1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 #include <net/route.h> 91 92 #include <netinet/in.h> 93 #include <netinet/in_kdtrace.h> 94 #include <netinet/in_fib.h> 95 #include <netinet/in_pcb.h> 96 #include <netinet/in_systm.h> 97 #include <netinet/in_var.h> 98 #include <netinet/ip.h> 99 #include <netinet/ip_var.h> 100 #include <netinet/tcp_var.h> 101 102 #ifdef SIFTR_IPV6 103 #include <netinet/ip6.h> 104 #include <netinet6/ip6_var.h> 105 #include <netinet6/in6_fib.h> 106 #include <netinet6/in6_pcb.h> 107 #endif /* SIFTR_IPV6 */ 108 109 #include <machine/in_cksum.h> 110 111 /* 112 * Three digit version number refers to X.Y.Z where: 113 * X is the major version number 114 * Y is bumped to mark backwards incompatible changes 115 * Z is bumped to mark backwards compatible changes 116 */ 117 #define V_MAJOR 1 118 #define V_BACKBREAK 3 119 #define V_BACKCOMPAT 0 120 #define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT)) 121 #define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \ 122 __XSTRING(V_BACKCOMPAT) 123 124 #define HOOK 0 125 #define UNHOOK 1 126 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536 127 #define SYS_NAME "FreeBSD" 128 #define PACKET_TAG_SIFTR 100 129 #define PACKET_COOKIE_SIFTR 21749576 130 #define SIFTR_LOG_FILE_MODE 0644 131 #define SIFTR_DISABLE 0 132 #define SIFTR_ENABLE 1 133 134 /* 135 * Hard upper limit on the length of log messages. Bump this up if you add new 136 * data fields such that the line length could exceed the below value. 137 */ 138 #define MAX_LOG_MSG_LEN 300 139 /* XXX: Make this a sysctl tunable. */ 140 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN) 141 142 #ifdef SIFTR_IPV6 143 #define SIFTR_IPMODE 6 144 #else 145 #define SIFTR_IPMODE 4 146 #endif 147 148 static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR"); 149 static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode", 150 "SIFTR pkt_node struct"); 151 static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode", 152 "SIFTR flow_hash_node struct"); 153 154 /* Used as links in the pkt manager queue. */ 155 struct pkt_node { 156 /* Timestamp of pkt as noted in the pfil hook. */ 157 struct timeval tval; 158 /* Direction pkt is travelling. */ 159 enum { 160 DIR_IN = 0, 161 DIR_OUT = 1, 162 } direction; 163 /* Congestion Window (bytes). */ 164 uint32_t snd_cwnd; 165 /* Sending Window (bytes). */ 166 uint32_t snd_wnd; 167 /* Receive Window (bytes). */ 168 uint32_t rcv_wnd; 169 /* More tcpcb flags storage */ 170 uint32_t t_flags2; 171 /* Slow Start Threshold (bytes). */ 172 uint32_t snd_ssthresh; 173 /* Current state of the TCP FSM. */ 174 int conn_state; 175 /* Max Segment Size (bytes). */ 176 u_int max_seg_size; 177 /* Smoothed RTT (usecs). */ 178 uint32_t srtt; 179 /* Is SACK enabled? */ 180 u_char sack_enabled; 181 /* Window scaling for snd window. */ 182 u_char snd_scale; 183 /* Window scaling for recv window. */ 184 u_char rcv_scale; 185 /* TCP control block flags. */ 186 u_int flags; 187 /* Retransmission timeout (usec). */ 188 uint32_t rto; 189 /* Size of the TCP send buffer in bytes. */ 190 u_int snd_buf_hiwater; 191 /* Current num bytes in the send socket buffer. */ 192 u_int snd_buf_cc; 193 /* Size of the TCP receive buffer in bytes. */ 194 u_int rcv_buf_hiwater; 195 /* Current num bytes in the receive socket buffer. */ 196 u_int rcv_buf_cc; 197 /* Number of bytes inflight that we are waiting on ACKs for. */ 198 u_int sent_inflight_bytes; 199 /* Number of segments currently in the reassembly queue. */ 200 int t_segqlen; 201 /* Flowid for the connection. */ 202 u_int flowid; 203 /* Flow type for the connection. */ 204 u_int flowtype; 205 /* Link to next pkt_node in the list. */ 206 STAILQ_ENTRY(pkt_node) nodes; 207 }; 208 209 struct flow_info 210 { 211 #ifdef SIFTR_IPV6 212 char laddr[INET6_ADDRSTRLEN]; /* local IP address */ 213 char faddr[INET6_ADDRSTRLEN]; /* foreign IP address */ 214 #else 215 char laddr[INET_ADDRSTRLEN]; /* local IP address */ 216 char faddr[INET_ADDRSTRLEN]; /* foreign IP address */ 217 #endif 218 uint16_t lport; /* local TCP port */ 219 uint16_t fport; /* foreign TCP port */ 220 uint8_t ipver; /* IP version */ 221 uint32_t key; /* flowid of the connection */ 222 }; 223 224 struct flow_hash_node 225 { 226 uint16_t counter; 227 struct flow_info const_info; /* constant connection info */ 228 LIST_ENTRY(flow_hash_node) nodes; 229 }; 230 231 struct siftr_stats 232 { 233 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */ 234 uint64_t n_in; 235 uint64_t n_out; 236 /* # pkts skipped due to failed malloc calls. */ 237 uint32_t nskip_in_malloc; 238 uint32_t