src/modules/m_rpc_json.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2007 InspIRCd Development Team
   6  * See: http://www.inspircd.org/wiki/index.php/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *            the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 #include "inspircd.h"
  15 #include "users.h"
  16 #include "channels.h"
  17 #include "modules.h"
  18 #include "httpd.h"
  19 #include "rpc.h"
  20 #include <exception>
  21
  22 /* $ModDesc: Encode and decode JSON-RPC requests for modules */
  23 /* $ModDep: httpd.h rpc.h */
  24
  25 class JsonException : public std::exception
  26 {
  27  private:
  28         std::string _what;
  29  public:
  30         JsonException(const std::string &what)
  31                 : _what(what)
  32         {
  33         }
  34
  35         virtual ~JsonException() throw() { }
  36
  37         virtual const char *what() const throw()
  38         {
  39                 return _what.c_str();
  40         }
  41 };
  42
  43 class ModuleRpcJson : public Module
  44 {
  45  private:
  46
  47  public:
  48         ModuleRpcJson(InspIRCd *Me) : Module(Me)
  49         {
  50                 ServerInstance->Modules->PublishInterface("RPC", this);
  51         }
  52
  53         virtual ~ModuleRpcJson()
  54         {
  55                 ServerInstance->Modules->UnpublishInterface("RPC", this);
  56         }
  57
  58         virtual Version GetVersion()
  59         {
  60                 return Version(1, 1, 0, 0, VF_SERVICEPROVIDER | VF_VENDOR, API_VERSION);
  61         }
  62
  63         void Implements(char *List)
  64         {
  65                 List[I_OnEvent] = 1;
  66         }
  67
  68         virtual void OnEvent(Event *event)
  69         {
  70                 if (event->GetEventID() == "httpd_url")
  71                 {
  72                         HTTPRequest *req = (HTTPRequest*) event->GetData();
  73
  74                         if ((req->GetURI() == "/rpc/json") || (req->GetURI() == "/rpc/json/"))
  75                         {
  76                                 std::stringstream data;
  77
  78                                 RPCValue *reqobj = NULL;
  79
  80                                 try
  81                                 {
  82                                         reqobj = this->JSONParse(req->GetPostData());
  83
  84                                         if (!reqobj || (reqobj->GetType() != RPCObject))
  85                                                 throw JsonException("RPC requests must be in the form of a single object");
  86
  87                                         RPCValue *method = reqobj->GetObject("method");
  88                                         if (!method || method->GetType() != RPCString)
  89                                                 throw JsonException("RPC requests must have a 'method' string field");
  90
  91                                         RPCValue *params = reqobj->GetObject("params");
  92                                         if (!params || params->GetType() != RPCArray)
  93                                                 throw JsonException("RPC requests must have a 'params' array field");
  94
  95                                         RPCRequest modreq("json", method->GetString(), params);
  96                                         Event mev((char*) &modreq, this, "RPCMethod");
  97                                         mev.Send(ServerInstance);
  98
  99                                         if (!modreq.claimed)
 100                                                 throw JsonException("Unrecognized method");
 101
 102                                         if (!modreq.error.empty())
 103                                         {
 104                                                 data << "{\"result\":null,\"error\":\"" << modreq.error << "\"";
 105                                         }
 106                                         else
 107                                         {
 108                                                 data << "{\"result\":";
 109                                                 this->JSONSerialize(modreq.result, data);
 110                                                 data << ",\"error\":null";
 111                                         }
 112
 113                                         if (reqobj->GetObject("id"))
 114                                         {
 115                                                 data << ",\"id\":";
 116                                                 this->JSONSerialize(reqobj->GetObject("id"), data);
 117                                         }
 118                                         data << "}";
 119
 120                                         delete reqobj;
 121                                         reqobj = NULL;
 122                                 }
 123                                 catch (std::exception &e)
 124                                 {
 125                                         if (reqobj)
 126                                                 delete reqobj;
 127                                         data << "{\"result\":null,\"error\":\"" << e.what() << "\"}";
 128                                 }
 129
 130                                 HTTPDocument response(req->sock, &data, 200);
 131                                 response.headers.SetHeader("X-Powered-By", "m_rpc_json.so");
 132                                 response.headers.SetHeader("Content-Type", "application/json");
 133                                 response.headers.SetHeader("Connection", "Keep-Alive");
 134
 135                                 Request rreq((char*) &response, (Module*) this, event->GetSource());
 136                                 rreq.Send();
 137                         }
 138                 }
 139         }
 140
 141         void AttachToParent(RPCValue *parent, RPCValue *child, const std::string &key = "")
 142         {
 143                 if (!parent || !child)
 144                         return;
 145
 146                 if (parent->GetType() == RPCArray)
 147                         parent->ArrayAdd(child);
 148                 else if (parent->GetType() == RPCObject)
 149                         parent->ObjectAdd(key, child);
 150                 else
