/* * Copyright (C) 1993-2003 by Darren Reed. * * See the IPFILTER.LICENCE file for details on licencing. * * Copyright 2009 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #if defined(KERNEL) || defined(_KERNEL) # undef KERNEL # undef _KERNEL # define KERNEL 1 # define _KERNEL 1 #endif #include #include #include #include #include #ifdef __hpux # include #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(linux) # include #endif #include #if defined(_KERNEL) # include # if !defined(__SVR4) && !defined(__svr4__) # include # endif #endif #if !defined(__SVR4) && !defined(__svr4__) # if defined(_KERNEL) && !defined(__sgi) && !defined(AIX) # include # endif #else # include # ifdef _KERNEL # include # endif # include # include #endif #include #ifdef sun # include #endif #include #include #include #include #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_auth.h" #include "netinet/ipf_stack.h" #if (__FreeBSD_version >= 300000) # include # if defined(_KERNEL) # ifndef IPFILTER_LKM # include # include # endif extern struct callout_handle fr_slowtimer_ch; # endif #endif #if defined(__NetBSD__) && (__NetBSD_Version__ >= 104230000) # include extern struct callout fr_slowtimer_ch; #endif #if defined(__OpenBSD__) # include extern struct timeout fr_slowtimer_ch; #endif /* END OF INCLUDES */ #if !defined(lint) static const char sccsid[] = "@(#)ip_frag.c 1.11 3/24/96 (C) 1993-2000 Darren Reed"; static const char rcsid[] = "@(#)$Id: ip_frag.c,v 2.77.2.5 2005/08/11 14:33:10 darrenr Exp $"; #endif static INLINE int ipfr_index __P((fr_info_t *, ipfr_t *)); static ipfr_t *ipfr_newfrag __P((fr_info_t *, u_32_t, ipfr_t **)); static ipfr_t *fr_fraglookup __P((fr_info_t *, ipfr_t **)); static void fr_fragdelete __P((ipfr_t *, ipfr_t ***, ipf_stack_t *)); /* ------------------------------------------------------------------------ */ /* Function: fr_fraginit */ /* Returns: int - 0 == success, -1 == error */ /* Parameters: Nil */ /* */ /* Initialise the hash tables for the fragment cache lookups. */ /* ------------------------------------------------------------------------ */ int fr_fraginit(ifs) ipf_stack_t *ifs; { ifs->ifs_ipfr_tail = &ifs->ifs_ipfr_list; ifs->ifs_ipfr_nattail = &ifs->ifs_ipfr_natlist; ifs->ifs_ipfr_ipidtail = &ifs->ifs_ipfr_ipidlist; /* the IP frag related variables are set in ipftuneable_setdefs() to * their default values */ KMALLOCS(ifs->ifs_ipfr_heads, ipfr_t **, ifs->ifs_ipfr_size * sizeof(ipfr_t *)); if (ifs->ifs_ipfr_heads == NULL) return -1; bzero((char *)ifs->ifs_ipfr_heads, ifs->ifs_ipfr_size * sizeof(ipfr_t *)); KMALLOCS(ifs->ifs_ipfr_nattab, ipfr_t **, ifs->ifs_ipfr_size * sizeof(ipfr_t *)); if (ifs->ifs_ipfr_nattab == NULL) return -1; bzero((char *)ifs->ifs_ipfr_nattab, ifs->ifs_ipfr_size * sizeof(ipfr_t *)); KMALLOCS(ifs->ifs_ipfr_ipidtab, ipfr_t **, ifs->ifs_ipfr_size * sizeof(ipfr_t *)); if (ifs->ifs_ipfr_ipidtab == NULL) return -1; bzero((char *)ifs->ifs_ipfr_ipidtab, ifs->ifs_ipfr_size * sizeof(ipfr_t *)); RWLOCK_INIT(&ifs->ifs_ipf_frag, "ipf fragment rwlock"); /* Initialise frblock with "block in all" */ bzero((char *)&ifs->ifs_frblock, sizeof(ifs->ifs_frblock)); ifs->ifs_frblock.fr_flags = FR_BLOCK|FR_INQUE; /* block