[PATCH net-next 2/8] ovpn: pktid: use bitops.h API

[Antonio Quartulli <antonio@openvpn.net>]

From: Qingfang Deng <dqfext@gmail.com>

Use bitops.h for replay window to simplify code.

Signed-off-by: Qingfang Deng <dqfext@gmail.com>
[antonio@openvpn.net: extended commit message]
Signed-off-by: Antonio Quartulli <antonio@openvpn.net>
---
 drivers/net/ovpn/pktid.c | 11 ++++-------
 drivers/net/ovpn/pktid.h |  2 +-
 2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ovpn/pktid.c b/drivers/net/ovpn/pktid.c
index 2f29049897e3..f1c243b84463 100644
--- a/drivers/net/ovpn/pktid.c
+++ b/drivers/net/ovpn/pktid.c
@@ -65,7 +65,7 @@ int ovpn_pktid_recv(struct ovpn_pktid_recv *pr, u32 pkt_id, u32 pkt_time)
 	if (likely(pkt_id == pr->id + 1)) {
 		/* well-formed ID sequence (incremented by 1) */
 		pr->base = REPLAY_INDEX(pr->base, -1);
-		pr->history[pr->base / 8] |= (1 << (pr->base % 8));
+		__set_bit(pr->base, pr->history);
 		if (pr->extent < REPLAY_WINDOW_SIZE)
 			++pr->extent;
 		pr->id = pkt_id;
@@ -77,14 +77,14 @@ int ovpn_pktid_recv(struct ovpn_pktid_recv *pr, u32 pkt_id, u32 pkt_time)
 			unsigned int i;
 
 			pr->base = REPLAY_INDEX(pr->base, -delta);
-			pr->history[pr->base / 8] |= (1 << (pr->base % 8));
+			__set_bit(pr->base, pr->history);
 			pr->extent += delta;
 			if (pr->extent > REPLAY_WINDOW_SIZE)
 				pr->extent = REPLAY_WINDOW_SIZE;
 			for (i = 1; i < delta; ++i) {
 				unsigned int newb = REPLAY_INDEX(pr->base, i);
 
-				pr->history[newb / 8] &= ~BIT(newb % 8);
+				__clear_bit(newb, pr->history);
 			}
 		} else {
 			pr->base = 0;
@@ -103,14 +103,11 @@ int ovpn_pktid_recv(struct ovpn_pktid_recv *pr, u32 pkt_id, u32 pkt_time)
 			if (pkt_id > pr->id_floor) {
 				const unsigned int ri = REPLAY_INDEX(pr->base,
 								     delta);
-				u8 *p = &pr->history[ri / 8];
-				const u8 mask = (1 << (ri % 8));
 
-				if (*p & mask) {
+				if (__test_and_set_bit(ri, pr->history)) {
 					ret = -EINVAL;
 					goto out;
 				}
-				*p |= mask;
 			} else {
 				ret = -EINVAL;
 				goto out;
diff --git a/drivers/net/ovpn/pktid.h b/drivers/net/ovpn/pktid.h
index 0262d026d15e..21845f353bc8 100644
--- a/drivers/net/ovpn/pktid.h
+++ b/drivers/net/ovpn/pktid.h
@@ -34,7 +34,7 @@ struct ovpn_pktid_xmit {
  */
 struct ovpn_pktid_recv {
 	/* "sliding window" bitmask of recent packet IDs received */
-	u8 history[REPLAY_WINDOW_BYTES];
+	DECLARE_BITMAP(history, REPLAY_WINDOW_SIZE);
 	/* bit position of deque base in history */
 	unsigned int base;
 	/* extent (in bits) of deque in history */
-- 
2.51.0