The data structures and locking mechanisms for fetching multicast mac addresses from a net_device have changed a little between kernel versions 2.6.21 to 2.6.35.

Therefore this commit backports two macros (netdev_mc_count(), netdev_for_each_mc_addr()) for older kernel versions and abstracts the way of locking and accessing the variables with own customized macros.

Signed-off-by: Linus Lüssing linus.luessing@saxnet.de --- compat.h | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 49 insertions(+), 0 deletions(-)

diff --git a/compat.h b/compat.h index b01455f..bbb1dad 100644 --- a/compat.h +++ b/compat.h @@ -264,4 +264,53 @@ int bat_seq_printf(struct seq_file *m, const char *f, ...);

#endif /* < KERNEL_VERSION(2, 6, 29) */

+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 34) + +#define netdev_mc_count(dev) ((dev)->mc_count) +#define netdev_for_each_mc_addr(mclist, dev) \ + for (mclist = dev->mc_list; mclist; mclist = mclist->next) + +#endif /* < KERNEL_VERSION(2, 6, 34) */ + + +/* + * net_device - multicast list handling + * structures + */ +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 35) + +#define MC_LIST struct dev_addr_list +#define MC_LIST_ADDR da_addr + +#endif /* < KERNEL_VERSION(2, 6, 35) */ + +#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 34) + +#define MC_LIST struct netdev_hw_addr_list_mc +#define MC_LIST_ADDR addr + +#endif /* > KERNEL_VERSION(2, 6, 34) */ + +/* + * net_device - multicast list handling + * locking + */ +#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 27) + +#define MC_LIST_LOCK(soft_iface, flags) \ + spin_lock_irqsave(&soft_iface->_xmit_lock, flags) +#define MC_LIST_UNLOCK(soft_iface, flags) \ + spin_unlock_irqrestore(&soft_iface->_xmit_lock, flags) + +#endif /* LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 27) */ + +#if LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 26) + +#define MC_LIST_LOCK(soft_iface, flags) \ + spin_lock_irqsave(&soft_iface->addr_list_lock, flags) +#define MC_LIST_UNLOCK(soft_iface, flags) \ + spin_unlock_irqrestore(&soft_iface->addr_list_lock, flags) + +#endif /* > KERNEL_VERSION(2, 6, 26) */ + #endif /* _NET_BATMAN_ADV_COMPAT_H_ */

This commit adds a timer for sending periodic tracker packets (the sending is not in the scope of this patch). Furthermore, the timer gets restarted if the tracker interval gets changed or if the originator interval changed and we have selected auto mode for the tracker interval.

Signed-off-by: Linus Lüssing linus.luessing@saxnet.de --- bat_sysfs.c | 13 +++++++++++-- main.c | 5 +++++ multicast.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ multicast.h | 3 +++ types.h | 1 + 5 files changed, 77 insertions(+), 2 deletions(-)

diff --git a/bat_sysfs.c b/bat_sysfs.c index f627d70..8f688db 100644 --- a/bat_sysfs.c +++ b/bat_sysfs.c @@ -357,8 +357,16 @@ static ssize_t store_gw_bwidth(struct kobject *kobj, struct attribute *attr, return gw_bandwidth_set(net_dev, buff, count); }

+void update_mcast_tracker(struct net_device *net_dev) +{ + struct bat_priv *bat_priv = netdev_priv(net_dev); + + if (!atomic_read(&bat_priv->mcast_tracker_interval)) + mcast_tracker_reset(bat_priv); +} + static ssize_t show_mcast_mode(struct kobject *kobj, struct attribute *attr, - char *buff) + char *buff) { struct device *dev = to_dev(kobj->parent); struct bat_priv *bat_priv = netdev_priv(to_net_dev(dev)); @@ -509,7 +517,8 @@ BAT_ATTR_BOOL(bonding, S_IRUGO | S_IWUSR, NULL); BAT_ATTR_BOOL(fragmentation, S_IRUGO | S_IWUSR, update_min_mtu); static BAT_ATTR(vis_mode, S_IRUGO | S_IWUSR, show_vis_mode, store_vis_mode); static BAT_ATTR(gw_mode, S_IRUGO | S_IWUSR, show_gw_mode, store_gw_mode); -BAT_ATTR_UINT(orig_interval, S_IRUGO | S_IWUSR, 2 * JITTER, INT_MAX, NULL); +BAT_ATTR_UINT(orig_interval, S_IRUGO | S_IWUSR, 2 * JITTER, INT_MAX, + update_mcast_tracker); BAT_ATTR_UINT(hop_penalty, S_IRUGO | S_IWUSR, 0, TQ_MAX_VALUE, NULL); BAT_ATTR_UINT(gw_sel_class, S_IRUGO | S_IWUSR, 1, TQ_MAX_VALUE, post_gw_deselect); diff --git a/main.c b/main.c index b827f6a..135ac89 100644 --- a/main.c +++ b/main.c @@ -32,6 +32,7 @@ #include "gateway_client.h" #include "types.h" #include "vis.h" +#include "multicast.h" #include "hash.h"

struct list_head if_list; @@ -109,6 +110,9 @@ int mesh_init(struct net_device *soft_iface) if (vis_init(bat_priv) < 1) goto err;

+ if (mcast_init(bat_priv) < 1) + goto err; + atomic_set(&bat_priv->mesh_state, MESH_ACTIVE); goto end;

@@ -139,6 +143,7 @@ void mesh_free(struct net_device *soft_iface) hna_global_free(bat_priv);

softif_neigh_purge(bat_priv); + mcast_free(bat_priv);

atomic_set(&bat_priv->mesh_state, MESH_INACTIVE); } diff --git a/multicast.c b/multicast.c index 0598873..1ddd37b 100644 --- a/multicast.c +++ b/multicast.c @@ -22,6 +22,48 @@ #include "main.h" #include "multicast.h"

+/* how long to wait until sending a multicast tracker packet */ +static int tracker_send_delay(struct bat_priv *bat_priv) +{ + int tracker_interval = atomic_read(&bat_priv->mcast_tracker_interval); + + /* auto mode, set to 1/2 ogm interval */ + if (!tracker_interval) + tracker_interval = atomic_read(&bat_priv->orig_interval) / 2; + + /* multicast tracker packets get half as much jitter as ogms as they're + * limited down to JITTER and not JITTER*2 */ + return msecs_to_jiffies(tracker_interval - + JITTER/2 + (random32() % JITTER)); +} + +static void start_mcast_tracker(struct bat_priv *bat_priv) +{ + // adding some jitter + unsigned long tracker_interval = tracker_send_delay(bat_priv); + queue_delayed_work(bat_event_workqueue, &bat_priv->mcast_tracker_work, + tracker_interval); +} + +static void stop_mcast_tracker(struct bat_priv *bat_priv) +{ + cancel_delayed_work_sync(&bat_priv->mcast_tracker_work); +} + +void mcast_tracker_reset(struct bat_priv *bat_priv) +{ + stop_mcast_tracker(bat_priv); + start_mcast_tracker(bat_priv); +} + +static void mcast_tracker_timer(struct work_struct *work) +{ + struct bat_priv *bat_priv = container_of(work, struct bat_priv, + mcast_tracker_work.work); + + start_mcast_tracker(bat_priv); +} + int mcast_tracker_interval_set(struct net_device *net_dev, char *buff, size_t count) { @@ -68,6 +110,8 @@ ok:

atomic_set(&bat_priv->mcast_tracker_interval, new_tracker_interval);

+ mcast_tracker_reset(bat_priv); + return count; }

@@ -119,3 +163,16 @@ ok:

return count; } + +int mcast_init(struct bat_priv *bat_priv) +{ + INIT_DELAYED_WORK(&bat_priv->mcast_tracker_work, mcast_tracker_timer); + start_mcast_tracker(bat_priv); + + return 1; +} + +void mcast_free(struct bat_priv *bat_priv) +{ + stop_mcast_tracker(bat_priv); +} diff --git a/multicast.h b/multicast.h index 12a3376..26ce6d8 100644 --- a/multicast.h +++ b/multicast.h @@ -26,5 +26,8 @@ int mcast_tracker_interval_set(struct net_device *net_dev, char *buff, size_t count); int mcast_tracker_timeout_set(struct net_device *net_dev, char *buff, size_t count); +void mcast_tracker_reset(struct bat_priv *bat_priv); +int mcast_init(struct bat_priv *bat_priv); +void mcast_free(struct bat_priv *bat_priv);

#endif /* _NET_BATMAN_ADV_MULTICAST_H_ */ diff --git a/types.h b/types.h index b61d5a8..41eabfe 100644 --- a/types.h +++ b/types.h @@ -169,6 +169,7 @@ struct bat_priv { struct delayed_work hna_work; struct delayed_work orig_work; struct delayed_work vis_work; + struct delayed_work mcast_tracker_work; struct gw_node *curr_gw; struct vis_info *my_vis_info; };

This commit introduces batman multicast tracker packets. Their job is, to mark nodes responsible for forwarding multicast data later (so a multicast receiver will not be marked, only the forwarding nodes).

