5 Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
7 Copyright (C) 1997 - 2000 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; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
21 * Created: Fri Jul 25 18:52:14 1997
25 #include "silcincludes.h"
27 /******************************************************************************
29 Packet Sending Routines
31 ******************************************************************************/
33 /* Writes data from encrypted buffer to the socket connection. If the
34 data cannot be written at once, it will be written later with a timeout.
35 The data is written from the data section of the buffer, not from head
36 or tail section. This automatically pulls the data section towards end
37 after writing the data. */
39 int silc_packet_write(int sock, SilcBuffer src)
43 SILC_LOG_DEBUG(("Writing data to socket %d", sock));
46 ret = write(sock, src->data, src->len);
48 if (errno == EAGAIN) {
49 SILC_LOG_DEBUG(("Could not write immediately, will do it later"));
52 SILC_LOG_ERROR(("Cannot write to socket: %s", strerror(errno)));
56 silc_buffer_pull(src, ret);
59 SILC_LOG_DEBUG(("Wrote data %d bytes", ret));
64 /* Actually sends the packet. This flushes the connections outgoing data
65 buffer. If data is sent directly to the network this returns the bytes
66 written, if error occured this returns -1 and if the data could not
67 be written directly to the network at this time this returns -2, in
68 which case the data should be queued by the caller and sent at some
69 later time. If `force_send' is TRUE this attempts to write the data
70 directly to the network, if FALSE, this returns -2. */
72 int silc_packet_send(SilcSocketConnection sock, int force_send)
74 /* Send now if forced to do so */
75 if (force_send == TRUE) {
78 SILC_LOG_DEBUG(("Forcing packet send, packet sent immediately"));
80 /* Write to network */
81 ret = silc_packet_write(sock->sock, sock->outbuf);
84 SILC_LOG_ERROR(("Error sending packet, dropped"));
89 SILC_LOG_DEBUG(("Could not force the send, packet put to queue"));
92 SILC_LOG_DEBUG(("Packet in queue"));
97 /* Encrypts a packet. This also creates HMAC of the packet before
98 encryption and adds the HMAC at the end of the buffer. This assumes
99 that there is enough free space at the end of the buffer to add the
100 computed HMAC. This is the normal way of encrypting packets, if some
101 other process of HMAC computing and encryption is needed this function
104 void silc_packet_encrypt(SilcCipher cipher, SilcHmac hmac,
105 SilcBuffer buffer, unsigned int len)
107 unsigned char mac[32];
110 SILC_LOG_DEBUG(("Encrypting packet, cipher %s, len %d (%d)",
111 cipher->cipher->name, len, len - 2));
114 /* Compute HMAC. This assumes that HMAC is created from the entire
115 data area thus this uses the length found in buffer, not the length
118 silc_hmac_make(hmac, buffer->data, buffer->len, mac);
119 silc_buffer_put_tail(buffer, mac, hmac->hash->hash->hash_len);
120 memset(mac, 0, sizeof(mac));
123 /* Encrypt the data area of the packet. 2 bytes of the packet
124 are not encrypted. */
126 cipher->cipher->encrypt(cipher->context, buffer->data + 2,
127 buffer->data + 2, len - 2, cipher->iv);
129 /* Pull the HMAC into the visible data area in the buffer */
131 silc_buffer_pull_tail(buffer, hmac->hash->hash->hash_len);
134 /* Assembles a new packet to be ready for send out. The buffer sent as
135 argument must include the data to be sent and it must not be encrypted.
136 The packet also must have enough free space so that the SILC header
137 and padding maybe added to the packet. The packet is encrypted after
138 this function has returned.
