/*
* 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)
* Copyright (C) 2006-2009 Patrick McHardy <kaber@trash.net>
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#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 <linux/mutex.h>
#include <linux/err.h>
#include <net/compat.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_arp/arp_tables.h>
#include "../../netfilter/xt_repldata.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) WARN_ON(!(x))
#else
#define ARP_NF_ASSERT(x)
#endif
void *arpt_alloc_initial_table(const struct xt_table *info)
{
return xt_alloc_initial_table(arpt, ARPT);
}
EXPORT_SYMBOL_GPL(arpt_alloc_initial_table);
static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
const 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;
}
/*
* Unfortunately, _b and _mask are not aligned to an int (or long int)
* Some arches dont care, unrolling the loop is a win on them.
* For other arches, we only have a 16bit alignement.
*/
static unsigned long ifname_compare(const char *_a, const char *_b, const char *_mask)
{
#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
unsigned long ret = ifname_compare_aligned(_a, _b, _mask);
#else
unsigned long ret = 0;
const u16 *a = (const u16 *)_a;
const u16 *b = (const u16 *)_b;
const u16 *mask = (const u16 *)_mask;
int i;
for (i = 0; i < IFNAMSIZ/sizeof(u16); i++)
ret |= (a[i] ^ b[i]) & mask[i];
#endif
return ret;
}
/* 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)
{
const char *arpptr = (char *)(arphdr + 1);
const char *src_devaddr, *tgt_devaddr;
__be32 src_ipaddr, tgt_ipaddr;
long 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: %pI4. Mask: %pI4. Target: %pI4.%s\n",
&src_ipaddr,
&arpinfo->smsk.s_addr,
&arpinfo->src.s_addr,
arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
dprintf("TGT: %pI4 Mask: %pI4 Target: %pI4.%s\n",
&tgt_ipaddr,
&arpinfo->tmsk.s_addr,
&arpinfo->tgt.s_addr,
arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
return 0;
}
/* Look for ifname matches. */
ret = ifname_compare(indev, arpinfo->iniface, arpinfo->iniface_mask);
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;
}
ret = ifname_compare(outdev, arpinfo->outiface, arpinfo->outiface_mask);
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;
#undef FWINV
}
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 *skb, const struct xt_action_param *par)
{
net_err_ratelimited("arp_tables: error: '%s'\n",
(const char *)par->targinfo);
return NF_DROP;
}
static inline const struct xt_entry_target *
arpt_get_target_c(const struct arpt_entry *e)
{
return arpt_get_target((struct arpt_entry *)e);
}
static inline struct arpt_entry *
get_entry(const void *base, unsigned int offset)
{
return (struct arpt_entry *)(base + offset);
}
static inline __pure
struct arpt_entry *arpt_next_entry(const struct arpt_entry *entry)
{
return (void *)entry + entry->next_offset;
}
unsigned int arpt_do_table(struct sk_buff *skb,
unsigned int hook,
const struct nf_hook_state *state,
struct xt_table *table)
{
static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
unsigned int verdict = NF_DROP;
const struct arphdr *arp;
struct arpt_entry *e, *back;
const char *indev, *outdev;
void *table_base;
const struct xt_table_info *private;
struct xt_action_param acpar;
unsigned int addend;
if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
return NF_DROP;
indev = state->in ? state->in->name : nulldevname;
outdev = state->out ? state->out->name : nulldevname;
local_bh_disable();
addend = xt_write_recseq_begin();
private = table->private;
/*
* Ensure we load private-> members after we've fetched the base
* pointer.
