X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Ftar;a=blobdiff_plain;f=src%2Fmisc.c;h=e92c8aa830e36fe2fca6cd25aeaf9f107d7b6bac;hp=64b1b2b3ea8b4104cff3a85d4d3ba14312b33a4b;hb=45ccda119355a1087450039a250359c1d0de0d08;hpb=d9458886432a92230e432e8e8492703c7afb8272
diff --git a/src/misc.c b/src/misc.c
index 64b1b2b..e92c8aa 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -1,7 +1,7 @@
/* Miscellaneous functions, not really specific to GNU tar.
- Copyright (C) 1988, 1992, 1994, 1995, 1996, 1997, 1999, 2000, 2001,
- 2003, 2004, 2005, 2006, 2007, 2009, 2010 Free Software Foundation, Inc.
+ Copyright 1988, 1992, 1994-1997, 1999-2001, 2003-2007, 2009-2010,
+ 2012-2014 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
@@ -14,21 +14,23 @@
Public License for more details.
You should have received a copy of the GNU General Public License along
- with this program; if not, write to the Free Software Foundation, Inc.,
- 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+ with this program. If not, see . */
+#define COMMON_INLINE _GL_EXTERN_INLINE
#include
#include
#include "common.h"
#include
-#include
#include
#include
+#include
#ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT
# define DOUBLE_SLASH_IS_DISTINCT_ROOT 0
#endif
+static const char *tar_getcdpath (int);
+
/* Handling strings. */
@@ -37,8 +39,7 @@
void
assign_string (char **string, const char *value)
{
- if (*string)
- free (*string);
+ free (*string);
*string = value ? xstrdup (value) : 0;
}
@@ -106,7 +107,7 @@ quote_copy_string (const char *string)
completes the unquoting anyway.
This is used for reading the saved directory file in incremental
- dumps. It is used for decoding old `N' records (demangling names).
+ dumps. It is used for decoding old 'N' records (demangling names).
But also, it is used for decoding file arguments, would they come
from the shell or a -T file, and for decoding the --exclude
argument. */
@@ -230,11 +231,12 @@ zap_slashes (char *name)
}
/* Normalize FILE_NAME by removing redundant slashes and "."
- components, including redundant trailing slashes. Leave ".."
- alone, as it may be significant in the presence of symlinks and on
- platforms where "/.." != "/". Destructive version: modifies its
- argument. */
-static void
+ components, including redundant trailing slashes.
+ Leave ".." alone, as it may be significant in the presence
+ of symlinks and on platforms where "/.." != "/".
+
+ Destructive version: modifies its argument. */
+void
normalize_filename_x (char *file_name)
{
char *name = file_name + FILE_SYSTEM_PREFIX_LEN (file_name);
@@ -268,37 +270,41 @@ normalize_filename_x (char *file_name)
}
/* Normalize NAME by removing redundant slashes and "." components,
- including redundant trailing slashes. Return a normalized
- newly-allocated copy. */
+ including redundant trailing slashes.
+
+ Return a normalized newly-allocated copy. */
char *
-normalize_filename (const char *name)
+normalize_filename (int cdidx, const char *name)
{
char *copy = NULL;
if (IS_RELATIVE_FILE_NAME (name))
{
- /* Set COPY to the absolute file name if possible.
+ /* Set COPY to the absolute path for this name.
FIXME: There should be no need to get the absolute file name.
