Re: [libvirt] [PATCH 1/3] util: add virendian.h macros

We have several cases where we need to read endian-dependent data regardless of host endianness; rather than open-coding these call sites, it will be nicer to funnel things through a macro. The virendian.h file can be expanded to add writer functions, and/or 16-bit access patterns, if needed. Also, if we need to turn things into a function to avoid multiple evaluations of buf, that can be done later. But for now, a macro worked. * src/util/virendian.h: New file. * src/Makefile.am (UTIL_SOURCES): Ship it. * tests/virendiantest.c: New test. * tests/Makefile.am (test_programs, virendiantest_SOURCES): Run the test. * .gitignore: Ignore built file. --- .gitignore | 1 + src/Makefile.am | 1 + src/util/virendian.h | 93 +++++++++++++++++++++++++++++++++++++++++++++ tests/Makefile.am | 8 +++- tests/virendiantest.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 203 insertions(+), 2 deletions(-) create mode 100644 src/util/virendian.h create mode 100644 tests/virendiantest.c diff --git a/.gitignore b/.gitignore index 1670637..8afbf33 100644 --- a/.gitignore +++ b/.gitignore @@ -177,6 +177,7 @@ /tests/virbitmaptest /tests/virbuftest /tests/virdrivermoduletest +/tests/virendiantest /tests/virhashtest /tests/virkeyfiletest /tests/virlockspacetest diff --git a/src/Makefile.am b/src/Makefile.am index f6162df..d554aa1 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -67,6 +67,7 @@ UTIL_SOURCES = \ util/virdbus.c util/virdbus.h \ util/virdnsmasq.c util/virdnsmasq.h \ util/virebtables.c util/virebtables.h \ + util/virendian.h \ util/virerror.c util/virerror.h \ util/virevent.c util/virevent.h \ util/vireventpoll.c util/vireventpoll.h \ diff --git a/src/util/virendian.h b/src/util/virendian.h new file mode 100644 index 0000000..eefe48c --- /dev/null +++ b/src/util/virendian.h @@ -0,0 +1,93 @@ +/* + * virendian.h: aid for reading endian-specific data + * + * Copyright (C) 2013 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>;. + * + */ + +#ifndef __VIR_ENDIAN_H__ +# define __VIR_ENDIAN_H__ + +# include "internal.h" + +/* The interfaces in this file are provided as macros for speed. */ + +/** + * virReadBufInt64BE: + * @buf: byte to start reading at (can be 'char*' or 'unsigned char*'); + * evaluating buf must not have any side effects + * + * Read 8 bytes at BUF as a big-endian 64-bit number. Caller is + * responsible to avoid reading beyond array bounds. + */ +# define virReadBufInt64BE(buf) \ + (((uint64_t)(uint8_t)((buf)[0]) << 56) | \ + ((uint64_t)(uint8_t)((buf)[1]) << 48) | \ + ((uint64_t)(uint8_t)((buf)[2]) << 40) | \ + ((uint64_t)(uint8_t)((buf)[3]) << 32) | \ + ((uint64_t)(uint8_t)((buf)[4]) << 24) | \ + ((uint64_t)(uint8_t)((buf)[5]) << 16) | \ + ((uint64_t)(uint8_t)((buf)[6]) << 8) | \ + (uint64_t)(uint8_t)((buf)[7])) + +/** + * virReadBufInt64LE: + * @buf: byte to start reading at (can be 'char*' or 'unsigned char*'); + * evaluating buf must not have any side effects + * + * Read 8 bytes at BUF as a little-endian 64-bit number. Caller is + * responsible to avoid reading beyond array bounds. + */ +# define virReadBufInt64LE(buf) \ + ((uint64_t)(uint8_t)((buf)[0]) | \ + ((uint64_t)(uint8_t)((buf)[1]) << 8) | \ + ((uint64_t)(uint8_t)((buf)[2]) << 16) | \ + ((uint64_t)(uint8_t)((buf)[3]) << 24) | \ + ((uint64_t)(uint8_t)((buf)[4]) << 32) | \ + ((uint64_t)(uint8_t)((buf)[5]) << 40) | \ + ((uint64_t)(uint8_t)((buf)[6]) << 48) | \ + ((uint64_t)(uint8_t)((buf)[7]) << 56)) + +/** + * virReadBufInt32BE: + * @buf: byte to start reading at (can be 'char*' or 'unsigned char*'); + * evaluating buf must not have any side effects + * + * Read 4 bytes at BUF as a big-endian 32-bit number. Caller is + * responsible to avoid reading beyond array bounds. + */ +# define virReadBufInt32BE(buf) \ + (((uint32_t)(uint8_t)((buf)[0]) << 24) | \ + ((uint32_t)(uint8_t)((buf)[1]) << 16) | \ + ((uint32_t)(uint8_t)((buf)[2]) << 8) | \ + (uint32_t)(uint8_t)((buf)[3])) + +/** + * virReadBufInt32LE: + * @buf: byte to start reading at (can be 'char*' or 'unsigned char*'); + * evaluating buf must not have any side effects + * + * Read 4 bytes at BUF as a little-endian 32-bit number. Caller is + * responsible to avoid reading beyond array bounds. + */ +# define virReadBufInt32LE(buf) \ + ((uint32_t)(uint8_t)((buf)[0]) | \ + ((uint32_t)(uint8_t)((buf)[1]) << 8) | \ + ((uint32_t)(uint8_t)((buf)[2]) << 16) | \ + ((uint32_t)(uint8_t)((buf)[3]) << 24)) + +#endif /* __VIR_ENDIAN_H__ */

diff --git a/tests/Makefile.am b/tests/Makefile.am index 0194db2..7d0a88e 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -1,6 +1,6 @@ ## Process this file with automake to produce Makefile.in -## Copyright (C) 2005-2012 Red Hat, Inc. +## Copyright (C) 2005-2013 Red Hat, Inc. ## See COPYING.LIB for the License of this software SHELL = $(PREFERABLY_POSIX_SHELL) @@ -95,7 +95,7 @@ test_programs = virshtest sockettest \ utiltest shunloadtest \ virtimetest viruritest virkeyfiletest \ virauthconfigtest \ - virbitmaptest \ + virbitmaptest virendiantest \ virlockspacetest \ virstringtest \ virportallocatortest \ @@ -649,6 +649,10 @@ virbitmaptest_SOURCES = \ virbitmaptest.c testutils.h testutils.c virbitmaptest_LDADD = $(LDADDS) +virendiantest_SOURCES = \ + virendiantest.c testutils.h testutils.c +virendiantest_LDADD = $(LDADDS) + jsontest_SOURCES = \ jsontest.c testutils.h testutils.c jsontest_LDADD = $(LDADDS) diff --git a/tests/virendiantest.c b/tests/virendiantest.c new file mode 100644 index 0000000..386ef33 --- /dev/null +++ b/tests/virendiantest.c @@ -0,0 +1,102 @@ +/* + * Copyright (C) 2013 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>;. + * + */ + +#include <config.h> + +#include "testutils.h" + +#include "virendian.h" + +static int +test1(const void *data ATTRIBUTE_UNUSED) +{ + /* Regular char should work, even if signed, and even with + * unaligned access. */ + char array[] = { 1, 2, 3, 4, 5, 6, 7, 8, + 0x89, 0x8a, 0x8b, 0x8c, 0x8d }; + int ret = -1; + + if (virReadBufInt64BE(array) != 0x0102030405060708ULL) + goto cleanup; + if (virReadBufInt64BE(array + 5) != 0x060708898a8b8c8dULL) + goto cleanup; + if (virReadBufInt64LE(array) != 0x0807060504030201ULL) + goto cleanup; + if (virReadBufInt64LE(array + 5) != 0x8d8c8b8a89080706ULL) + goto cleanup; + + if (virReadBufInt32BE(array) != 0x01020304U) + goto cleanup; + if (virReadBufInt32BE(array + 8) != 0x898a8b8cU) + goto cleanup; + if (virReadBufInt32LE(array) != 0x04030201U) + goto cleanup; + if (virReadBufInt32LE(array + 8) != 0x8c8b8a89U) + goto cleanup; + + ret = 0; +cleanup: + return ret; +} + +static int +test2(const void *data ATTRIBUTE_UNUSED) +{ + /* Unsigned char should work without cast, even if unaligned access. */ + unsigned char array[] = { 1, 2, 3, 4, 5, 6, 7, 8, + 0x89, 0x8a, 0x8b, 0x8c, 0x8d }; + int ret = -1; + + if (virReadBufInt64BE(array) != 0x0102030405060708ULL) + goto cleanup; + if (virReadBufInt64BE(array + 5) != 0x060708898a8b8c8dULL) + goto cleanup; + if (virReadBufInt64LE(array) != 0x0807060504030201ULL) + goto cleanup; + if (virReadBufInt64LE(array + 5) != 0x8d8c8b8a89080706ULL) + goto cleanup; + + if (virReadBufInt32BE(array) != 0x01020304U) + goto cleanup; + if (virReadBufInt32BE(array + 8) != 0x898a8b8cU) + goto cleanup; + if (virReadBufInt32LE(array) != 0x04030201U) + goto cleanup; + if (virReadBufInt32LE(array + 8) != 0x8c8b8a89U) + goto cleanup; + + ret = 0; +cleanup: + return ret; +} + +static int +mymain(void) +{ + int ret = 0; + + if (virtTestRun("test1", 1, test1, NULL) < 0) + ret = -1; + if (virtTestRun("test2", 1, test2, NULL) < 0) + ret = -1; + + return ret; +} + +VIRT_TEST_MAIN(mymain)