Create a random epoch value rather than a time-based one on startup and set
the top bit to indicate that this is the case.
Also create a random starting client connection ID value. This will be
incremented from here as new client connections are created.
Signed-off-by: David Howells <dhowe...@redhat.com>
---
include/rxrpc/packet.h | 1 +
net/rxrpc/af_rxrpc.c | 9 ++++++++-
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/include/rxrpc/packet.h b/include/rxrpc/packet.h
index b2017440b765..3c6128e1fdbe 100644
--- a/include/rxrpc/packet.h
+++ b/include/rxrpc/packet.h
@@ -24,6 +24,7 @@ typedef __be32 rxrpc_serial_net_t; /* on-the-wire Rx
message serial number */
*/
struct rxrpc_wire_header {
__be32 epoch; /* client boot timestamp */
+#define RXRPC_RANDOM_EPOCH 0x80000000 /* Random if set, date-based if
not */
__be32 cid; /* connection and channel ID */
#define RXRPC_MAXCALLS 4 /* max active calls per
conn */
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 32d544995dda..b66a9e6f8d04 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -16,6 +16,7 @@
#include <linux/net.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
+#include <linux/random.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/key-type.h>
@@ -700,7 +701,13 @@ static int __init af_rxrpc_init(void)
BUILD_BUG_ON(sizeof(struct rxrpc_skb_priv) > FIELD_SIZEOF(struct
sk_buff, cb));
- rxrpc_epoch = get_seconds();
+ get_random_bytes(&rxrpc_epoch, sizeof(rxrpc_epoch));
+ rxrpc_epoch |= RXRPC_RANDOM_EPOCH;
+ get_random_bytes(&rxrpc_client_conn_ids.cur,
+ sizeof(rxrpc_client_conn_ids.cur));
+ rxrpc_client_conn_ids.cur &= 0x3fffffff;
+ if (rxrpc_client_conn_ids.cur == 0)
+ rxrpc_client_conn_ids.cur = 1;
ret = -ENOMEM;
rxrpc_call_jar = kmem_cache_create(
