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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (C) B.A.T.M.A.N. contributors:
  *
  * Marek Lindner, Simon Wunderlich
  */
 
 #include "send.h"
 #include "main.h"
 
 #include <linux/atomic.h>
 #include <linux/bug.h>
 #include <linux/byteorder/generic.h>
 #include <linux/container_of.h>
 #include <linux/errno.h>
 #include <linux/etherdevice.h>
 #include <linux/gfp.h>
 #include <linux/if.h>
 #include <linux/if_ether.h>
 #include <linux/jiffies.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.
  *
  * Regardless of the return value, the skb is consumed.
  *
  * Return: A negative errno code is returned on a failure. A success does not
  * guarantee the frame will be transmitted as it may be dropped due
  * to congestion or traffic shaping.
  */
 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.
      */
     ret = dev_queue_xmit(skb);
     return net_xmit_eval(ret);
 send_skb_err:
     kfree_skb(skb);
     return NET_XMIT_DROP;
 }
 
 /**
  * batadv_send_broadcast_skb() - Send broadcast packet via hard interface
  * @skb: packet to be transmitted (with batadv header and no outer eth header)
  * @hard_iface: outgoing interface
  *
  * Return: A negative errno code is returned on a failure. A success does not
  * guarantee the frame will be transmitted as it may be dropped due
  * to congestion or traffic shaping.
  */
 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);
 }
 
 /**
  * batadv_send_unicast_skb() - Send unicast packet to neighbor
  * @skb: packet to be transmitted (with batadv header and no outer eth header)
  * @neigh: neighbor which is used as next hop to destination
  *
  * Return: A negative errno code is returned on a failure. A success does not
  * guarantee the frame will be transmitted as it may be dropped due
  * to congestion or traffic shaping.
  */
 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;
 
     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: negative errno code on a failure, -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.
  */
 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;
 
     /* batadv_find_router() increases neigh_nodes refcount if found. */
     neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
     if (!neigh_node) {
         ret = -EINVAL;
         goto free_skb;
     }
 
     /* 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);
         /* skb was consumed */
         skb = NULL;
 
         goto put_neigh_node;
     }
 
     /* 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);
 
     /* skb was consumed */
     skb = NULL;
 
 put_neigh_node:
     batadv_neigh_node_put(neigh_node);
 free_skb:
     kfree_skb(skb);
 
     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:
     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 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;
 
     ret = batadv_send_skb_to_orig(skb, orig_node, NULL);
      /* skb was consumed */
     skb = NULL;
 
 out:
     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);
 
     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);
 
     batadv_orig_node_put(orig_node);
 
     return ret;
 }
 
 /**
  * batadv_forw_packet_free() - free a forwarding packet
  * @forw_packet: The packet to free
  * @dropped: whether the packet is freed because is dropped
  *
  * This frees a forwarding packet and releases any resources it might
  * have claimed.
  */
 void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet,
                  bool dropped)
 {
     if (dropped)
         kfree_skb(forw_packet->skb);
     else
         consume_skb(forw_packet->skb);
 
     batadv_hardif_put(forw_packet->if_incoming);
     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
  * @skb: The raw packet this forwarding packet shall contain
  *
  * 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 sk_buff *skb)
 {
     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);
 
     INIT_HLIST_NODE(&forw_packet->list);
     INIT_HLIST_NODE(&forw_packet->cleanup_list);
     forw_packet->skb = skb;
     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;
 }
 
 /**
  * batadv_forw_packet_was_stolen() - check whether someone stole this packet
  * @forw_packet: the forwarding packet to check
  *
  * This function checks whether the given forwarding packet was claimed by
  * someone else for free().
  *
  * Return: True if someone stole it, false otherwise.
  */
 static bool
 batadv_forw_packet_was_stolen(struct batadv_forw_packet *forw_packet)
 {
     return !hlist_unhashed(&forw_packet->cleanup_list);
 }
 
 /**
  * batadv_forw_packet_steal() - claim a forw_packet for free()
  * @forw_packet: the forwarding packet to steal
  * @lock: a key to the store to steal from (e.g. forw_{bat,bcast}_list_lock)
  *
  * This function tries to steal a specific forw_packet from global
  * visibility for the purpose of getting it for free(). That means
  * the caller is *not* allowed to requeue it afterwards.
  *
  * Return: True if stealing was successful. False if someone else stole it
  * before us.
  */
 bool batadv_forw_packet_steal(struct batadv_forw_packet *forw_packet,
                   spinlock_t *lock)
 {
     /* did purging routine steal it earlier? */
     spin_lock_bh(lock);
     if (batadv_forw_packet_was_stolen(forw_packet)) {
         spin_unlock_bh(lock);
         return false;
     }
 
     hlist_del_init(&forw_packet->list);
 
