1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Monitoring code for network dropped packet alerts 4 * 5 * Copyright (C) 2009 Neil Horman <nhorman@tuxdriver.com> 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/netdevice.h> 11 #include <linux/etherdevice.h> 12 #include <linux/string.h> 13 #include <linux/if_arp.h> 14 #include <linux/inetdevice.h> 15 #include <linux/inet.h> 16 #include <linux/interrupt.h> 17 #include <linux/netpoll.h> 18 #include <linux/sched.h> 19 #include <linux/delay.h> 20 #include <linux/types.h> 21 #include <linux/workqueue.h> 22 #include <linux/netlink.h> 23 #include <linux/net_dropmon.h> 24 #include <linux/percpu.h> 25 #include <linux/timer.h> 26 #include <linux/bitops.h> 27 #include <linux/slab.h> 28 #include <linux/module.h> 29 #include <net/genetlink.h> 30 #include <net/netevent.h> 31 #include <net/flow_offload.h> 32 #include <net/devlink.h> 33 34 #include <trace/events/skb.h> 35 #include <trace/events/napi.h> 36 #include <trace/events/devlink.h> 37 38 #include <asm/unaligned.h> 39 40 #define TRACE_ON 1 41 #define TRACE_OFF 0 42 43 /* 44 * Globals, our netlink socket pointer 45 * and the work handle that will send up 46 * netlink alerts 47 */ 48 static int trace_state = TRACE_OFF; 49 static bool monitor_hw; 50 51 /* net_dm_mutex 52 * 53 * An overall lock guarding every operation coming from userspace. 54 * It also guards the global 'hw_stats_list' list. 55 */ 56 static DEFINE_MUTEX(net_dm_mutex); 57 58 struct net_dm_stats { 59 u64 dropped; 60 struct u64_stats_sync syncp; 61 }; 62 63 #define NET_DM_MAX_HW_TRAP_NAME_LEN 40 64 65 struct net_dm_hw_entry { 66 char trap_name[NET_DM_MAX_HW_TRAP_NAME_LEN]; 67 u32 count; 68 }; 69 70 struct net_dm_hw_entries { 71 u32 num_entries; 72 struct net_dm_hw_entry entries[]; 73 }; 74 75 struct per_cpu_dm_data { 76 spinlock_t lock; /* Protects 'skb', 'hw_entries' and 77 * 'send_timer' 78 */ 79 union { 80 struct sk_buff *skb; 81 struct net_dm_hw_entries *hw_entries; 82 }; 83 struct sk_buff_head drop_queue; 84 struct work_struct dm_alert_work; 85 struct timer_list send_timer; 86 struct net_dm_stats stats; 87 }; 88 89 struct dm_hw_stat_delta { 90 struct net_device *dev; 91 unsigned long last_rx; 92 struct list_head list; 93 struct rcu_head rcu; 94 unsigned long last_drop_val; 95 }; 96 97 static struct genl_family net_drop_monitor_family; 98 99 static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data); 100 static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_hw_cpu_data); 101 102 static int dm_hit_limit = 64; 103 static int dm_delay = 1; 104 static unsigned long dm_hw_check_delta = 2*HZ; 105 static LIST_HEAD(hw_stats_list); 106 107 static enum net_dm_alert_mode net_dm_alert_mode = NET_DM_ALERT_MODE_SUMMARY; 108 static u32 net_dm_trunc_len; 109 static u32 net_dm_queue_len = 1000; 110 111 struct net_dm_alert_ops { 112 void (*kfree_skb_probe)(void *ignore, struct sk_buff *skb, 113 void *location, 114 enum skb_drop_reason reason); 115 void (*napi_poll_probe)(void *ignore, struct napi_struct *napi, 116 int work, int budget); 117 void (*work_item_func)(struct work_struct *work); 118 void (*hw_work_item_func)(struct work_struct *work); 119 void (*hw_trap_probe)(void *ignore, const struct devlink *devlink, 120 struct sk_buff *skb, 121 const struct devlink_trap_metadata *metadata); 122 }; 123 124 struct net_dm_skb_cb { 125 union { 126 struct devlink_trap_metadata *hw_metadata; 127 void *pc; 128 }; 129 }; 130 131 #define NET_DM_SKB_CB(__skb) ((struct net_dm_skb_cb *)&((__skb)->cb[0])) 132 133 static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data) 134 { 135 size_t al; 136 struct net_dm_alert_msg *msg; 137 struct nlattr *nla; 138 struct sk_buff *skb; 139 unsigned long flags; 140 void *msg_header; 141 142 al = sizeof(struct net_dm_alert_msg); 143 al += dm_hit_limit * sizeof(struct net_dm_drop_point); 144 al += sizeof(struct nlattr); 145 146 skb = genlmsg_new(al, GFP_KERNEL); 147 148 if (!skb) 149 goto err; 150 151 msg_header = genlmsg_put(skb, 0, 0, &net_drop_monitor_family, 152 0, NET_DM_CMD_ALERT); 153 if (!msg_header) { 154 nlmsg_free(skb); 155 skb = NULL; 156 goto err; 157 } 158 nla = nla_reserve(skb, NLA_UNSPEC, 159 sizeof(struct net_dm_alert_msg)); 160 if (!nla) { 161 nlmsg_free(skb); 162 skb = NULL; 163 goto err; 164 } 165 msg = nla_data(nla); 166 memset(msg, 0, al); 167 goto out; 168 169 err: 170 mod_timer(&data->send_timer, jiffies + HZ / 10); 171 out: 172 spin_lock_irqsave(&data->lock, flags); 173 swap(data->skb, skb); 174 spin_unlock_irqrestore(&data->lock, flags); 175 176 if (skb) { 177 struct nlmsghdr *nlh = (struct nlmsghdr *)skb->data; 178 struct genlmsghdr *gnlh = (struct genlmsghdr *)nlmsg_data(nlh); 179 180 genlmsg_end(skb, genlmsg_data(gnlh)); 181 } 182 183 return skb; 184 } 185 186 static const struct genl_multicast_group dropmon_mcgrps[] = { 187 { .name = "events", }, 188 }; 189 190 static void send_dm_alert(struct work_struct *work) 191 { 192 struct sk_buff *skb; 193 struct per_cpu_dm_data *data; 194 195 data = container_of(work, struct per_cpu_dm_data, dm_alert_work); 196 197 skb = reset_per_cpu_data(data); 198 199 if (skb) 200 genlmsg_multicast(&net_drop_monitor_family, skb, 0, 201 0, GFP_KERNEL); 202 } 203 204 /* 205 * This is the timer function to delay the sending of an alert 206 * in the event that more drops will arrive during the 207 * hysteresis period. 