diff mbox series

[net,v3,9/9] tap: Use tun's vnet-related code

Message ID 20250116-tun-v3-9-c6b2871e97f7@daynix.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series tun: Unify vnet implementation | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present fail Series targets non-next tree, but doesn't contain any Fixes tags
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: andrew+netdev@lunn.ch
netdev/build_clang success Errors and warnings before: 36 this patch: 36
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5 this patch: 5
netdev/checkpatch warning WARNING: line length of 84 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 5 now: 0

Commit Message

Akihiko Odaki Jan. 16, 2025, 8:08 a.m. UTC
tun and tap implements the same vnet-related features so reuse the code.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
---
 drivers/net/Kconfig    |   1 +
 drivers/net/Makefile   |   6 +-
 drivers/net/tap.c      | 152 +++++--------------------------------------------
 drivers/net/tun_vnet.c |   5 ++
 4 files changed, 24 insertions(+), 140 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 1fd5acdc73c6..c420418473fc 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -395,6 +395,7 @@  config TUN
 	tristate "Universal TUN/TAP device driver support"
 	depends on INET
 	select CRC32
+	select TAP
 	help
 	  TUN/TAP provides packet reception and transmission for user space
 	  programs.  It can be viewed as a simple Point-to-Point or Ethernet
diff --git a/drivers/net/Makefile b/drivers/net/Makefile
index bb8eb3053772..2275309a97ee 100644
--- a/drivers/net/Makefile
+++ b/drivers/net/Makefile
@@ -29,9 +29,9 @@  obj-y += mdio/
 obj-y += pcs/
 obj-$(CONFIG_RIONET) += rionet.o
 obj-$(CONFIG_NET_TEAM) += team/
-obj-$(CONFIG_TUN) += tun-drv.o
-tun-drv-y := tun.o tun_vnet.o
-obj-$(CONFIG_TAP) += tap.o
+obj-$(CONFIG_TUN) += tun.o
+obj-$(CONFIG_TAP) += tap-drv.o
+tap-drv-y := tap.o tun_vnet.o
 obj-$(CONFIG_VETH) += veth.o
 obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
 obj-$(CONFIG_VXLAN) += vxlan/
diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index 7ee2e9ee2a89..4f3cc3b2e3c6 100644
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -26,74 +26,9 @@ 
 #include <linux/virtio_net.h>
 #include <linux/skb_array.h>
 
-#define TAP_IFFEATURES (IFF_VNET_HDR | IFF_MULTI_QUEUE)
-
-#define TAP_VNET_LE 0x80000000
-#define TAP_VNET_BE 0x40000000
-
-#ifdef CONFIG_TUN_VNET_CROSS_LE
-static inline bool tap_legacy_is_little_endian(struct tap_queue *q)
-{
-	return q->flags & TAP_VNET_BE ? false :
-		virtio_legacy_is_little_endian();
-}
-
-static long tap_get_vnet_be(struct tap_queue *q, int __user *sp)
-{
-	int s = !!(q->flags & TAP_VNET_BE);
-
-	if (put_user(s, sp))
-		return -EFAULT;
-
-	return 0;
-}
-
-static long tap_set_vnet_be(struct tap_queue *q, int __user *sp)
-{
-	int s;
-
-	if (get_user(s, sp))
-		return -EFAULT;
-
-	if (s)
-		q->flags |= TAP_VNET_BE;
-	else
-		q->flags &= ~TAP_VNET_BE;
-
-	return 0;
-}
-#else
-static inline bool tap_legacy_is_little_endian(struct tap_queue *q)
-{
-	return virtio_legacy_is_little_endian();
-}
-
-static long tap_get_vnet_be(struct tap_queue *q, int __user *argp)
-{
-	return -EINVAL;
-}
-
-static long tap_set_vnet_be(struct tap_queue *q, int __user *argp)
-{
-	return -EINVAL;
-}
-#endif /* CONFIG_TUN_VNET_CROSS_LE */
-
-static inline bool tap_is_little_endian(struct tap_queue *q)
-{
-	return q->flags & TAP_VNET_LE ||
-		tap_legacy_is_little_endian(q);
-}
-
-static inline u16 tap16_to_cpu(struct tap_queue *q, __virtio16 val)
-{
-	return __virtio16_to_cpu(tap_is_little_endian(q), val);
-}
+#include "tun_vnet.h"
 
