A utility driver for doing client/server HTTP transaction...

net/tools/fetch/http_listen_socket.cc

+// Copyright (c) 2009 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 "base/compiler_specific.h"
+#include "base/message_loop.h"
+#include "base/string_util.h"
+#include "net/tools/fetch/http_listen_socket.h"
+#include "net/tools/fetch/http_server_request_info.h"
+#include "net/tools/fetch/http_server_response_info.h"
+
+// must run in the IO thread
+HttpListenSocket::HttpListenSocket(SOCKET s, 
+    HttpListenSocket::Delegate* delegate)
+    : ALLOW_THIS_IN_INITIALIZER_LIST(ListenSocket(s, this)),
+      delegate_(delegate) {
+}
+
+// must run in the IO thread
+HttpListenSocket::~HttpListenSocket() {
+}
+
+void HttpListenSocket::Accept() {
+  SOCKET conn = ListenSocket::Accept(socket_);
+  DCHECK(conn != INVALID_SOCKET);
+  if (conn == INVALID_SOCKET) {
+    // TODO
+  } else {
+    scoped_refptr<HttpListenSocket> sock =
+        new HttpListenSocket(conn, delegate_);
+    // it's up to the delegate to AddRef if it wants to keep it around
+    DidAccept(this, sock);
+  }
+}
+
+HttpListenSocket* HttpListenSocket::Listen(const std::string& ip, int port,
+                                           HttpListenSocket::Delegate* delegate) {
+  SOCKET s = ListenSocket::Listen(ip, port);
+  if (s == INVALID_SOCKET) {
+    // TODO (ibrar): error handling
+  } else {
+    HttpListenSocket *serv = new HttpListenSocket(s, delegate);
+    serv->Listen();
+    return serv;
+  }
+  return NULL;
+}
+
+//
+// HTTP Request Parser
+// This HTTP request parser uses a simple state machine to quickly parse
+// through the headers.  The parser is not 100% complete, as it is designed
+// for use in this simple test driver.
+//
+// Known issues:
+//   - does not handle whitespace on first HTTP line correctly.  Expects
+//     a single space between the method/url and url/protocol.
+
+// Input character types.
+enum header_parse_inputs {
+  INPUT_SPACE,
+  INPUT_CR,
+  INPUT_LF,
+  INPUT_COLON,
+  INPUT_DEFAULT,
+  MAX_INPUTS
+};
+
+// Parser states.
+enum header_parse_states {
+  ST_METHOD,     // Receiving the method
+  ST_URL,        // Receiving the URL
+  ST_PROTO,      // Receiving the protocol
+  ST_HEADER,     // Starting a Request Header
+  ST_NAME,       // Receiving a request header name
+  ST_SEPARATOR,  // Receiving the separator between header name and value
+  ST_VALUE,      // Receiving a request header value
+  ST_DONE,       // Parsing is complete and successful
+  ST_ERR,        // Parsing encountered invalid syntax.
+  MAX_STATES
+};
+
+// State transition table
+int parser_state[MAX_STATES][MAX_INPUTS] = {
+/* METHOD    */ { ST_URL,       ST_ERR,     ST_ERR,  ST_ERR,       ST_METHOD },
+/* URL       */ { ST_PROTO,     ST_ERR,     ST_ERR,  ST_URL,       ST_URL },
+/* PROTOCOL  */ { ST_ERR,       ST_HEADER,  ST_NAME, ST_ERR,       ST_PROTO },
+/* HEADER    */ { ST_ERR,       ST_ERR,     ST_NAME, ST_ERR,       ST_ERR },
+/* NAME      */ { ST_SEPARATOR, ST_DONE,    ST_ERR,  ST_SEPARATOR, ST_NAME },
+/* SEPARATOR */ { ST_SEPARATOR, ST_ERR,     ST_ERR,  ST_SEPARATOR, ST_VALUE },
+/* VALUE     */ { ST_VALUE,     ST_HEADER,  ST_NAME, ST_VALUE,     ST_VALUE },
+/* DONE      */ { ST_DONE,      ST_DONE,    ST_DONE, ST_DONE,      ST_DONE },
+/* ERR       */ { ST_ERR,       ST_ERR,     ST_ERR,  ST_ERR,       ST_ERR }
+};
+
+// Convert an input character to the parser's input token.
