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 #include <sys/param.h> 65 #include <sys/alq.h> 66 #include <sys/errno.h> 67 #include <sys/eventhandler.h> 68 #include <sys/hash.h> 69 #include <sys/kernel.h> 70 #include <sys/kthread.h> 71 #include <sys/lock.h> 72 #include <sys/mbuf.h> 73 #include <sys/module.h> 74 #include <sys/mutex.h> 75 #include <sys/pcpu.h> 76 #include <sys/proc.h> 77 #include <sys/reboot.h> 78 #include <sys/sbuf.h> 79 #include <sys/sdt.h> 80 #include <sys/smp.h> 81 #include <sys/socket.h> 82 #include <sys/socketvar.h> 83 #include <sys/sysctl.h> 84 #include <sys/unistd.h> 85 86 #include <net/if.h> 87 #include <net/if_var.h> 88 #include <net/pfil.h> 89 #include <net/route.h> 90 91 #include <netinet/in.h> 92 #include <netinet/in_kdtrace.h> 93 #include <netinet/in_fib.h> 94 #include <netinet/in_pcb.h> 95 #include <netinet/in_systm.h> 96 #include <netinet/in_var.h> 97 #include <netinet/ip.h> 98 #include <netinet/ip_var.h> 99 #include <netinet/tcp_var.h> 100 101 #ifdef SIFTR_IPV6 102 #include <netinet/ip6.h> 103 #include <netinet6/ip6_var.h> 104 #include <netinet6/in6_fib.h> 105 #include <netinet6/in6_pcb.h> 106 #endif /* SIFTR_IPV6 */ 107 108 #include <machine/in_cksum.h> 109 110 /* 111 * Three digit version number refers to X.Y.Z where: 112 * X is the major version number 113 * Y is bumped to mark backwards incompatible changes 114 * Z is bumped to mark backwards compatible changes 115 */ 116 #define V_MAJOR 1 117 #define V_BACKBREAK 3 118 #define V_BACKCOMPAT 0 119 #define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT)) 120 #define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \ 121 __XSTRING(V_BACKCOMPAT) 122 123 #define HOOK 0 124 #define UNHOOK 1 125 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536 126 #define SYS_NAME "FreeBSD" 127 #define PACKET_TAG_SIFTR 100 128 #define PACKET_COOKIE_SIFTR 21749576 129 #define SIFTR_LOG_FILE_MODE 0644 130 #define SIFTR_DISABLE 0 131 #define SIFTR_ENABLE 1 132 133 /* 134 * Hard upper limit on the length of log messages. Bump this up if you add new 135 * data fields such that the line length could exceed the below value. 136 */ 137 #define MAX_LOG_MSG_LEN 300 138 /* 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 146 147 static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR"); 148 static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode", 149 "SIFTR pkt_node struct"); 150 static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode", 151 "SIFTR flow_hash_node struct"); 152 153 /* Used as links in the pkt manager queue. */ 154 struct 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 }; 217 218 struct 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 }; 231 232 struct 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 }; 238 239 struct 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 }; 257 258 DPCPU_DEFINE_STATIC(struct siftr_stats, ss); 259 260 static volatile unsigned int siftr_exit_pkt_manager_thread = 0; 261 static unsigned int siftr_enabled = 0; 262 static unsigned int siftr_pkts_per_log = 1; 263 static uint16_t siftr_port_filter = 0; 264 /* static unsigned int siftr_binary_log = 0; */ 265 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log"; 266 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log"; 267 static u_long siftr_hashmask; 268 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue); 269 LIST_HEAD(listhead, flow_hash_node) *counter_hash; 270 static int wait_for_pkt; 271 static struct alq *siftr_alq = NULL; 272 static struct mtx siftr_pkt_queue_mtx; 273 static struct mtx siftr_pkt_mgr_mtx; 274 static struct thread *siftr_pkt_manager_thr = NULL; 275 static char direction[2] = {'i','o'}; 276 277 /* Required function prototypes. */ 278 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS); 279 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS); 