src/modules/extra/m_ziplink.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd is copyright (C) 2002-2006 ChatSpike-Dev.
   6  *                       E-mail:
   7  *                <brain@chatspike.net>
   8  *                <Craig@chatspike.net>
   9  *
  10  * Written by Craig Edwards, Craig McLure, and others.
  11  * This program is free but copyrighted software; see
  12  *            the file COPYING for details.
  13  *
  14  * ---------------------------------------------------
  15  */
  16
  17 #include <string>
  18 #include <vector>
  19
  20 #include "zlib.h"
  21
  22 #include "inspircd_config.h"
  23 #include "configreader.h"
  24 #include "users.h"
  25 #include "channels.h"
  26 #include "modules.h"
  27
  28 #include "socket.h"
  29 #include "hashcomp.h"
  30 #include "inspircd.h"
  31
  32 #include "transport.h"
  33
  34 /* $ModDesc: Provides zlib link support for servers */
  35 /* $LinkerFlags: -lz */
  36 /* $ModDep: transport.h */
  37
  38 /*
  39  * Compressed data is transmitted across the link in the following format:
  40  *
  41  *   0   1   2   3   4 ... n
  42  * +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
  43  * |       n       |              Z0 -> Zn                         |
  44  * +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
  45  *
  46  * Where: n is the size of a frame, in network byte order, 4 bytes.
  47  * Z0 through Zn are Zlib compressed data, n bytes in length.
  48  *
  49  * If the module fails to read the entire frame, then it will buffer
  50  * the portion of the last frame it received, then attempt to read
  51  * the next part of the frame next time a write notification arrives.
  52  *
  53  * ZLIB_BEST_COMPRESSION (9) is used for all sending of data with
  54  * a flush after each frame. A frame may contain multiple lines
  55  * and should be treated as raw binary data.
  56  *
  57  */
  58
  59 /* Status of a connection */
  60 enum izip_status { IZIP_OPEN, IZIP_CLOSED };
  61
  62 /* Maximum transfer size per read operation */
  63 const unsigned int CHUNK = 128 * 1024;
  64
  65 /* This class manages a compressed chunk of data preceeded by
  66  * a length count.
  67  *
  68  * It can handle having multiple chunks of data in the buffer
  69  * at any time.
  70  */
  71 class CountedBuffer : public classbase
  72 {
  73         std::string buffer;             /* Current buffer contents */
  74         unsigned int amount_expected;   /* Amount of data expected */
  75  public:
  76         CountedBuffer()
  77         {
  78                 amount_expected = 0;
  79         }
  80
  81         /** Adds arbitrary compressed data to the buffer.
  82          * - Binsry safe, of course.
  83          */
  84         void AddData(unsigned char* data, int data_length)
  85         {
  86                 buffer.append((const char*)data, data_length);
  87                 this->NextFrameSize();
  88         }
  89
  90         /** Works out the size of the next compressed frame
  91          */
  92         void NextFrameSize()
  93         {
  94                 if ((!amount_expected) && (buffer.length() >= 4))
  95                 {
  96                         /* We have enough to read an int -
  97                          * Yes, this is safe, but its ugly. Give me
  98                          * a nicer way to read 4 bytes from a binary
  99                          * stream, and push them into a 32 bit int,
 100                          * and i'll consider replacing this.
 101                          */
 102                         amount_expected = ntohl((buffer[3] << 24) | (buffer[2] << 16) | (buffer[1] << 8) | buffer[0]);
 103                         buffer = buffer.substr(4);
 104                 }
 105         }
 106
 107         /** Gets the next frame and returns its size, or returns
 108          * zero if there isnt one available yet.
 109          * A frame can contain multiple plaintext lines.
 110          * - Binary safe.
 111          */
 112         int GetFrame(unsigned char* frame, int maxsize)
 113         {
 114                 if (amount_expected)
 115                 {
 116                         /* We know how much we're expecting...
 117                          * Do we have enough yet?
