Release 4.11 net/batman-adv/tp_meter.c
/* Copyright (C) 2012-2017 B.A.T.M.A.N. contributors:
*
* Edo Monticelli, Antonio Quartulli
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "tp_meter.h"
#include "main.h"
#include <linux/atomic.h>
#include <linux/bug.h>
#include <linux/byteorder/generic.h>
#include <linux/cache.h>
#include <linux/compiler.h>
#include <linux/err.h>
#include <linux/etherdevice.h>
#include <linux/fs.h>
#include <linux/if_ether.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/kthread.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/param.h>
#include <linux/printk.h>
#include <linux/random.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/sched.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <uapi/linux/batman_adv.h>
#include "hard-interface.h"
#include "log.h"
#include "netlink.h"
#include "originator.h"
#include "packet.h"
#include "send.h"
/**
* BATADV_TP_DEF_TEST_LENGTH - Default test length if not specified by the user
* in milliseconds
*/
#define BATADV_TP_DEF_TEST_LENGTH 10000
/**
* BATADV_TP_AWND - Advertised window by the receiver (in bytes)
*/
#define BATADV_TP_AWND 0x20000000
/**
* BATADV_TP_RECV_TIMEOUT - Receiver activity timeout. If the receiver does not
* get anything for such amount of milliseconds, the connection is killed
*/
#define BATADV_TP_RECV_TIMEOUT 1000
/**
* BATADV_TP_MAX_RTO - Maximum sender timeout. If the sender RTO gets beyond
* such amound of milliseconds, the receiver is considered unreachable and the
* connection is killed
*/
#define BATADV_TP_MAX_RTO 30000
/**
* BATADV_TP_FIRST_SEQ - First seqno of each session. The number is rather high
* in order to immediately trigger a wrap around (test purposes)
*/
#define BATADV_TP_FIRST_SEQ ((u32)-1 - 2000)
/**
* BATADV_TP_PLEN - length of the payload (data after the batadv_unicast header)
* to simulate
*/
#define BATADV_TP_PLEN (BATADV_TP_PACKET_LEN - ETH_HLEN - \
sizeof(struct batadv_unicast_packet))
static u8 batadv_tp_prerandom[4096] __read_mostly;
/**
* batadv_tp_session_cookie - generate session cookie based on session ids
* @session: TP session identifier
* @icmp_uid: icmp pseudo uid of the tp session
*
* Return: 32 bit tp_meter session cookie
*/
static u32 batadv_tp_session_cookie(const u8 session[2], u8 icmp_uid)
{
u32 cookie;
cookie = icmp_uid << 16;
cookie |= session[0] << 8;
cookie |= session[1];
return cookie;
}
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/**
* batadv_tp_cwnd - compute the new cwnd size
* @base: base cwnd size value
* @increment: the value to add to base to get the new size
* @min: minumim cwnd value (usually MSS)
*
* Return the new cwnd size and ensures it does not exceed the Advertised
* Receiver Window size. It is wrap around safe.
* For details refer to Section 3.1 of RFC5681
*
* Return: new congestion window size in bytes
*/
static u32 batadv_tp_cwnd(u32 base, u32 increment, u32 min)
{
u32 new_size = base + increment;
/* check for wrap-around */
if (new_size < base)
new_size = (u32)ULONG_MAX;
new_size = min_t(u32, new_size, BATADV_TP_AWND);
return max_t(u32, new_size, min);
}
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/**
* batadv_tp_updated_cwnd - update the Congestion Windows
* @tp_vars: the private data of the current TP meter session
* @mss: maximum segment size of transmission
*
* 1) if the session is in Slow Start, the CWND has to be increased by 1
* MSS every unique received ACK
* 2) if the session is in Congestion Avoidance, the CWND has to be
* increased by MSS * MSS / CWND for every unique received ACK
*/
static void batadv_tp_update_cwnd(struct batadv_tp_vars *tp_vars, u32 mss)
{
spin_lock_bh(&tp_vars->cwnd_lock);
/* slow start... */
if (tp_vars->cwnd <= tp_vars->ss_threshold) {
tp_vars->dec_cwnd = 0;
tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, mss, mss);
spin_unlock_bh(&tp_vars->cwnd_lock);
return;
}
/* increment CWND at least of 1 (section 3.1 of RFC5681) */
tp_vars->dec_cwnd += max_t(u32, 1U << 3,
((mss * mss) << 6) / (tp_vars->cwnd << 3));
if (tp_vars->dec_cwnd < (mss << 3)) {
spin_unlock_bh(&tp_vars->cwnd_lock);
return;
}
tp_vars->cwnd = batadv_tp_cwnd(tp_vars->cwnd, mss, mss);
tp_vars->dec_cwnd = 0;
spin_unlock_bh(&tp_vars->cwnd_lock);
}
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/**
* batadv_tp_update_rto - calculate new retransmission timeout
* @tp_vars: the private data of the current TP meter session
* @new_rtt: new roundtrip time in msec
*/
static void batadv_tp_update_rto(struct batadv_tp_vars *tp_vars,
u32 new_rtt)
{
long m = new_rtt;
/* RTT update
* Details in Section 2.2 and 2.3 of RFC6298
*
* It's tricky to understand. Don't lose hair please.
