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/inetdevice.h> 22 #include <linux/lapb.h> 23 #include <linux/rtnetlink.h> 24 #include <linux/etherdevice.h> 25 #include <linux/hdlc.h> 26 27 static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr); 28 29 static int eth_tx(struct sk_buff *skb, struct net_device *dev) 30 { 31 int pad = ETH_ZLEN - skb->len; 32 if (pad > 0) { /* Pad the frame with zeros */ 33 int len = skb->len; 34 if (skb_tailroom(skb) < pad) 35 if (pskb_expand_head(skb, 0, pad, GFP_ATOMIC)) { 36 dev->stats.tx_dropped++; 37 dev_kfree_skb(skb); 38 return 0; 39 } 40 skb_put(skb, pad); 41 memset(skb->data + len, 0, pad); 42 } 43 return dev_to_hdlc(dev)->xmit(skb, dev); 44 } 45 46 47 static struct hdlc_proto proto = { 48 .type_trans = eth_type_trans, 49 .ioctl = raw_eth_ioctl, 50 .module = THIS_MODULE, 51 }; 52 53 54 static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr) 55 { 56 raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc; 57 const size_t size = sizeof(raw_hdlc_proto); 58 raw_hdlc_proto new_settings; 59 hdlc_device *hdlc = dev_to_hdlc(dev); 60 int result; 61 int (*old_ch_mtu)(struct net_device *, int); 62 int old_qlen; 63 64 switch (ifr->ifr_settings.type) { 65 case IF_GET_PROTO: 66 if (dev_to_hdlc(dev)->proto != &proto) 67 return -EINVAL; 68 ifr->ifr_settings.type = IF_PROTO_HDLC_ETH; 69 if (ifr->ifr_settings.size < size) { 70 ifr->ifr_settings.size = size; /* data size wanted */ 71 return -ENOBUFS; 72 } 73 if (copy_to_user(raw_s, hdlc->state, size)) 74 return -EFAULT; 75 return 0; 76 77 case IF_PROTO_HDLC_ETH: 78 if (!capable(CAP_NET_ADMIN)) 79 return -EPERM; 80 81 if (dev->flags & IFF_UP) 82 return -EBUSY; 83 84 if (copy_from_user(&new_settings, raw_s, size)) 85 return -EFAULT; 86 87 if (new_settings.encoding == ENCODING_DEFAULT) 88 new_settings.encoding = ENCODING_NRZ; 89 90 if (new_settings.parity == PARITY_DEFAULT) 91 new_settings.parity = PARITY_CRC16_PR1_CCITT; 92 93 result = hdlc->attach(dev, new_settings.encoding, 94 new_settings.parity); 95 if (result) 96 return result; 97 98 result = attach_hdlc_protocol(dev, &proto, 99 sizeof(raw_hdlc_proto)); 100 if (result) 101 return result; 102 memcpy(hdlc->state, &new_settings, size); 103 dev->hard_start_xmit = eth_tx; 104 old_ch_mtu = dev->change_mtu; 105 old_qlen = dev->tx_queue_len; 106 ether_setup(dev); 107 dev->change_mtu = old_ch_mtu; 108 dev->tx_queue_len = old_qlen; 109 random_ether_addr(dev->dev_addr); 110 netif_dormant_off(dev); 111 return 0; 112 } 113 114 return -EINVAL; 115 } 116 117 118 static int __init mod_init(void) 119 { 120 register_hdlc_protocol(&proto); 121 return 0; 122 } 123 124 125 126 static void __exit mod_exit(void) 127 { 128 unregister_hdlc_protocol(&proto); 129 } 130 131 132 module_init(mod_init); 133 module_exit(mod_exit); 134 135 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); 136 MODULE_DESCRIPTION("Ethernet encapsulation support for generic HDLC"); 137 MODULE_LICENSE("GPL v2"); 138