The Tor Browser: netwerk/base/src/ProxyAutoConfig.cpp@b8a032363ba2 (annotated)

netwerk/base/src/ProxyAutoConfig.cpp@b8a032363ba2 (annotated)

netwerk/base/src/ProxyAutoConfig.cpp

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim:set ts=2 sw=2 sts=2 et cindent: */
 /* 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 "ProxyAutoConfig.h"
 #include "nsICancelable.h"
 #include "nsIDNSListener.h"
 #include "nsIDNSRecord.h"
 #include "nsIDNSService.h"
 #include "nsThreadUtils.h"
 #include "nsIConsoleService.h"
 #include "nsJSUtils.h"
 #include "jsfriendapi.h"
 #include "prnetdb.h"
 #include "nsITimer.h"
 #include "mozilla/net/DNS.h"
 #include "nsServiceManagerUtils.h"
 #include "nsNetCID.h"
 namespace mozilla {
 namespace net {
 // These are some global helper symbols the PAC format requires that we provide that
 // are initialized as part of the global javascript context used for PAC evaluations.
 // Additionally dnsResolve(host) and myIpAddress() are supplied in the same context
 // but are implemented as c++ helpers. alert(msg) is similarly defined.
 static const char *sPacUtils =
   "function dnsDomainIs(host, domain) {\n"
   "    return (host.length >= domain.length &&\n"
   "            host.substring(host.length - domain.length) == domain);\n"
   "}\n"
   ""
   "function dnsDomainLevels(host) {\n"
   "    return host.split('.').length - 1;\n"
   "}\n"
   ""
   "function convert_addr(ipchars) {\n"
   "    var bytes = ipchars.split('.');\n"
   "    var result = ((bytes[0] & 0xff) << 24) |\n"
   "                 ((bytes[1] & 0xff) << 16) |\n"
   "                 ((bytes[2] & 0xff) <<  8) |\n"
   "                  (bytes[3] & 0xff);\n"
   "    return result;\n"
   "}\n"
   ""
   "function isInNet(ipaddr, pattern, maskstr) {\n"
   "    var test = /^(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})$/.exec(ipaddr);\n"
   "    if (test == null) {\n"
   "        ipaddr = dnsResolve(ipaddr);\n"
   "        if (ipaddr == null)\n"
   "            return false;\n"
   "    } else if (test[1] > 255 || test[2] > 255 || \n"
   "               test[3] > 255 || test[4] > 255) {\n"
   "        return false;    // not an IP address\n"
   "    }\n"
   "    var host = convert_addr(ipaddr);\n"
   "    var pat  = convert_addr(pattern);\n"
   "    var mask = convert_addr(maskstr);\n"
   "    return ((host & mask) == (pat & mask));\n"
   "    \n"
   "}\n"
   ""
   "function isPlainHostName(host) {\n"
   "    return (host.search('\\\\.') == -1);\n"
   "}\n"
   ""
   "function isResolvable(host) {\n"
   "    var ip = dnsResolve(host);\n"
   "    return (ip != null);\n"
   "}\n"
   ""
   "function localHostOrDomainIs(host, hostdom) {\n"
   "    return (host == hostdom) ||\n"
   "           (hostdom.lastIndexOf(host + '.', 0) == 0);\n"
   "}\n"
   ""
   "function shExpMatch(url, pattern) {\n"
   "   pattern = pattern.replace(/\\./g, '\\\\.');\n"
   "   pattern = pattern.replace(/\\*/g, '.*');\n"
   "   pattern = pattern.replace(/\\?/g, '.');\n"
   "   var newRe = new RegExp('^'+pattern+'$');\n"
