1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Generic HDLC support routines for Linux 4 * X.25 support 5 * 6 * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl> 7 */ 8 9 #include <linux/errno.h> 10 #include <linux/gfp.h> 11 #include <linux/hdlc.h> 12 #include <linux/if_arp.h> 13 #include <linux/inetdevice.h> 14 #include <linux/init.h> 15 #include <linux/kernel.h> 16 #include <linux/lapb.h> 17 #include <linux/module.h> 18 #include <linux/pkt_sched.h> 19 #include <linux/poll.h> 20 #include <linux/rtnetlink.h> 21 #include <linux/skbuff.h> 22 #include <net/x25device.h> 23 24 struct x25_state { 25 x25_hdlc_proto settings; 26 }; 27 28 static int x25_ioctl(struct net_device *dev, struct ifreq *ifr); 29 30 static struct x25_state *state(hdlc_device *hdlc) 31 { 32 return hdlc->state; 33 } 34 35 /* These functions are callbacks called by LAPB layer */ 36 37 static void x25_connect_disconnect(struct net_device *dev, int reason, int code) 38 { 39 struct sk_buff *skb; 40 unsigned char *ptr; 41 42 if ((skb = dev_alloc_skb(1)) == NULL) { 43 netdev_err(dev, "out of memory\n"); 44 return; 45 } 46 47 ptr = skb_put(skb, 1); 48 *ptr = code; 49 50 skb->protocol = x25_type_trans(skb, dev); 51 netif_rx(skb); 52 } 53 54 55 56 static void x25_connected(struct net_device *dev, int reason) 57 { 58 x25_connect_disconnect(dev, reason, X25_IFACE_CONNECT); 59 } 60 61 62 63 static void x25_disconnected(struct net_device *dev, int reason) 64 { 65 x25_connect_disconnect(dev, reason, X25_IFACE_DISCONNECT); 66 } 67 68 69 70 static int x25_data_indication(struct net_device *dev, struct sk_buff *skb) 71 { 72 unsigned char *ptr; 73 74 if (skb_cow(skb, 1)) { 75 kfree_skb(skb); 76 return NET_RX_DROP; 77 } 78 79 skb_push(skb, 1); 80 skb_reset_network_header(skb); 81 82 ptr = skb->data; 83 *ptr = X25_IFACE_DATA; 84 85 skb->protocol = x25_type_trans(skb, dev); 86 return netif_rx(skb); 87 } 88 89 90 91 static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb) 92 { 93 hdlc_device *hdlc = dev_to_hdlc(dev); 94 95 skb_reset_network_header(skb); 96 skb->protocol = hdlc_type_trans(skb, dev); 97 98 if (dev_nit_active(dev)) 99 dev_queue_xmit_nit(skb, dev); 100 101 hdlc->xmit(skb, dev); /* Ignore return value :-( */ 102 } 103 104 105 106 static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev) 107 { 108 int result; 109 110 111 /* X.25 to LAPB */ 112 switch (skb->data[0]) { 113 case X25_IFACE_DATA: /* Data to be transmitted */ 114 skb_pull(skb, 1); 115 skb_reset_network_header(skb); 116 if ((result = lapb_data_request(dev, skb)) != LAPB_OK) 117 dev_kfree_skb(skb); 118 return NETDEV_TX_OK; 119 120 case X25_IFACE_CONNECT: 121 if ((result = lapb_connect_request(dev))!= LAPB_OK) { 122 if (result == LAPB_CONNECTED) 123 /* Send connect confirm. msg to level 3 */ 124 x25_connected(dev, 0); 125 else 126 netdev_err(dev, "LAPB connect request failed, error code = %i\n", 127 result); 128 } 129 break; 130 131 case X25_IFACE_DISCONNECT: 132 if ((result = lapb_disconnect_request(dev)) != LAPB_OK) { 133 if (result == LAPB_NOTCONNECTED) 134 /* Send disconnect confirm. msg to level 3 */ 135 x25_disconnected(dev, 0); 136 else 137 netdev_err(dev, "LAPB disconnect request failed, error code = %i\n", 138 result); 139 } 140 break; 141 142 default: /* to be defined */ 143 break; 144 } 145 146 dev_kfree_skb(skb); 147 return NETDEV_TX_OK; 148 } 149 150 151 152 static int x25_open(struct net_device *dev) 153 { 154 static const struct lapb_register_struct cb = { 155 .connect_confirmation = x25_connected, 156 .connect_indication = x25_connected, 157 .disconnect_confirmation = x25_disconnected, 158 .disconnect_indication = x25_disconnected, 159 .data_indication = x25_data_indication, 160 .data_transmit = x25_data_transmit, 161 }; 162 hdlc_device *hdlc = dev_to_hdlc(dev); 163 struct lapb_parms_struct params; 164 int result; 165 