When having activated the proact_tracking multicast mode, a path between all multicast _receivers_ of a group will be marked - in fact, in this mode BATMAN will assume, that a multicast receiver is also a multicast sender, therefore a multicast sender should also join the same multicast group.

The advantage of this is less complexity and the paths are marked in advance before an actual data packet has been sent, decreasing delays. The disadvantage is higher protocol overhead.

One large tracker packet will be created on a generating node first, which then gets split for every necessary next hop destination.

This commit does not add forwarding of tracker packets but just local generation and local sending of them.

Signed-off-by: Linus Lüssing linus.luessing@saxnet.de --- hash.h | 4 + multicast.c | 469 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ multicast.h | 3 + 3 files changed, 476 insertions(+), 0 deletions(-)

diff --git a/hash.h b/hash.h index 0b61c6e..d61c185 100644 --- a/hash.h +++ b/hash.h @@ -28,6 +28,10 @@ .index = 0, .walk = NULL, \ .safe = NULL}

+#define HASHIT_RESET(name) \ + name.index = 0, name.walk = NULL; \ + name.safe = NULL + /* callback to a compare function. should * compare 2 element datas for their keys, * return 0 if same and not 0 if not diff --git a/multicast.c b/multicast.c index 1ddd37b..bfb1410 100644 --- a/multicast.c +++ b/multicast.c @@ -21,6 +21,24 @@

#include "main.h" #include "multicast.h" +#include "hash.h" +#include "send.h" +#include "compat.h" + +#define tracker_packet_for_each_dest(mcast_entry, dest_entry, mcast_num, dest_num, tracker_packet) \ + for (mcast_num = 0, mcast_entry = (struct mcast_entry *)(tracker_packet + 1), \ + dest_entry = (uint8_t *)(mcast_entry + 1); \ + mcast_num < tracker_packet->num_mcast_entries; mcast_num++, \ + mcast_entry = (struct mcast_entry *)dest_entry, \ + dest_entry = (uint8_t *)(mcast_entry + 1)) \ + for (dest_num = 0; dest_num < mcast_entry->num_dest; dest_num++, \ + dest_entry += ETH_ALEN) + +struct dest_entries_list { + struct list_head list; + uint8_t dest[6]; + struct batman_if *batman_if; +};

/* how long to wait until sending a multicast tracker packet */ static int tracker_send_delay(struct bat_priv *bat_priv) @@ -56,11 +74,462 @@ void mcast_tracker_reset(struct bat_priv *bat_priv) start_mcast_tracker(bat_priv); }

