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 #include <net/page_pool/helpers.h>
  30
  31 #define DRV_NAME        "veth"
  32 #define DRV_VERSION     "1.0"
  33
  34 #define VETH_XDP_FLAG           BIT(0)
  35 #define VETH_RING_SIZE          256
  36 #define VETH_XDP_HEADROOM       (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
  37
  38 #define VETH_XDP_TX_BULK_SIZE   16
  39 #define VETH_XDP_BATCH          16
  40
  41 struct veth_stats {
  42         u64     rx_drops;
  43         /* xdp */
  44         u64     xdp_packets;
  45         u64     xdp_bytes;
  46         u64     xdp_redirect;
  47         u64     xdp_drops;
  48         u64     xdp_tx;
  49         u64     xdp_tx_err;
  50         u64     peer_tq_xdp_xmit;
  51         u64     peer_tq_xdp_xmit_err;
  52 };
  53
  54 struct veth_rq_stats {
  55         struct veth_stats       vs;
  56         struct u64_stats_sync   syncp;
  57 };
  58
  59 struct veth_rq {
  60         struct napi_struct      xdp_napi;
  61         struct napi_struct __rcu *napi; /* points to xdp_napi when the latter is initialized */
  62         struct net_device       *dev;
  63         struct bpf_prog __rcu   *xdp_prog;
  64         struct xdp_mem_info     xdp_mem;
  65         struct veth_rq_stats    stats;
  66         bool                    rx_notify_masked;
  67         struct ptr_ring         xdp_ring;
  68         struct xdp_rxq_info     xdp_rxq;
  69         struct page_pool        *page_pool;
  70 };
  71
  72 struct veth_priv {
  73         struct net_device __rcu *peer;
  74         atomic64_t              dropped;
  75         struct bpf_prog         *_xdp_prog;
  76         struct veth_rq          *rq;
  77         unsigned int            requested_headroom;
  78 };
  79
  80 struct veth_xdp_tx_bq {
  81         struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
  82         unsigned int count;
  83 };
  84
  85 /*
  86  * ethtool interface
  87  */
  88
  89 struct veth_q_stat_desc {
  90         char    desc[ETH_GSTRING_LEN];
  91         size_t  offset;
  92 };
  93
  94 #define VETH_RQ_STAT(m) offsetof(struct veth_stats, m)
  95
  96 static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
  97         { "xdp_packets",        VETH_RQ_STAT(xdp_packets) },
  98         { "xdp_bytes",          VETH_RQ_STAT(xdp_bytes) },
  99         { "drops",              VETH_RQ_STAT(rx_drops) },
 100         { "xdp_redirect",       VETH_RQ_STAT(xdp_redirect) },
 101         { "xdp_drops",          VETH_RQ_STAT(xdp_drops) },
 102         { "xdp_tx",             VETH_RQ_STAT(xdp_tx) },
 103         { "xdp_tx_errors",      VETH_RQ_STAT(xdp_tx_err) },
 104 };
 105
 106 #define VETH_RQ_STATS_LEN       ARRAY_SIZE(veth_rq_stats_desc)
 107
 108 static const struct veth_q_stat_desc veth_tq_stats_desc[] = {
 109         { "xdp_xmit",           VETH_RQ_STAT(peer_tq_xdp_xmit) },
 110         { "xdp_xmit_errors",    VETH_RQ_STAT(peer_tq_xdp_xmit_err) },
 111 };
 112
 113 #define VETH_TQ_STATS_LEN       ARRAY_SIZE(veth_tq_stats_desc)
 114
 115 static struct {
 116         const char string[ETH_GSTRING_LEN];
 117 } ethtool_stats_keys[] = {
 118         { "peer_ifindex" },
 119 };
 120
 121 struct veth_xdp_buff {
 122         struct xdp_buff xdp;
 123         struct sk_buff *skb;
 124 };
 125
 126 static int veth_get_link_ksettings(struct net_device *dev,
 127                                    struct ethtool_link_ksettings *cmd)
 128 {
 129         cmd->base.speed         = SPEED_10000;
 130         cmd->base.duplex        = DUPLEX_FULL;
 131         cmd->base.port          = PORT_TP;
 132         cmd->base.autoneg       = AUTONEG_DISABLE;
 133         return 0;
 134 }
 135
 136 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 137 {
 138         strscpy(info->driver, DRV_NAME, sizeof(info->driver));
 139         strscpy(info->version, DRV_VERSION, sizeof(info->version));
 140 }
 141
 142 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
 143 {
 144         u8 *p = buf;
 145         int i, j;
 146
 147         switch(stringset) {
 148         case ETH_SS_STATS:
 149                 memcpy(p, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
 150                 p += sizeof(ethtool_stats_keys);
 151                 for (i = 0; i < dev->real_num_rx_queues; i++)
 152                         for (j = 0; j < VETH_RQ_STATS_LEN; j++)
 153                                 ethtool_sprintf(&p, "rx_queue_%u_%.18s",
 154                                                 i, veth_rq_stats_desc[j].desc);
 155
 156                 for (i = 0; i < dev->real_num_tx_queues; i++)
 157                         for (j = 0; j < VETH_TQ_STATS_LEN; j++)
 158                                 ethtool_sprintf(&p, "tx_queue_%u_%.18s",
 159                                                 i, veth_tq_stats_desc[j].desc);
 160
 161                 page_pool_ethtool_stats_get_strings(p);
 162                 break;
 163         }
 164 }
 165
 166 static int veth_get_sset_count(struct net_device *dev, int sset)
 167 {
 168         switch (sset) {
 169         case ETH_SS_STATS:
 170                 return ARRAY_SIZE(ethtool_stats_keys) +
 171                        VETH_RQ_STATS_LEN * dev->real_num_rx_queues +
 172                        VETH_TQ_STATS_LEN * dev->real_num_tx_queues +
 173                        page_pool_ethtool_stats_get_count();
 174         default:
 175                 return -EOPNOTSUPP;
 176         }
 177 }
 178
 179 static void veth_get_page_pool_stats(struct net_device *dev, u64 *data)
 180 {
 181 #ifdef CONFIG_PAGE_POOL_STATS
 182         struct veth_priv *priv = netdev_priv(dev);
 183         struct page_pool_stats pp_stats = {};
 184         int i;
 185
 186         for (i = 0; i < dev->real_num_rx_queues; i++) {
 187                 if (!priv->rq[i].page_pool)
 188                         continue;
 189                 page_pool_get_stats(priv->rq[i].page_pool, &pp_stats);
 190         }
 191         page_pool_ethtool_stats_get(data, &pp_stats);
 192 #endif /* CONFIG_PAGE_POOL_STATS */
 193 }
 194
 195 static void veth_get_ethtool_stats(struct net_device *dev,
 196                 struct ethtool_stats *stats, u64 *data)
 197 {
 198         struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 199         struct net_device *peer = rtnl_dereference(priv->peer);
 200         int i, j, idx, pp_idx;
 201
 202         data[0] = peer ? peer->ifindex : 0;
 203         idx = 1;
 204         for (i = 0; i < dev->real_num_rx_queues; i++) {
 205                 const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
 206                 const void *stats_base = (void *)&rq_stats->vs;
 207                 unsigned int start;
 208                 size_t offset;
 209
 210                 do {
 211                         start = u64_stats_fetch_begin(&rq_stats->syncp);
 212                         for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
 213                                 offset = veth_rq_stats_desc[j].offset;
 214                                 data[idx + j] = *(u64 *)(stats_base + offset);
 215                         }
 216                 } while (u64_stats_fetch_retry(&rq_stats->syncp, start));
 217                 idx += VETH_RQ_STATS_LEN;
 218         }
 219         pp_idx = idx;
 220
 221         if (!peer)
 222                 goto page_pool_stats;
 223
 224         rcv_priv = netdev_priv(peer);
 225         for (i = 0; i < peer->real_num_rx_queues; i++) {
 226                 const struct veth_rq_stats *rq_stats = &rcv_priv->rq[i].stats;
 227                 const void *base = (void *)&rq_stats->vs;
 228                 unsigned int start, tx_idx = idx;
 229                 size_t offset;
 230
 231                 tx_idx += (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN;
 232                 do {
 233                         start = u64_stats_fetch_begin(&rq_stats->syncp);
 234                         for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
 235                                 offset = veth_tq_stats_desc[j].offset;
 236                                 data[tx_idx + j] += *(u64 *)(base + offset);
 237                         }
 238                 } while (u64_stats_fetch_retry(&rq_stats->syncp, start));
 239                 pp_idx = tx_idx + VETH_TQ_STATS_LEN;
 240         }
 241
 242 page_pool_stats:
 243         veth_get_page_pool_stats(dev, &data[pp_idx]);
 244 }
 245
 246 static void veth_get_channels(struct net_device *dev,
 247                               struct ethtool_channels *channels)
 248 {
 249         channels->tx_count = dev->real_num_tx_queues;
 250         channels->rx_count = dev->real_num_rx_queues;
 251         channels->max_tx = dev->num_tx_queues;
 252         channels->max_rx = dev->num_rx_queues;
 253 }
 254
 255 static int veth_set_channels(struct net_device *dev,
 256                              struct ethtool_channels *ch);
 257
 258 static const struct ethtool_ops veth_ethtool_ops = {
 259         .get_drvinfo            = veth_get_drvinfo,
 260         .get_link               = ethtool_op_get_link,
 261         .get_strings            = veth_get_strings,
