systemctl: refuse to edit runtime dropins when they already exist in /etc

[elogind.git] / src / shared / path-util.c

diff --git a/src/shared/path-util.c b/src/shared/path-util.c
index 2f38c1096b642d1b15cb741016401221066951be..dcc8321f505ee685727ae8b3a7f3565eb6795b2d 100644 (file)
--- a/src/shared/path-util.c
+++ b/src/shared/path-util.c
@@ -129,13 +129,12 @@ char *path_make_absolute_cwd(const char *p) {
         if (!cwd)
                 return NULL;
 
-        return path_make_absolute(p, cwd);
+        return strjoin(cwd, "/", p, NULL);
 }
 
 int path_make_relative(const char *from_dir, const char *to_path, char **_r) {
         char *r, *p;
         unsigned n_parents;
-        size_t to_path_len;
 
         assert(from_dir);
         assert(to_path);
@@ -168,6 +167,8 @@ int path_make_relative(const char *from_dir, const char *to_path, char **_r) {
                         if (!r)
                                 return -ENOMEM;
 
+                        path_kill_slashes(r);
+
                         *_r = r;
                         return 0;
                 }
@@ -202,21 +203,15 @@ int path_make_relative(const char *from_dir, const char *to_path, char **_r) {
                 n_parents++;
         }
 
-        to_path_len = strlen(to_path);
-
-        r = malloc(n_parents * 3 + to_path_len);
+        r = malloc(n_parents * 3 + strlen(to_path) + 1);
         if (!r)
                 return -ENOMEM;
 
         for (p = r; n_parents > 0; n_parents--, p += 3)
                 memcpy(p, "../", 3);
 
-        if (to_path_len > 0)
-                memcpy(p, to_path, to_path_len);
-        else
-                /* "to_path" is a parent directory of "from_dir". Let's remove
-                 * the redundant slash from the end of the result. */
-                *(p - 1) = 0;
+        strcpy(p, to_path);
+        path_kill_slashes(r);
 
         *_r = r;
         return 0;
@@ -243,7 +238,7 @@ char **path_strv_make_absolute_cwd(char **l) {
         return l;
 }
 
-char **path_strv_canonicalize_absolute(char **l, const char *prefix) {
+char **path_strv_resolve(char **l, const char *prefix) {
         char **s;
         unsigned k = 0;
         bool enomem = false;
@@ -328,12 +323,12 @@ char **path_strv_canonicalize_absolute(char **l, const char *prefix) {
         return l;
 }
 
-char **path_strv_canonicalize_absolute_uniq(char **l, const char *prefix) {
+char **path_strv_resolve_uniq(char **l, const char *prefix) {
 
         if (strv_isempty(l))
                 return l;
 
-        if (!path_strv_canonicalize_absolute(l, prefix))
+        if (!path_strv_resolve(l, prefix))
                 return NULL;
 
         return strv_uniq(l);
@@ -440,6 +435,22 @@ bool path_equal(const char *a, const char *b) {
         }
 }
 
+char* path_join(const char *root, const char *path, const char *rest) {
+        assert(path);
+
+        if (!isempty(root))
+                return strjoin(root, endswith(root, "/") ? "" : "/",
+                               path[0] == '/' ? path+1 : path,
+                               rest ? (endswith(path, "/") ? "" : "/") : NULL,
+                               rest && rest[0] == '/' ? rest+1 : rest,
+                               NULL);
+        else
+                return strjoin(path,
+                               rest ? (endswith(path, "/") ? "" : "/") : NULL,
+                               rest && rest[0] == '/' ? rest+1 : rest,
+                               NULL);
+}
+
 int path_is_mount_point(const char *t, bool allow_symlink) {
 
         union file_handle_union h = {
@@ -447,7 +458,7 @@ int path_is_mount_point(const char *t, bool allow_symlink) {
         };
 
         int mount_id, mount_id_parent;
-        char *parent;
+        _cleanup_free_ char *parent = NULL;
         struct stat a, b;
         int r;
 
