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1da177e4 LT |
1 | /* |
2 | * Linux ARCnet driver - "cap mode" packet encapsulation. | |
3 | * It adds sequence numbers to packets for communicating between a user space | |
4 | * application and the driver. After a transmit it sends a packet with protocol | |
5 | * byte 0 back up to the userspace containing the sequence number of the packet | |
6 | * plus the transmit-status on the ArcNet. | |
7 | * | |
8 | * Written 2002-4 by Esben Nielsen, Vestas Wind Systems A/S | |
9 | * Derived from arc-rawmode.c by Avery Pennarun. | |
10 | * arc-rawmode was in turned based on skeleton.c, see below. | |
11 | * | |
12 | * ********************** | |
13 | * | |
14 | * The original copyright of skeleton.c was as follows: | |
15 | * | |
16 | * skeleton.c Written 1993 by Donald Becker. | |
17 | * Copyright 1993 United States Government as represented by the | |
18 | * Director, National Security Agency. This software may only be used | |
19 | * and distributed according to the terms of the GNU General Public License as | |
20 | * modified by SRC, incorporated herein by reference. | |
21 | * | |
22 | * ********************** | |
23 | * | |
24 | * For more details, see drivers/net/arcnet.c | |
25 | * | |
26 | * ********************** | |
27 | */ | |
28 | ||
29 | #include <linux/module.h> | |
5a0e3ad6 | 30 | #include <linux/gfp.h> |
1da177e4 LT |
31 | #include <linux/init.h> |
32 | #include <linux/if_arp.h> | |
33 | #include <net/arp.h> | |
34 | #include <linux/netdevice.h> | |
35 | #include <linux/skbuff.h> | |
36 | #include <linux/arcdevice.h> | |
37 | ||
38 | #define VERSION "arcnet: cap mode (`c') encapsulation support loaded.\n" | |
39 | ||
1da177e4 LT |
40 | /* packet receiver */ |
41 | static void rx(struct net_device *dev, int bufnum, | |
42 | struct archdr *pkthdr, int length) | |
43 | { | |
454d7c9b | 44 | struct arcnet_local *lp = netdev_priv(dev); |
1da177e4 LT |
45 | struct sk_buff *skb; |
46 | struct archdr *pkt = pkthdr; | |
47 | char *pktbuf, *pkthdrbuf; | |
48 | int ofs; | |
49 | ||
50 | BUGMSG(D_DURING, "it's a raw(cap) packet (length=%d)\n", length); | |
51 | ||
52 | if (length >= MinTU) | |
53 | ofs = 512 - length; | |
54 | else | |
55 | ofs = 256 - length; | |
56 | ||
57 | skb = alloc_skb(length + ARC_HDR_SIZE + sizeof(int), GFP_ATOMIC); | |
58 | if (skb == NULL) { | |
59 | BUGMSG(D_NORMAL, "Memory squeeze, dropping packet.\n"); | |
5803c512 | 60 | dev->stats.rx_dropped++; |
1da177e4 LT |
61 | return; |
62 | } | |
63 | skb_put(skb, length + ARC_HDR_SIZE + sizeof(int)); | |
64 | skb->dev = dev; | |
459a98ed | 65 | skb_reset_mac_header(skb); |
98e399f8 | 66 | pkt = (struct archdr *)skb_mac_header(skb); |
1da177e4 LT |
67 | skb_pull(skb, ARC_HDR_SIZE); |
68 | ||
69 | /* up to sizeof(pkt->soft) has already been copied from the card */ | |
70 | /* squeeze in an int for the cap encapsulation */ | |
71 | ||
72 | /* use these variables to be sure we count in bytes, not in | |
73 | sizeof(struct archdr) */ | |
cb334648 JP |
74 | pktbuf = (char *)pkt; |
75 | pkthdrbuf = (char *)pkthdr; | |
76 | memcpy(pktbuf, pkthdrbuf, ARC_HDR_SIZE + sizeof(pkt->soft.cap.proto)); | |
77 | memcpy(pktbuf + ARC_HDR_SIZE + sizeof(pkt->soft.cap.proto) + sizeof(int), | |
78 | pkthdrbuf + ARC_HDR_SIZE + sizeof(pkt->soft.cap.proto), | |
79 | sizeof(struct archdr) - ARC_HDR_SIZE - sizeof(pkt->soft.cap.proto)); | |
1da177e4 LT |
80 | |
81 | if (length > sizeof(pkt->soft)) | |
82 | lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft), | |
83 | pkt->soft.raw + sizeof(pkt->soft) | |