*/
smp_read_barrier_depends();
table_base = private->entries[smp_processor_id()];
e = get_entry(table_base, private->hook_entry[hook]);
back = get_entry(table_base, private->underflow[hook]);
acpar.in = state->in;
acpar.out = state->out;
acpar.hooknum = hook;
acpar.family = NFPROTO_ARP;
acpar.hotdrop = false;
arp = arp_hdr(skb);
do {
const struct xt_entry_target *t;
if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
e = arpt_next_entry(e);
continue;
}
ADD_COUNTER(e->counters, arp_hdr_len(skb->dev), 1);
t = arpt_get_target_c(e);
/* Standard target? */
if (!t->u.kernel.target->target) {
int v;
v = ((struct xt_standard_target *)t)->verdict;
if (v < 0) {
/* Pop from stack? */
if (v != XT_RETURN) {
verdict = (unsigned int)(-v) - 1;
break;
}
e = back;
back = get_entry(table_base, back->comefrom);
continue;
}
if (table_base + v
!= arpt_next_entry(e)) {
/* Save old back ptr in next entry */
struct arpt_entry *next = arpt_next_entry(e);
next->comefrom = (void *)back - table_base;
/* set back pointer to next entry */
back = next;
}
e = get_entry(table_base, v);
continue;
}
/* Targets which reenter must return
* abs. verdicts
*/
acpar.target = t->u.kernel.target;
acpar.targinfo = t->data;
verdict = t->u.kernel.target->target(skb, &acpar);
/* Target might have changed stuff. */
arp = arp_hdr(skb);
if (verdict == XT_CONTINUE)
e = arpt_next_entry(e);
else
/* Verdict */
break;
} while (!acpar.hotdrop);
xt_write_recseq_end(addend);
local_bh_enable();
if (acpar.hotdrop)
return NF_DROP;
else
return verdict;
}
/* All zeroes == unconditional rule. */
static inline bool unconditional(const struct arpt_arp *arp)
{
static const struct arpt_arp uncond;
return memcmp(arp, &uncond, sizeof(uncond)) == 0;
}
/* 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(const 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 (;;) {
const struct xt_standard_target *t
= (void *)arpt_get_target_c(e);
int visited = e->comefrom & (1 << hook);
if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
pr_notice("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,
XT_STANDARD_TARGET) == 0) &&
t->verdict < 0 && unconditional(&e->arp)) ||
visited) {
unsigned int oldpos, size;
if ((strcmp(t->target.u.user.name,
XT_STANDARD_TARGET) == 0) &&
t->verdict < -NF_MAX_VERDICT - 1) {
duprintf("mark_source_chains: bad "
"negative verdict (%i)\n",
t->verdict);
return 0;
}
/* 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,
XT_STANDARD_TARGET) == 0 &&
newpos >= 0) {
if (newpos > newinfo->size -
sizeof(struct arpt_entry)) {
duprintf("mark_source_chains: "
"bad verdict (%i)\n",
newpos);
return 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 check_entry(const struct arpt_entry *e, const char *name)
{
const struct xt_entry_target *t;
if (!arp_checkentry(&e->arp)) {
duprintf("arp_tables: arp check failed %p %s.\n", e, name);
return -EINVAL;
}
if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset)
return -EINVAL;
t = arpt_get_target_c(e);
if (e->target_offset + t->u.target_size > e->next_offset)
return -EINVAL;
return 0;
}
static inline int check_target(struct arpt_entry *e, const char *name)
{
struct xt_entry_target *t = arpt_get_target(e);
int ret;
struct xt_tgchk_param par = {
.table = name,
.entryinfo = e,
.target = t->u.kernel.target,
.targinfo = t->data,
.hook_mask = e->comefrom,
.family = NFPROTO_ARP,
};
ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
if (ret < 0) {
duprintf("arp_tables: check failed for `%s'.\n",
t->u.kernel.target->name);
return ret;
}
return 0;
}
static inline int
find_check_entry(struct arpt_entry *e, const char *name, unsigned int size)
{
struct xt_entry_target *t;
struct xt_target *target;
int ret;
ret = check_entry(e, name);
if (ret)
return ret;
t = arpt_get_target(e);
target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
t->u.user.revision);
if (IS_ERR(target)) {
duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
ret = PTR_ERR(target);
goto out;
}
t->u.kernel.target = target;
ret = check_target(e, name);
if (ret)
goto err;
return 0;
err:
module_put(t->u.kernel.target->me);
out:
return ret;
}
static bool check_underflow(const struct arpt_entry *e)
{
const struct xt_entry_target *t;
unsigned int verdict;
if (!unconditional(&e->arp))
return false;
t = arpt_get_target_c(e);
if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
return false;
verdict = ((struct xt_standard_target *)t)->verdict;
verdict = -verdict - 1;
return verdict == NF_DROP || verdict == NF_ACCEPT;
}
static inline int check_entry_size_and_hooks(struct arpt_entry *e,
struct xt_table_info *newinfo,
const unsigned char *base,
const unsigned char *limit,
const unsigned int *hook_entries,
const unsigned int *underflows,
unsigned int valid_hooks)
{
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 xt_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 (!(valid_hooks & (1 << h)))
continue;
if ((unsigned char *)e - base == hook_entries[h])
newinfo->hook_entry[h] = hook_entries[h];
if ((unsigned char *)e - base == underflows[h]) {
if (!check_underflow(e)) {
pr_err("Underflows must be unconditional and "
"use the STANDARD target with "
"ACCEPT/DROP\n");
return -EINVAL;
}
newinfo->underflow[h] = underflows[h];
}
}
/* Clear counters and comefrom */
e->counters = ((struct xt_counters) { 0, 0 });
e->comefrom = 0;
return 0;
}
static inline void cleanup_entry(struct arpt_entry *e)
{
struct xt_tgdtor_param par;
struct xt_entry_target *t;
t = arpt_get_target(e);
par.target = t->u.kernel.target;
par.targinfo = t->data;
par.family = NFPROTO_ARP;
if (par.target->destroy != NULL)
par.target->destroy(&par);
module_put(par.target->me);
}
/* Checks and translates the user-supplied table segment (held in
* newinfo).
