From 0a7c084603663a1e63b01bd677429a20bc7d4c62 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 1 Jul 2013 15:57:44 +0200 Subject: [PATCH] scsi-lowlevel: do not use unsafe pointer casts Casting unsigned char * pointers to uint32_t * may cause wrong results if the pointers are not correctly aligned. Instead, build up the big-endian values from each byte with multiple dereferences of the original pointer. Signed-off-by: Paolo Bonzini --- lib/scsi-lowlevel.c | 36 +++++++++++++++++++++--------------- 1 file changed, 21 insertions(+), 15 deletions(-) diff --git a/lib/scsi-lowlevel.c b/lib/scsi-lowlevel.c index ad94eef..37f41d5 100644 --- a/lib/scsi-lowlevel.c +++ b/lib/scsi-lowlevel.c @@ -212,10 +212,10 @@ scsi_get_uint64(const unsigned char *c) { uint64_t val; - val = ntohl(*(uint32_t *)c); + val = scsi_get_uint32(c); val <<= 32; c += 4; - val |= ntohl(*(uint32_t *)c); + val |= scsi_get_uint32(c); return val; } @@ -223,13 +223,21 @@ scsi_get_uint64(const unsigned char *c) inline uint32_t scsi_get_uint32(const unsigned char *c) { - return ntohl(*(uint32_t *)c); + uint32_t val; + val = c[0]; + val = (val << 8) | c[1]; + val = (val << 8) | c[2]; + val = (val << 8) | c[3]; + return val; } inline uint16_t scsi_get_uint16(const unsigned char *c) { - return ntohs(*(uint16_t *)c); + uint16_t val; + val = c[0]; + val = (val << 8) | c[1]; + return val; } static inline uint64_t @@ -237,14 +245,8 @@ task_get_uint64(struct scsi_task *task, int offset) { if (offset <= task->datain.size - 8) { const unsigned char *c = &task->datain.data[offset]; - uint64_t val; - val = ntohl(*(uint32_t *)c); - val <<= 32; - c += 4; - val |= ntohl(*(uint32_t *)c); - - return val; + return scsi_get_uint64(c); } else { return 0; } @@ -256,7 +258,7 @@ task_get_uint32(struct scsi_task *task, int offset) if (offset <= task->datain.size - 4) { const unsigned char *c = &task->datain.data[offset]; - return ntohl(*(uint32_t *)c); + return scsi_get_uint32(c); } else { return 0; } @@ -268,7 +270,7 @@ task_get_uint16(struct scsi_task *task, int offset) if (offset <= task->datain.size - 2) { const unsigned char *c = &task->datain.data[offset]; - return ntohs(*(uint16_t *)c); + return scsi_get_uint16(c); } else { return 0; } @@ -300,13 +302,17 @@ scsi_set_uint64(unsigned char *c, uint64_t v) inline void scsi_set_uint32(unsigned char *c, uint32_t val) { - *(uint32_t *)c = htonl(val); + c[0] = val >> 24; + c[1] = val >> 16; + c[2] = val >> 8; + c[3] = val; } inline void scsi_set_uint16(unsigned char *c, uint16_t val) { - *(uint16_t *)c = htons(val); + c[0] = val >> 8; + c[1] = val; } /* -- 1.8.1.4