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/gfp.h> 15 #include <linux/hdlc.h> 16 #include <linux/if_arp.h> 17 #include <linux/inetdevice.h> 18 #include <linux/init.h> 19 #include <linux/kernel.h> 20 #include <linux/module.h> 21 #include <linux/pkt_sched.h> 22 #include <linux/poll.h> 23 #include <linux/rtnetlink.h> 24 #include <linux/skbuff.h> 25 26 static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr); 27 28 static netdev_tx_t 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 .xmit = eth_tx, 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, old_qlen; 61 62 switch (ifr->ifr_settings.type) { 63 case IF_GET_PROTO: 64 if (dev_to_hdlc(dev)->proto != &proto) 65 return -EINVAL; 66 ifr->ifr_settings.type = IF_PROTO_HDLC_ETH; 67 if (ifr->ifr_settings.size < size) { 68 ifr->ifr_settings.size = size; /* data size wanted */ 69 return -ENOBUFS; 70 } 71 if (copy_to_user(raw_s, hdlc->state, size)) 72 return -EFAULT; 73 return 0; 74 75 case IF_PROTO_HDLC_ETH: 76 if (!capable(CAP_NET_ADMIN)) 77 return -EPERM; 78 79 if (dev->flags & IFF_UP) 80 return -EBUSY; 81 82 if (copy_from_user(&new_settings, raw_s, size)) 83 return -EFAULT; 84 85 if (new_settings.encoding == ENCODING_DEFAULT) 86 new_settings.encoding = ENCODING_NRZ; 87 88 if (new_settings.parity == PARITY_DEFAULT) 89 new_settings.parity = PARITY_CRC16_PR1_CCITT; 90 91 result = hdlc->attach(dev, new_settings.encoding, 92 new_settings.parity); 93 if (result) 94 return result; 95 96 result = attach_hdlc_protocol(dev, &proto, 97 sizeof(raw_hdlc_proto)); 98 if (result) 99 return result; 100 memcpy(hdlc->state, &new_settings, size); 101 old_qlen = dev->tx_queue_len; 102 ether_setup(dev); 103 dev->tx_queue_len = old_qlen; 104 eth_hw_addr_random(dev); 105 netif_dormant_off(dev); 106 return 0; 107 } 108 109 return -EINVAL; 110 } 111 112 113 static int __init mod_init(void) 114 { 115 register_hdlc_protocol(&proto); 116 return 0; 117 } 118 119 120 121 static void __exit mod_exit(void) 122 { 123 unregister_hdlc_protocol(&proto); 124 } 125 126 127 module_init(mod_init); 128 module_exit(mod_exit); 129 130 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); 131 MODULE_DESCRIPTION("Ethernet encapsulation support for generic HDLC"); 132 MODULE_LICENSE("GPL v2"); 133