2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2007-2009
5 * Swinburne University of Technology, Melbourne, Australia.
6 * Copyright (c) 2009-2010, The FreeBSD Foundation
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.
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
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.
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
35 /******************************************************
36 * Statistical Information For TCP Research (SIFTR)
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.
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/
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/
56 * Lawrence Stewart is the current maintainer, and all contact regarding
57 * SIFTR should be directed to him via email: lastewart@swin.edu.au
59 * Initial release date: June 2007
60 * Most recent update: September 2010
61 ******************************************************/
63 #include <sys/cdefs.h>
64 __FBSDID("$FreeBSD$");
66 #include <sys/param.h>
68 #include <sys/errno.h>
69 #include <sys/eventhandler.h>
71 #include <sys/kernel.h>
72 #include <sys/kthread.h>
75 #include <sys/module.h>
76 #include <sys/mutex.h>
82 #include <sys/socket.h>
83 #include <sys/socketvar.h>
84 #include <sys/sysctl.h>
85 #include <sys/unistd.h>
88 #include <net/if_var.h>
91 #include <netinet/in.h>
92 #include <netinet/in_kdtrace.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/tcp_var.h>
100 #include <netinet/ip6.h>
101 #include <netinet6/in6_pcb.h>
102 #endif /* SIFTR_IPV6 */
104 #include <machine/in_cksum.h>
107 * Three digit version number refers to X.Y.Z where:
108 * X is the major version number
109 * Y is bumped to mark backwards incompatible changes
110 * Z is bumped to mark backwards compatible changes
113 #define V_BACKBREAK 2
114 #define V_BACKCOMPAT 4
115 #define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT))
116 #define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \
117 __XSTRING(V_BACKCOMPAT)
121 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536
122 #define SYS_NAME "FreeBSD"
123 #define PACKET_TAG_SIFTR 100
124 #define PACKET_COOKIE_SIFTR 21749576
125 #define SIFTR_LOG_FILE_MODE 0644
126 #define SIFTR_DISABLE 0
127 #define SIFTR_ENABLE 1
130 * Hard upper limit on the length of log messages. Bump this up if you add new
131 * data fields such that the line length could exceed the below value.
133 #define MAX_LOG_MSG_LEN 200
134 /* XXX: Make this a sysctl tunable. */
135 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN)
138 * 1 byte for IP version
139 * IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes
140 * IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes
143 #define FLOW_KEY_LEN 37
145 #define FLOW_KEY_LEN 13
149 #define SIFTR_IPMODE 6
151 #define SIFTR_IPMODE 4
155 #define CAST_PTR_INT(X) (*((int*)(X)))
157 #define UPPER_SHORT(X) (((X) & 0xFFFF0000) >> 16)
158 #define LOWER_SHORT(X) ((X) & 0x0000FFFF)
160 #define FIRST_OCTET(X) (((X) & 0xFF000000) >> 24)
161 #define SECOND_OCTET(X) (((X) & 0x00FF0000) >> 16)
162 #define THIRD_OCTET(X) (((X) & 0x0000FF00) >> 8)
163 #define FOURTH_OCTET(X) ((X) & 0x000000FF)
165 static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR");
166 static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode",
167 "SIFTR pkt_node struct");
168 static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode",
169 "SIFTR flow_hash_node struct");
171 /* Used as links in the pkt manager queue. */
173 /* Timestamp of pkt as noted in the pfil hook. */
175 /* Direction pkt is travelling; either PFIL_IN or PFIL_OUT. */
177 /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */
179 /* Hash of the pkt which triggered the log message. */
181 /* Local/foreign IP address. */
183 uint32_t ip_laddr[4];
184 uint32_t ip_faddr[4];
189 /* Local TCP port. */
190 uint16_t tcp_localport;
191 /* Foreign TCP port. */
192 uint16_t tcp_foreignport;
193 /* Congestion Window (bytes). */
195 /* Sending Window (bytes). */
197 /* Receive Window (bytes). */
199 /* Unused (was: Bandwidth Controlled Window (bytes)). */
201 /* Slow Start Threshold (bytes). */
203 /* Current state of the TCP FSM. */
205 /* Max Segment Size (bytes). */
208 * Smoothed RTT stored as found in the TCP control block
209 * in units of (TCP_RTT_SCALE*hz).
