From: Michael S. Tsirkin Date: Wed, 21 Mar 2007 13:45:05 +0000 (+0200) Subject: IB/ipoib: Fix thinko in packet length checks X-Git-Tag: v2.6.21-rc5~46^2 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=77d8e1efea0e313edc710160c232a6fd2dc9f907;p=linux-2.6 IB/ipoib: Fix thinko in packet length checks The packet length checks in ipoib are broken: we add 4 bytes (IPoIB encapsulation header) when sending a packet, not 20 bytes (hardware address length) to each packet. Therefore, if connected mode is enabled so that the interface MTU is larger than the multicast MTU, IPoIB may end up trying to send too-long multicast packets. For example, multicast is broken if a message of size 2048 bytes is sent on an interface with UD MTU 2048, because 2048 is bigger than the real limit of 2044 but the code tests against the wrong limit of 2060. This patch fixes , submitted by Scott Weitzenkamp . Signed-off-by: Michael S. Tsirkin Signed-off-by: Roland Dreier --- diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c index 467564074e..e70492db74 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c @@ -452,7 +452,7 @@ void ipoib_cm_send(struct net_device *dev, struct sk_buff *skb, struct ipoib_cm_ skb->len, tx->mtu); ++priv->stats.tx_dropped; ++priv->stats.tx_errors; - ipoib_cm_skb_too_long(dev, skb, tx->mtu - INFINIBAND_ALEN); + ipoib_cm_skb_too_long(dev, skb, tx->mtu - IPOIB_ENCAP_LEN); return; } diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c index f2aa923ddb..ba0ee5cf2a 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c @@ -328,9 +328,9 @@ void ipoib_send(struct net_device *dev, struct sk_buff *skb, struct ipoib_tx_buf *tx_req; u64 addr; - if (unlikely(skb->len > priv->mcast_mtu + INFINIBAND_ALEN)) { + if (unlikely(skb->len > priv->mcast_mtu + IPOIB_ENCAP_LEN)) { ipoib_warn(priv, "packet len %d (> %d) too long to send, dropping\n", - skb->len, priv->mcast_mtu + INFINIBAND_ALEN); + skb->len, priv->mcast_mtu + IPOIB_ENCAP_LEN); ++priv->stats.tx_dropped; ++priv->stats.tx_errors; ipoib_cm_skb_too_long(dev, skb, priv->mcast_mtu);