mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 10:32:35 +00:00
abac3ac97f
Syzkaller got a lot of crashes like:
KASAN: use-after-free Write in *_timers*
All of these crashes point to the same memory area:
The buggy address belongs to the object at ffff88801f870000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 5320 bytes inside of
8192-byte region [ffff88801f870000, ffff88801f872000)
This area belongs to :
batadv_priv->batadv_priv_dat->delayed_work->timer_list
The reason for these issues is the lack of synchronization. Delayed
work (batadv_dat_purge) schedules new timer/work while the device
is being deleted. As the result new timer/delayed work is set after
cancel_delayed_work_sync() was called. So after the device is freed
the timer list contains pointer to already freed memory.
Found by Linux Verification Center (linuxtesting.org) with syzkaller.
Cc: stable@kernel.org
Fixes: 2f1dfbe185
("batman-adv: Distributed ARP Table - implement local storage")
Signed-off-by: Vladislav Efanov <VEfanov@ispras.ru>
Acked-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
1832 lines
50 KiB
C
1832 lines
50 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (C) B.A.T.M.A.N. contributors:
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*
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* Antonio Quartulli
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*/
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#include "distributed-arp-table.h"
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#include "main.h"
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#include <asm/unaligned.h>
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#include <linux/atomic.h>
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#include <linux/bitops.h>
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#include <linux/byteorder/generic.h>
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#include <linux/container_of.h>
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#include <linux/errno.h>
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#include <linux/etherdevice.h>
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#include <linux/gfp.h>
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#include <linux/if_arp.h>
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#include <linux/if_ether.h>
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#include <linux/if_vlan.h>
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#include <linux/in.h>
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#include <linux/ip.h>
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#include <linux/jiffies.h>
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#include <linux/kref.h>
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#include <linux/list.h>
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#include <linux/netlink.h>
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#include <linux/rculist.h>
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#include <linux/rcupdate.h>
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#include <linux/skbuff.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/stddef.h>
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#include <linux/string.h>
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#include <linux/udp.h>
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#include <linux/workqueue.h>
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#include <net/arp.h>
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#include <net/genetlink.h>
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#include <net/netlink.h>
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#include <net/sock.h>
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#include <uapi/linux/batman_adv.h>
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#include "bridge_loop_avoidance.h"
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#include "hard-interface.h"
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#include "hash.h"
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#include "log.h"
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#include "netlink.h"
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#include "originator.h"
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#include "send.h"
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#include "soft-interface.h"
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#include "translation-table.h"
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#include "tvlv.h"
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enum batadv_bootpop {
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BATADV_BOOTREPLY = 2,
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};
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enum batadv_boothtype {
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BATADV_HTYPE_ETHERNET = 1,
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};
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enum batadv_dhcpoptioncode {
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BATADV_DHCP_OPT_PAD = 0,
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BATADV_DHCP_OPT_MSG_TYPE = 53,
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BATADV_DHCP_OPT_END = 255,
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};
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enum batadv_dhcptype {
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BATADV_DHCPACK = 5,
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};
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/* { 99, 130, 83, 99 } */
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#define BATADV_DHCP_MAGIC 1669485411
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struct batadv_dhcp_packet {
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__u8 op;
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__u8 htype;
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__u8 hlen;
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__u8 hops;
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__be32 xid;
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__be16 secs;
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__be16 flags;
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__be32 ciaddr;
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__be32 yiaddr;
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__be32 siaddr;
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__be32 giaddr;
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__u8 chaddr[16];
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__u8 sname[64];
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__u8 file[128];
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__be32 magic;
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/* __u8 options[]; */
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};
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#define BATADV_DHCP_YIADDR_LEN sizeof(((struct batadv_dhcp_packet *)0)->yiaddr)
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#define BATADV_DHCP_CHADDR_LEN sizeof(((struct batadv_dhcp_packet *)0)->chaddr)
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static void batadv_dat_purge(struct work_struct *work);
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/**
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* batadv_dat_start_timer() - initialise the DAT periodic worker
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* @bat_priv: the bat priv with all the soft interface information
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*/
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static void batadv_dat_start_timer(struct batadv_priv *bat_priv)
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{
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queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work,
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msecs_to_jiffies(10000));
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}
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/**
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* batadv_dat_entry_release() - release dat_entry from lists and queue for free
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* after rcu grace period
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* @ref: kref pointer of the dat_entry
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*/
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static void batadv_dat_entry_release(struct kref *ref)
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{
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struct batadv_dat_entry *dat_entry;
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dat_entry = container_of(ref, struct batadv_dat_entry, refcount);
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kfree_rcu(dat_entry, rcu);
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}
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/**
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* batadv_dat_entry_put() - decrement the dat_entry refcounter and possibly
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* release it
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* @dat_entry: dat_entry to be free'd
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*/
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static void batadv_dat_entry_put(struct batadv_dat_entry *dat_entry)
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{
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if (!dat_entry)
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return;
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kref_put(&dat_entry->refcount, batadv_dat_entry_release);
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}
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/**
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* batadv_dat_to_purge() - check whether a dat_entry has to be purged or not
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* @dat_entry: the entry to check
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*
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* Return: true if the entry has to be purged now, false otherwise.
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*/
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static bool batadv_dat_to_purge(struct batadv_dat_entry *dat_entry)
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{
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return batadv_has_timed_out(dat_entry->last_update,
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BATADV_DAT_ENTRY_TIMEOUT);
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}
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/**
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* __batadv_dat_purge() - delete entries from the DAT local storage
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* @bat_priv: the bat priv with all the soft interface information
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* @to_purge: function in charge to decide whether an entry has to be purged or
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* not. This function takes the dat_entry as argument and has to
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* returns a boolean value: true is the entry has to be deleted,
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* false otherwise
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*
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* Loops over each entry in the DAT local storage and deletes it if and only if
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* the to_purge function passed as argument returns true.
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*/
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static void __batadv_dat_purge(struct batadv_priv *bat_priv,
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bool (*to_purge)(struct batadv_dat_entry *))
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{
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spinlock_t *list_lock; /* protects write access to the hash lists */
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struct batadv_dat_entry *dat_entry;
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struct hlist_node *node_tmp;
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struct hlist_head *head;
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u32 i;
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if (!bat_priv->dat.hash)
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return;
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for (i = 0; i < bat_priv->dat.hash->size; i++) {
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head = &bat_priv->dat.hash->table[i];
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list_lock = &bat_priv->dat.hash->list_locks[i];
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spin_lock_bh(list_lock);
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hlist_for_each_entry_safe(dat_entry, node_tmp, head,
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hash_entry) {
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/* if a helper function has been passed as parameter,
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* ask it if the entry has to be purged or not
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*/
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if (to_purge && !to_purge(dat_entry))
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continue;
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hlist_del_rcu(&dat_entry->hash_entry);
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batadv_dat_entry_put(dat_entry);
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}
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spin_unlock_bh(list_lock);
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}
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}
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/**
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* batadv_dat_purge() - periodic task that deletes old entries from the local
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* DAT hash table
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* @work: kernel work struct
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*/
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static void batadv_dat_purge(struct work_struct *work)
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{
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struct delayed_work *delayed_work;
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struct batadv_priv_dat *priv_dat;
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struct batadv_priv *bat_priv;
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delayed_work = to_delayed_work(work);
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priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
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bat_priv = container_of(priv_dat, struct batadv_priv, dat);
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__batadv_dat_purge(bat_priv, batadv_dat_to_purge);
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batadv_dat_start_timer(bat_priv);
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}
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/**
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* batadv_compare_dat() - comparing function used in the local DAT hash table
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* @node: node in the local table
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* @data2: second object to compare the node to
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*
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* Return: true if the two entries are the same, false otherwise.
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*/
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static bool batadv_compare_dat(const struct hlist_node *node, const void *data2)
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{
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const void *data1 = container_of(node, struct batadv_dat_entry,
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hash_entry);
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return memcmp(data1, data2, sizeof(__be32)) == 0;
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}
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/**
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* batadv_arp_hw_src() - extract the hw_src field from an ARP packet
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* @skb: ARP packet
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* @hdr_size: size of the possible header before the ARP packet
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*
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* Return: the value of the hw_src field in the ARP packet.
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*/
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static u8 *batadv_arp_hw_src(struct sk_buff *skb, int hdr_size)
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{
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u8 *addr;
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addr = (u8 *)(skb->data + hdr_size);
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addr += ETH_HLEN + sizeof(struct arphdr);
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return addr;
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}
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/**
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* batadv_arp_ip_src() - extract the ip_src field from an ARP packet
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* @skb: ARP packet
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* @hdr_size: size of the possible header before the ARP packet
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*
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* Return: the value of the ip_src field in the ARP packet.
