*
*/
-/* Enables get_current_dir_name() in unistd.h and the O_PATH flag. */
+/* Enables get_current_dir_name() in unistd.h, the O_PATH flag, and
+ * the asprintf() function.
+*/
#define _GNU_SOURCE
#include <dirent.h> /* readdir(), etc. */
#include <errno.h> /* EINVAL, ELOOP, ENOTDIR, etc. */
#include <fcntl.h> /* openat() */
#include <libgen.h> /* basename(), dirname() */
-#include <limits.h> /* PATH_MAX */
#include <stdbool.h> /* the "bool" type */
-#include <stdio.h> /* perror(), snprintf() */
+#include <stdio.h> /* perror(), asprintf() */
#include <stdlib.h> /* free() */
#include <string.h> /* strdup() */
#include <sys/stat.h> /* fstat() */
*/
#define CLOSE_ERROR -1
#define OPEN_ERROR -1
-#define SNPRINTF_ERROR -1
+#define ASPRINTF_ERROR -1
#define STAT_ERROR -1
#define XATTR_ERROR -1
+/* Prototypes */
+int safe_open_ex(int at_fd, char* pathname, int flags);
+int safe_open(const char* pathname, int flags);
+int acl_update_entry(acl_t aclp, acl_entry_t entry);
+int acl_entry_count(acl_t acl);
+int acl_is_minimal(acl_t acl);
+int acl_execute_masked(acl_t acl);
+int any_can_execute(int fd, const struct stat* sp);
+int acl_copy_xattr(int src_fd,
+ acl_type_t src_type,
+ int dst_fd,
+ acl_type_t dst_type);
+int has_default_acl_fd(int fd);
+int apply_default_acl_fds(int parent_fd, int fd, bool recursive);
+int apply_default_acl(const char* path, bool recursive);
+
+
+
/**
* @brief The recursive portion of the @c safe_open function, used to
* open a file descriptor in a symlink-safe way when combined with
return OPEN_ERROR;
}
- char abspath[PATH_MAX];
- int snprintf_result = 0;
+ char* abspath = NULL;
+ int asprintf_result = 0;
if (strchr(pathname, '/') == pathname) {
/* pathname is already absolute; just copy it. */
- snprintf_result = snprintf(abspath, PATH_MAX, "%s", pathname);
+ asprintf_result = asprintf(&abspath, "%s", pathname);
}
else {
/* Concatenate the current working directory and pathname into an
free(cwd);
return OPEN_ERROR;
}
- snprintf_result = snprintf(abspath, PATH_MAX, "%s/%s", abs_cwd, pathname);
+ asprintf_result = asprintf(&abspath, "%s/%s", abs_cwd, pathname);
free(cwd);
}
- if (snprintf_result == SNPRINTF_ERROR || snprintf_result > PATH_MAX) {
- perror("safe_open (snprintf)");
+ if (asprintf_result == ASPRINTF_ERROR) {
+ perror("safe_open (asprintf)");
return OPEN_ERROR;
}
+ /* Beyond here, asprintf() worked, and we need to free abspath. */
+ int result = OPEN_ERROR;
+
bool abspath_is_root = (strcmp(abspath, "/") == 0);
int rootflags = flags | O_DIRECTORY;
if (!abspath_is_root) {
int rootfd = open("/", rootflags);
if (rootfd == OPEN_ERROR) {
perror("safe_open (open)");
- return OPEN_ERROR;
+ result = OPEN_ERROR;
+ goto cleanup;
}
if (abspath_is_root) {
- return rootfd;
+ result = rootfd;
+ goto cleanup;
}
- int result = safe_open_ex(rootfd, abspath+1, flags);
+ result = safe_open_ex(rootfd, abspath+1, flags);
if (close(rootfd) == CLOSE_ERROR) {
perror("safe_open (close)");
- return OPEN_ERROR;
+ result = OPEN_ERROR;
+ goto cleanup;
}
+
+ cleanup:
+ free(abspath);
return result;
}
return ACL_ERROR;
}
char* src_acl_p = alloca(src_size_guess);
- /* The actual size may be smaller than our guess? I don't know. */
- ssize_t src_size = fgetxattr(src_fd, src_name, src_acl_p, src_size_guess);
+ /* The actual size may be smaller than our guess? I don't know. The
+ return value from fgetxattr() will either be nonnegative, or
+ XATTR_ERROR (which we've already ruled out), so it's safe to cast
+ it to an unsigned size_t here to avoid a compiler warning. */
+ ssize_t src_size = fgetxattr(src_fd,
+ src_name,
+ src_acl_p,
+ (size_t)src_size_guess);
if (src_size == XATTR_ERROR) {
if (errno == ENODATA) {
/* A missing ACL isn't an error. */
return ACL_ERROR;
}
- if (fsetxattr(dst_fd, dst_name, src_acl_p, src_size, 0) == XATTR_ERROR) {
+ /* See above: src_size must be nonnegative at this point,so we cast
+ it to size_t to avoid a compiler warning. */
+ if (fsetxattr(dst_fd,
+ dst_name,
+ src_acl_p,
+ (size_t)src_size,
+ 0)
+ == XATTR_ERROR) {
perror("acl_copy_xattr (fsetxattr)");
return ACL_ERROR;
}
* @param fd
* The file descriptor that should inherit its parent's default ACL.
