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 struct xdp_frame *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(struct xdp_frame *xdp) 243 { 244 return (void *)((unsigned long)xdp | 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 skb = build_skb(head, buflen); 409 if (!skb) 410 return NULL; 411 412 skb_reserve(skb, headroom); 413 skb_put(skb, len); 414 415 return skb; 416 } 417 418 static int veth_select_rxq(struct net_device *dev) 419 { 420 return smp_processor_id() % dev->real_num_rx_queues; 421 } 422 423 static struct net_device *veth_peer_dev(struct net_device *dev) 424 { 425 struct veth_priv *priv = netdev_priv(dev); 426 427 /* Callers must be under RCU read side. */ 428 return rcu_dereference(priv->peer); 429 } 430 431 static int veth_xdp_xmit(struct net_device *dev, int n, 432 struct xdp_frame **frames, 433 u32 flags, bool ndo_xmit) 434 { 435 struct veth_priv *rcv_priv, *priv = netdev_priv(dev); 436 int i, ret = -ENXIO, drops = 0; 437 struct net_device *rcv; 438 unsigned int max_len; 439 struct veth_rq *rq; 440 441 if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) 442 return -EINVAL; 443 444 rcu_read_lock(); 445 rcv = rcu_dereference(priv->peer); 446 if (unlikely(!rcv)) 447 goto out; 448 449 rcv_priv = netdev_priv(rcv); 450 rq = &rcv_priv->rq[veth_select_rxq(rcv)]; 451 /* Non-NULL xdp_prog ensures that xdp_ring is initialized on receive 452 * side. This means an XDP program is loaded on the peer and the peer 453 * device is up. 454 */ 455 if (!rcu_access_pointer(rq->xdp_prog)) 456 goto out; 457 458 max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN; 459 460 spin_lock(&rq->xdp_ring.producer_lock); 461 for (i = 0; i < n; i++) { 462 struct xdp_frame *frame = frames[i]; 463 void *ptr = veth_xdp_to_ptr(frame); 464 465 if (unlikely(frame->len > max_len || 466 __ptr_ring_produce(&rq->xdp_ring, ptr))) { 467 xdp_return_frame_rx_napi(frame); 468 drops++; 469 } 470 } 471 spin_unlock(&rq->xdp_ring.producer_lock); 472 473 if (flags & XDP_XMIT_FLUSH) 474 __veth_xdp_flush(rq); 475 476 ret = n - drops; 477 if (ndo_xmit) { 478 u64_stats_update_begin(&rq->stats.syncp); 479 rq->stats.vs.peer_tq_xdp_xmit += n - drops; 480 rq->stats.vs.peer_tq_xdp_xmit_err += drops; 481 u64_stats_update_end(&rq->stats.syncp); 482 } 483 484 out: 485 rcu_read_unlock(); 486 487 return ret; 488 } 489 490 static int veth_ndo_xdp_xmit(struct net_device *dev, int n, 491 struct xdp_frame **frames, u32 flags) 492 { 493 int err; 494 495 err = veth_xdp_xmit(dev, n, frames, flags, true); 496 if (err < 0) { 497 struct veth_priv *priv = netdev_priv(dev); 498 499 atomic64_add(n, &priv->dropped); 500 } 501 502 return err; 503 } 504 505 static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq) 506 { 507 int sent, i, err = 0; 508 509 sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false); 510 if (sent < 0) { 511 err = sent; 512 sent = 0; 513 for (i = 0; i < bq->count; i++) 514 xdp_return_frame(bq->q[i]); 515 } 516 trace_xdp_bulk_tx(rq->dev, sent, bq->count - sent, err); 517 518 u64_stats_update_begin(&rq->stats.syncp); 519 rq->stats.vs.xdp_tx += sent; 520 rq->stats.vs.xdp_tx_err += bq->count - sent; 521 u64_stats_update_end(&rq->stats.syncp); 522 523 bq->count = 0; 524 } 525 526 static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq) 527 { 528 struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev); 529 struct net_device *rcv; 530 struct veth_rq *rcv_rq; 531 532 rcu_read_lock(); 