| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * TUN - Universal TUN/TAP device driver. |
| * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com> |
| * |
| * $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 <net/ip_tunnels.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/ieee802154.h> |
| #include <linux/if_ltalk.h> |
| #include <uapi/linux/if_fddi.h> |
| #include <uapi/linux/if_hippi.h> |
| #include <uapi/linux/if_fc.h> |
| #include <net/ax25.h> |
| #include <net/rose.h> |
| #include <net/6lowpan.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); |
| |
| #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) |
| |
| /* 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 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_page { |
| struct page *page; |
| int count; |
| }; |
| |
| 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 ____cacheline_aligned_in_smp; |
| }; |
| |
| #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; |
| u32 msg_enable; |
| 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; |
| atomic_long_t rx_frame_errors; |
| struct bpf_prog __rcu *xdp_prog; |
| struct tun_prog __rcu *steering_prog; |
| struct tun_prog __rcu *filter_prog; |
| struct ethtool_link_ksettings link_ksettings; |
| /* init args */ |
| struct file *file; |
| struct ifreq *ifr; |
| }; |
| |
| struct veth { |
| __be16 h_vlan_proto; |
| __be16 h_vlan_TCI; |
| }; |
| |
| static void tun_flow_init(struct tun_struct *tun); |
| static void tun_flow_uninit(struct tun_struct *tun); |
| |
| 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_tx(tun->dev, &tfile->napi, tun_napi_poll); |
| napi_enable(&tfile->napi); |
| } |
| } |
| |
| static void tun_napi_enable(struct tun_file *tfile) |
| { |
| if (tfile->napi_enabled) |
| 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) { |
| netif_info(tun, tx_queued, tun->dev, |
| "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) |
| { |
| netif_info(tun, tx_queued, tun->dev, "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; |
| |
| 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; |
| |
| 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? */ |
| if (READ_ONCE(e->queue_index) != queue_index) |
| WRITE_ONCE(e->queue_index, queue_index); |
| if (e->updated != jiffies) |
| 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. 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. |
| */ |
| 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); |
| 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; |
| } |
| |
| return txq; |
| } |
| |
| static u16 tun_ebpf_select_queue(struct tun_struct *tun, struct sk_buff *skb) |
| { |
| struct tun_prog *prog; |
| u32 numqueues; |
| u16 ret = 0; |
| |
| numqueues = READ_ONCE(tun->numqueues); |
| if (!numqueues) |
| return 0; |
| |
| prog = rcu_dereference(tun->steering_prog); |
| if (prog) |
| ret = bpf_prog_run_clear_cb(prog->prog, skb); |
| |
| return ret % numqueues; |
| } |
| |
| static u16 tun_select_queue(struct net_device *dev, struct sk_buff *skb, |
| struct net_device *sb_dev) |
| { |
| 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) { |
| if (!tfile->detached) |
| 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; |
| rcu_assign_pointer(tun->tfiles[tun->numqueues - 1], |
| NULL); |
| |
| --tun->numqueues; |
| if (clean) { |
| RCU_INIT_POINTER(tfile->tun, NULL); |
| sock_put(&tfile->sk); |
| } else { |
| tun_disable_queue(tun, tfile); |
| tun_napi_disable(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); |
| } |
| } |
| |
| 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(); |
| |
| if (clean) |
| sock_put(&tfile->sk); |
| } |
| |
| 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_napi_del(tfile); |
