Files
MapLibreParticleLab/platform/default/http_request_curl.cpp
2015-04-13 18:28:18 +02:00

764 lines
24 KiB
C++

#include <mbgl/storage/http_request.hpp>
#include <mbgl/storage/http_context.hpp>
#include <mbgl/storage/response.hpp>
#include <mbgl/util/chrono.hpp>
#include <mbgl/platform/log.hpp>
#include <mbgl/util/time.hpp>
#include <curl/curl.h>
#ifdef __ANDROID__
#include <mbgl/android/jni.hpp>
#include <zip.h>
#include <openssl/ssl.h>
#endif
#include <queue>
#include <map>
#include <cassert>
#include <cstring>
void handleError(CURLMcode code) {
if (code != CURLM_OK) {
throw std::runtime_error(std::string("CURL multi error: ") + curl_multi_strerror(code));
}
}
void handleError(CURLcode code) {
if (code != CURLE_OK) {
throw std::runtime_error(std::string("CURL easy error: ") + curl_easy_strerror(code));
}
}
namespace mbgl {
enum class ResponseStatus : int8_t {
// This error probably won't be resolved by retrying anytime soon. We are giving up.
PermanentError,
// This error might be resolved by waiting some time (e.g. server issues).
// We are going to do an exponential back-off and will try again in a few seconds.
TemporaryError,
// This error might be resolved once the network reachability status changes.
// We are going to watch the network status for changes and will retry as soon as the
// operating system notifies us of a network status change.
ConnectionError,
// The request returned data successfully. We retrieved and decoded the data successfully.
Successful,
// The request confirmed that the data wasn't changed. We already have the data.
NotModified,
};
class HTTPRequestImpl;
class HTTPCURLContext : public HTTPContext<HTTPCURLContext> {
public:
HTTPCURLContext(uv_loop_t *loop);
~HTTPCURLContext();
static int handleSocket(CURL *handle, curl_socket_t s, int action, void *userp, void *socketp);
static void perform(uv_poll_t *req, int status, int events);
static int startTimeout(CURLM *multi, long timeout_ms, void *userp);
#if UV_VERSION_MAJOR == 0 && UV_VERSION_MINOR <= 10
static void onTimeout(uv_timer_t *req, int status);
#else
static void onTimeout(uv_timer_t *req);
#endif
CURL *getHandle();
void returnHandle(CURL *handle);
void checkMultiInfo();
public:
// Used as the CURL timer function to periodically check for socket updates.
uv_timer_t *timeout = nullptr;
// CURL multi handle that we use to request multiple URLs at the same time, without having to
// block and spawn threads.
CURLM *multi = nullptr;
// CURL share handles are used for sharing session state (e.g.)
CURLSH *share = nullptr;
// A queue that we use for storing resuable CURL easy handles to avoid creating and destroying
// them all the time.
std::queue<CURL *> handles;
};
class HTTPRequestImpl {
MBGL_STORE_THREAD(tid)
public:
HTTPRequestImpl(HTTPRequest *request, uv_loop_t *loop, std::shared_ptr<const Response> response);
~HTTPRequestImpl();
void handleResult(CURLcode code);
void abandon();
void retryImmediately();
private:
static size_t headerCallback(char *const buffer, const size_t size, const size_t nmemb, void *userp);
static size_t writeCallback(void *const contents, const size_t size, const size_t nmemb, void *userp);
void retry(uint64_t timeout);
#if UV_VERSION_MAJOR == 0 && UV_VERSION_MINOR <= 10
static void restart(uv_timer_t *timer, int);
#else
static void restart(uv_timer_t *timer);
#endif
void finish(ResponseStatus status);
void start();
private:
HTTPCURLContext *context = nullptr;
HTTPRequest *request = nullptr;
// Will store the current response.
std::unique_ptr<Response> response;
// In case of revalidation requests, this will store the old response.
