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| 1 | +// SPDX-License-Identifier: GPL-2.0-only |
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1 | 2 | /* |
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2 | 3 | * Generic HDLC support routines for Linux |
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3 | 4 | * X.25 support |
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4 | 5 | * |
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5 | 6 | * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl> |
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6 | | - * |
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7 | | - * This program is free software; you can redistribute it and/or modify it |
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8 | | - * under the terms of version 2 of the GNU General Public License |
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9 | | - * as published by the Free Software Foundation. |
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10 | 7 | */ |
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11 | 8 | |
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12 | 9 | #include <linux/errno.h> |
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.. | .. |
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24 | 21 | #include <linux/skbuff.h> |
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25 | 22 | #include <net/x25device.h> |
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26 | 23 | |
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| 24 | +struct x25_state { |
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| 25 | + x25_hdlc_proto settings; |
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| 26 | + bool up; |
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| 27 | + spinlock_t up_lock; /* Protects "up" */ |
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| 28 | +}; |
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| 29 | + |
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27 | 30 | static int x25_ioctl(struct net_device *dev, struct ifreq *ifr); |
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| 31 | + |
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| 32 | +static struct x25_state *state(hdlc_device *hdlc) |
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| 33 | +{ |
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| 34 | + return hdlc->state; |
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| 35 | +} |
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28 | 36 | |
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29 | 37 | /* These functions are callbacks called by LAPB layer */ |
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30 | 38 | |
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.. | .. |
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65 | 73 | { |
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66 | 74 | unsigned char *ptr; |
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67 | 75 | |
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68 | | - skb_push(skb, 1); |
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69 | | - |
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70 | | - if (skb_cow(skb, 1)) |
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| 76 | + if (skb_cow(skb, 1)) { |
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| 77 | + kfree_skb(skb); |
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71 | 78 | return NET_RX_DROP; |
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| 79 | + } |
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| 80 | + |
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| 81 | + skb_push(skb, 1); |
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| 82 | + skb_reset_network_header(skb); |
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72 | 83 | |
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73 | 84 | ptr = skb->data; |
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74 | 85 | *ptr = X25_IFACE_DATA; |
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.. | .. |
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82 | 93 | static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb) |
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83 | 94 | { |
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84 | 95 | hdlc_device *hdlc = dev_to_hdlc(dev); |
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| 96 | + |
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| 97 | + skb_reset_network_header(skb); |
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| 98 | + skb->protocol = hdlc_type_trans(skb, dev); |
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| 99 | + |
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| 100 | + if (dev_nit_active(dev)) |
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| 101 | + dev_queue_xmit_nit(skb, dev); |
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| 102 | + |
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85 | 103 | hdlc->xmit(skb, dev); /* Ignore return value :-( */ |
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86 | 104 | } |
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87 | 105 | |
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.. | .. |
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89 | 107 | |
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90 | 108 | static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev) |
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91 | 109 | { |
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| 110 | + hdlc_device *hdlc = dev_to_hdlc(dev); |
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| 111 | + struct x25_state *x25st = state(hdlc); |
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92 | 112 | int result; |
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93 | 113 | |
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| 114 | + /* There should be a pseudo header of 1 byte added by upper layers. |
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| 115 | + * Check to make sure it is there before reading it. |
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| 116 | + */ |
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| 117 | + if (skb->len < 1) { |
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| 118 | + kfree_skb(skb); |
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| 119 | + return NETDEV_TX_OK; |
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| 120 | + } |
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94 | 121 | |
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95 | | - /* X.25 to LAPB */ |
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| 122 | + spin_lock_bh(&x25st->up_lock); |
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| 123 | + if (!x25st->up) { |
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| 124 | + spin_unlock_bh(&x25st->up_lock); |
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| 125 | + kfree_skb(skb); |
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| 126 | + return NETDEV_TX_OK; |
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| 127 | + } |
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| 128 | + |
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96 | 129 | switch (skb->data[0]) { |
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97 | 130 | case X25_IFACE_DATA: /* Data to be transmitted */ |
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98 | 131 | skb_pull(skb, 1); |
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| 132 | + skb_reset_network_header(skb); |
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99 | 133 | if ((result = lapb_data_request(dev, skb)) != LAPB_OK) |
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100 | 134 | dev_kfree_skb(skb); |
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| 135 | + spin_unlock_bh(&x25st->up_lock); |
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101 | 136 | return NETDEV_TX_OK; |
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102 | 137 | |
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103 | 138 | case X25_IFACE_CONNECT: |
