| // Copyright (c) 2012 The Chromium OS 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 "shill/http_proxy.h" |
| |
| #include <errno.h> |
| #include <netinet/in.h> |
| #include <linux/if.h> // Needs definitions from netinet/in.h |
| #include <stdio.h> |
| #include <time.h> |
| |
| #include <string> |
| #include <vector> |
| |
| #include <base/logging.h> |
| #include <base/string_number_conversions.h> |
| #include <base/string_split.h> |
| #include <base/string_util.h> |
| #include <base/stringprintf.h> |
| |
| #include "shill/async_connection.h" |
| #include "shill/connection.h" |
| #include "shill/dns_client.h" |
| #include "shill/event_dispatcher.h" |
| #include "shill/ip_address.h" |
| #include "shill/sockets.h" |
| |
| using base::StringPrintf; |
| using std::string; |
| using std::vector; |
| |
| namespace shill { |
| |
| const int HTTPProxy::kClientHeaderTimeoutSeconds = 1; |
| const int HTTPProxy::kConnectTimeoutSeconds = 10; |
| const int HTTPProxy::kDNSTimeoutSeconds = 5; |
| const int HTTPProxy::kDefaultServerPort = 80; |
| const int HTTPProxy::kInputTimeoutSeconds = 30; |
| const size_t HTTPProxy::kMaxClientQueue = 10; |
| const size_t HTTPProxy::kMaxHeaderCount = 128; |
| const size_t HTTPProxy::kMaxHeaderSize = 2048; |
| const int HTTPProxy::kTransactionTimeoutSeconds = 600; |
| |
| const char HTTPProxy::kHTTPMethodConnect[] = "connect"; |
| const char HTTPProxy::kHTTPMethodTerminator[] = " "; |
| const char HTTPProxy::kHTTPURLDelimiters[] = " /#?"; |
| const char HTTPProxy::kHTTPURLPrefix[] = "http://"; |
| const char HTTPProxy::kHTTPVersionPrefix[] = " HTTP/1"; |
| const char HTTPProxy::kInternalErrorMsg[] = "Proxy Failed: Internal Error"; |
| |
| HTTPProxy::HTTPProxy(ConnectionRefPtr connection) |
| : state_(kStateIdle), |
| connection_(connection), |
| accept_callback_(NewCallback(this, &HTTPProxy::AcceptClient)), |
| connect_completion_callback_( |
| NewCallback(this, &HTTPProxy::OnConnectCompletion)), |
| dns_client_callback_(NewCallback(this, &HTTPProxy::GetDNSResult)), |
| read_client_callback_(NewCallback(this, &HTTPProxy::ReadFromClient)), |
| read_server_callback_(NewCallback(this, &HTTPProxy::ReadFromServer)), |
| write_client_callback_(NewCallback(this, &HTTPProxy::WriteToClient)), |
| write_server_callback_(NewCallback(this, &HTTPProxy::WriteToServer)), |
| task_factory_(this), |
| dispatcher_(NULL), |
| dns_client_(NULL), |
| proxy_port_(-1), |
| proxy_socket_(-1), |
| server_async_connection_(NULL), |
| sockets_(NULL), |
| client_socket_(-1), |
| server_port_(kDefaultServerPort), |
| server_socket_(-1), |
| is_route_requested_(false), |
| idle_timeout_(NULL) { } |
| |
| HTTPProxy::~HTTPProxy() { |
| Stop(); |
| } |
| |
| bool HTTPProxy::Start(EventDispatcher *dispatcher, |
| Sockets *sockets) { |
| VLOG(3) << "In " << __func__; |
| |
| if (sockets_) { |
| // We are already running. |
| return true; |
| } |
| |
| proxy_socket_ = sockets->Socket(PF_INET, SOCK_STREAM, 0); |
| if (proxy_socket_ < 0) { |
| PLOG(ERROR) << "Failed to open proxy socket"; |
| return false; |
| } |
| |
| struct sockaddr_in addr; |
| socklen_t addrlen = sizeof(addr); |
| memset(&addr, 0, sizeof(addr)); |
| addr.sin_family = AF_INET; |
| addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); |
| if (sockets->Bind(proxy_socket_, |
| reinterpret_cast<struct sockaddr *>(&addr), |
| sizeof(addr)) < 0 || |
| sockets->GetSockName(proxy_socket_, |
| reinterpret_cast<struct sockaddr *>(&addr), |
| &addrlen) < 0 || |
| sockets->SetNonBlocking(proxy_socket_) < 0 || |
| sockets->Listen(proxy_socket_, kMaxClientQueue) < 0) { |
| sockets->Close(proxy_socket_); |
| proxy_socket_ = -1; |
| PLOG(ERROR) << "HTTPProxy socket setup failed"; |
