| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (C) 2011-2020 B.A.T.M.A.N. contributors: |
| * |
| * Linus Lüssing, Marek Lindner |
| */ |
| |
| #include "bat_v_elp.h" |
| #include "main.h" |
| |
| #include <linux/atomic.h> |
| #include <linux/bitops.h> |
| #include <linux/byteorder/generic.h> |
| #include <linux/errno.h> |
| #include <linux/etherdevice.h> |
| #include <linux/ethtool.h> |
| #include <linux/gfp.h> |
| #include <linux/if_ether.h> |
| #include <linux/jiffies.h> |
| #include <linux/kernel.h> |
| #include <linux/kref.h> |
| #include <linux/netdevice.h> |
| #include <linux/nl80211.h> |
| #include <linux/random.h> |
| #include <linux/rculist.h> |
| #include <linux/rcupdate.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/skbuff.h> |
| #include <linux/stddef.h> |
| #include <linux/string.h> |
| #include <linux/types.h> |
| #include <linux/workqueue.h> |
| #include <net/cfg80211.h> |
| #include <uapi/linux/batadv_packet.h> |
| |
| #include "bat_algo.h" |
| #include "bat_v_ogm.h" |
| #include "hard-interface.h" |
| #include "log.h" |
| #include "originator.h" |
| #include "routing.h" |
| #include "send.h" |
| |
| /** |
| * batadv_v_elp_start_timer() - restart timer for ELP periodic work |
| * @hard_iface: the interface for which the timer has to be reset |
| */ |
| static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface) |
| { |
| unsigned int msecs; |
| |
| msecs = atomic_read(&hard_iface->bat_v.elp_interval) - BATADV_JITTER; |
| msecs += prandom_u32() % (2 * BATADV_JITTER); |
| |
| queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.elp_wq, |
| msecs_to_jiffies(msecs)); |
| } |
| |
| /** |
| * batadv_v_elp_get_throughput() - get the throughput towards a neighbour |
| * @neigh: the neighbour for which the throughput has to be obtained |
| * |
| * Return: The throughput towards the given neighbour in multiples of 100kpbs |
| * (a value of '1' equals to 0.1Mbps, '10' equals 1Mbps, etc). |
| */ |
| static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh) |
| { |
| struct batadv_hard_iface *hard_iface = neigh->if_incoming; |
| struct ethtool_link_ksettings link_settings; |
| struct net_device *real_netdev; |
| struct station_info sinfo; |
| u32 throughput; |
| int ret; |
| |
| /* if the user specified a customised value for this interface, then |
| * return it directly |
| */ |
| throughput = atomic_read(&hard_iface->bat_v.throughput_override); |
| if (throughput != 0) |
| return throughput; |
| |
| /* if this is a wireless device, then ask its throughput through |
| * cfg80211 API |
| */ |
| if (batadv_is_wifi_hardif(hard_iface)) { |
| if (!batadv_is_cfg80211_hardif(hard_iface)) |
| /* unsupported WiFi driver version */ |
| goto default_throughput; |
| |
| real_netdev = batadv_get_real_netdev(hard_iface->net_dev); |
| if (!real_netdev) |
| goto default_throughput; |
| |
| ret = cfg80211_get_station(real_netdev, neigh->addr, &sinfo); |
| |
| if (!ret) { |
| /* free the TID stats immediately */ |
| cfg80211_sinfo_release_content(&sinfo); |
| } |
| |
| dev_put(real_netdev); |
| if (ret == -ENOENT) { |
| /* Node is not associated anymore! It would be |
| * possible to delete this neighbor. For now set |
| * the throughput metric to 0. |
| */ |
| return 0; |
| } |
| if (ret) |
| goto default_throughput; |
| |
| if (sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)) |
| return sinfo.expected_throughput / 100; |
| |
| /* try to estimate the expected throughput based on reported tx |
| * rates |
| */ |
| if (sinfo.filled & BIT(NL80211_STA_INFO_TX_BITRATE)) |
| return cfg80211_calculate_bitrate(&sinfo.txrate) / 3; |
| |
| goto default_throughput; |
| } |
| |
| /* if not a wifi interface, check if this device provides data via |
| * ethtool (e.g. an Ethernet adapter) |
