ping: fix unaligned access. closes bug 745.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

2 files changed, 4 insertions, 1 deletions

diff --git a/include/platform.h b/include/platform.h
index 8ed05a4ad..a41daa08c 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 c7b6cbe9a..4e770bdbd 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);