netwerk/dns/PlatformDNSWin.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=4 sw=2 sts=2 et cin: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "GetAddrInfo.h"
   8 #include "mozilla/net/DNSPacket.h"
   9 #include "nsIDNSService.h"
  10 #include "mozilla/Maybe.h"
  11 #include "mozilla/ScopeExit.h"
  12 #include "mozilla/StaticPrefs_network.h"
  13
  14 #ifdef DNSQUERY_AVAILABLE
  15 // There is a bug in windns.h where the type of parameter ppQueryResultsSet for
  16 // DnsQuery_A is dependent on UNICODE being set. It should *always* be
  17 // PDNS_RECORDA, but if UNICODE is set it is PDNS_RECORDW. To get around this
  18 // we make sure that UNICODE is unset.
  19 #  undef UNICODE
  20 #  include <ws2tcpip.h>
  21 #  undef GetAddrInfo
  22 #  include <windns.h>
  23 #endif  // DNSQUERY_AVAILABLE
  24
  25 namespace mozilla::net {
  26
  27 #define LOG(msg, ...) \
  28   MOZ_LOG(gGetAddrInfoLog, LogLevel::Debug, ("[DNS]: " msg, ##__VA_ARGS__))
  29
  30 nsresult ResolveHTTPSRecordImpl(const nsACString& aHost, uint16_t aFlags,
  31                                 TypeRecordResultType& aResult, uint32_t& aTTL) {
  32   nsAutoCString host(aHost);
  33   PDNS_RECORD result = nullptr;
  34   nsAutoCString cname;
  35   aTTL = UINT32_MAX;
  36
  37   if (xpc::IsInAutomation() &&
  38       !StaticPrefs::network_dns_native_https_query_in_automation()) {
  39     return NS_ERROR_UNKNOWN_HOST;
  40   }
  41
  42   DNS_STATUS status =
  43       DnsQuery_A(host.get(), nsIDNSService::RESOLVE_TYPE_HTTPSSVC,
  44                  DNS_QUERY_STANDARD, nullptr, &result, nullptr);
  45   if (status != ERROR_SUCCESS) {
  46     LOG("DnsQuery_A failed with error: %ld\n", status);
  47     return NS_ERROR_UNKNOWN_HOST;
  48   }
  49
  50   // This will free the record if we exit early from this function.
  51   auto freeDnsRecord =
  52       MakeScopeExit([&]() { DnsRecordListFree(result, DnsFreeRecordList); });
  53
  54   auto CheckRecords = [&aResult, &cname, &aTTL](
  55                           PDNS_RECORD result,
  56                           const nsCString& aHost) -> nsresult {
  57     PDNS_RECORD current = result;
  58
  59     for (current = result; current; current = current->pNext) {
  60       if (strcmp(current->pName, aHost.get()) != 0) {
  61         continue;
  62       }
  63       if (current->wType == nsIDNSService::RESOLVE_TYPE_HTTPSSVC) {
  64         const unsigned char* ptr = (const unsigned char*)&(current->Data);
  65         struct SVCB parsed;
  66         nsresult rv = DNSPacket::ParseHTTPS(current->wDataLength, parsed, 0,
  67                                             ptr, current->wDataLength, aHost);
  68         if (NS_FAILED(rv)) {
  69           return rv;
  70         }
  71
  72         if (parsed.mSvcDomainName.IsEmpty() && parsed.mSvcFieldPriority == 0) {
  73           // For AliasMode SVCB RRs, a TargetName of "." indicates that the
  74           // service is not available or does not exist.
  75           continue;
  76         }
  77
  78         if (parsed.mSvcFieldPriority == 0) {
  79           // Alias form SvcDomainName must not have the "." value (empty)
  80           if (parsed.mSvcDomainName.IsEmpty()) {
  81             return NS_ERROR_UNEXPECTED;
  82           }
  83           cname = parsed.mSvcDomainName;
  84           ToLowerCase(cname);
  85           break;
  86         }
  87
  88         if (!aResult.is<TypeRecordHTTPSSVC>()) {
  89           aResult = mozilla::AsVariant(CopyableTArray<SVCB>());
  90         }
  91         auto& results = aResult.as<TypeRecordHTTPSSVC>();
  92         results.AppendElement(parsed);
  93         aTTL = std::min<uint32_t>(aTTL, current->dwTtl);
  94       } else if (current->wType == DNS_TYPE_CNAME) {
  95         cname = current->Data.Cname.pNameHost;
  96         ToLowerCase(cname);
  97         aTTL = std::min<uint32_t>(aTTL, current->dwTtl);
  98         break;
  99       }
 100     }
 101     return NS_OK;
 102   };
 103
 104   int32_t loopCount = 64;
 105   while (loopCount > 0 && aResult.is<Nothing>()) {
 106     loopCount--;
 107
 108     nsresult rv = CheckRecords(result, host);
 109     if (NS_FAILED(rv)) {
 110       return rv;
 111     }
 112
 113     if (aResult.is<Nothing>() && !cname.IsEmpty()) {
 114       host = cname;
 115       cname.Truncate();
 116       continue;
 117     }
 118
 119     if (aResult.is<Nothing>()) {
 120       return NS_ERROR_UNKNOWN_HOST;
 121     }
 122   }
 123
 124   // CNAME loop
 125   if (loopCount == 0) {
 126     return NS_ERROR_UNKNOWN_HOST;
 127   }
 128
 129   if (aResult.is<Nothing>()) {
 130     // The call succeeded, but no HTTPS records were found.
 131     return NS_ERROR_UNKNOWN_HOST;
 132   }
 133
 134   if (aTTL == UINT32_MAX) {
 135     aTTL = 60;  // Defaults to 60 seconds
 136   }
 137   return NS_OK;
 138 }
 139
 140 void DNSThreadShutdown() {}
 141
 142 }  // namespace mozilla::net