[test] Add self-tests for TCP/IP checksum calculation

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/tests/tcpip_test.c

@@ -0,0 +1,213 @@
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/** @file
+ *
+ * TCP/IP self-tests
+ *
+ */
+
+/* Forcibly enable assertions */
+#undef NDEBUG
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <ipxe/test.h>
+#include <ipxe/profile.h>
+#include <ipxe/tcpip.h>
+
+/** A TCP/IP fixed-data test */
+struct tcpip_test {
+	/** Data */
+	const void *data;
+	/** Length of data */
+	size_t len;
+};
+
+/** A TCP/IP pseudorandom-data test */
+struct tcpip_random_test {
+	/** Seed */
+	unsigned int seed;
+	/** Length of data */
+	size_t len;
+	/** Alignment offset */
+	size_t offset;
+};
+
+/** Define inline data */
+#define DATA(...) { __VA_ARGS__ }
+
+/** Define a TCP/IP fixed-data test */
+#define TCPIP_TEST( name, DATA )					\
+	static const uint8_t __attribute__ (( aligned ( 16 ) ))		\
+		name ## _data[] = DATA;					\
+	static struct tcpip_test name = {				\
+		.data = name ## _data,					\
+		.len = sizeof ( name ## _data ),			\
+	}
+
+/** Define a TCP/IP pseudorandom-data test */
+#define TCPIP_RANDOM_TEST( name, SEED, LEN, OFFSET )			\
+	static struct tcpip_random_test name = {			\
+		.seed = SEED,						\
+		.len = LEN,						\
+		.offset = OFFSET,					\
+	}
+
+/** Buffer for pseudorandom-data tests */
+static uint8_t __attribute__ (( aligned ( 16 ) ))
+	tcpip_data[ 4096 + 7 /* offset */ ];
+
+/** Empty data */
+TCPIP_TEST ( empty, DATA() );
+
+/** Single byte */
+TCPIP_TEST ( one_byte, DATA ( 0xeb ) );
+
+/** Double byte */
+TCPIP_TEST ( two_bytes, DATA ( 0xba, 0xbe ) );
+
+/** Final wrap-around carry (big-endian) */
+TCPIP_TEST ( final_carry_big,
+	     DATA ( 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 ) );
+
+/** Final wrap-around carry (little-endian) */
+TCPIP_TEST ( final_carry_little,
+	     DATA ( 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00 ) );
+
+/** Random data (aligned) */
+TCPIP_RANDOM_TEST ( random_aligned, 0x12345678UL, 4096, 0 );
+
+/** Random data (unaligned, +1) */
+TCPIP_RANDOM_TEST ( random_unaligned_1, 0x12345678UL, 4096, 1 );
+
+/** Random data (unaligned, +2) */
+TCPIP_RANDOM_TEST ( random_unaligned_2, 0x12345678UL, 4096, 2 );
+
+/** Random data (aligned, truncated) */
+TCPIP_RANDOM_TEST ( random_aligned_truncated, 0x12345678UL, 4095, 0 );
+
+/** Random data (unaligned start and finish) */
+TCPIP_RANDOM_TEST ( partial, 0xcafebabe, 121, 5 );
+
+/**
+ * Calculate TCP/IP checksum
+ *
+ * @v data		Data to sum
+ * @v len		Length of data
+ * @ret cksum		Checksum
+ *
+ * This is a reference implementation taken from RFC1071 (and modified
+ * to fix compilation without warnings under gcc).
+ */
+static uint16_t rfc_tcpip_chksum ( const void *data, size_t len ) {
+	unsigned long sum = 0;
+
+        while ( len > 1 )  {
+		sum += *( ( uint16_t * ) data );
+		data += 2;
+		len -= 2;
+	}
+
+	if ( len > 0 )
+		sum += *( ( uint8_t * ) data );
+
+	while ( sum >> 16 )
+		sum = ( ( sum & 0xffff ) + ( sum >> 16 ) );
+
+	return ~sum;
+}
+
+/**
+ * Report TCP/IP fixed-data test result
+ *
+ * @v test		TCP/IP test
+ */
+#define tcpip_ok( test ) do {						\
+	uint16_t expected;						\
+	uint16_t generic_sum;						\
+	uint16_t sum;							\
+	expected = rfc_tcpip_chksum ( (test)->data, (test)->len );	\
+	generic_sum = generic_tcpip_continue_chksum ( TCPIP_EMPTY_CSUM,	\
+						      (test)->data,	\
+						      (test)->len );	\
+	ok ( generic_sum == expected );					\
+	sum = tcpip_continue_chksum ( TCPIP_EMPTY_CSUM, (test)->data,	\
+				      (test)->len );			\
+	ok ( sum == expected );						\
+	} while ( 0 )
+
+/**
+ * Report TCP/IP pseudorandom-data test result
+ *
+ * @v test		TCP/IP test
+ */
+#define tcpip_random_ok( test ) do {					\
+	uint8_t *data = ( tcpip_data + (test)->offset );		\
+	uint16_t expected;						\
+	uint16_t generic_sum;						\
+	uint16_t sum;							\
+	unsigned long elapsed;						\
+	unsigned int i;							\
+	assert ( ( (test)->len + (test)->offset ) <=			\
+		 sizeof ( tcpip_data ) );				\
+	srandom ( (test)->seed );					\
+	for ( i = 0 ; i < (test)->len ; i++ )				\
+		data[i] = random();					\
+	expected = rfc_tcpip_chksum ( data, (test)->len );		\
+	generic_sum = generic_tcpip_continue_chksum ( TCPIP_EMPTY_CSUM,	\
+						      data,		\
+						      (test)->len );	\
+	ok ( generic_sum == expected );					\
+	simple_profile();						\
+	sum = tcpip_continue_chksum ( TCPIP_EMPTY_CSUM, data,		\
+				      (test)->len );			\
+	elapsed = simple_profile();					\
+	ok ( sum == expected );						\
+	DBG ( "TCPIP checksummed %zd bytes (+%zd) in %ld ticks\n",	\
+	      (test)->len, (test)->offset, elapsed );			\
+	} while ( 0 )
+
+/**
+ * Perform TCP/IP self-tests
+ *
+ */
+static void tcpip_test_exec ( void ) {
+
+	tcpip_ok ( &empty );
+	tcpip_ok ( &one_byte );
+	tcpip_ok ( &two_bytes );
+	tcpip_ok ( &final_carry_big );
+	tcpip_ok ( &final_carry_little );
+	tcpip_random_ok ( &random_aligned );
+	tcpip_random_ok ( &random_unaligned_1 );
+	tcpip_random_ok ( &random_unaligned_2 );
+	tcpip_random_ok ( &random_aligned_truncated );
+	tcpip_random_ok ( &partial );
+}
+
+/** TCP/IP self-test */
+struct self_test tcpip_test __self_test = {
+	.name = "tcpip",
+	.exec = tcpip_test_exec,
+};

src/tests/tests.c

@@ -31,6 +31,7 @@ REQUIRE_OBJECT ( byteswap_test );
 REQUIRE_OBJECT ( base64_test );
 REQUIRE_OBJECT ( settings_test );
 REQUIRE_OBJECT ( time_test );
+REQUIRE_OBJECT ( tcpip_test );
 REQUIRE_OBJECT ( crc32_test );
 REQUIRE_OBJECT ( md5_test );
 REQUIRE_OBJECT ( sha1_test );