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net: bridge: mcast: add support for group-and-source specific queries
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Allows br_multicast_alloc_query to build queries with the port group's
source lists and sends a query for sources over and under lmqt when
necessary as per RFCs 3376 and 3810 with the suppress flag set
appropriately.

v3: add IPv6 support

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 5205e91 commit 438ef2d
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Showing 2 changed files with 183 additions and 54 deletions.
236 changes: 182 additions & 54 deletions net/bridge/br_multicast.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -234,21 +234,50 @@ static void br_multicast_port_group_expired(struct timer_list *t)
}

static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
__be32 group,
u8 *igmp_type)
struct net_bridge_port_group *pg,
__be32 ip_dst, __be32 group,
bool with_srcs, bool over_lmqt,
u8 sflag, u8 *igmp_type)
{
struct net_bridge_port *p = pg ? pg->port : NULL;
struct net_bridge_group_src *ent;
size_t pkt_size, igmp_hdr_size;
unsigned long now = jiffies;
struct igmpv3_query *ihv3;
size_t igmp_hdr_size;
void *csum_start = NULL;
__sum16 *csum = NULL;
struct sk_buff *skb;
struct igmphdr *ih;
struct ethhdr *eth;
unsigned long lmqt;
struct iphdr *iph;
u16 lmqt_srcs = 0;

igmp_hdr_size = sizeof(*ih);
if (br->multicast_igmp_version == 3)
if (br->multicast_igmp_version == 3) {
igmp_hdr_size = sizeof(*ihv3);
skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*iph) +
igmp_hdr_size + 4);
if (pg && with_srcs) {
lmqt = now + (br->multicast_last_member_interval *
br->multicast_last_member_count);
hlist_for_each_entry(ent, &pg->src_list, node) {
if (over_lmqt == time_after(ent->timer.expires,
lmqt) &&
ent->src_query_rexmit_cnt > 0)
lmqt_srcs++;
}

if (!lmqt_srcs)
return NULL;
igmp_hdr_size += lmqt_srcs * sizeof(__be32);
}
}

pkt_size = sizeof(*eth) + sizeof(*iph) + 4 + igmp_hdr_size;
if ((p && pkt_size > p->dev->mtu) ||
pkt_size > br->dev->mtu)
return NULL;

skb = netdev_alloc_skb_ip_align(br->dev, pkt_size);
if (!skb)
goto out;

Expand All @@ -258,29 +287,24 @@ static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
eth = eth_hdr(skb);

ether_addr_copy(eth->h_source, br->dev->dev_addr);
eth->h_dest[0] = 1;
eth->h_dest[1] = 0;
eth->h_dest[2] = 0x5e;
eth->h_dest[3] = 0;
eth->h_dest[4] = 0;
eth->h_dest[5] = 1;
ip_eth_mc_map(ip_dst, eth->h_dest);
eth->h_proto = htons(ETH_P_IP);
skb_put(skb, sizeof(*eth));

skb_set_network_header(skb, skb->len);
iph = ip_hdr(skb);
iph->tot_len = htons(pkt_size - sizeof(*eth));

iph->version = 4;
iph->ihl = 6;
iph->tos = 0xc0;
iph->tot_len = htons(sizeof(*iph) + igmp_hdr_size + 4);
iph->id = 0;
iph->frag_off = htons(IP_DF);
iph->ttl = 1;
iph->protocol = IPPROTO_IGMP;
iph->saddr = br_opt_get(br, BROPT_MULTICAST_QUERY_USE_IFADDR) ?
inet_select_addr(br->dev, 0, RT_SCOPE_LINK) : 0;
iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
iph->daddr = ip_dst;
((u8 *)&iph[1])[0] = IPOPT_RA;
((u8 *)&iph[1])[1] = 4;
((u8 *)&iph[1])[2] = 0;
Expand All @@ -300,7 +324,8 @@ static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
(HZ / IGMP_TIMER_SCALE);
ih->group = group;
ih->csum = 0;
ih->csum = ip_compute_csum((void *)ih, sizeof(*ih));
csum = &ih->csum;
csum_start = (void *)ih;
break;
case 3:
ihv3 = igmpv3_query_hdr(skb);
Expand All @@ -310,15 +335,38 @@ static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,
(HZ / IGMP_TIMER_SCALE);
ihv3->group = group;
ihv3->qqic = br->multicast_query_interval / HZ;
ihv3->nsrcs = 0;
ihv3->nsrcs = htons(lmqt_srcs);
ihv3->resv = 0;
ihv3->suppress = 0;
ihv3->suppress = sflag;
ihv3->qrv = 2;
ihv3->csum = 0;
ihv3->csum = ip_compute_csum((void *)ihv3, sizeof(*ihv3));
csum = &ihv3->csum;
csum_start = (void *)ihv3;
if (!pg || !with_srcs)
break;

lmqt_srcs = 0;
hlist_for_each_entry(ent, &pg->src_list, node) {
if (over_lmqt == time_after(ent->timer.expires,
lmqt) &&
ent->src_query_rexmit_cnt > 0) {
ihv3->srcs[lmqt_srcs++] = ent->addr.u.ip4;
ent->src_query_rexmit_cnt--;
}
}
if (WARN_ON(lmqt_srcs != ntohs(ihv3->nsrcs))) {
kfree_skb(skb);
return NULL;
}
break;
}

if (WARN_ON(!csum || !csum_start)) {
kfree_skb(skb);
return NULL;
}

*csum = ip_compute_csum(csum_start, igmp_hdr_size);
skb_put(skb, igmp_hdr_size);
__skb_pull(skb, sizeof(*eth));

