2005-04-16 22:20:36 +00:00
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/*
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* Packet matching code.
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*
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* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
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* Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* 19 Jan 2002 Harald Welte <laforge@gnumonks.org>
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* - increase module usage count as soon as we have rules inside
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* a table
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*/
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#include <linux/config.h>
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#include <linux/cache.h>
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#include <linux/skbuff.h>
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#include <linux/kmod.h>
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#include <linux/vmalloc.h>
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#include <linux/netdevice.h>
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#include <linux/module.h>
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <linux/icmp.h>
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#include <net/ip.h>
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#include <asm/uaccess.h>
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#include <asm/semaphore.h>
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#include <linux/proc_fs.h>
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#include <linux/err.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
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MODULE_DESCRIPTION("IPv4 packet filter");
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/*#define DEBUG_IP_FIREWALL*/
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/*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
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/*#define DEBUG_IP_FIREWALL_USER*/
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#ifdef DEBUG_IP_FIREWALL
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#define dprintf(format, args...) printk(format , ## args)
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#else
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#define dprintf(format, args...)
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#endif
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#ifdef DEBUG_IP_FIREWALL_USER
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#define duprintf(format, args...) printk(format , ## args)
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#else
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#define duprintf(format, args...)
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#endif
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#ifdef CONFIG_NETFILTER_DEBUG
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#define IP_NF_ASSERT(x) \
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do { \
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if (!(x)) \
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printk("IP_NF_ASSERT: %s:%s:%u\n", \
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__FUNCTION__, __FILE__, __LINE__); \
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} while(0)
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#else
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#define IP_NF_ASSERT(x)
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#endif
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#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
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static DECLARE_MUTEX(ipt_mutex);
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/* Must have mutex */
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#define ASSERT_READ_LOCK(x) IP_NF_ASSERT(down_trylock(&ipt_mutex) != 0)
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#define ASSERT_WRITE_LOCK(x) IP_NF_ASSERT(down_trylock(&ipt_mutex) != 0)
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#include <linux/netfilter_ipv4/listhelp.h>
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#if 0
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/* All the better to debug you with... */
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#define static
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#define inline
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#endif
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/*
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We keep a set of rules for each CPU, so we can avoid write-locking
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them in the softirq when updating the counters and therefore
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only need to read-lock in the softirq; doing a write_lock_bh() in user
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context stops packets coming through and allows user context to read
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the counters or update the rules.
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To be cache friendly on SMP, we arrange them like so:
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[ n-entries ]
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... cache-align padding ...
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[ n-entries ]
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Hence the start of any table is given by get_table() below. */
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/* The table itself */
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struct ipt_table_info
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{
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/* Size per table */
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unsigned int size;
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/* Number of entries: FIXME. --RR */
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unsigned int number;
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/* Initial number of entries. Needed for module usage count */
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unsigned int initial_entries;
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/* Entry points and underflows */
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unsigned int hook_entry[NF_IP_NUMHOOKS];
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unsigned int underflow[NF_IP_NUMHOOKS];
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/* ipt_entry tables: one per CPU */
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char entries[0] ____cacheline_aligned;
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};
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static LIST_HEAD(ipt_target);
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static LIST_HEAD(ipt_match);
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static LIST_HEAD(ipt_tables);
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#define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
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#ifdef CONFIG_SMP
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#define TABLE_OFFSET(t,p) (SMP_ALIGN((t)->size)*(p))
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#else
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#define TABLE_OFFSET(t,p) 0
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#endif
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#if 0
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#define down(x) do { printk("DOWN:%u:" #x "\n", __LINE__); down(x); } while(0)
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#define down_interruptible(x) ({ int __r; printk("DOWNi:%u:" #x "\n", __LINE__); __r = down_interruptible(x); if (__r != 0) printk("ABORT-DOWNi:%u\n", __LINE__); __r; })
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#define up(x) do { printk("UP:%u:" #x "\n", __LINE__); up(x); } while(0)
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#endif
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/* Returns whether matches rule or not. */
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static inline int
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ip_packet_match(const struct iphdr *ip,
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const char *indev,
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const char *outdev,
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const struct ipt_ip *ipinfo,
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int isfrag)
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{
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size_t i;
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unsigned long ret;
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#define FWINV(bool,invflg) ((bool) ^ !!(ipinfo->invflags & invflg))
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if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
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IPT_INV_SRCIP)
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|| FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
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IPT_INV_DSTIP)) {
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dprintf("Source or dest mismatch.\n");
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dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
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NIPQUAD(ip->saddr),
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NIPQUAD(ipinfo->smsk.s_addr),
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NIPQUAD(ipinfo->src.s_addr),
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ipinfo->invflags & IPT_INV_SRCIP ? " (INV)" : "");
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dprintf("DST: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
