// SPDX-License-Identifier: GPL-2.0-only
|
/*
|
* x_tables core - Backend for {ip,ip6,arp}_tables
|
*
|
* Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
|
* Copyright (C) 2006-2012 Patrick McHardy <kaber@trash.net>
|
*
|
* Based on existing ip_tables code which is
|
* Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling
|
* Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org>
|
*/
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
#include <linux/kernel.h>
|
#include <linux/module.h>
|
#include <linux/socket.h>
|
#include <linux/net.h>
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#include <linux/proc_fs.h>
|
#include <linux/seq_file.h>
|
#include <linux/string.h>
|
#include <linux/vmalloc.h>
|
#include <linux/mutex.h>
|
#include <linux/mm.h>
|
#include <linux/slab.h>
|
#include <linux/audit.h>
|
#include <linux/user_namespace.h>
|
#include <net/net_namespace.h>
|
|
#include <linux/netfilter/x_tables.h>
|
#include <linux/netfilter_arp.h>
|
#include <linux/netfilter_ipv4/ip_tables.h>
|
#include <linux/netfilter_ipv6/ip6_tables.h>
|
#include <linux/netfilter_arp/arp_tables.h>
|
|
MODULE_LICENSE("GPL");
|
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
|
MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module");
|
|
#define XT_PCPU_BLOCK_SIZE 4096
|
#define XT_MAX_TABLE_SIZE (512 * 1024 * 1024)
|
|
struct compat_delta {
|
unsigned int offset; /* offset in kernel */
|
int delta; /* delta in 32bit user land */
|
};
|
|
struct xt_af {
|
struct mutex mutex;
|
struct list_head match;
|
struct list_head target;
|
#ifdef CONFIG_COMPAT
|
struct mutex compat_mutex;
|
struct compat_delta *compat_tab;
|
unsigned int number; /* number of slots in compat_tab[] */
|
unsigned int cur; /* number of used slots in compat_tab[] */
|
#endif
|
};
|
|
static struct xt_af *xt;
|
|
static const char *const xt_prefix[NFPROTO_NUMPROTO] = {
|
[NFPROTO_UNSPEC] = "x",
|
[NFPROTO_IPV4] = "ip",
|
[NFPROTO_ARP] = "arp",
|
[NFPROTO_BRIDGE] = "eb",
|
[NFPROTO_IPV6] = "ip6",
|
};
|
|
/* Registration hooks for targets. */
|
int xt_register_target(struct xt_target *target)
|
{
|
u_int8_t af = target->family;
|
|
mutex_lock(&xt[af].mutex);
|
list_add(&target->list, &xt[af].target);
|
mutex_unlock(&xt[af].mutex);
|
return 0;
|
}
|
EXPORT_SYMBOL(xt_register_target);
|
|
void
|
xt_unregister_target(struct xt_target *target)
|
{
|
u_int8_t af = target->family;
|
|
mutex_lock(&xt[af].mutex);
|
list_del(&target->list);
|
mutex_unlock(&xt[af].mutex);
|
}
|
EXPORT_SYMBOL(xt_unregister_target);
|
|
int
|
xt_register_targets(struct xt_target *target, unsigned int n)
|
{
|
unsigned int i;
|
int err = 0;
|
|
for (i = 0; i < n; i++) {
|
err = xt_register_target(&target[i]);
|
if (err)
|
goto err;
|
}
|
return err;
|
|
err:
|
if (i > 0)
|
xt_unregister_targets(target, i);
|
return err;
|
}
|
EXPORT_SYMBOL(xt_register_targets);
|
|
void
|
xt_unregister_targets(struct xt_target *target, unsigned int n)
|
{
|
while (n-- > 0)
|
xt_unregister_target(&target[n]);
|
}
|
EXPORT_SYMBOL(xt_unregister_targets);
|
|
int xt_register_match(struct xt_match *match)
|
{
|
u_int8_t af = match->family;
|
|
mutex_lock(&xt[af].mutex);
|
list_add(&match->list, &xt[af].match);
|
mutex_unlock(&xt[af].mutex);
|
return 0;
|
}
|
EXPORT_SYMBOL(xt_register_match);
|
|
void
|
xt_unregister_match(struct xt_match *match)
|
{
|
u_int8_t af = match->family;
|
|
mutex_lock(&xt[af].mutex);
|
list_del(&match->list);
|
mutex_unlock(&xt[af].mutex);
|
}
|
EXPORT_SYMBOL(xt_unregister_match);
|
|
int
|
xt_register_matches(struct xt_match *match, unsigned int n)
|
{
|
unsigned int i;
|
int err = 0;
|
|
for (i = 0; i < n; i++) {
|
err = xt_register_match(&match[i]);
|
if (err)
|
goto err;
|
}
|
return err;
|
|
err:
|
if (i > 0)
|
xt_unregister_matches(match, i);
|
return err;
|
}
|
EXPORT_SYMBOL(xt_register_matches);
|
|
void
|
xt_unregister_matches(struct xt_match *match, unsigned int n)
|
{
|
while (n-- > 0)
|
xt_unregister_match(&match[n]);
|
}
|
EXPORT_SYMBOL(xt_unregister_matches);
|
|
|
/*
|
* These are weird, but module loading must not be done with mutex
|
* held (since they will register), and we have to have a single
|
* function to use.
|
*/
|
|
/* Find match, grabs ref. Returns ERR_PTR() on error. */
|
struct xt_match *xt_find_match(u8 af, const char *name, u8 revision)
|
{
|
struct xt_match *m;
|
int err = -ENOENT;
|
|
if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN)
|
return ERR_PTR(-EINVAL);
|
|
mutex_lock(&xt[af].mutex);
|
list_for_each_entry(m, &xt[af].match, list) {
|
if (strcmp(m->name, name) == 0) {
|
if (m->revision == revision) {
|
if (try_module_get(m->me)) {
|
mutex_unlock(&xt[af].mutex);
|
return m;
|
}
|
} else
|
err = -EPROTOTYPE; /* Found something. */
|
}
|
}
|
mutex_unlock(&xt[af].mutex);
|
|
if (af != NFPROTO_UNSPEC)
|
/* Try searching again in the family-independent list */
|
return xt_find_match(NFPROTO_UNSPEC, name, revision);
|
|
return ERR_PTR(err);
|
}
|
EXPORT_SYMBOL(xt_find_match);
|
|
struct xt_match *
|
xt_request_find_match(uint8_t nfproto, const char *name, uint8_t revision)
|
{
|
struct xt_match *match;
|
|
if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN)
|
return ERR_PTR(-EINVAL);
|
|
match = xt_find_match(nfproto, name, revision);
|
if (IS_ERR(match)) {
|
request_module("%st_%s", xt_prefix[nfproto], name);
|
match = xt_find_match(nfproto, name, revision);
|
}
|
|
return match;
|
}
|
EXPORT_SYMBOL_GPL(xt_request_find_match);
|
|
/* Find target, grabs ref. Returns ERR_PTR() on error. */
|
static struct xt_target *xt_find_target(u8 af, const char *name, u8 revision)
|
{
|
struct xt_target *t;
|
int err = -ENOENT;
|
|
if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN)
|
return ERR_PTR(-EINVAL);
|
|
mutex_lock(&xt[af].mutex);
|
list_for_each_entry(t, &xt[af].target, list) {
|
if (strcmp(t->name, name) == 0) {
|
if (t->revision == revision) {
|
if (try_module_get(t->me)) {
|
mutex_unlock(&xt[af].mutex);
|
return t;
|
}
|
} else
|
err = -EPROTOTYPE; /* Found something. */
|
}
|
}
|
mutex_unlock(&xt[af].mutex);
|
|
if (af != NFPROTO_UNSPEC)
|
/* Try searching again in the family-independent list */
|
return xt_find_target(NFPROTO_UNSPEC, name, revision);
|
|
return ERR_PTR(err);
|
}
|
|
struct xt_target *xt_request_find_target(u8 af, const char *name, u8 revision)
|
{
|
struct xt_target *target;
|
|
if (strnlen(name, XT_EXTENSION_MAXNAMELEN) == XT_EXTENSION_MAXNAMELEN)
|
return ERR_PTR(-EINVAL);
|
|
target = xt_find_target(af, name, revision);
|
if (IS_ERR(target)) {
|
request_module("%st_%s", xt_prefix[af], name);
|
target = xt_find_target(af, name, revision);
|
}
|
|
return target;
|
}
|
EXPORT_SYMBOL_GPL(xt_request_find_target);
|
|
|