| */ |
| memset(&link_settings, 0, sizeof(link_settings)); |
| rtnl_lock(); |
| ret = __ethtool_get_link_ksettings(hard_iface->net_dev, &link_settings); |
| rtnl_unlock(); |
| |
| /* Virtual interface drivers such as tun / tap interfaces, VLAN, etc |
| * tend to initialize the interface throughput with some value for the |
| * sake of having a throughput number to export via ethtool. This |
| * exported throughput leaves batman-adv to conclude the interface |
| * throughput is genuine (reflecting reality), thus no measurements |
| * are necessary. |
| * |
| * Based on the observation that those interface types also tend to set |
| * the link auto-negotiation to 'off', batman-adv shall check this |
| * setting to differentiate between genuine link throughput information |
| * and placeholders installed by virtual interfaces. |
| */ |
| if (ret == 0 && link_settings.base.autoneg == AUTONEG_ENABLE) { |
| /* link characteristics might change over time */ |
| if (link_settings.base.duplex == DUPLEX_FULL) |
| hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX; |
| else |
| hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX; |
| |
| throughput = link_settings.base.speed; |
| if (throughput && throughput != SPEED_UNKNOWN) |
| return throughput * 10; |
| } |
| |
| default_throughput: |
| if (!(hard_iface->bat_v.flags & BATADV_WARNING_DEFAULT)) { |
| batadv_info(hard_iface->soft_iface, |
| "WiFi driver or ethtool info does not provide information about link speeds on interface %s, therefore defaulting to hardcoded throughput values of %u.%1u Mbps. Consider overriding the throughput manually or checking your driver.\n", |
| hard_iface->net_dev->name, |
| BATADV_THROUGHPUT_DEFAULT_VALUE / 10, |
| BATADV_THROUGHPUT_DEFAULT_VALUE % 10); |
| hard_iface->bat_v.flags |= BATADV_WARNING_DEFAULT; |
| } |
| |
| /* if none of the above cases apply, return the base_throughput */ |
| return BATADV_THROUGHPUT_DEFAULT_VALUE; |
| } |
| |
| /** |
| * batadv_v_elp_throughput_metric_update() - worker updating the throughput |
| * metric of a single hop neighbour |
| * @work: the work queue item |
| */ |
| void batadv_v_elp_throughput_metric_update(struct work_struct *work) |
| { |
| struct batadv_hardif_neigh_node_bat_v *neigh_bat_v; |
| struct batadv_hardif_neigh_node *neigh; |
| |
| neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v, |
| metric_work); |
| neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node, |
| bat_v); |
| |
| ewma_throughput_add(&neigh->bat_v.throughput, |
| batadv_v_elp_get_throughput(neigh)); |
| |
| /* decrement refcounter to balance increment performed before scheduling |
| * this task |
| */ |
| batadv_hardif_neigh_put(neigh); |
| } |
| |
| /** |
| * batadv_v_elp_wifi_neigh_probe() - send link probing packets to a neighbour |
| * @neigh: the neighbour to probe |
| * |
| * Sends a predefined number of unicast wifi packets to a given neighbour in |
| * order to trigger the throughput estimation on this link by the RC algorithm. |
| * Packets are sent only if there there is not enough payload unicast traffic |
| * towards this neighbour.. |
| * |
| * Return: True on success and false in case of error during skb preparation. |
| */ |
| static bool |
| batadv_v_elp_wifi_neigh_probe(struct batadv_hardif_neigh_node *neigh) |
| { |
| struct batadv_hard_iface *hard_iface = neigh->if_incoming; |
| struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface); |
| unsigned long last_tx_diff; |
| struct sk_buff *skb; |
| int probe_len, i; |
| int elp_skb_len; |
| |
| /* this probing routine is for Wifi neighbours only */ |
| if (!batadv_is_wifi_hardif(hard_iface)) |
| return true; |
| |
| /* probe the neighbor only if no unicast packets have been sent |
| * to it in the last 100 milliseconds: this is the rate control |
