connection.cc

/**
 * @file connection.cpp
 * @brief implementation of the connection class
 * @author Daniel Schauenberg <d@unwiredcouch.com>
 */

#include "restclient-cpp/connection.h"

#include <curl/curl.h>

#include <cstring>
#include <string>
#include <iostream>
#include <map>
#include <stdexcept>
#include <utility>

#include "restclient-cpp/restclient.h"
#include "restclient-cpp/helpers.h"
#include "restclient-cpp/version.h"

/**
 * @brief constructor for the Connection object
 *
 * @param baseUrl - base URL for the connection to use
 *
 */
RestClient::Connection::Connection(const std::string& baseUrl)
                               : headerFields(), lastRequest() {
  this->curlHandle = curl_easy_init();
  if (!this->curlHandle) {
    throw std::runtime_error("Couldn't initialize curl handle");
  }
  this->baseUrl = baseUrl;
  this->timeout = 0;
  this->followRedirects = false;
  this->maxRedirects = -1l;
  this->noSignal = false;
  this->progressFn = NULL;
  this->progressFnData = NULL;
  this->writeCallback = RestClient::Helpers::write_callback;
  this->verifyPeer = true;
}

/**
 * @brief Getter used to ensure NULL handle is not used.
 *
 */
CURL* RestClient::Connection::getCurlHandle() {
  if (this->curlHandle) {
    return this->curlHandle;
  }
  throw std::runtime_error("Connection terminated");
}

void RestClient::Connection::Terminate() {
  if (this->curlHandle) {
    curl_easy_cleanup(this->curlHandle);
  }
  this->curlHandle = NULL;
}

RestClient::Connection::~Connection() {
  this->Terminate();
}

// getters/setters

/**
 * @brief get diagnostic information about the connection object
 *
 * @return RestClient::Connection::Info struct
 */
RestClient::Connection::Info
RestClient::Connection::GetInfo() {
  RestClient::Connection::Info ret;
  ret.baseUrl = this->baseUrl;
  ret.headers = this->GetHeaders();
  ret.timeout = this->timeout;
  ret.followRedirects = this->followRedirects;
  ret.maxRedirects = this->maxRedirects;
  ret.noSignal = this->noSignal;
  ret.progressFn = this->progressFn;
  ret.progressFnData = this->progressFnData;
  ret.basicAuth.username = this->basicAuth.username;
  ret.basicAuth.password = this->basicAuth.password;
  ret.customUserAgent = this->customUserAgent;
  ret.lastRequest = this->lastRequest;

  ret.certPath = this->certPath;
  ret.certType = this->certType;
  ret.keyPath = this->keyPath;
  ret.keyPassword = this->keyPassword;

  ret.uriProxy = this->uriProxy;
  ret.unixSocketPath = this->unixSocketPath;

  return ret;
}

/**
 * @brief append a header to the internal map
 *
 * @param key for the header field
 * @param value for the header field
 *
 */
void
RestClient::Connection::AppendHeader(const std::string& key,
                                     const std::string& value) {
  this->headerFields[key] = value;
}

/**
 * @brief set the custom headers map. This will replace the currently
 * configured headers with the provided ones. If you want to add additional
 * headers, use AppendHeader()
 *
 * @param headers to set
 */
void
RestClient::Connection::SetHeaders(RestClient::HeaderFields headers) {
#if __cplusplus >= 201103L
  this->headerFields = std::move(headers);
#else
  this->headerFields = headers;
#endif
}

/**
 * @brief get all custom headers set on the connection
 *
 * @returns a RestClient::HeaderFields map containing the custom headers
 */
RestClient::HeaderFields
RestClient::Connection::GetHeaders() {
  return this->headerFields;
}

/**
 * @brief configure whether to follow redirects on this connection
 *
 * @param follow - boolean whether to follow redirects
 * @param maxRedirects - int indicating the maximum number of redirect to follow (-1 unlimited, default)
 */
void
RestClient::Connection::FollowRedirects(bool follow, int maxRedirects) {
  this->followRedirects = follow;
  this->maxRedirects = maxRedirects;
}

/**
 * @brief set custom user agent for connection. This gets prepended to the
 * default restclient-cpp/RESTCLIENT_VERSION string
 *
 * @param userAgent - custom userAgent prefix
 *
 */
void
RestClient::Connection::SetUserAgent(const std::string& userAgent) {
  this->customUserAgent = userAgent;
}

/**
 * @brief set custom Certificate Authority (CA) path
 *
 * @param caInfoFilePath - The path to a file holding the certificates used to
 * verify the peer with. See CURLOPT_CAINFO
 *
 */
void
RestClient::Connection::SetCAInfoFilePath(const std::string& caInfoFilePath) {
  this->caInfoFilePath = caInfoFilePath;
}

/**
 * @brief get the user agent to add to the request
 *
 * @return user agent as std::string
 */
std::string
RestClient::Connection::GetUserAgent() {
  std::string prefix;
  if (this->customUserAgent.length() > 0) {
    prefix = this->customUserAgent + " ";
  }
  return std::string(prefix + "restclient-cpp/" + RESTCLIENT_VERSION);
}

/**
 * @brief set timeout for connection
 *
 * @param seconds - timeout in seconds
 *
 */
void
RestClient::Connection::SetTimeout(int seconds) {
  this->timeout = seconds;
}

/**
 * @brief switch off curl signals for connection (see CURLOPT_NONSIGNAL). By
 * default signals are used, except when timeout is given.
 *
 * @param no - set to true switches signals off
 *
 */
void
RestClient::Connection::SetNoSignal(bool no) {
  this->noSignal = no;
}

/**
 * @brief set file progress callback function
 *
 * @param callback function pointer
 *
 */
void
RestClient::Connection::SetFileProgressCallback(curl_progress_callback
                                                progressFn) {
  this->progressFn = progressFn;
}

/**
 * @brief set file progress callback data
 *
 * @param callback data pointer
 *
 */
void
RestClient::Connection::SetFileProgressCallbackData(void* data) {
  this->progressFnData = data;
}

/**
 * @brief set username and password for basic auth
 *
 * @param username
 * @param password
 *
 */
void
RestClient::Connection::SetBasicAuth(const std::string& username,
                                     const std::string& password) {
  this->basicAuth.username = username;
  this->basicAuth.password = password;
}

/**
 * @brief set certificate path
 *
 * @param path to certificate file
 *
 */
void
RestClient::Connection::SetCertPath(const std::string& cert) {
  this->certPath = cert;
}

/**
 * @brief set certificate type
 *
 * @param certificate type (e.g. "PEM" or "DER")
 *
 */
void
RestClient::Connection::SetCertType(const std::string& certType) {
  this->certType = certType;
}

/**
 * @brief set key path
 *
 * @param path to key file
 *
 */
void
RestClient::Connection::SetKeyPath(const std::string& keyPath) {
  this->keyPath = keyPath;
}

/**
 * @brief set key password
 *
 * @param key password
 *
 */
void
RestClient::Connection::SetKeyPassword(const std::string& keyPassword) {
  this->keyPassword = keyPassword;
}

/**
 * @brief set SSL peer verification flag
 *
 * @param boolean (default is true)
 *
 */
void
RestClient::Connection::SetVerifyPeer(bool verifyPeer) {
  this->verifyPeer = verifyPeer;
}

/**
 * @brief set HTTP proxy address and port
 *
 * @param proxy address with port number
 *
 */
void
RestClient::Connection::SetProxy(const std::string& uriProxy) {
  std::string uriProxyUpper = uriProxy;
  // check if the provided address is prefixed with "http"
  std::transform(uriProxyUpper.begin(), uriProxyUpper.end(),
    uriProxyUpper.begin(), ::toupper);

  if ((uriProxy.length() > 0) && (uriProxyUpper.compare(0, 4, "HTTP") != 0)) {
    this->uriProxy = "http://" + uriProxy;
  } else {
    this->uriProxy = uriProxy;
  }
}

/**
 * @brief set custom Unix socket path for connection.
 * See https://curl.haxx.se/libcurl/c/CURLOPT_UNIX_SOCKET_PATH.html
 *
 * @param unixSocketPath - path to Unix socket (ex: /var/run/docker.sock)
 *
 */
void
RestClient::Connection::SetUnixSocketPath(const std::string& unixSocketPath) {
  this->unixSocketPath = unixSocketPath;
}

/**
 * @brief set callback for writing received data.  Last parameter
 * to callback (userdata) points to a RestClient::Response. For details,
 * see https://curl.haxx.se/libcurl/c/CURLOPT_WRITEFUNCTION.html
 *
 * @param write_callback - callback to handle received data
 *
 */
void
RestClient::Connection::SetWriteFunction(RestClient::WriteCallback
writeCallback) {
  this->writeCallback = writeCallback;
}