static int xt_obj_to_user(u16 __user *psize, u16 size,
|
void __user *pname, const char *name,
|
u8 __user *prev, u8 rev)
|
{
|
if (put_user(size, psize))
|
return -EFAULT;
|
if (copy_to_user(pname, name, strlen(name) + 1))
|
return -EFAULT;
|
if (put_user(rev, prev))
|
return -EFAULT;
|
|
return 0;
|
}
|
|
#define XT_OBJ_TO_USER(U, K, TYPE, C_SIZE) \
|
xt_obj_to_user(&U->u.TYPE##_size, C_SIZE ? : K->u.TYPE##_size, \
|
U->u.user.name, K->u.kernel.TYPE->name, \
|
&U->u.user.revision, K->u.kernel.TYPE->revision)
|
|
int xt_data_to_user(void __user *dst, const void *src,
|
int usersize, int size, int aligned_size)
|
{
|
usersize = usersize ? : size;
|
if (copy_to_user(dst, src, usersize))
|
return -EFAULT;
|
if (usersize != aligned_size &&
|
clear_user(dst + usersize, aligned_size - usersize))
|
return -EFAULT;
|
|
return 0;
|
}
|
EXPORT_SYMBOL_GPL(xt_data_to_user);
|
|
#define XT_DATA_TO_USER(U, K, TYPE) \
|
xt_data_to_user(U->data, K->data, \
|
K->u.kernel.TYPE->usersize, \
|
K->u.kernel.TYPE->TYPE##size, \
|
XT_ALIGN(K->u.kernel.TYPE->TYPE##size))
|
|
int xt_match_to_user(const struct xt_entry_match *m,
|
struct xt_entry_match __user *u)
|
{
|
return XT_OBJ_TO_USER(u, m, match, 0) ||
|
XT_DATA_TO_USER(u, m, match);
|
}
|
EXPORT_SYMBOL_GPL(xt_match_to_user);
|
|
int xt_target_to_user(const struct xt_entry_target *t,
|
struct xt_entry_target __user *u)
|
{
|
return XT_OBJ_TO_USER(u, t, target, 0) ||
|
XT_DATA_TO_USER(u, t, target);
|
}
|
EXPORT_SYMBOL_GPL(xt_target_to_user);
|
|
static int match_revfn(u8 af, const char *name, u8 revision, int *bestp)
|
{
|
const struct xt_match *m;
|
int have_rev = 0;
|
|
mutex_lock(&xt[af].mutex);
|
list_for_each_entry(m, &xt[af].match, list) {
|
if (strcmp(m->name, name) == 0) {
|
if (m->revision > *bestp)
|
*bestp = m->revision;
|
if (m->revision == revision)
|
have_rev = 1;
|
}
|
}
|
mutex_unlock(&xt[af].mutex);
|
|
if (af != NFPROTO_UNSPEC && !have_rev)
|
return match_revfn(NFPROTO_UNSPEC, name, revision, bestp);
|
|
return have_rev;
|
}
|
|
static int target_revfn(u8 af, const char *name, u8 revision, int *bestp)
|
{
|
const struct xt_target *t;
|
int have_rev = 0;
|
|
mutex_lock(&xt[af].mutex);
|
list_for_each_entry(t, &xt[af].target, list) {
|
if (strcmp(t->name, name) == 0) {
|
if (t->revision > *bestp)
|
*bestp = t->revision;
|
if (t->revision == revision)
|
have_rev = 1;
|
}
|
}
|
mutex_unlock(&xt[af].mutex);
|
|
if (af != NFPROTO_UNSPEC && !have_rev)
|
return target_revfn(NFPROTO_UNSPEC, name, revision, bestp);
|
|
return have_rev;
|
}
|
|
/* Returns true or false (if no such extension at all) */
|
int xt_find_revision(u8 af, const char *name, u8 revision, int target,
|
int *err)
|
{
|
int have_rev, best = -1;
|
|
if (target == 1)
|
have_rev = target_revfn(af, name, revision, &best);
|
else
|
have_rev = match_revfn(af, name, revision, &best);
|
|
/* Nothing at all? Return 0 to try loading module. */
|
if (best == -1) {
|
*err = -ENOENT;
|
return 0;
|
}
|
|
*err = best;
|
if (!have_rev)
|
*err = -EPROTONOSUPPORT;
|
return 1;
|
}
|
EXPORT_SYMBOL_GPL(xt_find_revision);
|
|
static char *
|
textify_hooks(char *buf, size_t size, unsigned int mask, uint8_t nfproto)
|
{
|
static const char *const inetbr_names[] = {
|
"PREROUTING", "INPUT", "FORWARD",
|
"OUTPUT", "POSTROUTING", "BROUTING",
|
};
|
static const char *const arp_names[] = {
|
"INPUT", "FORWARD", "OUTPUT",
|
};
|
const char *const *names;
|
unsigned int i, max;
|
char *p = buf;
|
bool np = false;
|
int res;
|
|
names = (nfproto == NFPROTO_ARP) ? arp_names : inetbr_names;
|
max = (nfproto == NFPROTO_ARP) ? ARRAY_SIZE(arp_names) :
|
ARRAY_SIZE(inetbr_names);
|
*p = '\0';
|
for (i = 0; i < max; ++i) {
|
if (!(mask & (1 << i)))
|
continue;
|
res = snprintf(p, size, "%s%s", np ? "/" : "", names[i]);
|
if (res > 0) {
|
size -= res;
|
p += res;
|
}
|
np = true;
|
}
|
|
return buf;
|
}
|
|
/**
|
* xt_check_proc_name - check that name is suitable for /proc file creation
|
*
|
* @name: file name candidate
|
* @size: length of buffer
|
*
|
* some x_tables modules wish to create a file in /proc.
|
* This function makes sure that the name is suitable for this
|
* purpose, it checks that name is NUL terminated and isn't a 'special'
|
* name, like "..".
|
*
|
* returns negative number on error or 0 if name is useable.
|
*/
|
int xt_check_proc_name(const char *name, unsigned int size)
|
{
|
if (name[0] == '\0')
|
return -EINVAL;
|
|
if (strnlen(name, size) == size)
|
return -ENAMETOOLONG;
|
|
if (strcmp(name, ".") == 0 ||
|
strcmp(name, "..") == 0 ||
|
strchr(name, '/'))
|
return -EINVAL;
|
|
return 0;
|
}
|
EXPORT_SYMBOL(xt_check_proc_name);
|
|
int xt_check_match(struct xt_mtchk_param *par,
|
unsigned int size, u16 proto, bool inv_proto)
|
{
|
int ret;
|
|
if (XT_ALIGN(par->match->matchsize) != size &&
|
par->match->matchsize != -1) {
|
/*
|
* ebt_among is exempt from centralized matchsize checking
|
* because it uses a dynamic-size data set.
|
*/
|
pr_err_ratelimited("%s_tables: %s.%u match: invalid size %u (kernel) != (user) %u\n",
|
xt_prefix[par->family], par->match->name,
|
par->match->revision,
|
XT_ALIGN(par->match->matchsize), size);
|
return -EINVAL;
|
}
|
if (par->match->table != NULL &&
|
strcmp(par->match->table, par->table) != 0) {
|
pr_info_ratelimited("%s_tables: %s match: only valid in %s table, not %s\n",
|
xt_prefix[par->family], par->match->name,
|
par->match->table, par->table);
|
return -EINVAL;
|
}
|
if (par->match->hooks && (par->hook_mask & ~par->match->hooks) != 0) {
|
char used[64], allow[64];
|
|
pr_info_ratelimited("%s_tables: %s match: used from hooks %s, but only valid from %s\n",
|
xt_prefix[par->family], par->match->name,
|
textify_hooks(used, sizeof(used),
|
par->hook_mask, par->family),
|
textify_hooks(allow, sizeof(allow),
|
par->match->hooks,
|
par->family));
|
return -EINVAL;
|
}
|
if (par->match->proto && (par->match->proto != proto || inv_proto)) {
|
pr_info_ratelimited("%s_tables: %s match: only valid for protocol %u\n",
|
xt_prefix[par->family], par->match->name,
|
par->match->proto);
|
return -EINVAL;
|
}
|
if (par->match->checkentry != NULL) {
|
ret = par->match->checkentry(par);
|
if (ret < 0)
|
return ret;
|
else if (ret > 0)
|
/* Flag up potential errors. */
|
return -EIO;
|
}
|
return 0;
|
}
|
EXPORT_SYMBOL_GPL(xt_check_match);
|
|
/** xt_check_entry_match - check that matches end before start of target
|
*
|
* @match: beginning of xt_entry_match
|
* @target: beginning of this rules target (alleged end of matches)
|
* @alignment: alignment requirement of match structures
|
*
|
* Validates that all matches add up to the beginning of the target,
|
* and that each match covers at least the base structure size.
