/*
* Packet matching code.
*
* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
* Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 19 Jan 2002 Harald Welte <laforge@gnumonks.org>
* - increase module usage count as soon as we have rules inside
* a table
* 08 Oct 2005 Harald Welte <lafore@netfilter.org>
* - Generalize into "x_tables" layer and "{ip,ip6,arp}_tables"
*/
#include <linux/cache.h>
#include <linux/capability.h>
#include <linux/skbuff.h>
#include <linux/kmod.h>
#include <linux/vmalloc.h>
#include <linux/netdevice.h>
#include <linux/module.h>
#include <linux/icmp.h>
#include <net/ip.h>
#include <net/compat.h>
#include <asm/uaccess.h>
#include <linux/mutex.h>
#include <linux/proc_fs.h>
#include <linux/err.h>
#include <linux/cpumask.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv4/ip_tables.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("IPv4 packet filter");
/*#define DEBUG_IP_FIREWALL*/
/*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */
/*#define DEBUG_IP_FIREWALL_USER*/
#ifdef DEBUG_IP_FIREWALL
#define dprintf(format, args...) printk(format , ## args)
#else
#define dprintf(format, args...)
#endif
#ifdef DEBUG_IP_FIREWALL_USER
#define duprintf(format, args...) printk(format , ## args)
#else
#define duprintf(format, args...)
#endif
#ifdef CONFIG_NETFILTER_DEBUG
#define IP_NF_ASSERT(x) \
do { \
if (!(x)) \
printk("IP_NF_ASSERT: %s:%s:%u\n", \
__FUNCTION__, __FILE__, __LINE__); \
} while(0)
#else
#define IP_NF_ASSERT(x)
#endif
#if 0
/* All the better to debug you with... */
#define static
#define inline
#endif
/*
We keep a set of rules for each CPU, so we can avoid write-locking
them in the softirq when updating the counters and therefore
only need to read-lock in the softirq; doing a write_lock_bh() in user
context stops packets coming through and allows user context to read
the counters or update the rules.
Hence the start of any table is given by get_table() below. */
/* Returns whether matches rule or not. */
static inline int
ip_packet_match(const struct iphdr *ip,
const char *indev,
const char *outdev,
const struct ipt_ip *ipinfo,
int isfrag)
{
size_t i;
unsigned long ret;
#define FWINV(bool,invflg) ((bool) ^ !!(ipinfo->invflags & invflg))
if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
IPT_INV_SRCIP)
|| FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
IPT_INV_DSTIP)) {
dprintf("Source or dest mismatch.\n");
dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
NIPQUAD(ip->saddr),
NIPQUAD(ipinfo->smsk.s_addr),
NIPQUAD(ipinfo->src.s_addr),
ipinfo->invflags & IPT_INV_SRCIP ? " (INV)" : "");
dprintf("DST: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
NIPQUAD(ip->daddr),
NIPQUAD(ipinfo->dmsk.s_addr),
NIPQUAD(ipinfo->dst.s_addr),
ipinfo->invflags & IPT_INV_DSTIP ? " (INV)" : "");
return 0;
}
/* Look for ifname matches; this should unroll nicely. */
for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
ret |= (((const unsigned long *)indev)[i]
^ ((const unsigned long *)ipinfo->iniface)[i])
& ((const unsigned long *)ipinfo->iniface_mask)[i];
}
if (FWINV(ret != 0, IPT_INV_VIA_IN)) {
dprintf("VIA in mismatch (%s vs %s).%s\n",
indev, ipinfo->iniface,
ipinfo->invflags&IPT_INV_VIA_IN ?" (INV)":"");
return 0;
}
for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
ret |= (((const unsigned long *)outdev)[i]
^ ((const unsigned long *)ipinfo->outiface)[i])
& ((const unsigned long *)ipinfo->outiface_mask)[i];
}
if (FWINV(ret != 0, IPT_INV_VIA_OUT)) {
dprintf("VIA out mismatch (%s vs %s).%s\n",
outdev, ipinfo->outiface,
ipinfo->invflags&IPT_INV_VIA_OUT ?" (INV)":"");
return 0;
}
/* Check specific protocol */
if (ipinfo->proto
&& FWINV(ip->protocol != ipinfo->proto, IPT_INV_PROTO)) {
dprintf("Packet protocol %hi does not match %hi.%s\n",
ip->protocol, ipinfo->proto,
ipinfo->invflags&IPT_INV_PROTO ? " (INV)":"");
return 0;
}
/* If we have a fragment rule but the packet is not a fragment
* then we return zero */
if (FWINV((ipinfo->flags&IPT_F_FRAG) && !isfrag, IPT_INV_FRAG)) {
dprintf("Fragment rule but not fragment.%s\n",
ipinfo->invflags & IPT_INV_FRAG ? " (INV)" : "");
return 0;
}
return 1;
}
static inline int
ip_checkentry(const struct ipt_ip *ip)
{
if (ip->flags & ~IPT_F_MASK) {
duprintf("Unknown flag bits set: %08X\n",
ip->flags & ~IPT_F_MASK);
return 0;
}
if (ip->invflags & ~IPT_INV_MASK) {
duprintf("Unknown invflag bits set: %08X\n",
ip->invflags & ~IPT_INV_MASK);
return 0;
}
return 1;
}
static unsigned int
ipt_error(struct sk_buff **pskb,
const struct net_device *in,
const struct net_device *out,
unsigned int hooknum,
const struct xt_target *target,
const void *targinfo,
void *userinfo)
{
if (net_ratelimit())
printk("ip_tables: error: `%s'\n", (char *)targinfo);
return NF_DROP;
}
static inline
int do_match(struct ipt_entry_match *m,
const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
int offset,
int *hotdrop)
{
/* Stop iteration if it doesn't match */
if (!m->u.kernel.match->match(skb, in, out, m->u.kernel.match, m->data,
offset, skb->nh.iph->ihl*4, hotdrop))
return 1;
else
return 0;
}
static inline struct ipt_entry *
get_entry(void *base, unsigned int offset)
{
return (struct ipt_entry *)(base + offset);
}
/* Returns one of the generic firewall policies, like NF_ACCEPT. */
unsigned int
ipt_do_table(struct sk_buff **pskb,
unsigned int hook,
const struct net_device *in,
const struct net_device *out,
struct ipt_table *table,
void *userdata)
{
static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
u_int16_t offset;
struct iphdr *ip;
u_int16_t datalen;
int hotdrop = 0;
/* Initializing verdict to NF_DROP keeps gcc happy. */