280 281 /* Declare the net.inet.siftr sysctl tree and populate it. */ 282 283 SYSCTL_DECL(_net_inet_siftr); 284 285 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 286 "siftr related settings"); 287 288 SYSCTL_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"); 292 293 SYSCTL_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"); 297 298 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW, 299 &siftr_pkts_per_log, 1, 300 "number of packets between generating a log message"); 301 302 SYSCTL_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 307 SYSCTL_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. */ 313 314 static inline struct flow_hash_node * 315 siftr_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 } 344 345 static inline struct flow_hash_node * 346 siftr_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 } 373 374 static int 375 siftr_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 } 443 444 static void 445 siftr_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, *pkt_node_temp; 450 uint8_t draining; 451 struct ale *log_buf; 452 int ret_sz, cnt; 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 try_again: 490 pkt_node = STAILQ_FIRST(&tmp_pkt_queue); 491 if (pkt_node != NULL) { 492 if (STAILQ_NEXT(pkt_node, nodes) != NULL) { 493 cnt = 3; 494 } else { 495 cnt = 1; 496 } 497 498 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN * cnt, 499 ALQ_WAITOK); 500 501 if (log_buf != NULL) { 502 log_buf->ae_bytesused = 0; 503 bufp = log_buf->ae_data; 504 } else { 505 /* 506 * Should only happen if the ALQ is shutting 507 * down. 508 */ 509 bufp = NULL; 510 } 511 512 /* Flush all pkt_nodes to the log file. */ 513 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes, 514 pkt_node_temp) { 515 if (log_buf != NULL) { 516 ret_sz = siftr_process_pkt(pkt_node, 517 bufp); 518 bufp += ret_sz; 519 log_buf->ae_bytesused += ret_sz; 520 cnt--; 521 } 522 523 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes); 524 free(pkt_node, M_SIFTR_PKTNODE); 525 526 if (cnt <= 0 && !STAILQ_EMPTY(&tmp_pkt_queue)) { 527 alq_post_flags(siftr_alq, log_buf, 0); 528 goto try_again; 529 } 530 } 531 if (log_buf != NULL) { 532 alq_post_flags(siftr_alq, log_buf, 0); 533 } 534 } 535 536 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue), 537 ("SIFTR tmp_pkt_queue not empty after flush")); 538 539 mtx_lock(&siftr_pkt_mgr_mtx); 540 541 /* 542 * If siftr_exit_pkt_manager_thread gets set during the window 543 * where we are draining the tmp_pkt_queue above, there might 544 * still be pkts in pkt_queue that need to be drained. 545 * Allow one further iteration to occur after 546 * siftr_exit_pkt_manager_thread has been set to ensure 547 * pkt_queue is completely empty before we kill the thread. 548 * 549 * siftr_exit_pkt_manager_thread is set only after the pfil 550 * hooks have been removed, so only 1 extra iteration 551 * is needed to drain the queue. 552 */ 553 if (siftr_exit_pkt_manager_thread) 554 draining--; 555 } 556 557 mtx_unlock(&siftr_pkt_mgr_mtx); 558 559 /* Calls wakeup on this thread's struct thread ptr. */ 560 kthread_exit(); 561 } 562 563 /* 564 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that 565 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return. 566 * Return value >0 means the caller should skip processing this mbuf. 567 */ 568 static inline int 569 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss) 570 { 571 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL) 572 != NULL) { 573 if (dir == PFIL_IN) 574 ss->nskip_in_dejavu++; 575 else 576 ss->nskip_out_dejavu++; 577 578 return (1); 579 } else { 580 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR, 581 PACKET_TAG_SIFTR, 0, M_NOWAIT); 582 if (tag == NULL) { 583 if (dir == PFIL_IN) 584 ss->nskip_in_malloc++; 585 else 586 ss->nskip_out_malloc++; 587 588 return (1); 589 } 590 591 m_tag_prepend(m, tag); 592 } 593 594 return (0); 595 } 596 597 /* 598 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL 599 * otherwise. 