diff options
| -rw-r--r-- | drivers/staging/batman-adv/bitarray.c | 74 | ||||
| -rw-r--r-- | drivers/staging/batman-adv/main.h | 4 | ||||
| -rw-r--r-- | drivers/staging/batman-adv/originator.c | 2 | ||||
| -rw-r--r-- | drivers/staging/batman-adv/routing.c | 99 | ||||
| -rw-r--r-- | drivers/staging/batman-adv/types.h | 4 |
5 files changed, 136 insertions, 47 deletions
diff --git a/drivers/staging/batman-adv/bitarray.c b/drivers/staging/batman-adv/bitarray.c index 7848305bd14..2fef6e35f8c 100644 --- a/drivers/staging/batman-adv/bitarray.c +++ b/drivers/staging/batman-adv/bitarray.c @@ -68,7 +68,7 @@ void bit_shift(TYPE_OF_WORD *seq_bits, int32_t n) int32_t word_offset, word_num; int32_t i; - if (n <= 0) + if (n <= 0 || n >= TQ_LOCAL_WINDOW_SIZE) return; word_offset = n % WORD_BIT_SIZE;/* shift how much inside each word */ @@ -111,48 +111,76 @@ void bit_shift(TYPE_OF_WORD *seq_bits, int32_t n) seq_bits[i] = 0; } +static void bit_reset_window(TYPE_OF_WORD *seq_bits) +{ + int i; + for (i = 0; i < NUM_WORDS; i++) + seq_bits[i] = 0; +} + -/* receive and process one packet, returns 1 if received seq_num is considered - * new, 0 if old */ +/* receive and process one packet within the sequence number window. + * + * returns: + * 1 if the window was moved (either new or very old) + * 0 if the window was not moved/shifted. + */ char bit_get_packet(TYPE_OF_WORD *seq_bits, int16_t seq_num_diff, int8_t set_mark) { - int i; + /* sequence number is slightly older. We already got a sequence number + * higher than this one, so we just mark it. */ - /* we already got a sequence number higher than this one, so we just - * mark it. this should wrap around the integer just fine */ - if ((seq_num_diff < 0) && (seq_num_diff >= -TQ_LOCAL_WINDOW_SIZE)) { + if ((seq_num_diff <= 0) && (seq_num_diff > -TQ_LOCAL_WINDOW_SIZE)) { if (set_mark) bit_mark(seq_bits, -seq_num_diff); return 0; } - /* it seems we missed a lot of packets or the other host restarted */ - if ((seq_num_diff > TQ_LOCAL_WINDOW_SIZE) || - (seq_num_diff < -TQ_LOCAL_WINDOW_SIZE)) { + /* sequence number is slightly newer, so we shift the window and + * set the mark if required */ - if (seq_num_diff > TQ_LOCAL_WINDOW_SIZE) - bat_dbg(DBG_BATMAN, - "We missed a lot of packets (%i) !\n", - seq_num_diff-1); + if ((seq_num_diff > 0) && (seq_num_diff < TQ_LOCAL_WINDOW_SIZE)) { + bit_shift(seq_bits, seq_num_diff); - if (-seq_num_diff > TQ_LOCAL_WINDOW_SIZE) - bat_dbg(DBG_BATMAN, - "Other host probably restarted !\n"); + if (set_mark) + bit_mark(seq_bits, 0); + return 1; + } - for (i = 0; i < NUM_WORDS; i++) - seq_bits[i] = 0; + /* sequence number is much newer, probably missed a lot of packets */ + if ((seq_num_diff >= TQ_LOCAL_WINDOW_SIZE) + || (seq_num_diff < EXPECTED_SEQNO_RANGE)) { + bat_dbg(DBG_BATMAN, + "We missed a lot of packets (%i) !\n", + seq_num_diff - 1); + bit_reset_window(seq_bits); if (set_mark) - seq_bits[0] = 1; /* we only have the latest packet */ - } else { - bit_shift(seq_bits, seq_num_diff); + bit_mark(seq_bits, 0); + return 1; + } + + /* received a much older packet. The other host either restarted + * or the old packet got delayed somewhere in the network. The + * packet should be dropped without calling this function if the + * seqno window is protected. */ + + if ((seq_num_diff <= -TQ_LOCAL_WINDOW_SIZE) + || (seq_num_diff >= EXPECTED_SEQNO_RANGE)) { + bat_dbg(DBG_BATMAN, + "Other host probably restarted!