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net: bridge: mcast: add support for group source list
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Initial functions for group source lists which are needed for IGMPv3
and MLDv2 include/exclude lists. Both IPv4 and IPv6 sources are supported.
User-added mdb entries are created with exclude filter mode, we can
extend that later to allow user-supplied mode. When group src entries
are deleted, they're freed from a workqueue to make sure their timers
are not still running. Source entries are protected by the multicast_lock
and rcu. The number of src groups per port group is limited to 32.

v4: use the new port group del function directly
    add igmpv2/mldv1 bool to denote if the entry was added in those
    modes, it will later replace the old update_timer bool
v3: add IPv6 support
v2: allow src groups to be traversed under rcu

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Nikolay Aleksandrov authored and Jakub Kicinski committed Sep 7, 2020
1 parent 681590b commit 8b67177
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Showing 3 changed files with 179 additions and 14 deletions.
3 changes: 2 additions & 1 deletion net/bridge/br_mdb.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -638,7 +638,8 @@ static int br_mdb_add_group(struct net_bridge *br, struct net_bridge_port *port,
break;
}

p = br_multicast_new_port_group(port, group, *pp, state, NULL);
p = br_multicast_new_port_group(port, group, *pp, state, NULL,
MCAST_EXCLUDE);
if (unlikely(!p))
return -ENOMEM;
rcu_assign_pointer(*pp, p);
Expand Down
164 changes: 152 additions & 12 deletions net/bridge/br_multicast.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -163,15 +163,29 @@ static void br_multicast_group_expired(struct timer_list *t)
spin_unlock(&br->multicast_lock);
}

static void br_multicast_del_group_src(struct net_bridge_group_src *src)
{
struct net_bridge *br = src->pg->port->br;

hlist_del_init_rcu(&src->node);
src->pg->src_ents--;
hlist_add_head(&src->del_node, &br->src_gc_list);
queue_work(system_long_wq, &br->src_gc_work);
}

void br_multicast_del_pg(struct net_bridge_mdb_entry *mp,
struct net_bridge_port_group *pg,
struct net_bridge_port_group __rcu **pp)
{
struct net_bridge *br = pg->port->br;
struct net_bridge_group_src *ent;
struct hlist_node *tmp;

rcu_assign_pointer(*pp, pg->next);
hlist_del_init(&pg->mglist);
del_timer(&pg->timer);
hlist_for_each_entry_safe(ent, tmp, &pg->src_list, node)
br_multicast_del_group_src(ent);
br_mdb_notify(br->dev, pg->port, &pg->addr, RTM_DELMDB, pg->flags);
kfree_rcu(pg, rcu);

Expand All @@ -182,9 +196,9 @@ void br_multicast_del_pg(struct net_bridge_mdb_entry *mp,
static void br_multicast_find_del_pg(struct net_bridge *br,
struct net_bridge_port_group *pg)
{
struct net_bridge_port_group __rcu **pp;
struct net_bridge_mdb_entry *mp;
struct net_bridge_port_group *p;
struct net_bridge_port_group __rcu **pp;

mp = br_mdb_ip_get(br, &pg->addr);
if (WARN_ON(!mp))
Expand Down Expand Up @@ -476,12 +490,96 @@ struct net_bridge_mdb_entry *br_multicast_new_group(struct net_bridge *br,
return mp;
}

static void br_multicast_group_src_expired(struct timer_list *t)
{
struct net_bridge_group_src *src = from_timer(src, t, timer);
struct net_bridge_port_group *pg;
struct net_bridge *br = src->br;

spin_lock(&br->multicast_lock);
if (hlist_unhashed(&src->node) || !netif_running(br->dev) ||
timer_pending(&src->timer))
goto out;

pg = src->pg;
if (pg->filter_mode == MCAST_INCLUDE) {
br_multicast_del_group_src(src);
if (!hlist_empty(&pg->src_list))
goto out;
br_multicast_find_del_pg(br, pg);
}
out:
spin_unlock(&br->multicast_lock);
}

