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-rw-r--r--drivers/net/tun.c133
-rw-r--r--include/uapi/linux/if_tun.h1
2 files changed, 119 insertions, 15 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 3c9985f29950..f16407242b18 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -121,7 +121,7 @@ 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)
#define GOODCOPY_LEN 128
#define FLT_EXACT_COUNT 8
@@ -172,6 +172,7 @@ struct tun_file {
u16 queue_index;
unsigned int ifindex;
};
+ struct napi_struct napi;
struct list_head next;
struct tun_struct *detached;
struct skb_array tx_array;
@@ -229,6 +230,68 @@ 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)
+{
+ if (napi_en) {
+ netif_napi_add(tun->dev, &tfile->napi, tun_napi_poll,
+ NAPI_POLL_WEIGHT);
+ napi_enable(&tfile->napi);
+ }
+}
+
+static void tun_napi_disable(struct tun_struct *tun, struct tun_file *tfile)
+{
+ if (tun->flags & IFF_NAPI)
+ napi_disable(&tfile->napi);
+}
+
+static void tun_napi_del(struct tun_struct *tun, struct tun_file *tfile)
+{
+ if (tun->flags & IFF_NAPI)
+ netif_napi_del(&tfile->napi);
+}
+
#ifdef CONFIG_TUN_VNET_CROSS_LE
static inline bool tun_legacy_is_little_endian(struct tun_struct *tun)
{
@@ -541,6 +604,11 @@ 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 +666,7 @@ 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 +682,7 @@ 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 +701,8 @@ 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 +748,12 @@ 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);
@@ -956,13 +1029,28 @@ 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.
*/
+ struct tun_struct *tun = netdev_priv(dev);
+
+ if (tun->flags & IFF_NAPI) {
+ struct tun_file *tfile;
+ int i;
+
+ rcu_read_lock();
+ for (i = 0; i < tun->numqueues; i++) {
+ tfile = rcu_dereference(tun->tfiles[i]);
+ napi_schedule(&tfile->napi);
+ }
+ rcu_read_unlock();
+ }
return;
}
#endif
@@ -1549,11 +1637,25 @@ 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 (tun->flags & IFF_NAPI) {
+ 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);
@@ -1980,7 +2082,8 @@ 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;
@@ -2066,7 +2169,7 @@ 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;
@@ -2216,7 +2319,7 @@ 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)
diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h
index 3cb5e1d85ddd..30b6184884eb 100644
--- a/include/uapi/linux/if_tun.h
+++ b/include/uapi/linux/if_tun.h
@@ -60,6 +60,7 @@
/* TUNSETIFF ifr flags */
#define IFF_TUN 0x0001
#define IFF_TAP 0x0002
+#define IFF_NAPI 0x0010
#define IFF_NO_PI 0x1000
/* This flag has no real effect */
#define IFF_ONE_QUEUE 0x2000
generated by cgit (git 2.34.1) at 2024-06-19 08:20:43 +0000