5 Author: Pekka Riikonen <priikone@silcnet.org>
7 Copyright (C) 1997 - 2001 Pekka Riikonen
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.
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.
20 * Created: Fri Jul 25 18:52:14 1997
24 #include "silcincludes.h"
26 /******************************************************************************
28 Packet Sending Routines
30 ******************************************************************************/
32 /* Actually sends the packet. This flushes the connections outgoing data
33 buffer. If data is sent directly to the network this returns the bytes
34 written, if error occured this returns -1 and if the data could not
35 be written directly to the network at this time this returns -2, in
36 which case the data should be queued by the caller and sent at some
37 later time. If `force_send' is TRUE this attempts to write the data
38 directly to the network, if FALSE, this returns -2. */
40 int silc_packet_send(SilcSocketConnection sock, bool force_send)
42 SILC_LOG_DEBUG(("Sending packet to %s:%d [%s]", sock->hostname,
44 (sock->type == SILC_SOCKET_TYPE_UNKNOWN ? "Unknown" :
45 sock->type == SILC_SOCKET_TYPE_CLIENT ? "Client" :
46 sock->type == SILC_SOCKET_TYPE_SERVER ? "Server" :
49 /* Send now if forced to do so */
50 if (force_send == TRUE) {
53 SILC_LOG_DEBUG(("Forcing packet send, packet sent immediately"));
55 /* Write to network */
56 ret = silc_socket_write(sock);
59 SILC_LOG_ERROR(("Error sending packet, dropped: %s",
65 SILC_LOG_DEBUG(("Could not force the send, packet put to queue"));
68 SILC_LOG_DEBUG(("Packet in queue"));
73 /* Encrypts a packet. This also creates HMAC of the packet before
74 encryption and adds the HMAC at the end of the buffer. This assumes
75 that there is enough free space at the end of the buffer to add the
76 computed HMAC. This is the normal way of encrypting packets, if some
77 other process of HMAC computing and encryption is needed this function
80 void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac, SilcUInt32 sequence,
81 SilcBuffer buffer, SilcUInt32 len)
83 unsigned char mac[32];
86 /* Compute HMAC. This assumes that HMAC is created from the entire
87 data area thus this uses the length found in buffer, not the length
93 SILC_PUT32_MSB(sequence, psn);
94 silc_hmac_update(hmac, psn, 4);
95 silc_hmac_update(hmac, buffer->data, buffer->len);
96 silc_hmac_final(hmac, mac, &mac_len);
97 silc_buffer_put_tail(buffer, mac, mac_len);
98 memset(mac, 0, sizeof(mac));
101 /* Encrypt the data area of the packet. */
103 SILC_LOG_DEBUG(("Encrypting packet, cipher %s, len %d",
104 cipher->cipher->name, len));
105 silc_cipher_encrypt(cipher, buffer->data, buffer->data, len, cipher->iv);
108 /* Pull the HMAC into the visible data area in the buffer */
110 silc_buffer_pull_tail(buffer, mac_len);
113 /* Assembles a new packet to be ready for send out. The buffer sent as
114 argument must include the data to be sent and it must not be encrypted.
115 The packet also must have enough free space so that the SILC header
116 and padding maybe added to the packet. The packet is encrypted after
117 this function has returned.
