2 * Copyright (c) 1998 The NetBSD Foundation, Inc.
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
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 $
39 #include <sys/param.h>
40 #include <sys/kernel.h>
41 #include <sys/malloc.h>
43 #include <sys/protosw.h>
44 #include <sys/socket.h>
45 #include <sys/sysctl.h>
46 #include <sys/thread2.h>
47 #include <sys/in_cksum.h>
49 #include <machine/smp.h>
52 #include <net/if_var.h>
53 #include <net/route.h>
54 #include <net/netisr2.h>
55 #include <net/netmsg2.h>
57 #include <netinet/in.h>
58 #include <netinet/ip.h>
59 #include <netinet/in_var.h>
60 #include <netinet/ip_var.h>
61 #include <netinet/ip_flow.h>
63 #define IPFLOW_TIMEOUT_FREQ 2 /* 2/second */
64 #define IPFLOW_TIMEOUT (hz / IPFLOW_TIMEOUT_FREQ)
66 #define IPFLOW_TIMER (5 * IPFLOW_TIMEOUT_FREQ)
67 #define IPFLOW_HASHBITS 6 /* should not be a multiple of 8 */
68 #define IPFLOW_HASHSIZE (1 << IPFLOW_HASHBITS)
69 #define IPFLOW_MAX 256
71 #define IPFLOW_RTENTRY_ISDOWN(rt) \
72 (((rt)->rt_flags & RTF_UP) == 0 || \
73 ((rt)->rt_ifp->if_flags & IFF_UP) == 0)
75 struct netmsg_ipfaddr {
76 struct netmsg_base base;
77 struct in_addr ipf_addr;
81 LIST_ENTRY(ipflow) ipf_hash; /* next ipflow in hash bucket */
82 LIST_ENTRY(ipflow) ipf_list; /* next ipflow in list */
84 struct in_addr ipf_dst; /* destination address */
85 struct in_addr ipf_src; /* source address */
86 uint8_t ipf_tos; /* type-of-service */
88 uint8_t ipf_flags; /* see IPFLOW_FLAG_ */
89 uint8_t ipf_pad[2]; /* explicit pad */
90 int ipf_refcnt; /* reference count */
92 struct route ipf_ro; /* associated route entry */
93 u_long ipf_uses; /* number of uses in this period */
95 int ipf_timer; /* remaining lifetime of this entry */
96 u_long ipf_dropped; /* ENOBUFS returned by if_output */
97 u_long ipf_errors; /* other errors returned by if_output */
98 u_long ipf_last_uses; /* number of uses in last period */
100 LIST_HEAD(ipflowhead, ipflow);
102 #define IPFLOW_FLAG_ONLIST 0x1
105 struct ipflowhead ipf_table[IPFLOW_HASHSIZE];
106 struct ipflowhead ipf_list;
108 struct callout ipf_timeo;
109 struct netmsg_base ipf_timeo_netmsg;
112 static struct ipflow_pcpu *ipflow_pcpu_data;
114 #define ipflow_inuse ipflow_pcpu_data[mycpuid].ipf_inuse
115 #define ipflowtable ipflow_pcpu_data[mycpuid].ipf_table
116 #define ipflowlist ipflow_pcpu_data[mycpuid].ipf_list
118 static int ipflow_active = 0;
120 #define IPFLOW_REFCNT_INIT 1
122 /* ipflow is alive and active */
123 #define IPFLOW_IS_ACTIVE(ipf) ((ipf)->ipf_refcnt > IPFLOW_REFCNT_INIT)
124 /* ipflow is alive but not active */
125 #define IPFLOW_NOT_ACTIVE(ipf) ((ipf)->ipf_refcnt == IPFLOW_REFCNT_INIT)
127 #define IPFLOW_REF(ipf) \
129 KKASSERT((ipf)->ipf_refcnt > 0); \
130 (ipf)->ipf_refcnt++; \
133 #define IPFLOW_FREE(ipf) \
135 KKASSERT((ipf)->ipf_refcnt > 0); \
136 (ipf)->ipf_refcnt--; \
137 if ((ipf)->ipf_refcnt == 0) \
138 ipflow_free((ipf)); \
141 #define IPFLOW_INSERT(bucket, ipf) \
143 KKASSERT(((ipf)->ipf_flags & IPFLOW_FLAG_ONLIST) == 0); \
144 (ipf)->ipf_flags |= IPFLOW_FLAG_ONLIST; \
145 LIST_INSERT_HEAD((bucket), (ipf), ipf_hash); \
146 LIST_INSERT_HEAD(&ipflowlist, (ipf), ipf_list); \
