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         }
 173
 174         virtual Version GetVersion()
 175         {
 176                 return Version(1, 1, 0, 0, VF_VENDOR, API_VERSION);
 177         }
 178
 179         void Implements(char* List)
 180         {
 181                 List[I_OnRawSocketConnect] = List[I_OnRawSocketAccept] = List[I_OnRawSocketClose] = List[I_OnRawSocketRead] = List[I_OnRawSocketWrite] = 1;
 182                 List[I_OnStats] = List[I_OnRequest] = 1;
 183         }
 184
 185         /* Handle InspSocketHook API requests */
 186         virtual char* OnRequest(Request* request)
 187         {
 188                 ISHRequest* ISR = (ISHRequest*)request;
 189                 if (strcmp("IS_NAME", request->GetId()) == 0)
 190                 {
 191                         /* Return name */
 192                         return "zip";
 193                 }
 194                 else if (strcmp("IS_HOOK", request->GetId()) == 0)
 195                 {
 196                         /* Attach to an inspsocket */
 197                         char* ret = "OK";
 198                         try
 199                         {
 200                                 ret = ServerInstance->Config->AddIOHook((Module*)this, (InspSocket*)ISR->Sock) ? (char*)"OK" : NULL;
 201                         }
 202                         catch (ModuleException& e)
 203                         {
 204                                 return NULL;
 205                         }
 206                         return ret;
 207                 }
 208                 else if (strcmp("IS_UNHOOK", request->GetId()) == 0)
 209                 {
 210                         /* Detatch from an inspsocket */
 211                         return ServerInstance->Config->DelIOHook((InspSocket*)ISR->Sock) ? (char*)"OK" : NULL;
 212                 }
 213                 else if (strcmp("IS_HSDONE", request->GetId()) == 0)
 214                 {
 215                         /* Check for completion of handshake
 216                          * (actually, this module doesnt handshake)
 217                          */
 218                         return "OK";
 219                 }
 220                 else if (strcmp("IS_ATTACH", request->GetId()) == 0)
 221                 {
 222                         /* Attach certificate data to the inspsocket
 223                          * (this module doesnt do that, either)
 224                          */
 225                         return NULL;
 226                 }
 227                 return NULL;
 228         }
 229
 230         /* Handle stats z (misc stats) */
 231         virtual int OnStats(char symbol, userrec* user, string_list &results)
 232         {
 233                 if (symbol == 'z')
 234                 {
 235                         std::string sn = ServerInstance->Config->ServerName;
 236
 237                         /* Yeah yeah, i know, floats are ew.
 238                          * We used them here because we'd be casting to float anyway to do this maths,
 239                          * and also only floating point numbers can deal with the pretty large numbers
 240                          * involved in the total throughput of a server over a large period of time.
 241                          * (we dont count 64 bit ints because not all systems have 64 bit ints, and floats
 242                          * can still hold more.
