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Diffstat (limited to 'sys/contrib/ipfilter/netinet/ip_frag.c')
-rw-r--r--sys/contrib/ipfilter/netinet/ip_frag.c555
1 files changed, 555 insertions, 0 deletions
diff --git a/sys/contrib/ipfilter/netinet/ip_frag.c b/sys/contrib/ipfilter/netinet/ip_frag.c
new file mode 100644
index 000000000000..556478d51d0b
--- /dev/null
+++ b/sys/contrib/ipfilter/netinet/ip_frag.c
@@ -0,0 +1,555 @@
+/*
+ * Copyright (C) 1993-2000 by Darren Reed.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that this notice is preserved and due credit is given
+ * to the original author and the contributors.
+ */
+#if !defined(lint)
+static const char sccsid[] = "@(#)ip_frag.c 1.11 3/24/96 (C) 1993-2000 Darren Reed";
+static const char rcsid[] = "@(#)$Id: ip_frag.c,v 2.10.2.7 2000/11/27 10:26:56 darrenr Exp $";
+#endif
+
+#if defined(KERNEL) && !defined(_KERNEL)
+# define _KERNEL
+#endif
+
+#include <sys/errno.h>
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/file.h>
+#if !defined(_KERNEL) && !defined(KERNEL)
+# include <stdio.h>
+# include <string.h>
+# include <stdlib.h>
+#endif
+#if (defined(KERNEL) || defined(_KERNEL)) && (__FreeBSD_version >= 220000)
+# include <sys/filio.h>
+# include <sys/fcntl.h>
+#else
+# include <sys/ioctl.h>
+#endif
+#include <sys/uio.h>
+#ifndef linux
+# include <sys/protosw.h>
+#endif
+#include <sys/socket.h>
+#if defined(_KERNEL) && !defined(linux)
+# include <sys/systm.h>
+#endif
+#if !defined(__SVR4) && !defined(__svr4__)
+# if defined(_KERNEL) && !defined(__sgi)
+# include <sys/kernel.h>
+# endif
+# ifndef linux
+# include <sys/mbuf.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>
+#ifndef 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_proxy.h"
+#include "netinet/ip_nat.h"
+#include "netinet/ip_frag.h"
+#include "netinet/ip_state.h"
+#include "netinet/ip_auth.h"
+#if (__FreeBSD_version >= 300000)
+# include <sys/malloc.h>
+# if (defined(KERNEL) || defined(_KERNEL))
+# ifndef IPFILTER_LKM
+# include <sys/libkern.h>
+# include <sys/systm.h>
+# endif
+extern struct callout_handle ipfr_slowtimer_ch;
+# endif
+#endif
+#if defined(__NetBSD__) && (__NetBSD_Version__ >= 104230000)
+# include <sys/callout.h>
+extern struct callout ipfr_slowtimer_ch;
+#endif
+
+
+static ipfr_t *ipfr_heads[IPFT_SIZE];
+static ipfr_t *ipfr_nattab[IPFT_SIZE];
+static ipfrstat_t ipfr_stats;
+static int ipfr_inuse = 0;
+
+int fr_ipfrttl = 120; /* 60 seconds */
+int fr_frag_lock = 0;
+
+#ifdef _KERNEL
+# if SOLARIS2 >= 7
+extern timeout_id_t ipfr_timer_id;
+# else
+extern int ipfr_timer_id;
+# endif
+#endif
+#if (SOLARIS || defined(__sgi)) && defined(_KERNEL)
+extern KRWLOCK_T ipf_frag, ipf_natfrag, ipf_nat, ipf_mutex;
+# if SOLARIS
+extern KRWLOCK_T ipf_solaris;
+# else
+KRWLOCK_T ipf_solaris;
+# endif
+extern kmutex_t ipf_rw;
+#endif
+
+
+static ipfr_t *ipfr_new __P((ip_t *, fr_info_t *, u_int, ipfr_t **));
+static ipfr_t *ipfr_lookup __P((ip_t *, fr_info_t *, ipfr_t **));
+static void ipfr_delete __P((ipfr_t *));
+
+
+ipfrstat_t *ipfr_fragstats()
+{
+ ipfr_stats.ifs_table = ipfr_heads;
+ ipfr_stats.ifs_nattab = ipfr_nattab;
+ ipfr_stats.ifs_inuse = ipfr_inuse;
+ return &ipfr_stats;
+}
+
+
+/*
+ * 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_new(ip, fin, pass, table)
+ip_t *ip;
+fr_info_t *fin;
+u_int pass;
+ipfr_t *table[];
+{
+ ipfr_t **fp, *fra, frag;
+ u_int idx;
+
+ if (ipfr_inuse >= IPFT_SIZE)
+ 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;
+
+ /*
+ * first, make sure it isn't already there...
