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-rw-r--r--ip_frag.c858
1 files changed, 858 insertions, 0 deletions
diff --git a/ip_frag.c b/ip_frag.c
new file mode 100644
index 0000000..087ca19
--- /dev/null
+++ b/ip_frag.c
@@ -0,0 +1,858 @@
+/* $NetBSD$ */
+
+/*
+ * Copyright (C) 1993-2003 by Darren Reed.
+ *
+ * See the IPFILTER.LICENCE file for details on licencing.
+ */
+#if defined(KERNEL) || defined(_KERNEL)
+# undef KERNEL
+# undef _KERNEL
+# define KERNEL 1
+# define _KERNEL 1
+#endif
+#include <sys/errno.h>
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/file.h>
+#ifdef __hpux
+# include <sys/timeout.h>
+#endif
+#if !defined(_KERNEL)
+# include <stdio.h>
+# include <string.h>
+# include <stdlib.h>
+# define _KERNEL
+# ifdef __OpenBSD__
+struct file;
+# endif
+# include <sys/uio.h>
+# undef _KERNEL
+#endif
+#if defined(_KERNEL) && (__FreeBSD_version >= 220000)
+# include <sys/filio.h>
+# include <sys/fcntl.h>
+#else
+# include <sys/ioctl.h>
+#endif
+#if !defined(linux)
+# include <sys/protosw.h>
+#endif
+#include <sys/socket.h>
+#if defined(_KERNEL)
+# include <sys/systm.h>
+# if !defined(__SVR4) && !defined(__svr4__)
+# include <sys/mbuf.h>
+# endif
+#endif
+#if !defined(__SVR4) && !defined(__svr4__)
+# if defined(_KERNEL) && !defined(__sgi)
+# include <sys/kernel.h>
+# endif
+#else
+# include <sys/byteorder.h>
+# ifdef _KERNEL
+# include <sys/dditypes.h>
+# endif
+# include <sys/stream.h>
+# include <sys/kmem.h>
+#endif
+#include <net/if.h>
+#ifdef sun
+# include <net/af.h>
+#endif
+#include <net/route.h>
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#if !defined(linux)
+# include <netinet/ip_var.h>
+#endif
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <netinet/ip_icmp.h>
+#include "netinet/ip_compat.h"
+#include <netinet/tcpip.h>
+#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/ip_proxy.h"
+#if (__FreeBSD_version >= 300000)
+# include <sys/malloc.h>
+# if defined(_KERNEL)
+# ifndef IPFILTER_LKM
+# include <sys/libkern.h>
+# include <sys/systm.h>
+# endif
+extern struct callout_handle fr_slowtimer_ch;
+# endif
+#endif
+#if defined(__NetBSD__) && (__NetBSD_Version__ >= 104230000)
+# include <sys/callout.h>
+extern struct callout fr_slowtimer_ch;
+#endif
+#if defined(__OpenBSD__)
+# include <sys/timeout.h>
+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 2004/01/27 00:24:54 darrenr Exp";
+#endif
+
+
+static ipfr_t *ipfr_list = NULL;
+static ipfr_t **ipfr_tail = &ipfr_list;
+static ipfr_t **ipfr_heads;
+
+static ipfr_t *ipfr_natlist = NULL;
+static ipfr_t **ipfr_nattail = &ipfr_natlist;
+static ipfr_t **ipfr_nattab;
+
+static ipfr_t *ipfr_ipidlist = NULL;
+static ipfr_t **ipfr_ipidtail = &ipfr_ipidlist;
+static ipfr_t **ipfr_ipidtab;
+
+static ipfrstat_t ipfr_stats;
+static int ipfr_inuse = 0;
+int ipfr_size = IPFT_SIZE;
+
+int fr_ipfrttl = 120; /* 60 seconds */