*/
static int translate_table(struct xt_table_info *newinfo, void *entry0,
const struct arpt_replace *repl)
{
struct arpt_entry *iter;
unsigned int i;
int ret = 0;
newinfo->size = repl->size;
newinfo->number = repl->num_entries;
/* 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. */
xt_entry_foreach(iter, entry0, newinfo->size) {
ret = check_entry_size_and_hooks(iter, newinfo, entry0,
entry0 + repl->size,
repl->hook_entry,
repl->underflow,
repl->valid_hooks);
if (ret != 0)
break;
++i;
if (strcmp(arpt_get_target(iter)->u.user.name,
XT_ERROR_TARGET) == 0)
++newinfo->stacksize;
}
duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
if (ret != 0)
return ret;
if (i != repl->num_entries) {
duprintf("translate_table: %u not %u entries\n",
i, repl->num_entries);
return -EINVAL;
}
/* Check hooks all assigned */
for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
/* Only hooks which are valid */
if (!(repl->valid_hooks & (1 << i)))
continue;
if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
duprintf("Invalid hook entry %u %u\n",
i, repl->hook_entry[i]);
return -EINVAL;
}
if (newinfo->underflow[i] == 0xFFFFFFFF) {
duprintf("Invalid underflow %u %u\n",
i, repl->underflow[i]);
return -EINVAL;
}
}
if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) {
duprintf("Looping hook\n");
return -ELOOP;
}
/* Finally, each sanity check must pass */
i = 0;
xt_entry_foreach(iter, entry0, newinfo->size) {
ret = find_check_entry(iter, repl->name, repl->size);
if (ret != 0)
break;
++i;
}
if (ret != 0) {
xt_entry_foreach(iter, entry0, newinfo->size) {
if (i-- == 0)
break;
cleanup_entry(iter);
}
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;
}
static void get_counters(const struct xt_table_info *t,
struct xt_counters counters[])
{
struct arpt_entry *iter;
unsigned int cpu;
unsigned int i;
for_each_possible_cpu(cpu) {
seqcount_t *s = &per_cpu(xt_recseq, cpu);
i = 0;
xt_entry_foreach(iter, t->entries[cpu], t->size) {
u64 bcnt, pcnt;
unsigned int start;
do {
start = read_seqcount_begin(s);
bcnt = iter->counters.bcnt;
pcnt = iter->counters.pcnt;
} while (read_seqcount_retry(s, start));
ADD_COUNTER(counters[i], bcnt, pcnt);
++i;
}
}
}
static struct xt_counters *alloc_counters(const struct xt_table *table)
{
unsigned int countersize;
struct xt_counters *counters;
const 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 = vzalloc(countersize);
if (counters == NULL)
return ERR_PTR(-ENOMEM);
get_counters(private, counters);
return counters;
}
static int copy_entries_to_user(unsigned int total_size,
const struct xt_table *table,
void __user *userptr)
{
unsigned int off, num;
const struct arpt_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);
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++){
const struct xt_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_c(e);
if (copy_to_user(userptr + off + e->target_offset
+ offsetof(struct xt_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
static void compat_standard_from_user(void *dst, const void *src)
{
int v = *(compat_int_t *)src;
if (v > 0)
v += xt_compat_calc_jump(NFPROTO_ARP, v);
memcpy(dst, &v, sizeof(v));
}
static int compat_standard_to_user(void __user *dst, const void *src)
{
compat_int_t cv = *(int *)src;
if (cv > 0)
cv -= xt_compat_calc_jump(NFPROTO_ARP, cv);
return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
}
static int compat_calc_entry(const struct arpt_entry *e,
const struct xt_table_info *info,
const void *base, struct xt_table_info *newinfo)
{
const struct xt_entry_target *t;
unsigned int entry_offset;
int off, i, ret;
off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
entry_offset = (void *)e - base;
t = arpt_get_target_c(e);
off += xt_compat_target_offset(t->u.kernel.target);
newinfo->size -= off;
ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
if (ret)
return ret;
for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
