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/param.h> 64#include <sys/alq.h> 65#include <sys/errno.h> 66#include <sys/eventhandler.h> 67#include <sys/hash.h> 68#include <sys/kernel.h> 69#include <sys/kthread.h> 70#include <sys/lock.h> 71#include <sys/mbuf.h> 72#include <sys/module.h> 73#include <sys/mutex.h> 74#include <sys/pcpu.h> 75#include <sys/proc.h> 76#include <sys/reboot.h> 77#include <sys/sbuf.h> 78#include <sys/sdt.h> 79#include <sys/smp.h> 80#include <sys/socket.h> 81#include <sys/socketvar.h> 82#include <sys/sysctl.h> 83#include <sys/unistd.h> 84 85#include <net/if.h> 86#include <net/if_var.h> 87#include <net/pfil.h> 88#include <net/route.h> 89 90#include <netinet/in.h> 91#include <netinet/in_kdtrace.h> 92#include <netinet/in_fib.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/ip_var.h> 98#include <netinet/tcp_var.h> 99 100#ifdef SIFTR_IPV6 101#include <netinet/ip6.h> 102#include <netinet6/ip6_var.h> 103#include <netinet6/in6_fib.h> 104#include <netinet6/in6_pcb.h> 105#endif /* SIFTR_IPV6 */ 106 107#include <machine/in_cksum.h> 108 109/* 110 * Three digit version number refers to X.Y.Z where: 111 * X is the major version number 112 * Y is bumped to mark backwards incompatible changes 113 * Z is bumped to mark backwards compatible changes 114 */ 115#define V_MAJOR 1 116#define V_BACKBREAK 3 117#define V_BACKCOMPAT 0 118#define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT)) 119#define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \ 120 __XSTRING(V_BACKCOMPAT) 121 122#define HOOK 0 123#define UNHOOK 1 124#define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536 125#define SYS_NAME "FreeBSD" 126#define PACKET_TAG_SIFTR 100 127#define PACKET_COOKIE_SIFTR 21749576 128#define SIFTR_LOG_FILE_MODE 0644 129#define SIFTR_DISABLE 0 130#define SIFTR_ENABLE 1 131 132/* 133 * Hard upper limit on the length of log messages. Bump this up if you add new 134 * data fields such that the line length could exceed the below value. 135 */ 136#define MAX_LOG_MSG_LEN 300 137#define MAX_LOG_BATCH_SIZE 3 138/* XXX: Make this a sysctl tunable. */ 139#define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN) 140 141#ifdef SIFTR_IPV6 142#define SIFTR_IPMODE 6 143#else 144#define SIFTR_IPMODE 4 145#endif 146 147static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR"); 148static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode", 149 "SIFTR pkt_node struct"); 150static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode", 151 "SIFTR flow_hash_node struct"); 152 153/* Used as links in the pkt manager queue. */ 154struct pkt_node { 155 /* Timestamp of pkt as noted in the pfil hook. */ 156 struct timeval tval; 157 /* Direction pkt is travelling. */ 158 enum { 159 DIR_IN = 0, 160 DIR_OUT = 1, 161 } direction; 162 /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */ 163 uint8_t ipver; 164 /* Local TCP port. */ 165 uint16_t lport; 166 /* Foreign TCP port. */ 167 uint16_t fport; 168 /* Local address. */ 169 union in_dependaddr laddr; 170 /* Foreign address. */ 171 union in_dependaddr faddr; 172 /* Congestion Window (bytes). */ 173 uint32_t snd_cwnd; 174 /* Sending Window (bytes). */ 175 uint32_t snd_wnd; 176 /* Receive Window (bytes). */ 177 uint32_t rcv_wnd; 178 /* More tcpcb flags storage */ 179 uint32_t t_flags2; 180 /* Slow Start Threshold (bytes). */ 181 uint32_t snd_ssthresh; 182 /* Current state of the TCP FSM. */ 183 int conn_state; 184 /* Max Segment Size (bytes). */ 185 uint32_t mss; 186 /* Smoothed RTT (usecs). */ 187 uint32_t srtt; 188 /* Is SACK enabled? */ 189 u_char sack_enabled; 190 /* Window scaling for snd window. */ 191 u_char snd_scale; 192 /* Window scaling for recv window. */ 193 u_char rcv_scale; 194 /* TCP control block flags. */ 195 u_int t_flags; 196 /* Retransmission timeout (usec). */ 197 uint32_t rto; 198 /* Size of the TCP send buffer in bytes. */ 199 u_int snd_buf_hiwater; 200 /* Current num bytes in the send socket buffer. */ 201 u_int snd_buf_cc; 202 /* Size of the TCP receive buffer in bytes. */ 203 u_int rcv_buf_hiwater; 204 /* Current num bytes in the receive socket buffer. */ 205 u_int rcv_buf_cc; 206 /* Number of bytes inflight that we are waiting on ACKs for. */ 207 u_int sent_inflight_bytes; 208 /* Number of segments currently in the reassembly queue. */ 209 int t_segqlen; 210 /* Flowid for the connection. */ 211 u_int flowid; 212 /* Flow type for the connection. */ 213 u_int flowtype; 214 /* Link to next pkt_node in the list. */ 215 STAILQ_ENTRY(pkt_node) nodes; 216}; 217 218struct flow_info 219{ 220#ifdef SIFTR_IPV6 221 char laddr[INET6_ADDRSTRLEN]; /* local IP address */ 222 char faddr[INET6_ADDRSTRLEN]; /* foreign IP address */ 223#else 224 char laddr[INET_ADDRSTRLEN]; /* local IP address */ 225 char faddr[INET_ADDRSTRLEN]; /* foreign