silcpacket.c
- Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+ Author: Pekka Riikonen <priikone@silcnet.org>
- Copyright (C) 1997 - 2000 Pekka Riikonen
+ Copyright (C) 1997 - 2005 Pekka Riikonen
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
+ the Free Software Foundation; version 2 of the License.
+
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
/*
* Created: Fri Jul 25 18:52:14 1997
*/
-/*
- * $Id$
- * $Log$
- * Revision 1.2 2000/07/05 06:06:35 priikone
- * Global cosmetic change.
- *
- * Revision 1.1.1.1 2000/06/27 11:36:55 priikone
- * Imported from internal CVS/Added Log headers.
- *
- *
- */
+/* $Id$ */
+
+#include "silc.h"
+
+/************************** Types and definitions ***************************/
+
+/* Packet engine */
+struct SilcPacketEngineStruct {
+ SilcRng rng; /* RNG for engine */
+ SilcPacketCallbacks *callbacks; /* Packet callbacks */
+ void *callback_context; /* Context for callbacks */
+ SilcList streams; /* All streams in engine */
+ SilcList packet_pool; /* Free list for received packets */
+ SilcMutex lock; /* Engine lock */
+ SilcBool local_is_router;
+};
+
+/* Packet procesor context */
+typedef struct SilcPacketProcessStruct {
+ SilcInt32 priority; /* Priority */
+ SilcPacketType *types; /* Packets to process */
+ SilcPacketCallbacks *callbacks; /* Callbacks or NULL */
+ void *callback_context;
+} *SilcPacketProcess;
+
+/* Packet stream */
+struct SilcPacketStreamStruct {
+ struct SilcPacketStreamStruct *next;
+ SilcPacketEngine engine; /* Packet engine */
+ SilcStream stream; /* Underlaying stream */
+ SilcMutex lock; /* Stream lock */
+ SilcDList process; /* Packet processors, it set */
+ SilcHashTable streamers; /* Valid if streamers exist */
+ void *stream_context; /* Stream context */
+ SilcBufferStruct inbuf; /* In buffer */
+ SilcBufferStruct outbuf; /* Out buffer */
+ SilcUInt32 send_psn; /* Sending sequence */
+ SilcCipher send_key; /* Sending key */
+ SilcHmac send_hmac; /* Sending HMAC */
+ SilcUInt32 receive_psn; /* Receiving sequence */
+ SilcCipher receive_key; /* Receiving key */
+ SilcHmac receive_hmac; /* Receiving HMAC */
+ unsigned char *src_id; /* Source ID */
+ unsigned char *dst_id; /* Destination ID */
+ unsigned int src_id_len : 6;
+ unsigned int src_id_type : 2;
+ unsigned int dst_id_len : 6;
+ unsigned int dst_id_type : 2;
+ SilcUInt8 refcnt; /* Reference counter */
+ unsigned int is_router : 1; /* Set if router stream */
+ unsigned int destroyed : 1; /* Set if destroyed */
+};
+
+/* Initial size of stream buffers */
+#define SILC_PACKET_DEFAULT_SIZE 1024
+
+/* Header length without source and destination ID's. */
+#define SILC_PACKET_HEADER_LEN 10
+
+/* Minimum length of SILC Packet Header. This much is decrypted always
+ when packet is received to be able to get all the relevant data out
+ from the header. */
+#define SILC_PACKET_MIN_HEADER_LEN 16
+
+/* Maximum padding length */
+#define SILC_PACKET_MAX_PADLEN 128
+
+/* Default padding length */
+#define SILC_PACKET_DEFAULT_PADLEN 16
+
+/* Minimum packet length */
+#define SILC_PACKET_MIN_LEN (SILC_PACKET_HEADER_LEN + 1)
+
+
+/* Macros */
+
+/* Returns true length of the packet. */
+#define SILC_PACKET_LENGTH(__packetdata, __ret_truelen, __ret_paddedlen) \
+do { \
+ SILC_GET16_MSB((__ret_truelen), (__packetdata)); \
+ (__ret_paddedlen) = (__ret_truelen) + (SilcUInt8)(__packetdata)[4]; \
+} while(0)
+
+/* Calculates the data length with given header length. This macro
+ can be used to check whether the data_len with header_len exceeds
+ SILC_PACKET_MAX_LEN. If it does, this returns the new data_len
+ so that the SILC_PACKET_MAX_LEN is not exceeded. If the data_len
+ plus header_len fits SILC_PACKET_MAX_LEN the returned data length
+ is the data_len given as argument. */
+#define SILC_PACKET_DATALEN(data_len, header_len) \
+ ((data_len + header_len) > SILC_PACKET_MAX_LEN ? \
+ data_len - ((data_len + header_len) - SILC_PACKET_MAX_LEN) : data_len)
+
+/* Calculates the length of the padding in the packet. */
+#define SILC_PACKET_PADLEN(__packetlen, __blocklen, __padlen) \
+do { \
+ __padlen = (SILC_PACKET_DEFAULT_PADLEN - (__packetlen) % \
+ ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN)); \
+ if (__padlen < 8) \
+ __padlen += ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN); \
+} while(0)
+
+/* Returns the length of the padding up to the maximum length, which
+ is 128 bytes.*/
+#define SILC_PACKET_PADLEN_MAX(__packetlen, __blocklen, __padlen) \
+do { \
+ __padlen = (SILC_PACKET_MAX_PADLEN - (__packetlen) % \
+ ((__blocklen) ? (__blocklen) : SILC_PACKET_DEFAULT_PADLEN)); \
+} while(0)
+
+/* EOS callback */
+#define SILC_PACKET_CALLBACK_EOS(s) \
+do { \
+ (s)->engine->callbacks->eos((s)->engine, s, \
+ (s)->engine->callback_context, \
+ (s)->stream_context); \
+} while(0)
+
+/* Error callback */
+#define SILC_PACKET_CALLBACK_ERROR(s, err) \
+do { \
+ (s)->engine->callbacks->error((s)->engine, s, err, \
+ (s)->engine->callback_context, \
+ (s)->stream_context); \
+} while(0)
+
+
+/************************ Static utility functions **************************/
+
+static void silc_packet_read_process(SilcPacketStream stream);
+
+/* Our stream IO notifier callback. */
+
+static void silc_packet_stream_io(SilcStream stream, SilcStreamStatus status,
+ void *context)
+{
+ SilcPacketStream ps = context;
+ int ret;
-#include "silcincludes.h"
+ silc_mutex_lock(ps->lock);
-/* Writes data from encrypted buffer to the socket connection. If the
- data cannot be written at once, it will be written later with a timeout.
