1 //
2 // Copyright (C) 2009 The Android Open Source Project
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 // http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 //
16
17 #include "update_engine/libcurl_http_fetcher.h"
18
19 #include <sys/types.h>
20 #include <unistd.h>
21
22 #include <algorithm>
23 #include <string>
24
25 #include <base/bind.h>
26 #include <base/format_macros.h>
27 #include <base/location.h>
28 #include <base/logging.h>
29 #include <base/strings/string_util.h>
30 #include <base/strings/stringprintf.h>
31
32 #ifdef __ANDROID__
33 #include <cutils/qtaguid.h>
34 #include <private/android_filesystem_config.h>
35 #endif // __ANDROID__
36
37 #include "update_engine/certificate_checker.h"
38 #include "update_engine/common/hardware_interface.h"
39 #include "update_engine/common/platform_constants.h"
40
41 using base::TimeDelta;
42 using brillo::MessageLoop;
43 using std::max;
44 using std::string;
45
46 // This is a concrete implementation of HttpFetcher that uses libcurl to do the
47 // http work.
48
49 namespace chromeos_update_engine {
50
51 namespace {
52
53 const int kNoNetworkRetrySeconds = 10;
54
55 // libcurl's CURLOPT_SOCKOPTFUNCTION callback function. Called after the socket
56 // is created but before it is connected. This callback tags the created socket
57 // so the network usage can be tracked in Android.
LibcurlSockoptCallback(void *,curl_socket_t curlfd,curlsocktype)58 int LibcurlSockoptCallback(void* /* clientp */,
59 curl_socket_t curlfd,
60 curlsocktype /* purpose */) {
61 #ifdef __ANDROID__
62 // Socket tag used by all network sockets. See qtaguid kernel module for
63 // stats.
64 const int kUpdateEngineSocketTag = 0x55417243; // "CrAU" in little-endian.
65 qtaguid_tagSocket(curlfd, kUpdateEngineSocketTag, AID_OTA_UPDATE);
66 #endif // __ANDROID__
67 return CURL_SOCKOPT_OK;
68 }
69
70 } // namespace
71
72 // static
LibcurlCloseSocketCallback(void * clientp,curl_socket_t item)73 int LibcurlHttpFetcher::LibcurlCloseSocketCallback(void* clientp,
74 curl_socket_t item) {
75 #ifdef __ANDROID__
76 qtaguid_untagSocket(item);
77 #endif // __ANDROID__
78 LibcurlHttpFetcher* fetcher = static_cast<LibcurlHttpFetcher*>(clientp);
79 // Stop watching the socket before closing it.
80 for (size_t t = 0; t < arraysize(fetcher->fd_task_maps_); ++t) {
81 const auto fd_task_pair = fetcher->fd_task_maps_[t].find(item);
82 if (fd_task_pair != fetcher->fd_task_maps_[t].end()) {
83 if (!MessageLoop::current()->CancelTask(fd_task_pair->second)) {
84 LOG(WARNING) << "Error canceling the watch task "
85 << fd_task_pair->second << " for "
86 << (t ? "writing" : "reading") << " the fd " << item;
87 }
88 fetcher->fd_task_maps_[t].erase(item);
89 }
90 }
91
92 // Documentation for this callback says to return 0 on success or 1 on error.
93 if (!IGNORE_EINTR(close(item)))
94 return 0;
95 return 1;
96 }
97
LibcurlHttpFetcher(ProxyResolver * proxy_resolver,HardwareInterface * hardware)98 LibcurlHttpFetcher::LibcurlHttpFetcher(ProxyResolver* proxy_resolver,
99 HardwareInterface* hardware)
100 : HttpFetcher(proxy_resolver), hardware_(hardware) {
101 // Dev users want a longer timeout (180 seconds) because they may
102 // be waiting on the dev server to build an image.