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NIPQUAD(ip->daddr),
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NIPQUAD(ipinfo->dmsk.s_addr),
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NIPQUAD(ipinfo->dst.s_addr),
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ipinfo->invflags & IPT_INV_DSTIP ? " (INV)" : "");
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return 0;
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}
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/* Look for ifname matches; this should unroll nicely. */
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for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
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ret |= (((const unsigned long *)indev)[i]
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^ ((const unsigned long *)ipinfo->iniface)[i])
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& ((const unsigned long *)ipinfo->iniface_mask)[i];
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}
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if (FWINV(ret != 0, IPT_INV_VIA_IN)) {
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dprintf("VIA in mismatch (%s vs %s).%s\n",
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indev, ipinfo->iniface,
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ipinfo->invflags&IPT_INV_VIA_IN ?" (INV)":"");
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return 0;
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}
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for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
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ret |= (((const unsigned long *)outdev)[i]
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^ ((const unsigned long *)ipinfo->outiface)[i])
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& ((const unsigned long *)ipinfo->outiface_mask)[i];
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}
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if (FWINV(ret != 0, IPT_INV_VIA_OUT)) {
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dprintf("VIA out mismatch (%s vs %s).%s\n",
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outdev, ipinfo->outiface,
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ipinfo->invflags&IPT_INV_VIA_OUT ?" (INV)":"");
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return 0;
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}
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/* Check specific protocol */
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if (ipinfo->proto
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&& FWINV(ip->protocol != ipinfo->proto, IPT_INV_PROTO)) {
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dprintf("Packet protocol %hi does not match %hi.%s\n",
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ip->protocol, ipinfo->proto,
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ipinfo->invflags&IPT_INV_PROTO ? " (INV)":"");
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return 0;
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}
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/* If we have a fragment rule but the packet is not a fragment
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* then we return zero */
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if (FWINV((ipinfo->flags&IPT_F_FRAG) && !isfrag, IPT_INV_FRAG)) {
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dprintf("Fragment rule but not fragment.%s\n",
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ipinfo->invflags & IPT_INV_FRAG ? " (INV)" : "");
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return 0;
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}
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return 1;
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}
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static inline int
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ip_checkentry(const struct ipt_ip *ip)
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{
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if (ip->flags & ~IPT_F_MASK) {
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duprintf("Unknown flag bits set: %08X\n",
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ip->flags & ~IPT_F_MASK);
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return 0;
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}
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if (ip->invflags & ~IPT_INV_MASK) {
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duprintf("Unknown invflag bits set: %08X\n",
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ip->invflags & ~IPT_INV_MASK);
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return 0;
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}
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return 1;
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}
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static unsigned int
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ipt_error(struct sk_buff **pskb,
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const struct net_device *in,
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const struct net_device *out,
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unsigned int hooknum,
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const void *targinfo,
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void *userinfo)
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{
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if (net_ratelimit())
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printk("ip_tables: error: `%s'\n", (char *)targinfo);
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return NF_DROP;
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}
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static inline
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int do_match(struct ipt_entry_match *m,
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const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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int offset,
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int *hotdrop)
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{
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/* Stop iteration if it doesn't match */
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if (!m->u.kernel.match->match(skb, in, out, m->data, offset, hotdrop))
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return 1;
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else
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return 0;
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}
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static inline struct ipt_entry *
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get_entry(void *base, unsigned int offset)
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{
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return (struct ipt_entry *)(base + offset);
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}
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/* Returns one of the generic firewall policies, like NF_ACCEPT. */
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unsigned int
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ipt_do_table(struct sk_buff **pskb,
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unsigned int hook,
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const struct net_device *in,
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const struct net_device *out,
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struct ipt_table *table,
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void *userdata)
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{
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static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
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u_int16_t offset;
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struct iphdr *ip;
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u_int16_t datalen;
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int hotdrop = 0;
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/* Initializing verdict to NF_DROP keeps gcc happy. */
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unsigned int verdict = NF_DROP;
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const char *indev, *outdev;
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void *table_base;
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struct ipt_entry *e, *back;
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/* Initialization */
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ip = (*pskb)->nh.iph;
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datalen = (*pskb)->len - ip->ihl * 4;
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indev = in ? in->name : nulldevname;
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outdev = out ? out->name : nulldevname;
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/* We handle fragments by dealing with the first fragment as
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* if it was a normal packet. All other fragments are treated
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* normally, except that they will NEVER match rules that ask
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* things we don't know, ie. tcp syn flag or ports). If the
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* rule is also a fragment-specific rule, non-fragments won't
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* match it. */
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offset = ntohs(ip->frag_off) & IP_OFFSET;
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read_lock_bh(&table->lock);
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IP_NF_ASSERT(table->valid_hooks & (1 << hook));
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table_base = (void *)table->private->entries
