Both tun and tap exposes the same set of virtio-net-related features. Unify their implementations to ease future changes.
Signed-off-by: Akihiko Odaki akihiko.odaki@daynix.com --- MAINTAINERS | 1 + drivers/net/Kconfig | 5 ++ drivers/net/Makefile | 1 + drivers/net/tap.c | 172 ++++++---------------------------------- drivers/net/tun.c | 208 ++++++++----------------------------------------- drivers/net/tun_vnet.c | 186 +++++++++++++++++++++++++++++++++++++++++++ drivers/net/tun_vnet.h | 24 ++++++ 7 files changed, 273 insertions(+), 324 deletions(-)
diff --git a/MAINTAINERS b/MAINTAINERS index 910305c11e8a..1be8a452d11f 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -23903,6 +23903,7 @@ F: Documentation/networking/tuntap.rst F: arch/um/os-Linux/drivers/ F: drivers/net/tap.c F: drivers/net/tun.c +F: drivers/net/tun_vnet.h
TURBOCHANNEL SUBSYSTEM M: "Maciej W. Rozycki" macro@orcam.me.uk diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig index 1fd5acdc73c6..255c8f9f1d7c 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 TUN_VNET help TUN/TAP provides packet reception and transmission for user space programs. It can be viewed as a simple Point-to-Point or Ethernet @@ -417,10 +418,14 @@ config TUN
config TAP tristate + select TUN_VNET help This option is selected by any driver implementing tap user space interface for a virtual interface to re-use core tap functionality.
+config TUN_VNET + tristate + config TUN_VNET_CROSS_LE bool "Support for cross-endian vnet headers on little-endian kernels" default n diff --git a/drivers/net/Makefile b/drivers/net/Makefile index 13743d0e83b5..bc1f193eccb1 100644 --- a/drivers/net/Makefile +++ b/drivers/net/Makefile @@ -30,6 +30,7 @@ obj-y += pcs/ obj-$(CONFIG_RIONET) += rionet.o obj-$(CONFIG_NET_TEAM) += team/ obj-$(CONFIG_TUN) += tun.o +obj-$(CONFIG_TUN_VNET) += tun_vnet.o obj-$(CONFIG_TAP) += tap.o obj-$(CONFIG_VETH) += veth.o obj-$(CONFIG_VIRTIO_NET) += virtio_net.o diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 5aa41d5f7765..60804855510b 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; -} +#include "tun_vnet.h"
-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); -} - -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", @@ -641,10 +576,10 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, struct sk_buff *skb; struct tap_dev *tap; unsigned long total_len = iov_iter_count(from); - unsigned long len = total_len; + unsigned long len; int err; struct virtio_net_hdr vnet_hdr = { 0 }; - int vnet_hdr_len = 0; + int hdr_len; int copylen = 0; int depth; bool zerocopy = false; @@ -652,38 +587,20 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, enum skb_drop_reason drop_reason;
if (q->flags & IFF_VNET_HDR) { - vnet_hdr_len = READ_ONCE(q->vnet_hdr_sz); - - err = -EINVAL; - if (len < vnet_hdr_len) - goto err; - len -= vnet_hdr_len; - - 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) > len) + hdr_len = tun_vnet_hdr_get(READ_ONCE(q->vnet_hdr_sz), q->flags, from, &vnet_hdr); + if (hdr_len < 0) { + err = hdr_len; goto err; + } + } else { + hdr_len = 0; }
- err = -EINVAL; - if (unlikely(len < ETH_HLEN)) - goto err; - + len = iov_iter_count(from); if (msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) { struct iov_iter i;
- copylen = vnet_hdr.hdr_len ? - tap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN; + copylen = hdr_len ? hdr_len : GOODCOPY_LEN; if (copylen > good_linear) copylen = good_linear; else if (copylen < ETH_HLEN) @@ -697,7 +614,7 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control,
