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path: root/net/ipv4/netfilter/arp_tables.c
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Diffstat (limited to 'net/ipv4/netfilter/arp_tables.c')
-rw-r--r--net/ipv4/netfilter/arp_tables.c109
1 files changed, 64 insertions, 45 deletions
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index b488cac9c..4133b0f51 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -359,11 +359,12 @@ unsigned int arpt_do_table(struct sk_buff *skb,
}
/* All zeroes == unconditional rule. */
-static inline bool unconditional(const struct arpt_arp *arp)
+static inline bool unconditional(const struct arpt_entry *e)
{
static const struct arpt_arp uncond;
- return memcmp(arp, &uncond, sizeof(uncond)) == 0;
+ return e->target_offset == sizeof(struct arpt_entry) &&
+ memcmp(&e->arp, &uncond, sizeof(uncond)) == 0;
}
/* Figures out from what hook each rule can be called: returns 0 if
@@ -402,11 +403,10 @@ static int mark_source_chains(const struct xt_table_info *newinfo,
|= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
/* Unconditional return/END. */
- if ((e->target_offset == sizeof(struct arpt_entry) &&
+ if ((unconditional(e) &&
(strcmp(t->target.u.user.name,
XT_STANDARD_TARGET) == 0) &&
- t->verdict < 0 && unconditional(&e->arp)) ||
- visited) {
+ t->verdict < 0) || visited) {
unsigned int oldpos, size;
if ((strcmp(t->target.u.user.name,
@@ -474,14 +474,12 @@ next:
return 1;
}
-static inline int check_entry(const struct arpt_entry *e, const char *name)
+static inline int check_entry(const struct arpt_entry *e)
{
const struct xt_entry_target *t;
- if (!arp_checkentry(&e->arp)) {
- duprintf("arp_tables: arp check failed %p %s.\n", e, name);
+ if (!arp_checkentry(&e->arp))
return -EINVAL;
- }
if (e->target_offset + sizeof(struct xt_entry_target) > e->next_offset)
return -EINVAL;
@@ -522,10 +520,6 @@ find_check_entry(struct arpt_entry *e, const char *name, unsigned int size)
struct xt_target *target;
int ret;
- ret = check_entry(e, name);
- if (ret)
- return ret;
-
e->counters.pcnt = xt_percpu_counter_alloc();
if (IS_ERR_VALUE(e->counters.pcnt))
return -ENOMEM;
@@ -557,7 +551,7 @@ static bool check_underflow(const struct arpt_entry *e)
const struct xt_entry_target *t;
unsigned int verdict;
- if (!unconditional(&e->arp))
+ if (!unconditional(e))
return false;
t = arpt_get_target_c(e);
if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
@@ -576,9 +570,11 @@ static inline int check_entry_size_and_hooks(struct arpt_entry *e,
unsigned int valid_hooks)
{
unsigned int h;
+ int err;
if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 ||
- (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
+ (unsigned char *)e + sizeof(struct arpt_entry) >= limit ||
+ (unsigned char *)e + e->next_offset > limit) {
duprintf("Bad offset %p\n", e);
return -EINVAL;
}
@@ -590,6 +586,10 @@ static inline int check_entry_size_and_hooks(struct arpt_entry *e,
return -EINVAL;
}
+ err = check_entry(e);
+ if (err)
+ return err;
+
/* Check hooks & underflows */
for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
if (!(valid_hooks & (1 << h)))
@@ -598,9 +598,9 @@ static inline int check_entry_size_and_hooks(struct arpt_entry *e,
newinfo->hook_entry[h] = hook_entries[h];
if ((unsigned char *)e - base == underflows[h]) {
if (!check_underflow(e)) {
- pr_err("Underflows must be unconditional and "
- "use the STANDARD target with "
- "ACCEPT/DROP\n");
+ pr_debug("Underflows must be unconditional and "
+ "use the STANDARD target with "
+ "ACCEPT/DROP\n");
return -EINVAL;
}
newinfo->underflow[h] = underflows[h];
@@ -969,6 +969,7 @@ static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
