1/*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2007-2009 5 * Swinburne University of Technology, Melbourne, Australia. 6 * Copyright (c) 2009-2010, The FreeBSD Foundation 7 * All rights reserved. 8 * 9 * Portions of this software were developed at the Centre for Advanced 10 * Internet Architectures, Swinburne University of Technology, Melbourne, 11 * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35/****************************************************** 36 * Statistical Information For TCP Research (SIFTR) 37 * 38 * A FreeBSD kernel module that adds very basic intrumentation to the 39 * TCP stack, allowing internal stats to be recorded to a log file 40 * for experimental, debugging and performance analysis purposes. 41 * 42 * SIFTR was first released in 2007 by James Healy and Lawrence Stewart whilst 43 * working on the NewTCP research project at Swinburne University of 44 * Technology's Centre for Advanced Internet Architectures, Melbourne, 45 * Australia, which was made possible in part by a grant from the Cisco 46 * University Research Program Fund at Community Foundation Silicon Valley. 47 * More details are available at: 48 * http://caia.swin.edu.au/urp/newtcp/ 49 * 50 * Work on SIFTR v1.2.x was sponsored by the FreeBSD Foundation as part of 51 * the "Enhancing the FreeBSD TCP Implementation" project 2008-2009. 52 * More details are available at: 53 * http://www.freebsdfoundation.org/ 54 * http://caia.swin.edu.au/freebsd/etcp09/ 55 * 56 * Lawrence Stewart is the current maintainer, and all contact regarding 57 * SIFTR should be directed to him via email: lastewart@swin.edu.au 58 * 59 * Initial release date: June 2007 60 * Most recent update: September 2010 61 ******************************************************/ 62 63#include <sys/cdefs.h> 64__FBSDID("$FreeBSD$"); 65 66#include <sys/param.h> 67#include <sys/alq.h> 68#include <sys/errno.h> 69#include <sys/eventhandler.h> 70#include <sys/hash.h> 71#include <sys/kernel.h> 72#include <sys/kthread.h> 73#include <sys/lock.h> 74#include <sys/mbuf.h> 75#include <sys/module.h> 76#include <sys/mutex.h> 77#include <sys/pcpu.h> 78#include <sys/proc.h> 79#include <sys/sbuf.h> 80#include <sys/sdt.h> 81#include <sys/smp.h> 82#include <sys/socket.h> 83#include <sys/socketvar.h> 84#include <sys/sysctl.h> 85#include <sys/unistd.h> 86 87#include <net/if.h> 88#include <net/if_var.h> 89#include <net/pfil.h> 90 91#include <netinet/in.h> 92#include <netinet/in_kdtrace.h> 93#include <netinet/in_pcb.h> 94#include <netinet/in_systm.h> 95#include <netinet/in_var.h> 96#include <netinet/ip.h> 97#include <netinet/tcp_var.h> 98 99#ifdef SIFTR_IPV6 100#include <netinet/ip6.h> 101#include <netinet6/in6_pcb.h> 102#endif /* SIFTR_IPV6 */ 103 104#include <machine/in_cksum.h> 105 106/* 107 * Three digit version number refers to X.Y.Z where: 108 * X is the major version number 109 * Y is bumped to mark backwards incompatible changes 110 * Z is bumped to mark backwards compatible changes 111 */ 112#define V_MAJOR 1 113#define V_BACKBREAK 2 114#define V_BACKCOMPAT 4 115#define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT)) 116#define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \ 117 __XSTRING(V_BACKCOMPAT) 118 119#define HOOK 0 120#define UNHOOK 1 121#define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536 122#define SYS_NAME "FreeBSD" 123#define PACKET_TAG_SIFTR 100 124#define PACKET_COOKIE_SIFTR 21749576 125#define SIFTR_LOG_FILE_MODE 0644 126#define SIFTR_DISABLE 0 127#define SIFTR_ENABLE 1 128 129/* 130 * Hard upper limit on the length of log messages. Bump this up if you add new 131 * data fields such that the line length could exceed the below value. 132 */ 133#define MAX_LOG_MSG_LEN 200 134/* XXX: Make this a sysctl tunable. */ 135#define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN) 136 137/* 138 * 1 byte for IP version 139 * IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes 140 * IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes 141 */ 142#ifdef SIFTR_IPV6 143#define FLOW_KEY_LEN 37 144#else 145#define FLOW_KEY_LEN 13 146#endif 147 148#ifdef SIFTR_IPV6 149#define SIFTR_IPMODE 6 150#else 151#define SIFTR_IPMODE 4 152#endif 153 154/* useful macros */ 155#define UPPER_SHORT(X) (((X) & 0xFFFF0000) >> 16) 156#define LOWER_SHORT(X) ((X) & 0x0000FFFF) 157 158#define FIRST_OCTET(X) (((X) & 0xFF000000) >> 24) 159#define SECOND_OCTET(X) (((X) & 0x00FF0000) >> 16) 160#define THIRD_OCTET(X) (((X) & 0x0000FF00) >> 8) 161#define FOURTH_OCTET(X) ((X) & 0x000000FF) 162 163static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR"); 164static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode", 165 "SIFTR pkt_node struct"); 166static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode", 167 "SIFTR flow_hash_node struct"); 168 169/* Used as links in the pkt manager queue. */ 170struct pkt_node { 171 /* Timestamp of pkt as noted in the pfil hook. */ 172 struct timeval tval; 173 /* Direction pkt is travelling; either PFIL_IN or PFIL_OUT. */ 174 uint8_t direction; 175 /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */ 176 uint8_t ipver; 177 /* Hash of the pkt which triggered the log message. */ 178 uint32_t hash; 179 /* Local/foreign IP address. */ 180#ifdef SIFTR_IPV6 181 uint32_t ip_laddr[4]; 182 uint32_t ip_faddr[4]; 183#else 184 uint8_t ip_laddr[4]; 185 uint8_t ip_faddr[4]; 186#endif 187 /* Local TCP port. */ 188 uint16_t tcp_localport; 189 /* Foreign TCP port. */ 190 uint16_t tcp_foreignport; 191 /* Congestion Window (bytes). */ 192 u_long snd_cwnd; 193 /* Sending Window (bytes). */ 194 u_long snd_wnd; 195 /* Receive Window (bytes). */ 196 u_long rcv_wnd; 197 /* Unused (was: Bandwidth Controlled Window (bytes)). */ 198 u_long snd_bwnd; 199 /* Slow Start Threshold (bytes). */ 200 u_long snd_ssthresh; 201 /* Current state of the TCP FSM. */ 202 int conn_state; 203 /* Max Segment Size (bytes). */ 204 u_int max_seg_size; 205 /* 206 * Smoothed RTT stored as found in the TCP control block 207 * in units of (TCP_RTT_SCALE*hz). 