linux/net/batman-adv/send.c
Antonio Quartulli 66a1b2bcb3 batman-adv: convert bat_priv->tt_crc from atomic_t to uint16_t
In the code we neever need to atomically check and set the bat_priv->tt_crc
field value. It is simply set and read once in different pieces of the code.
Therefore this field can be safely be converted from atomic_t to uint16_t.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
2012-06-18 18:00:58 +02:00

411 lines
11 KiB
C

/*
* Copyright (C) 2007-2012 B.A.T.M.A.N. contributors:
*
* Marek Lindner, Simon Wunderlich
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*
*/
#include "main.h"
#include "send.h"
#include "routing.h"
#include "translation-table.h"
#include "soft-interface.h"
#include "hard-interface.h"
#include "vis.h"
#include "gateway_common.h"
#include "originator.h"
static void send_outstanding_bcast_packet(struct work_struct *work);
/* send out an already prepared packet to the given address via the
* specified batman interface */
int send_skb_packet(struct sk_buff *skb, struct hard_iface *hard_iface,
const uint8_t *dst_addr)
{
struct ethhdr *ethhdr;
if (hard_iface->if_status != IF_ACTIVE)
goto send_skb_err;
if (unlikely(!hard_iface->net_dev))
goto send_skb_err;
if (!(hard_iface->net_dev->flags & IFF_UP)) {
pr_warn("Interface %s is not up - can't send packet via that interface!\n",
hard_iface->net_dev->name);
goto send_skb_err;
}
/* push to the ethernet header. */
if (my_skb_head_push(skb, ETH_HLEN) < 0)
goto send_skb_err;
skb_reset_mac_header(skb);
ethhdr = (struct ethhdr *)skb_mac_header(skb);
memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
skb_set_network_header(skb, ETH_HLEN);
skb->priority = TC_PRIO_CONTROL;
skb->protocol = __constant_htons(ETH_P_BATMAN);
skb->dev = hard_iface->net_dev;
/* dev_queue_xmit() returns a negative result on error. However on
* congestion and traffic shaping, it drops and returns NET_XMIT_DROP
* (which is > 0). This will not be treated as an error. */
return dev_queue_xmit(skb);
send_skb_err:
kfree_skb(skb);
return NET_XMIT_DROP;
}
static void realloc_packet_buffer(struct hard_iface *hard_iface,
int new_len)
{
unsigned char *new_buff;
new_buff = kmalloc(new_len, GFP_ATOMIC);
/* keep old buffer if kmalloc should fail */
if (new_buff) {
memcpy(new_buff, hard_iface->packet_buff,
BATMAN_OGM_HLEN);
kfree(hard_iface->packet_buff);
hard_iface->packet_buff = new_buff;
hard_iface->packet_len = new_len;
}
}
/* when calling this function (hard_iface == primary_if) has to be true */
static int prepare_packet_buffer(struct bat_priv *bat_priv,
struct hard_iface *hard_iface)
{
int new_len;
new_len = BATMAN_OGM_HLEN +
tt_len((uint8_t)atomic_read(&bat_priv->tt_local_changes));
/* if we have too many changes for one packet don't send any
* and wait for the tt table request which will be fragmented */
if (new_len > hard_iface->soft_iface->mtu)
new_len = BATMAN_OGM_HLEN;
realloc_packet_buffer(hard_iface, new_len);
bat_priv->tt_crc = tt_local_crc(bat_priv);
/* reset the sending counter */
atomic_set(&bat_priv->tt_ogm_append_cnt, TT_OGM_APPEND_MAX);
return tt_changes_fill_buffer(bat_priv,
hard_iface->packet_buff + BATMAN_OGM_HLEN,
hard_iface->packet_len - BATMAN_OGM_HLEN);
}
static int reset_packet_buffer(struct bat_priv *bat_priv,
struct hard_iface *hard_iface)
{
realloc_packet_buffer(hard_iface, BATMAN_OGM_HLEN);
return 0;
}
void schedule_bat_ogm(struct hard_iface *hard_iface)
{
struct bat_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
struct hard_iface *primary_if;
int tt_num_changes = -1;
