/* * Copyright (C) 1995-2003 by Darren Reed. * * See the IPFILTER.LICENCE file for details on licencing. * * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #pragma ident "%Z%%M% %I% %E% SMI" #if defined(KERNEL) || defined(_KERNEL) # undef KERNEL # undef _KERNEL # define KERNEL 1 # define _KERNEL 1 #endif #include #include #include #include #include #if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \ defined(_KERNEL) # include "opt_ipfilter_log.h" #endif #if !defined(_KERNEL) # include # include # include # define _KERNEL # ifdef __OpenBSD__ struct file; # endif # include # undef _KERNEL #endif #if defined(_KERNEL) && (__FreeBSD_version >= 220000) # include # include #else # include #endif #if !defined(AIX) # include #endif #if !defined(linux) # include #endif #include #if defined(_KERNEL) # include # if !defined(__SVR4) && !defined(__svr4__) # include # endif #endif #if defined(__SVR4) || defined(__svr4__) # include # include # ifdef _KERNEL # include # endif # include # include #endif #if __FreeBSD_version >= 300000 # include #endif #include #if __FreeBSD_version >= 300000 # include # if defined(_KERNEL) && !defined(IPFILTER_LKM) # include "opt_ipfilter.h" # endif #endif #ifdef sun # include #endif #include #include #include #include #ifdef RFC1825 # include # include extern struct ifnet vpnif; #endif #if !defined(linux) # include #endif #include #include #include #include "netinet/ip_compat.h" #include #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" #ifdef IPFILTER_SYNC #include "netinet/ip_sync.h" #endif #if (__FreeBSD_version >= 300000) # include #endif /* END OF INCLUDES */ #undef SOCKADDR_IN #define SOCKADDR_IN struct sockaddr_in #if !defined(lint) static const char sccsid[] = "@(#)ip_nat.c 1.11 6/5/96 (C) 1995 Darren Reed"; static const char rcsid[] = "@(#)$Id: ip_nat.c,v 2.195.2.42 2005/08/11 19:51:36 darrenr Exp $"; #endif /* ======================================================================== */ /* How the NAT is organised and works. */ /* */ /* Inside (interface y) NAT Outside (interface x) */ /* -------------------- -+- ------------------------------------- */ /* Packet going | out, processsed by fr_checknatout() for x */ /* ------------> | ------------> */ /* src=10.1.1.1 | src=192.1.1.1 */ /* | */ /* | in, processed by fr_checknatin() for x */ /* <------------ | <------------ */ /* dst=10.1.1.1 | dst=192.1.1.1 */ /* -------------------- -+- ------------------------------------- */ /* fr_checknatout() - changes ip_src and if required, sport */ /* - creates a new mapping, if required. */ /* fr_checknatin() - changes ip_dst and if required, dport */ /* */ /* In the NAT table, internal source is recorded as "in" and externally */ /* seen as "out". */ /* ======================================================================== */ nat_t **nat_table[2] = { NULL, NULL }, *nat_instances = NULL; ipnat_t *nat_list = NULL; u_int ipf_nattable_max = NAT_TABLE_MAX; u_int ipf_nattable_sz = NAT_TABLE_SZ; u_int ipf_natrules_sz = NAT_SIZE; u_int ipf_rdrrules_sz = RDR_SIZE; u_int ipf_hostmap_sz = HOSTMAP_SIZE; u_int fr_nat_maxbucket = 0, fr_nat_maxbucket_reset = 1; u_32_t nat_masks = 0; u_32_t rdr_masks = 0; ipnat_t **nat_rules = NULL; ipnat_t **rdr_rules = NULL; hostmap_t **maptable = NULL; ipftq_t nat_tqb[IPF_TCP_NSTATES]; ipftq_t nat_udptq; ipftq_t nat_icmptq; ipftq_t nat_iptq; ipftq_t *nat_utqe = NULL; #ifdef IPFILTER_LOG int nat_logging = 1; #else int nat_logging = 0; #endif u_long fr_defnatage = DEF_NAT_AGE, fr_defnatipage = 120, /* 60 seconds */ fr_defnaticmpage = 6; /* 3 seconds */ natstat_t nat_stats; int fr_nat_lock = 0; int fr_nat_init = 0; #if SOLARIS extern int pfil_delayed_copy; #endif static int nat_flushtable __P((void)); static int nat_clearlist __P((void)); static void nat_addnat __P((struct ipnat *)); static void nat_addrdr __P((struct ipnat *)); static void nat_delete __P((struct nat *, int)); static void nat_delrdr __P((struct ipnat *)); static void nat_delnat __P((struct ipnat *)); static int fr_natgetent __P((caddr_t)); static int fr_natgetsz __P((caddr_t)); static int fr_natputent __P((caddr_t, int)); static void nat_tabmove __P((nat_t *)); static int nat_match __P((fr_info_t *, ipnat_t *)); static INLINE int nat_newmap __P((fr_info_t *, nat_t *, natinfo_t *)); static INLINE int nat_newrdr __P((fr_info_t *, nat_t *, natinfo_t *)); static hostmap_t *nat_hostmap __P((ipnat_t *, struct in_addr, struct in_addr, struct in_addr, u_32_t)); static void nat_hostmapdel __P((struct hostmap *)); static INLINE int nat_icmpquerytype4 __P((int)); static int nat_siocaddnat __P((ipnat_t *, ipnat_t **, int)); static void nat_siocdelnat __P((ipnat_t *, ipnat_t **, int)); static INLINE int nat_finalise __P((fr_info_t *, nat_t *, natinfo_t *, tcphdr_t *, nat_t **, int)); static void nat_resolverule __P((ipnat_t *)); static nat_t *fr_natclone __P((fr_info_t *, nat_t *)); static void nat_mssclamp __P((tcphdr_t *, u_32_t, fr_info_t *, u_short *)); static INLINE int nat_wildok __P((nat_t *, int, int, int, int)); /* ------------------------------------------------------------------------ */ /* Function: fr_natinit */ /* Returns: int - 0 == success, -1 == failure */ /* Parameters: Nil */ /* */ /* Initialise all of the NAT locks, tables and other structures. */ /* ------------------------------------------------------------------------ */ int fr_natinit() { int i; KMALLOCS(nat_table[0], nat_t **, sizeof(nat_t *) * ipf_nattable_sz); if (nat_table[0] != NULL) bzero((char *)nat_table[0], ipf_nattable_sz * sizeof(nat_t *)); else return -1; KMALLOCS(nat_table[1], nat_t **, sizeof(nat_t *) * ipf_nattable_sz); if (nat_table[1] != NULL) bzero((char *)nat_table[1], ipf_nattable_sz * sizeof(nat_t *)); else return -2; KMALLOCS(nat_rules, ipnat_t **, sizeof(ipnat_t *) * ipf_natrules_sz); if (nat_rules != NULL) bzero((char *)nat_rules, ipf_natrules_sz * sizeof(ipnat_t *)); else return -3; KMALLOCS(rdr_rules, ipnat_t **, sizeof(ipnat_t *) * ipf_rdrrules_sz); if (rdr_rules != NULL) bzero((char *)rdr_rules, ipf_rdrrules_sz * sizeof(ipnat_t *)); else return -4; KMALLOCS(maptable, hostmap_t **, sizeof(hostmap_t *) * ipf_hostmap_sz); if (maptable != NULL) bzero((char *)maptable, sizeof(hostmap_t *) * ipf_hostmap_sz); else return -5; KMALLOCS(nat_stats.ns_bucketlen[0], u_long *, ipf_nattable_sz * sizeof(u_long)); if (nat_stats.ns_bucketlen[0] == NULL) return -6; bzero((char *)nat_stats.ns_bucketlen[0], ipf_nattable_sz * sizeof(u_long)); KMALLOCS(nat_stats.ns_bucketlen[1], u_long *, ipf_nattable_sz * sizeof(u_long)); if (nat_stats.ns_bucketlen[1] == NULL) return -7; bzero((char *)nat_stats.ns_bucketlen[1], ipf_nattable_sz * sizeof(u_long)); if (fr_nat_maxbucket == 0) { for (i = ipf_nattable_sz; i > 0; i >>= 1) fr_nat_maxbucket++; fr_nat_maxbucket *= 2; } fr_sttab_init(nat_tqb); /* * Increase this because we may have "keep state" following this too * and packet storms can occur if this is removed too quickly. */ nat_tqb[IPF_TCPS_CLOSED].ifq_ttl = fr_tcplastack; nat_tqb[IPF_TCP_NSTATES - 1].ifq_next = &nat_udptq; nat_udptq.ifq_ttl = fr_defnatage; nat_udptq.ifq_ref = 1; nat_udptq.ifq_head = NULL; nat_udptq.ifq_tail = &nat_udptq.ifq_head; MUTEX_INIT(&nat_udptq.ifq_lock, "nat ipftq udp tab"); nat_udptq.ifq_next = &nat_icmptq; nat_icmptq.ifq_ttl = fr_defnaticmpage; nat_icmptq.ifq_ref = 1; nat_icmptq.ifq_head = NULL; nat_icmptq.ifq_tail = &nat_icmptq.ifq_head; MUTEX_INIT(&nat_icmptq.ifq_lock, "nat icmp ipftq tab"); nat_icmptq.ifq_next = &nat_iptq; nat_iptq.ifq_ttl = fr_defnatipage; nat_iptq.ifq_ref = 1; nat_iptq.ifq_head = NULL; nat_iptq.ifq_tail = &nat_iptq.ifq_head; MUTEX_INIT(&nat_iptq.ifq_lock, "nat ip ipftq tab"); nat_iptq.ifq_next = NULL; for (i = 0; i < IPF_TCP_NSTATES; i++) { if (nat_tqb[i].ifq_ttl < fr_defnaticmpage) nat_tqb[i].ifq_ttl = fr_defnaticmpage; #ifdef LARGE_NAT else if (nat_tqb[i].ifq_ttl > fr_defnatage) nat_tqb[i].ifq_ttl = fr_defnatage; #endif } /* * Increase this because we may have "keep state" following * this too and packet storms can occur if this is removed * too quickly. */ nat_tqb[IPF_TCPS_CLOSED].ifq_ttl = nat_tqb[IPF_TCPS_LAST_ACK].ifq_ttl; RWLOCK_INIT(&ipf_nat, "ipf IP NAT rwlock"); RWLOCK_INIT(&ipf_natfrag, "ipf IP NAT-Frag rwlock"); MUTEX_INIT(&ipf_nat_new, "ipf nat new mutex"); MUTEX_INIT(&ipf_natio, "ipf nat io mutex"); fr_nat_init = 1; return 0; } /* ------------------------------------------------------------------------ */ /* Function: nat_addrdr */ /* Returns: Nil */ /* Parameters: n(I) - pointer to NAT rule to add */ /* */ /* Adds a redirect rule to the hash table of redirect rules and the list of */ /* loaded NAT rules. Updates the bitmask indicating which netmasks are in */ /* use by redirect rules. */ /* ------------------------------------------------------------------------ */ static void nat_addrdr(n) ipnat_t *n; { ipnat_t **np; u_32_t j; u_int hv; int k; k = count4bits(n->in_outmsk); if ((k >= 0) && (k != 32)) rdr_masks |= 1 << k; j = (n->in_outip & n->in_outmsk); hv = NAT_HASH_FN(j, 0, ipf_rdrrules_sz); np = rdr_rules + hv; while (*np != NULL) np = &(*np)->in_rnext; n->in_rnext = NULL; n->in_prnext = np; n->in_hv = hv; *np = n; } /* ------------------------------------------------------------------------ */ /* Function: nat_addnat */ /* Returns: Nil */ /* Parameters: n(I) - pointer to NAT rule to add */ /* */ /* Adds a NAT map rule to the hash table of rules and the list of loaded */ /* NAT rules. Updates the bitmask indicating which netmasks are in use by */ /* redirect rules. */ /* ------------------------------------------------------------------------ */ static void nat_addnat(n) ipnat_t *n; { ipnat_t **np; u_32_t j; u_int hv; int k; k = count4bits(n->in_inmsk); if ((k >= 0) && (k != 32)) nat_masks |= 1 << k; j = (n->in_inip & n->in_inmsk); hv = NAT_HASH_FN(j, 0, ipf_natrules_sz); np = nat_rules + hv; while (*np != NULL) np = &(*np)->in_mnext; n->in_mnext = NULL; n->in_pmnext = np; n->in_hv = hv; *np = n; } /* ------------------------------------------------------------------------ */ /* Function: nat_delrdr */ /* Returns: Nil */ /* Parameters: n(I) - pointer to NAT rule to delete */ /* */ /* Removes a redirect rule from the hash table of redirect rules. */ /* ------------------------------------------------------------------------ */ static void nat_delrdr(n) ipnat_t *n; { if (n->in_rnext) n->in_rnext->in_prnext = n->in_prnext; *n->in_prnext = n->in_rnext; } /* ------------------------------------------------------------------------ */ /* Function: nat_delnat */ /* Returns: Nil */ /* Parameters: n(I) - pointer to NAT rule to delete */ /* */ /* Removes a NAT map rule from the hash table of NAT map rules. */ /* ------------------------------------------------------------------------ */ static void nat_delnat(n) ipnat_t *n; { if (n->in_mnext != NULL) n->in_mnext->in_pmnext = n->in_pmnext; *n->in_pmnext = n->in_mnext; } /* ------------------------------------------------------------------------ */ /* Function: nat_hostmap */ /* Returns: struct hostmap* - NULL if no hostmap could be created, */ /* else a pointer to the hostmapping to use */ /* Parameters: np(I) - pointer to NAT rule */ /* real(I) - real IP address */ /* map(I) - mapped IP address */ /* port(I) - destination port number */ /* Write Locks: ipf_nat */ /* */ /* Check if an ip address has already been allocated for a given mapping */ /* that is not doing port based translation. If is not yet allocated, then */ /* create a new entry if a non-NULL NAT rule pointer has been supplied. */ /* ------------------------------------------------------------------------ */ static struct hostmap *nat_hostmap(np, src, dst, map, port) ipnat_t *np; struct in_addr src; struct in_addr dst; struct in_addr map; u_32_t port; { hostmap_t *hm; u_int hv; hv = (src.s_addr ^ dst.s_addr); hv += src.s_addr; hv += dst.s_addr; hv %= HOSTMAP_SIZE; for (hm = maptable[hv]; hm; hm = hm->hm_next) if ((hm->hm_srcip.s_addr == src.s_addr) && (hm->hm_dstip.s_addr == dst.s_addr) && ((np == NULL) || (np == hm->hm_ipnat)) && ((port == 0) || (port == hm->hm_port))) { hm->hm_ref++; return hm; } if (np == NULL) return NULL; KMALLOC(hm, hostmap_t *); if (hm) { hm->hm_next = maptable[hv]; hm->hm_pnext = maptable + hv; if (maptable[hv] != NULL) maptable[hv]->hm_pnext = &hm->hm_next; maptable[hv] = hm; hm->hm_ipnat = np; hm->hm_srcip = src; hm->hm_dstip = dst; hm->hm_mapip = map; hm->hm_ref = 1; hm->hm_port = port; } return hm; } /* ------------------------------------------------------------------------ */ /* Function: nat_hostmapdel */ /* Returns: Nil */ /* Parameters: hm(I) - pointer to hostmap structure */ /* Write Locks: ipf_nat */ /* */ /* Decrement the references to this hostmap structure by one. If this */ /* reaches zero then remove it and free it. */ /* ------------------------------------------------------------------------ */ static void nat_hostmapdel(hm) struct hostmap *hm; { hm->hm_ref--; if (hm->hm_ref == 0) { if (hm->hm_next) hm->hm_next->hm_pnext = hm->hm_pnext; *hm->hm_pnext = hm->hm_next; KFREE(hm); } } /* ------------------------------------------------------------------------ */ /* Function: fix_outcksum */ /* Returns: Nil */ /* Parameters: fin(I) - pointer to packet information */ /* sp(I) - location of 16bit checksum to update */ /* n((I) - amount to adjust checksum by */ /* */ /* Adjusts the 16bit checksum by "n" for packets going out. */ /* ------------------------------------------------------------------------ */ void fix_outcksum(fin, sp, n) fr_info_t *fin; u_short *sp; u_32_t n; { u_short sumshort; u_32_t sum1; if (n == 0) return; if (n & NAT_HW_CKSUM) { n &= 0xffff; n += fin->fin_dlen; n = (n & 0xffff) + (n >> 16); *sp = n & 0xffff; return; } sum1 = (~ntohs(*sp)) & 0xffff; sum1 += (n); sum1 = (sum1 >> 16) + (sum1 & 0xffff); /* Again */ sum1 = (sum1 >> 16) + (sum1 & 0xffff); sumshort = ~(u_short)sum1; *(sp) = htons(sumshort); } /* ------------------------------------------------------------------------ */ /* Function: fix_incksum */ /* Returns: Nil */ /* Parameters: fin(I) - pointer to packet information */ /* sp(I) - location of 16bit checksum to update */ /* n((I) - amount to adjust checksum by */ /* */ /* Adjusts the 16bit checksum by "n" for packets going in. */ /* ------------------------------------------------------------------------ */ void fix_incksum(fin, sp, n) fr_info_t *fin; u_short *sp; u_32_t n; { u_short sumshort; u_32_t sum1; if (n == 0) return; if (n & NAT_HW_CKSUM) { n &= 0xffff; n += fin->fin_dlen; n = (n & 0xffff) + (n >> 16); *sp = n & 0xffff; return; } sum1 = (~ntohs(*sp)) & 0xffff; sum1 += ~(n) & 0xffff; sum1 = (sum1 >> 16) + (sum1 & 0xffff); /* Again */ sum1 = (sum1 >> 16) + (sum1 & 0xffff); sumshort = ~(u_short)sum1; *(sp) = htons(sumshort); } /* ------------------------------------------------------------------------ */ /* Function: fix_datacksum */ /* Returns: Nil */ /* Parameters: sp(I) - location of 16bit checksum to update */ /* n((I) - amount to adjust checksum by */ /* */ /* Fix_datacksum is used *only* for the adjustments of checksums in the */ /* data section of an IP packet. */ /* */ /* The only situation in which you need to do this is when NAT'ing an */ /* ICMP error message. Such a message, contains in its body the IP header */ /* of the original IP packet, that causes the error. */ /* */ /* You can't use fix_incksum or fix_outcksum in that case, because for the */ /* kernel the data section of the ICMP error is just data, and no special */ /* processing like hardware cksum or ntohs processing have been done by the */ /* kernel on the data section. */ /* ------------------------------------------------------------------------ */ void fix_datacksum(sp, n) u_short *sp; u_32_t n; { u_short sumshort; u_32_t sum1; if (n == 0) return; sum1 = (~ntohs(*sp)) & 0xffff; sum1 += (n); sum1 = (sum1 >> 16) + (sum1 & 0xffff); /* Again */ sum1 = (sum1 >> 16) + (sum1 & 0xffff); sumshort = ~(u_short)sum1; *(sp) = htons(sumshort); } /* ------------------------------------------------------------------------ */ /* Function: fr_nat_ioctl */ /* Returns: int - 0 == success, != 0 == failure */ /* Parameters: data(I) - pointer to ioctl data */ /* cmd(I) - ioctl command integer */ /* mode(I) - file mode bits used with open */ /* */ /* Processes an ioctl call made to operate on the IP Filter NAT device. */ /* ------------------------------------------------------------------------ */ int fr_nat_ioctl(data, cmd, mode) ioctlcmd_t cmd; caddr_t data; int mode; { ipnat_t *nat, *nt, *n = NULL, **np = NULL; int error = 0, ret, arg, getlock; ipnat_t natd; #if (BSD >= 199306) && defined(_KERNEL) if ((securelevel >= 2) && (mode & FWRITE)) return EPERM; #endif #if defined(__osf__) && defined(_KERNEL) getlock = 0; #else getlock = (mode & NAT_LOCKHELD) ? 