2 * Copyright (c) 2007-2009
3 * Swinburne University of Technology, Melbourne, Australia.
4 * Copyright (c) 2009-2010, The FreeBSD Foundation
7 * Portions of this software were developed at the Centre for Advanced
8 * Internet Architectures, Swinburne University of Technology, Melbourne,
9 * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 /******************************************************
34 * Statistical Information For TCP Research (SIFTR)
36 * A FreeBSD kernel module that adds very basic intrumentation to the
37 * TCP stack, allowing internal stats to be recorded to a log file
38 * for experimental, debugging and performance analysis purposes.
40 * SIFTR was first released in 2007 by James Healy and Lawrence Stewart whilst
41 * working on the NewTCP research project at Swinburne University of
42 * Technology's Centre for Advanced Internet Architectures, Melbourne,
43 * Australia, which was made possible in part by a grant from the Cisco
44 * University Research Program Fund at Community Foundation Silicon Valley.
45 * 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: September 2010
59 ******************************************************/
61 #include <sys/cdefs.h>
62 __FBSDID("$FreeBSD$");
64 #include <sys/param.h>
66 #include <sys/errno.h>
67 #include <sys/eventhandler.h>
69 #include <sys/kernel.h>
70 #include <sys/kthread.h>
73 #include <sys/module.h>
74 #include <sys/mutex.h>
80 #include <sys/socket.h>
81 #include <sys/socketvar.h>
82 #include <sys/sysctl.h>
83 #include <sys/unistd.h>
86 #include <net/if_var.h>
89 #include <netinet/in.h>
90 #include <netinet/in_kdtrace.h>
91 #include <netinet/in_pcb.h>
92 #include <netinet/in_systm.h>
93 #include <netinet/in_var.h>
94 #include <netinet/ip.h>
95 #include <netinet/tcp_var.h>
98 #include <netinet/ip6.h>
99 #include <netinet6/in6_pcb.h>
100 #endif /* SIFTR_IPV6 */
102 #include <machine/in_cksum.h>
105 * Three digit version number refers to X.Y.Z where:
106 * X is the major version number
107 * Y is bumped to mark backwards incompatible changes
108 * Z is bumped to mark backwards compatible changes
111 #define V_BACKBREAK 2
112 #define V_BACKCOMPAT 4
113 #define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT))
114 #define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \
115 __XSTRING(V_BACKCOMPAT)
119 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536
120 #define SYS_NAME "FreeBSD"
121 #define PACKET_TAG_SIFTR 100
122 #define PACKET_COOKIE_SIFTR 21749576
123 #define SIFTR_LOG_FILE_MODE 0644
124 #define SIFTR_DISABLE 0
125 #define SIFTR_ENABLE 1
128 * Hard upper limit on the length of log messages. Bump this up if you add new
129 * data fields such that the line length could exceed the below value.
131 #define MAX_LOG_MSG_LEN 200
132 /* XXX: Make this a sysctl tunable. */
133 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN)
136 * 1 byte for IP version
137 * IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes
138 * IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes
141 #define FLOW_KEY_LEN 37
143 #define FLOW_KEY_LEN 13
147 #define SIFTR_IPMODE 6
149 #define SIFTR_IPMODE 4
153 #define CAST_PTR_INT(X) (*((int*)(X)))
155 #define UPPER_SHORT(X) (((X) & 0xFFFF0000) >> 16)
156 #define LOWER_SHORT(X) ((X) & 0x0000FFFF)
158 #define FIRST_OCTET(X) (((X) & 0xFF000000) >> 24)
159 #define SECOND_OCTET(X) (((X) & 0x00FF0000) >> 16)
160 #define THIRD_OCTET(X) (((X) & 0x0000FF00) >> 8)
161 #define FOURTH_OCTET(X) ((X) & 0x000000FF)
163 static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR");
164 static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode",
165 "SIFTR pkt_node struct");
166 static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode",
167 "SIFTR flow_hash_node struct");
169 /* Used as links in the pkt manager queue. */
171 /* Timestamp of pkt as noted in the pfil hook. */
173 /* Direction pkt is travelling; either PFIL_IN or PFIL_OUT. */
175 /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */
177 /* Hash of the pkt which triggered the log message. */
179 /* Local/foreign IP address. */
181 uint32_t ip_laddr[4];
182 uint32_t ip_faddr[4];
187 /* Local TCP port. */
188 uint16_t tcp_localport;
189 /* Foreign TCP port. */
190 uint16_t tcp_foreignport;
191 /* Congestion Window (bytes). */
193 /* Sending Window (bytes). */
195 /* Receive Window (bytes). */
197 /* Unused (was: Bandwidth Controlled Window (bytes)). */
199 /* Slow Start Threshold (bytes). */
201 /* Current state of the TCP FSM. */
203 /* Max Segment Size (bytes). */
206 * Smoothed RTT stored as found in the TCP control block
207 * in units of (TCP_RTT_SCALE*hz).
