Something went wrong. Try again.
(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
Something went wrong. Try again.
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394959697989910010110210310410510610710810911011111211311411511611711811912012112212312412512612712812913013113213313413513613713813914014114214314414514614714814915015115215315415515615715815916016116216316416516616716816917017117217317417517617717817918018118218318418518618718818919019119219319419519619719819920020120220320420520620720820921021121221321421521621721821922022122222322422522622722822923023123223323423523623723823924024124224324424524624724824925025125225325425525625725825926026126226326426526626726826927027127227327427527627727827928028128228328428528628728828929029129229329429529629729829930030130230330430530630730830931031131231331431531631731831932032132232332432532632732832933033133233333433533633733833934034134234334434534634734834935035135235335435535635735835936036136236336436536636736836937037137237337437537637737837938038138238338438538638738838939039139239339439539639739839940040140240340440540640740840941041141241341441541641741841942042142242342442542642742842943043143243343443543643743843944044144244344444544644744844945045145245345445545645745845946046146246346446546646746846947047147247347447547647747847948048148248348448548648748848949049149249349449549649749849950050150250350450550650750850951051151251351451551651751851952052152252352452552652752852953053153253353453553653753853954054154254354454554654754854955055155255355455555655755855956056156256356456556656756856957057157257357457557657757857958058158258358458558658758858959059159259359459559659759859960060160260360460560660760860961061161261361461561661761861962062162262362462562662762862963063163263363463563663763863964064164264364464564664764864965065165265365465565665765865966066166266366466566666766866967067167267367467567667767867968068168268368468568668768868969069169269369469569669769869970070170270370470570670770870971071171271371471571671771871972072172272372472572672772872973073173273373473573673773873974074174274374474574674774874975075175275375475575675775875976076176276376476576676776876977077177277377477577677777877978078178278378478578678778878979079179279379479579679779879980080180280380480580680780880981081181281381481581681781881982082182282382482582682782882983083183283383483583683783883984084184284384484584684784884985085185285385485585685785885986086186286386486586686786886987087187287387487587687787887988088188288388488588688788888989089189289389489589689789889990090190290390490590690790890991091191291391491591691791891992092192292392492592692792892993093193293393493593693793893994094194294394494594694794894995095195295395495595695795895996096196296396496596696796896997097197297397497597697797897998098198298398498598698798898999099199299399499599699799899910001001100210031004100510061007100810091010101110121013101410151016101710181019102010211022102310241025102610271028102910301031103210331034103510361037103810391040104110421043104410451046104710481049105010511052105310541055105610571058105910601061106210631064106510661067106810691070107110721073107410751076107710781079108010811082108310841085108610871088108910901091109210931094109510961097109810991100110111021103110411051106110711081109111011111112111311141115111611171118111911201121112211231124112511261127112811291130113111321133113411351136113711381139114011411142114311441145114611471148114911501151115211531154115511561157115811591160116111621163116411651166116711681169117011711172117311741175117611771178117911801181118211831184118511861187118811891190119111921193119411951196119711981199120012011202120312041205120612071208120912101211121212131214121512161217121812191220122112221223122412251226122712281229123012311232123312341235123612371238123912401241124212431244124512461247124812491250125112521253125412551256125712581259126012611262126312641265126612671268126912701271127212731274127512761277127812791280128112821283128412851286128712881289129012911292129312941295129612971298// SPDX-License-Identifier: GPL-2.0-only#include <linux/etherdevice.h>#include <linux/if_tap.h>#include <linux/if_vlan.h>#include <linux/interrupt.h>#include <linux/nsproxy.h>#include <linux/compat.h>#include <linux/if_tun.h>#include <linux/module.h>#include <linux/skbuff.h>#include <linux/cache.h>#include <linux/sched/signal.h>#include <linux/types.h>#include <linux/slab.h>#include <linux/wait.h>#include <linux/cdev.h>#include <linux/idr.h>#include <linux/fs.h>#include <linux/uio.h>
#include <net/gso.h>#include <net/net_namespace.h>#include <net/rtnetlink.h>#include <net/sock.h>#include <net/xdp.h>#include <linux/virtio_net.h>#include <linux/skb_array.h>
#include "tun_vnet.h"
#define TAP_IFFEATURES (IFF_VNET_HDR | IFF_MULTI_QUEUE)
static struct proto tap_proto = { .name = "tap", .owner = THIS_MODULE, .obj_size = sizeof(struct tap_queue),};
#define TAP_NUM_DEVS (1U << MINORBITS)
static LIST_HEAD(major_list);
struct major_info { struct rcu_head rcu; dev_t major; struct idr minor_idr; spinlock_t minor_lock; const char *device_name; struct list_head next;};
#define GOODCOPY_LEN 128
static const struct proto_ops tap_socket_ops;
#define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)#define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG | NETIF_F_FRAGLIST)
static struct tap_dev *tap_dev_get_rcu(const struct net_device *dev){ return rcu_dereference(dev->rx_handler_data);}
/* * RCU usage: * The tap_queue and the macvlan_dev are loosely coupled, the * pointers from one to the other can only be read while rcu_read_lock * or rtnl is held. * * Both the file and the macvlan_dev hold a reference on the tap_queue * through sock_hold(&q->sk). When the macvlan_dev goes away first, * q->vlan becomes inaccessible. When the files gets closed, * tap_get_queue() fails. * * There may still be references to the struct sock inside of the * queue from outbound SKBs, but these never reference back to the * file or the dev. The data structure is freed through __sk_free * when both our references and any pending SKBs are gone. */
static int tap_enable_queue(struct tap_dev *tap, struct file *file, struct tap_queue *q){ int err = -EINVAL;
ASSERT_RTNL();
if (q->enabled) goto out;
err = 0; rcu_assign_pointer(tap->taps[tap->numvtaps], q); q->queue_index = tap->numvtaps; q->enabled = true;
tap->numvtaps++;out: return err;}
/* Requires RTNL */static int tap_set_queue(struct tap_dev *tap, struct file *file, struct tap_queue *q){ if (tap->numqueues == MAX_TAP_QUEUES) return -EBUSY;
rcu_assign_pointer(q->tap, tap); rcu_assign_pointer(tap->taps[tap->numvtaps], q); sock_hold(&q->sk);
q->file = file; q->queue_index = tap->numvtaps; q->enabled = true; file->private_data = q; list_add_tail(&q->next, &tap->queue_list);
tap->numvtaps++; tap->numqueues++;
return 0;}
static int tap_disable_queue(struct tap_queue *q){ struct tap_dev *tap; struct tap_queue *nq;
ASSERT_RTNL(); if (!q->enabled) return -EINVAL;
tap = rtnl_dereference(q->tap);
if (tap) { int index = q->queue_index; BUG_ON(index >= tap->numvtaps); nq = rtnl_dereference(tap->taps[tap->numvtaps - 1]); nq->queue_index = index;
rcu_assign_pointer(tap->taps[index], nq); RCU_INIT_POINTER(tap->taps[tap->numvtaps - 1], NULL); q->enabled = false;
tap->numvtaps--; }
return 0;}
/* * The file owning the queue got closed, give up both * the reference that the files holds as well as the * one from the macvlan_dev if that still exists. * * Using the spinlock makes sure that we don't get * to the queue again after destroying it. */static void tap_put_queue(struct tap_queue *q){ struct tap_dev *tap;
rtnl_lock(); tap = rtnl_dereference(q->tap);
if (tap) { if (q->enabled) BUG_ON(tap_disable_queue(q));
tap->numqueues--; RCU_INIT_POINTER(q->tap, NULL); sock_put(&q->sk); list_del_init(&q->next); }
