src/modules/extra/m_ziplink.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 <zlib.h>
  16 #include "transport.h"
  17 #include <iostream>
  18
  19 /* $ModDesc: Provides zlib link support for servers */
  20 /* $LinkerFlags: -lz */
  21 /* $ModDep: transport.h */
  22
  23 /*
  24  * ZLIB_BEST_COMPRESSION (9) is used for all sending of data with
  25  * a flush after each chunk. A frame may contain multiple lines
  26  * and should be treated as raw binary data.
  27  */
  28
  29 /* Status of a connection */
  30 enum izip_status { IZIP_CLOSED = 0, IZIP_OPEN };
  31
  32 /** Represents an zipped connections extra data
  33  */
  34 class izip_session : public classbase
  35 {
  36  public:
  37         z_stream c_stream;      /* compression stream */
  38         z_stream d_stream;      /* uncompress stream */
  39         izip_status status;     /* Connection status */
  40         std::string outbuf;     /* Holds output buffer (compressed) */
  41         std::string inbuf;      /* Holds input buffer (compressed) */
  42 };
  43
  44 class ModuleZLib : public Module
  45 {
  46         izip_session* sessions;
  47
  48         /* Used for stats z extensions */
  49         float total_out_compressed;
  50         float total_in_compressed;
  51         float total_out_uncompressed;
  52         float total_in_uncompressed;
  53
  54         /* Used for reading data from the wire and compressing data to. */
  55         char *net_buffer;
  56         unsigned int net_buffer_size;
  57  public:
  58
  59         ModuleZLib(InspIRCd* Me)
  60                 : Module(Me)
  61         {
  62                 ServerInstance->Modules->PublishInterface("BufferedSocketHook", this);
  63
  64                 sessions = new izip_session[ServerInstance->SE->GetMaxFds()];
  65                 for (int i = 0; i < ServerInstance->SE->GetMaxFds(); i++)
  66                         sessions[i].status = IZIP_CLOSED;
  67
  68                 total_out_compressed = total_in_compressed = 0;
  69                 total_out_uncompressed = total_in_uncompressed = 0;
  70                 Implementation eventlist[] = { I_OnRawSocketConnect, I_OnRawSocketAccept, I_OnRawSocketClose, I_OnRawSocketRead, I_OnRawSocketWrite, I_OnStats, I_OnRequest };
  71                 ServerInstance->Modules->Attach(eventlist, this, 7);
  72
  73                 // Allocate a buffer which is used for reading and writing data
  74                 net_buffer_size = ServerInstance->Config->NetBufferSize;
  75                 net_buffer = new char[net_buffer_size];
  76         }
  77
  78         virtual ~ModuleZLib()
  79         {
  80                 ServerInstance->Modules->UnpublishInterface("BufferedSocketHook", this);
  81                 delete[] sessions;
  82                 delete[] net_buffer;
  83         }
  84
  85         virtual Version GetVersion()
  86         {
  87                 return Version("$Id$", VF_VENDOR, API_VERSION);
  88         }
  89
  90
  91         /* Handle BufferedSocketHook API requests */
  92         virtual const char* OnRequest(Request* request)
  93         {
  94                 ISHRequest* ISR = (ISHRequest*)request;
  95                 if (strcmp("IS_NAME", request->GetId()) == 0)
  96                 {
  97                         /* Return name */
  98                         return "zip";
  99                 }
 100                 else if (strcmp("IS_HOOK", request->GetId()) == 0)
 101                 {
 102                         /* Attach to an inspsocket */
 103                         const char* ret = "OK";
 104                         try
 105                         {
 106                                 ret = ISR->Sock->AddIOHook((Module*)this) ? "OK" : NULL;
 107                         }
 108                         catch (ModuleException& e)
 109                         {
 110                                 return NULL;
 111                         }
 112                         return ret;
 113                 }
 114                 else if (strcmp("IS_UNHOOK", request->GetId()) == 0)
 115                 {
 116                         /* Detach from an inspsocket */
 117                         return ISR->Sock->DelIOHook() ? "OK" : NULL;
 118                 }
 119                 else if (strcmp("IS_HSDONE", request->GetId()) == 0)
 120                 {
 121                         /* Check for completion of handshake
 122                          * (actually, this module doesnt handshake)
 123                          */
 124                         return "OK";
 125                 }
 126                 else if (strcmp("IS_ATTACH", request->GetId()) == 0)
 127                 {
 128                         /* Attach certificate data to the inspsocket
 129                          * (this module doesnt do that, either)
 130                          */
 131                         return NULL;
 132                 }
 133                 return NULL;
 134         }
 135
 136         /* Handle stats z (misc stats) */
 137         virtual int OnStats(char symbol, User* user, string_list &results)
 138         {
 139                 if (symbol == 'z')
 140                 {
 141                         std::string sn = ServerInstance->Config->ServerName;
 142
 143                         /* Yeah yeah, i know, floats are ew.
