/* $OpenBSD: ip_fil.c,v 1.37 2000/09/07 19:45:04 art Exp $ */ /* * Copyright (C) 1993-1998 by Darren Reed. * * Redistribution and use in source and binary forms are permitted * provided that this notice is preserved and due credit is given * to the original author and the contributors. */ #if !defined(lint) static const char sccsid[] = "@(#)ip_fil.c 2.41 6/5/96 (C) 1993-1995 Darren Reed"; static const char rcsid[] = "@(#)$IPFilter: ip_fil.c,v 2.4.2.22 2000/07/08 02:43:47 darrenr Exp $"; #endif #ifndef SOLARIS #define SOLARIS (defined(sun) && (defined(__svr4__) || defined(__SVR4))) #endif #if defined(KERNEL) && !defined(_KERNEL) # define _KERNEL #endif #include #if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \ defined(_KERNEL) # include "opt_ipfilter_log.h" #endif #ifdef __FreeBSD__ # if defined(_KERNEL) && !defined(IPFILTER_LKM) # include # else # include # endif #endif #ifndef _KERNEL # include # include # include # include # include #endif #include #include #include #if __FreeBSD_version >= 220000 && defined(_KERNEL) # include # include #else # include #endif #include #ifdef _KERNEL # include #endif #include #if !SOLARIS # if (NetBSD > 199609) || (OpenBSD > 199603) || (__FreeBSD_version >= 300000) # include # else # include # endif # include #else # include #endif #include #include #include #ifdef sun # include #endif #if __FreeBSD_version >= 300000 # include # if defined(_KERNEL) && !defined(IPFILTER_LKM) # include "opt_ipfilter.h" # endif #endif #ifdef __sgi #include # ifdef IFF_DRVRLOCK /* IRIX6 */ #include # endif #endif #include #include #if !(defined(__sgi) && !defined(IFF_DRVRLOCK)) /* IRIX < 6 */ # include #endif #include #include #include #include #include #include #include #ifndef _KERNEL # include # include #endif #include #include #include #include #include #include #include #if defined(__FreeBSD_version) && (__FreeBSD_version >= 300000) # include #endif #ifndef MIN # define MIN(a,b) (((a)<(b))?(a):(b)) #endif #if !SOLARIS && defined(_KERNEL) && !defined(__sgi) # include extern int ip_optcopy __P((struct ip *, struct ip *)); #endif extern struct protosw inetsw[]; #ifndef _KERNEL # include "ipt.h" static struct ifnet **ifneta = NULL; static int nifs = 0; #else # if (BSD < 199306) || defined(__sgi) extern int tcp_ttl; # endif #endif # if defined (__OpenBSD__) int ipl_unreach = ICMP_UNREACH_FILTER_PROHIB; # else int ipl_unreach = ICMP_UNREACH_FILTER; # endif u_long ipl_frouteok[2] = {0, 0}; static void frzerostats __P((caddr_t)); #if defined(__NetBSD__) || defined(__OpenBSD__) static int frrequest __P((int, u_long, caddr_t, int)); #else static int frrequest __P((int, int, caddr_t, int)); #endif #ifdef _KERNEL static int (*fr_savep) __P((ip_t *, int, void *, int, struct mbuf **)); static int send_ip __P((ip_t *, fr_info_t *, struct mbuf *)); # ifdef __sgi extern kmutex_t ipf_rw; extern KRWLOCK_T ipf_mutex; # endif #else int ipllog __P((void)); void init_ifp __P((void)); # ifdef __sgi static int no_output __P((struct ifnet *, struct mbuf *, struct sockaddr *)); static int write_output __P((struct ifnet *, struct mbuf *, struct sockaddr *)); # else static int no_output __P((struct ifnet *, struct mbuf *, struct sockaddr *, struct rtentry *)); static int write_output __P((struct ifnet *, struct mbuf *, struct sockaddr *, struct rtentry *)); # endif #endif int fr_running = 0; #if (__FreeBSD_version >= 300000) && defined(_KERNEL) struct callout_handle ipfr_slowtimer_ch; #endif #ifdef __OpenBSD__ #include struct timeout ipfr_slowtimer_to; #endif #if (_BSDI_VERSION >= 199510) && defined(_KERNEL) # include # include struct cfdriver iplcd = { NULL, "ipl", NULL, NULL, DV_DULL, 0 }; struct devsw iplsw = { &iplcd, iplopen, iplclose, iplread, nowrite, iplioctl, noselect, nommap, nostrat, nodump, nopsize, 0, nostop }; #endif /* _BSDI_VERSION >= 199510 && _KERNEL */ #if defined(__NetBSD__) || defined(__OpenBSD__) || (_BSDI_VERSION >= 199701) # include # if defined(NETBSD_PF) # include /* * 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 /* __NetBSD__ */ #ifdef _KERNEL # if defined(IPFILTER_LKM) && !defined(__sgi) int iplidentify(s) char *s; { if (strcmp(s, "ipl") == 0) return 1; return 0; } # endif /* IPFILTER_LKM */ /* * Try to detect the case when compiling for NetBSD with pseudo-device */ # if defined(__NetBSD__) && defined(PFIL_HOOKS) void ipfilterattach(count) int count; { if (iplattach() != 0) printf("IP Filter failed to attach\n"); } # endif int iplattach() { char *defpass; int s; # if defined(__sgi) || (defined(NETBSD_PF) && (__NetBSD_Version__ >= 104200000)) int error = 0; # endif SPL_NET(s); if (fr_running || (fr_checkp == fr_check)) { printf("IP Filter: already initialized\n"); SPL_X(s); return EBUSY; } # ifdef IPFILTER_LOG ipflog_init(); # endif if (nat_init() == -1) return -1; if (fr_stateinit() == -1) return -1; if (appr_init() == -1) return -1; # ifdef NETBSD_PF # if __NetBSD_Version__ >= 104200000 error = pfil_add_hook((void *)fr_check, PFIL_IN|PFIL_OUT, &inetsw[ip_protox[IPPROTO_IP]].pr_pfh); if (error) { appr_unload(); ip_natunload(); fr_stateunload(); return error; } # else pfil_add_hook((void *)fr_check, PFIL_IN|PFIL_OUT); # endif # endif # ifdef __sgi error = ipfilter_sgi_attach(); if (error) { SPL_X(s); appr_unload(); ip_natunload(); fr_stateunload(); return error; } # endif bzero((char *)frcache, sizeof(frcache)); fr_savep = fr_checkp; fr_checkp = fr_check; fr_running = 1; SPL_X(s); if (fr_pass & FR_PASS) defpass = "pass"; else if (fr_pass & FR_BLOCK) defpass = "block"; else defpass = "no-match -> block"; #if !defined(__OpenBSD__) printf("IP Filter: initialized. Default = %s all, Logging = %s\n", defpass, # ifdef IPFILTER_LOG "enabled"); # else "disabled"); # endif printf("%s\n", ipfilter_version); #endif #ifdef _KERNEL # if (__FreeBSD_version >= 300000) && defined(_KERNEL) ipfr_slowtimer_ch = timeout(ipfr_slowtimer, NULL, hz/2); # elif defined(__OpenBSD__) timeout_set(&ipfr_slowtimer_to, ipfr_slowtimer, NULL); timeout_add(&ipfr_slowtimer_to, hz/2); #else timeout(ipfr_slowtimer, NULL, hz/2); # endif #endif return 0; } /* * Disable the filter by removing the hooks from the IP input/output * stream. */ int ipldetach() { int s, i = FR_INQUE|FR_OUTQUE; #if defined(NETBSD_PF) && (__NetBSD_Version__ >= 104200000) int error = 0; #endif #ifdef _KERNEL # if (__FreeBSD_version >= 300000) untimeout(ipfr_slowtimer, NULL, ipfr_slowtimer_ch); # elif defined(__OpenBSD__) timeout_del(&ipfr_slowtimer_to); # else # ifdef __sgi untimeout(ipfr_slowtimer); # else untimeout(ipfr_slowtimer, NULL); # endif # endif #endif SPL_NET(s); if (!fr_running) { printf("IP Filter: not initialized\n"); SPL_X(s); return 0; } fr_checkp = fr_savep; i = frflush(IPL_LOGIPF, i); fr_running = 0; # ifdef NETBSD_PF # if __NetBSD_Version__ >= 104200000 error = pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT, &inetsw[ip_protox[IPPROTO_IP]].pr_pfh); if (error) return error; # else pfil_remove_hook((void *)fr_check, PFIL_IN|PFIL_OUT); # endif # endif # ifdef __sgi ipfilter_sgi_detach(); # endif appr_unload(); ipfr_unload(); ip_natunload(); fr_stateunload(); fr_authunload(); SPL_X(s); return 