208 */ 209 int smoothed_rtt; 210 /* Is SACK enabled? */ 211 u_char sack_enabled; 212 /* Window scaling for snd window. */ 213 u_char snd_scale; 214 /* Window scaling for recv window. */ 215 u_char rcv_scale; 216 /* TCP control block flags. */ 217 u_int flags; 218 /* Retransmit timeout length. */ 219 int rxt_length; 220 /* Size of the TCP send buffer in bytes. */ 221 u_int snd_buf_hiwater; 222 /* Current num bytes in the send socket buffer. */ 223 u_int snd_buf_cc; 224 /* Size of the TCP receive buffer in bytes. */ 225 u_int rcv_buf_hiwater; 226 /* Current num bytes in the receive socket buffer. */ 227 u_int rcv_buf_cc; 228 /* Number of bytes inflight that we are waiting on ACKs for. */ 229 u_int sent_inflight_bytes; 230 /* Number of segments currently in the reassembly queue. */ 231 int t_segqlen; 232 /* Flowid for the connection. */ 233 u_int flowid; 234 /* Flow type for the connection. */ 235 u_int flowtype; 236 /* Link to next pkt_node in the list. */ 237 STAILQ_ENTRY(pkt_node) nodes; 238}; 239 240struct flow_hash_node 241{ 242 uint16_t counter; 243 uint8_t key[FLOW_KEY_LEN]; 244 LIST_ENTRY(flow_hash_node) nodes; 245}; 246 247struct siftr_stats 248{ 249 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */ 250 uint64_t n_in; 251 uint64_t n_out; 252 /* # pkts skipped due to failed malloc calls. */ 253 uint32_t nskip_in_malloc; 254 uint32_t nskip_out_malloc; 255 /* # pkts skipped due to failed mtx acquisition. */ 256 uint32_t nskip_in_mtx; 257 uint32_t nskip_out_mtx; 258 /* # pkts skipped due to failed inpcb lookups. */ 259 uint32_t nskip_in_inpcb; 260 uint32_t nskip_out_inpcb; 261 /* # pkts skipped due to failed tcpcb lookups. */ 262 uint32_t nskip_in_tcpcb; 263 uint32_t nskip_out_tcpcb; 264 /* # pkts skipped due to stack reinjection. */ 265 uint32_t nskip_in_dejavu; 266 uint32_t nskip_out_dejavu; 267}; 268 269DPCPU_DEFINE_STATIC(struct siftr_stats, ss); 270 271static volatile unsigned int siftr_exit_pkt_manager_thread = 0; 272static unsigned int siftr_enabled = 0; 273static unsigned int siftr_pkts_per_log = 1; 274static unsigned int siftr_generate_hashes = 0; 275static uint16_t siftr_port_filter = 0; 276/* static unsigned int siftr_binary_log = 0; */ 277static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log"; 278static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log"; 279static u_long siftr_hashmask; 280STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue); 281LIST_HEAD(listhead, flow_hash_node) *counter_hash; 282static int wait_for_pkt; 283static struct alq *siftr_alq = NULL; 284static struct mtx siftr_pkt_queue_mtx; 285static struct mtx siftr_pkt_mgr_mtx; 286static struct thread *siftr_pkt_manager_thr = NULL; 287/* 288 * pfil.h defines PFIL_IN as 1 and PFIL_OUT as 2, 289 * which we use as an index into this array. 290 */ 291static char direction[3] = {'\0', 'i','o'}; 292 293/* Required function prototypes. */ 294static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS); 295static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS); 296 297 298/* Declare the net.inet.siftr sysctl tree and populate it. */ 299 300SYSCTL_DECL(_net_inet_siftr); 301 302SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW, NULL, 303 "siftr related settings"); 304 305SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, CTLTYPE_UINT|CTLFLAG_RW, 306 &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU", 307 "switch siftr module operations on/off"); 308 309SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, CTLTYPE_STRING|CTLFLAG_RW, 310 &siftr_logfile_shadow, sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler, 311 "A", "file to save siftr log messages to"); 312 313SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW, 314 &siftr_pkts_per_log, 1, 315 "number of packets between generating a log message"); 316 317SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW, 318 &siftr_generate_hashes, 0, 319 "enable packet hash generation"); 320 321SYSCTL_U16(_net_inet_siftr, OID_AUTO, port_filter, CTLFLAG_RW, 322 &siftr_port_filter, 0, 323 "enable packet filter on a TCP port"); 324 325/* XXX: TODO 326SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW, 327 &siftr_binary_log, 0, 328 "write log files in binary instead of ascii"); 329*/ 330 331 332/* Begin functions. */ 333 334static void 335siftr_process_pkt(struct pkt_node * pkt_node) 336{ 337 struct flow_hash_node *hash_node; 338 struct listhead *counter_list; 339 struct siftr_stats *ss; 340 struct ale *log_buf; 341 uint8_t key[FLOW_KEY_LEN]; 342 uint8_t found_match, key_offset; 343 344 hash_node = NULL; 345 ss = DPCPU_PTR(ss); 346 found_match = 0; 347 key_offset = 1; 348 349 /* 350 * Create the key that will be used to create a hash index 351 * into our hash table. Our key consists of: 352 * ipversion, localip, localport, foreignip, foreignport 353 */ 354 key[0] = pkt_node->ipver; 355 memcpy(key + key_offset, &pkt_node->ip_laddr, 356 sizeof(pkt_node->ip_laddr)); 357 key_offset += sizeof(pkt_node->ip_laddr); 358 memcpy(key + key_offset, &pkt_node->tcp_localport, 359 sizeof(pkt_node->tcp_localport)); 360 key_offset += sizeof(pkt_node->tcp_localport); 361 memcpy(key + key_offset, &pkt_node->ip_faddr, 362 sizeof(pkt_node->ip_faddr)); 363 key_offset += sizeof(pkt_node->ip_faddr); 364 memcpy(key + key_offset, &pkt_node->tcp_foreignport, 365 sizeof(pkt_node->tcp_foreignport)); 366 367 counter_list = counter_hash + 368 (hash32_buf(key, sizeof(key), 0) & siftr_hashmask); 369 370 /* 371 * If the list is not empty i.e. the hash index has 372 * been used by another flow previously. 373 */ 374 if (LIST_FIRST(counter_list) != NULL) { 375 /* 376 * Loop through the hash nodes in the list. 377 * There should normally only be 1 hash node in the list, 378 * except if there have been collisions at the hash index 379 * computed by hash32_buf(). 380 */ 381 LIST_FOREACH(hash_node, counter_list, nodes) { 382 /* 383 * Check if the key for the pkt we are currently 384 * processing is the same as the key stored in the 385 * hash node we are currently processing. 