tree-wide: port various places over to use chmod_and_chown()

Doing this properly is hard, hence let's unify the code.

6 files changed, 31 insertions, 57 deletions

diff --git a/src/basic/fs-util.c b/src/basic/fs-util.c
index 5a3f8b827f..7dfc1b309d 100644
--- a/src/basic/fs-util.c
+++ b/src/basic/fs-util.c
@@ -359,13 +359,7 @@ int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gi
          * something fchown(), fchmod(), futimensat() don't allow. */
         xsprintf(fdpath, "/proc/self/fd/%i", fd);
 
-        if (mode != MODE_INVALID)
-                if (chmod(fdpath, mode) < 0)
-                        ret = -errno;
-
-        if (uid_is_valid(uid) || gid_is_valid(gid))
-                if (chown(fdpath, uid, gid) < 0 && ret >= 0)
-                        ret = -errno;
+        ret = fchmod_and_chown(fd, mode, uid, gid);
 
         if (stamp != USEC_INFINITY) {
                 struct timespec ts[2];
diff --git a/src/core/chown-recursive.c b/src/core/chown-recursive.c
index fb42865875..24cdf25b83 100644
--- a/src/core/chown-recursive.c
+++ b/src/core/chown-recursive.c
@@ -8,6 +8,7 @@
 #include "chown-recursive.h"
 #include "dirent-util.h"
 #include "fd-util.h"
+#include "fs-util.h"
 #include "macro.h"
 #include "stdio-util.h"
 #include "strv.h"
@@ -22,16 +23,13 @@ static int chown_one(
 
         char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
         const char *n;
+        int r;
 
         assert(fd >= 0);
         assert(st);
 
-        if ((!uid_is_valid(uid) || st->st_uid == uid) &&
-            (!gid_is_valid(gid) || st->st_gid == gid))
-                return 0;
-
-        /* We change ownership through the /proc/self/fd/%i path, so that we have a stable reference that works with
-         * O_PATH. (Note: fchown() and fchmod() do not work with O_PATH, the kernel refuses that. */
+        /* We change ACLs through the /proc/self/fd/%i path, so that we have a stable reference that works
+         * with O_PATH. */
         xsprintf(procfs_path, "/proc/self/fd/%i", fd);
 
         /* Drop any ACL if there is one */
@@ -40,16 +38,9 @@ static int chown_one(
                         if (!IN_SET(errno, ENODATA, EOPNOTSUPP, ENOSYS, ENOTTY))
                                 return -errno;
 
-        if (chown(procfs_path, uid, gid) < 0)
-                return -errno;
-
-        /* The linux kernel alters the mode in some cases of chown(), as well when we change ACLs. Let's undo this. We
-         * do this only for non-symlinks however. That's because for symlinks the access mode is ignored anyway and
-         * because on some kernels/file systems trying to change the access mode will succeed but has no effect while
-         * on others it actively fails. */
-        if (!S_ISLNK(st->st_mode))
-                if (chmod(procfs_path, st->st_mode & 07777 & mask) < 0)
-                        return -errno;
+        r = fchmod_and_chown(fd, st->st_mode & mask, uid, gid);
+        if (r < 0)
+                return r;
 
         return 1;
 }
diff --git a/src/core/execute.c b/src/core/execute.c
index e90c3ac4f3..ab2a4de37a 100644
--- a/src/core/execute.c
+++ b/src/core/execute.c
@@ -728,25 +728,24 @@ static int setup_output(
 }
 
 static int chown_terminal(int fd, uid_t uid) {
-        struct stat st;
+        int r;
 
         assert(fd >= 0);
 
         /* Before we chown/chmod the TTY, let's ensure this is actually a tty */
-        if (isatty(fd) < 1)
-                return 0;
+        if (isatty(fd) < 1) {
+                if (IN_SET(errno, EINVAL, ENOTTY))
+                        return 0; /* not a tty */
 
-        /* This might fail. What matters are the results. */
-        (void) fchown(fd, uid, -1);
-        (void) fchmod(fd, TTY_MODE);
-
-        if (fstat(fd, &st) < 0)
                 return -errno;
+        }
 
-        if (st.st_uid != uid || (st.st_mode & 0777) != TTY_MODE)
-                return -EPERM;
+        /* This might fail. What matters are the results. */
+        r = fchmod_and_chown(fd, TTY_MODE, uid, -1);
+        if (r < 0)
+                return r;
 