84 | + sizeof(int), | |
85 | length - sizeof(pkt->soft)); | |
86 | ||
87 | BUGLVL(D_SKB) arcnet_dump_skb(dev, skb, "rx"); | |
88 | ||
09640e63 | 89 | skb->protocol = cpu_to_be16(ETH_P_ARCNET); |
1da177e4 | 90 | netif_rx(skb); |
1da177e4 LT |
91 | } |
92 | ||
1da177e4 LT |
93 | /* |
94 | * Create the ARCnet hard/soft headers for cap mode. | |
95 | * There aren't any soft headers in cap mode - not even the protocol id. | |
96 | */ | |
97 | static int build_header(struct sk_buff *skb, | |
98 | struct net_device *dev, | |
99 | unsigned short type, | |
100 | uint8_t daddr) | |
101 | { | |
102 | int hdr_size = ARC_HDR_SIZE; | |
cb334648 | 103 | struct archdr *pkt = (struct archdr *)skb_push(skb, hdr_size); |
1da177e4 LT |
104 | |
105 | BUGMSG(D_PROTO, "Preparing header for cap packet %x.\n", | |
cb334648 | 106 | *((int *)&pkt->soft.cap.cookie[0])); |
1da177e4 LT |
107 | /* |
108 | * Set the source hardware address. | |
109 | * | |
110 | * This is pretty pointless for most purposes, but it can help in | |
111 | * debugging. ARCnet does not allow us to change the source address in | |
112 | * the actual packet sent) | |
113 | */ | |
114 | pkt->hard.source = *dev->dev_addr; | |
115 | ||
116 | /* see linux/net/ethernet/eth.c to see where I got the following */ | |
117 | ||
118 | if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) { | |
119 | /* | |
120 | * FIXME: fill in the last byte of the dest ipaddr here to better | |
121 | * comply with RFC1051 in "noarp" mode. | |
122 | */ | |
123 | pkt->hard.dest = 0; | |
124 | return hdr_size; | |
125 | } | |
126 | /* otherwise, just fill it in and go! */ | |
127 | pkt->hard.dest = daddr; | |
128 | ||
129 | return hdr_size; /* success */ | |
130 | } | |
131 | ||
1da177e4 LT |
132 | static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length, |
133 | int bufnum) | |
134 | { | |
454d7c9b | 135 | struct arcnet_local *lp = netdev_priv(dev); |
1da177e4 LT |
136 | struct arc_hardware *hard = &pkt->hard; |
137 | int ofs; | |
138 | ||
1da177e4 LT |
139 | /* hard header is not included in packet length */ |
140 | length -= ARC_HDR_SIZE; | |
141 | /* And neither is the cookie field */ | |
142 | length -= sizeof(int); | |
143 | ||
144 | BUGMSG(D_DURING, "prepare_tx: txbufs=%d/%d/%d\n", | |
145 | lp->next_tx, lp->cur_tx, bufnum); | |
146 | ||
147 | BUGMSG(D_PROTO, "Sending for cap packet %x.\n", | |
cb334648 | 148 | *((int *)&pkt->soft.cap.cookie[0])); |
1da177e4 LT |
149 | |
150 | if (length > XMTU) { | |
151 | /* should never happen! other people already check for this. */ | |
152 | BUGMSG(D_NORMAL, "Bug! prepare_tx with size %d (> %d)\n", | |
153 | length, XMTU); | |
154 | length = XMTU; | |
155 | } | |
156 | if (length > MinTU) { | |
157 | hard->offset[0] = 0; | |
158 | hard->offset[1] = ofs = 512 - length; | |
159 | } else if (length > MTU) { | |
160 | hard->offset[0] = 0; | |
161 | hard->offset[1] = ofs = 512 - length - 3; | |
162 | } else | |
163 | hard->offset[0] = ofs = 256 - length; | |
164 | ||
165 | BUGMSG(D_DURING, "prepare_tx: length=%d ofs=%d\n", | |
cb334648 | 166 | length, ofs); |
1da177e4 | 167 | |
0da529a7 | 168 | /* Copy the arcnet-header + the protocol byte down: */ |
1da177e4 LT |
169 | lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE); |
170 | lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft.cap.proto, | |
171 | sizeof(pkt->soft.cap.proto)); | |
172 | ||
0da529a7 DM |
173 | /* Skip the extra integer we have written into it as a cookie |
174 | but write the rest of the message: */ | |
cb334648 JP |