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.. | .. |
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126 | 161 | break; |
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127 | 162 | } |
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128 | 163 | |
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| 164 | + spin_unlock_bh(&x25st->up_lock); |
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129 | 165 | dev_kfree_skb(skb); |
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130 | 166 | return NETDEV_TX_OK; |
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131 | 167 | } |
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.. | .. |
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134 | 170 | |
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135 | 171 | static int x25_open(struct net_device *dev) |
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136 | 172 | { |
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137 | | - int result; |
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138 | 173 | static const struct lapb_register_struct cb = { |
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139 | 174 | .connect_confirmation = x25_connected, |
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140 | 175 | .connect_indication = x25_connected, |
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.. | .. |
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143 | 178 | .data_indication = x25_data_indication, |
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144 | 179 | .data_transmit = x25_data_transmit, |
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145 | 180 | }; |
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| 181 | + hdlc_device *hdlc = dev_to_hdlc(dev); |
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| 182 | + struct x25_state *x25st = state(hdlc); |
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| 183 | + struct lapb_parms_struct params; |
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| 184 | + int result; |
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146 | 185 | |
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147 | 186 | result = lapb_register(dev, &cb); |
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148 | 187 | if (result != LAPB_OK) |
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149 | | - return result; |
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| 188 | + return -ENOMEM; |
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| 189 | + |
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| 190 | + result = lapb_getparms(dev, ¶ms); |
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| 191 | + if (result != LAPB_OK) |
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| 192 | + return -EINVAL; |
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| 193 | + |
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| 194 | + if (state(hdlc)->settings.dce) |
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| 195 | + params.mode = params.mode | LAPB_DCE; |
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| 196 | + |
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| 197 | + if (state(hdlc)->settings.modulo == 128) |
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| 198 | + params.mode = params.mode | LAPB_EXTENDED; |
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| 199 | + |
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| 200 | + params.window = state(hdlc)->settings.window; |
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| 201 | + params.t1 = state(hdlc)->settings.t1; |
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| 202 | + params.t2 = state(hdlc)->settings.t2; |
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| 203 | + params.n2 = state(hdlc)->settings.n2; |
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| 204 | + |
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| 205 | + result = lapb_setparms(dev, ¶ms); |
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| 206 | + if (result != LAPB_OK) |
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| 207 | + return -EINVAL; |
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| 208 | + |
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| 209 | + spin_lock_bh(&x25st->up_lock); |
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| 210 | + x25st->up = true; |
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| 211 | + spin_unlock_bh(&x25st->up_lock); |
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| 212 | + |
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150 | 213 | return 0; |
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151 | 214 | } |
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152 | 215 | |
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.. | .. |
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154 | 217 | |
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155 | 218 | static void x25_close(struct net_device *dev) |
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156 | 219 | { |
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| 220 | + hdlc_device *hdlc = dev_to_hdlc(dev); |
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| 221 | + struct x25_state *x25st = state(hdlc); |
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| 222 | + |
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| 223 | + spin_lock_bh(&x25st->up_lock); |
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| 224 | + x25st->up = false; |
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| 225 | + spin_unlock_bh(&x25st->up_lock); |
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| 226 | + |
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157 | 227 | lapb_unregister(dev); |
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158 | 228 | } |
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159 | 229 | |
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.. | .. |
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162 | 232 | static int x25_rx(struct sk_buff *skb) |
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163 | 233 | { |
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164 | 234 | struct net_device *dev = skb->dev; |
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| 235 | + hdlc_device *hdlc = dev_to_hdlc(dev); |
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| 236 | + struct x25_state *x25st = state(hdlc); |
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165 | 237 | |
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166 | 238 | if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) { |
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167 | 239 | dev->stats.rx_dropped++; |
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168 | 240 | return NET_RX_DROP; |
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169 | 241 | } |
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170 | 242 | |
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171 | | - if (lapb_data_received(dev, skb) == LAPB_OK) |
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172 | | - return NET_RX_SUCCESS; |
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| 243 | + spin_lock_bh(&x25st->up_lock); |
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| 244 | + if (!x25st->up) { |
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| 245 | + spin_unlock_bh(&x25st->up_lock); |
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| 246 | + kfree_skb(skb); |
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| 247 | + dev->stats.rx_dropped++; |
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| 248 | + return NET_RX_DROP; |
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| 249 | + } |
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173 | 250 | |
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| 251 | + if (lapb_data_received(dev, skb) == LAPB_OK) { |
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| 252 | + spin_unlock_bh(&x25st->up_lock); |
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| 253 | + return NET_RX_SUCCESS; |