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+ TABLE_OFFSET(table->private, smp_processor_id());
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e = get_entry(table_base, table->private->hook_entry[hook]);
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#ifdef CONFIG_NETFILTER_DEBUG
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/* Check noone else using our table */
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if (((struct ipt_entry *)table_base)->comefrom != 0xdead57ac
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&& ((struct ipt_entry *)table_base)->comefrom != 0xeeeeeeec) {
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printk("ASSERT: CPU #%u, %s comefrom(%p) = %X\n",
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smp_processor_id(),
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table->name,
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&((struct ipt_entry *)table_base)->comefrom,
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((struct ipt_entry *)table_base)->comefrom);
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}
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((struct ipt_entry *)table_base)->comefrom = 0x57acc001;
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#endif
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/* For return from builtin chain */
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back = get_entry(table_base, table->private->underflow[hook]);
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do {
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IP_NF_ASSERT(e);
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IP_NF_ASSERT(back);
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if (ip_packet_match(ip, indev, outdev, &e->ip, offset)) {
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struct ipt_entry_target *t;
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if (IPT_MATCH_ITERATE(e, do_match,
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*pskb, in, out,
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offset, &hotdrop) != 0)
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goto no_match;
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ADD_COUNTER(e->counters, ntohs(ip->tot_len), 1);
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t = ipt_get_target(e);
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IP_NF_ASSERT(t->u.kernel.target);
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/* Standard target? */
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if (!t->u.kernel.target->target) {
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int v;
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v = ((struct ipt_standard_target *)t)->verdict;
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if (v < 0) {
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/* Pop from stack? */
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if (v != IPT_RETURN) {
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verdict = (unsigned)(-v) - 1;
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break;
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}
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e = back;
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back = get_entry(table_base,
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back->comefrom);
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continue;
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}
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2005-08-22 06:31:43 +00:00
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if (table_base + v != (void *)e + e->next_offset
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&& !(e->ip.flags & IPT_F_GOTO)) {
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2005-04-16 22:20:36 +00:00
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/* Save old back ptr in next entry */
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struct ipt_entry *next
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= (void *)e + e->next_offset;
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next->comefrom
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= (void *)back - table_base;
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/* set back pointer to next entry */
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back = next;
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}
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e = get_entry(table_base, v);
|
|
|
|
} else {
|
|
|
|
/* Targets which reenter must return
|
|
|
|
abs. verdicts */
|
|
|
|
#ifdef CONFIG_NETFILTER_DEBUG
|
|
|
|
((struct ipt_entry *)table_base)->comefrom
|
|
|
|
= 0xeeeeeeec;
|
|
|
|
#endif
|
|
|
|
verdict = t->u.kernel.target->target(pskb,
|
|
|
|
in, out,
|
|
|
|
hook,
|
|
|
|
t->data,
|
|
|
|
userdata);
|
|
|
|
|
|
|
|
#ifdef CONFIG_NETFILTER_DEBUG
|
|
|
|
if (((struct ipt_entry *)table_base)->comefrom
|
|
|
|
!= 0xeeeeeeec
|
|
|
|
&& verdict == IPT_CONTINUE) {
|
|
|
|
printk("Target %s reentered!\n",
|
|
|
|
t->u.kernel.target->name);
|
|
|
|
verdict = NF_DROP;
|
|
|
|
}
|
|
|
|
((struct ipt_entry *)table_base)->comefrom
|
|
|
|
= 0x57acc001;
|
|
|
|
#endif
|
|
|
|
/* Target might have changed stuff. */
|
|
|
|
ip = (*pskb)->nh.iph;
|
|
|
|
datalen = (*pskb)->len - ip->ihl * 4;
|
|
|
|
|
|
|
|
if (verdict == IPT_CONTINUE)
|
|
|
|
e = (void *)e + e->next_offset;
|
|
|
|
else
|
|
|
|
/* Verdict */
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
|
|
|
|
no_match:
|
|
|
|
e = (void *)e + e->next_offset;
|
|
|
|
}
|
|
|
|
} while (!hotdrop);
|
|
|
|
|
|
|
|
#ifdef CONFIG_NETFILTER_DEBUG
|
|
|
|
((struct ipt_entry *)table_base)->comefrom = 0xdead57ac;
|
|
|
|
#endif
|
|
|
|
read_unlock_bh(&table->lock);
|
|
|
|
|
|
|
|
#ifdef DEBUG_ALLOW_ALL
|
|
|
|
return NF_ACCEPT;
|
|
|
|
#else
|
|
|
|
if (hotdrop)
|
|
|
|
return NF_DROP;
|
|
|
|
else return verdict;
|
|
|
|
#endif
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* These are weird, but module loading must not be done with mutex
|
|
|
|
* held (since they will register), and we have to have a single
|
|
|
|
* function to use try_then_request_module().
|
|
|
|
*/
|
|
|
|
|
|
|
|
/* Find table by name, grabs mutex & ref. Returns ERR_PTR() on error. */
|
|
|
|
static inline struct ipt_table *find_table_lock(const char *name)
|
|
|
|
{
|
|
|
|
struct ipt_table *t;
|
|
|
|
|
|
|
|
if (down_interruptible(&ipt_mutex) != 0)
|
|
|
|
return ERR_PTR(-EINTR);
|
|
|
|
|
|
|
|
list_for_each_entry(t, &ipt_tables, list)
|
|
|
|
if (strcmp(t->name, name) == 0 && try_module_get(t->me))
|
|
|
|
return t;
|
|
|
|
up(&ipt_mutex);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Find match, grabs ref. Returns ERR_PTR() on error. */
|
|
|
|
static inline struct ipt_match *find_match(const char *name, u8 revision)
|
|
|
|
{
|
|
|
|
struct ipt_match *m;
|
|
|
|
int err = 0;
|
|
|
|
|
|
|
|
if (down_interruptible(&ipt_mutex) != 0)
|
|
|
|
return ERR_PTR(-EINTR);
|
|
|
|
|
|
|
|
list_for_each_entry(m, &ipt_match, list) {
|
|
|
|
if (strcmp(m->name, name) == 0) {
|
|
|
|
if (m->revision == revision) {
|
|
|
|
if (try_module_get(m->me)) {
|
|
|
|
up(&ipt_mutex);
|
|
|
|
return m;
|
|
|
|
}
|
|
|
|
} else
|
|
|
|
err = -EPROTOTYPE; /* Found something. */
|
|
|
|
}
|
|
|
|
}
|
|
|
|
up(&ipt_mutex);
|
|
|
|
return ERR_PTR(err);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Find target, grabs ref. Returns ERR_PTR() on error. */
|
|
|
|
static inline struct ipt_target *find_target(const char *name, u8 revision)
|
|
|
|
{
|
|
|
|
struct ipt_target *t;
|
|
|
|
int err = 0;
|
|
|
|
|
|
|
|
if (down_interruptible(&ipt_mutex) != 0)
|
|
|
|
return ERR_PTR(-EINTR);
|
|
|
|
|
|
|
|
list_for_each_entry(t, &ipt_target, list) {
|
|
|
|
if (strcmp(t->name, name) == 0) {
|
|
|
|
if (t->revision == revision) {
|
|
|
|
if (try_module_get(t->me)) {
|
|
|
|
up(&ipt_mutex);
|
|
|
|
return t;
|
|
|
|
}
|
|
|
|
} else
|
|
|
|
err = -EPROTOTYPE; /* Found something. */
|
|
|
|
}
|
|
|
|
}
|
|
|
|
up(&ipt_mutex);
|
|
|
|
return ERR_PTR(err);
|
|
|
|
}
|
|
|
|
|
|
|
|
struct ipt_target *ipt_find_target(const char *name, u8 revision)
|
|
|
|
{
|
|
|
|
struct ipt_target *target;
|
|
|
|
|
|
|
|
target = try_then_request_module(find_target(name, revision),
|
|
|
|
"ipt_%s", name);
|
|
|
|
if (IS_ERR(target) || !target)
|
|
|
|
return NULL;
|
|
|
|
return target;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int match_revfn(const char *name, u8 revision, int *bestp)
|
|
|
|
{
|
|
|
|
struct ipt_match *m;
|
|
|
|
int have_rev = 0;
|
|
|
|
|
|
|
|
list_for_each_entry(m, &ipt_match, list) {
|
|
|
|
if (strcmp(m->name, name) == 0) {
|
|
|
|
if (m->revision > *bestp)
|
|
|
|
*bestp = m->revision;
|
|
|
|
if (m->revision == revision)
|
|
|
|
have_rev = 1;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return have_rev;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int target_revfn(const char *name, u8 revision, int *bestp)
|
|
|
|
{
|
|
|
|
struct ipt_target *t;
|
|
|
|
int have_rev = 0;
|
|
|
|
|
|
|
|
list_for_each_entry(t, &ipt_target, list) {
|
|
|
|
if (strcmp(t->name, name) == 0) {
|
|
|
|
if (t->revision > *bestp)
|
|
|
|
*bestp = t->revision;
|
|
|
|
if (t->revision == revision)
|
|
|
|
have_rev = 1;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return have_rev;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Returns true or false (if no such extension at all) */
|
|
|
|
static inline int find_revision(const char *name, u8 revision,
|
|
|
|
int (*revfn)(const char *, u8, int *),
|
|
|
|
int *err)
|
|
|
|
{
|
|
|
|
int have_rev, best = -1;
|
|
|
|
|
|
|
|
if (down_interruptible(&ipt_mutex) != 0) {
|
|
|
|
*err = -EINTR;
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
have_rev = revfn(name, revision, &best);
|
|
|
|
up(&ipt_mutex);
|
|
|
|
|
|
|
|
/* Nothing at all? Return 0 to try loading module. */
|
|
|
|
if (best == -1) {
|
|
|
|
*err = -ENOENT;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
*err = best;
|
|
|
|
if (!have_rev)
|
|
|
|
*err = -EPROTONOSUPPORT;