| * algorithm sampling interval (minstrel). In this way, if not |
| * enough traffic has been sent to the neighbor, batman-adv can |
| * generate 2 probe packets and push the RC algorithm to perform |
| * the sampling |
| */ |
| last_tx_diff = jiffies_to_msecs(jiffies - neigh->bat_v.last_unicast_tx); |
| if (last_tx_diff <= BATADV_ELP_PROBE_MAX_TX_DIFF) |
| return true; |
| |
| probe_len = max_t(int, sizeof(struct batadv_elp_packet), |
| BATADV_ELP_MIN_PROBE_SIZE); |
| |
| for (i = 0; i < BATADV_ELP_PROBES_PER_NODE; i++) { |
| elp_skb_len = hard_iface->bat_v.elp_skb->len; |
| skb = skb_copy_expand(hard_iface->bat_v.elp_skb, 0, |
| probe_len - elp_skb_len, |
| GFP_ATOMIC); |
| if (!skb) |
| return false; |
| |
| /* Tell the skb to get as big as the allocated space (we want |
| * the packet to be exactly of that size to make the link |
| * throughput estimation effective. |
| */ |
| skb_put_zero(skb, probe_len - hard_iface->bat_v.elp_skb->len); |
| |
| batadv_dbg(BATADV_DBG_BATMAN, bat_priv, |
| "Sending unicast (probe) ELP packet on interface %s to %pM\n", |
| hard_iface->net_dev->name, neigh->addr); |
| |
| batadv_send_skb_packet(skb, hard_iface, neigh->addr); |
| } |
| |
| return true; |
| } |
| |
| /** |
| * batadv_v_elp_periodic_work() - ELP periodic task per interface |
| * @work: work queue item |
| * |
| * Emits broadcast ELP message in regular intervals. |
| */ |
| static void batadv_v_elp_periodic_work(struct work_struct *work) |
| { |
| struct batadv_hardif_neigh_node *hardif_neigh; |
| struct batadv_hard_iface *hard_iface; |
| struct batadv_hard_iface_bat_v *bat_v; |
| struct batadv_elp_packet *elp_packet; |
| struct batadv_priv *bat_priv; |
| struct sk_buff *skb; |
| u32 elp_interval; |
| bool ret; |
| |
| bat_v = container_of(work, struct batadv_hard_iface_bat_v, elp_wq.work); |
| hard_iface = container_of(bat_v, struct batadv_hard_iface, bat_v); |
| bat_priv = netdev_priv(hard_iface->soft_iface); |
| |
| if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) |
| goto out; |
| |
| /* we are in the process of shutting this interface down */ |
| if (hard_iface->if_status == BATADV_IF_NOT_IN_USE || |
| hard_iface->if_status == BATADV_IF_TO_BE_REMOVED) |
| goto out; |
| |
| /* the interface was enabled but may not be ready yet */ |
| if (hard_iface->if_status != BATADV_IF_ACTIVE) |
| goto restart_timer; |
| |
| skb = skb_copy(hard_iface->bat_v.elp_skb, GFP_ATOMIC); |
| if (!skb) |
| goto restart_timer; |
| |
| elp_packet = (struct batadv_elp_packet *)skb->data; |
| elp_packet->seqno = htonl(atomic_read(&hard_iface->bat_v.elp_seqno)); |
| elp_interval = atomic_read(&hard_iface->bat_v.elp_interval); |
| elp_packet->elp_interval = htonl(elp_interval); |
| |
| batadv_dbg(BATADV_DBG_BATMAN, bat_priv, |
| "Sending broadcast ELP packet on interface %s, seqno %u\n", |
| hard_iface->net_dev->name, |
| atomic_read(&hard_iface->bat_v.elp_seqno)); |
| |
| batadv_send_broadcast_skb(skb, hard_iface); |
| |
| atomic_inc(&hard_iface->bat_v.elp_seqno); |
| |
| /* The throughput metric is updated on each sent packet. This way, if a |
| * node is dead and no longer sends packets, batman-adv is still able to |
| * react timely to its death. |
| * |
| * The throughput metric is updated by following these steps: |
| * 1) if the hard_iface is wifi => send a number of unicast ELPs for |
| * probing/sampling to each neighbor |
| * 2) update the throughput metric value of each neighbor (note that the |
| * value retrieved in this step might be 100ms old because the |
| * probing packets at point 1) could still be in the HW queue) |
| */ |
| rcu_read_lock(); |
| hlist_for_each_entry_rcu(hardif_neigh, &hard_iface->neigh_list, list) { |
| if (!batadv_v_elp_wifi_neigh_probe(hardif_neigh)) |
