diff options
Diffstat (limited to 'net/batman-adv/bat_v_ogm.c')
| -rw-r--r-- | net/batman-adv/bat_v_ogm.c | 1100 |
1 files changed, 1100 insertions, 0 deletions
diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c new file mode 100644 index 000000000..c451694fd --- /dev/null +++ b/net/batman-adv/bat_v_ogm.c @@ -0,0 +1,1100 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2013-2020 B.A.T.M.A.N. contributors: + * + * Antonio Quartulli + */ + +#include "bat_v_ogm.h" +#include "main.h" + +#include <linux/atomic.h> +#include <linux/byteorder/generic.h> +#include <linux/errno.h> +#include <linux/etherdevice.h> +#include <linux/gfp.h> +#include <linux/if_ether.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> +#include <linux/kref.h> +#include <linux/list.h> +#include <linux/lockdep.h> +#include <linux/mutex.h> +#include <linux/netdevice.h> +#include <linux/prandom.h> +#include <linux/random.h> +#include <linux/rculist.h> +#include <linux/rcupdate.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/stddef.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/workqueue.h> +#include <uapi/linux/batadv_packet.h> + +#include "bat_algo.h" +#include "hard-interface.h" +#include "hash.h" +#include "log.h" +#include "originator.h" +#include "routing.h" +#include "send.h" +#include "translation-table.h" +#include "tvlv.h" + +/** + * batadv_v_ogm_orig_get() - retrieve and possibly create an originator node + * @bat_priv: the bat priv with all the soft interface information + * @addr: the address of the originator + * + * Return: the orig_node corresponding to the specified address. If such an + * object does not exist, it is allocated here. In case of allocation failure + * returns NULL. + */ +struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv, + const u8 *addr) +{ + struct batadv_orig_node *orig_node; + int hash_added; + + orig_node = batadv_orig_hash_find(bat_priv, addr); + if (orig_node) + return orig_node; + + orig_node = batadv_orig_node_new(bat_priv, addr); + if (!orig_node) + return NULL; + + kref_get(&orig_node->refcount); + hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig, + batadv_choose_orig, orig_node, + &orig_node->hash_entry); + if (hash_added != 0) { + /* remove refcnt for newly created orig_node and hash entry */ + batadv_orig_node_put(orig_node); + batadv_orig_node_put(orig_node); + orig_node = NULL; + } + + return orig_node; +} + +/** + * batadv_v_ogm_start_queue_timer() - restart the OGM aggregation timer + * @hard_iface: the interface to use to send the OGM + */ +static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface) +{ + unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000; + + /* msecs * [0.9, 1.1] */ + msecs += prandom_u32_max(msecs / 5) - (msecs / 10); + queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq, + msecs_to_jiffies(msecs / 1000)); +} + +/** + * batadv_v_ogm_start_timer() - restart the OGM sending timer + * @bat_priv: the bat priv with all the soft interface information + */ +static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv) +{ + unsigned long msecs; + /* this function may be invoked in different contexts (ogm rescheduling + * or hard_iface activation), but the work timer should not be reset + */ + if (delayed_work_pending(&bat_priv->bat_v.ogm_wq)) + return; + + msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER; + msecs += prandom_u32_max(2 * BATADV_JITTER); + queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq, + msecs_to_jiffies(msecs)); +} + +/** + * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface + * @skb: the OGM to send + * @hard_iface: the interface to use to send the OGM + */ +static void batadv_v_ogm_send_to_if(struct sk_buff *skb, + struct batadv_hard_iface *hard_iface) +{ + struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); + + if (hard_iface->if_status != BATADV_IF_ACTIVE) { + kfree_skb(skb); + return; + } + + batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX); + batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES, + skb->len + ETH_HLEN); + + batadv_send_broadcast_skb(skb, hard_iface); +} + +/** + * batadv_v_ogm_len() - OGMv2 packet length + * @skb: the OGM to check + * + * Return: Length of the given OGMv2 packet, including tvlv length, excluding + * ethernet header length. + */ +static unsigned int batadv_v_ogm_len(struct sk_buff *skb) +{ + struct batadv_ogm2_packet *ogm_packet; + + ogm_packet = (struct batadv_ogm2_packet *)skb->data; + return BATADV_OGM2_HLEN + ntohs(ogm_packet->tvlv_len); +} + +/** + * batadv_v_ogm_queue_left() - check if given OGM still fits aggregation queue + * @skb: the OGM to check + * @hard_iface: the interface to use to send the OGM + * + * Caller needs to hold the hard_iface->bat_v.aggr_list.lock. + * + * Return: True, if the given OGMv2 packet still fits, false otherwise. + */ +static bool batadv_v_ogm_queue_left(struct sk_buff *skb, + struct batadv_hard_iface *hard_iface) +{ + unsigned int max = min_t(unsigned int, hard_iface->net_dev->mtu, + BATADV_MAX_AGGREGATION_BYTES); + unsigned int ogm_len = batadv_v_ogm_len(skb); + + lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock); + + return hard_iface->bat_v.aggr_len + ogm_len <= max; +} + +/** + * batadv_v_ogm_aggr_list_free - free all elements in an aggregation queue + * @hard_iface: the interface holding the aggregation queue + * + * Empties the OGMv2 aggregation queue and frees all the skbs it contains. + * + * Caller needs to hold the hard_iface->bat_v.aggr_list.lock. + */ +static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface) +{ + lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock); + + __skb_queue_purge(&hard_iface->bat_v.aggr_list); + hard_iface->bat_v.aggr_len = 0; +} + +/** + * batadv_v_ogm_aggr_send() - flush & send aggregation queue + * @hard_iface: the interface with the aggregation queue to flush + * + * Aggregates all OGMv2 packets currently in the aggregation queue into a + * single OGMv2 packet and transmits this aggregate. + * + * The aggregation queue is empty after this call. + * + * Caller needs to hold the hard_iface->bat_v.aggr_list.lock. + */ +static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface) +{ + unsigned int aggr_len = hard_iface->bat_v.aggr_len; + struct sk_buff *skb_aggr; + unsigned int ogm_len; + struct sk_buff *skb; + + lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock); + + if (!aggr_len) + return; + + skb_aggr = dev_alloc_skb(aggr_len + ETH_HLEN + NET_IP_ALIGN); + if (!skb_aggr) { + batadv_v_ogm_aggr_list_free(hard_iface); + return; + } + + skb_reserve(skb_aggr, ETH_HLEN + NET_IP_ALIGN); + skb_reset_network_header(skb_aggr); + + while ((skb = __skb_dequeue(&hard_iface->bat_v.aggr_list))) { + hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb); + + ogm_len = batadv_v_ogm_len(skb); + skb_put_data(skb_aggr, skb->data, ogm_len); + + consume_skb(skb); + } + + batadv_v_ogm_send_to_if(skb_aggr, hard_iface); +} + +/** + * batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface + * @skb: the OGM to queue + * @hard_iface: the interface to queue the OGM on + */ +static void batadv_v_ogm_queue_on_if(struct sk_buff *skb, + struct batadv_hard_iface *hard_iface) +{ + struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); + + if (!atomic_read(&bat_priv->aggregated_ogms)) { + batadv_v_ogm_send_to_if(skb, hard_iface); + return; + } + + spin_lock_bh(&hard_iface->bat_v.aggr_list.lock); + if (!batadv_v_ogm_queue_left(skb, hard_iface)) + batadv_v_ogm_aggr_send(hard_iface); + + hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb); + __skb_queue_tail(&hard_iface->bat_v.aggr_list, skb); + spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock); +} + +/** + * batadv_v_ogm_send_softif() - periodic worker broadcasting the own OGM + * @bat_priv: the bat priv with all the soft interface information + */ +static void batadv_v_ogm_send_softif(struct batadv_priv *bat_priv) +{ + struct batadv_hard_iface *hard_iface; + struct batadv_ogm2_packet *ogm_packet; + struct sk_buff *skb, *skb_tmp; + unsigned char *ogm_buff; + int ogm_buff_len; + u16 tvlv_len = 0; + int ret; + + lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex); + + if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) + goto out; + + ogm_buff = bat_priv->bat_v.ogm_buff; + ogm_buff_len = bat_priv->bat_v.ogm_buff_len; + /* tt changes have to be committed before