Move the next message helper into a shared function

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

meson.build

@@ -34,6 +34,8 @@ lib_util = static_library('util',
 dep_libutil = declare_dependency(link_with: lib_util)
 
 src_libei = [
+    'src/brei-shared.h',
+    'src/brei-shared.c',
     'src/libei.h',
     'src/libei.c',
     'src/libei-device.c',
@@ -63,6 +65,8 @@ pkgconfig.generate(lib_libei,
 )
 
 lib_libeis = shared_library('eis',
+    'src/brei-shared.h',
+    'src/brei-shared.c',
     'src/libeis.h',
     'src/libeis.c',
     'src/libeis-client.c',

src/brei-shared.c

@@ -0,0 +1,122 @@
+/*
+ * Copyright © 2020 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "config.h"
+
+#include "util-mem.h"
+
+#include "proto/ei.pb-c.h"
+#include "brei-shared.h"
+
+
+static void frame_cleanup(Frame **f) {
+	if (*f)
+		frame__free_unpacked(*f, NULL);
+}
+#define _cleanup_frame_ _cleanup_(frame_cleanup)
+
+const unsigned char *
+brei_next_message(const char *data, size_t *msglen, size_t *consumed)
+{
+	/* Every message is prefixed by a fixed-length Frame message which
+	 * contains the length of the next message. Frames are always the
+	 * same length, so we only need to calculate the size once.
+	 */
+	static size_t framelen = 0;
+
+	if (framelen == 0) {
+		Frame f = FRAME__INIT;
+		f.length = 0xffff;
+		framelen = frame__get_packed_size(&f);
+		assert(framelen >= 5);
+	}
+
+	_cleanup_frame_ Frame *frame = frame__unpack(NULL, framelen, (const unsigned char *)data);
+	if (!frame)
+		return NULL;
+
+	*msglen = frame->length;
+	*consumed = framelen;
+
+	return (const unsigned char*)data + framelen;
+}
+
+
+#ifdef _enable_tests_
+#include <munit.h>
+
+static MunitResult
+test_proto_next_message(const MunitParameter params[], void *user_data)
+{
+	char data[64];
+
+	/* Invalid frame, rest can be random */
+	data[0] = 0xaa;
+
+	size_t msglen = 0xab;
+	size_t consumed = 0xbc;
+
+	const unsigned char *rval = brei_next_message(data, &msglen, &consumed);
+	munit_assert_ptr_null(rval);
+	munit_assert_int(msglen, ==, 0xab);
+	munit_assert_int(consumed, ==, 0xbc);
+
+	/* Now try a valid one */
+	Frame f = FRAME__INIT;
+	f.length = 0xcd;
+	size_t framelen = frame__get_packed_size(&f);
+
+	unsigned char buf[framelen * 4];
+	for (int i = 0; i < 4; i++)
+		frame__pack(&f, buf + framelen * i);
+
+	const char *ptr = (char*)buf;
+	for (int i = 0; i < 4; i++) {
+		const unsigned char *next_frame = brei_next_message(ptr, &msglen, &consumed);
+		munit_assert_ptr_equal(next_frame, buf + (i + 1) * framelen);
+		munit_assert_int(consumed, ==, framelen);
+		munit_assert_int(msglen, ==, 0xcd);
+		ptr += consumed;
+	}
+
+	return MUNIT_OK;
+}
+
+#define TEST(_func) \
+	{ .name = #_func, .test = _func }
+
+static MunitTest ei_tests[] = {
+	TEST(test_proto_next_message),
+	{ NULL },
+};
+
+static const MunitSuite libei_suite
+__attribute__((used))
+__attribute__((section("test_section"))) = {
+	"brei",
+	ei_tests,
+	NULL,
+	1,
+	MUNIT_SUITE_OPTION_NONE,
+};
+#endif

src/brei-shared.h

@@ -0,0 +1,39 @@
+/*
+ * Copyright © 2020 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#pragma once
+
+#include "config.h"
+
+/**
+ * The BREI (i.e. the EI protocol) is using Frames to separate the messages.
+ * This helper takes the data of length msglength and returns the position
+ * of the next actual message.
+ *
+ * @param msglen Length of data
+ * @param consumed The number of bytes consumed to advance to the next
+ * message
+ * @return The position of the next message
+ */
+const unsigned char *
+brei_next_message(const char *data, size_t *msglen, size_t *consumed);

src/libei-proto.c

@@ -31,6 +31,7 @@
 
 #include "proto/ei.pb-c.h"
 #include "libei-proto.h"
+#include "brei-shared.h"
 
 void
 message_free(struct message *msg)
@@ -42,50 +43,18 @@ message_free(struct message *msg)
 	free(msg);
 }
 
