drivers/net/veth.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  drivers/net/veth.c
   4  *
   5  *  Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
   6  *
   7  * Author: Pavel Emelianov <xemul@openvz.org>
   8  * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
   9  *
  10  */
  11
  12 #include <linux/netdevice.h>
  13 #include <linux/slab.h>
  14 #include <linux/ethtool.h>
  15 #include <linux/etherdevice.h>
  16 #include <linux/u64_stats_sync.h>
  17
  18 #include <net/rtnetlink.h>
  19 #include <net/dst.h>
  20 #include <net/xfrm.h>
  21 #include <net/xdp.h>
  22 #include <linux/veth.h>
  23 #include <linux/module.h>
  24 #include <linux/bpf.h>
  25 #include <linux/filter.h>
  26 #include <linux/ptr_ring.h>
  27 #include <linux/bpf_trace.h>
  28 #include <linux/net_tstamp.h>
  29
  30 #define DRV_NAME        "veth"
  31 #define DRV_VERSION     "1.0"
  32
  33 #define VETH_XDP_FLAG           BIT(0)
  34 #define VETH_RING_SIZE          256
  35 #define VETH_XDP_HEADROOM       (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
  36
  37 #define VETH_XDP_TX_BULK_SIZE   16
  38 #define VETH_XDP_BATCH          16
  39
  40 struct veth_stats {
  41         u64     rx_drops;
  42         /* xdp */
  43         u64     xdp_packets;
  44         u64     xdp_bytes;
  45         u64     xdp_redirect;
  46         u64     xdp_drops;
  47         u64     xdp_tx;
  48         u64     xdp_tx_err;
  49         u64     peer_tq_xdp_xmit;
  50         u64     peer_tq_xdp_xmit_err;
  51 };
  52
  53 struct veth_rq_stats {
  54         struct veth_stats       vs;
  55         struct u64_stats_sync   syncp;
  56 };
  57
  58 struct veth_rq {
  59         struct napi_struct      xdp_napi;
  60         struct net_device       *dev;
  61         struct bpf_prog __rcu   *xdp_prog;
  62         struct xdp_mem_info     xdp_mem;
  63         struct veth_rq_stats    stats;
  64         bool                    rx_notify_masked;
  65         struct ptr_ring         xdp_ring;
  66         struct xdp_rxq_info     xdp_rxq;
  67 };
  68
  69 struct veth_priv {
  70         struct net_device __rcu *peer;
  71         atomic64_t              dropped;
  72         struct bpf_prog         *_xdp_prog;
  73         struct veth_rq          *rq;
  74         unsigned int            requested_headroom;
  75 };
  76
  77 struct veth_xdp_tx_bq {
  78         struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
  79         unsigned int count;
  80 };
  81
  82 /*
  83  * ethtool interface
  84  */
  85
  86 struct veth_q_stat_desc {
  87         char    desc[ETH_GSTRING_LEN];
  88         size_t  offset;
  89 };
  90
  91 #define VETH_RQ_STAT(m) offsetof(struct veth_stats, m)
  92
  93 static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
  94         { "xdp_packets",        VETH_RQ_STAT(xdp_packets) },
  95         { "xdp_bytes",          VETH_RQ_STAT(xdp_bytes) },
  96         { "drops",              VETH_RQ_STAT(rx_drops) },
  97         { "xdp_redirect",       VETH_RQ_STAT(xdp_redirect) },
  98         { "xdp_drops",          VETH_RQ_STAT(xdp_drops) },
  99         { "xdp_tx",             VETH_RQ_STAT(xdp_tx) },
 100         { "xdp_tx_errors",      VETH_RQ_STAT(xdp_tx_err) },
 101 };
 102
 103 #define VETH_RQ_STATS_LEN       ARRAY_SIZE(veth_rq_stats_desc)
 104
 105 static const struct veth_q_stat_desc veth_tq_stats_desc[] = {
 106         { "xdp_xmit",           VETH_RQ_STAT(peer_tq_xdp_xmit) },
 107         { "xdp_xmit_errors",    VETH_RQ_STAT(peer_tq_xdp_xmit_err) },
 108 };
 109
 110 #define VETH_TQ_STATS_LEN       ARRAY_SIZE(veth_tq_stats_desc)
 111
 112 static struct {
 113         const char string[ETH_GSTRING_LEN];
 114 } ethtool_stats_keys[] = {
 115         { "peer_ifindex" },
 116 };
 117
 118 static int veth_get_link_ksettings(struct net_device *dev,
 119                                    struct ethtool_link_ksettings *cmd)
 120 {
 121         cmd->base.speed         = SPEED_10000;
 122         cmd->base.duplex        = DUPLEX_FULL;
 123         cmd->base.port          = PORT_TP;
 124         cmd->base.autoneg       = AUTONEG_DISABLE;
 125         return 0;
 126 }
 127
 128 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 129 {
 130         strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
 131         strlcpy(info->version, DRV_VERSION, sizeof(info->version));
 132 }
 133
 134 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
 135 {
 136         char *p = (char *)buf;
 137         int i, j;
 138
 139         switch(stringset) {
 140         case ETH_SS_STATS:
 141                 memcpy(p, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
 142                 p += sizeof(ethtool_stats_keys);
 143                 for (i = 0; i < dev->real_num_rx_queues; i++) {
 144                         for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
 145                                 snprintf(p, ETH_GSTRING_LEN,
 146                                          "rx_queue_%u_%.18s",
 147                                          i, veth_rq_stats_desc[j].desc);
 148                                 p += ETH_GSTRING_LEN;
 149                         }
 150                 }
 151                 for (i = 0; i < dev->real_num_tx_queues; i++) {
 152                         for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
 153                                 snprintf(p, ETH_GSTRING_LEN,
 154                                          "tx_queue_%u_%.18s",
 155                                          i, veth_tq_stats_desc[j].desc);
 156                                 p += ETH_GSTRING_LEN;
 157                         }
 158                 }
 159                 break;
 160         }
 161 }
 162
 163 static int veth_get_sset_count(struct net_device *dev, int sset)
 164 {
 165         switch (sset) {
 166         case ETH_SS_STATS:
 167                 return ARRAY_SIZE(ethtool_stats_keys) +
 168                        VETH_RQ_STATS_LEN * dev->real_num_rx_queues +
 169                        VETH_TQ_STATS_LEN * dev->real_num_tx_queues;
 170         default:
 171                 return -EOPNOTSUPP;
 172         }
 173 }
 174
 175 static void veth_get_ethtool_stats(struct net_device *dev,
 176                 struct ethtool_stats *stats, u64 *data)
 177 {
 178         struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 179         struct net_device *peer = rtnl_dereference(priv->peer);
 180         int i, j, idx;
 181
 182         data[0] = peer ? peer->ifindex : 0;
 183         idx = 1;
 184         for (i = 0; i < dev->real_num_rx_queues; i++) {
 185                 const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