rtnl_unlock();
synchronize_rcu(); sock_put(&q->sk);}
/* * Select a queue based on the rxq of the device on which this packet * arrived. If the incoming device is not mq, calculate a flow hash * to select a queue. If all fails, find the first available queue. * Cache vlan->numvtaps since it can become zero during the execution * of this function. */static struct tap_queue *tap_get_queue(struct tap_dev *tap, struct sk_buff *skb){ struct tap_queue *queue = NULL; /* Access to taps array is protected by rcu, but access to numvtaps * isn't. Below we use it to lookup a queue, but treat it as a hint * and validate that the result isn't NULL - in case we are * racing against queue removal. */ int numvtaps = READ_ONCE(tap->numvtaps); __u32 rxq;
if (!numvtaps) goto out;
if (numvtaps == 1) goto single;
/* Check if we can use flow to select a queue */ rxq = skb_get_hash(skb); if (rxq) { queue = rcu_dereference(tap->taps[rxq % numvtaps]); goto out; }
if (likely(skb_rx_queue_recorded(skb))) { rxq = skb_get_rx_queue(skb);
while (unlikely(rxq >= numvtaps)) rxq -= numvtaps;
queue = rcu_dereference(tap->taps[rxq]); goto out; }
single: queue = rcu_dereference(tap->taps[0]);out: return queue;}
/* * The net_device is going away, give up the reference * that it holds on all queues and safely set the pointer * from the queues to NULL. */void tap_del_queues(struct tap_dev *tap){ struct tap_queue *q, *tmp;
ASSERT_RTNL(); list_for_each_entry_safe(q, tmp, &tap->queue_list, next) { list_del_init(&q->next); RCU_INIT_POINTER(q->tap, NULL); if (q->enabled) tap->numvtaps--; tap->numqueues--; sock_put(&q->sk); } BUG_ON(tap->numvtaps); BUG_ON(tap->numqueues); /* guarantee that any future tap_set_queue will fail */ tap->numvtaps = MAX_TAP_QUEUES;}EXPORT_SYMBOL_GPL(tap_del_queues);
rx_handler_result_t tap_handle_frame(struct sk_buff **pskb){ struct sk_buff *skb = *pskb; struct net_device *dev = skb->dev; struct tap_dev *tap; struct tap_queue *q; netdev_features_t features = TAP_FEATURES; enum skb_drop_reason drop_reason;
tap = tap_dev_get_rcu(dev); if (!tap) return RX_HANDLER_PASS;
q = tap_get_queue(tap, skb); if (!q) return RX_HANDLER_PASS;
skb_push(skb, ETH_HLEN);
/* Apply the forward feature mask so that we perform segmentation * according to users wishes. This only works if VNET_HDR is * enabled. */ if (q->flags & IFF_VNET_HDR) features |= tap->tap_features; if (netif_needs_gso(skb, features)) { struct sk_buff *segs; struct sk_buff *next;
segs = __skb_gso_segment(skb, features, false, 0); if (IS_ERR(segs)) { drop_reason = SKB_DROP_REASON_SKB_GSO_SEG; goto drop; }
if (!segs) { if (ptr_ring_produce(&q->ring, skb)) { drop_reason = SKB_DROP_REASON_FULL_RING; goto drop; } goto wake_up; }
consume_skb(skb); skb_list_walk_safe(segs, skb, next) { skb_mark_not_on_list(skb); if (ptr_ring_produce(&q->ring, skb)) { drop_reason = SKB_DROP_REASON_FULL_RING; kfree_skb_reason(skb, drop_reason); kfree_skb_list_reason(next, drop_reason); break; } } } else { /* If we receive a partial checksum and the tap side * doesn't support checksum offload, compute the checksum. * Note: it doesn't matter which checksum feature to * check, we either support them all or none. */ if (skb->ip_summed == CHECKSUM_PARTIAL && !(features & NETIF_F_CSUM_MASK) && skb_checksum_help(skb)) { drop_reason = SKB_DROP_REASON_SKB_CSUM; goto drop; } if (ptr_ring_produce(&q->ring, skb)) { drop_reason = SKB_DROP_REASON_FULL_RING; goto drop; } }
wake_up: wake_up_interruptible_poll(sk_sleep(&q->sk), EPOLLIN | EPOLLRDNORM | EPOLLRDBAND); return RX_HANDLER_CONSUMED;
drop: /* Count errors/drops only here, thus don't care about args. */ if (tap->count_rx_dropped) tap->count_rx_dropped(tap); kfree_skb_reason(skb, drop_reason); return RX_HANDLER_CONSUMED;}EXPORT_SYMBOL_GPL(tap_handle_frame);
static struct major_info *tap_get_major(int major){ struct major_info *tap_major;