static struct net_bridge_group_src *
br_multicast_find_group_src(struct net_bridge_port_group *pg, struct br_ip *ip)
{
struct net_bridge_group_src *ent;

switch (ip->proto) {
case htons(ETH_P_IP):
hlist_for_each_entry(ent, &pg->src_list, node)
if (ip->u.ip4 == ent->addr.u.ip4)
return ent;
break;
#if IS_ENABLED(CONFIG_IPV6)
case htons(ETH_P_IPV6):
hlist_for_each_entry(ent, &pg->src_list, node)
if (!ipv6_addr_cmp(&ent->addr.u.ip6, &ip->u.ip6))
return ent;
break;
#endif
}

return NULL;
}

static struct net_bridge_group_src *
br_multicast_new_group_src(struct net_bridge_port_group *pg, struct br_ip *src_ip)
{
struct net_bridge_group_src *grp_src;

if (unlikely(pg->src_ents >= PG_SRC_ENT_LIMIT))
return NULL;

switch (src_ip->proto) {
case htons(ETH_P_IP):
if (ipv4_is_zeronet(src_ip->u.ip4) ||
ipv4_is_multicast(src_ip->u.ip4))
return NULL;
break;
#if IS_ENABLED(CONFIG_IPV6)
case htons(ETH_P_IPV6):
if (ipv6_addr_any(&src_ip->u.ip6) ||
ipv6_addr_is_multicast(&src_ip->u.ip6))
return NULL;
break;
#endif
}

grp_src = kzalloc(sizeof(*grp_src), GFP_ATOMIC);
if (unlikely(!grp_src))
return NULL;

grp_src->pg = pg;
grp_src->br = pg->port->br;
grp_src->addr = *src_ip;
timer_setup(&grp_src->timer, br_multicast_group_src_expired, 0);

hlist_add_head_rcu(&grp_src->node, &pg->src_list);
pg->src_ents++;

return grp_src;
}

struct net_bridge_port_group *br_multicast_new_port_group(
struct net_bridge_port *port,
struct br_ip *group,
struct net_bridge_port_group __rcu *next,
unsigned char flags,
const unsigned char *src)
const unsigned char *src,
u8 filter_mode)
{
struct net_bridge_port_group *p;

Expand All @@ -492,6 +590,8 @@ struct net_bridge_port_group *br_multicast_new_port_group(
p->addr = *group;
p->port = port;
p->flags = flags;
p->filter_mode = filter_mode;
INIT_HLIST_HEAD(&p->src_list);
rcu_assign_pointer(p->next, next);
hlist_add_head(&p->mglist, &port->mglist);
timer_setup(&p->timer, br_multicast_port_group_expired, 0);
Expand Down Expand Up @@ -541,7 +641,8 @@ void br_multicast_host_leave(struct net_bridge_mdb_entry *mp, bool notify)
static int br_multicast_add_group(struct net_bridge *br,
struct net_bridge_port *port,
struct br_ip *group,
const unsigned char *src)
const unsigned char *src,
u8 filter_mode)
{
struct net_bridge_port_group __rcu **pp;
struct net_bridge_port_group *p;
Expand Down Expand Up @@ -573,7 +674,7 @@ static int br_multicast_add_group(struct net_bridge *br,
break;
}

p = br_multicast_new_port_group(port, group, *pp, 0, src);
p = br_multicast_new_port_group(port, group, *pp, 0, src, filter_mode);
if (unlikely(!p))
goto err;
rcu_assign_pointer(*pp, p);
Expand All @@ -593,9 +694,11 @@ static int br_ip4_multicast_add_group(struct net_bridge *br,
struct net_bridge_port *port,
__be32 group,
__u16 vid,
const unsigned char *src)
const unsigned char *src,
bool igmpv2)
{
struct br_ip br_group;
u8 filter_mode;

if (ipv4_is_local_multicast(group))
return 0;
Expand All @@ -604,18 +707,21 @@ static int br_ip4_multicast_add_group(struct net_bridge *br,
br_group.u.ip4 = group;
br_group.proto = htons(ETH_P_IP);
br_group.vid = vid;
filter_mode = igmpv2 ? MCAST_EXCLUDE : MCAST_INCLUDE;

return br_multicast_add_group(br, port, &br_group, src);
return br_multicast_add_group(br, port, &br_group, src, filter_mode);
}

