/* $OpenBSD: if_pflow.c,v 1.15 2011/04/05 18:01:21 henning Exp $ */ /* * Copyright (c) 2008 Henning Brauer * Copyright (c) 2008 Joerg Goltermann * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER IN * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #include #include #include #include #include #include #include #include #endif /* INET */ #include #include #include "bpfilter.h" #include "pflow.h" #define PFLOW_MINMTU \ (sizeof(struct pflow_header) + sizeof(struct pflow_flow)) #ifdef PFLOWDEBUG #define DPRINTF(x) do { printf x ; } while (0) #else #define DPRINTF(x) #endif SLIST_HEAD(, pflow_softc) pflowif_list; struct pflowstats pflowstats; void pflowattach(int); int pflow_clone_create(struct if_clone *, int); int pflow_clone_destroy(struct ifnet *); void pflow_setmtu(struct pflow_softc *, int); int pflowoutput(struct ifnet *, struct mbuf *, struct sockaddr *, struct rtentry *); int pflowioctl(struct ifnet *, u_long, caddr_t); void pflowstart(struct ifnet *); struct mbuf *pflow_get_mbuf(struct pflow_softc *); int pflow_sendout(struct pflow_softc *); int pflow_sendout_mbuf(struct pflow_softc *, struct mbuf *); void pflow_timeout(void *); void copy_flow_data(struct pflow_flow *, struct pflow_flow *, struct pf_state *, int, int); int pflow_pack_flow(struct pf_state *, struct pflow_softc *); int pflow_get_dynport(void); int export_pflow_if(struct pf_state*, struct pflow_softc *); int copy_flow_to_m(struct pflow_flow *flow, struct pflow_softc *sc); struct if_clone pflow_cloner = IF_CLONE_INITIALIZER("pflow", pflow_clone_create, pflow_clone_destroy); /* from in_pcb.c */ extern int ipport_hifirstauto; extern int ipport_hilastauto; /* from kern/kern_clock.c; incremented each clock tick. */ extern int ticks; void pflowattach(int npflow) { SLIST_INIT(&pflowif_list); if_clone_attach(&pflow_cloner); } int pflow_clone_create(struct if_clone *ifc, int unit) { struct ifnet *ifp; struct pflow_softc *pflowif; if ((pflowif = malloc(sizeof(*pflowif), M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL) return (ENOMEM); pflowif->sc_sender_ip.s_addr = INADDR_ANY; pflowif->sc_sender_port = pflow_get_dynport(); pflowif->sc_imo.imo_membership = malloc( (sizeof(struct in_multi *) * IP_MIN_MEMBERSHIPS), M_IPMOPTS, M_WAITOK|M_ZERO); pflowif->sc_imo.imo_max_memberships = IP_MIN_MEMBERSHIPS; pflowif->sc_receiver_ip.s_addr = 0; pflowif->sc_receiver_port = 0; pflowif->sc_sender_ip.s_addr = INADDR_ANY; pflowif->sc_sender_port = pflow_get_dynport(); ifp = &pflowif->sc_if; snprintf(ifp->if_xname, sizeof ifp->if_xname, "pflow%d", unit); ifp->if_softc = pflowif; ifp->if_ioctl = pflowioctl; ifp->if_output = pflowoutput; ifp->if_start = pflowstart; ifp->if_type = IFT_PFLOW; ifp->if_snd.ifq_maxlen = ifqmaxlen; ifp->if_hdrlen = PFLOW_HDRLEN; ifp->if_flags = IFF_UP; ifp->if_flags &= ~IFF_RUNNING; /* not running, need receiver */ pflow_setmtu(pflowif, ETHERMTU); timeout_set(&pflowif->sc_tmo, pflow_timeout, pflowif); if_attach(ifp); if_alloc_sadl(ifp); #if NBPFILTER > 0 bpfattach(&pflowif->sc_if.if_bpf, ifp, DLT_RAW, 0); #endif /* Insert into list of pflows */ SLIST_INSERT_HEAD(&pflowif_list, pflowif, sc_next); return (0); } int pflow_clone_destroy(struct ifnet *ifp) { struct pflow_softc *sc = ifp->if_softc; int s; s = splnet(); pflow_sendout(sc); if_detach(ifp); SLIST_REMOVE(&pflowif_list, sc, pflow_softc, sc_next); free(sc->sc_imo.imo_membership, M_IPMOPTS); free(sc, M_DEVBUF); splx(s); return (0); } /* * Start output on the pflow interface. */ void pflowstart(struct ifnet *ifp) { struct mbuf *m; int s; for (;;) { s = splnet(); IF_DROP(&ifp->if_snd); IF_DEQUEUE(&ifp->if_snd, m); splx(s); if (m == NULL) return; m_freem(m); } } int pflowoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, struct rtentry *rt) { m_freem(m); return (0); } /* ARGSUSED */ int pflowioctl(struct ifnet *ifp, u_long cmd, caddr_t data) { struct proc *p = curproc; struct pflow_softc *sc = ifp->if_softc; struct ifreq *ifr = (struct ifreq *)data; struct pflowreq pflowr; int s, error; switch (cmd) { case SIOCSIFADDR: case SIOCAIFADDR: case SIOCSIFDSTADDR: case SIOCSIFFLAGS: if ((ifp->if_flags & IFF_UP) && sc->sc_receiver_ip.s_addr != 0 && sc->sc_receiver_port != 0) { ifp->if_flags |= IFF_RUNNING; sc->sc_gcounter=pflowstats.pflow_flows; } else ifp->if_flags &= ~IFF_RUNNING; break; case SIOCSIFMTU: if (ifr->ifr_mtu < PFLOW_MINMTU) return (EINVAL); if (ifr->ifr_mtu > MCLBYTES) ifr->ifr_mtu = MCLBYTES; s = splnet(); if (ifr->ifr_mtu < ifp->if_mtu) pflow_sendout(sc); pflow_setmtu(sc, ifr->ifr_mtu); splx(s); break; case SIOCGETPFLOW: bzero(&pflowr, sizeof(pflowr)); pflowr.sender_ip = sc->sc_sender_ip; pflowr.receiver_ip = sc->sc_receiver_ip; pflowr.receiver_port = sc->sc_receiver_port; if ((error = copyout(&pflowr, ifr->ifr_data, sizeof(pflowr)))) return (error); break; case SIOCSETPFLOW: if ((error = suser(p, p->p_acflag)) != 0) return (error); if ((error = copyin(ifr->ifr_data, &pflowr, sizeof(pflowr)))) return (error); s = splnet(); pflow_sendout(sc); splx(s); if (pflowr.addrmask & PFLOW_MASK_DSTIP) sc->sc_receiver_ip = pflowr.receiver_ip; if (pflowr.addrmask & PFLOW_MASK_DSTPRT) sc->sc_receiver_port = pflowr.receiver_port; if (pflowr.addrmask & PFLOW_MASK_SRCIP) sc->sc_sender_ip.s_addr = pflowr.sender_ip.s_addr; if ((ifp->if_flags & IFF_UP) && sc->sc_receiver_ip.s_addr != 0 && sc->sc_receiver_port != 0) { ifp->if_flags |= IFF_RUNNING; sc->sc_gcounter=pflowstats.pflow_flows; } else ifp->if_flags &= ~IFF_RUNNING; break; default: return (ENOTTY); } return (0); } void pflow_setmtu(struct pflow_softc *sc, int mtu_req) { int mtu; if (sc->sc_pflow_ifp && sc->sc_pflow_ifp->if_mtu < mtu_req) mtu = sc->sc_pflow_ifp->if_mtu; else mtu = mtu_req; sc->sc_maxcount = (mtu - sizeof(struct pflow_header) - sizeof (struct udpiphdr)) / sizeof(struct pflow_flow); if (sc->sc_maxcount > PFLOW_MAXFLOWS) sc->sc_maxcount = PFLOW_MAXFLOWS; sc->sc_if.if_mtu = sizeof(struct pflow_header) + sizeof (struct udpiphdr) + sc->sc_maxcount * sizeof(struct pflow_flow); } struct mbuf * pflow_get_mbuf(struct pflow_softc *sc) { struct pflow_header h; struct mbuf *m; MGETHDR(m, M_DONTWAIT, MT_DATA); if (m == NULL) { pflowstats.pflow_onomem++; return (NULL); } MCLGET(m, M_DONTWAIT); if ((m->m_flags & M_EXT) == 0) { m_free(m); pflowstats.pflow_onomem++; return (NULL); } m->m_len = m->m_pkthdr.len = 0; m->m_pkthdr.rcvif = NULL; /* populate pflow_header */ h.reserved1 = 0; h.reserved2 = 0; h.count = 0; h.version = htons(PFLOW_VERSION); h.flow_sequence = htonl(sc->sc_gcounter); h.engine_type = PFLOW_ENGINE_TYPE; h.engine_id = PFLOW_ENGINE_ID; m_copyback(m, 0, PFLOW_HDRLEN, &h, M_NOWAIT); sc->sc_count = 0; timeout_add_sec(&sc->sc_tmo, PFLOW_TIMEOUT); return (m); } void copy_flow_data(struct pflow_flow *flow1, struct pflow_flow *flow2, struct pf_state *st, int src, int dst) { struct pf_state_key *sk = st->key[PF_SK_WIRE]; flow1->src_ip = flow2->dest_ip = sk->addr[src].v4.s_addr; flow1->src_port = flow2->dest_port = sk->port[src]; flow1->dest_ip = flow2->src_ip = sk->addr[dst].v4.s_addr; flow1->dest_port = flow2->src_port = sk->port[dst]; flow1->dest_as = flow2->src_as = flow1->src_as = flow2->dest_as = 0; flow1->if_index_out = flow2->if_index_in = flow1->if_index_in = flow2->if_index_out = 0; flow1->dest_mask = flow2->src_mask = flow1->src_mask = flow2->dest_mask = 0; flow1->flow_packets = htonl(st->packets[0]); flow2->flow_packets = htonl(st->packets[1]); flow1->flow_octets = htonl(st->bytes[0]); flow2->flow_octets = htonl(st->bytes[1]); flow1->flow_start = flow2->flow_start = htonl((st->creation - (time_second - time_uptime)) * 1000); flow1->flow_finish = flow2->flow_finish = htonl((time_uptime - (st->rule.ptr->timeout[st->timeout] ? st->rule.ptr->timeout[st->timeout] : pf_default_rule.timeout[st->timeout])) * 1000); flow1->tcp_flags = flow2->tcp_flags = 0; flow1->protocol = flow2->protocol = sk->proto; flow1->tos = flow2->tos = st->rule.ptr->tos; } int export_pflow(struct pf_state *st) { struct pflow_softc *sc = NULL; struct pf_state_key *sk = st->key[PF_SK_WIRE]; if (sk->af != AF_INET) return (0); SLIST_FOREACH(sc, &pflowif_list, sc_next) { export_pflow_if(st, sc); } return (0); } int export_pflow_if(struct pf_state *st, struct pflow_softc *sc) { struct pf_state pfs_copy; struct ifnet *ifp = &sc->sc_if; u_int64_t bytes[2]; int ret = 0; if (!(ifp->if_flags & IFF_RUNNING)) return (0); if ((st->bytes[0] < (u_int64_t)PFLOW_MAXBYTES) && (st->bytes[1] < (u_int64_t)PFLOW_MAXBYTES)) return (pflow_pack_flow(st, sc)); /* flow > PFLOW_MAXBYTES need special handling */ bcopy(st, &pfs_copy, sizeof(pfs_copy)); bytes[0] = pfs_copy.bytes[0]; bytes[1] = pfs_copy.bytes[1]; while (bytes[0] > PFLOW_MAXBYTES) { pfs_copy.bytes[0] = PFLOW_MAXBYTES; pfs_copy.bytes[1] = 0; if ((ret = pflow_pack_flow(&pfs_copy, sc)) != 0) return (ret); if ((bytes[0] - PFLOW_MAXBYTES) > 0) bytes[0] -= PFLOW_MAXBYTES; } while (bytes[1] > (u_int64_t)PFLOW_MAXBYTES) { pfs_copy.bytes[1] = PFLOW_MAXBYTES; pfs_copy.bytes[0] = 0; if ((ret = pflow_pack_flow(&pfs_copy, sc)) != 0) return (ret); if ((bytes[1] - PFLOW_MAXBYTES) > 0) bytes[1] -= PFLOW_MAXBYTES; } pfs_copy.bytes[0] = bytes[0]; pfs_copy.bytes[1] = bytes[1]; return (pflow_pack_flow(&pfs_copy, sc)); } int copy_flow_to_m(struct pflow_flow *flow, struct pflow_softc *sc) { int s, ret = 0; s = splnet(); if (sc->sc_mbuf == NULL) { if ((sc->sc_mbuf = pflow_get_mbuf(sc)) == NULL) { splx(s); return (ENOBUFS); } } m_copyback(sc->sc_mbuf, PFLOW_HDRLEN + (sc->sc_count * sizeof (struct pflow_flow)), sizeof (struct pflow_flow), flow, M_NOWAIT); if (pflowstats.pflow_flows == sc->sc_gcounter) pflowstats.pflow_flows++; sc->sc_gcounter++; sc->sc_count++; if (sc->sc_count >= sc->sc_maxcount) ret = pflow_sendout(sc); splx(s); return(ret); } int pflow_pack_flow(struct pf_state *st, struct pflow_softc *sc) { struct pflow_flow flow1; struct