sbspace() / sbappendaddr() problem

[VANHULLEBUS Yvan]

Hi all.


I have some reccurent problems with PFKey interafce for a while, whith
ENOBUFS errors.

While tracking down the problem, I found that a test goes wrong in
sbappendaddr(), in kern_uipc_socket2.c, because the "space" variable
(an int) gets "bigger" than the result of sbspace(sb), which shlould
not happen.

After having a deeper look at sbspace() macro, I noticed that there
are some potential cast/sign problems with this macro (this is
specified in the comments of the macro).

So I wrote a new version of the macro, which should avoir all
problems:

#define	sbspace(sb) \
 (ulmin( ( (sb)->sb_hiwat > (sb)->sb_cc ? (sb)->sb_hiwat - (sb)->sb_cc : 0), \
 (sb)->sb_mbmax > (sb)->sb_mbcnt ? (sb)->sb_mbmax - (sb)->sb_mbcnt : 0)))

Then I set up the type of "space" variable in sbappendaddr() as
u_long, and I have no more problems for now.

But as this function and this macro are used on some other parts of
the kernel, I don't know if I solved all problems, or if I generated
new problems elsewhere while solving one.

Does someone have any comments on this new sbspace() ?



Yvan.

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