2 * Copyright (c) 2007-2009, Centre for Advanced Internet Architectures
3 * Swinburne University of Technology, Melbourne, Australia
4 * (CRICOS number 00111D).
5 * Copyright (c) 2009-2010, The FreeBSD Foundation
8 * Portions of this software were developed at the Centre for Advanced
9 * Internet Architectures, Swinburne University of Technology, Melbourne,
10 * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation.
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 /******************************************************
35 * Statistical Information For TCP Research (SIFTR)
37 * A FreeBSD kernel module that adds very basic intrumentation to the
38 * TCP stack, allowing internal stats to be recorded to a log file
39 * for experimental, debugging and performance analysis purposes.
41 * SIFTR was first released in 2007 by James Healy and Lawrence Stewart whilst
42 * working on the NewTCP research project at Swinburne University's Centre for
43 * Advanced Internet Architectures, Melbourne, Australia, which was made
44 * possible in part by a grant from the Cisco University Research Program Fund
45 * at Community Foundation Silicon Valley. More details are available at:
46 * http://caia.swin.edu.au/urp/newtcp/
48 * Work on SIFTR v1.2.x was sponsored by the FreeBSD Foundation as part of
49 * the "Enhancing the FreeBSD TCP Implementation" project 2008-2009.
50 * More details are available at:
51 * http://www.freebsdfoundation.org/
52 * http://caia.swin.edu.au/freebsd/etcp09/
54 * Lawrence Stewart is the current maintainer, and all contact regarding
55 * SIFTR should be directed to him via email: lastewart@swin.edu.au
57 * Initial release date: June 2007
58 * Most recent update: June 2010
59 ******************************************************/
61 #include <sys/cdefs.h>
62 __FBSDID("$FreeBSD$");
64 #include <sys/param.h>
66 #include <sys/errno.h>
68 #include <sys/kernel.h>
69 #include <sys/kthread.h>
72 #include <sys/module.h>
73 #include <sys/mutex.h>
78 #include <sys/socket.h>
79 #include <sys/socketvar.h>
80 #include <sys/sysctl.h>
81 #include <sys/unistd.h>
86 #include <netinet/in.h>
87 #include <netinet/in_pcb.h>
88 #include <netinet/in_systm.h>
89 #include <netinet/in_var.h>
90 #include <netinet/ip.h>
91 #include <netinet/tcp_var.h>
94 #include <netinet/ip6.h>
95 #include <netinet6/in6_pcb.h>
96 #endif /* SIFTR_IPV6 */
98 #include <machine/in_cksum.h>
101 * Three digit version number refers to X.Y.Z where:
102 * X is the major version number
103 * Y is bumped to mark backwards incompatible changes
104 * Z is bumped to mark backwards compatible changes
107 #define V_BACKBREAK 2
108 #define V_BACKCOMPAT 3
109 #define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT))
110 #define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \
111 __XSTRING(V_BACKCOMPAT)
115 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536
116 #define SYS_NAME "FreeBSD"
117 #define PACKET_TAG_SIFTR 100
118 #define PACKET_COOKIE_SIFTR 21749576
119 #define SIFTR_LOG_FILE_MODE 0644
120 #define SIFTR_DISABLE 0
121 #define SIFTR_ENABLE 1
124 * Hard upper limit on the length of log messages. Bump this up if you add new
125 * data fields such that the line length could exceed the below value.
127 #define MAX_LOG_MSG_LEN 200
128 /* XXX: Make this a sysctl tunable. */
129 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN)
132 * 1 byte for IP version
133 * IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes
134 * IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes
137 #define FLOW_KEY_LEN 37
139 #define FLOW_KEY_LEN 13
143 #define SIFTR_IPMODE 6
145 #define SIFTR_IPMODE 4
149 #define CAST_PTR_INT(X) (*((int*)(X)))
151 #define UPPER_SHORT(X) (((X) & 0xFFFF0000) >> 16)
152 #define LOWER_SHORT(X) ((X) & 0x0000FFFF)
154 #define FIRST_OCTET(X) (((X) & 0xFF000000) >> 24)
155 #define SECOND_OCTET(X) (((X) & 0x00FF0000) >> 16)
156 #define THIRD_OCTET(X) (((X) & 0x0000FF00) >> 8)
157 #define FOURTH_OCTET(X) ((X) & 0x000000FF)
159 MALLOC_DECLARE(M_SIFTR);
160 MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR");
162 MALLOC_DECLARE(M_SIFTR_PKTNODE);
163 MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode", "SIFTR pkt_node struct");
165 MALLOC_DECLARE(M_SIFTR_HASHNODE);
166 MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode", "SIFTR flow_hash_node struct");
168 /* Used as links in the pkt manager queue. */
170 /* Timestamp of pkt as noted in the pfil hook. */
172 /* Direction pkt is travelling; either PFIL_IN or PFIL_OUT. */
174 /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */
176 /* Hash of the pkt which triggered the log message. */
178 /* Local/foreign IP address. */
180 uint32_t ip_laddr[4];
181 uint32_t ip_faddr[4];
186 /* Local TCP port. */
187 uint16_t tcp_localport;
188 /* Foreign TCP port. */
189 uint16_t tcp_foreignport;
190 /* Congestion Window (bytes). */
192 /* Sending Window (bytes). */
194 /* Receive Window (bytes). */
196 /* Bandwidth Controlled Window (bytes). */
198 /* Slow Start Threshold (bytes). */
200 /* Current state of the TCP FSM. */
202 /* Max Segment Size (bytes). */
205 * Smoothed RTT stored as found in the TCP control block
206 * in units of (TCP_RTT_SCALE*hz).
