src/modules/m_rpc_json.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2009 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/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 "httpd.h"
  16 #include "rpc.h"
  17 #include <exception>
  18
  19 /* $ModDesc: Encode and decode JSON-RPC requests for modules */
  20 /* $ModDep: httpd.h rpc.h */
  21
  22 class JsonException : public std::exception
  23 {
  24  private:
  25         std::string _what;
  26  public:
  27         JsonException(const std::string &swhat)
  28                 : _what(swhat)
  29         {
  30         }
  31
  32         virtual ~JsonException() throw() { }
  33
  34         virtual const char *what() const throw()
  35         {
  36                 return _what.c_str();
  37         }
  38 };
  39
  40 class ModuleRpcJson : public Module
  41 {
  42  private:
  43
  44  public:
  45         ModuleRpcJson(InspIRCd *Me) : Module(Me)
  46         {
  47                 ServerInstance->Modules->PublishInterface("RPC", this);
  48                 Implementation eventlist[] = { I_OnEvent };
  49                 ServerInstance->Modules->Attach(eventlist, this, 1);
  50         }
  51
  52         virtual ~ModuleRpcJson()
  53         {
  54                 ServerInstance->Modules->UnpublishInterface("RPC", this);
  55         }
  56
  57         virtual Version GetVersion()
  58         {
  59                 return Version("Encode and decode JSON-RPC requests for modules", VF_SERVICEPROVIDER | VF_VENDOR, API_VERSION);
  60         }
  61
  62
  63         virtual void OnEvent(Event *event)
  64         {
  65                 if (event->GetEventID() == "httpd_url")
  66                 {
  67                         HTTPRequest *req = (HTTPRequest*) event->GetData();
  68
  69                         if ((req->GetURI() == "/rpc/json") || (req->GetURI() == "/rpc/json/"))
  70                         {
  71                                 std::stringstream data;
  72
  73                                 RPCValue *reqobj = NULL;
  74
  75                                 try
  76                                 {
  77                                         reqobj = this->JSONParse(req->GetPostData());
  78
  79                                         if (!reqobj || (reqobj->GetType() != RPCObject))
  80                                                 throw JsonException("RPC requests must be in the form of a single object");
  81
  82                                         RPCValue *method = reqobj->GetObject("method");
  83                                         if (!method || method->GetType() != RPCString)
  84                                                 throw JsonException("RPC requests must have a 'method' string field");
  85
  86                                         RPCValue *params = reqobj->GetObject("params");
  87                                         if (!params || params->GetType() != RPCArray)
  88                                                 throw JsonException("RPC requests must have a 'params' array field");
  89
  90                                         RPCRequest modreq("json", method->GetString(), params);
  91                                         Event mev((char*) &modreq, this, "RPCMethod");
  92                                         mev.Send(ServerInstance);
  93
  94                                         if (!modreq.claimed)
  95                                                 throw JsonException("Unrecognized method");
  96
  97                                         if (!modreq.error.empty())
  98                                         {
  99                                                 data << "{\"result\":null,\"error\":\"" << modreq.error << "\"";
 100                                         }
 101                                         else
 102                                         {
 103                                                 data << "{\"result\":";
 104                                                 this->JSONSerialize(modreq.result, data);
 105                                                 data << ",\"error\":null";
 106                                         }
 107
 108                                         if (reqobj->GetObject("id"))
 109                                         {
 110                                                 data << ",\"id\":";
 111                                                 this->JSONSerialize(reqobj->GetObject("id"), data);
 112                                         }
 113                                         data << "}";
 114
 115                                         delete reqobj;
 116                                         reqobj = NULL;
 117                                 }
 118                                 catch (std::exception &e)
 119                                 {
 120                                         if (reqobj)
 121                                                 delete reqobj;
 122                                         data << "{\"result\":null,\"error\":\"" << e.what() << "\"}";
 123                                 }
 124
 125                                 HTTPDocument response(req->sock, &data, 200);
 126                                 response.headers.SetHeader("X-Powered-By", "m_rpc_json.so");
 127                                 response.headers.SetHeader("Content-Type", "application/json");
 128                                 response.headers.SetHeader("Connection", "Keep-Alive");
 129
 130                                 Request rreq((char*) &response, (Module*) this, event->GetSource());
 131                                 rreq.Send();
 132                         }
 133                 }
 134         }
 135
 136         void AttachToParent(RPCValue *parent, RPCValue *child, const std::string &key = "")
 137         {
 138                 if (!parent || !child)
 139                         return;
 140
 141                 if (parent->GetType() == RPCArray)
 142                         parent->ArrayAdd(child);
 143                 else if (parent->GetType() == RPCObject)
 144                         parent->ObjectAdd(key, child);
 145                 else
 146                         throw JsonException("Cannot add a value to a non-container");