0; } #endif /* _KERNEL */ static void frzerostats(data) caddr_t data; { friostat_t fio; bcopy((char *)frstats, (char *)fio.f_st, sizeof(struct filterstats) * 2); fio.f_fin[0] = ipfilter[0][0]; fio.f_fin[1] = ipfilter[0][1]; fio.f_fout[0] = ipfilter[1][0]; fio.f_fout[1] = ipfilter[1][1]; fio.f_acctin[0] = ipacct[0][0]; fio.f_acctin[1] = ipacct[0][1]; fio.f_acctout[0] = ipacct[1][0]; fio.f_acctout[1] = ipacct[1][1]; fio.f_active = fr_active; fio.f_froute[0] = ipl_frouteok[0]; fio.f_froute[1] = ipl_frouteok[1]; IWCOPY((caddr_t)&fio, data, sizeof(fio)); bzero((char *)frstats, sizeof(*frstats) * 2); } /* * Filter ioctl interface. */ #ifdef __sgi int IPL_EXTERN(ioctl)(dev_t dev, int cmd, caddr_t data, int mode # ifdef _KERNEL , cred_t *cp, int *rp # endif ) #else int IPL_EXTERN(ioctl)(dev, cmd, data, mode #if ((_BSDI_VERSION >= 199510) || (BSD >= 199506) || (NetBSD >= 199511) || \ (__FreeBSD_version >= 220000) || defined(__OpenBSD__)) && defined(_KERNEL) , p) struct proc *p; #else ) #endif dev_t dev; #if defined(__NetBSD__) || defined(__OpenBSD__) || \ (_BSDI_VERSION >= 199701) || (__FreeBSD_version >= 300000) u_long cmd; #else int cmd; #endif caddr_t data; int mode; #endif /* __sgi */ { #if defined(_KERNEL) && !SOLARIS int s; #endif int error = 0, unit = 0, tmp; #if (BSD >= 199306) && defined(_KERNEL) if ((securelevel >= 2) && (mode & FWRITE)) return EPERM; #endif #ifdef _KERNEL unit = GET_MINOR(dev); if ((IPL_LOGMAX < unit) || (unit < 0)) return ENXIO; # if defined(__OpenBSD__) /* Prevent IPF and NAT changes when securelevel > 1 */ if (securelevel > 1) { switch (cmd) { # ifndef IPFILTER_LKM case SIOCFRENB: # endif case SIOCSETFF: case SIOCADAFR: case SIOCADIFR: case SIOCINAFR: case SIOCINIFR: case SIOCRMAFR: case SIOCRMIFR: case SIOCZRLST: case SIOCSWAPA: case SIOCFRZST: case SIOCIPFFL: # ifdef IPFILTER_LOG case SIOCIPFFB: # endif case SIOCADNAT: case SIOCRMNAT: case SIOCFLNAT: case SIOCCNATL: return EPERM; } } # endif /* OpenBSD */ #else /* _KERNEL */ unit = dev; #endif SPL_NET(s); if (unit == IPL_LOGNAT) { if (fr_running) error = nat_ioctl(data, cmd, mode); else error = EIO; SPL_X(s); return error; } if (unit == IPL_LOGSTATE) { if (fr_running) error = fr_state_ioctl(data, cmd, mode); else error = EIO; SPL_X(s); return error; } switch (cmd) { case FIONREAD : #ifdef IPFILTER_LOG IWCOPY((caddr_t)&iplused[IPL_LOGIPF], (caddr_t)data, sizeof(iplused[IPL_LOGIPF])); #endif break; #if !defined(IPFILTER_LKM) && defined(_KERNEL) case SIOCFRENB : { u_int enable; if (!(mode & FWRITE)) error = EPERM; else { IRCOPY(data, (caddr_t)&enable, sizeof(enable)); if (enable) error = iplattach(); else error = ipldetach(); } break; } #endif case SIOCSETFF : if (!(mode & FWRITE)) error = EPERM; else IRCOPY(data, (caddr_t)&fr_flags, sizeof(fr_flags)); break; case SIOCGETFF : IWCOPY((caddr_t)&fr_flags, data, sizeof(fr_flags)); break; case SIOCINAFR : case SIOCRMAFR : case SIOCADAFR : case SIOCZRLST : if (!(mode & FWRITE)) error = EPERM; else error = frrequest(unit, cmd, data, fr_active); break; case SIOCINIFR : case SIOCRMIFR : case SIOCADIFR : if (!(mode & FWRITE)) error = EPERM; else error = frrequest(unit, cmd, data, 1 - fr_active); break; case SIOCSWAPA : if (!