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/* All zeroes == unconditional rule. */
|
|
|
|
static inline int
|
|
|
|
unconditional(const struct ipt_ip *ip)
|
|
|
|
{
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
for (i = 0; i < sizeof(*ip)/sizeof(__u32); i++)
|
|
|
|
if (((__u32 *)ip)[i])
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Figures out from what hook each rule can be called: returns 0 if
|
|
|
|
there are loops. Puts hook bitmask in comefrom. */
|
|
|
|
static int
|
|
|
|
mark_source_chains(struct ipt_table_info *newinfo, unsigned int valid_hooks)
|
|
|
|
{
|
|
|
|
unsigned int hook;
|
|
|
|
|
|
|
|
/* No recursion; use packet counter to save back ptrs (reset
|
|
|
|
to 0 as we leave), and comefrom to save source hook bitmask */
|
|
|
|
for (hook = 0; hook < NF_IP_NUMHOOKS; hook++) {
|
|
|
|
unsigned int pos = newinfo->hook_entry[hook];
|
|
|
|
struct ipt_entry *e
|
|
|
|
= (struct ipt_entry *)(newinfo->entries + pos);
|
|
|
|
|
|
|
|
if (!(valid_hooks & (1 << hook)))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
/* Set initial back pointer. */
|
|
|
|
e->counters.pcnt = pos;
|
|
|
|
|
|
|
|
for (;;) {
|
|
|
|
struct ipt_standard_target *t
|
|
|
|
= (void *)ipt_get_target(e);
|
|
|
|
|
|
|
|
if (e->comefrom & (1 << NF_IP_NUMHOOKS)) {
|
|
|
|
printk("iptables: loop hook %u pos %u %08X.\n",
|
|
|
|
hook, pos, e->comefrom);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
e->comefrom
|
|
|
|
|= ((1 << hook) | (1 << NF_IP_NUMHOOKS));
|
|
|
|
|
|
|
|
/* Unconditional return/END. */
|
|
|
|
if (e->target_offset == sizeof(struct ipt_entry)
|
|
|
|
&& (strcmp(t->target.u.user.name,
|
|
|
|
IPT_STANDARD_TARGET) == 0)
|
|
|
|
&& t->verdict < 0
|
|
|
|
&& unconditional(&e->ip)) {
|
|
|
|
unsigned int oldpos, size;
|
|
|
|
|
|
|
|
/* Return: backtrack through the last
|
|
|
|
big jump. */
|
|
|
|
do {
|
|
|
|
e->comefrom ^= (1<<NF_IP_NUMHOOKS);
|
|
|
|
#ifdef DEBUG_IP_FIREWALL_USER
|
|
|
|
if (e->comefrom
|
|
|
|
& (1 << NF_IP_NUMHOOKS)) {
|
|
|
|
duprintf("Back unset "
|
|
|
|
"on hook %u "
|
|
|
|
"rule %u\n",
|
|
|
|
hook, pos);
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
oldpos = pos;
|
|
|
|
pos = e->counters.pcnt;
|
|
|
|
e->counters.pcnt = 0;
|
|
|
|
|
|
|
|
/* We're at the start. */
|
|
|
|
if (pos == oldpos)
|
|
|
|
goto next;
|
|
|
|
|
|
|
|
e = (struct ipt_entry *)
|
|
|
|
(newinfo->entries + pos);
|
|
|
|
} while (oldpos == pos + e->next_offset);
|
|
|
|
|
|
|
|
/* Move along one */
|
|
|
|
size = e->next_offset;
|
|
|
|
e = (struct ipt_entry *)
|
|
|
|
(newinfo->entries + pos + size);
|
|
|
|
e->counters.pcnt = pos;
|
|
|
|
pos += size;
|
|
|
|
} else {
|
|
|
|
int newpos = t->verdict;
|
|
|
|
|
|
|
|
if (strcmp(t->target.u.user.name,
|
|
|
|
IPT_STANDARD_TARGET) == 0
|
|
|
|
&& newpos >= 0) {
|
|
|
|
/* This a jump; chase it. */
|
|
|
|
duprintf("Jump rule %u -> %u\n",
|
|
|
|
pos, newpos);
|
|
|
|
} else {
|
|
|
|
/* ... this is a fallthru */
|
|
|
|
newpos = pos + e->next_offset;
|
|
|
|
}
|
|
|
|
e = (struct ipt_entry *)
|
|
|
|
(newinfo->entries + newpos);
|
|
|
|
e->counters.pcnt = pos;
|
|
|
|
pos = newpos;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
next:
|
|
|
|
duprintf("Finished chain %u\n", hook);
|
|
|
|
}
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline int
|
|
|
|
cleanup_match(struct ipt_entry_match *m, unsigned int *i)
|
|
|
|
{
|
|
|
|
if (i && (*i)-- == 0)
|
|
|
|
return 1;
|
|
|
|
|
|
|
|
if (m->u.kernel.match->destroy)
|
|
|
|
m->u.kernel.match->destroy(m->data,
|
|
|
|
m->u.match_size - sizeof(*m));
|
|
|
|
module_put(m->u.kernel.match->me);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline int
|
|
|
|
standard_check(const struct ipt_entry_target *t,
|
|
|
|
unsigned int max_offset)
|
|
|
|
{
|
|
|
|
struct ipt_standard_target *targ = (void *)t;
|
|
|
|
|
|
|
|
/* Check standard info. */
|
|
|
|
if (t->u.target_size
|
|
|
|
!= IPT_ALIGN(sizeof(struct ipt_standard_target))) {
|
|
|
|
duprintf("standard_check: target size %u != %u\n",
|
|
|
|
t->u.target_size,
|
|
|
|
IPT_ALIGN(sizeof(struct ipt_standard_target)));
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (targ->verdict >= 0
|
|
|
|
&& targ->verdict > max_offset - sizeof(struct ipt_entry)) {
|
|
|
|
duprintf("ipt_standard_check: bad verdict (%i)\n",
|
|
|
|
targ->verdict);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (targ->verdict < -NF_MAX_VERDICT - 1) {
|
|
|
|
duprintf("ipt_standard_check: bad negative verdict (%i)\n",
|
|
|
|
targ->verdict);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline int
|
|
|
|
check_match(struct ipt_entry_match *m,
|
|
|
|
const char *name,
|
|
|
|
const struct ipt_ip *ip,
|
|
|
|
unsigned int hookmask,
|
|
|
|
unsigned int *i)
|
|
|
|
{
|
|
|
|
struct ipt_match *match;
|
|
|
|
|
|
|
|
match = try_then_request_module(find_match(m->u.user.name,
|
|
|
|
m->u.user.revision),
|
|
|
|
"ipt_%s", m->u.user.name);
|
|
|
|
if (IS_ERR(match) || !match) {
|
|
|
|
duprintf("check_match: `%s' not found\n", m->u.user.name);
|
|
|
|
return match ? PTR_ERR(match) : -ENOENT;
|
|
|
|
}
|
|
|
|
m->u.kernel.match = match;
|
|
|
|
|
|
|
|
if (m->u.kernel.match->checkentry
|
|
|
|
&& !m->u.kernel.match->checkentry(name, ip, m->data,
|
|
|
|
m->u.match_size - sizeof(*m),
|
|
|
|
hookmask)) {
|
|
|
|
module_put(m->u.kernel.match->me);
|
|
|
|
duprintf("ip_tables: check failed for `%s'.\n",
|
|
|
|
m->u.kernel.match->name);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
(*i)++;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct ipt_target ipt_standard_target;
|
|
|
|
|
|
|
|
static inline int
|
|
|
|
check_entry(struct ipt_entry *e, const char *name, unsigned int size,
|
|
|
|
unsigned int *i)
|
|
|
|
{
|
|
|
|
struct ipt_entry_target *t;
|
|
|
|
struct ipt_target *target;
|
|
|
|
int ret;
|
|
|
|
unsigned int j;
|
|
|
|
|
|
|
|
if (!ip_checkentry(&e->ip)) {
|
|
|
|
duprintf("ip_tables: ip check failed %p %s.\n", e, name);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
j = 0;
|
|
|
|
ret = IPT_MATCH_ITERATE(e, check_match, name, &e->ip, e->comefrom, &j);
|
|
|
|
if (ret != 0)
|
|
|
|
goto cleanup_matches;
|
|
|
|
|
|
|
|
t = ipt_get_target(e);
|
|
|
|
target = try_then_request_module(find_target(t->u.user.name,
|
|
|
|
t->u.user.revision),
|
|
|
|
"ipt_%s", t->u.user.name);
|
|
|
|
if (IS_ERR(target) || !target) {
|
|
|
|
duprintf("check_entry: `%s' not found\n", t->u.user.name);
|
|
|
|
ret = target ? PTR_ERR(target) : -ENOENT;
|
|
|
|
goto cleanup_matches;
|
|
|
|
}
|
|
|
|
t->u.kernel.target = target;
|
|
|
|
|
|
|
|
if (t->u.kernel.target == &ipt_standard_target) {
|
|
|
|
if (!standard_check(t, size)) {
|
|
|
|
ret = -EINVAL;
|
|
|
|
goto cleanup_matches;
|
|
|
|
}
|
|
|
|
} else if (t->u.kernel.target->checkentry
|
|
|
|
&& !t->u.kernel.target->checkentry(name, e, t->data,
|
|
|
|
t->u.target_size
|
|
|
|
- sizeof(*t),
|
|
|
|
e->comefrom)) {
|
|
|
|
module_put(t->u.kernel.target->me);
|
|
|
|
duprintf("ip_tables: check failed for `%s'.\n",
|
|
|
|
t->u.kernel.target->name);
|
|
|
|
ret = -EINVAL;
|
|
|
|
goto cleanup_matches;
|
|
|
|
}
|
|
|
|
|
|
|
|
(*i)++;
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
cleanup_matches:
|
|
|
|
IPT_MATCH_ITERATE(e, cleanup_match, &j);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline int
|
|
|
|
check_entry_size_and_hooks(struct ipt_entry *e,
|
|
|
|
struct ipt_table_info *newinfo,
|
|
|
|
unsigned char *base,
|
|
|
|
unsigned char *limit,
|
|
|
|
const unsigned int *hook_entries,
|
|
|
|
const unsigned int *underflows,
|
|
|
|
unsigned int *i)
|
|
|
|
{
|
|
|
|
unsigned int h;
|
|
|
|
|
|
|
|
if ((unsigned long)e % __alignof__(struct ipt_entry) != 0
|
|
|
|
|| (unsigned char *)e + sizeof(struct ipt_entry) >= limit) {
|
|
|
|
duprintf("Bad offset %p\n", e);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (e->next_offset
|
|
|
|
< sizeof(struct ipt_entry) + sizeof(struct ipt_entry_target)) {
|
|
|
|
duprintf("checking: element %p size %u\n",
|
|
|
|
e, e->next_offset);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Check hooks & underflows */
|
|
|
|
for (h = 0; h < NF_IP_NUMHOOKS; h++) {
|
|
|
|
if ((unsigned char *)e - base == hook_entries[h])
|
|
|
|
newinfo->hook_entry[h] = hook_entries[h];
|
|
|
|
if ((unsigned char *)e - base == underflows[h])
|
|
|
|
newinfo->underflow[h] = underflows[h];
|
|
|
|
}
|
|
|
|
|
|
|
|
/* FIXME: underflows must be unconditional, standard verdicts
|
|
|
|
< 0 (not IPT_RETURN). --RR */
|
|
|
|
|
|
|
|
/* Clear counters and comefrom */
|
|
|
|
e->counters = ((struct ipt_counters) { 0, 0 });
|
|
|
|
e->comefrom = 0;
|
|
|
|
|
|
|
|
(*i)++;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline int
|
|
|
|
cleanup_entry(struct ipt_entry *e, unsigned int *i)
|
|
|
|
{
|
|
|
|
struct ipt_entry_target *t;
|
|
|
|
|
|
|
|
if (i && (*i)-- == 0)
|
|
|
|
return 1;
|
|
|
|
|
|
|
|
/* Cleanup all matches */
|
|
|
|
IPT_MATCH_ITERATE(e, cleanup_match, NULL);
|
|
|
|
t = ipt_get_target(e);
|
|
|
|
if (t->u.kernel.target->destroy)
|
|
|
|
t->u.kernel.target->destroy(t->data,
|
|
|
|
t->u.target_size - sizeof(*t));
|
|
|
|
module_put(t->u.kernel.target->me);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Checks and translates the user-supplied table segment (held in
|
|
|
|
newinfo) */
|
|
|
|
static int
|
|
|
|
translate_table(const char *name,
|
|
|
|
unsigned int valid_hooks,
|
|
|
|
struct ipt_table_info *newinfo,
|
|
|
|
unsigned int size,
|
|
|
|
unsigned int number,
|
|
|
|
const unsigned int *hook_entries,
|
|
|
|
const unsigned int *underflows)
|
|
|
|
{
|
|
|
|
unsigned int i;
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
newinfo->size = size;
|
|
|
|
newinfo->number = number;
|
|
|
|
|
|
|
|
/* Init all hooks to impossible value. */
|
|
|
|
for (i = 0; i < NF_IP_NUMHOOKS; i++) {
|
|
|
|
newinfo->hook_entry[i] = 0xFFFFFFFF;
|
|
|
|
newinfo->underflow[i] = 0xFFFFFFFF;
|
|
|
|
}
|
|
|
|
|
|
|
|
duprintf("translate_table: size %u\n", newinfo->size);
|
|
|
|
i = 0;
|
|
|
|
/* Walk through entries, checking offsets. */
|
|
|
|
ret = IPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
|
|
|
|
check_entry_size_and_hooks,
|
|
|
|
newinfo,
|
|
|
|
newinfo->entries,
|
|
|
|
newinfo->entries + size,
