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