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-rw-r--r--lib/libc/gen/readdir.c138
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.");