tree-wide: drop 'This file is part of systemd' blurb

[elogind.git] / src / basic / unaligned.h

diff --git a/src/basic/unaligned.h b/src/basic/unaligned.h
index a8115eaa1f6d996aada4d5519e3a987f4943304f..0bb62b319551af932e13eb0a5833c3fa3201fa38 100644 (file)
--- a/src/basic/unaligned.h
+++ b/src/basic/unaligned.h
@@ -1,24 +1,8 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
+/* SPDX-License-Identifier: LGPL-2.1+ */
 #pragma once
 
 /***
-  This file is part of systemd.
-
   Copyright 2014 Tom Gundersen
-
-  systemd 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.
-
-  systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
 #include <endian.h>
@@ -27,87 +11,93 @@
 /* BE */
 
 static inline uint16_t unaligned_read_be16(const void *_u) {
-        const uint8_t *u = _u;
+        const struct __attribute__((packed, may_alias)) { uint16_t x; } *u = _u;
 
-        return (((uint16_t) u[0]) << 8) |
-                ((uint16_t) u[1]);
+        return be16toh(u->x);
 }
 
 static inline uint32_t unaligned_read_be32(const void *_u) {
-        const uint8_t *u = _u;
+        const struct __attribute__((packed, may_alias)) { uint32_t x; } *u = _u;
 
-        return (((uint32_t) unaligned_read_be16(u)) << 16) |
-                ((uint32_t) unaligned_read_be16(u + 2));
+        return be32toh(u->x);
 }
 
 static inline uint64_t unaligned_read_be64(const void *_u) {
-        const uint8_t *u = _u;
+        const struct __attribute__((packed, may_alias)) { uint64_t x; } *u = _u;
 
-        return (((uint64_t) unaligned_read_be32(u)) << 32) |
-                ((uint64_t) unaligned_read_be32(u + 4));
+        return be64toh(u->x);
 }
 
 static inline void unaligned_write_be16(void *_u, uint16_t a) {
-        uint8_t *u = _u;
+        struct __attribute__((packed, may_alias)) { uint16_t x; } *u = _u;
 
-        u[0] = (uint8_t) (a >> 8);
-        u[1] = (uint8_t) a;
+        u->x = be16toh(a);
 }
 
 static inline void unaligned_write_be32(void *_u, uint32_t a) {
-        uint8_t *u = _u;
+        struct __attribute__((packed, may_alias)) { uint32_t x; } *u = _u;
 
-        unaligned_write_be16(u, (uint16_t) (a >> 16));
-        unaligned_write_be16(u + 2, (uint16_t) a);
+        u->x = be32toh(a);
 }
 
 static inline void unaligned_write_be64(void *_u, uint64_t a) {
-        uint8_t *u = _u;
+        struct __attribute__((packed, may_alias)) { uint64_t x; } *u = _u;
 
-        unaligned_write_be32(u, (uint32_t) (a >> 32));
-        unaligned_write_be32(u + 4, (uint32_t) a);
+        u->x = be64toh(a);
 }
 
 /* LE */
 
 static inline uint16_t unaligned_read_le16(const void *_u) {
-        const uint8_t *u = _u;
+        const struct __attribute__((packed, may_alias)) { uint16_t x; } *u = _u;
 
-        return (((uint16_t) u[1]) << 8) |
-                ((uint16_t) u[0]);
+        return le16toh(u->x);
 }
 
 static inline uint32_t unaligned_read_le32(const void *_u) {
-        const uint8_t *u = _u;
+        const struct __attribute__((packed, may_alias)) { uint32_t x; } *u = _u;
 
-        return (((uint32_t) unaligned_read_le16(u + 2)) << 16) |
-                ((uint32_t) unaligned_read_le16(u));
+        return le32toh(u->x);
 }
 
 static inline uint64_t unaligned_read_le64(const void *_u) {
-        const uint8_t *u = _u;
+        const struct __attribute__((packed, may_alias)) { uint64_t x; } *u = _u;
 
-        return (((uint64_t) unaligned_read_le32(u + 4)) << 32) |
-                ((uint64_t) unaligned_read_le32(u));
+        return le64toh(u->x);
 }
 
 static inline void unaligned_write_le16(void *_u, uint16_t a) {
-        uint8_t *u = _u;
+        struct __attribute__((packed, may_alias)) { uint16_t x; } *u = _u;
 
-        u[0] = (uint8_t) a;
-        u[1] = (uint8_t) (a >> 8);
+        u->x = le16toh(a);
 }
 
 static inline void unaligned_write_le32(void *_u, uint32_t a) {
-        uint8_t *u = _u;
+        struct __attribute__((packed, may_alias)) { uint32_t x; } *u = _u;
 
-        unaligned_write_le16(u, (uint16_t) a);
-        unaligned_write_le16(u + 2, (uint16_t) (a >> 16));
+        u->x = le32toh(a);
 }
 
 static inline void unaligned_write_le64(void *_u, uint64_t a) {
-        uint8_t *u = _u;
+        struct __attribute__((packed, may_alias)) { uint64_t x; } *u = _u;
 
-        unaligned_write_le32(u, (uint32_t) a);
-        unaligned_write_le32(u + 4, (uint32_t) (a >> 32));
+        u->x = le64toh(a);
 }
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define unaligned_read_ne16 unaligned_read_be16
+#define unaligned_read_ne32 unaligned_read_be32
+#define unaligned_read_ne64 unaligned_read_be64
+
+#define unaligned_write_ne16 unaligned_write_be16
+#define unaligned_write_ne32 unaligned_write_be32
+#define unaligned_write_ne64 unaligned_write_be64
+#else
+#define unaligned_read_ne16 unaligned_read_le16
+#define unaligned_read_ne32 unaligned_read_le32
+#define unaligned_read_ne64 unaligned_read_le64
+
+#define unaligned_write_ne16 unaligned_write_le16
+#define unaligned_write_ne32 unaligned_write_le32
+#define unaligned_write_ne64 unaligned_write_le64
+#endif