1 files changed, 78 insertions, 5 deletions

diff --git a/net/socket.c b/net/socket.c
index a5471f804d99..977c0f48c8d6 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -88,6 +88,7 @@
 #include <linux/nsproxy.h>
 #include <linux/magic.h>
 #include <linux/slab.h>
+#include <linux/xattr.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -346,7 +347,8 @@ static struct file_system_type sock_fs_type = {
  *	but we take care of internal coherence yet.
  */
 
-static int sock_alloc_file(struct socket *sock, struct file **f, int flags)
+static int sock_alloc_file(struct socket *sock, struct file **f, int flags,
+			   const char *dname)
 {
 	struct qstr name = { .name = "" };
 	struct path path;
@@ -357,6 +359,13 @@ static int sock_alloc_file(struct socket *sock, struct file **f, int flags)
 	if (unlikely(fd < 0))
 		return fd;
 
+	if (dname) {
+		name.name = dname;
+		name.len = strlen(name.name);
+	} else if (sock->sk) {
+		name.name = sock->sk->sk_prot_creator->name;
+		name.len = strlen(name.name);
+	}
 	path.dentry = d_alloc_pseudo(sock_mnt->mnt_sb, &name);
 	if (unlikely(!path.dentry)) {
 		put_unused_fd(fd);
@@ -389,7 +398,7 @@ static int sock_alloc_file(struct socket *sock, struct file **f, int flags)
 int sock_map_fd(struct socket *sock, int flags)
 {
 	struct file *newfile;
-	int fd = sock_alloc_file(sock, &newfile, flags);
+	int fd = sock_alloc_file(sock, &newfile, flags, NULL);
 
 	if (likely(fd >= 0))
 		fd_install(fd, newfile);
@@ -455,6 +464,68 @@ static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed)
 	return NULL;
 }
 
+#define XATTR_SOCKPROTONAME_SUFFIX "sockprotoname"
+#define XATTR_NAME_SOCKPROTONAME (XATTR_SYSTEM_PREFIX XATTR_SOCKPROTONAME_SUFFIX)
+#define XATTR_NAME_SOCKPROTONAME_LEN (sizeof(XATTR_NAME_SOCKPROTONAME)-1)
+static ssize_t sockfs_getxattr(struct dentry *dentry,
+			       const char *name, void *value, size_t size)
+{
+	const char *proto_name;
+	size_t proto_size;
+	int error;
+
+	error = -ENODATA;
+	if (!strncmp(name, XATTR_NAME_SOCKPROTONAME, XATTR_NAME_SOCKPROTONAME_LEN)) {
+		proto_name = dentry->d_name.name;
+		proto_size = strlen(proto_name);
+
+		if (value) {
+			error = -ERANGE;
+			if (proto_size + 1 > size)
+				goto out;
+
+			strncpy(value, proto_name, proto_size + 1);
+		}
+		error = proto_size + 1;
+	}
+
+out:
+	return error;
+}
+
+static ssize_t sockfs_listxattr(struct dentry *dentry, char *buffer,
+				size_t size)
+{
+	ssize_t len;
+	ssize_t used = 0;
+
+	len = security_inode_listsecurity(dentry->d_inode, buffer, size);
+	if (len < 0)
+		return len;
+	used += len;
+	if (buffer) {
+		if (size < used)
+			return -ERANGE;
+		buffer += len;
+	}
+
+	len = (XATTR_NAME_SOCKPROTONAME_LEN + 1);
+	used += len;
+	if (buffer) {
+		if (size < used)
+			return -ERANGE;
+		memcpy(buffer, XATTR_NAME_SOCKPROTONAME, len);
+		buffer += len;
+	}
+
+	return used;
+}
+
+static const struct inode_operations sockfs_inode_ops = {
+	.getxattr = sockfs_getxattr,
+	.listxattr = sockfs_listxattr,
+};
+
 /**
  *	sock_alloc	-	allocate a socket
  *
@@ -479,6 +550,7 @@ static struct socket *sock_alloc(void)
 	inode->i_mode = S_IFSOCK | S_IRWXUGO;
 	inode->i_uid = current_fsuid();
 	inode->i_gid = current_fsgid();
+	inode->i_op = &sockfs_inode_ops;
 
 	this_cpu_add(sockets_in_use, 1);
 	return sock;
@@ -1394,13 +1466,13 @@ SYSCALL_DEFINE4(socketpair, int, family, int, type, int, protocol,
 	if (err < 0)
 		goto out_release_both;
 
-	fd1 = sock_alloc_file(sock1, &newfile1, flags);
+	fd1 = sock_alloc_file(sock1, &newfile1, flags, NULL);
 	if (unlikely(fd1 < 0)) {
 		err = fd1;
 		goto out_release_both;
 	}
 
-	fd2 = sock_alloc_file(sock2, &newfile2, flags);
+	fd2 = sock_alloc_file(sock2, &newfile2, flags, NULL);
 	if (unlikely(fd2 < 0)) {
 		err = fd2;
 		fput(newfile1);
@@ -1536,7 +1608,8 @@ SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
 	 */
 	__module_get(newsock->ops->owner);
 
-	newfd = sock_alloc_file(newsock, &newfile, flags);
+	newfd = sock_alloc_file(newsock, &newfile, flags,
+				sock->sk->sk_prot_creator->name);
 	if (unlikely(newfd < 0)) {
 		err = newfd;
 		sock_release(newsock);