#if IS_ENABLED(CONFIG_IPV6)
static int br_ip6_multicast_add_group(struct net_bridge *br,
struct net_bridge_port *port,
const struct in6_addr *group,
__u16 vid,
const unsigned char *src)
const unsigned char *src,
bool mldv1)
{
struct br_ip br_group;
u8 filter_mode;

if (ipv6_addr_is_ll_all_nodes(group))
return 0;
Expand All @@ -624,8 +730,9 @@ static int br_ip6_multicast_add_group(struct net_bridge *br,
br_group.u.ip6 = *group;
br_group.proto = htons(ETH_P_IPV6);
br_group.vid = vid;
filter_mode = mldv1 ? MCAST_EXCLUDE : MCAST_INCLUDE;

return br_multicast_add_group(br, port, &br_group, src);
return br_multicast_add_group(br, port, &br_group, src, filter_mode);
}
#endif

Expand Down Expand Up @@ -974,7 +1081,7 @@ static int br_ip4_multicast_igmp3_report(struct net_bridge *br,
br_ip4_multicast_leave_group(br, port, group, vid, src);
} else {
err = br_ip4_multicast_add_group(br, port, group, vid,
src);
src, true);
if (err)
break;
}
Expand Down Expand Up @@ -1053,7 +1160,7 @@ static int br_ip6_multicast_mld2_report(struct net_bridge *br,
} else {
err = br_ip6_multicast_add_group(br, port,
&grec->grec_mca, vid,
src);
src, true);
if (err)
break;
}
Expand Down Expand Up @@ -1625,7 +1732,8 @@ static int br_multicast_ipv4_rcv(struct net_bridge *br,
case IGMP_HOST_MEMBERSHIP_REPORT:
case IGMPV2_HOST_MEMBERSHIP_REPORT:
BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
err = br_ip4_multicast_add_group(br, port, ih->group, vid, src);
err = br_ip4_multicast_add_group(br, port, ih->group, vid, src,
true);
break;
case IGMPV3_HOST_MEMBERSHIP_REPORT:
err = br_ip4_multicast_igmp3_report(br, port, skb, vid);
Expand Down Expand Up @@ -1704,7 +1812,7 @@ static int br_multicast_ipv6_rcv(struct net_bridge *br,
src = eth_hdr(skb)->h_source;
BR_INPUT_SKB_CB(skb)->mrouters_only = 1;
err = br_ip6_multicast_add_group(br, port, &mld->mld_mca, vid,
src);
src, true);
break;
case ICMPV6_MLD2_REPORT:
err = br_ip6_multicast_mld2_report(br, port, skb, vid);
Expand Down Expand Up @@ -1779,6 +1887,31 @@ static void br_ip6_multicast_query_expired(struct timer_list *t)
}
#endif

static void __grp_src_gc(struct hlist_head *head)
{
struct net_bridge_group_src *ent;
struct hlist_node *tmp;

hlist_for_each_entry_safe(ent, tmp, head, del_node) {
hlist_del_init(&ent->del_node);
del_timer_sync(&ent->timer);
kfree_rcu(ent, rcu);
}
}

static void br_multicast_src_gc(struct work_struct *work)
{
struct net_bridge *br = container_of(work, struct net_bridge,
src_gc_work);
HLIST_HEAD(deleted_head);

spin_lock_bh(&br->multicast_lock);
hlist_move_list(&br->src_gc_list, &deleted_head);
spin_unlock_bh(&br->multicast_lock);