103 if (!hardware_->IsOfficialBuild())
104 low_speed_time_seconds_ = kDownloadDevModeLowSpeedTimeSeconds;
105 if (hardware_->IsOOBEEnabled() && !hardware_->IsOOBEComplete(nullptr))
106 max_retry_count_ = kDownloadMaxRetryCountOobeNotComplete;
107 }
108
~LibcurlHttpFetcher()109 LibcurlHttpFetcher::~LibcurlHttpFetcher() {
110 LOG_IF(ERROR, transfer_in_progress_)
111 << "Destroying the fetcher while a transfer is in progress.";
112 CancelProxyResolution();
113 CleanUp();
114 }
115
GetProxyType(const string & proxy,curl_proxytype * out_type)116 bool LibcurlHttpFetcher::GetProxyType(const string& proxy,
117 curl_proxytype* out_type) {
118 if (base::StartsWith(
119 proxy, "socks5://", base::CompareCase::INSENSITIVE_ASCII) ||
120 base::StartsWith(
121 proxy, "socks://", base::CompareCase::INSENSITIVE_ASCII)) {
122 *out_type = CURLPROXY_SOCKS5_HOSTNAME;
123 return true;
124 }
125 if (base::StartsWith(
126 proxy, "socks4://", base::CompareCase::INSENSITIVE_ASCII)) {
127 *out_type = CURLPROXY_SOCKS4A;
128 return true;
129 }
130 if (base::StartsWith(
131 proxy, "http://", base::CompareCase::INSENSITIVE_ASCII) ||
132 base::StartsWith(
133 proxy, "https://", base::CompareCase::INSENSITIVE_ASCII)) {
134 *out_type = CURLPROXY_HTTP;
135 return true;
136 }
137 if (base::StartsWith(proxy, kNoProxy, base::CompareCase::INSENSITIVE_ASCII)) {
138 // known failure case. don't log.
139 return false;
140 }
141 LOG(INFO) << "Unknown proxy type: " << proxy;
142 return false;
143 }
144
ResumeTransfer(const string & url)145 void LibcurlHttpFetcher::ResumeTransfer(const string& url) {
146 LOG(INFO) << "Starting/Resuming transfer";
147 CHECK(!transfer_in_progress_);
148 url_ = url;
149 curl_multi_handle_ = curl_multi_init();
150 CHECK(curl_multi_handle_);
151
152 curl_handle_ = curl_easy_init();
153 CHECK(curl_handle_);
154 ignore_failure_ = false;
155
156 // Tag and untag the socket for network usage stats.
157 curl_easy_setopt(
158 curl_handle_, CURLOPT_SOCKOPTFUNCTION, LibcurlSockoptCallback);
159 curl_easy_setopt(
160 curl_handle_, CURLOPT_CLOSESOCKETFUNCTION, LibcurlCloseSocketCallback);
161 curl_easy_setopt(curl_handle_, CURLOPT_CLOSESOCKETDATA, this);
162
163 CHECK(HasProxy());
164 bool is_direct = (GetCurrentProxy() == kNoProxy);
165 LOG(INFO) << "Using proxy: " << (is_direct ? "no" : "yes");
166 if (is_direct) {
167 CHECK_EQ(curl_easy_setopt(curl_handle_,
168 CURLOPT_PROXY,
169 ""), CURLE_OK);
170 } else {
171 CHECK_EQ(curl_easy_setopt(curl_handle_,
172 CURLOPT_PROXY,
173 GetCurrentProxy().c_str()), CURLE_OK);
174 // Curl seems to require us to set the protocol
175 curl_proxytype type;
176 if (GetProxyType(GetCurrentProxy(), &type)) {
177 CHECK_EQ(curl_easy_setopt(curl_handle_,
178 CURLOPT_PROXYTYPE,
179 type), CURLE_OK);
180 }
181 }
182
183 if (post_data_set_) {
184 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_POST, 1), CURLE_OK);
185 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_POSTFIELDS,
186 post_data_.data()),
187 CURLE_OK);
188 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_POSTFIELDSIZE,
189 post_data_.size()),
190 CURLE_OK);
191 }
192
193 // Setup extra HTTP headers.
194 if (curl_http_headers_) {
195 curl_slist_free_all(curl_http_headers_);
196 curl_http_headers_ = nullptr;
197 }
198 for (const auto& header : extra_headers_) {
199 // curl_slist_append() copies the string.