208 */ 209 static void sched_send_work(struct timer_list *t) 210 { 211 struct per_cpu_dm_data *data = from_timer(data, t, send_timer); 212 213 schedule_work(&data->dm_alert_work); 214 } 215 216 static void trace_drop_common(struct sk_buff *skb, void *location) 217 { 218 struct net_dm_alert_msg *msg; 219 struct net_dm_drop_point *point; 220 struct nlmsghdr *nlh; 221 struct nlattr *nla; 222 int i; 223 struct sk_buff *dskb; 224 struct per_cpu_dm_data *data; 225 unsigned long flags; 226 227 local_irq_save(flags); 228 data = this_cpu_ptr(&dm_cpu_data); 229 spin_lock(&data->lock); 230 dskb = data->skb; 231 232 if (!dskb) 233 goto out; 234 235 nlh = (struct nlmsghdr *)dskb->data; 236 nla = genlmsg_data(nlmsg_data(nlh)); 237 msg = nla_data(nla); 238 point = msg->points; 239 for (i = 0; i < msg->entries; i++) { 240 if (!memcmp(&location, &point->pc, sizeof(void *))) { 241 point->count++; 242 goto out; 243 } 244 point++; 245 } 246 if (msg->entries == dm_hit_limit) 247 goto out; 248 /* 249 * We need to create a new entry 250 */ 251 __nla_reserve_nohdr(dskb, sizeof(struct net_dm_drop_point)); 252 nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point)); 253 memcpy(point->pc, &location, sizeof(void *)); 254 point->count = 1; 255 msg->entries++; 256 257 if (!timer_pending(&data->send_timer)) { 258 data->send_timer.expires = jiffies + dm_delay * HZ; 259 add_timer(&data->send_timer); 260 } 261 262 out: 263 spin_unlock_irqrestore(&data->lock, flags); 264 } 265 266 static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, 267 void *location, 268 enum skb_drop_reason reason) 269 { 270 trace_drop_common(skb, location); 271 } 272 273 static void trace_napi_poll_hit(void *ignore, struct napi_struct *napi, 274 int work, int budget) 275 { 276 struct dm_hw_stat_delta *new_stat; 277 278 /* 279 * Don't check napi structures with no associated device 280 */ 281 if (!napi->dev) 282 return; 283 284 rcu_read_lock(); 285 list_for_each_entry_rcu(new_stat, &hw_stats_list, list) { 286 struct net_device *dev; 287 288 /* 289 * only add a note to our monitor buffer if: 290 * 1) this is the dev we received on 291 * 2) its after the last_rx delta 292 * 3) our rx_dropped count has gone up 293 */ 294 /* Paired with WRITE_ONCE() in dropmon_net_event() */ 295 dev = READ_ONCE(new_stat->dev); 296 if ((dev == napi->dev) && 297 (time_after(jiffies, new_stat->last_rx + dm_hw_check_delta)) && 298 (napi->dev->stats.rx_dropped != new_stat->last_drop_val)) { 299 trace_drop_common(NULL, NULL); 300 new_stat->last_drop_val = napi->dev->stats.rx_dropped; 301 new_stat->last_rx = jiffies; 302 break; 303 } 304 } 305 rcu_read_unlock(); 306 } 307 308 static struct net_dm_hw_entries * 309 net_dm_hw_reset_per_cpu_data(struct per_cpu_dm_data *hw_data) 310 { 311 struct net_dm_hw_entries *hw_entries; 312 unsigned long flags; 313 314 hw_entries = kzalloc(struct_size(hw_entries, entries, dm_hit_limit), 315 GFP_KERNEL); 316 if (!hw_entries) { 317 /* If the memory allocation failed, we try to perform another 318 * allocation in 1/10 second. Otherwise, the probe function 319 * will constantly bail out. 320 */ 321 mod_timer(&hw_data->send_timer, jiffies + HZ / 10); 322 } 323 324 spin_lock_irqsave(&hw_data->lock, flags); 325 swap(hw_data->hw_entries, hw_entries); 326 spin_unlock_irqrestore(&hw_data->lock, flags); 327 328 return hw_entries; 329 } 330 331 static int net_dm_hw_entry_put(struct sk_buff *msg, 332 const struct net_dm_hw_entry *hw_entry) 333 { 334 struct nlattr *attr; 335 336 attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRY); 337 if (!attr) 338 return -EMSGSIZE; 339 340 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME, hw_entry->trap_name)) 341 goto nla_put_failure; 342 343 if (nla_put_u32(msg, NET_DM_ATTR_HW_TRAP_COUNT, hw_entry->count)) 344 goto nla_put_failure; 345 346 nla_nest_end(msg, attr); 347 348 return 0; 349 350 nla_put_failure: 351 nla_nest_cancel(msg, attr); 352 return -EMSGSIZE; 353 } 354 355 static int net_dm_hw_entries_put(struct sk_buff *msg, 356 const struct net_dm_hw_entries *hw_entries) 357 { 358 struct nlattr *attr; 359 int i; 360 361 attr = nla_nest_start(msg, NET_DM_ATTR_HW_ENTRIES); 362 if (!attr) 363 return -EMSGSIZE; 364 365 for (i = 0; i < hw_entries->num_entries; i++) { 366 int rc; 367 368 rc = net_dm_hw_entry_put(msg, &hw_entries->entries[i]); 369 if (rc) 370 goto nla_put_failure; 371 } 372 373 nla_nest_end(msg, attr); 374 375 return 0; 376 377 nla_put_failure: 378 nla_nest_cancel(msg, attr); 379 return -EMSGSIZE; 380 } 381 382 static int 383 net_dm_hw_summary_report_fill(struct sk_buff *msg, 384 const struct net_dm_hw_entries *hw_entries) 385 { 386 struct net_dm_alert_msg anc_hdr = { 0 }; 387 void *hdr; 388 int rc; 389 390 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0, 391 NET_DM_CMD_ALERT); 392 if (!hdr) 393 return -EMSGSIZE; 394 395 /* We need to put the ancillary header in order not to break user 396 * space. 397 */ 398 if (nla_put(msg, NLA_UNSPEC, sizeof(anc_hdr), &anc_hdr)) 399 goto nla_put_failure; 400 401 rc = net_dm_hw_entries_put(msg, hw_entries); 402 if (rc) 403 goto nla_put_failure; 404 405 genlmsg_end(msg, hdr); 406 407 return 0; 408 409 nla_put_failure: 410 genlmsg_cancel(msg, hdr); 411 return -EMSGSIZE; 412 } 413 414 static void net_dm_hw_summary_work(struct work_struct *work) 415 { 416 struct net_dm_hw_entries *hw_entries; 417 struct per_cpu_dm_data *hw_data; 418 struct sk_buff *msg; 419 int rc; 420 421 hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work); 422 423 hw_entries = net_dm_hw_reset_per_cpu_data(hw_data); 424 if (!hw_entries) 425 return; 426 427 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 428 if (!msg) 429 goto out; 430 431 rc = net_dm_hw_summary_report_fill(msg, hw_entries); 432 if (rc) { 433 nlmsg_free(msg); 434 goto out; 435 } 436 437 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL); 438 439 out: 440 kfree(hw_entries); 441 } 442 443 static void 444 net_dm_hw_trap_summary_probe(void *ignore, const struct devlink *devlink, 445 struct sk_buff *skb, 446 const struct devlink_trap_metadata *metadata) 447 { 448 struct net_dm_hw_entries *hw_entries; 449 struct net_dm_hw_entry *hw_entry; 450 struct per_cpu_dm_data *hw_data; 451 unsigned long flags; 452 int i; 453 454 if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL) 455 return; 456 457 hw_data = this_cpu_ptr(&dm_hw_cpu_data); 458 spin_lock_irqsave(&hw_data->lock, flags); 459 hw_entries = hw_data->hw_entries; 460 461 if (!hw_entries) 462 goto out; 463 464 for (i = 0; i < hw_entries->num_entries; i++) { 465 hw_entry = &hw_entries->entries[i]; 466 if (!strncmp(hw_entry->trap_name, metadata->trap_name, 467 NET_DM_MAX_HW_TRAP_NAME_LEN - 1)) { 468 hw_entry->count++; 469 goto out; 470 } 471 } 472 if (WARN_ON_ONCE(hw_entries->num_entries == dm_hit_limit)) 473 goto out; 474 475 hw_entry = &hw_entries->entries[hw_entries->num_entries]; 476 strlcpy(hw_entry->trap_name, metadata->trap_name, 477 NET_DM_MAX_HW_TRAP_NAME_LEN - 1); 478 hw_entry->count = 1; 479 hw_entries->num_entries++; 480 481 if (!timer_pending(&hw_data->send_timer)) { 482 hw_data->send_timer.expires = jiffies + dm_delay * HZ; 483 add_timer(&hw_data->send_timer); 484 } 485 486 out: 487 spin_unlock_irqrestore(&hw_data->lock, flags); 488 } 489 490 static const struct net_dm_alert_ops net_dm_alert_summary_ops = { 491 .kfree_skb_probe = trace_kfree_skb_hit, 492 .napi_poll_probe = trace_napi_poll_hit, 493 .work_item_func = send_dm_alert, 494 .hw_work_item_func = net_dm_hw_summary_work, 495 .hw_trap_probe = net_dm_hw_trap_summary_probe, 496 }; 497 498 static void net_dm_packet_trace_kfree_skb_hit(void *ignore, 499 struct sk_buff *skb, 500 void *location, 501 enum skb_drop_reason reason) 502 { 503 ktime_t tstamp = ktime_get_real(); 504 struct per_cpu_dm_data *data; 505 struct sk_buff *nskb; 506 unsigned long flags; 507 508 if (!skb_mac_header_was_set(skb)) 509 return; 510 511 nskb = skb_clone(skb, GFP_ATOMIC); 512 if (!nskb) 513 return; 514 515 NET_DM_SKB_CB(nskb)->pc = location; 516 /* Override the timestamp because we care about the time when the 517 * packet was dropped. 518 */ 519 nskb->tstamp = tstamp; 520 521 data = this_cpu_ptr(&dm_cpu_data); 522 523 spin_lock_irqsave(&data->drop_queue.lock, flags); 524 if (skb_queue_len(&data->drop_queue) < net_dm_queue_len) 525 __skb_queue_tail(&data->drop_queue, nskb); 526 else 527 goto unlock_free; 528 spin_unlock_irqrestore(&data->drop_queue.lock, flags); 529 530 schedule_work(&data->dm_alert_work); 531 532 return; 533 534 unlock_free: 535 spin_unlock_irqrestore(&data->drop_queue.lock, flags); 536 u64_stats_update_begin(&data->stats.syncp); 537 data->stats.dropped++; 538 u64_stats_update_end(&data->stats.syncp); 539 consume_skb(nskb); 540 } 541 542 static void net_dm_packet_trace_napi_poll_hit(void *ignore, 543 struct napi_struct *napi, 544 int work, int budget) 545 { 546 } 547 548 static size_t net_dm_in_port_size(void) 549 { 550 /* NET_DM_ATTR_IN_PORT nest */ 551 return nla_total_size(0) + 552 /* NET_DM_ATTR_PORT_NETDEV_IFINDEX */ 553 nla_total_size(sizeof(u32)) + 554 /* NET_DM_ATTR_PORT_NETDEV_NAME */ 555 nla_total_size(IFNAMSIZ + 1); 556 } 557 558 #define NET_DM_MAX_SYMBOL_LEN 40 559 560 static size_t net_dm_packet_report_size(size_t payload_len) 561 { 562 size_t size; 563 564 size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize); 565 566 return NLMSG_ALIGN(size) + 567 /* NET_DM_ATTR_ORIGIN */ 568 nla_total_size(sizeof(u16)) + 569 /* NET_DM_ATTR_PC */ 570 nla_total_size(sizeof(u64)) + 571 /* NET_DM_ATTR_SYMBOL */ 572 nla_total_size(NET_DM_MAX_SYMBOL_LEN + 1) + 573 /* NET_DM_ATTR_IN_PORT */ 574 net_dm_in_port_size() + 575 /* NET_DM_ATTR_TIMESTAMP */ 576 nla_total_size(sizeof(u64)) + 577 /* NET_DM_ATTR_ORIG_LEN */ 578 nla_total_size(sizeof(u32)) + 579 /* NET_DM_ATTR_PROTO */ 580 nla_total_size(sizeof(u16)) + 581 /* NET_DM_ATTR_PAYLOAD */ 582 nla_total_size(payload_len); 583 } 584 585 static int net_dm_packet_report_in_port_put(struct sk_buff *msg, int ifindex, 586 const char *name) 587 { 588 struct nlattr *attr; 589 590 attr = nla_nest_start(msg, NET_DM_ATTR_IN_PORT); 591 if (!attr) 592 return -EMSGSIZE; 593 594 if (ifindex && 595 nla_put_u32(msg, NET_DM_ATTR_PORT_NETDEV_IFINDEX, ifindex)) 596 goto nla_put_failure; 597 598 if (name && nla_put_string(msg, NET_DM_ATTR_PORT_NETDEV_NAME, name)) 599 goto nla_put_failure; 600 601 nla_nest_end(msg, attr); 602 603 return 0; 604 605 nla_put_failure: 606 nla_nest_cancel(msg, attr); 607 return -EMSGSIZE; 608 } 609 610 static int net_dm_packet_report_fill(struct sk_buff *msg, struct sk_buff *skb, 611 size_t payload_len) 612 { 613 u64 pc = (u64)(uintptr_t) NET_DM_SKB_CB(skb)->pc; 614 char buf[NET_DM_MAX_SYMBOL_LEN]; 615 struct nlattr *attr; 616 void *hdr; 617 int rc; 618 619 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0, 620 NET_DM_CMD_PACKET_ALERT); 621 if (!hdr) 622 return -EMSGSIZE; 623 624 if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_SW)) 625 goto nla_put_failure; 626 627 if (nla_put_u64_64bit(msg, NET_DM_ATTR_PC, pc, NET_DM_ATTR_PAD)) 628 goto nla_put_failure; 629 630 snprintf(buf, sizeof(buf), "%pS", NET_DM_SKB_CB(skb)->pc); 631 if (nla_put_string(msg, NET_DM_ATTR_SYMBOL, buf)) 632 goto nla_put_failure; 633 634 rc = net_dm_packet_report_in_port_put(msg, skb->skb_iif, NULL); 635 if (rc) 636 goto nla_put_failure; 637 638 if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP, 639 ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD)) 640 goto nla_put_failure; 641 642 if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len)) 643 goto nla_put_failure; 644 645 if (!payload_len) 646 goto out; 647 648 if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol))) 649 goto nla_put_failure; 650 651 attr = skb_put(msg, nla_total_size(payload_len)); 652 attr->nla_type = NET_DM_ATTR_PAYLOAD; 653 attr->nla_len = nla_attr_size(payload_len); 654 if (skb_copy_bits(skb, 0, nla_data(attr), payload_len)) 655 goto nla_put_failure; 656 657 out: 658 genlmsg_end(msg, hdr); 659 660 return 0; 661 662 nla_put_failure: 663 genlmsg_cancel(msg, hdr); 664 return -EMSGSIZE; 665 } 666 667 #define NET_DM_MAX_PACKET_SIZE (0xffff - NLA_HDRLEN - NLA_ALIGNTO) 668 669 static void net_dm_packet_report(struct sk_buff *skb) 670 { 671 struct sk_buff *msg; 672 size_t payload_len; 673 int rc; 674 675 /* Make sure we start copying the packet from the MAC header */ 676 if (skb->data > skb_mac_header(skb)) 677 skb_push(skb, skb->data - skb_mac_header(skb)); 678 else 679 skb_pull(skb, skb_mac_header(skb) - skb->data); 680 681 /* Ensure packet fits inside a single netlink attribute */ 682 payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE); 683 if (net_dm_trunc_len) 684 payload_len = min_t(size_t, net_dm_trunc_len, payload_len); 685 686 msg = nlmsg_new(net_dm_packet_report_size(payload_len), GFP_KERNEL); 687 if (!msg) 688 goto out; 689 690 rc = net_dm_packet_report_fill(msg, skb, payload_len); 691 if (rc) { 692 nlmsg_free(msg); 693 goto out; 694 } 695 696 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL); 697 698 out: 699 consume_skb(skb); 700 } 701 702 static void net_dm_packet_work(struct work_struct *work) 703 { 704 struct per_cpu_dm_data *data; 705 struct sk_buff_head list; 706 struct sk_buff *skb; 707 unsigned long flags; 708 709 data = container_of(work, struct per_cpu_dm_data, dm_alert_work); 710 711 __skb_queue_head_init(&list); 712 713 spin_lock_irqsave(&data->drop_queue.lock, flags); 714 skb_queue_splice_tail_init(&data->drop_queue, &list); 715 spin_unlock_irqrestore(&data->drop_queue.lock, flags); 716 717 while ((skb = __skb_dequeue(&list))) 718 net_dm_packet_report(skb); 719 } 720 721 static size_t 722 net_dm_flow_action_cookie_size(const struct devlink_trap_metadata *hw_metadata) 723 { 724 return hw_metadata->fa_cookie ? 725 nla_total_size(hw_metadata->fa_cookie->cookie_len) : 0; 726 } 727 728 static size_t 729 net_dm_hw_packet_report_size(size_t payload_len, 730 const struct devlink_trap_metadata *hw_metadata) 731 { 732 size_t size; 733 734 size = nlmsg_msg_size(GENL_HDRLEN + net_drop_monitor_family.hdrsize); 735 736 return NLMSG_ALIGN(size) + 737 /* NET_DM_ATTR_ORIGIN */ 738 nla_total_size(sizeof(u16)) + 739 /* NET_DM_ATTR_HW_TRAP_GROUP_NAME */ 740 nla_total_size(strlen(hw_metadata->trap_group_name) + 1) + 741 /* NET_DM_ATTR_HW_TRAP_NAME */ 742 nla_total_size(strlen(hw_metadata->trap_name) + 1) + 743 /* NET_DM_ATTR_IN_PORT */ 744 net_dm_in_port_size() + 745 /* NET_DM_ATTR_FLOW_ACTION_COOKIE */ 746 net_dm_flow_action_cookie_size(hw_metadata) + 747 /* NET_DM_ATTR_TIMESTAMP */ 748 nla_total_size(sizeof(u64)) + 749 /* NET_DM_ATTR_ORIG_LEN */ 750 nla_total_size(sizeof(u32)) + 751 /* NET_DM_ATTR_PROTO */ 752 nla_total_size(sizeof(u16)) + 753 /* NET_DM_ATTR_PAYLOAD */ 754 nla_total_size(payload_len); 755 } 756 757 static int net_dm_hw_packet_report_fill(struct sk_buff *msg, 758 struct sk_buff *skb, size_t payload_len) 759 { 760 struct devlink_trap_metadata *hw_metadata; 761 struct nlattr *attr; 762 void *hdr; 763 764 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata; 765 766 hdr = genlmsg_put(msg, 0, 0, &net_drop_monitor_family, 0, 767 NET_DM_CMD_PACKET_ALERT); 768 if (!hdr) 769 return -EMSGSIZE; 770 771 if (nla_put_u16(msg, NET_DM_ATTR_ORIGIN, NET_DM_ORIGIN_HW)) 772 goto nla_put_failure; 773 774 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_GROUP_NAME, 775 hw_metadata->trap_group_name)) 776 goto nla_put_failure; 777 778 if (nla_put_string(msg, NET_DM_ATTR_HW_TRAP_NAME, 779 hw_metadata->trap_name)) 780 goto nla_put_failure; 781 782 if (hw_metadata->input_dev) { 783 struct net_device *dev = hw_metadata->input_dev; 784 int rc; 785 786 rc = net_dm_packet_report_in_port_put(msg, dev->ifindex, 787 dev->name); 788 if (rc) 789 goto nla_put_failure; 790 } 791 792 if (hw_metadata->fa_cookie && 793 nla_put(msg, NET_DM_ATTR_FLOW_ACTION_COOKIE, 794 hw_metadata->fa_cookie->cookie_len, 795 hw_metadata->fa_cookie->cookie)) 796 goto nla_put_failure; 797 798 if (nla_put_u64_64bit(msg, NET_DM_ATTR_TIMESTAMP, 799 ktime_to_ns(skb->tstamp), NET_DM_ATTR_PAD)) 800 goto nla_put_failure; 801 802 if (nla_put_u32(msg, NET_DM_ATTR_ORIG_LEN, skb->len)) 803 goto nla_put_failure; 804 805 if (!payload_len) 806 goto out; 807 808 if (nla_put_u16(msg, NET_DM_ATTR_PROTO, be16_to_cpu(skb->protocol))) 809 goto nla_put_failure; 810 811 attr = skb_put(msg, nla_total_size(payload_len)); 812 attr->nla_type = NET_DM_ATTR_PAYLOAD; 813 attr->nla_len = nla_attr_size(payload_len); 814 if (skb_copy_bits(skb, 0, nla_data(attr), payload_len)) 815 goto nla_put_failure; 816 817 out: 818 genlmsg_end(msg, hdr); 819 820 return 0; 821 822 nla_put_failure: 823 genlmsg_cancel(msg, hdr); 824 return -EMSGSIZE; 825 } 826 827 static struct devlink_trap_metadata * 828 net_dm_hw_metadata_copy(const struct devlink_trap_metadata *metadata) 829 { 830 const struct flow_action_cookie *fa_cookie; 831 struct devlink_trap_metadata *hw_metadata; 832 const char *trap_group_name; 833 const char *trap_name; 834 835 hw_metadata = kzalloc(sizeof(*hw_metadata), GFP_ATOMIC); 836 if (!hw_metadata) 837 return NULL; 838 839 trap_group_name = kstrdup(metadata->trap_group_name, GFP_ATOMIC); 840 if (!trap_group_name) 841 goto free_hw_metadata; 842 hw_metadata->trap_group_name = trap_group_name; 843 844 trap_name = kstrdup(metadata->trap_name, GFP_ATOMIC); 845 if (!trap_name) 846 goto free_trap_group; 847 hw_metadata->trap_name = trap_name; 848 849 if (metadata->fa_cookie) { 850 size_t cookie_size = sizeof(*fa_cookie) + 851 metadata->fa_cookie->cookie_len; 852 853 fa_cookie = kmemdup(metadata->fa_cookie, cookie_size, 854 GFP_ATOMIC); 855 if (!fa_cookie) 856 goto free_trap_name; 857 hw_metadata->fa_cookie = fa_cookie; 858 } 859 860 hw_metadata->input_dev = metadata->input_dev; 861 dev_hold_track(hw_metadata->input_dev, &hw_metadata->dev_tracker, GFP_ATOMIC); 862 863 return hw_metadata; 864 865 free_trap_name: 866 kfree(trap_name); 867 free_trap_group: 868 kfree(trap_group_name); 869 free_hw_metadata: 870 kfree(hw_metadata); 871 return NULL; 872 } 873 874 static void 875 net_dm_hw_metadata_free(struct devlink_trap_metadata *hw_metadata) 876 { 877 dev_put_track(hw_metadata->input_dev, &hw_metadata->dev_tracker); 878 kfree(hw_metadata->fa_cookie); 879 kfree(hw_metadata->trap_name); 880 kfree(hw_metadata->trap_group_name); 881 kfree(hw_metadata); 882 } 883 884 static void net_dm_hw_packet_report(struct sk_buff *skb) 885 { 886 struct devlink_trap_metadata *hw_metadata; 887 struct sk_buff *msg; 888 size_t payload_len; 