IP address */ 226#endif 227 uint16_t lport; /* local TCP port */ 228 uint16_t fport; /* foreign TCP port */ 229 uint32_t key; /* flowid of the connection */ 230}; 231 232struct flow_hash_node 233{ 234 uint16_t counter; 235 struct flow_info const_info; /* constant connection info */ 236 LIST_ENTRY(flow_hash_node) nodes; 237}; 238 239struct siftr_stats 240{ 241 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */ 242 uint64_t n_in; 243 uint64_t n_out; 244 /* # pkts skipped due to failed malloc calls. */ 245 uint32_t nskip_in_malloc; 246 uint32_t nskip_out_malloc; 247 /* # pkts skipped due to failed inpcb lookups. */ 248 uint32_t nskip_in_inpcb; 249 uint32_t nskip_out_inpcb; 250 /* # pkts skipped due to failed tcpcb lookups. */ 251 uint32_t nskip_in_tcpcb; 252 uint32_t nskip_out_tcpcb; 253 /* # pkts skipped due to stack reinjection. */ 254 uint32_t nskip_in_dejavu; 255 uint32_t nskip_out_dejavu; 256}; 257 258DPCPU_DEFINE_STATIC(struct siftr_stats, ss); 259 260static volatile unsigned int siftr_exit_pkt_manager_thread = 0; 261static unsigned int siftr_enabled = 0; 262static unsigned int siftr_pkts_per_log = 1; 263static uint16_t siftr_port_filter = 0; 264/* static unsigned int siftr_binary_log = 0; */ 265static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log"; 266static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log"; 267static u_long siftr_hashmask; 268STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue); 269LIST_HEAD(listhead, flow_hash_node) *counter_hash; 270static int wait_for_pkt; 271static struct alq *siftr_alq = NULL; 272static struct mtx siftr_pkt_queue_mtx; 273static struct mtx siftr_pkt_mgr_mtx; 274static struct thread *siftr_pkt_manager_thr = NULL; 275static char direction[2] = {'i','o'}; 276 277/* Required function prototypes. */ 278static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS); 279static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS); 280 281/* Declare the net.inet.siftr sysctl tree and populate it. */ 282 283SYSCTL_DECL(_net_inet_siftr); 284 285SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 286 "siftr related settings"); 287 288SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, 289 CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 290 &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU", 291 "switch siftr module operations on/off"); 292 293SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, 294 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &siftr_logfile_shadow, 295 sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler, "A", 296 "file to save siftr log messages to"); 297 298SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW, 299 &siftr_pkts_per_log, 1, 300 "number of packets between generating a log message"); 301 302SYSCTL_U16(_net_inet_siftr, OID_AUTO, port_filter, CTLFLAG_RW, 303 &siftr_port_filter, 0, 304 "enable packet filter on a TCP port"); 305 306/* XXX: TODO 307SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW, 308 &siftr_binary_log, 0, 309 "write log files in binary instead of ascii"); 310*/ 311 312/* Begin functions. */ 313 314static inline struct flow_hash_node * 315siftr_find_flow(struct listhead *counter_list, uint32_t id) 316{ 317 struct flow_hash_node *hash_node; 318 /* 319 * If the list is not empty i.e. the hash index has 320 * been used by another flow previously. 321 */ 322 if (LIST_FIRST(counter_list) != NULL) { 323 /* 324 * Loop through the hash nodes in the list. 325 * There should normally only be 1 hash node in the list. 326 */ 327 LIST_FOREACH(hash_node, counter_list, nodes) { 328 /* 329 * Check if the key for the pkt we are currently 330 * processing is the same as the key stored in the 331 * hash node we are currently processing. 332 * If they are the same, then we've found the 333 * hash node that stores the counter for the flow 334 * the pkt belongs to. 335 */ 336 if (hash_node->const_info.key == id) { 337 return hash_node; 338 } 339 } 340 } 341 342 return NULL; 343} 344 345static inline struct flow_hash_node * 346siftr_new_hash_node(struct flow_info info, int dir, 347 struct siftr_stats *ss) 348{ 349 struct flow_hash_node *hash_node; 350 struct listhead *counter_list; 351 352 counter_list = counter_hash + (info.key & siftr_hashmask); 353 /* Create a new hash node to store the flow's constant info. */ 354 hash_node = malloc(sizeof(struct flow_hash_node), M_SIFTR_HASHNODE, 355 M_NOWAIT|M_ZERO); 356 357 if (hash_node != NULL) { 358 /* Initialise our new hash node list entry. */ 359 hash_node->counter = 0; 360 hash_node->const_info = info; 361 LIST_INSERT_HEAD(counter_list, hash_node, nodes); 362 return hash_node; 363 } else { 364 /* malloc failed */ 365 if (dir == DIR_IN) 366 ss->nskip_in_malloc++; 367 else 368 ss->nskip_out_malloc++; 369 370 return NULL; 371 } 372} 373 