Re: [9fans] 9P2000

[Mike Haertel <mike@ducky.net>]

>there's one case where the client has to be a bit careful about the
>size of messages it generates. a Twalk message can itself fit inside
>the negotiated msize, but require an Rwalk that will not do so. (e.g.
>walking down several short pathname elements).  it might be worth
>requiring a minimum message size of 1+4+2+2+MAXWELEM*13 = 217 which
>would avoid this problem.

This is not nearly as bad as the directory entry situation.  A
client that specified a very small mside could be held responsible
for not producing Twalks whose corresponding Rwalks would exceed
the msize; this would be under control of the client and so is
an avoidable situation.

But the client has no control whatever over the size of a directory
entry it is about to read.  It is helpless.