[Bug 54819] New: DnsQuery_A() mishandles CNAME DNS records

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54819

Bug ID: 54819
           Summary: DnsQuery_A() mishandles CNAME DNS records
           Product: Wine
           Version: unspecified
          Hardware: x86-64
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: dnsapi
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Specifically this breaks the wpad auto-proxy lookups through this chain:
  InternetQueryOptionW(NULL,...) + INTERNET_PER_CONN_FLAGS (as per
wininet:internet)
  -> calls query_global_option()
  -> calls get_proxy_autoconfig_url()
  -> calls detect_proxy_autoconfig_url_dns()
  -> calls getaddrinfo(AI_DNS_ONLY)
  -> calls DnsQuery_A()

Removing AI_DNS_ONLY bypasses DnsQuery_A() and gets more sensible results...
but see bug 52133.

So anyway, if you have something like this in your DNS configuration:

ns        A    192.168.3.1
wpad        CNAME    ns

You get nonsensical results like:

0024:trace:wininet:detect_proxy_autoconfig_url_dns family=2 addr={ family
AF_INET, address 192.159.62.1, port 0 } canon=(null)
0024:trace:wininet:detect_proxy_autoconfig_url_dns family=2 addr={ family
AF_INET, address 192.168.3.1, port 0 } canon=(null)
0024:trace:wininet:detect_proxy_autoconfig_url_dns family=23 addr={ family
AF_INET6, address 20a0:3e01::7800:7800:7800:7800, flow label 0, port 0, scope 0
} canon=(null)

The 192.168.3.1 is as expected but the 192.159.62.1 result should not be there
and, because it comes first, detect_proxy_autoconfig_url_dns() returns the
wrong URL! Also one gets a different bad IP address for wpad.foo and wpad.bar.

Furthermore this issue can be fixed by changing the DNS confguration to:

ns        A    192.168.3.1
wpad        A    192.168.3.1

So this issue is specific to CNAMEs.

Additional notes:
* I found this issue while debugging bug 54818 but it actually makes no
difference there, it just results in the wrong url getting returned.
* I don't think the IPv6 result makes sense but I'm not sure yet.

[Bug 54819] DnsQuery_A() mishandles CNAME DNS records

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54819

François Gouget  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[e-mail]

[Bug 54819] DnsQuery_A() mishandles CNAME DNS records

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54819

--- Comment #1 from Hans Leidekker  ---
Created attachment 74318
  --> https://bugs.winehq.org/attachment.cgi?id=74318
patch

Does this patch help?

[Bug 54819] DnsQuery_A() mishandles CNAME DNS records

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54819

--- Comment #2 from Dmitry Timoshkov  ---
(In reply to Hans Leidekker from comment #1)
> Created attachment 74318 [details]
> patch
>
> Does this patch help?
> - for (ptr = rec; ptr; ptr = ptr->pNext) { if (rec->wType == DNS_TYPE_A) count++; };
> - for (ptr = rec6; ptr; ptr = ptr->pNext) { if (rec->wType == DNS_TYPE_AAAA) count++; };

ptr->wType?
>  for (ptr = rec6; ptr; ptr = ptr->pNext)
>  {
> -
>    if (rec->wType != DNS_TYPE_AAAA) continue;

Same here.

[Bug 54819] DnsQuery_A() mishandles CNAME DNS records

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54819

--- Comment #3 from Hans Leidekker  ---
Yes, thanks.

[Bug 54819] DnsQuery_A() mishandles CNAME DNS records

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54819

Hans Leidekker  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #74318|0                           |1
        is obsolete|                            |

--- Comment #4 from Hans Leidekker  ---
Created attachment 74319
  --> https://bugs.winehq.org/attachment.cgi?id=74319
patch

[Bug 54819] DnsQuery_A() mishandles CNAME DNS records

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54819

--- Comment #5 from François Gouget  ---
Wow, that was fast!
Thanks, that works.

[Bug 54819] DnsQuery_A() mishandles CNAME DNS records

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54819

Hans Leidekker  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED
      Fixed by SHA1|                            |f512b3c08ccfc9b9c235964002e
                   |                            |644e2cbd657cf
          Component|dnsapi                      |winsock

--- Comment #6 from Hans Leidekker  ---
Fixed with f512b3c08ccfc9b9c235964002e644e2cbd657cf.

[Bug 54819] DnsQuery_A() mishandles CNAME DNS records

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54819

Alexandre Julliard  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |CLOSED

--- Comment #7 from Alexandre Julliard  ---
Closing bugs fixed in 8.6.

[Bug 54819] DnsQuery_A() mishandles CNAME DNS records

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54819

Michael Stefaniuc  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |8.0.x

[Bug 54819] DnsQuery_A() mishandles CNAME DNS records

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=54819

Michael Stefaniuc  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|8.0.x                       |---

--- Comment #8 from Michael Stefaniuc  ---
Removing the 8.0.x milestone from bug fixes included in 8.0.2.