140 The buffer sent as argument should be something like following:
142 --------------------------------------------
143 | head | data | tail |
144 --------------------------------------------
148 So that the SILC header and 1 - 16 bytes of padding can fit to
149 the buffer. After assembly the buffer might look like this:
151 --------------------------------------------
153 --------------------------------------------
155 Start of assembled packet
157 Packet construct is as follows (* = won't be encrypted):
160 2 bytes Payload length (*)
163 1 byte Source ID Type
164 2 bytes Source ID Length
166 1 byte Destination ID Type
167 2 bytes Destination ID Length
168 x bytes Destination ID
174 All fields in the packet will be authenticated by MAC. The MAC is
175 not computed here, it must be computed differently before encrypting
180 void silc_packet_assemble(SilcPacketContext *ctx)
182 unsigned char tmppad[SILC_PACKET_MAX_PADLEN];
185 SILC_LOG_DEBUG(("Assembling outgoing packet"));
187 /* Get the true length of the packet. This is saved as payload length
188 into the packet header. This does not include the length of the
191 ctx->truelen = ctx->buffer->len + SILC_PACKET_HEADER_LEN +
192 ctx->src_id_len + ctx->dst_id_len;
194 /* Calculate the length of the padding. The padding is calculated from
195 the data that will be encrypted. As protocol states 3 first bytes
196 of the packet are not encrypted they are not included in the
197 padding calculation. */
199 ctx->padlen = SILC_PACKET_PADLEN(ctx->truelen);
201 /* Put the start of the data section to the right place. */
202 silc_buffer_push(ctx->buffer, SILC_PACKET_HEADER_LEN +
203 ctx->src_id_len + ctx->dst_id_len + ctx->padlen);
205 /* Get random padding */
207 for (i = 0; i < ctx->padlen; i++) tmppad[i] = silc_rng_get_byte(ctx->rng);
209 /* XXX: For testing - to be removed */
210 memset(tmppad, 65, sizeof(tmppad));
213 /* Create the packet. This creates the SILC header and adds padding,
214 rest of the buffer remains as it is. */
215 silc_buffer_format(ctx->buffer,
216 SILC_STR_UI_SHORT(ctx->truelen),
217 SILC_STR_UI_CHAR(ctx->flags),
218 SILC_STR_UI_CHAR(ctx->type),
219 SILC_STR_UI_SHORT(ctx->src_id_len),
220 SILC_STR_UI_SHORT(ctx->dst_id_len),
221 SILC_STR_UI_CHAR(ctx->src_id_type),
222 SILC_STR_UI_XNSTRING(ctx->src_id, ctx->src_id_len),
223 SILC_STR_UI_CHAR(ctx->dst_id_type),
224 SILC_STR_UI_XNSTRING(ctx->dst_id, ctx->dst_id_len),
225 SILC_STR_UI_XNSTRING(tmppad, ctx->padlen),
228 SILC_LOG_HEXDUMP(("Assembled packet, len %d", ctx->buffer->len),
229 ctx->buffer->data, ctx->buffer->len);
231 SILC_LOG_DEBUG(("Outgoing packet assembled"));
234 /* Prepare outgoing data buffer for packet sending. This moves the data
235 area so that new packet may be added into it. If needed this allocates
236 more space to the buffer. This handles directly the connection's
237 outgoing buffer in SilcSocketConnection object. */
239 void silc_packet_send_prepare(SilcSocketConnection sock,
240 unsigned int header_len,
242 unsigned int data_len)
246 totlen = header_len + padlen + data_len;
248 /* Prepare the outgoing buffer for packet sending. */
250 /* Allocate new buffer. This is done only once per connection. */
251 SILC_LOG_DEBUG(("Allocating outgoing data buffer"));
253 sock->outbuf = silc_buffer_alloc(SILC_PACKET_DEFAULT_SIZE);
254 silc_buffer_pull_tail(sock->outbuf, totlen);
255 silc_buffer_pull(sock->outbuf, header_len + padlen);
257 if (SILC_IS_OUTBUF_PENDING(sock)) {
258 /* There is some pending data in the buffer. */
260 /* Allocate more space if needed */
261 if ((sock->outbuf->end - sock->outbuf->tail) < data_len) {
262 SILC_LOG_DEBUG(("Reallocating outgoing data buffer"));
263 sock->outbuf = silc_buffer_realloc(sock->outbuf,
264 sock->outbuf->truelen + totlen);
267 oldlen = sock->outbuf->len;
268 silc_buffer_pull_tail(sock->outbuf, totlen);
269 silc_buffer_pull(sock->outbuf, header_len + padlen + oldlen);
271 /* Buffer is free for use */
272 silc_buffer_clear(sock->outbuf);
273 silc_buffer_pull_tail(sock->outbuf, totlen);
274 silc_buffer_pull(sock->outbuf, header_len + padlen);
279 /******************************************************************************
281 Packet Reception Routines
283 ******************************************************************************/
285 /* Reads data from the socket connection into the incoming data buffer.