119 The buffer sent as argument should be something like following:
121 --------------------------------------------
122 | head | data | tail |
123 --------------------------------------------
127 So that the SILC header and 1 - 16 bytes of padding can fit to
128 the buffer. After assembly the buffer might look like this:
130 --------------------------------------------
132 --------------------------------------------
134 Start of assembled packet
136 Packet construct is as follows:
139 2 bytes Payload length
142 1 byte Padding length
144 1 bytes Source ID Length
145 1 bytes Destination ID Length
146 1 byte Source ID Type
148 1 byte Destination ID Type
149 n bytes Destination ID
155 All fields in the packet will be authenticated by MAC. The MAC is
156 not computed here, it must be computed separately before encrypting
161 void silc_packet_assemble(SilcPacketContext *ctx, SilcCipher cipher)
163 unsigned char tmppad[SILC_PACKET_MAX_PADLEN];
164 int block_len = cipher ? silc_cipher_get_block_len(cipher) : 0;
167 SILC_LOG_DEBUG(("Assembling outgoing packet"));
169 /* Get the true length of the packet. This is saved as payload length
170 into the packet header. This does not include the length of the
173 ctx->truelen = ctx->buffer->len + SILC_PACKET_HEADER_LEN +
174 ctx->src_id_len + ctx->dst_id_len;
176 /* Calculate the length of the padding. The padding is calculated from
177 the data that will be encrypted. */
180 ctx->padlen = SILC_PACKET_PADLEN_MAX(ctx->truelen);
182 ctx->padlen = SILC_PACKET_PADLEN(ctx->truelen, block_len);
185 /* Put the start of the data section to the right place. */
186 silc_buffer_push(ctx->buffer, SILC_PACKET_HEADER_LEN +
187 ctx->src_id_len + ctx->dst_id_len + ctx->padlen);
189 /* Get random padding */
191 for (i = 0; i < ctx->padlen; i++) tmppad[i] =
192 silc_rng_global_get_byte_fast();
194 /* XXX: For testing - to be removed */
195 memset(tmppad, 65, sizeof(tmppad));
198 /* Create the packet. This creates the SILC header and adds padding,
199 rest of the buffer remains as it is. */
200 silc_buffer_format(ctx->buffer,
201 SILC_STR_UI_SHORT(ctx->truelen),
202 SILC_STR_UI_CHAR(ctx->flags),
203 SILC_STR_UI_CHAR(ctx->type),
204 SILC_STR_UI_CHAR(ctx->padlen),
206 SILC_STR_UI_CHAR(ctx->src_id_len),
207 SILC_STR_UI_CHAR(ctx->dst_id_len),
208 SILC_STR_UI_CHAR(ctx->src_id_type),
209 SILC_STR_UI_XNSTRING(ctx->src_id, ctx->src_id_len),
210 SILC_STR_UI_CHAR(ctx->dst_id_type),
211 SILC_STR_UI_XNSTRING(ctx->dst_id, ctx->dst_id_len),
212 SILC_STR_UI_XNSTRING(tmppad, ctx->padlen),
215 SILC_LOG_HEXDUMP(("Assembled packet, len %d", ctx->buffer->len),
216 ctx->buffer->data, ctx->buffer->len);
218 SILC_LOG_DEBUG(("Outgoing packet assembled"));
221 /* Prepare outgoing data buffer for packet sending. This moves the data
222 area so that new packet may be added into it. If needed this allocates
223 more space to the buffer. This handles directly the connection's
224 outgoing buffer in SilcSocketConnection object. */
226 void silc_packet_send_prepare(SilcSocketConnection sock,
227 SilcUInt32 header_len,
233 totlen = header_len + padlen + data_len;
235 /* Prepare the outgoing buffer for packet sending. */
237 /* Allocate new buffer. This is done only once per connection. */
238 SILC_LOG_DEBUG(("Allocating outgoing data buffer"));
240 if (totlen > SILC_PACKET_DEFAULT_SIZE)
241 sock->outbuf = silc_buffer_alloc(totlen);
243 sock->outbuf = silc_buffer_alloc(SILC_PACKET_DEFAULT_SIZE);
244 silc_buffer_pull_tail(sock->outbuf, totlen);
245 silc_buffer_pull(sock->outbuf, header_len + padlen);