209 /* Is SACK enabled? */
211 /* Window scaling for snd window. */
213 /* Window scaling for recv window. */
215 /* TCP control block flags. */
217 /* Retransmit timeout length. */
219 /* Size of the TCP send buffer in bytes. */
220 u_int snd_buf_hiwater;
221 /* Current num bytes in the send socket buffer. */
223 /* Size of the TCP receive buffer in bytes. */
224 u_int rcv_buf_hiwater;
225 /* Current num bytes in the receive socket buffer. */
227 /* Number of bytes inflight that we are waiting on ACKs for. */
228 u_int sent_inflight_bytes;
229 /* Link to next pkt_node in the list. */
230 STAILQ_ENTRY(pkt_node) nodes;
233 struct flow_hash_node
236 uint8_t key[FLOW_KEY_LEN];
237 LIST_ENTRY(flow_hash_node) nodes;
242 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */
245 /* # pkts skipped due to failed malloc calls. */
246 uint32_t nskip_in_malloc;
247 uint32_t nskip_out_malloc;
248 /* # pkts skipped due to failed mtx acquisition. */
249 uint32_t nskip_in_mtx;
250 uint32_t nskip_out_mtx;
251 /* # pkts skipped due to failed inpcb lookups. */
252 uint32_t nskip_in_inpcb;
253 uint32_t nskip_out_inpcb;
254 /* # pkts skipped due to failed tcpcb lookups. */
255 uint32_t nskip_in_tcpcb;
256 uint32_t nskip_out_tcpcb;
257 /* # pkts skipped due to stack reinjection. */
258 uint32_t nskip_in_dejavu;
259 uint32_t nskip_out_dejavu;
262 static DPCPU_DEFINE(struct siftr_stats, ss);
264 static volatile unsigned int siftr_exit_pkt_manager_thread = 0;
265 static unsigned int siftr_enabled = 0;
266 static unsigned int siftr_pkts_per_log = 1;
267 static unsigned int siftr_generate_hashes = 0;
268 /* static unsigned int siftr_binary_log = 0; */
269 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log";
270 static u_long siftr_hashmask;
271 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue);
272 LIST_HEAD(listhead, flow_hash_node) *counter_hash;
273 static int wait_for_pkt;
274 static struct alq *siftr_alq = NULL;
275 static struct mtx siftr_pkt_queue_mtx;
276 static struct mtx siftr_pkt_mgr_mtx;
277 static struct thread *siftr_pkt_manager_thr = NULL;
279 * pfil.h defines PFIL_IN as 1 and PFIL_OUT as 2,
280 * which we use as an index into this array.
282 static char direction[3] = {'\0', 'i','o'};
284 /* Required function prototypes. */
285 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS);
286 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS);
289 /* Declare the net.inet.siftr sysctl tree and populate it. */
291 SYSCTL_DECL(_net_inet_siftr);
293 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW, NULL,
294 "siftr related settings");
296 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, CTLTYPE_UINT|CTLFLAG_RW,
297 &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU",
298 "switch siftr module operations on/off");
300 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, CTLTYPE_STRING|CTLFLAG_RW,
301 &siftr_logfile, sizeof(siftr_logfile), &siftr_sysctl_logfile_name_handler,
302 "A", "file to save siftr log messages to");
304 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW,
305 &siftr_pkts_per_log, 1,
306 "number of packets between generating a log message");
308 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW,
309 &siftr_generate_hashes, 0,
310 "enable packet hash generation");
313 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW,
314 &siftr_binary_log, 0,
315 "write log files in binary instead of ascii");
319 /* Begin functions. */
322 siftr_process_pkt(struct pkt_node * pkt_node)
324 struct flow_hash_node *hash_node;
325 struct listhead *counter_list;
326 struct siftr_stats *ss;
328 uint8_t key[FLOW_KEY_LEN];
329 uint8_t found_match, key_offset;
337 * Create the key that will be used to create a hash index
338 * into our hash table. Our key consists of:
339 * ipversion, localip, localport, foreignip, foreignport
341 key[0] = pkt_node->ipver;
342 memcpy(key + key_offset, &pkt_node->ip_laddr,
343 sizeof(pkt_node->ip_laddr));
344 key_offset += sizeof(pkt_node->ip_laddr);
345 memcpy(key + key_offset, &pkt_node->tcp_localport,
346 sizeof(pkt_node->tcp_localport));
347 key_offset += sizeof(pkt_node->tcp_localport);
348 memcpy(key + key_offset, &pkt_node->ip_faddr,
349 sizeof(pkt_node->ip_faddr));
350 key_offset += sizeof(pkt_node->ip_faddr);
351 memcpy(key + key_offset, &pkt_node->tcp_foreignport,
352 sizeof(pkt_node->tcp_foreignport));
354 counter_list = counter_hash +
355 (hash32_buf(key, sizeof(key), 0) & siftr_hashmask);
358 * If the list is not empty i.e. the hash index has
359 * been used by another flow previously.