533 veth_xdp_flush_bq(rq, bq); 534 rcv = rcu_dereference(priv->peer); 535 if (unlikely(!rcv)) 536 goto out; 537 538 rcv_priv = netdev_priv(rcv); 539 rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)]; 540 /* xdp_ring is initialized on receive side? */ 541 if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog))) 542 goto out; 543 544 __veth_xdp_flush(rcv_rq); 545 out: 546 rcu_read_unlock(); 547 } 548 549 static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp, 550 struct veth_xdp_tx_bq *bq) 551 { 552 struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp); 553 554 if (unlikely(!frame)) 555 return -EOVERFLOW; 556 557 if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE)) 558 veth_xdp_flush_bq(rq, bq); 559 560 bq->q[bq->count++] = frame; 561 562 return 0; 563 } 564 565 static struct sk_buff *veth_xdp_rcv_one(struct veth_rq *rq, 566 struct xdp_frame *frame, 567 struct veth_xdp_tx_bq *bq, 568 struct veth_stats *stats) 569 { 570 void *hard_start = frame->data - frame->headroom; 571 int len = frame->len, delta = 0; 572 struct xdp_frame orig_frame; 573 struct bpf_prog *xdp_prog; 574 unsigned int headroom; 575 struct sk_buff *skb; 576 577 /* bpf_xdp_adjust_head() assures BPF cannot access xdp_frame area */ 578 hard_start -= sizeof(struct xdp_frame); 579 580 rcu_read_lock(); 581 xdp_prog = rcu_dereference(rq->xdp_prog); 582 if (likely(xdp_prog)) { 583 struct xdp_buff xdp; 584 u32 act; 585 586 xdp_convert_frame_to_buff(frame, &xdp); 587 xdp.rxq = &rq->xdp_rxq; 588 589 act = bpf_prog_run_xdp(xdp_prog, &xdp); 590 591 switch (act) { 592 case XDP_PASS: 593 delta = frame->data - xdp.data; 594 len = xdp.data_end - xdp.data; 595 break; 596 case XDP_TX: 597 orig_frame = *frame; 598 xdp.rxq->mem = frame->mem; 599 if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) { 600 trace_xdp_exception(rq->dev, xdp_prog, act); 601 frame = &orig_frame; 602 stats->rx_drops++; 603 goto err_xdp; 604 } 605 stats->xdp_tx++; 606 rcu_read_unlock(); 607 goto xdp_xmit; 608 case XDP_REDIRECT: 609 orig_frame = *frame; 610 xdp.rxq->mem = frame->mem; 611 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) { 612 frame = &orig_frame; 613 stats->rx_drops++; 614 goto err_xdp; 615 } 616 stats->xdp_redirect++; 617 rcu_read_unlock(); 618 goto xdp_xmit; 619 default: 620 bpf_warn_invalid_xdp_action(act); 621 fallthrough; 622 case XDP_ABORTED: 623 trace_xdp_exception(rq->dev, xdp_prog, act); 624 fallthrough; 625 case XDP_DROP: 626 stats->xdp_drops++; 627 goto err_xdp; 628 } 629 } 630 rcu_read_unlock(); 631 632 headroom = sizeof(struct xdp_frame) + frame->headroom - delta; 633 skb = veth_build_skb(hard_start, headroom, len, frame->frame_sz); 634 if (!skb) { 635 xdp_return_frame(frame); 636 stats->rx_drops++; 637 goto err; 638 } 639 640 xdp_release_frame(frame); 641 xdp_scrub_frame(frame); 642 skb->protocol = eth_type_trans(skb, rq->dev); 643 err: 644 return skb; 645 err_xdp: 646 rcu_read_unlock(); 647 xdp_return_frame(frame); 648 xdp_xmit: 649 return NULL; 650 } 651 652 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq, 653 struct sk_buff *skb, 654 struct veth_xdp_tx_bq *bq, 655 struct veth_stats *stats) 656 { 657 u32 pktlen, headroom, act, metalen; 658 void *orig_data, *orig_data_end; 659 struct bpf_prog *xdp_prog; 660 int mac_len, delta, off; 661 struct xdp_buff xdp; 662 663 skb_orphan(skb); 664 665 rcu_read_lock(); 666 xdp_prog = rcu_dereference(rq->xdp_prog); 667 if (unlikely(!xdp_prog)) { 668 rcu_read_unlock(); 