[NETFILTER]: nf_conntrack: automatic sysctl registation for conntrack protocols
Add helper functions for sysctl registration with optional instantiating
of common path elements (like net/netfilter) and use it for support for
automatic registation of conntrack protocol sysctls.
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 6ab5e2d..f6f3fcb 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -117,6 +117,16 @@
int nf_register_sockopt(struct nf_sockopt_ops *reg);
void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
+#ifdef CONFIG_SYSCTL
+/* Sysctl registration */
+struct ctl_table_header *nf_register_sysctl_table(struct ctl_table *path,
+ struct ctl_table *table);
+void nf_unregister_sysctl_table(struct ctl_table_header *header,
+ struct ctl_table *table);
+extern struct ctl_table nf_net_netfilter_sysctl_path[];
+extern struct ctl_table nf_net_ipv4_netfilter_sysctl_path[];
+#endif /* CONFIG_SYSCTL */
+
extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS];
/* those NF_LOG_* defines and struct nf_loginfo are legacy definitios that will
diff --git a/include/net/netfilter/nf_conntrack_l3proto.h b/include/net/netfilter/nf_conntrack_l3proto.h
index 6364df0..664ddcf 100644
--- a/include/net/netfilter/nf_conntrack_l3proto.h
+++ b/include/net/netfilter/nf_conntrack_l3proto.h
@@ -75,6 +75,12 @@
int (*nfattr_to_tuple)(struct nfattr *tb[],
struct nf_conntrack_tuple *t);
+#ifdef CONFIG_SYSCTL
+ struct ctl_table_header *ctl_table_header;
+ struct ctl_table *ctl_table_path;
+ struct ctl_table *ctl_table;
+#endif /* CONFIG_SYSCTL */
+
/* Module (if any) which this is connected to. */
struct module *me;
};
diff --git a/include/net/netfilter/nf_conntrack_l4proto.h b/include/net/netfilter/nf_conntrack_l4proto.h
index c22804a..fe1e8fa 100644
--- a/include/net/netfilter/nf_conntrack_l4proto.h
+++ b/include/net/netfilter/nf_conntrack_l4proto.h
@@ -76,6 +76,12 @@
int (*nfattr_to_tuple)(struct nfattr *tb[],
struct nf_conntrack_tuple *t);
+#ifdef CONFIG_SYSCTL
+ struct ctl_table_header **ctl_table_header;
+ struct ctl_table *ctl_table;
+ unsigned int *ctl_table_users;
+#endif /* CONFIG_SYSCTL */
+
/* Module (if any) which this is connected to. */
struct module *me;
};
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 627105d..84d529de 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -4,6 +4,7 @@
nf_conntrack-$(CONFIG_NF_CONNTRACK_EVENTS) += nf_conntrack_ecache.o
obj-$(CONFIG_NETFILTER) = netfilter.o
+obj-$(CONFIG_SYSCTL) += nf_sysctl.o
obj-$(CONFIG_NETFILTER_NETLINK) += nfnetlink.o
obj-$(CONFIG_NETFILTER_NETLINK_QUEUE) += nfnetlink_queue.o
diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c
index a6a3b1d..941b5c3 100644
--- a/net/netfilter/nf_conntrack_proto.c
+++ b/net/netfilter/nf_conntrack_proto.c
@@ -12,6 +12,7 @@
#include <linux/types.h>
#include <linux/netfilter.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/skbuff.h>
#include <linux/vmalloc.h>
#include <linux/stddef.h>
@@ -30,6 +31,34 @@
struct nf_conntrack_l4proto **nf_ct_protos[PF_MAX] __read_mostly;
struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX] __read_mostly;
+#ifdef CONFIG_SYSCTL
+static DEFINE_MUTEX(nf_ct_proto_sysctl_mutex);