if (info->hook_entry[i] &&
(e < (struct arpt_entry *)(base + info->hook_entry[i])))
newinfo->hook_entry[i] -= off;
if (info->underflow[i] &&
(e < (struct arpt_entry *)(base + info->underflow[i])))
newinfo->underflow[i] -= off;
}
return 0;
}
static int compat_table_info(const struct xt_table_info *info,
struct xt_table_info *newinfo)
{
struct arpt_entry *iter;
void *loc_cpu_entry;
int ret;
if (!newinfo || !info)
return -EINVAL;
/* we dont care about newinfo->entries[] */
memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
newinfo->initial_entries = 0;
loc_cpu_entry = info->entries[raw_smp_processor_id()];
xt_compat_init_offsets(NFPROTO_ARP, info->number);
xt_entry_foreach(iter, loc_cpu_entry, info->size) {
ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
if (ret != 0)
return ret;
}
return 0;
}
#endif
static int get_info(struct net *net, void __user *user,
const int *len, int compat)
{
char name[XT_TABLE_MAXNAMELEN];
struct xt_table *t;
int ret;
if (*len != sizeof(struct arpt_getinfo)) {
duprintf("length %u != %Zu\n", *len,
sizeof(struct arpt_getinfo));
return -EINVAL;
}
if (copy_from_user(name, user, sizeof(name)) != 0)
return -EFAULT;
name[XT_TABLE_MAXNAMELEN-1] = '\0';
#ifdef CONFIG_COMPAT
if (compat)
xt_compat_lock(NFPROTO_ARP);
#endif
t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
"arptable_%s", name);
if (!IS_ERR_OR_NULL(t)) {
struct arpt_getinfo info;
const struct xt_table_info *private = t->private;
#ifdef CONFIG_COMPAT
struct xt_table_info tmp;
if (compat) {
ret = compat_table_info(private, &tmp);
xt_compat_flush_offsets(NFPROTO_ARP);
private = &tmp;
}
#endif
memset(&info, 0, sizeof(info));
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(NFPROTO_ARP);
#endif
return ret;
}
static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
const int *len)
{
int ret;
struct arpt_get_entries get;
struct xt_table *t;
if (*len < sizeof(get)) {
duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
return -EINVAL;
}
if (copy_from_user(&get, uptr, sizeof(get)) != 0)
return -EFAULT;
if (*len != sizeof(struct arpt_get_entries) + get.size) {
duprintf("get_entries: %u != %Zu\n", *len,
sizeof(struct arpt_get_entries) + get.size);
return -EINVAL;
}
t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
if (!IS_ERR_OR_NULL(t)) {
const 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 = -EAGAIN;
}
module_put(t->me);
xt_table_unlock(t);
} else
ret = t ? PTR_ERR(t) : -ENOENT;
return ret;
}
static int __do_replace(struct net *net, const char *name,
unsigned int valid_hooks,
struct xt_table_info *newinfo,
unsigned int num_counters,
void __user *counters_ptr)
{
int ret;
struct xt_table *t;
struct xt_table_info *oldinfo;
struct xt_counters *counters;
void *loc_cpu_old_entry;
struct arpt_entry *iter;
ret = 0;
counters = vzalloc(num_counters * sizeof(struct xt_counters));
if (!counters) {
ret = -ENOMEM;
goto out;
}
t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
"arptable_%s", name);
if (IS_ERR_OR_NULL(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, and synchronize with replace */
get_counters(oldinfo, counters);
/* Decrease module usage counts and free resource */
loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
cleanup_entry(iter);
xt_free_table_info(oldinfo);
if (copy_to_user(counters_ptr, counters,
sizeof(struct xt_counters) * num_counters) != 0) {
/* Silent error, can't fail, new table is already in place */
net_warn_ratelimited("arptables: counters copy to user failed while replacing table\n");
}
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(struct net *net, const void __user *user,
unsigned int len)
{
int ret;
struct arpt_replace tmp;
struct xt_table_info *newinfo;
void *loc_cpu_entry;
struct arpt_entry *iter;
if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
return -EFAULT;
/* overflow check */
if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