889 int rc; 890 891 if (skb->data > skb_mac_header(skb)) 892 skb_push(skb, skb->data - skb_mac_header(skb)); 893 else 894 skb_pull(skb, skb_mac_header(skb) - skb->data); 895 896 payload_len = min_t(size_t, skb->len, NET_DM_MAX_PACKET_SIZE); 897 if (net_dm_trunc_len) 898 payload_len = min_t(size_t, net_dm_trunc_len, payload_len); 899 900 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata; 901 msg = nlmsg_new(net_dm_hw_packet_report_size(payload_len, hw_metadata), 902 GFP_KERNEL); 903 if (!msg) 904 goto out; 905 906 rc = net_dm_hw_packet_report_fill(msg, skb, payload_len); 907 if (rc) { 908 nlmsg_free(msg); 909 goto out; 910 } 911 912 genlmsg_multicast(&net_drop_monitor_family, msg, 0, 0, GFP_KERNEL); 913 914 out: 915 net_dm_hw_metadata_free(NET_DM_SKB_CB(skb)->hw_metadata); 916 consume_skb(skb); 917 } 918 919 static void net_dm_hw_packet_work(struct work_struct *work) 920 { 921 struct per_cpu_dm_data *hw_data; 922 struct sk_buff_head list; 923 struct sk_buff *skb; 924 unsigned long flags; 925 926 hw_data = container_of(work, struct per_cpu_dm_data, dm_alert_work); 927 928 __skb_queue_head_init(&list); 929 930 spin_lock_irqsave(&hw_data->drop_queue.lock, flags); 931 skb_queue_splice_tail_init(&hw_data->drop_queue, &list); 932 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags); 933 934 while ((skb = __skb_dequeue(&list))) 935 net_dm_hw_packet_report(skb); 936 } 937 938 static void 939 net_dm_hw_trap_packet_probe(void *ignore, const struct devlink *devlink, 940 struct sk_buff *skb, 941 const struct devlink_trap_metadata *metadata) 942 { 943 struct devlink_trap_metadata *n_hw_metadata; 944 ktime_t tstamp = ktime_get_real(); 945 struct per_cpu_dm_data *hw_data; 946 struct sk_buff *nskb; 947 unsigned long flags; 948 949 if (metadata->trap_type == DEVLINK_TRAP_TYPE_CONTROL) 950 return; 951 952 if (!skb_mac_header_was_set(skb)) 953 return; 954 955 nskb = skb_clone(skb, GFP_ATOMIC); 956 if (!nskb) 957 return; 958 959 n_hw_metadata = net_dm_hw_metadata_copy(metadata); 960 if (!n_hw_metadata) 961 goto free; 962 963 NET_DM_SKB_CB(nskb)->hw_metadata = n_hw_metadata; 964 nskb->tstamp = tstamp; 965 966 hw_data = this_cpu_ptr(&dm_hw_cpu_data); 967 968 spin_lock_irqsave(&hw_data->drop_queue.lock, flags); 969 if (skb_queue_len(&hw_data->drop_queue) < net_dm_queue_len) 970 __skb_queue_tail(&hw_data->drop_queue, nskb); 971 else 972 goto unlock_free; 973 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags); 974 975 schedule_work(&hw_data->dm_alert_work); 976 977 return; 978 979 unlock_free: 980 spin_unlock_irqrestore(&hw_data->drop_queue.lock, flags); 981 u64_stats_update_begin(&hw_data->stats.syncp); 982 hw_data->stats.dropped++; 983 u64_stats_update_end(&hw_data->stats.syncp); 984 net_dm_hw_metadata_free(n_hw_metadata); 985 free: 986 consume_skb(nskb); 987 } 988 989 static const struct net_dm_alert_ops net_dm_alert_packet_ops = { 990 .kfree_skb_probe = net_dm_packet_trace_kfree_skb_hit, 991 .napi_poll_probe = net_dm_packet_trace_napi_poll_hit, 992 .work_item_func = net_dm_packet_work, 993 .hw_work_item_func = net_dm_hw_packet_work, 994 .hw_trap_probe = net_dm_hw_trap_packet_probe, 995 }; 996 997 static const struct net_dm_alert_ops *net_dm_alert_ops_arr[] = { 998 [NET_DM_ALERT_MODE_SUMMARY] = &net_dm_alert_summary_ops, 999 [NET_DM_ALERT_MODE_PACKET] = &net_dm_alert_packet_ops, 1000 }; 1001 1002 #if IS_ENABLED(CONFIG_NET_DEVLINK) 1003 static int net_dm_hw_probe_register(const struct net_dm_alert_ops *ops) 1004 { 1005 return register_trace_devlink_trap_report(ops->hw_trap_probe, NULL); 1006 } 1007 1008 static void net_dm_hw_probe_unregister(const struct net_dm_alert_ops *ops) 1009 { 1010 unregister_trace_devlink_trap_report(ops->hw_trap_probe, NULL); 1011 tracepoint_synchronize_unregister(); 1012 } 1013 #else 1014 static int net_dm_hw_probe_register(const struct net_dm_alert_ops *ops) 1015 { 1016 return -EOPNOTSUPP; 1017 } 1018 1019 static void net_dm_hw_probe_unregister(const struct net_dm_alert_ops *ops) 1020 { 1021 } 1022 #endif 1023 1024 static int net_dm_hw_monitor_start(struct netlink_ext_ack *extack) 1025 { 1026 const struct net_dm_alert_ops *ops; 1027 int cpu, rc; 1028 1029 if (monitor_hw) { 1030 NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already enabled"); 1031 return -EAGAIN; 1032 } 1033 1034 ops = net_dm_alert_ops_arr[net_dm_alert_mode]; 1035 1036 if (!try_module_get(THIS_MODULE)) { 1037 NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module"); 1038 return -ENODEV; 1039 } 1040 1041 for_each_possible_cpu(cpu) { 1042 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu); 1043 struct net_dm_hw_entries *hw_entries; 1044 1045 INIT_WORK(&hw_data->dm_alert_work, ops->hw_work_item_func); 1046 timer_setup(&hw_data->send_timer, sched_send_work, 0); 1047 hw_entries = net_dm_hw_reset_per_cpu_data(hw_data); 1048 kfree(hw_entries); 1049 } 1050 1051 rc = net_dm_hw_probe_register(ops); 1052 if (rc) { 1053 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to devlink_trap_probe() tracepoint"); 1054 goto err_module_put; 1055 } 1056 1057 monitor_hw = true; 1058 1059 return 0; 1060 1061 err_module_put: 1062 for_each_possible_cpu(cpu) { 1063 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu); 1064 struct sk_buff *skb; 1065 1066 del_timer_sync(&hw_data->send_timer); 1067 cancel_work_sync(&hw_data->dm_alert_work); 1068 while ((skb = __skb_dequeue(&hw_data->drop_queue))) { 1069 struct devlink_trap_metadata *hw_metadata; 1070 1071 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata; 1072 net_dm_hw_metadata_free(hw_metadata); 1073 consume_skb(skb); 1074 } 1075 } 1076 module_put(THIS_MODULE); 1077 return rc; 1078 } 1079 1080 static void net_dm_hw_monitor_stop(struct netlink_ext_ack *extack) 1081 { 1082 const struct net_dm_alert_ops *ops; 1083 int cpu; 1084 1085 if (!monitor_hw) { 1086 NL_SET_ERR_MSG_MOD(extack, "Hardware monitoring already disabled"); 1087 return; 1088 } 1089 1090 ops = net_dm_alert_ops_arr[net_dm_alert_mode]; 