in */ ifs->ifs_frblock.fr_ref = 1; ifs->ifs_fr_frag_init = 1; return 0; } /* ------------------------------------------------------------------------ */ /* Function: fr_fragunload */ /* Returns: Nil */ /* Parameters: Nil */ /* */ /* Free all memory allocated whilst running and from initialisation. */ /* ------------------------------------------------------------------------ */ void fr_fragunload(ifs) ipf_stack_t *ifs; { if (ifs->ifs_fr_frag_init == 1) { fr_fragclear(ifs); RW_DESTROY(&ifs->ifs_ipf_frag); ifs->ifs_fr_frag_init = 0; } if (ifs->ifs_ipfr_heads != NULL) { KFREES(ifs->ifs_ipfr_heads, ifs->ifs_ipfr_size * sizeof(ipfr_t *)); } ifs->ifs_ipfr_heads = NULL; if (ifs->ifs_ipfr_nattab != NULL) { KFREES(ifs->ifs_ipfr_nattab, ifs->ifs_ipfr_size * sizeof(ipfr_t *)); } ifs->ifs_ipfr_nattab = NULL; if (ifs->ifs_ipfr_ipidtab != NULL) { KFREES(ifs->ifs_ipfr_ipidtab, ifs->ifs_ipfr_size * sizeof(ipfr_t *)); } ifs->ifs_ipfr_ipidtab = NULL; } /* ------------------------------------------------------------------------ */ /* Function: fr_fragstats */ /* Returns: ipfrstat_t* - pointer to struct with current frag stats */ /* Parameters: Nil */ /* */ /* Updates ipfr_stats with current information and returns a pointer to it */ /* ------------------------------------------------------------------------ */ ipfrstat_t *fr_fragstats(ifs) ipf_stack_t *ifs; { ifs->ifs_ipfr_stats.ifs_table = ifs->ifs_ipfr_heads; ifs->ifs_ipfr_stats.ifs_nattab = ifs->ifs_ipfr_nattab; ifs->ifs_ipfr_stats.ifs_inuse = ifs->ifs_ipfr_inuse; return &ifs->ifs_ipfr_stats; } /* ------------------------------------------------------------------------ */ /* Function: ipfr_index */ /* Returns: int - index in fragment table for given packet */ /* Parameters: fin(I) - pointer to packet information */ /* frag(O) - pointer to ipfr_t structure to fill */ /* */ /* Compute the index in the fragment table while filling the per packet */ /* part of the fragment state. */ /* ------------------------------------------------------------------------ */ static INLINE int ipfr_index(fin, frag) fr_info_t *fin; ipfr_t *frag; { u_int idx; /* * For fragments, we record protocol, packet id, TOS and both IP#'s * (these should all be the same for all fragments of a packet). * * build up a hash value to index the table with. */ #ifdef USE_INET6 if (fin->fin_v == 6) { ip6_t *ip6 = (ip6_t *)fin->fin_ip; frag->ipfr_p = fin->fin_fi.fi_p; frag->ipfr_id = fin->fin_id; frag->ipfr_tos = ip6->ip6_flow & IPV6_FLOWINFO_MASK; frag->ipfr_src.in6 = ip6->ip6_src; frag->ipfr_dst.in6 = ip6->ip6_dst; } else #endif { ip_t *ip = fin->fin_ip; frag->ipfr_p = ip->ip_p; frag->ipfr_id = ip->ip_id; frag->ipfr_tos = ip->ip_tos; frag->ipfr_src.in4.s_addr = ip->ip_src.s_addr; frag->ipfr_src.i6[1] = 0; frag->ipfr_src.i6[2] = 0; frag->ipfr_src.i6[3] = 0; frag->ipfr_dst.in4.s_addr = ip->ip_dst.s_addr; frag->ipfr_dst.i6[1] = 0; frag->ipfr_dst.i6[2] = 0; frag->ipfr_dst.i6[3] = 0; } frag->ipfr_ifp = fin->fin_ifp; frag->ipfr_optmsk = fin->fin_fi.fi_optmsk & IPF_OPTCOPY; frag->ipfr_secmsk = fin->fin_fi.fi_secmsk; frag->ipfr_auth = fin->fin_fi.fi_auth; idx = frag->ipfr_p; idx += frag->ipfr_id; idx += frag->ipfr_src.i6[0]; idx += frag->ipfr_src.i6[1]; idx += frag->ipfr_src.i6[2]; idx += frag->ipfr_src.i6[3]; idx += frag->ipfr_dst.i6[0]; idx += frag->ipfr_dst.i6[1]; idx += frag->ipfr_dst.i6[2]; idx += frag->ipfr_dst.i6[3]; idx *= 127; idx %= IPFT_SIZE; return idx; } /* ------------------------------------------------------------------------ */ /* Function: ipfr_newfrag */ /* Returns: ipfr_t * - pointer to fragment cache state info or NULL */ /* Parameters: fin(I) - pointer to packet information */ /* table(I) - pointer to frag table to add to */ /* */ /* Add a new entry to the fragment cache, registering it as having come */ /* through this box, with the result of the filter operation. */ /* ------------------------------------------------------------------------ */ static ipfr_t *ipfr_newfrag(fin, pass, table) fr_info_t *fin; u_32_t pass; ipfr_t *table[]; { ipfr_t *fra, frag; u_int idx, off; ipf_stack_t *ifs = fin->fin_ifs; if (ifs->ifs_ipfr_inuse >= ifs->ifs_ipfr_size) return NULL; if ((fin->fin_flx & (FI_FRAG|FI_BAD)) != FI_FRAG) return NULL; if (pass & FR_FRSTRICT) if (fin->fin_off != 0) return NULL; idx = ipfr_index(fin, &frag); /* * first, make sure it isn't already there... */ for (fra = table[idx]; (fra != NULL); fra = fra->ipfr_hnext) if (!bcmp((char *)&frag.ipfr_ifp, (char *)&fra->ipfr_ifp, IPFR_CMPSZ)) { ifs->ifs_ipfr_stats.ifs_exists++; return NULL; } /* * allocate some memory, if possible, if not, just record that we * failed to do so. */ KMALLOC(fra, ipfr_t *); if (fra == NULL) { ifs->ifs_ipfr_stats.ifs_nomem++; return NULL; } fra->ipfr_rule = fin->fin_fr; if (fra->ipfr_rule != NULL) { frentry_t *fr; fr = fin->fin_fr; MUTEX_ENTER(&fr->fr_lock); fr->fr_ref++; MUTEX_EXIT(&fr->fr_lock); } /* * Insert the fragment into the fragment table, copy the struct used * in the search using bcopy rather than reassign each field. * Set the ttl to the default. */ if ((fra->ipfr_hnext = table[idx]) != NULL) table[idx]->ipfr_hprev = &fra->ipfr_hnext; fra->ipfr_hprev = table + idx; fra->ipfr_data = NULL; table[idx] = fra; bcopy((char *)&frag.ipfr_ifp, (char *)&fra->ipfr_ifp, IPFR_CMPSZ); fra->ipfr_ttl = ifs->ifs_fr_ticks + ifs->ifs_fr_ipfrttl; /* * Compute the offset of the expected start of the next packet. */ off = fin->fin_off >> 3; if (off == 0) { fra->ipfr_seen0 = 1; } else { fra->ipfr_seen0 = 0; } fra->ipfr_off = off + fin->fin_dlen; fra->ipfr_pass = pass; fra->ipfr_ref = 1; ifs->ifs_ipfr_stats.ifs_new++; ifs->ifs_ipfr_inuse++; return fra; } /* ------------------------------------------------------------------------ */ /* Function: fr_newfrag */ /* Returns: int - 0 == success, -1 == error */ /* Parameters: fin(I) - pointer to packet information */ /* */ /* Add a new entry to the fragment cache table based on the current packet */ /* ------------------------------------------------------------------------ */ int fr_newfrag(fin, pass) u_32_t pass; fr_info_t *fin; { ipfr_t *fra; ipf_stack_t *ifs = fin->fin_ifs; if (ifs->ifs_fr_frag_lock != 0) return -1; WRITE_ENTER(&ifs->ifs_ipf_frag); fra = ipfr_newfrag(fin, pass, ifs->ifs_ipfr_heads); if (fra != NULL) { *ifs->ifs_ipfr_tail = fra; fra->ipfr_prev = ifs->ifs_ipfr_tail; ifs->ifs_ipfr_tail = &fra->ipfr_next; if (ifs->ifs_ipfr_list == NULL) ifs->ifs_ipfr_list = fra; fra->ipfr_next = NULL; } RWLOCK_EXIT(&ifs->ifs_ipf_frag); return fra ? 