Author: marek Date: 2010-08-08 15:00:58 +0200 (Sun, 08 Aug 2010) New Revision: 1761
Modified: trunk/batman-adv/routing.c Log: batman-adv: Create copy of skb with pre-allocated headroom
We can use skb_cow instead of a handwritten function to test and create a writable skb buffer. This also allows us to pre-allocate headroom to be able to send the data without re-allocating the buffer again to add the ethernet header.
Signed-off-by: Sven Eckelmann sven.eckelmann@gmx.de
Modified: trunk/batman-adv/routing.c =================================================================== --- trunk/batman-adv/routing.c 2010-08-08 13:00:54 UTC (rev 1760) +++ trunk/batman-adv/routing.c 2010-08-08 13:00:58 UTC (rev 1761) @@ -754,7 +754,6 @@ { struct ethhdr *ethhdr; unsigned long flags; - struct sk_buff *skb_old;
/* drop packet if it has not necessary minimum size */ if (skb_headlen(skb) < sizeof(struct batman_packet)) @@ -770,19 +769,12 @@ if (is_bcast(ethhdr->h_source)) return NET_RX_DROP;
- /* TODO: we use headlen instead of "length", because - * only this data is paged in. */ - /* create a copy of the skb, if needed, to modify it. */ - if (!skb_clone_writable(skb, skb_headlen(skb))) { - skb_old = skb; - skb = skb_copy(skb, GFP_ATOMIC); - if (!skb) - return NET_RX_DROP; - ethhdr = (struct ethhdr *)skb_mac_header(skb); - kfree_skb(skb_old); - } + if (skb_cow(skb, 0) < 0) + return NET_RX_DROP;
+ ethhdr = (struct ethhdr *)skb_mac_header(skb); + spin_lock_irqsave(&orig_hash_lock, flags); receive_aggr_bat_packet(ethhdr, skb->data, @@ -801,7 +793,6 @@ struct orig_node *orig_node; struct icmp_packet_rr *icmp_packet; struct ethhdr *ethhdr; - struct sk_buff *skb_old; struct batman_if *batman_if; int ret; unsigned long flags; @@ -836,17 +827,12 @@ spin_unlock_irqrestore(&orig_hash_lock, flags);
/* create a copy of the skb, if needed, to modify it. */ - skb_old = NULL; - if (!skb_clone_writable(skb, icmp_len)) { - skb_old = skb; - skb = skb_copy(skb, GFP_ATOMIC); - if (!skb) - return NET_RX_DROP; - icmp_packet = (struct icmp_packet_rr *)skb->data; - ethhdr = (struct ethhdr *)skb_mac_header(skb); - kfree_skb(skb_old); - } + if (skb_cow(skb, sizeof(struct ethhdr)) < 0) + return NET_RX_DROP;
+ icmp_packet = (struct icmp_packet_rr *)skb->data; + ethhdr = (struct ethhdr *)skb_mac_header(skb); + memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN); memcpy(icmp_packet->orig, bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN); @@ -869,7 +855,6 @@ struct orig_node *orig_node; struct icmp_packet *icmp_packet; struct ethhdr *ethhdr; - struct sk_buff *skb_old; struct batman_if *batman_if; int ret; unsigned long flags; @@ -905,16 +890,12 @@ spin_unlock_irqrestore(&orig_hash_lock, flags);
/* create a copy of the skb, if needed, to modify it. */ - if (!skb_clone_writable(skb, icmp_len)) { - skb_old = skb; - skb = skb_copy(skb, GFP_ATOMIC); - if (!skb) - return NET_RX_DROP; - icmp_packet = (struct icmp_packet *) skb->data; - ethhdr = (struct ethhdr *)skb_mac_header(skb); - kfree_skb(skb_old); - } + if (skb_cow(skb, sizeof(struct ethhdr)) < 0) + return NET_RX_DROP;
+ icmp_packet = (struct icmp_packet *) skb->data; + ethhdr = (struct ethhdr *)skb_mac_header(skb); + memcpy(icmp_packet->dst, icmp_packet->orig, ETH_ALEN); memcpy(icmp_packet->orig, bat_priv->primary_if->net_dev->dev_addr, ETH_ALEN); @@ -936,7 +917,6 @@ struct icmp_packet_rr *icmp_packet; struct ethhdr *ethhdr; struct orig_node *orig_node; - struct sk_buff *skb_old; struct batman_if *batman_if; int hdr_size = sizeof(struct icmp_packet); int ret; @@ -1002,16 +982,12 @@ spin_unlock_irqrestore(&orig_hash_lock, flags);
/* create a copy of the skb, if needed, to modify it. */ - if (!skb_clone_writable(skb, hdr_size)) { - skb_old = skb; - skb = skb_copy(skb, GFP_ATOMIC); - if (!skb) - return NET_RX_DROP; - icmp_packet = (struct icmp_packet_rr *)skb->data; - ethhdr = (struct ethhdr *)skb_mac_header(skb); - kfree_skb(skb_old); - } + if (skb_cow(skb, sizeof(struct ethhdr)) < 0) + return NET_RX_DROP;
+ icmp_packet = (struct icmp_packet_rr *)skb->data; + ethhdr = (struct ethhdr *)skb_mac_header(skb); + /* decrement ttl */ icmp_packet->ttl--;
@@ -1149,7 +1125,6 @@ struct orig_node *orig_node; struct neigh_node *router; struct batman_if *batman_if; - struct sk_buff *skb_old; uint8_t dstaddr[ETH_ALEN]; unsigned long flags; struct unicast_packet *unicast_packet = @@ -1185,16 +1160,12 @@ spin_unlock_irqrestore(&orig_hash_lock, flags);
/* create a copy of the skb, if needed, to modify it. */ - if (!skb_clone_writable(skb, hdr_size)) { - skb_old = skb; - skb = skb_copy(skb, GFP_ATOMIC); - if (!skb) - return NET_RX_DROP; - unicast_packet = (struct unicast_packet *) skb->data; - ethhdr = (struct ethhdr *)skb_mac_header(skb); - kfree_skb(skb_old); - } + if (skb_cow(skb, sizeof(struct ethhdr)) < 0) + return NET_RX_DROP;
+ unicast_packet = (struct unicast_packet *) skb->data; + ethhdr = (struct ethhdr *)skb_mac_header(skb); + /* decrement ttl */ unicast_packet->ttl--;