First step in moving core Ethereal routines to libepan.

svn path=/trunk/; revision=2458

1 files changed, 362 insertions, 0 deletions

diff --git a/epan/conversation.c b/epan/conversation.c
new file mode 100644
index 0000000000..144f27b993
--- /dev/null
+++ b/epan/conversation.c
@@ -0,0 +1,362 @@
+/* conversation.c
+ * Routines for building lists of packets that are part of a "conversation"
+ *
+ * $Id: conversation.c,v 1.1 2000/09/27 04:54:47 gram Exp $
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@zing.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * 
+ * 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.
+ * 
+ * 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
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <stdio.h>
+
+#ifdef HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif
+
+#ifdef HAVE_NETINET_IN_H
+# include <netinet/in.h>
+#endif
+
+#include <string.h>
+#include <glib.h>
+#include "packet.h"
+#include "conversation.h"
+
+static GHashTable *conversation_hashtable = NULL;
+static GMemChunk *conversation_key_chunk = NULL;
+static GMemChunk *conversation_chunk = NULL;
+
+typedef struct conversation_key {
+	struct conversation_key *next;
+	address	src;
+	address	dst;
+	port_type ptype;
+	guint32	port_src;
+	guint32	port_dst;
+} conversation_key;
+
+/*
+ * Linked list of conversation keys, so we can, before freeing them all,
+ * free the address data allocations associated with them.
+ */
+static conversation_key *conversation_keys;
+
+static guint32 new_index;
+
+static int conversation_init_count = 200;
+
+/*
+ * Compare two conversation keys.
+ */
+static gint
+conversation_equal(gconstpointer v, gconstpointer w)
+{
+	conversation_key *v1 = (conversation_key *)v;
+	conversation_key *v2 = (conversation_key *)w;
+
+	if (v1->ptype != v2->ptype)
+		return 0;	/* different types of port */
+
+	/*
+	 * Are the first and second source ports the same, the first and
+	 * second destination ports the same, the first and second source
+	 * addresses the same, and the first and second destination
+	 * addresses the same?
+	 */
+	if (v1->port_src == v2->port_src &&
+	    v1->port_dst == v2->port_dst &&
+	    v1->src.type == v2->src.type &&
+	    v1->src.len == v2->src.len &&
+	    memcmp(v1->src.data, v2->src.data, v1->src.len) == 0 &&
+	    v1->dst.type == v2->dst.type &&
+	    v1->dst.len == v2->dst.len &&
+	    memcmp(v1->dst.data, v2->dst.data, v1->dst.len) == 0) {
+		/*
+		 * Yes.  It's the same conversation, and the two
+		 * address/port pairs are going in the same direction.
+		 */
+		return 1;
+	}
+
+	/*
+	 * Is the first source port the same as the second destination
+	 * port, the first destination port the same as the first
+	 * source port, the first source address the same as the second
+	 * destination address, and the first destination address the
+	 * same as the second source address?
+	 */
+	if (v1->port_src == v2->port_dst &&
+	    v1->port_dst == v2->port_src &&
+	    v1->src.type == v2->dst.type &&
+	    v1->src.len == v2->dst.len &&
+	    memcmp(v1->src.data, v2->dst.data, v1->src.len) == 0 &&
+	    v1->dst.type == v2->src.type &&
+	    v1->dst.len == v2->src.len &&
+	    memcmp(v1->dst.data, v2->src.data, v1->dst.len) == 0) {
+		/*
+		 * Yes.  It's the same conversation, and the two
+		 * address/port pairs are going in opposite directions.
+		 */
+		return 1;
+	}
+
+	/*
+	 * The addresses or the ports don't match.
+	 */	
+	return 0;
+}
+
+/*
+ * Compute the hash value for a given set of source and destination
+ * addresses and ports.
+ */
+static guint 
+conversation_hash(gconstpointer v)
+{
+	conversation_key *key = (conversation_key *)v;
+	guint hash_val;
+	int i;
+
+	hash_val = 0;
+	for (i = 0; i < key->src.len; i++)
+		hash_val += key->src.data[i];
+	for (i = 0; i < key->dst.len; i++)
+		hash_val += key->dst.data[i];
+	hash_val += key->port_src + key->port_dst;
+
+	return hash_val;
+}
+
+/*
+ * Initialize some variables every time a file is loaded or re-loaded.
+ * Destroy all existing conversations, and create a new hash table
+ * for the conversations in the new file.
+ */
+void
+conversation_init(void)
+{
+	conversation_key *key;
+
+	/*
+	 * Free the addresses associated with the conversation keys.
+	 */
+	for (key = conversation_keys; key != NULL; key = key->next) {
+		/*
+		 * Grr.  I guess the theory here is that freeing
+		 * something sure as heck modifies it, so you
+		 * want to ban attempts to free it, but, alas,
+		 * if we make the "data" field of an "address"
+		 * structure not a "const", the compiler whines if
+		 * we try to make it point into the data for a packet,
+		 * as that's a "const" array (and should be, as dissectors
+		 * shouldn't trash it).
+		 *
+		 * So we cast the complaint into oblivion, and rely on
+		 * the fact that these addresses are known to have had
+		 * their data mallocated, i.e. they don't point into,
+		 * say, the middle of the data for a packet.
+		 */
+		g_free((gpointer)key->src.data);
+		g_free((gpointer)key->dst.data);
+	}
+	conversation_keys = NULL;
