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 /* XXX: Make this a sysctl tunable. */ 138 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN) 139 140 #ifdef SIFTR_IPV6 141 #define SIFTR_IPMODE 6 142 #else 143 #define SIFTR_IPMODE 4 144 #endif 145 146 static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR"); 147 static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode", 148 "SIFTR pkt_node struct"); 149 static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode", 150 "SIFTR flow_hash_node struct"); 151 152 /* Used as links in the pkt manager queue. */ 153 struct pkt_node { 154 /* Timestamp of pkt as noted in the pfil hook. */ 155 struct timeval tval; 156 /* Direction pkt is travelling. */ 157 enum { 158 DIR_IN = 0, 159 DIR_OUT = 1, 160 } direction; 161 /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */ 162 uint8_t ipver; 163 /* Local TCP port. */ 164 uint16_t lport; 165 /* Foreign TCP port. */ 166 uint16_t fport; 167 /* Local address. */ 168 union in_dependaddr laddr; 169 /* Foreign address. */ 170 union in_dependaddr faddr; 171 /* Congestion Window (bytes). */ 172 uint32_t snd_cwnd; 173 /* Sending Window (bytes). */ 174 uint32_t snd_wnd; 175 /* Receive Window (bytes). */ 176 uint32_t rcv_wnd; 177 /* More tcpcb flags storage */ 178 uint32_t t_flags2; 179 /* Slow Start Threshold (bytes). */ 180 uint32_t snd_ssthresh; 181 /* Current state of the TCP FSM. */ 182 int conn_state; 183 /* Max Segment Size (bytes). */ 184 uint32_t mss; 185 /* Smoothed RTT (usecs). */ 186 uint32_t srtt; 187 /* Is SACK enabled? */ 188 u_char sack_enabled; 189 /* Window scaling for snd window. */ 190 u_char snd_scale; 191 /* Window scaling for recv window. */ 192 u_char rcv_scale; 193 /* TCP control block flags. */ 194 u_int t_flags; 195 /* Retransmission timeout (usec). */ 196 uint32_t rto; 197 /* Size of the TCP send buffer in bytes. */ 198 u_int snd_buf_hiwater; 199 /* Current num bytes in the send socket buffer. */ 200 u_int snd_buf_cc; 201 /* Size of the TCP receive buffer in bytes. */ 202 u_int rcv_buf_hiwater; 203 /* Current num bytes in the receive socket buffer. */ 204 u_int rcv_buf_cc; 205 /* Number of bytes inflight that we are waiting on ACKs for. */ 206 u_int sent_inflight_bytes; 207 /* Number of segments currently in the reassembly queue. */ 208 int t_segqlen; 209 /* Flowid for the connection. */ 210 u_int flowid; 211 /* Flow type for the connection. */ 212 u_int flowtype; 213 /* Link to next pkt_node in the list. */ 214 STAILQ_ENTRY(pkt_node) nodes; 215 }; 216 217 struct flow_info 218 { 219 #ifdef SIFTR_IPV6 220 char laddr[INET6_ADDRSTRLEN]; /* local IP address */ 221 char faddr[INET6_ADDRSTRLEN]; /* foreign IP address */ 222 #else 223 char laddr[INET_ADDRSTRLEN]; /* local IP address */ 224 char faddr[INET_ADDRSTRLEN]; /* foreign IP address */ 225 #endif 226 uint16_t lport; /* local TCP port */ 227 uint16_t fport; /* foreign TCP port */ 228 uint32_t key; /* flowid of the connection */ 229 }; 230 231 struct flow_hash_node 232 { 233 uint16_t counter; 234 struct flow_info const_info; /* constant connection info */ 235 LIST_ENTRY(flow_hash_node) nodes; 236 }; 237 238 struct siftr_stats 239 { 240 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */ 241 uint64_t n_in; 242 uint64_t n_out; 243 /* # pkts skipped due to failed malloc calls. */ 244 uint32_t nskip_in_malloc; 245 uint32_t nskip_out_malloc; 246 /* # pkts skipped due to failed inpcb lookups. */ 247 uint32_t nskip_in_inpcb; 248 uint32_t nskip_out_inpcb; 249 /* # pkts skipped due to failed tcpcb lookups. */ 250 uint32_t nskip_in_tcpcb; 251 uint32_t nskip_out_tcpcb; 252 /* # pkts skipped due to stack reinjection. */ 253 uint32_t nskip_in_dejavu; 254 uint32_t nskip_out_dejavu; 255 }; 256 257 DPCPU_DEFINE_STATIC(struct siftr_stats, ss); 258 259 static volatile unsigned int siftr_exit_pkt_manager_thread = 0; 260 static unsigned int siftr_enabled = 0; 261 static unsigned int siftr_pkts_per_log = 1; 262 static uint16_t siftr_port_filter = 0; 263 /* static unsigned int siftr_binary_log = 0; */ 264 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log"; 265 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log"; 266 static u_long siftr_hashmask; 267 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue); 268 LIST_HEAD(listhead, flow_hash_node) *counter_hash; 269 static int wait_for_pkt; 270 static struct alq *siftr_alq = NULL; 271 static struct mtx siftr_pkt_queue_mtx; 272 static struct mtx siftr_pkt_mgr_mtx; 273 static struct thread *siftr_pkt_manager_thr = NULL; 274 static char direction[2] = {'i','o'}; 275 276 /* Required function prototypes. */ 277 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS); 278 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS); 279 280 /* Declare the net.inet.siftr sysctl tree and populate it. */ 281 282 SYSCTL_DECL(_net_inet_siftr); 283 284 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 285 "siftr related settings"); 286 287 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, 288 CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 289 &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU", 290 "switch siftr module operations on/off"); 291 292 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, 293 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &siftr_logfile_shadow, 294 sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler, "A", 295 "file to save siftr log messages to"); 296 297 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW, 298 &siftr_pkts_per_log, 1, 299 "number of packets between generating a log message"); 300 301 SYSCTL_U16(_net_inet_siftr, OID_AUTO, port_filter, CTLFLAG_RW, 302 &siftr_port_filter, 0, 303 "enable packet filter on a TCP port"); 304 305 /* XXX: TODO 306 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW, 307 &siftr_binary_log, 0, 308 "write log files in binary instead of ascii"); 309 */ 310 311 /* Begin functions. */ 312 313 static inline struct flow_hash_node * 314 siftr_find_flow(struct listhead *counter_list, uint32_t id) 315 { 316 struct flow_hash_node *hash_node; 317 /* 318 * If the list is not empty i.e. the hash index has 319 * been used by another flow previously. 320 */ 321 if (LIST_FIRST(counter_list) != NULL) { 322 /* 323 * Loop through the hash nodes in the list. 324 * There should normally only be 1 hash node in the list. 325 */ 326 LIST_FOREACH(hash_node, counter_list, nodes) { 327 /* 328 * Check if the key for the pkt we are currently 329 * processing is the same as the key stored in the 330 * hash node we are currently processing. 331 * If they are the same, then we've found the 332 * hash node that stores the counter for the flow 333 * the pkt belongs to. 334 */ 335 if (hash_node->const_info.key == id) { 336 return hash_node; 337 } 338 } 339 } 340 341 return NULL; 342 } 343 344 static inline struct flow_hash_node * 345 siftr_new_hash_node(struct flow_info info, int dir, 346 struct siftr_stats *ss) 347 { 348 struct flow_hash_node *hash_node; 349 struct listhead *counter_list; 350 351 counter_list = counter_hash + (info.key & siftr_hashmask); 352 /* Create a new hash node to store the flow's constant info. */ 353 hash_node = malloc(sizeof(struct flow_hash_node), M_SIFTR_HASHNODE, 354 M_NOWAIT|M_ZERO); 355 356 if (hash_node != NULL) { 357 /* Initialise our new hash node list entry. */ 358 hash_node->counter = 0; 359 hash_node->const_info = info; 360 LIST_INSERT_HEAD(counter_list, hash_node, nodes); 361 return hash_node; 362 } else { 363 /* malloc failed */ 364 if (dir == DIR_IN) 365 ss->nskip_in_malloc++; 366 else 367 ss->nskip_out_malloc++; 368 369 return NULL; 370 } 371 } 372 373 static int 374 siftr_process_pkt(struct pkt_node * pkt_node, char *buf) 375 { 376 struct flow_hash_node *hash_node; 377 struct listhead *counter_list; 378 int ret_sz; 379 380 if (pkt_node->flowid == 0) { 381 panic("%s: flowid not available", __func__); 382 } 383 384 counter_list = counter_hash + (pkt_node->flowid & siftr_hashmask); 385 hash_node = siftr_find_flow(counter_list, pkt_node->flowid); 386 387 if (hash_node == NULL) { 388 return 0; 389 } else if (siftr_pkts_per_log > 1) { 390 /* 391 * Taking the remainder of the counter divided 392 * by the current value of siftr_pkts_per_log 393 * and storing that in counter provides a neat 394 * way to modulate the frequency of log 395 * messages being written to the log file. 396 */ 397 hash_node->counter = (hash_node->counter + 1) % 398 siftr_pkts_per_log; 399 /* 400 * If we have not seen enough packets since the last time 401 * we wrote a log message for this connection, return. 402 */ 403 if (hash_node->counter > 0) 404 return 0; 405 } 406 407 /* Construct a log message. */ 408 ret_sz = snprintf(buf, MAX_LOG_MSG_LEN, 409 "%c,%jd.