386 * If they are the same, then we've found the 387 * hash node that stores the counter for the flow 388 * the pkt belongs to. 389 */ 390 if (memcmp(hash_node->key, key, sizeof(key)) == 0) { 391 found_match = 1; 392 break; 393 } 394 } 395 } 396 397 /* If this flow hash hasn't been seen before or we have a collision. */ 398 if (hash_node == NULL || !found_match) { 399 /* Create a new hash node to store the flow's counter. */ 400 hash_node = malloc(sizeof(struct flow_hash_node), 401 M_SIFTR_HASHNODE, M_WAITOK); 402 403 if (hash_node != NULL) { 404 /* Initialise our new hash node list entry. */ 405 hash_node->counter = 0; 406 memcpy(hash_node->key, key, sizeof(key)); 407 LIST_INSERT_HEAD(counter_list, hash_node, nodes); 408 } else { 409 /* Malloc failed. */ 410 if (pkt_node->direction == PFIL_IN) 411 ss->nskip_in_malloc++; 412 else 413 ss->nskip_out_malloc++; 414 415 return; 416 } 417 } else if (siftr_pkts_per_log > 1) { 418 /* 419 * Taking the remainder of the counter divided 420 * by the current value of siftr_pkts_per_log 421 * and storing that in counter provides a neat 422 * way to modulate the frequency of log 423 * messages being written to the log file. 424 */ 425 hash_node->counter = (hash_node->counter + 1) % 426 siftr_pkts_per_log; 427 428 /* 429 * If we have not seen enough packets since the last time 430 * we wrote a log message for this connection, return. 431 */ 432 if (hash_node->counter > 0) 433 return; 434 } 435 436 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK); 437 438 if (log_buf == NULL) 439 return; /* Should only happen if the ALQ is shutting down. */ 440 441#ifdef SIFTR_IPV6 442 pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]); 443 pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]); 444 445 if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */ 446 pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]); 447 pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]); 448 pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]); 449 pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]); 450 pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]); 451 pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]); 452 453 /* Construct an IPv6 log message. */ 454 log_buf->ae_bytesused = snprintf(log_buf->ae_data, 455 MAX_LOG_MSG_LEN, 456 "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:" 457 "%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u," 458 "%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n", 459 direction[pkt_node->direction], 460 pkt_node->hash, 461 pkt_node->tval.tv_sec, 462 pkt_node->tval.tv_usec, 463 UPPER_SHORT(pkt_node->ip_laddr[0]), 464 LOWER_SHORT(pkt_node->ip_laddr[0]), 465 UPPER_SHORT(pkt_node->ip_laddr[1]), 466 LOWER_SHORT(pkt_node->ip_laddr[1]), 467 UPPER_SHORT(pkt_node->ip_laddr[2]), 468 LOWER_SHORT(pkt_node->ip_laddr[2]), 469 UPPER_SHORT(pkt_node->ip_laddr[3]), 470 LOWER_SHORT(pkt_node->ip_laddr[3]), 471 ntohs(pkt_node->tcp_localport), 472 UPPER_SHORT(pkt_node->ip_faddr[0]), 473 LOWER_SHORT(pkt_node->ip_faddr[0]), 474 UPPER_SHORT(pkt_node->ip_faddr[1]), 475 LOWER_SHORT(pkt_node->ip_faddr[1]), 476 UPPER_SHORT(pkt_node->ip_faddr[2]), 477 LOWER_SHORT(pkt_node->ip_faddr[2]), 478 UPPER_SHORT(pkt_node->ip_faddr[3]), 479 LOWER_SHORT(pkt_node->ip_faddr[3]), 480 ntohs(pkt_node->tcp_foreignport), 481 pkt_node->snd_ssthresh, 482 pkt_node->snd_cwnd, 483 pkt_node->snd_bwnd, 484 pkt_node->snd_wnd, 485 pkt_node->rcv_wnd, 486 pkt_node->snd_scale, 487 pkt_node->rcv_scale, 488 pkt_node->conn_state, 489 pkt_node->max_seg_size, 490 pkt_node->smoothed_rtt, 491 pkt_node->sack_enabled, 492 pkt_node->flags, 493 pkt_node->rxt_length, 494 pkt_node->snd_buf_hiwater, 495 pkt_node->snd_buf_cc, 496 pkt_node->rcv_buf_hiwater, 497 pkt_node->rcv_buf_cc, 498 pkt_node->sent_inflight_bytes, 499 pkt_node->t_segqlen, 500 pkt_node->flowid, 501 pkt_node->flowtype); 502 } else { /* IPv4 packet */ 503 pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]); 504 pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]); 505 pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]); 506 pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]); 507 pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]); 508 pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]); 509 pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]); 510 pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]); 511#endif /* SIFTR_IPV6 */ 512 513 /* Construct an IPv4 log message. */ 514 log_buf->ae_bytesused = snprintf(log_buf->ae_data, 515 MAX_LOG_MSG_LEN, 516 "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld," 517 "%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n", 518 direction[pkt_node->direction], 519 pkt_node->hash, 520 (intmax_t)pkt_node->tval.tv_sec, 521 pkt_node->tval.tv_usec, 522 pkt_node->ip_laddr[0], 523 pkt_node->ip_laddr[1], 524 pkt_node->ip_laddr[2], 525 pkt_node->ip_laddr[3], 526 ntohs(pkt_node->tcp_localport), 527 pkt_node->ip_faddr[0], 528 pkt_node->ip_faddr[1], 529 pkt_node->ip_faddr[2], 530 pkt_node->ip_faddr[3], 531 ntohs(pkt_node->tcp_foreignport), 532 pkt_node->snd_ssthresh, 533 pkt_node->snd_cwnd, 534 pkt_node->snd_bwnd, 535 pkt_node->snd_wnd, 536 pkt_node->rcv_wnd, 537 pkt_node->snd_scale, 538 pkt_node->rcv_scale, 539 pkt_node->conn_state, 540 pkt_node->max_seg_size, 541 pkt_node->smoothed_rtt, 542 pkt_node->sack_enabled, 543 pkt_node->flags, 544 pkt_node->rxt_length, 545 pkt_node->snd_buf_hiwater, 546 pkt_node->snd_buf_cc, 547 pkt_node->rcv_buf_hiwater, 548 pkt_node->rcv_buf_cc, 549 pkt_node->sent_inflight_bytes, 550 pkt_node->t_segqlen, 551 pkt_node->flowid, 552 pkt_node->flowtype); 553#ifdef SIFTR_IPV6 554 } 555#endif 556 557 alq_post_flags(siftr_alq, log_buf, 0); 558} 559 560 561static void 562siftr_pkt_manager_thread(void *arg) 563{ 564 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue = 565 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue); 566 struct pkt_node *pkt_node, *pkt_node_temp; 567 uint8_t draining; 568 569 draining = 2; 570 571 mtx_lock(&siftr_pkt_mgr_mtx); 572 573 /* draining == 0 when queue has been flushed and it's safe to exit. */ 574 while (draining) { 575 /* 576 * Sleep until we are signalled to wake because thread has 577 * been told to exit or until 1 tick has passed. 