166 result = lapb_register(dev, &cb); 167 if (result != LAPB_OK) 168 return result; 169 170 result = lapb_getparms(dev, ¶ms); 171 if (result != LAPB_OK) 172 return result; 173 174 if (state(hdlc)->settings.dce) 175 params.mode = params.mode | LAPB_DCE; 176 177 if (state(hdlc)->settings.modulo == 128) 178 params.mode = params.mode | LAPB_EXTENDED; 179 180 params.window = state(hdlc)->settings.window; 181 params.t1 = state(hdlc)->settings.t1; 182 params.t2 = state(hdlc)->settings.t2; 183 params.n2 = state(hdlc)->settings.n2; 184 185 result = lapb_setparms(dev, ¶ms); 186 if (result != LAPB_OK) 187 return result; 188 189 return 0; 190 } 191 192 193 194 static void x25_close(struct net_device *dev) 195 { 196 lapb_unregister(dev); 197 } 198 199 200 201 static int x25_rx(struct sk_buff *skb) 202 { 203 struct net_device *dev = skb->dev; 204 205 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) { 206 dev->stats.rx_dropped++; 207 return NET_RX_DROP; 208 } 209 210 if (lapb_data_received(dev, skb) == LAPB_OK) 211 return NET_RX_SUCCESS; 212 213 dev->stats.rx_errors++; 214 dev_kfree_skb_any(skb); 215 return NET_RX_DROP; 216 } 217 218 219 static struct hdlc_proto proto = { 220 .open = x25_open, 221 .close = x25_close, 222 .ioctl = x25_ioctl, 223 .netif_rx = x25_rx, 224 .xmit = x25_xmit, 225 .module = THIS_MODULE, 226 }; 227 228 229 static int x25_ioctl(struct net_device *dev, struct ifreq *ifr) 230 { 231 x25_hdlc_proto __user *x25_s = ifr->ifr_settings.ifs_ifsu.x25; 232 const size_t size = sizeof(x25_hdlc_proto); 233 hdlc_device *hdlc = dev_to_hdlc(dev); 234 x25_hdlc_proto new_settings; 235 int result; 236 237 switch (ifr->ifr_settings.type) { 238 case IF_GET_PROTO: 239 if (dev_to_hdlc(dev)->proto != &proto) 240 return -EINVAL; 241 ifr->ifr_settings.type = IF_PROTO_X25; 242 if (ifr->ifr_settings.size < size) { 243 ifr->ifr_settings.size = size; /* data size wanted */ 244 return -ENOBUFS; 245 } 246 if (copy_to_user(x25_s, &state(hdlc)->settings, size)) 247 return -EFAULT; 248 return 0; 249 250 case IF_PROTO_X25: 251 if (!capable(CAP_NET_ADMIN)) 252 return -EPERM; 253 254 if (dev->flags & IFF_UP) 255 return -EBUSY; 256 257 /* backward compatibility */ 258 if (ifr->ifr_settings.size == 0) { 259 new_settings.dce = 0; 260 new_settings.modulo = 8; 261 new_settings.window = 7; 262 new_settings.t1 = 3; 263 new_settings.t2 = 1; 264 new_settings.n2 = 10; 265 } 266 else { 267 if (copy_from_user(&new_settings, x25_s, size)) 268 return -EFAULT; 269 270 if ((new_settings.dce != 0 && 271 new_settings.dce != 1) || 272 (new_settings.modulo != 8 && 273 new_settings.modulo != 128) || 274 new_settings.window < 1 || 275 (new_settings.modulo == 8 && 276 new_settings.window > 7) || 277 (new_settings.modulo == 128 && 278 new_settings.window > 127) || 279 new_settings.t1 < 1 || 280 new_settings.t1 > 255 || 281 new_settings.t2 < 1 || 282 new_settings.t2 > 255 || 283 new_settings.n2 < 1 || 284 new_settings.n2 > 255) 285 return -EINVAL; 286 } 287 288 result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT); 289 if (result) 290 return result; 291 292 if ((result = attach_hdlc_protocol(dev, &proto, 293 sizeof(struct x25_state)))) 294 return result; 295 296 memcpy(&state(hdlc)->settings, &new_settings, size); 297 dev->type = ARPHRD_X25; 298 call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev); 299 netif_dormant_off(dev); 300 return 0; 301 } 302 303 return -EINVAL; 304 } 305 306 307 static int __init mod_init(void) 308 { 309 register_hdlc_protocol(&proto); 310 return 0; 311 } 312 313 314 315 static void __exit mod_exit(void) 316 { 317 unregister_hdlc_protocol(&proto); 318 } 319 320 321 module_init(mod_init); 322 module_exit(mod_exit); 323 324 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>"); 325 MODULE_DESCRIPTION("X.25 protocol support for generic HDLC"); 326 MODULE_LICENSE("GPL v2"); 327