net/dns/mock_host_resolver.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "net/dns/mock_host_resolver.h"
   6
   7 #include <string>
   8 #include <vector>
   9
  10 #include "base/bind.h"
  11 #include "base/location.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/single_thread_task_runner.h"
  14 #include "base/stl_util.h"
  15 #include "base/strings/pattern.h"
  16 #include "base/strings/string_split.h"
  17 #include "base/strings/string_util.h"
  18 #include "base/thread_task_runner_handle.h"
  19 #include "base/threading/platform_thread.h"
  20 #include "net/base/ip_endpoint.h"
  21 #include "net/base/net_errors.h"
  22 #include "net/base/net_util.h"
  23 #include "net/base/test_completion_callback.h"
  24 #include "net/dns/host_cache.h"
  25
  26 #if defined(OS_WIN)
  27 #include "net/base/winsock_init.h"
  28 #endif
  29
  30 namespace net {
  31
  32 namespace {
  33
  34 // Cache size for the MockCachingHostResolver.
  35 const unsigned kMaxCacheEntries = 100;
  36 // TTL for the successful resolutions. Failures are not cached.
  37 const unsigned kCacheEntryTTLSeconds = 60;
  38
  39 }  // namespace
  40
  41 int ParseAddressList(const std::string& host_list,
  42                      const std::string& canonical_name,
  43                      AddressList* addrlist) {
  44   *addrlist = AddressList();
  45   addrlist->set_canonical_name(canonical_name);
  46   for (const base::StringPiece& address : base::SplitStringPiece(
  47            host_list, ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL)) {
  48     IPAddressNumber ip_number;
  49     if (!ParseIPLiteralToNumber(address, &ip_number)) {
  50       LOG(WARNING) << "Not a supported IP literal: " << address.as_string();
  51       return ERR_UNEXPECTED;
  52     }
  53     addrlist->push_back(IPEndPoint(ip_number, 0));
  54   }
  55   return OK;
  56 }
  57
  58 struct MockHostResolverBase::Request {
  59   Request(const RequestInfo& req_info,
  60           AddressList* addr,
  61           const CompletionCallback& cb)
  62       : info(req_info), addresses(addr), callback(cb) {}
  63   RequestInfo info;
  64   AddressList* addresses;
  65   CompletionCallback callback;
  66 };
  67
  68 MockHostResolverBase::~MockHostResolverBase() {
  69   STLDeleteValues(&requests_);
  70 }
  71
  72 int MockHostResolverBase::Resolve(const RequestInfo& info,
  73                                   RequestPriority priority,
  74                                   AddressList* addresses,
  75                                   const CompletionCallback& callback,
  76                                   RequestHandle* handle,
  77                                   const BoundNetLog& net_log) {
  78   DCHECK(CalledOnValidThread());
  79   last_request_priority_ = priority;
  80   num_resolve_++;
  81   size_t id = next_request_id_++;
  82   int rv = ResolveFromIPLiteralOrCache(info, addresses);
  83   if (rv != ERR_DNS_CACHE_MISS) {
  84     return rv;
  85   }
  86   if (synchronous_mode_) {
  87     return ResolveProc(id, info, addresses);
  88   }
  89   // Store the request for asynchronous resolution
  90   Request* req = new Request(info, addresses, callback);
  91   requests_[id] = req;
  92   if (handle)
  93     *handle = reinterpret_cast<RequestHandle>(id);
  94
  95   if (!ondemand_mode_) {
  96     base::ThreadTaskRunnerHandle::Get()->PostTask(
  97         FROM_HERE,
  98         base::Bind(&MockHostResolverBase::ResolveNow, AsWeakPtr(), id));
  99   }
 100
 101   return ERR_IO_PENDING;
 102 }
 103
 104 int MockHostResolverBase::ResolveFromCache(const RequestInfo& info,
 105                                            AddressList* addresses,
 106                                            const BoundNetLog& net_log) {
 107   num_resolve_from_cache_++;
 108   DCHECK(CalledOnValidThread());
 109   next_request_id_++;
 110   int rv = ResolveFromIPLiteralOrCache(info, addresses);
 111   return rv;
 112 }
 113
 114 void MockHostResolverBase::CancelRequest(RequestHandle handle) {
 115   DCHECK(CalledOnValidThread());
 116   size_t id = reinterpret_cast<size_t>(handle);
 117   RequestMap::iterator it = requests_.find(id);
 118   if (it != requests_.end()) {
 119     scoped_ptr<Request> req(it->second);
 120     requests_.erase(it);
 121   } else {