return -ENOMEM;
if (tmp.num_counters == 0)
return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0;
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;
}
ret = translate_table(newinfo, loc_cpu_entry, &tmp);
if (ret != 0)
goto free_newinfo;
duprintf("arp_tables: Translated table\n");
ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
tmp.num_counters, tmp.counters);
if (ret)
goto free_newinfo_untrans;
return 0;
free_newinfo_untrans:
xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
cleanup_entry(iter);
free_newinfo:
xt_free_table_info(newinfo);
return ret;
}
static int do_add_counters(struct net *net, const void __user *user,
unsigned int len, int compat)
{
unsigned int i, curcpu;
struct xt_counters_info tmp;
struct xt_counters *paddc;
unsigned int num_counters;
const char *name;
int size;
void *ptmp;
struct xt_table *t;
const struct xt_table_info *private;
int ret = 0;
void *loc_cpu_entry;
struct arpt_entry *iter;
unsigned int addend;
#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(len - size);
if (!paddc)
return -ENOMEM;
if (copy_from_user(paddc, user + size, len - size) != 0) {
ret = -EFAULT;
goto free;
}
t = xt_find_table_lock(net, NFPROTO_ARP, name);
if (IS_ERR_OR_NULL(t)) {
ret = t ? PTR_ERR(t) : -ENOENT;
goto free;
}
local_bh_disable();
private = t->private;
if (private->number != num_counters) {
ret = -EINVAL;
goto unlock_up_free;
}
i = 0;
/* Choose the copy that is on our node */
curcpu = smp_processor_id();
loc_cpu_entry = private->entries[curcpu];
addend = xt_write_recseq_begin();
xt_entry_foreach(iter, loc_cpu_entry, private->size) {
ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt);
++i;
}
xt_write_recseq_end(addend);
unlock_up_free:
local_bh_enable();
xt_table_unlock(t);
module_put(t->me);
free:
vfree(paddc);
return ret;
}
#ifdef CONFIG_COMPAT
static inline void compat_release_entry(struct compat_arpt_entry *e)
{
struct xt_entry_target *t;
t = compat_arpt_get_target(e);
module_put(t->u.kernel.target->me);
}
static inline int
check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
struct xt_table_info *newinfo,
unsigned int *size,
const unsigned char *base,
const unsigned char *limit,
const unsigned int *hook_entries,
const unsigned int *underflows,
const char *name)
{
struct xt_entry_target *t;
struct xt_target *target;
unsigned int entry_offset;
int ret, off, h;
duprintf("check_compat_entry_size_and_hooks %p\n", e);
if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 ||
(unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
duprintf("Bad offset %p, limit = %p\n", e, limit);
return -EINVAL;
}
if (e->next_offset < sizeof(struct compat_arpt_entry) +
sizeof(struct compat_xt_entry_target)) {
duprintf("checking: element %p size %u\n",
e, e->next_offset);
return -EINVAL;
}
/* For purposes of check_entry casting the compat entry is fine */
ret = check_entry((struct arpt_entry *)e, name);
if (ret)
return ret;
off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
entry_offset = (void *)e - (void *)base;
t = compat_arpt_get_target(e);
target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
t->u.user.revision);
if (IS_ERR(target)) {
duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
t->u.user.name);
ret = PTR_ERR(target);
goto out;
}
t->u.kernel.target = target;
off += xt_compat_target_offset(target);
*size += off;
ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
if (ret)
goto release_target;
/* 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];
}
/* Clear counters and comefrom */
memset(&e->counters, 0, sizeof(e->counters));
e->comefrom = 0;
return 0;
release_target:
module_put(t->u.kernel.target->me);
out:
return ret;
}
static int
compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
unsigned int *size, const char *name,
struct xt_table_info *newinfo, unsigned char *base)
{
struct xt_entry_target *t;
struct xt_target *target;
