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![Sven Eckelmann](/assets/img/avatar_default.png)
All files got a SPDX-License-Identifier with commit 7db7d9f369
("batman-adv: Add SPDX license identifier above copyright header"). All the
required information about the license conditions can be found in
LICENSES/.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
1493 lines
42 KiB
C
1493 lines
42 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (C) 2012-2019 B.A.T.M.A.N. contributors:
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*
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* Edo Monticelli, Antonio Quartulli
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*/
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#include "tp_meter.h"
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#include "main.h"
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#include <linux/atomic.h>
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#include <linux/build_bug.h>
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#include <linux/byteorder/generic.h>
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#include <linux/cache.h>
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#include <linux/compiler.h>
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#include <linux/err.h>
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#include <linux/etherdevice.h>
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#include <linux/gfp.h>
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#include <linux/if_ether.h>
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#include <linux/init.h>
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#include <linux/jiffies.h>
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#include <linux/kernel.h>
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#include <linux/kref.h>
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#include <linux/kthread.h>
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#include <linux/list.h>
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#include <linux/netdevice.h>
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#include <linux/param.h>
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#include <linux/printk.h>
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#include <linux/random.h>
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#include <linux/rculist.h>
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#include <linux/rcupdate.h>
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#include <linux/sched.h>
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#include <linux/skbuff.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/stddef.h>
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#include <linux/string.h>
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#include <linux/timer.h>
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#include <linux/wait.h>
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#include <linux/workqueue.h>
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#include <uapi/linux/batadv_packet.h>
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#include <uapi/linux/batman_adv.h>
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#include "hard-interface.h"
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#include "log.h"
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#include "netlink.h"
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#include "originator.h"
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#include "send.h"
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/**
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* BATADV_TP_DEF_TEST_LENGTH - Default test length if not specified by the user
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* in milliseconds
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*/
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#define BATADV_TP_DEF_TEST_LENGTH 10000
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/**
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* BATADV_TP_AWND - Advertised window by the receiver (in bytes)
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*/
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#define BATADV_TP_AWND 0x20000000
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/**
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* BATADV_TP_RECV_TIMEOUT - Receiver activity timeout. If the receiver does not
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* get anything for such amount of milliseconds, the connection is killed
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*/
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#define BATADV_TP_RECV_TIMEOUT 1000
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/**
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* BATADV_TP_MAX_RTO - Maximum sender timeout. If the sender RTO gets beyond
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* such amound of milliseconds, the receiver is considered unreachable and the
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* connection is killed
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*/
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#define BATADV_TP_MAX_RTO 30000
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/**
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* BATADV_TP_FIRST_SEQ - First seqno of each session. The number is rather high
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* in order to immediately trigger a wrap around (test purposes)
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*/
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#define BATADV_TP_FIRST_SEQ ((u32)-1 - 2000)
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/**
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* BATADV_TP_PLEN - length of the payload (data after the batadv_unicast header)
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* to simulate
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*/
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#define BATADV_TP_PLEN (BATADV_TP_PACKET_LEN - ETH_HLEN - \
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sizeof(struct batadv_unicast_packet))
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static u8 batadv_tp_prerandom[4096] __read_mostly;
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/**
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* batadv_tp_session_cookie() - generate session cookie based on session ids
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* @session: TP session identifier
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* @icmp_uid: icmp pseudo uid of the tp session
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*
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* Return: 32 bit tp_meter session cookie
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*/
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static u32 batadv_tp_session_cookie(const u8 session[2], u8 icmp_uid)
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{
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u32 cookie;
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cookie = icmp_uid << 16;
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cookie |= session[0] << 8;
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cookie |= session[1];
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return cookie;
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}
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/**
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* batadv_tp_cwnd() - compute the new cwnd size
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* @base: base cwnd size value
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* @increment: the value to add to base to get the new size
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* @min: minumim cwnd value (usually MSS)
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*
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* Return the new cwnd size and ensures it does not exceed the Advertised
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* Receiver Window size. It is wrap around safe.
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* For details refer to Section 3.1 of RFC5681
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*
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* Return: new congestion window size in bytes
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*/
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static u32 batadv_tp_cwnd(u32 base, u32 increment, u32 min)
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{
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u32 new_size = base + increment;
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/* check for wrap-around */
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if (new_size < base)
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new_size = (u32)ULONG_MAX;
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new_size = min_t(u32, new_size, BATADV_TP_AWND);
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return max_t(u32, new_size, min);
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}
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/**
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* batadv_tp_updated_cwnd() - update the Congestion Windows
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* @tp_vars: the private data of the current TP meter session
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* @mss: maximum segment size of transmission
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*
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* 1) if the session is in Slow Start, the CWND has to be increased by 1
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* MSS every unique received ACK
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* 2) if the session is in Congestion Avoidance, the CWND has to be
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* increased by MSS * MSS / CWND for every unique received ACK
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*/
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static void batadv_tp_update_cwnd(struct batadv_tp_vars *tp_vars, u32 mss)
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{
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spin_lock_bh(&tp_vars->cwnd_lock);
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/* slow start... */
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if (tp_vars->cwnd <= tp_vars->ss_threshold) {
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tp_vars->dec_cwnd = 0;
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tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, mss, mss);
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spin_unlock_bh(&tp_vars->cwnd_lock);
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return;
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}
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/* increment CWND at least of 1 (section 3.1 of RFC5681) */
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tp_vars->dec_cwnd += max_t(u32, 1U << 3,
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((mss * mss) << 6) / (tp_vars->cwnd << 3));
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if (tp_vars->dec_cwnd < (mss << 3)) {
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spin_unlock_bh(&tp_vars->cwnd_lock);
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return;
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}
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tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, mss, mss);
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tp_vars->dec_cwnd = 0;
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spin_unlock_bh(&tp_vars->cwnd_lock);
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}
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/**
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* batadv_tp_update_rto() - calculate new retransmission timeout
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* @tp_vars: the private data of the current TP meter session
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* @new_rtt: new roundtrip time in msec
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*/
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static void batadv_tp_update_rto(struct batadv_tp_vars *tp_vars,
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u32 new_rtt)
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{
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long m = new_rtt;
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/* RTT update
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* Details in Section 2.2 and 2.3 of RFC6298
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*
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* It's tricky to understand. Don't lose hair please.
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* Inspired by tcp_rtt_estimator() tcp_input.c
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*/
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if (tp_vars->srtt != 0) {
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m -= (tp_vars->srtt >> 3); /* m is now error in rtt est */
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tp_vars->srtt += m; /* rtt = 7/8 srtt + 1/8 new */
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if (m < 0)
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m = -m;
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m -= (tp_vars->rttvar >> 2);
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tp_vars->rttvar += m; /* mdev ~= 3/4 rttvar + 1/4 new */
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} else {
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/* first measure getting in */
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tp_vars->srtt = m << 3; /* take the measured time to be srtt */
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tp_vars->rttvar = m << 1; /* new_rtt / 2 */
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}
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/* rto = srtt + 4 * rttvar.