| return false; |
| } |
| |
| accept_handler_.reset( |
| dispatcher->CreateReadyHandler(proxy_socket_, IOHandler::kModeInput, |
| accept_callback_.get())); |
| dispatcher_ = dispatcher; |
| dns_client_.reset(new DNSClient(IPAddress::kFamilyIPv4, |
| connection_->interface_name(), |
| connection_->dns_servers(), |
| kDNSTimeoutSeconds * 1000, |
| dispatcher, |
| dns_client_callback_.get())); |
| proxy_port_ = ntohs(addr.sin_port); |
| server_async_connection_.reset( |
| new AsyncConnection(connection_->interface_name(), dispatcher, sockets, |
| connect_completion_callback_.get())); |
| sockets_ = sockets; |
| state_ = kStateWaitConnection; |
| return true; |
| } |
| |
| void HTTPProxy::Stop() { |
| VLOG(3) << "In " << __func__; |
| |
| if (!sockets_ ) { |
| return; |
| } |
| |
| StopClient(); |
| |
| accept_handler_.reset(); |
| dispatcher_ = NULL; |
| dns_client_.reset(); |
| proxy_port_ = -1; |
| server_async_connection_.reset(); |
| sockets_->Close(proxy_socket_); |
| proxy_socket_ = -1; |
| sockets_ = NULL; |
| state_ = kStateIdle; |
| } |
| |
| // IOReadyHandler callback routine fired when a client connects to the |
| // proxy's socket. We Accept() the client and start reading a request |
| // from it. |
| void HTTPProxy::AcceptClient(int fd) { |
| VLOG(3) << "In " << __func__; |
| |
| int client_fd = sockets_->Accept(fd, NULL, NULL); |
| if (client_fd < 0) { |
| PLOG(ERROR) << "Client accept failed"; |
| return; |
| } |
| |
| accept_handler_->Stop(); |
| |
| client_socket_ = client_fd; |
| |
| sockets_->SetNonBlocking(client_socket_); |
| read_client_handler_.reset( |
| dispatcher_->CreateInputHandler(client_socket_, |
| read_client_callback_.get())); |
| // Overall transaction timeout. |
| dispatcher_->PostDelayedTask( |
| task_factory_.NewRunnableMethod(&HTTPProxy::StopClient), |
| kTransactionTimeoutSeconds * 1000); |
| |
| state_ = kStateReadClientHeader; |
| StartIdleTimeout(); |
| } |
| |
| bool HTTPProxy::ConnectServer(const IPAddress &address, int port) { |
| state_ = kStateConnectServer; |
| if (!server_async_connection_->Start(address, port)) { |
| SendClientError(500, "Could not create socket to connect to server"); |
| return false; |
| } |
| StartIdleTimeout(); |
| return true; |
| } |
| |
| // DNSClient callback that fires when the DNS request completes. |
| void HTTPProxy::GetDNSResult(const Error &error, const IPAddress &address) { |
| if (!error.IsSuccess()) { |
| SendClientError(502, string("Could not resolve hostname: ") + |
| error.message()); |
| return; |
| } |
| ConnectServer(address, server_port_); |
| } |
| |
| // IOReadyHandler callback routine which fires when the asynchronous Connect() |
| // to the remote server completes (or fails). |
| void HTTPProxy::OnConnectCompletion(bool success, int fd) { |
| if (!success) { |
| SendClientError(500, string("Socket connection delayed failure: ") + |
| server_async_connection_->error()); |
| return; |
| } |
| server_socket_ = fd; |
| state_ = kStateTunnelData; |
| |
| // If this was a "CONNECT" request, notify the client that the connection |
| // has been established by sending an "OK" response. |
| if (LowerCaseEqualsASCII(client_method_, kHTTPMethodConnect)) { |
| SetClientResponse(200, "OK", "", ""); |
| StartReceive(); |
| } |
| |
| StartTransmit(); |
| } |
| |
| // Read through the header lines from the client, modifying or adding |
| // lines as necessary. Perform final determination of the hostname/port |
| // we should connect to and either start a DNS request or connect to a |
| // numeric address. |
| bool HTTPProxy::ParseClientRequest() { |
| VLOG(3) << "In " << __func__; |
| |
| string host; |
| bool found_via = false; |
