// SPDX-License-Identifier: GPL-2.0-or-later
|
/*
|
* ebtables
|
*
|
* Author:
|
* Bart De Schuymer <bdschuym@pandora.be>
|
*
|
* ebtables.c,v 2.0, July, 2002
|
*
|
* This code is strongly inspired by the iptables code which is
|
* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
|
*/
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kmod.h>
|
#include <linux/module.h>
|
#include <linux/vmalloc.h>
|
#include <linux/netfilter/x_tables.h>
|
#include <linux/netfilter_bridge/ebtables.h>
|
#include <linux/spinlock.h>
|
#include <linux/mutex.h>
|
#include <linux/slab.h>
|
#include <linux/uaccess.h>
|
#include <linux/smp.h>
|
#include <linux/cpumask.h>
|
#include <linux/audit.h>
|
#include <net/sock.h>
|
/* needed for logical [in,out]-dev filtering */
|
#include "../br_private.h"
|
|
/* Each cpu has its own set of counters, so there is no need for write_lock in
|
* the softirq
|
* For reading or updating the counters, the user context needs to
|
* get a write_lock
|
*/
|
|
/* The size of each set of counters is altered to get cache alignment */
|
#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
|
#define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter)))
|
#define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \
|
COUNTER_OFFSET(n) * cpu))
|
|
|
|
static DEFINE_MUTEX(ebt_mutex);
|
|
#ifdef CONFIG_COMPAT
|
static void ebt_standard_compat_from_user(void *dst, const void *src)
|
{
|
int v = *(compat_int_t *)src;
|
|
if (v >= 0)
|
v += xt_compat_calc_jump(NFPROTO_BRIDGE, v);
|
memcpy(dst, &v, sizeof(v));
|
}
|
|
static int ebt_standard_compat_to_user(void __user *dst, const void *src)
|
{
|
compat_int_t cv = *(int *)src;
|
|
if (cv >= 0)
|
cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv);
|
return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
|
}
|
#endif
|
|
|
static struct xt_target ebt_standard_target = {
|
.name = "standard",
|
.revision = 0,
|
.family = NFPROTO_BRIDGE,
|
.targetsize = sizeof(int),
|
#ifdef CONFIG_COMPAT
|
.compatsize = sizeof(compat_int_t),
|
.compat_from_user = ebt_standard_compat_from_user,
|
.compat_to_user = ebt_standard_compat_to_user,
|
#endif
|
};
|
|
static inline int
|
ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb,
|
struct xt_action_param *par)
|
{
|
par->target = w->u.watcher;
|
par->targinfo = w->data;
|
w->u.watcher->target(skb, par);
|
/* watchers don't give a verdict */
|
return 0;
|
}
|
|
static inline int
|
ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb,
|
struct xt_action_param *par)
|
{
|
par->match = m->u.match;
|
par->matchinfo = m->data;
|
return !m->u.match->match(skb, par);
|
}
|
|
static inline int
|
ebt_dev_check(const char *entry, const struct net_device *device)
|
{
|
int i = 0;
|
const char *devname;
|
|
if (*entry == '\0')
|
return 0;
|
if (!device)
|
return 1;
|
devname = device->name;
|
/* 1 is the wildcard token */
|
while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i])
|
i++;
|
return devname[i] != entry[i] && entry[i] != 1;
|
}
|
|
/* process standard matches */
|
static inline int
|
ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb,
|
const struct net_device *in, const struct net_device *out)
|
{
|
const struct ethhdr *h = eth_hdr(skb);
|
const struct net_bridge_port *p;
|
__be16 ethproto;
|
|
if (skb_vlan_tag_present(skb))
|
ethproto = htons(ETH_P_8021Q);
|
else
|
ethproto = h->h_proto;
|
|
if (e->bitmask & EBT_802_3) {
|
if (NF_INVF(e, EBT_IPROTO, eth_proto_is_802_3(ethproto)))
|
return 1;
|
} else if (!(e->bitmask & EBT_NOPROTO) &&
|
NF_INVF(e, EBT_IPROTO, e->ethproto != ethproto))
|
return 1;
|
|
if (NF_INVF(e, EBT_IIN, ebt_dev_check(e->in, in)))
|
return 1;
|
if (NF_INVF(e, EBT_IOUT, ebt_dev_check(e->out, out)))
|
return 1;
|
/* rcu_read_lock()ed by nf_hook_thresh */
|
if (in && (p = br_port_get_rcu(in)) != NULL &&
|
NF_INVF(e, EBT_ILOGICALIN,
|
ebt_dev_check(e->logical_in, p->br->dev)))
|
return 1;
|
if (out && (p = br_port_get_rcu(out)) != NULL &&
|
NF_INVF(e, EBT_ILOGICALOUT,
|
ebt_dev_check(e->logical_out, p->br->dev)))
|
return 1;
|
|
if (e->bitmask & EBT_SOURCEMAC) {
|
if (NF_INVF(e, EBT_ISOURCE,
|
!ether_addr_equal_masked(h->h_source, e->sourcemac,
|
e->sourcemsk)))
|
return 1;
|
}
|
if (e->bitmask & EBT_DESTMAC) {
|
if (NF_INVF(e, EBT_IDEST,
|
!ether_addr_equal_masked(h->h_dest, e->destmac,
|
e->destmsk)))
|
return 1;
|
}
|
return 0;
|
}
|
|
static inline
|
struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry)
|
{
|
return (void *)entry + entry->next_offset;
|
}
|
|
static inline const struct ebt_entry_target *
|
ebt_get_target_c(const struct ebt_entry *e)
|
{
|
return ebt_get_target((struct ebt_entry *)e);
|
}
|
|
/* Do some firewalling */
|
unsigned int ebt_do_table(struct sk_buff *skb,
|
const struct nf_hook_state *state,
|
struct ebt_table *table)
|
{
|
unsigned int hook = state->hook;
|
int i, nentries;
|
struct ebt_entry *point;
|
struct ebt_counter *counter_base, *cb_base;
|
const struct ebt_entry_target *t;
|
int verdict, sp = 0;
|
struct ebt_chainstack *cs;
|
struct ebt_entries *chaininfo;
|
const char *base;
|
const struct ebt_table_info *private;
|
struct xt_action_param acpar;
|
|
acpar.state = state;
|
acpar.hotdrop = false;
|
|
read_lock_bh(&table->lock);
|
private = table->private;
|
cb_base = COUNTER_BASE(private->counters, private->nentries,
|
smp_processor_id());
|
if (private->chainstack)
|
cs = private->chainstack[smp_processor_id()];
|
else
|
cs = NULL;
|
chaininfo = private->hook_entry[hook];
|
nentries = private->hook_entry[hook]->nentries;
|
point = (struct ebt_entry *)(private->hook_entry[hook]->data);
|
counter_base = cb_base + private->hook_entry[hook]->counter_offset;
|
/* base for chain jumps */
|
base = private->entries;
|
i = 0;
|
while (i < nentries) {
|
if (ebt_basic_match(point, skb, state->in, state->out))
|
goto letscontinue;
|
|
if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0)
|
goto letscontinue;
|
if (acpar.hotdrop) {
|
read_unlock_bh(&table->lock);
|
return NF_DROP;
|
}
|
|
ADD_COUNTER(*(counter_base + i), skb->len, 1);
|
|
/* these should only watch: not modify, nor tell us
|
* what to do with the packet
|
*/
|
EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar);
|
|
t = ebt_get_target_c(point);
|
/* standard target */
|
if (!t->u.target->target)
|
verdict = ((struct ebt_standard_target *)t)->verdict;
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else {
|
acpar.target = t->u.target;
|
acpar.targinfo = t->data;
|
verdict = t->u.target->target(skb, &acpar);
|
}
|
if (verdict == EBT_ACCEPT) {
|
read_unlock_bh(&table->lock);
|
return NF_ACCEPT;
|
}
|
if (verdict == EBT_DROP) {
|
read_unlock_bh(&table->lock);
|
return NF_DROP;
|
}
|
if (verdict == EBT_RETURN) {
|
letsreturn:
|
if (WARN(sp == 0, "RETURN on base chain")) {
|
/* act like this is EBT_CONTINUE */
|
goto letscontinue;
|
}
|
|
sp--;
|
/* put all the local variables right */
|
i = cs[sp].n;
|
chaininfo = cs[sp].chaininfo;
|
nentries = chaininfo->nentries;
|
point = cs[sp].e;
|
counter_base = cb_base +
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chaininfo->counter_offset;
|
continue;
|
}
|
if (verdict == EBT_CONTINUE)
|
goto letscontinue;
|
|
if (WARN(verdict < 0, "bogus standard verdict\n")) {
|
read_unlock_bh(&table->lock);
|
return NF_DROP;
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}
|
|
/* jump to a udc */
|
cs[sp].n = i + 1;
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cs[sp].chaininfo = chaininfo;