%06ld,%s,%hu,%s,%hu,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u," 410 "%u,%u,%u,%u,%u,%u,%u,%u\n", 411 direction[pkt_node->direction], 412 (intmax_t)pkt_node->tval.tv_sec, 413 pkt_node->tval.tv_usec, 414 hash_node->const_info.laddr, 415 hash_node->const_info.lport, 416 hash_node->const_info.faddr, 417 hash_node->const_info.fport, 418 pkt_node->snd_ssthresh, 419 pkt_node->snd_cwnd, 420 pkt_node->t_flags2, 421 pkt_node->snd_wnd, 422 pkt_node->rcv_wnd, 423 pkt_node->snd_scale, 424 pkt_node->rcv_scale, 425 pkt_node->conn_state, 426 pkt_node->mss, 427 pkt_node->srtt, 428 pkt_node->sack_enabled, 429 pkt_node->t_flags, 430 pkt_node->rto, 431 pkt_node->snd_buf_hiwater, 432 pkt_node->snd_buf_cc, 433 pkt_node->rcv_buf_hiwater, 434 pkt_node->rcv_buf_cc, 435 pkt_node->sent_inflight_bytes, 436 pkt_node->t_segqlen, 437 pkt_node->flowid, 438 pkt_node->flowtype); 439 440 return ret_sz; 441 } 442 443 static void 444 siftr_pkt_manager_thread(void *arg) 445 { 446 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue = 447 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue); 448 struct pkt_node *pkt_node, *pkt_node_temp; 449 uint8_t draining; 450 struct ale *log_buf; 451 int ret_sz, cnt; 452 char *bufp; 453 454 draining = 2; 455 456 mtx_lock(&siftr_pkt_mgr_mtx); 457 458 /* draining == 0 when queue has been flushed and it's safe to exit. */ 459 while (draining) { 460 /* 461 * Sleep until we are signalled to wake because thread has 462 * been told to exit or until 1 tick has passed. 463 */ 464 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait", 465 1); 466 467 /* Gain exclusive access to the pkt_node queue. */ 468 mtx_lock(&siftr_pkt_queue_mtx); 469 470 /* 471 * Move pkt_queue to tmp_pkt_queue, which leaves 472 * pkt_queue empty and ready to receive more pkt_nodes. 473 */ 474 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue); 475 476 /* 477 * We've finished making changes to the list. Unlock it 478 * so the pfil hooks can continue queuing pkt_nodes. 479 */ 480 mtx_unlock(&siftr_pkt_queue_mtx); 481 482 /* 483 * We can't hold a mutex whilst calling siftr_process_pkt 484 * because ALQ might sleep waiting for buffer space. 485 */ 486 mtx_unlock(&siftr_pkt_mgr_mtx); 487 488 try_again: 489 pkt_node = STAILQ_FIRST(&tmp_pkt_queue); 490 if (pkt_node != NULL) { 491 if (STAILQ_NEXT(pkt_node, nodes) != NULL) { 492 cnt = 3; 493 } else { 494 cnt = 1; 495 } 496 497 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN * cnt, 498 ALQ_WAITOK); 499 500 if (log_buf != NULL) { 501 log_buf->ae_bytesused = 0; 502 bufp = log_buf->ae_data; 503 } else { 504 /* 505 * Should only happen if the ALQ is shutting 506 * down. 507 */ 508 bufp = NULL; 509 } 510 511 /* Flush all pkt_nodes to the log file. */ 512 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes, 513 pkt_node_temp) { 514 if (log_buf != NULL) { 515 ret_sz = siftr_process_pkt(pkt_node, 516 bufp); 517 bufp += ret_sz; 518 log_buf->ae_bytesused += ret_sz; 519 cnt--; 520 } 521 522 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes); 523 free(pkt_node, M_SIFTR_PKTNODE); 524 525 if (cnt <= 0 && !STAILQ_EMPTY(&tmp_pkt_queue)) { 526 alq_post_flags(siftr_alq, log_buf, 0); 527 goto try_again; 528 } 529 } 530 if (log_buf != NULL) { 531 alq_post_flags(siftr_alq, log_buf, 0); 532 } 533 } 534 535 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue), 536 ("SIFTR tmp_pkt_queue not empty after flush")); 537 538 mtx_lock(&siftr_pkt_mgr_mtx); 539 540 /* 541 * If siftr_exit_pkt_manager_thread gets set during the window 542 * where we are draining the tmp_pkt_queue above, there might 543 * still be pkts in pkt_queue that need to be drained. 544 * Allow one further iteration to occur after 545 * siftr_exit_pkt_manager_thread has been set to ensure 546 * pkt_queue is completely empty before we kill the thread. 547 * 548 * siftr_exit_pkt_manager_thread is set only after the pfil 549 * hooks have been removed, so only 1 extra iteration 550 * is needed to drain the queue. 551 */ 552 if (siftr_exit_pkt_manager_thread) 553 draining--; 554 } 555 556 mtx_unlock(&siftr_pkt_mgr_mtx); 557 558 /* Calls wakeup on this thread's struct thread ptr. */ 559 kthread_exit(); 560 } 561 562 /* 563 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that 564 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return. 565 * Return value >0 means the caller should skip processing this mbuf. 566 */ 567 static inline int 568 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss) 569 { 570 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL) 571 != NULL) { 572 if (dir == PFIL_IN) 573 ss->nskip_in_dejavu++; 574 else 575 ss->nskip_out_dejavu++; 576 577 return (1); 578 } else { 579 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR, 580 PACKET_TAG_SIFTR, 0, M_NOWAIT); 581 if (tag == NULL) { 582 if (dir == PFIL_IN) 583 ss->nskip_in_malloc++; 584 else 585 ss->nskip_out_malloc++; 586 587 return (1); 588 } 589 590 m_tag_prepend(m, tag); 591 } 592 593 return (0); 594 } 595 596 /* 597 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL 598 * otherwise. 