Merge pull request #29193 from keszybz/path-util-adjustment

Make unit mangling follow paths

src/basic/cgroup-util.c

@@ -978,6 +978,7 @@ int cg_is_empty_recursive(const char *controller, const char *path) {
 
 int cg_split_spec(const char *spec, char **ret_controller, char **ret_path) {
         _cleanup_free_ char *controller = NULL, *path = NULL;
+        int r;
 
         assert(spec);
 
@@ -986,11 +987,9 @@ int cg_split_spec(const char *spec, char **ret_controller, char **ret_path) {
                         return -EINVAL;
 
                 if (ret_path) {
-                        path = strdup(spec);
-                        if (!path)
-                                return -ENOMEM;
-
-                        path_simplify(path);
+                        r = path_simplify_alloc(spec, &path);
+                        if (r < 0)
+                                return r;
                 }
 
         } else {
@@ -1037,22 +1036,14 @@ int cg_split_spec(const char *spec, char **ret_controller, char **ret_path) {
 
 int cg_mangle_path(const char *path, char **result) {
         _cleanup_free_ char *c = NULL, *p = NULL;
-        char *t;
         int r;
 
         assert(path);
         assert(result);
 
         /* First, check if it already is a filesystem path */
-        if (path_startswith(path, "/sys/fs/cgroup")) {
-
-                t = strdup(path);
-                if (!t)
-                        return -ENOMEM;
-
-                *result = path_simplify(t);
-                return 0;
-        }
+        if (path_startswith(path, "/sys/fs/cgroup"))
+                return path_simplify_alloc(path, result);
 
         /* Otherwise, treat it as cg spec */
         r = cg_split_spec(path, &c, &p);

src/basic/fileio.c

@@ -1110,6 +1110,7 @@ int search_and_fopen(
                 char **ret_path) {
 
         _cleanup_strv_free_ char **copy = NULL;
+        int r;
 
         assert(filename);
         assert(mode);
@@ -1123,13 +1124,9 @@ int search_and_fopen(
                         return -errno;
 
                 if (ret_path) {
-                        char *p;
-
-                        p = strdup(filename);
-                        if (!p)
-                                return -ENOMEM;
-
-                        *ret_path = path_simplify(p);
+                        r = path_simplify_alloc(filename, ret_path);
+                        if (r < 0)
+                                return r;
                 }
 
                 *ret = TAKE_PTR(f);
@@ -1152,6 +1149,7 @@ int search_and_fopen_nulstr(
                 char **ret_path) {
 
         _cleanup_strv_free_ char **s = NULL;
+        int r;
 
         if (path_is_absolute(filename)) {
                 _cleanup_fclose_ FILE *f = NULL;
@@ -1161,13 +1159,9 @@ int search_and_fopen_nulstr(
                         return -errno;
 
                 if (ret_path) {
-                        char *p;
-
-                        p = strdup(filename);
-                        if (!p)
-                                return -ENOMEM;
-
-                        *ret_path = path_simplify(p);
+                        r = path_simplify_alloc(filename, ret_path);
+                        if (r < 0)
+                                return r;
                 }
 
                 *ret = TAKE_PTR(f);

src/basic/path-util.c

@@ -40,7 +40,7 @@ int path_split_and_make_absolute(const char *p, char ***ret) {
         return r;
 }
 
-char *path_make_absolute(const char *p, const char *prefix) {
+char* path_make_absolute(const char *p, const char *prefix) {
         assert(p);
 
         /* Makes every item in the list an absolute path by prepending
@@ -132,11 +132,9 @@ int path_make_relative(const char *from, const char *to, char **ret) {
                                         return -ENOMEM;
                         } else {
                                 /* 'to' is inside of 'from'. */
-                                result = strdup(t);
-                                if (!result)
-                                        return -ENOMEM;
-
-                                path_simplify(result);
+                                r = path_simplify_alloc(t, &result);
+                                if (r < 0)
+                                        return r;
 
                                 if (!path_is_valid(result))
                                         return -EINVAL;
@@ -252,7 +250,7 @@ int path_strv_make_absolute_cwd(char **l) {
         return 0;
 }
 
