sock_diag: Move the sock_ code to net/core/

This patch moves the sock_ code from inet_diag.c to generic sock_diag.c
file and provides necessary request_module-s calls and a pointer on
inet_diag_compat dumping routine.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 152 insertions, 1 deletions

diff --git a/net/core/Makefile b/net/core/Makefile
index c4ecc864020..674641b13ae 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -8,7 +8,8 @@ obj-y := sock.o request_sock.o skbuff.o iovec.o datagram.o stream.o scm.o \
 obj-$(CONFIG_SYSCTL) += sysctl_net_core.o
 
 obj-y		     += dev.o ethtool.o dev_addr_lists.o dst.o netevent.o \
-			neighbour.o rtnetlink.o utils.o link_watch.o filter.o
+			neighbour.o rtnetlink.o utils.o link_watch.o filter.o \
+			sock_diag.o
 
 obj-$(CONFIG_XFRM) += flow.o
 obj-y += net-sysfs.o
diff --git a/net/core/sock_diag.c b/net/core/sock_diag.c
new file mode 100644
index 00000000000..fbaf01ce12f
--- /dev/null
+++ b/net/core/sock_diag.c
@@ -0,0 +1,150 @@
+#include <linux/mutex.h>
+#include <linux/socket.h>
+#include <linux/skbuff.h>
+#include <net/netlink.h>
+#include <net/net_namespace.h>
+#include <linux/module.h>
+
+#include <linux/inet_diag.h>
+#include <linux/sock_diag.h>
+
+static struct sock_diag_handler *sock_diag_handlers[AF_MAX];
+static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh);
+static DEFINE_MUTEX(sock_diag_table_mutex);
+
+void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
+{
+	mutex_lock(&sock_diag_table_mutex);
+	inet_rcv_compat = fn;
+	mutex_unlock(&sock_diag_table_mutex);
+}
+EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
+
+void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
+{
+	mutex_lock(&sock_diag_table_mutex);
+	inet_rcv_compat = NULL;
+	mutex_unlock(&sock_diag_table_mutex);
+}
+EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
+
+int sock_diag_register(struct sock_diag_handler *hndl)
+{
+	int err = 0;
+
+	if (hndl->family > AF_MAX)
+		return -EINVAL;
+
+	mutex_lock(&sock_diag_table_mutex);
+	if (sock_diag_handlers[hndl->family])
+		err = -EBUSY;
+	else
+		sock_diag_handlers[hndl->family] = hndl;
+	mutex_unlock(&sock_diag_table_mutex);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(sock_diag_register);
+
+void sock_diag_unregister(struct sock_diag_handler *hnld)
+{
+	int family = hnld->family;
+
+	if (family > AF_MAX)
+		return;
+
+	mutex_lock(&sock_diag_table_mutex);
+	BUG_ON(sock_diag_handlers[family] != hnld);
+	sock_diag_handlers[family] = NULL;
+	mutex_unlock(&sock_diag_table_mutex);
+}
+EXPORT_SYMBOL_GPL(sock_diag_unregister);
+
+static inline struct sock_diag_handler *sock_diag_lock_handler(int family)
+{
+	if (sock_diag_handlers[family] == NULL)
+		request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
+				NETLINK_SOCK_DIAG, IPPROTO_IP);
+
+	mutex_lock(&sock_diag_table_mutex);
+	return sock_diag_handlers[family];
+}
+
+static inline void sock_diag_unlock_handler(struct sock_diag_handler *h)
+{
+	mutex_unlock(&sock_diag_table_mutex);
+}
+
+static int __sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+	int err;
+	struct sock_diag_req *req = NLMSG_DATA(nlh);
+	struct sock_diag_handler *hndl;
+
+	if (nlmsg_len(nlh) < sizeof(*req))
+		return -EINVAL;
+
+	hndl = sock_diag_lock_handler(req->sdiag_family);
+	if (hndl == NULL)
+		err = -ENOENT;
+	else
+		err = hndl->dump(skb, nlh);
+	sock_diag_unlock_handler(hndl);
+
+	return err;
+}
+
+static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+	int ret;
+
+	switch (nlh->nlmsg_type) {
+	case TCPDIAG_GETSOCK:
+	case DCCPDIAG_GETSOCK:
+		if (inet_rcv_compat == NULL)
+			request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
+					NETLINK_SOCK_DIAG, IPPROTO_IP);
+
+		mutex_lock(&sock_diag_table_mutex);
+		if (inet_rcv_compat != NULL)
+			ret = inet_rcv_compat(skb, nlh);
+		else
+			ret = -EOPNOTSUPP;
+		mutex_unlock(&sock_diag_table_mutex);
+
+		return ret;
+	case SOCK_DIAG_BY_FAMILY:
+		return __sock_diag_rcv_msg(skb, nlh);
+	default:
+		return -EINVAL;
+	}
+}
+
+static DEFINE_MUTEX(sock_diag_mutex);
+
+static void sock_diag_rcv(struct sk_buff *skb)
+{
+	mutex_lock(&sock_diag_mutex);
+	netlink_rcv_skb(skb, &sock_diag_rcv_msg);
+	mutex_unlock(&sock_diag_mutex);
+}
+
+struct sock *sock_diag_nlsk;
+EXPORT_SYMBOL_GPL(sock_diag_nlsk);
+
+static int __init sock_diag_init(void)
+{
+	sock_diag_nlsk = netlink_kernel_create(&init_net, NETLINK_SOCK_DIAG, 0,
+					sock_diag_rcv, NULL, THIS_MODULE);
+	return sock_diag_nlsk == NULL ? -ENOMEM : 0;
+}
+
+static void __exit sock_diag_exit(void)
+{
+	netlink_kernel_release(sock_diag_nlsk);
+}
+
+module_init(sock_diag_init);
+module_exit(sock_diag_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG);