MySQL Bugs: #52381: Cannot connect to server with IPv6 using hostname or IPv4 address

Bug #52381	Cannot connect to server with IPv6 using hostname or IPv4 address
Submitted:	26 Mar 2010 0:10	Modified:	4 Aug 2010 22:35
Reporter:	Elena Stepanova	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server	Severity:	S2 (Serious)
Version:	5.5.3-m3	OS:	Windows (Server 2008)
Assigned to:	Vladislav Vaintroub	CPU Architecture:	Any

Description:
I cannot connect to local MySQL server on Windows Server 2008 box using TCP protocol if host is explicitly set to:
- 127.0.0.1;
- IPv4 address;
- full host name

I also cannot connect to the same server remotely, using TCP protocol with host set to:
- IPv4 address;
- full host name;
- short host name

Each of the above causes error 2003 (Can't connect to MySQL server) on 5.5.3-m3, while works OK on 5.5.2.

Also, if I try to connect (locally) to the server using short host name, it requires a user to be configured with server's IPv6 address, while on 5.5.2-m2 it would recognize the host name. 

My guess is it might have something to do with the bugfix for bug#43006.

I could reproduce the problem on two Server 2008 machines where IPv6 is enabled, but could not repeat it on an XP machine and it does not show up in our regular tests on Server 2003 boxes (all without IPv6); I don't have any other configurations to experiment.

How to repeat:
Try to connect to a local server using the following command line templates:

mysql -uroot --protocol=tcp --port=3306 --host=127.0.0.1
ERROR 2003 (HY000): Can't connect to MySQL server on '127.0.0.1' (10061)

mysql -uroot --protocol=tcp --port=3306 --host=<full host name>
ERROR 2003 (HY000): Can't connect to MySQL server on '<full host name>' (10061)

mysql -uroot --protocol=tcp --port=3306 --host=<IPv4 address>
ERROR 2003 (HY000): Can't connect to MySQL server on '<IPv4 address>' (10061)

mysql -uroot --protocol=tcp --port=3306 --host=<short host name>
ERROR 1130 (HY000): Host '<IPv6 address>' is not allowed to connect to this MySQL server

Or, try to connect to a remote server using the following command line templates:

mysql -uroot --protocol=tcp --port=3306 --host=<full host name>
ERROR 2003 (HY000): Can't connect to MySQL server on '<full host name>' (10061)

mysql -uroot --protocol=tcp --port=3306 --host=<IPv4 address>
ERROR 2003 (HY000): Can't connect to MySQL server on '<IPv4 address>' (10061)

mysql -uroot --protocol=tcp --port=3306 --host=<short host name>
ERROR 2003 (HY000): Can't connect to MySQL server on '<short host name>' (10061)

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/104487

3144 Vladislav Vaintroub	2010-03-26
      Bug #52381 Cannot connect to server with IPv6 using hostname or IPv4
      address
      
      The bug occurs on Visual Studio 2005. IPV6_V6ONLY TCP flag is not
      defined in the VS2005 SDK (it is an older pre-Vista one).
      The code in mysqld.cc responsible for creating dual-mode socket is
      enclosed into #ifdef IPV6_V6ONLY. When compiled with VS2005,
      v6only socket option is not cleared which results into server listening
      only on IPV6 address.
      
      There used to be a workaround for this problem, defining IPV6_V6ONLY expli
      citly when it is not defined in system headers. The  system checks  for it 
      are already in place in CMake, but the results were precached 
      (i.e check was effectively deactivated). The patch reactivates checks for 
      IPV6_V6ONLY on pre-VS2008 Visual Studio. If these constants are  not found, 
      my_config.h will contain
      #define IPV6_V6ONLY 27
      and this will make mysqld.cc compile with socket dual-mode  again.

Hello,

there are two issues here:

1. mysql -uroot --protocol=tcp --port=3306 --host=127.0.0.1
ERROR 2003 (HY000): Can't connect to MySQL server on '127.0.0.1' (10061)

This is a build problem -- old compiler was used to build binaries.
Wlad addressed this.

2. mysql -uroot --protocol=tcp --port=3306 --host=loki14
ERROR 1130 (HY000): Host 'fe80::358d:f4cd:8288:644e%10' is not allowed to
connect to this MySQL server

What happens here is the following:

  - client resolves 'loki14' to IPv6-address 'fe80::358d:f4cd:8288:644e%10'
    (5.5.2 resolved it to IPv4-address);

  - server resolves the IPv6-address to 'loki14.norway.sun.com' (FQDN, not
    hostname only);

  - server uses FCrDNS technique:
    - on the previous step IPv6-address resolved to hostname.domainname;
    - now the server tries to get IPv6-address back from
      hostname.domainname.
  