600 */ 601 static inline struct inpcb * 602 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport, 603 uint16_t dport, int dir, struct siftr_stats *ss) 604 { 605 struct inpcb *inp; 606 607 /* We need the tcbinfo lock. */ 608 INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo); 609 610 if (dir == PFIL_IN) 611 inp = (ipver == INP_IPV4 ? 612 in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst, 613 dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 614 : 615 #ifdef SIFTR_IPV6 616 in6_pcblookup(&V_tcbinfo, 617 &((struct ip6_hdr *)ip)->ip6_src, sport, 618 &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB, 619 m->m_pkthdr.rcvif) 620 #else 621 NULL 622 #endif 623 ); 624 625 else 626 inp = (ipver == INP_IPV4 ? 627 in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src, 628 sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 629 : 630 #ifdef SIFTR_IPV6 631 in6_pcblookup(&V_tcbinfo, 632 &((struct ip6_hdr *)ip)->ip6_dst, dport, 633 &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB, 634 m->m_pkthdr.rcvif) 635 #else 636 NULL 637 #endif 638 ); 639 640 /* If we can't find the inpcb, bail. */ 641 if (inp == NULL) { 642 if (dir == PFIL_IN) 643 ss->nskip_in_inpcb++; 644 else 645 ss->nskip_out_inpcb++; 646 } 647 648 return (inp); 649 } 650 651 static inline uint32_t 652 siftr_get_flowid(struct inpcb *inp, int ipver, uint32_t *phashtype) 653 { 654 if (inp->inp_flowid == 0) { 655 #ifdef SIFTR_IPV6 656 if (ipver == INP_IPV6) { 657 return fib6_calc_packet_hash(&inp->in6p_laddr, 658 &inp->in6p_faddr, 659 inp->inp_lport, 660 inp->inp_fport, 661 IPPROTO_TCP, 662 phashtype); 663 } else 664 #endif 665 { 666 return fib4_calc_packet_hash(inp->inp_laddr, 667 inp->inp_faddr, 668 inp->inp_lport, 669 inp->inp_fport, 670 IPPROTO_TCP, 671 phashtype); 672 } 673 } else { 674 *phashtype = inp->inp_flowtype; 675 return inp->inp_flowid; 676 } 677 } 678 679 static inline void 680 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp, 681 int ipver, int dir, int inp_locally_locked) 682 { 683 pn->ipver = ipver; 684 pn->lport = inp->inp_lport; 685 pn->fport = inp->inp_fport; 686 pn->laddr = inp->inp_inc.inc_ie.ie_dependladdr; 687 pn->faddr = inp->inp_inc.inc_ie.ie_dependfaddr; 688 pn->snd_cwnd = tp->snd_cwnd; 689 pn->snd_wnd = tp->snd_wnd; 690 pn->rcv_wnd = tp->rcv_wnd; 691 pn->t_flags2 = tp->t_flags2; 692 pn->snd_ssthresh = tp->snd_ssthresh; 693 pn->snd_scale = tp->snd_scale; 694 pn->rcv_scale = tp->rcv_scale; 695 pn->conn_state = tp->t_state; 696 pn->mss = tp->t_maxseg; 697 pn->srtt = ((uint64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT; 698 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0; 699 pn->t_flags = tp->t_flags; 700 pn->rto = tp->t_rxtcur * tick; 701 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat; 702 pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd); 703 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat; 704 pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv); 705 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una; 706 pn->t_segqlen = tp->t_segqlen; 707 708 /* We've finished accessing the tcb so release the lock. */ 709 if (inp_locally_locked) 710 INP_RUNLOCK(inp); 711 712 pn->direction = (dir == PFIL_IN ? DIR_IN : DIR_OUT); 713 714 /* 715 * Significantly more accurate than using getmicrotime(), but slower! 716 * Gives true microsecond resolution at the expense of a hit to 717 * maximum pps throughput processing when SIFTR is loaded and enabled. 718 */ 719 microtime(&pn->tval); 720 TCP_PROBE1(siftr, pn); 721 } 722 723 /* 724 * pfil hook that is called for each IPv4 packet making its way through the 725 * stack in either direction. 