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 c4ecc864020f..674641b13aea 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 000000000000..fbaf01ce12f2
--- /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);