From: Pascal Hambourg Date: Wed, 17 Aug 2011 08:37:18 +0200 Subject: [PATCH 1/2] atm: br2684: Make headroom and hard_header_len depend on the payload type Routed payload requires less headroom than bridged payload. So do not reallocate headroom if not needed. Also, add worst case AAL5 overhead to netdev->hard_header_len. Signed-off-by: Pascal Hambourg Signed-off-by: chas williams - CONTRACTOR --- net/atm/br2684.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/net/atm/br2684.c b/net/atm/br2684.c index 53b0aa1..ed72263 100644 --- a/net/atm/br2684.c +++ b/net/atm/br2684.c @@ -202,7 +202,10 @@ static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev, { struct br2684_dev *brdev = BRPRIV(dev); struct atm_vcc *atmvcc; - int minheadroom = (brvcc->encaps == e_llc) ? 10 : 2; + int minheadroom = (brvcc->encaps == e_llc) ? + ((brdev->payload == p_bridged) ? + sizeof(llc_oui_pid_pad) : sizeof(llc_oui_ipv4)) : + ((brdev->payload == p_bridged) ? BR2684_PAD_LEN : 0); if (skb_headroom(skb) < minheadroom) { struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom); @@ -583,6 +586,7 @@ static void br2684_setup(struct net_device *netdev) struct br2684_dev *brdev = BRPRIV(netdev); ether_setup(netdev); + netdev->hard_header_len += sizeof(llc_oui_pid_pad); /* worst case */ brdev->net_dev = netdev; netdev->netdev_ops = &br2684_netdev_ops; @@ -595,7 +599,7 @@ static void br2684_setup_routed(struct net_device *netdev) struct br2684_dev *brdev = BRPRIV(netdev); brdev->net_dev = netdev; - netdev->hard_header_len = 0; + netdev->hard_header_len = sizeof(llc_oui_ipv4); /* worst case */ netdev->netdev_ops = &br2684_netdev_ops_routed; netdev->addr_len = 0; netdev->mtu = 1500; From: Pascal Hambourg Date: Wed, 17 Aug 2011 08:37:52 +0200 Subject: [PATCH 2/2] atm: br2684: Avoid alignment issues Use memcmp() instead of cast to u16 when checking the PAD field. Signed-off-by: Pascal Hambourg Signed-off-by: chas williams - CONTRACTOR --- net/atm/br2684.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/net/atm/br2684.c b/net/atm/br2684.c index ed72263..353fccf 100644 --- a/net/atm/br2684.c +++ b/net/atm/br2684.c @@ -53,6 +53,7 @@ static const unsigned char ethertype_ipv4[] = { ETHERTYPE_IPV4 }; static const unsigned char ethertype_ipv6[] = { ETHERTYPE_IPV6 }; static const unsigned char llc_oui_pid_pad[] = { LLC, SNAP_BRIDGED, PID_ETHERNET, PAD_BRIDGED }; +static const unsigned char pad[] = { PAD_BRIDGED }; static const unsigned char llc_oui_ipv4[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV4 }; static const unsigned char llc_oui_ipv6[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV6 }; @@ -453,7 +454,7 @@ static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb) skb->pkt_type = PACKET_HOST; } else { /* p_bridged */ /* first 2 chars should be 0 */ - if (*((u16 *) (skb->data)) != 0) + if (memcmp(skb->data, pad, BR2684_PAD_LEN) != 0) goto error; skb_pull(skb, BR2684_PAD_LEN); skb->protocol = eth_type_trans(skb, net_dev);