212 /* Is SACK enabled? */
214 /* Window scaling for snd window. */
216 /* Window scaling for recv window. */
218 /* TCP control block flags. */
220 /* Retransmit timeout length. */
222 /* Size of the TCP send buffer in bytes. */
223 u_int snd_buf_hiwater;
224 /* Current num bytes in the send socket buffer. */
226 /* Size of the TCP receive buffer in bytes. */
227 u_int rcv_buf_hiwater;
228 /* Current num bytes in the receive socket buffer. */
230 /* Number of bytes inflight that we are waiting on ACKs for. */
231 u_int sent_inflight_bytes;
232 /* Number of segments currently in the reassembly queue. */
234 /* Flowid for the connection. */
236 /* Flow type for the connection. */
238 /* Link to next pkt_node in the list. */
239 STAILQ_ENTRY(pkt_node) nodes;
242 struct flow_hash_node
245 uint8_t key[FLOW_KEY_LEN];
246 LIST_ENTRY(flow_hash_node) nodes;
251 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */
254 /* # pkts skipped due to failed malloc calls. */
255 uint32_t nskip_in_malloc;
256 uint32_t nskip_out_malloc;
257 /* # pkts skipped due to failed mtx acquisition. */
258 uint32_t nskip_in_mtx;
259 uint32_t nskip_out_mtx;
260 /* # pkts skipped due to failed inpcb lookups. */
261 uint32_t nskip_in_inpcb;
262 uint32_t nskip_out_inpcb;
263 /* # pkts skipped due to failed tcpcb lookups. */
264 uint32_t nskip_in_tcpcb;
265 uint32_t nskip_out_tcpcb;
266 /* # pkts skipped due to stack reinjection. */
267 uint32_t nskip_in_dejavu;
268 uint32_t nskip_out_dejavu;
271 static DPCPU_DEFINE(struct siftr_stats, ss);
273 static volatile unsigned int siftr_exit_pkt_manager_thread = 0;
274 static unsigned int siftr_enabled = 0;
275 static unsigned int siftr_pkts_per_log = 1;
276 static unsigned int siftr_generate_hashes = 0;
277 /* static unsigned int siftr_binary_log = 0; */
278 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log";
279 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log";
280 static u_long siftr_hashmask;
281 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue);
282 LIST_HEAD(listhead, flow_hash_node) *counter_hash;
283 static int wait_for_pkt;
284 static struct alq *siftr_alq = NULL;
285 static struct mtx siftr_pkt_queue_mtx;
286 static struct mtx siftr_pkt_mgr_mtx;
287 static struct thread *siftr_pkt_manager_thr = NULL;
289 * pfil.h defines PFIL_IN as 1 and PFIL_OUT as 2,
290 * which we use as an index into this array.
292 static char direction[3] = {'\0', 'i','o'};
294 /* Required function prototypes. */
295 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS);
296 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS);
299 /* Declare the net.inet.siftr sysctl tree and populate it. */
301 SYSCTL_DECL(_net_inet_siftr);
303 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW, NULL,
304 "siftr related settings");
306 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, CTLTYPE_UINT|CTLFLAG_RW,
307 &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU",
308 "switch siftr module operations on/off");
310 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, CTLTYPE_STRING|CTLFLAG_RW,
311 &siftr_logfile_shadow, sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler,
312 "A", "file to save siftr log messages to");
314 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW,
315 &siftr_pkts_per_log, 1,
316 "number of packets between generating a log message");
318 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW,
319 &siftr_generate_hashes, 0,
320 "enable packet hash generation");
323 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW,
324 &siftr_binary_log, 0,
325 "write log files in binary instead of ascii");
329 /* Begin functions. */
332 siftr_process_pkt(struct pkt_node * pkt_node)
334 struct flow_hash_node *hash_node;
335 struct listhead *counter_list;
336 struct siftr_stats *ss;
338 uint8_t key[FLOW_KEY_LEN];
339 uint8_t found_match, key_offset;
347 * Create the key that will be used to create a hash index
348 * into our hash table. Our key consists of:
349 * ipversion, localip, localport, foreignip, foreignport
351 key[0] = pkt_node->ipver;
352 memcpy(key + key_offset, &pkt_node->ip_laddr,
353 sizeof(pkt_node->ip_laddr));
354 key_offset += sizeof(pkt_node->ip_laddr);
355 memcpy(key + key_offset, &pkt_node->tcp_localport,
356 sizeof(pkt_node->tcp_localport));
357 key_offset += sizeof(pkt_node->tcp_localport);
358 memcpy(key + key_offset, &pkt_node->ip_faddr,
359 sizeof(pkt_node->ip_faddr));
360 key_offset += sizeof(pkt_node->ip_faddr);
361 memcpy(key + key_offset, &pkt_node->tcp_foreignport,
362 sizeof(pkt_node->tcp_foreignport));
364 counter_list = counter_hash +
365 (hash32_buf(key, sizeof(key), 0) & siftr_hashmask);
368 * If the list is not empty i.e. the hash index has
369 * been used by another flow previously.
371 if (LIST_FIRST(counter_list) != NULL) {
373 * Loop through the hash nodes in the list.
374 * There should normally only be 1 hash node in the list,
375 * except if there have been collisions at the hash index
376 * computed by hash32_buf().
378 LIST_FOREACH(hash_node, counter_list, nodes) {
380 * Check if the key for the pkt we are currently
381 * processing is the same as the key stored in the
382 * hash node we are currently processing.
