lacp: review follow-ups

lacp_in() always leaves uip_len at 0, so the tcpip_output() after it
never ran. The LAG page names the active members by front-panel port
instead of a logical mask. The partner key is not part of selection;
say so under Known limits.

doc/lacp.md

@@ -228,4 +228,6 @@ the dead member.
 * No Churn Detection machines and no Marker protocol.
 * Coupled Mux: collecting and distributing are enabled together.
 * One aggregator per group.
+* Selection compares the partner's system only, not its key: two aggregates
+  that one partner system offers on the same group land in one trunk here.
 * Member compatibility is not validated; see #377.

html/app.js

@@ -1843,6 +1843,7 @@ function buildLag(){
   })(g);
 }
 var lacpCfg=[0,0,0,0,0];
+function maskPorts(m){var r=[];for(var p=1;p<=S.n;p++)if((m>>S.physToLog[p-1])&1)r.push(p);return r.length?r.join(" "):"-"}
 function lagLoad(){
   return getJSON("/lacp.json").then(function(c){
     var tb=$("lacptbl").tBodies[0];
@@ -1852,7 +1853,7 @@ function lagLoad(){
       lacpCfg[g]=parseInt(lg.cfg,16);
       if($("lgm"+g).closest(".card").dataset.dirty)return;
       $("lgm"+g).value=lacpCfg[g]?"lacp":"static";
-      $("lgs"+g).textContent=lacpCfg[g]?"LACP: "+t("lacp_agg")+" "+(lg.aggValid?lg.agg:"("+t("lacp_neg")+")")+", "+t("lacp_members")+" 0x"+lg.members:"";
+      $("lgs"+g).textContent=lacpCfg[g]?"LACP: "+t("lacp_agg")+" "+(lg.aggValid?lg.agg:"("+t("lacp_neg")+")")+", "+t("lacp_members")+" "+maskPorts(parseInt(lg.members,16)):"";
     });
     if(c.on)c.ports.forEach(function(p){
       if(p.lag===255)return;

rtlplayground.c

@@ -1071,8 +1071,6 @@ void handle_rx(void)
 				}
 			} else if (lacpEnabled && uip_buf[5] == 0x02) {	// LACPDU (slow protocols)
 				lacp_in();
-				if (uip_len)
-					tcpip_output();
 			}
 		} else if (igmpEnabled && uip_buf[0] == 0x01 && uip_buf[1] == 0x00 && uip_buf[2] == 0x5e // IPv4-MC packet?
 			&& igmp_packet_handler()) {