/* $FreeBSD$ */ /* * Copyright (C) 1993-2003 by Darren Reed. * * See the IPFILTER.LICENCE file for details on licencing. */ #if !defined(lint) static const char sccsid[] = "@(#)ip_fil.c 2.41 6/5/96 (C) 1993-2000 Darren Reed"; static const char rcsid[] = "@(#)$Id: ip_fil_freebsd.c,v 2.53.2.50 2007/09/20 12:51:50 darrenr Exp $"; #endif #if defined(KERNEL) || defined(_KERNEL) # undef KERNEL # undef _KERNEL # define KERNEL 1 # define _KERNEL 1 #endif #if defined(__FreeBSD_version) && (__FreeBSD_version >= 400000) && \ !defined(KLD_MODULE) && !defined(IPFILTER_LKM) # include "opt_inet6.h" #endif #if defined(__FreeBSD_version) && (__FreeBSD_version >= 440000) && \ !defined(KLD_MODULE) && !defined(IPFILTER_LKM) # include "opt_random_ip_id.h" #endif #include #if defined(__FreeBSD__) && !defined(__FreeBSD_version) # if defined(IPFILTER_LKM) # ifndef __FreeBSD_cc_version # include # else # if __FreeBSD_cc_version < 430000 # include # endif # endif # endif #endif #include #include #include #if __FreeBSD_version >= 220000 # include # include #else # include #endif #include #include #if (__FreeBSD_version >= 300000) # include #else # include #endif #if !defined(__hpux) # include #endif #include #include #if __FreeBSD_version >= 500043 # include #else # include #endif #if __FreeBSD_version >= 800044 # include #else #define V_path_mtu_discovery path_mtu_discovery #define V_ipforwarding ipforwarding #endif #include #if __FreeBSD_version >= 300000 # include # if __FreeBSD_version >= 500043 # include # endif # if !defined(IPFILTER_LKM) # include "opt_ipfilter.h" # endif #endif #include #include #include #include #include #include #include #if defined(__osf__) # include #endif #include #include #include #ifndef _KERNEL # include "netinet/ipf.h" #endif #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" #ifdef IPFILTER_SYNC #include "netinet/ip_sync.h" #endif #ifdef IPFILTER_SCAN #include "netinet/ip_scan.h" #endif #include "netinet/ip_pool.h" #if defined(__FreeBSD_version) && (__FreeBSD_version >= 300000) # include #endif #include #ifdef CSUM_DATA_VALID #include #endif extern int ip_optcopy __P((struct ip *, struct ip *)); #if (__FreeBSD_version > 460000) && (__FreeBSD_version < 800055) extern int path_mtu_discovery; #endif # ifdef IPFILTER_M_IPFILTER MALLOC_DEFINE(M_IPFILTER, "ipfilter", "IP Filter packet filter data structures"); # endif #if !defined(__osf__) extern struct protosw inetsw[]; #endif static int (*fr_savep) __P((ip_t *, int, void *, int, struct mbuf **)); static int fr_send_ip __P((fr_info_t *, mb_t *, mb_t **)); # ifdef USE_MUTEXES ipfmutex_t ipl_mutex, ipf_authmx, ipf_rw, ipf_stinsert; ipfmutex_t ipf_nat_new, ipf_natio, ipf_timeoutlock; ipfrwlock_t ipf_mutex, ipf_global, ipf_ipidfrag, ipf_frcache, ipf_tokens; ipfrwlock_t ipf_frag, ipf_state, ipf_nat, ipf_natfrag, ipf_auth; # endif int ipf_locks_done = 0; #if (__FreeBSD_version >= 300000) struct callout_handle fr_slowtimer_ch; #endif struct selinfo ipfselwait[IPL_LOGSIZE]; #if (__FreeBSD_version >= 500011) # include # if defined(NETBSD_PF) # include # if (__FreeBSD_version < 501108) # include # endif /* * We provide the fr_checkp name just to minimize changes later. */ int (*fr_checkp) __P((ip_t *ip, int hlen, void *ifp, int out, mb_t **mp)); # endif /* NETBSD_PF */ #endif /* __FreeBSD_version >= 500011 */ #if (__FreeBSD_version >= 502103) static eventhandler_tag ipf_arrivetag, ipf_departtag, ipf_clonetag; static void ipf_ifevent(void *arg); static void ipf_ifevent(arg) void *arg; { frsync(NULL); } #endif #if (__FreeBSD_version >= 501108) && defined(_KERNEL) static int fr_check_wrapper(void *arg, struct mbuf **mp, struct ifnet *ifp, int dir) { struct ip *ip = mtod(*mp, struct ip *); return fr_check(ip, ip->ip_hl << 2, ifp, (dir == PFIL_OUT), mp); } # ifdef USE_INET6 # include static int fr_check_wrapper6(void *arg, struct mbuf **mp, struct ifnet *ifp, int dir) { return (fr_check(mtod(*mp, struct ip *), sizeof(struct ip6_hdr), ifp, (dir == PFIL_OUT), mp)); } # endif #endif /* __FreeBSD_version >= 501108 */ #if defined(IPFILTER_LKM) int iplidentify(s) char *s; { if (strcmp(s, "ipl") == 0) return 1; return 0; } #endif /* IPFILTER_LKM */ int ipfattach() { #ifdef USE_SPL int s; #endif SPL_NET(s); if (fr_running > 0) { SPL_X(s); return EBUSY; } MUTEX_INIT(&ipf_rw, "ipf rw mutex"); MUTEX_INIT(&ipf_timeoutlock, "ipf timeout queue mutex"); RWLOCK_INIT(&ipf_ipidfrag, "ipf IP NAT-Frag rwlock"); RWLOCK_INIT(&ipf_tokens, "ipf token rwlock"); ipf_locks_done = 1; if (fr_initialise() < 0) { SPL_X(s); return EIO; } if (fr_checkp != fr_check) { fr_savep = fr_checkp; fr_checkp = fr_check; } bzero((char *)ipfselwait, sizeof(ipfselwait)); bzero((char *)frcache, sizeof(frcache)); fr_running = 1; if (fr_control_forwarding & 1) V_ipforwarding = 1; SPL_X(s); #if (__FreeBSD_version >= 300000) fr_slowtimer_ch = timeout(fr_slowtimer, NULL, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT); #else timeout(fr_slowtimer, NULL, (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT); #endif return 0; } /* * Disable the filter by removing the hooks from the IP input/output * stream. */ int ipfdetach() { #ifdef USE_SPL int s; #endif if (fr_control_forwarding & 2) V_ipforwarding = 0; SPL_NET(s); #if (__FreeBSD_version >= 300000) if (fr_slowtimer_ch.callout != NULL) untimeout(fr_slowtimer, NULL, fr_slowtimer_ch); bzero(&fr_slowtimer_ch, sizeof(fr_slowtimer_ch)); #else untimeout(fr_slowtimer, NULL); #endif /* FreeBSD */ #ifndef NETBSD_PF if (fr_checkp != NULL) fr_checkp = fr_savep; fr_savep = NULL; #endif fr_deinitialise(); fr_running = -2; (void) frflush(IPL_LOGIPF, 0, FR_INQUE|FR_OUTQUE|FR_INACTIVE); (void) frflush(IPL_LOGIPF, 0, FR_INQUE|FR_OUTQUE); if (ipf_locks_done == 1) { MUTEX_DESTROY(&ipf_timeoutlock); MUTEX_DESTROY(&ipf_rw); RW_DESTROY(&ipf_ipidfrag); RW_DESTROY(&ipf_tokens); ipf_locks_done = 0; } SPL_X(s); return 0; } /* * Filter ioctl interface. */ int iplioctl(dev, cmd, data, mode # if defined(_KERNEL) && ((BSD >= 199506) || (__FreeBSD_version >= 220000)) , p) # if (__FreeBSD_version >= 500024) struct thread *p; # if (__FreeBSD_version >= 500043) # define p_cred td_ucred # define p_uid td_ucred->cr_ruid # else # define p_cred t_proc->p_cred # define p_uid t_proc->p_cred->p_ruid # endif # else struct proc *p; # define p_uid p_cred->p_ruid # endif /* __FreeBSD_version >= 500024 */ # else ) # endif #if defined(_KERNEL) && (__FreeBSD_version >= 502116) struct cdev *dev; #else dev_t dev; #endif ioctlcmd_t cmd; caddr_t data; int mode; { int error = 0, unit = 0; SPL_INT(s); #if (BSD >= 199306) && defined(_KERNEL) # if (__FreeBSD_version >= 500034) if (securelevel_ge(p->p_cred, 3) && (mode & FWRITE)) # else if ((securelevel >= 3) && (mode & FWRITE)) # endif return EPERM; #endif unit = GET_MINOR(dev); if ((IPL_LOGMAX < unit) || (unit < 0)) return ENXIO; if (fr_running <= 0) { if (unit != IPL_LOGIPF) return EIO; if (cmd != SIOCIPFGETNEXT && cmd != SIOCIPFGET && cmd != SIOCIPFSET && cmd != SIOCFRENB && cmd != SIOCGETFS && cmd != SIOCGETFF) return EIO; } SPL_NET(s); error = fr_ioctlswitch(unit, data, cmd, mode, p->p_uid, p); if (error != -1) { SPL_X(s); return error; } SPL_X(s); return error; } #if 0 void fr_forgetifp(ifp) void *ifp; { register frentry_t *f; WRITE_ENTER(&ipf_mutex); for (f = ipacct[0][fr_active]; (f != NULL); f = f->fr_next) if (f->fr_ifa == ifp) f->fr_ifa = (void *)-1; for (f = ipacct[1][fr_active]; (f != NULL); f = f->fr_next) if (f->fr_ifa == ifp) f->fr_ifa = (void *)-1; for (f = ipfilter[0][fr_active]; (f != NULL); f = f->fr_next) if (f->fr_ifa == ifp) f->fr_ifa = (void *)-1; for (f = ipfilter[1][fr_active]; (f != NULL); f = f->fr_next) if (f->fr_ifa == ifp) f->fr_ifa = (void *)-1; #ifdef USE_INET6 for (f = ipacct6[0][fr_active]; (f != NULL); f = f->fr_next) if (f->fr_ifa == ifp) f->fr_ifa = (void *)-1; for (f = ipacct6[1][fr_active]; (f != NULL); f = f->fr_next) if (f->fr_ifa == ifp) f->fr_ifa = (void *)-1; for (f = ipfilter6[0][fr_active]; (f != NULL); f = f->fr_next) if (f->fr_ifa == ifp) f->fr_ifa = (void *)-1; for (f = ipfilter6[1][fr_active]; (f != NULL); f = f->fr_next) if (f->fr_ifa == ifp) f->fr_ifa = (void *)-1; #endif RWLOCK_EXIT(&ipf_mutex); fr_natsync(ifp); } #endif /* * routines below for saving IP headers to buffer */ int iplopen(dev, flags #if ((BSD >= 199506) || (__FreeBSD_version >= 220000)) && defined(_KERNEL) , devtype, p) int devtype; # if (__FreeBSD_version >= 500024) struct thread *p; # else struct proc *p; # endif /* __FreeBSD_version >= 500024 */ #else ) #endif #if defined(_KERNEL) && (__FreeBSD_version >= 502116) struct cdev *dev; #else dev_t dev; #endif int flags; { u_int min = GET_MINOR(dev); if (IPL_LOGMAX < min) min = ENXIO; else min = 0; return min; } int iplclose(dev, flags #if ((BSD >= 199506) || (__FreeBSD_version >= 220000)) && defined(_KERNEL) , devtype, p) int devtype; # if (__FreeBSD_version >= 500024) struct thread *p; # else struct proc *p; # endif /* __FreeBSD_version >= 500024 */ #else ) #endif #if defined(_KERNEL) && (__FreeBSD_version >= 502116) struct cdev *dev; #else dev_t dev; #endif int flags; { u_int min = GET_MINOR(dev); if (IPL_LOGMAX < min) min = ENXIO; else min = 0; return min; } /* * iplread/ipllog * both of these must operate with at least splnet() lest they be * called during packet processing and cause an inconsistancy to appear in * the filter lists. */ #if (BSD >= 199306) int iplread(dev, uio, ioflag) int ioflag; #else int iplread(dev, uio) #endif #if defined(_KERNEL) && (__FreeBSD_version >= 502116) struct cdev *dev; #else dev_t dev; #endif register struct uio *uio; { u_int xmin = GET_MINOR(dev); if (fr_running < 1) return EIO; if (xmin < 0) return ENXIO; # ifdef IPFILTER_SYNC if (xmin == IPL_LOGSYNC) return ipfsync_read(uio); # endif #ifdef IPFILTER_LOG return ipflog_read(xmin, uio); #else return ENXIO; #endif } /* * iplwrite * both of these