nskip_out_malloc; 239 /* # pkts skipped due to failed inpcb lookups. */ 240 uint32_t nskip_in_inpcb; 241 uint32_t nskip_out_inpcb; 242 /* # pkts skipped due to failed tcpcb lookups. */ 243 uint32_t nskip_in_tcpcb; 244 uint32_t nskip_out_tcpcb; 245 /* # pkts skipped due to stack reinjection. */ 246 uint32_t nskip_in_dejavu; 247 uint32_t nskip_out_dejavu; 248 }; 249 250 DPCPU_DEFINE_STATIC(struct siftr_stats, ss); 251 252 static volatile unsigned int siftr_exit_pkt_manager_thread = 0; 253 static unsigned int siftr_enabled = 0; 254 static unsigned int siftr_pkts_per_log = 1; 255 static uint16_t siftr_port_filter = 0; 256 /* static unsigned int siftr_binary_log = 0; */ 257 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log"; 258 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log"; 259 static u_long siftr_hashmask; 260 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue); 261 LIST_HEAD(listhead, flow_hash_node) *counter_hash; 262 static int wait_for_pkt; 263 static struct alq *siftr_alq = NULL; 264 static struct mtx siftr_pkt_queue_mtx; 265 static struct mtx siftr_pkt_mgr_mtx; 266 static struct thread *siftr_pkt_manager_thr = NULL; 267 static char direction[2] = {'i','o'}; 268 269 /* Required function prototypes. */ 270 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS); 271 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS); 272 273 /* Declare the net.inet.siftr sysctl tree and populate it. */ 274 275 SYSCTL_DECL(_net_inet_siftr); 276 277 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 278 "siftr related settings"); 279 280 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, 281 CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 282 &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU", 283 "switch siftr module operations on/off"); 284 285 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, 286 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &siftr_logfile_shadow, 287 sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler, "A", 288 "file to save siftr log messages to"); 289 290 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW, 291 &siftr_pkts_per_log, 1, 292 "number of packets between generating a log message"); 293 294 SYSCTL_U16(_net_inet_siftr, OID_AUTO, port_filter, CTLFLAG_RW, 295 &siftr_port_filter, 0, 296 "enable packet filter on a TCP port"); 297 298 /* XXX: TODO 299 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW, 300 &siftr_binary_log, 0, 301 "write log files in binary instead of ascii"); 302 */ 303 304 /* Begin functions. */ 305 306 static inline struct flow_hash_node * 307 siftr_find_flow(struct listhead *counter_list, uint32_t id) 308 { 309 struct flow_hash_node *hash_node; 310 /* 311 * If the list is not empty i.e. the hash index has 312 * been used by another flow previously. 313 */ 314 if (LIST_FIRST(counter_list) != NULL) { 315 /* 316 * Loop through the hash nodes in the list. 317 * There should normally only be 1 hash node in the list. 318 */ 319 LIST_FOREACH(hash_node, counter_list, nodes) { 320 /* 321 * Check if the key for the pkt we are currently 322 * processing is the same as the key stored in the 323 * hash node we are currently processing. 324 * If they are the same, then we've found the 325 * hash node that stores the counter for the flow 326 * the pkt belongs to. 327 */ 328 if (hash_node->const_info.key == id) { 329 return hash_node; 330 } 331 } 332 } 333 334 return NULL; 335 } 336 337 static inline struct flow_hash_node * 338 siftr_new_hash_node(struct flow_info info, int dir, 339 struct siftr_stats *ss) 340 { 341 struct flow_hash_node *hash_node; 342 struct listhead *counter_list; 343 344 counter_list = counter_hash + (info.key & siftr_hashmask); 345 /* Create a new hash node to store the flow's constant info. */ 346 hash_node = malloc(sizeof(struct flow_hash_node), M_SIFTR_HASHNODE, 347 M_NOWAIT|M_ZERO); 348 349 if (hash_node != NULL) { 350 /* Initialise our new hash node list entry. */ 351 hash_node->counter = 0; 352 hash_node->const_info = info; 353 LIST_INSERT_HEAD(counter_list, hash_node, nodes); 354 return hash_node; 355 } else { 356 /* malloc failed */ 357 if (dir == DIR_IN) 358 ss->nskip_in_malloc++; 359 else 360 ss->nskip_out_malloc++; 361 362 return NULL; 363 } 364 } 365 366 static void 367 siftr_process_pkt(struct pkt_node * pkt_node) 368 { 369 struct flow_hash_node *hash_node; 370 struct listhead *counter_list; 371 struct ale *log_buf; 372 373 if (pkt_node->flowid == 0) { 374 panic("%s: flowid not available", __func__); 375 } 376 377 counter_list = counter_hash + (pkt_node->flowid & siftr_hashmask); 378 hash_node = siftr_find_flow(counter_list, pkt_node->flowid); 379 380 if (hash_node == NULL) { 381 return; 382 } else if (siftr_pkts_per_log > 1) { 383 /* 384 * Taking the remainder of the counter divided 385 * by the current value of siftr_pkts_per_log 386 * and storing that in counter provides a neat 387 * way to modulate the frequency of log 388 * messages being written to the log file. 389 */ 390 hash_node->counter = (hash_node->counter + 1) % 391 siftr_pkts_per_log; 392 /* 393 * If we have not seen enough packets since the last time 394 * we wrote a log message for this connection, return. 