The send functions in batman-adv are expected to consume the skb when either the data is queued up for the underlying driver or when some precondition failed. batadv_dat_send_data didn't do this and instead created a copy of the skb, modified it and queued the copy up for transmission. The caller has to take care that the skb is handled correctly (for example free'd) when batadv_dat_send_data returns.
This unclear behavior already lead to memory leaks in the recent past. Renaming the function to batadv_dat_forward_data should make it easier to identify that the data is forwarded but the skb is not actually send+consumed.
Signed-off-by: Sven Eckelmann sven@narfation.org --- Cc: Linus Lüssing linus.luessing@c0d3.blue
Do you think that would have helped when you've implemented the DAT change? --- net/batman-adv/distributed-arp-table.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-)
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 310a4f35..b6bad3f6 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -667,7 +667,7 @@ batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst, }
/** - * batadv_dat_send_data() - send a payload to the selected candidates + * batadv_dat_forward_data() - copy and send payload to the selected candidates * @bat_priv: the bat priv with all the soft interface information * @skb: payload to send * @ip: the DHT key @@ -680,9 +680,9 @@ batadv_dat_select_candidates(struct batadv_priv *bat_priv, __be32 ip_dst, * Return: true if the packet is sent to at least one candidate, false * otherwise. */ -static bool batadv_dat_send_data(struct batadv_priv *bat_priv, - struct sk_buff *skb, __be32 ip, - unsigned short vid, int packet_subtype) +static bool batadv_dat_forward_data(struct batadv_priv *bat_priv, + struct sk_buff *skb, __be32 ip, + unsigned short vid, int packet_subtype) { int i; bool ret = false; @@ -1277,8 +1277,8 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, ret = true; } else { /* Send the request to the DHT */ - ret = batadv_dat_send_data(bat_priv, skb, ip_dst, vid, - BATADV_P_DAT_DHT_GET); + ret = batadv_dat_forward_data(bat_priv, skb, ip_dst, vid, + BATADV_P_DAT_DHT_GET); } out: if (dat_entry) @@ -1392,8 +1392,10 @@ void batadv_dat_snoop_outgoing_arp_reply(struct batadv_priv *bat_priv, /* Send the ARP reply to the candidates for both the IP addresses that * the node obtained from the ARP reply */ - batadv_dat_send_data(bat_priv, skb, ip_src, vid, BATADV_P_DAT_DHT_PUT); - batadv_dat_send_data(bat_priv, skb, ip_dst, vid, BATADV_P_DAT_DHT_PUT); + batadv_dat_forward_data(bat_priv, skb, ip_src, vid, + BATADV_P_DAT_DHT_PUT); + batadv_dat_forward_data(bat_priv, skb, ip_dst, vid, + BATADV_P_DAT_DHT_PUT); }
/** @@ -1708,8 +1710,10 @@ static void batadv_dat_put_dhcp(struct batadv_priv *bat_priv, u8 *chaddr, batadv_dat_entry_add(bat_priv, yiaddr, chaddr, vid); batadv_dat_entry_add(bat_priv, ip_dst, hw_dst, vid);
- batadv_dat_send_data(bat_priv, skb, yiaddr, vid, BATADV_P_DAT_DHT_PUT); - batadv_dat_send_data(bat_priv, skb, ip_dst, vid, BATADV_P_DAT_DHT_PUT); + batadv_dat_forward_data(bat_priv, skb, yiaddr, vid, + BATADV_P_DAT_DHT_PUT); + batadv_dat_forward_data(bat_priv, skb, ip_dst, vid, + BATADV_P_DAT_DHT_PUT);
consume_skb(skb);