diff --git a/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c b/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c index 84fac0205ffc..3d3601ede00f 100644 --- a/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c +++ b/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c @@ -1,1459 +1,1456 @@ /* * Copyright (C) 2012 by Darren Reed. * * See the IPFILTER.LICENCE file for details on licencing. */ #if defined(KERNEL) || defined(_KERNEL) # undef KERNEL # undef _KERNEL # define KERNEL 1 # define _KERNEL 1 #endif #if defined(__FreeBSD__) && \ !defined(KLD_MODULE) && !defined(IPFILTER_LKM) # include "opt_inet6.h" #endif #include #include #include #include #include #include #include #include #include #include #include #if defined(__FreeBSD__) # include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "netinet/ip_compat.h" #ifdef USE_INET6 # include #endif #include "netinet/ip_fil.h" #include "netinet/ip_nat.h" #include "netinet/ip_frag.h" #include "netinet/ip_state.h" #include "netinet/ip_proxy.h" #include "netinet/ip_auth.h" #include "netinet/ip_sync.h" #include "netinet/ip_lookup.h" #include "netinet/ip_dstlist.h" #ifdef IPFILTER_SCAN # include "netinet/ip_scan.h" #endif #include "netinet/ip_pool.h" #include #include #ifdef CSUM_DATA_VALID # include #endif extern int ip_optcopy(struct ip *, struct ip *); #ifdef IPFILTER_M_IPFILTER MALLOC_DEFINE(M_IPFILTER, "ipfilter", "IP Filter packet filter data structures"); #endif static int ipf_send_ip(fr_info_t *, mb_t *); static void ipf_timer_func(void *arg); VNET_DEFINE(ipf_main_softc_t, ipfmain) = { .ipf_running = -2, }; #define V_ipfmain VNET(ipfmain) #include #include VNET_DEFINE_STATIC(eventhandler_tag, ipf_arrivetag); VNET_DEFINE_STATIC(eventhandler_tag, ipf_departtag); #define V_ipf_arrivetag VNET(ipf_arrivetag) #define V_ipf_departtag VNET(ipf_departtag) #if 0 /* * Disable the "cloner" event handler; we are getting interface * events before the firewall is fully initiallized and also no vnet * information thus leading to uninitialised memory accesses. * In addition it is unclear why we need it in first place. * If it turns out to be needed, well need a dedicated event handler * for it to deal with the ifc and the correct vnet. */ VNET_DEFINE_STATIC(eventhandler_tag, ipf_clonetag); #define V_ipf_clonetag VNET(ipf_clonetag) #endif static void ipf_ifevent(void *arg, struct ifnet *ifp); static void ipf_ifevent(void *arg, struct ifnet *ifp) { CURVNET_SET(ifp->if_vnet); if (V_ipfmain.ipf_running > 0) ipf_sync(&V_ipfmain, NULL); CURVNET_RESTORE(); } static pfil_return_t ipf_check_wrapper(struct mbuf **mp, struct ifnet *ifp, int flags, void *ruleset __unused, struct inpcb *inp) { struct ip *ip = mtod(*mp, struct ip *); pfil_return_t rv; CURVNET_SET(ifp->if_vnet); rv = ipf_check(&V_ipfmain, ip, ip->ip_hl << 2, ifp, !!(flags & PFIL_OUT), mp); CURVNET_RESTORE(); if (rv == 0 && *mp == NULL) return (PFIL_CONSUMED); return (rv == 0 ? PFIL_PASS : PFIL_DROPPED); } #ifdef USE_INET6 static pfil_return_t ipf_check_wrapper6(struct mbuf **mp, struct ifnet *ifp, int flags, void *ruleset __unused, struct inpcb *inp) { pfil_return_t rv; CURVNET_SET(ifp->if_vnet); rv = ipf_check(&V_ipfmain, mtod(*mp, struct ip *), sizeof(struct ip6_hdr), ifp, !!