sizeof(struct arpt_get_entries) + get.size);
return -EINVAL;
}
+ get.name[sizeof(get.name) - 1] = '\0';
t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
if (!IS_ERR_OR_NULL(t)) {
@@ -1233,7 +1234,8 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
duprintf("check_compat_entry_size_and_hooks %p\n", e);
if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 ||
- (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
+ (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit ||
+ (unsigned char *)e + e->next_offset > limit) {
duprintf("Bad offset %p, limit = %p\n", e, limit);
return -EINVAL;
}
@@ -1246,7 +1248,7 @@ check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
}
/* For purposes of check_entry casting the compat entry is fine */
- ret = check_entry((struct arpt_entry *)e, name);
+ ret = check_entry((struct arpt_entry *)e);
if (ret)
return ret;
@@ -1662,6 +1664,7 @@ static int compat_get_entries(struct net *net,
*len, sizeof(get) + get.size);
return -EINVAL;
}
+ get.name[sizeof(get.name) - 1] = '\0';
xt_compat_lock(NFPROTO_ARP);
t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
@@ -1780,9 +1783,29 @@ static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len
return ret;
}
-struct xt_table *arpt_register_table(struct net *net,
- const struct xt_table *table,
- const struct arpt_replace *repl)
+static void __arpt_unregister_table(struct xt_table *table)
+{
+ struct xt_table_info *private;
+ void *loc_cpu_entry;
+ struct module *table_owner = table->me;
+ struct arpt_entry *iter;
+
+ private = xt_unregister_table(table);
+
+ /* Decrease module usage counts and free resources */
+ loc_cpu_entry = private->entries;
+ xt_entry_foreach(iter, loc_cpu_entry, private->size)
+ cleanup_entry(iter);
+ if (private->number > private->initial_entries)
+ module_put(table_owner);
+ xt_free_table_info(private);
+}
+
+int arpt_register_table(struct net *net,
+ const struct xt_table *table,
+ const struct arpt_replace *repl,
+ const struct nf_hook_ops *ops,
+ struct xt_table **res)
{
int ret;
struct xt_table_info *newinfo;
@@ -1791,10 +1814,8 @@ struct xt_table *arpt_register_table(struct net *net,
struct xt_table *new_table;
newinfo = xt_alloc_table_info(repl->size);
- if (!newinfo) {
- ret = -ENOMEM;
- goto out;
- }
+ if (!newinfo)
+ return -ENOMEM;
loc_cpu_entry = newinfo->entries;
memcpy(loc_cpu_entry, repl->entries, repl->size);
@@ -1809,30 +1830,28 @@ struct xt_table *arpt_register_table(struct net *net,
ret = PTR_ERR(new_table);
goto out_free;
}
- return new_table;
+
+ /* set res now, will see skbs right after nf_register_net_hooks */
+ WRITE_ONCE(*res, new_table);
+
+ ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks));
+ if (ret != 0) {
+ __arpt_unregister_table(new_table);
+ *res = NULL;
+ }
+
+ return ret;
out_free:
xt_free_table_info(newinfo);
-out:
- return ERR_PTR(ret);
+ return ret;
}
-void arpt_unregister_table(struct xt_table *table)
+void arpt_unregister_table(struct net *net, struct xt_table *table,
+ const struct nf_hook_ops *ops)
{
- struct xt_table_info *private;
- void *loc_cpu_entry;
- struct module *table_owner = table->me;
- struct arpt_entry *iter;
-
- private = xt_unregister_table(table);
-
- /* Decrease module usage counts and free resources */
- loc_cpu_entry = private->entries;
- xt_entry_foreach(iter, loc_cpu_entry, private->size)
- cleanup_entry(iter);
- if (private->number > private->initial_entries)
- module_put(table_owner);
- xt_free_table_info(private);
+ nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
+ __arpt_unregister_table(table);
}
/* The built-in targets: standard (NULL) and error. */
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-01 10:36:03 +0000