383 * If they are the same, then we've found the
384 * hash node that stores the counter for the flow
385 * the pkt belongs to.
387 if (memcmp(hash_node->key, key, sizeof(key)) == 0) {
394 /* If this flow hash hasn't been seen before or we have a collision. */
395 if (hash_node == NULL || !found_match) {
396 /* Create a new hash node to store the flow's counter. */
397 hash_node = malloc(sizeof(struct flow_hash_node),
398 M_SIFTR_HASHNODE, M_WAITOK);
400 if (hash_node != NULL) {
401 /* Initialise our new hash node list entry. */
402 hash_node->counter = 0;
403 memcpy(hash_node->key, key, sizeof(key));
404 LIST_INSERT_HEAD(counter_list, hash_node, nodes);
407 if (pkt_node->direction == PFIL_IN)
408 ss->nskip_in_malloc++;
410 ss->nskip_out_malloc++;
414 } else if (siftr_pkts_per_log > 1) {
416 * Taking the remainder of the counter divided
417 * by the current value of siftr_pkts_per_log
418 * and storing that in counter provides a neat
419 * way to modulate the frequency of log
420 * messages being written to the log file.
422 hash_node->counter = (hash_node->counter + 1) %
426 * If we have not seen enough packets since the last time
427 * we wrote a log message for this connection, return.
429 if (hash_node->counter > 0)
433 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK);
436 return; /* Should only happen if the ALQ is shutting down. */
439 pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]);
440 pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]);
442 if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */
443 pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]);
444 pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]);
445 pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]);
446 pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]);
447 pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]);
448 pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]);
450 /* Construct an IPv6 log message. */
451 log_buf->ae_bytesused = snprintf(log_buf->ae_data,
453 "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:"
454 "%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,"
455 "%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n",
456 direction[pkt_node->direction],
458 pkt_node->tval.tv_sec,
459 pkt_node->tval.tv_usec,
460 UPPER_SHORT(pkt_node->ip_laddr[0]),
461 LOWER_SHORT(pkt_node->ip_laddr[0]),
462 UPPER_SHORT(pkt_node->ip_laddr[1]),
463 LOWER_SHORT(pkt_node->ip_laddr[1]),
464 UPPER_SHORT(pkt_node->ip_laddr[2]),
465 LOWER_SHORT(pkt_node->ip_laddr[2]),
466 UPPER_SHORT(pkt_node->ip_laddr[3]),
467 LOWER_SHORT(pkt_node->ip_laddr[3]),
468 ntohs(pkt_node->tcp_localport),
469 UPPER_SHORT(pkt_node->ip_faddr[0]),
470 LOWER_SHORT(pkt_node->ip_faddr[0]),
471 UPPER_SHORT(pkt_node->ip_faddr[1]),
472 LOWER_SHORT(pkt_node->ip_faddr[1]),
473 UPPER_SHORT(pkt_node->ip_faddr[2]),
474 LOWER_SHORT(pkt_node->ip_faddr[2]),
475 UPPER_SHORT(pkt_node->ip_faddr[3]),
476 LOWER_SHORT(pkt_node->ip_faddr[3]),
477 ntohs(pkt_node->tcp_foreignport),
478 pkt_node->snd_ssthresh,
485 pkt_node->conn_state,
486 pkt_node->max_seg_size,
487 pkt_node->smoothed_rtt,
488 pkt_node->sack_enabled,
490 pkt_node->rxt_length,
491 pkt_node->snd_buf_hiwater,
492 pkt_node->snd_buf_cc,
493 pkt_node->rcv_buf_hiwater,
494 pkt_node->rcv_buf_cc,
495 pkt_node->sent_inflight_bytes,
499 } else { /* IPv4 packet */
500 pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]);
501 pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]);
502 pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]);
503 pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]);
504 pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]);
505 pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]);
506 pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]);
507 pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]);
508 #endif /* SIFTR_IPV6 */
510 /* Construct an IPv4 log message. */
511 log_buf->ae_bytesused = snprintf(log_buf->ae_data,
513 "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld,"
514 "%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n",
515 direction[pkt_node->direction],
517 (intmax_t)pkt_node->tval.tv_sec,
518 pkt_node->tval.tv_usec,
519 pkt_node->ip_laddr[0],
520 pkt_node->ip_laddr[1],
521 pkt_node->ip_laddr[2],
522 pkt_node->ip_laddr[3],
523 ntohs(pkt_node->tcp_localport),
524 pkt_node->ip_faddr[0],
525 pkt_node->ip_faddr[1],
526 pkt_node->ip_faddr[2],
527 pkt_node->ip_faddr[3],
528 ntohs(pkt_node->tcp_foreignport),
529 pkt_node->snd_ssthresh,
536 pkt_node->conn_state,
537 pkt_node->max_seg_size,
538 pkt_node->smoothed_rtt,
539 pkt_node->sack_enabled,
541 pkt_node->rxt_length,
542 pkt_node->snd_buf_hiwater,
543 pkt_node->snd_buf_cc,
544 pkt_node->rcv_buf_hiwater,
545 pkt_node->rcv_buf_cc,
546 pkt_node->sent_inflight_bytes,
554 alq_post_flags(siftr_alq, log_buf, 0);
559 siftr_pkt_manager_thread(void *arg)
561 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue =
562 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue);
563 struct pkt_node *pkt_node, *pkt_node_temp;
568 mtx_lock(&siftr_pkt_mgr_mtx);
570 /* draining == 0 when queue has been flushed and it's safe to exit. */
573 * Sleep until we are signalled to wake because thread has
574 * been told to exit or until 1 tick has passed.