@@ -478,7 +489,6 @@ int path_is_mount_point(const char *t, bool allow_symlink) {
 
         h.handle.handle_bytes = MAX_HANDLE_SZ;
         r = name_to_handle_at(AT_FDCWD, parent, &h.handle, &mount_id_parent, 0);
-        free(parent);
         if (r < 0) {
                 /* The parent can't do name_to_handle_at() but the
                  * directory we are interested in can? If so, it must
@@ -509,7 +519,6 @@ fallback:
                 return r;
 
         r = lstat(parent, &b);
-        free(parent);
         if (r < 0)
                 return -errno;
 
@@ -524,26 +533,41 @@ int path_is_read_only_fs(const char *path) {
         if (statvfs(path, &st) < 0)
                 return -errno;
 
-        return !!(st.f_flag & ST_RDONLY);
+        if (st.f_flag & ST_RDONLY)
+                return true;
+
+        /* On NFS, statvfs() might not reflect whether we can actually
+         * write to the remote share. Let's try again with
+         * access(W_OK) which is more reliable, at least sometimes. */
+        if (access(path, W_OK) < 0 && errno == EROFS)
+                return true;
+
+        return false;
 }
 
 int path_is_os_tree(const char *path) {
         char *p;
         int r;
 
-        /* We use /etc/os-release as flag file if something is an OS */
+        /* We use /usr/lib/os-release as flag file if something is an OS */
+        p = strappenda(path, "/usr/lib/os-release");
+        r = access(p, F_OK);
+
+        if (r >= 0)
+                return 1;
 
+        /* Also check for the old location in /etc, just in case. */
         p = strappenda(path, "/etc/os-release");
         r = access(p, F_OK);
 
-        return r < 0 ? 0 : 1;
+        return r >= 0;
 }
 
-int find_binary(const char *name, char **filename) {
+int find_binary(const char *name, bool local, char **filename) {
         assert(name);
 
-        if (strchr(name, '/')) {
-                if (access(name, X_OK) < 0)
+        if (is_path(name)) {
+                if (local && access(name, X_OK) < 0)
                         return -errno;
 
                 if (filename) {
@@ -559,7 +583,7 @@ int find_binary(const char *name, char **filename) {
                 return 0;
         } else {
                 const char *path;
-                char *state, *w;
+                const char *word, *state;
                 size_t l;
 
                 /**
@@ -570,10 +594,10 @@ int find_binary(const char *name, char **filename) {
                 if (!path)
                         path = DEFAULT_PATH;
 
-                FOREACH_WORD_SEPARATOR(w, l, path, ":", state) {
+                FOREACH_WORD_SEPARATOR(word, l, path, ":", state) {
                         _cleanup_free_ char *p = NULL;
 
-                        if (asprintf(&p, "%.*s/%s", (int) l, w, name) < 0)
+                        if (asprintf(&p, "%.*s/%s", (int) l, word, name) < 0)
                                 return -ENOMEM;
 
                         if (access(p, X_OK) < 0)
@@ -627,8 +651,25 @@ bool paths_check_timestamp(const char* const* paths, usec_t *timestamp, bool upd
 }
 
 int fsck_exists(const char *fstype) {
+        _cleanup_free_ char *p = NULL, *d = NULL;
         const char *checker;
+        int r;
 
         checker = strappenda("fsck.", fstype);
-        return find_binary(checker, NULL);
+
+        r = find_binary(checker, true, &p);
+        if (r < 0)
+                return r;
+
+        /* An fsck that is linked to /bin/true is a non-existent
+         * fsck */
+
+        r = readlink_malloc(p, &d);
+        if (r >= 0 &&
+            (path_equal(d, "/bin/true") ||
+             path_equal(d, "/usr/bin/true") ||
+             path_equal(d, "/dev/null")))
+                return -ENOENT;
+
+        return 0;
 }