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cs[sp].e = ebt_next_entry(point);
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i = 0;
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chaininfo = (struct ebt_entries *) (base + verdict);
|
|
if (WARN(chaininfo->distinguisher, "jump to non-chain\n")) {
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read_unlock_bh(&table->lock);
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return NF_DROP;
|
}
|
|
nentries = chaininfo->nentries;
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point = (struct ebt_entry *)chaininfo->data;
|
counter_base = cb_base + chaininfo->counter_offset;
|
sp++;
|
continue;
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letscontinue:
|
point = ebt_next_entry(point);
|
i++;
|
}
|
|
/* I actually like this :) */
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if (chaininfo->policy == EBT_RETURN)
|
goto letsreturn;
|
if (chaininfo->policy == EBT_ACCEPT) {
|
read_unlock_bh(&table->lock);
|
return NF_ACCEPT;
|
}
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read_unlock_bh(&table->lock);
|
return NF_DROP;
|
}
|
|
/* If it succeeds, returns element and locks mutex */
|
static inline void *
|
find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
|
struct mutex *mutex)
|
{
|
struct {
|
struct list_head list;
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char name[EBT_FUNCTION_MAXNAMELEN];
|
} *e;
|
|
mutex_lock(mutex);
|
list_for_each_entry(e, head, list) {
|
if (strcmp(e->name, name) == 0)
|
return e;
|
}
|
*error = -ENOENT;
|
mutex_unlock(mutex);
|
return NULL;
|
}
|
|
static void *
|
find_inlist_lock(struct list_head *head, const char *name, const char *prefix,
|
int *error, struct mutex *mutex)
|
{
|
return try_then_request_module(
|
find_inlist_lock_noload(head, name, error, mutex),
|
"%s%s", prefix, name);
|
}
|
|
static inline struct ebt_table *
|
find_table_lock(struct net *net, const char *name, int *error,
|
struct mutex *mutex)
|
{
|
return find_inlist_lock(&net->xt.tables[NFPROTO_BRIDGE], name,
|
"ebtable_", error, mutex);
|
}
|
|
static inline void ebt_free_table_info(struct ebt_table_info *info)
|
{
|
int i;
|
|
if (info->chainstack) {
|
for_each_possible_cpu(i)
|
vfree(info->chainstack[i]);
|
vfree(info->chainstack);
|
}
|
}
|
static inline int
|
ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
|
unsigned int *cnt)
|
{
|
const struct ebt_entry *e = par->entryinfo;
|
struct xt_match *match;
|
size_t left = ((char *)e + e->watchers_offset) - (char *)m;
|
int ret;
|
|
if (left < sizeof(struct ebt_entry_match) ||
|
left - sizeof(struct ebt_entry_match) < m->match_size)
|
return -EINVAL;
|
|
match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision);
|
if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) {
|
if (!IS_ERR(match))
|
module_put(match->me);
|
request_module("ebt_%s", m->u.name);
|
match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision);
|
}
|
if (IS_ERR(match))
|
return PTR_ERR(match);
|
m->u.match = match;
|
|
par->match = match;
|
par->matchinfo = m->data;
|
ret = xt_check_match(par, m->match_size,
|
ntohs(e->ethproto), e->invflags & EBT_IPROTO);
|
if (ret < 0) {
|
module_put(match->me);
|
return ret;
|
}
|
|
(*cnt)++;
|
return 0;
|
}
|
|
static inline int
|
ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par,
|
unsigned int *cnt)
|
{
|
const struct ebt_entry *e = par->entryinfo;
|
struct xt_target *watcher;
|
size_t left = ((char *)e + e->target_offset) - (char *)w;
|
int ret;
|
|
if (left < sizeof(struct ebt_entry_watcher) ||
|
left - sizeof(struct ebt_entry_watcher) < w->watcher_size)
|
return -EINVAL;
|
|
watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0);
|
if (IS_ERR(watcher))
|
return PTR_ERR(watcher);
|
|
if (watcher->family != NFPROTO_BRIDGE) {
|
module_put(watcher->me);
|
return -ENOENT;
|
}
|
|
w->u.watcher = watcher;
|
|
par->target = watcher;
|
par->targinfo = w->data;
|
ret = xt_check_target(par, w->watcher_size,
|
ntohs(e->ethproto), e->invflags & EBT_IPROTO);
|
if (ret < 0) {
|
module_put(watcher->me);
|
return ret;
|
}
|
|
(*cnt)++;
|
return 0;
|
}
|
|
static int ebt_verify_pointers(const struct ebt_replace *repl,
|
struct ebt_table_info *newinfo)
|
{
|
unsigned int limit = repl->entries_size;
|
unsigned int valid_hooks = repl->valid_hooks;
|
unsigned int offset = 0;
|
int i;
|
|
for (i = 0; i < NF_BR_NUMHOOKS; i++)
|
newinfo->hook_entry[i] = NULL;
|
|
newinfo->entries_size = repl->entries_size;
|
newinfo->nentries = repl->nentries;
|
|
while (offset < limit) {
|
size_t left = limit - offset;
|
struct ebt_entry *e = (void *)newinfo->entries + offset;
|
|
if (left < sizeof(unsigned int))
|
break;
|
|
for (i = 0; i < NF_BR_NUMHOOKS; i++) {
|
if ((valid_hooks & (1 << i)) == 0)
|
continue;
|
if ((char __user *)repl->hook_entry[i] ==
|
repl->entries + offset)
|
break;
|
}
|
|
if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) {
|
if (e->bitmask != 0) {
|
/* we make userspace set this right,
|
* so there is no misunderstanding
|
*/
|
return -EINVAL;
|
}
|
if (i != NF_BR_NUMHOOKS)
|
newinfo->hook_entry[i] = (struct ebt_entries *)e;
|
if (left < sizeof(struct ebt_entries))
|
break;
|
offset += sizeof(struct ebt_entries);
|
} else {
|
if (left < sizeof(struct ebt_entry))
|
break;
|
if (left < e->next_offset)
|
break;
|
if (e->next_offset < sizeof(struct ebt_entry))
|
return -EINVAL;
|
offset += e->next_offset;
|
}
|
}
|
if (offset != limit)
|
return -EINVAL;
|
|
/* check if all valid hooks have a chain */
|
for (i = 0; i < NF_BR_NUMHOOKS; i++) {
|
if (!newinfo->hook_entry[i] &&
|
(valid_hooks & (1 << i)))
|
return -EINVAL;
|
}
|
return 0;
|
}
|
|
/* this one is very careful, as it is the first function
|
* to parse the userspace data
|
*/
|
static inline int
|
ebt_check_entry_size_and_hooks(const struct ebt_entry *e,
|
const struct ebt_table_info *newinfo,
|
unsigned int *n, unsigned int *cnt,
|
unsigned int *totalcnt, unsigned int *udc_cnt)
|
{
|
int i;
|
|
for (i = 0; i < NF_BR_NUMHOOKS; i++) {
|
if ((void *)e == (void *)newinfo->hook_entry[i])
|
break;
|
}
|
/* beginning of a new chain
|
* if i == NF_BR_NUMHOOKS it must be a user defined chain
|
*/
|
if (i != NF_BR_NUMHOOKS || !e->bitmask) {
|
/* this checks if the previous chain has as many entries
|
* as it said it has
|
*/
|
if (*n != *cnt)
|
return -EINVAL;
|
|
if (((struct ebt_entries *)e)->policy != EBT_DROP &&
|
((struct ebt_entries *)e)->policy != EBT_ACCEPT) {
|
/* only RETURN from udc */
|
if (i != NF_BR_NUMHOOKS ||
|
((struct ebt_entries *)e)->policy != EBT_RETURN)
|
return -EINVAL;
|
}
|
if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */
|
(*udc_cnt)++;
|
if (((struct ebt_entries *)e)->counter_offset != *totalcnt)
|
return -EINVAL;
|
*n = ((struct ebt_entries *)e)->nentries;
|
*cnt = 0;
|
return 0;
|
}
|
/* a plain old entry, heh */
|
if (sizeof(struct ebt_entry) > e->watchers_offset ||
|
e->watchers_offset > e->target_offset ||
|
e->target_offset >= e->next_offset)
|
return -EINVAL;
|
|
/* this is not checked anywhere else */
|
if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target))
|
return -EINVAL;
|
|
(*cnt)++;
|
(*totalcnt)++;
|
return 0;
|
}
|
|
struct ebt_cl_stack {
|
struct ebt_chainstack cs;
|
int from;
|
unsigned int hookmask;
|
};
|
|
/* We need these positions to check that the jumps to a different part of the
|
* entries is a jump to the beginning of a new chain.
