lib/silccore/silcpacket.c

   1 /*
   2
   3   silcpacket.c
   4
   5   Author: Pekka Riikonen <priikone@silcnet.org>
   6
   7   Copyright (C) 1997 - 2008 Pekka Riikonen
   8
   9   This program is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU General Public License as published by
  11   the Free Software Foundation; version 2 of the License.
  12
  13   This program is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18 */
  19 /*
  20  * Created: Fri Jul 25 18:52:14 1997
  21  */
  22 /* $Id$ */
  23
  24 #include "silc.h"
  25
  26 /************************** Types and definitions ***************************/
  27
  28 /* Per scheduler (which usually means per thread) data.  We put per scheduler
  29    data here for accessing without locking.  SILC Schedule dictates that
  30    tasks are dispatched in one thread, hence the per scheduler context. */
  31 typedef struct {
  32   SilcSchedule schedule;                 /* The scheduler */
  33   SilcPacketEngine engine;               /* Packet engine */
  34   SilcDList inbufs;                      /* Data inbut buffer list */
  35   SilcUInt32 stream_count;               /* Number of streams using this */
  36 } *SilcPacketEngineContext;
  37
  38 /* Packet engine */
  39 struct SilcPacketEngineStruct {
  40   SilcMutex lock;                        /* Engine lock */
  41   SilcRng rng;                           /* RNG for engine */
  42   SilcHashTable contexts;                /* Per scheduler contexts */
  43   const SilcPacketCallbacks *callbacks;  /* Packet callbacks */
  44   void *callback_context;                /* Context for callbacks */
  45   SilcList streams;                      /* All streams in engine */
  46   SilcList packet_pool;                  /* Free list for received packets */
  47   SilcHashTable udp_remote;              /* UDP remote streams, or NULL */
  48   unsigned int local_is_router    : 1;
  49 };
  50
  51 /* Packet processor context */
  52 typedef struct SilcPacketProcessStruct {
  53   SilcPacketType *types;                 /* Packets to process */
  54   const SilcPacketCallbacks *callbacks;  /* Callbacks or NULL */
  55   void *callback_context;
  56   SilcInt32 priority;                    /* Priority */
  57 } *SilcPacketProcess;
  58
  59 /* UDP remote stream tuple */
  60 typedef struct {
  61   char *remote_ip;                       /* Remote IP address */
  62   SilcUInt16 remote_port;                /* Remote port */
  63 } *SilcPacketRemoteUDP;
  64
  65 /* Packet stream */
  66 struct SilcPacketStreamStruct {
  67   struct SilcPacketStreamStruct *next;
  68   SilcPacketEngineContext sc;            /* Per scheduler context */
  69   SilcStream stream;                     /* Underlaying stream */
  70   SilcMutex lock;                        /* Packet stream lock */
  71   SilcDList process;                     /* Packet processors, or NULL */
  72   SilcPacketRemoteUDP remote_udp;        /* UDP remote stream tuple, or NULL */
  73   void *stream_context;                  /* Stream context */
  74   SilcBufferStruct outbuf;               /* Out buffer */
  75   SilcBuffer inbuf;                      /* Inbuf from inbuf list or NULL */
  76   SilcCipher send_key[2];                /* Sending key */
  77   SilcHmac send_hmac[2];                 /* Sending HMAC */
  78   SilcCipher receive_key[2];             /* Receiving key */
  79   SilcHmac receive_hmac[2];              /* Receiving HMAC */
  80   unsigned char *src_id;                 /* Source ID */
  81   unsigned char *dst_id;                 /* Destination ID */
  82   SilcUInt32 send_psn;                   /* Sending sequence */
  83   SilcUInt32 receive_psn;                /* Receiving sequence */
  84   SilcAtomic32 refcnt;                   /* Reference counter */
  85   SilcUInt8 sid;                         /* Security ID, set if IV included */
  86   unsigned int src_id_len  : 6;
  87   unsigned int src_id_type : 2;
  88   unsigned int dst_id_len  : 6;
  89   unsigned int dst_id_type : 2;
  90   unsigned int is_router   : 1;          /* Set if router stream */
  91   unsigned int destroyed   : 1;          /* Set if destroyed */
  92   unsigned int iv_included : 1;          /* Set if IV included */
  93   unsigned int udp         : 1;          /* UDP remote stream */
  94 };
  95
  96 /* Initial size of stream buffers */
  97 #define SILC_PACKET_DEFAULT_SIZE  1024
  98
  99 /* Header length without source and destination ID's. */
 100 #define SILC_PACKET_HEADER_LEN 10
 101
 102 /* Minimum length of SILC Packet Header. */
 103 #define SILC_PACKET_MIN_HEADER_LEN 16
 104 #define SILC_PACKET_MIN_HEADER_LEN_IV 32 + 1
 105
 106 /* Maximum padding length */
 107 #define SILC_PACKET_MAX_PADLEN 128
 108
 109 /* Default padding length */
 110 #define SILC_PACKET_DEFAULT_PADLEN 16
 111
 112 /* Minimum packet length */
 113 #define SILC_PACKET_MIN_LEN (SILC_PACKET_HEADER_LEN + 1)
 114
 115 /* Returns true length of the packet. */
 116 #define SILC_PACKET_LENGTH(__packetdata, __ret_truelen, __ret_paddedlen) \
 117 do {                                                                     \
 118   SILC_GET16_MSB((__ret_truelen), (__packetdata));                       \
 119   (__ret_paddedlen) = (__ret_truelen) + (SilcUInt8)(__packetdata)[4];    \
 120 } while(0)
 121
 122 /* Calculates the data length with given header length.  This macro
 123    can be used to check whether the data_len with header_len exceeds
 124    SILC_PACKET_MAX_LEN.  If it does, this returns the new data_len
 125    so that the SILC_PACKET_MAX_LEN is not exceeded.  If the data_len
 126    plus header_len fits SILC_PACKET_MAX_LEN the returned data length
 127    is the data_len given as argument. */
 128 #define SILC_PACKET_DATALEN(data_len, header_len)                         \
 129   ((data_len + header_len) > SILC_PACKET_MAX_LEN ?                        \
 130    data_len - ((data_len + header_len) - SILC_PACKET_MAX_LEN) : data_len)
 131
 132 /* Calculates the length of the padding in the packet. */
 133 #define SILC_PACKET_PADLEN(__packetlen, __blocklen, __padlen)               \
 134 do {                                                                        \
 135   __padlen = (SILC_PACKET_DEFAULT_PADLEN - (__packetlen) %                  \
 136               ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN));  \
 137   if (__padlen < 8)                                                         \
 138     __padlen += ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN); \
 139 } while(0)
 140
 141 /* Returns the length of the padding up to the maximum length, which
 142    is 128 bytes.*/
 143 #define SILC_PACKET_PADLEN_MAX(__packetlen, __blocklen, __padlen)          \
 144 do {                                                                       \
 145   __padlen = (SILC_PACKET_MAX_PADLEN - (__packetlen) %                     \
 146               ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN)); \
 147 } while(0)
 148
 149 /* EOS callback */
 150 #define SILC_PACKET_CALLBACK_EOS(s)                                     \
 151 do {                                                                    \
 152   (s)->sc->engine->callbacks->eos((s)->sc->engine, s,                   \
 153                                   (s)->sc->engine->callback_context,    \
 154                                   (s)->stream_context);                 \
 155 } while(0)
 156
 157 /* Error callback */
 158 #define SILC_PACKET_CALLBACK_ERROR(s, err)                              \
 159 do {                                                                    \
 160   (s)->sc->engine->callbacks->error((s)->sc->engine, s, err,            \
 161                                     (s)->sc->engine->callback_context,  \
 162                                     (s)->stream_context);               \
 163 } while(0)
 164
 165 static SilcBool silc_packet_dispatch(SilcPacket packet);
 166 static void silc_packet_read_process(SilcPacketStream stream);
 167 static inline SilcBool silc_packet_send_raw(SilcPacketStream stream,
 168                                             SilcPacketType type,
 169                                             SilcPacketFlags flags,
 170                                             SilcIdType src_id_type,
 171                                             unsigned char *src_id,
 172                                             SilcUInt32 src_id_len,
 173                                             SilcIdType dst_id_type,
 174                                             unsigned char *dst_id,
 175                                             SilcUInt32 dst_id_len,
 176                                             const unsigned char *data,
 177                                             SilcUInt32 data_len,
 178                                             SilcCipher cipher,
 179                                             SilcHmac hmac);
 180
 181 /************************ Static utility functions **************************/
 182
 183 /* Injects packet to new stream created with silc_packet_stream_add_remote. */
 184
 185 SILC_TASK_CALLBACK(silc_packet_stream_inject_packet)
 186 {
 187   SilcPacket packet = context;
 188   SilcPacketStream stream = packet->stream;
 189
 190   SILC_LOG_DEBUG(("Injecting packet %p to stream %p", packet, packet->stream));
 191
 192   silc_mutex_lock(stream->lock);
 193   if (!stream->destroyed)
 194     silc_packet_dispatch(packet);
 195   silc_mutex_unlock(stream->lock);
 196   silc_packet_stream_unref(stream);
 197 }
 198
 199 /* Write data to the stream.  Must be called with ps->lock locked.  Unlocks
 200    the lock inside this function, unless no_unlock is TRUE.  Unlocks always
 201    in case it returns FALSE. */
 202
 203 static inline SilcBool silc_packet_stream_write(SilcPacketStream ps,
 204                                                 SilcBool no_unlock)
 205 {
 206   SilcStream stream;
 207   SilcBool connected;
 208   int i;
 209
 210   if (ps->udp)
 211     stream = ((SilcPacketStream)ps->stream)->stream;
 212   else
 213     stream = ps->stream;
 214
 215   if (ps->udp && silc_socket_stream_is_udp(stream, &connected)) {
 216     if (!connected) {
 217       /* Connectionless UDP stream */
 218       while (silc_buffer_len(&ps->outbuf) > 0) {
 219         i = silc_net_udp_send(stream, ps->remote_udp->remote_ip,
 220                               ps->remote_udp->remote_port,
 221                               ps->outbuf.data, silc_buffer_len(&ps->outbuf));
 222         if (silc_unlikely(i == -2)) {
 223           /* Error */
 224           silc_buffer_reset(&ps->outbuf);
 225           SILC_PACKET_CALLBACK_ERROR(ps, SILC_PACKET_ERR_WRITE);
 226           return FALSE;
 227         }
 228
 229         if (silc_unlikely(i == -1)) {
 230           /* Cannot write now, write later. */
 231           if (!no_unlock)
 232             silc_mutex_unlock(ps->lock);
 233           return TRUE;
 234         }
 235
 236         /* Wrote data */
 237         silc_buffer_pull(&ps->outbuf, i);
 238       }
 239
 240       silc_buffer_reset(&ps->outbuf);
 241       if (!no_unlock)
 242         silc_mutex_unlock(ps->lock);
 243
 244       return TRUE;
 245     }
 246   }
 247
 248   /* Write the data to the stream */
 249   while (silc_buffer_len(&ps->outbuf) > 0) {
 250     i = silc_stream_write(stream, ps->outbuf.data,
 251                           silc_buffer_len(&ps->outbuf));
 252     if (silc_unlikely(i == 0)) {
 253       /* EOS */
 254       silc_buffer_reset(&ps->outbuf);
 255       silc_mutex_unlock(ps->lock);
 256       SILC_PACKET_CALLBACK_EOS(ps);
 257       return FALSE;
 258     }
 259
 260     if (silc_unlikely(i == -2)) {
 261       /* Error */
 262       silc_buffer_reset(&ps->outbuf);
 263       silc_mutex_unlock(ps->lock);
 264       SILC_PACKET_CALLBACK_ERROR(ps, SILC_PACKET_ERR_WRITE);
 265       return FALSE;
 266     }
 267
 268     if (silc_unlikely(i == -1)) {
 269       /* Cannot write now, write later. */
 270       if (!no_unlock)
 271         silc_mutex_unlock(ps->lock);
 272       return TRUE;
 273     }
 274
 275     /* Wrote data */
 276     silc_buffer_pull(&ps->outbuf, i);
 277   }
 278
 279   silc_buffer_reset(&ps->outbuf);
 280   if (!no_unlock)
 281     silc_mutex_unlock(ps->lock);
 282
 283   return TRUE;
 284 }
 285
 286 /* Reads data from stream.  Must be called with ps->lock locked.  If this
 287    returns FALSE the lock has been unlocked.  If this returns packet stream
 288    to `ret_ps' its lock has been acquired and `ps' lock has been unlocked.