+static inline int find_mca_match(struct orig_node *orig_node, + int mca_pos, uint8_t *mc_addr_list, int num_mcast_entries) +{ + int pos; + + for (pos = 0; pos < num_mcast_entries; pos++) + if (!memcmp(&mc_addr_list[pos*ETH_ALEN], + &orig_node->mca_buff[ETH_ALEN*mca_pos], ETH_ALEN)) + return pos; + return -1; +} + +/** + * Prepares a multicast tracker packet on a multicast member with all its + * groups and their members attached. Note, that the proactive tracking + * mode does not differentiate between multicast senders and receivers, + * resulting in tracker packets between each node. + * + * Returns NULL if this node is not a member of any group or if there are + * no other members in its groups. + * + * @bat_priv: bat_priv for the mesh we are preparing this packet + */ +static struct mcast_tracker_packet *mcast_proact_tracker_prepare( + struct bat_priv *bat_priv, int *tracker_packet_len) +{ + struct net_device *soft_iface = bat_priv->primary_if->soft_iface; + uint8_t *mc_addr_list; + MC_LIST *mc_entry; + struct element_t *bucket; + struct orig_node *orig_node; + + /* one dest_entries_list per multicast group, + * they'll collect dest_entries[x] */ + int num_mcast_entries, used_mcast_entries = 0; + struct list_head *dest_entries_list; + struct dest_entries_list dest_entries[UINT8_MAX], *dest, *tmp; + int num_dest_entries, dest_entries_total = 0; + + uint8_t *dest_entry; + int pos, mca_pos; + unsigned long flags; + struct mcast_tracker_packet *tracker_packet = NULL; + struct mcast_entry *mcast_entry; + HASHIT(hashit); + + /* Make a copy so we don't have to rush because of locking */ + MC_LIST_LOCK(soft_iface, flags); + num_mcast_entries = netdev_mc_count(soft_iface); + mc_addr_list = kmalloc(ETH_ALEN * num_mcast_entries, GFP_ATOMIC); + if (!mc_addr_list) { + MC_LIST_UNLOCK(soft_iface, flags); + goto out; + } + pos = 0; + netdev_for_each_mc_addr(mc_entry, soft_iface) { + memcpy(&mc_addr_list[pos * ETH_ALEN], mc_entry->MC_LIST_ADDR, + ETH_ALEN); + pos++; + } + MC_LIST_UNLOCK(soft_iface, flags); + + if (num_mcast_entries > UINT8_MAX) + num_mcast_entries = UINT8_MAX; + dest_entries_list = kmalloc(num_mcast_entries * + sizeof(struct list_head), GFP_ATOMIC); + if (!dest_entries_list) + goto free; + + for (pos = 0; pos < num_mcast_entries; pos++) + INIT_LIST_HEAD(&dest_entries_list[pos]); + + /* fill the lists and buffers */ + spin_lock_irqsave(&bat_priv->orig_hash_lock, flags); + while (hash_iterate(bat_priv->orig_hash, &hashit)) { + bucket = hlist_entry(hashit.walk, struct element_t, hlist); + orig_node = bucket->data; + if (!orig_node->num_mca) + continue; + + num_dest_entries = 0; + for (mca_pos = 0; mca_pos < orig_node->num_mca && dest_entries_total != UINT8_MAX; mca_pos++) { + pos = find_mca_match(orig_node, mca_pos, mc_addr_list, + num_mcast_entries); + if (pos > UINT8_MAX || pos < 0) + continue; + memcpy(dest_entries[dest_entries_total].dest, orig_node->orig, ETH_ALEN); + list_add(&dest_entries[dest_entries_total].list, &dest_entries_list[pos]); + + num_dest_entries++; + dest_entries_total++; + } + } + spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags); + + /* Any list left empty? */ + for (pos = 0; pos < num_mcast_entries; pos++) + if (!list_empty(&dest_entries_list[pos])) + used_mcast_entries++; + + if (!used_mcast_entries) + goto free_all; + + /* prepare tracker packet, finally! */ + *tracker_packet_len = sizeof(struct mcast_tracker_packet) + + sizeof(struct mcast_entry) * used_mcast_entries + + ETH_ALEN * dest_entries_total; + if (*tracker_packet_len > ETH_DATA_LEN) { + pr_warning("mcast tracker packet got too large (%i Bytes), " + "forcing reduced size of %i Bytes\n", + *tracker_packet_len, ETH_DATA_LEN); + *tracker_packet_len = ETH_DATA_LEN; + } + tracker_packet = kmalloc(*tracker_packet_len, GFP_ATOMIC); + + tracker_packet->packet_type = BAT_MCAST_TRACKER; + tracker_packet->version = COMPAT_VERSION; + memcpy(tracker_packet->orig, bat_priv->primary_if->net_dev->dev_addr, + ETH_ALEN); + tracker_packet->ttl = TTL; + tracker_packet->num_mcast_entries = (used_mcast_entries > UINT8_MAX) ? + UINT8_MAX : used_mcast_entries; + memset(tracker_packet->align, 0, sizeof(tracker_packet->align)); + + /* append all collected entries */ + mcast_entry = (struct mcast_entry *)(tracker_packet + 1); + for (pos = 0; pos < num_mcast_entries; pos++) { + if (list_empty(&dest_entries_list[pos])) + continue; + + if ((char *)(mcast_entry + 1) <= + (char *)tracker_packet + ETH_DATA_LEN) { + memcpy(mcast_entry->mcast_addr, + &mc_addr_list[pos*ETH_ALEN], ETH_ALEN); + mcast_entry->num_dest = 0; + } + + dest_entry = (uint8_t *)(mcast_entry + 1); + list_for_each_entry_safe(dest, tmp, &dest_entries_list[pos], + list) { + /* still place for a dest_entry left? + * watch out for overflow here, stop at UINT8_MAX */ + if ((char *)dest_entry + ETH_ALEN <= + (char *)tracker_packet + ETH_DATA_LEN && + mcast_entry->num_dest != UINT8_MAX) { + mcast_entry->num_dest++; + memcpy(dest_entry, dest->dest, ETH_ALEN); + dest_entry += ETH_ALEN; + } + list_del(&dest->list); + } + /* still space for another mcast_entry left? */ + if ((char *)(mcast_entry + 1) <= + (char *)tracker_packet + ETH_DATA_LEN) + mcast_entry = (struct mcast_entry*)dest_entry; + } + + + /* outstanding cleanup */ +free_all: + kfree(dest_entries_list); +free: + kfree(mc_addr_list); +out: + + return tracker_packet; +} + +/* Adds the router for the destination address to the next_hop list and its + * interface to the forw_if_list - but only if this router has not been + * added yet */ +static int add_router_of_dest(struct dest_entries_list *next_hops, + uint8_t *dest, struct bat_priv *bat_priv) +{ + struct dest_entries_list *next_hop_tmp, *next_hop_entry; + unsigned long flags; + struct element_t *bucket; + struct orig_node *orig_node; + HASHIT(hashit); + + next_hop_entry = kmalloc(sizeof(struct dest_entries_list), GFP_ATOMIC); + if (!next_hop_entry) + return 1; + + next_hop_entry->batman_if = NULL; + spin_lock_irqsave(&bat_priv->orig_hash_lock, flags); + while (hash_iterate(bat_priv->orig_hash, &hashit)) { + bucket = hlist_entry(hashit.walk, struct element_t, hlist); + orig_node = bucket->data; + + if (memcmp(orig_node->orig, dest, ETH_ALEN)) + continue; + + if (!orig_node->router) + break; + + memcpy(next_hop_entry->dest, orig_node->router->addr, + ETH_ALEN); + next_hop_entry->batman_if = orig_node->router->if_incoming; + break; + } + spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags); + if (!next_hop_entry->batman_if) + goto free; + + list_for_each_entry(next_hop_tmp, &next_hops->list, list) + if (!memcmp(next_hop_tmp->dest, next_hop_entry->dest, + ETH_ALEN)) + goto free; + + list_add(&next_hop_entry->list, &next_hops->list); + + return 0; + +free: + kfree(next_hop_entry); + return 1; +} + +/* Collect nexthops for all dest entries specified in this tracker packet */ +static int tracker_next_hops(struct mcast_tracker_packet *tracker_packet, + struct dest_entries_list *next_hops, + struct bat_priv *bat_priv) +{ + int num_next_hops = 0, mcast_num, dest_num, ret; + struct mcast_entry *mcast_entry; + uint8_t *dest_entry; + + INIT_LIST_HEAD(&next_hops->list); + + tracker_packet_for_each_dest(mcast_entry, dest_entry, + mcast_num, dest_num, tracker_packet) { + ret = add_router_of_dest(next_hops, dest_entry, + bat_priv); + if (!ret) + num_next_hops++; + } + + return num_next_hops; +} + +static void zero_tracker_packet(struct mcast_tracker_packet *tracker_packet, + uint8_t *next_hop, struct bat_priv *bat_priv) +{ + struct mcast_entry *mcast_entry; + uint8_t *dest_entry; + int mcast_num, dest_num; + + unsigned long flags; + struct element_t *bucket; + struct orig_node *orig_node; + HASHIT(hashit); + + spin_lock_irqsave(&bat_priv->orig_hash_lock, flags); + tracker_packet_for_each_dest(mcast_entry, dest_entry, + mcast_num, dest_num, tracker_packet) { + while (hash_iterate(bat_priv->orig_hash, &hashit)) { + bucket = hlist_entry(hashit.walk, struct element_t, + hlist); + orig_node = bucket->data; + + if (memcmp(orig_node->orig, dest_entry, ETH_ALEN)) + continue; + + /* is the next hop already our destination? */ + if (!memcmp(orig_node->orig, next_hop, ETH_ALEN)) + memset(dest_entry, '\0', ETH_ALEN); + else if (!orig_node->router) + memset(dest_entry, '\0', ETH_ALEN); + else if (!memcmp(orig_node->orig, + orig_node->router->orig_node->primary_addr, + ETH_ALEN)) + memset(dest_entry, '\0', ETH_ALEN); + /* is this the wrong next hop for our destination? */ + else if (memcmp(orig_node->router->addr, + next_hop, ETH_ALEN)) + memset(dest_entry, '\0', ETH_ALEN); + + break; + } + HASHIT_RESET(hashit); + } + spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags); +} + +static int shrink_tracker_packet(struct mcast_tracker_packet *tracker_packet, + int tracker_packet_len) +{ + struct mcast_entry *mcast_entry; + uint8_t *dest_entry; + uint8_t *tail = (uint8_t *)tracker_packet + tracker_packet_len; + int mcast_num, dest_num; + int new_tracker_packet_len = sizeof(struct mcast_tracker_packet); + + tracker_packet_for_each_dest(mcast_entry, dest_entry, + mcast_num, dest_num, tracker_packet) { + if (memcmp(dest_entry, "\0\0\0\0\0\0", ETH_ALEN)) { + new_tracker_packet_len += ETH_ALEN; + continue; + } + + memmove(dest_entry, dest_entry + ETH_ALEN, + tail - dest_entry - ETH_ALEN); + + mcast_entry->num_dest--; + tail -= ETH_ALEN; + + if (mcast_entry->num_dest) { + dest_num--; + dest_entry -= ETH_ALEN; + continue; + } + + /* = mcast_entry */ + dest_entry -= sizeof(struct mcast_entry); + + memmove(dest_entry, dest_entry + sizeof(struct mcast_entry), + tail - dest_entry - sizeof(struct mcast_entry)); + + tracker_packet->num_mcast_entries--; + tail -= sizeof(struct mcast_entry); + + mcast_num--; + + /* Avoid mcast_entry check of tracker_packet_for_each_dest's + * inner loop */ + break; + } + + new_tracker_packet_len += sizeof(struct mcast_entry) * + tracker_packet->num_mcast_entries; + + return new_tracker_packet_len; +} + +static struct sk_buff *build_tracker_packet_skb( + struct mcast_tracker_packet *tracker_packet, + int tracker_packet_len, uint8_t *dest) +{ + struct sk_buff *skb; + struct mcast_tracker_packet *skb_tracker_data; + + skb = dev_alloc_skb(tracker_packet_len + sizeof(struct ethhdr)); + if (!skb) + return NULL; + + skb_reserve(skb, sizeof(struct ethhdr)); + skb_tracker_data = (struct mcast_tracker_packet *) + skb_put(skb, tracker_packet_len); + + memcpy(skb_tracker_data, tracker_packet, tracker_packet_len); + + return skb; +} + + +/** + * Sends (splitted parts of) a multicast tracker packet on the according + * interfaces. + * + * @tracker_packet: A compact multicast tracker packet with all groups and + * destinations attached. + */ +void route_mcast_tracker_packet( + struct mcast_tracker_packet *tracker_packet, + int tracker_packet_len, struct bat_priv *bat_priv) +{ + struct dest_entries_list next_hops, *tmp; + struct mcast_tracker_packet *next_hop_tracker_packets, + *next_hop_tracker_packet; + struct dest_entries_list *next_hop; + struct sk_buff *skb; + int num_next_hops, i; + int *tracker_packet_lengths; + + rcu_read_lock(); + num_next_hops = tracker_next_hops(tracker_packet, &next_hops, + bat_priv); + if (!num_next_hops) + goto out; + next_hop_tracker_packets = kmalloc(tracker_packet_len * num_next_hops, + GFP_ATOMIC); + if (!next_hop_tracker_packets) + goto free; + + tracker_packet_lengths = kmalloc(sizeof(int) * num_next_hops, + GFP_ATOMIC); + if (!tracker_packet_lengths) + goto free2; + + i = 0; + list_for_each_entry_safe(next_hop, tmp, &next_hops.list, list) { + next_hop_tracker_packet = (struct mcast_tracker_packet *) + ((char *)next_hop_tracker_packets + + i * tracker_packet_len); + memcpy(next_hop_tracker_packet, tracker_packet, + tracker_packet_len); + zero_tracker_packet(next_hop_tracker_packet, next_hop->dest, + bat_priv); + tracker_packet_lengths[i] = shrink_tracker_packet( + next_hop_tracker_packet, tracker_packet_len); + i++; + } + + i = 0; + /* Add ethernet header, send 'em! */ + list_for_each_entry_safe(next_hop, tmp, &next_hops.list, list) { + if (tracker_packet_lengths[i] == + sizeof(struct mcast_tracker_packet)) + goto skip_send; + + skb = build_tracker_packet_skb(&next_hop_tracker_packets[i], + tracker_packet_lengths[i], + next_hop->dest); + if (skb) + send_skb_packet(skb, next_hop->batman_if, + next_hop->dest); +skip_send: + list_del(&next_hop->list); + kfree(next_hop); + i++; + } + + kfree(tracker_packet_lengths); + kfree(next_hop_tracker_packets); + return; + +free2: + kfree(next_hop_tracker_packets); +free: + list_for_each_entry_safe(next_hop, tmp, &next_hops.list, list) { + list_del(&next_hop->list); + kfree(next_hop); + } +out: + rcu_read_unlock(); +} + static void mcast_tracker_timer(struct work_struct *work) { struct bat_priv *bat_priv = container_of(work, struct bat_priv, mcast_tracker_work.work); + struct mcast_tracker_packet *tracker_packet = NULL; + int tracker_packet_len = 0; + + if (atomic_read(&bat_priv->mcast_mode) == MCAST_MODE_PROACT_TRACKING) + tracker_packet = mcast_proact_tracker_prepare(bat_priv, + &tracker_packet_len); + + if (!tracker_packet) + goto out; + + route_mcast_tracker_packet(tracker_packet, tracker_packet_len, bat_priv); + kfree(tracker_packet);

