* [PATCH] inet_ntop() and ipv4 address
@ 2013-07-25 4:21 orc
2013-07-25 4:36 ` orc
` (2 more replies)
0 siblings, 3 replies; 7+ messages in thread
From: orc @ 2013-07-25 4:21 UTC (permalink / raw)
To: musl list
[-- Attachment #1: Type: text/plain, Size: 277 bytes --]
inet_ntop() does not embed plain ipv4 address at end (like
"::ffff:10.0.0.1"). This patch fixes it, but it is a bit ugly. Without
it is a bit harder to read logs of some daemons that support only one
address family socket binding and seeing output of 'ss -tn'. Adopt if
needed.
[-- Attachment #2: musl-0.9.10git-inet_ntop-ipv4.patch --]
[-- Type: application/octet-stream, Size: 1079 bytes --]
--- musl.o/src/network/inet_ntop.c
+++ musl/src/network/inet_ntop.c
@@ -18,14 +18,25 @@
return s;
break;
case AF_INET6:
+ memset(buf, 0, sizeof buf);
+ i = (!memcmp(a, buf, 10) &&
+ ((a[10] == 0 && a[11] == 0) || (a[10] == 255 && a[11] == 255))) ? 1 : 0;
memset(buf, 'x', sizeof buf);
buf[sizeof buf-1]=0;
- snprintf(buf, sizeof buf,
- "%x:%x:%x:%x:%x:%x:%x:%x",
- 256*a[0]+a[1],256*a[2]+a[3],
- 256*a[4]+a[5],256*a[6]+a[7],
- 256*a[8]+a[9],256*a[10]+a[11],
- 256*a[12]+a[13],256*a[14]+a[15]);
+ if (i)
+ snprintf(buf, sizeof buf,
+ "%x:%x:%x:%x:%x:%x:%d.%d.%d.%d",
+ 256*a[0]+a[1],256*a[2]+a[3],
+ 256*a[4]+a[5],256*a[6]+a[7],
+ 256*a[8]+a[9],256*a[10]+a[11],
+ a[12],a[13],a[14],a[15]);
+ else
+ snprintf(buf, sizeof buf,
+ "%x:%x:%x:%x:%x:%x:%x:%x",
+ 256*a[0]+a[1],256*a[2]+a[3],
+ 256*a[4]+a[5],256*a[6]+a[7],
+ 256*a[8]+a[9],256*a[10]+a[11],
+ 256*a[12]+a[13],256*a[14]+a[15]);
/* Replace longest /(^0|:)[:0]{2,}/ with "::" */
for (i=best=0, max=2; buf[i]; i++) {
if (i && buf[i] != ':') continue;
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] inet_ntop() and ipv4 address
2013-07-25 4:21 [PATCH] inet_ntop() and ipv4 address orc
@ 2013-07-25 4:36 ` orc
2013-07-25 5:59 ` Rich Felker
2013-07-25 7:42 ` Rich Felker
2 siblings, 0 replies; 7+ messages in thread
From: orc @ 2013-07-25 4:36 UTC (permalink / raw)
To: musl
On Thu, 25 Jul 2013 12:21:27 +0800
orc <orc@sibserver.ru> wrote:
> inet_ntop() does not embed plain ipv4 address at end (like
> "::ffff:10.0.0.1"). This patch fixes it, but it is a bit ugly. Without
> it is a bit harder to read logs of some daemons that support only one
> address family socket binding and seeing output of 'ss -tn'. Adopt if
> needed.
