1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2007-2009
5 * Swinburne University of Technology, Melbourne, Australia.
6 * Copyright (c) 2009-2010, The FreeBSD Foundation
7 * All rights reserved.
8 *
9 * Portions of this software were developed at the Centre for Advanced
10 * Internet Architectures, Swinburne University of Technology, Melbourne,
11 * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 /******************************************************
36 * Statistical Information For TCP Research (SIFTR)
37 *
38 * A FreeBSD kernel module that adds very basic intrumentation to the
39 * TCP stack, allowing internal stats to be recorded to a log file
40 * for experimental, debugging and performance analysis purposes.
41 *
42 * SIFTR was first released in 2007 by James Healy and Lawrence Stewart whilst
43 * working on the NewTCP research project at Swinburne University of
44 * Technology's Centre for Advanced Internet Architectures, Melbourne,
45 * Australia, which was made possible in part by a grant from the Cisco
46 * University Research Program Fund at Community Foundation Silicon Valley.
47 * More details are available at:
48 * http://caia.swin.edu.au/urp/newtcp/
49 *
50 * Work on SIFTR v1.2.x was sponsored by the FreeBSD Foundation as part of
51 * the "Enhancing the FreeBSD TCP Implementation" project 2008-2009.
52 * More details are available at:
53 * http://www.freebsdfoundation.org/
54 * http://caia.swin.edu.au/freebsd/etcp09/
55 *
56 * Lawrence Stewart is the current maintainer, and all contact regarding
57 * SIFTR should be directed to him via email: lastewart@swin.edu.au
58 *
59 * Initial release date: June 2007
60 * Most recent update: September 2010
61 ******************************************************/
62
63 #include <sys/cdefs.h>
64 #include <sys/param.h>
65 #include <sys/alq.h>
66 #include <sys/errno.h>
67 #include <sys/eventhandler.h>
68 #include <sys/hash.h>
69 #include <sys/kernel.h>
70 #include <sys/kthread.h>
71 #include <sys/lock.h>
72 #include <sys/mbuf.h>
73 #include <sys/module.h>
74 #include <sys/mutex.h>
75 #include <sys/pcpu.h>
76 #include <sys/proc.h>
77 #include <sys/reboot.h>
78 #include <sys/sbuf.h>
79 #include <sys/sdt.h>
80 #include <sys/smp.h>
81 #include <sys/socket.h>
82 #include <sys/socketvar.h>
83 #include <sys/sysctl.h>
84 #include <sys/unistd.h>
85
86 #include <net/if.h>
87 #include <net/if_var.h>
88 #include <net/pfil.h>
89 #include <net/route.h>
90
91 #include <netinet/in.h>
92 #include <netinet/in_kdtrace.h>
93 #include <netinet/in_fib.h>
94 #include <netinet/in_pcb.h>
95 #include <netinet/in_systm.h>
96 #include <netinet/in_var.h>
97 #include <netinet/ip.h>
98 #include <netinet/ip_var.h>
99 #include <netinet/tcp_var.h>
100
101 #ifdef SIFTR_IPV6
102 #include <netinet/ip6.h>
103 #include <netinet6/ip6_var.h>
104 #include <netinet6/in6_fib.h>
105 #include <netinet6/in6_pcb.h>
106 #endif /* SIFTR_IPV6 */
107
108 #include <machine/in_cksum.h>
109
110 /*
111 * Three digit version number refers to X.Y.Z where:
112 * X is the major version number
113 * Y is bumped to mark backwards incompatible changes
114 * Z is bumped to mark backwards compatible changes
115 */
116 #define V_MAJOR 1
117 #define V_BACKBREAK 3
118 #define V_BACKCOMPAT 0
119 #define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT))
120 #define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \
121 __XSTRING(V_BACKCOMPAT)
122
123 #define HOOK 0
124 #define UNHOOK 1
125 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536
126 #define SYS_NAME "FreeBSD"
127 #define PACKET_TAG_SIFTR 100
128 #define PACKET_COOKIE_SIFTR 21749576
129 #define SIFTR_LOG_FILE_MODE 0644
130 #define SIFTR_DISABLE 0
131 #define SIFTR_ENABLE 1
132
133 /*
134 * Hard upper limit on the length of log messages. Bump this up if you add new
135 * data fields such that the line length could exceed the below value.
136 */
137 #define MAX_LOG_MSG_LEN 300
138 /* XXX: Make this a sysctl tunable. */
139 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN)
140
141 #ifdef SIFTR_IPV6
142 #define SIFTR_IPMODE 6
143 #else
144 #define SIFTR_IPMODE 4
145 #endif
146
147 static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR");
148 static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode",
149 "SIFTR pkt_node struct");
150 static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode",
151 "SIFTR flow_hash_node struct");
152
153 /* Used as links in the pkt manager queue. */
154 struct pkt_node {
155 /* Timestamp of pkt as noted in the pfil hook. */
156 struct timeval tval;
157 /* Direction pkt is travelling. */
158 enum {
159 DIR_IN = 0,
160 DIR_OUT = 1,
161 } direction;
162 /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */
163 uint8_t ipver;
164 /* Local TCP port. */
165 uint16_t lport;
166 /* Foreign TCP port. */
167 uint16_t fport;
168 /* Local address. */
169 union in_dependaddr laddr;
170 /* Foreign address. */
171 union in_dependaddr faddr;
172 /* Congestion Window (bytes). */
173 uint32_t snd_cwnd;
174 /* Sending Window (bytes). */
175 uint32_t snd_wnd;
176 /* Receive Window (bytes). */
177 uint32_t rcv_wnd;
178 /* More tcpcb flags storage */
179 uint32_t t_flags2;
180 /* Slow Start Threshold (bytes). */
181 uint32_t snd_ssthresh;
182 /* Current state of the TCP FSM. */
183 int conn_state;
184 /* Max Segment Size (bytes). */
185 uint32_t mss;
186 /* Smoothed RTT (usecs). */
187 uint32_t srtt;
188 /* Is SACK enabled? */
189 u_char sack_enabled;
190 /* Window scaling for snd window. */
191 u_char snd_scale;
192 /* Window scaling for recv window. */
193 u_char rcv_scale;
194 /* TCP control block flags. */
195 u_int t_flags;
196 /* Retransmission timeout (usec). */
197 uint32_t rto;
198 /* Size of the TCP send buffer in bytes. */
199 u_int snd_buf_hiwater;
200 /* Current num bytes in the send socket buffer. */
201 u_int snd_buf_cc;
202 /* Size of the TCP receive buffer in bytes. */
203 u_int rcv_buf_hiwater;
204 /* Current num bytes in the receive socket buffer. */
205 u_int rcv_buf_cc;
206 /* Number of bytes inflight that we are waiting on ACKs for. */
207 u_int sent_inflight_bytes;
208 /* Number of segments currently in the reassembly queue. */
209 int t_segqlen;
210 /* Flowid for the connection. */
211 u_int flowid;
212 /* Flow type for the connection. */
213 u_int flowtype;
214 /* Link to next pkt_node in the list. */
215 STAILQ_ENTRY(pkt_node) nodes;
216 };
217
218 struct flow_info
219 {
220 #ifdef SIFTR_IPV6
221 char laddr[INET6_ADDRSTRLEN]; /* local IP address */
222 char faddr[INET6_ADDRSTRLEN]; /* foreign IP address */
223 #else
224 char laddr[INET_ADDRSTRLEN]; /* local IP address */
225 char faddr[INET_ADDRSTRLEN]; /* foreign IP address */
226 #endif
227 uint16_t lport; /* local TCP port */
228 uint16_t fport; /* foreign TCP port */
229 uint32_t key; /* flowid of the connection */
230 };
231
232 struct flow_hash_node
233 {
234 uint16_t counter;
235 struct flow_info const_info; /* constant connection info */
236 LIST_ENTRY(flow_hash_node) nodes;
237 };
238
239 struct siftr_stats
240 {
241 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */
242 uint64_t n_in;
243 uint64_t n_out;
244 /* # pkts skipped due to failed malloc calls. */
245 uint32_t nskip_in_malloc;
246 uint32_t nskip_out_malloc;
247 /* # pkts skipped due to failed inpcb lookups. */
248 uint32_t nskip_in_inpcb;
249 uint32_t nskip_out_inpcb;
250 /* # pkts skipped due to failed tcpcb lookups. */
251 uint32_t nskip_in_tcpcb;
252 uint32_t nskip_out_tcpcb;
253 /* # pkts skipped due to stack reinjection. */
254 uint32_t nskip_in_dejavu;
255 uint32_t nskip_out_dejavu;
256 };
257
258 DPCPU_DEFINE_STATIC(struct siftr_stats, ss);
259
260 static volatile unsigned int siftr_exit_pkt_manager_thread = 0;
261 static unsigned int siftr_enabled = 0;
262 static unsigned int siftr_pkts_per_log = 1;
263 static uint16_t siftr_port_filter = 0;
264 /* static unsigned int siftr_binary_log = 0; */
265 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log";
266 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log";
267 static u_long siftr_hashmask;
268 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue);
269 LIST_HEAD(listhead, flow_hash_node) *counter_hash;
270 static int wait_for_pkt;
271 static struct alq *siftr_alq = NULL;
272 static struct mtx siftr_pkt_queue_mtx;
273 static struct mtx siftr_pkt_mgr_mtx;
274 static struct thread *siftr_pkt_manager_thr = NULL;
275 static char direction[2] = {'i','o'};
276 static eventhandler_tag siftr_shutdown_tag;
277
278 /* Required function prototypes. */
279 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS);
280 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS);
281
282 /* Declare the net.inet.siftr sysctl tree and populate it. */
283
284 SYSCTL_DECL(_net_inet_siftr);
285
286 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
287 "siftr related settings");
288
289 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled,
290 CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
291 &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU",
292 "switch siftr module operations on/off");
293
294 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile,
295 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &siftr_logfile_shadow,
296 sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler, "A",
297 "file to save siftr log messages to");
298
299 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW,
300 &siftr_pkts_per_log, 1,
301 "number of packets between generating a log message");
302
303 SYSCTL_U16(_net_inet_siftr, OID_AUTO, port_filter, CTLFLAG_RW,
304 &siftr_port_filter, 0,
305 "enable packet filter on a TCP port");
306
307 /* XXX: TODO
308 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW,
309 &siftr_binary_log, 0,
310 "write log files in binary instead of ascii");
311 */
312
313 /* Begin functions. */
314
315 static inline struct flow_hash_node *
siftr_find_flow(struct listhead * counter_list,uint32_t id)316 siftr_find_flow(struct listhead *counter_list, uint32_t id)
317 {
318 struct flow_hash_node *hash_node;
319 /*
320 * If the list is not empty i.e. the hash index has
321 * been used by another flow previously.
322 */
323 if (LIST_FIRST(counter_list) != NULL) {
324 /*
325 * Loop through the hash nodes in the list.
326 * There should normally only be 1 hash node in the list.
327 */
328 LIST_FOREACH(hash_node, counter_list, nodes) {
329 /*
330 * Check if the key for the pkt we are currently
331 * processing is the same as the key stored in the
332 * hash node we are currently processing.
333 * If they are the same, then we've found the
334 * hash node that stores the counter for the flow
335 * the pkt belongs to.