(flags & PFIL_OUT), mp); CURVNET_RESTORE(); if (rv == 0 && *mp == NULL) return (PFIL_CONSUMED); return (rv == 0 ? PFIL_PASS : PFIL_DROPPED); } # endif #if defined(IPFILTER_LKM) int ipf_identify(char *s) { if (strcmp(s, "ipl") == 0) return (1); return (0); } #endif /* IPFILTER_LKM */ static void ipf_timer_func(void *arg) { ipf_main_softc_t *softc = arg; SPL_INT(s); SPL_NET(s); - READ_ENTER(&softc->ipf_global); if (softc->ipf_running > 0) ipf_slowtimer(softc); if (softc->ipf_running == -1 || softc->ipf_running == 1) { - callout_init(&softc->ipf_slow_ch, 1); callout_reset(&softc->ipf_slow_ch, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT, ipf_timer_func, softc); } - RWLOCK_EXIT(&softc->ipf_global); SPL_X(s); } int ipfattach(ipf_main_softc_t *softc) { #ifdef USE_SPL int s; #endif SPL_NET(s); if (softc->ipf_running > 0) { SPL_X(s); return (EBUSY); } if (ipf_init_all(softc) < 0) { SPL_X(s); return (EIO); } bzero((char *)V_ipfmain.ipf_selwait, sizeof(V_ipfmain.ipf_selwait)); softc->ipf_running = 1; if (softc->ipf_control_forwarding & 1) V_ipforwarding = 1; SPL_X(s); #if 0 softc->ipf_slow_ch = timeout(ipf_timer_func, softc, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT); #endif - callout_init(&softc->ipf_slow_ch, 1); + callout_init_rw(&softc->ipf_slow_ch, &softc->ipf_global.ipf_lk, CALLOUT_SHAREDLOCK); callout_reset(&softc->ipf_slow_ch, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT, ipf_timer_func, softc); return (0); } /* * Disable the filter by removing the hooks from the IP input/output * stream. */ int ipfdetach(ipf_main_softc_t *softc) { #ifdef USE_SPL int s; #endif if (softc->ipf_control_forwarding & 2) V_ipforwarding = 0; SPL_NET(s); #if 0 if (softc->ipf_slow_ch.callout != NULL) untimeout(ipf_timer_func, softc, softc->ipf_slow_ch); bzero(&softc->ipf_slow, sizeof(softc->ipf_slow)); #endif callout_drain(&softc->ipf_slow_ch); ipf_fini_all(softc); softc->ipf_running = -2; SPL_X(s); return (0); } /* * Filter ioctl interface. */ int ipfioctl(struct cdev *dev, ioctlcmd_t cmd, caddr_t data, int mode, struct thread *p) #define p_cred td_ucred #define p_uid td_ucred->cr_ruid { int error = 0, unit = 0; SPL_INT(s); CURVNET_SET(TD_TO_VNET(p)); if (securelevel_ge(p->p_cred, 3) && (mode & FWRITE)) { V_ipfmain.ipf_interror = 130001; CURVNET_RESTORE(); return (EPERM); } if (jailed_without_vnet(p->p_cred)) { V_ipfmain.ipf_interror = 130018; CURVNET_RESTORE(); return (EOPNOTSUPP); } unit = GET_MINOR(dev); if ((IPL_LOGMAX < unit) || (unit < 0)) { V_ipfmain.ipf_interror = 130002; CURVNET_RESTORE(); return (ENXIO); } if (V_ipfmain.ipf_running <= 0) { if (unit != IPL_LOGIPF && cmd != SIOCIPFINTERROR) { V_ipfmain.ipf_interror = 130003; CURVNET_RESTORE(); return (EIO); } if (cmd != SIOCIPFGETNEXT && cmd != SIOCIPFGET && cmd != SIOCIPFSET && cmd != SIOCFRENB && cmd != SIOCGETFS && cmd != SIOCGETFF && cmd != SIOCIPFINTERROR) { V_ipfmain.ipf_interror = 130004; CURVNET_RESTORE(); return (EIO); } } SPL_NET(s); error = ipf_ioctlswitch(&V_ipfmain, unit, data, cmd, mode, p->p_uid, p); CURVNET_RESTORE(); if (error != -1) { SPL_X(s); return (error); } SPL_X(s); return (error); } /* * ipf_send_reset - this could conceivably be a call to tcp_respond(), but that * requires a large amount of setting up and isn't any more efficient. */ int ipf_send_reset(fr_info_t *fin) { struct tcphdr *tcp, *tcp2; int tlen = 0, hlen; struct mbuf *m; #ifdef USE_INET6 ip6_t *ip6; #endif ip_t *ip; tcp = fin->fin_dp; if (tcp->th_flags & TH_RST) return (-1); /* feedback loop */ if (ipf_checkl4sum(fin) == -1) return (-1); tlen = fin->fin_dlen - (TCP_OFF(tcp) << 2) + ((tcp->th_flags & TH_SYN) ? 1 : 0) + ((tcp->th_flags & TH_FIN) ? 1 : 0); #ifdef USE_INET6 hlen = (fin->fin_v == 6) ? sizeof(ip6_t) : sizeof(ip_t); #else hlen = sizeof(ip_t); #endif #ifdef MGETHDR MGETHDR(m, M_NOWAIT, MT_HEADER); #else MGET(m, M_NOWAIT, MT_HEADER); #endif if (m == NULL) return (-1); if (sizeof(*tcp2) + hlen > MLEN) { if (!