v4.19.13 snapshot.
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
new file mode 100644
index 0000000..8c1abcb
--- /dev/null
+++ b/drivers/net/tun.c
@@ -0,0 +1,3522 @@
+/*
+ * TUN - Universal TUN/TAP device driver.
+ * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
+ */
+
+/*
+ * Changes:
+ *
+ * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14
+ * Add TUNSETLINK ioctl to set the link encapsulation
+ *
+ * Mark Smith <markzzzsmith@yahoo.com.au>
+ * Use eth_random_addr() for tap MAC address.
+ *
+ * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20
+ * Fixes in packet dropping, queue length setting and queue wakeup.
+ * Increased default tx queue length.
+ * Added ethtool API.
+ * Minor cleanups
+ *
+ * Daniel Podlejski <underley@underley.eu.org>
+ * Modifications for 2.3.99-pre5 kernel.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#define DRV_NAME "tun"
+#define DRV_VERSION "1.6"
+#define DRV_DESCRIPTION "Universal TUN/TAP device driver"
+#define DRV_COPYRIGHT "(C) 1999-2004 Max Krasnyansky <maxk@qualcomm.com>"
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/sched/signal.h>
+#include <linux/major.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/fcntl.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/miscdevice.h>
+#include <linux/ethtool.h>
+#include <linux/rtnetlink.h>
+#include <linux/compat.h>
+#include <linux/if.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/if_tun.h>
+#include <linux/if_vlan.h>
+#include <linux/crc32.h>
+#include <linux/nsproxy.h>
+#include <linux/virtio_net.h>
+#include <linux/rcupdate.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/rtnetlink.h>
+#include <net/sock.h>
+#include <net/xdp.h>
+#include <linux/seq_file.h>
+#include <linux/uio.h>
+#include <linux/skb_array.h>
+#include <linux/bpf.h>
+#include <linux/bpf_trace.h>
+#include <linux/mutex.h>
+
+#include <linux/uaccess.h>
+#include <linux/proc_fs.h>
+
+static void tun_default_link_ksettings(struct net_device *dev,
+ struct ethtool_link_ksettings *cmd);
+
+/* Uncomment to enable debugging */
+/* #define TUN_DEBUG 1 */
+
+#ifdef TUN_DEBUG
+static int debug;
+
+#define tun_debug(level, tun, fmt, args...) \
+do { \
+ if (tun->debug) \
+ netdev_printk(level, tun->dev, fmt, ##args); \
+} while (0)
+#define DBG1(level, fmt, args...) \
+do { \
+ if (debug == 2) \
+ printk(level fmt, ##args); \
+} while (0)
+#else
+#define tun_debug(level, tun, fmt, args...) \
+do { \
+ if (0) \
+ netdev_printk(level, tun->dev, fmt, ##args); \
+} while (0)
+#define DBG1(level, fmt, args...) \
+do { \
+ if (0) \
+ printk(level fmt, ##args); \
+} while (0)
+#endif
+
+#define TUN_HEADROOM 256
+#define TUN_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
+
+/* TUN device flags */
+
+/* IFF_ATTACH_QUEUE is never stored in device flags,
+ * 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)
+
+#define GOODCOPY_LEN 128
+
+#define FLT_EXACT_COUNT 8
+struct tap_filter {
+ unsigned int count; /* Number of addrs. Zero means disabled */
+ u32 mask[2]; /* Mask of the hashed addrs */
+ unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN];
+};
+
+/* MAX_TAP_QUEUES 256 is chosen to allow rx/tx queues to be equal
+ * to max number of VCPUs in guest. */
+#define MAX_TAP_QUEUES 256
+#define MAX_TAP_FLOWS 4096
+
+#define TUN_FLOW_EXPIRE (3 * HZ)
+
+struct tun_pcpu_stats {
+ u64 rx_packets;
+ u64 rx_bytes;
+ u64 tx_packets;
+ u64 tx_bytes;
+ struct u64_stats_sync syncp;
+ u32 rx_dropped;
+ u32 tx_dropped;
+ u32 rx_frame_errors;
+};
+
+/* A tun_file connects an open character device to a tuntap netdevice. It
+ * also contains all socket related structures (except sock_fprog and tap_filter)
+ * to serve as one transmit queue for tuntap device. The sock_fprog and
+ * tap_filter were kept in tun_struct since they were used for filtering for the
+ * netdevice not for a specific queue (at least I didn't see the requirement for
+ * this).
+ *
+ * RCU usage:
+ * The tun_file and tun_struct are loosely coupled, the pointer from one to the
+ * other can only be read while rcu_read_lock or rtnl_lock is held.
+ */
+struct tun_file {
+ struct sock sk;
+ struct socket socket;
+ struct socket_wq wq;
+ struct tun_struct __rcu *tun;
+ struct fasync_struct *fasync;
+ /* only used for fasnyc */
+ unsigned int flags;
+ union {
+ u16 queue_index;
+ unsigned int ifindex;
+ };
+ struct napi_struct napi;
+ bool napi_enabled;
+ bool napi_frags_enabled;
+ struct mutex napi_mutex; /* Protects access to the above napi */
+ struct list_head next;
+ struct tun_struct *detached;
+ struct ptr_ring tx_ring;
+ struct xdp_rxq_info xdp_rxq;
+};
+
+struct tun_flow_entry {
+ struct hlist_node hash_link;
+ struct rcu_head rcu;
+ struct tun_struct *tun;
+
+ u32 rxhash;
+ u32 rps_rxhash;
+ int queue_index;
+ unsigned long updated;
+};
+
+#define TUN_NUM_FLOW_ENTRIES 1024
+#define TUN_MASK_FLOW_ENTRIES (TUN_NUM_FLOW_ENTRIES - 1)
+
+struct tun_prog {
+ struct rcu_head rcu;
+ struct bpf_prog *prog;
+};
+
+/* Since the socket were moved to tun_file, to preserve the behavior of persist
+ * device, socket filter, sndbuf and vnet header size were restore when the
+ * file were attached to a persist device.
+ */
+struct tun_struct {
+ struct tun_file __rcu *tfiles[MAX_TAP_QUEUES];
+ unsigned int numqueues;
+ unsigned int flags;
+ kuid_t owner;
+ kgid_t group;
+
+ struct net_device *dev;
+ netdev_features_t set_features;
+#define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \
+ NETIF_F_TSO6)
+
+ int align;
+ int vnet_hdr_sz;
+ int sndbuf;
+ struct tap_filter txflt;
+ struct sock_fprog fprog;
+ /* protected by rtnl lock */
+ bool filter_attached;
+#ifdef TUN_DEBUG
+ int debug;
+#endif
+ spinlock_t lock;
+ struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
+ struct timer_list flow_gc_timer;
+ unsigned long ageing_time;
+ unsigned int numdisabled;
+ struct list_head disabled;
+ void *security;
+ u32 flow_count;
+ u32 rx_batched;
+ struct tun_pcpu_stats __percpu *pcpu_stats;
+ struct bpf_prog __rcu *xdp_prog;
+ struct tun_prog __rcu *steering_prog;
+ struct tun_prog __rcu *filter_prog;
+ struct ethtool_link_ksettings link_ksettings;
+};
+
+struct veth {
+ __be16 h_vlan_proto;
+ __be16 h_vlan_TCI;
+};
+
+bool tun_is_xdp_frame(void *ptr)
+{
+ return (unsigned long)ptr & TUN_XDP_FLAG;
+}
+EXPORT_SYMBOL(tun_is_xdp_frame);
+
+void *tun_xdp_to_ptr(void *ptr)
+{
+ return (void *)((unsigned long)ptr | TUN_XDP_FLAG);
+}
+EXPORT_SYMBOL(tun_xdp_to_ptr);
+
+void *tun_ptr_to_xdp(void *ptr)
+{
+ return (void *)((unsigned long)ptr & ~TUN_XDP_FLAG);
+}
+EXPORT_SYMBOL(tun_ptr_to_xdp);
+
+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, bool napi_frags)
+{
+ tfile->napi_enabled = napi_en;
+ tfile->napi_frags_enabled = napi_en && napi_frags;
+ 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_file *tfile)
+{
+ if (tfile->napi_enabled)
+ napi_disable(&tfile->napi);
+}
+
+static void tun_napi_del(struct tun_file *tfile)
+{
+ if (tfile->napi_enabled)
+ netif_napi_del(&tfile->napi);
+}
+
+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;
+}
+
+static struct tun_flow_entry *tun_flow_find(struct hlist_head *head, u32 rxhash)
+{
+ struct tun_flow_entry *e;
+
+ hlist_for_each_entry_rcu(e, head, hash_link) {
+ if (e->rxhash == rxhash)
+ return e;
+ }
+ return NULL;
+}
+
+static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
+ struct hlist_head *head,
+ u32 rxhash, u16 queue_index)
+{
+ struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
+
+ if (e) {
+ tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
+ rxhash, queue_index);
+ e->updated = jiffies;
+ e->rxhash = rxhash;
+ e->rps_rxhash = 0;
+ e->queue_index = queue_index;
+ e->tun = tun;
+ hlist_add_head_rcu(&e->hash_link, head);
+ ++tun->flow_count;
+ }
+ return e;
+}
+
+static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
+{
+ tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
+ e->rxhash, e->queue_index);
+ hlist_del_rcu(&e->hash_link);
+ kfree_rcu(e, rcu);
+ --tun->flow_count;
+}
+
+static void tun_flow_flush(struct tun_struct *tun)
+{
+ int i;
+
+ spin_lock_bh(&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)
+ tun_flow_delete(tun, e);
+ }
+ spin_unlock_bh(&tun->lock);
+}
+
+static void tun_flow_delete_by_queue(struct tun_struct *tun, u16 queue_index)
+{
+ int i;
+
+ spin_lock_bh(&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) {
+ if (e->queue_index == queue_index)
+ tun_flow_delete(tun, e);
+ }
+ }
+ spin_unlock_bh(&tun->lock);
+}
+
+static void tun_flow_cleanup(struct timer_list *t)
+{
+ struct tun_struct *tun = from_timer(tun, t, flow_gc_timer);
+ unsigned long delay = tun->ageing_time;
+ unsigned long next_timer = jiffies + delay;
+ unsigned long count = 0;
+ int i;
+
+ tun_debug(KERN_INFO, tun, "tun_flow_cleanup\n");
+
+ 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;
+
+ this_timer = e->updated + delay;
+ if (time_before_eq(this_timer, jiffies)) {
+ tun_flow_delete(tun, e);
+ 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(&tun->lock);
+}
+
+static void tun_flow_update(struct tun_struct *tun, u32 rxhash,
+ struct tun_file *tfile)
+{
+ struct hlist_head *head;
+ struct tun_flow_entry *e;
+ unsigned long delay = tun->ageing_time;
+ u16 queue_index = tfile->queue_index;
+
+ if (!rxhash)
+ return;
+ else
+ head = &tun->flows[tun_hashfn(rxhash)];
+
+ rcu_read_lock();
+
+ e = tun_flow_find(head, rxhash);
+ if (likely(e)) {
+ /* TODO: keep queueing to old queue until it's empty? */
+ e->queue_index = queue_index;
+ e->updated = jiffies;
+ sock_rps_record_flow_hash(e->rps_rxhash);
+ } else {
+ spin_lock_bh(&tun->lock);
+ if (!tun_flow_find(head, rxhash) &&
+ tun->flow_count < MAX_TAP_FLOWS)
+ tun_flow_create(tun, head, rxhash, queue_index);
+
+ if (!timer_pending(&tun->flow_gc_timer))
+ mod_timer(&tun->flow_gc_timer,
+ round_jiffies_up(jiffies + delay));
+ spin_unlock_bh(&tun->lock);
+ }
+
+ rcu_read_unlock();
+}
+
+/**
+ * Save the hash received in the stack receive path and update the
+ * flow_hash table accordingly.