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* rttvar is scaled by 4, therefore doesn't need to be multiplied
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*/
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tp_vars->rto = (tp_vars->srtt >> 3) + tp_vars->rttvar;
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}
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/**
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* batadv_tp_batctl_notify() - send client status result to client
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* @reason: reason for tp meter session stop
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* @dst: destination of tp_meter session
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* @bat_priv: the bat priv with all the soft interface information
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* @start_time: start of transmission in jiffies
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* @total_sent: bytes acked to the receiver
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* @cookie: cookie of tp_meter session
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*/
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static void batadv_tp_batctl_notify(enum batadv_tp_meter_reason reason,
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const u8 *dst, struct batadv_priv *bat_priv,
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unsigned long start_time, u64 total_sent,
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u32 cookie)
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{
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u32 test_time;
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u8 result;
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u32 total_bytes;
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if (!batadv_tp_is_error(reason)) {
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result = BATADV_TP_REASON_COMPLETE;
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test_time = jiffies_to_msecs(jiffies - start_time);
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total_bytes = total_sent;
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} else {
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result = reason;
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test_time = 0;
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total_bytes = 0;
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}
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batadv_netlink_tpmeter_notify(bat_priv, dst, result, test_time,
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total_bytes, cookie);
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}
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/**
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* batadv_tp_batctl_error_notify() - send client error result to client
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* @reason: reason for tp meter session stop
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* @dst: destination of tp_meter session
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* @bat_priv: the bat priv with all the soft interface information
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* @cookie: cookie of tp_meter session
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*/
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static void batadv_tp_batctl_error_notify(enum batadv_tp_meter_reason reason,
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const u8 *dst,
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struct batadv_priv *bat_priv,
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u32 cookie)
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{
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batadv_tp_batctl_notify(reason, dst, bat_priv, 0, 0, cookie);
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}
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/**
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* batadv_tp_list_find() - find a tp_vars object in the global list
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* @bat_priv: the bat priv with all the soft interface information
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* @dst: the other endpoint MAC address to look for
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*
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* Look for a tp_vars object matching dst as end_point and return it after
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* having incremented the refcounter. Return NULL is not found
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*
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* Return: matching tp_vars or NULL when no tp_vars with @dst was found
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*/
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static struct batadv_tp_vars *batadv_tp_list_find(struct batadv_priv *bat_priv,
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const u8 *dst)
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{
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struct batadv_tp_vars *pos, *tp_vars = NULL;
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rcu_read_lock();
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hlist_for_each_entry_rcu(pos, &bat_priv->tp_list, list) {
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if (!batadv_compare_eth(pos->other_end, dst))
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continue;
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/* most of the time this function is invoked during the normal
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* process..it makes sens to pay more when the session is
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* finished and to speed the process up during the measurement
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*/
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if (unlikely(!kref_get_unless_zero(&pos->refcount)))
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continue;
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tp_vars = pos;
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break;
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}
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rcu_read_unlock();
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return tp_vars;
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}
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/**
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* batadv_tp_list_find_session() - find tp_vars session object in the global
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* list
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* @bat_priv: the bat priv with all the soft interface information
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* @dst: the other endpoint MAC address to look for
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* @session: session identifier
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*
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* Look for a tp_vars object matching dst as end_point, session as tp meter
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* session and return it after having incremented the refcounter. Return NULL
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* is not found
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*
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* Return: matching tp_vars or NULL when no tp_vars was found
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*/
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static struct batadv_tp_vars *
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batadv_tp_list_find_session(struct batadv_priv *bat_priv, const u8 *dst,
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const u8 *session)
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{
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struct batadv_tp_vars *pos, *tp_vars = NULL;
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rcu_read_lock();
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hlist_for_each_entry_rcu(pos, &bat_priv->tp_list, list) {
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if (!batadv_compare_eth(pos->other_end, dst))
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continue;
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if (memcmp(pos->session, session, sizeof(pos->session)) != 0)
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continue;
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/* most of the time this function is invoked during the normal
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* process..it makes sense to pay more when the session is
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* finished and to speed the process up during the measurement
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*/
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if (unlikely(!kref_get_unless_zero(&pos->refcount)))
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continue;
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tp_vars = pos;
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break;
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}
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rcu_read_unlock();
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return tp_vars;
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}
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/**
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* batadv_tp_vars_release() - release batadv_tp_vars from lists and queue for
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* free after rcu grace period
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* @ref: kref pointer of the batadv_tp_vars
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*/
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static void batadv_tp_vars_release(struct kref *ref)
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{
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struct batadv_tp_vars *tp_vars;
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struct batadv_tp_unacked *un, *safe;
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tp_vars = container_of(ref, struct batadv_tp_vars, refcount);
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/* lock should not be needed because this object is now out of any
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* context!
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*/
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spin_lock_bh(&tp_vars->unacked_lock);
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list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) {
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list_del(&un->list);
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kfree(un);
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}
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spin_unlock_bh(&tp_vars->unacked_lock);
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kfree_rcu(tp_vars, rcu);
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}
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/**
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* batadv_tp_vars_put() - decrement the batadv_tp_vars refcounter and possibly
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* release it
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* @tp_vars: the private data of the current TP meter session to be free'd
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*/
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static void batadv_tp_vars_put(struct batadv_tp_vars *tp_vars)
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{
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kref_put(&tp_vars->refcount, batadv_tp_vars_release);
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}
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/**
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* batadv_tp_sender_cleanup() - cleanup sender data and drop and timer
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* @bat_priv: the bat priv with all the soft interface information
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* @tp_vars: the private data of the current TP meter session to cleanup
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*/
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static void batadv_tp_sender_cleanup(struct batadv_priv *bat_priv,
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struct batadv_tp_vars *tp_vars)
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{
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cancel_delayed_work(&tp_vars->finish_work);
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spin_lock_bh(&tp_vars->bat_priv->tp_list_lock);
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hlist_del_rcu(&tp_vars->list);
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spin_unlock_bh(&tp_vars->bat_priv->tp_list_lock);
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/* drop list reference */
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batadv_tp_vars_put(tp_vars);
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atomic_dec(&tp_vars->bat_priv->tp_num);
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/* kill the timer and remove its reference */
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del_timer_sync(&tp_vars->timer);
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/* the worker might have rearmed itself therefore we kill it again. Note
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* that if the worker should run again before invoking the following
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* del_timer(), it would not re-arm itself once again because the status
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* is OFF now
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*/
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del_timer(&tp_vars->timer);
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batadv_tp_vars_put(tp_vars);
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}
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/**
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* batadv_tp_sender_end() - print info about ended session and inform client
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* @bat_priv: the bat priv with all the soft interface information
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* @tp_vars: the private data of the current TP meter session
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*/
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static void batadv_tp_sender_end(struct batadv_priv *bat_priv,
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struct batadv_tp_vars *tp_vars)
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{
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u32 session_cookie;
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batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
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"Test towards %pM finished..shutting down (reason=%d)\n",
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tp_vars->other_end, tp_vars->reason);
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batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
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"Last timing stats: SRTT=%ums RTTVAR=%ums RTO=%ums\n",
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tp_vars->srtt >> 3, tp_vars->rttvar >> 2, tp_vars->rto);
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batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
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"Final values: cwnd=%u ss_threshold=%u\n",
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tp_vars->cwnd, tp_vars->ss_threshold);
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session_cookie = batadv_tp_session_cookie(tp_vars->session,
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tp_vars->icmp_uid);
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batadv_tp_batctl_notify(tp_vars->reason,
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tp_vars->other_end,
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bat_priv,
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tp_vars->start_time,
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atomic64_read(&tp_vars->tot_sent),
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session_cookie);
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}
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/**
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* batadv_tp_sender_shutdown() - let sender thread/timer stop gracefully
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* @tp_vars: the private data of the current TP meter session
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* @reason: reason for tp meter session stop
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*/
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static void batadv_tp_sender_shutdown(struct batadv_tp_vars *tp_vars,
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enum batadv_tp_meter_reason reason)
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{
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if (!atomic_dec_and_test(&tp_vars->sending))
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return;
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tp_vars->reason = reason;
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}
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/**
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* batadv_tp_sender_finish() - stop sender session after test_length was reached
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* @work: delayed work reference of the related tp_vars
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*/
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static void batadv_tp_sender_finish(struct work_struct *work)
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{
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struct delayed_work *delayed_work;
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struct batadv_tp_vars *tp_vars;
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delayed_work = to_delayed_work(work);
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tp_vars = container_of(delayed_work, struct batadv_tp_vars,
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finish_work);
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batadv_tp_sender_shutdown(tp_vars, BATADV_TP_REASON_COMPLETE);
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}
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/**
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* batadv_tp_reset_sender_timer() - reschedule the sender timer
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* @tp_vars: the private TP meter data for this session
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*
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* Reschedule the timer using tp_vars->rto as delay
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*/
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static void batadv_tp_reset_sender_timer(struct batadv_tp_vars *tp_vars)
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{
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/* most of the time this function is invoked while normal packet
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* reception...
