1 /* 2 * Generic HDLC support routines for Linux 3 * HDLC Ethernet emulation support 4 * 5 * Copyright (C) 2002-2006 Krzysztof Halasa <khc@pm.waw.pl> 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms of version 2 of the GNU General Public License 9 * as published by the Free Software Foundation. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/kernel.h> 14 #include <linux/slab.h> 15 #include <linux/poll.h> 16 #include <linux/errno.h> 17 #include <linux/if_arp.h> 18 #include <linux/init.h> 19 #include <linux/skbuff.h> 20 #include <linux/pkt_sched.h> 21 #include <linux/random.h> 22 #include <linux/inetdevice.h> 23 #include <linux/lapb.h> 24 #include <linux/rtnetlink.h> 25 #include <linux/etherdevice.h> 26 #include <linux/hdlc.h> 27 28 static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr); 29 30 static int eth_tx(struct sk_buff *skb, struct net_device *dev) 31 { 32 int pad = ETH_ZLEN - skb->len; 33 if (pad > 0) { /* Pad the frame with zeros */ 34 int len = skb->len; 35 if (skb_tailroom(skb) < pad) 36 if (pskb_expand_head(skb, 0, pad, GFP_ATOMIC)) { 37 hdlc_stats(dev)->tx_dropped++; 38 dev_kfree_skb(skb); 39 return 0; 40 } 41 skb_put(skb, pad); 42 memset(skb->data + len, 0, pad); 43 } 44 return dev_to_hdlc(dev)->xmit(skb, dev); 45 } 46 47 48 static struct hdlc_proto proto = { 49 .type_trans = eth_type_trans, 50 .ioctl = raw_eth_ioctl, 51 .module = THIS_MODULE, 52 }; 53 54 55 static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr) 56 { 57 raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc; 58 const size_t size = sizeof(raw_hdlc_proto); 59 raw_hdlc_proto new_settings; 60 hdlc_device *hdlc = dev_to_hdlc(dev); 61 int result; 62 int (*old_ch_mtu)(struct net_device *, int); 63 int old_qlen; 64 65 switch (ifr->ifr_settings.type) { 66 case IF_GET_PROTO: 67 if (dev_to_hdlc(dev)->proto != &proto) 68 return -EINVAL; 69 ifr->ifr_settings.type = IF_PROTO_HDLC_ETH; 70 if (ifr->ifr_settings.size < size) { 71 ifr->ifr_settings.size = size; /* data size wanted */ 72 return -ENOBUFS; 73 } 74 if (copy_to_user(raw_s, hdlc->state, size)) 75 return -EFAULT; 76 return 0; 77 78 case IF_PROTO_HDLC_ETH: 79 if (!capable(CAP_NET_ADMIN)) 80 return -EPERM; 81 82 if (dev->flags & IFF_UP) 83 return -EBUSY; 84 85 if (copy_from_user(&new_settings, raw_s, size)) 86 return -EFAULT; 87 88 if (new_settings.encoding == ENCODING_DEFAULT) 89 new_settings.encoding = ENCODING_NRZ; 90 91 if (new_settings.parity == PARITY_DEFAULT) 92 new_settings.parity = PARITY_CRC16_PR1_CCITT; 93 94 result = hdlc->attach(dev, new_settings.encoding, 95 new_settings.parity); 96 if (result) 97 return result; 98 99 result = attach_hdlc_protocol(dev, &proto, NULL, 100 sizeof(raw_hdlc_proto)); 101 if (result) 102 return result; 103 memcpy(hdlc->state, &new_settings, size); 104 dev->hard_start_xmit = eth_tx; 105 old_ch_mtu = dev->change_mtu; 106 old_qlen = dev->tx_queue_len; 107 ether_setup(dev); 108 dev->change_mtu = old_ch_mtu; 109 dev->tx_queue_len = old_qlen; 110 memcpy(dev->dev_addr, "\x00\x01", 2); 111 get_random_bytes(dev->dev_addr + 2, ETH_ALEN - 2); 112 netif_dormant_off(dev); 113 return 0; 114 } 115 116 return -EINVAL; 117 } 118 119 120 static int __init mod_init(void) 121 { 122 register_hdlc_protocol(&proto); 123 return 0; 124 } 125 126 127 128 static void __exit mod_exit(void) 129 { 130 unregister_hdlc_protocol(&proto); 131 } 132 133 134 module_init(mod_init); 135 module_exit(mod_exit); 136 137 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); 138 MODULE_DESCRIPTION("Ethernet encapsulation support for generic HDLC"); 139 MODULE_LICENSE("GPL v2"); 140