669 goto out; 670 } 671 672 mac_len = skb->data - skb_mac_header(skb); 673 pktlen = skb->len + mac_len; 674 headroom = skb_headroom(skb) - mac_len; 675 676 if (skb_shared(skb) || skb_head_is_locked(skb) || 677 skb_is_nonlinear(skb) || headroom < XDP_PACKET_HEADROOM) { 678 struct sk_buff *nskb; 679 int size, head_off; 680 void *head, *start; 681 struct page *page; 682 683 size = SKB_DATA_ALIGN(VETH_XDP_HEADROOM + pktlen) + 684 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); 685 if (size > PAGE_SIZE) 686 goto drop; 687 688 page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); 689 if (!page) 690 goto drop; 691 692 head = page_address(page); 693 start = head + VETH_XDP_HEADROOM; 694 if (skb_copy_bits(skb, -mac_len, start, pktlen)) { 695 page_frag_free(head); 696 goto drop; 697 } 698 699 nskb = veth_build_skb(head, VETH_XDP_HEADROOM + mac_len, 700 skb->len, 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; 718 719 /* SKB "head" area always have tailroom for skb_shared_info */ 720 xdp.frame_sz = (void *)skb_end_pointer(skb) - xdp.data_hard_start; 721 xdp.frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); 722 723 orig_data = xdp.data; 724 orig_data_end = xdp.data_end; 725 726 act = bpf_prog_run_xdp(xdp_prog, &xdp); 727 728 switch (act) { 729 case XDP_PASS: 730 break; 731 case XDP_TX: 732 get_page(virt_to_page(xdp.data)); 733 consume_skb(skb); 734 xdp.rxq->mem = rq->xdp_mem; 735 if (unlikely(veth_xdp_tx(rq, &xdp, bq) < 0)) { 736 trace_xdp_exception(rq->dev, xdp_prog, act); 737 stats->rx_drops++; 738 goto err_xdp; 739 } 740 stats->xdp_tx++; 741 rcu_read_unlock(); 742 goto xdp_xmit; 743 case XDP_REDIRECT: 744 get_page(virt_to_page(xdp.data)); 745 consume_skb(skb); 746 xdp.rxq->mem = rq->xdp_mem; 747 if (xdp_do_redirect(rq->dev, &xdp, xdp_prog)) { 748 stats->rx_drops++; 749 goto err_xdp; 750 } 751 stats->xdp_redirect++; 752 rcu_read_unlock(); 753 goto xdp_xmit; 754 default: 755 bpf_warn_invalid_xdp_action(act); 756 fallthrough; 757 case XDP_ABORTED: 758 trace_xdp_exception(rq->dev, xdp_prog, act); 759 fallthrough; 760 case XDP_DROP: 761 stats->xdp_drops++; 762 goto xdp_drop; 763 } 764 rcu_read_unlock(); 765 766 /* check if bpf_xdp_adjust_head was used */ 767 delta = orig_data - xdp.data; 768 off = mac_len + delta; 769 if (off > 0) 770 __skb_push(skb, off); 771 else if (off < 0) 772 __skb_pull(skb, -off); 773 skb->mac_header -= delta; 774 775 /* check if bpf_xdp_adjust_tail was used */ 776 off = xdp.data_end - orig_data_end; 777 if (off != 0) 778 __skb_put(skb, off); /* positive on grow, negative on shrink */ 779 skb->protocol = eth_type_trans(skb, rq->dev); 780 781 metalen = xdp.data - xdp.data_meta; 782 if (metalen) 783 skb_metadata_set(skb, metalen); 784 out: 785 return skb; 786 drop: 787 stats->rx_drops++; 788 xdp_drop: 789 rcu_read_unlock(); 790 kfree_skb(skb); 791 return NULL; 792 err_xdp: 793 rcu_read_unlock(); 794 page_frag_free(xdp.data); 795 xdp_xmit: 796 return NULL; 797 } 798 799 static int veth_xdp_rcv(struct veth_rq *rq, int budget, 800 struct veth_xdp_tx_bq *bq, 801 struct veth_stats *stats) 802 { 803 int i, done = 0; 804 805 for (i = 0; i < budget; i++) { 806 void *ptr = __ptr_ring_consume(&rq->xdp_ring); 807 struct sk_buff *skb; 808 809 if (!ptr) 810 break; 811 812 if (veth_is_xdp_frame(ptr)) { 813 struct xdp_frame *frame = veth_ptr_to_xdp(ptr); 814 815 stats->xdp_bytes += frame->len; 816 skb = veth_xdp_rcv_one(rq, frame, bq, stats); 817 } else { 818 