 262         .get_sset_count         = veth_get_sset_count,
 263         .get_ethtool_stats      = veth_get_ethtool_stats,
 264         .get_link_ksettings     = veth_get_link_ksettings,
 265         .get_ts_info            = ethtool_op_get_ts_info,
 266         .get_channels           = veth_get_channels,
 267         .set_channels           = veth_set_channels,
 268 };
 269
 270 /* general routines */
 271
 272 static bool veth_is_xdp_frame(void *ptr)
 273 {
 274         return (unsigned long)ptr & VETH_XDP_FLAG;
 275 }
 276
 277 static struct xdp_frame *veth_ptr_to_xdp(void *ptr)
 278 {
 279         return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
 280 }
 281
 282 static void *veth_xdp_to_ptr(struct xdp_frame *xdp)
 283 {
 284         return (void *)((unsigned long)xdp | VETH_XDP_FLAG);
 285 }
 286
 287 static void veth_ptr_free(void *ptr)
 288 {
 289         if (veth_is_xdp_frame(ptr))
 290                 xdp_return_frame(veth_ptr_to_xdp(ptr));
 291         else
 292                 kfree_skb(ptr);
 293 }
 294
 295 static void __veth_xdp_flush(struct veth_rq *rq)
 296 {
 297         /* Write ptr_ring before reading rx_notify_masked */
 298         smp_mb();
 299         if (!READ_ONCE(rq->rx_notify_masked) &&
 300             napi_schedule_prep(&rq->xdp_napi)) {
 301                 WRITE_ONCE(rq->rx_notify_masked, true);
 302                 __napi_schedule(&rq->xdp_napi);
 303         }
 304 }
 305
 306 static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
 307 {
 308         if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
 309                 dev_kfree_skb_any(skb);
 310                 return NET_RX_DROP;
 311         }
 312
 313         return NET_RX_SUCCESS;
 314 }
 315
 316 static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
 317                             struct veth_rq *rq, bool xdp)
 318 {
 319         return __dev_forward_skb(dev, skb) ?: xdp ?
 320                 veth_xdp_rx(rq, skb) :
 321                 __netif_rx(skb);
 322 }
 323
 324 /* return true if the specified skb has chances of GRO aggregation
 325  * Don't strive for accuracy, but try to avoid GRO overhead in the most
 326  * common scenarios.
 327  * When XDP is enabled, all traffic is considered eligible, as the xmit
 328  * device has TSO off.
 329  * When TSO is enabled on the xmit device, we are likely interested only
 330  * in UDP aggregation, explicitly check for that if the skb is suspected
 331  * - the sock_wfree destructor is used by UDP, ICMP and XDP sockets -
 332  * to belong to locally generated UDP traffic.
 333  */
 334 static bool veth_skb_is_eligible_for_gro(const struct net_device *dev,
 335                                          const struct net_device *rcv,
 336                                          const struct sk_buff *skb)
 337 {
 338         return !(dev->features & NETIF_F_ALL_TSO) ||
 339                 (skb->destructor == sock_wfree &&
 340                  rcv->features & (NETIF_F_GRO_FRAGLIST | NETIF_F_GRO_UDP_FWD));
 341 }
 342
 343 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 344 {
 345         struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 346         struct veth_rq *rq = NULL;
 347         int ret = NETDEV_TX_OK;
 348         struct net_device *rcv;
 349         int length = skb->len;
 350         bool use_napi = false;
 351         int rxq;
 352
 353         rcu_read_lock();
 354         rcv = rcu_dereference(priv->peer);
 355         if (unlikely(!rcv) || !pskb_may_pull(skb, ETH_HLEN)) {
 356                 kfree_skb(skb);
 357                 goto drop;
 358         }
 359
 360         rcv_priv = netdev_priv(rcv);
 361         rxq = skb_get_queue_mapping(skb);
 362         if (rxq < rcv->real_num_rx_queues) {
 363                 rq = &rcv_priv->rq[rxq];
 364
 365                 /* The napi pointer is available when an XDP program is
 366                  * attached or when GRO is enabled
 367                  * Don't bother with napi/GRO if the skb can't be aggregated
 368                  */
 369                 use_napi = rcu_access_pointer(rq->napi) &&
 370                            veth_skb_is_eligible_for_gro(dev, rcv, skb);
 371         }
 372
 373         skb_tx_timestamp(skb);
 374         if (likely(veth_forward_skb(rcv, skb, rq, use_napi) == NET_RX_SUCCESS)) {
 375                 if (!use_napi)
 376                         dev_lstats_add(dev, length);
 377                 else
 378                         __veth_xdp_flush(rq);
 379         } else {
 380 drop:
 381                 atomic64_inc(&priv->dropped);
 382                 ret = NET_XMIT_DROP;
 383         }
 384
 385         rcu_read_unlock();
 386
 387         return ret;
 388 }
 389
 390 static u64 veth_stats_tx(struct net_device *dev, u64 *packets, u64 *bytes)
 391 {
 392         struct veth_priv *priv = netdev_priv(dev);
 393
 394         dev_lstats_read(dev, packets, bytes);
 395         return atomic64_read(&priv->dropped);
 396 }
 397
 398 static void veth_stats_rx(struct veth_stats *result, struct net_device *dev)
 399 {
 400         struct veth_priv *priv = netdev_priv(dev);
 401         int i;
 402
 403         result->peer_tq_xdp_xmit_err = 0;
 404         result->xdp_packets = 0;
 405         result->xdp_tx_err = 0;
 406         result->xdp_bytes = 0;
 407         result->rx_drops = 0;
 408         for (i = 0; i < dev->num_rx_queues; i++) {
 409                 u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err;
 410                 struct veth_rq_stats *stats = &priv->rq[i].stats;
 411                 unsigned int start;
 412
 413                 do {
 414                         start = u64_stats_fetch_begin(&stats->syncp);
 415                         peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err;
 416                         xdp_tx_err = stats->vs.xdp_tx_err;
 417                         packets = stats->vs.xdp_packets;
 418                         bytes = stats->vs.xdp_bytes;
 419                         drops = stats->vs.rx_drops;
 420                 } while (u64_stats_fetch_retry(&stats->syncp, start));
 421                 result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err;
 422                 result->xdp_tx_err += xdp_tx_err;
 423                 result->xdp_packets += packets;
 424                 result->xdp_bytes += bytes;
 425                 result->rx_drops += drops;
 426         }
 427 }
 428
 429 static void veth_get_stats64(struct net_device *dev,
 430                              struct rtnl_link_stats64 *tot)
 431 {
 432         struct veth_priv *priv = netdev_priv(dev);
 433         struct net_device *peer;
 434         struct veth_stats rx;
 435         u64 packets, bytes;
 436
 437         tot->tx_dropped = veth_stats_tx(dev, &packets, &bytes);
 438         tot->tx_bytes = bytes;
 439         tot->tx_packets = packets;
 440
 441         veth_stats_rx(&rx, dev);
 442         tot->tx_dropped += rx.xdp_tx_err;
 443         tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err;
 444         tot->rx_bytes = rx.xdp_bytes;
 445         tot->rx_packets = rx.xdp_packets;
 446
 447         rcu_read_lock();
 448         peer = rcu_dereference(priv->peer);
 449         if (peer) {
 450                 veth_stats_tx(peer, &packets, &bytes);
 451                 tot->rx_bytes += bytes;
 452                 tot->rx_packets += packets;
 453
 454                 veth_stats_rx(&rx, peer);
 455                 tot->tx_dropped += rx.peer_tq_xdp_xmit_err;
 456                 tot->rx_dropped += rx.xdp_tx_err;
 457                 tot->tx_bytes += rx.xdp_bytes;
 458                 tot->tx_packets += rx.xdp_packets;
 459         }
 460         rcu_read_unlock();
 461 }
 462
 463 /* fake multicast ability */
 464 static void veth_set_multicast_list(struct net_device *dev)
 465 {
 466 }
 467
 468 static int veth_select_rxq(struct net_device *dev)
 469 {
 470         return smp_processor_id() % dev->real_num_rx_queues;
 471 }
 472
 473 static struct net_device *veth_peer_dev(struct net_device *dev)
 474 {
 475         struct veth_priv *priv = netdev_priv(dev);
 476
 477         /* Callers must be under RCU read side. */
 478         return rcu_dereference(priv->peer);
 479 }
 480
 481 static int veth_xdp_xmit(struct net_device *dev, int n,
 482                          struct xdp_frame **frames,
 483                          u32 flags, bool ndo_xmit)
 484 {
 485         struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 486         int i, ret = -ENXIO, nxmit = 0;
 487         struct net_device *rcv;
 488         unsigned int max_len;
 489         struct veth_rq *rq;
 490
 491         if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
 492                 return -EINVAL;
 493
 494         rcu_read_lock();
 495         rcv = rcu_dereference(priv->peer);
 496         if (unlikely(!rcv))
 497                 goto out;
 498
 499         rcv_priv = netdev_priv(rcv);
 500         rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 501         /* The napi pointer is set if NAPI is enabled, which ensures that
 502          * xdp_ring is initialized on receive side and the peer device is up.