     /* Just to spot misuse of this function */
     hlist_add_fake(&forw_packet->cleanup_list);
 
     spin_unlock_bh(lock);
     return true;
 }
 
 /**
  * batadv_forw_packet_list_steal() - claim a list of forward packets for free()
  * @forw_list: the to be stolen forward packets
  * @cleanup_list: a backup pointer, to be able to dispose the packet later
  * @hard_iface: the interface to steal forward packets from
  *
  * This function claims responsibility to free any forw_packet queued on the
  * given hard_iface. If hard_iface is NULL forwarding packets on all hard
  * interfaces will be claimed.
  *
  * The packets are being moved from the forw_list to the cleanup_list. This
  * makes it possible for already running threads to notice the claim.
  */
 static void
 batadv_forw_packet_list_steal(struct hlist_head *forw_list,
                   struct hlist_head *cleanup_list,
                   const struct batadv_hard_iface *hard_iface)
 {
     struct batadv_forw_packet *forw_packet;
     struct hlist_node *safe_tmp_node;
 
     hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
                   forw_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;
 
         hlist_del(&forw_packet->list);
         hlist_add_head(&forw_packet->cleanup_list, cleanup_list);
     }
 }
 
 /**
  * batadv_forw_packet_list_free() - free a list of forward packets
  * @head: a list of to be freed forw_packets
  *
  * This function cancels the scheduling of any packet in the provided list,
  * waits for any possibly running packet forwarding thread to finish and
  * finally, safely frees this forward packet.
  *
  * This function might sleep.
  */
 static void batadv_forw_packet_list_free(struct hlist_head *head)
 {
     struct batadv_forw_packet *forw_packet;
     struct hlist_node *safe_tmp_node;
 
     hlist_for_each_entry_safe(forw_packet, safe_tmp_node, head,
                   cleanup_list) {
         cancel_delayed_work_sync(&forw_packet->delayed_work);
 
         hlist_del(&forw_packet->cleanup_list);
         batadv_forw_packet_free(forw_packet, true);
     }
 }
 
 /**
  * batadv_forw_packet_queue() - try to queue a forwarding packet
  * @forw_packet: the forwarding packet to queue
  * @lock: a key to the store (e.g. forw_{bat,bcast}_list_lock)
  * @head: the shelve to queue it on (e.g. forw_{bat,bcast}_list)
  * @send_time: timestamp (jiffies) when the packet is to be sent
  *
  * This function tries to (re)queue a forwarding packet. Requeuing
  * is prevented if the according interface is shutting down
  * (e.g. if batadv_forw_packet_list_steal() was called for this
  * packet earlier).
  *
  * Calling batadv_forw_packet_queue() after a call to
  * batadv_forw_packet_steal() is forbidden!
  *
  * Caller needs to ensure that forw_packet->delayed_work was initialized.
  */
 static void batadv_forw_packet_queue(struct batadv_forw_packet *forw_packet,
                      spinlock_t *lock, struct hlist_head *head,
                      unsigned long send_time)
 {
     spin_lock_bh(lock);
 
     /* did purging routine steal it from us? */
     if (batadv_forw_packet_was_stolen(forw_packet)) {
         /* If you got it for free() without trouble, then
          * don't get back into the queue after stealing...
          */
         WARN_ONCE(hlist_fake(&forw_packet->cleanup_list),
               "Requeuing after batadv_forw_packet_steal() not allowed!\n");
 
         spin_unlock_bh(lock);
         return;
     }
 
     hlist_del_init(&forw_packet->list);
     hlist_add_head(&forw_packet->list, head);
 
     queue_delayed_work(batadv_event_workqueue,
                &forw_packet->delayed_work,
                send_time - jiffies);
     spin_unlock_bh(lock);
 }
 
 /**
  * batadv_forw_packet_bcast_queue() - try to queue a broadcast packet
  * @bat_priv: the bat priv with all the soft interface information
  * @forw_packet: the forwarding packet to queue
  * @send_time: timestamp (jiffies) when the packet is to be sent
  *
  * This function tries to (re)queue a broadcast packet.
  *
  * Caller needs to ensure that forw_packet->delayed_work was initialized.
  */
 static void
 batadv_forw_packet_bcast_queue(struct batadv_priv *bat_priv,
                    struct batadv_forw_packet *forw_packet,
                    unsigned long send_time)
 {
     batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bcast_list_lock,
                  &bat_priv->forw_bcast_list, send_time);
 }
 
