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   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   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   SilcAtomic8 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                          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_init8(&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_init8(&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_int8(&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_uninit8(&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                                            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                                  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                                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_int8(&stream->refcnt, 1);
1158   SILC_LOG_DEBUG(("Stream %p, refcnt %d->%d", stream,
1159                   silc_atomic_get_int8(&stream->refcnt) - 1,
1160                   silc_atomic_get_int8(&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_int8(&stream->refcnt),
1169                   silc_atomic_get_int8(&stream->refcnt) - 1));
1170   if (silc_atomic_sub_int8(&stream->refcnt, 1) > 0)
1171     return;
1172   silc_atomic_add_int8(&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
1328   if (!src_id && !dst_id)
1329     return FALSE;
1330
1331   silc_mutex_lock(stream->lock);
1332
1333   if (src_id) {
1334     SILC_LOG_DEBUG(("Setting source ID to packet stream %p", stream));
1335
1336     silc_free(stream->src_id);
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     stream->src_id = silc_memdup(tmp, len);
1342     if (!stream->src_id) {
1343       silc_mutex_unlock(stream->lock);
1344       return FALSE;
1345     }
1346     stream->src_id_type = src_id_type;
1347     stream->src_id_len = len;
1348   }
1349
1350   if (dst_id) {
1351     SILC_LOG_DEBUG(("Setting destination ID to packet stream %p", stream));
1352
1353     silc_free(stream->dst_id);
1354     if (!silc_id_id2str(dst_id, dst_id_type, tmp, sizeof(tmp), &len)) {
1355       silc_mutex_unlock(stream->lock);
1356       return FALSE;
1357     }
1358     stream->dst_id = silc_memdup(tmp, len);
1359     if (!stream->dst_id) {
1360       silc_mutex_unlock(stream->lock);
1361       return FALSE;
1362     }
1363     stream->dst_id_type = dst_id_type;
1364     stream->dst_id_len = len;
1365   }
1366
1367   silc_mutex_unlock(stream->lock);
1368
1369   return TRUE;
1370 }
1371
1372 /* Return IDs from the packet stream */
1373
1374 SilcBool silc_packet_get_ids(SilcPacketStream stream,
1375                              SilcBool *src_id_set, SilcID *src_id,
1376                              SilcBool *dst_id_set, SilcID *dst_id)
1377 {
1378   if (src_id && stream->src_id)
1379     if (!silc_id_str2id2(stream->src_id, stream->src_id_len,
1380                          stream->src_id_type, src_id))
1381       return FALSE;
1382
1383   if (stream->src_id && src_id_set)
1384     *src_id_set = TRUE;
1385
1386   if (dst_id && stream->dst_id)
1387     if (!silc_id_str2id2(stream->dst_id, stream->dst_id_len,
1388                          stream->dst_id_type, dst_id))
1389       return FALSE;
1390
1391   if (stream->dst_id && dst_id_set)
1392     *dst_id_set = TRUE;
1393
1394   return TRUE;
1395 }
1396
1397 /* Adds Security ID (SID) */
1398
1399 SilcBool silc_packet_set_sid(SilcPacketStream stream, SilcUInt8 sid)
1400 {
1401   if (!stream->iv_included)
1402     return FALSE;
1403
1404   SILC_LOG_DEBUG(("Set packet stream %p SID to %d", stream, sid));
1405
1406   stream->sid = sid;
1407   return TRUE;
1408 }
1409
1410 /* Free packet */
1411
1412 void silc_packet_free(SilcPacket packet)
1413 {
1414   SilcPacketStream stream = packet->stream;
1415
1416   SILC_LOG_DEBUG(("Freeing packet %p", packet));
1417
1418   /* Check for double free */
1419   SILC_ASSERT(packet->stream != NULL);
1420
1421   packet->stream = NULL;
1422   packet->src_id = packet->dst_id = NULL;
1423   silc_buffer_reset(&packet->buffer);
1424
1425   silc_mutex_lock(stream->sc->engine->lock);
1426
1427   /* Put the packet back to freelist */
1428   silc_list_add(stream->sc->engine->packet_pool, packet);
1429   if (silc_list_count(stream->sc->engine->packet_pool) == 1)
1430     silc_list_start(stream->sc->engine->packet_pool);
1431
1432   silc_mutex_unlock(stream->sc->engine->lock);
1433 }
1434
1435 /****************************** Packet Sending ******************************/
1436
1437 /* Prepare outgoing data buffer for packet sending.  Returns the
1438    pointer to that buffer into the `packet'. */
1439
1440 static inline SilcBool silc_packet_send_prepare(SilcPacketStream stream,
1441                                                 SilcUInt32 totlen,
1442                                                 SilcHmac hmac,
1443                                                 SilcBuffer packet)
1444 {
1445   unsigned char *oldptr;
1446   unsigned int mac_len = hmac ? silc_hmac_len(hmac) : 0;
1447
1448   totlen += mac_len;
1449
1450   /* Allocate more space if needed */
1451   if (silc_unlikely(silc_buffer_taillen(&stream->outbuf) < totlen)) {
1452     if (!silc_buffer_realloc(&stream->outbuf,
1453                              silc_buffer_truelen(&stream->outbuf) + totlen))
1454       return FALSE;
1455   }
1456
1457   /* Pull data area for the new packet, and return pointer to the start of
1458      the data area and save the pointer in to the `packet'.  MAC is pulled
1459      later after it's computed. */
1460   oldptr = silc_buffer_pull_tail(&stream->outbuf, totlen);
1461   silc_buffer_set(packet, oldptr, totlen);
1462   silc_buffer_push_tail(packet, mac_len);
1463
1464   return TRUE;
1465 }
1466
1467 /* Increments counter when encrypting in counter mode. */
1468
1469 static inline void silc_packet_send_ctr_increment(SilcPacketStream stream,
1470                                                   SilcCipher cipher,
1471                                                   unsigned char *ret_iv)
1472 {
1473   unsigned char *iv = silc_cipher_get_iv(cipher);
1474   SilcUInt32 pc1, pc2;
1475
1476   /* Reset block counter */
1477   memset(iv + 12, 0, 4);
1478
1479   /* If IV Included flag, return the 64-bit IV for inclusion in packet */
1480   if (stream->iv_included) {
1481     /* Get new nonce */
1482     ret_iv[0] = silc_rng_get_byte_fast(stream->sc->engine->rng);
1483     ret_iv[1] = ret_iv[0] + iv[4];
1484     ret_iv[2] = ret_iv[0] ^ ret_iv[1];
1485     ret_iv[3] = ret_iv[0] + ret_iv[2];
1486
1487     /* Increment 32-bit packet counter */
1488     SILC_GET32_MSB(pc1, iv + 8);
1489     pc1++;
1490     SILC_PUT32_MSB(pc1, ret_iv + 4);
1491
1492     SILC_LOG_HEXDUMP(("IV"), ret_iv, 8);
1493
1494     /* Set new nonce to counter block */
1495     memcpy(iv + 4, ret_iv, 8);
1496   } else {
1497     /* Increment 64-bit packet counter */
1498     SILC_GET32_MSB(pc1, iv + 4);
1499     SILC_GET32_MSB(pc2, iv + 8);
1500     if (++pc2 == 0)
1501       ++pc1;
1502     SILC_PUT32_MSB(pc1, iv + 4);
1503     SILC_PUT32_MSB(pc2, iv + 8);
1504   }
1505
1506   SILC_LOG_HEXDUMP(("Counter Block"), iv, 16);
1507 }
1508
1509 /* Internal routine to assemble outgoing packet.  Assembles and encryptes
1510    the packet.  The silc_packet_stream_write needs to be called to send it