list_for_each_entry_rcu(tap_major, &major_list, next) { if (tap_major->major == major) return tap_major; }
return NULL;}
int tap_get_minor(dev_t major, struct tap_dev *tap){ int retval = -ENOMEM; struct major_info *tap_major;
rcu_read_lock(); tap_major = tap_get_major(MAJOR(major)); if (!tap_major) { retval = -EINVAL; goto unlock; }
spin_lock(&tap_major->minor_lock); retval = idr_alloc(&tap_major->minor_idr, tap, 1, TAP_NUM_DEVS, GFP_ATOMIC); if (retval >= 0) { tap->minor = retval; } else if (retval == -ENOSPC) { netdev_err(tap->dev, "Too many tap devices\n"); retval = -EINVAL; } spin_unlock(&tap_major->minor_lock);
unlock: rcu_read_unlock(); return retval < 0 ? retval : 0;}EXPORT_SYMBOL_GPL(tap_get_minor);
void tap_free_minor(dev_t major, struct tap_dev *tap){ struct major_info *tap_major;
rcu_read_lock(); tap_major = tap_get_major(MAJOR(major)); if (!tap_major) { goto unlock; }
spin_lock(&tap_major->minor_lock); if (tap->minor) { idr_remove(&tap_major->minor_idr, tap->minor); tap->minor = 0; } spin_unlock(&tap_major->minor_lock);
unlock: rcu_read_unlock();}EXPORT_SYMBOL_GPL(tap_free_minor);
static struct tap_dev *dev_get_by_tap_file(int major, int minor){ struct net_device *dev = NULL; struct tap_dev *tap; struct major_info *tap_major;
rcu_read_lock(); tap_major = tap_get_major(major); if (!tap_major) { tap = NULL; goto unlock; }
spin_lock(&tap_major->minor_lock); tap = idr_find(&tap_major->minor_idr, minor); if (tap) { dev = tap->dev; dev_hold(dev); } spin_unlock(&tap_major->minor_lock);
unlock: rcu_read_unlock(); return tap;}
static void tap_sock_write_space(struct sock *sk){ wait_queue_head_t *wqueue;
if (!sock_writeable(sk) || !test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &sk->sk_socket->flags)) return;
wqueue = sk_sleep(sk); if (wqueue && waitqueue_active(wqueue)) wake_up_interruptible_poll(wqueue, EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND);}
static void tap_sock_destruct(struct sock *sk){ struct tap_queue *q = container_of(sk, struct tap_queue, sk);
ptr_ring_cleanup(&q->ring, __skb_array_destroy_skb);}
static int tap_open(struct inode *inode, struct file *file){ struct net *net = current->nsproxy->net_ns; struct tap_dev *tap; struct tap_queue *q; int err = -ENODEV;
rtnl_lock(); tap = dev_get_by_tap_file(imajor(inode), iminor(inode)); if (!tap) goto err;
err = -ENOMEM; q = (struct tap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tap_proto, 0); if (!q) goto err; if (ptr_ring_init(&q->ring, tap->dev->tx_queue_len, GFP_KERNEL)) { sk_free(&q->sk); goto err; }
init_waitqueue_head(&q->sock.wq.wait); q->sock.type = SOCK_RAW; q->sock.state = SS_CONNECTED; q->sock.file = file; q->sock.ops = &tap_socket_ops; sock_init_data_uid(&q->sock, &q->sk, current_fsuid()); q->sk.sk_write_space = tap_sock_write_space; q->sk.sk_destruct = tap_sock_destruct; q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP; q->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
/* * so far only KVM virtio_net uses tap, enable zero copy between * guest kernel and host kernel when lower device supports zerocopy * * The macvlan supports zerocopy iff the lower device supports zero * copy so we don't have to look at the lower device directly. */ if ((tap->dev->features & NETIF_F_HIGHDMA) && (tap->dev->features & NETIF_F_SG)) sock_set_flag(&q->sk, SOCK_ZEROCOPY);
err = tap_set_queue(tap, file, q); if (err) { /* tap_sock_destruct() will take care of freeing ptr_ring */ goto err_put; }
/* tap groks IOCB_NOWAIT just fine, mark it as such */ file->f_mode |= FMODE_NOWAIT;
dev_put(tap->dev);
rtnl_unlock(); return err;
err_put: sock_put(&q->sk);err: if (tap) dev_put(tap->dev);
rtnl_unlock(); return err;}
static int tap_release(struct inode *inode, struct file *file){ struct tap_queue *q = file->private_data; tap_put_queue(q); return 0;}
static __poll_t tap_poll(struct file *file, poll_table *wait){ struct tap_queue *q = file->private_data; __poll_t mask = EPOLLERR;
if (!q) goto out;
mask = 0; poll_wait(file, &q->sock.wq.wait, wait);
if (!ptr_ring_empty(&q->ring)) mask |= EPOLLIN | EPOLLRDNORM;
if (sock_writeable(&q->sk) || (!test_and_set_bit(SOCKWQ_ASYNC_NOSPACE, &q->sock.flags) && sock_writeable(&q->sk))) mask |= EPOLLOUT | EPOLLWRNORM;
out: return mask;}
static inline struct sk_buff *tap_alloc_skb(struct sock *sk, size_t prepad, size_t len, size_t linear, int noblock, int *err){ struct sk_buff *skb;
/* Under a page? Don't bother with paged skb. */ if (prepad + len < PAGE_SIZE || !linear) linear = len;
if (len - linear > MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) linear = len - MAX_SKB_FRAGS * (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER); skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, err, PAGE_ALLOC_COSTLY_ORDER); if (!skb) return NULL;
skb_reserve(skb, prepad); skb_put(skb, linear); skb->data_len = len - linear; skb->len += len - linear;
return skb;}
/* Neighbour code has some assumptions on HH_DATA_MOD alignment */#define TAP_RESERVE HH_DATA_OFF(ETH_HLEN)
/* Get packet from user space buffer */static ssize_t tap_get_user(struct tap_queue *q, void *msg_control, struct iov_iter *from, int noblock){ int good_linear = SKB_MAX_HEAD(TAP_RESERVE); struct sk_buff *skb; struct tap_dev *tap; unsigned long total_len = iov_iter_count(from); unsigned long len = total_len; int err; struct virtio_net_hdr vnet_hdr = { 0 }; int vnet_hdr_len = 0; int hdr_len = 0; int copylen = 0; int depth; bool zerocopy = false; size_t linear; enum skb_drop_reason drop_reason;
if (q->flags & IFF_VNET_HDR) { vnet_hdr_len = READ_ONCE(q->vnet_hdr_sz);
hdr_len = tun_vnet_hdr_get(vnet_hdr_len, q->flags, from, &vnet_hdr); if (hdr_len < 0) { err = hdr_len; goto err; }
len -= vnet_hdr_len; }
err = -EINVAL; if (unlikely(len < ETH_HLEN)) goto err;
if (msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) { struct iov_iter i;
copylen = clamp(hdr_len ?: GOODCOPY_LEN, ETH_HLEN, good_linear); linear = copylen; i = *from; iov_iter_advance(&i, copylen); if (iov_iter_npages(&i, INT_MAX) <= MAX_SKB_FRAGS) zerocopy = true; }
if (!zerocopy) { copylen = len; linear = clamp(hdr_len, ETH_HLEN, good_linear); }
skb = tap_alloc_skb(&q->sk, TAP_RESERVE, copylen, linear, noblock, &err); if (!skb) goto err;
if (zerocopy) err = zerocopy_sg_from_iter(skb, from); else err = skb_copy_datagram_from_iter(skb, 0, from, len);
if (err) { drop_reason = SKB_DROP_REASON_SKB_UCOPY_FAULT; goto err_kfree; }
skb_set_network_header(skb, ETH_HLEN); skb_reset_mac_header(skb); skb->protocol = eth_hdr(skb)->h_proto;
rcu_read_lock(); tap = rcu_dereference(q->tap); if (!tap) { kfree_skb(skb); rcu_read_unlock(); return total_len; } skb->dev = tap->dev;
if (vnet_hdr_len) { err = tun_vnet_hdr_to_skb(q->flags, skb, &vnet_hdr); if (err) { rcu_read_unlock(); drop_reason = SKB_DROP_REASON_DEV_HDR; goto err_kfree; } }
skb_probe_transport_header(skb);
/* Move network header to the right position for VLAN tagged packets */ if (eth_type_vlan(skb->protocol) && vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0) skb_set_network_header(skb, depth);
/* 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->ops->complete(NULL, uarg, false); }
dev_queue_xmit(skb); rcu_read_unlock(); return total_len;
err_kfree: kfree_skb_reason(skb, drop_reason);
err: rcu_read_lock(); tap = rcu_dereference(q->tap); if (tap && tap->count_tx_dropped) tap->count_tx_dropped(tap); rcu_read_unlock();
return err;}
static ssize_t tap_write_iter(struct kiocb *iocb, struct iov_iter *from){ struct file *file = iocb->ki_filp; struct tap_queue *q = file->private_data; int noblock = 0;
if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT)) noblock = 1;
return tap_get_user(q, NULL, from, noblock);}
/* Put packet to the user space buffer */static ssize_t tap_put_user(struct tap_queue *q, const struct sk_buff *skb, struct iov_iter *iter){ int ret; int vnet_hdr_len = 0; int vlan_offset = 0; int total;