 /**
  * batadv_forw_packet_ogmv1_queue() - try to queue an OGMv1 packet
  * @bat_priv: the bat priv with all the soft interface information
  * @forw_packet: the forwarding packet to queue
  * @send_time: timestamp (jiffies) when the packet is to be sent
  *
  * This function tries to (re)queue an OGMv1 packet.
  *
  * Caller needs to ensure that forw_packet->delayed_work was initialized.
  */
 void batadv_forw_packet_ogmv1_queue(struct batadv_priv *bat_priv,
                     struct batadv_forw_packet *forw_packet,
                     unsigned long send_time)
 {
     batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bat_list_lock,
                  &bat_priv->forw_bat_list, send_time);
 }
 
 /**
  * batadv_forw_bcast_packet_to_list() - queue broadcast packet for transmissions
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: broadcast packet to add
  * @delay: number of jiffies to wait before sending
  * @own_packet: true if it is a self-generated broadcast packet
  * @if_in: the interface where the packet was received on
  * @if_out: the outgoing interface to queue on
  *
  * Adds a broadcast packet to the queue and sets up timers. Broadcast packets
  * are sent multiple times to increase probability for being received.
  *
  * This call clones the given skb, hence the caller needs to take into
  * account that the data segment of the original skb might not be
  * modifiable anymore.
  *
  * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
  */
 static int batadv_forw_bcast_packet_to_list(struct batadv_priv *bat_priv,
                         struct sk_buff *skb,
                         unsigned long delay,
                         bool own_packet,
                         struct batadv_hard_iface *if_in,
                         struct batadv_hard_iface *if_out)
 {
     struct batadv_forw_packet *forw_packet;
     unsigned long send_time = jiffies;
     struct sk_buff *newskb;
 
     newskb = skb_clone(skb, GFP_ATOMIC);
     if (!newskb)
         goto err;
 
     forw_packet = batadv_forw_packet_alloc(if_in, if_out,
                            &bat_priv->bcast_queue_left,
                            bat_priv, newskb);
     if (!forw_packet)
         goto err_packet_free;
 
     forw_packet->own = own_packet;
 
     INIT_DELAYED_WORK(&forw_packet->delayed_work,
               batadv_send_outstanding_bcast_packet);
 
     send_time += delay ? delay : msecs_to_jiffies(5);
 
     batadv_forw_packet_bcast_queue(bat_priv, forw_packet, send_time);
     return NETDEV_TX_OK;
 
 err_packet_free:
     kfree_skb(newskb);
 err:
     return NETDEV_TX_BUSY;
 }
 
 /**
  * batadv_forw_bcast_packet_if() - forward and queue a broadcast packet
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: broadcast packet to add
  * @delay: number of jiffies to wait before sending
  * @own_packet: true if it is a self-generated broadcast packet
  * @if_in: the interface where the packet was received on
  * @if_out: the outgoing interface to forward to
  *
  * Transmits a broadcast packet on the specified interface either immediately
  * or if a delay is given after that. Furthermore, queues additional
  * retransmissions if this interface is a wireless one.
  *
  * This call clones the given skb, hence the caller needs to take into
  * account that the data segment of the original skb might not be
  * modifiable anymore.
  *
  * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
  */
 static int batadv_forw_bcast_packet_if(struct batadv_priv *bat_priv,
                        struct sk_buff *skb,
                        unsigned long delay,
                        bool own_packet,
                        struct batadv_hard_iface *if_in,
                        struct batadv_hard_iface *if_out)
 {
     unsigned int num_bcasts = if_out->num_bcasts;
     struct sk_buff *newskb;
     int ret = NETDEV_TX_OK;
 
     if (!delay) {
         newskb = skb_clone(skb, GFP_ATOMIC);
         if (!newskb)
             return NETDEV_TX_BUSY;
 
         batadv_send_broadcast_skb(newskb, if_out);
         num_bcasts--;
     }
 
     /* delayed broadcast or rebroadcasts? */
     if (num_bcasts >= 1) {
         BATADV_SKB_CB(skb)->num_bcasts = num_bcasts;
 
         ret = batadv_forw_bcast_packet_to_list(bat_priv, skb, delay,
                                own_packet, if_in,
                                if_out);
     }
 