 289    It is returned if the stream is UDP and remote UDP stream exists for
 290    the sender of the packet. */
 291
 292 static inline SilcBool silc_packet_stream_read(SilcPacketStream ps,
 293                                                SilcPacketStream *ret_ps)
 294 {
 295   SilcStream stream = ps->stream;
 296   SilcBuffer inbuf;
 297   SilcBool connected;
 298   int ret;
 299
 300   /* Get inbuf.  If there is already some data for this stream in the buffer
 301      we already have it.  Otherwise get the current one from list, it will
 302      include the data. */
 303   inbuf = ps->inbuf;
 304   if (!inbuf) {
 305     silc_dlist_start(ps->sc->inbufs);
 306     inbuf = silc_dlist_get(ps->sc->inbufs);
 307     if (!inbuf) {
 308       /* Allocate new data input buffer */
 309       inbuf = silc_buffer_alloc(SILC_PACKET_DEFAULT_SIZE * 65);
 310       if (!inbuf) {
 311         silc_mutex_unlock(ps->lock);
 312         return FALSE;
 313       }
 314       silc_buffer_reset(inbuf);
 315       silc_dlist_add(ps->sc->inbufs, inbuf);
 316     }
 317   }
 318
 319   /* Make sure there is enough room to read */
 320   if (SILC_PACKET_DEFAULT_SIZE * 2 > silc_buffer_taillen(inbuf))
 321     silc_buffer_realloc(inbuf, silc_buffer_truelen(inbuf) +
 322                         (SILC_PACKET_DEFAULT_SIZE * 2));
 323
 324   if (silc_socket_stream_is_udp(stream, &connected)) {
 325     if (!connected) {
 326       /* Connectionless UDP stream, read one UDP packet */
 327       char remote_ip[64], tuple[64];
 328       int remote_port;
 329       SilcPacketStream remote;
 330
 331       ret = silc_net_udp_receive(stream, remote_ip, sizeof(remote_ip),
 332                                  &remote_port, inbuf->tail,
 333                                  silc_buffer_taillen(inbuf));
 334
 335       if (silc_unlikely(ret < 0)) {
 336         silc_mutex_unlock(ps->lock);
 337         if (ret == -1) {
 338           /* Cannot read now, do it later. */
 339           return FALSE;
 340         }
 341
 342         /* Error */
 343         silc_buffer_reset(inbuf);
 344         SILC_PACKET_CALLBACK_ERROR(ps, SILC_PACKET_ERR_READ);
 345         return FALSE;
 346       }
 347
 348       /* See if remote packet stream exist for this sender */
 349       silc_snprintf(tuple, sizeof(tuple), "%d%s", remote_port, remote_ip);
 350       silc_mutex_lock(ps->sc->engine->lock);
 351       if (silc_hash_table_find(ps->sc->engine->udp_remote, tuple, NULL,
 352                                (void *)&remote)) {
 353         silc_mutex_unlock(ps->sc->engine->lock);
 354         SILC_LOG_DEBUG(("UDP packet from %s:%d for stream %p", remote_ip,
 355                         remote_port, remote));
 356         silc_mutex_unlock(ps->lock);
 357         silc_mutex_lock(remote->lock);
 358         *ret_ps = remote;
 359         return TRUE;
 360       }
 361       silc_mutex_unlock(ps->sc->engine->lock);
 362
 363       /* Unknown sender */
 364       if (!ps->remote_udp) {
 365         ps->remote_udp = silc_calloc(1, sizeof(*ps->remote_udp));
 366         if (silc_unlikely(!ps->remote_udp)) {
 367           silc_mutex_unlock(ps->lock);
 368           SILC_PACKET_CALLBACK_ERROR(ps, SILC_PACKET_ERR_NO_MEMORY);
 369           return FALSE;
 370         }
 371       }
 372
 373       /* Save sender IP and port */
 374       silc_free(ps->remote_udp->remote_ip);
 375       ps->remote_udp->remote_ip = strdup(remote_ip);
 376       ps->remote_udp->remote_port = remote_port;
 377
 378       silc_buffer_pull_tail(inbuf, ret);
 379       return TRUE;
 380     }
 381   }
 382
 383   /* Read data from the stream */
 384   ret = silc_stream_read(stream, inbuf->tail, silc_buffer_taillen(inbuf));
 385   if (silc_unlikely(ret <= 0)) {
 386     silc_mutex_unlock(ps->lock);
 387     if (ret == 0) {
 388       /* EOS */
 389       silc_buffer_reset(inbuf);
 390       SILC_PACKET_CALLBACK_EOS(ps);
 391       return FALSE;
 392     }
 393
 394     if (ret == -1) {
 395       /* Cannot read now, do it later. */
 396       return FALSE;
 397     }
 398
 399     /* Error */
 400     silc_buffer_reset(inbuf);
 401     SILC_PACKET_CALLBACK_ERROR(ps, SILC_PACKET_ERR_READ);
 402     return FALSE;
 403   }
 404
 405   silc_buffer_pull_tail(inbuf, ret);
 406   return TRUE;
 407 }
 408
 409 /* Our stream IO notifier callback. */
 410
 411 static void silc_packet_stream_io(SilcStream stream, SilcStreamStatus status,
 412                                   void *context)
 413 {
 414   SilcPacketStream remote = NULL, ps = context;
 415
 416   silc_mutex_lock(ps->lock);
 417
 418   if (silc_unlikely(ps->destroyed)) {
 419     silc_mutex_unlock(ps->lock);
 420     return;
 421   }
 422
 423   switch (status) {
 424   case SILC_STREAM_CAN_READ:
 425     /* Reading is locked also with stream->lock because we may be reading
 426        at the same time other thread is writing to same underlaying stream. */
 427     SILC_LOG_DEBUG(("Reading data from stream %p, ps %p", ps->stream, ps));
 428
 429     /* Read data from stream */
 430     if (!silc_packet_stream_read(ps, &remote))
 431       return;
 432
 433     /* Now process the data */
 434     silc_packet_stream_ref(ps);
 435     if (!remote) {
 436       silc_packet_read_process(ps);
 437       silc_mutex_unlock(ps->lock);
 438     } else {
 439       silc_packet_read_process(remote);
 440       silc_mutex_unlock(remote->lock);
 441     }
 442     silc_packet_stream_unref(ps);
 443     break;
 444
 445   case SILC_STREAM_CAN_WRITE:
 446     SILC_LOG_DEBUG(("Writing pending data to stream %p, ps %p",
 447                     ps->stream, ps));
 448
 449     if (silc_unlikely(!silc_buffer_headlen(&ps->outbuf))) {
 450       silc_mutex_unlock(ps->lock);
 451       return;
 452     }
 453
 454     /* Write pending data to stream */
 455     silc_packet_stream_write(ps, FALSE);
 456     break;
 457
 458   default:
 459     silc_mutex_unlock(ps->lock);
 460     break;
 461   }
 462 }
 463
 464 /* Allocate packet */
 465
 466 static SilcPacket silc_packet_alloc(SilcPacketEngine engine)
 467 {
 468   SilcPacket packet;
 469
 470   SILC_LOG_DEBUG(("Packet pool count %d",
 471                   silc_list_count(engine->packet_pool)));
 472
 473   silc_mutex_lock(engine->lock);
 474
 475   /* Get packet from freelist or allocate new one. */
 476   packet = silc_list_get(engine->packet_pool);
 477   if (!packet) {
 478     void *tmp;
 479
 480     silc_mutex_unlock(engine->lock);
 481
 482     packet = silc_calloc(1, sizeof(*packet));
 483     if (silc_unlikely(!packet))
 484       return NULL;
 485
 486     SILC_LOG_DEBUG(("Allocating new packet %p", packet));
 487
 488     tmp = silc_malloc(SILC_PACKET_DEFAULT_SIZE);
 489     if (silc_unlikely(!tmp)) {
 490       silc_free(packet);
 491       return NULL;
 492     }
 493     silc_buffer_set(&packet->buffer, tmp, SILC_PACKET_DEFAULT_SIZE);
 494     silc_buffer_reset(&packet->buffer);
 495
 496     return packet;
 497   }
 498
 499   SILC_LOG_DEBUG(("Get packet %p", packet));
 500
 501   /* Delete from freelist */
 502   silc_list_del(engine->packet_pool, packet);
 503
 504   silc_mutex_unlock(engine->lock);
 505
 506   return packet;
 507 }
 508
 509 /* UDP remote stream hash table destructor */
 510
 511 static void silc_packet_engine_hash_destr(void *key, void *context,
 512                                           void *user_context)
 513 {
 514   silc_free(key);
 515 }
 516
 517 /* Per scheduler context hash table destructor */
 518
 519 static void silc_packet_engine_context_destr(void *key, void *context,
 520                                              void *user_context)
 521 {
 522   SilcPacketEngineContext sc = context;
 523   SilcBuffer buffer;
 524
 525   silc_dlist_start(sc->inbufs);
 526   while ((buffer = silc_dlist_get(sc->inbufs))) {
 527     silc_buffer_clear(buffer);
 528     silc_buffer_free(buffer);
 529     silc_dlist_del(sc->inbufs, buffer);
 530   }
 531
 532   silc_dlist_uninit(sc->inbufs);
 533   silc_free(sc);
 534 }
 535
 536
 537 /******************************** Packet API ********************************/
 538
 539 /* Allocate new packet engine */
 540
 541 SilcPacketEngine
 542 silc_packet_engine_start(SilcRng rng, SilcBool router,
 543                          const SilcPacketCallbacks *callbacks,
 544                          void *callback_context)
 545 {
 546   SilcPacketEngine engine;
 547   SilcPacket packet;
 548   int i;
 549   void *tmp;
 550
 551   SILC_LOG_DEBUG(("Starting new packet engine"));
 552
 553   if (!callbacks)
 554     return NULL;
 555   if (!callbacks->packet_receive || !callbacks->eos || !callbacks->error)
 556     return NULL;
 557
 558   engine = silc_calloc(1, sizeof(*engine));
 559   if (!engine)
 560     return NULL;
 561
 562   engine->contexts = silc_hash_table_alloc(0, silc_hash_ptr, NULL, NULL, NULL,
 563                                            silc_packet_engine_context_destr,
 564                                            engine, TRUE);
 565   if (!engine->contexts) {
 566     silc_free(engine);
 567     return NULL;
 568   }
 569
 570   engine->rng = rng;
 571   engine->local_is_router = router;
 572   engine->callbacks = callbacks;
 573   engine->callback_context = callback_context;
 574   silc_list_init(engine->streams, struct SilcPacketStreamStruct, next);
 575   silc_mutex_alloc(&engine->lock);
 576
 577   /* Allocate packet free list */
 578   silc_list_init(engine->packet_pool, struct SilcPacketStruct, next);
 579   for (i = 0; i < 5; i++) {
 580     packet = silc_calloc(1, sizeof(*packet));
 581     if (!packet) {
 582       silc_packet_engine_stop(engine);
 583       return NULL;
 584     }
 585
 586     tmp = silc_malloc(SILC_PACKET_DEFAULT_SIZE);
 587     if (!tmp) {
 588       silc_packet_engine_stop(engine);
 589       return NULL;
 590     }
 591     silc_buffer_set(&packet->buffer, tmp, SILC_PACKET_DEFAULT_SIZE);
 592     silc_buffer_reset(&packet->buffer);
 593
 594     silc_list_add(engine->packet_pool, packet);
 595   }
 596   silc_list_start(engine->packet_pool);
 597
 598   return engine;
 599 }
 600
 601 /* Stop packet engine */
 602
 603 void silc_packet_engine_stop(SilcPacketEngine engine)
 604 {
 605   SilcPacket packet;
 606
 607   SILC_LOG_DEBUG(("Stopping packet engine"));
 608
 609   if (!engine)
 610     return;
 611
 612   /* Free packet free list */
 613   silc_list_start(engine->packet_pool);
 614   while ((packet = silc_list_get(engine->packet_pool))) {
 615     silc_buffer_purge(&packet->buffer);
 616     silc_free(packet);
 617   }
 618
 619   silc_hash_table_free(engine->contexts);
 620   silc_mutex_free(engine->lock);
 621   silc_free(engine);
 622 }
 623
 624 static const char * const packet_error[] = {
 625   "Cannot read from stream",
 626   "Cannot write to stream",
 627   "Packet MAC failed",
 628   "Packet decryption failed",
 629   "Unknown SID",
 630   "Packet is malformed",
 631   "System out of memory",
 632 };
 633
 634 /* Return packet error string */
 635
 636 const char *silc_packet_error_string(SilcPacketError error)
 637 {
 638   if (error < SILC_PACKET_ERR_READ || error > SILC_PACKET_ERR_NO_MEMORY)
 639     return "<invalid error code>";
 640   return packet_error[error];
 641 }
 642
 643 /* Return list of packet streams in the engine */
 644
 645 SilcDList silc_packet_engine_get_streams(SilcPacketEngine engine)
 646 {
 647   SilcDList list;
 648   SilcPacketStream ps;
 649
 650   list = silc_dlist_init();
 651   if (!list)
 652     return NULL;
 653
 654   silc_mutex_lock(engine->lock);
 655   silc_list_start(engine->streams);
 656   while ((ps = silc_list_get(engine->streams))) {
 657     silc_packet_stream_ref(ps);
 658     silc_dlist_add(list, ps);
 659   }
 660   silc_mutex_unlock(engine->lock);
 661
 662   return list;
 663 }
 664
 665 /* Free list returned by silc_packet_engine_get_streams */
 666
 667 void silc_packet_engine_free_streams_list(SilcDList streams)
 668 {
 669   SilcPacketStream ps;
 670
 671   silc_dlist_start(streams);
 672   while ((ps = silc_dlist_get(streams)))
 673     silc_packet_stream_unref(ps);
 674
 675   silc_dlist_uninit(streams);
 676 }
 677
 678 /* Create new packet stream */
 679
 680 SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
 681                                            SilcSchedule schedule,
 682                                            SilcStream stream)
 683 {
 684   SilcPacketStream ps;
 685   SilcBuffer inbuf;
 686   void *tmp;
 687
 688   SILC_LOG_DEBUG(("Creating new packet stream"));
 689
 690   if (!engine || !stream)
 691     return NULL;
 692
 693   ps = silc_calloc(1, sizeof(*ps));
 694   if (!ps)
