Re: CMSG bugs

On 10/09/2011 08:48 PM, Amos Jeffries wrote:
> We are hitting bugs in CMSG_* macros on several systems (Windows,
> NetBSD, MacOS, and likely their derivatives).

I would like to help with these but bugzilla search for CMSG turned out
nothing for me. Could you point me to specific bug reports we need to
address?

> I've found a discussion from Feb (this year!) which seems to explain
> some of the build problems reported recently.
> http://mail-index.netbsd.org/tech-userlevel/2011/02/24/msg004623.html
> http://mail-index.netbsd.org/tech-userlevel/2011/02/24/msg004626.html

I cannot say I understand everything those folks say, but it looks like
we may want to do what scm-rights.h does.

> Does anyone know of an alternative for passing the SMP packets data around?

IIRC, CMSG macros are needed to pass file descriptors only but passing
descriptors was one of the primary reason for using UDS.

For passing file descriptors on Unix, I know of three choices:

1. Use threads instead of processes.
2. Use UDS and CMSG stuff.
3. Use STREAMS and ioctl stuff.

Given the above choice, and all the pros and cons of each option, I
still think we made the right decision to go with UDS.

> It looks like we may be headed down the same road that scm-rights.h rant
> was all about.

Agreed. While it sounds like there is a big API problem there, their
solution seems simple enough, although I do not know how they set
NEW_CMSG_INTERFACE.

Cheers,

Alex.
Received on Mon Oct 10 2011 - 15:52:11 MDT