 186                 const void *stats_base = (void *)&rq_stats->vs;
 187                 unsigned int start;
 188                 size_t offset;
 189
 190                 do {
 191                         start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
 192                         for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
 193                                 offset = veth_rq_stats_desc[j].offset;
 194                                 data[idx + j] = *(u64 *)(stats_base + offset);
 195                         }
 196                 } while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
 197                 idx += VETH_RQ_STATS_LEN;
 198         }
 199
 200         if (!peer)
 201                 return;
 202
 203         rcv_priv = netdev_priv(peer);
 204         for (i = 0; i < peer->real_num_rx_queues; i++) {
 205                 const struct veth_rq_stats *rq_stats = &rcv_priv->rq[i].stats;
 206                 const void *base = (void *)&rq_stats->vs;
 207                 unsigned int start, tx_idx = idx;
 208                 size_t offset;
 209
 210                 tx_idx += (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN;
 211                 do {
 212                         start = u64_stats_fetch_begin_irq(&rq_stats->syncp);
 213                         for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
 214                                 offset = veth_tq_stats_desc[j].offset;
 215                                 data[tx_idx + j] += *(u64 *)(base + offset);
 216                         }
 217                 } while (u64_stats_fetch_retry_irq(&rq_stats->syncp, start));
 218         }
 219 }
 220
 221 static const struct ethtool_ops veth_ethtool_ops = {
 222         .get_drvinfo            = veth_get_drvinfo,
 223         .get_link               = ethtool_op_get_link,
 224         .get_strings            = veth_get_strings,
 225         .get_sset_count         = veth_get_sset_count,
 226         .get_ethtool_stats      = veth_get_ethtool_stats,
 227         .get_link_ksettings     = veth_get_link_ksettings,
 228         .get_ts_info            = ethtool_op_get_ts_info,
 229 };
 230
 231 /* general routines */
 232
 233 static bool veth_is_xdp_frame(void *ptr)
 234 {
 235         return (unsigned long)ptr & VETH_XDP_FLAG;
 236 }
 237
 238 static struct xdp_frame *veth_ptr_to_xdp(void *ptr)
 239 {
 240         return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
 241 }
 242
 243 static void *veth_xdp_to_ptr(struct xdp_frame *xdp)
 244 {
 245         return (void *)((unsigned long)xdp | VETH_XDP_FLAG);
 246 }
 247
 248 static void veth_ptr_free(void *ptr)
 249 {
 250         if (veth_is_xdp_frame(ptr))
 251                 xdp_return_frame(veth_ptr_to_xdp(ptr));
 252         else
 253                 kfree_skb(ptr);
 254 }
 255
 256 static void __veth_xdp_flush(struct veth_rq *rq)
 257 {
 258         /* Write ptr_ring before reading rx_notify_masked */
 259         smp_mb();
 260         if (!rq->rx_notify_masked) {
 261                 rq->rx_notify_masked = true;
 262                 napi_schedule(&rq->xdp_napi);
 263         }
 264 }
 265
 266 static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
 267 {
 268         if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
 269                 dev_kfree_skb_any(skb);
 270                 return NET_RX_DROP;
 271         }
 272
 273         return NET_RX_SUCCESS;
 274 }
 275
 276 static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
 277                             struct veth_rq *rq, bool xdp)
 278 {
 279         return __dev_forward_skb(dev, skb) ?: xdp ?
 280                 veth_xdp_rx(rq, skb) :
 281                 netif_rx(skb);
 282 }
 283
 284 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 285 {
 286         struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 287         struct veth_rq *rq = NULL;
 288         struct net_device *rcv;
 289         int length = skb->len;
 290         bool rcv_xdp = false;
 291         int rxq;
 292
 293         rcu_read_lock();
 294         rcv = rcu_dereference(priv->peer);
 295         if (unlikely(!rcv)) {
 296                 kfree_skb(skb);
 297                 goto drop;
 298         }
 299
 300         rcv_priv = netdev_priv(rcv);
 301         rxq = skb_get_queue_mapping(skb);
 302         if (rxq < rcv->real_num_rx_queues) {
 303                 rq = &rcv_priv->rq[rxq];
 304                 rcv_xdp = rcu_access_pointer(rq->xdp_prog);
 305                 skb_record_rx_queue(skb, rxq);
 306         }
 307
 308         skb_tx_timestamp(skb);
 309         if (likely(veth_forward_skb(rcv, skb, rq, rcv_xdp) == NET_RX_SUCCESS)) {
 310                 if (!rcv_xdp)
 311                         dev_lstats_add(dev, length);
 312         } else {
 313 drop:
 314                 atomic64_inc(&priv->dropped);
 315         }
 316
 317         if (rcv_xdp)
 318                 __veth_xdp_flush(rq);
 319
 320         rcu_read_unlock();
 321
 322         return NETDEV_TX_OK;
 323 }
 324
 325 static u64 veth_stats_tx(struct net_device *dev, u64 *packets, u64 *bytes)
 326 {
 327         struct veth_priv *priv = netdev_priv(dev);
 328
 329         dev_lstats_read(dev, packets, bytes);
 330         return atomic64_read(&priv->dropped);
 331 }
 332
 333 static void veth_stats_rx(struct veth_stats *result, struct net_device *dev)
 334 {
 335         struct veth_priv *priv = netdev_priv(dev);
 336         int i;
 337
 338         result->peer_tq_xdp_xmit_err = 0;
 339         result->xdp_packets = 0;
 340         result->xdp_tx_err = 0;
 341         result->xdp_bytes = 0;
 342         result->rx_drops = 0;
 343         for (i = 0; i < dev->num_rx_queues; i++) {
 344                 u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err;
 345                 struct veth_rq_stats *stats = &priv->rq[i].stats;
 346                 unsigned int start;
 347
 348                 do {
 349                         start = u64_stats_fetch_begin_irq(&stats->syncp);
 350                         peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err;
 351                         xdp_tx_err = stats->vs.xdp_tx_err;
 352                         packets = stats->vs.xdp_packets;
 353                         bytes = stats->vs.xdp_bytes;
 354                         drops = stats->vs.rx_drops;
 355                 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
 356                 result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err;
 357                 result->xdp_tx_err += xdp_tx_err;
 358                 result->xdp_packets += packets;
 359                 result->xdp_bytes += bytes;
