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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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
#include "GetAddrInfo.h"
#ifdef DNSQUERY_AVAILABLE
// There is a bug in windns.h where the type of parameter ppQueryResultsSet for
// DnsQuery_A is dependent on UNICODE being set. It should *always* be
// PDNS_RECORDA, but if UNICODE is set it is PDNS_RECORDW. To get around this
// we make sure that UNICODE is unset.
# undef UNICODE
# include <ws2tcpip.h>
# undef GetAddrInfo
# include <windns.h>
#endif // DNSQUERY_AVAILABLE
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/net/DNS.h"
#include "NativeDNSResolverOverrideParent.h"
#include "prnetdb.h"
#include "nsIOService.h"
#include "nsHostResolver.h"
#include "nsError.h"
#include "mozilla/net/DNS.h"
#include <algorithm>
#include "prerror.h"
#include "mozilla/Logging.h"
#include "mozilla/StaticPrefs_network.h"
#include "mozilla/net/DNSPacket.h"
#include "nsIDNSService.h"
namespace mozilla::net {
static StaticRefPtr<NativeDNSResolverOverride> gOverrideService;
LazyLogModule gGetAddrInfoLog("GetAddrInfo");
#define LOG(msg, ...) \
MOZ_LOG(gGetAddrInfoLog, LogLevel::Debug, ("[DNS]: " msg, ##__VA_ARGS__))
#define LOG_WARNING(msg, ...) \
MOZ_LOG(gGetAddrInfoLog, LogLevel::Warning, ("[DNS]: " msg, ##__VA_ARGS__))
#ifdef DNSQUERY_AVAILABLE
# define COMPUTER_NAME_BUFFER_SIZE 100
static char sDNSComputerName[COMPUTER_NAME_BUFFER_SIZE];
static char sNETBIOSComputerName[MAX_COMPUTERNAME_LENGTH + 1];
////////////////////////////
// WINDOWS IMPLEMENTATION //
////////////////////////////
// Ensure consistency of PR_* and AF_* constants to allow for legacy usage of
// PR_* constants with this API.
static_assert(PR_AF_INET == AF_INET && PR_AF_INET6 == AF_INET6 &&
PR_AF_UNSPEC == AF_UNSPEC,
"PR_AF_* must match AF_*");
// If successful, returns in aResult a TTL value that is smaller or
// equal with the one already there. Gets the TTL value by calling
// to DnsQuery_A and iterating through the returned
// records to find the one with the smallest TTL value.
static MOZ_ALWAYS_INLINE nsresult _CallDnsQuery_A_Windows(
const nsACString& aHost, uint16_t aAddressFamily, DWORD aFlags,
std::function<void(PDNS_RECORDA)> aCallback) {
NS_ConvertASCIItoUTF16 name(aHost);
auto callDnsQuery_A = [&](uint16_t reqFamily) {
PDNS_RECORDA dnsData = nullptr;
DNS_STATUS status = DnsQuery_A(aHost.BeginReading(), reqFamily, aFlags,
nullptr, &dnsData, nullptr);
if (status == DNS_INFO_NO_RECORDS || status == DNS_ERROR_RCODE_NAME_ERROR ||
!dnsData) {
LOG("No DNS records found for %s. status=%lX. reqFamily = %X\n",
aHost.BeginReading(), status, reqFamily);
return NS_ERROR_FAILURE;
} else if (status != NOERROR) {
LOG_WARNING("DnsQuery_A failed with status %lX.\n", status);
return NS_ERROR_UNEXPECTED;
}
for (PDNS_RECORDA curRecord = dnsData; curRecord;
curRecord = curRecord->pNext) {
// Only records in the answer section are important
if (curRecord->Flags.S.Section != DnsSectionAnswer) {
continue;
}
if (curRecord->wType != reqFamily) {
continue;
}
aCallback(curRecord);
}
DnsFree(dnsData, DNS_FREE_TYPE::DnsFreeRecordList);
return NS_OK;
};
if (aAddressFamily == PR_AF_UNSPEC || aAddressFamily == PR_AF_INET) {
callDnsQuery_A(DNS_TYPE_A);
}
if (aAddressFamily == PR_AF_UNSPEC || aAddressFamily == PR_AF_INET6) {
callDnsQuery_A(DNS_TYPE_AAAA);
}
return NS_OK;
}
bool recordTypeMatchesRequest(uint16_t wType, uint16_t aAddressFamily) {
if (aAddressFamily == PR_AF_UNSPEC) {
return wType == DNS_TYPE_A || wType == DNS_TYPE_AAAA;
}
if (aAddressFamily == PR_AF_INET) {
return wType == DNS_TYPE_A;
}
if (aAddressFamily == PR_AF_INET6) {
return wType == DNS_TYPE_AAAA;
}
return false;
}
static MOZ_ALWAYS_INLINE nsresult _GetTTLData_Windows(const nsACString& aHost,
uint32_t* aResult,
uint16_t aAddressFamily) {
MOZ_ASSERT(!aHost.IsEmpty());
MOZ_ASSERT(aResult);
if (aAddressFamily != PR_AF_UNSPEC && aAddressFamily != PR_AF_INET &&
aAddressFamily != PR_AF_INET6) {
return NS_ERROR_UNEXPECTED;
}
// In order to avoid using ANY records which are not always implemented as a
// "Gimme what you have" request in hostname resolvers, we should send A
// and/or AAAA requests, based on the address family requested.
