sd-dhcp6: fix check if serverid is set

keszybz · keszybz · commit 99f1d3fc5043 · 2018-02-15T10:04:02.000+01:00
Ever since the initial implementation in 631bbe7, client_parse_message() was supposed to check that the message contains exactly one serverid. The check that no more than one is given was implemented correctly, but the check that at least one is given was not. Simplify the whole thing by making dhcp6_lease_get_serverid() return an error if the id is not set, and do not require the arguments to be present if the contents of the id are not needed.
diff --git a/src/libsystemd-network/sd-dhcp6-client.c b/src/libsystemd-network/sd-dhcp6-client.c
@@ -771,8 +771,6 @@ static int client_parse_message(
         size_t pos = 0;
         int r;
         bool clientid = false;
-        uint8_t *id = NULL;
-        size_t id_len;
         uint32_t lt_t1 = ~0, lt_t2 = ~0;
 
         assert(client);
@@ -817,8 +815,8 @@ static int client_parse_message(
                         break;
 
                 case SD_DHCP6_OPTION_SERVERID:
-                        r = dhcp6_lease_get_serverid(lease, &id, &id_len);
-                        if (r >= 0 && id) {
+                        r = dhcp6_lease_get_serverid(lease, NULL, NULL);
+                        if (r >= 0) {
                                 log_dhcp6_client(client, "%s contains multiple serverids",
                                                  dhcp6_message_type_to_string(message->type));
                                 return -EINVAL;
@@ -956,21 +954,23 @@ static int client_parse_message(
         }
 
         if (client->state != DHCP6_STATE_INFORMATION_REQUEST) {
-                r = dhcp6_lease_get_serverid(lease, &id, &id_len);
-                if (r < 0)
+                r = dhcp6_lease_get_serverid(lease, NULL, NULL);
+                if (r < 0) {
                         log_dhcp6_client(client, "%s has no server id",
                                          dhcp6_message_type_to_string(message->type));
-                return r;
-        }
+                        return -EINVAL;
+                }
 
-        if (lease->ia.addresses) {
-                lease->ia.ia_na.lifetime_t1 = htobe32(lt_t1);
-                lease->ia.ia_na.lifetime_t2 = htobe32(lt_t2);
-        }
+        } else {
+                if (lease->ia.addresses) {
+                        lease->ia.ia_na.lifetime_t1 = htobe32(lt_t1);
+                        lease->ia.ia_na.lifetime_t2 = htobe32(lt_t2);
+                }
 
-        if (lease->pd.addresses) {
-                lease->pd.ia_pd.lifetime_t1 = htobe32(lt_t1);
-                lease->pd.ia_pd.lifetime_t2 = htobe32(lt_t2);
+                if (lease->pd.addresses) {
+                        lease->pd.ia_pd.lifetime_t1 = htobe32(lt_t1);
+                        lease->pd.ia_pd.lifetime_t2 = htobe32(lt_t2);
+                }
         }
 
         return 0;
diff --git a/src/libsystemd-network/sd-dhcp6-lease.c b/src/libsystemd-network/sd-dhcp6-lease.c
@@ -95,11 +95,14 @@ int dhcp6_lease_set_serverid(sd_dhcp6_lease *lease, const uint8_t *id,
 
 int dhcp6_lease_get_serverid(sd_dhcp6_lease *lease, uint8_t **id, size_t *len) {
         assert_return(lease, -EINVAL);
-        assert_return(id, -EINVAL);
-        assert_return(len, -EINVAL);
 
-        *id = lease->serverid;
-        *len = lease->serverid_len;
+        if (!lease->serverid)
+                return -ENOMSG;
+
+        if (id)
+                *id = lease->serverid;
+        if (len)
+                *len = lease->serverid_len;
 
         return 0;
 }
