Re: [B.A.T.M.A.N.] [RFC 6/6] batman-adv: Adds snooping of router and override flags for NA creation

From: Mihail Costea <mihail.costea90(a)gmail.com> Snoops router and override flags for Neighbor Advertisement in order to use it in NA creation. This information is stored in a extra member in the dat entry. This is done separately from normal data, because data is used for DHT comparison, while this flags can change their value over time.

Comments: For now router and override are initialized to the values used in most case scenarios. This can be changed easily if we want to avoid the NA creation until we get the flags.

Also, the router flag can be calculated easily using the Router Advertisement. Any node that sends that package is a router, so there isn't a lot of snooping in that case. This feature can be added easily. The problem is that I have no other idea how to get the override flag, with the exception of the current implemented mechanism. Signed-off-by: Mihail Costea <mihail.costea90(a)gmail.com> Signed-off-by: Stefan Popa <Stefan.A.Popa(a)intel.com> Reviewed-by: Stefan Popa <Stefan.A.Popa(a)intel.com> --- distributed-arp-table.c | 139 +++++++++++++++++++++++++++++++++++------------ types.h | 21 ++++++- 2 files changed, 124 insertions(+), 36 deletions(-) diff --git a/distributed-arp-table.c b/distributed-arp-table.c index 1a5749b..ce5c13d 100644 --- a/distributed-arp-table.c +++ b/distributed-arp-table.c @@ -39,7 +39,8 @@ static bool batadv_dat_snoop_arp_pkt(struct batadv_priv *bat_priv, struct sk_buff *skb, int hdr_size, uint16_t pkt_type, uint8_t pkt_dir_type, uint8_t **hw_src, void **ip_src, - uint8_t **hw_dst, void **ip_dst); + uint8_t **hw_dst, void **ip_dst, + void **extra_data); static struct sk_buff * batadv_dat_create_arp_reply(struct batadv_priv *bat_priv, @@ -56,7 +57,8 @@ static bool batadv_dat_snoop_ndisc_pkt(struct batadv_priv *bat_priv, struct sk_buff *skb, int hdr_size, uint16_t pkt_type, uint8_t pkt_dir_type, uint8_t **hw_src, void **ip_src, - uint8_t **hw_dst, void **ip_dst); + uint8_t **hw_dst, void **ip_dst, + void **extra_data); static struct sk_buff * batadv_dat_create_ndisc_na(struct batadv_priv *bat_priv, @@ -68,6 +70,7 @@ batadv_dat_create_ndisc_na(struct batadv_priv *bat_priv, static struct batadv_dat_type_info batadv_dat_types_info[] = { { .size = sizeof(__be32), + .extra_size = 0, .str_fmt = "%pI4", .snoop_pkt = batadv_dat_snoop_arp_pkt, .create_skb = batadv_dat_create_arp_reply, @@ -75,6 +78,7 @@ static struct batadv_dat_type_info batadv_dat_types_info[] = { #if IS_ENABLED(CONFIG_IPV6) { .size = sizeof(struct in6_addr), + .extra_size = sizeof(struct batadv_dat_ipv6_extra_data), .str_fmt = "%pI6c", .snoop_pkt = batadv_dat_snoop_ndisc_pkt, .create_skb = batadv_dat_create_ndisc_na, @@ -119,6 +123,7 @@ static void batadv_dat_entry_free_ref_rcu(struct rcu_head *rcu) dat_entry = container_of(rcu, struct batadv_dat_entry, rcu); kfree(dat_entry->data); + kfree(dat_entry->extra_data); kfree(dat_entry); } @@ -363,18 +368,20 @@ batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, void *data, * batadv_dat_entry_add - add a new dat entry or update it if already exists * @bat_priv: the bat priv with all the soft interface information * @data: the data to add/edit + * @extra_data: the extra data for data param (can be NULL if none) * @data_type: type of the data added to DAT * @mac_addr: mac address to assign to the given data * @vid: VLAN identifier */ static void batadv_dat_entry_add(struct batadv_priv *bat_priv, void *data, - uint8_t data_type, uint8_t *mac_addr, - unsigned short vid) + void *extra_data, uint8_t data_type, + uint8_t *mac_addr, unsigned short vid) { struct batadv_dat_entry *dat_entry; int hash_added; char dbg_data[BATADV_DAT_DATA_MAX_LEN]; size_t data_size = batadv_dat_types_info[data_type].size; + size_t extra_data_size = batadv_dat_types_info[data_type].extra_size; dat_entry = batadv_dat_entry_hash_find(bat_priv, data, data_type, vid); /* if this entry is already known, just update it */ @@ -382,22 +389,40 @@ static void batadv_dat_entry_add(struct batadv_priv *bat_priv, void *data, if (!batadv_compare_eth(dat_entry->mac_addr, mac_addr)) memcpy(dat_entry->mac_addr, mac_addr, ETH_ALEN); dat_entry->last_update = jiffies; - batadv_dbg(BATADV_DBG_DAT, bat_priv, "Entry updated: %s %pM (vid: %u)\n", + if (extra_data) + memcpy(dat_entry->extra_data, extra_data, + extra_data_size); + + batadv_dbg(BATADV_DBG_DAT, bat_priv, + "Entry updated: %s %pM (vid: %u)\n", batadv_dat_data_to_str(dat_entry->data, data_type, dbg_data, sizeof(dbg_data)), dat_entry->mac_addr, vid); goto out; } + /* alloc entry */ dat_entry = kmalloc(sizeof(*dat_entry), GFP_ATOMIC); if (!dat_entry) goto out; + /* some entries don't have an extra data and useful if allocation for + * data fails */