Expand All @@ -328,23 +376,53 @@ static struct sk_buff *br_ip4_multicast_alloc_query(struct net_bridge *br,

#if IS_ENABLED(CONFIG_IPV6)
static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
const struct in6_addr *grp,
u8 *igmp_type)
struct net_bridge_port_group *pg,
const struct in6_addr *ip6_dst,
const struct in6_addr *group,
bool with_srcs, bool over_llqt,
u8 sflag, u8 *igmp_type)
{
struct net_bridge_port *p = pg ? pg->port : NULL;
struct net_bridge_group_src *ent;
size_t pkt_size, mld_hdr_size;
unsigned long now = jiffies;
struct mld2_query *mld2q;
void *csum_start = NULL;
unsigned long interval;
__sum16 *csum = NULL;
struct ipv6hdr *ip6h;
struct mld_msg *mldq;
size_t mld_hdr_size;
struct sk_buff *skb;
unsigned long llqt;
struct ethhdr *eth;
u16 llqt_srcs = 0;
u8 *hopopt;

mld_hdr_size = sizeof(*mldq);
if (br->multicast_mld_version == 2)
if (br->multicast_mld_version == 2) {
mld_hdr_size = sizeof(*mld2q);
skb = netdev_alloc_skb_ip_align(br->dev, sizeof(*eth) + sizeof(*ip6h) +
8 + mld_hdr_size);
if (pg && with_srcs) {
llqt = now + (br->multicast_last_member_interval *
br->multicast_last_member_count);
hlist_for_each_entry(ent, &pg->src_list, node) {
if (over_llqt == time_after(ent->timer.expires,
llqt) &&
ent->src_query_rexmit_cnt > 0)
llqt_srcs++;
}

if (!llqt_srcs)
return NULL;
mld_hdr_size += llqt_srcs * sizeof(struct in6_addr);
}
}

pkt_size = sizeof(*eth) + sizeof(*ip6h) + 8 + mld_hdr_size;
if ((p && pkt_size > p->dev->mtu) ||
pkt_size > br->dev->mtu)
return NULL;

skb = netdev_alloc_skb_ip_align(br->dev, pkt_size);
if (!skb)
goto out;

Expand All @@ -366,7 +444,7 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
ip6h->payload_len = htons(8 + mld_hdr_size);
ip6h->nexthdr = IPPROTO_HOPOPTS;
ip6h->hop_limit = 1;
ipv6_addr_set(&ip6h->daddr, htonl(0xff020000), 0, 0, htonl(1));
ip6h->daddr = *ip6_dst;
if (ipv6_dev_get_saddr(dev_net(br->dev), br->dev, &ip6h->daddr, 0,
&ip6h->saddr)) {
kfree_skb(skb);
Expand All @@ -391,7 +469,7 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,

/* ICMPv6 */
skb_set_transport_header(skb, skb->len);
interval = ipv6_addr_any(grp) ?
interval = ipv6_addr_any(group) ?
br->multicast_query_response_interval :
br->multicast_last_member_interval;
*igmp_type = ICMPV6_MGM_QUERY;
Expand All @@ -403,12 +481,9 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
mldq->mld_cksum = 0;
mldq->mld_maxdelay = htons((u16)jiffies_to_msecs(interval));
mldq->mld_reserved = 0;
mldq->mld_mca = *grp;
mldq->mld_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
sizeof(*mldq), IPPROTO_ICMPV6,
csum_partial(mldq,
sizeof(*mldq),
0));
mldq->mld_mca = *group;
csum = &mldq->mld_cksum;
csum_start = (void *)mldq;
break;
case 2:
mld2q = (struct mld2_query *)icmp6_hdr(skb);
Expand All @@ -418,21 +493,41 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
mld2q->mld2q_cksum = 0;
mld2q->mld2q_resv1 = 0;
mld2q->mld2q_resv2 = 0;
mld2q->mld2q_suppress = 0;
mld2q->mld2q_suppress = sflag;
mld2q->mld2q_qrv = 2;
mld2q->mld2q_nsrcs = 0;
mld2q->mld2q_nsrcs = htons(llqt_srcs);
mld2q->mld2q_qqic = br->multicast_query_interval / HZ;
mld2q->mld2q_mca = *grp;
mld2q->mld2q_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
sizeof(*mld2q),
IPPROTO_ICMPV6,
csum_partial(mld2q,
sizeof(*mld2q),
0));
mld2q->mld2q_mca = *group;
csum = &mld2q->mld2q_cksum;
csum_start = (void *)mld2q;
if (!pg || !with_srcs)
break;