| bool found_connection = false; |
| for (vector<string>::iterator it = client_headers_.begin(); |
| it != client_headers_.end(); ++it) { |
| if (StartsWithASCII(*it, "Host:", false)) { |
| host = it->substr(5); |
| } else if (StartsWithASCII(*it, "Via:", false)) { |
| found_via = true; |
| (*it).append(StringPrintf(", %s shill-proxy", client_version_.c_str())); |
| } else if (StartsWithASCII(*it, "Connection:", false)) { |
| found_connection = true; |
| (*it).assign("Connection: close"); |
| } else if (StartsWithASCII(*it, "Proxy-Connection:", false)) { |
| (*it).assign("Proxy-Connection: close"); |
| } |
| } |
| |
| if (!found_connection) { |
| client_headers_.push_back("Connection: close"); |
| } |
| if (!found_via) { |
| client_headers_.push_back( |
| StringPrintf("Via: %s shill-proxy", client_version_.c_str())); |
| } |
| |
| // Assemble the request as it will be sent to the server. |
| client_data_.Clear(); |
| if (!LowerCaseEqualsASCII(client_method_, kHTTPMethodConnect)) { |
| for (vector<string>::iterator it = client_headers_.begin(); |
| it != client_headers_.end(); ++it) { |
| client_data_.Append(ByteString(*it + "\r\n", false)); |
| } |
| client_data_.Append(ByteString(string("\r\n"), false)); |
| } |
| |
| TrimWhitespaceASCII(host, TRIM_ALL, &host); |
| if (host.empty()) { |
| // Revert to using the hostname in the URL if no "Host:" header exists. |
| host = server_hostname_; |
| } |
| |
| if (host.empty()) { |
| SendClientError(400, "I don't know what host you want me to connect to"); |
| return false; |
| } |
| |
| server_port_ = 80; |
| vector<string> host_parts; |
| base::SplitString(host, ':', &host_parts); |
| |
| if (host_parts.size() > 2) { |
| SendClientError(400, "Too many colons in hostname"); |
| return false; |
| } else if (host_parts.size() == 2) { |
| server_hostname_ = host_parts[0]; |
| if (!base::StringToInt(host_parts[1], &server_port_)) { |
| SendClientError(400, "Could not parse port number"); |
| return false; |
| } |
| } else { |
| server_hostname_ = host; |
| } |
| |
| connection_->RequestRouting(); |
| is_route_requested_ = true; |
| |
| IPAddress addr(IPAddress::kFamilyIPv4); |
| if (addr.SetAddressFromString(server_hostname_)) { |
| if (!ConnectServer(addr, server_port_)) { |
| return false; |
| } |
| } else { |
| VLOG(3) << "Looking up host: " << server_hostname_; |
| Error error; |
| if (!dns_client_->Start(server_hostname_, &error)) { |
| SendClientError(502, "Could not resolve hostname: " + error.message()); |
| return false; |
| } |
| state_ = kStateLookupServer; |
| } |
| return true; |
| } |
| |
| // Accept a new line into the client headers. Returns false if a parse |
| // error occurs. |
| bool HTTPProxy::ProcessLastHeaderLine() { |
| string *header = &client_headers_.back(); |
| TrimString(*header, "\r", header); |
| |
| if (header->empty()) { |
| // Empty line terminates client headers. |
| client_headers_.pop_back(); |
| if (!ParseClientRequest()) { |
| return false; |
| } |
| } |
| |
| // Is this is the first header line? |
| if (client_headers_.size() == 1) { |
| if (!ReadClientHTTPMethod(header) || |
| !ReadClientHTTPVersion(header) || |
| !ReadClientHostname(header)) { |
| return false; |
| } |
| } |
| |
| if (client_headers_.size() >= kMaxHeaderCount) { |
| SendClientError(500, kInternalErrorMsg); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| // Split input from client into header lines, and consume parsed lines |
| // from InputData. The passed in |data| is modified to indicate the |
| // characters consumed. |
| bool HTTPProxy::ReadClientHeaders(InputData *data) { |
| unsigned char *ptr = data->buf; |
| unsigned char *end = ptr + data->len; |
| |
| if (client_headers_.empty()) { |
