[SCTP] Fix SCTP socket options to work with 32-bit apps on 64-bit kernels.

Adds alignment attribute to a few structures used with SCTP socket
options so that the sizes and offsets remain the same when built using
either 32 or 64 bit tools.
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sctp/user.h

@@ -243,7 +243,7 @@ struct sctp_paddr_change {
 	int spc_state;
 	int spc_error;
 	sctp_assoc_t spc_assoc_id;
-};
+} __attribute__((packed, aligned(4)));
 
 /*
  *    spc_state:  32 bits (signed integer)
@@ -468,7 +468,7 @@ struct sctp_assocparams {
 struct sctp_setpeerprim {
 	sctp_assoc_t            sspp_assoc_id;
 	struct sockaddr_storage sspp_addr;
-};
+} __attribute__((packed, aligned(4)));
 
 /*
  * 7.1.10 Set Primary Address (SCTP_PRIMARY_ADDR)
@@ -481,7 +481,7 @@ struct sctp_setpeerprim {
 struct sctp_prim {
 	sctp_assoc_t            ssp_assoc_id;
 	struct sockaddr_storage ssp_addr;
-};
+} __attribute__((packed, aligned(4)));
 
 /*
  * 7.1.11 Set Adaption Layer Indicator (SCTP_ADAPTION_LAYER)
@@ -508,7 +508,7 @@ struct sctp_paddrparams {
 	struct sockaddr_storage	spp_address;
 	__u32			spp_hbinterval;
 	__u16			spp_pathmaxrxt;
-};
+} __attribute__((packed, aligned(4)));
 
 /*
  * 7.2.2 Peer Address Information
@@ -527,7 +527,7 @@ struct sctp_paddrinfo {
 	__u32			spinfo_srtt;
 	__u32			spinfo_rto;
 	__u32			spinfo_mtu;
-};
+} __attribute__((packed, aligned(4)));
 
 /* Peer addresses's state. */
 enum sctp_spinfo_state {