361 if (LIST_FIRST(counter_list) != NULL) {
363 * Loop through the hash nodes in the list.
364 * There should normally only be 1 hash node in the list,
365 * except if there have been collisions at the hash index
366 * computed by hash32_buf().
368 LIST_FOREACH(hash_node, counter_list, nodes) {
370 * Check if the key for the pkt we are currently
371 * processing is the same as the key stored in the
372 * hash node we are currently processing.
373 * If they are the same, then we've found the
374 * hash node that stores the counter for the flow
375 * the pkt belongs to.
377 if (memcmp(hash_node->key, key, sizeof(key)) == 0) {
384 /* If this flow hash hasn't been seen before or we have a collision. */
385 if (hash_node == NULL || !found_match) {
386 /* Create a new hash node to store the flow's counter. */
387 hash_node = malloc(sizeof(struct flow_hash_node),
388 M_SIFTR_HASHNODE, M_WAITOK);
390 if (hash_node != NULL) {
391 /* Initialise our new hash node list entry. */
392 hash_node->counter = 0;
393 memcpy(hash_node->key, key, sizeof(key));
394 LIST_INSERT_HEAD(counter_list, hash_node, nodes);
397 if (pkt_node->direction == PFIL_IN)
398 ss->nskip_in_malloc++;
400 ss->nskip_out_malloc++;
404 } else if (siftr_pkts_per_log > 1) {
406 * Taking the remainder of the counter divided
407 * by the current value of siftr_pkts_per_log
408 * and storing that in counter provides a neat
409 * way to modulate the frequency of log
410 * messages being written to the log file.
412 hash_node->counter = (hash_node->counter + 1) %
416 * If we have not seen enough packets since the last time
417 * we wrote a log message for this connection, return.
419 if (hash_node->counter > 0)
423 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK);
426 return; /* Should only happen if the ALQ is shutting down. */
429 pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]);
430 pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]);
432 if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */
433 pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]);
434 pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]);
435 pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]);
436 pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]);
437 pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]);
438 pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]);
440 /* Construct an IPv6 log message. */
441 log_buf->ae_bytesused = snprintf(log_buf->ae_data,
443 "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:"
444 "%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,"
445 "%u,%d,%u,%u,%u,%u,%u\n",
446 direction[pkt_node->direction],
448 pkt_node->tval.tv_sec,
449 pkt_node->tval.tv_usec,
450 UPPER_SHORT(pkt_node->ip_laddr[0]),
451 LOWER_SHORT(pkt_node->ip_laddr[0]),
452 UPPER_SHORT(pkt_node->ip_laddr[1]),
453 LOWER_SHORT(pkt_node->ip_laddr[1]),
454 UPPER_SHORT(pkt_node->ip_laddr[2]),
455 LOWER_SHORT(pkt_node->ip_laddr[2]),
456 UPPER_SHORT(pkt_node->ip_laddr[3]),
457 LOWER_SHORT(pkt_node->ip_laddr[3]),
458 ntohs(pkt_node->tcp_localport),
459 UPPER_SHORT(pkt_node->ip_faddr[0]),
460 LOWER_SHORT(pkt_node->ip_faddr[0]),
461 UPPER_SHORT(pkt_node->ip_faddr[1]),
462 LOWER_SHORT(pkt_node->ip_faddr[1]),
463 UPPER_SHORT(pkt_node->ip_faddr[2]),
464 LOWER_SHORT(pkt_node->ip_faddr[2]),
465 UPPER_SHORT(pkt_node->ip_faddr[3]),
466 LOWER_SHORT(pkt_node->ip_faddr[3]),
467 ntohs(pkt_node->tcp_foreignport),
468 pkt_node->snd_ssthresh,
475 pkt_node->conn_state,
476 pkt_node->max_seg_size,
477 pkt_node->smoothed_rtt,
478 pkt_node->sack_enabled,
480 pkt_node->rxt_length,
481 pkt_node->snd_buf_hiwater,
482 pkt_node->snd_buf_cc,
483 pkt_node->rcv_buf_hiwater,
484 pkt_node->rcv_buf_cc,
485 pkt_node->sent_inflight_bytes);
486 } else { /* IPv4 packet */
487 pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]);
488 pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]);
489 pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]);
490 pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]);
491 pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]);
492 pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]);
493 pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]);
494 pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]);
495 #endif /* SIFTR_IPV6 */
497 /* Construct an IPv4 log message. */
498 log_buf->ae_bytesused = snprintf(log_buf->ae_data,
500 "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld,"
501 "%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u\n",
502 direction[pkt_node->direction],
504 (intmax_t)pkt_node->tval.tv_sec,
505 pkt_node->tval.tv_usec,
506 pkt_node->ip_laddr[0],
507 pkt_node->ip_laddr[1],
508 pkt_node->ip_laddr[2],
509 pkt_node->ip_laddr[3],
510 ntohs(pkt_node->tcp_localport),
511 pkt_node->ip_faddr[0],
512 pkt_node->ip_faddr[1],
513 pkt_node->ip_faddr[2],
514 pkt_node->ip_faddr[3],
515 ntohs(pkt_node->tcp_foreignport),
516 pkt_node->snd_ssthresh,
523 pkt_node->conn_state,
524 pkt_node->max_seg_size,
525 pkt_node->smoothed_rtt,
526 pkt_node->sack_enabled,
528 pkt_node->rxt_length,
529 pkt_node->snd_buf_hiwater,
530 pkt_node->snd_buf_cc,
531 pkt_node->rcv_buf_hiwater,
532 pkt_node->rcv_buf_cc,
533 pkt_node->sent_inflight_bytes);
538 alq_post_flags(siftr_alq, log_buf, 0);
543 siftr_pkt_manager_thread(void *arg)
545 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue =
546 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue);
547 struct pkt_node *pkt_node, *pkt_node_temp;
552 mtx_lock(&siftr_pkt_mgr_mtx);
554 /* draining == 0 when queue has been flushed and it's safe to exit. */
557 * Sleep until we are signalled to wake because thread has
558 * been told to exit or until 1 tick has passed.
