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* Packet matching code for ARP packets.
*
* Based heavily, if not almost entirely, upon ip_tables.c framework.
*
* Some ARP specific bits are:
*
* Copyright (C) 2002 David S. Miller (davem@redhat.com)
*
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/capability.h>
#include <linux/if_arp.h>
#include <linux/kmod.h>
#include <linux/vmalloc.h>
#include <linux/proc_fs.h>
#include <linux/module.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <asm/semaphore.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_arp/arp_tables.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
MODULE_DESCRIPTION("arptables core");
/*#define DEBUG_ARP_TABLES*/
/*#define DEBUG_ARP_TABLES_USER*/
#ifdef DEBUG_ARP_TABLES
#define dprintf(format, args...) printk(format , ## args)
#else
#define dprintf(format, args...)
#endif
#ifdef DEBUG_ARP_TABLES_USER
#define duprintf(format, args...) printk(format , ## args)
#else
#define duprintf(format, args...)
#endif
#ifdef CONFIG_NETFILTER_DEBUG
#define ARP_NF_ASSERT(x) \
do { \
if (!(x)) \
printk("ARP_NF_ASSERT: %s:%s:%u\n", \
__FUNCTION__, __FILE__, __LINE__); \
} while(0)
#else
#define ARP_NF_ASSERT(x)
#endif
#include <linux/netfilter_ipv4/listhelp.h>
static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
char *hdr_addr, int len)
{
int i, ret;
if (len > ARPT_DEV_ADDR_LEN_MAX)
len = ARPT_DEV_ADDR_LEN_MAX;
ret = 0;
for (i = 0; i < len; i++)
ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
return (ret != 0);
}
/* Returns whether packet matches rule or not. */
static inline int arp_packet_match(const struct arphdr *arphdr,
struct net_device *dev,
const char *indev,
const char *outdev,
const struct arpt_arp *arpinfo)
{
char *arpptr = (char *)(arphdr + 1);
char *src_devaddr, *tgt_devaddr;
u32 src_ipaddr, tgt_ipaddr;
int i, ret;
#define FWINV(bool,invflg) ((bool) ^ !!(arpinfo->invflags & invflg))
if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
ARPT_INV_ARPOP)) {
dprintf("ARP operation field mismatch.\n");
dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
return 0;
}
if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
ARPT_INV_ARPHRD)) {
dprintf("ARP hardware address format mismatch.\n");
dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
return 0;
}
if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
ARPT_INV_ARPPRO)) {
dprintf("ARP protocol address format mismatch.\n");
dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
return 0;
}
if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
ARPT_INV_ARPHLN)) {
dprintf("ARP hardware address length mismatch.\n");
dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
return 0;
}
src_devaddr = arpptr;
arpptr += dev->addr_len;
memcpy(&src_ipaddr, arpptr, sizeof(u32));
arpptr += sizeof(u32);
tgt_devaddr = arpptr;
arpptr += dev->addr_len;
memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
ARPT_INV_SRCDEVADDR) ||
FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
ARPT_INV_TGTDEVADDR)) {
dprintf("Source or target device address mismatch.\n");
return 0;
}
if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
ARPT_INV_SRCIP) ||
FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
ARPT_INV_TGTIP)) {
dprintf("Source or target IP address mismatch.\n");
dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
NIPQUAD(src_ipaddr),
NIPQUAD(arpinfo->smsk.s_addr),
NIPQUAD(arpinfo->src.s_addr),
arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
dprintf("TGT: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
NIPQUAD(tgt_ipaddr),
NIPQUAD(arpinfo->tmsk.s_addr),
NIPQUAD(arpinfo->tgt.s_addr),
arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
return 0;
}
/* Look for ifname matches. */
for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
ret |= (indev[i] ^ arpinfo->iniface[i])
& arpinfo->iniface_mask[i];
}
if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
dprintf("VIA in mismatch (%s vs %s).%s\n",
indev, arpinfo->iniface,
arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
return 0;
}