210 /* Is SACK enabled? */
212 /* Window scaling for snd window. */
214 /* Window scaling for recv window. */
216 /* TCP control block flags. */
218 /* Retransmit timeout length. */
220 /* Size of the TCP send buffer in bytes. */
221 u_int snd_buf_hiwater;
222 /* Current num bytes in the send socket buffer. */
224 /* Size of the TCP receive buffer in bytes. */
225 u_int rcv_buf_hiwater;
226 /* Current num bytes in the receive socket buffer. */
228 /* Number of bytes inflight that we are waiting on ACKs for. */
229 u_int sent_inflight_bytes;
230 /* Number of segments currently in the reassembly queue. */
232 /* Flowid for the connection. */
234 /* Flow type for the connection. */
236 /* Link to next pkt_node in the list. */
237 STAILQ_ENTRY(pkt_node) nodes;
240 struct flow_hash_node
243 uint8_t key[FLOW_KEY_LEN];
244 LIST_ENTRY(flow_hash_node) nodes;
249 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */
252 /* # pkts skipped due to failed malloc calls. */
253 uint32_t nskip_in_malloc;
254 uint32_t nskip_out_malloc;
255 /* # pkts skipped due to failed mtx acquisition. */
256 uint32_t nskip_in_mtx;
257 uint32_t nskip_out_mtx;
258 /* # pkts skipped due to failed inpcb lookups. */
259 uint32_t nskip_in_inpcb;
260 uint32_t nskip_out_inpcb;
261 /* # pkts skipped due to failed tcpcb lookups. */
262 uint32_t nskip_in_tcpcb;
263 uint32_t nskip_out_tcpcb;
264 /* # pkts skipped due to stack reinjection. */
265 uint32_t nskip_in_dejavu;
266 uint32_t nskip_out_dejavu;
269 static DPCPU_DEFINE(struct siftr_stats, ss);
271 static volatile unsigned int siftr_exit_pkt_manager_thread = 0;
272 static unsigned int siftr_enabled = 0;
273 static unsigned int siftr_pkts_per_log = 1;
274 static unsigned int siftr_generate_hashes = 0;
275 /* static unsigned int siftr_binary_log = 0; */
276 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log";
277 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log";
278 static u_long siftr_hashmask;
279 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue);
280 LIST_HEAD(listhead, flow_hash_node) *counter_hash;
281 static int wait_for_pkt;
282 static struct alq *siftr_alq = NULL;
283 static struct mtx siftr_pkt_queue_mtx;
284 static struct mtx siftr_pkt_mgr_mtx;
285 static struct thread *siftr_pkt_manager_thr = NULL;
287 * pfil.h defines PFIL_IN as 1 and PFIL_OUT as 2,
288 * which we use as an index into this array.
290 static char direction[3] = {'\0', 'i','o'};
292 /* Required function prototypes. */
293 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS);
294 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS);
297 /* Declare the net.inet.siftr sysctl tree and populate it. */
299 SYSCTL_DECL(_net_inet_siftr);
301 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW, NULL,
302 "siftr related settings");
304 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, CTLTYPE_UINT|CTLFLAG_RW,
305 &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU",
306 "switch siftr module operations on/off");
308 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, CTLTYPE_STRING|CTLFLAG_RW,
309 &siftr_logfile_shadow, sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler,
310 "A", "file to save siftr log messages to");
312 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW,
313 &siftr_pkts_per_log, 1,
314 "number of packets between generating a log message");
316 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW,
317 &siftr_generate_hashes, 0,
318 "enable packet hash generation");
321 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW,
322 &siftr_binary_log, 0,
323 "write log files in binary instead of ascii");
327 /* Begin functions. */
330 siftr_process_pkt(struct pkt_node * pkt_node)
332 struct flow_hash_node *hash_node;
333 struct listhead *counter_list;
334 struct siftr_stats *ss;
336 uint8_t key[FLOW_KEY_LEN];
337 uint8_t found_match, key_offset;
345 * Create the key that will be used to create a hash index
346 * into our hash table. Our key consists of:
347 * ipversion, localip, localport, foreignip, foreignport
349 key[0] = pkt_node->ipver;
350 memcpy(key + key_offset, &pkt_node->ip_laddr,
351 sizeof(pkt_node->ip_laddr));
352 key_offset += sizeof(pkt_node->ip_laddr);
353 memcpy(key + key_offset, &pkt_node->tcp_localport,
354 sizeof(pkt_node->tcp_localport));
355 key_offset += sizeof(pkt_node->tcp_localport);
356 memcpy(key + key_offset, &pkt_node->ip_faddr,
357 sizeof(pkt_node->ip_faddr));
358 key_offset += sizeof(pkt_node->ip_faddr);
359 memcpy(key + key_offset, &pkt_node->tcp_foreignport,
360 sizeof(pkt_node->tcp_foreignport));
362 counter_list = counter_hash +
363 (hash32_buf(key, sizeof(key), 0) & siftr_hashmask);
366 * If the list is not empty i.e. the hash index has
367 * been used by another flow previously.