/**
 * @brief helper function to get called from the actual request methods to
 * prepare the curlHandle for transfer with generic options, perform the
 * request and record some stats from the last request and then reset the
 * handle with curl_easy_reset to its default state. This will keep things
 * like connections and session ID intact but makes sure you can change
 * parameters on the object for another request.
 *
 * @param uri URI to query
 *
 * @return Reference to the Response struct that should be filled
 */
RestClient::Response
RestClient::Connection::performCurlRequest(const std::string& uri) {
  // init return type
  RestClient::Response ret = {};
  performCurlRequest(uri, &ret);
  return ret;
}

/**
 * @brief helper function to get called from the actual request methods to
 * prepare the curlHandle for transfer with generic options, perform the
 * request and record some stats from the last request and then reset the
 * handle with curl_easy_reset to its default state. This will keep things
 * like connections and session ID intact but makes sure you can change
 * parameters on the object for another request.
 *
 * @param uri URI to query
 * @param ret Reference to the response struct that should be filled
 * 
 * @return reference to response struct for chaining
 */
RestClient::Response*
RestClient::Connection::performCurlRequest(const std::string& uri,
                                           RestClient::Response* ret) {
  // init return type
  ret->body.clear();
  ret->code = 0;
  ret->headers.clear();

  std::string url = std::string(this->baseUrl + uri);
  std::string headerString;
  CURLcode res = CURLE_OK;
  curl_slist* headerList = NULL;

  /** set query URL */
  curl_easy_setopt(getCurlHandle(), CURLOPT_URL, url.c_str());
  /** set callback function */
  curl_easy_setopt(getCurlHandle(), CURLOPT_WRITEFUNCTION,
                   this->writeCallback);
  /** set data object to pass to callback function */
  curl_easy_setopt(getCurlHandle(), CURLOPT_WRITEDATA, ret);
  /** set the header callback function */
  curl_easy_setopt(getCurlHandle(), CURLOPT_HEADERFUNCTION,
                   Helpers::header_callback);
  /** callback object for headers */
  curl_easy_setopt(getCurlHandle(), CURLOPT_HEADERDATA, ret);
  /** set http headers */
  for (HeaderFields::const_iterator it = this->headerFields.begin();
      it != this->headerFields.end(); ++it) {
    headerString = it->first;
    headerString += ": ";
    headerString += it->second;
    headerList = curl_slist_append(headerList, headerString.c_str());
  }
  curl_easy_setopt(getCurlHandle(), CURLOPT_HTTPHEADER,
      headerList);

  // set basic auth if configured
  if (this->basicAuth.username.length() > 0) {
    std::string authString = std::string(this->basicAuth.username + ":" +
                                         this->basicAuth.password);
    curl_easy_setopt(getCurlHandle(), CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
    curl_easy_setopt(getCurlHandle(), CURLOPT_USERPWD, authString.c_str());
  }
  /** set error buffer */
  curl_easy_setopt(getCurlHandle(), CURLOPT_ERRORBUFFER,
                   this->curlErrorBuf);

  /** set user agent */
  curl_easy_setopt(getCurlHandle(), CURLOPT_USERAGENT,
                   this->GetUserAgent().c_str());

  // set timeout
  if (this->timeout) {
    curl_easy_setopt(getCurlHandle(), CURLOPT_TIMEOUT, this->timeout);
    // dont want to get a sig alarm on timeout
    curl_easy_setopt(getCurlHandle(), CURLOPT_NOSIGNAL, 1);
  }
  // set follow redirect
  if (this->followRedirects == true) {
    curl_easy_setopt(getCurlHandle(), CURLOPT_FOLLOWLOCATION, 1L);
    curl_easy_setopt(getCurlHandle(), CURLOPT_MAXREDIRS,
                     static_cast<int64_t>(this->maxRedirects));
  }

  if (this->noSignal) {
    // multi-threaded and prevent entering foreign signal handler (e.g. JNI)
    curl_easy_setopt(getCurlHandle(), CURLOPT_NOSIGNAL, 1);
  }

  // set file progress callback
  if (this->progressFn) {
    curl_easy_setopt(getCurlHandle(), CURLOPT_NOPROGRESS, 0);
    curl_easy_setopt(getCurlHandle(),
                     CURLOPT_PROGRESSFUNCTION,
                    this->progressFn);
    if (this->progressFnData) {
      curl_easy_setopt(getCurlHandle(),
                       CURLOPT_PROGRESSDATA,
                       this->progressFnData);
    } else {
      curl_easy_setopt(getCurlHandle(),
                       CURLOPT_PROGRESSDATA,
                       this);
    }
  }