336 */
337 if (hash_node->const_info.key == id) {
338 return hash_node;
339 }
340 }
341 }
342
343 return NULL;
344 }
345
346 static inline struct flow_hash_node *
siftr_new_hash_node(struct flow_info info,int dir,struct siftr_stats * ss)347 siftr_new_hash_node(struct flow_info info, int dir,
348 struct siftr_stats *ss)
349 {
350 struct flow_hash_node *hash_node;
351 struct listhead *counter_list;
352
353 counter_list = counter_hash + (info.key & siftr_hashmask);
354 /* Create a new hash node to store the flow's constant info. */
355 hash_node = malloc(sizeof(struct flow_hash_node), M_SIFTR_HASHNODE,
356 M_NOWAIT|M_ZERO);
357
358 if (hash_node != NULL) {
359 /* Initialise our new hash node list entry. */
360 hash_node->counter = 0;
361 hash_node->const_info = info;
362 LIST_INSERT_HEAD(counter_list, hash_node, nodes);
363 return hash_node;
364 } else {
365 /* malloc failed */
366 if (dir == DIR_IN)
367 ss->nskip_in_malloc++;
368 else
369 ss->nskip_out_malloc++;
370
371 return NULL;
372 }
373 }
374
375 static void
siftr_process_pkt(struct pkt_node * pkt_node)376 siftr_process_pkt(struct pkt_node * pkt_node)
377 {
378 struct flow_hash_node *hash_node;
379 struct listhead *counter_list;
380 struct ale *log_buf;
381
382 if (pkt_node->flowid == 0) {
383 panic("%s: flowid not available", __func__);
384 }
385
386 counter_list = counter_hash + (pkt_node->flowid & siftr_hashmask);
387 hash_node = siftr_find_flow(counter_list, pkt_node->flowid);
388
389 if (hash_node == NULL) {
390 return;
391 } else if (siftr_pkts_per_log > 1) {
392 /*
393 * Taking the remainder of the counter divided
394 * by the current value of siftr_pkts_per_log
395 * and storing that in counter provides a neat
396 * way to modulate the frequency of log
397 * messages being written to the log file.
398 */
399 hash_node->counter = (hash_node->counter + 1) %
400 siftr_pkts_per_log;
401 /*
402 * If we have not seen enough packets since the last time
403 * we wrote a log message for this connection, return.
404 */
405 if (hash_node->counter > 0)
406 return;
407 }
408
409 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK);
410
411 if (log_buf == NULL)
412 return; /* Should only happen if the ALQ is shutting down. */
413
414 /* Construct a log message. */
415 log_buf->ae_bytesused = snprintf(log_buf->ae_data, MAX_LOG_MSG_LEN,
416 "%c,%jd.%06ld,%s,%hu,%s,%hu,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,"
417 "%u,%u,%u,%u,%u,%u,%u,%u\n",
418 direction[pkt_node->direction],
419 (intmax_t)pkt_node->tval.tv_sec,
420 pkt_node->tval.tv_usec,
421 hash_node->const_info.laddr,
422 hash_node->const_info.lport,
423 hash_node->const_info.faddr,
424 hash_node->const_info.fport,
425 pkt_node->snd_ssthresh,
426 pkt_node->snd_cwnd,
427 pkt_node->t_flags2,
428 pkt_node->snd_wnd,
429 pkt_node->rcv_wnd,
430 pkt_node->snd_scale,
431 pkt_node->rcv_scale,
432 pkt_node->conn_state,
433 pkt_node->mss,
434 pkt_node->srtt,
435 pkt_node->sack_enabled,
436 pkt_node->t_flags,
437 pkt_node->rto,
438 pkt_node->snd_buf_hiwater,
439 pkt_node->snd_buf_cc,
440 pkt_node->rcv_buf_hiwater,
441 pkt_node->rcv_buf_cc,
442 pkt_node->sent_inflight_bytes,
443 pkt_node->t_segqlen,
444 pkt_node->flowid,
445 pkt_node->flowtype);
446
447 alq_post_flags(siftr_alq, log_buf, 0);
448 }
449
450 static void
siftr_pkt_manager_thread(void * arg)451 siftr_pkt_manager_thread(void *arg)
452 {
453 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue =
454 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue);
455 struct pkt_node *pkt_node, *pkt_node_temp;
456 uint8_t draining;
457
458 draining = 2;
459
460 mtx_lock(&siftr_pkt_mgr_mtx);
461
462 /* draining == 0 when queue has been flushed and it's safe to exit. */
463 while (draining) {
464 /*
465 * Sleep until we are signalled to wake because thread has
466 * been told to exit or until 1 tick has passed.
467 */
468 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait",
469 1);
470
471 /* Gain exclusive access to the pkt_node queue. */
472 mtx_lock(&siftr_pkt_queue_mtx);
473
474 /*
475 * Move pkt_queue to tmp_pkt_queue, which leaves
476 * pkt_queue empty and ready to receive more pkt_nodes.
477 */
478 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue);
479
480 /*
481 * We've finished making changes to the list. Unlock it
482 * so the pfil hooks can continue queuing pkt_nodes.
483 */
484 mtx_unlock(&siftr_pkt_queue_mtx);
485
486 /*
487 * We can't hold a mutex whilst calling siftr_process_pkt
488 * because ALQ might sleep waiting for buffer space.
489 */
490 mtx_unlock(&siftr_pkt_mgr_mtx);
491
492 /* Flush all pkt_nodes to the log file. */
493 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes,
494 pkt_node_temp) {
495 siftr_process_pkt(pkt_node);
496 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes);
497 free(pkt_node, M_SIFTR_PKTNODE);
498 }
499
500 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue),
501 ("SIFTR tmp_pkt_queue not empty after flush"));
502
503 mtx_lock(&siftr_pkt_mgr_mtx);
504
505 /*
506 * If siftr_exit_pkt_manager_thread gets set during the window
507 * where we are draining the tmp_pkt_queue above, there might
508 * still be pkts in pkt_queue that need to be drained.
