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path: root/drivers/net/tun.c
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Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c310
1 files changed, 268 insertions, 42 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index c1685a6d7883..6bb1e604aadd 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -75,6 +75,7 @@
#include <linux/skb_array.h>
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
+#include <linux/mutex.h>
#include <linux/uaccess.h>
@@ -121,7 +122,8 @@ do { \
#define TUN_VNET_BE 0x40000000
#define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
- IFF_MULTI_QUEUE)
+ IFF_MULTI_QUEUE | IFF_NAPI | IFF_NAPI_FRAGS)
+
#define GOODCOPY_LEN 128
#define FLT_EXACT_COUNT 8
@@ -172,6 +174,9 @@ struct tun_file {
u16 queue_index;
unsigned int ifindex;
};
+ struct napi_struct napi;
+ bool napi_enabled;
+ struct mutex napi_mutex; /* Protects access to the above napi */
struct list_head next;
struct tun_struct *detached;
struct skb_array tx_array;
@@ -229,6 +234,75 @@ struct tun_struct {
struct bpf_prog __rcu *xdp_prog;
};
+static int tun_napi_receive(struct napi_struct *napi, int budget)
+{
+ struct tun_file *tfile = container_of(napi, struct tun_file, napi);
+ struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
+ struct sk_buff_head process_queue;
+ struct sk_buff *skb;
+ int received = 0;
+
+ __skb_queue_head_init(&process_queue);
+
+ spin_lock(&queue->lock);
+ skb_queue_splice_tail_init(queue, &process_queue);
+ spin_unlock(&queue->lock);
+
+ while (received < budget && (skb = __skb_dequeue(&process_queue))) {
+ napi_gro_receive(napi, skb);
+ ++received;
+ }
+
+ if (!skb_queue_empty(&process_queue)) {
+ spin_lock(&queue->lock);
+ skb_queue_splice(&process_queue, queue);
+ spin_unlock(&queue->lock);
+ }
+
+ return received;
+}
+
+static int tun_napi_poll(struct napi_struct *napi, int budget)
+{
+ unsigned int received;
+
+ received = tun_napi_receive(napi, budget);
+
+ if (received < budget)
+ napi_complete_done(napi, received);
+
+ return received;
+}
+
+static void tun_napi_init(struct tun_struct *tun, struct tun_file *tfile,
+ bool napi_en)
+{
+ tfile->napi_enabled = napi_en;
+ if (napi_en) {
+ netif_napi_add(tun->dev, &tfile->napi, tun_napi_poll,
+ NAPI_POLL_WEIGHT);
+ napi_enable(&tfile->napi);
+ mutex_init(&tfile->napi_mutex);
+ }
+}
+
+static void tun_napi_disable(struct tun_struct *tun, struct tun_file *tfile)
+{
+ if (tfile->napi_enabled)
+ napi_disable(&tfile->napi);
+}
+
+static void tun_napi_del(struct tun_struct *tun, struct tun_file *tfile)
+{
+ if (tfile->napi_enabled)
+ netif_napi_del(&tfile->napi);
+}
+
+static bool tun_napi_frags_enabled(const struct tun_struct *tun)
+{
+ return READ_ONCE(tun->flags) & IFF_NAPI_FRAGS;
+}
+
#ifdef CONFIG_TUN_VNET_CROSS_LE
static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
{
@@ -380,25 +454,28 @@ static void tun_flow_cleanup(unsigned long data)
tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
- spin_lock_bh(&tun->lock);
+ spin_lock(&tun->lock);
for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++) {
struct tun_flow_entry *e;
struct hlist_node *n;
hlist_for_each_entry_safe(e, n, &tun->flows[i], hash_link) {
unsigned long this_timer;
- count++;
+
this_timer = e->updated + delay;
- if (time_before_eq(this_timer, jiffies))