must operate with at least splnet() lest they be * called during packet processing and cause an inconsistancy to appear in * the filter lists. */ #if (BSD >= 199306) int iplwrite(dev, uio, ioflag) int ioflag; #else int iplwrite(dev, uio) #endif #if defined(_KERNEL) && (__FreeBSD_version >= 502116) struct cdev *dev; #else dev_t dev; #endif register struct uio *uio; { if (fr_running < 1) return EIO; #ifdef IPFILTER_SYNC if (GET_MINOR(dev) == IPL_LOGSYNC) return ipfsync_write(uio); #endif return ENXIO; } /* * fr_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 fr_send_reset(fin) 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 (fr_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_DONTWAIT, MT_HEADER); #else MGET(m, M_DONTWAIT, MT_HEADER); #endif if (m == NULL) return -1; if (sizeof(*tcp2) + hlen > MLEN) { MCLGET(m, M_DONTWAIT); if ((m->m_flags & M_EXT) == 0) { FREE_MB_T(m); return -1; } } m->m_len = sizeof(*tcp2) + hlen; #if (BSD >= 199103) m->m_data += max_linkhdr; m->m_pkthdr.len = m->m_len; m->m_pkthdr.rcvif = (struct ifnet *)0; #endif 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->th_flags & TH_ACK) { tcp2->th_seq = tcp->th_ack; tcp2->th_flags = 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); tcp2->th_flags = TH_RST|TH_ACK; } TCP_X2_A(tcp2, 0); 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; ip6->ip6_dst = fin->fin_src6; tcp2->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(*ip6), sizeof(*tcp2)); return fr_send_ip(fin, m, &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 = hlen + sizeof(*tcp2); return fr_send_ip(fin, m, &m); } static int fr_send_ip(fin, m, mpp) fr_info_t *fin; mb_t *m, **mpp; { fr_info_t fnew; ip_t *ip, *oip; int hlen; ip = mtod(m, ip_t *); bzero((char *)&fnew, sizeof(fnew)); IP_V_A(ip, fin->fin_v); switch (fin->fin_v) { case 4 : fnew.fin_v = 4; oip = fin->fin_ip; IP_HL_A(ip, sizeof(*oip) >> 2); ip->ip_tos = oip->ip_tos; ip->ip_id = fin->fin_ip->ip_id; #if (__FreeBSD_version > 460000) ip->ip_off = V_path_mtu_discovery ? IP_DF : 0; #else ip->ip_off = 0; #endif ip->ip_ttl = V_ip_defttl; ip->ip_sum = 0; hlen = sizeof(*oip); break; #ifdef USE_INET6 case 6 : { ip6_t *ip6 = (ip6_t *)ip; ip6->ip6_vfc = 0x60; ip6->ip6_hlim = IPDEFTTL; fnew.fin_v = 6; hlen = sizeof(*ip6); break; } #endif default : return EINVAL; } #ifdef IPSEC 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 = mpp; fnew.fin_hlen = hlen; fnew.fin_dp = (char *)ip + hlen; (void) fr_makefrip(hlen, ip, &fnew); return fr_fastroute(m, mpp, &fnew, NULL); } int fr_send_icmp_err(type, fin, dst) 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; void *ifp; #ifdef USE_INET6 ip6_t *ip6; struct in6_addr dst6; #endif ip_t *ip, *ip2; if ((type < 0) || (type >= ICMP_MAXTYPE)) return -1; code = fin->fin_icode; #ifdef USE_INET6 if ((code < 0) || (code > sizeof(icmptoicmp6unreach)/sizeof(int))) return -1; #endif if (fr_checkl4sum(fin) == -1) return -1; #ifdef MGETHDR MGETHDR(m, M_DONTWAIT, MT_HEADER); #else MGET(m, M_DONTWAIT, MT_HEADER); #endif if (m == NULL) return -1; avail = MHLEN; xtra = 0; hlen = 0; ohlen = 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 (fr_ifpaddr(4, FRI_NORMAL, ifp, &dst4, NULL) == -1) { FREE_MB_T(m); return -1; } } else dst4.s_addr = fin->fin_daddr; hlen = sizeof(ip_t); ohlen = fin->fin_hlen; 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); type = icmptoicmp6types[type]; if (type == ICMP6_DST_UNREACH) code = icmptoicmp6unreach[code]; if (hlen + sizeof(*icmp) + max_linkhdr + fin->fin_plen > avail) { MCLGET(m, M_DONTWAIT); if ((m->m_flags & M_EXT) == 0) { FREE_MB_T(m); return -1; } avail = MCLBYTES; } xtra = MIN(fin->fin_plen, avail - hlen - sizeof(*icmp) - max_linkhdr); if (dst == 0) { if (fr_ifpaddr(6, FRI_NORMAL, ifp, (struct in_addr *)&dst6, NULL) == -1) { FREE_MB_T(m); return -1; } } else dst6 = fin->fin_dst6; } #endif else { FREE_MB_T(m); return -1; } iclen = hlen + sizeof(*icmp); 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 && ifp) icmp->icmp_nextmtu = htons(((struct ifnet *)ifp)->if_mtu); #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; ip6->ip6_dst = fin->fin_src6; 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 { ip2->ip_len = htons(ip2->ip_len); ip2->ip_off = htons(ip2->ip_off); 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 = iclen; ip->ip_p = IPPROTO_ICMP; } err = fr_send_ip(fin, m, &m); return err; } #if !defined(IPFILTER_LKM) && (__FreeBSD_version < 300000) # if (BSD < 199306) int iplinit __P((void)); int # else void iplinit __P((void)); void # endif iplinit() { if (ipfattach() != 0) printf("IP Filter failed to attach\n"); ip_init(); } #endif /* __FreeBSD_version < 300000 */ /* * m0 - pointer to mbuf where the IP packet starts * mpp - pointer to the mbuf pointer that is the start of the mbuf chain */ int fr_fastroute(m0, mpp, fin, fdp) mb_t *m0, **mpp; fr_info_t *fin; frdest_t *fdp; { register struct ip *ip, *mhip; register struct mbuf *m = *mpp; register struct route *ro; int len, off, error = 0, hlen, code; struct ifnet *ifp, *sifp; struct sockaddr_in *dst; struct route iproute; u_short ip_off; frentry_t *fr; ro = NULL; #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_DONTWAIT); if (m0 != 0) { 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 */ #if (__FreeBSD_version >= 490000) return ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL); #else return ip6_output(m0, NULL, NULL, 0, NULL, NULL); #endif } #endif hlen = fin->fin_hlen; ip = mtod(m0, struct ip *); /* * Route packet. */ ro = &iproute; bzero((caddr_t)ro, sizeof (*ro)); dst = (struct sockaddr_in *)&ro->ro_dst; dst->sin_family = AF_INET; dst->sin_addr = ip->ip_dst; fr = fin->fin_fr; if (fdp != NULL) ifp = fdp->fd_ifp; else ifp = fin->fin_ifp; if ((ifp == NULL) && (!fr || !(fr->fr_flags & FR_FASTROUTE))) { error = -2; goto bad; } if ((fdp != NULL) && (fdp->fd_ip.s_addr != 0)) dst->sin_addr = fdp->fd_ip; dst->sin_len = sizeof(*dst); in_rtalloc(ro, 0); if ((ifp == NULL) && (ro->ro_rt != NULL)) ifp = ro->ro_rt->rt_ifp; if ((ro->ro_rt == NULL) || (ifp == NULL)) { if (in_localaddr(ip->ip_dst)) error = EHOSTUNREACH; else error = ENETUNREACH; goto bad; } if (ro->ro_rt->rt_flags & RTF_GATEWAY) dst = (struct sockaddr_in *)ro->ro_rt->rt_gateway; if (ro->ro_rt) ro->ro_rt->rt_use++; /* * 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) fr_acctpkt(fin, NULL); fin->fin_fr = NULL; if (!fr || !