On Thu, Feb 16, 2012 at 10:03:54AM -0800, David Somayajulu wrote: > Hi All, > Is it safe to assume that when a driver receives an Ethernet frame to > transmit with CSUM_TSO bit set in > > m_head->m_pkthdr.csum_flags ; where m_head is the first (struct mbuf) in the > mbuf chain > > that the [Ethernet Header] + [VLAN Tag if present] + [IP Header] + [TCP > Header] are all present in one physically contiguous segment ? >
No it is not. This is the main reason why TSO capable drivers parse mbuf chain in TX path. > In other words is > > Size of ([Ethernet Header] + [VLAN Tag if present] + [IP Header] + [TCP > Header]) <= m_head->m_len > > When ((m_head->m_pkthdr.csum_flags & CSUM_TSO) != 0) > > Thanks > David S. _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