the tvlv data is + * appended as it may alter the tt tvlv container + */ + batadv_tt_local_commit_changes(bat_priv); + tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff, + &ogm_buff_len, + BATADV_OGM2_HLEN); + + bat_priv->bat_v.ogm_buff = ogm_buff; + bat_priv->bat_v.ogm_buff_len = ogm_buff_len; + + skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len); + if (!skb) + goto reschedule; + + skb_reserve(skb, ETH_HLEN); + skb_put_data(skb, ogm_buff, ogm_buff_len); + + ogm_packet = (struct batadv_ogm2_packet *)skb->data; + ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno)); + atomic_inc(&bat_priv->bat_v.ogm_seqno); + ogm_packet->tvlv_len = htons(tvlv_len); + + /* broadcast on every interface */ + rcu_read_lock(); + list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { + if (hard_iface->soft_iface != bat_priv->soft_iface) + continue; + + if (!kref_get_unless_zero(&hard_iface->refcount)) + continue; + + ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL); + if (ret) { + char *type; + + switch (ret) { + case BATADV_HARDIF_BCAST_NORECIPIENT: + type = "no neighbor"; + break; + case BATADV_HARDIF_BCAST_DUPFWD: + type = "single neighbor is source"; + break; + case BATADV_HARDIF_BCAST_DUPORIG: + type = "single neighbor is originator"; + break; + default: + type = "unknown"; + } + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n", + hard_iface->net_dev->name, type); + + batadv_hardif_put(hard_iface); + continue; + } + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n", + ogm_packet->orig, ntohl(ogm_packet->seqno), + ntohl(ogm_packet->throughput), ogm_packet->ttl, + hard_iface->net_dev->name, + hard_iface->net_dev->dev_addr); + + /* this skb gets consumed by batadv_v_ogm_send_to_if() */ + skb_tmp = skb_clone(skb, GFP_ATOMIC); + if (!skb_tmp) { + batadv_hardif_put(hard_iface); + break; + } + + batadv_v_ogm_queue_on_if(skb_tmp, hard_iface); + batadv_hardif_put(hard_iface); + } + rcu_read_unlock(); + + consume_skb(skb); + +reschedule: + batadv_v_ogm_start_timer(bat_priv); +out: + return; +} + +/** + * batadv_v_ogm_send() - periodic worker broadcasting the own OGM + * @work: work queue item + */ +static void batadv_v_ogm_send(struct work_struct *work) +{ + struct batadv_priv_bat_v *bat_v; + struct batadv_priv *bat_priv; + + bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work); + bat_priv = container_of(bat_v, struct batadv_priv, bat_v); + + mutex_lock(&bat_priv->bat_v.ogm_buff_mutex); + batadv_v_ogm_send_softif(bat_priv); + mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex); +} + +/** + * batadv_v_ogm_aggr_work() - OGM queue periodic task per interface + * @work: work queue item + * + * Emits aggregated OGM messages in regular intervals. + */ +void batadv_v_ogm_aggr_work(struct work_struct *work) +{ + struct batadv_hard_iface_bat_v *batv; + struct batadv_hard_iface *hard_iface; + + batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work); + hard_iface = container_of(batv, struct batadv_hard_iface, bat_v); + + spin_lock_bh(&hard_iface->bat_v.aggr_list.lock); + batadv_v_ogm_aggr_send(hard_iface); + spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock); + + batadv_v_ogm_start_queue_timer(hard_iface); +} + +/** + * batadv_v_ogm_iface_enable() - prepare an interface for B.A.T.M.A.N. V + * @hard_iface: the interface to prepare + * + * Takes care of scheduling its own OGM sending routine for this interface. + * + * Return: 0 on success or a negative error code otherwise + */ +int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface) +{ + struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); + + batadv_v_ogm_start_queue_timer(hard_iface); + batadv_v_ogm_start_timer(bat_priv); + + return 0; +} + +/** + * batadv_v_ogm_iface_disable() - release OGM interface private resources + * @hard_iface: interface for which the resources have to be released + */ +void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface) +{ + cancel_delayed_work_sync(&hard_iface->bat_v.aggr_wq); + + spin_lock_bh(&hard_iface->bat_v.aggr_list.lock); + batadv_v_ogm_aggr_list_free(hard_iface); + spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock); +} + +/** + * batadv_v_ogm_primary_iface_set() - set