   "   return newRe.test(url);\n"
   "}\n"
   ""
   "var wdays = {SUN: 0, MON: 1, TUE: 2, WED: 3, THU: 4, FRI: 5, SAT: 6};\n"
   "var months = {JAN: 0, FEB: 1, MAR: 2, APR: 3, MAY: 4, JUN: 5, JUL: 6, AUG: 7, SEP: 8, OCT: 9, NOV: 10, DEC: 11};\n"
   ""
   "function weekdayRange() {\n"
   "    function getDay(weekday) {\n"
   "        if (weekday in wdays) {\n"
   "            return wdays[weekday];\n"
   "        }\n"
   "        return -1;\n"
   "    }\n"
   "    var date = new Date();\n"
   "    var argc = arguments.length;\n"
   "    var wday;\n"
   "    if (argc < 1)\n"
   "        return false;\n"
   "    if (arguments[argc - 1] == 'GMT') {\n"
   "        argc--;\n"
   "        wday = date.getUTCDay();\n"
   "    } else {\n"
   "        wday = date.getDay();\n"
   "    }\n"
   "    var wd1 = getDay(arguments[0]);\n"
   "    var wd2 = (argc == 2) ? getDay(arguments[1]) : wd1;\n"
   "    return (wd1 == -1 || wd2 == -1) ? false\n"
   "                                    : (wd1 <= wday && wday <= wd2);\n"
   "}\n"
   ""
   "function dateRange() {\n"
   "    function getMonth(name) {\n"
   "        if (name in months) {\n"
   "            return months[name];\n"
   "        }\n"
   "        return -1;\n"
   "    }\n"
   "    var date = new Date();\n"
   "    var argc = arguments.length;\n"
   "    if (argc < 1) {\n"
   "        return false;\n"
   "    }\n"
   "    var isGMT = (arguments[argc - 1] == 'GMT');\n"
   "\n"
   "    if (isGMT) {\n"
   "        argc--;\n"
   "    }\n"
   "    // function will work even without explict handling of this case\n"
   "    if (argc == 1) {\n"
   "        var tmp = parseInt(arguments[0]);\n"
   "        if (isNaN(tmp)) {\n"
   "            return ((isGMT ? date.getUTCMonth() : date.getMonth()) ==\n"
   "                     getMonth(arguments[0]));\n"
   "        } else if (tmp < 32) {\n"
   "            return ((isGMT ? date.getUTCDate() : date.getDate()) == tmp);\n"
   "        } else { \n"
   "            return ((isGMT ? date.getUTCFullYear() : date.getFullYear()) ==\n"
   "                     tmp);\n"
   "        }\n"
   "    }\n"
   "    var year = date.getFullYear();\n"
   "    var date1, date2;\n"
   "    date1 = new Date(year,  0,  1,  0,  0,  0);\n"
   "    date2 = new Date(year, 11, 31, 23, 59, 59);\n"
   "    var adjustMonth = false;\n"
   "    for (var i = 0; i < (argc >> 1); i++) {\n"
   "        var tmp = parseInt(arguments[i]);\n"
   "        if (isNaN(tmp)) {\n"
   "            var mon = getMonth(arguments[i]);\n"
   "            date1.setMonth(mon);\n"
   "        } else if (tmp < 32) {\n"
   "            adjustMonth = (argc <= 2);\n"
   "            date1.setDate(tmp);\n"
   "        } else {\n"
   "            date1.setFullYear(tmp);\n"
   "        }\n"
   "    }\n"
   "    for (var i = (argc >> 1); i < argc; i++) {\n"
   "        var tmp = parseInt(arguments[i]);\n"
   "        if (isNaN(tmp)) {\n"
   "            var mon = getMonth(arguments[i]);\n"
   "            date2.setMonth(mon);\n"
   "        } else if (tmp < 32) {\n"
   "            date2.setDate(tmp);\n"