    So, server tries to verify that 'loki14.norway.sun.com' has
    that IPv6-address, but fails!

    getaddrinfo('loki14.norway.sun.com') returns IPv4-address only;
    getaddrinfo('loki14') returns both IPv4-address and IPv6-address.

    So, FCrDNS check fails, thus the server does not trust hostname
    resolved from the IPv6-address and does not use it for further
    authentication.

The FCrDNS check fails because the host is misconfigured: its FQDN is just
'loki14' (set in My Computer properties), while it should be
'loki14.norway.sun.com'.

This issue was reproduced locally on Windows 7. After setting "full
computer name" in My Computer properties, everything works as expected.

The error message displayed on the client is a bit misleading and
probably should be corrected. However that requires additional efforts
and it's not clear if the efforts worth it.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/105879

3161 Vladislav Vaintroub	2010-04-16
      Bug #52381 Cannot connect to server with IPv6 using hostname or IPv4
      address
            
      The bug occurs on Visual Studio 2005. IPV6_V6ONLY TCP flag is not
      defined in the VS2005 SDK (it is an older pre-Vista one).
      The code in mysqld.cc responsible for creating dual-mode socket is
      enclosed into #ifdef IPV6_V6ONLY. When compiled with VS2005,
      v6only socket option is not cleared which results into server listening
      only on IPV6 address.
            
      There used to be a workaround for this problem, defining IPV6_V6ONLY expli
      citly when it is not defined in system headers. The  system checks  for it 
      are already in place in CMake, but the results were precached 
      (i.e check was effectively deactivated). The patch reactivates checks for 
      IPV6_V6ONLY on pre-VS2008 Visual Studio. If these constants are  not found, 
      my_config.h will contain
      #define IPV6_V6ONLY 27
      and this will make mysqld.cc compile with socket dual-mode  again.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/105882

3161 Vladislav Vaintroub	2010-04-16
      Bug #52381 Cannot connect to server with IPv6 using hostname or IPv4
      address
            
      The bug occurs on Visual Studio 2005. IPV6_V6ONLY TCP flag is not
      defined in the VS2005 SDK (it is an older pre-Vista one).
      The code in mysqld.cc responsible for creating dual-mode socket is
      enclosed into #ifdef IPV6_V6ONLY. When compiled with VS2005,
      v6only socket option is not cleared which results into server listening
      only on IPV6 address.
            
      There used to be a workaround for this problem, defining IPV6_V6ONLY expli
      citly when it is not defined in system headers. The  system checks  for it 
      are already in place in CMake, but the results were precached 
      (i.e check was effectively deactivated). The patch reactivates checks for 
      IPV6_V6ONLY on pre-VS2008 Visual Studio. If these constants are  not found, 
      my_config.h will contain
      #define IPV6_V6ONLY 27
      and this will make mysqld.cc compile with socket dual-mode  again.

pushed to next-mr-bugfixing,  6.0-codebase-bugfixing

Bug#52411 has been closed as a duplicate of this bug.

Pushed into 6.0.14-alpha (revid:alik@sun.com-20100427094135-5s49ecp3ckson6e2) (version source revid:alik@sun.com-20100427093843-uekr85qkd7orx12t) (merge vers: 6.0.14-alpha) (pib:16)

Pushed into mysql-next-mr (revid:alik@sun.com-20100427094036-38frbg3famdlvjup) (version source revid:alik@sun.com-20100427093825-92wc8b22d4yg34ju) (pib:16)

Noted in 6.0.14 changelog.

On Windows, an IPv6 connection to the server could not be made using
an IPv4 address or host name.

Pushed into mysql-trunk 5.6.1-m4 (revid:alik@ibmvm-20100804080001-bny5271e65xo34ig) (version source revid:alik@sun.com-20100427095914-pzlxbqjjtnngxmf0) (merge vers: 5.6.99-m4) (pib:18)

Pushed into mysql-trunk 5.6.1-m4 (revid:alik@ibmvm-20100804081533-c1d3rbipo9e8rt1s) (version source revid:alik@sun.com-20100427095914-pzlxbqjjtnngxmf0) (merge vers: 5.6.99-m4) (pib:18)

Noted in 5.6.0 changelog.