576 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait",
579 /* Gain exclusive access to the pkt_node queue. */
580 mtx_lock(&siftr_pkt_queue_mtx);
583 * Move pkt_queue to tmp_pkt_queue, which leaves
584 * pkt_queue empty and ready to receive more pkt_nodes.
586 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue);
589 * We've finished making changes to the list. Unlock it
590 * so the pfil hooks can continue queuing pkt_nodes.
592 mtx_unlock(&siftr_pkt_queue_mtx);
595 * We can't hold a mutex whilst calling siftr_process_pkt
596 * because ALQ might sleep waiting for buffer space.
598 mtx_unlock(&siftr_pkt_mgr_mtx);
600 /* Flush all pkt_nodes to the log file. */
601 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes,
603 siftr_process_pkt(pkt_node);
604 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes);
605 free(pkt_node, M_SIFTR_PKTNODE);
608 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue),
609 ("SIFTR tmp_pkt_queue not empty after flush"));
611 mtx_lock(&siftr_pkt_mgr_mtx);
614 * If siftr_exit_pkt_manager_thread gets set during the window
615 * where we are draining the tmp_pkt_queue above, there might
616 * still be pkts in pkt_queue that need to be drained.
617 * Allow one further iteration to occur after
618 * siftr_exit_pkt_manager_thread has been set to ensure
619 * pkt_queue is completely empty before we kill the thread.
621 * siftr_exit_pkt_manager_thread is set only after the pfil
622 * hooks have been removed, so only 1 extra iteration
623 * is needed to drain the queue.
625 if (siftr_exit_pkt_manager_thread)
629 mtx_unlock(&siftr_pkt_mgr_mtx);
631 /* Calls wakeup on this thread's struct thread ptr. */
637 hash_pkt(struct mbuf *m, uint32_t offset)
643 while (m != NULL && offset > m->m_len) {
645 * The IP packet payload does not start in this mbuf, so
646 * need to figure out which mbuf it starts in and what offset
647 * into the mbuf's data region the payload starts at.
654 /* Ensure there is data in the mbuf */
655 if ((m->m_len - offset) > 0)
656 hash = hash32_buf(m->m_data + offset,
657 m->m_len - offset, hash);
668 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that
669 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return.
670 * Return value >0 means the caller should skip processing this mbuf.
673 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss)
675 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL)
678 ss->nskip_in_dejavu++;
680 ss->nskip_out_dejavu++;
684 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR,
685 PACKET_TAG_SIFTR, 0, M_NOWAIT);
688 ss->nskip_in_malloc++;
690 ss->nskip_out_malloc++;
695 m_tag_prepend(m, tag);
703 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL
706 static inline struct inpcb *
707 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport,
708 uint16_t dport, int dir, struct siftr_stats *ss)
712 /* We need the tcbinfo lock. */
713 INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
716 inp = (ipver == INP_IPV4 ?
717 in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst,
718 dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
721 in6_pcblookup(&V_tcbinfo,
722 &((struct ip6_hdr *)ip)->ip6_src, sport,
723 &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB,
731 inp = (ipver == INP_IPV4 ?
732 in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src,
733 sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
736 in6_pcblookup(&V_tcbinfo,
737 &((struct ip6_hdr *)ip)->ip6_dst, dport,
738 &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB,
745 /* If we can't find the inpcb, bail. */
748 ss->nskip_in_inpcb++;
750 ss->nskip_out_inpcb++;
758 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp,
759 int ipver, int dir, int inp_locally_locked)
762 if (ipver == INP_IPV4) {
763 pn->ip_laddr[3] = inp->inp_laddr.s_addr;
764 pn->ip_faddr[3] = inp->inp_faddr.s_addr;
766 *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr;
767 *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr;
771 pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0];
772 pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1];
773 pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2];
774 pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3];
775 pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0];
776 pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1];
777 pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2];
778 pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3];
781 pn->tcp_localport = inp->inp_lport;
782 pn->tcp_foreignport = inp->inp_fport;
783 pn->snd_cwnd = tp->snd_cwnd;
784 pn->snd_wnd = tp->snd_wnd;
785 pn->rcv_wnd = tp->rcv_wnd;
786 pn->snd_bwnd = 0; /* Unused, kept for compat. */
787 pn->snd_ssthresh = tp->snd_ssthresh;
788 pn->snd_scale = tp->snd_scale;
789 pn->rcv_scale = tp->rcv_scale;
790 pn->conn_state = tp->t_state;
791 pn->max_seg_size = tp->t_maxseg;
792 pn->smoothed_rtt = tp->t_srtt;
793 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0;
794 pn->flags = tp->t_flags;
795 pn->rxt_length = tp->t_rxtcur;
796 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat;
797 pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd);
798 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat;
799 pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv);
800 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una;
801 pn->t_segqlen = tp->t_segqlen;
802 pn->flowid = inp->inp_flowid;
803 pn->flowtype = inp->inp_flowtype;
805 /* We've finished accessing the tcb so release the lock. */
806 if (inp_locally_locked)
813 * Significantly more accurate than using getmicrotime(), but slower!