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*/
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static __be32 batadv_arp_ip_src(struct sk_buff *skb, int hdr_size)
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{
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return *(__force __be32 *)(batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN);
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}
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/**
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* batadv_arp_hw_dst() - extract the hw_dst field from an ARP packet
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* @skb: ARP packet
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* @hdr_size: size of the possible header before the ARP packet
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*
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* Return: the value of the hw_dst field in the ARP packet.
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*/
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static u8 *batadv_arp_hw_dst(struct sk_buff *skb, int hdr_size)
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{
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return batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN + 4;
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}
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/**
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* batadv_arp_ip_dst() - extract the ip_dst field from an ARP packet
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* @skb: ARP packet
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* @hdr_size: size of the possible header before the ARP packet
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*
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* Return: the value of the ip_dst field in the ARP packet.
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*/
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static __be32 batadv_arp_ip_dst(struct sk_buff *skb, int hdr_size)
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{
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u8 *dst = batadv_arp_hw_src(skb, hdr_size) + ETH_ALEN * 2 + 4;
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return *(__force __be32 *)dst;
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}
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/**
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* batadv_hash_dat() - compute the hash value for an IP address
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* @data: data to hash
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* @size: size of the hash table
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*
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* Return: the selected index in the hash table for the given data.
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*/
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static u32 batadv_hash_dat(const void *data, u32 size)
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{
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u32 hash = 0;
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const struct batadv_dat_entry *dat = data;
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const unsigned char *key;
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__be16 vid;
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u32 i;
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key = (__force const unsigned char *)&dat->ip;
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for (i = 0; i < sizeof(dat->ip); i++) {
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hash += key[i];
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hash += (hash << 10);
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hash ^= (hash >> 6);
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}
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vid = htons(dat->vid);
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key = (__force const unsigned char *)&vid;
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for (i = 0; i < sizeof(dat->vid); i++) {
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hash += key[i];
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hash += (hash << 10);
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hash ^= (hash >> 6);
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}
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hash += (hash << 3);
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hash ^= (hash >> 11);
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hash += (hash << 15);
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return hash % size;
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}
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/**
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* batadv_dat_entry_hash_find() - look for a given dat_entry in the local hash
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* table
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* @bat_priv: the bat priv with all the soft interface information
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* @ip: search key
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* @vid: VLAN identifier
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*
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* Return: the dat_entry if found, NULL otherwise.
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*/
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static struct batadv_dat_entry *
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batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip,
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unsigned short vid)
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{
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struct hlist_head *head;
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struct batadv_dat_entry to_find, *dat_entry, *dat_entry_tmp = NULL;
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struct batadv_hashtable *hash = bat_priv->dat.hash;
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u32 index;
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if (!hash)
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return NULL;
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to_find.ip = ip;
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to_find.vid = vid;
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index = batadv_hash_dat(&to_find, hash->size);
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head = &hash->table[index];
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rcu_read_lock();
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hlist_for_each_entry_rcu(dat_entry, head, hash_entry) {
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if (dat_entry->ip != ip)
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continue;
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if (!kref_get_unless_zero(&dat_entry->refcount))
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continue;
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dat_entry_tmp = dat_entry;
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break;
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}
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rcu_read_unlock();
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return dat_entry_tmp;
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}
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/**
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* batadv_dat_entry_add() - add a new dat entry or update it if already exists
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* @bat_priv: the bat priv with all the soft interface information
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* @ip: ipv4 to add/edit
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* @mac_addr: mac address to assign to the given ipv4
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* @vid: VLAN identifier
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*/
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static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip,
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u8 *mac_addr, unsigned short vid)
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{
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struct batadv_dat_entry *dat_entry;
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int hash_added;
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dat_entry = batadv_dat_entry_hash_find(bat_priv, ip, vid);
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/* if this entry is already known, just update it */
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if (dat_entry) {
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if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr))
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ether_addr_copy(dat_entry->mac_addr, mac_addr);
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dat_entry->last_update = jiffies;
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batadv_dbg(BATADV_DBG_DAT, bat_priv,
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"Entry updated: %pI4 %pM (vid: %d)\n",
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&dat_entry->ip, dat_entry->mac_addr,
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batadv_print_vid(vid));
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goto out;
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}
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dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC);
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if (!dat_entry)
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goto out;
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dat_entry->ip = ip;
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dat_entry->vid = vid;
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ether_addr_copy(dat_entry->mac_addr, mac_addr);
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dat_entry->last_update = jiffies;
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kref_init(&dat_entry->refcount);
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kref_get(&dat_entry->refcount);
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hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat,
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batadv_hash_dat, dat_entry,
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&dat_entry->hash_entry);
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if (unlikely(hash_added != 0)) {
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/* remove the reference for the hash */
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batadv_dat_entry_put(dat_entry);
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goto out;
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}
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batadv_dbg(BATADV_DBG_DAT, bat_priv, "New entry added: %pI4 %pM (vid: %d)\n",
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&dat_entry->ip, dat_entry->mac_addr, batadv_print_vid(vid));
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out:
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batadv_dat_entry_put(dat_entry);
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}
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#ifdef CONFIG_BATMAN_ADV_DEBUG
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/**
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* batadv_dbg_arp() - print a debug message containing all the ARP packet
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* details
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* @bat_priv: the bat priv with all the soft interface information
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* @skb: ARP packet
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* @hdr_size: size of the possible header before the ARP packet
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* @msg: message to print together with the debugging information
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*/
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static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
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int hdr_size, char *msg)
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{
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struct batadv_unicast_4addr_packet *unicast_4addr_packet;
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struct batadv_bcast_packet *bcast_pkt;
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u8 *orig_addr;
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__be32 ip_src, ip_dst;
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if (msg)
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batadv_dbg(BATADV_DBG_DAT, bat_priv, "%s\n", msg);
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ip_src = batadv_arp_ip_src(skb, hdr_size);
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ip_dst = batadv_arp_ip_dst(skb, hdr_size);
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batadv_dbg(BATADV_DBG_DAT, bat_priv,
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"ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
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batadv_arp_hw_src(skb, hdr_size), &ip_src,
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batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
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if (hdr_size < sizeof(struct batadv_unicast_packet))
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return;
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unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
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switch (unicast_4addr_packet->u.packet_type) {
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case BATADV_UNICAST:
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batadv_dbg(BATADV_DBG_DAT, bat_priv,
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"* encapsulated within a UNICAST packet\n");
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break;
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case BATADV_UNICAST_4ADDR:
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batadv_dbg(BATADV_DBG_DAT, bat_priv,
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"* encapsulated within a UNICAST_4ADDR packet (src: %pM)\n",
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unicast_4addr_packet->src);
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switch (unicast_4addr_packet->subtype) {
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case BATADV_P_DAT_DHT_PUT:
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batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_PUT\n");
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break;
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case BATADV_P_DAT_DHT_GET:
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batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DAT_DHT_GET\n");
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break;
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case BATADV_P_DAT_CACHE_REPLY:
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batadv_dbg(BATADV_DBG_DAT, bat_priv,
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"* type: DAT_CACHE_REPLY\n");
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break;
|
|
case BATADV_P_DATA:
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: DATA\n");
|
|
break;
|
|
default:
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv, "* type: Unknown (%u)!\n",
|
|
unicast_4addr_packet->u.packet_type);
|
|
}
|
|
break;
|
|
case BATADV_BCAST:
|
|
bcast_pkt = (struct batadv_bcast_packet *)unicast_4addr_packet;
|
|
orig_addr = bcast_pkt->orig;
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
|
"* encapsulated within a BCAST packet (src: %pM)\n",
|
|
orig_addr);
|
|
break;
|
|
default:
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
|
"* encapsulated within an unknown packet type (0x%x)\n",
|
|
unicast_4addr_packet->u.packet_type);
|
|
}
|
|
}
|
|
|
|
#else
|
|
|
|
static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
|
|
int hdr_size, char *msg)
|
|
{
|
|
}
|
|
|
|
#endif /* CONFIG_BATMAN_ADV_DEBUG */
|
|
|
|
/**
|
|
* batadv_is_orig_node_eligible() - check whether a node can be a DHT candidate
|
|
* @res: the array with the already selected candidates
|
|
* @select: number of already selected candidates
|
|
* @tmp_max: address of the currently evaluated node
|
|
* @max: current round max address
|
|
* @last_max: address of the last selected candidate
|
|
* @candidate: orig_node under evaluation
|
|
* @max_orig_node: last selected candidate
|
|
*
|
|
* Return: true if the node has been elected as next candidate or false
|
|
* otherwise.
