227 lines
7.9 KiB
Diff
227 lines
7.9 KiB
Diff
From 3d999e5116f44b47c742aa16d6382721c360a6d0 Mon Sep 17 00:00:00 2001
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From: Simon Wunderlich <simon@open-mesh.com>
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Date: Thu, 23 May 2013 13:07:42 +0200
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Subject: [PATCH 10/10] batman-adv: forward late OGMs from best next hop
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When a packet is received from another node first and later from the
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best next hop, this packet is dropped. However the first OGM was sent
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with the BATADV_NOT_BEST_NEXT_HOP flag and thus dropped by neighbors.
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The late OGM from the best neighbor is then dropped because it is a
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duplicate.
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If this situation happens constantly, a node might end up not forwarding
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the "valid" OGMs anymore, and nodes behind will starve from not getting
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valid OGMs.
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Fix this by refining the duplicate checking behaviour: The actions
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should depend on whether it was a duplicate for a neighbor only or for
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the originator. OGMs which are not duplicates for a specific neighbor
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will now be considered in batadv_iv_ogm_forward(), but only actually
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forwarded for the best next hop. Therefore, late OGMs from the best
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next hop are forwarded now and not dropped as duplicates anymore.
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Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
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Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
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---
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bat_iv_ogm.c | 86 +++++++++++++++++++++++++++++++++++++---------------------
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1 file changed, 55 insertions(+), 31 deletions(-)
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diff --git a/bat_iv_ogm.c b/bat_iv_ogm.c
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index 071f288..f680ee1 100644
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--- a/bat_iv_ogm.c
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+++ b/bat_iv_ogm.c
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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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+
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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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-
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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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+
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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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-
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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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--
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1.7.10.4
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