Published Vol 1 Chapter 16 (Networking) for free

[morpheus]

The complete bonus chapter of #MOXiI2 #Vol1: #MacOS/*OS #Networking:

Discusses PF_NDRV/PF_SYSTEM sockets,BPF, PF, ntstat,NECP, net agents, rvi, Skywalk & more, most previously undocumented!



http://newosxbook.com/bonus/vol1ch16.html

[Siguza]

Looks great! Haven't found the time to read it yet, but it seems a few image links are broken:

Screen Shot 2019-01-03 at 14.49.01.png (38.48 KiB) Viewed 3660 times

J Says: Thanks, but there are just small icons in the book, which I didn't copy into the HTML subdirectories. Nothing major.

[b3ntx]

really solid chapter. thanks J.

I do have a question about the some of the BPF opcodes. You mentioned that the BPF_ST[X] codes could alter the frame memory. Could you elaborate on that? I've dug through the source of bpf_filter() the only writes of user data I could find (besides X and A) were to the scratch memory. I couldn't see anything that could alter the packet data. or am I misinterpreting 'frame memory'?

J says: You understood correctly. That 'frame' wasn't meant to be there (fixed in the HTML). I did mean scratch memory, which is in kernel space. Hence the observation about potential danger