(fr->fr_flags & FR_RETMASK)) { u_32_t pass; if (fr_checkstate(fin, &pass) != NULL) fr_statederef((ipstate_t **)&fin->fin_state); } switch (fr_checknatout(fin, NULL)) { case 0 : break; case 1 : fr_natderef((nat_t **)&fin->fin_nat); 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 (ip->ip_len <= ifp->if_mtu) { ip->ip_len = htons(ip->ip_len); ip->ip_off = htons(ip->ip_off); if (!ip->ip_sum) ip->ip_sum = in_cksum(m, hlen); error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst, 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 < ip->ip_len; off += len) { #ifdef MGETHDR MGETHDR(m, M_DONTWAIT, MT_HEADER); #else MGET(m, M_DONTWAIT, MT_HEADER); #endif if (m == 0) { 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 >= ip->ip_len) len = ip->ip_len - off; else mhip->ip_off |= IP_MF; mhip->ip_len = htons((u_short)(len + mhlen)); *mnext = m; m->m_next = m_copy(m0, off, len); 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, (struct sockaddr *)dst, ro); else FREE_MB_T(m); } } done: if (!error) fr_frouteok[0]++; else fr_frouteok[1]++; if ((ro != NULL) && (ro->ro_rt != NULL)) { RTFREE(ro->ro_rt); } *mpp = NULL; 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) fr_send_icmp_err(ICMP_UNREACH, fin, 1); fin->fin_ifp = sifp; fin->fin_icode = code; } FREE_MB_T(m); goto done; } int fr_verifysrc(fin) fr_info_t *fin; { struct sockaddr_in *dst; struct route iproute; bzero((char *)&iproute, sizeof(iproute)); dst = (struct sockaddr_in *)&iproute.ro_dst; dst->sin_len = sizeof(*dst); dst->sin_family = AF_INET; dst->sin_addr = fin->fin_src; in_rtalloc(&iproute, 0); if (iproute.ro_rt == NULL) return 0; return (fin->fin_ifp == iproute.ro_rt->rt_ifp); } /* * return the first IP Address associated with an interface */ int fr_ifpaddr(v, atype, ifptr, inp, inpmask) int v, atype; void *ifptr; struct in_addr *inp, *inpmask; { #ifdef USE_INET6 struct in6_addr *inp6 = 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->s_addr = 0; #ifdef USE_INET6 else if (v == 6) bzero((char *)inp, sizeof(struct in6_addr)); #endif #if (__FreeBSD_version >= 300000) ifa = TAILQ_FIRST(&ifp->if_addrhead); #else ifa = ifp->if_addrlist; #endif /* __FreeBSD_version >= 300000 */ 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)) { inp6 = &((struct sockaddr_in6 *)sin)->sin6_addr; if (!IN6_IS_ADDR_LINKLOCAL(inp6) && !IN6_IS_ADDR_LOOPBACK(inp6)) break; } #endif #if (__FreeBSD_version >= 300000) ifa = TAILQ_NEXT(ifa, ifa_link); #else ifa = ifa->ifa_next; #endif /* __FreeBSD_version >= 300000 */ 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 fr_ifpfillv6addr(atype, (struct sockaddr_in6 *)sock, (struct sockaddr_in6 *)mask, inp, inpmask); } #endif return fr_ifpfillv4addr(atype, (struct sockaddr_in *)sock, (struct sockaddr_in *)mask, inp, inpmask); } u_32_t fr_newisn(fin) fr_info_t *fin; { u_32_t newiss; #if (__FreeBSD_version >= 400000) newiss = arc4random(); #else static iss_seq_off = 0; u_char hash[16]; MD5_CTX ctx; /* * Compute the base value of the ISS. It is a hash * of (saddr, sport, daddr, dport, secret). */ MD5Init(&ctx); MD5Update(&ctx, (u_char *) &fin->fin_fi.fi_src, sizeof(fin->fin_fi.fi_src)); MD5Update(&ctx, (u_char *) &fin->fin_fi.fi_dst, sizeof(fin->fin_fi.fi_dst)); MD5Update(&ctx, (u_char *) &fin->fin_dat, sizeof(fin->fin_dat)); MD5Update(&ctx, ipf_iss_secret, sizeof(ipf_iss_secret)); MD5Final(hash, &ctx); memcpy(&newiss, hash, sizeof(newiss)); /* * Now increment our "timer", and add it in to * the computed