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1da177e4 LT |
1 | /* |
2 | * Linux ARCnet driver - "raw mode" packet encapsulation (no soft headers) | |
3 | * | |
4 | * Written 1994-1999 by Avery Pennarun. | |
5 | * Derived from skeleton.c by Donald Becker. | |
6 | * | |
7 | * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com) | |
8 | * for sponsoring the further development of this driver. | |
9 | * | |
10 | * ********************** | |
11 | * | |
12 | * The original copyright of skeleton.c was as follows: | |
13 | * | |
14 | * skeleton.c Written 1993 by Donald Becker. | |
15 | * Copyright 1993 United States Government as represented by the | |
16 | * Director, National Security Agency. This software may only be used | |
17 | * and distributed according to the terms of the GNU General Public License as | |
18 | * modified by SRC, incorporated herein by reference. | |
19 | * | |
20 | * ********************** | |
21 | * | |
22 | * For more details, see drivers/net/arcnet.c | |
23 | * | |
24 | * ********************** | |
25 | */ | |
26 | ||
27 | #include <linux/module.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/if_arp.h> | |
30 | #include <net/arp.h> | |
31 | #include <linux/netdevice.h> | |
32 | #include <linux/skbuff.h> | |
33 | #include <linux/arcdevice.h> | |
34 | ||
35 | #define VERSION "arcnet: raw mode (`r') encapsulation support loaded.\n" | |
36 | ||
37 | ||
38 | static void rx(struct net_device *dev, int bufnum, | |
39 | struct archdr *pkthdr, int length); | |
40 | static int build_header(struct sk_buff *skb, struct net_device *dev, | |
41 | unsigned short type, uint8_t daddr); | |
42 | static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, | |
43 | int bufnum); | |
44 | ||
f03aa2d8 | 45 | static struct ArcProto rawmode_proto = |
1da177e4 LT |
46 | { |
47 | .suffix = 'r', | |
48 | .mtu = XMTU, | |
49 | .rx = rx, | |
50 | .build_header = build_header, | |
51 | .prepare_tx = prepare_tx, | |
52 | .continue_tx = NULL, | |
53 | .ack_tx = NULL | |
54 | }; | |
55 | ||
56 | ||
57 | static int __init arcnet_raw_init(void) | |
58 | { | |
59 | int count; | |
60 | ||
61 | printk(VERSION); | |
62 | ||
63 | for (count = 0; count < 256; count++) | |
64 | if (arc_proto_map[count] == arc_proto_default) | |
65 | arc_proto_map[count] = &rawmode_proto; | |
66 | ||
67 | /* for raw mode, we only set the bcast proto if there's no better one */ | |
68 | if (arc_bcast_proto == arc_proto_default) | |
69 | arc_bcast_proto = &rawmode_proto; | |
70 | ||
71 | arc_proto_default = &rawmode_proto; | |
72 | return 0; | |
73 | } | |
74 | ||
75 | static void __exit arcnet_raw_exit(void) | |
76 | { | |
77 | arcnet_unregister_proto(&rawmode_proto); | |
78 | } | |
79 | ||
80 | module_init(arcnet_raw_init); | |
81 | module_exit(arcnet_raw_exit); | |
82 | ||
83 | MODULE_LICENSE("GPL"); | |
84 | ||
85 | ||
86 | /* packet receiver */ | |
87 | static void rx(struct net_device *dev, int bufnum, | |
88 | struct archdr *pkthdr, int length) | |
89 | { | |
454d7c9b | 90 | struct arcnet_local *lp = netdev_priv(dev); |
1da177e4 LT |
91 | struct sk_buff *skb; |
92 | struct archdr *pkt = pkthdr; | |
93 | int ofs; | |
94 | ||
95 | BUGMSG(D_DURING, "it's a raw packet (length=%d)\n", length); | |
96 | ||
52edc17f | 97 | if (length > MTU) |
1da177e4 LT |
98 | ofs = 512 - length; |
99 | else | |
100 | ofs = 256 - length; | |
101 | ||
102 | skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC); | |
103 | if (skb == NULL) { | |
104 | BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n"); | |