| 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, |
| bool publish_tun) |
| { |
| 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, 0); |
| 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; |
| } |
| |
| if (tfile->detached) { |
| tun_enable_queue(tfile); |
| tun_napi_enable(tfile); |
| } else { |
| sock_hold(&tfile->sk); |
| tun_napi_init(tun, tfile, napi, napi_frags); |
| } |
| |
| if (rtnl_dereference(tun->xdp_prog)) |
| sock_set_flag(&tfile->sk, SOCK_XDP); |
| |
| /* device is allowed to go away first, so no need to hold extra |
| * refcnt. |
| */ |
| |
| /* Publish tfile->tun and tun->tfiles only after we've fully |
| * initialized tfile; otherwise we risk using half-initialized |
| * object. |
| */ |
| if (publish_tun) |
| rcu_assign_pointer(tfile->tun, tun); |
| rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile); |
| tun->numqueues++; |
| tun_set_real_num_queues(tun); |
| 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; |
| |
| static int tun_net_init(struct net_device *dev) |
| { |
| struct tun_struct *tun = netdev_priv(dev); |
| struct ifreq *ifr = tun->ifr; |
| int err; |
| |
| dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); |
| if (!dev->tstats) |
| return -ENOMEM; |
| |
| spin_lock_init(&tun->lock); |
| |
| err = security_tun_dev_alloc_security(&tun->security); |
| if (err < 0) { |
| free_percpu(dev->tstats); |
| return err; |
| } |
| |
| 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, tun->file, false, ifr->ifr_flags & IFF_NAPI, |
| ifr->ifr_flags & IFF_NAPI_FRAGS, false); |
| if (err < 0) { |
| tun_flow_uninit(tun); |
| security_tun_dev_free_security(tun->security); |
| free_percpu(dev->tstats); |
| return err; |
| } |
| return 0; |
| } |
| |
| /* 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) |
| { |
| netif_tx_start_all_queues(dev); |
| |
| 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_branch_unlikely(&rps_needed)) { |
| /* Select queue was not called for the skbuff, so we extract the |
| * RPS hash and save it into the flow_table here. |
| */ |
| struct tun_flow_entry *e; |
| __u32 rxhash; |
| |
| rxhash = __skb_get_hash_symmetric(skb); |
| 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); |
| enum skb_drop_reason drop_reason; |
| int txq = skb->queue_mapping; |
| struct netdev_queue *queue; |
| 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 (!tfile) { |
| drop_reason = SKB_DROP_REASON_DEV_READY; |
| goto drop; |
| } |
| |
| if (!rcu_dereference(tun->steering_prog)) |
| tun_automq_xmit(tun, skb); |
| |
| netif_info(tun, tx_queued, tun->dev, "%s %d\n", __func__, skb->len); |
| |
| /* 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)) { |
| drop_reason = SKB_DROP_REASON_TAP_TXFILTER; |
| goto drop; |
| } |
| |
| if (tfile->socket.sk->sk_filter && |
| sk_filter(tfile->socket.sk, skb)) { |
| drop_reason = SKB_DROP_REASON_SOCKET_FILTER; |
| goto drop; |
| } |
| |
| len = run_ebpf_filter(tun, skb, len); |
| if (len == 0) { |
| drop_reason = SKB_DROP_REASON_TAP_FILTER; |
| goto drop; |
| } |
| |
| if (pskb_trim(skb, len)) { |
| drop_reason = SKB_DROP_REASON_NOMEM; |
| goto drop; |
| } |
| |
| if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC))) { |
| drop_reason = SKB_DROP_REASON_SKB_UCOPY_FAULT; |
| 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_ct(skb); |
| |
| if (ptr_ring_produce(&tfile->tx_ring, skb)) { |
| drop_reason = SKB_DROP_REASON_FULL_RING; |
| goto drop; |
| } |
| |
| /* NETIF_F_LLTX requires to do our own update of trans_start */ |
| queue = netdev_get_tx_queue(dev, txq); |
| txq_trans_cond_update(queue); |
| |
| /* 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: |
| dev_core_stats_tx_dropped_inc(dev); |
| skb_tx_error(skb); |
| kfree_skb_reason(skb, drop_reason); |
| 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) |
| { |
| struct tun_struct *tun = netdev_priv(dev); |
| |
| dev_get_tstats64(dev, stats); |
| |
| stats->rx_frame_errors += |
| (unsigned long)atomic_long_read(&tun->rx_frame_errors); |
| } |
| |
| 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 tun_file *tfile; |
| struct bpf_prog *old_prog; |
| int i; |
| |
| old_prog = rtnl_dereference(tun->xdp_prog); |
| rcu_assign_pointer(tun->xdp_prog, prog); |
| if (old_prog) |
| bpf_prog_put(old_prog); |
| |
| for (i = 0; i < tun->numqueues; i++) { |
| tfile = rtnl_dereference(tun->tfiles[i]); |
| if (prog) |
| sock_set_flag(&tfile->sk, SOCK_XDP); |
| else |
| sock_reset_flag(&tfile->sk, SOCK_XDP); |
| } |
| list_for_each_entry(tfile, &tun->disabled, next) { |
| if (prog) |
| sock_set_flag(&tfile->sk, SOCK_XDP); |
| else |
| sock_reset_flag(&tfile->sk, SOCK_XDP); |
| } |
| |
| 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); |
| default: |
| return -EINVAL; |
| } |
| } |
| |
| static int tun_net_change_carrier(struct net_device *dev, bool new_carrier) |
| { |
| if (new_carrier) { |
| struct tun_struct *tun = netdev_priv(dev); |
| |
| if (!tun->numqueues) |
| return -EPERM; |
| |
| netif_carrier_on(dev); |
| } else { |
| netif_carrier_off(dev); |
| } |
| return 0; |
| } |
| |
| static const struct net_device_ops tun_netdev_ops = { |
| .ndo_init = tun_net_init, |
| .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, |
| .ndo_change_carrier = tun_net_change_carrier, |
| }; |
| |
| 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 nxmit = 0; |
| int i; |
| |
| if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) |
| return -EINVAL; |
| |
| rcu_read_lock(); |
| |
| resample: |
| 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]); |
| if (unlikely(!tfile)) |
| goto resample; |
| |
| 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)) { |
| dev_core_stats_tx_dropped_inc(dev); |
| break; |
| } |
| nxmit++; |
| } |
| spin_unlock(&tfile->tx_ring.producer_lock); |
| |
| if (flags & XDP_XMIT_FLUSH) |
| __tun_xdp_flush_tfile(tfile); |
| |
| rcu_read_unlock(); |
| return nxmit; |
| } |
| |
| static int tun_xdp_tx(struct net_device *dev, struct xdp_buff *xdp) |
| { |
| struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp); |
| int nxmit; |
| |
| if (unlikely(!frame)) |
| return -EOVERFLOW; |
| |
| nxmit = tun_xdp_xmit(dev, 1, &frame, XDP_XMIT_FLUSH); |
| if (!nxmit) |
| xdp_return_frame_rx_napi(frame); |
| return nxmit; |
| } |
| |
| static const struct net_device_ops tap_netdev_ops = { |
| .ndo_init = tun_net_init, |
| .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 = dev_get_tstats64, |
| .ndo_bpf = tun_xdp, |
| .ndo_xdp_xmit = tun_xdp_xmit, |
| .ndo_change_carrier = tun_net_change_carrier, |
| }; |
| |
| 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_initialize(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; |
| dev->header_ops = &ip_tunnel_header_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; |
| |
| 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 || |
| len > (ETH_MAX_MTU - NET_SKB_PAD - NET_IP_ALIGN)) |
| return ERR_PTR(-EMSGSIZE); |
| |
| 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; |
| struct page *page; |
| void *frag; |
| |
| if (fragsz == 0 || fragsz > PAGE_SIZE) { |
| err = -EINVAL; |
| goto free; |
| } |
| frag = netdev_alloc_frag(fragsz); |
| if (!frag) { |
| err = -ENOMEM; |
| goto free; |
| } |
| page = virt_to_head_page(frag); |
| skb_fill_page_desc(skb, i - 1, page, |
| frag - page_address(page), 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_file *tfile, |