395 */ 396 if (hash_node->counter > 0) 397 return; 398 } 399 400 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK); 401 402 if (log_buf == NULL) 403 return; /* Should only happen if the ALQ is shutting down. */ 404 405 /* Construct a log message. */ 406 log_buf->ae_bytesused = snprintf(log_buf->ae_data, MAX_LOG_MSG_LEN, 407 "%c,%jd.%06ld,%s,%hu,%s,%hu,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u," 408 "%u,%u,%u,%u,%u,%u,%u,%u\n", 409 direction[pkt_node->direction], 410 (intmax_t)pkt_node->tval.tv_sec, 411 pkt_node->tval.tv_usec, 412 hash_node->const_info.laddr, 413 hash_node->const_info.lport, 414 hash_node->const_info.faddr, 415 hash_node->const_info.fport, 416 pkt_node->snd_ssthresh, 417 pkt_node->snd_cwnd, 418 pkt_node->t_flags2, 419 pkt_node->snd_wnd, 420 pkt_node->rcv_wnd, 421 pkt_node->snd_scale, 422 pkt_node->rcv_scale, 423 pkt_node->conn_state, 424 pkt_node->max_seg_size, 425 pkt_node->srtt, 426 pkt_node->sack_enabled, 427 pkt_node->flags, 428 pkt_node->rto, 429 pkt_node->snd_buf_hiwater, 430 pkt_node->snd_buf_cc, 431 pkt_node->rcv_buf_hiwater, 432 pkt_node->rcv_buf_cc, 433 pkt_node->sent_inflight_bytes, 434 pkt_node->t_segqlen, 435 pkt_node->flowid, 436 pkt_node->flowtype); 437 438 alq_post_flags(siftr_alq, log_buf, 0); 439 } 440 441 static void 442 siftr_pkt_manager_thread(void *arg) 443 { 444 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue = 445 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue); 446 struct pkt_node *pkt_node, *pkt_node_temp; 447 uint8_t draining; 448 449 draining = 2; 450 451 mtx_lock(&siftr_pkt_mgr_mtx); 452 453 /* draining == 0 when queue has been flushed and it's safe to exit. */ 454 while (draining) { 455 /* 456 * Sleep until we are signalled to wake because thread has 457 * been told to exit or until 1 tick has passed. 458 */ 459 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait", 460 1); 461 462 /* Gain exclusive access to the pkt_node queue. */ 463 mtx_lock(&siftr_pkt_queue_mtx); 464 465 /* 466 * Move pkt_queue to tmp_pkt_queue, which leaves 467 * pkt_queue empty and ready to receive more pkt_nodes. 468 */ 469 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue); 470 471 /* 472 * We've finished making changes to the list. Unlock it 473 * so the pfil hooks can continue queuing pkt_nodes. 474 */ 475 mtx_unlock(&siftr_pkt_queue_mtx); 476 477 /* 478 * We can't hold a mutex whilst calling siftr_process_pkt 479 * because ALQ might sleep waiting for buffer space. 480 */ 481 mtx_unlock(&siftr_pkt_mgr_mtx); 482 483 /* Flush all pkt_nodes to the log file. */ 484 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes, 485 pkt_node_temp) { 486 siftr_process_pkt(pkt_node); 487 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes); 488 free(pkt_node, M_SIFTR_PKTNODE); 489 } 490 491 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue), 492 ("SIFTR tmp_pkt_queue not empty after flush")); 493 494 mtx_lock(&siftr_pkt_mgr_mtx); 495 496 /* 497 * If siftr_exit_pkt_manager_thread gets set during the window 498 * where we are draining the tmp_pkt_queue above, there might 499 * still be pkts in pkt_queue that need to be drained. 500 * Allow one further iteration to occur after 501 * siftr_exit_pkt_manager_thread has been set to ensure 502 * pkt_queue is completely empty before we kill the thread. 503 * 504 * siftr_exit_pkt_manager_thread is set only after the pfil 505 * hooks have been removed, so only 1 extra iteration 506 * is needed to drain the queue. 507 */ 508 if (siftr_exit_pkt_manager_thread) 509 draining--; 510 } 511 512 mtx_unlock(&siftr_pkt_mgr_mtx); 513 514 /* Calls wakeup on this thread's struct thread ptr. */ 515 kthread_exit(); 516 } 517 518 /* 519 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that 520 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return. 