refine tos setsockopt in redir and udprelay

make tos setup working at ipv4 and ipv6

src/redir.c

@@ -752,8 +752,13 @@ accept_cb(EV_P_ ev_io *w, int revents)
     setnonblocking(remotefd);
 
     if (listener->tos >= 0) {
-        if (setsockopt(remotefd, IPPROTO_IP, IP_TOS, &listener->tos, sizeof(listener->tos)) != 0) {
-            ERROR("setsockopt IP_TOS");
+        int rc = setsockopt(remotefd, IPPROTO_IP, IP_TOS, &listener->tos, sizeof(listener->tos));
+        if (rc < 0 && errno != ENOPROTOOPT) {
+            LOGE("setting ipv4 dscp failed: %d", errno);
+        }
+        rc = setsockopt(remotefd, IPPROTO_IPV6, IPV6_TCLASS, &listener->tos, sizeof(listener->tos));
+        if (rc < 0 && errno != ENOPROTOOPT) {
+            LOGE("setting ipv6 dscp failed: %d", errno);
         }
     }
 

src/udprelay.c

@@ -497,8 +497,14 @@ create_server_socket(const char *host, const char *port)
 #ifdef IP_TOS
         // Set QoS flag
         int tos   = 46 << 2;
-        int proto = rp->ai_family == AF_INET6 ? IPPROTO_IP : IPPROTO_IPV6;
-        setsockopt(server_sock, proto, IP_TOS, &tos, sizeof(tos));
+        int rc = setsockopt(server_sock, IPPROTO_IP, IP_TOS, &tos, sizeof(tos));
+        if (rc < 0 && errno != ENOPROTOOPT) {
+            LOGE("setting ipv4 dscp failed: %d", errno);
+        }
+        rc = setsockopt(server_sock, IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos));
+        if (rc < 0 && errno != ENOPROTOOPT) {
+            LOGE("setting ipv6 dscp failed: %d", errno);
+        }
 #endif
 
 #ifdef MODULE_REDIR