- The data is written from the data section of the buffer, not from head
- or tail section. This automatically pulls the data section towards end
- after writing the data. */
+ if (ps->destroyed) {
+ silc_mutex_unlock(ps->lock);
+ return;
+ }
-int silc_packet_write(int sock, SilcBuffer src)
-{
- int ret = 0;
+ switch (status) {
+
+ case SILC_STREAM_CAN_WRITE:
+ if (!silc_buffer_headlen(&ps->outbuf)) {
+ silc_mutex_unlock(ps->lock);
+ return;
+ }
- SILC_LOG_DEBUG(("Writing data to socket %d", sock));
+ SILC_LOG_DEBUG(("Writing pending data to stream"));
+
+ /* Write pending data to stream */
+ while (silc_buffer_len(&ps->outbuf) > 0) {
+ ret = silc_stream_write(ps->stream, ps->outbuf.data,
+ silc_buffer_len(&ps->outbuf));
+ if (ret == 0) {
+ /* EOS */
+ silc_buffer_reset(&ps->outbuf);
+ silc_mutex_unlock(ps->lock);
+ SILC_PACKET_CALLBACK_EOS(ps);
+ return;
+ }
- if (src->len > 0) {
- ret = write(sock, src->data, src->len);
- if (ret < 0) {
- if (errno == EAGAIN) {
- SILC_LOG_DEBUG(("Could not write immediately, will do it later"));
- return -2;
+ if (ret == -2) {
+ /* Error */
+ silc_buffer_reset(&ps->outbuf);
+ silc_mutex_unlock(ps->lock);
+ SILC_PACKET_CALLBACK_ERROR(ps, SILC_PACKET_ERR_WRITE);
+ return;
}
- SILC_LOG_ERROR(("Cannot write to socket: %s", strerror(errno)));
- return -1;
+
+ if (ret == -1) {
+ /* Cannot write now, write later. */
+ silc_mutex_unlock(ps->lock);
+ return;
+ }
+
+ /* Wrote data */
+ silc_buffer_pull(&ps->outbuf, ret);
+ }
+
+ silc_buffer_reset(&ps->outbuf);
+
+ silc_mutex_unlock(ps->lock);
+ break;
+
+ case SILC_STREAM_CAN_READ:
+ /* Packet receiving can only happen in one thread, so locking is not
+ required in packet receiving procedure. */
+ silc_mutex_unlock(ps->lock);
+
+ SILC_LOG_DEBUG(("Reading data from stream"));
+
+ /* Make sure we have fair amount of free space in inbuf */
+ if (silc_buffer_taillen(&ps->inbuf) < SILC_PACKET_DEFAULT_SIZE)
+ if (!silc_buffer_realloc(&ps->inbuf, silc_buffer_truelen(&ps->inbuf) +
+ SILC_PACKET_DEFAULT_SIZE * 2))
+ return;
+
+ /* Read data from stream */
+ ret = silc_stream_read(ps->stream, ps->inbuf.tail,
+ silc_buffer_taillen(&ps->inbuf));
+
+ if (ret == 0) {
+ /* EOS */
+ silc_buffer_reset(&ps->inbuf);
+ SILC_PACKET_CALLBACK_EOS(ps);
+ return;
+ }
+
+ if (ret == -2) {
+ /* Error */
+ silc_buffer_reset(&ps->inbuf);
+ SILC_PACKET_CALLBACK_ERROR(ps, SILC_PACKET_ERR_READ);
+ return;
+ }
+
+ if (ret == -1) {
+ /* Cannot read now, do it later. */
+ silc_buffer_pull(&ps->inbuf, silc_buffer_len(&ps->inbuf));
+ return;
+ }
+
+ /* Read some data */
+ silc_buffer_pull_tail(&ps->inbuf, ret);
+
+ /* Now process the data */
+ silc_packet_read_process(ps);
+
+ break;
+
+ default:
+ silc_mutex_unlock(ps->lock);
+ break;
+ }
+}
+
+/* Allocate packet */
+
+static SilcPacket silc_packet_alloc(SilcPacketEngine engine)
+{
+ SilcPacket packet;
+
+ SILC_LOG_DEBUG(("Packet pool count %d",
+ silc_list_count(engine->packet_pool)));
+
+ silc_mutex_lock(engine->lock);
+
+ /* Get packet from freelist or allocate new one. */
+ packet = silc_list_get(engine->packet_pool);
+ if (!packet) {
+ void *tmp;
+
+ silc_mutex_unlock(engine->lock);
+
+ packet = silc_calloc(1, sizeof(*packet));
+ if (!packet)
+ return NULL;
+
+ SILC_LOG_DEBUG(("Allocating new packet %p", packet));
+
+ tmp = silc_malloc(SILC_PACKET_DEFAULT_SIZE);
+ if (!tmp) {
+ silc_free(packet);
+ return NULL;
}
+ silc_buffer_set(&packet->buffer, tmp, SILC_PACKET_DEFAULT_SIZE);
+ silc_buffer_reset(&packet->buffer);
- silc_buffer_pull(src, ret);
+ return packet;
}
- SILC_LOG_DEBUG(("Wrote data %d bytes", ret));
+ SILC_LOG_DEBUG(("Get packet %p", packet));
+
+ /* Delete from freelist */
+ silc_list_del(engine->packet_pool, packet);
+
+ silc_mutex_unlock(engine->lock);
+
+ return packet;
+}
+
+
+/******************************** Packet API ********************************/
+
+/* Allocate new packet engine */
+
+SilcPacketEngine
+silc_packet_engine_start(SilcRng rng, SilcBool router,
+ SilcPacketCallbacks *callbacks,
+ void *callback_context)
+{
+ SilcPacketEngine engine;
+ SilcPacket packet;
+ int i;
+ void *tmp;
+
+ SILC_LOG_DEBUG(("Starting new packet engine"));
+
+ if (!callbacks)
+ return NULL;
+ if (!callbacks->packet_receive || !callbacks->eos || !callbacks->error)
+ return NULL;
+
+ engine = silc_calloc(1, sizeof(*engine));
+ if (!engine)
+ return NULL;
+
+ engine->rng = rng;
+ engine->local_is_router = router;
+ engine->callbacks = callbacks;
+ engine->callback_context = callback_context;
+ silc_list_init(engine->streams, struct SilcPacketStreamStruct, next);
+ silc_mutex_alloc(&engine->lock);
+
+ /* Allocate packet free list */
+ silc_list_init(engine->packet_pool, struct SilcPacketStruct, next);
+ for (i = 0; i < 5; i++) {
+ packet = silc_calloc(1, sizeof(*packet));
+ if (!packet)
+ return NULL;
+
+ tmp = silc_malloc(SILC_PACKET_DEFAULT_SIZE);
+ if (!tmp)
+ return NULL;
+ silc_buffer_set(&packet->buffer, tmp, SILC_PACKET_DEFAULT_SIZE);
+ silc_buffer_reset(&packet->buffer);
+
+ silc_list_add(engine->packet_pool, packet);
+ }
+ silc_list_start(engine->packet_pool);
- return ret;
+ return engine;
}
-/* Reads data from the socket connection into the incoming data buffer.
- However, this does not parse the packet, it only reads some amount from
- the network. If there are more data available that can be read at a time
- the rest of the data will be read later with a timeout and only after
- that the packet is ready to be parsed.
+/* Stop packet engine */
+
+void silc_packet_engine_stop(SilcPacketEngine engine)
+{
- The destination buffer sent as argument must be initialized before
- calling this function, and, the data section and the start of the tail
- section must be same. Ie. we add the read data to the tail section of
- the buffer hence the data section is the start of the buffer.