-        return 0;
+        return 1;
 }
 
 static int setup_confirm_stdio(const char *vc, int *_saved_stdin, int *_saved_stdout) {
diff --git a/src/random-seed/random-seed.c b/src/random-seed/random-seed.c
index 71c2dba431..510a2715f2 100644
--- a/src/random-seed/random-seed.c
+++ b/src/random-seed/random-seed.c
@@ -10,6 +10,7 @@
 
 #include "alloc-util.h"
 #include "fd-util.h"
+#include "fs-util.h"
 #include "io-util.h"
 #include "log.h"
 #include "main-func.h"
@@ -156,8 +157,7 @@ static int run(int argc, char *argv[]) {
                 /* This is just a safety measure. Given that we are root and
                  * most likely created the file ourselves the mode and owner
                  * should be correct anyway. */
-                (void) fchmod(seed_fd, 0600);
-                (void) fchown(seed_fd, 0, 0);
+                (void) fchmod_and_chown(seed_fd, 0600, 0, 0);
 
                 k = loop_read(random_fd, buf, buf_size, false);
                 if (k < 0)
diff --git a/src/udev/udev-node.c b/src/udev/udev-node.c
index cfbbd7b283..67d573cf2b 100644
--- a/src/udev/udev-node.c
+++ b/src/udev/udev-node.c
@@ -310,10 +310,10 @@ static int node_permissions_apply(sd_device *dev, bool apply,
 
                 if ((stats.st_mode & 0777) != (mode & 0777) || stats.st_uid != uid || stats.st_gid != gid) {
                         log_device_debug(dev, "Setting permissions %s, %#o, uid=%u, gid=%u", devnode, mode, uid, gid);
-                        if (chmod(devnode, mode) < 0)
-                                r = log_device_warning_errno(dev, errno, "Failed to set mode of %s to %#o: %m", devnode, mode);
-                        if (chown(devnode, uid, gid) < 0)
-                                r = log_device_warning_errno(dev, errno, "Failed to set owner of %s to uid=%u, gid=%u: %m", devnode, uid, gid);
+
+                        r = chmod_and_chown(devnode, mode, uid, gid);
+                        if (r < 0)
+                                log_device_warning_errno(dev, r, "Failed to set owner/mode of %s to uid=" UID_FMT ", gid=" GID_FMT ", mode=%#o: %m", devnode, uid, gid, mode);
                 } else
                         log_device_debug(dev, "Preserve permissions of %s, %#o, uid=%u, gid=%u", devnode, mode, uid, gid);
 
diff --git a/src/udev/udev-rules.c b/src/udev/udev-rules.c
index 96840b272c..696d98a40a 100644
--- a/src/udev/udev-rules.c
+++ b/src/udev/udev-rules.c
@@ -22,6 +22,7 @@
 #include "escape.h"
 #include "fd-util.h"
 #include "fileio.h"
+#include "format-util.h"
 #include "fs-util.h"
 #include "glob-util.h"
 #include "libudev-util.h"
@@ -2591,25 +2592,14 @@ int udev_rules_apply_static_dev_perms(UdevRules *rules) {
                                 else
                                         mode = 0600;
                         }
-                        if (mode != (stats.st_mode & 01777)) {
-                                r = chmod(device_node, mode);
-                                if (r < 0)
-                                        return log_error_errno(errno, "Failed to chmod '%s' %#o: %m",
-                                                               device_node, mode);
-                                else
-                                        log_debug("chmod '%s' %#o", device_node, mode);
-                        }
 
-                        if ((uid != 0 && uid != stats.st_uid) || (gid != 0 && gid != stats.st_gid)) {
-                                r = chown(device_node, uid, gid);
-                                if (r < 0)
-                                        return log_error_errno(errno, "Failed to chown '%s' %u %u: %m",
-                                                               device_node, uid, gid);
-                                else
-                                        log_debug("chown '%s' %u %u", device_node, uid, gid);
-                        }
+                        r = chmod_and_chown(device_node, mode, uid, gid);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to chown/chmod '%s' uid=" UID_FMT ", gid=" GID_FMT ", mode=%#o: %m", device_node, uid, gid, mode);
+                        if (r > 0)
+                                log_debug("chown/chmod '%s' uid=" UID_FMT ", gid=" GID_FMT ", mode=%#o", device_node, uid, gid, mode);
 
-                        utimensat(AT_FDCWD, device_node, NULL, 0);
+                        (void) utimensat(AT_FDCWD, device_node, NULL, 0);
                         break;
                 }
                 case TK_END: