1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License as published by 4 * the Free Software Foundation; either version 2 of the License, or 5 * (at your option) any later version. 6 * 7 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) 8 */ 9 #include <linux/errno.h> 10 #include <linux/types.h> 11 #include <linux/socket.h> 12 #include <linux/in.h> 13 #include <linux/kernel.h> 14 #include <linux/jiffies.h> 15 #include <linux/timer.h> 16 #include <linux/string.h> 17 #include <linux/sockios.h> 18 #include <linux/net.h> 19 #include <linux/slab.h> 20 #include <net/ax25.h> 21 #include <linux/inet.h> 22 #include <linux/netdevice.h> 23 #include <linux/skbuff.h> 24 #include <net/sock.h> 25 #include <asm/system.h> 26 #include <linux/fcntl.h> 27 #include <linux/mm.h> 28 #include <linux/interrupt.h> 29 #include <linux/netfilter.h> 30 #include <net/rose.h> 31 32 static void rose_ftimer_expiry(unsigned long); 33 static void rose_t0timer_expiry(unsigned long); 34 35 static void rose_transmit_restart_confirmation(struct rose_neigh *neigh); 36 static void rose_transmit_restart_request(struct rose_neigh *neigh); 37 38 void rose_start_ftimer(struct rose_neigh *neigh) 39 { 40 del_timer(&neigh->ftimer); 41 42 neigh->ftimer.data = (unsigned long)neigh; 43 neigh->ftimer.function = &rose_ftimer_expiry; 44 neigh->ftimer.expires = 45 jiffies + msecs_to_jiffies(sysctl_rose_link_fail_timeout); 46 47 add_timer(&neigh->ftimer); 48 } 49 50 static void rose_start_t0timer(struct rose_neigh *neigh) 51 { 52 del_timer(&neigh->t0timer); 53 54 neigh->t0timer.data = (unsigned long)neigh; 55 neigh->t0timer.function = &rose_t0timer_expiry; 56 neigh->t0timer.expires = 57 jiffies + msecs_to_jiffies(sysctl_rose_restart_request_timeout); 58 59 add_timer(&neigh->t0timer); 60 } 61 62 void rose_stop_ftimer(struct rose_neigh *neigh) 63 { 64 del_timer(&neigh->ftimer); 65 } 66 67 void rose_stop_t0timer(struct rose_neigh *neigh) 68 { 69 del_timer(&neigh->t0timer); 70 } 71 72 int rose_ftimer_running(struct rose_neigh *neigh) 73 { 74 return timer_pending(&neigh->ftimer); 75 } 76 77 static int rose_t0timer_running(struct rose_neigh *neigh) 78 { 79 return timer_pending(&neigh->t0timer); 80 } 81 82 static void rose_ftimer_expiry(unsigned long param) 83 { 84 } 85 86 static void rose_t0timer_expiry(unsigned long param) 87 { 88 struct rose_neigh *neigh = (struct rose_neigh *)param; 89 90 rose_transmit_restart_request(neigh); 91 92 neigh->dce_mode = 0; 93 94 rose_start_t0timer(neigh); 95 } 96 97 /* 98 * Interface to ax25_send_frame. Changes my level 2 callsign depending 99 * on whether we have a global ROSE callsign or use the default port 100 * callsign. 101 */ 102 static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh) 103 { 104 ax25_address *rose_call; 105 ax25_cb *ax25s; 106 107 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0) 108 rose_call = (ax25_address *)neigh->dev->dev_addr; 109 else 110 rose_call = &rose_callsign; 111 112 ax25s = neigh->ax25; 113 neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev); 114 if (ax25s) 115 ax25_cb_put(ax25s); 116 117 return neigh->ax25 != NULL; 118 } 119 120 /* 121 * Interface to ax25_link_up. Changes my level 2 callsign depending 122 * on whether we have a global ROSE callsign or use the default port 123 * callsign. 124 */ 125 static int rose_link_up(struct rose_neigh *neigh) 126 { 127 ax25_address *rose_call; 128 ax25_cb *ax25s; 129 130 if (ax25cmp(&rose_callsign, &null_ax25_address) == 0) 131 rose_call = (ax25_address *)neigh->dev->dev_addr; 132 else 133 rose_call = &rose_callsign; 134 135 ax25s = neigh->ax25; 136 neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev); 137 if (ax25s) 138 ax25_cb_put(ax25s); 139 140 return neigh->ax25 != NULL; 141 } 142 143 /* 144 * This handles all restart and diagnostic frames. 