* Inspired by tcp_rtt_estimator() tcp_input.c
*/
if (tp_vars->srtt != 0) {
m -= (tp_vars->srtt >> 3); /* m is now error in rtt est */
tp_vars->srtt += m; /* rtt = 7/8 srtt + 1/8 new */
if (m < 0)
m = -m;
m -= (tp_vars->rttvar >> 2);
tp_vars->rttvar += m; /* mdev ~= 3/4 rttvar + 1/4 new */
} else {
/* first measure getting in */
tp_vars->srtt = m << 3; /* take the measured time to be srtt */
tp_vars->rttvar = m << 1; /* new_rtt / 2 */
}
/* rto = srtt + 4 * rttvar.
* rttvar is scaled by 4, therefore doesn't need to be multiplied
*/
tp_vars->rto = (tp_vars->srtt >> 3) + tp_vars->rttvar;
}
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/**
* batadv_tp_batctl_notify - send client status result to client
* @reason: reason for tp meter session stop
* @dst: destination of tp_meter session
* @bat_priv: the bat priv with all the soft interface information
* @start_time: start of transmission in jiffies
* @total_sent: bytes acked to the receiver
* @cookie: cookie of tp_meter session
*/
static void batadv_tp_batctl_notify(enum batadv_tp_meter_reason reason,
const u8 *dst, struct batadv_priv *bat_priv,
unsigned long start_time, u64 total_sent,
u32 cookie)
{
u32 test_time;
u8 result;
u32 total_bytes;
if (!batadv_tp_is_error(reason)) {
result = BATADV_TP_REASON_COMPLETE;
test_time = jiffies_to_msecs(jiffies - start_time);
total_bytes = total_sent;
} else {
result = reason;
test_time = 0;
total_bytes = 0;
}
batadv_netlink_tpmeter_notify(bat_priv, dst, result, test_time,
total_bytes, cookie);
}
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/**
* batadv_tp_batctl_error_notify - send client error result to client
* @reason: reason for tp meter session stop
* @dst: destination of tp_meter session
* @bat_priv: the bat priv with all the soft interface information
* @cookie: cookie of tp_meter session
*/
static void batadv_tp_batctl_error_notify(enum batadv_tp_meter_reason reason,
const u8 *dst,
struct batadv_priv *bat_priv,
u32 cookie)
{
batadv_tp_batctl_notify(reason, dst, bat_priv, 0, 0, cookie);
}
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/**
* batadv_tp_list_find - find a tp_vars object in the global list
* @bat_priv: the bat priv with all the soft interface information
* @dst: the other endpoint MAC address to look for
*
* Look for a tp_vars object matching dst as end_point and return it after
* having incremented the refcounter. Return NULL is not found
*
* Return: matching tp_vars or NULL when no tp_vars with @dst was found
*/
static struct batadv_tp_vars *batadv_tp_list_find(struct batadv_priv *bat_priv,
const u8 *dst)
{
struct batadv_tp_vars *pos, *tp_vars = NULL;
rcu_read_lock();
hlist_for_each_entry_rcu(pos, &bat_priv->tp_list, list) {
if (!batadv_compare_eth(pos->other_end, dst))
continue;
/* most of the time this function is invoked during the normal
* process..it makes sens to pay more when the session is
* finished and to speed the process up during the measurement
*/
if (unlikely(!kref_get_unless_zero(&pos->refcount)))
continue;
tp_vars = pos;
break;
}
rcu_read_unlock();
return tp_vars;
}
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/**
* batadv_tp_list_find_session - find tp_vars session object in the global list
* @bat_priv: the bat priv with all the soft interface information
* @dst: the other endpoint MAC address to look for
* @session: session identifier
*
* Look for a tp_vars object matching dst as end_point, session as tp meter
* session and return it after having incremented the refcounter. Return NULL
* is not found
*
* Return: matching tp_vars or NULL when no tp_vars was found
*/
static struct batadv_tp_vars *
batadv_tp_list_find_session(struct batadv_priv *bat_priv, const u8 *dst,
const u8 *session)
{
struct batadv_tp_vars *pos, *tp_vars = NULL;
rcu_read_lock();
hlist_for_each_entry_rcu(pos, &bat_priv->tp_list, list) {
if (!batadv_compare_eth(pos->other_end, dst))
continue;
if (memcmp(pos->session, session, sizeof(pos->session)) != 0)
continue;
/* most of the time this function is invoked during the normal
* process..it makes sense to pay more when the session is
* finished and to speed the process up during the measurement
*/
if (unlikely(!kref_get_unless_zero(&pos->refcount)))
continue;
tp_vars = pos;
break;
}
rcu_read_unlock();
return tp_vars;
}
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/**
* batadv_tp_vars_release - release batadv_tp_vars from lists and queue for
* free after rcu grace period
* @ref: kref pointer of the batadv_tp_vars
*/
static void batadv_tp_vars_release(struct kref *ref)
{
struct batadv_tp_vars *tp_vars;
struct batadv_tp_unacked *un, *safe;
tp_vars = container_of(ref, struct batadv_tp_vars, refcount);
/* lock should not be needed because this object is now out of any
* context!
