getaddrinfo fails with EAI_NODATA for some valid hosts with A records

getaddrinfo fails with EAI_NODATA for some valid hosts with A records

[Brian Inglis]

getaddrinfo fails with err 7 EAI_NODATA for some valid hosts with A records. 
Err 7 EAI_NODATA is mapped from WSANO_DATA err 11004 in Windows.
Can anyone reproduce failure with problem host name below? 


STC is run on Linux and Cygwin (up to date):

#!/bin/bash
# nslookup, getent hosts, getent ahosts run with good and problem host names
uname -srvmo
nslookup -debug cygwin.org
getent hosts    cygwin.org
getent ahosts   cygwin.org
nslookup -debug leapsecond.utcd.org
getent hosts    leapsecond.utcd.org
getent ahosts   leapsecond.utcd.org
uname -srvmo


# Linux results:
$ uname -srvmo
Linux 4.1.13-v7+ #826 SMP PREEMPT Fri Nov 13 20:19:03 GMT 2015 armv7l GNU/Linux
$ nslookup -debug cygwin.org
Server:         64.59.135.148
Address:        64.59.135.148#53
------------
    QUESTIONS:
        cygwin.org, type = A, class = IN
    ANSWERS:
    ->  cygwin.org
        internet address = 209.132.180.131
        ttl = 300
    AUTHORITY RECORDS:
    ADDITIONAL RECORDS:
------------
Non-authoritative answer:
Name:   cygwin.org
Address: 209.132.180.131
$ getent hosts    cygwin.org
209.132.180.131 cygwin.org
$ getent ahosts   cygwin.org
209.132.180.131 STREAM server1.sourceware.org
209.132.180.131 DGRAM
209.132.180.131 RAW
$ nslookup -debug leapsecond.utcd.org
Server:         64.59.135.148
Address:        64.59.135.148#53
------------
    QUESTIONS:
        leapsecond.utcd.org, type = A, class = IN
    ANSWERS:
    ->  leapsecond.utcd.org
        internet address = 244.34.36.97
        ttl = 600
    AUTHORITY RECORDS:
    ADDITIONAL RECORDS:
------------
Non-authoritative answer:
Name:   leapsecond.utcd.org
Address: 244.34.36.97
$ getent hosts    leapsecond.utcd.org
244.34.36.97    leapsecond.utcd.org
$ getent ahosts   leapsecond.utcd.org
244.34.36.97    STREAM leapsecond.utcd.org
244.34.36.97    DGRAM
244.34.36.97    RAW
$ uname -srvmo
Linux 4.1.13-v7+ #826 SMP PREEMPT Fri Nov 13 20:19:03 GMT 2015 armv7l GNU/Linux


# Cygwin results:
$ uname -srvmo
CYGWIN_NT-6.1 2.3.1(0.291/5/3) 2015-11-14 12:44 x86_64 Cygwin
$ nslookup -debug cygwin.org
Server:         64.59.135.148
Address:        64.59.135.148#53
------------
    QUESTIONS:
        cygwin.org, type = A, class = IN
    ANSWERS:
    ->  cygwin.org
        internet address = 209.132.180.131
        ttl = 199
    AUTHORITY RECORDS:
    ADDITIONAL RECORDS:
------------
Non-authoritative answer:
Name:   cygwin.org
Address: 209.132.180.131
$ getent hosts    cygwin.org
209.132.180.131 cygwin.org
$ getent ahosts   cygwin.org
209.132.180.131 0      cygwin.org
$ nslookup -debug leapsecond.utcd.org
Server:         64.59.135.148
Address:        64.59.135.148#53
------------
    QUESTIONS:
        leapsecond.utcd.org, type = A, class = IN
    ANSWERS:
    ->  leapsecond.utcd.org
        internet address = 244.34.36.97
        ttl = 501
    AUTHORITY RECORDS:
    ADDITIONAL RECORDS:
------------
Non-authoritative answer:
Name:   leapsecond.utcd.org
Address: 244.34.36.97
$ getent hosts    leapsecond.utcd.org
244.34.36.97    leapsecond.utcd.org
$ getent ahosts   leapsecond.utcd.org
$ uname -srvmo
CYGWIN_NT-6.1 2.3.1(0.291/5/3) 2015-11-14 12:44 x86_64 Cygwin



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Re: getaddrinfo fails with EAI_NODATA for some valid hosts with A records

[Corinna Vinschen]

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Hi Brian,

On Jan  7 15:39, Brian Inglis wrote:
> getaddrinfo fails with err 7 EAI_NODATA for some valid hosts with A records. 
> Err 7 EAI_NODATA is mapped from WSANO_DATA err 11004 in Windows.
> Can anyone reproduce failure with problem host name below? 