 147         }
 148
 149         void AttachToParentReset(RPCValue *parent, RPCValue *&child, std::string &key)
 150         {
 151                 AttachToParent(parent, child, key);
 152                 child = NULL;
 153                 key.clear();
 154         }
 155
 156         RPCValue *JSONParse(const std::string &data)
 157         {
 158                 bool pisobject = false;
 159                 bool instring = false;
 160                 std::string stmp;
 161                 std::string vkey;
 162                 std::string pvkey;
 163                 RPCValue *aparent = NULL;
 164                 RPCValue *value = NULL;
 165
 166                 for (std::string::const_iterator i = data.begin(); i != data.end(); i++)
 167                 {
 168                         if (instring)
 169                         {
 170                                 // TODO escape sequences
 171                                 if (*i == '"')
 172                                 {
 173                                         instring = false;
 174
 175                                         if (pisobject && vkey.empty())
 176                                                 vkey = stmp;
 177                                         else
 178                                                 value = new RPCValue(stmp);
 179
 180                                         stmp.clear();
 181                                 }
 182                                 else
 183                                         stmp += *i;
 184
 185                                 continue;
 186                         }
 187
 188                         if ((*i == ' ') || (*i == '\t') || (*i == '\r') || (*i == '\n'))
 189                                 continue;
 190
 191                         if (*i == '{')
 192                         {
 193                                 // Begin object
 194                                 if ((value) || (pisobject && vkey.empty()))
 195                                         throw JsonException("Unexpected begin object token ('{')");
 196
 197                                 RPCValue *nobj = new RPCValue(RPCObject, aparent);
 198                                 aparent = nobj;
 199                                 pvkey = vkey;
 200                                 vkey.clear();
 201                                 pisobject = true;
 202                         }
 203                         else if (*i == '}')
 204                         {
 205                                 // End object
 206                                 if ((!aparent) || (!pisobject) || (!vkey.empty() && !value))
 207                                         throw JsonException("Unexpected end object token ('}')");
 208
 209                                 // End value
 210                                 if (value)
 211                                         AttachToParentReset(aparent, value, vkey);
 212
 213                                 if (!aparent->parent)
 214                                         return aparent;
 215
 216                                 value = aparent;
 217                                 aparent = aparent->parent;
 218                                 vkey = pvkey;
 219                                 pvkey.clear();
 220                                 pisobject = (aparent->GetType() == RPCObject);
 221                         }
 222                         else if (*i == '"')
 223                         {
 224                                 // Begin string
 225                                 if (value)
 226                                         throw JsonException("Unexpected begin string token ('\"')");
 227
 228                                 instring = true;
 229                         }
 230                         else if (*i == ':')
 231                         {
 232                                 if ((!aparent) || (!pisobject) || (vkey.empty()) || (value))
 233                                         throw JsonException("Unexpected object value token (':')");
 234                         }
 235                         else if (*i == ',')
 236                         {
 237                                 if ((!aparent) || (!value) || ((pisobject) && (vkey.empty())))
 238                                         throw JsonException("Unexpected value seperator token (',')");
 239
 240                                 AttachToParentReset(aparent, value, vkey);
 241                         }
 242                         else if (*i == '[')
 243                         {
 244                                 // Begin array
 245                                 if ((value) || (pisobject && vkey.empty()))
 246                                         throw JsonException("Unexpected begin array token ('[')");
 247
 248                                 RPCValue *nar = new RPCValue(RPCArray, aparent);
 249                                 aparent = nar;
 250                                 pvkey = vkey;
 251                                 vkey.clear();
 252                                 pisobject = false;
 253                         }
 254                         else if (*i == ']')
 255                         {
 256                                 // End array (also an end value delimiter)
 257                                 if (!aparent || pisobject)
 258                                         throw JsonException("Unexpected end array token (']')");
 259
 260                                 if (value)
 261                                         AttachToParentReset(aparent, value, vkey);
 262
 263                                 if (!aparent->parent)
 264                                         return aparent;
 265
 266                                 value = aparent;
 267                                 aparent = aparent->parent;
 268                                 vkey = pvkey;
 269                                 pvkey.clear();
 270                                 pisobject = (aparent->GetType() == RPCObject);
 271                         }
 272                         else
 273                         {
 274                                 // Numbers, false, null, and true fall under this heading.
