* published by the Free Software Foundation.
*
*/
-
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/socket.h>
#include <linux/net.h>
#include <linux/vmalloc.h>
#include <linux/mutex.h>
#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/audit.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>");
#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
struct compat_delta {
- struct compat_delta *next;
- unsigned int offset;
- short delta;
+ unsigned int offset; /* offset in kernel */
+ int delta; /* delta in 32bit user land */
};
struct xt_af {
struct list_head target;
#ifdef CONFIG_COMPAT
struct mutex compat_mutex;
- struct compat_delta *compat_offsets;
+ 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;
-#ifdef DEBUG_IP_FIREWALL_USER
-#define duprintf(format, args...) printk(format , ## args)
-#else
-#define duprintf(format, args...)
-#endif
-
static const char *const xt_prefix[NFPROTO_NUMPROTO] = {
[NFPROTO_UNSPEC] = "x",
[NFPROTO_IPV4] = "ip",
[NFPROTO_IPV6] = "ip6",
};
+/* Allow this many total (re)entries. */
+static const unsigned int xt_jumpstack_multiplier = 2;
+
/* Registration hooks for targets. */
int
xt_register_target(struct xt_target *target)
void
xt_unregister_targets(struct xt_target *target, unsigned int n)
{
- unsigned int i;
-
- for (i = 0; i < n; i++)
- xt_unregister_target(&target[i]);
+ while (n-- > 0)
+ xt_unregister_target(&target[n]);
}
EXPORT_SYMBOL(xt_unregister_targets);
void
xt_unregister_matches(struct xt_match *match, unsigned int n)
{
- unsigned int i;
-
- for (i = 0; i < n; i++)
- xt_unregister_match(&match[i]);
+ while (n-- > 0)
+ xt_unregister_match(&match[n]);
}
EXPORT_SYMBOL(xt_unregister_matches);
}
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;
+
+ match = try_then_request_module(xt_find_match(nfproto, name, revision),
+ "%st_%s", xt_prefix[nfproto], name);
+ return (match != NULL) ? match : ERR_PTR(-ENOENT);
+}
+EXPORT_SYMBOL_GPL(xt_request_find_match);
+
/* Find target, grabs ref. Returns ERR_PTR() on error. */
struct xt_target *xt_find_target(u8 af, const char *name, u8 revision)
{
target = try_then_request_module(xt_find_target(af, name, revision),
"%st_%s", xt_prefix[af], name);
- if (IS_ERR(target) || !target)
- return NULL;
- return target;
+ return (target != NULL) ? target : ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL_GPL(xt_request_find_target);
int xt_check_match(struct xt_mtchk_param *par,
unsigned int size, u_int8_t 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("%s_tables: %s match: invalid size %Zu != %u\n",
+ pr_err("%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;
}
par->match->proto);
return -EINVAL;
}
- if (par->match->checkentry != NULL && !par->match->checkentry(par))
- 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);
#ifdef CONFIG_COMPAT
-int xt_compat_add_offset(u_int8_t af, unsigned int offset, short delta)
+int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta)
{
- struct compat_delta *tmp;
-
- tmp = kmalloc(sizeof(struct compat_delta), GFP_KERNEL);
- if (!tmp)
- return -ENOMEM;
+ struct xt_af *xp = &xt[af];
+
+ if (!xp->compat_tab) {
+ if (!xp->number)
+ return -EINVAL;
+ xp->compat_tab = vmalloc(sizeof(struct compat_delta) * xp->number);
+ if (!xp->compat_tab)
+ return -ENOMEM;
+ xp->cur = 0;
+ }
- tmp->offset = offset;
- tmp->delta = delta;
+ if (xp->cur >= xp->number)
