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tegrakernel/kernel/kernel-4.9/net/batman-adv/send.c

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/* Copyright (C) 2007-2016 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, see <http://www.gnu.org/licenses/>.
*/
#include "send.h"
#include "main.h"
#include <linux/atomic.h>
#include <linux/byteorder/generic.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/fs.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/printk.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/workqueue.h>
#include "distributed-arp-table.h"
#include "fragmentation.h"
#include "gateway_client.h"
#include "hard-interface.h"
#include "log.h"
#include "network-coding.h"
#include "originator.h"
#include "routing.h"
#include "soft-interface.h"
#include "translation-table.h"
static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
/**
* batadv_send_skb_packet - send an already prepared packet
* @skb: the packet to send
* @hard_iface: the interface to use to send the broadcast packet
* @dst_addr: the payload destination
*
* Send out an already prepared packet to the given neighbor or broadcast it
* using the specified interface. Either hard_iface or neigh_node must be not
* NULL.
* If neigh_node is NULL, then the packet is broadcasted using hard_iface,
* otherwise it is sent as unicast to the given neighbor.
*
* Return: NET_TX_DROP in case of error or the result of dev_queue_xmit(skb)
* otherwise
*/
int batadv_send_skb_packet(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface,
const u8 *dst_addr)
{
struct batadv_priv *bat_priv;
struct ethhdr *ethhdr;
int ret;
bat_priv = netdev_priv(hard_iface->soft_iface);
if (hard_iface->if_status != BATADV_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 (batadv_skb_head_push(skb, ETH_HLEN) < 0)
goto send_skb_err;
skb_reset_mac_header(skb);
ethhdr = eth_hdr(skb);
ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr);
ether_addr_copy(ethhdr->h_dest, dst_addr);
ethhdr->h_proto = htons(ETH_P_BATMAN);
skb_set_network_header(skb, ETH_HLEN);
skb->protocol = htons(ETH_P_BATMAN);
skb->dev = hard_iface->net_dev;
/* Save a clone of the skb to use when decoding coded packets */
batadv_nc_skb_store_for_decoding(bat_priv, skb);
/* 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.
*
* a negative value cannot be returned because it could be interepreted
* as not consumed skb by callers of batadv_send_skb_to_orig.
*/
ret = dev_queue_xmit(skb);
if (ret < 0)
ret = NET_XMIT_DROP;
return ret;
send_skb_err:
kfree_skb(skb);
return NET_XMIT_DROP;
}
int batadv_send_broadcast_skb(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface)
{
return batadv_send_skb_packet(skb, hard_iface, batadv_broadcast_addr);
}
int batadv_send_unicast_skb(struct sk_buff *skb,
struct batadv_neigh_node *neigh)
{
#ifdef CONFIG_BATMAN_ADV_BATMAN_V
struct batadv_hardif_neigh_node *hardif_neigh;
#endif
int ret;
ret = batadv_send_skb_packet(skb, neigh->if_incoming, neigh->addr);
#ifdef CONFIG_BATMAN_ADV_BATMAN_V
hardif_neigh = batadv_hardif_neigh_get(neigh->if_incoming, neigh->addr);
if ((hardif_neigh) && (ret != NET_XMIT_DROP))
hardif_neigh->bat_v.last_unicast_tx = jiffies;
if (hardif_neigh)
batadv_hardif_neigh_put(hardif_neigh);
#endif
return ret;
}
/**
* batadv_send_skb_to_orig - Lookup next-hop and transmit skb.
* @skb: Packet to be transmitted.
* @orig_node: Final destination of the packet.
* @recv_if: Interface used when receiving the packet (can be NULL).
*
* Looks up the best next-hop towards the passed originator and passes the
* skb on for preparation of MAC header. If the packet originated from this
* host, NULL can be passed as recv_if and no interface alternating is
* attempted.
*
* Return: -1 on failure (and the skb is not consumed), -EINPROGRESS if the
* skb is buffered for later transmit or the NET_XMIT status returned by the
* lower routine if the packet has been passed down.
*
* If the returning value is not -1 the skb has been consumed.
*/
int batadv_send_skb_to_orig(struct sk_buff *skb,
struct batadv_orig_node *orig_node,
struct batadv_hard_iface *recv_if)
{
struct batadv_priv *bat_priv = orig_node->bat_priv;
struct batadv_neigh_node *neigh_node;
int ret = -1;
/* batadv_find_router() increases neigh_nodes refcount if found. */
neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
if (!neigh_node)
goto out;
/* Check if the skb is too large to send in one piece and fragment
* it if needed.