struct arpt_entry *de;
unsigned int origsize;
int ret, h;
ret = 0;
origsize = *size;
de = (struct arpt_entry *)*dstptr;
memcpy(de, e, sizeof(struct arpt_entry));
memcpy(&de->counters, &e->counters, sizeof(e->counters));
*dstptr += sizeof(struct arpt_entry);
*size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
de->target_offset = e->target_offset - (origsize - *size);
t = compat_arpt_get_target(e);
target = t->u.kernel.target;
xt_compat_target_from_user(t, dstptr, size);
de->next_offset = e->next_offset - (origsize - *size);
for (h = 0; h < NF_ARP_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;
}
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, j;
struct xt_table_info *newinfo, *info;
void *pos, *entry0, *entry1;
struct compat_arpt_entry *iter0;
struct arpt_entry *iter1;
unsigned int size;
int ret = 0;
info = *pinfo;
entry0 = *pentry0;
size = total_size;
info->number = number;
/* Init all hooks to impossible value. */
for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
info->hook_entry[i] = 0xFFFFFFFF;
info->underflow[i] = 0xFFFFFFFF;
}
duprintf("translate_compat_table: size %u\n", info->size);
j = 0;
xt_compat_lock(NFPROTO_ARP);
xt_compat_init_offsets(NFPROTO_ARP, number);
/* Walk through entries, checking offsets. */
xt_entry_foreach(iter0, entry0, total_size) {
ret = check_compat_entry_size_and_hooks(iter0, info, &size,
entry0,
entry0 + total_size,
hook_entries,
underflows,
name);
if (ret != 0)
goto out_unlock;
++j;
}
ret = -EINVAL;
if (j != number) {
duprintf("translate_compat_table: %u not %u entries\n",
j, number);
goto out_unlock;
}
/* Check hooks all assigned */
for (i = 0; i < NF_ARP_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_ARP_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;
xt_entry_foreach(iter0, entry0, total_size) {
ret = compat_copy_entry_from_user(iter0, &pos, &size,
name, newinfo, entry1);
if (ret != 0)
break;
}
xt_compat_flush_offsets(NFPROTO_ARP);
xt_compat_unlock(NFPROTO_ARP);
if (ret)
goto free_newinfo;
ret = -ELOOP;
if (!mark_source_chains(newinfo, valid_hooks, entry1))
goto free_newinfo;
i = 0;
xt_entry_foreach(iter1, entry1, newinfo->size) {
ret = check_target(iter1, name);
if (ret != 0)
break;
++i;
if (strcmp(arpt_get_target(iter1)->u.user.name,
XT_ERROR_TARGET) == 0)
++newinfo->stacksize;
}
if (ret) {
/*
* The first i matches need cleanup_entry (calls ->destroy)
* because they had called ->check already. The other j-i
* entries need only release.
*/
int skip = i;
j -= i;
xt_entry_foreach(iter0, entry0, newinfo->size) {
if (skip-- > 0)
continue;
if (j-- == 0)
break;
compat_release_entry(iter0);
}
xt_entry_foreach(iter1, entry1, newinfo->size) {
if (i-- == 0)
break;
cleanup_entry(iter1);
}
xt_free_table_info(newinfo);
return ret;
}
/* 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:
xt_entry_foreach(iter0, entry0, total_size) {
if (j-- == 0)
break;
compat_release_entry(iter0);
}
return ret;
out_unlock:
xt_compat_flush_offsets(NFPROTO_ARP);
xt_compat_unlock(NFPROTO_ARP);
goto out;
}
struct compat_arpt_replace {
char name[XT_TABLE_MAXNAMELEN];
u32 valid_hooks;
u32 num_entries;
u32 size;
u32 hook_entry[NF_ARP_NUMHOOKS];
u32 underflow[NF_ARP_NUMHOOKS];
u32 num_counters;
compat_uptr_t counters;
struct compat_arpt_entry entries[0];
};
static int compat_do_replace(struct net *net, void __user *user,
unsigned int len)
{
int ret;
struct compat_arpt_replace tmp;
struct xt_table_info *newinfo;
void *loc_cpu_entry;
struct arpt_entry *iter;
if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
return -EFAULT;
/* overflow check */
if (tmp.size >= INT_MAX / num_possible_cpus())
return -ENOMEM;
if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
return -ENOMEM;
if (tmp.num_counters == 0)
return -EINVAL;
tmp.name[sizeof(tmp.name)-1] = 0;
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;
}