|
*/
|
static inline int
|
ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo,
|
unsigned int *n, struct ebt_cl_stack *udc)
|
{
|
int i;
|
|
/* we're only interested in chain starts */
|
if (e->bitmask)
|
return 0;
|
for (i = 0; i < NF_BR_NUMHOOKS; i++) {
|
if (newinfo->hook_entry[i] == (struct ebt_entries *)e)
|
break;
|
}
|
/* only care about udc */
|
if (i != NF_BR_NUMHOOKS)
|
return 0;
|
|
udc[*n].cs.chaininfo = (struct ebt_entries *)e;
|
/* these initialisations are depended on later in check_chainloops() */
|
udc[*n].cs.n = 0;
|
udc[*n].hookmask = 0;
|
|
(*n)++;
|
return 0;
|
}
|
|
static inline int
|
ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i)
|
{
|
struct xt_mtdtor_param par;
|
|
if (i && (*i)-- == 0)
|
return 1;
|
|
par.net = net;
|
par.match = m->u.match;
|
par.matchinfo = m->data;
|
par.family = NFPROTO_BRIDGE;
|
if (par.match->destroy != NULL)
|
par.match->destroy(&par);
|
module_put(par.match->me);
|
return 0;
|
}
|
|
static inline int
|
ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i)
|
{
|
struct xt_tgdtor_param par;
|
|
if (i && (*i)-- == 0)
|
return 1;
|
|
par.net = net;
|
par.target = w->u.watcher;
|
par.targinfo = w->data;
|
par.family = NFPROTO_BRIDGE;
|
if (par.target->destroy != NULL)
|
par.target->destroy(&par);
|
module_put(par.target->me);
|
return 0;
|
}
|
|
static inline int
|
ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt)
|
{
|
struct xt_tgdtor_param par;
|
struct ebt_entry_target *t;
|
|
if (e->bitmask == 0)
|
return 0;
|
/* we're done */
|
if (cnt && (*cnt)-- == 0)
|
return 1;
|
EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL);
|
EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL);
|
t = ebt_get_target(e);
|
|
par.net = net;
|
par.target = t->u.target;
|
par.targinfo = t->data;
|
par.family = NFPROTO_BRIDGE;
|
if (par.target->destroy != NULL)
|
par.target->destroy(&par);
|
module_put(par.target->me);
|
return 0;
|
}
|
|
static inline int
|
ebt_check_entry(struct ebt_entry *e, struct net *net,
|
const struct ebt_table_info *newinfo,
|
const char *name, unsigned int *cnt,
|
struct ebt_cl_stack *cl_s, unsigned int udc_cnt)
|
{
|
struct ebt_entry_target *t;
|
struct xt_target *target;
|
unsigned int i, j, hook = 0, hookmask = 0;
|
size_t gap;
|
int ret;
|
struct xt_mtchk_param mtpar;
|
struct xt_tgchk_param tgpar;
|
|
/* don't mess with the struct ebt_entries */
|
if (e->bitmask == 0)
|
return 0;
|
|
if (e->bitmask & ~EBT_F_MASK)
|
return -EINVAL;
|
|
if (e->invflags & ~EBT_INV_MASK)
|
return -EINVAL;
|
|
if ((e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3))
|
return -EINVAL;
|
|
/* what hook do we belong to? */
|
for (i = 0; i < NF_BR_NUMHOOKS; i++) {
|
if (!newinfo->hook_entry[i])
|
continue;
|
if ((char *)newinfo->hook_entry[i] < (char *)e)
|
hook = i;
|
else
|
break;
|
}
|
/* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on
|
* a base chain
|
*/
|
if (i < NF_BR_NUMHOOKS)
|
hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
|
else {
|
for (i = 0; i < udc_cnt; i++)
|
if ((char *)(cl_s[i].cs.chaininfo) > (char *)e)
|
break;
|
if (i == 0)
|
hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS);
|
else
|
hookmask = cl_s[i - 1].hookmask;
|
}
|
i = 0;
|
|
memset(&mtpar, 0, sizeof(mtpar));
|
memset(&tgpar, 0, sizeof(tgpar));
|
mtpar.net = tgpar.net = net;
|
mtpar.table = tgpar.table = name;
|
mtpar.entryinfo = tgpar.entryinfo = e;
|
mtpar.hook_mask = tgpar.hook_mask = hookmask;
|
mtpar.family = tgpar.family = NFPROTO_BRIDGE;
|
ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i);
|
if (ret != 0)
|
goto cleanup_matches;
|
j = 0;
|
ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j);
|
if (ret != 0)
|
goto cleanup_watchers;
|
t = ebt_get_target(e);
|
gap = e->next_offset - e->target_offset;
|
|
target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0);
|
if (IS_ERR(target)) {
|
ret = PTR_ERR(target);
|
goto cleanup_watchers;
|
}
|
|
/* Reject UNSPEC, xtables verdicts/return values are incompatible */
|
if (target->family != NFPROTO_BRIDGE) {
|
module_put(target->me);
|
ret = -ENOENT;
|
goto cleanup_watchers;
|
}
|
|
t->u.target = target;
|
if (t->u.target == &ebt_standard_target) {
|
if (gap < sizeof(struct ebt_standard_target)) {
|
ret = -EFAULT;
|
goto cleanup_watchers;
|
}
|
if (((struct ebt_standard_target *)t)->verdict <
|
-NUM_STANDARD_TARGETS) {
|
ret = -EFAULT;
|
goto cleanup_watchers;
|
}
|
} else if (t->target_size > gap - sizeof(struct ebt_entry_target)) {
|
module_put(t->u.target->me);
|
ret = -EFAULT;
|
goto cleanup_watchers;
|
}
|
|
tgpar.target = target;
|
tgpar.targinfo = t->data;
|
ret = xt_check_target(&tgpar, t->target_size,
|
ntohs(e->ethproto), e->invflags & EBT_IPROTO);
|
if (ret < 0) {
|
module_put(target->me);
|
goto cleanup_watchers;
|
}
|
(*cnt)++;
|
return 0;
|
cleanup_watchers:
|
EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j);
|
cleanup_matches:
|
EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i);
|
return ret;
|
}
|
|
/* checks for loops and sets the hook mask for udc
|
* the hook mask for udc tells us from which base chains the udc can be
|
* accessed. This mask is a parameter to the check() functions of the extensions
|
*/
|
static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s,
|
unsigned int udc_cnt, unsigned int hooknr, char *base)
|
{
|
int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict;
|
const struct ebt_entry *e = (struct ebt_entry *)chain->data;
|
const struct ebt_entry_target *t;
|
|
while (pos < nentries || chain_nr != -1) {
|
/* end of udc, go back one 'recursion' step */
|
if (pos == nentries) {
|
/* put back values of the time when this chain was called */
|
e = cl_s[chain_nr].cs.e;
|
if (cl_s[chain_nr].from != -1)
|
nentries =
|
cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries;
|
else
|
nentries = chain->nentries;
|
pos = cl_s[chain_nr].cs.n;
|
/* make sure we won't see a loop that isn't one */
|
cl_s[chain_nr].cs.n = 0;
|
chain_nr = cl_s[chain_nr].from;
|
if (pos == nentries)
|
continue;
|
}
|
t = ebt_get_target_c(e);
|
if (strcmp(t->u.name, EBT_STANDARD_TARGET))
|
goto letscontinue;
|
if (e->target_offset + sizeof(struct ebt_standard_target) >
|
e->next_offset)
|
return -1;
|
|
verdict = ((struct ebt_standard_target *)t)->verdict;
|
if (verdict >= 0) { /* jump to another chain */
|
struct ebt_entries *hlp2 =
|
(struct ebt_entries *)(base + verdict);
|
for (i = 0; i < udc_cnt; i++)
|
if (hlp2 == cl_s[i].cs.chaininfo)
|
break;
|
/* bad destination or loop */
|
if (i == udc_cnt)
|
return -1;
|
|
if (cl_s[i].cs.n)
|
return -1;
|
|
if (cl_s[i].hookmask & (1 << hooknr))
|
goto letscontinue;
|
/* this can't be 0, so the loop test is correct */
|
cl_s[i].cs.n = pos + 1;
|
pos = 0;
|
cl_s[i].cs.e = ebt_next_entry(e);
|
e = (struct ebt_entry *)(hlp2->data);
|
nentries = hlp2->nentries;
|
cl_s[i].from = chain_nr;
|
chain_nr = i;
|
/* this udc is accessible from the base chain for hooknr */
|
cl_s[i].hookmask |= (1 << hooknr);
|
continue;
|
}
|
letscontinue:
|
e = ebt_next_entry(e);
|
pos++;
|
}
|
return 0;
|
}
|
|
/* do the parsing of the table/chains/entries/matches/watchers/targets, heh */
|
static int translate_table(struct net *net, const char *name,
|
struct ebt_table_info *newinfo)
|
{
|
unsigned int i, j, k, udc_cnt;
|
int ret;
|
struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */
|
|
i = 0;
|
while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i])
|
i++;
|
if (i == NF_BR_NUMHOOKS)
|
return -EINVAL;
|
|
if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries)
|
return -EINVAL;
|
|
/* make sure chains are ordered after each other in same order
|
* as their corresponding hooks
|
*/
|
for (j = i + 1; j < NF_BR_NUMHOOKS; j++) {
|
if (!newinfo->hook_entry[j])
|
continue;
|
if (newinfo->hook_entry[j] <= newinfo->hook_entry[i])
|
return -EINVAL;
|
|
i = j;
|
}
|
|
/* do some early checkings and initialize some things */
|
i = 0; /* holds the expected nr. of entries for the chain */
|
j = 0; /* holds the up to now counted entries for the chain */
|
k = 0; /* holds the total nr. of entries, should equal
|
* newinfo->nentries afterwards
|
*/
|
udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */
|
ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
|
ebt_check_entry_size_and_hooks, newinfo,
|
&i, &j, &k, &udc_cnt);
|
|
if (ret != 0)
|
return ret;
|
|
if (i != j)
|
return -EINVAL;
|
|
if (k != newinfo->nentries)
|
return -EINVAL;
|
|
/* get the location of the udc, put them in an array
|
* while we're at it, allocate the chainstack
|
*/
|
if (udc_cnt) {
|
/* this will get free'd in do_replace()/ebt_register_table()
|
* if an error occurs
|
*/
|
newinfo->chainstack =
|
vmalloc(array_size(nr_cpu_ids,
|
sizeof(*(newinfo->chainstack))));
|
if (!newinfo->chainstack)
|
return -ENOMEM;
|
for_each_possible_cpu(i) {
|
newinfo->chainstack[i] =
|
vmalloc(array_size(udc_cnt, sizeof(*(newinfo->chainstack[0]))));
|
if (!newinfo->chainstack[i]) {
|
while (i)
|
vfree(newinfo->chainstack[--i]);
|
vfree(newinfo->chainstack);
|
newinfo->chainstack = NULL;
|
return -ENOMEM;
|
}
|
}
|
|
cl_s = vmalloc(array_size(udc_cnt, sizeof(*cl_s)));
|
if (!cl_s)
|
return -ENOMEM;
|
i = 0; /* the i'th udc */
|
EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
|
ebt_get_udc_positions, newinfo, &i, cl_s);
|
/* sanity check */
|
if (i != udc_cnt) {
|
vfree(cl_s);
|
return -EFAULT;
|
}
|
}
|
|
/* Check for loops */
|
for (i = 0; i < NF_BR_NUMHOOKS; i++)
|
if (newinfo->hook_entry[i])
|
if (check_chainloops(newinfo->hook_entry[i],
|
cl_s, udc_cnt, i, newinfo->entries)) {
|
vfree(cl_s);
|
return -EINVAL;
|
}
|
|
/* we now know the following (along with E=mc²):
|
* - the nr of entries in each chain is right
|
* - the size of the allocated space is right
|
* - all valid hooks have a corresponding chain
|
* - there are no loops
|
* - wrong data can still be on the level of a single entry
|
* - could be there are jumps to places that are not the
|
* beginning of a chain. This can only occur in chains that
|
* are not accessible from any base chains, so we don't care.