814 * Gives true microsecond resolution at the expense of a hit to
815 * maximum pps throughput processing when SIFTR is loaded and enabled.
817 microtime(&pn->tval);
818 TCP_PROBE1(siftr, &pn);
824 * pfil hook that is called for each IPv4 packet making its way through the
825 * stack in either direction.
826 * The pfil subsystem holds a non-sleepable mutex somewhere when
827 * calling our hook function, so we can't sleep at all.
828 * It's very important to use the M_NOWAIT flag with all function calls
829 * that support it so that they won't sleep, otherwise you get a panic.
832 siftr_chkpkt(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
839 struct siftr_stats *ss;
841 int inp_locally_locked;
843 inp_locally_locked = 0;
847 * m_pullup is not required here because ip_{input|output}
848 * already do the heavy lifting for us.
851 ip = mtod(*m, struct ip *);
853 /* Only continue processing if the packet is TCP. */
854 if (ip->ip_p != IPPROTO_TCP)
858 * If a kernel subsystem reinjects packets into the stack, our pfil
859 * hook will be called multiple times for the same packet.
860 * Make sure we only process unique packets.
862 if (siftr_chkreinject(*m, dir, ss))
871 * Create a tcphdr struct starting at the correct offset
872 * in the IP packet. ip->ip_hl gives the ip header length
873 * in 4-byte words, so multiply it to get the size in bytes.
875 ip_hl = (ip->ip_hl << 2);
876 th = (struct tcphdr *)((caddr_t)ip + ip_hl);
879 * If the pfil hooks don't provide a pointer to the
880 * inpcb, we need to find it ourselves and lock it.
883 /* Find the corresponding inpcb for this pkt. */
884 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport,
885 th->th_dport, dir, ss);
890 inp_locally_locked = 1;
893 INP_LOCK_ASSERT(inp);
895 /* Find the TCP control block that corresponds with this packet */
899 * If we can't find the TCP control block (happens occasionaly for a
900 * packet sent during the shutdown phase of a TCP connection),
901 * or we're in the timewait state, bail
903 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
905 ss->nskip_in_tcpcb++;
907 ss->nskip_out_tcpcb++;
912 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
916 ss->nskip_in_malloc++;
918 ss->nskip_out_malloc++;
923 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked);
925 if (siftr_generate_hashes) {
926 if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) {
928 * For outbound packets, the TCP checksum isn't
929 * calculated yet. This is a problem for our packet
930 * hashing as the receiver will calc a different hash
931 * to ours if we don't include the correct TCP checksum
932 * in the bytes being hashed. To work around this
933 * problem, we manually calc the TCP checksum here in
934 * software. We unset the CSUM_TCP flag so the lower
935 * layers don't recalc it.
937 (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP;
940 * Calculate the TCP checksum in software and assign
941 * to correct TCP header field, which will follow the
942 * packet mbuf down the stack. The trick here is that
943 * tcp_output() sets th->th_sum to the checksum of the
944 * pseudo header for us already. Because of the nature
945 * of the checksumming algorithm, we can sum over the
946 * entire IP payload (i.e. TCP header and data), which
947 * will include the already calculated pseduo header
948 * checksum, thus giving us the complete TCP checksum.
950 * To put it in simple terms, if checksum(1,2,3,4)=10,
951 * then checksum(1,2,3,4,5) == checksum(10,5).
952 * This property is what allows us to "cheat" and
953 * checksum only the IP payload which has the TCP
954 * th_sum field populated with the pseudo header's
955 * checksum, and not need to futz around checksumming
956 * pseudo header bytes and TCP header/data in one hit.
957 * Refer to RFC 1071 for more info.
959 * NB: in_cksum_skip(struct mbuf *m, int len, int skip)
960 * in_cksum_skip 2nd argument is NOT the number of
961 * bytes to read from the mbuf at "skip" bytes offset
962 * from the start of the mbuf (very counter intuitive!).