599 */ 600 static inline struct inpcb * 601 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport, 602 uint16_t dport, int dir, struct siftr_stats *ss) 603 { 604 struct inpcb *inp; 605 606 /* We need the tcbinfo lock. */ 607 INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo); 608 609 if (dir == PFIL_IN) 610 inp = (ipver == INP_IPV4 ? 611 in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst, 612 dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 613 : 614 #ifdef SIFTR_IPV6 615 in6_pcblookup(&V_tcbinfo, 616 &((struct ip6_hdr *)ip)->ip6_src, sport, 617 &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB, 618 m->m_pkthdr.rcvif) 619 #else 620 NULL 621 #endif 622 ); 623 624 else 625 inp = (ipver == INP_IPV4 ? 626 in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src, 627 sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 628 : 629 #ifdef SIFTR_IPV6 630 in6_pcblookup(&V_tcbinfo, 631 &((struct ip6_hdr *)ip)->ip6_dst, dport, 632 &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB, 633 m->m_pkthdr.rcvif) 634 #else 635 NULL 636 #endif 637 ); 638 639 /* If we can't find the inpcb, bail. */ 640 if (inp == NULL) { 641 if (dir == PFIL_IN) 642 ss->nskip_in_inpcb++; 643 else 644 ss->nskip_out_inpcb++; 645 } 646 647 return (inp); 648 } 649 650 static inline uint32_t 651 siftr_get_flowid(struct inpcb *inp, int ipver, uint32_t *phashtype) 652 { 653 if (inp->inp_flowid == 0) { 654 #ifdef SIFTR_IPV6 655 if (ipver == INP_IPV6) { 656 return fib6_calc_packet_hash(&inp->in6p_laddr, 657 &inp->in6p_faddr, 658 inp->inp_lport, 659 inp->inp_fport, 660 IPPROTO_TCP, 661 phashtype); 662 } else 663 #endif 664 { 665 return fib4_calc_packet_hash(inp->inp_laddr, 666 inp->inp_faddr, 667 inp->inp_lport, 668 inp->inp_fport, 669 IPPROTO_TCP, 670 phashtype); 671 } 672 } else { 673 *phashtype = inp->inp_flowtype; 674 return inp->inp_flowid; 675 } 676 } 677 678 static inline void 679 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp, 680 int ipver, int dir, int inp_locally_locked) 681 { 682 pn->ipver = ipver; 683 pn->lport = inp->inp_lport; 684 pn->fport = inp->inp_fport; 685 pn->laddr = inp->inp_inc.inc_ie.ie_dependladdr; 686 pn->faddr = inp->inp_inc.inc_ie.ie_dependfaddr; 687 pn->snd_cwnd = tp->snd_cwnd; 688 pn->snd_wnd = tp->snd_wnd; 689 pn->rcv_wnd = tp->rcv_wnd; 690 pn->t_flags2 = tp->t_flags2; 691 pn->snd_ssthresh = tp->snd_ssthresh; 692 pn->snd_scale = tp->snd_scale; 693 pn->rcv_scale = tp->rcv_scale; 694 pn->conn_state = tp->t_state; 695 pn->mss = tp->t_maxseg; 696 pn->srtt = ((uint64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT; 697 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0; 698 pn->t_flags = tp->t_flags; 699 pn->rto = tp->t_rxtcur * tick; 700 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat; 701 pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd); 702 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat; 703 pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv); 704 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una; 705 pn->t_segqlen = tp->t_segqlen; 706 707 /* We've finished accessing the tcb so release the lock. */ 708 if (inp_locally_locked) 709 INP_RUNLOCK(inp); 710 711 pn->direction = (dir == PFIL_IN ? DIR_IN : DIR_OUT); 712 713 /* 714 * Significantly more accurate than using getmicrotime(), but slower! 715 * Gives true microsecond resolution at the expense of a hit to 716 * maximum pps throughput processing when SIFTR is loaded and enabled. 717 */ 718 microtime(&pn->tval); 719 TCP_PROBE1(siftr, pn); 720 } 721 722 /* 723 * pfil hook that is called for each IPv4 packet making its way through the 724 * stack in either direction. 725 * The pfil subsystem holds a non-sleepable mutex somewhere when 726 * calling our hook function, so we can't sleep at all. 727 * It's very important to use the M_NOWAIT flag with all function calls 728 * that support it so that they won't sleep, otherwise you get a panic. 729 */ 730 static pfil_return_t 731 siftr_chkpkt(struct mbuf **m, struct ifnet *ifp, int flags, 732 void *ruleset __unused, struct inpcb *inp) 733 { 734 struct pkt_node *pn; 735 struct ip *ip; 736 struct tcphdr *th; 737 struct tcpcb *tp; 738 struct siftr_stats *ss; 739 unsigned int ip_hl; 740 int inp_locally_locked, dir; 741 uint32_t hash_id, hash_type; 742 struct listhead *counter_list; 743 struct flow_hash_node *hash_node; 744 745 inp_locally_locked = 0; 746 dir = PFIL_DIR(flags); 747 ss = DPCPU_PTR(ss); 748 749 /* 750 * m_pullup is not required here because ip_{input|output} 751 * already do the heavy lifting for us. 752 */ 753 754 ip = mtod(*m, struct ip *); 755 756 /* Only continue processing if the packet is TCP. */ 757 if (ip->ip_p != IPPROTO_TCP) 758 goto ret; 759 760 /* 761 * Create a tcphdr struct starting at the correct offset 762 * in the IP packet. ip->ip_hl gives the ip header length 763 * in 4-byte words, so multiply it to get the size in bytes. 