578 */ 579 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait", 580 1); 581 582 /* Gain exclusive access to the pkt_node queue. */ 583 mtx_lock(&siftr_pkt_queue_mtx); 584 585 /* 586 * Move pkt_queue to tmp_pkt_queue, which leaves 587 * pkt_queue empty and ready to receive more pkt_nodes. 588 */ 589 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue); 590 591 /* 592 * We've finished making changes to the list. Unlock it 593 * so the pfil hooks can continue queuing pkt_nodes. 594 */ 595 mtx_unlock(&siftr_pkt_queue_mtx); 596 597 /* 598 * We can't hold a mutex whilst calling siftr_process_pkt 599 * because ALQ might sleep waiting for buffer space. 600 */ 601 mtx_unlock(&siftr_pkt_mgr_mtx); 602 603 /* Flush all pkt_nodes to the log file. */ 604 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes, 605 pkt_node_temp) { 606 siftr_process_pkt(pkt_node); 607 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes); 608 free(pkt_node, M_SIFTR_PKTNODE); 609 } 610 611 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue), 612 ("SIFTR tmp_pkt_queue not empty after flush")); 613 614 mtx_lock(&siftr_pkt_mgr_mtx); 615 616 /* 617 * If siftr_exit_pkt_manager_thread gets set during the window 618 * where we are draining the tmp_pkt_queue above, there might 619 * still be pkts in pkt_queue that need to be drained. 620 * Allow one further iteration to occur after 621 * siftr_exit_pkt_manager_thread has been set to ensure 622 * pkt_queue is completely empty before we kill the thread. 623 * 624 * siftr_exit_pkt_manager_thread is set only after the pfil 625 * hooks have been removed, so only 1 extra iteration 626 * is needed to drain the queue. 627 */ 628 if (siftr_exit_pkt_manager_thread) 629 draining--; 630 } 631 632 mtx_unlock(&siftr_pkt_mgr_mtx); 633 634 /* Calls wakeup on this thread's struct thread ptr. */ 635 kthread_exit(); 636} 637 638 639static uint32_t 640hash_pkt(struct mbuf *m, uint32_t offset) 641{ 642 uint32_t hash; 643 644 hash = 0; 645 646 while (m != NULL && offset > m->m_len) { 647 /* 648 * The IP packet payload does not start in this mbuf, so 649 * need to figure out which mbuf it starts in and what offset 650 * into the mbuf's data region the payload starts at. 651 */ 652 offset -= m->m_len; 653 m = m->m_next; 654 } 655 656 while (m != NULL) { 657 /* Ensure there is data in the mbuf */ 658 if ((m->m_len - offset) > 0) 659 hash = hash32_buf(m->m_data + offset, 660 m->m_len - offset, hash); 661 662 m = m->m_next; 663 offset = 0; 664 } 665 666 return (hash); 667} 668 669 670/* 671 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that 672 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return. 673 * Return value >0 means the caller should skip processing this mbuf. 674 */ 675static inline int 676siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss) 677{ 678 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL) 679 != NULL) { 680 if (dir == PFIL_IN) 681 ss->nskip_in_dejavu++; 682 else 683 ss->nskip_out_dejavu++; 684 685 return (1); 686 } else { 687 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR, 688 PACKET_TAG_SIFTR, 0, M_NOWAIT); 689 if (tag == NULL) { 690 if (dir == PFIL_IN) 691 ss->nskip_in_malloc++; 692 else 693 ss->nskip_out_malloc++; 694 695 return (1); 696 } 697 698 m_tag_prepend(m, tag); 699 } 700 701 return (0); 702} 703 704 705/* 706 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL 707 * otherwise. 708 */ 709static inline struct inpcb * 710siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport, 711 uint16_t dport, int dir, struct siftr_stats *ss) 712{ 713 struct inpcb *inp; 714 715 /* We need the tcbinfo lock. */ 716 INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo); 717 718 if (dir == PFIL_IN) 719 inp = (ipver == INP_IPV4 ? 720 in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst, 721 dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 722 : 723#ifdef SIFTR_IPV6 724 in6_pcblookup(&V_tcbinfo, 725 &((struct ip6_hdr *)ip)->ip6_src, sport, 726 &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB, 727 m->m_pkthdr.rcvif) 728#else 729 NULL 730#endif 731 ); 732 733 else 734 inp = (ipver == INP_IPV4 ? 735 in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src, 736 sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 737 : 738#ifdef SIFTR_IPV6 739 in6_pcblookup(&V_tcbinfo, 740 &((struct ip6_hdr *)ip)->ip6_dst, dport, 741 &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB, 742 m->m_pkthdr.rcvif) 743#else 744 NULL 745#endif 746 ); 747 748 /* If we can't find the inpcb, bail. */ 749 if (inp == NULL) { 750 if (dir == PFIL_IN) 751 ss->nskip_in_inpcb++; 752 else 753 ss->nskip_out_inpcb++; 754 } 755 756 return (inp); 757} 758 759 760static inline void 761siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp, 762 int ipver, int dir, int inp_locally_locked) 763{ 764#ifdef SIFTR_IPV6 765 if (ipver == INP_IPV4) { 766 pn->ip_laddr[3] = inp->inp_laddr.s_addr; 767 pn->ip_faddr[3] = inp->inp_faddr.s_addr; 768#else 769 *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr; 770 *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr; 771#endif 772#ifdef SIFTR_IPV6 773 } else { 774 pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0]; 775 pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1]; 776 pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2]; 777 pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3]; 778 pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0]; 779 pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1]; 780 pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2]; 781 pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3]; 782 } 783#endif 784 pn->tcp_localport = inp->inp_lport; 785 pn->tcp_foreignport = inp->inp_fport; 786 pn->snd_cwnd = tp->snd_cwnd; 787 pn->snd_wnd = tp->snd_wnd; 788 pn->rcv_wnd = tp->rcv_wnd; 789 pn->snd_bwnd = 0; /* Unused, kept for compat. */ 790 pn->snd_ssthresh = tp->snd_ssthresh; 791 pn->snd_scale = tp->snd_scale; 792 pn->rcv_scale = tp->rcv_scale; 793 pn->conn_state = tp->t_state; 794 pn->max_seg_size = tp->t_maxseg; 795 pn->smoothed_rtt = tp->t_srtt; 796 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0; 797 pn->flags = tp->t_flags; 798 pn->rxt_length = tp->t_rxtcur; 799 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat; 800 pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd); 801 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat; 802 pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv); 803 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una; 804 pn->t_segqlen = tp->t_segqlen; 805 pn->flowid = inp->inp_flowid; 806 pn->flowtype = inp->inp_flowtype; 807 808 /* We've finished accessing the tcb so release the lock. */ 809 if (inp_locally_locked) 810 INP_RUNLOCK(inp); 811 812 pn->ipver = ipver; 813 pn->direction = dir; 814 815 /* 816 * Significantly more accurate than using getmicrotime(), but slower! 817 * Gives true microsecond resolution at the expense of a hit to 818 * maximum pps throughput processing when SIFTR is loaded and enabled. 819 */ 820 microtime(&pn->tval); 821 TCP_PROBE1(siftr, &pn); 822 823} 824 825 826/* 827 * pfil hook that is called for each IPv4 packet making its way through the 828 * stack in either direction. 829 * The pfil subsystem holds a non-sleepable mutex somewhere when 830 * calling our hook function, so we can't sleep at all. 831 * It's very important to use the M_NOWAIT flag with all function calls 832 * that support it so that they won't sleep, otherwise you get a panic. 833 */ 834static int 835siftr_chkpkt(void *arg, struct mbuf **m, struct ifnet *ifp, int dir, 836 struct inpcb *inp) 837{ 838 struct pkt_node *pn; 839 struct ip *ip; 840 struct tcphdr *th; 841 struct tcpcb *tp; 842 struct siftr_stats *ss; 843 unsigned int ip_hl; 844 int inp_locally_locked; 845 846 inp_locally_locked = 0; 847 ss = DPCPU_PTR(ss); 848 849 /* 850 * m_pullup is not required here because ip_{input|output} 851 * already do the heavy lifting for us. 852 */ 853 854 ip = mtod(*m, struct ip *); 855 856 /* Only continue processing if the packet is TCP. */ 857 if (ip->ip_p != IPPROTO_TCP) 858 goto ret; 859 860 /* 861 * If a kernel subsystem reinjects packets into the stack, our pfil 862 * hook will be called multiple times for the same packet. 863 * Make sure we only process unique packets. 864 */ 865 if (siftr_chkreinject(*m, dir, ss)) 866 goto ret; 867 868 if (dir == PFIL_IN) 869 ss->n_in++; 870 else 871 ss->n_out++; 872 873 /* 874 * Create a tcphdr struct starting at the correct offset 875 * in the IP packet. ip->ip_hl gives the ip header length 876 * in 4-byte words, so multiply it to get the size in bytes. 877 */ 878 ip_hl = (ip->ip_hl << 2); 879 th = (struct tcphdr *)((caddr_t)ip + ip_hl); 880 881 /* 882 * If the pfil hooks don't provide a pointer to the 883 * inpcb, we need to find it ourselves and lock it. 884 */ 885 if (!inp) { 886 /* Find the corresponding inpcb for this pkt. */ 887 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport, 888 th->th_dport, dir, ss); 889 890 if (inp == NULL) 891 goto ret; 892 else 893 inp_locally_locked = 1; 894 } 895 896 INP_LOCK_ASSERT(inp); 897 898 /* Find the TCP control block that corresponds with this packet */ 899 tp = intotcpcb(inp); 900 901 /* 902 * If we can't find the TCP control block (happens occasionaly for a 903 * packet sent during the shutdown phase of a TCP connection), 904 * or we're in the timewait state, bail 905 */ 906 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) { 907 if (dir == PFIL_IN) 908 ss->nskip_in_tcpcb++; 909 else 910 ss->nskip_out_tcpcb++; 911 912 goto inp_unlock; 913 } 914 915 /* 916 * Only pkts selected by the tcp port filter 917 * can be inserted into the pkt_queue 918 */ 919 if ((siftr_port_filter != 0) && 920 (siftr_port_filter != ntohs(inp->inp_lport)) && 921 (siftr_port_filter != ntohs(inp->inp_fport))) { 922 goto inp_unlock; 923 } 924 925 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 926 927 if (pn == NULL) { 928 if (dir == PFIL_IN) 929 ss->nskip_in_malloc++; 930 else 931 ss->nskip_out_malloc++; 932 933 goto inp_unlock; 934 } 935 936 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked); 937 938 if (siftr_generate_hashes) { 939 if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) { 940 /* 941 * For outbound packets, the TCP checksum isn't 942 * calculated yet. This is a problem for our packet 943 * hashing as the receiver will calc a different hash 944 * to ours if we don't include the correct TCP checksum 945 * in the bytes being hashed. To work around this 946 * problem, we manually calc the TCP checksum here in 947 * software. We unset the CSUM_TCP flag so the lower 948 * layers don't recalc it. 949 */ 950 (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP; 951 952 /* 953 * Calculate the TCP checksum in software and assign 954 * to correct TCP header field, which will follow the 955 * packet mbuf down the stack. The trick here is that 956 * tcp_output() sets th->th_sum to the checksum of the 957 * pseudo header for us already. Because of the nature 958 * of the checksumming algorithm, we can sum over the 959 * entire IP payload (i.e. TCP header and data), which 960 * will include the already calculated pseduo header 961 * checksum, thus giving us the complete TCP checksum. 962 * 963 * To put it in simple terms, if checksum(1,2,3,4)=10, 964 * then checksum(1,2,3,4,5) == checksum(10,5). 