src/modules/extra/m_ziplink.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2007 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 "zlib.h"
  15
  16 #include "inspircd_config.h"
  17 #include "configreader.h"
  18 #include "users.h"
  19 #include "channels.h"
  20 #include "modules.h"
  21
  22 #include "socket.h"
  23 #include "hashcomp.h"
  24 #include "inspircd.h"
  25
  26 #include "transport.h"
  27
  28 /* $ModDesc: Provides zlib link support for servers */
  29 /* $LinkerFlags: -lz */
  30 /* $ModDep: transport.h */
  31
  32 /*
  33  * Compressed data is transmitted across the link in the following format:
  34  *
  35  *   0   1   2   3   4 ... n
  36  * +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
  37  * |       n       |              Z0 -> Zn                         |
  38  * +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
  39  *
  40  * Where: n is the size of a frame, in network byte order, 4 bytes.
  41  * Z0 through Zn are Zlib compressed data, n bytes in length.
  42  *
  43  * If the module fails to read the entire frame, then it will buffer
  44  * the portion of the last frame it received, then attempt to read
  45  * the next part of the frame next time a write notification arrives.
  46  *
  47  * ZLIB_BEST_COMPRESSION (9) is used for all sending of data with
  48  * a flush after each frame. A frame may contain multiple lines
  49  * and should be treated as raw binary data.
  50  *
  51  */
  52
  53 /* Status of a connection */
  54 enum izip_status { IZIP_OPEN, IZIP_CLOSED };
  55
  56 /* Maximum transfer size per read operation */
  57 const unsigned int CHUNK = 128 * 1024;
  58
  59 /* This class manages a compressed chunk of data preceeded by
  60  * a length count.
  61  *
  62  * It can handle having multiple chunks of data in the buffer
  63  * at any time.
  64  */
  65 class CountedBuffer : public classbase
  66 {
  67         std::string buffer;             /* Current buffer contents */
  68         unsigned int amount_expected;   /* Amount of data expected */
  69  public:
  70         CountedBuffer()
  71         {
  72                 amount_expected = 0;
  73         }
  74
  75         /** Adds arbitrary compressed data to the buffer.
  76          * - Binsry safe, of course.
  77          */
  78         void AddData(unsigned char* data, int data_length)
  79         {
  80                 buffer.append((const char*)data, data_length);
  81                 this->NextFrameSize();
  82         }
  83
  84         /** Works out the size of the next compressed frame
  85          */
  86         void NextFrameSize()
  87         {
  88                 if ((!amount_expected) && (buffer.length() >= 4))
  89                 {
  90                         /* We have enough to read an int -
  91                          * Yes, this is safe, but its ugly. Give me
  92                          * a nicer way to read 4 bytes from a binary
  93                          * stream, and push them into a 32 bit int,
  94                          * and i'll consider replacing this.
  95                          */
  96                         amount_expected = ntohl((buffer[3] << 24) | (buffer[2] << 16) | (buffer[1] << 8) | buffer[0]);
  97                         buffer = buffer.substr(4);
  98                 }
  99         }
 100
 101         /** Gets the next frame and returns its size, or returns
 102          * zero if there isnt one available yet.
 103          * A frame can contain multiple plaintext lines.
 104          * - Binary safe.
 105          */
 106         int GetFrame(unsigned char* frame, int maxsize)
 107         {
 108                 if (amount_expected)
 109                 {
 110                         /* We know how much we're expecting...
 111                          * Do we have enough yet?