374static int 375siftr_process_pkt(struct pkt_node * pkt_node, char *buf) 376{ 377 struct flow_hash_node *hash_node; 378 struct listhead *counter_list; 379 int ret_sz; 380 381 if (pkt_node->flowid == 0) { 382 panic("%s: flowid not available", __func__); 383 } 384 385 counter_list = counter_hash + (pkt_node->flowid & siftr_hashmask); 386 hash_node = siftr_find_flow(counter_list, pkt_node->flowid); 387 388 if (hash_node == NULL) { 389 return 0; 390 } else if (siftr_pkts_per_log > 1) { 391 /* 392 * Taking the remainder of the counter divided 393 * by the current value of siftr_pkts_per_log 394 * and storing that in counter provides a neat 395 * way to modulate the frequency of log 396 * messages being written to the log file. 397 */ 398 hash_node->counter = (hash_node->counter + 1) % 399 siftr_pkts_per_log; 400 /* 401 * If we have not seen enough packets since the last time 402 * we wrote a log message for this connection, return. 403 */ 404 if (hash_node->counter > 0) 405 return 0; 406 } 407 408 /* Construct a log message. */ 409 ret_sz = snprintf(buf, MAX_LOG_MSG_LEN, 410 "%c,%jd.%06ld,%s,%hu,%s,%hu,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u," 411 "%u,%u,%u,%u,%u,%u,%u,%u\n", 412 direction[pkt_node->direction], 413 (intmax_t)pkt_node->tval.tv_sec, 414 pkt_node->tval.tv_usec, 415 hash_node->const_info.laddr, 416 hash_node->const_info.lport, 417 hash_node->const_info.faddr, 418 hash_node->const_info.fport, 419 pkt_node->snd_ssthresh, 420 pkt_node->snd_cwnd, 421 pkt_node->t_flags2, 422 pkt_node->snd_wnd, 423 pkt_node->rcv_wnd, 424 pkt_node->snd_scale, 425 pkt_node->rcv_scale, 426 pkt_node->conn_state, 427 pkt_node->mss, 428 pkt_node->srtt, 429 pkt_node->sack_enabled, 430 pkt_node->t_flags, 431 pkt_node->rto, 432 pkt_node->snd_buf_hiwater, 433 pkt_node->snd_buf_cc, 434 pkt_node->rcv_buf_hiwater, 435 pkt_node->rcv_buf_cc, 436 pkt_node->sent_inflight_bytes, 437 pkt_node->t_segqlen, 438 pkt_node->flowid, 439 pkt_node->flowtype); 440 441 return ret_sz; 442} 443 444static void 445siftr_pkt_manager_thread(void *arg) 446{ 447 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue = 448 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue); 449 struct pkt_node *pkt_node; 450 uint8_t draining; 451 struct ale *log_buf; 452 int ret_sz, cnt = 0; 453 char *bufp; 454 455 draining = 2; 456 457 mtx_lock(&siftr_pkt_mgr_mtx); 458 459 /* draining == 0 when queue has been flushed and it's safe to exit. */ 460 while (draining) { 461 /* 462 * Sleep until we are signalled to wake because thread has 463 * been told to exit or until 1 tick has passed. 464 */ 465 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait", 466 1); 467 468 /* Gain exclusive access to the pkt_node queue. */ 469 mtx_lock(&siftr_pkt_queue_mtx); 470 471 /* 472 * Move pkt_queue to tmp_pkt_queue, which leaves 473 * pkt_queue empty and ready to receive more pkt_nodes. 474 */ 475 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue); 476 477 /* 478 * We've finished making changes to the list. Unlock it 479 * so the pfil hooks can continue queuing pkt_nodes. 480 */ 481 mtx_unlock(&siftr_pkt_queue_mtx); 482 483 /* 484 * We can't hold a mutex whilst calling siftr_process_pkt 485 * because ALQ might sleep waiting for buffer space. 486 */ 487 mtx_unlock(&siftr_pkt_mgr_mtx); 488 489 while ((pkt_node = STAILQ_FIRST(&tmp_pkt_queue)) != NULL) { 490 491 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN * 492 ((STAILQ_NEXT(pkt_node, nodes) != NULL) ? 493 MAX_LOG_BATCH_SIZE : 1), 494 ALQ_WAITOK); 495 496 if (log_buf != NULL) { 497 log_buf->ae_bytesused = 0; 498 bufp = log_buf->ae_data; 499 } else { 500 /* 501 * Should only happen if the ALQ is shutting 502 * down. 503 */ 504 bufp = NULL; 505 } 506 507 /* Flush all pkt_nodes to the log file. */ 508 STAILQ_FOREACH(pkt_node, &tmp_pkt_queue, nodes) { 509 if (log_buf != NULL) { 510 ret_sz = siftr_process_pkt(pkt_node, 511 bufp); 512 bufp += ret_sz; 513 log_buf->ae_bytesused += ret_sz; 514 } 515 if (++cnt >= MAX_LOG_BATCH_SIZE) 516 break; 517 } 518 if (log_buf != NULL) { 519 alq_post_flags(siftr_alq, log_buf, 0); 520 } 521 for (;cnt > 0; cnt--) { 522 pkt_node = STAILQ_FIRST(&tmp_pkt_queue); 523 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes); 524 free(pkt_node, M_SIFTR_PKTNODE); 525 } 526 } 527 528 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue), 529 ("SIFTR tmp_pkt_queue not empty after flush")); 530 531 mtx_lock(&siftr_pkt_mgr_mtx); 532 533 /* 534 * If siftr_exit_pkt_manager_thread gets set during the window 535 * where we are draining the tmp_pkt_queue above, there might 536 * still be pkts in pkt_queue that need to be drained. 537 * Allow one further iteration to occur after 538 * siftr_exit_pkt_manager_thread has been set to ensure 539 * pkt_queue is completely empty before we kill the thread. 