 503          */
 504         if (!rcu_access_pointer(rq->napi))
 505                 goto out;
 506
 507         max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
 508
 509         spin_lock(&rq->xdp_ring.producer_lock);
 510         for (i = 0; i < n; i++) {
 511                 struct xdp_frame *frame = frames[i];
 512                 void *ptr = veth_xdp_to_ptr(frame);
 513
 514                 if (unlikely(xdp_get_frame_len(frame) > max_len ||
 515                              __ptr_ring_produce(&rq->xdp_ring, ptr)))
 516                         break;
 517                 nxmit++;
 518         }
 519         spin_unlock(&rq->xdp_ring.producer_lock);
 520
 521         if (flags & XDP_XMIT_FLUSH)
 522                 __veth_xdp_flush(rq);
 523
 524         ret = nxmit;
 525         if (ndo_xmit) {
 526                 u64_stats_update_begin(&rq->stats.syncp);
 527                 rq->stats.vs.peer_tq_xdp_xmit += nxmit;
 528                 rq->stats.vs.peer_tq_xdp_xmit_err += n - nxmit;
 529                 u64_stats_update_end(&rq->stats.syncp);
 530         }
 531
 532 out:
 533         rcu_read_unlock();
 534
 535         return ret;
 536 }
 537
 538 static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
 539                              struct xdp_frame **frames, u32 flags)
 540 {
 541         int err;
 542
 543         err = veth_xdp_xmit(dev, n, frames, flags, true);
 544         if (err < 0) {
 545                 struct veth_priv *priv = netdev_priv(dev);
 546
 547                 atomic64_add(n, &priv->dropped);
 548         }
 549
 550         return err;
 551 }
 552
 553 static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 554 {
 555         int sent, i, err = 0, drops;
 556
 557         sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false);
 558         if (sent < 0) {
 559                 err = sent;
 560                 sent = 0;
 561         }
 562
 563         for (i = sent; unlikely(i < bq->count); i++)
 564                 xdp_return_frame(bq->q[i]);
 565
 566         drops = bq->count - sent;
 567         trace_xdp_bulk_tx(rq->dev, sent, drops, err);
 568
 569         u64_stats_update_begin(&rq->stats.syncp);
 570         rq->stats.vs.xdp_tx += sent;
 571         rq->stats.vs.xdp_tx_err += drops;
 572         u64_stats_update_end(&rq->stats.syncp);
 573
 574         bq->count = 0;
 575 }
 576
 577 static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 578 {
 579         struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev);
 580         struct net_device *rcv;
 581         struct veth_rq *rcv_rq;
 582
 583         rcu_read_lock();
 584         veth_xdp_flush_bq(rq, bq);
 585         rcv = rcu_dereference(priv->peer);
 586         if (unlikely(!rcv))
 587                 goto out;
 588
 589         rcv_priv = netdev_priv(rcv);
 590         rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 591         /* xdp_ring is initialized on receive side? */
 592         if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
 593                 goto out;
 594
 595         __veth_xdp_flush(rcv_rq);
 596 out:
 597         rcu_read_unlock();
 598 }
 599
 600 static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
 601                        struct veth_xdp_tx_bq *bq)
 602 {
 603         struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
 604
 605         if (unlikely(!frame))
 606                 return -EOVERFLOW;
 607
 608         if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
 609                 veth_xdp_flush_bq(rq, bq);
 610
 611         bq->q[bq->count++] = frame;
 612
 613         return 0;
 614 }
 615
 616 static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
 617                                           struct xdp_frame *frame,
 618                                           struct veth_xdp_tx_bq *bq,
 619                                           struct veth_stats *stats)
 620 {
 621         struct xdp_frame orig_frame;
 622         struct bpf_prog *xdp_prog;
 623
 624         rcu_read_lock();
 625         xdp_prog = rcu_dereference(rq->xdp_prog);
 626         if (likely(xdp_prog)) {
 627                 struct veth_xdp_buff vxbuf;
 628                 struct xdp_buff *xdp = &vxbuf.xdp;
 629                 u32 act;
 630
 631                 xdp_convert_frame_to_buff(frame, xdp);
 632                 xdp->rxq = &rq->xdp_rxq;
 633                 vxbuf.skb = NULL;
 634
 635                 act = bpf_prog_run_xdp(xdp_prog, xdp);
 636
 637                 switch (act) {
 638                 case XDP_PASS:
 639                         if (xdp_update_frame_from_buff(xdp, frame))
 640                                 goto err_xdp;
 641                         break;
 642                 case XDP_TX:
 643                         orig_frame = *frame;
 644                         xdp->rxq->mem = frame->mem;
 645                         if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
 646                                 trace_xdp_exception(rq->dev, xdp_prog, act);
 647                                 frame = &orig_frame;
 648                                 stats->rx_drops++;
 649                                 goto err_xdp;
 650                         }
 651                         stats->xdp_tx++;
 652                         rcu_read_unlock();
 653                         goto xdp_xmit;
 654                 case XDP_REDIRECT:
 655                         orig_frame = *frame;
 656                         xdp->rxq->mem = frame->mem;
 657                         if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
 658                                 frame = &orig_frame;
 659                                 stats->rx_drops++;
 660                                 goto err_xdp;
 661                         }
 662                         stats->xdp_redirect++;
 663                         rcu_read_unlock();
 664                         goto xdp_xmit;
 665                 default:
 666                         bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 667                         fallthrough;
 668                 case XDP_ABORTED:
 669                         trace_xdp_exception(rq->dev, xdp_prog, act);
 670                         fallthrough;
 671                 case XDP_DROP:
 672                         stats->xdp_drops++;
 673                         goto err_xdp;
 674                 }
 675         }
 676         rcu_read_unlock();
 677
 678         return frame;
 679 err_xdp:
 680         rcu_read_unlock();
 681         xdp_return_frame(frame);
 682 xdp_xmit:
 683         return NULL;
 684 }
 685
 686 /* frames array contains VETH_XDP_BATCH at most */
 687 static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames,
 688                                   int n_xdpf, struct veth_xdp_tx_bq *bq,
 689                                   struct veth_stats *stats)
 690 {
 691         void *skbs[VETH_XDP_BATCH];
 692         int i;
 693
 694         if (xdp_alloc_skb_bulk(skbs, n_xdpf,
 695                                GFP_ATOMIC | __GFP_ZERO) < 0) {
 696                 for (i = 0; i < n_xdpf; i++)
 697                         xdp_return_frame(frames[i]);
 698                 stats->rx_drops += n_xdpf;
 699
 700                 return;
 701         }
 702
 703         for (i = 0; i < n_xdpf; i++) {
 704                 struct sk_buff *skb = skbs[i];
 705
 706                 skb = __xdp_build_skb_from_frame(frames[i], skb,
 707                                                  rq->dev);
 708                 if (!skb) {
 709                         xdp_return_frame(frames[i]);
 710                         stats->rx_drops++;
 711                         continue;
 712                 }
 713                 napi_gro_receive(&rq->xdp_napi, skb);
 714         }
 715 }
 716
 717 static void veth_xdp_get(struct xdp_buff *xdp)
 718 {
 719         struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
 720         int i;
 721
 722         get_page(virt_to_page(xdp->data));
 723         if (likely(!xdp_buff_has_frags(xdp)))
 724                 return;
 725
 726         for (i = 0; i < sinfo->nr_frags; i++)
 727                 __skb_frag_ref(&sinfo->frags[i]);
 728 }
 729
 730 static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
 731                                         struct xdp_buff *xdp,
 732                                         struct sk_buff **pskb)
 733 {
 734         struct sk_buff *skb = *pskb;
 735         u32 frame_sz;
 736
 737         if (skb_shared(skb) || skb_head_is_locked(skb) ||
 738             skb_shinfo(skb)->nr_frags ||
 739             skb_headroom(skb) < XDP_PACKET_HEADROOM) {
 740                 u32 size, len, max_head_size, off;
 741                 struct sk_buff *nskb;
 742                 struct page *page;
 743                 int i, head_off;
 744
 745                 /* We need a private copy of the skb and data buffers since
 746                  * the ebpf program can modify it. We segment the original skb
 747                  * into order-0 pages without linearize it.
 748                  *
 749                  * Make sure we have enough space for linear and paged area
 750                  */
 751                 max_head_size = SKB_WITH_OVERHEAD(PAGE_SIZE -
 752                                                   VETH_XDP_HEADROOM);
 753                 if (skb->len > PAGE_SIZE * MAX_SKB_FRAGS + max_head_size)
 754                         goto drop;
 755
 756                 /* Allocate skb head */
 757                 page = page_pool_dev_alloc_pages(rq->page_pool);
 758                 if (!page)
 759                         goto drop;
 760
 761                 nskb = napi_build_skb(page_address(page), PAGE_SIZE);
 762                 if (!nskb) {
 763                         page_pool_put_full_page(rq->page_pool, page, true);
 764                         goto drop;
 765                 }
 766
 767                 skb_reserve(nskb, VETH_XDP_HEADROOM);
 768                 skb_copy_header(nskb, skb);
 769                 skb_mark_for_recycle(nskb);
 770
 771                 size = min_t(u32, skb->len, max_head_size);
 772                 if (skb_copy_bits(skb, 0, nskb->data, size)) {
 773                         consume_skb(nskb);
 774                         goto drop;
 775                 }
 776                 skb_put(nskb, size);
 777
 778                 head_off = skb_headroom(nskb) - skb_headroom(skb);
 779                 skb_headers_offset_update(nskb, head_off);
 780
 781                 /* Allocate paged area of new skb */
 782                 off = size;
 783                 len = skb->len - off;
 784
 785                 for (i = 0; i < MAX_SKB_FRAGS && off < skb->len; i++) {
 786                         page = page_pool_dev_alloc_pages(rq->page_pool);
 787                         if (!page) {
 788                                 consume_skb(nskb);
 789                                 goto drop;
 790                         }
 791
 792                         size = min_t(u32, len, PAGE_SIZE);
 793                         skb_add_rx_frag(nskb, i, page, 0, size, PAGE_SIZE);
 794                         if (skb_copy_bits(skb, off, page_address(page),
 795                                           size)) {
 796                                 consume_skb(nskb);
 797                                 goto drop;
 798                         }
 799
 800                         len -= size;
 801                         off += size;
 802                 }
 803
 804                 consume_skb(skb);
 805                 skb = nskb;
 806         }
 807
 808         /* SKB "head" area always have tailroom for skb_shared_info */
 809         frame_sz = skb_end_pointer(skb) - skb->head;
 810         frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 811         xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq);
 812         xdp_prepare_buff(xdp, skb->head, skb_headroom(skb),
 813                          skb_headlen(skb), true);
 814
 815         if (skb_is_nonlinear(skb)) {
 816                 skb_shinfo(skb)->xdp_frags_size = skb->data_len;
 817                 xdp_buff_set_frags_flag(xdp);
 818         } else {
 819                 xdp_buff_clear_frags_flag(xdp);
 820         }
 821         *pskb = skb;
 822
 823         return 0;
 824 drop:
 825         consume_skb(skb);
 826         *pskb = NULL;
 827
 828         return -ENOMEM;
 829 }
 830
 831 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 832                                         struct sk_buff *skb,
 833                                         struct veth_xdp_tx_bq *bq,
 834                                         struct veth_stats *stats)
 835 {
 836         void *orig_data, *orig_data_end;
 837         struct bpf_prog *xdp_prog;
 838         struct veth_xdp_buff vxbuf;
 839         struct xdp_buff *xdp = &vxbuf.xdp;
 840         u32 act, metalen;
 841         int off;
 842
 843         skb_prepare_for_gro(skb);
 844
 845         rcu_read_lock();
 846         xdp_prog = rcu_dereference(rq->xdp_prog);
 847         if (unlikely(!xdp_prog)) {
 848                 rcu_read_unlock();
 849                 goto out;
 850         }
 851
 852         __skb_push(skb, skb->data - skb_mac_header(skb));
 853         if (veth_convert_skb_to_xdp_buff(rq, xdp, &skb))
 854                 goto drop;
 855         vxbuf.skb = skb;
 856
 857         orig_data = xdp->data;
 858         orig_data_end = xdp->data_end;
 859
 860         act = bpf_prog_run_xdp(xdp_prog, xdp);
 861
 862         switch (act) {
 863         case XDP_PASS:
 864                 break;
 865         case XDP_TX:
 866                 veth_xdp_get(xdp);
 867                 consume_skb(skb);
 868                 xdp->rxq->mem = rq->xdp_mem;
 869                 if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
 870                         trace_xdp_exception(rq->dev, xdp_prog, act);
 871                         stats->rx_drops++;
 872                         goto err_xdp;
 873                 }
 874                 stats->xdp_tx++;
 875                 rcu_read_unlock();
 876                 goto xdp_xmit;
 877         case XDP_REDIRECT:
 878                 veth_xdp_get(xdp);
 879                 consume_skb(skb);
 880                 xdp->rxq->mem = rq->xdp_mem;
 881                 if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
 882                         stats->rx_drops++;
 883                         goto err_xdp;
 884                 }
 885                 stats->xdp_redirect++;
 886                 rcu_read_unlock();
 887                 goto xdp_xmit;
 888         default:
 889                 bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 890                 fallthrough;
 891         case XDP_ABORTED:
 892                 trace_xdp_exception(rq->dev, xdp_prog, act);
 893                 fallthrough;
 894         case XDP_DROP:
 895                 stats->xdp_drops++;
 896                 goto xdp_drop;
 897         }
 898         rcu_read_unlock();
 899
 900         /* check if bpf_xdp_adjust_head was used */
 901         off = orig_data - xdp->data;
 902         if (off > 0)
 903                 __skb_push(skb, off);
 904         else if (off < 0)
 905                 __skb_pull(skb, -off);
 906
 907         skb_reset_mac_header(skb);
 908
 909         /* check if bpf_xdp_adjust_tail was used */
 910         off = xdp->data_end - orig_data_end;
 911         if (off != 0)
 912                 __skb_put(skb, off); /* positive on grow, negative on shrink */
 913
 914         /* XDP frag metadata (e.g. nr_frags) are updated in eBPF helpers
 915          * (e.g. bpf_xdp_adjust_tail), we need to update data_len here.