+ return -EINVAL;
- if (xt[af].compat_offsets) {
- tmp->next = xt[af].compat_offsets->next;
- xt[af].compat_offsets->next = tmp;
- } else {
- xt[af].compat_offsets = tmp;
- tmp->next = NULL;
- }
+ 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)
{
- struct compat_delta *tmp, *next;
-
- if (xt[af].compat_offsets) {
- for (tmp = xt[af].compat_offsets; tmp; tmp = next) {
- next = tmp->next;
- kfree(tmp);
- }
- xt[af].compat_offsets = NULL;
+ if (xt[af].compat_tab) {
+ vfree(xt[af].compat_tab);
+ xt[af].compat_tab = NULL;
+ xt[af].number = 0;
}
}
EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);
-short xt_compat_calc_jump(u_int8_t af, unsigned int offset)
+int xt_compat_calc_jump(u_int8_t af, unsigned int offset)
{
- struct compat_delta *tmp;
- short delta;
-
- for (tmp = xt[af].compat_offsets, delta = 0; tmp; tmp = tmp->next)
- if (tmp->offset < offset)
- delta += tmp->delta;
- return delta;
+ 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;
+ }
+ WARN_ON_ONCE(1);
+ return 0;
}
EXPORT_SYMBOL_GPL(xt_compat_calc_jump);
+void xt_compat_init_offsets(u_int8_t af, unsigned int number)
+{
+ xt[af].number = number;
+ xt[af].cur = 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;
}
EXPORT_SYMBOL_GPL(xt_compat_match_from_user);
-int xt_compat_match_to_user(struct xt_entry_match *m, void __user **dstptr,
- unsigned int *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 xt_check_target(struct xt_tgchk_param *par,
unsigned int size, u_int8_t proto, bool inv_proto)
{
+ int ret;
+
if (XT_ALIGN(par->target->targetsize) != size) {
- pr_err("%s_tables: %s target: invalid size %Zu != %u\n",
+ pr_err("%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;
}
par->target->proto);
return -EINVAL;
}
- if (par->target->checkentry != NULL && !par->target->checkentry(par))
- 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);
}
EXPORT_SYMBOL_GPL(xt_compat_target_from_user);
-int xt_compat_target_to_user(struct xt_entry_target *t, void __user **dstptr,
- unsigned int *size)
+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 cpu;
/* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
- if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > num_physpages)
+ if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages)
return NULL;
newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL);
else
vfree(info->entries[cpu]);
}
+
+ if (info->jumpstack != NULL) {
+ if (sizeof(void *) * info->stacksize > PAGE_SIZE) {
+ for_each_possible_cpu(cpu)
+ vfree(info->jumpstack[cpu]);
+ } else {
+ for_each_possible_cpu(cpu)
+ kfree(info->jumpstack[cpu]);
+ }
+ }
+
+ if (sizeof(void **) * nr_cpu_ids > PAGE_SIZE)
+ vfree(info->jumpstack);
+ else
+ kfree(info->jumpstack);
+
+ free_percpu(info->stackptr);
+
kfree(info);
}
EXPORT_SYMBOL(xt_free_table_info);
DEFINE_PER_CPU(struct xt_info_lock, xt_info_locks);
EXPORT_PER_CPU_SYMBOL_GPL(xt_info_locks);
+static int xt_jumpstack_alloc(struct xt_table_info *i)
+{
+ unsigned int size;
+ int cpu;
+
+ i->stackptr = alloc_percpu(unsigned int);
+ if (i->stackptr == NULL)
+ return -ENOMEM;
+
+ size = sizeof(void **) * nr_cpu_ids;
+ if (size > PAGE_SIZE)
+ i->jumpstack = vmalloc(size);
+ else
+ i->jumpstack = kmalloc(size, GFP_KERNEL);
+ if (i->jumpstack == NULL)
+ return -ENOMEM;
+ memset(i->jumpstack, 0, size);
+
+ i->stacksize *= xt_jumpstack_multiplier;