+int fr_frag_lock = 0;
+int fr_frag_init = 0;
+u_long fr_ticks = 0;
+
+
+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 ***));
+
+
+/* ------------------------------------------------------------------------ */
+/* Function: fr_fraginit */
+/* Returns: int - 0 == success, -1 == error */
+/* Parameters: Nil */
+/* */
+/* Initialise the hash tables for the fragment cache lookups. */
+/* ------------------------------------------------------------------------ */
+int fr_fraginit()
+{
+ KMALLOCS(ipfr_heads, ipfr_t **, ipfr_size * sizeof(ipfr_t *));
+ if (ipfr_heads == NULL)
+ return -1;
+ bzero((char *)ipfr_heads, ipfr_size * sizeof(ipfr_t *));
+
+ KMALLOCS(ipfr_nattab, ipfr_t **, ipfr_size * sizeof(ipfr_t *));
+ if (ipfr_nattab == NULL)
+ return -1;
+ bzero((char *)ipfr_nattab, ipfr_size * sizeof(ipfr_t *));
+
+ KMALLOCS(ipfr_ipidtab, ipfr_t **, ipfr_size * sizeof(ipfr_t *));
+ if (ipfr_ipidtab == NULL)
+ return -1;
+ bzero((char *)ipfr_ipidtab, ipfr_size * sizeof(ipfr_t *));
+
+ RWLOCK_INIT(&ipf_frag, "ipf fragment rwlock");
+ 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()
+{
+ if (fr_frag_init == 1) {
+ fr_fragclear();
+
+ RW_DESTROY(&ipf_frag);
+ fr_frag_init = 0;
+ }
+
+ if (ipfr_heads != NULL)
+ KFREES(ipfr_heads, ipfr_size * sizeof(ipfr_t *));
+ ipfr_heads = NULL;
+
+ if (ipfr_nattab != NULL)
+ KFREES(ipfr_nattab, ipfr_size * sizeof(ipfr_t *));
+ ipfr_nattab = NULL;
+
+ if (ipfr_ipidtab != NULL)
+ KFREES(ipfr_ipidtab, ipfr_size * sizeof(ipfr_t *));
+ 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()
+{
+ ipfr_stats.ifs_table = ipfr_heads;
+ ipfr_stats.ifs_nattab = ipfr_nattab;
+ ipfr_stats.ifs_inuse = ipfr_inuse;
+ return &ipfr_stats;
+}
+
+
+/* ------------------------------------------------------------------------ */
+/* 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;
+ ip_t *ip;
+
+ if (ipfr_inuse >= IPFT_SIZE)
+ return NULL;
+
+ if ((fin->fin_flx & (FI_FRAG|FI_BAD)) != FI_FRAG)
+ return NULL;
+
+ ip = fin->fin_ip;
+
+ if (pass & FR_FRSTRICT)
+ if ((ip->ip_off & IP_OFFMASK) != 0)
+ return NULL;
+
+ frag.ipfr_p = ip->ip_p;
+ idx = ip->ip_p;
+ frag.ipfr_id = ip->ip_id;
+ idx += ip->ip_id;
+ frag.ipfr_tos = ip->ip_tos;
+ frag.ipfr_src.s_addr = ip->ip_src.s_addr;
+ idx += ip->ip_src.s_addr;
+ frag.ipfr_dst.s_addr = ip->ip_dst.s_addr;
+ idx += ip->ip_dst.s_addr;
+ frag.ipfr_ifp = fin->fin_ifp;
+ idx *= 127;
+ idx %= IPFT_SIZE;
+
+ 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;
+
+ /*
+ * 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)) {
+ 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) {
+ ipfr_stats.ifs_nomem++;
+ return NULL;
+ }
+
+ if ((fra->ipfr_rule = fin->fin_fr) != NULL)
+ fin->fin_fr->fr_ref++;
+
+ /*
+ * 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 = fr_ticks + fr_ipfrttl;
+
+ /*
+ * Compute the offset of the expected start of the next packet.