for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
unsigned long odev;
memcpy(&odev, outdev + i*sizeof(unsigned long),
sizeof(unsigned long));
ret |= (odev
^ ((const unsigned long *)arpinfo->outiface)[i])
& ((const unsigned long *)arpinfo->outiface_mask)[i];
}
if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
dprintf("VIA out mismatch (%s vs %s).%s\n",
outdev, arpinfo->outiface,
arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
return 0;
}
return 1;
}
static inline int arp_checkentry(const struct arpt_arp *arp)
{
if (arp->flags & ~ARPT_F_MASK) {
duprintf("Unknown flag bits set: %08X\n",
arp->flags & ~ARPT_F_MASK);
return 0;
}
if (arp->invflags & ~ARPT_INV_MASK) {
duprintf("Unknown invflag bits set: %08X\n",
arp->invflags & ~ARPT_INV_MASK);
return 0;
}
return 1;
}
static unsigned int arpt_error(struct sk_buff **pskb,
const struct net_device *in,
const struct net_device *out,
unsigned int hooknum,
const void *targinfo,
void *userinfo)
{
if (net_ratelimit())
printk("arp_tables: error: '%s'\n", (char *)targinfo);
return NF_DROP;
}
static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
{
return (struct arpt_entry *)(base + offset);
}
unsigned int arpt_do_table(struct sk_buff **pskb,
unsigned int hook,
const struct net_device *in,
const struct net_device *out,
struct arpt_table *table,
void *userdata)
{
static const char nulldevname[IFNAMSIZ];
unsigned int verdict = NF_DROP;
struct arphdr *arp;
int hotdrop = 0;
struct arpt_entry *e, *back;
const char *indev, *outdev;
void *table_base;
struct xt_table_info *private;
/* ARP header, plus 2 device addresses, plus 2 IP addresses. */
if (!pskb_may_pull((*pskb), (sizeof(struct arphdr) +
(2 * (*pskb)->dev->addr_len) +
(2 * sizeof(u32)))))
return NF_DROP;
indev = in ? in->name : nulldevname;
outdev = out ? out->name : nulldevname;
read_lock_bh(&table->lock);
private = table->private;
table_base = (void *)private->entries[smp_processor_id()];
e = get_entry(table_base, private->hook_entry[hook]);
back = get_entry(table_base, private->underflow[hook]);
arp = (*pskb)->nh.arph;
do {
if (arp_packet_match(arp, (*pskb)->dev, indev, outdev, &e->arp)) {
struct arpt_entry_target *t;
int hdr_len;
hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
(2 * (*pskb)->dev->addr_len);
ADD_COUNTER(e->counters, hdr_len, 1);
t = arpt_get_target(e);
/* Standard target? */
if (!t->u.kernel.target->target) {
int v;
v = ((struct arpt_standard_target *)t)->verdict;
if (v < 0) {
/* Pop from stack? */
if (v != ARPT_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) {
/* Save old back ptr in next entry */
struct arpt_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
*/
verdict = t->u.kernel.target->target(pskb,
in, out,
hook,
t->data,
userdata);
/* Target might have changed stuff. */
arp = (*pskb)->nh.arph;
if (verdict == ARPT_CONTINUE)
e = (void *)e + e->next_offset;
else
/* Verdict */
break;
}
} else {
e = (void *)e + e->next_offset;
}
} while (!hotdrop);
read_unlock_bh(&table->lock);
if (hotdrop)
return NF_DROP;
else
return verdict;
}
/* All zeroes == unconditional rule. */
static inline int unconditional(const struct arpt_arp *arp)
{
unsigned int i;
for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
if (((__u32 *)arp)[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_ARP_NUMHOOKS; hook++) {
unsigned int pos = newinfo->hook_entry[hook];
struct arpt_entry *e
= (struct arpt_entry *)(entry0 + pos);
if (!(valid_hooks & (1 << hook)))
continue;
/* Set initial back pointer. */
e->counters.pcnt = pos;
for (;;) {
struct arpt_standard_target *t
= (void *)arpt_get_target(e);
if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
printk("arptables: loop hook %u pos %u %08X.\n",
hook, pos, e->comefrom);
return 0;
}
e->comefrom
|= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
/* Unconditional return/END. */
if (e->target_offset == sizeof(struct arpt_entry)
&& (strcmp(t->target.u.user.name,
ARPT_STANDARD_TARGET) == 0)
&& t->verdict < 0
&& unconditional(&e->arp)) {
unsigned int oldpos, size;
/* Return: backtrack through the last
* big jump.