 695     return NULL;
 696
 697   ps->stream = stream;
 698   silc_atomic_init32(&ps->refcnt, 1);
 699   silc_mutex_alloc(&ps->lock);
 700
 701   /* Allocate out buffer */
 702   tmp = silc_malloc(SILC_PACKET_DEFAULT_SIZE);
 703   if (!tmp) {
 704     silc_packet_stream_destroy(ps);
 705     return NULL;
 706   }
 707   silc_buffer_set(&ps->outbuf, tmp, SILC_PACKET_DEFAULT_SIZE);
 708   silc_buffer_reset(&ps->outbuf);
 709
 710   /* Initialize packet procesors list */
 711   ps->process = silc_dlist_init();
 712   if (!ps->process) {
 713     silc_packet_stream_destroy(ps);
 714     return NULL;
 715   }
 716
 717   silc_mutex_lock(engine->lock);
 718
 719   /* Add per scheduler context */
 720   if (!silc_hash_table_find(engine->contexts, schedule, NULL,
 721                             (void *)&ps->sc)) {
 722     ps->sc = silc_calloc(1, sizeof(*ps->sc));
 723     if (!ps->sc) {
 724       silc_mutex_unlock(engine->lock);
 725       silc_packet_stream_destroy(ps);
 726       return NULL;
 727     }
 728     ps->sc->engine = engine;
 729     ps->sc->schedule = schedule;
 730
 731     /* Allocate data input buffer */
 732     inbuf = silc_buffer_alloc(SILC_PACKET_DEFAULT_SIZE * 65);
 733     if (!inbuf) {
 734       silc_free(ps->sc);
 735       ps->sc = NULL;
 736       silc_mutex_unlock(engine->lock);
 737       silc_packet_stream_destroy(ps);
 738       return NULL;
 739     }
 740     silc_buffer_reset(inbuf);
 741
 742     ps->sc->inbufs = silc_dlist_init();
 743     if (!ps->sc->inbufs) {
 744       silc_buffer_free(inbuf);
 745       silc_free(ps->sc);
 746       ps->sc = NULL;
 747       silc_mutex_unlock(engine->lock);
 748       silc_packet_stream_destroy(ps);
 749       return NULL;
 750     }
 751     silc_dlist_add(ps->sc->inbufs, inbuf);
 752
 753     /* Add to per scheduler context hash table */
 754     if (!silc_hash_table_add(engine->contexts, schedule, ps->sc)) {
 755       silc_buffer_free(inbuf);
 756       silc_dlist_del(ps->sc->inbufs, inbuf);
 757       silc_free(ps->sc);
 758       ps->sc = NULL;
 759       silc_mutex_unlock(engine->lock);
 760       silc_packet_stream_destroy(ps);
 761       return NULL;
 762     }
 763   }
 764   ps->sc->stream_count++;
 765
 766   /* Add the packet stream to engine */
 767   silc_list_add(engine->streams, ps);
 768
 769   /* If this is UDP stream, allocate UDP remote stream hash table */
 770   if (!engine->udp_remote && silc_socket_stream_is_udp(stream, NULL))
 771     engine->udp_remote = silc_hash_table_alloc(0, silc_hash_string, NULL,
 772                                                silc_hash_string_compare, NULL,
 773                                                silc_packet_engine_hash_destr,
 774                                                NULL, TRUE);
 775
 776   silc_mutex_unlock(engine->lock);
 777
 778   /* Set IO notifier callback.  This schedules this stream for I/O. */
 779   if (!silc_stream_set_notifier(ps->stream, schedule,
 780                                 silc_packet_stream_io, ps)) {
 781     SILC_LOG_DEBUG(("Cannot set stream notifier for packet stream"));
 782     silc_packet_stream_destroy(ps);
 783     return NULL;
 784   }
 785
 786   SILC_LOG_DEBUG(("Created packet stream %p", ps));
 787
 788   return ps;
 789 }
 790
 791 /* Add new remote packet stream for UDP packet streams */
 792
 793 SilcPacketStream silc_packet_stream_add_remote(SilcPacketStream stream,
 794                                                const char *remote_ip,
 795                                                SilcUInt16 remote_port,
 796                                                SilcPacket packet)
 797 {
 798   SilcPacketEngine engine = stream->sc->engine;
 799   SilcPacketStream ps;
 800   char *tuple;
 801   void *tmp;
 802
 803   SILC_LOG_DEBUG(("Adding UDP remote %s:%d to packet stream %p",
 804                   remote_ip, remote_port, stream));
 805
 806   if (!stream || !remote_ip || !remote_port)
 807     return NULL;
 808
 809   if (!silc_socket_stream_is_udp(stream->stream, NULL)) {
 810     SILC_LOG_ERROR(("Stream is not UDP stream, cannot add remote IP"));
 811     return NULL;
 812   }
 813
 814   ps = silc_calloc(1, sizeof(*ps));
 815   if (!ps)
 816     return NULL;
 817   ps->sc = stream->sc;
 818
 819   silc_atomic_init32(&ps->refcnt, 1);
 820   silc_mutex_alloc(&ps->lock);
 821
 822   /* Set the UDP packet stream as underlaying stream */
 823   silc_packet_stream_ref(stream);
 824   ps->stream = (SilcStream)stream;
 825   ps->udp = TRUE;
 826
 827   /* Allocate out buffer */
 828   tmp = silc_malloc(SILC_PACKET_DEFAULT_SIZE);
 829   if (!tmp) {
 830     silc_packet_stream_destroy(ps);
 831     return NULL;
 832   }
 833   silc_buffer_set(&ps->outbuf, tmp, SILC_PACKET_DEFAULT_SIZE);
 834   silc_buffer_reset(&ps->outbuf);
 835
 836   /* Initialize packet procesors list */
 837   ps->process = silc_dlist_init();
 838   if (!ps->process) {
 839     silc_packet_stream_destroy(ps);
 840     return NULL;
 841   }
 842
 843   /* Add to engine with this IP and port pair */
 844   tuple = silc_format("%d%s", remote_port, remote_ip);
 845   silc_mutex_lock(engine->lock);
 846   if (!tuple || !silc_hash_table_add(engine->udp_remote, tuple, ps)) {
 847     silc_mutex_unlock(engine->lock);
 848     silc_packet_stream_destroy(ps);
 849     return NULL;
 850   }
 851   silc_mutex_unlock(engine->lock);
 852
 853   /* Save remote IP and port pair */
 854   ps->remote_udp = silc_calloc(1, sizeof(*ps->remote_udp));
 855   if (!ps->remote_udp) {
 856     silc_packet_stream_destroy(ps);
 857     return NULL;
 858   }
 859   ps->remote_udp->remote_port = remote_port;
 860   ps->remote_udp->remote_ip = strdup(remote_ip);
 861   if (!ps->remote_udp->remote_ip) {
 862     silc_packet_stream_destroy(ps);
 863     return NULL;
 864   }
 865
 866   if (packet) {
 867     /* Inject packet to the new stream */
 868     packet->stream = ps;
 869     silc_packet_stream_ref(ps);
 870     silc_schedule_task_add_timeout(silc_stream_get_schedule(stream->stream),
 871                                    silc_packet_stream_inject_packet, packet,
 872                                    0, 0);
 873   }
 874
 875   return ps;
 876 }
 877
 878 /* Destroy packet stream */
 879
 880 void silc_packet_stream_destroy(SilcPacketStream stream)
 881 {
 882   SilcPacketEngine engine;
 883
 884   if (!stream)
 885     return;
 886
 887   if (silc_atomic_sub_int32(&stream->refcnt, 1) > 0) {
 888     if (stream->destroyed)
 889       return;
 890     stream->destroyed = TRUE;
 891
 892     SILC_LOG_DEBUG(("Marking packet stream %p destroyed", stream));
 893
 894     /* Close the underlaying stream */
 895     if (!stream->udp && stream->stream)
 896       silc_stream_close(stream->stream);
 897     return;
 898   }
 899
 900   SILC_LOG_DEBUG(("Destroying packet stream %p", stream));
 901
 902   if (!stream->udp) {
 903     /* Delete from engine */
 904     if (stream->sc) {
 905       engine = stream->sc->engine;
 906       silc_mutex_lock(engine->lock);
 907       silc_list_del(engine->streams, stream);
 908
 909       /* Remove per scheduler context, if it is not used anymore */
 910       stream->sc->stream_count--;
 911       if (!stream->sc->stream_count)
 912         silc_hash_table_del(engine->contexts, stream->sc->schedule);
 913
 914       silc_mutex_unlock(engine->lock);
 915     }
 916
 917     /* Destroy the underlaying stream */
 918     if (stream->stream)
 919       silc_stream_destroy(stream->stream);
 920   } else {
 921     /* Delete from UDP remote hash table */
 922     char tuple[64];
 923     engine = stream->sc->engine;
 924     silc_snprintf(tuple, sizeof(tuple), "%d%s",
 925                   stream->remote_udp->remote_port,
 926                   stream->remote_udp->remote_ip);
 927     silc_mutex_lock(engine->lock);
 928     silc_hash_table_del(engine->udp_remote, tuple);
 929     silc_mutex_unlock(engine->lock);
 930
 931     silc_free(stream->remote_udp->remote_ip);
 932     silc_free(stream->remote_udp);
 933
 934     /* Unreference the underlaying packet stream */
 935     silc_packet_stream_unref((SilcPacketStream)stream->stream);
 936   }
 937
 938   /* Clear and free buffers */
 939   silc_buffer_clear(&stream->outbuf);
 940   silc_buffer_purge(&stream->outbuf);
 941
 942   if (stream->process) {
 943     SilcPacketProcess p;
 944     silc_dlist_start(stream->process);
 945     while ((p = silc_dlist_get(stream->process))) {
 946       silc_free(p->types);
 947       silc_free(p);
 948       silc_dlist_del(stream->process, p);
 949     }
 950     silc_dlist_uninit(stream->process);
 951   }
 952
 953   /* Destroy ciphers and HMACs */
 954   if (stream->send_key[0])
 955     silc_cipher_free(stream->send_key[0]);
 956   if (stream->receive_key[0])
 957     silc_cipher_free(stream->receive_key[0]);
 958   if (stream->send_hmac[0])
 959     silc_hmac_free(stream->send_hmac[0]);
 960   if (stream->receive_hmac[0])
 961     silc_hmac_free(stream->receive_hmac[0]);
 962   if (stream->send_key[1])
 963     silc_cipher_free(stream->send_key[1]);
 964   if (stream->receive_key[1])
 965     silc_cipher_free(stream->receive_key[1]);
 966   if (stream->send_hmac[1])
 967     silc_hmac_free(stream->send_hmac[1]);
 968   if (stream->receive_hmac[1])
 969     silc_hmac_free(stream->receive_hmac[1]);
 970
 971   /* Free IDs */
 972   silc_free(stream->src_id);
 973   silc_free(stream->dst_id);
 974
 975   silc_atomic_uninit32(&stream->refcnt);
 976   silc_mutex_free(stream->lock);
 977   silc_free(stream);
 978 }
 979
 980 /* Return TRUE if the stream is valid */
 981
 982 SilcBool silc_packet_stream_is_valid(SilcPacketStream stream)
 983 {
 984   return stream->destroyed == FALSE;
 985 }
 986
 987 /* Marks as router stream */
 988
 989 void silc_packet_stream_set_router(SilcPacketStream stream)
 990 {
 991   stream->is_router = TRUE;
 992 }
 993
 994 /* Mark to include IV in ciphertext */
 995
 996 void silc_packet_stream_set_iv_included(SilcPacketStream stream)
 997 {
 998   stream->iv_included = TRUE;
 999 }
1000
1001 /* Links `callbacks' to `stream' for specified packet types */
1002
1003 static SilcBool silc_packet_stream_link_va(SilcPacketStream stream,
1004                                            const SilcPacketCallbacks *callbacks,
1005                                            void *callback_context,
1006                                            int priority, va_list ap)
1007 {
1008   SilcPacketProcess p, e;
1009   SilcInt32 packet_type;
1010   int i;
1011
1012   SILC_LOG_DEBUG(("Linking callbacks %p to stream %p", callbacks, stream));
1013
1014   if (!callbacks)
1015     return FALSE;
1016   if (!callbacks->packet_receive)
1017     return FALSE;
1018
1019   p = silc_calloc(1, sizeof(*p));
1020   if (!p)
1021     return FALSE;
1022
1023   p->priority = priority;
1024   p->callbacks = callbacks;
1025   p->callback_context = callback_context;
1026
1027   silc_mutex_lock(stream->lock);
1028
1029   if (!stream->process) {
1030     stream->process = silc_dlist_init();
1031     if (!stream->process) {
1032       silc_mutex_unlock(stream->lock);
1033       silc_free(p);
1034       return FALSE;
1035     }
1036   }
1037
1038   /* According to priority set the procesor to correct position.  First
1039      entry has the highest priority */
1040   silc_dlist_start(stream->process);
1041   while ((e = silc_dlist_get(stream->process)) != SILC_LIST_END) {
1042     if (p->priority > e->priority) {
1043       silc_dlist_insert(stream->process, p);
1044       break;
1045     }
1046   }
1047   if (!e)
1048     silc_dlist_add(stream->process, p);
1049
1050   /* Get packet types to process */
1051   i = 1;
1052   while (1) {
1053     packet_type = va_arg(ap, SilcInt32);
1054
1055     if (packet_type == SILC_PACKET_ANY)
1056       break;
1057
1058     if (packet_type == -1)
1059       break;
1060
1061     p->types = silc_realloc(p->types, sizeof(*p->types) * (i + 1));
1062     if (!p->types) {
1063       silc_mutex_unlock(stream->lock);
1064       return FALSE;
1065     }
1066
1067     p->types[i - 1] = (SilcPacketType)packet_type;
1068     i++;
1069   }
1070   if (p->types)
1071     p->types[i - 1] = 0;
1072
1073   silc_mutex_unlock(stream->lock);
1074
1075   silc_packet_stream_ref(stream);
1076
1077   return TRUE;
1078 }
1079
1080 /* Links `callbacks' to `stream' for specified packet types */
1081
1082 SilcBool silc_packet_stream_link(SilcPacketStream stream,
1083                                  const SilcPacketCallbacks *callbacks,
1084                                  void *callback_context,
1085                                  int priority, ...)
