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381 lines
8.2 KiB
381 lines
8.2 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Generic HDLC support routines for Linux |
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* X.25 support |
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* |
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* Copyright (C) 1999 - 2006 Krzysztof Halasa <[email protected]> |
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*/ |
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#include <linux/errno.h> |
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#include <linux/gfp.h> |
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#include <linux/hdlc.h> |
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#include <linux/if_arp.h> |
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#include <linux/inetdevice.h> |
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#include <linux/init.h> |
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#include <linux/kernel.h> |
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#include <linux/lapb.h> |
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#include <linux/module.h> |
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#include <linux/pkt_sched.h> |
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#include <linux/poll.h> |
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#include <linux/rtnetlink.h> |
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#include <linux/skbuff.h> |
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#include <net/x25device.h> |
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struct x25_state { |
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x25_hdlc_proto settings; |
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bool up; |
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spinlock_t up_lock; /* Protects "up" */ |
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}; |
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static int x25_ioctl(struct net_device *dev, struct ifreq *ifr); |
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static struct x25_state *state(hdlc_device *hdlc) |
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{ |
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return hdlc->state; |
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} |
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/* These functions are callbacks called by LAPB layer */ |
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static void x25_connect_disconnect(struct net_device *dev, int reason, int code) |
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{ |
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struct sk_buff *skb; |
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unsigned char *ptr; |
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if ((skb = dev_alloc_skb(1)) == NULL) { |
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netdev_err(dev, "out of memory\n"); |
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return; |
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} |
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ptr = skb_put(skb, 1); |
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*ptr = code; |
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skb->protocol = x25_type_trans(skb, dev); |
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netif_rx(skb); |
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} |
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static void x25_connected(struct net_device *dev, int reason) |
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{ |
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x25_connect_disconnect(dev, reason, X25_IFACE_CONNECT); |
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} |
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static void x25_disconnected(struct net_device *dev, int reason) |
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{ |
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x25_connect_disconnect(dev, reason, X25_IFACE_DISCONNECT); |
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} |
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static int x25_data_indication(struct net_device *dev, struct sk_buff *skb) |
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{ |
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unsigned char *ptr; |
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if (skb_cow(skb, 1)) { |
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kfree_skb(skb); |
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return NET_RX_DROP; |
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} |
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skb_push(skb, 1); |
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skb_reset_network_header(skb); |
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ptr = skb->data; |
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*ptr = X25_IFACE_DATA; |
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skb->protocol = x25_type_trans(skb, dev); |
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return netif_rx(skb); |
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} |
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static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb) |
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{ |
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hdlc_device *hdlc = dev_to_hdlc(dev); |
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skb_reset_network_header(skb); |
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skb->protocol = hdlc_type_trans(skb, dev); |
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if (dev_nit_active(dev)) |
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dev_queue_xmit_nit(skb, dev); |
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hdlc->xmit(skb, dev); /* Ignore return value :-( */ |
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} |
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static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev) |
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{ |
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hdlc_device *hdlc = dev_to_hdlc(dev); |
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struct x25_state *x25st = state(hdlc); |
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int result; |
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/* There should be a pseudo header of 1 byte added by upper layers. |
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* Check to make sure it is there before reading it. |
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*/ |
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if (skb->len < 1) { |
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kfree_skb(skb); |
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return NETDEV_TX_OK; |
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} |
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spin_lock_bh(&x25st->up_lock); |
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if (!x25st->up) { |
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spin_unlock_bh(&x25st->up_lock); |
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kfree_skb(skb); |
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return NETDEV_TX_OK; |
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} |
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switch (skb->data[0]) { |
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case X25_IFACE_DATA: /* Data to be transmitted */ |
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skb_pull(skb, 1); |
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skb_reset_network_header(skb); |
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if ((result = lapb_data_request(dev, skb)) != LAPB_OK) |
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dev_kfree_skb(skb); |
