1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Generic HDLC support routines for Linux 4 * HDLC support 5 * 6 * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl> 7 */ 8 9 #include <linux/errno.h> 10 #include <linux/hdlc.h> 11 #include <linux/if_arp.h> 12 #include <linux/inetdevice.h> 13 #include <linux/init.h> 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/pkt_sched.h> 17 #include <linux/poll.h> 18 #include <linux/rtnetlink.h> 19 #include <linux/skbuff.h> 20 21 22 static int raw_ioctl(struct net_device *dev, struct ifreq *ifr); 23 24 static __be16 raw_type_trans(struct sk_buff *skb, struct net_device *dev) 25 { 26 return cpu_to_be16(ETH_P_IP); 27 } 28 29 static struct hdlc_proto proto = { 30 .type_trans = raw_type_trans, 31 .ioctl = raw_ioctl, 32 .module = THIS_MODULE, 33 }; 34 35 36 static int raw_ioctl(struct net_device *dev, struct ifreq *ifr) 37 { 38 raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc; 39 const size_t size = sizeof(raw_hdlc_proto); 40 raw_hdlc_proto new_settings; 41 hdlc_device *hdlc = dev_to_hdlc(dev); 42 int result; 43 44 switch (ifr->ifr_settings.type) { 45 case IF_GET_PROTO: 46 if (dev_to_hdlc(dev)->proto != &proto) 47 return -EINVAL; 48 ifr->ifr_settings.type = IF_PROTO_HDLC; 49 if (ifr->ifr_settings.size < size) { 50 ifr->ifr_settings.size = size; /* data size wanted */ 51 return -ENOBUFS; 52 } 53 if (copy_to_user(raw_s, hdlc->state, size)) 54 return -EFAULT; 55 return 0; 56 57 case IF_PROTO_HDLC: 58 if (!capable(CAP_NET_ADMIN)) 59 return -EPERM; 60 61 if (dev->flags & IFF_UP) 62 return -EBUSY; 63 64 if (copy_from_user(&new_settings, raw_s, size)) 65 return -EFAULT; 66 67 if (new_settings.encoding == ENCODING_DEFAULT) 68 new_settings.encoding = ENCODING_NRZ; 69 70 if (new_settings.parity == PARITY_DEFAULT) 71 new_settings.parity = PARITY_CRC16_PR1_CCITT; 72 73 result = hdlc->attach(dev, new_settings.encoding, 74 new_settings.parity); 75 if (result) 76 return result; 77 78 result = attach_hdlc_protocol(dev, &proto, 79 sizeof(raw_hdlc_proto)); 80 if (result) 81 return result; 82 memcpy(hdlc->state, &new_settings, size); 83 dev->type = ARPHRD_RAWHDLC; 84 call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev); 85 netif_dormant_off(dev); 86 return 0; 87 } 88 89 return -EINVAL; 90 } 91 92 93 static int __init mod_init(void) 94 { 95 register_hdlc_protocol(&proto); 96 return 0; 97 } 98 99 100 101 static void __exit mod_exit(void) 102 { 103 unregister_hdlc_protocol(&proto); 104 } 105 106 107 module_init(mod_init); 108 module_exit(mod_exit); 109 110 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); 111 MODULE_DESCRIPTION("Raw HDLC protocol support for generic HDLC"); 112 MODULE_LICENSE("GPL v2"); 113