- 根目录:
- net
- batman-adv
- send.c
/* Copyright (C) 2007-2014 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 "main.h"
#include "distributed-arp-table.h"
#include "send.h"
#include "routing.h"
#include "translation-table.h"
#include "soft-interface.h"
#include "hard-interface.h"
#include "gateway_common.h"
#include "gateway_client.h"
#include "originator.h"
#include "network-coding.h"
#include "fragmentation.h"
static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
/* send out an already prepared packet to the given address via the
* specified batman interface
*/
int batadv_send_skb_packet(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface,
const uint8_t *dst_addr)
{
struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
struct ethhdr *ethhdr;
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);
memcpy(ethhdr->h_source, hard_iface->net_dev->dev_addr, ETH_ALEN);
memcpy(ethhdr->h_dest, dst_addr, ETH_ALEN);
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.
*/
return dev_queue_xmit(skb);
send_skb_err:
kfree_skb(skb);
return NET_XMIT_DROP;
}
/**
* 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.
*
* Returns NET_XMIT_SUCCESS on success, NET_XMIT_DROP on failure, or
* NET_XMIT_POLICED if the skb is buffered for later transmit.
*/
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 = NET_XMIT_DROP;
/* 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. */
if (batadv_frag_send_packet(skb, orig_node, neigh_node))
ret = NET_XMIT_SUCCESS;
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 = NET_XMIT_POLICED;
} else {
batadv_send_skb_packet(skb, neigh_node->if_incoming,
neigh_node->addr);
ret = NET_XMIT_SUCCESS;
}
out:
if (neigh_node)
batadv_neigh_node_free_ref(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
*
* Returns 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;
uint8_t ttvn = (uint8_t)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 */
memcpy(unicast_packet->dest, orig_node->orig, ETH_ALEN);
/* 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
*
* Returns 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_node: the destination node
* @packet_subtype: the unicast 4addr packet subtype to use
*
* Returns 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;
memcpy(uc_4addr_packet->src, primary_if->net_dev->dev_addr, ETH_ALEN);
uc_4addr_packet->subtype = packet_subtype;
uc_4addr_packet->reserved = 0;
ret = true;
out:
if (primary_if)
batadv_hardif_free_ref(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 and release a
* reference to this orig_node.
*
* Returns NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
*/
static 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 ethhdr *ethhdr;
struct batadv_unicast_packet *unicast_packet;
int ret = NET_XMIT_DROP, hdr_size;
if (!orig_node)
goto out;
switch (packet_type) {
case BATADV_UNICAST:
if (!batadv_send_skb_prepare_unicast(skb, orig_node))
goto out;
hdr_size = sizeof(*unicast_packet);
break;
case BATADV_UNICAST_4ADDR:
if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
orig_node,
packet_subtype))
goto out;
hdr_size = sizeof(struct batadv_unicast_4addr_packet);
break;
default:
/* this function supports UNICAST and UNICAST_4ADDR only. It
* should never be invoked with any other packet type
*/
goto out;
}
ethhdr = (struct ethhdr *)(skb->data + hdr_size);
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;
if (batadv_send_skb_to_orig(skb, orig_node, NULL) != NET_XMIT_DROP)
ret = NET_XMIT_SUCCESS;
out:
if (orig_node)
batadv_orig_node_free_ref(orig_node);
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)
* @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.
*
* Returns 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, uint8_t *dst_hint,
unsigned short vid)
{
struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
struct batadv_orig_node *orig_node;
uint8_t *src, *dst;
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);
return batadv_send_skb_unicast(bat_priv, skb, packet_type,
packet_subtype, orig_node, vid);
}
/**
* 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.
*
* Returns 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;
orig_node = batadv_gw_get_selected_orig(bat_priv);
return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
orig_node, vid);
}
void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface)
{
struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
if ((hard_iface->if_status == BATADV_IF_NOT_IN_USE) ||
(hard_iface->if_status == BATADV_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 == BATADV_IF_TO_BE_ACTIVATED)
hard_iface->if_status = BATADV_IF_ACTIVE;
bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface);
}
static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet)
{
if (forw_packet->skb)
kfree_skb(forw_packet->skb);
if (forw_packet->if_incoming)
batadv_hardif_free_ref(forw_packet->if_incoming);
if (forw_packet->if_outgoing)
batadv_hardif_free_ref(forw_packet->if_outgoing);
kfree(forw_packet);
}
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);
}
/* 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 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;
if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) {
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"bcast packet queue full\n");
goto out;
}
primary_if = batadv_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 batadv_bcast_packet *)newskb->data;
bcast_packet->ttl--;
skb_reset_mac_header(newskb);
forw_packet->skb = newskb;
forw_packet->if_incoming = primary_if;
forw_packet->if_outgoing = NULL;
/* how often did we send the bcast packet ? */
forw_packet->num_packets = 0;
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;
packet_free:
kfree(forw_packet);
out_and_inc:
atomic_inc(&bat_priv->bcast_queue_left);
out:
if (primary_if)
batadv_hardif_free_ref(primary_if);
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 = container_of(work, struct 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;
/* send a copy of the saved skb */
skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
if (skb1)
batadv_send_skb_packet(skb1, hard_iface,
batadv_broadcast_addr);
}
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);
atomic_inc(&bat_priv->bcast_queue_left);
}
void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work)
{
struct delayed_work *delayed_work;
struct batadv_forw_packet *forw_packet;
struct batadv_priv *bat_priv;
delayed_work = container_of(work, struct delayed_work, work);
forw_packet = container_of(delayed_work, struct batadv_forw_packet,
delayed_work);
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) == BATADV_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.
*
* only re-schedule if this is the "original" copy, e.g. the OGM of the
* primary interface should only be rescheduled once per period, but
* this function will be called for the forw_packet instances of the
* other secondary interfaces as well.
*/
if (forw_packet->own &&
forw_packet->if_incoming == forw_packet->if_outgoing)
batadv_schedule_bat_ogm(forw_packet->if_incoming);
out:
/* don't count own packet */
if (!forw_packet->own)
atomic_inc(&bat_priv->batman_queue_left);
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))
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);
}