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multicast.c
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multicast.c
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// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) B.A.T.M.A.N. contributors:
*
* Linus Lüssing
*/
#include "multicast.h"
#include "main.h"
#include <linux/atomic.h>
#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/byteorder/generic.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/gfp.h>
#include <linux/icmpv6.h>
#include <linux/if_bridge.h>
#include <linux/if_ether.h>
#include <linux/igmp.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/inetdevice.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/netdevice.h>
#include <linux/netlink.h>
#include <linux/printk.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <net/addrconf.h>
#include <net/genetlink.h>
#include <net/if_inet6.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/netlink.h>
#include <net/sock.h>
#include <uapi/linux/batadv_packet.h>
#include <uapi/linux/batman_adv.h>
#include "bridge_loop_avoidance.h"
#include "hard-interface.h"
#include "hash.h"
#include "log.h"
#include "netlink.h"
#include "send.h"
#include "soft-interface.h"
#include "translation-table.h"
#include "tvlv.h"
static void batadv_mcast_mla_update(struct work_struct *work);
/**
* batadv_mcast_start_timer() - schedule the multicast periodic worker
* @bat_priv: the bat priv with all the soft interface information
*/
static void batadv_mcast_start_timer(struct batadv_priv *bat_priv)
{
queue_delayed_work(batadv_event_workqueue, &bat_priv->mcast.work,
msecs_to_jiffies(BATADV_MCAST_WORK_PERIOD));
}
/**
* batadv_mcast_get_bridge() - get the bridge on top of the softif if it exists
* @soft_iface: netdev struct of the mesh interface
*
* If the given soft interface has a bridge on top then the refcount
* of the according net device is increased.
*
* Return: NULL if no such bridge exists. Otherwise the net device of the
* bridge.
*/
static struct net_device *batadv_mcast_get_bridge(struct net_device *soft_iface)
{
struct net_device *upper = soft_iface;
rcu_read_lock();
do {
upper = netdev_master_upper_dev_get_rcu(upper);
} while (upper && !(upper->priv_flags & IFF_EBRIDGE));
if (upper)
dev_hold(upper);
rcu_read_unlock();
return upper;
}
/**
* batadv_mcast_mla_rtr_flags_softif_get_ipv4() - get mcast router flags from
* node for IPv4
* @dev: the interface to check
*
* Checks the presence of an IPv4 multicast router on this node.
*
* Caller needs to hold rcu read lock.
*
* Return: BATADV_NO_FLAGS if present, BATADV_MCAST_WANT_NO_RTR4 otherwise.
*/
static u8 batadv_mcast_mla_rtr_flags_softif_get_ipv4(struct net_device *dev)
{
struct in_device *in_dev = __in_dev_get_rcu(dev);
if (in_dev && IN_DEV_MFORWARD(in_dev))
return BATADV_NO_FLAGS;
else
return BATADV_MCAST_WANT_NO_RTR4;
}
/**
* batadv_mcast_mla_rtr_flags_softif_get_ipv6() - get mcast router flags from
* node for IPv6
* @dev: the interface to check
*
* Checks the presence of an IPv6 multicast router on this node.
*
* Caller needs to hold rcu read lock.
*
* Return: BATADV_NO_FLAGS if present, BATADV_MCAST_WANT_NO_RTR6 otherwise.
*/
#if IS_ENABLED(CONFIG_IPV6_MROUTE)
static u8 batadv_mcast_mla_rtr_flags_softif_get_ipv6(struct net_device *dev)
{
struct inet6_dev *in6_dev = __in6_dev_get(dev);
if (in6_dev && in6_dev->cnf.mc_forwarding)
return BATADV_NO_FLAGS;
else
return BATADV_MCAST_WANT_NO_RTR6;
}
#else
static inline u8
batadv_mcast_mla_rtr_flags_softif_get_ipv6(struct net_device *dev)
{
return BATADV_MCAST_WANT_NO_RTR6;
}
#endif
/**
* batadv_mcast_mla_rtr_flags_softif_get() - get mcast router flags from node
* @bat_priv: the bat priv with all the soft interface information
* @bridge: bridge interface on top of the soft_iface if present,
* otherwise pass NULL
*
* Checks the presence of IPv4 and IPv6 multicast routers on this
* node.