764 */ 765 ip_hl = (ip->ip_hl << 2); 766 th = (struct tcphdr *)((caddr_t)ip + ip_hl); 767 768 /* 769 * Only pkts selected by the tcp port filter 770 * can be inserted into the pkt_queue 771 */ 772 if ((siftr_port_filter != 0) && 773 (siftr_port_filter != ntohs(th->th_sport)) && 774 (siftr_port_filter != ntohs(th->th_dport))) { 775 goto ret; 776 } 777 778 /* 779 * If a kernel subsystem reinjects packets into the stack, our pfil 780 * hook will be called multiple times for the same packet. 781 * Make sure we only process unique packets. 782 */ 783 if (siftr_chkreinject(*m, dir, ss)) 784 goto ret; 785 786 if (dir == PFIL_IN) 787 ss->n_in++; 788 else 789 ss->n_out++; 790 791 /* 792 * If the pfil hooks don't provide a pointer to the 793 * inpcb, we need to find it ourselves and lock it. 794 */ 795 if (!inp) { 796 /* Find the corresponding inpcb for this pkt. */ 797 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport, 798 th->th_dport, dir, ss); 799 800 if (inp == NULL) 801 goto ret; 802 else 803 inp_locally_locked = 1; 804 } 805 806 INP_LOCK_ASSERT(inp); 807 808 /* Find the TCP control block that corresponds with this packet */ 809 tp = intotcpcb(inp); 810 811 /* 812 * If we can't find the TCP control block (happens occasionaly for a 813 * packet sent during the shutdown phase of a TCP connection), or the 814 * TCP control block has not initialized (happens during TCPS_SYN_SENT), 815 * bail. 816 */ 817 if (tp == NULL || tp->t_state < TCPS_ESTABLISHED) { 818 if (dir == PFIL_IN) 819 ss->nskip_in_tcpcb++; 820 else 821 ss->nskip_out_tcpcb++; 822 823 goto inp_unlock; 824 } 825 826 hash_id = siftr_get_flowid(inp, INP_IPV4, &hash_type); 827 counter_list = counter_hash + (hash_id & siftr_hashmask); 828 hash_node = siftr_find_flow(counter_list, hash_id); 829 830 /* If this flow hasn't been seen before, we create a new entry. */ 831 if (hash_node == NULL) { 832 struct flow_info info; 833 834 inet_ntoa_r(inp->inp_laddr, info.laddr); 835 inet_ntoa_r(inp->inp_faddr, info.faddr); 836 info.lport = ntohs(inp->inp_lport); 837 info.fport = ntohs(inp->inp_fport); 838 info.key = hash_id; 839 840 hash_node = siftr_new_hash_node(info, dir, ss); 841 } 842 843 if (hash_node == NULL) { 844 goto inp_unlock; 845 } 846 847 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 848 849 if (pn == NULL) { 850 if (dir == PFIL_IN) 851 ss->nskip_in_malloc++; 852 else 853 ss->nskip_out_malloc++; 854 855 goto inp_unlock; 856 } 857 858 pn->flowid = hash_id; 859 pn->flowtype = hash_type; 860 861 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked); 862 863 mtx_lock(&siftr_pkt_queue_mtx); 864 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 865 mtx_unlock(&siftr_pkt_queue_mtx); 866 goto ret; 867 868 inp_unlock: 869 if (inp_locally_locked) 870 INP_RUNLOCK(inp); 871 872 ret: 873 return (PFIL_PASS); 874 } 875 876 #ifdef SIFTR_IPV6 877 static pfil_return_t 878 siftr_chkpkt6(struct mbuf **m, struct ifnet *ifp, int flags, 879 void *ruleset __unused, struct inpcb *inp) 880 { 881 struct pkt_node *pn; 882 struct ip6_hdr *ip6; 883 struct tcphdr *th; 884 struct tcpcb *tp; 885 struct siftr_stats *ss; 886 unsigned int ip6_hl; 887 int inp_locally_locked, dir; 888 uint32_t hash_id, hash_type; 889 struct listhead *counter_list; 890 struct flow_hash_node *hash_node; 891 892 inp_locally_locked = 0; 893 dir = PFIL_DIR(flags); 894 ss = DPCPU_PTR(ss); 895 896 /* 897 * m_pullup is not required here because ip6_{input|output} 898 * already do the heavy lifting for us. 899 */ 900 901 ip6 = mtod(*m, struct ip6_hdr *); 902 903 /* 904 * Only continue processing if the packet is TCP 905 * XXX: We should follow the next header fields 906 * as shown on Pg 6 RFC 2460, but right now we'll 907 * only check pkts that have no extension headers. 908 */ 909 if (ip6->ip6_nxt != IPPROTO_TCP) 910 goto ret6; 911 912 /* 913 * Create a tcphdr struct starting at the correct offset 914 * in the ipv6 packet. 915 */ 916 ip6_hl = sizeof(struct ip6_hdr); 917 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl); 918 919 /* 920 * Only pkts selected by the tcp port filter 921 * can be inserted into the pkt_queue 922 */ 923 if ((siftr_port_filter != 0) && 924 (siftr_port_filter != ntohs(th->th_sport)) && 925 (siftr_port_filter != ntohs(th->th_dport))) { 926 goto ret6; 927 } 928 929 /* 930 * If a kernel subsystem reinjects packets into the stack, our pfil 931 * hook will be called multiple times for the same packet. 