(MCLGET(m, M_NOWAIT))) { FREE_MB_T(m); return (-1); } } m->m_len = sizeof(*tcp2) + hlen; m->m_data += max_linkhdr; m->m_pkthdr.len = m->m_len; m->m_pkthdr.rcvif = (struct ifnet *)0; ip = mtod(m, struct ip *); bzero((char *)ip, hlen); #ifdef USE_INET6 ip6 = (ip6_t *)ip; #endif tcp2 = (struct tcphdr *)((char *)ip + hlen); tcp2->th_sport = tcp->th_dport; tcp2->th_dport = tcp->th_sport; if (tcp_get_flags(tcp) & TH_ACK) { tcp2->th_seq = tcp->th_ack; tcp_set_flags(tcp2, TH_RST); tcp2->th_ack = 0; } else { tcp2->th_seq = 0; tcp2->th_ack = ntohl(tcp->th_seq); tcp2->th_ack += tlen; tcp2->th_ack = htonl(tcp2->th_ack); tcp_set_flags(tcp2, TH_RST|TH_ACK); } TCP_OFF_A(tcp2, sizeof(*tcp2) >> 2); tcp2->th_win = tcp->th_win; tcp2->th_sum = 0; tcp2->th_urp = 0; #ifdef USE_INET6 if (fin->fin_v == 6) { ip6->ip6_flow = ((ip6_t *)fin->fin_ip)->ip6_flow; ip6->ip6_plen = htons(sizeof(struct tcphdr)); ip6->ip6_nxt = IPPROTO_TCP; ip6->ip6_hlim = 0; ip6->ip6_src = fin->fin_dst6.in6; ip6->ip6_dst = fin->fin_src6.in6; tcp2->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(*ip6), sizeof(*tcp2)); return (ipf_send_ip(fin, m)); } #endif ip->ip_p = IPPROTO_TCP; ip->ip_len = htons(sizeof(struct tcphdr)); ip->ip_src.s_addr = fin->fin_daddr; ip->ip_dst.s_addr = fin->fin_saddr; tcp2->th_sum = in_cksum(m, hlen + sizeof(*tcp2)); ip->ip_len = htons(hlen + sizeof(*tcp2)); return (ipf_send_ip(fin, m)); } /* * ip_len must be in network byte order when called. */ static int ipf_send_ip(fr_info_t *fin, mb_t *m) { fr_info_t fnew; ip_t *ip, *oip; int hlen; ip = mtod(m, ip_t *); bzero((char *)&fnew, sizeof(fnew)); fnew.fin_main_soft = fin->fin_main_soft; IP_V_A(ip, fin->fin_v); switch (fin->fin_v) { case 4 : oip = fin->fin_ip; hlen = sizeof(*oip); fnew.fin_v = 4; fnew.fin_p = ip->ip_p; fnew.fin_plen = ntohs(ip->ip_len); IP_HL_A(ip, sizeof(*oip) >> 2); ip->ip_tos = oip->ip_tos; ip->ip_id = fin->fin_ip->ip_id; ip->ip_off = htons(V_path_mtu_discovery ? IP_DF : 0); ip->ip_ttl = V_ip_defttl; ip->ip_sum = 0; break; #ifdef USE_INET6 case 6 : { ip6_t *ip6 = (ip6_t *)ip; ip6->ip6_vfc = 0x60; ip6->ip6_hlim = IPDEFTTL; hlen = sizeof(*ip6); fnew.fin_p = ip6->ip6_nxt; fnew.fin_v = 6; fnew.fin_plen = ntohs(ip6->ip6_plen) + hlen; break; } #endif default : return (EINVAL); } #ifdef IPSEC_SUPPORT m->m_pkthdr.rcvif = NULL; #endif fnew.fin_ifp = fin->fin_ifp; fnew.fin_flx = FI_NOCKSUM; fnew.fin_m = m; fnew.fin_ip = ip; fnew.fin_mp = &m; fnew.fin_hlen = hlen; fnew.fin_dp = (char *)ip + hlen; (void) ipf_makefrip(hlen, ip, &fnew); return (ipf_fastroute(m, &m, &fnew, NULL)); } int ipf_send_icmp_err(int type, fr_info_t *fin, int dst) { int err, hlen, xtra, iclen, ohlen, avail, code; struct in_addr dst4; struct icmp *icmp; struct mbuf *m; i6addr_t dst6; void *ifp; #ifdef USE_INET6 ip6_t *ip6; #endif ip_t *ip, *ip2; if ((type < 0) || (type >= ICMP_MAXTYPE)) return (-1); code = fin->fin_icode; #ifdef USE_INET6 /* See NetBSD ip_fil_netbsd.c r1.4: */ if ((code < 0) || (code >= sizeof(icmptoicmp6unreach)/sizeof(int))) return (-1); #endif if (ipf_checkl4sum(fin) == -1) return (-1); #ifdef MGETHDR MGETHDR(m, M_NOWAIT, MT_HEADER); #else MGET(m, M_NOWAIT, MT_HEADER); #endif if (m == NULL) return (-1); avail = MHLEN; xtra = 0; hlen = 0; ohlen = 0; dst4.s_addr = 0; ifp = fin->fin_ifp; if (fin->fin_v == 4) { if ((fin->fin_p == IPPROTO_ICMP) && !(fin->fin_flx & FI_SHORT)) switch (ntohs(fin->fin_data[0]) >> 8) { case ICMP_ECHO : case ICMP_TSTAMP : case ICMP_IREQ : case ICMP_MASKREQ : break; default : FREE_MB_T(m); return (0); } if (dst == 0) { if (ipf_ifpaddr(&V_ipfmain, 4, FRI_NORMAL, ifp, &dst6, NULL) == -1) { FREE_MB_T(m); return (-1); } dst4 = dst6.in4; } else dst4.s_addr = fin->fin_daddr; hlen = sizeof(ip_t); ohlen = fin->fin_hlen; iclen = hlen + offsetof(struct icmp, icmp_ip) + ohlen; if (fin->fin_hlen < fin->fin_plen) xtra = MIN(fin->fin_dlen, 8); else xtra = 0; } #ifdef USE_INET6 else if (fin->fin_v == 6) { hlen = sizeof(ip6_t); ohlen = sizeof(ip6_t); iclen = hlen + offsetof(struct icmp, icmp_ip) + ohlen; type = icmptoicmp6types[type]; if (type == ICMP6_DST_UNREACH) code = icmptoicmp6unreach[code]; if (iclen + max_linkhdr + fin->fin_plen > avail) { if (!