if (q->flags & IFF_VNET_HDR) { struct virtio_net_hdr vnet_hdr;
vnet_hdr_len = READ_ONCE(q->vnet_hdr_sz);
ret = tun_vnet_hdr_from_skb(q->flags, NULL, skb, &vnet_hdr); if (ret) return ret;
ret = tun_vnet_hdr_put(vnet_hdr_len, iter, &vnet_hdr); if (ret) return ret; } total = vnet_hdr_len; total += skb->len;
if (skb_vlan_tag_present(skb)) { struct { __be16 h_vlan_proto; __be16 h_vlan_TCI; } 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); total += VLAN_HLEN;
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; }
ret = skb_copy_datagram_iter(skb, vlan_offset, iter, skb->len - vlan_offset);
done: return ret ? ret : total;}
static ssize_t tap_do_read(struct tap_queue *q, struct iov_iter *to, int noblock, struct sk_buff *skb){ DEFINE_WAIT(wait); ssize_t ret = 0;
if (!iov_iter_count(to)) { kfree_skb(skb); return 0; }
if (skb) goto put;
while (1) { if (!noblock) prepare_to_wait(sk_sleep(&q->sk), &wait, TASK_INTERRUPTIBLE);
/* Read frames from the queue */ skb = ptr_ring_consume(&q->ring); if (skb) break; if (noblock) { ret = -EAGAIN; break; } if (signal_pending(current)) { ret = -ERESTARTSYS; break; } /* Nothing to read, let's sleep */ schedule(); } if (!noblock) finish_wait(sk_sleep(&q->sk), &wait);
put: if (skb) { ret = tap_put_user(q, skb, to); if (unlikely(ret < 0)) kfree_skb(skb); else consume_skb(skb); } return ret;}
static ssize_t tap_read_iter(struct kiocb *iocb, struct iov_iter *to){ struct file *file = iocb->ki_filp; struct tap_queue *q = file->private_data; ssize_t len = iov_iter_count(to), ret; int noblock = 0;
if ((file->f_flags & O_NONBLOCK) || (iocb->ki_flags & IOCB_NOWAIT)) noblock = 1;
ret = tap_do_read(q, to, noblock, NULL); ret = min_t(ssize_t, ret, len); if (ret > 0) iocb->ki_pos = ret; return ret;}
static struct tap_dev *tap_get_tap_dev(struct tap_queue *q){ struct tap_dev *tap;
ASSERT_RTNL(); tap = rtnl_dereference(q->tap); if (tap) dev_hold(tap->dev);
return tap;}
static void tap_put_tap_dev(struct tap_dev *tap){ dev_put(tap->dev);}
static int tap_ioctl_set_queue(struct file *file, unsigned int flags){ struct tap_queue *q = file->private_data; struct tap_dev *tap; int ret;
tap = tap_get_tap_dev(q); if (!tap) return -EINVAL;
if (flags & IFF_ATTACH_QUEUE) ret = tap_enable_queue(tap, file, q); else if (flags & IFF_DETACH_QUEUE) ret = tap_disable_queue(q); else ret = -EINVAL;
tap_put_tap_dev(tap); return ret;}
static int set_offload(struct tap_queue *q, unsigned long arg){ struct tap_dev *tap; netdev_features_t features; netdev_features_t feature_mask = 0;
tap = rtnl_dereference(q->tap); if (!tap) return -ENOLINK;
features = tap->dev->features;
if (arg & TUN_F_CSUM) { feature_mask = NETIF_F_HW_CSUM;
if (arg & (TUN_F_TSO4 | TUN_F_TSO6)) { if (arg & TUN_F_TSO_ECN) feature_mask |= NETIF_F_TSO_ECN; if (arg & TUN_F_TSO4) feature_mask |= NETIF_F_TSO; if (arg & TUN_F_TSO6) feature_mask |= NETIF_F_TSO6; }
/* TODO: for now USO4 and USO6 should work simultaneously */ if ((arg & (TUN_F_USO4 | TUN_F_USO6)) == (TUN_F_USO4 | TUN_F_USO6)) feature_mask |= NETIF_F_GSO_UDP_L4; }
/* tun/tap driver inverts the usage for TSO offloads, where * setting the TSO bit means that the userspace wants to * accept TSO frames and turning it off means that user space * does not support TSO. * For tap, we have to invert it to mean the same thing. * When user space turns off TSO, we turn off GSO/LRO so that * user-space will not receive TSO frames. */ if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_GSO_UDP_L4)) features |= RX_OFFLOADS; else features &= ~RX_OFFLOADS;
/* tap_features are the same as features on tun/tap and * reflect user expectations. */ tap->tap_features = feature_mask; if (tap->update_features) tap->update_features(tap, features);
return 0;}
/* * provide compatibility with generic tun/tap interface */static long tap_ioctl(struct file *file, unsigned int cmd, unsigned long arg){ struct tap_queue *q = file->private_data; struct tap_dev *tap; void __user *argp = (void __user *)arg; struct sockaddr_storage ss = {}; struct ifreq __user *ifr = argp; unsigned int __user *up = argp; unsigned short u; int __user *sp = argp; int s; int ret;
