Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 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/sched.h> |
| 15 | #include <linux/timer.h> |
| 16 | #include <linux/string.h> |
| 17 | #include <linux/sockios.h> |
| 18 | #include <linux/net.h> |
| 19 | #include <net/ax25.h> |
| 20 | #include <linux/inet.h> |
| 21 | #include <linux/netdevice.h> |
| 22 | #include <linux/skbuff.h> |
| 23 | #include <net/sock.h> |
Arnaldo Carvalho de Melo | c752f07 | 2005-08-09 20:08:28 -0700 | [diff] [blame] | 24 | #include <net/tcp_states.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <asm/uaccess.h> |
| 26 | #include <asm/system.h> |
| 27 | #include <linux/fcntl.h> |
| 28 | #include <linux/mm.h> |
| 29 | #include <linux/interrupt.h> |
| 30 | #include <net/netrom.h> |
| 31 | |
| 32 | /* |
| 33 | * This routine purges all of the queues of frames. |
| 34 | */ |
| 35 | void nr_clear_queues(struct sock *sk) |
| 36 | { |
| 37 | struct nr_sock *nr = nr_sk(sk); |
| 38 | |
| 39 | skb_queue_purge(&sk->sk_write_queue); |
| 40 | skb_queue_purge(&nr->ack_queue); |
| 41 | skb_queue_purge(&nr->reseq_queue); |
| 42 | skb_queue_purge(&nr->frag_queue); |
| 43 | } |
| 44 | |
| 45 | /* |
| 46 | * This routine purges the input queue of those frames that have been |
| 47 | * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the |
| 48 | * SDL diagram. |
| 49 | */ |
| 50 | void nr_frames_acked(struct sock *sk, unsigned short nr) |
| 51 | { |
| 52 | struct nr_sock *nrom = nr_sk(sk); |
| 53 | struct sk_buff *skb; |
| 54 | |
| 55 | /* |
| 56 | * Remove all the ack-ed frames from the ack queue. |
| 57 | */ |
| 58 | if (nrom->va != nr) { |
| 59 | while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) { |
| 60 | skb = skb_dequeue(&nrom->ack_queue); |
| 61 | kfree_skb(skb); |
| 62 | nrom->va = (nrom->va + 1) % NR_MODULUS; |
| 63 | } |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | /* |
| 68 | * Requeue all the un-ack-ed frames on the output queue to be picked |
| 69 | * up by nr_kick called from the timer. This arrangement handles the |
| 70 | * possibility of an empty output queue. |
| 71 | */ |
| 72 | void nr_requeue_frames(struct sock *sk) |
| 73 | { |
| 74 | struct sk_buff *skb, *skb_prev = NULL; |
| 75 | |
| 76 | while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) { |
| 77 | if (skb_prev == NULL) |
| 78 | skb_queue_head(&sk->sk_write_queue, skb); |
| 79 | else |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 80 | skb_append(skb_prev, skb, &sk->sk_write_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | skb_prev = skb; |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | /* |
| 86 | * Validate that the value of nr is between va and vs. Return true or |
| 87 | * false for testing. |
| 88 | */ |
| 89 | int nr_validate_nr(struct sock *sk, unsigned short nr) |