   "        } else {\n"
   "            date2.setFullYear(tmp);\n"
   "        }\n"
   "    }\n"
   "    if (adjustMonth) {\n"
   "        date1.setMonth(date.getMonth());\n"
   "        date2.setMonth(date.getMonth());\n"
   "    }\n"
   "    if (isGMT) {\n"
   "    var tmp = date;\n"
   "        tmp.setFullYear(date.getUTCFullYear());\n"
   "        tmp.setMonth(date.getUTCMonth());\n"
   "        tmp.setDate(date.getUTCDate());\n"
   "        tmp.setHours(date.getUTCHours());\n"
   "        tmp.setMinutes(date.getUTCMinutes());\n"
   "        tmp.setSeconds(date.getUTCSeconds());\n"
   "        date = tmp;\n"
   "    }\n"
   "    return ((date1 <= date) && (date <= date2));\n"
   "}\n"
   ""
   "function timeRange() {\n"
   "    var argc = arguments.length;\n"
   "    var date = new Date();\n"
   "    var isGMT= false;\n"
   ""
   "    if (argc < 1) {\n"
   "        return false;\n"
   "    }\n"
   "    if (arguments[argc - 1] == 'GMT') {\n"
   "        isGMT = true;\n"
   "        argc--;\n"
   "    }\n"
   "\n"
   "    var hour = isGMT ? date.getUTCHours() : date.getHours();\n"
   "    var date1, date2;\n"
   "    date1 = new Date();\n"
   "    date2 = new Date();\n"
   "\n"
   "    if (argc == 1) {\n"
   "        return (hour == arguments[0]);\n"
   "    } else if (argc == 2) {\n"
   "        return ((arguments[0] <= hour) && (hour <= arguments[1]));\n"
   "    } else {\n"
   "        switch (argc) {\n"
   "        case 6:\n"
   "            date1.setSeconds(arguments[2]);\n"
   "            date2.setSeconds(arguments[5]);\n"
   "        case 4:\n"
   "            var middle = argc >> 1;\n"
   "            date1.setHours(arguments[0]);\n"
   "            date1.setMinutes(arguments[1]);\n"
   "            date2.setHours(arguments[middle]);\n"
   "            date2.setMinutes(arguments[middle + 1]);\n"
   "            if (middle == 2) {\n"
   "                date2.setSeconds(59);\n"
   "            }\n"
   "            break;\n"
   "        default:\n"
   "          throw 'timeRange: bad number of arguments'\n"
   "        }\n"
   "    }\n"
   "\n"
   "    if (isGMT) {\n"
   "        date.setFullYear(date.getUTCFullYear());\n"
   "        date.setMonth(date.getUTCMonth());\n"
   "        date.setDate(date.getUTCDate());\n"
   "        date.setHours(date.getUTCHours());\n"
   "        date.setMinutes(date.getUTCMinutes());\n"
   "        date.setSeconds(date.getUTCSeconds());\n"
   "    }\n"
   "    return ((date1 <= date) && (date <= date2));\n"
   "}\n"
   "";
 // sRunning is defined for the helper functions only while the
 // Javascript engine is running and the PAC object cannot be deleted
 // or reset.
 static ProxyAutoConfig *sRunning = nullptr;
 // The PACResolver is used for dnsResolve()
 class PACResolver MOZ_FINAL : public nsIDNSListener
                             , public nsITimerCallback
 {
 public:
   NS_DECL_THREADSAFE_ISUPPORTS
   PACResolver()
     : mStatus(NS_ERROR_FAILURE)
   {
   }
   // nsIDNSListener
   NS_IMETHODIMP OnLookupComplete(nsICancelable *request,