200 curl_http_headers_ =
201 curl_slist_append(curl_http_headers_, header.second.c_str());
202 }
203 if (post_data_set_) {
204 // Set the Content-Type HTTP header, if one was specifically set.
205 if (post_content_type_ != kHttpContentTypeUnspecified) {
206 const string content_type_attr = base::StringPrintf(
207 "Content-Type: %s", GetHttpContentTypeString(post_content_type_));
208 curl_http_headers_ =
209 curl_slist_append(curl_http_headers_, content_type_attr.c_str());
210 } else {
211 LOG(WARNING) << "no content type set, using libcurl default";
212 }
213 }
214 CHECK_EQ(
215 curl_easy_setopt(curl_handle_, CURLOPT_HTTPHEADER, curl_http_headers_),
216 CURLE_OK);
217
218 if (bytes_downloaded_ > 0 || download_length_) {
219 // Resume from where we left off.
220 resume_offset_ = bytes_downloaded_;
221 CHECK_GE(resume_offset_, 0);
222
223 // Compute end offset, if one is specified. As per HTTP specification, this
224 // is an inclusive boundary. Make sure it doesn't overflow.
225 size_t end_offset = 0;
226 if (download_length_) {
227 end_offset = static_cast<size_t>(resume_offset_) + download_length_ - 1;
228 CHECK_LE((size_t) resume_offset_, end_offset);
229 }
230
231 // Create a string representation of the desired range.
232 string range_str = base::StringPrintf(
233 "%" PRIu64 "-", static_cast<uint64_t>(resume_offset_));
234 if (end_offset)
235 range_str += std::to_string(end_offset);
236 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_RANGE, range_str.c_str()),
237 CURLE_OK);
238 }
239
240 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_WRITEDATA, this), CURLE_OK);
241 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_WRITEFUNCTION,
242 StaticLibcurlWrite), CURLE_OK);
243 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_URL, url_.c_str()),
244 CURLE_OK);
245
246 // If the connection drops under |low_speed_limit_bps_| (10
247 // bytes/sec by default) for |low_speed_time_seconds_| (90 seconds,
248 // 180 on non-official builds), reconnect.
249 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_LOW_SPEED_LIMIT,
250 low_speed_limit_bps_),
251 CURLE_OK);
252 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_LOW_SPEED_TIME,
253 low_speed_time_seconds_),
254 CURLE_OK);
255 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_CONNECTTIMEOUT,
256 connect_timeout_seconds_),
257 CURLE_OK);
258
259 // By default, libcurl doesn't follow redirections. Allow up to
260 // |kDownloadMaxRedirects| redirections.
261 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_FOLLOWLOCATION, 1), CURLE_OK);
262 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_MAXREDIRS,
263 kDownloadMaxRedirects),
264 CURLE_OK);
265
266 // Lock down the appropriate curl options for HTTP or HTTPS depending on
267 // the url.
268 if (hardware_->IsOfficialBuild()) {
269 if (base::StartsWith(
270 url_, "http://", base::CompareCase::INSENSITIVE_ASCII)) {
271 SetCurlOptionsForHttp();
272 } else if (base::StartsWith(
273 url_, "https://", base::CompareCase::INSENSITIVE_ASCII)) {
274 SetCurlOptionsForHttps();
275 #if !defined(__CHROMEOS__) && !defined(__BRILLO__)
276 } else if (base::StartsWith(
277 url_, "file://", base::CompareCase::INSENSITIVE_ASCII)) {
278 SetCurlOptionsForFile();
279 #endif
280 } else {
281 LOG(ERROR) << "Received invalid URI: " << url_;
282 // Lock down to no protocol supported for the transfer.
283 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_PROTOCOLS, 0), CURLE_OK);
284 }
285 } else {
286 LOG(INFO) << "Not setting http(s) curl options because we are "
287 << "running a dev/test image";
288 }
289
290 CHECK_EQ(curl_multi_add_handle(curl_multi_handle_, curl_handle_), CURLM_OK);
291 transfer_in_progress_ = true;
292 }
293
294 // Lock down only the protocol in case of HTTP.