| 90 | { |
| 91 | struct nr_sock *nrom = nr_sk(sk); |
| 92 | unsigned short vc = nrom->va; |
| 93 | |
| 94 | while (vc != nrom->vs) { |
| 95 | if (nr == vc) return 1; |
| 96 | vc = (vc + 1) % NR_MODULUS; |
| 97 | } |
| 98 | |
| 99 | return nr == nrom->vs; |
| 100 | } |
| 101 | |
| 102 | /* |
| 103 | * Check that ns is within the receive window. |
| 104 | */ |
| 105 | int nr_in_rx_window(struct sock *sk, unsigned short ns) |
| 106 | { |
| 107 | struct nr_sock *nr = nr_sk(sk); |
| 108 | unsigned short vc = nr->vr; |
| 109 | unsigned short vt = (nr->vl + nr->window) % NR_MODULUS; |
| 110 | |
| 111 | while (vc != vt) { |
| 112 | if (ns == vc) return 1; |
| 113 | vc = (vc + 1) % NR_MODULUS; |
| 114 | } |
| 115 | |
| 116 | return 0; |
| 117 | } |
| 118 | |
| 119 | /* |
| 120 | * This routine is called when the HDLC layer internally generates a |
| 121 | * control frame. |
| 122 | */ |
| 123 | void nr_write_internal(struct sock *sk, int frametype) |
| 124 | { |
| 125 | struct nr_sock *nr = nr_sk(sk); |
| 126 | struct sk_buff *skb; |
| 127 | unsigned char *dptr; |
| 128 | int len, timeout; |
| 129 | |
| 130 | len = NR_NETWORK_LEN + NR_TRANSPORT_LEN; |
| 131 | |
| 132 | switch (frametype & 0x0F) { |
| 133 | case NR_CONNREQ: |
| 134 | len += 17; |
| 135 | break; |
| 136 | case NR_CONNACK: |
| 137 | len += (nr->bpqext) ? 2 : 1; |
| 138 | break; |
| 139 | case NR_DISCREQ: |
| 140 | case NR_DISCACK: |
| 141 | case NR_INFOACK: |
| 142 | break; |
| 143 | default: |
| 144 | printk(KERN_ERR "NET/ROM: nr_write_internal - invalid frame type %d\n", frametype); |
| 145 | return; |
| 146 | } |
| 147 | |
| 148 | if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) |
| 149 | return; |
| 150 | |
| 151 | /* |
| 152 | * Space for AX.25 and NET/ROM network header |
| 153 | */ |
| 154 | skb_reserve(skb, NR_NETWORK_LEN); |
| 155 | |
| 156 | dptr = skb_put(skb, skb_tailroom(skb)); |
| 157 | |
| 158 | switch (frametype & 0x0F) { |
| 159 | case NR_CONNREQ: |
| 160 | timeout = nr->t1 / HZ; |
| 161 | *dptr++ = nr->my_index; |
| 162 | *dptr++ = nr->my_id; |
| 163 | *dptr++ = 0; |
| 164 | *dptr++ = 0; |
| 165 | *dptr++ = frametype; |
| 166 | *dptr++ = nr->window; |
| 167 | memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN); |
| 168 | dptr[6] &= ~AX25_CBIT; |
| 169 | dptr[6] &= ~AX25_EBIT; |
| 170 | dptr[6] |= AX25_SSSID_SPARE; |
| 171 | dptr += AX25_ADDR_LEN; |
| 172 | memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN); |
| 173 | dptr[6] &= ~AX25_CBIT; |
| 174 | dptr[6] &= ~AX25_EBIT; |
| 175 | dptr[6] |= AX25_SSSID_SPARE; |
| 176 | dptr += AX25_ADDR_LEN; |
| 177 | *dptr++ = timeout % 256; |
| 178 | *dptr++ = timeout / 256; |
| 179 | break; |
| 180 | |
| 181 | case NR_CONNACK: |
| 182 | *dptr++ = nr->your_index; |
| 183 | *dptr++ = nr->your_id; |
| 184 | *dptr++ = nr->my_index; |