*
* Return:
* BATADV_NO_FLAGS: Both an IPv4 and IPv6 multicast router is present
* BATADV_MCAST_WANT_NO_RTR4: No IPv4 multicast router is present
* BATADV_MCAST_WANT_NO_RTR6: No IPv6 multicast router is present
* The former two OR'd: no multicast router is present
*/
static u8 batadv_mcast_mla_rtr_flags_softif_get(struct batadv_priv *bat_priv,
struct net_device *bridge)
{
struct net_device *dev = bridge ? bridge : bat_priv->soft_iface;
u8 flags = BATADV_NO_FLAGS;
rcu_read_lock();
flags |= batadv_mcast_mla_rtr_flags_softif_get_ipv4(dev);
flags |= batadv_mcast_mla_rtr_flags_softif_get_ipv6(dev);
rcu_read_unlock();
return flags;
}
/**
* batadv_mcast_mla_rtr_flags_bridge_get() - get mcast router flags from bridge
* @bat_priv: the bat priv with all the soft interface information
* @bridge: bridge interface on top of the soft_iface if present,
* otherwise pass NULL
*
* Checks the presence of IPv4 and IPv6 multicast routers behind a bridge.
*
* Return:
* BATADV_NO_FLAGS: Both an IPv4 and IPv6 multicast router is present
* BATADV_MCAST_WANT_NO_RTR4: No IPv4 multicast router is present
* BATADV_MCAST_WANT_NO_RTR6: No IPv6 multicast router is present
* The former two OR'd: no multicast router is present
*/
#if IS_ENABLED(CONFIG_IPV6)
static u8 batadv_mcast_mla_rtr_flags_bridge_get(struct batadv_priv *bat_priv,
struct net_device *bridge)
{
struct list_head bridge_mcast_list = LIST_HEAD_INIT(bridge_mcast_list);
struct net_device *dev = bat_priv->soft_iface;
struct br_ip_list *br_ip_entry, *tmp;
u8 flags = BATADV_MCAST_WANT_NO_RTR6;
int ret;
if (!bridge)
return BATADV_MCAST_WANT_NO_RTR4 | BATADV_MCAST_WANT_NO_RTR6;
/* TODO: ask the bridge if a multicast router is present (the bridge
* is capable of performing proper RFC4286 multicast router
* discovery) instead of searching for a ff02::2 listener here
*/
ret = br_multicast_list_adjacent(dev, &bridge_mcast_list);
if (ret < 0)
return BATADV_NO_FLAGS;
list_for_each_entry_safe(br_ip_entry, tmp, &bridge_mcast_list, list) {
/* the bridge snooping does not maintain IPv4 link-local
* addresses - therefore we won't find any IPv4 multicast router
* address here, only IPv6 ones
*/
if (br_ip_entry->addr.proto == htons(ETH_P_IPV6) &&
ipv6_addr_is_ll_all_routers(&br_ip_entry->addr.dst.ip6))
flags &= ~BATADV_MCAST_WANT_NO_RTR6;
list_del(&br_ip_entry->list);
kfree(br_ip_entry);
}
return flags;
}
#else
static inline u8
batadv_mcast_mla_rtr_flags_bridge_get(struct batadv_priv *bat_priv,
struct net_device *bridge)
{
if (bridge)
return BATADV_NO_FLAGS;
else
return BATADV_MCAST_WANT_NO_RTR4 | BATADV_MCAST_WANT_NO_RTR6;
}
#endif
/**
* batadv_mcast_mla_rtr_flags_get() - get multicast router flags
* @bat_priv: the bat priv with all the soft interface information
* @bridge: bridge interface on top of the soft_iface if present,
* otherwise pass NULL
*
* Checks the presence of IPv4 and IPv6 multicast routers on this
* node or behind its bridge.