175 | lp->hw.copy_to_card(dev, bufnum, ofs + 1, |
176 | ((unsigned char *)&pkt->soft.cap.mes), length - 1); | |
1da177e4 LT |
177 | |
178 | lp->lastload_dest = hard->dest; | |
179 | ||
0da529a7 | 180 | return 1; /* done */ |
1da177e4 LT |
181 | } |
182 | ||
1da177e4 LT |
183 | static int ack_tx(struct net_device *dev, int acked) |
184 | { | |
0da529a7 DM |
185 | struct arcnet_local *lp = netdev_priv(dev); |
186 | struct sk_buff *ackskb; | |
187 | struct archdr *ackpkt; | |
cb334648 | 188 | int length = sizeof(struct arc_cap); |
1da177e4 | 189 | |
0da529a7 | 190 | BUGMSG(D_DURING, "capmode: ack_tx: protocol: %x: result: %d\n", |
cb334648 | 191 | lp->outgoing.skb->protocol, acked); |
1da177e4 | 192 | |
0da529a7 | 193 | BUGLVL(D_SKB) arcnet_dump_skb(dev, lp->outgoing.skb, "ack_tx"); |
1da177e4 | 194 | |
0da529a7 | 195 | /* Now alloc a skb to send back up through the layers: */ |
cb334648 | 196 | ackskb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC); |
0da529a7 DM |
197 | if (ackskb == NULL) { |
198 | BUGMSG(D_NORMAL, "Memory squeeze, can't acknowledge.\n"); | |
199 | goto free_outskb; | |
200 | } | |
201 | ||
cb334648 | 202 | skb_put(ackskb, length + ARC_HDR_SIZE); |
0da529a7 DM |
203 | ackskb->dev = dev; |
204 | ||
205 | skb_reset_mac_header(ackskb); | |
206 | ackpkt = (struct archdr *)skb_mac_header(ackskb); | |
207 | /* skb_pull(ackskb, ARC_HDR_SIZE); */ | |
1da177e4 | 208 | |
0da529a7 DM |
209 | skb_copy_from_linear_data(lp->outgoing.skb, ackpkt, |
210 | ARC_HDR_SIZE + sizeof(struct arc_cap)); | |
211 | ackpkt->soft.cap.proto = 0; /* using protocol 0 for acknowledge */ | |
cb334648 | 212 | ackpkt->soft.cap.mes.ack = acked; |
1da177e4 | 213 | |
0da529a7 | 214 | BUGMSG(D_PROTO, "Ackknowledge for cap packet %x.\n", |
cb334648 | 215 | *((int *)&ackpkt->soft.cap.cookie[0])); |
1da177e4 | 216 | |
0da529a7 | 217 | ackskb->protocol = cpu_to_be16(ETH_P_ARCNET); |
1da177e4 | 218 | |
0da529a7 DM |
219 | BUGLVL(D_SKB) arcnet_dump_skb(dev, ackskb, "ack_tx_recv"); |
220 | netif_rx(ackskb); | |
1da177e4 | 221 | |
0da529a7 DM |
222 | free_outskb: |
223 | dev_kfree_skb_irq(lp->outgoing.skb); | |
224 | lp->outgoing.proto = NULL; /* We are always finished when in this protocol */ | |
1da177e4 | 225 | |
0da529a7 DM |
226 | return 0; |
227 | } | |
1da177e4 | 228 | |
0da529a7 DM |
229 | static struct ArcProto capmode_proto = |
230 | { | |
231 | 'r', | |
232 | XMTU, | |
233 | 0, | |
234 | rx, | |
235 | build_header, | |
236 | prepare_tx, | |
237 | NULL, | |
238 | ack_tx | |
239 | }; | |
1da177e4 | 240 | |
0da529a7 DM |
241 | static void arcnet_cap_init(void) |
242 | { | |
243 | int count; | |
1da177e4 | 244 | |
0da529a7 DM |
245 | for (count = 1; count <= 8; count++) |
246 | if (arc_proto_map[count] == arc_proto_default) | |
247 | arc_proto_map[count] = &capmode_proto; | |
248 | ||
249 | /* for cap mode, we only set the bcast proto if there's no better one */ | |
250 | if (arc_bcast_proto == arc_proto_default) | |
251 | arc_bcast_proto = &capmode_proto; | |
252 | ||
253 | arc_proto_default = &capmode_proto; | |
254 | arc_raw_proto = &capmode_proto; | |
1da177e4 | 255 | } |
0da529a7 DM |
256 | |
257 | static int __init capmode_module_init(void) | |
258 | { | |
259 | printk(VERSION); | |
260 | arcnet_cap_init(); | |
261 | return 0; | |
262 | } | |
263 | ||
264 | static void __exit capmode_module_exit(void) | |
265 | { | |
266 | arcnet_unregister_proto(&capmode_proto); | |
267 | } | |
268 | module_init(capmode_module_init); | |
269 | module_exit(capmode_module_exit); | |
270 | ||
271 | MODULE_LICENSE("GPL"); |