+ */
+static inline void tun_flow_save_rps_rxhash(struct tun_flow_entry *e, u32 hash)
+{
+ if (unlikely(e->rps_rxhash != hash))
+ e->rps_rxhash = hash;
+}
+
+/* We try to identify a flow through its rxhash first. The reason that
+ * we do not check rxq no. is because some cards(e.g 82599), chooses
+ * the rxq based on the txq where the last packet of the flow comes. As
+ * the userspace application move between processors, we may get a
+ * different rxq no. here. If we could not get rxhash, then we would
+ * hope the rxq no. may help here.
+ */
+static u16 tun_automq_select_queue(struct tun_struct *tun, struct sk_buff *skb)
+{
+ struct tun_flow_entry *e;
+ u32 txq = 0;
+ u32 numqueues = 0;
+
+ numqueues = READ_ONCE(tun->numqueues);
+
+ txq = __skb_get_hash_symmetric(skb);
+ if (txq) {
+ e = tun_flow_find(&tun->flows[tun_hashfn(txq)], txq);
+ if (e) {
+ tun_flow_save_rps_rxhash(e, txq);
+ txq = e->queue_index;
+ } else
+ /* use multiply and shift instead of expensive divide */
+ txq = ((u64)txq * numqueues) >> 32;
+ } else if (likely(skb_rx_queue_recorded(skb))) {
+ txq = skb_get_rx_queue(skb);
+ while (unlikely(txq >= numqueues))
+ txq -= numqueues;
+ }
+
+ return txq;
+}
+
+static u16 tun_ebpf_select_queue(struct tun_struct *tun, struct sk_buff *skb)
+{
+ struct tun_prog *prog;
+ u16 ret = 0;
+
+ prog = rcu_dereference(tun->steering_prog);
+ if (prog)
+ ret = bpf_prog_run_clear_cb(prog->prog, skb);
+
+ return ret % tun->numqueues;
+}
+
+static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb,
+ struct net_device *sb_dev,
+ select_queue_fallback_t fallback)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+ u16 ret;
+
+ rcu_read_lock();
+ if (rcu_dereference(tun->steering_prog))
+ ret = tun_ebpf_select_queue(tun, skb);
+ else
+ ret = tun_automq_select_queue(tun, skb);
+ rcu_read_unlock();
+
+ return ret;
+}
+
+static inline bool tun_not_capable(struct tun_struct *tun)
+{
+ const struct cred *cred = current_cred();
+ struct net *net = dev_net(tun->dev);
+
+ return ((uid_valid(tun->owner) && !uid_eq(cred->euid, tun->owner)) ||
+ (gid_valid(tun->group) && !in_egroup_p(tun->group))) &&
+ !ns_capable(net->user_ns, CAP_NET_ADMIN);
+}
+
+static void tun_set_real_num_queues(struct tun_struct *tun)
+{
+ netif_set_real_num_tx_queues(tun->dev, tun->numqueues);
+ netif_set_real_num_rx_queues(tun->dev, tun->numqueues);
+}
+
+static void tun_disable_queue(struct tun_struct *tun, struct tun_file *tfile)
+{
+ tfile->detached = tun;
+ list_add_tail(&tfile->next, &tun->disabled);
+ ++tun->numdisabled;
+}
+
+static struct tun_struct *tun_enable_queue(struct tun_file *tfile)
+{
+ struct tun_struct *tun = tfile->detached;
+
+ tfile->detached = NULL;
+ list_del_init(&tfile->next);
+ --tun->numdisabled;
+ return tun;
+}
+
+void tun_ptr_free(void *ptr)
+{
+ if (!ptr)
+ return;
+ if (tun_is_xdp_frame(ptr)) {
+ struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
+
+ xdp_return_frame(xdpf);
+ } else {
+ __skb_array_destroy_skb(ptr);
+ }
+}
+EXPORT_SYMBOL_GPL(tun_ptr_free);
+
+static void tun_queue_purge(struct tun_file *tfile)
+{
+ void *ptr;
+
+ while ((ptr = ptr_ring_consume(&tfile->tx_ring)) != NULL)
+ tun_ptr_free(ptr);
+
+ skb_queue_purge(&tfile->sk.sk_write_queue);
+ skb_queue_purge(&tfile->sk.sk_error_queue);
+}
+
+static void __tun_detach(struct tun_file *tfile, bool clean)
+{
+ struct tun_file *ntfile;
+ struct tun_struct *tun;
+
+ tun = rtnl_dereference(tfile->tun);
+
+ if (tun && clean) {
+ tun_napi_disable(tfile);
+ tun_napi_del(tfile);
+ }
+
+ if (tun && !tfile->detached) {
+ u16 index = tfile->queue_index;
+ BUG_ON(index >= tun->numqueues);
+
+ rcu_assign_pointer(tun->tfiles[index],
+ tun->tfiles[tun->numqueues - 1]);
+ ntfile = rtnl_dereference(tun->tfiles[index]);
+ ntfile->queue_index = index;
+
+ --tun->numqueues;
+ if (clean) {
+ RCU_INIT_POINTER(tfile->tun, NULL);
+ sock_put(&tfile->sk);
+ } else
+ tun_disable_queue(tun, tfile);
+
+ synchronize_net();
+ tun_flow_delete_by_queue(tun, tun->numqueues + 1);
+ /* Drop read queue */
+ tun_queue_purge(tfile);
+ tun_set_real_num_queues(tun);
+ } else if (tfile->detached && clean) {
+ tun = tun_enable_queue(tfile);
+ sock_put(&tfile->sk);
+ }
+
+ if (clean) {
+ if (tun && tun->numqueues == 0 && tun->numdisabled == 0) {
+ netif_carrier_off(tun->dev);
+
+ if (!(tun->flags & IFF_PERSIST) &&
+ tun->dev->reg_state == NETREG_REGISTERED)
+ unregister_netdevice(tun->dev);
+ }
+ if (tun)
+ xdp_rxq_info_unreg(&tfile->xdp_rxq);
+ ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
+ sock_put(&tfile->sk);
+ }
+}
+
+static void tun_detach(struct tun_file *tfile, bool clean)
+{
+ struct tun_struct *tun;
+ struct net_device *dev;
+
+ rtnl_lock();
+ tun = rtnl_dereference(tfile->tun);
+ dev = tun ? tun->dev : NULL;
+ __tun_detach(tfile, clean);
+ if (dev)
+ netdev_state_change(dev);
+ rtnl_unlock();
+}
+
+static void tun_detach_all(struct net_device *dev)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+ struct tun_file *tfile, *tmp;
+ int i, n = tun->numqueues;
+
+ for (i = 0; i < n; i++) {
+ tfile = rtnl_dereference(tun->tfiles[i]);
+ BUG_ON(!tfile);
+ tun_napi_disable(tfile);
+ tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
+ tfile->socket.sk->sk_data_ready(tfile->socket.sk);
+ RCU_INIT_POINTER(tfile->tun, NULL);
+ --tun->numqueues;
+ }
+ list_for_each_entry(tfile, &tun->disabled, next) {
+ tfile->socket.sk->sk_shutdown = RCV_SHUTDOWN;
+ tfile->socket.sk->sk_data_ready(tfile->socket.sk);
+ RCU_INIT_POINTER(tfile->tun, NULL);
+ }
+ BUG_ON(tun->numqueues != 0);
+
+ synchronize_net();
+ for (i = 0; i < n; i++) {
+ tfile = rtnl_dereference(tun->tfiles[i]);
+ tun_napi_del(tfile);
+ /* Drop read queue */
+ tun_queue_purge(tfile);
+ xdp_rxq_info_unreg(&tfile->xdp_rxq);
+ sock_put(&tfile->sk);
+ }
+ list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
+ tun_enable_queue(tfile);
+ tun_queue_purge(tfile);
+ xdp_rxq_info_unreg(&tfile->xdp_rxq);
+ sock_put(&tfile->sk);
+ }
+ BUG_ON(tun->numdisabled != 0);
+
+ if (tun->flags & IFF_PERSIST)
+ module_put(THIS_MODULE);
+}
+
+static int tun_attach(struct tun_struct *tun, struct file *file,
+ bool skip_filter, bool napi, bool napi_frags)
+{
+ struct tun_file *tfile = file->private_data;
+ struct net_device *dev = tun->dev;
+ int err;
+
+ err = security_tun_dev_attach(tfile->socket.sk, tun->security);
+ if (err < 0)
+ goto out;
+
+ err = -EINVAL;
+ if (rtnl_dereference(tfile->tun) && !tfile->detached)
+ goto out;
+
+ err = -EBUSY;
+ if (!(tun->flags & IFF_MULTI_QUEUE) && tun->numqueues == 1)
+ goto out;
+
+ err = -E2BIG;
+ if (!tfile->detached &&
+ tun->numqueues + tun->numdisabled == MAX_TAP_QUEUES)
+ goto out;
+
+ err = 0;
+
+ /* Re-attach the filter to persist device */
+ if (!skip_filter && (tun->filter_attached == true)) {
+ lock_sock(tfile->socket.sk);
+ err = sk_attach_filter(&tun->fprog, tfile->socket.sk);
+ release_sock(tfile->socket.sk);
+ if (!err)
+ goto out;
+ }
+
+ if (!tfile->detached &&
+ ptr_ring_resize(&tfile->tx_ring, dev->tx_queue_len,
+ GFP_KERNEL, tun_ptr_free)) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ tfile->queue_index = tun->numqueues;
+ tfile->socket.sk->sk_shutdown &= ~RCV_SHUTDOWN;
+
+ if (tfile->detached) {
+ /* Re-attach detached tfile, updating XDP queue_index */
+ WARN_ON(!xdp_rxq_info_is_reg(&tfile->xdp_rxq));
+
+ if (tfile->xdp_rxq.queue_index != tfile->queue_index)
+ tfile->xdp_rxq.queue_index = tfile->queue_index;
+ } else {
+ /* Setup XDP RX-queue info, for new tfile getting attached */
+ err = xdp_rxq_info_reg(&tfile->xdp_rxq,
+ tun->dev, tfile->queue_index);
+ if (err < 0)
+ goto out;
+ err = xdp_rxq_info_reg_mem_model(&tfile->xdp_rxq,
+ MEM_TYPE_PAGE_SHARED, NULL);
+ if (err < 0) {
+ xdp_rxq_info_unreg(&tfile->xdp_rxq);
+ goto out;
+ }
+ err = 0;
+ }
+
+ rcu_assign_pointer(tfile->tun, tun);
+ rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);
+ tun->numqueues++;
+
+ if (tfile->detached) {
+ tun_enable_queue(tfile);
+ } else {
+ sock_hold(&tfile->sk);
+ tun_napi_init(tun, tfile, napi, napi_frags);
+ }
+
+ tun_set_real_num_queues(tun);
+
+ /* device is allowed to go away first, so no need to hold extra
+ * refcnt.
+ */
+
+out:
+ return err;
+}
+
+static struct tun_struct *tun_get(struct tun_file *tfile)
+{
+ struct tun_struct *tun;
+
+ rcu_read_lock();
+ tun = rcu_dereference(tfile->tun);
+ if (tun)
+ dev_hold(tun->dev);
+ rcu_read_unlock();
+
+ return tun;
+}
+
+static void tun_put(struct tun_struct *tun)
+{
+ dev_put(tun->dev);
+}
+
+/* TAP filtering */
+static void addr_hash_set(u32 *mask, const u8 *addr)
+{
+ int n = ether_crc(ETH_ALEN, addr) >> 26;
+ mask[n >> 5] |= (1 << (n & 31));
+}
+
+static unsigned int addr_hash_test(const u32 *mask, const u8 *addr)
+{
+ int n = ether_crc(ETH_ALEN, addr) >> 26;
+ return mask[n >> 5] & (1 << (n & 31));
+}
+
+static int update_filter(struct tap_filter *filter, void __user *arg)
+{
+ struct { u8 u[ETH_ALEN]; } *addr;
+ struct tun_filter uf;
+ int err, alen, n, nexact;
+
+ if (copy_from_user(&uf, arg, sizeof(uf)))
+ return -EFAULT;
+
+ if (!uf.count) {
+ /* Disabled */
+ filter->count = 0;
+ return 0;
+ }
+
+ alen = ETH_ALEN * uf.count;
+ addr = memdup_user(arg + sizeof(uf), alen);
+ if (IS_ERR(addr))
+ return PTR_ERR(addr);
+
+ /* The filter is updated without holding any locks. Which is
+ * perfectly safe. We disable it first and in the worst
+ * case we'll accept a few undesired packets. */
+ filter->count = 0;
+ wmb();
+
+ /* Use first set of addresses as an exact filter */
+ for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++)
+ memcpy(filter->addr[n], addr[n].u, ETH_ALEN);
+
+ nexact = n;
+
+ /* Remaining multicast addresses are hashed,
+ * unicast will leave the filter disabled. */
+ memset(filter->mask, 0, sizeof(filter->mask));
+ for (; n < uf.count; n++) {
+ if (!is_multicast_ether_addr(addr[n].u)) {
+ err = 0; /* no filter */
+ goto free_addr;
+ }
+ addr_hash_set(filter->mask, addr[n].u);
+ }
+
+ /* For ALLMULTI just set the mask to all ones.