1511    after this returns TRUE. */
1512
1513 static inline SilcBool silc_packet_send_raw(SilcPacketStream stream,
1514                                             SilcPacketType type,
1515                                             SilcPacketFlags flags,
1516                                             SilcIdType src_id_type,
1517                                             unsigned char *src_id,
1518                                             SilcUInt32 src_id_len,
1519                                             SilcIdType dst_id_type,
1520                                             unsigned char *dst_id,
1521                                             SilcUInt32 dst_id_len,
1522                                             const unsigned char *data,
1523                                             SilcUInt32 data_len,
1524                                             SilcCipher cipher,
1525                                             SilcHmac hmac)
1526 {
1527   unsigned char tmppad[SILC_PACKET_MAX_PADLEN], iv[33], psn[4];
1528   int block_len = (cipher ? silc_cipher_get_block_len(cipher) : 0);
1529   int i, enclen, truelen, padlen = 0, ivlen = 0, psnlen = 0;
1530   SilcBool ctr;
1531   SilcBufferStruct packet;
1532
1533   SILC_LOG_DEBUG(("Sending packet %s (%d) flags %d, src %d dst %d, "
1534                   "data len %d", silc_get_packet_name(type), stream->send_psn,
1535                   flags, src_id_type, dst_id_type, data_len));
1536
1537   /* Get the true length of the packet. This is saved as payload length
1538      into the packet header.  This does not include the length of the
1539      padding. */
1540   data_len = SILC_PACKET_DATALEN(data_len, (SILC_PACKET_HEADER_LEN +
1541                                             src_id_len + dst_id_len));
1542   enclen = truelen = (data_len + SILC_PACKET_HEADER_LEN +
1543                       src_id_len + dst_id_len);
1544
1545   /* If using CTR mode, increment the counter */
1546   ctr = (cipher && silc_cipher_get_mode(cipher) == SILC_CIPHER_MODE_CTR);
1547   if (ctr) {
1548     silc_packet_send_ctr_increment(stream, cipher, iv + 1);
1549
1550     /* If IV is included, the SID, IV and sequence number is added to packet */
1551     if (stream->iv_included && cipher) {
1552       psnlen = sizeof(psn);
1553       ivlen = 8 + 1;
1554       iv[0] = stream->sid;
1555     }
1556   } else {
1557     /* If IV is included, the SID, IV and sequence number is added to packet */
1558     if (stream->iv_included && cipher) {
1559       psnlen = sizeof(psn);
1560       ivlen = block_len + 1;
1561       iv[0] = stream->sid;
1562       memcpy(iv + 1, silc_cipher_get_iv(cipher), block_len);
1563     }
1564   }
1565
1566   /* We automatically figure out the packet structure from the packet
1567      type and flags, and calculate correct length.  Private messages with
1568      private keys and channel messages are special packets as their
1569      payload is encrypted already. */
1570   if (type == SILC_PACKET_PRIVATE_MESSAGE &&
1571       flags & SILC_PACKET_FLAG_PRIVMSG_KEY) {
1572     /* Padding is calculated from header + IDs */
1573     if (!ctr)
1574       SILC_PACKET_PADLEN((SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
1575                           psnlen), block_len, padlen);
1576
1577     /* Length to encrypt, header + IDs + padding. */
1578     enclen = (SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
1579               padlen + psnlen);
1580
1581   } else if (type == SILC_PACKET_CHANNEL_MESSAGE) {
1582     if (stream->sc->engine->local_is_router && stream->is_router) {
1583       /* Channel messages between routers are encrypted as normal packets.
1584          Padding is calculated from true length of the packet. */
1585       if (!ctr)
1586         SILC_PACKET_PADLEN(truelen + psnlen, block_len, padlen);
1587
1588       enclen += padlen + psnlen;
1589     } else {
1590       /* Padding is calculated from header + IDs */
1591       if (!ctr)
1592         SILC_PACKET_PADLEN((SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
1593                             psnlen), block_len, padlen);
1594
1595       /* Length to encrypt, header + IDs + padding. */
1596       enclen = (SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len +
1597                 padlen + psnlen);
1598     }
1599   } else {
1600     /* Padding is calculated from true length of the packet */
1601     if (flags & SILC_PACKET_FLAG_LONG_PAD)
1602       SILC_PACKET_PADLEN_MAX(truelen + psnlen, block_len, padlen);
1603     else if (!ctr)
1604       SILC_PACKET_PADLEN(truelen + psnlen, block_len, padlen);
1605
1606     enclen += padlen + psnlen;
1607   }
1608
1609   /* Remove implementation specific flags */
1610   flags &= ~(SILC_PACKET_FLAG_LONG_PAD);
1611
1612   /* Get random padding */
1613   for (i = 0; i < padlen; i++) tmppad[i] =
1614     silc_rng_get_byte_fast(stream->sc->engine->rng);
1615
1616   silc_mutex_lock(stream->lock);
1617
1618   /* Get packet pointer from the outgoing buffer */
1619   if (silc_unlikely(!silc_packet_send_prepare(stream, truelen + padlen + ivlen
1620                                               + psnlen, hmac, &packet))) {
1621     silc_mutex_unlock(stream->lock);
1622     return FALSE;
1623   }
1624
1625   SILC_PUT32_MSB(stream->send_psn, psn);
1626
1627   /* Create the packet.  This creates the SILC header, adds padding, and
1628      the actual packet data. */
1629   i = silc_buffer_format(&packet,
1630                          SILC_STR_DATA(iv, ivlen),
1631                          SILC_STR_DATA(psn, psnlen),
1632                          SILC_STR_UI_SHORT(truelen),
1633                          SILC_STR_UI_CHAR(flags),
1634                          SILC_STR_UI_CHAR(type),
1635                          SILC_STR_UI_CHAR(padlen),
1636                          SILC_STR_UI_CHAR(0),
1637                          SILC_STR_UI_CHAR(src_id_len),
1638                          SILC_STR_UI_CHAR(dst_id_len),
1639                          SILC_STR_UI_CHAR(src_id_type),
1640                          SILC_STR_DATA(src_id, src_id_len),
1641                          SILC_STR_UI_CHAR(dst_id_type),
1642                          SILC_STR_DATA(dst_id, dst_id_len),
1643                          SILC_STR_DATA(tmppad, padlen),
1644                          SILC_STR_DATA(data, data_len),
1645                          SILC_STR_END);
1646   if (silc_unlikely(i < 0)) {
1647     silc_mutex_unlock(stream->lock);
1648     return FALSE;
1649   }
1650
1651   SILC_LOG_HEXDUMP(("Assembled packet, len %d", silc_buffer_len(&packet)),
1652                    silc_buffer_data(&packet), silc_buffer_len(&packet));
1653
1654   /* Encrypt the packet */
1655   if (silc_likely(cipher)) {
1656     SILC_LOG_DEBUG(("Encrypting packet"));
1657     silc_cipher_set_iv(cipher, NULL);
1658     if (silc_unlikely(!silc_cipher_encrypt(cipher, packet.data + ivlen,
1659                                            packet.data + ivlen, enclen,
1660                                            NULL))) {
1661       SILC_LOG_ERROR(("Packet encryption failed"));
1662       silc_mutex_unlock(stream->lock);
1663       return FALSE;
1664     }
1665   }
1666
1667   /* Compute HMAC */
1668   if (silc_likely(hmac)) {
1669     SilcUInt32 mac_len;
1670