1086 {
1087   va_list ap;
1088   SilcBool ret;
1089
1090   va_start(ap, priority);
1091   ret = silc_packet_stream_link_va(stream, callbacks, callback_context,
1092                                    priority, ap);
1093   va_end(ap);
1094
1095   return ret;
1096 }
1097
1098 /* Unlinks `callbacks' from `stream'. */
1099
1100 void silc_packet_stream_unlink(SilcPacketStream stream,
1101                                const SilcPacketCallbacks *callbacks,
1102                                void *callback_context)
1103 {
1104   SilcPacketProcess p;
1105
1106   SILC_LOG_DEBUG(("Unlinking callbacks %p from stream %p",
1107                   callbacks, stream));
1108
1109   silc_mutex_lock(stream->lock);
1110
1111   silc_dlist_start(stream->process);
1112   while ((p = silc_dlist_get(stream->process)) != SILC_LIST_END)
1113     if (p->callbacks == callbacks &&
1114         p->callback_context == callback_context) {
1115       silc_dlist_del(stream->process, p);
1116       silc_free(p->types);
1117       silc_free(p);
1118       break;
1119     }
1120
1121   if (!silc_dlist_count(stream->process)) {
1122     silc_dlist_uninit(stream->process);
1123     stream->process = NULL;
1124   }
1125
1126   silc_mutex_unlock(stream->lock);
1127
1128   silc_packet_stream_unref(stream);
1129 }
1130
1131 /* Returns TRUE if stream is UDP stream */
1132
1133 SilcBool silc_packet_stream_is_udp(SilcPacketStream stream)
1134 {
1135   return stream->udp || silc_socket_stream_is_udp(stream->stream, NULL);
1136 }
1137
1138 /* Return packet sender IP and port for UDP packet stream */
1139
1140 SilcBool silc_packet_get_sender(SilcPacket packet,
1141                                 const char **sender_ip,
1142                                 SilcUInt16 *sender_port)
1143 {
1144   if (!packet->stream->remote_udp)
1145     return FALSE;
1146
1147   *sender_ip = packet->stream->remote_udp->remote_ip;
1148   *sender_port = packet->stream->remote_udp->remote_port;
1149
1150   return TRUE;
1151 }
1152
1153 /* Reference packet stream */
1154
1155 void silc_packet_stream_ref(SilcPacketStream stream)
1156 {
1157   silc_atomic_add_int32(&stream->refcnt, 1);
1158   SILC_LOG_DEBUG(("Stream %p, refcnt %d->%d", stream,
1159                   silc_atomic_get_int32(&stream->refcnt) - 1,
1160                   silc_atomic_get_int32(&stream->refcnt)));
1161 }
1162
1163 /* Unreference packet stream */
1164
1165 void silc_packet_stream_unref(SilcPacketStream stream)
1166 {
1167   SILC_LOG_DEBUG(("Stream %p, refcnt %d->%d", stream,
1168                   silc_atomic_get_int32(&stream->refcnt),
1169                   silc_atomic_get_int32(&stream->refcnt) - 1));
1170   if (silc_atomic_sub_int32(&stream->refcnt, 1) > 0)
1171     return;
1172   silc_atomic_add_int32(&stream->refcnt, 1);
1173   silc_packet_stream_destroy(stream);
1174 }
1175
1176 /* Return engine */
1177
1178 SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream)
1179 {
1180   return stream->sc->engine;
1181 }
1182
1183 /* Set application context for packet stream */
1184
1185 void silc_packet_set_context(SilcPacketStream stream, void *stream_context)
1186 {
1187   silc_mutex_lock(stream->lock);
1188   stream->stream_context = stream_context;
1189   silc_mutex_unlock(stream->lock);
1190 }
1191
1192 /* Return application context from packet stream */
1193
1194 void *silc_packet_get_context(SilcPacketStream stream)
1195 {
1196   void *context;
1197   silc_mutex_lock(stream->lock);
1198   context = stream->stream_context;
1199   silc_mutex_unlock(stream->lock);
1200   return context;
1201 }
1202
1203 /* Change underlaying stream */
1204
1205 void silc_packet_stream_set_stream(SilcPacketStream ps,
1206                                    SilcStream stream)
1207 {
1208   if (ps->stream)
1209     silc_stream_set_notifier(ps->stream, ps->sc->schedule, NULL, NULL);
1210   ps->stream = stream;
1211   silc_stream_set_notifier(ps->stream, ps->sc->schedule, silc_packet_stream_io,
1212                            ps);
1213 }
1214
1215 /* Return underlaying stream */
1216
1217 SilcStream silc_packet_stream_get_stream(SilcPacketStream stream)
1218 {
1219   return stream->stream;
1220 }
1221
1222 /* Set keys. */
1223
1224 SilcBool silc_packet_set_keys(SilcPacketStream stream, SilcCipher send_key,
1225                               SilcCipher receive_key, SilcHmac send_hmac,
1226                               SilcHmac receive_hmac, SilcBool rekey)
1227 {
1228   SILC_LOG_DEBUG(("Setting new keys to packet stream %p", stream));
1229
1230   /* If doing rekey, send REKEY_DONE packet */
1231   if (rekey) {
1232     /* This will take stream lock. */
1233     if (!silc_packet_send_raw(stream, SILC_PACKET_REKEY_DONE, 0,
1234                               stream->src_id_type, stream->src_id,
1235                               stream->src_id_len, stream->dst_id_type,
1236                               stream->dst_id, stream->dst_id_len,
1237                               NULL, 0, stream->send_key[0],
1238                               stream->send_hmac[0]))
1239       return FALSE;
1240
1241     /* Write the packet to the stream */
1242     if (!silc_packet_stream_write(stream, TRUE))
1243       return FALSE;
1244   } else {
1245     silc_mutex_lock(stream->lock);
1246   }
1247
1248   /* In case IV Included is set, save the old keys */
1249   if (stream->iv_included) {
1250     if (stream->send_key[1] && send_key) {
1251       silc_cipher_free(stream->send_key[1]);
1252       stream->send_key[1] = stream->send_key[0];
1253     }
1254     if (stream->receive_key[1] && receive_key) {
1255       silc_cipher_free(stream->receive_key[1]);
1256       stream->receive_key[1] = stream->receive_key[0];
1257     }
1258     if (stream->send_hmac[1] && send_hmac) {
1259       silc_hmac_free(stream->send_hmac[1]);
1260       stream->send_hmac[1] = stream->send_hmac[0];
1261     }
1262     if (stream->receive_hmac[1] && receive_hmac) {
1263       silc_hmac_free(stream->receive_hmac[1]);
1264       stream->receive_hmac[1] = stream->receive_hmac[0];
1265     }
1266   } else {
1267     if (stream->send_key[0] && send_key)
1268       silc_cipher_free(stream->send_key[0]);
1269     if (stream->receive_key[0] && receive_key)
1270       silc_cipher_free(stream->receive_key[0]);
1271     if (stream->send_hmac[0] && send_hmac)
1272       silc_hmac_free(stream->send_hmac[0]);
1273     if (stream->receive_hmac[0] && receive_hmac)
1274       silc_hmac_free(stream->receive_hmac[0]);
1275   }
1276
1277   /* Set keys */
1278   if (send_key)
1279     stream->send_key[0] = send_key;
1280   if (receive_key)
1281     stream->receive_key[0] = receive_key;
1282   if (send_hmac)
1283     stream->send_hmac[0] = send_hmac;
1284   if (receive_hmac)
1285     stream->receive_hmac[0] = receive_hmac;
1286
1287   silc_mutex_unlock(stream->lock);
1288   return TRUE;
1289 }
1290
1291 /* Return current ciphers from packet stream */
1292
1293 SilcBool silc_packet_get_keys(SilcPacketStream stream,
1294                               SilcCipher *send_key,
1295                               SilcCipher *receive_key,
1296                               SilcHmac *send_hmac,
1297                               SilcHmac *receive_hmac)
1298 {
1299   if (!stream->send_key[0] && !stream->receive_key[0] &&
1300       !stream->send_hmac[0] && !stream->receive_hmac[0])
1301     return FALSE;
1302
1303   silc_mutex_lock(stream->lock);
1304
1305   if (send_key)
1306     *send_key = stream->send_key[0];
1307   if (receive_key)
1308     *receive_key = stream->receive_key[0];
1309   if (send_hmac)
1310     *send_hmac = stream->send_hmac[0];
1311   if (receive_hmac)
1312     *receive_hmac = stream->receive_hmac[0];
1313
1314   silc_mutex_unlock(stream->lock);
1315
1316   return TRUE;
1317 }
1318
1319 /* Set SILC IDs to packet stream */
1320
1321 SilcBool silc_packet_set_ids(SilcPacketStream stream,
1322                              SilcIdType src_id_type, const void *src_id,
1323                              SilcIdType dst_id_type, const void *dst_id)
1324 {
1325   SilcUInt32 len;
1326   unsigned char tmp[32];
1327   void *tmp_id;
1328
1329   if (!src_id && !dst_id)
1330     return FALSE;
1331
1332   silc_mutex_lock(stream->lock);
1333
1334   if (src_id) {
1335     SILC_LOG_DEBUG(("Setting source ID to packet stream %p", stream));
1336
1337     if (!silc_id_id2str(src_id, src_id_type, tmp, sizeof(tmp), &len)) {
1338       silc_mutex_unlock(stream->lock);
1339       return FALSE;
1340     }
1341     tmp_id = silc_memdup(tmp, len);
1342     if (!tmp_id) {
1343       silc_mutex_unlock(stream->lock);
1344       return FALSE;
1345     }
1346     silc_free(stream->src_id);
1347     stream->src_id = tmp_id;
1348     stream->src_id_type = src_id_type;
1349     stream->src_id_len = len;
1350   }
1351
1352   if (dst_id) {
1353     SILC_LOG_DEBUG(("Setting destination ID to packet stream %p", stream));
1354
1355     if (!silc_id_id2str(dst_id, dst_id_type, tmp, sizeof(tmp), &len)) {
1356       silc_mutex_unlock(stream->lock);
1357       return FALSE;
1358     }
1359     tmp_id = silc_memdup(tmp, len);
1360     if (!tmp_id) {
1361       silc_mutex_unlock(stream->lock);
1362       return FALSE;
1363     }
1364     silc_free(stream->dst_id);
1365     stream->dst_id = tmp_id;
1366     stream->dst_id_type = dst_id_type;
1367     stream->dst_id_len = len;
1368   }
1369
1370   silc_mutex_unlock(stream->lock);
1371
1372   return TRUE;
1373 }
1374
1375 /* Return IDs from the packet stream */
1376
1377 SilcBool silc_packet_get_ids(SilcPacketStream stream,
1378                              SilcBool *src_id_set, SilcID *src_id,
1379                              SilcBool *dst_id_set, SilcID *dst_id)
1380 {
1381   if (src_id && stream->src_id)
1382     if (!silc_id_str2id2(stream->src_id, stream->src_id_len,
1383                          stream->src_id_type, src_id))
1384       return FALSE;
1385
1386   if (stream->src_id && src_id_set)
1387     *src_id_set = TRUE;
1388
1389   if (dst_id && stream->dst_id)
1390     if (!silc_id_str2id2(stream->dst_id, stream->dst_id_len,
1391                          stream->dst_id_type, dst_id))
1392       return FALSE;
1393
1394   if (stream->dst_id && dst_id_set)
1395     *dst_id_set = TRUE;
1396
1397   return TRUE;
1398 }
1399
1400 /* Adds Security ID (SID) */
1401
1402 SilcBool silc_packet_set_sid(SilcPacketStream stream, SilcUInt8 sid)
1403 {
1404   if (!stream->iv_included)
1405     return FALSE;
1406
1407   SILC_LOG_DEBUG(("Set packet stream %p SID to %d", stream, sid));
1408
1409   stream->sid = sid;
1410   return TRUE;
1411 }
1412
1413 /* Free packet */
1414
1415 void silc_packet_free(SilcPacket packet)
1416 {
1417   SilcPacketStream stream = packet->stream;
1418
1419   SILC_LOG_DEBUG(("Freeing packet %p", packet));
1420
1421   /* Check for double free */
1422   SILC_ASSERT(packet->stream != NULL);
1423
1424   packet->stream = NULL;
1425   packet->src_id = packet->dst_id = NULL;
1426   silc_buffer_reset(&packet->buffer);
1427
1428   silc_mutex_lock(stream->sc->engine->lock);
1429
1430   /* Put the packet back to freelist */
1431   silc_list_add(stream->sc->engine->packet_pool, packet);
1432   if (silc_list_count(stream->sc->engine->packet_pool) == 1)
1433     silc_list_start(stream->sc->engine->packet_pool);
1434
1435   silc_mutex_unlock(stream->sc->engine->lock);
1436 }
1437
1438 /****************************** Packet Sending ******************************/
1439
1440 /* Prepare outgoing data buffer for packet sending.  Returns the
1441    pointer to that buffer into the `packet'. */
1442
1443 static inline SilcBool silc_packet_send_prepare(SilcPacketStream stream,
1444                                                 SilcUInt32 totlen,
1445                                                 SilcHmac hmac,
1446                                                 SilcBuffer packet)
1447 {
1448   unsigned char *oldptr;
1449   unsigned int mac_len = hmac ? silc_hmac_len(hmac) : 0;
1450
1451   totlen += mac_len;
1452
1453   /* Allocate more space if needed */
1454   if (silc_unlikely(silc_buffer_taillen(&stream->outbuf) < totlen)) {
1455     if (!silc_buffer_realloc(&stream->outbuf,
1456                              silc_buffer_truelen(&stream->outbuf) + totlen))
1457       return FALSE;
1458   }
1459
1460   /* Pull data area for the new packet, and return pointer to the start of
