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