369 if (LIST_FIRST(counter_list) != NULL) {
371 * Loop through the hash nodes in the list.
372 * There should normally only be 1 hash node in the list,
373 * except if there have been collisions at the hash index
374 * computed by hash32_buf().
376 LIST_FOREACH(hash_node, counter_list, nodes) {
378 * Check if the key for the pkt we are currently
379 * processing is the same as the key stored in the
380 * hash node we are currently processing.
381 * If they are the same, then we've found the
382 * hash node that stores the counter for the flow
383 * the pkt belongs to.
385 if (memcmp(hash_node->key, key, sizeof(key)) == 0) {
392 /* If this flow hash hasn't been seen before or we have a collision. */
393 if (hash_node == NULL || !found_match) {
394 /* Create a new hash node to store the flow's counter. */
395 hash_node = malloc(sizeof(struct flow_hash_node),
396 M_SIFTR_HASHNODE, M_WAITOK);
398 if (hash_node != NULL) {
399 /* Initialise our new hash node list entry. */
400 hash_node->counter = 0;
401 memcpy(hash_node->key, key, sizeof(key));
402 LIST_INSERT_HEAD(counter_list, hash_node, nodes);
405 if (pkt_node->direction == PFIL_IN)
406 ss->nskip_in_malloc++;
408 ss->nskip_out_malloc++;
412 } else if (siftr_pkts_per_log > 1) {
414 * Taking the remainder of the counter divided
415 * by the current value of siftr_pkts_per_log
416 * and storing that in counter provides a neat
417 * way to modulate the frequency of log
418 * messages being written to the log file.
420 hash_node->counter = (hash_node->counter + 1) %
424 * If we have not seen enough packets since the last time
425 * we wrote a log message for this connection, return.
427 if (hash_node->counter > 0)
431 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK);
434 return; /* Should only happen if the ALQ is shutting down. */
437 pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]);
438 pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]);
440 if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */
441 pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]);
442 pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]);
443 pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]);
444 pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]);
445 pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]);
446 pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]);
448 /* Construct an IPv6 log message. */
449 log_buf->ae_bytesused = snprintf(log_buf->ae_data,
451 "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:"
452 "%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,"
453 "%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n",
454 direction[pkt_node->direction],
456 pkt_node->tval.tv_sec,
457 pkt_node->tval.tv_usec,
458 UPPER_SHORT(pkt_node->ip_laddr[0]),
459 LOWER_SHORT(pkt_node->ip_laddr[0]),
460 UPPER_SHORT(pkt_node->ip_laddr[1]),
461 LOWER_SHORT(pkt_node->ip_laddr[1]),
462 UPPER_SHORT(pkt_node->ip_laddr[2]),
463 LOWER_SHORT(pkt_node->ip_laddr[2]),
464 UPPER_SHORT(pkt_node->ip_laddr[3]),
465 LOWER_SHORT(pkt_node->ip_laddr[3]),
466 ntohs(pkt_node->tcp_localport),
467 UPPER_SHORT(pkt_node->ip_faddr[0]),
468 LOWER_SHORT(pkt_node->ip_faddr[0]),
469 UPPER_SHORT(pkt_node->ip_faddr[1]),
470 LOWER_SHORT(pkt_node->ip_faddr[1]),
471 UPPER_SHORT(pkt_node->ip_faddr[2]),
472 LOWER_SHORT(pkt_node->ip_faddr[2]),
473 UPPER_SHORT(pkt_node->ip_faddr[3]),
474 LOWER_SHORT(pkt_node->ip_faddr[3]),
475 ntohs(pkt_node->tcp_foreignport),
476 pkt_node->snd_ssthresh,
483 pkt_node->conn_state,
484 pkt_node->max_seg_size,
485 pkt_node->smoothed_rtt,
486 pkt_node->sack_enabled,
488 pkt_node->rxt_length,
489 pkt_node->snd_buf_hiwater,
490 pkt_node->snd_buf_cc,
491 pkt_node->rcv_buf_hiwater,
492 pkt_node->rcv_buf_cc,
493 pkt_node->sent_inflight_bytes,
497 } else { /* IPv4 packet */
498 pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]);
499 pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]);
500 pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]);
501 pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]);
502 pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]);
503 pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]);
504 pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]);
505 pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]);
506 #endif /* SIFTR_IPV6 */
508 /* Construct an IPv4 log message. */
509 log_buf->ae_bytesused = snprintf(log_buf->ae_data,
511 "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld,"
512 "%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n",
513 direction[pkt_node->direction],
515 (intmax_t)pkt_node->tval.tv_sec,
516 pkt_node->tval.tv_usec,
517 pkt_node->ip_laddr[0],
518 pkt_node->ip_laddr[1],
519 pkt_node->ip_laddr[2],
520 pkt_node->ip_laddr[3],
521 ntohs(pkt_node->tcp_localport),
522 pkt_node->ip_faddr[0],
523 pkt_node->ip_faddr[1],
524 pkt_node->ip_faddr[2],
525 pkt_node->ip_faddr[3],
526 ntohs(pkt_node->tcp_foreignport),
527 pkt_node->snd_ssthresh,
534 pkt_node->conn_state,
535 pkt_node->max_seg_size,
536 pkt_node->smoothed_rtt,
537 pkt_node->sack_enabled,
539 pkt_node->rxt_length,
540 pkt_node->snd_buf_hiwater,
541 pkt_node->snd_buf_cc,
542 pkt_node->rcv_buf_hiwater,
543 pkt_node->rcv_buf_cc,
544 pkt_node->sent_inflight_bytes,
552 alq_post_flags(siftr_alq, log_buf, 0);
557 siftr_pkt_manager_thread(void *arg)
559 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue =
560 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue);
561 struct pkt_node *pkt_node, *pkt_node_temp;
566 mtx_lock(&siftr_pkt_mgr_mtx);
568 /* draining == 0 when queue has been flushed and it's safe to exit. */
571 * Sleep until we are signalled to wake because thread has
572 * been told to exit or until 1 tick has passed.