 122     NOTREACHED() << "CancelRequest must NOT be called after request is "
 123         "complete or canceled.";
 124   }
 125 }
 126
 127 HostCache* MockHostResolverBase::GetHostCache() {
 128   return cache_.get();
 129 }
 130
 131 void MockHostResolverBase::ResolveAllPending() {
 132   DCHECK(CalledOnValidThread());
 133   DCHECK(ondemand_mode_);
 134   for (RequestMap::iterator i = requests_.begin(); i != requests_.end(); ++i) {
 135     base::ThreadTaskRunnerHandle::Get()->PostTask(
 136         FROM_HERE,
 137         base::Bind(&MockHostResolverBase::ResolveNow, AsWeakPtr(), i->first));
 138   }
 139 }
 140
 141 // start id from 1 to distinguish from NULL RequestHandle
 142 MockHostResolverBase::MockHostResolverBase(bool use_caching)
 143     : last_request_priority_(DEFAULT_PRIORITY),
 144       synchronous_mode_(false),
 145       ondemand_mode_(false),
 146       next_request_id_(1),
 147       num_resolve_(0),
 148       num_resolve_from_cache_(0) {
 149   rules_ = CreateCatchAllHostResolverProc();
 150
 151   if (use_caching) {
 152     cache_.reset(new HostCache(kMaxCacheEntries));
 153   }
 154 }
 155
 156 int MockHostResolverBase::ResolveFromIPLiteralOrCache(const RequestInfo& info,
 157                                                       AddressList* addresses) {
 158   IPAddressNumber ip;
 159   if (ParseIPLiteralToNumber(info.hostname(), &ip)) {
 160     // This matches the behavior HostResolverImpl.
 161     if (info.address_family() != ADDRESS_FAMILY_UNSPECIFIED &&
 162         info.address_family() != GetAddressFamily(ip)) {
 163       return ERR_NAME_NOT_RESOLVED;
 164     }
 165
 166     *addresses = AddressList::CreateFromIPAddress(ip, info.port());
 167     if (info.host_resolver_flags() & HOST_RESOLVER_CANONNAME)
 168       addresses->SetDefaultCanonicalName();
 169     return OK;
 170   }
 171   int rv = ERR_DNS_CACHE_MISS;
 172   if (cache_.get() && info.allow_cached_response()) {
 173     HostCache::Key key(info.hostname(),
 174                        info.address_family(),
 175                        info.host_resolver_flags());
 176     const HostCache::Entry* entry = cache_->Lookup(key, base::TimeTicks::Now());
 177     if (entry) {
 178       rv = entry->error;
 179       if (rv == OK)
 180         *addresses = AddressList::CopyWithPort(entry->addrlist, info.port());
 181     }
 182   }
 183   return rv;
 184 }
 185
 186 int MockHostResolverBase::ResolveProc(size_t id,
 187                                       const RequestInfo& info,
 188                                       AddressList* addresses) {
 189   AddressList addr;
 190   int rv = rules_->Resolve(info.hostname(),
 191                            info.address_family(),
 192                            info.host_resolver_flags(),
 193                            &addr,
 194                            NULL);
 195   if (cache_.get()) {
 196     HostCache::Key key(info.hostname(),
 197                        info.address_family(),
 198                        info.host_resolver_flags());
 199     // Storing a failure with TTL 0 so that it overwrites previous value.
 200     base::TimeDelta ttl;
 201     if (rv == OK)
 202       ttl = base::TimeDelta::FromSeconds(kCacheEntryTTLSeconds);
 203     cache_->Set(key, HostCache::Entry(rv, addr), base::TimeTicks::Now(), ttl);
 204   }
 205   if (rv == OK)
 206     *addresses = AddressList::CopyWithPort(addr, info.port());
 207   return rv;
 208 }
 209
 210 void MockHostResolverBase::ResolveNow(size_t id) {
 211   RequestMap::iterator it = requests_.find(id);
 212   if (it == requests_.end())
 213     return;  // was canceled
 214
 215   scoped_ptr<Request> req(it->second);
 216   requests_.erase(it);
 217   int rv = ResolveProc(id, req->info, req->addresses);
 218   if (!req->callback.is_null())
 219     req->callback.Run(rv);
 220 }
 221
 222 //-----------------------------------------------------------------------------
 223
 224 struct RuleBasedHostResolverProc::Rule {
 225   enum ResolverType {
 226     kResolverTypeFail,
 227     kResolverTypeSystem,
 228     kResolverTypeIPLiteral,
 229   };
 230
 231   ResolverType resolver_type;
 232   std::string host_pattern;
 233   AddressFamily address_family;
 234   HostResolverFlags host_resolver_flags;
 235   std::string replacement;
 236   std::string canonical_name;
 237   int latency_ms;  // In milliseconds.