+ */
+ off = ip->ip_off & IP_OFFMASK;
+ if (off == 0)
+ fra->ipfr_seen0 = 1;
+ fra->ipfr_off = off + (fin->fin_dlen >> 3);
+ fra->ipfr_pass = pass;
+ ipfr_stats.ifs_new++;
+ 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;
+
+ if ((fin->fin_v != 4) || (fr_frag_lock != 0))
+ return -1;
+
+ WRITE_ENTER(&ipf_frag);
+ fra = ipfr_newfrag(fin, pass, ipfr_heads);
+ if (fra != NULL) {
+ *ipfr_tail = fra;
+ fra->ipfr_prev = ipfr_tail;
+ ipfr_tail = &fra->ipfr_next;
+ if (ipfr_list == NULL)
+ ipfr_list = fra;
+ fra->ipfr_next = NULL;
+ }
+ RWLOCK_EXIT(&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;
+
+ if ((fin->fin_v != 4) || (fr_frag_lock != 0))
+ return 0;
+
+ WRITE_ENTER(&ipf_natfrag);
+ fra = ipfr_newfrag(fin, pass, ipfr_nattab);
+ if (fra != NULL) {
+ fra->ipfr_data = nat;
+ nat->nat_data = fra;
+ *ipfr_nattail = fra;
+ fra->ipfr_prev = ipfr_nattail;
+ ipfr_nattail = &fra->ipfr_next;
+ fra->ipfr_next = NULL;
+ }
+ RWLOCK_EXIT(&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;
+
+ if ((fin->fin_v != 4) || (fr_frag_lock))
+ return 0;
+
+ WRITE_ENTER(&ipf_ipidfrag);
+ fra = ipfr_newfrag(fin, 0, ipfr_ipidtab);
+ if (fra != NULL) {
+ fra->ipfr_data = (void *)ipid;
+ *ipfr_ipidtail = fra;
+ fra->ipfr_prev = ipfr_ipidtail;
+ ipfr_ipidtail = &fra->ipfr_next;
+ fra->ipfr_next = NULL;
+ }
+ RWLOCK_EXIT(&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;
+ ip_t *ip;
+
+ 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.
+ */
+ ip = fin->fin_ip;
+ frag.ipfr_p = ip->ip_p;
+ idx = ip->ip_p;
+ frag.ipfr_id = ip->ip_id;
+ idx += ip->ip_id;
+ frag.ipfr_tos = ip->ip_tos;
+ frag.ipfr_src.s_addr = ip->ip_src.s_addr;
+ idx += ip->ip_src.s_addr;
+ frag.ipfr_dst.s_addr = ip->ip_dst.s_addr;
+ idx += ip->ip_dst.s_addr;
+ frag.ipfr_ifp = fin->fin_ifp;
+ idx *= 127;
+ idx %= IPFT_SIZE;
+
+ 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;
+
+ /*
+ * 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(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 = ip->ip_off & IP_OFFMASK;
+ if (f->ipfr_seen0) {
+ if (off == 0) {
+ ATOMIC_INCL(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 (!(ip->ip_off & IP_MF))
+ f->ipfr_ttl = fr_ticks + 1;
+ f->ipfr_off = (fin->fin_dlen >> 3) + off;
+ } else if (f->ipfr_pass & FR_FRSTRICT)
+ continue;
+ ATOMIC_INCL(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;
+
+ if ((fin->fin_v != 4) || (fr_frag_lock) || !ipfr_natlist)
+ return NULL;
+ READ_ENTER(&ipf_natfrag);
+ ipf = fr_fraglookup(fin, ipfr_nattab);
+ if (ipf != NULL) {
+ nat = ipf->ipfr_data;
+ /*
+ * This is the last fragment for this packet.