540 * 541 * siftr_exit_pkt_manager_thread is set only after the pfil 542 * hooks have been removed, so only 1 extra iteration 543 * is needed to drain the queue. 544 */ 545 if (siftr_exit_pkt_manager_thread) 546 draining--; 547 } 548 549 mtx_unlock(&siftr_pkt_mgr_mtx); 550 551 /* Calls wakeup on this thread's struct thread ptr. */ 552 kthread_exit(); 553} 554 555/* 556 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that 557 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return. 558 * Return value >0 means the caller should skip processing this mbuf. 559 */ 560static inline int 561siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss) 562{ 563 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL) 564 != NULL) { 565 if (dir == PFIL_IN) 566 ss->nskip_in_dejavu++; 567 else 568 ss->nskip_out_dejavu++; 569 570 return (1); 571 } else { 572 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR, 573 PACKET_TAG_SIFTR, 0, M_NOWAIT); 574 if (tag == NULL) { 575 if (dir == PFIL_IN) 576 ss->nskip_in_malloc++; 577 else 578 ss->nskip_out_malloc++; 579 580 return (1); 581 } 582 583 m_tag_prepend(m, tag); 584 } 585 586 return (0); 587} 588 589/* 590 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL 591 * otherwise. 592 */ 593static inline struct inpcb * 594siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport, 595 uint16_t dport, int dir, struct siftr_stats *ss) 596{ 597 struct inpcb *inp; 598 599 /* We need the tcbinfo lock. */ 600 INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo); 601 602 if (dir == PFIL_IN) 603 inp = (ipver == INP_IPV4 ? 604 in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst, 605 dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 606 : 607#ifdef SIFTR_IPV6 608 in6_pcblookup(&V_tcbinfo, 609 &((struct ip6_hdr *)ip)->ip6_src, sport, 610 &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB, 611 m->m_pkthdr.rcvif) 612#else 613 NULL 614#endif 615 ); 616 617 else 618 inp = (ipver == INP_IPV4 ? 619 in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src, 620 sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 621 : 622#ifdef SIFTR_IPV6 623 in6_pcblookup(&V_tcbinfo, 624 &((struct ip6_hdr *)ip)->ip6_dst, dport, 625 &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB, 626 m->m_pkthdr.rcvif) 627#else 628 NULL 629#endif 630 ); 631 632 /* If we can't find the inpcb, bail. */ 633 if (inp == NULL) { 634 if (dir == PFIL_IN) 635 ss->nskip_in_inpcb++; 636 else 637 ss->nskip_out_inpcb++; 638 } 639 640 return (inp); 641} 642 643static inline uint32_t 644siftr_get_flowid(struct inpcb *inp, int ipver, uint32_t *phashtype) 645{ 646 if (inp->inp_flowid == 0) { 647#ifdef SIFTR_IPV6 648 if (ipver == INP_IPV6) { 649 return fib6_calc_packet_hash(&inp->in6p_laddr, 650 &inp->in6p_faddr, 651 inp->inp_lport, 652 inp->inp_fport, 653 IPPROTO_TCP, 654 phashtype); 655 } else 656#endif 657 { 658 return fib4_calc_packet_hash(inp->inp_laddr, 659 inp->inp_faddr, 660 inp->inp_lport, 661 inp->inp_fport, 662 IPPROTO_TCP, 663 phashtype); 664 } 665 } else { 666 *phashtype = inp->inp_flowtype; 667 return inp->inp_flowid; 668 } 669} 670 671static inline void 672siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp, 673 int ipver, int dir, int inp_locally_locked) 674{ 675 pn->ipver = ipver; 676 pn->lport = inp->inp_lport; 677 pn->fport = inp->inp_fport; 678 pn->laddr = inp->inp_inc.inc_ie.ie_dependladdr; 679 pn->faddr = inp->inp_inc.inc_ie.ie_dependfaddr; 680 pn->snd_cwnd = tp->snd_cwnd; 681 pn->snd_wnd = tp->snd_wnd; 682 pn->rcv_wnd = tp->rcv_wnd; 683 pn->t_flags2 = tp->t_flags2; 684 pn->snd_ssthresh = tp->snd_ssthresh; 685 pn->snd_scale = tp->snd_scale; 686 pn->rcv_scale = tp->rcv_scale; 687 pn->conn_state = tp->t_state; 688 pn->mss = tp->t_maxseg; 689 pn->srtt = ((uint64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT; 690 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0; 691 pn->t_flags = tp->t_flags; 692 pn->rto = tp->t_rxtcur * tick; 693 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat; 694 pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd); 695 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat; 696 pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv); 697 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una; 698 pn->t_segqlen = tp->t_segqlen; 699 700 /* We've finished accessing the tcb so release the lock. */ 701 if (inp_locally_locked) 702 INP_RUNLOCK(inp); 703 704 pn->direction = (dir == PFIL_IN ? DIR_IN : DIR_OUT); 705 706 /* 707 * Significantly more accurate than using getmicrotime(), but slower! 708 * Gives true microsecond resolution at the expense of a hit to 709 * maximum pps throughput processing when SIFTR is loaded and enabled. 710 */ 711 microtime(&pn->tval); 712 TCP_PROBE1(siftr, pn); 713} 714 715/* 716 * pfil hook that is called for each IPv4 packet making its way through the 717 * stack in either direction. 