965 * This property is what allows us to "cheat" and 966 * checksum only the IP payload which has the TCP 967 * th_sum field populated with the pseudo header's 968 * checksum, and not need to futz around checksumming 969 * pseudo header bytes and TCP header/data in one hit. 970 * Refer to RFC 1071 for more info. 971 * 972 * NB: in_cksum_skip(struct mbuf *m, int len, int skip) 973 * in_cksum_skip 2nd argument is NOT the number of 974 * bytes to read from the mbuf at "skip" bytes offset 975 * from the start of the mbuf (very counter intuitive!). 976 * The number of bytes to read is calculated internally 977 * by the function as len-skip i.e. to sum over the IP 978 * payload (TCP header + data) bytes, it is INCORRECT 979 * to call the function like this: 980 * in_cksum_skip(at, ip->ip_len - offset, offset) 981 * Rather, it should be called like this: 982 * in_cksum_skip(at, ip->ip_len, offset) 983 * which means read "ip->ip_len - offset" bytes from 984 * the mbuf cluster "at" at offset "offset" bytes from 985 * the beginning of the "at" mbuf's data pointer. 986 */ 987 th->th_sum = in_cksum_skip(*m, ntohs(ip->ip_len), 988 ip_hl); 989 } 990 991 /* 992 * XXX: Having to calculate the checksum in software and then 993 * hash over all bytes is really inefficient. Would be nice to 994 * find a way to create the hash and checksum in the same pass 995 * over the bytes. 996 */ 997 pn->hash = hash_pkt(*m, ip_hl); 998 } 999 1000 mtx_lock(&siftr_pkt_queue_mtx); 1001 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 1002 mtx_unlock(&siftr_pkt_queue_mtx); 1003 goto ret; 1004 1005inp_unlock: 1006 if (inp_locally_locked) 1007 INP_RUNLOCK(inp); 1008 1009ret: 1010 /* Returning 0 ensures pfil will not discard the pkt */ 1011 return (0); 1012} 1013 1014 1015#ifdef SIFTR_IPV6 1016static int 1017siftr_chkpkt6(void *arg, struct mbuf **m, struct ifnet *ifp, int dir, 1018 struct inpcb *inp) 1019{ 1020 struct pkt_node *pn; 1021 struct ip6_hdr *ip6; 1022 struct tcphdr *th; 1023 struct tcpcb *tp; 1024 struct siftr_stats *ss; 1025 unsigned int ip6_hl; 1026 int inp_locally_locked; 1027 1028 inp_locally_locked = 0; 1029 ss = DPCPU_PTR(ss); 1030 1031 /* 1032 * m_pullup is not required here because ip6_{input|output} 1033 * already do the heavy lifting for us. 1034 */ 1035 1036 ip6 = mtod(*m, struct ip6_hdr *); 1037 1038 /* 1039 * Only continue processing if the packet is TCP 1040 * XXX: We should follow the next header fields 1041 * as shown on Pg 6 RFC 2460, but right now we'll 1042 * only check pkts that have no extension headers. 1043 */ 1044 if (ip6->ip6_nxt != IPPROTO_TCP) 1045 goto ret6; 1046 1047 /* 1048 * If a kernel subsystem reinjects packets into the stack, our pfil 1049 * hook will be called multiple times for the same packet. 1050 * Make sure we only process unique packets. 1051 */ 1052 if (siftr_chkreinject(*m, dir, ss)) 1053 goto ret6; 1054 1055 if (dir == PFIL_IN) 1056 ss->n_in++; 1057 else 1058 ss->n_out++; 1059 1060 ip6_hl = sizeof(struct ip6_hdr); 1061 1062 /* 1063 * Create a tcphdr struct starting at the correct offset 1064 * in the ipv6 packet. ip->ip_hl gives the ip header length 1065 * in 4-byte words, so multiply it to get the size in bytes. 1066 */ 1067 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl); 1068 1069 /* 1070 * For inbound packets, the pfil hooks don't provide a pointer to the 1071 * inpcb, so we need to find it ourselves and lock it. 1072 */ 1073 if (!inp) { 1074 /* Find the corresponding inpcb for this pkt. */ 1075 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m, 1076 th->th_sport, th->th_dport, dir, ss); 1077 1078 if (inp == NULL) 1079 goto ret6; 1080 else 1081 inp_locally_locked = 1; 1082 } 1083 1084 /* Find the TCP control block that corresponds with this packet. */ 1085 tp = intotcpcb(inp); 1086 1087 /* 1088 * If we can't find the TCP control block (happens occasionaly for a 1089 * packet sent during the shutdown phase of a TCP connection), 1090 * or we're in the timewait state, bail. 1091 */ 1092 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) { 1093 if (dir == PFIL_IN) 1094 ss->nskip_in_tcpcb++; 1095 else 1096 ss->nskip_out_tcpcb++; 1097 1098 goto inp_unlock6; 1099 } 1100 1101 /* 1102 * Only pkts selected by the tcp port filter 1103 * can be inserted into the pkt_queue 1104 */ 1105 if ((siftr_port_filter != 0) && 1106 (siftr_port_filter != ntohs(inp->inp_lport)) && 1107 (siftr_port_filter != ntohs(inp->inp_fport))) { 1108 goto inp_unlock6; 1109 } 1110 1111 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 1112 1113 if (pn == NULL) { 1114 if (dir == PFIL_IN) 1115 ss->nskip_in_malloc++; 1116 else 1117 ss->nskip_out_malloc++; 1118 1119 goto inp_unlock6; 1120 } 1121 1122 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked); 1123 1124 /* XXX: Figure out how to generate hashes for IPv6 packets. */ 1125 1126 mtx_lock(&siftr_pkt_queue_mtx); 1127 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 1128 mtx_unlock(&siftr_pkt_queue_mtx); 1129 goto ret6; 1130 1131inp_unlock6: 1132 if (inp_locally_locked) 1133 INP_RUNLOCK(inp); 1134 1135ret6: 1136 /* Returning 0 ensures pfil will not discard the pkt. */ 1137 return (0); 1138} 1139#endif /* #ifdef SIFTR_IPV6 */ 1140 1141 1142static int 1143siftr_pfil(int action) 1144{ 1145 struct pfil_head *pfh_inet; 1146#ifdef SIFTR_IPV6 1147 struct pfil_head *pfh_inet6; 1148#endif 1149 VNET_ITERATOR_DECL(vnet_iter); 1150 1151 VNET_LIST_RLOCK(); 1152 VNET_FOREACH(vnet_iter) { 1153 CURVNET_SET(vnet_iter); 1154 pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET); 1155#ifdef SIFTR_IPV6 1156 pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6); 1157#endif 1158 1159 if (action == HOOK) { 1160 pfil_add_hook(siftr_chkpkt, NULL, 1161 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet); 1162#ifdef SIFTR_IPV6 1163 pfil_add_hook(siftr_chkpkt6, NULL, 1164 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6); 1165#endif 1166 } else if (action == UNHOOK) { 1167 pfil_remove_hook(siftr_chkpkt, NULL, 1168 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet); 1169#ifdef SIFTR_IPV6 1170 pfil_remove_hook(siftr_chkpkt6, NULL, 1171 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6); 1172#endif 1173 } 1174 CURVNET_RESTORE(); 1175 } 1176 VNET_LIST_RUNLOCK(); 1177 1178 return (0); 1179} 1180 1181 1182static int 1183siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS) 1184{ 1185 struct alq *new_alq; 1186 int error; 1187 1188 error = sysctl_handle_string(oidp, arg1, arg2, req); 1189 1190 /* Check for error or same filename */ 1191 if (error != 0 || req->newptr == NULL || 1192 strncmp(siftr_logfile, arg1, arg2) == 0) 1193 goto done; 1194 1195 /* Filname changed */ 1196 error = alq_open(&new_alq, arg1, curthread->td_ucred, 1197 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1198 if (error != 0) 1199 goto done; 1200 1201 /* 1202 * If disabled, siftr_alq == NULL so we simply close 1203 * the alq as we've proved it can be opened. 