if (!zerocopy) { copylen = len; - linear = tap16_to_cpu(q, vnet_hdr.hdr_len); + linear = hdr_len; if (linear > good_linear) linear = good_linear; else if (linear < ETH_HLEN) @@ -732,9 +649,8 @@ 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)); + if (q->flags & IFF_VNET_HDR) { + err = tun_vnet_hdr_to_skb(q->flags, skb, &vnet_hdr); if (err) { rcu_read_unlock(); drop_reason = SKB_DROP_REASON_DEV_HDR; @@ -797,23 +713,17 @@ 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 < 0) + goto done;
- iov_iter_advance(iter, vnet_hdr_len - sizeof(vnet_hdr)); + ret = tun_vnet_hdr_put(vnet_hdr_len, iter, &vnet_hdr); + if (ret < 0) + goto done; } total = vnet_hdr_len; total += skb->len; @@ -1072,42 +982,6 @@ 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 | @@ -1151,7 +1025,7 @@ 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); } }
@@ -1198,7 +1072,7 @@ 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.c b/drivers/net/tun.c index e816aaba8e5f..dbf0dee92e93 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -83,6 +83,8 @@ #include <linux/uaccess.h> #include <linux/proc_fs.h>
+#include "tun_vnet.h" + static void tun_default_link_ksettings(struct net_device *dev, struct ethtool_link_ksettings *cmd);
@@ -94,9 +96,6 @@ static void tun_default_link_ksettings(struct net_device *dev, * overload it to mean fasync when stored there. */ #define TUN_FASYNC IFF_ATTACH_QUEUE -/* High bits in flags field are unused. */ -#define TUN_VNET_LE 0x80000000 -#define TUN_VNET_BE 0x40000000
#define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \ IFF_MULTI_QUEUE | IFF_NAPI | IFF_NAPI_FRAGS) @@ -298,70 +297,6 @@ static bool tun_napi_frags_enabled(const struct tun_file *tfile) return tfile->napi_frags_enabled; }
-#ifdef CONFIG_TUN_VNET_CROSS_LE -static inline bool tun_legacy_is_little_endian(struct tun_struct *tun) -{ - return tun->flags & TUN_VNET_BE ? false : - virtio_legacy_is_little_endian(); -} - -static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp) -{ - int be = !!(tun->flags & TUN_VNET_BE); - - if (put_user(be, argp)) - return -EFAULT; - - return 0; -} - -static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp) -{ - int be; - - if (get_user(be, argp)) - return -EFAULT; - - if (be) - tun->flags |= TUN_VNET_BE; - else - tun->flags &= ~TUN_VNET_BE; - - return 0; -} -#else -static inline bool tun_legacy_is_little_endian(struct tun_struct *tun) -{ - return virtio_legacy_is_little_endian(); -} - -static long tun_get_vnet_be(struct tun_struct *tun, int __user *argp) -{ - return -EINVAL; -} - -static long tun_set_vnet_be(struct tun_struct *tun, int __user *argp) -{ - return -EINVAL; -} -#endif /* CONFIG_TUN_VNET_CROSS_LE */ - -static inline bool tun_is_little_endian(struct tun_struct *tun) -{ - return tun->flags & TUN_VNET_LE || - tun_legacy_is_little_endian(tun); -} - -static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val) -{ - return __virtio16_to_cpu(tun_is_little_endian(tun), val); -} - -static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val) -{ - return __cpu_to_virtio16(tun_is_little_endian(tun), val); -} - static inline u32 tun_hashfn(u32 rxhash) { return rxhash & TUN_MASK_FLOW_ENTRIES; @@ -1752,8 +1687,9 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) }; struct sk_buff *skb; size_t total_len = iov_iter_count(from); - size_t len = total_len, align = tun->align, linear; + size_t len, align = tun->align, linear; struct virtio_net_hdr gso = { 0 }; + int hdr_len; int good_linear; int copylen; bool zerocopy = false; @@ -1764,37 +1700,25 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, enum skb_drop_reason drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
if (!(tun->flags & IFF_NO_PI)) { - if (len < sizeof(pi)) + if (iov_iter_count(from) < sizeof(pi)) return -EINVAL; - len -= sizeof(pi);
