/*- * Copyright (c) 1998 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by the 3am Software Foundry ("3am"). It was developed by Matt Thomas. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * $FreeBSD: src/sys/netinet/ip_flow.c,v 1.9.2.2 2001/11/04 17:35:31 luigi Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define IPFLOW_TIMEOUT_FREQ 2 /* 2/second */ #define IPFLOW_TIMEOUT (hz / IPFLOW_TIMEOUT_FREQ) #define IPFLOW_TIMER (5 * IPFLOW_TIMEOUT_FREQ) #define IPFLOW_HASHBITS 6 /* should not be a multiple of 8 */ #define IPFLOW_HASHSIZE (1 << IPFLOW_HASHBITS) #define IPFLOW_MAX 256 #define IPFLOW_RTENTRY_ISDOWN(rt) \ (((rt)->rt_flags & RTF_UP) == 0 || \ ((rt)->rt_ifp->if_flags & IFF_UP) == 0) struct netmsg_ipfaddr { struct netmsg_base base; struct in_addr ipf_addr; }; struct ipflow { LIST_ENTRY(ipflow) ipf_hash; /* next ipflow in hash bucket */ LIST_ENTRY(ipflow) ipf_list; /* next ipflow in list */ struct in_addr ipf_dst; /* destination address */ struct in_addr ipf_src; /* source address */ uint8_t ipf_tos; /* type-of-service */ uint8_t ipf_flags; /* see IPFLOW_FLAG_ */ uint8_t ipf_pad[2]; /* explicit pad */ int ipf_timer; /* remaining lifetime of this entry */ struct route ipf_ro; /* associated route entry */ u_long ipf_uses; /* number of uses in this period */ u_long ipf_dropped; /* ENOBUFS returned by if_output */ u_long ipf_errors; /* other errors returned by if_output */ u_long ipf_last_uses; /* number of uses in last period */ }; LIST_HEAD(ipflowhead, ipflow); #define IPFLOW_FLAG_ONLIST 0x1 struct ipflow_pcpu { struct ipflowhead ipf_table[IPFLOW_HASHSIZE]; struct ipflowhead ipf_list; int ipf_inuse; struct callout ipf_timeo; struct netmsg_base ipf_timeo_netmsg; }; static struct ipflow_pcpu *ipflow_pcpu_data[MAXCPU]; static int ipflow_active = 0; #define IPFLOW_INSERT(pcpu, bucket, ipf) \ do { \ KKASSERT(((ipf)->ipf_flags & IPFLOW_FLAG_ONLIST) == 0); \ (ipf)->ipf_flags |= IPFLOW_FLAG_ONLIST; \ LIST_INSERT_HEAD((bucket), (ipf), ipf_hash); \ LIST_INSERT_HEAD(&(pcpu)->ipf_list, (ipf), ipf_list); \ } while (0) #define IPFLOW_REMOVE(ipf) \ do { \ KKASSERT((ipf)->ipf_flags & IPFLOW_FLAG_ONLIST); \ (ipf)->ipf_flags &= ~IPFLOW_FLAG_ONLIST; \ LIST_REMOVE((ipf), ipf_hash); \ LIST_REMOVE((ipf), ipf_list); \ } while (0) SYSCTL_NODE(_net_inet_ip, OID_AUTO, ipflow, CTLFLAG_RW, 0, "ip flow"); SYSCTL_INT(_net_inet_ip, IPCTL_FASTFORWARDING, fastforwarding, CTLFLAG_RW, &ipflow_active, 0, "Enable flow-based IP forwarding"); static MALLOC_DEFINE(M_IPFLOW, "ip_flow", "IP flow"); static void ipflow_free(struct ipflow_pcpu *, struct ipflow *); static void ipflow_timeo(void *); static unsigned ipflow_hash(struct in_addr dst, struct in_addr src, unsigned tos) { unsigned hash = tos + src.s_addr; int idx; for (idx = IPFLOW_HASHBITS; idx < 32; idx += IPFLOW_HASHBITS) hash += (dst.s_addr >> (32 - idx)) + (src.s_addr >> idx); return hash & (IPFLOW_HASHSIZE-1); } static struct ipflow * ipflow_lookup(struct ipflow_pcpu *pcpu, const struct ip *ip) { unsigned hash; struct ipflow *ipf; hash = ipflow_hash(ip->ip_dst, ip->ip_src, ip->ip_tos); LIST_FOREACH(ipf, &pcpu->ipf_table[hash], ipf_hash) { if (ip->ip_dst.s_addr == ipf->ipf_dst.s_addr && ip->ip_src.s_addr == ipf->ipf_src.s_addr && ip->ip_tos == ipf->ipf_tos) break; } return ipf; } int ipflow_fastforward(struct mbuf *m) { struct ip *ip; struct ipflow *ipf; struct rtentry *rt; struct sockaddr *dst; struct ifnet *ifp; int error, iplen; ASSERT_NETISR_NCPUS(mycpuid); /* * Are we forwarding packets? */ if (!ipforwarding || !ipflow_active) return 0; /* * Was packet received as a link-level multicast or broadcast? * If so, don't try to fast forward.. */ if (m->m_flags & (M_BCAST | M_MCAST)) return 0; /* length checks already done in ip_hashfn() */ KASSERT(m->m_len >= sizeof(struct ip), ("IP header not in one mbuf")); ip = mtod(m, struct ip *); /* * IP header with no option and valid version */ if (ip->ip_v != IPVERSION || ip->ip_hl != (sizeof(struct ip) >> 2)) return 0; iplen = ntohs(ip->ip_len); /* length checks already done in ip_hashfn() */ KASSERT(iplen >= sizeof(struct ip), ("total length less than header length")); KASSERT(m->m_pkthdr.len >= iplen, ("mbuf too short")); /* * Find a flow. */ ipf = ipflow_lookup(ipflow_pcpu_data[mycpuid], ip); if (ipf == NULL) return 0; /* * Verify the IP header checksum. */ if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) { if (!(m->m_pkthdr.csum_flags & CSUM_IP_VALID)) return 0; } else { /* Must compute it ourselves. */ if (in_cksum_hdr(ip) != 0) return 0; } /* * Route and interface still up? */ rt = ipf->ipf_ro.ro_rt; if (IPFLOW_RTENTRY_ISDOWN(rt)) return 0; ifp = rt->rt_ifp; /* * Packet size OK? TTL? */ if (m->m_pkthdr.len > ifp->if_mtu || ip->ip_ttl <= IPTTLDEC) return 0; /* * Clear any in-bound checksum flags for this packet. */ m->m_pkthdr.csum_flags = 0; /* * Everything checks out and so we can forward this packet. * Modify the TTL and incrementally change the checksum. * * This method of adding the checksum works on either endian CPU. * If htons() is inlined, all the arithmetic is folded; otherwise * the htons()s are combined by CSE due to the __const__ attribute. * * Don't bother using HW checksumming here -- the incremental * update is pretty fast. */ ip->ip_ttl -= IPTTLDEC; if (ip->ip_sum >= (uint16_t)~htons(IPTTLDEC << 8)) ip->ip_sum -= ~htons(IPTTLDEC << 8); else ip->ip_sum += htons(IPTTLDEC << 8); /* * Trim the packet in case it's too long.. */ if (m->m_pkthdr.len > iplen) { if (m->m_len == m->m_pkthdr.len) { m->m_len = iplen; m->m_pkthdr.len = iplen; } else { m_adj(m, iplen - m->m_pkthdr.len); } } /* * Send the packet on its way. All we can get back is ENOBUFS */ ipf->ipf_uses++; ipf->ipf_timer = IPFLOW_TIMER; if (rt->rt_flags & RTF_GATEWAY) dst = rt->rt_gateway; else dst = &ipf->ipf_ro.ro_dst; error = ifp->if_output(ifp, m, dst, rt); if (error) { if (error == ENOBUFS) ipf->ipf_dropped++; else ipf->ipf_errors++; } return 1; } static void ipflow_addstats(struct ipflow *ipf) { ipf->ipf_ro.ro_rt->rt_use += ipf->ipf_uses; ipstat.ips_cantforward += ipf->ipf_errors + ipf->ipf_dropped; ipstat.ips_total += ipf->ipf_uses; ipstat.ips_forward += ipf->ipf_uses; ipstat.ips_fastforward += ipf->ipf_uses; } static void ipflow_free(struct ipflow_pcpu *pcpu, struct ipflow *ipf) { KKASSERT((ipf->ipf_flags & IPFLOW_FLAG_ONLIST) == 0); KKASSERT(pcpu->ipf_inuse > 0); pcpu->ipf_inuse--; ipflow_addstats(ipf); RTFREE(ipf->ipf_ro.ro_rt); kfree(ipf, M_IPFLOW); } static void ipflow_reset(struct ipflow *ipf) { ipflow_addstats(ipf); RTFREE(ipf->ipf_ro.ro_rt); ipf->ipf_uses = ipf->ipf_last_uses = 0; ipf->ipf_errors = ipf->ipf_dropped = 0; } static struct ipflow * ipflow_reap(struct ipflow_pcpu *pcpu) { struct ipflow *ipf, *maybe_ipf = NULL; LIST_FOREACH(ipf, &pcpu->ipf_list, ipf_list) { /* * If this no longer points to a valid route * reclaim it. */ if ((ipf->ipf_ro.ro_rt->rt_flags & RTF_UP) == 0) goto done; /* * choose the one that's been least recently used * or has had the least uses in the last 1.5 * intervals. */ if (maybe_ipf == NULL || ipf->ipf_timer < maybe_ipf->ipf_timer || (ipf->ipf_timer == maybe_ipf->ipf_timer && ipf->ipf_last_uses + ipf->ipf_uses < maybe_ipf->ipf_last_uses + maybe_ipf->ipf_uses)) maybe_ipf = ipf; } if (maybe_ipf == NULL) return NULL; ipf = maybe_ipf; done: /* * Remove the entry from the flow table and reset its states */ IPFLOW_REMOVE(ipf); ipflow_reset(ipf); return ipf; } static void ipflow_timeo_dispatch(netmsg_t nmsg) { struct ipflow *ipf, *next_ipf; struct ipflow_pcpu *pcpu = ipflow_pcpu_data[mycpuid]; ASSERT_NETISR_NCPUS(mycpuid); crit_enter(); netisr_replymsg(&nmsg->base, 0); /* reply ASAP */ crit_exit(); LIST_FOREACH_MUTABLE(ipf, &pcpu->ipf_list, ipf_list, next_ipf) { if (--ipf->ipf_timer == 0) { IPFLOW_REMOVE(ipf); ipflow_free(pcpu, ipf); } else { ipf->ipf_last_uses = ipf->ipf_uses; ipf->ipf_ro.ro_rt->rt_use += ipf->ipf_uses; ipstat.ips_total += ipf->ipf_uses; ipstat.ips_forward += ipf->ipf_uses; ipstat.ips_fastforward += ipf->ipf_uses; ipf->ipf_uses = 0; } } callout_reset(&pcpu->ipf_timeo, IPFLOW_TIMEOUT, ipflow_timeo, pcpu); } static void ipflow_timeo(void *xpcpu) { struct ipflow_pcpu *pcpu = xpcpu; struct netmsg_base *nm = &pcpu->ipf_timeo_netmsg; crit_enter(); if (nm->lmsg.ms_flags & MSGF_DONE) netisr_sendmsg_oncpu(nm); crit_exit(); } void ipflow_create(const struct route *ro, struct mbuf *m) { struct ipflow_pcpu *pcpu = ipflow_pcpu_data[mycpuid]; const struct ip *const ip = mtod(m, struct ip *); struct ipflow *ipf; unsigned hash; ASSERT_NETISR_NCPUS(mycpuid); /* * Don't create cache entries for ICMP messages. */ if (!ipflow_active || ip->ip_p == IPPROTO_ICMP) return; /* * See if an existing flow struct exists. If so remove it from it's * list and free the old route. If not, try to malloc a new