From Jakub Zawadzki via bug 4753: New dissector: JSON, w/minor changes by me:

1) Add links to RFC 4627 and the json.org web site.
2) Comment out hf_json_member_key to keep tools/checkhf.pl happy.
3) Avoid duplicate (application/json) from being displayed in Info column.

svn path=/trunk/; revision=35317

1 files changed, 441 insertions, 0 deletions

diff --git a/epan/dissectors/packet-json.c b/epan/dissectors/packet-json.c
new file mode 100755
index 0000000000..d0c856f880
--- /dev/null
+++ b/epan/dissectors/packet-json.c
@@ -0,0 +1,441 @@
+/* packet-json.c
+ * Routines for JSON dissection
+ * References:
+ *     RFC 4627: http://tools.ietf.org/html/rfc4627
+ *     Website:  http://json.org/
+ *
+ * Copyright 2010, Jakub Zawadzki <darkjames@darkjames.ath.cx>
+ *
+ * $Id$
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <glib.h>
+
+#include <epan/emem.h>
+#include <epan/packet.h>
+#include <epan/tvbparse.h>
+
+static gint proto_json = -1;
+
+static gint ett_json = -1;
+static gint ett_json_array = -1;
+static gint ett_json_object = -1;
+static gint ett_json_member = -1;
+
+static gint hf_json_array = -1;
+static gint hf_json_object = -1;
+static gint hf_json_member = -1;
+/* XXX, static gint hf_json_member_key = -1; */
+
+static gint hf_json_value_string = -1;
+static gint hf_json_value_number = -1;
+static gint hf_json_value_false = -1;
+static gint hf_json_value_null = -1;
+static gint hf_json_value_true = -1;
+
+static tvbparse_wanted_t* want;
+static tvbparse_wanted_t* want_ignore;
+
+static dissector_handle_t text_lines_handle;
+
+typedef enum {
+	JSON_TOKEN_INVALID = -1,
+	JSON_TOKEN_NUMBER = 0,
+	JSON_TOKEN_STRING,
+	JSON_TOKEN_FALSE,
+	JSON_TOKEN_NULL,
+	JSON_TOKEN_TRUE,
+
+	/* not really tokens ... */
+	JSON_OBJECT,
+	JSON_ARRAY
+
+} json_token_type_t;
+
+typedef struct {
+	ep_stack_t stack;
+
+} json_parser_data_t;
+
+static void
+dissect_json(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	proto_tree *json_tree = NULL;
+	proto_item *ti = NULL;
+
+	json_parser_data_t parser_data;
+	tvbparse_t *tt;
+
+	const char *data_name;
+	int offset;
+
+	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 (tree) {
+		ti = proto_tree_add_item(tree, proto_json, tvb, 0, -1, FALSE);
+		json_tree = proto_item_add_subtree(ti, ett_json);
+
+		if (data_name)
+			proto_item_append_text(ti, ": %s", data_name);
+	}
+
+	offset = 0;
+	
+	parser_data.stack = ep_stack_new();
+	ep_stack_push(parser_data.stack, json_tree);
+
+	tt = tvbparse_init(tvb, offset, -1, &parser_data, want_ignore);
+
+	/* XXX, only one json in packet? */
+	while ((tvbparse_get(tt, want)))
+		;
+
+	offset = tvbparse_curr_offset(tt);
+
+	proto_item_set_len(ti, offset);
+
+	/* if we have some unparsed data, pass to data-text-lines dissector (?) */
+	if (tvb_length_remaining(tvb, offset) != 0) {
+		int datalen, reported_datalen;
+		tvbuff_t *next_tvb;
+		
+		datalen = tvb_length_remaining(tvb, offset);
+		reported_datalen = tvb_reported_length_remaining(tvb, offset);
+
+		next_tvb = tvb_new_subset(tvb, offset, datalen, reported_datalen);
+
+		call_dissector(text_lines_handle, next_tvb, pinfo, tree);
+	} else if (data_name) {
+		col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "(%s)", data_name);
+	}
+}
+
+static void before_object(void *tvbparse_data, const void *wanted_data _U_, tvbparse_elem_t *tok) {