+	if (conversation_hashtable != NULL)
+		g_hash_table_destroy(conversation_hashtable);
+	if (conversation_key_chunk != NULL)
+		g_mem_chunk_destroy(conversation_key_chunk);
+	if (conversation_chunk != NULL)
+		g_mem_chunk_destroy(conversation_chunk);
+
+	conversation_hashtable = g_hash_table_new(conversation_hash,
+	    conversation_equal);
+	conversation_key_chunk = g_mem_chunk_new("conversation_key_chunk",
+	    sizeof(conversation_key),
+	    conversation_init_count * sizeof(struct conversation_key),
+	    G_ALLOC_AND_FREE);
+	conversation_chunk = g_mem_chunk_new("conversation_chunk",
+	    sizeof(conversation_t),
+	    conversation_init_count * sizeof(conversation_t),
+	    G_ALLOC_AND_FREE);
+
+	/*
+	 * Start the conversation indices over at 0.
+	 */
+	new_index = 0;
+}
+
+/*
+ * Copy an address, allocating a new buffer for the address data.
+ */
+static void
+copy_address(address *to, address *from)
+{
+	guint8 *data;
+
+	to->type = from->type;
+	to->len = from->len;
+	data = g_malloc(from->len);
+	memcpy(data, from->data, from->len);
+	to->data = data;
+}
+
+/*
+ * Given source and destination addresses and ports for a packet,
+ * create a new conversation to contain packets between those address/port
+ * pairs.
+ */
+conversation_t *
+conversation_new(address *src, address *dst, port_type ptype,
+    guint32 src_port, guint32 dst_port, void *data)
+{
+	conversation_t *conversation;
+	conversation_key *new_key;
+
+	new_key = g_mem_chunk_alloc(conversation_key_chunk);
+	new_key->next = conversation_keys;
+	conversation_keys = new_key;
+	copy_address(&new_key->src, src);
+	copy_address(&new_key->dst, dst);
+	new_key->ptype = ptype;
+	new_key->port_src = src_port;
+	new_key->port_dst = dst_port;
+
+	conversation = g_mem_chunk_alloc(conversation_chunk);
+	conversation->index = new_index;
+	conversation->data = data;
+
+/* clear dissector pointer */
+	conversation->dissector.new_d = NULL;
+
+	new_index++;
+
+	g_hash_table_insert(conversation_hashtable, new_key, conversation);
+	return conversation;
+}
+
+/*
+ * Given source and destination addresses and ports for a packet,
+ * search for a conversation containing packets between those address/port
+ * pairs.  Returns NULL if not found.
+ */
+conversation_t *
+find_conversation(address *src, address *dst, port_type ptype,
+    guint32 src_port, guint32 dst_port)
+{
+	conversation_key key;
+
+	/*
+	 * We don't make a copy of the address data, we just copy the
+	 * pointer to it, as "key" disappears when we return.
+	 */
+	key.src = *src;
+	key.dst = *dst;
+	key.ptype = ptype;
+	key.port_src = src_port;
+	key.port_dst = dst_port;
+	return g_hash_table_lookup(conversation_hashtable, &key);
+}
+
+/*
+ * Set the dissector for a conversation.
+ */
+void
+old_conversation_set_dissector(conversation_t *conversation,
+    old_dissector_t dissector)
+{
+	conversation->is_old_dissector = TRUE;
+	conversation->dissector.old_d = dissector;
+}
+
+void
+conversation_set_dissector(conversation_t *conversation,
+    dissector_t dissector)
+{
+	conversation->is_old_dissector = FALSE;
+	conversation->dissector.new_d = dissector;
+}
+
+/*
+ * Given source and destination addresses and ports for a packet,
+ * search for a conversational dissector.
+ * If found, call it and return TRUE, otherwise return FALSE.
+ */
+gboolean
+old_try_conversation_dissector(address *src, address *dst, port_type ptype,
+    guint32 src_port, guint32 dst_port, const u_char *pd, int offset,
+    frame_data *fd, proto_tree *tree)
+{
+	conversation_t *conversation;
+	tvbuff_t *tvb;
+
+	conversation = find_conversation(src, dst, ptype, src_port, dst_port);
+	if (conversation != NULL) {
+		if (conversation->is_old_dissector) {
+			if (conversation->dissector.old_d == NULL)
+				return FALSE;
+			(*conversation->dissector.old_d)(pd, offset, fd, tree);
+		} else {
+			if (conversation->dissector.new_d == NULL)
+				return FALSE;
+
+			/*
+			 * Old dissector calling new dissector; use
+			 * "tvb_create_from_top()" to remap.
+			 *
+			 * XXX - what about the "pd" argument?  Do
+			 * any dissectors not just pass that along and
+			 * let the "offset" argument handle stepping
+			 * through the packet?
+			 */
+			tvb = tvb_create_from_top(offset);
+			(*conversation->dissector.new_d)(tvb, &pi, tree);
+		}
+		return TRUE;
+	}
+	return FALSE;
+}
+
+gboolean
+try_conversation_dissector(address *src, address *dst, port_type ptype,
+    guint32 src_port, guint32 dst_port, tvbuff_t *tvb, packet_info *pinfo,
+    proto_tree *tree)
+{
+	conversation_t *conversation;
+	const guint8 *pd;
+	int offset;
+
+	conversation = find_conversation(src, dst, ptype, src_port, dst_port);
+	if (conversation != NULL) {
+		if (conversation->is_old_dissector) {
+			/*
+			 * New dissector calling old dissector; use
+			 * "tvb_compat()" to remap.
+			 */
+			tvb_compat(tvb, &pd, &offset);
+			(*conversation->dissector.old_d)(pd, offset, pinfo->fd,
+			    tree);
+		} else
+			(*conversation->dissector.new_d)(tvb, pinfo, tree);
+		return TRUE;
+	}
+	return FALSE;
+}