*/
do {
e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
oldpos = pos;
pos = e->counters.pcnt;
e->counters.pcnt = 0;
/* We're at the start. */
if (pos == oldpos)
goto next;
e = (struct arpt_entry *)
(entry0 + pos);
} while (oldpos == pos + e->next_offset);
/* Move along one */
size = e->next_offset;
e = (struct arpt_entry *)
(entry0 + pos + size);
e->counters.pcnt = pos;
pos += size;
} else {
int newpos = t->verdict;
if (strcmp(t->target.u.user.name,
ARPT_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 arpt_entry *)
(entry0 + newpos);
e->counters.pcnt = pos;
pos = newpos;
}
}
next:
duprintf("Finished chain %u\n", hook);
}
return 1;
}
static inline int standard_check(const struct arpt_entry_target *t,
unsigned int max_offset)
{
struct arpt_standard_target *targ = (void *)t;
/* Check standard info. */
if (t->u.target_size
!= ARPT_ALIGN(sizeof(struct arpt_standard_target))) {
duprintf("arpt_standard_check: target size %u != %Zu\n",
t->u.target_size,
ARPT_ALIGN(sizeof(struct arpt_standard_target)));
return 0;
}
if (targ->verdict >= 0
&& targ->verdict > max_offset - sizeof(struct arpt_entry)) {
duprintf("arpt_standard_check: bad verdict (%i)\n",
targ->verdict);
return 0;
}
if (targ->verdict < -NF_MAX_VERDICT - 1) {
duprintf("arpt_standard_check: bad negative verdict (%i)\n",
targ->verdict);
return 0;
}
return 1;
}
static struct arpt_target arpt_standard_target;
static inline int check_entry(struct arpt_entry *e, const char *name, unsigned int size,
unsigned int *i)
{
struct arpt_entry_target *t;
struct arpt_target *target;
int ret;
if (!arp_checkentry(&e->arp)) {
duprintf("arp_tables: arp check failed %p %s.\n", e, name);
return -EINVAL;
}
t = arpt_get_target(e);
target = try_then_request_module(xt_find_target(NF_ARP, t->u.user.name,
t->u.user.revision),
"arpt_%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 == &arpt_standard_target) {
if (!standard_check(t, size)) {
ret = -EINVAL;
goto out;
}
} 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("arp_tables: check failed for `%s'.\n",
t->u.kernel.target->name);
ret = -EINVAL;
goto out;
}
(*i)++;
return 0;
out:
return ret;
}
static inline int check_entry_size_and_hooks(struct arpt_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 arpt_entry) != 0
|| (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
duprintf("Bad offset %p\n", e);
return -EINVAL;
}
if (e->next_offset
< sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) {
duprintf("checking: element %p size %u\n",
e, e->next_offset);
return -EINVAL;
}
/* Check hooks & underflows */
for (h = 0; h < NF_ARP_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 ARPT_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 arpt_entry *e, unsigned int *i)
{
struct arpt_entry_target *t;
if (i && (*i)-- == 0)
return 1;
t = arpt_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 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_ARP_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 = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
check_entry_size_and_hooks,
newinfo,
entry0,
entry0 + size,
hook_entries, underflows, &i);
duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
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_ARP_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)) {
duprintf("Looping hook\n");
return -ELOOP;
}
/* Finally, each sanity check must pass */
i = 0;
ret = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
check_entry, name, size, &i);
if (ret != 0) {
ARPT_ENTRY_ITERATE(entry0, newinfo->size,
cleanup_entry, &i);
return ret;
}
/* And one copy for every other CPU */
for_each_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 arpt_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 arpt_entry *e,
struct xt_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;