 151                         throw JsonException("Cannot add a value to a non-container");
 152         }
 153
 154         void AttachToParentReset(RPCValue *parent, RPCValue *&child, std::string &key)
 155         {
 156                 AttachToParent(parent, child, key);
 157                 child = NULL;
 158                 key.clear();
 159         }
 160
 161         RPCValue *JSONParse(const std::string &data)
 162         {
 163                 bool pisobject = false;
 164                 bool instring = false;
 165                 std::string stmp;
 166                 std::string vkey;
 167                 std::string pvkey;
 168                 RPCValue *aparent = NULL;
 169                 RPCValue *value = NULL;
 170
 171                 for (std::string::const_iterator i = data.begin(); i != data.end(); i++)
 172                 {
 173                         if (instring)
 174                         {
 175                                 // TODO escape sequences
 176                                 if (*i == '"')
 177                                 {
 178                                         instring = false;
 179
 180                                         if (pisobject && vkey.empty())
 181                                                 vkey = stmp;
 182                                         else
 183                                                 value = new RPCValue(stmp);
 184
 185                                         stmp.clear();
 186                                 }
 187                                 else
 188                                         stmp += *i;
 189
 190                                 continue;
 191                         }
 192
 193                         if ((*i == ' ') || (*i == '\t') || (*i == '\r') || (*i == '\n'))
 194                                 continue;
 195
 196                         if (*i == '{')
 197                         {
 198                                 // Begin object
 199                                 if ((value) || (pisobject && vkey.empty()))
 200                                         throw JsonException("Unexpected begin object token ('{')");
 201
 202                                 RPCValue *nobj = new RPCValue(RPCObject, aparent);
 203                                 aparent = nobj;
 204                                 pvkey = vkey;
 205                                 vkey.clear();
 206                                 pisobject = true;
 207                         }
 208                         else if (*i == '}')
 209                         {
 210                                 // End object
 211                                 if ((!aparent) || (!pisobject) || (!vkey.empty() && !value))
 212                                         throw JsonException("Unexpected end object token ('}')");
 213
 214                                 // End value
 215                                 if (value)
 216                                         AttachToParentReset(aparent, value, vkey);
 217
 218                                 if (!aparent->parent)
 219                                         return aparent;
 220
 221                                 value = aparent;
 222                                 aparent = aparent->parent;
 223                                 vkey = pvkey;
 224                                 pvkey.clear();
 225                                 pisobject = (aparent->GetType() == RPCObject);
 226                         }
 227                         else if (*i == '"')
 228                         {
 229                                 // Begin string
 230                                 if (value)
 231                                         throw JsonException("Unexpected begin string token ('\"')");
 232
 233                                 instring = true;
 234                         }
 235                         else if (*i == ':')
 236                         {
 237                                 if ((!aparent) || (!pisobject) || (vkey.empty()) || (value))
 238                                         throw JsonException("Unexpected object value token (':')");
 239                         }
 240                         else if (*i == ',')
 241                         {
 242                                 if ((!aparent) || (!value) || ((pisobject) && (vkey.empty())))
 243                                         throw JsonException("Unexpected value seperator token (',')");
 244
 245                                 AttachToParentReset(aparent, value, vkey);
 246                         }
 247                         else if (*i == '[')
 248                         {
 249                                 // Begin array
 250                                 if ((value) || (pisobject && vkey.empty()))
 251                                         throw JsonException("Unexpected begin array token ('[')");
 252
 253                                 RPCValue *nar = new RPCValue(RPCArray, aparent);
 254                                 aparent = nar;
 255                                 pvkey = vkey;
 256                                 vkey.clear();
 257                                 pisobject = false;
 258                         }
 259                         else if (*i == ']')
 260                         {
 261                                 // End array (also an end value delimiter)
 262                                 if (!aparent || pisobject)
 263                                         throw JsonException("Unexpected end array token (']')");
 264
 265                                 if (value)
 266                                         AttachToParentReset(aparent, value, vkey);
 267
 268                                 if (!aparent->parent)
 269                                         return aparent;
 270
 271                                 value = aparent;
 272                                 aparent = aparent->parent;
 273                                 vkey = pvkey;
 274                                 pvkey.clear();
 275                                 pisobject = (aparent->GetType() == RPCObject);
 276                         }
 277                         else
 278                         {
 279                                 // Numbers, false, null, and true fall under this heading.