|
*/
|
|
/* used to know what we need to clean up if something goes wrong */
|
i = 0;
|
ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
|
ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt);
|
if (ret != 0) {
|
EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
|
ebt_cleanup_entry, net, &i);
|
}
|
vfree(cl_s);
|
return ret;
|
}
|
|
/* called under write_lock */
|
static void get_counters(const struct ebt_counter *oldcounters,
|
struct ebt_counter *counters, unsigned int nentries)
|
{
|
int i, cpu;
|
struct ebt_counter *counter_base;
|
|
/* counters of cpu 0 */
|
memcpy(counters, oldcounters,
|
sizeof(struct ebt_counter) * nentries);
|
|
/* add other counters to those of cpu 0 */
|
for_each_possible_cpu(cpu) {
|
if (cpu == 0)
|
continue;
|
counter_base = COUNTER_BASE(oldcounters, nentries, cpu);
|
for (i = 0; i < nentries; i++)
|
ADD_COUNTER(counters[i], counter_base[i].bcnt,
|
counter_base[i].pcnt);
|
}
|
}
|
|
static int do_replace_finish(struct net *net, struct ebt_replace *repl,
|
struct ebt_table_info *newinfo)
|
{
|
int ret;
|
struct ebt_counter *counterstmp = NULL;
|
/* used to be able to unlock earlier */
|
struct ebt_table_info *table;
|
struct ebt_table *t;
|
|
/* the user wants counters back
|
* the check on the size is done later, when we have the lock
|
*/
|
if (repl->num_counters) {
|
unsigned long size = repl->num_counters * sizeof(*counterstmp);
|
counterstmp = vmalloc(size);
|
if (!counterstmp)
|
return -ENOMEM;
|
}
|
|
newinfo->chainstack = NULL;
|
ret = ebt_verify_pointers(repl, newinfo);
|
if (ret != 0)
|
goto free_counterstmp;
|
|
ret = translate_table(net, repl->name, newinfo);
|
|
if (ret != 0)
|
goto free_counterstmp;
|
|
t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
|
if (!t) {
|
ret = -ENOENT;
|
goto free_iterate;
|
}
|
|
if (repl->valid_hooks != t->valid_hooks) {
|
ret = -EINVAL;
|
goto free_unlock;
|
}
|
|
if (repl->num_counters && repl->num_counters != t->private->nentries) {
|
ret = -EINVAL;
|
goto free_unlock;
|
}
|
|
/* we have the mutex lock, so no danger in reading this pointer */
|
table = t->private;
|
/* make sure the table can only be rmmod'ed if it contains no rules */
|
if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) {
|
ret = -ENOENT;
|
goto free_unlock;
|
} else if (table->nentries && !newinfo->nentries)
|
module_put(t->me);
|
/* we need an atomic snapshot of the counters */
|
write_lock_bh(&t->lock);
|
if (repl->num_counters)
|
get_counters(t->private->counters, counterstmp,
|
t->private->nentries);
|
|
t->private = newinfo;
|
write_unlock_bh(&t->lock);
|
mutex_unlock(&ebt_mutex);
|
/* so, a user can change the chains while having messed up her counter
|
* allocation. Only reason why this is done is because this way the lock
|
* is held only once, while this doesn't bring the kernel into a
|
* dangerous state.
|
*/
|
if (repl->num_counters &&
|
copy_to_user(repl->counters, counterstmp,
|
repl->num_counters * sizeof(struct ebt_counter))) {
|
/* Silent error, can't fail, new table is already in place */
|
net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n");
|
}
|
|
/* decrease module count and free resources */
|
EBT_ENTRY_ITERATE(table->entries, table->entries_size,
|
ebt_cleanup_entry, net, NULL);
|
|
vfree(table->entries);
|
ebt_free_table_info(table);
|
vfree(table);
|
vfree(counterstmp);
|
|
audit_log_nfcfg(repl->name, AF_BRIDGE, repl->nentries,
|
AUDIT_XT_OP_REPLACE, GFP_KERNEL);
|
return ret;
|
|
free_unlock:
|
mutex_unlock(&ebt_mutex);
|
free_iterate:
|
EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size,
|
ebt_cleanup_entry, net, NULL);
|
free_counterstmp:
|
vfree(counterstmp);
|
/* can be initialized in translate_table() */
|
ebt_free_table_info(newinfo);
|
return ret;
|
}
|
|
/* replace the table */
|
static int do_replace(struct net *net, sockptr_t arg, unsigned int len)
|
{
|
int ret, countersize;
|
struct ebt_table_info *newinfo;
|
struct ebt_replace tmp;
|
|
if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0)
|
return -EFAULT;
|
|
if (len != sizeof(tmp) + tmp.entries_size)
|
return -EINVAL;
|
|
if (tmp.entries_size == 0)
|
return -EINVAL;
|
|
/* overflow check */
|
if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
|
NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
|
return -ENOMEM;
|
if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
|
return -ENOMEM;
|
|
tmp.name[sizeof(tmp.name) - 1] = 0;
|
|
countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
|
newinfo = __vmalloc(sizeof(*newinfo) + countersize, GFP_KERNEL_ACCOUNT);
|
if (!newinfo)
|
return -ENOMEM;
|
|
if (countersize)
|
memset(newinfo->counters, 0, countersize);
|
|
newinfo->entries = __vmalloc(tmp.entries_size, GFP_KERNEL_ACCOUNT);
|
if (!newinfo->entries) {
|
ret = -ENOMEM;
|
goto free_newinfo;
|
}
|
if (copy_from_user(
|
newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
|
ret = -EFAULT;
|
goto free_entries;
|
}
|
|
ret = do_replace_finish(net, &tmp, newinfo);
|
if (ret == 0)
|
return ret;
|
free_entries:
|
vfree(newinfo->entries);
|
free_newinfo:
|
vfree(newinfo);
|
return ret;
|
}
|
|
static void __ebt_unregister_table(struct net *net, struct ebt_table *table)
|
{
|
mutex_lock(&ebt_mutex);
|
list_del(&table->list);
|
mutex_unlock(&ebt_mutex);
|
audit_log_nfcfg(table->name, AF_BRIDGE, table->private->nentries,
|
AUDIT_XT_OP_UNREGISTER, GFP_KERNEL);
|
EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size,
|
ebt_cleanup_entry, net, NULL);
|
if (table->private->nentries)
|
module_put(table->me);
|
vfree(table->private->entries);
|
ebt_free_table_info(table->private);
|
vfree(table->private);
|
kfree(table);
|
}
|
|
int ebt_register_table(struct net *net, const struct ebt_table *input_table,
|
const struct nf_hook_ops *ops, struct ebt_table **res)
|
{
|
struct ebt_table_info *newinfo;
|
struct ebt_table *t, *table;
|
struct ebt_replace_kernel *repl;
|
int ret, i, countersize;
|
void *p;
|
|
if (input_table == NULL || (repl = input_table->table) == NULL ||
|
repl->entries == NULL || repl->entries_size == 0 ||
|
repl->counters != NULL || input_table->private != NULL)
|
return -EINVAL;
|
|
/* Don't add one table to multiple lists. */
|
table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL);
|
if (!table) {
|
ret = -ENOMEM;
|
goto out;
|
}
|
|
countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
|
newinfo = vmalloc(sizeof(*newinfo) + countersize);
|
ret = -ENOMEM;
|
if (!newinfo)
|
goto free_table;
|
|
p = vmalloc(repl->entries_size);
|
if (!p)
|
goto free_newinfo;
|
|
memcpy(p, repl->entries, repl->entries_size);
|
newinfo->entries = p;
|
|
newinfo->entries_size = repl->entries_size;
|
newinfo->nentries = repl->nentries;
|
|
if (countersize)
|
memset(newinfo->counters, 0, countersize);
|
|
/* fill in newinfo and parse the entries */
|
newinfo->chainstack = NULL;
|
for (i = 0; i < NF_BR_NUMHOOKS; i++) {
|
if ((repl->valid_hooks & (1 << i)) == 0)
|
newinfo->hook_entry[i] = NULL;
|
else
|
newinfo->hook_entry[i] = p +
|
((char *)repl->hook_entry[i] - repl->entries);
|
}
|
ret = translate_table(net, repl->name, newinfo);
|
if (ret != 0)
|
goto free_chainstack;
|
|
table->private = newinfo;
|
rwlock_init(&table->lock);
|
mutex_lock(&ebt_mutex);
|
list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
|
if (strcmp(t->name, table->name) == 0) {
|
ret = -EEXIST;
|
goto free_unlock;
|
}
|
}
|
|
/* Hold a reference count if the chains aren't empty */
|
if (newinfo->nentries && !try_module_get(table->me)) {
|
ret = -ENOENT;
|
goto free_unlock;
|
}
|
list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
|
mutex_unlock(&ebt_mutex);
|
|
WRITE_ONCE(*res, table);
|
ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
|
if (ret) {
|
__ebt_unregister_table(net, table);
|
*res = NULL;
|
}
|
|
audit_log_nfcfg(repl->name, AF_BRIDGE, repl->nentries,
|
AUDIT_XT_OP_REGISTER, GFP_KERNEL);
|
return ret;
|
free_unlock:
|
mutex_unlock(&ebt_mutex);
|
free_chainstack:
|
ebt_free_table_info(newinfo);
|
vfree(newinfo->entries);
|
free_newinfo:
|
vfree(newinfo);
|
free_table:
|
kfree(table);
|
out:
|
return ret;
|
}
|
|
static struct ebt_table *__ebt_find_table(struct net *net, const char *name)
|
{
|
struct ebt_table *t;
|
|
mutex_lock(&ebt_mutex);
|
|
list_for_each_entry(t, &net->xt.tables[NFPROTO_BRIDGE], list) {
|
if (strcmp(t->name, name) == 0) {
|
mutex_unlock(&ebt_mutex);
|
return t;
|
}
|
}
|
|
mutex_unlock(&ebt_mutex);
|
return NULL;
|
}
|
|
void ebt_unregister_table_pre_exit(struct net *net, const char *name, const struct nf_hook_ops *ops)
|
{
|
struct ebt_table *table = __ebt_find_table(net, name);
|
|
if (table)
|
nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
|
}
|
EXPORT_SYMBOL(ebt_unregister_table_pre_exit);
|
|
void ebt_unregister_table(struct net *net, struct ebt_table *table)
|
{
|
__ebt_unregister_table(net, table);
|
}
|
|
/* userspace just supplied us with counters */
|
static int do_update_counters(struct net *net, const char *name,
|
struct ebt_counter __user *counters,
|
unsigned int num_counters, unsigned int len)
|
{
|
int i, ret;
|
struct ebt_counter *tmp;
|
struct ebt_table *t;
|
|
if (num_counters == 0)
|
return -EINVAL;
|
|
tmp = vmalloc(array_size(num_counters, sizeof(*tmp)));
|
if (!tmp)
|
return -ENOMEM;
|
|
t = find_table_lock(net, name, &ret, &ebt_mutex);
|
if (!t)
|
goto free_tmp;
|
|
if (num_counters != t->private->nentries) {
|
ret = -EINVAL;
|
goto unlock_mutex;
|
}
|
|
if (copy_from_user(tmp, counters, num_counters * sizeof(*counters))) {
|
ret = -EFAULT;
|
goto unlock_mutex;
|
}
|
|
/* we want an atomic add of the counters */
|
write_lock_bh(&t->lock);
|
|
/* we add to the counters of the first cpu */
|
for (i = 0; i < num_counters; i++)
|
ADD_COUNTER(t->private->counters[i], tmp[i].bcnt, tmp[i].pcnt);
|
|
write_unlock_bh(&t->lock);
|
ret = 0;
|
unlock_mutex:
|
mutex_unlock(&ebt_mutex);
|
free_tmp:
|
vfree(tmp);
|
return ret;
|
}
|
|
static int update_counters(struct net *net, sockptr_t arg, unsigned int len)
|
{
|
struct ebt_replace hlp;
|
|
if (copy_from_sockptr(&hlp, arg, sizeof(hlp)))
|
return -EFAULT;
|
|
if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
|
return -EINVAL;
|
|
return do_update_counters(net, hlp.name, hlp.counters,
|
hlp.num_counters, len);
|
}
|
|
static inline int ebt_obj_to_user(char __user *um, const char *_name,
|
const char *data, int entrysize,
|
int usersize, int datasize, u8 revision)
|
{
|
char name[EBT_EXTENSION_MAXNAMELEN] = {0};
|
|
/* ebtables expects 31 bytes long names but xt_match names are 29 bytes
|
* long. Copy 29 bytes and fill remaining bytes with zeroes.