|
|
|
|
hook_entries, underflows, &i);
|
|
|
|
if (ret != 0)
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
if (i != number) {
|
|
|
|
duprintf("translate_table: %u not %u entries\n",
|
|
|
|
i, number);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Check hooks all assigned */
|
|
|
|
for (i = 0; i < NF_IP_NUMHOOKS; i++) {
|
|
|
|
/* Only hooks which are valid */
|
|
|
|
if (!(valid_hooks & (1 << i)))
|
|
|
|
continue;
|
|
|
|
if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
|
|
|
|
duprintf("Invalid hook entry %u %u\n",
|
|
|
|
i, hook_entries[i]);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
if (newinfo->underflow[i] == 0xFFFFFFFF) {
|
|
|
|
duprintf("Invalid underflow %u %u\n",
|
|
|
|
i, underflows[i]);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!mark_source_chains(newinfo, valid_hooks))
|
|
|
|
return -ELOOP;
|
|
|
|
|
|
|
|
/* Finally, each sanity check must pass */
|
|
|
|
i = 0;
|
|
|
|
ret = IPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
|
|
|
|
check_entry, name, size, &i);
|
|
|
|
|
|
|
|
if (ret != 0) {
|
|
|
|
IPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
|
|
|
|
cleanup_entry, &i);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* And one copy for every other CPU */
|
|
|
|
for (i = 1; i < num_possible_cpus(); i++) {
|
|
|
|
memcpy(newinfo->entries + SMP_ALIGN(newinfo->size)*i,
|
|
|
|
newinfo->entries,
|
|
|
|
SMP_ALIGN(newinfo->size));
|
|
|
|
}
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct ipt_table_info *
|
|
|
|
replace_table(struct ipt_table *table,
|
|
|
|
unsigned int num_counters,
|
|
|
|
struct ipt_table_info *newinfo,
|
|
|
|
int *error)
|
|
|
|
{
|
|
|
|
struct ipt_table_info *oldinfo;
|
|
|
|
|
|
|
|
#ifdef CONFIG_NETFILTER_DEBUG
|
|
|
|
{
|
|
|
|
struct ipt_entry *table_base;
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
for (i = 0; i < num_possible_cpus(); i++) {
|
|
|
|
table_base =
|
|
|
|
(void *)newinfo->entries
|
|
|
|
+ TABLE_OFFSET(newinfo, i);
|
|
|
|
|
|
|
|
table_base->comefrom = 0xdead57ac;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
|
|
/* Do the substitution. */
|
|
|
|
write_lock_bh(&table->lock);
|
|
|
|
/* Check inside lock: is the old number correct? */
|
|
|
|
if (num_counters != table->private->number) {
|
|
|
|
duprintf("num_counters != table->private->number (%u/%u)\n",
|
|
|
|
num_counters, table->private->number);
|
|
|
|
write_unlock_bh(&table->lock);
|
|
|
|
*error = -EAGAIN;
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
oldinfo = table->private;
|
|
|
|
table->private = newinfo;
|
|
|
|
newinfo->initial_entries = oldinfo->initial_entries;
|
|
|
|
write_unlock_bh(&table->lock);
|
|
|
|
|
|
|
|
return oldinfo;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Gets counters. */
|
|
|
|
static inline int
|
|
|
|
add_entry_to_counter(const struct ipt_entry *e,
|
|
|
|
struct ipt_counters total[],
|
|
|
|
unsigned int *i)
|
|
|
|
{
|
|
|
|
ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
|
|
|
|
|
|
|
|
(*i)++;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
get_counters(const struct ipt_table_info *t,
|
|
|
|
struct ipt_counters counters[])
|
|
|
|
{
|
|
|
|
unsigned int cpu;
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
for (cpu = 0; cpu < num_possible_cpus(); cpu++) {
|
|
|
|
i = 0;
|
|
|
|
IPT_ENTRY_ITERATE(t->entries + TABLE_OFFSET(t, cpu),
|
|
|
|
t->size,
|
|
|
|
add_entry_to_counter,
|
|
|
|
counters,
|
|
|
|
&i);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
copy_entries_to_user(unsigned int total_size,
|
|
|
|
struct ipt_table *table,
|
|
|
|
void __user *userptr)
|
|
|
|
{
|
|
|
|
unsigned int off, num, countersize;
|
|
|
|
struct ipt_entry *e;
|
|
|
|
struct ipt_counters *counters;
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
/* We need atomic snapshot of counters: rest doesn't change
|
|
|
|
(other than comefrom, which userspace doesn't care
|
|
|
|
about). */
|
|
|
|
countersize = sizeof(struct ipt_counters) * table->private->number;
|
|
|
|
counters = vmalloc(countersize);
|
|
|
|
|
|
|
|
if (counters == NULL)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
/* First, sum counters... */
|
|
|
|
memset(counters, 0, countersize);
|
|
|
|
write_lock_bh(&table->lock);
|
|
|
|
get_counters(table->private, counters);
|
|
|
|
write_unlock_bh(&table->lock);
|
|
|
|
|
|
|
|
/* ... then copy entire thing from CPU 0... */
|
|
|
|
if (copy_to_user(userptr, table->private->entries, total_size) != 0) {
|
|
|
|
ret = -EFAULT;
|
|
|
|
goto free_counters;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* FIXME: use iterator macros --RR */
|
|
|
|
/* ... then go back and fix counters and names */
|
|
|
|
for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
|
|
|
|
unsigned int i;
|
|
|
|
struct ipt_entry_match *m;
|
|
|
|
struct ipt_entry_target *t;
|
|
|
|
|
|
|
|
e = (struct ipt_entry *)(table->private->entries + off);
|
|
|
|
if (copy_to_user(userptr + off
|
|
|
|
+ offsetof(struct ipt_entry, counters),
|
|
|
|
&counters[num],
|
|
|
|
sizeof(counters[num])) != 0) {
|
|
|
|
ret = -EFAULT;
|
|
|
|
goto free_counters;
|
|
|
|
}
|
|
|
|
|
|
|
|
for (i = sizeof(struct ipt_entry);
|
|
|
|
i < e->target_offset;
|
|
|
|
i += m->u.match_size) {
|
|
|
|
m = (void *)e + i;
|
|
|
|
|
|
|
|
if (copy_to_user(userptr + off + i
|
|
|
|
+ offsetof(struct ipt_entry_match,
|
|
|
|
u.user.name),
|
|
|
|
m->u.kernel.match->name,
|
|
|
|
strlen(m->u.kernel.match->name)+1)
|
|
|
|
!= 0) {
|
|
|
|
ret = -EFAULT;
|
|
|
|
goto free_counters;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
t = ipt_get_target(e);
|
|
|
|
if (copy_to_user(userptr + off + e->target_offset
|
|
|
|
+ offsetof(struct ipt_entry_target,
|
|
|
|
u.user.name),
|
|
|
|
t->u.kernel.target->name,
|
|
|
|
strlen(t->u.kernel.target->name)+1) != 0) {
|
|
|
|
ret = -EFAULT;
|
|
|
|
goto free_counters;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
free_counters:
|
|
|
|
vfree(counters);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
get_entries(const struct ipt_get_entries *entries,
|
|
|
|
struct ipt_get_entries __user *uptr)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
struct ipt_table *t;
|
|
|
|
|
|
|
|
t = find_table_lock(entries->name);
|
|
|
|
if (t && !IS_ERR(t)) {
|
|
|
|
duprintf("t->private->number = %u\n",
|
|
|
|
t->private->number);
|
|
|
|
if (entries->size == t->private->size)
|
|
|
|
ret = copy_entries_to_user(t->private->size,
|
|
|
|
t, uptr->entrytable);
|
|
|
|
else {
|
|
|
|
duprintf("get_entries: I've got %u not %u!\n",
|
|
|
|
t->private->size,
|
|
|
|
entries->size);
|
|
|
|
ret = -EINVAL;
|
|
|
|
}
|
|
|
|
module_put(t->me);
|
|
|
|
up(&ipt_mutex);
|
|
|
|
} else
|
|
|
|
ret = t ? PTR_ERR(t) : -ENOENT;
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
do_replace(void __user *user, unsigned int len)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
struct ipt_replace tmp;
|
|
|
|
struct ipt_table *t;
|
|
|
|
struct ipt_table_info *newinfo, *oldinfo;
|
|
|
|
struct ipt_counters *counters;
|
|
|
|
|
|
|
|
if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
|
|
|
|
return -EFAULT;
|
|
|
|
|
|
|
|
/* Hack: Causes ipchains to give correct error msg --RR */
|
|
|
|
if (len != sizeof(tmp) + tmp.size)
|
|
|
|
return -ENOPROTOOPT;
|
|
|
|
|
|
|
|
/* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
|
|
|
|
if ((SMP_ALIGN(tmp.size) >> PAGE_SHIFT) + 2 > num_physpages)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
newinfo = vmalloc(sizeof(struct ipt_table_info)
|
|
|
|
+ SMP_ALIGN(tmp.size) * num_possible_cpus());
|
|
|
|
if (!newinfo)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
if (copy_from_user(newinfo->entries, user + sizeof(tmp),
|
|
|
|
tmp.size) != 0) {
|
|
|
|
ret = -EFAULT;
|
|
|
|
goto free_newinfo;
|
|
|
|
}
|
|
|
|
|
|
|
|
counters = vmalloc(tmp.num_counters * sizeof(struct ipt_counters));
|
|
|
|
if (!counters) {
|
|
|
|
ret = -ENOMEM;
|
|
|
|
goto free_newinfo;
|
|
|
|
}
|
|
|
|
memset(counters, 0, tmp.num_counters * sizeof(struct ipt_counters));
|
|
|
|
|
|
|
|
ret = translate_table(tmp.name, tmp.valid_hooks,
|
|
|
|
newinfo, tmp.size, tmp.num_entries,
|
|
|
|
tmp.hook_entry, tmp.underflow);
|
|
|
|
if (ret != 0)
|
|
|
|
goto free_newinfo_counters;
|
|
|
|
|
|
|
|
duprintf("ip_tables: Translated table\n");
|
|
|
|
|
|
|
|
t = try_then_request_module(find_table_lock(tmp.name),
|
|
|
|
"iptable_%s", tmp.name);
|
|
|
|
if (!t || IS_ERR(t)) {
|
|
|
|
ret = t ? PTR_ERR(t) : -ENOENT;
|
|
|
|
goto free_newinfo_counters_untrans;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* You lied! */
|
|
|
|
if (tmp.valid_hooks != t->valid_hooks) {
|
|
|
|
duprintf("Valid hook crap: %08X vs %08X\n",
|
|
|
|
tmp.valid_hooks, t->valid_hooks);
|
|
|
|
ret = -EINVAL;
|
|
|
|
goto put_module;
|
|
|
|
}
|
|
|
|
|
|
|
|
oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret);
|
|
|
|
if (!oldinfo)
|
|
|
|
goto put_module;
|
|
|
|
|
|
|
|
/* Update module usage count based on number of rules */
|
|
|
|
duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
|
|
|
|
oldinfo->number, oldinfo->initial_entries, newinfo->number);
|
|
|
|
if ((oldinfo->number > oldinfo->initial_entries) ||
|
|
|
|
(newinfo->number <= oldinfo->initial_entries))
|
|
|
|
module_put(t->me);
|
|
|
|
if ((oldinfo->number > oldinfo->initial_entries) &&
|
|
|
|
(newinfo->number <= oldinfo->initial_entries))
|
|
|
|
module_put(t->me);
|
|
|
|
|
|
|
|
/* Get the old counters. */
|
|
|
|
get_counters(oldinfo, counters);
|
|
|
|
/* Decrease module usage counts and free resource */
|
|
|
|
IPT_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL);
|
|
|
|
vfree(oldinfo);
|
|
|
|
if (copy_to_user(tmp.counters, counters,
|
|
|
|
sizeof(struct ipt_counters) * tmp.num_counters) != 0)
|
|
|
|
ret = -EFAULT;
|
|
|
|
vfree(counters);
|
|
|
|
up(&ipt_mutex);
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
put_module:
|
|
|
|
module_put(t->me);
|
|
|
|
up(&ipt_mutex);
|
|
|
|
free_newinfo_counters_untrans:
|
|
|
|
IPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry,NULL);
|
|
|
|
free_newinfo_counters:
|
|
|
|
vfree(counters);
|
|
|
|
free_newinfo:
|
|
|
|