1204 * If enabled, close the existing alq and switch the old 1205 * for the new. 1206 */ 1207 if (siftr_alq == NULL) { 1208 alq_close(new_alq); 1209 } else { 1210 alq_close(siftr_alq); 1211 siftr_alq = new_alq; 1212 } 1213 1214 /* Update filename upon success */ 1215 strlcpy(siftr_logfile, arg1, arg2); 1216done: 1217 return (error); 1218} 1219 1220static int 1221siftr_manage_ops(uint8_t action) 1222{ 1223 struct siftr_stats totalss; 1224 struct timeval tval; 1225 struct flow_hash_node *counter, *tmp_counter; 1226 struct sbuf *s; 1227 int i, key_index, error; 1228 uint32_t bytes_to_write, total_skipped_pkts; 1229 uint16_t lport, fport; 1230 uint8_t *key, ipver __unused; 1231 1232#ifdef SIFTR_IPV6 1233 uint32_t laddr[4]; 1234 uint32_t faddr[4]; 1235#else 1236 uint8_t laddr[4]; 1237 uint8_t faddr[4]; 1238#endif 1239 1240 error = 0; 1241 total_skipped_pkts = 0; 1242 1243 /* Init an autosizing sbuf that initially holds 200 chars. */ 1244 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL) 1245 return (-1); 1246 1247 if (action == SIFTR_ENABLE && siftr_pkt_manager_thr == NULL) { 1248 /* 1249 * Create our alq 1250 * XXX: We should abort if alq_open fails! 1251 */ 1252 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred, 1253 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1254 1255 STAILQ_INIT(&pkt_queue); 1256 1257 DPCPU_ZERO(ss); 1258 1259 siftr_exit_pkt_manager_thread = 0; 1260 1261 kthread_add(&siftr_pkt_manager_thread, NULL, NULL, 1262 &siftr_pkt_manager_thr, RFNOWAIT, 0, 1263 "siftr_pkt_manager_thr"); 1264 1265 siftr_pfil(HOOK); 1266 1267 microtime(&tval); 1268 1269 sbuf_printf(s, 1270 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t" 1271 "siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t" 1272 "sysver=%u\tipmode=%u\n", 1273 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz, 1274 TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE); 1275 1276 sbuf_finish(s); 1277 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK); 1278 1279 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) { 1280 /* 1281 * Remove the pfil hook functions. All threads currently in 1282 * the hook functions are allowed to exit before siftr_pfil() 1283 * returns. 1284 */ 1285 siftr_pfil(UNHOOK); 1286 1287 /* This will block until the pkt manager thread unlocks it. */ 1288 mtx_lock(&siftr_pkt_mgr_mtx); 1289 1290 /* Tell the pkt manager thread that it should exit now. */ 1291 siftr_exit_pkt_manager_thread = 1; 1292 1293 /* 1294 * Wake the pkt_manager thread so it realises that 1295 * siftr_exit_pkt_manager_thread == 1 and exits gracefully. 1296 * The wakeup won't be delivered until we unlock 1297 * siftr_pkt_mgr_mtx so this isn't racy. 1298 */ 1299 wakeup(&wait_for_pkt); 1300 1301 /* Wait for the pkt_manager thread to exit. */ 1302 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT, 1303 "thrwait", 0); 1304 1305 siftr_pkt_manager_thr = NULL; 1306 mtx_unlock(&siftr_pkt_mgr_mtx); 1307 1308 totalss.n_in = DPCPU_VARSUM(ss, n_in); 1309 totalss.n_out = DPCPU_VARSUM(ss, n_out); 1310 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc); 1311 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc); 1312 totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx); 1313 totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx); 1314 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb); 1315 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb); 1316 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb); 1317 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb); 1318 1319 total_skipped_pkts = totalss.nskip_in_malloc + 1320 totalss.nskip_out_malloc + totalss.nskip_in_mtx + 1321 totalss.nskip_out_mtx + totalss.nskip_in_tcpcb + 1322 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb + 1323 totalss.nskip_out_inpcb; 1324 1325 microtime(&tval); 1326 1327 sbuf_printf(s, 1328 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t" 1329 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t" 1330 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t" 1331 "num_outbound_skipped_pkts_malloc=%u\t" 1332 "num_inbound_skipped_pkts_mtx=%u\t" 1333 "num_outbound_skipped_pkts_mtx=%u\t" 1334 "num_inbound_skipped_pkts_tcpcb=%u\t" 1335 "num_outbound_skipped_pkts_tcpcb=%u\t" 1336 "num_inbound_skipped_pkts_inpcb=%u\t" 1337 "num_outbound_skipped_pkts_inpcb=%u\t" 1338 "total_skipped_tcp_pkts=%u\tflow_list=", 1339 (intmax_t)tval.tv_sec, 1340 tval.tv_usec, 1341 (uintmax_t)totalss.n_in, 1342 (uintmax_t)totalss.n_out, 1343 (uintmax_t)(totalss.n_in + totalss.n_out), 1344 totalss.nskip_in_malloc, 1345 totalss.nskip_out_malloc, 1346 totalss.nskip_in_mtx, 1347 totalss.nskip_out_mtx, 1348 totalss.nskip_in_tcpcb, 1349 totalss.nskip_out_tcpcb, 1350 totalss.nskip_in_inpcb, 1351 totalss.nskip_out_inpcb, 1352 total_skipped_pkts); 1353 1354 /* 1355 * Iterate over the flow hash, printing a summary of each 1356 * flow seen and freeing any malloc'd memory. 1357 * The hash consists of an array of LISTs (man 3 queue). 