1671     /* MAC is computed from the entire encrypted packet data, and put
1672        to the end of the packet. */
1673     silc_hmac_init(hmac);
1674     silc_hmac_update(hmac, psn, sizeof(psn));
1675     silc_hmac_update(hmac, packet.data, silc_buffer_len(&packet));
1676     silc_hmac_final(hmac, packet.tail, &mac_len);
1677     silc_buffer_pull_tail(&packet, mac_len);
1678     stream->send_psn++;
1679   }
1680
1681   return TRUE;
1682 }
1683
1684 /* Sends a packet */
1685
1686 SilcBool silc_packet_send(SilcPacketStream stream,
1687                           SilcPacketType type, SilcPacketFlags flags,
1688                           const unsigned char *data, SilcUInt32 data_len)
1689 {
1690   SilcBool ret;
1691
1692   ret = silc_packet_send_raw(stream, type, flags,
1693                              stream->src_id_type,
1694                              stream->src_id,
1695                              stream->src_id_len,
1696                              stream->dst_id_type,
1697                              stream->dst_id,
1698                              stream->dst_id_len,
1699                              data, data_len,
1700                              stream->send_key[0],
1701                              stream->send_hmac[0]);
1702
1703   /* Write the packet to the stream */
1704   return ret ? silc_packet_stream_write(stream, FALSE) : FALSE;
1705 }
1706
1707 /* Sends a packet, extended routine */
1708
1709 SilcBool silc_packet_send_ext(SilcPacketStream stream,
1710                               SilcPacketType type, SilcPacketFlags flags,
1711                               SilcIdType src_id_type, void *src_id,
1712                               SilcIdType dst_id_type, void *dst_id,
1713                               const unsigned char *data, SilcUInt32 data_len,
1714                               SilcCipher cipher, SilcHmac hmac)
1715 {
1716   unsigned char src_id_data[32], dst_id_data[32];
1717   SilcUInt32 src_id_len, dst_id_len;
1718   SilcBool ret;
1719
1720   if (src_id)
1721     if (!silc_id_id2str(src_id, src_id_type, src_id_data,
1722                         sizeof(src_id_data), &src_id_len))
1723       return FALSE;
1724   if (dst_id)
1725     if (!silc_id_id2str(dst_id, dst_id_type, dst_id_data,
1726                         sizeof(dst_id_data), &dst_id_len))
1727       return FALSE;
1728
1729   ret = silc_packet_send_raw(stream, type, flags,
1730                              src_id ? src_id_type : stream->src_id_type,
1731                              src_id ? src_id_data : stream->src_id,
1732                              src_id ? src_id_len : stream->src_id_len,
1733                              dst_id ? dst_id_type : stream->dst_id_type,
1734                              dst_id ? dst_id_data : stream->dst_id,
1735                              dst_id ? dst_id_len : stream->dst_id_len,
1736                              data, data_len,
1737                              cipher ? cipher : stream->send_key[0],
1738                              hmac ? hmac : stream->send_hmac[0]);
1739
1740   /* Write the packet to the stream */
1741   return ret ? silc_packet_stream_write(stream, FALSE) : FALSE;
1742 }
1743
1744 /* Sends packet after formatting the arguments to buffer */
1745
1746 SilcBool silc_packet_send_va(SilcPacketStream stream,
1747                              SilcPacketType type, SilcPacketFlags flags, ...)
1748 {
1749   SilcBufferStruct buf;
1750   SilcBool ret;
1751   va_list va;
1752
1753   va_start(va, flags);
1754
1755   memset(&buf, 0, sizeof(buf));
1756   if (silc_buffer_format_vp(&buf, va) < 0) {
1757     va_end(va);
1758     return FALSE;
1759   }
1760
1761   ret = silc_packet_send(stream, type, flags, silc_buffer_data(&buf),
1762                          silc_buffer_len(&buf));
1763
1764   silc_buffer_purge(&buf);
1765   va_end(va);
1766
1767   return ret;
1768 }
1769
1770 /* Sends packet after formatting the arguments to buffer, extended routine */
1771
1772 SilcBool silc_packet_send_va_ext(SilcPacketStream stream,
1773                                  SilcPacketType type, SilcPacketFlags flags,
1774                                  SilcIdType src_id_type, void *src_id,
1775                                  SilcIdType dst_id_type, void *dst_id,
1776                                  SilcCipher cipher, SilcHmac hmac, ...)
1777 {
1778   SilcBufferStruct buf;
1779   SilcBool ret;
1780   va_list va;
1781
1782   va_start(va, hmac);
1783
1784   memset(&buf, 0, sizeof(buf));
1785   if (silc_buffer_format_vp(&buf, va) < 0) {
1786     va_end(va);
1787     return FALSE;
1788   }
1789
1790   ret = silc_packet_send_ext(stream, type, flags, src_id_type, src_id,
1791                              dst_id_type, dst_id, silc_buffer_data(&buf),
1792                              silc_buffer_len(&buf), cipher, hmac);
1793
1794   silc_buffer_purge(&buf);
1795   va_end(va);
1796
1797   return TRUE;
1798 }
1799
1800 /***************************** Packet Receiving *****************************/
1801
1802 /* Checks MAC in the packet. Returns TRUE if MAC is Ok. */
1803
1804 static inline SilcBool silc_packet_check_mac(SilcHmac hmac,
1805                                              const unsigned char *data,
1806                                              SilcUInt32 data_len,
1807                                              const unsigned char *packet_mac,
1808                                              const unsigned char *packet_seq,
1809                                              SilcUInt32 sequence)
1810 {
1811   /* Check MAC */
1812   if (silc_likely(hmac)) {
1813     unsigned char mac[32], psn[4];
1814     SilcUInt32 mac_len;
1815
1816     SILC_LOG_DEBUG(("Verifying MAC"));
1817
1818     /* Compute HMAC of packet */
1819     silc_hmac_init(hmac);
1820
1821     if (!packet_seq) {
1822       SILC_PUT32_MSB(sequence, psn);
1823       silc_hmac_update(hmac, psn, 4);
1824     } else
1825       silc_hmac_update(hmac, packet_seq, 4);
1826
1827     silc_hmac_update(hmac, data, data_len);
1828     silc_hmac_final(hmac, mac, &mac_len);
1829
1830     /* Compare the MAC's */
1831     if (silc_unlikely(memcmp(packet_mac, mac, mac_len))) {
1832       SILC_LOG_DEBUG(("MAC failed"));
1833       return FALSE;
1834     }
1835
1836     SILC_LOG_DEBUG(("MAC is Ok"));
1837   }
1838
1839   return TRUE;
1840 }
1841
1842 /* Increments/sets counter when decrypting in counter mode. */
1843
1844 static inline void silc_packet_receive_ctr_increment(SilcPacketStream stream,
1845                                                      unsigned char *iv,
1846                                                      unsigned char *packet_iv)
1847 {
1848   SilcUInt32 pc1, pc2;
1849
1850   /* If IV Included flag, set the IV from packet to block counter. */
1851   if (stream->iv_included) {
1852     memcpy(iv + 4, packet_iv, 8);
1853   } else {
1854     /* Increment 64-bit packet counter. */
1855     SILC_GET32_MSB(pc1, iv + 4);
1856     SILC_GET32_MSB(pc2, iv + 8);
1857     if (++pc2 == 0)
1858       ++pc1;
1859     SILC_PUT32_MSB(pc1, iv + 4);
1860     SILC_PUT32_MSB(pc2, iv + 8);
1861   }
1862
1863   /* Reset block counter */
1864   memset(iv + 12, 0, 4);
1865
1866   SILC_LOG_HEXDUMP(("Counter Block"), iv, 16);
1867 }
1868
1869 /* Decrypts SILC packet.  Handles both normal and special packet decryption.