*
* Return:
* BATADV_NO_FLAGS: Both an IPv4 and IPv6 multicast router is present
* BATADV_MCAST_WANT_NO_RTR4: No IPv4 multicast router is present
* BATADV_MCAST_WANT_NO_RTR6: No IPv6 multicast router is present
* The former two OR'd: no multicast router is present
*/
static u8 batadv_mcast_mla_rtr_flags_get(struct batadv_priv *bat_priv,
struct net_device *bridge)
{
u8 flags = BATADV_MCAST_WANT_NO_RTR4 | BATADV_MCAST_WANT_NO_RTR6;
flags &= batadv_mcast_mla_rtr_flags_softif_get(bat_priv, bridge);
flags &= batadv_mcast_mla_rtr_flags_bridge_get(bat_priv, bridge);
return flags;
}
/**
* batadv_mcast_mla_flags_get() - get the new multicast flags
* @bat_priv: the bat priv with all the soft interface information
*
* Return: A set of flags for the current/next TVLV, querier and
* bridge state.
*/
static struct batadv_mcast_mla_flags
batadv_mcast_mla_flags_get(struct batadv_priv *bat_priv)
{
struct net_device *dev = bat_priv->soft_iface;
struct batadv_mcast_querier_state *qr4, *qr6;
struct batadv_mcast_mla_flags mla_flags;
struct net_device *bridge;
bridge = batadv_mcast_get_bridge(dev);
memset(&mla_flags, 0, sizeof(mla_flags));
mla_flags.enabled = 1;
mla_flags.tvlv_flags |= batadv_mcast_mla_rtr_flags_get(bat_priv,
bridge);
if (!bridge)
return mla_flags;
dev_put(bridge);
mla_flags.bridged = 1;
qr4 = &mla_flags.querier_ipv4;
qr6 = &mla_flags.querier_ipv6;
if (!IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING))
pr_warn_once("No bridge IGMP snooping compiled - multicast optimizations disabled\n");
qr4->exists = br_multicast_has_querier_anywhere(dev, ETH_P_IP);
qr4->shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IP);
qr6->exists = br_multicast_has_querier_anywhere(dev, ETH_P_IPV6);
qr6->shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IPV6);
mla_flags.tvlv_flags |= BATADV_MCAST_WANT_ALL_UNSNOOPABLES;
/* 1) If no querier exists at all, then multicast listeners on
* our local TT clients behind the bridge will keep silent.
* 2) If the selected querier is on one of our local TT clients,
* behind the bridge, then this querier might shadow multicast
* listeners on our local TT clients, behind this bridge.
*
* In both cases, we will signalize other batman nodes that
* we need all multicast traffic of the according protocol.
*/
if (!qr4->exists || qr4->shadowing) {
mla_flags.tvlv_flags |= BATADV_MCAST_WANT_ALL_IPV4;
mla_flags.tvlv_flags &= ~BATADV_MCAST_WANT_NO_RTR4;
}
if (!qr6->exists || qr6->shadowing) {
mla_flags.tvlv_flags |= BATADV_MCAST_WANT_ALL_IPV6;
mla_flags.tvlv_flags &= ~BATADV_MCAST_WANT_NO_RTR6;
}
return mla_flags;
}
/**
* batadv_mcast_mla_is_duplicate() - check whether an address is in a list
* @mcast_addr: the multicast address to check
* @mcast_list: the list with multicast addresses to search in
*
* Return: true if the given address is already in the given list.
* Otherwise returns false.
*/
static bool batadv_mcast_mla_is_duplicate(u8 *mcast_addr,
struct hlist_head *mcast_list)
{
struct batadv_hw_addr *mcast_entry;
hlist_for_each_entry(mcast_entry, mcast_list, list)
if (batadv_compare_eth(mcast_entry->addr, mcast_addr))
return true;
return false;
}
/**
* batadv_mcast_mla_softif_get_ipv4() - get softif IPv4 multicast listeners
* @dev: the device to collect multicast addresses from
* @mcast_list: a list to put found addresses into
* @flags: flags indicating the new multicast state
*
* Collects multicast addresses of IPv4 multicast listeners residing
* on this kernel on the given soft interface, dev, in
* the given mcast_list. In general, multicast listeners provided by
* your multicast receiving applications run directly on this node.
*
* Return: -ENOMEM on memory allocation error or the number of
* items added to the mcast_list otherwise.