unsigned int verdict = NF_DROP;
const char *indev, *outdev;
void *table_base;
struct ipt_entry *e, *back;
struct xt_table_info *private = table->private;
/* Initialization */
ip = (*pskb)->nh.iph;
datalen = (*pskb)->len - ip->ihl * 4;
indev = in ? in->name : nulldevname;
outdev = out ? out->name : nulldevname;
/* We handle fragments by dealing with the first fragment as
* if it was a normal packet. All other fragments are treated
* normally, except that they will NEVER match rules that ask
* things we don't know, ie. tcp syn flag or ports). If the
* rule is also a fragment-specific rule, non-fragments won't
* match it. */
offset = ntohs(ip->frag_off) & IP_OFFSET;
read_lock_bh(&table->lock);
IP_NF_ASSERT(table->valid_hooks & (1 << hook));
table_base = (void *)private->entries[smp_processor_id()];
e = get_entry(table_base, private->hook_entry[hook]);
/* For return from builtin chain */
back = get_entry(table_base, private->underflow[hook]);
do {
IP_NF_ASSERT(e);
IP_NF_ASSERT(back);
if (ip_packet_match(ip, indev, outdev, &e->ip, offset)) {
struct ipt_entry_target *t;
if (IPT_MATCH_ITERATE(e, do_match,
*pskb, in, out,
offset, &hotdrop) != 0)
goto no_match;
ADD_COUNTER(e->counters, ntohs(ip->tot_len), 1);
t = ipt_get_target(e);
IP_NF_ASSERT(t->u.kernel.target);
/* Standard target? */
if (!t->u.kernel.target->target) {
int v;
v = ((struct ipt_standard_target *)t)->verdict;
if (v < 0) {
/* Pop from stack? */
if (v != IPT_RETURN) {
verdict = (unsigned)(-v) - 1;
break;
}
e = back;
back = get_entry(table_base,
back->comefrom);
continue;
}
if (table_base + v != (void *)e + e->next_offset
&& !(e->ip.flags & IPT_F_GOTO)) {
/* Save old back ptr in next entry */
struct ipt_entry *next
= (void *)e + e->next_offset;
next->comefrom
= (void *)back - table_base;
/* set back pointer to next entry */
back = next;
}
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->u.kernel.target,
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);
read_unlock_bh(&table->lock);
#ifdef DEBUG_ALLOW_ALL
return NF_ACCEPT;
#else
if (hotdrop)
return NF_DROP;
else return verdict;
#endif
}
/* 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 xt_table_info *newinfo,
unsigned int valid_hooks, void *entry0)
{
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 *)(entry0 + 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 *)
(entry0 + pos);
} while (oldpos == pos + e->next_offset);
/* Move along one */
size = e->next_offset;
e = (struct ipt_entry *)
(entry0 + 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 *)
(entry0 + 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->u.kernel.match, 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 (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;
int ret;
match = try_then_request_module(xt_find_match(AF_INET, 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;
ret = xt_check_match(match, AF_INET, m->u.match_size - sizeof(*m),
name, hookmask, ip->proto,
ip->invflags & IPT_INV_PROTO);
if (ret)
goto err;
if (m->u.kernel.match->checkentry
&& !m->u.kernel.match->checkentry(name, ip, match, m->data,
m->u.match_size - sizeof(*m),
hookmask)) {
duprintf("ip_tables: check failed for `%s'.\n",
m->u.kernel.match->name);
ret = -EINVAL;
goto err;
}
(*i)++;
return 0;
err:
module_put(m->u.kernel.match->me);
return ret;
}
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(xt_find_target(AF_INET,
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;
ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t),
name, e->comefrom, e->ip.proto,
e->ip.invflags & IPT_INV_PROTO);
if (ret)
goto err;
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, target, t->data,
t->u.target_size
- sizeof(*t),
e->comefrom)) {
duprintf("ip_tables: check failed for `%s'.\n",
t->u.kernel.target->name);
ret = -EINVAL;
goto err;
}
(*i)++;
return 0;
err:
module_put(t->u.kernel.target->me);
cleanup_matches:
IPT_MATCH_ITERATE(e, cleanup_match, &j);
return ret;
}
static inline int
check_entry_size_and_hooks(struct ipt_entry *e,
struct xt_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 xt_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->u.kernel.target, 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 xt_table_info *newinfo,
void *entry0,
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(entry0, newinfo->size,
check_entry_size_and_hooks,
newinfo,
entry0,
entry0 + 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, entry0))
return -ELOOP;
/* Finally, each sanity check must pass */
i = 0;
ret = IPT_ENTRY_ITERATE(entry0, newinfo->size,
check_entry, name, size, &i);
if (ret != 0) {
IPT_ENTRY_ITERATE(entry0, newinfo->size,
cleanup_entry, &i);
return ret;
}
/* And one copy for every other CPU */
for_each_possible_cpu(i) {
if (newinfo->entries[i] && newinfo->entries[i] != entry0)
memcpy(newinfo->entries[i], entry0, newinfo->size);
}
return ret;
}
/* Gets counters. */
static inline int
add_entry_to_counter(const struct ipt_entry *e,
struct xt_counters total[],
unsigned int *i)
{
ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
(*i)++;
return 0;
}
static inline int
set_entry_to_counter(const struct ipt_entry *e,
struct ipt_counters total[],
unsigned int *i)
{
SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
(*i)++;
return 0;
}
static void
get_counters(const struct xt_table_info *t,
struct xt_counters counters[])
{
unsigned int cpu;
unsigned int i;
unsigned int curcpu;
/* Instead of clearing (by a previous call to memset())
* the counters and using adds, we set the counters
* with data used by 'current' CPU
* We dont care about preemption here.