if (!copy_from_iter_full(&pi, sizeof(pi), from)) return -EFAULT; }
if (tun->flags & IFF_VNET_HDR) { - int vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz); - - if (len < vnet_hdr_sz) - return -EINVAL; - len -= vnet_hdr_sz; - - if (!copy_from_iter_full(&gso, sizeof(gso), from)) - return -EFAULT; - - if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && - tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len)) - gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2); - - if (tun16_to_cpu(tun, gso.hdr_len) > len) - return -EINVAL; - iov_iter_advance(from, vnet_hdr_sz - sizeof(gso)); + hdr_len = tun_vnet_hdr_get(READ_ONCE(tun->vnet_hdr_sz), tun->flags, from, &gso); + if (hdr_len < 0) + return hdr_len; + } else { + hdr_len = 0; }
+ len = iov_iter_count(from); if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) { align += NET_IP_ALIGN; - if (unlikely(len < ETH_HLEN || - (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN))) + if (unlikely(len < ETH_HLEN || (hdr_len && hdr_len < ETH_HLEN))) return -EINVAL; }
@@ -1807,7 +1731,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, * enough room for skb expand head in case it is used. * The rest of the buffer is mapped from userspace. */ - copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN; + copylen = hdr_len ? hdr_len : GOODCOPY_LEN; if (copylen > good_linear) copylen = good_linear; linear = copylen; @@ -1830,10 +1754,10 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, } else { if (!zerocopy) { copylen = len; - if (tun16_to_cpu(tun, gso.hdr_len) > good_linear) + if (hdr_len > good_linear) linear = good_linear; else - linear = tun16_to_cpu(tun, gso.hdr_len); + linear = hdr_len; }
if (frags) { @@ -1868,7 +1792,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, } }
- if (virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun))) { + if (tun_vnet_hdr_to_skb(tun->flags, skb, &gso)) { atomic_long_inc(&tun->rx_frame_errors); err = -EINVAL; goto free_skb; @@ -2061,29 +1985,27 @@ static ssize_t tun_put_user_xdp(struct tun_struct *tun, struct xdp_frame *xdp_frame, struct iov_iter *iter) { + int ret; int vnet_hdr_sz = 0; size_t size = xdp_frame->len; - size_t ret; + size_t total;
if (tun->flags & IFF_VNET_HDR) { struct virtio_net_hdr gso = { 0 };
vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz); - if (unlikely(iov_iter_count(iter) < vnet_hdr_sz)) - return -EINVAL; - if (unlikely(copy_to_iter(&gso, sizeof(gso), iter) != - sizeof(gso))) - return -EFAULT; - iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso)); + ret = tun_vnet_hdr_put(vnet_hdr_sz, iter, &gso); + if (ret < 0) + return ret; }
- ret = copy_to_iter(xdp_frame->data, size, iter) + vnet_hdr_sz; + total = copy_to_iter(xdp_frame->data, size, iter) + vnet_hdr_sz;
preempt_disable(); - dev_sw_netstats_tx_add(tun->dev, 1, ret); + dev_sw_netstats_tx_add(tun->dev, 1, total); preempt_enable();
- return ret; + return total; }
/* Put packet to the user space buffer */ @@ -2097,6 +2019,7 @@ static ssize_t tun_put_user(struct tun_struct *tun, int vlan_offset = 0; int vlan_hlen = 0; int vnet_hdr_sz = 0; + int ret;
if (skb_vlan_tag_present(skb)) vlan_hlen = VLAN_HLEN; @@ -2123,31 +2046,13 @@ static ssize_t tun_put_user(struct tun_struct *tun, if (vnet_hdr_sz) { struct virtio_net_hdr gso;