*/
static int
batadv_mcast_mla_softif_get_ipv4(struct net_device *dev,
struct hlist_head *mcast_list,
struct batadv_mcast_mla_flags *flags)
{
struct batadv_hw_addr *new;
struct in_device *in_dev;
u8 mcast_addr[ETH_ALEN];
struct ip_mc_list *pmc;
int ret = 0;
if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4)
return 0;
rcu_read_lock();
in_dev = __in_dev_get_rcu(dev);
if (!in_dev) {
rcu_read_unlock();
return 0;
}
for (pmc = rcu_dereference(in_dev->mc_list); pmc;
pmc = rcu_dereference(pmc->next_rcu)) {
if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES &&
ipv4_is_local_multicast(pmc->multiaddr))
continue;
if (!(flags->tvlv_flags & BATADV_MCAST_WANT_NO_RTR4) &&
!ipv4_is_local_multicast(pmc->multiaddr))
continue;
ip_eth_mc_map(pmc->multiaddr, mcast_addr);
if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list))
continue;
new = kmalloc(sizeof(*new), GFP_ATOMIC);
if (!new) {
ret = -ENOMEM;
break;
}
ether_addr_copy(new->addr, mcast_addr);
hlist_add_head(&new->list, mcast_list);
ret++;
}
rcu_read_unlock();
return ret;
}
/**
* batadv_mcast_mla_softif_get_ipv6() - get softif IPv6 multicast listeners
* @dev: the device to collect multicast addresses from
* @mcast_list: a list to put found addresses into
* @flags: flags indicating the new multicast state
*
* Collects multicast addresses of IPv6 multicast listeners residing
* on this kernel on the given soft interface, dev, in
* the given mcast_list. In general, multicast listeners provided by
* your multicast receiving applications run directly on this node.
*
* Return: -ENOMEM on memory allocation error or the number of
* items added to the mcast_list otherwise.
*/
#if IS_ENABLED(CONFIG_IPV6)
static int
batadv_mcast_mla_softif_get_ipv6(struct net_device *dev,
struct hlist_head *mcast_list,
struct batadv_mcast_mla_flags *flags)
{
struct batadv_hw_addr *new;
struct inet6_dev *in6_dev;
u8 mcast_addr[ETH_ALEN];
struct ifmcaddr6 *pmc6;
int ret = 0;
if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6)
return 0;
rcu_read_lock();
in6_dev = __in6_dev_get(dev);
if (!in6_dev) {
rcu_read_unlock();
return 0;
}
for (pmc6 = rcu_dereference(in6_dev->mc_list);
pmc6;
pmc6 = rcu_dereference(pmc6->next)) {
if (IPV6_ADDR_MC_SCOPE(&pmc6->mca_addr) <
IPV6_ADDR_SCOPE_LINKLOCAL)
continue;
if (flags->tvlv_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES &&
ipv6_addr_is_ll_all_nodes(&pmc6->mca_addr))
continue;
if (!(flags->tvlv_flags & BATADV_MCAST_WANT_NO_RTR6) &&
IPV6_ADDR_MC_SCOPE(&pmc6->mca_addr) >
IPV6_ADDR_SCOPE_LINKLOCAL)
continue;
ipv6_eth_mc_map(&pmc6->mca_addr, mcast_addr);
if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list))
continue;
new = kmalloc(sizeof(*new), GFP_ATOMIC);
if (!new) {
ret = -ENOMEM;
break;
}
ether_addr_copy(new->addr, mcast_addr);
hlist_add_head(&new->list, mcast_list);
ret++;
}
rcu_read_unlock();
return ret;
}
#else
static inline int
batadv_mcast_mla_softif_get_ipv6(struct net_device *dev,
struct hlist_head *mcast_list,
struct batadv_mcast_mla_flags *flags)
{
return 0;
}
#endif
/**
* batadv_mcast_mla_softif_get() - get softif multicast listeners
* @dev: the device to collect multicast addresses from
* @mcast_list: a list to put found addresses into
* @flags: flags indicating the new multicast state
*
* Collects multicast addresses of multicast listeners residing
* on this kernel on the given soft interface, dev, in
* the given mcast_list. In general, multicast listeners provided by
* your multicast receiving applications run directly on this node.
*
* If there is a bridge interface on top of dev, collect from that one
* instead. Just like with IP addresses and routes, multicast listeners
* will(/should) register to the bridge interface instead of an
* enslaved bat0.
*
* Return: -ENOMEM on memory allocation error or the number of
* items added to the mcast_list otherwise.
