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- // 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)
- 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 = eth_hdr(skb);
- 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;
- 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);
- }
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