+ SILC_LOG_DEBUG(("Stopping packet engine"));
- This returns amount of bytes read or -1 on error or -2 on case where
- all of the data could not be read at once. */
+ if (!engine)
+ return;
-int silc_packet_read(int sock, SilcBuffer dest)
+ /* XXX */
+
+ silc_free(engine);
+}
+
+/* Create new packet stream */
+
+SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
+ SilcSchedule schedule,
+ SilcStream stream)
{
- int len = 0;
- unsigned char buf[SILC_PACKET_READ_SIZE];
+ SilcPacketStream ps;
+ void *tmp;
+
+ SILC_LOG_DEBUG(("Creating new packet stream"));
+
+ if (!engine || !stream)
+ return NULL;
- SILC_LOG_DEBUG(("Reading data from socket %d", sock));
+ ps = silc_calloc(1, sizeof(*ps));
+ if (!ps)
+ return NULL;
+
+ ps->engine = engine;
+ ps->stream = stream;
+ ps->refcnt++;
+
+ /* Allocate buffers */
+ tmp = silc_malloc(SILC_PACKET_DEFAULT_SIZE);
+ if (!tmp)
+ return NULL;
+ silc_buffer_set(&ps->inbuf, tmp, SILC_PACKET_DEFAULT_SIZE);
+ silc_buffer_reset(&ps->inbuf);
+ tmp = silc_malloc(SILC_PACKET_DEFAULT_SIZE);
+ if (!tmp)
+ return NULL;
+ silc_buffer_set(&ps->outbuf, tmp, SILC_PACKET_DEFAULT_SIZE);
+ silc_buffer_reset(&ps->outbuf);
+
+ /* Initialize packet procesors list */
+ ps->process = silc_dlist_init();
+
+ /* Set IO notifier callback */
+ silc_stream_set_notifier(ps->stream, schedule, silc_packet_stream_io, ps);
+
+ silc_mutex_alloc(&ps->lock);
+
+ /* Add to engine */
+ silc_mutex_lock(engine->lock);
+ silc_list_add(engine->streams, ps);
+ silc_mutex_unlock(engine->lock);
+
+ return ps;
+}
- /* Read the data from the socket. */
- len = read(sock, buf, sizeof(buf));
- if (len < 0) {
- if (errno == EAGAIN) {
- SILC_LOG_DEBUG(("Could not read immediately, will do it later"));
- return -2;
+/* Destroy packet stream */
+
+void silc_packet_stream_destroy(SilcPacketStream stream)
+{
+ if (!stream)
+ return;
+
+ if (stream->refcnt > 1) {
+ stream->destroyed = TRUE;
+ return;
+ }
+
+ SILC_LOG_DEBUG(("Destroying packet stream %p", stream));
+
+ /* Delete from engine */
+ silc_mutex_lock(stream->engine->lock);
+ silc_list_del(stream->engine->streams, stream);
+ silc_mutex_unlock(stream->engine->lock);
+
+ /* Clear and free buffers */
+ silc_buffer_clear(&stream->inbuf);
+ silc_buffer_clear(&stream->outbuf);
+ silc_free(silc_buffer_steal(&stream->inbuf, NULL));
+ silc_free(silc_buffer_steal(&stream->outbuf, NULL));
+
+ silc_dlist_uninit(stream->process);
+
+ /* XXX */
+
+ silc_free(stream);
+}
+
+/* Marks as router stream */
+
+void silc_packet_stream_set_router(SilcPacketStream stream)
+{
+ stream->is_router = TRUE;
+}
+
+/* Links `callbacks' to `stream' for specified packet types */
+
+SilcBool silc_packet_stream_link(SilcPacketStream stream,
+ SilcPacketCallbacks *callbacks,
+ void *callback_context,
+ int priority, ...)
+{
+ va_list ap;
+ SilcPacketProcess p, e;
+ SilcInt32 packet_type;
+ int i;
+
+ SILC_LOG_DEBUG(("Linking callbacks %p to stream %p", callbacks, stream));
+
+ if (!callbacks)
+ return FALSE;
+ if (!callbacks->packet_receive)
+ return FALSE;
+
+ p = silc_calloc(1, sizeof(*p));
+ if (!p)
+ return FALSE;
+
+ p->priority = priority;
+ p->callbacks = callbacks;
+ p->callback_context = callback_context;
+
+ silc_mutex_lock(stream->lock);
+
+ if (!stream->process) {
+ stream->process = silc_dlist_init();
+ if (!stream->process)
+ return FALSE;
+ }
+
+ /* According to priority set the procesor to correct position. First
+ entry has the highest priority */
+ silc_dlist_start(stream->process);
+ while ((e = silc_dlist_get(stream->process)) != SILC_LIST_END) {
+ if (p->priority > e->priority) {
+ silc_dlist_insert(stream->process, p);
+ break;
}
- SILC_LOG_ERROR(("Cannot read from socket: %d", strerror(errno)));
- return -1;
}
+ if (!e)
+ silc_dlist_add(stream->process, p);
- if (!len)
- return 0;
+ silc_mutex_unlock(stream->lock);
+
+ /* Get packet types to process */
+ va_start(ap, priority);
+ i = 1;
+ while (1) {
+ packet_type = va_arg(ap, SilcInt32);
+
+ if (packet_type == SILC_PACKET_ANY)
+ break;
+
+ if (packet_type == -1)
+ break;
+
+ p->types = silc_realloc(p->types, sizeof(*p->types) * (i + 1));
+ if (!p->types)
+ return FALSE;
+
+ p->types[i - 1] = (SilcPacketType)packet_type;
+ i++;
+ }
+ if (p->types)
+ p->types[i - 1] = 0;
+ va_end(ap);
- /* Insert the data to the buffer. If the data doesn't fit to the
- buffer space is allocated for the buffer.
- XXX: I don't like this. -Pekka */
- if (dest) {
-
- /* If the data doesn't fit we just have to allocate a whole new
- data area */
- if (dest->truelen <= len) {
-
- /* Free the old buffer */
- memset(dest->head, 'F', dest->truelen);
- silc_free(dest->head);
-
- /* Allocate new data area */
- len += SILC_PACKET_DEFAULT_SIZE;
- dest->data = silc_calloc(len, sizeof(char));
- dest->truelen = len;
- dest->len = 0;
- dest->head = dest->data;
- dest->data = dest->data;
- dest->tail = dest->data;
- dest->end = dest->data + dest->truelen;
- len -= SILC_PACKET_DEFAULT_SIZE;
+ silc_packet_stream_ref(stream);
+
+ return TRUE;
+}
+
+/* Unlinks `callbacks' from `stream'. */
+
+void silc_packet_stream_unlink(SilcPacketStream stream,
+ SilcPacketCallbacks *callbacks,
+ void *callback_context)
+{
+ SilcPacketProcess p;
+
+ SILC_LOG_DEBUG(("Unlinking callbacks %p from stream %p",
+ callbacks, stream));
+
+ silc_mutex_lock(stream->lock);
+
+ silc_dlist_start(stream->process);
+ while ((p = silc_dlist_get(stream->process)) != SILC_LIST_END)
+ if (p->callbacks == callbacks &&
+ p->callback_context == callback_context) {
+ silc_dlist_del(stream->process, p);
+ silc_free(p);
+ break;
}
- silc_buffer_put_tail(dest, buf, len);
- silc_buffer_pull_tail(dest, len);
+ if (!silc_dlist_count(stream->process)) {
+ silc_dlist_uninit(stream->process);
+ stream->process = NULL;
}
- SILC_LOG_DEBUG(("Read %d bytes", len));
+ silc_mutex_unlock(stream->lock);
- return len;
+ silc_packet_stream_unref(stream);
}
-/* Encrypts a packet. */
+/* Reference packet stream */
-void silc_packet_encrypt(SilcCipher cipher, SilcBuffer buffer,
- unsigned int len)