ARPT_ENTRY_ITERATE(t->entries[curcpu],
t->size,
set_entry_to_counter,
counters,
&i);
for_each_cpu(cpu) {
if (cpu == curcpu)
continue;
i = 0;
ARPT_ENTRY_ITERATE(t->entries[cpu],
t->size,
add_entry_to_counter,
counters,
&i);
}
}
static int copy_entries_to_user(unsigned int total_size,
struct arpt_table *table,
void __user *userptr)
{
unsigned int off, num, countersize;
struct arpt_entry *e;
struct xt_counters *counters;
struct xt_table_info *private = table->private;
int ret = 0;
void *loc_cpu_entry;
/* 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 -ENOMEM;
/* First, sum counters... */
write_lock_bh(&table->lock);
get_counters(private, counters);
write_unlock_bh(&table->lock);
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++){
struct arpt_entry_target *t;
e = (struct arpt_entry *)(loc_cpu_entry + off);
if (copy_to_user(userptr + off
+ offsetof(struct arpt_entry, counters),
&counters[num],
sizeof(counters[num])) != 0) {
ret = -EFAULT;
goto free_counters;
}
t = arpt_get_target(e);
if (copy_to_user(userptr + off + e->target_offset
+ offsetof(struct arpt_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 arpt_get_entries *entries,
struct arpt_get_entries __user *uptr)
{
int ret;
struct arpt_table *t;
t = xt_find_table_lock(NF_ARP, entries->name);
if (t && !IS_ERR(t)) {
struct xt_table_info *private = t->private;
duprintf("t->private->number = %u\n",
private->number);
if (entries->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, entries->size);
ret = -EINVAL;
}
module_put(t->me);
xt_table_unlock(t);
} else
ret = t ? PTR_ERR(t) : -ENOENT;
return ret;
}
static int do_replace(void __user *user, unsigned int len)
{
int ret;
struct arpt_replace tmp;
struct arpt_table *t;
struct xt_table_info *newinfo, *oldinfo;
struct xt_counters *counters;
void *loc_cpu_entry, *loc_cpu_old_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 on 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;
}
counters = vmalloc(tmp.num_counters * sizeof(struct xt_counters));
if (!counters) {
ret = -ENOMEM;
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_counters;
duprintf("arp_tables: Translated table\n");
t = try_then_request_module(xt_find_table_lock(NF_ARP, tmp.name),
"arptable_%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 = xt_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 */
loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
ARPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,NULL);
xt_free_table_info(oldinfo);
if (copy_to_user(tmp.counters, counters,
sizeof(struct xt_counters) * tmp.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:
ARPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
free_newinfo_counters:
vfree(counters);
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 arpt_entry *e,
const struct xt_counters addme[],
unsigned int *i)
{
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 xt_counters_info tmp, *paddc;
struct arpt_table *t;
struct xt_table_info *private;
int ret = 0;
void *loc_cpu_entry;
if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
return -EFAULT;
if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct xt_counters))
return -EINVAL;
paddc = vmalloc(len);
if (!paddc)
return -ENOMEM;
if (copy_from_user(paddc, user, len) != 0) {
ret = -EFAULT;
goto free;
}
t = xt_find_table_lock(NF_ARP, tmp.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 != tmp.num_counters) {
ret = -EINVAL;
goto unlock_up_free;
}
i = 0;
/* Choose the copy that is on our node */
loc_cpu_entry = private->entries[smp_processor_id()];
ARPT_ENTRY_ITERATE(loc_cpu_entry,
private->size,
add_counter_to_entry,
paddc->counters,
&i);
unlock_up_free:
write_unlock_bh(&t->lock);
xt_table_unlock(t);
module_put(t->me);
free:
vfree(paddc);