-char **path_strv_resolve(char **l, const char *root) {
+char** path_strv_resolve(char **l, const char *root) {
         unsigned k = 0;
         bool enomem = false;
         int r;
@@ -333,7 +331,7 @@ char **path_strv_resolve(char **l, const char *root) {
         return l;
 }
 
-char **path_strv_resolve_uniq(char **l, const char *root) {
+char** path_strv_resolve_uniq(char **l, const char *root) {
 
         if (strv_isempty(l))
                 return l;
@@ -344,9 +342,9 @@ char **path_strv_resolve_uniq(char **l, const char *root) {
         return strv_uniq(l);
 }
 
-char *path_simplify_full(char *path, PathSimplifyFlags flags) {
-        bool add_slash = false, keep_trailing_slash;
-        char *f = ASSERT_PTR(path);
+char* path_simplify_full(char *path, PathSimplifyFlags flags) {
+        bool add_slash = false, keep_trailing_slash, absolute, beginning = true;
+        char *f = path;
         int r;
 
         /* Removes redundant inner and trailing slashes. Also removes unnecessary dots.
@@ -354,6 +352,8 @@ char *path_simplify_full(char *path, PathSimplifyFlags flags) {
          *
          * ///foo//./bar/.   becomes /foo/bar
          * .//./foo//./bar/. becomes foo/bar
+         * /../foo/bar       becomes /foo/bar
+         * /../foo/bar/..    becomes /foo/bar/..
          */
 
         if (isempty(path))
@@ -361,8 +361,8 @@ char *path_simplify_full(char *path, PathSimplifyFlags flags) {
 
         keep_trailing_slash = FLAGS_SET(flags, PATH_SIMPLIFY_KEEP_TRAILING_SLASH) && endswith(path, "/");
 
-        if (path_is_absolute(path))
-                f++;
+        absolute = path_is_absolute(path);
+        f += absolute;  /* Keep leading /, if present. */
 
         for (const char *p = f;;) {
                 const char *e;
@@ -371,11 +371,17 @@ char *path_simplify_full(char *path, PathSimplifyFlags flags) {
                 if (r == 0)
                         break;
 
+                if (r > 0 && absolute && beginning && path_startswith(e, ".."))
+                        /* If we're at the beginning of an absolute path, we can safely skip ".." */
+                        continue;
+
+                beginning = false;
+
                 if (add_slash)
                         *f++ = '/';
 
                 if (r < 0) {
-                        /* if path is invalid, then refuse to simplify remaining part. */
+                        /* if path is invalid, then refuse to simplify the remaining part. */
                         memmove(f, p, strlen(p) + 1);
                         return path;
                 }
@@ -397,7 +403,7 @@ char *path_simplify_full(char *path, PathSimplifyFlags flags) {
         return path;
 }
 
-char *path_startswith_full(const char *path, const char *prefix, bool accept_dot_dot) {
+char* path_startswith_full(const char *path, const char *prefix, bool accept_dot_dot) {
         assert(path);
         assert(prefix);
 
@@ -657,7 +663,14 @@ static int find_executable_impl(const char *name, const char *root, char **ret_f
         return 0;
 }
 
-int find_executable_full(const char *name, const char *root, char **exec_search_path, bool use_path_envvar, char **ret_filename, int *ret_fd) {
+int find_executable_full(
+                const char *name,
+                const char *root,
+                char **exec_search_path,
+                bool use_path_envvar,
+                char **ret_filename,
+                int *ret_fd) {
+
         int last_error = -ENOENT, r = 0;
         const char *p = NULL;
 
@@ -807,7 +820,7 @@ int fsck_exists_for_fstype(const char *fstype) {
         return executable_is_good(checker);
 }
 
-static const char *skip_slash_or_dot(const char *p) {
+static const char* skip_slash_or_dot(const char *p) {
         for (; !isempty(p); p++) {
                 if (*p == '/')
                         continue;
@@ -891,7 +904,7 @@ int path_find_first_component(const char **p, bool accept_dot_dot, const char **
         return len;
 }
 
