[Spice-devel] [PATCH v5 05/41] dissector: Generate skeleton for messages and channels

Frediano Ziglio fziglio at redhat.com
Fri Aug 7 08:00:34 PDT 2015


Messages are not generated as stub.
Code partially from demarshaller.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 codegen/Makefile.am         |   3 +-
 codegen/check_dissector     |  13 +++++
 codegen/dissector_test.c    |  54 ++++++++++++++++-
 python_modules/dissector.py | 138 +++++++++++++++++++++++++++++++++++++++++++-
 4 files changed, 203 insertions(+), 5 deletions(-)
 create mode 100755 codegen/check_dissector

diff --git a/codegen/Makefile.am b/codegen/Makefile.am
index e959783..eaa0d59 100644
--- a/codegen/Makefile.am
+++ b/codegen/Makefile.am
@@ -30,13 +30,14 @@ test.c: $(top_srcdir)/spice.proto $(MARSHALLERS_DEPS)
 test.h: $(top_srcdir)/spice.proto $(MARSHALLERS_DEPS)
 	$(AM_V_GEN)$(PYTHON) $(top_srcdir)/spice_codegen.py --generate-dissector --client $< --header $@ >/dev/null
 
-TESTS = dissector_test
+TESTS = check_dissector
 check_PROGRAMS = dissector_test
 
 dissector_test_SOURCES = dissector_test.c test.c test.h
 endif
 
 EXTRA_DIST =				\
+	check_dissector			\
 	$(NULL)
 
 -include $(top_srcdir)/git.mk
diff --git a/codegen/check_dissector b/codegen/check_dissector
new file mode 100755
index 0000000..f1444a2
--- /dev/null
+++ b/codegen/check_dissector
@@ -0,0 +1,13 @@
+#!/bin/bash
+set -e
+
+error() {
+	echo "$*" >&2
+	exit 1
+}
+
+./dissector_test 1 100
+if ./dissector_test 1 99; then
+	error "This test should fail"
+fi
+exit 0
diff --git a/codegen/dissector_test.c b/codegen/dissector_test.c
index 3212655..25a33b5 100644
--- a/codegen/dissector_test.c
+++ b/codegen/dissector_test.c
@@ -4,6 +4,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <getopt.h>
+#include <stdbool.h>
 #include <assert.h>
 
 #include <epan/expert.h>
@@ -18,6 +19,7 @@ enum {
 static int last_hf_registered = first_hf_registered - 1;
 static int last_ei_registered = first_ei_registered - 1;
 static int last_tree_registered = first_tree_registered - 1;
+static bool got_error = false;
 
 WS_DLL_PUBLIC void
 proto_register_field_array(const int parent, hf_register_info *hf, const int num_records)
@@ -54,24 +56,46 @@ expert_register_field_array(expert_module_t* module, ei_register_info *ei, const
 	}
 }
 
+WS_DLL_PUBLIC void
+expert_add_info_format(packet_info *pinfo, proto_item *pi, expert_field *eiindex,
+	const char *format, ...)
+{
+	assert(format);
+	got_error = true;
+	if (!pi)
+		return;
+}
+
 static const struct option long_options[] = {
 	{ "help", 0, NULL, 'h' },
+	{ "server", 0, NULL, 's' },
+	{ "client", 0, NULL, 'c' },
 };
-static const char options[] = "h";
+static const char options[] = "hsc";
 
 static void syntax(FILE *f, int exit_value)
 {
 	fprintf(f,
-		"Usage: dissector_test [OPTIONS]\n"
+		"Usage: dissector_test [OPTIONS] CHANNEL MESSAGE_TYPE\n"
 		"\n"
 		"Options:\n"
 		"  -h, --help               Show this help\n"
+		"  -s, --server             Process server messages (default)\n"
+		"  -c, --client             Process client messages\n"
 	);
 	exit(exit_value);
 }
 
 int main(int argc, char **argv)
 {
+	int channel, message_type;
+	GlobalInfo glb;
+	proto_tree tree;
+	spice_dissect_func_t (*msg_func)(guint8 channel);
+	spice_dissect_func_t channel_func = NULL;
+
+	msg_func = spice_server_channel_get_dissect;
+
 	while (1) {
 		int option_index;
 		int opt = getopt_long(argc, argv, options, long_options, &option_index);
@@ -82,13 +106,37 @@ int main(int argc, char **argv)
 		case 'h':
 			syntax(stdout, EXIT_SUCCESS);
 			break;
+		case 's':
+			msg_func = spice_server_channel_get_dissect;
+			break;
+		case 'c':
+			msg_func = spice_client_channel_get_dissect;
+			break;
 		default:
 			syntax(stderr, EXIT_FAILURE);
 			break;
 		}
 	}
+	if (optind + 2 > argc)
+		syntax(stderr, EXIT_FAILURE);
+
+	channel      = strtol(argv[optind++], NULL, 0);
+	message_type = strtol(argv[optind++], NULL, 0);
 
 	spice_register_fields(1, NULL);
 
-	return EXIT_SUCCESS;
+	memset(&glb, 0, sizeof(glb));
+	glb.tvb = NULL;
+	glb.message_offset = 0;
+	glb.message_end = 0;
+
+	channel_func = msg_func(channel);
+	assert(channel_func);
+
+	memset(&tree, 0, sizeof(tree));
+
+	/* TODO check offset ?? */
+	channel_func(message_type, &glb, &tree, 0);
+
+	return got_error ? EXIT_FAILURE : EXIT_SUCCESS;
 }
diff --git a/python_modules/dissector.py b/python_modules/dissector.py
index e088cb6..b93b9ce 100644
--- a/python_modules/dissector.py
+++ b/python_modules/dissector.py
@@ -1,4 +1,5 @@
 
