blob: bbba898682b8ff0c80bd8ffd32509419eaa570e5 [file] [log] [blame]
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <stdint.h>
#include <memory>
#include <string>
#include <vector>
#include "base/callback.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/threading/thread_checker.h"
#include "net/url_request/url_fetcher_delegate.h"
#include "url/gurl.h"
namespace client_update_protocol {
class Ecdsa;
namespace net {
class URLFetcher;
namespace update_client {
class Configurator;
// Sends a request to one of the urls provided. The class implements a chain
// of responsibility design pattern, where the urls are tried in the order they
// are specified, until the request to one of them succeeds or all have failed.
// CUP signing is optional.
class RequestSender : public net::URLFetcherDelegate {
// If |error| is 0, then the response is provided in the |response| parameter.
// |retry_after_sec| contains the value of the X-Retry-After response header,
// when the response was received from a cryptographically secure URL. The
// range for this value is [-1, 86400]. If |retry_after_sec| is -1 it means
// that the header could not be found, or trusted, or had an invalid value.
// The upper bound represents a delay of one day.
using RequestSenderCallback = base::OnceCallback<
void(int error, const std::string& response, int retry_after_sec)>;
// This value is chosen not to conflict with network errors defined by
// net/base/net_error_list.h. The callers don't have to handle this error in
// any meaningful way, but this value may be reported in UMA stats, therefore
// avoiding collisions with known network errors is desirable.
enum : int { kErrorResponseNotTrusted = -10000 };
explicit RequestSender(const scoped_refptr<Configurator>& config);
~RequestSender() override;
// |use_signing| enables CUP signing of protocol messages exchanged using
// this class.
void Send(bool use_signing,
const std::string& request_body,
const std::vector<GURL>& urls,
RequestSenderCallback request_sender_callback);
// Combines the |url| and |query_params| parameters.
static GURL BuildUpdateUrl(const GURL& url, const std::string& query_params);
// Decodes and returns the public key used by CUP.
static std::string GetKey(const char* key_bytes_base64);
// Returns the string value of a header of the server response or an empty
// string if the header is not available.
static std::string GetStringHeaderValue(const net::URLFetcher* source,
const char* header_name);
// Returns the integral value of a header of the server response or -1 if
// if the header is not available or a conversion error has occured.
static int64_t GetInt64HeaderValue(const net::URLFetcher* source,
const char* header_name);
// Overrides for URLFetcherDelegate.
void OnURLFetchComplete(const net::URLFetcher* source) override;
// Implements the error handling and url fallback mechanism.
void SendInternal();
// Called when SendInternal completes. |response_body| and |response_etag|
// contain the body and the etag associated with the HTTP response.
void SendInternalComplete(int error,
const std::string& response_body,
const std::string& response_etag,
int retry_after_sec);
// Helper function to handle a non-continuable error in Send.
void HandleSendError(int error, int retry_after_sec);
base::ThreadChecker thread_checker_;
const scoped_refptr<Configurator> config_;
bool use_signing_; // True if CUP signing is used.
std::vector<GURL> urls_;
std::string request_body_;
RequestSenderCallback request_sender_callback_;
std::string public_key_;
std::vector<GURL>::const_iterator cur_url_;
std::unique_ptr<net::URLFetcher> url_fetcher_;
std::unique_ptr<client_update_protocol::Ecdsa> signer_;
} // namespace update_client