vfree(newinfo);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* We're lazy, and add to the first CPU; overflow works its fey magic
|
|
|
|
* and everything is OK. */
|
|
|
|
static inline int
|
|
|
|
add_counter_to_entry(struct ipt_entry *e,
|
|
|
|
const struct ipt_counters addme[],
|
|
|
|
unsigned int *i)
|
|
|
|
{
|
|
|
|
#if 0
|
|
|
|
duprintf("add_counter: Entry %u %lu/%lu + %lu/%lu\n",
|
|
|
|
*i,
|
|
|
|
(long unsigned int)e->counters.pcnt,
|
|
|
|
(long unsigned int)e->counters.bcnt,
|
|
|
|
(long unsigned int)addme[*i].pcnt,
|
|
|
|
(long unsigned int)addme[*i].bcnt);
|
|
|
|
#endif
|
|
|
|
|
|
|
|
ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
|
|
|
|
|
|
|
|
(*i)++;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
do_add_counters(void __user *user, unsigned int len)
|
|
|
|
{
|
|
|
|
unsigned int i;
|
|
|
|
struct ipt_counters_info tmp, *paddc;
|
|
|
|
struct ipt_table *t;
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
|
|
|
|
return -EFAULT;
|
|
|
|
|
|
|
|
if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct ipt_counters))
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
paddc = vmalloc(len);
|
|
|
|
if (!paddc)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
if (copy_from_user(paddc, user, len) != 0) {
|
|
|
|
ret = -EFAULT;
|
|
|
|
goto free;
|
|
|
|
}
|
|
|
|
|
|
|
|
t = find_table_lock(tmp.name);
|
|
|
|
if (!t || IS_ERR(t)) {
|
|
|
|
ret = t ? PTR_ERR(t) : -ENOENT;
|
|
|
|
goto free;
|
|
|
|
}
|
|
|
|
|
|
|
|
write_lock_bh(&t->lock);
|
|
|
|
if (t->private->number != paddc->num_counters) {
|
|
|
|
ret = -EINVAL;
|
|
|
|
goto unlock_up_free;
|
|
|
|
}
|
|
|
|
|
|
|
|
i = 0;
|
|
|
|
IPT_ENTRY_ITERATE(t->private->entries,
|
|
|
|
t->private->size,
|
|
|
|
add_counter_to_entry,
|
|
|
|
paddc->counters,
|
|
|
|
&i);
|
|
|
|
unlock_up_free:
|
|
|
|
write_unlock_bh(&t->lock);
|
|
|
|
up(&ipt_mutex);
|
|
|
|
module_put(t->me);
|
|
|
|
free:
|
|
|
|
vfree(paddc);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
do_ipt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
if (!capable(CAP_NET_ADMIN))
|
|
|
|
return -EPERM;
|
|
|
|
|
|
|
|
switch (cmd) {
|
|
|
|
case IPT_SO_SET_REPLACE:
|
|
|
|
ret = do_replace(user, len);
|
|
|
|
break;
|
|
|
|
|
|
|
|
case IPT_SO_SET_ADD_COUNTERS:
|
|
|
|
ret = do_add_counters(user, len);
|
|
|
|
break;
|
|
|
|
|
|
|
|
default:
|
|
|
|
duprintf("do_ipt_set_ctl: unknown request %i\n", cmd);
|
|
|
|
ret = -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
if (!capable(CAP_NET_ADMIN))
|
|
|
|
return -EPERM;
|
|
|
|
|
|
|
|
switch (cmd) {
|
|
|
|
case IPT_SO_GET_INFO: {
|
|
|
|
char name[IPT_TABLE_MAXNAMELEN];
|
|
|
|
struct ipt_table *t;
|
|
|
|
|
|
|
|
if (*len != sizeof(struct ipt_getinfo)) {
|
|
|
|
duprintf("length %u != %u\n", *len,
|
|
|
|
sizeof(struct ipt_getinfo));
|
|
|
|
ret = -EINVAL;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (copy_from_user(name, user, sizeof(name)) != 0) {
|
|
|
|
ret = -EFAULT;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
name[IPT_TABLE_MAXNAMELEN-1] = '\0';
|
|
|
|
|
|
|
|
t = try_then_request_module(find_table_lock(name),
|
|
|
|
"iptable_%s", name);
|
|
|
|
if (t && !IS_ERR(t)) {
|
|
|
|
struct ipt_getinfo info;
|
|
|
|
|
|
|
|
info.valid_hooks = t->valid_hooks;
|
|
|
|
memcpy(info.hook_entry, t->private->hook_entry,
|
|
|
|
sizeof(info.hook_entry));
|
|
|
|
memcpy(info.underflow, t->private->underflow,
|
|
|
|
sizeof(info.underflow));
|
|
|
|
info.num_entries = t->private->number;
|
|
|
|
info.size = t->private->size;
|
|
|
|
memcpy(info.name, name, sizeof(info.name));
|
|
|
|
|
|
|
|
if (copy_to_user(user, &info, *len) != 0)
|
|
|
|
ret = -EFAULT;
|
|
|
|
else
|
|
|
|
ret = 0;
|
|
|
|
up(&ipt_mutex);
|
|
|
|
module_put(t->me);
|
|
|
|
} else
|
|
|
|
ret = t ? PTR_ERR(t) : -ENOENT;
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case IPT_SO_GET_ENTRIES: {
|
|
|
|
struct ipt_get_entries get;
|
|
|
|
|
|
|
|
if (*len < sizeof(get)) {
|
|
|
|
duprintf("get_entries: %u < %u\n", *len, sizeof(get));
|
|
|
|
ret = -EINVAL;
|
|
|
|
} else if (copy_from_user(&get, user, sizeof(get)) != 0) {
|
|
|
|
ret = -EFAULT;
|
|
|
|
} else if (*len != sizeof(struct ipt_get_entries) + get.size) {
|
|
|
|
duprintf("get_entries: %u != %u\n", *len,
|
|
|
|
sizeof(struct ipt_get_entries) + get.size);
|
|
|
|
ret = -EINVAL;
|
|
|
|
} else
|
|
|
|
ret = get_entries(&get, user);
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
case IPT_SO_GET_REVISION_MATCH:
|
|
|
|
case IPT_SO_GET_REVISION_TARGET: {
|
|
|
|
struct ipt_get_revision rev;
|
|
|
|
int (*revfn)(const char *, u8, int *);
|
|
|
|
|
|
|
|
if (*len != sizeof(rev)) {
|
|
|
|
ret = -EINVAL;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
|
|
|
|
ret = -EFAULT;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (cmd == IPT_SO_GET_REVISION_TARGET)
|
|
|
|
revfn = target_revfn;
|
|
|
|
else
|
|
|
|
revfn = match_revfn;
|
|
|
|
|
|
|
|
try_then_request_module(find_revision(rev.name, rev.revision,
|
|
|
|
revfn, &ret),
|
|
|
|
"ipt_%s", rev.name);
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
default:
|
|
|
|
duprintf("do_ipt_get_ctl: unknown request %i\n", cmd);
|
|
|
|
ret = -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Registration hooks for targets. */
|
|
|
|
int
|
|
|
|
ipt_register_target(struct ipt_target *target)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
ret = down_interruptible(&ipt_mutex);
|
|
|
|
if (ret != 0)
|
|
|
|
return ret;
|
|
|
|
list_add(&target->list, &ipt_target);
|
|
|
|
up(&ipt_mutex);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
void
|
|
|
|
ipt_unregister_target(struct ipt_target *target)
|
|
|
|
{
|
|
|
|
down(&ipt_mutex);
|
|
|
|
LIST_DELETE(&ipt_target, target);
|
|
|
|
up(&ipt_mutex);
|
|
|
|
}
|
|
|
|
|
|
|
|
int
|
|
|
|
ipt_register_match(struct ipt_match *match)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
ret = down_interruptible(&ipt_mutex);
|
|
|
|
if (ret != 0)
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
list_add(&match->list, &ipt_match);
|
|
|
|
up(&ipt_mutex);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
void
|
|
|
|
ipt_unregister_match(struct ipt_match *match)
|
|
|
|
{
|
|
|
|
down(&ipt_mutex);
|
|
|
|
LIST_DELETE(&ipt_match, match);
|
|
|
|
up(&ipt_mutex);
|
|
|
|
}
|
|
|
|
|
|
|
|
int ipt_register_table(struct ipt_table *table, const struct ipt_replace *repl)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
struct ipt_table_info *newinfo;
|
|
|
|
static struct ipt_table_info bootstrap
|
|
|
|
= { 0, 0, 0, { 0 }, { 0 }, { } };
|
|
|
|
|
|
|
|
newinfo = vmalloc(sizeof(struct ipt_table_info)
|
|
|
|
+ SMP_ALIGN(repl->size) * num_possible_cpus());
|
|
|
|
if (!newinfo)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
memcpy(newinfo->entries, repl->entries, repl->size);
|
|
|
|
|
|
|
|
ret = translate_table(table->name, table->valid_hooks,
|
|
|
|
newinfo, repl->size,
|
|
|
|
repl->num_entries,
|
|
|
|
repl->hook_entry,
|
|
|
|
repl->underflow);
|
|
|
|
if (ret != 0) {
|
|
|
|
vfree(newinfo);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
ret = down_interruptible(&ipt_mutex);
|
|
|
|
if (ret != 0) {
|
|
|
|
vfree(newinfo);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Don't autoload: we'd eat our tail... */
|
|
|
|
if (list_named_find(&ipt_tables, table->name)) {
|
|
|
|
ret = -EEXIST;
|
|
|
|
goto free_unlock;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Simplifies replace_table code. */
|
|
|
|
table->private = &bootstrap;
|
|
|
|
if (!replace_table(table, 0, newinfo, &ret))
|
|
|
|
goto free_unlock;
|
|
|
|
|
|
|
|
duprintf("table->private->number = %u\n",
|
|
|
|
table->private->number);
|
|
|
|
|
|
|
|
/* save number of initial entries */
|
|
|
|
table->private->initial_entries = table->private->number;
|
|
|
|
|
|
|
|
rwlock_init(&table->lock);
|
|
|
|
list_prepend(&ipt_tables, table);
|
|
|
|
|
|
|
|
unlock:
|
|
|
|
up(&ipt_mutex);
|
|
|
|
return ret;
|
|
|
|
|
|
|
|
free_unlock:
|
|
|
|
vfree(newinfo);
|
|
|
|
goto unlock;
|
|
|
|
}
|
|
|
|
|
|
|
|
void ipt_unregister_table(struct ipt_table *table)
|
|
|
|
{
|
|
|
|
down(&ipt_mutex);
|
|
|
|
LIST_DELETE(&ipt_tables, table);
|
|
|
|
up(&ipt_mutex);
|
|
|
|
|
|
|
|
/* Decrease module usage counts and free resources */
|
|
|
|
IPT_ENTRY_ITERATE(table->private->entries, table->private->size,
|
|
|
|
cleanup_entry, NULL);
|
|
|
|
vfree(table->private);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Returns 1 if the port is matched by the range, 0 otherwise */
|
|
|
|
static inline int
|
|
|
|
port_match(u_int16_t min, u_int16_t max, u_int16_t port, int invert)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
ret = (port >= min && port <= max) ^ invert;
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
tcp_find_option(u_int8_t option,
|
|
|
|
const struct sk_buff *skb,
|
|
|
|
unsigned int optlen,
|
|
|
|
int invert,
|
|
|
|
int *hotdrop)
|
|
|
|
{
|
|
|
|
/* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */
|
|
|
|
u_int8_t _opt[60 - sizeof(struct tcphdr)], *op;
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
duprintf("tcp_match: finding option\n");
|
|
|
|
|
|
|
|
if (!optlen)
|
|
|
|
return invert;
|
|
|
|
|
|
|
|
/* If we don't have the whole header, drop packet. */
|
|
|
|
op = skb_header_pointer(skb,
|
|
|
|
skb->nh.iph->ihl*4 + sizeof(struct tcphdr),
|
|
|
|
optlen, _opt);
|
|
|
|
if (op == NULL) {
|
|
|
|
*hotdrop = 1;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
for (i = 0; i < optlen; ) {
|
|
|
|
if (op[i] == option) return !invert;
|
|
|
|
if (op[i] < 2) i++;
|
|
|
|
else i += op[i+1]?:1;
|
|
|
|
}
|
|
|
|
|
|
|
|
return invert;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
tcp_match(const struct sk_buff *skb,
|
|
|
|
const struct net_device *in,
|
|
|
|
const struct net_device *out,
|
|
|
|
const void *matchinfo,
|
|
|
|
int offset,
|
|
|
|
int *hotdrop)
|
|
|
|
{
|
|
|
|
struct tcphdr _tcph, *th;
|
|
|
|
const struct ipt_tcp *tcpinfo = matchinfo;
|
|
|
|
|
|
|
|
if (offset) {
|
|
|
|
/* To quote Alan:
|
|
|
|
|
|
|
|
Don't allow a fragment of TCP 8 bytes in. Nobody normal
|
|
|
|
causes this. Its a cracker trying to break in by doing a
|
|
|
|
flag overwrite to pass the direction checks.