value. * * XXX Use `addin'? * XXX TCP_ISSINCR too large to use? */ iss_seq_off += 0x00010000; newiss += iss_seq_off; #endif return newiss; } /* ------------------------------------------------------------------------ */ /* Function: fr_nextipid */ /* Returns: int - 0 == success, -1 == error (packet should be droppped) */ /* Parameters: fin(I) - pointer to packet information */ /* */ /* Returns the next IPv4 ID to use for this packet. */ /* ------------------------------------------------------------------------ */ u_short fr_nextipid(fin) fr_info_t *fin; { #ifndef RANDOM_IP_ID static u_short ipid = 0; u_short id; MUTEX_ENTER(&ipf_rw); id = ipid++; MUTEX_EXIT(&ipf_rw); #else u_short id; id = ip_randomid(); #endif return id; } INLINE void fr_checkv4sum(fin) 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; if (fin->fin_cksum != 0) return; m = fin->fin_m; if (m == NULL) { manual = 1; goto skipauto; } ip = fin->fin_ip; if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) { 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_ip->ip_len + fin->fin_p)); sum ^= 0xffff; if (sum != 0) { fin->fin_flx |= FI_BAD; fin->fin_cksum = -1; } else { fin->fin_cksum = 1; } } else manual = 1; skipauto: # ifdef IPFILTER_CKSUM if (manual != 0) if (fr_checkl4sum(fin) == -1) fin->fin_flx |= FI_BAD; # else ; # endif #else # ifdef IPFILTER_CKSUM if (fr_checkl4sum(fin) == -1) fin->fin_flx |= FI_BAD; # endif #endif } #ifdef USE_INET6 INLINE void fr_checkv6sum(fin) fr_info_t *fin; { # ifdef IPFILTER_CKSUM if (fr_checkl4sum(fin) == -1) fin->fin_flx |= FI_BAD; # endif } #endif /* USE_INET6 */ size_t mbufchainlen(m0) 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: fr_pullup */ /* Returns: NULL == pullup failed, else pointer to protocol header */ /* Parameters: m(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 fr_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 'min' is a pointer to a buffer that is part of the chain */ /* of buffers that starts at *fin->fin_mp. */ /* ------------------------------------------------------------------------ */ void *fr_pullup(min, fin, len) mb_t *min; fr_info_t *fin; int len; { int out = fin->fin_out, dpoff, ipoff; mb_t *m = min; char *ip; if (m == NULL) return NULL; ip = (char *)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) { #ifdef MHLEN /* * Assume that M_PKTHDR is set and just work with what is left * rather than check.. * Should not make any real difference, anyway. */ 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; #endif } else { m = m_pullup(m, len); } *fin->fin_mp = m; if (m == NULL) { fin->fin_m = NULL; ATOMIC_INCL(frstats[out].fr_pull[1]); return NULL; } while (M_LEN(m) == 0) { m = m->m_next; } fin->fin_m = m; ip = MTOD(m, char *) + ipoff; } ATOMIC_INCL(frstats[out].fr_pull[0]); fin->fin_ip = (ip_t *)ip; if (fin->fin_dp != NULL) fin->fin_dp = (char *)fin->fin_ip + dpoff; if (len == fin->fin_plen) fin->fin_flx |= FI_COALESCE; return ip; } int ipf_inject(fin, m) fr_info_t *fin; mb_t *m; { int error = 0; if (fin->fin_out == 0) { #if (__FreeBSD_version >= 501000) netisr_dispatch(NETISR_IP, m); #else struct ifqueue *ifq; ifq = &ipintrq; # ifdef _IF_QFULL if (_IF_QFULL(ifq)) # else if (IF_QFULL(ifq)) # endif { # ifdef _IF_DROP _IF_DROP(ifq); # else IF_DROP(ifq); # endif