+void silc_packet_stream_ref(SilcPacketStream stream)
{
- SILC_LOG_DEBUG(("Encrypting packet, cipher %s, len %d (%d)",
- cipher->cipher->name, len, len - 2));
+ silc_mutex_lock(stream->lock);
+ stream->refcnt++;
+ silc_mutex_unlock(stream->lock);
+}
- /* Encrypt the data area of the packet. 3 bytes of the packet
- are not encrypted. */
- cipher->cipher->encrypt(cipher->context, buffer->data + 2,
- buffer->data + 2, len - 2, cipher->iv);
+/* Unreference packet stream */
+void silc_packet_stream_unref(SilcPacketStream stream)
+{
+ silc_mutex_lock(stream->lock);
+ stream->refcnt--;
+ silc_mutex_unlock(stream->lock);
+ if (stream->refcnt == 0)
+ silc_packet_stream_destroy(stream);
}
-/* Decrypts a packet. */
+/* Return engine */
-void silc_packet_decrypt(SilcCipher cipher, SilcBuffer buffer,
- unsigned int len)
+SilcPacketEngine silc_packet_get_engine(SilcPacketStream stream)
{
- SILC_LOG_DEBUG(("Decrypting packet, cipher %s, len %d (%d)",
- cipher->cipher->name, len, len - 2));
+ return stream->engine;
+}
- /* Decrypt the data area of the packet. 2 bytes of the packet
- are not decrypted (they are not encrypted). */
- cipher->cipher->decrypt(cipher->context, buffer->data + 2,
- buffer->data + 2, len - 2, cipher->iv);
+/* Set application context for packet stream */
+void silc_packet_set_context(SilcPacketStream stream, void *stream_context)
+{
+ stream->stream_context = stream_context;
}
-/* Parses the packet. This is called when a whole packet is ready to be
- parsed. The buffer sent must be already decrypted before calling this
- function. The len argument must be the true length of the packet. This
- function returns the type of the packet. The data section of the
- buffer is parsed, not head or tail sections. */
+/* Return application context from packet stream */
-SilcPacketType silc_packet_parse(SilcPacketContext *ctx)
+void *silc_packet_get_context(SilcPacketStream stream)
{
- SilcBuffer buffer = ctx->buffer;
- int len;
+ return stream->stream_context;
+}
- SILC_LOG_DEBUG(("Parsing incoming packet"));
+/* Return underlaying stream */
+
+SilcStream silc_packet_stream_get_stream(SilcPacketStream stream)
+{
+ return stream->stream;
+}
+
+/* Set ciphers for packet stream */
+
+void silc_packet_set_ciphers(SilcPacketStream stream, SilcCipher send,
+ SilcCipher receive)
+{
+ SILC_LOG_DEBUG(("Setting new ciphers to packet stream"));
+ stream->send_key = send;
+ stream->receive_key = receive;
+}
+
+/* Return current ciphers from packet stream */
+
+SilcBool silc_packet_get_ciphers(SilcPacketStream stream, SilcCipher *send,
+ SilcCipher *receive)
+{
+ if (!stream->send_key && !stream->receive_key)
+ return FALSE;
+
+ if (send)
+ *send = stream->send_key;
+ if (receive)
+ *receive = stream->receive_key;
+
+ return TRUE;
+}
+
+/* Set HMACs for packet stream */
+
+void silc_packet_set_hmacs(SilcPacketStream stream, SilcHmac send,
+ SilcHmac receive)
+{
+ SILC_LOG_DEBUG(("Setting new HMACs to packet stream"));
+ stream->send_hmac = send;
+ stream->receive_hmac = receive;
+}
+
+/* Return current HMACs from packet stream */
- /* Check the length of the buffer */
- if (buffer->len < SILC_PACKET_MIN_LEN) {
- SILC_LOG_ERROR(("Bad packet length: %d, packet dropped", buffer->len));
- return SILC_PACKET_NONE;
+SilcBool silc_packet_get_hmacs(SilcPacketStream stream, SilcHmac *send,
+ SilcHmac *receive)
+{
+ if (!stream->send_hmac && !stream->receive_hmac)
+ return FALSE;
+
+ if (send)
+ *send = stream->send_hmac;
+ if (receive)
+ *receive = stream->receive_hmac;
+
+ return TRUE;
+}
+
+/* Set SILC IDs to packet stream */
+
+SilcBool silc_packet_set_ids(SilcPacketStream stream,
+ SilcIdType src_id_type, const void *src_id,
+ SilcIdType dst_id_type, const void *dst_id)
+{
+ SilcUInt32 len;
+ unsigned char tmp[32];
+
+ if (!src_id && !dst_id)
+ return FALSE;
+
+ SILC_LOG_DEBUG(("Setting new IDs to packet stream"));
+
+ if (src_id) {
+ silc_free(stream->src_id);
+ if (!silc_id_id2str(src_id, src_id_type, tmp, sizeof(tmp), &len))
+ return FALSE;
+ stream->src_id = silc_memdup(tmp, len);
+ if (!stream->src_id)
+ return FALSE;
+ stream->src_id_type = src_id_type;
+ stream->src_id_len = len;
}
- /* Parse the buffer. This parses the SILC header of the packet. */
- len = silc_buffer_unformat(buffer,
- SILC_STR_UI_SHORT(&ctx->truelen),
- SILC_STR_UI_CHAR(&ctx->flags),
- SILC_STR_UI_CHAR(&ctx->type),
- SILC_STR_UI_SHORT(&ctx->src_id_len),
- SILC_STR_UI_SHORT(&ctx->dst_id_len),
- SILC_STR_UI_CHAR(&ctx->src_id_type),
- SILC_STR_END);
+ if (dst_id) {
+ silc_free(stream->dst_id);
+ if (!silc_id_id2str(dst_id, dst_id_type, tmp, sizeof(tmp), &len))
+ return FALSE;
+ stream->dst_id = silc_memdup(tmp, len);
+ if (!stream->dst_id)
+ return FALSE;
+ stream->dst_id_type = dst_id_type;
+ stream->dst_id_len = len;
+ }
+
+ return TRUE;
+}
+
+/* Free packet */
+
+void silc_packet_free(SilcPacket packet)
+{
+ SilcPacketStream stream = packet->stream;
+
+ SILC_LOG_DEBUG(("Freeing packet %p", packet));
+
+#if defined(SILC_DEBUG)
+ /* Check for double free */
+ assert(packet->stream != NULL);
+#endif /* SILC_DEBUG */
+
+ silc_mutex_lock(stream->engine->lock);
+
+ packet->stream = NULL;
+ packet->src_id = packet->dst_id = NULL;
+ silc_buffer_reset(&packet->buffer);
+
+ /* Put the packet back to freelist */
+ silc_list_add(stream->engine->packet_pool, packet);
+
+ silc_mutex_unlock(stream->engine->lock);
+}
+
+/* Creates streamer */
+
+SilcStream silc_packet_streamer_create(SilcPacketStream stream,
+ SilcPacketType packet_type,
+ SilcPacketFlags packet_flags)
+{
+ /* XXX TODO */
+ return NULL;
+}
+
+/* Destroyes streamer */
+
+void silc_packet_streamer_destroy(SilcStream stream)
+{
+
+}
+
+
+/****************************** Packet Sending ******************************/
+
+/* Prepare outgoing data buffer for packet sending. Returns the
+ pointer to that buffer into the `packet'. */
+
+static SilcBool silc_packet_send_prepare(SilcPacketStream stream,
+ SilcUInt32 totlen,
+ SilcHmac hmac,
+ SilcBuffer packet)
+{