 112                          */
 113                         if (buffer.length() >= amount_expected)
 114                         {
 115                                 int j = 0;
 116                                 for (unsigned int i = 0; i < amount_expected; i++, j++)
 117                                         frame[i] = buffer[i];
 118
 119                                 buffer = buffer.substr(j);
 120                                 amount_expected = 0;
 121                                 NextFrameSize();
 122                                 return j;
 123                         }
 124                 }
 125                 /* Not enough for a frame yet, COME AGAIN! */
 126                 return 0;
 127         }
 128 };
 129
 130 /** Represents an zipped connections extra data
 131  */
 132 class izip_session : public classbase
 133 {
 134  public:
 135         z_stream c_stream;      /* compression stream */
 136         z_stream d_stream;      /* decompress stream */
 137         izip_status status;     /* Connection status */
 138         int fd;                 /* File descriptor */
 139         CountedBuffer* inbuf;   /* Holds input buffer */
 140         std::string outbuf;     /* Holds output buffer */
 141 };
 142
 143 class ModuleZLib : public Module
 144 {
 145         izip_session sessions[MAX_DESCRIPTORS];
 146
 147         /* Used for stats z extensions */
 148         float total_out_compressed;
 149         float total_in_compressed;
 150         float total_out_uncompressed;
 151         float total_in_uncompressed;
 152
 153  public:
 154
 155         ModuleZLib(InspIRCd* Me)
 156                 : Module::Module(Me)
 157         {
 158                 ServerInstance->PublishInterface("InspSocketHook", this);
 159
 160                 total_out_compressed = total_in_compressed = 0;
 161                 total_out_uncompressed = total_out_uncompressed = 0;
 162         }
 163
 164         virtual ~ModuleZLib()
 165         {
 166                 ServerInstance->UnpublishInterface("InspSocketHook", this);
 167         }
 168
 169         virtual Version GetVersion()
 170         {
 171                 return Version(1, 1, 0, 0, VF_VENDOR, API_VERSION);
 172         }
 173
 174         void Implements(char* List)
 175         {
 176                 List[I_OnRawSocketConnect] = List[I_OnRawSocketAccept] = List[I_OnRawSocketClose] = List[I_OnRawSocketRead] = List[I_OnRawSocketWrite] = 1;
 177                 List[I_OnStats] = List[I_OnRequest] = 1;
 178         }
 179
 180         /* Handle InspSocketHook API requests */
 181         virtual char* OnRequest(Request* request)
 182         {
 183                 ISHRequest* ISR = (ISHRequest*)request;
 184                 if (strcmp("IS_NAME", request->GetId()) == 0)
 185                 {
 186                         /* Return name */
 187                         return "zip";
 188                 }
 189                 else if (strcmp("IS_HOOK", request->GetId()) == 0)
 190                 {
 191                         /* Attach to an inspsocket */
 192                         char* ret = "OK";
 193                         try
 194                         {
 195                                 ret = ServerInstance->Config->AddIOHook((Module*)this, (InspSocket*)ISR->Sock) ? (char*)"OK" : NULL;
 196                         }
 197                         catch (ModuleException& e)
 198                         {
 199                                 return NULL;
 200                         }
 201                         return ret;
 202                 }
 203                 else if (strcmp("IS_UNHOOK", request->GetId()) == 0)
 204                 {
 205                         /* Detatch from an inspsocket */
 206                         return ServerInstance->Config->DelIOHook((InspSocket*)ISR->Sock) ? (char*)"OK" : NULL;
 207                 }
 208                 else if (strcmp("IS_HSDONE", request->GetId()) == 0)
 209                 {
 210                         /* Check for completion of handshake
 211                          * (actually, this module doesnt handshake)
 212                          */
 213                         return "OK";
 214                 }
 215                 else if (strcmp("IS_ATTACH", request->GetId()) == 0)
 216                 {
 217                         /* Attach certificate data to the inspsocket
 218                          * (this module doesnt do that, either)
 219                          */
 220                         return NULL;
 221                 }
 222                 return NULL;
 223         }
 224
 225         /* Handle stats z (misc stats) */
 226         virtual int OnStats(char symbol, userrec* user, string_list &results)
 227         {
 228                 if (symbol == 'z')
 229                 {
 230                         std::string sn = ServerInstance->Config->ServerName;
 231
 232                         /* Yeah yeah, i know, floats are ew.
 233                          * We used them here because we'd be casting to float anyway to do this maths,
 234                          * and also only floating point numbers can deal with the pretty large numbers
 235                          * involved in the total throughput of a server over a large period of time.
 236                          * (we dont count 64 bit ints because not all systems have 64 bit ints, and floats
 237                          * can still hold more.