 916          */
 917         if (xdp_buff_has_frags(xdp))
 918                 skb->data_len = skb_shinfo(skb)->xdp_frags_size;
 919         else
 920                 skb->data_len = 0;
 921
 922         skb->protocol = eth_type_trans(skb, rq->dev);
 923
 924         metalen = xdp->data - xdp->data_meta;
 925         if (metalen)
 926                 skb_metadata_set(skb, metalen);
 927 out:
 928         return skb;
 929 drop:
 930         stats->rx_drops++;
 931 xdp_drop:
 932         rcu_read_unlock();
 933         kfree_skb(skb);
 934         return NULL;
 935 err_xdp:
 936         rcu_read_unlock();
 937         xdp_return_buff(xdp);
 938 xdp_xmit:
 939         return NULL;
 940 }
 941
 942 static int veth_xdp_rcv(struct veth_rq *rq, int budget,
 943                         struct veth_xdp_tx_bq *bq,
 944                         struct veth_stats *stats)
 945 {
 946         int i, done = 0, n_xdpf = 0;
 947         void *xdpf[VETH_XDP_BATCH];
 948
 949         for (i = 0; i < budget; i++) {
 950                 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
 951
 952                 if (!ptr)
 953                         break;
 954
 955                 if (veth_is_xdp_frame(ptr)) {
 956                         /* ndo_xdp_xmit */
 957                         struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
 958
 959                         stats->xdp_bytes += xdp_get_frame_len(frame);
 960                         frame = veth_xdp_rcv_one(rq, frame, bq, stats);
 961                         if (frame) {
 962                                 /* XDP_PASS */
 963                                 xdpf[n_xdpf++] = frame;
 964                                 if (n_xdpf == VETH_XDP_BATCH) {
 965                                         veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf,
 966                                                               bq, stats);
 967                                         n_xdpf = 0;
 968                                 }
 969                         }
 970                 } else {
 971                         /* ndo_start_xmit */
 972                         struct sk_buff *skb = ptr;
 973
 974                         stats->xdp_bytes += skb->len;
 975                         skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
 976                         if (skb) {
 977                                 if (skb_shared(skb) || skb_unclone(skb, GFP_ATOMIC))
 978                                         netif_receive_skb(skb);
 979                                 else
 980                                         napi_gro_receive(&rq->xdp_napi, skb);
 981                         }
 982                 }
 983                 done++;
 984         }
 985
 986         if (n_xdpf)
 987                 veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats);
 988
 989         u64_stats_update_begin(&rq->stats.syncp);
 990         rq->stats.vs.xdp_redirect += stats->xdp_redirect;
 991         rq->stats.vs.xdp_bytes += stats->xdp_bytes;
 992         rq->stats.vs.xdp_drops += stats->xdp_drops;
 993         rq->stats.vs.rx_drops += stats->rx_drops;
 994         rq->stats.vs.xdp_packets += done;
 995         u64_stats_update_end(&rq->stats.syncp);
 996
 997         return done;
 998 }
 999
1000 static int veth_poll(struct napi_struct *napi, int budget)
1001 {
1002         struct veth_rq *rq =
1003                 container_of(napi, struct veth_rq, xdp_napi);
1004         struct veth_stats stats = {};
1005         struct veth_xdp_tx_bq bq;
1006         int done;
1007
1008         bq.count = 0;
1009
1010         xdp_set_return_frame_no_direct();
1011         done = veth_xdp_rcv(rq, budget, &bq, &stats);
1012
1013         if (stats.xdp_redirect > 0)
1014                 xdp_do_flush();
1015
1016         if (done < budget && napi_complete_done(napi, done)) {
1017                 /* Write rx_notify_masked before reading ptr_ring */
1018                 smp_store_mb(rq->rx_notify_masked, false);
1019                 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
1020                         if (napi_schedule_prep(&rq->xdp_napi)) {
1021                                 WRITE_ONCE(rq->rx_notify_masked, true);
1022                                 __napi_schedule(&rq->xdp_napi);
1023                         }
1024                 }
1025         }
1026
1027         if (stats.xdp_tx > 0)
1028                 veth_xdp_flush(rq, &bq);
1029         xdp_clear_return_frame_no_direct();
1030
1031         return done;
1032 }
1033
1034 static int veth_create_page_pool(struct veth_rq *rq)
1035 {
1036         struct page_pool_params pp_params = {
1037                 .order = 0,
1038                 .pool_size = VETH_RING_SIZE,
1039                 .nid = NUMA_NO_NODE,
1040                 .dev = &rq->dev->dev,
1041         };
1042
1043         rq->page_pool = page_pool_create(&pp_params);
1044         if (IS_ERR(rq->page_pool)) {
1045                 int err = PTR_ERR(rq->page_pool);
1046
1047                 rq->page_pool = NULL;
1048                 return err;
1049         }
1050
1051         return 0;
1052 }
1053
1054 static int __veth_napi_enable_range(struct net_device *dev, int start, int end)
1055 {
1056         struct veth_priv *priv = netdev_priv(dev);
1057         int err, i;
1058
1059         for (i = start; i < end; i++) {
1060                 err = veth_create_page_pool(&priv->rq[i]);
1061                 if (err)
1062                         goto err_page_pool;
1063         }
1064
1065         for (i = start; i < end; i++) {
1066                 struct veth_rq *rq = &priv->rq[i];
1067
1068                 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
1069                 if (err)
1070                         goto err_xdp_ring;
1071         }
1072
1073         for (i = start; i < end; i++) {
1074                 struct veth_rq *rq = &priv->rq[i];
1075
1076                 napi_enable(&rq->xdp_napi);
1077                 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1078         }
1079
1080         return 0;
1081
1082 err_xdp_ring:
1083         for (i--; i >= start; i--)
1084                 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
1085         i = end;
1086 err_page_pool:
1087         for (i--; i >= start; i--) {
1088                 page_pool_destroy(priv->rq[i].page_pool);
1089                 priv->rq[i].page_pool = NULL;
1090         }
1091
1092         return err;
1093 }
1094
1095 static int __veth_napi_enable(struct net_device *dev)
1096 {
1097         return __veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1098 }
1099
1100 static void veth_napi_del_range(struct net_device *dev, int start, int end)
1101 {
1102         struct veth_priv *priv = netdev_priv(dev);
1103         int i;
1104
1105         for (i = start; i < end; i++) {
1106                 struct veth_rq *rq = &priv->rq[i];
1107
1108                 rcu_assign_pointer(priv->rq[i].napi, NULL);
1109                 napi_disable(&rq->xdp_napi);
1110                 __netif_napi_del(&rq->xdp_napi);
1111         }
1112         synchronize_net();
1113
1114         for (i = start; i < end; i++) {
1115                 struct veth_rq *rq = &priv->rq[i];
1116
1117                 rq->rx_notify_masked = false;
1118                 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
1119         }
1120
1121         for (i = start; i < end; i++) {
1122                 page_pool_destroy(priv->rq[i].page_pool);
1123                 priv->rq[i].page_pool = NULL;
1124         }
1125 }
1126
1127 static void veth_napi_del(struct net_device *dev)
1128 {
1129         veth_napi_del_range(dev, 0, dev->real_num_rx_queues);
1130 }
1131
1132 static bool veth_gro_requested(const struct net_device *dev)
1133 {
1134         return !!(dev->wanted_features & NETIF_F_GRO);
1135 }
1136
1137 static int veth_enable_xdp_range(struct net_device *dev, int start, int end,
1138                                  bool napi_already_on)
1139 {
1140         struct veth_priv *priv = netdev_priv(dev);
1141         int err, i;
1142
1143         for (i = start; i < end; i++) {
1144                 struct veth_rq *rq = &priv->rq[i];
1145
1146                 if (!napi_already_on)
1147                         netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1148                 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id);
1149                 if (err < 0)
1150                         goto err_rxq_reg;
1151
1152                 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
1153                                                  MEM_TYPE_PAGE_SHARED,
1154                                                  NULL);
1155                 if (err < 0)
1156                         goto err_reg_mem;
1157
1158                 /* Save original mem info as it can be overwritten */
1159                 rq->xdp_mem = rq->xdp_rxq.mem;
1160         }
1161         return 0;
1162
1163 err_reg_mem:
1164         xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
1165 err_rxq_reg:
1166         for (i--; i >= start; i--) {
1167                 struct veth_rq *rq = &priv->rq[i];
1168
1169                 xdp_rxq_info_unreg(&rq->xdp_rxq);
1170                 if (!napi_already_on)
1171                         netif_napi_del(&rq->xdp_napi);
1172         }
1173
1174         return err;
1175 }
1176
1177 static void veth_disable_xdp_range(struct net_device *dev, int start, int end,
1178                                    bool delete_napi)
1179 {
1180         struct veth_priv *priv = netdev_priv(dev);
1181         int i;
1182
1183         for (i = start; i < end; i++) {
1184                 struct veth_rq *rq = &priv->rq[i];
1185
1186                 rq->xdp_rxq.mem = rq->xdp_mem;
1187                 xdp_rxq_info_unreg(&rq->xdp_rxq);
1188
1189                 if (delete_napi)
1190                         netif_napi_del(&rq->xdp_napi);
1191         }
1192 }
1193
1194 static int veth_enable_xdp(struct net_device *dev)
1195 {
1196         bool napi_already_on = veth_gro_requested(dev) && (dev->flags & IFF_UP);
1197         struct veth_priv *priv = netdev_priv(dev);
1198         int err, i;
1199
1200         if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
1201                 err = veth_enable_xdp_range(dev, 0, dev->real_num_rx_queues, napi_already_on);
1202                 if (err)
1203                         return err;
1204
1205                 if (!napi_already_on) {
1206                         err = __veth_napi_enable(dev);
1207                         if (err) {
1208                                 veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, true);
1209                                 return err;
1210                         }
1211
1212                         if (!veth_gro_requested(dev)) {
1213                                 /* user-space did not require GRO, but adding XDP
1214                                  * is supposed to get GRO working
1215                                  */