1091 1092 monitor_hw = false; 1093 1094 net_dm_hw_probe_unregister(ops); 1095 1096 for_each_possible_cpu(cpu) { 1097 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu); 1098 struct sk_buff *skb; 1099 1100 del_timer_sync(&hw_data->send_timer); 1101 cancel_work_sync(&hw_data->dm_alert_work); 1102 while ((skb = __skb_dequeue(&hw_data->drop_queue))) { 1103 struct devlink_trap_metadata *hw_metadata; 1104 1105 hw_metadata = NET_DM_SKB_CB(skb)->hw_metadata; 1106 net_dm_hw_metadata_free(hw_metadata); 1107 consume_skb(skb); 1108 } 1109 } 1110 1111 module_put(THIS_MODULE); 1112 } 1113 1114 static int net_dm_trace_on_set(struct netlink_ext_ack *extack) 1115 { 1116 const struct net_dm_alert_ops *ops; 1117 int cpu, rc; 1118 1119 ops = net_dm_alert_ops_arr[net_dm_alert_mode]; 1120 1121 if (!try_module_get(THIS_MODULE)) { 1122 NL_SET_ERR_MSG_MOD(extack, "Failed to take reference on module"); 1123 return -ENODEV; 1124 } 1125 1126 for_each_possible_cpu(cpu) { 1127 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu); 1128 struct sk_buff *skb; 1129 1130 INIT_WORK(&data->dm_alert_work, ops->work_item_func); 1131 timer_setup(&data->send_timer, sched_send_work, 0); 1132 /* Allocate a new per-CPU skb for the summary alert message and 1133 * free the old one which might contain stale data from 1134 * previous tracing. 1135 */ 1136 skb = reset_per_cpu_data(data); 1137 consume_skb(skb); 1138 } 1139 1140 rc = register_trace_kfree_skb(ops->kfree_skb_probe, NULL); 1141 if (rc) { 1142 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to kfree_skb() tracepoint"); 1143 goto err_module_put; 1144 } 1145 1146 rc = register_trace_napi_poll(ops->napi_poll_probe, NULL); 1147 if (rc) { 1148 NL_SET_ERR_MSG_MOD(extack, "Failed to connect probe to napi_poll() tracepoint"); 1149 goto err_unregister_trace; 1150 } 1151 1152 return 0; 1153 1154 err_unregister_trace: 1155 unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL); 1156 err_module_put: 1157 for_each_possible_cpu(cpu) { 1158 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu); 1159 struct sk_buff *skb; 1160 1161 del_timer_sync(&data->send_timer); 1162 cancel_work_sync(&data->dm_alert_work); 1163 while ((skb = __skb_dequeue(&data->drop_queue))) 1164 consume_skb(skb); 1165 } 1166 module_put(THIS_MODULE); 1167 return rc; 1168 } 1169 1170 static void net_dm_trace_off_set(void) 1171 { 1172 struct dm_hw_stat_delta *new_stat, *temp; 1173 const struct net_dm_alert_ops *ops; 1174 int cpu; 1175 1176 ops = net_dm_alert_ops_arr[net_dm_alert_mode]; 1177 1178 unregister_trace_napi_poll(ops->napi_poll_probe, NULL); 1179 unregister_trace_kfree_skb(ops->kfree_skb_probe, NULL); 1180 1181 tracepoint_synchronize_unregister(); 1182 1183 /* Make sure we do not send notifications to user space after request 1184 * to stop tracing returns. 1185 */ 1186 for_each_possible_cpu(cpu) { 1187 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu); 1188 struct sk_buff *skb; 1189 1190 del_timer_sync(&data->send_timer); 1191 cancel_work_sync(&data->dm_alert_work); 1192 while ((skb = __skb_dequeue(&data->drop_queue))) 1193 consume_skb(skb); 1194 } 1195 1196 list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) { 1197 if (new_stat->dev == NULL) { 1198 list_del_rcu(&new_stat->list); 1199 kfree_rcu(new_stat, rcu); 1200 } 1201 } 1202 1203 module_put(THIS_MODULE); 1204 } 1205 1206 static int set_all_monitor_traces(int state, struct netlink_ext_ack *extack) 1207 { 1208 int rc = 0; 1209 1210 if (state == trace_state) { 1211 NL_SET_ERR_MSG_MOD(extack, "Trace state already set to requested state"); 1212 return -EAGAIN; 1213 } 1214 1215 switch (state) { 1216 case TRACE_ON: 1217 rc = net_dm_trace_on_set(extack); 1218 break; 1219 case TRACE_OFF: 1220 net_dm_trace_off_set(); 1221 break; 1222 default: 1223 rc = 1; 1224 break; 1225 } 1226 1227 if (!rc) 1228 trace_state = state; 1229 else 1230 rc = -EINPROGRESS; 1231 1232 return rc; 1233 } 1234 1235 static bool net_dm_is_monitoring(void) 1236 { 1237 return trace_state == TRACE_ON || monitor_hw; 1238 } 1239 1240 static int net_dm_alert_mode_get_from_info(struct genl_info *info, 1241 enum net_dm_alert_mode *p_alert_mode) 1242 { 1243 u8 val; 1244 1245 val = nla_get_u8(info->attrs[NET_DM_ATTR_ALERT_MODE]); 1246 1247 switch (val) { 1248 case NET_DM_ALERT_MODE_SUMMARY: 1249 case NET_DM_ALERT_MODE_PACKET: 1250 *p_alert_mode = val; 1251 break; 1252 default: 1253 return -EINVAL; 1254 } 1255 1256 return 0; 1257 } 1258 1259 static int net_dm_alert_mode_set(struct genl_info *info) 1260 { 1261 struct netlink_ext_ack *extack = info->extack; 1262 enum net_dm_alert_mode alert_mode; 1263 int rc; 1264 1265 if (!info->attrs[NET_DM_ATTR_ALERT_MODE]) 1266 return 0; 1267 1268 rc = net_dm_alert_mode_get_from_info(info, &alert_mode); 1269 if (rc) { 1270 NL_SET_ERR_MSG_MOD(extack, "Invalid alert mode"); 1271 return -EINVAL; 1272 } 1273 1274 net_dm_alert_mode = alert_mode; 1275 1276 return 0; 1277 } 1278 1279 static void net_dm_trunc_len_set(struct genl_info *info) 1280 { 1281 if (!info->attrs[NET_DM_ATTR_TRUNC_LEN]) 1282 return; 1283 1284 net_dm_trunc_len = nla_get_u32(info->attrs[NET_DM_ATTR_TRUNC_LEN]); 1285 } 1286 1287 static void net_dm_queue_len_set(struct genl_info *info) 1288 { 1289 if (!info->attrs[NET_DM_ATTR_QUEUE_LEN]) 1290 return; 1291 1292 net_dm_queue_len = nla_get_u32(info->attrs[NET_DM_ATTR_QUEUE_LEN]); 1293 } 1294 1295 static int net_dm_cmd_config(struct sk_buff *skb, 1296 struct genl_info *info) 1297 { 1298 struct netlink_ext_ack *extack = info->extack; 1299 int rc; 1300 1301 if (net_dm_is_monitoring()) { 1302 NL_SET_ERR_MSG_MOD(extack, "Cannot configure drop monitor during monitoring"); 1303 return -EBUSY; 1304 } 1305 1306 rc = net_dm_alert_mode_set(info); 1307 if (rc) 1308 return rc; 1309 1310 net_dm_trunc_len_set(info); 1311 1312 net_dm_queue_len_set(info); 1313 1314 return 0; 1315 } 1316 1317 static int net_dm_monitor_start(bool set_sw, bool set_hw, 1318 struct netlink_ext_ack *extack) 1319 { 1320 