And my mistake: should be
!memcmp(a, buf, 10) && memcmp(a, buf, 14) &&
instead of !memcmp(a, buf, 10)
Sorry.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] inet_ntop() and ipv4 address
2013-07-25 4:21 [PATCH] inet_ntop() and ipv4 address orc
2013-07-25 4:36 ` orc
@ 2013-07-25 5:59 ` Rich Felker
2013-07-25 6:42 ` orc
2013-07-25 7:42 ` Rich Felker
2 siblings, 1 reply; 7+ messages in thread
From: Rich Felker @ 2013-07-25 5:59 UTC (permalink / raw)
To: musl
On Thu, Jul 25, 2013 at 12:21:27PM +0800, orc wrote:
> inet_ntop() does not embed plain ipv4 address at end (like
> "::ffff:10.0.0.1"). This patch fixes it, but it is a bit ugly. Without
> it is a bit harder to read logs of some daemons that support only one
> address family socket binding and seeing output of 'ss -tn'. Adopt if
> needed.
As I understand it, the "IPv4 compatible" addresses (::a.b.c.d) are
deprecated and have never actually been used in deployed IPv6. Only
the v4-mapped form (::ffff:a.b.c.d) is used/usable. For the most part,
supporting the useless form seems harmless, but there is one harmful
case: it looks like your code will wrongly convert :: to ::0.0.0.0
instead of plain ::. Is it worth trying to keep the "v4 compatible"
form supported and just special-casing ::, or should we just drop it?
Rich
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] inet_ntop() and ipv4 address
2013-07-25 5:59 ` Rich Felker
@ 2013-07-25 6:42 ` orc
2013-07-25 6:54 ` Rich Felker
0 siblings, 1 reply; 7+ messages in thread
From: orc @ 2013-07-25 6:42 UTC (permalink / raw)
To: musl
On Thu, 25 Jul 2013 01:59:13 -0400
Rich Felker <dalias@aerifal.cx> wrote:
> On Thu, Jul 25, 2013 at 12:21:27PM +0800, orc wrote:
> > inet_ntop() does not embed plain ipv4 address at end (like
> > "::ffff:10.0.0.1"). This patch fixes it, but it is a bit ugly.
> > Without it is a bit harder to read logs of some daemons that
> > support only one address family socket binding and seeing output of
> > 'ss -tn'. Adopt if needed.
>
> As I understand it, the "IPv4 compatible" addresses (::a.b.c.d) are
> deprecated and have never actually been used in deployed IPv6. Only
> the v4-mapped form (::ffff:a.b.c.d) is used/usable. For the most part,
> supporting the useless form seems harmless, but there is one harmful
> case: it looks like your code will wrongly convert :: to ::0.0.0.0
> instead of plain ::. Is it worth trying to keep the "v4 compatible"
> form supported and just special-casing ::, or should we just drop it?
>
> Rich
I think it's still worth supporting ::ffff:a.b.c.d form, just quote
from my vsftpd logs:
CONNECT: Client "::ffff:a00:203" # (for 10.0.2.3)
Same output of 'ss -tn' when someone connected to IPv6-only listening
socket. IPv4 compatible addresses I taken from glibc.
Wrong convert: see my next message. It was my fault.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] inet_ntop() and ipv4 address
2013-07-25 6:42 ` orc
@ 2013-07-25 6:54 ` Rich Felker
2013-07-25 7:09 ` orc
0 siblings, 1 reply; 7+ messages in thread
From: Rich Felker @ 2013-07-25 6:54 UTC (permalink / raw)
To: musl
On Thu, Jul 25, 2013 at 02:42:12PM +0800, orc wrote:
> On Thu, 25 Jul 2013 01:59:13 -0400
> Rich Felker <dalias@aerifal.cx> wrote:
>
> > On Thu, Jul 25, 2013 at 12:21:27PM +0800, orc wrote:
> > > inet_ntop() does not embed plain ipv4 address at end (like
> > > "::ffff:10.0.0.1"). This patch fixes it, but it is a bit ugly.
> > > Without it is a bit harder to read logs of some daemons that
> > > support only one address family socket binding and seeing output of
> > > 'ss -tn'. Adopt if needed.
