File target-isns-handle-big-endian-arch.patch of Package target-isns.3375

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File target-isns-handle-big-endian-arch.patch of Package target-isns.3375

From: Olaf Kirch <okir@suse.com>
Date: Wed Oct 14 10:51:18 PDT 2015
Subject: [PATCH] Handle big-endian architecture
Reference: bsc#950366

On a little Endian system, this will load addr with the IP address in
"wrong" order, ie if the address was 1.2.3.4, then addr will contain
04030201

ip[10] = ip[11] = 0xff;
                ip[15] = 0xff & (addr >> 24);
                ip[14] = 0xff & (addr >> 16);
                ip[13] = 0xff & (addr >> 8);
                ip[12] = 0xff & addr;

Using the example IP addr above, his will translate to

/* addr == 0x04030201 */
                ip[15] = 4; /* 0xff & (addr >> 24); */
                ip[14] = 3; /* 0xff & (addr >> 16); */
                ip[13] = 2; /* 0xff & (addr >> 8); */
                ip[12] = 1; /* 0xff & addr; */

On a big Endian system, the contents of addr will not be byte swapped,
and hence it will be stored in ip[] in the wrong order.

This picture doesn't change when using ntohl, because that is a NOP on
s390. The only effect of using ntohl is that it will now be broken on
x86_64 as well :-)

The real fix is to not bother with assigning to addr at all, but to do
a memcpy straight from &l.s4)->sin_addr to ip + 12. That doesn't need
any byte aerobics, as it just moves the data as-is.

Signed-of-by: Lee Duncan <lduncan@suse.com>
---
 src/isns.c |    8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

--- a/src/isns.c
+++ b/src/isns.c
@@ -76,7 +76,6 @@ static int isns_get_ip(int fd)
 {
 	int err;
 	size_t i;
-	uint32_t addr;
 	union {
 		struct sockaddr s;
 		struct sockaddr_storage ss;
@@ -103,13 +102,8 @@ static int isns_get_ip(int fd)
 
 	switch (l.ss.ss_family) {
 	case AF_INET:
-		addr = ((&l.s4)->sin_addr.s_addr);
-
 		ip[10] = ip[11] = 0xff;
-		ip[15] = 0xff & (addr >> 24);
-		ip[14] = 0xff & (addr >> 16);
-		ip[13] = 0xff & (addr >> 8);
-		ip[12] = 0xff & addr;
+		memcpy(ip + 12, &((&l.s4)->sin_addr), 4);
 		break;
 	case AF_INET6:
 		for (i = 0; i < ARRAY_SIZE(ip); i++)

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File target-isns-handle-big-endian-arch.patch of Package target-isns.3375

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