 280                                 if ((*i == 't') && ((i + 3) < data.end()) && (*(i + 1) == 'r') && (*(i + 2) == 'u') && (*(i + 3) == 'e'))
 281                                 {
 282                                         value = new RPCValue(true);
 283                                         i += 3;
 284                                 }
 285                                 else if ((*i == 'f') && ((i + 4) < data.end()) && (*(i + 1) == 'a') && (*(i + 2) == 'l') && (*(i + 3) == 's') && (*(i + 4) == 'e'))
 286                                 {
 287                                         value = new RPCValue(false);
 288                                         i += 4;
 289                                 }
 290                                 else if ((*i == 'n') && ((i + 3) < data.end()) && (*(i + 1) == 'u') && (*(i + 2) == 'l') && (*(i + 3) == 'l'))
 291                                 {
 292                                         value = new RPCValue();
 293                                         i += 3;
 294                                 }
 295                                 else if ((*i == '-') || (*i == '+') || (*i == '.') || ((*i >= '0') && (*i <= '9')))
 296                                 {
 297                                         std::string ds = std::string(i, data.end());
 298                                         char *eds = NULL;
 299
 300                                         errno = 0;
 301                                         double v = strtod(ds.c_str(), &eds);
 302
 303                                         if (errno != 0)
 304                                                 throw JsonException("Error parsing numeric value");
 305
 306                                         value = new RPCValue(v);
 307
 308                                         i += eds - ds.c_str() - 1;
 309                                 }
 310                                 else
 311                                         throw JsonException("Unknown data in value portion");
 312                         }
 313                 }
 314
 315                 if (instring)
 316                         throw JsonException("Unterminated string");
 317
 318                 if (aparent && pisobject)
 319                         throw JsonException("Unterminated object");
 320                 else if (aparent && !pisobject)
 321                         throw JsonException("Unterminated array");
 322
 323                 if (value)
 324                         return value;
 325                 else
 326                         throw JsonException("No JSON data found");
 327         }
 328
 329         void JSONSerialize(RPCValue *value, std::stringstream &re)
 330         {
 331                 int ac;
 332                 switch (value->GetType())
 333                 {
 334                         case RPCNull:
 335                                 re << "null";
 336                                 break;
 337                         case RPCBoolean:
 338                                 re << ((value->GetBool()) ? "true" : "false");
 339                                 break;
 340                         case RPCInteger:
 341                                 re << value->GetInt();
 342                                 break;
 343                         case RPCString:
 344                                 re << "\"" << value->GetString() << "\"";
 345                                 break;
 346                         case RPCArray:
 347                                 re << "[";
 348                                 ac = value->ArraySize();
 349                                 for (int i = 0; i < ac; i++)
 350                                 {
 351                                         this->JSONSerialize(value->GetArray(i), re);
 352                                         if (i != (ac - 1))
 353                                                 re << ",";
 354                                 }
 355                                 re << "]";
 356                                 break;
 357                         case RPCObject:
 358                                 re << "{";
 359                                 std::pair<RPCObjectContainer::iterator,RPCObjectContainer::iterator> its = value->GetObjectIterator();
 360                                 while (its.first != its.second)
 361                                 {
 362                                         re << "\"" << its.first->first << "\":";
 363                                         this->JSONSerialize(its.first->second, re);
 364                                         if (++its.first != its.second)
 365                                                 re << ",";
 366                                 }
 367                                 re << "}";
 368                                 break;
 369                 }
 370         }
 371 };
 372
 373 MODULE_INIT(ModuleRpcJson);