/* Copyright (C) 2014-2017 B.A.T.M.A.N. contributors: * * Linus Lüssing * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see <http://www.gnu.org/licenses/>. */ #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/fs.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/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/printk.h> #include <linux/rculist.h> #include <linux/rcupdate.h> #include <linux/seq_file.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/if_inet6.h> #include <net/ip.h> #include <net/ipv6.h> #include "hard-interface.h" #include "hash.h" #include "log.h" #include "packet.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_softif_get - get softif multicast listeners * @dev: the device to collect multicast addresses from * @mcast_list: a list to put found addresses into * * 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, collects 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 net_device *bridge = batadv_mcast_get_bridge(dev); struct netdev_hw_addr *mc_list_entry; struct batadv_hw_addr *new; int ret = 0; netif_addr_lock_bh(bridge ? bridge : dev); netdev_for_each_mc_addr(mc_list_entry, bridge ? bridge : dev) { new = kmalloc(sizeof(*new), GFP_ATOMIC); if (!new) { ret = -ENOMEM; break; } ether_addr_copy(new->addr, mc_list_entry->addr); hlist_add_head(&new->list, mcast_list); ret++; } netif_addr_unlock_bh(bridge ? bridge : dev); if (bridge) dev_put(bridge); return ret; } /** * 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_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->u.ip4, dst); #if IS_ENABLED(CONFIG_IPV6) else if (src->proto == htons(ETH_P_IPV6)) ipv6_eth_mc_map(&src->u.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 * * 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 list_head bridge_mcast_list = LIST_HEAD_INIT(bridge_mcast_list); struct br_ip_list *br_ip_entry, *tmp; 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) { 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. * * Do not call outside of the mcast worker! (or cancel mcast worker first) */ 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; WARN_ON(delayed_work_pending(&bat_priv->mcast.work)); 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. * * Do not call outside of the mcast worker! (or cancel mcast worker first) */ 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; WARN_ON(delayed_work_pending(&bat_priv->mcast.work)); 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_has_bridge - check whether the soft-iface is bridged * @bat_priv: the bat priv with all the soft interface information * * Checks whether there is a bridge on top of our soft interface. * * Return: true if there is a bridge, false otherwise. */ static bool batadv_mcast_has_bridge(struct batadv_priv *bat_priv) { struct net_device *upper = bat_priv->soft_iface; rcu_read_lock(); do { upper = netdev_master_upper_dev_get_rcu(upper); } while (upper && !(upper->priv_flags & IFF_EBRIDGE)); rcu_read_unlock(); return upper; } /** * 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.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 * @bridged: a flag about whether the soft interface is currently bridged or not * @querier_ipv4: (maybe) new status of a potential, selected IGMP querier * @querier_ipv6: (maybe) new status of a potential, selected MLD querier * * 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, bool bridged, struct batadv_mcast_querier_state *querier_ipv4, struct batadv_mcast_querier_state *querier_ipv6) { if (!bat_priv->mcast.bridged && bridged) batadv_dbg(BATADV_DBG_MCAST, bat_priv, "Bridge added: Setting Unsnoopables(U)-flag\n"); else if (bat_priv->mcast.bridged && !bridged) batadv_dbg(BATADV_DBG_MCAST, bat_priv, "Bridge removed: Unsetting Unsnoopables(U)-flag\n"); if (bridged) { batadv_mcast_querier_log(bat_priv, "IGMP", &bat_priv->mcast.querier_ipv4, querier_ipv4); batadv_mcast_querier_log(bat_priv, "MLD", &bat_priv->mcast.querier_ipv6, querier_ipv6); } } /** * batadv_mcast_flags_logs - output debug information about mcast flag changes * @bat_priv: the bat priv with all the soft interface information * @flags: flags indicating the new multicast state * * Whenever the multicast flags this nodes announces changes (@mcast_flags vs. * bat_priv->mcast.flags), this notifies userspace via the 'mcast' log level. */ static void batadv_mcast_flags_log(struct batadv_priv *bat_priv, u8 flags) { u8 old_flags = bat_priv->mcast.flags; char str_old_flags[] = "[...]"; sprintf(str_old_flags, "[%c%c%c]", (old_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.', (old_flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.', (old_flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.'); batadv_dbg(BATADV_DBG_MCAST, bat_priv, "Changing multicast flags from '%s' to '[%c%c%c]'\n", bat_priv->mcast.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' : '.'); } /** * batadv_mcast_mla_tvlv_update - update multicast tvlv * @bat_priv: the bat priv with all the soft interface information * * Updates the own multicast tvlv with our current multicast related settings, * capabilities and inabilities. * * Return: false if we want all IPv4 && IPv6 multicast traffic and true * otherwise. */ static bool batadv_mcast_mla_tvlv_update(struct batadv_priv *bat_priv) { struct batadv_tvlv_mcast_data mcast_data; struct batadv_mcast_querier_state querier4 = {false, false}; struct batadv_mcast_querier_state querier6 = {false, false}; struct net_device *dev = bat_priv->soft_iface; bool bridged; mcast_data.flags = BATADV_NO_FLAGS; memset(mcast_data.reserved, 0, sizeof(mcast_data.reserved)); bridged = batadv_mcast_has_bridge(bat_priv); if (!bridged) goto update; #if !IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING) pr_warn_once("No bridge IGMP snooping compiled - multicast optimizations disabled\n"); #endif querier4.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IP); querier4.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IP); querier6.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IPV6); querier6.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IPV6); mcast_data.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 (!querier4.exists || querier4.shadowing) mcast_data.flags |= BATADV_MCAST_WANT_ALL_IPV4; if (!querier6.exists || querier6.shadowing) mcast_data.flags |= BATADV_MCAST_WANT_ALL_IPV6; update: batadv_mcast_bridge_log(bat_priv, bridged, &querier4, &querier6); bat_priv->mcast.querier_ipv4.exists = querier4.exists; bat_priv->mcast.querier_ipv4.shadowing = querier4.shadowing; bat_priv->mcast.querier_ipv6.exists = querier6.exists; bat_priv->mcast.querier_ipv6.shadowing = querier6.shadowing; bat_priv->mcast.bridged = bridged; if (!bat_priv->mcast.enabled || mcast_data.flags != bat_priv->mcast.flags) { batadv_mcast_flags_log(bat_priv, mcast_data.flags); batadv_tvlv_container_register(bat_priv, BATADV_TVLV_MCAST, 2, &mcast_data, sizeof(mcast_data)); bat_priv->mcast.flags = mcast_data.flags; bat_priv->mcast.enabled = true; } return !(mcast_data.flags & (BATADV_MCAST_WANT_ALL_IPV4 | BATADV_MCAST_WANT_ALL_IPV6)); } /** * __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; int ret; if (!batadv_mcast_mla_tvlv_update(bat_priv)) goto update; ret = batadv_mcast_mla_softif_get(soft_iface, &mcast_list); if (ret < 0) goto out; ret = batadv_mcast_mla_bridge_get(soft_iface, &mcast_list); if (ret < 0) goto out; update: batadv_mcast_mla_tt_retract(bat_priv, &mcast_list); batadv_mcast_mla_tt_add(bat_priv, &mcast_list); 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, NULL) < 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 * * 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) { 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; if (batadv_mcast_is_report_ipv4(skb)) return -EINVAL; iphdr = ip_hdr(skb); /* TODO: Implement Multicast Router Discovery (RFC4286), * then allow scope > link local, too */ if (!ipv4_is_local_multicast(iphdr->daddr)) return -EINVAL; /* link-local