arc-rawmode.c 4.8 KB

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  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. #define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt
  27. #include <linux/module.h>
  28. #include <linux/gfp.h>
  29. #include <linux/init.h>
  30. #include <linux/if_arp.h>
  31. #include <net/arp.h>
  32. #include <linux/netdevice.h>
  33. #include <linux/skbuff.h>
  34. #include "arcdevice.h"
  35. /* packet receiver */
  36. static void rx(struct net_device *dev, int bufnum,
  37. struct archdr *pkthdr, int length)
  38. {
  39. struct arcnet_local *lp = netdev_priv(dev);
  40. struct sk_buff *skb;
  41. struct archdr *pkt = pkthdr;
  42. int ofs;
  43. arc_printk(D_DURING, dev, "it's a raw packet (length=%d)\n", length);
  44. if (length > MTU)
  45. ofs = 512 - length;
  46. else
  47. ofs = 256 - length;
  48. skb = alloc_skb(length + ARC_HDR_SIZE, GFP_ATOMIC);
  49. if (!skb) {
  50. dev->stats.rx_dropped++;
  51. return;
  52. }
  53. skb_put(skb, length + ARC_HDR_SIZE);
  54. skb->dev = dev;
  55. pkt = (struct archdr *)skb->data;
  56. skb_reset_mac_header(skb);
  57. skb_pull(skb, ARC_HDR_SIZE);
  58. /* up to sizeof(pkt->soft) has already been copied from the card */
  59. memcpy(pkt, pkthdr, sizeof(struct archdr));
  60. if (length > sizeof(pkt->soft))
  61. lp->hw.copy_from_card(dev, bufnum, ofs + sizeof(pkt->soft),
  62. pkt->soft.raw + sizeof(pkt->soft),
  63. length - sizeof(pkt->soft));
  64. if (BUGLVL(D_SKB))
  65. arcnet_dump_skb(dev, skb, "rx");
  66. skb->protocol = cpu_to_be16(ETH_P_ARCNET);
  67. netif_rx(skb);
  68. }
  69. /* Create the ARCnet hard/soft headers for raw mode.
  70. * There aren't any soft headers in raw mode - not even the protocol id.
  71. */
  72. static int build_header(struct sk_buff *skb, struct net_device *dev,
  73. unsigned short type, uint8_t daddr)
  74. {
  75. int hdr_size = ARC_HDR_SIZE;
  76. struct archdr *pkt = (struct archdr *)skb_push(skb, hdr_size);
  77. /* Set the source hardware address.
  78. *
  79. * This is pretty pointless for most purposes, but it can help in
  80. * debugging. ARCnet does not allow us to change the source address
  81. * in the actual packet sent.
  82. */
  83. pkt->hard.source = *dev->dev_addr;
  84. /* see linux/net/ethernet/eth.c to see where I got the following */
  85. if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {
  86. /* FIXME: fill in the last byte of the dest ipaddr here
  87. * to better comply with RFC1051 in "noarp" mode.
  88. */
  89. pkt->hard.dest = 0;
  90. return hdr_size;
  91. }
  92. /* otherwise, just fill it in and go! */
  93. pkt->hard.dest = daddr;
  94. return hdr_size; /* success */
  95. }
  96. static int prepare_tx(struct net_device *dev, struct archdr *pkt, int length,
  97. int bufnum)
  98. {
  99. struct arcnet_local *lp = netdev_priv(dev);
  100. struct arc_hardware *hard = &pkt->hard;
  101. int ofs;
  102. arc_printk(D_DURING, dev, "prepare_tx: txbufs=%d/%d/%d\n",
  103. lp->next_tx, lp->cur_tx, bufnum);
  104. /* hard header is not included in packet length */
  105. length -= ARC_HDR_SIZE;
  106. if (length > XMTU) {
  107. /* should never happen! other people already check for this. */
  108. arc_printk(D_NORMAL, dev, "Bug! prepare_tx with size %d (> %d)\n",
  109. length, XMTU);
  110. length = XMTU;
  111. }
  112. if (length >= MinTU) {
  113. hard->offset[0] = 0;
  114. hard->offset[1] = ofs = 512 - length;
  115. } else if (length > MTU) {
  116. hard->offset[0] = 0;
  117. hard->offset[1] = ofs = 512 - length - 3;
  118. } else {
  119. hard->offset[0] = ofs = 256 - length;
  120. }
  121. arc_printk(D_DURING, dev, "prepare_tx: length=%d ofs=%d\n",
  122. length, ofs);
  123. lp->hw.copy_to_card(dev, bufnum, 0, hard, ARC_HDR_SIZE);
  124. lp->hw.copy_to_card(dev, bufnum, ofs, &pkt->soft, length);
  125. lp->lastload_dest = hard->dest;
  126. return 1; /* done */
  127. }
  128. static struct ArcProto rawmode_proto = {
  129. .suffix = 'r',
  130. .mtu = XMTU,
  131. .rx = rx,
  132. .build_header = build_header,
  133. .prepare_tx = prepare_tx,
  134. .continue_tx = NULL,
  135. .ack_tx = NULL
  136. };
  137. static int __init arcnet_raw_init(void)
  138. {
  139. int count;
  140. pr_info("raw mode (`r') encapsulation support loaded\n");
  141. for (count = 0; count < 256; count++)
  142. if (arc_proto_map[count] == arc_proto_default)
  143. arc_proto_map[count] = &rawmode_proto;
  144. /* for raw mode, we only set the bcast proto if there's no better one */
  145. if (arc_bcast_proto == arc_proto_default)
  146. arc_bcast_proto = &rawmode_proto;
  147. arc_proto_default = &rawmode_proto;
  148. return 0;
  149. }
  150. static void __exit arcnet_raw_exit(void)
  151. {
  152. arcnet_unregister_proto(&rawmode_proto);
  153. }
  154. module_init(arcnet_raw_init);
  155. module_exit(arcnet_raw_exit);
  156. MODULE_LICENSE("GPL");