*
- * @param no_exec_mask
- * The value (either true or false) of the --no-exec-mask flag.
- *
* @param recursive
* Should we recurse into subdirectories?
*
* - @c ACL_FAILURE - If symlinks or hard links are encountered.
* - @c ACL_ERROR - Unexpected library error.
*/
-int apply_default_acl_fds(int parent_fd,
- int fd,
- bool no_exec_mask,
- bool recursive) {
+int apply_default_acl_fds(int parent_fd, int fd, bool recursive) {
int result = ACL_SUCCESS;
/* The new ACL for this path */
}
- /* Default to not masking the exec bit; i.e. applying the default
- ACL literally. If --no-exec-mask was not specified, then we try
- to "guess" whether or not to mask the exec bit. This behavior
- is modeled after the capital 'X' perms of setfacl. */
- bool allow_exec = true;
+ /* Next We try to guess whether or not to strip the execute bits.
+ * This behavior is modeled after the capital 'X' perms of setfacl.
+ */
+ int ace_result = any_can_execute(fd, &s);
- if (!no_exec_mask) {
- /* Never mask the execute bit on directories. */
- int ace_result = any_can_execute(fd,&s) || S_ISDIR(s.st_mode);
+ if (ace_result == ACL_ERROR) {
+ perror("apply_default_acl_fds (any_can_execute)");
+ result = ACL_ERROR;
+ goto cleanup;
+ }
- if (ace_result == ACL_ERROR) {
- perror("apply_default_acl_fds (any_can_execute)");
- result = ACL_ERROR;
- goto cleanup;
- }
+ /* Never mask the execute bit on directories. */
+ bool allow_exec = (bool)ace_result || S_ISDIR(s.st_mode);
- allow_exec = (bool)ace_result;
- }
/* If it's a directory, inherit the parent's default. */
if (S_ISDIR(s.st_mode)) {
goto cleanup;
}
+ /* To mimic what the kernel does, I think we could drop
+ ACL_GROUP_OBJ from the list below? */
if (tag == ACL_MASK ||
tag == ACL_USER_OBJ ||
tag == ACL_GROUP_OBJ ||
continue;
}
}
- switch (apply_default_acl_fds(fd, new_fd, no_exec_mask, recursive)) {
+ switch (apply_default_acl_fds(fd, new_fd, recursive)) {
/* Don't overwrite an error result with success/failure. */
case ACL_FAILURE:
if (result == ACL_SUCCESS) {
* @param path
* The path whose ACL we would like to reset to its default.
*
- * @param no_exec_mask
- * The value (either true or false) of the --no-exec-mask flag.
- *
* @param recursive
* Should we recurse into subdirectories?
*
* - @c ACL_FAILURE - If symlinks or hard links are encountered.
* - @c ACL_ERROR - Unexpected library error.
*/
-int apply_default_acl(const char* path, bool no_exec_mask, bool recursive) {
+int apply_default_acl(const char* path, bool recursive) {
if (path == NULL) {
errno = EINVAL;
basename_path_copy = strdup(path);
if (basename_path_copy == NULL) {
perror("apply_default_acl (strdup)");
- return ACL_ERROR;
+ result = ACL_ERROR;
+ goto cleanup;
}
fd = openat(parent_fd, basename(basename_path_copy), O_NOFOLLOW);
if (fd == OPEN_ERROR) {
}
}
- result = apply_default_acl_fds(parent_fd, fd, no_exec_mask, recursive);
+ result = apply_default_acl_fds(parent_fd, fd, recursive);
cleanup:
free(dirname_path_copy);