| /* if something goes wrong while probing, better to stop |
| * sending packets immediately and reschedule the task |
| */ |
| break; |
| |
| if (!kref_get_unless_zero(&hardif_neigh->refcount)) |
| continue; |
| |
| /* Reading the estimated throughput from cfg80211 is a task that |
| * may sleep and that is not allowed in an rcu protected |
| * context. Therefore schedule a task for that. |
| */ |
| ret = queue_work(batadv_event_workqueue, |
| &hardif_neigh->bat_v.metric_work); |
| |
| if (!ret) |
| batadv_hardif_neigh_put(hardif_neigh); |
| } |
| rcu_read_unlock(); |
| |
| restart_timer: |
| batadv_v_elp_start_timer(hard_iface); |
| out: |
| return; |
| } |
| |
| /** |
| * batadv_v_elp_iface_enable() - setup the ELP interface private resources |
| * @hard_iface: interface for which the data has to be prepared |
| * |
| * Return: 0 on success or a -ENOMEM in case of failure. |
| */ |
| int batadv_v_elp_iface_enable(struct batadv_hard_iface *hard_iface) |
| { |
| static const size_t tvlv_padding = sizeof(__be32); |
| struct batadv_elp_packet *elp_packet; |
| unsigned char *elp_buff; |
| u32 random_seqno; |
| size_t size; |
| int res = -ENOMEM; |
| |
| size = ETH_HLEN + NET_IP_ALIGN + BATADV_ELP_HLEN + tvlv_padding; |
| hard_iface->bat_v.elp_skb = dev_alloc_skb(size); |
| if (!hard_iface->bat_v.elp_skb) |
| goto out; |
| |
| skb_reserve(hard_iface->bat_v.elp_skb, ETH_HLEN + NET_IP_ALIGN); |
| elp_buff = skb_put_zero(hard_iface->bat_v.elp_skb, |
| BATADV_ELP_HLEN + tvlv_padding); |
| elp_packet = (struct batadv_elp_packet *)elp_buff; |
| |
| elp_packet->packet_type = BATADV_ELP; |
| elp_packet->version = BATADV_COMPAT_VERSION; |
| |
| /* randomize initial seqno to avoid collision */ |
| get_random_bytes(&random_seqno, sizeof(random_seqno)); |
| atomic_set(&hard_iface->bat_v.elp_seqno, random_seqno); |
| |
| /* assume full-duplex by default */ |
| hard_iface->bat_v.flags |= BATADV_FULL_DUPLEX; |
| |
| /* warn the user (again) if there is no throughput data is available */ |
| hard_iface->bat_v.flags &= ~BATADV_WARNING_DEFAULT; |
| |
| if (batadv_is_wifi_hardif(hard_iface)) |
| hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX; |
| |
| INIT_DELAYED_WORK(&hard_iface->bat_v.elp_wq, |
| batadv_v_elp_periodic_work); |
| batadv_v_elp_start_timer(hard_iface); |
| res = 0; |
| |
| out: |
| return res; |
| } |
| |
| /** |
| * batadv_v_elp_iface_disable() - release ELP interface private resources |
| * @hard_iface: interface for which the resources have to be released |
| */ |
| void batadv_v_elp_iface_disable(struct batadv_hard_iface *hard_iface) |
| { |
| cancel_delayed_work_sync(&hard_iface->bat_v.elp_wq); |
| |
| dev_kfree_skb(hard_iface->bat_v.elp_skb); |
| hard_iface->bat_v.elp_skb = NULL; |
| } |
| |
| /** |
| * batadv_v_elp_iface_activate() - update the ELP buffer belonging to the given |
| * hard-interface |
| * @primary_iface: the new primary interface |
| * @hard_iface: interface holding the to-be-updated buffer |
| */ |
| void batadv_v_elp_iface_activate(struct batadv_hard_iface *primary_iface, |
| struct batadv_hard_iface *hard_iface) |
| { |
| struct batadv_elp_packet *elp_packet; |
| struct sk_buff *skb; |
| |
| if (!hard_iface->bat_v.elp_skb) |
| return; |
| |
| skb = hard_iface->bat_v.elp_skb; |
| elp_packet = (struct batadv_elp_packet *)skb->data; |
| ether_addr_copy(elp_packet->orig, |
| primary_iface->net_dev->dev_addr); |
| } |
| |
| /** |
| * batadv_v_elp_primary_iface_set() - change internal data to reflect the new |
| * primary interface |
| * @primary_iface: the new primary interface |
| */ |
| void batadv_v_elp_primary_iface_set(struct batadv_hard_iface *primary_iface) |
| { |
| struct batadv_hard_iface *hard_iface; |
| |
| /* update orig field of every elp iface belonging to this mesh */ |
