Merge branch 'master' of git://chlamydia.fs.ei.tum.de/dragonfly
[dragonfly.git] / sys / netinet / ip_flow.c
blob1e4ca1ea32a46ffa7f1fe043a77bc28d2536355b
1 /*-
2 * Copyright (c) 1998 The NetBSD Foundation, Inc.
3 * All rights reserved.
5 * This code is derived from software contributed to The NetBSD Foundation
6 * by the 3am Software Foundry ("3am"). It was developed by Matt Thomas.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the NetBSD
19 * Foundation, Inc. and its contributors.
20 * 4. Neither the name of The NetBSD Foundation nor the names of its
21 * contributors may be used to endorse or promote products derived
22 * from this software without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
26 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
27 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
28 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
36 * $FreeBSD: src/sys/netinet/ip_flow.c,v 1.9.2.2 2001/11/04 17:35:31 luigi Exp $
37 * $DragonFly: src/sys/netinet/ip_flow.c,v 1.27 2008/10/28 07:09:26 sephe Exp $
40 #include <sys/param.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/mbuf.h>
44 #include <sys/protosw.h>
45 #include <sys/socket.h>
46 #include <sys/sysctl.h>
47 #include <sys/thread2.h>
48 #include <sys/in_cksum.h>
50 #include <machine/smp.h>
52 #include <net/if.h>
53 #include <net/if_var.h>
54 #include <net/route.h>
55 #include <net/netisr.h>
56 #include <net/netmsg2.h>
58 #include <netinet/in.h>
59 #include <netinet/ip.h>
60 #include <netinet/in_var.h>
61 #include <netinet/ip_var.h>
62 #include <netinet/ip_flow.h>
64 #define IPFLOW_TIMER (5 * PR_SLOWHZ)
65 #define IPFLOW_HASHBITS 6 /* should not be a multiple of 8 */
66 #define IPFLOW_HASHSIZE (1 << IPFLOW_HASHBITS)
67 #define IPFLOW_MAX 256
69 #define IPFLOW_RTENTRY_ISDOWN(rt) \
70 (((rt)->rt_flags & RTF_UP) == 0 || \
71 ((rt)->rt_ifp->if_flags & IFF_UP) == 0)
73 struct netmsg_ipfaddr {
74 struct netmsg ipf_nmsg;
75 struct in_addr ipf_addr;
78 struct ipflow {
79 LIST_ENTRY(ipflow) ipf_hash; /* next ipflow in hash bucket */
80 LIST_ENTRY(ipflow) ipf_list; /* next ipflow in list */
82 struct in_addr ipf_dst; /* destination address */
83 struct in_addr ipf_src; /* source address */
84 uint8_t ipf_tos; /* type-of-service */
86 uint8_t ipf_flags; /* see IPFLOW_FLAG_ */
87 uint8_t ipf_pad[2]; /* explicit pad */
88 int ipf_refcnt; /* reference count */
90 struct route ipf_ro; /* associated route entry */
91 u_long ipf_uses; /* number of uses in this period */
93 int ipf_timer; /* remaining lifetime of this entry */
94 u_long ipf_dropped; /* ENOBUFS returned by if_output */
95 u_long ipf_errors; /* other errors returned by if_output */
96 u_long ipf_last_uses; /* number of uses in last period */
98 LIST_HEAD(ipflowhead, ipflow);
100 #define IPFLOW_FLAG_ONLIST 0x1
102 #define ipflow_inuse ipflow_inuse_pcpu[mycpuid]
103 #define ipflowtable ipflowtable_pcpu[mycpuid]
104 #define ipflowlist ipflowlist_pcpu[mycpuid]
106 static struct ipflowhead ipflowtable_pcpu[MAXCPU][IPFLOW_HASHSIZE];
107 static struct ipflowhead ipflowlist_pcpu[MAXCPU];
108 static int ipflow_inuse_pcpu[MAXCPU];