+ if (time_before_eq(this_timer, jiffies)) {
tun_flow_delete(tun, e);
- else if (time_before(this_timer, next_timer))
+ continue;
+ }
+ count++;
+ if (time_before(this_timer, next_timer))
next_timer = this_timer;
}
}
if (count)
mod_timer(&tun->flow_gc_timer, round_jiffies_up(next_timer));
- spin_unlock_bh(&tun->lock);
+ spin_unlock(&tun->lock);
}
static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
@@ -541,6 +618,11 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
tun = rtnl_dereference(tfile->tun);
+ if (tun && clean) {
+ tun_napi_disable(tun, tfile);
+ tun_napi_del(tun, tfile);
+ }
+
if (tun && !tfile->detached) {
u16 index = tfile->queue_index;
BUG_ON(index >= tun->numqueues);
@@ -598,6 +680,7 @@ static void tun_detach_all(struct net_device *dev)
for (i = 0; i < n; i++) {
tfile = rtnl_dereference(tun->tfiles[i]);
BUG_ON(!tfile);
+ tun_napi_disable(tun, tfile);
tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
tfile->socket.sk->sk_data_ready(tfile->socket.sk);
RCU_INIT_POINTER(tfile->tun, NULL);
@@ -613,6 +696,7 @@ static void tun_detach_all(struct net_device *dev)
synchronize_net();
for (i = 0; i < n; i++) {
tfile = rtnl_dereference(tun->tfiles[i]);
+ tun_napi_del(tun, tfile);
/* Drop read queue */
tun_queue_purge(tfile);
sock_put(&tfile->sk);
@@ -631,7 +715,8 @@ static void tun_detach_all(struct net_device *dev)
module_put(THIS_MODULE);
}
-static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filter)
+static int tun_attach(struct tun_struct *tun, struct file *file,
+ bool skip_filter, bool napi)
{
struct tun_file *tfile = file->private_data;
struct net_device *dev = tun->dev;
@@ -677,10 +762,12 @@ static int tun_attach(struct tun_struct *tun, struct file *file, bool skip_filte
rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
tun->numqueues++;
- if (tfile->detached)
+ if (tfile->detached) {
tun_enable_queue(tfile);
- else
+ } else {
sock_hold(&tfile->sk);
+ tun_napi_init(tun, tfile, napi);
+ }
tun_set_real_num_queues(tun);
@@ -692,7 +779,7 @@ out:
return err;
}
-static struct tun_struct *__tun_get(struct tun_file *tfile)
+static struct tun_struct *tun_get(struct tun_file *tfile)
{
struct tun_struct *tun;
@@ -705,11 +792,6 @@ static struct tun_struct *__tun_get(struct tun_file *tfile)
return tun;
}
-static struct tun_struct *tun_get(struct file *file)
-{
- return __tun_get(file->private_data);
-}
-
static void tun_put(struct tun_struct *tun)
{
dev_put(tun->dev);
@@ -956,13 +1038,33 @@ static void tun_poll_controller(struct net_device *dev)
* Tun only receives frames when:
* 1) the char device endpoint gets data from user space
* 2) the tun socket gets a sendmsg call from user space
- * Since both of those are synchronous operations, we are guaranteed
- * never to have pending data when we poll for it
- * so there is nothing to do here but return.
+ * If NAPI is not enabled, since both of those are synchronous
+ * operations, we are guaranteed never to have pending data when we poll
+ * for it so there is nothing to do here but return.
* We need this though so netpoll recognizes us as an interface that
* supports polling, which enables bridge devices in virt setups to
* still use netconsole
+ * If NAPI is enabled, however, we need to schedule polling for all
+ * queues unless we are using napi_gro_frags(), which we call in
+ * process context and not in NAPI context.