|
*
|
* Return: 0 on success, negative errno on failure.
|
*/
|
static int xt_check_entry_match(const char *match, const char *target,
|
const size_t alignment)
|
{
|
const struct xt_entry_match *pos;
|
int length = target - match;
|
|
if (length == 0) /* no matches */
|
return 0;
|
|
pos = (struct xt_entry_match *)match;
|
do {
|
if ((unsigned long)pos % alignment)
|
return -EINVAL;
|
|
if (length < (int)sizeof(struct xt_entry_match))
|
return -EINVAL;
|
|
if (pos->u.match_size < sizeof(struct xt_entry_match))
|
return -EINVAL;
|
|
if (pos->u.match_size > length)
|
return -EINVAL;
|
|
length -= pos->u.match_size;
|
pos = ((void *)((char *)(pos) + (pos)->u.match_size));
|
} while (length > 0);
|
|
return 0;
|
}
|
|
/** xt_check_table_hooks - check hook entry points are sane
|
*
|
* @info xt_table_info to check
|
* @valid_hooks - hook entry points that we can enter from
|
*
|
* Validates that the hook entry and underflows points are set up.
|
*
|
* Return: 0 on success, negative errno on failure.
|
*/
|
int xt_check_table_hooks(const struct xt_table_info *info, unsigned int valid_hooks)
|
{
|
const char *err = "unsorted underflow";
|
unsigned int i, max_uflow, max_entry;
|
bool check_hooks = false;
|
|
BUILD_BUG_ON(ARRAY_SIZE(info->hook_entry) != ARRAY_SIZE(info->underflow));
|
|
max_entry = 0;
|
max_uflow = 0;
|
|
for (i = 0; i < ARRAY_SIZE(info->hook_entry); i++) {
|
if (!(valid_hooks & (1 << i)))
|
continue;
|
|
if (info->hook_entry[i] == 0xFFFFFFFF)
|
return -EINVAL;
|
if (info->underflow[i] == 0xFFFFFFFF)
|
return -EINVAL;
|
|
if (check_hooks) {
|
if (max_uflow > info->underflow[i])
|
goto error;
|
|
if (max_uflow == info->underflow[i]) {
|
err = "duplicate underflow";
|
goto error;
|
}
|
if (max_entry > info->hook_entry[i]) {
|
err = "unsorted entry";
|
goto error;
|
}
|
if (max_entry == info->hook_entry[i]) {
|
err = "duplicate entry";
|
goto error;
|
}
|
}
|
max_entry = info->hook_entry[i];
|
max_uflow = info->underflow[i];
|
check_hooks = true;
|
}
|
|
return 0;
|
error:
|
pr_err_ratelimited("%s at hook %d\n", err, i);
|
return -EINVAL;
|
}
|
EXPORT_SYMBOL(xt_check_table_hooks);
|
|
static bool verdict_ok(int verdict)
|
{
|
if (verdict > 0)
|
return true;
|
|
if (verdict < 0) {
|
int v = -verdict - 1;
|
|
if (verdict == XT_RETURN)
|
return true;
|
|
switch (v) {
|
case NF_ACCEPT: return true;
|
case NF_DROP: return true;
|
case NF_QUEUE: return true;
|
default:
|
break;
|
}
|
|
return false;
|
}
|
|
return false;
|
}
|
|
static bool error_tg_ok(unsigned int usersize, unsigned int kernsize,
|
const char *msg, unsigned int msglen)
|
{
|
return usersize == kernsize && strnlen(msg, msglen) < msglen;
|
}
|
|
#ifdef CONFIG_COMPAT
|
int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta)
|
{
|
struct xt_af *xp = &xt[af];
|
|
WARN_ON(!mutex_is_locked(&xt[af].compat_mutex));
|
|
if (WARN_ON(!xp->compat_tab))
|
return -ENOMEM;
|
|
if (xp->cur >= xp->number)
|
return -EINVAL;
|
|
if (xp->cur)
|
delta += xp->compat_tab[xp->cur - 1].delta;
|
xp->compat_tab[xp->cur].offset = offset;
|
xp->compat_tab[xp->cur].delta = delta;
|
xp->cur++;
|
return 0;
|
}
|
EXPORT_SYMBOL_GPL(xt_compat_add_offset);
|
|
void xt_compat_flush_offsets(u_int8_t af)
|
{
|
WARN_ON(!mutex_is_locked(&xt[af].compat_mutex));
|
|
if (xt[af].compat_tab) {
|
vfree(xt[af].compat_tab);
|
xt[af].compat_tab = NULL;
|
xt[af].number = 0;
|
xt[af].cur = 0;
|
}
|
}
|
EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
|
|
int xt_compat_calc_jump(u_int8_t af, unsigned int offset)
|
{
|
struct compat_delta *tmp = xt[af].compat_tab;
|
int mid, left = 0, right = xt[af].cur - 1;
|
|
while (left <= right) {
|
mid = (left + right) >> 1;
|
if (offset > tmp[mid].offset)
|
left = mid + 1;
|
else if (offset < tmp[mid].offset)
|
right = mid - 1;
|
else
|
return mid ? tmp[mid - 1].delta : 0;
|
}
|
return left ? tmp[left - 1].delta : 0;
|
}
|
EXPORT_SYMBOL_GPL(xt_compat_calc_jump);
|
|
int xt_compat_init_offsets(u8 af, unsigned int number)
|
{
|
size_t mem;
|
|
WARN_ON(!mutex_is_locked(&xt[af].compat_mutex));
|
|
if (!number || number > (INT_MAX / sizeof(struct compat_delta)))
|
return -EINVAL;
|
|
if (WARN_ON(xt[af].compat_tab))
|
return -EINVAL;
|
|
mem = sizeof(struct compat_delta) * number;
|
if (mem > XT_MAX_TABLE_SIZE)
|
return -ENOMEM;
|
|
xt[af].compat_tab = vmalloc(mem);
|
if (!xt[af].compat_tab)
|
return -ENOMEM;
|
|
xt[af].number = number;
|
xt[af].cur = 0;
|
|
return 0;
|
}
|
EXPORT_SYMBOL(xt_compat_init_offsets);
|
|
int xt_compat_match_offset(const struct xt_match *match)
|
{
|
u_int16_t csize = match->compatsize ? : match->matchsize;
|
return XT_ALIGN(match->matchsize) - COMPAT_XT_ALIGN(csize);
|
}
|
EXPORT_SYMBOL_GPL(xt_compat_match_offset);
|
|
void xt_compat_match_from_user(struct xt_entry_match *m, void **dstptr,
|
unsigned int *size)
|
{
|
const struct xt_match *match = m->u.kernel.match;
|
struct compat_xt_entry_match *cm = (struct compat_xt_entry_match *)m;
|
int off = xt_compat_match_offset(match);
|
u_int16_t msize = cm->u.user.match_size;
|
char name[sizeof(m->u.user.name)];
|
|
m = *dstptr;
|
memcpy(m, cm, sizeof(*cm));
|
if (match->compat_from_user)
|
match->compat_from_user(m->data, cm->data);
|
else
|
memcpy(m->data, cm->data, msize - sizeof(*cm));
|
|
msize += off;
|
m->u.user.match_size = msize;
|
strlcpy(name, match->name, sizeof(name));
|
module_put(match->me);
|
strncpy(m->u.user.name, name, sizeof(m->u.user.name));
|
|
*size += off;
|
*dstptr += msize;
|
}
|
EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
|
|
#define COMPAT_XT_DATA_TO_USER(U, K, TYPE, C_SIZE) \
|
xt_data_to_user(U->data, K->data, \
|
K->u.kernel.TYPE->usersize, \
|
C_SIZE, \
|
COMPAT_XT_ALIGN(C_SIZE))
|
|
int xt_compat_match_to_user(const struct xt_entry_match *m,
|
void __user **dstptr, unsigned int *size)
|
{
|
const struct xt_match *match = m->u.kernel.match;
|
struct compat_xt_entry_match __user *cm = *dstptr;
|
int off = xt_compat_match_offset(match);
|
u_int16_t msize = m->u.user.match_size - off;
|
|
if (XT_OBJ_TO_USER(cm, m, match, msize))
|
return -EFAULT;
|
|
if (match->compat_to_user) {
|
if (match->compat_to_user((void __user *)cm->data, m->data))
|
return -EFAULT;
|
} else {
|
if (COMPAT_XT_DATA_TO_USER(cm, m, match, msize - sizeof(*cm)))
|
return -EFAULT;
|
}
|
|
*size -= off;
|
*dstptr += msize;
|
return 0;
|
}
|
EXPORT_SYMBOL_GPL(xt_compat_match_to_user);
|
|
/* non-compat version may have padding after verdict */
|
struct compat_xt_standard_target {
|
struct compat_xt_entry_target t;
|
compat_uint_t verdict;
|
};
|
|
struct compat_xt_error_target {
|
struct compat_xt_entry_target t;
|
char errorname[XT_FUNCTION_MAXNAMELEN];
|
};
|
|
int xt_compat_check_entry_offsets(const void *base, const char *elems,
|
unsigned int target_offset,
|
unsigned int next_offset)
|
{
|
long size_of_base_struct = elems - (const char *)base;
|
const struct compat_xt_entry_target *t;
|
const char *e = base;
|
|
if (target_offset < size_of_base_struct)
|
return -EINVAL;
|
|