skb = ptr; 819 stats->xdp_bytes += skb->len; 820 skb = veth_xdp_rcv_skb(rq, skb, bq, stats); 821 } 822 823 if (skb) 824 napi_gro_receive(&rq->xdp_napi, skb); 825 826 done++; 827 } 828 829 u64_stats_update_begin(&rq->stats.syncp); 830 rq->stats.vs.xdp_redirect += stats->xdp_redirect; 831 rq->stats.vs.xdp_bytes += stats->xdp_bytes; 832 rq->stats.vs.xdp_drops += stats->xdp_drops; 833 rq->stats.vs.rx_drops += stats->rx_drops; 834 rq->stats.vs.xdp_packets += done; 835 u64_stats_update_end(&rq->stats.syncp); 836 837 return done; 838 } 839 840 static int veth_poll(struct napi_struct *napi, int budget) 841 { 842 struct veth_rq *rq = 843 container_of(napi, struct veth_rq, xdp_napi); 844 struct veth_stats stats = {}; 845 struct veth_xdp_tx_bq bq; 846 int done; 847 848 bq.count = 0; 849 850 xdp_set_return_frame_no_direct(); 851 done = veth_xdp_rcv(rq, budget, &bq, &stats); 852 853 if (done < budget && napi_complete_done(napi, done)) { 854 /* Write rx_notify_masked before reading ptr_ring */ 855 smp_store_mb(rq->rx_notify_masked, false); 856 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) { 857 rq->rx_notify_masked = true; 858 napi_schedule(&rq->xdp_napi); 859 } 860 } 861 862 if (stats.xdp_tx > 0) 863 veth_xdp_flush(rq, &bq); 864 if (stats.xdp_redirect > 0) 865 xdp_do_flush(); 866 xdp_clear_return_frame_no_direct(); 867 868 return done; 869 } 870 871 static int veth_napi_add(struct net_device *dev) 872 { 873 struct veth_priv *priv = netdev_priv(dev); 874 int err, i; 875 876 for (i = 0; i < dev->real_num_rx_queues; i++) { 877 struct veth_rq *rq = &priv->rq[i]; 878 879 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL); 880 if (err) 881 goto err_xdp_ring; 882 } 883 884 for (i = 0; i < dev->real_num_rx_queues; i++) { 885 struct veth_rq *rq = &priv->rq[i]; 886 887 napi_enable(&rq->xdp_napi); 888 } 889 890 return 0; 891 err_xdp_ring: 892 for (i--; i >= 0; i--) 893 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free); 894 895 return err; 896 } 897 898 static void veth_napi_del(struct net_device *dev) 899 { 900 struct veth_priv *priv = netdev_priv(dev); 901 int i; 902 903 for (i = 0; i < dev->real_num_rx_queues; i++) { 904 struct veth_rq *rq = &priv->rq[i]; 905 906 napi_disable(&rq->xdp_napi); 907 __netif_napi_del(&rq->xdp_napi); 908 } 909 synchronize_net(); 910 911 for (i = 0; i < dev->real_num_rx_queues; i++) { 912 struct veth_rq *rq = &priv->rq[i]; 913 914 rq->rx_notify_masked = false; 915 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free); 916 } 917 } 918 919 static int veth_enable_xdp(struct net_device *dev) 920 { 921 struct veth_priv *priv = netdev_priv(dev); 922 int err, i; 923 924 if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) { 925 for (i = 0; i < dev->real_num_rx_queues; i++) { 926 struct veth_rq *rq = &priv->rq[i]; 927 928 netif_napi_add(dev, &rq->xdp_napi, veth_poll, NAPI_POLL_WEIGHT); 929 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id); 930 if (err < 0) 931 goto err_rxq_reg; 932 933 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq, 934 MEM_TYPE_PAGE_SHARED, 935 NULL); 936 if (err < 0) 937 goto err_reg_mem; 938 939 /* Save original mem info as it can be overwritten */ 940 rq->xdp_mem = rq->xdp_rxq.mem; 941 } 942 943 err = veth_napi_add(dev); 944 if (err) 945 goto err_rxq_reg; 946 } 947 948 for (i = 0; i < dev->real_num_rx_queues; i++) 949 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog); 950 951 return 0; 952 err_reg_mem: 953 xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq); 954 err_rxq_reg: 955 for (i--; i >= 0; i--) { 956 struct veth_rq *rq = &priv->rq[i]; 957 958 xdp_rxq_info_unreg(&rq->xdp_rxq); 959 netif_napi_del(&rq->xdp_napi); 960 } 961 962 return err; 963 } 964 965 static void veth_disable_xdp(struct net_device *dev) 966 { 967 struct veth_priv *priv = netdev_priv(dev); 968 int i; 969 970 for (i = 0; i < dev->real_num_rx_queues; i++) 971 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL); 972 veth_napi_del(dev); 973 for (i = 0; i < dev->real_num_rx_queues; i++) { 974 struct veth_rq *rq = &priv->rq[i]; 975 976 rq->xdp_rxq.mem = rq->xdp_mem; 977 xdp_rxq_info_unreg(&rq->xdp_rxq); 978 } 979 } 980 981 static int veth_open(struct net_device *dev) 982 { 983 struct veth_priv *priv = netdev_priv(dev); 984 struct net_device *peer = rtnl_dereference(priv->peer); 985 int err; 986 987 if (!peer) 988 return -ENOTCONN; 989 990 if (priv->_xdp_prog) { 991 err = veth_enable_xdp(dev); 992 if (err) 993 return err; 994 } 995 996 if (peer->flags & IFF_UP) { 997 netif_carrier_on(dev); 998 netif_carrier_on(peer); 999 } 1000 1001 return 0; 1002 } 1003 1004 static int veth_close(struct net_device *dev) 1005 { 1006 struct veth_priv *priv = netdev_priv(dev); 1007 struct net_device *peer = rtnl_dereference(priv->peer); 1008 1009 netif_carrier_off(dev); 1010 if (peer) 1011 netif_carrier_off(peer); 1012 1013 if (priv->_xdp_prog) 1014 veth_disable_xdp(dev); 1015 1016 return 0; 1017 } 1018 1019 static int is_valid_veth_mtu(int mtu) 1020 { 1021 return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU; 1022 } 1023 1024 static int veth_alloc_queues(struct net_device *dev) 1025 { 1026 struct veth_priv *priv = netdev_priv(dev); 1027 int i; 1028 1029 priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL); 1030 if (!priv->rq) 1031 return -ENOMEM; 1032 1033 for (i = 0; i < dev->num_rx_queues; i++) { 1034 priv->rq[i].dev = dev; 1035 u64_stats_init(&priv->rq[i].stats.syncp); 1036 } 1037 1038 return 0; 1039 } 1040 1041 static void veth_free_queues(struct net_device *dev) 1042 { 1043 struct veth_priv *priv = netdev_priv(dev); 1044 1045 kfree(priv->rq); 1046 } 1047 1048 static int veth_dev_init(struct net_device *dev) 1049 { 1050 int err; 1051 1052 dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats); 1053 if (!dev->lstats) 1054 return -ENOMEM; 1055 1056 err = veth_alloc_queues(dev); 1057 if (err) { 1058 free_percpu(dev->lstats); 1059 return err; 1060 } 1061 1062 return 0; 1063 } 1064 1065 static void veth_dev_free(struct net_device *dev) 1066 { 1067 veth_free_queues(dev); 1068 free_percpu(dev->lstats); 1069 } 1070 1071 #ifdef CONFIG_NET_POLL_CONTROLLER 1072 static void veth_poll_controller(struct net_device *dev) 1073 { 1074 /* veth only receives frames when its peer sends one 1075 * Since it has nothing to do with disabling irqs, we are guaranteed 1076 * never to have pending data when we poll for it so 1077 * there is nothing to do here. 1078 * 1079 * We need this though so netpoll recognizes us as an interface that 1080 * supports polling, which enables bridge devices in virt setups to 1081 * still use netconsole 1082 */ 1083 } 1084 #endif /* CONFIG_NET_POLL_CONTROLLER */ 1085 1086 static int veth_get_iflink(const struct net_device *dev) 1087 { 1088 struct veth_priv *priv = netdev_priv(dev); 1089 struct net_device *peer; 1090 int iflink; 1091 1092 rcu_read_lock(); 1093 peer = rcu_dereference(priv->peer); 1094 iflink = peer ? peer->ifindex : 0; 1095 rcu_read_unlock(); 1096 1097 return iflink; 1098 } 1099 1100 static netdev_features_t veth_fix_features(struct net_device *dev, 1101 netdev_features_t features) 1102 { 1103 struct veth_priv *priv = netdev_priv(dev); 1104 struct net_device *peer; 1105 1106 peer = rtnl_dereference(priv->peer); 1107 if (peer) { 1108 struct veth_priv *peer_priv = netdev_priv(peer); 1109 1110 if (peer_priv->_xdp_prog) 1111 features &= ~NETIF_F_GSO_SOFTWARE; 1112 } 1113 1114 return features; 1115 } 1116 1117 static void veth_set_rx_headroom(struct net_device *dev, int new_hr) 1118 { 1119 struct veth_priv *peer_priv, *priv = netdev_priv(dev); 1120 struct net_device *peer; 1121 1122 if (new_hr < 0) 1123 new_hr = 0; 1124 1125 rcu_read_lock(); 1126 peer = rcu_dereference(priv->peer); 1127 if (unlikely(!peer)) 1128 goto out; 1129 1130 peer_priv = netdev_priv(peer); 1131 priv->requested_headroom = new_hr; 1132 new_hr = max(priv->requested_headroom, peer_priv->requested_headroom); 1133 dev->needed_headroom = new_hr; 1134 peer->needed_headroom = new_hr; 1135 1136 out: 1137 rcu_read_unlock(); 1138 } 1139 1140 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog, 1141 struct netlink_ext_ack *extack) 1142 { 1143 struct veth_priv *priv = netdev_priv(dev); 1144 struct bpf_prog *old_prog; 1145 struct net_device *peer; 1146 unsigned int max_mtu; 1147 int err; 1148 1149 old_prog = priv->_xdp_prog; 1150 priv->_xdp_prog = prog; 1151 peer = rtnl_dereference(priv->peer); 1152 1153 if (prog) { 1154 if (!peer) { 1155 NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached"); 1156 err = -ENOTCONN; 1157 goto err; 1158 } 1159 1160 max_mtu = PAGE_SIZE - VETH_XDP_HEADROOM - 1161 peer->hard_header_len - 1162 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); 1163 if (peer->mtu > max_mtu) { 1164 NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP"); 1165 err = -ERANGE; 1166 goto err; 1167 } 1168 1169 if (dev->real_num_rx_queues < peer->real_num_tx_queues) { 1170 NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues"); 1171 err = -ENOSPC; 1172 goto err; 1173 } 1174 1175 if (dev->flags & IFF_UP) { 1176 err = veth_enable_xdp(dev); 1177 if (err) { 1178 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed"); 1179 goto err; 1180 } 1181 } 1182 1183 if (!old_prog) { 1184 peer->hw_features &= ~NETIF_F_GSO_SOFTWARE; 1185 peer->max_mtu = max_mtu; 1186 } 1187 } 1188 1189 if (old_prog) { 1190 if (!prog) { 1191 if (dev->flags & IFF_UP) 1192 veth_disable_xdp(dev); 1193 1194 if (peer) { 1195 peer->hw_features |= NETIF_F_GSO_SOFTWARE; 1196 peer->max_mtu = ETH_MAX_MTU; 1197 } 1198 } 1199 bpf_prog_put(old_prog); 1200 } 1201 1202 if ((!!old_prog ^ !!prog) && peer) 1203 netdev_update_features(peer); 1204 1205 return 0; 1206 err: 1207 priv->_xdp_prog = old_prog; 1208 1209 return err; 1210 } 1211 1212 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp) 1213 { 1214 switch (xdp->command) { 1215 case XDP_SETUP_PROG: 1216 return veth_xdp_set(dev, xdp->prog, xdp->extack); 1217 default: 1218 return -EINVAL; 1219 } 1220 } 1221 1222 static const struct net_device_ops veth_netdev_ops = { 1223 .ndo_init = veth_dev_init, 1224 .ndo_open = veth_open, 1225 .ndo_stop = veth_close, 1226 .ndo_start_xmit = veth_xmit, 1227 .ndo_get_stats64 = veth_get_stats64, 1228 .ndo_set_rx_mode = veth_set_multicast_list, 1229 .ndo_set_mac_address = eth_mac_addr, 1230 #ifdef CONFIG_NET_POLL_CONTROLLER 1231 .ndo_poll_controller = veth_poll_controller, 