149 #define IPFLOW_REMOVE(ipf) \
151 KKASSERT((ipf)->ipf_flags & IPFLOW_FLAG_ONLIST); \
152 (ipf)->ipf_flags &= ~IPFLOW_FLAG_ONLIST; \
153 LIST_REMOVE((ipf), ipf_hash); \
154 LIST_REMOVE((ipf), ipf_list); \
157 SYSCTL_NODE(_net_inet_ip, OID_AUTO, ipflow, CTLFLAG_RW, 0, "ip flow");
158 SYSCTL_INT(_net_inet_ip, IPCTL_FASTFORWARDING, fastforwarding, CTLFLAG_RW,
159 &ipflow_active, 0, "Enable flow-based IP forwarding");
161 static MALLOC_DEFINE(M_IPFLOW, "ip_flow", "IP flow");
163 static void ipflow_free(struct ipflow *);
164 static void ipflow_timeo(void *);
167 ipflow_hash(struct in_addr dst, struct in_addr src, unsigned tos)
169 unsigned hash = tos + src.s_addr;
172 for (idx = IPFLOW_HASHBITS; idx < 32; idx += IPFLOW_HASHBITS)
173 hash += (dst.s_addr >> (32 - idx)) + (src.s_addr >> idx);
174 return hash & (IPFLOW_HASHSIZE-1);
177 static struct ipflow *
178 ipflow_lookup(const struct ip *ip)
183 hash = ipflow_hash(ip->ip_dst, ip->ip_src, ip->ip_tos);
184 LIST_FOREACH(ipf, &ipflowtable[hash], ipf_hash) {
185 if (ip->ip_dst.s_addr == ipf->ipf_dst.s_addr &&
186 ip->ip_src.s_addr == ipf->ipf_src.s_addr &&
187 ip->ip_tos == ipf->ipf_tos)
194 ipflow_fastforward(struct mbuf *m)
199 struct sockaddr *dst;
203 ASSERT_NETISR_NCPUS(curthread, mycpuid);
206 * Are we forwarding packets?
208 if (!ipforwarding || !ipflow_active)
212 * Was packet received as a link-level multicast or broadcast?
213 * If so, don't try to fast forward..
215 if (m->m_flags & (M_BCAST | M_MCAST))
218 /* length checks already done in ip_hashfn() */
219 KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf"));
220 ip = mtod(m, struct ip *);
223 * IP header with no option and valid version
225 if (ip->ip_v != IPVERSION || ip->ip_hl != (sizeof(struct ip) >> 2))
228 iplen = ntohs(ip->ip_len);
229 /* length checks already done in ip_hashfn() */
230 KASSERT(iplen >= sizeof(struct ip),
231 ("total length less then header length"));
232 KASSERT(m->m_pkthdr.len >= iplen, ("mbuf too short"));
237 ipf = ipflow_lookup(ip);
242 * Verify the IP header checksum.
244 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
245 if (!(m->m_pkthdr.csum_flags & CSUM_IP_VALID))
248 /* Must compute it ourselves. */
249 if (in_cksum_hdr(ip) != 0)
254 * Route and interface still up?
256 rt = ipf->ipf_ro.ro_rt;
257 if (IPFLOW_RTENTRY_ISDOWN(rt))
262 * Packet size OK? TTL?
264 if (m->m_pkthdr.len > ifp->if_mtu || ip->ip_ttl <= IPTTLDEC)
268 * Clear any in-bound checksum flags for this packet.
270 m->m_pkthdr.csum_flags = 0;
273 * Everything checks out and so we can forward this packet.
274 * Modify the TTL and incrementally change the checksum.
276 * This method of adding the checksum works on either endian CPU.
277 * If htons() is inlined, all the arithmetic is folded; otherwise
278 * the htons()s are combined by CSE due to the __const__ attribute.
280 * Don't bother using HW checksumming here -- the incremental
281 * update is pretty fast.
283 ip->ip_ttl -= IPTTLDEC;
284 if (ip->ip_sum >= (uint16_t)~htons(IPTTLDEC << 8))
285 ip->ip_sum -= ~htons(IPTTLDEC << 8);
287 ip->ip_sum += htons(IPTTLDEC << 8);
290 * Trim the packet in case it's too long..
