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>

3 files changed, 158 insertions, 100 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);
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index 515dc7b6dae..b56b7ba8bee 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -46,8 +46,6 @@ struct inet_diag_entry {
         u16 userlocks;
 };
 
-static struct sock *sdiagnl;
-
 #define INET_DIAG_PUT(skb, attrtype, attrlen) \
         RTA_DATA(__RTA_PUT(skb, attrtype, attrlen))
 
@@ -314,7 +312,7 @@ static int inet_diag_get_exact(struct sk_buff *in_skb,
                 kfree_skb(rep);
                 goto out;
         }
-        err = netlink_unicast(sdiagnl, rep, NETLINK_CB(in_skb).pid,
+        err = netlink_unicast(sock_diag_nlsk, rep, NETLINK_CB(in_skb).pid,
                               MSG_DONTWAIT);
         if (err > 0)
                 err = 0;
@@ -931,7 +929,7 @@ static int inet_diag_rcv_msg_compat(struct sk_buff *skb, struct nlmsghdr *nlh)
                                 return -EINVAL;
                 }
 
-                return netlink_dump_start(sdiagnl, skb, nlh,
+                return netlink_dump_start(sock_diag_nlsk, skb, nlh,
                                           inet_diag_dump_compat, NULL, 0);
         }
 
@@ -956,7 +954,7 @@ static int inet_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
                                 return -EINVAL;
                 }
 
-                return netlink_dump_start(sdiagnl, skb, h,
+                return netlink_dump_start(sock_diag_nlsk, skb, h,
                                           inet_diag_dump, NULL, 0);
         }
 
@@ -973,91 +971,6 @@ static struct sock_diag_handler inet6_diag_handler = {
         .dump = inet_diag_handler_dump,
 };
 
-static struct sock_diag_handler *sock_diag_handlers[AF_MAX];
-static DEFINE_MUTEX(sock_diag_table_mutex);
-
-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;
-}
-
-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);
-}
-
-static inline struct sock_diag_handler *sock_diag_lock_handler(int family)
-{
-        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)
-{
-        switch (nlh->nlmsg_type) {
-        case TCPDIAG_GETSOCK:
-        case DCCPDIAG_GETSOCK:
-                return inet_diag_rcv_msg_compat(skb, nlh);
-        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);
-}
-
 int inet_diag_register(const struct inet_diag_handler *h)
 {
         const __u16 type = h->idiag_type;
@@ -1101,11 +1014,6 @@ static int __init inet_diag_init(void)
         if (!inet_diag_table)
                 goto out;
 
-        sdiagnl = netlink_kernel_create(&init_net, NETLINK_SOCK_DIAG, 0,
-                                        sock_diag_rcv, NULL, THIS_MODULE);
-        if (sdiagnl == NULL)
-                goto out_free_table;
-
         err = sock_diag_register(&inet_diag_handler);
         if (err)
                 goto out_free_nl;
@@ -1114,14 +1022,13 @@ static int __init inet_diag_init(void)
         if (err)
                 goto out_free_inet;
 
+        sock_diag_register_inet_compat(inet_diag_rcv_msg_compat);
 out:
         return err;
 
 out_free_inet:
         sock_diag_unregister(&inet_diag_handler);
 out_free_nl:
-        netlink_kernel_release(sdiagnl);
-out_free_table:
         kfree(inet_diag_table);
         goto out;
 }
@@ -1130,11 +1037,11 @@ static void __exit inet_diag_exit(void)
 {
         sock_diag_unregister(&inet6_diag_handler);
         sock_diag_unregister(&inet_diag_handler);
-        netlink_kernel_release(sdiagnl);
+        sock_diag_unregister_inet_compat(inet_diag_rcv_msg_compat);
         kfree(inet_diag_table);
 }
 
 module_init(inet_diag_init);
 module_exit(inet_diag_exit);
 MODULE_LICENSE("GPL");
-MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_SOCK_DIAG);
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 0);