(MCLGET(m, M_NOWAIT))) { FREE_MB_T(m); return (-1); } avail = MCLBYTES; } xtra = MIN(fin->fin_plen, avail - iclen - max_linkhdr); xtra = MIN(xtra, IPV6_MMTU - iclen); if (dst == 0) { if (ipf_ifpaddr(&V_ipfmain, 6, FRI_NORMAL, ifp, &dst6, NULL) == -1) { FREE_MB_T(m); return (-1); } } else dst6 = fin->fin_dst6; } #endif else { FREE_MB_T(m); return (-1); } avail -= (max_linkhdr + iclen); if (avail < 0) { FREE_MB_T(m); return (-1); } if (xtra > avail) xtra = avail; iclen += xtra; m->m_data += max_linkhdr; m->m_pkthdr.rcvif = (struct ifnet *)0; m->m_pkthdr.len = iclen; m->m_len = iclen; ip = mtod(m, ip_t *); icmp = (struct icmp *)((char *)ip + hlen); ip2 = (ip_t *)&icmp->icmp_ip; icmp->icmp_type = type; icmp->icmp_code = fin->fin_icode; icmp->icmp_cksum = 0; #ifdef icmp_nextmtu if (type == ICMP_UNREACH && fin->fin_icode == ICMP_UNREACH_NEEDFRAG) { if (fin->fin_mtu != 0) { icmp->icmp_nextmtu = htons(fin->fin_mtu); } else if (ifp != NULL) { icmp->icmp_nextmtu = htons(GETIFMTU_4(ifp)); } else { /* make up a number... */ icmp->icmp_nextmtu = htons(fin->fin_plen - 20); } } #endif bcopy((char *)fin->fin_ip, (char *)ip2, ohlen); #ifdef USE_INET6 ip6 = (ip6_t *)ip; if (fin->fin_v == 6) { ip6->ip6_flow = ((ip6_t *)fin->fin_ip)->ip6_flow; ip6->ip6_plen = htons(iclen - hlen); ip6->ip6_nxt = IPPROTO_ICMPV6; ip6->ip6_hlim = 0; ip6->ip6_src = dst6.in6; ip6->ip6_dst = fin->fin_src6.in6; if (xtra > 0) bcopy((char *)fin->fin_ip + ohlen, (char *)&icmp->icmp_ip + ohlen, xtra); icmp->icmp_cksum = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), iclen - hlen); } else #endif { ip->ip_p = IPPROTO_ICMP; ip->ip_src.s_addr = dst4.s_addr; ip->ip_dst.s_addr = fin->fin_saddr; if (xtra > 0) bcopy((char *)fin->fin_ip + ohlen, (char *)&icmp->icmp_ip + ohlen, xtra); icmp->icmp_cksum = ipf_cksum((u_short *)icmp, sizeof(*icmp) + 8); ip->ip_len = htons(iclen); ip->ip_p = IPPROTO_ICMP; } err = ipf_send_ip(fin, m); return (err); } /* * m0 - pointer to mbuf where the IP packet starts * mpp - pointer to the mbuf pointer that is the start of the mbuf chain */ int ipf_fastroute(mb_t *m0, mb_t **mpp, fr_info_t *fin, frdest_t *fdp) { register struct ip *ip, *mhip; register struct mbuf *m = *mpp; int len, off, error = 0, hlen, code; struct ifnet *ifp, *sifp; struct route ro; struct sockaddr_in *dst; const struct sockaddr *gw; struct nhop_object *nh; u_long fibnum = 0; u_short ip_off; frdest_t node; frentry_t *fr; #ifdef M_WRITABLE /* * HOT FIX/KLUDGE: * * If the mbuf we're about to send is not writable (because of * a cluster reference, for example) we'll need to make a copy * of it since this routine modifies the contents. * * If you have non-crappy network hardware that can transmit data * from the mbuf, rather than making a copy, this is gonna be a * problem. */ if (M_WRITABLE(m) == 0) { m0 = m_dup(m, M_NOWAIT); if (m0 != NULL) { FREE_MB_T(m); m = m0; *mpp = m; } else { error = ENOBUFS; FREE_MB_T(m); goto done; } } #endif #ifdef USE_INET6 if (fin->fin_v == 6) { /* * currently "to " and "to :ip#" are not supported * for IPv6 */ return (ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL)); } #endif hlen = fin->fin_hlen; ip = mtod(m0, struct ip *); ifp = NULL; /* * Route packet. */ bzero(&ro, sizeof (ro)); dst = (struct sockaddr_in *)&ro.ro_dst; dst->sin_family = AF_INET; dst->sin_addr = ip->ip_dst; dst->sin_len = sizeof(dst); gw = (const struct sockaddr *)dst; fr = fin->fin_fr; if ((fr != NULL) && !