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