From: Mike Yuan <me@yhndnzj.com>
Date: Sat, 5 Apr 2025 20:29:33 +0000 (+0200)
Subject: path-util: generalize open_and_check_executable()
X-Git-Tag: v258-rc1~902^2~2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=326d60a9d0605f02936d0aa8ec5cf78cae72f5dd;p=thirdparty%2Fsystemd.git

path-util: generalize open_and_check_executable()
---

diff --git a/src/basic/path-util.c b/src/basic/path-util.c
index 78ba10ed809..dbde364effd 100644
--- a/src/basic/path-util.c
+++ b/src/basic/path-util.c
@@ -613,37 +613,9 @@ char* path_extend_internal(char **x, ...) {
         return nx;
 }
 
-static int check_x_access(const char *path, int *ret_fd) {
+int open_and_check_executable(const char *name, const char *root, char **ret_path, int *ret_fd) {
         _cleanup_close_ int fd = -EBADF;
-        int r;
-
-        /* We need to use O_PATH because there may be executables for which we have only exec
-         * permissions, but not read (usually suid executables). */
-        fd = open(path, O_PATH|O_CLOEXEC);
-        if (fd < 0)
-                return -errno;
-
-        r = fd_verify_regular(fd);
-        if (r < 0)
-                return r;
-
-        r = access_fd(fd, X_OK);
-        if (r == -ENOSYS) {
-                /* /proc is not mounted. Fallback to access(). */
-                if (access(path, X_OK) < 0)
-                        return -errno;
-        } else if (r < 0)
-                return r;
-
-        if (ret_fd)
-                *ret_fd = TAKE_FD(fd);
-
-        return 0;
-}
-
-static int find_executable_impl(const char *name, const char *root, char **ret_filename, int *ret_fd) {
-        _cleanup_close_ int fd = -EBADF;
-        _cleanup_free_ char *path_name = NULL;
+        _cleanup_free_ char *resolved = NULL;
         int r;
 
         assert(name);
@@ -654,23 +626,40 @@ static int find_executable_impl(const char *name, const char *root, char **ret_f
          * needed to avoid unforeseen regression or other complicated changes. */
         if (root) {
                 /* prefix root to name in case full paths are not specified */
-                r = chase(name, root, CHASE_PREFIX_ROOT, &path_name, /* ret_fd= */ NULL);
+                r = chase(name, root, CHASE_PREFIX_ROOT, &resolved, &fd);
                 if (r < 0)
                         return r;
 
-                name = path_name;
+                name = resolved;
+        } else {
+                /* We need to use O_PATH because there may be executables for which we have only exec permissions,
+                 * but not read (usually suid executables). */
+                fd = open(name, O_PATH|O_CLOEXEC);
+                if (fd < 0)
+                        return -errno;
         }
 
-        r = check_x_access(name, ret_fd ? &fd : NULL);
+        r = fd_verify_regular(fd);
         if (r < 0)
                 return r;
 
-        if (ret_filename) {
-                r = path_make_absolute_cwd(name, ret_filename);
-                if (r < 0)
-                        return r;
+        r = access_fd(fd, X_OK);
+        if (r == -ENOSYS)
+                /* /proc/ is not mounted. Fall back to access(). */
+                r = RET_NERRNO(access(name, X_OK));
+        if (r < 0)
+                return r;
 
-                path_simplify(*ret_filename);
+        if (ret_path) {
+                if (resolved)
+                        *ret_path = TAKE_PTR(resolved);
+                else {
+                        r = path_make_absolute_cwd(name, ret_path);
+                        if (r < 0)
+                                return r;
+
+                        path_simplify(*ret_path);
+                }
         }
 
         if (ret_fd)
@@ -692,7 +681,7 @@ int find_executable_full(
         assert(name);
 
         if (is_path(name))
-                return find_executable_impl(name, root, ret_filename, ret_fd);
+                return open_and_check_executable(name, root, ret_filename, ret_fd);
 
         if (exec_search_path) {
                 STRV_FOREACH(element, exec_search_path) {
@@ -707,7 +696,7 @@ int find_executable_full(
                         if (!full_path)
                                 return -ENOMEM;
 
-                        r = find_executable_impl(full_path, root, ret_filename, ret_fd);
+                        r = open_and_check_executable(full_path, root, ret_filename, ret_fd);
                         if (r >= 0)
                                 return 0;
                         if (r != -EACCES)
@@ -743,7 +732,7 @@ int find_executable_full(
                 if (!path_extend(&element, name))
                         return -ENOMEM;
 
-                r = find_executable_impl(element, root, ret_filename, ret_fd);
+                r = open_and_check_executable(element, root, ret_filename, ret_fd);
                 if (r >= 0) /* Found it! */
                         return 0;
                 /* PATH entries which we don't have access to are ignored, as per tradition. */
diff --git a/src/basic/path-util.h b/src/basic/path-util.h
index dff5a3a549c..436bd5d8927 100644
--- a/src/basic/path-util.h
+++ b/src/basic/path-util.h
@@ -115,6 +115,7 @@ int path_strv_make_absolute_cwd(char **l);
 char** path_strv_resolve(char **l, const char *root);
 char** path_strv_resolve_uniq(char **l, const char *root);
 
+int open_and_check_executable(const char *name, const char *root, char **ret_path, int *ret_fd);
 int find_executable_full(
                 const char *name,
                 const char *root,