+ */
+ for (fp = &table[idx]; (fra = *fp); fp = &fra->ipfr_next)
+ if (!bcmp((char *)&frag.ipfr_src, (char *)&fra->ipfr_src,
+ IPFR_CMPSZ)) {
+ ATOMIC_INCL(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) {
+ ATOMIC_INCL(ipfr_stats.ifs_nomem);
+ return NULL;
+ }
+
+ if ((fra->ipfr_rule = fin->fin_fr) != NULL) {
+ ATOMIC_INC32(fin->fin_fr->fr_ref);
+ }
+
+
+ /*
+ * Instert 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 and mask out logging from "pass"
+ */
+ if ((fra->ipfr_next = table[idx]))
+ table[idx]->ipfr_prev = fra;
+ fra->ipfr_prev = NULL;
+ fra->ipfr_data = NULL;
+ table[idx] = fra;
+ bcopy((char *)&frag.ipfr_src, (char *)&fra->ipfr_src, IPFR_CMPSZ);
+ fra->ipfr_ttl = fr_ipfrttl;
+ /*
+ * Compute the offset of the expected start of the next packet.
+ */
+ fra->ipfr_off = (ip->ip_off & IP_OFFMASK) + (fin->fin_dlen >> 3);
+ ATOMIC_INCL(ipfr_stats.ifs_new);
+ ATOMIC_INC32(ipfr_inuse);
+ return fra;
+}
+
+
+int ipfr_newfrag(ip, fin, pass)
+ip_t *ip;
+fr_info_t *fin;
+u_int pass;
+{
+ ipfr_t *ipf;
+
+ if ((ip->ip_v != 4) || (fr_frag_lock))
+ return -1;
+ WRITE_ENTER(&ipf_frag);
+ ipf = ipfr_new(ip, fin, pass, ipfr_heads);
+ RWLOCK_EXIT(&ipf_frag);
+ return ipf ? 0 : -1;
+}
+
+
+int ipfr_nat_newfrag(ip, fin, pass, nat)
+ip_t *ip;
+fr_info_t *fin;
+u_int pass;
+nat_t *nat;
+{
+ ipfr_t *ipf;
+
+ if ((ip->ip_v != 4) || (fr_frag_lock))
+ return -1;
+ WRITE_ENTER(&ipf_natfrag);
+ ipf = ipfr_new(ip, fin, pass, ipfr_nattab);
+ if (ipf != NULL) {
+ ipf->ipfr_data = nat;
+ nat->nat_data = ipf;
+ }
+ RWLOCK_EXIT(&ipf_natfrag);
+ return ipf ? 0 : -1;
+}
+
+
+/*
+ * check the fragment cache to see if there is already a record of this packet
+ * with its filter result known.
+ */
+static ipfr_t *ipfr_lookup(ip, fin, table)
+ip_t *ip;
+fr_info_t *fin;
+ipfr_t *table[];
+{
+ ipfr_t *f, 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.
+ */
+ 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;
+
+ /*
+ * check the table, careful to only compare the right amount of data
+ */
+ for (f = table[idx]; f; f = f->ipfr_next)
+ if (!bcmp((char *)&frag.ipfr_src, (char *)&f->ipfr_src,
+ IPFR_CMPSZ)) {
+ u_short atoff, off;
+
+ if (f != table[idx]) {
+ /*
+ * move fragment info. to the top of the list
+ * to speed up searches.
