From: Ben Pfaff Date: Wed, 10 Jun 2009 22:24:03 +0000 (-0700) Subject: vswitch: Fix handling of multicast packets received by bonds. X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c93b1d6a4c7f96c5f75f7ec0972fe62e94d369dc;p=openvswitch vswitch: Fix handling of multicast packets received by bonds. As long as bonding has been implemented, the vswitch has refused to learn from multicast packets that arrive on a bond slave if it has already learned any other port for that source MAC, because it is likely that we sent the packet out ourselves and are only now receiving a copy of it on our active slave. This is entirely correct, but it does not go far enough. In fact, the bridge needs to entirely drop such packets. Otherwise, a host whose MAC is assigned to a slave other than the active slave will receive a second copy of multicast packets that it sends out the bond, and other ports will receive two copies of every multicast packet sent by such a host. This commit implements this new policy, which simplifies the code at the same time. Bug #1387. --- diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c index b266c105..10c6fee2 100644 --- a/vswitchd/bridge.c +++ b/vswitchd/bridge.c @@ -1,5 +1,5 @@ /* Copyright (c) 2008, 2009 Nicira Networks - * + * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or @@ -1744,12 +1744,25 @@ process_flow(struct bridge *br, const flow_t *flow, goto done; } - /* Drop multicast and broadcast packets on inactive bonded interfaces, to + /* Multicast (and broadcast) packets on bonds need special attention, to * avoid receiving duplicates. */ if (in_port->n_ifaces > 1 && eth_addr_is_multicast(flow->dl_dst)) { *tags |= in_port->active_iface_tag; if (in_port->active_iface != in_iface->port_ifidx) { + /* Drop all multicast packets on inactive slaves. */ goto done; + } else { + /* Drop all multicast packets for which we have learned a different + * input port, because we probably sent the packet on one slaves + * and got it back on the active slave. Broadcast ARP replies are + * an exception to this rule: the host has moved to another + * switch. */ + int src_idx = mac_learning_lookup(br->ml, flow->dl_src, vlan); + if (src_idx != -1 + && src_idx != in_port->port_idx + && !is_bcast_arp_reply(flow, packet)) { + goto done; + } } } @@ -1757,27 +1770,9 @@ process_flow(struct bridge *br, const flow_t *flow, out_port = FLOOD_PORT; if (br->ml) { int out_port_idx; - bool may_learn; - - if (!packet) { - /* Don't try to learn from revalidation. */ - may_learn = false; - } else if (in_port->n_ifaces > 1) { - /* If the packet arrived on a bonded port, don't learn from it - * unless we haven't learned any port at all for that address - * (because we probably sent the packet on one bonded interface and - * got it back on the other). Broadcast ARP replies are an - * exception to this rule: the host has moved to another switch. */ - int src_idx = mac_learning_lookup(br->ml, flow->dl_src, vlan); - may_learn = (src_idx < 0 - || src_idx == in_port->port_idx - || is_bcast_arp_reply(flow, packet)); - } else { - may_learn = true; - } - /* Learn source MAC. */ - if (may_learn) { + /* Learn source MAC (but don't try to learn from revalidation). */ + if (packet) { tag_type rev_tag = mac_learning_learn(br->ml, flow->dl_src, vlan, in_port->port_idx); if (rev_tag) {