+ */
+ if ((ipf->ipfr_ttl == fr_ticks + 1) && (nat != NULL)) {
+ nat->nat_data = NULL;
+ ipf->ipfr_data = NULL;
+ }
+ } else
+ nat = NULL;
+ RWLOCK_EXIT(&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;
+
+ if ((fin->fin_v != 4) || (fr_frag_lock) || !ipfr_ipidlist)
+ return 0xffffffff;
+
+ READ_ENTER(&ipf_ipidfrag);
+ ipf = fr_fraglookup(fin, ipfr_ipidtab);
+ if (ipf != NULL)
+ id = (u_32_t)ipf->ipfr_data;
+ else
+ id = 0xffffffff;
+ RWLOCK_EXIT(&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;
+
+ if ((fin->fin_v != 4) || (fr_frag_lock) || (ipfr_list == NULL))
+ return NULL;
+
+ READ_ENTER(&ipf_frag);
+ fra = fr_fraglookup(fin, 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;
+ }
+ }
+ RWLOCK_EXIT(&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)
+void *ptr;
+{
+ ipfr_t *fr;
+
+ WRITE_ENTER(&ipf_frag);
+ for (fr = ipfr_list; fr; fr = fr->ipfr_next)
+ if (fr->ipfr_data == ptr)
+ fr->ipfr_data = NULL;
+ RWLOCK_EXIT(&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)
+void *ptr;
+{
+ ipfr_t *fr;
+
+ WRITE_ENTER(&ipf_natfrag);
+ for (fr = ipfr_natlist; fr; fr = fr->ipfr_next)
+ if (fr->ipfr_data == ptr)
+ fr->ipfr_data = NULL;
+ RWLOCK_EXIT(&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)
+ipfr_t *fra, ***tail;
+{
+ frentry_t *fr;
+
+ fr = fra->ipfr_rule;
+ if (fr != NULL)
+ (void)fr_derefrule(&fr);
+
+ 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;
+ 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()
+{
+ ipfr_t *fra;
+ nat_t *nat;
+
+ WRITE_ENTER(&ipf_frag);
+ while ((fra = ipfr_list) != NULL)
+ fr_fragdelete(fra, &ipfr_tail);
+ ipfr_tail = &ipfr_list;
+ RWLOCK_EXIT(&ipf_frag);
+
+ WRITE_ENTER(&ipf_nat);
+ WRITE_ENTER(&ipf_natfrag);
+ while ((fra = ipfr_natlist) != NULL) {
+ nat = fra->ipfr_data;
+ if (nat != NULL) {
+ if (nat->nat_data == fra)
+ nat->nat_data = NULL;
+ }
+ fr_fragdelete(fra, &ipfr_nattail);
+ }
+ ipfr_nattail = &ipfr_natlist;
+ RWLOCK_EXIT(&ipf_natfrag);
+ RWLOCK_EXIT(&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()
+{
+ ipfr_t **fp, *fra;
+ nat_t *nat;
+#if defined(USE_SPL) && defined(_KERNEL)
+ int s;
+#endif
+
+ if (fr_frag_lock)
+ return;
+
+ SPL_NET(s);
+ WRITE_ENTER(&ipf_frag);
+ /*
+ * Go through the entire table, looking for entries to expire,
+ * which is indicated by the ttl being less than or equal to fr_ticks.
+ */
+ for (fp = &ipfr_list; ((fra = *fp) != NULL); ) {
+ if (fra->ipfr_ttl > fr_ticks)
+ break;
+ fr_fragdelete(fra, &ipfr_tail);
+ ipfr_stats.ifs_expire++;
+ ipfr_inuse--;
+ }
+ RWLOCK_EXIT(&ipf_frag);
+
+ WRITE_ENTER(&ipf_ipidfrag);
+ for (fp = &ipfr_ipidlist; ((fra = *fp) != NULL); ) {
+ if (fra->ipfr_ttl > fr_ticks)
+ break;
+ fr_fragdelete(fra, &ipfr_ipidtail);
+ ipfr_stats.ifs_expire++;
+ ipfr_inuse--;
+ }
+ RWLOCK_EXIT(&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(&ipf_nat);
+ WRITE_ENTER(&ipf_natfrag);
+ for (fp = &ipfr_natlist; ((fra = *fp) != NULL); ) {
+ if (fra->ipfr_ttl > fr_ticks)
+ break;
+ nat = fra->ipfr_data;
+ if (nat != NULL) {
+ if (nat->nat_data == fra)
+ nat->nat_data = NULL;
+ }
+ fr_fragdelete(fra, &ipfr_nattail);
+ ipfr_stats.ifs_expire++;
+ ipfr_inuse--;
+ }
+ RWLOCK_EXIT(&ipf_natfrag);
+ RWLOCK_EXIT(&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__))
+# if defined(_KERNEL) && ((BSD >= 199103) || defined(__sgi))
+void fr_slowtimer __P((void *ptr))
+# else
+int fr_slowtimer()
+# endif
+{
+ READ_ENTER(&ipf_global);
+
+ fr_fragexpire();
+ fr_timeoutstate();
+ fr_natexpire();
+ fr_authexpire();
+ fr_ticks++;
+ if (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(&ipf_global);
+# if (BSD < 199103) || !defined(_KERNEL)
+ return 0;
+# endif
+}
+#endif /* !SOLARIS && !defined(__hpux) && !defined(__sgi) */
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