 243                          */
 244                         float outbound_r = 100 - ((total_out_compressed / (total_out_uncompressed + 0.001)) * 100);
 245                         float inbound_r = 100 - ((total_in_compressed / (total_in_uncompressed + 0.001)) * 100);
 246
 247                         float total_compressed = total_in_compressed + total_out_compressed;
 248                         float total_uncompressed = total_in_uncompressed + total_out_uncompressed;
 249
 250                         float total_r = 100 - ((total_compressed / (total_uncompressed + 0.001)) * 100);
 251
 252                         char outbound_ratio[MAXBUF], inbound_ratio[MAXBUF], combined_ratio[MAXBUF];
 253
 254                         sprintf(outbound_ratio, "%3.2f%%", outbound_r);
 255                         sprintf(inbound_ratio, "%3.2f%%", inbound_r);
 256                         sprintf(combined_ratio, "%3.2f%%", total_r);
 257
 258                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS outbound_compressed   = "+ConvToStr(total_out_compressed));
 259                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS inbound_compressed    = "+ConvToStr(total_in_compressed));
 260                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS outbound_uncompressed = "+ConvToStr(total_out_uncompressed));
 261                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS inbound_uncompressed  = "+ConvToStr(total_in_uncompressed));
 262                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS outbound_ratio        = "+outbound_ratio);
 263                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS inbound_ratio         = "+inbound_ratio);
 264                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS combined_ratio        = "+combined_ratio);
 265                         return 0;
 266                 }
 267
 268                 return 0;
 269         }
 270
 271         virtual void OnRawSocketAccept(int fd, const std::string &ip, int localport)
 272         {
 273                 izip_session* session = &sessions[fd];
 274
 275                 /* allocate state and buffers */
 276                 session->fd = fd;
 277                 session->status = IZIP_OPEN;
 278                 session->inbuf = new CountedBuffer();
 279
 280                 session->c_stream.zalloc = (alloc_func)0;
 281                 session->c_stream.zfree = (free_func)0;
 282                 session->c_stream.opaque = (voidpf)0;
 283
 284                 session->d_stream.zalloc = (alloc_func)0;
 285                 session->d_stream.zfree = (free_func)0;
 286                 session->d_stream.opaque = (voidpf)0;
 287         }
 288
 289         virtual void OnRawSocketConnect(int fd)
 290         {
 291                 /* Nothing special needs doing here compared to accept() */
 292                 OnRawSocketAccept(fd, "", 0);
 293         }
 294
 295         virtual void OnRawSocketClose(int fd)
 296         {
 297                 CloseSession(&sessions[fd]);
 298         }
 299
 300         virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
 301         {
 302                 /* Find the sockets session */
 303                 izip_session* session = &sessions[fd];
 304
 305                 if (session->status == IZIP_CLOSED)
 306                         return 0;
 307
 308                 unsigned char compr[CHUNK + 4];
 309                 unsigned int offset = 0;
 310                 unsigned int total_size = 0;
 311
 312                 /* Read CHUNK bytes at a time to the buffer (usually 128k) */
 313                 readresult = read(fd, compr, CHUNK);
 314
 315                 /* Did we get anything? */
 316                 if (readresult > 0)
 317                 {
 318                         /* Add it to the frame queue */
 319                         session->inbuf->AddData(compr, readresult);
 320
 321                         /* Parse all completed frames */
 322                         int size = 0;
 323                         while ((size = session->inbuf->GetFrame(compr, CHUNK)) != 0)
 324                         {
 325                                 session->d_stream.next_in  = (Bytef*)compr;
 326                                 session->d_stream.avail_in = 0;
 327                                 session->d_stream.next_out = (Bytef*)(buffer + offset);
 328
 329                                 if (inflateInit(&session->d_stream) != Z_OK)
 330                                         return -EBADF;
 331
 332                                 while ((session->d_stream.total_out < count) && (session->d_stream.total_in < (unsigned int)size))
 333                                 {
 334                                         session->d_stream.avail_in = session->d_stream.avail_out = 1;
 335                                         if (inflate(&session->d_stream, Z_NO_FLUSH) == Z_STREAM_END)
 336                                                 break;
 337                                 }
 338
 339                                 inflateEnd(&session->d_stream);
 340
 341                                 total_in_compressed += readresult;
 342                                 total_size += session->d_stream.total_out;
 343                                 total_in_uncompressed += session->d_stream.total_out;