+out: start_mcast_tracker(bat_priv); }

diff --git a/multicast.h b/multicast.h index 26ce6d8..2711d8b 100644 --- a/multicast.h +++ b/multicast.h @@ -27,6 +27,9 @@ int mcast_tracker_interval_set(struct net_device *net_dev, char *buff, int mcast_tracker_timeout_set(struct net_device *net_dev, char *buff, size_t count); void mcast_tracker_reset(struct bat_priv *bat_priv); +void route_mcast_tracker_packet( + struct mcast_tracker_packet *tracker_packet, + int tracker_packet_len, struct bat_priv *bat_priv); int mcast_init(struct bat_priv *bat_priv); void mcast_free(struct bat_priv *bat_priv);

Before/while a tracker packet is being searched for next hops for its destination entries, it will also be checked if the number of destination and mcast entries might exceed the tracker_packet_len. Otherwise we might read/write in unallocated memory. Such a broken tracker packet could potentially occure when we are going to reuse route_mcast_tracker_packet for tracker packets received from a neighbour node.

In such a case, we are just reducing the stated mcast / dest numbers in the tracker packet to fit the size of the allocated buffer.

Signed-off-by: Linus Lüssing linus.luessing@saxnet.de --- multicast.c | 29 +++++++++++++++++++++++++---- 1 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/multicast.c b/multicast.c index bfb1410..2b3d613 100644 --- a/multicast.c +++ b/multicast.c @@ -293,25 +293,46 @@ free: return 1; }

-/* Collect nexthops for all dest entries specified in this tracker packet */ +/* Collect nexthops for all dest entries specified in this tracker packet. + * It also reduces the number of elements in the tracker packet if they exceed + * the buffers length (i.g. because of a received, broken tracker packet) to + * avoid writing in unallocated memory. */ static int tracker_next_hops(struct mcast_tracker_packet *tracker_packet, + int tracker_packet_len, struct dest_entries_list *next_hops, struct bat_priv *bat_priv) { int num_next_hops = 0, mcast_num, dest_num, ret; struct mcast_entry *mcast_entry; uint8_t *dest_entry; + uint8_t *tail = (uint8_t *)tracker_packet + tracker_packet_len;

INIT_LIST_HEAD(&next_hops->list);

tracker_packet_for_each_dest(mcast_entry, dest_entry, mcast_num, dest_num, tracker_packet) { + /* avoid writing outside of unallocated memory later */ + if (dest_entry + ETH_ALEN > tail) { + bat_dbg(DBG_BATMAN, bat_priv, + "mcast tracker packet is broken, too many " + "entries claimed for its length, repairing"); + + tracker_packet->num_mcast_entries = mcast_num; + + if (dest_num) { + tracker_packet->num_mcast_entries++; + mcast_entry->num_dest = dest_num; + } + + goto out; + } + ret = add_router_of_dest(next_hops, dest_entry, bat_priv); if (!ret) num_next_hops++; } - +out: return num_next_hops; }

@@ -450,8 +471,8 @@ void route_mcast_tracker_packet( int *tracker_packet_lengths;

rcu_read_lock(); - num_next_hops = tracker_next_hops(tracker_packet, &next_hops, - bat_priv); + num_next_hops = tracker_next_hops(tracker_packet, tracker_packet_len, + &next_hops, bat_priv); if (!num_next_hops) goto out; next_hop_tracker_packets = kmalloc(tracker_packet_len * num_next_hops,

On reception of a multicast tracker packet (both locally generated or received over an interface), a node now memorizes its forwarding state for a tuple of multicast-group, originator, and next-hops (+ their according outgoing interface).

The first two elements are necessary to determine, whether a node shall forward a multicast data packet on reception later. The next-hop and according interface information is necessary to quickly determine, if a multicast data packet shall be forwarded via unicast to each single next hop or via broadcast.

This commit does not yet purge multicast forwarding table entries after the set tracker timeout yet.

Signed-off-by: Linus Lüssing linus.luessing@saxnet.de --- multicast.c | 278 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- types.h | 2 + 2 files changed, 277 insertions(+), 3 deletions(-)

diff --git a/multicast.c b/multicast.c index 2b3d613..c7edbef 100644 --- a/multicast.c +++ b/multicast.c @@ -25,6 +25,10 @@ #include "send.h" #include "compat.h"

+/* If auto mode for tracker timeout has been selected, + * how many times of tracker_interval to wait */ +#define TRACKER_TIMEOUT_AUTO_X 5 + #define tracker_packet_for_each_dest(mcast_entry, dest_entry, mcast_num, dest_num, tracker_packet) \ for (mcast_num = 0, mcast_entry = (struct mcast_entry *)(tracker_packet + 1), \ dest_entry = (uint8_t *)(mcast_entry + 1); \ @@ -40,6 +44,34 @@ struct dest_entries_list { struct batman_if *batman_if; };

+ +struct mcast_forw_nexthop_entry { + struct list_head list; + uint8_t neigh_addr[6]; + unsigned long timeout; /* old jiffies value */ +}; + +struct mcast_forw_if_entry { + struct list_head list; + int16_t if_num; + int num_nexthops; + struct list_head mcast_nexthop_list; +}; + +struct mcast_forw_orig_entry { + struct list_head list; + uint8_t orig[6]; + uint32_t last_mcast_seqno; + TYPE_OF_WORD mcast_bits[NUM_WORDS]; + struct list_head mcast_if_list; +}; + +struct mcast_forw_table_entry { + struct list_head list; + uint8_t mcast_addr[6]; + struct list_head mcast_orig_list; +}; + /* how long to wait until sending a multicast tracker packet */ static int tracker_send_delay(struct bat_priv *bat_priv) { @@ -74,6 +106,218 @@ void mcast_tracker_reset(struct bat_priv *bat_priv) start_mcast_tracker(bat_priv); }

