1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * HIPPI-type device handling.
8 *
9 * Version: @(#)hippi.c 1.0.0 05/29/97
10 *
11 * Authors: Ross Biro
12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13 * Mark Evans, <evansmp@uhura.aston.ac.uk>
14 * Florian La Roche, <rzsfl@rz.uni-sb.de>
15 * Alan Cox, <gw4pts@gw4pts.ampr.org>
16 * Jes Sorensen, <Jes.Sorensen@cern.ch>
17 */
18
19 #include <linux/module.h>
20 #include <linux/types.h>
21 #include <linux/kernel.h>
22 #include <linux/string.h>
23 #include <linux/mm.h>
24 #include <linux/socket.h>
25 #include <linux/in.h>
26 #include <linux/inet.h>
27 #include <linux/netdevice.h>
28 #include <linux/hippidevice.h>
29 #include <linux/skbuff.h>
30 #include <linux/errno.h>
31 #include <net/arp.h>
32 #include <net/sock.h>
33 #include <linux/uaccess.h>
34
35 /*
36 * Create the HIPPI MAC header for an arbitrary protocol layer
37 *
38 * saddr=NULL means use device source address
39 * daddr=NULL means leave destination address (eg unresolved arp)
40 */
41
42 static int hippi_header(struct sk_buff *skb, struct net_device *dev,
43 unsigned short type,
44 const void *daddr, const void *saddr, unsigned int len)
45 {
46 struct hippi_hdr *hip = skb_push(skb, HIPPI_HLEN);
47 struct hippi_cb *hcb = (struct hippi_cb *) skb->cb;
48
49 if (!len){
50 len = skb->len - HIPPI_HLEN;
51 printk("hippi_header(): length not supplied\n");
52 }
53
54 /*
55 * Due to the stupidity of the little endian byte-order we
56 * have to set the fp field this way.
57 */
58 hip->fp.fixed = htonl(0x04800018);
59 hip->fp.d2_size = htonl(len + 8);
60 hip->le.fc = 0;
61 hip->le.double_wide = 0; /* only HIPPI 800 for the time being */
62 hip->le.message_type = 0; /* Data PDU */
63
64 hip->le.dest_addr_type = 2; /* 12 bit SC address */
65 hip->le.src_addr_type = 2; /* 12 bit SC address */
66
67 memcpy(hip->le.src_switch_addr, dev->dev_addr + 3, 3);
68 memset(&hip->le.reserved, 0, 16);
69
70 hip->snap.dsap = HIPPI_EXTENDED_SAP;
71 hip->snap.ssap = HIPPI_EXTENDED_SAP;
72 hip->snap.ctrl = HIPPI_UI_CMD;
73 hip->snap.oui[0] = 0x00;
74 hip->snap.oui[1] = 0x00;
75 hip->snap.oui[2] = 0x00;
76 hip->snap.ethertype = htons(type);
77
78 if (daddr)
79 {
80 memcpy(hip->le.dest_switch_addr, daddr + 3, 3);
81 memcpy(&hcb->ifield, daddr + 2, 4);
82 return HIPPI_HLEN;
83 }
84 hcb->ifield = 0;
85 return -((int)HIPPI_HLEN);
86 }
87
88
89 /*
90 * Determine the packet's protocol ID.
91 */
92
93 __be16 hippi_type_trans(struct sk_buff *skb, struct net_device *dev)
94 {
95 struct hippi_hdr *hip;
96
97 /*
98 * This is actually wrong ... question is if we really should
99 * set the raw address here.
100 */
101 skb->dev = dev;
102 skb_reset_mac_header(skb);
103 hip = (struct hippi_hdr *)skb_mac_header(skb);
104 skb_pull(skb, HIPPI_HLEN);
105
106 /*
107 * No fancy promisc stuff here now.
108 */
109
110 return hip->snap.ethertype;
111 }
112
113 EXPORT_SYMBOL(hippi_type_trans);
114
115 /*
116 * For HIPPI we will actually use the lower 4 bytes of the hardware
117 * address as the I-FIELD rather than the actual hardware address.
118 */
119 int hippi_mac_addr(struct net_device *dev, void *p)
120 {
121 struct sockaddr *addr = p;
122 if (netif_running(dev))
123 return -EBUSY;
124 memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
125 return 0;
126 }
127 EXPORT_SYMBOL(hippi_mac_addr);
128
129 int hippi_neigh_setup_dev(struct net_device *dev, struct neigh_parms *p)
130 {
131 /* Never send broadcast/multicast ARP messages */
132 NEIGH_VAR_INIT(p, MCAST_PROBES, 0);
133
134 /* In IPv6 unicast probes are valid even on NBMA,
135 * because they are encapsulated in normal IPv6 protocol.
136 * Should be a generic flag.
137 */
138 if (p->tbl->family != AF_INET6)
139 NEIGH_VAR_INIT(p, UCAST_PROBES, 0);
140 return 0;
141 }
142 EXPORT_SYMBOL(hippi_neigh_setup_dev);
143
144 static const struct header_ops hippi_header_ops = {
145 .create = hippi_header,
146 };
147
148
149 static void hippi_setup(struct net_device *dev)
150 {
151 dev->header_ops = &hippi_header_ops;
152
153 /*
154 * We don't support HIPPI `ARP' for the time being, and probably
155 * never will unless someone else implements it. However we
156 * still need a fake ARPHRD to make ifconfig and friends play ball.
157 */
158 dev->type = ARPHRD_HIPPI;
159 dev->hard_header_len = HIPPI_HLEN;
160 dev->mtu = 65280;
161 dev->min_mtu = 68;
162 dev->max_mtu = 65280;
163 dev->addr_len = HIPPI_ALEN;
164 dev->tx_queue_len = 25 /* 5 */;
165 memset(dev->broadcast, 0xFF, HIPPI_ALEN);
166
167
168 /*
169 * HIPPI doesn't support broadcast+multicast and we only use
170 * static ARP tables. ARP is disabled by hippi_neigh_setup_dev.
171 */
172 dev->flags = 0;
173 }
174
175 /**
176 * alloc_hippi_dev - Register HIPPI device
177 * @sizeof_priv: Size of additional driver-private structure to be allocated
178 * for this HIPPI device
179 *
180 * Fill in the fields of the device structure with HIPPI-generic values.
181 *
182 * Constructs a new net device, complete with a private data area of
183 * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for
184 * this private data area.
185 */
186
187 struct net_device *alloc_hippi_dev(int sizeof_priv)
188 {
189 return alloc_netdev(sizeof_priv, "hip%d", NET_NAME_UNKNOWN,
190 hippi_setup);
191 }
192
193 EXPORT_SYMBOL(alloc_hippi_dev);