*/
if (atomic_read(&bat_priv->fragmentation) &&
skb->len > neigh_node->if_incoming->net_dev->mtu) {
/* Fragment and send packet. */
ret = batadv_frag_send_packet(skb, orig_node, neigh_node);
goto out;
}
/* try to network code the packet, if it is received on an interface
* (i.e. being forwarded). If the packet originates from this node or if
* network coding fails, then send the packet as usual.
*/
if (recv_if && batadv_nc_skb_forward(skb, neigh_node))
ret = -EINPROGRESS;
else
ret = batadv_send_unicast_skb(skb, neigh_node);
out:
if (neigh_node)
batadv_neigh_node_put(neigh_node);
return ret;
}
/**
* batadv_send_skb_push_fill_unicast - extend the buffer and initialize the
* common fields for unicast packets
* @skb: the skb carrying the unicast header to initialize
* @hdr_size: amount of bytes to push at the beginning of the skb
* @orig_node: the destination node
*
* Return: false if the buffer extension was not possible or true otherwise.
*/
static bool
batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
struct batadv_orig_node *orig_node)
{
struct batadv_unicast_packet *unicast_packet;
u8 ttvn = (u8)atomic_read(&orig_node->last_ttvn);
if (batadv_skb_head_push(skb, hdr_size) < 0)
return false;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
unicast_packet->version = BATADV_COMPAT_VERSION;
/* batman packet type: unicast */
unicast_packet->packet_type = BATADV_UNICAST;
/* set unicast ttl */
unicast_packet->ttl = BATADV_TTL;
/* copy the destination for faster routing */
ether_addr_copy(unicast_packet->dest, orig_node->orig);
/* set the destination tt version number */
unicast_packet->ttvn = ttvn;
return true;
}
/**
* batadv_send_skb_prepare_unicast - encapsulate an skb with a unicast header
* @skb: the skb containing the payload to encapsulate
* @orig_node: the destination node
*
* Return: false if the payload could not be encapsulated or true otherwise.
*/
static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
struct batadv_orig_node *orig_node)
{
size_t uni_size = sizeof(struct batadv_unicast_packet);
return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
}
/**
* batadv_send_skb_prepare_unicast_4addr - encapsulate an skb with a
* unicast 4addr header
* @bat_priv: the bat priv with all the soft interface information
* @skb: the skb containing the payload to encapsulate
* @orig: the destination node
* @packet_subtype: the unicast 4addr packet subtype to use
*
* Return: false if the payload could not be encapsulated or true otherwise.
*/
bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
struct sk_buff *skb,
struct batadv_orig_node *orig,
int packet_subtype)
{
struct batadv_hard_iface *primary_if;
struct batadv_unicast_4addr_packet *uc_4addr_packet;
bool ret = false;
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
/* Pull the header space and fill the unicast_packet substructure.
* We can do that because the first member of the uc_4addr_packet
* is of type struct unicast_packet
*/
if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
orig))
goto out;
uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr);
uc_4addr_packet->subtype = packet_subtype;
uc_4addr_packet->reserved = 0;
ret = true;
out:
if (primary_if)
batadv_hardif_put(primary_if);
return ret;
}
/**
* batadv_send_skb_unicast - encapsulate and send an skb via unicast
* @bat_priv: the bat priv with all the soft interface information
* @skb: payload to send
* @packet_type: the batman unicast packet type to use
* @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
* 4addr packets)
* @orig_node: the originator to send the packet to
* @vid: the vid to be used to search the translation table
*
* Wrap the given skb into a batman-adv unicast or unicast-4addr header
* depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
* as packet_type. Then send this frame to the given orig_node.