*/
curcpu = raw_smp_processor_id();
i = 0;
IPT_ENTRY_ITERATE(t->entries[curcpu],
t->size,
set_entry_to_counter,
counters,
&i);
for_each_possible_cpu(cpu) {
if (cpu == curcpu)
continue;
i = 0;
IPT_ENTRY_ITERATE(t->entries[cpu],
t->size,
add_entry_to_counter,
counters,
&i);
}
}
static inline struct xt_counters * alloc_counters(struct ipt_table *table)
{
unsigned int countersize;
struct xt_counters *counters;
struct xt_table_info *private = table->private;
/* We need atomic snapshot of counters: rest doesn't change
(other than comefrom, which userspace doesn't care
about). */
countersize = sizeof(struct xt_counters) * private->number;
counters = vmalloc_node(countersize, numa_node_id());
if (counters == NULL)
return ERR_PTR(-ENOMEM);
/* First, sum counters... */
write_lock_bh(&table->lock);
get_counters(private, counters);
write_unlock_bh(&table->lock);
return counters;
}
static int
copy_entries_to_user(unsigned int total_size,
struct ipt_table *table,
void __user *userptr)
{
unsigned int off, num;
struct ipt_entry *e;
struct xt_counters *counters;
struct xt_table_info *private = table->private;
int ret = 0;
void *loc_cpu_entry;
counters = alloc_counters(table);
if (IS_ERR(counters))
return PTR_ERR(counters);
/* choose the copy that is on our node/cpu, ...
* This choice is lazy (because current thread is
* allowed to migrate to another cpu)
*/
loc_cpu_entry = private->entries[raw_smp_processor_id()];
/* ... then copy entire thing ... */
if (copy_to_user(userptr, loc_cpu_entry, 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 *)(loc_cpu_entry + 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;
}
#ifdef CONFIG_COMPAT
struct compat_delta {
struct compat_delta *next;
u_int16_t offset;
short delta;
};
static struct compat_delta *compat_offsets = NULL;
static int compat_add_offset(u_int16_t offset, short delta)
{
struct compat_delta *tmp;
tmp = kmalloc(sizeof(struct compat_delta), GFP_KERNEL);
if (!tmp)
return -ENOMEM;
tmp->offset = offset;
tmp->delta = delta;
if (compat_offsets) {
tmp->next = compat_offsets->next;
compat_offsets->next = tmp;
} else {
compat_offsets = tmp;
tmp->next = NULL;
}
return 0;
}
static void compat_flush_offsets(void)
{
struct compat_delta *tmp, *next;
if (compat_offsets) {
for(tmp = compat_offsets; tmp; tmp = next) {
next = tmp->next;
kfree(tmp);
}
compat_offsets = NULL;
}
}
static short compat_calc_jump(u_int16_t offset)
{
struct compat_delta *tmp;
short delta;
for(tmp = compat_offsets, delta = 0; tmp; tmp = tmp->next)
if (tmp->offset < offset)
delta += tmp->delta;
return delta;
}
struct compat_ipt_standard_target
{
struct compat_xt_entry_target target;
compat_int_t verdict;
};
struct compat_ipt_standard
{
struct compat_ipt_entry entry;
struct compat_ipt_standard_target target;
};
#define IPT_ST_LEN XT_ALIGN(sizeof(struct ipt_standard_target))
#define IPT_ST_COMPAT_LEN COMPAT_XT_ALIGN(sizeof(struct compat_ipt_standard_target))
#define IPT_ST_OFFSET (IPT_ST_LEN - IPT_ST_COMPAT_LEN)
static int compat_ipt_standard_fn(void *target,
void **dstptr, int *size, int convert)
{
struct compat_ipt_standard_target compat_st, *pcompat_st;
struct ipt_standard_target st, *pst;
int ret;
ret = 0;
switch (convert) {
case COMPAT_TO_USER:
pst = target;
memcpy(&compat_st.target, &pst->target,
sizeof(compat_st.target));
compat_st.verdict = pst->verdict;
if (compat_st.verdict > 0)
compat_st.verdict -=
compat_calc_jump(compat_st.verdict);
compat_st.target.u.user.target_size = IPT_ST_COMPAT_LEN;
if (copy_to_user(*dstptr, &compat_st, IPT_ST_COMPAT_LEN))
ret = -EFAULT;
*size -= IPT_ST_OFFSET;
*dstptr += IPT_ST_COMPAT_LEN;
break;
case COMPAT_FROM_USER:
pcompat_st = target;
memcpy(&st.target, &pcompat_st->target, IPT_ST_COMPAT_LEN);
st.verdict = pcompat_st->verdict;
if (st.verdict > 0)
st.verdict += compat_calc_jump(st.verdict);
st.target.u.user.target_size = IPT_ST_LEN;
memcpy(*dstptr, &st, IPT_ST_LEN);
*size += IPT_ST_OFFSET;
*dstptr += IPT_ST_LEN;
break;
case COMPAT_CALC_SIZE:
*size += IPT_ST_OFFSET;
break;
default:
ret = -ENOPROTOOPT;
break;
}
return ret;
}
static inline int
compat_calc_match(struct ipt_entry_match *m, int * size)
{
if (m->u.kernel.match->compat)
m->u.kernel.match->compat(m, NULL, size, COMPAT_CALC_SIZE);
else
xt_compat_match(m, NULL, size, COMPAT_CALC_SIZE);
return 0;
}
static int compat_calc_entry(struct ipt_entry *e, struct xt_table_info *info,
void *base, struct xt_table_info *newinfo)
{
struct ipt_entry_target *t;
u_int16_t entry_offset;
int off, i, ret;
off = 0;
entry_offset = (void *)e - base;
IPT_MATCH_ITERATE(e, compat_calc_match, &off);
t = ipt_get_target(e);
if (t->u.kernel.target->compat)
t->u.kernel.target->compat(t, NULL, &off, COMPAT_CALC_SIZE);
else
xt_compat_target(t, NULL, &off, COMPAT_CALC_SIZE);
newinfo->size -= off;
ret = compat_add_offset(entry_offset, off);
if (ret)
return ret;
for (i = 0; i< NF_IP_NUMHOOKS; i++) {