const std::shared_ptr<const Response> existingResponse;
CURL *handle = nullptr;
curl_slist *headers = nullptr;
uv_timer_t *timer = nullptr;
enum : bool { PreemptImmediately, ExponentialBackoff } strategy = PreemptImmediately;
int attempts = 0;
static const int maxAttempts = 4;
char error[CURL_ERROR_SIZE];
};
struct Socket {
private:
uv_poll_t poll;
public:
HTTPCURLContext *context = nullptr;
const curl_socket_t sockfd = 0;
public:
Socket(HTTPCURLContext *context_, curl_socket_t sockfd_) : context(context_), sockfd(sockfd_) {
assert(context);
uv_poll_init_socket(context->loop, &poll, sockfd);
poll.data = this;
}
void start(int events, uv_poll_cb cb) {
uv_poll_start(&poll, events, cb);
}
void stop() {
assert(poll.data);
uv_poll_stop(&poll);
uv_close((uv_handle_t *)&poll, [](uv_handle_t *handle) {
assert(handle->data);
delete reinterpret_cast<Socket *>(handle->data);
});
}
private:
// Make the destructor private to ensure that we can only close the Socket
// with stop(), and disallow manual deletion.
~Socket() = default;
};
// -------------------------------------------------------------------------------------------------
template<> pthread_key_t ThreadContext<HTTPCURLContext>::key{};
template<> pthread_once_t ThreadContext<HTTPCURLContext>::once = PTHREAD_ONCE_INIT;
HTTPCURLContext::HTTPCURLContext(uv_loop_t *loop_) : HTTPContext(loop_) {
if (curl_global_init(CURL_GLOBAL_ALL)) {
throw std::runtime_error("Could not init cURL");
}
timeout = new uv_timer_t;
timeout->data = this;
uv_timer_init(loop, timeout);
share = curl_share_init();
multi = curl_multi_init();
handleError(curl_multi_setopt(multi, CURLMOPT_SOCKETFUNCTION, handleSocket));
handleError(curl_multi_setopt(multi, CURLMOPT_SOCKETDATA, this));
handleError(curl_multi_setopt(multi, CURLMOPT_TIMERFUNCTION, startTimeout));
handleError(curl_multi_setopt(multi, CURLMOPT_TIMERDATA, this));
}
HTTPCURLContext::~HTTPCURLContext() {
curl_multi_cleanup(multi);
multi = nullptr;
curl_share_cleanup(share);
share = nullptr;
uv_timer_stop(timeout);
uv::close(timeout);
}
CURL *HTTPCURLContext::getHandle() {
if (!handles.empty()) {
auto handle = handles.front();
handles.pop();
return handle;
} else {
return curl_easy_init();
}
}
void HTTPCURLContext::returnHandle(CURL *handle) {
curl_easy_reset(handle);
handles.push(handle);
}
void HTTPCURLContext::checkMultiInfo() {
MBGL_VERIFY_THREAD(tid);
CURLMsg *message = nullptr;
int pending = 0;
while ((message = curl_multi_info_read(multi, &pending))) {
switch (message->msg) {
case CURLMSG_DONE: {
HTTPRequestImpl *baton = nullptr;
curl_easy_getinfo(message->easy_handle, CURLINFO_PRIVATE, (char *)&baton);
assert(baton);
baton->handleResult(message->data.result);
} break;
default:
// This should never happen, because there are no other message types.