+ size = sizeof(void *) * i->stacksize;
+ for_each_possible_cpu(cpu) {
+ if (size > PAGE_SIZE)
+ i->jumpstack[cpu] = vmalloc_node(size,
+ cpu_to_node(cpu));
+ else
+ i->jumpstack[cpu] = kmalloc_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_table_info *
xt_replace_table(struct xt_table *table,
int *error)
{
struct xt_table_info *private;
+ int ret;
+
+ ret = xt_jumpstack_alloc(newinfo);
+ if (ret < 0) {
+ *error = ret;
+ return NULL;
+ }
/* Do the substitution. */
local_bh_disable();
/* Check inside lock: is the old number correct? */
if (num_counters != private->number) {
- duprintf("num_counters != table->private->number (%u/%u)\n",
+ pr_debug("num_counters != table->private->number (%u/%u)\n",
num_counters, private->number);
local_bh_enable();
*error = -EAGAIN;
*/
local_bh_enable();
+#ifdef CONFIG_AUDIT
+ if (audit_enabled) {
+ struct audit_buffer *ab;
+
+ ab = audit_log_start(current->audit_context, GFP_KERNEL,
+ AUDIT_NETFILTER_CFG);
+ if (ab) {
+ audit_log_format(ab, "table=%s family=%u entries=%u",
+ table->name, table->af,
+ private->number);
+ audit_log_end(ab);
+ }
+ }
+#endif
+
return private;
}
EXPORT_SYMBOL_GPL(xt_replace_table);
-struct xt_table *xt_register_table(struct net *net, struct xt_table *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;
+ struct xt_table *t, *table;
/* Don't add one object to multiple lists. */
- table = kmemdup(table, sizeof(struct xt_table), GFP_KERNEL);
+ table = kmemdup(input_table, sizeof(struct xt_table), GFP_KERNEL);
if (!table) {
ret = -ENOMEM;
goto out;
goto unlock;
private = table->private;
- duprintf("table->private->number = %u\n", private->number);
+ pr_debug("table->private->number = %u\n", private->number);
/* save number of initial entries */
private->initial_entries = private->number;
#endif /* CONFIG_PROC_FS */
+/**
+ * xt_hook_link - set up hooks for a new table
+ * @table: table with metadata needed to set up hooks
+ * @fn: Hook function
+ *
+ * This function will take care of creating and registering the necessary
+ * Netfilter hooks for XT tables.
+ */
+struct nf_hook_ops *xt_hook_link(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;
+ int ret;
+
+ ops = kmalloc(sizeof(*ops) * num_hooks, 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].owner = table->me;
+ ops[i].pf = table->af;
+ ops[i].hooknum = hooknum;
+ ops[i].priority = table->priority;
+ ++i;
+ }
+
+ ret = nf_register_hooks(ops, num_hooks);
+ if (ret < 0) {
+ kfree(ops);
+ return ERR_PTR(ret);
+ }
+
+ return ops;
+}
+EXPORT_SYMBOL_GPL(xt_hook_link);
+
+/**
+ * xt_hook_unlink - remove hooks for a table
+ * @ops: nf_hook_ops array as returned by nf_hook_link
+ * @hook_mask: the very same mask that was passed to nf_hook_link
+ */
+void xt_hook_unlink(const struct xt_table *table, struct nf_hook_ops *ops)
+{
+ nf_unregister_hooks(ops, hweight32(table->valid_hooks));
+ kfree(ops);
+}
+EXPORT_SYMBOL_GPL(xt_hook_unlink);
+
int xt_proto_init(struct net *net, u_int8_t af)
{
#ifdef CONFIG_PROC_FS
for_each_possible_cpu(i) {
struct xt_info_lock *lock = &per_cpu(xt_info_locks, i);
- spin_lock_init(&lock->lock);
+
+ seqlock_init(&lock->lock);
lock->readers = 0;
}
mutex_init(&xt[i].mutex);
#ifdef CONFIG_COMPAT
mutex_init(&xt[i].compat_mutex);
- xt[i].compat_offsets = NULL;
+ xt[i].compat_tab = NULL;
#endif
INIT_LIST_HEAD(&xt[i].target);
INIT_LIST_HEAD(&xt[i].match);