Skip to content

patch to support mDNS and multicast to servers #148

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
ka2ddo wants to merge 11 commits into
base: master
Choose a base branch
from
+235 −92
Open

patch to support mDNS and multicast to servers #148

Changes from 1 commit
Commits
Show all changes
11 commits
Select commit Hold shift + click to select a range
504fe0d
Update SimpleResolver.java
ka2ddo Jan 6, 2021
fce0cf8
Update NioUdpClient.java
ka2ddo Jan 6, 2021
544182b
Update SimpleResolver.java
ka2ddo Jan 6, 2021
855b7be
reduce duplicate code in mDNS support changes
ka2ddo Jan 7, 2021
1cf8fb8
reduce duplicated code in mDNS changes
ka2ddo Jan 7, 2021
cc916e5
resolve format complaints in mDNS-modified code
ka2ddo Jan 7, 2021
e838df6
resolve format complaints in mDNS changes
ka2ddo Jan 7, 2021
92d98d5
resolve issues reported by dnsjava over regarding consistent behavior
ka2ddo Mar 13, 2021
80aa3cd
a few more bugfixes to the mDNS changes per dnsjava author's request.
ka2ddo Mar 13, 2021
31f2621
make the format checker happy (again!).
ka2ddo Mar 13, 2021
c1ce27b
more formatting issues that the online checker didn't report on the
ka2ddo Mar 13, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
Prev Previous commit
Next Next commit
make the format checker happy (again!).
  • Loading branch information
@ka2ddo
ka2ddo committed Mar 13, 2021
commit 31f26216f5627117cc3b4e398381095dc626be1e
87 changes: 45 additions & 42 deletions src/main/java/org/xbill/DNS/SimpleResolver.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -355,48 +355,48 @@ CompletableFuture<Message> sendAsync(Message query, boolean forceTcp) {
CompletableFuture<Message> f = new CompletableFuture<>();

VerifyOneResponse verifyOneResponse = new VerifyOneResponse(query, qid);
@SuppressWarnings("unchecked")
Message response = null;
Throwable responseFailureException = null;
for (byte[] in : v) {
Message r = verifyOneResponse.parse(in);
if (r == null) {
responseFailureException = verifyOneResponse.getFailureReason();
continue;
}

verifyTSIG(query, r, in, tsig);
if (!tcp && !ignoreTruncation && r.getHeader().getFlag(Flags.TC)) {
log.debug("Got truncated response for id {}, discarding`", qid);
log.trace("Truncated response: {}", r);
continue;
}
@SuppressWarnings("unchecked")
Copy link
Copy Markdown
Member

@ibauersachs ibauersachs Mar 14, 2021

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is no longer necessary

Copy link
Copy Markdown
Author

@ka2ddo ka2ddo Mar 15, 2021

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

OK

Message response = null;
Throwable responseFailureException = null;
for (byte[] in : v) {
Message r = verifyOneResponse.parse(in);
if (r == null) {
responseFailureException = verifyOneResponse.getFailureReason();
continue;
}

if (response == null) {
response = r;
} else {
// not the first answer, append the results to first response
for (Record rec : r.getSection(Section.ANSWER)) {
response.addRecord(rec, Section.ANSWER);
}
for (Record rec : r.getSection(Section.AUTHORITY)) {
response.addRecord(rec, Section.AUTHORITY);
}
for (Record rec : r.getSection(Section.ADDITIONAL)) {
response.addRecord(rec, Section.ADDITIONAL);
}
}
verifyTSIG(query, r, in, tsig);
if (!tcp && !ignoreTruncation && r.getHeader().getFlag(Flags.TC)) {
log.debug("Got truncated response for id {}, discarding`", qid);
Copy link
Copy Markdown
Member

@ibauersachs ibauersachs Mar 14, 2021

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Where is the fallback to TCP in normal DNS lookups?

log.trace("Truncated response: {}", r);
continue;
}

if (response != null) {
response.setResolver(this);
f.complete(response);
if (response == null) {
response = r;
} else {
if (responseFailureException == null) {
responseFailureException = new SocketTimeoutException("Query timed out");
// not the first answer, append the results to first response
for (Record rec : r.getSection(Section.ANSWER)) {
response.addRecord(rec, Section.ANSWER);
}
for (Record rec : r.getSection(Section.AUTHORITY)) {
response.addRecord(rec, Section.AUTHORITY);
}
for (Record rec : r.getSection(Section.ADDITIONAL)) {
response.addRecord(rec, Section.ADDITIONAL);
}
f.completeExceptionally(responseFailureException);
}
}

if (response != null) {
response.setResolver(this);
f.complete(response);
} else {
if (responseFailureException == null) {
responseFailureException = new SocketTimeoutException("Query timed out");
}
f.completeExceptionally(responseFailureException);
}
return f;
});
}
Expand Down Expand Up @@ -438,10 +438,11 @@ public VerifyOneResponse(Message query, int qid) {
}

/**
* Keep the exception that caused this to fail. We don't throw the exception
* immediately because, when using mDNS, we might get both failing and successful
* answers, in which case we just want to discard the bad answers and keep the
* good ones; the exception only gets thrown if only bad answers are received.
* Keep the exception that caused this to fail. We don't throw the exception immediately
* because, when using mDNS, we might get both failing and successful answers, in which case we
* just want to discard the bad answers and keep the good ones; the exception only gets thrown
* if only bad answers are received.
*
* @return the Throwable reporting why this parse failed.
*/
public Throwable getFailureReason() {
Expand All @@ -463,7 +464,8 @@ public Message parse(byte[] in) {
// doesn't confuse us.
int id = ((in[0] & 0xFF) << 8) + (in[1] & 0xFF);
if (id != qid) {
failureReasonException = new WireParseException("invalid message id: expected " + qid + "; got id " + id);
failureReasonException =
new WireParseException("invalid message id: expected " + qid + "; got id " + id);
return null;
}

Expand All @@ -486,7 +488,8 @@ public Message parse(byte[] in) {
return null;
}

if ((query.getQuestion().getDClass() & ~DClass.UNICAST_RESPONSE) != (r.getQuestion().getDClass() & ~DClass.UNICAST_RESPONSE)) {
if ((query.getQuestion().getDClass() & ~DClass.UNICAST_RESPONSE)
Copy link
Copy Markdown
Member

@ibauersachs ibauersachs Mar 14, 2021

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

  • This masking must only be applied for mDNS, not regular DNS
  • In the mDNS case, the mask should be 0x7FFF so that 32768 to 65535 is ignored (see the note at IANA or in the RFC)

!= (r.getQuestion().getDClass() & ~DClass.UNICAST_RESPONSE)) {
failureReasonException =
new WireParseException(
"invalid class in message: expected "
Expand Down