718 * The pfil subsystem holds a non-sleepable mutex somewhere when 719 * calling our hook function, so we can't sleep at all. 720 * It's very important to use the M_NOWAIT flag with all function calls 721 * that support it so that they won't sleep, otherwise you get a panic. 722 */ 723static pfil_return_t 724siftr_chkpkt(struct mbuf **m, struct ifnet *ifp, int flags, 725 void *ruleset __unused, struct inpcb *inp) 726{ 727 struct pkt_node *pn; 728 struct ip *ip; 729 struct tcphdr *th; 730 struct tcpcb *tp; 731 struct siftr_stats *ss; 732 unsigned int ip_hl; 733 int inp_locally_locked, dir; 734 uint32_t hash_id, hash_type; 735 struct listhead *counter_list; 736 struct flow_hash_node *hash_node; 737 738 inp_locally_locked = 0; 739 dir = PFIL_DIR(flags); 740 ss = DPCPU_PTR(ss); 741 742 /* 743 * m_pullup is not required here because ip_{input|output} 744 * already do the heavy lifting for us. 745 */ 746 747 ip = mtod(*m, struct ip *); 748 749 /* Only continue processing if the packet is TCP. */ 750 if (ip->ip_p != IPPROTO_TCP) 751 goto ret; 752 753 /* 754 * Create a tcphdr struct starting at the correct offset 755 * in the IP packet. ip->ip_hl gives the ip header length 756 * in 4-byte words, so multiply it to get the size in bytes. 757 */ 758 ip_hl = (ip->ip_hl << 2); 759 th = (struct tcphdr *)((caddr_t)ip + ip_hl); 760 761 /* 762 * Only pkts selected by the tcp port filter 763 * can be inserted into the pkt_queue 764 */ 765 if ((siftr_port_filter != 0) && 766 (siftr_port_filter != ntohs(th->th_sport)) && 767 (siftr_port_filter != ntohs(th->th_dport))) { 768 goto ret; 769 } 770 771 /* 772 * If a kernel subsystem reinjects packets into the stack, our pfil 773 * hook will be called multiple times for the same packet. 774 * Make sure we only process unique packets. 775 */ 776 if (siftr_chkreinject(*m, dir, ss)) 777 goto ret; 778 779 if (dir == PFIL_IN) 780 ss->n_in++; 781 else 782 ss->n_out++; 783 784 /* 785 * If the pfil hooks don't provide a pointer to the 786 * inpcb, we need to find it ourselves and lock it. 787 */ 788 if (!inp) { 789 /* Find the corresponding inpcb for this pkt. */ 790 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport, 791 th->th_dport, dir, ss); 792 793 if (inp == NULL) 794 goto ret; 795 else 796 inp_locally_locked = 1; 797 } 798 799 INP_LOCK_ASSERT(inp); 800 801 /* Find the TCP control block that corresponds with this packet */ 802 tp = intotcpcb(inp); 803 804 /* 805 * If we can't find the TCP control block (happens occasionaly for a 806 * packet sent during the shutdown phase of a TCP connection), or the 807 * TCP control block has not initialized (happens during TCPS_SYN_SENT), 808 * bail. 809 */ 810 if (tp == NULL || tp->t_state < TCPS_ESTABLISHED) { 811 if (dir == PFIL_IN) 812 ss->nskip_in_tcpcb++; 813 else 814 ss->nskip_out_tcpcb++; 815 816 goto inp_unlock; 817 } 818 819 hash_id = siftr_get_flowid(inp, INP_IPV4, &hash_type); 820 counter_list = counter_hash + (hash_id & siftr_hashmask); 821 hash_node = siftr_find_flow(counter_list, hash_id); 822 823 /* If this flow hasn't been seen before, we create a new entry. */ 824 if (hash_node == NULL) { 825 struct flow_info info; 826 827 inet_ntoa_r(inp->inp_laddr, info.laddr); 828 inet_ntoa_r(inp->inp_faddr, info.faddr); 829 info.lport = ntohs(inp->inp_lport); 830 info.fport = ntohs(inp->inp_fport); 831 info.key = hash_id; 832 833 hash_node = siftr_new_hash_node(info, dir, ss); 834 } 835 836 if (hash_node == NULL) { 837 goto inp_unlock; 838 } 839 840 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 841 842 if (pn == NULL) { 843 if (dir == PFIL_IN) 844 ss->nskip_in_malloc++; 845 else 846 ss->nskip_out_malloc++; 847 848 goto inp_unlock; 849 } 850 851 pn->flowid = hash_id; 852 pn->flowtype = hash_type; 853 854 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked); 855 856 mtx_lock(&siftr_pkt_queue_mtx); 857 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 858 mtx_unlock(&siftr_pkt_queue_mtx); 859 goto ret; 860 861inp_unlock: 862 if (inp_locally_locked) 863 INP_RUNLOCK(inp); 864 865ret: 866 return (PFIL_PASS); 867} 868 869#ifdef SIFTR_IPV6 870static pfil_return_t 871siftr_chkpkt6(struct mbuf **m, struct ifnet *ifp, int flags, 872 void *ruleset __unused, struct inpcb *inp) 873{ 874 struct pkt_node *pn; 875 struct ip6_hdr *ip6; 876 struct tcphdr *th; 877 struct tcpcb *tp; 878 struct siftr_stats *ss; 879 unsigned int ip6_hl; 880 int inp_locally_locked, dir; 881 uint32_t hash_id, hash_type; 882 struct listhead *counter_list; 883 struct flow_hash_node *hash_node; 884 885 inp_locally_locked = 0; 886 dir = PFIL_DIR(flags); 887 ss = DPCPU_PTR(ss); 888 889 /* 890 * m_pullup is not required here because ip6_{input|output} 891 * already do the heavy lifting for us. 892 */ 893 894 ip6 = mtod(*m, struct ip6_hdr *); 895 896 /* 897 * Only continue processing if the packet is TCP 898 * XXX: We should follow the next header fields 899 * as shown on Pg 6 RFC 2460, but right now we'll 900 * only check pkts that have no extension headers. 