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 (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) |
| 8 | * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de) |
| 9 | */ |
| 10 | #include <linux/errno.h> |
| 11 | #include <linux/types.h> |
| 12 | #include <linux/socket.h> |
| 13 | #include <linux/in.h> |
| 14 | #include <linux/kernel.h> |
| 15 | #include <linux/sched.h> |
| 16 | #include <linux/timer.h> |
| 17 | #include <linux/string.h> |
| 18 | #include <linux/sockios.h> |
| 19 | #include <linux/spinlock.h> |
| 20 | #include <linux/net.h> |
| 21 | #include <net/ax25.h> |
| 22 | #include <linux/inet.h> |
| 23 | #include <linux/netdevice.h> |
| 24 | #include <linux/skbuff.h> |
| 25 | #include <net/sock.h> |
| 26 | #include <asm/uaccess.h> |
| 27 | #include <asm/system.h> |
| 28 | #include <linux/fcntl.h> |
| 29 | #include <linux/mm.h> |
| 30 | #include <linux/interrupt.h> |
| 31 | |
| 32 | void ax25_ds_nr_error_recovery(ax25_cb *ax25) |
| 33 | { |
| 34 | ax25_ds_establish_data_link(ax25); |
| 35 | } |
| 36 | |
| 37 | /* |
| 38 | * dl1bke 960114: transmit I frames on DAMA poll |
| 39 | */ |
| 40 | void ax25_ds_enquiry_response(ax25_cb *ax25) |
| 41 | { |
| 42 | ax25_cb *ax25o; |
| 43 | struct hlist_node *node; |
| 44 | |
| 45 | /* Please note that neither DK4EG´s nor DG2FEF´s |
| 46 | * DAMA spec mention the following behaviour as seen |
| 47 | * with TheFirmware: |
| 48 | * |
| 49 | * DB0ACH->DL1BKE <RR C P R0> [DAMA] |
| 50 | * DL1BKE->DB0ACH <I NR=0 NS=0> |
| 51 | * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5> |
| 52 | * DL1BKE->DB0ACH <RR R F R0> |
| 53 | * |
| 54 | * The Flexnet DAMA Master implementation apparently |
| 55 | * insists on the "proper" AX.25 behaviour: |
| 56 | * |
| 57 | * DB0ACH->DL1BKE <RR C P R0> [DAMA] |
| 58 | * DL1BKE->DB0ACH <RR R F R0> |
| 59 | * DL1BKE->DB0ACH <I NR=0 NS=0> |
| 60 | * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5> |
| 61 | * |
| 62 | * Flexnet refuses to send us *any* I frame if we send |
| 63 | * a REJ in case AX25_COND_REJECT is set. It is superfluous in |
| 64 | * this mode anyway (a RR or RNR invokes the retransmission). |
| 65 | * Is this a Flexnet bug? |
| 66 | */ |
| 67 | |
| 68 | ax25_std_enquiry_response(ax25); |
| 69 | |
| 70 | if (!(ax25->condition & AX25_COND_PEER_RX_BUSY)) { |
| 71 | ax25_requeue_frames(ax25); |
| 72 | ax25_kick(ax25); |
| 73 | } |
| 74 | |
| 75 | if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2 || skb_peek(&ax25->ack_queue) != NULL) |
| 76 | ax25_ds_t1_timeout(ax25); |
| 77 | else |
| 78 | ax25->n2count = 0; |
| 79 | |
| 80 | ax25_start_t3timer(ax25); |
| 81 | ax25_ds_set_timer(ax25->ax25_dev); |
| 82 | |
| 83 | spin_lock_bh(&ax25_list_lock); |
| 84 | ax25_for_each(ax25o, node, &ax25_list) { |
| 85 | if (ax25o == ax25) |
| 86 | continue; |
| 87 | |
| 88 | if (ax25o->ax25_dev != ax25->ax25_dev) |
| 89 | continue; |
| 90 | |
| 91 | if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2) { |
| 92 | ax25_ds_t1_timeout(ax25o); |
| 93 | continue; |
| 94 | } |
| 95 | |
| 96 | if (!(ax25o->condition & AX25_COND_PEER_RX_BUSY) && ax25o->state == AX25_STATE_3) { |
| 97 | ax25_requeue_frames(ax25o); |
| 98 | ax25_kick(ax25o); |
| 99 | } |
| 100 | |
| 101 | if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2 || skb_peek(&ax25o->ack_queue) != NULL) |
| 102 | ax25_ds_t1_timeout(ax25o); |
| 103 | |