286 However, this does not parse the packet, it only reads some amount from
287 the network. If there are more data available that can be read at a time
288 the rest of the data will be read later with a timeout and only after
289 that the packet is ready to be parsed.
291 The destination buffer sent as argument must be initialized before
292 calling this function, and, the data section and the start of the tail
293 section must be same. Ie. we add the read data to the tail section of
294 the buffer hence the data section is the start of the buffer.
296 This returns amount of bytes read or -1 on error or -2 on case where
297 all of the data could not be read at once. */
299 int silc_packet_read(int sock, SilcBuffer dest)
302 unsigned char buf[SILC_PACKET_READ_SIZE];
304 SILC_LOG_DEBUG(("Reading data from socket %d", sock));
306 /* Read the data from the socket. */
307 len = read(sock, buf, sizeof(buf));
309 if (errno == EAGAIN || errno == EINTR) {
310 SILC_LOG_DEBUG(("Could not read immediately, will do it later"));
313 SILC_LOG_ERROR(("Cannot read from socket: %d", strerror(errno)));
320 /* Insert the data to the buffer. If the data doesn't fit to the
321 buffer space is allocated for the buffer. */
322 /* XXX: This may actually be bad thing as if there is pending data in
323 the buffer they will be lost! */
326 /* If the data doesn't fit we just have to allocate a whole new
328 if (dest->truelen <= len) {
330 /* Free the old buffer */
331 memset(dest->head, 'F', dest->truelen);
332 silc_free(dest->head);
334 /* Allocate new data area */
335 len += SILC_PACKET_DEFAULT_SIZE;
336 dest->data = silc_calloc(len, sizeof(char));
339 dest->head = dest->data;
340 dest->data = dest->data;
341 dest->tail = dest->data;
342 dest->end = dest->data + dest->truelen;
343 len -= SILC_PACKET_DEFAULT_SIZE;
346 silc_buffer_put_tail(dest, buf, len);
347 silc_buffer_pull_tail(dest, len);
350 SILC_LOG_DEBUG(("Read %d bytes", len));
355 /* Processes the received data. This checks the received data and
356 calls parser callback that handles the actual packet decryption
357 and parsing. If more than one packet was received this calls the
358 parser multiple times. The parser callback will get context
359 SilcPacketParserContext that includes the packet and the `context'
360 sent to this function. */
362 void silc_packet_receive_process(SilcSocketConnection sock,
363 SilcCipher cipher, SilcHmac hmac,
364 SilcPacketParserCallback parser,
367 SilcPacketParserContext *parse_ctx;
368 int packetlen, paddedlen, count, mac_len = 0;
370 /* We need at least 2 bytes of data to be able to start processing
372 if (sock->inbuf->len < 2)
376 mac_len = hmac->hash->hash->hash_len;
378 /* Parse the packets from the data */
380 while (sock->inbuf->len > 0) {
381 SILC_PACKET_LENGTH(sock->inbuf, packetlen, paddedlen);
385 if (packetlen < SILC_PACKET_MIN_LEN) {
386 SILC_LOG_DEBUG(("Received invalid packet, dropped"));
390 if (sock->inbuf->len < paddedlen + mac_len) {
391 SILC_LOG_DEBUG(("Received partial packet, waiting for the rest"));
395 parse_ctx = silc_calloc(1, sizeof(*parse_ctx));
396 parse_ctx->packet = silc_packet_context_alloc();
397 parse_ctx->packet->buffer = silc_buffer_alloc(paddedlen + mac_len);
398 parse_ctx->sock = sock;
399 parse_ctx->cipher = cipher;
400 parse_ctx->hmac = hmac;
401 parse_ctx->context = context;
403 silc_buffer_pull_tail(parse_ctx->packet->buffer,
404 SILC_BUFFER_END(parse_ctx->packet->buffer));
405 silc_buffer_put(parse_ctx->packet->buffer, sock->inbuf->data,
406 paddedlen + mac_len);
408 SILC_LOG_HEXDUMP(("Incoming packet, len %d",
409 parse_ctx->packet->buffer->len),
410 parse_ctx->packet->buffer->data,
411 parse_ctx->packet->buffer->len);
413 /* Call the parser */
415 (*parser)(parse_ctx);
417 /* Pull the packet from inbuf thus we'll get the next one
419 silc_buffer_pull(sock->inbuf, paddedlen);
421 silc_buffer_pull(sock->inbuf, mac_len);
424 silc_buffer_clear(sock->inbuf);
427 /* Receives packet from network and reads the data into connection's
428 incoming data buffer. If the data was read directly this returns the
429 read bytes, if error occured this returns -1, if the data could not
430 be read directly at this time this returns -2 in which case the data
431 should be read again at some later time, or If EOF occured this returns
434 int silc_packet_receive(SilcSocketConnection sock)
438 /* Allocate the incoming data buffer if not done already. */
440 sock->inbuf = silc_buffer_alloc(SILC_PACKET_DEFAULT_SIZE);
442 /* Read some data from connection */
443 ret = silc_packet_read(sock->sock, sock->inbuf);
447 SILC_LOG_ERROR(("Error reading packet, dropped"));
453 /* Checks MAC in the packet. Returns TRUE if MAC is Ok. This is called
454 after packet has been totally decrypted and parsed. */
456 static int silc_packet_check_mac(SilcHmac hmac, SilcBuffer buffer)
460 unsigned char mac[32];
462 SILC_LOG_DEBUG(("Verifying MAC"));
464 /* Compute HMAC of packet */
465 memset(mac, 0, sizeof(mac));
466 silc_hmac_make(hmac, buffer->data, buffer->len, mac);
468 /* Compare the HMAC's (buffer->tail has the packet's HMAC) */
469 if (memcmp(mac, buffer->tail, hmac->hash->hash->hash_len)) {
470 SILC_LOG_DEBUG(("MAC failed"));
474 SILC_LOG_DEBUG(("MAC is Ok"));
475 memset(mac, 0, sizeof(mac));
481 /* Decrypts rest of the packet (after decrypting just the SILC header).
482 After calling this function the packet is ready to be parsed by calling
483 silc_packet_parse. If everything goes without errors this returns TRUE,
484 if packet is malformed this returns FALSE. */
486 static int silc_packet_decrypt_rest(SilcCipher cipher, SilcHmac hmac,
491 /* Pull MAC from packet before decryption */
493 if ((buffer->len - hmac->hash->hash->hash_len) > SILC_PACKET_MIN_LEN) {
494 silc_buffer_push_tail(buffer, hmac->hash->hash->hash_len);
496 SILC_LOG_DEBUG(("Bad MAC length in packet, packet dropped"));
501 SILC_LOG_DEBUG(("Decrypting rest of the packet"));
503 /* Decrypt rest of the packet */
504 silc_buffer_pull(buffer, SILC_PACKET_MIN_HEADER_LEN - 2);
505 cipher->cipher->decrypt(cipher->context, buffer->data + 2,
506 buffer->data + 2, buffer->len - 2,
508 silc_buffer_push(buffer, SILC_PACKET_MIN_HEADER_LEN - 2);
510 SILC_LOG_HEXDUMP(("Fully decrypted packet, len %d", buffer->len),
511 buffer->data, buffer->len);
517 /* Decrypts rest of the SILC Packet header that has been decrypted partly
518 already. This decrypts the padding of the packet also. After calling
519 this function the packet is ready to be parsed by calling function
520 silc_packet_parse. This is used in special packet reception (protocol
521 defines the way of decrypting special packets). */
523 static int silc_packet_decrypt_rest_special(SilcCipher cipher,
527 /* Decrypt rest of the header plus padding */
529 unsigned short truelen, len1, len2, padlen;
531 /* Pull MAC from packet before decryption */
533 if ((buffer->len - hmac->hash->hash->hash_len) > SILC_PACKET_MIN_LEN) {
534 silc_buffer_push_tail(buffer, hmac->hash->hash->hash_len);
536 SILC_LOG_DEBUG(("Bad MAC length in packet, packet dropped"));
541 SILC_LOG_DEBUG(("Decrypting rest of the header"));
543 SILC_GET16_MSB(len1, &buffer->data[4]);
544 SILC_GET16_MSB(len2, &buffer->data[6]);
546 truelen = SILC_PACKET_HEADER_LEN + len1 + len2;
547 padlen = SILC_PACKET_PADLEN(truelen);
548 len1 = (truelen + padlen) - (SILC_PACKET_MIN_HEADER_LEN - 2);
550 silc_buffer_pull(buffer, SILC_PACKET_MIN_HEADER_LEN - 2);
551 cipher->cipher->decrypt(cipher->context, buffer->data + 2,
552 buffer->data + 2, len1 - 2,
554 silc_buffer_push(buffer, SILC_PACKET_MIN_HEADER_LEN - 2);
560 /* Decrypts a packet. This assumes that typical SILC packet is the
561 packet to be decrypted and thus checks for normal and special SILC
562 packets and can handle both of them. This also computes and checks
563 the HMAC of the packet. If any other special or customized decryption
564 processing is required this function cannot be used. This returns
565 -1 on error, 0 when packet is normal packet and 1 when the packet
566 is special and requires special processing. */
568 int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
569 SilcBuffer buffer, SilcPacketContext *packet)
572 /* Decrypt start of the packet header */
574 cipher->cipher->decrypt(cipher->context, buffer->data + 2,
575 buffer->data + 2, SILC_PACKET_MIN_HEADER_LEN - 2,
578 /* If the packet type is not any special type lets decrypt rest
579 of the packet here. */
580 if ((buffer->data[3] == SILC_PACKET_PRIVATE_MESSAGE &&
581 !(buffer->data[2] & SILC_PACKET_FLAG_PRIVMSG_KEY)) ||
582 buffer->data[3] != SILC_PACKET_CHANNEL_MESSAGE) {
584 /* Normal packet, decrypt rest of the packet */
585 if (!silc_packet_decrypt_rest(cipher, hmac, buffer))
589 if (!silc_packet_check_mac(hmac, buffer))
594 /* Packet requires special handling, decrypt rest of the header.
595 This only decrypts. */
596 if (!silc_packet_decrypt_rest_special(cipher, hmac, buffer))
600 if (!silc_packet_check_mac(hmac, buffer))
607 /* Parses the packet. This is called when a whole packet is ready to be
608 parsed. The buffer sent must be already decrypted before calling this
609 function. The len argument must be the true length of the packet. This
610 function returns the type of the packet. The data section of the
611 buffer is parsed, not head or tail sections. */
613 SilcPacketType silc_packet_parse(SilcPacketContext *ctx)
615 SilcBuffer buffer = ctx->buffer;
618 SILC_LOG_DEBUG(("Parsing incoming packet"));
620 /* Check the length of the buffer */
621 if (buffer->len < SILC_PACKET_MIN_LEN) {
622 SILC_LOG_ERROR(("Bad packet length: %d, packet dropped", buffer->len));
623 return SILC_PACKET_NONE;
626 /* Parse the buffer. This parses the SILC header of the packet. */
627 len = silc_buffer_unformat(buffer,
628 SILC_STR_UI_SHORT(&ctx->truelen),
629 SILC_STR_UI_CHAR(&ctx->flags),
630 SILC_STR_UI_CHAR(&ctx->type),
631 SILC_STR_UI_SHORT(&ctx->src_id_len),
632 SILC_STR_UI_SHORT(&ctx->dst_id_len),
633 SILC_STR_UI_CHAR(&ctx->src_id_type),
636 return SILC_PACKET_NONE;
638 if (ctx->src_id_len > SILC_PACKET_MAX_ID_LEN ||
639 ctx->dst_id_len > SILC_PACKET_MAX_ID_LEN) {
640 SILC_LOG_ERROR(("Bad ID lengths in packet"));
641 return SILC_PACKET_NONE;