574 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait",
577 /* Gain exclusive access to the pkt_node queue. */
578 mtx_lock(&siftr_pkt_queue_mtx);
581 * Move pkt_queue to tmp_pkt_queue, which leaves
582 * pkt_queue empty and ready to receive more pkt_nodes.
584 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue);
587 * We've finished making changes to the list. Unlock it
588 * so the pfil hooks can continue queuing pkt_nodes.
590 mtx_unlock(&siftr_pkt_queue_mtx);
593 * We can't hold a mutex whilst calling siftr_process_pkt
594 * because ALQ might sleep waiting for buffer space.
596 mtx_unlock(&siftr_pkt_mgr_mtx);
598 /* Flush all pkt_nodes to the log file. */
599 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes,
601 siftr_process_pkt(pkt_node);
602 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes);
603 free(pkt_node, M_SIFTR_PKTNODE);
606 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue),
607 ("SIFTR tmp_pkt_queue not empty after flush"));
609 mtx_lock(&siftr_pkt_mgr_mtx);
612 * If siftr_exit_pkt_manager_thread gets set during the window
613 * where we are draining the tmp_pkt_queue above, there might
614 * still be pkts in pkt_queue that need to be drained.
615 * Allow one further iteration to occur after
616 * siftr_exit_pkt_manager_thread has been set to ensure
617 * pkt_queue is completely empty before we kill the thread.
619 * siftr_exit_pkt_manager_thread is set only after the pfil
620 * hooks have been removed, so only 1 extra iteration
621 * is needed to drain the queue.
623 if (siftr_exit_pkt_manager_thread)
627 mtx_unlock(&siftr_pkt_mgr_mtx);
629 /* Calls wakeup on this thread's struct thread ptr. */
635 hash_pkt(struct mbuf *m, uint32_t offset)
641 while (m != NULL && offset > m->m_len) {
643 * The IP packet payload does not start in this mbuf, so
644 * need to figure out which mbuf it starts in and what offset
645 * into the mbuf's data region the payload starts at.
652 /* Ensure there is data in the mbuf */
653 if ((m->m_len - offset) > 0)
654 hash = hash32_buf(m->m_data + offset,
655 m->m_len - offset, hash);
666 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that
667 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return.
668 * Return value >0 means the caller should skip processing this mbuf.
671 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss)
673 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL)
676 ss->nskip_in_dejavu++;
678 ss->nskip_out_dejavu++;
682 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR,
683 PACKET_TAG_SIFTR, 0, M_NOWAIT);
686 ss->nskip_in_malloc++;
688 ss->nskip_out_malloc++;
693 m_tag_prepend(m, tag);
701 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL
704 static inline struct inpcb *
705 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport,
706 uint16_t dport, int dir, struct siftr_stats *ss)
710 /* We need the tcbinfo lock. */
711 INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
714 inp = (ipver == INP_IPV4 ?
715 in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst,
716 dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
719 in6_pcblookup(&V_tcbinfo,
720 &((struct ip6_hdr *)ip)->ip6_src, sport,
721 &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB,
729 inp = (ipver == INP_IPV4 ?