0 : -1; } /* ------------------------------------------------------------------------ */ /* Function: fr_nat_newfrag */ /* Returns: int - 0 == success, -1 == error */ /* Parameters: fin(I) - pointer to packet information */ /* nat(I) - pointer to NAT structure */ /* */ /* Create a new NAT fragment cache entry based on the current packet and */ /* the NAT structure for this "session". */ /* ------------------------------------------------------------------------ */ int fr_nat_newfrag(fin, pass, nat) fr_info_t *fin; u_32_t pass; nat_t *nat; { ipfr_t *fra; ipf_stack_t *ifs = fin->fin_ifs; if (ifs->ifs_fr_frag_lock != 0) return 0; WRITE_ENTER(&ifs->ifs_ipf_natfrag); fra = ipfr_newfrag(fin, pass, ifs->ifs_ipfr_nattab); if (fra != NULL) { fra->ipfr_data = nat; nat->nat_data = fra; *ifs->ifs_ipfr_nattail = fra; fra->ipfr_prev = ifs->ifs_ipfr_nattail; ifs->ifs_ipfr_nattail = &fra->ipfr_next; fra->ipfr_next = NULL; } RWLOCK_EXIT(&ifs->ifs_ipf_natfrag); return fra ? 0 : -1; } /* ------------------------------------------------------------------------ */ /* Function: fr_ipid_newfrag */ /* Returns: int - 0 == success, -1 == error */ /* Parameters: fin(I) - pointer to packet information */ /* ipid(I) - new IP ID for this fragmented packet */ /* */ /* Create a new fragment cache entry for this packet and store, as a data */ /* pointer, the new IP ID value. */ /* ------------------------------------------------------------------------ */ int fr_ipid_newfrag(fin, ipid) fr_info_t *fin; u_32_t ipid; { ipfr_t *fra; ipf_stack_t *ifs = fin->fin_ifs; if (ifs->ifs_fr_frag_lock) return 0; WRITE_ENTER(&ifs->ifs_ipf_ipidfrag); fra = ipfr_newfrag(fin, 0, ifs->ifs_ipfr_ipidtab); if (fra != NULL) { fra->ipfr_data = (void *)(uintptr_t)ipid; *ifs->ifs_ipfr_ipidtail = fra; fra->ipfr_prev = ifs->ifs_ipfr_ipidtail; ifs->ifs_ipfr_ipidtail = &fra->ipfr_next; fra->ipfr_next = NULL; } RWLOCK_EXIT(&ifs->ifs_ipf_ipidfrag); return fra ? 0 : -1; } /* ------------------------------------------------------------------------ */ /* Function: fr_fraglookup */ /* Returns: ipfr_t * - pointer to ipfr_t structure if there's a */ /* matching entry in the frag table, else NULL */ /* Parameters: fin(I) - pointer to packet information */ /* table(I) - pointer to fragment cache table to search */ /* */ /* Check the fragment cache to see if there is already a record of this */ /* packet with its filter result known. */ /* ------------------------------------------------------------------------ */ static ipfr_t *fr_fraglookup(fin, table) fr_info_t *fin; ipfr_t *table[]; { ipfr_t *f, frag; u_int idx; ipf_stack_t *ifs = fin->fin_ifs; if ((fin->fin_flx & (FI_FRAG|FI_BAD)) != FI_FRAG) return NULL; /* * For fragments, we record protocol, packet id, TOS and both IP#'s * (these should all be the same for all fragments of a packet). * * build up a hash value to index the table with. */ idx = ipfr_index(fin, &frag); /* * check the table, careful to only compare the right amount of data */ for (f = table[idx]; f; f = f->ipfr_hnext) if (!bcmp((char *)&frag.ipfr_ifp, (char *)&f->ipfr_ifp, IPFR_CMPSZ)) { u_short