+ * This overrides the mask populated above. */
+ if ((uf.flags & TUN_FLT_ALLMULTI))
+ memset(filter->mask, ~0, sizeof(filter->mask));
+
+ /* Now enable the filter */
+ wmb();
+ filter->count = nexact;
+
+ /* Return the number of exact filters */
+ err = nexact;
+free_addr:
+ kfree(addr);
+ return err;
+}
+
+/* Returns: 0 - drop, !=0 - accept */
+static int run_filter(struct tap_filter *filter, const struct sk_buff *skb)
+{
+ /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect
+ * at this point. */
+ struct ethhdr *eh = (struct ethhdr *) skb->data;
+ int i;
+
+ /* Exact match */
+ for (i = 0; i < filter->count; i++)
+ if (ether_addr_equal(eh->h_dest, filter->addr[i]))
+ return 1;
+
+ /* Inexact match (multicast only) */
+ if (is_multicast_ether_addr(eh->h_dest))
+ return addr_hash_test(filter->mask, eh->h_dest);
+
+ return 0;
+}
+
+/*
+ * Checks whether the packet is accepted or not.
+ * Returns: 0 - drop, !=0 - accept
+ */
+static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
+{
+ if (!filter->count)
+ return 1;
+
+ return run_filter(filter, skb);
+}
+
+/* Network device part of the driver */
+
+static const struct ethtool_ops tun_ethtool_ops;
+
+/* Net device detach from fd. */
+static void tun_net_uninit(struct net_device *dev)
+{
+ tun_detach_all(dev);
+}
+
+/* Net device open. */
+static int tun_net_open(struct net_device *dev)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+ int i;
+
+ netif_tx_start_all_queues(dev);
+
+ for (i = 0; i < tun->numqueues; i++) {
+ struct tun_file *tfile;
+
+ tfile = rtnl_dereference(tun->tfiles[i]);
+ tfile->socket.sk->sk_write_space(tfile->socket.sk);
+ }
+
+ return 0;
+}
+
+/* Net device close. */
+static int tun_net_close(struct net_device *dev)
+{
+ netif_tx_stop_all_queues(dev);
+ return 0;
+}
+
+/* Net device start xmit */
+static void tun_automq_xmit(struct tun_struct *tun, struct sk_buff *skb)
+{
+#ifdef CONFIG_RPS
+ if (tun->numqueues == 1 && static_key_false(&rps_needed)) {
+ /* Select queue was not called for the skbuff, so we extract the
+ * RPS hash and save it into the flow_table here.
+ */
+ __u32 rxhash;
+
+ rxhash = __skb_get_hash_symmetric(skb);
+ if (rxhash) {
+ struct tun_flow_entry *e;
+ e = tun_flow_find(&tun->flows[tun_hashfn(rxhash)],
+ rxhash);
+ if (e)
+ tun_flow_save_rps_rxhash(e, rxhash);
+ }
+ }
+#endif
+}
+
+static unsigned int run_ebpf_filter(struct tun_struct *tun,
+ struct sk_buff *skb,
+ int len)
+{
+ struct tun_prog *prog = rcu_dereference(tun->filter_prog);
+
+ if (prog)
+ len = bpf_prog_run_clear_cb(prog->prog, skb);
+
+ return len;
+}
+
+/* Net device start xmit */
+static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+ int txq = skb->queue_mapping;
+ struct tun_file *tfile;
+ int len = skb->len;
+
+ rcu_read_lock();
+ tfile = rcu_dereference(tun->tfiles[txq]);
+
+ /* Drop packet if interface is not attached */
+ if (txq >= tun->numqueues)
+ goto drop;
+
+ if (!rcu_dereference(tun->steering_prog))
+ tun_automq_xmit(tun, skb);
+
+ tun_debug(KERN_INFO, tun, "tun_net_xmit %d\n", skb->len);
+
+ BUG_ON(!tfile);
+
+ /* Drop if the filter does not like it.
+ * This is a noop if the filter is disabled.
+ * Filter can be enabled only for the TAP devices. */
+ if (!check_filter(&tun->txflt, skb))
+ goto drop;
+
+ if (tfile->socket.sk->sk_filter &&
+ sk_filter(tfile->socket.sk, skb))
+ goto drop;
+
+ len = run_ebpf_filter(tun, skb, len);
+ if (len == 0 || pskb_trim(skb, len))
+ goto drop;
+
+ if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
+ goto drop;
+
+ skb_tx_timestamp(skb);
+
+ /* Orphan the skb - required as we might hang on to it
+ * for indefinite time.
+ */
+ skb_orphan(skb);
+
+ nf_reset(skb);
+
+ if (ptr_ring_produce(&tfile->tx_ring, skb))
+ goto drop;
+
+ /* Notify and wake up reader process */
+ if (tfile->flags & TUN_FASYNC)
+ kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
+ tfile->socket.sk->sk_data_ready(tfile->socket.sk);
+
+ rcu_read_unlock();
+ return NETDEV_TX_OK;
+
+drop:
+ this_cpu_inc(tun->pcpu_stats->tx_dropped);
+ skb_tx_error(skb);
+ kfree_skb(skb);
+ rcu_read_unlock();
+ return NET_XMIT_DROP;
+}
+
+static void tun_net_mclist(struct net_device *dev)
+{
+ /*
+ * This callback is supposed to deal with mc filter in
+ * _rx_ path and has nothing to do with the _tx_ path.
+ * In rx path we always accept everything userspace gives us.
+ */
+}
+
+static netdev_features_t tun_net_fix_features(struct net_device *dev,
+ netdev_features_t features)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+
+ return (features & tun->set_features) | (features & ~TUN_USER_FEATURES);
+}
+
+static void tun_set_headroom(struct net_device *dev, int new_hr)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+
+ if (new_hr < NET_SKB_PAD)
+ new_hr = NET_SKB_PAD;
+
+ tun->align = new_hr;
+}
+
+static void
+tun_net_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
+{
+ u32 rx_dropped = 0, tx_dropped = 0, rx_frame_errors = 0;
+ struct tun_struct *tun = netdev_priv(dev);
+ struct tun_pcpu_stats *p;
+ int i;
+
+ for_each_possible_cpu(i) {
+ u64 rxpackets, rxbytes, txpackets, txbytes;
+ unsigned int start;
+
+ p = per_cpu_ptr(tun->pcpu_stats, i);
+ do {
+ start = u64_stats_fetch_begin(&p->syncp);
+ rxpackets = p->rx_packets;
+ rxbytes = p->rx_bytes;
+ txpackets = p->tx_packets;
+ txbytes = p->tx_bytes;
+ } while (u64_stats_fetch_retry(&p->syncp, start));
+
+ stats->rx_packets += rxpackets;
+ stats->rx_bytes += rxbytes;
+ stats->tx_packets += txpackets;
+ stats->tx_bytes += txbytes;
+
+ /* u32 counters */
+ rx_dropped += p->rx_dropped;
+ rx_frame_errors += p->rx_frame_errors;
+ tx_dropped += p->tx_dropped;
+ }
+ stats->rx_dropped = rx_dropped;
+ stats->rx_frame_errors = rx_frame_errors;
+ stats->tx_dropped = tx_dropped;
+}
+
+static int tun_xdp_set(struct net_device *dev, struct bpf_prog *prog,
+ struct netlink_ext_ack *extack)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+ struct bpf_prog *old_prog;
+
+ old_prog = rtnl_dereference(tun->xdp_prog);
+ rcu_assign_pointer(tun->xdp_prog, prog);
+ if (old_prog)
+ bpf_prog_put(old_prog);
+
+ return 0;
+}
+
+static u32 tun_xdp_query(struct net_device *dev)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+ const struct bpf_prog *xdp_prog;
+
+ xdp_prog = rtnl_dereference(tun->xdp_prog);
+ if (xdp_prog)
+ return xdp_prog->aux->id;
+
+ return 0;
+}
+
+static int tun_xdp(struct net_device *dev, struct netdev_bpf *xdp)
+{
+ switch (xdp->command) {
+ case XDP_SETUP_PROG:
+ return tun_xdp_set(dev, xdp->prog, xdp->extack);
+ case XDP_QUERY_PROG:
+ xdp->prog_id = tun_xdp_query(dev);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct net_device_ops tun_netdev_ops = {
+ .ndo_uninit = tun_net_uninit,
+ .ndo_open = tun_net_open,
+ .ndo_stop = tun_net_close,
+ .ndo_start_xmit = tun_net_xmit,
+ .ndo_fix_features = tun_net_fix_features,
+ .ndo_select_queue = tun_select_queue,
+ .ndo_set_rx_headroom = tun_set_headroom,
+ .ndo_get_stats64 = tun_net_get_stats64,
+};
+
+static void __tun_xdp_flush_tfile(struct tun_file *tfile)
+{
+ /* Notify and wake up reader process */
+ if (tfile->flags & TUN_FASYNC)
+ kill_fasync(&tfile->fasync, SIGIO, POLL_IN);
+ tfile->socket.sk->sk_data_ready(tfile->socket.sk);
+}
+
+static int tun_xdp_xmit(struct net_device *dev, int n,
+ struct xdp_frame **frames, u32 flags)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+ struct tun_file *tfile;
+ u32 numqueues;
+ int drops = 0;
+ int cnt = n;
+ int i;
+
+ if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
+ return -EINVAL;
+
+ rcu_read_lock();
+
+ numqueues = READ_ONCE(tun->numqueues);
+ if (!numqueues) {
+ rcu_read_unlock();
+ return -ENXIO; /* Caller will free/return all frames */
+ }
+
+ tfile = rcu_dereference(tun->tfiles[smp_processor_id() %
+ numqueues]);
+
+ spin_lock(&tfile->tx_ring.producer_lock);
+ for (i = 0; i < n; i++) {
+ struct xdp_frame *xdp = frames[i];
+ /* Encode the XDP flag into lowest bit for consumer to differ
+ * XDP buffer from sk_buff.
