extracted http client

src/lib/utils/httpclient.cpp

@@ -0,0 +1,132 @@
+/*
+ * ebusd - daemon for communication with eBUS heating systems.
+ * Copyright (C) 2018 John Baier <ebusd@ebusd.eu>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "lib/utils/httpclient.h"
+#include <cstring>
+#include <cstdlib>
+#include <sstream>
+#include <ios>
+
+namespace ebusd {
+
+using std::string;
+using std::ostringstream;
+using std::dec;
+using std::hex;
+
+bool HttpClient::connect(const string& host, const uint16_t port, const string& userAgent, const int timeout) {
+  if (m_socket) {
+    delete m_socket;
+    m_socket = nullptr;
+  }
+  TCPSocket* socket = m_client.connect(host, port);
+  if (!socket) {
+    return false;
+  }
+  socket->setTimeout(timeout);
+  m_socket = socket;
+  m_host = host;
+  m_userAgent = userAgent;
+  return true;
+}
+
+bool HttpClient::get(const string& uri, const string& body, string& response) {
+  return request("GET", uri, body, response);
+}
+
+bool HttpClient::post(const string& uri, const string& body, string& response) {
+  return request("POST", uri, body, response);
+}
+
+bool HttpClient::request(const string& method, const string& uri, const string& body, string& response) {
+  if (!m_socket) {
+    response = "not connected";
+    return false;
+  }
+  ostringstream ostr;
+  ostr << method << " " << uri << " HTTP/1.0\r\n"
+       << "Host: " << m_host << "\r\n";
+  if (!m_userAgent.empty()) {
+    ostr << "User-Agent: " << m_userAgent << "\r\n";
+  }
+  if (body.empty()) {
+    ostr << "\r\n";
+  } else {
+    ostr << "Content-Type: application/json; charset=utf-8\r\n"
+         << "Content-Length: " << dec << body.length() << "\r\n"
+         << "\r\n"
+         << body;
+  }
+  string str = ostr.str();
+  size_t len = str.size();
+  const char* cstr = str.c_str();
+  for (size_t pos = 0; pos < len; ) {
+    ssize_t sent = m_socket->send(cstr + pos, len - pos);
+    if (sent < 0) {
+      response = "send error";
+      return false;
+    }
+    pos += sent;
+  }
+  if (!m_buffer) {
+    m_buffer = (char *) malloc(1024);
+    if (!m_buffer) {
+      response = "memory allocation";
+      return false;
+    }
+    m_bufferSize = 1024;
+  }
+  ssize_t received = m_socket->recv(m_buffer, m_bufferSize);
+  if (received <= 0) {
+    response = "receive error";
+    return false;
+  }
+  string result = string(m_buffer, 0, static_cast<unsigned>(received)); // expect "HTTP/1.1 200 OK"
+  size_t pos = result.find(' ');
+  if (result.substr(0, 5) != "HTTP/" || pos == string::npos || pos > 8) {
+    response = "receive error (headers)";
+    return false;
+  }
+  if (result.substr(pos+1, 6) != "200 OK") {
+    size_t endpos = result.find("\r\n", pos+1);
+    response = "receive error: " + result.substr(pos+1, endpos == string::npos ? endpos : endpos-pos-1);
+    return false;
+  }
+  pos = result.find("\r\n\r\n");
+  while (pos == string::npos && result.length() < 256*1024) {
+    received = m_socket->recv(m_buffer, m_bufferSize);
+    if (received < 0) {
+      response = "receive error";
+      return false;
+    }
+    if (received == 0) {
+      break;
+    }
+    size_t oldLength = result.length();
+    result += string(m_buffer, 0, static_cast<unsigned>(received));
+    pos = result.find("\r\n\r\n", oldLength - 3);
+  }
+  if (pos == string::npos) {
+    response = "receive error (headers)";
+    return false;
+  }
+  response = result.substr(pos+4);
+  return true;
+}
+
+}  // namespace ebusd