Merge pull request #9775 from yuwata/follow-up-9766

5 files changed, 54 insertions, 26 deletions

diff --git a/man/systemd.network.xml b/man/systemd.network.xml
index 8a80b0cf4f..cbf53f323a 100644
--- a/man/systemd.network.xml
+++ b/man/systemd.network.xml
@@ -1194,25 +1194,28 @@
         <varlistentry>
           <term><varname>SendHostname=</varname></term>
           <listitem>
-            <para>When true (the default), the machine's hostname will
-            be sent to the DHCP server.</para>
+            <para>When true (the default), the machine's hostname will be sent to the DHCP server.
+            Note that the machine's hostname must consist only of 7-bit ASCII lower-case characters and
+            no spaces or dots, and be formatted as a valid DNS domain name. Otherwise, the hostname is not
+            sent even if this is set to true.</para>
           </listitem>
         </varlistentry>
         <varlistentry>
           <term><varname>UseHostname=</varname></term>
           <listitem>
             <para>When true (the default), the hostname received from
-            the DHCP server will be set as the transient hostname of the system
+            the DHCP server will be set as the transient hostname of the system.
             </para>
           </listitem>
         </varlistentry>
         <varlistentry>
-        <term><varname>Hostname=</varname></term>
-        <listitem>
-          <para>Use this value for the hostname which is sent to the
-          DHCP server, instead of machine's hostname.</para>
-        </listitem>
-      </varlistentry>
+          <term><varname>Hostname=</varname></term>
+          <listitem>
+            <para>Use this value for the hostname which is sent to the DHCP server, instead of machine's hostname.
+            Note that the specified hostname must consist only of 7-bit ASCII lower-case characters and
+            no spaces or dots, and be formatted as a valid DNS domain name.</para>
+          </listitem>
+        </varlistentry>
         <varlistentry>
           <term><varname>UseDomains=</varname></term>
           <listitem>
diff --git a/src/network/networkd-dhcp4.c b/src/network/networkd-dhcp4.c
index 5616046f4f..08656334e0 100644
--- a/src/network/networkd-dhcp4.c
+++ b/src/network/networkd-dhcp4.c
@@ -599,7 +599,14 @@ static int dhcp4_set_hostname(Link *link) {
                 hn = hostname;
         }
 
-        return sd_dhcp_client_set_hostname(link->dhcp_client, hn);
+        r = sd_dhcp_client_set_hostname(link->dhcp_client, hn);
+        if (r == -EINVAL && hostname)
+                /* Ignore error when the machine's hostname is not suitable to send in DHCP packet. */
+                log_link_warning_errno(link, r, "DHCP4 CLIENT: Failed to set hostname from kernel hostname, ignoring: %m");
+        else if (r < 0)
+                return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set hostname: %m");
+
+        return 0;
 }
 
 static bool promote_secondaries_enabled(const char *ifname) {
@@ -737,7 +744,7 @@ int dhcp4_configure(Link *link) {
 
         r = dhcp4_set_hostname(link);
         if (r < 0)
-                return log_link_error_errno(link, r, "DHCP4 CLIENT: Failed to set hostname: %m");
+                return r;
 
         if (link->network->dhcp_vendor_class_identifier) {
                 r = sd_dhcp_client_set_vendor_class_identifier(link->dhcp_client,
diff --git a/src/network/networkd-dhcp6.c b/src/network/networkd-dhcp6.c
index e954754c20..0ec4deb716 100644
--- a/src/network/networkd-dhcp6.c
+++ b/src/network/networkd-dhcp6.c
@@ -453,7 +453,14 @@ static int dhcp6_set_hostname(sd_dhcp6_client *client, Link *link) {
                 hn = hostname;
         }
 