963 * The number of bytes to read is calculated internally
964 * by the function as len-skip i.e. to sum over the IP
965 * payload (TCP header + data) bytes, it is INCORRECT
966 * to call the function like this:
967 * in_cksum_skip(at, ip->ip_len - offset, offset)
968 * Rather, it should be called like this:
969 * in_cksum_skip(at, ip->ip_len, offset)
970 * which means read "ip->ip_len - offset" bytes from
971 * the mbuf cluster "at" at offset "offset" bytes from
972 * the beginning of the "at" mbuf's data pointer.
974 th->th_sum = in_cksum_skip(*m, ntohs(ip->ip_len),
979 * XXX: Having to calculate the checksum in software and then
980 * hash over all bytes is really inefficient. Would be nice to
981 * find a way to create the hash and checksum in the same pass
984 pn->hash = hash_pkt(*m, ip_hl);
987 mtx_lock(&siftr_pkt_queue_mtx);
988 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
989 mtx_unlock(&siftr_pkt_queue_mtx);
993 if (inp_locally_locked)
997 /* Returning 0 ensures pfil will not discard the pkt */
1004 siftr_chkpkt6(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
1007 struct pkt_node *pn;
1008 struct ip6_hdr *ip6;
1011 struct siftr_stats *ss;
1012 unsigned int ip6_hl;
1013 int inp_locally_locked;
1015 inp_locally_locked = 0;
1019 * m_pullup is not required here because ip6_{input|output}
1020 * already do the heavy lifting for us.
1023 ip6 = mtod(*m, struct ip6_hdr *);
1026 * Only continue processing if the packet is TCP
1027 * XXX: We should follow the next header fields
1028 * as shown on Pg 6 RFC 2460, but right now we'll
1029 * only check pkts that have no extension headers.
1031 if (ip6->ip6_nxt != IPPROTO_TCP)
1035 * If a kernel subsystem reinjects packets into the stack, our pfil
1036 * hook will be called multiple times for the same packet.
1037 * Make sure we only process unique packets.
1039 if (siftr_chkreinject(*m, dir, ss))
1047 ip6_hl = sizeof(struct ip6_hdr);
1050 * Create a tcphdr struct starting at the correct offset
1051 * in the ipv6 packet. ip->ip_hl gives the ip header length
1052 * in 4-byte words, so multiply it to get the size in bytes.
1054 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl);
1057 * For inbound packets, the pfil hooks don't provide a pointer to the
1058 * inpcb, so we need to find it ourselves and lock it.
1061 /* Find the corresponding inpcb for this pkt. */
1062 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m,
1063 th->th_sport, th->th_dport, dir, ss);
1068 inp_locally_locked = 1;
1071 /* Find the TCP control block that corresponds with this packet. */
1072 tp = intotcpcb(inp);
1075 * If we can't find the TCP control block (happens occasionaly for a
1076 * packet sent during the shutdown phase of a TCP connection),
1077 * or we're in the timewait state, bail.
1079 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
1081 ss->nskip_in_tcpcb++;
1083 ss->nskip_out_tcpcb++;
1088 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
1092 ss->nskip_in_malloc++;
1094 ss->nskip_out_malloc++;
1099 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked);
1101 /* XXX: Figure out how to generate hashes for IPv6 packets. */
1103 mtx_lock(&siftr_pkt_queue_mtx);
1104 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
1105 mtx_unlock(&siftr_pkt_queue_mtx);
1109 if (inp_locally_locked)
1113 /* Returning 0 ensures pfil will not discard the pkt. */
1116 #endif /* #ifdef SIFTR_IPV6 */
1120 siftr_pfil(int action)
1122 struct pfil_head *pfh_inet;
1124 struct pfil_head *pfh_inet6;
1126 VNET_ITERATOR_DECL(vnet_iter);
1129 VNET_FOREACH(vnet_iter) {
1130 CURVNET_SET(vnet_iter);
1131 pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
1133 pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
1136 if (action == HOOK) {
1137 pfil_add_hook(siftr_chkpkt, NULL,
1138 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet);
1140 pfil_add_hook(siftr_chkpkt6, NULL,
1141 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6);
1143 } else if (action == UNHOOK) {
1144 pfil_remove_hook(siftr_chkpkt, NULL,
1145 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet);
1147 pfil_remove_hook(siftr_chkpkt6, NULL,
1148 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6);
1153 VNET_LIST_RUNLOCK();
1160 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS)
1162 struct alq *new_alq;
1165 error = sysctl_handle_string(oidp, arg1, arg2, req);
1167 /* Check for error or same filename */
1168 if (error != 0 || req->newptr == NULL ||
1169 strncmp(siftr_logfile, arg1, arg2) == 0)
1172 /* Filname changed */
1173 error = alq_open(&new_alq, arg1, curthread->td_ucred,
1174 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1179 * If disabled, siftr_alq == NULL so we simply close
1180 * the alq as we've proved it can be opened.
