Packet streams: make packet handling callback pointers read only.

[silc.git] / lib / silccore / silcpacket.c

diff --git a/lib/silccore/silcpacket.c b/lib/silccore/silcpacket.c
index bea6357939731b0db4ba92ed16cda2cab5e83e9d..2c01e6dd65fb1886d7723e83b081dff1a82e54e0 100644 (file)
--- a/lib/silccore/silcpacket.c
+++ b/lib/silccore/silcpacket.c
@@ -4,7 +4,7 @@
 
   Author: Pekka Riikonen <priikone@silcnet.org>
 
-  Copyright (C) 1997 - 2007 Pekka Riikonen
+  Copyright (C) 1997 - 2008 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
@@ -40,7 +40,7 @@ struct SilcPacketEngineStruct {
   SilcMutex lock;                       /* Engine lock */
   SilcRng rng;                          /* RNG for engine */
   SilcHashTable contexts;               /* Per scheduler contexts */
-  SilcPacketCallbacks *callbacks;       /* Packet callbacks */
+  const SilcPacketCallbacks *callbacks;         /* Packet callbacks */
   void *callback_context;               /* Context for callbacks */
   SilcList streams;                     /* All streams in engine */
   SilcList packet_pool;                 /* Free list for received packets */
@@ -51,7 +51,7 @@ struct SilcPacketEngineStruct {
 /* Packet processor context */
 typedef struct SilcPacketProcessStruct {
   SilcPacketType *types;                /* Packets to process */
-  SilcPacketCallbacks *callbacks;       /* Callbacks or NULL */
+  const SilcPacketCallbacks *callbacks;         /* Callbacks or NULL */
   void *callback_context;
   SilcInt32 priority;                   /* Priority */
 } *SilcPacketProcess;
@@ -336,7 +336,6 @@ static inline SilcBool silc_packet_stream_read(SilcPacketStream ps,
        silc_mutex_unlock(ps->lock);
        if (ret == -1) {
          /* Cannot read now, do it later. */
-         silc_buffer_pull(inbuf, silc_buffer_len(inbuf));
          return FALSE;
        }
 
@@ -394,7 +393,6 @@ static inline SilcBool silc_packet_stream_read(SilcPacketStream ps,
 
     if (ret == -1) {
       /* Cannot read now, do it later. */
-      silc_buffer_pull(inbuf, silc_buffer_len(inbuf));
       return FALSE;
     }
 
@@ -542,7 +540,7 @@ static void silc_packet_engine_context_destr(void *key, void *context,
 
 SilcPacketEngine
 silc_packet_engine_start(SilcRng rng, SilcBool router,
-                        SilcPacketCallbacks *callbacks,
+                        const SilcPacketCallbacks *callbacks,
                         void *callback_context)
 {
   SilcPacketEngine engine;
@@ -623,7 +621,7 @@ void silc_packet_engine_stop(SilcPacketEngine engine)
   silc_free(engine);
 }
 
-static const char *packet_error[] = {
+static const char * const packet_error[] = {
   "Cannot read from stream",
   "Cannot write to stream",
   "Packet MAC failed",
@@ -723,8 +721,8 @@ SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
                            (void *)&ps->sc)) {
     ps->sc = silc_calloc(1, sizeof(*ps->sc));
     if (!ps->sc) {
-      silc_packet_stream_destroy(ps);
       silc_mutex_unlock(engine->lock);
+      silc_packet_stream_destroy(ps);
       return NULL;
     }
     ps->sc->engine = engine;
@@ -735,8 +733,8 @@ SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
     if (!inbuf) {
       silc_free(ps->sc);
       ps->sc = NULL;
-      silc_packet_stream_destroy(ps);
       silc_mutex_unlock(engine->lock);
+      silc_packet_stream_destroy(ps);
       return NULL;
     }
     silc_buffer_reset(inbuf);
@@ -746,8 +744,8 @@ SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
       silc_buffer_free(inbuf);
       silc_free(ps->sc);
       ps->sc = NULL;
-      silc_packet_stream_destroy(ps);
       silc_mutex_unlock(engine->lock);
+      silc_packet_stream_destroy(ps);
       return NULL;
     }
     silc_dlist_add(ps->sc->inbufs, inbuf);
@@ -758,8 +756,8 @@ SilcPacketStream silc_packet_stream_create(SilcPacketEngine engine,
       silc_dlist_del(ps->sc->inbufs, inbuf);
       silc_free(ps->sc);
       ps->sc = NULL;
-      silc_packet_stream_destroy(ps);
       silc_mutex_unlock(engine->lock);
+      silc_packet_stream_destroy(ps);
       return NULL;
     }
   }
@@ -887,6 +885,8 @@ void silc_packet_stream_destroy(SilcPacketStream stream)
     return;
 