521 * Return value >0 means the caller should skip processing this mbuf. 522 */ 523 static inline int 524 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss) 525 { 526 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL) 527 != NULL) { 528 if (dir == PFIL_IN) 529 ss->nskip_in_dejavu++; 530 else 531 ss->nskip_out_dejavu++; 532 533 return (1); 534 } else { 535 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR, 536 PACKET_TAG_SIFTR, 0, M_NOWAIT); 537 if (tag == NULL) { 538 if (dir == PFIL_IN) 539 ss->nskip_in_malloc++; 540 else 541 ss->nskip_out_malloc++; 542 543 return (1); 544 } 545 546 m_tag_prepend(m, tag); 547 } 548 549 return (0); 550 } 551 552 /* 553 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL 554 * otherwise. 555 */ 556 static inline struct inpcb * 557 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport, 558 uint16_t dport, int dir, struct siftr_stats *ss) 559 { 560 struct inpcb *inp; 561 562 /* We need the tcbinfo lock. */ 563 INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo); 564 565 if (dir == PFIL_IN) 566 inp = (ipver == INP_IPV4 ? 567 in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst, 568 dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 569 : 570 #ifdef SIFTR_IPV6 571 in6_pcblookup(&V_tcbinfo, 572 &((struct ip6_hdr *)ip)->ip6_src, sport, 573 &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB, 574 m->m_pkthdr.rcvif) 575 #else 576 NULL 577 #endif 578 ); 579 580 else 581 inp = (ipver == INP_IPV4 ? 582 in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src, 583 sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 584 : 585 #ifdef SIFTR_IPV6 586 in6_pcblookup(&V_tcbinfo, 587 &((struct ip6_hdr *)ip)->ip6_dst, dport, 588 &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB, 589 m->m_pkthdr.rcvif) 590 #else 591 NULL 592 #endif 593 ); 594 595 /* If we can't find the inpcb, bail. */ 596 if (inp == NULL) { 597 if (dir == PFIL_IN) 598 ss->nskip_in_inpcb++; 599 else 600 ss->nskip_out_inpcb++; 601 } 602 603 return (inp); 604 } 605 606 static inline uint32_t 607 siftr_get_flowid(struct inpcb *inp, int ipver, uint32_t *phashtype) 608 { 609 if (inp->inp_flowid == 0) { 610 #ifdef SIFTR_IPV6 611 if (ipver == INP_IPV6) { 612 return fib6_calc_packet_hash(&inp->in6p_laddr, 613 &inp->in6p_faddr, 614 inp->inp_lport, 615 inp->inp_fport, 616 IPPROTO_TCP, 617 phashtype); 618 } else 619 #endif 620 { 621 return fib4_calc_packet_hash(inp->inp_laddr, 622 inp->inp_faddr, 623 inp->inp_lport, 624 inp->inp_fport, 625 IPPROTO_TCP, 626 phashtype); 627 } 628 } else { 629 *phashtype = inp->inp_flowtype; 630 return inp->inp_flowid; 631 } 632 } 633 634 static inline void 635 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp, 636 int ipver, int dir, int inp_locally_locked) 637 { 638 pn->snd_cwnd = tp->snd_cwnd; 639 pn->snd_wnd = tp->snd_wnd; 640 pn->rcv_wnd = tp->rcv_wnd; 641 pn->t_flags2 = tp->t_flags2; 642 pn->snd_ssthresh = tp->snd_ssthresh; 643 pn->snd_scale = tp->snd_scale; 644 pn->rcv_scale = tp->rcv_scale; 645 pn->conn_state = tp->t_state; 646 pn->max_seg_size = tp->t_maxseg; 647 pn->srtt = ((uint64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT; 648 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0; 649 pn->flags = tp->t_flags; 650 pn->rto = tp->t_rxtcur * tick; 651 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat; 652 pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd); 653 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat; 654 pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv); 655 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una; 656 pn->t_segqlen = tp->t_segqlen; 657 658 /* We've finished accessing the tcb so release the lock. */ 659 if (inp_locally_locked) 660 INP_RUNLOCK(inp); 661 662 pn->direction = (dir == PFIL_IN ? DIR_IN : DIR_OUT); 663 664 /* 665 * Significantly more accurate than using getmicrotime(), but slower! 666 * Gives true microsecond resolution at the expense of a hit to 667 * maximum pps throughput processing when SIFTR is loaded and enabled. 668 */ 669 microtime(&pn->tval); 670 TCP_PROBE1(siftr, &pn); 671 } 672 673 /* 674 * pfil hook that is called for each IPv4 packet making its way through the 675 * stack in either direction. 676 * The pfil subsystem holds a non-sleepable mutex somewhere when 677 * calling our hook function, so we can't sleep at all. 678 * It's very important to use the M_NOWAIT flag with all function calls 679 * that support it so that they won't sleep, otherwise you get a panic. 