730 in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src,
731 sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
734 in6_pcblookup(&V_tcbinfo,
735 &((struct ip6_hdr *)ip)->ip6_dst, dport,
736 &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB,
743 /* If we can't find the inpcb, bail. */
746 ss->nskip_in_inpcb++;
748 ss->nskip_out_inpcb++;
756 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp,
757 int ipver, int dir, int inp_locally_locked)
760 if (ipver == INP_IPV4) {
761 pn->ip_laddr[3] = inp->inp_laddr.s_addr;
762 pn->ip_faddr[3] = inp->inp_faddr.s_addr;
764 *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr;
765 *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr;
769 pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0];
770 pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1];
771 pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2];
772 pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3];
773 pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0];
774 pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1];
775 pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2];
776 pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3];
779 pn->tcp_localport = inp->inp_lport;
780 pn->tcp_foreignport = inp->inp_fport;
781 pn->snd_cwnd = tp->snd_cwnd;
782 pn->snd_wnd = tp->snd_wnd;
783 pn->rcv_wnd = tp->rcv_wnd;
784 pn->snd_bwnd = 0; /* Unused, kept for compat. */
785 pn->snd_ssthresh = tp->snd_ssthresh;
786 pn->snd_scale = tp->snd_scale;
787 pn->rcv_scale = tp->rcv_scale;
788 pn->conn_state = tp->t_state;
789 pn->max_seg_size = tp->t_maxseg;
790 pn->smoothed_rtt = tp->t_srtt;
791 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0;
792 pn->flags = tp->t_flags;
793 pn->rxt_length = tp->t_rxtcur;
794 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat;
795 pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd);
796 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat;
797 pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv);
798 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una;
799 pn->t_segqlen = tp->t_segqlen;
800 pn->flowid = inp->inp_flowid;
801 pn->flowtype = inp->inp_flowtype;
803 /* We've finished accessing the tcb so release the lock. */
804 if (inp_locally_locked)
811 * Significantly more accurate than using getmicrotime(), but slower!
812 * Gives true microsecond resolution at the expense of a hit to
813 * maximum pps throughput processing when SIFTR is loaded and enabled.
815 microtime(&pn->tval);
816 TCP_PROBE1(siftr, &pn);
822 * pfil hook that is called for each IPv4 packet making its way through the
823 * stack in either direction.
824 * The pfil subsystem holds a non-sleepable mutex somewhere when
825 * calling our hook function, so we can't sleep at all.
826 * It's very important to use the M_NOWAIT flag with all function calls
827 * that support it so that they won't sleep, otherwise you get a panic.
830 siftr_chkpkt(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
837 struct siftr_stats *ss;
839 int inp_locally_locked;
841 inp_locally_locked = 0;
845 * m_pullup is not required here because ip_{input|output}
846 * already do the heavy lifting for us.
849 ip = mtod(*m, struct ip *);
851 /* Only continue processing if the packet is TCP. */
852 if (ip->ip_p != IPPROTO_TCP)
856 * If a kernel subsystem reinjects packets into the stack, our pfil
857 * hook will be called multiple times for the same packet.
858 * Make sure we only process unique packets.
860 if (siftr_chkreinject(*m, dir, ss))
869 * Create a tcphdr struct starting at the correct offset
870 * in the IP packet. ip->ip_hl gives the ip header length
871 * in 4-byte words, so multiply it to get the size in bytes.
873 ip_hl = (ip->ip_hl << 2);
874 th = (struct tcphdr *)((caddr_t)ip + ip_hl);
877 * If the pfil hooks don't provide a pointer to the
878 * inpcb, we need to find it ourselves and lock it.
881 /* Find the corresponding inpcb for this pkt. */
882 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport,
883 th->th_dport, dir, ss);
888 inp_locally_locked = 1;
891 INP_LOCK_ASSERT(inp);
893 /* Find the TCP control block that corresponds with this packet */
897 * If we can't find the TCP control block (happens occasionaly for a
898 * packet sent during the shutdown phase of a TCP connection),
899 * or we're in the timewait state, bail
901 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
903 ss->nskip_in_tcpcb++;
905 ss->nskip_out_tcpcb++;
910 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
914 ss->nskip_in_malloc++;
916 ss->nskip_out_malloc++;
921 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked);
923 if (siftr_generate_hashes) {
924 if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) {
926 * For outbound packets, the TCP checksum isn't
927 * calculated yet. This is a problem for our packet
928 * hashing as the receiver will calc a different hash
929 * to ours if we don't include the correct TCP checksum
930 * in the bytes being hashed. To work around this
931 * problem, we manually calc the TCP checksum here in
932 * software. We unset the CSUM_TCP flag so the lower
933 * layers don't recalc it.
935 (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP;
938 * Calculate the TCP checksum in software and assign
939 * to correct TCP header field, which will follow the
940 * packet mbuf down the stack. The trick here is that
941 * tcp_output() sets th->th_sum to the checksum of the
942 * pseudo header for us already. Because of the nature
943 * of the checksumming algorithm, we can sum over the
944 * entire IP payload (i.e. TCP header and data), which
945 * will include the already calculated pseduo header
946 * checksum, thus giving us the complete TCP checksum.
948 * To put it in simple terms, if checksum(1,2,3,4)=10,
949 * then checksum(1,2,3,4,5) == checksum(10,5).
950 * This property is what allows us to "cheat" and
951 * checksum only the IP payload which has the TCP
952 * th_sum field populated with the pseudo header's
953 * checksum, and not need to futz around checksumming
954 * pseudo header bytes and TCP header/data in one hit.
955 * Refer to RFC 1071 for more info.
