diff options
| -rw-r--r-- | net/batman-adv/bridge_loop_avoidance.c | 75 | ||||
| -rw-r--r-- | net/batman-adv/bridge_loop_avoidance.h | 2 | ||||
| -rw-r--r-- | net/batman-adv/main.h | 3 | ||||
| -rw-r--r-- | net/batman-adv/routing.c | 4 | ||||
| -rw-r--r-- | net/batman-adv/types.h | 7 |
5 files changed, 91 insertions, 0 deletions
diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 6186f6e..4f6b44a 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -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; @@ -1060,6 +1068,73 @@ int bla_init(struct bat_priv *bat_priv) /** * @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 * * check if the originator is a gateway for any VLAN ID. diff --git a/net/batman-adv/bridge_loop_avoidance.h b/net/batman-adv/bridge_loop_avoidance.h index b74940f..9468c24 100644 --- a/net/batman-adv/bridge_loop_avoidance.h +++ b/net/batman-adv/bridge_loop_avoidance.h @@ -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); diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h index 82723b5..d9832ac 100644 --- a/net/batman-adv/main.h +++ b/net/batman-adv/main.h @@ -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 diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 1d1fd04..78eddc9 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -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); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 35cd831..ad97e87 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -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 */ |