multicast listeners behind a bridge are * not snoopable (see RFC4541, section 2.1.2.2) */ *is_unsnoopable = true; return 0; } #if IS_ENABLED(CONFIG_IPV6) /** * batadv_mcast_is_report_ipv6 - check for MLD reports * @skb: the ethernet frame destined for the mesh * * This call might reallocate skb data. * * Checks whether the given frame is a valid MLD report. * * Return: If so then true, otherwise false. */ static bool batadv_mcast_is_report_ipv6(struct sk_buff *skb) { if (ipv6_mc_check_mld(skb, NULL) < 0) return false; switch (icmp6_hdr(skb)->icmp6_type) { case ICMPV6_MGM_REPORT: case ICMPV6_MLD2_REPORT: return true; } return false; } /** * batadv_mcast_forw_mode_check_ipv6 - check for optimized forwarding potential * @bat_priv: the bat priv with all the soft interface information * @skb: the IPv6 packet to check * @is_unsnoopable: stores whether the destination is snoopable * * Checks whether the given IPv6 packet has the potential to be forwarded with a * mode more optimal than classic flooding. * * Return: If so then 0. Otherwise -EINVAL is or -ENOMEM if we are out of memory */ static int batadv_mcast_forw_mode_check_ipv6(struct batadv_priv *bat_priv, struct sk_buff *skb, bool *is_unsnoopable) { struct ipv6hdr *ip6hdr; /* We might fail due to out-of-memory -> drop it */ if (!pskb_may_pull(skb, sizeof(struct ethhdr) + sizeof(*ip6hdr))) return -ENOMEM; if (batadv_mcast_is_report_ipv6(skb)) return -EINVAL; ip6hdr = ipv6_hdr(skb); /* TODO: Implement Multicast Router Discovery (RFC4286), * then allow scope > link local, too */ if (IPV6_ADDR_MC_SCOPE(&ip6hdr->daddr) != IPV6_ADDR_SCOPE_LINKLOCAL) return -EINVAL; /* link-local-all-nodes multicast listeners behind a bridge are * not snoopable (see RFC4541, section 3, paragraph 3) */ if (ipv6_addr_is_ll_all_nodes(&ip6hdr->daddr)) *is_unsnoopable = true; return 0; } #endif /** * batadv_mcast_forw_mode_check - check for optimized forwarding potential * @bat_priv: the bat priv with all the soft interface information * @skb: the multicast frame to check * @is_unsnoopable: stores whether the destination is snoopable * * Checks whether the given multicast ethernet frame has the potential to be * forwarded with a mode more optimal than classic flooding. * * Return: If so then 0. Otherwise -EINVAL is or -ENOMEM if we are out of memory */ static int batadv_mcast_forw_mode_check(struct batadv_priv *bat_priv, struct sk_buff *skb, bool *is_unsnoopable) { struct ethhdr *ethhdr = eth_hdr(skb); if (!atomic_read(&bat_priv->multicast_mode)) return -EINVAL; if (atomic_read(&bat_priv->mcast.num_disabled)) return -EINVAL; switch (ntohs(ethhdr->h_proto)) { case ETH_P_IP: return batadv_mcast_forw_mode_check_ipv4(bat_priv, skb, is_unsnoopable); #if IS_ENABLED(CONFIG_IPV6) case ETH_P_IPV6: return batadv_mcast_forw_mode_check_ipv6(bat_priv, skb, is_unsnoopable); #endif default: return -EINVAL; } } /** * batadv_mcast_forw_want_all_ip_count - count nodes with unspecific mcast * interest * @bat_priv: the bat priv with all the soft interface information * @ethhdr: ethernet header of a packet * * Return: the number of nodes which want all IPv4 multicast traffic if the * given ethhdr is from an IPv4 packet or the number of nodes which want all * IPv6 traffic if it matches an IPv6 packet. */ static int batadv_mcast_forw_want_all_ip_count(struct batadv_priv *bat_priv, struct ethhdr *ethhdr) { switch (ntohs(ethhdr->h_proto)) { case ETH_P_IP: return atomic_read(&bat_priv->mcast.num_want_all_ipv4); case ETH_P_IPV6: return atomic_read(&bat_priv->mcast.num_want_all_ipv6); default: /* we shouldn't be here... */ return 0; } } /** * batadv_mcast_forw_tt_node_get - get a multicast tt node * @bat_priv: the bat priv with all the soft interface information * @ethhdr: the ether header containing the multicast destination * * Return: an orig_node matching the multicast address provided by ethhdr * via a translation table lookup. This increases the returned nodes refcount. */ static struct batadv_orig_node * batadv_mcast_forw_tt_node_get(struct batadv_priv *bat_priv, struct ethhdr *ethhdr) { return batadv_transtable_search(bat_priv, ethhdr->h_source, ethhdr->h_dest, BATADV_NO_FLAGS); } /** * batadv_mcast_forw_ipv4_node_get - get a node with an ipv4 flag * @bat_priv: the bat priv with all the soft interface information * * Return: an orig_node which has the BATADV_MCAST_WANT_ALL_IPV4 flag set and * increases its refcount. */ static struct batadv_orig_node * batadv_mcast_forw_ipv4_node_get(struct batadv_priv *bat_priv) { struct batadv_orig_node *tmp_orig_node, *orig_node = NULL; rcu_read_lock(); hlist_for_each_entry_rcu(tmp_orig_node, &bat_priv->mcast.want_all_ipv4_list, mcast_want_all_ipv4_node) { if (!kref_get_unless_zero(&tmp_orig_node->refcount)) continue; orig_node = tmp_orig_node; break; } rcu_read_unlock(); return orig_node; } /** * batadv_mcast_forw_ipv6_node_get - get a node with an ipv6 flag * @bat_priv: the bat priv with all the soft interface information * * Return: an orig_node which has the BATADV_MCAST_WANT_ALL_IPV6 flag set * and increases its refcount. */ static struct batadv_orig_node * batadv_mcast_forw_ipv6_node_get(struct batadv_priv *bat_priv) { struct batadv_orig_node *tmp_orig_node, *orig_node = NULL; rcu_read_lock(); hlist_for_each_entry_rcu(tmp_orig_node, &bat_priv->mcast.want_all_ipv6_list, mcast_want_all_ipv6_node) { if (!kref_get_unless_zero(&tmp_orig_node->refcount)) continue; orig_node = tmp_orig_node; break; } rcu_read_unlock(); return orig_node; } /** * batadv_mcast_forw_ip_node_get - get a node with an ipv4/ipv6 flag * @bat_priv: the bat priv with all the soft interface information * @ethhdr: an ethernet header to determine the protocol family from * * Return: an orig_node which has the BATADV_MCAST_WANT_ALL_IPV4 or * BATADV_MCAST_WANT_ALL_IPV6 flag, depending on the provided ethhdr, set and * increases its refcount. */ static struct batadv_orig_node * batadv_mcast_forw_ip_node_get(struct batadv_priv *bat_priv, struct ethhdr *ethhdr) { switch (ntohs(ethhdr->h_proto)) { case ETH_P_IP: return batadv_mcast_forw_ipv4_node_get(bat_priv); case ETH_P_IPV6: return batadv_mcast_forw_ipv6_node_get(bat_priv); default: /* we shouldn't be here... */ return NULL; } } /** * batadv_mcast_forw_unsnoop_node_get - get a node with an unsnoopable flag * @bat_priv: the bat priv with all the soft interface information * * Return: an orig_node which has the BATADV_MCAST_WANT_ALL_UNSNOOPABLES flag * set and increases its refcount. */ static struct batadv_orig_node * batadv_mcast_forw_unsnoop_node_get(struct batadv_priv *bat_priv) { struct batadv_orig_node *tmp_orig_node, *orig_node = NULL; rcu_read_lock(); hlist_for_each_entry_rcu(tmp_orig_node, &bat_priv->mcast.want_all_unsnoopables_list, mcast_want_all_unsnoopables_node) { if (!kref_get_unless_zero(&tmp_orig_node->refcount)) continue; orig_node = tmp_orig_node; break; } rcu_read_unlock(); return orig_node; } /** * batadv_mcast_forw_mode - check on how to forward a multicast packet * @bat_priv: the bat priv with all the soft interface information * @skb: The multicast packet to check * @orig: an originator to be set to forward the skb to * * Return: the forwarding mode as enum batadv_forw_mode and in case of * BATADV_FORW_SINGLE set the orig to the single originator the skb * should be forwarded to. */ enum batadv_forw_mode batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb, struct batadv_orig_node **orig) { int ret, tt_count, ip_count, unsnoop_count, total_count; bool is_unsnoopable = false; struct ethhdr *ethhdr; ret = batadv_mcast_forw_mode_check(bat_priv, skb, &is_unsnoopable); if (ret == -ENOMEM) return BATADV_FORW_NONE; else if (ret < 0) return BATADV_FORW_ALL; ethhdr = eth_hdr(skb); tt_count = batadv_tt_global_hash_count(bat_priv, ethhdr->h_dest, BATADV_NO_FLAGS); ip_count = batadv_mcast_forw_want_all_ip_count(bat_priv, ethhdr); unsnoop_count = !is_unsnoopable ? 