FREE_MB_T(m); error = ENOBUFS; } else { IF_ENQUEUE(ifq, m); } #endif } else { fin->fin_ip->ip_len = ntohs(fin->fin_ip->ip_len); fin->fin_ip->ip_off = ntohs(fin->fin_ip->ip_off); #if (__FreeBSD_version >= 470102) error = ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL); #else error = ip_output(m, NULL, NULL, IP_FORWARDING, NULL); #endif } return error; } int ipf_pfil_unhook(void) { #if defined(NETBSD_PF) && (__FreeBSD_version >= 500011) # if __FreeBSD_version >= 501108 struct pfil_head *ph_inet; # ifdef USE_INET6 struct pfil_head *ph_inet6; # endif # endif #endif #ifdef NETBSD_PF # if (__FreeBSD_version >= 500011) # if (__FreeBSD_version >= 501108) ph_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET); if (ph_inet != NULL) pfil_remove_hook((void *)fr_check_wrapper, NULL, PFIL_IN|PFIL_OUT|PFIL_WAITOK, ph_inet); # else pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT|PFIL_WAITOK, &inetsw[ip_protox[IPPROTO_IP]].pr_pfh); # endif # else pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT|PFIL_WAITOK); # endif # ifdef USE_INET6 # if (__FreeBSD_version >= 501108) ph_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6); if (ph_inet6 != NULL) pfil_remove_hook((void *)fr_check_wrapper6, NULL, PFIL_IN|PFIL_OUT|PFIL_WAITOK, ph_inet6); # else pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT|PFIL_WAITOK, &inet6sw[ip6_protox[IPPROTO_IPV6]].pr_pfh); # endif # endif #endif return (0); } int ipf_pfil_hook(void) { #if defined(NETBSD_PF) && (__FreeBSD_version >= 500011) # if __FreeBSD_version >= 501108 struct pfil_head *ph_inet; # ifdef USE_INET6 struct pfil_head *ph_inet6; # endif # endif #endif # ifdef NETBSD_PF # if __FreeBSD_version >= 500011 # if __FreeBSD_version >= 501108 ph_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET); # ifdef USE_INET6 ph_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6); # endif if (ph_inet == NULL # ifdef USE_INET6 && ph_inet6 == NULL # endif ) return ENODEV; if (ph_inet != NULL) pfil_add_hook((void *)fr_check_wrapper, NULL, PFIL_IN|PFIL_OUT|PFIL_WAITOK, ph_inet); # else pfil_add_hook((void *)fr_check, PFIL_IN|PFIL_OUT|PFIL_WAITOK, &inetsw[ip_protox[IPPROTO_IP]].pr_pfh); # endif # else pfil_add_hook((void *)fr_check, PFIL_IN|PFIL_OUT|PFIL_WAITOK); # endif # ifdef USE_INET6 # if __FreeBSD_version >= 501108 if (ph_inet6 != NULL) pfil_add_hook((void *)fr_check_wrapper6, NULL, PFIL_IN|PFIL_OUT|PFIL_WAITOK, ph_inet6); # else pfil_add_hook((void *)fr_check, PFIL_IN|PFIL_OUT|PFIL_WAITOK, &inet6sw[ip6_protox[IPPROTO_IPV6]].pr_pfh); # endif # endif # endif return (0); } void ipf_event_reg(void) { #if (__FreeBSD_version >= 502103) ipf_arrivetag = EVENTHANDLER_REGISTER(ifnet_arrival_event, \ ipf_ifevent, NULL, \ EVENTHANDLER_PRI_ANY); ipf_departtag = EVENTHANDLER_REGISTER(ifnet_departure_event, \ ipf_ifevent, NULL, \ EVENTHANDLER_PRI_ANY); ipf_clonetag = EVENTHANDLER_REGISTER(if_clone_event, ipf_ifevent, \ NULL, EVENTHANDLER_PRI_ANY); #endif } void ipf_event_dereg(void) { #if (__FreeBSD_version >= 502103) if (ipf_arrivetag != NULL) { EVENTHANDLER_DEREGISTER(ifnet_arrival_event, ipf_arrivetag); } if (ipf_departtag != NULL) { EVENTHANDLER_DEREGISTER(ifnet_departure_event, ipf_departtag); } if (ipf_clonetag != NULL) { EVENTHANDLER_DEREGISTER(if_clone_event, ipf_clonetag); } #endif }