cregit-Linux how code gets into the kernel

Release 4.8 net/batman-adv/bat_v_elp.c

Directory: net/batman-adv
/* Copyright (C) 2011-2016 B.A.T.M.A.N. contributors:
 * Linus Lüssing, Marek Lindner
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <>.

#include "bat_v_elp.h"
#include "main.h"

#include <linux/atomic.h>
#include <linux/byteorder/generic.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/fs.h>
#include <linux/if_ether.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/netdevice.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 "bat_algo.h"
#include "bat_v_ogm.h"
#include "hard-interface.h"
#include "log.h"
#include "originator.h"
#include "packet.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)); }


linus lussinglinus lussing57100.00%1100.00%

/** * 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 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_netdev(hard_iface->net_dev)) { if (hard_iface->net_dev->ieee80211_ptr) { ret = cfg80211_get_station(hard_iface->net_dev, neigh->addr, &sinfo); 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) return sinfo.expected_throughput / 100; } /* unsupported WiFi driver version */ 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; }


antonio quartulliantonio quartulli267100.00%1100.00%

/** * 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); }


antonio quartulliantonio quartulli65100.00%1100.00%

/** * 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_netdev(hard_iface->net_dev)) 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(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; }


antonio quartulliantonio quartulli202100.00%1100.00%

/** * 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; bat_v = container_of(work, struct batadv_hard_iface_bat_v,; 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. */ queue_work(batadv_event_workqueue, &hardif_neigh->bat_v.metric_work); } rcu_read_unlock(); restart_timer: batadv_v_elp_start_timer(hard_iface); out: return; }


linus lussinglinus lussing24480.79%125.00%
antonio quartulliantonio quartulli5819.21%375.00%

/** * 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) { 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; 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(hard_iface->bat_v.elp_skb, BATADV_ELP_HLEN); elp_packet = (struct batadv_elp_packet *)elp_buff; memset(elp_packet, 0, BATADV_ELP_HLEN); 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_netdev(hard_iface->net_dev)) 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; }


linus lussinglinus lussing16982.04%266.67%
antonio quartulliantonio quartulli3717.96%133.33%

/** * 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; }


linus lussinglinus lussing37100.00%1100.00%

/** * 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); }


linus lussinglinus lussing6292.54%150.00%
marek lindnermarek lindner57.46%150.00%

/** * 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(); }


marek lindnermarek lindner4692.00%150.00%
linus lussinglinus lussing48.00%150.00%

/** * 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); }


linus lussinglinus lussing20399.51%150.00%
marek lindnermarek lindner10.49%150.00%

/** * 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 ret; ret = batadv_check_management_packet(skb, if_incoming, BATADV_ELP_HLEN); if (!ret) return NET_RX_DROP; if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) return NET_RX_DROP; /* 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) return NET_RX_DROP; 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 out; batadv_v_elp_neigh_update(bat_priv, ethhdr->h_source, if_incoming, elp_packet); out: if (primary_if) batadv_hardif_put(primary_if); consume_skb(skb); return NET_RX_SUCCESS; }


linus lussinglinus lussing18899.47%150.00%
antonio quartulliantonio quartulli10.53%150.00%

Overall Contributors

linus lussinglinus lussing104759.79%327.27%
antonio quartulliantonio quartulli64736.95%545.45%
marek lindnermarek lindner543.08%218.18%
sven eckelmannsven eckelmann30.17%19.09%
Directory: net/batman-adv
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.