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*/
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if (unlikely(atomic_read(&tp_vars->sending) == 0))
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/* timer ref will be dropped in batadv_tp_sender_cleanup */
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return;
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mod_timer(&tp_vars->timer, jiffies + msecs_to_jiffies(tp_vars->rto));
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}
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/**
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* batadv_tp_sender_timeout() - timer that fires in case of packet loss
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* @t: address to timer_list inside tp_vars
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*
|
|
* If fired it means that there was packet loss.
|
|
* Switch to Slow Start, set the ss_threshold to half of the current cwnd and
|
|
* reset the cwnd to 3*MSS
|
|
*/
|
|
static void batadv_tp_sender_timeout(struct timer_list *t)
|
|
{
|
|
struct batadv_tp_vars *tp_vars = from_timer(tp_vars, t, timer);
|
|
struct batadv_priv *bat_priv = tp_vars->bat_priv;
|
|
|
|
if (atomic_read(&tp_vars->sending) == 0)
|
|
return;
|
|
|
|
/* if the user waited long enough...shutdown the test */
|
|
if (unlikely(tp_vars->rto >= BATADV_TP_MAX_RTO)) {
|
|
batadv_tp_sender_shutdown(tp_vars,
|
|
BATADV_TP_REASON_DST_UNREACHABLE);
|
|
return;
|
|
}
|
|
|
|
/* RTO exponential backoff
|
|
* Details in Section 5.5 of RFC6298
|
|
*/
|
|
tp_vars->rto <<= 1;
|
|
|
|
spin_lock_bh(&tp_vars->cwnd_lock);
|
|
|
|
tp_vars->ss_threshold = tp_vars->cwnd >> 1;
|
|
if (tp_vars->ss_threshold < BATADV_TP_PLEN * 2)
|
|
tp_vars->ss_threshold = BATADV_TP_PLEN * 2;
|
|
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Meter: RTO fired during test towards %pM! cwnd=%u new ss_thr=%u, resetting last_sent to %u\n",
|
|
tp_vars->other_end, tp_vars->cwnd, tp_vars->ss_threshold,
|
|
atomic_read(&tp_vars->last_acked));
|
|
|
|
tp_vars->cwnd = BATADV_TP_PLEN * 3;
|
|
|
|
spin_unlock_bh(&tp_vars->cwnd_lock);
|
|
|
|
/* resend the non-ACKed packets.. */
|
|
tp_vars->last_sent = atomic_read(&tp_vars->last_acked);
|
|
wake_up(&tp_vars->more_bytes);
|
|
|
|
batadv_tp_reset_sender_timer(tp_vars);
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_fill_prerandom() - Fill buffer with prefetched random bytes
|
|
* @tp_vars: the private TP meter data for this session
|
|
* @buf: Buffer to fill with bytes
|
|
* @nbytes: amount of pseudorandom bytes
|
|
*/
|
|
static void batadv_tp_fill_prerandom(struct batadv_tp_vars *tp_vars,
|
|
u8 *buf, size_t nbytes)
|
|
{
|
|
u32 local_offset;
|
|
size_t bytes_inbuf;
|
|
size_t to_copy;
|
|
size_t pos = 0;
|
|
|
|
spin_lock_bh(&tp_vars->prerandom_lock);
|
|
local_offset = tp_vars->prerandom_offset;
|
|
tp_vars->prerandom_offset += nbytes;
|
|
tp_vars->prerandom_offset %= sizeof(batadv_tp_prerandom);
|
|
spin_unlock_bh(&tp_vars->prerandom_lock);
|
|
|
|
while (nbytes) {
|
|
local_offset %= sizeof(batadv_tp_prerandom);
|
|
bytes_inbuf = sizeof(batadv_tp_prerandom) - local_offset;
|
|
to_copy = min(nbytes, bytes_inbuf);
|
|
|
|
memcpy(&buf[pos], &batadv_tp_prerandom[local_offset], to_copy);
|
|
pos += to_copy;
|
|
nbytes -= to_copy;
|
|
local_offset = 0;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_send_msg() - send a single message
|
|
* @tp_vars: the private TP meter data for this session
|
|
* @src: source mac address
|
|
* @orig_node: the originator of the destination
|
|
* @seqno: sequence number of this packet
|
|
* @len: length of the entire packet
|
|
* @session: session identifier
|
|
* @uid: local ICMP "socket" index
|
|
* @timestamp: timestamp in jiffies which is replied in ack
|
|
*
|
|
* Create and send a single TP Meter message.