- getcwd is slow, it might fail, and it does not necessarily
- return a canonical name even when it succeeds. Perhaps we
- can use dev+ino pairs instead of names? */
- copy = xgetcwd ();
- if (copy)
- {
- size_t copylen = strlen (copy);
- bool need_separator = ! (DOUBLE_SLASH_IS_DISTINCT_ROOT
- && copylen == 2 && ISSLASH (copy[1]));
- copy = xrealloc (copy, copylen + need_separator + strlen (name) + 1);
- copy[copylen] = DIRECTORY_SEPARATOR;
- strcpy (copy + copylen + need_separator, name);
- }
- else
- WARN ((0, errno, _("Cannot get working directory")));
+ tar_getcdpath does not return a true "canonical" path, so
+ this following approach may lead to situations where the same
+ file or directory is processed twice under different absolute
+ paths without that duplication being detected. Perhaps we
+ should use dev+ino pairs instead of names? */
+ const char *cdpath = tar_getcdpath (cdidx);
+ size_t copylen;
+ bool need_separator;
+
+ if (!cdpath)
+ call_arg_fatal ("getcwd", ".");
+ copylen = strlen (cdpath);
+ need_separator = ! (DOUBLE_SLASH_IS_DISTINCT_ROOT
+ && copylen == 2 && ISSLASH (cdpath[1]));
+ copy = xmalloc (copylen + need_separator + strlen (name) + 1);
+ strcpy (copy, cdpath);
+ copy[copylen] = DIRECTORY_SEPARATOR;
+ strcpy (copy + copylen + need_separator, name);
}
- if (! copy)
+ if (!copy)
copy = xstrdup (name);
normalize_filename_x (copy);
return copy;
@@ -326,6 +332,76 @@ replace_prefix (char **pname, const char *samp, size_t slen,
/* Handling numbers. */
+/* Convert VALUE, which is converted from a system integer type whose
+ minimum value is MINVAL and maximum MINVAL, to an decimal
+ integer string. Use the storage in BUF and return a pointer to the
+ converted string. If VALUE is converted from a negative integer in
+ the range MINVAL .. -1, represent it with a string representation
+ of the negative integer, using leading '-'. */
+#if ! (INTMAX_MAX <= UINTMAX_MAX / 2)
+# error "sysinttostr: uintmax_t cannot represent all intmax_t values"
+#endif
+char *
+sysinttostr (uintmax_t value, intmax_t minval, uintmax_t maxval,
+ char buf[SYSINT_BUFSIZE])
+{
+ if (value <= maxval)
+ return umaxtostr (value, buf);
+ else
+ {
+ intmax_t i = value - minval;
+ return imaxtostr (i + minval, buf);
+ }
+}
+
+/* Convert a prefix of the string ARG to a system integer type whose
+ minimum value is MINVAL and maximum MAXVAL. If MINVAL is negative,
+ negative integers MINVAL .. -1 are assumed to be represented using
+ leading '-' in the usual way. If the represented value exceeds
+ INTMAX_MAX, return a negative integer V such that (uintmax_t) V
+ yields the represented value. If ARGLIM is nonnull, store into
+ *ARGLIM a pointer to the first character after the prefix.
+
+ This is the inverse of sysinttostr.
+
+ On a normal return, set errno = 0.
+ On conversion error, return 0 and set errno = EINVAL.
+ On overflow, return an extreme value and set errno = ERANGE. */
+#if ! (INTMAX_MAX <= UINTMAX_MAX)
+# error "strtosysint: nonnegative intmax_t does not fit in uintmax_t"
+#endif
+intmax_t
+strtosysint (char const *arg, char **arglim, intmax_t minval, uintmax_t maxval)
+{
+ errno = 0;
+ if (maxval <= INTMAX_MAX)
+ {
+ if (ISDIGIT (arg[*arg == '-']))
+ {
+ intmax_t i = strtoimax (arg, arglim, 10);
+ intmax_t imaxval = maxval;
+ if (minval <= i && i <= imaxval)
+ return i;
+ errno = ERANGE;
+ return i < minval ? minval : maxval;
+ }
+ }
+ else
+ {
+ if (ISDIGIT (*arg))
+ {
+ uintmax_t i = strtoumax (arg, arglim, 10);
+ if (i <= maxval)
+ return represent_uintmax (i);
+ errno = ERANGE;
+ return maxval;
+ }
+ }
+
+ errno = EINVAL;
+ return 0;
+}
+
/* Output fraction and trailing digits appropriate for a nanoseconds
count equal to NS, but don't output unnecessary '.' or trailing
zeros. */
@@ -382,6 +458,84 @@ code_timespec (struct timespec t, char sbuf[TIMESPEC_STRSIZE_BOUND])
code_ns_fraction (ns, sbuf + UINTMAX_STRSIZE_BOUND);
return np;
}
+
+struct timespec
+decode_timespec (char const *arg, char **arg_lim, bool parse_fraction)
+{
+ time_t s = TYPE_MINIMUM (time_t);
+ int ns = -1;
+ char const *p = arg;
+ bool negative = *arg == '-';
+ struct timespec r;
+
+ if (! ISDIGIT (arg[negative]))
+ errno = EINVAL;
+ else
+ {
+ errno = 0;
+
+ if (negative)
+ {
+ intmax_t i = strtoimax (arg, arg_lim, 10);
+ if (TYPE_SIGNED (time_t) ? TYPE_MINIMUM (time_t) <= i : 0 <= i)
+ s = i;
+ else
+ errno = ERANGE;
+ }
+ else
+ {
+ uintmax_t i = strtoumax (arg, arg_lim, 10);
+ if (i <= TYPE_MAXIMUM (time_t))
+ s = i;
+ else
+ errno = ERANGE;
+ }
+
+ p = *arg_lim;
+ ns = 0;
+
+ if (parse_fraction && *p == '.')
+ {
+ int digits = 0;
+ bool trailing_nonzero = false;
+
+ while (ISDIGIT (*++p))
+ if (digits < LOG10_BILLION)
+ digits++, ns = 10 * ns + (*p - '0');
+ else
+ trailing_nonzero |= *p != '0';
+
+ while (digits < LOG10_BILLION)
+ digits++, ns *= 10;
+
+ if (negative)
+ {
+ /* Convert "-1.10000000000001" to s == -2, ns == 89999999.
+ I.e., truncate time stamps towards minus infinity while
+ converting them to internal form. */
+ ns += trailing_nonzero;
+ if (ns != 0)
+ {
+ if (s == TYPE_MINIMUM (time_t))
+ ns = -1;
+ else
+ {
+ s--;
+ ns = BILLION - ns;
+ }
+ }
+ }
+ }
+
+ if (errno == ERANGE)
+ ns = -1;
+ }
+
+ *arg_lim = (char *) p;
+ r.tv_sec = s;
+ r.tv_nsec = ns;
+ return r;
+}
/* File handling. */
@@ -390,7 +544,7 @@ static char *before_backup_name;
static char *after_backup_name;
/* Return 1 if FILE_NAME is obviously "." or "/". */
-static bool
+bool
must_be_dot_or_slash (char const *file_name)
{
file_name += FILE_SYSTEM_PREFIX_LEN (file_name);
@@ -431,7 +585,7 @@ safer_rmdir (const char *file_name)
return -1;
}
- return rmdir (file_name);
+ return unlinkat (chdir_fd, file_name, AT_REMOVEDIR);
}
/* Remove FILE_NAME, returning 1 on success. If FILE_NAME is a directory,
@@ -451,7 +605,7 @@ remove_any_file (const char *file_name, enum remove_option option)
if (try_unlink_first)
{
- if (unlink (file_name) == 0)
+ if (unlinkat (chdir_fd, file_name, 0) == 0)
return 1;
/* POSIX 1003.1-2001 requires EPERM when attempting to unlink a
@@ -467,7 +621,7 @@ remove_any_file (const char *file_name, enum remove_option option)
switch (errno)
{
case ENOTDIR:
- return !try_unlink_first && unlink (file_name) == 0;
+ return !try_unlink_first && unlinkat (chdir_fd, file_name, 0) == 0;
case 0:
case EEXIST:
@@ -484,7 +638,7 @@ remove_any_file (const char *file_name, enum remove_option option)
case RECURSIVE_REMOVE_OPTION:
{
- char *directory = savedir (file_name);
+ char *directory = tar_savedir (file_name, 0);
char const *entry;
size_t entrylen;
@@ -544,7 +698,7 @@ maybe_backup_file (const char *file_name, bool this_is_the_archive)
if (this_is_the_archive && _remdev (file_name))
return true;
- if (stat (file_name, &file_stat))
+ if (deref_stat (file_name, &file_stat) != 0)
{
if (errno == ENOENT)
return true;
@@ -564,7 +718,8 @@ maybe_backup_file (const char *file_name, bool this_is_the_archive)
if (! after_backup_name)
xalloc_die ();
- if (rename (before_backup_name, after_backup_name) == 0)
+ if (renameat (chdir_fd, before_backup_name, chdir_fd, after_backup_name)
+ == 0)
{
if (verbose_option)
fprintf (stdlis, _("Renaming %s to %s\n"),
@@ -591,7 +746,8 @@ undo_last_backup (void)
{
if (after_backup_name)
{
- if (rename (after_backup_name, before_backup_name) != 0)
+ if (renameat (chdir_fd, after_backup_name, chdir_fd, before_backup_name)
+ != 0)
{
int e = errno;
ERROR ((0, e, _("%s: Cannot rename to %s"),
@@ -606,39 +762,75 @@ undo_last_backup (void)
}
}
-/* Depending on DEREF, apply either stat or lstat to (NAME, BUF). */
+/* Apply either stat or lstat to (NAME, BUF), depending on the
+ presence of the --dereference option. NAME is relative to the
+ most-recent argument to chdir_do. */
int
-deref_stat (bool deref, char const *name, struct stat *buf)
+deref_stat (char const *name, struct stat *buf)
{
- return deref ? stat (name, buf) : lstat (name, buf);
+ return fstatat (chdir_fd, name, buf, fstatat_flags);
}
-/* Use futimens if possible, utimensat otherwise. */
-int
