isdn: remove isdn4linux

With all isdn4linux hardware drivers gone, this is only a wrapper around
CAPI to support old user space. However, from looking at the mailing
list, it seems that the last time anyone asked about it was in 2014,
when the upgrade from a linux-2.4 installation failed, and mISDN was
suggested as a replacement.

The largest public ISDN network (Deutsche Telekom) was supposed to be
shut down 2018, which must have drastically reduced the number of legacy
installations.

When we last discussed removing i4l in 2016, Karsten Keil suggested
revisiting this in 2018. I guess this is overdue.

Link: http://listserv.isdn4linux.de/pipermail/isdn4linux/2014-October/006165.html
Link: https://patchwork.kernel.org/patch/8484861/#17900371
Link: https://listserv.isdn4linux.de/pipermail/isdn4linux/2019-April/thread.html
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 0 insertions, 332 deletions

diff --git a/drivers/isdn/i4l/isdn_x25iface.c b/drivers/isdn/i4l/isdn_x25iface.c
deleted file mode 100644
index 48bfbcb4a09d..000000000000
--- a/drivers/isdn/i4l/isdn_x25iface.c
+++ /dev/null
@@ -1,332 +0,0 @@
-/* $Id: isdn_x25iface.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
- *
- * Linux ISDN subsystem, X.25 related functions
- *
- * This software may be used and distributed according to the terms
- * of the GNU General Public License, incorporated herein by reference.
- *
- * stuff needed to support the Linux X.25 PLP code on top of devices that
- * can provide a lab_b service using the concap_proto mechanism.
- * This module supports a network interface which provides lapb_sematics
- * -- as defined in Documentation/networking/x25-iface.txt -- to
- * the upper layer and assumes that the lower layer provides a reliable
- * data link service by means of the concap_device_ops callbacks.
- *
- * Only protocol specific stuff goes here. Device specific stuff
- * goes to another -- device related -- concap_proto support source file.
- *
- */
-
-/* #include <linux/isdn.h> */
-#include <linux/netdevice.h>
-#include <linux/concap.h>
-#include <linux/slab.h>
-#include <linux/wanrouter.h>
-#include <net/x25device.h>
-#include "isdn_x25iface.h"
-
-/* for debugging messages not to cause an oops when device pointer is NULL*/
-#define MY_DEVNAME(dev)  ((dev) ? (dev)->name : "DEVICE UNSPECIFIED")
-
-
-typedef struct isdn_x25iface_proto_data {
-	int magic;
-	enum wan_states state;
-	/* Private stuff, not to be accessed via proto_data. We provide the
-	   other storage for the concap_proto instance here as well,
-	   enabling us to allocate both with just one kmalloc(): */
-	struct concap_proto priv;
-} ix25_pdata_t;
-
-
-
-/* is now in header file (extern): struct concap_proto * isdn_x25iface_proto_new(void); */
-static void isdn_x25iface_proto_del(struct concap_proto *);
-static int isdn_x25iface_proto_close(struct concap_proto *);
-static int isdn_x25iface_proto_restart(struct concap_proto *,
-				       struct net_device *,
-				       struct concap_device_ops *);
-static int isdn_x25iface_xmit(struct concap_proto *, struct sk_buff *);
-static int isdn_x25iface_receive(struct concap_proto *, struct sk_buff *);
-static int isdn_x25iface_connect_ind(struct concap_proto *);
-static int isdn_x25iface_disconn_ind(struct concap_proto *);
-
-
-static struct concap_proto_ops ix25_pops = {
-	.proto_new = &isdn_x25iface_proto_new,
-	.proto_del = &isdn_x25iface_proto_del,
-	.restart = &isdn_x25iface_proto_restart,
-	.close = &isdn_x25iface_proto_close,
-	.encap_and_xmit = &isdn_x25iface_xmit,
-	.data_ind = &isdn_x25iface_receive,
-	.connect_ind = &isdn_x25iface_connect_ind,
-	.disconn_ind = &isdn_x25iface_disconn_ind
-};
-
-/* error message helper function */
-static void illegal_state_warn(unsigned state, unsigned char firstbyte)
-{
-	printk(KERN_WARNING "isdn_x25iface: firstbyte %x illegal in"
-	       "current state %d\n", firstbyte, state);
-}
-
-/* check protocol data field for consistency */
-static int pdata_is_bad(ix25_pdata_t *pda) {
-
-	if (pda  &&  pda->magic == ISDN_X25IFACE_MAGIC) return 0;
-	printk(KERN_WARNING
-	       "isdn_x25iface_xxx: illegal pointer to proto data\n");
-	return 1;
-}
-
-/* create a new x25 interface protocol instance
- */
-struct concap_proto *isdn_x25iface_proto_new(void)
-{
-	ix25_pdata_t *tmp = kmalloc(sizeof(ix25_pdata_t), GFP_KERNEL);
-	IX25DEBUG("isdn_x25iface_proto_new\n");
-	if (tmp) {
-		tmp->magic = ISDN_X25IFACE_MAGIC;
-		tmp->state = WAN_UNCONFIGURED;
-		/* private data space used to hold the concap_proto data.
-		   Only to be accessed via the returned pointer */
-		spin_lock_init(&tmp->priv.lock);
-		tmp->priv.dops       = NULL;
-		tmp->priv.net_dev    = NULL;
-		tmp->priv.pops       = &ix25_pops;
-		tmp->priv.flags      = 0;
-		tmp->priv.proto_data = tmp;
-		return (&(tmp->priv));
-	}
-	return NULL;
-};
-
-/* close the x25iface encapsulation protocol
- */
-static int isdn_x25iface_proto_close(struct concap_proto *cprot) {
-
-	ix25_pdata_t *tmp;
-	int ret = 0;
-	ulong flags;
-
-	if (!cprot) {
-		printk(KERN_ERR "isdn_x25iface_proto_close: "
-		       "invalid concap_proto pointer\n");
-		return -1;
-	}
-	IX25DEBUG("isdn_x25iface_proto_close %s \n", MY_DEVNAME(cprot->net_dev));
-	spin_lock_irqsave(&cprot->lock, flags);
-	cprot->dops    = NULL;
-	cprot->net_dev = NULL;
-	tmp = cprot->proto_data;
-	if (pdata_is_bad(tmp)) {
-		ret = -1;
-	} else {
-		tmp->state = WAN_UNCONFIGURED;
-	}
-	spin_unlock_irqrestore(&cprot->lock, flags);
-	return ret;
-}
-
-/* Delete the x25iface encapsulation protocol instance
- */
-static void isdn_x25iface_proto_del(struct concap_proto *cprot) {
-
-	ix25_pdata_t *tmp;
-
-	IX25DEBUG("isdn_x25iface_proto_del \n");
-	if (!cprot) {
-		printk(KERN_ERR "isdn_x25iface_proto_del: "
-		       "concap_proto pointer is NULL\n");
-		return;
-	}
-	tmp = cprot->proto_data;
-	if (tmp == NULL) {
-		printk(KERN_ERR "isdn_x25iface_proto_del: inconsistent "
-		       "proto_data pointer (maybe already deleted?)\n");
-		return;
-	}
-	/* close if the protocol is still open */
-	if (cprot->dops) isdn_x25iface_proto_close(cprot);
-	/* freeing the storage should be sufficient now. But some additional
-	   settings might help to catch wild pointer bugs */
-	tmp->magic = 0;
-	cprot->proto_data = NULL;
-
-	kfree(tmp);
-	return;
-}
-
-/* (re-)initialize the data structures for x25iface encapsulation
- */
-static int isdn_x25iface_proto_restart(struct concap_proto *cprot,
-				       struct net_device *ndev,
-				       struct concap_device_ops *dops)
-{
-	ix25_pdata_t *pda = cprot->proto_data;
-	ulong flags;
-
-	IX25DEBUG("isdn_x25iface_proto_restart %s \n", MY_DEVNAME(ndev));
-
-	if (pdata_is_bad(pda)) return -1;
-
-	if (!(dops && dops->data_req && dops->connect_req
-	      && dops->disconn_req)) {
-		printk(KERN_WARNING "isdn_x25iface_restart: required dops"
-		       " missing\n");
-		isdn_x25iface_proto_close(cprot);
-		return -1;
-	}
-	spin_lock_irqsave(&cprot->lock, flags);
-	cprot->net_dev = ndev;
-	cprot->pops = &ix25_pops;
-	cprot->dops = dops;
-	pda->state = WAN_DISCONNECTED;
-	spin_unlock_irqrestore(&cprot->lock, flags);
-	return 0;
-}
-
-/* deliver a dl_data frame received from i4l HL driver to the network layer
- */
-static int isdn_x25iface_receive(struct concap_proto *cprot, struct sk_buff *skb)
-{
-	IX25DEBUG("isdn_x25iface_receive %s \n", MY_DEVNAME(cprot->net_dev));
-	if (((ix25_pdata_t *)(cprot->proto_data))
-	    ->state == WAN_CONNECTED) {
-		if (skb_push(skb, 1)) {
-			skb->data[0] = X25_IFACE_DATA;
-			skb->protocol = x25_type_trans(skb, cprot->net_dev);
-			netif_rx(skb);
-			return 0;
-		}
-	}
-	printk(KERN_WARNING "isdn_x25iface_receive %s: not connected, skb dropped\n", MY_DEVNAME(cprot->net_dev));
-	dev_kfree_skb(skb);
-	return -1;
-}
-
-/* a connection set up is indicated by lower layer
- */
-static int isdn_x25iface_connect_ind(struct concap_proto *cprot)
-{
-	struct sk_buff *skb;
-	enum wan_states *state_p
-		= &(((ix25_pdata_t *)(cprot->proto_data))->state);
-	IX25DEBUG("isdn_x25iface_connect_ind %s \n"
-		  , MY_DEVNAME(cprot->net_dev));
-	if (*state_p == WAN_UNCONFIGURED) {
-		printk(KERN_WARNING
-		       "isdn_x25iface_connect_ind while unconfigured %s\n"
-		       , MY_DEVNAME(cprot->net_dev));
-		return -1;
-	}
-	*state_p = WAN_CONNECTED;
-
-	skb = dev_alloc_skb(1);
-	if (skb) {
-		skb_put_u8(skb, X25_IFACE_CONNECT);
-		skb->protocol = x25_type_trans(skb, cprot->net_dev);
-		netif_rx(skb);
-		return 0;
-	} else {
-		printk(KERN_WARNING "isdn_x25iface_connect_ind: "
-		       " out of memory -- disconnecting\n");
-		cprot->dops->disconn_req(cprot);
-		return -1;
-	}
-}
-
-/* a disconnect is indicated by lower layer
- */
-static int isdn_x25iface_disconn_ind(struct concap_proto *cprot)
-{
-	struct sk_buff *skb;
-	enum wan_states *state_p
-		= &(((ix25_pdata_t *)(cprot->proto_data))->state);
-	IX25DEBUG("isdn_x25iface_disconn_ind %s \n", MY_DEVNAME(cprot->net_dev));
-	if (*state_p == WAN_UNCONFIGURED) {
-		printk(KERN_WARNING
-		       "isdn_x25iface_disconn_ind while unconfigured\n");
-		return -1;
-	}
-	if (!cprot->net_dev) return -1;
-	*state_p = WAN_DISCONNECTED;
-	skb = dev_alloc_skb(1);
-	if (skb) {
-		skb_put_u8(skb, X25_IFACE_DISCONNECT);
-		skb->protocol = x25_type_trans(skb, cprot->net_dev);
-		netif_rx(skb);
-		return 0;
-	} else {
-		printk(KERN_WARNING "isdn_x25iface_disconn_ind:"
-		       " out of memory\n");
-		return -1;
-	}
-}
-
-/* process a frame handed over to us from linux network layer. First byte
-   semantics as defined in Documentation/networking/x25-iface.txt
-*/
-static int isdn_x25iface_xmit(struct concap_proto *cprot, struct sk_buff *skb)
-{
-	unsigned char firstbyte = skb->data[0];
-	enum wan_states *state = &((ix25_pdata_t *)cprot->proto_data)->state;
-	int ret = 0;
-	IX25DEBUG("isdn_x25iface_xmit: %s first=%x state=%d\n",
-		  MY_DEVNAME(cprot->net_dev), firstbyte, *state);
-	switch (firstbyte) {
-	case X25_IFACE_DATA:
-		if (*state == WAN_CONNECTED) {
-			skb_pull(skb, 1);
-			netif_trans_update(cprot->net_dev);
-			ret = (cprot->dops->data_req(cprot, skb));
-			/* prepare for future retransmissions */
-			if (ret) skb_push(skb, 1);
-			return ret;
-		}
-		illegal_state_warn(*state, firstbyte);
-		break;
-	case X25_IFACE_CONNECT:
-		if (*state == WAN_DISCONNECTED) {
-			*state = WAN_CONNECTING;
-			ret = cprot->dops->connect_req(cprot);
-			if (ret) {
-				/* reset state and notify upper layer about
-				 * immidiatly failed attempts */
-				isdn_x25iface_disconn_ind(cprot);
-			}
-		} else {
-			illegal_state_warn(*state, firstbyte);
-		}
-		break;
-	case X25_IFACE_DISCONNECT:
-		switch (*state) {
-		case WAN_DISCONNECTED:
-			/* Should not happen. However, give upper layer a
-			   chance to recover from inconstistency  but don't
-			   trust the lower layer sending the disconn_confirm
-			   when already disconnected */
-			printk(KERN_WARNING "isdn_x25iface_xmit: disconnect "
-			       " requested while disconnected\n");
-			isdn_x25iface_disconn_ind(cprot);
-			break; /* prevent infinite loops */
-		case WAN_CONNECTING:
-		case WAN_CONNECTED:
-			*state = WAN_DISCONNECTED;
-			cprot->dops->disconn_req(cprot);
-			break;
-		default:
-			illegal_state_warn(*state, firstbyte);
-		}
-		break;
-	case X25_IFACE_PARAMS:
-		printk(KERN_WARNING "isdn_x25iface_xmit: setting of lapb"
-		       " options not yet supported\n");
-		break;
-	default:
-		printk(KERN_WARNING "isdn_x25iface_xmit: frame with illegal"
-		       " first byte %x ignored:\n", firstbyte);
-	}
-	dev_kfree_skb(skb);
-	return 0;
-}