901 */ 902 if (ip6->ip6_nxt != IPPROTO_TCP) 903 goto ret6; 904 905 /* 906 * Create a tcphdr struct starting at the correct offset 907 * in the ipv6 packet. 908 */ 909 ip6_hl = sizeof(struct ip6_hdr); 910 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl); 911 912 /* 913 * Only pkts selected by the tcp port filter 914 * can be inserted into the pkt_queue 915 */ 916 if ((siftr_port_filter != 0) && 917 (siftr_port_filter != ntohs(th->th_sport)) && 918 (siftr_port_filter != ntohs(th->th_dport))) { 919 goto ret6; 920 } 921 922 /* 923 * If a kernel subsystem reinjects packets into the stack, our pfil 924 * hook will be called multiple times for the same packet. 925 * Make sure we only process unique packets. 926 */ 927 if (siftr_chkreinject(*m, dir, ss)) 928 goto ret6; 929 930 if (dir == PFIL_IN) 931 ss->n_in++; 932 else 933 ss->n_out++; 934 935 /* 936 * For inbound packets, the pfil hooks don't provide a pointer to the 937 * inpcb, so we need to find it ourselves and lock it. 938 */ 939 if (!inp) { 940 /* Find the corresponding inpcb for this pkt. */ 941 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m, 942 th->th_sport, th->th_dport, dir, ss); 943 944 if (inp == NULL) 945 goto ret6; 946 else 947 inp_locally_locked = 1; 948 } 949 950 /* Find the TCP control block that corresponds with this packet. */ 951 tp = intotcpcb(inp); 952 953 /* 954 * If we can't find the TCP control block (happens occasionaly for a 955 * packet sent during the shutdown phase of a TCP connection), or the 956 * TCP control block has not initialized (happens during TCPS_SYN_SENT), 957 * bail. 958 */ 959 if (tp == NULL || tp->t_state < TCPS_ESTABLISHED) { 960 if (dir == PFIL_IN) 961 ss->nskip_in_tcpcb++; 962 else 963 ss->nskip_out_tcpcb++; 964 965 goto inp_unlock6; 966 } 967 968 hash_id = siftr_get_flowid(inp, INP_IPV6, &hash_type); 969 counter_list = counter_hash + (hash_id & siftr_hashmask); 970 hash_node = siftr_find_flow(counter_list, hash_id); 971 972 /* If this flow hasn't been seen before, we create a new entry. */ 973 if (!hash_node) { 974 struct flow_info info; 975 976 ip6_sprintf(info.laddr, &inp->in6p_laddr); 977 ip6_sprintf(info.faddr, &inp->in6p_faddr); 978 info.lport = ntohs(inp->inp_lport); 979 info.fport = ntohs(inp->inp_fport); 980 info.key = hash_id; 981 982 hash_node = siftr_new_hash_node(info, dir, ss); 983 } 984 985 if (!hash_node) { 986 goto inp_unlock6; 987 } 988 989 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 990 991 if (pn == NULL) { 992 if (dir == PFIL_IN) 993 ss->nskip_in_malloc++; 994 else 995 ss->nskip_out_malloc++; 996 997 goto inp_unlock6; 998 } 999 1000 pn->flowid = hash_id; 1001 pn->flowtype = hash_type; 1002 1003 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked); 1004 1005 mtx_lock(&siftr_pkt_queue_mtx); 1006 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 1007 mtx_unlock(&siftr_pkt_queue_mtx); 1008 goto ret6; 1009 1010inp_unlock6: 1011 if (inp_locally_locked) 1012 INP_RUNLOCK(inp); 1013 1014ret6: 1015 return (PFIL_PASS); 1016} 1017#endif /* #ifdef SIFTR_IPV6 */ 1018 1019VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet_hook); 1020#define V_siftr_inet_hook VNET(siftr_inet_hook) 1021#ifdef SIFTR_IPV6 1022VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet6_hook); 1023#define V_siftr_inet6_hook VNET(siftr_inet6_hook) 1024#endif 1025static int 1026siftr_pfil(int action) 1027{ 1028 struct pfil_hook_args pha = { 1029 .pa_version = PFIL_VERSION, 1030 .pa_flags = PFIL_IN | PFIL_OUT, 1031 .pa_modname = "siftr", 1032 .pa_rulname = "default", 1033 }; 1034 struct pfil_link_args pla = { 1035 .pa_version = PFIL_VERSION, 1036 .pa_flags = PFIL_IN | PFIL_OUT | PFIL_HEADPTR | PFIL_HOOKPTR, 1037 }; 1038 1039 VNET_ITERATOR_DECL(vnet_iter); 1040 1041 VNET_LIST_RLOCK(); 1042 VNET_FOREACH(vnet_iter) { 1043 CURVNET_SET(vnet_iter); 1044 1045 if (action == HOOK) { 1046 pha.pa_mbuf_chk = siftr_chkpkt; 1047 pha.pa_type = PFIL_TYPE_IP4; 1048 V_siftr_inet_hook = pfil_add_hook(&pha); 1049 pla.pa_hook = V_siftr_inet_hook; 1050 pla.pa_head = V_inet_pfil_head; 1051 (void)pfil_link(&pla); 1052#ifdef SIFTR_IPV6 1053 pha.pa_mbuf_chk = siftr_chkpkt6; 1054 pha.pa_type = PFIL_TYPE_IP6; 1055 V_siftr_inet6_hook = pfil_add_hook(&pha); 1056 pla.pa_hook = V_siftr_inet6_hook; 1057 pla.pa_head = V_inet6_pfil_head; 1058 (void)pfil_link(&pla); 1059#endif 1060 } else if (action == UNHOOK) { 1061 pfil_remove_hook(V_siftr_inet_hook); 1062#ifdef SIFTR_IPV6 1063 pfil_remove_hook(V_siftr_inet6_hook); 1064#endif 1065 } 1066 CURVNET_RESTORE(); 1067 } 1068 VNET_LIST_RUNLOCK(); 1069 1070 return (0); 1071} 1072 1073static int 1074siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS) 1075{ 1076 struct alq *new_alq; 1077 int error; 1078 1079 error = sysctl_handle_string(oidp, arg1, arg2, req); 1080 1081 /* Check for error or same filename */ 1082 if (error != 0 || req->newptr == NULL || 1083 strncmp(siftr_logfile, arg1, arg2) == 0) 1084 goto done; 1085 1086 /* file name changed */ 1087 error = alq_open(&new_alq, arg1, curthread->td_ucred, 1088 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1089 if (error != 0) 1090 goto done; 1091 1092 /* 1093 * If disabled, siftr_alq == NULL so we simply close 1094 * the alq as we've proved it can be opened. 