> >
> > As I understand it, the "IPv4 compatible" addresses (::a.b.c.d) are
> > deprecated and have never actually been used in deployed IPv6. Only
> > the v4-mapped form (::ffff:a.b.c.d) is used/usable. For the most part,
> > supporting the useless form seems harmless, but there is one harmful
> > case: it looks like your code will wrongly convert :: to ::0.0.0.0
> > instead of plain ::. Is it worth trying to keep the "v4 compatible"
> > form supported and just special-casing ::, or should we just drop it?
>
> I think it's still worth supporting ::ffff:a.b.c.d form, just quote
> from my vsftpd logs:
Oh I agree the ::ffff:a.b.c.d form is worth supporting. I was asking
if there's any need to also support the ::a.b.c.d form, which would
require a special workaround for ::.
Rich
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] inet_ntop() and ipv4 address
2013-07-25 6:54 ` Rich Felker
@ 2013-07-25 7:09 ` orc
0 siblings, 0 replies; 7+ messages in thread
From: orc @ 2013-07-25 7:09 UTC (permalink / raw)
To: musl
On Thu, 25 Jul 2013 02:54:33 -0400
Rich Felker <dalias@aerifal.cx> wrote:
> On Thu, Jul 25, 2013 at 02:42:12PM +0800, orc wrote:
> > On Thu, 25 Jul 2013 01:59:13 -0400
> > Rich Felker <dalias@aerifal.cx> wrote:
> >
> > > On Thu, Jul 25, 2013 at 12:21:27PM +0800, orc wrote:
> > > > inet_ntop() does not embed plain ipv4 address at end (like
> > > > "::ffff:10.0.0.1"). This patch fixes it, but it is a bit ugly.
> > > > Without it is a bit harder to read logs of some daemons that
> > > > support only one address family socket binding and seeing
> > > > output of 'ss -tn'. Adopt if needed.
> > >
> > > As I understand it, the "IPv4 compatible" addresses (::a.b.c.d)
> > > are deprecated and have never actually been used in deployed
> > > IPv6. Only the v4-mapped form (::ffff:a.b.c.d) is used/usable.
> > > For the most part, supporting the useless form seems harmless,
> > > but there is one harmful case: it looks like your code will
> > > wrongly convert :: to ::0.0.0.0 instead of plain ::. Is it worth
> > > trying to keep the "v4 compatible" form supported and just
> > > special-casing ::, or should we just drop it?
> >
> > I think it's still worth supporting ::ffff:a.b.c.d form, just quote
> > from my vsftpd logs:
>
> Oh I agree the ::ffff:a.b.c.d form is worth supporting. I was asking
> if there's any need to also support the ::a.b.c.d form, which would
> require a special workaround for ::.
>
> Rich
If it needs hacks that don't worth implementing, then no. Can't
remember where I seen ::a.b.c.d last time.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] inet_ntop() and ipv4 address
2013-07-25 4:21 [PATCH] inet_ntop() and ipv4 address orc
2013-07-25 4:36 ` orc
2013-07-25 5:59 ` Rich Felker
@ 2013-07-25 7:42 ` Rich Felker
2 siblings, 0 replies; 7+ messages in thread
From: Rich Felker @ 2013-07-25 7:42 UTC (permalink / raw)
To: musl
On Thu, Jul 25, 2013 at 12:21:27PM +0800, orc wrote:
> inet_ntop() does not embed plain ipv4 address at end (like
> "::ffff:10.0.0.1"). This patch fixes it, but it is a bit ugly. Without
> it is a bit harder to read logs of some daemons that support only one
> address family socket binding and seeing output of 'ss -tn'. Adopt if
> needed.
I just committed a simplified version, as well as a bugfix for an
issue I noticed due to looking at this code again. Let me know if you
think anything still needs to be changed.
Rich
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2013-07-25 7:42 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
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2013-07-25 4:21 [PATCH] inet_ntop() and ipv4 address orc
2013-07-25 4:36 ` orc
2013-07-25 5:59 ` Rich Felker
2013-07-25 6:42 ` orc
2013-07-25 6:54 ` Rich Felker
2013-07-25 7:09 ` orc
2013-07-25 7:42 ` Rich Felker
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