+static void prepare_forw_if_entry(struct list_head *forw_if_list, + int16_t if_num, uint8_t *neigh_addr) +{ + struct mcast_forw_if_entry *forw_if_entry; + struct mcast_forw_nexthop_entry *forw_nexthop_entry; + + list_for_each_entry (forw_if_entry, forw_if_list, list) + if (forw_if_entry->if_num == if_num) + goto skip_create_if; + + forw_if_entry = kmalloc(sizeof(struct mcast_forw_if_entry), + GFP_ATOMIC); + if (!forw_if_entry) + return; + + forw_if_entry->if_num = if_num; + forw_if_entry->num_nexthops = 0; + INIT_LIST_HEAD(&forw_if_entry->mcast_nexthop_list); + list_add(&forw_if_entry->list, forw_if_list); + +skip_create_if: + list_for_each_entry (forw_nexthop_entry, + &forw_if_entry->mcast_nexthop_list, list) { + if (!memcmp(forw_nexthop_entry->neigh_addr, + neigh_addr, ETH_ALEN)) + return; + } + + forw_nexthop_entry = kmalloc(sizeof(struct mcast_forw_nexthop_entry), + GFP_ATOMIC); + if (!forw_nexthop_entry && forw_if_entry->num_nexthops) + return; + else if(!forw_nexthop_entry) + goto free; + + memcpy(forw_nexthop_entry->neigh_addr, neigh_addr, ETH_ALEN); + forw_if_entry->num_nexthops++; + if (forw_if_entry->num_nexthops < 0) { + kfree(forw_nexthop_entry); + goto free; + } + + list_add(&forw_nexthop_entry->list, + &forw_if_entry->mcast_nexthop_list); + return; +free: + list_del(&forw_if_entry->list); + kfree(forw_if_entry); +} + +static struct list_head *prepare_forw_table_entry( + struct mcast_forw_table_entry *forw_table, + uint8_t *mcast_addr, uint8_t *orig) +{ + struct mcast_forw_table_entry *forw_table_entry; + struct mcast_forw_orig_entry *orig_entry; + + forw_table_entry = kmalloc(sizeof(struct mcast_forw_table_entry), + GFP_ATOMIC); + if (!forw_table_entry) + return NULL; + + memcpy(forw_table_entry->mcast_addr, mcast_addr, ETH_ALEN); + list_add(&forw_table_entry->list, &forw_table->list); + + INIT_LIST_HEAD(&forw_table_entry->mcast_orig_list); + orig_entry = kmalloc(sizeof(struct mcast_forw_orig_entry), GFP_ATOMIC); + if (!orig_entry) + goto free; + + memcpy(orig_entry->orig, orig, ETH_ALEN); + INIT_LIST_HEAD(&orig_entry->mcast_if_list); + list_add(&orig_entry->list, &forw_table_entry->mcast_orig_list); + + return &orig_entry->mcast_if_list; + +free: + list_del(&forw_table_entry->list); + kfree(forw_table_entry); + return NULL; +} + +static int sync_nexthop(struct mcast_forw_nexthop_entry *sync_nexthop_entry, + struct list_head *nexthop_list) +{ + struct mcast_forw_nexthop_entry *nexthop_entry; + int synced = 0; + + list_for_each_entry(nexthop_entry, nexthop_list, list) { + if (memcmp(sync_nexthop_entry->neigh_addr, + nexthop_entry->neigh_addr, ETH_ALEN)) + continue; + + nexthop_entry->timeout = jiffies; + list_del(&sync_nexthop_entry->list); + kfree(sync_nexthop_entry); + + synced = 1; + break; + } + + if (!synced) { + sync_nexthop_entry->timeout = jiffies; + list_move(&sync_nexthop_entry->list, nexthop_list); + return 1; + } + + return 0; +} + +static void sync_if(struct mcast_forw_if_entry *sync_if_entry, + struct list_head *if_list) +{ + struct mcast_forw_if_entry *if_entry; + struct mcast_forw_nexthop_entry *sync_nexthop_entry, *tmp; + int synced = 0; + + list_for_each_entry(if_entry, if_list, list) { + if (sync_if_entry->if_num != if_entry->if_num) + continue; + + list_for_each_entry_safe(sync_nexthop_entry, tmp, + &sync_if_entry->mcast_nexthop_list, list) + if (sync_nexthop(sync_nexthop_entry, + &if_entry->mcast_nexthop_list)) + if_entry->num_nexthops++; + + list_del(&sync_if_entry->list); + kfree(sync_if_entry); + + synced = 1; + break; + } + + if (!synced) + list_move(&sync_if_entry->list, if_list); +} + +/* syncs all multicast entries of sync_table_entry to forw_table */ +static void sync_orig(struct mcast_forw_orig_entry *sync_orig_entry, + struct list_head *orig_list) +{ + struct mcast_forw_orig_entry *orig_entry; + struct mcast_forw_if_entry *sync_if_entry, *tmp; + int synced = 0; + + list_for_each_entry(orig_entry, orig_list, list) { + if (memcmp(sync_orig_entry->orig, + orig_entry->orig, ETH_ALEN)) + continue; + + list_for_each_entry_safe(sync_if_entry, tmp, + &sync_orig_entry->mcast_if_list, list) + sync_if(sync_if_entry, &orig_entry->mcast_if_list); + + list_del(&sync_orig_entry->list); + kfree(sync_orig_entry); + + synced = 1; + break; + } + + if (!synced) + list_move(&sync_orig_entry->list, orig_list); +} + + +/* syncs all multicast entries of sync_table_entry to forw_table */ +static void sync_table(struct mcast_forw_table_entry *sync_table_entry, + struct list_head *forw_table) +{ + struct mcast_forw_table_entry *table_entry; + struct mcast_forw_orig_entry *sync_orig_entry, *tmp; + int synced = 0; + + list_for_each_entry(table_entry, forw_table, list) { + if (memcmp(sync_table_entry->mcast_addr, + table_entry->mcast_addr, ETH_ALEN)) + continue; + + list_for_each_entry_safe(sync_orig_entry, tmp, + &sync_table_entry->mcast_orig_list, list) + sync_orig(sync_orig_entry, + &table_entry->mcast_orig_list); + + list_del(&sync_table_entry->list); + kfree(sync_table_entry); + + synced = 1; + break; + } + + if (!synced) + list_move(&sync_table_entry->list, forw_table); +} + +/* Updates the old multicast forwarding table with the information gained + * from the generated/received tracker packet. It also frees the generated + * table for syncing (*forw_table). */ +static void update_mcast_forw_table(struct mcast_forw_table_entry *forw_table, + struct bat_priv *bat_priv) +{ + struct mcast_forw_table_entry *sync_table_entry, *tmp; + unsigned long flags; + + spin_lock_irqsave(&bat_priv->mcast_forw_table_lock, flags); + list_for_each_entry_safe(sync_table_entry, tmp, &forw_table->list, + list) + sync_table(sync_table_entry, &bat_priv->mcast_forw_table); + spin_unlock_irqrestore(&bat_priv->mcast_forw_table_lock, flags); +} + static inline int find_mca_match(struct orig_node *orig_node, int mca_pos, uint8_t *mc_addr_list, int num_mcast_entries) { @@ -246,13 +490,16 @@ out: * interface to the forw_if_list - but only if this router has not been * added yet */ static int add_router_of_dest(struct dest_entries_list *next_hops, - uint8_t *dest, struct bat_priv *bat_priv) + uint8_t *dest, + struct list_head *forw_if_list, + struct bat_priv *bat_priv) { struct dest_entries_list *next_hop_tmp, *next_hop_entry; unsigned long flags; struct element_t *bucket; struct orig_node *orig_node; HASHIT(hashit); + int16_t if_num;

next_hop_entry = kmalloc(sizeof(struct dest_entries_list), GFP_ATOMIC); if (!next_hop_entry) @@ -273,12 +520,17 @@ static int add_router_of_dest(struct dest_entries_list *next_hops, memcpy(next_hop_entry->dest, orig_node->router->addr, ETH_ALEN); next_hop_entry->batman_if = orig_node->router->if_incoming; + if_num = next_hop_entry->batman_if->if_num; break; } spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags); if (!next_hop_entry->batman_if) goto free;

+ if (forw_if_list) + prepare_forw_if_entry(forw_if_list, if_num, + next_hop_entry->dest); + list_for_each_entry(next_hop_tmp, &next_hops->list, list) if (!memcmp(next_hop_tmp->dest, next_hop_entry->dest, ETH_ALEN)) @@ -300,14 +552,17 @@ free: static int tracker_next_hops(struct mcast_tracker_packet *tracker_packet, int tracker_packet_len, struct dest_entries_list *next_hops, + struct mcast_forw_table_entry *forw_table, struct bat_priv *bat_priv) { int num_next_hops = 0, mcast_num, dest_num, ret; struct mcast_entry *mcast_entry; uint8_t *dest_entry; uint8_t *tail = (uint8_t *)tracker_packet + tracker_packet_len; + struct list_head *forw_table_if = NULL;

INIT_LIST_HEAD(&next_hops->list); + INIT_LIST_HEAD(&forw_table->list);

tracker_packet_for_each_dest(mcast_entry, dest_entry, mcast_num, dest_num, tracker_packet) { @@ -327,8 +582,15 @@ static int tracker_next_hops(struct mcast_tracker_packet *tracker_packet, goto out; }

+ if (dest_num) + goto skip; + + forw_table_if = prepare_forw_table_entry(forw_table, + mcast_entry->mcast_addr, + tracker_packet->orig); +skip: ret = add_router_of_dest(next_hops, dest_entry, - bat_priv); + forw_table_if, bat_priv); if (!ret) num_next_hops++; } @@ -336,6 +598,8 @@ out: return num_next_hops; }

+/* Zero destination entries not destined for the specified next hop in the + * tracker packet */ static void zero_tracker_packet(struct mcast_tracker_packet *tracker_packet, uint8_t *next_hop, struct bat_priv *bat_priv) { @@ -380,6 +644,8 @@ static void zero_tracker_packet(struct mcast_tracker_packet *tracker_packet, spin_unlock_irqrestore(&bat_priv->orig_hash_lock, flags); }