-static inline __virtio16 cpu_to_tap16(struct tap_queue *q, u16 val)
-{
-	return __cpu_to_virtio16(tap_is_little_endian(q), val);
-}
+#define TAP_IFFEATURES (IFF_VNET_HDR | IFF_MULTI_QUEUE)
 
 static struct proto tap_proto = {
 	.name = "tap",
@@ -655,25 +590,11 @@  static ssize_t tap_get_user(struct tap_queue *q, void *msg_control,
 	if (q->flags & IFF_VNET_HDR) {
 		vnet_hdr_len = READ_ONCE(q->vnet_hdr_sz);
 
-		err = -EINVAL;
-		if (iov_iter_count(from) < vnet_hdr_len)
-			goto err;
-
-		err = -EFAULT;
-		if (!copy_from_iter_full(&vnet_hdr, sizeof(vnet_hdr), from))
-			goto err;
-		iov_iter_advance(from, vnet_hdr_len - sizeof(vnet_hdr));
-		if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
-		     tap16_to_cpu(q, vnet_hdr.csum_start) +
-		     tap16_to_cpu(q, vnet_hdr.csum_offset) + 2 >
-			     tap16_to_cpu(q, vnet_hdr.hdr_len))
-			vnet_hdr.hdr_len = cpu_to_tap16(q,
-				 tap16_to_cpu(q, vnet_hdr.csum_start) +
-				 tap16_to_cpu(q, vnet_hdr.csum_offset) + 2);
-		err = -EINVAL;
-		if (tap16_to_cpu(q, vnet_hdr.hdr_len) > iov_iter_count(from))
+		hdr_len = tun_vnet_hdr_get(vnet_hdr_len, q->flags, from, &vnet_hdr);
+		if (hdr_len < 0) {
+			err = hdr_len;
 			goto err;
-		hdr_len = tap16_to_cpu(q, vnet_hdr.hdr_len);
+		}
 	}
 
 	len = iov_iter_count(from);
@@ -731,8 +652,7 @@  static ssize_t tap_get_user(struct tap_queue *q, void *msg_control,
 	skb->dev = tap->dev;
 
 	if (vnet_hdr_len) {
-		err = virtio_net_hdr_to_skb(skb, &vnet_hdr,
-					    tap_is_little_endian(q));
+		err = tun_vnet_hdr_to_skb(q->flags, skb, &vnet_hdr);
 		if (err) {
 			rcu_read_unlock();
 			drop_reason = SKB_DROP_REASON_DEV_HDR;
@@ -795,23 +715,17 @@  static ssize_t tap_put_user(struct tap_queue *q,
 	int total;
 
 	if (q->flags & IFF_VNET_HDR) {
-		int vlan_hlen = skb_vlan_tag_present(skb) ? VLAN_HLEN : 0;
 		struct virtio_net_hdr vnet_hdr;
 
 		vnet_hdr_len = READ_ONCE(q->vnet_hdr_sz);
-		if (iov_iter_count(iter) < vnet_hdr_len)
-			return -EINVAL;
 
-		if (virtio_net_hdr_from_skb(skb, &vnet_hdr,
-					    tap_is_little_endian(q), true,
-					    vlan_hlen))
-			BUG();
-
-		if (copy_to_iter(&vnet_hdr, sizeof(vnet_hdr), iter) !=
-		    sizeof(vnet_hdr))
-			return -EFAULT;
+		ret = tun_vnet_hdr_from_skb(q->flags, NULL, skb, &vnet_hdr);
+		if (ret)
+			return ret;
 