throw std::runtime_error("CURLMsg returned unknown message type");
}
}
}
void HTTPCURLContext::perform(uv_poll_t *req, int /* status */, int events) {
assert(req->data);
auto socket = reinterpret_cast<Socket *>(req->data);
auto context = socket->context;
MBGL_VERIFY_THREAD(context->tid);
int flags = 0;
if (events & UV_READABLE) {
flags |= CURL_CSELECT_IN;
}
if (events & UV_WRITABLE) {
flags |= CURL_CSELECT_OUT;
}
int running_handles = 0;
curl_multi_socket_action(context->multi, socket->sockfd, flags, &running_handles);
context->checkMultiInfo();
}
int HTTPCURLContext::handleSocket(CURL * /* handle */, curl_socket_t s, int action, void *userp,
void *socketp) {
auto socket = reinterpret_cast<Socket *>(socketp);
assert(userp);
auto context = reinterpret_cast<HTTPCURLContext *>(userp);
MBGL_VERIFY_THREAD(context->tid);
if (!socket && action != CURL_POLL_REMOVE) {
socket = new Socket(context, s);
curl_multi_assign(context->multi, s, (void *)socket);
}
switch (action) {
case CURL_POLL_IN:
socket->start(UV_READABLE, perform);
break;
case CURL_POLL_OUT:
socket->start(UV_WRITABLE, perform);
break;
case CURL_POLL_REMOVE:
if (socket) {
socket->stop();
curl_multi_assign(context->multi, s, nullptr);
}
break;
default:
throw std::runtime_error("Unhandled CURL socket action");
}
return 0;
}
#if UV_VERSION_MAJOR == 0 && UV_VERSION_MINOR <= 10
void HTTPCURLContext::onTimeout(uv_timer_t *req, int /* status */) {
#else
void HTTPCURLContext::onTimeout(uv_timer_t *req) {
#endif
assert(req->data);
auto context = reinterpret_cast<HTTPCURLContext *>(req->data);
MBGL_VERIFY_THREAD(context->tid);
int running_handles;
CURLMcode error = curl_multi_socket_action(context->multi, CURL_SOCKET_TIMEOUT, 0, &running_handles);
if (error != CURLM_OK) {
throw std::runtime_error(std::string("CURL multi error: ") + curl_multi_strerror(error));
}
context->checkMultiInfo();
}
int HTTPCURLContext::startTimeout(CURLM * /* multi */, long timeout_ms, void *userp) {
assert(userp);
auto context = reinterpret_cast<HTTPCURLContext *>(userp);
MBGL_VERIFY_THREAD(context->tid);
if (timeout_ms < 0) {
// A timeout of 0 ms means that the timer will invoked in the next loop iteration.
timeout_ms = 0;
}
uv_timer_stop(context->timeout);
uv_timer_start(context->timeout, onTimeout, timeout_ms, 0);
return 0;
}
// -------------------------------------------------------------------------------------------------
#ifdef __ANDROID__
// This function is called to load the CA bundle
// from http://curl.haxx.se/libcurl/c/cacertinmem.html¯
static CURLcode sslctx_function(CURL * /* curl */, void *sslctx, void * /* parm */) {
int error = 0;
struct zip *apk = zip_open(mbgl::android::apkPath.c_str(), 0, &error);
if (apk == nullptr) {
return CURLE_SSL_CACERT_BADFILE;
}
struct zip_file *apkFile = zip_fopen(apk, "assets/ca-bundle.crt", ZIP_FL_NOCASE);
if (apkFile == nullptr) {
zip_close(apk);
apk = nullptr;
return CURLE_SSL_CACERT_BADFILE;
}
struct zip_stat stat;
if (zip_stat(apk, "assets/ca-bundle.crt", ZIP_FL_NOCASE, &stat) != 0) {
zip_fclose(apkFile);
apkFile = nullptr;
zip_close(apk);
apk = nullptr;
return CURLE_SSL_CACERT_BADFILE;
}
if (stat.size > std::numeric_limits<int>::max()) {
zip_fclose(apkFile);
apkFile = nullptr;
zip_close(apk);
apk = nullptr;
return CURLE_SSL_CACERT_BADFILE;
}
const auto pem = util::make_unique<char[]>(stat.size);
if (static_cast<zip_uint64_t>(zip_fread(apkFile, reinterpret_cast<void *>(pem.get()), stat.size)) != stat.size) {
zip_fclose(apkFile);
apkFile = nullptr;
zip_close(apk);
apk = nullptr;
return CURLE_SSL_CACERT_BADFILE;
}
// get a pointer to the X509 certificate store (which may be empty!)