| client_headers_.push_back(string()); |
| } |
| |
| for (; ptr < end && state_ == kStateReadClientHeader; ++ptr) { |
| if (*ptr == '\n') { |
| if (!ProcessLastHeaderLine()) { |
| return false; |
| } |
| |
| // Start a new line. New chararacters we receive will be appended there. |
| client_headers_.push_back(string()); |
| continue; |
| } |
| |
| string *header = &client_headers_.back(); |
| // Is the first character of the header line a space or tab character? |
| if (header->empty() && (*ptr == ' ' || *ptr == '\t') && |
| client_headers_.size() > 1) { |
| // Line Continuation: Add this character to the previous header line. |
| // This way, all of the data (including newlines and line continuation |
| // characters) related to a specific header will be contained within |
| // a single element of |client_headers_|, and manipulation of headers |
| // such as appending will be simpler. This is accomplished by removing |
| // the empty line we started, and instead appending the whitespace |
| // and following characters to the previous line. |
| client_headers_.pop_back(); |
| header = &client_headers_.back(); |
| header->append("\r\n"); |
| } |
| |
| if (header->length() >= kMaxHeaderSize) { |
| SendClientError(500, kInternalErrorMsg); |
| return false; |
| } |
| header->push_back(*ptr); |
| } |
| |
| // Return the remaining data to the caller -- this could be POST data |
| // or other non-header data sent with the client request. |
| data->buf = ptr; |
| data->len = end - ptr; |
| |
| return true; |
| } |
| |
| // Finds the URL in the first line of an HTTP client header, and extracts |
| // and removes the hostname (and port) from the URL. Returns false if a |
| // parse error occurs, and true otherwise (whether or not the hostname was |
| // found). |
| bool HTTPProxy::ReadClientHostname(string *header) { |
| const string http_url_prefix(kHTTPURLPrefix); |
| size_t url_idx = header->find(http_url_prefix); |
| if (url_idx != string::npos) { |
| size_t host_start = url_idx + http_url_prefix.length(); |
| size_t host_end = |
| header->find_first_of(kHTTPURLDelimiters, host_start); |
| if (host_end != string::npos) { |
| server_hostname_ = header->substr(host_start, |
| host_end - host_start); |
| // Modify the URL passed upstream to remove "http://<hostname>". |
| header->erase(url_idx, host_end - url_idx); |
| if ((*header)[url_idx] != '/') { |
| header->insert(url_idx, "/"); |
| } |
| } else { |
| LOG(ERROR) << "Could not find end of hostname in request. Line was: " |
| << *header; |
| SendClientError(500, kInternalErrorMsg); |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| bool HTTPProxy::ReadClientHTTPMethod(string *header) { |
| size_t method_end = header->find(kHTTPMethodTerminator); |
| if (method_end == string::npos || method_end == 0) { |
| LOG(ERROR) << "Could not parse HTTP method. Line was: " << *header; |
| SendClientError(501, "Server could not parse HTTP method"); |
| return false; |
| } |
| client_method_ = header->substr(0, method_end); |
| return true; |
| } |
| |
| // Extract the HTTP version number from the first line of the client headers. |
| // Returns true if found. |
| bool HTTPProxy::ReadClientHTTPVersion(string *header) { |
| const string http_version_prefix(kHTTPVersionPrefix); |
| size_t http_ver_pos = header->find(http_version_prefix); |
| if (http_ver_pos != string::npos) { |
| client_version_ = |
| header->substr(http_ver_pos + http_version_prefix.length() - 1); |
| } else { |
| SendClientError(501, "Server only accepts HTTP/1.x requests"); |
| return false; |
| } |
| return true; |
| } |
| |
| // IOInputHandler callback that fires when data is read from the client. |