509 * Allow one further iteration to occur after
510 * siftr_exit_pkt_manager_thread has been set to ensure
511 * pkt_queue is completely empty before we kill the thread.
512 *
513 * siftr_exit_pkt_manager_thread is set only after the pfil
514 * hooks have been removed, so only 1 extra iteration
515 * is needed to drain the queue.
516 */
517 if (siftr_exit_pkt_manager_thread)
518 draining--;
519 }
520
521 mtx_unlock(&siftr_pkt_mgr_mtx);
522
523 /* Calls wakeup on this thread's struct thread ptr. */
524 kthread_exit();
525 }
526
527 /*
528 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that
529 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return.
530 * Return value >0 means the caller should skip processing this mbuf.
531 */
532 static inline int
siftr_chkreinject(struct mbuf * m,int dir,struct siftr_stats * ss)533 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss)
534 {
535 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL)
536 != NULL) {
537 if (dir == PFIL_IN)
538 ss->nskip_in_dejavu++;
539 else
540 ss->nskip_out_dejavu++;
541
542 return (1);
543 } else {
544 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR,
545 PACKET_TAG_SIFTR, 0, M_NOWAIT);
546 if (tag == NULL) {
547 if (dir == PFIL_IN)
548 ss->nskip_in_malloc++;
549 else
550 ss->nskip_out_malloc++;
551
552 return (1);
553 }
554
555 m_tag_prepend(m, tag);
556 }
557
558 return (0);
559 }
560
561 /*
562 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL
563 * otherwise.
564 */
565 static inline struct inpcb *
siftr_findinpcb(int ipver,struct ip * ip,struct mbuf * m,uint16_t sport,uint16_t dport,int dir,struct siftr_stats * ss)566 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport,
567 uint16_t dport, int dir, struct siftr_stats *ss)
568 {
569 struct inpcb *inp;
570
571 /* We need the tcbinfo lock. */
572 INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo);
573
574 if (dir == PFIL_IN)
575 inp = (ipver == INP_IPV4 ?
576 in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst,
577 dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
578 :
579 #ifdef SIFTR_IPV6
580 in6_pcblookup(&V_tcbinfo,
581 &((struct ip6_hdr *)ip)->ip6_src, sport,
582 &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB,
583 m->m_pkthdr.rcvif)
584 #else
585 NULL
586 #endif
587 );
588
589 else
590 inp = (ipver == INP_IPV4 ?
591 in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src,
592 sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
593 :
594 #ifdef SIFTR_IPV6
595 in6_pcblookup(&V_tcbinfo,
596 &((struct ip6_hdr *)ip)->ip6_dst, dport,
597 &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB,
598 m->m_pkthdr.rcvif)
599 #else
600 NULL
601 #endif
602 );
603
604 /* If we can't find the inpcb, bail. */
605 if (inp == NULL) {
606 if (dir == PFIL_IN)
607 ss->nskip_in_inpcb++;
608 else
609 ss->nskip_out_inpcb++;
610 }
611
612 return (inp);
613 }
614
615 static inline uint32_t
siftr_get_flowid(struct inpcb * inp,int ipver,uint32_t * phashtype)616 siftr_get_flowid(struct inpcb *inp, int ipver, uint32_t *phashtype)
617 {
618 if (inp->inp_flowid == 0) {
619 #ifdef SIFTR_IPV6
620 if (ipver == INP_IPV6) {
621 return fib6_calc_packet_hash(&inp->in6p_laddr,
622 &inp->in6p_faddr,
623 inp->inp_lport,
624 inp->inp_fport,
625 IPPROTO_TCP,
626 phashtype);
627 } else
628 #endif
629 {
630 return fib4_calc_packet_hash(inp->inp_laddr,
631 inp->inp_faddr,
632 inp->inp_lport,
633 inp->inp_fport,
634 IPPROTO_TCP,
635 phashtype);
636 }
637 } else {
638 *phashtype = inp->inp_flowtype;
639 return inp->inp_flowid;
640 }
641 }
642
643 static inline void
siftr_siftdata(struct pkt_node * pn,struct inpcb * inp,struct tcpcb * tp,int ipver,int dir,int inp_locally_locked)644 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp,
645 int ipver, int dir, int inp_locally_locked)
646 {
647 pn->ipver = ipver;
648 pn->lport = inp->inp_lport;
649 pn->fport = inp->inp_fport;
650 pn->laddr = inp->inp_inc.inc_ie.ie_dependladdr;
651 pn->faddr = inp->inp_inc.inc_ie.ie_dependfaddr;
652 pn->snd_cwnd = tp->snd_cwnd;
653 pn->snd_wnd = tp->snd_wnd;
654 pn->rcv_wnd = tp->rcv_wnd;
655 pn->t_flags2 = tp->t_flags2;
656 pn->snd_ssthresh = tp->snd_ssthresh;
657 pn->snd_scale = tp->snd_scale;
658 pn->rcv_scale = tp->rcv_scale;
659 pn->conn_state = tp->t_state;
660 pn->mss = tp->t_maxseg;
661 pn->srtt = ((uint64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
662 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0;
663 pn->t_flags = tp->t_flags;
664 pn->rto = tp->t_rxtcur * tick;
665 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat;
666 pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd);
667 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat;
668 pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv);
669 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una;
670 pn->t_segqlen = tp->t_segqlen;
671
672 /* We've finished accessing the tcb so release the lock. */
673 if (inp_locally_locked)
674 INP_RUNLOCK(inp);
675
676 pn->direction = (dir == PFIL_IN ? DIR_IN : DIR_OUT);
677
678 /*
679 * Significantly more accurate than using getmicrotime(), but slower!
680 * Gives true microsecond resolution at the expense of a hit to
681 * maximum pps throughput processing when SIFTR is loaded and enabled.
682 */
683 microtime(&pn->tval);
684 TCP_PROBE1(siftr, pn);
685 }
686
687 /*
688 * pfil hook that is called for each IPv4 packet making its way through the
689 * stack in either direction.