if (info->hook_entry[i] && (e < (struct ipt_entry *)
(base + info->hook_entry[i])))
newinfo->hook_entry[i] -= off;
if (info->underflow[i] && (e < (struct ipt_entry *)
(base + info->underflow[i])))
newinfo->underflow[i] -= off;
}
return 0;
}
static int compat_table_info(struct xt_table_info *info,
struct xt_table_info *newinfo)
{
void *loc_cpu_entry;
int i;
if (!newinfo || !info)
return -EINVAL;
memset(newinfo, 0, sizeof(struct xt_table_info));
newinfo->size = info->size;
newinfo->number = info->number;
for (i = 0; i < NF_IP_NUMHOOKS; i++) {
newinfo->hook_entry[i] = info->hook_entry[i];
newinfo->underflow[i] = info->underflow[i];
}
loc_cpu_entry = info->entries[raw_smp_processor_id()];
return IPT_ENTRY_ITERATE(loc_cpu_entry, info->size,
compat_calc_entry, info, loc_cpu_entry, newinfo);
}
#endif
static int get_info(void __user *user, int *len, int compat)
{
char name[IPT_TABLE_MAXNAMELEN];
struct ipt_table *t;
int ret;
if (*len != sizeof(struct ipt_getinfo)) {
duprintf("length %u != %u\n", *len,
(unsigned int)sizeof(struct ipt_getinfo));
return -EINVAL;
}
if (copy_from_user(name, user, sizeof(name)) != 0)
return -EFAULT;
name[IPT_TABLE_MAXNAMELEN-1] = '\0';
#ifdef CONFIG_COMPAT
if (compat)
xt_compat_lock(AF_INET);
#endif
t = try_then_request_module(xt_find_table_lock(AF_INET, name),
"iptable_%s", name);
if (t && !IS_ERR(t)) {
struct ipt_getinfo info;
struct xt_table_info *private = t->private;
#ifdef CONFIG_COMPAT
if (compat) {
struct xt_table_info tmp;
ret = compat_table_info(private, &tmp);
compat_flush_offsets();
private = &tmp;
}
#endif
info.valid_hooks = t->valid_hooks;
memcpy(info.hook_entry, private->hook_entry,
sizeof(info.hook_entry));
memcpy(info.underflow, private->underflow,
sizeof(info.underflow));
info.num_entries = private->number;
info.size = private->size;
strcpy(info.name, name);
if (copy_to_user(user, &info, *len) != 0)
ret = -EFAULT;
else
ret = 0;
xt_table_unlock(t);
module_put(t->me);
} else
ret = t ? PTR_ERR(t) : -ENOENT;
#ifdef CONFIG_COMPAT
if (compat)
xt_compat_unlock(AF_INET);
#endif
return ret;
}
static int
get_entries(struct ipt_get_entries __user *uptr, int *len)
{
int ret;
struct ipt_get_entries get;
struct ipt_table *t;
if (*len < sizeof(get)) {
duprintf("get_entries: %u < %d\n", *len,
(unsigned int)sizeof(get));
return -EINVAL;
}
if (copy_from_user(&get, uptr, sizeof(get)) != 0)
return -EFAULT;
if (*len != sizeof(struct ipt_get_entries) + get.size) {
duprintf("get_entries: %u != %u\n", *len,
(unsigned int)(sizeof(struct ipt_get_entries) +
get.size));
return -EINVAL;
}
t = xt_find_table_lock(AF_INET, get.name);
if (t && !IS_ERR(t)) {
struct xt_table_info *private = t->private;
duprintf("t->private->number = %u\n",
private->number);
if (get.size == private->size)
ret = copy_entries_to_user(private->size,
t, uptr->entrytable);
else {
duprintf("get_entries: I've got %u not %u!\n",
private->size,
get.size);
ret = -EINVAL;
}
module_put(t->me);
xt_table_unlock(t);
} else
ret = t ? PTR_ERR(t) : -ENOENT;
return ret;
}
static int
__do_replace(const char *name, unsigned int valid_hooks,
struct xt_table_info *newinfo, unsigned int num_counters,
void __user *counters_ptr)
{
int ret;
struct ipt_table *t;
struct xt_table_info *oldinfo;
struct xt_counters *counters;
void *loc_cpu_old_entry;
ret = 0;
counters = vmalloc(num_counters * sizeof(struct xt_counters));
if (!counters) {
ret = -ENOMEM;
goto out;
}
t = try_then_request_module(xt_find_table_lock(AF_INET, name),
"iptable_%s", name);
if (!t || IS_ERR(t)) {
ret = t ? PTR_ERR(t) : -ENOENT;
goto free_newinfo_counters_untrans;
}
/* You lied! */
if (valid_hooks != t->valid_hooks) {
duprintf("Valid hook crap: %08X vs %08X\n",
valid_hooks, t->valid_hooks);
ret = -EINVAL;
goto put_module;
}
oldinfo = xt_replace_table(t, 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 */
loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
IPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,NULL);
xt_free_table_info(oldinfo);
if (copy_to_user(counters_ptr, counters,
sizeof(struct xt_counters) * num_counters) != 0)
ret = -EFAULT;
vfree(counters);
xt_table_unlock(t);
return ret;
put_module:
module_put(t->me);
xt_table_unlock(t);
free_newinfo_counters_untrans:
vfree(counters);
out:
return ret;
}
static int
do_replace(void __user *user, unsigned int len)
{
int ret;
struct ipt_replace tmp;
struct xt_table_info *newinfo;
void *loc_cpu_entry;
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;
/* overflow check */
if (tmp.size >= (INT_MAX - sizeof(struct xt_table_info)) / NR_CPUS -
SMP_CACHE_BYTES)
return -ENOMEM;
if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
return -ENOMEM;
newinfo = xt_alloc_table_info(tmp.size);
if (!newinfo)
return -ENOMEM;
/* choose the copy that is our node/cpu */
loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
tmp.size) != 0) {
ret = -EFAULT;
goto free_newinfo;
}