644 /* Calculate length of padding in packet */
645 ctx->padlen = SILC_PACKET_PADLEN(ctx->truelen);
647 silc_buffer_pull(buffer, len);
648 ret = silc_buffer_unformat(buffer,
649 SILC_STR_UI_XNSTRING_ALLOC(&ctx->src_id,
651 SILC_STR_UI_CHAR(&ctx->dst_id_type),
652 SILC_STR_UI_XNSTRING_ALLOC(&ctx->dst_id,
654 SILC_STR_UI_XNSTRING(NULL, ctx->padlen),
657 return SILC_PACKET_NONE;
659 silc_buffer_push(buffer, len);
661 SILC_LOG_HEXDUMP(("parsed packet, len %d", ctx->buffer->len),
662 ctx->buffer->data, ctx->buffer->len);
664 /* Pull SILC header and padding from packet */
665 silc_buffer_pull(buffer, SILC_PACKET_HEADER_LEN +
666 ctx->src_id_len + ctx->dst_id_len + ctx->padlen);
668 SILC_LOG_DEBUG(("Incoming packet type: %d", ctx->type));
673 /* Perform special SILC Packet header parsing. This is required to some
674 packet types that have the data payload encrypted with different key
675 than the header area plus padding of the packet. Hence, this parses
676 the header in a way that it does not take the data area into account
677 and parses the header and padding area only. */
679 SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx)
681 SilcBuffer buffer = ctx->buffer;
682 int len, tmplen, ret;
684 SILC_LOG_DEBUG(("Parsing incoming packet"));
686 /* Check the length of the buffer */
687 if (buffer->len < SILC_PACKET_MIN_LEN) {
688 SILC_LOG_ERROR(("Bad packet length: %d, packet dropped", buffer->len));
689 return SILC_PACKET_NONE;
692 /* Parse the buffer. This parses the SILC header of the packet. */
693 len = silc_buffer_unformat(buffer,
694 SILC_STR_UI_SHORT(&ctx->truelen),
695 SILC_STR_UI_CHAR(&ctx->flags),
696 SILC_STR_UI_CHAR(&ctx->type),
697 SILC_STR_UI_SHORT(&ctx->src_id_len),
698 SILC_STR_UI_SHORT(&ctx->dst_id_len),
699 SILC_STR_UI_CHAR(&ctx->src_id_type),
702 return SILC_PACKET_NONE;
704 if (ctx->src_id_len > SILC_PACKET_MAX_ID_LEN ||
705 ctx->dst_id_len > SILC_PACKET_MAX_ID_LEN) {
706 SILC_LOG_ERROR(("Bad ID lengths in packet"));
707 return SILC_PACKET_NONE;
710 /* Calculate length of padding in packet. As this is special packet
711 the data area is not used in the padding calculation as it won't
712 be decrypted by the caller. */
713 tmplen = SILC_PACKET_HEADER_LEN + ctx->src_id_len + ctx->dst_id_len;
714 ctx->padlen = SILC_PACKET_PADLEN(tmplen);
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 return SILC_PACKET_NONE;
728 silc_buffer_push(buffer, len);
730 SILC_LOG_HEXDUMP(("parsed packet, len %d", ctx->buffer->len),
731 ctx->buffer->data, ctx->buffer->len);
733 /* Pull SILC header and padding from packet */
734 silc_buffer_pull(buffer, SILC_PACKET_HEADER_LEN +
735 ctx->src_id_len + ctx->dst_id_len + ctx->padlen);
737 SILC_LOG_DEBUG(("Incoming packet type: %d", ctx->type));
742 /* Allocate packet context */
744 SilcPacketContext *silc_packet_context_alloc()
746 SilcPacketContext *ctx = silc_calloc(1, sizeof(*ctx));
751 /* Increse the reference count of the packet context. */
753 SilcPacketContext *silc_packet_context_dup(SilcPacketContext *ctx)
756 SILC_LOG_DEBUG(("Packet context %p rfcnt %d->%d", ctx, ctx->users - 1,
761 /* Decrese the reference count of the packet context and free it only if
764 void silc_packet_context_free(SilcPacketContext *ctx)
767 SILC_LOG_DEBUG(("Packet context %p rfcnt %d->%d", ctx, ctx->users + 1,
772 silc_buffer_free(ctx->buffer);
774 silc_free(ctx->src_id);
776 silc_free(ctx->dst_id);