560 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait",
563 /* Gain exclusive access to the pkt_node queue. */
564 mtx_lock(&siftr_pkt_queue_mtx);
567 * Move pkt_queue to tmp_pkt_queue, which leaves
568 * pkt_queue empty and ready to receive more pkt_nodes.
570 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue);
573 * We've finished making changes to the list. Unlock it
574 * so the pfil hooks can continue queuing pkt_nodes.
576 mtx_unlock(&siftr_pkt_queue_mtx);
579 * We can't hold a mutex whilst calling siftr_process_pkt
580 * because ALQ might sleep waiting for buffer space.
582 mtx_unlock(&siftr_pkt_mgr_mtx);
584 /* Flush all pkt_nodes to the log file. */
585 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes,
587 siftr_process_pkt(pkt_node);
588 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes);
589 free(pkt_node, M_SIFTR_PKTNODE);
592 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue),
593 ("SIFTR tmp_pkt_queue not empty after flush"));
595 mtx_lock(&siftr_pkt_mgr_mtx);
598 * If siftr_exit_pkt_manager_thread gets set during the window
599 * where we are draining the tmp_pkt_queue above, there might
600 * still be pkts in pkt_queue that need to be drained.
601 * Allow one further iteration to occur after
602 * siftr_exit_pkt_manager_thread has been set to ensure
603 * pkt_queue is completely empty before we kill the thread.
605 * siftr_exit_pkt_manager_thread is set only after the pfil
606 * hooks have been removed, so only 1 extra iteration
607 * is needed to drain the queue.
609 if (siftr_exit_pkt_manager_thread)
613 mtx_unlock(&siftr_pkt_mgr_mtx);
615 /* Calls wakeup on this thread's struct thread ptr. */
621 hash_pkt(struct mbuf *m, uint32_t offset)
627 while (m != NULL && offset > m->m_len) {
629 * The IP packet payload does not start in this mbuf, so
630 * need to figure out which mbuf it starts in and what offset
631 * into the mbuf's data region the payload starts at.
638 /* Ensure there is data in the mbuf */
639 if ((m->m_len - offset) > 0)
640 hash = hash32_buf(m->m_data + offset,
641 m->m_len - offset, hash);
652 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that
653 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return.
654 * Return value >0 means the caller should skip processing this mbuf.
657 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss)
659 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL)
662 ss->nskip_in_dejavu++;
664 ss->nskip_out_dejavu++;
668 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR,
669 PACKET_TAG_SIFTR, 0, M_NOWAIT);
672 ss->nskip_in_malloc++;
674 ss->nskip_out_malloc++;
679 m_tag_prepend(m, tag);
687 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL
690 static inline struct inpcb *
691 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport,
692 uint16_t dport, int dir, struct siftr_stats *ss)
696 /* We need the tcbinfo lock. */
697 INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
698 INP_INFO_RLOCK(&V_tcbinfo);
701 inp = (ipver == INP_IPV4 ?
702 in_pcblookup_hash(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst,
703 dport, 0, m->m_pkthdr.rcvif)
706 in6_pcblookup_hash(&V_tcbinfo,
707 &((struct ip6_hdr *)ip)->ip6_src, sport,
708 &((struct ip6_hdr *)ip)->ip6_dst, dport, 0,
716 inp = (ipver == INP_IPV4 ?