*
* Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
*/
int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
struct sk_buff *skb, int packet_type,
int packet_subtype,
struct batadv_orig_node *orig_node,
unsigned short vid)
{
struct batadv_unicast_packet *unicast_packet;
struct ethhdr *ethhdr;
int res, ret = NET_XMIT_DROP;
if (!orig_node)
goto out;
switch (packet_type) {
case BATADV_UNICAST:
if (!batadv_send_skb_prepare_unicast(skb, orig_node))
goto out;
break;
case BATADV_UNICAST_4ADDR:
if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
orig_node,
packet_subtype))
goto out;
break;
default:
/* this function supports UNICAST and UNICAST_4ADDR only. It
* should never be invoked with any other packet type
*/
goto out;
}
/* skb->data might have been reallocated by
* batadv_send_skb_prepare_unicast{,_4addr}()
*/
ethhdr = eth_hdr(skb);
unicast_packet = (struct batadv_unicast_packet *)skb->data;
/* inform the destination node that we are still missing a correct route
* for this client. The destination will receive this packet and will
* try to reroute it because the ttvn contained in the header is less
* than the current one
*/
if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
unicast_packet->ttvn = unicast_packet->ttvn - 1;
res = batadv_send_skb_to_orig(skb, orig_node, NULL);
if (res != -1)
ret = NET_XMIT_SUCCESS;
out:
if (ret == NET_XMIT_DROP)
kfree_skb(skb);
return ret;
}
/**
* batadv_send_skb_via_tt_generic - send an skb via TT lookup
* @bat_priv: the bat priv with all the soft interface information
* @skb: payload to send
* @packet_type: the batman unicast packet type to use
* @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
* 4addr packets)
* @dst_hint: can be used to override the destination contained in the skb
* @vid: the vid to be used to search the translation table
*
* Look up the recipient node for the destination address in the ethernet
* header via the translation table. Wrap the given skb into a batman-adv
* unicast or unicast-4addr header depending on whether BATADV_UNICAST or
* BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
* to the according destination node.
*
* Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
*/
int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
struct sk_buff *skb, int packet_type,
int packet_subtype, u8 *dst_hint,
unsigned short vid)
{
struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
struct batadv_orig_node *orig_node;
u8 *src, *dst;
int ret;
src = ethhdr->h_source;
dst = ethhdr->h_dest;
/* if we got an hint! let's send the packet to this client (if any) */
if (dst_hint) {
src = NULL;
dst = dst_hint;
}
orig_node = batadv_transtable_search(bat_priv, src, dst, vid);
ret = batadv_send_skb_unicast(bat_priv, skb, packet_type,
packet_subtype, orig_node, vid);
if (orig_node)
batadv_orig_node_put(orig_node);
return ret;
}
/**
* batadv_send_skb_via_gw - send an skb via gateway lookup
* @bat_priv: the bat priv with all the soft interface information
* @skb: payload to send
* @vid: the vid to be used to search the translation table
*
* Look up the currently selected gateway. Wrap the given skb into a batman-adv
* unicast header and send this frame to this gateway node.
*
* Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
*/
int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
unsigned short vid)
{
struct batadv_orig_node *orig_node;
int ret;
orig_node = batadv_gw_get_selected_orig(bat_priv);
ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR,
BATADV_P_DATA, orig_node, vid);
if (orig_node)
batadv_orig_node_put(orig_node);
return ret;
}
/**
* batadv_forw_packet_free - free a forwarding packet
* @forw_packet: The packet to free
*
* This frees a forwarding packet and releases any resources it might
* have claimed.
*/
void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
{
kfree_skb(forw_packet->skb);
if (forw_packet->if_incoming)
batadv_hardif_put(forw_packet->if_incoming);
if (forw_packet->if_outgoing)
batadv_hardif_put(forw_packet->if_outgoing);
if (forw_packet->queue_left)
atomic_inc(forw_packet->queue_left);
kfree(forw_packet);
}
/**
* batadv_forw_packet_alloc - allocate a forwarding packet
* @if_incoming: The (optional) if_incoming to be grabbed
* @if_outgoing: The (optional) if_outgoing to be grabbed
* @queue_left: The (optional) queue counter to decrease
* @bat_priv: The bat_priv for the mesh of this forw_packet
*
* Allocates a forwarding packet and tries to get a reference to the
* (optional) if_incoming, if_outgoing and queue_left. If queue_left
* is NULL then bat_priv is optional, too.
*
* Return: An allocated forwarding packet on success, NULL otherwise.