+ */
+ if ((f->ipfr_prev->ipfr_next = f->ipfr_next))
+ f->ipfr_next->ipfr_prev = f->ipfr_prev;
+ f->ipfr_next = table[idx];
+ table[idx]->ipfr_prev = f;
+ f->ipfr_prev = NULL;
+ table[idx] = f;
+ }
+ off = ip->ip_off & IP_OFFMASK;
+ atoff = off + (fin->fin_dlen >> 3);
+ /*
+ * 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 = 1;
+ else
+ f->ipfr_off = atoff;
+ }
+ ATOMIC_INCL(ipfr_stats.ifs_hits);
+ return f;
+ }
+ return NULL;
+}
+
+
+/*
+ * functional interface for NAT lookups of the NAT fragment cache
+ */
+nat_t *ipfr_nat_knownfrag(ip, fin)
+ip_t *ip;
+fr_info_t *fin;
+{
+ nat_t *nat;
+ ipfr_t *ipf;
+
+ if ((ip->ip_v != 4) || (fr_frag_lock))
+ return NULL;
+ READ_ENTER(&ipf_natfrag);
+ ipf = ipfr_lookup(ip, fin, ipfr_nattab);
+ if (ipf != NULL) {
+ nat = ipf->ipfr_data;
+ /*
+ * This is the last fragment for this packet.
+ */
+ if ((ipf->ipfr_ttl == 1) && (nat != NULL)) {
+ nat->nat_data = NULL;
+ ipf->ipfr_data = NULL;
+ }
+ } else
+ nat = NULL;
+ RWLOCK_EXIT(&ipf_natfrag);
+ return nat;
+}
+
+
+/*
+ * functional interface for normal lookups of the fragment cache
+ */
+frentry_t *ipfr_knownfrag(ip, fin)
+ip_t *ip;
+fr_info_t *fin;
+{
+ frentry_t *fr = NULL;
+ ipfr_t *fra;
+
+ if ((ip->ip_v != 4) || (fr_frag_lock))
+ return NULL;
+ READ_ENTER(&ipf_frag);
+ fra = ipfr_lookup(ip, fin, ipfr_heads);
+ if (fra != NULL)
+ fr = fra->ipfr_rule;
+ RWLOCK_EXIT(&ipf_frag);
+ return fr;
+}
+
+
+/*
+ * forget any references to this external object.
+ */
+void ipfr_forget(nat)
+void *nat;
+{
+ ipfr_t *fr;
+ int idx;
+
+ WRITE_ENTER(&ipf_natfrag);
+ for (idx = IPFT_SIZE - 1; idx >= 0; idx--)
+ for (fr = ipfr_heads[idx]; fr; fr = fr->ipfr_next)
+ if (fr->ipfr_data == nat)
+ fr->ipfr_data = NULL;
+
+ RWLOCK_EXIT(&ipf_natfrag);
+}
+
+
+static void ipfr_delete(fra)
+ipfr_t *fra;
+{
+ frentry_t *fr;
+
+ fr = fra->ipfr_rule;
+ if (fr != NULL) {
+ ATOMIC_DEC32(fr->fr_ref);
+ if (fr->fr_ref == 0)
+ KFREE(fr);
+ }
+ if (fra->ipfr_prev)
+ fra->ipfr_prev->ipfr_next = fra->ipfr_next;
+ if (fra->ipfr_next)
+ fra->ipfr_next->ipfr_prev = fra->ipfr_prev;
+ KFREE(fra);
+}
+
+
+/*
+ * Free memory in use by fragment state info. kept.