const DWORD ttlFlags =
(DNS_QUERY_STANDARD | DNS_QUERY_NO_NETBT | DNS_QUERY_NO_HOSTS_FILE |
DNS_QUERY_NO_MULTICAST | DNS_QUERY_ACCEPT_TRUNCATED_RESPONSE |
DNS_QUERY_DONT_RESET_TTL_VALUES);
unsigned int ttl = (unsigned int)-1;
_CallDnsQuery_A_Windows(
aHost, aAddressFamily, ttlFlags,
[&ttl, &aHost, aAddressFamily](PDNS_RECORDA curRecord) {
if (recordTypeMatchesRequest(curRecord->wType, aAddressFamily)) {
ttl = std::min<unsigned int>(ttl, curRecord->dwTtl);
} else {
LOG("Received unexpected record type %u in response for %s.\n",
curRecord->wType, aHost.BeginReading());
}
});
if (ttl == (unsigned int)-1) {
LOG("No useable TTL found.");
return NS_ERROR_FAILURE;
}
*aResult = ttl;
return NS_OK;
}
static MOZ_ALWAYS_INLINE nsresult
_DNSQuery_A_SingleLabel(const nsACString& aCanonHost, uint16_t aAddressFamily,
uint16_t aFlags, AddrInfo** aAddrInfo) {
bool setCanonName = aFlags & nsHostResolver::RES_CANON_NAME;
nsAutoCString canonName;
const DWORD flags = (DNS_QUERY_STANDARD | DNS_QUERY_NO_MULTICAST |
DNS_QUERY_ACCEPT_TRUNCATED_RESPONSE);
nsTArray<NetAddr> addresses;
_CallDnsQuery_A_Windows(
aCanonHost, aAddressFamily, flags, [&](PDNS_RECORDA curRecord) {
MOZ_DIAGNOSTIC_ASSERT(curRecord->wType == DNS_TYPE_A ||
curRecord->wType == DNS_TYPE_AAAA);
if (setCanonName) {
canonName.Assign(curRecord->pName);
}
NetAddr addr{};
addr.inet.family = AF_INET;
addr.inet.ip = curRecord->Data.A.IpAddress;
addresses.AppendElement(addr);
});
LOG("Query for: %s has %zu results", aCanonHost.BeginReading(),
addresses.Length());
if (addresses.IsEmpty()) {
return NS_ERROR_UNKNOWN_HOST;
}
RefPtr<AddrInfo> ai(new AddrInfo(
aCanonHost, canonName, DNSResolverType::Native, 0, std::move(addresses)));
ai.forget(aAddrInfo);
return NS_OK;
}
#endif
////////////////////////////////////
// PORTABLE RUNTIME IMPLEMENTATION//
////////////////////////////////////
static MOZ_ALWAYS_INLINE nsresult
_GetAddrInfo_Portable(const nsACString& aCanonHost, uint16_t aAddressFamily,
uint16_t aFlags, AddrInfo** aAddrInfo) {
MOZ_ASSERT(!aCanonHost.IsEmpty());
MOZ_ASSERT(aAddrInfo);
// We accept the same aFlags that nsHostResolver::ResolveHost accepts, but we
// need to translate the aFlags into a form that PR_GetAddrInfoByName
// accepts.