ret = translate_table(tmp.name, tmp.valid_hooks,
newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
tmp.hook_entry, tmp.underflow);
if (ret != 0)
goto free_newinfo;
duprintf("ip_tables: Translated table\n");
ret = __do_replace(tmp.name, tmp.valid_hooks,
newinfo, tmp.num_counters,
tmp.counters);
if (ret)
goto free_newinfo_untrans;
return 0;
free_newinfo_untrans:
IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL);
free_newinfo:
xt_free_table_info(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 xt_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, int compat)
{
unsigned int i;
struct xt_counters_info tmp;
struct xt_counters *paddc;
unsigned int num_counters;
char *name;
int size;
void *ptmp;
struct ipt_table *t;
struct xt_table_info *private;
int ret = 0;
void *loc_cpu_entry;
#ifdef CONFIG_COMPAT
struct compat_xt_counters_info compat_tmp;
if (compat) {
ptmp = &compat_tmp;
size = sizeof(struct compat_xt_counters_info);
} else
#endif
{
ptmp = &tmp;
size = sizeof(struct xt_counters_info);
}
if (copy_from_user(ptmp, user, size) != 0)
return -EFAULT;
#ifdef CONFIG_COMPAT
if (compat) {
num_counters = compat_tmp.num_counters;
name = compat_tmp.name;
} else
#endif
{
num_counters = tmp.num_counters;
name = tmp.name;
}
if (len != size + num_counters * sizeof(struct xt_counters))
return -EINVAL;
paddc = vmalloc_node(len - size, numa_node_id());
if (!paddc)
return -ENOMEM;
if (copy_from_user(paddc, user + size, len - size) != 0) {
ret = -EFAULT;
goto free;
}
t = xt_find_table_lock(AF_INET, name);
if (!t || IS_ERR(t)) {
ret = t ? PTR_ERR(t) : -ENOENT;
goto free;
}
write_lock_bh(&t->lock);
private = t->private;
if (private->number != num_counters) {
ret = -EINVAL;
goto unlock_up_free;
}
i = 0;
/* Choose the copy that is on our node */
loc_cpu_entry = private->entries[raw_smp_processor_id()];
IPT_ENTRY_ITERATE(loc_cpu_entry,
private->size,
add_counter_to_entry,
paddc,
&i);
unlock_up_free:
write_unlock_bh(&t->lock);
xt_table_unlock(t);
module_put(t->me);
free:
vfree(paddc);
return ret;
}
#ifdef CONFIG_COMPAT
struct compat_ipt_replace {
char name[IPT_TABLE_MAXNAMELEN];
u32 valid_hooks;
u32 num_entries;
u32 size;
u32 hook_entry[NF_IP_NUMHOOKS];
u32 underflow[NF_IP_NUMHOOKS];
u32 num_counters;
compat_uptr_t counters; /* struct ipt_counters * */
struct compat_ipt_entry entries[0];
};
static inline int compat_copy_match_to_user(struct ipt_entry_match *m,
void __user **dstptr, compat_uint_t *size)
{
if (m->u.kernel.match->compat)
return m->u.kernel.match->compat(m, dstptr, size,
COMPAT_TO_USER);
else
return xt_compat_match(m, dstptr, size, COMPAT_TO_USER);
}
static int compat_copy_entry_to_user(struct ipt_entry *e,
void __user **dstptr, compat_uint_t *size)
{
struct ipt_entry_target __user *t;
struct compat_ipt_entry __user *ce;
u_int16_t target_offset, next_offset;
compat_uint_t origsize;
int ret;
ret = -EFAULT;
origsize = *size;
ce = (struct compat_ipt_entry __user *)*dstptr;
if (copy_to_user(ce, e, sizeof(struct ipt_entry)))
goto out;
*dstptr += sizeof(struct compat_ipt_entry);
ret = IPT_MATCH_ITERATE(e, compat_copy_match_to_user, dstptr, size);
target_offset = e->target_offset - (origsize - *size);
if (ret)
goto out;
t = ipt_get_target(e);
if (t->u.kernel.target->compat)
ret = t->u.kernel.target->compat(t, dstptr, size,
COMPAT_TO_USER);
else
ret = xt_compat_target(t, dstptr, size, COMPAT_TO_USER);
if (ret)
goto out;
ret = -EFAULT;
next_offset = e->next_offset - (origsize - *size);
if (put_user(target_offset, &ce->target_offset))
goto out;
if (put_user(next_offset, &ce->next_offset))
goto out;
return 0;
out:
return ret;
}
static inline int
compat_check_calc_match(struct ipt_entry_match *m,
const char *name,
const struct ipt_ip *ip,
unsigned int hookmask,
int *size, int *i)
{
struct ipt_match *match;
match = try_then_request_module(xt_find_match(AF_INET, m->u.user.name,
m->u.user.revision),
"ipt_%s", m->u.user.name);
if (IS_ERR(match) || !match) {
duprintf("compat_check_calc_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->compat)
m->u.kernel.match->compat(m, NULL, size, COMPAT_CALC_SIZE);
else
xt_compat_match(m, NULL, size, COMPAT_CALC_SIZE);
(*i)++;
return 0;
}
static inline int
check_compat_entry_size_and_hooks(struct ipt_entry *e,
struct xt_table_info *newinfo,
unsigned int *size,
unsigned char *base,
unsigned char *limit,
unsigned int *hook_entries,
unsigned int *underflows,
unsigned int *i,
const char *name)
{
struct ipt_entry_target *t;
struct ipt_target *target;
u_int16_t entry_offset;
int ret, off, h, j;
duprintf("check_compat_entry_size_and_hooks %p\n", e);
if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0
|| (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit) {
duprintf("Bad offset %p, limit = %p\n", e, limit);
return -EINVAL;
}
if (e->next_offset < sizeof(struct compat_ipt_entry) +
sizeof(struct compat_xt_entry_target)) {