if ((hard_iface->if_status == IF_NOT_IN_USE) ||
(hard_iface->if_status == IF_TO_BE_REMOVED))
return;
/**
* the interface gets activated here to avoid race conditions between
* the moment of activating the interface in
* hardif_activate_interface() where the originator mac is set and
* outdated packets (especially uninitialized mac addresses) in the
* packet queue
*/
if (hard_iface->if_status == IF_TO_BE_ACTIVATED)
hard_iface->if_status = IF_ACTIVE;
primary_if = primary_if_get_selected(bat_priv);
if (hard_iface == primary_if) {
/* if at least one change happened */
if (atomic_read(&bat_priv->tt_local_changes) > 0) {
tt_commit_changes(bat_priv);
tt_num_changes = prepare_packet_buffer(bat_priv,
hard_iface);
}
/* if the changes have been sent often enough */
if (!atomic_dec_not_zero(&bat_priv->tt_ogm_append_cnt))
tt_num_changes = reset_packet_buffer(bat_priv,
hard_iface);
}
if (primary_if)
hardif_free_ref(primary_if);
bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface, tt_num_changes);
}
static void forw_packet_free(struct forw_packet *forw_packet)
{
if (forw_packet->skb)
kfree_skb(forw_packet->skb);
if (forw_packet->if_incoming)
hardif_free_ref(forw_packet->if_incoming);
kfree(forw_packet);
}
static void _add_bcast_packet_to_list(struct bat_priv *bat_priv,
struct forw_packet *forw_packet,
unsigned long send_time)
{
INIT_HLIST_NODE(&forw_packet->list);
/* add new packet to packet list */
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list);
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
/* start timer for this packet */
INIT_DELAYED_WORK(&forw_packet->delayed_work,
send_outstanding_bcast_packet);
queue_delayed_work(bat_event_workqueue, &forw_packet->delayed_work,
send_time);
}
/* add a broadcast packet to the queue and setup timers. broadcast packets
* are sent multiple times to increase probability for being received.
*
* This function returns NETDEV_TX_OK on success and NETDEV_TX_BUSY on
* errors.
*
* The skb is not consumed, so the caller should make sure that the
* skb is freed. */
int add_bcast_packet_to_list(struct bat_priv *bat_priv,
const struct sk_buff *skb, unsigned long delay)
{
struct hard_iface *primary_if = NULL;
struct forw_packet *forw_packet;
struct bcast_packet *bcast_packet;
struct sk_buff *newskb;
if (!atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
bat_dbg(DBG_BATMAN, bat_priv, "bcast packet queue full\n");
goto out;
}
primary_if = primary_if_get_selected(bat_priv);
if (!primary_if)
goto out_and_inc;
forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
if (!forw_packet)
goto out_and_inc;
newskb = skb_copy(skb, GFP_ATOMIC);
if (!newskb)
goto packet_free;
/* as we have a copy now, it is safe to decrease the TTL */
bcast_packet = (struct bcast_packet *)newskb->data;
bcast_packet->header.ttl--;
skb_reset_mac_header(newskb);
forw_packet->skb = newskb;
forw_packet->if_incoming = primary_if;
/* how often did we send the bcast packet ? */
forw_packet->num_packets = 0;
_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
return NETDEV_TX_OK;
packet_free:
kfree(forw_packet);
out_and_inc:
atomic_inc(&bat_priv->bcast_queue_left);
out:
if (primary_if)
hardif_free_ref(primary_if);
return NETDEV_TX_BUSY;
}
static void send_outstanding_bcast_packet(struct work_struct *work)
{
struct hard_iface *hard_iface;
struct delayed_work *delayed_work =
container_of(work, struct delayed_work, work);
struct forw_packet *forw_packet =
container_of(delayed_work, struct forw_packet, delayed_work);
struct sk_buff *skb1;