(mode & FWRITE)) error = EPERM; else { bzero((char *)frcache, sizeof(frcache[0]) * 2); *(u_int *)data = fr_active; fr_active = 1 - fr_active; } break; case SIOCGETFS : { struct friostat fio; bcopy((char *)frstats, (char *)fio.f_st, sizeof(struct filterstats) * 2); fio.f_fin[0] = ipfilter[0][0]; fio.f_fin[1] = ipfilter[0][1]; fio.f_fout[0] = ipfilter[1][0]; fio.f_fout[1] = ipfilter[1][1]; fio.f_acctin[0] = ipacct[0][0]; fio.f_acctin[1] = ipacct[0][1]; fio.f_acctout[0] = ipacct[1][0]; fio.f_acctout[1] = ipacct[1][1]; fio.f_auth = ipauth; fio.f_active = fr_active; fio.f_froute[0] = ipl_frouteok[0]; fio.f_froute[1] = ipl_frouteok[1]; fio.f_running = fr_running; fio.f_groups[0][0] = ipfgroups[0][0]; fio.f_groups[0][1] = ipfgroups[0][1]; fio.f_groups[1][0] = ipfgroups[1][0]; fio.f_groups[1][1] = ipfgroups[1][1]; fio.f_groups[2][0] = ipfgroups[2][0]; fio.f_groups[2][1] = ipfgroups[2][1]; #ifdef IPFILTER_LOG fio.f_logging = 1; #else fio.f_logging = 0; #endif fio.f_defpass = fr_pass; strncpy(fio.f_version, ipfilter_version, sizeof(fio.f_version)); IWCOPY((caddr_t)&fio, data, sizeof(fio)); break; } case SIOCFRZST : if (!(mode & FWRITE)) error = EPERM; else frzerostats(data); break; case SIOCIPFFL : if (!(mode & FWRITE)) error = EPERM; else { IRCOPY(data, (caddr_t)&tmp, sizeof(tmp)); tmp = frflush(unit, tmp); IWCOPY((caddr_t)&tmp, data, sizeof(tmp)); } break; #ifdef IPFILTER_LOG case SIOCIPFFB : if (!(mode & FWRITE)) error = EPERM; else *(int *)data = ipflog_clear(unit); break; #endif /* IPFILTER_LOG */ case SIOCGFRST : IWCOPY((caddr_t)ipfr_fragstats(), data, sizeof(ipfrstat_t)); break; case SIOCAUTHW : case SIOCAUTHR : if (!(mode & FWRITE)) { error = EPERM; break; } case SIOCATHST : error = fr_auth_ioctl(data, cmd, NULL, NULL); break; case SIOCFRSYN : if (!(mode & FWRITE)) error = EPERM; else { #if defined(_KERNEL) && defined(__sgi) ipfsync(); #endif frsync(); } break; default : error = EINVAL; break; } SPL_X(s); return error; } 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; RWLOCK_EXIT(&ipf_mutex); ip_natsync(ifp); } static int frrequest(unit, req, data, set) int unit; #if defined(__NetBSD__) || defined(__OpenBSD__) u_long req; #else int req; #endif int set; caddr_t data; { register frentry_t *fp, *f, **fprev; register frentry_t **ftail; frentry_t frd; frdest_t *fdp; frgroup_t *fg = NULL; int error = 0, in; u_int group; fp = &frd; IRCOPY(data, (caddr_t)fp, sizeof(*fp)); fp->fr_ref = 0; /* * Check that the group number does exist and that if a head group * has been specified, doesn't exist. */ if ((req != SIOCZRLST) && fp->fr_grhead && fr_findgroup((u_int)fp->fr_grhead, fp->fr_flags, unit, set, NULL)) return EEXIST; if ((req != SIOCZRLST) && fp->fr_group && !fr_findgroup((u_int)fp->fr_group, fp->fr_flags, unit, set, NULL)) return ESRCH; in = (fp->fr_flags & FR_INQUE) ? 0 : 1; if (unit == IPL_LOGAUTH) ftail = fprev = &ipauth; else if (fp->fr_flags & FR_ACCOUNT) ftail = fprev = &ipacct[in][set]; else if (fp->fr_flags & (FR_OUTQUE|FR_INQUE)) ftail = fprev = &ipfilter[in][set]; else return ESRCH; if ((group = fp->fr_group)) { if (!(fg = fr_findgroup(group, fp->fr_flags, unit, set, NULL))) return ESRCH; ftail = fprev = fg->fg_start; } bzero((char *)frcache, sizeof(frcache[0]) * 2); if (*fp->fr_ifname) { fp->fr_ifa = GETUNIT(fp->fr_ifname); if (!fp->fr_ifa) fp->fr_ifa = (void *)-1; } #if BSD >= 199306 if (*fp->fr_oifname) { fp->fr_oifa = GETUNIT(fp->fr_oifname); if (!fp->fr_oifa) fp->fr_oifa = (void *)-1; } #endif fdp = &fp->fr_dif; fp->fr_flags &= ~FR_DUP; if (*fdp->fd_ifname) { fdp->fd_ifp = GETUNIT(fdp->fd_ifname); if (!fdp->fd_ifp) fdp->fd_ifp = (struct ifnet *)-1; else fp->fr_flags |= FR_DUP; } fdp = &fp->fr_tif; if (*fdp->fd_ifname) { fdp->fd_ifp = GETUNIT(fdp->fd_ifname); if (!fdp->fd_ifp) fdp->fd_ifp = (struct ifnet *)-1; } /* * Look for a matching filter rule, but