680 */ 681 static pfil_return_t 682 siftr_chkpkt(struct mbuf **m, struct ifnet *ifp, int flags, 683 void *ruleset __unused, struct inpcb *inp) 684 { 685 struct pkt_node *pn; 686 struct ip *ip; 687 struct tcphdr *th; 688 struct tcpcb *tp; 689 struct siftr_stats *ss; 690 unsigned int ip_hl; 691 int inp_locally_locked, dir; 692 uint32_t hash_id, hash_type; 693 struct listhead *counter_list; 694 struct flow_hash_node *hash_node; 695 696 inp_locally_locked = 0; 697 dir = PFIL_DIR(flags); 698 ss = DPCPU_PTR(ss); 699 700 /* 701 * m_pullup is not required here because ip_{input|output} 702 * already do the heavy lifting for us. 703 */ 704 705 ip = mtod(*m, struct ip *); 706 707 /* Only continue processing if the packet is TCP. */ 708 if (ip->ip_p != IPPROTO_TCP) 709 goto ret; 710 711 /* 712 * Create a tcphdr struct starting at the correct offset 713 * in the IP packet. ip->ip_hl gives the ip header length 714 * in 4-byte words, so multiply it to get the size in bytes. 715 */ 716 ip_hl = (ip->ip_hl << 2); 717 th = (struct tcphdr *)((caddr_t)ip + ip_hl); 718 719 /* 720 * Only pkts selected by the tcp port filter 721 * can be inserted into the pkt_queue 722 */ 723 if ((siftr_port_filter != 0) && 724 (siftr_port_filter != ntohs(th->th_sport)) && 725 (siftr_port_filter != ntohs(th->th_dport))) { 726 goto ret; 727 } 728 729 /* 730 * If a kernel subsystem reinjects packets into the stack, our pfil 731 * hook will be called multiple times for the same packet. 732 * Make sure we only process unique packets. 733 */ 734 if (siftr_chkreinject(*m, dir, ss)) 735 goto ret; 736 737 if (dir == PFIL_IN) 738 ss->n_in++; 739 else 740 ss->n_out++; 741 742 /* 743 * If the pfil hooks don't provide a pointer to the 744 * inpcb, we need to find it ourselves and lock it. 745 */ 746 if (!inp) { 747 /* Find the corresponding inpcb for this pkt. */ 748 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport, 749 th->th_dport, dir, ss); 750 751 if (inp == NULL) 752 goto ret; 753 else 754 inp_locally_locked = 1; 755 } 756 757 INP_LOCK_ASSERT(inp); 758 759 /* Find the TCP control block that corresponds with this packet */ 760 tp = intotcpcb(inp); 761 762 /* 763 * If we can't find the TCP control block (happens occasionaly for a 764 * packet sent during the shutdown phase of a TCP connection), or the 765 * TCP control block has not initialized (happens during TCPS_SYN_SENT), 766 * bail. 767 */ 768 if (tp == NULL || tp->t_state < TCPS_ESTABLISHED) { 769 if (dir == PFIL_IN) 770 ss->nskip_in_tcpcb++; 771 else 772 ss->nskip_out_tcpcb++; 773 774 goto inp_unlock; 775 } 776 777 hash_id = siftr_get_flowid(inp, INP_IPV4, &hash_type); 778 counter_list = counter_hash + (hash_id & siftr_hashmask); 779 hash_node = siftr_find_flow(counter_list, hash_id); 780 781 /* If this flow hasn't been seen before, we create a new entry. */ 782 if (hash_node == NULL) { 783 struct flow_info info; 784 785 inet_ntoa_r(inp->inp_laddr, info.laddr); 786 inet_ntoa_r(inp->inp_faddr, info.faddr); 787 info.lport = ntohs(inp->inp_lport); 788 info.fport = ntohs(inp->inp_fport); 789 info.key = hash_id; 790 info.ipver = INP_IPV4; 791 792 hash_node = siftr_new_hash_node(info, dir, ss); 793 } 794 795 if (hash_node == NULL) { 796 goto inp_unlock; 797 } 798 799 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 800 801 if (pn == NULL) { 802 if (dir == PFIL_IN) 803 ss->nskip_in_malloc++; 804 else 805 ss->nskip_out_malloc++; 806 807 goto inp_unlock; 808 } 809 810 pn->flowid = hash_id; 811 pn->flowtype = hash_type; 812 813 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked); 814 815 mtx_lock(&siftr_pkt_queue_mtx); 816 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 817 mtx_unlock(&siftr_pkt_queue_mtx); 818 goto ret; 819 820 inp_unlock: 821 if (inp_locally_locked) 822 INP_RUNLOCK(inp); 823 824 ret: 825 return (PFIL_PASS); 826 } 827 828 #ifdef SIFTR_IPV6 829 static pfil_return_t 830 siftr_chkpkt6(struct mbuf **m, struct ifnet *ifp, int flags, 831 void *ruleset __unused, struct inpcb *inp) 832 { 833 struct pkt_node *pn; 834 struct ip6_hdr *ip6; 835 struct tcphdr *th; 836 struct tcpcb *tp; 837 struct siftr_stats *ss; 838 unsigned int ip6_hl; 839 int inp_locally_locked, dir; 840 uint32_t hash_id, hash_type; 841 struct listhead *counter_list; 842 struct flow_hash_node *hash_node; 843 844 inp_locally_locked = 0; 845 dir = PFIL_DIR(flags); 846 ss = DPCPU_PTR(ss); 847 848 /* 849 * m_pullup is not required here because ip6_{input|output} 850 * already do the heavy lifting for us. 851 */ 852 853 ip6 = mtod(*m, struct ip6_hdr *); 854 855 /* 856 * Only continue processing if the packet is TCP 857 * XXX: We should follow the next header fields 858 * as shown on Pg 6 RFC 2460, but right now we'll 859 * only check pkts that have no extension headers. 860 */ 861 if (ip6->ip6_nxt != IPPROTO_TCP) 862 goto ret6; 863 864 /* 865 * Create a tcphdr struct starting at the correct offset 866 * in the ipv6 packet. 