|
|
*
|
|
* Return: 0 on success, BATADV_TP_REASON_DST_UNREACHABLE if the destination is
|
|
* not reachable, BATADV_TP_REASON_MEMORY_ERROR if the packet couldn't be
|
|
* allocated
|
|
*/
|
|
static int batadv_tp_send_msg(struct batadv_tp_vars *tp_vars, const u8 *src,
|
|
struct batadv_orig_node *orig_node,
|
|
u32 seqno, size_t len, const u8 *session,
|
|
int uid, u32 timestamp)
|
|
{
|
|
struct batadv_icmp_tp_packet *icmp;
|
|
struct sk_buff *skb;
|
|
int r;
|
|
u8 *data;
|
|
size_t data_len;
|
|
|
|
skb = netdev_alloc_skb_ip_align(NULL, len + ETH_HLEN);
|
|
if (unlikely(!skb))
|
|
return BATADV_TP_REASON_MEMORY_ERROR;
|
|
|
|
skb_reserve(skb, ETH_HLEN);
|
|
icmp = skb_put(skb, sizeof(*icmp));
|
|
|
|
/* fill the icmp header */
|
|
ether_addr_copy(icmp->dst, orig_node->orig);
|
|
ether_addr_copy(icmp->orig, src);
|
|
icmp->version = BATADV_COMPAT_VERSION;
|
|
icmp->packet_type = BATADV_ICMP;
|
|
icmp->ttl = BATADV_TTL;
|
|
icmp->msg_type = BATADV_TP;
|
|
icmp->uid = uid;
|
|
|
|
icmp->subtype = BATADV_TP_MSG;
|
|
memcpy(icmp->session, session, sizeof(icmp->session));
|
|
icmp->seqno = htonl(seqno);
|
|
icmp->timestamp = htonl(timestamp);
|
|
|
|
data_len = len - sizeof(*icmp);
|
|
data = skb_put(skb, data_len);
|
|
batadv_tp_fill_prerandom(tp_vars, data, data_len);
|
|
|
|
r = batadv_send_skb_to_orig(skb, orig_node, NULL);
|
|
if (r == NET_XMIT_SUCCESS)
|
|
return 0;
|
|
|
|
return BATADV_TP_REASON_CANT_SEND;
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_recv_ack() - ACK receiving function
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @skb: the buffer containing the received packet
|
|
*
|
|
* Process a received TP ACK packet
|
|
*/
|
|
static void batadv_tp_recv_ack(struct batadv_priv *bat_priv,
|
|
const struct sk_buff *skb)
|
|
{
|
|
struct batadv_hard_iface *primary_if = NULL;
|
|
struct batadv_orig_node *orig_node = NULL;
|
|
const struct batadv_icmp_tp_packet *icmp;
|
|
struct batadv_tp_vars *tp_vars;
|
|
size_t packet_len, mss;
|
|
u32 rtt, recv_ack, cwnd;
|
|
unsigned char *dev_addr;
|
|
|
|
packet_len = BATADV_TP_PLEN;
|
|
mss = BATADV_TP_PLEN;
|
|
packet_len += sizeof(struct batadv_unicast_packet);
|
|
|
|
icmp = (struct batadv_icmp_tp_packet *)skb->data;
|
|
|
|
/* find the tp_vars */
|
|
tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig,
|
|
icmp->session);
|
|
if (unlikely(!tp_vars))
|
|
return;
|
|
|
|
if (unlikely(atomic_read(&tp_vars->sending) == 0))
|
|
goto out;
|
|
|
|
/* old ACK? silently drop it.. */
|
|
if (batadv_seq_before(ntohl(icmp->seqno),
|
|
(u32)atomic_read(&tp_vars->last_acked)))
|
|
goto out;
|
|
|
|
primary_if = batadv_primary_if_get_selected(bat_priv);
|
|
if (unlikely(!primary_if))
|
|
goto out;
|
|
|
|
orig_node = batadv_orig_hash_find(bat_priv, icmp->orig);
|
|
if (unlikely(!orig_node))
|
|
goto out;
|
|
|
|
/* update RTO with the new sampled RTT, if any */
|
|
rtt = jiffies_to_msecs(jiffies) - ntohl(icmp->timestamp);
|
|
if (icmp->timestamp && rtt)
|
|
batadv_tp_update_rto(tp_vars, rtt);
|
|
|
|
/* ACK for new data... reset the timer */
|
|
batadv_tp_reset_sender_timer(tp_vars);
|
|
|
|
recv_ack = ntohl(icmp->seqno);
|
|
|
|
/* check if this ACK is a duplicate */
|
|
if (atomic_read(&tp_vars->last_acked) == recv_ack) {
|
|
atomic_inc(&tp_vars->dup_acks);
|
|
if (atomic_read(&tp_vars->dup_acks) != 3)
|
|
goto out;
|
|
|
|
if (recv_ack >= tp_vars->recover)
|
|
goto out;
|
|
|
|
/* if this is the third duplicate ACK do Fast Retransmit */
|
|
batadv_tp_send_msg(tp_vars, primary_if->net_dev->dev_addr,
|
|
orig_node, recv_ack, packet_len,
|
|
icmp->session, icmp->uid,
|
|
jiffies_to_msecs(jiffies));
|
|
|
|
spin_lock_bh(&tp_vars->cwnd_lock);
|
|
|
|
/* Fast Recovery */
|
|
tp_vars->fast_recovery = true;
|
|
/* Set recover to the last outstanding seqno when Fast Recovery
|
|
* is entered. RFC6582, Section 3.2, step 1
|
|
*/
|
|
tp_vars->recover = tp_vars->last_sent;
|
|
tp_vars->ss_threshold = tp_vars->cwnd >> 1;
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Meter: Fast Recovery, (cur cwnd=%u) ss_thr=%u last_sent=%u recv_ack=%u\n",
|
|
tp_vars->cwnd, tp_vars->ss_threshold,
|
|
tp_vars->last_sent, recv_ack);
|
|
tp_vars->cwnd = batadv_tp_cwnd(tp_vars->ss_threshold, 3 * mss,
|
|
mss);
|
|
tp_vars->dec_cwnd = 0;
|
|
tp_vars->last_sent = recv_ack;
|
|
|
|
spin_unlock_bh(&tp_vars->cwnd_lock);
|
|
} else {
|
|
/* count the acked data */
|
|
atomic64_add(recv_ack - atomic_read(&tp_vars->last_acked),
|
|
&tp_vars->tot_sent);
|
|
/* reset the duplicate ACKs counter */
|
|
atomic_set(&tp_vars->dup_acks, 0);
|
|
|
|
if (tp_vars->fast_recovery) {
|
|
/* partial ACK */
|
|
if (batadv_seq_before(recv_ack, tp_vars->recover)) {
|
|
/* this is another hole in the window. React
|
|
* immediately as specified by NewReno (see
|
|
* Section 3.2 of RFC6582 for details)
|
|
*/
|
|
dev_addr = primary_if->net_dev->dev_addr;
|
|
batadv_tp_send_msg(tp_vars, dev_addr,
|
|
orig_node, recv_ack,
|
|
packet_len, icmp->session,
|
|
icmp->uid,
|
|
jiffies_to_msecs(jiffies));
|
|
tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd,
|
|
mss, mss);
|
|
} else {
|
|
tp_vars->fast_recovery = false;
|
|
/* set cwnd to the value of ss_threshold at the
|
|
* moment that Fast Recovery was entered.
|
|
* RFC6582, Section 3.2, step 3
|
|
*/
|
|
cwnd = batadv_tp_cwnd(tp_vars->ss_threshold, 0,
|
|
mss);
|
|
tp_vars->cwnd = cwnd;
|
|
}
|
|
goto move_twnd;
|
|
}
|
|
|
|
if (recv_ack - atomic_read(&tp_vars->last_acked) >= mss)
|
|
batadv_tp_update_cwnd(tp_vars, mss);
|
|
move_twnd:
|
|
/* move the Transmit Window */
|
|
atomic_set(&tp_vars->last_acked, recv_ack);
|
|
}
|
|
|
|
wake_up(&tp_vars->more_bytes);
|
|
out:
|
|
if (likely(primary_if))
|
|
batadv_hardif_put(primary_if);
|
|
if (likely(orig_node))
|
|
batadv_orig_node_put(orig_node);
|
|
if (likely(tp_vars))
|
|
batadv_tp_vars_put(tp_vars);
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_avail() - check if congestion window is not full
|
|
* @tp_vars: the private data of the current TP meter session
|
|
* @payload_len: size of the payload of a single message
|
|
*
|
|
* Return: true when congestion window is not full, false otherwise
|
|
*/
|
|
static bool batadv_tp_avail(struct batadv_tp_vars *tp_vars,
|
|
size_t payload_len)
|
|
{
|
|
u32 win_left, win_limit;
|
|
|
|
win_limit = atomic_read(&tp_vars->last_acked) + tp_vars->cwnd;
|
|
win_left = win_limit - tp_vars->last_sent;
|
|
|
|
return win_left >= payload_len;
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_wait_available() - wait until congestion window becomes free or
|
|
* timeout is reached
|
|
* @tp_vars: the private data of the current TP meter session
|
|
* @plen: size of the payload of a single message
|
|
*
|
|
* Return: 0 if the condition evaluated to false after the timeout elapsed,
|
|
* 1 if the condition evaluated to true after the timeout elapsed, the
|
|
* remaining jiffies (at least 1) if the condition evaluated to true before
|
|
* the timeout elapsed, or -ERESTARTSYS if it was interrupted by a signal.