|
*/
|
strlcpy(name, _name, sizeof(name));
|
if (copy_to_user(um, name, EBT_EXTENSION_MAXNAMELEN) ||
|
put_user(revision, (u8 __user *)(um + EBT_EXTENSION_MAXNAMELEN)) ||
|
put_user(datasize, (int __user *)(um + EBT_EXTENSION_MAXNAMELEN + 1)) ||
|
xt_data_to_user(um + entrysize, data, usersize, datasize,
|
XT_ALIGN(datasize)))
|
return -EFAULT;
|
|
return 0;
|
}
|
|
static inline int ebt_match_to_user(const struct ebt_entry_match *m,
|
const char *base, char __user *ubase)
|
{
|
return ebt_obj_to_user(ubase + ((char *)m - base),
|
m->u.match->name, m->data, sizeof(*m),
|
m->u.match->usersize, m->match_size,
|
m->u.match->revision);
|
}
|
|
static inline int ebt_watcher_to_user(const struct ebt_entry_watcher *w,
|
const char *base, char __user *ubase)
|
{
|
return ebt_obj_to_user(ubase + ((char *)w - base),
|
w->u.watcher->name, w->data, sizeof(*w),
|
w->u.watcher->usersize, w->watcher_size,
|
w->u.watcher->revision);
|
}
|
|
static inline int ebt_entry_to_user(struct ebt_entry *e, const char *base,
|
char __user *ubase)
|
{
|
int ret;
|
char __user *hlp;
|
const struct ebt_entry_target *t;
|
|
if (e->bitmask == 0) {
|
/* special case !EBT_ENTRY_OR_ENTRIES */
|
if (copy_to_user(ubase + ((char *)e - base), e,
|
sizeof(struct ebt_entries)))
|
return -EFAULT;
|
return 0;
|
}
|
|
if (copy_to_user(ubase + ((char *)e - base), e, sizeof(*e)))
|
return -EFAULT;
|
|
hlp = ubase + (((char *)e + e->target_offset) - base);
|
t = ebt_get_target_c(e);
|
|
ret = EBT_MATCH_ITERATE(e, ebt_match_to_user, base, ubase);
|
if (ret != 0)
|
return ret;
|
ret = EBT_WATCHER_ITERATE(e, ebt_watcher_to_user, base, ubase);
|
if (ret != 0)
|
return ret;
|
ret = ebt_obj_to_user(hlp, t->u.target->name, t->data, sizeof(*t),
|
t->u.target->usersize, t->target_size,
|
t->u.target->revision);
|
if (ret != 0)
|
return ret;
|
|
return 0;
|
}
|
|
static int copy_counters_to_user(struct ebt_table *t,
|
const struct ebt_counter *oldcounters,
|
void __user *user, unsigned int num_counters,
|
unsigned int nentries)
|
{
|
struct ebt_counter *counterstmp;
|
int ret = 0;
|
|
/* userspace might not need the counters */
|
if (num_counters == 0)
|
return 0;
|
|
if (num_counters != nentries)
|
return -EINVAL;
|
|
counterstmp = vmalloc(array_size(nentries, sizeof(*counterstmp)));
|
if (!counterstmp)
|
return -ENOMEM;
|
|
write_lock_bh(&t->lock);
|
get_counters(oldcounters, counterstmp, nentries);
|
write_unlock_bh(&t->lock);
|
|
if (copy_to_user(user, counterstmp,
|
nentries * sizeof(struct ebt_counter)))
|
ret = -EFAULT;
|
vfree(counterstmp);
|
return ret;
|
}
|
|
/* called with ebt_mutex locked */
|
static int copy_everything_to_user(struct ebt_table *t, void __user *user,
|
const int *len, int cmd)
|
{
|
struct ebt_replace tmp;
|
const struct ebt_counter *oldcounters;
|
unsigned int entries_size, nentries;
|
int ret;
|
char *entries;
|
|
if (cmd == EBT_SO_GET_ENTRIES) {
|
entries_size = t->private->entries_size;
|
nentries = t->private->nentries;
|
entries = t->private->entries;
|
oldcounters = t->private->counters;
|
} else {
|
entries_size = t->table->entries_size;
|
nentries = t->table->nentries;
|
entries = t->table->entries;
|
oldcounters = t->table->counters;
|
}
|
|
if (copy_from_user(&tmp, user, sizeof(tmp)))
|
return -EFAULT;
|
|
if (*len != sizeof(struct ebt_replace) + entries_size +
|
(tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0))
|
return -EINVAL;
|
|
if (tmp.nentries != nentries)
|
return -EINVAL;
|
|
if (tmp.entries_size != entries_size)
|
return -EINVAL;
|
|
ret = copy_counters_to_user(t, oldcounters, tmp.counters,
|
tmp.num_counters, nentries);
|
if (ret)
|
return ret;
|
|
/* set the match/watcher/target names right */
|
return EBT_ENTRY_ITERATE(entries, entries_size,
|
ebt_entry_to_user, entries, tmp.entries);
|
}
|
|
#ifdef CONFIG_COMPAT
|
/* 32 bit-userspace compatibility definitions. */
|
struct compat_ebt_replace {
|
char name[EBT_TABLE_MAXNAMELEN];
|
compat_uint_t valid_hooks;
|
compat_uint_t nentries;
|
compat_uint_t entries_size;
|
/* start of the chains */
|
compat_uptr_t hook_entry[NF_BR_NUMHOOKS];
|
/* nr of counters userspace expects back */
|
compat_uint_t num_counters;
|
/* where the kernel will put the old counters. */
|
compat_uptr_t counters;
|
compat_uptr_t entries;
|
};
|
|
/* struct ebt_entry_match, _target and _watcher have same layout */
|
struct compat_ebt_entry_mwt {
|
union {
|
struct {
|
char name[EBT_EXTENSION_MAXNAMELEN];
|
u8 revision;
|
};
|
compat_uptr_t ptr;
|
} u;
|
compat_uint_t match_size;
|
compat_uint_t data[] __aligned(__alignof__(struct compat_ebt_replace));
|
};
|
|
/* account for possible padding between match_size and ->data */
|
static int ebt_compat_entry_padsize(void)
|
{
|
BUILD_BUG_ON(sizeof(struct ebt_entry_match) <
|
sizeof(struct compat_ebt_entry_mwt));
|
return (int) sizeof(struct ebt_entry_match) -
|
sizeof(struct compat_ebt_entry_mwt);
|
}
|
|
static int ebt_compat_match_offset(const struct xt_match *match,
|
unsigned int userlen)
|
{
|
/* ebt_among needs special handling. The kernel .matchsize is
|
* set to -1 at registration time; at runtime an EBT_ALIGN()ed
|
* value is expected.
|
* Example: userspace sends 4500, ebt_among.c wants 4504.
