xref: /kernel/linux/linux-5.10/net/802/fc.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * NET3:	Fibre Channel device handling subroutines
4 *
5 *		Vineet Abraham <vma@iol.unh.edu>
6 *		v 1.0 03/22/99
7 */
8
9#include <linux/uaccess.h>
10#include <linux/types.h>
11#include <linux/kernel.h>
12#include <linux/string.h>
13#include <linux/mm.h>
14#include <linux/socket.h>
15#include <linux/in.h>
16#include <linux/inet.h>
17#include <linux/netdevice.h>
18#include <linux/fcdevice.h>
19#include <linux/skbuff.h>
20#include <linux/errno.h>
21#include <linux/timer.h>
22#include <linux/net.h>
23#include <linux/proc_fs.h>
24#include <linux/init.h>
25#include <linux/export.h>
26#include <net/arp.h>
27
28/*
29 *	Put the headers on a Fibre Channel packet.
30 */
31
32static int fc_header(struct sk_buff *skb, struct net_device *dev,
33		     unsigned short type,
34		     const void *daddr, const void *saddr, unsigned int len)
35{
36	struct fch_hdr *fch;
37	int hdr_len;
38
39	/*
40	 * Add the 802.2 SNAP header if IP as the IPv4 code calls
41	 * dev->hard_header directly.
42	 */
43	if (type == ETH_P_IP || type == ETH_P_ARP)
44	{
45		struct fcllc *fcllc;
46
47		hdr_len = sizeof(struct fch_hdr) + sizeof(struct fcllc);
48		fch = skb_push(skb, hdr_len);
49		fcllc = (struct fcllc *)(fch+1);
50		fcllc->dsap = fcllc->ssap = EXTENDED_SAP;
51		fcllc->llc = UI_CMD;
52		fcllc->protid[0] = fcllc->protid[1] = fcllc->protid[2] = 0x00;
53		fcllc->ethertype = htons(type);
54	}
55	else
56	{
57		hdr_len = sizeof(struct fch_hdr);
58		fch = skb_push(skb, hdr_len);
59	}
60
61	if(saddr)
62		memcpy(fch->saddr,saddr,dev->addr_len);
63	else
64		memcpy(fch->saddr,dev->dev_addr,dev->addr_len);
65
66	if(daddr)
67	{
68		memcpy(fch->daddr,daddr,dev->addr_len);
69		return hdr_len;
70	}
71	return -hdr_len;
72}
73
74static const struct header_ops fc_header_ops = {
75	.create	 = fc_header,
76};
77
78static void fc_setup(struct net_device *dev)
79{
80	dev->header_ops		= &fc_header_ops;
81	dev->type		= ARPHRD_IEEE802;
82	dev->hard_header_len	= FC_HLEN;
83	dev->mtu		= 2024;
84	dev->addr_len		= FC_ALEN;
85	dev->tx_queue_len	= 100; /* Long queues on fc */
86	dev->flags		= IFF_BROADCAST;
87
88	memset(dev->broadcast, 0xFF, FC_ALEN);
89}
90
91/**
92 * alloc_fcdev - Register fibre channel device
93 * @sizeof_priv: Size of additional driver-private structure to be allocated
94 *	for this fibre channel device
95 *
96 * Fill in the fields of the device structure with fibre channel-generic values.
97 *
98 * Constructs a new net device, complete with a private data area of
99 * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
100 * this private data area.
101 */
102struct net_device *alloc_fcdev(int sizeof_priv)
103{
104	return alloc_netdev(sizeof_priv, "fc%d", NET_NAME_UNKNOWN, fc_setup);
105}
106EXPORT_SYMBOL(alloc_fcdev);
107