|
|
*/
|
|
static int batadv_tp_wait_available(struct batadv_tp_vars *tp_vars, size_t plen)
|
|
{
|
|
int ret;
|
|
|
|
ret = wait_event_interruptible_timeout(tp_vars->more_bytes,
|
|
batadv_tp_avail(tp_vars, plen),
|
|
HZ / 10);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_send() - main sending thread of a tp meter session
|
|
* @arg: address of the related tp_vars
|
|
*
|
|
* Return: nothing, this function never returns
|
|
*/
|
|
static int batadv_tp_send(void *arg)
|
|
{
|
|
struct batadv_tp_vars *tp_vars = arg;
|
|
struct batadv_priv *bat_priv = tp_vars->bat_priv;
|
|
struct batadv_hard_iface *primary_if = NULL;
|
|
struct batadv_orig_node *orig_node = NULL;
|
|
size_t payload_len, packet_len;
|
|
int err = 0;
|
|
|
|
if (unlikely(tp_vars->role != BATADV_TP_SENDER)) {
|
|
err = BATADV_TP_REASON_DST_UNREACHABLE;
|
|
tp_vars->reason = err;
|
|
goto out;
|
|
}
|
|
|
|
orig_node = batadv_orig_hash_find(bat_priv, tp_vars->other_end);
|
|
if (unlikely(!orig_node)) {
|
|
err = BATADV_TP_REASON_DST_UNREACHABLE;
|
|
tp_vars->reason = err;
|
|
goto out;
|
|
}
|
|
|
|
primary_if = batadv_primary_if_get_selected(bat_priv);
|
|
if (unlikely(!primary_if)) {
|
|
err = BATADV_TP_REASON_DST_UNREACHABLE;
|
|
tp_vars->reason = err;
|
|
goto out;
|
|
}
|
|
|
|
/* assume that all the hard_interfaces have a correctly
|
|
* configured MTU, so use the soft_iface MTU as MSS.
|
|
* This might not be true and in that case the fragmentation
|
|
* should be used.
|
|
* Now, try to send the packet as it is
|
|
*/
|
|
payload_len = BATADV_TP_PLEN;
|
|
BUILD_BUG_ON(sizeof(struct batadv_icmp_tp_packet) > BATADV_TP_PLEN);
|
|
|
|
batadv_tp_reset_sender_timer(tp_vars);
|
|
|
|
/* queue the worker in charge of terminating the test */
|
|
queue_delayed_work(batadv_event_workqueue, &tp_vars->finish_work,
|
|
msecs_to_jiffies(tp_vars->test_length));
|
|
|
|
while (atomic_read(&tp_vars->sending) != 0) {
|
|
if (unlikely(!batadv_tp_avail(tp_vars, payload_len))) {
|
|
batadv_tp_wait_available(tp_vars, payload_len);
|
|
continue;
|
|
}
|
|
|
|
/* to emulate normal unicast traffic, add to the payload len
|
|
* the size of the unicast header
|
|
*/
|
|
packet_len = payload_len + sizeof(struct batadv_unicast_packet);
|
|
|
|
err = batadv_tp_send_msg(tp_vars, primary_if->net_dev->dev_addr,
|
|
orig_node, tp_vars->last_sent,
|
|
packet_len,
|
|
tp_vars->session, tp_vars->icmp_uid,
|
|
jiffies_to_msecs(jiffies));
|
|
|
|
/* something went wrong during the preparation/transmission */
|
|
if (unlikely(err && err != BATADV_TP_REASON_CANT_SEND)) {
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Meter: %s() cannot send packets (%d)\n",
|
|
__func__, err);
|
|
/* ensure nobody else tries to stop the thread now */
|
|
if (atomic_dec_and_test(&tp_vars->sending))
|
|
tp_vars->reason = err;
|
|
break;
|
|
}
|
|
|
|
/* right-shift the TWND */
|
|
if (!err)
|
|
tp_vars->last_sent += payload_len;
|
|
|
|
cond_resched();
|
|
}
|
|
|
|
out:
|
|
if (likely(primary_if))
|
|
batadv_hardif_put(primary_if);
|
|
if (likely(orig_node))
|
|
batadv_orig_node_put(orig_node);
|
|
|
|
batadv_tp_sender_end(bat_priv, tp_vars);
|
|
batadv_tp_sender_cleanup(bat_priv, tp_vars);
|
|
|
|
batadv_tp_vars_put(tp_vars);
|
|
|
|
do_exit(0);
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_start_kthread() - start new thread which manages the tp meter
|
|
* sender
|
|
* @tp_vars: the private data of the current TP meter session
|
|
*/
|
|
static void batadv_tp_start_kthread(struct batadv_tp_vars *tp_vars)
|
|
{
|
|
struct task_struct *kthread;
|
|
struct batadv_priv *bat_priv = tp_vars->bat_priv;
|
|
u32 session_cookie;
|
|
|
|
kref_get(&tp_vars->refcount);
|
|
kthread = kthread_create(batadv_tp_send, tp_vars, "kbatadv_tp_meter");
|
|
if (IS_ERR(kthread)) {
|
|
session_cookie = batadv_tp_session_cookie(tp_vars->session,
|
|
tp_vars->icmp_uid);
|
|
pr_err("batadv: cannot create tp meter kthread\n");
|
|
batadv_tp_batctl_error_notify(BATADV_TP_REASON_MEMORY_ERROR,
|
|
tp_vars->other_end,
|
|
bat_priv, session_cookie);
|
|
|
|
/* drop reserved reference for kthread */
|
|
batadv_tp_vars_put(tp_vars);
|
|
|
|
/* cleanup of failed tp meter variables */
|
|
batadv_tp_sender_cleanup(bat_priv, tp_vars);
|
|
return;
|
|
}
|
|
|
|
wake_up_process(kthread);
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_start() - start a new tp meter session
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @dst: the receiver MAC address
|
|
* @test_length: test length in milliseconds
|
|
* @cookie: session cookie
|
|
*/
|
|
void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst,
|
|
u32 test_length, u32 *cookie)
|
|
{
|
|
struct batadv_tp_vars *tp_vars;
|
|
u8 session_id[2];
|
|
u8 icmp_uid;
|
|
u32 session_cookie;
|
|
|
|
get_random_bytes(session_id, sizeof(session_id));
|
|
get_random_bytes(&icmp_uid, 1);
|
|
session_cookie = batadv_tp_session_cookie(session_id, icmp_uid);
|
|
*cookie = session_cookie;
|
|
|
|
/* look for an already existing test towards this node */
|
|