Yes, I can reproduce it, and it's a total surprise.

In fact, this is *not* a Cygwin problem.  I created an STC, a simple
mingw application, very certainly not using Cygwin at all:

$ cat gai.c
#define _WIN32_WINNT 0x0a00
#include <ws2tcpip.h>
#include <windows.h>
#include <stdio.h>

#ifndef AI_DISABLE_IDN_ENCODING
#define AI_DISABLE_IDN_ENCODING 0x80000
#endif

int
main (int argc, char **argv)
{
  WSADATA wsadata;
  struct addrinfo hint, *res;
  int ret;

  WSAStartup (MAKEWORD(2,2), &wsadata);

  memset (&hint, 0, sizeof hint);
  hint.ai_flags = 0;//AI_V4MAPPED | AI_ADDRCONFIG | AI_CANONNAME | AI_DISABLE_IDN_ENCODING;
  hint.ai_family = 0;//AF_INET;
  ret = getaddrinfo (argv[1], NULL, &hint, &res);
  printf ("ret = %d\n", ret);
}
$ x86_64-w64-mingw32-gcc -g -o gai gai.c -lws2_32
$ ./gai cygwin.org
ret = 0
$ ./gai www.sun.de
ret = 0
$ ./gai leapsecond.utcd.org
ret = 11004

I have no idea why Windows' getaddrinfo chokes on leapsecond.utcd.org
at all.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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Re: getaddrinfo fails with EAI_NODATA for some valid hosts with A records

[cyg Simple]

On 1/8/2016 6:14 AM, Corinna Vinschen wrote:
> $ ./gai leapsecond.utcd.org
> ret = 11004
> 
> I have no idea why Windows' getaddrinfo chokes on leapsecond.utcd.org
> at all.

utcd.org doesn't resolve for me.  So getaddrinfo has no info to get.

-- 
cyg Simple

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Re: getaddrinfo fails with EAI_NODATA for some valid hosts with A records

[Corinna Vinschen]

[-- Attachment #1: Type: text/plain, Size: 502 bytes --]

On Jan  8 13:44, cyg Simple wrote:
> On 1/8/2016 6:14 AM, Corinna Vinschen wrote:
> > $ ./gai leapsecond.utcd.org
> > ret = 11004
> > 
> > I have no idea why Windows' getaddrinfo chokes on leapsecond.utcd.org
> > at all.
> 
> utcd.org doesn't resolve for me.  So getaddrinfo has no info to get.

Why then does it work on Linux?


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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Re: getaddrinfo fails with EAI_NODATA for some valid hosts with A records

[Stephen John Smoogen]

On 8 January 2016 at 11:44, cyg Simple <cygsimple@gmail.com> wrote:
> On 1/8/2016 6:14 AM, Corinna Vinschen wrote:
>> $ ./gai leapsecond.utcd.org
>> ret = 11004
>>
>> I have no idea why Windows' getaddrinfo chokes on leapsecond.utcd.org
>> at all.
>
> utcd.org doesn't resolve for me.  So getaddrinfo has no info to get.
>

utcd.org does not resolve. leapsecond.utcd.org does resolve.

leapsecond.utcd.org has address 244.34.36.97

> --
> cyg Simple
>
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-- 
Stephen J Smoogen.

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RE: getaddrinfo fails with EAI_NODATA for some valid hosts with A records

[Andy Hall]

> 
> On Jan  8 13:44, cyg Simple wrote:
> > On 1/8/2016 6:14 AM, Corinna Vinschen wrote:
> > > $ ./gai leapsecond.utcd.org
> > > ret = 11004
> > >
> > > I have no idea why Windows' getaddrinfo chokes on leapsecond.utcd.org
> > > at all.
> >
> > utcd.org doesn't resolve for me.  So getaddrinfo has no info to get.
> 
> Why then does it work on Linux?
> 

nslookup works for me:

Win7 64-bit

$ nslookup leapsecond.utcd.org
Non-authoritative answer:
Server:  UnKnown
Address:  192.168.1.1

Name:    leapsecond.utcd.org
Address:  244.34.36.97

Win10 64-bit

C:\Users\Andy>nslookup leapsecond.utcd.org
Server:  UnKnown
Address:  192.168.1.1

Non-authoritative answer:
Name:    leapsecond.utcd.org
Address:  244.34.36.97

However,  tracert and ping  yield this on both W7 & W10:

$ tracert leapsecond.utcd.org
Unable to resolve target system name leapsecond.utcd.org.

