[7/9] fanotify: userspace socket

diff --git a/fs/notify/fanotify/Makefile b/fs/notify/fanotify/Makefile
index e7d39c0..1196005 100644
--- a/fs/notify/fanotify/Makefile
+++ b/fs/notify/fanotify/Makefile
@@ -1 +1 @@ 
-obj-$(CONFIG_FANOTIFY)		+= fanotify.o
+obj-$(CONFIG_FANOTIFY)		+= fanotify.o af_fanotify.o
diff --git a/fs/notify/fanotify/af_fanotify.c b/fs/notify/fanotify/af_fanotify.c
new file mode 100644
index 0000000..d7bf658
--- /dev/null
+++ b/fs/notify/fanotify/af_fanotify.c
@@ -0,0 +1,152 @@ 
+#include <linux/errno.h>
+#include <linux/fdtable.h>
+#include <linux/file.h>
+#include <linux/fsnotify_backend.h>
+#include <linux/init.h>
+#include <linux/kernel.h> /* UINT_MAX */
+#include <linux/mount.h> /* mntget() */
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/socket.h>
+#include <linux/types.h>
+
+#include <net/net_namespace.h>
+#include <net/sock.h>
+
+#include "fanotify.h"
+#include "af_fanotify.h"
+
+static const struct proto_ops fanotify_proto_ops;
+
+static struct proto fanotify_proto = {
+	.name     = "FANOTIFY",
+	.owner    = THIS_MODULE,
+	.obj_size = sizeof(struct fanotify_sock),
+};
+
+static int fan_sock_create(struct net *net, struct socket *sock, int protocol)
+{
+	struct sock *sk;
+	struct fanotify_sock *fan_sock;
+
+	/* FIXME maybe a new LSM hook? */
+	if (!capable(CAP_NET_RAW))
+		return -EPERM;
+
+	if (protocol != 0)
+		return -ESOCKTNOSUPPORT;
+
+	if (sock->type != SOCK_RAW)
+		return -ESOCKTNOSUPPORT;
+
+	sock->state = SS_UNCONNECTED;
+
+	sk = sk_alloc(net, PF_FANOTIFY, GFP_KERNEL, &fanotify_proto);
+	if (sk == NULL)
+		return -ENOBUFS;
+
+	sock->ops = &fanotify_proto_ops;
+
+	sock_init_data(sock, sk);
+
+	sk->sk_family = PF_FANOTIFY;
+	sk_refcnt_debug_inc(sk);
+
+	fan_sock = fan_sk(sk);
+	fan_sock->group = NULL;
+
+	return 0;
+}
+
+static int fan_release(struct socket *sock)
+{
+	struct sock *sk;
+	struct fanotify_sock *fan_sock;
+
+	sk = sock->sk;
+	if (!sk)
+		return 0;
+
+	fan_sock = fan_sk(sk);
+
+	if (sock->state == SS_CONNECTED) {
+		sock->state = SS_UNCONNECTED;
+		fsnotify_put_group(fan_sock->group);
+	}
+
+	fan_sock->group = NULL;
+
+	sock_orphan(sk);
+	sock->sk = NULL;
+
+	sk_refcnt_debug_release(sk);
+
+	sock_put(sk);
+
+	return 0;
+}
+
+static int fan_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
+{
+	struct fanotify_addr *fan_addr = (struct fanotify_addr *)addr;
+	struct fanotify_sock *fan_sock;
+
+	if (addr_len != sizeof(struct fanotify_addr))
+		return -EINVAL;
+
+	if (sock->state != SS_UNCONNECTED)
+		return -EINVAL;
+
+	if (!fanotify_is_mask_valid(fan_addr->mask))
+		return -EINVAL;
+
+	fan_sock = fan_sk(sock->sk);
+	fan_sock->group = fsnotify_obtain_group(fan_addr->mask, &fanotify_ops);
+
+	if (IS_ERR(fan_sock->group))
+		return PTR_ERR(fan_sock->group);
+
+	fan_sock->group->max_events = 16383;
+
+	sock->state = SS_CONNECTED;
+
+	return 0;
+}
+
+static const struct net_proto_family fanotify_family_ops = {
+	.family		=	PF_FANOTIFY,
+	.create		=	fan_sock_create,
+	.owner		=	THIS_MODULE,
+};
+
+static const struct proto_ops fanotify_proto_ops = {
+	.family =	PF_FANOTIFY,
+	.owner =	THIS_MODULE,
+	.release =	fan_release,
+	.bind =		fan_bind,
+	.connect =	sock_no_connect,
+	.socketpair =	sock_no_socketpair,
+	.accept =	sock_no_accept,
+	.getname =	sock_no_getname,
+	.poll =		sock_no_poll,
+	.ioctl =	sock_no_ioctl,
+	.listen =	sock_no_listen,
+	.shutdown =	sock_no_shutdown,
+	.setsockopt =	sock_no_setsockopt,
+	.getsockopt =	sock_no_getsockopt,
+	.sendmsg =	sock_no_sendmsg,
+	.recvmsg =	sock_no_recvmsg,
+	.mmap =		sock_no_mmap,
+	.sendpage =	sock_no_sendpage,
+};
+
+static int __init fanotify_init(void)
+{
+	if (proto_register(&fanotify_proto, 0))
+		panic("unable to register fanotify protocol with network stack\n");
+
+	sock_register(&fanotify_family_ops);
+
+	return 0;
+}
+device_initcall(fanotify_init);
diff --git a/fs/notify/fanotify/af_fanotify.h b/fs/notify/fanotify/af_fanotify.h
new file mode 100644
index 0000000..fff0e66
--- /dev/null
+++ b/fs/notify/fanotify/af_fanotify.h
@@ -0,0 +1,21 @@ 
+#ifndef _LINUX_AF_FANOTIFY_H
+#define _LINUX_AF_FANOTIFY_H
+
+#include <linux/fanotify.h>
+#include <net/sock.h>
+
+struct fanotify_sock {
+	struct sock		sock;
+	struct fsnotify_group	*group;
+};
+
+static inline struct fanotify_sock *fan_sk(struct sock *sock)
+{
+	struct fanotify_sock *fan_sock;
+
+	fan_sock = container_of(sock, struct fanotify_sock, sock);
+
+	return fan_sock;
+}
+
+#endif /* _LINUX_AF_NET_H */
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index a8785c1..6c7bf06 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -4,6 +4,8 @@ 
 #include <linux/kernel.h>
 #include <linux/types.h>
 