duprintf("checking: element %p size %u\n",
e, e->next_offset);
return -EINVAL;
}
if (!ip_checkentry(&e->ip)) {
duprintf("ip_tables: ip check failed %p %s.\n", e, name);
return -EINVAL;
}
off = 0;
entry_offset = (void *)e - (void *)base;
j = 0;
ret = IPT_MATCH_ITERATE(e, compat_check_calc_match, name, &e->ip,
e->comefrom, &off, &j);
if (ret != 0)
goto out;
t = ipt_get_target(e);
target = try_then_request_module(xt_find_target(AF_INET,
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 out;
}
t->u.kernel.target = target;
if (t->u.kernel.target->compat)
t->u.kernel.target->compat(t, NULL, &off, COMPAT_CALC_SIZE);
else
xt_compat_target(t, NULL, &off, COMPAT_CALC_SIZE);
*size += off;
ret = compat_add_offset(entry_offset, off);
if (ret)
goto out;
/* 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];
}
/* Clear counters and comefrom */
e->counters = ((struct ipt_counters) { 0, 0 });
e->comefrom = 0;
(*i)++;
return 0;
out:
IPT_MATCH_ITERATE(e, cleanup_match, &j);
return ret;
}
static inline int compat_copy_match_from_user(struct ipt_entry_match *m,
void **dstptr, compat_uint_t *size, const char *name,
const struct ipt_ip *ip, unsigned int hookmask)
{
struct ipt_entry_match *dm;
struct ipt_match *match;
int ret;
dm = (struct ipt_entry_match *)*dstptr;
match = m->u.kernel.match;
if (match->compat)
match->compat(m, dstptr, size, COMPAT_FROM_USER);
else
xt_compat_match(m, dstptr, size, COMPAT_FROM_USER);
ret = xt_check_match(match, AF_INET, dm->u.match_size - sizeof(*dm),
name, hookmask, ip->proto,
ip->invflags & IPT_INV_PROTO);
if (ret)
return ret;
if (m->u.kernel.match->checkentry
&& !m->u.kernel.match->checkentry(name, ip, match, dm->data,
dm->u.match_size - sizeof(*dm),
hookmask)) {
duprintf("ip_tables: check failed for `%s'.\n",
m->u.kernel.match->name);
return -EINVAL;
}
return 0;
}
static int compat_copy_entry_from_user(struct ipt_entry *e, void **dstptr,
unsigned int *size, const char *name,
struct xt_table_info *newinfo, unsigned char *base)
{
struct ipt_entry_target *t;
struct ipt_target *target;
struct ipt_entry *de;
unsigned int origsize;
int ret, h;
ret = 0;
origsize = *size;
de = (struct ipt_entry *)*dstptr;
memcpy(de, e, sizeof(struct ipt_entry));
*dstptr += sizeof(struct compat_ipt_entry);
ret = IPT_MATCH_ITERATE(e, compat_copy_match_from_user, dstptr, size,
name, &de->ip, de->comefrom);
if (ret)
goto out;
de->target_offset = e->target_offset - (origsize - *size);
t = ipt_get_target(e);
target = t->u.kernel.target;
if (target->compat)
target->compat(t, dstptr, size, COMPAT_FROM_USER);
else
xt_compat_target(t, dstptr, size, COMPAT_FROM_USER);
de->next_offset = e->next_offset - (origsize - *size);
for (h = 0; h < NF_IP_NUMHOOKS; h++) {
if ((unsigned char *)de - base < newinfo->hook_entry[h])
newinfo->hook_entry[h] -= origsize - *size;
if ((unsigned char *)de - base < newinfo->underflow[h])
newinfo->underflow[h] -= origsize - *size;
}
t = ipt_get_target(de);
target = t->u.kernel.target;
ret = xt_check_target(target, AF_INET, t->u.target_size - sizeof(*t),
name, e->comefrom, e->ip.proto,
e->ip.invflags & IPT_INV_PROTO);
if (ret)
goto out;
ret = -EINVAL;
if (t->u.kernel.target == &ipt_standard_target) {
if (!standard_check(t, *size))
goto out;
} else if (t->u.kernel.target->checkentry
&& !t->u.kernel.target->checkentry(name, de, target,
t->data, t->u.target_size - sizeof(*t),
de->comefrom)) {
duprintf("ip_tables: compat: check failed for `%s'.\n",
t->u.kernel.target->name);
goto out;
}
ret = 0;
out:
return ret;
}
static int
translate_compat_table(const char *name,
unsigned int valid_hooks,
struct xt_table_info **pinfo,
void **pentry0,
unsigned int total_size,
unsigned int number,
unsigned int *hook_entries,
unsigned int *underflows)
{
unsigned int i;
struct xt_table_info *newinfo, *info;
void *pos, *entry0, *entry1;
unsigned int size;
int ret;
info = *pinfo;
entry0 = *pentry0;
size = total_size;
info->number = number;
/* Init all hooks to impossible value. */
for (i = 0; i < NF_IP_NUMHOOKS; i++) {
info->hook_entry[i] = 0xFFFFFFFF;
info->underflow[i] = 0xFFFFFFFF;
}
duprintf("translate_compat_table: size %u\n", info->size);
i = 0;
xt_compat_lock(AF_INET);
/* Walk through entries, checking offsets. */
ret = IPT_ENTRY_ITERATE(entry0, total_size,
check_compat_entry_size_and_hooks,
info, &size, entry0,
entry0 + total_size,
hook_entries, underflows, &i, name);
if (ret != 0)
goto out_unlock;
ret = -EINVAL;
if (i != number) {
duprintf("translate_compat_table: %u not %u entries\n",
i, number);
goto out_unlock;
}
/* Check hooks all assigned */
for (i = 0; i < NF_IP_NUMHOOKS; i++) {
/* Only hooks which are valid */
if (!(valid_hooks & (1 << i)))
continue;
if (info->hook_entry[i] == 0xFFFFFFFF) {
duprintf("Invalid hook entry %u %u\n",
i, hook_entries[i]);
goto out_unlock;
}
if (info->underflow[i] == 0xFFFFFFFF) {
duprintf("Invalid underflow %u %u\n",
i, underflows[i]);
