[PATCH] LSM networking: af_unix hooks for 2.5.42 (6/7)

From: James Morris (jmorrisat_private)
Date: Tue Oct 15 2002 - 07:40:35 PDT

  • Next message: James Morris: "[PATCH] LSM networking: tcp hooks for 2.5.42 (7/7)"

    diff -urN -X dontdiff linux-2.5.42.w0/include/linux/security.h linux-2.5.42.w1/include/linux/security.h
    --- linux-2.5.42.w0/include/linux/security.h	Tue Oct 15 21:10:02 2002
    +++ linux-2.5.42.w1/include/linux/security.h	Tue Oct 15 21:10:26 2002
    @@ -850,6 +850,29 @@
      *	@skb contains the sk_buff structure for the netlink message.
      *	Return 0 if permission is granted.
      *
    + * @unix_stream_connect:
    + *	Check permissions before establishing a Unix domain stream connection
    + *	between @sock and @other.
    + *	@sock contains the socket structure.
    + *	@other contains the peer socket structure.
    + *	Return 0 if permission is granted.
    + * @unix_may_send:
    + *	Check permissions before connecting or sending datagrams from @sock to
    + *	@other.
    + *	@sock contains the socket structure.
    + *	@sock contains the peer socket structure.
    + *	Return 0 if permission is granted.
    + *
    + * The @unix_stream_connect and @unix_may_send hooks were necessary because
    + * Linux provides an alternative to the conventional file name space for Unix
    + * domain sockets.  Whereas binding and connecting to sockets in the file name
    + * space is mediated by the typical file permissions (and caught by the mknod
    + * and permission hooks in inode_security_ops), binding and connecting to
    + * sockets in the abstract name space is completely unmediated.  Sufficient
    + * control of Unix domain sockets in the abstract name space isn't possible
    + * using only the socket layer hooks, since we need to know the actual target
    + * socket, which is not looked up until we are inside the af_unix code.
    + *
      * @ptrace:
      *	Check permission before allowing the @parent process to trace the
      *	@child process.
    @@ -1111,6 +1134,10 @@
     	int (*netlink_send) (struct sk_buff * skb);
     	int (*netlink_recv) (struct sk_buff * skb);
     
    +	int (*unix_stream_connect) (struct socket * sock,
    +				    struct socket * other, struct sock * newsk);
    +	int (*unix_may_send) (struct socket * sock, struct socket * other);
    +
     	int (*ipc_permission) (struct kern_ipc_perm * ipcp, short flag);
     
     	int (*msg_queue_alloc_security) (struct msg_queue * msq);
    diff -urN -X dontdiff linux-2.5.42.w0/net/unix/af_unix.c linux-2.5.42.w1/net/unix/af_unix.c
    --- linux-2.5.42.w0/net/unix/af_unix.c	Wed Aug 28 13:24:30 2002
    +++ linux-2.5.42.w1/net/unix/af_unix.c	Tue Oct 15 21:10:26 2002
    @@ -111,6 +111,7 @@
     #include <linux/smp_lock.h>
     #include <linux/rtnetlink.h>
     #include <net/checksum.h>
    +#include <linux/security.h>
     
     int sysctl_unix_max_dgram_qlen = 10;
     
    @@ -812,6 +813,11 @@
     		err = -EPERM;
     		if (!unix_may_send(sk, other))
     			goto out_unlock;
    +
    +		err = security_ops->unix_may_send(sk->socket, other->socket);
    +		if (err)
    +			goto out_unlock;
    +
     	} else {
     		/*
     		 *	1003.1g breaking connected state with AF_UNSPEC
    @@ -977,6 +983,12 @@
     		goto restart;
     	}
     
    +	err = security_ops->unix_stream_connect(sock, other->socket, newsk);
    +	if (err) {
    +		unix_state_wunlock(sk);
    +		goto out_unlock;
    +	}
    +
     	/* The way is open! Fastly set all the necessary fields... */
     
     	sock_hold(sk);
    @@ -1274,6 +1286,10 @@
     	if (other->shutdown&RCV_SHUTDOWN)
     		goto out_unlock;
     
    +	err = security_ops->unix_may_send(sk->socket, other->socket);
    +	if (err)
    +		goto out_unlock;
    +
     	if (unix_peer(other) != sk &&
     	    skb_queue_len(&other->receive_queue) > other->max_ack_backlog) {
     		if (!timeo) {
    diff -urN -X dontdiff linux-2.5.42.w0/security/capability.c linux-2.5.42.w1/security/capability.c
    --- linux-2.5.42.w0/security/capability.c	Tue Oct 15 21:10:02 2002
    +++ linux-2.5.42.w1/security/capability.c	Tue Oct 15 21:10:26 2002
    @@ -885,6 +885,18 @@
     	return 0;
     }
     
    +static int cap_socket_unix_stream_connect (struct socket *sock,
    +					   struct socket *other,
    +					   struct sock *newsk)
    +{
    +	return 0;
    +}
    +
    +static int cap_socket_unix_may_send (struct socket *sock, struct socket *other)
    +{
    +	return 0;
    +}
    +
     static int cap_register (const char *name, struct security_operations *ops)
     {
     	return -EINVAL;
    @@ -1022,6 +1034,9 @@
     	.netlink_send =			cap_netlink_send,
     	.netlink_recv =			cap_netlink_recv,
     
    +	.unix_stream_connect =		cap_socket_unix_stream_connect,
    +	.unix_may_send =		cap_socket_unix_may_send,
    +
     	.ipc_permission =		cap_ipc_permission,
     
     	.msg_queue_alloc_security =	cap_msg_queue_alloc_security,
    diff -urN -X dontdiff linux-2.5.42.w0/security/dummy.c linux-2.5.42.w1/security/dummy.c
    --- linux-2.5.42.w0/security/dummy.c	Tue Oct 15 21:10:02 2002
    +++ linux-2.5.42.w1/security/dummy.c	Tue Oct 15 21:10:26 2002
    @@ -705,6 +705,19 @@
     	return 0;
     }
     
    +static int dummy_socket_unix_stream_connect (struct socket *sock,
    +					     struct socket *other,
    +					     struct sock *newsk)
    +{
    +	return 0;
    +}
    +
    +static int dummy_socket_unix_may_send (struct socket *sock,
    +				       struct socket *other)
    +{
    +	return 0;
    +}
    +
     static int dummy_register (const char *name, struct security_operations *ops)
     {
     	return -EINVAL;
    @@ -842,6 +855,9 @@
     	.netlink_send =			dummy_netlink_send,
     	.netlink_recv =			dummy_netlink_recv,
     
    +	.unix_stream_connect =		dummy_socket_unix_stream_connect,
    +	.unix_may_send =		dummy_socket_unix_may_send,
    +
     	.ipc_permission =		dummy_ipc_permission,
     	
     	.msg_queue_alloc_security =	dummy_msg_queue_alloc_security,
    
    
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