$ tracert 244.34.36.97

Tracing route to 244.34.36.97 over a maximum of 30 hops

  1  Transmit error: code 1231.

Trace complete.

$ ping 244.34.36.97

Pinging 244.34.36.97 with 32 bytes of data:
PING: transmit failed. General failure.
PING: transmit failed. General failure.
PING: transmit failed. General failure.
PING: transmit failed. General failure.

Ping statistics for 244.34.36.97:
    Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

Weird!





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Re: getaddrinfo fails with EAI_NODATA for some valid hosts with A records

[Brian Inglis]

Andy Hall <fixpertise-consulting <at> comcast.net> writes:
>> On Jan  8 13:44, cyg Simple wrote:
>>> On 1/8/2016 6:14 AM, Corinna Vinschen wrote:
>>>> $ ./gai leapsecond.utcd.org
>>>> ret = 11004
>>>> I have no idea why Windows' getaddrinfo chokes on leapsecond.utcd.org
>>>> at all.
>>> utcd.org doesn't resolve for me.  So getaddrinfo has no info to get.
>> Why then does it work on Linux?
> nslookup works for me:
> Win7 64-bit
> $ nslookup leapsecond.utcd.org
> Non-authoritative answer:
> Server:  UnKnown
> Address:  192.168.1.1
> Name:    leapsecond.utcd.org
> Address:  244.34.36.97
> Win10 64-bit
> C:\Users\Andy>nslookup leapsecond.utcd.org
> Server:  UnKnown
> Address:  192.168.1.1
> Non-authoritative answer:
> Name:    leapsecond.utcd.org
> Address:  244.34.36.97
> However,  tracert and ping  yield this on both W7 & W10:
> $ tracert leapsecond.utcd.org
> Unable to resolve target system name leapsecond.utcd.org.
> $ tracert 244.34.36.97
> Tracing route to 244.34.36.97 over a maximum of 30 hops
>   1  Transmit error: code 1231.
> Trace complete.
> $ ping 244.34.36.97
> Pinging 244.34.36.97 with 32 bytes of data:
> PING: transmit failed. General failure.
> PING: transmit failed. General failure.
> PING: transmit failed. General failure.
> PING: transmit failed. General failure.
> Ping statistics for 244.34.36.97:
>     Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
> Weird!

Everything works in my STC except Cygwin x86/x64 
"getent ahosts leapsecond.utcd.org" 
on Windows 7 x64 which uses Cygwin getaddrinfo. 
Windows getaddrinfo (ASCII names) in Corinna's STC; Cygwin getaddrinfo, and
Windows GetAddrInfoW (UCS2-LE names) used in the Cygwin implementations,
fail in my code. 
Identical code works from Linux via the same router, and Corinna's MinGW STC
indicates the problem is Windows code, not a BLODA, unless we define Windows
as a likely BLODA. ;^> 

Worked around the problem by falling back to trying gethostbyname when gai
returns 7 EAI_NODATA because GAIW returns 11004 WSANO_DATA. That error is
normally reported when there are no A (and/or AAAA, depending on family and
flags in the call) records for a domain name (most commonly only MX for mail
server, possibly CNAME misspelled or with missing associated A/AAAA, or
other DNS mis-configuration). 

Running whois utcd.org replies normally; whois, traceroute/tracert, and ping
all fail on the name and address as there is host at that address. 
The domain, name, address, SOA, NS, A, and PTR records were set up by P-HK
(phk.freebsd.dk) to provide leapsecond info from IERS Bulletin C encoded in
an address in the IP V4 global class E experimental 240/8 space, see code at
http://phk.freebsd.dk/time/20151122.html. 
An update is due next week for the end of June, when no change is expected,
except the date updated to be valid until after then. 



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Re: getaddrinfo fails with EAI_NODATA for some valid hosts with A records

[Brian Inglis]

Brian Inglis <Brian.Inglis <at> SystematicSw.ab.ca> writes:
> Running whois utcd.org replies normally; whois, traceroute/tracert, and ping
> all fail on the name and address as there is host at that address. 

Running whois utcd.org replies normally; whois, traceroute/tracert, and ping
all fail on the name and address as there is *NO* host at that address.