*/
static int
batadv_mcast_mla_softif_get(struct net_device *dev,
struct hlist_head *mcast_list,
struct batadv_mcast_mla_flags *flags)
{
struct net_device *bridge = batadv_mcast_get_bridge(dev);
int ret4, ret6 = 0;
if (bridge)
dev = bridge;
ret4 = batadv_mcast_mla_softif_get_ipv4(dev, mcast_list, flags);
if (ret4 < 0)
goto out;
ret6 = batadv_mcast_mla_softif_get_ipv6(dev, mcast_list, flags);
if (ret6 < 0) {
ret4 = 0;
goto out;
}
out:
if (bridge)
dev_put(bridge);
return ret4 + ret6;
}
/**
* batadv_mcast_mla_br_addr_cpy() - copy a bridge multicast address
* @dst: destination to write to - a multicast MAC address
* @src: source to read from - a multicast IP address
*
* Converts a given multicast IPv4/IPv6 address from a bridge
* to its matching multicast MAC address and copies it into the given
* destination buffer.
*
* Caller needs to make sure the destination buffer can hold
* at least ETH_ALEN bytes.
*/
static void batadv_mcast_mla_br_addr_cpy(char *dst, const struct br_ip *src)
{
if (src->proto == htons(ETH_P_IP))
ip_eth_mc_map(src->dst.ip4, dst);
#if IS_ENABLED(CONFIG_IPV6)
else if (src->proto == htons(ETH_P_IPV6))
ipv6_eth_mc_map(&src->dst.ip6, dst);
#endif
else
eth_zero_addr(dst);
}
/**
* batadv_mcast_mla_bridge_get() - get bridged-in multicast listeners
* @dev: a bridge slave whose bridge to collect multicast addresses from
* @mcast_list: a list to put found addresses into
* @flags: flags indicating the new multicast state
*
* Collects multicast addresses of multicast listeners residing
* on foreign, non-mesh devices which we gave access to our mesh via
* a bridge on top of the given soft interface, dev, in the given
* mcast_list.
*
* Return: -ENOMEM on memory allocation error or the number of
* items added to the mcast_list otherwise.
*/
static int batadv_mcast_mla_bridge_get(struct net_device *dev,
struct hlist_head *mcast_list,
struct batadv_mcast_mla_flags *flags)
{
struct list_head bridge_mcast_list = LIST_HEAD_INIT(bridge_mcast_list);
struct br_ip_list *br_ip_entry, *tmp;
u8 tvlv_flags = flags->tvlv_flags;
struct batadv_hw_addr *new;
u8 mcast_addr[ETH_ALEN];
int ret;
/* we don't need to detect these devices/listeners, the IGMP/MLD
* snooping code of the Linux bridge already does that for us
*/
ret = br_multicast_list_adjacent(dev, &bridge_mcast_list);
if (ret < 0)
goto out;
list_for_each_entry(br_ip_entry, &bridge_mcast_list, list) {
if (br_ip_entry->addr.proto == htons(ETH_P_IP)) {
if (tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4)
continue;
if (tvlv_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES &&
ipv4_is_local_multicast(br_ip_entry->addr.dst.ip4))
continue;
if (!(tvlv_flags & BATADV_MCAST_WANT_NO_RTR4) &&
!ipv4_is_local_multicast(br_ip_entry->addr.dst.ip4))
continue;
}
#if IS_ENABLED(CONFIG_IPV6)
if (br_ip_entry->addr.proto == htons(ETH_P_IPV6)) {
if (tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6)
continue;
if (tvlv_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES &&
ipv6_addr_is_ll_all_nodes(&br_ip_entry->addr.dst.ip6))
continue;
if (!(tvlv_flags & BATADV_MCAST_WANT_NO_RTR6) &&
IPV6_ADDR_MC_SCOPE(&br_ip_entry->addr.dst.ip6) >
IPV6_ADDR_SCOPE_LINKLOCAL)
continue;
}
#endif
batadv_mcast_mla_br_addr_cpy(mcast_addr, &br_ip_entry->addr);
if (batadv_mcast_mla_is_duplicate(mcast_addr, mcast_list))
continue;
new = kmalloc(sizeof(*new), GFP_ATOMIC);
if (!new) {
ret = -ENOMEM;
break;
}
ether_addr_copy(new->addr, mcast_addr);
hlist_add_head(&new->list, mcast_list);
}
out:
list_for_each_entry_safe(br_ip_entry, tmp, &bridge_mcast_list, list) {
list_del(&br_ip_entry->list);
kfree(br_ip_entry);
}
return ret;
}
/**
* batadv_mcast_mla_list_free() - free a list of multicast addresses
* @mcast_list: the list to free
*
* Removes and frees all items in the given mcast_list.
