Commit c16d2380 authored by Jeremy Kerr's avatar Jeremy Kerr Committed by Paolo Abeni
Browse files

net: mctp: provide a more specific tag allocation ioctl 



Now that we have net-specific tags, extend the tag allocation ioctls
(SIOCMCTPALLOCTAG / SIOCMCTPDROPTAG) to allow a network parameter to be
passed to the tag allocation.

We also add a local_addr member to the ioc struct, to allow for a future
finer-grained tag allocation using local EIDs too. We don't add any
specific support for that now though, so require MCTP_ADDR_ANY or
MCTP_ADDR_NULL for those at present.

The old ioctls will still work, but allocate for the default MCTP net.
These are now marked as deprecated in the header.

Signed-off-by: default avatarJeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 43e67955

include/uapi/linux/mctp.h

+32 −0
Original line number Diff line number Diff line
@@ -50,7 +50,14 @@ struct sockaddr_mctp_ext { 


#define SIOCMCTPALLOCTAG	(SIOCPROTOPRIVATE + 0)

#define SIOCMCTPDROPTAG		(SIOCPROTOPRIVATE + 1)

#define SIOCMCTPALLOCTAG2	(SIOCPROTOPRIVATE + 2)

#define SIOCMCTPDROPTAG2	(SIOCPROTOPRIVATE + 3)



/* Deprecated: use mctp_ioc_tag_ctl2 / TAG2 ioctls instead, which defines the

 * MCTP network ID as part of the allocated tag. Using this assumes the default

 * net ID for allocated tags, which may not give correct behaviour on system

 * with multiple networks configured.

 */

struct mctp_ioc_tag_ctl {

	mctp_eid_t	peer_addr;
@@ -65,4 +72,29 @@ struct mctp_ioc_tag_ctl { 
	__u16		flags;

};



struct mctp_ioc_tag_ctl2 {

	/* Peer details: network ID, peer EID, local EID. All set by the

	 * caller.

	 *

	 * Local EID must be MCTP_ADDR_NULL or MCTP_ADDR_ANY in current

	 * kernels.

	 */

	unsigned int	net;

	mctp_eid_t	peer_addr;

	mctp_eid_t	local_addr;



	/* Set by caller, but no flags defined currently. Must be 0 */

	__u16		flags;



	/* For SIOCMCTPALLOCTAG2: must be passed as zero, kernel will

	 * populate with the allocated tag value. Returned tag value will

	 * always have TO and PREALLOC set.

	 *

	 * For SIOCMCTPDROPTAG2: userspace provides tag value to drop, from

	 * a prior SIOCMCTPALLOCTAG2 call (and so must have TO and PREALLOC set).

	 */

	__u8		tag;



};



#endif /* __UAPI_MCTP_H */

net/mctp/af_mctp.c

+97 −20
Original line number Diff line number Diff line
@@ -350,30 +350,102 @@ static int mctp_getsockopt(struct socket *sock, int level, int optname, 
	return -EINVAL;

}



static int mctp_ioctl_alloctag(struct mctp_sock *msk, unsigned long arg)

/* helpers for reading/writing the tag ioc, handling compatibility across the

 * two versions, and some basic API error checking

 */

static int mctp_ioctl_tag_copy_from_user(unsigned long arg,

					 struct mctp_ioc_tag_ctl2 *ctl,

					 bool tagv2)

{

	struct mctp_ioc_tag_ctl ctl_compat;

	unsigned long size;

	void *ptr;

	int rc;



	if (tagv2) {

		size = sizeof(*ctl);

		ptr = ctl;

	} else {

		size = sizeof(ctl_compat);

		ptr = &ctl_compat;

	}



	rc = copy_from_user(ptr, (void __user *)arg, size);

	if (rc)

		return -EFAULT;



	if (!tagv2) {

		/* compat, using defaults for new fields */

		ctl->net = MCTP_INITIAL_DEFAULT_NET;

		ctl->peer_addr = ctl_compat.peer_addr;

		ctl->local_addr = MCTP_ADDR_ANY;

		ctl->flags = ctl_compat.flags;

		ctl->tag = ctl_compat.tag;

	}



	if (ctl->flags)

		return -EINVAL;



	if (ctl->local_addr != MCTP_ADDR_ANY &&

	    ctl->local_addr != MCTP_ADDR_NULL)

		return -EINVAL;



	return 0;

}



static int mctp_ioctl_tag_copy_to_user(unsigned long arg,

				       struct mctp_ioc_tag_ctl2 *ctl,

				       bool tagv2)

{

	struct mctp_ioc_tag_ctl ctl_compat;

	unsigned long size;

	void *ptr;

	int rc;



	if (tagv2) {

		ptr = ctl;

		size = sizeof(*ctl);

