From bac7488e06e379628653fb2f3ece0a30414ff84e Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 22 Jan 2018 21:03:53 +0100
Subject: [PATCH] tmpfiles: change ownership of symlinks too

Ownership is supported for symlinks, too, only file modes are not.
Support that too.

Fixes: #7509
(cherry picked from commit 51207ca134716a0dee5fd763a6c39204be849eb1)

Resolves: #1620110
---
 src/shared/macro.h      |  7 +++++++
 src/tmpfiles/tmpfiles.c | 41 +++++++++++++++++++++--------------------
 2 files changed, 28 insertions(+), 20 deletions(-)

diff --git a/src/shared/macro.h b/src/shared/macro.h
index 7a57f4e5b1..26df270d51 100644
--- a/src/shared/macro.h
+++ b/src/shared/macro.h
@@ -125,6 +125,13 @@ static inline unsigned long ALIGN_POWER2(unsigned long u) {
 
 #define ELEMENTSOF(x) (sizeof(x)/sizeof((x)[0]))
 
+/*
+ * STRLEN - return the length of a string literal, minus the trailing NUL byte.
+ *          Contrary to strlen(), this is a constant expression.
+ * @x: a string literal.
+ */
+#define STRLEN(x) (sizeof(""x"") - 1)
+
 /*
  * container_of - cast a member of a structure out to the containing structure
  * @ptr: the pointer to the member.
diff --git a/src/tmpfiles/tmpfiles.c b/src/tmpfiles/tmpfiles.c
index 0b17b5908e..663f6c8b2d 100644
--- a/src/tmpfiles/tmpfiles.c
+++ b/src/tmpfiles/tmpfiles.c
@@ -591,6 +591,7 @@ finish:
 }
 
 static int path_set_perms(Item *i, const char *path) {
+        char fn[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
         _cleanup_close_ int fd = -1;
         struct stat st;
 
@@ -624,14 +625,12 @@ static int path_set_perms(Item *i, const char *path) {
         if (i->type == EMPTY_DIRECTORY && !S_ISDIR(st.st_mode))
                 return log_error_errno(EEXIST, "'%s' already exists and is not a directory. ", path);
 
-        if (S_ISLNK(st.st_mode))
-                log_debug("Skipping mode an owner fix for symlink %s.", path);
-        else {
-                char fn[strlen("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
-                xsprintf(fn, "/proc/self/fd/%i", fd);
+        xsprintf(fn, "/proc/self/fd/%i", fd);
 
-                /* not using i->path directly because it may be a glob */
-                if (i->mode_set) {
+        if (i->mode_set) {
+                if (S_ISLNK(st.st_mode))
+                        log_debug("Skipping mode fix for symlink %s.", path);
+                else {
                         mode_t m = i->mode;
 
                         if (i->mask_perms) {
@@ -646,25 +645,27 @@ static int path_set_perms(Item *i, const char *path) {
                         }
 
                         if (m == (st.st_mode & 07777))
-                                log_debug("\"%s\" has right mode %o", path, st.st_mode);
+                                log_debug("\"%s\" has correct mode %o already.", path, st.st_mode);
                         else {
-                                log_debug("chmod \"%s\" to mode %o", path, m);
+                                log_debug("Changing \"%s\" to mode %o.", path, m);
+
                                 if (chmod(fn, m) < 0)
                                         return log_error_errno(errno, "chmod(%s) failed: %m", path);
                         }
                 }
+        }
 
-                if ((i->uid != st.st_uid || i->gid != st.st_gid) &&
-                    (i->uid_set || i->gid_set)) {
-                        log_debug("chown \"%s\" to "UID_FMT"."GID_FMT,
-                                  path,
-                                  i->uid_set ? i->uid : UID_INVALID,
-                                  i->gid_set ? i->gid : GID_INVALID);
-                        if (chown(fn,
-                                  i->uid_set ? i->uid : UID_INVALID,
-                                  i->gid_set ? i->gid : GID_INVALID) < 0)
-                        return log_error_errno(errno, "chown(%s) failed: %m", path);
-                }
+        if ((i->uid != st.st_uid || i->gid != st.st_gid) &&
+            (i->uid_set || i->gid_set)) {
+                log_debug("Changing \"%s\" to owner "UID_FMT":"GID_FMT,
+                          path,
+                          i->uid_set ? i->uid : UID_INVALID,
+                          i->gid_set ? i->gid : GID_INVALID);
+
+                if (chown(fn,
+                          i->uid_set ? i->uid : UID_INVALID,
+                          i->gid_set ? i->gid : GID_INVALID) < 0)
+                        return log_error_errno(errno, "chown() of %s via %s failed: %m", path, fn);
         }
 
         fd = safe_close(fd);