bool sw_set = false; 1321 int rc; 1322 1323 if (set_sw) { 1324 rc = set_all_monitor_traces(TRACE_ON, extack); 1325 if (rc) 1326 return rc; 1327 sw_set = true; 1328 } 1329 1330 if (set_hw) { 1331 rc = net_dm_hw_monitor_start(extack); 1332 if (rc) 1333 goto err_monitor_hw; 1334 } 1335 1336 return 0; 1337 1338 err_monitor_hw: 1339 if (sw_set) 1340 set_all_monitor_traces(TRACE_OFF, extack); 1341 return rc; 1342 } 1343 1344 static void net_dm_monitor_stop(bool set_sw, bool set_hw, 1345 struct netlink_ext_ack *extack) 1346 { 1347 if (set_hw) 1348 net_dm_hw_monitor_stop(extack); 1349 if (set_sw) 1350 set_all_monitor_traces(TRACE_OFF, extack); 1351 } 1352 1353 static int net_dm_cmd_trace(struct sk_buff *skb, 1354 struct genl_info *info) 1355 { 1356 bool set_sw = !!info->attrs[NET_DM_ATTR_SW_DROPS]; 1357 bool set_hw = !!info->attrs[NET_DM_ATTR_HW_DROPS]; 1358 struct netlink_ext_ack *extack = info->extack; 1359 1360 /* To maintain backward compatibility, we start / stop monitoring of 1361 * software drops if no flag is specified. 1362 */ 1363 if (!set_sw && !set_hw) 1364 set_sw = true; 1365 1366 switch (info->genlhdr->cmd) { 1367 case NET_DM_CMD_START: 1368 return net_dm_monitor_start(set_sw, set_hw, extack); 1369 case NET_DM_CMD_STOP: 1370 net_dm_monitor_stop(set_sw, set_hw, extack); 1371 return 0; 1372 } 1373 1374 return -EOPNOTSUPP; 1375 } 1376 1377 static int net_dm_config_fill(struct sk_buff *msg, struct genl_info *info) 1378 { 1379 void *hdr; 1380 1381 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq, 1382 &net_drop_monitor_family, 0, NET_DM_CMD_CONFIG_NEW); 1383 if (!hdr) 1384 return -EMSGSIZE; 1385 1386 if (nla_put_u8(msg, NET_DM_ATTR_ALERT_MODE, net_dm_alert_mode)) 1387 goto nla_put_failure; 1388 1389 if (nla_put_u32(msg, NET_DM_ATTR_TRUNC_LEN, net_dm_trunc_len)) 1390 goto nla_put_failure; 1391 1392 if (nla_put_u32(msg, NET_DM_ATTR_QUEUE_LEN, net_dm_queue_len)) 1393 goto nla_put_failure; 1394 1395 genlmsg_end(msg, hdr); 1396 1397 return 0; 1398 1399 nla_put_failure: 1400 genlmsg_cancel(msg, hdr); 1401 return -EMSGSIZE; 1402 } 1403 1404 static int net_dm_cmd_config_get(struct sk_buff *skb, struct genl_info *info) 1405 { 1406 struct sk_buff *msg; 1407 int rc; 1408 1409 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 1410 if (!msg) 1411 return -ENOMEM; 1412 1413 rc = net_dm_config_fill(msg, info); 1414 if (rc) 1415 goto free_msg; 1416 1417 return genlmsg_reply(msg, info); 1418 1419 free_msg: 1420 nlmsg_free(msg); 1421 return rc; 1422 } 1423 1424 static void net_dm_stats_read(struct net_dm_stats *stats) 1425 { 1426 int cpu; 1427 1428 memset(stats, 0, sizeof(*stats)); 1429 for_each_possible_cpu(cpu) { 1430 struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu); 1431 struct net_dm_stats *cpu_stats = &data->stats; 1432 unsigned int start; 1433 u64 dropped; 1434 1435 do { 1436 start = u64_stats_fetch_begin_irq(&cpu_stats->syncp); 1437 dropped = cpu_stats->dropped; 1438 } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start)); 1439 1440 stats->dropped += dropped; 1441 } 1442 } 1443 1444 static int net_dm_stats_put(struct sk_buff *msg) 1445 { 1446 struct net_dm_stats stats; 1447 struct nlattr *attr; 1448 1449 net_dm_stats_read(&stats); 1450 1451 attr = nla_nest_start(msg, NET_DM_ATTR_STATS); 1452 if (!attr) 1453 return -EMSGSIZE; 1454 1455 if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED, 1456 stats.dropped, NET_DM_ATTR_PAD)) 1457 goto nla_put_failure; 1458 1459 nla_nest_end(msg, attr); 1460 1461 return 0; 1462 1463 nla_put_failure: 1464 nla_nest_cancel(msg, attr); 1465 return -EMSGSIZE; 1466 } 1467 1468 static void net_dm_hw_stats_read(struct net_dm_stats *stats) 1469 { 1470 int cpu; 1471 1472 memset(stats, 0, sizeof(*stats)); 1473 for_each_possible_cpu(cpu) { 1474 struct per_cpu_dm_data *hw_data = &per_cpu(dm_hw_cpu_data, cpu); 1475 struct net_dm_stats *cpu_stats = &hw_data->stats; 1476 unsigned int start; 1477 u64 dropped; 1478 1479 do { 1480 start = u64_stats_fetch_begin_irq(&cpu_stats->syncp); 1481 dropped = cpu_stats->dropped; 1482 } while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start)); 1483 1484 stats->dropped += dropped; 1485 } 1486 } 1487 1488 static int net_dm_hw_stats_put(struct sk_buff *msg) 1489 { 1490 struct net_dm_stats stats; 1491 struct nlattr *attr; 1492 1493 net_dm_hw_stats_read(&stats); 1494 1495 attr = nla_nest_start(msg, NET_DM_ATTR_HW_STATS); 1496 if (!attr) 1497 return -EMSGSIZE; 1498 1499 if (nla_put_u64_64bit(msg, NET_DM_ATTR_STATS_DROPPED, 1500 stats.dropped, NET_DM_ATTR_PAD)) 1501 goto nla_put_failure; 1502 1503 nla_nest_end(msg, attr); 1504 1505 return 0; 1506 1507 nla_put_failure: 1508 nla_nest_cancel(msg, attr); 1509 return -EMSGSIZE; 1510 } 1511 1512 static int net_dm_stats_fill(struct sk_buff *msg, struct genl_info *info) 1513 { 1514 void *hdr; 1515 int rc; 1516 1517 hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq, 1518 &net_drop_monitor_family, 0, NET_DM_CMD_STATS_NEW); 1519 if (!hdr) 1520 return -EMSGSIZE; 1521 1522 rc = net_dm_stats_put(msg); 1523 if (rc) 1524 goto nla_put_failure; 1525 1526 rc = net_dm_hw_stats_put(msg); 1527 if (rc) 1528 goto nla_put_failure; 1529 1530 genlmsg_end(msg, hdr); 1531 1532 return 0; 1533 1534 nla_put_failure: 1535 genlmsg_cancel(msg, hdr); 1536 return -EMSGSIZE; 1537 } 1538 1539 static int net_dm_cmd_stats_get(struct sk_buff *skb, struct genl_info *info) 1540 { 1541 struct sk_buff *msg; 1542 int rc; 1543 1544 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 1545 if (!msg) 1546 return -ENOMEM; 1547 1548 rc = net_dm_stats_fill(msg, info); 1549 if (rc) 1550 goto free_msg; 1551 1552 return genlmsg_reply(msg, info); 1553 1554 free_msg: 1555 nlmsg_free(msg); 1556 return rc; 1557 } 1558 1559 static int dropmon_net_event(struct notifier_block *ev_block, 1560 unsigned long event, void *ptr) 1561 { 1562 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1563 struct dm_hw_stat_delta *new_stat = NULL; 1564 struct dm_hw_stat_delta *tmp; 