spin_lock_bh(&bat_priv->tp_list_lock);
|
|
tp_vars = batadv_tp_list_find(bat_priv, dst);
|
|
if (tp_vars) {
|
|
spin_unlock_bh(&bat_priv->tp_list_lock);
|
|
batadv_tp_vars_put(tp_vars);
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Meter: test to or from the same node already ongoing, aborting\n");
|
|
batadv_tp_batctl_error_notify(BATADV_TP_REASON_ALREADY_ONGOING,
|
|
dst, bat_priv, session_cookie);
|
|
return;
|
|
}
|
|
|
|
if (!atomic_add_unless(&bat_priv->tp_num, 1, BATADV_TP_MAX_NUM)) {
|
|
spin_unlock_bh(&bat_priv->tp_list_lock);
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Meter: too many ongoing sessions, aborting (SEND)\n");
|
|
batadv_tp_batctl_error_notify(BATADV_TP_REASON_TOO_MANY, dst,
|
|
bat_priv, session_cookie);
|
|
return;
|
|
}
|
|
|
|
tp_vars = kmalloc(sizeof(*tp_vars), GFP_ATOMIC);
|
|
if (!tp_vars) {
|
|
spin_unlock_bh(&bat_priv->tp_list_lock);
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Meter: %s cannot allocate list elements\n",
|
|
__func__);
|
|
batadv_tp_batctl_error_notify(BATADV_TP_REASON_MEMORY_ERROR,
|
|
dst, bat_priv, session_cookie);
|
|
return;
|
|
}
|
|
|
|
/* initialize tp_vars */
|
|
ether_addr_copy(tp_vars->other_end, dst);
|
|
kref_init(&tp_vars->refcount);
|
|
tp_vars->role = BATADV_TP_SENDER;
|
|
atomic_set(&tp_vars->sending, 1);
|
|
memcpy(tp_vars->session, session_id, sizeof(session_id));
|
|
tp_vars->icmp_uid = icmp_uid;
|
|
|
|
tp_vars->last_sent = BATADV_TP_FIRST_SEQ;
|
|
atomic_set(&tp_vars->last_acked, BATADV_TP_FIRST_SEQ);
|
|
tp_vars->fast_recovery = false;
|
|
tp_vars->recover = BATADV_TP_FIRST_SEQ;
|
|
|
|
/* initialise the CWND to 3*MSS (Section 3.1 in RFC5681).
|
|
* For batman-adv the MSS is the size of the payload received by the
|
|
* soft_interface, hence its MTU
|
|
*/
|
|
tp_vars->cwnd = BATADV_TP_PLEN * 3;
|
|
/* at the beginning initialise the SS threshold to the biggest possible
|
|
* window size, hence the AWND size
|
|
*/
|
|
tp_vars->ss_threshold = BATADV_TP_AWND;
|
|
|
|
/* RTO initial value is 3 seconds.
|
|
* Details in Section 2.1 of RFC6298
|
|
*/
|
|
tp_vars->rto = 1000;
|
|
tp_vars->srtt = 0;
|
|
tp_vars->rttvar = 0;
|
|
|
|
atomic64_set(&tp_vars->tot_sent, 0);
|
|
|
|
kref_get(&tp_vars->refcount);
|
|
timer_setup(&tp_vars->timer, batadv_tp_sender_timeout, 0);
|
|
|
|
tp_vars->bat_priv = bat_priv;
|
|
tp_vars->start_time = jiffies;
|
|
|
|
init_waitqueue_head(&tp_vars->more_bytes);
|
|
|
|
spin_lock_init(&tp_vars->unacked_lock);
|
|
INIT_LIST_HEAD(&tp_vars->unacked_list);
|
|
|
|
spin_lock_init(&tp_vars->cwnd_lock);
|
|
|
|
tp_vars->prerandom_offset = 0;
|
|
spin_lock_init(&tp_vars->prerandom_lock);
|
|
|
|
kref_get(&tp_vars->refcount);
|
|
hlist_add_head_rcu(&tp_vars->list, &bat_priv->tp_list);
|
|
spin_unlock_bh(&bat_priv->tp_list_lock);
|
|
|
|
tp_vars->test_length = test_length;
|
|
if (!tp_vars->test_length)
|
|
tp_vars->test_length = BATADV_TP_DEF_TEST_LENGTH;
|
|
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Meter: starting throughput meter towards %pM (length=%ums)\n",
|
|
dst, test_length);
|
|
|
|
/* init work item for finished tp tests */
|
|
INIT_DELAYED_WORK(&tp_vars->finish_work, batadv_tp_sender_finish);
|
|
|
|
/* start tp kthread. This way the write() call issued from userspace can
|
|
* happily return and avoid to block
|
|
*/
|
|
batadv_tp_start_kthread(tp_vars);
|
|
|
|
/* don't return reference to new tp_vars */
|
|
batadv_tp_vars_put(tp_vars);
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_stop() - stop currently running tp meter session
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @dst: the receiver MAC address
|
|
* @return_value: reason for tp meter session stop
|
|
*/
|
|
void batadv_tp_stop(struct batadv_priv *bat_priv, const u8 *dst,
|
|
u8 return_value)
|
|
{
|
|
struct batadv_orig_node *orig_node;
|
|
struct batadv_tp_vars *tp_vars;
|
|
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Meter: stopping test towards %pM\n", dst);
|
|
|
|
orig_node = batadv_orig_hash_find(bat_priv, dst);
|
|
if (!orig_node)
|
|
return;
|
|
|
|
tp_vars = batadv_tp_list_find(bat_priv, orig_node->orig);
|
|
if (!tp_vars) {
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Meter: trying to interrupt an already over connection\n");
|
|
goto out;
|
|
}
|
|
|
|
batadv_tp_sender_shutdown(tp_vars, return_value);
|
|
batadv_tp_vars_put(tp_vars);
|
|
out:
|
|
batadv_orig_node_put(orig_node);
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_reset_receiver_timer() - reset the receiver shutdown timer
|
|
* @tp_vars: the private data of the current TP meter session
|
|
*
|
|
* start the receiver shutdown timer or reset it if already started
|
|
*/
|
|
static void batadv_tp_reset_receiver_timer(struct batadv_tp_vars *tp_vars)
|
|
{
|
|
mod_timer(&tp_vars->timer,
|
|
jiffies + msecs_to_jiffies(BATADV_TP_RECV_TIMEOUT));
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_receiver_shutdown() - stop a tp meter receiver when timeout is
|
|
* reached without received ack
|
|
* @t: address to timer_list inside tp_vars