 118                          */
 119                         if (buffer.length() >= amount_expected)
 120                         {
 121                                 int j = 0;
 122                                 for (unsigned int i = 0; i < amount_expected; i++, j++)
 123                                         frame[i] = buffer[i];
 124
 125                                 buffer = buffer.substr(j);
 126                                 amount_expected = 0;
 127                                 NextFrameSize();
 128                                 return j;
 129                         }
 130                 }
 131                 /* Not enough for a frame yet, COME AGAIN! */
 132                 return 0;
 133         }
 134 };
 135
 136 /** Represents an zipped connections extra data
 137  */
 138 class izip_session : public classbase
 139 {
 140  public:
 141         z_stream c_stream;      /* compression stream */
 142         z_stream d_stream;      /* decompress stream */
 143         izip_status status;     /* Connection status */
 144         int fd;                 /* File descriptor */
 145         CountedBuffer* inbuf;   /* Holds input buffer */
 146         std::string outbuf;     /* Holds output buffer */
 147 };
 148
 149 class ModuleZLib : public Module
 150 {
 151         izip_session sessions[MAX_DESCRIPTORS];
 152
 153         /* Used for stats z extensions */
 154         float total_out_compressed;
 155         float total_in_compressed;
 156         float total_out_uncompressed;
 157         float total_in_uncompressed;
 158
 159  public:
 160
 161         ModuleZLib(InspIRCd* Me)
 162                 : Module::Module(Me)
 163         {
 164                 ServerInstance->PublishInterface("InspSocketHook", this);
 165
 166                 total_out_compressed = total_in_compressed = 0;
 167                 total_out_uncompressed = total_out_uncompressed = 0;
 168         }
 169
 170         virtual ~ModuleZLib()
 171         {
 172                 ServerInstance->UnpublishInterface("InspSocketHook", this);
 173         }
 174
 175         virtual Version GetVersion()
 176         {
 177                 return Version(1, 1, 0, 0, VF_VENDOR, API_VERSION);
 178         }
 179
 180         void Implements(char* List)
 181         {
 182                 List[I_OnRawSocketConnect] = List[I_OnRawSocketAccept] = List[I_OnRawSocketClose] = List[I_OnRawSocketRead] = List[I_OnRawSocketWrite] = 1;
 183                 List[I_OnStats] = List[I_OnRequest] = 1;
 184         }
 185
 186         /* Handle InspSocketHook API requests */
 187         virtual char* OnRequest(Request* request)
 188         {
 189                 ISHRequest* ISR = (ISHRequest*)request;
 190                 if (strcmp("IS_NAME", request->GetId()) == 0)
 191                 {
 192                         /* Return name */
 193                         return "zip";
 194                 }
 195                 else if (strcmp("IS_HOOK", request->GetId()) == 0)
 196                 {
 197                         /* Attach to an inspsocket */
 198                         char* ret = "OK";
 199                         try
 200                         {
 201                                 ret = ServerInstance->Config->AddIOHook((Module*)this, (InspSocket*)ISR->Sock) ? (char*)"OK" : NULL;
 202                         }
 203                         catch (ModuleException& e)
 204                         {
 205                                 return NULL;
 206                         }
 207                         return ret;
 208                 }
 209                 else if (strcmp("IS_UNHOOK", request->GetId()) == 0)
 210                 {
 211                         /* Detatch from an inspsocket */
 212                         return ServerInstance->Config->DelIOHook((InspSocket*)ISR->Sock) ? (char*)"OK" : NULL;
 213                 }
 214                 else if (strcmp("IS_HSDONE", request->GetId()) == 0)
 215                 {
 216                         /* Check for completion of handshake
 217                          * (actually, this module doesnt handshake)
 218                          */
 219                         return "OK";
 220                 }
 221                 else if (strcmp("IS_ATTACH", request->GetId()) == 0)
 222                 {
 223                         /* Attach certificate data to the inspsocket
 224                          * (this module doesnt do that, either)
 225                          */
 226                         return NULL;
 227                 }
 228                 return NULL;
 229         }
 230
 231         /* Handle stats z (misc stats) */
 232         virtual int OnStats(char symbol, userrec* user, string_list &results)
 233         {
 234                 if (symbol == 'z')
 235                 {
 236                         std::string sn = ServerInstance->Config->ServerName;
 237
 238                         /* Yeah yeah, i know, floats are ew.
 239                          * We used them here because we'd be casting to float anyway to do this maths,
 240                          * and also only floating point numbers can deal with the pretty large numbers
 241                          * involved in the total throughput of a server over a large period of time.
 242                          * (we dont count 64 bit ints because not all systems have 64 bit ints, and floats
 243                          * can still hold more.