726 * The pfil subsystem holds a non-sleepable mutex somewhere when 727 * calling our hook function, so we can't sleep at all. 728 * It's very important to use the M_NOWAIT flag with all function calls 729 * that support it so that they won't sleep, otherwise you get a panic. 730 */ 731 static pfil_return_t 732 siftr_chkpkt(struct mbuf **m, struct ifnet *ifp, int flags, 733 void *ruleset __unused, struct inpcb *inp) 734 { 735 struct pkt_node *pn; 736 struct ip *ip; 737 struct tcphdr *th; 738 struct tcpcb *tp; 739 struct siftr_stats *ss; 740 unsigned int ip_hl; 741 int inp_locally_locked, dir; 742 uint32_t hash_id, hash_type; 743 struct listhead *counter_list; 744 struct flow_hash_node *hash_node; 745 746 inp_locally_locked = 0; 747 dir = PFIL_DIR(flags); 748 ss = DPCPU_PTR(ss); 749 750 /* 751 * m_pullup is not required here because ip_{input|output} 752 * already do the heavy lifting for us. 753 */ 754 755 ip = mtod(*m, struct ip *); 756 757 /* Only continue processing if the packet is TCP. */ 758 if (ip->ip_p != IPPROTO_TCP) 759 goto ret; 760 761 /* 762 * Create a tcphdr struct starting at the correct offset 763 * in the IP packet. ip->ip_hl gives the ip header length 764 * in 4-byte words, so multiply it to get the size in bytes. 765 */ 766 ip_hl = (ip->ip_hl << 2); 767 th = (struct tcphdr *)((caddr_t)ip + ip_hl); 768 769 /* 770 * Only pkts selected by the tcp port filter 771 * can be inserted into the pkt_queue 772 */ 773 if ((siftr_port_filter != 0) && 774 (siftr_port_filter != ntohs(th->th_sport)) && 775 (siftr_port_filter != ntohs(th->th_dport))) { 776 goto ret; 777 } 778 779 /* 780 * If a kernel subsystem reinjects packets into the stack, our pfil 781 * hook will be called multiple times for the same packet. 782 * Make sure we only process unique packets. 783 */ 784 if (siftr_chkreinject(*m, dir, ss)) 785 goto ret; 786 787 if (dir == PFIL_IN) 788 ss->n_in++; 789 else 790 ss->n_out++; 791 792 /* 793 * If the pfil hooks don't provide a pointer to the 794 * inpcb, we need to find it ourselves and lock it. 795 */ 796 if (!inp) { 797 /* Find the corresponding inpcb for this pkt. */ 798 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport, 799 th->th_dport, dir, ss); 800 801 if (inp == NULL) 802 goto ret; 803 else 804 inp_locally_locked = 1; 805 } 806 807 INP_LOCK_ASSERT(inp); 808 809 /* Find the TCP control block that corresponds with this packet */ 810 tp = intotcpcb(inp); 811 812 /* 813 * If we can't find the TCP control block (happens occasionaly for a 814 * packet sent during the shutdown phase of a TCP connection), or the 815 * TCP control block has not initialized (happens during TCPS_SYN_SENT), 816 * bail. 817 */ 818 if (tp == NULL || tp->t_state < TCPS_ESTABLISHED) { 819 if (dir == PFIL_IN) 820 ss->nskip_in_tcpcb++; 821 else 822 ss->nskip_out_tcpcb++; 823 824 goto inp_unlock; 825 } 826 827 hash_id = siftr_get_flowid(inp, INP_IPV4, &hash_type); 828 counter_list = counter_hash + (hash_id & siftr_hashmask); 829 hash_node = siftr_find_flow(counter_list, hash_id); 830 831 /* If this flow hasn't been seen before, we create a new entry. */ 832 if (hash_node == NULL) { 833 struct flow_info info; 834 835 inet_ntoa_r(inp->inp_laddr, info.laddr); 836 inet_ntoa_r(inp->inp_faddr, info.faddr); 837 info.lport = ntohs(inp->inp_lport); 838 info.fport = ntohs(inp->inp_fport); 839 info.key = hash_id; 840 841 hash_node = siftr_new_hash_node(info, dir, ss); 842 } 843 844 if (hash_node == NULL) { 845 goto inp_unlock; 846 } 847 848 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 849 850 if (pn == NULL) { 851 if (dir == PFIL_IN) 852 ss->nskip_in_malloc++; 853 else 854 ss->nskip_out_malloc++; 855 856 goto inp_unlock; 857 } 858 859 pn->flowid = hash_id; 860 pn->flowtype = hash_type; 861 862 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked); 863 864 