1216                                 dev->features |= NETIF_F_GRO;
1217                                 netdev_features_change(dev);
1218                         }
1219                 }
1220         }
1221
1222         for (i = 0; i < dev->real_num_rx_queues; i++) {
1223                 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
1224                 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1225         }
1226
1227         return 0;
1228 }
1229
1230 static void veth_disable_xdp(struct net_device *dev)
1231 {
1232         struct veth_priv *priv = netdev_priv(dev);
1233         int i;
1234
1235         for (i = 0; i < dev->real_num_rx_queues; i++)
1236                 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
1237
1238         if (!netif_running(dev) || !veth_gro_requested(dev)) {
1239                 veth_napi_del(dev);
1240
1241                 /* if user-space did not require GRO, since adding XDP
1242                  * enabled it, clear it now
1243                  */
1244                 if (!veth_gro_requested(dev) && netif_running(dev)) {
1245                         dev->features &= ~NETIF_F_GRO;
1246                         netdev_features_change(dev);
1247                 }
1248         }
1249
1250         veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, false);
1251 }
1252
1253 static int veth_napi_enable_range(struct net_device *dev, int start, int end)
1254 {
1255         struct veth_priv *priv = netdev_priv(dev);
1256         int err, i;
1257
1258         for (i = start; i < end; i++) {
1259                 struct veth_rq *rq = &priv->rq[i];
1260
1261                 netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1262         }
1263
1264         err = __veth_napi_enable_range(dev, start, end);
1265         if (err) {
1266                 for (i = start; i < end; i++) {
1267                         struct veth_rq *rq = &priv->rq[i];
1268
1269                         netif_napi_del(&rq->xdp_napi);
1270                 }
1271                 return err;
1272         }
1273         return err;
1274 }
1275
1276 static int veth_napi_enable(struct net_device *dev)
1277 {
1278         return veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1279 }
1280
1281 static void veth_disable_range_safe(struct net_device *dev, int start, int end)
1282 {
1283         struct veth_priv *priv = netdev_priv(dev);
1284
1285         if (start >= end)
1286                 return;
1287
1288         if (priv->_xdp_prog) {
1289                 veth_napi_del_range(dev, start, end);
1290                 veth_disable_xdp_range(dev, start, end, false);
1291         } else if (veth_gro_requested(dev)) {
1292                 veth_napi_del_range(dev, start, end);
1293         }
1294 }
1295
1296 static int veth_enable_range_safe(struct net_device *dev, int start, int end)
1297 {
1298         struct veth_priv *priv = netdev_priv(dev);
1299         int err;
1300
1301         if (start >= end)
1302                 return 0;
1303
1304         if (priv->_xdp_prog) {
1305                 /* these channels are freshly initialized, napi is not on there even
1306                  * when GRO is requeste
1307                  */
1308                 err = veth_enable_xdp_range(dev, start, end, false);
1309                 if (err)
1310                         return err;
1311
1312                 err = __veth_napi_enable_range(dev, start, end);
1313                 if (err) {
1314                         /* on error always delete the newly added napis */
1315                         veth_disable_xdp_range(dev, start, end, true);
1316                         return err;
1317                 }
1318         } else if (veth_gro_requested(dev)) {
1319                 return veth_napi_enable_range(dev, start, end);
1320         }
1321         return 0;
1322 }
1323
1324 static void veth_set_xdp_features(struct net_device *dev)
1325 {
1326         struct veth_priv *priv = netdev_priv(dev);
1327         struct net_device *peer;
1328
1329         peer = rtnl_dereference(priv->peer);
1330         if (peer && peer->real_num_tx_queues <= dev->real_num_rx_queues) {
1331                 struct veth_priv *priv_peer = netdev_priv(peer);
1332                 xdp_features_t val = NETDEV_XDP_ACT_BASIC |
1333                                      NETDEV_XDP_ACT_REDIRECT |
1334                                      NETDEV_XDP_ACT_RX_SG;
1335
1336                 if (priv_peer->_xdp_prog || veth_gro_requested(peer))
1337                         val |= NETDEV_XDP_ACT_NDO_XMIT |
1338                                NETDEV_XDP_ACT_NDO_XMIT_SG;
1339                 xdp_set_features_flag(dev, val);
1340         } else {
1341                 xdp_clear_features_flag(dev);
1342         }
1343 }
1344
1345 static int veth_set_channels(struct net_device *dev,
1346                              struct ethtool_channels *ch)
1347 {
1348         struct veth_priv *priv = netdev_priv(dev);
1349         unsigned int old_rx_count, new_rx_count;
1350         struct veth_priv *peer_priv;
1351         struct net_device *peer;
1352         int err;
1353
1354         /* sanity check. Upper bounds are already enforced by the caller */
1355         if (!ch->rx_count || !ch->tx_count)
1356                 return -EINVAL;
1357
1358         /* avoid braking XDP, if that is enabled */
1359         peer = rtnl_dereference(priv->peer);
1360         peer_priv = peer ? netdev_priv(peer) : NULL;
1361         if (priv->_xdp_prog && peer && ch->rx_count < peer->real_num_tx_queues)
1362                 return -EINVAL;
1363
1364         if (peer && peer_priv && peer_priv->_xdp_prog && ch->tx_count > peer->real_num_rx_queues)
1365                 return -EINVAL;
1366
1367         old_rx_count = dev->real_num_rx_queues;
1368         new_rx_count = ch->rx_count;
1369         if (netif_running(dev)) {
1370                 /* turn device off */
1371                 netif_carrier_off(dev);
1372                 if (peer)
1373                         netif_carrier_off(peer);
1374
1375                 /* try to allocate new resurces, as needed*/
1376                 err = veth_enable_range_safe(dev, old_rx_count, new_rx_count);
1377                 if (err)
1378                         goto out;
1379         }
1380
1381         err = netif_set_real_num_rx_queues(dev, ch->rx_count);
1382         if (err)
1383                 goto revert;
1384
1385         err = netif_set_real_num_tx_queues(dev, ch->tx_count);
1386         if (err) {
1387                 int err2 = netif_set_real_num_rx_queues(dev, old_rx_count);
1388
1389                 /* this error condition could happen only if rx and tx change
1390                  * in opposite directions (e.g. tx nr raises, rx nr decreases)
1391                  * and we can't do anything to fully restore the original
1392                  * status
1393                  */
1394                 if (err2)
1395                         pr_warn("Can't restore rx queues config %d -> %d %d",
1396                                 new_rx_count, old_rx_count, err2);
1397                 else
1398                         goto revert;
1399         }
1400
1401 out:
1402         if (netif_running(dev)) {
1403                 /* note that we need to swap the arguments WRT the enable part
1404                  * to identify the range we have to disable
1405                  */
1406                 veth_disable_range_safe(dev, new_rx_count, old_rx_count);
1407                 netif_carrier_on(dev);
1408                 if (peer)
1409                         netif_carrier_on(peer);
1410         }
1411
1412         /* update XDP supported features */
1413         veth_set_xdp_features(dev);
1414         if (peer)
1415                 veth_set_xdp_features(peer);
1416
1417         return err;
1418
1419 revert:
1420         new_rx_count = old_rx_count;
1421         old_rx_count = ch->rx_count;
1422         goto out;
1423 }
1424
1425 static int veth_open(struct net_device *dev)
1426 {
1427         struct veth_priv *priv = netdev_priv(dev);
1428         struct net_device *peer = rtnl_dereference(priv->peer);
1429         int err;
1430
1431         if (!peer)
1432                 return -ENOTCONN;
1433
1434         if (priv->_xdp_prog) {
1435                 err = veth_enable_xdp(dev);
1436                 if (err)
1437                         return err;
1438         } else if (veth_gro_requested(dev)) {
1439                 err = veth_napi_enable(dev);
1440                 if (err)
1441                         return err;
1442         }
1443
1444         if (peer->flags & IFF_UP) {
1445                 netif_carrier_on(dev);
1446                 netif_carrier_on(peer);
1447         }
1448
1449         veth_set_xdp_features(dev);
1450
1451         return 0;
1452 }
1453
1454 static int veth_close(struct net_device *dev)
1455 {
1456         struct veth_priv *priv = netdev_priv(dev);
1457         struct net_device *peer = rtnl_dereference(priv->peer);
1458
1459         netif_carrier_off(dev);
1460         if (peer)
1461                 netif_carrier_off(peer);
1462
1463         if (priv->_xdp_prog)
1464                 veth_disable_xdp(dev);
1465         else if (veth_gro_requested(dev))
1466                 veth_napi_del(dev);
1467
1468         return 0;
1469 }
1470
1471 static int is_valid_veth_mtu(int mtu)
1472 {
1473         return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1474 }
1475
1476 static int veth_alloc_queues(struct net_device *dev)
1477 {
1478         struct veth_priv *priv = netdev_priv(dev);
1479         int i;
1480
1481         priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL_ACCOUNT);
1482         if (!priv->rq)
1483                 return -ENOMEM;
1484
1485         for (i = 0; i < dev->num_rx_queues; i++) {
1486                 priv->rq[i].dev = dev;
1487                 u64_stats_init(&priv->rq[i].stats.syncp);
1488         }
1489
1490         return 0;
1491 }
1492
1493 static void veth_free_queues(struct net_device *dev)
1494 {
1495         struct veth_priv *priv = netdev_priv(dev);
1496
1497         kfree(priv->rq);
1498 }
1499
1500 static int veth_dev_init(struct net_device *dev)
1501 {
1502         int err;
1503
1504         dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
1505         if (!dev->lstats)
1506                 return -ENOMEM;
1507
1508         err = veth_alloc_queues(dev);
1509         if (err) {
1510                 free_percpu(dev->lstats);
1511                 return err;
1512         }
1513
1514         return 0;
1515 }
1516
1517 static void veth_dev_free(struct net_device *dev)
1518 {
1519         veth_free_queues(dev);
1520         free_percpu(dev->lstats);
1521 }
1522
1523 #ifdef CONFIG_NET_POLL_CONTROLLER
1524 static void veth_poll_controller(struct net_device *dev)
1525 {
1526         /* veth only receives frames when its peer sends one
1527          * Since it has nothing to do with disabling irqs, we are guaranteed
1528          * never to have pending data when we poll for it so
1529          * there is nothing to do here.