+/* Remove zeroed destination entries and empty multicast entries in tracker + * packet */ static int shrink_tracker_packet(struct mcast_tracker_packet *tracker_packet, int tracker_packet_len) { @@ -466,15 +732,19 @@ void route_mcast_tracker_packet( struct mcast_tracker_packet *next_hop_tracker_packets, *next_hop_tracker_packet; struct dest_entries_list *next_hop; + struct mcast_forw_table_entry forw_table; struct sk_buff *skb; int num_next_hops, i; int *tracker_packet_lengths;

rcu_read_lock(); num_next_hops = tracker_next_hops(tracker_packet, tracker_packet_len, - &next_hops, bat_priv); + &next_hops, &forw_table, bat_priv); if (!num_next_hops) goto out; + + update_mcast_forw_table(&forw_table, bat_priv); + next_hop_tracker_packets = kmalloc(tracker_packet_len * num_next_hops, GFP_ATOMIC); if (!next_hop_tracker_packets) @@ -657,6 +927,8 @@ ok: int mcast_init(struct bat_priv *bat_priv) { INIT_DELAYED_WORK(&bat_priv->mcast_tracker_work, mcast_tracker_timer); + INIT_LIST_HEAD(&bat_priv->mcast_forw_table); + start_mcast_tracker(bat_priv);

return 1; diff --git a/types.h b/types.h index 0129b1f..17ccd5a 100644 --- a/types.h +++ b/types.h @@ -153,6 +153,7 @@ struct bat_priv { struct hlist_head forw_bcast_list; struct hlist_head gw_list; struct list_head vis_send_list; + struct list_head mcast_forw_table; struct hashtable_t *orig_hash; struct hashtable_t *hna_local_hash; struct hashtable_t *hna_global_hash; @@ -166,6 +167,7 @@ struct bat_priv { spinlock_t vis_hash_lock; /* protects vis_hash */ spinlock_t vis_list_lock; /* protects vis_info::recv_list */ spinlock_t softif_neigh_lock; /* protects soft-interface neigh list */ + spinlock_t mcast_forw_table_lock; /* protects mcast_forw_table */ int16_t num_local_hna; atomic_t hna_local_changed; struct delayed_work hna_work;

With this commit, the multicast forwarding table, which has been previously filled up due to multicast tracker packets, will now be checked frequently (once per second) for timeouted entries. If so these entries get removed from the table.

Note, that a more frequent check interval is not necessary, as multicast data will not only be forwarded if an entry exists, but also if that one might not have timeouted yet.

Signed-off-by: Linus Lüssing linus.luessing@saxnet.de --- multicast.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ multicast.h | 1 + originator.c | 2 ++ 3 files changed, 54 insertions(+), 0 deletions(-)

diff --git a/multicast.c b/multicast.c index edfe7e2..2b1bfde 100644 --- a/multicast.c +++ b/multicast.c @@ -821,6 +821,57 @@ out: rcu_read_unlock(); }

+void purge_mcast_forw_table(struct bat_priv *bat_priv) +{ + unsigned long flags; + struct mcast_forw_table_entry *table_entry, *tmp_table_entry; + struct mcast_forw_orig_entry *orig_entry, *tmp_orig_entry; + struct mcast_forw_if_entry *if_entry, *tmp_if_entry; + struct mcast_forw_nexthop_entry *nexthop_entry, *tmp_nexthop_entry; + + spin_lock_irqsave(&bat_priv->mcast_forw_table_lock, flags); + list_for_each_entry_safe(table_entry, tmp_table_entry, + &bat_priv->mcast_forw_table, list) { + list_for_each_entry_safe(orig_entry, tmp_orig_entry, + &table_entry->mcast_orig_list, list) { + list_for_each_entry_safe(if_entry, tmp_if_entry, + &orig_entry->mcast_if_list, list) { + list_for_each_entry_safe(nexthop_entry, + tmp_nexthop_entry, + &if_entry->mcast_nexthop_list, + list) { + if (get_remaining_timeout( + nexthop_entry, bat_priv)) + continue; + + list_del(&nexthop_entry->list); + kfree(nexthop_entry); + if_entry->num_nexthops--; + } + + if (!list_empty(&if_entry->mcast_nexthop_list)) + continue; + + list_del(&if_entry->list); + kfree(if_entry); + } + + if (!list_empty(&orig_entry->mcast_if_list)) + continue; + + list_del(&orig_entry->list); + kfree(orig_entry); + } + + if (!list_empty(&table_entry->mcast_orig_list)) + continue; + + list_del(&table_entry->list); + kfree(table_entry); + } + spin_unlock_irqrestore(&bat_priv->mcast_forw_table_lock, flags); +} + static void mcast_tracker_timer(struct work_struct *work) { struct bat_priv *bat_priv = container_of(work, struct bat_priv, diff --git a/multicast.h b/multicast.h index 0bd0590..7312afa 100644 --- a/multicast.h +++ b/multicast.h @@ -30,6 +30,7 @@ void mcast_tracker_reset(struct bat_priv *bat_priv); void route_mcast_tracker_packet( struct mcast_tracker_packet *tracker_packet, int tracker_packet_len, struct bat_priv *bat_priv); +void purge_mcast_forw_table(struct bat_priv *bat_priv); int mcast_forw_table_seq_print_text(struct seq_file *seq, void *offset); int mcast_init(struct bat_priv *bat_priv); void mcast_free(struct bat_priv *bat_priv); diff --git a/originator.c b/originator.c index 900d5fc..39ce8d5 100644 --- a/originator.c +++ b/originator.c @@ -30,6 +30,7 @@ #include "hard-interface.h" #include "unicast.h" #include "soft-interface.h" +#include "multicast.h"

static void purge_orig(struct work_struct *work);

@@ -311,6 +312,7 @@ static void purge_orig(struct work_struct *work) struct bat_priv *bat_priv = container_of(delayed_work, struct bat_priv, orig_work);

+ purge_mcast_forw_table(bat_priv); _purge_orig(bat_priv); start_purge_timer(bat_priv); }

This patch adds the capability to encapsulate and send a node's own multicast data packets. Based on the previously established multicast forwarding table, the sender can decide wheather it actually has to send the multicast data to one or more of its interfaces or not.

Furthermore, the sending procedure also decides whether to broadcast or unicast a multicast data packet to its next-hops, depending on the configured mcast_fanout (default: < 3 next hops on an interface, send seperate unicast packets).

Signed-off-by: Linus Lüssing linus.luessing@saxnet.de --- multicast.c | 133 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ multicast.h | 1 + soft-interface.c | 25 +++++++++-- types.h | 1 + 4 files changed, 156 insertions(+), 4 deletions(-)

diff --git a/multicast.c b/multicast.c index 2b1bfde..72249ef 100644 --- a/multicast.c +++ b/multicast.c @@ -23,6 +23,7 @@ #include "multicast.h" #include "hash.h" #include "send.h" +#include "soft-interface.h" #include "compat.h"

/* If auto mode for tracker timeout has been selected, @@ -1058,6 +1059,138 @@ int mcast_forw_table_seq_print_text(struct seq_file *seq, void *offset) return 0; }