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(net, tmp.name, tmp.valid_hooks, newinfo,
tmp.num_counters, compat_ptr(tmp.counters));
if (ret)
goto free_newinfo_untrans;
return 0;
free_newinfo_untrans:
xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
cleanup_entry(iter);
free_newinfo:
xt_free_table_info(newinfo);
return ret;
}
static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
unsigned int len)
{
int ret;
if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
return -EPERM;
switch (cmd) {
case ARPT_SO_SET_REPLACE:
ret = compat_do_replace(sock_net(sk), user, len);
break;
case ARPT_SO_SET_ADD_COUNTERS:
ret = do_add_counters(sock_net(sk), user, len, 1);
break;
default:
duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
ret = -EINVAL;
}
return ret;
}
static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
compat_uint_t *size,
struct xt_counters *counters,
unsigned int i)
{
struct xt_entry_target *t;
struct compat_arpt_entry __user *ce;
u_int16_t target_offset, next_offset;
compat_uint_t origsize;
int ret;
origsize = *size;
ce = (struct compat_arpt_entry __user *)*dstptr;
if (copy_to_user(ce, e, sizeof(struct arpt_entry)) != 0 ||
copy_to_user(&ce->counters, &counters[i],
sizeof(counters[i])) != 0)
return -EFAULT;
*dstptr += sizeof(struct compat_arpt_entry);
*size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
target_offset = e->target_offset - (origsize - *size);
t = arpt_get_target(e);
ret = xt_compat_target_to_user(t, dstptr, size);
if (ret)
return ret;
next_offset = e->next_offset - (origsize - *size);
if (put_user(target_offset, &ce->target_offset) != 0 ||
put_user(next_offset, &ce->next_offset) != 0)
return -EFAULT;
return 0;
}
static int compat_copy_entries_to_user(unsigned int total_size,
struct xt_table *table,
void __user *userptr)
{
struct xt_counters *counters;
const struct xt_table_info *private = table->private;
void __user *pos;
unsigned int size;
int ret = 0;
void *loc_cpu_entry;
unsigned int i = 0;
struct arpt_entry *iter;
counters = alloc_counters(table);
if (IS_ERR(counters))
return PTR_ERR(counters);
/* choose the copy on our node/cpu */
loc_cpu_entry = private->entries[raw_smp_processor_id()];
pos = userptr;
size = total_size;
xt_entry_foreach(iter, loc_cpu_entry, total_size) {
ret = compat_copy_entry_to_user(iter, &pos,
&size, counters, i++);
if (ret != 0)
break;
}
vfree(counters);
return ret;
}
struct compat_arpt_get_entries {
char name[XT_TABLE_MAXNAMELEN];
compat_uint_t size;
struct compat_arpt_entry entrytable[0];
};
static int compat_get_entries(struct net *net,
struct compat_arpt_get_entries __user *uptr,
int *len)
{
int ret;
struct compat_arpt_get_entries get;
struct xt_table *t;
if (*len < sizeof(get)) {
duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
return -EINVAL;
}
if (copy_from_user(&get, uptr, sizeof(get)) != 0)
return -EFAULT;
if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
duprintf("compat_get_entries: %u != %zu\n",
*len, sizeof(get) + get.size);
return -EINVAL;
}
xt_compat_lock(NFPROTO_ARP);
t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
if (!IS_ERR_OR_NULL(t)) {
const 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 = -EAGAIN;
}
xt_compat_flush_offsets(NFPROTO_ARP);
module_put(t->me);
xt_table_unlock(t);
} else
ret = t ? PTR_ERR(t) : -ENOENT;
xt_compat_unlock(NFPROTO_ARP);
return ret;
}
static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
int *len)
{
int ret;
if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
return -EPERM;
switch (cmd) {
case ARPT_SO_GET_INFO:
ret = get_info(sock_net(sk), user, len, 1);
break;
case ARPT_SO_GET_ENTRIES:
ret = compat_get_entries(sock_net(sk), user, len);
break;
default:
ret = do_arpt_get_ctl(sk, cmd, user, len);
}
return ret;
}
#endif
static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
{
int ret;
if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
return -EPERM;
switch (cmd) {