867 */ 868 ip6_hl = sizeof(struct ip6_hdr); 869 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl); 870 871 /* 872 * Only pkts selected by the tcp port filter 873 * can be inserted into the pkt_queue 874 */ 875 if ((siftr_port_filter != 0) && 876 (siftr_port_filter != ntohs(th->th_sport)) && 877 (siftr_port_filter != ntohs(th->th_dport))) { 878 goto ret6; 879 } 880 881 /* 882 * If a kernel subsystem reinjects packets into the stack, our pfil 883 * hook will be called multiple times for the same packet. 884 * Make sure we only process unique packets. 885 */ 886 if (siftr_chkreinject(*m, dir, ss)) 887 goto ret6; 888 889 if (dir == PFIL_IN) 890 ss->n_in++; 891 else 892 ss->n_out++; 893 894 /* 895 * For inbound packets, the pfil hooks don't provide a pointer to the 896 * inpcb, so we need to find it ourselves and lock it. 897 */ 898 if (!inp) { 899 /* Find the corresponding inpcb for this pkt. */ 900 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m, 901 th->th_sport, th->th_dport, dir, ss); 902 903 if (inp == NULL) 904 goto ret6; 905 else 906 inp_locally_locked = 1; 907 } 908 909 /* Find the TCP control block that corresponds with this packet. */ 910 tp = intotcpcb(inp); 911 912 /* 913 * If we can't find the TCP control block (happens occasionaly for a 914 * packet sent during the shutdown phase of a TCP connection), or the 915 * TCP control block has not initialized (happens during TCPS_SYN_SENT), 916 * bail. 917 */ 918 if (tp == NULL || tp->t_state < TCPS_ESTABLISHED) { 919 if (dir == PFIL_IN) 920 ss->nskip_in_tcpcb++; 921 else 922 ss->nskip_out_tcpcb++; 923 924 goto inp_unlock6; 925 } 926 927 hash_id = siftr_get_flowid(inp, INP_IPV6, &hash_type); 928 counter_list = counter_hash + (hash_id & siftr_hashmask); 929 hash_node = siftr_find_flow(counter_list, hash_id); 930 931 /* If this flow hasn't been seen before, we create a new entry. */ 932 if (!hash_node) { 933 struct flow_info info; 934 935 ip6_sprintf(info.laddr, &inp->in6p_laddr); 936 ip6_sprintf(info.faddr, &inp->in6p_faddr); 937 info.lport = ntohs(inp->inp_lport); 938 info.fport = ntohs(inp->inp_fport); 939 info.key = hash_id; 940 info.ipver = INP_IPV6; 941 942 hash_node = siftr_new_hash_node(info, dir, ss); 943 } 944 945 if (!hash_node) { 946 goto inp_unlock6; 947 } 948 949 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 950 951 if (pn == NULL) { 952 if (dir == PFIL_IN) 953 ss->nskip_in_malloc++; 954 else 955 ss->nskip_out_malloc++; 956 957 goto inp_unlock6; 958 } 959 960 pn->flowid = hash_id; 961 pn->flowtype = hash_type; 962 963 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked); 964 965 mtx_lock(&siftr_pkt_queue_mtx); 966 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 967 mtx_unlock(&siftr_pkt_queue_mtx); 968 goto ret6; 969 970 inp_unlock6: 971 if (inp_locally_locked) 972 INP_RUNLOCK(inp); 973 974 ret6: 975 return (PFIL_PASS); 976 } 977 #endif /* #ifdef SIFTR_IPV6 */ 978 979 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet_hook); 980 #define V_siftr_inet_hook VNET(siftr_inet_hook) 981 #ifdef SIFTR_IPV6 982 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet6_hook); 983 #define V_siftr_inet6_hook VNET(siftr_inet6_hook) 984 #endif 985 static int 986 siftr_pfil(int action) 987 { 988 struct pfil_hook_args pha = { 989 .pa_version = PFIL_VERSION, 990 .pa_flags = PFIL_IN | PFIL_OUT, 991 .pa_modname = "siftr", 992 .pa_rulname = "default", 993 }; 994 struct pfil_link_args pla = { 995 .pa_version = PFIL_VERSION, 996 .pa_flags = PFIL_IN | PFIL_OUT | PFIL_HEADPTR | PFIL_HOOKPTR, 997 }; 998 999 VNET_ITERATOR_DECL(vnet_iter); 1000 1001 VNET_LIST_RLOCK(); 1002 VNET_FOREACH(vnet_iter) { 1003 CURVNET_SET(vnet_iter); 1004 1005 if (action == HOOK) { 1006 pha.pa_mbuf_chk = siftr_chkpkt; 1007 pha.pa_type = PFIL_TYPE_IP4; 1008 V_siftr_inet_hook = pfil_add_hook(&pha); 1009 pla.pa_hook = V_siftr_inet_hook; 1010 pla.pa_head = V_inet_pfil_head; 1011 (void)pfil_link(&pla); 1012 #ifdef SIFTR_IPV6 1013 pha.pa_mbuf_chk = siftr_chkpkt6; 1014 pha.pa_type = PFIL_TYPE_IP6; 1015 V_siftr_inet6_hook = pfil_add_hook(&pha); 1016 pla.pa_hook = V_siftr_inet6_hook; 1017 pla.pa_head = V_inet6_pfil_head; 1018 (void)pfil_link(&pla); 1019 #endif 1020 } else if (action == UNHOOK) { 1021 pfil_remove_hook(V_siftr_inet_hook); 1022 #ifdef SIFTR_IPV6 1023 pfil_remove_hook(V_siftr_inet6_hook); 1024 #endif 1025 } 1026 CURVNET_RESTORE(); 1027 } 1028 VNET_LIST_RUNLOCK(); 1029 1030 return (0); 1031 } 1032 1033 static int 1034 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS) 1035 { 1036 struct alq *new_alq; 1037 int error; 1038 1039 error = sysctl_handle_string(oidp, arg1, arg2, req); 1040 1041 /* Check for error or same filename */ 1042 if (error != 0 || req->newptr == NULL || 1043 strncmp(siftr_logfile, arg1, arg2) == 0) 1044 goto done; 1045 1046 /* file name changed */ 1047 error = alq_open(&new_alq, arg1, curthread->td_ucred, 1048 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1049 if (error != 0) 1050 goto done; 1051 1052 /* 1053 * If disabled, siftr_alq == NULL so we simply close 1054 * the alq as we've proved it can be opened. 