On Tue, Oct 30, 2018 at 07:13:24AM +0000, Jason McIntyre wrote:
> On Mon, Oct 29, 2018 at 11:55:52PM +0100, Jan Klemkow wrote:
> > On Sun, Oct 28, 2018 at 10:58:34PM +0000, Jason McIntyre wrote:
> > > On Sun, Oct 28, 2018 at 09:40:33PM +0100, Jan Klemkow wrote:
> > > > Unlike the manpage saids or one might think , sendto(2) sets errno to
> > > > EHOSTUNREACH instead of EACCES in cases of blocking by pf(4) or not
> > > > enabled broadcasts. Finally I ran into both cases and think, its time
> > > > to fix this issue. The diff suggests a new explanation that should
> > > > cover all error cases.
> > > >
> > > > Index: /usr/src/lib/libc/sys/send.2
> > > > ===================================================================
> > > > RCS file: /cvs/src/lib/libc/sys/send.2,v
> > > > retrieving revision 1.32
> > > > diff -u -p -r1.32 send.2
> > > > --- /usr/src/lib/libc/sys/send.2 5 Oct 2017 12:30:16 -0000
> > > > 1.32
> > > > +++ /usr/src/lib/libc/sys/send.2 28 Oct 2018 20:16:20 -0000
> > > > @@ -161,13 +161,13 @@ The operation may succeed when buffers b
> > > > The output queue for a network interface was full.
> > > > This generally indicates that the interface has stopped sending,
> > > > but may be caused by transient congestion.
> > > > -.It Bq Er EACCES
> > > > -The
> > > > -.Dv SO_BROADCAST
> > > > -option is not set on the socket, and a broadcast address
> > > > -was given as the destination.
> > > > .It Bq Er EHOSTUNREACH
> > > > -The destination address specified an unreachable host.
> > > > +The destination address specified an host that is unreachable,
> > >
> > > unless you're going for humour, "a host" rather than "an host".
> > >
> > > i can;t comment on the accuracy, but the rest of the diff reads ok.
> >
> > No humour (here in Germany), just a spelling mistakes :-)
> > Fixed version below.
>
> morning.
>
> to be fair, some people do still unambiguously use "an" before h* words.
> so as such it is not wrong (i think). still, our pages do not use that format.
>
> anyway, enough of the small stuff. who wants to review this page and
> actually ok or nok it?
Hi,
I printed the code path below to make it easier to review the diff.
While I was following the code path again, I found an inconsistency
between udp_output() and upd6_output(). Just upd_output() turns EACCES
to EHOSTUNREACH, udp6_output does not. The Diff below fixes udp6_output
and rounds up the sendto(2) manpage.
Bye,
Jan
Reviewer guide from sendto(2) to EHOSTUNREACH:
sys_sendto() -> sendit() -> sosend() ---+
|
+--------------------------------------+
|
+-> udp_usrreq() -> udp_output():
| ...
| error = ip_output(m, inp->inp_options, &inp->inp_route,
| (inp->inp_socket->so_options & SO_BROADCAST), inp->inp_moptions,
| inp, ipsecflowinfo);
| if (error == EACCES) /* translate pf(4) error for userland */
| error = EHOSTUNREACH;
| ...
|
+-> udp_usrreq() -> udp6_output():
| ...
| error = ip6_output(m, optp, &in6p->inp_route6,
| flags, in6p->inp_moptions6, in6p);
| if (error == EACCES) /* translate pf(4) error for userland */
| error = EHOSTUNREACH;
| ...
|
+-> tcp_usrreq() -> tcp_output():
...
error = ip_output(m, tp->t_inpcb->inp_options,
tp->t_inpcb->inp_route,
ip_mtudisc ? IP_MTUDISC : 0), NULL, tp->t_inpcb, 0);
...
error = ip6_output(m, tp->t_inpcb->inp_outputopts6,
&tp->t_inpcb->inp_route6,
0, NULL, tp->t_inpcb);
...
if (error == EACCES) /* translate pf(4) error for userland */
error = EHOSTUNREACH;
...
Index: sys/netinet6/udp6_output.c
===================================================================
RCS file: /cvs/src/sys/netinet6/udp6_output.c,v
retrieving revision 1.56
diff -u -p -r1.56 udp6_output.c
--- sys/netinet6/udp6_output.c 13 Sep 2018 19:53:58 -0000 1.56
+++ sys/netinet6/udp6_output.c 9 Nov 2018 16:31:21 -0000
@@ -235,6 +235,8 @@ udp6_output(struct inpcb *in6p, struct m
error = ip6_output(m, optp, &in6p->inp_route6,
flags, in6p->inp_moptions6, in6p);
+ if (error == EACCES) /* translate pf(4) error for userland */
+ error = EHOSTUNREACH;
goto releaseopt;
release:
Index: /usr/src/lib/libc/sys/send.2
===================================================================
RCS file: /cvs/src/lib/libc/sys/send.2,v
retrieving revision 1.32
diff -u -p -r1.32 send.2
--- /usr/src/lib/libc/sys/send.2 5 Oct 2017 12:30:16 -0000 1.32
+++ /usr/src/lib/libc/sys/send.2 29 Oct 2018 22:48:24 -0000
@@ -161,13 +161,13 @@ The operation may succeed when buffers b
The output queue for a network interface was full.
This generally indicates that the interface has stopped sending,
but may be caused by transient congestion.
-.It Bq Er EACCES
-The
-.Dv SO_BROADCAST
-option is not set on the socket, and a broadcast address
-was given as the destination.
.It Bq Er EHOSTUNREACH
-The destination address specified an unreachable host.
+The destination address specified a host that is unreachable,
+blocked by
+.Xr pf 4
+or is broadcast communication which was not enabled
+via the socket option
+.Dv SO_BROADCAST .
.It Bq Er EINVAL
The
.Fa flags