+ */
+ void *frame = tun_xdp_to_ptr(xdp);
+
+ if (__ptr_ring_produce(&tfile->tx_ring, frame)) {
+ this_cpu_inc(tun->pcpu_stats->tx_dropped);
+ xdp_return_frame_rx_napi(xdp);
+ drops++;
+ }
+ }
+ spin_unlock(&tfile->tx_ring.producer_lock);
+
+ if (flags & XDP_XMIT_FLUSH)
+ __tun_xdp_flush_tfile(tfile);
+
+ rcu_read_unlock();
+ return cnt - drops;
+}
+
+static int tun_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
+{
+ struct xdp_frame *frame = convert_to_xdp_frame(xdp);
+
+ if (unlikely(!frame))
+ return -EOVERFLOW;
+
+ return tun_xdp_xmit(dev, 1, &frame, XDP_XMIT_FLUSH);
+}
+
+static const struct net_device_ops tap_netdev_ops = {
+ .ndo_uninit = tun_net_uninit,
+ .ndo_open = tun_net_open,
+ .ndo_stop = tun_net_close,
+ .ndo_start_xmit = tun_net_xmit,
+ .ndo_fix_features = tun_net_fix_features,
+ .ndo_set_rx_mode = tun_net_mclist,
+ .ndo_set_mac_address = eth_mac_addr,
+ .ndo_validate_addr = eth_validate_addr,
+ .ndo_select_queue = tun_select_queue,
+ .ndo_features_check = passthru_features_check,
+ .ndo_set_rx_headroom = tun_set_headroom,
+ .ndo_get_stats64 = tun_net_get_stats64,
+ .ndo_bpf = tun_xdp,
+ .ndo_xdp_xmit = tun_xdp_xmit,
+};
+
+static void tun_flow_init(struct tun_struct *tun)
+{
+ int i;
+
+ for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
+ INIT_HLIST_HEAD(&tun->flows[i]);
+
+ tun->ageing_time = TUN_FLOW_EXPIRE;
+ timer_setup(&tun->flow_gc_timer, tun_flow_cleanup, 0);
+ mod_timer(&tun->flow_gc_timer,
+ round_jiffies_up(jiffies + tun->ageing_time));
+}
+
+static void tun_flow_uninit(struct tun_struct *tun)
+{
+ del_timer_sync(&tun->flow_gc_timer);
+ tun_flow_flush(tun);
+}
+
+#define MIN_MTU 68
+#define MAX_MTU 65535
+
+/* Initialize net device. */
+static void tun_net_init(struct net_device *dev)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+
+ switch (tun->flags & TUN_TYPE_MASK) {
+ case IFF_TUN:
+ dev->netdev_ops = &tun_netdev_ops;
+
+ /* Point-to-Point TUN Device */
+ dev->hard_header_len = 0;
+ dev->addr_len = 0;
+ dev->mtu = 1500;
+
+ /* Zero header length */
+ dev->type = ARPHRD_NONE;
+ dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+ break;
+
+ case IFF_TAP:
+ dev->netdev_ops = &tap_netdev_ops;
+ /* Ethernet TAP Device */
+ ether_setup(dev);
+ dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+ dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+
+ eth_hw_addr_random(dev);
+
+ break;
+ }
+
+ dev->min_mtu = MIN_MTU;
+ dev->max_mtu = MAX_MTU - dev->hard_header_len;
+}
+
+static bool tun_sock_writeable(struct tun_struct *tun, struct tun_file *tfile)
+{
+ struct sock *sk = tfile->socket.sk;
+
+ return (tun->dev->flags & IFF_UP) && sock_writeable(sk);
+}
+
+/* Character device part */
+
+/* Poll */
+static __poll_t tun_chr_poll(struct file *file, poll_table *wait)
+{
+ struct tun_file *tfile = file->private_data;
+ struct tun_struct *tun = tun_get(tfile);
+ struct sock *sk;
+ __poll_t mask = 0;
+
+ if (!tun)
+ return EPOLLERR;
+
+ sk = tfile->socket.sk;
+
+ tun_debug(KERN_INFO, tun, "tun_chr_poll\n");
+
+ poll_wait(file, sk_sleep(sk), wait);
+
+ if (!ptr_ring_empty(&tfile->tx_ring))
+ mask |= EPOLLIN | EPOLLRDNORM;
+
+ /* Make sure SOCKWQ_ASYNC_NOSPACE is set if not writable to
+ * guarantee EPOLLOUT to be raised by either here or
+ * tun_sock_write_space(). Then process could get notification
+ * after it writes to a down device and meets -EIO.
+ */
+ if (tun_sock_writeable(tun, tfile) ||
+ (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
+ tun_sock_writeable(tun, tfile)))
+ mask |= EPOLLOUT | EPOLLWRNORM;
+
+ if (tun->dev->reg_state != NETREG_REGISTERED)
+ mask = EPOLLERR;
+
+ tun_put(tun);
+ 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++) {
+ struct page_frag *pfrag = ¤t->task_frag;
+ size_t fragsz = it->iov[i].iov_len;
+
+ if (fragsz == 0 || fragsz > PAGE_SIZE) {
+ err = -EINVAL;
+ goto free;
+ }
+
+ if (!skb_page_frag_refill(fragsz, pfrag, GFP_KERNEL)) {
+ err = -ENOMEM;
+ goto free;
+ }
+
+ skb_fill_page_desc(skb, i - 1, pfrag->page,
+ pfrag->offset, fragsz);
+ page_ref_inc(pfrag->page);
+ pfrag->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,
+ size_t prepad, size_t len,
+ size_t linear, int noblock)
+{
+ struct sock *sk = tfile->socket.sk;
+ struct sk_buff *skb;
+ int err;
+
+ /* Under a page? Don't bother with paged skb. */
+ if (prepad + len < PAGE_SIZE || !linear)
+ linear = len;
+
+ skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
+ &err, 0);
+ if (!skb)
+ return ERR_PTR(err);
+
+ skb_reserve(skb, prepad);
+ skb_put(skb, linear);
+ skb->data_len = len - linear;
+ skb->len += len - linear;
+
+ return skb;
+}
+
+static void tun_rx_batched(struct tun_struct *tun, struct tun_file *tfile,
+ struct sk_buff *skb, int more)
+{
+ struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
+ struct sk_buff_head process_queue;
+ u32 rx_batched = tun->rx_batched;
+ bool rcv = false;
+
+ if (!rx_batched || (!more && skb_queue_empty(queue))) {
+ local_bh_disable();
+ skb_record_rx_queue(skb, tfile->queue_index);
+ netif_receive_skb(skb);
+ local_bh_enable();
+ return;
+ }
+
+ spin_lock(&queue->lock);
+ if (!more || skb_queue_len(queue) == rx_batched) {
+ __skb_queue_head_init(&process_queue);
+ skb_queue_splice_tail_init(queue, &process_queue);
+ rcv = true;
+ } else {
+ __skb_queue_tail(queue, skb);
+ }
+ spin_unlock(&queue->lock);
+
+ if (rcv) {
+ struct sk_buff *nskb;
+
+ local_bh_disable();
+ while ((nskb = __skb_dequeue(&process_queue))) {
+ skb_record_rx_queue(nskb, tfile->queue_index);
+ netif_receive_skb(nskb);
+ }
+ skb_record_rx_queue(skb, tfile->queue_index);
+ netif_receive_skb(skb);
+ local_bh_enable();
+ }
+}
+
+static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile,
+ int len, int noblock, bool zerocopy)
+{
+ if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
+ return false;
+
+ if (tfile->socket.sk->sk_sndbuf != INT_MAX)
+ return false;
+
+ if (!noblock)
+ return false;
+
+ if (zerocopy)
+ return false;
+
+ if (SKB_DATA_ALIGN(len + TUN_RX_PAD) +
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE)
+ return false;
+
+ return true;
+}
+
+static struct sk_buff *tun_build_skb(struct tun_struct *tun,
+ struct tun_file *tfile,
+ struct iov_iter *from,
+ struct virtio_net_hdr *hdr,
+ int len, int *skb_xdp)
+{
+ struct page_frag *alloc_frag = ¤t->task_frag;
+ struct sk_buff *skb;
+ struct bpf_prog *xdp_prog;
+ int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ unsigned int delta = 0;
+ char *buf;
+ size_t copied;
+ int err, pad = TUN_RX_PAD;
+
+ rcu_read_lock();
+ xdp_prog = rcu_dereference(tun->xdp_prog);
+ if (xdp_prog)
+ pad += TUN_HEADROOM;
+ buflen += SKB_DATA_ALIGN(len + pad);
+ rcu_read_unlock();
+
+ alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES);
+ if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL)))
+ return ERR_PTR(-ENOMEM);
+
+ buf = (char *)page_address(alloc_frag->page) + alloc_frag->offset;
+ copied = copy_page_from_iter(alloc_frag->page,
+ alloc_frag->offset + pad,
+ len, from);
+ if (copied != len)
+ return ERR_PTR(-EFAULT);
+
+ /* There's a small window that XDP may be set after the check
+ * of xdp_prog above, this should be rare and for simplicity
+ * we do XDP on skb in case the headroom is not enough.
+ */
+ if (hdr->gso_type || !xdp_prog)
+ *skb_xdp = 1;
+ else
+ *skb_xdp = 0;
+
+ local_bh_disable();
+ rcu_read_lock();
+ xdp_prog = rcu_dereference(tun->xdp_prog);
+ if (xdp_prog && !*skb_xdp) {
+ struct xdp_buff xdp;
+ void *orig_data;
+ u32 act;
+
+ xdp.data_hard_start = buf;
+ xdp.data = buf + pad;
+ xdp_set_data_meta_invalid(&xdp);
+ xdp.data_end = xdp.data + len;
+ xdp.rxq = &tfile->xdp_rxq;
+ orig_data = xdp.data;
+ act = bpf_prog_run_xdp(xdp_prog, &xdp);
+
+ switch (act) {
+ case XDP_REDIRECT:
+ get_page(alloc_frag->page);
+ alloc_frag->offset += buflen;
+ err = xdp_do_redirect(tun->dev, &xdp, xdp_prog);
+ xdp_do_flush_map();
+ if (err)
+ goto err_redirect;
+ rcu_read_unlock();
+ local_bh_enable();
+ return NULL;
+ case XDP_TX:
+ get_page(alloc_frag->page);
+ alloc_frag->offset += buflen;
+ if (tun_xdp_tx(tun->dev, &xdp) < 0)
+ goto err_redirect;
+ rcu_read_unlock();
+ local_bh_enable();
+ return NULL;
+ case XDP_PASS:
+ delta = orig_data - xdp.data;
+ len = xdp.data_end - xdp.data;
+ break;
+ default:
+ bpf_warn_invalid_xdp_action(act);
+ /* fall through */
+ case XDP_ABORTED:
+ trace_xdp_exception(tun->dev, xdp_prog, act);
+ /* fall through */
+ case XDP_DROP:
+ goto err_xdp;
+ }
+ }
+
+ skb = build_skb(buf, buflen);
+ if (!skb) {
+ rcu_read_unlock();
+ local_bh_enable();
+ return ERR_PTR(-ENOMEM);
+ }
+
+ skb_reserve(skb, pad - delta);
+ skb_put(skb, len);
+ get_page(alloc_frag->page);
+ alloc_frag->offset += buflen;
+
+ rcu_read_unlock();
+ local_bh_enable();
+
+ return skb;
+
+err_redirect:
+ put_page(alloc_frag->page);
+err_xdp:
+ rcu_read_unlock();
+ local_bh_enable();
+ this_cpu_inc(tun->pcpu_stats->rx_dropped);
+ return NULL;
+}
+
+/* Get packet from user space buffer */
+static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
+ void *msg_control, struct iov_iter *from,
+ int noblock, bool more)
+{
+ 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;
+ struct virtio_net_hdr gso = { 0 };
+ struct tun_pcpu_stats *stats;
+ int good_linear;
+ int copylen;
+ bool zerocopy = false;
+ int err;
+ u32 rxhash = 0;
+ int skb_xdp = 1;
+ bool frags = tun_napi_frags_enabled(tfile);
+
+ if (!(tun->dev->flags & IFF_UP))
+ return -EIO;
+
+ if (!(tun->flags & IFF_NO_PI)) {
+ if (len < 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));
+ }
+
+ 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)))
+ return -EINVAL;
+ }
+
+ good_linear = SKB_MAX_HEAD(align);
+
+ if (msg_control) {
+ struct iov_iter i = *from;
+
+ /* There are 256 bytes to be copied in skb, so there is
+ * 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;
+ if (copylen > good_linear)
+ copylen = good_linear;
+ linear = copylen;
+ iov_iter_advance(&i, copylen);
+ if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS)
+ zerocopy = true;
+ }
+
+ 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.