-static const char *skip_slash_or_dot_backward(const char *path, const char *q) {
+static const char* skip_slash_or_dot_backward(const char *path, const char *q) {
         assert(path);
         assert(!q || q >= path);
 
@@ -1000,7 +1013,7 @@ int path_find_last_component(const char *path, bool accept_dot_dot, const char *
         return len;
 }
 
-const char *last_path_component(const char *path) {
+const char* last_path_component(const char *path) {
 
         /* Finds the last component of the path, preserving the optional trailing slash that signifies a directory.
          *
@@ -1272,9 +1285,16 @@ bool hidden_or_backup_file(const char *filename) {
 bool is_device_path(const char *path) {
 
         /* Returns true for paths that likely refer to a device, either by path in sysfs or to something in
-         * /dev. */
+         * /dev. This accepts any path that starts with /dev/ or /sys/ and has something after that prefix.
+         * It does not actually resolve the path.
+         *
+         * Examples:
+         * /dev/sda, /dev/sda/foo, /sys/class, /dev/.., /sys/.., /./dev/foo → yes.
+         * /../dev/sda, /dev, /sys, /usr/path, /usr/../dev/sda → no.
+         */
 
-        return PATH_STARTSWITH_SET(path, "/dev/", "/sys/");
+        const char *p = PATH_STARTSWITH_SET(ASSERT_PTR(path), "/dev/", "/sys/");
+        return !isempty(p);
 }
 
 bool valid_device_node_path(const char *path) {

src/basic/path-util.h

@@ -53,7 +53,7 @@ int safe_getcwd(char **ret);
 int path_make_absolute_cwd(const char *p, char **ret);
 int path_make_relative(const char *from, const char *to, char **ret);
 int path_make_relative_parent(const char *from_child, const char *to, char **ret);
-char *path_startswith_full(const char *path, const char *prefix, bool accept_dot_dot) _pure_;
+char* path_startswith_full(const char *path, const char *prefix, bool accept_dot_dot) _pure_;
 static inline char* path_startswith(const char *path, const char *prefix) {
         return path_startswith_full(path, prefix, true);
 }
@@ -80,11 +80,27 @@ typedef enum PathSimplifyFlags {
         PATH_SIMPLIFY_KEEP_TRAILING_SLASH = 1 << 0,
 } PathSimplifyFlags;
 
-char *path_simplify_full(char *path, PathSimplifyFlags flags);
+char* path_simplify_full(char *path, PathSimplifyFlags flags);
 static inline char* path_simplify(char *path) {
         return path_simplify_full(path, 0);
 }
 
+static inline int path_simplify_alloc(const char *path, char **ret) {
+        assert(ret);
+
+        if (!path) {
+                *ret = NULL;
+                return 0;
+        }
+
+        char *t = strdup(path);
+        if (!t)
+                return -ENOMEM;
+
+        *ret = path_simplify(t);
+        return 0;
+}
+
 static inline bool path_equal_ptr(const char *a, const char *b) {
         return !!a == !!b && (!a || path_equal(a, b));
 }
@@ -159,7 +175,7 @@ int fsck_exists_for_fstype(const char *fstype);
 
 int path_find_first_component(const char **p, bool accept_dot_dot, const char **ret);
 int path_find_last_component(const char *path, bool accept_dot_dot, const char **next, const char **ret);
-const char *last_path_component(const char *path);
+const char* last_path_component(const char *path);
 int path_extract_filename(const char *path, char **ret);
 int path_extract_directory(const char *path, char **ret);
 
@@ -196,7 +212,7 @@ static inline const char *skip_dev_prefix(const char *p) {
 }
 
 bool empty_or_root(const char *path);
-static inline const char *empty_to_root(const char *path) {
+static inline const char* empty_to_root(const char *path) {
         return isempty(path) ? "/" : path;
 }
 

src/basic/unit-name.c

@@ -389,15 +389,14 @@ int unit_name_unescape(const char *f, char **ret) {
 int unit_name_path_escape(const char *f, char **ret) {
         _cleanup_free_ char *p = NULL;
         char *s;
+        int r;
 
         assert(f);
         assert(ret);
 
-        p = strdup(f);
-        if (!p)
-                return -ENOMEM;
-
-        path_simplify(p);
+        r = path_simplify_alloc(f, &p);
+        if (r < 0)
+                return r;
 
         if (empty_or_root(p))
                 s = strdup("-");
@@ -701,9 +700,15 @@ static bool do_escape_mangle(const char *f, bool allow_globs, char *t) {
  *
  *  If @allow_globs, globs characters are preserved. Otherwise, they are escaped.
  */
-int unit_name_mangle_with_suffix(const char *name, const char *operation, UnitNameMangle flags, const char *suffix, char **ret) {
+int unit_name_mangle_with_suffix(
+                const char *name,
+                const char *operation,
+                UnitNameMangle flags,
+                const char *suffix,
+                char **ret) {
+
         _cleanup_free_ char *s = NULL;
-        bool mangled, suggest_escape = true;
+        bool mangled, suggest_escape = true, warn = flags & UNIT_NAME_MANGLE_WARN;
         int r;
 
         assert(name);
@@ -724,22 +729,28 @@ int unit_name_mangle_with_suffix(const char *name, const char *operation, UnitNa
         if (string_is_glob(name) && in_charset(name, VALID_CHARS_GLOB)) {
                 if (flags & UNIT_NAME_MANGLE_GLOB)
                         goto good;
-                log_full(flags & UNIT_NAME_MANGLE_WARN ? LOG_NOTICE : LOG_DEBUG,
+                log_full(warn ? LOG_NOTICE : LOG_DEBUG,
                          "Glob pattern passed%s%s, but globs are not supported for this.",
                          operation ? " " : "", strempty(operation));
                 suggest_escape = false;
         }
 
-        if (is_device_path(name)) {
-                r = unit_name_from_path(name, ".device", ret);
-                if (r >= 0)
-                        return 1;
-                if (r != -EINVAL)
-                        return r;
-        }
-
         if (path_is_absolute(name)) {
-                r = unit_name_from_path(name, ".mount", ret);
+                _cleanup_free_ char *n = NULL;
+
+                r = path_simplify_alloc(name, &n);
+                if (r < 0)
+                        return r;
+
+                if (is_device_path(n)) {
+                        r = unit_name_from_path(n, ".device", ret);
+                        if (r >= 0)
+                                return 1;
+                        if (r != -EINVAL)
+                                return r;
+                }
+
+                r = unit_name_from_path(n, ".mount", ret);
                 if (r >= 0)
                         return 1;
                 if (r != -EINVAL)
@@ -752,7 +763,7 @@ int unit_name_mangle_with_suffix(const char *name, const char *operation, UnitNa
 
         mangled = do_escape_mangle(name, flags & UNIT_NAME_MANGLE_GLOB, s);
         if (mangled)
-                log_full(flags & UNIT_NAME_MANGLE_WARN ? LOG_NOTICE : LOG_DEBUG,
+                log_full(warn ? LOG_NOTICE : LOG_DEBUG,
                          "Invalid unit name \"%s\" escaped as \"%s\"%s.",
                          name, s,
                          suggest_escape ? " (maybe you should use systemd-escape?)" : "");

src/basic/user-util.c

@@ -589,7 +589,6 @@ int getgroups_alloc(gid_t** gids) {
 int get_home_dir(char **ret) {
         struct passwd *p;
         const char *e;
-        char *h;
         uid_t u;
 
         assert(ret);
@@ -622,18 +621,12 @@ int get_home_dir(char **ret) {
                 return -EINVAL;
 
  found:
-        h = strdup(e);
-        if (!h)
-                return -ENOMEM;
-
-        *ret = path_simplify(h);
-        return 0;
+        return path_simplify_alloc(e, ret);
 }
 
 int get_shell(char **ret) {
         struct passwd *p;
         const char *e;
-        char *s;
         uid_t u;
 
         assert(ret);
@@ -665,12 +658,7 @@ int get_shell(char **ret) {
                 return -EINVAL;
 
  found:
-        s = strdup(e);
-        if (!s)
-                return -ENOMEM;
-
-        *ret = path_simplify(s);
-        return 0;
+        return path_simplify_alloc(e, ret);
 }
 
 int reset_uid_gid(void) {