off; /* * We don't want to let short packets match because * they could be compromising the security of other * rules that want to match on layer 4 fields (and * can't because they have been fragmented off.) * Why do this check here? The counter acts as an * indicator of this kind of attack, whereas if it was * elsewhere, it wouldn't know if other matching * packets had been seen. */ if (fin->fin_flx & FI_SHORT) { ATOMIC_INCL(ifs->ifs_ipfr_stats.ifs_short); continue; } /* * XXX - We really need to be guarding against the * retransmission of (src,dst,id,offset-range) here * because a fragmented packet is never resent with * the same IP ID# (or shouldn't). */ off = fin->fin_off >> 3; if (f->ipfr_seen0) { if (off == 0) { ATOMIC_INCL(ifs->ifs_ipfr_stats.ifs_retrans0); continue; } } else if (off == 0) { f->ipfr_seen0 = 1; } if (f != table[idx]) { ipfr_t **fp; /* * Move fragment info. to the top of the list * to speed up searches. First, delink... */ fp = f->ipfr_hprev; (*fp) = f->ipfr_hnext; if (f->ipfr_hnext != NULL) f->ipfr_hnext->ipfr_hprev = fp; /* * Then put back at the top of the chain. */ f->ipfr_hnext = table[idx]; table[idx]->ipfr_hprev = &f->ipfr_hnext; f->ipfr_hprev = table + idx; table[idx] = f; } /* * If we've follwed the fragments, and this is the * last (in order), shrink expiration time. */ if (off == f->ipfr_off) { if (!(fin->fin_flx & FI_MOREFRAG)) f->ipfr_ttl = ifs->ifs_fr_ticks + 1; f->ipfr_off = fin->fin_dlen + off; } else if (f->ipfr_pass & FR_FRSTRICT) continue; ATOMIC_INCL(ifs->ifs_ipfr_stats.ifs_hits); return f; } return NULL; } /* ------------------------------------------------------------------------ */ /* Function: fr_nat_knownfrag */ /* Returns: nat_t* - pointer to 'parent' NAT structure if frag table */ /* match found, else NULL */ /* Parameters: fin(I) - pointer to packet information */ /* */ /* Functional interface for NAT lookups of the NAT fragment cache */ /* ------------------------------------------------------------------------ */ nat_t *fr_nat_knownfrag(fin) fr_info_t *fin; { nat_t *nat; ipfr_t *ipf; ipf_stack_t *ifs = fin->fin_ifs; if (ifs->ifs_fr_frag_lock || !ifs->ifs_ipfr_natlist) return NULL; READ_ENTER(&ifs->ifs_ipf_natfrag); ipf = fr_fraglookup(fin, ifs->ifs_ipfr_nattab); if (ipf != NULL) { nat = ipf->ipfr_data; /* * This is the last fragment for this packet. */ if ((ipf->ipfr_ttl == ifs->ifs_fr_ticks + 1) && (nat != NULL)) { nat->nat_data = NULL; ipf->ipfr_data = NULL; } } else nat = NULL; RWLOCK_EXIT(&ifs->ifs_ipf_natfrag); return nat; } /* ------------------------------------------------------------------------ */ /* Function: fr_ipid_knownfrag */ /* Returns: u_32_t - IPv4 ID for this packet if match found, else */ /* return 0xfffffff to indicate no match. */ /* Parameters: fin(I) - pointer to packet information */ /* */ /* Functional interface for IP ID lookups of the IP ID fragment cache */ /* ------------------------------------------------------------------------ */ u_32_t fr_ipid_knownfrag(fin) fr_info_t *fin; { ipfr_t *ipf; u_32_t id; ipf_stack_t *ifs = fin->fin_ifs; if (ifs->ifs_fr_frag_lock || !ifs->ifs_ipfr_ipidlist) return 0xffffffff; READ_ENTER(&ifs->ifs_ipf_ipidfrag); ipf = fr_fraglookup(fin, ifs->ifs_ipfr_ipidtab); if (ipf != NULL) id = (u_32_t)(uintptr_t)ipf->ipfr_data; else id = 0xffffffff; RWLOCK_EXIT(&ifs->ifs_ipf_ipidfrag); return id; } /* ------------------------------------------------------------------------ */ /* Function: fr_knownfrag */ /* Returns: frentry_t* - pointer to filter rule if a match is found in */ /* the frag cache table, else NULL. */ /* Parameters: fin(I) - pointer to packet information */ /* passp(O) - pointer to where to store rule flags resturned */ /* */ /* Functional interface for normal lookups of the fragment cache. If a */ /* match is found, return the rule pointer and flags from the rule, except */ /* that if FR_LOGFIRST is set, reset FR_LOG. */ /* ------------------------------------------------------------------------ */ frentry_t *fr_knownfrag(fin, passp) fr_info_t *fin; u_32_t *passp; { frentry_t *fr = NULL; ipfr_t *fra; u_32_t pass, oflx; ipf_stack_t *ifs = fin->fin_ifs; if (ifs->ifs_fr_frag_lock || (ifs->ifs_ipfr_list == NULL)) return NULL; READ_ENTER(&ifs->ifs_ipf_frag); oflx = fin->fin_flx; fra = fr_fraglookup(fin, ifs->ifs_ipfr_heads); if (fra != NULL) { fr = fra->ipfr_rule; fin->fin_fr = fr; if (fr != NULL) { pass = fr->fr_flags; if ((pass & FR_LOGFIRST) != 0) pass &= ~(FR_LOGFIRST|FR_LOG); *passp = pass; } } if (!(oflx & FI_BAD) && (fin->fin_flx & FI_BAD)) { *passp &= ~FR_CMDMASK; *passp |= FR_BLOCK; fr = &ifs->ifs_frblock; } RWLOCK_EXIT(&ifs->ifs_ipf_frag); return fr; } /* ------------------------------------------------------------------------ */ /* Function: fr_forget */ /* Returns: Nil */ /* Parameters: ptr(I) - pointer to data structure */ /* */ /* Search through all of the fragment cache entries and wherever a pointer */ /* is found to match ptr, reset it to NULL. */ /* ------------------------------------------------------------------------ */ void fr_forget(ptr, ifs) void *ptr; ipf_stack_t *ifs; { ipfr_t *fr; WRITE_ENTER(&ifs->ifs_ipf_frag); for (fr = ifs->ifs_ipfr_list; fr; fr = fr->ipfr_next) if (fr->ipfr_data == ptr) fr->ipfr_data = NULL; RWLOCK_EXIT(&ifs->ifs_ipf_frag); } /* ------------------------------------------------------------------------ */ /* Function: fr_forgetnat */ /* Returns: Nil */ /* Parameters: ptr(I) - pointer to data structure */ /* */ /* Search through all of the fragment cache entries for NAT and wherever a */ /* pointer is found to match ptr, reset it to NULL. */ /* ------------------------------------------------------------------------ */ void fr_forgetnat(ptr, ifs) void *ptr; ipf_stack_t *ifs; { ipfr_t *fr; WRITE_ENTER(&ifs->ifs_ipf_natfrag); for (fr = ifs->ifs_ipfr_natlist; fr; fr = fr->ipfr_next) if (fr->ipfr_data == ptr) fr->ipfr_data = NULL; RWLOCK_EXIT(&ifs->ifs_ipf_natfrag); } /* ------------------------------------------------------------------------ */ /* Function: fr_fragdelete */ /* Returns: Nil */ /* Parameters: fra(I) - pointer to fragment structure to delete */ /* tail(IO) - pointer to the pointer to the tail of the frag */ /* list */ /* */ /* Remove a fragment cache table entry from the table & list. Also free */ /* the filter rule it is associated with it if it is no longer used as a */ /* result of decreasing the reference