+ */
+ skb = tun_build_skb(tun, tfile, from, &gso, len, &skb_xdp);
+ if (IS_ERR(skb)) {
+ this_cpu_inc(tun->pcpu_stats->rx_dropped);
+ return PTR_ERR(skb);
+ }
+ if (!skb)
+ return total_len;
+ } else {
+ if (!zerocopy) {
+ copylen = len;
+ if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
+ linear = good_linear;
+ else
+ linear = tun16_to_cpu(tun, gso.hdr_len);
+ }
+
+ 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);
+ }
+
+ if (zerocopy)
+ err = zerocopy_sg_from_iter(skb, from);
+ else
+ err = skb_copy_datagram_from_iter(skb, 0, from, len);
+
+ 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;
+ }
+ }
+
+ 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;
+ }
+
+ switch (tun->flags & TUN_TYPE_MASK) {
+ case IFF_TUN:
+ if (tun->flags & IFF_NO_PI) {
+ u8 ip_version = skb->len ? (skb->data[0] >> 4) : 0;
+
+ switch (ip_version) {
+ case 4:
+ pi.proto = htons(ETH_P_IP);
+ break;
+ case 6:
+ pi.proto = htons(ETH_P_IPV6);
+ break;
+ default:
+ this_cpu_inc(tun->pcpu_stats->rx_dropped);
+ kfree_skb(skb);
+ return -EINVAL;
+ }
+ }
+
+ skb_reset_mac_header(skb);
+ skb->protocol = pi.proto;
+ skb->dev = tun->dev;
+ break;
+ case IFF_TAP:
+ if (!frags)
+ skb->protocol = eth_type_trans(skb, tun->dev);
+ break;
+ }
+
+ /* copy skb_ubuf_info for callback when skb has no error */
+ if (zerocopy) {
+ skb_shinfo(skb)->destructor_arg = msg_control;
+ skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
+ skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
+ } else if (msg_control) {
+ struct ubuf_info *uarg = msg_control;
+ uarg->callback(uarg, false);
+ }
+
+ skb_reset_network_header(skb);
+ skb_probe_transport_header(skb, 0);
+
+ if (skb_xdp) {
+ struct bpf_prog *xdp_prog;
+ int ret;
+
+ local_bh_disable();
+ rcu_read_lock();
+ xdp_prog = rcu_dereference(tun->xdp_prog);
+ if (xdp_prog) {
+ ret = do_xdp_generic(xdp_prog, skb);
+ if (ret != XDP_PASS) {
+ rcu_read_unlock();
+ local_bh_enable();
+ return total_len;
+ }
+ }
+ rcu_read_unlock();
+ local_bh_enable();
+ }
+
+ /* Compute the costly rx hash only if needed for flow updates.
+ * We may get a very small possibility of OOO during switching, not
+ * worth to optimize.
+ */
+ if (!rcu_access_pointer(tun->steering_prog) && tun->numqueues > 1 &&
+ !tfile->detached)
+ rxhash = __skb_get_hash_symmetric(skb);
+
+ 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);
+ stats->rx_packets++;
+ stats->rx_bytes += len;
+ u64_stats_update_end(&stats->syncp);
+ put_cpu_ptr(stats);
+
+ if (rxhash)
+ tun_flow_update(tun, rxhash, tfile);
+
+ return total_len;
+}
+
+static ssize_t tun_chr_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct tun_file *tfile = file->private_data;
+ struct tun_struct *tun = tun_get(tfile);
+ ssize_t result;
+
+ if (!tun)
+ return -EBADFD;
+
+ result = tun_get_user(tun, tfile, NULL, from,
+ file->f_flags & O_NONBLOCK, false);
+
+ tun_put(tun);
+ return result;
+}
+
+static ssize_t tun_put_user_xdp(struct tun_struct *tun,
+ struct tun_file *tfile,
+ struct xdp_frame *xdp_frame,
+ struct iov_iter *iter)
+{
+ int vnet_hdr_sz = 0;
+ size_t size = xdp_frame->len;
+ struct tun_pcpu_stats *stats;
+ size_t ret;
+
+ 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 = copy_to_iter(xdp_frame->data, size, iter) + vnet_hdr_sz;
+
+ stats = get_cpu_ptr(tun->pcpu_stats);
+ u64_stats_update_begin(&stats->syncp);
+ stats->tx_packets++;
+ stats->tx_bytes += ret;
+ u64_stats_update_end(&stats->syncp);
+ put_cpu_ptr(tun->pcpu_stats);
+
+ return ret;
+}
+
+/* Put packet to the user space buffer */
+static ssize_t tun_put_user(struct tun_struct *tun,
+ struct tun_file *tfile,
+ struct sk_buff *skb,
+ struct iov_iter *iter)
+{
+ struct tun_pi pi = { 0, skb->protocol };
+ struct tun_pcpu_stats *stats;
+ ssize_t total;
+ int vlan_offset = 0;
+ int vlan_hlen = 0;
+ int vnet_hdr_sz = 0;
+
+ if (skb_vlan_tag_present(skb))
+ vlan_hlen = VLAN_HLEN;
+
+ if (tun->flags & IFF_VNET_HDR)
+ vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
+
+ total = skb->len + vlan_hlen + vnet_hdr_sz;
+
+ if (!(tun->flags & IFF_NO_PI)) {
+ if (iov_iter_count(iter) < sizeof(pi))
+ return -EINVAL;
+
+ total += sizeof(pi);
+ if (iov_iter_count(iter) < total) {
+ /* Packet will be striped */
+ pi.flags |= TUN_PKT_STRIP;
+ }
+
+ if (copy_to_iter(&pi, sizeof(pi), iter) != sizeof(pi))
+ return -EFAULT;
+ }
+
+ 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);
+ pr_err("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;
+
+ iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso));
+ }
+
+ if (vlan_hlen) {
+ int ret;
+ struct veth veth;
+
+ veth.h_vlan_proto = skb->vlan_proto;
+ veth.h_vlan_TCI = htons(skb_vlan_tag_get(skb));
+
+ vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
+
+ ret = skb_copy_datagram_iter(skb, 0, iter, vlan_offset);
+ if (ret || !iov_iter_count(iter))
+ goto done;
+
+ ret = copy_to_iter(&veth, sizeof(veth), iter);
+ if (ret != sizeof(veth) || !iov_iter_count(iter))
+ goto done;
+ }
+
+ skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
+
+done:
+ /* caller is in process context, */
+ stats = get_cpu_ptr(tun->pcpu_stats);
+ u64_stats_update_begin(&stats->syncp);
+ stats->tx_packets++;
+ stats->tx_bytes += skb->len + vlan_hlen;
+ u64_stats_update_end(&stats->syncp);
+ put_cpu_ptr(tun->pcpu_stats);
+
+ return total;
+}
+
+static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err)
+{
+ DECLARE_WAITQUEUE(wait, current);
+ void *ptr = NULL;
+ int error = 0;
+
+ ptr = ptr_ring_consume(&tfile->tx_ring);
+ if (ptr)
+ goto out;
+ if (noblock) {
+ error = -EAGAIN;
+ goto out;
+ }
+
+ add_wait_queue(&tfile->wq.wait, &wait);
+ current->state = TASK_INTERRUPTIBLE;
+
+ while (1) {
+ ptr = ptr_ring_consume(&tfile->tx_ring);
+ if (ptr)
+ break;
+ if (signal_pending(current)) {
+ error = -ERESTARTSYS;
+ break;
+ }
+ if (tfile->socket.sk->sk_shutdown & RCV_SHUTDOWN) {
+ error = -EFAULT;
+ break;
+ }
+
+ schedule();
+ }
+
+ current->state = TASK_RUNNING;
+ remove_wait_queue(&tfile->wq.wait, &wait);
+
+out:
+ *err = error;
+ return ptr;
+}
+
+static ssize_t tun_do_read(struct tun_struct *tun, struct tun_file *tfile,
+ struct iov_iter *to,
+ int noblock, void *ptr)
+{
+ ssize_t ret;
+ int err;
+
+ tun_debug(KERN_INFO, tun, "tun_do_read\n");
+
+ if (!iov_iter_count(to)) {
+ tun_ptr_free(ptr);
+ return 0;
+ }
+
+ if (!ptr) {
+ /* Read frames from ring */
+ ptr = tun_ring_recv(tfile, noblock, &err);
+ if (!ptr)
+ return err;
+ }
+
+ if (tun_is_xdp_frame(ptr)) {
+ struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
+
+ ret = tun_put_user_xdp(tun, tfile, xdpf, to);
+ xdp_return_frame(xdpf);
+ } else {
+ struct sk_buff *skb = ptr;
+
+ ret = tun_put_user(tun, tfile, skb, to);
+ if (unlikely(ret < 0))
+ kfree_skb(skb);
+ else
+ consume_skb(skb);
+ }
+
+ return ret;
+}
+
+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);
+ ssize_t len = iov_iter_count(to), ret;
+
+ if (!tun)
+ return -EBADFD;
+ ret = tun_do_read(tun, tfile, to, file->f_flags & O_NONBLOCK, NULL);
+ ret = min_t(ssize_t, ret, len);
+ if (ret > 0)
+ iocb->ki_pos = ret;
+ tun_put(tun);
+ return ret;
+}
+
+static void tun_prog_free(struct rcu_head *rcu)
+{
+ struct tun_prog *prog = container_of(rcu, struct tun_prog, rcu);
+
+ bpf_prog_destroy(prog->prog);
+ kfree(prog);
+}
+
+static int __tun_set_ebpf(struct tun_struct *tun,
+ struct tun_prog __rcu **prog_p,
+ struct bpf_prog *prog)
+{
+ struct tun_prog *old, *new = NULL;
+
+ if (prog) {
+ new = kmalloc(sizeof(*new), GFP_KERNEL);
+ if (!new)
+ return -ENOMEM;
+ new->prog = prog;
+ }
+
+ spin_lock_bh(&tun->lock);
+ old = rcu_dereference_protected(*prog_p,
+ lockdep_is_held(&tun->lock));
+ rcu_assign_pointer(*prog_p, new);
+ spin_unlock_bh(&tun->lock);
+
+ if (old)
+ call_rcu(&old->rcu, tun_prog_free);
+
+ return 0;
+}
+
+static void tun_free_netdev(struct net_device *dev)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+
+ BUG_ON(!(list_empty(&tun->disabled)));
+ free_percpu(tun->pcpu_stats);
+ tun_flow_uninit(tun);
+ security_tun_dev_free_security(tun->security);
+ __tun_set_ebpf(tun, &tun->steering_prog, NULL);
+ __tun_set_ebpf(tun, &tun->filter_prog, NULL);
+}
+
+static void tun_setup(struct net_device *dev)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+
+ tun->owner = INVALID_UID;
+ tun->group = INVALID_GID;
+ tun_default_link_ksettings(dev, &tun->link_ksettings);
+
+ dev->ethtool_ops = &tun_ethtool_ops;
+ dev->needs_free_netdev = true;
+ dev->priv_destructor = tun_free_netdev;
+ /* We prefer our own queue length */
+ dev->tx_queue_len = TUN_READQ_SIZE;
+}
+
+/* Trivial set of netlink ops to allow deleting tun or tap
+ * device with netlink.