(fr->fr_flags & FR_KEEPSTATE) && (fdp != NULL) && (fdp->fd_type == FRD_DSTLIST)) { if (ipf_dstlist_select_node(fin, fdp->fd_ptr, NULL, &node) == 0) fdp = &node; } if (fdp != NULL) ifp = fdp->fd_ptr; else ifp = fin->fin_ifp; if ((ifp == NULL) && ((fr == NULL) || !(fr->fr_flags & FR_FASTROUTE))) { error = -2; goto bad; } if ((fdp != NULL) && (fdp->fd_ip.s_addr != 0)) dst->sin_addr = fdp->fd_ip; fibnum = M_GETFIB(m0); NET_EPOCH_ASSERT(); nh = fib4_lookup(fibnum, dst->sin_addr, 0, NHR_NONE, 0); if (nh == NULL) { if (in_localaddr(ip->ip_dst)) error = EHOSTUNREACH; else error = ENETUNREACH; goto bad; } if (ifp == NULL) ifp = nh->nh_ifp; if (nh->nh_flags & NHF_GATEWAY) { gw = &nh->gw_sa; ro.ro_flags |= RT_HAS_GW; } /* * For input packets which are being "fastrouted", they won't * go back through output filtering and miss their chance to get * NAT'd and counted. Duplicated packets aren't considered to be * part of the normal packet stream, so do not NAT them or pass * them through stateful checking, etc. */ if ((fdp != &fr->fr_dif) && (fin->fin_out == 0)) { sifp = fin->fin_ifp; fin->fin_ifp = ifp; fin->fin_out = 1; (void) ipf_acctpkt(fin, NULL); fin->fin_fr = NULL; if (!fr || !(fr->fr_flags & FR_RETMASK)) { u_32_t pass; (void) ipf_state_check(fin, &pass); } switch (ipf_nat_checkout(fin, NULL)) { case 0 : break; case 1 : ip->ip_sum = 0; break; case -1 : error = -1; goto bad; break; } fin->fin_ifp = sifp; fin->fin_out = 0; } else ip->ip_sum = 0; /* * If small enough for interface, can just send directly. */ if (ntohs(ip->ip_len) <= ifp->if_mtu) { if (!ip->ip_sum) ip->ip_sum = in_cksum(m, hlen); error = (*ifp->if_output)(ifp, m, gw, &ro); goto done; } /* * Too large for interface; fragment if possible. * Must be able to put at least 8 bytes per fragment. */ ip_off = ntohs(ip->ip_off); if (ip_off & IP_DF) { error = EMSGSIZE; goto bad; } len = (ifp->if_mtu - hlen) &~ 7; if (len < 8) { error = EMSGSIZE; goto bad; } { int mhlen, firstlen = len; struct mbuf **mnext = &m->m_act; /* * Loop through length of segment after first fragment, * make new header and copy data of each part and link onto chain. */ m0 = m; mhlen = sizeof (struct ip); for (off = hlen + len; off < ntohs(ip->ip_len); off += len) { #ifdef MGETHDR MGETHDR(m, M_NOWAIT, MT_HEADER); #else MGET(m, M_NOWAIT, MT_HEADER); #endif if (m == NULL) { m = m0; error = ENOBUFS; goto bad; } m->m_data += max_linkhdr; mhip = mtod(m, struct ip *); bcopy((char *)ip, (char *)mhip, sizeof(*ip)); if (hlen > sizeof (struct ip)) { mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip); IP_HL_A(mhip, mhlen >> 2); } m->m_len = mhlen; mhip->ip_off = ((off - hlen) >> 3) + ip_off; if (off + len >= ntohs(ip->ip_len)) len = ntohs(ip->ip_len) - off; else mhip->ip_off |= IP_MF; mhip->ip_len = htons((u_short)(len + mhlen)); *mnext = m; m->m_next = m_copym(m0, off, len, M_NOWAIT); if (m->m_next == 0) { error = ENOBUFS; /* ??? */ goto sendorfree; } m->m_pkthdr.len = mhlen + len; m->m_pkthdr.rcvif = NULL; mhip->ip_off = htons((u_short)mhip->ip_off); mhip->ip_sum = 0; mhip->ip_sum = in_cksum(m, mhlen); mnext = &m->m_act; } /* * Update first fragment by trimming what's been copied out * and updating header, then send each fragment (in order). */ m_adj(m0, hlen + firstlen - ip->ip_len); ip->ip_len = htons((u_short)(hlen + firstlen)); ip->ip_off = htons((u_short)IP_MF); ip->ip_sum = 0; ip->ip_sum = in_cksum(m0, hlen); sendorfree: for (m = m0; m; m = m0) { m0 = m->m_act; m->m_act = 0; if (error == 0) error = (*ifp->if_output)(ifp, m, gw, &ro); else FREE_MB_T(m); } } done: if (!error) V_ipfmain.ipf_frouteok[0]++; else