717 in_pcblookup_hash(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src,
718 sport, 0, m->m_pkthdr.rcvif)
721 in6_pcblookup_hash(&V_tcbinfo,
722 &((struct ip6_hdr *)ip)->ip6_dst, dport,
723 &((struct ip6_hdr *)ip)->ip6_src, sport, 0,
730 /* If we can't find the inpcb, bail. */
733 ss->nskip_in_inpcb++;
735 ss->nskip_out_inpcb++;
737 INP_INFO_RUNLOCK(&V_tcbinfo);
739 /* Acquire the inpcb lock. */
740 INP_UNLOCK_ASSERT(inp);
742 INP_INFO_RUNLOCK(&V_tcbinfo);
750 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp,
751 int ipver, int dir, int inp_locally_locked)
754 if (ipver == INP_IPV4) {
755 pn->ip_laddr[3] = inp->inp_laddr.s_addr;
756 pn->ip_faddr[3] = inp->inp_faddr.s_addr;
758 *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr;
759 *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr;
763 pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0];
764 pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1];
765 pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2];
766 pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3];
767 pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0];
768 pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1];
769 pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2];
770 pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3];
773 pn->tcp_localport = inp->inp_lport;
774 pn->tcp_foreignport = inp->inp_fport;
775 pn->snd_cwnd = tp->snd_cwnd;
776 pn->snd_wnd = tp->snd_wnd;
777 pn->rcv_wnd = tp->rcv_wnd;
778 pn->snd_bwnd = tp->snd_bwnd;
779 pn->snd_ssthresh = tp->snd_ssthresh;
780 pn->snd_scale = tp->snd_scale;
781 pn->rcv_scale = tp->rcv_scale;
782 pn->conn_state = tp->t_state;
783 pn->max_seg_size = tp->t_maxseg;
784 pn->smoothed_rtt = tp->t_srtt;
785 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0;
786 pn->flags = tp->t_flags;
787 pn->rxt_length = tp->t_rxtcur;
788 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat;
789 pn->snd_buf_cc = inp->inp_socket->so_snd.sb_cc;
790 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat;
791 pn->rcv_buf_cc = inp->inp_socket->so_rcv.sb_cc;
792 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una;
794 /* We've finished accessing the tcb so release the lock. */
795 if (inp_locally_locked)
802 * Significantly more accurate than using getmicrotime(), but slower!
803 * Gives true microsecond resolution at the expense of a hit to
804 * maximum pps throughput processing when SIFTR is loaded and enabled.
806 microtime(&pn->tval);
811 * pfil hook that is called for each IPv4 packet making its way through the
812 * stack in either direction.
813 * The pfil subsystem holds a non-sleepable mutex somewhere when
814 * calling our hook function, so we can't sleep at all.
815 * It's very important to use the M_NOWAIT flag with all function calls
816 * that support it so that they won't sleep, otherwise you get a panic.
819 siftr_chkpkt(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
826 struct siftr_stats *ss;
828 int inp_locally_locked;
830 inp_locally_locked = 0;
834 * m_pullup is not required here because ip_{input|output}
835 * already do the heavy lifting for us.
838 ip = mtod(*m, struct ip *);
840 /* Only continue processing if the packet is TCP. */
841 if (ip->ip_p != IPPROTO_TCP)
845 * If a kernel subsystem reinjects packets into the stack, our pfil
846 * hook will be called multiple times for the same packet.
847 * Make sure we only process unique packets.
849 if (siftr_chkreinject(*m, dir, ss))
858 * Create a tcphdr struct starting at the correct offset
859 * in the IP packet. ip->ip_hl gives the ip header length
860 * in 4-byte words, so multiply it to get the size in bytes.
862 ip_hl = (ip->ip_hl << 2);
863 th = (struct tcphdr *)((caddr_t)ip + ip_hl);
866 * If the pfil hooks don't provide a pointer to the
867 * inpcb, we need to find it ourselves and lock it.
870 /* Find the corresponding inpcb for this pkt. */
871 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport,
872 th->th_dport, dir, ss);
877 inp_locally_locked = 1;
880 INP_LOCK_ASSERT(inp);
882 /* Find the TCP control block that corresponds with this packet */
886 * If we can't find the TCP control block (happens occasionaly for a
887 * packet sent during the shutdown phase of a TCP connection),
888 * or we're in the timewait state, bail
890 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
892 ss->nskip_in_tcpcb++;
894 ss->nskip_out_tcpcb++;
899 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
903 ss->nskip_in_malloc++;
905 ss->nskip_out_malloc++;
910 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked);
912 if (siftr_generate_hashes) {
913 if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) {
915 * For outbound packets, the TCP checksum isn't
916 * calculated yet. This is a problem for our packet
917 * hashing as the receiver will calc a different hash
918 * to ours if we don't include the correct TCP checksum
919 * in the bytes being hashed. To work around this
920 * problem, we manually calc the TCP checksum here in
921 * software. We unset the CSUM_TCP flag so the lower
922 * layers don't recalc it.
924 (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP;
927 * Calculate the TCP checksum in software and assign
928 * to correct TCP header field, which will follow the
929 * packet mbuf down the stack. The trick here is that
930 * tcp_output() sets th->th_sum to the checksum of the
931 * pseudo header for us already. Because of the nature
932 * of the checksumming algorithm, we can sum over the
933 * entire IP payload (i.e. TCP header and data), which
934 * will include the already calculated pseduo header
935 * checksum, thus giving us the complete TCP checksum.