+ */
+static int tun_validate(struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ NL_SET_ERR_MSG(extack,
+ "tun/tap creation via rtnetlink is not supported.");
+ return -EOPNOTSUPP;
+}
+
+static size_t tun_get_size(const struct net_device *dev)
+{
+ BUILD_BUG_ON(sizeof(u32) != sizeof(uid_t));
+ BUILD_BUG_ON(sizeof(u32) != sizeof(gid_t));
+
+ return nla_total_size(sizeof(uid_t)) + /* OWNER */
+ nla_total_size(sizeof(gid_t)) + /* GROUP */
+ nla_total_size(sizeof(u8)) + /* TYPE */
+ nla_total_size(sizeof(u8)) + /* PI */
+ nla_total_size(sizeof(u8)) + /* VNET_HDR */
+ nla_total_size(sizeof(u8)) + /* PERSIST */
+ nla_total_size(sizeof(u8)) + /* MULTI_QUEUE */
+ nla_total_size(sizeof(u32)) + /* NUM_QUEUES */
+ nla_total_size(sizeof(u32)) + /* NUM_DISABLED_QUEUES */
+ 0;
+}
+
+static int tun_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+
+ if (nla_put_u8(skb, IFLA_TUN_TYPE, tun->flags & TUN_TYPE_MASK))
+ goto nla_put_failure;
+ if (uid_valid(tun->owner) &&
+ nla_put_u32(skb, IFLA_TUN_OWNER,
+ from_kuid_munged(current_user_ns(), tun->owner)))
+ goto nla_put_failure;
+ if (gid_valid(tun->group) &&
+ nla_put_u32(skb, IFLA_TUN_GROUP,
+ from_kgid_munged(current_user_ns(), tun->group)))
+ goto nla_put_failure;
+ if (nla_put_u8(skb, IFLA_TUN_PI, !(tun->flags & IFF_NO_PI)))
+ goto nla_put_failure;
+ if (nla_put_u8(skb, IFLA_TUN_VNET_HDR, !!(tun->flags & IFF_VNET_HDR)))
+ goto nla_put_failure;
+ if (nla_put_u8(skb, IFLA_TUN_PERSIST, !!(tun->flags & IFF_PERSIST)))
+ goto nla_put_failure;
+ if (nla_put_u8(skb, IFLA_TUN_MULTI_QUEUE,
+ !!(tun->flags & IFF_MULTI_QUEUE)))
+ goto nla_put_failure;
+ if (tun->flags & IFF_MULTI_QUEUE) {
+ if (nla_put_u32(skb, IFLA_TUN_NUM_QUEUES, tun->numqueues))
+ goto nla_put_failure;
+ if (nla_put_u32(skb, IFLA_TUN_NUM_DISABLED_QUEUES,
+ tun->numdisabled))
+ goto nla_put_failure;
+ }
+
+ return 0;
+
+nla_put_failure:
+ return -EMSGSIZE;
+}
+
+static struct rtnl_link_ops tun_link_ops __read_mostly = {
+ .kind = DRV_NAME,
+ .priv_size = sizeof(struct tun_struct),
+ .setup = tun_setup,
+ .validate = tun_validate,
+ .get_size = tun_get_size,
+ .fill_info = tun_fill_info,
+};
+
+static void tun_sock_write_space(struct sock *sk)
+{
+ struct tun_file *tfile;
+ wait_queue_head_t *wqueue;
+
+ if (!sock_writeable(sk))
+ return;
+
+ if (!test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags))
+ return;
+
+ wqueue = sk_sleep(sk);
+ if (wqueue && waitqueue_active(wqueue))
+ wake_up_interruptible_sync_poll(wqueue, EPOLLOUT |
+ EPOLLWRNORM | EPOLLWRBAND);
+
+ tfile = container_of(sk, struct tun_file, sk);
+ kill_fasync(&tfile->fasync, SIGIO, POLL_OUT);
+}
+
+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);
+
+ if (!tun)
+ return -EBADFD;
+
+ ret = tun_get_user(tun, tfile, m->msg_control, &m->msg_iter,
+ m->msg_flags & MSG_DONTWAIT,
+ m->msg_flags & MSG_MORE);
+ tun_put(tun);
+ return ret;
+}
+
+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);
+ void *ptr = m->msg_control;
+ int ret;
+
+ if (!tun) {
+ ret = -EBADFD;
+ goto out_free;
+ }
+
+ if (flags & ~(MSG_DONTWAIT|MSG_TRUNC|MSG_ERRQUEUE)) {
+ ret = -EINVAL;
+ goto out_put_tun;
+ }
+ if (flags & MSG_ERRQUEUE) {
+ ret = sock_recv_errqueue(sock->sk, m, total_len,
+ SOL_PACKET, TUN_TX_TIMESTAMP);
+ goto out;
+ }
+ ret = tun_do_read(tun, tfile, &m->msg_iter, flags & MSG_DONTWAIT, ptr);
+ if (ret > (ssize_t)total_len) {
+ m->msg_flags |= MSG_TRUNC;
+ ret = flags & MSG_TRUNC ? ret : total_len;
+ }
+out:
+ tun_put(tun);
+ return ret;
+
+out_put_tun:
+ tun_put(tun);
+out_free:
+ tun_ptr_free(ptr);
+ return ret;
+}
+
+static int tun_ptr_peek_len(void *ptr)
+{
+ if (likely(ptr)) {
+ if (tun_is_xdp_frame(ptr)) {
+ struct xdp_frame *xdpf = tun_ptr_to_xdp(ptr);
+
+ return xdpf->len;
+ }
+ return __skb_array_len_with_tag(ptr);
+ } else {
+ return 0;
+ }
+}
+
+static int tun_peek_len(struct socket *sock)
+{
+ struct tun_file *tfile = container_of(sock, struct tun_file, socket);
+ struct tun_struct *tun;
+ int ret = 0;
+
+ tun = tun_get(tfile);
+ if (!tun)
+ return 0;
+
+ ret = PTR_RING_PEEK_CALL(&tfile->tx_ring, tun_ptr_peek_len);
+ tun_put(tun);
+
+ return ret;
+}
+
+/* Ops structure to mimic raw sockets with tun */
+static const struct proto_ops tun_socket_ops = {
+ .peek_len = tun_peek_len,
+ .sendmsg = tun_sendmsg,
+ .recvmsg = tun_recvmsg,
+};
+
+static struct proto tun_proto = {
+ .name = "tun",
+ .owner = THIS_MODULE,
+ .obj_size = sizeof(struct tun_file),
+};
+
+static int tun_flags(struct tun_struct *tun)
+{
+ return tun->flags & (TUN_FEATURES | IFF_PERSIST | IFF_TUN | IFF_TAP);
+}
+
+static ssize_t tun_show_flags(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct tun_struct *tun = netdev_priv(to_net_dev(dev));
+ return sprintf(buf, "0x%x\n", tun_flags(tun));
+}
+
+static ssize_t tun_show_owner(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct tun_struct *tun = netdev_priv(to_net_dev(dev));
+ return uid_valid(tun->owner)?
+ sprintf(buf, "%u\n",
+ from_kuid_munged(current_user_ns(), tun->owner)):
+ sprintf(buf, "-1\n");
+}
+
+static ssize_t tun_show_group(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct tun_struct *tun = netdev_priv(to_net_dev(dev));
+ return gid_valid(tun->group) ?
+ sprintf(buf, "%u\n",
+ from_kgid_munged(current_user_ns(), tun->group)):
+ sprintf(buf, "-1\n");
+}
+
+static DEVICE_ATTR(tun_flags, 0444, tun_show_flags, NULL);
+static DEVICE_ATTR(owner, 0444, tun_show_owner, NULL);
+static DEVICE_ATTR(group, 0444, tun_show_group, NULL);
+
+static struct attribute *tun_dev_attrs[] = {
+ &dev_attr_tun_flags.attr,
+ &dev_attr_owner.attr,
+ &dev_attr_group.attr,
+ NULL
+};
+
+static const struct attribute_group tun_attr_group = {
+ .attrs = tun_dev_attrs
+};
+
+static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
+{
+ struct tun_struct *tun;
+ struct tun_file *tfile = file->private_data;
+ struct net_device *dev;
+ int err;
+
+ 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)
+ return -EBUSY;
+ if ((ifr->ifr_flags & IFF_TUN) && dev->netdev_ops == &tun_netdev_ops)
+ tun = netdev_priv(dev);
+ else if ((ifr->ifr_flags & IFF_TAP) && dev->netdev_ops == &tap_netdev_ops)
+ tun = netdev_priv(dev);
+ else
+ return -EINVAL;
+
+ if (!!(ifr->ifr_flags & IFF_MULTI_QUEUE) !=
+ !!(tun->flags & IFF_MULTI_QUEUE))
+ return -EINVAL;
+
+ if (tun_not_capable(tun))
+ return -EPERM;
+ err = security_tun_dev_open(tun->security);
+ if (err < 0)
+ return err;
+
+ err = tun_attach(tun, file, ifr->ifr_flags & IFF_NOFILTER,
+ ifr->ifr_flags & IFF_NAPI,
+ ifr->ifr_flags & IFF_NAPI_FRAGS);
+ if (err < 0)
+ return err;
+
+ if (tun->flags & IFF_MULTI_QUEUE &&
+ (tun->numqueues + tun->numdisabled > 1)) {
+ /* One or more queue has already been attached, no need
+ * to initialize the device again.
+ */
+ netdev_state_change(dev);
+ return 0;
+ }
+
+ tun->flags = (tun->flags & ~TUN_FEATURES) |
+ (ifr->ifr_flags & TUN_FEATURES);
+
+ netdev_state_change(dev);
+ } else {
+ char *name;
+ unsigned long flags = 0;
+ int queues = ifr->ifr_flags & IFF_MULTI_QUEUE ?
+ MAX_TAP_QUEUES : 1;
+
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+ return -EPERM;
+ err = security_tun_dev_create();
+ if (err < 0)
+ return err;
+
+ /* Set dev type */
+ if (ifr->ifr_flags & IFF_TUN) {
+ /* TUN device */
+ flags |= IFF_TUN;
+ name = "tun%d";
+ } else if (ifr->ifr_flags & IFF_TAP) {
+ /* TAP device */
+ flags |= IFF_TAP;
+ name = "tap%d";
+ } else
+ return -EINVAL;
+
+ if (*ifr->ifr_name)
+ name = ifr->ifr_name;
+
+ dev = alloc_netdev_mqs(sizeof(struct tun_struct), name,
+ NET_NAME_UNKNOWN, tun_setup, queues,
+ queues);
+
+ if (!dev)
+ return -ENOMEM;
+ err = dev_get_valid_name(net, dev, name);
+ if (err < 0)
+ goto err_free_dev;
+
+ dev_net_set(dev, net);
+ dev->rtnl_link_ops = &tun_link_ops;
+ dev->ifindex = tfile->ifindex;
+ dev->sysfs_groups[0] = &tun_attr_group;
+
+ tun = netdev_priv(dev);
+ tun->dev = dev;
+ tun->flags = flags;
+ tun->txflt.count = 0;
+ tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
+
+ tun->align = NET_SKB_PAD;
+ tun->filter_attached = false;
+ tun->sndbuf = tfile->socket.sk->sk_sndbuf;
+ tun->rx_batched = 0;
+ RCU_INIT_POINTER(tun->steering_prog, NULL);
+
+ tun->pcpu_stats = netdev_alloc_pcpu_stats(struct tun_pcpu_stats);
+ if (!tun->pcpu_stats) {
+ err = -ENOMEM;
+ goto err_free_dev;
+ }
+
+ spin_lock_init(&tun->lock);
+
+ err = security_tun_dev_alloc_security(&tun->security);
+ if (err < 0)
+ goto err_free_stat;
+
+ tun_net_init(dev);
+ tun_flow_init(tun);
+
+ dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
+ TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
+ NETIF_F_HW_VLAN_STAG_TX;
+ dev->features = dev->hw_features | NETIF_F_LLTX;
+ dev->vlan_features = dev->features &
+ ~(NETIF_F_HW_VLAN_CTAG_TX |
+ NETIF_F_HW_VLAN_STAG_TX);
+
+ tun->flags = (tun->flags & ~TUN_FEATURES) |
+ (ifr->ifr_flags & TUN_FEATURES);
+
+ INIT_LIST_HEAD(&tun->disabled);
+ err = tun_attach(tun, file, false, ifr->ifr_flags & IFF_NAPI,
+ ifr->ifr_flags & IFF_NAPI_FRAGS);
+ if (err < 0)
+ goto err_free_flow;
+
+ err = register_netdevice(tun->dev);
+ if (err < 0)
+ goto err_detach;
+ }
+
+ netif_carrier_on(tun->dev);
+
+ tun_debug(KERN_INFO, tun, "tun_set_iff\n");
+
+ /* Make sure persistent devices do not get stuck in
+ * xoff state.
