From 9e9322c41e94e95c3dd4841334933a6c8ef11fd1 Mon Sep 17 00:00:00 2001 From: Tobias Waldekranz Date: Thu, 16 May 2024 14:51:54 +0200 Subject: [PATCH 09/50] net: bridge: Differentiate MDB additions from modifications Before this change, the reception of an IGMPv3 report (and analogously for MLDv2) that adds a new group, would trigger two MDB RTM_NEWMDB notifications from br_ip4_multicast_igmp3_report(): 1. In br_ip4_multicast_add_group() when creating the entry 2. Directly at the end of br_ip4_multicast_igmp3_report(), as the new group is also deemed to be "changed" The corresponding switchdev notifications generated by these present a problem for drivers wanting to reference count group memberships, since logically there is only a single reference to the group. Indeed, when the membership eventually times out, only a single RTM_DELMDB is generated. Therefore, discriminate new groups from changes to existing groups by introducing a RTM_SETMDB events to be used in the latter scenario. --- include/uapi/linux/rtnetlink.h | 2 ++ net/bridge/br_mdb.c | 4 ++-- net/bridge/br_multicast.c | 8 ++++---- 3 files changed, 8 insertions(+), 6 deletions(-) diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h index dab9493c791b..40a3534f0f1d 100644 --- a/include/uapi/linux/rtnetlink.h +++ b/include/uapi/linux/rtnetlink.h @@ -142,6 +142,8 @@ enum { #define RTM_DELMDB RTM_DELMDB RTM_GETMDB = 86, #define RTM_GETMDB RTM_GETMDB + RTM_SETMDB = 87, +#define RTM_SETMDB RTM_SETMDB RTM_NEWNSID = 88, #define RTM_NEWNSID RTM_NEWNSID diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c index 400eb872b403..cd7a2cd0911a 100644 --- a/net/bridge/br_mdb.c +++ b/net/bridge/br_mdb.c @@ -752,7 +752,7 @@ static int br_mdb_replace_group_sg(const struct br_mdb_config *cfg, else timer_delete(&pg->timer); - br_mdb_notify(cfg->br->dev, mp, pg, RTM_NEWMDB); + br_mdb_notify(cfg->br->dev, mp, pg, RTM_SETMDB); return 0; } @@ -973,7 +973,7 @@ static int br_mdb_replace_group_star_g(const struct br_mdb_config *cfg, else timer_delete(&pg->timer); - br_mdb_notify(cfg->br->dev, mp, pg, RTM_NEWMDB); + br_mdb_notify(cfg->br->dev, mp, pg, RTM_SETMDB); if (br_multicast_should_handle_mode(brmctx, cfg->group.proto)) br_multicast_star_g_handle_mode(pg, cfg->filter_mode); diff --git a/net/bridge/br_multicast.c b/net/bridge/br_multicast.c index bfb38b18c1da..cc7ce7fc6580 100644 --- a/net/bridge/br_multicast.c +++ b/net/bridge/br_multicast.c @@ -616,7 +616,7 @@ static void br_multicast_fwd_src_handle(struct net_bridge_group_src *src) sg_mp = br_mdb_ip_get(src->br, &sg_key.addr); if (!sg_mp) return; - br_mdb_notify(src->br->dev, sg_mp, sg, RTM_NEWMDB); + br_mdb_notify(src->br->dev, sg_mp, sg, RTM_SETMDB); } } @@ -884,7 +884,7 @@ static void br_multicast_port_group_expired(struct timer_list *t) if (WARN_ON(!mp)) goto out; - br_mdb_notify(br->dev, mp, pg, RTM_NEWMDB); + br_mdb_notify(br->dev, mp, pg, RTM_SETMDB); } out: spin_unlock(&br->multicast_lock); @@ -2949,7 +2949,7 @@ static int br_ip4_multicast_igmp3_report(struct net_bridge_mcast *brmctx, break; } if (changed) - br_mdb_notify(brmctx->br->dev, mdst, pg, RTM_NEWMDB); + br_mdb_notify(brmctx->br->dev, mdst, pg, RTM_SETMDB); unlock_continue: spin_unlock(&brmctx->br->multicast_lock); } @@ -3091,7 +3091,7 @@ static int br_ip6_multicast_mld2_report(struct net_bridge_mcast *brmctx, break; } if (changed) - br_mdb_notify(brmctx->br->dev, mdst, pg, RTM_NEWMDB); + br_mdb_notify(brmctx->br->dev, mdst, pg, RTM_SETMDB); unlock_continue: spin_unlock(&brmctx->br->multicast_lock); }