if (target_offset + sizeof(*t) > next_offset)
|
return -EINVAL;
|
|
t = (void *)(e + target_offset);
|
if (t->u.target_size < sizeof(*t))
|
return -EINVAL;
|
|
if (target_offset + t->u.target_size > next_offset)
|
return -EINVAL;
|
|
if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0) {
|
const struct compat_xt_standard_target *st = (const void *)t;
|
|
if (COMPAT_XT_ALIGN(target_offset + sizeof(*st)) != next_offset)
|
return -EINVAL;
|
|
if (!verdict_ok(st->verdict))
|
return -EINVAL;
|
} else if (strcmp(t->u.user.name, XT_ERROR_TARGET) == 0) {
|
const struct compat_xt_error_target *et = (const void *)t;
|
|
if (!error_tg_ok(t->u.target_size, sizeof(*et),
|
et->errorname, sizeof(et->errorname)))
|
return -EINVAL;
|
}
|
|
/* compat_xt_entry match has less strict alignment requirements,
|
* otherwise they are identical. In case of padding differences
|
* we need to add compat version of xt_check_entry_match.
|
*/
|
BUILD_BUG_ON(sizeof(struct compat_xt_entry_match) != sizeof(struct xt_entry_match));
|
|
return xt_check_entry_match(elems, base + target_offset,
|
__alignof__(struct compat_xt_entry_match));
|
}
|
EXPORT_SYMBOL(xt_compat_check_entry_offsets);
|
#endif /* CONFIG_COMPAT */
|
|
/**
|
* xt_check_entry_offsets - validate arp/ip/ip6t_entry
|
*
|
* @base: pointer to arp/ip/ip6t_entry
|
* @elems: pointer to first xt_entry_match, i.e. ip(6)t_entry->elems
|
* @target_offset: the arp/ip/ip6_t->target_offset
|
* @next_offset: the arp/ip/ip6_t->next_offset
|
*
|
* validates that target_offset and next_offset are sane and that all
|
* match sizes (if any) align with the target offset.
|
*
|
* This function does not validate the targets or matches themselves, it
|
* only tests that all the offsets and sizes are correct, that all
|
* match structures are aligned, and that the last structure ends where
|
* the target structure begins.
|
*
|
* Also see xt_compat_check_entry_offsets for CONFIG_COMPAT version.
|
*
|
* The arp/ip/ip6t_entry structure @base must have passed following tests:
|
* - it must point to a valid memory location
|
* - base to base + next_offset must be accessible, i.e. not exceed allocated
|
* length.
|
*
|
* A well-formed entry looks like this:
|
*
|
* ip(6)t_entry match [mtdata] match [mtdata] target [tgdata] ip(6)t_entry
|
* e->elems[]-----' | |
|
* matchsize | |
|
* matchsize | |
|
* | |
|
* target_offset---------------------------------' |
|
* next_offset---------------------------------------------------'
|
*
|
* elems[]: flexible array member at end of ip(6)/arpt_entry struct.
|
* This is where matches (if any) and the target reside.
|
* target_offset: beginning of target.
|
* next_offset: start of the next rule; also: size of this rule.
|
* Since targets have a minimum size, target_offset + minlen <= next_offset.
|
*
|
* Every match stores its size, sum of sizes must not exceed target_offset.
|
*
|
* Return: 0 on success, negative errno on failure.
|
*/
|
int xt_check_entry_offsets(const void *base,
|
const char *elems,
|
unsigned int target_offset,
|
unsigned int next_offset)
|
{
|
long size_of_base_struct = elems - (const char *)base;
|
const struct xt_entry_target *t;
|
const char *e = base;
|
|
/* target start is within the ip/ip6/arpt_entry struct */
|
if (target_offset < size_of_base_struct)
|
return -EINVAL;
|
|
if (target_offset + sizeof(*t) > next_offset)
|
return -EINVAL;
|
|
t = (void *)(e + target_offset);
|
if (t->u.target_size < sizeof(*t))
|
return -EINVAL;
|
|
if (target_offset + t->u.target_size > next_offset)
|
return -EINVAL;
|
|
if (strcmp(t->u.user.name, XT_STANDARD_TARGET) == 0) {
|
const struct xt_standard_target *st = (const void *)t;
|
|
if (XT_ALIGN(target_offset + sizeof(*st)) != next_offset)
|
return -EINVAL;
|
|
if (!verdict_ok(st->verdict))
|
return -EINVAL;
|
} else if (strcmp(t->u.user.name, XT_ERROR_TARGET) == 0) {
|
const struct xt_error_target *et = (const void *)t;
|
|
if (!error_tg_ok(t->u.target_size, sizeof(*et),
|
et->errorname, sizeof(et->errorname)))
|
return -EINVAL;
|
}
|
|
return xt_check_entry_match(elems, base + target_offset,
|
__alignof__(struct xt_entry_match));
|
}
|
EXPORT_SYMBOL(xt_check_entry_offsets);
|
|
/**
|
* xt_alloc_entry_offsets - allocate array to store rule head offsets
|
*
|
* @size: number of entries
|
*
|
* Return: NULL or zeroed kmalloc'd or vmalloc'd array
|
*/
|
unsigned int *xt_alloc_entry_offsets(unsigned int size)
|
{
|
if (size > XT_MAX_TABLE_SIZE / sizeof(unsigned int))
|
return NULL;
|
|
return kvcalloc(size, sizeof(unsigned int), GFP_KERNEL);
|
|
}
|
EXPORT_SYMBOL(xt_alloc_entry_offsets);
|
|
/**
|
* xt_find_jump_offset - check if target is a valid jump offset
|
*
|
* @offsets: array containing all valid rule start offsets of a rule blob
|
* @target: the jump target to search for
|
* @size: entries in @offset
|
*/
|
bool xt_find_jump_offset(const unsigned int *offsets,
|
unsigned int target, unsigned int size)
|
{
|
int m, low = 0, hi = size;
|
|
while (hi > low) {
|
m = (low + hi) / 2u;
|
|
if (offsets[m] > target)
|
hi = m;
|
else if (offsets[m] < target)
|
low = m + 1;
|
else
|
return true;
|
}
|
|
return false;
|
}
|
EXPORT_SYMBOL(xt_find_jump_offset);
|
|
int xt_check_target(struct xt_tgchk_param *par,
|
unsigned int size, u16 proto, bool inv_proto)
|
{
|
int ret;
|
|
if (XT_ALIGN(par->target->targetsize) != size) {
|
pr_err_ratelimited("%s_tables: %s.%u target: invalid size %u (kernel) != (user) %u\n",
|
xt_prefix[par->family], par->target->name,
|
par->target->revision,
|
XT_ALIGN(par->target->targetsize), size);
|
return -EINVAL;
|
}
|
if (par->target->table != NULL &&
|
strcmp(par->target->table, par->table) != 0) {
|
pr_info_ratelimited("%s_tables: %s target: only valid in %s table, not %s\n",
|
xt_prefix[par->family], par->target->name,
|
par->target->table, par->table);
|
return -EINVAL;
|
}
|
if (par->target->hooks && (par->hook_mask & ~par->target->hooks) != 0) {
|
char used[64], allow[64];
|
|
pr_info_ratelimited("%s_tables: %s target: used from hooks %s, but only usable from %s\n",
|
xt_prefix[par->family], par->target->name,
|
textify_hooks(used, sizeof(used),
|
par->hook_mask, par->family),
|
textify_hooks(allow, sizeof(allow),
|
par->target->hooks,
|
par->family));
|
return -EINVAL;
|
}
|
if (par->target->proto && (par->target->proto != proto || inv_proto)) {
|
pr_info_ratelimited("%s_tables: %s target: only valid for protocol %u\n",
|
xt_prefix[par->family], par->target->name,
|
par->target->proto);
|
return -EINVAL;
|
}
|
if (par->target->checkentry != NULL) {
|
ret = par->target->checkentry(par);
|
if (ret < 0)
|
return ret;
|
else if (ret > 0)
|
/* Flag up potential errors. */
|
return -EIO;
|
}
|
return 0;
|
}
|
EXPORT_SYMBOL_GPL(xt_check_target);
|
|
/**
|
* xt_copy_counters - copy counters and metadata from a sockptr_t
|
*
|
* @arg: src sockptr
|
* @len: alleged size of userspace memory
|
* @info: where to store the xt_counters_info metadata
|
*
|
* Copies counter meta data from @user and stores it in @info.
