+2009-09-02 Eric Blake <ebb9@byu.net>
+
+ fchdir: simplify error handling, and support dup3
+ * modules/fchdir (Depends-on): Use strdup-posix, not strdup. Add
+ stdbool, malloc-posix, realloc-posix.
+ * lib/fchdir.c (struct dir_info_t): Delete saved_errno.
+ (ensure_dirs_slot): Return false on allocation failure.
+ (rpl_dup2): Delete.
+ (_gl_register_dup): New function.
+ (_gl_unregister_fd, rpl_opendir, rpl_dup): Update callers.
+ (_gl_register_fd): Close fd on allocation failure.
+ * lib/fcntl.in.h (_gl_register_fd): Update signature.
+ * lib/unistd.in.h (_gl_register_dup) [FCHDIR_REPLACEMENT]: New
+ prototype.
+ (rpl_dup2_fchdir): Delete prototype.
+ * lib/open.c (open): Update caller.
+ * lib/dup2.c (dup2): Track fchdir metadata.
+ * lib/dup3.c (dup3): Likewise.
+ * m4/dup2.m4 (gl_REPLACE_DUP2): New macro.
+ * m4/fchdir.m4 (gl_FUNC_FCHDIR): Use it.
+
2009-09-02 Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
* gnulib-tool (func_create_testdir, func_create_megatestdir): Use
/* Specification. */
#include <unistd.h>
+#include <assert.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
-#include <stdarg.h>
+#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
object. */
/* Array of file descriptors opened. If it points to a directory, it stores
- info about this directory; otherwise it stores an errno value of ENOTDIR. */
+ info about this directory. */
typedef struct
{
char *name; /* Absolute name of the directory, or NULL. */
- int saved_errno; /* If name == NULL: The error code describing the failure
- reason. */
+ /* FIXME - add a DIR* member to make dirfd possible on mingw? */
} dir_info_t;
static dir_info_t *dirs;
static size_t dirs_allocated;
-/* Try to ensure dirs has enough room for a slot at index fd. */
-static void
+/* Try to ensure dirs has enough room for a slot at index fd. Return
+ false and set errno to ENOMEM on allocation failure. */
+static bool
ensure_dirs_slot (size_t fd)
{
if (fd >= dirs_allocated)
{
size_t new_allocated;
dir_info_t *new_dirs;
- size_t i;
new_allocated = 2 * dirs_allocated + 1;
if (new_allocated <= fd)
new_allocated = fd + 1;
new_dirs =
(dirs != NULL
- ? (dir_info_t *) realloc (dirs, new_allocated * sizeof (dir_info_t))
- : (dir_info_t *) malloc (new_allocated * sizeof (dir_info_t)));
- if (new_dirs != NULL)
- {
- for (i = dirs_allocated; i < new_allocated; i++)
- {
- new_dirs[i].name = NULL;
- new_dirs[i].saved_errno = ENOTDIR;
- }
- dirs = new_dirs;
- dirs_allocated = new_allocated;
- }
+ ? (dir_info_t *) realloc (dirs, new_allocated * sizeof *dirs)
+ : (dir_info_t *) malloc (new_allocated * sizeof *dirs));
+ if (new_dirs == NULL)
+ return false;
+ memset (new_dirs + dirs_allocated, 0,
+ (new_allocated - dirs_allocated) * sizeof *dirs);
+ dirs = new_dirs;
+ dirs_allocated = new_allocated;
}
+ return true;
}
/* Hook into the gnulib replacements for open() and close() to keep track
{
free (dirs[fd].name);
dirs[fd].name = NULL;
- dirs[fd].saved_errno = ENOTDIR;
}
}
-/* Mark FD as visiting FILENAME. FD must be positive, and refer to an
- open file descriptor. If REPLACE_OPEN_DIRECTORY is non-zero, this
- should only be called if FD is visiting a directory. */
-void
+/* Mark FD as visiting FILENAME. FD must be non-negative, and refer
+ to an open file descriptor. If REPLACE_OPEN_DIRECTORY is non-zero,
+ this should only be called if FD is visiting a directory. Close FD
+ and return -1 if there is insufficient memory to track the
+ directory name; otherwise return FD. */
+int
_gl_register_fd (int fd, const char *filename)
{
struct stat statbuf;
- ensure_dirs_slot (fd);
- if (fd < dirs_allocated
- && (REPLACE_OPEN_DIRECTORY
- || (fstat (fd, &statbuf) >= 0 && S_ISDIR (statbuf.st_mode))))
+ assert (0 <= fd);
+ if (REPLACE_OPEN_DIRECTORY
+ || (fstat (fd, &statbuf) == 0 && S_ISDIR (statbuf.st_mode)))
+ {
+ if (!ensure_dirs_slot (fd)
+ || (dirs[fd].name = canonicalize_file_name (filename)) == NULL)
+ {
+ int saved_errno = errno;
+ close (fd);
+ errno = saved_errno;
+ return -1;
+ }
+ }
+ return fd;
+}
+
+/* Mark NEWFD as a duplicate of OLDFD; useful from dup, dup2, dup3,
+ and fcntl. Both arguments must be valid and distinct file
+ descriptors. Close NEWFD and return -1 if OLDFD is tracking a
+ directory, but there is insufficient memory to track the same
+ directory in NEWFD; otherwise return NEWFD.
+
+ FIXME: Need to implement rpl_fcntl in gnulib, and have it call
+ this. */
+int
+_gl_register_dup (int oldfd, int newfd)
+{
+ assert (0 <= oldfd && 0 <= newfd && oldfd != newfd);
+ if (oldfd < dirs_allocated && dirs[oldfd].name)
{
- dirs[fd].name = canonicalize_file_name (filename);
- if (dirs[fd].name == NULL)
- dirs[fd].saved_errno = errno;
+ /* Duplicated a directory; must ensure newfd is allocated. */
+ if (!ensure_dirs_slot (newfd)
+ || (dirs[newfd].name = strdup (dirs[oldfd].name)) == NULL)
+ {
+ int saved_errno = errno;
+ close (newfd);
+ errno = saved_errno;
+ newfd = -1;
+ }
}
+ else if (newfd < dirs_allocated)
+ {
+ /* Duplicated a non-directory; ensure newfd is cleared. */
+ free (dirs[newfd].name);
+ dirs[newfd].name = NULL;
+ }
+ return newfd;
}
/* Return stat information about FD in STATBUF. Needed when
if (dp != NULL)
{
int fd = dirfd (dp);
- if (fd >= 0)
- _gl_register_fd (fd, filename);
+ if (0 <= fd && _gl_register_fd (fd, filename) != fd)
+ {
+ int saved_errno = errno;
+ closedir (dp);
+ errno = saved_errno;
+ return NULL;
+ }
}
return dp;
}
-/* Override dup() and dup2(), to keep track of open file descriptors. */
+/* Override dup(), to keep track of open file descriptors. */
int
rpl_dup (int oldfd)
{
int newfd = dup (oldfd);
- if (oldfd >= 0 && newfd >= 0)
- {
- ensure_dirs_slot (newfd);
- if (newfd < dirs_allocated)
- {
- if (oldfd < dirs_allocated)
- {
- if (dirs[oldfd].name != NULL)
- {
- dirs[newfd].name = strdup (dirs[oldfd].name);
- if (dirs[newfd].name == NULL)
- dirs[newfd].saved_errno = ENOMEM;
- }
- else
- {
- dirs[newfd].name = NULL;
- dirs[newfd].saved_errno = dirs[oldfd].saved_errno;
- }
- }
- else
- {
- dirs[newfd].name = NULL;
- dirs[newfd].saved_errno = ENOMEM;
- }
- }
- }
+ if (0 <= newfd)
+ newfd = _gl_register_dup (oldfd, newfd);
return newfd;
}
-/* Our <unistd.h> replacement overrides dup2 twice; be sure to pick
- the one we want. */
-#if REPLACE_DUP2
-# undef dup2
-# define dup2 rpl_dup2
-#endif
-
-int
-rpl_dup2_fchdir (int oldfd, int newfd)
-{
- int retval = dup2 (oldfd, newfd);
-
- if (retval >= 0 && newfd != oldfd)
- {
- ensure_dirs_slot (newfd);
- if (newfd < dirs_allocated)
- {
- if (oldfd < dirs_allocated)
- {
- if (dirs[oldfd].name != NULL)
- {
- dirs[newfd].name = strdup (dirs[oldfd].name);
- if (dirs[newfd].name == NULL)
- dirs[newfd].saved_errno = ENOMEM;
- }
- else
- {
- dirs[newfd].name = NULL;
- dirs[newfd].saved_errno = dirs[oldfd].saved_errno;
- }
- }
- else
- {
- dirs[newfd].name = NULL;
- dirs[newfd].saved_errno = ENOMEM;
- }
- }
- }
- return retval;
-}
/* Implement fchdir() in terms of chdir(). */
projects / gnulib.git / commitdiff