690 * The pfil subsystem holds a non-sleepable mutex somewhere when
691 * calling our hook function, so we can't sleep at all.
692 * It's very important to use the M_NOWAIT flag with all function calls
693 * that support it so that they won't sleep, otherwise you get a panic.
694 */
695 static pfil_return_t
siftr_chkpkt(struct mbuf ** m,struct ifnet * ifp,int flags,void * ruleset __unused,struct inpcb * inp)696 siftr_chkpkt(struct mbuf **m, struct ifnet *ifp, int flags,
697 void *ruleset __unused, struct inpcb *inp)
698 {
699 struct pkt_node *pn;
700 struct ip *ip;
701 struct tcphdr *th;
702 struct tcpcb *tp;
703 struct siftr_stats *ss;
704 unsigned int ip_hl;
705 int inp_locally_locked, dir;
706 uint32_t hash_id, hash_type;
707 struct listhead *counter_list;
708 struct flow_hash_node *hash_node;
709
710 inp_locally_locked = 0;
711 dir = PFIL_DIR(flags);
712 ss = DPCPU_PTR(ss);
713
714 /*
715 * m_pullup is not required here because ip_{input|output}
716 * already do the heavy lifting for us.
717 */
718
719 ip = mtod(*m, struct ip *);
720
721 /* Only continue processing if the packet is TCP. */
722 if (ip->ip_p != IPPROTO_TCP)
723 goto ret;
724
725 /*
726 * Create a tcphdr struct starting at the correct offset
727 * in the IP packet. ip->ip_hl gives the ip header length
728 * in 4-byte words, so multiply it to get the size in bytes.
729 */
730 ip_hl = (ip->ip_hl << 2);
731 th = (struct tcphdr *)((caddr_t)ip + ip_hl);
732
733 /*
734 * Only pkts selected by the tcp port filter
735 * can be inserted into the pkt_queue
736 */
737 if ((siftr_port_filter != 0) &&
738 (siftr_port_filter != ntohs(th->th_sport)) &&
739 (siftr_port_filter != ntohs(th->th_dport))) {
740 goto ret;
741 }
742
743 /*
744 * If a kernel subsystem reinjects packets into the stack, our pfil
745 * hook will be called multiple times for the same packet.
746 * Make sure we only process unique packets.
747 */
748 if (siftr_chkreinject(*m, dir, ss))
749 goto ret;
750
751 if (dir == PFIL_IN)
752 ss->n_in++;
753 else
754 ss->n_out++;
755
756 /*
757 * If the pfil hooks don't provide a pointer to the
758 * inpcb, we need to find it ourselves and lock it.
759 */
760 if (!inp) {
761 /* Find the corresponding inpcb for this pkt. */
762 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport,
763 th->th_dport, dir, ss);
764
765 if (inp == NULL)
766 goto ret;
767 else
768 inp_locally_locked = 1;
769 }
770
771 INP_LOCK_ASSERT(inp);
772
773 /* Find the TCP control block that corresponds with this packet */
774 tp = intotcpcb(inp);
775
776 /*
777 * If we can't find the TCP control block (happens occasionaly for a
778 * packet sent during the shutdown phase of a TCP connection), or the
779 * TCP control block has not initialized (happens during TCPS_SYN_SENT),
780 * bail.
781 */
782 if (tp == NULL || tp->t_state < TCPS_ESTABLISHED) {
783 if (dir == PFIL_IN)
784 ss->nskip_in_tcpcb++;
785 else
786 ss->nskip_out_tcpcb++;
787
788 goto inp_unlock;
789 }
790
791 hash_id = siftr_get_flowid(inp, INP_IPV4, &hash_type);
792 counter_list = counter_hash + (hash_id & siftr_hashmask);
793 hash_node = siftr_find_flow(counter_list, hash_id);
794
795 /* If this flow hasn't been seen before, we create a new entry. */
796 if (hash_node == NULL) {
797 struct flow_info info;
798
799 inet_ntoa_r(inp->inp_laddr, info.laddr);
800 inet_ntoa_r(inp->inp_faddr, info.faddr);
801 info.lport = ntohs(inp->inp_lport);
802 info.fport = ntohs(inp->inp_fport);
803 info.key = hash_id;
804
805 hash_node = siftr_new_hash_node(info, dir, ss);
806 }
807
808 if (hash_node == NULL) {
809 goto inp_unlock;
810 }
811
812 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
813
814 if (pn == NULL) {
815 if (dir == PFIL_IN)
816 ss->nskip_in_malloc++;
817 else
818 ss->nskip_out_malloc++;
819
820 goto inp_unlock;
821 }
822
823 pn->flowid = hash_id;
824 pn->flowtype = hash_type;
825
826 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked);
827
828 mtx_lock(&siftr_pkt_queue_mtx);
829 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
830 mtx_unlock(&siftr_pkt_queue_mtx);
831 goto ret;
832
833 inp_unlock:
834 if (inp_locally_locked)
835 INP_RUNLOCK(inp);
836
837 ret:
838 return (PFIL_PASS);
839 }
840
841 #ifdef SIFTR_IPV6
842 static pfil_return_t
siftr_chkpkt6(struct mbuf ** m,struct ifnet * ifp,int flags,void * ruleset __unused,struct inpcb * inp)843 siftr_chkpkt6(struct mbuf **m, struct ifnet *ifp, int flags,
844 void *ruleset __unused, struct inpcb *inp)
845 {
846 struct pkt_node *pn;
847 struct ip6_hdr *ip6;
848 struct tcphdr *th;
849 struct tcpcb *tp;
850 struct siftr_stats *ss;
851 unsigned int ip6_hl;
852 int inp_locally_locked, dir;
853 uint32_t hash_id, hash_type;
854 struct listhead *counter_list;
855 struct flow_hash_node *hash_node;
856
857 inp_locally_locked = 0;
858 dir = PFIL_DIR(flags);
859 ss = DPCPU_PTR(ss);
860
861 /*
862 * m_pullup is not required here because ip6_{input|output}
863 * already do the heavy lifting for us.