|
|
|
|
*/
|
|
|
|
if (offset == 1) {
|
|
|
|
duprintf("Dropping evil TCP offset=1 frag.\n");
|
|
|
|
*hotdrop = 1;
|
|
|
|
}
|
|
|
|
/* Must not be a fragment. */
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
#define FWINVTCP(bool,invflg) ((bool) ^ !!(tcpinfo->invflags & invflg))
|
|
|
|
|
|
|
|
th = skb_header_pointer(skb, skb->nh.iph->ihl*4,
|
|
|
|
sizeof(_tcph), &_tcph);
|
|
|
|
if (th == NULL) {
|
|
|
|
/* We've been asked to examine this packet, and we
|
|
|
|
can't. Hence, no choice but to drop. */
|
|
|
|
duprintf("Dropping evil TCP offset=0 tinygram.\n");
|
|
|
|
*hotdrop = 1;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!port_match(tcpinfo->spts[0], tcpinfo->spts[1],
|
|
|
|
ntohs(th->source),
|
|
|
|
!!(tcpinfo->invflags & IPT_TCP_INV_SRCPT)))
|
|
|
|
return 0;
|
|
|
|
if (!port_match(tcpinfo->dpts[0], tcpinfo->dpts[1],
|
|
|
|
ntohs(th->dest),
|
|
|
|
!!(tcpinfo->invflags & IPT_TCP_INV_DSTPT)))
|
|
|
|
return 0;
|
|
|
|
if (!FWINVTCP((((unsigned char *)th)[13] & tcpinfo->flg_mask)
|
|
|
|
== tcpinfo->flg_cmp,
|
|
|
|
IPT_TCP_INV_FLAGS))
|
|
|
|
return 0;
|
|
|
|
if (tcpinfo->option) {
|
|
|
|
if (th->doff * 4 < sizeof(_tcph)) {
|
|
|
|
*hotdrop = 1;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
if (!tcp_find_option(tcpinfo->option, skb,
|
|
|
|
th->doff*4 - sizeof(_tcph),
|
|
|
|
tcpinfo->invflags & IPT_TCP_INV_OPTION,
|
|
|
|
hotdrop))
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Called when user tries to insert an entry of this type. */
|
|
|
|
static int
|
|
|
|
tcp_checkentry(const char *tablename,
|
|
|
|
const struct ipt_ip *ip,
|
|
|
|
void *matchinfo,
|
|
|
|
unsigned int matchsize,
|
|
|
|
unsigned int hook_mask)
|
|
|
|
{
|
|
|
|
const struct ipt_tcp *tcpinfo = matchinfo;
|
|
|
|
|
|
|
|
/* Must specify proto == TCP, and no unknown invflags */
|
|
|
|
return ip->proto == IPPROTO_TCP
|
|
|
|
&& !(ip->invflags & IPT_INV_PROTO)
|
|
|
|
&& matchsize == IPT_ALIGN(sizeof(struct ipt_tcp))
|
|
|
|
&& !(tcpinfo->invflags & ~IPT_TCP_INV_MASK);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
udp_match(const struct sk_buff *skb,
|
|
|
|
const struct net_device *in,
|
|
|
|
const struct net_device *out,
|
|
|
|
const void *matchinfo,
|
|
|
|
int offset,
|
|
|
|
int *hotdrop)
|
|
|
|
{
|
|
|
|
struct udphdr _udph, *uh;
|
|
|
|
const struct ipt_udp *udpinfo = matchinfo;
|
|
|
|
|
|
|
|
/* Must not be a fragment. */
|
|
|
|
if (offset)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
uh = skb_header_pointer(skb, skb->nh.iph->ihl*4,
|
|
|
|
sizeof(_udph), &_udph);
|
|
|
|
if (uh == NULL) {
|
|
|
|
/* We've been asked to examine this packet, and we
|
|
|
|
can't. Hence, no choice but to drop. */
|
|
|
|
duprintf("Dropping evil UDP tinygram.\n");
|
|
|
|
*hotdrop = 1;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
return port_match(udpinfo->spts[0], udpinfo->spts[1],
|
|
|
|
ntohs(uh->source),
|
|
|
|
!!(udpinfo->invflags & IPT_UDP_INV_SRCPT))
|
|
|
|
&& port_match(udpinfo->dpts[0], udpinfo->dpts[1],
|
|
|
|
ntohs(uh->dest),
|
|
|
|
!!(udpinfo->invflags & IPT_UDP_INV_DSTPT));
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Called when user tries to insert an entry of this type. */
|
|
|
|
static int
|
|
|
|
udp_checkentry(const char *tablename,
|
|
|
|
const struct ipt_ip *ip,
|
|
|
|
void *matchinfo,
|
|
|
|
unsigned int matchinfosize,
|
|
|
|
unsigned int hook_mask)
|
|
|
|
{
|
|
|
|
const struct ipt_udp *udpinfo = matchinfo;
|
|
|
|
|
|
|
|
/* Must specify proto == UDP, and no unknown invflags */
|
|
|
|
if (ip->proto != IPPROTO_UDP || (ip->invflags & IPT_INV_PROTO)) {
|
|
|
|
duprintf("ipt_udp: Protocol %u != %u\n", ip->proto,
|
|
|
|
IPPROTO_UDP);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
if (matchinfosize != IPT_ALIGN(sizeof(struct ipt_udp))) {
|
|
|
|
duprintf("ipt_udp: matchsize %u != %u\n",
|
|
|
|
matchinfosize, IPT_ALIGN(sizeof(struct ipt_udp)));
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
if (udpinfo->invflags & ~IPT_UDP_INV_MASK) {
|
|
|
|
duprintf("ipt_udp: unknown flags %X\n",
|
|
|
|
udpinfo->invflags);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Returns 1 if the type and code is matched by the range, 0 otherwise */
|
|
|
|
static inline int
|
|
|
|
icmp_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code,
|
|
|
|
u_int8_t type, u_int8_t code,
|
|
|
|
int invert)
|
|
|
|
{
|
|
|
|
return ((test_type == 0xFF) || (type == test_type && code >= min_code && code <= max_code))
|
|
|
|
^ invert;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
|
|
|
icmp_match(const struct sk_buff *skb,
|
|
|
|
const struct net_device *in,
|
|
|
|
const struct net_device *out,
|
|
|
|
const void *matchinfo,
|
|
|
|
int offset,
|
|
|
|
int *hotdrop)
|
|
|
|
{
|
|
|
|
struct icmphdr _icmph, *ic;
|
|
|
|
const struct ipt_icmp *icmpinfo = matchinfo;
|
|
|
|
|
|
|
|
/* Must not be a fragment. */
|
|
|
|
if (offset)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
ic = skb_header_pointer(skb, skb->nh.iph->ihl*4,
|
|
|
|
sizeof(_icmph), &_icmph);
|
|
|
|
if (ic == NULL) {
|
|
|
|
/* We've been asked to examine this packet, and we
|
|
|
|
* can't. Hence, no choice but to drop.