| struct page_frag *alloc_frag, char *buf, |
| int buflen, int len, int pad) |
| { |
| struct sk_buff *skb = build_skb(buf, buflen); |
| |
| if (!skb) |
| return ERR_PTR(-ENOMEM); |
| |
| skb_reserve(skb, pad); |
| skb_put(skb, len); |
| skb_set_owner_w(skb, tfile->socket.sk); |
| |
| get_page(alloc_frag->page); |
| alloc_frag->offset += buflen; |
| |
| return skb; |
| } |
| |
| static int tun_xdp_act(struct tun_struct *tun, struct bpf_prog *xdp_prog, |
| struct xdp_buff *xdp, u32 act) |
| { |
| int err; |
| |
| switch (act) { |
| case XDP_REDIRECT: |
| err = xdp_do_redirect(tun->dev, xdp, xdp_prog); |
| if (err) |
| return err; |
| break; |
| case XDP_TX: |
| err = tun_xdp_tx(tun->dev, xdp); |
| if (err < 0) |
| return err; |
| break; |
| case XDP_PASS: |
| break; |
| default: |
| bpf_warn_invalid_xdp_action(tun->dev, xdp_prog, act); |
| fallthrough; |
| case XDP_ABORTED: |
| trace_xdp_exception(tun->dev, xdp_prog, act); |
| fallthrough; |
| case XDP_DROP: |
| dev_core_stats_rx_dropped_inc(tun->dev); |
| break; |
| } |
| |
| return act; |
| } |
| |
| 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 bpf_prog *xdp_prog; |
| int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); |
| char *buf; |
| size_t copied; |
| int pad = TUN_RX_PAD; |
| int err = 0; |
| |
| rcu_read_lock(); |
| xdp_prog = rcu_dereference(tun->xdp_prog); |
| if (xdp_prog) |
| pad += XDP_PACKET_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; |
| return __tun_build_skb(tfile, alloc_frag, buf, buflen, len, |
| pad); |
| } |
| |
| *skb_xdp = 0; |
| |
| local_bh_disable(); |
| rcu_read_lock(); |
| xdp_prog = rcu_dereference(tun->xdp_prog); |
| if (xdp_prog) { |
| struct xdp_buff xdp; |
| u32 act; |
| |
| xdp_init_buff(&xdp, buflen, &tfile->xdp_rxq); |
| xdp_prepare_buff(&xdp, buf, pad, len, false); |
| |
| act = bpf_prog_run_xdp(xdp_prog, &xdp); |
| if (act == XDP_REDIRECT || act == XDP_TX) { |
| get_page(alloc_frag->page); |
| alloc_frag->offset += buflen; |
| } |
| err = tun_xdp_act(tun, xdp_prog, &xdp, act); |
| if (err < 0) { |
| if (act == XDP_REDIRECT || act == XDP_TX) |
| put_page(alloc_frag->page); |
| goto out; |
| } |
| |
| if (err == XDP_REDIRECT) |
| xdp_do_flush(); |
| if (err != XDP_PASS) |
| goto out; |
| |
| pad = xdp.data - xdp.data_hard_start; |
| len = xdp.data_end - xdp.data; |
| } |
| rcu_read_unlock(); |
| local_bh_enable(); |
| |
| return __tun_build_skb(tfile, alloc_frag, buf, buflen, len, pad); |
| |
| out: |
| rcu_read_unlock(); |
| local_bh_enable(); |
| 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 }; |
| int good_linear; |
| int copylen; |
| bool zerocopy = false; |
| int err; |
| u32 rxhash = 0; |
| int skb_xdp = 1; |
| bool frags = tun_napi_frags_enabled(tfile); |
| enum skb_drop_reason drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; |
| |
| 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); |
| err = PTR_ERR_OR_ZERO(skb); |
| if (err) |
| goto drop; |
| 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); |
| } |
| |
| err = PTR_ERR_OR_ZERO(skb); |
| if (err) |
| goto drop; |
| |
| if (zerocopy) |
| err = zerocopy_sg_from_iter(skb, from); |
| else |
| err = skb_copy_datagram_from_iter(skb, 0, from, len); |
| |
| if (err) { |
| err = -EFAULT; |
| drop_reason = SKB_DROP_REASON_SKB_UCOPY_FAULT; |
| goto drop; |
| } |
| } |
| |
| if (virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun))) { |
| atomic_long_inc(&tun->rx_frame_errors); |
| err = -EINVAL; |
| goto free_skb; |
| } |
| |
| 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: |
| err = -EINVAL; |
| goto drop; |
| } |
| } |
| |
| skb_reset_mac_header(skb); |
| skb->protocol = pi.proto; |
| skb->dev = tun->dev; |
| break; |
| case IFF_TAP: |
| if (frags && !pskb_may_pull(skb, ETH_HLEN)) { |
| err = -ENOMEM; |
| drop_reason = SKB_DROP_REASON_HDR_TRUNC; |
| goto drop; |
| } |
| skb->protocol = eth_type_trans(skb, tun->dev); |
| break; |
| } |
| |
| /* copy skb_ubuf_info for callback when skb has no error */ |
| if (zerocopy) { |
| skb_zcopy_init(skb, msg_control); |
| } else if (msg_control) { |
| struct ubuf_info *uarg = msg_control; |
| uarg->callback(NULL, uarg, false); |
| } |
| |
| skb_reset_network_header(skb); |
| skb_probe_transport_header(skb); |
| skb_record_rx_queue(skb, tfile->queue_index); |
| |
| 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(); |
| goto unlock_frags; |
| } |
| } |
| 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); |
| |
| rcu_read_lock(); |
| if (unlikely(!(tun->dev->flags & IFF_UP))) { |
| err = -EIO; |
| rcu_read_unlock(); |
| drop_reason = SKB_DROP_REASON_DEV_READY; |
| goto drop; |
| } |
| |
| if (frags) { |
| u32 headlen; |
| |
| /* Exercise flow dissector code path. */ |
| skb_push(skb, ETH_HLEN); |
| headlen = eth_get_headlen(tun->dev, skb->data, |
| skb_headlen(skb)); |
| |
| if (unlikely(headlen > skb_headlen(skb))) { |
| WARN_ON_ONCE(1); |
| err = -ENOMEM; |
| dev_core_stats_rx_dropped_inc(tun->dev); |
| napi_busy: |
| napi_free_frags(&tfile->napi); |
| rcu_read_unlock(); |
| mutex_unlock(&tfile->napi_mutex); |
| return err; |
| } |
| |
| if (likely(napi_schedule_prep(&tfile->napi))) { |
| local_bh_disable(); |
| napi_gro_frags(&tfile->napi); |
| napi_complete(&tfile->napi); |
| local_bh_enable(); |
| } else { |
| err = -EBUSY; |
| goto napi_busy; |
| } |
| 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); |
| |
| if (unlikely(tfile->detached)) { |
| spin_unlock_bh(&queue->lock); |
| rcu_read_unlock(); |
| err = -EBUSY; |
| goto free_skb; |
| } |
| |
| __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(skb); |
| } |
| rcu_read_unlock(); |
| |
| preempt_disable(); |
| dev_sw_netstats_rx_add(tun->dev, len); |
| preempt_enable(); |
| |
| if (rxhash) |
| tun_flow_update(tun, rxhash, tfile); |
| |
| return total_len; |
| |
| drop: |
| if (err != -EAGAIN) |
| dev_core_stats_rx_dropped_inc(tun->dev); |
| |
| free_skb: |
| if (!IS_ERR_OR_NULL(skb)) |
| kfree_skb_reason(skb, drop_reason); |
| |
| unlock_frags: |
| if (frags) { |
| tfile->napi.skb = NULL; |
| mutex_unlock(&tfile->napi_mutex); |
| } |
| |
| return err ?: 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; |
| int noblock = 0; |
| |
| if (!tun) |
| return -EBADFD; |
| |
| if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT)) |
| noblock = 1; |
| |
| result = tun_get_user(tun, tfile, NULL, from, noblock, 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; |
| 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; |
| |
| preempt_disable(); |
| dev_sw_netstats_tx_add(tun->dev, 1, ret); |
| preempt_enable(); |
| |
| 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 }; |
| 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, */ |
| preempt_disable(); |
| dev_sw_netstats_tx_add(tun->dev, 1, skb->len + vlan_hlen); |
| preempt_enable(); |
| |
| 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->socket.wq.wait, &wait); |
| |
| while (1) { |
| set_current_state(TASK_INTERRUPTIBLE); |
| 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(); |
| } |
| |
| __set_current_state(TASK_RUNNING); |
| remove_wait_queue(&tfile->socket.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; |
| |
| 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; |
| int noblock = 0; |
| |
| if (!tun) |
| return -EBADFD; |
| |
| if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT)) |
| noblock = 1; |
| |
| ret = tun_do_read(tun, tfile, to, noblock, 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(dev->tstats); |
| 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 void tun_put_page(struct tun_page *tpage) |
| { |
| if (tpage->page) |
| __page_frag_cache_drain(tpage->page, tpage->count); |
| } |
| |
| static int tun_xdp_one(struct tun_struct *tun, |
| struct tun_file *tfile, |
| struct xdp_buff *xdp, int *flush, |
| struct tun_page *tpage) |
| { |
| unsigned int datasize = xdp->data_end - xdp->data; |
| struct tun_xdp_hdr *hdr = xdp->data_hard_start; |
| struct virtio_net_hdr *gso = &hdr->gso; |
| struct bpf_prog *xdp_prog; |
| struct sk_buff *skb = NULL; |
| struct sk_buff_head *queue; |
| u32 rxhash = 0, act; |
| int buflen = hdr->buflen; |
| int ret = 0; |
| bool skb_xdp = false; |
| struct page *page; |
| |
| xdp_prog = rcu_dereference(tun->xdp_prog); |
| if (xdp_prog) { |
| if (gso->gso_type) { |
| skb_xdp = true; |
| goto build; |
| } |
| |
| xdp_init_buff(xdp, buflen, &tfile->xdp_rxq); |
| xdp_set_data_meta_invalid(xdp); |
| |
| act = bpf_prog_run_xdp(xdp_prog, xdp); |
| ret = tun_xdp_act(tun, xdp_prog, xdp, act); |
| if (ret < 0) { |
| put_page(virt_to_head_page(xdp->data)); |
| return ret; |
| } |
| |
| switch (ret) { |
| case XDP_REDIRECT: |
| *flush = true; |
| fallthrough; |
| case XDP_TX: |
| return 0; |
| case XDP_PASS: |
| break; |
| default: |
| page = virt_to_head_page(xdp->data); |
| if (tpage->page == page) { |
| ++tpage->count; |
| } else { |
| tun_put_page(tpage); |
| tpage->page = page; |
| tpage->count = 1; |
| } |
| return 0; |
| } |
| } |
| |
| build: |
| skb = build_skb(xdp->data_hard_start, buflen); |
| if (!skb) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| skb_reserve(skb, xdp->data - xdp->data_hard_start); |
| skb_put(skb, xdp->data_end - xdp->data); |
| |
| if (virtio_net_hdr_to_skb(skb, gso, tun_is_little_endian(tun))) { |
| atomic_long_inc(&tun->rx_frame_errors); |
| kfree_skb(skb); |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| skb->protocol = eth_type_trans(skb, tun->dev); |
| skb_reset_network_header(skb); |
| skb_probe_transport_header(skb); |
| skb_record_rx_queue(skb, tfile->queue_index); |
| |
| if (skb_xdp) { |
| ret = do_xdp_generic(xdp_prog, skb); |
| if (ret != XDP_PASS) { |
| ret = 0; |
| goto out; |
| } |
| } |
| |
| if (!rcu_dereference(tun->steering_prog) && tun->numqueues > 1 && |
| !tfile->detached) |
| rxhash = __skb_get_hash_symmetric(skb); |
| |
| if (tfile->napi_enabled) { |
| queue = &tfile->sk.sk_write_queue; |
| spin_lock(&queue->lock); |
| |
| if (unlikely(tfile->detached)) { |
| spin_unlock(&queue->lock); |
| kfree_skb(skb); |
| return -EBUSY; |
| } |
| |
| __skb_queue_tail(queue, skb); |
| spin_unlock(&queue->lock); |
| ret = 1; |
| } else { |
| netif_receive_skb(skb); |
| ret = 0; |
| } |
| |
| /* No need to disable preemption here since this function is |
| * always called with bh disabled |
| */ |
| dev_sw_netstats_rx_add(tun->dev, datasize); |
| |
| if (rxhash) |
| tun_flow_update(tun, rxhash, tfile); |
| |
| out: |
| return ret; |
| } |
| |
| static int tun_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) |
| { |
| int ret, i; |
| struct tun_file *tfile = container_of(sock, struct tun_file, socket); |
| struct tun_struct *tun = tun_get(tfile); |
| struct tun_msg_ctl *ctl = m->msg_control; |
| struct xdp_buff *xdp; |
| |
| if (!tun) |
| return -EBADFD; |
| |
| if (m->msg_controllen == sizeof(struct tun_msg_ctl) && |
| ctl && ctl->type == TUN_MSG_PTR) { |
| struct tun_page tpage; |
| int n = ctl->num; |
| int flush = 0, queued = 0; |
| |
| memset(&tpage, 0, sizeof(tpage)); |
| |
| local_bh_disable(); |
| rcu_read_lock(); |
| |