 360                 result->rx_drops += drops;
 361         }
 362 }
 363
 364 static void veth_get_stats64(struct net_device *dev,
 365                              struct rtnl_link_stats64 *tot)
 366 {
 367         struct veth_priv *priv = netdev_priv(dev);
 368         struct net_device *peer;
 369         struct veth_stats rx;
 370         u64 packets, bytes;
 371
 372         tot->tx_dropped = veth_stats_tx(dev, &packets, &bytes);
 373         tot->tx_bytes = bytes;
 374         tot->tx_packets = packets;
 375
 376         veth_stats_rx(&rx, dev);
 377         tot->tx_dropped += rx.xdp_tx_err;
 378         tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err;
 379         tot->rx_bytes = rx.xdp_bytes;
 380         tot->rx_packets = rx.xdp_packets;
 381
 382         rcu_read_lock();
 383         peer = rcu_dereference(priv->peer);
 384         if (peer) {
 385                 veth_stats_tx(peer, &packets, &bytes);
 386                 tot->rx_bytes += bytes;
 387                 tot->rx_packets += packets;
 388
 389                 veth_stats_rx(&rx, peer);
 390                 tot->tx_dropped += rx.peer_tq_xdp_xmit_err;
 391                 tot->rx_dropped += rx.xdp_tx_err;
 392                 tot->tx_bytes += rx.xdp_bytes;
 393                 tot->tx_packets += rx.xdp_packets;
 394         }
 395         rcu_read_unlock();
 396 }
 397
 398 /* fake multicast ability */
 399 static void veth_set_multicast_list(struct net_device *dev)
 400 {
 401 }
 402
 403 static struct sk_buff *veth_build_skb(void *head, int headroom, int len,
 404                                       int buflen)
 405 {
 406         struct sk_buff *skb;
 407
 408         skb = build_skb(head, buflen);
 409         if (!skb)
 410                 return NULL;
 411
 412         skb_reserve(skb, headroom);
 413         skb_put(skb, len);
 414
 415         return skb;
 416 }
 417
 418 static int veth_select_rxq(struct net_device *dev)
 419 {
 420         return smp_processor_id() % dev->real_num_rx_queues;
 421 }
 422
 423 static struct net_device *veth_peer_dev(struct net_device *dev)
 424 {
 425         struct veth_priv *priv = netdev_priv(dev);
 426
 427         /* Callers must be under RCU read side. */
 428         return rcu_dereference(priv->peer);
 429 }
 430
 431 static int veth_xdp_xmit(struct net_device *dev, int n,
 432                          struct xdp_frame **frames,
 433                          u32 flags, bool ndo_xmit)
 434 {
 435         struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 436         int i, ret = -ENXIO, nxmit = 0;
 437         struct net_device *rcv;
 438         unsigned int max_len;
 439         struct veth_rq *rq;
 440
 441         if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
 442                 return -EINVAL;
 443
 444         rcu_read_lock();
 445         rcv = rcu_dereference(priv->peer);
 446         if (unlikely(!rcv))
 447                 goto out;
 448
 449         rcv_priv = netdev_priv(rcv);
 450         rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 451         /* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive
 452          * side. This means an XDP program is loaded on the peer and the peer
 453          * device is up.
 454          */
 455         if (!rcu_access_pointer(rq->xdp_prog))
 456                 goto out;
 457
 458         max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
 459
 460         spin_lock(&rq->xdp_ring.producer_lock);
 461         for (i = 0; i < n; i++) {
 462                 struct xdp_frame *frame = frames[i];
 463                 void *ptr = veth_xdp_to_ptr(frame);
 464
 465                 if (unlikely(frame->len > max_len ||
 466                              __ptr_ring_produce(&rq->xdp_ring, ptr)))
 467                         break;
 468                 nxmit++;
 469         }
 470         spin_unlock(&rq->xdp_ring.producer_lock);
 471
 472         if (flags & XDP_XMIT_FLUSH)
 473                 __veth_xdp_flush(rq);
 474
 475         ret = nxmit;
 476         if (ndo_xmit) {
 477                 u64_stats_update_begin(&rq->stats.syncp);
 478                 rq->stats.vs.peer_tq_xdp_xmit += nxmit;
 479                 rq->stats.vs.peer_tq_xdp_xmit_err += n - nxmit;
 480                 u64_stats_update_end(&rq->stats.syncp);
 481         }
 482
 483 out:
 484         rcu_read_unlock();
 485
 486         return ret;
 487 }
 488
 489 static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
 490                              struct xdp_frame **frames, u32 flags)
 491 {
 492         int err;
 493
 494         err = veth_xdp_xmit(dev, n, frames, flags, true);
 495         if (err < 0) {
 496                 struct veth_priv *priv = netdev_priv(dev);
 497
 498                 atomic64_add(n, &priv->dropped);
 499         }
 500
 501         return err;
 502 }
 503
 504 static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 505 {
 506         int sent, i, err = 0, drops;
 507
 508         sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false);
 509         if (sent < 0) {
 510                 err = sent;
 511                 sent = 0;
 512         }
 513
 514         for (i = sent; unlikely(i < bq->count); i++)
 515                 xdp_return_frame(bq->q[i]);
 516
 517         drops = bq->count - sent;
 518         trace_xdp_bulk_tx(rq->dev, sent, drops, err);
 519
 520         u64_stats_update_begin(&rq->stats.syncp);
 521         rq->stats.vs.xdp_tx += sent;
 522         rq->stats.vs.xdp_tx_err += drops;
 523         u64_stats_update_end(&rq->stats.syncp);
 524
 525         bq->count = 0;
 526 }
 527
 528 static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 529 {
 530         struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev);
 531         struct net_device *rcv;
 532         struct veth_rq *rcv_rq;
 533
 534         rcu_read_lock();
 535         veth_xdp_flush_bq(rq, bq);
 536         rcv = rcu_dereference(priv->peer);
 537         if (unlikely(!rcv))
 538                 goto out;
 539
 540         rcv_priv = netdev_priv(rcv);
 541         rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 542         /* xdp_ring is initialized on receive side? */
 543         if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
 544                 goto out;
 545
 546         __veth_xdp_flush(rcv_rq);
 547 out:
 548         rcu_read_unlock();
 549 }
 550
 551 static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
 552                        struct veth_xdp_tx_bq *bq)
 553 {
 554         struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
 555
 556         if (unlikely(!frame))