| // This could be header data, or perhaps POST data that follows the headers. |
| void HTTPProxy::ReadFromClient(InputData *data) { |
| VLOG(3) << "In " << __func__ << " length " << data->len; |
| |
| if (data->len == 0) { |
| // EOF from client. |
| StopClient(); |
| return; |
| } |
| |
| if (state_ == kStateReadClientHeader) { |
| if (!ReadClientHeaders(data)) { |
| return; |
| } |
| if (state_ == kStateReadClientHeader) { |
| // Still consuming client headers; restart the input timer. |
| StartIdleTimeout(); |
| return; |
| } |
| } |
| |
| // Check data->len again since ReadClientHeaders() may have consumed some |
| // part of it. |
| if (data->len != 0) { |
| // The client sent some information after its headers. Buffer the client |
| // input and temporarily disable input events from the client. |
| client_data_.Append(ByteString(data->buf, data->len)); |
| read_client_handler_->Stop(); |
| StartTransmit(); |
| } |
| } |
| |
| // IOInputHandler callback which fires when data has been read from the |
| // server. |
| void HTTPProxy::ReadFromServer(InputData *data) { |
| VLOG(3) << "In " << __func__ << " length " << data->len; |
| if (data->len == 0) { |
| // Server closed connection. |
| if (server_data_.IsEmpty()) { |
| StopClient(); |
| return; |
| } |
| state_ = kStateFlushResponse; |
| } else { |
| read_server_handler_->Stop(); |
| } |
| |
| server_data_.Append(ByteString(data->buf, data->len)); |
| |
| StartTransmit(); |
| } |
| |
| // Return an HTTP error message back to the client. |
| void HTTPProxy::SendClientError(int code, const string &error) { |
| VLOG(3) << "In " << __func__; |
| LOG(ERROR) << "Sending error " << error; |
| SetClientResponse(code, "ERROR", "text/plain", error); |
| state_ = kStateFlushResponse; |
| StartTransmit(); |
| } |
| |
| // Create an HTTP response message to be sent to the client. |
| void HTTPProxy::SetClientResponse(int code, const string &type, |
| const string &content_type, |
| const string &message) { |
| string content_line; |
| if (!message.empty() && !content_type.empty()) { |
| content_line = StringPrintf("Content-Type: %s\r\n", content_type.c_str()); |
| } |
| string response = StringPrintf("HTTP/1.1 %d %s\r\n" |
| "%s\r\n" |
| "%s", code, type.c_str(), |
| content_line.c_str(), |
| message.c_str()); |
| server_data_ = ByteString(response, false); |
| } |
| |
| // Start a timeout for "the next event". This timeout augments the overall |
| // transaction timeout to make sure there is some activity occurring at |
| // reasonable intervals. |
| void HTTPProxy::StartIdleTimeout() { |
| int timeout_seconds = 0; |
| switch (state_) { |
| case kStateReadClientHeader: |
| timeout_seconds = kClientHeaderTimeoutSeconds; |
| break; |
| case kStateConnectServer: |
| timeout_seconds = kConnectTimeoutSeconds; |
| break; |
| case kStateLookupServer: |
| // DNSClient has its own internal timeout, so we need not set one here. |
| timeout_seconds = 0; |
| break; |
| default: |
| timeout_seconds = kInputTimeoutSeconds; |
| break; |
| } |
| if (idle_timeout_) { |
| idle_timeout_->Cancel(); |
| idle_timeout_ = NULL; |
| } |
| if (timeout_seconds != 0) { |
| idle_timeout_ = task_factory_.NewRunnableMethod(&HTTPProxy::StopClient); |
| dispatcher_->PostDelayedTask(idle_timeout_, timeout_seconds * 1000); |
| } |
| } |
| |
| // Start the various input handlers. Listen for new data only if we have |
| // completely written the last data we've received to the other end. |
| void HTTPProxy::StartReceive() { |
| if (state_ == kStateTunnelData && client_data_.IsEmpty()) { |
| read_client_handler_->Start(); |
| } |
| if (server_data_.IsEmpty()) { |
| if (state_ == kStateTunnelData) { |
| if (read_server_handler_.get()) { |
