src/modules/m_rpc_json.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2008 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 &swhat)
  31                 : _what(swhat)
  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                 Implementation eventlist[] = { I_OnEvent };
  52                 ServerInstance->Modules->Attach(eventlist, this, 1);
  53         }
  54
  55         virtual ~ModuleRpcJson()
  56         {
  57                 ServerInstance->Modules->UnpublishInterface("RPC", this);
  58         }
  59
  60         virtual Version GetVersion()
  61         {
  62                 return Version(1, 2, 0, 0, VF_SERVICEPROVIDER | VF_VENDOR, API_VERSION);
  63         }
  64
  65
  66         virtual void OnEvent(Event *event)
  67         {
  68                 if (event->GetEventID() == "httpd_url")
  69                 {
  70                         HTTPRequest *req = (HTTPRequest*) event->GetData();
  71
  72                         if ((req->GetURI() == "/rpc/json") || (req->GetURI() == "/rpc/json/"))
  73                         {
  74                                 std::stringstream data;
  75
  76                                 RPCValue *reqobj = NULL;
  77
  78                                 try
  79                                 {
  80                                         reqobj = this->JSONParse(req->GetPostData());
  81
  82                                         if (!reqobj || (reqobj->GetType() != RPCObject))
  83                                                 throw JsonException("RPC requests must be in the form of a single object");
  84
  85                                         RPCValue *method = reqobj->GetObject("method");
  86                                         if (!method || method->GetType() != RPCString)
  87                                                 throw JsonException("RPC requests must have a 'method' string field");
  88
  89                                         RPCValue *params = reqobj->GetObject("params");
  90                                         if (!params || params->GetType() != RPCArray)
  91                                                 throw JsonException("RPC requests must have a 'params' array field");
  92
  93                                         RPCRequest modreq("json", method->GetString(), params);
  94                                         Event mev((char*) &modreq, this, "RPCMethod");
  95                                         mev.Send(ServerInstance);
  96
  97                                         if (!modreq.claimed)
  98                                                 throw JsonException("Unrecognized method");
  99
 100                                         if (!modreq.error.empty())
 101                                         {
 102                                                 data << "{\"result\":null,\"error\":\"" << modreq.error << "\"";
 103                                         }
 104                                         else
 105                                         {
 106                                                 data << "{\"result\":";
 107                                                 this->JSONSerialize(modreq.result, data);
 108                                                 data << ",\"error\":null";
 109                                         }
 110
 111                                         if (reqobj->GetObject("id"))
 112                                         {
 113                                                 data << ",\"id\":";
 114                                                 this->JSONSerialize(reqobj->GetObject("id"), data);
 115                                         }
 116                                         data << "}";
 117
 118                                         delete reqobj;
 119                                         reqobj = NULL;
 120                                 }
 121                                 catch (std::exception &e)
 122                                 {
 123                                         if (reqobj)
 124                                                 delete reqobj;
 125                                         data << "{\"result\":null,\"error\":\"" << e.what() << "\"}";
 126                                 }
 127
 128                                 HTTPDocument response(req->sock, &data, 200);
 129                                 response.headers.SetHeader("X-Powered-By", "m_rpc_json.so");
 130                                 response.headers.SetHeader("Content-Type", "application/json");
 131                                 response.headers.SetHeader("Connection", "Keep-Alive");
 132
 133                                 Request rreq((char*) &response, (Module*) this, event->GetSource());
 134                                 rreq.Send();
 135                         }
 136                 }
 137         }
 138
 139         void AttachToParent(RPCValue *parent, RPCValue *child, const std::string &key = "")
 140         {
 141                 if (!parent || !child)
 142                         return;
 143
 144                 if (parent->GetType() == RPCArray)
 145                         parent->ArrayAdd(child);
 146                 else if (parent->GetType() == RPCObject)
 147                         parent->ObjectAdd(key, child);
 148                 else
 149                         throw JsonException("Cannot add a value to a non-container");
 150         }
 151
 152         void AttachToParentReset(RPCValue *parent, RPCValue *&child, std::string &key)
 153         {
 154                 AttachToParent(parent, child, key);
 155                 child = NULL;
 156                 key.clear();
 157         }
 158
 159         RPCValue *JSONParse(const std::string &data)
 160         {
 161                 bool pisobject = false;
 162                 bool instring = false;
 163                 std::string stmp;
 164                 std::string vkey;
 165                 std::string pvkey;
 166                 RPCValue *aparent = NULL;
 167                 RPCValue *value = NULL;
 168
 169                 for (std::string::const_iterator i = data.begin(); i != data.end(); i++)
 170                 {
 171                         if (instring)
 172                         {
 173                                 // TODO escape sequences
 174                                 if (*i == '"')
 175                                 {
 176                                         instring = false;
 177
 178                                         if (pisobject && vkey.empty())
 179                                                 vkey = stmp;
 180                                         else
 181                                                 value = new RPCValue(stmp);
 182
 183                                         stmp.clear();
 184                                 }
 185                                 else
 186                                         stmp += *i;
 187
 188                                 continue;
 189                         }
 190
 191                         if ((*i == ' ') || (*i == '\t') || (*i == '\r') || (*i == '\n'))
 192                                 continue;
 193
 194                         if (*i == '{')
 195                         {
 196                                 // Begin object
 197                                 if ((value) || (pisobject && vkey.empty()))
 198                                         throw JsonException("Unexpected begin object token ('{')");
 199
 200                                 RPCValue *nobj = new RPCValue(RPCObject, aparent);
 201                                 aparent = nobj;
 202                                 pvkey = vkey;
 203                                 vkey.clear();
 204                                 pisobject = true;
 205                         }
 206                         else if (*i == '}')
 207                         {
 208                                 // End object
 209                                 if ((!aparent) || (!pisobject) || (!vkey.empty() && !value))
 210                                         throw JsonException("Unexpected end object token ('}')");
 211
 212                                 // End value
 213                                 if (value)
 214                                         AttachToParentReset(aparent, value, vkey);
 215
 216                                 if (!aparent->parent)
 217                                         return aparent;
 218
 219                                 value = aparent;
 220                                 aparent = aparent->parent;
 221                                 vkey = pvkey;
 222                                 pvkey.clear();
 223                                 pisobject = (aparent->GetType() == RPCObject);
 224                         }
 225                         else if (*i == '"')
 226                         {
 227                                 // Begin string
 228                                 if (value)
 229                                         throw JsonException("Unexpected begin string token ('\"')");
 230
 231                                 instring = true;
 232                         }
 233                         else if (*i == ':')
 234                         {
 235                                 if ((!aparent) || (!pisobject) || (vkey.empty()) || (value))
 236                                         throw JsonException("Unexpected object value token (':')");
 237                         }
 238                         else if (*i == ',')
 239                         {
 240                                 if ((!aparent) || (!value) || ((pisobject) && (vkey.empty())))
 241                                         throw JsonException("Unexpected value seperator token (',')");
 242
 243                                 AttachToParentReset(aparent, value, vkey);
 244                         }
 245                         else if (*i == '[')
 246                         {
 247                                 // Begin array
 248                                 if ((value) || (pisobject && vkey.empty()))
 249                                         throw JsonException("Unexpected begin array token ('[')");
 250
 251                                 RPCValue *nar = new RPCValue(RPCArray, aparent);
 252                                 aparent = nar;
 253                                 pvkey = vkey;
 254                                 vkey.clear();
 255                                 pisobject = false;
 256                         }
 257                         else if (*i == ']')
 258                         {
 259                                 // End array (also an end value delimiter)
 260                                 if (!aparent || pisobject)
 261                                         throw JsonException("Unexpected end array token (']')");
 262
 263                                 if (value)
 264                                         AttachToParentReset(aparent, value, vkey);
 265
 266                                 if (!aparent->parent)
 267                                         return aparent;
 268
 269                                 value = aparent;
 270                                 aparent = aparent->parent;
 271                                 vkey = pvkey;
 272                                 pvkey.clear();
 273                                 pisobject = (aparent->GetType() == RPCObject);
 274                         }
 275                         else
 276                         {
 277                                 // Numbers, false, null, and true fall under this heading.