one * (if we aren't at our limit). */ ipf = ipflow_lookup(pcpu, ip); if (ipf == NULL) { if (pcpu->ipf_inuse == IPFLOW_MAX) { ipf = ipflow_reap(pcpu); if (ipf == NULL) return; } else { ipf = kmalloc(sizeof(*ipf), M_IPFLOW, M_INTWAIT | M_NULLOK | M_ZERO); if (ipf == NULL) return; pcpu->ipf_inuse++; } } else { IPFLOW_REMOVE(ipf); ipflow_reset(ipf); } /* * Fill in the updated information. */ ipf->ipf_ro = *ro; ro->ro_rt->rt_refcnt++; ipf->ipf_dst = ip->ip_dst; ipf->ipf_src = ip->ip_src; ipf->ipf_tos = ip->ip_tos; ipf->ipf_timer = IPFLOW_TIMER; /* * Insert into the approriate bucket of the flow table. */ hash = ipflow_hash(ip->ip_dst, ip->ip_src, ip->ip_tos); IPFLOW_INSERT(pcpu, &pcpu->ipf_table[hash], ipf); } void ipflow_flush_oncpu(void) { struct ipflow_pcpu *pcpu = ipflow_pcpu_data[mycpuid]; struct ipflow *ipf; ASSERT_NETISR_NCPUS(mycpuid); while ((ipf = LIST_FIRST(&pcpu->ipf_list)) != NULL) { IPFLOW_REMOVE(ipf); ipflow_free(pcpu, ipf); } } static void ipflow_ifaddr_handler(netmsg_t nmsg) { struct netmsg_ipfaddr *amsg = (struct netmsg_ipfaddr *)nmsg; struct ipflow_pcpu *pcpu = ipflow_pcpu_data[mycpuid]; struct ipflow *ipf, *next_ipf; LIST_FOREACH_MUTABLE(ipf, &pcpu->ipf_list, ipf_list, next_ipf) { if (ipf->ipf_dst.s_addr == amsg->ipf_addr.s_addr || ipf->ipf_src.s_addr == amsg->ipf_addr.s_addr) { IPFLOW_REMOVE(ipf); ipflow_free(pcpu, ipf); } } netisr_forwardmsg(&nmsg->base, mycpuid + 1); } static void ipflow_ifaddr(void *arg __unused, struct ifnet *ifp __unused, enum ifaddr_event event, struct ifaddr *ifa) { struct netmsg_ipfaddr amsg; if (ifa->ifa_addr->sa_family != AF_INET) return; /* Only add/change events need to be handled */ switch (event) { case IFADDR_EVENT_ADD: case IFADDR_EVENT_CHANGE: break; case IFADDR_EVENT_DELETE: return; } netmsg_init(&amsg.base, NULL, &curthread->td_msgport, MSGF_PRIORITY, ipflow_ifaddr_handler); amsg.ipf_addr = ifatoia(ifa)->ia_addr.sin_addr; netisr_domsg_global(&amsg.base); } static void ipflow_init_dispatch(netmsg_t nm) { struct ipflow_pcpu *pcpu; int cpuid = mycpuid; char oid_name[32]; pcpu = kmalloc(sizeof(*pcpu), M_IPFLOW, M_WAITOK | M_ZERO); netmsg_init(&pcpu->ipf_timeo_netmsg, NULL, &netisr_adone_rport, MSGF_PRIORITY, ipflow_timeo_dispatch); callout_init_mp(&pcpu->ipf_timeo); ksnprintf(oid_name, sizeof(oid_name), "inuse%d", cpuid); SYSCTL_ADD_INT(NULL, SYSCTL_STATIC_CHILDREN(_net_inet_ip_ipflow), OID_AUTO, oid_name, CTLFLAG_RD, &pcpu->ipf_inuse, 0, "# of ip flow being used"); ipflow_pcpu_data[cpuid] = pcpu; callout_reset(&pcpu->ipf_timeo, IPFLOW_TIMEOUT, ipflow_timeo, pcpu); netisr_forwardmsg(&nm->base, cpuid + 1); } static void ipflow_init(void) { struct netmsg_base nm; netmsg_init(&nm, NULL, &curthread->td_msgport, 0, ipflow_init_dispatch); netisr_domsg_global(&nm); EVENTHANDLER_REGISTER(ifaddr_event, ipflow_ifaddr, NULL, EVENTHANDLER_PRI_ANY); } SYSINIT(arp, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY, ipflow_init, 0);