957 * NB: in_cksum_skip(struct mbuf *m, int len, int skip)
958 * in_cksum_skip 2nd argument is NOT the number of
959 * bytes to read from the mbuf at "skip" bytes offset
960 * from the start of the mbuf (very counter intuitive!).
961 * The number of bytes to read is calculated internally
962 * by the function as len-skip i.e. to sum over the IP
963 * payload (TCP header + data) bytes, it is INCORRECT
964 * to call the function like this:
965 * in_cksum_skip(at, ip->ip_len - offset, offset)
966 * Rather, it should be called like this:
967 * in_cksum_skip(at, ip->ip_len, offset)
968 * which means read "ip->ip_len - offset" bytes from
969 * the mbuf cluster "at" at offset "offset" bytes from
970 * the beginning of the "at" mbuf's data pointer.
972 th->th_sum = in_cksum_skip(*m, ntohs(ip->ip_len),
977 * XXX: Having to calculate the checksum in software and then
978 * hash over all bytes is really inefficient. Would be nice to
979 * find a way to create the hash and checksum in the same pass
982 pn->hash = hash_pkt(*m, ip_hl);
985 mtx_lock(&siftr_pkt_queue_mtx);
986 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
987 mtx_unlock(&siftr_pkt_queue_mtx);
991 if (inp_locally_locked)
995 /* Returning 0 ensures pfil will not discard the pkt */
1002 siftr_chkpkt6(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
1005 struct pkt_node *pn;
1006 struct ip6_hdr *ip6;
1009 struct siftr_stats *ss;
1010 unsigned int ip6_hl;
1011 int inp_locally_locked;
1013 inp_locally_locked = 0;
1017 * m_pullup is not required here because ip6_{input|output}
1018 * already do the heavy lifting for us.
1021 ip6 = mtod(*m, struct ip6_hdr *);
1024 * Only continue processing if the packet is TCP
1025 * XXX: We should follow the next header fields
1026 * as shown on Pg 6 RFC 2460, but right now we'll
1027 * only check pkts that have no extension headers.
1029 if (ip6->ip6_nxt != IPPROTO_TCP)
1033 * If a kernel subsystem reinjects packets into the stack, our pfil
1034 * hook will be called multiple times for the same packet.
1035 * Make sure we only process unique packets.
1037 if (siftr_chkreinject(*m, dir, ss))
1045 ip6_hl = sizeof(struct ip6_hdr);
1048 * Create a tcphdr struct starting at the correct offset
1049 * in the ipv6 packet. ip->ip_hl gives the ip header length
1050 * in 4-byte words, so multiply it to get the size in bytes.
1052 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl);
1055 * For inbound packets, the pfil hooks don't provide a pointer to the
1056 * inpcb, so we need to find it ourselves and lock it.
1059 /* Find the corresponding inpcb for this pkt. */
1060 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m,
1061 th->th_sport, th->th_dport, dir, ss);
1066 inp_locally_locked = 1;
1069 /* Find the TCP control block that corresponds with this packet. */
1070 tp = intotcpcb(inp);
1073 * If we can't find the TCP control block (happens occasionaly for a
1074 * packet sent during the shutdown phase of a TCP connection),
1075 * or we're in the timewait state, bail.
1077 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
1079 ss->nskip_in_tcpcb++;
1081 ss->nskip_out_tcpcb++;
1086 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
1090 ss->nskip_in_malloc++;
1092 ss->nskip_out_malloc++;
1097 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked);
1099 /* XXX: Figure out how to generate hashes for IPv6 packets. */
1101 mtx_lock(&siftr_pkt_queue_mtx);
1102 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
1103 mtx_unlock(&siftr_pkt_queue_mtx);
1107 if (inp_locally_locked)
1111 /* Returning 0 ensures pfil will not discard the pkt. */
1114 #endif /* #ifdef SIFTR_IPV6 */
1118 siftr_pfil(int action)
1120 struct pfil_head *pfh_inet;
1122 struct pfil_head *pfh_inet6;
1124 VNET_ITERATOR_DECL(vnet_iter);
1127 VNET_FOREACH(vnet_iter) {
1128 CURVNET_SET(vnet_iter);
1129 pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
1131 pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
1134 if (action == HOOK) {
1135 pfil_add_hook(siftr_chkpkt, NULL,
1136 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet);
1138 pfil_add_hook(siftr_chkpkt6, NULL,
1139 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6);
1141 } else if (action == UNHOOK) {
1142 pfil_remove_hook(siftr_chkpkt, NULL,
1143 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet);
1145 pfil_remove_hook(siftr_chkpkt6, NULL,
1146 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6);
1151 VNET_LIST_RUNLOCK();
1158 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS)
1160 struct alq *new_alq;
1163 error = sysctl_handle_string(oidp, arg1, arg2, req);
1165 /* Check for error or same filename */
1166 if (error != 0 || req->newptr == NULL ||
1167 strncmp(siftr_logfile, arg1, arg2) == 0)
1170 /* Filname changed */
1171 error = alq_open(&new_alq, arg1, curthread->td_ucred,
1172 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1177 * If disabled, siftr_alq == NULL so we simply close
1178 * the alq as we've proved it can be opened.