                                  nsIDNSRecord *record,
                                  nsresult status)
   {
     if (mTimer) {
       mTimer->Cancel();
       mTimer = nullptr;
     }
     mRequest = nullptr;
     mStatus = status;
     mResponse = record;
     return NS_OK;
   }
   // nsITimerCallback
   NS_IMETHODIMP Notify(nsITimer *timer)
   {
     if (mRequest)
       mRequest->Cancel(NS_ERROR_NET_TIMEOUT);
     mTimer = nullptr;
     return NS_OK;
   }
   nsresult                mStatus;
   nsCOMPtr<nsICancelable> mRequest;
   nsCOMPtr<nsIDNSRecord>  mResponse;
   nsCOMPtr<nsITimer>      mTimer;
 };
 NS_IMPL_ISUPPORTS(PACResolver, nsIDNSListener, nsITimerCallback)
 static
 void PACLogToConsole(nsString &aMessage)
 {
   nsCOMPtr<nsIConsoleService> consoleService =
     do_GetService(NS_CONSOLESERVICE_CONTRACTID);
   if (!consoleService)
     return;
   consoleService->LogStringMessage(aMessage.get());
 }
 // Javascript errors are logged to the main error console
 static void
 PACErrorReporter(JSContext *cx, const char *message, JSErrorReport *report)
 {
   nsString formattedMessage(NS_LITERAL_STRING("PAC Execution Error: "));
   formattedMessage += report->ucmessage;
   formattedMessage += NS_LITERAL_STRING(" [");
   formattedMessage += report->uclinebuf;
   formattedMessage += NS_LITERAL_STRING("]");
   PACLogToConsole(formattedMessage);
 }
 // timeout of 0 means the normal necko timeout strategy, otherwise the dns request
 // will be canceled after aTimeout milliseconds
 static
 bool PACResolve(const nsCString &aHostName, NetAddr *aNetAddr,
                 unsigned int aTimeout)
 {
   if (!sRunning) {
     NS_WARNING("PACResolve without a running ProxyAutoConfig object");
     return false;
   }
   return sRunning->ResolveAddress(aHostName, aNetAddr, aTimeout);
 }
 ProxyAutoConfig::ProxyAutoConfig()
   : mJSRuntime(nullptr)
   , mJSNeedsSetup(false)
   , mShutdown(false)
 {
   MOZ_COUNT_CTOR(ProxyAutoConfig);
 }
 bool
 ProxyAutoConfig::ResolveAddress(const nsCString &aHostName,
                                 NetAddr *aNetAddr,
                                 unsigned int aTimeout)
 {
   nsCOMPtr<nsIDNSService> dns = do_GetService(NS_DNSSERVICE_CONTRACTID);
   if (!dns)
     return false;
   nsRefPtr<PACResolver> helper = new PACResolver();
   if (NS_FAILED(dns->AsyncResolve(aHostName,
                                   nsIDNSService::RESOLVE_PRIORITY_MEDIUM,
                                   helper,
                                   NS_GetCurrentThread(),
                                   getter_AddRefs(helper->mRequest))))
     return false;
   if (aTimeout && helper->mRequest) {
     if (!mTimer)
       mTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
     if (mTimer) {
       mTimer->InitWithCallback(helper, aTimeout, nsITimer::TYPE_ONE_SHOT);
       helper->mTimer = mTimer;
     }
   }
   // Spin the event loop of the pac thread until lookup is complete.
   // nsPACman is responsible for keeping a queue and only allowing
   // one PAC execution at a time even when it is called re-entrantly.