0 : 1; #endif nat = NULL; /* XXX gcc -Wuninitialized */ if (cmd == (ioctlcmd_t)SIOCADNAT) { KMALLOC(nt, ipnat_t *); } else { nt = NULL; } if ((cmd == (ioctlcmd_t)SIOCADNAT) || (cmd == (ioctlcmd_t)SIOCRMNAT)) { if (mode & NAT_SYSSPACE) { bcopy(data, (char *)&natd, sizeof(natd)); error = 0; } else { error = fr_inobj(data, &natd, IPFOBJ_IPNAT); } } else if (cmd == (ioctlcmd_t)SIOCIPFFL) { /* SIOCFLNAT & SIOCCNATL */ BCOPYIN(data, &arg, sizeof(arg)); } if (error != 0) goto done; /* * For add/delete, look to see if the NAT entry is already present */ if ((cmd == (ioctlcmd_t)SIOCADNAT) || (cmd == (ioctlcmd_t)SIOCRMNAT)) { nat = &natd; if (nat->in_v == 0) /* For backward compat. */ nat->in_v = 4; nat->in_flags &= IPN_USERFLAGS; if ((nat->in_redir & NAT_MAPBLK) == 0) { if ((nat->in_flags & IPN_SPLIT) == 0) nat->in_inip &= nat->in_inmsk; if ((nat->in_flags & IPN_IPRANGE) == 0) nat->in_outip &= nat->in_outmsk; } MUTEX_ENTER(&ipf_natio); for (np = &nat_list; ((n = *np) != NULL); np = &n->in_next) if (!bcmp((char *)&nat->in_flags, (char *)&n->in_flags, IPN_CMPSIZ)) break; } switch (cmd) { #ifdef IPFILTER_LOG case SIOCIPFFB : { int tmp; if (!(mode & FWRITE)) error = EPERM; else { tmp = ipflog_clear(IPL_LOGNAT); BCOPYOUT((char *)&tmp, (char *)data, sizeof(tmp)); } break; } case SIOCSETLG : if (!(mode & FWRITE)) error = EPERM; else { BCOPYIN((char *)data, (char *)&nat_logging, sizeof(nat_logging)); } break; case SIOCGETLG : BCOPYOUT((char *)&nat_logging, (char *)data, sizeof(nat_logging)); break; case FIONREAD : arg = iplused[IPL_LOGNAT]; BCOPYOUT(&arg, data, sizeof(arg)); break; #endif case SIOCADNAT : if (!(mode & FWRITE)) { error = EPERM; } else if (n != NULL) { error = EEXIST; } else if (nt == NULL) { error = ENOMEM; } if (error != 0) { MUTEX_EXIT(&ipf_natio); break; } bcopy((char *)nat, (char *)nt, sizeof(*n)); error = nat_siocaddnat(nt, np, getlock); MUTEX_EXIT(&ipf_natio); if (error == 0) nt = NULL; break; case SIOCRMNAT : if (!(mode & FWRITE)) { error = EPERM; n = NULL; } else if (n == NULL) { error = ESRCH; } if (error != 0) { MUTEX_EXIT(&ipf_natio); break; } nat_siocdelnat(n, np, getlock); MUTEX_EXIT(&ipf_natio); n = NULL; break; case SIOCGNATS : nat_stats.ns_table[0] = nat_table[0]; nat_stats.ns_table[1] = nat_table[1]; nat_stats.ns_list = nat_list; nat_stats.ns_maptable = maptable; nat_stats.ns_nattab_sz = ipf_nattable_sz; nat_stats.ns_nattab_max = ipf_nattable_max; nat_stats.ns_rultab_sz = ipf_natrules_sz; nat_stats.ns_rdrtab_sz = ipf_rdrrules_sz; nat_stats.ns_hostmap_sz = ipf_hostmap_sz; nat_stats.ns_instances = nat_instances; nat_stats.ns_apslist = ap_sess_list; error = fr_outobj(data, &nat_stats, IPFOBJ_NATSTAT); break; case SIOCGNATL : { natlookup_t nl; if (getlock) { READ_ENTER(&ipf_nat); } error = fr_inobj(data, &nl, IPFOBJ_NATLOOKUP); if (error == 0) { if (nat_lookupredir(&nl) != NULL) { error = fr_outobj(data, &nl, IPFOBJ_NATLOOKUP); } else { error = ESRCH; } } if (getlock) { RWLOCK_EXIT(&ipf_nat); } break; } case SIOCIPFFL : /* old SIOCFLNAT & SIOCCNATL */ if (!(mode & FWRITE)) { error = EPERM; break; } if (getlock) { WRITE_ENTER(&ipf_nat); } error = 0; if (arg == 0) ret = nat_flushtable(); else if (arg == 1) ret = nat_clearlist(); else error = EINVAL; if (getlock) { RWLOCK_EXIT(&ipf_nat); } if (error == 0) { BCOPYOUT(&ret, data, sizeof(ret)); } break; case SIOCPROXY : error = appr_ioctl(data, cmd, mode); break; case SIOCSTLCK : if (!(mode & FWRITE)) { error = EPERM; } else { fr_lock(data, &fr_nat_lock); } break; case SIOCSTPUT : if (fr_nat_lock && (mode & FWRITE)) { error = fr_natputent(data, getlock); } else { error = EACCES; } break; case SIOCSTGSZ : if (fr_nat_lock) { if (getlock) { READ_ENTER(&ipf_nat); } error = fr_natgetsz(data); if (getlock) { RWLOCK_EXIT(&ipf_nat); } } else error = EACCES; break; case SIOCSTGET : if (fr_nat_lock) { if (getlock) { READ_ENTER(&ipf_nat); } error = fr_natgetent(data); if (getlock) { RWLOCK_EXIT(&ipf_nat); } } else error = EACCES; break; default : error = EINVAL; break; } done: if (nt) KFREE(nt); return error; } /* ------------------------------------------------------------------------ */ /* Function: nat_siocaddnat */ /* Returns: int - 0 == success, != 0 == failure */ /* Parameters: n(I) - pointer to new NAT rule */ /* np(I) - pointer to where to insert new NAT rule */ /* getlock(I) - flag indicating if lock on ipf_nat is held */ /* Mutex Locks: ipf_natio */ /* */ /* Handle SIOCADNAT. Resolve and calculate details inside the NAT rule */ /* from information passed to the kernel, then add it to the appropriate */ /* NAT rule table(s). */ /* ------------------------------------------------------------------------ */ static int nat_siocaddnat(n, np, getlock) ipnat_t *n, **np; int getlock; { int error = 0, i, j; nat_resolverule(n); if (n->in_plabel[0] != '\0') { if (n->in_apr == NULL) return ENOENT; } if ((n->in_age[0] == 0) && (n->in_age[1] != 0)) return EINVAL; n->in_use = 0; if (n->in_redir & NAT_MAPBLK) n->in_space = USABLE_PORTS * ~ntohl(n->in_outmsk); else if (n->in_flags & IPN_AUTOPORTMAP) n->in_space = USABLE_PORTS * ~ntohl(n->in_inmsk); else if (n->in_flags & IPN_IPRANGE) n->in_space = ntohl(n->in_outmsk) - ntohl(n->in_outip); else if (n->in_flags & IPN_SPLIT) n->in_space = 2; else if (n->in_outmsk != 0) n->in_space = ~ntohl(n->in_outmsk); else n->in_space = 1; /* * Calculate the number of valid IP addresses in the output * mapping range. In all cases, the range is inclusive of * the start and ending IP addresses. * If to a CIDR address, lose 2: broadcast + network address * (so subtract 1) * If to a range, add one. * If to a single IP address, set to 1. */ if (n->in_space) { if ((n->in_flags & IPN_IPRANGE) != 0) n->in_space += 1; else n->in_space -= 1; } else n->in_space = 1; if ((n->in_outmsk != 0xffffffff) && (n->in_outmsk != 0) && ((n->in_flags & (IPN_IPRANGE|IPN_SPLIT)) == 0)) n->in_nip = ntohl(n->in_outip) + 1; else if ((n->in_flags & IPN_SPLIT) && (n->in_redir & NAT_REDIRECT)) n->in_nip = ntohl(n->in_inip); else n->in_nip = ntohl(n->in_outip); if (n->in_redir & NAT_MAP) { n->in_pnext = ntohs(n->in_pmin); /* * Multiply by the number of ports made available. */ if (ntohs(n->in_pmax) >= ntohs(n->in_pmin)) { n->in_space *= (ntohs(n->in_pmax) - ntohs(n->in_pmin) + 1); /* * Because two different sources can map to * different destinations but use the same * local IP#/port #. * If the result is smaller than in_space, then * we may have wrapped around 32bits. */ i = n->in_inmsk; if ((i != 0) && (i != 0xffffffff)) { j = n->in_space * (~ntohl(i) + 1); if (j >= n->in_space) n->in_space = j; else n->in_space = 0xffffffff; } } /* * If no protocol is specified, multiple by 256 to allow for * at least one IP:IP mapping per protocol. */ if ((n->in_flags & IPN_TCPUDPICMP) == 0) { j = n->in_space * 256; if (j >= n->in_space) n->in_space = j; else n->in_space = 0xffffffff; } } /* Otherwise, these fields are preset */ if (getlock) { WRITE_ENTER(&ipf_nat); } n->in_next = NULL; *np = n; if (n->in_age[0] != 0) n->in_tqehead[0] = fr_addtimeoutqueue(&nat_utqe, n->in_age[0]); if (n->in_age[1] != 0) n->in_tqehead[1] = fr_addtimeoutqueue(&nat_utqe, n->in_age[1]); if (n->in_redir & NAT_REDIRECT) { n->in_flags &= ~IPN_NOTDST; nat_addrdr(n); } if (n->in_redir & (NAT_MAP|NAT_MAPBLK)) { n->in_flags &= ~IPN_NOTSRC; nat_addnat(n); } n = NULL; nat_stats.ns_rules++; #if SOLARIS pfil_delayed_copy = 0; #endif if (getlock) { RWLOCK_EXIT(&ipf_nat); /* WRITE */ } return error; } /* ------------------------------------------------------------------------ */ /* Function: nat_resolvrule */ /* Returns: Nil */ /* Parameters: n(I) - pointer to NAT rule */ /* */ /* Handle SIOCADNAT. Resolve and calculate details inside the NAT rule */ /* from information passed to the kernel, then add it to the appropriate */ /* NAT rule table(s). */ /* ------------------------------------------------------------------------ */ static void nat_resolverule(n) ipnat_t *n; { n->in_ifnames[0][LIFNAMSIZ - 1] = '\0'; n->in_ifps[0] = fr_resolvenic(n->in_ifnames[0], 4); n->in_ifnames[1][LIFNAMSIZ - 1] = '\0'; if (n->in_ifnames[1][0] == '\0') { (void) strncpy(n->in_ifnames[1], n->in_ifnames[0], LIFNAMSIZ); n->in_ifps[1] = n->in_ifps[0]; } else { n->in_ifps[1] = fr_resolvenic(n->in_ifnames[0], 4); } if (n->in_plabel[0] != '\0') { n->in_apr = appr_lookup(n->in_p, n->in_plabel); } } /* ------------------------------------------------------------------------ */ /* Function: nat_siocdelnat */ /* Returns: int - 0 == success, != 0 == failure */ /* Parameters: n(I) - pointer to new NAT rule */ /* np(I) - pointer to where to insert new NAT rule */ /* getlock(I) - flag indicating if lock on ipf_nat is held */ /* Mutex Locks: ipf_natio */ /* */ /* Handle SIOCADNAT. Resolve and calculate details inside the NAT rule */ /* from information passed to the kernel, then add it to the appropriate */ /* NAT rule table(s). */ /* ------------------------------------------------------------------------ */ static void nat_siocdelnat(n, np, getlock) ipnat_t *n, **np; int getlock; { if (getlock) { WRITE_ENTER(&ipf_nat); } if (n->in_redir & NAT_REDIRECT) nat_delrdr(n); if (n->in_redir & (NAT_MAPBLK|NAT_MAP)) nat_delnat(n); if (nat_list == NULL) { nat_masks = 0; rdr_masks = 0; } if (n->in_tqehead[0] != NULL) { if (fr_deletetimeoutqueue(n->in_tqehead[0]) == 0) { fr_freetimeoutqueue(n->in_tqehead[1]); } } if (n->in_tqehead[1] != NULL) { if (fr_deletetimeoutqueue(n->in_tqehead[1]) == 0) { fr_freetimeoutqueue(n->in_tqehead[1]); } } *np = n->in_next; if (n->in_use == 0) { if (n->in_apr) appr_free(n->in_apr); KFREE(n); nat_stats.ns_rules--; #if SOLARIS if (nat_stats.ns_rules == 0) pfil_delayed_copy = 1; #endif } else { n->in_flags |= IPN_DELETE; n->in_next = NULL; } if (getlock) { RWLOCK_EXIT(&ipf_nat); /* READ/WRITE */ } } /* ------------------------------------------------------------------------ */ /* Function: fr_natgetsz */ /* Returns: int - 0 == success, != 0 is the error value. */ /* Parameters: data(I) - pointer to natget structure with kernel pointer */ /* get the size of. */ /* */ /* Handle SIOCSTGSZ. */ /* Return the size of the nat list entry to be copied back to user space. */ /* The size of the entry is stored in the ng_sz field and the enture natget */ /* structure is copied back to the user. */ /* ------------------------------------------------------------------------ */ static int fr_natgetsz(data) caddr_t data; { ap_session_t *aps; nat_t *nat, *n; natget_t ng; BCOPYIN(data, &ng, sizeof(ng)); nat = ng.ng_ptr; if (!nat) { nat = nat_instances; ng.ng_sz = 0; /* * Empty list so the size returned is 0. Simple. */ if (nat == NULL) { BCOPYOUT(&ng, data, sizeof(ng)); return 0; } } else { /* * Make sure the pointer we're copying from exists in the * current list of entries. Security precaution to prevent * copying of random kernel data. */ for (n = nat_instances; n; n = n->nat_next) if (n == nat) break; if (!n) return ESRCH; } /* * Incluse any space required for proxy data structures. */ ng.ng_sz = sizeof(nat_save_t); aps = nat->nat_aps; if (aps != NULL) { ng.ng_sz += sizeof(ap_session_t) - 4; if (aps->aps_data != 0) ng.ng_sz += aps->aps_psiz; } BCOPYOUT(&ng, data, sizeof(ng)); return 0; } /* ------------------------------------------------------------------------ */ /* Function: fr_natgetent */ /* Returns: int - 0 == success, != 0 is the error value. */ /* Parameters: data(I) - pointer to natget structure with kernel pointer */ /* to NAT structure to copy out. */ /* */ /* Handle SIOCSTGET. */ /* Copies out NAT entry to user space. Any additional data held for a */ /* proxy is also copied, as to is the NAT rule which was responsible for it */ /* ------------------------------------------------------------------------ */ static int fr_natgetent(data) caddr_t data; { int error, outsize; ap_session_t *aps; nat_save_t *ipn, ipns; nat_t *n, *nat; error = fr_inobj(data, &ipns, IPFOBJ_NATSAVE); if (error != 0) return error; if ((ipns.ipn_dsize < sizeof(ipns)) || (ipns.ipn_dsize > 81920)) return EINVAL; KMALLOCS(ipn, nat_save_t *, ipns.ipn_dsize); if (ipn == NULL) return ENOMEM; ipn->ipn_dsize = ipns.ipn_dsize; nat = ipns.ipn_next; if (nat == NULL) { nat = nat_instances; if (nat == NULL) { if (nat_instances == NULL) error = ENOENT; goto finished; } } else { /* * Make sure the pointer we're copying from exists in the * current list of entries. Security precaution to prevent * copying of random kernel data. */ for (n = nat_instances; n; n = n->nat_next) if (n == nat) break; if (n == NULL) { error = ESRCH; goto finished; } } ipn->ipn_next = nat->nat_next; /* * Copy the NAT structure. */ bcopy((char *)nat, &ipn->ipn_nat, sizeof(*nat)); /* * If we have a pointer to the NAT rule it belongs to, save that too. */ if (nat->nat_ptr != NULL) bcopy((char *)nat->nat_ptr, (char *)&ipn->ipn_ipnat, sizeof(ipn->ipn_ipnat)); /* * If we also know the NAT entry has an associated filter rule, * save that too. */ if (nat->nat_fr != NULL) bcopy((char *)nat->nat_fr, (char *)&ipn->ipn_fr, sizeof(ipn->ipn_fr)); /* * Last but not least, if there is an application proxy session set * up for this NAT entry, then copy that out too, including any * private data saved along side it by the proxy. */ aps = nat->nat_aps; outsize = ipn->ipn_dsize - sizeof(*ipn) + sizeof(ipn->ipn_data); if (aps != NULL) { char *s; if (outsize < sizeof(*aps)) { error = ENOBUFS; goto finished; } s = ipn->ipn_data; bcopy((char *)aps, s, sizeof(*aps)); s += sizeof(*aps); outsize -= sizeof(*aps); if ((aps->aps_data != NULL) && (outsize >= aps->aps_psiz)) bcopy(aps->aps_data, s, aps->aps_psiz); else error = ENOBUFS; } if (error == 0) { error = fr_outobjsz(data, ipn, IPFOBJ_NATSAVE, ipns.ipn_dsize); } finished: if (ipn != NULL) { KFREES(ipn, ipns.ipn_dsize); } return error; } /* ------------------------------------------------------------------------ */ /* Function: fr_natputent */ /* Returns: int - 0 == success, != 0 is the error value. */ /* Parameters: data(I) - pointer to natget structure with NAT */ /* structure information to load into the kernel */ /* getlock(I) - flag indicating whether or not a write lock */ /* on ipf_nat is already held. */ /* */ /* Handle SIOCSTPUT. */ /* Loads a NAT table entry from user space, including a NAT rule, proxy and */ /* firewall rule data structures, if pointers to them indicate so. */ /* ------------------------------------------------------------------------ */ static int fr_natputent(data, getlock) caddr_t data; int getlock; { nat_save_t ipn, *ipnn; ap_session_t *aps; nat_t *n, *nat; frentry_t *fr; fr_info_t fin; ipnat_t *in; int error; error = fr_inobj(data, &ipn, IPFOBJ_NATSAVE); if (error != 0) return error; /* * Initialise early because of code at junkput label. */ in = NULL; aps = NULL; nat = NULL; ipnn = NULL; /* * New entry, copy in the rest of the NAT entry if it's size is more * than just the nat_t structure. */ fr = NULL; if (ipn.ipn_dsize > sizeof(ipn)) { if (ipn.ipn_dsize > 81920) { error = ENOMEM; goto junkput; } KMALLOCS(ipnn, nat_save_t *, ipn.ipn_dsize); if (ipnn == NULL) return ENOMEM; error = fr_inobjsz(data, ipnn, IPFOBJ_NATSAVE, ipn.ipn_dsize); if (error != 0) { error = EFAULT; goto junkput; } } else ipnn = &ipn; KMALLOC(nat, nat_t *); if (nat == NULL) { error = ENOMEM; goto junkput; } bcopy((char *)&ipnn->ipn_nat, (char *)nat, sizeof(*nat)); /* * Initialize all these so that nat_delete() doesn't cause a crash. */ bzero((char *)nat, offsetof(struct nat, nat_tqe)); nat->nat_tqe.tqe_pnext = NULL; nat->nat_tqe.tqe_next = NULL; nat->nat_tqe.tqe_ifq = NULL; nat->nat_tqe.tqe_parent = nat; /* * Restore the rule associated with this nat session */ in = ipnn->ipn_nat.nat_ptr; if (in != NULL) { KMALLOC(in, ipnat_t *); nat->nat_ptr = in; if (in == NULL) { error = ENOMEM; goto junkput; } bzero((char *)in, offsetof(struct ipnat, in_next6)); bcopy((char *)&ipnn->ipn_ipnat, (char *)in, sizeof(*in)); in->in_use = 1; in->in_flags |= IPN_DELETE; ATOMIC_INC(nat_stats.ns_rules); nat_resolverule(in); } /* * Check that the NAT entry doesn't already exist in the kernel. */ bzero((char *)&fin, sizeof(fin)); fin.fin_p = nat->nat_p; if (nat->nat_dir == NAT_OUTBOUND) { fin.fin_data[0] = ntohs(nat->nat_oport); fin.fin_data[1] = ntohs(nat->nat_outport); fin.fin_ifp = nat->nat_ifps[0]; if (getlock) { READ_ENTER(&ipf_nat); } n = nat_inlookup(&fin, nat->nat_flags, fin.fin_p, nat->nat_oip, nat->nat_outip); if (getlock) { RWLOCK_EXIT(&ipf_nat); } if (n != NULL) { error = EEXIST; goto junkput; } } else if (nat->nat_dir == NAT_INBOUND) { fin.fin_data[0] = ntohs(nat->nat_inport); fin.fin_data[1] = ntohs(nat->nat_oport); fin.fin_ifp = nat->nat_ifps[1]; if (getlock) { READ_ENTER(&ipf_nat); } n = nat_outlookup(&fin, nat->nat_flags, fin.fin_p, nat->nat_inip, nat->nat_oip); if (getlock) { RWLOCK_EXIT(&ipf_nat); } if (n != NULL) { error = EEXIST; goto junkput; } } else { error = EINVAL; goto junkput; } /* * Restore ap_session_t structure. Include the private data allocated * if it was there. */ aps = nat->nat_aps; if (aps != NULL) { KMALLOC(aps, ap_session_t *); nat->nat_aps = aps; if (aps == NULL) { error = ENOMEM; goto junkput; } bcopy(ipnn->ipn_data, (char *)aps, sizeof(*aps)); if (in != NULL) aps->aps_apr = in->in_apr; else aps->aps_apr = NULL; if (aps->aps_psiz != 0) { if (aps->aps_psiz > 81920) { error = ENOMEM; goto junkput; } KMALLOCS(aps->aps_data, void *, aps->aps_psiz); if (aps->aps_data == NULL) { error = ENOMEM; goto junkput; } bcopy(ipnn->ipn_data + sizeof(*aps), aps->aps_data, aps->aps_psiz); } else { aps->aps_psiz = 0; aps->aps_data = NULL; } } /* * If there was a filtering rule associated with this entry then * build up a new one. */ fr = nat->nat_fr; if (fr != NULL) { if ((nat->nat_flags & SI_NEWFR) != 0) { KMALLOC(fr, frentry_t *); nat->nat_fr = fr; if (fr == NULL) { error = ENOMEM; goto junkput; } ipnn->ipn_nat.nat_fr = fr; fr->fr_ref = 1; (void) fr_outobj(data, ipnn, IPFOBJ_NATSAVE); bcopy((char *)&ipnn->ipn_fr, (char *)fr, sizeof(*fr)); MUTEX_NUKE(&fr->fr_lock); MUTEX_INIT(&fr->fr_lock, "nat-filter rule lock"); } else { READ_ENTER(&ipf_nat); for (n = nat_instances; n; n = n->nat_next) if (n->nat_fr == fr) break; if (n != NULL) { MUTEX_ENTER(&fr->fr_lock); fr->fr_ref++; MUTEX_EXIT(&fr->fr_lock); } RWLOCK_EXIT(&ipf_nat); if (!n) { error = ESRCH; goto junkput; } } } if (ipnn != &ipn) { KFREES(ipnn, ipn.ipn_dsize); ipnn = NULL; } if (getlock) { WRITE_ENTER(&ipf_nat); } error = nat_insert(nat, nat->nat_rev); if ((error == 0) && (aps != NULL)) { aps->aps_next = ap_sess_list; ap_sess_list = aps; } if (getlock) { RWLOCK_EXIT(&ipf_nat); } if (error == 0) return 0; error = ENOMEM; junkput: if (fr != NULL) (void) fr_derefrule(&fr); if ((ipnn != NULL) && (ipnn != &ipn)) { KFREES(ipnn, ipn.ipn_dsize); } if (nat != NULL) { if (aps != NULL) { if (aps->aps_data != NULL) { KFREES(aps->aps_data, aps->aps_psiz); } KFREE(aps); } if (in != NULL) { if (in->in_apr) appr_free(in->in_apr); KFREE(in); } KFREE(nat); } return error; } /* ------------------------------------------------------------------------ */ /* Function: nat_delete */ /* Returns: Nil */ /* Parameters: natd(I) - pointer to NAT structure to delete */ /* logtype(I) - type of LOG record to create before deleting */ /* Write Lock: ipf_nat */ /* */ /* Delete a nat entry from the various lists and table. If NAT logging is */ /* enabled then generate a NAT log record for this event. */ /* ------------------------------------------------------------------------ */ static void nat_delete(nat, logtype) struct nat *nat; int logtype; { struct ipnat *ipn; if (logtype != 0 && nat_logging != 0) nat_log(nat, logtype); MUTEX_ENTER(&ipf_nat_new); /* * Take it as a general indication that all the pointers are set if * nat_pnext is set. */ if (nat->nat_pnext != NULL) { nat_stats.ns_bucketlen[0][nat->nat_hv[0]]--; nat_stats.ns_bucketlen[1][nat->nat_hv[1]]--; *nat->nat_pnext = nat->nat_next; if (nat->nat_next != NULL) { nat->nat_next->nat_pnext = nat->nat_pnext; nat->nat_next = NULL; } nat->nat_pnext = NULL; *nat->nat_phnext[0] = nat->nat_hnext[0]; if (nat->nat_hnext[0] != NULL) { nat->nat_hnext[0]->nat_phnext[0] = nat->nat_phnext[0]; nat->nat_hnext[0] = NULL; } nat->nat_phnext[0] = NULL; *nat->nat_phnext[1] = nat->nat_hnext[1]; if (nat->nat_hnext[1] != NULL) { nat->nat_hnext[1]->nat_phnext[1] = nat->nat_phnext[1]; nat->nat_hnext[1] = NULL; } nat->nat_phnext[1] = NULL; if ((nat->nat_flags & SI_WILDP) != 0) nat_stats.ns_wilds--; } if (nat->nat_me != NULL) { *nat->nat_me = NULL; nat->nat_me = NULL; } fr_deletequeueentry(&nat->nat_tqe); nat->nat_ref--; if (nat->nat_ref > 0) { MUTEX_EXIT(&ipf_nat_new); return; } #ifdef IPFILTER_SYNC if (nat->nat_sync) ipfsync_del(nat->nat_sync); #endif if (nat->nat_fr != NULL) (void)fr_derefrule(&nat->nat_fr); if (nat->nat_hm != NULL) nat_hostmapdel(nat->nat_hm); /* * If there is an active reference from the nat entry to its parent * rule, decrement the rule's reference count and free it too if no * longer being used. */ ipn = nat->nat_ptr; if (ipn != NULL) { ipn->in_space++; ipn->in_use--; if (ipn->in_use == 0 && (ipn->in_flags & IPN_DELETE)) { if (ipn->in_apr) appr_free(ipn->in_apr); KFREE(ipn); nat_stats.ns_rules--; #if SOLARIS if (nat_stats.ns_rules == 0) pfil_delayed_copy = 1; #endif } } MUTEX_DESTROY(&nat->nat_lock); aps_free(nat->nat_aps); nat_stats.ns_inuse--; MUTEX_EXIT(&ipf_nat_new); /* * If there's a fragment table entry too for this nat entry, then * dereference that as well. This is after nat_lock is released * because of Tru64. */ fr_forgetnat((void *)nat); KFREE(nat); } /* ------------------------------------------------------------------------ */ /* Function: nat_flushtable */ /* Returns: int - number of NAT rules deleted */ /* Parameters: Nil */ /* */ /* Deletes all currently active NAT sessions. In deleting each NAT entry a */ /* log record should be emitted in nat_delete() if NAT logging is enabled. */ /* ------------------------------------------------------------------------ */ /* * nat_flushtable - clear the NAT table of all mapping entries. */ static int nat_flushtable() { nat_t *nat; int j = 0; /* * ALL NAT mappings deleted, so lets just make the deletions * quicker. */ if (nat_table[0] != NULL) bzero((char *)nat_table[0], sizeof(nat_table[0]) * ipf_nattable_sz); if (nat_table[1] != NULL) bzero((char *)nat_table[1], sizeof(nat_table[1]) * ipf_nattable_sz); while ((nat = nat_instances) != NULL) { nat_delete(nat, NL_FLUSH); j++; } nat_stats.ns_inuse = 0; return j; } /* ------------------------------------------------------------------------ */ /* Function: nat_clearlist */ /* Returns: int - number of NAT/RDR rules deleted */ /* Parameters: Nil */ /* */ /* Delete all rules in the current list of rules. There is nothing elegant */ /* about this cleanup: simply free all entries on the list of rules and */ /* clear out the tables used for hashed NAT rule lookups. */ /* ------------------------------------------------------------------------ */ static int nat_clearlist() { ipnat_t *n, **np = &nat_list; int i = 0; if (nat_rules != NULL) bzero((char *)nat_rules, sizeof(*nat_rules) * ipf_natrules_sz); if (rdr_rules != NULL) bzero((char *)rdr_rules, sizeof(*rdr_rules) * ipf_rdrrules_sz); while ((n = *np) != NULL) { *np = n->in_next; if (n->in_use == 0) { if (n->in_apr != NULL) appr_free(n->in_apr); KFREE(n); nat_stats.ns_rules--; } else { n->in_flags |= IPN_DELETE; n->in_next = NULL; } i++; } #if SOLARIS pfil_delayed_copy = 1; #endif nat_masks = 0; rdr_masks = 0; return i; } /* ------------------------------------------------------------------------ */ /* Function: nat_newmap */ /* Returns: int - -1 == error, 0 == success */ /* Parameters: fin(I) - pointer to packet information */ /* nat(I) - pointer to NAT entry */ /* ni(I) - pointer to structure with misc. information needed */ /* to create new NAT entry. */ /* */ /* Given an empty NAT structure, populate it with new information about a */ /* new NAT session, as defined by the matching NAT rule. */ /* ni.nai_ip is passed in uninitialised and must be set, in host byte order,*/ /* to the new IP address for the translation. */ /* ------------------------------------------------------------------------ */ static INLINE int nat_newmap(fin, nat, ni) fr_info_t *fin; nat_t *nat; natinfo_t *ni; { u_short st_port, dport, sport, port, sp, dp; struct in_addr in, inb; hostmap_t *hm; u_32_t flags; u_32_t st_ip; ipnat_t *np; nat_t *natl; int l; /* * If it's an outbound packet which doesn't match any existing * record, then create a new port */ l = 0; hm = NULL; np = ni->nai_np; st_ip = np->in_nip; st_port = np->in_pnext; flags = ni->nai_flags; sport = ni->nai_sport; dport = ni->nai_dport; /* * Do a loop until we either run out of entries to try or we find * a NAT mapping that isn't currently being used. This is done * because the change to the source is not (usually) being fixed. */ do { port = 0; in.s_addr = htonl(np->in_nip); if (l == 0) { /* * Check to see if there is an existing NAT * setup for this IP address pair. */ hm = nat_hostmap(np, fin->fin_src, fin->fin_dst, in, 0); if (hm != NULL) in.s_addr = hm->hm_mapip.s_addr; } else if ((l == 1) && (hm != NULL)) { nat_hostmapdel(hm); hm = NULL; } in.s_addr = ntohl(in.s_addr); nat->nat_hm = hm; if ((np->in_outmsk == 0xffffffff) && (np->in_pnext == 0)) { if (l > 0) return -1; } if (np->in_redir == NAT_BIMAP && np->in_inmsk == np->in_outmsk) { /* * map the address block in a 1:1 fashion */ in.s_addr = np->in_outip; in.s_addr |= fin->fin_saddr & ~np->in_inmsk; in.s_addr = ntohl(in.s_addr); } else if (np->in_redir & NAT_MAPBLK) { if ((l >= np->in_ppip) || ((l > 0) && !