__grp_src_gc(&deleted_head);
}

void br_multicast_init(struct net_bridge *br)
{
br->hash_max = BR_MULTICAST_DEFAULT_HASH_MAX;
Expand Down Expand Up @@ -1819,6 +1952,8 @@ void br_multicast_init(struct net_bridge *br)
br_ip6_multicast_query_expired, 0);
#endif
INIT_HLIST_HEAD(&br->mdb_list);
INIT_HLIST_HEAD(&br->src_gc_list);
INIT_WORK(&br->src_gc_work, br_multicast_src_gc);
}

static void br_ip4_multicast_join_snoopers(struct net_bridge *br)
Expand Down Expand Up @@ -1922,6 +2057,7 @@ void br_multicast_stop(struct net_bridge *br)
void br_multicast_dev_del(struct net_bridge *br)
{
struct net_bridge_mdb_entry *mp;
HLIST_HEAD(deleted_head);
struct hlist_node *tmp;

spin_lock_bh(&br->multicast_lock);
Expand All @@ -1932,8 +2068,12 @@ void br_multicast_dev_del(struct net_bridge *br)
hlist_del_rcu(&mp->mdb_node);
kfree_rcu(mp, rcu);
}
hlist_move_list(&br->src_gc_list, &deleted_head);
spin_unlock_bh(&br->multicast_lock);

__grp_src_gc(&deleted_head);
cancel_work_sync(&br->src_gc_work);

rcu_barrier();
}

Expand Down
26 changes: 25 additions & 1 deletion net/bridge/br_private.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -214,13 +214,34 @@ struct net_bridge_fdb_entry {
#define MDB_PG_FLAGS_OFFLOAD BIT(1)
#define MDB_PG_FLAGS_FAST_LEAVE BIT(2)

#define PG_SRC_ENT_LIMIT 32

#define BR_SGRP_F_DELETE BIT(0)
#define BR_SGRP_F_SEND BIT(1)

struct net_bridge_group_src {
struct hlist_node node;

struct br_ip addr;
struct net_bridge_port_group *pg;
u8 flags;
struct timer_list timer;

struct net_bridge *br;
struct hlist_node del_node;
struct rcu_head rcu;
};

struct net_bridge_port_group {
struct net_bridge_port *port;
struct net_bridge_port_group __rcu *next;
struct br_ip addr;
unsigned char eth_addr[ETH_ALEN] __aligned(2);
unsigned char flags;
unsigned char filter_mode;

struct hlist_head src_list;
unsigned int src_ents;
struct timer_list timer;
struct hlist_node mglist;

Expand Down Expand Up @@ -410,6 +431,7 @@ struct net_bridge {

struct rhashtable mdb_hash_tbl;

struct hlist_head src_gc_list;
struct hlist_head mdb_list;
struct hlist_head router_list;

Expand All @@ -423,6 +445,7 @@ struct net_bridge {
struct bridge_mcast_own_query ip6_own_query;
struct bridge_mcast_querier ip6_querier;
#endif /* IS_ENABLED(CONFIG_IPV6) */
struct work_struct src_gc_work;
#endif

struct timer_list hello_timer;
Expand Down Expand Up @@ -770,7 +793,8 @@ br_multicast_new_group(struct net_bridge *br, struct br_ip *group);
struct net_bridge_port_group *
br_multicast_new_port_group(struct net_bridge_port *port, struct br_ip *group,
struct net_bridge_port_group __rcu *next,
unsigned char flags, const unsigned char *src);
unsigned char flags, const unsigned char *src,
u8 filter_mode);
int br_mdb_hash_init(struct net_bridge *br);
void br_mdb_hash_fini(struct net_bridge *br);
void br_mdb_notify(struct net_device *dev, struct net_bridge_port *port,
Expand Down

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