don't include the next or * interface pointer in the comparison (fr_next, fr_ifa). */ for (; (f = *ftail); ftail = &f->fr_next) if (bcmp((char *)&f->fr_ip, (char *)&fp->fr_ip, FR_CMPSIZ) == 0) break; /* * If zero'ing statistics, copy current to caller and zero. */ if (req == SIOCZRLST) { if (!f) return ESRCH; IWCOPY((caddr_t)f, data, sizeof(*f)); f->fr_hits = 0; f->fr_bytes = 0; return 0; } if (!f) { if (req == SIOCINAFR || req == SIOCINIFR) { ftail = fprev; if (fp->fr_hits) { while (--fp->fr_hits && (f = *ftail)) ftail = &f->fr_next; } f = NULL; } } if (req == SIOCDELFR || req == SIOCRMIFR) { if (!f) error = ESRCH; else { if (f->fr_ref > 1) return EBUSY; if (fg && fg->fg_head) fg->fg_head->fr_ref--; if (unit == IPL_LOGAUTH) return fr_auth_ioctl(data, req, f, ftail); if (f->fr_grhead) fr_delgroup((u_int)f->fr_grhead, fp->fr_flags, unit, set); fixskip(fprev, f, -1); *ftail = f->fr_next; KFREE(f); } } else { if (f) error = EEXIST; else { if (unit == IPL_LOGAUTH) return fr_auth_ioctl(data, req, fp, ftail); KMALLOC(f, frentry_t *); if (f != NULL) { if (fg && fg->fg_head) fg->fg_head->fr_ref++; bcopy((char *)fp, (char *)f, sizeof(*f)); f->fr_ref = 1; f->fr_hits = 0; f->fr_next = *ftail; *ftail = f; if (req == SIOCINIFR || req == SIOCINAFR) fixskip(fprev, f, 1); f->fr_grp = NULL; if ((group = f->fr_grhead)) fg = fr_addgroup(group, f, unit, set); } else error = ENOMEM; } } return (error); } #ifdef _KERNEL /* * routines below for saving IP headers to buffer */ # ifdef __sgi # ifdef _KERNEL int IPL_EXTERN(open)(dev_t *pdev, int flags, int devtype, cred_t *cp) # else int IPL_EXTERN(open)(dev_t dev, int flags) # endif # else int IPL_EXTERN(open)(dev, flags # if ((_BSDI_VERSION >= 199510) || (BSD >= 199506) || (NetBSD >= 199511) || \ (__FreeBSD_version >= 220000) || defined(__OpenBSD__)) && defined(_KERNEL) , devtype, p) int devtype; struct proc *p; # else ) # endif dev_t dev; int flags; # endif /* __sgi */ { # if defined(__sgi) && defined(_KERNEL) u_int min = geteminor(*pdev); # else u_int min = GET_MINOR(dev); # endif if (IPL_LOGMAX < min) min = ENXIO; else min = 0; return min; } # ifdef __sgi int IPL_EXTERN(close)(dev_t dev, int flags, int devtype, cred_t *cp) #else int IPL_EXTERN(close)(dev, flags # if ((_BSDI_VERSION >= 199510) || (BSD >= 199506) || (NetBSD >= 199511) || \ (__FreeBSD_version >= 220000) || defined(__OpenBSD__)) && defined(_KERNEL) , devtype, p) int devtype; struct proc *p; # else ) # endif dev_t dev; int flags; # endif /* __sgi */ { 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. */ # ifdef __sgi int IPL_EXTERN(read)(dev_t dev, uio_t *uio, cred_t *crp) # else # if BSD >= 199306 int IPL_EXTERN(read)(dev, uio, ioflag) int ioflag; # else int IPL_EXTERN(read)(dev, uio) # endif dev_t dev; register struct uio *uio; # endif /* __sgi */ { # ifdef IPFILTER_LOG return ipflog_read(GET_MINOR(dev), uio); # else return ENXIO; # endif } /* * 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 send_reset(oip, fin) struct ip *oip; fr_info_t *fin; { struct tcphdr *tcp, *tcp2; struct mbuf *m; int tlen = 0; ip_t *ip; tcp = (struct tcphdr *)fin->fin_dp; if (tcp->th_flags & TH_RST) return -1; /* feedback loop */ # if (BSD < 199306) || defined(__sgi) m = m_get(M_DONTWAIT, MT_HEADER); # else m = m_gethdr(M_DONTWAIT, MT_HEADER); # endif if (m == NULL) return ENOBUFS; if (m == NULL) return -1; if (tcp->th_flags & TH_SYN) tlen = 1; m->m_len = sizeof(*tcp2) + sizeof(*ip); # if BSD >= 199306 m->m_data += max_linkhdr; m->m_pkthdr.len = sizeof(*tcp2) + sizeof(*ip); m->m_pkthdr.rcvif = (struct ifnet *)0; # endif ip = mtod(m, struct ip *); bzero((char *)ip, sizeof(*tcp2) + sizeof(*ip)); tcp2 = (struct tcphdr *)(ip + 1); ip->ip_src.s_addr = oip->ip_dst.s_addr; ip->ip_dst.s_addr = oip->ip_src.s_addr; tcp2->th_dport = tcp->th_sport; tcp2->th_sport = tcp->th_dport; tcp2->th_ack = ntohl(tcp->th_seq); tcp2->th_ack += tlen; tcp2->th_ack = htonl(tcp2->th_ack); tcp2->th_off = sizeof(*tcp2) >> 2; tcp2->th_flags = TH_RST|TH_ACK; ip->ip_p = IPPROTO_TCP; ip->ip_len = htons(sizeof(struct tcphdr)); tcp2->th_sum = in_cksum(m, sizeof(*ip) + sizeof(*tcp2)); ip->ip_id = oip->ip_id; ip->ip_tos = oip->ip_tos; ip->ip_len = sizeof(*ip) + sizeof(*tcp2); return send_ip(ip, fin, m); } static int send_ip(ip, fin, m) fr_info_t *fin; struct mbuf *m; ip_t *ip; { ip->ip_v = IPVERSION; ip->ip_hl = (sizeof(*ip) >> 2); # if (BSD < 199306) || defined(__sgi) ip->ip_ttl = tcp_ttl; # else ip->ip_ttl = ip_defttl; # endif # ifdef IPSEC m->m_pkthdr.rcvif = NULL; # endif return ipfr_fastroute(m, fin, NULL); } int send_icmp_err(oip, type, fin, dst) ip_t *oip; int type; fr_info_t *fin; struct in_addr dst; { struct icmp *icmp; struct mbuf *m; ip_t *nip; int code; if ((oip->ip_p == IPPROTO_ICMP) && !(fin->fin_fi.fi_fl & FI_SHORT)) switch (ntohs(fin->fin_data[0]) >> 8) { case ICMP_ECHO : case ICMP_TSTAMP : case ICMP_IREQ : case ICMP_MASKREQ : break; default : return 0; } code = fin->fin_icode; # if (BSD < 199306) || defined(__sgi) m = m_get(M_DONTWAIT, MT_HEADER); # else m = m_gethdr(M_DONTWAIT, MT_HEADER); # endif if (m == NULL) return ENOBUFS; m->m_len = sizeof(*nip) + sizeof(*icmp) + 8; # if BSD >= 199306 m->m_data += max_linkhdr; m->m_pkthdr.len = sizeof(*nip) + sizeof(*icmp) + 8; m->m_pkthdr.rcvif = (struct ifnet *)0; # endif bzero(mtod(m, char *), (size_t)sizeof(*nip) + sizeof(*icmp) + 8); nip = mtod(m, ip_t *); icmp = (struct icmp *)(nip + 1); nip->ip_p = IPPROTO_ICMP; nip->ip_id = oip->ip_id; nip->ip_sum = 0; nip->ip_ttl = 60; nip->ip_tos = oip->ip_tos; nip->ip_len = sizeof(*nip) + sizeof(*icmp) + 8; if (dst.s_addr == 0) { if (fr_ifpaddr(fin->fin_ifp, &dst) == -1) return -1; } nip->ip_src = dst; nip->ip_dst = oip->ip_src; icmp->icmp_type = type; icmp->icmp_code = code; icmp->icmp_cksum = 0; bcopy((char *)oip, (char *)&icmp->icmp_ip, sizeof(*oip)); bcopy((char *)oip + (oip->ip_hl << 2), (char *)&icmp->icmp_ip + sizeof(*oip), 8); /* 64 bits */ # ifndef sparc { register u_short __iplen, __ipoff; ip_t *ip = &icmp->icmp_ip; __iplen = ip->ip_len; __ipoff = ip->ip_off; ip->ip_len = htons(__iplen); ip->ip_off = htons(__ipoff); } # endif icmp->icmp_cksum = ipf_cksum((u_short *)icmp, sizeof(*icmp) + 8); return send_ip(nip, fin, m); } # if !defined(IPFILTER_LKM) && (__FreeBSD_version < 300000) && !defined(__sgi) # if (BSD < 199306) int iplinit __P((void)); int # else void iplinit __P((void)); void # endif iplinit() { if (iplattach() != 0) printf("IP Filter failed to attach\n"); ip_init(); } # endif /* ! __NetBSD__ */ size_t mbufchainlen(m0) register struct mbuf *m0; { register size_t len = 0; for (; m0; m0 = m0->m_next) len += m0->m_len; return len; } int ipfr_fastroute(m0, fin, fdp) struct mbuf *m0; fr_info_t *fin; frdest_t *fdp; { register struct ip *ip, *mhip; register struct mbuf *m = m0; register struct route *ro; int len, off, error = 0, hlen, code; struct ifnet *ifp, *sifp; struct sockaddr_in *dst; struct route iproute; frentry_t *fr; 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; fr = fin->fin_fr; if (fdp) ifp = fdp->fd_ifp; else { ifp = fin->fin_ifp; dst->sin_addr = ip->ip_dst; } /* * In