 557                 return -EOVERFLOW;
 558
 559         if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
 560                 veth_xdp_flush_bq(rq, bq);
 561
 562         bq->q[bq->count++] = frame;
 563
 564         return 0;
 565 }
 566
 567 static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
 568                                           struct xdp_frame *frame,
 569                                           struct veth_xdp_tx_bq *bq,
 570                                           struct veth_stats *stats)
 571 {
 572         struct xdp_frame orig_frame;
 573         struct bpf_prog *xdp_prog;
 574
 575         rcu_read_lock();
 576         xdp_prog = rcu_dereference(rq->xdp_prog);
 577         if (likely(xdp_prog)) {
 578                 struct xdp_buff xdp;
 579                 u32 act;
 580
 581                 xdp_convert_frame_to_buff(frame, &xdp);
 582                 xdp.rxq = &rq->xdp_rxq;
 583
 584                 act = bpf_prog_run_xdp(xdp_prog, &xdp);
 585
 586                 switch (act) {
 587                 case XDP_PASS:
 588                         if (xdp_update_frame_from_buff(&xdp, frame))
 589                                 goto err_xdp;
 590                         break;
 591                 case XDP_TX:
 592                         orig_frame = *frame;
 593                         xdp.rxq->mem = frame->mem;
 594                         if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {
 595                                 trace_xdp_exception(rq->dev, xdp_prog, act);
 596                                 frame = &orig_frame;
 597                                 stats->rx_drops++;
 598                                 goto err_xdp;
 599                         }
 600                         stats->xdp_tx++;
 601                         rcu_read_unlock();
 602                         goto xdp_xmit;
 603                 case XDP_REDIRECT:
 604                         orig_frame = *frame;
 605                         xdp.rxq->mem = frame->mem;
 606                         if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
 607                                 frame = &orig_frame;
 608                                 stats->rx_drops++;
 609                                 goto err_xdp;
 610                         }
 611                         stats->xdp_redirect++;
 612                         rcu_read_unlock();
 613                         goto xdp_xmit;
 614                 default:
 615                         bpf_warn_invalid_xdp_action(act);
 616                         fallthrough;
 617                 case XDP_ABORTED:
 618                         trace_xdp_exception(rq->dev, xdp_prog, act);
 619                         fallthrough;
 620                 case XDP_DROP:
 621                         stats->xdp_drops++;
 622                         goto err_xdp;
 623                 }
 624         }
 625         rcu_read_unlock();
 626
 627         return frame;
 628 err_xdp:
 629         rcu_read_unlock();
 630         xdp_return_frame(frame);
 631 xdp_xmit:
 632         return NULL;
 633 }
 634
 635 /* frames array contains VETH_XDP_BATCH at most */
 636 static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames,
 637                                   int n_xdpf, struct veth_xdp_tx_bq *bq,
 638                                   struct veth_stats *stats)
 639 {
 640         void *skbs[VETH_XDP_BATCH];
 641         int i;
 642
 643         if (xdp_alloc_skb_bulk(skbs, n_xdpf,
 644                                GFP_ATOMIC | __GFP_ZERO) < 0) {
 645                 for (i = 0; i < n_xdpf; i++)
 646                         xdp_return_frame(frames[i]);
 647                 stats->rx_drops += n_xdpf;
 648
 649                 return;
 650         }
 651
 652         for (i = 0; i < n_xdpf; i++) {
 653                 struct sk_buff *skb = skbs[i];
 654
 655                 skb = __xdp_build_skb_from_frame(frames[i], skb,
 656                                                  rq->dev);
 657                 if (!skb) {
 658                         xdp_return_frame(frames[i]);
 659                         stats->rx_drops++;
 660                         continue;
 661                 }
 662                 napi_gro_receive(&rq->xdp_napi, skb);
 663         }
 664 }
 665
 666 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 667                                         struct sk_buff *skb,
 668                                         struct veth_xdp_tx_bq *bq,
 669                                         struct veth_stats *stats)
 670 {
 671         u32 pktlen, headroom, act, metalen, frame_sz;
 672         void *orig_data, *orig_data_end;
 673         struct bpf_prog *xdp_prog;
 674         int mac_len, delta, off;
 675         struct xdp_buff xdp;
 676
 677         skb_orphan(skb);
 678
 679         rcu_read_lock();
 680         xdp_prog = rcu_dereference(rq->xdp_prog);
 681         if (unlikely(!xdp_prog)) {
 682                 rcu_read_unlock();
 683                 goto out;
 684         }
 685
 686         mac_len = skb->data - skb_mac_header(skb);
 687         pktlen = skb->len + mac_len;
 688         headroom = skb_headroom(skb) - mac_len;
 689
 690         if (skb_shared(skb) || skb_head_is_locked(skb) ||
 691             skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) {
 692                 struct sk_buff *nskb;
 693                 int size, head_off;
 694                 void *head, *start;
 695                 struct page *page;
 696
 697                 size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) +
 698                        SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 699                 if (size > PAGE_SIZE)
 700                         goto drop;
 701
 702                 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
 703                 if (!page)
 704                         goto drop;
 705
 706                 head = page_address(page);
 707                 start = head + VETH_XDP_HEADROOM;
 708                 if (skb_copy_bits(skb, -mac_len, start, pktlen)) {
 709                         page_frag_free(head);
 710                         goto drop;
 711                 }
 712
 713                 nskb = veth_build_skb(head, VETH_XDP_HEADROOM + mac_len,
 714                                       skb->len, PAGE_SIZE);
 715                 if (!nskb) {
 716                         page_frag_free(head);
 717                         goto drop;
 718                 }
 719
 720                 skb_copy_header(nskb, skb);
 721                 head_off = skb_headroom(nskb) - skb_headroom(skb);
 722                 skb_headers_offset_update(nskb, head_off);