1055 * If enabled, close the existing alq and switch the old 1056 * for the new. 1057 */ 1058 if (siftr_alq == NULL) { 1059 alq_close(new_alq); 1060 } else { 1061 alq_close(siftr_alq); 1062 siftr_alq = new_alq; 1063 } 1064 1065 /* Update filename upon success */ 1066 strlcpy(siftr_logfile, arg1, arg2); 1067 done: 1068 return (error); 1069 } 1070 1071 static int 1072 siftr_manage_ops(uint8_t action) 1073 { 1074 struct siftr_stats totalss; 1075 struct timeval tval; 1076 struct flow_hash_node *counter, *tmp_counter; 1077 struct sbuf *s; 1078 int i, error; 1079 uint32_t bytes_to_write, total_skipped_pkts; 1080 1081 error = 0; 1082 total_skipped_pkts = 0; 1083 1084 /* Init an autosizing sbuf that initially holds 200 chars. */ 1085 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL) 1086 return (-1); 1087 1088 if (action == SIFTR_ENABLE && siftr_pkt_manager_thr == NULL) { 1089 /* 1090 * Create our alq 1091 * XXX: We should abort if alq_open fails! 1092 */ 1093 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred, 1094 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1095 1096 STAILQ_INIT(&pkt_queue); 1097 1098 DPCPU_ZERO(ss); 1099 1100 siftr_exit_pkt_manager_thread = 0; 1101 1102 kthread_add(&siftr_pkt_manager_thread, NULL, NULL, 1103 &siftr_pkt_manager_thr, RFNOWAIT, 0, 1104 "siftr_pkt_manager_thr"); 1105 1106 siftr_pfil(HOOK); 1107 1108 microtime(&tval); 1109 1110 sbuf_printf(s, 1111 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t" 1112 "siftrver=%s\tsysname=%s\tsysver=%u\tipmode=%u\n", 1113 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, 1114 SYS_NAME, __FreeBSD_version, SIFTR_IPMODE); 1115 1116 sbuf_finish(s); 1117 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK); 1118 1119 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) { 1120 /* 1121 * Remove the pfil hook functions. All threads currently in 1122 * the hook functions are allowed to exit before siftr_pfil() 1123 * returns. 1124 */ 1125 siftr_pfil(UNHOOK); 1126 1127 /* This will block until the pkt manager thread unlocks it. */ 1128 mtx_lock(&siftr_pkt_mgr_mtx); 1129 1130 /* Tell the pkt manager thread that it should exit now. */ 1131 siftr_exit_pkt_manager_thread = 1; 1132 1133 /* 1134 * Wake the pkt_manager thread so it realises that 1135 * siftr_exit_pkt_manager_thread == 1 and exits gracefully. 1136 * The wakeup won't be delivered until we unlock 1137 * siftr_pkt_mgr_mtx so this isn't racy. 1138 */ 1139 wakeup(&wait_for_pkt); 1140 1141 /* Wait for the pkt_manager thread to exit. */ 1142 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT, 1143 "thrwait", 0); 1144 1145 siftr_pkt_manager_thr = NULL; 1146 mtx_unlock(&siftr_pkt_mgr_mtx); 1147 1148 totalss.n_in = DPCPU_VARSUM(ss, n_in); 1149 totalss.n_out = DPCPU_VARSUM(ss, n_out); 1150 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc); 1151 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc); 1152 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb); 1153 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb); 1154 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb); 1155 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb); 1156 1157 total_skipped_pkts = totalss.nskip_in_malloc + 1158 totalss.nskip_out_malloc + totalss.nskip_in_tcpcb + 1159 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb + 1160 totalss.nskip_out_inpcb; 1161 1162 microtime(&tval); 1163 1164 sbuf_printf(s, 1165 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t" 1166 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t" 1167 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t" 1168 "num_outbound_skipped_pkts_malloc=%u\t" 1169 "num_inbound_skipped_pkts_tcpcb=%u\t" 1170 "num_outbound_skipped_pkts_tcpcb=%u\t" 1171 "num_inbound_skipped_pkts_inpcb=%u\t" 1172 "num_outbound_skipped_pkts_inpcb=%u\t" 1173 "total_skipped_tcp_pkts=%u\tflow_list=", 1174 (intmax_t)tval.tv_sec, 1175 tval.tv_usec, 1176 (uintmax_t)totalss.n_in, 1177 (uintmax_t)totalss.n_out, 1178 (uintmax_t)(totalss.n_in + totalss.n_out), 1179 totalss.nskip_in_malloc, 1180 totalss.nskip_out_malloc, 1181 totalss.nskip_in_tcpcb, 1182 totalss.nskip_out_tcpcb, 1183 totalss.nskip_in_inpcb, 1184 totalss.nskip_out_inpcb, 1185 total_skipped_pkts); 1186 1187 /* 1188 * Iterate over the flow hash, printing a summary of each 1189 * flow seen and freeing any malloc'd memory. 