-static void frame_cleanup(Frame **f) {
-	if (*f)
-		frame__free_unpacked(*f, NULL);
-}
-
 static void servermessage_cleanup(ServerMessage **m) {
 	if (*m)
 		server_message__free_unpacked(*m, NULL);
 }
-#define _cleanup_frame_ _cleanup_(frame_cleanup)
 #define _cleanup_servermessage_ _cleanup_(servermessage_cleanup)
 
-static const unsigned char *
-next_message(const char *data, size_t *msglen, size_t *consumed)
-{
-	/* Every message is prefixed by a fixed-length Frame message which
-	 * contains the length of the next message. Frames are always the
-	 * same length, so we only need to calculate the size once.
-	 */
-	static size_t framelen = 0;
-
-	if (framelen == 0) {
-		Frame f = FRAME__INIT;
-		f.length = 0xffff;
-		framelen = frame__get_packed_size(&f);
-		assert(framelen >= 5);
-	}
-
-	_cleanup_frame_ Frame *frame = frame__unpack(NULL, framelen, (const unsigned char *)data);
-	if (!frame)
-		return NULL;
-
-	*msglen = frame->length;
-	*consumed = framelen;
-
-	return (const unsigned char*)data + framelen;
-}
-
 struct message *
 ei_proto_parse_message(const char *data, size_t len, size_t *consumed)
 {
 	size_t headerbytes = 0;
 	size_t msglen = 0;
-	const unsigned char *msgdata = next_message(data, &msglen, &headerbytes);
+	const unsigned char *msgdata = brei_next_message(data, &msglen, &headerbytes);
 
 	_cleanup_servermessage_ ServerMessage *proto = server_message__unpack(NULL, msglen, msgdata);
 	if (!proto)
@@ -288,62 +257,3 @@ ei_proto_send_key(struct ei *ei, struct ei_device *device,
 	return ei_proto_send_msg(ei, &msg);
 }
 
-
-#ifdef _enable_tests_
-#include <munit.h>
-
-static MunitResult
-test_proto_next_message(const MunitParameter params[], void *user_data)
-{
-	char data[64];
-
-	/* Invalid frame, rest can be random */
-	data[0] = 0xaa;
-
-	size_t msglen = 0xab;
-	size_t consumed = 0xbc;
-
-	const unsigned char *rval = next_message(data, &msglen, &consumed);
-	munit_assert_ptr_null(rval);
-	munit_assert_int(msglen, ==, 0xab);
-	munit_assert_int(consumed, ==, 0xbc);
-
-	/* Now try a valid one */
-	Frame f = FRAME__INIT;
-	f.length = 0xcd;
-	size_t framelen = frame__get_packed_size(&f);
-
-	unsigned char buf[framelen * 4];
-	for (int i = 0; i < 4; i++)
-		frame__pack(&f, buf + framelen * i);
-
-	const char *ptr = (char*)buf;
-	for (int i = 0; i < 4; i++) {
-		const unsigned char *next_frame = next_message(ptr, &msglen, &consumed);
-		munit_assert_ptr_equal(next_frame, buf + (i + 1) * framelen);
-		munit_assert_int(consumed, ==, framelen);
-		munit_assert_int(msglen, ==, 0xcd);
-		ptr += consumed;
-	}
-
-	return MUNIT_OK;
-}
-
-#define TEST(_func) \
-	{ .name = #_func, .test = _func }
-
-static MunitTest ei_tests[] = {
-	TEST(test_proto_next_message),
-	{ NULL },
-};
-
-static const MunitSuite libei_suite
-__attribute__((used))
-__attribute__((section("test_section"))) = {
-	"",
-	ei_tests,
-	NULL,
-	1,
-	MUNIT_SUITE_OPTION_NONE,
-};
-#endif