xref: /linux/net/802/fc.c (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
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 <net/arp.h>
31 
32 /*
33  *	Put the headers on a Fibre Channel packet.
34  */
35 
36 static int fc_header(struct sk_buff *skb, struct net_device *dev,
37 		     unsigned short type,
38 		     const void *daddr, const void *saddr, unsigned len)
39 {
40 	struct fch_hdr *fch;
41 	int hdr_len;
42 
43 	/*
44 	 * Add the 802.2 SNAP header if IP as the IPv4 code calls
45 	 * dev->hard_header directly.
46 	 */
47 	if (type == ETH_P_IP || type == ETH_P_ARP)
48 	{
49 		struct fcllc *fcllc;
50 
51 		hdr_len = sizeof(struct fch_hdr) + sizeof(struct fcllc);
52 		fch = (struct fch_hdr *)skb_push(skb, hdr_len);
53 		fcllc = (struct fcllc *)(fch+1);
54 		fcllc->dsap = fcllc->ssap = EXTENDED_SAP;
55 		fcllc->llc = UI_CMD;
56 		fcllc->protid[0] = fcllc->protid[1] = fcllc->protid[2] = 0x00;
57 		fcllc->ethertype = htons(type);
58 	}
59 	else
60 	{
61 		hdr_len = sizeof(struct fch_hdr);
62 		fch = (struct fch_hdr *)skb_push(skb, hdr_len);
63 	}
64 
65 	if(saddr)
66 		memcpy(fch->saddr,saddr,dev->addr_len);
67 	else
68 		memcpy(fch->saddr,dev->dev_addr,dev->addr_len);
69 
70 	if(daddr)
71 	{
72 		memcpy(fch->daddr,daddr,dev->addr_len);
73 		return(hdr_len);
74 	}
75 	return -hdr_len;
76 }
77 
78 /*
79  *	A neighbour discovery of some species (eg arp) has completed. We
80  *	can now send the packet.
81  */
82 
83 static int fc_rebuild_header(struct sk_buff *skb)
84 {
85 #ifdef CONFIG_INET
86 	struct fch_hdr *fch=(struct fch_hdr *)skb->data;
87 	struct fcllc *fcllc=(struct fcllc *)(skb->data+sizeof(struct fch_hdr));
88 	if(fcllc->ethertype != htons(ETH_P_IP)) {
89 		printk("fc_rebuild_header: Don't know how to resolve type %04X addresses ?\n", ntohs(fcllc->ethertype));
90 		return 0;
91 	}
92 	return arp_find(fch->daddr, skb);
93 #else
94 	return 0;
95 #endif
96 }
97 
98 static const struct header_ops fc_header_ops = {
99 	.create	 = fc_header,
100 	.rebuild = fc_rebuild_header,
101 };
102 
103 static void fc_setup(struct net_device *dev)
104 {
105 	dev->header_ops		= &fc_header_ops;
106 	dev->type		= ARPHRD_IEEE802;
107 	dev->hard_header_len	= FC_HLEN;
108 	dev->mtu		= 2024;
109 	dev->addr_len		= FC_ALEN;
110 	dev->tx_queue_len	= 100; /* Long queues on fc */
111 	dev->flags		= IFF_BROADCAST;
112 
113 	memset(dev->broadcast, 0xFF, FC_ALEN);
114 }
115 
116 /**
117  * alloc_fcdev - Register fibre channel device
118  * @sizeof_priv: Size of additional driver-private structure to be allocated
119  *	for this fibre channel device
120  *
121  * Fill in the fields of the device structure with fibre channel-generic values.
122  *
123  * Constructs a new net device, complete with a private data area of
124  * size @sizeof_priv.  A 32-byte (not bit) alignment is enforced for
125  * this private data area.
126  */
127 struct net_device *alloc_fcdev(int sizeof_priv)
128 {
129 	return alloc_netdev(sizeof_priv, "fc%d", fc_setup);
130 }
131 EXPORT_SYMBOL(alloc_fcdev);
132