1179 * If enabled, close the existing alq and switch the old
1182 if (siftr_alq == NULL) {
1185 alq_close(siftr_alq);
1186 siftr_alq = new_alq;
1189 /* Update filename upon success */
1190 strlcpy(siftr_logfile, arg1, arg2);
1196 siftr_manage_ops(uint8_t action)
1198 struct siftr_stats totalss;
1199 struct timeval tval;
1200 struct flow_hash_node *counter, *tmp_counter;
1202 int i, key_index, ret, error;
1203 uint32_t bytes_to_write, total_skipped_pkts;
1204 uint16_t lport, fport;
1205 uint8_t *key, ipver;
1216 total_skipped_pkts = 0;
1218 /* Init an autosizing sbuf that initially holds 200 chars. */
1219 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL)
1222 if (action == SIFTR_ENABLE) {
1225 * XXX: We should abort if alq_open fails!
1227 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred,
1228 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1230 STAILQ_INIT(&pkt_queue);
1234 siftr_exit_pkt_manager_thread = 0;
1236 ret = kthread_add(&siftr_pkt_manager_thread, NULL, NULL,
1237 &siftr_pkt_manager_thr, RFNOWAIT, 0,
1238 "siftr_pkt_manager_thr");
1245 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t"
1246 "siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t"
1247 "sysver=%u\tipmode=%u\n",
1248 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz,
1249 TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE);
1252 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK);
1254 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) {
1256 * Remove the pfil hook functions. All threads currently in
1257 * the hook functions are allowed to exit before siftr_pfil()
1262 /* This will block until the pkt manager thread unlocks it. */
1263 mtx_lock(&siftr_pkt_mgr_mtx);
1265 /* Tell the pkt manager thread that it should exit now. */
1266 siftr_exit_pkt_manager_thread = 1;
1269 * Wake the pkt_manager thread so it realises that
1270 * siftr_exit_pkt_manager_thread == 1 and exits gracefully.
1271 * The wakeup won't be delivered until we unlock
1272 * siftr_pkt_mgr_mtx so this isn't racy.
1274 wakeup(&wait_for_pkt);
1276 /* Wait for the pkt_manager thread to exit. */
1277 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT,
1280 siftr_pkt_manager_thr = NULL;
1281 mtx_unlock(&siftr_pkt_mgr_mtx);
1283 totalss.n_in = DPCPU_VARSUM(ss, n_in);
1284 totalss.n_out = DPCPU_VARSUM(ss, n_out);
1285 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc);
1286 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc);
1287 totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx);
1288 totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx);
1289 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb);
1290 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb);
1291 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb);
1292 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb);
1294 total_skipped_pkts = totalss.nskip_in_malloc +
1295 totalss.nskip_out_malloc + totalss.nskip_in_mtx +
1296 totalss.nskip_out_mtx + totalss.nskip_in_tcpcb +
1297 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb +
1298 totalss.nskip_out_inpcb;
1303 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t"
1304 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t"
1305 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t"
1306 "num_outbound_skipped_pkts_malloc=%u\t"
1307 "num_inbound_skipped_pkts_mtx=%u\t"
1308 "num_outbound_skipped_pkts_mtx=%u\t"
1309 "num_inbound_skipped_pkts_tcpcb=%u\t"
1310 "num_outbound_skipped_pkts_tcpcb=%u\t"
1311 "num_inbound_skipped_pkts_inpcb=%u\t"
1312 "num_outbound_skipped_pkts_inpcb=%u\t"
1313 "total_skipped_tcp_pkts=%u\tflow_list=",
1314 (intmax_t)tval.tv_sec,
1316 (uintmax_t)totalss.n_in,
1317 (uintmax_t)totalss.n_out,
1318 (uintmax_t)(totalss.n_in + totalss.n_out),
1319 totalss.nskip_in_malloc,
1320 totalss.nskip_out_malloc,
1321 totalss.nskip_in_mtx,
1322 totalss.nskip_out_mtx,
1323 totalss.nskip_in_tcpcb,
1324 totalss.nskip_out_tcpcb,
1325 totalss.nskip_in_inpcb,
1326 totalss.nskip_out_inpcb,
1327 total_skipped_pkts);
1330 * Iterate over the flow hash, printing a summary of each
1331 * flow seen and freeing any malloc'd memory.
1332 * The hash consists of an array of LISTs (man 3 queue).