(flags & IPN_TCPUDP))) return -1; /* * map-block - Calculate destination address. */ in.s_addr = ntohl(fin->fin_saddr); in.s_addr &= ntohl(~np->in_inmsk); inb.s_addr = in.s_addr; in.s_addr /= np->in_ippip; in.s_addr &= ntohl(~np->in_outmsk); in.s_addr += ntohl(np->in_outip); /* * Calculate destination port. */ if ((flags & IPN_TCPUDP) && (np->in_ppip != 0)) { port = ntohs(sport) + l; port %= np->in_ppip; port += np->in_ppip * (inb.s_addr % np->in_ippip); port += MAPBLK_MINPORT; port = htons(port); } } else if ((np->in_outip == 0) && (np->in_outmsk == 0xffffffff)) { /* * 0/32 - use the interface's IP address. */ if ((l > 0) || fr_ifpaddr(4, FRI_NORMAL, fin->fin_ifp, &in, NULL) == -1) return -1; in.s_addr = ntohl(in.s_addr); } else if ((np->in_outip == 0) && (np->in_outmsk == 0)) { /* * 0/0 - use the original source address/port. */ if (l > 0) return -1; in.s_addr = ntohl(fin->fin_saddr); } else if ((np->in_outmsk != 0xffffffff) && (np->in_pnext == 0) && ((l > 0) || (hm == NULL))) np->in_nip++; natl = NULL; if ((flags & IPN_TCPUDP) && ((np->in_redir & NAT_MAPBLK) == 0) && (np->in_flags & IPN_AUTOPORTMAP)) { /* * "ports auto" (without map-block) */ if ((l > 0) && (l % np->in_ppip == 0)) { if (l > np->in_space) { return -1; } else if ((l > np->in_ppip) && np->in_outmsk != 0xffffffff) np->in_nip++; } if (np->in_ppip != 0) { port = ntohs(sport); port += (l % np->in_ppip); port %= np->in_ppip; port += np->in_ppip * (ntohl(fin->fin_saddr) % np->in_ippip); port += MAPBLK_MINPORT; port = htons(port); } } else if (((np->in_redir & NAT_MAPBLK) == 0) && (flags & IPN_TCPUDPICMP) && (np->in_pnext != 0)) { /* * Standard port translation. Select next port. */ port = htons(np->in_pnext++); if (np->in_pnext > ntohs(np->in_pmax)) { np->in_pnext = ntohs(np->in_pmin); if (np->in_outmsk != 0xffffffff) np->in_nip++; } } if (np->in_flags & IPN_IPRANGE) { if (np->in_nip > ntohl(np->in_outmsk)) np->in_nip = ntohl(np->in_outip); } else { if ((np->in_outmsk != 0xffffffff) && ((np->in_nip + 1) & ntohl(np->in_outmsk)) > ntohl(np->in_outip)) np->in_nip = ntohl(np->in_outip) + 1; } if ((port == 0) && (flags & (IPN_TCPUDPICMP|IPN_ICMPQUERY))) port = sport; /* * Here we do a lookup of the connection as seen from * the outside. If an IP# pair already exists, try * again. So if you have A->B becomes C->B, you can * also have D->E become C->E but not D->B causing * another C->B. Also take protocol and ports into * account when determining whether a pre-existing * NAT setup will cause an external conflict where * this is appropriate. */ inb.s_addr = htonl(in.s_addr); sp = fin->fin_data[0]; dp = fin->fin_data[1]; fin->fin_data[0] = fin->fin_data[1]; fin->fin_data[1] = htons(port); natl = nat_inlookup(fin, flags & ~(SI_WILDP|NAT_SEARCH), (u_int)fin->fin_p, fin->fin_dst, inb); fin->fin_data[0] = sp; fin->fin_data[1] = dp; /* * Has the search wrapped around and come back to the * start ? */ if ((natl != NULL) && (np->in_pnext != 0) && (st_port == np->in_pnext) && (np->in_nip != 0) && (st_ip == np->in_nip)) return -1; l++; } while (natl != NULL); if (np->in_space > 0) np->in_space--; /* Setup the NAT table */ nat->nat_inip = fin->fin_src; nat->nat_outip.s_addr = htonl(in.s_addr); nat->nat_oip = fin->fin_dst; if (nat->nat_hm == NULL) nat->nat_hm = nat_hostmap(np, fin->fin_src, fin->fin_dst, nat->nat_outip, 0); /* * The ICMP checksum does not have a pseudo header containing * the IP addresses */ ni->nai_sum1 = LONG_SUM(ntohl(fin->fin_saddr)); ni->nai_sum2 = LONG_SUM(in.s_addr); if ((flags & IPN_TCPUDP)) { ni->nai_sum1 += ntohs(sport); ni->nai_sum2 += ntohs(port); } if (flags & IPN_TCPUDP) { nat->nat_inport = sport; nat->nat_outport = port; /* sport */ nat->nat_oport = dport; ((tcphdr_t *)fin->fin_dp)->th_sport = port; } else if (flags & IPN_ICMPQUERY) { ((icmphdr_t *)fin->fin_dp)->icmp_id = port; nat->nat_inport = port; nat->nat_outport = port; } ni->nai_ip.s_addr = in.s_addr; ni->nai_port = port; ni->nai_nport = dport; return 0; } /* ------------------------------------------------------------------------ */ /* Function: nat_newrdr */ /* Returns: int - -1 == error, 0 == success (no move), 1 == success and */ /* allow rule to be moved if IPN_ROUNDR is set. */ /* Parameters: fin(I) - pointer to packet information */ /* nat(I) - pointer to NAT entry */ /* ni(I) - pointer to structure with misc. information needed */ /* to create new NAT entry. */ /* */ /* ni.nai_ip is passed in uninitialised and must be set, in host byte order,*/ /* to the new IP address for the translation. */ /* ------------------------------------------------------------------------ */ static INLINE int nat_newrdr(fin, nat, ni) fr_info_t *fin; nat_t *nat; natinfo_t *ni; { u_short nport, dport, sport; struct in_addr in; hostmap_t *hm; u_32_t flags; ipnat_t *np; int move; move = 1; hm = NULL; in.s_addr = 0; np = ni->nai_np; flags = ni->nai_flags; sport = ni->nai_sport; dport = ni->nai_dport; /* * If the matching rule has IPN_STICKY set, then we want to have the * same rule kick in as before. Why would this happen? If you have * a collection of rdr rules with "round-robin sticky", the current * packet might match a different one to the previous connection but * we want the same destination to be used. */ if ((np->in_flags & (IPN_ROUNDR|IPN_STICKY)) == (IPN_ROUNDR|IPN_STICKY)) { hm = nat_hostmap(NULL, fin->fin_src, fin->fin_dst, in, (u_32_t)dport); if (hm != NULL) { in.s_addr = ntohl(hm->hm_mapip.s_addr); np = hm->hm_ipnat; ni->nai_np = np; move = 0; } } /* * Otherwise, it's an inbound packet. Most likely, we don't * want to rewrite source ports and source addresses. Instead, * we want to rewrite to a fixed internal address and fixed * internal port. */ if (np->in_flags & IPN_SPLIT) { in.s_addr = np->in_nip; if ((np->in_flags & (IPN_ROUNDR|IPN_STICKY)) == IPN_STICKY) { hm = nat_hostmap(np, fin->fin_src, fin->fin_dst, in, (u_32_t)dport); if (hm != NULL) { in.s_addr = hm->hm_mapip.s_addr; move = 0; } } if (hm == NULL || hm->hm_ref == 1) { if (np->in_inip == htonl(in.s_addr)) { np->in_nip = ntohl(np->in_inmsk); move = 0; } else { np->in_nip = ntohl(np->in_inip); } } } else if ((np->in_inip == 0) && (np->in_inmsk == 0xffffffff)) { /* * 0/32 - use the interface's IP address. */ if (fr_ifpaddr(4, FRI_NORMAL, fin->fin_ifp, &in, NULL) == -1) return -1; in.s_addr = ntohl(in.s_addr); } else if ((np->in_inip == 0) && (np->in_inmsk== 0)) { /* * 0/0 - use the original destination address/port. */ in.s_addr = ntohl(fin->fin_daddr); } else if (np->in_redir == NAT_BIMAP && np->in_inmsk == np->in_outmsk) { /* * map the address block in a 1:1 fashion */ in.s_addr = np->in_inip; in.s_addr |= fin->fin_daddr & ~np->in_inmsk; in.s_addr = ntohl(in.s_addr); } else { in.s_addr = ntohl(np->in_inip); } if ((np->in_pnext == 0) || ((flags & NAT_NOTRULEPORT) != 0)) nport = dport; else { /* * Whilst not optimized for the case where * pmin == pmax, the gain is not significant. */ if (((np->in_flags & IPN_FIXEDDPORT) == 0) && (np->in_pmin != np->in_pmax)) { nport = ntohs(dport) - ntohs(np->in_pmin) + ntohs(np->in_pnext); nport = htons(nport); } else nport = np->in_pnext; } /* * When the redirect-to address is set to 0.0.0.0, just * assume a blank `forwarding' of the packet. We don't * setup any translation for this either. */ if (in.s_addr == 0) { if (nport == dport) return -1; in.s_addr = ntohl(fin->fin_daddr); } nat->nat_inip.s_addr = htonl(in.s_addr); nat->nat_outip = fin->fin_dst; nat->nat_oip = fin->fin_src; ni->nai_sum1 = LONG_SUM(ntohl(fin->fin_daddr)) + ntohs(dport); ni->nai_sum2 = LONG_SUM(in.s_addr) + ntohs(nport); ni->nai_ip.s_addr = in.s_addr; ni->nai_nport = nport; ni->nai_port = sport; if (flags & IPN_TCPUDP) { nat->nat_inport = nport; nat->nat_outport = dport; nat->nat_oport = sport; ((tcphdr_t *)fin->fin_dp)->th_dport = nport; } else if (flags & IPN_ICMPQUERY) { ((icmphdr_t *)fin->fin_dp)->icmp_id = nport; nat->nat_inport = nport; nat->nat_outport = nport; } return move; } /* ------------------------------------------------------------------------ */ /* Function: nat_new */ /* Returns: nat_t* - NULL == failure to create new NAT structure, */ /* else pointer to new NAT structure */ /* Parameters: fin(I) - pointer to packet information */ /* np(I) - pointer to NAT rule */ /* natsave(I) - pointer to where to store NAT struct pointer */ /* flags(I) - flags describing the current packet */ /* direction(I) - direction of packet (in/out) */ /* Write Lock: ipf_nat */ /* */ /* Attempts to create a new NAT entry. Does not actually change the packet */ /* in any way. */ /* */ /* This fucntion is in three main parts: (1) deal with creating a new NAT */ /* structure for a "MAP" rule (outgoing NAT translation); (2) deal with */ /* creating a new NAT structure for a "RDR" rule (incoming NAT translation) */ /* and (3) building that structure and putting it into the NAT table(s). */ /* ------------------------------------------------------------------------ */ nat_t *nat_new(fin, np, natsave, flags, direction) fr_info_t *fin; ipnat_t *np; nat_t **natsave; u_int flags; int direction; { u_short port = 0, sport = 0, dport = 0, nport = 0; tcphdr_t *tcp = NULL; hostmap_t *hm = NULL; struct in_addr in; nat_t *nat, *natl; u_int nflags; natinfo_t ni; u_32_t sumd; int move; #if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) && defined(ICK_M_CTL_MAGIC) qpktinfo_t *qpi = fin->fin_qpi; #endif if (nat_stats.ns_inuse >= ipf_nattable_max) { nat_stats.ns_memfail++; return NULL; } move = 1; nflags = np->in_flags & flags; nflags &= NAT_FROMRULE; ni.nai_np = np; ni.nai_nflags = nflags; ni.nai_flags = flags; /* Give me a new nat */ KMALLOC(nat, nat_t *); if (nat == NULL) { nat_stats.ns_memfail++; /* * Try to automatically tune the max # of entries in the * table allowed to be less than what will cause kmem_alloc() * to fail and try to eliminate panics due to out of memory * conditions arising. */ if (ipf_nattable_max > ipf_nattable_sz) { ipf_nattable_max = nat_stats.ns_inuse - 100; printf("ipf_nattable_max reduced to %d\n", ipf_nattable_max); } return NULL; } if (flags & IPN_TCPUDP) { tcp = fin->fin_dp; ni.nai_sport = htons(fin->fin_sport); ni.nai_dport = htons(fin->fin_dport); } else if (flags & IPN_ICMPQUERY) { /* * In the ICMP query NAT code, we translate the ICMP id fields * to make them unique. This is indepedent of the ICMP type * (e.g. in the unlikely event that a host sends an echo and * an tstamp request with the same id, both packets will have * their ip address/id field changed in the same way). */ /* The icmp_id field is used by the sender to identify the * process making the icmp request. (the receiver justs * copies it back in its response). So, it closely matches * the concept of source port. We overlay sport, so we can * maximally reuse the existing code. */ ni.nai_sport = ((icmphdr_t *)fin->fin_dp)->icmp_id; ni.nai_dport = ni.nai_sport; } bzero((char *)nat, sizeof(*nat)); nat->nat_flags = flags; if ((flags & NAT_SLAVE) == 0) { MUTEX_ENTER(&ipf_nat_new); } /* * Search the current table for a match. */ if (direction == NAT_OUTBOUND) { /* * We can now arrange to call this for the same connection * because ipf_nat_new doesn't protect the code path into * this function. */ natl = nat_outlookup(fin, nflags, (u_int)fin->fin_p, fin->fin_src, fin->fin_dst); if (natl != NULL) { nat = natl; goto done; } move = nat_newmap(fin, nat, &ni); if (move == -1) goto badnat; np = ni.nai_np; in = ni.nai_ip; } else { /* * NAT_INBOUND is used only for redirects rules */ natl = nat_inlookup(fin, nflags, (u_int)fin->fin_p, fin->fin_src, fin->fin_dst); if (natl != NULL) { nat = natl; goto done; } move = nat_newrdr(fin, nat, &ni); if (move == -1) goto badnat; np = ni.nai_np; in = ni.nai_ip; } port = ni.nai_port; nport = ni.nai_nport; if ((move == 1) && (np->in_flags & IPN_ROUNDR)) { if (np->in_redir == NAT_REDIRECT) { nat_delrdr(np); nat_addrdr(np); } else if (np->in_redir == NAT_MAP) { nat_delnat(np); nat_addnat(np); } } if (flags & IPN_TCPUDP) { sport = ni.nai_sport; dport = ni.nai_dport; } else if (flags & IPN_ICMPQUERY) { sport = ni.nai_sport; dport = 0; } CALC_SUMD(ni.nai_sum1, ni.nai_sum2, sumd); nat->nat_sumd[0] = (sumd & 0xffff) + (sumd >> 16); #if SOLARIS && defined(_KERNEL) && (SOLARIS2 >= 6) && defined(ICK_M_CTL_MAGIC) if ((flags & IPN_TCP) && dohwcksum && #ifndef IRE_ILL_CN (((ill_t *)qpi->qpi_ill)->ill_ick.ick_magic == ICK_M_CTL_MAGIC)) { #else (((s_ill_t *)qpi->qpi_ill)->ill_ick.ick_magic == ICK_M_CTL_MAGIC)) { #endif /* IRE_ILL_CN */ if (direction == NAT_OUTBOUND) ni.nai_sum1 = LONG_SUM(in.s_addr); else ni.nai_sum1 = LONG_SUM(ntohl(fin->fin_saddr)); ni.nai_sum1 += LONG_SUM(ntohl(fin->fin_daddr)); ni.nai_sum1 += 30; ni.nai_sum1 = (ni.nai_sum1 & 0xffff) + (ni.nai_sum1 >> 16); nat->nat_sumd[1] = NAT_HW_CKSUM|(ni.nai_sum1 & 0xffff); } else #endif nat->nat_sumd[1] = nat->nat_sumd[0]; if ((flags & IPN_TCPUDPICMP) && ((sport != port) || (dport != nport))) { if (direction == NAT_OUTBOUND) ni.nai_sum1 = LONG_SUM(ntohl(fin->fin_saddr)); else ni.nai_sum1 = LONG_SUM(ntohl(fin->fin_daddr)); ni.nai_sum2 = LONG_SUM(in.s_addr); CALC_SUMD(ni.nai_sum1, ni.nai_sum2, sumd); nat->nat_ipsumd = (sumd & 0xffff) + (sumd >> 16); } else { nat->nat_ipsumd = nat->nat_sumd[0]; if (!(flags & IPN_TCPUDPICMP)) { nat->nat_sumd[0] = 0; nat->nat_sumd[1] = 0; } } if (nat_finalise(fin, nat, &ni, tcp, natsave, direction) == -1) { goto badnat; } if (flags & SI_WILDP) nat_stats.ns_wilds++; goto done; badnat: nat_stats.ns_badnat++; if ((hm = nat->nat_hm) != NULL) nat_hostmapdel(hm); KFREE(nat); nat = NULL; done: if ((flags & NAT_SLAVE) == 0) { MUTEX_EXIT(&ipf_nat_new); } return nat; } /* ------------------------------------------------------------------------ */ /* Function: nat_finalise */ /* Returns: int - 0 == sucess, -1 == failure */ /* Parameters: fin(I) - pointer to packet information */ /* nat(I) - pointer to NAT entry */ /* ni(I) - pointer to structure with misc. information needed */ /* to create new NAT entry. */ /* Write Lock: ipf_nat */ /* */ /* This is the tail end of constructing a new NAT entry and is the same */ /* for both IPv4 and IPv6. */ /* ------------------------------------------------------------------------ */ /*ARGSUSED*/ static INLINE int nat_finalise(fin, nat, ni, tcp, natsave, direction) fr_info_t *fin; nat_t *nat; natinfo_t *ni; tcphdr_t *tcp; nat_t **natsave; int direction; { frentry_t *fr; ipnat_t *np; np = ni->nai_np; if (np->in_ifps[0] != NULL) { (void) COPYIFNAME(np->in_ifps[0], nat->nat_ifnames[0]); } if (np->in_ifps[1] != NULL) { (void) COPYIFNAME(np->in_ifps[1], nat->nat_ifnames[1]); } #ifdef IPFILTER_SYNC if ((nat->nat_flags & SI_CLONE) == 0) nat->nat_sync = ipfsync_new(SMC_NAT, fin, nat); #endif nat->nat_me = natsave; nat->nat_dir = direction; nat->nat_ifps[0] = np->in_ifps[0]; nat->nat_ifps[1] = np->in_ifps[1]; nat->nat_ptr = np; nat->nat_p = fin->fin_p; nat->nat_mssclamp = np->in_mssclamp; fr = fin->fin_fr; nat->nat_fr = fr; if ((np->in_apr != NULL) && ((ni->nai_flags & NAT_SLAVE) == 0)) if (appr_new(fin, nat) == -1) return -1; if (nat_insert(nat, fin->fin_rev) == 0) { if (nat_logging) nat_log(nat, (u_int)np->in_redir); np->in_use++; if (fr != NULL) { MUTEX_ENTER(&fr->fr_lock); fr->fr_ref++; MUTEX_EXIT(&fr->fr_lock); } return 0; } /* * nat_insert failed, so cleanup time... */ return -1; } /* ------------------------------------------------------------------------ */ /* Function: nat_insert */ /* Returns: int - 0 == sucess, -1 == failure */ /* Parameters: nat(I) - pointer to NAT structure */ /* rev(I) - flag indicating forward/reverse direction of packet */ /* Write Lock: ipf_nat */ /* */ /* Insert a NAT entry into the hash tables for searching and add it to the */ /* list of active NAT entries. Adjust global counters when complete. */ /* ------------------------------------------------------------------------ */ int nat_insert(nat, rev) nat_t *nat; int rev; { u_int hv1, hv2; nat_t **natp; /* * Try and return an error as early as possible, so calculate the hash * entry numbers first and then proceed. */ if ((nat->nat_flags & (SI_W_SPORT|SI_W_DPORT)) == 0) { hv1 = NAT_HASH_FN(nat->nat_inip.s_addr, nat->nat_inport, 0xffffffff); hv1 = NAT_HASH_FN(nat->nat_oip.s_addr, hv1 + nat->nat_oport, ipf_nattable_sz); hv2 = NAT_HASH_FN(nat->nat_outip.s_addr, nat->nat_outport, 0xffffffff); hv2 = NAT_HASH_FN(nat->nat_oip.s_addr, hv2 + nat->nat_oport, ipf_nattable_sz); } else { hv1 = NAT_HASH_FN(nat->nat_inip.s_addr, 0, 0xffffffff); hv1 = NAT_HASH_FN(nat->nat_oip.s_addr, hv1, ipf_nattable_sz); hv2 = NAT_HASH_FN(nat->nat_outip.s_addr, 0, 0xffffffff); hv2 = NAT_HASH_FN(nat->nat_oip.s_addr, hv2, ipf_nattable_sz); } if (nat_stats.ns_bucketlen[0][hv1] >= fr_nat_maxbucket || nat_stats.ns_bucketlen[1][hv2] >= fr_nat_maxbucket) { return -1; } nat->nat_hv[0] = hv1; nat->nat_hv[1] = hv2; MUTEX_INIT(&nat->nat_lock, "nat entry lock"); nat->nat_rev = rev; nat->nat_ref = 1; nat->nat_bytes[0] = 0; nat->nat_pkts[0] = 0; nat->nat_bytes[1] = 0; nat->nat_pkts[1] = 0; nat->nat_ifnames[0][LIFNAMSIZ - 1] = '\0'; nat->nat_ifps[0] = fr_resolvenic(nat->nat_ifnames[0], 4); if (nat->nat_ifnames[1][0] !