That one is tricky, yes :) Thomas Huth, on Wed 10 Feb 2016 09:05:32 +0100, wrote: > > -#define SLIRP_MSIZE (IF_MTU + IF_MAXLINKHDR + offsetof(struct mbuf, m_dat) > > + 6) > > +#define SLIRP_MSIZE\ > > + (offsetof(struct mbuf, m_dat) + IF_MAXLINKHDR + TCPIPHDR_DELTA + > > IF_MTU) > > I'm somehow having a hard time to understand why TCPIPHDR_DELTA is used > here. As far as I understand, TCPIPHDR_DELTA is the difference between > the size of struct tcpiphdr and the size of the IPv4 + TCP header. But > if it's just the difference, where does the base size of the headers > come from in this define, since the headers are stored in the mbuf, too, > aren't they? ... I've got the feeling that I miss something here, could > you enlighten me?
TCP/IP headers are within IF_MTU. Samuel