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