  // if provided, supply CA path
  if (!this->caInfoFilePath.empty()) {
    curl_easy_setopt(getCurlHandle(), CURLOPT_CAINFO,
                     this->caInfoFilePath.c_str());
  }

  // set cert file path
  if (!this->certPath.empty()) {
    curl_easy_setopt(getCurlHandle(), CURLOPT_SSLCERT,
                     this->certPath.c_str());
  }

  // set cert type
  if (!this->certType.empty()) {
    curl_easy_setopt(getCurlHandle(), CURLOPT_SSLCERTTYPE,
                     this->certType.c_str());
  }
  // set key file path
  if (!this->keyPath.empty()) {
    curl_easy_setopt(getCurlHandle(), CURLOPT_SSLKEY,
                     this->keyPath.c_str());
  }
  // set key password
  if (!this->keyPassword.empty()) {
    curl_easy_setopt(getCurlHandle(), CURLOPT_KEYPASSWD,
                     this->keyPassword.c_str());
  }

  // set peer verification
  if (!this->verifyPeer) {
    curl_easy_setopt(getCurlHandle(), CURLOPT_SSL_VERIFYPEER,
                     this->verifyPeer);
  }

  // set web proxy address
  if (!this->uriProxy.empty()) {
    curl_easy_setopt(getCurlHandle(), CURLOPT_PROXY,
                     uriProxy.c_str());
    curl_easy_setopt(getCurlHandle(), CURLOPT_HTTPPROXYTUNNEL,
                     1L);
  }

  // set Unix socket path, if requested
  if (!this->unixSocketPath.empty()) {
    curl_easy_setopt(getCurlHandle(), CURLOPT_UNIX_SOCKET_PATH,
                     this->unixSocketPath.c_str());
  }

  res = curl_easy_perform(getCurlHandle());
  this->lastRequest.curlCode = res;
  if (res != CURLE_OK) {
    int retCode = res;
    if (retCode > 99) {
      retCode = -1;
    }
    ret->code = retCode;
    ret->body = curl_easy_strerror(res);
  } else {
    int64_t http_code = 0;
    curl_easy_getinfo(getCurlHandle(), CURLINFO_RESPONSE_CODE, &http_code);
    ret->code = static_cast<int>(http_code);
  }

  this->lastRequest.curlError = std::string(this->curlErrorBuf);

  curl_easy_getinfo(getCurlHandle(), CURLINFO_TOTAL_TIME,
                    &this->lastRequest.totalTime);
  curl_easy_getinfo(getCurlHandle(), CURLINFO_NAMELOOKUP_TIME,
                    &this->lastRequest.nameLookupTime);
  curl_easy_getinfo(getCurlHandle(), CURLINFO_CONNECT_TIME,
                    &this->lastRequest.connectTime);
  curl_easy_getinfo(getCurlHandle(), CURLINFO_APPCONNECT_TIME,
                    &this->lastRequest.appConnectTime);
  curl_easy_getinfo(getCurlHandle(), CURLINFO_PRETRANSFER_TIME,
                    &this->lastRequest.preTransferTime);
  curl_easy_getinfo(getCurlHandle(), CURLINFO_STARTTRANSFER_TIME,
                    &this->lastRequest.startTransferTime);
  curl_easy_getinfo(getCurlHandle(), CURLINFO_REDIRECT_TIME,
                    &this->lastRequest.redirectTime);
  curl_easy_getinfo(getCurlHandle(), CURLINFO_REDIRECT_COUNT,
                    &this->lastRequest.redirectCount);
  // free header list
  curl_slist_free_all(headerList);
  // reset curl handle
  curl_easy_reset(getCurlHandle());
  return ret;
}