+int charToInput(char ch) {
+  switch(ch) {
+    case ' ':
+      return INPUT_SPACE;
+    case '\r':
+      return INPUT_CR;
+    case '\n':
+      return INPUT_LF;
+    case ':':
+      return INPUT_COLON;
+  }
+  return INPUT_DEFAULT;
+}
+
+HttpServerRequestInfo* HttpListenSocket::ParseHeaders() {
+  int pos = 0;
+  int data_len = recv_data_.length();
+  int state = ST_METHOD;
+  HttpServerRequestInfo* info = new HttpServerRequestInfo();
+  std::string buffer;
+  std::string header_name;
+  std::string header_value;
+  while (pos < data_len) {
+    char ch = recv_data_[pos++];
+    int input = charToInput(ch);
+    int next_state = parser_state[state][input];
+
+    bool transition = (next_state != state);
+    if (transition) {
+      // Do any actions based on state transitions.
+      switch (state) {
+        case ST_METHOD:
+          info->method = buffer;
+          buffer.clear();
+          break;
+        case ST_URL:
+          info->url = GURL(buffer);
+          buffer.clear();
+          break;
+        case ST_PROTO:
+          // TODO(mbelshe): Deal better with parsing protocol.
+          DCHECK(buffer == "HTTP/1.1");
+          buffer.clear();
+          break;
+        case ST_NAME:
+          header_name = buffer;
+          buffer.clear();
+          break;
+        case ST_VALUE:
+          header_value = buffer;
+          // TODO(mbelshe): Deal better with duplicate headers
+          DCHECK(info->headers.find(header_name) == info->headers.end());
+          info->headers[header_name] = header_value;
+          buffer.clear();
+          break;
+      }
+      state = next_state;
+    } else {
+      // Do any actions based on current state
+      switch (state) {
+        case ST_METHOD:
+        case ST_URL:
+        case ST_PROTO:
+        case ST_VALUE:
+        case ST_NAME:
+          buffer.append(&ch, 1);
+          break;
+        case ST_DONE:
+          recv_data_ = recv_data_.substr(pos);
+          return info;
+        case ST_ERR:
+          delete info;
+          return NULL;
+      }
+    }
+  }
+  // No more characters, but we haven't finished parsing yet.
+  delete info;
+  return NULL;
+}
+
+void HttpListenSocket::DidAccept(ListenSocket* server,
+                                 ListenSocket* connection) {
+  connection->AddRef();
+}
+
+void HttpListenSocket::DidRead(ListenSocket* connection,
+                               const std::string& data) {
+  recv_data_ += data;
+  while (recv_data_.length()) {
+    HttpServerRequestInfo* request = ParseHeaders();
+    if (!request)
+      break;
+    delegate_->OnRequest(this, request);
+    delete request;
+  }
+}
+
+void HttpListenSocket::DidClose(ListenSocket* sock) {
+  sock->Release();
+}
+
+// Convert the numeric status code to a string.
+// e.g.  200 -> "200 OK"
+std::string ServerStatus(int code) {
+  switch(code) {
+    case 200:
+      return std::string("200 OK");
+    // TODO(mbelshe): handle other codes.
+  }
+  NOTREACHED();
+  return std::string();
+}
+
+void HttpListenSocket::Respond(HttpServerResponseInfo* info,
+                               std::string& data) {
+  std::string response;
+
+  // status line
+  response = info->protocol + " ";
+  response += ServerStatus(info->status);
+  response += "\r\n";
+
+  // standard headers
+  if (info->content_type.length())
+    response += "Content-type: " + info->content_type + "\r\n";
+
+  if (info->content_length > 0)
+    response += "Content-length: " + IntToString(info->content_length) +
+        "\r\n";
+
+  if (info->connection_close)
+    response += "Connection: close\r\n";
+
+  // TODO(mbelshe): support additional headers
+
+  // End of headers
+  response += "\r\n";
+
+  // Add data
+  response += data;
+
+  // Write it all out.
+  this->Send(response, false);
+}