864 */
865
866 ip6 = mtod(*m, struct ip6_hdr *);
867
868 /*
869 * Only continue processing if the packet is TCP
870 * XXX: We should follow the next header fields
871 * as shown on Pg 6 RFC 2460, but right now we'll
872 * only check pkts that have no extension headers.
873 */
874 if (ip6->ip6_nxt != IPPROTO_TCP)
875 goto ret6;
876
877 /*
878 * Create a tcphdr struct starting at the correct offset
879 * in the ipv6 packet.
880 */
881 ip6_hl = sizeof(struct ip6_hdr);
882 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl);
883
884 /*
885 * Only pkts selected by the tcp port filter
886 * can be inserted into the pkt_queue
887 */
888 if ((siftr_port_filter != 0) &&
889 (siftr_port_filter != ntohs(th->th_sport)) &&
890 (siftr_port_filter != ntohs(th->th_dport))) {
891 goto ret6;
892 }
893
894 /*
895 * If a kernel subsystem reinjects packets into the stack, our pfil
896 * hook will be called multiple times for the same packet.
897 * Make sure we only process unique packets.
898 */
899 if (siftr_chkreinject(*m, dir, ss))
900 goto ret6;
901
902 if (dir == PFIL_IN)
903 ss->n_in++;
904 else
905 ss->n_out++;
906
907 /*
908 * For inbound packets, the pfil hooks don't provide a pointer to the
909 * inpcb, so we need to find it ourselves and lock it.
910 */
911 if (!inp) {
912 /* Find the corresponding inpcb for this pkt. */
913 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m,
914 th->th_sport, th->th_dport, dir, ss);
915
916 if (inp == NULL)
917 goto ret6;
918 else
919 inp_locally_locked = 1;
920 }
921
922 /* Find the TCP control block that corresponds with this packet. */
923 tp = intotcpcb(inp);
924
925 /*
926 * If we can't find the TCP control block (happens occasionaly for a
927 * packet sent during the shutdown phase of a TCP connection), or the
928 * TCP control block has not initialized (happens during TCPS_SYN_SENT),
929 * bail.
930 */
931 if (tp == NULL || tp->t_state < TCPS_ESTABLISHED) {
932 if (dir == PFIL_IN)
933 ss->nskip_in_tcpcb++;
934 else
935 ss->nskip_out_tcpcb++;
936
937 goto inp_unlock6;
938 }
939
940 hash_id = siftr_get_flowid(inp, INP_IPV6, &hash_type);
941 counter_list = counter_hash + (hash_id & siftr_hashmask);
942 hash_node = siftr_find_flow(counter_list, hash_id);
943
944 /* If this flow hasn't been seen before, we create a new entry. */
945 if (!hash_node) {
946 struct flow_info info;
947
948 ip6_sprintf(info.laddr, &inp->in6p_laddr);
949 ip6_sprintf(info.faddr, &inp->in6p_faddr);
950 info.lport = ntohs(inp->inp_lport);
951 info.fport = ntohs(inp->inp_fport);
952 info.key = hash_id;
953
954 hash_node = siftr_new_hash_node(info, dir, ss);
955 }
956
957 if (!hash_node) {
958 goto inp_unlock6;
959 }
960
961 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
962
963 if (pn == NULL) {
964 if (dir == PFIL_IN)
965 ss->nskip_in_malloc++;
966 else
967 ss->nskip_out_malloc++;
968
969 goto inp_unlock6;
970 }
971
972 pn->flowid = hash_id;
973 pn->flowtype = hash_type;
974
975 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked);
976
977 mtx_lock(&siftr_pkt_queue_mtx);
978 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
979 mtx_unlock(&siftr_pkt_queue_mtx);
980 goto ret6;
981
982 inp_unlock6:
983 if (inp_locally_locked)
984 INP_RUNLOCK(inp);
985
986 ret6:
987 return (PFIL_PASS);
988 }
989 #endif /* #ifdef SIFTR_IPV6 */
990
991 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet_hook);
992 #define V_siftr_inet_hook VNET(siftr_inet_hook)
993 #ifdef SIFTR_IPV6
994 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet6_hook);
995 #define V_siftr_inet6_hook VNET(siftr_inet6_hook)
996 #endif
997 static int
siftr_pfil(int action)998 siftr_pfil(int action)
999 {
1000 struct pfil_hook_args pha = {
1001 .pa_version = PFIL_VERSION,
1002 .pa_flags = PFIL_IN | PFIL_OUT,
1003 .pa_modname = "siftr",
1004 .pa_rulname = "default",
1005 };
1006 struct pfil_link_args pla = {
1007 .pa_version = PFIL_VERSION,
1008 .pa_flags = PFIL_IN | PFIL_OUT | PFIL_HEADPTR | PFIL_HOOKPTR,
1009 };
1010
1011 VNET_ITERATOR_DECL(vnet_iter);
1012
1013 VNET_LIST_RLOCK();
1014 VNET_FOREACH(vnet_iter) {
1015 CURVNET_SET(vnet_iter);
1016
1017 if (action == HOOK) {
1018 pha.pa_mbuf_chk = siftr_chkpkt;
1019 pha.pa_type = PFIL_TYPE_IP4;
1020 V_siftr_inet_hook = pfil_add_hook(&pha);
1021 pla.pa_hook = V_siftr_inet_hook;
1022 pla.pa_head = V_inet_pfil_head;
1023 (void)pfil_link(&pla);
1024 #ifdef SIFTR_IPV6
1025 pha.pa_mbuf_chk = siftr_chkpkt6;
1026 pha.pa_type = PFIL_TYPE_IP6;
1027 V_siftr_inet6_hook = pfil_add_hook(&pha);
1028 pla.pa_hook = V_siftr_inet6_hook;
1029 pla.pa_head = V_inet6_pfil_head;
1030 (void)pfil_link(&pla);
1031 #endif
1032 } else if (action == UNHOOK) {
1033 pfil_remove_hook(V_siftr_inet_hook);
1034 #ifdef SIFTR_IPV6
1035 pfil_remove_hook(V_siftr_inet6_hook);
1036 #endif
1037 }
1038 CURVNET_RESTORE();
1039 }
1040 VNET_LIST_RUNLOCK();
1041
1042 return (0);
1043 }
1044
1045 static int
siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS)1046 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS)
1047 {
1048 struct alq *new_alq;
1049 int error;
1050
1051 error = sysctl_handle_string(oidp, arg1, arg2, req);
1052
1053 /* Check for error or same filename */
1054 if (error != 0 || req->newptr == NULL ||
1055 strncmp(siftr_logfile, arg1, arg2) == 0)
1056 goto done;
1057
1058 /* file name changed */
1059 error = alq_open(&new_alq, arg1, curthread->td_ucred,
1060 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1061 if (error != 0)
1062 goto done;
1063
1064 /*
1065 * If disabled, siftr_alq == NULL so we simply close
1066 * the alq as we've proved it can be opened.