0 : atomic_read(&bat_priv->mcast.num_want_all_unsnoopables); total_count = tt_count + ip_count + unsnoop_count; switch (total_count) { case 1: if (tt_count) *orig = batadv_mcast_forw_tt_node_get(bat_priv, ethhdr); else if (ip_count) *orig = batadv_mcast_forw_ip_node_get(bat_priv, ethhdr); else if (unsnoop_count) *orig = batadv_mcast_forw_unsnoop_node_get(bat_priv); if (*orig) return BATADV_FORW_SINGLE; /* fall through */ case 0: return BATADV_FORW_NONE; default: return BATADV_FORW_ALL; } } /** * batadv_mcast_want_unsnoop_update - update unsnoop counter and list * @bat_priv: the bat priv with all the soft interface information * @orig: the orig_node which multicast state might have changed of * @mcast_flags: flags indicating the new multicast state * * If the BATADV_MCAST_WANT_ALL_UNSNOOPABLES flag of this originator, * orig, has toggled then this method updates counter and list accordingly. * * Caller needs to hold orig->mcast_handler_lock. */ static void batadv_mcast_want_unsnoop_update(struct batadv_priv *bat_priv, struct batadv_orig_node *orig, u8 mcast_flags) { struct hlist_node *node = &orig->mcast_want_all_unsnoopables_node; struct hlist_head *head = &bat_priv->mcast.want_all_unsnoopables_list; lockdep_assert_held(&orig->mcast_handler_lock); /* switched from flag unset to set */ if (mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES && !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES)) { atomic_inc(&bat_priv->mcast.num_want_all_unsnoopables); spin_lock_bh(&bat_priv->mcast.want_lists_lock); /* flag checks above + mcast_handler_lock prevents this */ WARN_ON(!hlist_unhashed(node)); hlist_add_head_rcu(node, head); spin_unlock_bh(&bat_priv->mcast.want_lists_lock); /* switched from flag set to unset */ } else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) && orig->mcast_flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) { atomic_dec(&bat_priv->mcast.num_want_all_unsnoopables); spin_lock_bh(&bat_priv->mcast.want_lists_lock); /* flag checks above + mcast_handler_lock prevents this */ WARN_ON(hlist_unhashed(node)); hlist_del_init_rcu(node); spin_unlock_bh(&bat_priv->mcast.want_lists_lock); } } /** * batadv_mcast_want_ipv4_update - update want-all-ipv4 counter and list * @bat_priv: the bat priv with all the soft interface information * @orig: the orig_node which multicast state might have changed of * @mcast_flags: flags indicating the new multicast state * * If the BATADV_MCAST_WANT_ALL_IPV4 flag of this originator, orig, has * toggled then this method updates counter and list accordingly. * * Caller needs to hold orig->mcast_handler_lock. */ static void batadv_mcast_want_ipv4_update(struct batadv_priv *bat_priv, struct batadv_orig_node *orig, u8 mcast_flags) { struct hlist_node *node = &orig->mcast_want_all_ipv4_node; struct hlist_head *head = &bat_priv->mcast.want_all_ipv4_list; lockdep_assert_held(&orig->mcast_handler_lock); /* switched from flag unset to set */ if (mcast_flags & BATADV_MCAST_WANT_ALL_IPV4 && !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV4)) { atomic_inc(&bat_priv->mcast.num_want_all_ipv4); spin_lock_bh(&bat_priv->mcast.want_lists_lock); /* flag checks above + mcast_handler_lock prevents this */ WARN_ON(!hlist_unhashed(node)); hlist_add_head_rcu(node, head); spin_unlock_bh(&bat_priv->mcast.want_lists_lock); /* switched from flag set to unset */ } else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_IPV4) && orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV4) { atomic_dec(&bat_priv->mcast.num_want_all_ipv4); spin_lock_bh(&bat_priv->mcast.want_lists_lock); /* flag checks above + mcast_handler_lock prevents this */ WARN_ON(hlist_unhashed(node)); hlist_del_init_rcu(node); spin_unlock_bh(&bat_priv->mcast.want_lists_lock); } } /** * batadv_mcast_want_ipv6_update - update want-all-ipv6 counter and list * @bat_priv: the bat priv with all the soft interface information * @orig: the orig_node which multicast state might have changed of * @mcast_flags: flags indicating the new multicast state * * If the BATADV_MCAST_WANT_ALL_IPV6 flag of this originator, orig, has * toggled then this method updates counter and list accordingly. * * Caller needs to hold orig->mcast_handler_lock. */ static void batadv_mcast_want_ipv6_update(struct batadv_priv *bat_priv, struct batadv_orig_node *orig, u8 mcast_flags) { struct hlist_node *node = &orig->mcast_want_all_ipv6_node; struct hlist_head *head = &bat_priv->mcast.want_all_ipv6_list; lockdep_assert_held(&orig->mcast_handler_lock); /* switched from flag unset to set */ if (mcast_flags & BATADV_MCAST_WANT_ALL_IPV6 && !(orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV6)) { atomic_inc(&bat_priv->mcast.num_want_all_ipv6); spin_lock_bh(&bat_priv->mcast.want_lists_lock); /* flag checks above + mcast_handler_lock prevents this */ WARN_ON(!hlist_unhashed(node)); hlist_add_head_rcu(node, head); spin_unlock_bh(&bat_priv->mcast.want_lists_lock); /* switched from flag set to unset */ } else if (!(mcast_flags & BATADV_MCAST_WANT_ALL_IPV6) && orig->mcast_flags & BATADV_MCAST_WANT_ALL_IPV6) { atomic_dec(&bat_priv->mcast.num_want_all_ipv6); spin_lock_bh(&bat_priv->mcast.want_lists_lock); /* flag checks above + mcast_handler_lock prevents this */ WARN_ON(hlist_unhashed(node)); hlist_del_init_rcu(node); spin_unlock_bh(&bat_priv->mcast.want_lists_lock); } } /** * batadv_mcast_tvlv_ogm_handler - process incoming multicast tvlv container * @bat_priv: the bat priv with all the soft interface information * @orig: the orig_node of the ogm * @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags) * @tvlv_value: tvlv buffer containing the multicast data * @tvlv_value_len: tvlv buffer length */ static void batadv_mcast_tvlv_ogm_handler(struct batadv_priv *bat_priv, struct batadv_orig_node *orig, u8 flags, void *tvlv_value, u16 tvlv_value_len) { bool orig_mcast_enabled = !(flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND); u8 mcast_flags = BATADV_NO_FLAGS; bool orig_initialized; if (orig_mcast_enabled && tvlv_value && (tvlv_value_len >= sizeof(mcast_flags))) mcast_flags = *(u8 *)tvlv_value; spin_lock_bh(&orig->mcast_handler_lock); orig_initialized = test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized); /* If mcast support is turned on decrease the disabled mcast node * counter only if we had increased it for this node before. If this * is a completely new orig_node no need to decrease the counter. */ if (orig_mcast_enabled && !test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities)) { if (orig_initialized) atomic_dec(&bat_priv->mcast.num_disabled); set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities); /* If mcast support is being switched off or if this is an initial * OGM without mcast support then increase the disabled mcast * node counter. */ } else if (!orig_mcast_enabled && (test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities) || !orig_initialized)) { atomic_inc(&bat_priv->mcast.num_disabled); clear_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities); } set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized); batadv_mcast_want_unsnoop_update(bat_priv, orig, mcast_flags); batadv_mcast_want_ipv4_update(bat_priv, orig, mcast_flags); batadv_mcast_want_ipv6_update(bat_priv, orig, mcast_flags); orig->mcast_flags = mcast_flags; spin_unlock_bh(&orig->mcast_handler_lock); } /** * batadv_mcast_init - initialize the multicast optimizations structures * @bat_priv: the bat priv with all the soft interface information */ void batadv_mcast_init(struct batadv_priv *bat_priv) { batadv_tvlv_handler_register(bat_priv, batadv_mcast_tvlv_ogm_handler, NULL, BATADV_TVLV_MCAST, 2, BATADV_TVLV_HANDLER_OGM_CIFNOTFND); INIT_DELAYED_WORK(&bat_priv->mcast.work, batadv_mcast_mla_update); batadv_mcast_start_timer(bat_priv); } #ifdef CONFIG_BATMAN_ADV_DEBUGFS /** * batadv_mcast_flags_print_header - print own mcast flags to debugfs table * @bat_priv: the bat priv with all the soft interface information * @seq: debugfs table seq_file struct * * Prints our own multicast