mtx_lock(&siftr_pkt_queue_mtx); 865 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 866 mtx_unlock(&siftr_pkt_queue_mtx); 867 goto ret; 868 869 inp_unlock: 870 if (inp_locally_locked) 871 INP_RUNLOCK(inp); 872 873 ret: 874 return (PFIL_PASS); 875 } 876 877 #ifdef SIFTR_IPV6 878 static pfil_return_t 879 siftr_chkpkt6(struct mbuf **m, struct ifnet *ifp, int flags, 880 void *ruleset __unused, struct inpcb *inp) 881 { 882 struct pkt_node *pn; 883 struct ip6_hdr *ip6; 884 struct tcphdr *th; 885 struct tcpcb *tp; 886 struct siftr_stats *ss; 887 unsigned int ip6_hl; 888 int inp_locally_locked, dir; 889 uint32_t hash_id, hash_type; 890 struct listhead *counter_list; 891 struct flow_hash_node *hash_node; 892 893 inp_locally_locked = 0; 894 dir = PFIL_DIR(flags); 895 ss = DPCPU_PTR(ss); 896 897 /* 898 * m_pullup is not required here because ip6_{input|output} 899 * already do the heavy lifting for us. 900 */ 901 902 ip6 = mtod(*m, struct ip6_hdr *); 903 904 /* 905 * Only continue processing if the packet is TCP 906 * XXX: We should follow the next header fields 907 * as shown on Pg 6 RFC 2460, but right now we'll 908 * only check pkts that have no extension headers. 909 */ 910 if (ip6->ip6_nxt != IPPROTO_TCP) 911 goto ret6; 912 913 /* 914 * Create a tcphdr struct starting at the correct offset 915 * in the ipv6 packet. 916 */ 917 ip6_hl = sizeof(struct ip6_hdr); 918 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl); 919 920 /* 921 * Only pkts selected by the tcp port filter 922 * can be inserted into the pkt_queue 923 */ 924 if ((siftr_port_filter != 0) && 925 (siftr_port_filter != ntohs(th->th_sport)) && 926 (siftr_port_filter != ntohs(th->th_dport))) { 927 goto ret6; 928 } 929 930 /* 931 * If a kernel subsystem reinjects packets into the stack, our pfil 932 * hook will be called multiple times for the same packet. 933 * Make sure we only process unique packets. 934 */ 935 if (siftr_chkreinject(*m, dir, ss)) 936 goto ret6; 937 938 if (dir == PFIL_IN) 939 ss->n_in++; 940 else 941 ss->n_out++; 942 943 /* 944 * For inbound packets, the pfil hooks don't provide a pointer to the 945 * inpcb, so we need to find it ourselves and lock it. 946 */ 947 if (!inp) { 948 /* Find the corresponding inpcb for this pkt. */ 949 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m, 950 th->th_sport, th->th_dport, dir, ss); 951 952 if (inp == NULL) 953 goto ret6; 954 else 955 inp_locally_locked = 1; 956 } 957 958 /* Find the TCP control block that corresponds with this packet. */ 959 tp = intotcpcb(inp); 960 961 /* 962 * If we can't find the TCP control block (happens occasionaly for a 963 * packet sent during the shutdown phase of a TCP connection), or the 964 * TCP control block has not initialized (happens during TCPS_SYN_SENT), 965 * bail. 966 */ 967 if (tp == NULL || tp->t_state < TCPS_ESTABLISHED) { 968 if (dir == PFIL_IN) 969 ss->nskip_in_tcpcb++; 970 else 971 ss->nskip_out_tcpcb++; 972 973 goto inp_unlock6; 974 } 975 976 hash_id = siftr_get_flowid(inp, INP_IPV6, &hash_type); 977 counter_list = counter_hash + (hash_id & siftr_hashmask); 978 hash_node = siftr_find_flow(counter_list, hash_id); 979 980 /* If this flow hasn't been seen before, we create a new entry. */ 981 if (!hash_node) { 982 struct flow_info info; 983 984 ip6_sprintf(info.laddr, &inp->in6p_laddr); 985 ip6_sprintf(info.faddr, &inp->in6p_faddr); 986 info.lport = ntohs(inp->inp_lport); 987 info.fport = ntohs(inp->inp_fport); 988 info.key = hash_id; 989 990 hash_node = siftr_new_hash_node(info, dir, ss); 991 } 992 993 if (!hash_node) { 994 goto inp_unlock6; 995 } 996 997 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 998 999 if (pn == NULL) { 1000 if (dir == PFIL_IN) 1001 ss->nskip_in_malloc++; 1002 else 1003 ss->nskip_out_malloc++; 1004 1005 goto inp_unlock6; 1006 } 1007 1008 pn->flowid = hash_id; 1009 pn->flowtype = hash_type; 1010 1011 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked); 1012 1013 mtx_lock(&siftr_pkt_queue_mtx); 1014 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 1015 mtx_unlock(&siftr_pkt_queue_mtx); 1016 goto ret6; 1017 1018 inp_unlock6: 1019 if (inp_locally_locked) 1020 INP_RUNLOCK(inp); 1021 1022 ret6: 1023 return (PFIL_PASS); 1024 } 1025 #endif /* #ifdef SIFTR_IPV6 */ 1026 1027 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet_hook); 1028 #define V_siftr_inet_hook VNET(siftr_inet_hook) 1029 #ifdef SIFTR_IPV6 1030 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet6_hook); 1031 #define V_siftr_inet6_hook VNET(siftr_inet6_hook) 1032 #endif 1033 static int 1034 siftr_pfil(int action) 1035 { 1036 struct pfil_hook_args pha = { 1037 .pa_version = PFIL_VERSION, 1038 .pa_flags = PFIL_IN | PFIL_OUT, 1039 .pa_modname = "siftr", 1040 .pa_rulname = "default", 1041 }; 1042 struct pfil_link_args pla = { 1043 .pa_version = PFIL_VERSION, 1044 .pa_flags = PFIL_IN | PFIL_OUT | PFIL_HEADPTR | PFIL_HOOKPTR, 1045 }; 1046 1047 VNET_ITERATOR_DECL(vnet_iter); 1048 1049 VNET_LIST_RLOCK(); 1050 VNET_FOREACH(vnet_iter) { 1051 CURVNET_SET(vnet_iter); 1052 1053 if (action == HOOK) { 1054 pha.pa_mbuf_chk = siftr_chkpkt; 1055 pha.pa_type = PFIL_TYPE_IP4; 1056 V_siftr_inet_hook = pfil_add_hook(&pha); 1057 pla.pa_hook = V_siftr_inet_hook; 1058 pla.pa_head = V_inet_pfil_head; 1059 (void)pfil_link(&pla); 1060 #ifdef SIFTR_IPV6 1061 pha.pa_mbuf_chk = siftr_chkpkt6; 1062 pha.pa_type = PFIL_TYPE_IP6; 1063 V_siftr_inet6_hook = pfil_add_hook(&pha); 1064 pla.pa_hook = V_siftr_inet6_hook; 1065 pla.pa_head = V_inet6_pfil_head; 1066 (void)pfil_link(&pla); 1067 #endif 1068 } else if (action == UNHOOK) { 1069 pfil_remove_hook(V_siftr_inet_hook); 1070 #ifdef SIFTR_IPV6 1071 pfil_remove_hook(V_siftr_inet6_hook); 1072 #endif 1073 } 1074 CURVNET_RESTORE(); 1075 } 1076 VNET_LIST_RUNLOCK(); 1077 1078 return (0); 1079 } 1080 1081 static int 1082 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS) 1083 { 1084 struct alq *new_alq; 1085 int error; 1086 1087 error = sysctl_handle_string(oidp, arg1, arg2, req); 1088 1089 /* Check for error or same filename */ 1090 if (error != 0 || req->newptr == NULL || 1091 strncmp(siftr_logfile, arg1, arg2) == 0) 1092 goto done; 1093 1094 /* file name changed */ 1095 error = alq_open(&new_alq, arg1, curthread->td_ucred, 1096 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1097 if (error != 0) 1098 goto done; 1099 1100 /* 1101 * If disabled, siftr_alq == NULL so we simply close 1102 * the alq as we've proved it can be opened. 1103 * If enabled, close the existing alq and switch the old 1104 * for the new. 1105 */ 1106 if (siftr_alq == NULL) { 1107 alq_close(new_alq); 1108 } else { 1109 alq_close(siftr_alq); 1110 siftr_alq = new_alq; 1111 } 1112 1113 /* Update filename upon success */ 1114 strlcpy(siftr_logfile, arg1, arg2); 1115 done: 1116 return (error); 1117 } 1118 1119 static int 1120 siftr_manage_ops(uint8_t action) 1121 { 1122 struct siftr_stats totalss; 1123 struct timeval tval; 1124 struct flow_hash_node *counter, *tmp_counter; 1125 struct sbuf *s; 1126 int i, error; 1127 uint32_t bytes_to_write, total_skipped_pkts; 1128 1129 error = 0; 1130 total_skipped_pkts = 0; 1131 1132 /* Init an autosizing sbuf that initially holds 200 chars. */ 1133 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL) 1134 return (-1); 1135 1136 if (action == SIFTR_ENABLE && siftr_pkt_manager_thr == NULL) { 1137 /* 1138 * Create our alq 1139 * XXX: We should abort if alq_open fails! 