-fd_utimensat (int fd, int parentfd, char const *file,
- struct timespec const ts[2], int atflag)
+/* Read from FD into the buffer BUF with COUNT bytes. Attempt to fill
+ BUF. Wait until input is available; this matters because files are
+ opened O_NONBLOCK for security reasons, and on some file systems
+ this can cause read to fail with errno == EAGAIN. Return the
+ actual number of bytes read, zero for EOF, or
+ SAFE_READ_ERROR upon error. */
+size_t
+blocking_read (int fd, void *buf, size_t count)
{
- if (0 <= fd)
+ size_t bytes = safe_read (fd, buf, count);
+
+#if defined F_SETFL && O_NONBLOCK
+ if (bytes == SAFE_READ_ERROR && errno == EAGAIN)
{
- int result = futimens (fd, ts);
- if (! (result < 0 && errno == ENOSYS))
- return result;
+ int flags = fcntl (fd, F_GETFL);
+ if (0 <= flags && flags & O_NONBLOCK
+ && fcntl (fd, F_SETFL, flags & ~O_NONBLOCK) != -1)
+ bytes = safe_read (fd, buf, count);
}
+#endif
- return utimensat (parentfd, file, ts, atflag);
+ return bytes;
+}
+
+/* Write to FD from the buffer BUF with COUNT bytes. Do a full write.
+ Wait until an output buffer is available; this matters because
+ files are opened O_NONBLOCK for security reasons, and on some file
+ systems this can cause write to fail with errno == EAGAIN. Return
+ the actual number of bytes written, setting errno if that is less
+ than COUNT. */
+size_t
+blocking_write (int fd, void const *buf, size_t count)
+{
+ size_t bytes = full_write (fd, buf, count);
+
+#if defined F_SETFL && O_NONBLOCK
+ if (bytes < count && errno == EAGAIN)
+ {
+ int flags = fcntl (fd, F_GETFL);
+ if (0 <= flags && flags & O_NONBLOCK
+ && fcntl (fd, F_SETFL, flags & ~O_NONBLOCK) != -1)
+ {
+ char const *buffer = buf;
+ bytes += full_write (fd, buffer + bytes, count - bytes);
+ }
+ }
+#endif
+
+ return bytes;
}
/* Set FD's (i.e., assuming the working directory is PARENTFD, FILE's)
- access time to ATIME. ATFLAG controls symbolic-link following, in
- the style of openat. */
+ access time to ATIME. */
int
-set_file_atime (int fd, int parentfd, char const *file, struct timespec atime,
- int atflag)
+set_file_atime (int fd, int parentfd, char const *file, struct timespec atime)
{
struct timespec ts[2];
ts[0] = atime;
ts[1].tv_nsec = UTIME_OMIT;
- return fd_utimensat (fd, parentfd, file, ts, atflag);
+ return fdutimensat (fd, parentfd, file, ts, fstatat_flags);
}
/* A description of a working directory. */
@@ -646,14 +838,15 @@ struct wd
{
/* The directory's name. */
char const *name;
-
- /* A negative value if no attempt has been made to save the
- directory, 0 if it was saved successfully, and a positive errno
- value if it was not saved successfully. */
- int err;
-
- /* The saved version of the directory, if ERR == 0. */
- struct saved_cwd saved_cwd;
+ /* "Absolute" path representing this directory; in the contrast to
+ the real absolute pathname, it can contain /../ components (see
+ normalize_filename_x for the reason of it). It is NULL if the
+ absolute path could not be determined. */
+ char *abspath;
+ /* If nonzero, the file descriptor of the directory, or AT_FDCWD if
+ the working directory. If zero, the directory needs to be opened
+ to be used. */
+ int fd;
};
/* A vector of chdir targets. wd[0] is the initial working directory. */
@@ -665,8 +858,21 @@ static size_t wd_count;
/* The allocated size of the vector. */
static size_t wd_alloc;
+/* The maximum number of chdir targets with open directories.