| rcu_read_lock(); |
| list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) { |
| if (primary_iface->soft_iface != hard_iface->soft_iface) |
| continue; |
| |
| batadv_v_elp_iface_activate(primary_iface, hard_iface); |
| } |
| rcu_read_unlock(); |
| } |
| |
| /** |
| * batadv_v_elp_neigh_update() - update an ELP neighbour node |
| * @bat_priv: the bat priv with all the soft interface information |
| * @neigh_addr: the neighbour interface address |
| * @if_incoming: the interface the packet was received through |
| * @elp_packet: the received ELP packet |
| * |
| * Updates the ELP neighbour node state with the data received within the new |
| * ELP packet. |
| */ |
| static void batadv_v_elp_neigh_update(struct batadv_priv *bat_priv, |
| u8 *neigh_addr, |
| struct batadv_hard_iface *if_incoming, |
| struct batadv_elp_packet *elp_packet) |
| |
| { |
| struct batadv_neigh_node *neigh; |
| struct batadv_orig_node *orig_neigh; |
| struct batadv_hardif_neigh_node *hardif_neigh; |
| s32 seqno_diff; |
| s32 elp_latest_seqno; |
| |
| orig_neigh = batadv_v_ogm_orig_get(bat_priv, elp_packet->orig); |
| if (!orig_neigh) |
| return; |
| |
| neigh = batadv_neigh_node_get_or_create(orig_neigh, |
| if_incoming, neigh_addr); |
| if (!neigh) |
| goto orig_free; |
| |
| hardif_neigh = batadv_hardif_neigh_get(if_incoming, neigh_addr); |
| if (!hardif_neigh) |
| goto neigh_free; |
| |
| elp_latest_seqno = hardif_neigh->bat_v.elp_latest_seqno; |
| seqno_diff = ntohl(elp_packet->seqno) - elp_latest_seqno; |
| |
| /* known or older sequence numbers are ignored. However always adopt |
| * if the router seems to have been restarted. |
| */ |
| if (seqno_diff < 1 && seqno_diff > -BATADV_ELP_MAX_AGE) |
| goto hardif_free; |
| |
| neigh->last_seen = jiffies; |
| hardif_neigh->last_seen = jiffies; |
| hardif_neigh->bat_v.elp_latest_seqno = ntohl(elp_packet->seqno); |
| hardif_neigh->bat_v.elp_interval = ntohl(elp_packet->elp_interval); |
| |
| hardif_free: |
| if (hardif_neigh) |
| batadv_hardif_neigh_put(hardif_neigh); |
| neigh_free: |
| if (neigh) |
| batadv_neigh_node_put(neigh); |
| orig_free: |
| if (orig_neigh) |
| batadv_orig_node_put(orig_neigh); |
| } |
| |
| /** |
| * batadv_v_elp_packet_recv() - main ELP packet handler |
| * @skb: the received packet |
| * @if_incoming: the interface this packet was received through |
| * |
| * Return: NET_RX_SUCCESS and consumes the skb if the packet was peoperly |
| * processed or NET_RX_DROP in case of failure. |
| */ |
| int batadv_v_elp_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_elp_packet *elp_packet; |
| struct batadv_hard_iface *primary_if; |
| struct ethhdr *ethhdr = (struct ethhdr *)skb_mac_header(skb); |
| bool res; |
| int ret = NET_RX_DROP; |
| |
| res = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN); |
| if (!res) |
| goto free_skb; |
| |
| if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) |
| goto free_skb; |
| |
| /* did we receive a B.A.T.M.A.N. V ELP packet on an interface |
| * that does not have B.A.T.M.A.N. V ELP enabled ? |
| */ |
| if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0) |
| goto free_skb; |
| |
| elp_packet = (struct batadv_elp_packet *)skb->data; |
| |
| batadv_dbg(BATADV_DBG_BATMAN, bat_priv, |
| "Received ELP packet from %pM seqno %u ORIG: %pM\n", |
| ethhdr->h_source, ntohl(elp_packet->seqno), |
| elp_packet->orig); |
| |
| primary_if = batadv_primary_if_get_selected(bat_priv); |
| if (!primary_if) |
| goto free_skb; |
| |
| batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming, |
| elp_packet); |
| |
| ret = NET_RX_SUCCESS; |
| batadv_hardif_put(primary_if); |
| |
| free_skb: |
| if (ret == NET_RX_SUCCESS) |
| consume_skb(skb); |
| else |
| kfree_skb(skb); |
| |
| return ret; |
| } |