+ unsigned char *oldptr;
+ unsigned int mac_len = hmac ? silc_hmac_len(hmac) : 0;
+
+ totlen += mac_len;
- if (ctx->src_id_len > SILC_PACKET_MAX_ID_LEN ||
- ctx->dst_id_len > SILC_PACKET_MAX_ID_LEN) {
- SILC_LOG_ERROR(("Bad ID lengths in packet"));
- return SILC_PACKET_NONE;
+ /* Allocate more space if needed */
+ if (silc_buffer_taillen(&stream->outbuf) < totlen) {
+ if (!silc_buffer_realloc(&stream->outbuf,
+ silc_buffer_truelen(&stream->outbuf) + totlen))
+ return FALSE;
}
- /* Calculate length of padding in packet */
- ctx->padlen = SILC_PACKET_PADLEN(ctx->truelen);
+ /* Pull data area for the new packet, and return pointer to the start of
+ the data area and save the pointer in to the `packet'. MAC is pulled
+ later after it's computed. */
+ oldptr = silc_buffer_pull_tail(&stream->outbuf, totlen);
+ silc_buffer_set(packet, oldptr, totlen);
+ silc_buffer_push_tail(packet, mac_len);
- silc_buffer_pull(buffer, len);
- silc_buffer_unformat(buffer,
- SILC_STR_UI_XNSTRING_ALLOC(&ctx->src_id,
- ctx->src_id_len),
- SILC_STR_UI_CHAR(&ctx->dst_id_type),
- SILC_STR_UI_XNSTRING_ALLOC(&ctx->dst_id,
- ctx->dst_id_len),
- SILC_STR_UI_XNSTRING(NULL, ctx->padlen),
- SILC_STR_END);
- silc_buffer_push(buffer, len);
+ return TRUE;
+}
- SILC_LOG_HEXDUMP(("parsed packet, len %d", ctx->buffer->len),
- ctx->buffer->data, ctx->buffer->len);
+/* Internal routine to send packet */
+
+static SilcBool silc_packet_send_raw(SilcPacketStream stream,
+ SilcPacketType type,
+ SilcPacketFlags flags,
+ SilcIdType src_id_type,
+ unsigned char *src_id,
+ SilcUInt32 src_id_len,
+ SilcIdType dst_id_type,
+ unsigned char *dst_id,
+ SilcUInt32 dst_id_len,
+ const unsigned char *data,
+ SilcUInt32 data_len,
+ SilcCipher cipher,
+ SilcHmac hmac)
+{
+ unsigned char tmppad[SILC_PACKET_MAX_PADLEN];
+ int block_len = (cipher ? silc_cipher_get_block_len(cipher) : 0);
+ int i, enclen, truelen, padlen;
+ SilcBufferStruct packet;
- /* Pull SILC header and padding from packet */
- silc_buffer_pull(buffer, SILC_PACKET_HEADER_LEN +
- ctx->src_id_len + ctx->dst_id_len + ctx->padlen);
+ SILC_LOG_DEBUG(("Sending packet %s (%d) flags %d, src %d dst %d,"
+ "data len %d", silc_get_packet_name(type), stream->send_psn,
+ flags, src_id_type, dst_id_type, data_len));
+
+ /* Get the true length of the packet. This is saved as payload length
+ into the packet header. This does not include the length of the
+ padding. */
+ data_len = SILC_PACKET_DATALEN(data_len, (SILC_PACKET_HEADER_LEN +
+ src_id_len + dst_id_len));
+ enclen = truelen = (data_len + SILC_PACKET_HEADER_LEN +
+ src_id_len + dst_id_len);
+
+ /* We automatically figure out the packet structure from the packet
+ type and flags, and calculate correct length. Private messages with
+ private keys and channel messages are special packets as their
+ payload is encrypted already. */
+ if ((type == SILC_PACKET_PRIVATE_MESSAGE &&
+ flags & SILC_PACKET_FLAG_PRIVMSG_KEY) ||
+ type == SILC_PACKET_CHANNEL_MESSAGE) {
+
+ /* Padding is calculated from header + IDs */
+ SILC_PACKET_PADLEN((SILC_PACKET_HEADER_LEN +
+ src_id_len +
+ dst_id_len), block_len, padlen);
+
+ /* Length to encrypt, header + IDs + padding. */
+ enclen = SILC_PACKET_HEADER_LEN + src_id_len + dst_id_len + padlen;
+ } else {
+
+ /* Padding is calculated from true length of the packet */
+ if (flags & SILC_PACKET_FLAG_LONG_PAD)
+ SILC_PACKET_PADLEN_MAX(truelen, block_len, padlen);
+ else
+ SILC_PACKET_PADLEN(truelen, block_len, padlen);
+
+ enclen += padlen;
+ }
+
+ /* Remove implementation specific flags */
+ flags &= ~(SILC_PACKET_FLAG_LONG_PAD);
+
+ /* Get random padding */
+ for (i = 0; i < padlen; i++) tmppad[i] =
+ silc_rng_get_byte_fast(stream->engine->rng);
+
+ silc_mutex_lock(stream->lock);
+
+ /* Get packet pointer from the outgoing buffer */
+ if (!silc_packet_send_prepare(stream, truelen + padlen, hmac, &packet)) {
+ silc_mutex_unlock(stream->lock);
+ return FALSE;
+ }
+
+ /* Create the packet. This creates the SILC header, adds padding, and
+ the actual packet data. */
+ i = silc_buffer_format(&packet,
+ SILC_STR_UI_SHORT(truelen),
+ SILC_STR_UI_CHAR(flags),
+ SILC_STR_UI_CHAR(type),
+ SILC_STR_UI_CHAR(padlen),
+ SILC_STR_UI_CHAR(0),
+ SILC_STR_UI_CHAR(src_id_len),
+ SILC_STR_UI_CHAR(dst_id_len),
+ SILC_STR_UI_CHAR(src_id_type),
+ SILC_STR_UI_XNSTRING(src_id, src_id_len),
+ SILC_STR_UI_CHAR(dst_id_type),
+ SILC_STR_UI_XNSTRING(dst_id, dst_id_len),
+ SILC_STR_UI_XNSTRING(tmppad, padlen),
+ SILC_STR_UI_XNSTRING(data, data_len),
+ SILC_STR_END);
+ if (i < 0) {
+ silc_mutex_unlock(stream->lock);
+ return FALSE;
+ }
+
+ SILC_LOG_HEXDUMP(("Assembled packet, len %d", silc_buffer_len(&packet)),
+ packet.data, silc_buffer_len(&packet));
- SILC_LOG_DEBUG(("Incoming packet type: %d", ctx->type));
+ /* Encrypt the packet */
+ if (cipher)
+ if (!silc_cipher_encrypt(cipher, packet.data, packet.data,
+ enclen, NULL)) {
+ SILC_LOG_ERROR(("Packet encryption failed"));
+ silc_mutex_unlock(stream->lock);
+ return FALSE;
+ }
+
+ /* Compute HMAC */
+ if (hmac) {
+ unsigned char psn[4];
+ SilcUInt32 mac_len;
+
+ /* MAC is computed from the entire encrypted packet data, and put
+ to the end of the packet. */
+ silc_hmac_init(hmac);
+ SILC_PUT32_MSB(stream->send_psn, psn);
+ silc_hmac_update(hmac, psn, 4);
+ silc_hmac_update(hmac, packet.data, silc_buffer_len(&packet));
+ silc_hmac_final(hmac, packet.tail, &mac_len);
+ silc_buffer_pull_tail(&packet, mac_len);
+ stream->send_psn++;
+ }
+
+ /* Write the packet to the stream */
+ while (silc_buffer_len(&stream->outbuf) > 0) {
+ i = silc_stream_write(stream->stream, stream->outbuf.data,
+ silc_buffer_len(&stream->outbuf));
+ if (i == 0) {
+ /* EOS */
+ silc_buffer_reset(&stream->outbuf);
+ silc_mutex_unlock(stream->lock);
+ SILC_PACKET_CALLBACK_EOS(stream);
+ return FALSE;
+ }
+
+ if (i == -2) {
+ /* Error */
+ silc_buffer_reset(&stream->outbuf);
+ silc_mutex_unlock(stream->lock);
+ SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_WRITE);
+ return FALSE;
+ }
- return ctx->type;
+ if (i == -1) {