*/
static void batadv_mcast_mla_list_free(struct hlist_head *mcast_list)
{
struct batadv_hw_addr *mcast_entry;
struct hlist_node *tmp;
hlist_for_each_entry_safe(mcast_entry, tmp, mcast_list, list) {
hlist_del(&mcast_entry->list);
kfree(mcast_entry);
}
}
/**
* batadv_mcast_mla_tt_retract() - clean up multicast listener announcements
* @bat_priv: the bat priv with all the soft interface information
* @mcast_list: a list of addresses which should _not_ be removed
*
* Retracts the announcement of any multicast listener from the
* translation table except the ones listed in the given mcast_list.
*
* If mcast_list is NULL then all are retracted.
*/
static void batadv_mcast_mla_tt_retract(struct batadv_priv *bat_priv,
struct hlist_head *mcast_list)
{
struct batadv_hw_addr *mcast_entry;
struct hlist_node *tmp;
hlist_for_each_entry_safe(mcast_entry, tmp, &bat_priv->mcast.mla_list,
list) {
if (mcast_list &&
batadv_mcast_mla_is_duplicate(mcast_entry->addr,
mcast_list))
continue;
batadv_tt_local_remove(bat_priv, mcast_entry->addr,
BATADV_NO_FLAGS,
"mcast TT outdated", false);
hlist_del(&mcast_entry->list);
kfree(mcast_entry);
}
}
/**
* batadv_mcast_mla_tt_add() - add multicast listener announcements
* @bat_priv: the bat priv with all the soft interface information
* @mcast_list: a list of addresses which are going to get added
*
* Adds multicast listener announcements from the given mcast_list to the
* translation table if they have not been added yet.
*/
static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv,
struct hlist_head *mcast_list)
{
struct batadv_hw_addr *mcast_entry;
struct hlist_node *tmp;
if (!mcast_list)
return;
hlist_for_each_entry_safe(mcast_entry, tmp, mcast_list, list) {
if (batadv_mcast_mla_is_duplicate(mcast_entry->addr,
&bat_priv->mcast.mla_list))
continue;
if (!batadv_tt_local_add(bat_priv->soft_iface,
mcast_entry->addr, BATADV_NO_FLAGS,
BATADV_NULL_IFINDEX, BATADV_NO_MARK))
continue;
hlist_del(&mcast_entry->list);
hlist_add_head(&mcast_entry->list, &bat_priv->mcast.mla_list);
}
}
/**
* batadv_mcast_querier_log() - debug output regarding the querier status on
* link
* @bat_priv: the bat priv with all the soft interface information
* @str_proto: a string for the querier protocol (e.g. "IGMP" or "MLD")
* @old_state: the previous querier state on our link
* @new_state: the new querier state on our link
*
* Outputs debug messages to the logging facility with log level 'mcast'
* regarding changes to the querier status on the link which are relevant
* to our multicast optimizations.
*
* Usually this is about whether a querier appeared or vanished in
* our mesh or whether the querier is in the suboptimal position of being
* behind our local bridge segment: Snooping switches will directly
* forward listener reports to the querier, therefore batman-adv and
* the bridge will potentially not see these listeners - the querier is
* potentially shadowing listeners from us then.
*
* This is only interesting for nodes with a bridge on top of their
* soft interface.
