Probable Bug in tcp.h

[Bruce M. Simpson]

Marc Lörner wrote:
> ..
> First of all I have the problam of misalignment of th_off. Because in this way 
> always 4 bytes are read and the the bits of th_off are replaced. Then the 4 
> bytes are written back. 
>
> But should (th_x and th_off) not only be 1 byte in whole -> only read and 
> write 1 byte?
>   

Which machine architecture are you attempting to compile this code on?

On FreeBSD Tier 1 platforms, the access is probably going to come out of 
L2 cache anyway, so the fields in question will be read by a burst cycle.

It is worth noting that NetBSD changed the base type of tcphdr's 
bitfields to uint8_t, however this shuffles the compiler dependency into 
the treatment of the "char" type. Most modern C compilers support 
"unsigned char".