937 * To put it in simple terms, if checksum(1,2,3,4)=10,
938 * then checksum(1,2,3,4,5) == checksum(10,5).
939 * This property is what allows us to "cheat" and
940 * checksum only the IP payload which has the TCP
941 * th_sum field populated with the pseudo header's
942 * checksum, and not need to futz around checksumming
943 * pseudo header bytes and TCP header/data in one hit.
944 * Refer to RFC 1071 for more info.
946 * NB: in_cksum_skip(struct mbuf *m, int len, int skip)
947 * in_cksum_skip 2nd argument is NOT the number of
948 * bytes to read from the mbuf at "skip" bytes offset
949 * from the start of the mbuf (very counter intuitive!).
950 * The number of bytes to read is calculated internally
951 * by the function as len-skip i.e. to sum over the IP
952 * payload (TCP header + data) bytes, it is INCORRECT
953 * to call the function like this:
954 * in_cksum_skip(at, ip->ip_len - offset, offset)
955 * Rather, it should be called like this:
956 * in_cksum_skip(at, ip->ip_len, offset)
957 * which means read "ip->ip_len - offset" bytes from
958 * the mbuf cluster "at" at offset "offset" bytes from
959 * the beginning of the "at" mbuf's data pointer.
961 th->th_sum = in_cksum_skip(*m, ip->ip_len, ip_hl);
965 * XXX: Having to calculate the checksum in software and then
966 * hash over all bytes is really inefficient. Would be nice to
967 * find a way to create the hash and checksum in the same pass
970 pn->hash = hash_pkt(*m, ip_hl);
973 mtx_lock(&siftr_pkt_queue_mtx);
974 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
975 mtx_unlock(&siftr_pkt_queue_mtx);
979 if (inp_locally_locked)
983 /* Returning 0 ensures pfil will not discard the pkt */
990 siftr_chkpkt6(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
997 struct siftr_stats *ss;
999 int inp_locally_locked;
1001 inp_locally_locked = 0;
1005 * m_pullup is not required here because ip6_{input|output}
1006 * already do the heavy lifting for us.
1009 ip6 = mtod(*m, struct ip6_hdr *);
1012 * Only continue processing if the packet is TCP
1013 * XXX: We should follow the next header fields
1014 * as shown on Pg 6 RFC 2460, but right now we'll
1015 * only check pkts that have no extension headers.
1017 if (ip6->ip6_nxt != IPPROTO_TCP)
1021 * If a kernel subsystem reinjects packets into the stack, our pfil
1022 * hook will be called multiple times for the same packet.
1023 * Make sure we only process unique packets.
1025 if (siftr_chkreinject(*m, dir, ss))
1033 ip6_hl = sizeof(struct ip6_hdr);
1036 * Create a tcphdr struct starting at the correct offset
1037 * in the ipv6 packet. ip->ip_hl gives the ip header length
1038 * in 4-byte words, so multiply it to get the size in bytes.
1040 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl);
1043 * For inbound packets, the pfil hooks don't provide a pointer to the
1044 * inpcb, so we need to find it ourselves and lock it.
1047 /* Find the corresponding inpcb for this pkt. */
1048 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m,
1049 th->th_sport, th->th_dport, dir, ss);
1054 inp_locally_locked = 1;
1057 /* Find the TCP control block that corresponds with this packet. */
1058 tp = intotcpcb(inp);
1061 * If we can't find the TCP control block (happens occasionaly for a
1062 * packet sent during the shutdown phase of a TCP connection),
1063 * or we're in the timewait state, bail.
1065 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
1067 ss->nskip_in_tcpcb++;
1069 ss->nskip_out_tcpcb++;
1074 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
1078 ss->nskip_in_malloc++;
1080 ss->nskip_out_malloc++;
1085 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked);
1087 /* XXX: Figure out how to generate hashes for IPv6 packets. */
1089 mtx_lock(&siftr_pkt_queue_mtx);
1090 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
1091 mtx_unlock(&siftr_pkt_queue_mtx);
1095 if (inp_locally_locked)
1099 /* Returning 0 ensures pfil will not discard the pkt. */
1102 #endif /* #ifdef SIFTR_IPV6 */
1106 siftr_pfil(int action)
1108 struct pfil_head *pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
1110 struct pfil_head *pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
1113 if (action == HOOK) {
1114 pfil_add_hook(siftr_chkpkt, NULL,
1115 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet);
1117 pfil_add_hook(siftr_chkpkt6, NULL,
1118 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6);
1120 } else if (action == UNHOOK) {
1121 pfil_remove_hook(siftr_chkpkt, NULL,
1122 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet);
1124 pfil_remove_hook(siftr_chkpkt6, NULL,
1125 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6);
1134 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS)
1136 struct alq *new_alq;
1139 if (req->newptr == NULL)
1142 /* If old filename and new filename are different. */
1143 if (strncmp(siftr_logfile, (char *)req->newptr, PATH_MAX)) {
1145 error = alq_open(&new_alq, req->newptr, curthread->td_ucred,
1146 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1148 /* Bail if unable to create new alq. */
1153 * If disabled, siftr_alq == NULL so we simply close
1154 * the alq as we've proved it can be opened.