*/
static void
batadv_mcast_querier_log(struct batadv_priv *bat_priv, char *str_proto,
struct batadv_mcast_querier_state *old_state,
struct batadv_mcast_querier_state *new_state)
{
if (!old_state->exists && new_state->exists)
batadv_info(bat_priv->soft_iface, "%s Querier appeared\n",
str_proto);
else if (old_state->exists && !new_state->exists)
batadv_info(bat_priv->soft_iface,
"%s Querier disappeared - multicast optimizations disabled\n",
str_proto);
else if (!bat_priv->mcast.mla_flags.bridged && !new_state->exists)
batadv_info(bat_priv->soft_iface,
"No %s Querier present - multicast optimizations disabled\n",
str_proto);
if (new_state->exists) {
if ((!old_state->shadowing && new_state->shadowing) ||
(!old_state->exists && new_state->shadowing))
batadv_dbg(BATADV_DBG_MCAST, bat_priv,
"%s Querier is behind our bridged segment: Might shadow listeners\n",
str_proto);
else if (old_state->shadowing && !new_state->shadowing)
batadv_dbg(BATADV_DBG_MCAST, bat_priv,
"%s Querier is not behind our bridged segment\n",
str_proto);
}
}
/**
* batadv_mcast_bridge_log() - debug output for topology changes in bridged
* setups
* @bat_priv: the bat priv with all the soft interface information
* @new_flags: flags indicating the new multicast state
*
* If no bridges are ever used on this node, then this function does nothing.
*
* Otherwise this function outputs debug information to the 'mcast' log level
* which might be relevant to our multicast optimizations.
*
* More precisely, it outputs information when a bridge interface is added or
* removed from a soft interface. And when a bridge is present, it further
* outputs information about the querier state which is relevant for the
* multicast flags this node is going to set.
*/
static void
batadv_mcast_bridge_log(struct batadv_priv *bat_priv,
struct batadv_mcast_mla_flags *new_flags)
{
struct batadv_mcast_mla_flags *old_flags = &bat_priv->mcast.mla_flags;
if (!old_flags->bridged && new_flags->bridged)
batadv_dbg(BATADV_DBG_MCAST, bat_priv,
"Bridge added: Setting Unsnoopables(U)-flag\n");
else if (old_flags->bridged && !new_flags->bridged)
batadv_dbg(BATADV_DBG_MCAST, bat_priv,
"Bridge removed: Unsetting Unsnoopables(U)-flag\n");
if (new_flags->bridged) {
batadv_mcast_querier_log(bat_priv, "IGMP",
&old_flags->querier_ipv4,
&new_flags->querier_ipv4);
batadv_mcast_querier_log(bat_priv, "MLD",
&old_flags->querier_ipv6,
&new_flags->querier_ipv6);
}
}
/**
* batadv_mcast_flags_log() - output debug information about mcast flag changes
* @bat_priv: the bat priv with all the soft interface information
* @flags: TVLV flags indicating the new multicast state
*
* Whenever the multicast TVLV flags this node announces change, this function
* should be used to notify userspace about the change.
*/
static void batadv_mcast_flags_log(struct batadv_priv *bat_priv, u8 flags)
{
bool old_enabled = bat_priv->mcast.mla_flags.enabled;
u8 old_flags = bat_priv->mcast.mla_flags.tvlv_flags;
char str_old_flags[] = "[.... . ]";
sprintf(str_old_flags, "[%c%c%c%s%s]",
(old_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.',
(old_flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.',
(old_flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.',
!(old_flags & BATADV_MCAST_WANT_NO_RTR4) ? "R4" : ". ",
!(old_flags & BATADV_MCAST_WANT_NO_RTR6) ? "R6" : ". ");
batadv_dbg(BATADV_DBG_MCAST, bat_priv,
"Changing multicast flags from '%s' to '[%c%c%c%s%s]'\n",
old_enabled ? str_old_flags : "<undefined>",
(flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.',
(flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.',
(flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.',
!(flags & BATADV_MCAST_WANT_NO_RTR4) ? "R4" : ". ",
!(flags & BATADV_MCAST_WANT_NO_RTR6) ? "R6" : ". ");
}
/**
* batadv_mcast_mla_flags_update() - update multicast flags
* @bat_priv: the bat priv with all the soft interface information
* @flags: flags indicating the new multicast state
*
* Updates the own multicast tvlv with our current multicast related settings,
* capabilities and inabilities.
