Add small dissector for application/x-www-form-urlencoded

svn path=/trunk/; revision=49977

1 files changed, 219 insertions, 0 deletions

diff --git a/epan/dissectors/packet-http-urlencoded.c b/epan/dissectors/packet-http-urlencoded.c
new file mode 100644
index 0000000000..333f3677b1
--- /dev/null
+++ b/epan/dissectors/packet-http-urlencoded.c
@@ -0,0 +1,219 @@
+/* packet-http-urlencoded.c
+ * Routines for dissection of HTTP urlecncoded form, based on packet-text-media.c (C) Olivier Biot, 2004.
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+
+#include <glib.h>
+
+#include <epan/packet.h>
+#include <epan/strutil.h>
+
+static gint proto_urlencoded = -1;
+
+static gint hf_form_keyvalue = -1;
+static gint hf_form_key = -1;
+static gint hf_form_value = -1;
+
+static gint ett_form_urlencoded = -1;
+static gint ett_form_keyvalue = -1;
+
+static guint8
+get_hexa(guint8 a)
+{
+	if (a >= '0' && a <= '9')
+		return a - '0';
+	if (a >= 'A' && a <= 'F')
+		return (a - 'A') + 10;
+	if (a >= 'a' && a <= 'f')
+		return (a - 'a') + 10;
+
+	return 0xff;
+}
+
+static int
+get_form_key_value(tvbuff_t *tvb, char **ptr, int offset, char stop)
+{
+	const int orig_offset = offset;
+	char *tmp;
+	int len;
+
+	len = 0;
+	while (tvb_reported_length_remaining(tvb, offset) > 0) {
+		guint8 ch;
+
+		ch = tvb_get_guint8(tvb, offset);
+		if (!ch)
+			return -1;
+		if (ch == stop)
+			break;
+		if (ch == '%') {
+			offset++;
+			ch = tvb_get_guint8(tvb, offset);
+			if (get_hexa(ch) > 15)
+				return -1;
+
+			offset++;
+			ch = tvb_get_guint8(tvb, offset);
+			if (get_hexa(ch) > 15)
+				return -1;
+		}
+
+		len++;
+		offset++;
+	}
+
+	*ptr = tmp = ep_alloc(len + 1);
+	tmp[len] = '\0';
+
+	len = 0;
+	offset = orig_offset;
+	while (tvb_reported_length_remaining(tvb, offset) > 0) {
+		guint8 ch;
+
+		ch = tvb_get_guint8(tvb, offset);
+		if (!ch)
+			return -1;
+		if (ch == stop)
+			break;
+
+		if (ch == '%') {
+			guint8 ch1, ch2;
+			
+			offset++;
+			ch1 = tvb_get_guint8(tvb, offset);
+
+			offset++;
+			ch2 = tvb_get_guint8(tvb, offset);
+
+			tmp[len] = get_hexa(ch1) << 4 | get_hexa(ch2);
+
+		} else if (ch == '+')
+			tmp[len] = ' ';
+		else 
+			tmp[len] = ch;
+
+		len++;
+		offset++;
+	}
+
+	return offset;
+}
+
+
+static void
+dissect_form_urlencoded(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	proto_tree	*url_tree;
+	proto_tree	*sub;
+	proto_item	*ti;
+	gint		offset = 0, next_offset;
+	const char	*data_name;
+
+	data_name = pinfo->match_string;
+	if (! (data_name && data_name[0])) {
+		/*
+		 * No information from "match_string"
+		 */
+		data_name = (char *)(pinfo->private_data);
+		if (! (data_name && data_name[0])) {
+			/*
+			 * No information from "private_data"
+			 */
+			data_name = NULL;
+		}
+	}
+
+	if (data_name)
+		col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "(%s)", data_name);
+
+	ti = proto_tree_add_item(tree, proto_urlencoded, tvb, 0, -1, ENC_NA);
+	if (data_name)
+		proto_item_append_text(ti, ": %s", data_name);
+	url_tree = proto_item_add_subtree(ti, ett_form_urlencoded);
+
+	while (tvb_reported_length_remaining(tvb, offset) > 0) {
+		const int start_offset = offset;
+		char *key, *value;
+
+		ti = proto_tree_add_item(url_tree, hf_form_keyvalue, tvb, offset, 0, ENC_NA);
+
+		sub = proto_item_add_subtree(ti, ett_form_urlencoded);
+
+		next_offset = get_form_key_value(tvb, &key, offset, '=');
+		proto_tree_add_string(sub, hf_form_key, tvb, offset, next_offset - offset, key);
+		if (next_offset == -1)
+			break;
+		proto_item_append_text(sub, ": \"%s\"", key);
+
+		offset = next_offset+1;
+
+		next_offset = get_form_key_value(tvb, &value, offset, '&');
+		proto_tree_add_string(sub, hf_form_value, tvb, offset, next_offset - offset, value);
+		if (next_offset == -1)
+			break;
+		proto_item_append_text(sub, " = \"%s\"", value);
+
+		offset = next_offset+1;
+
+		proto_item_set_len(ti, offset - start_offset);
+	}
+}
+
+void
+proto_register_http_urlencoded(void)
+{
+	static hf_register_info hf[] = {
+		{ &hf_form_keyvalue,
+			{ "Form item", "urlencoded-form", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }
+		},
+		{ &hf_form_key,
+			{ "Key", "urlencoded-form.key", FT_STRINGZ, BASE_NONE, NULL, 0x0, NULL, HFILL }
+		},
+		{ &hf_form_value,
+			{ "Value", "urlencoded-form.value", FT_STRINGZ, BASE_NONE, NULL, 0x0, NULL, HFILL }
+		},
+	};
+
+	static gint *ett[] = {
+		&ett_form_urlencoded,
+		&ett_form_keyvalue
+	};
+
+
+	proto_urlencoded = proto_register_protocol("HTML Form URL Encoded", "URL Encoded Form Data", "urlencoded-form");
+	register_dissector("urlencoded-form", dissect_form_urlencoded, proto_urlencoded);
+
+	proto_register_field_array(proto_urlencoded, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+}
+
+void
+proto_reg_handoff_http_urlencoded(void)
+{
+	dissector_handle_t form_urlencoded_handle;
+
+	form_urlencoded_handle = find_dissector("urlencoded-form");
+
+	dissector_add_string("media_type", "application/x-www-form-urlencoded", form_urlencoded_handle);
+}