1181 * If enabled, close the existing alq and switch the old
1184 if (siftr_alq == NULL) {
1187 alq_close(siftr_alq);
1188 siftr_alq = new_alq;
1191 /* Update filename upon success */
1192 strlcpy(siftr_logfile, arg1, arg2);
1198 siftr_manage_ops(uint8_t action)
1200 struct siftr_stats totalss;
1201 struct timeval tval;
1202 struct flow_hash_node *counter, *tmp_counter;
1204 int i, key_index, ret, error;
1205 uint32_t bytes_to_write, total_skipped_pkts;
1206 uint16_t lport, fport;
1207 uint8_t *key, ipver;
1218 total_skipped_pkts = 0;
1220 /* Init an autosizing sbuf that initially holds 200 chars. */
1221 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL)
1224 if (action == SIFTR_ENABLE) {
1227 * XXX: We should abort if alq_open fails!
1229 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred,
1230 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1232 STAILQ_INIT(&pkt_queue);
1236 siftr_exit_pkt_manager_thread = 0;
1238 ret = kthread_add(&siftr_pkt_manager_thread, NULL, NULL,
1239 &siftr_pkt_manager_thr, RFNOWAIT, 0,
1240 "siftr_pkt_manager_thr");
1247 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t"
1248 "siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t"
1249 "sysver=%u\tipmode=%u\n",
1250 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz,
1251 TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE);
1254 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK);
1256 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) {
1258 * Remove the pfil hook functions. All threads currently in
1259 * the hook functions are allowed to exit before siftr_pfil()
1264 /* This will block until the pkt manager thread unlocks it. */
1265 mtx_lock(&siftr_pkt_mgr_mtx);
1267 /* Tell the pkt manager thread that it should exit now. */
1268 siftr_exit_pkt_manager_thread = 1;
1271 * Wake the pkt_manager thread so it realises that
1272 * siftr_exit_pkt_manager_thread == 1 and exits gracefully.
1273 * The wakeup won't be delivered until we unlock
1274 * siftr_pkt_mgr_mtx so this isn't racy.
1276 wakeup(&wait_for_pkt);
1278 /* Wait for the pkt_manager thread to exit. */
1279 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT,
1282 siftr_pkt_manager_thr = NULL;
1283 mtx_unlock(&siftr_pkt_mgr_mtx);
1285 totalss.n_in = DPCPU_VARSUM(ss, n_in);
1286 totalss.n_out = DPCPU_VARSUM(ss, n_out);
1287 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc);
1288 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc);
1289 totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx);
1290 totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx);
1291 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb);
1292 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb);
1293 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb);
1294 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb);
1296 total_skipped_pkts = totalss.nskip_in_malloc +
1297 totalss.nskip_out_malloc + totalss.nskip_in_mtx +
1298 totalss.nskip_out_mtx + totalss.nskip_in_tcpcb +
1299 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb +
1300 totalss.nskip_out_inpcb;
1305 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t"
1306 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t"
1307 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t"
1308 "num_outbound_skipped_pkts_malloc=%u\t"
1309 "num_inbound_skipped_pkts_mtx=%u\t"
1310 "num_outbound_skipped_pkts_mtx=%u\t"
1311 "num_inbound_skipped_pkts_tcpcb=%u\t"
1312 "num_outbound_skipped_pkts_tcpcb=%u\t"
1313 "num_inbound_skipped_pkts_inpcb=%u\t"
1314 "num_outbound_skipped_pkts_inpcb=%u\t"
1315 "total_skipped_tcp_pkts=%u\tflow_list=",
1316 (intmax_t)tval.tv_sec,
1318 (uintmax_t)totalss.n_in,
1319 (uintmax_t)totalss.n_out,
1320 (uintmax_t)(totalss.n_in + totalss.n_out),
1321 totalss.nskip_in_malloc,
1322 totalss.nskip_out_malloc,
1323 totalss.nskip_in_mtx,
1324 totalss.nskip_out_mtx,
1325 totalss.nskip_in_tcpcb,
1326 totalss.nskip_out_tcpcb,
1327 totalss.nskip_in_inpcb,
1328 totalss.nskip_out_inpcb,
1329 total_skipped_pkts);
1332 * Iterate over the flow hash, printing a summary of each
1333 * flow seen and freeing any malloc'd memory.
1334 * The hash consists of an array of LISTs (man 3 queue).