|
*/
|
if (unlikely(match->matchsize == -1))
|
return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen);
|
return xt_compat_match_offset(match);
|
}
|
|
static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr,
|
unsigned int *size)
|
{
|
const struct xt_match *match = m->u.match;
|
struct compat_ebt_entry_mwt __user *cm = *dstptr;
|
int off = ebt_compat_match_offset(match, m->match_size);
|
compat_uint_t msize = m->match_size - off;
|
|
if (WARN_ON(off >= m->match_size))
|
return -EINVAL;
|
|
if (copy_to_user(cm->u.name, match->name, strlen(match->name) + 1) ||
|
put_user(match->revision, &cm->u.revision) ||
|
put_user(msize, &cm->match_size))
|
return -EFAULT;
|
|
if (match->compat_to_user) {
|
if (match->compat_to_user(cm->data, m->data))
|
return -EFAULT;
|
} else {
|
if (xt_data_to_user(cm->data, m->data, match->usersize, msize,
|
COMPAT_XT_ALIGN(msize)))
|
return -EFAULT;
|
}
|
|
*size -= ebt_compat_entry_padsize() + off;
|
*dstptr = cm->data;
|
*dstptr += msize;
|
return 0;
|
}
|
|
static int compat_target_to_user(struct ebt_entry_target *t,
|
void __user **dstptr,
|
unsigned int *size)
|
{
|
const struct xt_target *target = t->u.target;
|
struct compat_ebt_entry_mwt __user *cm = *dstptr;
|
int off = xt_compat_target_offset(target);
|
compat_uint_t tsize = t->target_size - off;
|
|
if (WARN_ON(off >= t->target_size))
|
return -EINVAL;
|
|
if (copy_to_user(cm->u.name, target->name, strlen(target->name) + 1) ||
|
put_user(target->revision, &cm->u.revision) ||
|
put_user(tsize, &cm->match_size))
|
return -EFAULT;
|
|
if (target->compat_to_user) {
|
if (target->compat_to_user(cm->data, t->data))
|
return -EFAULT;
|
} else {
|
if (xt_data_to_user(cm->data, t->data, target->usersize, tsize,
|
COMPAT_XT_ALIGN(tsize)))
|
return -EFAULT;
|
}
|
|
*size -= ebt_compat_entry_padsize() + off;
|
*dstptr = cm->data;
|
*dstptr += tsize;
|
return 0;
|
}
|
|
static int compat_watcher_to_user(struct ebt_entry_watcher *w,
|
void __user **dstptr,
|
unsigned int *size)
|
{
|
return compat_target_to_user((struct ebt_entry_target *)w,
|
dstptr, size);
|
}
|
|
static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr,
|
unsigned int *size)
|
{
|
struct ebt_entry_target *t;
|
struct ebt_entry __user *ce;
|
u32 watchers_offset, target_offset, next_offset;
|
compat_uint_t origsize;
|
int ret;
|
|
if (e->bitmask == 0) {
|
if (*size < sizeof(struct ebt_entries))
|
return -EINVAL;
|
if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries)))
|
return -EFAULT;
|
|
*dstptr += sizeof(struct ebt_entries);
|
*size -= sizeof(struct ebt_entries);
|
return 0;
|
}
|
|
if (*size < sizeof(*ce))
|
return -EINVAL;
|
|
ce = *dstptr;
|
if (copy_to_user(ce, e, sizeof(*ce)))
|
return -EFAULT;
|
|
origsize = *size;
|
*dstptr += sizeof(*ce);
|
|
ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size);
|
if (ret)
|
return ret;
|
watchers_offset = e->watchers_offset - (origsize - *size);
|
|
ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size);
|
if (ret)
|
return ret;
|
target_offset = e->target_offset - (origsize - *size);
|
|
t = ebt_get_target(e);
|
|
ret = compat_target_to_user(t, dstptr, size);
|
if (ret)
|
return ret;
|
next_offset = e->next_offset - (origsize - *size);
|
|
if (put_user(watchers_offset, &ce->watchers_offset) ||
|
put_user(target_offset, &ce->target_offset) ||
|
put_user(next_offset, &ce->next_offset))
|
return -EFAULT;
|
|
*size -= sizeof(*ce);
|
return 0;
|
}
|
|
static int compat_calc_match(struct ebt_entry_match *m, int *off)
|
{
|
*off += ebt_compat_match_offset(m->u.match, m->match_size);
|
*off += ebt_compat_entry_padsize();
|
return 0;
|
}
|
|
static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off)
|
{
|
*off += xt_compat_target_offset(w->u.watcher);
|
*off += ebt_compat_entry_padsize();
|
return 0;
|
}
|
|
static int compat_calc_entry(const struct ebt_entry *e,
|
const struct ebt_table_info *info,
|
const void *base,
|
struct compat_ebt_replace *newinfo)
|
{
|
const struct ebt_entry_target *t;
|
unsigned int entry_offset;
|
int off, ret, i;
|
|
if (e->bitmask == 0)
|
return 0;
|
|
off = 0;
|
entry_offset = (void *)e - base;
|
|
EBT_MATCH_ITERATE(e, compat_calc_match, &off);
|
EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off);
|
|
t = ebt_get_target_c(e);
|
|
off += xt_compat_target_offset(t->u.target);
|
off += ebt_compat_entry_padsize();
|
|
newinfo->entries_size -= off;
|
|
ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off);
|
if (ret)
|
return ret;
|
|
for (i = 0; i < NF_BR_NUMHOOKS; i++) {
|
const void *hookptr = info->hook_entry[i];
|
if (info->hook_entry[i] &&
|
(e < (struct ebt_entry *)(base - hookptr))) {
|
newinfo->hook_entry[i] -= off;
|
pr_debug("0x%08X -> 0x%08X\n",
|
newinfo->hook_entry[i] + off,
|
newinfo->hook_entry[i]);
|
}
|
}
|
|
return 0;
|
}
|
|
static int ebt_compat_init_offsets(unsigned int number)
|
{
|
if (number > INT_MAX)
|
return -EINVAL;
|
|
/* also count the base chain policies */
|
number += NF_BR_NUMHOOKS;
|
|
return xt_compat_init_offsets(NFPROTO_BRIDGE, number);
|
}
|
|
static int compat_table_info(const struct ebt_table_info *info,
|
struct compat_ebt_replace *newinfo)
|
{
|
unsigned int size = info->entries_size;
|
const void *entries = info->entries;
|
int ret;
|
|
newinfo->entries_size = size;
|
ret = ebt_compat_init_offsets(info->nentries);
|
if (ret)
|
return ret;
|
|
return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info,
|
entries, newinfo);
|
}
|
|
static int compat_copy_everything_to_user(struct ebt_table *t,
|
void __user *user, int *len, int cmd)
|
{
|
struct compat_ebt_replace repl, tmp;
|
struct ebt_counter *oldcounters;
|
struct ebt_table_info tinfo;
|
int ret;
|
void __user *pos;
|
|
memset(&tinfo, 0, sizeof(tinfo));
|
|
if (cmd == EBT_SO_GET_ENTRIES) {
|
tinfo.entries_size = t->private->entries_size;
|
tinfo.nentries = t->private->nentries;
|
tinfo.entries = t->private->entries;
|
oldcounters = t->private->counters;
|
} else {
|
tinfo.entries_size = t->table->entries_size;
|
tinfo.nentries = t->table->nentries;
|
tinfo.entries = t->table->entries;
|
oldcounters = t->table->counters;
|
}
|
|
if (copy_from_user(&tmp, user, sizeof(tmp)))
|
return -EFAULT;
|
|
if (tmp.nentries != tinfo.nentries ||
|
(tmp.num_counters && tmp.num_counters != tinfo.nentries))
|
return -EINVAL;
|
|
memcpy(&repl, &tmp, sizeof(repl));
|
if (cmd == EBT_SO_GET_ENTRIES)
|
ret = compat_table_info(t->private, &repl);
|
else
|
ret = compat_table_info(&tinfo, &repl);
|
if (ret)
|
return ret;
|
|
if (*len != sizeof(tmp) + repl.entries_size +
|
(tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) {
|
pr_err("wrong size: *len %d, entries_size %u, replsz %d\n",
|
*len, tinfo.entries_size, repl.entries_size);
|
return -EINVAL;
|
}
|
|
/* userspace might not need the counters */
|
ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters),
|
tmp.num_counters, tinfo.nentries);
|
if (ret)
|
return ret;
|
|
pos = compat_ptr(tmp.entries);
|
return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size,
|
compat_copy_entry_to_user, &pos, &tmp.entries_size);
|
}
|
|
struct ebt_entries_buf_state {
|
char *buf_kern_start; /* kernel buffer to copy (translated) data to */
|
u32 buf_kern_len; /* total size of kernel buffer */
|
u32 buf_kern_offset; /* amount of data copied so far */
|
u32 buf_user_offset; /* read position in userspace buffer */
|
};
|
|
static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz)
|
{
|
state->buf_kern_offset += sz;
|
return state->buf_kern_offset >= sz ? 0 : -EINVAL;
|
}
|
|
static int ebt_buf_add(struct ebt_entries_buf_state *state,
|
const void *data, unsigned int sz)
|
{
|
if (state->buf_kern_start == NULL)
|
goto count_only;
|
|
if (WARN_ON(state->buf_kern_offset + sz > state->buf_kern_len))
|
return -EINVAL;
|
|
memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz);
|
|
count_only:
|
state->buf_user_offset += sz;
|
return ebt_buf_count(state, sz);
|
}
|
|
static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz)
|
{
|
char *b = state->buf_kern_start;
|
|
if (WARN_ON(b && state->buf_kern_offset > state->buf_kern_len))
|
return -EINVAL;
|
|
if (b != NULL && sz > 0)
|
memset(b + state->buf_kern_offset, 0, sz);
|
/* do not adjust ->buf_user_offset here, we added kernel-side padding */
|
return ebt_buf_count(state, sz);
|
}
|
|
enum compat_mwt {
|
EBT_COMPAT_MATCH,
|
EBT_COMPAT_WATCHER,
|
EBT_COMPAT_TARGET,
|
};
|
|
static int compat_mtw_from_user(const struct compat_ebt_entry_mwt *mwt,
|
enum compat_mwt compat_mwt,
|
struct ebt_entries_buf_state *state,
|
const unsigned char *base)
|
{
|
char name[EBT_EXTENSION_MAXNAMELEN];
|
struct xt_match *match;
|
struct xt_target *wt;
|
void *dst = NULL;
|
int off, pad = 0;
|
unsigned int size_kern, match_size = mwt->match_size;
|
|
if (strscpy(name, mwt->u.name, sizeof(name)) < 0)
|
return -EINVAL;
|
|
if (state->buf_kern_start)
|
dst = state->buf_kern_start + state->buf_kern_offset;
|
|
switch (compat_mwt) {
|
case EBT_COMPAT_MATCH:
|
match = xt_request_find_match(NFPROTO_BRIDGE, name,
|
mwt->u.revision);
|
if (IS_ERR(match))
|
return PTR_ERR(match);
|
|
off = ebt_compat_match_offset(match, match_size);
|
if (dst) {
|
if (match->compat_from_user)
|
match->compat_from_user(dst, mwt->data);
|
else
|
memcpy(dst, mwt->data, match_size);
|
}
|
|
size_kern = match->matchsize;
|
if (unlikely(size_kern == -1))
|
size_kern = match_size;
|
module_put(match->me);
|
break;
|
case EBT_COMPAT_WATCHER:
|
case EBT_COMPAT_TARGET:
|
wt = xt_request_find_target(NFPROTO_BRIDGE, name,
|
mwt->u.revision);
|
if (IS_ERR(wt))
|
return PTR_ERR(wt);
|
off = xt_compat_target_offset(wt);
|
|
if (dst) {
|
if (wt->compat_from_user)
|
wt->compat_from_user(dst, mwt->data);
|
else
|
memcpy(dst, mwt->data, match_size);
|
}
|
|
size_kern = wt->targetsize;
|
module_put(wt->me);
|
break;
|
|
default:
|
return -EINVAL;
|
}
|
|
state->buf_kern_offset += match_size + off;
|
state->buf_user_offset += match_size;
|
pad = XT_ALIGN(size_kern) - size_kern;
|
|
if (pad > 0 && dst) {
|
if (WARN_ON(state->buf_kern_len <= pad))
|
return -EINVAL;
|
if (WARN_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad))
|
return -EINVAL;
|
memset(dst + size_kern, 0, pad);
|
}
|
return off + match_size;
|
}
|
|
/* return size of all matches, watchers or target, including necessary
|
* alignment and padding.
