Subject: [PATCH net-next 1/3] tuntap: reorganize tun_msg_ctl usage

From: [email-masked]
Date: Sat, 12 Oct 2019 10:53:55 +0900

From: Prashant Bhole <[email-masked]>

In order to extend the usage of tun_msg_ctl structure, this patch
changes the member name from type to cmd. Also following definitions
are changed:
TUN_MSG_PTR : TUN_CMD_BATCH
TUN_MSG_UBUF: TUN_CMD_PACKET

Signed-off-by: Prashant Bhole <[email-masked]>
---
 drivers/net/tap.c      | 9 ++++++---
 drivers/net/tun.c      | 8 ++++++--
 drivers/vhost/net.c    | 4 ++--
 include/linux/if_tun.h | 6 +++---
 4 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index 3ae70c7e6860..01bd260ce60c 100644
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -1213,9 +1213,10 @@ static int tap_sendmsg(struct socket *sock, struct msghdr *m,
 	struct tap_queue *q = container_of(sock, struct tap_queue, sock);
 	struct tun_msg_ctl *ctl = m->msg_control;
 	struct xdp_buff *xdp;
+	void *ptr = NULL;
 	int i;
 
-	if (ctl && (ctl->type == TUN_MSG_PTR)) {
+	if (ctl && ctl->cmd == TUN_CMD_BATCH) {
 		for (i = 0; i < ctl->num; i++) {
 			xdp = &((struct xdp_buff *)ctl->ptr)[i];
 			tap_get_user_xdp(q, xdp);
@@ -1223,8 +1224,10 @@ static int tap_sendmsg(struct socket *sock, struct msghdr *m,
 		return 0;
 	}
 
-	return tap_get_user(q, ctl ? ctl->ptr : NULL, &m->msg_iter,
-			    m->msg_flags & MSG_DONTWAIT);
+	if (ctl && ctl->cmd == TUN_CMD_PACKET)
+		ptr = ctl->ptr;
+
+	return tap_get_user(q, ptr, &m->msg_iter, m->msg_flags & MSG_DONTWAIT);
 }
 
 static int tap_recvmsg(struct socket *sock, struct msghdr *m,
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 0413d182d782..29711671959b 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2529,11 +2529,12 @@ static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
 	struct tun_struct *tun = tun_get(tfile);
 	struct tun_msg_ctl *ctl = m->msg_control;
 	struct xdp_buff *xdp;
+	void *ptr = NULL;
 
 	if (!tun)
 		return -EBADFD;
 
-	if (ctl && (ctl->type == TUN_MSG_PTR)) {
+	if (ctl && ctl->cmd == TUN_CMD_BATCH) {
 		struct tun_page tpage;
 		int n = ctl->num;
 		int flush = 0;
@@ -2560,7 +2561,10 @@ static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
 		goto out;
 	}
 
-	ret = tun_get_user(tun, tfile, ctl ? ctl->ptr : NULL, &m->msg_iter,
+	if (ctl && ctl->cmd == TUN_CMD_PACKET)
+		ptr = ctl->ptr;
+
+	ret = tun_get_user(tun, tfile, ptr, &m->msg_iter,
 			   m->msg_flags & MSG_DONTWAIT,
 			   m->msg_flags & MSG_MORE);
 out:
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 1a2dd53caade..5946d2775bd0 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -462,7 +462,7 @@ static void vhost_tx_batch(struct vhost_net *net,
 			   struct msghdr *msghdr)
 {
 	struct tun_msg_ctl ctl = {
-		.type = TUN_MSG_PTR,
+		.cmd = TUN_CMD_BATCH,
 		.num = nvq->batched_xdp,
 		.ptr = nvq->xdp,
 	};
@@ -902,7 +902,7 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
 			ubuf->desc = nvq->upend_idx;
 			refcount_set(&ubuf->refcnt, 1);
 			msg.msg_control = &ctl;
-			ctl.type = TUN_MSG_UBUF;
+			ctl.cmd = TUN_CMD_PACKET;
 			ctl.ptr = ubuf;
 			msg.msg_controllen = sizeof(ctl);
 			ubufs = nvq->ubufs;
diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
index 5bda8cf457b6..bdfa671612db 100644
--- a/include/linux/if_tun.h
+++ b/include/linux/if_tun.h
@@ -11,10 +11,10 @@
 
 #define TUN_XDP_FLAG 0x1UL
 
-#define TUN_MSG_UBUF 1
-#define TUN_MSG_PTR  2
+#define TUN_CMD_PACKET 1
+#define TUN_CMD_BATCH  2
 struct tun_msg_ctl {
-	unsigned short type;
+	unsigned short cmd;
 	unsigned short num;
 	void *ptr;
 };
-- 
2.21.0