 238                          */
 239                         float outbound_r = 100 - ((total_out_compressed / (total_out_uncompressed + 0.001)) * 100);
 240                         float inbound_r = 100 - ((total_in_compressed / (total_in_uncompressed + 0.001)) * 100);
 241
 242                         float total_compressed = total_in_compressed + total_out_compressed;
 243                         float total_uncompressed = total_in_uncompressed + total_out_uncompressed;
 244
 245                         float total_r = 100 - ((total_compressed / (total_uncompressed + 0.001)) * 100);
 246
 247                         char outbound_ratio[MAXBUF], inbound_ratio[MAXBUF], combined_ratio[MAXBUF];
 248
 249                         sprintf(outbound_ratio, "%3.2f%%", outbound_r);
 250                         sprintf(inbound_ratio, "%3.2f%%", inbound_r);
 251                         sprintf(combined_ratio, "%3.2f%%", total_r);
 252
 253                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS outbound_compressed   = "+ConvToStr(total_out_compressed));
 254                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS inbound_compressed    = "+ConvToStr(total_in_compressed));
 255                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS outbound_uncompressed = "+ConvToStr(total_out_uncompressed));
 256                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS inbound_uncompressed  = "+ConvToStr(total_in_uncompressed));
 257                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS outbound_ratio        = "+outbound_ratio);
 258                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS inbound_ratio         = "+inbound_ratio);
 259                         results.push_back(sn+" 304 "+user->nick+" :ZIPSTATS combined_ratio        = "+combined_ratio);
 260                         return 0;
 261                 }
 262
 263                 return 0;
 264         }
 265
 266         virtual void OnRawSocketAccept(int fd, const std::string &ip, int localport)
 267         {
 268                 izip_session* session = &sessions[fd];
 269
 270                 /* allocate state and buffers */
 271                 session->fd = fd;
 272                 session->status = IZIP_OPEN;
 273                 session->inbuf = new CountedBuffer();
 274
 275                 session->c_stream.zalloc = (alloc_func)0;
 276                 session->c_stream.zfree = (free_func)0;
 277                 session->c_stream.opaque = (voidpf)0;
 278
 279                 session->d_stream.zalloc = (alloc_func)0;
 280                 session->d_stream.zfree = (free_func)0;
 281                 session->d_stream.opaque = (voidpf)0;
 282         }
 283
 284         virtual void OnRawSocketConnect(int fd)
 285         {
 286                 /* Nothing special needs doing here compared to accept() */
 287                 OnRawSocketAccept(fd, "", 0);
 288         }
 289
 290         virtual void OnRawSocketClose(int fd)
 291         {
 292                 CloseSession(&sessions[fd]);
 293         }
 294
 295         virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
 296         {
 297                 /* Find the sockets session */
 298                 izip_session* session = &sessions[fd];
 299
 300                 if (session->status == IZIP_CLOSED)
 301                         return 0;
 302
 303                 unsigned char compr[CHUNK + 4];
 304                 unsigned int offset = 0;
 305                 unsigned int total_size = 0;
 306
 307                 /* Read CHUNK bytes at a time to the buffer (usually 128k) */
 308                 readresult = read(fd, compr, CHUNK);
 309
 310                 /* Did we get anything? */
 311                 if (readresult > 0)
 312                 {
 313                         /* Add it to the frame queue */
 314                         session->inbuf->AddData(compr, readresult);
 315                         total_in_compressed += readresult;
 316
 317                         /* Parse all completed frames */
 318                         int size = 0;
 319                         while ((size = session->inbuf->GetFrame(compr, CHUNK)) != 0)
 320                         {
 321                                 session->d_stream.next_in  = (Bytef*)compr;
 322                                 session->d_stream.avail_in = 0;
 323                                 session->d_stream.next_out = (Bytef*)(buffer + offset);
 324
 325                                 /* If we cant call this, well, we're boned. */
 326                                 if (inflateInit(&session->d_stream) != Z_OK)
 327                                         return 0;
 328
 329                                 while ((session->d_stream.total_out < count) && (session->d_stream.total_in < (unsigned int)size))
 330                                 {
 331                                         session->d_stream.avail_in = session->d_stream.avail_out = 1;
 332                                         if (inflate(&session->d_stream, Z_NO_FLUSH) == Z_STREAM_END)
 333                                                 break;
 334                                 }
 335
 336                                 /* Stick a fork in me, i'm done */
 337                                 inflateEnd(&session->d_stream);
 338
 339                                 /* Update counters and offsets */
 340                                 total_size += session->d_stream.total_out;