1870    Return 0 when packet is normal and 1 when it it special, -1 on error. */
1871
1872 static inline int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
1873                                       SilcUInt32 sequence, SilcBuffer buffer,
1874                                       SilcBool normal)
1875 {
1876   if (normal == TRUE) {
1877     if (silc_likely(cipher)) {
1878       /* Decrypt rest of the packet */
1879       SILC_LOG_DEBUG(("Decrypting the packet"));
1880       if (silc_unlikely(!silc_cipher_decrypt(cipher, buffer->data,
1881                                              buffer->data,
1882                                              silc_buffer_len(buffer), NULL)))
1883         return -1;
1884     }
1885     return 0;
1886
1887   } else {
1888     /* Decrypt rest of the header plus padding */
1889     if (silc_likely(cipher)) {
1890       SilcUInt16 len;
1891       SilcUInt32 block_len = silc_cipher_get_block_len(cipher);
1892
1893       SILC_LOG_DEBUG(("Decrypting the header"));
1894
1895       /* Padding length + src id len + dst id len + header length - 16
1896          bytes already decrypted, gives the rest of the encrypted packet */
1897       silc_buffer_push(buffer, block_len);
1898       len = (((SilcUInt8)buffer->data[4] + (SilcUInt8)buffer->data[6] +
1899               (SilcUInt8)buffer->data[7] + SILC_PACKET_HEADER_LEN) -
1900              block_len);
1901       silc_buffer_pull(buffer, block_len);
1902
1903       if (silc_unlikely(len > silc_buffer_len(buffer))) {
1904         SILC_LOG_ERROR(("Garbage in header of packet, bad packet length, "
1905                         "packet dropped"));
1906         return -1;
1907       }
1908       if (silc_unlikely(!silc_cipher_decrypt(cipher, buffer->data,
1909                                              buffer->data, len, NULL)))
1910         return -1;
1911     }
1912
1913     return 1;
1914   }
1915 }
1916
1917 /* Parses the packet. This is called when a whole packet is ready to be
1918    parsed. The buffer sent must be already decrypted before calling this
1919    function. */
1920
1921 static inline SilcBool silc_packet_parse(SilcPacket packet)
1922 {
1923   SilcBuffer buffer = &packet->buffer;
1924   SilcUInt8 padlen = (SilcUInt8)buffer->data[4];
1925   SilcUInt8 src_id_len, dst_id_len, src_id_type, dst_id_type;
1926   int ret;
1927
1928   SILC_LOG_DEBUG(("Parsing incoming packet"));
1929
1930   /* Parse the buffer.  This parses the SILC header of the packet. */
1931   ret = silc_buffer_unformat(buffer,
1932                              SILC_STR_ADVANCE,
1933                              SILC_STR_OFFSET(6),
1934                              SILC_STR_UI_CHAR(&src_id_len),
1935                              SILC_STR_UI_CHAR(&dst_id_len),
1936                              SILC_STR_UI_CHAR(&src_id_type),
1937                              SILC_STR_END);
1938   if (silc_unlikely(ret == -1)) {
1939     if (!packet->stream->udp &&
1940         !silc_socket_stream_is_udp(packet->stream->stream, NULL))
1941       SILC_LOG_ERROR(("Malformed packet header, packet dropped"));
1942     return FALSE;
1943   }
1944
1945   if (silc_unlikely(src_id_len > SILC_PACKET_MAX_ID_LEN ||
1946                     dst_id_len > SILC_PACKET_MAX_ID_LEN)) {
1947     if (!packet->stream->udp &&
1948         !silc_socket_stream_is_udp(packet->stream->stream, NULL))
1949       SILC_LOG_ERROR(("Bad ID lengths in packet (%d and %d)",
1950                       packet->src_id_len, packet->dst_id_len));
1951     return FALSE;
1952   }
1953
1954   ret = silc_buffer_unformat(buffer,
1955                              SILC_STR_ADVANCE,
1956                              SILC_STR_DATA(&packet->src_id, src_id_len),
1957                              SILC_STR_UI_CHAR(&dst_id_type),
1958                              SILC_STR_DATA(&packet->dst_id, dst_id_len),
1959                              SILC_STR_OFFSET(padlen),
1960                              SILC_STR_END);
1961   if (silc_unlikely(ret == -1)) {
1962     if (!packet->stream->udp &&
1963         !silc_socket_stream_is_udp(packet->stream->stream, NULL))
1964       SILC_LOG_ERROR(("Malformed packet header, packet dropped"));
1965     return FALSE;
1966   }
1967
1968   if (silc_unlikely(src_id_type > SILC_ID_CHANNEL ||
1969                     dst_id_type > SILC_ID_CHANNEL)) {
1970     if (!packet->stream->udp &&
1971         !silc_socket_stream_is_udp(packet->stream->stream, NULL))
1972       SILC_LOG_ERROR(("Bad ID types in packet (%d and %d)",
1973                       src_id_type, dst_id_type));
1974     return FALSE;
1975   }
1976
1977   packet->src_id_len = src_id_len;
1978   packet->dst_id_len = dst_id_len;
1979   packet->src_id_type = src_id_type;
1980   packet->dst_id_type = dst_id_type;
1981
1982   SILC_LOG_HEXDUMP(("Parsed packet, len %d", silc_buffer_headlen(buffer) +
1983                    silc_buffer_len(buffer)), buffer->head,
1984                    silc_buffer_headlen(buffer) + silc_buffer_len(buffer));
1985
1986   SILC_LOG_DEBUG(("Incoming packet type: %d (%s), flags %d", packet->type,
1987                   silc_get_packet_name(packet->type), packet->flags));
1988
1989   return TRUE;
1990 }
1991
1992 /* Dispatch packet to application.  Called with stream->lock locked.
