diff options
Diffstat (limited to 'lib/libc/gen/readdir.c')
-rw-r--r-- | lib/libc/gen/readdir.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/lib/libc/gen/readdir.c b/lib/libc/gen/readdir.c new file mode 100644 index 000000000000..94d2b2e8d877 --- /dev/null +++ b/lib/libc/gen/readdir.c @@ -0,0 +1,138 @@ +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 1983, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "namespace.h" +#include <sys/param.h> +#include <dirent.h> +#include <errno.h> +#include <string.h> +#include <pthread.h> +#include "un-namespace.h" + +#include "libc_private.h" +#include "gen-private.h" +#include "telldir.h" + +/* + * get next entry in a directory. + */ +struct dirent * +_readdir_unlocked(DIR *dirp, int flags) +{ + struct dirent *dp; + off_t initial_seek; + size_t initial_loc = 0; + ssize_t ret; + + for (;;) { + if (dirp->dd_loc >= dirp->dd_size) { + if (dirp->dd_flags & __DTF_READALL) + return (NULL); + initial_loc = dirp->dd_loc; + dirp->dd_flags &= ~__DTF_SKIPREAD; + dirp->dd_loc = 0; + } + if (dirp->dd_loc == 0 && + !(dirp->dd_flags & (__DTF_READALL | __DTF_SKIPREAD))) { + dirp->dd_size = 0; + initial_seek = dirp->dd_seek; + ret = _getdirentries(dirp->dd_fd, + dirp->dd_buf, dirp->dd_len, &dirp->dd_seek); + if (ret <= 0) + return (NULL); + dirp->dd_size = (size_t)ret; + _fixtelldir(dirp, initial_seek, initial_loc); + } + dirp->dd_flags &= ~__DTF_SKIPREAD; + dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc); + if ((long)dp & 03L) /* bogus pointer check */ + return (NULL); + if (dp->d_reclen <= 0 || + dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc) + return (NULL); + dirp->dd_loc += dp->d_reclen; + if (dp->d_ino == 0 && (flags & RDU_SKIP) != 0) + continue; + if (dp->d_type == DT_WHT && (dirp->dd_flags & DTF_HIDEW)) + continue; + if (dp->d_namlen >= sizeof(dp->d_name) && + (flags & RDU_SHORT) != 0) + continue; + return (dp); + } +} + +struct dirent * +readdir(DIR *dirp) +{ + struct dirent *dp; + + if (__isthreaded) + _pthread_mutex_lock(&dirp->dd_lock); + dp = _readdir_unlocked(dirp, RDU_SKIP); + if (__isthreaded) + _pthread_mutex_unlock(&dirp->dd_lock); + return (dp); +} + +int +__readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result) +{ + struct dirent *dp; + int saved_errno; + + saved_errno = errno; + errno = 0; + if (__isthreaded) + _pthread_mutex_lock(&dirp->dd_lock); + dp = _readdir_unlocked(dirp, RDU_SKIP | RDU_SHORT); + if (dp != NULL) + memcpy(entry, dp, _GENERIC_DIRSIZ(dp)); + if (__isthreaded) + _pthread_mutex_unlock(&dirp->dd_lock); + + if (errno != 0) { + if (dp == NULL) + return (errno); + } else + errno = saved_errno; + + if (dp != NULL) + *result = entry; + else + *result = NULL; + + return (0); +} + +__strong_reference(__readdir_r, readdir_r); +__warn_references(readdir_r, + "warning: this program uses readdir_r(), which is unsafe."); |