|
*/
|
static int ebt_size_mwt(const struct compat_ebt_entry_mwt *match32,
|
unsigned int size_left, enum compat_mwt type,
|
struct ebt_entries_buf_state *state, const void *base)
|
{
|
const char *buf = (const char *)match32;
|
int growth = 0;
|
|
if (size_left == 0)
|
return 0;
|
|
do {
|
struct ebt_entry_match *match_kern;
|
int ret;
|
|
if (size_left < sizeof(*match32))
|
return -EINVAL;
|
|
match_kern = (struct ebt_entry_match *) state->buf_kern_start;
|
if (match_kern) {
|
char *tmp;
|
tmp = state->buf_kern_start + state->buf_kern_offset;
|
match_kern = (struct ebt_entry_match *) tmp;
|
}
|
ret = ebt_buf_add(state, buf, sizeof(*match32));
|
if (ret < 0)
|
return ret;
|
size_left -= sizeof(*match32);
|
|
/* add padding before match->data (if any) */
|
ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize());
|
if (ret < 0)
|
return ret;
|
|
if (match32->match_size > size_left)
|
return -EINVAL;
|
|
size_left -= match32->match_size;
|
|
ret = compat_mtw_from_user(match32, type, state, base);
|
if (ret < 0)
|
return ret;
|
|
if (WARN_ON(ret < match32->match_size))
|
return -EINVAL;
|
growth += ret - match32->match_size;
|
growth += ebt_compat_entry_padsize();
|
|
buf += sizeof(*match32);
|
buf += match32->match_size;
|
|
if (match_kern)
|
match_kern->match_size = ret;
|
|
match32 = (struct compat_ebt_entry_mwt *) buf;
|
} while (size_left);
|
|
return growth;
|
}
|
|
/* called for all ebt_entry structures. */
|
static int size_entry_mwt(const struct ebt_entry *entry, const unsigned char *base,
|
unsigned int *total,
|
struct ebt_entries_buf_state *state)
|
{
|
unsigned int i, j, startoff, next_expected_off, new_offset = 0;
|
/* stores match/watchers/targets & offset of next struct ebt_entry: */
|
unsigned int offsets[4];
|
unsigned int *offsets_update = NULL;
|
int ret;
|
char *buf_start;
|
|
if (*total < sizeof(struct ebt_entries))
|
return -EINVAL;
|
|
if (!entry->bitmask) {
|
*total -= sizeof(struct ebt_entries);
|
return ebt_buf_add(state, entry, sizeof(struct ebt_entries));
|
}
|
if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry))
|
return -EINVAL;
|
|
startoff = state->buf_user_offset;
|
/* pull in most part of ebt_entry, it does not need to be changed. */
|
ret = ebt_buf_add(state, entry,
|
offsetof(struct ebt_entry, watchers_offset));
|
if (ret < 0)
|
return ret;
|
|
offsets[0] = sizeof(struct ebt_entry); /* matches come first */
|
memcpy(&offsets[1], &entry->watchers_offset,
|
sizeof(offsets) - sizeof(offsets[0]));
|
|
if (state->buf_kern_start) {
|
buf_start = state->buf_kern_start + state->buf_kern_offset;
|
offsets_update = (unsigned int *) buf_start;
|
}
|
ret = ebt_buf_add(state, &offsets[1],
|
sizeof(offsets) - sizeof(offsets[0]));
|
if (ret < 0)
|
return ret;
|
buf_start = (char *) entry;
|
/* 0: matches offset, always follows ebt_entry.
|
* 1: watchers offset, from ebt_entry structure
|
* 2: target offset, from ebt_entry structure
|
* 3: next ebt_entry offset, from ebt_entry structure
|
*
|
* offsets are relative to beginning of struct ebt_entry (i.e., 0).
|
*/
|
for (i = 0; i < 4 ; ++i) {
|
if (offsets[i] > *total)
|
return -EINVAL;
|
|
if (i < 3 && offsets[i] == *total)
|
return -EINVAL;
|
|
if (i == 0)
|
continue;
|
if (offsets[i-1] > offsets[i])
|
return -EINVAL;
|
}
|
|
for (i = 0, j = 1 ; j < 4 ; j++, i++) {
|
struct compat_ebt_entry_mwt *match32;
|
unsigned int size;
|
char *buf = buf_start + offsets[i];
|
|
if (offsets[i] > offsets[j])
|
return -EINVAL;
|
|
match32 = (struct compat_ebt_entry_mwt *) buf;
|
size = offsets[j] - offsets[i];
|
ret = ebt_size_mwt(match32, size, i, state, base);
|
if (ret < 0)
|
return ret;
|
new_offset += ret;
|
if (offsets_update && new_offset) {
|
pr_debug("change offset %d to %d\n",
|
offsets_update[i], offsets[j] + new_offset);
|
offsets_update[i] = offsets[j] + new_offset;
|
}
|
}
|
|
if (state->buf_kern_start == NULL) {
|
unsigned int offset = buf_start - (char *) base;
|
|
ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);
|
if (ret < 0)
|
return ret;
|
}
|
|
next_expected_off = state->buf_user_offset - startoff;
|
if (next_expected_off != entry->next_offset)
|
return -EINVAL;
|
|
if (*total < entry->next_offset)
|
return -EINVAL;
|
*total -= entry->next_offset;
|
return 0;
|
}
|
|
/* repl->entries_size is the size of the ebt_entry blob in userspace.
|
* It might need more memory when copied to a 64 bit kernel in case
|
* userspace is 32-bit. So, first task: find out how much memory is needed.
|
*
|
* Called before validation is performed.
