Re: [B.A.T.M.A.N.] [PATCH 07/19] batman-adv: Prepare and send own multicast tracker packets

Hello,

found one more thing which will break packet sending, please see inline:

On Sat, Jan 22, 2011 at 02:21:30AM +0100, Linus Lüssing wrote:

[...] +/**

• • Sends (splitted parts of) a multicast tracker packet on the according
• • interfaces.
• • @tracker_packet: A compact multicast tracker packet with all groups and

• • 	destinations attached.
    

• */

+void route_mcast_tracker_packet(

• 	struct mcast_tracker_packet *tracker_packet,
  

• 	int tracker_packet_len, struct bat_priv *bat_priv)
  

+{

• struct dest_entries_list next_hops, *tmp;
• struct mcast_tracker_packet *next_hop_tracker_packets,

• 		    *next_hop_tracker_packet;
  

• struct dest_entries_list *next_hop;
• struct sk_buff *skb;
• int num_next_hops, i;
• int *tracker_packet_lengths;
• rcu_read_lock();
• num_next_hops = tracker_next_hops(tracker_packet, &next_hops,

• 			  bat_priv);
  

• if (!num_next_hops)

• goto out;
  

• next_hop_tracker_packets = kmalloc(tracker_packet_len * num_next_hops,

• 			   GFP_ATOMIC);
  

• if (!next_hop_tracker_packets)

• goto free;
  

• tracker_packet_lengths = kmalloc(num_next_hops * sizeof(int),

• 			  GFP_ATOMIC);
  

• if (!tracker_packet_lengths)

• goto free2;
  

• i = 0;
• list_for_each_entry_safe(next_hop, tmp, &next_hops.list, list) {

• next_hop_tracker_packet = (struct mcast_tracker_packet *)
  

• 			  ((char *)next_hop_tracker_packets +
  

• 			   i * tracker_packet_len);
  

• memcpy(next_hop_tracker_packet, tracker_packet,
  

•        tracker_packet_len);
  

• zero_tracker_packet(next_hop_tracker_packet, next_hop->dest,
  

• 		    bat_priv);
  

• tracker_packet_lengths[i] = shrink_tracker_packet(
  

• 		next_hop_tracker_packet, tracker_packet_len);
  

• i++;
  

• }
• i = 0;
• /* Add ethernet header, send 'em! */
• list_for_each_entry_safe(next_hop, tmp, &next_hops.list, list) {

• if (tracker_packet_lengths[i] ==
  

•     sizeof(struct mcast_tracker_packet))
  

• 	goto skip_send;
  

• skb = build_tracker_packet_skb(&next_hop_tracker_packets[i],
  

Don't use next_hop_tracker_packets[i]! This will give you a wrong pointer, because the base is "sizeof(struct mcast_tracker_packet)" and not "tracker_packet_len". Instead, please use a "next_hop_tracker_packet" construct like in the loop above.

(BTW, i think you could merge the two loops and skip the array "tracker_packet_lengths" for keeping the lengths, i think ...)

• 			       tracker_packet_lengths[i],
  

• 			       next_hop->dest);
  

• if (skb)
  

• 	send_skb_packet(skb, next_hop->batman_if,
  

• 			next_hop->dest);
  

+skip_send:

• list_del(&next_hop->list);
  

• kfree(next_hop);
  

• i++;
  

• }