109 static struct netmsg ipflow_timo_netmsgs[MAXCPU];
110 static int ipflow_active = 0;
112 #define IPFLOW_REFCNT_INIT 1
114 /* ipflow is alive and active */
115 #define IPFLOW_IS_ACTIVE(ipf) ((ipf)->ipf_refcnt > IPFLOW_REFCNT_INIT)
116 /* ipflow is alive but not active */
117 #define IPFLOW_NOT_ACTIVE(ipf) ((ipf)->ipf_refcnt == IPFLOW_REFCNT_INIT)
119 #define IPFLOW_REF(ipf) \
120 do { \
121 KKASSERT((ipf)->ipf_refcnt > 0); \
122 (ipf)->ipf_refcnt++; \
123 } while (0)
125 #define IPFLOW_FREE(ipf) \
126 do { \
127 KKASSERT((ipf)->ipf_refcnt > 0); \
128 (ipf)->ipf_refcnt--; \
129 if ((ipf)->ipf_refcnt == 0) \
130 ipflow_free((ipf)); \
131 } while (0)
133 #define IPFLOW_INSERT(bucket, ipf) \
134 do { \
135 KKASSERT(((ipf)->ipf_flags & IPFLOW_FLAG_ONLIST) == 0); \
136 (ipf)->ipf_flags |= IPFLOW_FLAG_ONLIST; \
137 LIST_INSERT_HEAD((bucket), (ipf), ipf_hash); \
138 LIST_INSERT_HEAD(&ipflowlist, (ipf), ipf_list); \
139 } while (0)
141 #define IPFLOW_REMOVE(ipf) \
142 do { \
143 KKASSERT((ipf)->ipf_flags & IPFLOW_FLAG_ONLIST); \
144 (ipf)->ipf_flags &= ~IPFLOW_FLAG_ONLIST; \
145 LIST_REMOVE((ipf), ipf_hash); \
146 LIST_REMOVE((ipf), ipf_list); \
147 } while (0)
149 SYSCTL_NODE(_net_inet_ip, OID_AUTO, ipflow, CTLFLAG_RW, 0, "ip flow");
150 SYSCTL_INT(_net_inet_ip, IPCTL_FASTFORWARDING, fastforwarding, CTLFLAG_RW,
151 &ipflow_active, 0, "Enable flow-based IP forwarding");
153 static MALLOC_DEFINE(M_IPFLOW, "ip_flow", "IP flow");
155 static void ipflow_free(struct ipflow *);
157 static unsigned
158 ipflow_hash(struct in_addr dst, struct in_addr src, unsigned tos)
160 unsigned hash = tos;
161 int idx;
163 for (idx = 0; idx < 32; idx += IPFLOW_HASHBITS)
164 hash += (dst.s_addr >> (32 - idx)) + (src.s_addr >> idx);
165 return hash & (IPFLOW_HASHSIZE-1);
168 static struct ipflow *
169 ipflow_lookup(const struct ip *ip)
171 unsigned hash;
172 struct ipflow *ipf;
174 hash = ipflow_hash(ip->ip_dst, ip->ip_src, ip->ip_tos);
175 LIST_FOREACH(ipf, &ipflowtable[hash], ipf_hash) {
176 if (ip->ip_dst.s_addr == ipf->ipf_dst.s_addr &&
177 ip->ip_src.s_addr == ipf->ipf_src.s_addr &&
178 ip->ip_tos == ipf->ipf_tos)
179 break;
181 return ipf;
185 ipflow_fastforward(struct mbuf *m)
187 struct ip *ip;
188 struct ipflow *ipf;
189 struct rtentry *rt;
190 struct sockaddr *dst;
191 struct ifnet *ifp;
192 int error, iplen;
195 * Are we forwarding packets?
197 if (!ipforwarding || !ipflow_active)
198 return 0;
201 * Was packet received as a link-level multicast or broadcast?
202 * If so, don't try to fast forward..
204 if (m->m_flags & (M_BCAST | M_MCAST))
205 return 0;
207 /* length checks already done in ip_mport() */
208 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf"));
209 ip = mtod(m, struct ip *);
212 * IP header with no option and valid version
214 if (ip->ip_v != IPVERSION || ip->ip_hl != (sizeof(struct ip) >> 2))
215 return 0;
217 iplen = ntohs(ip->ip_len);
218 /* length checks already done in ip_mport() */
219 KASSERT(iplen >= sizeof(struct ip),
220 ("total length less then header length"));
221 KASSERT(m->m_pkthdr.len >= iplen, ("mbuf too short"));
224 * Find a flow.