switch (cmd) { case TUNSETIFF: /* ignore the name, just look at flags */ if (get_user(u, &ifr->ifr_flags)) return -EFAULT;
/* TUNGETIFF may report IFF_DETACH_QUEUE, ignore it here */ u &= ~IFF_DETACH_QUEUE;
ret = 0; if ((u & ~TAP_IFFEATURES) != (IFF_NO_PI | IFF_TAP)) ret = -EINVAL; else q->flags = (q->flags & ~TAP_IFFEATURES) | u;
return ret;
case TUNGETIFF: rtnl_lock(); tap = tap_get_tap_dev(q); if (!tap) { rtnl_unlock(); return -ENOLINK; }
ret = 0; u = q->flags; if (!q->enabled) u |= IFF_DETACH_QUEUE; if (copy_to_user(&ifr->ifr_name, tap->dev->name, IFNAMSIZ) || put_user(u, &ifr->ifr_flags)) ret = -EFAULT; tap_put_tap_dev(tap); rtnl_unlock(); return ret;
case TUNSETQUEUE: if (get_user(u, &ifr->ifr_flags)) return -EFAULT; rtnl_lock(); ret = tap_ioctl_set_queue(file, u); rtnl_unlock(); return ret;
case TUNGETFEATURES: if (put_user(IFF_TAP | IFF_NO_PI | TAP_IFFEATURES, up)) return -EFAULT; return 0;
case TUNSETSNDBUF: if (get_user(s, sp)) return -EFAULT; if (s <= 0) return -EINVAL;
q->sk.sk_sndbuf = s; return 0;
case TUNSETOFFLOAD: /* let the user check for future flags */ if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 | TUN_F_TSO_ECN | TUN_F_UFO | TUN_F_USO4 | TUN_F_USO6)) return -EINVAL;
rtnl_lock(); ret = set_offload(q, arg); rtnl_unlock(); return ret;
case SIOCGIFHWADDR: rtnl_lock(); tap = tap_get_tap_dev(q); if (!tap) { rtnl_unlock(); return -ENOLINK; } ret = 0; netif_get_mac_address((struct sockaddr *)&ss, dev_net(tap->dev), tap->dev->name); if (copy_to_user(&ifr->ifr_name, tap->dev->name, IFNAMSIZ) || copy_to_user(&ifr->ifr_hwaddr, &ss, sizeof(ifr->ifr_hwaddr))) ret = -EFAULT; tap_put_tap_dev(tap); rtnl_unlock(); return ret;
case SIOCSIFHWADDR: if (copy_from_user(&ss, &ifr->ifr_hwaddr, sizeof(ifr->ifr_hwaddr))) return -EFAULT; rtnl_lock(); tap = tap_get_tap_dev(q); if (!tap) { rtnl_unlock(); return -ENOLINK; } if (tap->dev->addr_len > sizeof(ifr->ifr_hwaddr)) ret = -EINVAL; else ret = dev_set_mac_address_user(tap->dev, &ss, NULL); tap_put_tap_dev(tap); rtnl_unlock(); return ret;
default: return tun_vnet_ioctl(&q->vnet_hdr_sz, &q->flags, cmd, sp); }}
static const struct file_operations tap_fops = { .owner = THIS_MODULE, .open = tap_open, .release = tap_release, .read_iter = tap_read_iter, .write_iter = tap_write_iter, .poll = tap_poll, .unlocked_ioctl = tap_ioctl, .compat_ioctl = compat_ptr_ioctl,};
static int tap_get_user_xdp(struct tap_queue *q, struct xdp_buff *xdp){ struct virtio_net_hdr *gso = xdp->data_hard_start; int buflen = xdp->frame_sz; int vnet_hdr_len = 0; struct tap_dev *tap; struct sk_buff *skb; int err, depth;
if (unlikely(xdp->data_end - xdp->data < ETH_HLEN)) { put_page(virt_to_head_page(xdp->data)); err = -EINVAL; goto err; }
if (q->flags & IFF_VNET_HDR) vnet_hdr_len = READ_ONCE(q->vnet_hdr_sz);
skb = build_skb(xdp->data_hard_start, buflen); if (!skb) { put_page(virt_to_head_page(xdp->data)); err = -ENOMEM; goto err; }
skb_reserve(skb, xdp->data - xdp->data_hard_start); skb_put(skb, xdp->data_end - xdp->data);
skb_set_network_header(skb, ETH_HLEN); skb_reset_mac_header(skb); skb->protocol = eth_hdr(skb)->h_proto;
rcu_read_lock(); tap = rcu_dereference(q->tap); if (!tap) { kfree_skb(skb); rcu_read_unlock(); return 0; } skb->dev = tap->dev;
if (vnet_hdr_len) { err = tun_vnet_hdr_to_skb(q->flags, skb, gso); if (err) { rcu_read_unlock(); goto err_kfree; } }
skb_probe_transport_header(skb);
/* Move network header to the right position for VLAN tagged packets */ if (eth_type_vlan(skb->protocol) && vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0) skb_set_network_header(skb, depth);
dev_queue_xmit(skb); rcu_read_unlock();
return 0;
err_kfree: kfree_skb(skb);err: rcu_read_lock(); tap = rcu_dereference(q->tap); if (tap && tap->count_tx_dropped) tap->count_tx_dropped(tap); rcu_read_unlock(); return err;}