1155 * If enabled, close the existing alq and switch the old
1158 if (siftr_alq == NULL)
1161 alq_close(siftr_alq);
1162 siftr_alq = new_alq;
1167 return (sysctl_handle_string(oidp, arg1, arg2, req));
1172 siftr_manage_ops(uint8_t action)
1174 struct siftr_stats totalss;
1175 struct timeval tval;
1176 struct flow_hash_node *counter, *tmp_counter;
1178 int i, key_index, ret, error;
1179 uint32_t bytes_to_write, total_skipped_pkts;
1180 uint16_t lport, fport;
1181 uint8_t *key, ipver;
1192 total_skipped_pkts = 0;
1194 /* Init an autosizing sbuf that initially holds 200 chars. */
1195 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL)
1198 if (action == SIFTR_ENABLE) {
1201 * XXX: We should abort if alq_open fails!
1203 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred,
1204 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1206 STAILQ_INIT(&pkt_queue);
1210 siftr_exit_pkt_manager_thread = 0;
1212 ret = kthread_add(&siftr_pkt_manager_thread, NULL, NULL,
1213 &siftr_pkt_manager_thr, RFNOWAIT, 0,
1214 "siftr_pkt_manager_thr");
1221 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t"
1222 "siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t"
1223 "sysver=%u\tipmode=%u\n",
1224 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz,
1225 TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE);
1228 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK);
1230 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) {
1232 * Remove the pfil hook functions. All threads currently in
1233 * the hook functions are allowed to exit before siftr_pfil()
1238 /* This will block until the pkt manager thread unlocks it. */
1239 mtx_lock(&siftr_pkt_mgr_mtx);
1241 /* Tell the pkt manager thread that it should exit now. */
1242 siftr_exit_pkt_manager_thread = 1;
1245 * Wake the pkt_manager thread so it realises that
1246 * siftr_exit_pkt_manager_thread == 1 and exits gracefully.
1247 * The wakeup won't be delivered until we unlock
1248 * siftr_pkt_mgr_mtx so this isn't racy.
1250 wakeup(&wait_for_pkt);
1252 /* Wait for the pkt_manager thread to exit. */
1253 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT,
1256 siftr_pkt_manager_thr = NULL;
1257 mtx_unlock(&siftr_pkt_mgr_mtx);
1259 totalss.n_in = DPCPU_VARSUM(ss, n_in);
1260 totalss.n_out = DPCPU_VARSUM(ss, n_out);
1261 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc);
1262 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc);
1263 totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx);
1264 totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx);
1265 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb);
1266 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb);
1267 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb);
1268 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb);
1270 total_skipped_pkts = totalss.nskip_in_malloc +
1271 totalss.nskip_out_malloc + totalss.nskip_in_mtx +
1272 totalss.nskip_out_mtx + totalss.nskip_in_tcpcb +
1273 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb +
1274 totalss.nskip_out_inpcb;
1279 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t"
1280 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t"
1281 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t"
1282 "num_outbound_skipped_pkts_malloc=%u\t"
1283 "num_inbound_skipped_pkts_mtx=%u\t"
1284 "num_outbound_skipped_pkts_mtx=%u\t"
1285 "num_inbound_skipped_pkts_tcpcb=%u\t"
1286 "num_outbound_skipped_pkts_tcpcb=%u\t"
1287 "num_inbound_skipped_pkts_inpcb=%u\t"
1288 "num_outbound_skipped_pkts_inpcb=%u\t"
1289 "total_skipped_tcp_pkts=%u\tflow_list=",
1290 (intmax_t)tval.tv_sec,
1292 (uintmax_t)totalss.n_in,
1293 (uintmax_t)totalss.n_out,
1294 (uintmax_t)(totalss.n_in + totalss.n_out),
1295 totalss.nskip_in_malloc,
1296 totalss.nskip_out_malloc,
1297 totalss.nskip_in_mtx,
1298 totalss.nskip_out_mtx,
1299 totalss.nskip_in_tcpcb,
1300 totalss.nskip_out_tcpcb,
1301 totalss.nskip_in_inpcb,
1302 totalss.nskip_out_inpcb,
1303 total_skipped_pkts);
1306 * Iterate over the flow hash, printing a summary of each
1307 * flow seen and freeing any malloc'd memory.
1308 * The hash consists of an array of LISTs (man 3 queue).