1530          *
1531          * We need this though so netpoll recognizes us as an interface that
1532          * supports polling, which enables bridge devices in virt setups to
1533          * still use netconsole
1534          */
1535 }
1536 #endif  /* CONFIG_NET_POLL_CONTROLLER */
1537
1538 static int veth_get_iflink(const struct net_device *dev)
1539 {
1540         struct veth_priv *priv = netdev_priv(dev);
1541         struct net_device *peer;
1542         int iflink;
1543
1544         rcu_read_lock();
1545         peer = rcu_dereference(priv->peer);
1546         iflink = peer ? peer->ifindex : 0;
1547         rcu_read_unlock();
1548
1549         return iflink;
1550 }
1551
1552 static netdev_features_t veth_fix_features(struct net_device *dev,
1553                                            netdev_features_t features)
1554 {
1555         struct veth_priv *priv = netdev_priv(dev);
1556         struct net_device *peer;
1557
1558         peer = rtnl_dereference(priv->peer);
1559         if (peer) {
1560                 struct veth_priv *peer_priv = netdev_priv(peer);
1561
1562                 if (peer_priv->_xdp_prog)
1563                         features &= ~NETIF_F_GSO_SOFTWARE;
1564         }
1565         if (priv->_xdp_prog)
1566                 features |= NETIF_F_GRO;
1567
1568         return features;
1569 }
1570
1571 static int veth_set_features(struct net_device *dev,
1572                              netdev_features_t features)
1573 {
1574         netdev_features_t changed = features ^ dev->features;
1575         struct veth_priv *priv = netdev_priv(dev);
1576         struct net_device *peer;
1577         int err;
1578
1579         if (!(changed & NETIF_F_GRO) || !(dev->flags & IFF_UP) || priv->_xdp_prog)
1580                 return 0;
1581
1582         peer = rtnl_dereference(priv->peer);
1583         if (features & NETIF_F_GRO) {
1584                 err = veth_napi_enable(dev);
1585                 if (err)
1586                         return err;
1587
1588                 if (peer)
1589                         xdp_features_set_redirect_target(peer, true);
1590         } else {
1591                 if (peer)
1592                         xdp_features_clear_redirect_target(peer);
1593                 veth_napi_del(dev);
1594         }
1595         return 0;
1596 }
1597
1598 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1599 {
1600         struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1601         struct net_device *peer;
1602
1603         if (new_hr < 0)
1604                 new_hr = 0;
1605
1606         rcu_read_lock();
1607         peer = rcu_dereference(priv->peer);
1608         if (unlikely(!peer))
1609                 goto out;
1610
1611         peer_priv = netdev_priv(peer);
1612         priv->requested_headroom = new_hr;
1613         new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1614         dev->needed_headroom = new_hr;
1615         peer->needed_headroom = new_hr;
1616
1617 out:
1618         rcu_read_unlock();
1619 }
1620
1621 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1622                         struct netlink_ext_ack *extack)
1623 {
1624         struct veth_priv *priv = netdev_priv(dev);
1625         struct bpf_prog *old_prog;
1626         struct net_device *peer;
1627         unsigned int max_mtu;
1628         int err;
1629
1630         old_prog = priv->_xdp_prog;
1631         priv->_xdp_prog = prog;
1632         peer = rtnl_dereference(priv->peer);
1633
1634         if (prog) {
1635                 if (!peer) {
1636                         NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1637                         err = -ENOTCONN;
1638                         goto err;
1639                 }
1640
1641                 max_mtu = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) -
1642                           peer->hard_header_len;
1643                 /* Allow increasing the max_mtu if the program supports
1644                  * XDP fragments.
1645                  */
1646                 if (prog->aux->xdp_has_frags)
1647                         max_mtu += PAGE_SIZE * MAX_SKB_FRAGS;
1648
1649                 if (peer->mtu > max_mtu) {
1650                         NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1651                         err = -ERANGE;
1652                         goto err;
1653                 }
1654
1655                 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1656                         NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1657                         err = -ENOSPC;
1658                         goto err;
1659                 }
1660
1661                 if (dev->flags & IFF_UP) {
1662                         err = veth_enable_xdp(dev);
1663                         if (err) {
1664                                 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1665                                 goto err;
1666                         }
1667                 }
1668
1669                 if (!old_prog) {
1670                         peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1671                         peer->max_mtu = max_mtu;
1672                 }
1673
1674                 xdp_features_set_redirect_target(peer, true);
1675         }
1676
1677         if (old_prog) {
1678                 if (!prog) {
1679                         if (peer && !veth_gro_requested(dev))
1680                                 xdp_features_clear_redirect_target(peer);
1681
1682                         if (dev->flags & IFF_UP)
1683                                 veth_disable_xdp(dev);
1684
1685                         if (peer) {
1686                                 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1687                                 peer->max_mtu = ETH_MAX_MTU;
1688                         }
1689                 }
1690                 bpf_prog_put(old_prog);
1691         }
1692
1693         if ((!!old_prog ^ !!prog) && peer)
1694                 netdev_update_features(peer);
1695
1696         return 0;
1697 err:
1698         priv->_xdp_prog = old_prog;
1699
1700         return err;
1701 }
1702
1703 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1704 {
1705         switch (xdp->command) {
1706         case XDP_SETUP_PROG:
1707                 return veth_xdp_set(dev, xdp->prog, xdp->extack);
1708         default:
1709                 return -EINVAL;
1710         }
1711 }
1712
1713 static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
1714 {
1715         struct veth_xdp_buff *_ctx = (void *)ctx;
1716
1717         if (!_ctx->skb)
1718                 return -ENODATA;
1719
1720         *timestamp = skb_hwtstamps(_ctx->skb)->hwtstamp;
1721         return 0;
1722 }
1723
1724 static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
1725                             enum xdp_rss_hash_type *rss_type)
1726 {
1727         struct veth_xdp_buff *_ctx = (void *)ctx;
1728         struct sk_buff *skb = _ctx->skb;
1729
1730         if (!skb)
1731                 return -ENODATA;
1732
1733         *hash = skb_get_hash(skb);
1734         *rss_type = skb->l4_hash ? XDP_RSS_TYPE_L4_ANY : XDP_RSS_TYPE_NONE;
1735
1736         return 0;
1737 }
1738
1739 static const struct net_device_ops veth_netdev_ops = {
1740         .ndo_init            = veth_dev_init,
1741         .ndo_open            = veth_open,
1742         .ndo_stop            = veth_close,
1743         .ndo_start_xmit      = veth_xmit,
1744         .ndo_get_stats64     = veth_get_stats64,
1745         .ndo_set_rx_mode     = veth_set_multicast_list,
1746         .ndo_set_mac_address = eth_mac_addr,
1747 #ifdef CONFIG_NET_POLL_CONTROLLER
1748         .ndo_poll_controller    = veth_poll_controller,
1749 #endif
1750         .ndo_get_iflink         = veth_get_iflink,
1751         .ndo_fix_features       = veth_fix_features,
1752         .ndo_set_features       = veth_set_features,
1753         .ndo_features_check     = passthru_features_check,
1754         .ndo_set_rx_headroom    = veth_set_rx_headroom,
1755         .ndo_bpf                = veth_xdp,
1756         .ndo_xdp_xmit           = veth_ndo_xdp_xmit,
1757         .ndo_get_peer_dev       = veth_peer_dev,
1758 };
1759
1760 static const struct xdp_metadata_ops veth_xdp_metadata_ops = {
1761         .xmo_rx_timestamp               = veth_xdp_rx_timestamp,
1762         .xmo_rx_hash                    = veth_xdp_rx_hash,
1763 };
1764
1765 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1766                        NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1767                        NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1768                        NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1769                        NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1770
1771 static void veth_setup(struct net_device *dev)
1772 {
1773         ether_setup(dev);
1774
1775         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1776         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1777         dev->priv_flags |= IFF_NO_QUEUE;
1778         dev->priv_flags |= IFF_PHONY_HEADROOM;
1779
1780         dev->netdev_ops = &veth_netdev_ops;
1781         dev->xdp_metadata_ops = &veth_xdp_metadata_ops;
1782         dev->ethtool_ops = &veth_ethtool_ops;