+	json_parser_data_t *data = (json_parser_data_t *) tvbparse_data;
+
+	proto_tree *tree = ep_stack_peek(data->stack);
+	proto_tree *subtree;
+	proto_item *ti;
+
+	ti = proto_tree_add_item(tree, hf_json_object, tok->tvb, tok->offset, tok->len, FALSE);
+
+	subtree = proto_item_add_subtree(ti, ett_json_object);
+	ep_stack_push(data->stack, subtree);
+}
+
+static void after_object(void *tvbparse_data, const void *wanted_data _U_, tvbparse_elem_t *elem _U_) {
+	json_parser_data_t *data = (json_parser_data_t *) tvbparse_data;
+
+	ep_stack_pop(data->stack);
+}
+
+static void before_member(void *tvbparse_data, const void *wanted_data _U_, tvbparse_elem_t *tok) {
+	json_parser_data_t *data = (json_parser_data_t *) tvbparse_data;
+
+	proto_tree *tree = ep_stack_peek(data->stack);
+	proto_tree *subtree;
+	proto_item *ti;
+
+	ti = proto_tree_add_item(tree, hf_json_member, tok->tvb, tok->offset, tok->len, FALSE);
+
+	subtree = proto_item_add_subtree(ti, ett_json_member);
+	ep_stack_push(data->stack, subtree);
+}
+
+static void after_member(void *tvbparse_data, const void *wanted_data _U_, tvbparse_elem_t *tok) {
+	json_parser_data_t *data = (json_parser_data_t *) tvbparse_data;
+
+	proto_tree *tree = ep_stack_pop(data->stack);
+
+	if (tree) {
+		tvbparse_elem_t *key_tok = tok->sub;
+
+		if (key_tok && key_tok->id == JSON_TOKEN_STRING) {
+			char *key = tvb_get_ephemeral_string(key_tok->tvb, key_tok->offset, key_tok->len);
+
+			proto_item_append_text(tree, " Key: %s", key);
+		}
+		/* XXX, hf_json_member_key */
+	}
+}
+
+static void before_array(void *tvbparse_data, const void *wanted_data _U_, tvbparse_elem_t *tok) {
+	json_parser_data_t *data = (json_parser_data_t *) tvbparse_data;
+
+	proto_tree *tree = ep_stack_peek(data->stack);
+	proto_tree *subtree;
+	proto_item *ti;
+
+	ti = proto_tree_add_item(tree, hf_json_array, tok->tvb, tok->offset, tok->len, FALSE);
+
+	subtree = proto_item_add_subtree(ti, ett_json_array);
+	ep_stack_push(data->stack, subtree);
+}
+
+static void after_array(void *tvbparse_data, const void *wanted_data _U_, tvbparse_elem_t *elem _U_) {
+	json_parser_data_t *data = (json_parser_data_t *) tvbparse_data;
+
+	ep_stack_pop(data->stack);
+}
+
+static void after_value(void *tvbparse_data, const void *wanted_data _U_, tvbparse_elem_t *tok) {
+	json_parser_data_t *data = (json_parser_data_t *) tvbparse_data;
+
+	proto_tree *tree = ep_stack_peek(data->stack);
+	json_token_type_t value_id = JSON_TOKEN_INVALID;
+
+	if (tok->sub)
+		value_id = tok->sub->id;
+
+	switch (value_id) {
+		case JSON_TOKEN_STRING:
+			if (tok->len >= 2) {
+				char *str = ep_alloc(tok->len - 1);
+
+				/* XXX, for now only strip quotes, later we can unescape string */
+				tvb_memcpy(tok->tvb, str, tok->offset + 1, tok->len - 2);
+				str[tok->len - 2] = '\0';
+				proto_tree_add_string(tree, hf_json_value_string, tok->tvb, tok->offset, tok->len, str);
+			} else
+				proto_tree_add_item(tree, hf_json_value_string, tok->tvb, tok->offset, tok->len, FALSE);
+			break;
+
+		case JSON_TOKEN_NUMBER:
+			/* XXX, convert to number */
+			proto_tree_add_item(tree, hf_json_value_number, tok->tvb, tok->offset, tok->len, FALSE);
+			break;
+
+		case JSON_TOKEN_FALSE:
+			proto_tree_add_item(tree, hf_json_value_false, tok->tvb, tok->offset, tok->len, FALSE);