X509_STORE *store = SSL_CTX_get_cert_store((SSL_CTX *)sslctx);
if (store == nullptr) {
return CURLE_SSL_CACERT_BADFILE;
}
// get a BIO
BIO *bio = BIO_new_mem_buf(pem.get(), static_cast<int>(stat.size));
if (bio == nullptr) {
store = nullptr;
return CURLE_SSL_CACERT_BADFILE;
}
// use it to read the PEM formatted certificate from memory into an X509
// structure that SSL can use
X509 *cert = nullptr;
while (PEM_read_bio_X509(bio, &cert, 0, nullptr) != nullptr) {
if (cert == nullptr) {
BIO_free(bio);
bio = nullptr;
store = nullptr;
return CURLE_SSL_CACERT_BADFILE;
}
// add our certificate to this store
if (X509_STORE_add_cert(store, cert) == 0) {
X509_free(cert);
cert = nullptr;
BIO_free(bio);
bio = nullptr;
store = nullptr;
return CURLE_SSL_CACERT_BADFILE;
}
X509_free(cert);
cert = nullptr;
}
// decrease reference counts
BIO_free(bio);
bio = nullptr;
zip_fclose(apkFile);
apkFile = nullptr;
zip_close(apk);
apk = nullptr;
// all set to go
return CURLE_OK;
}
#endif
HTTPRequestImpl::HTTPRequestImpl(HTTPRequest *request_, uv_loop_t *loop, std::shared_ptr<const Response> response_)
: context(HTTPCURLContext::Get(loop)),
request(request_),
existingResponse(response_),
handle(context->getHandle()) {
assert(request);
context->addRequest(request);
// Zero out the error buffer.
memset(error, 0, sizeof(error));
// If there's already a response, set the correct etags/modified headers to make sure we are
// getting a 304 response if possible. This avoids redownloading unchanged data.
if (existingResponse) {
if (!existingResponse->etag.empty()) {
const std::string header = std::string("If-None-Match: ") + existingResponse->etag;
headers = curl_slist_append(headers, header.c_str());
} else if (existingResponse->modified) {
const std::string time =
std::string("If-Modified-Since: ") + util::rfc1123(existingResponse->modified);
headers = curl_slist_append(headers, time.c_str());
}
}
if (headers) {
curl_easy_setopt(handle, CURLOPT_HTTPHEADER, headers);
}
handleError(curl_easy_setopt(handle, CURLOPT_PRIVATE, this));
handleError(curl_easy_setopt(handle, CURLOPT_ERRORBUFFER, error));
#ifdef __ANDROID__
handleError(curl_easy_setopt(handle, CURLOPT_SSLCERTTYPE, "PEM"));
handleError(curl_easy_setopt(handle, CURLOPT_SSL_CTX_FUNCTION, sslctx_function));
#else
handleError(curl_easy_setopt(handle, CURLOPT_CAINFO, "ca-bundle.crt"));
#endif
handleError(curl_easy_setopt(handle, CURLOPT_FOLLOWLOCATION, 1));
handleError(curl_easy_setopt(handle, CURLOPT_URL, request->resource.url.c_str()));
handleError(curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, writeCallback));
handleError(curl_easy_setopt(handle, CURLOPT_WRITEDATA, this));
handleError(curl_easy_setopt(handle, CURLOPT_HEADERFUNCTION, headerCallback));
handleError(curl_easy_setopt(handle, CURLOPT_HEADERDATA, this));
handleError(curl_easy_setopt(handle, CURLOPT_ACCEPT_ENCODING, "gzip, deflate"));
handleError(curl_easy_setopt(handle, CURLOPT_USERAGENT, "MapboxGL/1.0"));
handleError(curl_easy_setopt(handle, CURLOPT_SHARE, context->share));
start();
}
void HTTPRequestImpl::abandon() {
if (request) {
context->removeRequest(request);
request = nullptr;
}
}
void HTTPRequestImpl::start() {
// Count up the attempts.
attempts++;
// Start requesting the information.
handleError(curl_multi_add_handle(context->multi, handle));
}
HTTPRequestImpl::~HTTPRequestImpl() {
MBGL_VERIFY_THREAD(tid);
if (request) {
context->removeRequest(request);
request->ptr = nullptr;
}
handleError(curl_multi_remove_handle(context->multi, handle));
context->returnHandle(handle);
handle = nullptr;
if (timer) {
// Stop the backoff timer to avoid re-triggering this request.