 723                 consume_skb(skb);
 724                 skb = nskb;
 725         }
 726
 727         /* SKB "head" area always have tailroom for skb_shared_info */
 728         frame_sz = skb_end_pointer(skb) - skb->head;
 729         frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 730         xdp_init_buff(&xdp, frame_sz, &rq->xdp_rxq);
 731         xdp_prepare_buff(&xdp, skb->head, skb->mac_header, pktlen, true);
 732
 733         orig_data = xdp.data;
 734         orig_data_end = xdp.data_end;
 735
 736         act = bpf_prog_run_xdp(xdp_prog, &xdp);
 737
 738         switch (act) {
 739         case XDP_PASS:
 740                 break;
 741         case XDP_TX:
 742                 get_page(virt_to_page(xdp.data));
 743                 consume_skb(skb);
 744                 xdp.rxq->mem = rq->xdp_mem;
 745                 if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) {
 746                         trace_xdp_exception(rq->dev, xdp_prog, act);
 747                         stats->rx_drops++;
 748                         goto err_xdp;
 749                 }
 750                 stats->xdp_tx++;
 751                 rcu_read_unlock();
 752                 goto xdp_xmit;
 753         case XDP_REDIRECT:
 754                 get_page(virt_to_page(xdp.data));
 755                 consume_skb(skb);
 756                 xdp.rxq->mem = rq->xdp_mem;
 757                 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) {
 758                         stats->rx_drops++;
 759                         goto err_xdp;
 760                 }
 761                 stats->xdp_redirect++;
 762                 rcu_read_unlock();
 763                 goto xdp_xmit;
 764         default:
 765                 bpf_warn_invalid_xdp_action(act);
 766                 fallthrough;
 767         case XDP_ABORTED:
 768                 trace_xdp_exception(rq->dev, xdp_prog, act);
 769                 fallthrough;
 770         case XDP_DROP:
 771                 stats->xdp_drops++;
 772                 goto xdp_drop;
 773         }
 774         rcu_read_unlock();
 775
 776         /* check if bpf_xdp_adjust_head was used */
 777         delta = orig_data - xdp.data;
 778         off = mac_len + delta;
 779         if (off > 0)
 780                 __skb_push(skb, off);
 781         else if (off < 0)
 782                 __skb_pull(skb, -off);
 783         skb->mac_header -= delta;
 784
 785         /* check if bpf_xdp_adjust_tail was used */
 786         off = xdp.data_end - orig_data_end;
 787         if (off != 0)
 788                 __skb_put(skb, off); /* positive on grow, negative on shrink */
 789         skb->protocol = eth_type_trans(skb, rq->dev);
 790
 791         metalen = xdp.data - xdp.data_meta;
 792         if (metalen)
 793                 skb_metadata_set(skb, metalen);
 794 out:
 795         return skb;
 796 drop:
 797         stats->rx_drops++;
 798 xdp_drop:
 799         rcu_read_unlock();
 800         kfree_skb(skb);
 801         return NULL;
 802 err_xdp:
 803         rcu_read_unlock();
 804         page_frag_free(xdp.data);
 805 xdp_xmit:
 806         return NULL;
 807 }
 808
 809 static int veth_xdp_rcv(struct veth_rq *rq, int budget,
 810                         struct veth_xdp_tx_bq *bq,
 811                         struct veth_stats *stats)
 812 {
 813         int i, done = 0, n_xdpf = 0;
 814         void *xdpf[VETH_XDP_BATCH];
 815
 816         for (i = 0; i < budget; i++) {
 817                 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
 818
 819                 if (!ptr)
 820                         break;
 821
 822                 if (veth_is_xdp_frame(ptr)) {
 823                         /* ndo_xdp_xmit */
 824                         struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
 825
 826                         stats->xdp_bytes += frame->len;
 827                         frame = veth_xdp_rcv_one(rq, frame, bq, stats);
 828                         if (frame) {
 829                                 /* XDP_PASS */
 830                                 xdpf[n_xdpf++] = frame;
 831                                 if (n_xdpf == VETH_XDP_BATCH) {
 832                                         veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf,
 833                                                               bq, stats);
 834                                         n_xdpf = 0;
 835                                 }
 836                         }
 837                 } else {
 838                         /* ndo_start_xmit */
 839                         struct sk_buff *skb = ptr;
 840
 841                         stats->xdp_bytes += skb->len;
 842                         skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
 843                         if (skb)
 844                                 napi_gro_receive(&rq->xdp_napi, skb);
 845                 }
 846                 done++;
 847         }
 848
 849         if (n_xdpf)
 850                 veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats);
 851
 852         u64_stats_update_begin(&rq->stats.syncp);
 853         rq->stats.vs.xdp_redirect += stats->xdp_redirect;
 854         rq->stats.vs.xdp_bytes += stats->xdp_bytes;
 855         rq->stats.vs.xdp_drops += stats->xdp_drops;
 856         rq->stats.vs.rx_drops += stats->rx_drops;
 857         rq->stats.vs.xdp_packets += done;
 858         u64_stats_update_end(&rq->stats.syncp);
 859
 860         return done;
 861 }
 862
 863 static int veth_poll(struct napi_struct *napi, int budget)
 864 {
 865         struct veth_rq *rq =
 866                 container_of(napi, struct veth_rq, xdp_napi);
 867         struct veth_stats stats = {};
 868         struct veth_xdp_tx_bq bq;
 869         int done;
 870
 871         bq.count = 0;
 872
 873         xdp_set_return_frame_no_direct();
 874         done = veth_xdp_rcv(rq, budget, &bq, &stats);
 875
 876         if (done < budget && napi_complete_done(napi, done)) {
 877                 /* Write rx_notify_masked before reading ptr_ring */
 878                 smp_store_mb(rq->rx_notify_masked, false);
 879                 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
 880                         rq->rx_notify_masked = true;
 881                         napi_schedule(&rq->xdp_napi);
 882                 }
 883         }
 884
 885         if (stats.xdp_tx > 0)
 886                 veth_xdp_flush(rq, &bq);
 887         if (stats.xdp_redirect > 0)
 888                 xdp_do_flush();
 889         xdp_clear_return_frame_no_direct();
 890
 891         return done;
 892 }
 893
 894 static int veth_napi_add(struct net_device *dev)
 895 {