*/
+ struct tun_struct *tun = netdev_priv(dev);
+
+ if (tun->flags & IFF_NAPI) {
+ struct tun_file *tfile;
+ int i;
+
+ if (tun_napi_frags_enabled(tun))
+ return;
+
+ rcu_read_lock();
+ for (i = 0; i < tun->numqueues; i++) {
+ tfile = rcu_dereference(tun->tfiles[i]);
+ if (tfile->napi_enabled)
+ napi_schedule(&tfile->napi);
+ }
+ rcu_read_unlock();
+ }
return;
}
#endif
@@ -1039,7 +1141,7 @@ static u32 tun_xdp_query(struct net_device *dev)
return 0;
}
-static int tun_xdp(struct net_device *dev, struct netdev_xdp *xdp)
+static int tun_xdp(struct net_device *dev, struct netdev_bpf *xdp)
{
switch (xdp->command) {
case XDP_SETUP_PROG:
@@ -1083,7 +1185,7 @@ static const struct net_device_ops tap_netdev_ops = {
.ndo_features_check = passthru_features_check,
.ndo_set_rx_headroom = tun_set_headroom,
.ndo_get_stats64 = tun_net_get_stats64,
- .ndo_xdp = tun_xdp,
+ .ndo_bpf = tun_xdp,
};
static void tun_flow_init(struct tun_struct *tun)
@@ -1095,8 +1197,6 @@ static void tun_flow_init(struct tun_struct *tun)
tun->ageing_time = TUN_FLOW_EXPIRE;
setup_timer(&tun->flow_gc_timer, tun_flow_cleanup, (unsigned long)tun);
- mod_timer(&tun->flow_gc_timer,
- round_jiffies_up(jiffies + tun->ageing_time));
}
static void tun_flow_uninit(struct tun_struct *tun)
@@ -1149,7 +1249,7 @@ static void tun_net_init(struct net_device *dev)
static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
{
struct tun_file *tfile = file->private_data;
- struct tun_struct *tun = __tun_get(tfile);
+ struct tun_struct *tun = tun_get(tfile);
struct sock *sk;
unsigned int mask = 0;
@@ -1178,6 +1278,64 @@ static unsigned int tun_chr_poll(struct file *file, poll_table *wait)
return mask;
}
+static struct sk_buff *tun_napi_alloc_frags(struct tun_file *tfile,
+ size_t len,
+ const struct iov_iter *it)
+{
+ struct sk_buff *skb;
+ size_t linear;
+ int err;
+ int i;
+
+ if (it->nr_segs > MAX_SKB_FRAGS + 1)
+ return ERR_PTR(-ENOMEM);
+
+ local_bh_disable();
+ skb = napi_get_frags(&tfile->napi);
+ local_bh_enable();
+ if (!skb)
+ return ERR_PTR(-ENOMEM);
+
+ linear = iov_iter_single_seg_count(it);
+ err = __skb_grow(skb, linear);
+ if (err)
+ goto free;
+
+ skb->len = len;
+ skb->data_len = len - linear;
+ skb->truesize += skb->data_len;
+
+ for (i = 1; i < it->nr_segs; i++) {
+ size_t fragsz = it->iov[i].iov_len;
+ unsigned long offset;
+ struct page *page;
+ void *data;
+
+ if (fragsz == 0 || fragsz > PAGE_SIZE) {
+ err = -EINVAL;
+ goto free;
+ }
+
+ local_bh_disable();
+ data = napi_alloc_frag(fragsz);
+ local_bh_enable();
+ if (!data) {
+ err = -ENOMEM;
+ goto free;
+ }
+
+ page = virt_to_head_page(data);
+ offset = data - page_address(page);
+ skb_fill_page_desc(skb, i - 1, page, offset, fragsz);
+ }
+
+ return skb;
+free:
+ /* frees skb and all frags allocated with napi_alloc_frag() */
+ napi_free_frags(&tfile->napi);
+ return ERR_PTR(err);
+}
+
/* prepad is the amount to reserve at front. len is length after that.