*/
struct batadv_forw_packet *
batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming,
struct batadv_hard_iface *if_outgoing,
atomic_t *queue_left,
struct batadv_priv *bat_priv)
{
struct batadv_forw_packet *forw_packet;
const char *qname;
if (queue_left && !batadv_atomic_dec_not_zero(queue_left)) {
qname = "unknown";
if (queue_left == &bat_priv->bcast_queue_left)
qname = "bcast";
if (queue_left == &bat_priv->batman_queue_left)
qname = "batman";
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"%s queue is full\n", qname);
return NULL;
}
forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
if (!forw_packet)
goto err;
if (if_incoming)
kref_get(&if_incoming->refcount);
if (if_outgoing)
kref_get(&if_outgoing->refcount);
forw_packet->skb = NULL;
forw_packet->queue_left = queue_left;
forw_packet->if_incoming = if_incoming;
forw_packet->if_outgoing = if_outgoing;
forw_packet->num_packets = 0;
return forw_packet;
err:
if (queue_left)
atomic_inc(queue_left);
return NULL;
}
static void
_batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
struct batadv_forw_packet *forw_packet,
unsigned long send_time)
{
/* 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 */
queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work,
send_time);
}
/**
* batadv_add_bcast_packet_to_list - queue broadcast packet for multiple sends
* @bat_priv: the bat priv with all the soft interface information
* @skb: broadcast packet to add
* @delay: number of jiffies to wait before sending
*
* add a broadcast packet to the queue and setup timers. broadcast packets
* are sent multiple times to increase probability for being received.
*
* The skb is not consumed, so the caller should make sure that the
* skb is freed.
*
* Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
*/
int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
const struct sk_buff *skb,
unsigned long delay)
{
struct batadv_hard_iface *primary_if = NULL;
struct batadv_forw_packet *forw_packet;
struct batadv_bcast_packet *bcast_packet;
struct sk_buff *newskb;
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto err;
forw_packet = batadv_forw_packet_alloc(primary_if, NULL,
&bat_priv->bcast_queue_left,
bat_priv);
batadv_hardif_put(primary_if);
if (!forw_packet)
goto err;
newskb = skb_copy(skb, GFP_ATOMIC);
if (!newskb)
goto err_packet_free;
/* as we have a copy now, it is safe to decrease the TTL */
bcast_packet = (struct batadv_bcast_packet *)newskb->data;
bcast_packet->ttl--;
skb_reset_mac_header(newskb);
forw_packet->skb = newskb;
INIT_DELAYED_WORK(&forw_packet->delayed_work,
batadv_send_outstanding_bcast_packet);
_batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay);
return NETDEV_TX_OK;
err_packet_free:
batadv_forw_packet_free(forw_packet);
err:
return NETDEV_TX_BUSY;
}
static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
{
struct batadv_hard_iface *hard_iface;
struct delayed_work *delayed_work;
struct batadv_forw_packet *forw_packet;
struct sk_buff *skb1;
struct net_device *soft_iface;
struct batadv_priv *bat_priv;
delayed_work = to_delayed_work(work);
forw_packet = container_of(delayed_work, struct batadv_forw_packet,
delayed_work);
soft_iface = forw_packet->if_incoming->soft_iface;
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) == BATADV_MESH_DEACTIVATING)
goto out;
if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet))
goto out;
/* rebroadcast packet */
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
if (hard_iface->soft_iface != soft_iface)
continue;
if (forw_packet->num_packets >= hard_iface->num_bcasts)
continue;
if (!kref_get_unless_zero(&hard_iface->refcount))
continue;
/* send a copy of the saved skb */
skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
if (skb1)
batadv_send_broadcast_skb(skb1, hard_iface);
batadv_hardif_put(hard_iface);
}
rcu_read_unlock();
forw_packet->num_packets++;
/* if we still have some more bcasts to send */
if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) {
_batadv_add_bcast_packet_to_list(bat_priv, forw_packet,
msecs_to_jiffies(5));
return;
}
out:
batadv_forw_packet_free(forw_packet);
}
void
batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
const struct batadv_hard_iface *hard_iface)
{
struct batadv_forw_packet *forw_packet;
struct hlist_node *safe_tmp_node;
bool pending;
if (hard_iface)
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"purge_outstanding_packets(): %s\n",
hard_iface->net_dev->name);
else
batadv_dbg(BATADV_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, 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) &&
(forw_packet->if_outgoing != hard_iface))
continue;
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
/* batadv_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);
batadv_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, 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) &&
(forw_packet->if_outgoing != 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);
batadv_forw_packet_free(forw_packet);
}
}
spin_unlock_bh(&bat_priv->forw_bat_list_lock);
}
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