llqt_srcs = 0;
hlist_for_each_entry(ent, &pg->src_list, node) {
if (over_llqt == time_after(ent->timer.expires,
llqt) &&
ent->src_query_rexmit_cnt > 0) {
mld2q->mld2q_srcs[llqt_srcs++] = ent->addr.u.ip6;
ent->src_query_rexmit_cnt--;
}
}
if (WARN_ON(llqt_srcs != ntohs(mld2q->mld2q_nsrcs))) {
kfree_skb(skb);
return NULL;
}
break;
}
skb_put(skb, mld_hdr_size);

if (WARN_ON(!csum || !csum_start)) {
kfree_skb(skb);
return NULL;
}

*csum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, mld_hdr_size,
IPPROTO_ICMPV6,
csum_partial(csum_start, mld_hdr_size, 0));
skb_put(skb, mld_hdr_size);
__skb_pull(skb, sizeof(*eth));

out:
Expand All @@ -441,16 +536,36 @@ static struct sk_buff *br_ip6_multicast_alloc_query(struct net_bridge *br,
#endif

static struct sk_buff *br_multicast_alloc_query(struct net_bridge *br,
struct br_ip *addr,
u8 *igmp_type)
struct net_bridge_port_group *pg,
struct br_ip *ip_dst,
struct br_ip *group,
bool with_srcs, bool over_lmqt,
u8 sflag, u8 *igmp_type)
{
switch (addr->proto) {
__be32 ip4_dst;

switch (group->proto) {
case htons(ETH_P_IP):
return br_ip4_multicast_alloc_query(br, addr->u.ip4, igmp_type);
ip4_dst = ip_dst ? ip_dst->u.ip4 : htonl(INADDR_ALLHOSTS_GROUP);
return br_ip4_multicast_alloc_query(br, pg,
ip4_dst, group->u.ip4,
with_srcs, over_lmqt,
sflag, igmp_type);
#if IS_ENABLED(CONFIG_IPV6)
case htons(ETH_P_IPV6):
return br_ip6_multicast_alloc_query(br, &addr->u.ip6,
igmp_type);
case htons(ETH_P_IPV6): {
struct in6_addr ip6_dst;

if (ip_dst)
ip6_dst = ip_dst->u.ip6;
else
ipv6_addr_set(&ip6_dst, htonl(0xff020000), 0, 0,
htonl(1));

return br_ip6_multicast_alloc_query(br, pg,
&ip6_dst, &group->u.ip6,
with_srcs, over_lmqt,
sflag, igmp_type);
}
#endif
}
return NULL;
Expand Down Expand Up @@ -824,12 +939,19 @@ static void br_multicast_select_own_querier(struct net_bridge *br,

static void __br_multicast_send_query(struct net_bridge *br,
struct net_bridge_port *port,
struct br_ip *ip)
struct net_bridge_port_group *pg,
struct br_ip *ip_dst,
struct br_ip *group,
bool with_srcs,
u8 sflag)
{
bool over_lmqt = !!sflag;
struct sk_buff *skb;
u8 igmp_type;

skb = br_multicast_alloc_query(br, ip, &igmp_type);
again_under_lmqt:
skb = br_multicast_alloc_query(br, pg, ip_dst, group, with_srcs,
over_lmqt, sflag, &igmp_type);
if (!skb)
return;

Expand All @@ -840,8 +962,13 @@ static void __br_multicast_send_query(struct net_bridge *br,
NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT,
dev_net(port->dev), NULL, skb, NULL, skb->dev,
br_dev_queue_push_xmit);

if (over_lmqt && with_srcs && sflag) {
over_lmqt = false;
goto again_under_lmqt;
}
} else {
br_multicast_select_own_querier(br, ip, skb);
br_multicast_select_own_querier(br, group, skb);
br_multicast_count(br, port, skb, igmp_type,
BR_MCAST_DIR_RX);
netif_rx(skb);
Expand Down Expand Up @@ -877,7 +1004,7 @@ static void br_multicast_send_query(struct net_bridge *br,
if (!other_query || timer_pending(&other_query->timer))
return;

__br_multicast_send_query(br, port, &br_group);
__br_multicast_send_query(br, port, NULL, NULL, &br_group, false, 0);

time = jiffies;
time += own_query->startup_sent < br->multicast_startup_query_count ?
Expand Down Expand Up @@ -1530,7 +1657,8 @@ br_multicast_leave_group(struct net_bridge *br,
goto out;

if (br_opt_get(br, BROPT_MULTICAST_QUERIER)) {
__br_multicast_send_query(br, port, &mp->addr);
__br_multicast_send_query(br, port, NULL, NULL, &mp->addr,
false, 0);

time = jiffies + br->multicast_last_member_count *
br->multicast_last_member_interval;
Expand Down
1 change: 1 addition & 0 deletions net/bridge/br_private.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -225,6 +225,7 @@ struct net_bridge_group_src {
struct br_ip addr;
struct net_bridge_port_group *pg;
u8 flags;
u8 src_query_rexmit_cnt;
struct timer_list timer;

struct net_bridge *br;
Expand Down

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