uv_timer_stop(timer);
uv::close(timer);
timer = nullptr;
}
if (headers) {
curl_slist_free_all(headers);
headers = nullptr;
}
}
// This function is called when we have new data for a request. We just append it to the string
// containing the previous data.
size_t HTTPRequestImpl::writeCallback(void *const contents, const size_t size, const size_t nmemb, void *userp) {
assert(userp);
auto impl = reinterpret_cast<HTTPRequestImpl *>(userp);
MBGL_VERIFY_THREAD(impl->tid);
if (!impl->response) {
impl->response = util::make_unique<Response>();
}
impl->response->data.append((char *)contents, size * nmemb);
return size * nmemb;
}
// Compares the beginning of the (non-zero-terminated!) data buffer with the (zero-terminated!)
// header string. If the data buffer contains the header string at the beginning, it returns
// the length of the header string == begin of the value, otherwise it returns npos.
// The comparison of the header is ASCII-case-insensitive.
size_t headerMatches(const char *const header, const char *const buffer, const size_t length) {
const size_t headerLength = strlen(header);
if (length < headerLength) {
return std::string::npos;
}
size_t i = 0;
while (i < length && i < headerLength && std::tolower(buffer[i]) == std::tolower(header[i])) {
i++;
}
return i == headerLength ? i : std::string::npos;
}
int64_t parseCacheControl(const char *value) {
if (value) {
unsigned long long seconds = 0;
// TODO: cache-control may contain other information as well:
// http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9
if (std::sscanf(value, "max-age=%llu", &seconds) == 1) {
return std::chrono::duration_cast<std::chrono::seconds>(
SystemClock::now().time_since_epoch()).count() +
seconds;
}
}
return 0;
}
size_t HTTPRequestImpl::headerCallback(char *const buffer, const size_t size, const size_t nmemb, void *userp) {
assert(userp);
auto baton = reinterpret_cast<HTTPRequestImpl *>(userp);
MBGL_VERIFY_THREAD(baton->tid);
if (!baton->response) {
baton->response = util::make_unique<Response>();
}
const size_t length = size * nmemb;
size_t begin = std::string::npos;
if ((begin = headerMatches("last-modified: ", buffer, length)) != std::string::npos) {
// Always overwrite the modification date; We might already have a value here from the
// Date header, but this one is more accurate.
const std::string value { buffer + begin, length - begin - 2 }; // remove \r\n
baton->response->modified = curl_getdate(value.c_str(), nullptr);
} else if ((begin = headerMatches("etag: ", buffer, length)) != std::string::npos) {
baton->response->etag = { buffer + begin, length - begin - 2 }; // remove \r\n
} else if ((begin = headerMatches("cache-control: ", buffer, length)) != std::string::npos) {
const std::string value { buffer + begin, length - begin - 2 }; // remove \r\n
baton->response->expires = parseCacheControl(value.c_str());
} else if ((begin = headerMatches("expires: ", buffer, length)) != std::string::npos) {
const std::string value { buffer + begin, length - begin - 2 }; // remove \r\n
baton->response->expires = curl_getdate(value.c_str(), nullptr);
}
return length;
}
void HTTPRequestImpl::retry(uint64_t timeout) {
handleError(curl_multi_remove_handle(context->multi, handle));
response.reset();
assert(!timer);
timer = new uv_timer_t;
timer->data = this;
uv_timer_init(context->loop, timer);
uv_timer_start(timer, restart, timeout, 0);
}
void HTTPRequestImpl::retryImmediately() {
// All batons get notified when the network status changed, but some of them
// might not actually wait for the network to become available again.
if (timer && strategy == PreemptImmediately) {
// Triggers the timer upon the next event loop iteration.
uv_timer_stop(timer);
uv_timer_start(timer, restart, 0, 0);
}
}
#if UV_VERSION_MAJOR == 0 && UV_VERSION_MINOR <= 10
void HTTPRequestImpl::restart(uv_timer_t *timer, int) {
#else
void HTTPRequestImpl::restart(uv_timer_t *timer) {
#endif
// Restart the request.
auto baton = reinterpret_cast<HTTPRequestImpl *>(timer->data);
// Get rid of the timer.
