[PATCH v2 1/8] icmp, udp: Pad time_t timestamp to 64-bit to ease state migration

[Stefano Brivio <sbrivio@redhat.com>]

That's the only field in flows with different storage sizes depending
on the architecture: it's usually 4-byte wide on 32-bit architectures,
except for arc and x32 where it's 8 bytes, and 8-byte wide on 64-bit
machines.

By keeping flow entries the same size across architectures, we avoid
having to expand or shrink table entries upon migration.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
 icmp_flow.h | 6 +++++-
 udp_flow.h  | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/icmp_flow.h b/icmp_flow.h
index fb93801..da7e255 100644
--- a/icmp_flow.h
+++ b/icmp_flow.h
@@ -13,6 +13,7 @@
  * @seq:	Last sequence number sent to tap, host order, -1: not sent yet
  * @sock:	"ping" socket
  * @ts:		Last associated activity from tap, seconds
+ * @ts_storage:	Pad @ts to 64-bit storage to keep state migration sane
  */
 struct icmp_ping_flow {
 	/* Must be first element */
@@ -20,7 +21,10 @@ struct icmp_ping_flow {
 
 	int seq;
 	int sock;
-	time_t ts;
+	union {
+		time_t ts;
+		uint64_t ts_storage;
+	};
 };
 
 bool icmp_ping_timer(const struct ctx *c, const struct icmp_ping_flow *pingf,
diff --git a/udp_flow.h b/udp_flow.h
index 9a1b059..9cb79a0 100644
--- a/udp_flow.h
+++ b/udp_flow.h
@@ -12,6 +12,7 @@
  * @f:		Generic flow information
  * @closed:	Flow is already closed
  * @ts:		Activity timestamp
+ * @ts_storage:	Pad @ts to 64-bit storage to keep state migration sane
  * @s:		Socket fd (or -1) for each side of the flow
  */
 struct udp_flow {
@@ -19,7 +20,10 @@ struct udp_flow {
 	struct flow_common f;
 
 	bool closed :1;
-	time_t ts;
+	union {
+		time_t ts;
+		uint64_t ts_storage;
+	};
 	int s[SIDES];
 };
 
-- 
@@ -12,6 +12,7 @@
  * @f:		Generic flow information
  * @closed:	Flow is already closed
  * @ts:		Activity timestamp
+ * @ts_storage:	Pad @ts to 64-bit storage to keep state migration sane
  * @s:		Socket fd (or -1) for each side of the flow
  */
 struct udp_flow {
@@ -19,7 +20,10 @@ struct udp_flow {
 	struct flow_common f;
 
 	bool closed :1;
-	time_t ts;
+	union {
+		time_t ts;
+		uint64_t ts_storage;
+	};
 	int s[SIDES];
 };
 
-- 
2.43.0