tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * HIPPI-type device handling.
7 *
8 * Version: @(#)hippi.c 1.0.0 05/29/97
9 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Mark Evans, <evansmp@uhura.aston.ac.uk>
13 * Florian La Roche, <rzsfl@rz.uni-sb.de>
14 * Alan Cox, <gw4pts@gw4pts.ampr.org>
15 * Jes Sorensen, <Jes.Sorensen@cern.ch>
16 *
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version
20 * 2 of the License, or (at your option) any later version.
21 */
22
23#include <linux/module.h>
24#include <linux/types.h>
25#include <linux/kernel.h>
26#include <linux/sched.h>
27#include <linux/string.h>
28#include <linux/mm.h>
29#include <linux/socket.h>
30#include <linux/in.h>
31#include <linux/inet.h>
32#include <linux/netdevice.h>
33#include <linux/hippidevice.h>
34#include <linux/skbuff.h>
35#include <linux/errno.h>
36#include <net/arp.h>
37#include <net/sock.h>
38#include <asm/uaccess.h>
39#include <asm/checksum.h>
40#include <asm/system.h>
41
42/*
43 * Create the HIPPI MAC header for an arbitrary protocol layer
44 *
45 * saddr=NULL means use device source address
46 * daddr=NULL means leave destination address (eg unresolved arp)
47 */
48
49static int hippi_header(struct sk_buff *skb, struct net_device *dev,
50 unsigned short type, void *daddr, void *saddr,
51 unsigned len)
52{
53 struct hippi_hdr *hip = (struct hippi_hdr *)skb_push(skb, HIPPI_HLEN);
54 struct hippi_cb *hcb = (struct hippi_cb *) skb->cb;
55
56 if (!len){
57 len = skb->len - HIPPI_HLEN;
58 printk("hippi_header(): length not supplied\n");
59 }
60
61 /*
62 * Due to the stupidity of the little endian byte-order we
63 * have to set the fp field this way.
64 */
65 hip->fp.fixed = __constant_htonl(0x04800018);
66 hip->fp.d2_size = htonl(len + 8);
67 hip->le.fc = 0;
68 hip->le.double_wide = 0; /* only HIPPI 800 for the time being */
69 hip->le.message_type = 0; /* Data PDU */
70
71 hip->le.dest_addr_type = 2; /* 12 bit SC address */
72 hip->le.src_addr_type = 2; /* 12 bit SC address */
73
74 memcpy(hip->le.src_switch_addr, dev->dev_addr + 3, 3);
75 memset(&hip->le.reserved, 0, 16);
76
77 hip->snap.dsap = HIPPI_EXTENDED_SAP;
78 hip->snap.ssap = HIPPI_EXTENDED_SAP;
79 hip->snap.ctrl = HIPPI_UI_CMD;
80 hip->snap.oui[0] = 0x00;
81 hip->snap.oui[1] = 0x00;
82 hip->snap.oui[2] = 0x00;
83 hip->snap.ethertype = htons(type);
84
85 if (daddr)
86 {
87 memcpy(hip->le.dest_switch_addr, daddr + 3, 3);
88 memcpy(&hcb->ifield, daddr + 2, 4);
89 return HIPPI_HLEN;
90 }
91 hcb->ifield = 0;
92 return -((int)HIPPI_HLEN);
93}
94
95
96/*
97 * Rebuild the HIPPI MAC header. This is called after an ARP has
98 * completed on this sk_buff. We now let ARP fill in the other fields.
99 */
100
101static int hippi_rebuild_header(struct sk_buff *skb)
102{
103 struct hippi_hdr *hip = (struct hippi_hdr *)skb->data;
104
105 /*
106 * Only IP is currently supported
107 */
108
109 if(hip->snap.ethertype != __constant_htons(ETH_P_IP))
110 {
111 printk(KERN_DEBUG "%s: unable to resolve type %X addresses.\n",skb->dev->name,ntohs(hip->snap.ethertype));
112 return 0;
113 }
114
115 /*
116 * We don't support dynamic ARP on HIPPI, but we use the ARP
117 * static ARP tables to hold the I-FIELDs.