*/
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);
kfree_rcu(tp_vars, rcu);
}
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/**
* batadv_tp_vars_put - decrement the batadv_tp_vars refcounter and possibly
* release it
* @tp_vars: the private data of the current TP meter session to be free'd
*/
static void batadv_tp_vars_put(struct batadv_tp_vars *tp_vars)
{
kref_put(&tp_vars->refcount, batadv_tp_vars_release);
}
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/**
* batadv_tp_sender_cleanup - cleanup sender data and drop and timer
* @bat_priv: the bat priv with all the soft interface information
* @tp_vars: the private data of the current TP meter session to cleanup
*/
static void batadv_tp_sender_cleanup(struct batadv_priv *bat_priv,
struct batadv_tp_vars *tp_vars)
{
cancel_delayed_work(&tp_vars->finish_work);
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(&tp_vars->bat_priv->tp_num);
/* kill the timer and remove its reference */
del_timer_sync(&tp_vars->timer);
/* the worker might have rearmed itself therefore we kill it again. Note
* that if the worker should run again before invoking the following
* del_timer(), it would not re-arm itself once again because the status
* is OFF now
*/
del_timer(&tp_vars->timer);
batadv_tp_vars_put(tp_vars);
}
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/**
* batadv_tp_sender_end - print info about ended session and inform client
* @bat_priv: the bat priv with all the soft interface information
* @tp_vars: the private data of the current TP meter session
*/
static void batadv_tp_sender_end(struct batadv_priv *bat_priv,
struct batadv_tp_vars *tp_vars)
{
u32 session_cookie;
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
"Test towards %pM finished..shutting down (reason=%d)\n",
tp_vars->other_end, tp_vars->reason);
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
"Last timing stats: SRTT=%ums RTTVAR=%ums RTO=%ums\n",
tp_vars->srtt >> 3, tp_vars->rttvar >> 2, tp_vars->rto);
batadv_dbg(BATADV_DBG_TP_METER, bat_priv,
"Final values: cwnd=%u ss_threshold=%u\n",
tp_vars->cwnd, tp_vars->ss_threshold);
session_cookie = batadv_tp_session_cookie(tp_vars->session,
tp_vars->icmp_uid);
batadv_tp_batctl_notify(tp_vars->reason,
tp_vars->other_end,
bat_priv,
tp_vars->start_time,
atomic64_read(&tp_vars->tot_sent),
session_cookie);
}
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/**
* batadv_tp_sender_shutdown - let sender thread/timer stop gracefully
* @tp_vars: the private data of the current TP meter session
* @reason: reason for tp meter session stop
*/
static void batadv_tp_sender_shutdown(struct batadv_tp_vars *tp_vars,
enum batadv_tp_meter_reason reason)
{
if (!atomic_dec_and_test(&tp_vars->sending))
return;
tp_vars->reason = reason;
}
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/**
* batadv_tp_sender_finish - stop sender session after test_length was reached
* @work: delayed work reference of the related tp_vars
*/
static void batadv_tp_sender_finish(struct work_struct *work)
{
struct delayed_work *delayed_work;
struct batadv_tp_vars *tp_vars;
delayed_work = to_delayed_work(work);
tp_vars = container_of(delayed_work, struct batadv_tp_vars,
finish_work);
batadv_tp_sender_shutdown(tp_vars, BATADV_TP_REASON_COMPLETE);
}
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/**
* batadv_tp_reset_sender_timer - reschedule the sender timer
* @tp_vars: the private TP meter data for this session
*
* Reschedule the timer using tp_vars->rto as delay
*/
static void batadv_tp_reset_sender_timer(struct batadv_tp_vars *tp_vars)
{
/* most of the time this function is invoked while normal packet
* reception...
*/
if (unlikely(atomic_read(&tp_vars->sending) == 0))
/* timer ref will be dropped in batadv_tp_sender_cleanup */
return;
mod_timer(&tp_vars->timer, jiffies + msecs_to_jiffies(tp_vars->rto));
}
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/**
* batadv_tp_sender_timeout - timer that fires in case of packet loss
* @arg: address of the related tp_vars
*
* 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(unsigned long arg)
{
struct batadv_tp_vars *tp_vars = (struct batadv_tp_vars *)arg;
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);
}
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/**
* 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;
}
}
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/**
* 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 = (struct batadv_icmp_tp_packet *)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 = (u8 *)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;
}
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/**
* 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);
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
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/**
* 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;
}
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Person | Tokens | Prop | Commits | CommitProp |
Antonio Quartulli | 46 | 100.00% | 1 | 100.00% |
Total | 46 | 100.00% | 1 | 100.00% |
/**
* 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;
}
Contributors
Person | Tokens | Prop | Commits | CommitProp |
Antonio Quartulli | 40 | 100.00% | 1 | 100.00% |
Total | 40 | 100.00% | 1 | 100.00% |
/**
* 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: batadv_tp_send() cannot send packets (%d)\n",
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);
}
Contributors
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Total | 369 | 100.00% | 2 | 100.00% |
/**
* 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,