struct net_device *soft_iface = forw_packet->if_incoming->soft_iface;
struct bat_priv *bat_priv = netdev_priv(soft_iface);
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
hlist_del(&forw_packet->list);
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
goto out;
/* rebroadcast packet */
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &hardif_list, list) {
if (hard_iface->soft_iface != soft_iface)
continue;
/* send a copy of the saved skb */
skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
if (skb1)
send_skb_packet(skb1, hard_iface, broadcast_addr);
}
rcu_read_unlock();
forw_packet->num_packets++;
/* if we still have some more bcasts to send */
if (forw_packet->num_packets < 3) {
_add_bcast_packet_to_list(bat_priv, forw_packet,
msecs_to_jiffies(5));
return;
}
out:
forw_packet_free(forw_packet);
atomic_inc(&bat_priv->bcast_queue_left);
}
void send_outstanding_bat_ogm_packet(struct work_struct *work)
{
struct delayed_work *delayed_work =
container_of(work, struct delayed_work, work);
struct forw_packet *forw_packet =
container_of(delayed_work, struct forw_packet, delayed_work);
struct bat_priv *bat_priv;
bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
spin_lock_bh(&bat_priv->forw_bat_list_lock);
hlist_del(&forw_packet->list);
spin_unlock_bh(&bat_priv->forw_bat_list_lock);
if (atomic_read(&bat_priv->mesh_state) == MESH_DEACTIVATING)
goto out;
bat_priv->bat_algo_ops->bat_ogm_emit(forw_packet);
/**
* we have to have at least one packet in the queue
* to determine the queues wake up time unless we are
* shutting down
*/
if (forw_packet->own)
schedule_bat_ogm(forw_packet->if_incoming);
out:
/* don't count own packet */
if (!forw_packet->own)
atomic_inc(&bat_priv->batman_queue_left);
forw_packet_free(forw_packet);
}
void purge_outstanding_packets(struct bat_priv *bat_priv,
const struct hard_iface *hard_iface)
{
struct forw_packet *forw_packet;
struct hlist_node *tmp_node, *safe_tmp_node;
bool pending;
if (hard_iface)
bat_dbg(DBG_BATMAN, bat_priv,
"purge_outstanding_packets(): %s\n",
hard_iface->net_dev->name);
else
bat_dbg(DBG_BATMAN, bat_priv,
"purge_outstanding_packets()\n");
/* free bcast list */
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
&bat_priv->forw_bcast_list, list) {
/**
* if purge_outstanding_packets() was called with an argument
* we delete only packets belonging to the given interface
*/
if ((hard_iface) &&
(forw_packet->if_incoming != hard_iface))
continue;
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
/**
* send_outstanding_bcast_packet() will lock the list to
* delete the item from the list
*/
pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
if (pending) {
hlist_del(&forw_packet->list);
forw_packet_free(forw_packet);
}
}
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
/* free batman packet list */
spin_lock_bh(&bat_priv->forw_bat_list_lock);
hlist_for_each_entry_safe(forw_packet, tmp_node, safe_tmp_node,
&bat_priv->forw_bat_list, list) {
/**
* if purge_outstanding_packets() was called with an argument
* we delete only packets belonging to the given interface
*/
if ((hard_iface) &&
(forw_packet->if_incoming != hard_iface))
continue;
spin_unlock_bh(&bat_priv->forw_bat_list_lock);
/**
* send_outstanding_bat_packet() will lock the list to
* delete the item from the list
*/
pending = cancel_delayed_work_sync(&forw_packet->delayed_work);
spin_lock_bh(&bat_priv->forw_bat_list_lock);
if (pending) {
hlist_del(&forw_packet->list);
forw_packet_free(forw_packet);
}
}
spin_unlock_bh(&bat_priv->forw_bat_list_lock);
}