1461      the data area and save the pointer in to the `packet'.  MAC is pulled
1462      later after it's computed. */
1463   oldptr = silc_buffer_pull_tail(&stream->outbuf, totlen);
1464   silc_buffer_set(packet, oldptr, totlen);
1465   silc_buffer_push_tail(packet, mac_len);
1466
1467   return TRUE;
1468 }
1469
1470 /* Increments counter when encrypting in counter mode. */
1471
1472 static inline void silc_packet_send_ctr_increment(SilcPacketStream stream,
1473                                                   SilcCipher cipher,
1474                                                   unsigned char *ret_iv)
1475 {
1476   unsigned char *iv = silc_cipher_get_iv(cipher);
1477   SilcUInt32 pc1, pc2;
1478
1479   /* Reset block counter */
1480   memset(iv + 12, 0, 4);
1481
1482   /* If IV Included flag, return the 64-bit IV for inclusion in packet */
1483   if (stream->iv_included) {
1484     /* Get new nonce */
1485     ret_iv[0] = silc_rng_get_byte_fast(stream->sc->engine->rng);
1486     ret_iv[1] = ret_iv[0] + iv[4];
1487     ret_iv[2] = ret_iv[0] ^ ret_iv[1];
1488     ret_iv[3] = ret_iv[0] + ret_iv[2];
1489
1490     /* Increment 32-bit packet counter */
1491     SILC_GET32_MSB(pc1, iv + 8);
1492     pc1++;
1493     SILC_PUT32_MSB(pc1, ret_iv + 4);
1494
1495     SILC_LOG_HEXDUMP(("IV"), ret_iv, 8);
1496
1497     /* Set new nonce to counter block */
1498     memcpy(iv + 4, ret_iv, 8);
1499   } else {
1500     /* Increment 64-bit packet counter */
1501     SILC_GET32_MSB(pc1, iv + 4);
1502     SILC_GET32_MSB(pc2, iv + 8);
1503     if (++pc2 == 0)
1504       ++pc1;
1505     SILC_PUT32_MSB(pc1, iv + 4);
1506     SILC_PUT32_MSB(pc2, iv + 8);
1507   }
1508
1509   SILC_LOG_HEXDUMP(("Counter Block"), iv, 16);
1510 }
1511
1512 /* Internal routine to assemble outgoing packet.  Assembles and encryptes
1513    the packet.  The silc_packet_stream_write needs to be called to send it
1514    after this returns TRUE. */
1515
1516 static inline SilcBool silc_packet_send_raw(SilcPacketStream stream,
1517                                             SilcPacketType type,
1518                                             SilcPacketFlags flags,
1519                                             SilcIdType src_id_type,
1520                                             unsigned char *src_id,
1521                                             SilcUInt32 src_id_len,
1522                                             SilcIdType dst_id_type,
1523                                             unsigned char *dst_id,
1524                                             SilcUInt32 dst_id_len,
1525                                             const unsigned char *data,
1526                                             SilcUInt32 data_len,
1527                                             SilcCipher cipher,
1528                                             SilcHmac hmac)
1529 {
1530   unsigned char tmppad[SILC_PACKET_MAX_PADLEN], iv[33], psn[4];
1531   int block_len = (cipher ? silc_cipher_get_block_len(cipher) : 0);
1532   int i, enclen, truelen, padlen = 0, ivlen = 0, psnlen = 0;
1533   SilcBool ctr;
1534   SilcBufferStruct packet;
1535
1536   SILC_LOG_DEBUG(("Sending packet %s (%d) flags %d, src %d dst %d, "
1537                   "data len %d", silc_get_packet_name(type), stream->send_psn,
1538                   flags, src_id_type, dst_id_type, data_len));
1539
1540   /* Get the true length of the packet. This is saved as payload length
1541      into the packet header.  This does not include the length of the
1542      padding. */
1543   data_len = SILC_PACKET_DATALEN(data_len, (SILC_PACKET_HEADER_LEN +
1544                                             src_id_len + dst_id_len));
1545   enclen = truelen = (data_len + SILC_PACKET_HEADER_LEN +
1546                       src_id_len + dst_id_len);
1547
1548   /* If using CTR mode, increment the counter */
1549   ctr = (cipher && silc_cipher_get_mode(cipher) == SILC_CIPHER_MODE_CTR);
1550   if (ctr) {
1551     silc_packet_send_ctr_increment(stream, cipher, iv + 1);
1552
1553     /* If IV is included, the SID, IV and sequence number is added to packet */
1554     if (stream->iv_included && cipher) {
1555       psnlen = sizeof(psn);
1556       ivlen = 8 + 1;
1557       iv[0] = stream->sid;
1558     }
1559   } else {
1560     /* If IV is included, the SID, IV and sequence number is added to packet */
1561     if (stream->iv_included && cipher) {
1562       psnlen = sizeof(psn);
1563       ivlen = block_len + 1;
1564       iv[0] = stream->sid;
1565       memcpy(iv + 1, silc_cipher_get_iv(cipher), block_len);
1566     }
1567   }
1568
1569   /* We automatically figure out the packet structure from the packet
1570      type and flags, and calculate correct length.  Private messages with
1571      private keys and channel messages are special packets as their
1572      payload is encrypted already. */
1573   if (type == SILC_PACKET_PRIVATE_MESSAGE &&
1574       flags & SILC_PACKET_FLAG_PRIVMSG_KEY) {
1575     /* Padding is calculated from header + IDs */
1576     if (!ctr)
1577       SILC_PACKET_PADLEN((SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
1578                           psnlen), block_len, padlen);
1579
1580     /* Length to encrypt, header + IDs + padding. */
1581     enclen = (SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
1582               padlen + psnlen);
1583
1584   } else if (type == SILC_PACKET_CHANNEL_MESSAGE) {
1585     if (stream->sc->engine->local_is_router && stream->is_router) {
1586       /* Channel messages between routers are encrypted as normal packets.
1587          Padding is calculated from true length of the packet. */
1588       if (!ctr)
1589         SILC_PACKET_PADLEN(truelen + psnlen, block_len, padlen);
1590
1591       enclen += padlen + psnlen;
1592     } else {
1593       /* Padding is calculated from header + IDs */
1594       if (!ctr)
1595         SILC_PACKET_PADLEN((SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
1596                             psnlen), block_len, padlen);
1597
1598       /* Length to encrypt, header + IDs + padding. */
1599       enclen = (SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
1600                 padlen + psnlen);
1601     }
1602   } else {
1603     /* Padding is calculated from true length of the packet */
1604     if (flags & SILC_PACKET_FLAG_LONG_PAD)
1605       SILC_PACKET_PADLEN_MAX(truelen + psnlen, block_len, padlen);
1606     else if (!ctr)
1607       SILC_PACKET_PADLEN(truelen + psnlen, block_len, padlen);
1608
1609     enclen += padlen + psnlen;
1610   }
1611
1612   /* Remove implementation specific flags */
1613   flags &= ~(SILC_PACKET_FLAG_LONG_PAD);
1614
1615   /* Get random padding */
1616   for (i = 0; i < padlen; i++) tmppad[i] =
1617     silc_rng_get_byte_fast(stream->sc->engine->rng);
1618
1619   silc_mutex_lock(stream->lock);
1620
1621   /* Get packet pointer from the outgoing buffer */
1622   if (silc_unlikely(!silc_packet_send_prepare(stream, truelen + padlen + ivlen
1623                                               + psnlen, hmac, &packet))) {
1624     silc_mutex_unlock(stream->lock);
1625     return FALSE;
1626   }
1627
1628   SILC_PUT32_MSB(stream->send_psn, psn);
1629
1630   /* Create the packet.  This creates the SILC header, adds padding, and
1631      the actual packet data. */
1632   i = silc_buffer_format(&packet,
1633                          SILC_STR_DATA(iv, ivlen),
1634                          SILC_STR_DATA(psn, psnlen),
1635                          SILC_STR_UI_SHORT(truelen),
1636                          SILC_STR_UI_CHAR(flags),
1637                          SILC_STR_UI_CHAR(type),
1638                          SILC_STR_UI_CHAR(padlen),
1639                          SILC_STR_UI_CHAR(0),
1640                          SILC_STR_UI_CHAR(src_id_len),
1641                          SILC_STR_UI_CHAR(dst_id_len),
1642                          SILC_STR_UI_CHAR(src_id_type),
1643                          SILC_STR_DATA(src_id, src_id_len),
1644                          SILC_STR_UI_CHAR(dst_id_type),
1645                          SILC_STR_DATA(dst_id, dst_id_len),
1646                          SILC_STR_DATA(tmppad, padlen),
1647                          SILC_STR_DATA(data, data_len),
1648                          SILC_STR_END);
1649   if (silc_unlikely(i < 0)) {
1650     silc_mutex_unlock(stream->lock);
1651     return FALSE;
1652   }
1653
1654   SILC_LOG_HEXDUMP(("Assembled packet, len %d", silc_buffer_len(&packet)),
1655                    silc_buffer_data(&packet), silc_buffer_len(&packet));
1656
1657   /* Encrypt the packet */
1658   if (silc_likely(cipher)) {
1659     SILC_LOG_DEBUG(("Encrypting packet"));
1660     silc_cipher_set_iv(cipher, NULL);
1661     if (silc_unlikely(!silc_cipher_encrypt(cipher, packet.data + ivlen,
1662                                            packet.data + ivlen, enclen,
1663                                            NULL))) {
1664       SILC_LOG_ERROR(("Packet encryption failed"));
1665       silc_mutex_unlock(stream->lock);
1666       return FALSE;
1667     }
1668   }
1669
1670   /* Compute HMAC */
1671   if (silc_likely(hmac)) {
1672     SilcUInt32 mac_len;
1673
1674     /* MAC is computed from the entire encrypted packet data, and put
1675        to the end of the packet. */
1676     silc_hmac_init(hmac);
1677     silc_hmac_update(hmac, psn, sizeof(psn));
1678     silc_hmac_update(hmac, packet.data, silc_buffer_len(&packet));
1679     silc_hmac_final(hmac, packet.tail, &mac_len);
1680     silc_buffer_pull_tail(&packet, mac_len);
1681     stream->send_psn++;
1682   }
1683
1684   return TRUE;
1685 }
1686
1687 /* Sends a packet */
1688
1689 SilcBool silc_packet_send(SilcPacketStream stream,
1690                           SilcPacketType type, SilcPacketFlags flags,
1691                           const unsigned char *data, SilcUInt32 data_len)
1692 {
1693   SilcBool ret;
1694
1695   ret = silc_packet_send_raw(stream, type, flags,
1696                              stream->src_id_type,
1697                              stream->src_id,
1698                              stream->src_id_len,
1699                              stream->dst_id_type,
1700                              stream->dst_id,
1701                              stream->dst_id_len,
1702                              data, data_len,
1703                              stream->send_key[0],
1704                              stream->send_hmac[0]);
1705
1706   /* Write the packet to the stream */
1707   return ret ? silc_packet_stream_write(stream, FALSE) : FALSE;
1708 }
1709
1710 /* Sends a packet, extended routine */
1711
1712 SilcBool silc_packet_send_ext(SilcPacketStream stream,
1713                               SilcPacketType type, SilcPacketFlags flags,
1714                               SilcIdType src_id_type, void *src_id,
1715                               SilcIdType dst_id_type, void *dst_id,
1716                               const unsigned char *data, SilcUInt32 data_len,
1717                               SilcCipher cipher, SilcHmac hmac)
1718 {
1719   unsigned char src_id_data[32], dst_id_data[32];
1720   SilcUInt32 src_id_len, dst_id_len;
1721   SilcBool ret;
1722
1723   if (src_id)
1724     if (!silc_id_id2str(src_id, src_id_type, src_id_data,
1725                         sizeof(src_id_data), &src_id_len))
1726       return FALSE;
1727   if (dst_id)
1728     if (!silc_id_id2str(dst_id, dst_id_type, dst_id_data,
1729                         sizeof(dst_id_data), &dst_id_len))
1730       return FALSE;
1731
1732   ret = silc_packet_send_raw(stream, type, flags,
1733                              src_id ? src_id_type : stream->src_id_type,
1734                              src_id ? src_id_data : stream->src_id,
1735                              src_id ? src_id_len : stream->src_id_len,
1736                              dst_id ? dst_id_type : stream->dst_id_type,
1737                              dst_id ? dst_id_data : stream->dst_id,
1738                              dst_id ? dst_id_len : stream->dst_id_len,
1739                              data, data_len,
1740                              cipher ? cipher : stream->send_key[0],
1741                              hmac ? hmac : stream->send_hmac[0]);
1742
1743   /* Write the packet to the stream */
1744   return ret ? silc_packet_stream_write(stream, FALSE) : FALSE;