/**
 * @brief HTTP GET method
 *
 * @param url to query
 *
 * @return response struct
 */
RestClient::Response
RestClient::Connection::get(const std::string& url) {
  return this->performCurlRequest(url);
}
/**
 * @brief HTTP GET method
 *
 * @param url to query
 * @param response struct
 * 
 * @return response struct ref for chaining
 */
RestClient::Response*
RestClient::Connection::get(const std::string& url,
                            RestClient::Response* response) {
  return this->performCurlRequest(url, response);
}
/**
 * @brief HTTP POST method
 *
 * @param url to query
 * @param data HTTP POST body
 *
 * @return response struct
 */
RestClient::Response
RestClient::Connection::post(const std::string& url,
                             const std::string& data) {
  /** Now specify we want to POST data */
  curl_easy_setopt(getCurlHandle(), CURLOPT_POST, 1L);
  /** set post fields */
  curl_easy_setopt(getCurlHandle(), CURLOPT_POSTFIELDS, data.c_str());
  curl_easy_setopt(getCurlHandle(), CURLOPT_POSTFIELDSIZE, data.size());

  return this->performCurlRequest(url);
}
/**
 * @brief HTTP PUT method
 *
 * @param url to query
 * @param data HTTP PUT body
 *
 * @return response struct
 */
RestClient::Response
RestClient::Connection::put(const std::string& url,
                            const std::string& data) {
  /** initialize upload object */
  RestClient::Helpers::UploadObject up_obj;
  up_obj.data = data.c_str();
  up_obj.length = data.size();

  /** Now specify we want to PUT data */
  curl_easy_setopt(getCurlHandle(), CURLOPT_PUT, 1L);
  curl_easy_setopt(getCurlHandle(), CURLOPT_UPLOAD, 1L);
  /** set read callback function */
  curl_easy_setopt(getCurlHandle(), CURLOPT_READFUNCTION,
                   RestClient::Helpers::read_callback);
  /** set data object to pass to callback function */
  curl_easy_setopt(getCurlHandle(), CURLOPT_READDATA, &up_obj);
  /** set data size */
  curl_easy_setopt(getCurlHandle(), CURLOPT_INFILESIZE,
                     static_cast<int64_t>(up_obj.length));

  return this->performCurlRequest(url);
}
/**
 * @brief HTTP PATCH method
 *
 * @param url to query
 * @param data HTTP PATCH body
 *
 * @return response struct
 */
RestClient::Response
RestClient::Connection::patch(const std::string& url,
                            const std::string& data) {
  /** initialize upload object */
  RestClient::Helpers::UploadObject up_obj;
  up_obj.data = data.c_str();
  up_obj.length = data.size();

  /** we want HTTP PATCH */
  const char* http_patch = "PATCH";

  /** set HTTP PATCH METHOD */
  curl_easy_setopt(getCurlHandle(), CURLOPT_CUSTOMREQUEST, http_patch);
  curl_easy_setopt(getCurlHandle(), CURLOPT_UPLOAD, 1L);
  /** set read callback function */
  curl_easy_setopt(getCurlHandle(), CURLOPT_READFUNCTION,
                   RestClient::Helpers::read_callback);
  /** set data object to pass to callback function */
  curl_easy_setopt(getCurlHandle(), CURLOPT_READDATA, &up_obj);
  /** set data size */
  curl_easy_setopt(getCurlHandle(), CURLOPT_INFILESIZE,
                     static_cast<int64_t>(up_obj.length));

  return this->performCurlRequest(url);
}
/**
 * @brief HTTP DELETE method
 *
 * @param url to query
 *
 * @return response struct
 */
RestClient::Response
RestClient::Connection::del(const std::string& url) {
  /** we want HTTP DELETE */
  const char* http_delete = "DELETE";

  /** set HTTP DELETE METHOD */
  curl_easy_setopt(getCurlHandle(), CURLOPT_CUSTOMREQUEST, http_delete);

  return this->performCurlRequest(url);
}

/**
 * @brief HTTP HEAD method
 *
 * @param url to query
 *
 * @return response struct
 */
RestClient::Response
RestClient::Connection::head(const std::string& url) {
    /** we want HTTP HEAD */
    const char* http_head = "HEAD";

    /** set HTTP HEAD METHOD */
    curl_easy_setopt(getCurlHandle(), CURLOPT_CUSTOMREQUEST, http_head);
    curl_easy_setopt(getCurlHandle(), CURLOPT_NOBODY, 1L);

    return this->performCurlRequest(url);
}

/**
 * @brief HTTP OPTIONS method
 *
 * @param url to query
 *
 * @return response struct
 */
RestClient::Response
RestClient::Connection::options(const std::string& url) {
    /** we want HTTP OPTIONS */
    const char* http_options = "OPTIONS";

    /** set HTTP HEAD METHOD */
    curl_easy_setopt(getCurlHandle(), CURLOPT_CUSTOMREQUEST, http_options);
    curl_easy_setopt(getCurlHandle(), CURLOPT_NOBODY, 1L);

    return this->performCurlRequest(url);
}