247 if (SILC_IS_OUTBUF_PENDING(sock)) {
248 /* There is some pending data in the buffer. */
250 /* Allocate more space if needed */
251 if ((sock->outbuf->end - sock->outbuf->tail) <
253 SILC_LOG_DEBUG(("Reallocating outgoing data buffer"));
254 sock->outbuf = silc_buffer_realloc(sock->outbuf,
255 sock->outbuf->truelen +
259 oldlen = sock->outbuf->len;
260 silc_buffer_pull_tail(sock->outbuf, totlen);
261 silc_buffer_pull(sock->outbuf, header_len + padlen + oldlen);
263 /* Buffer is free for use */
264 silc_buffer_clear(sock->outbuf);
266 /* Allocate more space if needed */
267 if ((sock->outbuf->end - sock->outbuf->tail) < (totlen + 20)) {
268 SILC_LOG_DEBUG(("Reallocating outgoing data buffer"));
269 sock->outbuf = silc_buffer_realloc(sock->outbuf,
270 sock->outbuf->truelen +
274 silc_buffer_pull_tail(sock->outbuf, totlen);
275 silc_buffer_pull(sock->outbuf, header_len + padlen);
280 /******************************************************************************
282 Packet Reception Routines
284 ******************************************************************************/
286 static int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
287 SilcUInt32 sequence, SilcBuffer buffer,
290 /* Receives packet from network and reads the data into connection's
291 incoming data buffer. If the data was read directly this returns the
292 read bytes, if error occured this returns -1, if the data could not
293 be read directly at this time this returns -2 in which case the data
294 should be read again at some later time, or If EOF occured this returns
297 int silc_packet_receive(SilcSocketConnection sock)
301 SILC_LOG_DEBUG(("Receiving packet from %s:%d [%s]", sock->hostname,
303 (sock->type == SILC_SOCKET_TYPE_UNKNOWN ? "Unknown" :
304 sock->type == SILC_SOCKET_TYPE_CLIENT ? "Client" :
305 sock->type == SILC_SOCKET_TYPE_SERVER ? "Server" :
308 /* Read some data from connection */
309 ret = silc_socket_read(sock);
314 /* Processes and decrypts the incmoing data, and calls parser callback
315 for each received packet that will handle the actual packet parsing.
316 If more than one packet was received this calls the parser multiple
317 times. The parser callback will get context SilcPacketParserContext
318 that includes the packet and the `parser_context' sent to this
321 The `local_is_router' indicates whether the caller is router server
322 in which case the receiving process of a certain packet types may
323 be special. Normal server and client must set it to FALSE. The
324 SilcPacketParserContext will indicate also whether the received
325 packet was normal or special packet. */
327 bool silc_packet_receive_process(SilcSocketConnection sock,
328 bool local_is_router,
329 SilcCipher cipher, SilcHmac hmac,
331 SilcPacketParserCallback parser,
332 void *parser_context)
334 SilcPacketParserContext *parse_ctx;
335 int packetlen, paddedlen, mac_len = 0;
338 /* Do not process for disconnected connection */
339 if (SILC_IS_DISCONNECTED(sock))
342 if (sock->inbuf->len < SILC_PACKET_MIN_HEADER_LEN)
346 mac_len = silc_hmac_len(hmac);
348 /* Parse the packets from the data */
349 while (sock->inbuf->len > 0 && cont) {
351 if (sock->inbuf->len < SILC_PACKET_MIN_HEADER_LEN) {
352 SILC_LOG_DEBUG(("Partial packet in queue, waiting for the rest"));
356 /* Decrypt first 16 bytes of the packet */
357 if (!SILC_IS_INBUF_PENDING(sock) && cipher)
358 silc_cipher_decrypt(cipher, sock->inbuf->data, sock->inbuf->data,
359 SILC_PACKET_MIN_HEADER_LEN, cipher->iv);