   while (helper->mRequest)
     NS_ProcessNextEvent(NS_GetCurrentThread());
   if (NS_FAILED(helper->mStatus) ||
       NS_FAILED(helper->mResponse->GetNextAddr(0, aNetAddr)))
     return false;
   return true;
 }
 static
 bool PACResolveToString(const nsCString &aHostName,
                         nsCString &aDottedDecimal,
                         unsigned int aTimeout)
 {
   NetAddr netAddr;
   if (!PACResolve(aHostName, &netAddr, aTimeout))
     return false;
   char dottedDecimal[128];
   if (!NetAddrToString(&netAddr, dottedDecimal, sizeof(dottedDecimal)))
     return false;
   aDottedDecimal.Assign(dottedDecimal);
   return true;
 }
 // dnsResolve(host) javascript implementation
 static
 bool PACDnsResolve(JSContext *cx, unsigned int argc, JS::Value *vp)
 {
   JS::CallArgs args = CallArgsFromVp(argc, vp);
   if (NS_IsMainThread()) {
     NS_WARNING("DNS Resolution From PAC on Main Thread. How did that happen?");
     return false;
   }
   JS::Rooted<JSString*> arg1(cx);
   if (!JS_ConvertArguments(cx, args, "S", arg1.address()))
     return false;
   nsDependentJSString hostName;
   nsAutoCString dottedDecimal;
   if (!hostName.init(cx, arg1))
     return false;
   if (PACResolveToString(NS_ConvertUTF16toUTF8(hostName), dottedDecimal, 0)) {
     JSString *dottedDecimalString = JS_NewStringCopyZ(cx, dottedDecimal.get());
     if (!dottedDecimalString) {
       return false;
     }
     args.rval().setString(dottedDecimalString);
   }
   else {
     args.rval().setNull();
   }
   return true;
 }
 // myIpAddress() javascript implementation
 static
 bool PACMyIpAddress(JSContext *cx, unsigned int argc, JS::Value *vp)
 {
   JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
   if (NS_IsMainThread()) {
     NS_WARNING("DNS Resolution From PAC on Main Thread. How did that happen?");
     return false;
   }
   if (!sRunning) {
     NS_WARNING("PAC myIPAddress without a running ProxyAutoConfig object");
     return false;
   }
   return sRunning->MyIPAddress(args);
 }
 // proxyAlert(msg) javascript implementation
 static
 bool PACProxyAlert(JSContext *cx, unsigned int argc, JS::Value *vp)
 {
   JS::CallArgs args = CallArgsFromVp(argc, vp);
   JS::Rooted<JSString*> arg1(cx);
   if (!JS_ConvertArguments(cx, args, "S", arg1.address()))
     return false;
   nsDependentJSString message;
   if (!message.init(cx, arg1))
     return false;
   nsString alertMessage;
   alertMessage.SetCapacity(32 + message.Length());
   alertMessage += NS_LITERAL_STRING("PAC-alert: ");
   alertMessage += message;
   PACLogToConsole(alertMessage);
   args.rval().setUndefined();  /* return undefined */
   return true;
 }
 static const JSFunctionSpec PACGlobalFunctions[] = {
   JS_FS("dnsResolve", PACDnsResolve, 1, 0),
   JS_FS("myIpAddress", PACMyIpAddress, 0, 0),
   JS_FS("alert", PACProxyAlert, 1, 0),
   JS_FS_END
 };
 // JSRuntimeWrapper is a c++ object that manages the runtime and context
 // for the JS engine used on the PAC thread. It is initialized and destroyed
 // on the PAC thread.
 class JSRuntimeWrapper
 {
  public:
   static JSRuntimeWrapper *Create()
   {
     JSRuntimeWrapper *entry = new JSRuntimeWrapper();
     if (NS_FAILED(entry->Init())) {
       delete entry;
       return nullptr;
     }
     return entry;
   }
   JSContext *Context() const
   {
     return mContext;
   }
   JSObject *Global() const
   {
     return mGlobal;
   }
   ~JSRuntimeWrapper()
   {
     MOZ_COUNT_DTOR(JSRuntimeWrapper);
     if (mContext) {
       JS_DestroyContext(mContext);
     }
     if (mRuntime) {
       JS_DestroyRuntime(mRuntime);
     }
   }
   void SetOK()
   {
     mOK = true;
   }
   bool IsOK()
   {
     return mOK;
   }
 private:
   static const unsigned sRuntimeHeapSize = 2 << 20;
   JSRuntime *mRuntime;
   JSContext *mContext;
   JSObject  *mGlobal;
   bool      mOK;
   static const JSClass sGlobalClass;
   JSRuntimeWrapper()
     : mRuntime(nullptr), mContext(nullptr), mGlobal(nullptr), mOK(false)
   {
       MOZ_COUNT_CTOR(JSRuntimeWrapper);
   }
   nsresult Init()
   {
     mRuntime = JS_NewRuntime(sRuntimeHeapSize, JS_NO_HELPER_THREADS);
