batman-adv: add broadcast duplicate check (fe2da6ff) · Commits · 戴 / test

net/batman-adv/bridge_loop_avoidance.c

+75 −0

Original line number	Diff line number	Diff line
		@@ -1041,8 +1041,16 @@ out:
		/* initialize all bla structures */
		int bla_init(struct bat_priv *bat_priv)
		{
		int i;

		bat_dbg(DBG_BLA, bat_priv, "bla hash registering\n");

		/* initialize the duplicate list */
		for (i = 0; i < DUPLIST_SIZE; i++)
		bat_priv->bcast_duplist[i].entrytime =
		jiffies - msecs_to_jiffies(DUPLIST_TIMEOUT);
		bat_priv->bcast_duplist_curr = 0;

		if (bat_priv->claim_hash)
		return 1;

		@@ -1058,6 +1066,73 @@ int bla_init(struct bat_priv *bat_priv)
		return 1;
		}

		/**
		* @bat_priv: the bat priv with all the soft interface information
		* @bcast_packet: originator mac address
		* @hdr_size: maximum length of the frame
		*
		* check if it is on our broadcast list. Another gateway might
		* have sent the same packet because it is connected to the same backbone,
		* so we have to remove this duplicate.
		*
		* This is performed by checking the CRC, which will tell us
		* with a good chance that it is the same packet. If it is furthermore
		* sent by another host, drop it. We allow equal packets from
		* the same host however as this might be intended.
		*
		**/

		int bla_check_bcast_duplist(struct bat_priv *bat_priv,
		struct bcast_packet *bcast_packet,
		int hdr_size)
		{
		int i, length, curr;
		uint8_t *content;
		uint16_t crc;
		struct bcast_duplist_entry *entry;

		length = hdr_size - sizeof(*bcast_packet);
		content = (uint8_t *)bcast_packet;
		content += sizeof(*bcast_packet);

		/* calculate the crc ... */
		crc = crc16(0, content, length);

		for (i = 0 ; i < DUPLIST_SIZE; i++) {
		curr = (bat_priv->bcast_duplist_curr + i) % DUPLIST_SIZE;
		entry = &bat_priv->bcast_duplist[curr];

		/* we can stop searching if the entry is too old ;
		* later entries will be even older
		*/
		if (has_timed_out(entry->entrytime, DUPLIST_TIMEOUT))
		break;

		if (entry->crc != crc)
		continue;

		if (compare_eth(entry->orig, bcast_packet->orig))
		continue;

		/* this entry seems to match: same crc, not too old,
		* and from another gw. therefore return 1 to forbid it.
		*/
		return 1;
		}
		/* not found, add a new entry (overwrite the oldest entry) */
		curr = (bat_priv->bcast_duplist_curr + DUPLIST_SIZE - 1) % DUPLIST_SIZE;
		entry = &bat_priv->bcast_duplist[curr];
		entry->crc = crc;
		entry->entrytime = jiffies;
		memcpy(entry->orig, bcast_packet->orig, ETH_ALEN);
		bat_priv->bcast_duplist_curr = curr;

		/* allow it, its the first occurence. */
		return 0;
		}



		/**
		* @bat_priv: the bat priv with all the soft interface information
		* @orig: originator mac address

net/batman-adv/bridge_loop_avoidance.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -28,6 +28,8 @@ int bla_is_backbone_gw(struct sk_buff *skb,
		struct orig_node *orig_node, int hdr_size);
		int bla_claim_table_seq_print_text(struct seq_file seq, void offset);
		int bla_is_backbone_gw_orig(struct bat_priv bat_priv, uint8_t orig);
		int bla_check_bcast_duplist(struct bat_priv *bat_priv,
		struct bcast_packet *bcast_packet, int hdr_size);
		void bla_update_orig_address(struct bat_priv *bat_priv,
		struct hard_iface *primary_if,
		struct hard_iface *oldif);

net/batman-adv/main.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -83,6 +83,9 @@
		#define BLA_PERIOD_LENGTH 10000 /* 10 seconds */
		#define BLA_BACKBONE_TIMEOUT (BLA_PERIOD_LENGTH * 3)
		#define BLA_CLAIM_TIMEOUT (BLA_PERIOD_LENGTH * 10)

		#define DUPLIST_SIZE 16
		#define DUPLIST_TIMEOUT 500 /* 500 ms */
		/* don't reset again within 30 seconds */
		#define RESET_PROTECTION_MS 30000
		#define EXPECTED_SEQNO_RANGE 65536

net/batman-adv/routing.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -1076,6 +1076,10 @@ int recv_bcast_packet(struct sk_buff skb, struct hard_iface recv_if)

		spin_unlock_bh(&orig_node->bcast_seqno_lock);

		/* check whether this has been sent by another originator before */
		if (bla_check_bcast_duplist(bat_priv, bcast_packet, hdr_size))
		goto out;

		/* rebroadcast packet */
		add_bcast_packet_to_list(bat_priv, skb, 1);

net/batman-adv/types.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -140,6 +140,11 @@ struct neigh_node {
		spinlock_t tq_lock; /* protects: tq_recv, tq_index */
		};

		struct bcast_duplist_entry {
		uint8_t orig[ETH_ALEN];
		uint16_t crc;
		unsigned long entrytime;
		};

		struct bat_priv {
		atomic_t mesh_state;
		@@ -186,6 +191,8 @@ struct bat_priv {
		struct list_head tt_req_list; /* list of pending tt_requests */
		struct list_head tt_roam_list;
		struct hashtable_t *vis_hash;
		struct bcast_duplist_entry bcast_duplist[DUPLIST_SIZE];
		int bcast_duplist_curr;
		spinlock_t forw_bat_list_lock; /* protects forw_bat_list */
		spinlock_t forw_bcast_list_lock; /* protects */
		spinlock_t tt_changes_list_lock; /* protects tt_changes */

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