118 */
119 return arp_find(hip->le.daddr, skb);
120}
121
122
123/*
124 * Determine the packet's protocol ID.
125 */
126
127__be16 hippi_type_trans(struct sk_buff *skb, struct net_device *dev)
128{
129 struct hippi_hdr *hip;
130
131 hip = (struct hippi_hdr *) skb->data;
132
133 /*
134 * This is actually wrong ... question is if we really should
135 * set the raw address here.
136 */
137 skb->mac.raw = skb->data;
138 skb_pull(skb, HIPPI_HLEN);
139
140 /*
141 * No fancy promisc stuff here now.
142 */
143
144 return hip->snap.ethertype;
145}
146
147EXPORT_SYMBOL(hippi_type_trans);
148
149static int hippi_change_mtu(struct net_device *dev, int new_mtu)
150{
151 /*
152 * HIPPI's got these nice large MTUs.
153 */
154 if ((new_mtu < 68) || (new_mtu > 65280))
155 return -EINVAL;
156 dev->mtu = new_mtu;
157 return(0);
158}
159
160/*
161 * For HIPPI we will actually use the lower 4 bytes of the hardware
162 * address as the I-FIELD rather than the actual hardware address.
163 */
164static int hippi_mac_addr(struct net_device *dev, void *p)
165{
166 struct sockaddr *addr = p;
167 if (netif_running(dev))
168 return -EBUSY;
169 memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
170 return 0;
171}
172
173static int hippi_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
174{
175 /* Never send broadcast/multicast ARP messages */
176 p->mcast_probes = 0;
177
178 /* In IPv6 unicast probes are valid even on NBMA,
179 * because they are encapsulated in normal IPv6 protocol.
180 * Should be a generic flag.
181 */
182 if (p->tbl->family != AF_INET6)
183 p->ucast_probes = 0;
184 return 0;
185}
186
187static void hippi_setup(struct net_device *dev)
188{
189 dev->set_multicast_list = NULL;
190 dev->change_mtu = hippi_change_mtu;
191 dev->hard_header = hippi_header;
192 dev->rebuild_header = hippi_rebuild_header;
193 dev->set_mac_address = hippi_mac_addr;
194 dev->hard_header_parse = NULL;
195 dev->hard_header_cache = NULL;
196 dev->header_cache_update = NULL;
197 dev->neigh_setup = hippi_neigh_setup_dev;
198
199 /*
200 * We don't support HIPPI `ARP' for the time being, and probably
201 * never will unless someone else implements it. However we
202 * still need a fake ARPHRD to make ifconfig and friends play ball.
203 */
204 dev->type = ARPHRD_HIPPI;
205 dev->hard_header_len = HIPPI_HLEN;
206 dev->mtu = 65280;
207 dev->addr_len = HIPPI_ALEN;
208 dev->tx_queue_len = 25 /* 5 */;
209 memset(dev->broadcast, 0xFF, HIPPI_ALEN);
210
211
212 /*
213 * HIPPI doesn't support broadcast+multicast and we only use
214 * static ARP tables. ARP is disabled by hippi_neigh_setup_dev.
215 */
216 dev->flags = 0;
217}
218
219/**
220 * alloc_hippi_dev - Register HIPPI device
221 * @sizeof_priv: Size of additional driver-private structure to be allocated
222 * for this HIPPI device
223 *
224 * Fill in the fields of the device structure with HIPPI-generic values.
225 *
226 * Constructs a new net device, complete with a private data area of
227 * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for
228 * this private data area.
229 */
230
231struct net_device *alloc_hippi_dev(int sizeof_priv)
232{
233 return alloc_netdev(sizeof_priv, "hip%d", hippi_setup);
234}
235
236EXPORT_SYMBOL(alloc_hippi_dev);