|
|
*/
|
|
static void batadv_tp_receiver_shutdown(struct timer_list *t)
|
|
{
|
|
struct batadv_tp_vars *tp_vars = from_timer(tp_vars, t, timer);
|
|
struct batadv_tp_unacked *un, *safe;
|
|
struct batadv_priv *bat_priv;
|
|
|
|
bat_priv = tp_vars->bat_priv;
|
|
|
|
/* if there is recent activity rearm the timer */
|
|
if (!batadv_has_timed_out(tp_vars->last_recv_time,
|
|
BATADV_TP_RECV_TIMEOUT)) {
|
|
/* reset the receiver shutdown timer */
|
|
batadv_tp_reset_receiver_timer(tp_vars);
|
|
return;
|
|
}
|
|
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Shutting down for inactivity (more than %dms) from %pM\n",
|
|
BATADV_TP_RECV_TIMEOUT, tp_vars->other_end);
|
|
|
|
spin_lock_bh(&tp_vars->bat_priv->tp_list_lock);
|
|
hlist_del_rcu(&tp_vars->list);
|
|
spin_unlock_bh(&tp_vars->bat_priv->tp_list_lock);
|
|
|
|
/* drop list reference */
|
|
batadv_tp_vars_put(tp_vars);
|
|
|
|
atomic_dec(&bat_priv->tp_num);
|
|
|
|
spin_lock_bh(&tp_vars->unacked_lock);
|
|
list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) {
|
|
list_del(&un->list);
|
|
kfree(un);
|
|
}
|
|
spin_unlock_bh(&tp_vars->unacked_lock);
|
|
|
|
/* drop reference of timer */
|
|
batadv_tp_vars_put(tp_vars);
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_send_ack() - send an ACK packet
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @dst: the mac address of the destination originator
|
|
* @seq: the sequence number to ACK
|
|
* @timestamp: the timestamp to echo back in the ACK
|
|
* @session: session identifier
|
|
* @socket_index: local ICMP socket identifier
|
|
*
|
|
* Return: 0 on success, a positive integer representing the reason of the
|
|
* failure otherwise
|
|
*/
|
|
static int batadv_tp_send_ack(struct batadv_priv *bat_priv, const u8 *dst,
|
|
u32 seq, __be32 timestamp, const u8 *session,
|
|
int socket_index)
|
|
{
|
|
struct batadv_hard_iface *primary_if = NULL;
|
|
struct batadv_orig_node *orig_node;
|
|
struct batadv_icmp_tp_packet *icmp;
|
|
struct sk_buff *skb;
|
|
int r, ret;
|
|
|
|
orig_node = batadv_orig_hash_find(bat_priv, dst);
|
|
if (unlikely(!orig_node)) {
|
|
ret = BATADV_TP_REASON_DST_UNREACHABLE;
|
|
goto out;
|
|
}
|
|
|
|
primary_if = batadv_primary_if_get_selected(bat_priv);
|
|
if (unlikely(!primary_if)) {
|
|
ret = BATADV_TP_REASON_DST_UNREACHABLE;
|
|
goto out;
|
|
}
|
|
|
|
skb = netdev_alloc_skb_ip_align(NULL, sizeof(*icmp) + ETH_HLEN);
|
|
if (unlikely(!skb)) {
|
|
ret = BATADV_TP_REASON_MEMORY_ERROR;
|
|
goto out;
|
|
}
|
|
|
|
skb_reserve(skb, ETH_HLEN);
|
|
icmp = skb_put(skb, sizeof(*icmp));
|
|
icmp->packet_type = BATADV_ICMP;
|
|
icmp->version = BATADV_COMPAT_VERSION;
|
|
icmp->ttl = BATADV_TTL;
|
|
icmp->msg_type = BATADV_TP;
|
|
ether_addr_copy(icmp->dst, orig_node->orig);
|
|
ether_addr_copy(icmp->orig, primary_if->net_dev->dev_addr);
|
|
icmp->uid = socket_index;
|
|
|
|
icmp->subtype = BATADV_TP_ACK;
|
|
memcpy(icmp->session, session, sizeof(icmp->session));
|
|
icmp->seqno = htonl(seq);
|
|
icmp->timestamp = timestamp;
|
|
|
|
/* send the ack */
|
|
r = batadv_send_skb_to_orig(skb, orig_node, NULL);
|
|
if (unlikely(r < 0) || r == NET_XMIT_DROP) {
|
|
ret = BATADV_TP_REASON_DST_UNREACHABLE;
|
|
goto out;
|
|
}
|
|
ret = 0;
|
|
|
|
out:
|
|
if (likely(orig_node))
|
|
batadv_orig_node_put(orig_node);
|
|
if (likely(primary_if))
|
|
batadv_hardif_put(primary_if);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_handle_out_of_order() - store an out of order packet
|
|
* @tp_vars: the private data of the current TP meter session
|
|
* @skb: the buffer containing the received packet
|
|
*
|
|
* Store the out of order packet in the unacked list for late processing. This
|
|
* packets are kept in this list so that they can be ACKed at once as soon as
|
|
* all the previous packets have been received
|
|
*
|
|
* Return: true if the packed has been successfully processed, false otherwise
|
|
*/
|
|
static bool batadv_tp_handle_out_of_order(struct batadv_tp_vars *tp_vars,
|
|
const struct sk_buff *skb)
|
|
{
|
|
const struct batadv_icmp_tp_packet *icmp;
|
|
struct batadv_tp_unacked *un, *new;
|
|
u32 payload_len;
|
|
bool added = false;
|
|
|
|
new = kmalloc(sizeof(*new), GFP_ATOMIC);
|
|
if (unlikely(!new))
|
|
return false;
|
|
|
|
icmp = (struct batadv_icmp_tp_packet *)skb->data;
|
|
|
|
new->seqno = ntohl(icmp->seqno);
|
|
payload_len = skb->len - sizeof(struct batadv_unicast_packet);
|
|
new->len = payload_len;
|
|
|
|
spin_lock_bh(&tp_vars->unacked_lock);
|
|
/* if the list is empty immediately attach this new object */
|
|
if (list_empty(&tp_vars->unacked_list)) {
|
|
list_add(&new->list, &tp_vars->unacked_list);
|
|
goto out;
|
|
}
|
|
|
|
/* otherwise loop over the list and either drop the packet because this
|
|
* is a duplicate or store it at the right position.
|
|
*
|
|
* The iteration is done in the reverse way because it is likely that
|
|
* the last received packet (the one being processed now) has a bigger
|
|
* seqno than all the others already stored.