baton->timer = nullptr;
uv::close(timer);
baton->start();
}
void HTTPRequestImpl::finish(ResponseStatus status) {
if (status == ResponseStatus::TemporaryError && attempts < maxAttempts) {
strategy = ExponentialBackoff;
return retry((1 << (attempts - 1)) * 1000);
} else if (status == ResponseStatus::ConnectionError && attempts < maxAttempts) {
// By default, we will retry every 30 seconds (network change notification will
// preempt the timeout).
strategy = PreemptImmediately;
return retry(30000);
}
// Actually return the response.
if (status == ResponseStatus::NotModified) {
request->notify(std::move(response), FileCache::Hint::Refresh);
} else {
request->notify(std::move(response), FileCache::Hint::Full);
}
delete request;
delete this;
}
void HTTPRequestImpl::handleResult(CURLcode code) {
MBGL_VERIFY_THREAD(tid);
if (!request) {
// In this case, it doesn't make sense to even process the response even further since
// the request was canceled anyway.
delete this;
return;
}
// Make sure a response object exists in case we haven't got any headers
// or content.
if (!response) {
response = util::make_unique<Response>();
}
// Add human-readable error code
if (code != CURLE_OK) {
response->status = Response::Error;
response->message = std::string { curl_easy_strerror(code) } + ": " + error;
switch (code) {
case CURLE_COULDNT_RESOLVE_PROXY:
case CURLE_COULDNT_RESOLVE_HOST:
case CURLE_COULDNT_CONNECT:
return finish(ResponseStatus::ConnectionError);
case CURLE_OPERATION_TIMEDOUT:
return finish(ResponseStatus::TemporaryError);
default:
return finish(ResponseStatus::PermanentError);
}
} else {
long responseCode = 0;
curl_easy_getinfo(handle, CURLINFO_RESPONSE_CODE, &responseCode);
if (responseCode == 304) {
if (existingResponse) {
// We're going to copy over the existing response's data.
response->status = existingResponse->status;
response->message = existingResponse->message;
response->modified = existingResponse->modified;
response->etag = existingResponse->etag;
response->data = existingResponse->data;
return finish(ResponseStatus::NotModified);
} else {
// This is an unsolicited 304 response and should only happen on malfunctioning
// HTTP servers. It likely doesn't include any data, but we don't have much options.
response->status = Response::Successful;
return finish(ResponseStatus::Successful);
}
} else if (responseCode == 200) {
response->status = Response::Successful;
return finish(ResponseStatus::Successful);
} else if (responseCode >= 500 && responseCode < 600) {
// Server errors may be temporary, so back off exponentially.
response->status = Response::Error;
response->message = "HTTP status code " + std::to_string(responseCode);
return finish(ResponseStatus::TemporaryError);
} else {
// We don't know how to handle any other errors, so declare them as permanently failing.
response->status = Response::Error;
response->message = "HTTP status code " + std::to_string(responseCode);
return finish(ResponseStatus::PermanentError);
}
}
throw std::runtime_error("Response hasn't been handled");
}
// -------------------------------------------------------------------------------------------------
HTTPRequest::HTTPRequest(DefaultFileSource::Impl *source_, const Resource &resource_)
: SharedRequestBase(source_, resource_) {
}
HTTPRequest::~HTTPRequest() {
MBGL_VERIFY_THREAD(tid);
if (ptr) {
reinterpret_cast<HTTPRequestImpl *>(ptr)->abandon();
}
}
void HTTPRequest::start(uv_loop_t *loop, std::shared_ptr<const Response> response) {
MBGL_VERIFY_THREAD(tid);
assert(!ptr);
ptr = new HTTPRequestImpl(this, loop, response);
}
void HTTPRequest::retryImmediately() {
MBGL_VERIFY_THREAD(tid);
if (ptr) {
reinterpret_cast<HTTPRequestImpl *>(ptr)->retryImmediately();
}
}
void HTTPRequest::cancel() {
MBGL_VERIFY_THREAD(tid);
if (ptr) {
delete reinterpret_cast<HTTPRequestImpl *>(ptr);
ptr = nullptr;
}
delete this;
}
}