 278                                 if ((*i == 't') && ((i + 3) < data.end()) && (*(i + 1) == 'r') && (*(i + 2) == 'u') && (*(i + 3) == 'e'))
 279                                 {
 280                                         value = new RPCValue(true);
 281                                         i += 3;
 282                                 }
 283                                 else if ((*i == 'f') && ((i + 4) < data.end()) && (*(i + 1) == 'a') && (*(i + 2) == 'l') && (*(i + 3) == 's') && (*(i + 4) == 'e'))
 284                                 {
 285                                         value = new RPCValue(false);
 286                                         i += 4;
 287                                 }
 288                                 else if ((*i == 'n') && ((i + 3) < data.end()) && (*(i + 1) == 'u') && (*(i + 2) == 'l') && (*(i + 3) == 'l'))
 289                                 {
 290                                         value = new RPCValue();
 291                                         i += 3;
 292                                 }
 293                                 else if ((*i == '-') || (*i == '+') || (*i == '.') || ((*i >= '0') && (*i <= '9')))
 294                                 {
 295                                         std::string ds = std::string(i, data.end());
 296                                         char *eds = NULL;
 297
 298                                         errno = 0;
 299                                         double v = strtod(ds.c_str(), &eds);
 300
 301                                         if (errno != 0)
 302                                                 throw JsonException("Error parsing numeric value");
 303
 304                                         value = new RPCValue(v);
 305
 306                                         i += eds - ds.c_str() - 1;
 307                                 }
 308                                 else
 309                                         throw JsonException("Unknown data in value portion");
 310                         }
 311                 }
 312
 313                 if (instring)
 314                         throw JsonException("Unterminated string");
 315
 316                 if (aparent && pisobject)
 317                         throw JsonException("Unterminated object");
 318                 else if (aparent && !pisobject)
 319                         throw JsonException("Unterminated array");
 320
 321                 if (value)
 322                         return value;
 323                 else
 324                         throw JsonException("No JSON data found");
 325         }
 326
 327         void JSONSerialize(RPCValue *value, std::stringstream &re)
 328         {
 329                 int ac;
 330                 switch (value->GetType())
 331                 {
 332                         case RPCNull:
 333                                 re << "null";
 334                                 break;
 335                         case RPCBoolean:
 336                                 re << ((value->GetBool()) ? "true" : "false");
 337                                 break;
 338                         case RPCInteger:
 339                                 re << value->GetInt();
 340                                 break;
 341                         case RPCString:
 342                                 re << "\"" << value->GetString() << "\"";
 343                                 break;
 344                         case RPCArray:
 345                                 re << "[";
 346                                 ac = value->ArraySize();
 347                                 for (int i = 0; i < ac; i++)
 348                                 {
 349                                         this->JSONSerialize(value->GetArray(i), re);
 350                                         if (i != (ac - 1))
 351                                                 re << ",";
 352                                 }
 353                                 re << "]";
 354                                 break;
 355                         case RPCObject:
 356                                 re << "{";
 357                                 std::pair<RPCObjectContainer::iterator,RPCObjectContainer::iterator> its = value->GetObjectIterator();
 358                                 while (its.first != its.second)
 359                                 {
 360                                         re << "\"" << its.first->first << "\":";
 361                                         this->JSONSerialize(its.first->second, re);
 362                                         if (++its.first != its.second)
 363                                                 re << ",";
 364                                 }
 365                                 re << "}";
 366                                 break;
 367                 }
 368         }
 369 };
 370
 371 MODULE_INIT(ModuleRpcJson)