SetCurlOptionsForHttp()295 void LibcurlHttpFetcher::SetCurlOptionsForHttp() {
296 LOG(INFO) << "Setting up curl options for HTTP";
297 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_PROTOCOLS, CURLPROTO_HTTP),
298 CURLE_OK);
299 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_REDIR_PROTOCOLS,
300 CURLPROTO_HTTP),
301 CURLE_OK);
302 }
303
304 // Security lock-down in official builds: makes sure that peer certificate
305 // verification is enabled, restricts the set of trusted certificates,
306 // restricts protocols to HTTPS, restricts ciphers to HIGH.
SetCurlOptionsForHttps()307 void LibcurlHttpFetcher::SetCurlOptionsForHttps() {
308 LOG(INFO) << "Setting up curl options for HTTPS";
309 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_SSL_VERIFYPEER, 1),
310 CURLE_OK);
311 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_SSL_VERIFYHOST, 2),
312 CURLE_OK);
313 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_CAPATH,
314 constants::kCACertificatesPath),
315 CURLE_OK);
316 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_PROTOCOLS, CURLPROTO_HTTPS),
317 CURLE_OK);
318 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_REDIR_PROTOCOLS,
319 CURLPROTO_HTTPS),
320 CURLE_OK);
321 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_SSL_CIPHER_LIST, "HIGH:!ADH"),
322 CURLE_OK);
323 if (server_to_check_ != ServerToCheck::kNone) {
324 CHECK_EQ(
325 curl_easy_setopt(curl_handle_, CURLOPT_SSL_CTX_DATA, &server_to_check_),
326 CURLE_OK);
327 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_SSL_CTX_FUNCTION,
328 CertificateChecker::ProcessSSLContext),
329 CURLE_OK);
330 }
331 }
332
333 // Lock down only the protocol in case of a local file.
SetCurlOptionsForFile()334 void LibcurlHttpFetcher::SetCurlOptionsForFile() {
335 LOG(INFO) << "Setting up curl options for FILE";
336 CHECK_EQ(curl_easy_setopt(curl_handle_, CURLOPT_PROTOCOLS, CURLPROTO_FILE),
337 CURLE_OK);
338 CHECK_EQ(
339 curl_easy_setopt(curl_handle_, CURLOPT_REDIR_PROTOCOLS, CURLPROTO_FILE),
340 CURLE_OK);
341 }
342
343 // Begins the transfer, which must not have already been started.
BeginTransfer(const string & url)344 void LibcurlHttpFetcher::BeginTransfer(const string& url) {
345 CHECK(!transfer_in_progress_);
346 url_ = url;
347 auto closure = base::Bind(&LibcurlHttpFetcher::ProxiesResolved,
348 base::Unretained(this));
349 ResolveProxiesForUrl(url_, closure);
350 }
351
ProxiesResolved()352 void LibcurlHttpFetcher::ProxiesResolved() {
353 transfer_size_ = -1;
354 resume_offset_ = 0;
355 retry_count_ = 0;
356 no_network_retry_count_ = 0;
357 http_response_code_ = 0;
358 terminate_requested_ = false;
359 sent_byte_ = false;
360
361 // If we are paused, we delay these two operations until Unpause is called.
362 if (transfer_paused_) {
363 restart_transfer_on_unpause_ = true;
364 return;
365 }
366 ResumeTransfer(url_);
367 CurlPerformOnce();
368 }
369
ForceTransferTermination()370 void LibcurlHttpFetcher::ForceTransferTermination() {
371 CancelProxyResolution();
372 CleanUp();
373 if (delegate_) {
374 // Note that after the callback returns this object may be destroyed.
375 delegate_->TransferTerminated(this);
376 }
377 }
378
TerminateTransfer()379 void LibcurlHttpFetcher::TerminateTransfer() {
380 if (in_write_callback_) {
381 terminate_requested_ = true;
382 } else {
383 ForceTransferTermination();
384 }
385 }
386
SetHeader(const string & header_name,const string & header_value)387 void LibcurlHttpFetcher::SetHeader(const string& header_name,
388 const string& header_value) {
389 string header_line = header_name + ": " + header_value;
390 // Avoid the space if no data on the right side of the semicolon.
