Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: 5aa25a106be747000c280a1e55134b906f9ffc41
https://github.com/WebKit/WebKit/commit/5aa25a106be747000c280a1e55134b906f9ffc41
Author: Alex Christensen <[email protected]>
Date: 2023-05-29 (Mon, 29 May 2023)
Changed paths:
M Source/WebCore/platform/network/DNS.cpp
M Source/WebCore/platform/network/DNS.h
M Source/WebCore/platform/network/cf/DNSResolveQueueCFNet.cpp
Log Message:
-----------
DNS lookup should request then wait for IPv4 and IPv6 addresses
https://bugs.webkit.org/show_bug.cgi?id=257404
rdar://109911384
Reviewed by Youenn Fablet.
As advised by one who knows DNS better than I do, with the code I wrote earlier
today
in https://github.com/WebKit/WebKit/pull/14326 I am missing some of the IP
addresses.
To receive a set of IP addresses equivalent to what CFHost received, I need to
add
the kDNSServiceFlagsReturnIntermediates flag.
Also, there are some times when we receive IPv4 addresses then get a callback
with
kDNSServiceFlagsMoreComing and then sometime later receive IPv6 addresses, or
vice versa.
The addresses from the second set of callbacks were being dropped. To fix this,
I explicitly add the protocols kDNSServiceProtocol_IPv4 |
kDNSServiceProtocol_IPv6
to request callbacks for both protocols. This makes it so that sometimes I get
callbacks with kDNSServiceErr_NoSuchRecord and callbacks with IP addresses that
are all
zeros. We simiply ignore kDNSServiceErr_NoSuchRecord and filter out all the
all-zero
IP addresses. That way the result of DNSResolveQueueCFNet::performDNSLookup
always
contains all the IP addresses.
I manually verified that IP address lists were incomplete sometimes before this
change,
and now they are complete all the time. There are also two unit tests that
exercise
this code path, webrtc/datachannel/mdns-ice-candidates.html and
TestWebKitAPI.WebKit2.RTCDataChannelPostMessage
and I verified that they both pass.
* Source/WebCore/platform/network/DNS.cpp:
(WebCore::IPAddress::isAllZeros const):
* Source/WebCore/platform/network/DNS.h:
* Source/WebCore/platform/network/cf/DNSResolveQueueCFNet.cpp:
(WebCore::DNSResolveQueueCFNet::CompletionHandlerWrapper::complete):
(WebCore::DNSResolveQueueCFNet::CompletionHandlerWrapper::addIPAddress):
(WebCore::DNSResolveQueueCFNet::CompletionHandlerWrapper::shouldWaitForMoreAddresses
const):
(WebCore::DNSResolveQueueCFNet::CompletionHandlerWrapper::filterZeroAddresses):
(WebCore::dnsLookupCallback):
(WebCore::DNSResolveQueueCFNet::performDNSLookup):
Canonical link: https://commits.webkit.org/264655@main
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