   if (silc_atomic_sub_int8(&stream->refcnt, 1) > 0) {
+    if (stream->destroyed)
+      return;
     stream->destroyed = TRUE;
 
     SILC_LOG_DEBUG(("Marking packet stream %p destroyed", stream));
@@ -901,17 +901,18 @@ void silc_packet_stream_destroy(SilcPacketStream stream)
 
   if (!stream->udp) {
     /* Delete from engine */
-    engine = stream->sc->engine;
-    silc_mutex_lock(engine->lock);
-    silc_list_del(engine->streams, stream);
-
-    /* Remove per scheduler context, if it is not used anymore */
     if (stream->sc) {
+      engine = stream->sc->engine;
+      silc_mutex_lock(engine->lock);
+      silc_list_del(engine->streams, stream);
+
+      /* Remove per scheduler context, if it is not used anymore */
       stream->sc->stream_count--;
       if (!stream->sc->stream_count)
        silc_hash_table_del(engine->contexts, stream->sc->schedule);
+
+      silc_mutex_unlock(engine->lock);
     }
-    silc_mutex_unlock(engine->lock);
 
     /* Destroy the underlaying stream */
     if (stream->stream)
@@ -1000,7 +1001,7 @@ void silc_packet_stream_set_iv_included(SilcPacketStream stream)
 /* Links `callbacks' to `stream' for specified packet types */
 
 static SilcBool silc_packet_stream_link_va(SilcPacketStream stream,
-                                          SilcPacketCallbacks *callbacks,
+                                          const SilcPacketCallbacks *callbacks,
                                           void *callback_context,
                                           int priority, va_list ap)
 {
@@ -1078,7 +1079,7 @@ static SilcBool silc_packet_stream_link_va(SilcPacketStream stream,
 /* Links `callbacks' to `stream' for specified packet types */
 
 SilcBool silc_packet_stream_link(SilcPacketStream stream,
-                                SilcPacketCallbacks *callbacks,
+                                const SilcPacketCallbacks *callbacks,
                                 void *callback_context,
                                 int priority, ...)
 {
@@ -1096,7 +1097,7 @@ SilcBool silc_packet_stream_link(SilcPacketStream stream,
 /* Unlinks `callbacks' from `stream'. */
 
 void silc_packet_stream_unlink(SilcPacketStream stream,
-                              SilcPacketCallbacks *callbacks,
+                              const SilcPacketCallbacks *callbacks,
                               void *callback_context)
 {
   SilcPacketProcess p;
@@ -2339,7 +2340,7 @@ silc_packet_wait_packet_receive(SilcPacketEngine engine,
                                void *stream_context);
 
 /* Packet waiting callbacks */
-static SilcPacketCallbacks silc_packet_wait_cbs =
+static const SilcPacketCallbacks silc_packet_wait_cbs =
 {
   silc_packet_wait_packet_receive, NULL, NULL
 };
@@ -2528,7 +2529,7 @@ typedef struct {
 } *SilcPacketWrapperStream;
 
 /* Packet wrapper callbacks */
-static SilcPacketCallbacks silc_packet_wrap_cbs =
+static const SilcPacketCallbacks silc_packet_wrap_cbs =
 {
   silc_packet_wrap_packet_receive, NULL, NULL
 };