+static void route_mcast_packet(struct sk_buff *skb, struct bat_priv *bat_priv) +{ + struct sk_buff *skb1; + struct mcast_packet *mcast_packet; + struct ethhdr *ethhdr; + struct batman_if *batman_if; + unsigned long flags; + struct mcast_forw_table_entry *table_entry; + struct mcast_forw_orig_entry *orig_entry; + struct mcast_forw_if_entry *if_entry; + struct mcast_forw_nexthop_entry *nexthop_entry; + int mcast_fanout = atomic_read(&bat_priv->mcast_fanout); + int num_bcasts = 3, i; + struct dest_entries_list dest_list, *dest_entry, *tmp; + + mcast_packet = (struct mcast_packet*)skb->data; + ethhdr = (struct ethhdr*)(mcast_packet + 1); + + INIT_LIST_HEAD(&dest_list.list); + + mcast_packet->ttl--; + + rcu_read_lock(); + spin_lock_irqsave(&bat_priv->mcast_forw_table_lock, flags); + list_for_each_entry(table_entry, &bat_priv->mcast_forw_table, list) { + if (memcmp(ethhdr->h_dest, table_entry->mcast_addr, ETH_ALEN)) + continue; + + list_for_each_entry(orig_entry, &table_entry->mcast_orig_list, + list) { + if (memcmp(mcast_packet->orig, + orig_entry->orig, ETH_ALEN)) + continue; + + list_for_each_entry(if_entry, + &orig_entry->mcast_if_list, list) { + batman_if = if_num_to_batman_if( + if_entry->if_num); + + /* send via broadcast */ + if (if_entry->num_nexthops > mcast_fanout) { + dest_entry = kmalloc(sizeof(struct + dest_entries_list), + GFP_ATOMIC); + memcpy(dest_entry->dest, + broadcast_addr, ETH_ALEN); + dest_entry->batman_if = batman_if; + list_add(&dest_entry->list, + &dest_list.list); + continue; + } + + /* send seperate unicast packets */ + list_for_each_entry(nexthop_entry, + &if_entry->mcast_nexthop_list, + list) { + if (!get_remaining_timeout( + nexthop_entry, + bat_priv)) + continue; + + dest_entry = kmalloc(sizeof(struct + dest_entries_list), + GFP_ATOMIC); + memcpy(dest_entry->dest, + nexthop_entry->neigh_addr, + ETH_ALEN); + dest_entry->batman_if = batman_if; + list_add(&dest_entry->list, + &dest_list.list); + } + } + break; + } + break; + } + spin_unlock_irqrestore(&bat_priv->mcast_forw_table_lock, flags); + + list_for_each_entry_safe (dest_entry, tmp, &dest_list.list, list) { + if (is_broadcast_ether_addr(dest_entry->dest)) { + for (i = 0; i < num_bcasts; i++) { + skb1 = skb_clone(skb, GFP_ATOMIC); + send_skb_packet(skb1, dest_entry->batman_if, + dest_entry->dest); + } + } else { + skb1 = skb_clone(skb, GFP_ATOMIC); + send_skb_packet(skb1, dest_entry->batman_if, + dest_entry->dest); + } + list_del(&dest_entry->list); + kfree(dest_entry); + } + rcu_read_unlock(); +} + +int mcast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv) +{ + struct mcast_packet *mcast_packet; + + if (!bat_priv->primary_if) + goto dropped; + + if (my_skb_head_push(skb, sizeof(struct mcast_packet)) < 0) + goto dropped; + + mcast_packet = (struct mcast_packet *)skb->data; + mcast_packet->version = COMPAT_VERSION; + mcast_packet->ttl = TTL; + + /* batman packet type: broadcast */ + mcast_packet->packet_type = BAT_MCAST; + + /* hw address of first interface is the orig mac because only + * this mac is known throughout the mesh */ + memcpy(mcast_packet->orig, + bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN); + + /* set broadcast sequence number */ + mcast_packet->seqno = + htonl(atomic_inc_return(&bat_priv->mcast_seqno)); + + route_mcast_packet(skb, bat_priv); + + kfree_skb(skb); + return 0; + +dropped: + kfree_skb(skb); + return 1; +} + int mcast_init(struct bat_priv *bat_priv) { INIT_DELAYED_WORK(&bat_priv->mcast_tracker_work, mcast_tracker_timer); diff --git a/multicast.h b/multicast.h index 7312afa..06dd398 100644 --- a/multicast.h +++ b/multicast.h @@ -32,6 +32,7 @@ void route_mcast_tracker_packet( int tracker_packet_len, struct bat_priv *bat_priv); void purge_mcast_forw_table(struct bat_priv *bat_priv); int mcast_forw_table_seq_print_text(struct seq_file *seq, void *offset); +int mcast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv); int mcast_init(struct bat_priv *bat_priv); void mcast_free(struct bat_priv *bat_priv);

diff --git a/soft-interface.c b/soft-interface.c index 7cea678..2a5a728 100644 --- a/soft-interface.c +++ b/soft-interface.c @@ -38,6 +38,7 @@ #include <linux/if_vlan.h> #include "unicast.h" #include "routing.h" +#include "multicast.h"

static int bat_get_settings(struct net_device *dev, struct ethtool_cmd *cmd); @@ -347,7 +348,7 @@ int interface_tx(struct sk_buff *skb, struct net_device *soft_iface) struct vlan_ethhdr *vhdr; int data_len = skb->len, ret; short vid = -1; - bool do_bcast = false; + bool bcast_dst = false, mcast_dst = false;

if (atomic_read(&bat_priv->mesh_state) != MESH_ACTIVE) goto dropped; @@ -384,12 +385,20 @@ int interface_tx(struct sk_buff *skb, struct net_device *soft_iface) if (ret < 0) goto dropped;

- if (ret == 0) - do_bcast = true; + /* dhcp request, which should be sent to the gateway directly? */ + if (ret) + goto unicast; + + if (is_broadcast_ether_addr(ethhdr->h_dest)) + bcast_dst = true; + else if (atomic_read(&bat_priv->mcast_mode) == MCAST_MODE_PROACT_TRACKING) + mcast_dst = true; + else + bcast_dst = true; }

/* ethernet packet should be broadcasted */ - if (do_bcast) { + if (bcast_dst) { if (!bat_priv->primary_if) goto dropped;

@@ -418,8 +427,15 @@ int interface_tx(struct sk_buff *skb, struct net_device *soft_iface) * the original skb. */ kfree_skb(skb);

+ /* multicast data with path optimization */ + } else if (mcast_dst) { + ret = mcast_send_skb(skb, bat_priv); + if (ret != 0) + goto dropped_freed; + /* unicast packet */ } else { +unicast: ret = unicast_send_skb(skb, bat_priv); if (ret != 0) goto dropped_freed; @@ -608,6 +624,7 @@ struct net_device *softif_create(char *name)

atomic_set(&bat_priv->mesh_state, MESH_INACTIVE); atomic_set(&bat_priv->bcast_seqno, 1); + atomic_set(&bat_priv->mcast_seqno, 1); atomic_set(&bat_priv->hna_local_changed, 0);

bat_priv->primary_if = NULL; diff --git a/types.h b/types.h index 17ccd5a..c12fd2c 100644 --- a/types.h +++ b/types.h @@ -140,6 +140,7 @@ struct bat_priv { atomic_t mcast_fanout; /* uint */ atomic_t log_level; /* uint */ atomic_t bcast_seqno; + atomic_t mcast_seqno; atomic_t bcast_queue_left; atomic_t batman_queue_left; char num_ifaces;

We need to check similar things for BAT_MCAST packets later too, therefore moving them to a seperate function.

Signed-off-by: Linus Lüssing linus.luessing@saxnet.de --- routing.c | 43 ++++++++++++++++++++++++++----------------- 1 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/routing.c b/routing.c index 9c83006..ff74bd1 100644 --- a/routing.c +++ b/routing.c @@ -1167,6 +1167,31 @@ static int check_unicast_packet(struct sk_buff *skb, int hdr_size) return 0; }

+static int check_broadcast_packet(struct sk_buff *skb, int hdr_size) +{ + struct ethhdr *ethhdr; + + /* drop packet if it has not necessary minimum size */ + if (unlikely(!pskb_may_pull(skb, hdr_size))) + return -1; + + ethhdr = (struct ethhdr *)skb_mac_header(skb); + + /* packet with broadcast indication but unicast recipient */ + if (!is_broadcast_ether_addr(ethhdr->h_dest)) + return -1; + + /* packet with broadcast sender address */ + if (is_broadcast_ether_addr(ethhdr->h_source)) + return -1; + + /* ignore broadcasts sent by myself */ + if (is_my_mac(ethhdr->h_source)) + return -1; + + return 0; +} + int route_unicast_packet(struct sk_buff *skb, struct batman_if *recv_if, int hdr_size) { @@ -1306,26 +1331,10 @@ int recv_bcast_packet(struct sk_buff *skb, struct batman_if *recv_if) struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface); struct orig_node *orig_node; struct bcast_packet *bcast_packet; - struct ethhdr *ethhdr; int hdr_size = sizeof(struct bcast_packet); int32_t seq_diff;

- /* drop packet if it has not necessary minimum size */ - if (unlikely(!pskb_may_pull(skb, hdr_size))) - return NET_RX_DROP; - - ethhdr = (struct ethhdr *)skb_mac_header(skb); - - /* packet with broadcast indication but unicast recipient */ - if (!is_broadcast_ether_addr(ethhdr->h_dest)) - return NET_RX_DROP; - - /* packet with broadcast sender address */ - if (is_broadcast_ether_addr(ethhdr->h_source)) - return NET_RX_DROP; - - /* ignore broadcasts sent by myself */ - if (is_my_mac(ethhdr->h_source)) + if (check_broadcast_packet(skb, hdr_size) < 0) return NET_RX_DROP;

bcast_packet = (struct bcast_packet *)skb->data;

This patch enables the forwarding of multicast data and uses the same methods for deciding to forward via broad- or unicast(s) as the local packet encapsulation already did.

