rtnl_wilddump_request: fix alignment issue for embedded platforms
Platforms have different alignment requirements which need to be
fulfilled by the compiler. If the structure elements are already
4 byte (NLMGS_ALIGNTO) aligned by the compiler adding an explicit
padding element (align_rta) is not allowed.
Use __attribute__ ((aligned (NLMSG_ALIGNTO))) in order to achieve
the required alignment.
Experienced on ARM (xscale) with symptom
netlink: 12 bytes leftover after parsing attributes
Tested on:
ARM (32bit Big Endian)
PowerPC (32bit Big Endian)
x86_64 (64bit Little Endian)
Each with different aligment requirments.
Signed-off-by: Lutz Jaenicke <ljaenicke@innominate.com>
diff --git a/lib/libnetlink.c b/lib/libnetlink.c
index 8e8c8b9..09b4277 100644
--- a/lib/libnetlink.c
+++ b/lib/libnetlink.c
@@ -94,8 +94,8 @@
struct {
struct nlmsghdr nlh;
struct rtgenmsg g;
- __u16 align_rta; /* attribute has to be 32bit aligned */
- struct rtattr ext_req;
+ /* attribute has to be NLMSG aligned */
+ struct rtattr ext_req __attribute__ ((aligned(NLMSG_ALIGNTO)));
__u32 ext_filter_mask;
} req;