     NS_ENSURE_TRUE(mRuntime, NS_ERROR_OUT_OF_MEMORY);
     /*
      * Not setting this will cause JS_CHECK_RECURSION to report false
      * positives
      */
     JS_SetNativeStackQuota(mRuntime, 128 * sizeof(size_t) * 1024);
     mContext = JS_NewContext(mRuntime, 0);
     NS_ENSURE_TRUE(mContext, NS_ERROR_OUT_OF_MEMORY);
     JSAutoRequest ar(mContext);
     JS::CompartmentOptions options;
     options.setZone(JS::SystemZone)
            .setVersion(JSVERSION_LATEST);
     mGlobal = JS_NewGlobalObject(mContext, &sGlobalClass, nullptr,
                                  JS::DontFireOnNewGlobalHook, options);
     NS_ENSURE_TRUE(mGlobal, NS_ERROR_OUT_OF_MEMORY);
     JS::Rooted<JSObject*> global(mContext, mGlobal);
     JSAutoCompartment ac(mContext, global);
     js::SetDefaultObjectForContext(mContext, global);
     JS_InitStandardClasses(mContext, global);
     JS_SetErrorReporter(mContext, PACErrorReporter);
     if (!JS_DefineFunctions(mContext, global, PACGlobalFunctions))
       return NS_ERROR_FAILURE;
     JS_FireOnNewGlobalObject(mContext, global);
     return NS_OK;
   }
 };
 const JSClass JSRuntimeWrapper::sGlobalClass = {
   "PACResolutionThreadGlobal",
   JSCLASS_GLOBAL_FLAGS,
   JS_PropertyStub, JS_DeletePropertyStub, JS_PropertyStub, JS_StrictPropertyStub,
   JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub,
   nullptr, nullptr, nullptr, nullptr,
   JS_GlobalObjectTraceHook
 };
 nsresult
 ProxyAutoConfig::Init(const nsCString &aPACURI,
                       const nsCString &aPACScript)
 {
   mPACURI = aPACURI;
   mPACScript = sPacUtils;
   mPACScript.Append(aPACScript);
   if (!sRunning)
     return SetupJS();
   mJSNeedsSetup = true;
   return NS_OK;
 }
 nsresult
 ProxyAutoConfig::SetupJS()
 {
   mJSNeedsSetup = false;
   NS_ABORT_IF_FALSE(!sRunning, "JIT is running");
   delete mJSRuntime;
   mJSRuntime = nullptr;
   if (mPACScript.IsEmpty())
     return NS_ERROR_FAILURE;
   mJSRuntime = JSRuntimeWrapper::Create();
   if (!mJSRuntime)
     return NS_ERROR_FAILURE;
   JSContext* cx = mJSRuntime->Context();
   JSAutoRequest ar(cx);
   JSAutoCompartment ac(cx, mJSRuntime->Global());
   // check if this is a data: uri so that we don't spam the js console with
   // huge meaningless strings. this is not on the main thread, so it can't
   // use nsIRUI scheme methods
   bool isDataURI = nsDependentCSubstring(mPACURI, 0, 5).LowerCaseEqualsASCII("data:", 5);
   sRunning = this;
   JS::Rooted<JSObject*> global(cx, mJSRuntime->Global());
   JS::CompileOptions options(cx);
   options.setFileAndLine(mPACURI.get(), 1);
   JS::Rooted<JSScript*> script(cx, JS_CompileScript(cx, global, mPACScript.get(),
                                                     mPACScript.Length(), options));
   if (!script || !JS_ExecuteScript(cx, global, script)) {
     nsString alertMessage(NS_LITERAL_STRING("PAC file failed to install from "));
     if (isDataURI) {
       alertMessage += NS_LITERAL_STRING("data: URI");
     }
     else {
       alertMessage += NS_ConvertUTF8toUTF16(mPACURI);
     }
     PACLogToConsole(alertMessage);
     sRunning = nullptr;
     return NS_ERROR_FAILURE;
   }
   sRunning = nullptr;
   mJSRuntime->SetOK();
   nsString alertMessage(NS_LITERAL_STRING("PAC file installed from "));
   if (isDataURI) {
     alertMessage += NS_LITERAL_STRING("data: URI");
   }
   else {
     alertMessage += NS_ConvertUTF8toUTF16(mPACURI);
   }
   PACLogToConsole(alertMessage);
   // we don't need these now
   mPACScript.Truncate();
   mPACURI.Truncate();
   return NS_OK;
 }
 nsresult
 ProxyAutoConfig::GetProxyForURI(const nsCString &aTestURI,
                                 const nsCString &aTestHost,
                                 nsACString &result)
 {
   if (mJSNeedsSetup)
     SetupJS();
   if (!mJSRuntime || !mJSRuntime->IsOK())
     return NS_ERROR_NOT_AVAILABLE;
   JSContext *cx = mJSRuntime->Context();
   JSAutoRequest ar(cx);
   JSAutoCompartment ac(cx, mJSRuntime->Global());
   // the sRunning flag keeps a new PAC file from being installed
   // while the event loop is spinning on a DNS function. Don't early return.