+
+static int
+nf_ct_register_sysctl(struct ctl_table_header **header, struct ctl_table *path,
+ struct ctl_table *table, unsigned int *users)
+{
+ if (*header == NULL) {
+ *header = nf_register_sysctl_table(path, table);
+ if (*header == NULL)
+ return -ENOMEM;
+ }
+ if (users != NULL)
+ (*users)++;
+ return 0;
+}
+
+static void
+nf_ct_unregister_sysctl(struct ctl_table_header **header,
+ struct ctl_table *table, unsigned int *users)
+{
+ if (users != NULL && --*users > 0)
+ return;
+ nf_unregister_sysctl_table(*header, table);
+ *header = NULL;
+}
+#endif
+
struct nf_conntrack_l4proto *
__nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto)
{
@@ -124,6 +153,33 @@
l4proto->l3proto);
}
+static int nf_ct_l3proto_register_sysctl(struct nf_conntrack_l3proto *l3proto)
+{
+ int err = 0;
+
+#ifdef CONFIG_SYSCTL
+ mutex_lock(&nf_ct_proto_sysctl_mutex);
+ if (l3proto->ctl_table != NULL) {
+ err = nf_ct_register_sysctl(&l3proto->ctl_table_header,
+ l3proto->ctl_table_path,
+ l3proto->ctl_table, NULL);
+ }
+ mutex_unlock(&nf_ct_proto_sysctl_mutex);
+#endif
+ return err;
+}
+
+static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto)
+{
+#ifdef CONFIG_SYSCTL
+ mutex_lock(&nf_ct_proto_sysctl_mutex);
+ if (l3proto->ctl_table_header != NULL)
+ nf_ct_unregister_sysctl(&l3proto->ctl_table_header,
+ l3proto->ctl_table, NULL);
+ mutex_unlock(&nf_ct_proto_sysctl_mutex);
+#endif
+}
+
int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
{
int ret = 0;
@@ -139,6 +195,12 @@
goto out_unlock;
}
nf_ct_l3protos[proto->l3proto] = proto;
+ write_unlock_bh(&nf_conntrack_lock);
+
+ ret = nf_ct_l3proto_register_sysctl(proto);
+ if (ret < 0)
+ nf_conntrack_l3proto_unregister(proto);
+ return ret;
out_unlock:
write_unlock_bh(&nf_conntrack_lock);
@@ -165,6 +227,8 @@
nf_ct_l3protos[proto->l3proto] = &nf_conntrack_l3proto_generic;
write_unlock_bh(&nf_conntrack_lock);
+ nf_ct_l3proto_unregister_sysctl(proto);
+
/* Somebody could be still looking at the proto in bh. */
synchronize_net();
@@ -175,6 +239,36 @@
return ret;
}
+static int nf_ct_l4proto_register_sysctl(struct nf_conntrack_l4proto *l4proto)
+{
+ int err = 0;
+
+#ifdef CONFIG_SYSCTL
+ mutex_lock(&nf_ct_proto_sysctl_mutex);
+ if (l4proto->ctl_table != NULL) {
+ err = nf_ct_register_sysctl(l4proto->ctl_table_header,
+ nf_net_netfilter_sysctl_path,
+ l4proto->ctl_table,
+ l4proto->ctl_table_users);
+ }
+ mutex_unlock(&nf_ct_proto_sysctl_mutex);
+#endif
+ return err;
+}
+
+static void nf_ct_l4proto_unregister_sysctl(struct nf_conntrack_l4proto *l4proto)
+{
+#ifdef CONFIG_SYSCTL
+ mutex_lock(&nf_ct_proto_sysctl_mutex);
+ if (l4proto->ctl_table_header != NULL &&
+ *l4proto->ctl_table_header != NULL)
+ nf_ct_unregister_sysctl(l4proto->ctl_table_header,
+ l4proto->ctl_table,
+ l4proto->ctl_table_users);
+ mutex_unlock(&nf_ct_proto_sysctl_mutex);
+#endif
+}
+
/* FIXME: Allow NULL functions and sub in pointers to generic for
them. --RR */
int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
@@ -230,6 +324,12 @@
}
nf_ct_protos[l4proto->l3proto][l4proto->l4proto] = l4proto;
+ write_unlock_bh(&nf_conntrack_lock);
+
+ ret = nf_ct_l4proto_register_sysctl(l4proto);
+ if (ret < 0)