| 104 | /* do not start T3 for listening sockets (tnx DD8NE) */ |
| 105 | |
| 106 | if (ax25o->state != AX25_STATE_0) |
| 107 | ax25_start_t3timer(ax25o); |
| 108 | } |
| 109 | spin_unlock_bh(&ax25_list_lock); |
| 110 | } |
| 111 | |
| 112 | void ax25_ds_establish_data_link(ax25_cb *ax25) |
| 113 | { |
| 114 | ax25->condition &= AX25_COND_DAMA_MODE; |
| 115 | ax25->n2count = 0; |
| 116 | ax25_calculate_t1(ax25); |
| 117 | ax25_start_t1timer(ax25); |
| 118 | ax25_stop_t2timer(ax25); |
| 119 | ax25_start_t3timer(ax25); |
| 120 | } |
| 121 | |
| 122 | /* |
| 123 | * :::FIXME::: |
| 124 | * This is a kludge. Not all drivers recognize kiss commands. |
| 125 | * We need a driver level request to switch duplex mode, that does |
| 126 | * either SCC changing, PI config or KISS as required. Currently |
| 127 | * this request isn't reliable. |
| 128 | */ |
| 129 | static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char param) |
| 130 | { |
| 131 | struct sk_buff *skb; |
| 132 | unsigned char *p; |
| 133 | |
| 134 | if (ax25_dev->dev == NULL) |
| 135 | return; |
| 136 | |
| 137 | if ((skb = alloc_skb(2, GFP_ATOMIC)) == NULL) |
| 138 | return; |
| 139 | |
| 140 | skb->nh.raw = skb->data; |
| 141 | p = skb_put(skb, 2); |
| 142 | |
| 143 | *p++ = cmd; |
| 144 | *p++ = param; |
| 145 | |
| 146 | skb->dev = ax25_dev->dev; |
| 147 | skb->protocol = htons(ETH_P_AX25); |
| 148 | |
| 149 | dev_queue_xmit(skb); |
| 150 | } |
| 151 | |
| 152 | /* |
| 153 | * A nasty problem arises if we count the number of DAMA connections |
| 154 | * wrong, especially when connections on the device already existed |
| 155 | * and our network node (or the sysop) decides to turn on DAMA Master |
| 156 | * mode. We thus flag the 'real' slave connections with |
| 157 | * ax25->dama_slave=1 and look on every disconnect if still slave |
| 158 | * connections exist. |
| 159 | */ |
| 160 | static int ax25_check_dama_slave(ax25_dev *ax25_dev) |
| 161 | { |
| 162 | ax25_cb *ax25; |
| 163 | int res = 0; |
| 164 | struct hlist_node *node; |
| 165 | |
| 166 | spin_lock_bh(&ax25_list_lock); |
| 167 | ax25_for_each(ax25, node, &ax25_list) |
| 168 | if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) { |
| 169 | res = 1; |
| 170 | break; |
| 171 | } |
| 172 | spin_unlock_bh(&ax25_list_lock); |
| 173 | |
| 174 | return res; |
| 175 | } |
| 176 | |
| 177 | static void ax25_dev_dama_on(ax25_dev *ax25_dev) |
| 178 | { |
| 179 | if (ax25_dev == NULL) |
| 180 | return; |
| 181 | |
| 182 | if (ax25_dev->dama.slave == 0) |
| 183 | ax25_kiss_cmd(ax25_dev, 5, 1); |
| 184 | |
| 185 | ax25_dev->dama.slave = 1; |
| 186 | ax25_ds_set_timer(ax25_dev); |
| 187 | } |
| 188 | |
| 189 | void ax25_dev_dama_off(ax25_dev *ax25_dev) |
| 190 | { |
| 191 | if (ax25_dev == NULL) |
| 192 | return; |
| 193 | |
| 194 | if (ax25_dev->dama.slave && !ax25_check_dama_slave(ax25_dev)) { |
| 195 | ax25_kiss_cmd(ax25_dev, 5, 0); |
| 196 | ax25_dev->dama.slave = 0; |
| 197 | ax25_ds_del_timer(ax25_dev); |
| 198 | } |
| 199 | } |
| 200 | |
| 201 | void ax25_dama_on(ax25_cb *ax25) |
| 202 | { |
| 203 | ax25_dev_dama_on(ax25->ax25_dev); |
| 204 | ax25->condition |= AX25_COND_DAMA_MODE; |
| 205 | } |
| 206 | |
| 207 | void ax25_dama_off(ax25_cb *ax25) |
| 208 | { |
| 209 | ax25->condition &= ~AX25_COND_DAMA_MODE; |
| 210 | ax25_dev_dama_off(ax25->ax25_dev); |
| 211 | } |
| 212 | |