   sRunning = this;
   mRunningHost = aTestHost;
   nsresult rv = NS_ERROR_FAILURE;
   JS::RootedString uriString(cx, JS_NewStringCopyZ(cx, aTestURI.get()));
   JS::RootedString hostString(cx, JS_NewStringCopyZ(cx, aTestHost.get()));
   if (uriString && hostString) {
     JS::AutoValueArray<2> args(cx);
     args[0].setString(uriString);
     args[1].setString(hostString);
     JS::Rooted<JS::Value> rval(cx);
     JS::Rooted<JSObject*> global(cx, mJSRuntime->Global());
     bool ok = JS_CallFunctionName(cx, global, "FindProxyForURL", args, &rval);
     if (ok && rval.isString()) {
       nsDependentJSString pacString;
       if (pacString.init(cx, rval.toString())) {
         CopyUTF16toUTF8(pacString, result);
         rv = NS_OK;
       }
     }
   }
   mRunningHost.Truncate();
   sRunning = nullptr;
   return rv;
 }
 void
 ProxyAutoConfig::GC()
 {
   if (!mJSRuntime || !mJSRuntime->IsOK())
     return;
   JSAutoCompartment ac(mJSRuntime->Context(), mJSRuntime->Global());
   JS_MaybeGC(mJSRuntime->Context());
 }
 ProxyAutoConfig::~ProxyAutoConfig()
 {
   MOZ_COUNT_DTOR(ProxyAutoConfig);
   NS_ASSERTION(!mJSRuntime,
                "~ProxyAutoConfig leaking JS runtime that "
                "should have been deleted on pac thread");
 }
 void
 ProxyAutoConfig::Shutdown()
 {
   NS_ABORT_IF_FALSE(!NS_IsMainThread(), "wrong thread for shutdown");
   if (sRunning || mShutdown)
     return;
   mShutdown = true;
   delete mJSRuntime;
   mJSRuntime = nullptr;
 }
 bool
 ProxyAutoConfig::SrcAddress(const NetAddr *remoteAddress, nsCString &localAddress)
 {
   PRFileDesc *fd;
   fd = PR_OpenUDPSocket(remoteAddress->raw.family);
   if (!fd)
     return false;
   PRNetAddr prRemoteAddress;
   NetAddrToPRNetAddr(remoteAddress, &prRemoteAddress);
   if (PR_Connect(fd, &prRemoteAddress, 0) != PR_SUCCESS) {
     PR_Close(fd);
     return false;
   }
   PRNetAddr localName;
   if (PR_GetSockName(fd, &localName) != PR_SUCCESS) {
     PR_Close(fd);
     return false;
   }
   PR_Close(fd);
   char dottedDecimal[128];
   if (PR_NetAddrToString(&localName, dottedDecimal, sizeof(dottedDecimal)) != PR_SUCCESS)
     return false;
   localAddress.Assign(dottedDecimal);
   return true;
 }
 // hostName is run through a dns lookup and then a udp socket is connected
 // to the result. If that all works, the local IP address of the socket is
 // returned to the javascript caller and |*aResult| is set to true. Otherwise
 // |*aResult| is set to false.