- if (iov_iter_count(iter) < vnet_hdr_sz) - return -EINVAL; - - if (virtio_net_hdr_from_skb(skb, &gso, - tun_is_little_endian(tun), true, - vlan_hlen)) { - struct skb_shared_info *sinfo = skb_shinfo(skb); - - if (net_ratelimit()) { - netdev_err(tun->dev, "unexpected GSO type: 0x%x, gso_size %d, hdr_len %d\n", - sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size), - tun16_to_cpu(tun, gso.hdr_len)); - print_hex_dump(KERN_ERR, "tun: ", - DUMP_PREFIX_NONE, - 16, 1, skb->head, - min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true); - } - WARN_ON_ONCE(1); - return -EINVAL; - } - - if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso)) - return -EFAULT; + ret = tun_vnet_hdr_from_skb(tun->flags, tun->dev, skb, &gso); + if (ret < 0) + goto done;
- iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso)); + ret = tun_vnet_hdr_put(vnet_hdr_sz, iter, &gso); + if (ret < 0) + goto done; }
if (vlan_hlen) { @@ -2507,7 +2412,7 @@ static int tun_xdp_one(struct tun_struct *tun, skb_reserve(skb, xdp->data - xdp->data_hard_start); skb_put(skb, xdp->data_end - xdp->data);
- if (virtio_net_hdr_to_skb(skb, gso, tun_is_little_endian(tun))) { + if (tun_vnet_hdr_to_skb(tun->flags, skb, gso)) { atomic_long_inc(&tun->rx_frame_errors); kfree_skb(skb); ret = -EINVAL; @@ -3091,8 +2996,6 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, kgid_t group; int ifindex; int sndbuf; - int vnet_hdr_sz; - int le; int ret; bool do_notify = false;
@@ -3299,50 +3202,6 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, tun_set_sndbuf(tun); break;
- case TUNGETVNETHDRSZ: - vnet_hdr_sz = tun->vnet_hdr_sz; - if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz))) - ret = -EFAULT; - break; - - case TUNSETVNETHDRSZ: - if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) { - ret = -EFAULT; - break; - } - if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) { - ret = -EINVAL; - break; - } - - tun->vnet_hdr_sz = vnet_hdr_sz; - break; - - case TUNGETVNETLE: - le = !!(tun->flags & TUN_VNET_LE); - if (put_user(le, (int __user *)argp)) - ret = -EFAULT; - break; - - case TUNSETVNETLE: - if (get_user(le, (int __user *)argp)) { - ret = -EFAULT; - break; - } - if (le) - tun->flags |= TUN_VNET_LE; - else - tun->flags &= ~TUN_VNET_LE; - break; - - case TUNGETVNETBE: - ret = tun_get_vnet_be(tun, argp); - break; - - case TUNSETVNETBE: - ret = tun_set_vnet_be(tun, argp); - break; - case TUNATTACHFILTER: /* Can be set only for TAPs */ ret = -EINVAL; @@ -3398,8 +3257,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, break;
default: - ret = -EINVAL; - break; + ret = tun_vnet_ioctl(&tun->vnet_hdr_sz, &tun->flags, cmd, argp); }
if (do_notify) diff --git a/drivers/net/tun_vnet.c b/drivers/net/tun_vnet.c new file mode 100644 index 000000000000..fe842df9e9ef --- /dev/null +++ b/drivers/net/tun_vnet.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +#include "tun_vnet.h" + +/* High bits in flags field are unused. */ +#define TUN_VNET_LE 0x80000000 +#define TUN_VNET_BE 0x40000000 + +static bool tun_vnet_legacy_is_little_endian(unsigned int flags) +{ + return !(IS_ENABLED(CONFIG_TUN_VNET_CROSS_LE) && (flags & TUN_VNET_BE)) && + virtio_legacy_is_little_endian(); +} + +static long tun_vnet_get_be(int flags, int __user *sp) +{ + int s = !!(flags & TUN_VNET_BE); + + if (!IS_ENABLED(CONFIG_TUN_VNET_CROSS_LE)) + return -EINVAL; + + if (put_user(s, sp)) + return -EFAULT; + + return 0; +} + +static long tun_vnet_set_be(int *flags, int __user *sp) +{ + int s; + + if (!IS_ENABLED(CONFIG_TUN_VNET_CROSS_LE)) + return -EINVAL; + + if (get_user(s, sp)) + return -EFAULT; + + if (s) + *flags |= TUN_VNET_BE; + else + *flags &= ~TUN_VNET_BE; + + return 0; +} + +static bool tun_vnet_is_little_endian(unsigned int flags) +{ + return flags & TUN_VNET_LE || tun_vnet_legacy_is_little_endian(flags); +} + +static u16 tun_vnet16_to_cpu(unsigned int flags, __virtio16 val) +{ + return __virtio16_to_cpu(tun_vnet_is_little_endian(flags), val); +} + +static __virtio16 cpu_to_tun_vnet16(unsigned int flags, u16 val) +{ + return __cpu_to_virtio16(tun_vnet_is_little_endian(flags), val); +} + +long tun_vnet_ioctl(int *sz, unsigned int *flags, + unsigned int cmd, int __user *sp) +{ + int s; + + switch (cmd) { + case TUNGETVNETHDRSZ: + s = *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; + + *sz = s; + return 0; + + case TUNGETVNETLE: + s = !!