|
*
|
* vmallocs memory to hold the counters, then copies the counter data
|
* from @user to the new memory and returns a pointer to it.
|
*
|
* If called from a compat syscall, @info gets converted automatically to the
|
* 64bit representation.
|
*
|
* The metadata associated with the counters is stored in @info.
|
*
|
* Return: returns pointer that caller has to test via IS_ERR().
|
* If IS_ERR is false, caller has to vfree the pointer.
|
*/
|
void *xt_copy_counters(sockptr_t arg, unsigned int len,
|
struct xt_counters_info *info)
|
{
|
size_t offset;
|
void *mem;
|
u64 size;
|
|
#ifdef CONFIG_COMPAT
|
if (in_compat_syscall()) {
|
/* structures only differ in size due to alignment */
|
struct compat_xt_counters_info compat_tmp;
|
|
if (len <= sizeof(compat_tmp))
|
return ERR_PTR(-EINVAL);
|
|
len -= sizeof(compat_tmp);
|
if (copy_from_sockptr(&compat_tmp, arg, sizeof(compat_tmp)) != 0)
|
return ERR_PTR(-EFAULT);
|
|
memcpy(info->name, compat_tmp.name, sizeof(info->name) - 1);
|
info->num_counters = compat_tmp.num_counters;
|
offset = sizeof(compat_tmp);
|
} else
|
#endif
|
{
|
if (len <= sizeof(*info))
|
return ERR_PTR(-EINVAL);
|
|
len -= sizeof(*info);
|
if (copy_from_sockptr(info, arg, sizeof(*info)) != 0)
|
return ERR_PTR(-EFAULT);
|
|
offset = sizeof(*info);
|
}
|
info->name[sizeof(info->name) - 1] = '\0';
|
|
size = sizeof(struct xt_counters);
|
size *= info->num_counters;
|
|
if (size != (u64)len)
|
return ERR_PTR(-EINVAL);
|
|
mem = vmalloc(len);
|
if (!mem)
|
return ERR_PTR(-ENOMEM);
|
|
if (copy_from_sockptr_offset(mem, arg, offset, len) == 0)
|
return mem;
|
|
vfree(mem);
|
return ERR_PTR(-EFAULT);
|
}
|
EXPORT_SYMBOL_GPL(xt_copy_counters);
|
|
#ifdef CONFIG_COMPAT
|
int xt_compat_target_offset(const struct xt_target *target)
|
{
|
u_int16_t csize = target->compatsize ? : target->targetsize;
|
return XT_ALIGN(target->targetsize) - COMPAT_XT_ALIGN(csize);
|
}
|
EXPORT_SYMBOL_GPL(xt_compat_target_offset);
|
|
void xt_compat_target_from_user(struct xt_entry_target *t, void **dstptr,
|
unsigned int *size)
|
{
|
const struct xt_target *target = t->u.kernel.target;
|
struct compat_xt_entry_target *ct = (struct compat_xt_entry_target *)t;
|
int off = xt_compat_target_offset(target);
|
u_int16_t tsize = ct->u.user.target_size;
|
char name[sizeof(t->u.user.name)];
|
|
t = *dstptr;
|
memcpy(t, ct, sizeof(*ct));
|
if (target->compat_from_user)
|
target->compat_from_user(t->data, ct->data);
|
else
|
memcpy(t->data, ct->data, tsize - sizeof(*ct));
|
|
tsize += off;
|
t->u.user.target_size = tsize;
|
strlcpy(name, target->name, sizeof(name));
|
module_put(target->me);
|
strncpy(t->u.user.name, name, sizeof(t->u.user.name));
|
|
*size += off;
|
*dstptr += tsize;
|
}
|
EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
|
|
int xt_compat_target_to_user(const struct xt_entry_target *t,
|
void __user **dstptr, unsigned int *size)
|
{
|
const struct xt_target *target = t->u.kernel.target;
|
struct compat_xt_entry_target __user *ct = *dstptr;
|
int off = xt_compat_target_offset(target);
|
u_int16_t tsize = t->u.user.target_size - off;
|
|
if (XT_OBJ_TO_USER(ct, t, target, tsize))
|
return -EFAULT;
|
|
if (target->compat_to_user) {
|
if (target->compat_to_user((void __user *)ct->data, t->data))
|
return -EFAULT;
|
} else {
|
if (COMPAT_XT_DATA_TO_USER(ct, t, target, tsize - sizeof(*ct)))
|
return -EFAULT;
|
}
|
|
*size -= off;
|
*dstptr += tsize;
|
return 0;
|
}
|
EXPORT_SYMBOL_GPL(xt_compat_target_to_user);
|
#endif
|
|
struct xt_table_info *xt_alloc_table_info(unsigned int size)
|
{
|
struct xt_table_info *info = NULL;
|
size_t sz = sizeof(*info) + size;
|
|
if (sz < sizeof(*info) || sz >= XT_MAX_TABLE_SIZE)
|
return NULL;
|
|
info = kvmalloc(sz, GFP_KERNEL_ACCOUNT);
|
if (!info)
|
return NULL;
|
|
memset(info, 0, sizeof(*info));
|
info->size = size;
|
return info;
|
}
|
EXPORT_SYMBOL(xt_alloc_table_info);
|
|
void xt_free_table_info(struct xt_table_info *info)
|
{
|
int cpu;
|
|
if (info->jumpstack != NULL) {
|
for_each_possible_cpu(cpu)
|
kvfree(info->jumpstack[cpu]);
|
kvfree(info->jumpstack);
|
}
|
|
kvfree(info);
|
}
|
EXPORT_SYMBOL(xt_free_table_info);
|
|
/* Find table by name, grabs mutex & ref. Returns ERR_PTR on error. */
|
struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
|
const char *name)
|
{
|
struct xt_table *t, *found = NULL;
|
|
mutex_lock(&xt[af].mutex);
|
list_for_each_entry(t, &net->xt.tables[af], list)
|
if (strcmp(t->name, name) == 0 && try_module_get(t->me))
|
return t;
|
|
if (net == &init_net)
|
goto out;
|
|
/* Table doesn't exist in this netns, re-try init */
|
list_for_each_entry(t, &init_net.xt.tables[af], list) {
|
int err;
|
|
if (strcmp(t->name, name))
|
continue;
|
if (!try_module_get(t->me))
|
goto out;
|
mutex_unlock(&xt[af].mutex);
|
err = t->table_init(net);
|
if (err < 0) {
|
module_put(t->me);
|
return ERR_PTR(err);
|
}
|
|
found = t;
|
|
mutex_lock(&xt[af].mutex);
|
break;
|
}
|
|
if (!found)
|
goto out;
|
|
/* and once again: */
|
list_for_each_entry(t, &net->xt.tables[af], list)
|
if (strcmp(t->name, name) == 0)
|
return t;
|
|
module_put(found->me);
|
out:
|
mutex_unlock(&xt[af].mutex);
|
return ERR_PTR(-ENOENT);
|
}
|
EXPORT_SYMBOL_GPL(xt_find_table_lock);
|
|
struct xt_table *xt_request_find_table_lock(struct net *net, u_int8_t af,
|
const char *name)
|
{
|
struct xt_table *t = xt_find_table_lock(net, af, name);
|
|
#ifdef CONFIG_MODULES
|
if (IS_ERR(t)) {
|
int err = request_module("%stable_%s", xt_prefix[af], name);
|
if (err < 0)
|
return ERR_PTR(err);
|
t = xt_find_table_lock(net, af, name);
|
}
|
#endif
|
|
return t;
|
}
|
EXPORT_SYMBOL_GPL(xt_request_find_table_lock);
|
|
void xt_table_unlock(struct xt_table *table)
|
{
|
mutex_unlock(&xt[table->af].mutex);
|
}
|
EXPORT_SYMBOL_GPL(xt_table_unlock);
|
|
#ifdef CONFIG_COMPAT
|
void xt_compat_lock(u_int8_t af)
|
{
|
mutex_lock(&xt[af].compat_mutex);
|
}
|
EXPORT_SYMBOL_GPL(xt_compat_lock);
|
|
void xt_compat_unlock(u_int8_t af)
|
{
|
mutex_unlock(&xt[af].compat_mutex);
|
}