='\0') { nat->nat_ifnames[1][LIFNAMSIZ - 1] = '\0'; nat->nat_ifps[1] = fr_resolvenic(nat->nat_ifnames[1], 4); } else { (void) strncpy(nat->nat_ifnames[1], nat->nat_ifnames[0], LIFNAMSIZ); nat->nat_ifnames[1][LIFNAMSIZ - 1] = '\0'; nat->nat_ifps[1] = nat->nat_ifps[0]; } nat->nat_next = nat_instances; nat->nat_pnext = &nat_instances; if (nat_instances) nat_instances->nat_pnext = &nat->nat_next; nat_instances = nat; natp = &nat_table[0][hv1]; if (*natp) (*natp)->nat_phnext[0] = &nat->nat_hnext[0]; nat->nat_phnext[0] = natp; nat->nat_hnext[0] = *natp; *natp = nat; nat_stats.ns_bucketlen[0][hv1]++; natp = &nat_table[1][hv2]; if (*natp) (*natp)->nat_phnext[1] = &nat->nat_hnext[1]; nat->nat_phnext[1] = natp; nat->nat_hnext[1] = *natp; *natp = nat; nat_stats.ns_bucketlen[1][hv2]++; fr_setnatqueue(nat, rev); nat_stats.ns_added++; nat_stats.ns_inuse++; return 0; } /* ------------------------------------------------------------------------ */ /* Function: nat_icmperrorlookup */ /* Returns: nat_t* - point to matching NAT structure */ /* Parameters: fin(I) - pointer to packet information */ /* dir(I) - direction of packet (in/out) */ /* */ /* Check if the ICMP error message is related to an existing TCP, UDP or */ /* ICMP query nat entry. It is assumed that the packet is already of the */ /* the required length. */ /* ------------------------------------------------------------------------ */ nat_t *nat_icmperrorlookup(fin, dir) fr_info_t *fin; int dir; { int flags = 0, minlen; icmphdr_t *orgicmp; tcphdr_t *tcp = NULL; u_short data[2]; nat_t *nat; ip_t *oip; u_int p; /* * Does it at least have the return (basic) IP header ? * Only a basic IP header (no options) should be with an ICMP error * header. Also, if it's not an error type, then return. */ if ((fin->fin_hlen != sizeof(ip_t)) || !(fin->fin_flx & FI_ICMPERR)) return NULL; /* * Check packet size */ oip = (ip_t *)((char *)fin->fin_dp + 8); minlen = IP_HL(oip) << 2; if ((minlen < sizeof(ip_t)) || (fin->fin_plen < ICMPERR_IPICMPHLEN + minlen)) return NULL; /* * Is the buffer big enough for all of it ? It's the size of the IP * header claimed in the encapsulated part which is of concern. It * may be too big to be in this buffer but not so big that it's * outside the ICMP packet, leading to TCP deref's causing problems. * This is possible because we don't know how big oip_hl is when we * do the pullup early in fr_check() and thus can't gaurantee it is * all here now. */ #ifdef _KERNEL { mb_t *m; m = fin->fin_m; # if defined(MENTAT) if ((char *)oip + fin->fin_dlen - ICMPERR_ICMPHLEN > (char *)m->b_wptr) return NULL; # else if ((char *)oip + fin->fin_dlen - ICMPERR_ICMPHLEN > (char *)fin->fin_ip + M_LEN(m)) return NULL; # endif } #endif if (fin->fin_daddr != oip->ip_src.s_addr) return NULL; p = oip->ip_p; if (p == IPPROTO_TCP) flags = IPN_TCP; else if (p == IPPROTO_UDP) flags = IPN_UDP; else if (p == IPPROTO_ICMP) { orgicmp = (icmphdr_t *)((char *)oip + (IP_HL(oip) << 2)); /* see if this is related to an ICMP query */ if (nat_icmpquerytype4(orgicmp->icmp_type)) { data[0] = fin->fin_data[0]; data[1] = fin->fin_data[1]; fin->fin_data[0] = 0; fin->fin_data[1] = orgicmp->icmp_id; flags = IPN_ICMPERR|IPN_ICMPQUERY; /* * NOTE : dir refers to the direction of the original * ip packet. By definition the icmp error * message flows in the opposite direction. */ if (dir == NAT_INBOUND) nat = nat_inlookup(fin, flags, p, oip->ip_dst, oip->ip_src); else nat = nat_outlookup(fin, flags, p, oip->ip_dst, oip->ip_src); fin->fin_data[0] = data[0]; fin->fin_data[1] = data[1]; return nat; } } if (flags & IPN_TCPUDP) { minlen += 8; /* + 64bits of data to get ports */ if (fin->fin_plen < ICMPERR_IPICMPHLEN + minlen) return NULL; data[0] = fin->fin_data[0]; data[1] = fin->fin_data[1]; tcp = (tcphdr_t *)((char *)oip + (IP_HL(oip) << 2)); fin->fin_data[0] = ntohs(tcp->th_dport); fin->fin_data[1] = ntohs(tcp->th_sport); if (dir == NAT_INBOUND) { nat = nat_inlookup(fin, flags, p, oip->ip_dst, oip->ip_src); } else { nat = nat_outlookup(fin, flags, p, oip->ip_dst, oip->ip_src); } fin->fin_data[0] = data[0]; fin->fin_data[1] = data[1]; return nat; } if (dir == NAT_INBOUND) return nat_inlookup(fin, 0, p, oip->ip_dst, oip->ip_src); else return nat_outlookup(fin, 0, p, oip->ip_dst, oip->ip_src); } /* ------------------------------------------------------------------------ */ /* Function: nat_icmperror */ /* Returns: nat_t* - point to matching NAT structure */ /* Parameters: fin(I) - pointer to packet information */ /* nflags(I) - NAT flags for this packet */ /* dir(I) - direction of packet (in/out) */ /* */ /* Fix up an ICMP packet which is an error message for an existing NAT */ /* session. This will correct both packet header data and checksums. */ /* */ /* This should *ONLY* be used for incoming ICMP error packets to make sure */ /* a NAT'd ICMP packet gets correctly recognised. */ /* ------------------------------------------------------------------------ */ nat_t *nat_icmperror(fin, nflags, dir) fr_info_t *fin; u_int *nflags; int dir; { u_32_t sum1, sum2, sumd, sumd2; struct in_addr in; icmphdr_t *icmp; int flags, dlen; u_short *csump; tcphdr_t *tcp; nat_t *nat; ip_t *oip; void *dp; if ((fin->fin_flx & (FI_SHORT|FI_FRAGBODY))) return NULL; /* * nat_icmperrorlookup() will return NULL for `defective' packets. */ if ((fin->fin_v != 4) || !(nat = nat_icmperrorlookup(fin, dir))) return NULL; tcp = NULL; csump = NULL; flags = 0; sumd2 = 0; *nflags = IPN_ICMPERR; icmp = fin->fin_dp; oip = (ip_t *)&icmp->icmp_ip; dp = (((char *)oip) + (IP_HL(oip) << 2)); if (oip->ip_p == IPPROTO_TCP) { tcp = (tcphdr_t *)dp; csump = (u_short *)&tcp->th_sum; flags = IPN_TCP; } else if (oip->ip_p == IPPROTO_UDP) { udphdr_t *udp; udp = (udphdr_t *)dp; tcp = (tcphdr_t *)dp; csump = (u_short *)&udp->uh_sum; flags = IPN_UDP; } else if (oip->ip_p == IPPROTO_ICMP) flags = IPN_ICMPQUERY; dlen = fin->fin_plen - ((char *)dp - (char *)fin->fin_ip); /* * Need to adjust ICMP header to include the real IP#'s and * port #'s. Only apply a checksum change relative to the * IP address change as it will be modified again in fr_checknatout * for both address and port. Two checksum changes are * necessary for the two header address changes. Be careful * to only modify the checksum once for the port # and twice * for the IP#. */ /* * Step 1 * Fix the IP addresses in the offending IP packet. You also need * to adjust the IP header checksum of that offending IP packet * and the ICMP checksum of the ICMP error message itself. * * Unfortunately, for UDP and TCP, the IP addresses are also contained * in the pseudo header that is used to compute the UDP resp. TCP * checksum. So, we must compensate that as well. Even worse, the * change in the UDP and TCP checksums require yet another * adjustment of the ICMP checksum of the ICMP error message. */ if (oip->ip_dst.s_addr == nat->nat_oip.s_addr) { sum1 = LONG_SUM(ntohl(oip->ip_src.s_addr)); in = nat->nat_inip; oip->ip_src = in; } else { sum1 = LONG_SUM(ntohl(oip->ip_dst.s_addr)); in = nat->nat_outip; oip->ip_dst = in; } sum2 = LONG_SUM(ntohl(in.s_addr)); CALC_SUMD(sum1, sum2, sumd); /* * Fix IP checksum of the offending IP packet to adjust for * the change in the IP address. * * Normally, you would expect that the ICMP checksum of the * ICMP error message needs to be adjusted as well for the * IP address change in oip. * However, this is a NOP, because the ICMP checksum is * calculated over the complete ICMP packet, which includes the * changed oip IP addresses and oip->ip_sum. However, these * two changes cancel each other out (if the delta for * the IP address is x, then the delta for ip_sum is minus x), * so no change in the icmp_cksum is necessary. * * Be careful that nat_dir refers to the direction of the * offending IP packet (oip), not to its ICMP response (icmp) */ fix_datacksum(&oip->ip_sum, sumd); /* Fix icmp cksum : IP Addr + Cksum */ sumd2 = (sumd >> 16); /* * Fix UDP pseudo header checksum to compensate for the * IP address change. */ if ((oip->ip_p == IPPROTO_UDP) && (dlen >= 8) && (*csump != 0)) { /* * The UDP checksum is optional, only adjust it * if it has been set. */ sum1 = ntohs(*csump); fix_datacksum(csump, sumd); sum2 = ntohs(*csump); /* * Fix ICMP checksum to compensate the UDP * checksum adjustment. */ sumd2 = sumd << 1; CALC_SUMD(sum1, sum2, sumd); sumd2 += sumd; } /* * Fix TCP pseudo header checksum to compensate for the * IP address change. Before we can do the change, we * must make sure that oip is sufficient large to hold * the TCP checksum (normally it does not!). * 18 = offsetof(tcphdr_t, th_sum) + 2 */ else if (oip->ip_p == IPPROTO_TCP && dlen >= 18) { sum1 = ntohs(*csump); fix_datacksum(csump, sumd); sum2 = ntohs(*csump); /* * Fix ICMP checksum to compensate the TCP * checksum adjustment. */ sumd2 = sumd << 1; CALC_SUMD(sum1, sum2, sumd); sumd2 += sumd; } else { if (nat->nat_dir == NAT_OUTBOUND) sumd2 = ~sumd2; else sumd2 = ~sumd2 + 1; } if (((flags & IPN_TCPUDP) != 0) && (dlen >= 4)) { int mode = 0; /* * Step 2 : * For offending TCP/UDP IP packets, translate the ports as * well, based on the NAT specification. Of course such * a change must be reflected in the ICMP checksum as well. * * Advance notice : Now it becomes complicated :-) * * Since the port fields are part of the TCP/UDP checksum * of the offending IP packet, you need to adjust that checksum * as well... but, if you change, you must change the icmp * checksum *again*, to reflect that change. * * To further complicate: the TCP checksum is not in the first * 8 bytes of the offending ip packet, so it most likely is not * available. Some OSses like Solaris return enough bytes to * include the TCP checksum. So we have to check if the * ip->ip_len actually holds the TCP checksum of the oip! */ if (nat->nat_oport == tcp->th_dport) { if (tcp->th_sport != nat->nat_inport) { mode = 1; sum1 = ntohs(nat->nat_inport); sum2 = ntohs(tcp->th_sport); } } else if (tcp->th_sport == nat->nat_oport) { mode = 2; sum1 = ntohs(nat->nat_outport); sum2 = ntohs(tcp->th_dport); } if (mode == 1) { /* * Fix ICMP checksum to compensate port adjustment. */ tcp->th_sport = htons(sum1); /* * Fix udp checksum to compensate port adjustment. * NOTE : the offending IP packet flows the other * direction compared to the ICMP message. * * The UDP checksum is optional, only adjust it if * it has been set. */ if ((oip->ip_p == IPPROTO_UDP) && (dlen >= 8) && (*csump != 0)) { sumd = sum1 - sum2; sumd2 += sumd; sum1 = ntohs(*csump); fix_datacksum(csump, sumd); sum2 = ntohs(*csump); /* * Fix ICMP checksum to compenstate * UDP checksum adjustment. */ CALC_SUMD(sum1, sum2, sumd); sumd2 += sumd; } /* * Fix TCP checksum (if present) to compensate port * adjustment. NOTE : the offending IP packet flows * the other direction compared to the ICMP message. */ if (oip->ip_p == IPPROTO_TCP) { if (dlen >= 18) { sumd = sum1 - sum2; sumd2 += sumd; sum1 = ntohs(*csump); fix_datacksum(csump, sumd); sum2 = ntohs(*csump); /* * Fix ICMP checksum to compensate * TCP checksum adjustment. */ CALC_SUMD(sum1, sum2, sumd); sumd2 += sumd; } else { sumd = sum2 - sum1 + 1; sumd2 += sumd; } } } else if (mode == 2) { /* * Fix ICMP checksum to compensate port adjustment. */ tcp->th_dport = htons(sum1); /* * Fix UDP checksum to compensate port adjustment. * NOTE : the offending IP packet flows the other * direction compared to the ICMP message. * * The UDP checksum is optional, only adjust * it if it has been set. */ if ((oip->ip_p == IPPROTO_UDP) && (dlen >= 8) && (*csump != 0)) { sumd = sum1 - sum2; sumd2 += sumd; sum1 = ntohs(*csump); fix_datacksum(csump, sumd); sum2 = ntohs(*csump); /* * Fix ICMP checksum to compensate * UDP checksum adjustment. */ CALC_SUMD(sum1, sum2, sumd); sumd2 += sumd; } /* * Fix TCP checksum (if present) to compensate port * adjustment. NOTE : the offending IP packet flows * the other direction compared to the ICMP message. */ if (oip->ip_p == IPPROTO_TCP) { if (dlen >= 18) { sumd = sum1 - sum2; sumd2 += sumd; sum1 = ntohs(*csump); fix_datacksum(csump, sumd); sum2 = ntohs(*csump); /* * Fix ICMP checksum to compensate * TCP checksum adjustment. */ CALC_SUMD(sum1, sum2, sumd); sumd2 += sumd; } else { if (nat->nat_dir == NAT_INBOUND) sumd = sum2 - sum1; else sumd = sum2 - sum1 + 1; sumd2 += sumd; } } } if (sumd2 != 0) { sumd2 = (sumd2 & 0xffff) + (sumd2 >> 16); sumd2 = (sumd2 & 0xffff) + (sumd2 >> 16); fix_incksum(fin, &icmp->icmp_cksum, sumd2); } } else if (((flags & IPN_ICMPQUERY) != 0) && (dlen >= 8)) { icmphdr_t *orgicmp; /* * XXX - what if this is bogus hl and we go off the end ? * In this case, nat_icmperrorlookup() will have returned NULL. */ orgicmp = (icmphdr_t *)dp; if (nat->nat_dir == NAT_OUTBOUND) { if (orgicmp->icmp_id != nat->nat_inport) { /* * Fix ICMP checksum (of the offening ICMP * query packet) to compensate the change * in the ICMP id of the offending ICMP * packet. * * Since you modify orgicmp->icmp_id with * a delta (say x) and you compensate that * in origicmp->icmp_cksum with a delta * minus x, you don't have to adjust the * overall icmp->icmp_cksum */ sum1 = ntohs(orgicmp->icmp_id); sum2 = ntohs(nat->nat_inport); CALC_SUMD(sum1, sum2, sumd); orgicmp->icmp_id = nat->nat_inport; fix_datacksum(&orgicmp->icmp_cksum, sumd); } } /* nat_dir == NAT_INBOUND is impossible for icmp queries */ } return nat; } /* * NB: these lookups don't lock access to the list, it assumed that it has * already been done! */ /* ------------------------------------------------------------------------ */ /* Function: nat_inlookup */ /* Returns: nat_t* - NULL == no match, */ /* else pointer to matching NAT entry */ /* Parameters: fin(I) - pointer to packet information */ /* flags(I) - NAT flags for this packet */ /* p(I) - protocol for this packet */ /* src(I) - source IP address */ /* mapdst(I) - destination IP address */ /* */ /* Lookup a nat entry based on the mapped destination ip address/port and */ /* real source address/port. We use this lookup when receiving a packet, */ /* we're looking for a table entry, based on the destination address. */ /* */ /* NOTE: THE PACKET BEING CHECKED (IF FOUND) HAS A MAPPING ALREADY. */ /* */ /* NOTE: IT IS ASSUMED THAT ipf_nat IS ONLY HELD WITH A READ LOCK WHEN */ /* THIS FUNCTION IS CALLED WITH NAT_SEARCH SET IN nflags. */ /* */ /* flags -> relevant are IPN_UDP/IPN_TCP/IPN_ICMPQUERY that indicate if */ /* the packet is of said protocol */ /* ------------------------------------------------------------------------ */ nat_t *nat_inlookup(fin, flags, p, src, mapdst) fr_info_t *fin; u_int flags, p; struct in_addr src , mapdst; { u_short sport, dport; ipnat_t *ipn; u_int sflags; nat_t *nat; int nflags; u_32_t dst; void *ifp; u_int hv; if (fin != NULL) ifp = fin->fin_ifp; else ifp = NULL; sport = 0; dport = 0; dst = mapdst.s_addr; sflags = flags & NAT_TCPUDPICMP; switch (p) { case IPPROTO_TCP : case IPPROTO_UDP : sport = htons(fin->fin_data[0]); dport = htons(fin->fin_data[1]); break; case IPPROTO_ICMP : if (flags & IPN_ICMPERR) sport = fin->fin_data[1]; else dport = fin->fin_data[1]; break; default : break; } if ((flags & SI_WILDP) != 0) goto find_in_wild_ports; hv = NAT_HASH_FN(dst, dport, 0xffffffff); hv = NAT_HASH_FN(src.s_addr, hv + sport, ipf_nattable_sz); nat = nat_table[1][hv]; for (; nat; nat = nat->nat_hnext[1]) { if (nat->nat_ifps[0] != NULL) { if ((ifp != NULL) && (ifp != nat->nat_ifps[0])) continue; } else if (ifp != NULL) nat->nat_ifps[0] = ifp; nflags = nat->nat_flags; if (nat->nat_oip.s_addr == src.s_addr && nat->nat_outip.s_addr == dst && (((p == 0) && (sflags == (nat->nat_flags & IPN_TCPUDPICMP))) || (p == nat->nat_p))) { switch (p) { #if 0 case IPPROTO_GRE : if (nat->nat_call[1] != fin->fin_data[0]) continue; break; #endif case IPPROTO_ICMP : if ((flags & IPN_ICMPERR) != 0) { if (nat->nat_outport != sport) continue; } else { if (nat->nat_outport != dport) continue; } break; case IPPROTO_TCP : case IPPROTO_UDP : if (nat->nat_oport != sport) continue; if (nat->nat_outport != dport) continue; break; default : break; } ipn = nat->nat_ptr; if ((ipn != NULL) && (nat->nat_aps != NULL)) if (appr_match(fin, nat) != 0) continue; return nat; } } /* * So if we didn't find it but there are wildcard members in the hash * table, go back and look for them. We do this search and update here * because it is modifying the NAT table and we want to do this only * for the first packet that matches. The exception, of course, is * for "dummy" (FI_IGNORE) lookups. */ find_in_wild_ports: if (!