226 ipf = ipflow_lookup(ip);
227 if (ipf == NULL)
228 return 0;
231 * Verify the IP header checksum.
233 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
234 if (!(m->m_pkthdr.csum_flags & CSUM_IP_VALID))
235 return 0;
236 } else {
237 /* Must compute it ourselves. */
238 if (in_cksum_hdr(ip) != 0)
239 return 0;
243 * Route and interface still up?
245 rt = ipf->ipf_ro.ro_rt;
246 if (IPFLOW_RTENTRY_ISDOWN(rt))
247 return 0;
248 ifp = rt->rt_ifp;
251 * Packet size OK? TTL?
253 if (m->m_pkthdr.len > ifp->if_mtu || ip->ip_ttl <= IPTTLDEC)
254 return 0;
257 * Clear any in-bound checksum flags for this packet.
259 m->m_pkthdr.csum_flags = 0;
262 * Everything checks out and so we can forward this packet.
263 * Modify the TTL and incrementally change the checksum.
265 * This method of adding the checksum works on either endian CPU.
266 * If htons() is inlined, all the arithmetic is folded; otherwise
267 * the htons()s are combined by CSE due to the __const__ attribute.
269 * Don't bother using HW checksumming here -- the incremental
270 * update is pretty fast.
272 ip->ip_ttl -= IPTTLDEC;
273 if (ip->ip_sum >= (uint16_t)~htons(IPTTLDEC << 8))
274 ip->ip_sum -= ~htons(IPTTLDEC << 8);
275 else
276 ip->ip_sum += htons(IPTTLDEC << 8);
279 * Trim the packet in case it's too long..
281 if (m->m_pkthdr.len > iplen) {
282 if (m->m_len == m->m_pkthdr.len) {
283 m->m_len = iplen;
284 m->m_pkthdr.len = iplen;
285 } else {
286 m_adj(m, iplen - m->m_pkthdr.len);
291 * Send the packet on its way. All we can get back is ENOBUFS
293 ipf->ipf_uses++;
294 ipf->ipf_timer = IPFLOW_TIMER;
296 if (rt->rt_flags & RTF_GATEWAY)
297 dst = rt->rt_gateway;
298 else
299 dst = &ipf->ipf_ro.ro_dst;
302 * Reference count this ipflow, before the possible blocking
303 * ifnet.if_output(), so this ipflow will not be changed or
304 * reaped behind our back.
306 IPFLOW_REF(ipf);
308 error = ifp->if_output(ifp, m, dst, rt);
309 if (error) {
310 if (error == ENOBUFS)
311 ipf->ipf_dropped++;
312 else
313 ipf->ipf_errors++;
316 IPFLOW_FREE(ipf);
317 return 1;
320 static void
321 ipflow_addstats(struct ipflow *ipf)
323 ipf->ipf_ro.ro_rt->rt_use += ipf->ipf_uses;
324 ipstat.ips_cantforward += ipf->ipf_errors + ipf->ipf_dropped;
325 ipstat.ips_total += ipf->ipf_uses;
326 ipstat.ips_forward += ipf->ipf_uses;
327 ipstat.ips_fastforward += ipf->ipf_uses;
330 static void
331 ipflow_free(struct ipflow *ipf)
333 KKASSERT(ipf->ipf_refcnt == 0);
334 KKASSERT((ipf->ipf_flags & IPFLOW_FLAG_ONLIST) == 0);
336 KKASSERT(ipflow_inuse > 0);
337 ipflow_inuse--;
339 ipflow_addstats(ipf);
340 RTFREE(ipf->ipf_ro.ro_rt);
341 kfree(ipf, M_IPFLOW);
344 static void
345 ipflow_reset(struct ipflow *ipf)
347 ipflow_addstats(ipf);
348 RTFREE(ipf->ipf_ro.ro_rt);
349 ipf->ipf_uses = ipf->ipf_last_uses = 0;
350 ipf->ipf_errors = ipf->ipf_dropped = 0;
353 static struct ipflow *
354 ipflow_reap(void)
356 struct ipflow *ipf, *maybe_ipf = NULL;
358 LIST_FOREACH(ipf, &ipflowlist, ipf_list) {
360 * Skip actively used ipflow
362 if (IPFLOW_IS_ACTIVE(ipf))
363 continue;
366 * If this no longer points to a valid route
367 * reclaim it.