V_ipfmain.ipf_frouteok[1]++; return (0); bad: if (error == EMSGSIZE) { sifp = fin->fin_ifp; code = fin->fin_icode; fin->fin_icode = ICMP_UNREACH_NEEDFRAG; fin->fin_ifp = ifp; (void) ipf_send_icmp_err(ICMP_UNREACH, fin, 1); fin->fin_ifp = sifp; fin->fin_icode = code; } FREE_MB_T(m); goto done; } int ipf_verifysrc(fr_info_t *fin) { struct nhop_object *nh; NET_EPOCH_ASSERT(); nh = fib4_lookup(RT_DEFAULT_FIB, fin->fin_src, 0, NHR_NONE, 0); if (nh == NULL) return (0); return (fin->fin_ifp == nh->nh_ifp); } /* * return the first IP Address associated with an interface */ int ipf_ifpaddr(ipf_main_softc_t *softc, int v, int atype, void *ifptr, i6addr_t *inp, i6addr_t *inpmask) { #ifdef USE_INET6 struct in6_addr *ia6 = NULL; #endif struct sockaddr *sock, *mask; struct sockaddr_in *sin; struct ifaddr *ifa; struct ifnet *ifp; if ((ifptr == NULL) || (ifptr == (void *)-1)) return (-1); sin = NULL; ifp = ifptr; if (v == 4) inp->in4.s_addr = 0; #ifdef USE_INET6 else if (v == 6) bzero((char *)inp, sizeof(*inp)); #endif ifa = CK_STAILQ_FIRST(&ifp->if_addrhead); sock = ifa->ifa_addr; while (sock != NULL && ifa != NULL) { sin = (struct sockaddr_in *)sock; if ((v == 4) && (sin->sin_family == AF_INET)) break; #ifdef USE_INET6 if ((v == 6) && (sin->sin_family == AF_INET6)) { ia6 = &((struct sockaddr_in6 *)sin)->sin6_addr; if (!IN6_IS_ADDR_LINKLOCAL(ia6) && !IN6_IS_ADDR_LOOPBACK(ia6)) break; } #endif ifa = CK_STAILQ_NEXT(ifa, ifa_link); if (ifa != NULL) sock = ifa->ifa_addr; } if (ifa == NULL || sin == NULL) return (-1); mask = ifa->ifa_netmask; if (atype == FRI_BROADCAST) sock = ifa->ifa_broadaddr; else if (atype == FRI_PEERADDR) sock = ifa->ifa_dstaddr; if (sock == NULL) return (-1); #ifdef USE_INET6 if (v == 6) { return (ipf_ifpfillv6addr(atype, (struct sockaddr_in6 *)sock, (struct sockaddr_in6 *)mask, inp, inpmask)); } #endif return (ipf_ifpfillv4addr(atype, (struct sockaddr_in *)sock, (struct sockaddr_in *)mask, &inp->in4, &inpmask->in4)); } u_32_t ipf_newisn(fr_info_t *fin) { u_32_t newiss; newiss = arc4random(); return (newiss); } int ipf_checkv4sum(fr_info_t *fin) { #ifdef CSUM_DATA_VALID int manual = 0; u_short sum; ip_t *ip; mb_t *m; if ((fin->fin_flx & FI_NOCKSUM) != 0) return (0); if ((fin->fin_flx & FI_SHORT) != 0) return (1); if (fin->fin_cksum != FI_CK_NEEDED) return (fin->fin_cksum > FI_CK_NEEDED) ? 0 : -1; m = fin->fin_m; if (m == NULL) { manual = 1; goto skipauto; } ip = fin->fin_ip; if ((m->m_pkthdr.csum_flags & (CSUM_IP_CHECKED|CSUM_IP_VALID)) == CSUM_IP_CHECKED) { fin->fin_cksum = FI_CK_BAD; fin->fin_flx |= FI_BAD; DT2(ipf_fi_bad_checkv4sum_csum_ip_checked, fr_info_t *, fin, u_int, m->m_pkthdr.csum_flags & (CSUM_IP_CHECKED|CSUM_IP_VALID)); return (-1); } if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) { /* Depending on the driver, UDP may have zero checksum */ if (fin->fin_p == IPPROTO_UDP && (fin->fin_flx & (FI_FRAG|FI_SHORT|FI_BAD)) == 0) { udphdr_t *udp = fin->fin_dp; if (udp->uh_sum == 0) { /* * we're good no matter what the hardware * checksum flags and csum_data say (handling * of csum_data for zero UDP checksum is not * consistent across all drivers) */ fin->fin_cksum = 1; return (0); } } if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) sum = m->m_pkthdr.csum_data; else sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, htonl(m->m_pkthdr.csum_data + fin->fin_dlen + fin->fin_p)); sum ^= 0xffff; if (sum != 0) { fin->fin_cksum = FI_CK_BAD; fin->fin_flx |= FI_BAD; DT2(ipf_fi_bad_checkv4sum_sum, fr_info_t *, fin, u_int, sum); } else { fin->fin_cksum = FI_CK_SUMOK; return (0); } } else { if (m->m_pkthdr.csum_flags == CSUM_DELAY_DATA) { fin->fin_cksum = FI_CK_L4FULL; return (0); } else