+extern const struct fsnotify_ops fanotify_ops;
+
 static inline bool fanotify_is_mask_valid(__u32 mask)
 {
 	if (mask & ~(FAN_ALL_INCOMING_EVENTS))
diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
index b560f86..31fa74d 100644
--- a/include/linux/fanotify.h
+++ b/include/linux/fanotify.h
@@ -1,6 +1,7 @@ 
 #ifndef _LINUX_FANOTIFY_H
 #define _LINUX_FANOTIFY_H
 
+#include <linux/socket.h>
 #include <linux/types.h>
 
 /* the following events that user-space can register for */
@@ -34,6 +35,24 @@ 
  */
 #define FAN_ALL_INCOMING_EVENTS	(FAN_ALL_EVENTS |\
 				 FAN_EVENT_ON_CHILD)
+#ifndef SOL_FANOTIFY
+#define SOL_FANOTIFY	278
+#endif
+
+#ifndef AF_FANOTIFY
+#define AF_FANOTIFY	37
+#define PF_FANOTIFY	AF_FANOTIFY
+#endif
+
+struct fanotify_addr {
+	sa_family_t family;
+	__u32 priority; /* unused */
+	__u32 mask_hi; /* unused */
+	__u32 mask;
+	__u32 f_flags; /* unused */
+	__u32 unused[16];
+}  __attribute__((packed));
+
 #ifdef __KERNEL__
 
 #endif /* __KERNEL__ */