 896         struct veth_priv *priv = netdev_priv(dev);
 897         int err, i;
 898
 899         for (i = 0; i < dev->real_num_rx_queues; i++) {
 900                 struct veth_rq *rq = &priv->rq[i];
 901
 902                 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
 903                 if (err)
 904                         goto err_xdp_ring;
 905         }
 906
 907         for (i = 0; i < dev->real_num_rx_queues; i++) {
 908                 struct veth_rq *rq = &priv->rq[i];
 909
 910                 napi_enable(&rq->xdp_napi);
 911         }
 912
 913         return 0;
 914 err_xdp_ring:
 915         for (i--; i >= 0; i--)
 916                 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
 917
 918         return err;
 919 }
 920
 921 static void veth_napi_del(struct net_device *dev)
 922 {
 923         struct veth_priv *priv = netdev_priv(dev);
 924         int i;
 925
 926         for (i = 0; i < dev->real_num_rx_queues; i++) {
 927                 struct veth_rq *rq = &priv->rq[i];
 928
 929                 napi_disable(&rq->xdp_napi);
 930                 __netif_napi_del(&rq->xdp_napi);
 931         }
 932         synchronize_net();
 933
 934         for (i = 0; i < dev->real_num_rx_queues; i++) {
 935                 struct veth_rq *rq = &priv->rq[i];
 936
 937                 rq->rx_notify_masked = false;
 938                 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
 939         }
 940 }
 941
 942 static int veth_enable_xdp(struct net_device *dev)
 943 {
 944         struct veth_priv *priv = netdev_priv(dev);
 945         int err, i;
 946
 947         if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
 948                 for (i = 0; i < dev->real_num_rx_queues; i++) {
 949                         struct veth_rq *rq = &priv->rq[i];
 950
 951                         netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT);
 952                         err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id);
 953                         if (err < 0)
 954                                 goto err_rxq_reg;
 955
 956                         err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
 957                                                          MEM_TYPE_PAGE_SHARED,
 958                                                          NULL);
 959                         if (err < 0)
 960                                 goto err_reg_mem;
 961
 962                         /* Save original mem info as it can be overwritten */
 963                         rq->xdp_mem = rq->xdp_rxq.mem;
 964                 }
 965
 966                 err = veth_napi_add(dev);
 967                 if (err)
 968                         goto err_rxq_reg;
 969         }
 970
 971         for (i = 0; i < dev->real_num_rx_queues; i++)
 972                 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
 973
 974         return 0;
 975 err_reg_mem:
 976         xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
 977 err_rxq_reg:
 978         for (i--; i >= 0; i--) {
 979                 struct veth_rq *rq = &priv->rq[i];
 980
 981                 xdp_rxq_info_unreg(&rq->xdp_rxq);
 982                 netif_napi_del(&rq->xdp_napi);
 983         }
 984
 985         return err;
 986 }
 987
 988 static void veth_disable_xdp(struct net_device *dev)
 989 {
 990         struct veth_priv *priv = netdev_priv(dev);
 991         int i;
 992
 993         for (i = 0; i < dev->real_num_rx_queues; i++)
 994                 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
 995         veth_napi_del(dev);
 996         for (i = 0; i < dev->real_num_rx_queues; i++) {
 997                 struct veth_rq *rq = &priv->rq[i];
 998
 999                 rq->xdp_rxq.mem = rq->xdp_mem;
1000                 xdp_rxq_info_unreg(&rq->xdp_rxq);
1001         }
1002 }
1003
1004 static int veth_open(struct net_device *dev)
1005 {
1006         struct veth_priv *priv = netdev_priv(dev);
1007         struct net_device *peer = rtnl_dereference(priv->peer);
1008         int err;
1009
1010         if (!peer)
1011                 return -ENOTCONN;
1012
1013         if (priv->_xdp_prog) {
1014                 err = veth_enable_xdp(dev);
1015                 if (err)
1016                         return err;
1017         }
1018
1019         if (peer->flags & IFF_UP) {
1020                 netif_carrier_on(dev);
1021                 netif_carrier_on(peer);
1022         }
1023
1024         return 0;
1025 }
1026
1027 static int veth_close(struct net_device *dev)
1028 {
1029         struct veth_priv *priv = netdev_priv(dev);
1030         struct net_device *peer = rtnl_dereference(priv->peer);
1031
1032         netif_carrier_off(dev);
1033         if (peer)
1034                 netif_carrier_off(peer);
1035
1036         if (priv->_xdp_prog)
1037                 veth_disable_xdp(dev);
1038
1039         return 0;
1040 }
1041
1042 static int is_valid_veth_mtu(int mtu)
1043 {
1044         return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1045 }
1046
1047 static int veth_alloc_queues(struct net_device *dev)
1048 {
1049         struct veth_priv *priv = netdev_priv(dev);
1050         int i;
1051
1052         priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL);
1053         if (!priv->rq)
1054                 return -ENOMEM;
1055
1056         for (i = 0; i < dev->num_rx_queues; i++) {
1057                 priv->rq[i].dev = dev;
1058                 u64_stats_init(&priv->rq[i].stats.syncp);
1059         }
1060
1061         return 0;
1062 }
1063
1064 static void veth_free_queues(struct net_device *dev)
1065 {
1066         struct veth_priv *priv = netdev_priv(dev);
1067
1068         kfree(priv->rq);
1069 }
1070
1071 static int veth_dev_init(struct net_device *dev)
1072 {
1073         int err;
1074
1075         dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
1076         if (!dev->lstats)
1077                 return -ENOMEM;
1078
1079         err = veth_alloc_queues(dev);
1080         if (err) {
1081                 free_percpu(dev->lstats);
1082                 return err;
1083         }
1084
1085         return 0;
1086 }
1087
1088 static void veth_dev_free(struct net_device *dev)
1089 {
1090         veth_free_queues(dev);
1091         free_percpu(dev->lstats);
1092 }
1093
1094 #ifdef CONFIG_NET_POLL_CONTROLLER
1095 static void veth_poll_controller(struct net_device *dev)
1096 {
1097         /* veth only receives frames when its peer sends one
1098          * Since it has nothing to do with disabling irqs, we are guaranteed
1099          * never to have pending data when we poll for it so
1100          * there is nothing to do here.
