sd-dhcp6: Support deprecated SNTP Configuration Option

Although the SNTP option specified in RFC 4075 has been deprecated, some
servers are still sending NTP information with this option. Use the SNTP
information provided only if the NTP option is not present.

Update the test case as SNTP information is also requested.

5 files changed, 48 insertions, 2 deletions

diff --git a/src/libsystemd-network/dhcp6-lease-internal.h b/src/libsystemd-network/dhcp6-lease-internal.h
index ac7f84366d..037f580eb6 100644
--- a/src/libsystemd-network/dhcp6-lease-internal.h
+++ b/src/libsystemd-network/dhcp6-lease-internal.h
@@ -71,6 +71,8 @@ int dhcp6_lease_set_dns(sd_dhcp6_lease *lease, uint8_t *optval, size_t optlen);
 int dhcp6_lease_set_domains(sd_dhcp6_lease *lease, uint8_t *optval,
                             size_t optlen);
 int dhcp6_lease_set_ntp(sd_dhcp6_lease *lease, uint8_t *optval, size_t optlen);
+int dhcp6_lease_set_sntp(sd_dhcp6_lease *lease, uint8_t *optval,
+                         size_t optlen) ;
 
 int dhcp6_lease_new(sd_dhcp6_lease **ret);
 
diff --git a/src/libsystemd-network/dhcp6-protocol.h b/src/libsystemd-network/dhcp6-protocol.h
index 9330f239b5..b3a28f88b4 100644
--- a/src/libsystemd-network/dhcp6-protocol.h
+++ b/src/libsystemd-network/dhcp6-protocol.h
@@ -123,7 +123,7 @@ enum {
         DHCP6_OPTION_DNS_SERVERS                = 23,  /* RFC 3646 */
         DHCP6_OPTION_DOMAIN_LIST                = 24,  /* RFC 3646 */
 
-        DHCP6_OPTION_SNTP_SERVERS               = 31,  /* RFC 4075 */
+        DHCP6_OPTION_SNTP_SERVERS               = 31,  /* RFC 4075, deprecated */
 
         /* option code 35 is unassigned */
 
diff --git a/src/libsystemd-network/sd-dhcp6-client.c b/src/libsystemd-network/sd-dhcp6-client.c
index 986958d8ad..bc17c6adc5 100644
--- a/src/libsystemd-network/sd-dhcp6-client.c
+++ b/src/libsystemd-network/sd-dhcp6-client.c
@@ -73,6 +73,7 @@ static const uint16_t default_req_opts[] = {
         DHCP6_OPTION_DNS_SERVERS,
         DHCP6_OPTION_DOMAIN_LIST,
         DHCP6_OPTION_NTP_SERVER,
+        DHCP6_OPTION_SNTP_SERVERS,
 };
 
 const char * dhcp6_message_type_table[_DHCP6_MESSAGE_MAX] = {
@@ -774,6 +775,13 @@ static int client_parse_message(sd_dhcp6_client *client,
                                 return r;
 
                         break;
+
+                case DHCP6_OPTION_SNTP_SERVERS:
+                        r = dhcp6_lease_set_sntp(lease, optval, optlen);
+                        if (r < 0)
+                                return r;
+
+                        break;
                 }
 
         }
diff --git a/src/libsystemd-network/sd-dhcp6-lease.c b/src/libsystemd-network/sd-dhcp6-lease.c
index 8631aabc40..f0494b3c91 100644
--- a/src/libsystemd-network/sd-dhcp6-lease.c
+++ b/src/libsystemd-network/sd-dhcp6-lease.c
@@ -257,6 +257,10 @@ int dhcp6_lease_set_ntp(sd_dhcp6_lease *lease, uint8_t *optval, size_t optlen)
         assert_return(lease, -EINVAL);
         assert_return(optval, -EINVAL);
 
+        free(lease->ntp);
+        lease->ntp_count = 0;
+        lease->ntp_allocated = 0;
+
         while ((r = dhcp6_option_parse(&optval, &optlen, &subopt, &sublen,
                                        &subval)) >= 0) {
                 int s;
@@ -299,6 +303,38 @@ int dhcp6_lease_set_ntp(sd_dhcp6_lease *lease, uint8_t *optval, size_t optlen)
         return 0;
 }
 
+int dhcp6_lease_set_sntp(sd_dhcp6_lease *lease, uint8_t *optval, size_t optlen) {
+        int r;
+
+        assert_return(lease, -EINVAL);
+        assert_return(optval, -EINVAL);
+
+        if (!optlen)
+                return 0;
+
+        if (lease->ntp || lease->ntp_fqdn) {
+                log_dhcp6_client(client, "NTP information already provided");
+
+                return 0;
+        }
+
+        log_dhcp6_client(client, "Using deprecated SNTP information");
+
+        r = dhcp6_option_parse_ip6addrs(optval, optlen, &lease->ntp,
+                                        lease->ntp_count,
+                                        &lease->ntp_allocated);
+        if (r < 0) {
+                log_dhcp6_client(client, "Invalid SNTP server option: %s",
+                                 strerror(-r));
+
+                return r;
+        }
+
+        lease->ntp_count = r;
+
+        return 0;
+}
+
 int sd_dhcp6_lease_get_ntp_addrs(sd_dhcp6_lease *lease,
                                  struct in6_addr **addrs) {
         assert_return(lease, -EINVAL);
diff --git a/src/libsystemd-network/test-dhcp6-client.c b/src/libsystemd-network/test-dhcp6-client.c
index 761854714b..b61fd38ade 100644
--- a/src/libsystemd-network/test-dhcp6-client.c
+++ b/src/libsystemd-network/test-dhcp6-client.c
@@ -73,7 +73,7 @@ static int test_client_basic(sd_event *e) {
         assert_se(sd_dhcp6_client_set_request_option(client, DHCP6_OPTION_CLIENTID) == -EINVAL);
         assert_se(sd_dhcp6_client_set_request_option(client, DHCP6_OPTION_DNS_SERVERS) == -EEXIST);
         assert_se(sd_dhcp6_client_set_request_option(client, DHCP6_OPTION_NTP_SERVER) == -EEXIST);
-        assert_se(sd_dhcp6_client_set_request_option(client, DHCP6_OPTION_SNTP_SERVERS) == 0);
+        assert_se(sd_dhcp6_client_set_request_option(client, DHCP6_OPTION_SNTP_SERVERS) == -EEXIST);
         assert_se(sd_dhcp6_client_set_request_option(client, DHCP6_OPTION_DOMAIN_LIST) == -EEXIST);
         assert_se(sd_dhcp6_client_set_request_option(client, 10) == -EINVAL);