X-Recipient: archive-cygwin AT delorie DOT com DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A6894386180A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com; s=default; t=1601105418; bh=uylK0MKtnxGq3+wS27l4NiNEjVcvKqJfIxqpSbU3ZCw=; h=Subject:To:References:Date:In-Reply-To:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=YgBt6BDw04idJEYQYoRrVPMemuXIPR6xHgDsBf6A+bieT7fxzA/aVWwpMIpwiOYjO 32GrC43Le+TCJLjS4hucAT2zPOK37qngQ4j7bfQK1k9TQfyX6rxGkhb5VaYQJ0a6/3 DU18c/tP7U2pr+554sRgbSufNMV1QaVmmlvF6hFM= X-Original-To: cygwin AT cygwin DOT com Delivered-To: cygwin AT cygwin DOT com DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 1789A3857C61 Subject: Re: Problems with native Unix domain sockets on Win 10/2019 To: Ken Brown , cygwin AT cygwin DOT com References: <2b0aeab4-983d-e1d7-301f-edfeeb38cc85 AT oracle DOT com>

<97d2b3af-224a-6873-fb4a-55a0ae9cd379 AT cornell DOT edu> <3e3cfe17-7fda-b063-4885-9114db9e748d AT cornell DOT edu> <70b5577f-2cf1-0110-5d3b-cb2bd8ee6df2 AT cornell DOT edu> Message-ID: <69ad720c-8ea6-d3bb-b0a5-5556c4550091@oracle.com> Date: Sat, 26 Sep 2020 08:30:02 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <70b5577f-2cf1-0110-5d3b-cb2bd8ee6df2@cornell.edu> Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9755 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 bulkscore=0 spamscore=0 adultscore=0 mlxscore=0 phishscore=0 suspectscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009260067 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9755 signatures=668680 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxscore=0 phishscore=0 suspectscore=0 mlxlogscore=999 clxscore=1015 priorityscore=1501 impostorscore=0 lowpriorityscore=0 bulkscore=0 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009260068 X-Spam-Status: No, score=-3.1 required=5.0 tests=BAYES_00, BODY_8BITS, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_MSPIKE_H2, SPF_HELO_PASS, SPF_PASS, TXREP, UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: cygwin AT cygwin DOT com X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Michael McMahon via Cygwin Reply-To: Michael McMahon Content-Type: text/plain; charset="windows-1252"; Format="flowed" Errors-To: cygwin-bounces AT cygwin DOT com Sender: "Cygwin" Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by delorie.com id 08Q7Uqtf005717 On 25/09/2020 21:30, Ken Brown wrote: > On 9/25/2020 2:50 PM, Ken Brown via Cygwin wrote: >> On 9/25/2020 10:29 AM, Michael McMahon wrote: >>> >>> >>> On 25/09/2020 14:19, Ken Brown wrote: >>>> On 9/24/2020 8:01 AM, Michael McMahon wrote: >>>>> >>>>> >>>>> On 24/09/2020 12:26, Ken Brown wrote: >>>>>> On 9/23/2020 7:25 AM, Michael McMahon via Cygwin wrote: >>>>>>> Hi, >>>>>>> >>>>>>> I searched for related issues but haven't found anything. >>>>>>> >>>>>>> I am having some trouble with Windows native Unix domain sockets >>>>>>> (a recent feature in Windows 10 and 2019 server) and Cygwin. >>>>>>> I think I possibly know the cause since I had to investigate a >>>>>>> similar >>>>>>> looking issue on another platform built on Windows. >>>>>>> >>>>>>> The problem is that cygwin commands don't seem to recognise >>>>>>> native Unix >>>>>>> domain sockets correctly. For example, the socket "foo.sock" should >>>>>>> have the same ownership and similar permissions to other