return ret;
}
static int do_arpt_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 ARPT_SO_SET_REPLACE:
ret = do_replace(user, len);
break;
case ARPT_SO_SET_ADD_COUNTERS:
ret = do_add_counters(user, len);
break;
default:
duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
ret = -EINVAL;
}
return ret;
}
static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
{
int ret;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
switch (cmd) {
case ARPT_SO_GET_INFO: {
char name[ARPT_TABLE_MAXNAMELEN];
struct arpt_table *t;
if (*len != sizeof(struct arpt_getinfo)) {
duprintf("length %u != %Zu\n", *len,
sizeof(struct arpt_getinfo));
ret = -EINVAL;
break;
}
if (copy_from_user(name, user, sizeof(name)) != 0) {
ret = -EFAULT;
break;
}
name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
t = try_then_request_module(xt_find_table_lock(NF_ARP, name),
"arptable_%s", name);
if (t && !IS_ERR(t)) {
struct arpt_getinfo info;
struct xt_table_info *private = t->private;
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;
}
break;
case ARPT_SO_GET_ENTRIES: {
struct arpt_get_entries get;
if (*len < sizeof(get)) {
duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
ret = -EINVAL;
} else if (copy_from_user(&get, user, sizeof(get)) != 0) {
ret = -EFAULT;
} else if (*len != sizeof(struct arpt_get_entries) + get.size) {
duprintf("get_entries: %u != %Zu\n", *len,
sizeof(struct arpt_get_entries) + get.size);
ret = -EINVAL;
} else
ret = get_entries(&get, user);
break;
}
case ARPT_SO_GET_REVISION_TARGET: {
struct xt_get_revision rev;
if (*len != sizeof(rev)) {
ret = -EINVAL;
break;
}
if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
ret = -EFAULT;
break;
}
try_then_request_module(xt_find_revision(NF_ARP, rev.name,
rev.revision, 1, &ret),
"arpt_%s", rev.name);
break;
}
default:
duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
ret = -EINVAL;
}
return ret;
}
int arpt_register_table(struct arpt_table *table,
const struct arpt_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) {
ret = -ENOMEM;
return ret;
}
/* choose the copy on our node/cpu */
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);
duprintf("arpt_register_table: translate table gives %d\n", ret);
if (ret != 0) {
xt_free_table_info(newinfo);
return ret;
}
if (xt_register_table(table, &bootstrap, newinfo) != 0) {
xt_free_table_info(newinfo);
return ret;
}
return 0;
}
void arpt_unregister_table(struct arpt_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()];
ARPT_ENTRY_ITERATE(loc_cpu_entry, private->size,
cleanup_entry, NULL);
xt_free_table_info(private);
}
/* The built-in targets: standard (NULL) and error. */
static struct arpt_target arpt_standard_target = {
.name = ARPT_STANDARD_TARGET,
};
static struct arpt_target arpt_error_target = {
.name = ARPT_ERROR_TARGET,
.target = arpt_error,
};
static struct nf_sockopt_ops arpt_sockopts = {
.pf = PF_INET,
.set_optmin = ARPT_BASE_CTL,
.set_optmax = ARPT_SO_SET_MAX+1,
.set = do_arpt_set_ctl,
.get_optmin = ARPT_BASE_CTL,
.get_optmax = ARPT_SO_GET_MAX+1,
.get = do_arpt_get_ctl,
};
static int __init init(void)
{
int ret;
xt_proto_init(NF_ARP);
/* Noone else will be downing sem now, so we won't sleep */
xt_register_target(NF_ARP, &arpt_standard_target);
xt_register_target(NF_ARP, &arpt_error_target);
/* Register setsockopt */
ret = nf_register_sockopt(&arpt_sockopts);
if (ret < 0) {
duprintf("Unable to register sockopts.\n");
return ret;
}
printk("arp_tables: (C) 2002 David S. Miller\n");
return 0;
}
static void __exit fini(void)
{
nf_unregister_sockopt(&arpt_sockopts);
xt_proto_fini(NF_ARP);
}
EXPORT_SYMBOL(arpt_register_table);
EXPORT_SYMBOL(arpt_unregister_table);
EXPORT_SYMBOL(arpt_do_table);
module_init(init);
module_exit(fini);
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