a new primary interface + * @primary_iface: the new primary interface + */ +void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface) +{ + struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface); + struct batadv_ogm2_packet *ogm_packet; + + mutex_lock(&bat_priv->bat_v.ogm_buff_mutex); + if (!bat_priv->bat_v.ogm_buff) + goto unlock; + + ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff; + ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr); + +unlock: + mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex); +} + +/** + * batadv_v_forward_penalty() - apply a penalty to the throughput metric + * forwarded with B.A.T.M.A.N. V OGMs + * @bat_priv: the bat priv with all the soft interface information + * @if_incoming: the interface where the OGM has been received + * @if_outgoing: the interface where the OGM has to be forwarded to + * @throughput: the current throughput + * + * Apply a penalty on the current throughput metric value based on the + * characteristic of the interface where the OGM has been received. + * + * Initially the per hardif hop penalty is applied to the throughput. After + * that the return value is then computed as follows: + * - throughput * 50% if the incoming and outgoing interface are the + * same WiFi interface and the throughput is above + * 1MBit/s + * - throughput if the outgoing interface is the default + * interface (i.e. this OGM is processed for the + * internal table and not forwarded) + * - throughput * node hop penalty otherwise + * + * Return: the penalised throughput metric. + */ +static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv, + struct batadv_hard_iface *if_incoming, + struct batadv_hard_iface *if_outgoing, + u32 throughput) +{ + int if_hop_penalty = atomic_read(&if_incoming->hop_penalty); + int hop_penalty = atomic_read(&bat_priv->hop_penalty); + int hop_penalty_max = BATADV_TQ_MAX_VALUE; + + /* Apply per hardif hop penalty */ + throughput = throughput * (hop_penalty_max - if_hop_penalty) / + hop_penalty_max; + + /* Don't apply hop penalty in default originator table. */ + if (if_outgoing == BATADV_IF_DEFAULT) + return throughput; + + /* Forwarding on the same WiFi interface cuts the throughput in half + * due to the store & forward characteristics of WIFI. + * Very low throughput values are the exception. + */ + if (throughput > 10 && + if_incoming == if_outgoing && + !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX)) + return throughput / 2; + + /* hop penalty of 255 equals 100% */ + return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max; +} + +/** + * batadv_v_ogm_forward() - check conditions and forward an OGM to the given + * outgoing interface + * @bat_priv: the bat priv with all the soft interface information + * @ogm_received: previously received OGM to be forwarded + * @orig_node: the originator which has been updated + * @neigh_node: the neigh_node through with the OGM has been received + * @if_incoming: the interface on which this OGM was received on + * @if_outgoing: the interface to which the OGM has to be forwarded to + * + * Forward an OGM to an interface after having altered the throughput metric and + * the TTL value contained in it. The original OGM isn't modified. + */ +static void batadv_v_ogm_forward(struct batadv_priv *bat_priv, + const struct batadv_ogm2_packet *ogm_received, + struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node, + struct batadv_hard_iface *if_incoming, + struct batadv_hard_iface *if_outgoing) +{ + struct batadv_neigh_ifinfo *neigh_ifinfo = NULL; + struct batadv_orig_ifinfo *orig_ifinfo = NULL; + struct batadv_neigh_node *router = NULL; + struct batadv_ogm2_packet *ogm_forward; + unsigned char *skb_buff; + struct sk_buff *skb; + size_t packet_len; + u16 tvlv_len; + + /* only forward for specific interfaces, not for the default one. */ + if (if_outgoing == BATADV_IF_DEFAULT) + goto out; + + orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing); + if (!orig_ifinfo) + goto out; + + /* acquire possibly updated router */ + router = batadv_orig_router_get(orig_node, if_outgoing); + + /* strict rule: forward packets coming from the best next hop only */ + if (neigh_node != router) + goto out; + + /* don't forward the same seqno twice on one interface */ + if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno)) + goto out; + + orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno); + + if (ogm_received->ttl <= 1) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n"); + goto out; + } + + neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing); + if (!neigh_ifinfo) + goto out; + + tvlv_len = ntohs(ogm_received->tvlv_len); + + packet_len = BATADV_OGM2_HLEN + tvlv_len; + skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev, + ETH_HLEN + packet_len); + if (!skb) + goto out; + + skb_reserve(skb, ETH_HLEN); + skb_buff = skb_put_data(skb, ogm_received, packet_len); + + /* apply forward penalty */ + ogm_forward = (struct batadv_ogm2_packet *)skb_buff; + ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput); + ogm_forward->ttl--; + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n", + if_outgoing->net_dev->name, ntohl(ogm_forward->throughput), + ogm_forward->ttl, if_incoming->net_dev->name); + + batadv_v_ogm_queue_on_if(skb, if_outgoing); + +out: + if (orig_ifinfo) + batadv_orig_ifinfo_put(orig_ifinfo); + if (router) + batadv_neigh_node_put(router); + if (neigh_ifinfo) + batadv_neigh_ifinfo_put(neigh_ifinfo); +} + +/** + * batadv_v_ogm_metric_update() - update route metric based on OGM + * @bat_priv: the bat priv with all the soft interface information + * @ogm2: OGM2 structure + * @orig_node: Originator structure for which the OGM has been received + * @neigh_node: the neigh_node through with the OGM has been received + * @if_incoming: the interface where this packet was received + * @if_outgoing: the interface for which the packet should be considered + * + * Return: + * 1 if the OGM is new, + * 0 if it is not new but valid, + * <0 on error (e.g. old OGM) + */ +static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv, + const struct batadv_ogm2_packet *ogm2, + struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node, + struct batadv_hard_iface *if_incoming, + struct batadv_hard_iface *if_outgoing) +{ + struct batadv_orig_ifinfo *orig_ifinfo; + struct batadv_neigh_ifinfo *neigh_ifinfo = NULL; + bool protection_started = false; + int ret = -EINVAL; + u32 path_throughput; + s32 seq_diff; + + orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing); + if (!orig_ifinfo) + goto out; + + seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno; + + if (!hlist_empty(&orig_node->neigh_list) && + batadv_window_protected(bat_priv, seq_diff, + BATADV_OGM_MAX_AGE, + &orig_ifinfo->batman_seqno_reset, + &protection_started)) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Drop packet: packet within window protection time from %pM\n", + ogm2->orig); + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Last reset: %ld, %ld\n", + orig_ifinfo->batman_seqno_reset, jiffies); + goto out; + } + + /* drop packets with old seqnos, however accept the first packet after + * a host has been rebooted. + */ + if (seq_diff < 0 && !protection_started) + goto out; + + neigh_node->last_seen = jiffies; + + orig_node->last_seen = jiffies; + + orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno); + orig_ifinfo->last_ttl = ogm2->ttl; + + neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing); + if (!neigh_ifinfo) + goto out; + + path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming, + if_outgoing, + ntohl(ogm2->throughput)); + neigh_ifinfo->bat_v.throughput = path_throughput; + neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno); + neigh_ifinfo->last_ttl = ogm2->ttl; + + if (seq_diff > 0 || protection_started) + ret = 1; + else + ret = 0; +out: + if (orig_ifinfo) + batadv_orig_ifinfo_put(orig_ifinfo); + if (neigh_ifinfo) + batadv_neigh_ifinfo_put(neigh_ifinfo); + + return ret; +} + +/** + * batadv_v_ogm_route_update() - update routes based on OGM + * @bat_priv: the bat priv with all the soft interface information + * @ethhdr: the Ethernet header of the OGM2 + * @ogm2: OGM2 structure + * @orig_node: Originator structure for which the OGM has been received + * @neigh_node: the neigh_node through with the OGM has been received + * @if_incoming: the interface where this packet was received + * @if_outgoing: the interface for which the packet should be considered + * + * Return: true if the packet should be forwarded, false otherwise + */ +static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv, + const struct ethhdr *ethhdr, + const struct batadv_ogm2_packet *ogm2, + struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node, + struct batadv_hard_iface *if_incoming, + struct batadv_hard_iface *if_outgoing) +{ + struct batadv_neigh_node *router = NULL; + struct batadv_orig_node *orig_neigh_node; + struct batadv_neigh_node *orig_neigh_router = NULL; + struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL; + u32 router_throughput, neigh_throughput; + u32 router_last_seqno; + u32 neigh_last_seqno; + s32 neigh_seq_diff; + bool forward = false; + + orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source); + if (!orig_neigh_node) + goto out; + + orig_neigh_router = batadv_orig_router_get(orig_neigh_node, + if_outgoing); + + /* drop packet if sender is not a direct neighbor and if we + * don't route towards it + */ + router = batadv_orig_router_get(orig_node, if_outgoing); + if (router && router->orig_node != orig_node && !orig_neigh_router) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Drop packet: OGM via unknown neighbor!\n"); + goto out; + } + + /* Mark the OGM to be considered for forwarding, and update routes + * if needed. + */ + forward = true; + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Searching and updating originator entry of received packet\n"); + + /* if this neighbor already is our next hop there is nothing + * to change + */ + if (router == neigh_node) + goto out; + + /* don't consider neighbours with worse throughput. + * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than + * the last received seqno from our best next hop. + */ + if (router) { + router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing); + neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing); + + /* if these are not allocated, something is wrong. */ + if (!router_ifinfo || !neigh_ifinfo) + goto out; + + neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno; + router_last_seqno = router_ifinfo->bat_v.last_seqno; + neigh_seq_diff = neigh_last_seqno - router_last_seqno; + router_throughput = router_ifinfo->bat_v.throughput; + neigh_throughput = neigh_ifinfo->bat_v.throughput; + + if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF && + router_throughput >= neigh_throughput) + goto out; + } + + batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node); +out: + if (router) + batadv_neigh_node_put(router); + if (orig_neigh_router) + batadv_neigh_node_put(orig_neigh_router); + if (orig_neigh_node) + batadv_orig_node_put(orig_neigh_node); + if (router_ifinfo) + batadv_neigh_ifinfo_put(router_ifinfo); + if (neigh_ifinfo) + batadv_neigh_ifinfo_put(neigh_ifinfo); + + return forward; +} + +/** + * batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if + * @bat_priv: the bat priv with all the soft interface information + * @ethhdr: the Ethernet header of the OGM2 + * @ogm2: OGM2 structure + * @orig_node: Originator structure for which the OGM has been received + * @neigh_node: the neigh_node through with the OGM has been received + * @if_incoming: the interface where this packet was received + * @if_outgoing: the interface for which the packet should be considered + */ +static void +batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv, + const struct ethhdr *ethhdr, + const struct batadv_ogm2_packet *ogm2, + struct batadv_orig_node *orig_node, + struct batadv_neigh_node *neigh_node, + struct batadv_hard_iface *if_incoming, + struct batadv_hard_iface *if_outgoing) +{ + int seqno_age; + bool forward; + + /* first, update the metric with according sanity checks */ + seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node, + neigh_node, if_incoming, + if_outgoing); + + /* outdated sequence numbers are to be discarded */ + if (seqno_age < 0) + return; + + /* only unknown & newer OGMs contain TVLVs we are interested in */ + if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT) + batadv_tvlv_containers_process(bat_priv, true, orig_node, + NULL, NULL, + (unsigned