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