batman-adv: forward late OGMs from best next hop
When a packet is received from another node first and later from the best next hop, this packet is dropped. However the first OGM was sent with the BATADV_NOT_BEST_NEXT_HOP flag and thus dropped by neighbors. The late OGM from the best neighbor is then dropped because it is a duplicate. If this situation happens constantly, a node might end up not forwarding the "valid" OGMs anymore, and nodes behind will starve from not getting valid OGMs. Fix this by refining the duplicate checking behaviour: The actions should depend on whether it was a duplicate for a neighbor only or for the originator. OGMs which are not duplicates for a specific neighbor will now be considered in batadv_iv_ogm_forward(), but only actually forwarded for the best next hop. Therefore, late OGMs from the best next hop are forwarded now and not dropped as duplicates anymore. Signed-off-by: Simon Wunderlich <simon@open-mesh.com> Signed-off-by: Marek Lindner <lindner_marek@yahoo.de> Signed-off-by: Antonio Quartulli <ordex@autistici.org>
This commit is contained in:
Simon Wunderlich
Antonio Quartulli
Родитель
ac16d1484e
Коммит
7c24bbbeab
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@ -29,6 +29,21 @@
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#include "bat_algo.h"
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#include "network-coding.h"
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/**
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* batadv_dup_status - duplicate status
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* @BATADV_NO_DUP: the packet is a duplicate
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* @BATADV_ORIG_DUP: OGM is a duplicate in the originator (but not for the
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* neighbor)
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* @BATADV_NEIGH_DUP: OGM is a duplicate for the neighbor
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* @BATADV_PROTECTED: originator is currently protected (after reboot)
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*/
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enum batadv_dup_status {
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BATADV_NO_DUP = 0,
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BATADV_ORIG_DUP,
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BATADV_NEIGH_DUP,
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BATADV_PROTECTED,
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};
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static struct batadv_neigh_node *
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batadv_iv_ogm_neigh_new(struct batadv_hard_iface *hard_iface,
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const uint8_t *neigh_addr,
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@ -650,7 +665,7 @@ batadv_iv_ogm_orig_update(struct batadv_priv *bat_priv,
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const struct batadv_ogm_packet *batadv_ogm_packet,
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struct batadv_hard_iface *if_incoming,
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const unsigned char *tt_buff,
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int is_duplicate)
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enum batadv_dup_status dup_status)
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{
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struct batadv_neigh_node *neigh_node = NULL, *tmp_neigh_node = NULL;
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struct batadv_neigh_node *router = NULL;
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@ -676,7 +691,7 @@ batadv_iv_ogm_orig_update(struct batadv_priv *bat_priv,
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continue;
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}
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if (is_duplicate)
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if (dup_status != BATADV_NO_DUP)
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continue;
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spin_lock_bh(&tmp_neigh_node->lq_update_lock);
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@ -718,7 +733,7 @@ batadv_iv_ogm_orig_update(struct batadv_priv *bat_priv,
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neigh_node->tq_avg = batadv_ring_buffer_avg(neigh_node->tq_recv);
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spin_unlock_bh(&neigh_node->lq_update_lock);
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if (!is_duplicate) {
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if (dup_status == BATADV_NO_DUP) {
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orig_node->last_ttl = batadv_ogm_packet->header.ttl;
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neigh_node->last_ttl = batadv_ogm_packet->header.ttl;
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}
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@ -902,15 +917,16 @@ out:
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return ret;
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}
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/* processes a batman packet for all interfaces, adjusts the sequence number and
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* finds out whether it is a duplicate.
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* returns:
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* 1 the packet is a duplicate
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* 0 the packet has not yet been received
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* -1 the packet is old and has been received while the seqno window
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* was protected. Caller should drop it.