flags including a more specific reason why * they are set, that is prints the bridge and querier state too, to * the debugfs table specified via @seq. */ static void batadv_mcast_flags_print_header(struct batadv_priv *bat_priv, struct seq_file *seq) { u8 flags = bat_priv->mcast.flags; char querier4, querier6, shadowing4, shadowing6; bool bridged = bat_priv->mcast.bridged; if (bridged) { querier4 = bat_priv->mcast.querier_ipv4.exists ? '.' : '4'; querier6 = bat_priv->mcast.querier_ipv6.exists ? '.' : '6'; shadowing4 = bat_priv->mcast.querier_ipv4.shadowing ? '4' : '.'; shadowing6 = bat_priv->mcast.querier_ipv6.shadowing ? '6' : '.'; } else { querier4 = '?'; querier6 = '?'; shadowing4 = '?'; shadowing6 = '?'; } seq_printf(seq, "Multicast flags (own flags: [%c%c%c])\n", (flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.', (flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.', (flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.'); seq_printf(seq, "* Bridged [U]\t\t\t\t%c\n", bridged ? 'U' : '.'); seq_printf(seq, "* No IGMP/MLD Querier [4/6]:\t\t%c/%c\n", querier4, querier6); seq_printf(seq, "* Shadowing IGMP/MLD Querier [4/6]:\t%c/%c\n", shadowing4, shadowing6); seq_puts(seq, "-------------------------------------------\n"); seq_printf(seq, " %-10s %s\n", "Originator", "Flags"); } /** * batadv_mcast_flags_seq_print_text - print the mcast flags of other nodes * @seq: seq file to print on * @offset: not used * * This prints a table of (primary) originators and their according * multicast flags, including (in the header) our own. * * Return: always 0 */ int batadv_mcast_flags_seq_print_text(struct seq_file *seq, void *offset) { struct net_device *net_dev = (struct net_device *)seq->private; struct batadv_priv *bat_priv = netdev_priv(net_dev); struct batadv_hard_iface *primary_if; struct batadv_hashtable *hash = bat_priv->orig_hash; struct batadv_orig_node *orig_node; struct hlist_head *head; u8 flags; u32 i; primary_if = batadv_seq_print_text_primary_if_get(seq); if (!primary_if) return 0; batadv_mcast_flags_print_header(bat_priv, seq); for (i = 0; i < hash->size; i++) { head = &hash->table[i]; rcu_read_lock(); hlist_for_each_entry_rcu(orig_node, head, hash_entry) { if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig_node->capa_initialized)) continue; if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig_node->capabilities)) { seq_printf(seq, "%pM -\n", orig_node->orig); continue; } flags = orig_node->mcast_flags; seq_printf(seq, "%pM [%c%c%c]\n", orig_node->orig, (flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.', (flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.', (flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.'); } rcu_read_unlock(); } batadv_hardif_put(primary_if); return 0; } #endif /** * batadv_mcast_free - free the multicast optimizations structures * @bat_priv: the bat priv with all the soft interface information */ void batadv_mcast_free(struct batadv_priv *bat_priv) { cancel_delayed_work_sync(&bat_priv->mcast.work); batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_MCAST, 2); batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_MCAST, 2); /* safely calling outside of worker, as worker was canceled above */ batadv_mcast_mla_tt_retract(bat_priv, NULL); } /** * batadv_mcast_purge_orig - reset originator global mcast state modifications * @orig: the originator which is going to get purged */ void batadv_mcast_purge_orig(struct batadv_orig_node *orig) { struct batadv_priv *bat_priv = orig->bat_priv; spin_lock_bh(&orig->mcast_handler_lock); if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities) && test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized)) atomic_dec(&bat_priv->mcast.num_disabled); batadv_mcast_want_unsnoop_update(bat_priv, orig, BATADV_NO_FLAGS); batadv_mcast_want_ipv4_update(bat_priv, orig, BATADV_NO_FLAGS); batadv_mcast_want_ipv6_update(bat_priv, orig, BATADV_NO_FLAGS); spin_unlock_bh(&orig->mcast_handler_lock); }