-		iov_iter_advance(iter, vnet_hdr_len - sizeof(vnet_hdr));
+		ret = tun_vnet_hdr_put(vnet_hdr_len, iter, &vnet_hdr);
+		if (ret)
+			return ret;
 	}
 	total = vnet_hdr_len;
 	total += skb->len;
@@ -1070,42 +984,6 @@  static long tap_ioctl(struct file *file, unsigned int cmd,
 		q->sk.sk_sndbuf = s;
 		return 0;
 
-	case TUNGETVNETHDRSZ:
-		s = q->vnet_hdr_sz;
-		if (put_user(s, sp))
-			return -EFAULT;
-		return 0;
-
-	case TUNSETVNETHDRSZ:
-		if (get_user(s, sp))
-			return -EFAULT;
-		if (s < (int)sizeof(struct virtio_net_hdr))
-			return -EINVAL;
-
-		q->vnet_hdr_sz = s;
-		return 0;
-
-	case TUNGETVNETLE:
-		s = !!(q->flags & TAP_VNET_LE);
-		if (put_user(s, sp))
-			return -EFAULT;
-		return 0;
-
-	case TUNSETVNETLE:
-		if (get_user(s, sp))
-			return -EFAULT;
-		if (s)
-			q->flags |= TAP_VNET_LE;
-		else
-			q->flags &= ~TAP_VNET_LE;
-		return 0;
-
-	case TUNGETVNETBE:
-		return tap_get_vnet_be(q, sp);
-
-	case TUNSETVNETBE:
-		return tap_set_vnet_be(q, sp);
-
 	case TUNSETOFFLOAD:
 		/* let the user check for future flags */
 		if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
@@ -1149,7 +1027,7 @@  static long tap_ioctl(struct file *file, unsigned int cmd,
 		return ret;
 
 	default:
-		return -EINVAL;
+		return tun_vnet_ioctl(&q->vnet_hdr_sz, &q->flags, cmd, sp);
 	}
 }
 
@@ -1196,7 +1074,7 @@  static int tap_get_user_xdp(struct tap_queue *q, struct xdp_buff *xdp)
 	skb->protocol = eth_hdr(skb)->h_proto;
 
 	if (vnet_hdr_len) {
-		err = virtio_net_hdr_to_skb(skb, gso, tap_is_little_endian(q));
+		err = tun_vnet_hdr_to_skb(q->flags, skb, gso);
 		if (err)
 			goto err_kfree;
 	}
diff --git a/drivers/net/tun_vnet.c b/drivers/net/tun_vnet.c
index 5a6cbfb6eed0..960a5fa5a332 100644
--- a/drivers/net/tun_vnet.c
+++ b/drivers/net/tun_vnet.c
@@ -104,6 +104,7 @@  long tun_vnet_ioctl(int *sz, unsigned int *flags,
 		return -EINVAL;
 	}
 }
+EXPORT_SYMBOL_GPL(tun_vnet_ioctl);
 
 int tun_vnet_hdr_get(int sz, unsigned int flags, struct iov_iter *from,
 		     struct virtio_net_hdr *hdr)
@@ -125,6 +126,7 @@  int tun_vnet_hdr_get(int sz, unsigned int flags, struct iov_iter *from,
 
 	return tun16_to_cpu(flags, hdr->hdr_len);
 }
+EXPORT_SYMBOL_GPL(tun_vnet_hdr_get);
 
 int tun_vnet_hdr_put(int sz, struct iov_iter *iter,
 		     const struct virtio_net_hdr *hdr)
@@ -139,12 +141,14 @@  int tun_vnet_hdr_put(int sz, struct iov_iter *iter,
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(tun_vnet_hdr_put);
 
 int tun_vnet_hdr_to_skb(unsigned int flags, struct sk_buff *skb,
 			const struct virtio_net_hdr *hdr)
 {
 	return virtio_net_hdr_to_skb(skb, hdr, tun_is_little_endian(flags));
 }
+EXPORT_SYMBOL_GPL(tun_vnet_hdr_to_skb);
 
 int tun_vnet_hdr_from_skb(unsigned int flags,
 			  const struct net_device *dev,
@@ -173,3 +177,4 @@  int tun_vnet_hdr_from_skb(unsigned int flags,
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(tun_vnet_hdr_from_skb);