391 if (header_value.empty())
392 header_line = header_name + ":";
393 TEST_AND_RETURN(header_line.find('\n') == string::npos);
394 TEST_AND_RETURN(header_name.find(':') == string::npos);
395 extra_headers_[base::ToLowerASCII(header_name)] = header_line;
396 }
397
CurlPerformOnce()398 void LibcurlHttpFetcher::CurlPerformOnce() {
399 CHECK(transfer_in_progress_);
400 int running_handles = 0;
401 CURLMcode retcode = CURLM_CALL_MULTI_PERFORM;
402
403 // libcurl may request that we immediately call curl_multi_perform after it
404 // returns, so we do. libcurl promises that curl_multi_perform will not block.
405 while (CURLM_CALL_MULTI_PERFORM == retcode) {
406 retcode = curl_multi_perform(curl_multi_handle_, &running_handles);
407 if (terminate_requested_) {
408 ForceTransferTermination();
409 return;
410 }
411 }
412
413 // If the transfer completes while paused, we should ignore the failure once
414 // the fetcher is unpaused.
415 if (running_handles == 0 && transfer_paused_ && !ignore_failure_) {
416 LOG(INFO) << "Connection closed while paused, ignoring failure.";
417 ignore_failure_ = true;
418 }
419
420 if (running_handles != 0 || transfer_paused_) {
421 // There's either more work to do or we are paused, so we just keep the
422 // file descriptors to watch up to date and exit, until we are done with the
423 // work and we are not paused.
424 SetupMessageLoopSources();
425 return;
426 }
427
428 // At this point, the transfer was completed in some way (error, connection
429 // closed or download finished).
430
431 GetHttpResponseCode();
432 if (http_response_code_) {
433 LOG(INFO) << "HTTP response code: " << http_response_code_;
434 no_network_retry_count_ = 0;
435 } else {
436 LOG(ERROR) << "Unable to get http response code.";
437 }
438
439 // we're done!
440 CleanUp();
441
442 // TODO(petkov): This temporary code tries to deal with the case where the
443 // update engine performs an update check while the network is not ready
444 // (e.g., right after resume). Longer term, we should check if the network
445 // is online/offline and return an appropriate error code.
446 if (!sent_byte_ &&
447 http_response_code_ == 0 &&
448 no_network_retry_count_ < no_network_max_retries_) {
449 no_network_retry_count_++;
450 retry_task_id_ = MessageLoop::current()->PostDelayedTask(
451 FROM_HERE,
452 base::Bind(&LibcurlHttpFetcher::RetryTimeoutCallback,
453 base::Unretained(this)),
454 TimeDelta::FromSeconds(kNoNetworkRetrySeconds));
455 LOG(INFO) << "No HTTP response, retry " << no_network_retry_count_;
456 } else if ((!sent_byte_ && !IsHttpResponseSuccess()) ||
457 IsHttpResponseError()) {
458 // The transfer completed w/ error and we didn't get any bytes.
459 // If we have another proxy to try, try that.
460 //
461 // TODO(garnold) in fact there are two separate cases here: one case is an
462 // other-than-success return code (including no return code) and no
463 // received bytes, which is necessary due to the way callbacks are
464 // currently processing error conditions; the second is an explicit HTTP
465 // error code, where some data may have been received (as in the case of a
466 // semi-successful multi-chunk fetch). This is a confusing behavior and
467 // should be unified into a complete, coherent interface.
468 LOG(INFO) << "Transfer resulted in an error (" << http_response_code_
469 << "), " << bytes_downloaded_ << " bytes downloaded";
470
471 PopProxy(); // Delete the proxy we just gave up on.
472
473 if (HasProxy()) {
474 // We have another proxy. Retry immediately.