 144                          * We used them here because we'd be casting to float anyway to do this maths,
 145                          * and also only floating point numbers can deal with the pretty large numbers
 146                          * involved in the total throughput of a server over a large period of time.
 147                          * (we dont count 64 bit ints because not all systems have 64 bit ints, and floats
 148                          * can still hold more.
 149                          */
 150                         float outbound_r = (total_out_compressed / (total_out_uncompressed + 0.001)) * 100;
 151                         float inbound_r = (total_in_compressed / (total_in_uncompressed + 0.001)) * 100;
 152
 153                         float total_compressed = total_in_compressed + total_out_compressed;
 154                         float total_uncompressed = total_in_uncompressed + total_out_uncompressed;
 155
 156                         float total_r = (total_compressed / (total_uncompressed + 0.001)) * 100;
 157
 158                         char outbound_ratio[MAXBUF], inbound_ratio[MAXBUF], combined_ratio[MAXBUF];
 159
 160                         sprintf(outbound_ratio, "%3.2f%%", outbound_r);
 161                         sprintf(inbound_ratio, "%3.2f%%", inbound_r);
 162                         sprintf(combined_ratio, "%3.2f%%", total_r);
 163
 164                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS outbound_compressed   = "+ConvToStr(total_out_compressed));
 165                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS inbound_compressed    = "+ConvToStr(total_in_compressed));
 166                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS outbound_uncompressed = "+ConvToStr(total_out_uncompressed));
 167                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS inbound_uncompressed  = "+ConvToStr(total_in_uncompressed));
 168                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS percentage_of_original_outbound_traffic        = "+outbound_ratio);
 169                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS percentage_of_orignal_inbound_traffic         = "+inbound_ratio);
 170                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS total_size_of_original_traffic        = "+combined_ratio);
 171                         return 0;
 172                 }
 173
 174                 return 0;
 175         }
 176
 177         virtual void OnRawSocketConnect(int fd)
 178         {
 179                 if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
 180                         return;
 181
 182                 izip_session* session = &sessions[fd];
 183
 184                 /* Just in case... */
 185                 session->outbuf.clear();
 186
 187                 session->c_stream.zalloc = (alloc_func)0;
 188                 session->c_stream.zfree = (free_func)0;
 189                 session->c_stream.opaque = (voidpf)0;
 190
 191                 session->d_stream.zalloc = (alloc_func)0;
 192                 session->d_stream.zfree = (free_func)0;
 193                 session->d_stream.opaque = (voidpf)0;
 194
 195                 /* If we cant call this, well, we're boned. */
 196                 if (inflateInit(&session->d_stream) != Z_OK)
 197                 {
 198                         session->status = IZIP_CLOSED;
 199                         return;
 200                 }
 201
 202                 /* Same here */
 203                 if (deflateInit(&session->c_stream, Z_BEST_COMPRESSION) != Z_OK)
 204                 {
 205                         inflateEnd(&session->d_stream);
 206                         session->status = IZIP_CLOSED;
 207                         return;
 208                 }
 209
 210                 /* Just in case, do this last */
 211                 session->status = IZIP_OPEN;
 212         }
 213
 214         virtual void OnRawSocketAccept(int fd, const std::string &ip, int localport)
 215         {
 216                 /* Nothing special needs doing here compared to connect() */
 217                 OnRawSocketConnect(fd);
 218         }
 219
 220         virtual void OnRawSocketClose(int fd)
 221         {
 222                 CloseSession(&sessions[fd]);
 223         }
 224
 225         virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
 226         {
 227                 /* Find the sockets session */
 228                 izip_session* session = &sessions[fd];
 229
 230                 if (session->status == IZIP_CLOSED)
 231                         return 0;
 232
 233                 if (session->inbuf.length())
 234                 {
 235                         /* Our input buffer is filling up. This is *BAD*.
 236                          * We can't return more data than fits into buffer
 237                          * (count bytes), so we will generate another read
 238                          * event on purpose by *NOT* reading from 'fd' at all
 239                          * for now.
 240                          */
 241                         readresult = 0;
 242                 }
 243                 else
 244                 {
 245                         /* Read read_buffer_size bytes at a time to the buffer (usually 2.5k) */
 246                         readresult = read(fd, net_buffer, net_buffer_size);
 247
 248                         total_in_compressed += readresult;
 249
 250                         /* Copy the compressed data into our input buffer */
 251                         session->inbuf.append(net_buffer, readresult);
 252                 }
 253
 254                 size_t in_len = session->inbuf.length();
 255
 256                 /* Do we have anything to do? */
 257                 if (in_len <= 0)
 258                         return 0;
 259
 260                 /* Prepare decompression */
 261                 session->d_stream.next_in = (Bytef *)session->inbuf.c_str();
 262                 session->d_stream.avail_in = in_len;
 263
 264                 session->d_stream.next_out = (Bytef*)buffer;
 265                 /* Last byte is reserved for NULL terminating that beast */
 266                 session->d_stream.avail_out = count - 1;
 267
 268                 /* Z_SYNC_FLUSH: Do as much as possible */
 269                 int ret = inflate(&session->d_stream, Z_SYNC_FLUSH);
 270                 /* TODO CloseStream() in here at random places */
 271                 switch (ret)
 272                 {
 273                         case Z_NEED_DICT:
 274                         case Z_STREAM_ERROR:
 275                                 /* This is one of the 'not supposed to happen' things.
 276                                  * Memory corruption, anyone?
 277                                  */
 278                                 Error(session, "General Error. This is not supposed to happen :/");
 279                                 break;
 280                         case Z_DATA_ERROR:
 281                                 Error(session, "Decompression failed, malformed data");
 282                                 break;
 283                         case Z_MEM_ERROR:
 284                                 Error(session, "Out of memory");
 285                                 break;
 286                         case Z_BUF_ERROR:
 287                                 /* This one is non-fatal, buffer is just full
 288                                  * (can't happen here).
 289                                  */
 290                                 Error(session, "Internal error. This is not supposed to happen.");
 291                                 break;
 292                         case Z_STREAM_END:
 293                                 /* This module *never* generates these :/ */
 294                                 Error(session, "End-of-stream marker received");
 295                                 break;
 296                         case Z_OK:
 297                                 break;
 298                         default:
 299                                 /* NO WAI! This can't happen. All errors are handled above. */
 300                                 Error(session, "Unknown error");
 301                                 break;
 302                 }
 303                 if (ret != Z_OK)
 304                 {
 305                         readresult = 0;
 306                         return 0;
 307                 }
 308
 309                 /* Update the inbut buffer */
 310                 unsigned int input_compressed = in_len - session->d_stream.avail_in;
 311                 session->inbuf = session->inbuf.substr(input_compressed);
 312
 313                 /* Update counters (Old size - new size) */
 314                 unsigned int uncompressed_length = (count - 1) - session->d_stream.avail_out;
 315                 total_in_uncompressed += uncompressed_length;
 316
 317                 /* Null-terminate the buffer -- this doesnt harm binary data */
 318                 buffer[uncompressed_length] = 0;
 319
 320                 /* Set the read size to the correct total size */
 321                 readresult = uncompressed_length;
 322
 323                 return 1;
 324         }
 325
 326         virtual int OnRawSocketWrite(int fd, const char* buffer, int count)
 327         {
 328                 izip_session* session = &sessions[fd];
 329
 330                 if (!count)     /* Nothing to do! */
 331                         return 0;
 332
 333                 if(session->status != IZIP_OPEN)
 334                         /* Seriously, wtf? */
 335                         return 0;
 336
 337                 int ret;
 338
 339                 /* This loop is really only supposed to run once, but in case 'compr'
 340                  * is filled up somehow we are prepared to handle this situation.
 341                  */
 342                 unsigned int offset = 0;
 343                 do
 344                 {
 345                         /* Prepare compression */
 346                         session->c_stream.next_in = (Bytef*)buffer + offset;
 347                         session->c_stream.avail_in = count - offset;
 348
 349                         session->c_stream.next_out = (Bytef*)net_buffer;
 350                         session->c_stream.avail_out = net_buffer_size;
 351
 352                         /* Compress the text */
 353                         ret = deflate(&session->c_stream, Z_SYNC_FLUSH);
 354                         /* TODO CloseStream() in here at random places */
 355                         switch (ret)
 356                         {
 357                                 case Z_OK:
 358                                         break;
 359                                 case Z_BUF_ERROR:
 360                                         /* This one is non-fatal, buffer is just full
 361                                          * (can't happen here).
 362                                          */
 363                                         Error(session, "Internal error. This is not supposed to happen.");
 364                                         break;
 365                                 case Z_STREAM_ERROR:
 366                                         /* This is one of the 'not supposed to happen' things.
 367                                          * Memory corruption, anyone?
 368                                          */
 369                                         Error(session, "General Error. This is also not supposed to happen.");
 370                                         break;
 371                                 default:
 372                                         Error(session, "Unknown error");
 373                                         break;
 374                         }
 375
 376                         if (ret != Z_OK)
 377                                 return 0;
 378
 379                         /* Space before - space after stuff was added to this */
 380                         unsigned int compressed = net_buffer_size - session->c_stream.avail_out;
 381                         unsigned int uncompressed = count - session->c_stream.avail_in;
 382
 383                         /* Make it skip the data which was compressed already */
 384                         offset += uncompressed;
 385
 386                         /* Update stats */
 387                         total_out_uncompressed += uncompressed;
 388                         total_out_compressed += compressed;
 389
 390                         /* Add compressed to the output buffer */
 391                         session->outbuf.append((const char*)net_buffer, compressed);
 392                 } while (session->c_stream.avail_in != 0);
 393
 394                 /* Lets see how much we can send out */
 395                 ret = write(fd, session->outbuf.data(), session->outbuf.length());
 396
 397                 /* Check for errors, and advance the buffer if any was sent */
 398                 if (ret > 0)
 399                         session->outbuf = session->outbuf.substr(ret);
 400                 else if (ret < 1)
 401                 {
 402                         if (errno == EAGAIN)
 403                                 return 0;
 404                         else
 405                         {
 406                                 session->outbuf.clear();
 407                                 return 0;
 408                         }
 409                 }
 410
 411                 /* ALL LIES the lot of it, we havent really written
 412                  * this amount, but the layer above doesnt need to know.
 413                  */
 414                 return count;
 415         }
 416
 417         void Error(izip_session* session, const std::string &text)
 418         {
 419                 ServerInstance->SNO->WriteToSnoMask('l', "ziplink error: " + text);
 420         }
 421
 422         void CloseSession(izip_session* session)
 423         {
 424                 if (session->status == IZIP_OPEN)
 425                 {
 426                         session->status = IZIP_CLOSED;
 427                         session->outbuf.clear();
 428                         inflateEnd(&session->d_stream);
 429                         deflateEnd(&session->c_stream);
 430                 }
 431         }
 432
 433 };
 434
 435 MODULE_INIT(ModuleZLib)
 436