if (m->m_pkthdr.csum_flags == CSUM_TCP || m->m_pkthdr.csum_flags == CSUM_UDP || m->m_pkthdr.csum_flags == CSUM_IP) { fin->fin_cksum = FI_CK_L4PART; return (0); } else { manual = 1; } } skipauto: if (manual != 0) { if (ipf_checkl4sum(fin) == -1) { fin->fin_flx |= FI_BAD; DT2(ipf_fi_bad_checkv4sum_manual, fr_info_t *, fin, u_int, manual); return (-1); } } #else if (ipf_checkl4sum(fin) == -1) { fin->fin_flx |= FI_BAD; DT2(ipf_fi_bad_checkv4sum_checkl4sum, fr_info_t *, fin, u_int, -1); return (-1); } #endif return (0); } #ifdef USE_INET6 int ipf_checkv6sum(fr_info_t *fin) { if ((fin->fin_flx & FI_NOCKSUM) != 0) { DT(ipf_checkv6sum_fi_nocksum); return (0); } if ((fin->fin_flx & FI_SHORT) != 0) { DT(ipf_checkv6sum_fi_short); return (1); } if (fin->fin_cksum != FI_CK_NEEDED) { DT(ipf_checkv6sum_fi_ck_needed); return (fin->fin_cksum > FI_CK_NEEDED) ? 0 : -1; } if (ipf_checkl4sum(fin) == -1) { fin->fin_flx |= FI_BAD; DT2(ipf_fi_bad_checkv6sum_checkl4sum, fr_info_t *, fin, u_int, -1); return (-1); } return (0); } #endif /* USE_INET6 */ size_t mbufchainlen(struct mbuf *m0) { size_t len; if ((m0->m_flags & M_PKTHDR) != 0) { len = m0->m_pkthdr.len; } else { struct mbuf *m; for (m = m0, len = 0; m != NULL; m = m->m_next) len += m->m_len; } return (len); } /* ------------------------------------------------------------------------ */ /* Function: ipf_pullup */ /* Returns: NULL == pullup failed, else pointer to protocol header */ /* Parameters: xmin(I)- pointer to buffer where data packet starts */ /* fin(I) - pointer to packet information */ /* len(I) - number of bytes to pullup */ /* */ /* Attempt to move at least len bytes (from the start of the buffer) into a */ /* single buffer for ease of access. Operating system native functions are */ /* used to manage buffers - if necessary. If the entire packet ends up in */ /* a single buffer, set the FI_COALESCE flag even though ipf_coalesce() has */ /* not been called. Both fin_ip and fin_dp are updated before exiting _IF_ */ /* and ONLY if the pullup succeeds. */ /* */ /* We assume that 'xmin' is a pointer to a buffer that is part of the chain */ /* of buffers that starts at *fin->fin_mp. */ /* ------------------------------------------------------------------------ */ ip_t * ipf_pullup(mb_t *xmin, fr_info_t *fin, int len) { int dpoff, ipoff; mb_t *m = xmin; ip_t *ip; if (m == NULL) return (NULL); ip = fin->fin_ip; if ((fin->fin_flx & FI_COALESCE) != 0) return (ip); ipoff = fin->fin_ipoff; if (fin->fin_dp != NULL) dpoff = (char *)fin->fin_dp - (char *)ip; else dpoff = 0; if (M_LEN(m) < len) { mb_t *n = *fin->fin_mp; /* * Assume that M_PKTHDR is set and just work with what is left * rather than check.. * Should not make any real difference, anyway. */ if (m != n) { /* * Record the mbuf that points to the mbuf that we're * about to go to work on so that we can update the * m_next appropriately later. */ for (; n->m_next != m; n = n->m_next) ; } else { n = NULL; } #ifdef MHLEN if (len > MHLEN) #else if (len > MLEN) #endif { #ifdef HAVE_M_PULLDOWN if (m_pulldown(m, 0, len, NULL) == NULL) m = NULL; #else FREE_MB_T(*fin->fin_mp); m = NULL; n = NULL; #endif } else { m = m_pullup(m, len); } if (n != NULL) n->m_next = m; if (m == NULL) { /* * When n is non-NULL, it indicates that m pointed to * a sub-chain (tail) of the mbuf and that the head * of this chain has not yet been free'd. */ if (n != NULL) { FREE_MB_T(*fin->fin_mp); } *fin->fin_mp = NULL; fin->fin_m = NULL; return (NULL); } if (n == NULL) *fin->fin_mp = m; while (M_LEN(m) == 0) { m = m->m_next; } fin->fin_m = m; ip = MTOD(m, ip_t *) + ipoff; fin->fin_ip = ip; if (fin->fin_dp != NULL) fin->fin_dp = (char *)fin->fin_ip + dpoff; if (fin->fin_fraghdr != NULL) fin->fin_fraghdr = (char *)ip + ((char *)fin->fin_fraghdr - (char *)fin->fin_ip); } if (len == fin->fin_plen) fin->fin_flx |= FI_COALESCE; return (ip); } int ipf_inject(fr_info_t *fin, mb_t *m) { struct epoch_tracker et; int error = 0; NET_EPOCH_ENTER(et); if (fin->fin_out == 0) { netisr_dispatch(NETISR_IP, m); } else { fin->fin_ip->ip_len = ntohs(fin->fin_ip->ip_len); fin->fin_ip->ip_off = ntohs(fin->fin_ip->ip_off); error = ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL); } NET_EPOCH_EXIT(et); return (error); } VNET_DEFINE_STATIC(pfil_hook_t, ipf_inet_hook); VNET_DEFINE_STATIC(pfil_hook_t, ipf_inet6_hook); #define V_ipf_inet_hook VNET(ipf_inet_hook) #define V_ipf_inet6_hook VNET(ipf_inet6_hook) int ipf_pfil_unhook(void) { pfil_remove_hook(V_ipf_inet_hook); #ifdef USE_INET6 pfil_remove_hook(V_ipf_inet6_hook); #endif return (0); } int ipf_pfil_hook(void) { int error, error6; struct pfil_hook_args pha = { .pa_version = PFIL_VERSION, .pa_flags = PFIL_IN | PFIL_OUT, .pa_modname = "ipfilter", .pa_rulname = "default-ip4", .pa_mbuf_chk = ipf_check_wrapper, .pa_type = PFIL_TYPE_IP4, }; V_ipf_inet_hook = pfil_add_hook(&pha); #ifdef USE_INET6 pha.pa_rulname = "default-ip6"; pha.pa_mbuf_chk = ipf_check_wrapper6; pha.pa_type = PFIL_TYPE_IP6; V_ipf_inet6_hook = pfil_add_hook(&pha); #endif struct pfil_link_args pla = { .pa_version = PFIL_VERSION, .pa_flags = PFIL_IN | PFIL_OUT | PFIL_HEADPTR | PFIL_HOOKPTR, .pa_head = V_inet_pfil_head, .pa_hook = V_ipf_inet_hook, }; error = pfil_link(&pla); error6 = 0; #ifdef USE_INET6 pla.pa_head = V_inet6_pfil_head; pla.pa_hook = V_ipf_inet6_hook; error6 = pfil_link(&pla); #endif if (error || error6) error = ENODEV; else error = 0; return (error); } void ipf_event_reg(void) { V_ipf_arrivetag = EVENTHANDLER_REGISTER(ifnet_arrival_event, \ ipf_ifevent, NULL, \ EVENTHANDLER_PRI_ANY); V_ipf_departtag = EVENTHANDLER_REGISTER(ifnet_departure_event, \ ipf_ifevent, NULL, \ EVENTHANDLER_PRI_ANY); #if 0 V_ipf_clonetag = EVENTHANDLER_REGISTER(if_clone_event, ipf_ifevent, \ NULL, EVENTHANDLER_PRI_ANY); #endif } void ipf_event_dereg(void) { if (V_ipf_arrivetag != NULL) { EVENTHANDLER_DEREGISTER(ifnet_arrival_event, V_ipf_arrivetag); } if (V_ipf_departtag != NULL) { EVENTHANDLER_DEREGISTER(ifnet_departure_event, V_ipf_departtag); } #if 0 if (V_ipf_clonetag != NULL) { EVENTHANDLER_DEREGISTER(if_clone_event, V_ipf_clonetag); } #endif } u_32_t ipf_random(void) { return (arc4random()); } u_int ipf_pcksum(fr_info_t *fin, int hlen, u_int sum) { struct mbuf *m; u_int sum2; int off; m = fin->fin_m; off = (char *)fin->fin_dp - (char *)fin->fin_ip; m->m_data += hlen; m->m_len -= hlen; sum2 = in_cksum(fin->fin_m, fin->fin_plen - off); m->m_len += hlen; m->m_data -= hlen; /* * Both sum and sum2 are partial sums, so combine them together. */ sum += ~sum2 & 0xffff; while (sum > 0xffff) sum = (sum & 0xffff) + (sum >> 16); sum2 = ~sum & 0xffff; return (sum2); } #ifdef USE_INET6 u_int ipf_pcksum6(struct mbuf *m, ip6_t *ip6, u_int32_t off, u_int32_t len) { #ifdef _KERNEL int sum; if (m->m_len < sizeof(struct ip6_hdr)) { return (0xffff); } sum = in6_cksum(m, ip6->ip6_nxt, off, len); return (sum); #else u_short *sp; u_int sum; sp = (u_short *)&ip6->ip6_src; sum = *sp++; /* ip6_src */ sum += *sp++; sum += *sp++; sum += *sp++; sum += *sp++; sum += *sp++; sum += *sp++; sum += *sp++; sum += *sp++; /* ip6_dst */ sum += *sp++; sum += *sp++; sum += *sp++; sum += *sp++; sum += *sp++; sum += *sp++; sum += *sp++; return (ipf_pcksum(fin, off, sum)); #endif } #endif void ipf_fbsd_kenv_get(ipf_main_softc_t *softc) { TUNABLE_INT_FETCH("net.inet.ipf.large_nat", &softc->ipf_large_nat); }