369 if ((ipf->ipf_ro.ro_rt->rt_flags & RTF_UP) == 0)
370 goto done;
373 * choose the one that's been least recently used
374 * or has had the least uses in the last 1.5
375 * intervals.
377 if (maybe_ipf == NULL ||
378 ipf->ipf_timer < maybe_ipf->ipf_timer ||
379 (ipf->ipf_timer == maybe_ipf->ipf_timer &&
380 ipf->ipf_last_uses + ipf->ipf_uses <
381 maybe_ipf->ipf_last_uses + maybe_ipf->ipf_uses))
382 maybe_ipf = ipf;
384 if (maybe_ipf == NULL)
385 return NULL;
387 ipf = maybe_ipf;
388 done:
390 * Remove the entry from the flow table and reset its states
392 IPFLOW_REMOVE(ipf);
393 ipflow_reset(ipf);
394 return ipf;
397 static void
398 ipflow_timo_dispatch(struct netmsg *nmsg)
400 struct ipflow *ipf, *next_ipf;
402 crit_enter();
403 lwkt_replymsg(&nmsg->nm_lmsg, 0); /* reply ASAP */
404 crit_exit();
406 LIST_FOREACH_MUTABLE(ipf, &ipflowlist, ipf_list, next_ipf) {
407 if (--ipf->ipf_timer == 0) {
408 IPFLOW_REMOVE(ipf);
409 IPFLOW_FREE(ipf);
410 } else {
411 ipf->ipf_last_uses = ipf->ipf_uses;
412 ipf->ipf_ro.ro_rt->rt_use += ipf->ipf_uses;
413 ipstat.ips_total += ipf->ipf_uses;
414 ipstat.ips_forward += ipf->ipf_uses;
415 ipstat.ips_fastforward += ipf->ipf_uses;
416 ipf->ipf_uses = 0;
421 static void
422 ipflow_timo_ipi(void *arg __unused)
424 struct lwkt_msg *msg = &ipflow_timo_netmsgs[mycpuid].nm_lmsg;
426 crit_enter();
427 if (msg->ms_flags & MSGF_DONE)
428 lwkt_sendmsg(cpu_portfn(mycpuid), msg);
429 crit_exit();
432 void
433 ipflow_slowtimo(void)
435 #ifdef SMP
436 uint32_t mask = 0;
437 int i;
439 for (i = 0; i < ncpus; ++i) {
440 if (ipflow_inuse_pcpu[i])
441 mask |= 1 << i;
443 mask &= smp_active_mask;
444 if (mask != 0)
445 lwkt_send_ipiq_mask(mask, ipflow_timo_ipi, NULL);
446 #else
447 if (ipflow_inuse)
448 ipflow_timo_ipi(NULL);
449 #endif
452 void
453 ipflow_create(const struct route *ro, struct mbuf *m)
455 const struct ip *const ip = mtod(m, struct ip *);
456 struct ipflow *ipf;
457 unsigned hash;
460 * Don't create cache entries for ICMP messages.
462 if (!ipflow_active || ip->ip_p == IPPROTO_ICMP)
463 return;
466 * See if an existing flow struct exists. If so remove it from it's
467 * list and free the old route. If not, try to malloc a new one
468 * (if we aren't at our limit).