+ Don't make it too large, as many operating systems have a small
+ limit on the number of open file descriptors. Also, the current
+ implementation does not scale well. */
+enum { CHDIR_CACHE_SIZE = 16 };
+
+/* Indexes into WD of chdir targets with open file descriptors, sorted
+ most-recently used first. Zero indexes are unused. */
+static int wdcache[CHDIR_CACHE_SIZE];
+
+/* Number of nonzero entries in WDCACHE. */
+static size_t wdcache_count;
+
int
-chdir_count ()
+chdir_count (void)
{
if (wd_count == 0)
return wd_count;
@@ -678,20 +884,19 @@ chdir_count ()
int
chdir_arg (char const *dir)
{
+ char *absdir;
+
if (wd_count == wd_alloc)
{
if (wd_alloc == 0)
- {
- wd_alloc = 2;
- wd = xmalloc (sizeof *wd * wd_alloc);
- }
- else
- wd = x2nrealloc (wd, &wd_alloc, sizeof *wd);
+ wd_alloc = 2;
+ wd = x2nrealloc (wd, &wd_alloc, sizeof *wd);
if (! wd_count)
{
wd[wd_count].name = ".";
- wd[wd_count].err = -1;
+ wd[wd_count].abspath = xgetcwd ();
+ wd[wd_count].fd = AT_FDCWD;
wd_count++;
}
}
@@ -707,70 +912,121 @@ chdir_arg (char const *dir)
return wd_count - 1;
}
+
+ /* If the given name is absolute, use it to represent this directory;
+ otherwise, construct a name based on the previous -C option. */
+ if (IS_ABSOLUTE_FILE_NAME (dir))
+ absdir = xstrdup (dir);
+ else if (wd[wd_count - 1].abspath)
+ {
+ namebuf_t nbuf = namebuf_create (wd[wd_count - 1].abspath);
+ namebuf_add_dir (nbuf, dir);
+ absdir = namebuf_finish (nbuf);
+ }
+ else
+ absdir = 0;
+
wd[wd_count].name = dir;
- wd[wd_count].err = -1;
+ wd[wd_count].abspath = absdir;
+ wd[wd_count].fd = 0;
return wd_count++;
}
/* Index of current directory. */
int chdir_current;
-/* Change to directory I. If I is 0, change to the initial working
- directory; otherwise, I must be a value returned by chdir_arg. */
+/* Value suitable for use as the first argument to openat, and in
+ similar locations for fstatat, etc. This is an open file
+ descriptor, or AT_FDCWD if the working directory is current. It is
+ valid until the next invocation of chdir_do. */
+int chdir_fd = AT_FDCWD;
+
+/* Change to directory I, in a virtual way. This does not actually
+ invoke chdir; it merely sets chdir_fd to an int suitable as the
+ first argument for openat, etc. If I is 0, change to the initial
+ working directory; otherwise, I must be a value returned by
+ chdir_arg. */
void
chdir_do (int i)
{
if (chdir_current != i)
{
- struct wd *prev = &wd[chdir_current];
struct wd *curr = &wd[i];
+ int fd = curr->fd;
- if (prev->err < 0)
+ if (! fd)
{
- prev->err = 0;
- if (save_cwd (&prev->saved_cwd) != 0)
- prev->err = errno;
- else if (0 <= prev->saved_cwd.desc)
+ if (! IS_ABSOLUTE_FILE_NAME (curr->name))
+ chdir_do (i - 1);
+ fd = openat (chdir_fd, curr->name,
+ open_searchdir_flags & ~ O_NOFOLLOW);
+ if (fd < 0)
+ open_fatal (curr->name);
+
+ curr->fd = fd;
+
+ /* Add I to the cache, tossing out the lowest-ranking entry if the
+ cache is full. */
+ if (wdcache_count < CHDIR_CACHE_SIZE)
+ wdcache[wdcache_count++] = i;
+ else
{
- /* Make sure we still have at least one descriptor available. */
- int fd1 = prev->saved_cwd.desc;
- int fd2 = dup (fd1);
- if (0 <= fd2)
- close (fd2);
- else if (errno == EMFILE)
- {
- /* Force restore_cwd to use chdir_long. */
- close (fd1);
- prev->saved_cwd.desc = -1;
- prev->saved_cwd.name = xgetcwd ();
- if (! prev->saved_cwd.name)
- prev->err = errno;
- }
- else
- prev->err = errno;
+ struct wd *stale = &wd[wdcache[CHDIR_CACHE_SIZE - 1]];
+ if (close (stale->fd) != 0)
+ close_diag (stale->name);
+ stale->fd = 0;
+ wdcache[CHDIR_CACHE_SIZE - 1] = i;
}
}
- if (0 <= curr->err)
+ if (0 < fd)
{
- int err = curr->err;
- if (err == 0 && restore_cwd (&curr->saved_cwd) != 0)
- err = errno;
- if (err)
- FATAL_ERROR ((0, err, _("Cannot restore working directory")));
- }
- else
- {
- if (i && ! ISSLASH (curr->name[0]))
- chdir_do (i - 1);
- if (chdir (curr->name) != 0)
- chdir_fatal (curr->name);
+ /* Move the i value to the front of the cache. This is
+ O(CHDIR_CACHE_SIZE), but the cache is small. */
+ size_t ci;
+ int prev = wdcache[0];
+ for (ci = 1; prev != i; ci++)
+ {
+ int cur = wdcache[ci];
+ wdcache[ci] = prev;
+ if (cur == i)
+ break;
+ prev = cur;
+ }
+ wdcache[0] = i;
}
chdir_current = i;
+ chdir_fd = fd;
}
}
+const char *
+tar_dirname (void)
+{
+ return wd[chdir_current].name;
+}
+
+/* Return the absolute path that represents the working
+ directory referenced by IDX.