1783         dev->features |= NETIF_F_LLTX;
1784         dev->features |= VETH_FEATURES;
1785         dev->vlan_features = dev->features &
1786                              ~(NETIF_F_HW_VLAN_CTAG_TX |
1787                                NETIF_F_HW_VLAN_STAG_TX |
1788                                NETIF_F_HW_VLAN_CTAG_RX |
1789                                NETIF_F_HW_VLAN_STAG_RX);
1790         dev->needs_free_netdev = true;
1791         dev->priv_destructor = veth_dev_free;
1792         dev->max_mtu = ETH_MAX_MTU;
1793
1794         dev->hw_features = VETH_FEATURES;
1795         dev->hw_enc_features = VETH_FEATURES;
1796         dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1797         netif_set_tso_max_size(dev, GSO_MAX_SIZE);
1798 }
1799
1800 /*
1801  * netlink interface
1802  */
1803
1804 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1805                          struct netlink_ext_ack *extack)
1806 {
1807         if (tb[IFLA_ADDRESS]) {
1808                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1809                         return -EINVAL;
1810                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1811                         return -EADDRNOTAVAIL;
1812         }
1813         if (tb[IFLA_MTU]) {
1814                 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1815                         return -EINVAL;
1816         }
1817         return 0;
1818 }
1819
1820 static struct rtnl_link_ops veth_link_ops;
1821
1822 static void veth_disable_gro(struct net_device *dev)
1823 {
1824         dev->features &= ~NETIF_F_GRO;
1825         dev->wanted_features &= ~NETIF_F_GRO;
1826         netdev_update_features(dev);
1827 }
1828
1829 static int veth_init_queues(struct net_device *dev, struct nlattr *tb[])
1830 {
1831         int err;
1832
1833         if (!tb[IFLA_NUM_TX_QUEUES] && dev->num_tx_queues > 1) {
1834                 err = netif_set_real_num_tx_queues(dev, 1);
1835                 if (err)
1836                         return err;
1837         }
1838         if (!tb[IFLA_NUM_RX_QUEUES] && dev->num_rx_queues > 1) {
1839                 err = netif_set_real_num_rx_queues(dev, 1);
1840                 if (err)
1841                         return err;
1842         }
1843         return 0;
1844 }
1845
1846 static int veth_newlink(struct net *src_net, struct net_device *dev,
1847                         struct nlattr *tb[], struct nlattr *data[],
1848                         struct netlink_ext_ack *extack)
1849 {
1850         int err;
1851         struct net_device *peer;
1852         struct veth_priv *priv;
1853         char ifname[IFNAMSIZ];
1854         struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1855         unsigned char name_assign_type;
1856         struct ifinfomsg *ifmp;
1857         struct net *net;
1858
1859         /*
1860          * create and register peer first
1861          */
1862         if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1863                 struct nlattr *nla_peer;
1864
1865                 nla_peer = data[VETH_INFO_PEER];
1866                 ifmp = nla_data(nla_peer);
1867                 err = rtnl_nla_parse_ifinfomsg(peer_tb, nla_peer, extack);
1868                 if (err < 0)
1869                         return err;
1870
1871                 err = veth_validate(peer_tb, NULL, extack);
1872                 if (err < 0)
1873                         return err;
1874
1875                 tbp = peer_tb;
1876         } else {
1877                 ifmp = NULL;
1878                 tbp = tb;
1879         }
1880
1881         if (ifmp && tbp[IFLA_IFNAME]) {
1882                 nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1883                 name_assign_type = NET_NAME_USER;
1884         } else {
1885                 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1886                 name_assign_type = NET_NAME_ENUM;
1887         }
1888
1889         net = rtnl_link_get_net(src_net, tbp);
1890         if (IS_ERR(net))
1891                 return PTR_ERR(net);
1892
1893         peer = rtnl_create_link(net, ifname, name_assign_type,
1894                                 &veth_link_ops, tbp, extack);
1895         if (IS_ERR(peer)) {
1896                 put_net(net);
1897                 return PTR_ERR(peer);
1898         }
1899
1900         if (!ifmp || !tbp[IFLA_ADDRESS])
1901                 eth_hw_addr_random(peer);
1902
1903         if (ifmp && (dev->ifindex != 0))
1904                 peer->ifindex = ifmp->ifi_index;
1905
1906         netif_inherit_tso_max(peer, dev);
1907
1908         err = register_netdevice(peer);
1909         put_net(net);
1910         net = NULL;
1911         if (err < 0)
1912                 goto err_register_peer;
1913
1914         /* keep GRO disabled by default to be consistent with the established
1915          * veth behavior
1916          */
1917         veth_disable_gro(peer);
1918         netif_carrier_off(peer);
1919
1920         err = rtnl_configure_link(peer, ifmp, 0, NULL);
1921         if (err < 0)
1922                 goto err_configure_peer;
1923
1924         /*
1925          * register dev last
1926          *
1927          * note, that since we've registered new device the dev's name
1928          * should be re-allocated
1929          */
1930
1931         if (tb[IFLA_ADDRESS] == NULL)
1932                 eth_hw_addr_random(dev);
1933
1934         if (tb[IFLA_IFNAME])
1935                 nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1936         else
1937                 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1938
1939         err = register_netdevice(dev);
1940         if (err < 0)
1941                 goto err_register_dev;
1942
1943         netif_carrier_off(dev);
1944
1945         /*
1946          * tie the deviced together
1947          */
1948
1949         priv = netdev_priv(dev);
1950         rcu_assign_pointer(priv->peer, peer);
1951         err = veth_init_queues(dev, tb);
1952         if (err)
1953                 goto err_queues;
1954
1955         priv = netdev_priv(peer);
1956         rcu_assign_pointer(priv->peer, dev);
1957         err = veth_init_queues(peer, tb);
1958         if (err)
1959                 goto err_queues;
1960
1961         veth_disable_gro(dev);
1962         /* update XDP supported features */
1963         veth_set_xdp_features(dev);
1964         veth_set_xdp_features(peer);
1965
1966         return 0;
1967
1968 err_queues:
1969         unregister_netdevice(dev);
1970 err_register_dev:
1971         /* nothing to do */
1972 err_configure_peer:
1973         unregister_netdevice(peer);
1974         return err;
1975
1976 err_register_peer:
1977         free_netdev(peer);
1978         return err;
1979 }
1980
1981 static void veth_dellink(struct net_device *dev, struct list_head *head)
1982 {
1983         struct veth_priv *priv;
1984         struct net_device *peer;
1985
1986         priv = netdev_priv(dev);
1987         peer = rtnl_dereference(priv->peer);
1988
1989         /* Note : dellink() is called from default_device_exit_batch(),
1990          * before a rcu_synchronize() point. The devices are guaranteed
1991          * not being freed before one RCU grace period.
1992          */
1993         RCU_INIT_POINTER(priv->peer, NULL);
1994         unregister_netdevice_queue(dev, head);
1995
1996         if (peer) {
1997                 priv = netdev_priv(peer);
1998                 RCU_INIT_POINTER(priv->peer, NULL);
1999                 unregister_netdevice_queue(peer, head);
2000         }
2001 }
2002
2003 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
2004         [VETH_INFO_PEER]        = { .len = sizeof(struct ifinfomsg) },
2005 };
2006
2007 static struct net *veth_get_link_net(const struct net_device *dev)
2008 {
2009         struct veth_priv *priv = netdev_priv(dev);
2010         struct net_device *peer = rtnl_dereference(priv->peer);
2011
2012         return peer ? dev_net(peer) : dev_net(dev);
2013 }
2014
2015 static unsigned int veth_get_num_queues(void)
2016 {
2017         /* enforce the same queue limit as rtnl_create_link */
2018         int queues = num_possible_cpus();
2019
2020         if (queues > 4096)
2021                 queues = 4096;
2022         return queues;
2023 }
2024
2025 static struct rtnl_link_ops veth_link_ops = {
2026         .kind           = DRV_NAME,
2027         .priv_size      = sizeof(struct veth_priv),
2028         .setup          = veth_setup,
2029         .validate       = veth_validate,
2030         .newlink        = veth_newlink,
2031         .dellink        = veth_dellink,
2032         .policy         = veth_policy,
2033         .maxtype        = VETH_INFO_MAX,
2034         .get_link_net   = veth_get_link_net,
2035         .get_num_tx_queues      = veth_get_num_queues,
2036         .get_num_rx_queues      = veth_get_num_queues,
2037 };
2038
2039 /*
2040  * init/fini
2041  */
2042
2043 static __init int veth_init(void)
2044 {
2045         return rtnl_link_register(&veth_link_ops);
2046 }
2047
2048 static __exit void veth_exit(void)
2049 {
2050         rtnl_link_unregister(&veth_link_ops);
2051 }
2052
2053 module_init(veth_init);
2054 module_exit(veth_exit);
2055
2056 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
2057 MODULE_LICENSE("GPL v2");
2058 MODULE_ALIAS_RTNL_LINK(DRV_NAME);