1745 }
1746
1747 /* Sends packet after formatting the arguments to buffer */
1748
1749 SilcBool silc_packet_send_va(SilcPacketStream stream,
1750                              SilcPacketType type, SilcPacketFlags flags, ...)
1751 {
1752   SilcBufferStruct buf;
1753   SilcBool ret;
1754   va_list va;
1755
1756   va_start(va, flags);
1757
1758   memset(&buf, 0, sizeof(buf));
1759   if (silc_buffer_format_vp(&buf, va) < 0) {
1760     va_end(va);
1761     return FALSE;
1762   }
1763
1764   ret = silc_packet_send(stream, type, flags, silc_buffer_data(&buf),
1765                          silc_buffer_len(&buf));
1766
1767   silc_buffer_purge(&buf);
1768   va_end(va);
1769
1770   return ret;
1771 }
1772
1773 /* Sends packet after formatting the arguments to buffer, extended routine */
1774
1775 SilcBool silc_packet_send_va_ext(SilcPacketStream stream,
1776                                  SilcPacketType type, SilcPacketFlags flags,
1777                                  SilcIdType src_id_type, void *src_id,
1778                                  SilcIdType dst_id_type, void *dst_id,
1779                                  SilcCipher cipher, SilcHmac hmac, ...)
1780 {
1781   SilcBufferStruct buf;
1782   SilcBool ret;
1783   va_list va;
1784
1785   va_start(va, hmac);
1786
1787   memset(&buf, 0, sizeof(buf));
1788   if (silc_buffer_format_vp(&buf, va) < 0) {
1789     va_end(va);
1790     return FALSE;
1791   }
1792
1793   ret = silc_packet_send_ext(stream, type, flags, src_id_type, src_id,
1794                              dst_id_type, dst_id, silc_buffer_data(&buf),
1795                              silc_buffer_len(&buf), cipher, hmac);
1796
1797   silc_buffer_purge(&buf);
1798   va_end(va);
1799
1800   return TRUE;
1801 }
1802
1803 /***************************** Packet Receiving *****************************/
1804
1805 /* Checks MAC in the packet. Returns TRUE if MAC is Ok. */
1806
1807 static inline SilcBool silc_packet_check_mac(SilcHmac hmac,
1808                                              const unsigned char *data,
1809                                              SilcUInt32 data_len,
1810                                              const unsigned char *packet_mac,
1811                                              const unsigned char *packet_seq,
1812                                              SilcUInt32 sequence)
1813 {
1814   /* Check MAC */
1815   if (silc_likely(hmac)) {
1816     unsigned char mac[32], psn[4];
1817     SilcUInt32 mac_len;
1818
1819     SILC_LOG_DEBUG(("Verifying MAC"));
1820
1821     /* Compute HMAC of packet */
1822     silc_hmac_init(hmac);
1823
1824     if (!packet_seq) {
1825       SILC_PUT32_MSB(sequence, psn);
1826       silc_hmac_update(hmac, psn, 4);
1827     } else
1828       silc_hmac_update(hmac, packet_seq, 4);
1829
1830     silc_hmac_update(hmac, data, data_len);
1831     silc_hmac_final(hmac, mac, &mac_len);
1832
1833     /* Compare the MAC's */
1834     if (silc_unlikely(memcmp(packet_mac, mac, mac_len))) {
1835       SILC_LOG_DEBUG(("MAC failed"));
1836       return FALSE;
1837     }
1838
1839     SILC_LOG_DEBUG(("MAC is Ok"));
1840   }
1841
1842   return TRUE;
1843 }
1844
1845 /* Increments/sets counter when decrypting in counter mode. */
1846
1847 static inline void silc_packet_receive_ctr_increment(SilcPacketStream stream,
1848                                                      unsigned char *iv,
1849                                                      unsigned char *packet_iv)
1850 {
1851   SilcUInt32 pc1, pc2;
1852
1853   /* If IV Included flag, set the IV from packet to block counter. */
1854   if (stream->iv_included) {
1855     memcpy(iv + 4, packet_iv, 8);
1856   } else {
1857     /* Increment 64-bit packet counter. */
1858     SILC_GET32_MSB(pc1, iv + 4);
1859     SILC_GET32_MSB(pc2, iv + 8);
1860     if (++pc2 == 0)
1861       ++pc1;
1862     SILC_PUT32_MSB(pc1, iv + 4);
1863     SILC_PUT32_MSB(pc2, iv + 8);
1864   }
1865
1866   /* Reset block counter */
1867   memset(iv + 12, 0, 4);
1868
1869   SILC_LOG_HEXDUMP(("Counter Block"), iv, 16);
1870 }
1871
1872 /* Decrypts SILC packet.  Handles both normal and special packet decryption.
1873    Return 0 when packet is normal and 1 when it it special, -1 on error. */
1874
1875 static inline int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
1876                                       SilcUInt32 sequence, SilcBuffer buffer,
1877                                       SilcBool normal)
1878 {
1879   if (normal == TRUE) {
1880     if (silc_likely(cipher)) {
1881       /* Decrypt rest of the packet */
1882       SILC_LOG_DEBUG(("Decrypting the packet"));
1883       if (silc_unlikely(!silc_cipher_decrypt(cipher, buffer->data,
1884                                              buffer->data,
1885                                              silc_buffer_len(buffer), NULL)))
1886         return -1;
1887     }
1888     return 0;
1889
1890   } else {
1891     /* Decrypt rest of the header plus padding */
1892     if (silc_likely(cipher)) {
1893       SilcUInt16 len;
1894       SilcUInt32 block_len = silc_cipher_get_block_len(cipher);
1895
1896       SILC_LOG_DEBUG(("Decrypting the header"));
1897
1898       /* Padding length + src id len + dst id len + header length - 16
1899          bytes already decrypted, gives the rest of the encrypted packet */
1900       silc_buffer_push(buffer, block_len);
1901       len = (((SilcUInt8)buffer->data[4] + (SilcUInt8)buffer->data[6] +
1902               (SilcUInt8)buffer->data[7] + SILC_PACKET_HEADER_LEN) -
1903              block_len);
1904       silc_buffer_pull(buffer, block_len);
1905
1906       if (silc_unlikely(len > silc_buffer_len(buffer))) {
1907         SILC_LOG_ERROR(("Garbage in header of packet, bad packet length, "
1908                         "packet dropped"));
1909         return -1;
1910       }
1911       if (silc_unlikely(!silc_cipher_decrypt(cipher, buffer->data,
1912                                              buffer->data, len, NULL)))
1913         return -1;
1914     }
1915
1916     return 1;
1917   }
1918 }
1919
1920 /* Parses the packet. This is called when a whole packet is ready to be
1921    parsed. The buffer sent must be already decrypted before calling this
1922    function. */
1923
1924 static inline SilcBool silc_packet_parse(SilcPacket packet)
1925 {
1926   SilcBuffer buffer = &packet->buffer;
1927   SilcUInt8 padlen = (SilcUInt8)buffer->data[4];
1928   SilcUInt8 src_id_len, dst_id_len, src_id_type, dst_id_type;
1929   int ret;
1930
1931   SILC_LOG_DEBUG(("Parsing incoming packet"));
1932
1933   /* Parse the buffer.  This parses the SILC header of the packet. */
1934   ret = silc_buffer_unformat(buffer,
1935                              SILC_STR_ADVANCE,
1936                              SILC_STR_OFFSET(6),
1937                              SILC_STR_UI_CHAR(&src_id_len),
1938                              SILC_STR_UI_CHAR(&dst_id_len),
1939                              SILC_STR_UI_CHAR(&src_id_type),
1940                              SILC_STR_END);
1941   if (silc_unlikely(ret == -1)) {
1942     if (!packet->stream->udp &&
1943         !silc_socket_stream_is_udp(packet->stream->stream, NULL))
1944       SILC_LOG_ERROR(("Malformed packet header, packet dropped"));
1945     return FALSE;
1946   }
1947
1948   if (silc_unlikely(src_id_len > SILC_PACKET_MAX_ID_LEN ||
1949                     dst_id_len > SILC_PACKET_MAX_ID_LEN)) {
1950     if (!packet->stream->udp &&
1951         !silc_socket_stream_is_udp(packet->stream->stream, NULL))
1952       SILC_LOG_ERROR(("Bad ID lengths in packet (%d and %d)",
1953                       packet->src_id_len, packet->dst_id_len));
1954     return FALSE;
1955   }
1956
1957   ret = silc_buffer_unformat(buffer,
1958                              SILC_STR_ADVANCE,
1959                              SILC_STR_DATA(&packet->src_id, src_id_len),
1960                              SILC_STR_UI_CHAR(&dst_id_type),
1961                              SILC_STR_DATA(&packet->dst_id, dst_id_len),
1962                              SILC_STR_OFFSET(padlen),
1963                              SILC_STR_END);
1964   if (silc_unlikely(ret == -1)) {
1965     if (!packet->stream->udp &&
1966         !silc_socket_stream_is_udp(packet->stream->stream, NULL))
1967       SILC_LOG_ERROR(("Malformed packet header, packet dropped"));
1968     return FALSE;
1969   }
1970
1971   if (silc_unlikely(src_id_type > SILC_ID_CHANNEL ||
1972                     dst_id_type > SILC_ID_CHANNEL)) {
1973     if (!packet->stream->udp &&
1974         !silc_socket_stream_is_udp(packet->stream->stream, NULL))
1975       SILC_LOG_ERROR(("Bad ID types in packet (%d and %d)",
1976                       src_id_type, dst_id_type));
1977     return FALSE;
1978   }
1979
1980   packet->src_id_len = src_id_len;
1981   packet->dst_id_len = dst_id_len;
1982   packet->src_id_type = src_id_type;
1983   packet->dst_id_type = dst_id_type;
1984
1985   SILC_LOG_HEXDUMP(("Parsed packet, len %d", silc_buffer_headlen(buffer) +
1986                    silc_buffer_len(buffer)), buffer->head,
1987                    silc_buffer_headlen(buffer) + silc_buffer_len(buffer));
1988
1989   SILC_LOG_DEBUG(("Incoming packet type: %d (%s), flags %d", packet->type,
1990                   silc_get_packet_name(packet->type), packet->flags));
1991
1992   return TRUE;
1993 }
1994
1995 /* Dispatch packet to application.  Called with stream->lock locked.
