nr_dev.c 3.7 KB

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  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. #include <asm/io.h>
  22. #include <linux/inet.h>
  23. #include <linux/netdevice.h>
  24. #include <linux/etherdevice.h>
  25. #include <linux/if_arp.h>
  26. #include <linux/skbuff.h>
  27. #include <net/ip.h>
  28. #include <net/arp.h>
  29. #include <net/ax25.h>
  30. #include <net/netrom.h>
  31. /*
  32. * Only allow IP over NET/ROM frames through if the netrom device is up.
  33. */
  34. int nr_rx_ip(struct sk_buff *skb, struct net_device *dev)
  35. {
  36. struct net_device_stats *stats = &dev->stats;
  37. if (!netif_running(dev)) {
  38. stats->rx_dropped++;
  39. return 0;
  40. }
  41. stats->rx_packets++;
  42. stats->rx_bytes += skb->len;
  43. skb->protocol = htons(ETH_P_IP);
  44. /* Spoof incoming device */
  45. skb->dev = dev;
  46. skb->mac_header = skb->network_header;
  47. skb_reset_network_header(skb);
  48. skb->pkt_type = PACKET_HOST;
  49. netif_rx(skb);
  50. return 1;
  51. }
  52. static int nr_header(struct sk_buff *skb, struct net_device *dev,
  53. unsigned short type,
  54. const void *daddr, const void *saddr, unsigned int len)
  55. {
  56. unsigned char *buff = skb_push(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
  57. memcpy(buff, (saddr != NULL) ? saddr : dev->dev_addr, dev->addr_len);
  58. buff[6] &= ~AX25_CBIT;
  59. buff[6] &= ~AX25_EBIT;
  60. buff[6] |= AX25_SSSID_SPARE;
  61. buff += AX25_ADDR_LEN;
  62. if (daddr != NULL)
  63. memcpy(buff, daddr, dev->addr_len);
  64. buff[6] &= ~AX25_CBIT;
  65. buff[6] |= AX25_EBIT;
  66. buff[6] |= AX25_SSSID_SPARE;
  67. buff += AX25_ADDR_LEN;
  68. *buff++ = sysctl_netrom_network_ttl_initialiser;
  69. *buff++ = NR_PROTO_IP;
  70. *buff++ = NR_PROTO_IP;
  71. *buff++ = 0;
  72. *buff++ = 0;
  73. *buff++ = NR_PROTOEXT;
  74. if (daddr != NULL)
  75. return 37;
  76. return -37;
  77. }
  78. static int __must_check nr_set_mac_address(struct net_device *dev, void *addr)
  79. {
  80. struct sockaddr *sa = addr;
  81. int err;
  82. if (!memcmp(dev->dev_addr, sa->sa_data, dev->addr_len))
  83. return 0;
  84. if (dev->flags & IFF_UP) {
  85. err = ax25_listen_register((ax25_address *)sa->sa_data, NULL);
  86. if (err)
  87. return err;
  88. ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
  89. }
  90. memcpy(dev->dev_addr, sa->sa_data, dev->addr_len);
  91. return 0;
  92. }
  93. static int nr_open(struct net_device *dev)
  94. {
  95. int err;
  96. err = ax25_listen_register((ax25_address *)dev->dev_addr, NULL);
  97. if (err)
  98. return err;
  99. netif_start_queue(dev);
  100. return 0;
  101. }
  102. static int nr_close(struct net_device *dev)
  103. {
  104. ax25_listen_release((ax25_address *)dev->dev_addr, NULL);
  105. netif_stop_queue(dev);
  106. return 0;
  107. }
  108. static netdev_tx_t nr_xmit(struct sk_buff *skb, struct net_device *dev)
  109. {
  110. struct net_device_stats *stats = &dev->stats;
  111. unsigned int len = skb->len;
  112. if (!nr_route_frame(skb, NULL)) {
  113. kfree_skb(skb);
  114. stats->tx_errors++;
  115. return NETDEV_TX_OK;
  116. }
  117. stats->tx_packets++;
  118. stats->tx_bytes += len;
  119. return NETDEV_TX_OK;
  120. }
  121. static const struct header_ops nr_header_ops = {
  122. .create = nr_header,
  123. };
  124. static const struct net_device_ops nr_netdev_ops = {
  125. .ndo_open = nr_open,
  126. .ndo_stop = nr_close,
  127. .ndo_start_xmit = nr_xmit,
  128. .ndo_set_mac_address = nr_set_mac_address,
  129. };
  130. void nr_setup(struct net_device *dev)
  131. {
  132. dev->mtu = NR_MAX_PACKET_SIZE;
  133. dev->netdev_ops = &nr_netdev_ops;
  134. dev->header_ops = &nr_header_ops;
  135. dev->hard_header_len = NR_NETWORK_LEN + NR_TRANSPORT_LEN;
  136. dev->addr_len = AX25_ADDR_LEN;
  137. dev->type = ARPHRD_NETROM;
  138. /* New-style flags. */
  139. dev->flags = IFF_NOARP;
  140. }