network: dhcp6: request DNS servers or friends only when they will be used

diff --git a/src/libsystemd-network/sd-dhcp6-client.c b/src/libsystemd-network/sd-dhcp6-client.c
index cabeaa662068cf7a7a2b930a8ab71851b3457607..3903318be5e2a24c6e35cdb36efee47e53a62cf2 100644 (file)
--- a/src/libsystemd-network/sd-dhcp6-client.c
+++ b/src/libsystemd-network/sd-dhcp6-client.c
@@ -27,14 +27,6 @@
 #include "strv.h"
 #include "web-util.h"
 
-/* Keep the list sorted. */
-static const uint16_t default_req_opts[] = {
-        SD_DHCP6_OPTION_DNS_SERVER,  /* 23 */
-        SD_DHCP6_OPTION_DOMAIN,      /* 24 */
-        SD_DHCP6_OPTION_SNTP_SERVER, /* 31 */
-        SD_DHCP6_OPTION_NTP_SERVER,  /* 56 */
-};
-
 #define DHCP6_CLIENT_DONT_DESTROY(client) \
         _cleanup_(sd_dhcp6_client_unrefp) _unused_ sd_dhcp6_client *_dont_destroy_##client = sd_dhcp6_client_ref(client)
 
@@ -1421,17 +1413,9 @@ DEFINE_TRIVIAL_REF_UNREF_FUNC(sd_dhcp6_client, sd_dhcp6_client, dhcp6_client_fre
 
 int sd_dhcp6_client_new(sd_dhcp6_client **ret) {
         _cleanup_(sd_dhcp6_client_unrefp) sd_dhcp6_client *client = NULL;
-        _cleanup_free_ be16_t *req_opts = NULL;
 
         assert_return(ret, -EINVAL);
 
-        req_opts = new(be16_t, ELEMENTSOF(default_req_opts));
-        if (!req_opts)
-                return -ENOMEM;
-
-        for (size_t t = 0; t < ELEMENTSOF(default_req_opts); t++)
-                req_opts[t] = htobe16(default_req_opts[t]);
-
         client = new(sd_dhcp6_client, 1);
         if (!client)
                 return -ENOMEM;
@@ -1443,8 +1427,6 @@ int sd_dhcp6_client_new(sd_dhcp6_client **ret) {
                 .ifindex = -1,
                 .request_ia = DHCP6_REQUEST_IA_NA | DHCP6_REQUEST_IA_PD,
                 .fd = -1,
-                .n_req_opts = ELEMENTSOF(default_req_opts),
-                .req_opts = TAKE_PTR(req_opts),
         };
 
         *ret = TAKE_PTR(client);

diff --git a/src/libsystemd-network/test-dhcp6-client.c b/src/libsystemd-network/test-dhcp6-client.c
index 7943778e8cd5ac3d92d5f494046c9440da19835b..f32f5a202c4cc231dec979f2bcfeccb71263f0e1 100644 (file)
--- a/src/libsystemd-network/test-dhcp6-client.c
+++ b/src/libsystemd-network/test-dhcp6-client.c
@@ -97,13 +97,13 @@ TEST(client_basic) {
         assert_se(sd_dhcp6_client_set_fqdn(client, "~host.domain") == -EINVAL);
 
         assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_CLIENTID) == -EINVAL);
-        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_DNS_SERVER) == -EEXIST);
-        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_NTP_SERVER) == -EEXIST);
-        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_SNTP_SERVER) == -EEXIST);
-        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_DOMAIN) == -EEXIST);
+        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_DNS_SERVER) >= 0);
+        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_NTP_SERVER) >= 0);
+        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_SNTP_SERVER) >= 0);
+        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_DOMAIN) >= 0);
         assert_se(sd_dhcp6_client_set_request_option(client, 10) == -EINVAL);
-        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_NIS_SERVER) == 0);
-        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_NISP_SERVER) == 0);
+        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_NIS_SERVER) >= 0);
+        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_NISP_SERVER) >= 0);
         assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_NIS_SERVER) == -EEXIST);
         assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_NISP_SERVER) == -EEXIST);
 
@@ -977,6 +977,11 @@ TEST(dhcp6_client) {
         assert_se(sd_dhcp6_client_set_iaid(client, unaligned_read_be32((uint8_t[]) { IA_ID_BYTES })) >= 0);
         dhcp6_client_set_test_mode(client, true);
 
+        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_DNS_SERVER) >= 0);
+        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_DOMAIN) >= 0);
+        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_NTP_SERVER) >= 0);
+        assert_se(sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_SNTP_SERVER) >= 0);
+
         assert_se(sd_dhcp6_client_set_information_request(client, true) >= 0);
         assert_se(sd_dhcp6_client_set_callback(client, test_client_callback, NULL) >= 0);
 

diff --git a/src/network/networkd-dhcp6.c b/src/network/networkd-dhcp6.c
index d4b61ad79e6e7f864f7147d0c9536bcab16426a5..16014dbaff917a50211ea87ce62a9b00ebecd380 100644 (file)
--- a/src/network/networkd-dhcp6.c
+++ b/src/network/networkd-dhcp6.c
@@ -622,6 +622,29 @@ static int dhcp6_configure(Link *link) {
                         return log_link_debug_errno(link, r, "DHCPv6 CLIENT: Failed to set MUD URL: %m");
         }
 
+        if (link->network->dhcp6_use_dns) {
+                r = sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_DNS_SERVER);
+                if (r < 0)
+                        return log_link_debug_errno(link, r, "DHCPv6 CLIENT: Failed to request DNS servers: %m");
+        }
+
+        if (link->network->dhcp6_use_domains > 0) {
+                r = sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_DOMAIN);
+                if (r < 0)
+                        return log_link_debug_errno(link, r, "DHCPv6 CLIENT: Failed to request domains: %m");
+        }
+
+        if (link->network->dhcp6_use_ntp) {
+                r = sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_NTP_SERVER);
+                if (r < 0)
+                        return log_link_debug_errno(link, r, "DHCPv6 CLIENT: Failed to request NTP servers: %m");
+
+                /* If the server does not provide NTP servers, then we fallback to use SNTP servers. */
+                r = sd_dhcp6_client_set_request_option(client, SD_DHCP6_OPTION_SNTP_SERVER);
+                if (r < 0)
+                        return log_link_debug_errno(link, r, "DHCPv6 CLIENT: Failed to request SNTP servers: %m");
+        }
+
         SET_FOREACH(request_options, link->network->dhcp6_request_options) {
                 uint32_t option = PTR_TO_UINT32(request_options);