1232 #endif 1233 .ndo_get_iflink = veth_get_iflink, 1234 .ndo_fix_features = veth_fix_features, 1235 .ndo_features_check = passthru_features_check, 1236 .ndo_set_rx_headroom = veth_set_rx_headroom, 1237 .ndo_bpf = veth_xdp, 1238 .ndo_xdp_xmit = veth_ndo_xdp_xmit, 1239 .ndo_get_peer_dev = veth_peer_dev, 1240 }; 1241 1242 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \ 1243 NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \ 1244 NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \ 1245 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \ 1246 NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX ) 1247 1248 static void veth_setup(struct net_device *dev) 1249 { 1250 ether_setup(dev); 1251 1252 dev->priv_flags &= ~IFF_TX_SKB_SHARING; 1253 dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; 1254 dev->priv_flags |= IFF_NO_QUEUE; 1255 dev->priv_flags |= IFF_PHONY_HEADROOM; 1256 1257 dev->netdev_ops = &veth_netdev_ops; 1258 dev->ethtool_ops = &veth_ethtool_ops; 1259 dev->features |= NETIF_F_LLTX; 1260 dev->features |= VETH_FEATURES; 1261 dev->vlan_features = dev->features & 1262 ~(NETIF_F_HW_VLAN_CTAG_TX | 1263 NETIF_F_HW_VLAN_STAG_TX | 1264 NETIF_F_HW_VLAN_CTAG_RX | 1265 NETIF_F_HW_VLAN_STAG_RX); 1266 dev->needs_free_netdev = true; 1267 dev->priv_destructor = veth_dev_free; 1268 dev->max_mtu = ETH_MAX_MTU; 1269 1270 dev->hw_features = VETH_FEATURES; 1271 dev->hw_enc_features = VETH_FEATURES; 1272 dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE; 1273 } 1274 1275 /* 1276 * netlink interface 1277 */ 1278 1279 static int veth_validate(struct nlattr *tb[], struct nlattr *data[], 1280 struct netlink_ext_ack *extack) 1281 { 1282 if (tb[IFLA_ADDRESS]) { 1283 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) 1284 return -EINVAL; 1285 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) 1286 return -EADDRNOTAVAIL; 1287 } 1288 if (tb[IFLA_MTU]) { 1289 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU]))) 1290 return -EINVAL; 1291 } 1292 return 0; 1293 } 1294 1295 static struct rtnl_link_ops veth_link_ops; 1296 1297 static int veth_newlink(struct net *src_net, struct net_device *dev, 1298 struct nlattr *tb[], struct nlattr *data[], 1299 struct netlink_ext_ack *extack) 1300 { 1301 int err; 1302 struct net_device *peer; 1303 struct veth_priv *priv; 1304 char ifname[IFNAMSIZ]; 1305 struct nlattr *peer_tb[IFLA_MAX + 1], **tbp; 1306 unsigned char name_assign_type; 1307 struct ifinfomsg *ifmp; 1308 struct net *net; 1309 1310 /* 1311 * create and register peer first 1312 */ 1313 if (data != NULL && data[VETH_INFO_PEER] != NULL) { 1314 struct nlattr *nla_peer; 1315 1316 nla_peer = data[VETH_INFO_PEER]; 1317 ifmp = nla_data(nla_peer); 1318 err = rtnl_nla_parse_ifla(peer_tb, 1319 nla_data(nla_peer) + sizeof(struct ifinfomsg), 1320 nla_len(nla_peer) - sizeof(struct ifinfomsg), 1321 NULL); 1322 if (err < 0) 1323 return err; 1324 1325 err = veth_validate(peer_tb, NULL, extack); 1326 if (err < 0) 1327 return err; 1328 1329 tbp = peer_tb; 1330 } else { 1331 ifmp = NULL; 1332 tbp = tb; 1333 } 1334 1335 if (ifmp && tbp[IFLA_IFNAME]) { 1336 nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ); 1337 name_assign_type = NET_NAME_USER; 1338 } else { 1339 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d"); 1340 name_assign_type = NET_NAME_ENUM; 1341 } 1342 1343 net = rtnl_link_get_net(src_net, tbp); 1344 if (IS_ERR(net)) 1345 return PTR_ERR(net); 1346 1347 peer = rtnl_create_link(net, ifname, name_assign_type, 1348 &veth_link_ops, tbp, extack); 1349 if (IS_ERR(peer)) { 1350 put_net(net); 1351 return PTR_ERR(peer); 1352 } 1353 1354 if (!ifmp || !tbp[IFLA_ADDRESS]) 1355 eth_hw_addr_random(peer); 1356 1357 if (ifmp && (dev->ifindex != 0)) 1358 peer->ifindex = ifmp->ifi_index; 1359 1360 peer->gso_max_size = dev->gso_max_size; 1361 peer->gso_max_segs = dev->gso_max_segs; 1362 1363 err = register_netdevice(peer); 1364 put_net(net); 1365 net = NULL; 1366 if (err < 0) 1367 goto err_register_peer; 1368 1369 netif_carrier_off(peer); 1370 1371 err = rtnl_configure_link(peer, ifmp); 1372 if (err < 0) 1373 goto err_configure_peer; 1374 1375 /* 1376 * register dev last 1377 * 1378 * note, that since we've registered new device the dev's name 1379 * should be re-allocated 1380 */ 1381 1382 if (tb[IFLA_ADDRESS] == NULL) 1383 eth_hw_addr_random(dev); 1384 1385 if (tb[IFLA_IFNAME]) 1386 nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ); 1387 else 1388 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d"); 1389 1390 err = register_netdevice(dev); 1391 if (err < 0) 1392 goto err_register_dev; 1393 1394 netif_carrier_off(dev); 1395 1396 /* 1397 * tie the deviced together 1398 */ 1399 1400 priv = netdev_priv(dev); 1401 rcu_assign_pointer(priv->peer, peer); 1402 1403 priv = netdev_priv(peer); 1404 rcu_assign_pointer(priv->peer, dev); 1405 1406 return 0; 1407 1408 err_register_dev: 1409 /* nothing to do */ 1410 err_configure_peer: 1411 unregister_netdevice(peer); 1412 return err; 1413 1414 err_register_peer: 1415 free_netdev(peer); 1416 return err; 1417 } 1418 1419 static void veth_dellink(struct net_device *dev, struct list_head *head) 1420 { 1421 struct veth_priv *priv; 1422 struct net_device *peer; 1423 1424 priv = netdev_priv(dev); 1425 peer = rtnl_dereference(priv->peer); 1426 1427 /* Note : dellink() is called from default_device_exit_batch(), 1428 * before a rcu_synchronize() point. The devices are guaranteed 1429 * not being freed before one RCU grace period. 1430 */ 1431 RCU_INIT_POINTER(priv->peer, NULL); 1432 unregister_netdevice_queue(dev, head); 1433 1434 if (peer) { 1435 priv = netdev_priv(peer); 1436 RCU_INIT_POINTER(priv->peer, NULL); 1437 unregister_netdevice_queue(peer, head); 1438 } 1439 } 1440 1441 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = { 1442 [VETH_INFO_PEER] = { .len = sizeof(struct ifinfomsg) }, 1443 }; 1444 1445 static struct net *veth_get_link_net(const struct net_device *dev) 1446 { 1447 struct veth_priv *priv = netdev_priv(dev); 1448 struct net_device *peer = rtnl_dereference(priv->peer); 1449 1450 return peer ? dev_net(peer) : dev_net(dev); 1451 } 1452 1453 static struct rtnl_link_ops veth_link_ops = { 1454 .kind = DRV_NAME, 1455 .priv_size = sizeof(struct veth_priv), 1456 .setup = veth_setup, 1457 .validate = veth_validate, 1458 .newlink = veth_newlink, 1459 .dellink = veth_dellink, 1460 .policy = veth_policy, 1461 .maxtype = VETH_INFO_MAX, 1462 .get_link_net = veth_get_link_net, 1463 }; 1464 1465 /* 1466 * init/fini 1467 */ 1468 1469 static __init int veth_init(void) 1470 { 1471 return rtnl_link_register(&veth_link_ops); 1472 } 1473 1474 static __exit void veth_exit(void) 1475 { 1476 rtnl_link_unregister(&veth_link_ops); 1477 } 1478 1479 module_init(veth_init); 1480 module_exit(veth_exit); 1481 1482 MODULE_DESCRIPTION("Virtual Ethernet Tunnel"); 1483 MODULE_LICENSE("GPL v2"); 1484 MODULE_ALIAS_RTNL_LINK(DRV_NAME); 1485