+from . import ptypes
 from . import codegen
 import re
 
@@ -66,6 +67,124 @@ def write_parser_helpers(writer):
     writer.writeln('#endif')
     writer.newline()
 
+def write_msg_parser(writer, message, server):
+    msg_name = message.c_name()
+    function_name = "dissect_spice_%s_%s" % ('server' if server else 'client', msg_name)
+    if writer.is_generated("msg_parser", function_name):
+        return function_name
+    writer.set_is_generated("msg_parser", function_name)
+
+    msg_type = message.c_type()
+    msg_sizeof = message.sizeof()
+
+    writer.newline()
+    writer.ifdef(message)
+    parent_scope = writer.function(function_name,
+                                   "guint32",
+                                   "GlobalInfo *glb _U_, proto_tree *tree0 _U_, guint32 offset", True)
+
+    writer.statement("return offset")
+    writer.end_block()
+
+    writer.endif(message)
+
+    return function_name
+
+def write_channel_parser(writer, channel, server):
+    writer.newline()
+    ids = {}
+    if server:
+        messages = channel.server_messages
+    else:
+        messages = channel.client_messages
+    for m in messages:
+        ids[m.value] = m
+
+    ranges = []
+    ids2 = ids.copy()
+    while len(ids2) > 0:
+        end = start = min(ids2.keys())
+        while end in ids2:
+            del ids2[end]
+            end = end + 1
+
+        ranges.append( (start, end) )
+
+    if server:
+        function_name = "dissect_spice_data_server_%s" % channel.name
+    else:
+        function_name = "dissect_spice_data_client_%s" % channel.name
+    writer.newline()
+    writer.ifdef(channel)
+    scope = writer.function(function_name,
+                            "guint32",
+                            "guint16 message_type, GlobalInfo *glb _U_, proto_tree *tree _U_, guint32 offset", True)
+
+    helpers = writer.function_helper()
+
+    d = 0
+    for r in ranges:
+        d = d + 1
+        writer.write("static const parse_msg_func_t funcs%d[%d] = " % (d, r[1] - r[0]))
+        writer.begin_block()
+        for i in range(r[0], r[1]):
+            func = write_msg_parser(helpers, ids[i].message_type, server)
+            writer.write(func)
+            if i != r[1] -1:
+                writer.write(",")
+            writer.newline()
+
+        writer.end_block(semicolon = True)
+
+    d = 0
+    for r in ranges:
+        d = d + 1
+        with writer.if_block("message_type >= %d && message_type < %d" % (r[0], r[1]), d > 1, False):
+            writer.statement("return funcs%d[message_type-%d](glb, tree, offset)" % (d, r[0]))
+    writer.newline()
+
+    writer.statement('expert_add_info_format(glb->pinfo, glb->msgtype_item, &ei_spice_unknown_message, "Unknown display server message - cannot dissect")')
+    writer.statement("return offset")
+    writer.end_block()
+    writer.endif(channel)
+
+    return function_name
+
+def write_get_channel_parser(writer, channel_parsers, max_channel, is_server):
+    writer.newline()
+    function_name = "spice_%s%s_channel_get_dissect" % ('server' if is_server else 'client', writer.public_prefix)
+
+    writer.function(function_name, "spice_dissect_func_t", "guint8 channel")
+
+    writer.write("static const spice_dissect_func_t channels[%d] = " % (max_channel+1))
+    writer.begin_block()
+    channel = None
+    for i in range(0, max_channel + 1):
+        if i in channel_parsers:
+            channel = channel_parsers[i][0]
+            writer.ifdef(channel)
+            writer.write(channel_parsers[i][1])
+        else:
+            writer.write("NULL")
+
+        if i != max_channel:
+            writer.write(",")
+        writer.newline()
+        if channel and channel.has_attr("ifdef"):
+            writer.ifdef_else(channel)
+            writer.write("NULL")
+            if i != max_channel:
+                writer.write(",")
+            writer.newline()
+            writer.endif(channel)
+    writer.end_block(semicolon = True)
+
+    with writer.if_block("channel < %d" % (max_channel + 1)):
+        writer.statement("return channels[channel]")
+
+    writer.statement("return NULL")
+    writer.end_block()
+
 
 def write_protocol_definitions(writer):
     global hf_defs
@@ -128,8 +247,25 @@ def write_protocol_parser(writer, proto):
         writer.newline()
     hf_writer = writer.get_subwriter()
 
+    # put everything else after
+    defs_writer = writer
+    writer = writer.get_subwriter()
+
     # put fields definition at last
-    write_protocol_definitions(writer)
+    write_protocol_definitions(defs_writer)
+
+    # scan all, looks for items and tree
+    # list add items and tree
+    # write all structure functions (get size + tree)
+    for is_server in (True, False):
+        max_channel = 0
+        parsers = {}
+        for channel in proto.channels:
+            max_channel = max(max_channel, channel.value)
+
+            parsers[channel.value] = (channel.channel_type, write_channel_parser(writer, channel.channel_type, is_server))
+
+        write_get_channel_parser(writer, parsers, max_channel, is_server)
 
 def write_includes(writer, dest_file):
     header_name = re.sub(r'\.(c|cpp|cc|cxx|C)$', '.h', dest_file)
-- 
2.1.0



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