| 185 | *dptr++ = nr->my_id; |
| 186 | *dptr++ = frametype; |
| 187 | *dptr++ = nr->window; |
| 188 | if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser; |
| 189 | break; |
| 190 | |
| 191 | case NR_DISCREQ: |
| 192 | case NR_DISCACK: |
| 193 | *dptr++ = nr->your_index; |
| 194 | *dptr++ = nr->your_id; |
| 195 | *dptr++ = 0; |
| 196 | *dptr++ = 0; |
| 197 | *dptr++ = frametype; |
| 198 | break; |
| 199 | |
| 200 | case NR_INFOACK: |
| 201 | *dptr++ = nr->your_index; |
| 202 | *dptr++ = nr->your_id; |
| 203 | *dptr++ = 0; |
| 204 | *dptr++ = nr->vr; |
| 205 | *dptr++ = frametype; |
| 206 | break; |
| 207 | } |
| 208 | |
| 209 | nr_transmit_buffer(sk, skb); |
| 210 | } |
| 211 | |
| 212 | /* |
| 213 | * This routine is called when a Connect Acknowledge with the Choke Flag |
| 214 | * set is needed to refuse a connection. |
| 215 | */ |
| 216 | void nr_transmit_refusal(struct sk_buff *skb, int mine) |
| 217 | { |
| 218 | struct sk_buff *skbn; |
| 219 | unsigned char *dptr; |
| 220 | int len; |
| 221 | |
| 222 | len = NR_NETWORK_LEN + NR_TRANSPORT_LEN + 1; |
| 223 | |
| 224 | if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL) |
| 225 | return; |
| 226 | |
| 227 | skb_reserve(skbn, 0); |
| 228 | |
| 229 | dptr = skb_put(skbn, NR_NETWORK_LEN + NR_TRANSPORT_LEN); |
| 230 | |
| 231 | memcpy(dptr, skb->data + 7, AX25_ADDR_LEN); |
| 232 | dptr[6] &= ~AX25_CBIT; |
| 233 | dptr[6] &= ~AX25_EBIT; |
| 234 | dptr[6] |= AX25_SSSID_SPARE; |
| 235 | dptr += AX25_ADDR_LEN; |
| 236 | |
| 237 | memcpy(dptr, skb->data + 0, AX25_ADDR_LEN); |
| 238 | dptr[6] &= ~AX25_CBIT; |
| 239 | dptr[6] |= AX25_EBIT; |
| 240 | dptr[6] |= AX25_SSSID_SPARE; |
| 241 | dptr += AX25_ADDR_LEN; |
| 242 | |
| 243 | *dptr++ = sysctl_netrom_network_ttl_initialiser; |
| 244 | |
| 245 | if (mine) { |
| 246 | *dptr++ = 0; |
| 247 | *dptr++ = 0; |
| 248 | *dptr++ = skb->data[15]; |
| 249 | *dptr++ = skb->data[16]; |
| 250 | } else { |
| 251 | *dptr++ = skb->data[15]; |
| 252 | *dptr++ = skb->data[16]; |
| 253 | *dptr++ = 0; |
| 254 | *dptr++ = 0; |
| 255 | } |
| 256 | |
| 257 | *dptr++ = NR_CONNACK | NR_CHOKE_FLAG; |
| 258 | *dptr++ = 0; |
| 259 | |
| 260 | if (!nr_route_frame(skbn, NULL)) |
| 261 | kfree_skb(skbn); |
| 262 | } |
| 263 | |
| 264 | void nr_disconnect(struct sock *sk, int reason) |
| 265 | { |
| 266 | nr_stop_t1timer(sk); |
| 267 | nr_stop_t2timer(sk); |
| 268 | nr_stop_t4timer(sk); |
| 269 | nr_stop_idletimer(sk); |
| 270 | |
| 271 | nr_clear_queues(sk); |
| 272 | |
| 273 | nr_sk(sk)->state = NR_STATE_0; |
| 274 | |
| 275 | sk->sk_state = TCP_CLOSE; |
| 276 | sk->sk_err = reason; |
| 277 | sk->sk_shutdown |= SEND_SHUTDOWN; |
| 278 | |
| 279 | if (!sock_flag(sk, SOCK_DEAD)) { |
| 280 | sk->sk_state_change(sk); |
| 281 | sock_set_flag(sk, SOCK_DEAD); |
| 282 | } |
| 283 | } |