361 /* Get packet lenght and full packet length with padding */
362 SILC_PACKET_LENGTH(sock->inbuf, packetlen, paddedlen);
365 if (packetlen < SILC_PACKET_MIN_LEN) {
366 SILC_LOG_DEBUG(("Received invalid packet, dropped"));
367 silc_buffer_clear(sock->inbuf);
371 if (sock->inbuf->len < paddedlen + mac_len) {
372 SILC_LOG_DEBUG(("Received partial packet, waiting for the rest"
373 "(%d < %d)", sock->inbuf->len, paddedlen + mac_len));
374 SILC_SET_INBUF_PENDING(sock);
378 SILC_UNSET_INBUF_PENDING(sock);
379 parse_ctx = silc_calloc(1, sizeof(*parse_ctx));
380 parse_ctx->packet = silc_packet_context_alloc();
381 parse_ctx->packet->buffer = silc_buffer_alloc(paddedlen + mac_len);
382 parse_ctx->packet->type = sock->inbuf->data[3];
383 parse_ctx->packet->padlen = sock->inbuf->data[4];
384 parse_ctx->packet->sequence = sequence++;
385 parse_ctx->sock = sock;
386 parse_ctx->context = parser_context;
388 silc_buffer_pull_tail(parse_ctx->packet->buffer,
389 SILC_BUFFER_END(parse_ctx->packet->buffer));
390 silc_buffer_put(parse_ctx->packet->buffer, sock->inbuf->data,
391 paddedlen + mac_len);
393 SILC_LOG_HEXDUMP(("Incoming packet (%d) (%dB decrypted), len %d",
394 sequence - 1, SILC_PACKET_MIN_HEADER_LEN,
395 paddedlen + mac_len),
396 sock->inbuf->data, paddedlen + mac_len);
398 /* Check whether this is normal or special packet */
399 if (local_is_router) {
400 if (sock->inbuf->data[3] == SILC_PACKET_PRIVATE_MESSAGE &&
401 (sock->inbuf->data[2] & SILC_PACKET_FLAG_PRIVMSG_KEY))
402 parse_ctx->normal = FALSE;
403 else if (sock->inbuf->data[3] != SILC_PACKET_CHANNEL_MESSAGE ||
404 (sock->inbuf->data[3] == SILC_PACKET_CHANNEL_MESSAGE &&
405 sock->type == SILC_SOCKET_TYPE_ROUTER))
406 parse_ctx->normal = TRUE;
408 if (sock->inbuf->data[3] == SILC_PACKET_PRIVATE_MESSAGE &&
409 (sock->inbuf->data[2] & SILC_PACKET_FLAG_PRIVMSG_KEY))
410 parse_ctx->normal = FALSE;
411 else if (sock->inbuf->data[3] != SILC_PACKET_CHANNEL_MESSAGE)
412 parse_ctx->normal = TRUE;
415 /* Decrypt rest of the packet */
417 if (silc_packet_decrypt(cipher, hmac, parse_ctx->packet->sequence,
418 parse_ctx->packet->buffer,
419 parse_ctx->normal) == -1) {
420 SILC_LOG_WARNING(("Packet decryption failed %s:%d [%s]",
421 sock->hostname, sock->port,
422 (sock->type == SILC_SOCKET_TYPE_UNKNOWN ? "Unknown" :
423 sock->type == SILC_SOCKET_TYPE_CLIENT ? "Client" :
424 sock->type == SILC_SOCKET_TYPE_SERVER ? "Server" :
428 /* Pull the packet from inbuf thus we'll get the next one
430 silc_buffer_pull(sock->inbuf, paddedlen + mac_len);
432 /* Call the parser */
433 cont = (*parser)(parse_ctx, parser_context);
436 if (cont == FALSE && sock->inbuf->len > 0)
439 SILC_LOG_DEBUG(("Clearing inbound buffer"));
440 silc_buffer_clear(sock->inbuf);
444 /* Checks MAC in the packet. Returns TRUE if MAC is Ok. This is called
445 after packet has been totally decrypted and parsed. */
447 static int silc_packet_check_mac(SilcHmac hmac, SilcBuffer buffer,
452 unsigned char mac[32], psn[4];
455 SILC_LOG_DEBUG(("Verifying MAC"));
457 /* Compute HMAC of packet */
459 memset(mac, 0, sizeof(mac));
460 silc_hmac_init(hmac);
461 SILC_PUT32_MSB(sequence, psn);
462 silc_hmac_update(hmac, psn, 4);
463 silc_hmac_update(hmac, buffer->data, buffer->len);
464 silc_hmac_final(hmac, mac, &mac_len);
466 /* Compare the HMAC's (buffer->tail has the packet's HMAC) */
467 if (memcmp(buffer->tail, mac, mac_len)) {
468 SILC_LOG_ERROR(("MAC failed"));
472 SILC_LOG_DEBUG(("MAC is Ok"));
473 memset(mac, 0, sizeof(mac));
479 /* Decrypts rest of the packet (after decrypting just the SILC header).
480 After calling this function the packet is ready to be parsed by calling
481 silc_packet_parse. If everything goes without errors this returns TRUE,
482 if packet is malformed this returns FALSE. */
484 static int silc_packet_decrypt_rest(SilcCipher cipher, SilcHmac hmac,
489 /* Pull MAC from packet before decryption */
491 if ((buffer->len - silc_hmac_len(hmac)) > SILC_PACKET_MIN_LEN) {
492 silc_buffer_push_tail(buffer, silc_hmac_len(hmac));
494 SILC_LOG_DEBUG(("Bad MAC length in packet, packet dropped"));
499 SILC_LOG_DEBUG(("Decrypting rest of the packet"));
501 /* Decrypt rest of the packet */
502 silc_buffer_pull(buffer, SILC_PACKET_MIN_HEADER_LEN);
503 silc_cipher_decrypt(cipher, buffer->data, buffer->data, buffer->len,
505 silc_buffer_push(buffer, SILC_PACKET_MIN_HEADER_LEN);
507 SILC_LOG_HEXDUMP(("Fully decrypted packet, len %d", buffer->len),
508 buffer->data, buffer->len);
514 /* Decrypts rest of the SILC Packet header that has been decrypted partly
515 already. This decrypts the padding of the packet also. After calling
516 this function the packet is ready to be parsed by calling function
517 silc_packet_parse. This is used in special packet reception (protocol
518 defines the way of decrypting special packets). */
520 static int silc_packet_decrypt_rest_special(SilcCipher cipher,
524 /* Decrypt rest of the header plus padding */
528 /* Pull MAC from packet before decryption */
530 if ((buffer->len - silc_hmac_len(hmac)) > SILC_PACKET_MIN_LEN) {
531 silc_buffer_push_tail(buffer, silc_hmac_len(hmac));
533 SILC_LOG_DEBUG(("Bad MAC length in packet, packet dropped"));
538 SILC_LOG_DEBUG(("Decrypting rest of the header"));
540 /* padding length + src id len + dst id len + header length - 16
541 bytes already decrypted, gives the rest of the encrypted packet */
542 len = (((SilcUInt8)buffer->data[4] + (SilcUInt8)buffer->data[6] +
543 (SilcUInt8)buffer->data[7] + SILC_PACKET_HEADER_LEN) -
544 SILC_PACKET_MIN_HEADER_LEN);
546 silc_buffer_pull(buffer, SILC_PACKET_MIN_HEADER_LEN);
547 if (len > buffer->len) {
548 SILC_LOG_DEBUG(("Garbage in header of packet, bad packet length, "
552 silc_cipher_decrypt(cipher, buffer->data, buffer->data, len, cipher->iv);
553 silc_buffer_push(buffer, SILC_PACKET_MIN_HEADER_LEN);
554 SILC_LOG_HEXDUMP(("packet, len %d", buffer->len),
555 buffer->data, buffer->len);
561 /* Decrypts a packet. This assumes that typical SILC packet is the
562 packet to be decrypted and thus checks for normal and special SILC
563 packets and can handle both of them. This also computes and checks
564 the HMAC of the packet. If any other special or customized decryption
565 processing is required this function cannot be used. This returns
566 -1 on error, 0 when packet is normal packet and 1 when the packet
567 is special and requires special processing.
569 The `check_packet' is a callback funtion that this function will
570 call. The callback relates to the checking whether the packet is
571 normal packet or special packet and how it should be processed. If
572 the callback return TRUE the packet is normal and FALSE if the packet
573 is special and requires special procesing. */
575 static int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
576 SilcUInt32 sequence, SilcBuffer buffer,
579 /* If the packet type is not any special type lets decrypt rest
580 of the packet here. */
581 if (normal == TRUE) {
582 /* Normal packet, decrypt rest of the packet */
583 if (!silc_packet_decrypt_rest(cipher, hmac, buffer))
587 if (!silc_packet_check_mac(hmac, buffer, sequence))
592 /* Packet requires special handling, decrypt rest of the header.
593 This only decrypts. */
594 if (!silc_packet_decrypt_rest_special(cipher, hmac, buffer))
598 if (!silc_packet_check_mac(hmac, buffer, sequence))
605 /* Parses the packet. This is called when a whole packet is ready to be
606 parsed. The buffer sent must be already decrypted before calling this
607 function. The len argument must be the true length of the packet. This
608 function returns the type of the packet. The data section of the
609 buffer is parsed, not head or tail sections. */
611 SilcPacketType silc_packet_parse(SilcPacketContext *ctx, SilcCipher cipher)
613 SilcBuffer buffer = ctx->buffer;
617 SILC_LOG_DEBUG(("Parsing incoming packet"));
619 /* Check the length of the buffer */
620 if (buffer->len < SILC_PACKET_MIN_LEN) {
621 SILC_LOG_ERROR(("Bad packet length: %d, packet dropped", buffer->len));
622 return SILC_PACKET_NONE;
625 /* Parse the buffer. This parses the SILC header of the packet. */
626 len = silc_buffer_unformat(buffer,
627 SILC_STR_UI_SHORT(&ctx->truelen),
628 SILC_STR_UI_CHAR(&ctx->flags),
629 SILC_STR_UI_CHAR(&ctx->type),
630 SILC_STR_UI_CHAR(&ctx->padlen),
631 SILC_STR_UI_CHAR(&tmp),
632 SILC_STR_UI_CHAR(&ctx->src_id_len),
633 SILC_STR_UI_CHAR(&ctx->dst_id_len),
634 SILC_STR_UI_CHAR(&ctx->src_id_type),
636 if (len == -1 || tmp != 0)
637 return SILC_PACKET_NONE;
639 if (ctx->src_id_len > SILC_PACKET_MAX_ID_LEN ||
640 ctx->dst_id_len > SILC_PACKET_MAX_ID_LEN) {
641 SILC_LOG_ERROR(("Bad ID lengths in packet (%d and %d)",
642 ctx->src_id_len, ctx->dst_id_len));
643 return SILC_PACKET_NONE;
646 silc_buffer_pull(buffer, len);
647 ret = silc_buffer_unformat(buffer,
648 SILC_STR_UI_XNSTRING_ALLOC(&ctx->src_id,
650 SILC_STR_UI_CHAR(&ctx->dst_id_type),
651 SILC_STR_UI_XNSTRING_ALLOC(&ctx->dst_id,
653 SILC_STR_UI_XNSTRING(NULL, ctx->padlen),
656 return SILC_PACKET_NONE;
658 silc_buffer_push(buffer, len);
660 SILC_LOG_HEXDUMP(("parsed packet, len %d", ctx->buffer->len),
661 ctx->buffer->data, ctx->buffer->len);
663 /* Pull SILC header and padding from packet */
664 silc_buffer_pull(buffer, SILC_PACKET_HEADER_LEN +