(flags & NAT_TCPUDP) || !(flags & NAT_SEARCH)) return NULL; if (nat_stats.ns_wilds == 0) return NULL; RWLOCK_EXIT(&ipf_nat); hv = NAT_HASH_FN(dst, 0, 0xffffffff); hv = NAT_HASH_FN(src.s_addr, hv, ipf_nattable_sz); WRITE_ENTER(&ipf_nat); nat = nat_table[1][hv]; for (; nat; nat = nat->nat_hnext[1]) { if (nat->nat_ifps[0] != NULL) { if ((ifp != NULL) && (ifp != nat->nat_ifps[0])) continue; } else if (ifp != NULL) nat->nat_ifps[0] = ifp; if (nat->nat_p != fin->fin_p) continue; if (nat->nat_oip.s_addr != src.s_addr || nat->nat_outip.s_addr != dst) continue; nflags = nat->nat_flags; if (!(nflags & (NAT_TCPUDP|SI_WILDP))) continue; if (nat_wildok(nat, (int)sport, (int)dport, nflags, NAT_INBOUND) == 1) { if ((fin->fin_flx & FI_IGNORE) != 0) break; if ((nflags & SI_CLONE) != 0) { nat = fr_natclone(fin, nat); if (nat == NULL) break; } else { MUTEX_ENTER(&ipf_nat_new); nat_stats.ns_wilds--; MUTEX_EXIT(&ipf_nat_new); } nat->nat_oport = sport; nat->nat_outport = dport; nat->nat_flags &= ~(SI_W_DPORT|SI_W_SPORT); nat_tabmove(nat); break; } } MUTEX_DOWNGRADE(&ipf_nat); return nat; } /* ------------------------------------------------------------------------ */ /* Function: nat_tabmove */ /* Returns: Nil */ /* Parameters: nat(I) - pointer to NAT structure */ /* Write Lock: ipf_nat */ /* */ /* This function is only called for TCP/UDP NAT table entries where the */ /* original was placed in the table without hashing on the ports and we now */ /* want to include hashing on port numbers. */ /* ------------------------------------------------------------------------ */ static void nat_tabmove(nat) nat_t *nat; { nat_t **natp; u_int hv; if (nat->nat_flags & SI_CLONE) return; /* * Remove the NAT entry from the old location */ if (nat->nat_hnext[0]) nat->nat_hnext[0]->nat_phnext[0] = nat->nat_phnext[0]; *nat->nat_phnext[0] = nat->nat_hnext[0]; nat_stats.ns_bucketlen[0][nat->nat_hv[0]]--; if (nat->nat_hnext[1]) nat->nat_hnext[1]->nat_phnext[1] = nat->nat_phnext[1]; *nat->nat_phnext[1] = nat->nat_hnext[1]; nat_stats.ns_bucketlen[1][nat->nat_hv[1]]--; /* * Add into the NAT table in the new position */ hv = NAT_HASH_FN(nat->nat_inip.s_addr, nat->nat_inport, 0xffffffff); hv = NAT_HASH_FN(nat->nat_oip.s_addr, hv + nat->nat_oport, ipf_nattable_sz); nat->nat_hv[0] = hv; natp = &nat_table[0][hv]; if (*natp) (*natp)->nat_phnext[0] = &nat->nat_hnext[0]; nat->nat_phnext[0] = natp; nat->nat_hnext[0] = *natp; *natp = nat; nat_stats.ns_bucketlen[0][hv]++; hv = NAT_HASH_FN(nat->nat_outip.s_addr, nat->nat_outport, 0xffffffff); hv = NAT_HASH_FN(nat->nat_oip.s_addr, hv + nat->nat_oport, ipf_nattable_sz); nat->nat_hv[1] = hv; natp = &nat_table[1][hv]; if (*natp) (*natp)->nat_phnext[1] = &nat->nat_hnext[1]; nat->nat_phnext[1] = natp; nat->nat_hnext[1] = *natp; *natp = nat; nat_stats.ns_bucketlen[1][hv]++; } /* ------------------------------------------------------------------------ */ /* Function: nat_outlookup */ /* Returns: nat_t* - NULL == no match, */ /* else pointer to matching NAT entry */ /* Parameters: fin(I) - pointer to packet information */ /* flags(I) - NAT flags for this packet */ /* p(I) - protocol for this packet */ /* src(I) - source IP address */ /* dst(I) - destination IP address */ /* rw(I) - 1 == write lock on ipf_nat held, 0 == read lock. */ /* */ /* Lookup a nat entry based on the source 'real' ip address/port and */ /* destination address/port. We use this lookup when sending a packet out, */ /* we're looking for a table entry, based on the source address. */ /* */ /* NOTE: THE PACKET BEING CHECKED (IF FOUND) HAS A MAPPING ALREADY. */ /* */ /* NOTE: IT IS ASSUMED THAT ipf_nat IS ONLY HELD WITH A READ LOCK WHEN */ /* THIS FUNCTION IS CALLED WITH NAT_SEARCH SET IN nflags. */ /* */ /* flags -> relevant are IPN_UDP/IPN_TCP/IPN_ICMPQUERY that indicate if */ /* the packet is of said protocol */ /* ------------------------------------------------------------------------ */ nat_t *nat_outlookup(fin, flags, p, src, dst) fr_info_t *fin; u_int flags, p; struct in_addr src , dst; { u_short sport, dport; u_int sflags; ipnat_t *ipn; u_32_t srcip; nat_t *nat; int nflags; void *ifp; u_int hv; frentry_t *fr; fr = fin->fin_fr; if ((fr != NULL) && !(fr->fr_flags & FR_DUP) && fr->fr_tif.fd_ifp && fr->fr_tif.fd_ifp != (void *)-1) ifp = fr->fr_tif.fd_ifp; else ifp = fin->fin_ifp; srcip = src.s_addr; sflags = flags & IPN_TCPUDPICMP; sport = 0; dport = 0; switch (p) { case IPPROTO_TCP : case IPPROTO_UDP : sport = htons(fin->fin_data[0]); dport = htons(fin->fin_data[1]); break; case IPPROTO_ICMP : if (flags & IPN_ICMPERR) sport = fin->fin_data[1]; else dport = fin->fin_data[1]; break; default : break; } if ((flags & SI_WILDP) != 0) goto find_out_wild_ports; hv = NAT_HASH_FN(srcip, sport, 0xffffffff); hv = NAT_HASH_FN(dst.s_addr, hv + dport, ipf_nattable_sz); nat = nat_table[0][hv]; for (; nat; nat = nat->nat_hnext[0]) { if (nat->nat_ifps[1] != NULL) { if ((ifp != NULL) && (ifp != nat->nat_ifps[1])) continue; } else if (ifp != NULL) nat->nat_ifps[1] = ifp; nflags = nat->nat_flags; if (nat->nat_inip.s_addr == srcip && nat->nat_oip.s_addr == dst.s_addr && (((p == 0) && (sflags == (nflags & NAT_TCPUDPICMP))) || (p == nat->nat_p))) { switch (p) { #if 0 case IPPROTO_GRE : if (nat->nat_call[1] != fin->fin_data[0]) continue; break; #endif case IPPROTO_TCP : case IPPROTO_UDP : if (nat->nat_oport != dport) continue; if (nat->nat_inport != sport) continue; break; default : break; } ipn = nat->nat_ptr; if ((ipn != NULL) && (nat->nat_aps != NULL)) if (appr_match(fin, nat) != 0) continue; return nat; } } /* * So if we didn't find it but there are wildcard members in the hash * table, go back and look for them. We do this search and update here * because it is modifying the NAT table and we want to do this only * for the first packet that matches. The exception, of course, is * for "dummy" (FI_IGNORE) lookups. */ find_out_wild_ports: if (!(flags & NAT_TCPUDP) || !(flags & NAT_SEARCH)) return NULL; if (nat_stats.ns_wilds == 0) return NULL; RWLOCK_EXIT(&ipf_nat); hv = NAT_HASH_FN(srcip, 0, 0xffffffff); hv = NAT_HASH_FN(dst.s_addr, hv, ipf_nattable_sz); WRITE_ENTER(&ipf_nat); nat = nat_table[0][hv]; for (; nat; nat = nat->nat_hnext[0]) { if (nat->nat_ifps[1] != NULL) { if ((ifp != NULL) && (ifp != nat->nat_ifps[1])) continue; } else if (ifp != NULL) nat->nat_ifps[1] = ifp; if (nat->nat_p != fin->fin_p) continue; if ((nat->nat_inip.s_addr != srcip) || (nat->nat_oip.s_addr != dst.s_addr)) continue; nflags = nat->nat_flags; if (!(nflags & (NAT_TCPUDP|SI_WILDP))) continue; if (nat_wildok(nat, (int)sport, (int)dport, nflags, NAT_OUTBOUND) == 1) { if ((fin->fin_flx & FI_IGNORE) != 0) break; if ((nflags & SI_CLONE) != 0) { nat = fr_natclone(fin, nat); if (nat == NULL) break; } else { MUTEX_ENTER(&ipf_nat_new); nat_stats.ns_wilds--; MUTEX_EXIT(&ipf_nat_new); } nat->nat_inport = sport; nat->nat_oport = dport; if (nat->nat_outport == 0) nat->nat_outport = sport; nat->nat_flags &= ~(SI_W_DPORT|SI_W_SPORT); nat_tabmove(nat); break; } } MUTEX_DOWNGRADE(&ipf_nat); return nat; } /* ------------------------------------------------------------------------ */ /* Function: nat_lookupredir */ /* Returns: nat_t* - NULL == no match, */ /* else pointer to matching NAT entry */ /* Parameters: np(I) - pointer to description of packet to find NAT table */ /* entry for. */ /* */ /* Lookup the NAT tables to search for a matching redirect */ /* ------------------------------------------------------------------------ */ nat_t *nat_lookupredir(np) natlookup_t *np; { fr_info_t fi; nat_t *nat; bzero((char *)&fi, sizeof(fi)); if (np->nl_flags & IPN_IN) { fi.fin_data[0] = ntohs(np->nl_realport); fi.fin_data[1] = ntohs(np->nl_outport); } else { fi.fin_data[0] = ntohs(np->nl_inport); fi.fin_data[1] = ntohs(np->nl_outport); } if (np->nl_flags & IPN_TCP) fi.fin_p = IPPROTO_TCP; else if (np->nl_flags & IPN_UDP) fi.fin_p = IPPROTO_UDP; else if (np->nl_flags & (IPN_ICMPERR|IPN_ICMPQUERY)) fi.fin_p = IPPROTO_ICMP; /* * We can do two sorts of lookups: * - IPN_IN: we have the `real' and `out' address, look for `in'. * - default: we have the `in' and `out' address, look for `real'. */ if (np->nl_flags & IPN_IN) { if ((nat = nat_inlookup(&fi, np->nl_flags, fi.fin_p, np->nl_realip, np->nl_outip))) { np->nl_inip = nat->nat_inip; np->nl_inport = nat->nat_inport; } } else { /* * If nl_inip is non null, this is a lookup based on the real * ip address. Else, we use the fake. */ if ((nat = nat_outlookup(&fi, np->nl_flags, fi.fin_p, np->nl_inip, np->nl_outip))) { if ((np->nl_flags & IPN_FINDFORWARD) != 0) { fr_info_t fin; bzero((char *)&fin, sizeof(fin)); fin.fin_p = nat->nat_p; fin.fin_data[0] = ntohs(nat->nat_outport); fin.fin_data[1] = ntohs(nat->nat_oport); if (nat_inlookup(&fin, np->nl_flags, fin.fin_p, nat->nat_outip, nat->nat_oip) != NULL) { np->nl_flags &= ~IPN_FINDFORWARD; } } np->nl_realip = nat->nat_outip; np->nl_realport = nat->nat_outport; } } return nat; } /* ------------------------------------------------------------------------ */ /* Function: nat_match */ /* Returns: int - 0 == no match, 1 == match */ /* Parameters: fin(I) - pointer to packet information */ /* np(I) - pointer to NAT rule */ /* */ /* Pull the matching of a packet against a NAT rule out of that complex */ /* loop inside fr_checknatin() and lay it out properly in its own function. */ /* ------------------------------------------------------------------------ */ static int nat_match(fin, np) fr_info_t *fin; ipnat_t *np; { frtuc_t *ft; if (fin->fin_v != 4) return 0; if (np->in_p && fin->fin_p != np->in_p) return 0; if (fin->fin_out) { if (!(np->in_redir & (NAT_MAP|NAT_MAPBLK))) return 0; if (((fin->fin_fi.fi_saddr & np->in_inmsk) != np->in_inip) ^ ((np->in_flags & IPN_NOTSRC) != 0)) return 0; if (((fin->fin_fi.fi_daddr & np->in_srcmsk) != np->in_srcip) ^ ((np->in_flags & IPN_NOTDST) != 0)) return 0; } else { if (!(np->in_redir & NAT_REDIRECT)) return 0; if (((fin->fin_fi.fi_saddr & np->in_srcmsk) != np->in_srcip) ^ ((np->in_flags & IPN_NOTSRC) != 0)) return 0; if (((fin->fin_fi.fi_daddr & np->in_outmsk) != np->in_outip) ^ ((np->in_flags & IPN_NOTDST) != 0)) return 0; } ft = &np->in_tuc; if (!(fin->fin_flx & FI_TCPUDP) || (fin->fin_flx & (FI_SHORT|FI_FRAGBODY))) { if (ft->ftu_scmp || ft->ftu_dcmp) return 0; return 1; } return fr_tcpudpchk(fin, ft); } /* ------------------------------------------------------------------------ */ /* Function: nat_update */ /* Returns: Nil */ /* Parameters: nat(I) - pointer to NAT structure */ /* np(I) - pointer to NAT rule */ /* */ /* Updates the lifetime of a NAT table entry for non-TCP packets. Must be */ /* called with fin_rev updated - i.e. after calling nat_proto(). */ /* ------------------------------------------------------------------------ */ void nat_update(fin, nat, np) fr_info_t *fin; nat_t *nat; ipnat_t *np; { ipftq_t *ifq, *ifq2; ipftqent_t *tqe; MUTEX_ENTER(&nat->nat_lock); tqe = &nat->nat_tqe; ifq = tqe->tqe_ifq; /* * We allow over-riding of NAT timeouts from NAT rules, even for * TCP, however, if it is TCP and there is no rule timeout set, * then do not update the timeout here. */ if (np != NULL) ifq2 = np->in_tqehead[fin->fin_rev]; else ifq2 = NULL; if (nat->nat_p == IPPROTO_TCP && ifq2 == NULL) { (void) fr_tcp_age(&nat->nat_tqe, fin, nat_tqb, 0); } else { if (ifq2 == NULL) { if (nat->nat_p == IPPROTO_UDP) ifq2 = &nat_udptq; else if (nat->nat_p == IPPROTO_ICMP) ifq2 = &nat_icmptq; else ifq2 = &nat_iptq; } fr_movequeue(tqe, ifq, ifq2); } MUTEX_EXIT(&nat->nat_lock); } /* ------------------------------------------------------------------------ */ /* Function: fr_checknatout */ /* Returns: int - -1 == packet failed NAT checks so block it, */ /* 0 == no packet translation occurred, */ /* 1 == packet was successfully translated. */ /* Parameters: fin(I) - pointer to packet information */ /* passp(I) - pointer to filtering result flags */ /* */ /* Check to see if an outcoming packet should be changed. ICMP packets are */ /* first checked to see if they match an existing entry (if an error), */ /* otherwise a search of the current NAT table is made. If neither results */ /* in a match then a search for a matching NAT rule is made. Create a new */ /* NAT entry if a we matched a NAT rule. Lastly, actually change the */ /* packet header(s) as required. */ /* ------------------------------------------------------------------------ */ int fr_checknatout(fin, passp) fr_info_t *fin; u_32_t *passp; { struct ifnet *ifp, *sifp; icmphdr_t *icmp = NULL; tcphdr_t *tcp = NULL; int rval, natfailed; ipnat_t *np = NULL; u_int nflags = 0; u_32_t ipa, iph; int natadd = 1; frentry_t *fr; nat_t *nat; if (nat_stats.ns_rules == 0 || fr_nat_lock != 0) return 0; natfailed = 0; fr = fin->fin_fr; sifp = fin->fin_ifp; if ((fr != NULL) && !