     return ret;
 }
 
 /**
  * batadv_send_no_broadcast() - check whether (re)broadcast is necessary
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: broadcast packet to check
  * @own_packet: true if it is a self-generated broadcast packet
  * @if_out: the outgoing interface checked and considered for (re)broadcast
  *
  * Return: False if a packet needs to be (re)broadcasted on the given interface,
  * true otherwise.
  */
 static bool batadv_send_no_broadcast(struct batadv_priv *bat_priv,
                      struct sk_buff *skb, bool own_packet,
                      struct batadv_hard_iface *if_out)
 {
     struct batadv_hardif_neigh_node *neigh_node = NULL;
     struct batadv_bcast_packet *bcast_packet;
     u8 *orig_neigh;
     u8 *neigh_addr;
     char *type;
     int ret;
 
     if (!own_packet) {
         neigh_addr = eth_hdr(skb)->h_source;
         neigh_node = batadv_hardif_neigh_get(if_out,
                              neigh_addr);
     }
 
     bcast_packet = (struct batadv_bcast_packet *)skb->data;
     orig_neigh = neigh_node ? neigh_node->orig : NULL;
 
     ret = batadv_hardif_no_broadcast(if_out, bcast_packet->orig,
                      orig_neigh);
 
     batadv_hardif_neigh_put(neigh_node);
 
     /* ok, may broadcast */
     if (!ret)
         return false;
 
     /* no broadcast */
     switch (ret) {
     case BATADV_HARDIF_BCAST_NORECIPIENT:
         type = "no neighbor";
         break;
     case BATADV_HARDIF_BCAST_DUPFWD:
         type = "single neighbor is source";
         break;
     case BATADV_HARDIF_BCAST_DUPORIG:
         type = "single neighbor is originator";
         break;
     default:
         type = "unknown";
     }
 
     batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
            "BCAST packet from orig %pM on %s suppressed: %s\n",
            bcast_packet->orig,
            if_out->net_dev->name, type);
 
     return true;
 }
 
 /**
  * __batadv_forw_bcast_packet() - forward and queue a broadcast packet
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: broadcast packet to add
  * @delay: number of jiffies to wait before sending
  * @own_packet: true if it is a self-generated broadcast packet
  *
  * Transmits a broadcast packet either immediately or if a delay is given
  * after that. Furthermore, queues additional retransmissions on wireless
  * interfaces.
  *
  * This call clones the given skb, hence the caller needs to take into
  * account that the data segment of the given skb might not be
  * modifiable anymore.
  *
  * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
  */
 static int __batadv_forw_bcast_packet(struct batadv_priv *bat_priv,
                       struct sk_buff *skb,
                       unsigned long delay,
                       bool own_packet)
 {
     struct batadv_hard_iface *hard_iface;
     struct batadv_hard_iface *primary_if;
     int ret = NETDEV_TX_OK;
 
     primary_if = batadv_primary_if_get_selected(bat_priv);
     if (!primary_if)
         return NETDEV_TX_BUSY;
 
     rcu_read_lock();
     list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
         if (hard_iface->soft_iface != bat_priv->soft_iface)
             continue;
 
         if (!kref_get_unless_zero(&hard_iface->refcount))
             continue;
 
         if (batadv_send_no_broadcast(bat_priv, skb, own_packet,
                          hard_iface)) {
             batadv_hardif_put(hard_iface);
             continue;
         }
 
         ret = batadv_forw_bcast_packet_if(bat_priv, skb, delay,
                           own_packet, primary_if,
                           hard_iface);
         batadv_hardif_put(hard_iface);
 
         if (ret == NETDEV_TX_BUSY)
             break;
     }
     rcu_read_unlock();
 
     batadv_hardif_put(primary_if);
     return ret;
 }
 
 /**
  * batadv_forw_bcast_packet() - forward and queue a broadcast packet
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: broadcast packet to add
  * @delay: number of jiffies to wait before sending
  * @own_packet: true if it is a self-generated broadcast packet
  *
  * Transmits a broadcast packet either immediately or if a delay is given
  * after that. Furthermore, queues additional retransmissions on wireless
  * interfaces.
  *
  * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
  */
 int batadv_forw_bcast_packet(struct batadv_priv *bat_priv,
                  struct sk_buff *skb,
                  unsigned long delay,
                  bool own_packet)
 {
     return __batadv_forw_bcast_packet(bat_priv, skb, delay, own_packet);
 }
 
 /**
  * batadv_send_bcast_packet() - send and queue a broadcast packet
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: broadcast packet to add
  * @delay: number of jiffies to wait before sending
  * @own_packet: true if it is a self-generated broadcast packet
  *
  * Transmits a broadcast packet either immediately or if a delay is given
  * after that. Furthermore, queues additional retransmissions on wireless
  * interfaces.
  *
  * Consumes the provided skb.
  */
 void batadv_send_bcast_packet(struct batadv_priv *bat_priv,
                   struct sk_buff *skb,
                   unsigned long delay,
                   bool own_packet)
 {
     __batadv_forw_bcast_packet(bat_priv, skb, delay, own_packet);
     consume_skb(skb);
 }
 