1993    Returns FALSE if the stream was destroyed while dispatching a packet. */
1994
1995 static SilcBool silc_packet_dispatch(SilcPacket packet)
1996 {
1997   SilcPacketStream stream = packet->stream;
1998   SilcPacketProcess p;
1999   SilcBool default_sent = FALSE;
2000   SilcPacketType *pt;
2001
2002   /* Dispatch packet to all packet processors that want it */
2003
2004   if (silc_likely(!stream->process)) {
2005     /* Send to default processor as no others exist */
2006     SILC_LOG_DEBUG(("Dispatching packet to default callbacks"));
2007     silc_mutex_unlock(stream->lock);
2008     if (silc_unlikely(!stream->sc->engine->callbacks->
2009                       packet_receive(stream->sc->engine, stream, packet,
2010                                      stream->sc->engine->callback_context,
2011                                      stream->stream_context)))
2012       silc_packet_free(packet);
2013     silc_mutex_lock(stream->lock);
2014     return stream->destroyed == FALSE;
2015   }
2016
2017   silc_dlist_start(stream->process);
2018   while ((p = silc_dlist_get(stream->process)) != SILC_LIST_END) {
2019
2020     /* If priority is 0 or less, we send to default processor first
2021        because default processor has 0 priority */
2022     if (!default_sent && p->priority <= 0) {
2023       SILC_LOG_DEBUG(("Dispatching packet to default callbacks"));
2024       default_sent = TRUE;
2025       silc_mutex_unlock(stream->lock);
2026       if (stream->sc->engine->callbacks->
2027           packet_receive(stream->sc->engine, stream, packet,
2028                          stream->sc->engine->callback_context,
2029                          stream->stream_context)) {
2030         silc_mutex_lock(stream->lock);
2031         return stream->destroyed == FALSE;
2032       }
2033       silc_mutex_lock(stream->lock);
2034     }
2035
2036     /* Send to processor */
2037     if (!p->types) {
2038       /* Send all packet types */
2039       SILC_LOG_DEBUG(("Dispatching packet to %p callbacks", p->callbacks));
2040       silc_mutex_unlock(stream->lock);
2041       if (p->callbacks->packet_receive(stream->sc->engine, stream, packet,
2042                                        p->callback_context,
2043                                        stream->stream_context)) {
2044         silc_mutex_lock(stream->lock);
2045         return stream->destroyed == FALSE;
2046       }
2047       silc_mutex_lock(stream->lock);
2048     } else {
2049       /* Send specific types */
2050       for (pt = p->types; *pt; pt++) {
2051         if (*pt != packet->type)
2052           continue;
2053         SILC_LOG_DEBUG(("Dispatching packet to %p callbacks", p->callbacks));
2054         silc_mutex_unlock(stream->lock);
2055         if (p->callbacks->packet_receive(stream->sc->engine, stream, packet,
2056                                          p->callback_context,
2057                                          stream->stream_context)) {
2058           silc_mutex_lock(stream->lock);
2059           return stream->destroyed == FALSE;
2060         }
2061         silc_mutex_lock(stream->lock);
2062         break;
2063       }
2064     }
2065   }
2066
2067   if (!default_sent) {
2068     /* Send to default processor as it has not been sent yet */
2069     SILC_LOG_DEBUG(("Dispatching packet to default callbacks"));
2070     silc_mutex_unlock(stream->lock);
2071     if (stream->sc->engine->callbacks->
2072         packet_receive(stream->sc->engine, stream, packet,
2073                        stream->sc->engine->callback_context,
2074                        stream->stream_context)) {
2075       silc_mutex_lock(stream->lock);
2076       return stream->destroyed == FALSE;
2077     }
2078     silc_mutex_lock(stream->lock);
2079   }
2080
2081   /* If we got here, no one wanted the packet, so drop it */
2082   silc_packet_free(packet);
2083   return stream->destroyed == FALSE;
2084 }
2085
2086 /* Process incoming data and parse packets.  Called with stream->lock
2087    locked. */
2088
2089 static void silc_packet_read_process(SilcPacketStream stream)
2090 {
2091   SilcBuffer inbuf;
2092   SilcCipher cipher;
2093   SilcHmac hmac;
2094   SilcPacket packet;
2095   SilcUInt8 sid;
2096   SilcUInt16 packetlen;
2097   SilcUInt32 paddedlen, mac_len, block_len, ivlen, psnlen;
2098   unsigned char tmp[SILC_PACKET_MIN_HEADER_LEN], *header;
2099   unsigned char iv[SILC_CIPHER_MAX_IV_SIZE], *packet_seq = NULL;
2100   SilcBool normal;
2101   int ret;
2102
2103   /* Get inbuf.  If there is already some data for this stream in the buffer
2104      we already have it.  Otherwise get the current one from list, it will
2105      include the data. */
2106   inbuf = stream->inbuf;
2107   if (!inbuf) {
2108     silc_dlist_start(stream->sc->inbufs);
2109     inbuf = silc_dlist_get(stream->sc->inbufs);
2110   }
2111
2112   /* Parse the packets from the data */
2113   while (silc_buffer_len(inbuf) > 0) {
2114     ivlen = psnlen = 0;
2115     cipher = stream->receive_key[0];
2116     hmac = stream->receive_hmac[0];
2117     normal = FALSE;
2118
2119     if (silc_unlikely(silc_buffer_len(inbuf) <
2120                       (stream->iv_included ? SILC_PACKET_MIN_HEADER_LEN_IV :
2121                        SILC_PACKET_MIN_HEADER_LEN))) {
2122       SILC_LOG_DEBUG(("Partial packet in queue, waiting for the rest"));
2123       silc_dlist_del(stream->sc->inbufs, inbuf);
2124       stream->inbuf = inbuf;
2125       return;
2126     }
2127
2128     if (silc_likely(hmac))
2129       mac_len = silc_hmac_len(hmac);
2130     else
2131       mac_len = 0;
2132
2133     /* Decrypt first block of the packet to get the length field out */
2134     if (silc_likely(cipher)) {
2135       block_len = silc_cipher_get_block_len(cipher);
2136
2137       if (stream->iv_included) {
2138         /* SID, IV and sequence number is included in the ciphertext */
2139         sid = (SilcUInt8)inbuf->data[0];
2140
2141         if (silc_cipher_get_mode(cipher) == SILC_CIPHER_MODE_CTR) {
2142           /* Set the CTR mode IV from packet to counter block */
2143           memcpy(iv, silc_cipher_get_iv(cipher), block_len);
2144           silc_packet_receive_ctr_increment(stream, iv, inbuf->data + 1);
2145           ivlen = 8 + 1;
2146         } else {
2147           /* Get IV from packet */
2148           memcpy(iv, inbuf->data + 1, block_len);
2149           ivlen = block_len + 1;
2150         }
2151         psnlen = 4;
2152
2153         /* Check SID, and get correct decryption key */
2154         if (sid != stream->sid) {
2155           /* If SID is recent get the previous key and use it */
2156           if (sid > 0 && stream->sid > 0 && stream->sid - 1 == sid &&
2157               stream->receive_key[1] && !stream->receive_hmac[1]) {
2158             cipher = stream->receive_key[1];
2159             hmac = stream->receive_hmac[1];
2160           } else {
2161             /* The SID is unknown, drop rest of the data in buffer */
2162             SILC_LOG_DEBUG(("Unknown Security ID %d in packet, expected %d",
2163                             sid, stream->sid));
2164             silc_mutex_unlock(stream->lock);
2165             SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_UNKNOWN_SID);
2166             silc_mutex_lock(stream->lock);
2167             goto out;
2168           }
2169         }
2170       } else {
2171         memcpy(iv, silc_cipher_get_iv(cipher), block_len);
2172
2173         /* If using CTR mode, increment the counter */
2174         if (silc_cipher_get_mode(cipher) == SILC_CIPHER_MODE_CTR)
2175           silc_packet_receive_ctr_increment(stream, iv, NULL);
2176       }
2177
2178       if (silc_cipher_get_mode(cipher) == SILC_CIPHER_MODE_CTR)
2179         silc_cipher_set_iv(cipher, NULL);
2180       silc_cipher_decrypt(cipher, inbuf->data + ivlen, tmp, block_len, iv);
2181
2182       header = tmp;
2183       if (stream->iv_included) {
2184         /* Take sequence number from packet */
2185         packet_seq = header;
2186         header += 4;
2187       }
2188     } else {
2189       /* Unencrypted packet */