1067 * If enabled, close the existing alq and switch the old
1068 * for the new.
1069 */
1070 if (siftr_alq == NULL) {
1071 alq_close(new_alq);
1072 } else {
1073 alq_close(siftr_alq);
1074 siftr_alq = new_alq;
1075 }
1076
1077 /* Update filename upon success */
1078 strlcpy(siftr_logfile, arg1, arg2);
1079 done:
1080 return (error);
1081 }
1082
1083 static int
siftr_manage_ops(uint8_t action)1084 siftr_manage_ops(uint8_t action)
1085 {
1086 struct siftr_stats totalss;
1087 struct timeval tval;
1088 struct flow_hash_node *counter, *tmp_counter;
1089 struct sbuf *s;
1090 int i, error;
1091 uint32_t bytes_to_write, total_skipped_pkts;
1092
1093 error = 0;
1094 total_skipped_pkts = 0;
1095
1096 /* Init an autosizing sbuf that initially holds 200 chars. */
1097 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL)
1098 return (-1);
1099
1100 if (action == SIFTR_ENABLE && siftr_pkt_manager_thr == NULL) {
1101 /*
1102 * Create our alq
1103 * XXX: We should abort if alq_open fails!
1104 */
1105 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred,
1106 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1107
1108 STAILQ_INIT(&pkt_queue);
1109
1110 DPCPU_ZERO(ss);
1111
1112 siftr_exit_pkt_manager_thread = 0;
1113
1114 kthread_add(&siftr_pkt_manager_thread, NULL, NULL,
1115 &siftr_pkt_manager_thr, RFNOWAIT, 0,
1116 "siftr_pkt_manager_thr");
1117
1118 siftr_pfil(HOOK);
1119
1120 microtime(&tval);
1121
1122 sbuf_printf(s,
1123 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t"
1124 "siftrver=%s\tsysname=%s\tsysver=%u\tipmode=%u\n",
1125 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR,
1126 SYS_NAME, __FreeBSD_version, SIFTR_IPMODE);
1127
1128 sbuf_finish(s);
1129 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK);
1130
1131 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) {
1132 /*
1133 * Remove the pfil hook functions. All threads currently in
1134 * the hook functions are allowed to exit before siftr_pfil()
1135 * returns.
1136 */
1137 siftr_pfil(UNHOOK);
1138
1139 /* This will block until the pkt manager thread unlocks it. */
1140 mtx_lock(&siftr_pkt_mgr_mtx);
1141
1142 /* Tell the pkt manager thread that it should exit now. */
1143 siftr_exit_pkt_manager_thread = 1;
1144
1145 /*
1146 * Wake the pkt_manager thread so it realises that
1147 * siftr_exit_pkt_manager_thread == 1 and exits gracefully.
1148 * The wakeup won't be delivered until we unlock
1149 * siftr_pkt_mgr_mtx so this isn't racy.
1150 */
1151 wakeup(&wait_for_pkt);
1152
1153 /* Wait for the pkt_manager thread to exit. */
1154 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT,
1155 "thrwait", 0);
1156
1157 siftr_pkt_manager_thr = NULL;
1158 mtx_unlock(&siftr_pkt_mgr_mtx);
1159
1160 totalss.n_in = DPCPU_VARSUM(ss, n_in);
1161 totalss.n_out = DPCPU_VARSUM(ss, n_out);
1162 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc);
1163 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc);
1164 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb);
1165 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb);
1166 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb);
1167 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb);
1168
1169 total_skipped_pkts = totalss.nskip_in_malloc +
1170 totalss.nskip_out_malloc + totalss.nskip_in_tcpcb +
1171 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb +
1172 totalss.nskip_out_inpcb;
1173
1174 microtime(&tval);
1175
1176 sbuf_printf(s,
1177 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t"
1178 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t"
1179 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t"
1180 "num_outbound_skipped_pkts_malloc=%u\t"
1181 "num_inbound_skipped_pkts_tcpcb=%u\t"
1182 "num_outbound_skipped_pkts_tcpcb=%u\t"
1183 "num_inbound_skipped_pkts_inpcb=%u\t"
1184 "num_outbound_skipped_pkts_inpcb=%u\t"
1185 "total_skipped_tcp_pkts=%u\tflow_list=",
1186 (intmax_t)tval.tv_sec,
1187 tval.tv_usec,
1188 (uintmax_t)totalss.n_in,
1189 (uintmax_t)totalss.n_out,
1190 (uintmax_t)(totalss.n_in + totalss.n_out),
1191 totalss.nskip_in_malloc,
1192 totalss.nskip_out_malloc,
1193 totalss.nskip_in_tcpcb,
1194 totalss.nskip_out_tcpcb,
1195 totalss.nskip_in_inpcb,
1196 totalss.nskip_out_inpcb,
1197 total_skipped_pkts);
1198
1199 /*
1200 * Iterate over the flow hash, printing a summary of each
1201 * flow seen and freeing any malloc'd memory.