1101          *
1102          * We need this though so netpoll recognizes us as an interface that
1103          * supports polling, which enables bridge devices in virt setups to
1104          * still use netconsole
1105          */
1106 }
1107 #endif  /* CONFIG_NET_POLL_CONTROLLER */
1108
1109 static int veth_get_iflink(const struct net_device *dev)
1110 {
1111         struct veth_priv *priv = netdev_priv(dev);
1112         struct net_device *peer;
1113         int iflink;
1114
1115         rcu_read_lock();
1116         peer = rcu_dereference(priv->peer);
1117         iflink = peer ? peer->ifindex : 0;
1118         rcu_read_unlock();
1119
1120         return iflink;
1121 }
1122
1123 static netdev_features_t veth_fix_features(struct net_device *dev,
1124                                            netdev_features_t features)
1125 {
1126         struct veth_priv *priv = netdev_priv(dev);
1127         struct net_device *peer;
1128
1129         peer = rtnl_dereference(priv->peer);
1130         if (peer) {
1131                 struct veth_priv *peer_priv = netdev_priv(peer);
1132
1133                 if (peer_priv->_xdp_prog)
1134                         features &= ~NETIF_F_GSO_SOFTWARE;
1135         }
1136
1137         return features;
1138 }
1139
1140 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1141 {
1142         struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1143         struct net_device *peer;
1144
1145         if (new_hr < 0)
1146                 new_hr = 0;
1147
1148         rcu_read_lock();
1149         peer = rcu_dereference(priv->peer);
1150         if (unlikely(!peer))
1151                 goto out;
1152
1153         peer_priv = netdev_priv(peer);
1154         priv->requested_headroom = new_hr;
1155         new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1156         dev->needed_headroom = new_hr;
1157         peer->needed_headroom = new_hr;
1158
1159 out:
1160         rcu_read_unlock();
1161 }
1162
1163 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1164                         struct netlink_ext_ack *extack)
1165 {
1166         struct veth_priv *priv = netdev_priv(dev);
1167         struct bpf_prog *old_prog;
1168         struct net_device *peer;
1169         unsigned int max_mtu;
1170         int err;
1171
1172         old_prog = priv->_xdp_prog;
1173         priv->_xdp_prog = prog;
1174         peer = rtnl_dereference(priv->peer);
1175
1176         if (prog) {
1177                 if (!peer) {
1178                         NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1179                         err = -ENOTCONN;
1180                         goto err;
1181                 }
1182
1183                 max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM -
1184                           peer->hard_header_len -
1185                           SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
1186                 if (peer->mtu > max_mtu) {
1187                         NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1188                         err = -ERANGE;
1189                         goto err;
1190                 }
1191
1192                 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1193                         NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1194                         err = -ENOSPC;
1195                         goto err;
1196                 }
1197
1198                 if (dev->flags & IFF_UP) {
1199                         err = veth_enable_xdp(dev);
1200                         if (err) {
1201                                 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1202                                 goto err;
1203                         }
1204                 }
1205
1206                 if (!old_prog) {
1207                         peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1208                         peer->max_mtu = max_mtu;
1209                 }
1210         }
1211
1212         if (old_prog) {
1213                 if (!prog) {
1214                         if (dev->flags & IFF_UP)
1215                                 veth_disable_xdp(dev);
1216
1217                         if (peer) {
1218                                 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1219                                 peer->max_mtu = ETH_MAX_MTU;
1220                         }
1221                 }
1222                 bpf_prog_put(old_prog);
1223         }
1224
1225         if ((!!old_prog ^ !!prog) && peer)
1226                 netdev_update_features(peer);
1227
1228         return 0;
1229 err:
1230         priv->_xdp_prog = old_prog;
1231
1232         return err;
1233 }
1234
1235 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1236 {
1237         switch (xdp->command) {
1238         case XDP_SETUP_PROG:
1239                 return veth_xdp_set(dev, xdp->prog, xdp->extack);
1240         default:
1241                 return -EINVAL;
1242         }
1243 }
1244
1245 static const struct net_device_ops veth_netdev_ops = {
1246         .ndo_init            = veth_dev_init,
1247         .ndo_open            = veth_open,
1248         .ndo_stop            = veth_close,
1249         .ndo_start_xmit      = veth_xmit,
1250         .ndo_get_stats64     = veth_get_stats64,
1251         .ndo_set_rx_mode     = veth_set_multicast_list,
1252         .ndo_set_mac_address = eth_mac_addr,
1253 #ifdef CONFIG_NET_POLL_CONTROLLER
1254         .ndo_poll_controller    = veth_poll_controller,
1255 #endif
1256         .ndo_get_iflink         = veth_get_iflink,
1257         .ndo_fix_features       = veth_fix_features,
1258         .ndo_features_check     = passthru_features_check,
1259         .ndo_set_rx_headroom    = veth_set_rx_headroom,
1260         .ndo_bpf                = veth_xdp,
1261         .ndo_xdp_xmit           = veth_ndo_xdp_xmit,
1262         .ndo_get_peer_dev       = veth_peer_dev,
1263 };
1264
1265 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1266                        NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1267                        NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1268                        NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1269                        NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1270
1271 static void veth_setup(struct net_device *dev)
1272 {
1273         ether_setup(dev);
1274
1275         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1276         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1277         dev->priv_flags |= IFF_NO_QUEUE;
1278         dev->priv_flags |= IFF_PHONY_HEADROOM;
1279
1280         dev->netdev_ops = &veth_netdev_ops;
1281         dev->ethtool_ops = &veth_ethtool_ops;
1282         dev->features |= NETIF_F_LLTX;
1283         dev->features |= VETH_FEATURES;
1284         dev->vlan_features = dev->features &
1285                              ~(NETIF_F_HW_VLAN_CTAG_TX |
1286                                NETIF_F_HW_VLAN_STAG_TX |
1287                                NETIF_F_HW_VLAN_CTAG_RX |
1288                                NETIF_F_HW_VLAN_STAG_RX);
1289         dev->needs_free_netdev = true;
1290         dev->priv_destructor = veth_dev_free;