 244                          */
 245                         float outbound_r = 100 - ((total_out_compressed / (total_out_uncompressed + 0.001)) * 100);
 246                         float inbound_r = 100 - ((total_in_compressed / (total_in_uncompressed + 0.001)) * 100);
 247
 248                         float total_compressed = total_in_compressed + total_out_compressed;
 249                         float total_uncompressed = total_in_uncompressed + total_out_uncompressed;
 250
 251                         float total_r = 100 - ((total_compressed / (total_uncompressed + 0.001)) * 100);
 252
 253                         char outbound_ratio[MAXBUF], inbound_ratio[MAXBUF], combined_ratio[MAXBUF];
 254
 255                         sprintf(outbound_ratio, "%3.2f%%", outbound_r);
 256                         sprintf(inbound_ratio, "%3.2f%%", inbound_r);
 257                         sprintf(combined_ratio, "%3.2f%%", total_r);
 258
 259                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS outbound_compressed   = "+ConvToStr(total_out_compressed));
 260                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS inbound_compressed    = "+ConvToStr(total_in_compressed));
 261                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS outbound_uncompressed = "+ConvToStr(total_out_uncompressed));
 262                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS inbound_uncompressed  = "+ConvToStr(total_in_uncompressed));
 263                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS outbound_ratio        = "+outbound_ratio);
 264                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS inbound_ratio         = "+inbound_ratio);
 265                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS combined_ratio        = "+combined_ratio);
 266                         return 0;
 267                 }
 268
 269                 return 0;
 270         }
 271
 272         virtual void OnRawSocketAccept(int fd, const std::string &ip, int localport)
 273         {
 274                 izip_session* session = &sessions[fd];
 275
 276                 /* allocate state and buffers */
 277                 session->fd = fd;
 278                 session->status = IZIP_OPEN;
 279                 session->inbuf = new CountedBuffer();
 280
 281                 session->c_stream.zalloc = (alloc_func)0;
 282                 session->c_stream.zfree = (free_func)0;
 283                 session->c_stream.opaque = (voidpf)0;
 284
 285                 session->d_stream.zalloc = (alloc_func)0;
 286                 session->d_stream.zfree = (free_func)0;
 287                 session->d_stream.opaque = (voidpf)0;
 288         }
 289
 290         virtual void OnRawSocketConnect(int fd)
 291         {
 292                 /* Nothing special needs doing here compared to accept() */
 293                 OnRawSocketAccept(fd, "", 0);
 294         }
 295
 296         virtual void OnRawSocketClose(int fd)
 297         {
 298                 CloseSession(&sessions[fd]);
 299         }
 300
 301         virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
 302         {
 303                 /* Find the sockets session */
 304                 izip_session* session = &sessions[fd];
 305
 306                 if (session->status == IZIP_CLOSED)
 307                         return 0;
 308
 309                 unsigned char compr[CHUNK + 4];
 310                 unsigned int offset = 0;
 311                 unsigned int total_size = 0;
 312
 313                 /* Read CHUNK bytes at a time to the buffer (usually 128k) */
 314                 readresult = read(fd, compr, CHUNK);
 315
 316                 /* Did we get anything? */
 317                 if (readresult > 0)
 318                 {
 319                         /* Add it to the frame queue */
 320                         session->inbuf->AddData(compr, readresult);
 321                         total_in_compressed += readresult;
 322
 323                         /* Parse all completed frames */
 324                         int size = 0;
 325                         while ((size = session->inbuf->GetFrame(compr, CHUNK)) != 0)
 326                         {
 327                                 session->d_stream.next_in  = (Bytef*)compr;
 328                                 session->d_stream.avail_in = 0;
 329                                 session->d_stream.next_out = (Bytef*)(buffer + offset);
 330
 331                                 /* If we cant call this, well, we're boned. */
 332                                 if (inflateInit(&session->d_stream) != Z_OK)
 333                                         return 0;
 334
 335                                 while ((session->d_stream.total_out < count) && (session->d_stream.total_in < (unsigned int)size))
 336                                 {
 337                                         session->d_stream.avail_in = session->d_stream.avail_out = 1;
 338                                         if (inflate(&session->d_stream, Z_NO_FLUSH) == Z_STREAM_END)
 339                                                 break;
 340                                 }
 341
 342                                 /* Stick a fork in me, i'm done */
 343                                 inflateEnd(&session->d_stream);
 344
 345                                 /* Update counters and offsets */
 346                                 total_size += session->d_stream.total_out;
