/*
 *	SNAP data link layer. Derived from 802.2
 *
 *		Alan Cox <alan@lxorguk.ukuu.org.uk>,
 *		from the 802.2 layer by Greg Page.
 *		Merged in additions from Greg Page's psnap.c.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/datalink.h>
#include <net/llc.h>
#include <net/psnap.h>
#include <linux/mm.h>
#include <linux/in.h>
#include <linux/init.h>
#include <linux/rculist.h>

static LIST_HEAD(snap_list);
static DEFINE_SPINLOCK(snap_lock);
static struct llc_sap *snap_sap;

/*
 *	Find a snap client by matching the 5 bytes.
 */
static struct datalink_proto *find_snap_client(const unsigned char *desc)
{
	struct datalink_proto *proto = NULL, *p;

	list_for_each_entry_rcu(p, &snap_list, node) {
		if (!memcmp(p->type, desc, 5)) {
			proto = p;
			break;
		}
	}
	return proto;
}

/*
 *	A SNAP packet has arrived
 */
static int snap_rcv(struct sk_buff *skb, struct net_device *dev,
		    struct packet_type *pt, struct net_device *orig_dev)
{
	int rc = 1;
	struct datalink_proto *proto;
	static struct packet_type snap_packet_type = {
		.type = cpu_to_be16(ETH_P_SNAP),
	};

	if (unlikely(!pskb_may_pull(skb, 5)))
		goto drop;

	rcu_read_lock();
	proto = find_snap_client(skb_transport_header(skb));
	if (proto) {
		/* Pass the frame on. */
		skb->transport_header += 5;
		skb_pull_rcsum(skb, 5);
		rc = proto->rcvfunc(skb, dev, &snap_packet_type, orig_dev);
	}
	rcu_read_unlock();

	if (unlikely(!proto))
		goto drop;

out:
	return rc;

drop:
	kfree_skb(skb);
	goto out;
}

/*
 *	Put a SNAP header on a frame and pass to 802.2
 */
static int snap_request(struct datalink_proto *dl,
			struct sk_buff *skb, u8 *dest)
{
	memcpy(skb_push(skb, 5), dl->type, 5);
	llc_build_and_send_ui_pkt(snap_sap, skb, dest, snap_sap->laddr.lsap);
	return 0;
}

/*
 *	Set up the SNAP layer
 */
EXPORT_SYMBOL(register_snap_client);
EXPORT_SYMBOL(unregister_snap_client);

static const char snap_err_msg[] __initconst =
	KERN_CRIT "SNAP - unable to register with 802.2\n";

static int __init snap_init(void)
{
	snap_sap = llc_sap_open(0xAA, snap_rcv);
	if (!snap_sap) {
		printk(snap_err_msg);
		return -EBUSY;
	}

	return 0;
}

module_init(snap_init);

static void __exit snap_exit(void)
{
	llc_sap_put(snap_sap);
}

module_exit(snap_exit);


/*
 *	Register SNAP clients. We don't yet use this for IP.
 */
struct datalink_proto *register_snap_client(const unsigned char *desc,
					    int (*rcvfunc)(struct sk_buff *,
							   struct net_device *,
							   struct packet_type *,
							   struct net_device *))
{
	struct datalink_proto *proto = NULL;

	spin_lock_bh(&snap_lock);

	if (find_snap_client(desc))
		goto out;

	proto = kmalloc(sizeof(*proto), GFP_ATOMIC);
	if (proto) {
		memcpy(proto->type, desc, 5);
		proto->rcvfunc		= rcvfunc;
		proto->header_length	= 5 + 3; /* snap + 802.2 */
		proto->request		= snap_request;
		list_add_rcu(&proto->node, &snap_list);
	}
out:
	spin_unlock_bh(&snap_lock);

	return proto;
}

/*
 *	Unregister SNAP clients. Protocols no longer want to play with us ...
 */
void unregister_snap_client(struct datalink_proto *proto)
{
	spin_lock_bh(&snap_lock);
	list_del_rcu(&proto->node);
	spin_unlock_bh(&snap_lock);

	synchronize_net();

	kfree(proto);
}

MODULE_LICENSE("GPL");
'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Bhumika Goyal &lt;bhumirks@gmail.com&gt;</td><td class='right'>2017-01-25 00:54:07 +0530</td></tr>
<tr><th>committer</th><td>Dan Williams &lt;dan.j.williams@intel.com&gt;</td><td class='right'>2017-01-31 18:16:30 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/sctp/socket.c?id=970d14e3989160ee9e97c7d75ecbc893fd29dab9'>970d14e3989160ee9e97c7d75ecbc893fd29dab9</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/sctp/socket.c?id=970d14e3989160ee9e97c7d75ecbc893fd29dab9'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=970d14e3989160ee9e97c7d75ecbc893fd29dab9'>4a731cac4efedb17f86a912ec56c151d26792abe</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/sctp/socket.c?id=970d14e3989160ee9e97c7d75ecbc893fd29dab9'>net/sctp/socket.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/sctp/socket.c?id=7a308bb3016f57e5be11a677d15b821536419d36'>7a308bb3016f57e5be11a677d15b821536419d36</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/sctp/socket.c?id=970d14e3989160ee9e97c7d75ecbc893fd29dab9&amp;id2=7a308bb3016f57e5be11a677d15b821536419d36'>diff</a>)</td></tr></table>
<div class='commit-subject'>nvdimm: constify device_type structures</div><div class='commit-msg'>Declare device_type structure as const as it is only stored in the
type field of a device structure. This field is of type const, so add
const to declaration of device_type structure.

File size before:
  text	   data	    bss	    dec	    hex	filename
  19278	   3199	     16	  22493	   57dd	nvdimm/namespace_devs.o

File size after:
  text	   data	    bss	    dec	    hex	filename
  19929	   3160	     16	  23105	   5a41	nvdimm/namespace_devs.o

Signed-off-by: Bhumika Goyal &lt;bhumirks@gmail.com&gt;
Signed-off-by: Dan Williams &lt;dan.j.williams@intel.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=970d14e3989160ee9e97c7d75ecbc893fd29dab9'>Diffstat</a> (limited to 'net/sctp/socket.c')</div><table summary='diffstat' class='diffstat'>