Signed-off-by: Linus Lüssing linus.luessing@saxnet.de --- multicast.c | 2 +- multicast.h | 1 + routing.c | 4 ++++ 3 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/multicast.c b/multicast.c index 72249ef..042d392 100644 --- a/multicast.c +++ b/multicast.c @@ -1059,7 +1059,7 @@ int mcast_forw_table_seq_print_text(struct seq_file *seq, void *offset) return 0; }

-static void route_mcast_packet(struct sk_buff *skb, struct bat_priv *bat_priv) +void route_mcast_packet(struct sk_buff *skb, struct bat_priv *bat_priv) { struct sk_buff *skb1; struct mcast_packet *mcast_packet; diff --git a/multicast.h b/multicast.h index 06dd398..6dcf537 100644 --- a/multicast.h +++ b/multicast.h @@ -32,6 +32,7 @@ void route_mcast_tracker_packet( int tracker_packet_len, struct bat_priv *bat_priv); void purge_mcast_forw_table(struct bat_priv *bat_priv); int mcast_forw_table_seq_print_text(struct seq_file *seq, void *offset); +void route_mcast_packet(struct sk_buff *skb, struct bat_priv *bat_priv); int mcast_send_skb(struct sk_buff *skb, struct bat_priv *bat_priv); int mcast_init(struct bat_priv *bat_priv); void mcast_free(struct bat_priv *bat_priv); diff --git a/routing.c b/routing.c index b1aad26..f9582be 100644 --- a/routing.c +++ b/routing.c @@ -1390,6 +1390,7 @@ int recv_bcast_packet(struct sk_buff *skb, struct batman_if *recv_if)

int recv_mcast_packet(struct sk_buff *skb, struct batman_if *recv_if) { + struct bat_priv *bat_priv = netdev_priv(recv_if->soft_iface); struct ethhdr *ethhdr; MC_LIST *mc_entry; unsigned long flags; @@ -1401,6 +1402,9 @@ int recv_mcast_packet(struct sk_buff *skb, struct batman_if *recv_if) check_broadcast_packet(skb, hdr_size) < 0) return NET_RX_DROP;

+ /* forward multicast packet if necessary */ + route_mcast_packet(skb, bat_priv); + ethhdr = (struct ethhdr *)(skb->data + sizeof(struct mcast_packet));

/* multicast for me? */

We may only optimize the multicast packet flow, if an mcast_mode has been activated and if we are a multicast receiver of the same group. Otherwise flood the multicast packet without optimizations.

This allows us to still flood multicast packets of protocols where it is not easily possible for a multicast sender to be a multicast receiver of the same group instead of dropping them (for instance IPv6 NDP).

This commit therefore also makes IPv6 usable again, if the proact_tracking multicast mode has been activated.

Signed-off-by: Linus Lüssing linus.luessing@saxnet.de --- multicast.c | 25 +++++++++++++++++++++++++ multicast.h | 1 + soft-interface.c | 2 +- 3 files changed, 27 insertions(+), 1 deletions(-)

diff --git a/multicast.c b/multicast.c index 042d392..1f84f7c 100644 --- a/multicast.c +++ b/multicast.c @@ -107,6 +107,31 @@ void mcast_tracker_reset(struct bat_priv *bat_priv) start_mcast_tracker(bat_priv); }

+inline int mcast_may_optimize(uint8_t *dest, struct net_device *soft_iface) { + MC_LIST *mc_entry; + unsigned long flags; + struct bat_priv *bat_priv = netdev_priv(soft_iface); + int mcast_mode = atomic_read(&bat_priv->mcast_mode); + + if (mcast_mode != MCAST_MODE_PROACT_TRACKING) + return 0; + + /* Still allow flooding of multicast packets of protocols where it is + * not easily possible for a multicast sender to be a multicast + * receiver of the same group (for instance IPv6 NDP) */ + MC_LIST_LOCK(soft_iface, flags); + netdev_for_each_mc_addr(mc_entry, soft_iface) { + if (memcmp(dest, mc_entry->MC_LIST_ADDR, ETH_ALEN)) + continue; + + MC_LIST_UNLOCK(soft_iface, flags); + return 1; + } + MC_LIST_UNLOCK(soft_iface, flags); + + return 0; +} + static inline int get_remaining_timeout( struct mcast_forw_nexthop_entry *nexthop_entry, struct bat_priv *bat_priv) diff --git a/multicast.h b/multicast.h index 6dcf537..630a0ae 100644 --- a/multicast.h +++ b/multicast.h @@ -27,6 +27,7 @@ int mcast_tracker_interval_set(struct net_device *net_dev, char *buff, int mcast_tracker_timeout_set(struct net_device *net_dev, char *buff, size_t count); void mcast_tracker_reset(struct bat_priv *bat_priv); +int mcast_may_optimize(uint8_t *dest, struct net_device *soft_iface); void route_mcast_tracker_packet( struct mcast_tracker_packet *tracker_packet, int tracker_packet_len, struct bat_priv *bat_priv); diff --git a/soft-interface.c b/soft-interface.c index 2a5a728..444028d 100644 --- a/soft-interface.c +++ b/soft-interface.c @@ -391,7 +391,7 @@ int interface_tx(struct sk_buff *skb, struct net_device *soft_iface)

if (is_broadcast_ether_addr(ethhdr->h_dest)) bcast_dst = true; - else if (atomic_read(&bat_priv->mcast_mode) == MCAST_MODE_PROACT_TRACKING) + else if (mcast_may_optimize(ethhdr->h_dest, soft_iface)) mcast_dst = true; else bcast_dst = true;

Depending on the scenario, people might want to adjust the number of (re)broadcast of data packets - usually higher values in sparse or lower values in dense networks.

Signed-off-by: Linus Lüssing linus.luessing@saxnet.de --- bat_sysfs.c | 2 ++ send.c | 3 ++- types.h | 1 + 3 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/bat_sysfs.c b/bat_sysfs.c index 8f688db..7135c08 100644 --- a/bat_sysfs.c +++ b/bat_sysfs.c @@ -520,6 +520,7 @@ static BAT_ATTR(gw_mode, S_IRUGO | S_IWUSR, show_gw_mode, store_gw_mode); BAT_ATTR_UINT(orig_interval, S_IRUGO | S_IWUSR, 2 * JITTER, INT_MAX, update_mcast_tracker); BAT_ATTR_UINT(hop_penalty, S_IRUGO | S_IWUSR, 0, TQ_MAX_VALUE, NULL); +BAT_ATTR_UINT(num_bcasts, S_IRUGO | S_IWUSR, 0, INT_MAX, NULL); BAT_ATTR_UINT(gw_sel_class, S_IRUGO | S_IWUSR, 1, TQ_MAX_VALUE, post_gw_deselect); static BAT_ATTR(gw_bandwidth, S_IRUGO | S_IWUSR, show_gw_bwidth, @@ -544,6 +545,7 @@ static struct bat_attribute *mesh_attrs[] = { &bat_attr_gw_mode, &bat_attr_orig_interval, &bat_attr_hop_penalty, + &bat_attr_num_bcasts, &bat_attr_gw_sel_class, &bat_attr_gw_bandwidth, &bat_attr_mcast_mode, diff --git a/send.c b/send.c index ba7ebfe..26a6c99 100644 --- a/send.c +++ b/send.c @@ -512,6 +512,7 @@ static void send_outstanding_bcast_packet(struct work_struct *work) struct sk_buff *skb1; struct net_device *soft_iface = forw_packet->if_incoming->soft_iface; struct bat_priv *bat_priv = netdev_priv(soft_iface); + int num_bcasts = atomic_read(&bat_priv->num_bcasts);

spin_lock_bh(&bat_priv->forw_bcast_list_lock); hlist_del(&forw_packet->list); @@ -536,7 +537,7 @@ static void send_outstanding_bcast_packet(struct work_struct *work) forw_packet->num_packets++;

/* if we still have some more bcasts to send */ - if (forw_packet->num_packets < 3) { + if (forw_packet->num_packets < num_bcasts) { _add_bcast_packet_to_list(bat_priv, forw_packet, ((5 * HZ) / 1000)); return; diff --git a/types.h b/types.h index 890822f..938fc6d 100644 --- a/types.h +++ b/types.h @@ -137,6 +137,7 @@ struct bat_priv { atomic_t gw_bandwidth; /* gw bandwidth */ atomic_t orig_interval; /* uint */ atomic_t hop_penalty; /* uint */ + atomic_t num_bcasts; /* uint */ atomic_t mcast_mode; /* MCAST_MODE_* */ atomic_t mcast_tracker_interval;/* uint, auto */ atomic_t mcast_tracker_timeout; /* uint, auto */