+ */
+ if (netif_running(tun->dev))
+ netif_tx_wake_all_queues(tun->dev);
+
+ strcpy(ifr->ifr_name, tun->dev->name);
+ return 0;
+
+err_detach:
+ tun_detach_all(dev);
+ /* register_netdevice() already called tun_free_netdev() */
+ goto err_free_dev;
+
+err_free_flow:
+ tun_flow_uninit(tun);
+ security_tun_dev_free_security(tun->security);
+err_free_stat:
+ free_percpu(tun->pcpu_stats);
+err_free_dev:
+ free_netdev(dev);
+ return err;
+}
+
+static void tun_get_iff(struct net *net, struct tun_struct *tun,
+ struct ifreq *ifr)
+{
+ tun_debug(KERN_INFO, tun, "tun_get_iff\n");
+
+ strcpy(ifr->ifr_name, tun->dev->name);
+
+ ifr->ifr_flags = tun_flags(tun);
+
+}
+
+/* This is like a cut-down ethtool ops, except done via tun fd so no
+ * privs required. */
+static int set_offload(struct tun_struct *tun, unsigned long arg)
+{
+ netdev_features_t features = 0;
+
+ if (arg & TUN_F_CSUM) {
+ features |= NETIF_F_HW_CSUM;
+ arg &= ~TUN_F_CSUM;
+
+ if (arg & (TUN_F_TSO4|TUN_F_TSO6)) {
+ if (arg & TUN_F_TSO_ECN) {
+ features |= NETIF_F_TSO_ECN;
+ arg &= ~TUN_F_TSO_ECN;
+ }
+ if (arg & TUN_F_TSO4)
+ features |= NETIF_F_TSO;
+ if (arg & TUN_F_TSO6)
+ features |= NETIF_F_TSO6;
+ arg &= ~(TUN_F_TSO4|TUN_F_TSO6);
+ }
+
+ arg &= ~TUN_F_UFO;
+ }
+
+ /* This gives the user a way to test for new features in future by
+ * trying to set them. */
+ if (arg)
+ return -EINVAL;
+
+ tun->set_features = features;
+ tun->dev->wanted_features &= ~TUN_USER_FEATURES;
+ tun->dev->wanted_features |= features;
+ netdev_update_features(tun->dev);
+
+ return 0;
+}
+
+static void tun_detach_filter(struct tun_struct *tun, int n)
+{
+ int i;
+ struct tun_file *tfile;
+
+ for (i = 0; i < n; i++) {
+ tfile = rtnl_dereference(tun->tfiles[i]);
+ lock_sock(tfile->socket.sk);
+ sk_detach_filter(tfile->socket.sk);
+ release_sock(tfile->socket.sk);
+ }
+
+ tun->filter_attached = false;
+}
+
+static int tun_attach_filter(struct tun_struct *tun)
+{
+ int i, ret = 0;
+ struct tun_file *tfile;
+
+ for (i = 0; i < tun->numqueues; i++) {
+ tfile = rtnl_dereference(tun->tfiles[i]);
+ lock_sock(tfile->socket.sk);
+ ret = sk_attach_filter(&tun->fprog, tfile->socket.sk);
+ release_sock(tfile->socket.sk);
+ if (ret) {
+ tun_detach_filter(tun, i);
+ return ret;
+ }
+ }
+
+ tun->filter_attached = true;
+ return ret;
+}
+
+static void tun_set_sndbuf(struct tun_struct *tun)
+{
+ struct tun_file *tfile;
+ int i;
+
+ for (i = 0; i < tun->numqueues; i++) {
+ tfile = rtnl_dereference(tun->tfiles[i]);
+ tfile->socket.sk->sk_sndbuf = tun->sndbuf;
+ }
+}
+
+static int tun_set_queue(struct file *file, struct ifreq *ifr)
+{
+ struct tun_file *tfile = file->private_data;
+ struct tun_struct *tun;
+ int ret = 0;
+
+ rtnl_lock();
+
+ if (ifr->ifr_flags & IFF_ATTACH_QUEUE) {
+ tun = tfile->detached;
+ if (!tun) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+ ret = security_tun_dev_attach_queue(tun->security);
+ if (ret < 0)
+ goto unlock;
+ ret = tun_attach(tun, file, false, tun->flags & IFF_NAPI,
+ tun->flags & IFF_NAPI_FRAGS);
+ } else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
+ tun = rtnl_dereference(tfile->tun);
+ if (!tun || !(tun->flags & IFF_MULTI_QUEUE) || tfile->detached)
+ ret = -EINVAL;
+ else
+ __tun_detach(tfile, false);
+ } else
+ ret = -EINVAL;
+
+ if (ret >= 0)
+ netdev_state_change(tun->dev);
+
+unlock:
+ rtnl_unlock();
+ return ret;
+}
+
+static int tun_set_ebpf(struct tun_struct *tun, struct tun_prog **prog_p,
+ void __user *data)
+{
+ struct bpf_prog *prog;
+ int fd;
+
+ if (copy_from_user(&fd, data, sizeof(fd)))
+ return -EFAULT;
+
+ if (fd == -1) {
+ prog = NULL;
+ } else {
+ prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+ }
+
+ return __tun_set_ebpf(tun, prog_p, prog);
+}
+
+static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg, int ifreq_len)
+{
+ struct tun_file *tfile = file->private_data;
+ struct net *net = sock_net(&tfile->sk);
+ struct tun_struct *tun;
+ void __user* argp = (void __user*)arg;
+ struct ifreq ifr;
+ kuid_t owner;
+ kgid_t group;
+ int sndbuf;
+ int vnet_hdr_sz;
+ unsigned int ifindex;
+ int le;
+ int ret;
+ bool do_notify = false;
+
+ if (cmd == TUNSETIFF || cmd == TUNSETQUEUE ||
+ (_IOC_TYPE(cmd) == SOCK_IOC_TYPE && cmd != SIOCGSKNS)) {
+ if (copy_from_user(&ifr, argp, ifreq_len))
+ return -EFAULT;
+ } else {
+ memset(&ifr, 0, sizeof(ifr));
+ }
+ if (cmd == TUNGETFEATURES) {
+ /* Currently this just means: "what IFF flags are valid?".
+ * This is needed because we never checked for invalid flags on
+ * TUNSETIFF.
+ */
+ return put_user(IFF_TUN | IFF_TAP | TUN_FEATURES,
+ (unsigned int __user*)argp);
+ } else if (cmd == TUNSETQUEUE) {
+ return tun_set_queue(file, &ifr);
+ } else if (cmd == SIOCGSKNS) {
+ if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+ return -EPERM;
+ return open_related_ns(&net->ns, get_net_ns);
+ }
+
+ ret = 0;
+ rtnl_lock();
+
+ tun = tun_get(tfile);
+ if (cmd == TUNSETIFF) {
+ ret = -EEXIST;
+ if (tun)
+ goto unlock;
+
+ ifr.ifr_name[IFNAMSIZ-1] = '\0';
+
+ ret = tun_set_iff(net, file, &ifr);
+
+ if (ret)
+ goto unlock;
+
+ if (copy_to_user(argp, &ifr, ifreq_len))
+ ret = -EFAULT;
+ goto unlock;
+ }
+ if (cmd == TUNSETIFINDEX) {
+ ret = -EPERM;
+ if (tun)
+ goto unlock;
+
+ ret = -EFAULT;
+ if (copy_from_user(&ifindex, argp, sizeof(ifindex)))
+ goto unlock;
+
+ ret = 0;
+ tfile->ifindex = ifindex;
+ goto unlock;
+ }
+
+ ret = -EBADFD;
+ if (!tun)
+ goto unlock;
+
+ tun_debug(KERN_INFO, tun, "tun_chr_ioctl cmd %u\n", cmd);
+
+ ret = 0;
+ switch (cmd) {
+ case TUNGETIFF:
+ tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
+
+ if (tfile->detached)
+ ifr.ifr_flags |= IFF_DETACH_QUEUE;
+ if (!tfile->socket.sk->sk_filter)
+ ifr.ifr_flags |= IFF_NOFILTER;
+
+ if (copy_to_user(argp, &ifr, ifreq_len))
+ ret = -EFAULT;
+ break;
+
+ case TUNSETNOCSUM:
+ /* Disable/Enable checksum */
+
+ /* [unimplemented] */
+ tun_debug(KERN_INFO, tun, "ignored: set checksum %s\n",
+ arg ? "disabled" : "enabled");
+ break;
+
+ case TUNSETPERSIST:
+ /* Disable/Enable persist mode. Keep an extra reference to the
+ * module to prevent the module being unprobed.
+ */
+ if (arg && !(tun->flags & IFF_PERSIST)) {
+ tun->flags |= IFF_PERSIST;
+ __module_get(THIS_MODULE);
+ do_notify = true;
+ }
+ if (!arg && (tun->flags & IFF_PERSIST)) {
+ tun->flags &= ~IFF_PERSIST;
+ module_put(THIS_MODULE);
+ do_notify = true;
+ }
+
+ tun_debug(KERN_INFO, tun, "persist %s\n",
+ arg ? "enabled" : "disabled");
+ break;
+
+ case TUNSETOWNER:
+ /* Set owner of the device */
+ owner = make_kuid(current_user_ns(), arg);
+ if (!uid_valid(owner)) {
+ ret = -EINVAL;
+ break;
+ }
+ tun->owner = owner;
+ do_notify = true;
+ tun_debug(KERN_INFO, tun, "owner set to %u\n",
+ from_kuid(&init_user_ns, tun->owner));
+ break;
+
+ case TUNSETGROUP:
+ /* Set group of the device */
+ group = make_kgid(current_user_ns(), arg);
+ if (!gid_valid(group)) {
+ ret = -EINVAL;
+ break;
+ }
+ tun->group = group;
+ do_notify = true;
+ tun_debug(KERN_INFO, tun, "group set to %u\n",
+ from_kgid(&init_user_ns, tun->group));
+ break;
+
+ case TUNSETLINK:
+ /* Only allow setting the type when the interface is down */
+ if (tun->dev->flags & IFF_UP) {
+ tun_debug(KERN_INFO, tun,
+ "Linktype set failed because interface is up\n");
+ ret = -EBUSY;
+ } else {
+ tun->dev->type = (int) arg;
+ tun_debug(KERN_INFO, tun, "linktype set to %d\n",
+ tun->dev->type);
+ ret = 0;
+ }
+ break;
+
+#ifdef TUN_DEBUG
+ case TUNSETDEBUG:
+ tun->debug = arg;
+ break;
+#endif
+ case TUNSETOFFLOAD:
+ ret = set_offload(tun, arg);
+ break;
+
+ case TUNSETTXFILTER:
+ /* Can be set only for TAPs */
+ ret = -EINVAL;
+ if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
+ break;
+ ret = update_filter(&tun->txflt, (void __user *)arg);
+ break;
+
+ case SIOCGIFHWADDR:
+ /* Get hw address */
+ memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN);
+ ifr.ifr_hwaddr.sa_family = tun->dev->type;
+ if (copy_to_user(argp, &ifr, ifreq_len))
+ ret = -EFAULT;
+ break;
+
+ case SIOCSIFHWADDR:
+ /* Set hw address */
+ tun_debug(KERN_DEBUG, tun, "set hw address: %pM\n",
+ ifr.ifr_hwaddr.sa_data);
+
+ ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
+ break;
+
+ case TUNGETSNDBUF:
+ sndbuf = tfile->socket.sk->sk_sndbuf;
+ if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
+ ret = -EFAULT;
+ break;
+
+ case TUNSETSNDBUF:
+ if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
+ ret = -EFAULT;
+ break;
+ }
+ if (sndbuf <= 0) {
+ ret = -EINVAL;
+ break;
+ }
+
+ tun->sndbuf = sndbuf;
+ 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;
+ if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
+ break;
+ ret = -EFAULT;
+ if (copy_from_user(&tun->fprog, argp, sizeof(tun->fprog)))
+ break;
+
+ ret = tun_attach_filter(tun);
+ break;
+
+ case TUNDETACHFILTER:
+ /* Can be set only for TAPs */
+ ret = -EINVAL;
+ if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
+ break;
+ ret = 0;
+ tun_detach_filter(tun, tun->numqueues);
+ break;
+
+ case TUNGETFILTER:
+ ret = -EINVAL;
+ if ((tun->flags & TUN_TYPE_MASK) != IFF_TAP)
+ break;
+ ret = -EFAULT;
+ if (copy_to_user(argp, &tun->fprog, sizeof(tun->fprog)))
+ break;
+ ret = 0;
+ break;
+
+ case TUNSETSTEERINGEBPF:
+ ret = tun_set_ebpf(tun, &tun->steering_prog, argp);
+ break;
+
+ case TUNSETFILTEREBPF:
+ ret = tun_set_ebpf(tun, &tun->filter_prog, argp);
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ if (do_notify)
+ netdev_state_change(tun->dev);
+
+unlock:
+ rtnl_unlock();
+ if (tun)
+ tun_put(tun);
+ return ret;
+}
+
+static long tun_chr_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ return __tun_chr_ioctl(file, cmd, arg, sizeof (struct ifreq));
+}
+
+#ifdef CONFIG_COMPAT
+static long tun_chr_compat_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ switch (cmd) {
+ case TUNSETIFF:
+ case TUNGETIFF:
+ case TUNSETTXFILTER:
+ case TUNGETSNDBUF:
+ case TUNSETSNDBUF:
+ case SIOCGIFHWADDR:
+ case SIOCSIFHWADDR:
+ arg = (unsigned long)compat_ptr(arg);
+ break;
+ default:
+ arg = (compat_ulong_t)arg;
+ break;
+ }
+
+ /*
+ * compat_ifreq is shorter than ifreq, so we must not access beyond
+ * the end of that structure. All fields that are used in this
+ * driver are compatible though, we don't need to convert the
+ * contents.
