xref: /linux/net/802/fc.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
1 /*
2  * NET3:	Fibre Channel device handling subroutines
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  *		Vineet Abraham <vma@iol.unh.edu>
10  *		v 1.0 03/22/99
11  */
12 
13 #include <asm/uaccess.h>
14 #include <asm/system.h>
15 #include <linux/types.h>
16 #include <linux/kernel.h>
17 #include <linux/string.h>
18 #include <linux/mm.h>
19 #include <linux/socket.h>
20 #include <linux/in.h>
21 #include <linux/inet.h>
22 #include <linux/netdevice.h>
23 #include <linux/fcdevice.h>
24 #include <linux/skbuff.h>
25 #include <linux/errno.h>
26 #include <linux/timer.h>
27 #include <linux/net.h>
28 #include <linux/proc_fs.h>
29 #include <linux/init.h>
30 #include <linux/export.h>
31 #include <net/arp.h>
32 
33 /*
34  *	Put the headers on a Fibre Channel packet.
35  */
36 
37 static int fc_header(struct sk_buff *skb, struct net_device *dev,
38 		     unsigned short type,
39 		     const void *daddr, const void *saddr, unsigned len)
40 {
41 	struct fch_hdr *fch;
42 	int hdr_len;
43 
44 	/*
45 	 * Add the 802.2 SNAP header if IP as the IPv4 code calls
46 	 * dev->hard_header directly.
47 	 */
48 	if (type == ETH_P_IP || type == ETH_P_ARP)
49 	{
50 		struct fcllc *fcllc;
51 
52 		hdr_len = sizeof(struct fch_hdr) + sizeof(struct fcllc);
53 		fch = (struct fch_hdr *)skb_push(skb, hdr_len);
54 		fcllc = (struct fcllc *)(fch+1);
55 		fcllc->dsap = fcllc->ssap = EXTENDED_SAP;
56 		fcllc->llc = UI_CMD;
57 		fcllc->protid[0] = fcllc->protid[1] = fcllc->protid[2] = 0x00;
58 		fcllc->ethertype = htons(type);
59 	}
60 	else
61 	{
62 		hdr_len = sizeof(struct fch_hdr);
63 		fch = (struct fch_hdr *)skb_push(skb, hdr_len);
64 	}
65 
66 	if(saddr)
67 		memcpy(fch->saddr,saddr,dev->addr_len);
68 	else
69 		memcpy(fch->saddr,dev->dev_addr,dev->addr_len);
70 
71 	if(daddr)
72 	{
73 		memcpy(fch->daddr,daddr,dev->addr_len);
74 		return hdr_len;
75 	}
76 	return -hdr_len;
77 }
78 
79 /*
80  *	A neighbour discovery of some species (eg arp) has completed. We
81  *	can now send the packet.
82  */
83 
84 static int fc_rebuild_header(struct sk_buff *skb)
85 {
86 #ifdef CONFIG_INET
87 	struct fch_hdr *fch=(struct fch_hdr *)skb->data;
88 	struct fcllc *fcllc=(struct fcllc *)(skb->data+sizeof(struct fch_hdr));
89 	if(fcllc->ethertype != htons(ETH_P_IP)) {
90 		printk("fc_rebuild_header: Don't know how to resolve type %04X addresses ?\n", ntohs(fcllc->ethertype));
91 		return 0;
92 	}
93 	return arp_find(fch->daddr, skb);
94 #else
95 	return 0;
96 #endif
97 }
98 
99 static const struct header_ops fc_header_ops = {
100 	.create	 = fc_header,
101 	.rebuild = fc_rebuild_header,
102 };
103 
104 static void fc_setup(struct net_device *dev)
105 {
106 	dev->header_ops		= &fc_header_ops;
107 	dev->type		= ARPHRD_IEEE802;
108 	dev->hard_header_len	= FC_HLEN;
109 	dev->mtu		= 2024;
110 	dev->addr_len		= FC_ALEN;
111 	dev->tx_queue_len	= 100; /* Long queues on fc */
112 	dev->flags		= IFF_BROADCAST;
113 
114 	memset(dev->broadcast, 0xFF, FC_ALEN);
115 }
116 
117 /**
118  * alloc_fcdev - Register fibre channel device
119  * @sizeof_priv: Size of additional driver-private structure to be allocated
120  *	for this fibre channel device
121  *
122  * Fill in the fields of the device structure with fibre channel-generic values.
123  *
124  * Constructs a new net device, complete with a private data area of
125  * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
126  * this private data area.
127  */
128 struct net_device *alloc_fcdev(int sizeof_priv)
129 {
130 	return alloc_netdev(sizeof_priv, "fc%d", fc_setup);
131 }
132 EXPORT_SYMBOL(alloc_fcdev);
133