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| 254 | + } |
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| 255 | + |
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| 256 | + spin_unlock_bh(&x25st->up_lock); |
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174 | 257 | dev->stats.rx_errors++; |
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175 | 258 | dev_kfree_skb_any(skb); |
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176 | 259 | return NET_RX_DROP; |
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.. | .. |
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189 | 272 | |
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190 | 273 | static int x25_ioctl(struct net_device *dev, struct ifreq *ifr) |
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191 | 274 | { |
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| 275 | + x25_hdlc_proto __user *x25_s = ifr->ifr_settings.ifs_ifsu.x25; |
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| 276 | + const size_t size = sizeof(x25_hdlc_proto); |
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192 | 277 | hdlc_device *hdlc = dev_to_hdlc(dev); |
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| 278 | + x25_hdlc_proto new_settings; |
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193 | 279 | int result; |
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194 | 280 | |
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195 | 281 | switch (ifr->ifr_settings.type) { |
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.. | .. |
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197 | 283 | if (dev_to_hdlc(dev)->proto != &proto) |
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198 | 284 | return -EINVAL; |
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199 | 285 | ifr->ifr_settings.type = IF_PROTO_X25; |
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200 | | - return 0; /* return protocol only, no settable parameters */ |
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| 286 | + if (ifr->ifr_settings.size < size) { |
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| 287 | + ifr->ifr_settings.size = size; /* data size wanted */ |
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| 288 | + return -ENOBUFS; |
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| 289 | + } |
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| 290 | + if (copy_to_user(x25_s, &state(hdlc)->settings, size)) |
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| 291 | + return -EFAULT; |
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| 292 | + return 0; |
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201 | 293 | |
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202 | 294 | case IF_PROTO_X25: |
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203 | 295 | if (!capable(CAP_NET_ADMIN)) |
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.. | .. |
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206 | 298 | if (dev->flags & IFF_UP) |
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207 | 299 | return -EBUSY; |
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208 | 300 | |
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| 301 | + /* backward compatibility */ |
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| 302 | + if (ifr->ifr_settings.size == 0) { |
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| 303 | + new_settings.dce = 0; |
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| 304 | + new_settings.modulo = 8; |
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| 305 | + new_settings.window = 7; |
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| 306 | + new_settings.t1 = 3; |
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| 307 | + new_settings.t2 = 1; |
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| 308 | + new_settings.n2 = 10; |
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| 309 | + } |
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| 310 | + else { |
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| 311 | + if (copy_from_user(&new_settings, x25_s, size)) |
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| 312 | + return -EFAULT; |
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| 313 | + |
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| 314 | + if ((new_settings.dce != 0 && |
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| 315 | + new_settings.dce != 1) || |
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| 316 | + (new_settings.modulo != 8 && |
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| 317 | + new_settings.modulo != 128) || |
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| 318 | + new_settings.window < 1 || |
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| 319 | + (new_settings.modulo == 8 && |
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| 320 | + new_settings.window > 7) || |
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| 321 | + (new_settings.modulo == 128 && |
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| 322 | + new_settings.window > 127) || |
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| 323 | + new_settings.t1 < 1 || |
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| 324 | + new_settings.t1 > 255 || |
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| 325 | + new_settings.t2 < 1 || |
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| 326 | + new_settings.t2 > 255 || |
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| 327 | + new_settings.n2 < 1 || |
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| 328 | + new_settings.n2 > 255) |
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| 329 | + return -EINVAL; |
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| 330 | + } |
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| 331 | + |
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209 | 332 | result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT); |
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210 | 333 | if (result) |
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211 | 334 | return result; |
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212 | 335 | |
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213 | | - if ((result = attach_hdlc_protocol(dev, &proto, 0))) |
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| 336 | + if ((result = attach_hdlc_protocol(dev, &proto, |
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| 337 | + sizeof(struct x25_state)))) |
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214 | 338 | return result; |
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| 339 | + |
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| 340 | + memcpy(&state(hdlc)->settings, &new_settings, size); |
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| 341 | + state(hdlc)->up = false; |
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| 342 | + spin_lock_init(&state(hdlc)->up_lock); |
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| 343 | + |
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| 344 | + /* There's no header_ops so hard_header_len should be 0. */ |
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| 345 | + dev->hard_header_len = 0; |
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| 346 | + /* When transmitting data: |
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| 347 | + * first we'll remove a pseudo header of 1 byte, |
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| 348 | + * then we'll prepend an LAPB header of at most 3 bytes. |
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| 349 | + */ |
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| 350 | + dev->needed_headroom = 3 - 1; |
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| 351 | + |
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215 | 352 | dev->type = ARPHRD_X25; |
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216 | 353 | call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev); |
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217 | 354 | netif_dormant_off(dev); |
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