goto out_unlock;
}
}
ret = -ENOMEM;
newinfo = xt_alloc_table_info(size);
if (!newinfo)
goto out_unlock;
newinfo->number = number;
for (i = 0; i < NF_IP_NUMHOOKS; i++) {
newinfo->hook_entry[i] = info->hook_entry[i];
newinfo->underflow[i] = info->underflow[i];
}
entry1 = newinfo->entries[raw_smp_processor_id()];
pos = entry1;
size = total_size;
ret = IPT_ENTRY_ITERATE(entry0, total_size,
compat_copy_entry_from_user, &pos, &size,
name, newinfo, entry1);
compat_flush_offsets();
xt_compat_unlock(AF_INET);
if (ret)
goto free_newinfo;
ret = -ELOOP;
if (!mark_source_chains(newinfo, valid_hooks, entry1))
goto free_newinfo;
/* And one copy for every other CPU */
for_each_possible_cpu(i)
if (newinfo->entries[i] && newinfo->entries[i] != entry1)
memcpy(newinfo->entries[i], entry1, newinfo->size);
*pinfo = newinfo;
*pentry0 = entry1;
xt_free_table_info(info);
return 0;
free_newinfo:
xt_free_table_info(newinfo);
out:
return ret;
out_unlock:
xt_compat_unlock(AF_INET);
goto out;
}
static int
compat_do_replace(void __user *user, unsigned int len)
{
int ret;
struct compat_ipt_replace tmp;
struct xt_table_info *newinfo;
void *loc_cpu_entry;
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;
/* overflow check */
if (tmp.size >= (INT_MAX - sizeof(struct xt_table_info)) / NR_CPUS -
SMP_CACHE_BYTES)
return -ENOMEM;
if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
return -ENOMEM;
newinfo = xt_alloc_table_info(tmp.size);
if (!newinfo)
return -ENOMEM;
/* choose the copy that is our node/cpu */
loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
tmp.size) != 0) {
ret = -EFAULT;
goto free_newinfo;
}
ret = translate_compat_table(tmp.name, tmp.valid_hooks,
&newinfo, &loc_cpu_entry, tmp.size,
tmp.num_entries, tmp.hook_entry, tmp.underflow);
if (ret != 0)
goto free_newinfo;
duprintf("compat_do_replace: Translated table\n");
ret = __do_replace(tmp.name, tmp.valid_hooks,
newinfo, tmp.num_counters,
compat_ptr(tmp.counters));
if (ret)
goto free_newinfo_untrans;
return 0;
free_newinfo_untrans:
IPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry,NULL);
free_newinfo:
xt_free_table_info(newinfo);
return ret;
}
static int
compat_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 = compat_do_replace(user, len);
break;
case IPT_SO_SET_ADD_COUNTERS:
ret = do_add_counters(user, len, 1);
break;
default:
duprintf("do_ipt_set_ctl: unknown request %i\n", cmd);
ret = -EINVAL;
}
return ret;
}
struct compat_ipt_get_entries
{
char name[IPT_TABLE_MAXNAMELEN];
compat_uint_t size;
struct compat_ipt_entry entrytable[0];
};
static int compat_copy_entries_to_user(unsigned int total_size,
struct ipt_table *table, void __user *userptr)
{
unsigned int off, num;
struct compat_ipt_entry e;
struct xt_counters *counters;
struct xt_table_info *private = table->private;
void __user *pos;
unsigned int size;
int ret = 0;
void *loc_cpu_entry;
counters = alloc_counters(table);
if (IS_ERR(counters))
return PTR_ERR(counters);
/* choose the copy that is on our node/cpu, ...
* This choice is lazy (because current thread is
* allowed to migrate to another cpu)
*/
loc_cpu_entry = private->entries[raw_smp_processor_id()];
pos = userptr;
size = total_size;
ret = IPT_ENTRY_ITERATE(loc_cpu_entry, total_size,
compat_copy_entry_to_user, &pos, &size);
if (ret)
goto free_counters;
/* ... then go back and fix counters and names */
for (off = 0, num = 0; off < size; off += e.next_offset, num++) {
unsigned int i;
struct ipt_entry_match m;
struct ipt_entry_target t;
ret = -EFAULT;
if (copy_from_user(&e, userptr + off,
sizeof(struct compat_ipt_entry)))
goto free_counters;
if (copy_to_user(userptr + off +
offsetof(struct compat_ipt_entry, counters),
&counters[num], sizeof(counters[num])))
goto free_counters;
for (i = sizeof(struct compat_ipt_entry);
i < e.target_offset; i += m.u.match_size) {
if (copy_from_user(&m, userptr + off + i,
sizeof(struct ipt_entry_match)))
goto free_counters;
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))
goto free_counters;
}
if (copy_from_user(&t, userptr + off + e.target_offset,
sizeof(struct ipt_entry_target)))
goto free_counters;
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))
goto free_counters;
}
ret = 0;
free_counters:
vfree(counters);
return ret;
}
static int
compat_get_entries(struct compat_ipt_get_entries __user *uptr, int *len)
{
int ret;
struct compat_ipt_get_entries get;
struct ipt_table *t;
if (*len < sizeof(get)) {
duprintf("compat_get_entries: %u < %u\n",
*len, (unsigned int)sizeof(get));
return -EINVAL;
}
if (copy_from_user(&get, uptr, sizeof(get)) != 0)
return -EFAULT;
if (*len != sizeof(struct compat_ipt_get_entries) + get.size) {
duprintf("compat_get_entries: %u != %u\n", *len,
(unsigned int)(sizeof(struct compat_ipt_get_entries) +
get.size));
return -EINVAL;
}
xt_compat_lock(AF_INET);
t = xt_find_table_lock(AF_INET, get.name);
if (t && !IS_ERR(t)) {