475 LOG(INFO) << "Retrying with next proxy setting";
476 retry_task_id_ = MessageLoop::current()->PostTask(
477 FROM_HERE,
478 base::Bind(&LibcurlHttpFetcher::RetryTimeoutCallback,
479 base::Unretained(this)));
480 } else {
481 // Out of proxies. Give up.
482 LOG(INFO) << "No further proxies, indicating transfer complete";
483 if (delegate_)
484 delegate_->TransferComplete(this, false); // signal fail
485 return;
486 }
487 } else if ((transfer_size_ >= 0) && (bytes_downloaded_ < transfer_size_)) {
488 if (!ignore_failure_)
489 retry_count_++;
490 LOG(INFO) << "Transfer interrupted after downloading "
491 << bytes_downloaded_ << " of " << transfer_size_ << " bytes. "
492 << transfer_size_ - bytes_downloaded_ << " bytes remaining "
493 << "after " << retry_count_ << " attempt(s)";
494
495 if (retry_count_ > max_retry_count_) {
496 LOG(INFO) << "Reached max attempts (" << retry_count_ << ")";
497 if (delegate_)
498 delegate_->TransferComplete(this, false); // signal fail
499 return;
500 }
501 // Need to restart transfer
502 LOG(INFO) << "Restarting transfer to download the remaining bytes";
503 retry_task_id_ = MessageLoop::current()->PostDelayedTask(
504 FROM_HERE,
505 base::Bind(&LibcurlHttpFetcher::RetryTimeoutCallback,
506 base::Unretained(this)),
507 TimeDelta::FromSeconds(retry_seconds_));
508 } else {
509 LOG(INFO) << "Transfer completed (" << http_response_code_
510 << "), " << bytes_downloaded_ << " bytes downloaded";
511 if (delegate_) {
512 bool success = IsHttpResponseSuccess();
513 delegate_->TransferComplete(this, success);
514 }
515 return;
516 }
517 // If we reach this point is because TransferComplete() was not called in any
518 // of the previous branches. The delegate is allowed to destroy the object
519 // once TransferComplete is called so this would be illegal.
520 ignore_failure_ = false;
521 }
522
LibcurlWrite(void * ptr,size_t size,size_t nmemb)523 size_t LibcurlHttpFetcher::LibcurlWrite(void *ptr, size_t size, size_t nmemb) {
524 // Update HTTP response first.
525 GetHttpResponseCode();
526 const size_t payload_size = size * nmemb;
527
528 // Do nothing if no payload or HTTP response is an error.
529 if (payload_size == 0 || !IsHttpResponseSuccess()) {
530 LOG(INFO) << "HTTP response unsuccessful (" << http_response_code_
531 << ") or no payload (" << payload_size << "), nothing to do";
532 return 0;
533 }
534
535 sent_byte_ = true;
536 {
537 double transfer_size_double;
538 CHECK_EQ(curl_easy_getinfo(curl_handle_,
539 CURLINFO_CONTENT_LENGTH_DOWNLOAD,
540 &transfer_size_double), CURLE_OK);
541 off_t new_transfer_size = static_cast<off_t>(transfer_size_double);
542 if (new_transfer_size > 0) {
543 transfer_size_ = resume_offset_ + new_transfer_size;
544 }
545 }
546 bytes_downloaded_ += payload_size;
547 in_write_callback_ = true;
548 if (delegate_)
549 delegate_->ReceivedBytes(this, ptr, payload_size);
550 in_write_callback_ = false;
551 return payload_size;
552 }
553
Pause()554 void LibcurlHttpFetcher::Pause() {
555 if (transfer_paused_) {
556 LOG(ERROR) << "Fetcher already paused.";
557 return;
558 }
559 transfer_paused_ = true;
560 if (!transfer_in_progress_) {
561 // If pause before we started a connection, we don't need to notify curl
562 // about that, we will simply not start the connection later.