 238
 239   Rule(ResolverType resolver_type,
 240        const std::string& host_pattern,
 241        AddressFamily address_family,
 242        HostResolverFlags host_resolver_flags,
 243        const std::string& replacement,
 244        const std::string& canonical_name,
 245        int latency_ms)
 246       : resolver_type(resolver_type),
 247         host_pattern(host_pattern),
 248         address_family(address_family),
 249         host_resolver_flags(host_resolver_flags),
 250         replacement(replacement),
 251         canonical_name(canonical_name),
 252         latency_ms(latency_ms) {}
 253 };
 254
 255 RuleBasedHostResolverProc::RuleBasedHostResolverProc(HostResolverProc* previous)
 256     : HostResolverProc(previous) {
 257 }
 258
 259 void RuleBasedHostResolverProc::AddRule(const std::string& host_pattern,
 260                                         const std::string& replacement) {
 261   AddRuleForAddressFamily(host_pattern, ADDRESS_FAMILY_UNSPECIFIED,
 262                           replacement);
 263 }
 264
 265 void RuleBasedHostResolverProc::AddRuleForAddressFamily(
 266     const std::string& host_pattern,
 267     AddressFamily address_family,
 268     const std::string& replacement) {
 269   DCHECK(!replacement.empty());
 270   HostResolverFlags flags = HOST_RESOLVER_LOOPBACK_ONLY |
 271       HOST_RESOLVER_DEFAULT_FAMILY_SET_DUE_TO_NO_IPV6;
 272   Rule rule(Rule::kResolverTypeSystem,
 273             host_pattern,
 274             address_family,
 275             flags,
 276             replacement,
 277             std::string(),
 278             0);
 279   rules_.push_back(rule);
 280 }
 281
 282 void RuleBasedHostResolverProc::AddIPLiteralRule(
 283     const std::string& host_pattern,
 284     const std::string& ip_literal,
 285     const std::string& canonical_name) {
 286   // Literals are always resolved to themselves by HostResolverImpl,
 287   // consequently we do not support remapping them.
 288   IPAddressNumber ip_number;
 289   DCHECK(!ParseIPLiteralToNumber(host_pattern, &ip_number));
 290   HostResolverFlags flags = HOST_RESOLVER_LOOPBACK_ONLY |
 291       HOST_RESOLVER_DEFAULT_FAMILY_SET_DUE_TO_NO_IPV6;
 292   if (!canonical_name.empty())
 293     flags |= HOST_RESOLVER_CANONNAME;
 294   Rule rule(Rule::kResolverTypeIPLiteral, host_pattern,
 295             ADDRESS_FAMILY_UNSPECIFIED, flags, ip_literal, canonical_name,
 296             0);
 297   rules_.push_back(rule);
 298 }
 299
 300 void RuleBasedHostResolverProc::AddRuleWithLatency(
 301     const std::string& host_pattern,
 302     const std::string& replacement,
 303     int latency_ms) {
 304   DCHECK(!replacement.empty());
 305   HostResolverFlags flags = HOST_RESOLVER_LOOPBACK_ONLY |
 306       HOST_RESOLVER_DEFAULT_FAMILY_SET_DUE_TO_NO_IPV6;
 307   Rule rule(Rule::kResolverTypeSystem,
 308             host_pattern,
 309             ADDRESS_FAMILY_UNSPECIFIED,
 310             flags,
 311             replacement,
 312             std::string(),
 313             latency_ms);
 314   rules_.push_back(rule);
 315 }
 316
 317 void RuleBasedHostResolverProc::AllowDirectLookup(
 318     const std::string& host_pattern) {
 319   HostResolverFlags flags = HOST_RESOLVER_LOOPBACK_ONLY |
 320       HOST_RESOLVER_DEFAULT_FAMILY_SET_DUE_TO_NO_IPV6;
 321   Rule rule(Rule::kResolverTypeSystem,
 322             host_pattern,
 323             ADDRESS_FAMILY_UNSPECIFIED,
 324             flags,
 325             std::string(),
 326             std::string(),
 327             0);
 328   rules_.push_back(rule);
 329 }
 330
 331 void RuleBasedHostResolverProc::AddSimulatedFailure(
 332     const std::string& host_pattern) {
 333   HostResolverFlags flags = HOST_RESOLVER_LOOPBACK_ONLY |
 334       HOST_RESOLVER_DEFAULT_FAMILY_SET_DUE_TO_NO_IPV6;
 335   Rule rule(Rule::kResolverTypeFail,
 336             host_pattern,
 337             ADDRESS_FAMILY_UNSPECIFIED,
 338             flags,
 339             std::string(),
 340             std::string(),
 341             0);
 342   rules_.push_back(rule);
 343 }
 344
 345 void RuleBasedHostResolverProc::ClearRules() {
 346   rules_.clear();
 347 }
 348
 349 int RuleBasedHostResolverProc::Resolve(const std::string& host,
 350                                        AddressFamily address_family,
 351                                        HostResolverFlags host_resolver_flags,
 352                                        AddressList* addrlist,
 353                                        int* os_error) {
 354   RuleList::iterator r;
 355   for (r = rules_.begin(); r != rules_.end(); ++r) {
 356     bool matches_address_family =
 357         r->address_family == ADDRESS_FAMILY_UNSPECIFIED ||
 358         r->address_family == address_family;
 359     // Ignore HOST_RESOLVER_SYSTEM_ONLY, since it should have no impact on
 360     // whether a rule matches.
