| Message ID | 20250116-tun-v3-9-c6b2871e97f7@daynix.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | tun: Unify vnet implementation | expand |
Akihiko Odaki wrote: > 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 --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-$(CONFIG_TUN) += tun.o Is reversing the previous changes to tun.ko intentional? Perhaps the previous approach with a new CONFIG_TUN_VNET is preferable over this. In particular over making TUN select TAP, a new dependency. > +obj-$(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-$(CONFIG_VXLAN) += vxlan/
On 2025/01/17 18:23, Willem de Bruijn wrote: > Akihiko Odaki wrote: >> tun and tap implements the same vnet-related features so reuse the code. >> >> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> >> --- >> drivers/net/Kconfig | 1 + >> drivers/net/Makefile | 6 +- >> drivers/net/tap.c | 152 +++++-------------------------------------------- >> drivers/net/tun_vnet.c | 5 ++ >> 4 files changed, 24 insertions(+), 140 deletions(-) >> >> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig >> index 1fd5acdc73c6..c420418473fc 100644 >> --- a/drivers/net/Kconfig >> +++ b/drivers/net/Kconfig >> @@ -395,6 +395,7 @@ config TUN >> tristate "Universal TUN/TAP device driver support" >> depends on INET >> select CRC32 >> + select TAP >> help >> TUN/TAP provides packet reception and transmission for user space >> programs. It can be viewed as a simple Point-to-Point or Ethernet >> diff --git a/drivers/net/Makefile b/drivers/net/Makefile >> index bb8eb3053772..2275309a97ee 100644 >> --- a/drivers/net/Makefile >> +++ b/drivers/net/Makefile >> @@ -29,9 +29,9 @@ obj-y += mdio/ >> obj-y += pcs/ >> obj-$(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 > > Is reversing the previous changes to tun.ko intentional? > > Perhaps the previous approach with a new CONFIG_TUN_VNET is preferable > over this. In particular over making TUN select TAP, a new dependency. Jason, you also commented about CONFIG_TUN_VNET for the previous version. Do you prefer the old approach, or the new one? (Or if you have another idea, please tell me.) > >> +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/
On Fri, Jan 17, 2025 at 6:35 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote: > > On 2025/01/17 18:23, Willem de Bruijn wrote: > > Akihiko Odaki wrote: > >> 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 --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-$(CONFIG_TUN) += tun.o > > > > Is reversing the previous changes to tun.ko intentional? > > > > Perhaps the previous approach with a new CONFIG_TUN_VNET is preferable > > over this. In particular over making TUN select TAP, a new dependency. > > Jason, you also commented about CONFIG_TUN_VNET for the previous > version. Do you prefer the old approach, or the new one? (Or if you have > another idea, please tell me.) Ideally, if we can make TUN select TAP that would be better. But there are some subtle differences in the multi queue implementation. We will end up with some useless code for TUN unless we can unify the multi queue logic. It might not be worth it to change the TUN's multi queue logic so having a new file seems to be better. Thanks > > > > >> +obj-$(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-$(CONFIG_VXLAN) += vxlan/ >
On Mon, Jan 20, 2025 at 1:37 AM Jason Wang <jasowang@redhat.com> wrote: > > On Fri, Jan 17, 2025 at 6:35 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote: > > > > On 2025/01/17 18:23, Willem de Bruijn wrote: > > > Akihiko Odaki wrote: > > >> tun and tap implements the same vnet-related features so reuse the code. > > >> > > >> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com> > > >> --- > > >> drivers/net/Kconfig | 1 + > > >> drivers/net/Makefile | 6 +- > > >> drivers/net/tap.c | 152 +++++-------------------------------------------- > > >> drivers/net/tun_vnet.c | 5 ++ > > >> 4 files changed, 24 insertions(+), 140 deletions(-) > > >> > > >> diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig > > >> index 1fd5acdc73c6..c420418473fc 100644 > > >> --- a/drivers/net/Kconfig > > >> +++ b/drivers/net/Kconfig > > >> @@ -395,6 +395,7 @@ config TUN > > >> tristate "Universal TUN/TAP device driver support" > > >> depends on INET > > >> select CRC32 > > >> + select TAP > > >> help > > >> TUN/TAP provides packet reception and transmission for user space > > >> programs. It can be viewed as a simple Point-to-Point or Ethernet > > >> diff --git a/drivers/net/Makefile b/drivers/net/Makefile > > >> index bb8eb3053772..2275309a97ee 100644 > > >> --- a/drivers/net/Makefile > > >> +++ b/drivers/net/Makefile > > >> @@ -29,9 +29,9 @@ obj-y += mdio/ > > >> obj-y += pcs/ > > >> obj-$(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 > > > > > > Is reversing the previous changes to tun.ko intentional? > > > > > > Perhaps the previous approach with a new CONFIG_TUN_VNET is preferable > > > over this. In particular over making TUN select TAP, a new dependency. > > > > Jason, you also commented about CONFIG_TUN_VNET for the previous > > version. Do you prefer the old approach, or the new one? (Or if you have > > another idea, please tell me.) > > Ideally, if we can make TUN select TAP that would be better. But there > are some subtle differences in the multi queue implementation. We will > end up with some useless code for TUN unless we can unify the multi > queue logic. It might not be worth it to change the TUN's multi queue > logic so having a new file seems to be better. +1 on deduplicating further. But this series is complex enough. Let's not expand that. The latest approach with a separate .o file may have some performance cost by converting likely inlined code into real function calls. Another option is to move it all into tun_vnet.h. That also resolves the Makefile issues.
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);
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(-)