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spin_unlock_bh(&x25st->up_lock); |
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return NETDEV_TX_OK; |
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case X25_IFACE_CONNECT: |
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if ((result = lapb_connect_request(dev))!= LAPB_OK) { |
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if (result == LAPB_CONNECTED) |
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/* Send connect confirm. msg to level 3 */ |
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x25_connected(dev, 0); |
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else |
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netdev_err(dev, "LAPB connect request failed, error code = %i\n", |
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result); |
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} |
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break; |
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case X25_IFACE_DISCONNECT: |
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if ((result = lapb_disconnect_request(dev)) != LAPB_OK) { |
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if (result == LAPB_NOTCONNECTED) |
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/* Send disconnect confirm. msg to level 3 */ |
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x25_disconnected(dev, 0); |
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else |
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netdev_err(dev, "LAPB disconnect request failed, error code = %i\n", |
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result); |
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} |
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break; |
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default: /* to be defined */ |
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break; |
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} |
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spin_unlock_bh(&x25st->up_lock); |
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dev_kfree_skb(skb); |
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return NETDEV_TX_OK; |
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} |
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static int x25_open(struct net_device *dev) |
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{ |
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static const struct lapb_register_struct cb = { |
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.connect_confirmation = x25_connected, |
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.connect_indication = x25_connected, |
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.disconnect_confirmation = x25_disconnected, |
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.disconnect_indication = x25_disconnected, |
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.data_indication = x25_data_indication, |
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.data_transmit = x25_data_transmit, |
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}; |
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hdlc_device *hdlc = dev_to_hdlc(dev); |
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struct x25_state *x25st = state(hdlc); |
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struct lapb_parms_struct params; |
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int result; |
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result = lapb_register(dev, &cb); |
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if (result != LAPB_OK) |
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return -ENOMEM; |
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result = lapb_getparms(dev, ¶ms); |
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if (result != LAPB_OK) |
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return -EINVAL; |
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if (state(hdlc)->settings.dce) |
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params.mode = params.mode | LAPB_DCE; |
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if (state(hdlc)->settings.modulo == 128) |
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params.mode = params.mode | LAPB_EXTENDED; |
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params.window = state(hdlc)->settings.window; |
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params.t1 = state(hdlc)->settings.t1; |
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params.t2 = state(hdlc)->settings.t2; |
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params.n2 = state(hdlc)->settings.n2; |
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result = lapb_setparms(dev, ¶ms); |
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if (result != LAPB_OK) |
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return -EINVAL; |
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spin_lock_bh(&x25st->up_lock); |
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x25st->up = true; |
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spin_unlock_bh(&x25st->up_lock); |
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return 0; |
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} |
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static void x25_close(struct net_device *dev) |
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{ |
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hdlc_device *hdlc = dev_to_hdlc(dev); |
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struct x25_state *x25st = state(hdlc); |
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spin_lock_bh(&x25st->up_lock); |
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x25st->up = false; |
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spin_unlock_bh(&x25st->up_lock); |
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lapb_unregister(dev); |
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} |
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static int x25_rx(struct sk_buff *skb) |
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{ |
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struct net_device *dev = skb->dev; |
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hdlc_device *hdlc = dev_to_hdlc(dev); |
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struct x25_state *x25st = state(hdlc); |
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if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) { |
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dev->stats.rx_dropped++; |
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return NET_RX_DROP; |
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} |
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spin_lock_bh(&x25st->up_lock); |
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if (!x25st->up) { |
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spin_unlock_bh(&x25st->up_lock); |
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kfree_skb(skb); |
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dev->stats.rx_dropped++; |
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return NET_RX_DROP; |
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} |
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if (lapb_data_received(dev, skb) == LAPB_OK) { |
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spin_unlock_bh(&x25st->up_lock); |
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return NET_RX_SUCCESS; |
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} |
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spin_unlock_bh(&x25st->up_lock); |
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dev->stats.rx_errors++; |
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dev_kfree_skb_any(skb); |
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return NET_RX_DROP; |