5803c512 | 105 | dev->stats.rx_dropped++; |
1da177e4 LT |
106 | return; |
107 | } | |
108 | skb_put(skb, length + ARC_HDR_SIZE); | |
109 | skb->dev = dev; | |
110 | ||
111 | pkt = (struct archdr *) skb->data; | |
112 | ||
459a98ed | 113 | skb_reset_mac_header(skb); |
1da177e4 LT |
114 | skb_pull(skb, ARC_HDR_SIZE); |
115 | ||
116 | /* up to sizeof(pkt->soft) has already been copied from the card */ | |
117 | memcpy(pkt, pkthdr, sizeof(struct archdr)); | |
118 | if (length > sizeof(pkt->soft)) | |
119 | lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft), | |
120 | pkt->soft.raw + sizeof(pkt->soft), | |
121 | length - sizeof(pkt->soft)); | |
122 | ||
123 | BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx"); | |
124 | ||
09640e63 | 125 | skb->protocol = cpu_to_be16(ETH_P_ARCNET); |
1da177e4 LT |
126 | ; |
127 | netif_rx(skb); | |
1da177e4 LT |
128 | } |
129 | ||
130 | ||
131 | /* | |
132 | * Create the ARCnet hard/soft headers for raw mode. | |
133 | * There aren't any soft headers in raw mode - not even the protocol id. | |
134 | */ | |
135 | static int build_header(struct sk_buff *skb, struct net_device *dev, | |
136 | unsigned short type, uint8_t daddr) | |
137 | { | |
138 | int hdr_size = ARC_HDR_SIZE; | |
139 | struct archdr *pkt = (struct archdr *) skb_push(skb, hdr_size); | |
140 | ||
141 | /* | |
142 | * Set the source hardware address. | |
143 | * | |
144 | * This is pretty pointless for most purposes, but it can help in | |
145 | * debugging. ARCnet does not allow us to change the source address in | |
146 | * the actual packet sent) | |
147 | */ | |
148 | pkt->hard.source = *dev->dev_addr; | |
149 | ||
150 | /* see linux/net/ethernet/eth.c to see where I got the following */ | |
151 | ||
152 | if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) { | |
153 | /* | |
154 | * FIXME: fill in the last byte of the dest ipaddr here to better | |
155 | * comply with RFC1051 in "noarp" mode. | |
156 | */ | |
157 | pkt->hard.dest = 0; | |
158 | return hdr_size; | |
159 | } | |
160 | /* otherwise, just fill it in and go! */ | |
161 | pkt->hard.dest = daddr; | |
162 | ||
163 | return hdr_size; /* success */ | |
164 | } | |
165 | ||
166 | ||
167 | static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, | |
168 | int bufnum) | |
169 | { | |
454d7c9b | 170 | struct arcnet_local *lp = netdev_priv(dev); |
1da177e4 LT |
171 | struct arc_hardware *hard = &pkt->hard; |
172 | int ofs; | |
173 | ||
174 | BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n", | |
175 | lp->next_tx, lp->cur_tx, bufnum); | |
176 | ||
177 | length -= ARC_HDR_SIZE; /* hard header is not included in packet length */ | |
178 | ||
179 | if (length > XMTU) { | |
180 | /* should never happen! other people already check for this. */ | |
181 | BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n", | |
182 | length, XMTU); | |
183 | length = XMTU; | |
184 | } | |
52edc17f | 185 | if (length >= MinTU) { |
1da177e4 LT |
186 | hard->offset[0] = 0; |
187 | hard->offset[1] = ofs = 512 - length; | |
188 | } else if (length > MTU) { | |
189 | hard->offset[0] = 0; | |
190 | hard->offset[1] = ofs = 512 - length - 3; | |
191 | } else | |
192 | hard->offset[0] = ofs = 256 - length; | |
193 | ||
194 | BUGMSG(D_DURING, "prepare_tx: length=%d ofs=%d\n", | |
195 | length,ofs); | |
196 | ||
197 | lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE); | |
198 | lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length); | |
199 | ||
200 | lp->lastload_dest = hard->dest; | |
201 | ||
202 | return 1; /* done */ | |
203 | } |