1202 * The hash consists of an array of LISTs (man 3 queue).
1203 */
1204 for (i = 0; i <= siftr_hashmask; i++) {
1205 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes,
1206 tmp_counter) {
1207 sbuf_printf(s, "%s;%hu-%s;%hu,",
1208 counter->const_info.laddr,
1209 counter->const_info.lport,
1210 counter->const_info.faddr,
1211 counter->const_info.fport);
1212
1213 free(counter, M_SIFTR_HASHNODE);
1214 }
1215
1216 LIST_INIT(counter_hash + i);
1217 }
1218
1219 sbuf_printf(s, "\n");
1220 sbuf_finish(s);
1221
1222 i = 0;
1223 do {
1224 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i);
1225 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK);
1226 i += bytes_to_write;
1227 } while (i < sbuf_len(s));
1228
1229 alq_close(siftr_alq);
1230 siftr_alq = NULL;
1231 } else
1232 error = EINVAL;
1233
1234 sbuf_delete(s);
1235
1236 /*
1237 * XXX: Should be using ret to check if any functions fail
1238 * and set error appropriately
1239 */
1240
1241 return (error);
1242 }
1243
1244 static int
siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS)1245 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS)
1246 {
1247 int error;
1248 uint32_t new;
1249
1250 new = siftr_enabled;
1251 error = sysctl_handle_int(oidp, &new, 0, req);
1252 if (error == 0 && req->newptr != NULL) {
1253 if (new > 1)
1254 return (EINVAL);
1255 else if (new != siftr_enabled) {
1256 if ((error = siftr_manage_ops(new)) == 0) {
1257 siftr_enabled = new;
1258 } else {
1259 siftr_manage_ops(SIFTR_DISABLE);
1260 }
1261 }
1262 }
1263
1264 return (error);
1265 }
1266
1267 static void
siftr_shutdown_handler(void * arg,int howto)1268 siftr_shutdown_handler(void *arg, int howto)
1269 {
1270 if ((howto & RB_NOSYNC) != 0 || SCHEDULER_STOPPED())
1271 return;
1272
1273 if (siftr_enabled == 1) {
1274 siftr_manage_ops(SIFTR_DISABLE);
1275 }
1276 }
1277
1278 /*
1279 * Module is being unloaded or machine is shutting down. Take care of cleanup.
1280 */
1281 static int
deinit_siftr(void)1282 deinit_siftr(void)
1283 {
1284 /* Cleanup. */
1285 EVENTHANDLER_DEREGISTER(shutdown_pre_sync, siftr_shutdown_tag);
1286 siftr_manage_ops(SIFTR_DISABLE);
1287 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask);
1288 mtx_destroy(&siftr_pkt_queue_mtx);
1289 mtx_destroy(&siftr_pkt_mgr_mtx);
1290
1291 return (0);
1292 }
1293
1294 /*
1295 * Module has just been loaded into the kernel.
1296 */
1297 static int
init_siftr(void)1298 init_siftr(void)
1299 {
1300 siftr_shutdown_tag = EVENTHANDLER_REGISTER(shutdown_pre_sync,
1301 siftr_shutdown_handler, NULL, SHUTDOWN_PRI_FIRST);
1302
1303 /* Initialise our flow counter hash table. */
1304 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR,
1305 &siftr_hashmask);
1306
1307 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF);
1308 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF);
1309
1310 /* Print message to the user's current terminal. */
1311 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n"
1312 " http://caia.swin.edu.au/urp/newtcp\n\n",
1313 MODVERSION_STR);
1314
1315 return (0);
1316 }
1317
1318 /*
1319 * This is the function that is called to load and unload the module.
1320 * When the module is loaded, this function is called once with
1321 * "what" == MOD_LOAD
1322 * When the module is unloaded, this function is called twice with
1323 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second
1324 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command,
1325 * this function is called once with "what" = MOD_SHUTDOWN
1326 * When the system is shut down, the handler isn't called until the very end
1327 * of the shutdown sequence i.e. after the disks have been synced.
1328 */
1329 static int
siftr_load_handler(module_t mod,int what,void * arg)1330 siftr_load_handler(module_t mod, int what, void *arg)
1331 {
1332 int ret;
1333
1334 switch (what) {
1335 case MOD_LOAD:
1336 ret = init_siftr();
1337 break;
1338
1339 case MOD_QUIESCE:
1340 case MOD_SHUTDOWN:
1341 ret = deinit_siftr();
1342 break;
1343
1344 case MOD_UNLOAD:
1345 ret = 0;
1346 break;
1347
1348 default:
1349 ret = EINVAL;
1350 break;
1351 }
1352
1353 return (ret);
1354 }
1355
1356 static moduledata_t siftr_mod = {
1357 .name = "siftr",
1358 .evhand = siftr_load_handler,
1359 };
1360
1361 /*
1362 * Param 1: name of the kernel module
1363 * Param 2: moduledata_t struct containing info about the kernel module
1364 * and the execution entry point for the module
1365 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h
1366 * Defines the module initialisation order
1367 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h
1368 * Defines the initialisation order of this kld relative to others
1369 * within the same subsystem as defined by param 3
1370 */
1371 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY);
1372 MODULE_DEPEND(siftr, alq, 1, 1, 1);
1373 MODULE_VERSION(siftr, MODVERSION);
1374