932 * Make sure we only process unique packets. 933 */ 934 if (siftr_chkreinject(*m, dir, ss)) 935 goto ret6; 936 937 if (dir == PFIL_IN) 938 ss->n_in++; 939 else 940 ss->n_out++; 941 942 /* 943 * For inbound packets, the pfil hooks don't provide a pointer to the 944 * inpcb, so we need to find it ourselves and lock it. 945 */ 946 if (!inp) { 947 /* Find the corresponding inpcb for this pkt. */ 948 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m, 949 th->th_sport, th->th_dport, dir, ss); 950 951 if (inp == NULL) 952 goto ret6; 953 else 954 inp_locally_locked = 1; 955 } 956 957 /* Find the TCP control block that corresponds with this packet. */ 958 tp = intotcpcb(inp); 959 960 /* 961 * If we can't find the TCP control block (happens occasionaly for a 962 * packet sent during the shutdown phase of a TCP connection), or the 963 * TCP control block has not initialized (happens during TCPS_SYN_SENT), 964 * bail. 965 */ 966 if (tp == NULL || tp->t_state < TCPS_ESTABLISHED) { 967 if (dir == PFIL_IN) 968 ss->nskip_in_tcpcb++; 969 else 970 ss->nskip_out_tcpcb++; 971 972 goto inp_unlock6; 973 } 974 975 hash_id = siftr_get_flowid(inp, INP_IPV6, &hash_type); 976 counter_list = counter_hash + (hash_id & siftr_hashmask); 977 hash_node = siftr_find_flow(counter_list, hash_id); 978 979 /* If this flow hasn't been seen before, we create a new entry. */ 980 if (!hash_node) { 981 struct flow_info info; 982 983 ip6_sprintf(info.laddr, &inp->in6p_laddr); 984 ip6_sprintf(info.faddr, &inp->in6p_faddr); 985 info.lport = ntohs(inp->inp_lport); 986 info.fport = ntohs(inp->inp_fport); 987 info.key = hash_id; 988 989 hash_node = siftr_new_hash_node(info, dir, ss); 990 } 991 992 if (!hash_node) { 993 goto inp_unlock6; 994 } 995 996 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 997 998 if (pn == NULL) { 999 if (dir == PFIL_IN) 1000 ss->nskip_in_malloc++; 1001 else 1002 ss->nskip_out_malloc++; 1003 1004 goto inp_unlock6; 1005 } 1006 1007 pn->flowid = hash_id; 1008 pn->flowtype = hash_type; 1009 1010 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked); 1011 1012 mtx_lock(&siftr_pkt_queue_mtx); 1013 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 1014 mtx_unlock(&siftr_pkt_queue_mtx); 1015 goto ret6; 1016 1017 inp_unlock6: 1018 if (inp_locally_locked) 1019 INP_RUNLOCK(inp); 1020 1021 ret6: 1022 return (PFIL_PASS); 1023 } 1024 #endif /* #ifdef SIFTR_IPV6 */ 1025 1026 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet_hook); 1027 #define V_siftr_inet_hook VNET(siftr_inet_hook) 1028 #ifdef SIFTR_IPV6 1029 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet6_hook); 1030 #define V_siftr_inet6_hook VNET(siftr_inet6_hook) 1031 #endif 1032 static int 1033 siftr_pfil(int action) 1034 { 1035 struct pfil_hook_args pha = { 1036 .pa_version = PFIL_VERSION, 1037 .pa_flags = PFIL_IN | PFIL_OUT, 1038 .pa_modname = "siftr", 1039 .pa_rulname = "default", 1040 }; 1041 struct pfil_link_args pla = { 1042 .pa_version = PFIL_VERSION, 1043 .pa_flags = PFIL_IN | PFIL_OUT | PFIL_HEADPTR | PFIL_HOOKPTR, 1044 }; 1045 1046 VNET_ITERATOR_DECL(vnet_iter); 1047 1048 VNET_LIST_RLOCK(); 1049 VNET_FOREACH(vnet_iter) { 1050 CURVNET_SET(vnet_iter); 1051 1052 if (action == HOOK) { 1053 pha.pa_mbuf_chk = siftr_chkpkt; 1054 pha.pa_type = PFIL_TYPE_IP4; 1055 V_siftr_inet_hook = pfil_add_hook(&pha); 1056 pla.pa_hook = V_siftr_inet_hook; 1057 pla.pa_head = V_inet_pfil_head; 1058 (void)pfil_link(&pla); 1059 #ifdef SIFTR_IPV6 1060 pha.pa_mbuf_chk = siftr_chkpkt6; 1061 pha.pa_type = PFIL_TYPE_IP6; 1062 V_siftr_inet6_hook = pfil_add_hook(&pha); 1063 pla.pa_hook = V_siftr_inet6_hook; 1064 pla.pa_head = V_inet6_pfil_head; 1065 (void)pfil_link(&pla); 1066 #endif 1067 } else if (action == UNHOOK) { 1068 pfil_remove_hook(V_siftr_inet_hook); 1069 #ifdef SIFTR_IPV6 1070 pfil_remove_hook(V_siftr_inet6_hook); 1071 #endif 1072 } 1073 CURVNET_RESTORE(); 1074 } 1075 VNET_LIST_RUNLOCK(); 1076 1077 return (0); 1078 } 1079 1080 static int 1081 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS) 1082 { 1083 struct alq *new_alq; 1084 int error; 1085 1086 error = sysctl_handle_string(oidp, arg1, arg2, req); 1087 1088 /* Check for error or same filename */ 1089 if (error != 0 || req->newptr == NULL || 1090 strncmp(siftr_logfile, arg1, arg2) == 0) 1091 goto done; 1092 1093 /* file name changed */ 1094 error = alq_open(&new_alq, arg1, curthread->td_ucred, 1095 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1096 if (error != 0) 1097 goto done; 1098 1099 /* 1100 * If disabled, siftr_alq == NULL so we simply close 1101 * the alq as we've proved it can be opened. 