2190       block_len = SILC_PACKET_MIN_HEADER_LEN;
2191       header = inbuf->data;
2192     }
2193
2194     /* Get packet length and full packet length with padding */
2195     SILC_PACKET_LENGTH(header, packetlen, paddedlen);
2196
2197     /* Sanity checks */
2198     if (silc_unlikely(packetlen < SILC_PACKET_MIN_LEN)) {
2199       if (!stream->udp && !silc_socket_stream_is_udp(stream->stream, NULL))
2200         SILC_LOG_ERROR(("Received too short packet"));
2201       silc_mutex_unlock(stream->lock);
2202       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MALFORMED);
2203       silc_mutex_lock(stream->lock);
2204       memset(tmp, 0, sizeof(tmp));
2205       goto out;
2206     }
2207
2208     if (silc_buffer_len(inbuf) < paddedlen + ivlen + mac_len) {
2209       SILC_LOG_DEBUG(("Received partial packet, waiting for the rest "
2210                       "(%d bytes)",
2211                       paddedlen + mac_len - silc_buffer_len(inbuf)));
2212       memset(tmp, 0, sizeof(tmp));
2213       silc_dlist_del(stream->sc->inbufs, inbuf);
2214       stream->inbuf = inbuf;
2215       return;
2216     }
2217
2218     /* Check MAC of the packet */
2219     if (silc_unlikely(!silc_packet_check_mac(hmac, inbuf->data,
2220                                              paddedlen + ivlen,
2221                                              inbuf->data + ivlen +
2222                                              paddedlen, packet_seq,
2223                                              stream->receive_psn))) {
2224       silc_mutex_unlock(stream->lock);
2225       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MAC_FAILED);
2226       silc_mutex_lock(stream->lock);
2227       memset(tmp, 0, sizeof(tmp));
2228       goto out;
2229     }
2230
2231     /* Get packet */
2232     packet = silc_packet_alloc(stream->sc->engine);
2233     if (silc_unlikely(!packet)) {
2234       silc_mutex_unlock(stream->lock);
2235       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_NO_MEMORY);
2236       silc_mutex_lock(stream->lock);
2237       memset(tmp, 0, sizeof(tmp));
2238       goto out;
2239     }
2240     packet->stream = stream;
2241
2242     /* Allocate more space to packet buffer, if needed */
2243     if (silc_unlikely(silc_buffer_truelen(&packet->buffer) < paddedlen)) {
2244       if (!silc_buffer_realloc(&packet->buffer,
2245                                silc_buffer_truelen(&packet->buffer) +
2246                                (paddedlen -
2247                                 silc_buffer_truelen(&packet->buffer)))) {
2248         silc_mutex_unlock(stream->lock);
2249         SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_NO_MEMORY);
2250         silc_mutex_lock(stream->lock);
2251         silc_packet_free(packet);
2252         memset(tmp, 0, sizeof(tmp));
2253         goto out;
2254       }
2255     }
2256
2257     /* Parse packet header */
2258     packet->flags = (SilcPacketFlags)header[2];
2259     packet->type = (SilcPacketType)header[3];
2260
2261     if (stream->sc->engine->local_is_router) {
2262       if (packet->type == SILC_PACKET_PRIVATE_MESSAGE &&
2263           (packet->flags & SILC_PACKET_FLAG_PRIVMSG_KEY))
2264         normal = FALSE;
2265       else if (packet->type != SILC_PACKET_CHANNEL_MESSAGE ||
2266                (packet->type == SILC_PACKET_CHANNEL_MESSAGE &&
2267                 stream->is_router == TRUE))
2268         normal = TRUE;
2269     } else {
2270       if (packet->type == SILC_PACKET_PRIVATE_MESSAGE &&
2271           (packet->flags & SILC_PACKET_FLAG_PRIVMSG_KEY))
2272         normal = FALSE;
2273       else if (packet->type != SILC_PACKET_CHANNEL_MESSAGE)
2274         normal = TRUE;
2275     }
2276
2277     SILC_LOG_HEXDUMP(("Incoming packet (%d) len %d",
2278                       stream->receive_psn, paddedlen + ivlen + mac_len),
2279                      inbuf->data, paddedlen + ivlen + mac_len);
2280
2281     /* Put the decrypted part, and rest of the encrypted data, and decrypt */
2282     silc_buffer_pull_tail(&packet->buffer, paddedlen);
2283     silc_buffer_put(&packet->buffer, header, block_len - psnlen);
2284     silc_buffer_pull(&packet->buffer, block_len - psnlen);
2285     silc_buffer_put(&packet->buffer, (inbuf->data + ivlen +
2286                                       psnlen + (block_len - psnlen)),
2287                     paddedlen - ivlen - psnlen - (block_len - psnlen));
2288     if (silc_likely(cipher)) {
2289       silc_cipher_set_iv(cipher, iv);
2290       ret = silc_packet_decrypt(cipher, hmac, stream->receive_psn,
2291                                 &packet->buffer, normal);
2292       if (silc_unlikely(ret < 0)) {
2293         silc_mutex_unlock(stream->lock);
2294         SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_DECRYPTION_FAILED);
2295         silc_mutex_lock(stream->lock);
2296         silc_packet_free(packet);
2297         memset(tmp, 0, sizeof(tmp));
2298         goto out;
2299       }
2300
2301       stream->receive_psn++;
2302     }
2303     silc_buffer_push(&packet->buffer, block_len);
2304
2305     /* Pull the packet from inbuf thus we'll get the next one in the inbuf. */
2306     silc_buffer_pull(inbuf, paddedlen + mac_len);
2307
2308     /* Parse the packet */
2309     if (silc_unlikely(!silc_packet_parse(packet))) {
2310       silc_mutex_unlock(stream->lock);
2311       SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MALFORMED);
2312       silc_mutex_lock(stream->lock);
2313       silc_packet_free(packet);
2314       memset(tmp, 0, sizeof(tmp));
2315       goto out;
2316     }
2317
2318     /* Dispatch the packet to application */
2319     if (!silc_packet_dispatch(packet))
2320       break;
2321   }
2322
2323  out:
2324   /* Add inbuf back to free list, if we owned it. */
2325   if (stream->inbuf) {
2326     silc_dlist_add(stream->sc->inbufs, inbuf);
2327     stream->inbuf = NULL;
2328   }
2329
2330   silc_buffer_reset(inbuf);
2331 }
2332
2333 /****************************** Packet Waiting ******************************/
2334
2335 /* Packet wait receive callback */
2336 static SilcBool
2337 silc_packet_wait_packet_receive(SilcPacketEngine engine,
2338                                 SilcPacketStream stream,
2339                                 SilcPacket packet,
2340                                 void *callback_context,
2341                                 void *stream_context);
2342
2343 /* Packet waiting callbacks */
2344 static SilcPacketCallbacks silc_packet_wait_cbs =
2345 {
2346   silc_packet_wait_packet_receive, NULL, NULL
2347 };
2348
2349 /* Packet waiting context */
2350 typedef struct {
2351   SilcMutex wait_lock;
2352   SilcCond wait_cond;
2353   SilcList packet_queue;
2354   unsigned char id[28];
2355   unsigned int id_type     : 2;
2356   unsigned int id_len      : 5;
2357   unsigned int stopped     : 1;
2358 } *SilcPacketWait;
2359
2360 /* Packet wait receive callback */
2361
2362 static SilcBool
2363 silc_packet_wait_packet_receive(SilcPacketEngine engine,
2364                                 SilcPacketStream stream,
2365                                 SilcPacket packet,
2366                                 void *callback_context,
2367                                 void *stream_context)
2368 {
2369   SilcPacketWait pw = callback_context;
2370
2371   /* If source ID is specified check for it */
2372   if (pw->id_len) {
2373     if (pw->id_type != packet->src_id_type ||
2374         memcmp(pw->id, packet->src_id, pw->id_len))
2375       return FALSE;
2376   }
2377
2378   /* Signal the waiting thread for a new packet */
2379   silc_mutex_lock(pw->wait_lock);
2380
2381   if (silc_unlikely(pw->stopped)) {
2382     silc_mutex_unlock(pw->wait_lock);
2383     return FALSE;
2384   }
2385
2386   silc_list_add(pw->packet_queue, packet);
2387   silc_cond_broadcast(pw->wait_cond);
2388
2389   silc_mutex_unlock(pw->wait_lock);
2390
2391   return TRUE;
2392 }
2393
2394 /* Initialize packet waiting */
2395
2396 void *silc_packet_wait_init(SilcPacketStream stream,
2397                             const SilcID *source_id, ...)