-        return sd_dhcp6_client_set_fqdn(client, hn);
+        r = sd_dhcp6_client_set_fqdn(client, hn);
+        if (r == -EINVAL && hostname)
+                /* Ignore error when the machine's hostname is not suitable to send in DHCP packet. */
+                log_link_warning_errno(link, r, "DHCP6 CLIENT: Failed to set hostname from kernel hostname, ignoring: %m");
+        else if (r < 0)
+                return log_link_error_errno(link, r, "DHCP6 CLIENT: Failed to set hostname: %m");
+
+        return 0;
 }
 
 int dhcp6_configure(Link *link) {
@@ -497,7 +504,7 @@ int dhcp6_configure(Link *link) {
 
         r = dhcp6_set_hostname(client, link);
         if (r < 0)
-                return log_link_error_errno(link, r, "DHCP6 CLIENT: Failed to set hostname: %m");
+                return r;
 
         r = sd_dhcp6_client_set_ifindex(client, link->ifindex);
         if (r < 0)
diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
index 1f1cdced8f..c8f7c4f98a 100644
--- a/src/network/networkd-network.c
+++ b/src/network/networkd-network.c
@@ -971,7 +971,8 @@ int config_parse_hostname(
                 void *data,
                 void *userdata) {
 
-        char **hostname = data, *hn = NULL;
+        _cleanup_free_ char *hn = NULL;
+        char **hostname = data;
         int r;
 
         assert(filename);
@@ -984,13 +985,20 @@ int config_parse_hostname(
 
         if (!hostname_is_valid(hn, false)) {
                 log_syntax(unit, LOG_ERR, filename, line, 0, "Hostname is not valid, ignoring assignment: %s", rvalue);
-                free(hn);
                 return 0;
         }
 
-        free(*hostname);
-        *hostname = hostname_cleanup(hn);
-        return 0;
+        r = dns_name_is_valid(hn);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r, "Failed to check validity of hostname '%s', ignoring assignment: %m", rvalue);
+                return 0;
+        }
+        if (r == 0) {
+                log_syntax(unit, LOG_ERR, filename, line, 0, "Hostname is not a valid DNS domain name, ignoring assignment: %s", rvalue);
+                return 0;
+        }
+
+        return free_and_replace(*hostname, hn);
 }
 
 int config_parse_timezone(
@@ -1005,7 +1013,8 @@ int config_parse_timezone(
                 void *data,
                 void *userdata) {
 
-        char **datap = data, *tz = NULL;
+        _cleanup_free_ char *tz = NULL;
+        char **datap = data;
         int r;
 
         assert(filename);
@@ -1018,14 +1027,10 @@ int config_parse_timezone(
 
         if (!timezone_is_valid(tz, LOG_ERR)) {
                 log_syntax(unit, LOG_ERR, filename, line, 0, "Timezone is not valid, ignoring assignment: %s", rvalue);
-                free(tz);
                 return 0;
         }
 
-        free(*datap);
-        *datap = tz;
-
-        return 0;
+        return free_and_replace(*datap, tz);
 }
 
 int config_parse_dhcp_server_dns(
diff --git a/src/resolve/resolved-dns-trust-anchor.c b/src/resolve/resolved-dns-trust-anchor.c
index 533e438fae..bf5b07cdd3 100644
--- a/src/resolve/resolved-dns-trust-anchor.c
+++ b/src/resolve/resolved-dns-trust-anchor.c
@@ -218,7 +218,10 @@ static int dns_trust_anchor_load_positive(DnsTrustAnchor *d, const char *path, u
         if (r < 0)
                 return log_warning_errno(r, "Unable to parse domain in line %s:%u: %m", path, line);
 
-        if (!dns_name_is_valid(domain)) {
+        r = dns_name_is_valid(domain);
+        if (r < 0)
+                return log_warning_errno(r, "Failed to chack validity of domain name '%s', at line %s:%u, ignoring line: %m", domain, path, line);
+        if (r == 0) {
                 log_warning("Domain name %s is invalid, at line %s:%u, ignoring line.", domain, path, line);
                 return -EINVAL;
         }
@@ -385,7 +388,10 @@ static int dns_trust_anchor_load_negative(DnsTrustAnchor *d, const char *path, u
         if (r < 0)
                 return log_warning_errno(r, "Unable to parse line %s:%u: %m", path, line);
 
-        if (!dns_name_is_valid(domain)) {
+        r = dns_name_is_valid(domain);
+        if (r < 0)
+                return log_warning_errno(r, "Failed to chack validity of domain name '%s', at line %s:%u, ignoring line: %m", domain, path, line);
+        if (r == 0) {
                 log_warning("Domain name %s is invalid, at line %s:%u, ignoring line.", domain, path, line);
                 return -EINVAL;
         }