 275                                 if ((*i == 't') && ((i + 3) < data.end()) && (*(i + 1) == 'r') && (*(i + 2) == 'u') && (*(i + 3) == 'e'))
 276                                 {
 277                                         value = new RPCValue(true);
 278                                         i += 3;
 279                                 }
 280                                 else if ((*i == 'f') && ((i + 4) < data.end()) && (*(i + 1) == 'a') && (*(i + 2) == 'l') && (*(i + 3) == 's') && (*(i + 4) == 'e'))
 281                                 {
 282                                         value = new RPCValue(false);
 283                                         i += 4;
 284                                 }
 285                                 else if ((*i == 'n') && ((i + 3) < data.end()) && (*(i + 1) == 'u') && (*(i + 2) == 'l') && (*(i + 3) == 'l'))
 286                                 {
 287                                         value = new RPCValue();
 288                                         i += 3;
 289                                 }
 290                                 else if ((*i == '-') || (*i == '+') || (*i == '.') || ((*i >= '0') && (*i <= '9')))
 291                                 {
 292                                         std::string ds = std::string(i, data.end());
 293                                         char *eds = NULL;
 294
 295                                         errno = 0;
 296                                         double v = strtod(ds.c_str(), &eds);
 297
 298                                         if (errno != 0)
 299                                                 throw JsonException("Error parsing numeric value");
 300
 301                                         value = new RPCValue(v);
 302
 303                                         i += eds - ds.c_str() - 1;
 304                                 }
 305                                 else
 306                                         throw JsonException("Unknown data in value portion");
 307                         }
 308                 }
 309
 310                 if (instring)
 311                         throw JsonException("Unterminated string");
 312
 313                 if (aparent && pisobject)
 314                         throw JsonException("Unterminated object");
 315                 else if (aparent && !pisobject)
 316                         throw JsonException("Unterminated array");
 317
 318                 if (value)
 319                         return value;
 320                 else
 321                         throw JsonException("No JSON data found");
 322         }
 323
 324         void JSONSerialize(RPCValue *value, std::stringstream &re)
 325         {
 326                 int ac;
 327                 switch (value->GetType())
 328                 {
 329                         case RPCNull:
 330                                 re << "null";
 331                                 break;
 332                         case RPCBoolean:
 333                                 re << ((value->GetBool()) ? "true" : "false");
 334                                 break;
 335                         case RPCInteger:
 336                                 re << value->GetInt();
 337                                 break;
 338                         case RPCString:
 339                                 re << "\"" << value->GetString() << "\"";
 340                                 break;
 341                         case RPCArray:
 342                                 re << "[";
 343                                 ac = value->ArraySize();
 344                                 for (int i = 0; i < ac; i++)
 345                                 {
 346                                         this->JSONSerialize(value->GetArray(i), re);
 347                                         if (i != (ac - 1))
 348                                                 re << ",";
 349                                 }
 350                                 re << "]";
 351                                 break;
 352                         case RPCObject:
 353                                 re << "{";
 354                                 std::pair<RPCObjectContainer::iterator,RPCObjectContainer::iterator> its = value->GetObjectIterator();
 355                                 while (its.first != its.second)
 356                                 {
 357                                         re << "\"" << its.first->first << "\":";
 358                                         this->JSONSerialize(its.first->second, re);
 359                                         if (++its.first != its.second)
 360                                                 re << ",";
 361                                 }
 362                                 re << "}";
 363                                 break;
 364                 }
 365         }
 366 };
 367
 368 MODULE_INIT(ModuleRpcJson)