1996    Returns FALSE if the stream was destroyed while dispatching a packet. */
1997
1998 static SilcBool silc_packet_dispatch(SilcPacket packet)
1999 {
2000   SilcPacketStream stream = packet->stream;
2001   SilcPacketProcess p;
2002   SilcBool default_sent = FALSE;
2003   SilcPacketType *pt;
2004
2005   /* Dispatch packet to all packet processors that want it */
2006
2007   if (silc_likely(!stream->process)) {
2008     /* Send to default processor as no others exist */
2009     SILC_LOG_DEBUG(("Dispatching packet to default callbacks"));
2010     silc_mutex_unlock(stream->lock);
2011     if (silc_unlikely(!stream->sc->engine->callbacks->
2012                       packet_receive(stream->sc->engine, stream, packet,
2013                                      stream->sc->engine->callback_context,
2014                                      stream->stream_context)))
2015       silc_packet_free(packet);
2016     silc_mutex_lock(stream->lock);
2017     return stream->destroyed == FALSE;
2018   }
2019
2020   silc_dlist_start(stream->process);
2021   while ((p = silc_dlist_get(stream->process)) != SILC_LIST_END) {
2022
2023     /* If priority is 0 or less, we send to default processor first
2024        because default processor has 0 priority */
2025     if (!default_sent && p->priority <= 0) {
2026       SILC_LOG_DEBUG(("Dispatching packet to default callbacks"));
2027       default_sent = TRUE;
2028       silc_mutex_unlock(stream->lock);
2029       if (stream->sc->engine->callbacks->
2030           packet_receive(stream->sc->engine, stream, packet,
2031                          stream->sc->engine->callback_context,
2032                          stream->stream_context)) {
2033         silc_mutex_lock(stream->lock);
2034         return stream->destroyed == FALSE;
2035       }
2036       silc_mutex_lock(stream->lock);
2037     }
2038
2039     /* Send to processor */
2040     if (!p->types) {
2041       /* Send all packet types */
2042       SILC_LOG_DEBUG(("Dispatching packet to %p callbacks", p->callbacks));
2043       silc_mutex_unlock(stream->lock);
2044       if (p->callbacks->packet_receive(stream->sc->engine, stream, packet,
2045                                        p->callback_context,
2046                                        stream->stream_context)) {
2047         silc_mutex_lock(stream->lock);
2048         return stream->destroyed == FALSE;
2049       }
2050       silc_mutex_lock(stream->lock);
2051     } else {
2052       /* Send specific types */
2053       for (pt = p->types; *pt; pt++) {
2054         if (*pt != packet->type)
2055           continue;
2056         SILC_LOG_DEBUG(("Dispatching packet to %p callbacks", p->callbacks));
2057         silc_mutex_unlock(stream->lock);
2058         if (p->callbacks->packet_receive(stream->sc->engine, stream, packet,
2059                                          p->callback_context,
2060                                          stream->stream_context)) {
2061           silc_mutex_lock(stream->lock);
2062           return stream->destroyed == FALSE;
2063         }
2064         silc_mutex_lock(stream->lock);
2065         break;
2066       }
2067     }
2068   }
2069
2070   if (!default_sent) {
2071     /* Send to default processor as it has not been sent yet */
2072     SILC_LOG_DEBUG(("Dispatching packet to default callbacks"));
2073     silc_mutex_unlock(stream->lock);
2074     if (stream->sc->engine->callbacks->
2075         packet_receive(stream->sc->engine, stream, packet,
2076                        stream->sc->engine->callback_context,
2077                        stream->stream_context)) {
2078       silc_mutex_lock(stream->lock);
2079       return stream->destroyed == FALSE;
2080     }
2081     silc_mutex_lock(stream->lock);
2082   }
2083
2084   /* If we got here, no one wanted the packet, so drop it */
2085   silc_packet_free(packet);
2086   return stream->destroyed == FALSE;
2087 }
2088
2089 /* Process incoming data and parse packets.  Called with stream->lock
2090    locked. */
2091
2092 static void silc_packet_read_process(SilcPacketStream stream)
2093 {
2094   SilcBuffer inbuf;
2095   SilcCipher cipher;
2096   SilcHmac hmac;
2097   SilcPacket packet;
2098   SilcUInt8 sid;
2099   SilcUInt16 packetlen;
2100   SilcUInt32 paddedlen, mac_len, block_len, ivlen, psnlen;
2101   unsigned char tmp[SILC_PACKET_MIN_HEADER_LEN], *header;
2102   unsigned char iv[SILC_CIPHER_MAX_IV_SIZE], *packet_seq = NULL;
2103   SilcBool normal;
2104   int ret;
2105
2106   /* Get inbuf.  If there is already some data for this stream in the buffer
2107      we already have it.  Otherwise get the current one from list, it will
2108      include the data. */
2109   inbuf = stream->inbuf;
2110   if (!inbuf) {
2111     silc_dlist_start(stream->sc->inbufs);
2112     inbuf = silc_dlist_get(stream->sc->inbufs);
2113   }
2114
2115   /* Parse the packets from the data */
2116   while (silc_buffer_len(inbuf) > 0) {
2117     ivlen = psnlen = 0;
2118     cipher = stream->receive_key[0];
2119     hmac = stream->receive_hmac[0];
2120     normal = FALSE;
2121
2122     if (silc_unlikely(silc_buffer_len(inbuf) <
2123                       (stream->iv_included ? SILC_PACKET_MIN_HEADER_LEN_IV :
2124                        SILC_PACKET_MIN_HEADER_LEN))) {
2125       SILC_LOG_DEBUG(("Partial packet in queue, waiting for the rest"));
2126       silc_dlist_del(stream->sc->inbufs, inbuf);
2127       stream->inbuf = inbuf;
2128       return;
2129     }
2130
2131     if (silc_likely(hmac))
2132       mac_len = silc_hmac_len(hmac);
2133     else
2134       mac_len = 0;
2135
2136     /* Decrypt first block of the packet to get the length field out */
2137     if (silc_likely(cipher)) {
2138       block_len = silc_cipher_get_block_len(cipher);
2139
2140       if (stream->iv_included) {
2141         /* SID, IV and sequence number is included in the ciphertext */
2142         sid = (SilcUInt8)inbuf->data[0];
2143
2144         if (silc_cipher_get_mode(cipher) == SILC_CIPHER_MODE_CTR) {
2145           /* Set the CTR mode IV from packet to counter block */
2146           memcpy(iv, silc_cipher_get_iv(cipher), block_len);
2147           silc_packet_receive_ctr_increment(stream, iv, inbuf->data + 1);
2148           ivlen = 8 + 1;
2149         } else {
2150           /* Get IV from packet */
2151           memcpy(iv, inbuf->data + 1, block_len);
2152           ivlen = block_len + 1;
2153         }
2154         psnlen = 4;
2155
2156         /* Check SID, and get correct decryption key */
2157         if (sid != stream->sid) {
2158           /* If SID is recent get the previous key and use it */
2159           if (sid > 0 && stream->sid > 0 && stream->sid - 1 == sid &&
2160               stream->receive_key[1] && !stream->receive_hmac[1]) {
2161             cipher = stream->receive_key[1];
2162             hmac = stream->receive_hmac[1];
2163           } else {
2164             /* The SID is unknown, drop rest of the data in buffer */
2165             SILC_LOG_DEBUG(("Unknown Security ID %d in packet, expected %d",
2166                             sid, stream->sid));
2167             silc_mutex_unlock(stream->lock);
2168             SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_UNKNOWN_SID);
2169             silc_mutex_lock(stream->lock);
2170             goto out;
2171           }
2172         }
2173       } else {
2174         memcpy(iv, silc_cipher_get_iv(cipher), block_len);
2175
2176         /* If using CTR mode, increment the counter */
2177         if (silc_cipher_get_mode(cipher) == SILC_CIPHER_MODE_CTR)
2178           silc_packet_receive_ctr_increment(stream, iv, NULL);
2179       }
2180
2181       if (silc_cipher_get_mode(cipher) == SILC_CIPHER_MODE_CTR)
2182         silc_cipher_set_iv(cipher, NULL);
2183       silc_cipher_decrypt(cipher, inbuf->data + ivlen, tmp, block_len, iv);
2184
2185       header = tmp;
2186       if (stream->iv_included) {
2187         /* Take sequence number from packet */
2188         packet_seq = header;
2189         header += 4;
2190       }
2191     } else {
2192       /* Unencrypted packet */
2193       block_len = SILC_PACKET_MIN_HEADER_LEN;
2194       header = inbuf->data;
2195     }
2196
2197     /* Get packet length and full packet length with padding */
2198     SILC_PACKET_LENGTH(header, packetlen, paddedlen);
2199
2200     /* Padding sanity checks */
2201     if (cipher && (paddedlen % block_len) != 0) {
2202       SILC_LOG_DEBUG(("Packet length %d not multiple by cipher block length",
2203                       paddedlen));
2204       silc_mutex_unlock(stream->lock);
2205       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MALFORMED);
2206       silc_mutex_lock(stream->lock);
2207       memset(tmp, 0, sizeof(tmp));
2208       goto out;
2209     }
2210
2211     if (silc_buffer_len(inbuf) < paddedlen + ivlen + mac_len) {
2212       SILC_LOG_DEBUG(("Received partial packet, waiting for the rest "
2213                       "(%d bytes)",
2214                       paddedlen + mac_len - silc_buffer_len(inbuf)));
2215       memset(tmp, 0, sizeof(tmp));
2216       silc_dlist_del(stream->sc->inbufs, inbuf);
2217       stream->inbuf = inbuf;
2218       return;
2219     }
2220
2221     /* Check MAC of the packet */
2222     if (silc_unlikely(!silc_packet_check_mac(hmac, inbuf->data,
2223                                              paddedlen + ivlen,
2224                                              inbuf->data + ivlen +
2225                                              paddedlen, packet_seq,
2226                                              stream->receive_psn))) {
2227       silc_mutex_unlock(stream->lock);
2228       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MAC_FAILED);
2229       silc_mutex_lock(stream->lock);
2230       memset(tmp, 0, sizeof(tmp));
2231       goto out;
2232     }
2233
2234     /* Sanity checks */
2235     if (silc_unlikely(packetlen < SILC_PACKET_MIN_LEN)) {
2236       if (!stream->udp && !silc_socket_stream_is_udp(stream->stream, NULL))
2237         SILC_LOG_ERROR(("Received too short packet"));
2238       silc_mutex_unlock(stream->lock);
2239       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MALFORMED);
2240       silc_mutex_lock(stream->lock);
2241       memset(tmp, 0, sizeof(tmp));
2242       goto out;
2243     }
2244
2245     /* Get packet */
2246     packet = silc_packet_alloc(stream->sc->engine);
2247     if (silc_unlikely(!packet)) {
2248       silc_mutex_unlock(stream->lock);
2249       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_NO_MEMORY);
2250       silc_mutex_lock(stream->lock);
2251       memset(tmp, 0, sizeof(tmp));
2252       goto out;
2253     }
2254     packet->stream = stream;
2255
2256     /* Allocate more space to packet buffer, if needed */
2257     if (silc_unlikely(silc_buffer_truelen(&packet->buffer) < paddedlen)) {
2258       if (!silc_buffer_realloc(&packet->buffer,
2259                                silc_buffer_truelen(&packet->buffer) +
2260                                (paddedlen -
2261                                 silc_buffer_truelen(&packet->buffer)))) {
2262         silc_mutex_unlock(stream->lock);
2263         SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_NO_MEMORY);
2264         silc_mutex_lock(stream->lock);
2265         silc_packet_free(packet);
2266         memset(tmp, 0, sizeof(tmp));
2267         goto out;
2268       }
2269     }
2270
2271     /* Parse packet header */
2272     packet->flags = (SilcPacketFlags)header[2];
2273     packet->type = (SilcPacketType)header[3];
2274
2275     if (stream->sc->engine->local_is_router) {
2276       if (packet->type == SILC_PACKET_PRIVATE_MESSAGE &&
2277           (packet->flags & SILC_PACKET_FLAG_PRIVMSG_KEY))
2278         normal = FALSE;
2279       else if (packet->type != SILC_PACKET_CHANNEL_MESSAGE ||
2280                (packet->type == SILC_PACKET_CHANNEL_MESSAGE &&
2281                 stream->is_router == TRUE))
2282         normal = TRUE;
2283     } else {
2284       if (packet->type == SILC_PACKET_PRIVATE_MESSAGE &&
2285           (packet->flags & SILC_PACKET_FLAG_PRIVMSG_KEY))
2286         normal = FALSE;
2287       else if (packet->type != SILC_PACKET_CHANNEL_MESSAGE)
2288         normal = TRUE;
2289     }
2290
2291     SILC_LOG_HEXDUMP(("Incoming packet (%d) len %d",
2292                       stream->receive_psn, paddedlen + ivlen + mac_len),
2293                      inbuf->data, paddedlen + ivlen + mac_len);
2294
2295     /* Put the decrypted part, and rest of the encrypted data, and decrypt */
2296     silc_buffer_pull_tail(&packet->buffer, paddedlen);
2297     silc_buffer_put(&packet->buffer, header, block_len - psnlen);
2298     silc_buffer_pull(&packet->buffer, block_len - psnlen);
2299     silc_buffer_put(&packet->buffer, (inbuf->data + ivlen +
2300                                       psnlen + (block_len - psnlen)),
2301                     paddedlen - ivlen - psnlen - (block_len - psnlen));
2302     if (silc_likely(cipher)) {
2303       silc_cipher_set_iv(cipher, iv);
2304       ret = silc_packet_decrypt(cipher, hmac, stream->receive_psn,
2305                                 &packet->buffer, normal);
2306       if (silc_unlikely(ret < 0)) {
2307         silc_mutex_unlock(stream->lock);
2308         SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_DECRYPTION_FAILED);
2309         silc_mutex_lock(stream->lock);
2310         silc_packet_free(packet);
2311         memset(tmp, 0, sizeof(tmp));
2312         goto out;
2313       }
2314
2315       stream->receive_psn++;
2316     }
2317     silc_buffer_push(&packet->buffer, block_len);
2318
2319     /* Pull the packet from inbuf thus we'll get the next one in the inbuf. */
2320     silc_buffer_pull(inbuf, paddedlen + mac_len);
2321
2322     /* Parse the packet */
2323     if (silc_unlikely(!silc_packet_parse(packet))) {
2324       silc_mutex_unlock(stream->lock);
2325       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MALFORMED);
2326       silc_mutex_lock(stream->lock);
2327       silc_packet_free(packet);
2328       memset(tmp, 0, sizeof(tmp));
2329       goto out;
2330     }
2331
2332     /* Dispatch the packet to application */
2333     if (!silc_packet_dispatch(packet))
2334       break;
2335   }
2336
2337  out:
2338   /* Add inbuf back to free list, if we owned it. */
2339   if (stream->inbuf) {
2340     silc_dlist_add(stream->sc->inbufs, inbuf);
2341     stream->inbuf = NULL;
2342   }
2343
2344   silc_buffer_reset(inbuf);
2345 }
2346
2347 /****************************** Packet Waiting ******************************/
2348
2349 /* Packet wait receive callback */
2350 static SilcBool
2351 silc_packet_wait_packet_receive(SilcPacketEngine engine,
2352                                 SilcPacketStream stream,
2353                                 SilcPacket packet,
2354                                 void *callback_context,
2355                                 void *stream_context);
2356
2357 /* Packet waiting callbacks */
2358 static const SilcPacketCallbacks silc_packet_wait_cbs =
2359 {
2360   silc_packet_wait_packet_receive, NULL, NULL
2361 };
2362
2363 /* Packet waiting context */
2364 typedef struct {
2365   SilcMutex wait_lock;
2366   SilcCond wait_cond;
2367   SilcList packet_queue;
2368   unsigned char id[28];
2369   unsigned int id_type     : 2;
2370   unsigned int id_len      : 5;
2371   unsigned int stopped     : 1;
2372 } *SilcPacketWait;
2373
2374 /* Packet wait receive callback */
2375
2376 static SilcBool
2377 silc_packet_wait_packet_receive(SilcPacketEngine engine,
2378                                 SilcPacketStream stream,
2379                                 SilcPacket packet,
2380                                 void *callback_context,
2381                                 void *stream_context)
2382 {
2383   SilcPacketWait pw = callback_context;
2384
2385   /* If source ID is specified check for it */
2386   if (pw->id_len) {
2387     if (pw->id_type != packet->src_id_type ||
2388         memcmp(pw->id, packet->src_id, pw->id_len))
2389       return FALSE;
2390   }
2391
2392   /* Signal the waiting thread for a new packet */
2393   silc_mutex_lock(pw->wait_lock);
2394
2395   if (silc_unlikely(pw->stopped)) {
2396     silc_mutex_unlock(pw->wait_lock);
2397     return FALSE;
2398   }
2399
2400   silc_list_add(pw->packet_queue, packet);
2401   silc_cond_broadcast(pw->wait_cond);
2402
2403   silc_mutex_unlock(pw->wait_lock);
2404
2405   return TRUE;
2406 }
2407
2408 /* Initialize packet waiting */
2409
2410 void *silc_packet_wait_init(SilcPacketStream stream,
2411                             const SilcID *source_id, ...)