1358 */ 1359 for (i = 0; i <= siftr_hashmask; i++) { 1360 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes, 1361 tmp_counter) { 1362 key = counter->key; 1363 key_index = 1; 1364 1365 ipver = key[0]; 1366 1367 memcpy(laddr, key + key_index, sizeof(laddr)); 1368 key_index += sizeof(laddr); 1369 memcpy(&lport, key + key_index, sizeof(lport)); 1370 key_index += sizeof(lport); 1371 memcpy(faddr, key + key_index, sizeof(faddr)); 1372 key_index += sizeof(faddr); 1373 memcpy(&fport, key + key_index, sizeof(fport)); 1374 1375#ifdef SIFTR_IPV6 1376 laddr[3] = ntohl(laddr[3]); 1377 faddr[3] = ntohl(faddr[3]); 1378 1379 if (ipver == INP_IPV6) { 1380 laddr[0] = ntohl(laddr[0]); 1381 laddr[1] = ntohl(laddr[1]); 1382 laddr[2] = ntohl(laddr[2]); 1383 faddr[0] = ntohl(faddr[0]); 1384 faddr[1] = ntohl(faddr[1]); 1385 faddr[2] = ntohl(faddr[2]); 1386 1387 sbuf_printf(s, 1388 "%x:%x:%x:%x:%x:%x:%x:%x;%u-" 1389 "%x:%x:%x:%x:%x:%x:%x:%x;%u,", 1390 UPPER_SHORT(laddr[0]), 1391 LOWER_SHORT(laddr[0]), 1392 UPPER_SHORT(laddr[1]), 1393 LOWER_SHORT(laddr[1]), 1394 UPPER_SHORT(laddr[2]), 1395 LOWER_SHORT(laddr[2]), 1396 UPPER_SHORT(laddr[3]), 1397 LOWER_SHORT(laddr[3]), 1398 ntohs(lport), 1399 UPPER_SHORT(faddr[0]), 1400 LOWER_SHORT(faddr[0]), 1401 UPPER_SHORT(faddr[1]), 1402 LOWER_SHORT(faddr[1]), 1403 UPPER_SHORT(faddr[2]), 1404 LOWER_SHORT(faddr[2]), 1405 UPPER_SHORT(faddr[3]), 1406 LOWER_SHORT(faddr[3]), 1407 ntohs(fport)); 1408 } else { 1409 laddr[0] = FIRST_OCTET(laddr[3]); 1410 laddr[1] = SECOND_OCTET(laddr[3]); 1411 laddr[2] = THIRD_OCTET(laddr[3]); 1412 laddr[3] = FOURTH_OCTET(laddr[3]); 1413 faddr[0] = FIRST_OCTET(faddr[3]); 1414 faddr[1] = SECOND_OCTET(faddr[3]); 1415 faddr[2] = THIRD_OCTET(faddr[3]); 1416 faddr[3] = FOURTH_OCTET(faddr[3]); 1417#endif 1418 sbuf_printf(s, 1419 "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,", 1420 laddr[0], 1421 laddr[1], 1422 laddr[2], 1423 laddr[3], 1424 ntohs(lport), 1425 faddr[0], 1426 faddr[1], 1427 faddr[2], 1428 faddr[3], 1429 ntohs(fport)); 1430#ifdef SIFTR_IPV6 1431 } 1432#endif 1433 1434 free(counter, M_SIFTR_HASHNODE); 1435 } 1436 1437 LIST_INIT(counter_hash + i); 1438 } 1439 1440 sbuf_printf(s, "\n"); 1441 sbuf_finish(s); 1442 1443 i = 0; 1444 do { 1445 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i); 1446 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK); 1447 i += bytes_to_write; 1448 } while (i < sbuf_len(s)); 1449 1450 alq_close(siftr_alq); 1451 siftr_alq = NULL; 1452 } else 1453 error = EINVAL; 1454 1455 sbuf_delete(s); 1456 1457 /* 1458 * XXX: Should be using ret to check if any functions fail 1459 * and set error appropriately 1460 */ 1461 1462 return (error); 1463} 1464 1465 1466static int 1467siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS) 1468{ 1469 int error; 1470 uint32_t new; 1471 1472 new = siftr_enabled; 1473 error = sysctl_handle_int(oidp, &new, 0, req); 1474 if (error == 0 && req->newptr != NULL) { 1475 if (new > 1) 1476 return (EINVAL); 1477 else if (new != siftr_enabled) { 1478 if ((error = siftr_manage_ops(new)) == 0) { 1479 siftr_enabled = new; 1480 } else { 1481 siftr_manage_ops(SIFTR_DISABLE); 1482 } 1483 } 1484 } 1485 1486 return (error); 1487} 1488 1489 1490static void 1491siftr_shutdown_handler(void *arg) 1492{ 1493 if (siftr_enabled == 1) { 1494 siftr_manage_ops(SIFTR_DISABLE); 1495 } 1496} 1497 1498 1499/* 1500 * Module is being unloaded or machine is shutting down. Take care of cleanup. 1501 */ 1502static int 1503deinit_siftr(void) 1504{ 1505 /* Cleanup. */ 1506 siftr_manage_ops(SIFTR_DISABLE); 1507 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask); 1508 mtx_destroy(&siftr_pkt_queue_mtx); 1509 mtx_destroy(&siftr_pkt_mgr_mtx); 1510 1511 return (0); 1512} 1513 1514 1515/* 1516 * Module has just been loaded into the kernel. 1517 */ 1518static int 1519init_siftr(void) 1520{ 1521 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL, 1522 SHUTDOWN_PRI_FIRST); 1523 1524 /* Initialise our flow counter hash table. */ 1525 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR, 1526 &siftr_hashmask); 1527 1528 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF); 1529 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF); 1530 1531 /* Print message to the user's current terminal. */ 1532 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n" 1533 " http://caia.swin.edu.au/urp/newtcp\n\n", 1534 MODVERSION_STR); 1535 1536 return (0); 1537} 1538 1539 1540/* 1541 * This is the function that is called to load and unload the module. 1542 * When the module is loaded, this function is called once with 1543 * "what" == MOD_LOAD 1544 * When the module is unloaded, this function is called twice with 1545 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second 1546 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command, 1547 * this function is called once with "what" = MOD_SHUTDOWN 1548 * When the system is shut down, the handler isn't called until the very end 1549 * of the shutdown sequence i.e. after the disks have been synced. 1550 */ 1551static int 1552siftr_load_handler(module_t mod, int what, void *arg) 1553{ 1554 int ret; 1555 1556 switch (what) { 1557 case MOD_LOAD: 1558 ret = init_siftr(); 1559 break; 1560 1561 case MOD_QUIESCE: 1562 case MOD_SHUTDOWN: 1563 ret = deinit_siftr(); 1564 break; 1565 1566 case MOD_UNLOAD: 1567 ret = 0; 1568 break; 1569 1570 default: 1571 ret = EINVAL; 1572 break; 1573 } 1574 1575 return (ret); 1576} 1577 1578 1579static moduledata_t siftr_mod = { 1580 .name = "siftr", 1581 .evhand = siftr_load_handler, 1582}; 1583 1584/* 1585 * Param 1: name of the kernel module 1586 * Param 2: moduledata_t struct containing info about the kernel module 1587 * and the execution entry point for the module 1588 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h 1589 * Defines the module initialisation order 1590 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h 1591 * Defines the initialisation order of this kld relative to others 1592 * within the same subsystem as defined by param 3 1593 */ 1594DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY); 1595MODULE_DEPEND(siftr, alq, 1, 1, 1); 1596MODULE_VERSION(siftr, MODVERSION); 1597