292 if (m->m_pkthdr.len > iplen) {
293 if (m->m_len == m->m_pkthdr.len) {
295 m->m_pkthdr.len = iplen;
297 m_adj(m, iplen - m->m_pkthdr.len);
302 * Send the packet on its way. All we can get back is ENOBUFS
305 ipf->ipf_timer = IPFLOW_TIMER;
307 if (rt->rt_flags & RTF_GATEWAY)
308 dst = rt->rt_gateway;
310 dst = &ipf->ipf_ro.ro_dst;
313 * Reference count this ipflow, before the possible blocking
314 * ifnet.if_output(), so this ipflow will not be changed or
315 * reaped behind our back.
319 error = ifp->if_output(ifp, m, dst, rt);
321 if (error == ENOBUFS)
332 ipflow_addstats(struct ipflow *ipf)
334 ipf->ipf_ro.ro_rt->rt_use += ipf->ipf_uses;
335 ipstat.ips_cantforward += ipf->ipf_errors + ipf->ipf_dropped;
336 ipstat.ips_total += ipf->ipf_uses;
337 ipstat.ips_forward += ipf->ipf_uses;
338 ipstat.ips_fastforward += ipf->ipf_uses;
342 ipflow_free(struct ipflow *ipf)
344 KKASSERT(ipf->ipf_refcnt == 0);
345 KKASSERT((ipf->ipf_flags & IPFLOW_FLAG_ONLIST) == 0);
347 KKASSERT(ipflow_inuse > 0);
350 ipflow_addstats(ipf);
351 RTFREE(ipf->ipf_ro.ro_rt);
352 kfree(ipf, M_IPFLOW);
356 ipflow_reset(struct ipflow *ipf)
358 ipflow_addstats(ipf);
359 RTFREE(ipf->ipf_ro.ro_rt);
360 ipf->ipf_uses = ipf->ipf_last_uses = 0;
361 ipf->ipf_errors = ipf->ipf_dropped = 0;
364 static struct ipflow *
367 struct ipflow *ipf, *maybe_ipf = NULL;
369 LIST_FOREACH(ipf, &ipflowlist, ipf_list) {
371 * Skip actively used ipflow
373 if (IPFLOW_IS_ACTIVE(ipf))
377 * If this no longer points to a valid route
380 if ((ipf->ipf_ro.ro_rt->rt_flags & RTF_UP) == 0)
384 * choose the one that's been least recently used
385 * or has had the least uses in the last 1.5
388 if (maybe_ipf == NULL ||
389 ipf->ipf_timer < maybe_ipf->ipf_timer ||
390 (ipf->ipf_timer == maybe_ipf->ipf_timer &&
391 ipf->ipf_last_uses + ipf->ipf_uses <
392 maybe_ipf->ipf_last_uses + maybe_ipf->ipf_uses))
395 if (maybe_ipf == NULL)
401 * Remove the entry from the flow table and reset its states
409 ipflow_timeo_dispatch(netmsg_t nmsg)
411 struct ipflow *ipf, *next_ipf;
412 struct ipflow_pcpu *pcpu;
415 ASSERT_NETISR_NCPUS(curthread, cpuid);
418 lwkt_replymsg(&nmsg->lmsg, 0); /* reply ASAP */
421 LIST_FOREACH_MUTABLE(ipf, &ipflowlist, ipf_list, next_ipf) {
422 if (--ipf->ipf_timer == 0) {
426 ipf->ipf_last_uses = ipf->ipf_uses;
427 ipf->ipf_ro.ro_rt->rt_use += ipf->ipf_uses;
428 ipstat.ips_total += ipf->ipf_uses;
429 ipstat.ips_forward += ipf->ipf_uses;
430 ipstat.ips_fastforward += ipf->ipf_uses;
435 pcpu = &ipflow_pcpu_data[cpuid];
436 callout_reset(&pcpu->ipf_timeo, IPFLOW_TIMEOUT, ipflow_timeo, pcpu);
440 ipflow_timeo(void *xpcpu)
442 struct ipflow_pcpu *pcpu = xpcpu;
443 struct lwkt_msg *msg = &pcpu->ipf_timeo_netmsg.lmsg;
446 if (msg->ms_flags & MSGF_DONE)
447 lwkt_sendmsg_oncpu(netisr_cpuport(mycpuid), msg);
452 ipflow_create(const struct route *ro, struct mbuf *m)
454 const struct ip *const ip = mtod(m, struct ip *);
458 ASSERT_NETISR_NCPUS(curthread, mycpuid);
461 * Don't create cache entries for ICMP messages.
