DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 94915386D61E
To: "jhg AT acm DOT org" <jhg AT acm DOT org>, "cygwin AT cygwin DOT com" <cygwin AT cygwin DOT com>
CC: Jim Garrison <jhg AT jhmg DOT net>
Subject: RE: [EXTERNAL] Re: Win 11 Cygwin dns-utils "dig" and "host": Option
 -6 causes command to timeout
Thread-Topic: [EXTERNAL] Re: Win 11 Cygwin dns-utils "dig" and "host": Option
 -6 causes command to timeout
Thread-Index: AQHaX6uQPWElfnvch0SejVQdiqeSM7ELsUyAgAAaISCAAAT+kA==
Date: Thu, 15 Feb 2024 20:00:07 +0000
Deferred-Delivery: Thu, 15 Feb 2024 19:59:56 +0000
Message-ID: <DM8PR09MB7095DA8C5570DDB5C4380B69A54D2@DM8PR09MB7095.namprd09.prod.outlook.com>
References: <00209ed4-b4a3-4125-9a8a-32ea0fcefc7d AT jhmg DOT net>
 <c874178f-dc16-4725-94e5-5a92f98e424e AT SystematicSW DOT ab DOT ca>
 <02234806-fd8b-4a4f-885f-c6d294603c83 AT jhmg DOT net>
 <DM8PR09MB7095DB43FE40F81A176B8F3EA54D2 AT DM8PR09MB7095 DOT namprd09 DOT prod DOT outlook DOT com>
In-Reply-To: <DM8PR09MB7095DB43FE40F81A176B8F3EA54D2@DM8PR09MB7095.namprd09.prod.outlook.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?LquJqGTJje24rvauFEC+mkiwHsQGn7WeMyQS56avogt1OuDYEKQUTKJVoQ/y?=
 =?us-ascii?Q?0zqNZqcFDyDv/rpBlBFNNTpSvMJ6xbp4brdZ8EA4Bn+Eq1FeYycGqb1o22m1?=
 =?us-ascii?Q?rudAydTRQllexCFcfglJq+n+b72vHq+RzB1GQ4SwEXyZzUbpZetPPpvGVF4M?=
 =?us-ascii?Q?JTOplo4RaOL2WC+ohmNd7mFJ3D+DOjoDoY911PrtPn581lIBBk0wbEJ/KIYi?=
 =?us-ascii?Q?FuZMf4HEIE31oWBDMEfd2vV6Ws3DnFmAlOm+MiQMtYAttNdVr5NPGz2tN1yb?=
 =?us-ascii?Q?6xcjQffP0dGwAyE4pE1H0H9+vXUMbbH9OfVfB8pEeE6/kH4YSjD0PhevnkjZ?=
 =?us-ascii?Q?D4HDI8BytGo6hqm4I5wF82L2VevfnqmJr8ZbYhwpp0u3gW4+G5ZwUHx+q+tx?=
 =?us-ascii?Q?xIgkTHolerSbcIv9W4TCkhCmZr6lYiN7GbAzGQt4VfGwTlcxEwA7SrHfRrTi?=
 =?us-ascii?Q?kjnq3yQbnleKtbxkFsKFsVUyqRrctD7zXzrDtpeHtuxW6rH2xorbEz/YdxNy?=
 =?us-ascii?Q?c7egLeQvbTj7jkGXYI46SpjmQ7Uk/u07Iukqsl2frnl2+Bjcj4awl/1TGXtj?=
 =?us-ascii?Q?UaVXzGdhSNnF+l0NKo9V2eiUBqVHkKvNFLT3mxOBXgilp/QBo7uZs2r9ciIU?=
 =?us-ascii?Q?qvPPn4b2REu41kUCq6AHr0db1oOZHAmwfsJ5TvPcoda8orQH2rQdgHpsF3kz?=
 =?us-ascii?Q?5LSh39r8y14nQrZ0J6sxYTmzZ9ymwb+T+lql3WG0ITrH9500mjBRXddNHCER?=
 =?us-ascii?Q?scNiTc5JMngmA9ACElfz7BtsvAseLGdXTYUvWKOe6+MPsBb9gqiJBFI92GGD?=
 =?us-ascii?Q?LncJqsfEVvnEQtr/qeiYJlNyEdFP6IutXp9Cg167F/ykJ9ATpz6G88koUy6P?=
 =?us-ascii?Q?NCa8aSgDCxPy2DWLORzENhmDBFrnr/dtCffvaGp5P1ByCc0E3MbGCIl8eXds?=
 =?us-ascii?Q?BO+jUvqbE4Riz2pu3VkagmMOW+Pzp1ApZdc6oNGCOL09ErgUSMHLFPXR0q8I?=
 =?us-ascii?Q?SoKbKrTT/XaBo+86liSx8WoumEB59cC1Rby7OLktnNJAil6zZ/b6G2QqrPtr?=
 =?us-ascii?Q?eK6SKh2BeIdU47qsugM8v0v3eE0NpVZIDu80T+ihjQiXcU3h0FSglbI95GEg?=
 =?us-ascii?Q?qbKoIgylXi01FOEi3p2nO1Yeji3GOrfZCFtsqBAt4bzrJp3ECjr8fGGyy6NR?=