|
*/
|
static int compat_copy_entries(unsigned char *data, unsigned int size_user,
|
struct ebt_entries_buf_state *state)
|
{
|
unsigned int size_remaining = size_user;
|
int ret;
|
|
ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data,
|
&size_remaining, state);
|
if (ret < 0)
|
return ret;
|
|
if (size_remaining)
|
return -EINVAL;
|
|
return state->buf_kern_offset;
|
}
|
|
|
static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
|
sockptr_t arg, unsigned int len)
|
{
|
struct compat_ebt_replace tmp;
|
int i;
|
|
if (len < sizeof(tmp))
|
return -EINVAL;
|
|
if (copy_from_sockptr(&tmp, arg, sizeof(tmp)))
|
return -EFAULT;
|
|
if (len != sizeof(tmp) + tmp.entries_size)
|
return -EINVAL;
|
|
if (tmp.entries_size == 0)
|
return -EINVAL;
|
|
if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) /
|
NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter))
|
return -ENOMEM;
|
if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
|
return -ENOMEM;
|
|
memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));
|
|
/* starting with hook_entry, 32 vs. 64 bit structures are different */
|
for (i = 0; i < NF_BR_NUMHOOKS; i++)
|
repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]);
|
|
repl->num_counters = tmp.num_counters;
|
repl->counters = compat_ptr(tmp.counters);
|
repl->entries = compat_ptr(tmp.entries);
|
return 0;
|
}
|
|
static int compat_do_replace(struct net *net, sockptr_t arg, unsigned int len)
|
{
|
int ret, i, countersize, size64;
|
struct ebt_table_info *newinfo;
|
struct ebt_replace tmp;
|
struct ebt_entries_buf_state state;
|
void *entries_tmp;
|
|
ret = compat_copy_ebt_replace_from_user(&tmp, arg, len);
|
if (ret) {
|
/* try real handler in case userland supplied needed padding */
|
if (ret == -EINVAL && do_replace(net, arg, len) == 0)
|
ret = 0;
|
return ret;
|
}
|
|
countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
|
newinfo = vmalloc(sizeof(*newinfo) + countersize);
|
if (!newinfo)
|
return -ENOMEM;
|
|
if (countersize)
|
memset(newinfo->counters, 0, countersize);
|
|
memset(&state, 0, sizeof(state));
|
|
newinfo->entries = vmalloc(tmp.entries_size);
|
if (!newinfo->entries) {
|
ret = -ENOMEM;
|
goto free_newinfo;
|
}
|
if (copy_from_user(
|
newinfo->entries, tmp.entries, tmp.entries_size) != 0) {
|
ret = -EFAULT;
|
goto free_entries;
|
}
|
|
entries_tmp = newinfo->entries;
|
|
xt_compat_lock(NFPROTO_BRIDGE);
|
|
ret = ebt_compat_init_offsets(tmp.nentries);
|
if (ret < 0)
|
goto out_unlock;
|
|
ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
|
if (ret < 0)
|
goto out_unlock;
|
|
pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n",
|
tmp.entries_size, state.buf_kern_offset, state.buf_user_offset,
|
xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size));
|
|
size64 = ret;
|
newinfo->entries = vmalloc(size64);
|
if (!newinfo->entries) {
|
vfree(entries_tmp);
|
ret = -ENOMEM;
|
goto out_unlock;
|
}
|
|
memset(&state, 0, sizeof(state));
|
state.buf_kern_start = newinfo->entries;
|
state.buf_kern_len = size64;
|
|
ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state);
|
if (WARN_ON(ret < 0)) {
|
vfree(entries_tmp);
|
goto out_unlock;
|
}
|
|
vfree(entries_tmp);
|
tmp.entries_size = size64;
|
|
for (i = 0; i < NF_BR_NUMHOOKS; i++) {
|
char __user *usrptr;
|
if (tmp.hook_entry[i]) {
|
unsigned int delta;
|
usrptr = (char __user *) tmp.hook_entry[i];
|
delta = usrptr - tmp.entries;
|
usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta);
|
tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr;
|
}
|
}
|
|
xt_compat_flush_offsets(NFPROTO_BRIDGE);
|
xt_compat_unlock(NFPROTO_BRIDGE);
|
|
ret = do_replace_finish(net, &tmp, newinfo);
|
if (ret == 0)
|
return ret;
|
free_entries:
|
vfree(newinfo->entries);
|
free_newinfo:
|
vfree(newinfo);
|
return ret;
|
out_unlock:
|
xt_compat_flush_offsets(NFPROTO_BRIDGE);
|
xt_compat_unlock(NFPROTO_BRIDGE);
|
goto free_entries;
|
}
|
|
static int compat_update_counters(struct net *net, sockptr_t arg,
|
unsigned int len)
|
{
|
struct compat_ebt_replace hlp;
|
|
if (copy_from_sockptr(&hlp, arg, sizeof(hlp)))
|
return -EFAULT;
|
|
/* try real handler in case userland supplied needed padding */
|
if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter))
|
return update_counters(net, arg, len);
|
|
return do_update_counters(net, hlp.name, compat_ptr(hlp.counters),
|
hlp.num_counters, len);
|
}
|
|
static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
|
void __user *user, int *len)
|
{
|
int ret;
|
struct compat_ebt_replace tmp;
|
struct ebt_table *t;
|
struct net *net = sock_net(sk);
|
|
if ((cmd == EBT_SO_GET_INFO || cmd == EBT_SO_GET_INIT_INFO) &&
|
*len != sizeof(struct compat_ebt_replace))
|
return -EINVAL;
|
|
if (copy_from_user(&tmp, user, sizeof(tmp)))
|
return -EFAULT;
|
|
tmp.name[sizeof(tmp.name) - 1] = '\0';
|
|
t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
|
if (!t)
|
return ret;
|
|
xt_compat_lock(NFPROTO_BRIDGE);
|
switch (cmd) {
|
case EBT_SO_GET_INFO:
|
tmp.nentries = t->private->nentries;
|
ret = compat_table_info(t->private, &tmp);
|
if (ret)
|
goto out;
|
tmp.valid_hooks = t->valid_hooks;
|
|
if (copy_to_user(user, &tmp, *len) != 0) {
|
ret = -EFAULT;
|
break;
|
}
|
ret = 0;
|
break;
|
case EBT_SO_GET_INIT_INFO:
|
tmp.nentries = t->table->nentries;
|
tmp.entries_size = t->table->entries_size;
|
tmp.valid_hooks = t->table->valid_hooks;
|
|
if (copy_to_user(user, &tmp, *len) != 0) {
|
ret = -EFAULT;
|
break;
|
}
|
ret = 0;
|
break;
|
case EBT_SO_GET_ENTRIES:
|
case EBT_SO_GET_INIT_ENTRIES:
|
/* try real handler first in case of userland-side padding.
|
* in case we are dealing with an 'ordinary' 32 bit binary
|
* without 64bit compatibility padding, this will fail right
|
* after copy_from_user when the *len argument is validated.
|
*
|
* the compat_ variant needs to do one pass over the kernel
|
* data set to adjust for size differences before it the check.
|
*/
|
if (copy_everything_to_user(t, user, len, cmd) == 0)
|
ret = 0;
|
else
|
ret = compat_copy_everything_to_user(t, user, len, cmd);
|
break;
|
default:
|
ret = -EINVAL;
|
}
|
out:
|
xt_compat_flush_offsets(NFPROTO_BRIDGE);
|
xt_compat_unlock(NFPROTO_BRIDGE);
|
mutex_unlock(&ebt_mutex);
|
return ret;
|
}
|
#endif
|
|
static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
|
{
|
struct net *net = sock_net(sk);
|
struct ebt_replace tmp;
|
struct ebt_table *t;
|
int ret;
|
|
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
|
return -EPERM;
|
|
#ifdef CONFIG_COMPAT
|
/* try real handler in case userland supplied needed padding */
|
if (in_compat_syscall() &&
|
((cmd != EBT_SO_GET_INFO && cmd != EBT_SO_GET_INIT_INFO) ||
|
*len != sizeof(tmp)))
|
return compat_do_ebt_get_ctl(sk, cmd, user, len);
|
#endif
|
|
if (copy_from_user(&tmp, user, sizeof(tmp)))
|
return -EFAULT;
|
|
tmp.name[sizeof(tmp.name) - 1] = '\0';
|
|
t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
|
if (!t)
|
return ret;
|
|
switch (cmd) {
|
case EBT_SO_GET_INFO:
|
case EBT_SO_GET_INIT_INFO:
|
if (*len != sizeof(struct ebt_replace)) {
|
ret = -EINVAL;
|
mutex_unlock(&ebt_mutex);
|
break;
|
}
|
if (cmd == EBT_SO_GET_INFO) {
|
tmp.nentries = t->private->nentries;
|
tmp.entries_size = t->private->entries_size;
|
tmp.valid_hooks = t->valid_hooks;
|
} else {
|
tmp.nentries = t->table->nentries;
|
tmp.entries_size = t->table->entries_size;
|
tmp.valid_hooks = t->table->valid_hooks;
|
}
|
mutex_unlock(&ebt_mutex);
|
if (copy_to_user(user, &tmp, *len) != 0) {
|
ret = -EFAULT;
|
break;
|
}
|
ret = 0;
|
break;
|
|
case EBT_SO_GET_ENTRIES:
|
case EBT_SO_GET_INIT_ENTRIES:
|
ret = copy_everything_to_user(t, user, len, cmd);
|
mutex_unlock(&ebt_mutex);
|
break;
|
|
default:
|
mutex_unlock(&ebt_mutex);
|
ret = -EINVAL;
|
}
|
|
return ret;
|
}
|
|
static int do_ebt_set_ctl(struct sock *sk, int cmd, sockptr_t arg,
|
unsigned int len)
|
{
|
struct net *net = sock_net(sk);
|
int ret;
|
|
if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
|
return -EPERM;
|
|
switch (cmd) {
|
case EBT_SO_SET_ENTRIES:
|
#ifdef CONFIG_COMPAT
|
if (in_compat_syscall())
|
ret = compat_do_replace(net, arg, len);
|
else
|
#endif
|
ret = do_replace(net, arg, len);
|
break;
|
case EBT_SO_SET_COUNTERS:
|
#ifdef CONFIG_COMPAT
|
if (in_compat_syscall())
|
ret = compat_update_counters(net, arg, len);
|
else
|
#endif
|
ret = update_counters(net, arg, len);
|
break;
|
default:
|
ret = -EINVAL;
|
}
|
return ret;
|
}
|
|
static struct nf_sockopt_ops ebt_sockopts = {
|
.pf = PF_INET,
|
.set_optmin = EBT_BASE_CTL,
|
.set_optmax = EBT_SO_SET_MAX + 1,
|
.set = do_ebt_set_ctl,
|
.get_optmin = EBT_BASE_CTL,
|
.get_optmax = EBT_SO_GET_MAX + 1,
|
.get = do_ebt_get_ctl,
|
.owner = THIS_MODULE,
|
};
|
|
static int __init ebtables_init(void)
|
{
|
int ret;
|
|
ret = xt_register_target(&ebt_standard_target);
|
if (ret < 0)
|
return ret;
|
ret = nf_register_sockopt(&ebt_sockopts);
|
if (ret < 0) {
|
xt_unregister_target(&ebt_standard_target);
|
return ret;
|
}
|
|
return 0;
|
}
|
|
static void __exit ebtables_fini(void)
|
{
|
nf_unregister_sockopt(&ebt_sockopts);
|
xt_unregister_target(&ebt_standard_target);
|
}
|
|
EXPORT_SYMBOL(ebt_register_table);
|
EXPORT_SYMBOL(ebt_unregister_table);
|
EXPORT_SYMBOL(ebt_do_table);
|
module_init(ebtables_init);
|
module_exit(ebtables_fini);
|
MODULE_LICENSE("GPL");
|
