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/*
* (C)opyright 1993,1994,1995 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 0
#ifndef lint
static char sccsid[] = "@(#)ip_frag.c 1.11 3/24/96 (C) 1993-1995 Darren Reed";
static char rcsid[] = "$OpenBSD: ip_frag.c,v 1.5 1996/10/24 17:56:21 tholo Exp $";
#endif
#endif
#if !defined(_KERNEL) && !defined(KERNEL)
# include <string.h>
# include <stdlib.h>
#endif
#include <sys/errno.h>
#include <sys/types.h>
#if defined(_KERNEL) || defined(KERNEL)
#include <sys/systm.h>
#endif
#include <sys/param.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/uio.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#if !defined(__SVR4) && !defined(__svr4__)
# if defined(__OpenBSD__)
# include <sys/dirent.h>
# else
# include <sys/dir.h>
# endif
# include <sys/mbuf.h>
#else
# include <sys/byteorder.h>
# include <sys/dditypes.h>
# 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>
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/tcpip.h>
#include <netinet/ip_icmp.h>
#include <syslog.h>
#include "ip_fil_compat.h"
#include "ip_fil.h"
#include "ip_frag.h"
#include "ip_nat.h"
#include "ip_state.h"
ipfr_t *ipfr_heads[IPFT_SIZE];
ipfrstat_t ipfr_stats;
u_long ipfr_inuse = 0;
#ifdef _KERNEL
extern int ipfr_timer_id;
#endif
#if SOLARIS
# ifdef _KERNEL
extern kmutex_t ipf_frag;
# else
#define bcmp(a,b,c) memcmp(a,b,c)
#define bcopy(a,b,c) memmove(b,a,c)
# endif
#endif
# if BSD < 199306
int ipfr_slowtimer __P((void));
#else
void ipfr_slowtimer __P((void));
#endif
ipfrstat_t *
ipfr_fragstats()
{
ipfr_stats.ifs_table = ipfr_heads;
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.
*/
int
ipfr_newfrag(ip, fin, pass)
ip_t *ip;
fr_info_t *fin;
int pass;
{
ipfr_t **fp, *fr, frag;
u_int idx;
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;
idx *= 127;
idx %= IPFT_SIZE;
/*
* first, make sure it isn't already there...
*/
MUTEX_ENTER(&ipf_frag);
for (fp = &ipfr_heads[idx]; (fr = *fp); fp = &fr->ipfr_next)
if (!bcmp((char *)&frag.ipfr_src, (char *)&fr->ipfr_src,
IPFR_CMPSZ)) {
ipfr_stats.ifs_exists++;
MUTEX_EXIT(&ipf_frag);
return -1;
}
if (!(fr = (ipfr_t *)KMALLOC(sizeof(*fr)))) {
ipfr_stats.ifs_nomem++;
MUTEX_EXIT(&ipf_frag);
return -1;
}
if ((fr->ipfr_next = ipfr_heads[idx]))
ipfr_heads[idx]->ipfr_prev = fr;
fr->ipfr_prev = NULL;
ipfr_heads[idx] = fr;
bcopy((char *)&frag.ipfr_src, (char *)&fr->ipfr_src, IPFR_CMPSZ);
fr->ipfr_ttl = 120; /* 60 seconds */
fr->ipfr_pass = pass & ~(FR_LOGFIRST|FR_LOG);
fr->ipfr_off = (ip->ip_off & 0x1fff) + (fin->fin_dlen >> 3);
*fp = fr;
ipfr_stats.ifs_new++;
ipfr_inuse++;
MUTEX_EXIT(&ipf_frag);
return 0;
}
/*
* check the fragment cache to see if there is already a record of this packet
* with its filter result known.
*/
int
ipfr_knownfrag(ip, fin)
ip_t *ip;
fr_info_t *fin;
{
ipfr_t *f, frag;
u_int idx;
int ret;
/*
* For fragments, we record protocol, packet id, TOS and both IP#'s
* (these should all be the same for all fragments of a packet).
*/
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;
idx *= 127;
idx %= IPFT_SIZE;
MUTEX_ENTER(&ipf_frag);
for (f = ipfr_heads[idx]; f; f = f->ipfr_next)
if (!bcmp((char *)&frag.ipfr_src, (char *)&f->ipfr_src,
IPFR_CMPSZ)) {
u_short atoff, off;
if (f != ipfr_heads[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 = ipfr_heads[idx];
ipfr_heads[idx]->ipfr_prev = f;
f->ipfr_prev = NULL;
ipfr_heads[idx] = f;
}
ret = f->ipfr_pass;
off = ip->ip_off;
atoff = (off & 0x1fff) - (fin->fin_dlen >> 3);
/*
* If we've follwed the fragments, and this is the
* last (in order), shrink expiration time.
*/
if (atoff == f->ipfr_off) {
if (!(off & IP_MF))
f->ipfr_ttl = 1;
else
f->ipfr_off = off;
}
ipfr_stats.ifs_hits++;
MUTEX_EXIT(&ipf_frag);
return ret;
}
MUTEX_EXIT(&ipf_frag);
return 0;
}
/*
* Free memory in use by fragment state info. kept.
*/
void
ipfr_unload()
{
ipfr_t **fp, *fr;
int idx;
#if !SOLARIS && defined(_KERNEL)
int s;
#endif
MUTEX_ENTER(&ipf_frag);
SPLNET(s);
for (idx = IPFT_SIZE - 1; idx >= 0; idx--)
for (fp = &ipfr_heads[idx]; (fr = *fp); ) {
*fp = fr->ipfr_next;
KFREE(fp);
}
SPLX(s);
MUTEX_EXIT(&ipf_frag);
}
#ifdef _KERNEL
/*
* Slowly expire held state for fragments. Timeouts are set * in expectation
* of this being called twice per second.
*/
# if BSD < 199306
int
#else
void
#endif
ipfr_slowtimer()
{
ipfr_t **fp, *fr;
int s, idx;
MUTEX_ENTER(&ipf_frag);
SPLNET(s);
for (idx = IPFT_SIZE - 1; idx >= 0; idx--)
for (fp = &ipfr_heads[idx]; (fr = *fp); ) {
--fr->ipfr_ttl;
if (fr->ipfr_ttl == 0) {
if (fr->ipfr_prev)
fr->ipfr_prev->ipfr_next =
fr->ipfr_next;
if (fr->ipfr_next)
fr->ipfr_next->ipfr_prev =
fr->ipfr_prev;
*fp = fr->ipfr_next;
ipfr_stats.ifs_expire++;
ipfr_inuse--;
KFREE(fp);
} else
fp = &fr->ipfr_next;
}
SPLX(s);
#if SOLARIS
MUTEX_EXIT(&ipf_frag);
fr_timeoutstate();
ip_natexpire();
ipfr_timer_id = timeout(ipfr_slowtimer, NULL, HZ/2);
#else
fr_timeoutstate();
ip_natexpire();
ip_slowtimo();
#endif
# if BSD < 199306
return 0;
# endif
}
#endif /* defined(_KERNEL) */
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