 bool
 ProxyAutoConfig::MyIPAddressTryHost(const nsCString &hostName,
                                     unsigned int timeout,
                                     const JS::CallArgs &aArgs,
                                     bool* aResult)
 {
   *aResult = false;
   NetAddr remoteAddress;
   nsAutoCString localDottedDecimal;
   JSContext *cx = mJSRuntime->Context();
   if (PACResolve(hostName, &remoteAddress, timeout) &&
       SrcAddress(&remoteAddress, localDottedDecimal)) {
     JSString *dottedDecimalString =
       JS_NewStringCopyZ(cx, localDottedDecimal.get());
     if (!dottedDecimalString) {
       return false;
     }
     *aResult = true;
     aArgs.rval().setString(dottedDecimalString);
   }
   return true;
 }
 bool
 ProxyAutoConfig::MyIPAddress(const JS::CallArgs &aArgs)
 {
   nsAutoCString remoteDottedDecimal;
   nsAutoCString localDottedDecimal;
   JSContext *cx = mJSRuntime->Context();
   // first, lookup the local address of a socket connected
   // to the host of uri being resolved by the pac file. This is
   // v6 safe.. but is the last step like that
   bool rvalAssigned = false;
   if (!MyIPAddressTryHost(mRunningHost, kTimeout, aArgs, &rvalAssigned) ||
       rvalAssigned) {
     return rvalAssigned;
   }
   // next, look for a route to a public internet address that doesn't need DNS.
   // This is the google anycast dns address, but it doesn't matter if it
   // remains operable (as we don't contact it) as long as the address stays
   // in commonly routed IP address space.
   remoteDottedDecimal.AssignLiteral("8.8.8.8");
   if (!MyIPAddressTryHost(remoteDottedDecimal, 0, aArgs, &rvalAssigned) ||
       rvalAssigned) {
     return rvalAssigned;
   }
   // next, use the old algorithm based on the local hostname
   nsAutoCString hostName;
   nsCOMPtr<nsIDNSService> dns = do_GetService(NS_DNSSERVICE_CONTRACTID);
   if (dns && NS_SUCCEEDED(dns->GetMyHostName(hostName)) &&
       PACResolveToString(hostName, localDottedDecimal, kTimeout)) {
     JSString *dottedDecimalString =
       JS_NewStringCopyZ(cx, localDottedDecimal.get());
     if (!dottedDecimalString) {
       return false;
     }
     aArgs.rval().setString(dottedDecimalString);
     return true;
   }
   // next try a couple RFC 1918 variants.. maybe there is a
   // local route
   remoteDottedDecimal.AssignLiteral("192.168.0.1");
   if (!MyIPAddressTryHost(remoteDottedDecimal, 0, aArgs, &rvalAssigned) ||
       rvalAssigned) {
     return rvalAssigned;
   }
   // more RFC 1918
   remoteDottedDecimal.AssignLiteral("10.0.0.1");
   if (!MyIPAddressTryHost(remoteDottedDecimal, 0, aArgs, &rvalAssigned) ||
       rvalAssigned) {
     return rvalAssigned;
   }
   // who knows? let's fallback to localhost
   localDottedDecimal.AssignLiteral("127.0.0.1");
   JSString *dottedDecimalString =
     JS_NewStringCopyZ(cx, localDottedDecimal.get());
   if (!dottedDecimalString) {
     return false;
   }
   aArgs.rval().setString(dottedDecimalString);
   return true;
 }
 } // namespace mozilla
 } // namespace mozilla::net

The Tor Browser / annotate

netwerk/base/src/ProxyAutoConfig.cpp@b8a032363ba2 (annotated)

netwerk/base/src/ProxyAutoConfig.cpp