Merge pull request #21941 from yuwata/hostname-handle-empty

hostname-setup: support kernel with empty CONFIG_DEFAULT_HOSTNAME

4 files changed, 13 insertions, 15 deletions

diff --git a/src/basic/hostname-util.c b/src/basic/hostname-util.c
index 1d0640e075..136fb3e595 100644
--- a/src/basic/hostname-util.c
+++ b/src/basic/hostname-util.c
@@ -46,8 +46,7 @@ int gethostname_full(GetHostnameFlags flags, char **ret) {
         assert_se(uname(&u) >= 0);
 
         s = u.nodename;
-        if (isempty(s) ||
-            (!FLAGS_SET(flags, GET_HOSTNAME_ALLOW_NONE) && streq(s, "(none)")) ||
+        if (isempty(s) || streq(s, "(none)") ||
             (!FLAGS_SET(flags, GET_HOSTNAME_ALLOW_LOCALHOST) && is_localhost(s)) ||
             (FLAGS_SET(flags, GET_HOSTNAME_SHORT) && s[0] == '.')) {
                 if (!FLAGS_SET(flags, GET_HOSTNAME_FALLBACK_DEFAULT))
diff --git a/src/basic/hostname-util.h b/src/basic/hostname-util.h
index 0d1574db9e..d435bed50e 100644
--- a/src/basic/hostname-util.h
+++ b/src/basic/hostname-util.h
@@ -9,10 +9,9 @@
 #include "strv.h"
 
 typedef enum GetHostnameFlags {
-        GET_HOSTNAME_ALLOW_NONE       = 1 << 0, /* accepts "(none)". */
-        GET_HOSTNAME_ALLOW_LOCALHOST  = 1 << 1, /* accepts "localhost" or friends. */
-        GET_HOSTNAME_FALLBACK_DEFAULT = 1 << 2, /* use default hostname if no hostname is set. */
-        GET_HOSTNAME_SHORT            = 1 << 3, /* kills the FQDN part if present. */
+        GET_HOSTNAME_ALLOW_LOCALHOST  = 1 << 0, /* accepts "localhost" or friends. */
+        GET_HOSTNAME_FALLBACK_DEFAULT = 1 << 1, /* use default hostname if no hostname is set. */
+        GET_HOSTNAME_SHORT            = 1 << 2, /* kills the FQDN part if present. */
 } GetHostnameFlags;
 
 int gethostname_full(GetHostnameFlags flags, char **ret);
diff --git a/src/shared/hostname-setup.c b/src/shared/hostname-setup.c
index 1329b0d189..0fac0ecab7 100644
--- a/src/shared/hostname-setup.c
+++ b/src/shared/hostname-setup.c
@@ -20,16 +20,13 @@
 #include "util.h"
 
 static int sethostname_idempotent_full(const char *s, bool really) {
-        _cleanup_free_ char *buf = NULL;
-        int r;
+        struct utsname u;
 
         assert(s);
 
-        r = gethostname_full(GET_HOSTNAME_ALLOW_NONE | GET_HOSTNAME_ALLOW_LOCALHOST, &buf);
-        if (r < 0)
-                return r;
+        assert_se(uname(&u) >= 0);
 
-        if (streq(buf, s))
+        if (streq_ptr(s, u.nodename))
                 return 0;
 
         if (really &&
diff --git a/src/test/test-sysctl-util.c b/src/test/test-sysctl-util.c
index 6464a7965b..8bd3c26152 100644
--- a/src/test/test-sysctl-util.c
+++ b/src/test/test-sysctl-util.c
@@ -1,5 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+#include <sys/utsname.h>
+
 #include "sd-id128.h"
 
 #include "errno-util.h"
@@ -38,7 +40,8 @@ TEST(sysctl_normalize) {
 }
 
 TEST(sysctl_read) {
-        _cleanup_free_ char *s = NULL, *h = NULL;
+        _cleanup_free_ char *s = NULL;
+        struct utsname u;
         sd_id128_t a, b;
         int r;
 
@@ -63,8 +66,8 @@ TEST(sysctl_read) {
         s = mfree(s);
 
         assert_se(sysctl_read("kernel/hostname", &s) >= 0);
-        assert_se(gethostname_full(GET_HOSTNAME_ALLOW_NONE|GET_HOSTNAME_ALLOW_LOCALHOST, &h) >= 0);
-        assert_se(streq(s, h));
+        assert_se(uname(&u) >= 0);
+        assert_se(streq_ptr(s, u.nodename));
 
         r = sysctl_write("kernel/hostname", s);
         assert_se(r >= 0 || ERRNO_IS_PRIVILEGE(r) || r == -EROFS);