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/**
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* batadv_iv_ogm_update_seqnos - process a batman packet for all interfaces,
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* adjust the sequence number and find out whether it is a duplicate
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* @ethhdr: ethernet header of the packet
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* @batadv_ogm_packet: OGM packet to be considered
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* @if_incoming: interface on which the OGM packet was received
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*
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* Returns duplicate status as enum batadv_dup_status
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*/
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static int
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static enum batadv_dup_status
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batadv_iv_ogm_update_seqnos(const struct ethhdr *ethhdr,
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const struct batadv_ogm_packet *batadv_ogm_packet,
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const struct batadv_hard_iface *if_incoming)
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@ -918,17 +934,18 @@ batadv_iv_ogm_update_seqnos(const struct ethhdr *ethhdr,
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struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
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struct batadv_orig_node *orig_node;
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struct batadv_neigh_node *tmp_neigh_node;
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int is_duplicate = 0;
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int is_dup;
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int32_t seq_diff;
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int need_update = 0;
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int set_mark, ret = -1;
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int set_mark;
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enum batadv_dup_status ret = BATADV_NO_DUP;
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uint32_t seqno = ntohl(batadv_ogm_packet->seqno);
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uint8_t *neigh_addr;
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uint8_t packet_count;
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orig_node = batadv_get_orig_node(bat_priv, batadv_ogm_packet->orig);
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if (!orig_node)
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return 0;
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return BATADV_NO_DUP;
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spin_lock_bh(&orig_node->ogm_cnt_lock);
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seq_diff = seqno - orig_node->last_real_seqno;
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@ -936,22 +953,29 @@ batadv_iv_ogm_update_seqnos(const struct ethhdr *ethhdr,
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/* signalize caller that the packet is to be dropped. */
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if (!hlist_empty(&orig_node->neigh_list) &&
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batadv_window_protected(bat_priv, seq_diff,
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&orig_node->batman_seqno_reset))
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&orig_node->batman_seqno_reset)) {
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ret = BATADV_PROTECTED;
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goto out;
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}
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rcu_read_lock();
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hlist_for_each_entry_rcu(tmp_neigh_node,
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&orig_node->neigh_list, list) {
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is_duplicate |= batadv_test_bit(tmp_neigh_node->real_bits,
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orig_node->last_real_seqno,
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seqno);
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neigh_addr = tmp_neigh_node->addr;
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is_dup = batadv_test_bit(tmp_neigh_node->real_bits,
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orig_node->last_real_seqno,
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seqno);
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if (batadv_compare_eth(neigh_addr, ethhdr->h_source) &&
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tmp_neigh_node->if_incoming == if_incoming)
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tmp_neigh_node->if_incoming == if_incoming) {
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set_mark = 1;
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else
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if (is_dup)
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ret = BATADV_NEIGH_DUP;
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} else {
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set_mark = 0;
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if (is_dup && (ret != BATADV_NEIGH_DUP))
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ret = BATADV_ORIG_DUP;
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}
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/* if the window moved, set the update flag. */
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need_update |= batadv_bit_get_packet(bat_priv,
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@ -971,8 +995,6 @@ batadv_iv_ogm_update_seqnos(const struct ethhdr *ethhdr,
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orig_node->last_real_seqno = seqno;
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}
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ret = is_duplicate;
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out:
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spin_unlock_bh(&orig_node->ogm_cnt_lock);
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batadv_orig_node_free_ref(orig_node);
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@ -994,7 +1016,8 @@ static void batadv_iv_ogm_process(const struct ethhdr *ethhdr,
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int is_broadcast = 0, is_bidirect;
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bool is_single_hop_neigh = false;
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bool is_from_best_next_hop = false;
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int is_duplicate, sameseq, simlar_ttl;
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int sameseq, similar_ttl;
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enum batadv_dup_status dup_status;
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uint32_t if_incoming_seqno;
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uint8_t *prev_sender;
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@ -1138,10 +1161,10 @@ static void batadv_iv_ogm_process(const struct ethhdr *ethhdr,
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if (!orig_node)
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return;
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is_duplicate = batadv_iv_ogm_update_seqnos(ethhdr, batadv_ogm_packet,
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if_incoming);
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dup_status = batadv_iv_ogm_update_seqnos(ethhdr, batadv_ogm_packet,
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if_incoming);
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if (is_duplicate == -1) {
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if (dup_status == BATADV_PROTECTED) {
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batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
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"Drop packet: packet within seqno protection time (sender: %pM)\n",
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ethhdr->h_source);
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@ -1211,11 +1234,12 @@ static void batadv_iv_ogm_process(const struct ethhdr *ethhdr,
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* seqno and similar ttl as the non-duplicate
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*/
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sameseq = orig_node->last_real_seqno == ntohl(batadv_ogm_packet->seqno);
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simlar_ttl = orig_node->last_ttl - 3 <= batadv_ogm_packet->header.ttl;
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if (is_bidirect && (!is_duplicate || (sameseq && simlar_ttl)))
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similar_ttl = orig_node->last_ttl - 3 <= batadv_ogm_packet->header.ttl;
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if (is_bidirect && ((dup_status == BATADV_NO_DUP) ||
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(sameseq && similar_ttl)))
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batadv_iv_ogm_orig_update(bat_priv, orig_node, ethhdr,
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batadv_ogm_packet, if_incoming,
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tt_buff, is_duplicate);
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tt_buff, dup_status);
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/* is single hop (direct) neighbor */
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if (is_single_hop_neigh) {
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@ -1236,7 +1260,7 @@ static void batadv_iv_ogm_process(const struct ethhdr *ethhdr,
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goto out_neigh;
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}
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if (is_duplicate) {
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if (dup_status == BATADV_NEIGH_DUP) {
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batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
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"Drop packet: duplicate packet received\n");
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goto out_neigh;
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