563 return;
564 }
565 CHECK(curl_handle_);
566 CHECK_EQ(curl_easy_pause(curl_handle_, CURLPAUSE_ALL), CURLE_OK);
567 }
568
Unpause()569 void LibcurlHttpFetcher::Unpause() {
570 if (!transfer_paused_) {
571 LOG(ERROR) << "Resume attempted when fetcher not paused.";
572 return;
573 }
574 transfer_paused_ = false;
575 if (restart_transfer_on_unpause_) {
576 restart_transfer_on_unpause_ = false;
577 ResumeTransfer(url_);
578 CurlPerformOnce();
579 return;
580 }
581 if (!transfer_in_progress_) {
582 // If resumed before starting the connection, there's no need to notify
583 // anybody. We will simply start the connection once it is time.
584 return;
585 }
586 CHECK(curl_handle_);
587 CHECK_EQ(curl_easy_pause(curl_handle_, CURLPAUSE_CONT), CURLE_OK);
588 // Since the transfer is in progress, we need to dispatch a CurlPerformOnce()
589 // now to let the connection continue, otherwise it would be called by the
590 // TimeoutCallback but with a delay.
591 CurlPerformOnce();
592 }
593
594 // This method sets up callbacks with the MessageLoop.
SetupMessageLoopSources()595 void LibcurlHttpFetcher::SetupMessageLoopSources() {
596 fd_set fd_read;
597 fd_set fd_write;
598 fd_set fd_exc;
599
600 FD_ZERO(&fd_read);
601 FD_ZERO(&fd_write);
602 FD_ZERO(&fd_exc);
603
604 int fd_max = 0;
605
606 // Ask libcurl for the set of file descriptors we should track on its
607 // behalf.
608 CHECK_EQ(curl_multi_fdset(curl_multi_handle_, &fd_read, &fd_write,
609 &fd_exc, &fd_max), CURLM_OK);
610
611 // We should iterate through all file descriptors up to libcurl's fd_max or
612 // the highest one we're tracking, whichever is larger.
613 for (size_t t = 0; t < arraysize(fd_task_maps_); ++t) {
614 if (!fd_task_maps_[t].empty())
615 fd_max = max(fd_max, fd_task_maps_[t].rbegin()->first);
616 }
617
618 // For each fd, if we're not tracking it, track it. If we are tracking it, but
619 // libcurl doesn't care about it anymore, stop tracking it. After this loop,
620 // there should be exactly as many tasks scheduled in fd_task_maps_[0|1] as
621 // there are read/write fds that we're tracking.
622 for (int fd = 0; fd <= fd_max; ++fd) {
623 // Note that fd_exc is unused in the current version of libcurl so is_exc
624 // should always be false.
625 bool is_exc = FD_ISSET(fd, &fd_exc) != 0;
626 bool must_track[2] = {
627 is_exc || (FD_ISSET(fd, &fd_read) != 0), // track 0 -- read
628 is_exc || (FD_ISSET(fd, &fd_write) != 0) // track 1 -- write
629 };
630 MessageLoop::WatchMode watch_modes[2] = {
631 MessageLoop::WatchMode::kWatchRead,
632 MessageLoop::WatchMode::kWatchWrite,
633 };
634
635 for (size_t t = 0; t < arraysize(fd_task_maps_); ++t) {
636 auto fd_task_it = fd_task_maps_[t].find(fd);
637 bool tracked = fd_task_it != fd_task_maps_[t].end();
638
639 if (!must_track[t]) {
640 // If we have an outstanding io_channel, remove it.
641 if (tracked) {
642 MessageLoop::current()->CancelTask(fd_task_it->second);
643 fd_task_maps_[t].erase(fd_task_it);
644 }
645 continue;
646 }
647
648 // If we are already tracking this fd, continue -- nothing to do.
649 if (tracked)
650 continue;
651
652 // Track a new fd.
653 fd_task_maps_[t][fd] = MessageLoop::current()->WatchFileDescriptor(
654 FROM_HERE,
655 fd,
656 watch_modes[t],
657 true, // persistent
658 base::Bind(&LibcurlHttpFetcher::CurlPerformOnce,
659 base::Unretained(this)));
660
661 static int io_counter = 0;
662 io_counter++;
663 if (io_counter % 50 == 0) {
664 LOG(INFO) << "io_counter = " << io_counter;
665 }
666 }
667 }
668
669 // Set up a timeout callback for libcurl.
670 if (timeout_id_ == MessageLoop::kTaskIdNull) {
671 VLOG(1) << "Setting up timeout source: " << idle_seconds_ << " seconds.";
672 timeout_id_ = MessageLoop::current()->PostDelayedTask(
673 FROM_HERE,
674 base::Bind(&LibcurlHttpFetcher::TimeoutCallback,
675 base::Unretained(this)),
676 TimeDelta::FromSeconds(idle_seconds_));
677 }
678 }
679
RetryTimeoutCallback()680 void LibcurlHttpFetcher::RetryTimeoutCallback() {
681 retry_task_id_ = MessageLoop::kTaskIdNull;
682 if (transfer_paused_) {
683 restart_transfer_on_unpause_ = true;
684 return;
685 }
686 ResumeTransfer(url_);
687 CurlPerformOnce();
688 }
689
TimeoutCallback()690 void LibcurlHttpFetcher::TimeoutCallback() {
691 // We always re-schedule the callback, even if we don't want to be called
692 // anymore. We will remove the event source separately if we don't want to
693 // be called back.
694 timeout_id_ = MessageLoop::current()->PostDelayedTask(
695 FROM_HERE,
696 base::Bind(&LibcurlHttpFetcher::TimeoutCallback, base::Unretained(this)),
697 TimeDelta::FromSeconds(idle_seconds_));
698
699 // CurlPerformOnce() may call CleanUp(), so we need to schedule our callback
700 // first, since it could be canceled by this call.
701 if (transfer_in_progress_)
702 CurlPerformOnce();
703 }
704
CleanUp()705 void LibcurlHttpFetcher::CleanUp() {
706 MessageLoop::current()->CancelTask(retry_task_id_);
707 retry_task_id_ = MessageLoop::kTaskIdNull;
708
709 MessageLoop::current()->CancelTask(timeout_id_);
710 timeout_id_ = MessageLoop::kTaskIdNull;
711
712 for (size_t t = 0; t < arraysize(fd_task_maps_); ++t) {
713 for (const auto& fd_taks_pair : fd_task_maps_[t]) {
714 if (!MessageLoop::current()->CancelTask(fd_taks_pair.second)) {
715 LOG(WARNING) << "Error canceling the watch task "
716 << fd_taks_pair.second << " for "
717 << (t ? "writing" : "reading") << " the fd "
718 << fd_taks_pair.first;
719 }
720 }
721 fd_task_maps_[t].clear();
722 }
723
724 if (curl_http_headers_) {
725 curl_slist_free_all(curl_http_headers_);
726 curl_http_headers_ = nullptr;
727 }
728 if (curl_handle_) {
729 if (curl_multi_handle_) {
730 CHECK_EQ(curl_multi_remove_handle(curl_multi_handle_, curl_handle_),
731 CURLM_OK);
732 }
733 curl_easy_cleanup(curl_handle_);
734 curl_handle_ = nullptr;
735 }
736 if (curl_multi_handle_) {
737 CHECK_EQ(curl_multi_cleanup(curl_multi_handle_), CURLM_OK);
738 curl_multi_handle_ = nullptr;
739 }
740 transfer_in_progress_ = false;
741 transfer_paused_ = false;
742 restart_transfer_on_unpause_ = false;
743 }
744
GetHttpResponseCode()745 void LibcurlHttpFetcher::GetHttpResponseCode() {
746 long http_response_code = 0; // NOLINT(runtime/int) - curl needs long.
747 if (base::StartsWith(url_, "file://", base::CompareCase::INSENSITIVE_ASCII)) {
748 // Fake out a valid response code for file:// URLs.
749 http_response_code_ = 299;
750 } else if (curl_easy_getinfo(curl_handle_,
751 CURLINFO_RESPONSE_CODE,
752 &http_response_code) == CURLE_OK) {
753 http_response_code_ = static_cast<int>(http_response_code);
754 }
755 }
756
757 } // namespace chromeos_update_engine
758