT_INO_T */ 74 (lp->loc_seek == dirp->dd_seek) 75#endif /* __DARWIN_64_BIT_INO_T */ 76 && (lp->loc_loc == dirp->dd_loc)) 77 goto found; 78 } 79 if ((lp = (struct ddloc *)malloc(sizeof(struct ddloc))) == NULL) { 80 if (__isthreaded) 81 _pthread_mutex_unlock(&dirp->dd_lock); 82 return (-1); 83 } 84#else /* !__DARWIN_UNIX03 */ 85 if ((lp = (struct ddloc *)malloc(sizeof(struct ddloc))) == NULL) 86 return (-1); 87 if (__isthreaded) 88 _pthread_mutex_lock(&dirp->dd_lock); 89#endif /* __DARWIN_UNIX03 */ 90 lp->loc_index = dirp->dd_td->td_loccnt++; 91#if __DARWIN_64_BIT_INO_T 92 lp->loc_seek = dirp->dd_td->seekoff; 93#else /* !__DARWIN_64_BIT_INO_T */ 94 lp->loc_seek = dirp->dd_seek; 95#endif /* __DARWIN_64_BIT_INO_T */ 96 lp->loc_loc = dirp->dd_loc; 97 LIST_INSERT_HEAD(&dirp->dd_td->td_locq, lp, loc_lqe); 98#if __DARWIN_UNIX03 99found: 100#endif /* __DARWIN_UNIX03 */ 101 if (__isthreaded) 102 _pthread_mutex_unlock(&dirp->dd_lock); 103 return (lp->loc_index); 104} 105 106/* 107 * seek to an entry in a directory. 108 * Only values returned by "telldir" should be passed to seekdir. 109 */ 110void 111_seekdir(dirp, loc) 112 DIR *dirp; 113 long loc; 114{ 115 struct ddloc *lp; 116 struct dirent *dp; 117 118 LIST_FOREACH(lp, &dirp->dd_td->td_locq, loc_lqe) { 119 if (lp->loc_index == loc) 120 break; 121 } 122 if (lp == NULL) 123 return; 124 if (lp->loc_loc == dirp->dd_loc && 125#if __DARWIN_64_BIT_INO_T 126 lp->loc_seek == dirp->dd_td->seekoff 127#else /* !__DARWIN_64_BIT_INO_T */ 128 lp->loc_seek == dirp->dd_seek 129#endif /* __DARWIN_64_BIT_INO_T */ 130 ) 131 goto found; 132 (void) lseek(dirp->dd_fd, (off_t)lp->loc_seek, SEEK_SET); 133#if __DARWIN_64_BIT_INO_T 134 dirp->dd_td->seekoff = lp->loc_seek; 135#else /* !__DARWIN_64_BIT_INO_T */ 136 dirp->dd_seek = lp->loc_seek; 137#endif /* __DARWIN_64_BIT_INO_T */ 138 dirp->dd_loc = 0; 139 while (dirp->dd_loc < lp->loc_loc) { 140 dp = _readdir_unlocked(dirp, 0); 141 if (dp == NULL) 142 break; 143 } 144found:; 145#ifdef SINGLEUSE 146 LIST_REMOVE(lp, loc_lqe); 147 free((caddr_t)lp); 148#endif 149} 150 151#ifndef BUILDING_VARIANT 152/* 153 * Reclaim memory for telldir cookies which weren't used. 154 */ 155void 156_reclaim_telldir(dirp) 157 DIR *dirp; 158{ 159 struct ddloc *lp; 160 struct ddloc *templp; 161 162 lp = LIST_FIRST(&dirp->dd_td->td_locq); 163 while (lp != NULL) { 164 templp = lp; 165 lp = LIST_NEXT(lp, loc_lqe); 166 free(templp); 167 } 168 LIST_INIT(&dirp->dd_td->td_locq); 169} 170#endif /* !BUILDING_VARIANT */ 171