1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 *
4 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
5 */
6 #include <linux/module.h>
7 #include <linux/proc_fs.h>
8 #include <linux/kernel.h>
9 #include <linux/interrupt.h>
10 #include <linux/fs.h>
11 #include <linux/types.h>
12 #include <linux/sysctl.h>
13 #include <linux/string.h>
14 #include <linux/socket.h>
15 #include <linux/errno.h>
16 #include <linux/fcntl.h>
17 #include <linux/in.h>
18 #include <linux/if_ether.h> /* For the statistics structure. */
19 #include <linux/slab.h>
20 #include <linux/uaccess.h>
21
22 #include <asm/io.h>
23
24 #include <linux/inet.h>
25 #include <linux/netdevice.h>
26 #include <linux/etherdevice.h>
27 #include <linux/if_arp.h>
28 #include <linux/skbuff.h>
29
30 #include <net/ip.h>
31 #include <net/arp.h>
32
33 #include <net/ax25.h>
34 #include <net/netrom.h>
35
36 /*
37 * Only allow IP over NET/ROM frames through if the netrom device is up.
38 */
39
40 int nr_rx_ip(struct sk_buff *skb, struct net_device *dev)
41 {
42 struct net_device_stats *stats = &dev->stats;
43
44 if (!netif_running(dev)) {
45 stats->rx_dropped++;
46 return 0;
47 }
48
49 stats->rx_packets++;
50 stats->rx_bytes += skb->len;
51
52 skb->protocol = htons(ETH_P_IP);
53
54 /* Spoof incoming device */
55 skb->dev = dev;
56 skb->mac_header = skb->network_header;
57 skb_reset_network_header(skb);
58 skb->pkt_type = PACKET_HOST;
59
60 netif_rx(skb);
61
62 return 1;
63 }
64
65 static int nr_header(struct sk_buff *skb, struct net_device *dev,
66 unsigned short type,
67 const void *daddr, const void *saddr, unsigned int len)
68 {
69 unsigned char *buff = skb_push(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
70
71 memcpy(buff, (saddr != NULL) ? saddr : dev->dev_addr, dev->addr_len);
72 buff[6] &= ~AX25_CBIT;
73 buff[6] &= ~AX25_EBIT;
74 buff[6] |= AX25_SSSID_SPARE;
75 buff += AX25_ADDR_LEN;
76
77 if (daddr != NULL)
78 memcpy(buff, daddr, dev->addr_len);
79 buff[6] &= ~AX25_CBIT;
80 buff[6] |= AX25_EBIT;
81 buff[6] |= AX25_SSSID_SPARE;
82 buff += AX25_ADDR_LEN;
83
84 *buff++ = READ_ONCE(sysctl_netrom_network_ttl_initialiser);
85
86 *buff++ = NR_PROTO_IP;
87 *buff++ = NR_PROTO_IP;
88 *buff++ = 0;
89 *buff++ = 0;
90 *buff++ = NR_PROTOEXT;
91
92 if (daddr != NULL)
93 return 37;
94
95 return -37;
96 }
97
98 static int __must_check nr_set_mac_address(struct net_device *dev, void *addr)
99 {
100 struct sockaddr *sa = addr;
101 int err;
102
103 if (!memcmp(dev->dev_addr, sa->sa_data, dev->addr_len))
104 return 0;
105
106 if (dev->flags & IFF_UP) {
107 err = ax25_listen_register((ax25_address *)sa->sa_data, NULL);
108 if (err)
109 return err;
110
111 ax25_listen_release((const ax25_address *)dev->dev_addr, NULL);
112 }
113
114 dev_addr_set(dev, sa->sa_data);
115
116 return 0;
117 }
118
119 static int nr_open(struct net_device *dev)
120 {
121 int err;
122
123 err = ax25_listen_register((const ax25_address *)dev->dev_addr, NULL);
124 if (err)
125 return err;
126
127 netif_start_queue(dev);
128
129 return 0;
130 }
131
132 static int nr_close(struct net_device *dev)
133 {
134 ax25_listen_release((const ax25_address *)dev->dev_addr, NULL);
135 netif_stop_queue(dev);
136 return 0;
137 }
138
139 static netdev_tx_t nr_xmit(struct sk_buff *skb, struct net_device *dev)
140 {
141 struct net_device_stats *stats = &dev->stats;
142 unsigned int len = skb->len;
143
144 if (!nr_route_frame(skb, NULL)) {
145 kfree_skb(skb);
146 stats->tx_errors++;
147 return NETDEV_TX_OK;
148 }
149
150 stats->tx_packets++;
151 stats->tx_bytes += len;
152
153 return NETDEV_TX_OK;
154 }
155
156 static const struct header_ops nr_header_ops = {
157 .create = nr_header,
158 };
159
160 static const struct net_device_ops nr_netdev_ops = {
161 .ndo_open = nr_open,
162 .ndo_stop = nr_close,
163 .ndo_start_xmit = nr_xmit,
164 .ndo_set_mac_address = nr_set_mac_address,
165 };
166
167 void nr_setup(struct net_device *dev)
168 {
169 dev->mtu = NR_MAX_PACKET_SIZE;
170 dev->netdev_ops = &nr_netdev_ops;
171 dev->header_ops = &nr_header_ops;
172 dev->hard_header_len = NR_NETWORK_LEN + NR_TRANSPORT_LEN;
173 dev->addr_len = AX25_ADDR_LEN;
174 dev->type = ARPHRD_NETROM;
175
176 /* New-style flags. */
177 dev->flags = IFF_NOARP;
178 }
179
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