 361     HostResolverFlags flags = host_resolver_flags & ~HOST_RESOLVER_SYSTEM_ONLY;
 362     // Flags match if all of the bitflags in host_resolver_flags are enabled
 363     // in the rule's host_resolver_flags. However, the rule may have additional
 364     // flags specified, in which case the flags should still be considered a
 365     // match.
 366     bool matches_flags = (r->host_resolver_flags & flags) == flags;
 367     if (matches_flags && matches_address_family &&
 368         base::MatchPattern(host, r->host_pattern)) {
 369       if (r->latency_ms != 0) {
 370         base::PlatformThread::Sleep(
 371             base::TimeDelta::FromMilliseconds(r->latency_ms));
 372       }
 373
 374       // Remap to a new host.
 375       const std::string& effective_host =
 376           r->replacement.empty() ? host : r->replacement;
 377
 378       // Apply the resolving function to the remapped hostname.
 379       switch (r->resolver_type) {
 380         case Rule::kResolverTypeFail:
 381           return ERR_NAME_NOT_RESOLVED;
 382         case Rule::kResolverTypeSystem:
 383 #if defined(OS_WIN)
 384           EnsureWinsockInit();
 385 #endif
 386           return SystemHostResolverCall(effective_host,
 387                                         address_family,
 388                                         host_resolver_flags,
 389                                         addrlist, os_error);
 390         case Rule::kResolverTypeIPLiteral:
 391           return ParseAddressList(effective_host,
 392                                   r->canonical_name,
 393                                   addrlist);
 394         default:
 395           NOTREACHED();
 396           return ERR_UNEXPECTED;
 397       }
 398     }
 399   }
 400   return ResolveUsingPrevious(host, address_family,
 401                               host_resolver_flags, addrlist, os_error);
 402 }
 403
 404 RuleBasedHostResolverProc::~RuleBasedHostResolverProc() {
 405 }
 406
 407 RuleBasedHostResolverProc* CreateCatchAllHostResolverProc() {
 408   RuleBasedHostResolverProc* catchall = new RuleBasedHostResolverProc(NULL);
 409   catchall->AddIPLiteralRule("*", "127.0.0.1", "localhost");
 410
 411   // Next add a rules-based layer the use controls.
 412   return new RuleBasedHostResolverProc(catchall);
 413 }
 414
 415 //-----------------------------------------------------------------------------
 416
 417 int HangingHostResolver::Resolve(const RequestInfo& info,
 418                                  RequestPriority priority,
 419                                  AddressList* addresses,
 420                                  const CompletionCallback& callback,
 421                                  RequestHandle* out_req,
 422                                  const BoundNetLog& net_log) {
 423   return ERR_IO_PENDING;
 424 }
 425
 426 int HangingHostResolver::ResolveFromCache(const RequestInfo& info,
 427                                           AddressList* addresses,
 428                                           const BoundNetLog& net_log) {
 429   return ERR_DNS_CACHE_MISS;
 430 }
 431
 432 //-----------------------------------------------------------------------------
 433
 434 ScopedDefaultHostResolverProc::ScopedDefaultHostResolverProc() {}
 435
 436 ScopedDefaultHostResolverProc::ScopedDefaultHostResolverProc(
 437     HostResolverProc* proc) {
 438   Init(proc);
 439 }
 440
 441 ScopedDefaultHostResolverProc::~ScopedDefaultHostResolverProc() {
 442   HostResolverProc* old_proc =
 443       HostResolverProc::SetDefault(previous_proc_.get());
 444   // The lifetimes of multiple instances must be nested.
 445   CHECK_EQ(old_proc, current_proc_.get());
 446 }
 447
 448 void ScopedDefaultHostResolverProc::Init(HostResolverProc* proc) {
 449   current_proc_ = proc;
 450   previous_proc_ = HostResolverProc::SetDefault(current_proc_.get());
 451   current_proc_->SetLastProc(previous_proc_.get());
 452 }
 453
 454 }  // namespace net