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);