case ARPT_SO_SET_REPLACE:
ret = do_replace(sock_net(sk), user, len);
break;
case ARPT_SO_SET_ADD_COUNTERS:
ret = do_add_counters(sock_net(sk), user, len, 0);
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 (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
return -EPERM;
switch (cmd) {
case ARPT_SO_GET_INFO:
ret = get_info(sock_net(sk), user, len, 0);
break;
case ARPT_SO_GET_ENTRIES:
ret = get_entries(sock_net(sk), user, len);
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;
}
rev.name[sizeof(rev.name)-1] = 0;
try_then_request_module(xt_find_revision(NFPROTO_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;
}
struct xt_table *arpt_register_table(struct net *net,
const struct xt_table *table,
const struct arpt_replace *repl)
{
int ret;
struct xt_table_info *newinfo;
struct xt_table_info bootstrap = {0};
void *loc_cpu_entry;
struct xt_table *new_table;
newinfo = xt_alloc_table_info(repl->size);
if (!newinfo) {
ret = -ENOMEM;
goto out;
}
/* 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(newinfo, loc_cpu_entry, repl);
duprintf("arpt_register_table: translate table gives %d\n", ret);
if (ret != 0)
goto out_free;
new_table = xt_register_table(net, table, &bootstrap, newinfo);
if (IS_ERR(new_table)) {
ret = PTR_ERR(new_table);
goto out_free;
}
return new_table;
out_free:
xt_free_table_info(newinfo);
out:
return ERR_PTR(ret);
}
void arpt_unregister_table(struct xt_table *table)
{
struct xt_table_info *private;
void *loc_cpu_entry;
struct module *table_owner = table->me;
struct arpt_entry *iter;
private = xt_unregister_table(table);
/* Decrease module usage counts and free resources */
loc_cpu_entry = private->entries[raw_smp_processor_id()];
xt_entry_foreach(iter, loc_cpu_entry, private->size)
cleanup_entry(iter);
if (private->number > private->initial_entries)
module_put(table_owner);
xt_free_table_info(private);
}
/* The built-in targets: standard (NULL) and error. */
static struct xt_target arpt_builtin_tg[] __read_mostly = {
{
.name = XT_STANDARD_TARGET,
.targetsize = sizeof(int),
.family = NFPROTO_ARP,
#ifdef CONFIG_COMPAT
.compatsize = sizeof(compat_int_t),
.compat_from_user = compat_standard_from_user,
.compat_to_user = compat_standard_to_user,
#endif
},
{
.name = XT_ERROR_TARGET,
.target = arpt_error,
.targetsize = XT_FUNCTION_MAXNAMELEN,
.family = NFPROTO_ARP,
},
};
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,
#ifdef CONFIG_COMPAT
.compat_set = compat_do_arpt_set_ctl,
#endif
.get_optmin = ARPT_BASE_CTL,
.get_optmax = ARPT_SO_GET_MAX+1,
.get = do_arpt_get_ctl,
#ifdef CONFIG_COMPAT
.compat_get = compat_do_arpt_get_ctl,
#endif
.owner = THIS_MODULE,
};
static int __net_init arp_tables_net_init(struct net *net)
{
return xt_proto_init(net, NFPROTO_ARP);
}
static void __net_exit arp_tables_net_exit(struct net *net)
{
xt_proto_fini(net, NFPROTO_ARP);
}
static struct pernet_operations arp_tables_net_ops = {
.init = arp_tables_net_init,
.exit = arp_tables_net_exit,
};
static int __init arp_tables_init(void)
{
int ret;
ret = register_pernet_subsys(&arp_tables_net_ops);
if (ret < 0)
goto err1;
/* No one else will be downing sem now, so we won't sleep */
ret = xt_register_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
if (ret < 0)
goto err2;
/* Register setsockopt */
ret = nf_register_sockopt(&arpt_sockopts);
if (ret < 0)
goto err4;
printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
return 0;
err4:
xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
err2:
unregister_pernet_subsys(&arp_tables_net_ops);
err1:
return ret;
}
static void __exit arp_tables_fini(void)
{
nf_unregister_sockopt(&arpt_sockopts);
xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
unregister_pernet_subsys(&arp_tables_net_ops);
}
EXPORT_SYMBOL(arpt_register_table);
EXPORT_SYMBOL(arpt_unregister_table);
EXPORT_SYMBOL(arpt_do_table);
module_init(arp_tables_init);
module_exit(arp_tables_fini);