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