|
|
*/
|
|
list_for_each_entry_reverse(un, &tp_vars->unacked_list, list) {
|
|
/* check for duplicates */
|
|
if (new->seqno == un->seqno) {
|
|
if (new->len > un->len)
|
|
un->len = new->len;
|
|
kfree(new);
|
|
added = true;
|
|
break;
|
|
}
|
|
|
|
/* look for the right position */
|
|
if (batadv_seq_before(new->seqno, un->seqno))
|
|
continue;
|
|
|
|
/* as soon as an entry having a bigger seqno is found, the new
|
|
* one is attached _after_ it. In this way the list is kept in
|
|
* ascending order
|
|
*/
|
|
list_add_tail(&new->list, &un->list);
|
|
added = true;
|
|
break;
|
|
}
|
|
|
|
/* received packet with smallest seqno out of order; add it to front */
|
|
if (!added)
|
|
list_add(&new->list, &tp_vars->unacked_list);
|
|
|
|
out:
|
|
spin_unlock_bh(&tp_vars->unacked_lock);
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_ack_unordered() - update number received bytes in current stream
|
|
* without gaps
|
|
* @tp_vars: the private data of the current TP meter session
|
|
*/
|
|
static void batadv_tp_ack_unordered(struct batadv_tp_vars *tp_vars)
|
|
{
|
|
struct batadv_tp_unacked *un, *safe;
|
|
u32 to_ack;
|
|
|
|
/* go through the unacked packet list and possibly ACK them as
|
|
* well
|
|
*/
|
|
spin_lock_bh(&tp_vars->unacked_lock);
|
|
list_for_each_entry_safe(un, safe, &tp_vars->unacked_list, list) {
|
|
/* the list is ordered, therefore it is possible to stop as soon
|
|
* there is a gap between the last acked seqno and the seqno of
|
|
* the packet under inspection
|
|
*/
|
|
if (batadv_seq_before(tp_vars->last_recv, un->seqno))
|
|
break;
|
|
|
|
to_ack = un->seqno + un->len - tp_vars->last_recv;
|
|
|
|
if (batadv_seq_before(tp_vars->last_recv, un->seqno + un->len))
|
|
tp_vars->last_recv += to_ack;
|
|
|
|
list_del(&un->list);
|
|
kfree(un);
|
|
}
|
|
spin_unlock_bh(&tp_vars->unacked_lock);
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_init_recv() - return matching or create new receiver tp_vars
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @icmp: received icmp tp msg
|
|
*
|
|
* Return: corresponding tp_vars or NULL on errors
|
|
*/
|
|
static struct batadv_tp_vars *
|
|
batadv_tp_init_recv(struct batadv_priv *bat_priv,
|
|
const struct batadv_icmp_tp_packet *icmp)
|
|
{
|
|
struct batadv_tp_vars *tp_vars;
|
|
|
|
spin_lock_bh(&bat_priv->tp_list_lock);
|
|
tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig,
|
|
icmp->session);
|
|
if (tp_vars)
|
|
goto out_unlock;
|
|
|
|
if (!atomic_add_unless(&bat_priv->tp_num, 1, BATADV_TP_MAX_NUM)) {
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Meter: too many ongoing sessions, aborting (RECV)\n");
|
|
goto out_unlock;
|
|
}
|
|
|
|
tp_vars = kmalloc(sizeof(*tp_vars), GFP_ATOMIC);
|
|
if (!tp_vars)
|
|
goto out_unlock;
|
|
|
|
ether_addr_copy(tp_vars->other_end, icmp->orig);
|
|
tp_vars->role = BATADV_TP_RECEIVER;
|
|
memcpy(tp_vars->session, icmp->session, sizeof(tp_vars->session));
|
|
tp_vars->last_recv = BATADV_TP_FIRST_SEQ;
|
|
tp_vars->bat_priv = bat_priv;
|
|
kref_init(&tp_vars->refcount);
|
|
|
|
spin_lock_init(&tp_vars->unacked_lock);
|
|
INIT_LIST_HEAD(&tp_vars->unacked_list);
|
|
|
|
kref_get(&tp_vars->refcount);
|
|
hlist_add_head_rcu(&tp_vars->list, &bat_priv->tp_list);
|
|
|
|
kref_get(&tp_vars->refcount);
|
|
timer_setup(&tp_vars->timer, batadv_tp_receiver_shutdown, 0);
|
|
|
|
batadv_tp_reset_receiver_timer(tp_vars);
|
|
|
|
out_unlock:
|
|
spin_unlock_bh(&bat_priv->tp_list_lock);
|
|
|
|
return tp_vars;
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_recv_msg() - process a single data message
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @skb: the buffer containing the received packet
|
|
*
|
|
* Process a received TP MSG packet
|
|
*/
|
|
static void batadv_tp_recv_msg(struct batadv_priv *bat_priv,
|
|
const struct sk_buff *skb)
|
|
{
|
|
const struct batadv_icmp_tp_packet *icmp;
|
|
struct batadv_tp_vars *tp_vars;
|
|
size_t packet_size;
|
|
u32 seqno;
|
|
|
|
icmp = (struct batadv_icmp_tp_packet *)skb->data;
|
|
|
|
seqno = ntohl(icmp->seqno);
|
|
/* check if this is the first seqno. This means that if the
|
|
* first packet is lost, the tp meter does not work anymore!
|
|
*/
|
|
if (seqno == BATADV_TP_FIRST_SEQ) {
|
|
tp_vars = batadv_tp_init_recv(bat_priv, icmp);
|
|
if (!tp_vars) {
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Meter: seqno != BATADV_TP_FIRST_SEQ cannot initiate connection\n");
|
|
goto out;
|
|
}
|
|
} else {
|
|
tp_vars = batadv_tp_list_find_session(bat_priv, icmp->orig,
|
|
icmp->session);
|
|
if (!tp_vars) {
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Unexpected packet from %pM!\n",
|
|
icmp->orig);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (unlikely(tp_vars->role != BATADV_TP_RECEIVER)) {
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Meter: dropping packet: not expected (role=%u)\n",
|
|
tp_vars->role);
|
|
goto out;
|
|
}
|
|
|
|
tp_vars->last_recv_time = jiffies;
|
|
|
|
/* if the packet is a duplicate, it may be the case that an ACK has been
|
|
* lost. Resend the ACK
|
|
*/
|
|
if (batadv_seq_before(seqno, tp_vars->last_recv))
|
|
goto send_ack;
|
|
|
|
/* if the packet is out of order enqueue it */
|
|
if (ntohl(icmp->seqno) != tp_vars->last_recv) {
|
|
/* exit immediately (and do not send any ACK) if the packet has
|
|
* not been enqueued correctly
|
|
*/
|
|
if (!batadv_tp_handle_out_of_order(tp_vars, skb))
|
|
goto out;
|
|
|
|
/* send a duplicate ACK */
|
|
goto send_ack;
|
|
}
|
|
|
|
/* if everything was fine count the ACKed bytes */
|
|
packet_size = skb->len - sizeof(struct batadv_unicast_packet);
|
|
tp_vars->last_recv += packet_size;
|
|
|
|
/* check if this ordered message filled a gap.... */
|
|
batadv_tp_ack_unordered(tp_vars);
|
|
|
|
send_ack:
|
|
/* send the ACK. If the received packet was out of order, the ACK that
|
|
* is going to be sent is a duplicate (the sender will count them and
|
|
* possibly enter Fast Retransmit as soon as it has reached 3)
|
|
*/
|
|
batadv_tp_send_ack(bat_priv, icmp->orig, tp_vars->last_recv,
|
|
icmp->timestamp, icmp->session, icmp->uid);
|
|
out:
|
|
if (likely(tp_vars))
|
|
batadv_tp_vars_put(tp_vars);
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_meter_recv() - main TP Meter receiving function
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @skb: the buffer containing the received packet
|
|
*/
|
|
void batadv_tp_meter_recv(struct batadv_priv *bat_priv, struct sk_buff *skb)
|
|
{
|
|
struct batadv_icmp_tp_packet *icmp;
|
|
|
|
icmp = (struct batadv_icmp_tp_packet *)skb->data;
|
|
|
|
switch (icmp->subtype) {
|
|
case BATADV_TP_MSG:
|
|
batadv_tp_recv_msg(bat_priv, skb);
|
|
break;
|
|
case BATADV_TP_ACK:
|
|
batadv_tp_recv_ack(bat_priv, skb);
|
|
break;
|
|
default:
|
|
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
|
|
"Received unknown TP Metric packet type %u\n",
|
|
icmp->subtype);
|
|
}
|
|
consume_skb(skb);
|
|
}
|
|
|
|
/**
|
|
* batadv_tp_meter_init() - initialize global tp_meter structures
|
|
*/
|
|
void __init batadv_tp_meter_init(void)
|
|
{
|
|
get_random_bytes(batadv_tp_prerandom, sizeof(batadv_tp_prerandom));
|
|
}
|