145 */ 146 void rose_link_rx_restart(struct sk_buff *skb, struct rose_neigh *neigh, unsigned short frametype) 147 { 148 struct sk_buff *skbn; 149 150 switch (frametype) { 151 case ROSE_RESTART_REQUEST: 152 rose_stop_t0timer(neigh); 153 neigh->restarted = 1; 154 neigh->dce_mode = (skb->data[3] == ROSE_DTE_ORIGINATED); 155 rose_transmit_restart_confirmation(neigh); 156 break; 157 158 case ROSE_RESTART_CONFIRMATION: 159 rose_stop_t0timer(neigh); 160 neigh->restarted = 1; 161 break; 162 163 case ROSE_DIAGNOSTIC: 164 printk(KERN_WARNING "ROSE: received diagnostic #%d - %02X %02X %02X\n", skb->data[3], skb->data[4], skb->data[5], skb->data[6]); 165 break; 166 167 default: 168 printk(KERN_WARNING "ROSE: received unknown %02X with LCI 000\n", frametype); 169 break; 170 } 171 172 if (neigh->restarted) { 173 while ((skbn = skb_dequeue(&neigh->queue)) != NULL) 174 if (!rose_send_frame(skbn, neigh)) 175 kfree_skb(skbn); 176 } 177 } 178 179 /* 180 * This routine is called when a Restart Request is needed 181 */ 182 static void rose_transmit_restart_request(struct rose_neigh *neigh) 183 { 184 struct sk_buff *skb; 185 unsigned char *dptr; 186 int len; 187 188 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3; 189 190 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) 191 return; 192 193 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); 194 195 dptr = skb_put(skb, ROSE_MIN_LEN + 3); 196 197 *dptr++ = AX25_P_ROSE; 198 *dptr++ = ROSE_GFI; 199 *dptr++ = 0x00; 200 *dptr++ = ROSE_RESTART_REQUEST; 201 *dptr++ = ROSE_DTE_ORIGINATED; 202 *dptr++ = 0; 203 204 if (!rose_send_frame(skb, neigh)) 205 kfree_skb(skb); 206 } 207 208 /* 209 * This routine is called when a Restart Confirmation is needed 210 */ 211 static void rose_transmit_restart_confirmation(struct rose_neigh *neigh) 212 { 213 struct sk_buff *skb; 214 unsigned char *dptr; 215 int len; 216 217 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 1; 218 219 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) 220 return; 221 222 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); 223 224 dptr = skb_put(skb, ROSE_MIN_LEN + 1); 225 226 *dptr++ = AX25_P_ROSE; 227 *dptr++ = ROSE_GFI; 228 *dptr++ = 0x00; 229 *dptr++ = ROSE_RESTART_CONFIRMATION; 230 231 if (!rose_send_frame(skb, neigh)) 232 kfree_skb(skb); 233 } 234 235 /* 236 * This routine is called when a Clear Request is needed outside of the context 237 * of a connected socket. 238 */ 239 void rose_transmit_clear_request(struct rose_neigh *neigh, unsigned int lci, unsigned char cause, unsigned char diagnostic) 240 { 241 struct sk_buff *skb; 242 unsigned char *dptr; 243 int len; 244 245 len = AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN + ROSE_MIN_LEN + 3; 246 247 if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) 248 return; 249 250 skb_reserve(skb, AX25_BPQ_HEADER_LEN + AX25_MAX_HEADER_LEN); 251 252 dptr = skb_put(skb, ROSE_MIN_LEN + 3); 253 254 *dptr++ = AX25_P_ROSE; 255 *dptr++ = ((lci >> 8) & 0x0F) | ROSE_GFI; 256 *dptr++ = ((lci >> 0) & 0xFF); 257 *dptr++ = ROSE_CLEAR_REQUEST; 258 *dptr++ = cause; 259 *dptr++ = diagnostic; 260 261 if (!rose_send_frame(skb, neigh)) 262 kfree_skb(skb); 263 } 264 265 void rose_transmit_link(struct sk_buff *skb, struct rose_neigh *neigh) 266 { 267 unsigned char *dptr; 268 269 if (neigh->loopback) { 270 rose_loopback_queue(skb, neigh); 271 return; 272 } 273 274 if (!rose_link_up(neigh)) 275 neigh->restarted = 0; 276 277 dptr = skb_push(skb, 1); 278 *dptr++ = AX25_P_ROSE; 279 280 if (neigh->restarted) { 281 if (!rose_send_frame(skb, neigh)) 282 kfree_skb(skb); 283 } else { 284 skb_queue_tail(&neigh->queue, skb); 285 286 if (!rose_t0timer_running(neigh)) { 287 rose_transmit_restart_request(neigh); 288 neigh->dce_mode = 0; 289 rose_start_t0timer(neigh); 290 } 291 } 292 } 293