aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorPatrick McHardy <kaber@trash.net>2006-03-20 17:59:06 -0800
committerDavid S. Miller <davem@davemloft.net>2006-03-20 17:59:06 -0800
commit37f9f7334b86ffc3b8a1921842ae33cb9aa22ee3 (patch)
treed207ae0a0f2eb37072dd4690de95b6cf170e4e04
parent[NETFILTER]: nf_conntrack: use ipv6_addr_equal in nf_ct_reasm (diff)
downloadlinux-dev-37f9f7334b86ffc3b8a1921842ae33cb9aa22ee3.tar.xz
linux-dev-37f9f7334b86ffc3b8a1921842ae33cb9aa22ee3.zip
[NETFILTER]: xt_tables: add centralized error checking
Introduce new functions for common match/target checks (private data size, valid hooks, valid tables and valid protocols) to get more consistent error reporting and to avoid each module duplicating them. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/linux/netfilter/x_tables.h23
-rw-r--r--net/netfilter/x_tables.c72
2 files changed, 84 insertions, 11 deletions
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index 6500d4e59d46..b9c37e1e6730 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -92,8 +92,6 @@ struct xt_match
const char name[XT_FUNCTION_MAXNAMELEN-1];
- u_int8_t revision;
-
/* Return true or false: return FALSE and set *hotdrop = 1 to
force immediate packet drop. */
/* Arguments changed since 2.6.9, as this must now handle
@@ -120,6 +118,12 @@ struct xt_match
/* Set this to THIS_MODULE if you are a module, otherwise NULL */
struct module *me;
+
+ char *table;
+ unsigned int matchsize;
+ unsigned int hooks;
+ unsigned short proto;
+ u_int8_t revision;
};
/* Registration hooks for targets. */
@@ -129,8 +133,6 @@ struct xt_target
const char name[XT_FUNCTION_MAXNAMELEN-1];
- u_int8_t revision;
-
/* Returns verdict. Argument order changed since 2.6.9, as this
must now handle non-linear skbs, using skb_copy_bits and
skb_ip_make_writable. */
@@ -156,6 +158,12 @@ struct xt_target
/* Set this to THIS_MODULE if you are a module, otherwise NULL */
struct module *me;
+
+ char *table;
+ unsigned int targetsize;
+ unsigned int hooks;
+ unsigned short proto;
+ u_int8_t revision;
};
/* Furniture shopping... */
@@ -207,6 +215,13 @@ extern void xt_unregister_target(int af, struct xt_target *target);
extern int xt_register_match(int af, struct xt_match *target);
extern void xt_unregister_match(int af, struct xt_match *target);
+extern int xt_check_match(const struct xt_match *match, unsigned short family,
+ unsigned int size, const char *table, unsigned int hook,
+ unsigned short proto, int inv_proto);
+extern int xt_check_target(const struct xt_target *target, unsigned short family,
+ unsigned int size, const char *table, unsigned int hook,
+ unsigned short proto, int inv_proto);
+
extern int xt_register_table(struct xt_table *table,
struct xt_table_info *bootstrap,
struct xt_table_info *newinfo);
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index d7817afc6b96..750b92829766 100644
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -52,6 +52,12 @@ enum {
MATCH,
};
+static const char *xt_prefix[NPROTO] = {
+ [AF_INET] = "ip",
+ [AF_INET6] = "ip6",
+ [NF_ARP] = "arp",
+};
+
/* Registration hooks for targets. */
int
xt_register_target(int af, struct xt_target *target)
@@ -158,18 +164,12 @@ struct xt_target *xt_find_target(int af, const char *name, u8 revision)
}
EXPORT_SYMBOL(xt_find_target);
-static const char *xt_prefix[NPROTO] = {
- [AF_INET] = "ipt_%s",
- [AF_INET6] = "ip6t_%s",
- [NF_ARP] = "arpt_%s",
-};
-
struct xt_target *xt_request_find_target(int af, const char *name, u8 revision)
{
struct xt_target *target;
target = try_then_request_module(xt_find_target(af, name, revision),
- xt_prefix[af], name);
+ "%st_%s", xt_prefix[af], name);
if (IS_ERR(target) || !target)
return NULL;
return target;
@@ -237,6 +237,64 @@ int xt_find_revision(int af, const char *name, u8 revision, int target,
}
EXPORT_SYMBOL_GPL(xt_find_revision);
+int xt_check_match(const struct xt_match *match, unsigned short family,
+ unsigned int size, const char *table, unsigned int hook_mask,
+ unsigned short proto, int inv_proto)
+{
+ if (XT_ALIGN(match->matchsize) != size) {
+ printk("%s_tables: %s match: invalid size %Zu != %u\n",
+ xt_prefix[family], match->name,
+ XT_ALIGN(match->matchsize), size);
+ return -EINVAL;
+ }
+ if (match->table && strcmp(match->table, table)) {
+ printk("%s_tables: %s match: only valid in %s table, not %s\n",
+ xt_prefix[family], match->name, match->table, table);
+ return -EINVAL;
+ }
+ if (match->hooks && (hook_mask & ~match->hooks) != 0) {
+ printk("%s_tables: %s match: bad hook_mask %u\n",
+ xt_prefix[family], match->name, hook_mask);
+ return -EINVAL;
+ }
+ if (match->proto && (match->proto != proto || inv_proto)) {
+ printk("%s_tables: %s match: only valid for protocol %u\n",
+ xt_prefix[family], match->name, match->proto);
+ return -EINVAL;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xt_check_match);
+
+int xt_check_target(const struct xt_target *target, unsigned short family,
+ unsigned int size, const char *table, unsigned int hook_mask,
+ unsigned short proto, int inv_proto)
+{
+ if (XT_ALIGN(target->targetsize) != size) {
+ printk("%s_tables: %s target: invalid size %Zu != %u\n",
+ xt_prefix[family], target->name,
+ XT_ALIGN(target->targetsize), size);
+ return -EINVAL;
+ }
+ if (target->table && strcmp(target->table, table)) {
+ printk("%s_tables: %s target: only valid in %s table, not %s\n",
+ xt_prefix[family], target->name, target->table, table);
+ return -EINVAL;
+ }
+ if (target->hooks && (hook_mask & ~target->hooks) != 0) {
+ printk("%s_tables: %s target: bad hook_mask %u\n",
+ xt_prefix[family], target->name, hook_mask);
+ return -EINVAL;
+ }
+ if (target->proto && (target->proto != proto || inv_proto)) {
+ printk("%s_tables: %s target: only valid for protocol %u\n",
+ xt_prefix[family], target->name, target->proto);
+ return -EINVAL;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xt_check_target);
+
struct xt_table_info *xt_alloc_table_info(unsigned int size)
{
struct xt_table_info *newinfo;