+ /* Cannot write now, write later. */
+ silc_mutex_unlock(stream->lock);
+ return TRUE;
+ }
+
+ /* Wrote data */
+ silc_buffer_pull(&stream->outbuf, i);
+ }
+ silc_buffer_reset(&stream->outbuf);
+
+ silc_mutex_unlock(stream->lock);
+ return TRUE;
}
-/* Perform special SILC Packet header parsing. This is required to some
- packet types that have the data payload encrypted with different key
- than the header area plus padding of the packet. Hence, this parses
- the header in a way that it does not take the data area into account
- and parses the header and padding area only. */
+/* Sends a packet */
-SilcPacketType silc_packet_parse_special(SilcPacketContext *ctx)
+SilcBool silc_packet_send(SilcPacketStream stream,
+ SilcPacketType type, SilcPacketFlags flags,
+ const unsigned char *data, SilcUInt32 data_len)
{
- SilcBuffer buffer = ctx->buffer;
- int len, tmplen;
+ return silc_packet_send_raw(stream, type, flags,
+ stream->src_id_type,
+ stream->src_id,
+ stream->src_id_len,
+ stream->dst_id_type,
+ stream->dst_id,
+ stream->dst_id_len,
+ data, data_len,
+ stream->send_key,
+ stream->send_hmac);
+}
+
+/* Sends a packet, extended routine */
+
+SilcBool silc_packet_send_ext(SilcPacketStream stream,
+ SilcPacketType type, SilcPacketFlags flags,
+ SilcIdType src_id_type, void *src_id,
+ SilcIdType dst_id_type, void *dst_id,
+ const unsigned char *data, SilcUInt32 data_len,
+ SilcCipher cipher, SilcHmac hmac)
+{
+ unsigned char src_id_data[32], dst_id_data[32];
+ SilcUInt32 src_id_len, dst_id_len;
+
+ if (src_id)
+ if (!silc_id_id2str(src_id, src_id_type, src_id_data,
+ sizeof(src_id_data), &src_id_len))
+ return FALSE;
+ if (dst_id)
+ if (!silc_id_id2str(dst_id, dst_id_type, dst_id_data,
+ sizeof(dst_id_data), &dst_id_len))
+ return FALSE;
+
+ return silc_packet_send_raw(stream, type, flags,
+ src_id_type,
+ src_id_data,
+ src_id_len,
+ dst_id_type,
+ dst_id_data,
+ dst_id_len,
+ data, data_len,
+ cipher,
+ hmac);
+}
+
+
+/***************************** Packet Receiving *****************************/
+
+/* Checks MAC in the packet. Returns TRUE if MAC is Ok. */
+
+static SilcBool silc_packet_check_mac(SilcHmac hmac,
+ const unsigned char *data,
+ SilcUInt32 data_len,
+ const unsigned char *packet_mac,
+ SilcUInt32 sequence)
+{
+ /* Check MAC */
+ if (hmac) {
+ unsigned char mac[32], psn[4];
+ SilcUInt32 mac_len;
+
+ SILC_LOG_DEBUG(("Verifying MAC"));
+
+ /* Compute HMAC of packet */
+ silc_hmac_init(hmac);
+ SILC_PUT32_MSB(sequence, psn);
+ silc_hmac_update(hmac, psn, 4);
+ silc_hmac_update(hmac, data, data_len);
+ silc_hmac_final(hmac, mac, &mac_len);
+
+ /* Compare the MAC's */
+ if (memcmp(packet_mac, mac, mac_len)) {
+ SILC_LOG_DEBUG(("MAC failed"));
+ return FALSE;
+ }
+
+ SILC_LOG_DEBUG(("MAC is Ok"));
+ }
+
+ return TRUE;
+}
+
+/* Decrypts SILC packet. Handles both normal and special packet decryption.
+ Return 0 when packet is normal and 1 when it it special, -1 on error. */
+
+static int silc_packet_decrypt(SilcCipher cipher, SilcHmac hmac,
+ SilcUInt32 sequence, SilcBuffer buffer,
+ SilcBool normal)
+{
+ if (normal == TRUE) {
+ if (cipher) {
+ /* Decrypt rest of the packet */
+ SILC_LOG_DEBUG(("Decrypting the packet"));
+ if (!silc_cipher_decrypt(cipher, buffer->data, buffer->data,
+ silc_buffer_len(buffer), NULL))
+ return -1;
+ }
+ return 0;
+
+ } else {
+ /* Decrypt rest of the header plus padding */
+ if (cipher) {
+ SilcUInt16 len;
+ SilcUInt32 block_len = silc_cipher_get_block_len(cipher);
+
+ SILC_LOG_DEBUG(("Decrypting the header"));
+
+ /* Padding length + src id len + dst id len + header length - 16
+ bytes already decrypted, gives the rest of the encrypted packet */
+ silc_buffer_push(buffer, block_len);
+ len = (((SilcUInt8)buffer->data[4] + (SilcUInt8)buffer->data[6] +
+ (SilcUInt8)buffer->data[7] + SILC_PACKET_HEADER_LEN) -
+ block_len);
+ silc_buffer_pull(buffer, block_len);
+
+ if (len > silc_buffer_len(buffer)) {
+ SILC_LOG_ERROR(("Garbage in header of packet, bad packet length, "
+ "packet dropped"));
+ return -1;
+ }
+ if (!silc_cipher_decrypt(cipher, buffer->data, buffer->data,
+ len, NULL))
+ return -1;
+ }
+
+ return 1;
+ }
+}
+
+/* Parses the packet. This is called when a whole packet is ready to be
+ parsed. The buffer sent must be already decrypted before calling this
+ function. */
+
+static SilcBool silc_packet_parse(SilcPacket packet)
+{
+ SilcBuffer buffer = &packet->buffer;
+ SilcUInt8 padlen = (SilcUInt8)buffer->data[4];
+ SilcUInt8 src_id_len, dst_id_len, src_id_type, dst_id_type;
+ int len, ret;
SILC_LOG_DEBUG(("Parsing incoming packet"));
- /* Check the length of the buffer */
- if (buffer->len < SILC_PACKET_MIN_LEN) {
- SILC_LOG_ERROR(("Bad packet length: %d, packet dropped", buffer->len));
- return SILC_PACKET_NONE;
+ /* Parse the buffer. This parses the SILC header of the packet. */
+ len = silc_buffer_unformat(buffer,
+ SILC_STR_OFFSET(6),
+ SILC_STR_UI_CHAR(&src_id_len),
+ SILC_STR_UI_CHAR(&dst_id_len),
+ SILC_STR_UI_CHAR(&src_id_type),
+ SILC_STR_END);
+ if (len == -1) {
+ SILC_LOG_ERROR(("Malformed packet header, packet dropped"));
+ return FALSE;
+ }
+
+ if (src_id_len > SILC_PACKET_MAX_ID_LEN ||
+ dst_id_len > SILC_PACKET_MAX_ID_LEN) {
+ SILC_LOG_ERROR(("Bad ID lengths in packet (%d and %d)",
+ packet->src_id_len, packet->dst_id_len));
+ return FALSE;
}
- /* Parse the buffer. This parses the SILC header of the packet. */
- len = silc_buffer_unformat(buffer,
- SILC_STR_UI_SHORT(&ctx->truelen),
- SILC_STR_UI_CHAR(&ctx->flags),
- SILC_STR_UI_CHAR(&ctx->type),
- SILC_STR_UI_SHORT(&ctx->src_id_len),
- SILC_STR_UI_SHORT(&ctx->dst_id_len),
- SILC_STR_UI_CHAR(&ctx->src_id_type),
+ ret = silc_buffer_unformat(buffer,
+ SILC_STR_OFFSET(len),
+ SILC_STR_UI_XNSTRING(&packet->src_id,
+ src_id_len),
+ SILC_STR_UI_CHAR(&dst_id_type),
+ SILC_STR_UI_XNSTRING(&packet->dst_id,
+ dst_id_len),
+ SILC_STR_OFFSET(padlen),
SILC_STR_END);
+ if (ret == -1) {
+ SILC_LOG_ERROR(("Malformed packet header, packet dropped"));
+ return FALSE;
+ }
- if (ctx->src_id_len > SILC_PACKET_MAX_ID_LEN ||
- ctx->dst_id_len > SILC_PACKET_MAX_ID_LEN) {
- SILC_LOG_ERROR(("Bad ID lengths in packet"));
- return SILC_PACKET_NONE;
+ if (src_id_type > SILC_ID_CHANNEL ||
+ dst_id_type > SILC_ID_CHANNEL) {
+ SILC_LOG_ERROR(("Bad ID types in packet (%d and %d)",
+ src_id_type, dst_id_type));
+ return FALSE;
}
- /* Calculate length of padding in packet. As this is special packet
- the data area is not used in the padding calculation as it won't
- be decrypted by the caller. */
- tmplen = SILC_PACKET_HEADER_LEN + ctx->src_id_len + ctx->dst_id_len;
- ctx->padlen = SILC_PACKET_PADLEN(tmplen);
-
- silc_buffer_pull(buffer, len);
- silc_buffer_unformat(buffer,
- SILC_STR_UI_XNSTRING_ALLOC(&ctx->src_id,
- ctx->src_id_len),
- SILC_STR_UI_CHAR(&ctx->dst_id_type),
- SILC_STR_UI_XNSTRING_ALLOC(&ctx->dst_id,
- ctx->dst_id_len),
- SILC_STR_UI_XNSTRING(NULL, ctx->padlen),
- SILC_STR_END);
- silc_buffer_push(buffer, len);
-
- SILC_LOG_HEXDUMP(("parsed packet, len %d", ctx->buffer->len),
- ctx->buffer->data, ctx->buffer->len);
-
- /* Pull SILC header and padding from packet */
+ packet->src_id_len = src_id_len;
+ packet->dst_id_len = dst_id_len;
+ packet->src_id_type = src_id_type;
+ packet->dst_id_type = dst_id_type;
+
+ SILC_LOG_HEXDUMP(("Parsed packet, len %d", silc_buffer_len(buffer)),
+ buffer->data, silc_buffer_len(buffer));
+
+ /* Pull SILC header and padding from packet to get the data payload */
silc_buffer_pull(buffer, SILC_PACKET_HEADER_LEN +
- ctx->src_id_len + ctx->dst_id_len + ctx->padlen);
+ packet->src_id_len + packet->dst_id_len + padlen);
- SILC_LOG_DEBUG(("Incoming packet type: %d", ctx->type));
+ SILC_LOG_DEBUG(("Incoming packet type: %d (%s)", packet->type,
+ silc_get_packet_name(packet->type)));
- return ctx->type;
+ return TRUE;
}
-/* Assembles a new packet to be ready for send out. The buffer sent as
- argument must include the data to be sent and it must not be encrypted.
- The packet also must have enough free space so that the SILC header
- and padding maybe added to the packet. The packet is encrypted after
- this function has returned.
+/* Dispatch packet to application */
- The buffer sent as argument should be something like following:
+static void silc_packet_dispatch(SilcPacket packet)
+{
+ SilcPacketStream stream = packet->stream;
+ SilcPacketProcess p;
+ SilcBool default_sent = FALSE;
+ SilcPacketType *pt;
+
+ /* Parse the packet */
+ if (!silc_packet_parse(packet)) {
+ SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MALFORMED);
+ silc_packet_free(packet);
+ return;
+ }
- --------------------------------------------
- | head | data | tail |
- --------------------------------------------
- ^ ^
- 58 bytes x bytes
+ /* Dispatch packet to all packet processors that want it */
+
+ if (!stream->process) {
+ /* Send to default processor as no others exist */
+ SILC_LOG_DEBUG(("Dispatching packet to default callbacks"));
+ if (!stream->engine->callbacks->
+ packet_receive(stream->engine, stream, packet,
+ stream->engine->callback_context,
+ stream->stream_context))
+ silc_packet_free(packet);
+ return;
+ }
- So that the SILC header and 1 - 16 bytes of padding can fit to
- the buffer. After assembly the buffer might look like this:
+ silc_dlist_start(stream->process);
+ while ((p = silc_dlist_get(stream->process)) != SILC_LIST_END) {
+
+ /* If priority is 0 or less, we send to default processor first
+ because default processor has 0 priority */
+ if (!default_sent && p->priority <= 0) {
+ SILC_LOG_DEBUG(("Dispatching packet to default callbacks"));
+ default_sent = TRUE;
+ if (stream->engine->callbacks->
+ packet_receive(stream->engine, stream, packet,
+ stream->engine->callback_context,
+ stream->stream_context)) {
+ return;
+ }
+ }
- --------------------------------------------
- | data | |
- --------------------------------------------
- ^ ^
- Start of assembled packet
+ /* Send to processor */
+ if (!p->types) {
+ /* Send all packet types */
+ SILC_LOG_DEBUG(("Dispatching packet to %p callbacks", p->callbacks));
+ if (p->callbacks->packet_receive(stream->engine, stream, packet,
+ p->callback_context,
+ stream->stream_context))
+ return;
+ } else {
+ /* Send specific types */
+ for (pt = p->types; *pt; pt++)
+ if (*pt == packet->type) {
+ SILC_LOG_DEBUG(("Dispatching packet to %p callbacks",
+ p->callbacks));
+ if (p->callbacks->packet_receive(stream->engine, stream, packet,
+ p->callback_context,
+ stream->stream_context))
+ return;
+ break;
+ }
+ }
+ }
- Packet construct is as follows (* = won't be encrypted):
+ if (!default_sent) {
+ /* Send to default processor as it has not been sent yet */
+ SILC_LOG_DEBUG(("Dispatching packet to default callbacks"));
+ if (stream->engine->callbacks->
+ packet_receive(stream->engine, stream, packet,
+ stream->engine->callback_context,
+ stream->stream_context))
+ return;
+ }
- x bytes SILC Header
- 2 bytes Payload length (*)
- 1 byte Flags (*)
- 1 byte Packet type
- 1 byte Source ID Type
- 2 bytes Source ID Length
- x bytes Source ID
- 1 byte Destination ID Type
- 2 bytes Destination ID Length
- x bytes Destination ID
+ /* If we got here, no one wanted the packet, so drop it */
+ silc_packet_free(packet);
+}
- 1 - 16 bytes Padding
+/* Process incoming data and parse packets. */
- x bytes Data payload
+static void silc_packet_read_process(SilcPacketStream stream)
+{
+ SilcPacket packet;
+ SilcUInt16 packetlen;
+ SilcUInt32 paddedlen, mac_len, block_len;
+ unsigned char tmp[SILC_PACKET_MIN_HEADER_LEN], *header;
+ unsigned char iv[SILC_CIPHER_MAX_IV_SIZE];
+ SilcBool normal = TRUE;
+ int ret;
+
+ /* Parse the packets from the data */
+ while (silc_buffer_len(&stream->inbuf) > 0) {
+
+ if (silc_buffer_len(&stream->inbuf) < SILC_PACKET_MIN_HEADER_LEN) {
+ SILC_LOG_DEBUG(("Partial packet in queue, waiting for the rest"));
+ return;
+ }
- All fields in the packet will be authenticated by MAC. The MAC is
- not computed here, it must be computed differently before encrypting
- the packet.