case we're here due to "to " being used with "keep state", * check that we're going in the correct direction. */ if ((fr != NULL) && (fin->fin_rev != 0)) { if ((ifp != NULL) && (fdp == &fr->fr_tif)) return -1; dst->sin_addr = ip->ip_dst; } else if (fdp) dst->sin_addr = fdp->fd_ip.s_addr ? fdp->fd_ip : ip->ip_dst; # if BSD >= 199306 dst->sin_len = sizeof(*dst); # endif # if (BSD >= 199306) && !defined(__NetBSD__) && !defined(__bsdi__) && \ !defined(__OpenBSD__) # ifdef RTF_CLONING rtalloc_ign(ro, RTF_CLONING); # else rtalloc_ign(ro, RTF_PRCLONING); # endif # else rtalloc(ro); # endif if (!ifp) { if (!fr || !(fr->fr_flags & FR_FASTROUTE)) { error = -2; goto bad; } if (ro->ro_rt == 0 || (ifp = ro->ro_rt->rt_ifp) == 0) { 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. */ fin->fin_ifp = ifp; if (fin->fin_out == 0) { fin->fin_out = 1; if ((fin->fin_fr = ipacct[1][fr_active]) && (fr_scanlist(FR_NOMATCH, ip, fin, m) & FR_ACCOUNT)) { ATOMIC_INC(frstats[1].fr_acct); } fin->fin_fr = NULL; if (!fr || !(fr->fr_flags & FR_RETMASK)) { (void) fr_checkstate(ip, fin); (void) ip_natout(ip, fin); } } else ip->ip_sum = 0; /* * If small enough for interface, can just send directly. */ if (ip->ip_len <= ifp->if_mtu) { ip->ip_id = htons(ip->ip_id); 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); # if BSD >= 199306 error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst, ro->ro_rt); # else error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst); # endif goto done; } /* * Too large for interface; fragment if possible. * Must be able to put at least 8 bytes per fragment. */ if (ip->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) { error = ENOBUFS; goto bad; } # if BSD >= 199306 m->m_data += max_linkhdr; # else m->m_off = MMAXOFF - hlen; # endif 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); mhip->ip_hl = mhlen >> 2; } m->m_len = mhlen; mhip->ip_off = ((off - hlen) >> 3) + (ip->ip_off & ~IP_MF); if (ip->ip_off & IP_MF) mhip->ip_off |= IP_MF; 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)); m->m_next = m_copy(m0, off, len); if (m->m_next == 0) { error = ENOBUFS; /* ??? */ goto sendorfree; } # if BSD >= 199306 m->m_pkthdr.len = mhlen + len; m->m_pkthdr.rcvif = NULL; # endif mhip->ip_off = htons((u_short)mhip->ip_off); mhip->ip_sum = 0; mhip->ip_sum = in_cksum(m, mhlen); *mnext = m; 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->ip_off | 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) # if BSD >= 199306 error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst, ro->ro_rt); # else error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst); # endif else m_freem(m); } } done: if (!error) ipl_frouteok[0]++; else ipl_frouteok[1]++; if (ro->ro_rt) RTFREE(ro->ro_rt); return 0; bad: if (error == EMSGSIZE) { sifp = fin->fin_ifp; fin->fin_ifp = ifp; code = fin->fin_icode; fin->fin_icode = ICMP_UNREACH_NEEDFRAG; (void) send_icmp_err(ip, ICMP_UNREACH, fin, ip->ip_dst); fin->fin_ifp = sifp; fin->fin_icode = code; } m_freem(m); goto done; } #else /* #ifdef _KERNEL */ # ifdef __sgi static int no_output __P((struct ifnet *ifp, struct mbuf *m, struct sockaddr *s)) # else static int no_output __P((struct ifnet *ifp, struct mbuf *m, struct sockaddr *s, struct rtentry *rt)) # endif { return 0; } # ifdef __STDC__ # ifdef __sgi static int write_output __P((struct ifnet *ifp, struct mbuf *m, struct sockaddr *s)) # else static int write_output __P((struct ifnet *ifp, struct mbuf *m, struct sockaddr *s, struct rtentry *rt)) # endif { ip_t *ip = (ip_t *)m; # else static int write_output(ifp, ip) struct ifnet *ifp; ip_t *ip; { # endif char fname[32]; FILE *fp; # if (defined(NetBSD) && (NetBSD <= 1991011) && (NetBSD >= 199606)) || \ (defined(OpenBSD) && (OpenBSD >= 199603)) # if defined __OpenBSD__ sprintf(fname, "/var/run/%s", ifp->if_xname); # else sprintf(fname, "/tmp/%s", ifp->if_xname); # endif # else sprintf(fname, "/tmp/%s%d", ifp->if_name, ifp->if_unit); # endif /* * XXX * This is still raceable, if the attacker gains the ability to * erase the existing file in /tmp */ if ((fp = fopen(fname, "a"))) { fwrite((char *)ip, ntohs(ip->ip_len), 1, fp); fclose(fp); } return 0; } struct ifnet *get_unit(name) char *name; { struct ifnet *ifp, **ifa; # if (defined(NetBSD) && (NetBSD <= 1991011) && (NetBSD >= 199606)) || \ (defined(OpenBSD) && (OpenBSD >= 199603)) for (ifa = ifneta; ifa && (ifp = *ifa); ifa++) { if (!strcmp(name, ifp->if_xname)) return ifp; } # else char ifname[32], *s; for (ifa = ifneta; ifa && (ifp = *ifa); ifa++) { (void) sprintf(ifname, "%s%d", ifp->if_name, ifp->if_unit); if (!strcmp(name, ifname)) return ifp; } # endif if (!ifneta) { ifneta = (struct ifnet **)malloc(sizeof(ifp) * 2); if (!ifneta) return NULL; ifneta[1] = NULL; ifneta[0] = (struct ifnet *)calloc(1, sizeof(*ifp)); if (!ifneta[0]) { free(ifneta); return NULL; } nifs = 1; } else { nifs++; ifneta = (struct ifnet **)realloc(ifneta, (nifs + 1) * sizeof(*ifa)); if (!ifneta) { nifs = 0; return NULL; } ifneta[nifs] = NULL; ifneta[nifs - 1] = (struct ifnet *)malloc(sizeof(*ifp)); if (!ifneta[nifs - 1]) { nifs--; return NULL; } } ifp = ifneta[nifs - 1]; # if (defined(NetBSD) && (NetBSD <= 1991011) && (NetBSD >= 199606)) || \ (defined(OpenBSD) && (OpenBSD >= 199603)) strncpy(ifp->if_xname, name, sizeof(ifp->if_xname)); # else for (s = name; *s && !isdigit(*s); s++) ; if (*s && isdigit(*s)) { ifp->if_unit = atoi(s); ifp->if_name = (char *)malloc(s - name + 1); strncpy(ifp->if_name, name, s - name); ifp->if_name[s - name] = '\0'; } else { ifp->if_name = strdup(name); ifp->if_unit = -1; } # endif ifp->if_output = no_output; return ifp; } void init_ifp() { struct ifnet *ifp, **ifa; char fname[32]; int fd; # if (defined(NetBSD) && (NetBSD <= 1991011) && (NetBSD >= 199606)) || \ (defined(OpenBSD) && (OpenBSD >= 199603)) for (ifa = ifneta; ifa && (ifp = *ifa); ifa++) { ifp->if_output = write_output; # if defined(__OpenBSD__) sprintf(fname, "/var/run/%s", ifp->if_xname); # else sprintf(fname, "/tmp/%s", ifp->if_xname); # endif fd = open(fname, O_WRONLY|O_CREAT|O_EXCL|O_TRUNC, 0600); if (fd == -1) perror("open"); else close(fd); } # else for (ifa = ifneta; ifa && (ifp = *ifa); ifa++) { ifp->if_output = write_output; sprintf(fname, "/tmp/%s%d", ifp->if_name, ifp->if_unit); fd = open(fname, O_WRONLY|O_CREAT|O_EXCL|O_TRUNC, 0600); if (fd == -1) perror("open"); else close(fd); } # endif } int ipfr_fastroute(ip, fin, fdp) ip_t *ip; fr_info_t *fin; frdest_t *fdp; { struct ifnet *ifp = fdp->fd_ifp; if (!ifp) return 0; /* no routing table out here */ ip->ip_len = htons((u_short)ip->ip_len); ip->ip_off = htons((u_short)(ip->ip_off | IP_MF)); ip->ip_sum = 0; #ifdef __sgi (*ifp->if_output)(ifp, (void *)ip, NULL); #else (*ifp->if_output)(ifp, (void *)ip, NULL, 0); #endif return 0; } int ipllog __P((void)) { verbose("l"); return 0; } int send_reset(ip, ifp) ip_t *ip; struct ifnet *ifp; { verbose("- TCP RST sent\n"); return 0; } int icmp_error(ip, ifp) ip_t *ip; struct ifnet *ifp; { verbose("- TCP RST sent\n"); return 0; } void frsync() { return; } #endif /* _KERNEL */