1140 */ 1141 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred, 1142 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1143 1144 STAILQ_INIT(&pkt_queue); 1145 1146 DPCPU_ZERO(ss); 1147 1148 siftr_exit_pkt_manager_thread = 0; 1149 1150 kthread_add(&siftr_pkt_manager_thread, NULL, NULL, 1151 &siftr_pkt_manager_thr, RFNOWAIT, 0, 1152 "siftr_pkt_manager_thr"); 1153 1154 siftr_pfil(HOOK); 1155 1156 microtime(&tval); 1157 1158 sbuf_printf(s, 1159 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t" 1160 "siftrver=%s\tsysname=%s\tsysver=%u\tipmode=%u\n", 1161 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, 1162 SYS_NAME, __FreeBSD_version, SIFTR_IPMODE); 1163 1164 sbuf_finish(s); 1165 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK); 1166 1167 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) { 1168 /* 1169 * Remove the pfil hook functions. All threads currently in 1170 * the hook functions are allowed to exit before siftr_pfil() 1171 * returns. 1172 */ 1173 siftr_pfil(UNHOOK); 1174 1175 /* This will block until the pkt manager thread unlocks it. */ 1176 mtx_lock(&siftr_pkt_mgr_mtx); 1177 1178 /* Tell the pkt manager thread that it should exit now. */ 1179 siftr_exit_pkt_manager_thread = 1; 1180 1181 /* 1182 * Wake the pkt_manager thread so it realises that 1183 * siftr_exit_pkt_manager_thread == 1 and exits gracefully. 1184 * The wakeup won't be delivered until we unlock 1185 * siftr_pkt_mgr_mtx so this isn't racy. 1186 */ 1187 wakeup(&wait_for_pkt); 1188 1189 /* Wait for the pkt_manager thread to exit. */ 1190 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT, 1191 "thrwait", 0); 1192 1193 siftr_pkt_manager_thr = NULL; 1194 mtx_unlock(&siftr_pkt_mgr_mtx); 1195 1196 totalss.n_in = DPCPU_VARSUM(ss, n_in); 1197 totalss.n_out = DPCPU_VARSUM(ss, n_out); 1198 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc); 1199 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc); 1200 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb); 1201 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb); 1202 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb); 1203 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb); 1204 1205 total_skipped_pkts = totalss.nskip_in_malloc + 1206 totalss.nskip_out_malloc + totalss.nskip_in_tcpcb + 1207 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb + 1208 totalss.nskip_out_inpcb; 1209 1210 microtime(&tval); 1211 1212 sbuf_printf(s, 1213 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t" 1214 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t" 1215 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t" 1216 "num_outbound_skipped_pkts_malloc=%u\t" 1217 "num_inbound_skipped_pkts_tcpcb=%u\t" 1218 "num_outbound_skipped_pkts_tcpcb=%u\t" 1219 "num_inbound_skipped_pkts_inpcb=%u\t" 1220 "num_outbound_skipped_pkts_inpcb=%u\t" 1221 "total_skipped_tcp_pkts=%u\tflow_list=", 1222 (intmax_t)tval.tv_sec, 1223 tval.tv_usec, 1224 (uintmax_t)totalss.n_in, 1225 (uintmax_t)totalss.n_out, 1226 (uintmax_t)(totalss.n_in + totalss.n_out), 1227 totalss.nskip_in_malloc, 1228 totalss.nskip_out_malloc, 1229 totalss.nskip_in_tcpcb, 1230 totalss.nskip_out_tcpcb, 1231 totalss.nskip_in_inpcb, 1232 totalss.nskip_out_inpcb, 1233 total_skipped_pkts); 1234 1235 /* 1236 * Iterate over the flow hash, printing a summary of each 1237 * flow seen and freeing any malloc'd memory. 1238 * The hash consists of an array of LISTs (man 3 queue). 1239 */ 1240 for (i = 0; i <= siftr_hashmask; i++) { 1241 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes, 1242 tmp_counter) { 1243 sbuf_printf(s, "%s;%hu-%s;%hu,", 1244 counter->const_info.laddr, 1245 counter->const_info.lport, 1246 counter->const_info.faddr, 1247 counter->const_info.fport); 1248 1249 free(counter, M_SIFTR_HASHNODE); 1250 } 1251 1252 LIST_INIT(counter_hash + i); 1253 } 1254 1255 sbuf_printf(s, "\n"); 1256 sbuf_finish(s); 1257 1258 i = 0; 1259 do { 1260 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i); 1261 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK); 1262 i += bytes_to_write; 1263 } while (i < sbuf_len(s)); 1264 1265 