1102 * If enabled, close the existing alq and switch the old 1103 * for the new. 1104 */ 1105 if (siftr_alq == NULL) { 1106 alq_close(new_alq); 1107 } else { 1108 alq_close(siftr_alq); 1109 siftr_alq = new_alq; 1110 } 1111 1112 /* Update filename upon success */ 1113 strlcpy(siftr_logfile, arg1, arg2); 1114 done: 1115 return (error); 1116 } 1117 1118 static int 1119 siftr_manage_ops(uint8_t action) 1120 { 1121 struct siftr_stats totalss; 1122 struct timeval tval; 1123 struct flow_hash_node *counter, *tmp_counter; 1124 struct sbuf *s; 1125 int i, error; 1126 uint32_t bytes_to_write, total_skipped_pkts; 1127 1128 error = 0; 1129 total_skipped_pkts = 0; 1130 1131 /* Init an autosizing sbuf that initially holds 200 chars. */ 1132 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL) 1133 return (-1); 1134 1135 if (action == SIFTR_ENABLE && siftr_pkt_manager_thr == NULL) { 1136 /* 1137 * Create our alq 1138 * XXX: We should abort if alq_open fails! 1139 */ 1140 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred, 1141 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1142 1143 STAILQ_INIT(&pkt_queue); 1144 1145 DPCPU_ZERO(ss); 1146 1147 siftr_exit_pkt_manager_thread = 0; 1148 1149 kthread_add(&siftr_pkt_manager_thread, NULL, NULL, 1150 &siftr_pkt_manager_thr, RFNOWAIT, 0, 1151 "siftr_pkt_manager_thr"); 1152 1153 siftr_pfil(HOOK); 1154 1155 microtime(&tval); 1156 1157 sbuf_printf(s, 1158 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t" 1159 "siftrver=%s\tsysname=%s\tsysver=%u\tipmode=%u\n", 1160 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, 1161 SYS_NAME, __FreeBSD_version, SIFTR_IPMODE); 1162 1163 sbuf_finish(s); 1164 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK); 1165 1166 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) { 1167 /* 1168 * Remove the pfil hook functions. All threads currently in 1169 * the hook functions are allowed to exit before siftr_pfil() 1170 * returns. 1171 */ 1172 siftr_pfil(UNHOOK); 1173 1174 /* This will block until the pkt manager thread unlocks it. */ 1175 mtx_lock(&siftr_pkt_mgr_mtx); 1176 1177 /* Tell the pkt manager thread that it should exit now. */ 1178 siftr_exit_pkt_manager_thread = 1; 1179 1180 /* 1181 * Wake the pkt_manager thread so it realises that 1182 * siftr_exit_pkt_manager_thread == 1 and exits gracefully. 1183 * The wakeup won't be delivered until we unlock 1184 * siftr_pkt_mgr_mtx so this isn't racy. 1185 */ 1186 wakeup(&wait_for_pkt); 1187 1188 /* Wait for the pkt_manager thread to exit. */ 1189 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT, 1190 "thrwait", 0); 1191 1192 siftr_pkt_manager_thr = NULL; 1193 mtx_unlock(&siftr_pkt_mgr_mtx); 1194 1195 totalss.n_in = DPCPU_VARSUM(ss, n_in); 1196 totalss.n_out = DPCPU_VARSUM(ss, n_out); 1197 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc); 1198 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc); 1199 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb); 1200 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb); 1201 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb); 1202 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb); 1203 1204 total_skipped_pkts = totalss.nskip_in_malloc + 1205 totalss.nskip_out_malloc + totalss.nskip_in_tcpcb + 1206 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb + 1207 totalss.nskip_out_inpcb; 1208 1209 microtime(&tval); 1210 1211 sbuf_printf(s, 1212 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t" 1213 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t" 1214 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t" 1215 "num_outbound_skipped_pkts_malloc=%u\t" 1216 "num_inbound_skipped_pkts_tcpcb=%u\t" 1217 "num_outbound_skipped_pkts_tcpcb=%u\t" 1218 "num_inbound_skipped_pkts_inpcb=%u\t" 1219 "num_outbound_skipped_pkts_inpcb=%u\t" 1220 "total_skipped_tcp_pkts=%u\tflow_list=", 1221 (intmax_t)tval.tv_sec, 1222 tval.tv_usec, 1223 (uintmax_t)totalss.n_in, 1224 (uintmax_t)totalss.n_out, 1225 (uintmax_t)(totalss.n_in + totalss.n_out), 1226 totalss.nskip_in_malloc, 1227 totalss.nskip_out_malloc, 1228 totalss.nskip_in_tcpcb, 1229 totalss.nskip_out_tcpcb, 1230 totalss.nskip_in_inpcb, 1231 totalss.nskip_out_inpcb, 1232 total_skipped_pkts); 1233 1234 /* 1235 * Iterate over the flow hash, printing a summary of each 1236 * flow seen and freeing any malloc'd memory. 