journalctl,elsewhere: make sure --file=foo fails with sane error msg if foo is not readable

It annoyed me for quite a while that running "journalctl --file=…" on a
file that is not readable failed with a "File not found" error instead
of a permission error. Let's fix that.

We make this work by using the GLOB_NOCHECK flag for glob() which means
that files are not accessible will be returned in the array as they are
instead of being filtered away. This then means that our later attemps
to open the files will fail cleanly with a good error message.

src/basic/glob-util.c

@@ -61,11 +61,11 @@ int glob_exists(const char *path) {
         return true;
 }
 
-int glob_extend(char ***strv, const char *path) {
+int glob_extend(char ***strv, const char *path, int flags) {
         _cleanup_globfree_ glob_t g = {};
         int k;
 
-        k = safe_glob(path, GLOB_NOSORT|GLOB_BRACE, &g);
+        k = safe_glob(path, GLOB_NOSORT|GLOB_BRACE|flags, &g);
         if (k < 0)
                 return k;
 

src/basic/glob-util.h

@@ -11,7 +11,7 @@
 int safe_glob(const char *path, int flags, glob_t *pglob);
 
 int glob_exists(const char *path);
-int glob_extend(char ***strv, const char *path);
+int glob_extend(char ***strv, const char *path, int flags);
 
 #define _cleanup_globfree_ _cleanup_(globfree)
 

src/basic/path-util.c

@@ -1051,7 +1051,7 @@ int systemd_installation_has_version(const char *root, unsigned minimal_version)
                 if (!path)
                         return -ENOMEM;
 
-                r = glob_extend(&names, path);
+                r = glob_extend(&names, path, 0);
                 if (r == -ENOENT)
                         continue;
                 if (r < 0)

src/coredump/coredumpctl.c

@@ -237,7 +237,7 @@ static int parse_argv(int argc, char *argv[]) {
                         break;
 
                 case ARG_FILE:
-                        r = glob_extend(&arg_file, optarg);
+                        r = glob_extend(&arg_file, optarg, GLOB_NOCHECK);
                         if (r < 0)
                                 return log_error_errno(r, "Failed to add paths: %m");
                         break;

src/journal-remote/journal-upload.c

@@ -720,7 +720,7 @@ static int parse_argv(int argc, char *argv[]) {
                         break;
 
                 case ARG_FILE:
-                        r = glob_extend(&arg_file, optarg);
+                        r = glob_extend(&arg_file, optarg, GLOB_NOCHECK);
                         if (r < 0)
                                 return log_error_errno(r, "Failed to add paths: %m");
                         break;

src/journal/journalctl.c

@@ -705,7 +705,7 @@ static int parse_argv(int argc, char *argv[]) {
                                  * STDIN. To avoid confusion we hence don't document this feature. */
                                 arg_file_stdin = true;
                         else {
-                                r = glob_extend(&arg_file, optarg);
+                                r = glob_extend(&arg_file, optarg, GLOB_NOCHECK);
                                 if (r < 0)
                                         return log_error_errno(r, "Failed to add paths: %m");
                         }

src/sysctl/sysctl.c

@@ -138,7 +138,7 @@ static int apply_all(OrderedHashmap *sysctl_options) {
                         if (!pattern)
                                 return log_oom();
 
-                        k = glob_extend(&paths, pattern);
+                        k = glob_extend(&paths, pattern, GLOB_NOCHECK);
                         if (k < 0) {
                                 if (option->ignore_failure || ERRNO_IS_PRIVILEGE(k))
                                         log_debug_errno(k, "Failed to resolve glob '%s', ignoring: %m",