(fr->fr_flags & FR_DUP) && fr->fr_tif.fd_ifp && fr->fr_tif.fd_ifp != (void *)-1) fin->fin_ifp = fr->fr_tif.fd_ifp; ifp = fin->fin_ifp; if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { switch (fin->fin_p) { case IPPROTO_TCP : nflags = IPN_TCP; break; case IPPROTO_UDP : nflags = IPN_UDP; break; case IPPROTO_ICMP : icmp = fin->fin_dp; /* * This is an incoming packet, so the destination is * the icmp_id and the source port equals 0 */ if (nat_icmpquerytype4(icmp->icmp_type)) nflags = IPN_ICMPQUERY; break; default : break; } if ((nflags & IPN_TCPUDP)) tcp = fin->fin_dp; } ipa = fin->fin_saddr; READ_ENTER(&ipf_nat); if ((fin->fin_p == IPPROTO_ICMP) && !(nflags & IPN_ICMPQUERY) && (nat = nat_icmperror(fin, &nflags, NAT_OUTBOUND))) /*EMPTY*/; else if ((fin->fin_flx & FI_FRAG) && (nat = fr_nat_knownfrag(fin))) natadd = 0; else if ((nat = nat_outlookup(fin, nflags|NAT_SEARCH, (u_int)fin->fin_p, fin->fin_src, fin->fin_dst))) { nflags = nat->nat_flags; } else { u_32_t hv, msk, nmsk; /* * If there is no current entry in the nat table for this IP#, * create one for it (if there is a matching rule). */ RWLOCK_EXIT(&ipf_nat); msk = 0xffffffff; nmsk = nat_masks; WRITE_ENTER(&ipf_nat); maskloop: iph = ipa & htonl(msk); hv = NAT_HASH_FN(iph, 0, ipf_natrules_sz); for (np = nat_rules[hv]; np; np = np->in_mnext) { if ((np->in_ifps[1] && (np->in_ifps[1] != ifp))) continue; if (np->in_v != fin->fin_v) continue; if (np->in_p && (np->in_p != fin->fin_p)) continue; if ((np->in_flags & IPN_RF) && !(np->in_flags & nflags)) continue; if (np->in_flags & IPN_FILTER) { if (!nat_match(fin, np)) continue; } else if ((ipa & np->in_inmsk) != np->in_inip) continue; if ((fr != NULL) && !fr_matchtag(&np->in_tag, &fr->fr_nattag)) continue; if (*np->in_plabel != '\0') { if (((np->in_flags & IPN_FILTER) == 0) && (np->in_dport != tcp->th_dport)) continue; if (appr_ok(fin, tcp, np) == 0) continue; } if ((nat = nat_new(fin, np, NULL, nflags, NAT_OUTBOUND))) { np->in_hits++; break; } else natfailed = -1; } if ((np == NULL) && (nmsk != 0)) { while (nmsk) { msk <<= 1; if (nmsk & 0x80000000) break; nmsk <<= 1; } if (nmsk != 0) { nmsk <<= 1; goto maskloop; } } MUTEX_DOWNGRADE(&ipf_nat); } if (nat != NULL) { rval = fr_natout(fin, nat, natadd, nflags); if (rval == 1) { MUTEX_ENTER(&nat->nat_lock); nat->nat_ref++; MUTEX_EXIT(&nat->nat_lock); fin->fin_nat = nat; } } else rval = natfailed; RWLOCK_EXIT(&ipf_nat); if (rval == -1) { if (passp != NULL) *passp = FR_BLOCK; fin->fin_flx |= FI_BADNAT; } fin->fin_ifp = sifp; return rval; } /* ------------------------------------------------------------------------ */ /* Function: fr_natout */ /* Returns: int - -1 == packet failed NAT checks so block it, */ /* 1 == packet was successfully translated. */ /* Parameters: fin(I) - pointer to packet information */ /* nat(I) - pointer to NAT structure */ /* natadd(I) - flag indicating if it is safe to add frag cache */ /* nflags(I) - NAT flags set for this packet */ /* */ /* Translate a packet coming "out" on an interface. */ /* ------------------------------------------------------------------------ */ int fr_natout(fin, nat, natadd, nflags) fr_info_t *fin; nat_t *nat; int natadd; u_32_t nflags; { icmphdr_t *icmp; u_short *csump; tcphdr_t *tcp; ipnat_t *np; int i; tcp = NULL; icmp = NULL; csump = NULL; np = nat->nat_ptr; if ((natadd != 0) && (fin->fin_flx & FI_FRAG) && (np != NULL)) (void) fr_nat_newfrag(fin, 0, nat); MUTEX_ENTER(&nat->nat_lock); nat->nat_bytes[1] += fin->fin_plen; nat->nat_pkts[1]++; MUTEX_EXIT(&nat->nat_lock); /* * Fix up checksums, not by recalculating them, but * simply computing adjustments. * This is only done for STREAMS based IP implementations where the * checksum has already been calculated by IP. In all other cases, * IPFilter is called before the checksum needs calculating so there * is no call to modify whatever is in the header now. */ if (fin->fin_v == 4) { if (nflags == IPN_ICMPERR) { u_32_t s1, s2, sumd; s1 = LONG_SUM(ntohl(fin->fin_saddr)); s2 = LONG_SUM(ntohl(nat->nat_outip.s_addr)); CALC_SUMD(s1, s2, sumd); fix_outcksum(fin, &fin->fin_ip->ip_sum, sumd); } #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ defined(linux) || defined(BRIDGE_IPF) else { /* * Strictly speaking, this isn't necessary on BSD * kernels because they do checksum calculation after * this code has run BUT if ipfilter is being used * to do NAT as a bridge, that code doesn't exist. */ if (nat->nat_dir == NAT_OUTBOUND) fix_outcksum(fin, &fin->fin_ip->ip_sum, nat->nat_ipsumd); else fix_incksum(fin, &fin->fin_ip->ip_sum, nat->nat_ipsumd); } #endif } if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { if ((nat->nat_outport != 0) && (nflags & IPN_TCPUDP)) { tcp = fin->fin_dp; tcp->th_sport = nat->nat_outport; fin->fin_data[0] = ntohs(nat->nat_outport); } if ((nat->nat_outport != 0) && (nflags & IPN_ICMPQUERY)) { icmp = fin->fin_dp; icmp->icmp_id = nat->nat_outport; } csump = nat_proto(fin, nat, nflags); } fin->fin_ip->ip_src = nat->nat_outip; nat_update(fin, nat, np); /* * The above comments do not hold for layer 4 (or higher) checksums... */ if (csump != NULL) { if (nat->nat_dir == NAT_OUTBOUND) fix_outcksum(fin, csump, nat->nat_sumd[1]); else fix_incksum(fin, csump, nat->nat_sumd[1]); } #ifdef IPFILTER_SYNC ipfsync_update(SMC_NAT, fin, nat->nat_sync); #endif /* ------------------------------------------------------------- */ /* A few quick notes: */ /* Following are test conditions prior to calling the */ /* appr_check routine. */ /* */ /* A NULL tcp indicates a non TCP/UDP packet. When dealing */ /* with a redirect rule, we attempt to match the packet's */ /* source port against in_dport, otherwise we'd compare the */ /* packet's destination. */ /* ------------------------------------------------------------- */ if ((np != NULL) && (np->in_apr != NULL)) { i = appr_check(fin, nat); if (i == 0) i = 1; } else i = 1; ATOMIC_INCL(nat_stats.ns_mapped[1]); fin->fin_flx |= FI_NATED; return i; } /* ------------------------------------------------------------------------ */ /* Function: fr_checknatin */ /* Returns: int - -1 == packet failed NAT checks so block it, */ /* 0 == no packet translation occurred, */ /* 1 == packet was successfully translated. */ /* Parameters: fin(I) - pointer to packet information */ /* passp(I) - pointer to filtering result flags */ /* */ /* Check to see if an incoming packet should be changed. ICMP packets are */ /* first checked to see if they match an existing entry (if an error), */ /* otherwise a search of the current NAT table is made. If neither results */ /* in a match then a search for a matching NAT rule is made. Create a new */ /* NAT entry if a we matched a NAT rule. Lastly, actually change the */ /* packet header(s) as required. */ /* ------------------------------------------------------------------------ */ int fr_checknatin(fin, passp) fr_info_t *fin; u_32_t *passp; { u_int nflags, natadd; int rval, natfailed; struct ifnet *ifp; struct in_addr in; icmphdr_t *icmp; tcphdr_t *tcp; u_short dport; ipnat_t *np; nat_t *nat; u_32_t iph; if (nat_stats.ns_rules == 0 || fr_nat_lock != 0) return 0; tcp = NULL; icmp = NULL; dport = 0; natadd = 1; nflags = 0; natfailed = 0; ifp = fin->fin_ifp; if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { switch (fin->fin_p) { case IPPROTO_TCP : nflags = IPN_TCP; break; case IPPROTO_UDP : nflags = IPN_UDP; break; case IPPROTO_ICMP : icmp = fin->fin_dp; /* * This is an incoming packet, so the destination is * the icmp_id and the source port equals 0 */ if (nat_icmpquerytype4(icmp->icmp_type)) { nflags = IPN_ICMPQUERY; dport = icmp->icmp_id; } break; default : break; } if ((nflags & IPN_TCPUDP)) { tcp = fin->fin_dp; dport = tcp->th_dport; } } in = fin->fin_dst; READ_ENTER(&ipf_nat); if ((fin->fin_p == IPPROTO_ICMP) && !(nflags & IPN_ICMPQUERY) && (nat = nat_icmperror(fin, &nflags, NAT_INBOUND))) /*EMPTY*/; else if ((fin->fin_flx & FI_FRAG) && (nat = fr_nat_knownfrag(fin))) natadd = 0; else if ((nat = nat_inlookup(fin, nflags|NAT_SEARCH, (u_int)fin->fin_p, fin->fin_src, in))) { nflags = nat->nat_flags; } else { u_32_t hv, msk, rmsk; RWLOCK_EXIT(&ipf_nat); rmsk = rdr_masks; msk = 0xffffffff; WRITE_ENTER(&ipf_nat); /* * If there is no current entry in the nat table for this IP#, * create one for it (if there is a matching rule). */ maskloop: iph = in.s_addr & htonl(msk); hv = NAT_HASH_FN(iph, 0, ipf_rdrrules_sz); for (np = rdr_rules[hv]; np; np = np->in_rnext) { if (np->in_ifps[0] && (np->in_ifps[0] != ifp)) continue; if (np->in_v != fin->fin_v) continue; if (np->in_p && (np->in_p != fin->fin_p)) continue; if ((np->in_flags & IPN_RF) && !(np->in_flags & nflags)) continue; if (np->in_flags & IPN_FILTER) { if (!nat_match(fin, np)) continue; } else { if ((in.s_addr & np->in_outmsk) != np->in_outip) continue; if (np->in_pmin && ((ntohs(np->in_pmax) < ntohs(dport)) || (ntohs(dport) < ntohs(np->in_pmin)))) continue; } if (*np->in_plabel != '\0') { if (!appr_ok(fin, tcp, np)) { continue; } } nat = nat_new(fin, np, NULL, nflags, NAT_INBOUND); if (nat != NULL) { np->in_hits++; break; } else natfailed = -1; } if ((np == NULL) && (rmsk != 0)) { while (rmsk) { msk <<= 1; if (rmsk & 0x80000000) break; rmsk <<= 1; } if (rmsk != 0) { rmsk <<= 1; goto maskloop; } } MUTEX_DOWNGRADE(&ipf_nat); } if (nat != NULL) { rval = fr_natin(fin, nat, natadd, nflags); if (rval == 1) { MUTEX_ENTER(&nat->nat_lock); nat->nat_ref++; MUTEX_EXIT(&nat->nat_lock); fin->fin_nat = nat; fin->fin_state = nat->nat_state; } } else rval = natfailed; RWLOCK_EXIT(&ipf_nat); if (rval == -1) { if (passp != NULL) *passp = FR_BLOCK; fin->fin_flx |= FI_BADNAT; } return rval; } /* ------------------------------------------------------------------------ */ /* Function: fr_natin */ /* Returns: int - -1 == packet failed NAT checks so block it, */ /* 1 == packet was successfully translated. */ /* Parameters: fin(I) - pointer to packet information */ /* nat(I) - pointer to NAT structure */ /* natadd(I) - flag indicating if it is safe to add frag cache */ /* nflags(I) - NAT flags set for this packet */ /* Locks Held: ipf_nat (READ) */ /* */ /* Translate a packet coming "in" on an interface. */ /* ------------------------------------------------------------------------ */ int fr_natin(fin, nat, natadd, nflags) fr_info_t *fin; nat_t *nat; int natadd; u_32_t nflags; { icmphdr_t *icmp; u_short *csump; tcphdr_t *tcp; ipnat_t *np; int i; tcp = NULL; csump = NULL; np = nat->nat_ptr; fin->fin_fr = nat->nat_fr; if (np != NULL) { if ((natadd != 0) && (fin->fin_flx & FI_FRAG)) (void) fr_nat_newfrag(fin, 0, nat); /* ------------------------------------------------------------- */ /* A few quick notes: */ /* Following are test conditions prior to calling the */ /* appr_check routine. */ /* */ /* A NULL tcp indicates a non TCP/UDP packet. When dealing */ /* with a map rule, we attempt to match the packet's */ /* source port against in_dport, otherwise we'd compare the */ /* packet's destination. */ /* ------------------------------------------------------------- */ if (np->in_apr != NULL) { i = appr_check(fin, nat); if (i == -1) { return -1; } } } #ifdef IPFILTER_SYNC ipfsync_update(SMC_NAT, fin, nat->nat_sync); #endif MUTEX_ENTER(&nat->nat_lock); nat->nat_bytes[0] += fin->fin_plen; nat->nat_pkts[0]++; MUTEX_EXIT(&nat->nat_lock); fin->fin_ip->ip_dst = nat->nat_inip; fin->fin_fi.fi_daddr = nat->nat_inip.s_addr; if (nflags & IPN_TCPUDP) tcp = fin->fin_dp; /* * Fix up checksums, not by recalculating them, but * simply computing adjustments. * Why only do this for some platforms on inbound packets ? * Because for those that it is done, IP processing is yet to happen * and so the IPv4 header checksum has not yet been evaluated. * Perhaps it should always be done for the benefit of things like * fast forwarding (so that it doesn't need to be recomputed) but with * header checksum offloading, perhaps it is a moot point. */ #if !defined(_KERNEL) || defined(MENTAT) || defined(__sgi) || \ defined(__osf__) || defined(linux) if (nat->nat_dir == NAT_OUTBOUND) fix_incksum(fin, &fin->fin_ip->ip_sum, nat->nat_ipsumd); else fix_outcksum(fin, &fin->fin_ip->ip_sum, nat->nat_ipsumd); #endif if (!(fin->fin_flx & FI_SHORT) && (fin->fin_off == 0)) { if ((nat->nat_inport != 0) && (nflags & IPN_TCPUDP)) { tcp->th_dport = nat->nat_inport; fin->fin_data[1] = ntohs(nat->nat_inport); } if ((nat->nat_inport != 0) && (nflags & IPN_ICMPQUERY)) { icmp = fin->fin_dp; icmp->icmp_id = nat->nat_inport; } csump = nat_proto(fin, nat, nflags); } nat_update(fin, nat, np); /* * The above comments do not hold for layer 4 (or higher) checksums... */ if (csump != NULL) { if (nat->nat_dir == NAT_OUTBOUND) fix_incksum(fin, csump, nat->nat_sumd[0]); else fix_outcksum(fin, csump, nat->nat_sumd[0]); } ATOMIC_INCL(nat_stats.ns_mapped[0]); fin->fin_flx |= FI_NATED; if (np != NULL && np->in_tag.ipt_num[0] != 0) fin->fin_nattag = &np->in_tag; return 1; } /* ------------------------------------------------------------------------ */ /* Function: nat_proto */ /* Returns: u_short* - pointer to transport header checksum to update, */ /* NULL if the transport protocol is not recognised */ /* as needing a checksum update. */ /* Parameters: fin(I) - pointer to packet information */ /* nat(I) - pointer to NAT structure */ /* nflags(I) - NAT flags set for this packet */ /* */ /* Return the pointer to the checksum field for each protocol so understood.