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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=4 sw=2 sts=2 et cin: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "GetAddrInfo.h"
#include "mozilla/glean/NetwerkMetrics.h"
#include "mozilla/net/DNSPacket.h"
#include "nsIDNSService.h"
#include "mozilla/StaticPrefs_network.h"
#include <dns_sd.h>
#include <unistd.h>
#include <arpa/inet.h>
namespace mozilla::net {
#define LOG(msg, ...) \
MOZ_LOG(gGetAddrInfoLog, LogLevel::Debug, ("[DNS]: " msg, ##__VA_ARGS__))
struct DNSContext {
nsresult mRv = NS_OK;
TypeRecordResultType* mResult;
nsCString mHost;
uint32_t* mTTL;
};
// Callback for DNSServiceQueryRecord
void QueryCallback(DNSServiceRef aSDRef, DNSServiceFlags aFlags,
uint32_t aInterfaceIndex, DNSServiceErrorType aErrorCode,
const char* aFullname, uint16_t aRRType, uint16_t aRRClass,
uint16_t aRDLen, const void* aRdata, uint32_t aTtl,
void* aContext) {
struct DNSContext* context = (struct DNSContext*)aContext;
LOG("DNS response name: %s type: %u rdlen %u class %u ttl %u", aFullname,
aRRType, aRDLen, aRRClass, aTtl);
if (aErrorCode != kDNSServiceErr_NoError) {
LOG("Error resolving record: %d\n", aErrorCode);
context->mRv = NS_ERROR_UNKNOWN_HOST;
return;
}
if (NS_FAILED(context->mRv)) {
LOG("Parsing already failed for a previous record");
return;
}
// Process the rdata for HTTPS records (type 65)
if (aRRType != TRRTYPE_HTTPSSVC || aRDLen == 0) {
context->mRv = NS_ERROR_UNKNOWN_HOST;
return;
}
nsDependentCString fullname(aFullname);
if (fullname.Length() && fullname.Last() == '.') {
// The fullname argument is always FQDN
fullname.Rebind(aFullname, fullname.Length() - 1);
}
struct SVCB parsed;
nsresult rv = DNSPacket::ParseHTTPS(
aRDLen, parsed, 0, (const unsigned char*)aRdata, aRDLen, fullname);
if (NS_FAILED(rv)) {
LOG("ParseHTTPS failed\n");
context->mRv = rv;
return;
}
if (parsed.mSvcDomainName.IsEmpty() && parsed.mSvcFieldPriority == 0) {
// For AliasMode SVCB RRs, a TargetName of "." indicates that the
// service is not available or does not exist.
return;
}
if (parsed.mSvcFieldPriority == 0) {
// Alias form SvcDomainName must not have the "." value (empty)
if (parsed.mSvcDomainName.IsEmpty()) {
context->mRv = NS_ERROR_UNEXPECTED;
return;
}
LOG("alias mode %s -> %s", context->mHost.get(),
parsed.mSvcDomainName.get());
context->mHost = parsed.mSvcDomainName;
ToLowerCase(context->mHost);
return;
}
if (!context->mResult->is<TypeRecordHTTPSSVC>()) {
*context->mResult = mozilla::AsVariant(CopyableTArray<SVCB>());
}
auto& results = context->mResult->as<TypeRecordHTTPSSVC>();
results.AppendElement(parsed);
*context->mTTL = std::min<uint32_t>(*context->mTTL, aTtl);
}
nsresult ResolveHTTPSRecordImpl(const nsACString& aHost,
nsIDNSService::DNSFlags aFlags,
TypeRecordResultType& aResult, uint32_t& aTTL) {
nsAutoCString host(aHost);
nsAutoCString cname;
if (xpc::IsInAutomation() &&
!StaticPrefs::network_dns_native_https_query_in_automation()) {
return NS_ERROR_UNKNOWN_HOST;
}
LOG("resolving %s\n", host.get());
TimeStamp startTime = TimeStamp::Now();
struct DNSContext context{
.mResult = &aResult,
.mHost = host,
.mTTL = &aTTL,
};
DNSServiceRef sdRef;
DNSServiceErrorType err;
err = DNSServiceQueryRecord(&sdRef,
0, // No flags
0, // All interfaces
host.get(), TRRTYPE_HTTPSSVC, kDNSServiceClass_IN,
QueryCallback, &context);
if (err != kDNSServiceErr_NoError) {
LOG("DNSServiceQueryRecord failed: %d\n", err);
return NS_ERROR_UNKNOWN_HOST;
}
int fd = DNSServiceRefSockFD(sdRef);
fd_set readfds;
FD_ZERO(&readfds);
FD_SET(fd, &readfds);
// If the domain queried results in NXDOMAIN, then QueryCallback will
// never get called, and select will hang forever. We need to use a
// timeout so that select() eventually returns.
struct timeval timeout;
timeout.tv_sec =
StaticPrefs::network_dns_native_https_timeout_mac_msec() / 1000;
timeout.tv_usec =
(StaticPrefs::network_dns_native_https_timeout_mac_msec() % 1000) * 1000;
int result = select(fd + 1, &readfds, NULL, NULL, &timeout);
if (result > 0 && FD_ISSET(fd, &readfds)) {
// Process the result
DNSServiceProcessResult(sdRef);
} else if (result < 0) {
LOG("select() failed");
} else if (result == 0) {
LOG("select timed out");
}
// Cleanup
DNSServiceRefDeallocate(sdRef);
mozilla::glean::networking::dns_native_https_call_time.AccumulateRawDuration(
TimeStamp::Now() - startTime);
LOG("resolving %s done %x ttl=%u", host.get(), context.mRv, aTTL);
if (NS_FAILED(context.mRv)) {
return context.mRv;
}
if (aResult.is<Nothing>()) {
// The call succeeded, but no HTTPS records were found.
return NS_ERROR_UNKNOWN_HOST;
}
if (aTTL == UINT32_MAX) {
aTTL = 60; // Defaults to 60 seconds
}
return NS_OK;
}
void DNSThreadShutdown() {}
} // namespace mozilla::net
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