From 83bdd3b96cad1b0c5b8e257ed1f4f38eb2cb844b Mon Sep 17 00:00:00 2001 From: Doug Ledford Date: Mon, 1 Apr 2013 21:25:30 +0000 Subject: [PATCH] IPoIB: Fix ipoib_hard_header() return value If you have a patched up dhcp server (and dhclient), they will use AF_PACKET/SOCK_DGRAM pair to send dhcp packets over IPoIB. However, when testing an upstream kernel, this has been broken for a very long time (I tested 2.6.34, 2.6.38, 3.0, 3.1, 3.8, HEAD). It turns out that the hard_header routine in ipoib is not following the API and is returning 0 even when it pushed data onto the skb. This then causes af_packet.c to overwrite the header just pushed with data from user space. Fixing this gets DHCP working on IPoIB. Signed-off-by: Doug Ledford Signed-off-by: Roland Dreier --- drivers/infiniband/ulp/ipoib/ipoib_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c index 8534afd..31dd2a7 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_main.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c @@ -828,7 +828,7 @@ static int ipoib_hard_header(struct sk_buff *skb, */ memcpy(cb->hwaddr, daddr, INFINIBAND_ALEN); - return 0; + return sizeof *header; } static void ipoib_set_mcast_list(struct net_device *dev) -- 2.7.4