count. */ /* ------------------------------------------------------------------------ */ static void fr_fragdelete(fra, tail, ifs) ipfr_t *fra, ***tail; ipf_stack_t *ifs; { frentry_t *fr; fr = fra->ipfr_rule; if (fr != NULL) (void)fr_derefrule(&fr, ifs); if (fra->ipfr_next) fra->ipfr_next->ipfr_prev = fra->ipfr_prev; *fra->ipfr_prev = fra->ipfr_next; if (*tail == &fra->ipfr_next) *tail = fra->ipfr_prev; if (fra->ipfr_hnext) fra->ipfr_hnext->ipfr_hprev = fra->ipfr_hprev; *fra->ipfr_hprev = fra->ipfr_hnext; if (fra->ipfr_ref <= 0) KFREE(fra); } /* ------------------------------------------------------------------------ */ /* Function: fr_fragclear */ /* Returns: Nil */ /* Parameters: Nil */ /* */ /* Free memory in use by fragment state information kept. Do the normal */ /* fragment state stuff first and then the NAT-fragment table. */ /* ------------------------------------------------------------------------ */ void fr_fragclear(ifs) ipf_stack_t *ifs; { ipfr_t *fra; nat_t *nat; WRITE_ENTER(&ifs->ifs_ipf_frag); while ((fra = ifs->ifs_ipfr_list) != NULL) { fra->ipfr_ref--; fr_fragdelete(fra, &ifs->ifs_ipfr_tail, ifs); } ifs->ifs_ipfr_tail = &ifs->ifs_ipfr_list; RWLOCK_EXIT(&ifs->ifs_ipf_frag); WRITE_ENTER(&ifs->ifs_ipf_nat); WRITE_ENTER(&ifs->ifs_ipf_natfrag); while ((fra = ifs->ifs_ipfr_natlist) != NULL) { nat = fra->ipfr_data; if (nat != NULL) { if (nat->nat_data == fra) nat->nat_data = NULL; } fra->ipfr_ref--; fr_fragdelete(fra, &ifs->ifs_ipfr_nattail, ifs); } ifs->ifs_ipfr_nattail = &ifs->ifs_ipfr_natlist; RWLOCK_EXIT(&ifs->ifs_ipf_natfrag); RWLOCK_EXIT(&ifs->ifs_ipf_nat); } /* ------------------------------------------------------------------------ */ /* Function: fr_fragexpire */ /* Returns: Nil */ /* Parameters: Nil */ /* */ /* Expire entries in the fragment cache table that have been there too long */ /* ------------------------------------------------------------------------ */ void fr_fragexpire(ifs) ipf_stack_t *ifs; { ipfr_t **fp, *fra; nat_t *nat; SPL_INT(s); if (ifs->ifs_fr_frag_lock) return; SPL_NET(s); WRITE_ENTER(&ifs->ifs_ipf_frag); /* * Go through the entire table, looking for entries to expire, * which is indicated by the ttl being less than or equal to * ifs_fr_ticks. */ for (fp = &ifs->ifs_ipfr_list; ((fra = *fp) != NULL); ) { if (fra->ipfr_ttl > ifs->ifs_fr_ticks) break; fra->ipfr_ref--; fr_fragdelete(fra, &ifs->ifs_ipfr_tail, ifs); ifs->ifs_ipfr_stats.ifs_expire++; ifs->ifs_ipfr_inuse--; } RWLOCK_EXIT(&ifs->ifs_ipf_frag); WRITE_ENTER(&ifs->ifs_ipf_ipidfrag); for (fp = &ifs->ifs_ipfr_ipidlist; ((fra = *fp) != NULL); ) { if (fra->ipfr_ttl > ifs->ifs_fr_ticks) break; fra->ipfr_ref--; fr_fragdelete(fra, &ifs->ifs_ipfr_ipidtail, ifs); ifs->ifs_ipfr_stats.ifs_expire++; ifs->ifs_ipfr_inuse--; } RWLOCK_EXIT(&ifs->ifs_ipf_ipidfrag); /* * Same again for the NAT table, except that if the structure also * still points to a NAT structure, and the NAT structure points back * at the one to be free'd, NULL the reference from the NAT struct. * NOTE: We need to grab both mutex's early, and in this order so as * to prevent a deadlock if both try to expire at the same time. */ WRITE_ENTER(&ifs->ifs_ipf_nat); WRITE_ENTER(&ifs->ifs_ipf_natfrag); for (fp = &ifs->ifs_ipfr_natlist; ((fra = *fp) != NULL); ) { if (fra->ipfr_ttl > ifs->ifs_fr_ticks) break; nat = fra->ipfr_data; if (nat != NULL) { if (nat->nat_data == fra) nat->nat_data = NULL; } fra->ipfr_ref--; fr_fragdelete(fra, &ifs->ifs_ipfr_nattail, ifs); ifs->ifs_ipfr_stats.ifs_expire++; ifs->ifs_ipfr_inuse--; } RWLOCK_EXIT(&ifs->ifs_ipf_natfrag); RWLOCK_EXIT(&ifs->ifs_ipf_nat); SPL_X(s); } /* ------------------------------------------------------------------------ */ /* Function: fr_slowtimer */ /* Returns: Nil */ /* Parameters: Nil */ /* */ /* Slowly expire held state for fragments. Timeouts are set * in */ /* expectation of this being called twice per second. */ /* ------------------------------------------------------------------------ */ #if !defined(_KERNEL) || (!SOLARIS && !defined(__hpux) && !defined(__sgi) && \ !defined(__osf__) && !defined(linux)) # if defined(_KERNEL) && ((BSD >= 199103) || defined(__sgi)) void fr_slowtimer __P((void *arg)) # else int fr_slowtimer(void *arg) # endif { ipf_stack_t *ifs = arg; READ_ENTER(&ifs->ifs_ipf_global); fr_fragexpire(ifs); fr_timeoutstate(ifs); fr_natexpire(ifs); fr_authexpire(ifs); ifs->ifs_fr_ticks++; if (ifs->ifs_fr_running <= 0) goto done; # ifdef _KERNEL # if defined(__NetBSD__) && (__NetBSD_Version__ >= 104240000) callout_reset(&fr_slowtimer_ch, hz / 2, fr_slowtimer, NULL); # else # if defined(__OpenBSD__) timeout_add(&fr_slowtimer_ch, hz/2); # else # if (__FreeBSD_version >= 300000) fr_slowtimer_ch = timeout(fr_slowtimer, NULL, hz/2); # else # ifdef linux ; # else timeout(fr_slowtimer, NULL, hz/2); # endif # endif /* FreeBSD */ # endif /* OpenBSD */ # endif /* NetBSD */ # endif done: RWLOCK_EXIT(&ifs->ifs_ipf_global); # if (BSD < 199103) || !defined(_KERNEL) return 0; # endif } #endif /* !SOLARIS && !defined(__hpux) && !defined(__sgi) */ /*ARGSUSED*/ int fr_nextfrag(token, itp, top, tail, lock, ifs) ipftoken_t *token; ipfgeniter_t *itp; ipfr_t **top, ***tail; ipfrwlock_t *lock; ipf_stack_t *ifs; { ipfr_t *frag, *next, zero; int error = 0; READ_ENTER(lock); /* * Retrieve "previous" entry from token and find the next entry. */ frag = token->ipt_data; if (frag == NULL) next = *top; else next = frag->ipfr_next; /* * If we found an entry, add reference to it and update token. * Otherwise, zero out data to be returned and NULL out token. */ if (next != NULL) { ATOMIC_INC(next->ipfr_ref); token->ipt_data = next; } else { bzero(&zero, sizeof(zero)); next = &zero; token->ipt_data = NULL; } /* * Now that we have ref, it's save to give up lock. */ RWLOCK_EXIT(lock); /* * Copy out data and clean up references and token as needed. */ error = COPYOUT(next, itp->igi_data, sizeof(*next)); if (error != 0) error = EFAULT; if (token->ipt_data == NULL) { ipf_freetoken(token, ifs); } else { if (frag != NULL) fr_fragderef(&frag, lock, ifs); if (next->ipfr_next == NULL) ipf_freetoken(token, ifs); } return error; } void fr_fragderef(frp, lock, ifs) ipfr_t **frp; ipfrwlock_t *lock; ipf_stack_t *ifs; { ipfr_t *fra; fra = *frp; *frp = NULL; WRITE_ENTER(lock); fra->ipfr_ref--; if (fra->ipfr_ref <= 0) { KFREE(fra); ifs->ifs_ipfr_stats.ifs_expire++; ifs->ifs_ipfr_inuse--; } RWLOCK_EXIT(lock); }