* linear is a hint as to how much to copy (usually headers). */
static struct sk_buff *tun_alloc_skb(struct tun_file *tfile,
@@ -1315,6 +1473,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun,
xdp.data_hard_start = buf;
xdp.data = buf + pad;
+ xdp_set_data_meta_invalid(&xdp);
xdp.data_end = xdp.data + len;
orig_data = xdp.data;
act = bpf_prog_run_xdp(xdp_prog, &xdp);
@@ -1391,6 +1550,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
int err;
u32 rxhash;
int skb_xdp = 1;
+ bool frags = tun_napi_frags_enabled(tun);
if (!(tun->dev->flags & IFF_UP))
return -EIO;
@@ -1448,7 +1608,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
zerocopy = true;
}
- if (tun_can_build_skb(tun, tfile, len, noblock, zerocopy)) {
+ if (!frags && tun_can_build_skb(tun, tfile, len, noblock, zerocopy)) {
/* For the packet that is not easy to be processed
* (e.g gso or jumbo packet), we will do it at after
* skb was created with generic XDP routine.
@@ -1469,10 +1629,24 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
linear = tun16_to_cpu(tun, gso.hdr_len);
}
- skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
+ if (frags) {
+ mutex_lock(&tfile->napi_mutex);
+ skb = tun_napi_alloc_frags(tfile, copylen, from);
+ /* tun_napi_alloc_frags() enforces a layout for the skb.
+ * If zerocopy is enabled, then this layout will be
+ * overwritten by zerocopy_sg_from_iter().
+ */
+ zerocopy = false;
+ } else {
+ skb = tun_alloc_skb(tfile, align, copylen, linear,
+ noblock);
+ }
+
if (IS_ERR(skb)) {
if (PTR_ERR(skb) != -EAGAIN)
this_cpu_inc(tun->pcpu_stats->rx_dropped);
+ if (frags)
+ mutex_unlock(&tfile->napi_mutex);
return PTR_ERR(skb);
}
@@ -1484,6 +1658,11 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
if (err) {
this_cpu_inc(tun->pcpu_stats->rx_dropped);
kfree_skb(skb);
+ if (frags) {
+ tfile->napi.skb = NULL;
+ mutex_unlock(&tfile->napi_mutex);
+ }
+
return -EFAULT;
}
}
@@ -1491,6 +1670,11 @@ 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))) {
this_cpu_inc(tun->pcpu_stats->rx_frame_errors);
kfree_skb(skb);
+ if (frags) {
+ tfile->napi.skb = NULL;
+ mutex_unlock(&tfile->napi_mutex);
+ }
+
return -EINVAL;
}
@@ -1518,7 +1702,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
skb->dev = tun->dev;
break;
case IFF_TAP:
- skb->protocol = eth_type_trans(skb, tun->dev);
+ if (!frags)
+ skb->protocol = eth_type_trans(skb, tun->dev);
break;
}
@@ -1552,11 +1737,41 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
}
rxhash = __skb_get_hash_symmetric(skb);
-#ifndef CONFIG_4KSTACKS
- tun_rx_batched(tun, tfile, skb, more);
-#else
- netif_rx_ni(skb);
-#endif
+
+ if (frags) {
+ /* Exercise flow dissector code path. */
+ u32 headlen = eth_get_headlen(skb->data, skb_headlen(skb));
+
+ if (unlikely(headlen > skb_headlen(skb))) {
+ this_cpu_inc(tun->pcpu_stats->rx_dropped);
+ napi_free_frags(&tfile->napi);
+ mutex_unlock(&tfile->napi_mutex);
+ WARN_ON(1);
+ return -ENOMEM;
+ }
+
+ local_bh_disable();
+ napi_gro_frags(&tfile->napi);
+ local_bh_enable();
+ mutex_unlock(&tfile->napi_mutex);
+ } else if (tfile->napi_enabled) {
+ struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
+ int queue_len;
+
+ spin_lock_bh(&queue->lock);
+ __skb_queue_tail(queue, skb);
+ queue_len = skb_queue_len(queue);
+ spin_unlock(&queue->lock);
+
+ if (!more || queue_len > NAPI_POLL_WEIGHT)
+ napi_schedule(&tfile->napi);
+
+ local_bh_enable();
+ } else if (!IS_ENABLED(CONFIG_4KSTACKS)) {
+ tun_rx_batched(tun, tfile, skb, more);