2398 {
2399   SilcPacketWait pw;
2400   SilcBool ret;
2401   va_list ap;
2402
2403   pw = silc_calloc(1, sizeof(*pw));
2404   if (!pw)
2405     return NULL;
2406
2407   /* Allocate mutex and conditional variable */
2408   if (!silc_mutex_alloc(&pw->wait_lock)) {
2409     silc_free(pw);
2410     return NULL;
2411   }
2412   if (!silc_cond_alloc(&pw->wait_cond)) {
2413     silc_mutex_free(pw->wait_lock);
2414     silc_free(pw);
2415     return NULL;
2416   }
2417
2418   /* Link to the packet stream for the requested packet types */
2419   va_start(ap, source_id);
2420   ret = silc_packet_stream_link_va(stream, &silc_packet_wait_cbs, pw,
2421                                    10000000, ap);
2422   va_end(ap);
2423   if (!ret) {
2424     silc_cond_free(pw->wait_cond);
2425     silc_mutex_free(pw->wait_lock);
2426     silc_free(pw);
2427     return NULL;
2428   }
2429
2430   /* Initialize packet queue */
2431   silc_list_init(pw->packet_queue, struct SilcPacketStruct, next);
2432
2433   if (source_id) {
2434     SilcUInt32 id_len;
2435     silc_id_id2str(SILC_ID_GET_ID(*source_id), source_id->type, pw->id,
2436                    sizeof(pw->id), &id_len);
2437     pw->id_type = source_id->type;
2438     pw->id_len = id_len;
2439   }
2440
2441   return (void *)pw;
2442 }
2443
2444 /* Uninitialize packet waiting */
2445
2446 void silc_packet_wait_uninit(void *waiter, SilcPacketStream stream)
2447 {
2448   SilcPacketWait pw = waiter;
2449   SilcPacket packet;
2450
2451   /* Signal any threads to stop waiting */
2452   silc_mutex_lock(pw->wait_lock);
2453   pw->stopped = TRUE;
2454   silc_cond_broadcast(pw->wait_cond);
2455   silc_mutex_unlock(pw->wait_lock);
2456   silc_thread_yield();
2457
2458   /* Re-acquire lock and free resources */
2459   silc_mutex_lock(pw->wait_lock);
2460   silc_packet_stream_unlink(stream, &silc_packet_wait_cbs, pw);
2461
2462   /* Free any remaining packets */
2463   silc_list_start(pw->packet_queue);
2464   while ((packet = silc_list_get(pw->packet_queue)) != SILC_LIST_END)
2465     silc_packet_free(packet);
2466
2467   silc_mutex_unlock(pw->wait_lock);
2468   silc_cond_free(pw->wait_cond);
2469   silc_mutex_free(pw->wait_lock);
2470   silc_free(pw);
2471 }
2472
2473 /* Blocks thread until a packet has been received. */
2474
2475 int silc_packet_wait(void *waiter, int timeout, SilcPacket *return_packet)
2476 {
2477   SilcPacketWait pw = waiter;
2478   SilcBool ret = FALSE;
2479
2480   silc_mutex_lock(pw->wait_lock);
2481
2482   /* Wait here until packet has arrived */
2483   while (silc_list_count(pw->packet_queue) == 0) {
2484     if (silc_unlikely(pw->stopped)) {
2485       silc_mutex_unlock(pw->wait_lock);
2486       return -1;
2487     }
2488     ret = silc_cond_timedwait(pw->wait_cond, pw->wait_lock, timeout);
2489   }
2490
2491   /* Return packet */
2492   silc_list_start(pw->packet_queue);
2493   *return_packet = silc_list_get(pw->packet_queue);
2494   silc_list_del(pw->packet_queue, *return_packet);
2495
2496   silc_mutex_unlock(pw->wait_lock);
2497
2498   return ret == TRUE ? 1 : 0;
2499 }
2500
2501 /************************** Packet Stream Wrapper ***************************/
2502
2503 /* Packet stream wrapper receive callback */
2504 static SilcBool
2505 silc_packet_wrap_packet_receive(SilcPacketEngine engine,
2506                                 SilcPacketStream stream,
2507                                 SilcPacket packet,
2508                                 void *callback_context,
2509                                 void *stream_context);
2510
2511 const SilcStreamOps silc_packet_stream_ops;
2512
2513 /* Packet stream wrapper context */
2514 typedef struct {
2515   const SilcStreamOps *ops;
2516   SilcPacketStream stream;
2517   SilcMutex lock;
2518   void *waiter;                   /* Waiter context in blocking mode */
2519   SilcPacketWrapCoder coder;
2520   void *coder_context;
2521   SilcBuffer encbuf;
2522   SilcStreamNotifier callback;
2523   void *context;
2524   SilcList in_queue;
2525   SilcPacketType type;
2526   SilcPacketFlags flags;
2527   unsigned int closed        : 1;
2528   unsigned int blocking      : 1;
2529   unsigned int read_more     : 1;
2530 } *SilcPacketWrapperStream;
2531
2532 /* Packet wrapper callbacks */
2533 static SilcPacketCallbacks silc_packet_wrap_cbs =
2534 {
2535   silc_packet_wrap_packet_receive, NULL, NULL
2536 };
2537
2538 /* Packet stream wrapper receive callback, non-blocking mode */
2539
2540 static SilcBool
2541 silc_packet_wrap_packet_receive(SilcPacketEngine engine,
2542                                 SilcPacketStream stream,
2543                                 SilcPacket packet,
2544                                 void *callback_context,
2545                                 void *stream_context)
2546 {
2547   SilcPacketWrapperStream pws = callback_context;
2548
2549   if (pws->closed || !pws->callback)
2550     return FALSE;
2551
2552   silc_mutex_lock(pws->lock);
2553   silc_list_add(pws->in_queue, packet);
2554   silc_mutex_unlock(pws->lock);
2555
2556   /* Call notifier callback */
2557   pws->callback((SilcStream)pws, SILC_STREAM_CAN_READ, pws->context);
2558
2559   return TRUE;
2560 }
2561
2562 /* Task callback to notify more data is available for reading */
2563
2564 SILC_TASK_CALLBACK(silc_packet_wrap_read_more)
2565 {
2566   SilcPacketWrapperStream pws = context;
2567
2568   if (pws->closed || !pws->callback)
2569     return;
2570
2571   /* Call notifier callback */
2572   pws->callback((SilcStream)pws, SILC_STREAM_CAN_READ, pws->context);
2573 }
2574
2575 /* Read SILC packet */
2576
2577 int silc_packet_wrap_read(SilcStream stream, unsigned char *buf,
2578                           SilcUInt32 buf_len)
2579 {
2580   SilcPacketWrapperStream pws = stream;
2581   SilcPacket packet;
2582   SilcBool read_more = FALSE;
2583   int len;
2584
2585   if (pws->closed)
2586     return -2;
2587
2588   if (pws->blocking) {
2589     /* Block until packet is received */
2590     if ((silc_packet_wait(pws->waiter, 0, &packet)) < 0)
2591       return -2;
2592     if (pws->closed)
2593       return -2;
2594   } else {
2595     /* Non-blocking mode */
2596     silc_mutex_lock(pws->lock);