+ nf_conntrack_l4proto_unregister(l4proto);
+ return ret;
out_unlock:
write_unlock_bh(&nf_conntrack_lock);
@@ -257,6 +357,8 @@
= &nf_conntrack_l4proto_generic;
write_unlock_bh(&nf_conntrack_lock);
+ nf_ct_l4proto_unregister_sysctl(l4proto);
+
/* Somebody could be still looking at the proto in bh. */
synchronize_net();
diff --git a/net/netfilter/nf_sysctl.c b/net/netfilter/nf_sysctl.c
new file mode 100644
index 0000000..06ddddb
--- /dev/null
+++ b/net/netfilter/nf_sysctl.c
@@ -0,0 +1,134 @@
+/* nf_sysctl.c netfilter sysctl registration/unregistation
+ *
+ * Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
+ */
+#include <linux/module.h>
+#include <linux/sysctl.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+
+static void
+path_free(struct ctl_table *path, struct ctl_table *table)
+{
+ struct ctl_table *t, *next;
+
+ for (t = path; t != NULL && t != table; t = next) {
+ next = t->child;
+ kfree(t);
+ }
+}
+
+static struct ctl_table *
+path_dup(struct ctl_table *path, struct ctl_table *table)
+{
+ struct ctl_table *t, *last = NULL, *tmp;
+
+ for (t = path; t != NULL; t = t->child) {
+ /* twice the size since path elements are terminated by an
+ * empty element */
+ tmp = kmemdup(t, 2 * sizeof(*t), GFP_KERNEL);
+ if (tmp == NULL) {
+ if (last != NULL)
+ path_free(path, table);
+ return NULL;
+ }
+
+ if (last != NULL)
+ last->child = tmp;
+ else
+ path = tmp;
+ last = tmp;
+ }
+
+ if (last != NULL)
+ last->child = table;
+ else
+ path = table;
+
+ return path;
+}
+
+struct ctl_table_header *
+nf_register_sysctl_table(struct ctl_table *path, struct ctl_table *table)
+{
+ struct ctl_table_header *header;
+
+ path = path_dup(path, table);
+ if (path == NULL)
+ return NULL;
+ header = register_sysctl_table(path, 0);
+ if (header == NULL)
+ path_free(path, table);
+ return header;
+}
+EXPORT_SYMBOL_GPL(nf_register_sysctl_table);
+
+void
+nf_unregister_sysctl_table(struct ctl_table_header *header,
+ struct ctl_table *table)
+{
+ struct ctl_table *path = header->ctl_table;
+
+ unregister_sysctl_table(header);
+ path_free(path, table);
+}
+EXPORT_SYMBOL_GPL(nf_unregister_sysctl_table);
+
+/* net/netfilter */
+static struct ctl_table nf_net_netfilter_table[] = {
+ {
+ .ctl_name = NET_NETFILTER,
+ .procname = "netfilter",
+ .mode = 0555,
+ },
+ {
+ .ctl_name = 0
+ }
+};
+struct ctl_table nf_net_netfilter_sysctl_path[] = {
+ {
+ .ctl_name = CTL_NET,
+ .procname = "net",
+ .mode = 0555,
+ .child = nf_net_netfilter_table,
+ },
+ {
+ .ctl_name = 0
+ }
+};
+EXPORT_SYMBOL_GPL(nf_net_netfilter_sysctl_path);
+
+/* net/ipv4/netfilter */
+static struct ctl_table nf_net_ipv4_netfilter_table[] = {
+ {
+ .ctl_name = NET_IPV4_NETFILTER,
+ .procname = "netfilter",
+ .mode = 0555,
+ },
+ {
+ .ctl_name = 0
+ }
+};
+static struct ctl_table nf_net_ipv4_table[] = {
+ {
+ .ctl_name = NET_IPV4,
+ .procname = "ipv4",
+ .mode = 0555,
+ .child = nf_net_ipv4_netfilter_table,
+ },
+ {
+ .ctl_name = 0
+ }
+};
+struct ctl_table nf_net_ipv4_netfilter_sysctl_path[] = {
+ {
+ .ctl_name = CTL_NET,
+ .procname = "net",
+ .mode = 0555,
+ .child = nf_net_ipv4_table,
+ },
+ {
+ .ctl_name = 0
+ }
+};
+EXPORT_SYMBOL_GPL(nf_net_ipv4_netfilter_sysctl_path);