static int tap_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len){ struct tap_queue *q = container_of(sock, struct tap_queue, sock); struct tun_msg_ctl *ctl = m->msg_control; struct xdp_buff *xdp; int i;
if (m->msg_controllen == sizeof(struct tun_msg_ctl) && ctl && ctl->type == TUN_MSG_PTR) { for (i = 0; i < ctl->num; i++) { xdp = &((struct xdp_buff *)ctl->ptr)[i]; tap_get_user_xdp(q, xdp); } return 0; }
return tap_get_user(q, ctl ? ctl->ptr : NULL, &m->msg_iter, m->msg_flags & MSG_DONTWAIT);}
static int tap_recvmsg(struct socket *sock, struct msghdr *m, size_t total_len, int flags){ struct tap_queue *q = container_of(sock, struct tap_queue, sock); struct sk_buff *skb = m->msg_control; int ret; if (flags & ~(MSG_DONTWAIT|MSG_TRUNC)) { kfree_skb(skb); return -EINVAL; } ret = tap_do_read(q, &m->msg_iter, flags & MSG_DONTWAIT, skb); if (ret > total_len) { m->msg_flags |= MSG_TRUNC; ret = flags & MSG_TRUNC ? ret : total_len; } return ret;}
static int tap_peek_len(struct socket *sock){ struct tap_queue *q = container_of(sock, struct tap_queue, sock); return PTR_RING_PEEK_CALL(&q->ring, __skb_array_len_with_tag);}
/* Ops structure to mimic raw sockets with tun */static const struct proto_ops tap_socket_ops = { .sendmsg = tap_sendmsg, .recvmsg = tap_recvmsg, .peek_len = tap_peek_len,};
/* 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 *tap_get_socket(struct file *file){ struct tap_queue *q; if (file->f_op != &tap_fops) return ERR_PTR(-EINVAL); q = file->private_data; if (!q) return ERR_PTR(-EBADFD); return &q->sock;}EXPORT_SYMBOL_GPL(tap_get_socket);
struct ptr_ring *tap_get_ptr_ring(struct file *file){ struct tap_queue *q;
if (file->f_op != &tap_fops) return ERR_PTR(-EINVAL); q = file->private_data; if (!q) return ERR_PTR(-EBADFD); return &q->ring;}EXPORT_SYMBOL_GPL(tap_get_ptr_ring);
int tap_queue_resize(struct tap_dev *tap){ struct net_device *dev = tap->dev; struct tap_queue *q; struct ptr_ring **rings; int n = tap->numqueues; int ret, i = 0;
rings = kmalloc_objs(*rings, n); if (!rings) return -ENOMEM;
list_for_each_entry(q, &tap->queue_list, next) rings[i++] = &q->ring;
ret = ptr_ring_resize_multiple_bh(rings, n, dev->tx_queue_len, GFP_KERNEL, __skb_array_destroy_skb);
kfree(rings); return ret;}EXPORT_SYMBOL_GPL(tap_queue_resize);
static int tap_list_add(dev_t major, const char *device_name){ struct major_info *tap_major;
tap_major = kzalloc_obj(*tap_major, GFP_ATOMIC); if (!tap_major) return -ENOMEM;
tap_major->major = MAJOR(major);
idr_init(&tap_major->minor_idr); spin_lock_init(&tap_major->minor_lock);
tap_major->device_name = device_name;
list_add_tail_rcu(&tap_major->next, &major_list); return 0;}
int tap_create_cdev(struct cdev *tap_cdev, dev_t *tap_major, const char *device_name, struct module *module){ int err;
err = alloc_chrdev_region(tap_major, 0, TAP_NUM_DEVS, device_name); if (err) goto out1;
cdev_init(tap_cdev, &tap_fops); tap_cdev->owner = module; err = cdev_add(tap_cdev, *tap_major, TAP_NUM_DEVS); if (err) goto out2;
err = tap_list_add(*tap_major, device_name); if (err) goto out3;
return 0;
out3: cdev_del(tap_cdev);out2: unregister_chrdev_region(*tap_major, TAP_NUM_DEVS);out1: return err;}EXPORT_SYMBOL_GPL(tap_create_cdev);
void tap_destroy_cdev(dev_t major, struct cdev *tap_cdev){ struct major_info *tap_major, *tmp;
cdev_del(tap_cdev); unregister_chrdev_region(major, TAP_NUM_DEVS); list_for_each_entry_safe(tap_major, tmp, &major_list, next) { if (tap_major->major == MAJOR(major)) { idr_destroy(&tap_major->minor_idr); list_del_rcu(&tap_major->next); kfree_rcu(tap_major, rcu); } }}EXPORT_SYMBOL_GPL(tap_destroy_cdev);
MODULE_DESCRIPTION("Common library for drivers implementing the TAP interface");MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");MODULE_AUTHOR("Sainath Grandhi <sainath.grandhi@intel.com>");MODULE_LICENSE("GPL");MODULE_IMPORT_NS("NETDEV_INTERNAL");