|
|
*/
|
|
static bool batadv_is_orig_node_eligible(struct batadv_dat_candidate *res,
|
|
int select, batadv_dat_addr_t tmp_max,
|
|
batadv_dat_addr_t max,
|
|
batadv_dat_addr_t last_max,
|
|
struct batadv_orig_node *candidate,
|
|
struct batadv_orig_node *max_orig_node)
|
|
{
|
|
bool ret = false;
|
|
int j;
|
|
|
|
/* check if orig node candidate is running DAT */
|
|
if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities))
|
|
goto out;
|
|
|
|
/* Check if this node has already been selected... */
|
|
for (j = 0; j < select; j++)
|
|
if (res[j].orig_node == candidate)
|
|
break;
|
|
/* ..and possibly skip it */
|
|
if (j < select)
|
|
goto out;
|
|
/* sanity check: has it already been selected? This should not happen */
|
|
if (tmp_max > last_max)
|
|
goto out;
|
|
/* check if during this iteration an originator with a closer dht
|
|
* address has already been found
|
|
*/
|
|
if (tmp_max < max)
|
|
goto out;
|
|
/* this is an hash collision with the temporary selected node. Choose
|
|
* the one with the lowest address
|
|
*/
|
|
if (tmp_max == max && max_orig_node &&
|
|
batadv_compare_eth(candidate->orig, max_orig_node->orig))
|
|
goto out;
|
|
|
|
ret = true;
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* batadv_choose_next_candidate() - select the next DHT candidate
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @cands: candidates array
|
|
* @select: number of candidates already present in the array
|
|
* @ip_key: key to look up in the DHT
|
|
* @last_max: pointer where the address of the selected candidate will be saved
|
|
*/
|
|
static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
|
|
struct batadv_dat_candidate *cands,
|
|
int select, batadv_dat_addr_t ip_key,
|
|
batadv_dat_addr_t *last_max)
|
|
{
|
|
batadv_dat_addr_t max = 0;
|
|
batadv_dat_addr_t tmp_max = 0;
|
|
struct batadv_orig_node *orig_node, *max_orig_node = NULL;
|
|
struct batadv_hashtable *hash = bat_priv->orig_hash;
|
|
struct hlist_head *head;
|
|
int i;
|
|
|
|
/* if no node is eligible as candidate, leave the candidate type as
|
|
* NOT_FOUND
|
|
*/
|
|
cands[select].type = BATADV_DAT_CANDIDATE_NOT_FOUND;
|
|
|
|
/* iterate over the originator list and find the node with the closest
|
|
* dat_address which has not been selected yet
|
|
*/
|
|
for (i = 0; i < hash->size; i++) {
|
|
head = &hash->table[i];
|
|
|
|
rcu_read_lock();
|
|
hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
|
|
/* the dht space is a ring using unsigned addresses */
|
|
tmp_max = BATADV_DAT_ADDR_MAX - orig_node->dat_addr +
|
|
ip_key;
|
|
|
|
if (!batadv_is_orig_node_eligible(cands, select,
|
|
tmp_max, max,
|
|
*last_max, orig_node,
|
|
max_orig_node))
|
|
continue;
|
|
|
|
if (!kref_get_unless_zero(&orig_node->refcount))
|
|
continue;
|
|
|
|
max = tmp_max;
|
|
batadv_orig_node_put(max_orig_node);
|
|
max_orig_node = orig_node;
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
if (max_orig_node) {
|
|
cands[select].type = BATADV_DAT_CANDIDATE_ORIG;
|
|
cands[select].orig_node = max_orig_node;
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
|
"dat_select_candidates() %d: selected %pM addr=%u dist=%u\n",
|
|
select, max_orig_node->orig, max_orig_node->dat_addr,
|
|
max);
|
|
}
|
|
*last_max = max;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_select_candidates() - select the nodes which the DHT message has
|
|
* to be sent to
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @ip_dst: ipv4 to look up in the DHT
|
|
* @vid: VLAN identifier
|
|
*
|
|
* An originator O is selected if and only if its DHT_ID value is one of three
|
|
* closest values (from the LEFT, with wrap around if needed) then the hash
|
|
* value of the key. ip_dst is the key.
|
|
*
|
|
* Return: the candidate array of size BATADV_DAT_CANDIDATE_NUM.
|
|
*/
|
|
static struct batadv_dat_candidate *
|
|
batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst,
|
|
unsigned short vid)
|
|
{
|
|
int select;
|
|
batadv_dat_addr_t last_max = BATADV_DAT_ADDR_MAX, ip_key;
|
|
struct batadv_dat_candidate *res;
|
|
struct batadv_dat_entry dat;
|
|
|
|
if (!bat_priv->orig_hash)
|
|
return NULL;
|
|
|
|
res = kmalloc_array(BATADV_DAT_CANDIDATES_NUM, sizeof(*res),
|
|
GFP_ATOMIC);
|
|
if (!res)
|
|
return NULL;
|
|
|
|
dat.ip = ip_dst;
|
|
dat.vid = vid;
|
|
ip_key = (batadv_dat_addr_t)batadv_hash_dat(&dat,
|
|
BATADV_DAT_ADDR_MAX);
|
|
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
|
"%s(): IP=%pI4 hash(IP)=%u\n", __func__, &ip_dst,
|
|
ip_key);
|
|
|
|
for (select = 0; select < BATADV_DAT_CANDIDATES_NUM; select++)
|
|
batadv_choose_next_candidate(bat_priv, res, select, ip_key,
|
|
&last_max);
|
|
|
|
return res;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_forward_data() - copy and send payload to the selected candidates
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @skb: payload to send
|
|
* @ip: the DHT key
|
|
* @vid: VLAN identifier
|
|
* @packet_subtype: unicast4addr packet subtype to use
|
|
*
|
|
* This function copies the skb with pskb_copy() and is sent as a unicast packet
|
|
* to each of the selected candidates.
|
|
*
|
|
* Return: true if the packet is sent to at least one candidate, false
|
|
* otherwise.
|
|
*/
|
|
static bool batadv_dat_forward_data(struct batadv_priv *bat_priv,
|
|
struct sk_buff *skb, __be32 ip,
|
|
unsigned short vid, int packet_subtype)
|
|
{
|
|
int i;
|
|
bool ret = false;
|
|
int send_status;
|
|
struct batadv_neigh_node *neigh_node = NULL;
|
|
struct sk_buff *tmp_skb;
|
|
struct batadv_dat_candidate *cand;
|
|
|
|
cand = batadv_dat_select_candidates(bat_priv, ip, vid);
|
|
if (!cand)
|
|
goto out;
|
|
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv, "DHT_SEND for %pI4\n", &ip);
|
|
|
|
for (i = 0; i < BATADV_DAT_CANDIDATES_NUM; i++) {
|
|
if (cand[i].type == BATADV_DAT_CANDIDATE_NOT_FOUND)
|
|
continue;
|
|
|
|
neigh_node = batadv_orig_router_get(cand[i].orig_node,
|
|
BATADV_IF_DEFAULT);
|
|
if (!neigh_node)
|
|
goto free_orig;
|
|
|
|
tmp_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
|
|
if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, tmp_skb,
|
|
cand[i].orig_node,
|
|
packet_subtype)) {
|
|
kfree_skb(tmp_skb);
|
|
goto free_neigh;
|
|
}
|
|
|
|
send_status = batadv_send_unicast_skb(tmp_skb, neigh_node);
|
|
if (send_status == NET_XMIT_SUCCESS) {
|
|
/* count the sent packet */
|
|
switch (packet_subtype) {
|
|
case BATADV_P_DAT_DHT_GET:
|
|
batadv_inc_counter(bat_priv,
|
|
BATADV_CNT_DAT_GET_TX);
|
|
break;
|
|
case BATADV_P_DAT_DHT_PUT:
|
|
batadv_inc_counter(bat_priv,
|
|
BATADV_CNT_DAT_PUT_TX);
|
|
break;
|
|
}
|
|
|
|
/* packet sent to a candidate: return true */
|
|
ret = true;
|
|
}
|
|
free_neigh:
|
|
batadv_neigh_node_put(neigh_node);
|
|
free_orig:
|
|
batadv_orig_node_put(cand[i].orig_node);
|
|
}
|
|
|
|
out:
|
|
kfree(cand);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_tvlv_container_update() - update the dat tvlv container after dat
|
|
* setting change
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
*/
|
|
static void batadv_dat_tvlv_container_update(struct batadv_priv *bat_priv)
|
|
{
|
|
char dat_mode;
|
|
|
|
dat_mode = atomic_read(&bat_priv->distributed_arp_table);
|
|
|
|
switch (dat_mode) {
|
|
case 0:
|
|
batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
|
|
break;
|
|
case 1:
|
|
batadv_tvlv_container_register(bat_priv, BATADV_TVLV_DAT, 1,
|
|
NULL, 0);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_status_update() - update the dat tvlv container after dat
|
|
* setting change
|
|
* @net_dev: the soft interface net device
|
|
*/
|
|
void batadv_dat_status_update(struct net_device *net_dev)
|
|
{
|
|
struct batadv_priv *bat_priv = netdev_priv(net_dev);
|
|
|
|
batadv_dat_tvlv_container_update(bat_priv);
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_tvlv_ogm_handler_v1() - process incoming dat tvlv container
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @orig: the orig_node of the ogm
|
|
* @flags: flags indicating the tvlv state (see batadv_tvlv_handler_flags)
|
|
* @tvlv_value: tvlv buffer containing the gateway data
|
|
* @tvlv_value_len: tvlv buffer length
|
|
*/
|
|
static void batadv_dat_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
|
|
struct batadv_orig_node *orig,
|
|
u8 flags,
|
|
void *tvlv_value, u16 tvlv_value_len)
|
|
{
|
|
if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
|
|
clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
|
|
else
|
|
set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_hash_free() - free the local DAT hash table
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
*/
|
|
static void batadv_dat_hash_free(struct batadv_priv *bat_priv)
|
|
{
|
|
if (!bat_priv->dat.hash)
|
|
return;
|
|
|
|
__batadv_dat_purge(bat_priv, NULL);
|
|
|
|
batadv_hash_destroy(bat_priv->dat.hash);
|
|
|
|
bat_priv->dat.hash = NULL;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_init() - initialise the DAT internals
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
*
|
|
* Return: 0 in case of success, a negative error code otherwise
|
|
*/
|
|
int batadv_dat_init(struct batadv_priv *bat_priv)
|
|
{
|
|
if (bat_priv->dat.hash)
|
|
return 0;
|
|
|
|
bat_priv->dat.hash = batadv_hash_new(1024);
|
|
|
|
if (!bat_priv->dat.hash)
|
|
return -ENOMEM;
|
|
|
|
INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge);
|
|
batadv_dat_start_timer(bat_priv);
|
|
|
|
batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1,
|
|
NULL, NULL, BATADV_TVLV_DAT, 1,
|
|
BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
|
|
batadv_dat_tvlv_container_update(bat_priv);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_free() - free the DAT internals
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
*/
|
|
void batadv_dat_free(struct batadv_priv *bat_priv)
|
|
{
|
|
batadv_tvlv_container_unregister(bat_priv, BATADV_TVLV_DAT, 1);
|
|
batadv_tvlv_handler_unregister(bat_priv, BATADV_TVLV_DAT, 1);
|
|
|
|
cancel_delayed_work_sync(&bat_priv->dat.work);
|
|
|
|
batadv_dat_hash_free(bat_priv);
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_cache_dump_entry() - dump one entry of the DAT cache table to a
|
|
* netlink socket
|
|
* @msg: buffer for the message
|
|
* @portid: netlink port
|
|
* @cb: Control block containing additional options
|
|
* @dat_entry: entry to dump
|
|
*
|
|
* Return: 0 or error code.
|
|
*/
|
|
static int
|
|
batadv_dat_cache_dump_entry(struct sk_buff *msg, u32 portid,
|
|
struct netlink_callback *cb,
|
|
struct batadv_dat_entry *dat_entry)
|
|
{
|
|
int msecs;
|
|
void *hdr;
|
|
|
|
hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq,
|
|
&batadv_netlink_family, NLM_F_MULTI,
|
|
BATADV_CMD_GET_DAT_CACHE);
|
|
if (!hdr)
|
|
return -ENOBUFS;
|
|
|
|
genl_dump_check_consistent(cb, hdr);
|
|
|
|
msecs = jiffies_to_msecs(jiffies - dat_entry->last_update);
|
|
|
|
if (nla_put_in_addr(msg, BATADV_ATTR_DAT_CACHE_IP4ADDRESS,
|
|
dat_entry->ip) ||
|
|
nla_put(msg, BATADV_ATTR_DAT_CACHE_HWADDRESS, ETH_ALEN,
|
|
dat_entry->mac_addr) ||
|
|
nla_put_u16(msg, BATADV_ATTR_DAT_CACHE_VID, dat_entry->vid) ||
|
|
nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS, msecs)) {
|
|
genlmsg_cancel(msg, hdr);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
genlmsg_end(msg, hdr);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_cache_dump_bucket() - dump one bucket of the DAT cache table to
|
|
* a netlink socket
|
|
* @msg: buffer for the message
|
|
* @portid: netlink port
|
|
* @cb: Control block containing additional options
|
|
* @hash: hash to dump
|
|
* @bucket: bucket index to dump
|
|
* @idx_skip: How many entries to skip
|
|
*
|
|
* Return: 0 or error code.
|
|
*/
|
|
static int
|
|
batadv_dat_cache_dump_bucket(struct sk_buff *msg, u32 portid,
|
|
struct netlink_callback *cb,
|
|
struct batadv_hashtable *hash, unsigned int bucket,
|
|
int *idx_skip)
|
|
{
|
|
struct batadv_dat_entry *dat_entry;
|
|
int idx = 0;
|
|
|
|
spin_lock_bh(&hash->list_locks[bucket]);
|
|
cb->seq = atomic_read(&hash->generation) << 1 | 1;
|
|
|
|
hlist_for_each_entry(dat_entry, &hash->table[bucket], hash_entry) {
|
|
if (idx < *idx_skip)
|
|
goto skip;
|
|
|
|
if (batadv_dat_cache_dump_entry(msg, portid, cb, dat_entry)) {
|
|
spin_unlock_bh(&hash->list_locks[bucket]);
|
|
*idx_skip = idx;
|
|
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
skip:
|
|
idx++;
|
|
}
|
|
spin_unlock_bh(&hash->list_locks[bucket]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_cache_dump() - dump DAT cache table to a netlink socket
|
|
* @msg: buffer for the message
|
|
* @cb: callback structure containing arguments
|
|
*
|
|
* Return: message length.
|
|
*/
|
|
int batadv_dat_cache_dump(struct sk_buff *msg, struct netlink_callback *cb)
|
|
{
|
|
struct batadv_hard_iface *primary_if = NULL;
|
|
int portid = NETLINK_CB(cb->skb).portid;
|
|
struct net *net = sock_net(cb->skb->sk);
|
|
struct net_device *soft_iface;
|
|
struct batadv_hashtable *hash;
|
|
struct batadv_priv *bat_priv;
|
|
int bucket = cb->args[0];
|
|
int idx = cb->args[1];
|
|
int ifindex;
|
|
int ret = 0;
|
|
|
|
ifindex = batadv_netlink_get_ifindex(cb->nlh,
|
|
BATADV_ATTR_MESH_IFINDEX);
|
|
if (!ifindex)
|
|
return -EINVAL;
|
|
|
|
soft_iface = dev_get_by_index(net, ifindex);
|
|
if (!soft_iface || !batadv_softif_is_valid(soft_iface)) {
|
|
ret = -ENODEV;
|
|
goto out;
|
|
}
|
|
|
|
bat_priv = netdev_priv(soft_iface);
|
|
hash = bat_priv->dat.hash;
|
|
|
|
primary_if = batadv_primary_if_get_selected(bat_priv);
|
|
if (!primary_if || primary_if->if_status != BATADV_IF_ACTIVE) {
|
|
ret = -ENOENT;
|
|
goto out;
|
|
}
|
|
|
|
while (bucket < hash->size) {
|
|
if (batadv_dat_cache_dump_bucket(msg, portid, cb, hash, bucket,
|
|
&idx))
|
|
break;
|
|
|
|
bucket++;
|
|
idx = 0;
|
|
}
|
|
|
|
cb->args[0] = bucket;
|
|
cb->args[1] = idx;
|
|
|
|
ret = msg->len;
|
|
|
|
out:
|
|
batadv_hardif_put(primary_if);
|
|
|
|
dev_put(soft_iface);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* batadv_arp_get_type() - parse an ARP packet and gets the type
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @skb: packet to analyse
|
|
* @hdr_size: size of the possible header before the ARP packet in the skb
|
|
*
|
|
* Return: the ARP type if the skb contains a valid ARP packet, 0 otherwise.
|
|
*/
|
|
static u16 batadv_arp_get_type(struct batadv_priv *bat_priv,
|
|
struct sk_buff *skb, int hdr_size)
|
|
{
|
|
struct arphdr *arphdr;
|
|
struct ethhdr *ethhdr;
|
|
__be32 ip_src, ip_dst;
|
|
u8 *hw_src, *hw_dst;
|
|
u16 type = 0;
|
|
|
|
/* pull the ethernet header */
|
|
if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
|
|
goto out;
|
|
|
|
ethhdr = (struct ethhdr *)(skb->data + hdr_size);
|
|
|
|
if (ethhdr->h_proto != htons(ETH_P_ARP))
|
|
goto out;
|
|
|
|
/* pull the ARP payload */
|
|
if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
|
|
arp_hdr_len(skb->dev))))
|
|
goto out;
|
|
|
|
arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
|
|
|
|
/* check whether the ARP packet carries a valid IP information */
|
|
if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
|
|
goto out;
|
|
|
|
if (arphdr->ar_pro != htons(ETH_P_IP))
|
|
goto out;
|
|
|
|
if (arphdr->ar_hln != ETH_ALEN)
|
|
goto out;
|
|
|
|
if (arphdr->ar_pln != 4)
|
|
goto out;
|
|
|
|
/* Check for bad reply/request. If the ARP message is not sane, DAT
|
|
* will simply ignore it
|
|
*/
|
|
ip_src = batadv_arp_ip_src(skb, hdr_size);
|
|
ip_dst = batadv_arp_ip_dst(skb, hdr_size);
|
|
if (ipv4_is_loopback(ip_src) || ipv4_is_multicast(ip_src) ||
|
|
ipv4_is_loopback(ip_dst) || ipv4_is_multicast(ip_dst) ||
|
|
ipv4_is_zeronet(ip_src) || ipv4_is_lbcast(ip_src) ||
|
|
ipv4_is_zeronet(ip_dst) || ipv4_is_lbcast(ip_dst))
|
|
goto out;
|
|
|
|
hw_src = batadv_arp_hw_src(skb, hdr_size);
|
|
if (is_zero_ether_addr(hw_src) || is_multicast_ether_addr(hw_src))
|
|
goto out;
|
|
|
|
/* don't care about the destination MAC address in ARP requests */
|
|
if (arphdr->ar_op != htons(ARPOP_REQUEST)) {
|
|
hw_dst = batadv_arp_hw_dst(skb, hdr_size);
|
|
if (is_zero_ether_addr(hw_dst) ||
|
|
is_multicast_ether_addr(hw_dst))
|
|
goto out;
|
|
}
|
|
|
|
type = ntohs(arphdr->ar_op);
|
|
out:
|
|
return type;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_get_vid() - extract the VLAN identifier from skb if any
|
|
* @skb: the buffer containing the packet to extract the VID from
|
|
* @hdr_size: the size of the batman-adv header encapsulating the packet
|
|
*
|
|
* Return: If the packet embedded in the skb is vlan tagged this function
|
|
* returns the VID with the BATADV_VLAN_HAS_TAG flag. Otherwise BATADV_NO_FLAGS
|
|
* is returned.
|
|
*/
|
|
static unsigned short batadv_dat_get_vid(struct sk_buff *skb, int *hdr_size)
|
|
{
|
|
unsigned short vid;
|
|
|
|
vid = batadv_get_vid(skb, *hdr_size);
|
|
|
|
/* ARP parsing functions jump forward of hdr_size + ETH_HLEN.
|
|
* If the header contained in the packet is a VLAN one (which is longer)
|
|
* hdr_size is updated so that the functions will still skip the
|
|
* correct amount of bytes.
|
|
*/
|
|
if (vid & BATADV_VLAN_HAS_TAG)
|
|
*hdr_size += VLAN_HLEN;
|
|
|
|
return vid;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_arp_create_reply() - create an ARP Reply
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @ip_src: ARP sender IP
|
|
* @ip_dst: ARP target IP
|
|
* @hw_src: Ethernet source and ARP sender MAC
|
|
* @hw_dst: Ethernet destination and ARP target MAC
|
|
* @vid: VLAN identifier (optional, set to zero otherwise)
|
|
*
|
|
* Creates an ARP Reply from the given values, optionally encapsulated in a
|
|
* VLAN header.
|
|
*
|
|
* Return: An skb containing an ARP Reply.
|
|
*/
|
|
static struct sk_buff *
|
|
batadv_dat_arp_create_reply(struct batadv_priv *bat_priv, __be32 ip_src,
|
|
__be32 ip_dst, u8 *hw_src, u8 *hw_dst,
|
|
unsigned short vid)
|
|
{
|
|
struct sk_buff *skb;
|
|
|
|
skb = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_dst, bat_priv->soft_iface,
|
|
ip_src, hw_dst, hw_src, hw_dst);
|
|
if (!skb)
|
|
return NULL;
|
|
|
|
skb_reset_mac_header(skb);
|
|
|
|
if (vid & BATADV_VLAN_HAS_TAG)
|
|
skb = vlan_insert_tag(skb, htons(ETH_P_8021Q),
|
|
vid & VLAN_VID_MASK);
|
|
|
|
return skb;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_snoop_outgoing_arp_request() - snoop the ARP request and try to
|
|
* answer using DAT
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @skb: packet to check
|
|
*
|
|
* Return: true if the message has been sent to the dht candidates, false
|
|
* otherwise. In case of a positive return value the message has to be enqueued
|
|
* to permit the fallback.
|
|
*/
|
|
bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv,
|
|
struct sk_buff *skb)
|
|
{
|
|
u16 type = 0;
|
|
__be32 ip_dst, ip_src;
|
|
u8 *hw_src;
|
|
bool ret = false;
|
|
struct batadv_dat_entry *dat_entry = NULL;
|
|
struct sk_buff *skb_new;
|
|
struct net_device *soft_iface = bat_priv->soft_iface;
|
|
int hdr_size = 0;
|
|
unsigned short vid;
|
|
|
|
if (!atomic_read(&bat_priv->distributed_arp_table))
|
|
goto out;
|
|
|
|
vid = batadv_dat_get_vid(skb, &hdr_size);
|
|
|
|
type = batadv_arp_get_type(bat_priv, skb, hdr_size);
|
|
/* If the node gets an ARP_REQUEST it has to send a DHT_GET unicast
|
|
* message to the selected DHT candidates
|
|
*/
|
|
if (type != ARPOP_REQUEST)
|
|
goto out;
|
|
|
|
batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing outgoing ARP REQUEST");
|
|
|
|
ip_src = batadv_arp_ip_src(skb, hdr_size);
|
|
hw_src = batadv_arp_hw_src(skb, hdr_size);
|
|
ip_dst = batadv_arp_ip_dst(skb, hdr_size);
|
|
|
|
batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
|
|
|
|
dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
|
|
if (dat_entry) {
|
|
/* If the ARP request is destined for a local client the local
|
|
* client will answer itself. DAT would only generate a
|
|
* duplicate packet.
|
|
*
|
|
* Moreover, if the soft-interface is enslaved into a bridge, an
|
|
* additional DAT answer may trigger kernel warnings about
|
|
* a packet coming from the wrong port.
|
|
*/
|
|
if (batadv_is_my_client(bat_priv, dat_entry->mac_addr, vid)) {
|
|
ret = true;
|
|
goto out;
|
|
}
|
|
|
|
/* If BLA is enabled, only send ARP replies if we have claimed
|
|
* the destination for the ARP request or if no one else of
|
|
* the backbone gws belonging to our backbone has claimed the
|
|
* destination.
|
|
*/
|
|
if (!batadv_bla_check_claim(bat_priv,
|
|
dat_entry->mac_addr, vid)) {
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
|
"Device %pM claimed by another backbone gw. Don't send ARP reply!",
|
|
dat_entry->mac_addr);
|
|
ret = true;
|
|
goto out;
|
|
}
|
|
|
|
skb_new = batadv_dat_arp_create_reply(bat_priv, ip_dst, ip_src,
|
|
dat_entry->mac_addr,
|
|
hw_src, vid);
|
|
if (!skb_new)
|
|
goto out;
|
|
|
|
skb_new->protocol = eth_type_trans(skb_new, soft_iface);
|
|
|
|
batadv_inc_counter(bat_priv, BATADV_CNT_RX);
|
|
batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
|
|
skb->len + ETH_HLEN + hdr_size);
|
|
|
|
netif_rx(skb_new);
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv, "ARP request replied locally\n");
|
|
ret = true;
|
|
} else {
|
|
/* Send the request to the DHT */
|
|
ret = batadv_dat_forward_data(bat_priv, skb, ip_dst, vid,
|
|
BATADV_P_DAT_DHT_GET);
|
|
}
|
|
out:
|
|
batadv_dat_entry_put(dat_entry);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_snoop_incoming_arp_request() - snoop the ARP request and try to
|
|
* answer using the local DAT storage
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @skb: packet to check
|
|
* @hdr_size: size of the encapsulation header
|
|
*
|
|
* Return: true if the request has been answered, false otherwise.
|
|
*/
|
|
bool batadv_dat_snoop_incoming_arp_request(struct batadv_priv *bat_priv,
|
|
struct sk_buff *skb, int hdr_size)
|
|
{
|
|
u16 type;
|
|
__be32 ip_src, ip_dst;
|
|
u8 *hw_src;
|
|
struct sk_buff *skb_new;
|
|
struct batadv_dat_entry *dat_entry = NULL;
|
|
bool ret = false;
|
|
unsigned short vid;
|
|
int err;
|
|
|
|
if (!atomic_read(&bat_priv->distributed_arp_table))
|
|
goto out;
|
|
|
|
vid = batadv_dat_get_vid(skb, &hdr_size);
|
|
|
|
type = batadv_arp_get_type(bat_priv, skb, hdr_size);
|
|
if (type != ARPOP_REQUEST)
|
|
goto out;
|
|
|
|
hw_src = batadv_arp_hw_src(skb, hdr_size);
|
|
ip_src = batadv_arp_ip_src(skb, hdr_size);
|
|
ip_dst = batadv_arp_ip_dst(skb, hdr_size);
|
|
|
|
batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing incoming ARP REQUEST");
|
|
|
|
batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
|
|
|
|
dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
|
|
if (!dat_entry)
|
|
goto out;
|
|
|
|
skb_new = batadv_dat_arp_create_reply(bat_priv, ip_dst, ip_src,
|
|
dat_entry->mac_addr, hw_src, vid);
|
|
if (!skb_new)
|
|
goto out;
|
|
|
|
/* To preserve backwards compatibility, the node has choose the outgoing
|
|
* format based on the incoming request packet type. The assumption is
|
|
* that a node not using the 4addr packet format doesn't support it.
|
|
*/
|
|
if (hdr_size == sizeof(struct batadv_unicast_4addr_packet))
|
|
err = batadv_send_skb_via_tt_4addr(bat_priv, skb_new,
|
|
BATADV_P_DAT_CACHE_REPLY,
|
|
NULL, vid);
|
|
else
|
|
err = batadv_send_skb_via_tt(bat_priv, skb_new, NULL, vid);
|
|
|
|
if (err != NET_XMIT_DROP) {
|
|
batadv_inc_counter(bat_priv, BATADV_CNT_DAT_CACHED_REPLY_TX);
|
|
ret = true;
|
|
}
|
|
out:
|
|
batadv_dat_entry_put(dat_entry);
|
|
if (ret)
|
|
kfree_skb(skb);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_snoop_outgoing_arp_reply() - snoop the ARP reply and fill the DHT
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @skb: packet to check
|
|
*/
|
|
void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv,
|
|
struct sk_buff *skb)
|
|
{
|
|
u16 type;
|
|
__be32 ip_src, ip_dst;
|
|
u8 *hw_src, *hw_dst;
|
|
int hdr_size = 0;
|
|
unsigned short vid;
|
|
|
|
if (!atomic_read(&bat_priv->distributed_arp_table))
|
|
return;
|
|
|
|
vid = batadv_dat_get_vid(skb, &hdr_size);
|
|
|
|
type = batadv_arp_get_type(bat_priv, skb, hdr_size);
|
|
if (type != ARPOP_REPLY)
|
|
return;
|
|
|
|
batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing outgoing ARP REPLY");
|
|
|
|
hw_src = batadv_arp_hw_src(skb, hdr_size);
|
|
ip_src = batadv_arp_ip_src(skb, hdr_size);
|
|
hw_dst = batadv_arp_hw_dst(skb, hdr_size);
|
|
ip_dst = batadv_arp_ip_dst(skb, hdr_size);
|
|
|
|
batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
|
|
batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
|
|
|
|
/* Send the ARP reply to the candidates for both the IP addresses that
|
|
* the node obtained from the ARP reply
|
|
*/
|
|
batadv_dat_forward_data(bat_priv, skb, ip_src, vid,
|
|
BATADV_P_DAT_DHT_PUT);
|
|
batadv_dat_forward_data(bat_priv, skb, ip_dst, vid,
|
|
BATADV_P_DAT_DHT_PUT);
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_snoop_incoming_arp_reply() - snoop the ARP reply and fill the
|
|
* local DAT storage only
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @skb: packet to check
|
|
* @hdr_size: size of the encapsulation header
|
|
*
|
|
* Return: true if the packet was snooped and consumed by DAT. False if the
|
|
* packet has to be delivered to the interface
|
|
*/
|
|
bool batadv_dat_snoop_incoming_arp_reply(struct batadv_priv *bat_priv,
|
|
struct sk_buff *skb, int hdr_size)
|
|
{
|
|
struct batadv_dat_entry *dat_entry = NULL;
|
|
u16 type;
|
|
__be32 ip_src, ip_dst;
|
|
u8 *hw_src, *hw_dst;
|
|
bool dropped = false;
|
|
unsigned short vid;
|
|
|
|
if (!atomic_read(&bat_priv->distributed_arp_table))
|
|
goto out;
|
|
|
|
vid = batadv_dat_get_vid(skb, &hdr_size);
|
|
|
|
type = batadv_arp_get_type(bat_priv, skb, hdr_size);
|
|
if (type != ARPOP_REPLY)
|
|
goto out;
|
|
|
|
batadv_dbg_arp(bat_priv, skb, hdr_size, "Parsing incoming ARP REPLY");
|
|
|
|
hw_src = batadv_arp_hw_src(skb, hdr_size);
|
|
ip_src = batadv_arp_ip_src(skb, hdr_size);
|
|
hw_dst = batadv_arp_hw_dst(skb, hdr_size);
|
|
ip_dst = batadv_arp_ip_dst(skb, hdr_size);
|
|
|
|
/* If ip_dst is already in cache and has the right mac address,
|
|
* drop this frame if this ARP reply is destined for us because it's
|
|
* most probably an ARP reply generated by another node of the DHT.
|
|
* We have most probably received already a reply earlier. Delivering
|
|
* this frame would lead to doubled receive of an ARP reply.
|
|
*/
|
|
dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_src, vid);
|
|
if (dat_entry && batadv_compare_eth(hw_src, dat_entry->mac_addr)) {
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv, "Doubled ARP reply removed: ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]; dat_entry: %pM-%pI4\n",
|
|
hw_src, &ip_src, hw_dst, &ip_dst,
|
|
dat_entry->mac_addr, &dat_entry->ip);
|
|
dropped = true;
|
|
}
|
|
|
|
/* Update our internal cache with both the IP addresses the node got
|
|
* within the ARP reply
|
|
*/
|
|
batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
|
|
batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
|
|
|
|
if (dropped)
|
|
goto out;
|
|
|
|
/* If BLA is enabled, only forward ARP replies if we have claimed the
|
|
* source of the ARP reply or if no one else of the same backbone has
|
|
* already claimed that client. This prevents that different gateways
|
|
* to the same backbone all forward the ARP reply leading to multiple
|
|
* replies in the backbone.
|
|
*/
|
|
if (!batadv_bla_check_claim(bat_priv, hw_src, vid)) {
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
|
"Device %pM claimed by another backbone gw. Drop ARP reply.\n",
|
|
hw_src);
|
|
dropped = true;
|
|
goto out;
|
|
}
|
|
|
|
/* if this REPLY is directed to a client of mine, let's deliver the
|
|
* packet to the interface
|
|
*/
|
|
dropped = !batadv_is_my_client(bat_priv, hw_dst, vid);
|
|
|
|
/* if this REPLY is sent on behalf of a client of mine, let's drop the
|
|
* packet because the client will reply by itself
|
|
*/
|
|
dropped |= batadv_is_my_client(bat_priv, hw_src, vid);
|
|
out:
|
|
if (dropped)
|
|
kfree_skb(skb);
|
|
batadv_dat_entry_put(dat_entry);
|
|
/* if dropped == false -> deliver to the interface */
|
|
return dropped;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_check_dhcp_ipudp() - check skb for IP+UDP headers valid for DHCP
|
|
* @skb: the packet to check
|
|
* @ip_src: a buffer to store the IPv4 source address in
|
|
*
|
|
* Checks whether the given skb has an IP and UDP header valid for a DHCP
|
|
* message from a DHCP server. And if so, stores the IPv4 source address in
|
|
* the provided buffer.
|
|
*
|
|
* Return: True if valid, false otherwise.
|
|
*/
|
|
static bool
|
|
batadv_dat_check_dhcp_ipudp(struct sk_buff *skb, __be32 *ip_src)
|
|
{
|
|
unsigned int offset = skb_network_offset(skb);
|
|
struct udphdr *udphdr, _udphdr;
|
|
struct iphdr *iphdr, _iphdr;
|
|
|
|
iphdr = skb_header_pointer(skb, offset, sizeof(_iphdr), &_iphdr);
|
|
if (!iphdr || iphdr->version != 4 || iphdr->ihl * 4 < sizeof(_iphdr))
|
|
return false;
|
|
|
|
if (iphdr->protocol != IPPROTO_UDP)
|
|
return false;
|
|
|
|
offset += iphdr->ihl * 4;
|
|
skb_set_transport_header(skb, offset);
|
|
|
|
udphdr = skb_header_pointer(skb, offset, sizeof(_udphdr), &_udphdr);
|
|
if (!udphdr || udphdr->source != htons(67))
|
|
return false;
|
|
|
|
*ip_src = get_unaligned(&iphdr->saddr);
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_check_dhcp() - examine packet for valid DHCP message
|
|
* @skb: the packet to check
|
|
* @proto: ethernet protocol hint (behind a potential vlan)
|
|
* @ip_src: a buffer to store the IPv4 source address in
|
|
*
|
|
* Checks whether the given skb is a valid DHCP packet. And if so, stores the
|
|
* IPv4 source address in the provided buffer.
|
|
*
|
|
* Caller needs to ensure that the skb network header is set correctly.
|
|
*
|
|
* Return: If skb is a valid DHCP packet, then returns its op code
|
|
* (e.g. BOOTREPLY vs. BOOTREQUEST). Otherwise returns -EINVAL.
|
|
*/
|
|
static int
|
|
batadv_dat_check_dhcp(struct sk_buff *skb, __be16 proto, __be32 *ip_src)
|
|
{
|
|
__be32 *magic, _magic;
|
|
unsigned int offset;
|
|
struct {
|
|
__u8 op;
|
|
__u8 htype;
|
|
__u8 hlen;
|
|
__u8 hops;
|
|
} *dhcp_h, _dhcp_h;
|
|
|
|
if (proto != htons(ETH_P_IP))
|
|
return -EINVAL;
|
|
|
|
if (!batadv_dat_check_dhcp_ipudp(skb, ip_src))
|
|
return -EINVAL;
|
|
|
|
offset = skb_transport_offset(skb) + sizeof(struct udphdr);
|
|
if (skb->len < offset + sizeof(struct batadv_dhcp_packet))
|
|
return -EINVAL;
|
|
|
|
dhcp_h = skb_header_pointer(skb, offset, sizeof(_dhcp_h), &_dhcp_h);
|
|
if (!dhcp_h || dhcp_h->htype != BATADV_HTYPE_ETHERNET ||
|
|
dhcp_h->hlen != ETH_ALEN)
|
|
return -EINVAL;
|
|
|
|
offset += offsetof(struct batadv_dhcp_packet, magic);
|
|
|
|
magic = skb_header_pointer(skb, offset, sizeof(_magic), &_magic);
|
|
if (!magic || get_unaligned(magic) != htonl(BATADV_DHCP_MAGIC))
|
|
return -EINVAL;
|
|
|
|
return dhcp_h->op;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_get_dhcp_message_type() - get message type of a DHCP packet
|
|
* @skb: the DHCP packet to parse
|
|
*
|
|
* Iterates over the DHCP options of the given DHCP packet to find a
|
|
* DHCP Message Type option and parse it.
|
|
*
|
|
* Caller needs to ensure that the given skb is a valid DHCP packet and
|
|
* that the skb transport header is set correctly.
|
|
*
|
|
* Return: The found DHCP message type value, if found. -EINVAL otherwise.
|
|
*/
|
|
static int batadv_dat_get_dhcp_message_type(struct sk_buff *skb)
|
|
{
|
|
unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr);
|
|
u8 *type, _type;
|
|
struct {
|
|
u8 type;
|
|
u8 len;
|
|
} *tl, _tl;
|
|
|
|
offset += sizeof(struct batadv_dhcp_packet);
|
|
|
|
while ((tl = skb_header_pointer(skb, offset, sizeof(_tl), &_tl))) {
|
|
if (tl->type == BATADV_DHCP_OPT_MSG_TYPE)
|
|
break;
|
|
|
|
if (tl->type == BATADV_DHCP_OPT_END)
|
|
break;
|
|
|
|
if (tl->type == BATADV_DHCP_OPT_PAD)
|
|
offset++;
|
|
else
|
|
offset += tl->len + sizeof(_tl);
|
|
}
|
|
|
|
/* Option Overload Code not supported */
|
|
if (!tl || tl->type != BATADV_DHCP_OPT_MSG_TYPE ||
|
|
tl->len != sizeof(_type))
|
|
return -EINVAL;
|
|
|
|
offset += sizeof(_tl);
|
|
|
|
type = skb_header_pointer(skb, offset, sizeof(_type), &_type);
|
|
if (!type)
|
|
return -EINVAL;
|
|
|
|
return *type;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_dhcp_get_yiaddr() - get yiaddr from a DHCP packet
|
|
* @skb: the DHCP packet to parse
|
|
* @buf: a buffer to store the yiaddr in
|
|
*
|
|
* Caller needs to ensure that the given skb is a valid DHCP packet and
|
|
* that the skb transport header is set correctly.
|
|
*
|
|
* Return: True on success, false otherwise.
|
|
*/
|
|
static bool batadv_dat_dhcp_get_yiaddr(struct sk_buff *skb, __be32 *buf)
|
|
{
|
|
unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr);
|
|
__be32 *yiaddr;
|
|
|
|
offset += offsetof(struct batadv_dhcp_packet, yiaddr);
|
|
yiaddr = skb_header_pointer(skb, offset, BATADV_DHCP_YIADDR_LEN, buf);
|
|
|
|
if (!yiaddr)
|
|
return false;
|
|
|
|
if (yiaddr != buf)
|
|
*buf = get_unaligned(yiaddr);
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_get_dhcp_chaddr() - get chaddr from a DHCP packet
|
|
* @skb: the DHCP packet to parse
|
|
* @buf: a buffer to store the chaddr in
|
|
*
|
|
* Caller needs to ensure that the given skb is a valid DHCP packet and
|
|
* that the skb transport header is set correctly.
|
|
*
|
|
* Return: True on success, false otherwise
|
|
*/
|
|
static bool batadv_dat_get_dhcp_chaddr(struct sk_buff *skb, u8 *buf)
|
|
{
|
|
unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr);
|
|
u8 *chaddr;
|
|
|
|
offset += offsetof(struct batadv_dhcp_packet, chaddr);
|
|
chaddr = skb_header_pointer(skb, offset, BATADV_DHCP_CHADDR_LEN, buf);
|
|
|
|
if (!chaddr)
|
|
return false;
|
|
|
|
if (chaddr != buf)
|
|
memcpy(buf, chaddr, BATADV_DHCP_CHADDR_LEN);
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_put_dhcp() - puts addresses from a DHCP packet into the DHT and
|
|
* DAT cache
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @chaddr: the DHCP client MAC address
|
|
* @yiaddr: the DHCP client IP address
|
|
* @hw_dst: the DHCP server MAC address
|
|
* @ip_dst: the DHCP server IP address
|
|
* @vid: VLAN identifier
|
|
*
|
|
* Adds given MAC/IP pairs to the local DAT cache and propagates them further
|
|
* into the DHT.
|
|
*
|
|
* For the DHT propagation, client MAC + IP will appear as the ARP Reply
|
|
* transmitter (and hw_dst/ip_dst as the target).
|
|
*/
|
|
static void batadv_dat_put_dhcp(struct batadv_priv *bat_priv, u8 *chaddr,
|
|
__be32 yiaddr, u8 *hw_dst, __be32 ip_dst,
|
|
unsigned short vid)
|
|
{
|
|
struct sk_buff *skb;
|
|
|
|
skb = batadv_dat_arp_create_reply(bat_priv, yiaddr, ip_dst, chaddr,
|
|
hw_dst, vid);
|
|
if (!skb)
|
|
return;
|
|
|
|
skb_set_network_header(skb, ETH_HLEN);
|
|
|
|
batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid);
|
|
batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
|
|
|
|
batadv_dat_forward_data(bat_priv, skb, yiaddr, vid,
|
|
BATADV_P_DAT_DHT_PUT);
|
|
batadv_dat_forward_data(bat_priv, skb, ip_dst, vid,
|
|
BATADV_P_DAT_DHT_PUT);
|
|
|
|
consume_skb(skb);
|
|
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
|
"Snooped from outgoing DHCPACK (server address): %pI4, %pM (vid: %i)\n",
|
|
&ip_dst, hw_dst, batadv_print_vid(vid));
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
|
"Snooped from outgoing DHCPACK (client address): %pI4, %pM (vid: %i)\n",
|
|
&yiaddr, chaddr, batadv_print_vid(vid));
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_check_dhcp_ack() - examine packet for valid DHCP message
|
|
* @skb: the packet to check
|
|
* @proto: ethernet protocol hint (behind a potential vlan)
|
|
* @ip_src: a buffer to store the IPv4 source address in
|
|
* @chaddr: a buffer to store the DHCP Client Hardware Address in
|
|
* @yiaddr: a buffer to store the DHCP Your IP Address in
|
|
*
|
|
* Checks whether the given skb is a valid DHCPACK. And if so, stores the
|
|
* IPv4 server source address (ip_src), client MAC address (chaddr) and client
|
|
* IPv4 address (yiaddr) in the provided buffers.
|
|
*
|
|
* Caller needs to ensure that the skb network header is set correctly.
|
|
*
|
|
* Return: True if the skb is a valid DHCPACK. False otherwise.
|
|
*/
|
|
static bool
|
|
batadv_dat_check_dhcp_ack(struct sk_buff *skb, __be16 proto, __be32 *ip_src,
|
|
u8 *chaddr, __be32 *yiaddr)
|
|
{
|
|
int type;
|
|
|
|
type = batadv_dat_check_dhcp(skb, proto, ip_src);
|
|
if (type != BATADV_BOOTREPLY)
|
|
return false;
|
|
|
|
type = batadv_dat_get_dhcp_message_type(skb);
|
|
if (type != BATADV_DHCPACK)
|
|
return false;
|
|
|
|
if (!batadv_dat_dhcp_get_yiaddr(skb, yiaddr))
|
|
return false;
|
|
|
|
if (!batadv_dat_get_dhcp_chaddr(skb, chaddr))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_snoop_outgoing_dhcp_ack() - snoop DHCPACK and fill DAT with it
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @skb: the packet to snoop
|
|
* @proto: ethernet protocol hint (behind a potential vlan)
|
|
* @vid: VLAN identifier
|
|
*
|
|
* This function first checks whether the given skb is a valid DHCPACK. If
|
|
* so then its source MAC and IP as well as its DHCP Client Hardware Address
|
|
* field and DHCP Your IP Address field are added to the local DAT cache and
|
|
* propagated into the DHT.
|
|
*
|
|
* Caller needs to ensure that the skb mac and network headers are set
|
|
* correctly.
|
|
*/
|
|
void batadv_dat_snoop_outgoing_dhcp_ack(struct batadv_priv *bat_priv,
|
|
struct sk_buff *skb,
|
|
__be16 proto,
|
|
unsigned short vid)
|
|
{
|
|
u8 chaddr[BATADV_DHCP_CHADDR_LEN];
|
|
__be32 ip_src, yiaddr;
|
|
|
|
if (!atomic_read(&bat_priv->distributed_arp_table))
|
|
return;
|
|
|
|
if (!batadv_dat_check_dhcp_ack(skb, proto, &ip_src, chaddr, &yiaddr))
|
|
return;
|
|
|
|
batadv_dat_put_dhcp(bat_priv, chaddr, yiaddr, eth_hdr(skb)->h_source,
|
|
ip_src, vid);
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_snoop_incoming_dhcp_ack() - snoop DHCPACK and fill DAT cache
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @skb: the packet to snoop
|
|
* @hdr_size: header size, up to the tail of the batman-adv header
|
|
*
|
|
* This function first checks whether the given skb is a valid DHCPACK. If
|
|
* so then its source MAC and IP as well as its DHCP Client Hardware Address
|
|
* field and DHCP Your IP Address field are added to the local DAT cache.
|
|
*/
|
|
void batadv_dat_snoop_incoming_dhcp_ack(struct batadv_priv *bat_priv,
|
|
struct sk_buff *skb, int hdr_size)
|
|
{
|
|
u8 chaddr[BATADV_DHCP_CHADDR_LEN];
|
|
struct ethhdr *ethhdr;
|
|
__be32 ip_src, yiaddr;
|
|
unsigned short vid;
|
|
__be16 proto;
|
|
u8 *hw_src;
|
|
|
|
if (!atomic_read(&bat_priv->distributed_arp_table))
|
|
return;
|
|
|
|
if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
|
|
return;
|
|
|
|
ethhdr = (struct ethhdr *)(skb->data + hdr_size);
|
|
skb_set_network_header(skb, hdr_size + ETH_HLEN);
|
|
proto = ethhdr->h_proto;
|
|
|
|
if (!batadv_dat_check_dhcp_ack(skb, proto, &ip_src, chaddr, &yiaddr))
|
|
return;
|
|
|
|
hw_src = ethhdr->h_source;
|
|
vid = batadv_dat_get_vid(skb, &hdr_size);
|
|
|
|
batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid);
|
|
batadv_dat_entry_add(bat_priv, ip_src, hw_src, vid);
|
|
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
|
"Snooped from incoming DHCPACK (server address): %pI4, %pM (vid: %i)\n",
|
|
&ip_src, hw_src, batadv_print_vid(vid));
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
|
"Snooped from incoming DHCPACK (client address): %pI4, %pM (vid: %i)\n",
|
|
&yiaddr, chaddr, batadv_print_vid(vid));
|
|
}
|
|
|
|
/**
|
|
* batadv_dat_drop_broadcast_packet() - check if an ARP request has to be
|
|
* dropped (because the node has already obtained the reply via DAT) or not
|
|
* @bat_priv: the bat priv with all the soft interface information
|
|
* @forw_packet: the broadcast packet
|
|
*
|
|
* Return: true if the node can drop the packet, false otherwise.
|
|
*/
|
|
bool batadv_dat_drop_broadcast_packet(struct batadv_priv *bat_priv,
|
|
struct batadv_forw_packet *forw_packet)
|
|
{
|
|
u16 type;
|
|
__be32 ip_dst;
|
|
struct batadv_dat_entry *dat_entry = NULL;
|
|
bool ret = false;
|
|
int hdr_size = sizeof(struct batadv_bcast_packet);
|
|
unsigned short vid;
|
|
|
|
if (!atomic_read(&bat_priv->distributed_arp_table))
|
|
goto out;
|
|
|
|
/* If this packet is an ARP_REQUEST and the node already has the
|
|
* information that it is going to ask, then the packet can be dropped
|
|
*/
|
|
if (batadv_forw_packet_is_rebroadcast(forw_packet))
|
|
goto out;
|
|
|
|
vid = batadv_dat_get_vid(forw_packet->skb, &hdr_size);
|
|
|
|
type = batadv_arp_get_type(bat_priv, forw_packet->skb, hdr_size);
|
|
if (type != ARPOP_REQUEST)
|
|
goto out;
|
|
|
|
ip_dst = batadv_arp_ip_dst(forw_packet->skb, hdr_size);
|
|
dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst, vid);
|
|
/* check if the node already got this entry */
|
|
if (!dat_entry) {
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
|
"ARP Request for %pI4: fallback\n", &ip_dst);
|
|
goto out;
|
|
}
|
|
|
|
batadv_dbg(BATADV_DBG_DAT, bat_priv,
|
|
"ARP Request for %pI4: fallback prevented\n", &ip_dst);
|
|
ret = true;
|
|
|
|
out:
|
|
batadv_dat_entry_put(dat_entry);
|
|
return ret;
|
|
}
|