1310 for (i = 0; i < siftr_hashmask; i++) {
1311 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes,
1318 memcpy(laddr, key + key_index, sizeof(laddr));
1319 key_index += sizeof(laddr);
1320 memcpy(&lport, key + key_index, sizeof(lport));
1321 key_index += sizeof(lport);
1322 memcpy(faddr, key + key_index, sizeof(faddr));
1323 key_index += sizeof(faddr);
1324 memcpy(&fport, key + key_index, sizeof(fport));
1327 laddr[3] = ntohl(laddr[3]);
1328 faddr[3] = ntohl(faddr[3]);
1330 if (ipver == INP_IPV6) {
1331 laddr[0] = ntohl(laddr[0]);
1332 laddr[1] = ntohl(laddr[1]);
1333 laddr[2] = ntohl(laddr[2]);
1334 faddr[0] = ntohl(faddr[0]);
1335 faddr[1] = ntohl(faddr[1]);
1336 faddr[2] = ntohl(faddr[2]);
1339 "%x:%x:%x:%x:%x:%x:%x:%x;%u-"
1340 "%x:%x:%x:%x:%x:%x:%x:%x;%u,",
1341 UPPER_SHORT(laddr[0]),
1342 LOWER_SHORT(laddr[0]),
1343 UPPER_SHORT(laddr[1]),
1344 LOWER_SHORT(laddr[1]),
1345 UPPER_SHORT(laddr[2]),
1346 LOWER_SHORT(laddr[2]),
1347 UPPER_SHORT(laddr[3]),
1348 LOWER_SHORT(laddr[3]),
1350 UPPER_SHORT(faddr[0]),
1351 LOWER_SHORT(faddr[0]),
1352 UPPER_SHORT(faddr[1]),
1353 LOWER_SHORT(faddr[1]),
1354 UPPER_SHORT(faddr[2]),
1355 LOWER_SHORT(faddr[2]),
1356 UPPER_SHORT(faddr[3]),
1357 LOWER_SHORT(faddr[3]),
1360 laddr[0] = FIRST_OCTET(laddr[3]);
1361 laddr[1] = SECOND_OCTET(laddr[3]);
1362 laddr[2] = THIRD_OCTET(laddr[3]);
1363 laddr[3] = FOURTH_OCTET(laddr[3]);
1364 faddr[0] = FIRST_OCTET(faddr[3]);
1365 faddr[1] = SECOND_OCTET(faddr[3]);
1366 faddr[2] = THIRD_OCTET(faddr[3]);
1367 faddr[3] = FOURTH_OCTET(faddr[3]);
1370 "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,",
1385 free(counter, M_SIFTR_HASHNODE);
1388 LIST_INIT(counter_hash + i);
1391 sbuf_printf(s, "\n");
1396 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i);
1397 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK);
1398 i += bytes_to_write;
1399 } while (i < sbuf_len(s));
1401 alq_close(siftr_alq);
1408 * XXX: Should be using ret to check if any functions fail
1409 * and set error appropriately
1417 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS)
1419 if (req->newptr == NULL)
1422 /* If the value passed in isn't 0 or 1, return an error. */
1423 if (CAST_PTR_INT(req->newptr) != 0 && CAST_PTR_INT(req->newptr) != 1)
1426 /* If we are changing state (0 to 1 or 1 to 0). */
1427 if (CAST_PTR_INT(req->newptr) != siftr_enabled )
1428 if (siftr_manage_ops(CAST_PTR_INT(req->newptr))) {
1429 siftr_manage_ops(SIFTR_DISABLE);
1434 return (sysctl_handle_int(oidp, arg1, arg2, req));
1439 siftr_shutdown_handler(void *arg)
1441 siftr_manage_ops(SIFTR_DISABLE);
1446 * Module is being unloaded or machine is shutting down. Take care of cleanup.
1452 siftr_manage_ops(SIFTR_DISABLE);
1453 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask);
1454 mtx_destroy(&siftr_pkt_queue_mtx);
1455 mtx_destroy(&siftr_pkt_mgr_mtx);
1462 * Module has just been loaded into the kernel.
1467 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL,
1468 SHUTDOWN_PRI_FIRST);
1470 /* Initialise our flow counter hash table. */
1471 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR,
1474 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF);
1475 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF);
1477 /* Print message to the user's current terminal. */
1478 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n"
1479 " http://caia.swin.edu.au/urp/newtcp\n\n",
1487 * This is the function that is called to load and unload the module.
1488 * When the module is loaded, this function is called once with
1489 * "what" == MOD_LOAD
1490 * When the module is unloaded, this function is called twice with
1491 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second
1492 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command,
1493 * this function is called once with "what" = MOD_SHUTDOWN
1494 * When the system is shut down, the handler isn't called until the very end
1495 * of the shutdown sequence i.e. after the disks have been synced.
1498 siftr_load_handler(module_t mod, int what, void *arg)
1509 ret = deinit_siftr();
1525 static moduledata_t siftr_mod = {
1527 .evhand = siftr_load_handler,
1531 * Param 1: name of the kernel module
1532 * Param 2: moduledata_t struct containing info about the kernel module
1533 * and the execution entry point for the module
1534 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h
1535 * Defines the module initialisation order
1536 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h
1537 * Defines the initialisation order of this kld relative to others
1538 * within the same subsystem as defined by param 3
1540 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_SMP, SI_ORDER_ANY);
1541 MODULE_DEPEND(siftr, alq, 1, 1, 1);
1542 MODULE_VERSION(siftr, MODVERSION);