1565 1566 switch (event) { 1567 case NETDEV_REGISTER: 1568 new_stat = kzalloc(sizeof(struct dm_hw_stat_delta), GFP_KERNEL); 1569 1570 if (!new_stat) 1571 goto out; 1572 1573 new_stat->dev = dev; 1574 new_stat->last_rx = jiffies; 1575 mutex_lock(&net_dm_mutex); 1576 list_add_rcu(&new_stat->list, &hw_stats_list); 1577 mutex_unlock(&net_dm_mutex); 1578 break; 1579 case NETDEV_UNREGISTER: 1580 mutex_lock(&net_dm_mutex); 1581 list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) { 1582 if (new_stat->dev == dev) { 1583 1584 /* Paired with READ_ONCE() in trace_napi_poll_hit() */ 1585 WRITE_ONCE(new_stat->dev, NULL); 1586 1587 if (trace_state == TRACE_OFF) { 1588 list_del_rcu(&new_stat->list); 1589 kfree_rcu(new_stat, rcu); 1590 break; 1591 } 1592 } 1593 } 1594 mutex_unlock(&net_dm_mutex); 1595 break; 1596 } 1597 out: 1598 return NOTIFY_DONE; 1599 } 1600 1601 static const struct nla_policy net_dm_nl_policy[NET_DM_ATTR_MAX + 1] = { 1602 [NET_DM_ATTR_UNSPEC] = { .strict_start_type = NET_DM_ATTR_UNSPEC + 1 }, 1603 [NET_DM_ATTR_ALERT_MODE] = { .type = NLA_U8 }, 1604 [NET_DM_ATTR_TRUNC_LEN] = { .type = NLA_U32 }, 1605 [NET_DM_ATTR_QUEUE_LEN] = { .type = NLA_U32 }, 1606 [NET_DM_ATTR_SW_DROPS] = {. type = NLA_FLAG }, 1607 [NET_DM_ATTR_HW_DROPS] = {. type = NLA_FLAG }, 1608 }; 1609 1610 static const struct genl_small_ops dropmon_ops[] = { 1611 { 1612 .cmd = NET_DM_CMD_CONFIG, 1613 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1614 .doit = net_dm_cmd_config, 1615 .flags = GENL_ADMIN_PERM, 1616 }, 1617 { 1618 .cmd = NET_DM_CMD_START, 1619 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1620 .doit = net_dm_cmd_trace, 1621 }, 1622 { 1623 .cmd = NET_DM_CMD_STOP, 1624 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, 1625 .doit = net_dm_cmd_trace, 1626 }, 1627 { 1628 .cmd = NET_DM_CMD_CONFIG_GET, 1629 .doit = net_dm_cmd_config_get, 1630 }, 1631 { 1632 .cmd = NET_DM_CMD_STATS_GET, 1633 .doit = net_dm_cmd_stats_get, 1634 }, 1635 }; 1636 1637 static int net_dm_nl_pre_doit(const struct genl_ops *ops, 1638 struct sk_buff *skb, struct genl_info *info) 1639 { 1640 mutex_lock(&net_dm_mutex); 1641 1642 return 0; 1643 } 1644 1645 static void net_dm_nl_post_doit(const struct genl_ops *ops, 1646 struct sk_buff *skb, struct genl_info *info) 1647 { 1648 mutex_unlock(&net_dm_mutex); 1649 } 1650 1651 static struct genl_family net_drop_monitor_family __ro_after_init = { 1652 .hdrsize = 0, 1653 .name = "NET_DM", 1654 .version = 2, 1655 .maxattr = NET_DM_ATTR_MAX, 1656 .policy = net_dm_nl_policy, 1657 .pre_doit = net_dm_nl_pre_doit, 1658 .post_doit = net_dm_nl_post_doit, 1659 .module = THIS_MODULE, 1660 .small_ops = dropmon_ops, 1661 .n_small_ops = ARRAY_SIZE(dropmon_ops), 1662 .mcgrps = dropmon_mcgrps, 1663 .n_mcgrps = ARRAY_SIZE(dropmon_mcgrps), 1664 }; 1665 1666 static struct notifier_block dropmon_net_notifier = { 1667 .notifier_call = dropmon_net_event 1668 }; 1669 1670 static void __net_dm_cpu_data_init(struct per_cpu_dm_data *data) 1671 { 1672 spin_lock_init(&data->lock); 1673 skb_queue_head_init(&data->drop_queue); 1674 u64_stats_init(&data->stats.syncp); 1675 } 1676 1677 static void __net_dm_cpu_data_fini(struct per_cpu_dm_data *data) 1678 { 1679 WARN_ON(!skb_queue_empty(&data->drop_queue)); 1680 } 1681 1682 static void net_dm_cpu_data_init(int cpu) 1683 { 1684 struct per_cpu_dm_data *data; 1685 1686 data = &per_cpu(dm_cpu_data, cpu); 1687 __net_dm_cpu_data_init(data); 1688 } 1689 1690 static void net_dm_cpu_data_fini(int cpu) 1691 { 1692 struct per_cpu_dm_data *data; 1693 1694 data = &per_cpu(dm_cpu_data, cpu); 1695 /* At this point, we should have exclusive access 1696 * to this struct and can free the skb inside it. 1697 */ 1698 consume_skb(data->skb); 1699 __net_dm_cpu_data_fini(data); 1700 } 1701 1702 static void net_dm_hw_cpu_data_init(int cpu) 1703 { 1704 struct per_cpu_dm_data *hw_data; 1705 1706 hw_data = &per_cpu(dm_hw_cpu_data, cpu); 1707 __net_dm_cpu_data_init(hw_data); 1708 } 1709 1710 static void net_dm_hw_cpu_data_fini(int cpu) 1711 { 1712 struct per_cpu_dm_data *hw_data; 1713 1714 hw_data = &per_cpu(dm_hw_cpu_data, cpu); 1715 kfree(hw_data->hw_entries); 1716 __net_dm_cpu_data_fini(hw_data); 1717 } 1718 1719 static int __init init_net_drop_monitor(void) 1720 { 1721 int cpu, rc; 1722 1723 pr_info("Initializing network drop monitor service\n"); 1724 1725 if (sizeof(void *) > 8) { 1726 pr_err("Unable to store program counters on this arch, Drop monitor failed\n"); 1727 return -ENOSPC; 1728 } 1729 1730 rc = genl_register_family(&net_drop_monitor_family); 1731 if (rc) { 1732 pr_err("Could not create drop monitor netlink family\n"); 1733 return rc; 1734 } 1735 WARN_ON(net_drop_monitor_family.mcgrp_offset != NET_DM_GRP_ALERT); 1736 1737 rc = register_netdevice_notifier(&dropmon_net_notifier); 1738 if (rc < 0) { 1739 pr_crit("Failed to register netdevice notifier\n"); 1740 goto out_unreg; 1741 } 1742 1743 rc = 0; 1744 1745 for_each_possible_cpu(cpu) { 1746 net_dm_cpu_data_init(cpu); 1747 net_dm_hw_cpu_data_init(cpu); 1748 } 1749 1750 goto out; 1751 1752 out_unreg: 1753 genl_unregister_family(&net_drop_monitor_family); 1754 out: 1755 return rc; 1756 } 1757 1758 static void exit_net_drop_monitor(void) 1759 { 1760 int cpu; 1761 1762 BUG_ON(unregister_netdevice_notifier(&dropmon_net_notifier)); 1763 1764 /* 1765 * Because of the module_get/put we do in the trace state change path 1766 * we are guaranteed not to have any current users when we get here 1767 */ 1768 1769 for_each_possible_cpu(cpu) { 1770 net_dm_hw_cpu_data_fini(cpu); 1771 net_dm_cpu_data_fini(cpu); 1772 } 1773 1774 BUG_ON(genl_unregister_family(&net_drop_monitor_family)); 1775 } 1776 1777 module_init(init_net_drop_monitor); 1778 module_exit(exit_net_drop_monitor); 1779 1780 MODULE_LICENSE("GPL v2"); 1781 MODULE_AUTHOR("Neil Horman <nhorman@tuxdriver.com>"); 1782 MODULE_ALIAS_GENL_FAMILY("NET_DM"); 1783 MODULE_DESCRIPTION("Monitoring code for network dropped packet alerts"); 1784