1291         dev->max_mtu = ETH_MAX_MTU;
1292
1293         dev->hw_features = VETH_FEATURES;
1294         dev->hw_enc_features = VETH_FEATURES;
1295         dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1296 }
1297
1298 /*
1299  * netlink interface
1300  */
1301
1302 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1303                          struct netlink_ext_ack *extack)
1304 {
1305         if (tb[IFLA_ADDRESS]) {
1306                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1307                         return -EINVAL;
1308                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1309                         return -EADDRNOTAVAIL;
1310         }
1311         if (tb[IFLA_MTU]) {
1312                 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1313                         return -EINVAL;
1314         }
1315         return 0;
1316 }
1317
1318 static struct rtnl_link_ops veth_link_ops;
1319
1320 static int veth_newlink(struct net *src_net, struct net_device *dev,
1321                         struct nlattr *tb[], struct nlattr *data[],
1322                         struct netlink_ext_ack *extack)
1323 {
1324         int err;
1325         struct net_device *peer;
1326         struct veth_priv *priv;
1327         char ifname[IFNAMSIZ];
1328         struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1329         unsigned char name_assign_type;
1330         struct ifinfomsg *ifmp;
1331         struct net *net;
1332
1333         /*
1334          * create and register peer first
1335          */
1336         if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1337                 struct nlattr *nla_peer;
1338
1339                 nla_peer = data[VETH_INFO_PEER];
1340                 ifmp = nla_data(nla_peer);
1341                 err = rtnl_nla_parse_ifla(peer_tb,
1342                                           nla_data(nla_peer) + sizeof(struct ifinfomsg),
1343                                           nla_len(nla_peer) - sizeof(struct ifinfomsg),
1344                                           NULL);
1345                 if (err < 0)
1346                         return err;
1347
1348                 err = veth_validate(peer_tb, NULL, extack);
1349                 if (err < 0)
1350                         return err;
1351
1352                 tbp = peer_tb;
1353         } else {
1354                 ifmp = NULL;
1355                 tbp = tb;
1356         }
1357
1358         if (ifmp && tbp[IFLA_IFNAME]) {
1359                 nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1360                 name_assign_type = NET_NAME_USER;
1361         } else {
1362                 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1363                 name_assign_type = NET_NAME_ENUM;
1364         }
1365
1366         net = rtnl_link_get_net(src_net, tbp);
1367         if (IS_ERR(net))
1368                 return PTR_ERR(net);
1369
1370         peer = rtnl_create_link(net, ifname, name_assign_type,
1371                                 &veth_link_ops, tbp, extack);
1372         if (IS_ERR(peer)) {
1373                 put_net(net);
1374                 return PTR_ERR(peer);
1375         }
1376
1377         if (!ifmp || !tbp[IFLA_ADDRESS])
1378                 eth_hw_addr_random(peer);
1379
1380         if (ifmp && (dev->ifindex != 0))
1381                 peer->ifindex = ifmp->ifi_index;
1382
1383         peer->gso_max_size = dev->gso_max_size;
1384         peer->gso_max_segs = dev->gso_max_segs;
1385
1386         err = register_netdevice(peer);
1387         put_net(net);
1388         net = NULL;
1389         if (err < 0)
1390                 goto err_register_peer;
1391
1392         netif_carrier_off(peer);
1393
1394         err = rtnl_configure_link(peer, ifmp);
1395         if (err < 0)
1396                 goto err_configure_peer;
1397
1398         /*
1399          * register dev last
1400          *
1401          * note, that since we've registered new device the dev's name
1402          * should be re-allocated
1403          */
1404
1405         if (tb[IFLA_ADDRESS] == NULL)
1406                 eth_hw_addr_random(dev);
1407
1408         if (tb[IFLA_IFNAME])
1409                 nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1410         else
1411                 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1412
1413         err = register_netdevice(dev);
1414         if (err < 0)
1415                 goto err_register_dev;
1416
1417         netif_carrier_off(dev);
1418
1419         /*
1420          * tie the deviced together
1421          */
1422
1423         priv = netdev_priv(dev);
1424         rcu_assign_pointer(priv->peer, peer);
1425
1426         priv = netdev_priv(peer);
1427         rcu_assign_pointer(priv->peer, dev);
1428
1429         return 0;
1430
1431 err_register_dev:
1432         /* nothing to do */
1433 err_configure_peer:
1434         unregister_netdevice(peer);
1435         return err;
1436
1437 err_register_peer:
1438         free_netdev(peer);
1439         return err;
1440 }
1441
1442 static void veth_dellink(struct net_device *dev, struct list_head *head)
1443 {
1444         struct veth_priv *priv;
1445         struct net_device *peer;
1446
1447         priv = netdev_priv(dev);
1448         peer = rtnl_dereference(priv->peer);
1449
1450         /* Note : dellink() is called from default_device_exit_batch(),
1451          * before a rcu_synchronize() point. The devices are guaranteed
1452          * not being freed before one RCU grace period.
1453          */
1454         RCU_INIT_POINTER(priv->peer, NULL);
1455         unregister_netdevice_queue(dev, head);
1456
1457         if (peer) {
1458                 priv = netdev_priv(peer);
1459                 RCU_INIT_POINTER(priv->peer, NULL);
1460                 unregister_netdevice_queue(peer, head);
1461         }
1462 }
1463
1464 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1465         [VETH_INFO_PEER]        = { .len = sizeof(struct ifinfomsg) },
1466 };
1467
1468 static struct net *veth_get_link_net(const struct net_device *dev)
1469 {
1470         struct veth_priv *priv = netdev_priv(dev);
1471         struct net_device *peer = rtnl_dereference(priv->peer);
1472
1473         return peer ? dev_net(peer) : dev_net(dev);
1474 }
1475
1476 static struct rtnl_link_ops veth_link_ops = {
1477         .kind           = DRV_NAME,
1478         .priv_size      = sizeof(struct veth_priv),
1479         .setup          = veth_setup,
1480         .validate       = veth_validate,
1481         .newlink        = veth_newlink,
1482         .dellink        = veth_dellink,
1483         .policy         = veth_policy,
1484         .maxtype        = VETH_INFO_MAX,
1485         .get_link_net   = veth_get_link_net,
1486 };
1487
1488 /*
1489  * init/fini
1490  */
1491
1492 static __init int veth_init(void)
1493 {
1494         return rtnl_link_register(&veth_link_ops);
1495 }
1496
1497 static __exit void veth_exit(void)
1498 {
1499         rtnl_link_unregister(&veth_link_ops);
1500 }
1501
1502 module_init(veth_init);
1503 module_exit(veth_exit);
1504
1505 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1506 MODULE_LICENSE("GPL v2");
1507 MODULE_ALIAS_RTNL_LINK(DRV_NAME);