2412 {
2413   SilcPacketWait pw;
2414   SilcBool ret;
2415   va_list ap;
2416
2417   pw = silc_calloc(1, sizeof(*pw));
2418   if (!pw)
2419     return NULL;
2420
2421   /* Allocate mutex and conditional variable */
2422   if (!silc_mutex_alloc(&pw->wait_lock)) {
2423     silc_free(pw);
2424     return NULL;
2425   }
2426   if (!silc_cond_alloc(&pw->wait_cond)) {
2427     silc_mutex_free(pw->wait_lock);
2428     silc_free(pw);
2429     return NULL;
2430   }
2431
2432   /* Link to the packet stream for the requested packet types */
2433   va_start(ap, source_id);
2434   ret = silc_packet_stream_link_va(stream, &silc_packet_wait_cbs, pw,
2435                                    10000000, ap);
2436   va_end(ap);
2437   if (!ret) {
2438     silc_cond_free(pw->wait_cond);
2439     silc_mutex_free(pw->wait_lock);
2440     silc_free(pw);
2441     return NULL;
2442   }
2443
2444   /* Initialize packet queue */
2445   silc_list_init(pw->packet_queue, struct SilcPacketStruct, next);
2446
2447   if (source_id) {
2448     SilcUInt32 id_len;
2449     silc_id_id2str(SILC_ID_GET_ID(*source_id), source_id->type, pw->id,
2450                    sizeof(pw->id), &id_len);
2451     pw->id_type = source_id->type;
2452     pw->id_len = id_len;
2453   }
2454
2455   return (void *)pw;
2456 }
2457
2458 /* Uninitialize packet waiting */
2459
2460 void silc_packet_wait_uninit(void *waiter, SilcPacketStream stream)
2461 {
2462   SilcPacketWait pw = waiter;
2463   SilcPacket packet;
2464
2465   /* Signal any threads to stop waiting */
2466   silc_mutex_lock(pw->wait_lock);
2467   pw->stopped = TRUE;
2468   silc_cond_broadcast(pw->wait_cond);
2469   silc_mutex_unlock(pw->wait_lock);
2470   silc_thread_yield();
2471
2472   /* Re-acquire lock and free resources */
2473   silc_mutex_lock(pw->wait_lock);
2474   silc_packet_stream_unlink(stream, &silc_packet_wait_cbs, pw);
2475
2476   /* Free any remaining packets */
2477   silc_list_start(pw->packet_queue);
2478   while ((packet = silc_list_get(pw->packet_queue)) != SILC_LIST_END)
2479     silc_packet_free(packet);
2480
2481   silc_mutex_unlock(pw->wait_lock);
2482   silc_cond_free(pw->wait_cond);
2483   silc_mutex_free(pw->wait_lock);
2484   silc_free(pw);
2485 }
2486
2487 /* Blocks thread until a packet has been received. */
2488
2489 int silc_packet_wait(void *waiter, int timeout, SilcPacket *return_packet)
2490 {
2491   SilcPacketWait pw = waiter;
2492   SilcBool ret = FALSE;
2493
2494   silc_mutex_lock(pw->wait_lock);
2495
2496   /* Wait here until packet has arrived */
2497   while (silc_list_count(pw->packet_queue) == 0) {
2498     if (silc_unlikely(pw->stopped)) {
2499       silc_mutex_unlock(pw->wait_lock);
2500       return -1;
2501     }
2502     ret = silc_cond_timedwait(pw->wait_cond, pw->wait_lock, timeout);
2503   }
2504
2505   /* Return packet */
2506   silc_list_start(pw->packet_queue);
2507   *return_packet = silc_list_get(pw->packet_queue);
2508   silc_list_del(pw->packet_queue, *return_packet);
2509
2510   silc_mutex_unlock(pw->wait_lock);
2511
2512   return ret == TRUE ? 1 : 0;
2513 }
2514
2515 /************************** Packet Stream Wrapper ***************************/
2516
2517 /* Packet stream wrapper receive callback */
2518 static SilcBool
2519 silc_packet_wrap_packet_receive(SilcPacketEngine engine,
2520                                 SilcPacketStream stream,
2521                                 SilcPacket packet,
2522                                 void *callback_context,
2523                                 void *stream_context);
2524
2525 const SilcStreamOps silc_packet_stream_ops;
2526
2527 /* Packet stream wrapper context */
2528 typedef struct {
2529   const SilcStreamOps *ops;
2530   SilcPacketStream stream;
2531   SilcMutex lock;
2532   void *waiter;                   /* Waiter context in blocking mode */
2533   SilcPacketWrapCoder coder;
2534   void *coder_context;
2535   SilcBuffer encbuf;
2536   SilcStreamNotifier callback;
2537   void *context;
2538   SilcList in_queue;
2539   SilcPacketType type;
2540   SilcPacketFlags flags;
2541   unsigned int closed        : 1;
2542   unsigned int blocking      : 1;
2543   unsigned int read_more     : 1;
2544 } *SilcPacketWrapperStream;
2545
2546 /* Packet wrapper callbacks */
2547 static const SilcPacketCallbacks silc_packet_wrap_cbs =
2548 {
2549   silc_packet_wrap_packet_receive, NULL, NULL
2550 };
2551
2552 /* Packet stream wrapper receive callback, non-blocking mode */
2553
2554 static SilcBool
2555 silc_packet_wrap_packet_receive(SilcPacketEngine engine,
2556                                 SilcPacketStream stream,
2557                                 SilcPacket packet,
2558                                 void *callback_context,
2559                                 void *stream_context)
2560 {
2561   SilcPacketWrapperStream pws = callback_context;
2562
2563   if (pws->closed || !pws->callback)
2564     return FALSE;
2565
2566   silc_mutex_lock(pws->lock);
2567   silc_list_add(pws->in_queue, packet);
2568   silc_mutex_unlock(pws->lock);
2569
2570   /* Call notifier callback */
2571   pws->callback((SilcStream)pws, SILC_STREAM_CAN_READ, pws->context);
2572
2573   return TRUE;
2574 }
2575
2576 /* Task callback to notify more data is available for reading */
2577
2578 SILC_TASK_CALLBACK(silc_packet_wrap_read_more)
2579 {
2580   SilcPacketWrapperStream pws = context;
2581
2582   if (pws->closed || !pws->callback)
2583     return;
2584
2585   /* Call notifier callback */
2586   pws->callback((SilcStream)pws, SILC_STREAM_CAN_READ, pws->context);
2587 }
2588
2589 /* Read SILC packet */
2590
2591 int silc_packet_wrap_read(SilcStream stream, unsigned char *buf,
2592                           SilcUInt32 buf_len)
2593 {
2594   SilcPacketWrapperStream pws = stream;
2595   SilcPacket packet;
2596   SilcBool read_more = FALSE;
2597   int len;
2598
2599   if (pws->closed)
2600     return -2;
2601
2602   if (pws->blocking) {
2603     /* Block until packet is received */
2604     if ((silc_packet_wait(pws->waiter, 0, &packet)) < 0)
2605       return -2;
2606     if (pws->closed)
2607       return -2;
2608   } else {
2609     /* Non-blocking mode */
2610     silc_mutex_lock(pws->lock);
2611     if (!silc_list_count(pws->in_queue)) {
2612       silc_mutex_unlock(pws->lock);
2613       return -1;
2614     }
2615
2616     silc_list_start(pws->in_queue);
2617     packet = silc_list_get(pws->in_queue);
2618     silc_list_del(pws->in_queue, packet);
2619     silc_mutex_unlock(pws->lock);
2620   }
2621
2622   /* Call decoder if set */
2623   if (pws->coder && !pws->read_more)
2624     pws->coder(stream, SILC_STREAM_CAN_READ, &packet->buffer,
2625                pws->coder_context);
2626
2627   len = silc_buffer_len(&packet->buffer);
2628   if (len > buf_len) {
2629     len = buf_len;
2630     read_more = TRUE;
2631   }
2632
2633   /* Read data */
2634   memcpy(buf, packet->buffer.data, len);
2635
2636   if (read_more && !pws->blocking) {
2637     /* More data will be available (in blocking mode not supported). */
2638     silc_buffer_pull(&packet->buffer, len);
2639     silc_list_insert(pws->in_queue, NULL, packet);
2640     silc_schedule_task_add_timeout(pws->stream->sc->schedule,
2641                                    silc_packet_wrap_read_more, pws, 0, 0);
2642     pws->read_more = TRUE;
2643     return len;
2644   }
2645
2646   pws->read_more = FALSE;
2647   silc_packet_free(packet);
2648   return len;
2649 }
2650
2651 /* Write SILC packet */
2652
2653 int silc_packet_wrap_write(SilcStream stream, const unsigned char *data,
2654                            SilcUInt32 data_len)
2655 {
2656   SilcPacketWrapperStream pws = stream;
2657   SilcBool ret = FALSE;
2658
2659   /* Call encoder if set */
2660   if (pws->coder) {
2661     silc_buffer_reset(pws->encbuf);
2662     ret = pws->coder(stream, SILC_STREAM_CAN_WRITE, pws->encbuf,
2663                      pws->coder_context);
2664   }
2665
2666   /* Send the SILC packet */
2667   if (ret) {
2668     if (!silc_packet_send_va(pws->stream, pws->type, pws->flags,
2669                              SILC_STR_DATA(silc_buffer_data(pws->encbuf),
2670                                            silc_buffer_len(pws->encbuf)),
2671                              SILC_STR_DATA(data, data_len),
2672                              SILC_STR_END))
2673       return -2;
2674   } else {
2675     if (!silc_packet_send(pws->stream, pws->type, pws->flags, data, data_len))
2676       return -2;
2677   }
2678
2679   return data_len;
2680 }
2681
2682 /* Close stream */
2683
2684 SilcBool silc_packet_wrap_close(SilcStream stream)
2685 {
2686   SilcPacketWrapperStream pws = stream;
2687
2688   if (pws->closed)
2689     return TRUE;
2690
2691   if (pws->blocking) {
2692     /* Close packet waiter */
2693     silc_packet_wait_uninit(pws->waiter, pws->stream);
2694   } else {
2695     /* Unlink */
2696     if (pws->callback)
2697       silc_packet_stream_unlink(pws->stream, &silc_packet_wrap_cbs, pws);
2698   }
2699   pws->closed = TRUE;
2700
2701   return TRUE;
2702 }
2703
2704 /* Destroy wrapper stream */
2705
2706 void silc_packet_wrap_destroy(SilcStream stream)
2707
2708 {
2709   SilcPacketWrapperStream pws = stream;
2710   SilcPacket packet;
2711
2712   SILC_LOG_DEBUG(("Destroying wrapped packet stream %p", pws));
2713
2714   silc_stream_close(stream);
2715   silc_list_start(pws->in_queue);
2716   while ((packet = silc_list_get(pws->in_queue)))
2717     silc_packet_free(packet);
2718   if (pws->lock)
2719     silc_mutex_free(pws->lock);
2720   if (pws->encbuf)
2721     silc_buffer_free(pws->encbuf);
2722   silc_packet_stream_unref(pws->stream);
2723
2724   silc_free(pws);
2725 }
2726
2727 /* Link stream to receive packets */
2728
2729 SilcBool silc_packet_wrap_notifier(SilcStream stream,
2730                                    SilcSchedule schedule,
2731                                    SilcStreamNotifier callback,
2732                                    void *context)
2733 {
2734   SilcPacketWrapperStream pws = stream;
2735
2736   if (pws->closed || pws->blocking)
2737     return FALSE;
2738
2739   /* Link to receive packets */
2740   if (callback)
2741     silc_packet_stream_link(pws->stream, &silc_packet_wrap_cbs, pws,
2742                             100000, pws->type, -1);
2743   else
2744     silc_packet_stream_unlink(pws->stream, &silc_packet_wrap_cbs, pws);
2745
2746   pws->callback = callback;
2747   pws->context = context;
2748
2749   return TRUE;
2750 }
2751
2752 /* Return schedule */
2753
2754 SilcSchedule silc_packet_wrap_get_schedule(SilcStream stream)
2755 {
2756   return NULL;
2757 }
2758
2759 /* Wraps packet stream into SilcStream. */
2760
2761 SilcStream silc_packet_stream_wrap(SilcPacketStream stream,
2762                                    SilcPacketType type,
2763                                    SilcPacketFlags flags,
2764                                    SilcBool blocking_mode,
2765                                    SilcPacketWrapCoder coder,
2766                                    void *context)
2767 {
2768   SilcPacketWrapperStream pws;
2769
2770   pws = silc_calloc(1, sizeof(*pws));
2771   if (!pws)
2772     return NULL;
2773
2774   SILC_LOG_DEBUG(("Wrapping packet stream %p to stream %p", stream, pws));
2775
2776   pws->ops = &silc_packet_stream_ops;
2777   pws->stream = stream;
2778   pws->type = type;
2779   pws->flags = flags;
2780   pws->blocking = blocking_mode;
2781   pws->coder = coder;
2782   pws->coder_context = context;
2783
2784   /* Allocate small amount for encoder buffer. */
2785   if (pws->coder)
2786     pws->encbuf = silc_buffer_alloc(8);
2787
2788   if (pws->blocking) {
2789     /* Blocking mode.  Use packet waiter to do the thing. */
2790     pws->waiter = silc_packet_wait_init(pws->stream, NULL, pws->type, -1);
2791     if (!pws->waiter) {
2792       silc_free(pws);
2793       return NULL;
2794     }
2795   } else {
2796     /* Non-blocking mode */
2797     silc_mutex_alloc(&pws->lock);
2798     silc_list_init(pws->in_queue, struct SilcPacketStruct, next);
2799   }
2800
2801   silc_packet_stream_ref(stream);
2802
2803   return (SilcStream)pws;
2804 }
2805
2806 const SilcStreamOps silc_packet_stream_ops =
2807 {
2808   silc_packet_wrap_read,
2809   silc_packet_wrap_write,
2810   silc_packet_wrap_close,
2811   silc_packet_wrap_destroy,
2812   silc_packet_wrap_notifier,
2813   silc_packet_wrap_get_schedule,
2814 };