 =?us-ascii?Q?TBoWE0Kanpi5YLcQRlwNgwWT1262jp8l/OYQ+9zEmXGMQPMZ8HQ4piVDZ1fi?=
 =?us-ascii?Q?8aleUiLyZ1aMGknfkokmCT/8MYXrm+mw5jS2WQD2FcdNfdy5U6h9qyKbp5A9?=
 =?us-ascii?Q?Xh3HCYODvXyHrfeA4tOnRILiX3i9nqKsmorw7XGvp2XO2hYhdzHxFuHNbnuS?=
 =?us-ascii?Q?Ebn4r8HC9/4PXK6R3KESMIhGUL0gB9DAEK7dn9v8/865UZIBOY+KO5slsvTs?=
 =?us-ascii?Q?OzsNW2XflOju/NqXj05jsSE0vT25eiR0W0bF/WYMwINOKKEaRjQRlOWGEV6i?=
 =?us-ascii?Q?71CU9Uzf5zxbRN0TmIN9HG4sx88gJMkoGJ80De1t731dEu5MttOdU9jmpefk?=
 =?us-ascii?Q?baffWNstOvRSt+Zh1i8=3D?=
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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
X-OriginatorOrg: ncbi.nlm.nih.gov
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: DM8PR09MB7095.namprd09.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: baa6f2e4-0dcd-4522-591e-08dc2e60bcb8
X-MS-Exchange-CrossTenant-originalarrivaltime: 15 Feb 2024 20:00:19.7236 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 14b77578-9773-42d5-8507-251ca2dc2b06
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR09MB9333
X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00, DKIM_SIGNED,
 DKIM_VALID, DKIM_VALID_EF, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE,
 T_SPF_HELO_PERMERROR autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
 server2.sourceware.org
X-BeenThere: cygwin AT cygwin DOT com
X-Mailman-Version: 2.1.30
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From: "Lavrentiev, Anton \(NIH/NLM/NCBI\) \[C\] via Cygwin" <cygwin AT cygwin DOT com>
Reply-To: "Lavrentiev, Anton \(NIH/NLM/NCBI\) \[C\]" <lavr AT ncbi DOT nlm DOT nih DOT gov>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: "Cygwin" <cygwin-bounces+archive-cygwin=delorie DOT com AT cygwin DOT com>

Correction:

> (That would be "options osquery".)

Sorry, I have forgotten a few pieces since last time I worked with that code.

So in the absence of "/etc/resolv.conf", Cygwin uses OS (Windows DNS Query) API.

If /etc/resolv.conf is present, then "options osquery" tells Cygwin to use
the Windows DNS API (and conversely, if that option is not there, Cygwin
resolver sends and processes DNS queries on its own).

The code can be looked at here:

https://www.cygwin.com/cgit/newlib-cygwin/tree/winsup/cygwin/libc/minires.c

In particular, you can use the following options to debug what Cygwin is doing in the resolver:

options debug          # Cygwin own resolver

or

options debug osquery  # Cygwin piggy-backs on Windows

And that's how it is done:
https://www.cygwin.com/cgit/newlib-cygwin/tree/winsup/cygwin/libc/minires-os-if.c

HTH,

Anton Lavrentiev
Contractor NIH/NLM/NCBI

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple