change system file

hc

2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771

 kernel/drivers/net/wan/hdlc_x25.c
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@@ -1,12 +1,9 @@
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+// 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 <khc@pm.waw.pl>
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- *
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- * This program is free software; you can redistribute it and/or modify it
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- * under the terms of version 2 of the GNU General Public License
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- * as published by the Free Software Foundation.
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  */
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8
 
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 #include <linux/errno.h>
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@@ -24,7 +21,18 @@
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 #include <linux/skbuff.h>
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 #include <net/x25device.h>
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23
 
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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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+
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 static int x25_ioctl(struct net_device *dev, struct ifreq *ifr);
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+
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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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38
 
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@@ -65,10 +73,13 @@
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 {
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 	unsigned char *ptr;
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-	skb_push(skb, 1);
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-
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-	if (skb_cow(skb, 1))
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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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+
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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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@@ -82,6 +93,13 @@
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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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+
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+	skb_reset_network_header(skb);
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+	skb->protocol = hdlc_type_trans(skb, dev);
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+
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+	if (dev_nit_active(dev))
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+		dev_queue_xmit_nit(skb, dev);
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+
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 	hdlc->xmit(skb, dev); /* Ignore return value :-( */
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 }
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@@ -89,15 +107,32 @@
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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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-	/* X.25 to LAPB */
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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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+
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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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@@ -126,6 +161,7 @@
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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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@@ -134,7 +170,6 @@
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170
 
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 static int x25_open(struct net_device *dev)
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 {
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-	int result;
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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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@@ -143,10 +178,38 @@
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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 result;
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+		return -ENOMEM;
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+
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+	result = lapb_getparms(dev, &params);
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+	if (result != LAPB_OK)
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+		return -EINVAL;
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+
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+	if (state(hdlc)->settings.dce)
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+		params.mode = params.mode | LAPB_DCE;
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+
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+	if (state(hdlc)->settings.modulo == 128)
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+		params.mode = params.mode | LAPB_EXTENDED;
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+
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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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+
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+	result = lapb_setparms(dev, &params);
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+	if (result != LAPB_OK)
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+		return -EINVAL;
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+
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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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+
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 	return 0;
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 }
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@@ -154,6 +217,13 @@
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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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+
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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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+
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 	lapb_unregister(dev);
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 }
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@@ -162,15 +232,28 @@
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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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-	if (lapb_data_received(dev, skb) == LAPB_OK)
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-		return NET_RX_SUCCESS;
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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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+
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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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@@ -189,7 +272,10 @@
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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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@@ -197,7 +283,13 @@
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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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-		return 0; /* return protocol only, no settable parameters */
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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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@@ -206,12 +298,57 @@
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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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+
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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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+
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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, 0)))
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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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+
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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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+
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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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+
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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);