|
EXPORT_SYMBOL_GPL(xt_compat_unlock);
|
#endif
|
|
DEFINE_PER_CPU(seqcount_t, xt_recseq);
|
EXPORT_PER_CPU_SYMBOL_GPL(xt_recseq);
|
|
struct static_key xt_tee_enabled __read_mostly;
|
EXPORT_SYMBOL_GPL(xt_tee_enabled);
|
|
static int xt_jumpstack_alloc(struct xt_table_info *i)
|
{
|
unsigned int size;
|
int cpu;
|
|
size = sizeof(void **) * nr_cpu_ids;
|
if (size > PAGE_SIZE)
|
i->jumpstack = kvzalloc(size, GFP_KERNEL);
|
else
|
i->jumpstack = kzalloc(size, GFP_KERNEL);
|
if (i->jumpstack == NULL)
|
return -ENOMEM;
|
|
/* ruleset without jumps -- no stack needed */
|
if (i->stacksize == 0)
|
return 0;
|
|
/* Jumpstack needs to be able to record two full callchains, one
|
* from the first rule set traversal, plus one table reentrancy
|
* via -j TEE without clobbering the callchain that brought us to
|
* TEE target.
|
*
|
* This is done by allocating two jumpstacks per cpu, on reentry
|
* the upper half of the stack is used.
|
*
|
* see the jumpstack setup in ipt_do_table() for more details.
|
*/
|
size = sizeof(void *) * i->stacksize * 2u;
|
for_each_possible_cpu(cpu) {
|
i->jumpstack[cpu] = kvmalloc_node(size, GFP_KERNEL,
|
cpu_to_node(cpu));
|
if (i->jumpstack[cpu] == NULL)
|
/*
|
* Freeing will be done later on by the callers. The
|
* chain is: xt_replace_table -> __do_replace ->
|
* do_replace -> xt_free_table_info.
|
*/
|
return -ENOMEM;
|
}
|
|
return 0;
|
}
|
|
struct xt_counters *xt_counters_alloc(unsigned int counters)
|
{
|
struct xt_counters *mem;
|
|
if (counters == 0 || counters > INT_MAX / sizeof(*mem))
|
return NULL;
|
|
counters *= sizeof(*mem);
|
if (counters > XT_MAX_TABLE_SIZE)
|
return NULL;
|
|
return vzalloc(counters);
|
}
|
EXPORT_SYMBOL(xt_counters_alloc);
|
|
struct xt_table_info *
|
xt_replace_table(struct xt_table *table,
|
unsigned int num_counters,
|
struct xt_table_info *newinfo,
|
int *error)
|
{
|
struct xt_table_info *private;
|
unsigned int cpu;
|
int ret;
|
|
ret = xt_jumpstack_alloc(newinfo);
|
if (ret < 0) {
|
*error = ret;
|
return NULL;
|
}
|
|
/* Do the substitution. */
|
local_bh_disable();
|
private = table->private;
|
|
/* Check inside lock: is the old number correct? */
|
if (num_counters != private->number) {
|
pr_debug("num_counters != table->private->number (%u/%u)\n",
|
num_counters, private->number);
|
local_bh_enable();
|
*error = -EAGAIN;
|
return NULL;
|
}
|
|
newinfo->initial_entries = private->initial_entries;
|
/*
|
* Ensure contents of newinfo are visible before assigning to
|
* private.
|
*/
|
smp_wmb();
|
table->private = newinfo;
|
|
/* make sure all cpus see new ->private value */
|
smp_mb();
|
|
/*
|
* Even though table entries have now been swapped, other CPU's
|
* may still be using the old entries...
|
*/
|
local_bh_enable();
|
|
/* ... so wait for even xt_recseq on all cpus */
|
for_each_possible_cpu(cpu) {
|
seqcount_t *s = &per_cpu(xt_recseq, cpu);
|
u32 seq = raw_read_seqcount(s);
|
|
if (seq & 1) {
|
do {
|
cond_resched();
|
cpu_relax();
|
} while (seq == raw_read_seqcount(s));
|
}
|
}
|
|
audit_log_nfcfg(table->name, table->af, private->number,
|
!private->number ? AUDIT_XT_OP_REGISTER :
|
AUDIT_XT_OP_REPLACE,
|
GFP_KERNEL);
|
return private;
|
}
|
EXPORT_SYMBOL_GPL(xt_replace_table);
|
|
struct xt_table *xt_register_table(struct net *net,
|
const struct xt_table *input_table,
|
struct xt_table_info *bootstrap,
|
struct xt_table_info *newinfo)
|
{
|
int ret;
|
struct xt_table_info *private;
|
struct xt_table *t, *table;
|
|
/* Don't add one object to multiple lists. */
|
table = kmemdup(input_table, sizeof(struct xt_table), GFP_KERNEL);
|
if (!table) {
|
ret = -ENOMEM;
|
goto out;
|
}
|
|
mutex_lock(&xt[table->af].mutex);
|
/* Don't autoload: we'd eat our tail... */
|
list_for_each_entry(t, &net->xt.tables[table->af], list) {
|
if (strcmp(t->name, table->name) == 0) {
|
ret = -EEXIST;
|
goto unlock;
|
}
|
}
|
|
/* Simplifies replace_table code. */
|
table->private = bootstrap;
|
|
if (!xt_replace_table(table, 0, newinfo, &ret))
|
goto unlock;
|
|
private = table->private;
|
pr_debug("table->private->number = %u\n", private->number);
|
|
/* save number of initial entries */
|
private->initial_entries = private->number;
|
|
list_add(&table->list, &net->xt.tables[table->af]);
|
mutex_unlock(&xt[table->af].mutex);
|
return table;
|
|
unlock:
|
mutex_unlock(&xt[table->af].mutex);
|
kfree(table);
|
out:
|
return ERR_PTR(ret);
|
}
|
EXPORT_SYMBOL_GPL(xt_register_table);
|
|
void *xt_unregister_table(struct xt_table *table)
|
{
|
struct xt_table_info *private;
|
|
mutex_lock(&xt[table->af].mutex);
|
private = table->private;
|
list_del(&table->list);
|
mutex_unlock(&xt[table->af].mutex);
|
audit_log_nfcfg(table->name, table->af, private->number,
|
AUDIT_XT_OP_UNREGISTER, GFP_KERNEL);
|
kfree(table);
|
|
return private;
|
}
|
EXPORT_SYMBOL_GPL(xt_unregister_table);
|
|
#ifdef CONFIG_PROC_FS
|
static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
|
{
|
struct net *net = seq_file_net(seq);
|
u_int8_t af = (unsigned long)PDE_DATA(file_inode(seq->file));
|
|
mutex_lock(&xt[af].mutex);
|
return seq_list_start(&net->xt.tables[af], *pos);
|
}
|
|
static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
{
|
struct net *net = seq_file_net(seq);
|
u_int8_t af = (unsigned long)PDE_DATA(file_inode(seq->file));
|
|
return seq_list_next(v, &net->xt.tables[af], pos);
|
}
|
|
static void xt_table_seq_stop(struct seq_file *seq, void *v)
|
{
|
u_int8_t af = (unsigned long)PDE_DATA(file_inode(seq->file));
|
|
mutex_unlock(&xt[af].mutex);
|
}
|
|
static int xt_table_seq_show(struct seq_file *seq, void *v)
|
{
|
struct xt_table *table = list_entry(v, struct xt_table, list);
|
|
if (*table->name)
|
seq_printf(seq, "%s\n", table->name);
|
return 0;
|
}
|
|
static const struct seq_operations xt_table_seq_ops = {
|
.start = xt_table_seq_start,
|
.next = xt_table_seq_next,
|
.stop = xt_table_seq_stop,
|
.show = xt_table_seq_show,
|
};
|
|
/*
|
* Traverse state for ip{,6}_{tables,matches} for helping crossing
|
* the multi-AF mutexes.
|
*/
|
struct nf_mttg_trav {
|
struct list_head *head, *curr;
|
uint8_t class;
|
};
|
|
enum {
|
MTTG_TRAV_INIT,
|
MTTG_TRAV_NFP_UNSPEC,
|
MTTG_TRAV_NFP_SPEC,
|
MTTG_TRAV_DONE,
|
};
|
|
static void *xt_mttg_seq_next(struct seq_file *seq, void *v, loff_t *ppos,
|
bool is_target)
|
{
|
static const uint8_t next_class[] = {
|
[MTTG_TRAV_NFP_UNSPEC] = MTTG_TRAV_NFP_SPEC,
|
[MTTG_TRAV_NFP_SPEC] = MTTG_TRAV_DONE,
|
};
|
uint8_t nfproto = (unsigned long)PDE_DATA(file_inode(seq->file));
|
struct nf_mttg_trav *trav = seq->private;
|
|
if (ppos != NULL)
|
++(*ppos);
|
|
switch (trav->class) {
|
case MTTG_TRAV_INIT:
|
trav->class = MTTG_TRAV_NFP_UNSPEC;
|
mutex_lock(&xt[NFPROTO_UNSPEC].mutex);
|
trav->head = trav->curr = is_target ?
|
&xt[NFPROTO_UNSPEC].target : &xt[NFPROTO_UNSPEC].match;
|
break;
|
case MTTG_TRAV_NFP_UNSPEC:
|
trav->curr = trav->curr->next;
|
if (trav->curr != trav->head)
|
break;
|
mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
|
mutex_lock(&xt[nfproto].mutex);
|
trav->head = trav->curr = is_target ?
|
&xt[nfproto].target : &xt[nfproto].match;
|
trav->class = next_class[trav->class];
|
break;
|
case MTTG_TRAV_NFP_SPEC:
|
trav->curr = trav->curr->next;
|
if (trav->curr != trav->head)
|
break;
|
fallthrough;
|
default:
|
return NULL;
|
}
|
return trav;
|
}
|
|
static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos,
|
bool is_target)
|
{
|
struct nf_mttg_trav *trav = seq->private;
|
unsigned int j;
|
|
trav->class = MTTG_TRAV_INIT;
|
for (j = 0; j < *pos; ++j)
|
if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL)
|
return NULL;
|
return trav;
|
}
|
|
static void xt_mttg_seq_stop(struct seq_file *seq, void *v)
|
{
|
uint8_t nfproto = (unsigned long)PDE_DATA(file_inode(seq->file));
|
struct nf_mttg_trav *trav = seq->private;
|
|
switch (trav->class) {
|
case MTTG_TRAV_NFP_UNSPEC:
|
mutex_unlock(&xt[NFPROTO_UNSPEC].mutex);
|
break;
|
case MTTG_TRAV_NFP_SPEC:
|
mutex_unlock(&xt[nfproto].mutex);
|
break;
|
}
|
}
|
|
static void *xt_match_seq_start(struct seq_file *seq, loff_t *pos)
|
{
|
return xt_mttg_seq_start(seq, pos, false);
|
}
|
|
static void *xt_match_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
|
{
|
return xt_mttg_seq_next(seq, v, ppos, false);
|
}
|
|
static int xt_match_seq_show(struct seq_file *seq, void *v)
|
{
|
const struct nf_mttg_trav *trav = seq->private;
|
const struct xt_match *match;
|
|
switch (trav->class) {
|
case MTTG_TRAV_NFP_UNSPEC:
|
case MTTG_TRAV_NFP_SPEC:
|
if (trav->curr == trav->head)
|
return 0;
|
match = list_entry(trav->curr, struct xt_match, list);
|
if (*match->name)
|
seq_printf(seq, "%s\n", match->name);
|
}
|
return 0;
|
}
|
|
static const struct seq_operations xt_match_seq_ops = {
|
.start = xt_match_seq_start,
|
.next = xt_match_seq_next,
|
.stop = xt_mttg_seq_stop,
|
.show = xt_match_seq_show,
|
};
|
|
static void *xt_target_seq_start(struct seq_file *seq, loff_t *pos)
|
{
|
return xt_mttg_seq_start(seq, pos, true);
|
}
|
|
static void *xt_target_seq_next(struct seq_file *seq, void *v, loff_t *ppos)
|
{
|
return xt_mttg_seq_next(seq, v, ppos, true);
|
}
|
|
static int xt_target_seq_show(struct seq_file *seq, void *v)
|
{
|
const struct nf_mttg_trav *trav = seq->private;
|
const struct xt_target *target;
|
|
switch (trav->class) {
|
case MTTG_TRAV_NFP_UNSPEC:
|
case MTTG_TRAV_NFP_SPEC:
|
if (trav->curr == trav->head)
|
return 0;
|
target = list_entry(trav->curr, struct xt_target, list);
|
if (*target->name)
|
seq_printf(seq, "%s\n", target->name);
|
}
|
return 0;
|
}
|
|
static const struct seq_operations xt_target_seq_ops = {
|
.start = xt_target_seq_start,
|
.next = xt_target_seq_next,
|
.stop = xt_mttg_seq_stop,
|
.show = xt_target_seq_show,
|
};
|
|
#define FORMAT_TABLES "_tables_names"
|
#define FORMAT_MATCHES "_tables_matches"
|
#define FORMAT_TARGETS "_tables_targets"
|
|
#endif /* CONFIG_PROC_FS */
|
|
/**
|
* xt_hook_ops_alloc - set up hooks for a new table
|
* @table: table with metadata needed to set up hooks
|
* @fn: Hook function
|
*
|
* This function will create the nf_hook_ops that the x_table needs
|
* to hand to xt_hook_link_net().
|
*/
|
struct nf_hook_ops *
|
xt_hook_ops_alloc(const struct xt_table *table, nf_hookfn *fn)
|
{
|
unsigned int hook_mask = table->valid_hooks;
|
uint8_t i, num_hooks = hweight32(hook_mask);
|
uint8_t hooknum;
|
struct nf_hook_ops *ops;
|
|
if (!num_hooks)
|
return ERR_PTR(-EINVAL);
|
|
ops = kcalloc(num_hooks, sizeof(*ops), GFP_KERNEL);
|
if (ops == NULL)
|
return ERR_PTR(-ENOMEM);
|
|
for (i = 0, hooknum = 0; i < num_hooks && hook_mask != 0;
|
hook_mask >>= 1, ++hooknum) {
|
if (!(hook_mask & 1))
|
continue;
|
ops[i].hook = fn;
|
ops[i].pf = table->af;
|
ops[i].hooknum = hooknum;
|
ops[i].priority = table->priority;
|
++i;
|
}
|
|
return ops;
|
}
|
EXPORT_SYMBOL_GPL(xt_hook_ops_alloc);
|
|
int xt_proto_init(struct net *net, u_int8_t af)
|
{
|
#ifdef CONFIG_PROC_FS
|
char buf[XT_FUNCTION_MAXNAMELEN];
|
struct proc_dir_entry *proc;
|
kuid_t root_uid;
|
kgid_t root_gid;
|
#endif
|
|
if (af >= ARRAY_SIZE(xt_prefix))
|
return -EINVAL;
|
|
|
#ifdef CONFIG_PROC_FS
|
root_uid = make_kuid(net->user_ns, 0);
|
root_gid = make_kgid(net->user_ns, 0);
|
|
strlcpy(buf, xt_prefix[af], sizeof(buf));
|
strlcat(buf, FORMAT_TABLES, sizeof(buf));
|
proc = proc_create_net_data(buf, 0440, net->proc_net, &xt_table_seq_ops,
|
sizeof(struct seq_net_private),
|
(void *)(unsigned long)af);
|
if (!proc)
|
goto out;
|
if (uid_valid(root_uid) && gid_valid(root_gid))
|
proc_set_user(proc, root_uid, root_gid);
|
|
strlcpy(buf, xt_prefix[af], sizeof(buf));
|
strlcat(buf, FORMAT_MATCHES, sizeof(buf));
|
proc = proc_create_seq_private(buf, 0440, net->proc_net,
|
&xt_match_seq_ops, sizeof(struct nf_mttg_trav),
|
(void *)(unsigned long)af);
|
if (!proc)
|
goto out_remove_tables;
|
if (uid_valid(root_uid) && gid_valid(root_gid))
|
proc_set_user(proc, root_uid, root_gid);
|
|
strlcpy(buf, xt_prefix[af], sizeof(buf));
|
strlcat(buf, FORMAT_TARGETS, sizeof(buf));
|
proc = proc_create_seq_private(buf, 0440, net->proc_net,
|
&xt_target_seq_ops, sizeof(struct nf_mttg_trav),
|
(void *)(unsigned long)af);
|
if (!proc)
|
goto out_remove_matches;
|
if (uid_valid(root_uid) && gid_valid(root_gid))
|
proc_set_user(proc, root_uid, root_gid);
|
#endif
|
|
return 0;
|
|
#ifdef CONFIG_PROC_FS
|
out_remove_matches:
|
strlcpy(buf, xt_prefix[af], sizeof(buf));
|
strlcat(buf, FORMAT_MATCHES, sizeof(buf));
|
remove_proc_entry(buf, net->proc_net);
|
|
out_remove_tables:
|
strlcpy(buf, xt_prefix[af], sizeof(buf));
|
strlcat(buf, FORMAT_TABLES, sizeof(buf));
|
remove_proc_entry(buf, net->proc_net);
|
out:
|
return -1;
|
#endif
|
}
|
EXPORT_SYMBOL_GPL(xt_proto_init);
|
|
void xt_proto_fini(struct net *net, u_int8_t af)
|
{
|
#ifdef CONFIG_PROC_FS
|
char buf[XT_FUNCTION_MAXNAMELEN];
|
|
strlcpy(buf, xt_prefix[af], sizeof(buf));
|
strlcat(buf, FORMAT_TABLES, sizeof(buf));
|
remove_proc_entry(buf, net->proc_net);
|
|
strlcpy(buf, xt_prefix[af], sizeof(buf));
|
strlcat(buf, FORMAT_TARGETS, sizeof(buf));
|
remove_proc_entry(buf, net->proc_net);
|
|
strlcpy(buf, xt_prefix[af], sizeof(buf));
|
strlcat(buf, FORMAT_MATCHES, sizeof(buf));
|
remove_proc_entry(buf, net->proc_net);
|
#endif /*CONFIG_PROC_FS*/
|
}
|
EXPORT_SYMBOL_GPL(xt_proto_fini);
|
|
/**
|
* xt_percpu_counter_alloc - allocate x_tables rule counter
|
*
|
* @state: pointer to xt_percpu allocation state
|
* @counter: pointer to counter struct inside the ip(6)/arpt_entry struct
|
*
|
* On SMP, the packet counter [ ip(6)t_entry->counters.pcnt ] will then
|
* contain the address of the real (percpu) counter.
|
*
|
* Rule evaluation needs to use xt_get_this_cpu_counter() helper
|
* to fetch the real percpu counter.
|
*
|
* To speed up allocation and improve data locality, a 4kb block is
|
* allocated. Freeing any counter may free an entire block, so all
|
* counters allocated using the same state must be freed at the same
|
* time.
|
*
|
* xt_percpu_counter_alloc_state contains the base address of the
|
* allocated page and the current sub-offset.
|
*
|
* returns false on error.
|
*/
|
bool xt_percpu_counter_alloc(struct xt_percpu_counter_alloc_state *state,
|
struct xt_counters *counter)
|
{
|
BUILD_BUG_ON(XT_PCPU_BLOCK_SIZE < (sizeof(*counter) * 2));
|
|
if (nr_cpu_ids <= 1)
|
return true;
|
|
if (!state->mem) {
|
state->mem = __alloc_percpu(XT_PCPU_BLOCK_SIZE,
|
XT_PCPU_BLOCK_SIZE);
|
if (!state->mem)
|
return false;
|
}
|
counter->pcnt = (__force unsigned long)(state->mem + state->off);
|
state->off += sizeof(*counter);
|
if (state->off > (XT_PCPU_BLOCK_SIZE - sizeof(*counter))) {
|
state->mem = NULL;
|
state->off = 0;
|
}
|
return true;
|
}
|
EXPORT_SYMBOL_GPL(xt_percpu_counter_alloc);
|
|
void xt_percpu_counter_free(struct xt_counters *counters)
|
{
|
unsigned long pcnt = counters->pcnt;
|
|
if (nr_cpu_ids > 1 && (pcnt & (XT_PCPU_BLOCK_SIZE - 1)) == 0)
|
free_percpu((void __percpu *)pcnt);
|
}
|
EXPORT_SYMBOL_GPL(xt_percpu_counter_free);
|
|
static int __net_init xt_net_init(struct net *net)
|
{
|
int i;
|
|
for (i = 0; i < NFPROTO_NUMPROTO; i++)
|
INIT_LIST_HEAD(&net->xt.tables[i]);
|
return 0;
|
}
|
|
static void __net_exit xt_net_exit(struct net *net)
|
{
|
int i;
|
|
for (i = 0; i < NFPROTO_NUMPROTO; i++)
|
WARN_ON_ONCE(!list_empty(&net->xt.tables[i]));
|
}
|
|
static struct pernet_operations xt_net_ops = {
|
.init = xt_net_init,
|
.exit = xt_net_exit,
|
};
|
|
static int __init xt_init(void)
|
{
|
unsigned int i;
|
int rv;
|
|
for_each_possible_cpu(i) {
|
seqcount_init(&per_cpu(xt_recseq, i));
|
}
|
|
xt = kcalloc(NFPROTO_NUMPROTO, sizeof(struct xt_af), GFP_KERNEL);
|
if (!xt)
|
return -ENOMEM;
|
|
for (i = 0; i < NFPROTO_NUMPROTO; i++) {
|
mutex_init(&xt[i].mutex);
|
#ifdef CONFIG_COMPAT
|
mutex_init(&xt[i].compat_mutex);
|
xt[i].compat_tab = NULL;
|
#endif
|
INIT_LIST_HEAD(&xt[i].target);
|
INIT_LIST_HEAD(&xt[i].match);
|
}
|
rv = register_pernet_subsys(&xt_net_ops);
|
if (rv < 0)
|
kfree(xt);
|
return rv;
|
}
|
|
static void __exit xt_fini(void)
|
{
|
unregister_pernet_subsys(&xt_net_ops);
|
kfree(xt);
|
}
|
|
module_init(xt_init);
|
module_exit(xt_fini);
|