int prFlags = PR_AI_ADDRCONFIG;
if (!(aFlags & nsHostResolver::RES_CANON_NAME)) {
prFlags |= PR_AI_NOCANONNAME;
}
// We need to remove IPv4 records manually because PR_GetAddrInfoByName
// doesn't support PR_AF_INET6.
bool disableIPv4 = aAddressFamily == PR_AF_INET6;
if (disableIPv4) {
aAddressFamily = PR_AF_UNSPEC;
}
#if defined(DNSQUERY_AVAILABLE)
if (StaticPrefs::network_dns_dns_query_single_label() &&
!aCanonHost.Contains('.') && aCanonHost != "localhost"_ns) {
// For some reason we can't use DnsQuery_A to get the computer's IP.
if (!aCanonHost.Equals(nsDependentCString(sDNSComputerName),
nsCaseInsensitiveCStringComparator) &&
!aCanonHost.Equals(nsDependentCString(sNETBIOSComputerName),
nsCaseInsensitiveCStringComparator)) {
// This is a single label name resolve without a dot.
// We use DNSQuery_A for these.
LOG("Resolving %s using DnsQuery_A (computername: %s)\n",
aCanonHost.BeginReading(), sDNSComputerName);
return _DNSQuery_A_SingleLabel(aCanonHost, aAddressFamily, aFlags,
aAddrInfo);
}
}
#endif
LOG("Resolving %s using PR_GetAddrInfoByName", aCanonHost.BeginReading());
PRAddrInfo* prai =
PR_GetAddrInfoByName(aCanonHost.BeginReading(), aAddressFamily, prFlags);
if (!prai) {
LOG("PR_GetAddrInfoByName returned null PR_GetError:%d PR_GetOSErrpr:%d",
PR_GetError(), PR_GetOSError());
return NS_ERROR_UNKNOWN_HOST;
}
nsAutoCString canonName;
if (aFlags & nsHostResolver::RES_CANON_NAME) {
canonName.Assign(PR_GetCanonNameFromAddrInfo(prai));
}
bool filterNameCollision =
!(aFlags & nsHostResolver::RES_ALLOW_NAME_COLLISION);
RefPtr<AddrInfo> ai(new AddrInfo(aCanonHost, prai, disableIPv4,
filterNameCollision, canonName));
PR_FreeAddrInfo(prai);
if (ai->Addresses().IsEmpty()) {
LOG("PR_GetAddrInfoByName returned empty address list");
return NS_ERROR_UNKNOWN_HOST;
}
ai.forget(aAddrInfo);
LOG("PR_GetAddrInfoByName resolved successfully");
return NS_OK;
}
//////////////////////////////////////
// COMMON/PLATFORM INDEPENDENT CODE //
//////////////////////////////////////
nsresult GetAddrInfoInit() {
LOG("Initializing GetAddrInfo.\n");
#ifdef DNSQUERY_AVAILABLE
DWORD namesize = COMPUTER_NAME_BUFFER_SIZE;
if (!GetComputerNameExA(ComputerNameDnsHostname, sDNSComputerName,
&namesize)) {
sDNSComputerName[0] = 0;
}
namesize = MAX_COMPUTERNAME_LENGTH + 1;
if (!GetComputerNameExA(ComputerNameNetBIOS, sNETBIOSComputerName,
&namesize)) {
sNETBIOSComputerName[0] = 0;
}
#endif
return NS_OK;
}
nsresult GetAddrInfoShutdown() {
LOG("Shutting down GetAddrInfo.\n");
return NS_OK;
}
bool FindAddrOverride(const nsACString& aHost, uint16_t aAddressFamily,
uint16_t aFlags, AddrInfo** aAddrInfo) {
RefPtr<NativeDNSResolverOverride> overrideService = gOverrideService;
if (!overrideService) {
return false;
}
AutoReadLock lock(overrideService->mLock);
auto overrides = overrideService->mOverrides.Lookup(aHost);
if (!overrides) {
return false;
}
nsCString* cname = nullptr;
if (aFlags & nsHostResolver::RES_CANON_NAME) {
cname = overrideService->mCnames.Lookup(aHost).DataPtrOrNull();
}
RefPtr<AddrInfo> ai;
nsTArray<NetAddr> addresses;
for (const auto& ip : *overrides) {
if (aAddressFamily != AF_UNSPEC && ip.raw.family != aAddressFamily) {
continue;
}
addresses.AppendElement(ip);
}
if (!cname) {
ai = new AddrInfo(aHost, DNSResolverType::Native, 0, std::move(addresses));
} else {
ai = new AddrInfo(aHost, *cname, DNSResolverType::Native, 0,
std::move(addresses));
}
ai.forget(aAddrInfo);
return true;
}
nsresult GetAddrInfo(const nsACString& aHost, uint16_t aAddressFamily,
uint16_t aFlags, AddrInfo** aAddrInfo, bool aGetTtl) {
if (NS_WARN_IF(aHost.IsEmpty()) || NS_WARN_IF(!aAddrInfo)) {
return NS_ERROR_NULL_POINTER;
}
*aAddrInfo = nullptr;
if (StaticPrefs::network_dns_disabled()) {
return NS_ERROR_UNKNOWN_HOST;
}
#ifdef DNSQUERY_AVAILABLE
// The GetTTLData needs the canonical name to function properly
if (aGetTtl) {
aFlags |= nsHostResolver::RES_CANON_NAME;
}
#endif
// If there is an override for this host, then we synthetize a result.