1237 * The hash consists of an array of LISTs (man 3 queue). 1238 */ 1239 for (i = 0; i <= siftr_hashmask; i++) { 1240 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes, 1241 tmp_counter) { 1242 sbuf_printf(s, "%s;%hu-%s;%hu,", 1243 counter->const_info.laddr, 1244 counter->const_info.lport, 1245 counter->const_info.faddr, 1246 counter->const_info.fport); 1247 1248 free(counter, M_SIFTR_HASHNODE); 1249 } 1250 1251 LIST_INIT(counter_hash + i); 1252 } 1253 1254 sbuf_printf(s, "\n"); 1255 sbuf_finish(s); 1256 1257 i = 0; 1258 do { 1259 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i); 1260 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK); 1261 i += bytes_to_write; 1262 } while (i < sbuf_len(s)); 1263 1264 alq_close(siftr_alq); 1265 siftr_alq = NULL; 1266 } else 1267 error = EINVAL; 1268 1269 sbuf_delete(s); 1270 1271 /* 1272 * XXX: Should be using ret to check if any functions fail 1273 * and set error appropriately 1274 */ 1275 1276 return (error); 1277 } 1278 1279 static int 1280 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS) 1281 { 1282 int error; 1283 uint32_t new; 1284 1285 new = siftr_enabled; 1286 error = sysctl_handle_int(oidp, &new, 0, req); 1287 if (error == 0 && req->newptr != NULL) { 1288 if (new > 1) 1289 return (EINVAL); 1290 else if (new != siftr_enabled) { 1291 if ((error = siftr_manage_ops(new)) == 0) { 1292 siftr_enabled = new; 1293 } else { 1294 siftr_manage_ops(SIFTR_DISABLE); 1295 } 1296 } 1297 } 1298 1299 return (error); 1300 } 1301 1302 static void 1303 siftr_shutdown_handler(void *arg, int howto) 1304 { 1305 if ((howto & RB_NOSYNC) != 0 || SCHEDULER_STOPPED()) 1306 return; 1307 1308 if (siftr_enabled == 1) { 1309 siftr_manage_ops(SIFTR_DISABLE); 1310 } 1311 } 1312 1313 /* 1314 * Module is being unloaded or machine is shutting down. Take care of cleanup. 1315 */ 1316 static int 1317 deinit_siftr(void) 1318 { 1319 /* Cleanup. */ 1320 siftr_manage_ops(SIFTR_DISABLE); 1321 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask); 1322 mtx_destroy(&siftr_pkt_queue_mtx); 1323 mtx_destroy(&siftr_pkt_mgr_mtx); 1324 1325 return (0); 1326 } 1327 1328 /* 1329 * Module has just been loaded into the kernel. 1330 */ 1331 static int 1332 init_siftr(void) 1333 { 1334 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL, 1335 SHUTDOWN_PRI_FIRST); 1336 1337 /* Initialise our flow counter hash table. */ 1338 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR, 1339 &siftr_hashmask); 1340 1341 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF); 1342 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF); 1343 1344 /* Print message to the user's current terminal. */ 1345 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n" 1346 " http://caia.swin.edu.au/urp/newtcp\n\n", 1347 MODVERSION_STR); 1348 1349 return (0); 1350 } 1351 1352 /* 1353 * This is the function that is called to load and unload the module. 1354 * When the module is loaded, this function is called once with 1355 * "what" == MOD_LOAD 1356 * When the module is unloaded, this function is called twice with 1357 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second 1358 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command, 1359 * this function is called once with "what" = MOD_SHUTDOWN 1360 * When the system is shut down, the handler isn't called until the very end 1361 * of the shutdown sequence i.e. after the disks have been synced. 1362 */ 1363 static int 1364 siftr_load_handler(module_t mod, int what, void *arg) 1365 { 1366 int ret; 1367 1368 switch (what) { 1369 case MOD_LOAD: 1370 ret = init_siftr(); 1371 break; 1372 1373 case MOD_QUIESCE: 1374 case MOD_SHUTDOWN: 1375 ret = deinit_siftr(); 1376 break; 1377 1378 case MOD_UNLOAD: 1379 ret = 0; 1380 break; 1381 1382 default: 1383 ret = EINVAL; 1384 break; 1385 } 1386 1387 return (ret); 1388 } 1389 1390 static moduledata_t siftr_mod = { 1391 .name = "siftr", 1392 .evhand = siftr_load_handler, 1393 }; 1394 1395 /* 1396 * Param 1: name of the kernel module 1397 * Param 2: moduledata_t struct containing info about the kernel module 1398 * and the execution entry point for the module 1399 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h 1400 * Defines the module initialisation order 1401 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h 1402 * Defines the initialisation order of this kld relative to others 1403 * within the same subsystem as defined by param 3 1404 */ 1405 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY); 1406 MODULE_DEPEND(siftr, alq, 1, 1, 1); 1407 MODULE_VERSION(siftr, MODVERSION); 1408