 344                                 offset += session->d_stream.total_out;
 345                         }
 346
 347                         buffer[total_size] = 0;
 348                         readresult = total_size;
 349
 350                 }
 351                 return (readresult > 0);
 352         }
 353
 354         virtual int OnRawSocketWrite(int fd, const char* buffer, int count)
 355         {
 356                 izip_session* session = &sessions[fd];
 357                 int ocount = count;
 358
 359                 if (!count)     /* Nothing to do! */
 360                         return 0;
 361
 362                 if(session->status != IZIP_OPEN)
 363                 {
 364                         /* Seriously, wtf? */
 365                         CloseSession(session);
 366                         return 0;
 367                 }
 368
 369                 unsigned char compr[CHUNK + 4];
 370
 371                 /* Gentlemen, start your engines! */
 372                 if (deflateInit(&session->c_stream, Z_BEST_COMPRESSION) != Z_OK)
 373                 {
 374                         CloseSession(session);
 375                         return 0;
 376                 }
 377
 378                 /* Set buffer sizes (we reserve 4 bytes at the start of the
 379                  * buffer for the length counters)
 380                  */
 381                 session->c_stream.next_in  = (Bytef*)buffer;
 382                 session->c_stream.next_out = compr + 4;
 383
 384                 /* Compress the text */
 385                 while ((session->c_stream.total_in < (unsigned int)count) && (session->c_stream.total_out < CHUNK))
 386                 {
 387                         session->c_stream.avail_in = session->c_stream.avail_out = 1;
 388                         if (deflate(&session->c_stream, Z_NO_FLUSH) != Z_OK)
 389                         {
 390                                 CloseSession(session);
 391                                 return 0;
 392                         }
 393                 }
 394                 /* Finish the stream */
 395                 for (session->c_stream.avail_out = 1; deflate(&session->c_stream, Z_FINISH) != Z_STREAM_END; session->c_stream.avail_out = 1);
 396                 deflateEnd(&session->c_stream);
 397
 398                 total_out_uncompressed += ocount;
 399                 total_out_compressed += session->c_stream.total_out;
 400
 401                 /** Assemble the frame length onto the frame, in network byte order */
 402                 compr[0] = (session->c_stream.total_out >> 24);
 403                 compr[1] = (session->c_stream.total_out >> 16);
 404                 compr[2] = (session->c_stream.total_out >> 8);
 405                 compr[3] = (session->c_stream.total_out & 0xFF);
 406
 407                 /* Add compressed data plus leading length to the output buffer -
 408                  * Note, we may have incomplete half-sent frames in here.
 409                  */
 410                 session->outbuf.append((const char*)compr, session->c_stream.total_out + 4);
 411
 412                 /* Lets see how much we can send out */
 413                 int ret = write(fd, session->outbuf.data(), session->outbuf.length());
 414
 415                 /* Check for errors, and advance the buffer if any was sent */
 416                 if (ret > 0)
 417                         session->outbuf = session->outbuf.substr(ret);
 418                 else if (ret < 1)
 419                 {
 420                         if (ret == -1)
 421                         {
 422                                 if (errno == EAGAIN)
 423                                         return 0;
 424                                 else
 425                                 {
 426                                         session->outbuf = "";
 427                                         return 0;
 428                                 }
 429                         }
 430                         else
 431                         {
 432                                 session->outbuf = "";
 433                                 return 0;
 434                         }
 435                 }
 436
 437                 /* ALL LIES the lot of it, we havent really written
 438                  * this amount, but the layer above doesnt need to know.
 439                  */
 440                 return ocount;
 441         }
 442
 443         void CloseSession(izip_session* session)
 444         {
 445                 if (session->status = IZIP_OPEN)
 446                 {
 447                         session->status = IZIP_CLOSED;
 448                         session->outbuf = "";
 449                         delete session->inbuf;
 450                 }
 451         }
 452
 453 };
 454
 455 class ModuleZLibFactory : public ModuleFactory
 456 {
 457  public:
 458         ModuleZLibFactory()
 459         {
 460         }
 461
 462         ~ModuleZLibFactory()
 463         {
 464         }
 465
 466         virtual Module * CreateModule(InspIRCd* Me)
 467         {
 468                 return new ModuleZLib(Me);
 469         }
 470 };
 471
 472
 473 extern "C" void * init_module( void )
 474 {
 475         return new ModuleZLibFactory;
 476 }