2597     if (!silc_list_count(pws->in_queue)) {
2598       silc_mutex_unlock(pws->lock);
2599       return -1;
2600     }
2601
2602     silc_list_start(pws->in_queue);
2603     packet = silc_list_get(pws->in_queue);
2604     silc_list_del(pws->in_queue, packet);
2605     silc_mutex_unlock(pws->lock);
2606   }
2607
2608   /* Call decoder if set */
2609   if (pws->coder && !pws->read_more)
2610     pws->coder(stream, SILC_STREAM_CAN_READ, &packet->buffer,
2611                pws->coder_context);
2612
2613   len = silc_buffer_len(&packet->buffer);
2614   if (len > buf_len) {
2615     len = buf_len;
2616     read_more = TRUE;
2617   }
2618
2619   /* Read data */
2620   memcpy(buf, packet->buffer.data, len);
2621
2622   if (read_more && !pws->blocking) {
2623     /* More data will be available (in blocking mode not supported). */
2624     silc_buffer_pull(&packet->buffer, len);
2625     silc_list_insert(pws->in_queue, NULL, packet);
2626     silc_schedule_task_add_timeout(pws->stream->sc->schedule,
2627                                    silc_packet_wrap_read_more, pws, 0, 0);
2628     pws->read_more = TRUE;
2629     return len;
2630   }
2631
2632   pws->read_more = FALSE;
2633   silc_packet_free(packet);
2634   return len;
2635 }
2636
2637 /* Write SILC packet */
2638
2639 int silc_packet_wrap_write(SilcStream stream, const unsigned char *data,
2640                            SilcUInt32 data_len)
2641 {
2642   SilcPacketWrapperStream pws = stream;
2643   SilcBool ret = FALSE;
2644
2645   /* Call encoder if set */
2646   if (pws->coder) {
2647     silc_buffer_reset(pws->encbuf);
2648     ret = pws->coder(stream, SILC_STREAM_CAN_WRITE, pws->encbuf,
2649                      pws->coder_context);
2650   }
2651
2652   /* Send the SILC packet */
2653   if (ret) {
2654     if (!silc_packet_send_va(pws->stream, pws->type, pws->flags,
2655                              SILC_STR_DATA(silc_buffer_data(pws->encbuf),
2656                                            silc_buffer_len(pws->encbuf)),
2657                              SILC_STR_DATA(data, data_len),
2658                              SILC_STR_END))
2659       return -2;
2660   } else {
2661     if (!silc_packet_send(pws->stream, pws->type, pws->flags, data, data_len))
2662       return -2;
2663   }
2664
2665   return data_len;
2666 }
2667
2668 /* Close stream */
2669
2670 SilcBool silc_packet_wrap_close(SilcStream stream)
2671 {
2672   SilcPacketWrapperStream pws = stream;
2673
2674   if (pws->closed)
2675     return TRUE;
2676
2677   if (pws->blocking) {
2678     /* Close packet waiter */
2679     silc_packet_wait_uninit(pws->waiter, pws->stream);
2680   } else {
2681     /* Unlink */
2682     if (pws->callback)
2683       silc_packet_stream_unlink(pws->stream, &silc_packet_wrap_cbs, pws);
2684   }
2685   pws->closed = TRUE;
2686
2687   return TRUE;
2688 }
2689
2690 /* Destroy wrapper stream */
2691
2692 void silc_packet_wrap_destroy(SilcStream stream)
2693
2694 {
2695   SilcPacketWrapperStream pws = stream;
2696   SilcPacket packet;
2697
2698   SILC_LOG_DEBUG(("Destroying wrapped packet stream %p", pws));
2699
2700   silc_stream_close(stream);
2701   silc_list_start(pws->in_queue);
2702   while ((packet = silc_list_get(pws->in_queue)))
2703     silc_packet_free(packet);
2704   if (pws->lock)
2705     silc_mutex_free(pws->lock);
2706   if (pws->encbuf)
2707     silc_buffer_free(pws->encbuf);
2708   silc_packet_stream_unref(pws->stream);
2709
2710   silc_free(pws);
2711 }
2712
2713 /* Link stream to receive packets */
2714
2715 SilcBool silc_packet_wrap_notifier(SilcStream stream,
2716                                    SilcSchedule schedule,
2717                                    SilcStreamNotifier callback,
2718                                    void *context)
2719 {
2720   SilcPacketWrapperStream pws = stream;
2721
2722   if (pws->closed || pws->blocking)
2723     return FALSE;
2724
2725   /* Link to receive packets */
2726   if (callback)
2727     silc_packet_stream_link(pws->stream, &silc_packet_wrap_cbs, pws,
2728                             100000, pws->type, -1);
2729   else
2730     silc_packet_stream_unlink(pws->stream, &silc_packet_wrap_cbs, pws);
2731
2732   pws->callback = callback;
2733   pws->context = context;
2734
2735   return TRUE;
2736 }
2737
2738 /* Return schedule */
2739
2740 SilcSchedule silc_packet_wrap_get_schedule(SilcStream stream)
2741 {
2742   return NULL;
2743 }
2744
2745 /* Wraps packet stream into SilcStream. */
2746
2747 SilcStream silc_packet_stream_wrap(SilcPacketStream stream,
2748                                    SilcPacketType type,
2749                                    SilcPacketFlags flags,
2750                                    SilcBool blocking_mode,
2751                                    SilcPacketWrapCoder coder,
2752                                    void *context)
2753 {
2754   SilcPacketWrapperStream pws;
2755
2756   pws = silc_calloc(1, sizeof(*pws));
2757   if (!pws)
2758     return NULL;
2759
2760   SILC_LOG_DEBUG(("Wrapping packet stream %p to stream %p", stream, pws));
2761
2762   pws->ops = &silc_packet_stream_ops;
2763   pws->stream = stream;
2764   pws->type = type;
2765   pws->flags = flags;
2766   pws->blocking = blocking_mode;
2767   pws->coder = coder;
2768   pws->coder_context = context;
2769
2770   /* Allocate small amount for encoder buffer. */
2771   if (pws->coder)
2772     pws->encbuf = silc_buffer_alloc(8);
2773
2774   if (pws->blocking) {
2775     /* Blocking mode.  Use packet waiter to do the thing. */
2776     pws->waiter = silc_packet_wait_init(pws->stream, NULL, pws->type, -1);
2777     if (!pws->waiter) {
2778       silc_free(pws);
2779       return NULL;
2780     }
2781   } else {
2782     /* Non-blocking mode */
2783     silc_mutex_alloc(&pws->lock);
2784     silc_list_init(pws->in_queue, struct SilcPacketStruct, next);
2785   }
2786
2787   silc_packet_stream_ref(stream);
2788
2789   return (SilcStream)pws;
2790 }
2791
2792 const SilcStreamOps silc_packet_stream_ops =
2793 {
2794   silc_packet_wrap_read,
2795   silc_packet_wrap_write,
2796   silc_packet_wrap_close,
2797   silc_packet_wrap_destroy,
2798   silc_packet_wrap_notifier,
2799   silc_packet_wrap_get_schedule,
2800 };