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