char *)(ogm2 + 1), + ntohs(ogm2->tvlv_len)); + + /* if the metric update went through, update routes if needed */ + forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node, + neigh_node, if_incoming, + if_outgoing); + + /* if the routes have been processed correctly, check and forward */ + if (forward) + batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node, + if_incoming, if_outgoing); +} + +/** + * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated + * @buff_pos: current position in the skb + * @packet_len: total length of the skb + * @ogm2_packet: potential OGM2 in buffer + * + * Return: true if there is enough space for another OGM, false otherwise. + */ +static bool +batadv_v_ogm_aggr_packet(int buff_pos, int packet_len, + const struct batadv_ogm2_packet *ogm2_packet) +{ + int next_buff_pos = 0; + + /* check if there is enough space for the header */ + next_buff_pos += buff_pos + sizeof(*ogm2_packet); + if (next_buff_pos > packet_len) + return false; + + /* check if there is enough space for the optional TVLV */ + next_buff_pos += ntohs(ogm2_packet->tvlv_len); + + return (next_buff_pos <= packet_len) && + (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES); +} + +/** + * batadv_v_ogm_process() - process an incoming batman v OGM + * @skb: the skb containing the OGM + * @ogm_offset: offset to the OGM which should be processed (for aggregates) + * @if_incoming: the interface where this packet was received + */ +static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset, + struct batadv_hard_iface *if_incoming) +{ + struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface); + struct ethhdr *ethhdr; + struct batadv_orig_node *orig_node = NULL; + struct batadv_hardif_neigh_node *hardif_neigh = NULL; + struct batadv_neigh_node *neigh_node = NULL; + struct batadv_hard_iface *hard_iface; + struct batadv_ogm2_packet *ogm_packet; + u32 ogm_throughput, link_throughput, path_throughput; + int ret; + + ethhdr = eth_hdr(skb); + ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset); + + ogm_throughput = ntohl(ogm_packet->throughput); + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n", + ethhdr->h_source, if_incoming->net_dev->name, + if_incoming->net_dev->dev_addr, ogm_packet->orig, + ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl, + ogm_packet->version, ntohs(ogm_packet->tvlv_len)); + + if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Drop packet: originator packet from ourself\n"); + return; + } + + /* If the throughput metric is 0, immediately drop the packet. No need + * to create orig_node / neigh_node for an unusable route. + */ + if (ogm_throughput == 0) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Drop packet: originator packet with throughput metric of 0\n"); + return; + } + + /* require ELP packets be to received from this neighbor first */ + hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source); + if (!hardif_neigh) { + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "Drop packet: OGM via unknown neighbor!\n"); + goto out; + } + + orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig); + if (!orig_node) + goto out; + + neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming, + ethhdr->h_source); + if (!neigh_node) + goto out; + + /* Update the received throughput metric to match the link + * characteristic: + * - If this OGM traveled one hop so far (emitted by single hop + * neighbor) the path throughput metric equals the link throughput. + * - For OGMs traversing more than hop the path throughput metric is + * the smaller of the path throughput and the link throughput. + */ + link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput); + path_throughput = min_t(u32, link_throughput, ogm_throughput); + ogm_packet->throughput = htonl(path_throughput); + + batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node, + neigh_node, if_incoming, + BATADV_IF_DEFAULT); + + rcu_read_lock(); + list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { + if (hard_iface->if_status != BATADV_IF_ACTIVE) + continue; + + if (hard_iface->soft_iface != bat_priv->soft_iface) + continue; + + if (!kref_get_unless_zero(&hard_iface->refcount)) + continue; + + ret = batadv_hardif_no_broadcast(hard_iface, + ogm_packet->orig, + hardif_neigh->orig); + + if (ret) { + char *type; + + switch (ret) { + case BATADV_HARDIF_BCAST_NORECIPIENT: + type = "no neighbor"; + break; + case BATADV_HARDIF_BCAST_DUPFWD: + type = "single neighbor is source"; + break; + case BATADV_HARDIF_BCAST_DUPORIG: + type = "single neighbor is originator"; + break; + default: + type = "unknown"; + } + + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n", + ogm_packet->orig, hard_iface->net_dev->name, + type); + + batadv_hardif_put(hard_iface); + continue; + } + + batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, + orig_node, neigh_node, + if_incoming, hard_iface); + + batadv_hardif_put(hard_iface); + } + rcu_read_unlock(); +out: + if (orig_node) + batadv_orig_node_put(orig_node); + if (neigh_node) + batadv_neigh_node_put(neigh_node); + if (hardif_neigh) + batadv_hardif_neigh_put(hardif_neigh); +} + +/** + * batadv_v_ogm_packet_recv() - OGM2 receiving handler + * @skb: the received OGM + * @if_incoming: the interface where this OGM has been received + * + * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP + * (without freeing the skb) on failure + */ +int batadv_v_ogm_packet_recv(struct sk_buff *skb, + struct batadv_hard_iface *if_incoming) +{ + struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface); + struct batadv_ogm2_packet *ogm_packet; + struct ethhdr *ethhdr; + int ogm_offset; + u8 *packet_pos; + int ret = NET_RX_DROP; + + /* did we receive a OGM2 packet on an interface that does not have + * B.A.T.M.A.N. V enabled ? + */ + if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0) + goto free_skb; + + if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN)) + goto free_skb; + + ethhdr = eth_hdr(skb); + if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) + goto free_skb; + + batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX); + batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES, + skb->len + ETH_HLEN); + + ogm_offset = 0; + ogm_packet = (struct batadv_ogm2_packet *)skb->data; + + while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb), + ogm_packet)) { + batadv_v_ogm_process(skb, ogm_offset, if_incoming); + + ogm_offset += BATADV_OGM2_HLEN; + ogm_offset += ntohs(ogm_packet->tvlv_len); + + packet_pos = skb->data + ogm_offset; + ogm_packet = (struct batadv_ogm2_packet *)packet_pos; + } + + ret = NET_RX_SUCCESS; + +free_skb: + if (ret == NET_RX_SUCCESS) + consume_skb(skb); + else + kfree_skb(skb); + + return ret; +} + +/** + * batadv_v_ogm_init() - initialise the OGM2 engine + * @bat_priv: the bat priv with all the soft interface information + * + * Return: 0 on success or a negative error code in case of failure + */ +int batadv_v_ogm_init(struct batadv_priv *bat_priv) +{ + struct batadv_ogm2_packet *ogm_packet; + unsigned char *ogm_buff; + u32 random_seqno; + + bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN; + ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC); + if (!ogm_buff) + return -ENOMEM; + + bat_priv->bat_v.ogm_buff = ogm_buff; + ogm_packet = (struct batadv_ogm2_packet *)ogm_buff; + ogm_packet->packet_type = BATADV_OGM2; + ogm_packet->version = BATADV_COMPAT_VERSION; + ogm_packet->ttl = BATADV_TTL; + ogm_packet->flags = BATADV_NO_FLAGS; + ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE); + + /* randomize initial seqno to avoid collision */ + get_random_bytes(&random_seqno, sizeof(random_seqno)); + atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno); + INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send); + + mutex_init(&bat_priv->bat_v.ogm_buff_mutex); + + return 0; +} + +/** + * batadv_v_ogm_free() - free OGM private resources + * @bat_priv: the bat priv with all the soft interface information + */ +void batadv_v_ogm_free(struct batadv_priv *bat_priv) +{ + cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq); + + mutex_lock(&bat_priv->bat_v.ogm_buff_mutex); + + kfree(bat_priv->bat_v.ogm_buff); + bat_priv->bat_v.ogm_buff = NULL; + bat_priv->bat_v.ogm_buff_len = 0; + + mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex); +} |