struct xt_table_info *private = t->private;
struct xt_table_info info;
duprintf("t->private->number = %u\n",
private->number);
ret = compat_table_info(private, &info);
if (!ret && get.size == info.size) {
ret = compat_copy_entries_to_user(private->size,
t, uptr->entrytable);
} else if (!ret) {
duprintf("compat_get_entries: I've got %u not %u!\n",
private->size,
get.size);
ret = -EINVAL;
}
compat_flush_offsets();
module_put(t->me);
xt_table_unlock(t);
} else
ret = t ? PTR_ERR(t) : -ENOENT;
xt_compat_unlock(AF_INET);
return ret;
}
static int
compat_do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
{
int ret;
switch (cmd) {
case IPT_SO_GET_INFO:
ret = get_info(user, len, 1);
break;
case IPT_SO_GET_ENTRIES:
ret = compat_get_entries(user, len);
break;
default:
duprintf("compat_do_ipt_get_ctl: unknown request %i\n", cmd);
ret = -EINVAL;
}
return ret;
}
#endif
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, 0);
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:
ret = get_info(user, len, 0);
break;
case IPT_SO_GET_ENTRIES:
ret = get_entries(user, len);
break;
case IPT_SO_GET_REVISION_MATCH:
case IPT_SO_GET_REVISION_TARGET: {
struct ipt_get_revision rev;
int target;
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)
target = 1;
else
target = 0;
try_then_request_module(xt_find_revision(AF_INET, rev.name,
rev.revision,
target, &ret),
"ipt_%s", rev.name);
break;
}
default:
duprintf("do_ipt_get_ctl: unknown request %i\n", cmd);
ret = -EINVAL;
}
return ret;
}
int ipt_register_table(struct xt_table *table, const struct ipt_replace *repl)
{
int ret;
struct xt_table_info *newinfo;
static struct xt_table_info bootstrap
= { 0, 0, 0, { 0 }, { 0 }, { } };
void *loc_cpu_entry;
newinfo = xt_alloc_table_info(repl->size);
if (!newinfo)
return -ENOMEM;
/* choose the copy on our node/cpu
* but dont care of preemption
*/
loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
memcpy(loc_cpu_entry, repl->entries, repl->size);
ret = translate_table(table->name, table->valid_hooks,
newinfo, loc_cpu_entry, repl->size,
repl->num_entries,
repl->hook_entry,
repl->underflow);
if (ret != 0) {
xt_free_table_info(newinfo);
return ret;
}
ret = xt_register_table(table, &bootstrap, newinfo);
if (ret != 0) {
xt_free_table_info(newinfo);
return ret;
}
return 0;
}
void ipt_unregister_table(struct ipt_table *table)
{
struct xt_table_info *private;
void *loc_cpu_entry;
private = xt_unregister_table(table);
/* Decrease module usage counts and free resources */
loc_cpu_entry = private->entries[raw_smp_processor_id()];
IPT_ENTRY_ITERATE(loc_cpu_entry, private->size, cleanup_entry, NULL);
xt_free_table_info(private);
}
/* 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 struct xt_match *match,
const void *matchinfo,
int offset,
unsigned int protoff,
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, protoff, 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 void *info,
const struct xt_match *match,
void *matchinfo,
unsigned int matchsize,
unsigned int hook_mask)
{
const struct ipt_icmp *icmpinfo = matchinfo;
/* Must specify no unknown invflags */
return !(icmpinfo->invflags & ~IPT_ICMP_INV);
}
/* The built-in targets: standard (NULL) and error. */
static struct ipt_target ipt_standard_target = {
.name = IPT_STANDARD_TARGET,
.targetsize = sizeof(int),
.family = AF_INET,
#ifdef CONFIG_COMPAT
.compat = &compat_ipt_standard_fn,
#endif
};
static struct ipt_target ipt_error_target = {
.name = IPT_ERROR_TARGET,
.target = ipt_error,
.targetsize = IPT_FUNCTION_MAXNAMELEN,
.family = AF_INET,
};
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,
#ifdef CONFIG_COMPAT
.compat_set = compat_do_ipt_set_ctl,
#endif
.get_optmin = IPT_BASE_CTL,
.get_optmax = IPT_SO_GET_MAX+1,
.get = do_ipt_get_ctl,
#ifdef CONFIG_COMPAT
.compat_get = compat_do_ipt_get_ctl,
#endif
};
static struct ipt_match icmp_matchstruct = {
.name = "icmp",
.match = icmp_match,
.matchsize = sizeof(struct ipt_icmp),
.proto = IPPROTO_ICMP,
.family = AF_INET,
.checkentry = icmp_checkentry,
};
static int __init ip_tables_init(void)
{
int ret;
xt_proto_init(AF_INET);
/* Noone else will be downing sem now, so we won't sleep */
xt_register_target(&ipt_standard_target);
xt_register_target(&ipt_error_target);
xt_register_match(&icmp_matchstruct);
/* Register setsockopt */
ret = nf_register_sockopt(&ipt_sockopts);
if (ret < 0) {
duprintf("Unable to register sockopts.\n");
return ret;
}
printk("ip_tables: (C) 2000-2006 Netfilter Core Team\n");
return 0;
}
static void __exit ip_tables_fini(void)
{
nf_unregister_sockopt(&ipt_sockopts);
xt_unregister_match(&icmp_matchstruct);
xt_unregister_target(&ipt_error_target);
xt_unregister_target(&ipt_standard_target);
xt_proto_fini(AF_INET);
}
EXPORT_SYMBOL(ipt_register_table);
EXPORT_SYMBOL(ipt_unregister_table);
EXPORT_SYMBOL(ipt_do_table);
module_init(ip_tables_init);
module_exit(ip_tables_fini);