1095 * If enabled, close the existing alq and switch the old 1096 * for the new. 1097 */ 1098 if (siftr_alq == NULL) { 1099 alq_close(new_alq); 1100 } else { 1101 alq_close(siftr_alq); 1102 siftr_alq = new_alq; 1103 } 1104 1105 /* Update filename upon success */ 1106 strlcpy(siftr_logfile, arg1, arg2); 1107done: 1108 return (error); 1109} 1110 1111static int 1112siftr_manage_ops(uint8_t action) 1113{ 1114 struct siftr_stats totalss; 1115 struct timeval tval; 1116 struct flow_hash_node *counter, *tmp_counter; 1117 struct sbuf *s; 1118 int i, error; 1119 uint32_t bytes_to_write, total_skipped_pkts; 1120 1121 error = 0; 1122 total_skipped_pkts = 0; 1123 1124 /* Init an autosizing sbuf that initially holds 200 chars. */ 1125 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL) 1126 return (-1); 1127 1128 if (action == SIFTR_ENABLE && siftr_pkt_manager_thr == NULL) { 1129 /* 1130 * Create our alq 1131 * XXX: We should abort if alq_open fails! 1132 */ 1133 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred, 1134 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1135 1136 STAILQ_INIT(&pkt_queue); 1137 1138 DPCPU_ZERO(ss); 1139 1140 siftr_exit_pkt_manager_thread = 0; 1141 1142 kthread_add(&siftr_pkt_manager_thread, NULL, NULL, 1143 &siftr_pkt_manager_thr, RFNOWAIT, 0, 1144 "siftr_pkt_manager_thr"); 1145 1146 siftr_pfil(HOOK); 1147 1148 microtime(&tval); 1149 1150 sbuf_printf(s, 1151 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t" 1152 "siftrver=%s\tsysname=%s\tsysver=%u\tipmode=%u\n", 1153 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, 1154 SYS_NAME, __FreeBSD_version, SIFTR_IPMODE); 1155 1156 sbuf_finish(s); 1157 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK); 1158 1159 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) { 1160 /* 1161 * Remove the pfil hook functions. All threads currently in 1162 * the hook functions are allowed to exit before siftr_pfil() 1163 * returns. 1164 */ 1165 siftr_pfil(UNHOOK); 1166 1167 /* This will block until the pkt manager thread unlocks it. */ 1168 mtx_lock(&siftr_pkt_mgr_mtx); 1169 1170 /* Tell the pkt manager thread that it should exit now. */ 1171 siftr_exit_pkt_manager_thread = 1; 1172 1173 /* 1174 * Wake the pkt_manager thread so it realises that 1175 * siftr_exit_pkt_manager_thread == 1 and exits gracefully. 1176 * The wakeup won't be delivered until we unlock 1177 * siftr_pkt_mgr_mtx so this isn't racy. 1178 */ 1179 wakeup(&wait_for_pkt); 1180 1181 /* Wait for the pkt_manager thread to exit. */ 1182 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT, 1183 "thrwait", 0); 1184 1185 siftr_pkt_manager_thr = NULL; 1186 mtx_unlock(&siftr_pkt_mgr_mtx); 1187 1188 totalss.n_in = DPCPU_VARSUM(ss, n_in); 1189 totalss.n_out = DPCPU_VARSUM(ss, n_out); 1190 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc); 1191 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc); 1192 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb); 1193 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb); 1194 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb); 1195 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb); 1196 1197 total_skipped_pkts = totalss.nskip_in_malloc + 1198 totalss.nskip_out_malloc + totalss.nskip_in_tcpcb + 1199 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb + 1200 totalss.nskip_out_inpcb; 1201 1202 microtime(&tval); 1203 1204 sbuf_printf(s, 1205 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t" 1206 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t" 1207 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t" 1208 "num_outbound_skipped_pkts_malloc=%u\t" 1209 "num_inbound_skipped_pkts_tcpcb=%u\t" 1210 "num_outbound_skipped_pkts_tcpcb=%u\t" 1211 "num_inbound_skipped_pkts_inpcb=%u\t" 1212 "num_outbound_skipped_pkts_inpcb=%u\t" 1213 "total_skipped_tcp_pkts=%u\tflow_list=", 1214 (intmax_t)tval.tv_sec, 1215 tval.tv_usec, 1216 (uintmax_t)totalss.n_in, 1217 (uintmax_t)totalss.n_out, 1218 (uintmax_t)(totalss.n_in + totalss.n_out), 1219 totalss.nskip_in_malloc, 1220 totalss.nskip_out_malloc, 1221 totalss.nskip_in_tcpcb, 1222 totalss.nskip_out_tcpcb, 1223 totalss.nskip_in_inpcb, 1224 totalss.nskip_out_inpcb, 1225 total_skipped_pkts); 1226 1227 /* 1228 * Iterate over the flow hash, printing a summary of each 1229 * flow seen and freeing any malloc'd memory. 