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Re: getaddrinfo fails with EAI_NODATA for some valid hosts with A records

[Brian Inglis]

Corinna Vinschen <corinna-cygwin <at> cygwin.com> writes:
> On Jan  7 15:39, Brian Inglis wrote:
>> getaddrinfo fails with err 7 EAI_NODATA for some valid hosts with A records. 
>> Err 7 EAI_NODATA is mapped from WSANO_DATA err 11004 in Windows.
>> Can anyone reproduce failure with problem host name below? 
> 
> Yes, I can reproduce it, and it's a total surprise.

> I have no idea why Windows' getaddrinfo chokes on leapsecond.utcd.org
> at all.

Especially when after just one getaddrinfo call, the DNS cache is populated
with:
    leapsecond.utcd.org
    ----------------------------------------
    Record Name . . . . . : leapsecond.utcd.org
    Record Type . . . . . : 1
    Time To Live  . . . . : 600
    Data Length . . . . . : 4
    Section . . . . . . . : Answer
    A (Host) Record . . . : 244.34.36.97

so the DNS server is being contacted and responding normally, but it would
appear Windows GAI is failing to use that info. 
Has this been reproduced on W10 so we can report this upstream? 
Is there any support without an account for upstream W7 reports? 


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Re: getaddrinfo fails with EAI_NODATA for some valid hosts with A records

[Corinna Vinschen]

[-- Attachment #1: Type: text/plain, Size: 1323 bytes --]

On Jan 13 08:14, Brian Inglis wrote:
> Corinna Vinschen <corinna-cygwin <at> cygwin.com> writes:
> > On Jan  7 15:39, Brian Inglis wrote:
> >> getaddrinfo fails with err 7 EAI_NODATA for some valid hosts with A records. 
> >> Err 7 EAI_NODATA is mapped from WSANO_DATA err 11004 in Windows.
> >> Can anyone reproduce failure with problem host name below? 
> > 
> > Yes, I can reproduce it, and it's a total surprise.
> 
> > I have no idea why Windows' getaddrinfo chokes on leapsecond.utcd.org
> > at all.
> 
> Especially when after just one getaddrinfo call, the DNS cache is populated
> with:
>     leapsecond.utcd.org
>     ----------------------------------------
>     Record Name . . . . . : leapsecond.utcd.org
>     Record Type . . . . . : 1
>     Time To Live  . . . . : 600
>     Data Length . . . . . : 4
>     Section . . . . . . . : Answer
>     A (Host) Record . . . : 244.34.36.97
> 
> so the DNS server is being contacted and responding normally, but it would
> appear Windows GAI is failing to use that info. 
> Has this been reproduced on W10 so we can report this upstream? 

I can reproduce this on W10 as well.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
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Red Hat

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RE: getaddrinfo fails with EAI_NODATA for some valid hosts with A records

[Andy Hall]

> -----Original Message-----
> From: cygwin-owner@cygwin.com [mailto:cygwin-owner@cygwin.com] On Behalf Of Brian Inglis
> Sent: Wednesday, January 13, 2016 12:14 AM
> To: cygwin@cygwin.com
> Subject: Re: getaddrinfo fails with EAI_NODATA for some valid hosts with A records
> 
> Corinna Vinschen <corinna-cygwin <at> cygwin.com> writes:
> > On Jan  7 15:39, Brian Inglis wrote:
> >> getaddrinfo fails with err 7 EAI_NODATA for some valid hosts with A records.
> >> Err 7 EAI_NODATA is mapped from WSANO_DATA err 11004 in Windows.
> >> Can anyone reproduce failure with problem host name below?
> >
> > Yes, I can reproduce it, and it's a total surprise.
> 
> > I have no idea why Windows' getaddrinfo chokes on leapsecond.utcd.org
> > at all.
> 
> Especially when after just one getaddrinfo call, the DNS cache is populated
> with:
>     leapsecond.utcd.org
>     ----------------------------------------
>     Record Name . . . . . : leapsecond.utcd.org
>     Record Type . . . . . : 1
>     Time To Live  . . . . : 600
>     Data Length . . . . . : 4
>     Section . . . . . . . : Answer
>     A (Host) Record . . . : 244.34.36.97
> 
> so the DNS server is being contacted and responding normally, but it would
> appear Windows GAI is failing to use that info.
> Has this been reproduced on W10 so we can report this upstream?
> Is there any support without an account for upstream W7 reports?
> 
> 
DNS just translates URLs to IP addresses.  It is no surprise that works.   However, addresses in the range 240.0.0.0 -
255.255.255.255 are reserved.   Windows is probably blocking that as a "favor".