| for (i = 0; i < n; i++) { |
| xdp = &((struct xdp_buff *)ctl->ptr)[i]; |
| ret = tun_xdp_one(tun, tfile, xdp, &flush, &tpage); |
| if (ret > 0) |
| queued += ret; |
| } |
| |
| if (flush) |
| xdp_do_flush(); |
| |
| if (tfile->napi_enabled && queued > 0) |
| napi_schedule(&tfile->napi); |
| |
| rcu_read_unlock(); |
| local_bh_enable(); |
| |
| tun_put_page(&tpage); |
| |
| ret = total_len; |
| goto out; |
| } |
| |
| ret = tun_get_user(tun, tfile, ctl ? ctl->ptr : NULL, &m->msg_iter, |
| m->msg_flags & MSG_DONTWAIT, |
| m->msg_flags & MSG_MORE); |
| out: |
| 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_flags_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct tun_struct *tun = netdev_priv(to_net_dev(dev)); |
| return sysfs_emit(buf, "0x%x\n", tun_flags(tun)); |
| } |
| |
| static ssize_t owner_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct tun_struct *tun = netdev_priv(to_net_dev(dev)); |
| return uid_valid(tun->owner)? |
| sysfs_emit(buf, "%u\n", |
| from_kuid_munged(current_user_ns(), tun->owner)) : |
| sysfs_emit(buf, "-1\n"); |
| } |
| |
| static ssize_t group_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct tun_struct *tun = netdev_priv(to_net_dev(dev)); |
| return gid_valid(tun->group) ? |
| sysfs_emit(buf, "%u\n", |
| from_kgid_munged(current_user_ns(), tun->group)) : |
| sysfs_emit(buf, "-1\n"); |
| } |
| |
| static DEVICE_ATTR_RO(tun_flags); |
| static DEVICE_ATTR_RO(owner); |
| static DEVICE_ATTR_RO(group); |
| |
| 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, true); |
| 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; |
| |
| 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->ifr = ifr; |
| tun->file = file; |
| |
| tun_net_initialize(dev); |
| |
| err = register_netdevice(tun->dev); |
| if (err < 0) { |
| free_netdev(dev); |
| return err; |
| } |
| /* free_netdev() won't check refcnt, to avoid race |
| * with dev_put() we need publish tun after registration. |
| */ |
| rcu_assign_pointer(tfile->tun, tun); |
| } |
| |
| if (ifr->ifr_flags & IFF_NO_CARRIER) |
| netif_carrier_off(tun->dev); |
| else |
| netif_carrier_on(tun->dev); |
| |
| /* 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; |
| } |
| |
| static void tun_get_iff(struct tun_struct *tun, struct ifreq *ifr) |
| { |
| 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, true); |
| } 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 __rcu **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); |
| } |
| |
| /* Return correct value for tun->dev->addr_len based on tun->dev->type. */ |
| static unsigned char tun_get_addr_len(unsigned short type) |
| { |
| switch (type) { |
| case ARPHRD_IP6GRE: |
| case ARPHRD_TUNNEL6: |
| return sizeof(struct in6_addr); |
| case ARPHRD_IPGRE: |
| case ARPHRD_TUNNEL: |
| case ARPHRD_SIT: |
| return 4; |
| case ARPHRD_ETHER: |
| return ETH_ALEN; |
| case ARPHRD_IEEE802154: |
| case ARPHRD_IEEE802154_MONITOR: |
| return IEEE802154_EXTENDED_ADDR_LEN; |
| case ARPHRD_PHONET_PIPE: |
| case ARPHRD_PPP: |
| case ARPHRD_NONE: |
| return 0; |
| case ARPHRD_6LOWPAN: |
| return EUI64_ADDR_LEN; |
| case ARPHRD_FDDI: |
| return FDDI_K_ALEN; |
| case ARPHRD_HIPPI: |
| return HIPPI_ALEN; |
| case ARPHRD_IEEE802: |
| return FC_ALEN; |
| case ARPHRD_ROSE: |
| return ROSE_ADDR_LEN; |
| case ARPHRD_NETROM: |
| return AX25_ADDR_LEN; |
| case ARPHRD_LOCALTLK: |
| return LTALK_ALEN; |
| default: |
| return 0; |
| } |
| } |
| |
| 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; |
| unsigned int ifindex, carrier; |
| struct ifreq ifr; |
| kuid_t owner; |
| kgid_t group; |
| int sndbuf; |
| int vnet_hdr_sz; |
| int le; |
| int ret; |
| bool do_notify = false; |
| |
| if (cmd == |