+ */
+void ipfr_unload()
+{
+ ipfr_t **fp, *fra;
+ nat_t *nat;
+ int idx;
+
+ WRITE_ENTER(&ipf_frag);
+ for (idx = IPFT_SIZE - 1; idx >= 0; idx--)
+ for (fp = &ipfr_heads[idx]; (fra = *fp); ) {
+ *fp = fra->ipfr_next;
+ ipfr_delete(fra);
+ }
+ RWLOCK_EXIT(&ipf_frag);
+
+ WRITE_ENTER(&ipf_nat);
+ WRITE_ENTER(&ipf_natfrag);
+ for (idx = IPFT_SIZE - 1; idx >= 0; idx--)
+ for (fp = &ipfr_nattab[idx]; (fra = *fp); ) {
+ *fp = fra->ipfr_next;
+ nat = fra->ipfr_data;
+ if (nat != NULL) {
+ if (nat->nat_data == fra)
+ nat->nat_data = NULL;
+ }
+ ipfr_delete(fra);
+ }
+ RWLOCK_EXIT(&ipf_natfrag);
+ RWLOCK_EXIT(&ipf_nat);
+}
+
+
+#ifdef _KERNEL
+void ipfr_fragexpire()
+{
+ ipfr_t **fp, *fra;
+ nat_t *nat;
+ int idx;
+#if defined(_KERNEL)
+# if !SOLARIS
+ int s;
+# endif
+#endif
+
+ if (fr_frag_lock)
+ return;
+
+ SPL_NET(s);
+ WRITE_ENTER(&ipf_frag);
+
+ /*
+ * Go through the entire table, looking for entries to expire,
+ * decreasing the ttl by one for each entry. If it reaches 0,
+ * remove it from the chain and free it.
+ */
+ for (idx = IPFT_SIZE - 1; idx >= 0; idx--)
+ for (fp = &ipfr_heads[idx]; (fra = *fp); ) {
+ --fra->ipfr_ttl;
+ if (fra->ipfr_ttl == 0) {
+ *fp = fra->ipfr_next;
+ ipfr_delete(fra);
+ ATOMIC_INCL(ipfr_stats.ifs_expire);
+ ATOMIC_DEC32(ipfr_inuse);
+ } else
+ fp = &fra->ipfr_next;
+ }
+ RWLOCK_EXIT(&ipf_frag);
+
+ /*
+ * 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 (idx = IPFT_SIZE - 1; idx >= 0; idx--)
+ for (fp = &ipfr_nattab[idx]; (fra = *fp); ) {
+ --fra->ipfr_ttl;
+ if (fra->ipfr_ttl == 0) {
+ ATOMIC_INCL(ipfr_stats.ifs_expire);
+ ATOMIC_DEC32(ipfr_inuse);
+ nat = fra->ipfr_data;
+ if (nat != NULL) {
+ if (nat->nat_data == fra)
+ nat->nat_data = NULL;
+ }
+ *fp = fra->ipfr_next;
+ ipfr_delete(fra);
+ } else
+ fp = &fra->ipfr_next;
+ }
+ RWLOCK_EXIT(&ipf_natfrag);
+ RWLOCK_EXIT(&ipf_nat);
+ SPL_X(s);
+}
+
+
+/*
+ * Slowly expire held state for fragments. Timeouts are set * in expectation
+ * of this being called twice per second.
+ */
+# if (BSD >= 199306) || SOLARIS || defined(__sgi)
+# if defined(SOLARIS2) && (SOLARIS2 < 7)
+void ipfr_slowtimer()
+# else
+void ipfr_slowtimer __P((void *ptr))
+# endif
+# else
+int ipfr_slowtimer()
+# endif
+{
+#if defined(_KERNEL) && SOLARIS
+ extern int fr_running;
+
+ if (fr_running <= 0)
+ return;
+#endif
+
+ READ_ENTER(&ipf_solaris);
+#ifdef __sgi
+ ipfilter_sgi_intfsync();
+#endif
+
+ ipfr_fragexpire();
+ fr_timeoutstate();
+ ip_natexpire();
+ fr_authexpire();
+# if SOLARIS
+ ipfr_timer_id = timeout(ipfr_slowtimer, NULL, drv_usectohz(500000));
+ RWLOCK_EXIT(&ipf_solaris);
+# else
+# if defined(__NetBSD__) && (__NetBSD_Version__ >= 104240000)
+ callout_reset(&ipfr_slowtimer_ch, hz / 2, ipfr_slowtimer, NULL);
+# else
+# if (__FreeBSD_version >= 300000)
+ ipfr_slowtimer_ch = timeout(ipfr_slowtimer, NULL, hz/2);
+# else
+ timeout(ipfr_slowtimer, NULL, hz/2);
+# endif
+# if (BSD < 199306) && !defined(__sgi)
+ return 0;
+# endif /* FreeBSD */
+# endif /* NetBSD */
+# endif /* SOLARIS */
+}
+#endif /* defined(_KERNEL) */
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-25 07:04:26 +0000