The accept(2) man page warns that O_NONBLOCK and other properties on the
new socket may vary across implementations. However, this issue only
applies to accept() and not to accept4(). On the other hand, accept4()
is not commonly available yet.
Reported by: pluknet
Reviewed by: bjk
Approved by: re (kib)
The accept4() function, compared to accept(), allows setting the new file
descriptor atomically close-on-exec and explicitly controlling the
non-blocking status on the new socket. (Note that the latter point means
that accept() is not equivalent to any form of accept4().)
The linuxulator's accept4 implementation leaves a race window where the new
file descriptor is not close-on-exec because it calls sys_accept(). This
implementation leaves no such race window (by using falloc() flags). The
linuxulator could be fixed and simplified by using the new code.
Like accept(), accept4() is async-signal-safe, a cancellation point and
permitted in capability mode.
While almost nobody uses O_ASYNC, and rightly so, the inheritance of the
related properties across accept() is a portability issue like the
inheritance of O_NONBLOCK.
negative (in addition to returning EINVAL when called on a descriptor
that is not a socket).
Submitted by: Arne H Juul <arnej@europe.yahoo-inc.com>
PR: docs/80587
no peer address information is desired.
PR: 56044
Submitted by: Felix Opatz <felix@zotteljedi.de> and
Bernd Luevelsmeyer <bdluevel@heitec.net>
MFC after: 1 month
Stop calling system calls "function calls".
Use "The .Fn system call" a-la "The .Nm utility".
When referring to a non-BSD implementation in
the HISTORY section, call syscall a function,
to be safe.
data without confirming the connection by issuing a recvmsg(2) [...]".
There's no such code in the kernel.
PR: 26861
Submitted by: Richard A Steenbergen <ras@e-gerbil.net>,
Tom Rhodes <darklogik@pittgoth.com>
with NetBSD and the Single Unix Specification v2.
This updates some structures with other, almost equivalent types and
effort is under way to get the whole more consistent.
Also removes a double definition of INET6 and some other clean-ups.
Reviewed by: green, bde, phk
Some part obtained from: NetBSD, SUSv2 specification