|
|
|
|
*/
|
|
|
|
duprintf("Dropping evil ICMP tinygram.\n");
|
|
|
|
*hotdrop = 1;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
return icmp_type_code_match(icmpinfo->type,
|
|
|
|
icmpinfo->code[0],
|
|
|
|
icmpinfo->code[1],
|
|
|
|
ic->type, ic->code,
|
|
|
|
!!(icmpinfo->invflags&IPT_ICMP_INV));
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Called when user tries to insert an entry of this type. */
|
|
|
|
static int
|
|
|
|
icmp_checkentry(const char *tablename,
|
|
|
|
const struct ipt_ip *ip,
|
|
|
|
void *matchinfo,
|
|
|
|
unsigned int matchsize,
|
|
|
|
unsigned int hook_mask)
|
|
|
|
{
|
|
|
|
const struct ipt_icmp *icmpinfo = matchinfo;
|
|
|
|
|
|
|
|
/* Must specify proto == ICMP, and no unknown invflags */
|
|
|
|
return ip->proto == IPPROTO_ICMP
|
|
|
|
&& !(ip->invflags & IPT_INV_PROTO)
|
|
|
|
&& matchsize == IPT_ALIGN(sizeof(struct ipt_icmp))
|
|
|
|
&& !(icmpinfo->invflags & ~IPT_ICMP_INV);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* The built-in targets: standard (NULL) and error. */
|
|
|
|
static struct ipt_target ipt_standard_target = {
|
|
|
|
.name = IPT_STANDARD_TARGET,
|
|
|
|
};
|
|
|
|
|
|
|
|
static struct ipt_target ipt_error_target = {
|
|
|
|
.name = IPT_ERROR_TARGET,
|
|
|
|
.target = ipt_error,
|
|
|
|
};
|
|
|
|
|
|
|
|
static struct nf_sockopt_ops ipt_sockopts = {
|
|
|
|
.pf = PF_INET,
|
|
|
|
.set_optmin = IPT_BASE_CTL,
|
|
|
|
.set_optmax = IPT_SO_SET_MAX+1,
|
|
|
|
.set = do_ipt_set_ctl,
|
|
|
|
.get_optmin = IPT_BASE_CTL,
|
|
|
|
.get_optmax = IPT_SO_GET_MAX+1,
|
|
|
|
.get = do_ipt_get_ctl,
|
|
|
|
};
|
|
|
|
|
|
|
|
static struct ipt_match tcp_matchstruct = {
|
|
|
|
.name = "tcp",
|
|
|
|
.match = &tcp_match,
|
|
|
|
.checkentry = &tcp_checkentry,
|
|
|
|
};
|
|
|
|
|
|
|
|
static struct ipt_match udp_matchstruct = {
|
|
|
|
.name = "udp",
|
|
|
|
.match = &udp_match,
|
|
|
|
.checkentry = &udp_checkentry,
|
|
|
|
};
|
|
|
|
|
|
|
|
static struct ipt_match icmp_matchstruct = {
|
|
|
|
.name = "icmp",
|
|
|
|
.match = &icmp_match,
|
|
|
|
.checkentry = &icmp_checkentry,
|
|
|
|
};
|
|
|
|
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
|
|
static inline int print_name(const char *i,
|
|
|
|
off_t start_offset, char *buffer, int length,
|
|
|
|
off_t *pos, unsigned int *count)
|
|
|
|
{
|
|
|
|
if ((*count)++ >= start_offset) {
|
|
|
|
unsigned int namelen;
|
|
|
|
|
|
|
|
namelen = sprintf(buffer + *pos, "%s\n",
|
|
|
|
i + sizeof(struct list_head));
|
|
|
|
if (*pos + namelen > length) {
|
|
|
|
/* Stop iterating */
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
*pos += namelen;
|
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline int print_target(const struct ipt_target *t,
|
|
|
|
off_t start_offset, char *buffer, int length,
|
|
|
|
off_t *pos, unsigned int *count)
|
|
|
|
{
|
|
|
|
if (t == &ipt_standard_target || t == &ipt_error_target)
|
|
|
|
return 0;
|
|
|
|
return print_name((char *)t, start_offset, buffer, length, pos, count);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int ipt_get_tables(char *buffer, char **start, off_t offset, int length)
|
|
|
|
{
|
|
|
|
off_t pos = 0;
|
|
|
|
unsigned int count = 0;
|
|
|
|
|
|
|
|
if (down_interruptible(&ipt_mutex) != 0)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
LIST_FIND(&ipt_tables, print_name, void *,
|
|
|
|
offset, buffer, length, &pos, &count);
|
|
|
|
|
|
|
|
up(&ipt_mutex);
|
|
|
|
|
|
|
|
/* `start' hack - see fs/proc/generic.c line ~105 */
|
|
|
|
*start=(char *)((unsigned long)count-offset);
|
|
|
|
return pos;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int ipt_get_targets(char *buffer, char **start, off_t offset, int length)
|
|
|
|
{
|
|
|
|
off_t pos = 0;
|
|
|
|
unsigned int count = 0;
|
|
|
|
|
|
|
|
if (down_interruptible(&ipt_mutex) != 0)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
LIST_FIND(&ipt_target, print_target, struct ipt_target *,
|
|
|
|
offset, buffer, length, &pos, &count);
|
|
|
|
|
|
|
|
up(&ipt_mutex);
|
|
|
|
|
|
|
|
*start = (char *)((unsigned long)count - offset);
|
|
|
|
return pos;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int ipt_get_matches(char *buffer, char **start, off_t offset, int length)
|
|
|
|
{
|
|
|
|
off_t pos = 0;
|
|
|
|
unsigned int count = 0;
|
|
|
|
|
|
|
|
if (down_interruptible(&ipt_mutex) != 0)
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
LIST_FIND(&ipt_match, print_name, void *,
|
|
|
|
offset, buffer, length, &pos, &count);
|
|
|
|
|
|
|
|
up(&ipt_mutex);
|
|
|
|
|
|
|
|
*start = (char *)((unsigned long)count - offset);
|
|
|
|
return pos;
|
|
|
|
}
|
|
|
|
|
|
|
|
static struct { char *name; get_info_t *get_info; } ipt_proc_entry[] =
|
|
|
|
{ { "ip_tables_names", ipt_get_tables },
|
|
|
|
{ "ip_tables_targets", ipt_get_targets },
|
|
|
|
{ "ip_tables_matches", ipt_get_matches },
|
|
|
|
{ NULL, NULL} };
|
|
|
|
#endif /*CONFIG_PROC_FS*/
|
|
|
|
|
|
|
|
static int __init init(void)
|
|
|
|
{
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
/* Noone else will be downing sem now, so we won't sleep */
|
|
|
|
down(&ipt_mutex);
|
|
|
|
list_append(&ipt_target, &ipt_standard_target);
|
|
|
|
list_append(&ipt_target, &ipt_error_target);
|
|
|
|
list_append(&ipt_match, &tcp_matchstruct);
|
|
|
|
list_append(&ipt_match, &udp_matchstruct);
|
|
|
|
list_append(&ipt_match, &icmp_matchstruct);
|
|
|
|
up(&ipt_mutex);
|
|
|
|
|
|
|
|
/* Register setsockopt */
|
|
|
|
ret = nf_register_sockopt(&ipt_sockopts);
|
|
|
|
if (ret < 0) {
|
|
|
|
duprintf("Unable to register sockopts.\n");
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
|
|
{
|
|
|
|
struct proc_dir_entry *proc;
|
|
|
|
int i;
|
|
|
|
|
|
|
|
for (i = 0; ipt_proc_entry[i].name; i++) {
|
|
|
|
proc = proc_net_create(ipt_proc_entry[i].name, 0,
|
|
|
|
ipt_proc_entry[i].get_info);
|
|
|
|
if (!proc) {
|
|
|
|
while (--i >= 0)
|
|
|
|
proc_net_remove(ipt_proc_entry[i].name);
|
|
|
|
nf_unregister_sockopt(&ipt_sockopts);
|
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
proc->owner = THIS_MODULE;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
|
|
printk("ip_tables: (C) 2000-2002 Netfilter core team\n");
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void __exit fini(void)
|
|
|
|
{
|
|
|
|
nf_unregister_sockopt(&ipt_sockopts);
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
|
|
{
|
|
|
|
int i;
|
|
|
|
for (i = 0; ipt_proc_entry[i].name; i++)
|
|
|
|
proc_net_remove(ipt_proc_entry[i].name);
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
}
|
|
|
|
|
|
|
|
EXPORT_SYMBOL(ipt_register_table);
|
|
|
|
EXPORT_SYMBOL(ipt_unregister_table);
|
|
|
|
EXPORT_SYMBOL(ipt_register_match);
|
|
|
|
EXPORT_SYMBOL(ipt_unregister_match);
|
|
|
|
EXPORT_SYMBOL(ipt_do_table);
|
|
|
|
EXPORT_SYMBOL(ipt_register_target);
|
|
|
|
EXPORT_SYMBOL(ipt_unregister_target);
|
|
|
|
EXPORT_SYMBOL(ipt_find_target);
|
|
|
|
|
|
|
|
module_init(init);
|
|
|
|
module_exit(fini);
|