From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH 2/2] ehea: Receive SKB Aggregation Date: Thu, 31 May 2007 09:37:03 -0700 Message-ID: <20070531093703.373995b2@freepuppy> References: <200705311354.56979.osstklei@de.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Jeff Garzik , Christoph Raisch , "Jan-Bernd Themann" , "Jan-Bernd Themann" , "linux-kernel" , "linux-ppc" , Marcus Eder , netdev , Thomas Klein , Stefan Roscher To: Thomas Klein Return-path: Received: from smtp.osdl.org ([207.189.120.12]:45192 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760599AbXEaQsk (ORCPT ); Thu, 31 May 2007 12:48:40 -0400 In-Reply-To: <200705311354.56979.osstklei@de.ibm.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org > > > +static int try_get_ip_tcp_hdr(struct ehea_cqe *cqe, struct sk_buff *skb, > + struct iphdr **iph, struct tcphdr **tcph) > +{ > + int ip_len; > + > + /* non tcp/udp packets */ > + if (!cqe->header_length) > + return -1; > + > + /* non tcp packet */ > + *iph = (struct iphdr *)(skb->data); Why the indirection, copying of headers.. > + if ((*iph)->protocol != IPPROTO_TCP) > + return -1; > + > + ip_len = (u8)((*iph)->ihl); > + ip_len <<= 2; > + *tcph = (struct tcphdr *)(((u64)*iph) + ip_len); > + > + return 0; > +} > + > This code seems to be duplicating a lot (but not all) of the TCP/IP input path validation checks. This is a security problem if nothing else... Also, how do you prevent DoS attacks from hostile TCP senders that send huge number of back to back frames? -- Stephen Hemminger