alq_close(siftr_alq); 1266 siftr_alq = NULL; 1267 } else 1268 error = EINVAL; 1269 1270 sbuf_delete(s); 1271 1272 /* 1273 * XXX: Should be using ret to check if any functions fail 1274 * and set error appropriately 1275 */ 1276 1277 return (error); 1278 } 1279 1280 static int 1281 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS) 1282 { 1283 int error; 1284 uint32_t new; 1285 1286 new = siftr_enabled; 1287 error = sysctl_handle_int(oidp, &new, 0, req); 1288 if (error == 0 && req->newptr != NULL) { 1289 if (new > 1) 1290 return (EINVAL); 1291 else if (new != siftr_enabled) { 1292 if ((error = siftr_manage_ops(new)) == 0) { 1293 siftr_enabled = new; 1294 } else { 1295 siftr_manage_ops(SIFTR_DISABLE); 1296 } 1297 } 1298 } 1299 1300 return (error); 1301 } 1302 1303 static void 1304 siftr_shutdown_handler(void *arg, int howto) 1305 { 1306 if ((howto & RB_NOSYNC) != 0 || SCHEDULER_STOPPED()) 1307 return; 1308 1309 if (siftr_enabled == 1) { 1310 siftr_manage_ops(SIFTR_DISABLE); 1311 } 1312 } 1313 1314 /* 1315 * Module is being unloaded or machine is shutting down. Take care of cleanup. 1316 */ 1317 static int 1318 deinit_siftr(void) 1319 { 1320 /* Cleanup. */ 1321 siftr_manage_ops(SIFTR_DISABLE); 1322 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask); 1323 mtx_destroy(&siftr_pkt_queue_mtx); 1324 mtx_destroy(&siftr_pkt_mgr_mtx); 1325 1326 return (0); 1327 } 1328 1329 /* 1330 * Module has just been loaded into the kernel. 1331 */ 1332 static int 1333 init_siftr(void) 1334 { 1335 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL, 1336 SHUTDOWN_PRI_FIRST); 1337 1338 /* Initialise our flow counter hash table. */ 1339 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR, 1340 &siftr_hashmask); 1341 1342 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF); 1343 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF); 1344 1345 /* Print message to the user's current terminal. */ 1346 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n" 1347 " http://caia.swin.edu.au/urp/newtcp\n\n", 1348 MODVERSION_STR); 1349 1350 return (0); 1351 } 1352 1353 /* 1354 * This is the function that is called to load and unload the module. 1355 * When the module is loaded, this function is called once with 1356 * "what" == MOD_LOAD 1357 * When the module is unloaded, this function is called twice with 1358 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second 1359 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command, 1360 * this function is called once with "what" = MOD_SHUTDOWN 1361 * When the system is shut down, the handler isn't called until the very end 1362 * of the shutdown sequence i.e. after the disks have been synced. 1363 */ 1364 static int 1365 siftr_load_handler(module_t mod, int what, void *arg) 1366 { 1367 int ret; 1368 1369 switch (what) { 1370 case MOD_LOAD: 1371 ret = init_siftr(); 1372 break; 1373 1374 case MOD_QUIESCE: 1375 case MOD_SHUTDOWN: 1376 ret = deinit_siftr(); 1377 break; 1378 1379 case MOD_UNLOAD: 1380 ret = 0; 1381 break; 1382 1383 default: 1384 ret = EINVAL; 1385 break; 1386 } 1387 1388 return (ret); 1389 } 1390 1391 static moduledata_t siftr_mod = { 1392 .name = "siftr", 1393 .evhand = siftr_load_handler, 1394 }; 1395 1396 /* 1397 * Param 1: name of the kernel module 1398 * Param 2: moduledata_t struct containing info about the kernel module 1399 * and the execution entry point for the module 1400 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h 1401 * Defines the module initialisation order 1402 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h 1403 * Defines the initialisation order of this kld relative to others 1404 * within the same subsystem as defined by param 3 1405 */ 1406 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY); 1407 MODULE_DEPEND(siftr, alq, 1, 1, 1); 1408 MODULE_VERSION(siftr, MODVERSION); 1409