pflow_flow flow2; int ret = 0; bzero(&flow1, sizeof(flow1)); bzero(&flow2, sizeof(flow2)); if (st->direction == PF_OUT) copy_flow_data(&flow1, &flow2, st, 1, 0); else copy_flow_data(&flow1, &flow2, st, 0, 1); if (st->bytes[0] != 0) /* first flow from state */ ret = copy_flow_to_m(&flow1, sc); if (st->bytes[1] != 0) /* second flow from state */ ret = copy_flow_to_m(&flow2, sc); return (ret); } void pflow_timeout(void *v) { struct pflow_softc *sc = v; int s; s = splnet(); pflow_sendout(sc); splx(s); } /* This must be called in splnet() */ int pflow_sendout(struct pflow_softc *sc) { struct mbuf *m = sc->sc_mbuf; struct pflow_header *h; struct ifnet *ifp = &sc->sc_if; timeout_del(&sc->sc_tmo); if (m == NULL) return (0); sc->sc_mbuf = NULL; if (!(ifp->if_flags & IFF_RUNNING)) { m_freem(m); return (0); } pflowstats.pflow_packets++; h = mtod(m, struct pflow_header *); h->count = htons(sc->sc_count); /* populate pflow_header */ h->uptime_ms = htonl(time_uptime * 1000); h->time_sec = htonl(time_second); h->time_nanosec = htonl(ticks); return (pflow_sendout_mbuf(sc, m)); } int pflow_sendout_mbuf(struct pflow_softc *sc, struct mbuf *m) { struct udpiphdr *ui; u_int16_t len = m->m_pkthdr.len; struct ifnet *ifp = &sc->sc_if; struct ip *ip; int err; /* UDP Header*/ M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT); if (m == NULL) { pflowstats.pflow_onomem++; return (ENOBUFS); } ui = mtod(m, struct udpiphdr *); ui->ui_pr = IPPROTO_UDP; ui->ui_src = sc->sc_sender_ip; ui->ui_sport = sc->sc_sender_port; ui->ui_dst = sc->sc_receiver_ip; ui->ui_dport = sc->sc_receiver_port; ui->ui_ulen = htons(sizeof (struct udphdr) + len); ip = (struct ip *)ui; ip->ip_v = IPVERSION; ip->ip_hl = sizeof(struct ip) >> 2; ip->ip_id = htons(ip_randomid()); ip->ip_off = htons(IP_DF); ip->ip_tos = IPTOS_LOWDELAY; ip->ip_ttl = IPDEFTTL; ip->ip_len = htons(sizeof (struct udpiphdr) + len); /* * Compute the pseudo-header checksum; defer further checksumming * until ip_output() or hardware (if it exists). */ m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT; ui->ui_sum = in_cksum_phdr(ui->ui_src.s_addr, ui->ui_dst.s_addr, htons(len + sizeof(struct udphdr) + IPPROTO_UDP)); #if NBPFILTER > 0 if (ifp->if_bpf) { ip->ip_sum = in_cksum(m, ip->ip_hl << 2); bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_OUT); } #endif sc->sc_if.if_opackets++; sc->sc_if.if_obytes += m->m_pkthdr.len; if ((err = ip_output(m, NULL, NULL, IP_RAWOUTPUT, &sc->sc_imo, NULL))) { pflowstats.pflow_oerrors++; sc->sc_if.if_oerrors++; } return (err); } int pflow_get_dynport(void) { u_int16_t tmp, low, high, cut; low = ipport_hifirstauto; /* sysctl */ high = ipport_hilastauto; cut = arc4random_uniform(1 + high - low) + low; for (tmp = cut; tmp <= high; ++(tmp)) { if (!in_baddynamic(tmp, IPPROTO_UDP)) return (htons(tmp)); } for (tmp = cut - 1; tmp >= low; --(tmp)) { if (!in_baddynamic(tmp, IPPROTO_UDP)) return (htons(tmp)); } return (htons(ipport_hilastauto)); /* XXX */ } int pflow_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen) { if (namelen != 1) return (ENOTDIR); switch (name[0]) { case NET_PFLOW_STATS: if (newp != NULL) return (EPERM); return (sysctl_struct(oldp, oldlenp, newp, newlen, &pflowstats, sizeof(pflowstats))); default: return (EOPNOTSUPP); } return (0); }