1336 for (i = 0; i <= siftr_hashmask; i++) {
1337 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes,
1344 memcpy(laddr, key + key_index, sizeof(laddr));
1345 key_index += sizeof(laddr);
1346 memcpy(&lport, key + key_index, sizeof(lport));
1347 key_index += sizeof(lport);
1348 memcpy(faddr, key + key_index, sizeof(faddr));
1349 key_index += sizeof(faddr);
1350 memcpy(&fport, key + key_index, sizeof(fport));
1353 laddr[3] = ntohl(laddr[3]);
1354 faddr[3] = ntohl(faddr[3]);
1356 if (ipver == INP_IPV6) {
1357 laddr[0] = ntohl(laddr[0]);
1358 laddr[1] = ntohl(laddr[1]);
1359 laddr[2] = ntohl(laddr[2]);
1360 faddr[0] = ntohl(faddr[0]);
1361 faddr[1] = ntohl(faddr[1]);
1362 faddr[2] = ntohl(faddr[2]);
1365 "%x:%x:%x:%x:%x:%x:%x:%x;%u-"
1366 "%x:%x:%x:%x:%x:%x:%x:%x;%u,",
1367 UPPER_SHORT(laddr[0]),
1368 LOWER_SHORT(laddr[0]),
1369 UPPER_SHORT(laddr[1]),
1370 LOWER_SHORT(laddr[1]),
1371 UPPER_SHORT(laddr[2]),
1372 LOWER_SHORT(laddr[2]),
1373 UPPER_SHORT(laddr[3]),
1374 LOWER_SHORT(laddr[3]),
1376 UPPER_SHORT(faddr[0]),
1377 LOWER_SHORT(faddr[0]),
1378 UPPER_SHORT(faddr[1]),
1379 LOWER_SHORT(faddr[1]),
1380 UPPER_SHORT(faddr[2]),
1381 LOWER_SHORT(faddr[2]),
1382 UPPER_SHORT(faddr[3]),
1383 LOWER_SHORT(faddr[3]),
1386 laddr[0] = FIRST_OCTET(laddr[3]);
1387 laddr[1] = SECOND_OCTET(laddr[3]);
1388 laddr[2] = THIRD_OCTET(laddr[3]);
1389 laddr[3] = FOURTH_OCTET(laddr[3]);
1390 faddr[0] = FIRST_OCTET(faddr[3]);
1391 faddr[1] = SECOND_OCTET(faddr[3]);
1392 faddr[2] = THIRD_OCTET(faddr[3]);
1393 faddr[3] = FOURTH_OCTET(faddr[3]);
1396 "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,",
1411 free(counter, M_SIFTR_HASHNODE);
1414 LIST_INIT(counter_hash + i);
1417 sbuf_printf(s, "\n");
1422 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i);
1423 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK);
1424 i += bytes_to_write;
1425 } while (i < sbuf_len(s));
1427 alq_close(siftr_alq);
1434 * XXX: Should be using ret to check if any functions fail
1435 * and set error appropriately
1443 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS)
1445 if (req->newptr == NULL)
1448 /* If the value passed in isn't 0 or 1, return an error. */
1449 if (CAST_PTR_INT(req->newptr) != 0 && CAST_PTR_INT(req->newptr) != 1)
1452 /* If we are changing state (0 to 1 or 1 to 0). */
1453 if (CAST_PTR_INT(req->newptr) != siftr_enabled )
1454 if (siftr_manage_ops(CAST_PTR_INT(req->newptr))) {
1455 siftr_manage_ops(SIFTR_DISABLE);
1460 return (sysctl_handle_int(oidp, arg1, arg2, req));
1465 siftr_shutdown_handler(void *arg)
1467 siftr_manage_ops(SIFTR_DISABLE);
1472 * Module is being unloaded or machine is shutting down. Take care of cleanup.
1478 siftr_manage_ops(SIFTR_DISABLE);
1479 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask);
1480 mtx_destroy(&siftr_pkt_queue_mtx);
1481 mtx_destroy(&siftr_pkt_mgr_mtx);
1488 * Module has just been loaded into the kernel.
1493 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL,
1494 SHUTDOWN_PRI_FIRST);
1496 /* Initialise our flow counter hash table. */
1497 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR,
1500 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF);
1501 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF);
1503 /* Print message to the user's current terminal. */
1504 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n"
1505 " http://caia.swin.edu.au/urp/newtcp\n\n",
1513 * This is the function that is called to load and unload the module.
1514 * When the module is loaded, this function is called once with
1515 * "what" == MOD_LOAD
1516 * When the module is unloaded, this function is called twice with
1517 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second
1518 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command,
1519 * this function is called once with "what" = MOD_SHUTDOWN
1520 * When the system is shut down, the handler isn't called until the very end
1521 * of the shutdown sequence i.e. after the disks have been synced.
1524 siftr_load_handler(module_t mod, int what, void *arg)
1535 ret = deinit_siftr();
1551 static moduledata_t siftr_mod = {
1553 .evhand = siftr_load_handler,
1557 * Param 1: name of the kernel module
1558 * Param 2: moduledata_t struct containing info about the kernel module
1559 * and the execution entry point for the module
1560 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h
1561 * Defines the module initialisation order
1562 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h
1563 * Defines the initialisation order of this kld relative to others
1564 * within the same subsystem as defined by param 3
1566 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY);
1567 MODULE_DEPEND(siftr, alq, 1, 1, 1);
1568 MODULE_VERSION(siftr, MODVERSION);