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1490 lines
42 KiB
1490 lines
42 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* Copyright (C) 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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|
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#include "tp_meter.h" |
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#include "main.h" |
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|
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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/limits.h> |
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#include <linux/list.h> |
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#include <linux/minmax.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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/** |
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* BATADV_TP_MAX_RTO - Maximum sender timeout. If the sender RTO gets beyond |
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* such amount 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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/** |
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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: minimum cwnd value (usually MSS) |
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* |
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* Return the new cwnd size and ensure it does not exceed the Advertised |
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* Receiver Window size. It is wrapped around safely. |
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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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|
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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_update_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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|
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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 increment 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 increment 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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|
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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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if (!tp_vars) |
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return; |
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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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|
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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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/** |
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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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/** |
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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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|
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tp_vars->reason = reason; |
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} |
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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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|
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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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|
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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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/** |
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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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|
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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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/** |
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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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* |
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* If fired it means that there was packet loss. |
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* Switch to Slow Start, set the ss_threshold to half of the current cwnd and |
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* reset the cwnd to 3*MSS |
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*/ |
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static void batadv_tp_sender_timeout(struct timer_list *t) |
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{ |
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struct batadv_tp_vars *tp_vars = from_timer(tp_vars, t, timer); |
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struct batadv_priv *bat_priv = tp_vars->bat_priv; |
|
|
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if (atomic_read(&tp_vars->sending) == 0) |
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return; |
|
|
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/* if the user waited long enough...shutdown the test */ |
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if (unlikely(tp_vars->rto >= BATADV_TP_MAX_RTO)) { |
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batadv_tp_sender_shutdown(tp_vars, |
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BATADV_TP_REASON_DST_UNREACHABLE); |
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return; |
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} |
|
|
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/* RTO exponential backoff |
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* Details in Section 5.5 of RFC6298 |
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*/ |
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tp_vars->rto <<= 1; |
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|
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spin_lock_bh(&tp_vars->cwnd_lock); |
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|
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tp_vars->ss_threshold = tp_vars->cwnd >> 1; |
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if (tp_vars->ss_threshold < BATADV_TP_PLEN * 2) |
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tp_vars->ss_threshold = BATADV_TP_PLEN * 2; |
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|
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batadv_dbg(BATADV_DBG_TP_METER, bat_priv, |
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"Meter: RTO fired during test towards %pM! cwnd=%u new ss_thr=%u, resetting last_sent to %u\n", |
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tp_vars->other_end, tp_vars->cwnd, tp_vars->ss_threshold, |
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atomic_read(&tp_vars->last_acked)); |
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|
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tp_vars->cwnd = BATADV_TP_PLEN * 3; |
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|
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spin_unlock_bh(&tp_vars->cwnd_lock); |
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|
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/* resend the non-ACKed packets.. */ |
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tp_vars->last_sent = atomic_read(&tp_vars->last_acked); |
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wake_up(&tp_vars->more_bytes); |
|
|
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batadv_tp_reset_sender_timer(tp_vars); |
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} |
|
|
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/** |
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* batadv_tp_fill_prerandom() - Fill buffer with prefetched random bytes |
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* @tp_vars: the private TP meter data for this session |
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* @buf: Buffer to fill with bytes |
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* @nbytes: amount of pseudorandom bytes |
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*/ |
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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: |
|
batadv_hardif_put(primary_if); |
|
batadv_orig_node_put(orig_node); |
|
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: |
|
batadv_hardif_put(primary_if); |
|
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: |
|
batadv_orig_node_put(orig_node); |
|
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: |
|
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)); |
|
}
|
|
|