1230 * The hash consists of an array of LISTs (man 3 queue). 1231 */ 1232 for (i = 0; i <= siftr_hashmask; i++) { 1233 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes, 1234 tmp_counter) { 1235 sbuf_printf(s, "%s;%hu-%s;%hu,", 1236 counter->const_info.laddr, 1237 counter->const_info.lport, 1238 counter->const_info.faddr, 1239 counter->const_info.fport); 1240 1241 free(counter, M_SIFTR_HASHNODE); 1242 } 1243 1244 LIST_INIT(counter_hash + i); 1245 } 1246 1247 sbuf_printf(s, "\n"); 1248 sbuf_finish(s); 1249 1250 i = 0; 1251 do { 1252 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i); 1253 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK); 1254 i += bytes_to_write; 1255 } while (i < sbuf_len(s)); 1256 1257 alq_close(siftr_alq); 1258 siftr_alq = NULL; 1259 } else 1260 error = EINVAL; 1261 1262 sbuf_delete(s); 1263 1264 /* 1265 * XXX: Should be using ret to check if any functions fail 1266 * and set error appropriately 1267 */ 1268 1269 return (error); 1270} 1271 1272static int 1273siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS) 1274{ 1275 int error; 1276 uint32_t new; 1277 1278 new = siftr_enabled; 1279 error = sysctl_handle_int(oidp, &new, 0, req); 1280 if (error == 0 && req->newptr != NULL) { 1281 if (new > 1) 1282 return (EINVAL); 1283 else if (new != siftr_enabled) { 1284 if ((error = siftr_manage_ops(new)) == 0) { 1285 siftr_enabled = new; 1286 } else { 1287 siftr_manage_ops(SIFTR_DISABLE); 1288 } 1289 } 1290 } 1291 1292 return (error); 1293} 1294 1295static void 1296siftr_shutdown_handler(void *arg, int howto) 1297{ 1298 if ((howto & RB_NOSYNC) != 0 || SCHEDULER_STOPPED()) 1299 return; 1300 1301 if (siftr_enabled == 1) { 1302 siftr_manage_ops(SIFTR_DISABLE); 1303 } 1304} 1305 1306/* 1307 * Module is being unloaded or machine is shutting down. Take care of cleanup. 1308 */ 1309static int 1310deinit_siftr(void) 1311{ 1312 /* Cleanup. */ 1313 siftr_manage_ops(SIFTR_DISABLE); 1314 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask); 1315 mtx_destroy(&siftr_pkt_queue_mtx); 1316 mtx_destroy(&siftr_pkt_mgr_mtx); 1317 1318 return (0); 1319} 1320 1321/* 1322 * Module has just been loaded into the kernel. 1323 */ 1324static int 1325init_siftr(void) 1326{ 1327 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL, 1328 SHUTDOWN_PRI_FIRST); 1329 1330 /* Initialise our flow counter hash table. */ 1331 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR, 1332 &siftr_hashmask); 1333 1334 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF); 1335 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF); 1336 1337 /* Print message to the user's current terminal. */ 1338 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n" 1339 " http://caia.swin.edu.au/urp/newtcp\n\n", 1340 MODVERSION_STR); 1341 1342 return (0); 1343} 1344 1345/* 1346 * This is the function that is called to load and unload the module. 1347 * When the module is loaded, this function is called once with 1348 * "what" == MOD_LOAD 1349 * When the module is unloaded, this function is called twice with 1350 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second 1351 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command, 1352 * this function is called once with "what" = MOD_SHUTDOWN 1353 * When the system is shut down, the handler isn't called until the very end 1354 * of the shutdown sequence i.e. after the disks have been synced. 1355 */ 1356static int 1357siftr_load_handler(module_t mod, int what, void *arg) 1358{ 1359 int ret; 1360 1361 switch (what) { 1362 case MOD_LOAD: 1363 ret = init_siftr(); 1364 break; 1365 1366 case MOD_QUIESCE: 1367 case MOD_SHUTDOWN: 1368 ret = deinit_siftr(); 1369 break; 1370 1371 case MOD_UNLOAD: 1372 ret = 0; 1373 break; 1374 1375 default: 1376 ret = EINVAL; 1377 break; 1378 } 1379 1380 return (ret); 1381} 1382 1383static moduledata_t siftr_mod = { 1384 .name = "siftr", 1385 .evhand = siftr_load_handler, 1386}; 1387 1388/* 1389 * Param 1: name of the kernel module 1390 * Param 2: moduledata_t struct containing info about the kernel module 1391 * and the execution entry point for the module 1392 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h 1393 * Defines the module initialisation order 1394 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h 1395 * Defines the initialisation order of this kld relative to others 1396 * within the same subsystem as defined by param 3 1397 */ 1398DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY); 1399MODULE_DEPEND(siftr, alq, 1, 1, 1); 1400MODULE_VERSION(siftr, MODVERSION); 1401