From 249e092967195b38b2fb466f310cc0b7611791b9 Mon Sep 17 00:00:00 2001
From: Alexander Amelkin <alexander@amelkin.msk.ru>
Date: Fri, 20 Jul 2018 19:41:44 +0300
Subject: [PATCH] general: Make byteswapping arch-independent

ipmiXXtoh() and htoipmiXX() functions were broken
and only worked properly for big-endian hosts.

This commit makes them endianness-independent.

Signed-off-by: Alexander Amelkin <alexander@amelkin.msk.ru>
---
 include/ipmitool/helper.h | 59 +++++++++++++++++++++++++++++++++++----
 1 file changed, 53 insertions(+), 6 deletions(-)

diff --git a/include/ipmitool/helper.h b/include/ipmitool/helper.h
index e8624e0..48873ef 100644
--- a/include/ipmitool/helper.h
+++ b/include/ipmitool/helper.h
@@ -118,16 +118,31 @@ static inline uint16_t ipmi16toh(void *ipmi16)
 	uint8_t *ipmi = (uint8_t *)ipmi16;
 	uint16_t h;
 
+	/*
+	 * ipmi16 address may be word-wise misaligned, so don't
+	 * use type-pun and instead explicity shift corresponding bytes
+	 * to where they belong.
+	 */
+#if WORDS_BIGENDIAN
+	h = ipmi[0] << 8; /* MSB */
+	h |= ipmi[1]; /* LSB */
+#else
 	h = ipmi[1] << 8; /* MSB */
 	h |= ipmi[0]; /* LSB */
+#endif
 
 	return h;
 }
 
 static inline void htoipmi16(uint16_t h, uint8_t *ipmi)
 {
+#if WORDS_BIGENDIAN
 	ipmi[0] = h & 0xFF; /* LSB */
 	ipmi[1] = h >> 8; /* MSB */
+#else
+	ipmi[1] = h & 0xFF; /* LSB */
+	ipmi[0] = h >> 8; /* MSB */
+#endif
 }
 
 static inline uint32_t ipmi24toh(void *ipmi24)
@@ -135,26 +150,58 @@ static inline uint32_t ipmi24toh(void *ipmi24)
 	uint8_t *ipmi = (uint8_t *)ipmi24;
 	uint32_t h = 0;
 
-	h = ipmi[2] << 16;
+#if WORDS_BIGENDIAN
+	h = ipmi[0] << 16; /* LSB */
 	h |= ipmi[1] << 8;
-	h |= ipmi[0];
+	h |= ipmi[2]; /* MSB */
+#else
+	h = ipmi[2] << 16; /* LSB */
+	h |= ipmi[1] << 8;
+	h |= ipmi[0]; /* MSB */
+#endif
 
 	return h;
 }
 
 static inline uint32_t ipmi32toh(void *ipmi32)
 {
-	uint8_t *ipmi = (uint8_t *)ipmi32;
+	uint8_t *ipmi = ipmi32;
 	uint32_t h;
 
-	h = ipmi[3] << 24;
+	/*
+	 * ipmi32 address may be dword-wise misaligned, so don't
+	 * use type-pun and instead explicity shift corresponding bytes
+	 * to where they belong.
+	 */
+#if WORDS_BIGENDIAN
+	h = ipmi[0] << 24; /* LSB */
+	h |= ipmi[1] << 16;
+	h |= ipmi[2] << 8;
+	h |= ipmi[3]; /* MSB */
+#else
+	h = ipmi[3] << 24; /* LSB */
 	h |= ipmi[2] << 16;
 	h |= ipmi[1] << 8;
-	h |= ipmi[0];
-
+	h |= ipmi[0]; /* MSB */
+#endif
 	return h;
 }
 
+static inline void htoipmi32(uint32_t h, uint8_t *ipmi)
+{
+#if WORDS_BIGENDIAN
+	ipmi[0] = h & 0xFF; /* LSB */
+	ipmi[1] = (h >> 8) & 0xFF;
+	ipmi[2] = (h >> 16) & 0xFF;
+	ipmi[3] = (h >> 24) & 0xFF; /* MSB */
+#else
+	ipmi[3] = h & 0xFF; /* LSB */
+	ipmi[2] = (h >> 8) & 0xFF;
+	ipmi[1] = (h >> 16) & 0xFF;
+	ipmi[0] = (h >> 24) & 0xFF; /* MSB */
+#endif
+}
+
 #define ipmi_open_file_read(file)	ipmi_open_file(file, 0)
 #define ipmi_open_file_write(file)	ipmi_open_file(file, 1)