	} else {

		ctl_compat.peer_addr = ctl->peer_addr;

		ctl_compat.tag = ctl->tag;

		ctl_compat.flags = ctl->flags;



		ptr = &ctl_compat;

		size = sizeof(ctl_compat);

	}



	rc = copy_to_user((void __user *)arg, ptr, size);

	if (rc)

		return -EFAULT;



	return 0;

}



static int mctp_ioctl_alloctag(struct mctp_sock *msk, bool tagv2,

			       unsigned long arg)

{

	struct net *net = sock_net(&msk->sk);

	struct mctp_sk_key *key = NULL;

	struct mctp_ioc_tag_ctl ctl;

	struct mctp_ioc_tag_ctl2 ctl;

	unsigned long flags;

	u8 tag;

	int rc;



	if (copy_from_user(&ctl, (void __user *)arg, sizeof(ctl)))

		return -EFAULT;

	rc = mctp_ioctl_tag_copy_from_user(arg, &ctl, tagv2);

	if (rc)

		return rc;



	if (ctl.tag)

		return -EINVAL;



	if (ctl.flags)

		return -EINVAL;



	key = mctp_alloc_local_tag(msk, MCTP_INITIAL_DEFAULT_NET,

				   MCTP_ADDR_ANY, ctl.peer_addr, true, &tag);

	key = mctp_alloc_local_tag(msk, ctl.net, MCTP_ADDR_ANY,

				   ctl.peer_addr, true, &tag);

	if (IS_ERR(key))

		return PTR_ERR(key);



	ctl.tag = tag | MCTP_TAG_OWNER | MCTP_TAG_PREALLOC;

	if (copy_to_user((void __user *)arg, &ctl, sizeof(ctl))) {

	rc = mctp_ioctl_tag_copy_to_user(arg, &ctl, tagv2);

	if (rc) {

		unsigned long fl2;

		/* Unwind our key allocation: the keys list lock needs to be

		 * taken before the individual key locks, and we need a valid
@@ -385,28 +457,27 @@ static int mctp_ioctl_alloctag(struct mctp_sock *msk, unsigned long arg) 
		__mctp_key_remove(key, net, fl2, MCTP_TRACE_KEY_DROPPED);

		mctp_key_unref(key);

		spin_unlock_irqrestore(&net->mctp.keys_lock, flags);

		return -EFAULT;

		return rc;

	}



	mctp_key_unref(key);

	return 0;

}



static int mctp_ioctl_droptag(struct mctp_sock *msk, unsigned long arg)

static int mctp_ioctl_droptag(struct mctp_sock *msk, bool tagv2,

			      unsigned long arg)

{

	struct net *net = sock_net(&msk->sk);

	struct mctp_ioc_tag_ctl ctl;

	struct mctp_ioc_tag_ctl2 ctl;

	unsigned long flags, fl2;

	struct mctp_sk_key *key;

	struct hlist_node *tmp;

	int rc;

	u8 tag;



	if (copy_from_user(&ctl, (void __user *)arg, sizeof(ctl)))

		return -EFAULT;



	if (ctl.flags)

		return -EINVAL;

	rc = mctp_ioctl_tag_copy_from_user(arg, &ctl, tagv2);

	if (rc)

		return rc;



	/* Must be a local tag, TO set, preallocated */

	if ((ctl.tag & ~MCTP_TAG_MASK) != (MCTP_TAG_OWNER | MCTP_TAG_PREALLOC))
@@ -422,6 +493,7 @@ static int mctp_ioctl_droptag(struct mctp_sock *msk, unsigned long arg) 
		 */

		spin_lock_irqsave(&key->lock, fl2);

		if (key->manual_alloc &&

		    ctl.net == key->net &&

		    ctl.peer_addr == key->peer_addr &&

		    tag == key->tag) {

			__mctp_key_remove(key, net, fl2,
@@ -439,12 +511,17 @@ static int mctp_ioctl_droptag(struct mctp_sock *msk, unsigned long arg) 
static int mctp_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)

{

	struct mctp_sock *msk = container_of(sock->sk, struct mctp_sock, sk);

	bool tagv2 = false;



	switch (cmd) {

	case SIOCMCTPALLOCTAG2:

	case SIOCMCTPALLOCTAG:

		return mctp_ioctl_alloctag(msk, arg);

		tagv2 = cmd == SIOCMCTPALLOCTAG2;

		return mctp_ioctl_alloctag(msk, tagv2, arg);

	case SIOCMCTPDROPTAG:

		return mctp_ioctl_droptag(msk, arg);

	case SIOCMCTPDROPTAG2:

		tagv2 = cmd == SIOCMCTPDROPTAG2;

		return mctp_ioctl_droptag(msk, tagv2, arg);

	}



	return -EINVAL;