diff options
Diffstat (limited to 'net/batman-adv/bat_v_elp.c')
| -rw-r--r-- | net/batman-adv/bat_v_elp.c | 554 |
1 files changed, 554 insertions, 0 deletions
diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c new file mode 100644 index 000000000..83586f1dd --- /dev/null +++ b/net/batman-adv/bat_v_elp.c @@ -0,0 +1,554 @@ +// 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/prandom.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_max(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 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(); + if (ret == 0) { + /* 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 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 messages 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 properly + * 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; + bool res; + int ret = NET_RX_DROP; + + res = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN); + if (!res) + goto free_skb; + + ethhdr = eth_hdr(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; +} |