1190 * The hash consists of an array of LISTs (man 3 queue). 1191 */ 1192 for (i = 0; i <= siftr_hashmask; i++) { 1193 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes, 1194 tmp_counter) { 1195 sbuf_printf(s, "%s;%hu-%s;%hu,", 1196 counter->const_info.laddr, 1197 counter->const_info.lport, 1198 counter->const_info.faddr, 1199 counter->const_info.fport); 1200 1201 free(counter, M_SIFTR_HASHNODE); 1202 } 1203 1204 LIST_INIT(counter_hash + i); 1205 } 1206 1207 sbuf_printf(s, "\n"); 1208 sbuf_finish(s); 1209 1210 i = 0; 1211 do { 1212 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i); 1213 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK); 1214 i += bytes_to_write; 1215 } while (i < sbuf_len(s)); 1216 1217 alq_close(siftr_alq); 1218 siftr_alq = NULL; 1219 } else 1220 error = EINVAL; 1221 1222 sbuf_delete(s); 1223 1224 /* 1225 * XXX: Should be using ret to check if any functions fail 1226 * and set error appropriately 1227 */ 1228 1229 return (error); 1230 } 1231 1232 static int 1233 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS) 1234 { 1235 int error; 1236 uint32_t new; 1237 1238 new = siftr_enabled; 1239 error = sysctl_handle_int(oidp, &new, 0, req); 1240 if (error == 0 && req->newptr != NULL) { 1241 if (new > 1) 1242 return (EINVAL); 1243 else if (new != siftr_enabled) { 1244 if ((error = siftr_manage_ops(new)) == 0) { 1245 siftr_enabled = new; 1246 } else { 1247 siftr_manage_ops(SIFTR_DISABLE); 1248 } 1249 } 1250 } 1251 1252 return (error); 1253 } 1254 1255 static void 1256 siftr_shutdown_handler(void *arg) 1257 { 1258 if (siftr_enabled == 1) { 1259 siftr_manage_ops(SIFTR_DISABLE); 1260 } 1261 } 1262 1263 /* 1264 * Module is being unloaded or machine is shutting down. Take care of cleanup. 1265 */ 1266 static int 1267 deinit_siftr(void) 1268 { 1269 /* Cleanup. */ 1270 siftr_manage_ops(SIFTR_DISABLE); 1271 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask); 1272 mtx_destroy(&siftr_pkt_queue_mtx); 1273 mtx_destroy(&siftr_pkt_mgr_mtx); 1274 1275 return (0); 1276 } 1277 1278 /* 1279 * Module has just been loaded into the kernel. 1280 */ 1281 static int 1282 init_siftr(void) 1283 { 1284 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL, 1285 SHUTDOWN_PRI_FIRST); 1286 1287 /* Initialise our flow counter hash table. */ 1288 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR, 1289 &siftr_hashmask); 1290 1291 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF); 1292 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF); 1293 1294 /* Print message to the user's current terminal. */ 1295 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n" 1296 " http://caia.swin.edu.au/urp/newtcp\n\n", 1297 MODVERSION_STR); 1298 1299 return (0); 1300 } 1301 1302 /* 1303 * This is the function that is called to load and unload the module. 1304 * When the module is loaded, this function is called once with 1305 * "what" == MOD_LOAD 1306 * When the module is unloaded, this function is called twice with 1307 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second 1308 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command, 1309 * this function is called once with "what" = MOD_SHUTDOWN 1310 * When the system is shut down, the handler isn't called until the very end 1311 * of the shutdown sequence i.e. after the disks have been synced. 1312 */ 1313 static int 1314 siftr_load_handler(module_t mod, int what, void *arg) 1315 { 1316 int ret; 1317 1318 switch (what) { 1319 case MOD_LOAD: 1320 ret = init_siftr(); 1321 break; 1322 1323 case MOD_QUIESCE: 1324 case MOD_SHUTDOWN: 1325 ret = deinit_siftr(); 1326 break; 1327 1328 case MOD_UNLOAD: 1329 ret = 0; 1330 break; 1331 1332 default: 1333 ret = EINVAL; 1334 break; 1335 } 1336 1337 return (ret); 1338 } 1339 1340 static moduledata_t siftr_mod = { 1341 .name = "siftr", 1342 .evhand = siftr_load_handler, 1343 }; 1344 1345 /* 1346 * Param 1: name of the kernel module 1347 * Param 2: moduledata_t struct containing info about the kernel module 1348 * and the execution entry point for the module 1349 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h 1350 * Defines the module initialisation order 1351 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h 1352 * Defines the initialisation order of this kld relative to others 1353 * within the same subsystem as defined by param 3 1354 */ 1355 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY); 1356 MODULE_DEPEND(siftr, alq, 1, 1, 1); 1357 MODULE_VERSION(siftr, MODVERSION); 1358