(*flags & TUN_VNET_LE); + if (put_user(s, sp)) + return -EFAULT; + return 0; + + case TUNSETVNETLE: + if (get_user(s, sp)) + return -EFAULT; + if (s) + *flags |= TUN_VNET_LE; + else + *flags &= ~TUN_VNET_LE; + return 0; + + case TUNGETVNETBE: + return tun_vnet_get_be(*flags, sp); + + case TUNSETVNETBE: + return tun_vnet_set_be(flags, sp); + + default: + 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) +{ + if (iov_iter_count(from) < sz) + return -EINVAL; + + if (!copy_from_iter_full(hdr, sizeof(*hdr), from)) + return -EFAULT; + + iov_iter_advance(from, sz - sizeof(*hdr)); + if ((hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && + tun_vnet16_to_cpu(flags, hdr->csum_start) + + tun_vnet16_to_cpu(flags, hdr->csum_offset) + 2 > + tun_vnet16_to_cpu(flags, hdr->hdr_len)) + hdr->hdr_len = cpu_to_tun_vnet16(flags, + tun_vnet16_to_cpu(flags, hdr->csum_start) + + tun_vnet16_to_cpu(flags, hdr->csum_offset) + 2); + if (tun_vnet16_to_cpu(flags, hdr->hdr_len) > iov_iter_count(from)) + return -EINVAL; + + return tun_vnet16_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) +{ + if (iov_iter_count(iter) < sz) + return -EINVAL; + + if (copy_to_iter(hdr, sizeof(*hdr), iter) != sizeof(*hdr)) + return -EFAULT; + + iov_iter_advance(iter, sz - sizeof(*hdr)); + + 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_vnet_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, + const struct sk_buff *skb, + struct virtio_net_hdr *hdr) +{ + int vlan_hlen = skb_vlan_tag_present(skb) ? VLAN_HLEN : 0; + + if (virtio_net_hdr_from_skb(skb, hdr, + tun_vnet_is_little_endian(flags), true, + vlan_hlen)) { + struct skb_shared_info *sinfo = skb_shinfo(skb); + + if (net_ratelimit()) { + netdev_err(dev, "unexpected GSO type: 0x%x, gso_size %d, hdr_len %d\n", + sinfo->gso_type, tun_vnet16_to_cpu(flags, hdr->gso_size), + tun_vnet16_to_cpu(flags, hdr->hdr_len)); + print_hex_dump(KERN_ERR, "tun: ", + DUMP_PREFIX_NONE, + 16, 1, skb->head, + min(tun_vnet16_to_cpu(flags, hdr->hdr_len), 64), true); + } + WARN_ON_ONCE(1); + return -EINVAL; + } + + return 0; +} +EXPORT_SYMBOL_GPL(tun_vnet_hdr_from_skb); + +MODULE_DESCRIPTION("Common library for drivers implementing TUN/TAP's virtio-related features"); +MODULE_AUTHOR("Max Krasnyansky maxk@qualcomm.com"); +MODULE_AUTHOR("Arnd Bergmann arnd@arndb.de"); +MODULE_AUTHOR("Sainath Grandhi sainath.grandhi@intel.com"); +MODULE_LICENSE("GPL"); diff --git a/drivers/net/tun_vnet.h b/drivers/net/tun_vnet.h new file mode 100644 index 000000000000..2dfdbe92bb24 --- /dev/null +++ b/drivers/net/tun_vnet.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef TUN_VNET_H +#define TUN_VNET_H + +#include <linux/if_tun.h> +#include <linux/virtio_net.h> + +long tun_vnet_ioctl(int *sz, unsigned int *flags, + unsigned int cmd, int __user *sp); + +int tun_vnet_hdr_get(int sz, unsigned int flags, struct iov_iter *from, + struct virtio_net_hdr *hdr); + +int tun_vnet_hdr_put(int sz, struct iov_iter *iter, + const struct virtio_net_hdr *hdr); + +int tun_vnet_hdr_to_skb(unsigned int flags, struct sk_buff *skb, + const struct virtio_net_hdr *hdr); + +int tun_vnet_hdr_from_skb(unsigned int flags, const struct net_device *dev, + const struct sk_buff *skb, + struct virtio_net_hdr *hdr); + +#endif /* TUN_VNET_H */