+			break;
+
+		case JSON_TOKEN_NULL:
+			proto_tree_add_item(tree, hf_json_value_null, tok->tvb, tok->offset, tok->len, FALSE);
+			break;
+
+		case JSON_TOKEN_TRUE:
+			proto_tree_add_item(tree, hf_json_value_true, tok->tvb, tok->offset, tok->len, FALSE);
+			break;
+
+		case JSON_OBJECT:
+		case JSON_ARRAY:
+			/* already added */
+			break;
+
+		default:
+			proto_tree_add_text(tree, tok->tvb, tok->offset, tok->len, "%s", tvb_format_text(tok->tvb, tok->offset, tok->len));
+			break;
+	}
+}
+
+static void init_json_parser(void) {
+	static tvbparse_wanted_t _want_object;
+	static tvbparse_wanted_t _want_array;
+
+	tvbparse_wanted_t *want_object, *want_array;
+	tvbparse_wanted_t *want_member;
+	tvbparse_wanted_t *want_string;
+	tvbparse_wanted_t *want_number, *want_int;
+	tvbparse_wanted_t *want_value;
+	tvbparse_wanted_t *want_value_separator;
+
+#define tvbparse_optional(id, private_data, before_cb, after_cb, wanted) \
+	tvbparse_some(id, 0, 1, private_data, before_cb, after_cb, wanted)
+
+	want_string = tvbparse_quoted(JSON_TOKEN_STRING, NULL, NULL, NULL, '\"', '\\');
+
+	want_value_separator = tvbparse_char(-1, ",", NULL, NULL, NULL);
+
+	/* int = zero / ( digit1-9 *DIGIT ) */
+	want_int = tvbparse_set_oneof(-1, NULL, NULL, NULL,
+			tvbparse_char(-1, "0", NULL, NULL, NULL),
+			tvbparse_set_seq(-1, NULL, NULL, NULL,
+				tvbparse_chars(-1, 1, 1, "123456789", NULL, NULL, NULL),
+				tvbparse_optional(-1, NULL, NULL, NULL, /* tvbparse_chars() don't respect 0 as min_len ;/ */
+					tvbparse_chars(-1, 0, 0, "0123456789", NULL, NULL, NULL)),
+				NULL),
+			NULL);
+
+	/* number = [ minus ] int [ frac ] [ exp ] */
+	want_number = tvbparse_set_seq(JSON_TOKEN_NUMBER, NULL, NULL, NULL,
+			tvbparse_optional(-1, NULL, NULL, NULL, /* tvbparse_chars() don't respect 0 as min_len ;/ */
+				tvbparse_chars(-1, 0, 1, "-", NULL, NULL, NULL)),
+			want_int,
+			/* frac = decimal-point 1*DIGIT */
+			tvbparse_optional(-1, NULL, NULL, NULL,
+				tvbparse_set_seq(-1, NULL, NULL, NULL,
+					tvbparse_char(-1, ".", NULL, NULL, NULL),
+					tvbparse_chars(-1, 1, 0, "0123456789", NULL, NULL, NULL),
+					NULL)),
+			/* exp = e [ minus / plus ] 1*DIGIT */
+			tvbparse_optional(-1, NULL, NULL, NULL,
+				tvbparse_set_seq(-1, NULL, NULL, NULL,
+					tvbparse_char(-1, "eE", NULL, NULL, NULL),
+					tvbparse_optional(-1, NULL, NULL, NULL, /* tvbparse_chars() don't respect 0 as min_len ;/ */
+						tvbparse_chars(-1, 0, 1, "-+", NULL, NULL, NULL)),
+					tvbparse_chars(-1, 1, 0, "0123456789", NULL, NULL, NULL),
+					NULL)),
+			NULL);
+
+	/* value = false / null / true / object / array / number / string */
+	want_value = tvbparse_set_oneof(-1, NULL, NULL, after_value,
+			tvbparse_string(JSON_TOKEN_FALSE, "false", NULL, NULL, NULL),
+			tvbparse_string(JSON_TOKEN_NULL, "null", NULL, NULL, NULL),
+			tvbparse_string(JSON_TOKEN_TRUE, "true", NULL, NULL, NULL),
+			&_want_object,
+			&_want_array,
+			want_number,
+			want_string,
+			NULL);
+
+	/* array = begin-array [ value *( value-separator value ) ] end-array */
+	want_array = tvbparse_set_seq(JSON_ARRAY, NULL, before_array, after_array,
+			tvbparse_char(-1, "[", NULL, NULL, NULL),
+			tvbparse_optional(-1, NULL, NULL, NULL,
+				tvbparse_set_seq(-1, NULL, NULL, NULL,