 /**
  * batadv_forw_packet_bcasts_left() - check if a retransmission is necessary
  * @forw_packet: the forwarding packet to check
  *
  * Checks whether a given packet has any (re)transmissions left on the provided
  * interface.
  *
  * hard_iface may be NULL: In that case the number of transmissions this skb had
  * so far is compared with the maximum amount of retransmissions independent of
  * any interface instead.
  *
  * Return: True if (re)transmissions are left, false otherwise.
  */
 static bool
 batadv_forw_packet_bcasts_left(struct batadv_forw_packet *forw_packet)
 {
     return BATADV_SKB_CB(forw_packet->skb)->num_bcasts;
 }
 
 /**
  * batadv_forw_packet_bcasts_dec() - decrement retransmission counter of a
  *  packet
  * @forw_packet: the packet to decrease the counter for
  */
 static void
 batadv_forw_packet_bcasts_dec(struct batadv_forw_packet *forw_packet)
 {
     BATADV_SKB_CB(forw_packet->skb)->num_bcasts--;
 }
 
 /**
  * batadv_forw_packet_is_rebroadcast() - check packet for previous transmissions
  * @forw_packet: the packet to check
  *
  * Return: True if this packet was transmitted before, false otherwise.
  */
 bool batadv_forw_packet_is_rebroadcast(struct batadv_forw_packet *forw_packet)
 {
     unsigned char num_bcasts = BATADV_SKB_CB(forw_packet->skb)->num_bcasts;
 
     return num_bcasts != forw_packet->if_outgoing->num_bcasts;
 }
 
 /**
  * batadv_send_outstanding_bcast_packet() - transmit a queued broadcast packet
  * @work: work queue item
  *
  * Transmits a queued broadcast packet and if necessary reschedules it.
  */
 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 {
     unsigned long send_time = jiffies + msecs_to_jiffies(5);
     struct batadv_forw_packet *forw_packet;
     struct delayed_work *delayed_work;
     struct batadv_priv *bat_priv;
     struct sk_buff *skb1;
     bool dropped = false;
 
     delayed_work = to_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);
 
     if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
         dropped = true;
         goto out;
     }
 
     if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) {
         dropped = true;
         goto out;
     }
 
     /* send a copy of the saved skb */
     skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
     if (!skb1)
         goto out;
 
     batadv_send_broadcast_skb(skb1, forw_packet->if_outgoing);
     batadv_forw_packet_bcasts_dec(forw_packet);
 
     if (batadv_forw_packet_bcasts_left(forw_packet)) {
         batadv_forw_packet_bcast_queue(bat_priv, forw_packet,
                            send_time);
         return;
     }
 
 out:
     /* do we get something for free()? */
     if (batadv_forw_packet_steal(forw_packet,
                      &bat_priv->forw_bcast_list_lock))
         batadv_forw_packet_free(forw_packet, dropped);
 }
 
 /**
  * batadv_purge_outstanding_packets() - stop/purge scheduled bcast/OGMv1 packets
  * @bat_priv: the bat priv with all the soft interface information
  * @hard_iface: the hard interface to cancel and purge bcast/ogm packets on
  *
  * This method cancels and purges any broadcast and OGMv1 packet on the given
  * hard_iface. If hard_iface is NULL, broadcast and OGMv1 packets on all hard
  * interfaces will be canceled and purged.
  *
  * This function might sleep.
  */
 void
 batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
                  const struct batadv_hard_iface *hard_iface)
 {
     struct hlist_head head = HLIST_HEAD_INIT;
 
     if (hard_iface)
         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
                "%s(): %s\n",
                __func__, hard_iface->net_dev->name);
     else
         batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
                "%s()\n", __func__);
 
     /* claim bcast list for free() */
     spin_lock_bh(&bat_priv->forw_bcast_list_lock);
     batadv_forw_packet_list_steal(&bat_priv->forw_bcast_list, &head,
                       hard_iface);
     spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
 
     /* claim batman packet list for free() */
     spin_lock_bh(&bat_priv->forw_bat_list_lock);
     batadv_forw_packet_list_steal(&bat_priv->forw_bat_list, &head,
                       hard_iface);
     spin_unlock_bh(&bat_priv->forw_bat_list_lock);
 
     /* then cancel or wait for packet workers to finish and free */
     batadv_forw_packet_list_free(&head);
 }

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