665 ctx->src_id_len + ctx->dst_id_len + ctx->padlen);
667 SILC_LOG_DEBUG(("Incoming packet type: %d", ctx->type));
672 /* Perform special SILC Packet header parsing. This is required to some
673 packet types that have the data payload encrypted with different key
674 than the header area plus padding of the packet. Hence, this parses
675 the header in a way that it does not take the data area into account
676 and parses the header and padding area only. */
678 SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx,
681 SilcBuffer buffer = ctx->buffer;
685 SILC_LOG_DEBUG(("Parsing incoming packet"));
687 /* Check the length of the buffer */
688 if (buffer->len < SILC_PACKET_MIN_LEN) {
689 SILC_LOG_ERROR(("Bad packet length: %d, packet dropped", buffer->len));
690 return SILC_PACKET_NONE;
693 /* Parse the buffer. This parses the SILC header of the packet. */
694 len = silc_buffer_unformat(buffer,
695 SILC_STR_UI_SHORT(&ctx->truelen),
696 SILC_STR_UI_CHAR(&ctx->flags),
697 SILC_STR_UI_CHAR(&ctx->type),
698 SILC_STR_UI_CHAR(&ctx->padlen),
699 SILC_STR_UI_CHAR(&tmp),
700 SILC_STR_UI_CHAR(&ctx->src_id_len),
701 SILC_STR_UI_CHAR(&ctx->dst_id_len),
702 SILC_STR_UI_CHAR(&ctx->src_id_type),
704 if (len == -1 || tmp != 0) {
705 SILC_LOG_ERROR(("Malformed packet header, packet dropped"));
706 return SILC_PACKET_NONE;
709 if (ctx->src_id_len > SILC_PACKET_MAX_ID_LEN ||
710 ctx->dst_id_len > SILC_PACKET_MAX_ID_LEN) {
711 SILC_LOG_ERROR(("Bad ID lengths in packet (%d and %d)",
712 ctx->src_id_len, ctx->dst_id_len));
713 return SILC_PACKET_NONE;
716 silc_buffer_pull(buffer, len);
717 ret = silc_buffer_unformat(buffer,
718 SILC_STR_UI_XNSTRING_ALLOC(&ctx->src_id,
720 SILC_STR_UI_CHAR(&ctx->dst_id_type),
721 SILC_STR_UI_XNSTRING_ALLOC(&ctx->dst_id,
723 SILC_STR_UI_XNSTRING(NULL, ctx->padlen),
726 SILC_LOG_ERROR(("Malformed packet header, packet dropped"));
727 return SILC_PACKET_NONE;
730 silc_buffer_push(buffer, len);
732 SILC_LOG_HEXDUMP(("parsed packet, len %d", ctx->buffer->len),
733 ctx->buffer->data, ctx->buffer->len);
735 /* Pull SILC header and padding from packet */
736 silc_buffer_pull(buffer, SILC_PACKET_HEADER_LEN +
737 ctx->src_id_len + ctx->dst_id_len + ctx->padlen);
739 SILC_LOG_DEBUG(("Incoming packet type: %d", ctx->type));
744 /* Allocate packet context */
746 SilcPacketContext *silc_packet_context_alloc(void)
748 SilcPacketContext *ctx = silc_calloc(1, sizeof(*ctx));
753 /* Increse the reference count of the packet context. */
755 SilcPacketContext *silc_packet_context_dup(SilcPacketContext *ctx)
758 SILC_LOG_DEBUG(("Packet context %p refcnt %d->%d", ctx, ctx->users - 1,
763 /* Decrese the reference count of the packet context and free it only if
766 void silc_packet_context_free(SilcPacketContext *ctx)
769 SILC_LOG_DEBUG(("Packet context %p refcnt %d->%d", ctx, ctx->users + 1,
774 silc_buffer_free(ctx->buffer);
776 silc_free(ctx->src_id);
778 silc_free(ctx->dst_id);