+
+ If wd is empty, then there were no -C options given, and
+ chdir_args() has never been called, so we simply return the
+ process's actual cwd. (Note that in this case IDX is ignored,
+ since it should always be 0.) */
+static const char *
+tar_getcdpath (int idx)
+{
+ if (!wd)
+ {
+ static char *cwd;
+ if (!cwd)
+ cwd = xgetcwd ();
+ return cwd;
+ }
+ return wd[idx].abspath;
+}
+
void
close_diag (char const *name)
{
@@ -849,21 +1105,6 @@ file_removed_diag (const char *name, bool top_level,
diagfn (name);
}
-void
-dir_removed_diag (const char *name, bool top_level,
- void (*diagfn) (char const *name))
-{
- if (!top_level && errno == ENOENT)
- {
- WARNOPT (WARN_FILE_REMOVED,
- (0, 0, _("%s: Directory removed before we read it"),
- quotearg_colon (name)));
- set_exit_status (TAREXIT_DIFFERS);
- }
- else
- diagfn (name);
-}
-
void
write_fatal_details (char const *name, ssize_t status, size_t size)
{
@@ -920,7 +1161,7 @@ page_aligned_alloc (void **ptr, size_t size)
struct namebuf
{
- char *buffer; /* directory, `/', and directory member */
+ char *buffer; /* directory, '/', and directory member */
size_t buffer_size; /* allocated size of name_buffer */
size_t dir_length; /* length of directory part in buffer */
};
@@ -954,3 +1195,55 @@ namebuf_name (namebuf_t buf, const char *name)
strcpy (buf->buffer + buf->dir_length, name);
return buf->buffer;
}
+
+void
+namebuf_add_dir (namebuf_t buf, const char *name)
+{
+ static char dirsep[] = { DIRECTORY_SEPARATOR, 0 };
+ if (!ISSLASH (buf->buffer[buf->dir_length - 1]))
+ {
+ namebuf_name (buf, dirsep);
+ buf->dir_length++;
+ }
+ namebuf_name (buf, name);
+ buf->dir_length += strlen (name);
+}
+
+char *
+namebuf_finish (namebuf_t buf)
+{
+ char *res = buf->buffer;
+
+ if (ISSLASH (buf->buffer[buf->dir_length - 1]))
+ buf->buffer[buf->dir_length] = 0;
+ free (buf);
+ return res;
+}
+
+/* Return the filenames in directory NAME, relative to the chdir_fd.
+ If the directory does not exist, report error if MUST_EXIST is
+ true.
+
+ Return NULL on errors.
+*/
+char *
+tar_savedir (const char *name, int must_exist)
+{
+ char *ret = NULL;
+ DIR *dir = NULL;
+ int fd = openat (chdir_fd, name, open_read_flags | O_DIRECTORY);
+ if (fd < 0)
+ {
+ if (!must_exist && errno == ENOENT)
+ return NULL;
+ open_error (name);
+ }
+ else if (! ((dir = fdopendir (fd))
+ && (ret = streamsavedir (dir))))
+ savedir_error (name);
+
+ if (dir ? closedir (dir) != 0 : 0 <= fd && close (fd) != 0)
+ savedir_error (name);
+
+ return ret;
+}