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} |
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static struct hdlc_proto proto = { |
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.open = x25_open, |
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.close = x25_close, |
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.ioctl = x25_ioctl, |
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.netif_rx = x25_rx, |
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.xmit = x25_xmit, |
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.module = THIS_MODULE, |
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}; |
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static int x25_ioctl(struct net_device *dev, struct ifreq *ifr) |
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{ |
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x25_hdlc_proto __user *x25_s = ifr->ifr_settings.ifs_ifsu.x25; |
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const size_t size = sizeof(x25_hdlc_proto); |
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hdlc_device *hdlc = dev_to_hdlc(dev); |
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x25_hdlc_proto new_settings; |
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int result; |
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switch (ifr->ifr_settings.type) { |
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case IF_GET_PROTO: |
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if (dev_to_hdlc(dev)->proto != &proto) |
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return -EINVAL; |
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ifr->ifr_settings.type = IF_PROTO_X25; |
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if (ifr->ifr_settings.size < size) { |
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ifr->ifr_settings.size = size; /* data size wanted */ |
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return -ENOBUFS; |
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} |
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if (copy_to_user(x25_s, &state(hdlc)->settings, size)) |
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return -EFAULT; |
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return 0; |
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case IF_PROTO_X25: |
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if (!capable(CAP_NET_ADMIN)) |
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return -EPERM; |
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if (dev->flags & IFF_UP) |
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return -EBUSY; |
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/* backward compatibility */ |
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if (ifr->ifr_settings.size == 0) { |
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new_settings.dce = 0; |
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new_settings.modulo = 8; |
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new_settings.window = 7; |
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new_settings.t1 = 3; |
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new_settings.t2 = 1; |
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new_settings.n2 = 10; |
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} |
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else { |
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if (copy_from_user(&new_settings, x25_s, size)) |
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return -EFAULT; |
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if ((new_settings.dce != 0 && |
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new_settings.dce != 1) || |
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(new_settings.modulo != 8 && |
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new_settings.modulo != 128) || |
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new_settings.window < 1 || |
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(new_settings.modulo == 8 && |
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new_settings.window > 7) || |
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(new_settings.modulo == 128 && |
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new_settings.window > 127) || |
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new_settings.t1 < 1 || |
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new_settings.t1 > 255 || |
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new_settings.t2 < 1 || |
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new_settings.t2 > 255 || |
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new_settings.n2 < 1 || |
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new_settings.n2 > 255) |
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return -EINVAL; |
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} |
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result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT); |
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if (result) |
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return result; |
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if ((result = attach_hdlc_protocol(dev, &proto, |
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sizeof(struct x25_state)))) |
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return result; |
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memcpy(&state(hdlc)->settings, &new_settings, size); |
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state(hdlc)->up = false; |
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spin_lock_init(&state(hdlc)->up_lock); |
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/* There's no header_ops so hard_header_len should be 0. */ |
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dev->hard_header_len = 0; |
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/* When transmitting data: |
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* first we'll remove a pseudo header of 1 byte, |
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* then we'll prepend an LAPB header of at most 3 bytes. |
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*/ |
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dev->needed_headroom = 3 - 1; |
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dev->type = ARPHRD_X25; |
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call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev); |
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netif_dormant_off(dev); |
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return 0; |
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} |
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return -EINVAL; |
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} |
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static int __init mod_init(void) |
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{ |
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register_hdlc_protocol(&proto); |
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return 0; |
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} |
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static void __exit mod_exit(void) |
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{ |
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unregister_hdlc_protocol(&proto); |
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} |
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module_init(mod_init); |
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module_exit(mod_exit); |
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MODULE_AUTHOR("Krzysztof Halasa <[email protected]>"); |
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MODULE_DESCRIPTION("X.25 protocol support for generic HDLC"); |
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MODULE_LICENSE("GPL v2");
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