1334 for (i = 0; i <= siftr_hashmask; i++) {
1335 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes,
1342 memcpy(laddr, key + key_index, sizeof(laddr));
1343 key_index += sizeof(laddr);
1344 memcpy(&lport, key + key_index, sizeof(lport));
1345 key_index += sizeof(lport);
1346 memcpy(faddr, key + key_index, sizeof(faddr));
1347 key_index += sizeof(faddr);
1348 memcpy(&fport, key + key_index, sizeof(fport));
1351 laddr[3] = ntohl(laddr[3]);
1352 faddr[3] = ntohl(faddr[3]);
1354 if (ipver == INP_IPV6) {
1355 laddr[0] = ntohl(laddr[0]);
1356 laddr[1] = ntohl(laddr[1]);
1357 laddr[2] = ntohl(laddr[2]);
1358 faddr[0] = ntohl(faddr[0]);
1359 faddr[1] = ntohl(faddr[1]);
1360 faddr[2] = ntohl(faddr[2]);
1363 "%x:%x:%x:%x:%x:%x:%x:%x;%u-"
1364 "%x:%x:%x:%x:%x:%x:%x:%x;%u,",
1365 UPPER_SHORT(laddr[0]),
1366 LOWER_SHORT(laddr[0]),
1367 UPPER_SHORT(laddr[1]),
1368 LOWER_SHORT(laddr[1]),
1369 UPPER_SHORT(laddr[2]),
1370 LOWER_SHORT(laddr[2]),
1371 UPPER_SHORT(laddr[3]),
1372 LOWER_SHORT(laddr[3]),
1374 UPPER_SHORT(faddr[0]),
1375 LOWER_SHORT(faddr[0]),
1376 UPPER_SHORT(faddr[1]),
1377 LOWER_SHORT(faddr[1]),
1378 UPPER_SHORT(faddr[2]),
1379 LOWER_SHORT(faddr[2]),
1380 UPPER_SHORT(faddr[3]),
1381 LOWER_SHORT(faddr[3]),
1384 laddr[0] = FIRST_OCTET(laddr[3]);
1385 laddr[1] = SECOND_OCTET(laddr[3]);
1386 laddr[2] = THIRD_OCTET(laddr[3]);
1387 laddr[3] = FOURTH_OCTET(laddr[3]);
1388 faddr[0] = FIRST_OCTET(faddr[3]);
1389 faddr[1] = SECOND_OCTET(faddr[3]);
1390 faddr[2] = THIRD_OCTET(faddr[3]);
1391 faddr[3] = FOURTH_OCTET(faddr[3]);
1394 "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,",
1409 free(counter, M_SIFTR_HASHNODE);
1412 LIST_INIT(counter_hash + i);
1415 sbuf_printf(s, "\n");
1420 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i);
1421 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK);
1422 i += bytes_to_write;
1423 } while (i < sbuf_len(s));
1425 alq_close(siftr_alq);
1432 * XXX: Should be using ret to check if any functions fail
1433 * and set error appropriately
1441 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS)
1443 if (req->newptr == NULL)
1446 /* If the value passed in isn't 0 or 1, return an error. */
1447 if (CAST_PTR_INT(req->newptr) != 0 && CAST_PTR_INT(req->newptr) != 1)
1450 /* If we are changing state (0 to 1 or 1 to 0). */
1451 if (CAST_PTR_INT(req->newptr) != siftr_enabled )
1452 if (siftr_manage_ops(CAST_PTR_INT(req->newptr))) {
1453 siftr_manage_ops(SIFTR_DISABLE);
1458 return (sysctl_handle_int(oidp, arg1, arg2, req));
1463 siftr_shutdown_handler(void *arg)
1465 siftr_manage_ops(SIFTR_DISABLE);
1470 * Module is being unloaded or machine is shutting down. Take care of cleanup.
1476 siftr_manage_ops(SIFTR_DISABLE);
1477 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask);
1478 mtx_destroy(&siftr_pkt_queue_mtx);
1479 mtx_destroy(&siftr_pkt_mgr_mtx);
1486 * Module has just been loaded into the kernel.
1491 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL,
1492 SHUTDOWN_PRI_FIRST);
1494 /* Initialise our flow counter hash table. */
1495 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR,
1498 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF);
1499 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF);
1501 /* Print message to the user's current terminal. */
1502 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n"
1503 " http://caia.swin.edu.au/urp/newtcp\n\n",
1511 * This is the function that is called to load and unload the module.
1512 * When the module is loaded, this function is called once with
1513 * "what" == MOD_LOAD
1514 * When the module is unloaded, this function is called twice with
1515 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second
1516 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command,
1517 * this function is called once with "what" = MOD_SHUTDOWN
1518 * When the system is shut down, the handler isn't called until the very end
1519 * of the shutdown sequence i.e. after the disks have been synced.
1522 siftr_load_handler(module_t mod, int what, void *arg)
1533 ret = deinit_siftr();
1549 static moduledata_t siftr_mod = {
1551 .evhand = siftr_load_handler,
1555 * Param 1: name of the kernel module
1556 * Param 2: moduledata_t struct containing info about the kernel module
1557 * and the execution entry point for the module
1558 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h
1559 * Defines the module initialisation order
1560 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h
1561 * Defines the initialisation order of this kld relative to others
1562 * within the same subsystem as defined by param 3
1564 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY);
1565 MODULE_DEPEND(siftr, alq, 1, 1, 1);
1566 MODULE_VERSION(siftr, MODVERSION);