| read_server_handler_->Start(); |
| } else { |
| read_server_handler_.reset( |
| dispatcher_->CreateInputHandler(server_socket_, |
| read_server_callback_.get())); |
| } |
| } else if (state_ == kStateFlushResponse) { |
| StopClient(); |
| return; |
| } |
| } |
| StartIdleTimeout(); |
| } |
| |
| // Start the various output-ready handlers for the endpoints we have |
| // data waiting for. |
| void HTTPProxy::StartTransmit() { |
| if (state_ == kStateTunnelData && !client_data_.IsEmpty()) { |
| if (write_server_handler_.get()) { |
| write_server_handler_->Start(); |
| } else { |
| write_server_handler_.reset( |
| dispatcher_->CreateReadyHandler(server_socket_, |
| IOHandler::kModeOutput, |
| write_server_callback_.get())); |
| } |
| } |
| if ((state_ == kStateFlushResponse || state_ == kStateTunnelData) && |
| !server_data_.IsEmpty()) { |
| if (write_client_handler_.get()) { |
| write_client_handler_->Start(); |
| } else { |
| write_client_handler_.reset( |
| dispatcher_->CreateReadyHandler(client_socket_, |
| IOHandler::kModeOutput, |
| write_client_callback_.get())); |
| } |
| } |
| StartIdleTimeout(); |
| } |
| |
| // End the transaction with the current client, restart the IOHandler |
| // which alerts us to new clients connecting. This function is called |
| // during various error conditions and is a callback for all timeouts. |
| void HTTPProxy::StopClient() { |
| VLOG(3) << "In " << __func__; |
| |
| if (is_route_requested_) { |
| connection_->ReleaseRouting(); |
| is_route_requested_ = false; |
| } |
| write_client_handler_.reset(); |
| read_client_handler_.reset(); |
| if (client_socket_ != -1) { |
| sockets_->Close(client_socket_); |
| client_socket_ = -1; |
| } |
| client_headers_.clear(); |
| client_method_.clear(); |
| client_version_.clear(); |
| server_port_ = kDefaultServerPort; |
| write_server_handler_.reset(); |
| read_server_handler_.reset(); |
| if (server_socket_ != -1) { |
| sockets_->Close(server_socket_); |
| server_socket_ = -1; |
| } |
| server_hostname_.clear(); |
| client_data_.Clear(); |
| server_data_.Clear(); |
| dns_client_->Stop(); |
| server_async_connection_->Stop(); |
| task_factory_.RevokeAll(); |
| idle_timeout_ = NULL; |
| accept_handler_->Start(); |
| state_ = kStateWaitConnection; |
| } |
| |
| // Output ReadyHandler callback which fires when the client socket is |
| // ready for data to be sent to it. |
| void HTTPProxy::WriteToClient(int fd) { |
| CHECK_EQ(client_socket_, fd); |
| int ret = sockets_->Send(fd, server_data_.GetConstData(), |
| server_data_.GetLength(), 0); |
| VLOG(3) << "In " << __func__ << " wrote " << ret << " of " << |
| server_data_.GetLength(); |
| if (ret < 0) { |
| LOG(ERROR) << "Server write failed"; |
| StopClient(); |
| return; |
| } |
| |
| server_data_ = ByteString(server_data_.GetConstData() + ret, |
| server_data_.GetLength() - ret); |
| |
| if (server_data_.IsEmpty()) { |
| write_client_handler_->Stop(); |
| } |
| |
| StartReceive(); |
| } |
| |
| // Output ReadyHandler callback which fires when the server socket is |
| // ready for data to be sent to it. |
| void HTTPProxy::WriteToServer(int fd) { |
| CHECK_EQ(server_socket_, fd); |
| int ret = sockets_->Send(fd, client_data_.GetConstData(), |
| client_data_.GetLength(), 0); |
| VLOG(3) << "In " << __func__ << " wrote " << ret << " of " << |
| client_data_.GetLength(); |
| |
| if (ret < 0) { |
| LOG(ERROR) << "Client write failed"; |
| StopClient(); |
| return; |
| } |
| |
| client_data_ = ByteString(client_data_.GetConstData() + ret, |
| client_data_.GetLength() - ret); |
| |
| if (client_data_.IsEmpty()) { |
| write_server_handler_->Stop(); |
| } |
| |
| StartReceive(); |
| } |
| |
| } // namespace shill |