+ if (stream->receive_hmac)
+ mac_len = silc_hmac_len(stream->receive_hmac);
+ else
+ mac_len = 0;
+
+ /* Decrypt first block of the packet to get the length field out */
+ if (stream->receive_key) {
+ block_len = silc_cipher_get_block_len(stream->receive_key);
+ memcpy(iv, silc_cipher_get_iv(stream->receive_key), block_len);
+ silc_cipher_decrypt(stream->receive_key, stream->inbuf.data,
+ tmp, block_len, iv);
+ header = tmp;
+ } else {
+ block_len = SILC_PACKET_MIN_HEADER_LEN;
+ header = stream->inbuf.data;
+ }
-*/
+ /* Get packet length and full packet length with padding */
+ SILC_PACKET_LENGTH(header, packetlen, paddedlen);
-void silc_packet_assemble(SilcPacketContext *ctx)
-{
- unsigned char tmppad[SILC_PACKET_MAX_PADLEN];
- int i;
+ /* Sanity checks */
+ if (packetlen < SILC_PACKET_MIN_LEN) {
+ SILC_LOG_ERROR(("Received too short packet"));
+ SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MALFORMED);
+ memset(tmp, 0, sizeof(tmp));
+ silc_buffer_reset(&stream->inbuf);
+ return;
+ }
- SILC_LOG_DEBUG(("Assembling outgoing packet"));
-
- /* Get the true length of the packet. This is saved as payload length
- into the packet header. This does not include the length of the
- padding. */
- if (!ctx->truelen)
- ctx->truelen = ctx->buffer->len + SILC_PACKET_HEADER_LEN +
- ctx->src_id_len + ctx->dst_id_len;
+ if (silc_buffer_len(&stream->inbuf) < paddedlen + mac_len) {
+ SILC_LOG_DEBUG(("Received partial packet, waiting for the rest "
+ "(%d bytes)",
+ paddedlen + mac_len - silc_buffer_len(&stream->inbuf)));
+ memset(tmp, 0, sizeof(tmp));
+ return;
+ }
- /* Calculate the length of the padding. The padding is calculated from
- the data that will be encrypted. As protocol states 3 first bytes
- of the packet are not encrypted they are not included in the
- padding calculation. */
- if (!ctx->padlen)
- ctx->padlen = SILC_PACKET_PADLEN(ctx->truelen);
+ /* Check MAC of the packet */
+ if (!silc_packet_check_mac(stream->receive_hmac, stream->inbuf.data,
+ paddedlen, stream->inbuf.data + paddedlen,
+ stream->receive_psn)) {
+ SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_MAC_FAILED);
+ memset(tmp, 0, sizeof(tmp));
+ silc_buffer_reset(&stream->inbuf);
+ return;
+ }
- /* Put the start of the data section to the right place. */
- silc_buffer_push(ctx->buffer, SILC_PACKET_HEADER_LEN +
- ctx->src_id_len + ctx->dst_id_len + ctx->padlen);
+ /* Get packet */
+ packet = silc_packet_alloc(stream->engine);
+ if (!packet) {
+ SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_NO_MEMORY);
+ memset(tmp, 0, sizeof(tmp));
+ silc_buffer_reset(&stream->inbuf);
+ return;
+ }
- /* Get random padding */
-#if 1
- for (i = 0; i < ctx->padlen; i++)
- tmppad[i] = silc_rng_get_byte(ctx->rng);
-#else
- /* XXX: For testing - to be removed */
- memset(tmppad, 65, sizeof(tmppad));
-#endif
-
- /* Create the packet. This creates the SILC header and adds padding,
- rest of the buffer remains as it is. */
- silc_buffer_format(ctx->buffer,
- SILC_STR_UI_SHORT(ctx->truelen),
- SILC_STR_UI_CHAR(ctx->flags),
- SILC_STR_UI_CHAR(ctx->type),
- SILC_STR_UI_SHORT(ctx->src_id_len),
- SILC_STR_UI_SHORT(ctx->dst_id_len),
- SILC_STR_UI_CHAR(ctx->src_id_type),
- SILC_STR_UI_XNSTRING(ctx->src_id, ctx->src_id_len),
- SILC_STR_UI_CHAR(ctx->dst_id_type),
- SILC_STR_UI_XNSTRING(ctx->dst_id, ctx->dst_id_len),
- SILC_STR_UI_XNSTRING(tmppad, ctx->padlen),
- SILC_STR_END);
-
- SILC_LOG_HEXDUMP(("Assembled packet, len %d", ctx->buffer->len),
- ctx->buffer->data, ctx->buffer->len);
-
- SILC_LOG_DEBUG(("Outgoing packet assembled"));
+ /* Allocate more space to packet buffer, if needed */
+ if (silc_buffer_truelen(&packet->buffer) < paddedlen) {
+ if (!silc_buffer_realloc(&packet->buffer,
+ silc_buffer_truelen(&packet->buffer) +
+ (paddedlen -
+ silc_buffer_truelen(&packet->buffer)))) {
+ SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_NO_MEMORY);
+ silc_packet_free(packet);
+ memset(tmp, 0, sizeof(tmp));
+ silc_buffer_reset(&stream->inbuf);
+ return;
+ }
+ }
+
+ /* Parse packet header */
+ packet->flags = (SilcPacketFlags)header[2];
+ packet->type = (SilcPacketType)header[3];
+
+ if (stream->engine->local_is_router) {
+ if (packet->type == SILC_PACKET_PRIVATE_MESSAGE &&
+ (packet->flags & SILC_PACKET_FLAG_PRIVMSG_KEY))
+ normal = FALSE;
+ else if (packet->type != SILC_PACKET_CHANNEL_MESSAGE ||
+ (packet->type == SILC_PACKET_CHANNEL_MESSAGE &&
+ stream->is_router == TRUE))
+ normal = TRUE;
+ } else {
+ if (packet->type == SILC_PACKET_PRIVATE_MESSAGE &&
+ (packet->flags & SILC_PACKET_FLAG_PRIVMSG_KEY))
+ normal = FALSE;
+ else if (packet->type != SILC_PACKET_CHANNEL_MESSAGE)
+ normal = TRUE;
+ }
+
+ SILC_LOG_HEXDUMP(("Incoming packet (%d) len %d",
+ stream->receive_psn, paddedlen + mac_len),
+ stream->inbuf.data, paddedlen + mac_len);
+
+ /* Put the decrypted part, and rest of the encrypted data, and decrypt */
+ silc_buffer_pull_tail(&packet->buffer, paddedlen);
+ silc_buffer_put(&packet->buffer, header, block_len);
+ silc_buffer_pull(&packet->buffer, block_len);
+ silc_buffer_put(&packet->buffer, stream->inbuf.data + block_len,
+ paddedlen - block_len);
+ if (stream->receive_key) {
+ silc_cipher_set_iv(stream->receive_key, iv);
+ ret = silc_packet_decrypt(stream->receive_key, stream->receive_hmac,
+ stream->receive_psn, &packet->buffer, normal);
+ if (ret < 0) {
+ SILC_PACKET_CALLBACK_ERROR(stream, SILC_PACKET_ERR_DECRYPTION_FAILED);
+ silc_packet_free(packet);
+ memset(tmp, 0, sizeof(tmp));
+ return;
+ }
+
+ stream->receive_psn++;
+ }
+ silc_buffer_push(&packet->buffer, block_len);
+
+ /* Pull the packet from inbuf thus we'll get the next one in the inbuf. */
+ silc_buffer_pull(&stream->inbuf, paddedlen + mac_len);
+
+ /* Dispatch the packet to application */
+ packet->stream = stream;
+ silc_packet_dispatch(packet);
+ }
+
+ silc_buffer_reset(&stream->inbuf);
}
projects / silc.git / blobdiff