\n"); + + bit_reset_window(seq_bits); if (set_mark) bit_mark(seq_bits, 0); + + return 1; } - return 1; + /* never reached */ + return 0; } /* count the hamming weight, how many good packets did we receive? just count diff --git a/drivers/staging/batman-adv/main.h b/drivers/staging/batman-adv/main.h index 247196ca751..58c1ec16741 100644 --- a/drivers/staging/batman-adv/main.h +++ b/drivers/staging/batman-adv/main.h @@ -61,6 +61,10 @@ * forw_packet->direct_link_flags */ #define MAX_AGGREGATION_MS 100 +#define RESET_PROTECTION_MS 30000 +#define EXPECTED_SEQNO_RANGE 4096 +/* don't reset again within 30 seconds */ + #define MODULE_INACTIVE 0 #define MODULE_ACTIVE 1 #define MODULE_DEACTIVATING 2 diff --git a/drivers/staging/batman-adv/originator.c b/drivers/staging/batman-adv/originator.c index 44bbe894152..01d71d7ed42 100644 --- a/drivers/staging/batman-adv/originator.c +++ b/drivers/staging/batman-adv/originator.c @@ -140,6 +140,8 @@ struct orig_node *get_orig_node(uint8_t *addr) memcpy(orig_node->orig, addr, ETH_ALEN); orig_node->router = NULL; orig_node->hna_buff = NULL; + orig_node->bcast_seqno_reset = jiffies - msecs_to_jiffies(RESET_PROTECTION_MS) - 1; + orig_node->batman_seqno_reset = jiffies - msecs_to_jiffies(RESET_PROTECTION_MS) - 1; size = bat_priv->num_ifaces * sizeof(TYPE_OF_WORD) * NUM_WORDS; diff --git a/drivers/staging/batman-adv/routing.c b/drivers/staging/batman-adv/routing.c index 7b8aa27ed28..bf67059e3ee 100644 --- a/drivers/staging/batman-adv/routing.c +++ b/drivers/staging/batman-adv/routing.c @@ -304,6 +304,38 @@ update_hna: update_routes(orig_node, orig_node->router, hna_buff, tmp_hna_buff_len); } +/* checks whether the host restarted and is in the protection time. + * returns: + * 0 if the packet is to be accepted + * 1 if the packet is to be ignored. + */ +static int window_protected(int16_t seq_num_diff, + unsigned long *last_reset) +{ + if ((seq_num_diff <= -TQ_LOCAL_WINDOW_SIZE) + || (seq_num_diff >= EXPECTED_SEQNO_RANGE)) { + if (time_after(jiffies, *last_reset + + msecs_to_jiffies(RESET_PROTECTION_MS))) { + + *last_reset = jiffies; + bat_dbg(DBG_BATMAN, + "old packet received, start protection\n"); + + return 0; + } else + return 1; + } + return 0; +} + +/* processes a batman packet for all interfaces, adjusts the sequence number and + * finds out whether it is a duplicate. + * returns: + * 1 the packet is a duplicate + * 0 the packet has not yet been received + * -1 the packet is old and has been received while the seqno window + * was protected. Caller should drop it. + */ static char count_real_packets(struct ethhdr *ethhdr, struct batman_packet *batman_packet, struct batman_if *if_incoming) @@ -311,31 +343,41 @@ static char count_real_packets(struct ethhdr *ethhdr, struct orig_node *orig_node; struct neigh_node *tmp_neigh_node; char is_duplicate = 0; - uint16_t seq_diff; + int16_t seq_diff; + int need_update = 0; + int set_mark; orig_node = get_orig_node(batman_packet->orig); if (orig_node == NULL) return 0; + seq_diff = batman_packet->seqno - orig_node->last_real_seqno; + + /* signalize caller that the packet is to be dropped. */ + if (window_protected(seq_diff, &orig_node->batman_seqno_reset)) + return -1; + list_for_each_entry(tmp_neigh_node, &orig_node->neigh_list, list) { - if (!is_duplicate) - is_duplicate = - get_bit_status(tmp_neigh_node->real_bits, + is_duplicate |= get_bit_status(tmp_neigh_node->real_bits, orig_node->last_real_seqno, batman_packet->seqno); - seq_diff = batman_packet->seqno - orig_node->last_real_seqno; + if (compare_orig(tmp_neigh_node->addr, ethhdr->h_source) && (tmp_neigh_node->if_incoming == if_incoming)) - bit_get_packet(tmp_neigh_node->real_bits, seq_diff, 1); + set_mark = 1; else - bit_get_packet(tmp_neigh_node->real_bits, seq_diff, 0); + set_mark = 0; + + /* if the window moved, set the update flag. */ + need_update |= bit_get_packet(tmp_neigh_node->real_bits, + seq_diff, set_mark); tmp_neigh_node->real_packet_count = bit_packet_count(tmp_neigh_node->real_bits); } - if (!is_duplicate) { + if (need_update) { bat_dbg(DBG_BATMAN, "updating last_seqno: old %d, new %d\n", orig_node->last_real_seqno, batman_packet->seqno); orig_node->last_real_seqno = batman_packet->seqno; @@ -453,24 +495,27 @@ void receive_bat_packet(struct ethhdr *ethhdr, return; } - if (batman_packet->tq == 0) { - count_real_packets(ethhdr, batman_packet, if_incoming); - - bat_dbg(DBG_BATMAN, "Drop packet: originator packet with tq equal 0\n"); - return; - } - if (is_my_oldorig) { bat_dbg(DBG_BATMAN, "Drop packet: ignoring all rebroadcast echos (sender: %pM)\n", ethhdr->h_source); return; } - is_duplicate = count_real_packets(ethhdr, batman_packet, if_incoming); - orig_node = get_orig_node(batman_packet->orig); if (orig_node == NULL) return; + is_duplicate = count_real_packets(ethhdr, batman_packet, if_incoming); + + if (is_duplicate == -1) { + bat_dbg(DBG_BATMAN, "Drop packet: packet within seqno protection time (sender: %pM)\n", ethhdr->h_source); + return; + } + + if (batman_packet->tq == 0) { + bat_dbg(DBG_BATMAN, "Drop packet: originator packet with tq equal 0\n"); + return; + } + /* avoid temporary routing loops */ if ((orig_node->router) && (orig_node->router->orig_node->router) && @@ -866,13 +911,13 @@ int recv_unicast_packet(struct sk_buff *skb) return ret; } - int recv_bcast_packet(struct sk_buff *skb) { struct orig_node *orig_node; struct bcast_packet *bcast_packet; struct ethhdr *ethhdr; int hdr_size = sizeof(struct bcast_packet); + int16_t seq_diff; unsigned long flags; /* drop packet if it has not necessary minimum size */ @@ -908,7 +953,7 @@ int recv_bcast_packet(struct sk_buff *skb) return NET_RX_DROP; } - /* check flood history */ + /* check whether the packet is a duplicate */ if (get_bit_status(orig_node->bcast_bits, orig_node->last_bcast_seqno, ntohs(bcast_packet->seqno))) { @@ -916,14 +961,20 @@ int recv_bcast_packet(struct sk_buff *skb) return NET_RX_DROP; } - /* mark broadcast in flood history */ - if (bit_get_packet(orig_node->bcast_bits, - ntohs(bcast_packet->seqno) - - orig_node->last_bcast_seqno, 1)) + seq_diff = ntohs(bcast_packet->seqno) - orig_node->last_bcast_seqno; + + /* check whether the packet is old and the host just restarted. */ + if (window_protected(seq_diff, &orig_node->bcast_seqno_reset)) { + spin_unlock_irqrestore(&orig_hash_lock, flags); + return NET_RX_DROP; + } + + /* mark broadcast in flood history, update window position + * if required. */ + if (bit_get_packet(orig_node->bcast_bits, seq_diff, 1)) orig_node->last_bcast_seqno = ntohs(bcast_packet->seqno); spin_unlock_irqrestore(&orig_hash_lock, flags); - /* rebroadcast packet */ add_bcast_packet_to_list(skb); diff --git a/drivers/staging/batman-adv/types.h b/drivers/staging/batman-adv/types.h index eba1fa62f30..c92621965b3 100644 --- a/drivers/staging/batman-adv/types.h +++ b/drivers/staging/batman-adv/types.h @@ -55,6 +55,10 @@ struct orig_node { /* structure for orig_list maintaining nodes of uint8_t tq_own; int tq_asym_penalty; unsigned long last_valid; /* when last packet from this node was received */ + unsigned long bcast_seqno_reset; /* time when the broadcast + seqno window was reset. */ + unsigned long batman_seqno_reset;/* time when the batman seqno + window was reset. */ /* uint8_t gwflags; * flags related to gateway functions: gateway class */ uint8_t flags; /* for now only VIS_SERVER flag. */ unsigned char *hna_buff; |