Net Range	240.0.0.0 - 255.255.255.255
CIDR	240.0.0.0/4
Name	SPECIAL-IPV4-FUTURE-USE-IANA-RESERVED
Handle	NET-240-0-0-0-0
Parent	
Net Type	IANA Special Use
Origin AS	
Organization	Internet Assigned Numbers Authority (IANA)
Registration Date	
Last Updated	2013-08-30
Comments	Addresses starting with 240 or a higher number have not been allocated and should not be used, apart
from 255.255.255.255, which is used for "limited broadcast" on a local network.

This block was reserved by the IETF, the organization that develops Internet protocols, in the Standard document and in
RFC 1112. The documents can be found at:
http://datatracker.ietf.org/doc/rfc1112
RESTful Link	http://whois.arin.net/rest/net/NET-240-0-0-0-0
See Also	Related organization's POC records.
See Also	Related delegations.


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Re: getaddrinfo fails with EAI_NODATA for some valid hosts with A records

[Brian Inglis]

On 2016-01-13 10:03, Andy Hall wrote:
>> -----Original Message-----
>> From: cygwin
>> On Behalf Of Brian Inglis
>> Corinna Vinschen writes:
>>> On Jan  7 15:39, Brian Inglis wrote:
>>>> getaddrinfo fails with err 7 EAI_NODATA for some valid hosts
>>>> with A records. Err 7 EAI_NODATA is mapped from WSANO_DATA err
>>>> 11004 in Windows. Can anyone reproduce failure with problem
>>>> host name below?

>>> Yes, I can reproduce it, and it's a total surprise.
>>> I have no idea why Windows' getaddrinfo chokes on
>>> leapsecond.utcd.org at all.

>> Especially when after just one getaddrinfo call, the DNS cache is
>> populated with:
>> leapsecond.utcd.org
>> ----------------------------------------
>> Record Name . . . . . : leapsecond.utcd.org
>> Record Type . . . . . : 1
>> Time To Live  . . . . : 600
>> Data Length . . . . . : 4
>> Section . . . . . . . : Answer
>> A (Host) Record . . . : 244.34.36.97
>> so the DNS server is being contacted and responding normally, but
>> it would appear Windows GAI is failing to use that info. Has this
>> been reproduced on W10 so we can report this upstream? Is there any
>> support without an account for upstream W7 reports?

> DNS just translates URLs to IP addresses.  It is no surprise that
> works.   However, addresses in the range 240.0.0.0 - 255.255.255.255
> are reserved.   Windows is probably blocking that as a "favor".
> Net Range	240.0.0.0 - 255.255.255.255 CIDR	240.0.0.0/4 Name
> SPECIAL-IPV4-FUTURE-USE-IANA-RESERVED Handle	NET-240-0-0-0-0 Parent
> Net Type	IANA Special Use Origin AS Organization	Internet Assigned
> Numbers Authority (IANA) Registration Date Last Updated	2013-08-30
> Comments	Addresses starting with 240 or a higher number have not been
> allocated and should not be used, apart from 255.255.255.255, which
> is used for "limited broadcast" on a local network.
> This block was reserved by the IETF, the organization that develops
> Internet protocols, in the Standard document and in RFC 1112. The
> documents can be found at: http://datatracker.ietf.org/doc/rfc1112
> RESTful Link	http://whois.arin.net/rest/net/NET-240-0-0-0-0 See Also
> Related organization's POC records. See Also	Related delegations.

See also IANA services and ports reservations which have been ignored
since Windows devs got a connection to the world outside their PC
(cough Citrix!)

Reserved just means it won't be assigned, but as illustrated by my
OP and Linux tests, it has been usable since CIDR/VLSM came in RFCs
1517-1519 in 1993, and routable since RFC 1812 in 1995 supported
Classless Inter Domain Routing and Variable Length Subnet Masking.

The private reserved address ranges are bogon territory for routers;
the most that can be said about 240/8 is possible bogosity: that
space is available for global internet use without any guarantees
what devices, hosts, protocols, and services will interoperate.

IANA considered releasing the 248M addresses for assignment a few
years ago but decided it was not worth it, as it would only delay
exhaustion of IP V4 space for 18 months, and some crufty old gear
and stacks (cough Windows!) may not support it (as we saw and you
said) for some functions.

Regardless of that, the DNS lookup function should operate normally:
implementing mechanism not policy; if some higher layer wants to
apply a policy on use of those addresses, *THAT*'s what we have
filters for.

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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