[PATCH] Fix connect/sendto/sendmsg into making sure to ignore bytes beyond sockaddr length

[Roland McGrath]

> Thanks Tanaka Akira for the report.

General glibc policy is that if a bug was user-visible (i.e. observable in
a user program that was not itself using undefined behavior, etc.) then
there should be a bugzilla item filed for it.  That BZ# should then be
in the ChangeLog entry.

> --- /dev/null
> +++ b/hurd/hurdsocket.h

Because of its particular content and modern re-#define rules, this file
will actually work OK without a multiple inclusion guard.  But normal
practice is to have one, so please do.

> +#define _hurd_sun_path_dupa(__addr, __len) \
> +  strndupa ((__addr)->sun_path, (__len) - offsetof (struct sockaddr_un, sun_path))

Don't use __ names for macro arguments.  There's no need.  This should
really have a comment saying both what precisely it does, and where and why
it's important to use it.

Otherwise this looks fine.


Thanks,
Roland