+ */
+ return __tun_chr_ioctl(file, cmd, arg, sizeof(struct compat_ifreq));
+}
+#endif /* CONFIG_COMPAT */
+
+static int tun_chr_fasync(int fd, struct file *file, int on)
+{
+ struct tun_file *tfile = file->private_data;
+ int ret;
+
+ if ((ret = fasync_helper(fd, file, on, &tfile->fasync)) < 0)
+ goto out;
+
+ if (on) {
+ __f_setown(file, task_pid(current), PIDTYPE_TGID, 0);
+ tfile->flags |= TUN_FASYNC;
+ } else
+ tfile->flags &= ~TUN_FASYNC;
+ ret = 0;
+out:
+ return ret;
+}
+
+static int tun_chr_open(struct inode *inode, struct file * file)
+{
+ struct net *net = current->nsproxy->net_ns;
+ struct tun_file *tfile;
+
+ DBG1(KERN_INFO, "tunX: tun_chr_open\n");
+
+ tfile = (struct tun_file *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
+ &tun_proto, 0);
+ if (!tfile)
+ return -ENOMEM;
+ if (ptr_ring_init(&tfile->tx_ring, 0, GFP_KERNEL)) {
+ sk_free(&tfile->sk);
+ return -ENOMEM;
+ }
+
+ mutex_init(&tfile->napi_mutex);
+ RCU_INIT_POINTER(tfile->tun, NULL);
+ tfile->flags = 0;
+ tfile->ifindex = 0;
+
+ init_waitqueue_head(&tfile->wq.wait);
+ RCU_INIT_POINTER(tfile->socket.wq, &tfile->wq);
+
+ tfile->socket.file = file;
+ tfile->socket.ops = &tun_socket_ops;
+
+ sock_init_data(&tfile->socket, &tfile->sk);
+
+ tfile->sk.sk_write_space = tun_sock_write_space;
+ tfile->sk.sk_sndbuf = INT_MAX;
+
+ file->private_data = tfile;
+ INIT_LIST_HEAD(&tfile->next);
+
+ sock_set_flag(&tfile->sk, SOCK_ZEROCOPY);
+
+ return 0;
+}
+
+static int tun_chr_close(struct inode *inode, struct file *file)
+{
+ struct tun_file *tfile = file->private_data;
+
+ tun_detach(tfile, true);
+
+ return 0;
+}
+
+#ifdef CONFIG_PROC_FS
+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(tfile);
+ if (tun)
+ tun_get_iff(current->nsproxy->net_ns, tun, &ifr);
+ rtnl_unlock();
+
+ if (tun)
+ tun_put(tun);
+
+ seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
+}
+#endif
+
+static const struct file_operations tun_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .read_iter = tun_chr_read_iter,
+ .write_iter = tun_chr_write_iter,
+ .poll = tun_chr_poll,
+ .unlocked_ioctl = tun_chr_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = tun_chr_compat_ioctl,
+#endif
+ .open = tun_chr_open,
+ .release = tun_chr_close,
+ .fasync = tun_chr_fasync,
+#ifdef CONFIG_PROC_FS
+ .show_fdinfo = tun_chr_show_fdinfo,
+#endif
+};
+
+static struct miscdevice tun_miscdev = {
+ .minor = TUN_MINOR,
+ .name = "tun",
+ .nodename = "net/tun",
+ .fops = &tun_fops,
+};
+
+/* ethtool interface */
+
+static void tun_default_link_ksettings(struct net_device *dev,
+ struct ethtool_link_ksettings *cmd)
+{
+ ethtool_link_ksettings_zero_link_mode(cmd, supported);
+ ethtool_link_ksettings_zero_link_mode(cmd, advertising);
+ cmd->base.speed = SPEED_10;
+ cmd->base.duplex = DUPLEX_FULL;
+ cmd->base.port = PORT_TP;
+ cmd->base.phy_address = 0;
+ cmd->base.autoneg = AUTONEG_DISABLE;
+}
+
+static int tun_get_link_ksettings(struct net_device *dev,
+ struct ethtool_link_ksettings *cmd)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+
+ memcpy(cmd, &tun->link_ksettings, sizeof(*cmd));
+ return 0;
+}
+
+static int tun_set_link_ksettings(struct net_device *dev,
+ const struct ethtool_link_ksettings *cmd)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+
+ memcpy(&tun->link_ksettings, cmd, sizeof(*cmd));
+ return 0;
+}
+
+static void tun_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+
+ strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
+ strlcpy(info->version, DRV_VERSION, sizeof(info->version));
+
+ switch (tun->flags & TUN_TYPE_MASK) {
+ case IFF_TUN:
+ strlcpy(info->bus_info, "tun", sizeof(info->bus_info));
+ break;
+ case IFF_TAP:
+ strlcpy(info->bus_info, "tap", sizeof(info->bus_info));
+ break;
+ }
+}
+
+static u32 tun_get_msglevel(struct net_device *dev)
+{
+#ifdef TUN_DEBUG
+ struct tun_struct *tun = netdev_priv(dev);
+ return tun->debug;
+#else
+ return -EOPNOTSUPP;
+#endif
+}
+
+static void tun_set_msglevel(struct net_device *dev, u32 value)
+{
+#ifdef TUN_DEBUG
+ struct tun_struct *tun = netdev_priv(dev);
+ tun->debug = value;
+#endif
+}
+
+static int tun_get_coalesce(struct net_device *dev,
+ struct ethtool_coalesce *ec)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+
+ ec->rx_max_coalesced_frames = tun->rx_batched;
+
+ return 0;
+}
+
+static int tun_set_coalesce(struct net_device *dev,
+ struct ethtool_coalesce *ec)
+{
+ struct tun_struct *tun = netdev_priv(dev);
+
+ if (ec->rx_max_coalesced_frames > NAPI_POLL_WEIGHT)
+ tun->rx_batched = NAPI_POLL_WEIGHT;
+ else
+ tun->rx_batched = ec->rx_max_coalesced_frames;
+
+ return 0;
+}
+
+static const struct ethtool_ops tun_ethtool_ops = {
+ .get_drvinfo = tun_get_drvinfo,
+ .get_msglevel = tun_get_msglevel,
+ .set_msglevel = tun_set_msglevel,
+ .get_link = ethtool_op_get_link,
+ .get_ts_info = ethtool_op_get_ts_info,
+ .get_coalesce = tun_get_coalesce,
+ .set_coalesce = tun_set_coalesce,
+ .get_link_ksettings = tun_get_link_ksettings,
+ .set_link_ksettings = tun_set_link_ksettings,
+};
+
+static int tun_queue_resize(struct tun_struct *tun)
+{
+ struct net_device *dev = tun->dev;
+ struct tun_file *tfile;
+ struct ptr_ring **rings;
+ int n = tun->numqueues + tun->numdisabled;
+ int ret, i;
+
+ rings = kmalloc_array(n, sizeof(*rings), GFP_KERNEL);
+ if (!rings)
+ return -ENOMEM;
+
+ for (i = 0; i < tun->numqueues; i++) {
+ tfile = rtnl_dereference(tun->tfiles[i]);
+ rings[i] = &tfile->tx_ring;
+ }
+ list_for_each_entry(tfile, &tun->disabled, next)
+ rings[i++] = &tfile->tx_ring;
+
+ ret = ptr_ring_resize_multiple(rings, n,
+ dev->tx_queue_len, GFP_KERNEL,
+ tun_ptr_free);
+
+ kfree(rings);
+ return ret;
+}
+
+static int tun_device_event(struct notifier_block *unused,
+ unsigned long event, void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+ struct tun_struct *tun = netdev_priv(dev);
+
+ if (dev->rtnl_link_ops != &tun_link_ops)
+ return NOTIFY_DONE;
+
+ switch (event) {
+ case NETDEV_CHANGE_TX_QUEUE_LEN:
+ if (tun_queue_resize(tun))
+ return NOTIFY_BAD;
+ break;
+ default:
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block tun_notifier_block __read_mostly = {
+ .notifier_call = tun_device_event,
+};
+
+static int __init tun_init(void)
+{
+ int ret = 0;
+
+ pr_info("%s, %s\n", DRV_DESCRIPTION, DRV_VERSION);
+
+ ret = rtnl_link_register(&tun_link_ops);
+ if (ret) {
+ pr_err("Can't register link_ops\n");
+ goto err_linkops;
+ }
+
+ ret = misc_register(&tun_miscdev);
+ if (ret) {
+ pr_err("Can't register misc device %d\n", TUN_MINOR);
+ goto err_misc;
+ }
+
+ ret = register_netdevice_notifier(&tun_notifier_block);
+ if (ret) {
+ pr_err("Can't register netdevice notifier\n");
+ goto err_notifier;
+ }
+
+ return 0;
+
+err_notifier:
+ misc_deregister(&tun_miscdev);
+err_misc:
+ rtnl_link_unregister(&tun_link_ops);
+err_linkops:
+ return ret;
+}
+
+static void tun_cleanup(void)
+{
+ misc_deregister(&tun_miscdev);
+ rtnl_link_unregister(&tun_link_ops);
+ unregister_netdevice_notifier(&tun_notifier_block);
+}
+
+/* Get an underlying socket object from tun file. Returns error unless file is
+ * attached to a device. The returned object works like a packet socket, it
+ * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
+ * holding a reference to the file for as long as the socket is in use. */
+struct socket *tun_get_socket(struct file *file)
+{
+ struct tun_file *tfile;
+ if (file->f_op != &tun_fops)
+ return ERR_PTR(-EINVAL);
+ tfile = file->private_data;
+ if (!tfile)
+ return ERR_PTR(-EBADFD);
+ return &tfile->socket;
+}
+EXPORT_SYMBOL_GPL(tun_get_socket);
+
+struct ptr_ring *tun_get_tx_ring(struct file *file)
+{
+ struct tun_file *tfile;
+
+ if (file->f_op != &tun_fops)
+ return ERR_PTR(-EINVAL);
+ tfile = file->private_data;
+ if (!tfile)
+ return ERR_PTR(-EBADFD);
+ return &tfile->tx_ring;
+}
+EXPORT_SYMBOL_GPL(tun_get_tx_ring);
+
+module_init(tun_init);
+module_exit(tun_cleanup);
+MODULE_DESCRIPTION(DRV_DESCRIPTION);
+MODULE_AUTHOR(DRV_COPYRIGHT);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(TUN_MINOR);
+MODULE_ALIAS("devname:net/tun");