 341                                 total_in_uncompressed += session->d_stream.total_out;
 342                                 offset += session->d_stream.total_out;
 343                         }
 344
 345                         /* Null-terminate the buffer -- this doesnt harm binary data */
 346                         buffer[total_size] = 0;
 347
 348                         /* Set the read size to the correct total size */
 349                         readresult = total_size;
 350
 351                 }
 352                 return (readresult > 0);
 353         }
 354
 355         virtual int OnRawSocketWrite(int fd, const char* buffer, int count)
 356         {
 357                 izip_session* session = &sessions[fd];
 358                 int ocount = count;
 359
 360                 if (!count)     /* Nothing to do! */
 361                         return 0;
 362
 363                 if(session->status != IZIP_OPEN)
 364                 {
 365                         /* Seriously, wtf? */
 366                         CloseSession(session);
 367                         return 0;
 368                 }
 369
 370                 unsigned char compr[CHUNK + 4];
 371
 372                 /* Gentlemen, start your engines! */
 373                 if (deflateInit(&session->c_stream, Z_BEST_COMPRESSION) != Z_OK)
 374                 {
 375                         CloseSession(session);
 376                         return 0;
 377                 }
 378
 379                 /* Set buffer sizes (we reserve 4 bytes at the start of the
 380                  * buffer for the length counters)
 381                  */
 382                 session->c_stream.next_in  = (Bytef*)buffer;
 383                 session->c_stream.next_out = compr + 4;
 384
 385                 /* Compress the text */
 386                 while ((session->c_stream.total_in < (unsigned int)count) && (session->c_stream.total_out < CHUNK))
 387                 {
 388                         session->c_stream.avail_in = session->c_stream.avail_out = 1;
 389                         if (deflate(&session->c_stream, Z_NO_FLUSH) != Z_OK)
 390                         {
 391                                 CloseSession(session);
 392                                 return 0;
 393                         }
 394                 }
 395                 /* Finish the stream */
 396                 for (session->c_stream.avail_out = 1; deflate(&session->c_stream, Z_FINISH) != Z_STREAM_END; session->c_stream.avail_out = 1);
 397                 deflateEnd(&session->c_stream);
 398
 399                 total_out_uncompressed += ocount;
 400                 total_out_compressed += session->c_stream.total_out;
 401
 402                 /** Assemble the frame length onto the frame, in network byte order */
 403                 compr[0] = (session->c_stream.total_out >> 24);
 404                 compr[1] = (session->c_stream.total_out >> 16);
 405                 compr[2] = (session->c_stream.total_out >> 8);
 406                 compr[3] = (session->c_stream.total_out & 0xFF);
 407
 408                 /* Add compressed data plus leading length to the output buffer -
 409                  * Note, we may have incomplete half-sent frames in here.
 410                  */
 411                 session->outbuf.append((const char*)compr, session->c_stream.total_out + 4);
 412
 413                 /* Lets see how much we can send out */
 414                 int ret = write(fd, session->outbuf.data(), session->outbuf.length());
 415
 416                 /* Check for errors, and advance the buffer if any was sent */
 417                 if (ret > 0)
 418                         session->outbuf = session->outbuf.substr(ret);
 419                 else if (ret < 1)
 420                 {
 421                         if (ret == -1)
 422                         {
 423                                 if (errno == EAGAIN)
 424                                         return 0;
 425                                 else
 426                                 {
 427                                         session->outbuf = "";
 428                                         return 0;
 429                                 }
 430                         }
 431                         else
 432                         {
 433                                 session->outbuf = "";
 434                                 return 0;
 435                         }
 436                 }
 437
 438                 /* ALL LIES the lot of it, we havent really written
 439                  * this amount, but the layer above doesnt need to know.
 440                  */
 441                 return ocount;
 442         }
 443
 444         void CloseSession(izip_session* session)
 445         {
 446                 if (session->status == IZIP_OPEN)
 447                 {
 448                         session->status = IZIP_CLOSED;
 449                         session->outbuf = "";
 450                         delete session->inbuf;
 451                 }
 452         }
 453
 454 };
 455
 456 class ModuleZLibFactory : public ModuleFactory
 457 {
 458  public:
 459         ModuleZLibFactory()
 460         {
 461         }
 462
 463         ~ModuleZLibFactory()
 464         {
 465         }
 466
 467         virtual Module * CreateModule(InspIRCd* Me)
 468         {
 469                 return new ModuleZLib(Me);
 470         }
 471 };
 472
 473
 474 extern "C" void * init_module( void )
 475 {
 476         return new ModuleZLibFactory;
 477 }