+ } else {
+ netif_rx_ni(skb);
+ }
stats = get_cpu_ptr(tun->pcpu_stats);
u64_stats_update_begin(&stats->syncp);
@@ -1572,8 +1787,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
- struct tun_struct *tun = tun_get(file);
struct tun_file *tfile = file->private_data;
+ struct tun_struct *tun = tun_get(tfile);
ssize_t result;
if (!tun)
@@ -1757,7 +1972,7 @@ static ssize_t tun_chr_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
struct file *file = iocb->ki_filp;
struct tun_file *tfile = file->private_data;
- struct tun_struct *tun = __tun_get(tfile);
+ struct tun_struct *tun = tun_get(tfile);
ssize_t len = iov_iter_count(to), ret;
if (!tun)
@@ -1834,7 +2049,7 @@ static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
{
int ret;
struct tun_file *tfile = container_of(sock, struct tun_file, socket);
- struct tun_struct *tun = __tun_get(tfile);
+ struct tun_struct *tun = tun_get(tfile);
if (!tun)
return -EBADFD;
@@ -1850,7 +2065,7 @@ static int tun_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len,
int flags)
{
struct tun_file *tfile = container_of(sock, struct tun_file, socket);
- struct tun_struct *tun = __tun_get(tfile);
+ struct tun_struct *tun = tun_get(tfile);
int ret;
if (!tun)
@@ -1882,7 +2097,7 @@ static int tun_peek_len(struct socket *sock)
struct tun_struct *tun;
int ret = 0;
- tun = __tun_get(tfile);
+ tun = tun_get(tfile);
if (!tun)
return 0;
@@ -1962,6 +2177,15 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
if (tfile->detached)
return -EINVAL;
+ if ((ifr->ifr_flags & IFF_NAPI_FRAGS)) {
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+
+ if (!(ifr->ifr_flags & IFF_NAPI) ||
+ (ifr->ifr_flags & TUN_TYPE_MASK) != IFF_TAP)
+ return -EINVAL;
+ }
+
dev = __dev_get_by_name(net, ifr->ifr_name);
if (dev) {
if (ifr->ifr_flags & IFF_TUN_EXCL)
@@ -1983,7 +2207,8 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
if (err < 0)
return err;
- err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER);
+ err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER,
+ ifr->ifr_flags & IFF_NAPI);
if (err < 0)
return err;
@@ -2072,7 +2297,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
NETIF_F_HW_VLAN_STAG_TX);
INIT_LIST_HEAD(&tun->disabled);
- err = tun_attach(tun, file, false);
+ err = tun_attach(tun, file, false, ifr->ifr_flags & IFF_NAPI);
if (err < 0)
goto err_free_flow;
@@ -2222,7 +2447,7 @@ static int tun_set_queue(struct file *file, struct ifreq *ifr)
ret = security_tun_dev_attach_queue(tun->security);
if (ret < 0)
goto unlock;
- ret = tun_attach(tun, file, false);
+ ret = tun_attach(tun, file, false, tun->flags & IFF_NAPI);
} else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
tun = rtnl_dereference(tfile->tun);
if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
@@ -2271,7 +2496,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
ret = 0;
rtnl_lock();
- tun = __tun_get(tfile);
+ tun = tun_get(tfile);
if (cmd == TUNSETIFF) {
ret = -EEXIST;
if (tun)
@@ -2622,15 +2847,16 @@ static int tun_chr_close(struct inode *inode, struct file *file)
}
#ifdef CONFIG_PROC_FS
-static void tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
+static void tun_chr_show_fdinfo(struct seq_file *m, struct file *file)
{
+ struct tun_file *tfile = file->private_data;
struct tun_struct *tun;
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
rtnl_lock();
- tun = tun_get(f);
+ tun = tun_get(tfile);
if (tun)
tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
rtnl_unlock();