463 if (!ipflow_active || ip->ip_p == IPPROTO_ICMP)
467 * See if an existing flow struct exists. If so remove it from it's
468 * list and free the old route. If not, try to malloc a new one
469 * (if we aren't at our limit).
471 ipf = ipflow_lookup(ip);
473 if (ipflow_inuse == IPFLOW_MAX) {
478 ipf = kmalloc(sizeof(*ipf), M_IPFLOW,
482 ipf->ipf_refcnt = IPFLOW_REFCNT_INIT;
487 if (IPFLOW_NOT_ACTIVE(ipf)) {
491 /* This ipflow is being used; don't change it */
492 KKASSERT(IPFLOW_IS_ACTIVE(ipf));
496 /* This ipflow should not be actively used */
497 KKASSERT(IPFLOW_NOT_ACTIVE(ipf));
500 * Fill in the updated information.
503 ro->ro_rt->rt_refcnt++;
504 ipf->ipf_dst = ip->ip_dst;
505 ipf->ipf_src = ip->ip_src;
506 ipf->ipf_tos = ip->ip_tos;
507 ipf->ipf_timer = IPFLOW_TIMER;
510 * Insert into the approriate bucket of the flow table.
512 hash = ipflow_hash(ip->ip_dst, ip->ip_src, ip->ip_tos);
513 IPFLOW_INSERT(&ipflowtable[hash], ipf);
517 ipflow_flush_oncpu(void)
522 * FIXME: netisr_ncpus
523 * Change this into assert, after routes are duplicated
524 * to only netisr_ncpus.
526 if (mycpuid >= netisr_ncpus)
529 while ((ipf = LIST_FIRST(&ipflowlist)) != NULL) {
536 ipflow_ifaddr_handler(netmsg_t nmsg)
538 struct netmsg_ipfaddr *amsg = (struct netmsg_ipfaddr *)nmsg;
539 struct ipflow *ipf, *next_ipf;
541 LIST_FOREACH_MUTABLE(ipf, &ipflowlist, ipf_list, next_ipf) {
542 if (ipf->ipf_dst.s_addr == amsg->ipf_addr.s_addr ||
543 ipf->ipf_src.s_addr == amsg->ipf_addr.s_addr) {
548 netisr_forwardmsg(&nmsg->base, mycpuid + 1);
552 ipflow_ifaddr(void *arg __unused, struct ifnet *ifp __unused,
553 enum ifaddr_event event, struct ifaddr *ifa)
555 struct netmsg_ipfaddr amsg;
557 if (ifa->ifa_addr->sa_family != AF_INET)
560 /* Only add/change events need to be handled */
562 case IFADDR_EVENT_ADD:
563 case IFADDR_EVENT_CHANGE:
566 case IFADDR_EVENT_DELETE:
570 netmsg_init(&amsg.base, NULL, &curthread->td_msgport,
571 MSGF_PRIORITY, ipflow_ifaddr_handler);
572 amsg.ipf_addr = ifatoia(ifa)->ia_addr.sin_addr;
574 netisr_domsg(&amsg.base, 0);
583 ipflow_pcpu_data = kmalloc(sizeof(struct ipflow_pcpu) * netisr_ncpus,
584 M_IPFLOW, M_WAITOK | M_ZERO);
586 for (i = 0; i < netisr_ncpus; ++i) {
587 struct ipflow_pcpu *pcpu = &ipflow_pcpu_data[i];
589 netmsg_init(&pcpu->ipf_timeo_netmsg, NULL, &netisr_adone_rport,
590 MSGF_PRIORITY, ipflow_timeo_dispatch);
591 callout_init_mp(&pcpu->ipf_timeo);
593 ksnprintf(oid_name, sizeof(oid_name), "inuse%d", i);
596 SYSCTL_STATIC_CHILDREN(_net_inet_ip_ipflow), OID_AUTO,
597 oid_name, CTLFLAG_RD, &pcpu->ipf_inuse, 0,
598 "# of ip flow being used");
600 callout_reset_bycpu(&pcpu->ipf_timeo, IPFLOW_TIMEOUT,
601 ipflow_timeo, pcpu, i);
603 EVENTHANDLER_REGISTER(ifaddr_event, ipflow_ifaddr, NULL,
604 EVENTHANDLER_PRI_ANY);
606 SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, ipflow_init, 0);