if (gOverrideService &&
FindAddrOverride(aHost, aAddressFamily, aFlags, aAddrInfo)) {
LOG("Returning IP address from NativeDNSResolverOverride");
return (*aAddrInfo)->Addresses().Length() ? NS_OK : NS_ERROR_UNKNOWN_HOST;
}
nsAutoCString host;
if (StaticPrefs::network_dns_copy_string_before_call()) {
host = Substring(aHost.BeginReading(), aHost.Length());
MOZ_ASSERT(aHost.BeginReading() != host.BeginReading());
} else {
host = aHost;
}
if (gNativeIsLocalhost) {
// pretend we use the given host but use IPv4 localhost instead!
host = "localhost"_ns;
aAddressFamily = PR_AF_INET;
}
RefPtr<AddrInfo> info;
nsresult rv =
_GetAddrInfo_Portable(host, aAddressFamily, aFlags, getter_AddRefs(info));
#ifdef DNSQUERY_AVAILABLE
if (aGetTtl && NS_SUCCEEDED(rv)) {
// Figure out the canonical name, or if that fails, just use the host name
// we have.
nsAutoCString name;
if (info && !info->CanonicalHostname().IsEmpty()) {
name = info->CanonicalHostname();
} else {
name = host;
}
LOG("Getting TTL for %s (cname = %s).", host.get(), name.get());
uint32_t ttl = 0;
nsresult ttlRv = _GetTTLData_Windows(name, &ttl, aAddressFamily);
if (NS_SUCCEEDED(ttlRv)) {
auto builder = info->Build();
builder.SetTTL(ttl);
info = builder.Finish();
LOG("Got TTL %u for %s (name = %s).", ttl, host.get(), name.get());
} else {
LOG_WARNING("Could not get TTL for %s (cname = %s).", host.get(),
name.get());
}
}
#endif
info.forget(aAddrInfo);
return rv;
}
bool FindHTTPSRecordOverride(const nsACString& aHost,
TypeRecordResultType& aResult) {
LOG("FindHTTPSRecordOverride aHost=%s", nsCString(aHost).get());
RefPtr<NativeDNSResolverOverride> overrideService = gOverrideService;
if (!overrideService) {
return false;
}
AutoReadLock lock(overrideService->mLock);
auto overrides = overrideService->mHTTPSRecordOverrides.Lookup(aHost);
if (!overrides) {
return false;
}
DNSPacket packet;
nsAutoCString host(aHost);
nsAutoCString cname;
LOG("resolving %s\n", host.get());
// Perform the query
nsresult rv = packet.FillBuffer(
[&](unsigned char response[DNSPacket::MAX_SIZE]) -> int {
if (overrides->Length() > DNSPacket::MAX_SIZE) {
return -1;
}
memcpy(response, overrides->Elements(), overrides->Length());
return overrides->Length();
});
if (NS_FAILED(rv)) {
return false;
}
uint32_t ttl = 0;
rv = ParseHTTPSRecord(host, packet, aResult, ttl);
return NS_SUCCEEDED(rv);
}
nsresult ParseHTTPSRecord(nsCString& aHost, DNSPacket& aDNSPacket,
TypeRecordResultType& aResult, uint32_t& aTTL) {
nsAutoCString cname;
nsresult rv;
aDNSPacket.SetNativePacket(true);
int32_t loopCount = 64;
while (loopCount > 0 && aResult.is<Nothing>()) {
loopCount--;
DOHresp resp;
nsClassHashtable<nsCStringHashKey, DOHresp> additionalRecords;
rv = aDNSPacket.Decode(aHost, TRRTYPE_HTTPSSVC, cname, true, resp, aResult,
additionalRecords, aTTL);
if (NS_FAILED(rv)) {
LOG("Decode failed %x", static_cast<uint32_t>(rv));
return rv;
}
if (!cname.IsEmpty() && aResult.is<Nothing>()) {
aHost = cname;
cname.Truncate();
continue;
}
}
if (aResult.is<Nothing>()) {
LOG("Result is nothing");
// The call succeeded, but no HTTPS records were found.