470 ipf = ipflow_lookup(ip);
471 if (ipf == NULL) {
472 if (ipflow_inuse == IPFLOW_MAX) {
473 ipf = ipflow_reap();
474 if (ipf == NULL)
475 return;
476 } else {
477 ipf = kmalloc(sizeof(*ipf), M_IPFLOW,
478 M_NOWAIT | M_ZERO);
479 if (ipf == NULL)
480 return;
481 ipf->ipf_refcnt = IPFLOW_REFCNT_INIT;
483 ipflow_inuse++;
485 } else {
486 if (IPFLOW_NOT_ACTIVE(ipf)) {
487 IPFLOW_REMOVE(ipf);
488 ipflow_reset(ipf);
489 } else {
490 /* This ipflow is being used; don't change it */
491 KKASSERT(IPFLOW_IS_ACTIVE(ipf));
492 return;
495 /* This ipflow should not be actively used */
496 KKASSERT(IPFLOW_NOT_ACTIVE(ipf));
499 * Fill in the updated information.
501 ipf->ipf_ro = *ro;
502 ro->ro_rt->rt_refcnt++;
503 ipf->ipf_dst = ip->ip_dst;
504 ipf->ipf_src = ip->ip_src;
505 ipf->ipf_tos = ip->ip_tos;
506 ipf->ipf_timer = IPFLOW_TIMER;
509 * Insert into the approriate bucket of the flow table.
511 hash = ipflow_hash(ip->ip_dst, ip->ip_src, ip->ip_tos);
512 IPFLOW_INSERT(&ipflowtable[hash], ipf);
515 void
516 ipflow_flush_oncpu(void)
518 struct ipflow *ipf;
520 while ((ipf = LIST_FIRST(&ipflowlist)) != NULL) {
521 IPFLOW_REMOVE(ipf);
522 IPFLOW_FREE(ipf);
526 static void
527 ipflow_ifaddr_handler(struct netmsg *nmsg)
529 struct netmsg_ipfaddr *amsg = (struct netmsg_ipfaddr *)nmsg;
530 struct ipflow *ipf, *next_ipf;
532 LIST_FOREACH_MUTABLE(ipf, &ipflowlist, ipf_list, next_ipf) {
533 if (ipf->ipf_dst.s_addr == amsg->ipf_addr.s_addr ||
534 ipf->ipf_src.s_addr == amsg->ipf_addr.s_addr) {
535 IPFLOW_REMOVE(ipf);
536 IPFLOW_FREE(ipf);
539 ifnet_forwardmsg(&nmsg->nm_lmsg, mycpuid + 1);
542 static void
543 ipflow_ifaddr(void *arg __unused, struct ifnet *ifp __unused,
544 enum ifaddr_event event, struct ifaddr *ifa)
546 struct netmsg_ipfaddr amsg;
548 if (ifa->ifa_addr->sa_family != AF_INET)
549 return;
551 /* Only add/change events need to be handled */
552 switch (event) {
553 case IFADDR_EVENT_ADD:
554 case IFADDR_EVENT_CHANGE:
555 break;
557 case IFADDR_EVENT_DELETE:
558 return;
561 netmsg_init(&amsg.ipf_nmsg, &curthread->td_msgport, MSGF_PRIORITY,
562 ipflow_ifaddr_handler);
563 amsg.ipf_addr = ifatoia(ifa)->ia_addr.sin_addr;
565 ifnet_domsg(&amsg.ipf_nmsg.nm_lmsg, 0);
568 static void
569 ipflow_init(void)
571 char oid_name[32];
572 int i;
574 for (i = 0; i < ncpus; ++i) {
575 netmsg_init(&ipflow_timo_netmsgs[i], &netisr_adone_rport,
576 MSGF_MPSAFE, ipflow_timo_dispatch);
578 ksnprintf(oid_name, sizeof(oid_name), "inuse%d", i);
580 SYSCTL_ADD_INT(NULL,
581 SYSCTL_STATIC_CHILDREN(_net_inet_ip_ipflow),
582 OID_AUTO, oid_name, CTLFLAG_RD, &ipflow_inuse_pcpu[i], 0,
583 "# of ip flow being used");
585 EVENTHANDLER_REGISTER(ifaddr_event, ipflow_ifaddr, NULL,
586 EVENTHANDLER_PRI_ANY);
588 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, ipflow_init, 0);