*/ /* If support for making other changes to a protocol header is required, */ /* that is not strictly 'address' translation, such as clamping the MSS in */ /* TCP down to a specific value, then do it from here. */ /* ------------------------------------------------------------------------ */ u_short *nat_proto(fin, nat, nflags) fr_info_t *fin; nat_t *nat; u_int nflags; { icmphdr_t *icmp; u_short *csump; tcphdr_t *tcp; udphdr_t *udp; csump = NULL; if (fin->fin_out == 0) { fin->fin_rev = (nat->nat_dir == NAT_OUTBOUND); } else { fin->fin_rev = (nat->nat_dir == NAT_INBOUND); } switch (fin->fin_p) { case IPPROTO_TCP : tcp = fin->fin_dp; csump = &tcp->th_sum; /* * Do a MSS CLAMPING on a SYN packet, * only deal IPv4 for now. */ if ((nat->nat_mssclamp != 0) && (tcp->th_flags & TH_SYN) != 0) nat_mssclamp(tcp, nat->nat_mssclamp, fin, csump); break; case IPPROTO_UDP : udp = fin->fin_dp; if (udp->uh_sum) csump = &udp->uh_sum; break; case IPPROTO_ICMP : icmp = fin->fin_dp; if ((nflags & IPN_ICMPQUERY) != 0) { if (icmp->icmp_cksum != 0) csump = &icmp->icmp_cksum; } break; } return csump; } /* ------------------------------------------------------------------------ */ /* Function: fr_natunload */ /* Returns: Nil */ /* Parameters: Nil */ /* */ /* Free all memory used by NAT structures allocated at runtime. */ /* ------------------------------------------------------------------------ */ void fr_natunload() { ipftq_t *ifq, *ifqnext; (void) nat_clearlist(); (void) nat_flushtable(); /* * Proxy timeout queues are not cleaned here because although they * exist on the NAT list, appr_unload is called after fr_natunload * and the proxies actually are responsible for them being created. * Should the proxy timeouts have their own list? There's no real * justification as this is the only complication. */ for (ifq = nat_utqe; ifq != NULL; ifq = ifqnext) { ifqnext = ifq->ifq_next; if (((ifq->ifq_flags & IFQF_PROXY) == 0) && (fr_deletetimeoutqueue(ifq) == 0)) fr_freetimeoutqueue(ifq); } if (nat_table[0] != NULL) { KFREES(nat_table[0], sizeof(nat_t *) * ipf_nattable_sz); nat_table[0] = NULL; } if (nat_table[1] != NULL) { KFREES(nat_table[1], sizeof(nat_t *) * ipf_nattable_sz); nat_table[1] = NULL; } if (nat_rules != NULL) { KFREES(nat_rules, sizeof(ipnat_t *) * ipf_natrules_sz); nat_rules = NULL; } if (rdr_rules != NULL) { KFREES(rdr_rules, sizeof(ipnat_t *) * ipf_rdrrules_sz); rdr_rules = NULL; } if (maptable != NULL) { KFREES(maptable, sizeof(hostmap_t *) * ipf_hostmap_sz); maptable = NULL; } if (nat_stats.ns_bucketlen[0] != NULL) { KFREES(nat_stats.ns_bucketlen[0], sizeof(u_long *) * ipf_nattable_sz); nat_stats.ns_bucketlen[0] = NULL; } if (nat_stats.ns_bucketlen[1] != NULL) { KFREES(nat_stats.ns_bucketlen[1], sizeof(u_long *) * ipf_nattable_sz); nat_stats.ns_bucketlen[1] = NULL; } if (fr_nat_maxbucket_reset == 1) fr_nat_maxbucket = 0; if (fr_nat_init == 1) { fr_nat_init = 0; fr_sttab_destroy(nat_tqb); RW_DESTROY(&ipf_natfrag); RW_DESTROY(&ipf_nat); MUTEX_DESTROY(&ipf_nat_new); MUTEX_DESTROY(&ipf_natio); MUTEX_DESTROY(&nat_udptq.ifq_lock); MUTEX_DESTROY(&nat_icmptq.ifq_lock); MUTEX_DESTROY(&nat_iptq.ifq_lock); } } /* ------------------------------------------------------------------------ */ /* Function: fr_natexpire */ /* Returns: Nil */ /* Parameters: Nil */ /* */ /* Check all of the timeout queues for entries at the top which need to be */ /* expired. */ /* ------------------------------------------------------------------------ */ void fr_natexpire() { ipftq_t *ifq, *ifqnext; ipftqent_t *tqe, *tqn; int i; SPL_INT(s); SPL_NET(s); WRITE_ENTER(&ipf_nat); for (ifq = nat_tqb, i = 0; ifq != NULL; ifq = ifq->ifq_next) { for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); i++) { if (tqe->tqe_die > fr_ticks) break; tqn = tqe->tqe_next; nat_delete(tqe->tqe_parent, NL_EXPIRE); } } for (ifq = nat_utqe; ifq != NULL; ifq = ifqnext) { ifqnext = ifq->ifq_next; for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); i++) { if (tqe->tqe_die > fr_ticks) break; tqn = tqe->tqe_next; nat_delete(tqe->tqe_parent, NL_EXPIRE); } } for (ifq = nat_utqe; ifq != NULL; ifq = ifqnext) { ifqnext = ifq->ifq_next; if (((ifq->ifq_flags & IFQF_DELETE) != 0) && (ifq->ifq_ref == 0)) { fr_freetimeoutqueue(ifq); } } RWLOCK_EXIT(&ipf_nat); SPL_X(s); } /* ------------------------------------------------------------------------ */ /* Function: fr_natsync */ /* Returns: Nil */ /* Parameters: ifp(I) - pointer to network interface */ /* */ /* Walk through all of the currently active NAT sessions, looking for those */ /* which need to have their translated address updated. */ /* ------------------------------------------------------------------------ */ void fr_natsync(ifp) void *ifp; { u_32_t sum1, sum2, sumd; struct in_addr in; ipnat_t *n; nat_t *nat; void *ifp2; SPL_INT(s); if (fr_running <= 0) return; /* * Change IP addresses for NAT sessions for any protocol except TCP * since it will break the TCP connection anyway. The only rules * which will get changed are those which are "map ... -> 0/32", * where the rule specifies the address is taken from the interface. */ SPL_NET(s); WRITE_ENTER(&ipf_nat); if (fr_running <= 0) { RWLOCK_EXIT(&ipf_nat); return; } for (nat = nat_instances; nat; nat = nat->nat_next) { if ((nat->nat_flags & IPN_TCP) != 0) continue; n = nat->nat_ptr; if ((n == NULL) || (n->in_outip != 0) || (n->in_outmsk != 0xffffffff)) continue; if (((ifp == NULL) || (ifp == nat->nat_ifps[0]) || (ifp == nat->nat_ifps[1]))) { nat->nat_ifps[0] = GETIFP(nat->nat_ifnames[0], 4); if (nat->nat_ifnames[1][0] != '\0') { nat->nat_ifps[1] = GETIFP(nat->nat_ifnames[1], 4); } else nat->nat_ifps[1] = nat->nat_ifps[0]; ifp2 = nat->nat_ifps[0]; if (ifp2 == NULL) continue; /* * Change the map-to address to be the same as the * new one. */ sum1 = nat->nat_outip.s_addr; if (fr_ifpaddr(4, FRI_NORMAL, ifp2, &in, NULL) != -1) nat->nat_outip = in; sum2 = nat->nat_outip.s_addr; if (sum1 == sum2) continue; /* * Readjust the checksum adjustment to take into * account the new IP#. */ CALC_SUMD(sum1, sum2, sumd); /* XXX - dont change for TCP when solaris does * hardware checksumming. */ sumd += nat->nat_sumd[0]; nat->nat_sumd[0] = (sumd & 0xffff) + (sumd >> 16); nat->nat_sumd[1] = nat->nat_sumd[0]; } } for (n = nat_list; (n != NULL); n = n->in_next) { if ((ifp == NULL) || (n->in_ifps[0] == ifp)) n->in_ifps[0] = fr_resolvenic(n->in_ifnames[0], 4); if ((ifp == NULL) || (n->in_ifps[1] == ifp)) n->in_ifps[1] = fr_resolvenic(n->in_ifnames[1], 4); } RWLOCK_EXIT(&ipf_nat); SPL_X(s); } /* ------------------------------------------------------------------------ */ /* Function: nat_icmpquerytype4 */ /* Returns: int - 1 == success, 0 == failure */ /* Parameters: icmptype(I) - ICMP type number */ /* */ /* Tests to see if the ICMP type number passed is a query/response type or */ /* not. */ /* ------------------------------------------------------------------------ */ static INLINE int nat_icmpquerytype4(icmptype) int icmptype; { /* * For the ICMP query NAT code, it is essential that both the query * and the reply match on the NAT rule. Because the NAT structure * does not keep track of the icmptype, and a single NAT structure * is used for all icmp types with the same src, dest and id, we * simply define the replies as queries as well. The funny thing is, * altough it seems silly to call a reply a query, this is exactly * as it is defined in the IPv4 specification */ switch (icmptype) { case ICMP_ECHOREPLY: case ICMP_ECHO: /* route aedvertisement/solliciation is currently unsupported: */ /* it would require rewriting the ICMP data section */ case ICMP_TSTAMP: case ICMP_TSTAMPREPLY: case ICMP_IREQ: case ICMP_IREQREPLY: case ICMP_MASKREQ: case ICMP_MASKREPLY: return 1; default: return 0; } } /* ------------------------------------------------------------------------ */ /* Function: nat_log */ /* Returns: Nil */ /* Parameters: nat(I) - pointer to NAT structure */ /* type(I) - type of log entry to create */ /* */ /* Creates a NAT log entry. */ /* ------------------------------------------------------------------------ */ void nat_log(nat, type) struct nat *nat; u_int type; { #ifdef IPFILTER_LOG # ifndef LARGE_NAT struct ipnat *np; int rulen; # endif struct natlog natl; void *items[1]; size_t sizes[1]; int types[1]; natl.nl_inip = nat->nat_inip; natl.nl_outip = nat->nat_outip; natl.nl_origip = nat->nat_oip; natl.nl_bytes[0] = nat->nat_bytes[0]; natl.nl_bytes[1] = nat->nat_bytes[1]; natl.nl_pkts[0] = nat->nat_pkts[0]; natl.nl_pkts[1] = nat->nat_pkts[1]; natl.nl_origport = nat->nat_oport; natl.nl_inport = nat->nat_inport; natl.nl_outport = nat->nat_outport; natl.nl_p = nat->nat_p; natl.nl_type = type; natl.nl_rule = -1; # ifndef LARGE_NAT if (nat->nat_ptr != NULL) { for (rulen = 0, np = nat_list; np; np = np->in_next, rulen++) if (np == nat->nat_ptr) { natl.nl_rule = rulen; break; } } # endif items[0] = &natl; sizes[0] = sizeof(natl); types[0] = 0; (void) ipllog(IPL_LOGNAT, NULL, items, sizes, types, 1); #endif } #if defined(__OpenBSD__) /* ------------------------------------------------------------------------ */ /* Function: nat_ifdetach */ /* Returns: Nil */ /* Parameters: ifp(I) - pointer to network interface */ /* */ /* Compatibility interface for OpenBSD to trigger the correct updating of */ /* interface references within IPFilter. */ /* ------------------------------------------------------------------------ */ void nat_ifdetach(ifp) void *ifp; { frsync(ifp); return; } #endif /* ------------------------------------------------------------------------ */ /* Function: fr_natderef */ /* Returns: Nil */ /* Parameters: isp(I) - pointer to pointer to NAT table entry */ /* */ /* Decrement the reference counter for this NAT table entry and free it if */ /* there are no more things using it. */ /* ------------------------------------------------------------------------ */ void fr_natderef(natp) nat_t **natp; { nat_t *nat; nat = *natp; *natp = NULL; WRITE_ENTER(&ipf_nat); nat->nat_ref--; if (nat->nat_ref == 0) nat_delete(nat, NL_EXPIRE); RWLOCK_EXIT(&ipf_nat); } /* ------------------------------------------------------------------------ */ /* Function: fr_natclone */ /* Returns: ipstate_t* - NULL == cloning failed, */ /* else pointer to new state structure */ /* Parameters: fin(I) - pointer to packet information */ /* is(I) - pointer to master state structure */ /* Write Lock: ipf_nat */ /* */ /* Create a "duplcate" state table entry from the master. */ /* ------------------------------------------------------------------------ */ static nat_t *fr_natclone(fin, nat) fr_info_t *fin; nat_t *nat; { frentry_t *fr; nat_t *clone; ipnat_t *np; KMALLOC(clone, nat_t *); if (clone == NULL) return NULL; bcopy((char *)nat, (char *)clone, sizeof(*clone)); MUTEX_NUKE(&clone->nat_lock); clone->nat_aps = NULL; /* * Initialize all these so that nat_delete() doesn't cause a crash. */ clone->nat_tqe.tqe_pnext = NULL; clone->nat_tqe.tqe_next = NULL; clone->nat_tqe.tqe_ifq = NULL; clone->nat_tqe.tqe_parent = clone; clone->nat_flags &= ~SI_CLONE; clone->nat_flags |= SI_CLONED; if (clone->nat_hm) clone->nat_hm->hm_ref++; if (nat_insert(clone, fin->fin_rev) == -1) { KFREE(clone); return NULL; } np = clone->nat_ptr; if (np != NULL) { if (nat_logging) nat_log(clone, (u_int)np->in_redir); np->in_use++; } fr = clone->nat_fr; if (fr != NULL) { MUTEX_ENTER(&fr->fr_lock); fr->fr_ref++; MUTEX_EXIT(&fr->fr_lock); } /* * Because the clone is created outside the normal loop of things and * TCP has special needs in terms of state, initialise the timeout * state of the new NAT from here. */ if (clone->nat_p == IPPROTO_TCP) { (void) fr_tcp_age(&clone->nat_tqe, fin, nat_tqb, clone->nat_flags); } #ifdef IPFILTER_SYNC clone->nat_sync = ipfsync_new(SMC_NAT, fin, clone); #endif if (nat_logging) nat_log(clone, NL_CLONE); return clone; } /* ------------------------------------------------------------------------ */ /* Function: nat_wildok */ /* Returns: int - 1 == packet's ports match wildcards */ /* 0 == packet's ports don't match wildcards */ /* Parameters: nat(I) - NAT entry */ /* sport(I) - source port */ /* dport(I) - destination port */ /* flags(I) - wildcard flags */ /* dir(I) - packet direction */ /* */ /* Use NAT entry and packet direction to determine which combination of */ /* wildcard flags should be used. */ /* ------------------------------------------------------------------------ */ static INLINE int nat_wildok(nat, sport, dport, flags, dir) nat_t *nat; int sport; int dport; int flags; int dir; { /* * When called by dir is set to * nat_inlookup NAT_INBOUND (0) * nat_outlookup NAT_OUTBOUND (1) * * We simply combine the packet's direction in dir with the original * "intended" direction of that NAT entry in nat->nat_dir to decide * which combination of wildcard flags to allow. */ switch ((dir << 1) | nat->nat_dir) { case 3: /* outbound packet / outbound entry */ if (((nat->nat_inport == sport) || (flags & SI_W_SPORT)) && ((nat->nat_oport == dport) || (flags & SI_W_DPORT))) return 1; break; case 2: /* outbound packet / inbound entry */ if (((nat->nat_outport == sport) || (flags & SI_W_DPORT)) && ((nat->nat_oport == dport) || (flags & SI_W_SPORT))) return 1; break; case 1: /* inbound packet / outbound entry */ if (((nat->nat_oport == sport) || (flags & SI_W_DPORT)) && ((nat->nat_outport == dport) || (flags & SI_W_SPORT))) return 1; break; case 0: /* inbound packet / inbound entry */ if (((nat->nat_oport == sport) || (flags & SI_W_SPORT)) && ((nat->nat_outport == dport) || (flags & SI_W_DPORT))) return 1; break; default: break; } return(0); } /* ------------------------------------------------------------------------ */ /* Function: nat_mssclamp */ /* Returns: Nil */ /* Parameters: tcp(I) - pointer to TCP header */ /* maxmss(I) - value to clamp the TCP MSS to */ /* fin(I) - pointer to packet information */ /* csump(I) - pointer to TCP checksum */ /* */ /* Check for MSS option and clamp it if necessary. If found and changed, */ /* then the TCP header checksum will be updated to reflect the change in */ /* the MSS. */ /* ------------------------------------------------------------------------ */ static void nat_mssclamp(tcp, maxmss, fin, csump) tcphdr_t *tcp; u_32_t maxmss; fr_info_t *fin; u_short *csump; { u_char *cp, *ep, opt; int hlen, advance; u_32_t mss, sumd; hlen = TCP_OFF(tcp) << 2; if (hlen > sizeof(*tcp)) { cp = (u_char *)tcp + sizeof(*tcp); ep = (u_char *)tcp + hlen; while (cp < ep) { opt = cp[0]; if (opt == TCPOPT_EOL) break; else if (opt == TCPOPT_NOP) { cp++; continue; } if (cp + 1 >= ep) break; advance = cp[1]; if ((cp + advance > ep) || (advance <= 0)) break; switch (opt) { case TCPOPT_MAXSEG: if (advance != 4) break; mss = cp[2] * 256 + cp[3]; if (mss > maxmss) { cp[2] = maxmss / 256; cp[3] = maxmss & 0xff; CALC_SUMD(mss, maxmss, sumd); fix_outcksum(fin, csump, sumd); } break; default: /* ignore unknown options */ break; } cp += advance; } } } /* ------------------------------------------------------------------------ */ /* Function: fr_setnatqueue */ /* Returns: Nil */ /* Parameters: nat(I)- pointer to NAT structure */ /* rev(I) - forward(0) or reverse(1) direction */ /* Locks: ipf_nat (read or write) */ /* */ /* Put the NAT entry on its default queue entry, using rev as a helped in */ /* determining which queue it should be placed on. */ /* ------------------------------------------------------------------------ */ void fr_setnatqueue(nat, rev) nat_t *nat; int rev; { ipftq_t *oifq, *nifq; if (nat->nat_ptr != NULL) nifq = nat->nat_ptr->in_tqehead[rev]; else nifq = NULL; if (nifq == NULL) { switch (nat->nat_p) { case IPPROTO_UDP : nifq = &nat_udptq; break; case IPPROTO_ICMP : nifq = &nat_icmptq; break; case IPPROTO_TCP : nifq = nat_tqb + nat->nat_tqe.tqe_state[rev]; break; default : nifq = &nat_iptq; break; } } oifq = nat->nat_tqe.tqe_ifq; /* * If it's currently on a timeout queue, move it from one queue to * another, else put it on the end of the newly determined queue. */ if (oifq != NULL) fr_movequeue(&nat->nat_tqe, oifq, nifq); else fr_queueappend(&nat->nat_tqe, nifq, nat); return; }