files >>>>>>> in the example below: >>>>>>> >>>>>>> $ ls -lrt >>>>>>> total 2181303 >>>>>>> >>>>>>> -rw-r--r-- 1 mimcmah None 1259 Sep 23 10:22 >>>>>>> test.c >>>>>>> -rwxr-xr-x 1 mimcmah None 3680 Sep 23 10:22 >>>>>>> test.obj >>>>>>> -rwxr-xr-x 1 mimcmah None 121344 Sep 23 10:22 >>>>>>> test.exe >>>>>>> -rw-r----- 1 Unknown+User Unknown+Group 0 Sep 23 10:23 >>>>>>> foo.sock >>>>>>> -rw-r--r-- 1 mimcmah None 144356 Sep 23 10:27 >>>>>>> check.ot >>>>>>> >>>>>>> A bigger problem is that foo.sock can't be deleted with the >>>>>>> cygwin "rm" >>>>>>> command. >>>>>>> >>>>>>> $ rm -f foo.sock >>>>>>> rm: cannot remove 'foo.sock': Permission denied >>>>>>> >>>>>>> $ chmod 777 foo.sock >>>>>>> chmod: changing permissions of 'foo.sock': Permission denied >>>>>>> >>>>>>> $ cmd /c del foo.sock >>>>>>> >>>>>>> But, native Windows commands are okay, as the third example shows. >>>>>>> >>>>>>> I think the problem may relate to the way native Unix domain >>>>>>> sockets are >>>>>>> implemented in Windows and the resulting special handling required. >>>>>>> They are implemented as NTFS reparse points and when opening them >>>>>>> with CreateFile, you need to specify the >>>>>>> FILE_FLAG_OPEN_REPARSE_POINT >>>>>>> flag. Otherwise, you get an ERROR_CANT_ACCESS_FILE. There are other >>>>>>> complications unfortunately, which I'd be happy to discuss further. >>>>>>> >>>>>>> But, to reproduce it, you can compile the attached code snippet >>>>>>> which creates foo.sock in the current directory. Obviously, this >>>>>>> only works on recent versions of Windows 10 and 2019 server. >>>>>> >>>>>> Cygwin doesn't currently support native Windows AF_UNIX sockets, >>>>>> as you've discovered. See >>>>>> >>>>>> https://urldefense.com/v3/__https://cygwin.com/pipermail/cygwin/2020-June/245088.html__;!!GqivPVa7Brio!P7lIFI4rYAtWh8_DtCbRCxT-M_E4vwQ0qwzQ0p656T73BpJ0jbUkLI_bXdA6mmSL9lJcSQ$ >>>>>> >>>>>> for the current state of AF_UNIX sockets on Cygwin, including the >>>>>> possibility of using native Windows AF_UNIX sockets on systems >>>>>> that support them. >>>>>> >>>>>> If all you want is for Cygwin to recognize such sockets and allow >>>>>> you to apply rm, chmod, etc., I don't think it would be hard to >>>>>> add that capability. But I doubt if that's all you want. >>>>>> >>>>>> Further discussion of this will have to wait until Corinna is >>>>>> available. >>>>>> >>>>> >>>>> Thanks for the info. It's mainly about recognition of sockets for >>>>> regular commands. Since these objects can exist on Windows filesystems >>>>> now, potentially created by any kind of Windows application, >>>>> it would be great if Cygwin could handle them, irrespective of whether >>>>> the Cygwin development environment does. Though that sounds like a >>>>> good idea too. >>>> >>>> I think this has a simple fix (attached), but I can't easily test it >>>> because your test program doesn't compile for me. First, I got >>>> >>>> $ gcc -o native_unix_socket native_unix_socket.c >>>> native_unix_socket.c:5:10: fatal error: WS2tcpip.h: No such file or >>>> directory >>>> 5 | #include >>>> | ^~~~~~~~~~~~ >>>> compilation terminated. >>>> >>>> I fixed this by making the include file name lower case. (My system >>>> is case sensitive, so it matters.) >>>> >>>> Next: >>>> >>>> $ gcc -o native_unix_socket native_unix_socket.c >>>> native_unix_socket.c:8:10: fatal error: afunix.h: No such file or >>>> directory >>>> 8 | #include >>>> | ^~~~~~~~~~ >>>> compilation terminated. >>>> >>>> There's no file afunix.h in the Cygwin distribution, but I located >>>> it online and pasted in the contents. The program now compiles but >>>> fails to link: >>>> >>>> $ gcc -o native_unix_socket native_unix_socket.c >>>> /usr/lib/gcc/x86_64-pc-cygwin/10/../../../../x86_64-pc-cygwin/bin/ld: /tmp/cc74urPr.o:native_unix_socket.c:(.text+0x3b): >>>> undefined reference to `__imp_WSAStartup' >>>> /tmp/cc74urPr.o:native_unix_socket.c:(.text+0x3b): relocation >>>> truncated to fit: R_X86_64_PC32 against undefined symbol >>>> `__imp_WSAStartup' >>>> /usr/lib/gcc/x86_64-pc-cygwin/10/../../../../x86_64-pc-cygwin/bin/ld: /tmp/cc74urPr.o:native_unix_socket.c:(.text+0xf2): >>>> undefined reference to `__imp_WSAGetLastError' >>>> /tmp/cc74urPr.o:native_unix_socket.c:(.text+0xf2): relocation >>>> truncated to fit: R_X86_64_PC32 against undefined symbol >>>> `__imp_WSAGetLastError' >>>> /usr/lib/gcc/x86_64-pc-cygwin/10/../../../../x86_64-pc-cygwin/bin/ld: /tmp/cc74urPr.o:native_unix_socket.c:(.text+0x13d): >>>> undefined reference to `__imp_WSAGetLastError' >>>> /tmp/cc74urPr.o:native_unix_socket.c:(.text+0x13d): relocation >>>> truncated to fit: R_X86_64_PC32 against undefined symbol >>>> `__imp_WSAGetLastError' >>>> collect2: error: ld returned 1 exit status >>>> >>>> This is probably easy to fix too, but I don't feel like tracking it >>>> down. Please send compilation instructions (that use Cygwin tools). >>>> >>>> Ken >>> >>> Hi >>> >>> Sorry, I had compiled it in a native Visual C environment. >>> >>> Assuming you have afunix.h in the current directory. >>> >>> gcc -o native_unix_socket -I. native_unix_socket.c -lws2_32 >>> >>> should do it. >> >> Thanks, that works. But now I can't reproduce your problem. Here's >> what I see, using Cygwin 3.1.7 without applying my patch: >> >> $ ./native_unix_socket.exe >> getsockname works >> fam = 1, len = 11 >> offsetof clen = 9 >> strlen = 8 >> name = foo.sock >> >> $ ls -l foo.sock >> -rwxr-xr-x 1 kbrown None 0 2020-09-25 14:39 foo.sock* >> >> $ chmod 644 foo.sock >> >> $ ls -l foo.sock >> -rw-r--r-- 1 kbrown None 0 2020-09-25 14:39 foo.sock >> >> $ rm foo.sock >> >> $ ls -l foo.sock >> ls: cannot access 'foo.sock': No such file or directory >> >> I'm running 64-bit Cygwin on Windows 10 1909. > > I just ran the 'rm' command under gdb to see what's going on, and it > seems that foo.sock is not being recognized as a reparse point. So > maybe your test program, when compiled and run under Cygwin, doesn't > actually produce a native Windows AF_UNIX socket. And when I try to run > it in a Windows Command Prompt, I get > > bind failed 10050 > getsockname failed 10022 > > Can you make your version of the test executable available for me to > try? Or tell me some other way to create a native Windows AF_UNIX socket? > > Ken That is all very strange. I have checked both the gcc compiled and MS compiled executables on my system (2019 server) and they are both definitely producing native AF_UNIX sockets. I can email you the two exe files. They are both quite small. But, first I want to check the patch status of my test system. Thanks, Michael. -- 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