 347                                 total_in_uncompressed += session->d_stream.total_out;
 348                                 offset += session->d_stream.total_out;
 349                         }
 350
 351                         /* Null-terminate the buffer -- this doesnt harm binary data */
 352                         buffer[total_size] = 0;
 353
 354                         /* Set the read size to the correct total size */
 355                         readresult = total_size;
 356
 357                 }
 358                 return (readresult > 0);
 359         }
 360
 361         virtual int OnRawSocketWrite(int fd, const char* buffer, int count)
 362         {
 363                 izip_session* session = &sessions[fd];
 364                 int ocount = count;
 365
 366                 if (!count)     /* Nothing to do! */
 367                         return 0;
 368
 369                 if(session->status != IZIP_OPEN)
 370                 {
 371                         /* Seriously, wtf? */
 372                         CloseSession(session);
 373                         return 0;
 374                 }
 375
 376                 unsigned char compr[CHUNK + 4];
 377
 378                 /* Gentlemen, start your engines! */
 379                 if (deflateInit(&session->c_stream, Z_BEST_COMPRESSION) != Z_OK)
 380                 {
 381                         CloseSession(session);
 382                         return 0;
 383                 }
 384
 385                 /* Set buffer sizes (we reserve 4 bytes at the start of the
 386                  * buffer for the length counters)
 387                  */
 388                 session->c_stream.next_in  = (Bytef*)buffer;
 389                 session->c_stream.next_out = compr + 4;
 390
 391                 /* Compress the text */
 392                 while ((session->c_stream.total_in < (unsigned int)count) && (session->c_stream.total_out < CHUNK))
 393                 {
 394                         session->c_stream.avail_in = session->c_stream.avail_out = 1;
 395                         if (deflate(&session->c_stream, Z_NO_FLUSH) != Z_OK)
 396                         {
 397                                 CloseSession(session);
 398                                 return 0;
 399                         }
 400                 }
 401                 /* Finish the stream */
 402                 for (session->c_stream.avail_out = 1; deflate(&session->c_stream, Z_FINISH) != Z_STREAM_END; session->c_stream.avail_out = 1);
 403                 deflateEnd(&session->c_stream);
 404
 405                 total_out_uncompressed += ocount;
 406                 total_out_compressed += session->c_stream.total_out;
 407
 408                 /** Assemble the frame length onto the frame, in network byte order */
 409                 compr[0] = (session->c_stream.total_out >> 24);
 410                 compr[1] = (session->c_stream.total_out >> 16);
 411                 compr[2] = (session->c_stream.total_out >> 8);
 412                 compr[3] = (session->c_stream.total_out & 0xFF);
 413
 414                 /* Add compressed data plus leading length to the output buffer -
 415                  * Note, we may have incomplete half-sent frames in here.
 416                  */
 417                 session->outbuf.append((const char*)compr, session->c_stream.total_out + 4);
 418
 419                 /* Lets see how much we can send out */
 420                 int ret = write(fd, session->outbuf.data(), session->outbuf.length());
 421
 422                 /* Check for errors, and advance the buffer if any was sent */
 423                 if (ret > 0)
 424                         session->outbuf = session->outbuf.substr(ret);
 425                 else if (ret < 1)
 426                 {
 427                         if (ret == -1)
 428                         {
 429                                 if (errno == EAGAIN)
 430                                         return 0;
 431                                 else
 432                                 {
 433                                         session->outbuf = "";
 434                                         return 0;
 435                                 }
 436                         }
 437                         else
 438                         {
 439                                 session->outbuf = "";
 440                                 return 0;
 441                         }
 442                 }
 443
 444                 /* ALL LIES the lot of it, we havent really written
 445                  * this amount, but the layer above doesnt need to know.
 446                  */
 447                 return ocount;
 448         }
 449
 450         void CloseSession(izip_session* session)
 451         {
 452                 if (session->status = IZIP_OPEN)
 453                 {
 454                         session->status = IZIP_CLOSED;
 455                         session->outbuf = "";
 456                         delete session->inbuf;
 457                 }
 458         }
 459
 460 };
 461
 462 class ModuleZLibFactory : public ModuleFactory
 463 {
 464  public:
 465         ModuleZLibFactory()
 466         {
 467         }
 468
 469         ~ModuleZLibFactory()
 470         {
 471         }
 472
 473         virtual Module * CreateModule(InspIRCd* Me)
 474         {
 475                 return new ModuleZLib(Me);
 476         }
 477 };
 478
 479
 480 extern "C" void * init_module( void )
 481 {
 482         return new ModuleZLibFactory;
 483 }