*/
static void
batadv_mcast_mla_flags_update(struct batadv_priv *bat_priv,
struct batadv_mcast_mla_flags *flags)
{
struct batadv_tvlv_mcast_data mcast_data;
if (!memcmp(flags, &bat_priv->mcast.mla_flags, sizeof(*flags)))
return;
batadv_mcast_bridge_log(bat_priv, flags);
batadv_mcast_flags_log(bat_priv, flags->tvlv_flags);
mcast_data.flags = flags->tvlv_flags;
memset(mcast_data.reserved, 0, sizeof(mcast_data.reserved));
batadv_tvlv_container_register(bat_priv, BATADV_TVLV_MCAST, 2,
&mcast_data, sizeof(mcast_data));
bat_priv->mcast.mla_flags = *flags;
}
/**
* __batadv_mcast_mla_update() - update the own MLAs
* @bat_priv: the bat priv with all the soft interface information
*
* Updates the own multicast listener announcements in the translation
* table as well as the own, announced multicast tvlv container.
*
* Note that non-conflicting reads and writes to bat_priv->mcast.mla_list
* in batadv_mcast_mla_tt_retract() and batadv_mcast_mla_tt_add() are
* ensured by the non-parallel execution of the worker this function
* belongs to.
*/
static void __batadv_mcast_mla_update(struct batadv_priv *bat_priv)
{
struct net_device *soft_iface = bat_priv->soft_iface;
struct hlist_head mcast_list = HLIST_HEAD_INIT;
struct batadv_mcast_mla_flags flags;
int ret;
flags = batadv_mcast_mla_flags_get(bat_priv);
ret = batadv_mcast_mla_softif_get(soft_iface, &mcast_list, &flags);
if (ret < 0)
goto out;
ret = batadv_mcast_mla_bridge_get(soft_iface, &mcast_list, &flags);
if (ret < 0)
goto out;
spin_lock(&bat_priv->mcast.mla_lock);
batadv_mcast_mla_tt_retract(bat_priv, &mcast_list);
batadv_mcast_mla_tt_add(bat_priv, &mcast_list);
batadv_mcast_mla_flags_update(bat_priv, &flags);
spin_unlock(&bat_priv->mcast.mla_lock);
out:
batadv_mcast_mla_list_free(&mcast_list);
}
/**
* batadv_mcast_mla_update() - update the own MLAs
* @work: kernel work struct
*
* Updates the own multicast listener announcements in the translation
* table as well as the own, announced multicast tvlv container.
*
* In the end, reschedules the work timer.
*/
static void batadv_mcast_mla_update(struct work_struct *work)
{
struct delayed_work *delayed_work;
struct batadv_priv_mcast *priv_mcast;
struct batadv_priv *bat_priv;
delayed_work = to_delayed_work(work);
priv_mcast = container_of(delayed_work, struct batadv_priv_mcast, work);
bat_priv = container_of(priv_mcast, struct batadv_priv, mcast);
__batadv_mcast_mla_update(bat_priv);
batadv_mcast_start_timer(bat_priv);
}
/**
* batadv_mcast_is_report_ipv4() - check for IGMP reports
* @skb: the ethernet frame destined for the mesh
*
* This call might reallocate skb data.
*
* Checks whether the given frame is a valid IGMP report.
*
* Return: If so then true, otherwise false.
*/
static bool batadv_mcast_is_report_ipv4(struct sk_buff *skb)
{
if (ip_mc_check_igmp(skb) < 0)
return false;
switch (igmp_hdr(skb)->type) {
case IGMP_HOST_MEMBERSHIP_REPORT:
case IGMPV2_HOST_MEMBERSHIP_REPORT:
case IGMPV3_HOST_MEMBERSHIP_REPORT:
return true;
}
return false;
}
/**
* batadv_mcast_forw_mode_check_ipv4() - check for optimized forwarding
* potential
* @bat_priv: the bat priv with all the soft interface information
* @skb: the IPv4 packet to check
* @is_unsnoopable: stores whether the destination is snoopable
* @is_routable: stores whether the destination is routable
*
* Checks whether the given IPv4 packet has the potential to be forwarded with a
* mode more optimal than classic flooding.
*
* Return: If so then 0. Otherwise -EINVAL or -ENOMEM in case of memory
* allocation failure.
*/
static int batadv_mcast_forw_mode_check_ipv4(struct batadv_priv *bat_priv,
struct sk_buff *skb,
bool *is_unsnoopable,
int *is_routable)
{
struct iphdr *iphdr;
/* We might fail due to out-of-memory -> drop it */
if (!pskb_may_pull(skb, sizeof(struct ethhdr) + sizeof(*iphdr)))
return -ENOMEM;