+					want_value,
+					tvbparse_some(-1, 0, G_MAXINT, NULL, NULL, NULL, 
+						tvbparse_set_seq(-1, NULL, NULL, NULL,
+							want_value_separator,
+							want_value,
+							NULL)),
+					NULL)
+				),
+			tvbparse_char(-1, "]", NULL, NULL, NULL),
+			NULL);
+	_want_array = *want_array;
+
+	/* member = string name-separator value */
+	want_member = tvbparse_set_seq(-1, NULL, before_member, after_member,
+			want_string,
+			tvbparse_char(-1, ":", NULL, NULL, NULL),
+			want_value,
+			NULL);
+
+	/* object = begin-object [ member *( value-separator member ) ] end-object */
+	want_object = tvbparse_set_seq(JSON_OBJECT, NULL, before_object, after_object,
+			tvbparse_char(-1, "{", NULL, NULL, NULL),
+			tvbparse_optional(-1, NULL, NULL, NULL,
+				tvbparse_set_seq(-1, NULL, NULL, NULL,
+					want_member,
+					tvbparse_some(-1, 0, G_MAXINT, NULL, NULL, NULL, 
+						tvbparse_set_seq(-1, NULL, NULL, NULL,
+							want_value_separator,
+							want_member,
+							NULL)),
+					NULL)
+				),
+			tvbparse_char(-1, "}", NULL, NULL, NULL),
+			NULL);
+	_want_object = *want_object;
+
+	want_ignore = tvbparse_chars(-1, 1, 0, " \t\r\n", NULL, NULL, NULL);
+
+	/* JSON-text = object / array */
+	want = tvbparse_set_oneof(-1, NULL, NULL, NULL,
+		want_object,
+		want_array,
+		/* tvbparse_not_chars(-1, 1, 0, " \t\r\n", NULL, NULL, NULL), */
+		NULL);
+
+	/* XXX, heur? */
+}
+
+void
+proto_register_json(void) {
+	static gint *ett[] = {
+		&ett_json,
+		&ett_json_array,
+		&ett_json_object,
+		&ett_json_member
+	};
+
+	static hf_register_info hf[] = {
+		{ &hf_json_array,
+			{ "Array", "json.array", FT_NONE, BASE_NONE, NULL, 0x00, "JSON array", HFILL }
+		}, 
+		{ &hf_json_object,
+			{ "Object", "json.object", FT_NONE, BASE_NONE, NULL, 0x00, "JSON object", HFILL }
+		}, 
+		{ &hf_json_member,
+			{ "Member", "json.member", FT_NONE, BASE_NONE, NULL, 0x00, "JSON object member", HFILL },
+		},
+/* XXX
+		{ &hf_json_member_key,
+			{ "Key", "json.member.key", FT_NONE, BASE_NONE, NULL, 0x00, NULL, HFILL },
+		},
+*/
+		{ &hf_json_value_string, /* FT_STRINGZ? */
+			{ "String value", "json.value.string", FT_STRING, BASE_NONE, NULL, 0x00, "JSON string value", HFILL },
+		},
+		{ &hf_json_value_number, /* FT_DOUBLE/ FT_INT64? */
+			{ "Number value", "json.value.number", FT_STRING, BASE_NONE, NULL, 0x00, "JSON number value", HFILL },
+		},
+		{ &hf_json_value_false,
+			{ "False value", "json.value.false", FT_NONE, BASE_NONE, NULL, 0x00, "JSON false value", HFILL },
+		},
+		{ &hf_json_value_null,
+			{ "Null value", "json.value.null", FT_NONE, BASE_NONE, NULL, 0x00, "JSON null value", HFILL },
+		},
+		{ &hf_json_value_true,
+			{ "True value", "json.value.true", FT_NONE, BASE_NONE, NULL, 0x00, "JSON true value", HFILL },
+		},
+
+	};
+
+	proto_json = proto_register_protocol("JavaScript Object Notation", "JSON", "json");
+
+	proto_register_field_array(proto_json, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+
+	register_dissector("json", dissect_json, proto_json);
+
+	init_json_parser();
+}
+
+void
+proto_reg_handoff_json(void)
+{
+	dissector_handle_t json_handle;
+
+	json_handle = find_dissector("json");
+
+	dissector_add_string("media_type", "application/json", json_handle); /* RFC 4627 */
+
+	text_lines_handle = find_dissector("data-text-lines");
+}
+