return NS_ERROR_UNKNOWN_HOST;
}
return NS_OK;
}
nsresult ResolveHTTPSRecord(const nsACString& aHost, uint16_t aFlags,
TypeRecordResultType& aResult, uint32_t& aTTL) {
if (gOverrideService) {
return FindHTTPSRecordOverride(aHost, aResult) ? NS_OK
: NS_ERROR_UNKNOWN_HOST;
}
return ResolveHTTPSRecordImpl(aHost, aFlags, aResult, aTTL);
}
// static
already_AddRefed<nsINativeDNSResolverOverride>
NativeDNSResolverOverride::GetSingleton() {
if (nsIOService::UseSocketProcess() && XRE_IsParentProcess()) {
return NativeDNSResolverOverrideParent::GetSingleton();
}
if (gOverrideService) {
return do_AddRef(gOverrideService);
}
gOverrideService = new NativeDNSResolverOverride();
ClearOnShutdown(&gOverrideService);
return do_AddRef(gOverrideService);
}
NS_IMPL_ISUPPORTS(NativeDNSResolverOverride, nsINativeDNSResolverOverride)
NS_IMETHODIMP NativeDNSResolverOverride::AddIPOverride(
const nsACString& aHost, const nsACString& aIPLiteral) {
NetAddr tempAddr;
if (aIPLiteral.Equals("N/A"_ns)) {
AutoWriteLock lock(mLock);
auto& overrides = mOverrides.LookupOrInsert(aHost);
overrides.Clear();
return NS_OK;
}
if (NS_FAILED(tempAddr.InitFromString(aIPLiteral))) {
return NS_ERROR_UNEXPECTED;
}
AutoWriteLock lock(mLock);
auto& overrides = mOverrides.LookupOrInsert(aHost);
overrides.AppendElement(tempAddr);
return NS_OK;
}
NS_IMETHODIMP NativeDNSResolverOverride::AddHTTPSRecordOverride(
const nsACString& aHost, const uint8_t* aData, uint32_t aLength) {
AutoWriteLock lock(mLock);
nsTArray<uint8_t> data(aData, aLength);
mHTTPSRecordOverrides.InsertOrUpdate(aHost, std::move(data));
return NS_OK;
}
NS_IMETHODIMP NativeDNSResolverOverride::SetCnameOverride(
const nsACString& aHost, const nsACString& aCNAME) {
if (aCNAME.IsEmpty()) {
return NS_ERROR_UNEXPECTED;
}
AutoWriteLock lock(mLock);
mCnames.InsertOrUpdate(aHost, nsCString(aCNAME));
return NS_OK;
}
NS_IMETHODIMP NativeDNSResolverOverride::ClearHostOverride(
const nsACString& aHost) {
AutoWriteLock lock(mLock);
mCnames.Remove(aHost);
auto overrides = mOverrides.Extract(aHost);
if (!overrides) {
return NS_OK;
}
overrides->Clear();
return NS_OK;
}
NS_IMETHODIMP NativeDNSResolverOverride::ClearOverrides() {
AutoWriteLock lock(mLock);
mOverrides.Clear();
mCnames.Clear();
return NS_OK;
}
#ifdef MOZ_NO_HTTPS_IMPL
// If there is no platform specific implementation of ResolveHTTPSRecordImpl
// we link a dummy implementation here.
// Otherwise this is implemented in GetAddrInfoWin/Linux/etc
nsresult ResolveHTTPSRecordImpl(const nsACString& aHost, uint16_t aFlags,
TypeRecordResultType& aResult, uint32_t& aTTL) {
return NS_ERROR_NOT_IMPLEMENTED;
}
void DNSThreadShutdown() {}
#endif // MOZ_NO_HTTPS_IMPL
} // namespace mozilla::net