[git commit master] ping: fix unaligned access. closes bug 745.

[Denys Vlasenko]

commit: http://git.busybox.net/busybox/commit/?id=57be1eefab8494efd96bcec0f54a84cef3f61e95
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 include/platform.h |    2 ++
 networking/ping.c  |    3 ++-
 2 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/include/platform.h b/include/platform.h
index 8ed05a4..a41daa0 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -194,12 +194,14 @@
  * a lvalue. This makes it more likely to not swap them by mistake
  */
 #if defined(i386) || defined(__x86_64__)
+# define move_from_unaligned_int(v, intp) ((v) = *(int*)(intp))
 # define move_from_unaligned16(v, u16p) ((v) = *(uint16_t*)(u16p))
 # define move_from_unaligned32(v, u32p) ((v) = *(uint32_t*)(u32p))
 # define move_to_unaligned32(u32p, v)   (*(uint32_t*)(u32p) = (v))
 /* #elif ... - add your favorite arch today! */
 #else
 /* performs reasonably well (gcc usually inlines memcpy here) */
+# define move_from_unaligned_int(v, intp) (memcpy(&(v), (intp), sizeof(int)))
 # define move_from_unaligned16(v, u16p) (memcpy(&(v), (u16p), 2))
 # define move_from_unaligned32(v, u32p) (memcpy(&(v), (u32p), 4))
 # define move_to_unaligned32(u32p, v) do { \
diff --git a/networking/ping.c b/networking/ping.c
index c7b6cbe..4e770bd 100644
--- a/networking/ping.c
+++ b/networking/ping.c
@@ -690,7 +690,8 @@ static void ping6(len_and_sockaddr *lsa)
 			 /* don't check len - we trust the kernel: */
 			 /* && mp->cmsg_len >= CMSG_LEN(sizeof(int)) */
 			) {
-				hoplimit = *(int*)CMSG_DATA(mp);
+				/*hoplimit = *(int*)CMSG_DATA(mp); - unaligned access */
+				move_from_unaligned_int(hoplimit, CMSG_DATA(mp));
 			}
 		}
 		unpack6(packet, c, /*&from,*/ hoplimit);
-- 
1.6.3.3