net: remove ISDN subsystem and Bluetooth CMTP

Remove the ISDN (mISDN, CAPI) subsystem and Bluetooth CMTP protocol
from the kernel tree.

ISDN is a pretty old technology and it's unclear whether anyone still
uses it. I went over the last few years of git history and all the
commits are either tree-wide conversions or syzbot/static analyzer
fixes.

When we discussed removal in the past IIRC there were some concerns
about ISDN still being used in parts of Germany. Unfortunately, the
code base is quite old, none of the current maintainers are familiar
with it and AI tools will have a field day finding bugs here.

Delete this code and preserve it in an out-of-tree repository
for any remaining users:
https://github.com/linux-netdev/mod-orphan

UAPI constants AF_ISDN/PF_ISDN and the SELinux isdn_socket class
are preserved for ABI stability, but the rest of uAPI is removed.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260421022108.1299678-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 0 insertions, 134 deletions

diff --git a/include/uapi/linux/capi.h b/include/uapi/linux/capi.h
deleted file mode 100644
index 31f946f8a88d..000000000000
--- a/include/uapi/linux/capi.h
+++ /dev/null
@@ -1,134 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/* $Id: capi.h,v 1.4.6.1 2001/09/23 22:25:05 kai Exp $
- * 
- * CAPI 2.0 Interface for Linux
- * 
- * Copyright 1997 by Carsten Paeth (calle@calle.in-berlin.de)
- * 
- * This software may be used and distributed according to the terms
- * of the GNU General Public License, incorporated herein by reference.
- *
- */
-
-#ifndef __LINUX_CAPI_H__
-#define __LINUX_CAPI_H__
-
-#include <linux/types.h>
-#include <linux/ioctl.h>
-#ifndef __KERNEL__
-#include <linux/kernelcapi.h>
-#endif
-
-/*
- * CAPI_REGISTER
- */
-
-typedef struct capi_register_params {	/* CAPI_REGISTER */
-	__u32 level3cnt;	/* No. of simulatneous user data connections */
-	__u32 datablkcnt;	/* No. of buffered data messages */
-	__u32 datablklen;	/* Size of buffered data messages */
-} capi_register_params;
-
-#define	CAPI_REGISTER	_IOW('C',0x01,struct capi_register_params)
-
-/*
- * CAPI_GET_MANUFACTURER
- */
-
-#define CAPI_MANUFACTURER_LEN		64
-
-#define	CAPI_GET_MANUFACTURER	_IOWR('C',0x06,int)	/* broken: wanted size 64 (CAPI_MANUFACTURER_LEN) */
-
-/*
- * CAPI_GET_VERSION
- */
-
-typedef struct capi_version {
-	__u32 majorversion;
-	__u32 minorversion;
-	__u32 majormanuversion;
-	__u32 minormanuversion;
-} capi_version;
-
-#define CAPI_GET_VERSION	_IOWR('C',0x07,struct capi_version)
-
-/*
- * CAPI_GET_SERIAL
- */
-
-#define CAPI_SERIAL_LEN		8
-#define CAPI_GET_SERIAL		_IOWR('C',0x08,int)	/* broken: wanted size 8 (CAPI_SERIAL_LEN) */
-
-/*
- * CAPI_GET_PROFILE
- */
-
-typedef struct capi_profile {
-	__u16 ncontroller;	/* number of installed controller */
-	__u16 nbchannel;	/* number of B-Channels */
-	__u32 goptions;		/* global options */
-	__u32 support1;		/* B1 protocols support */
-	__u32 support2;		/* B2 protocols support */
-	__u32 support3;		/* B3 protocols support */
-	__u32 reserved[6];	/* reserved */
-	__u32 manu[5];		/* manufacturer specific information */
-} capi_profile;
-
-#define CAPI_GET_PROFILE	_IOWR('C',0x09,struct capi_profile)
-
-typedef struct capi_manufacturer_cmd {
-	unsigned long cmd;
-	void __user *data;
-} capi_manufacturer_cmd;
-
-/*
- * CAPI_MANUFACTURER_CMD
- */
-
-#define CAPI_MANUFACTURER_CMD	_IOWR('C',0x20, struct capi_manufacturer_cmd)
-
-/*
- * CAPI_GET_ERRCODE
- * capi errcode is set, * if read, write, or ioctl returns EIO,
- * ioctl returns errcode directly, and in arg, if != 0
- */
-
-#define CAPI_GET_ERRCODE	_IOR('C',0x21, __u16)
-
-/*
- * CAPI_INSTALLED
- */
-#define CAPI_INSTALLED		_IOR('C',0x22, __u16)
-
-
-/*
- * member contr is input for
- * CAPI_GET_MANUFACTURER, CAPI_GET_VERSION, CAPI_GET_SERIAL
- * and CAPI_GET_PROFILE
- */
-typedef union capi_ioctl_struct {
-	__u32 contr;
-	capi_register_params rparams;
-	__u8 manufacturer[CAPI_MANUFACTURER_LEN];
-	capi_version version;
-	__u8 serial[CAPI_SERIAL_LEN];
-	capi_profile profile;
-	capi_manufacturer_cmd cmd;
-	__u16 errcode;
-} capi_ioctl_struct;
-
-/*
- * Middleware extension
- */
-
-#define CAPIFLAG_HIGHJACKING	0x0001
-
-#define CAPI_GET_FLAGS		_IOR('C',0x23, unsigned)
-#define CAPI_SET_FLAGS		_IOR('C',0x24, unsigned)
-#define CAPI_CLR_FLAGS		_IOR('C',0x25, unsigned)
-
-#define CAPI_NCCI_OPENCOUNT	_IOR('C',0x26, unsigned)
-
-#define CAPI_NCCI_GETUNIT	_IOR('C',0x27, unsigned)
-
-#endif				/* __LINUX_CAPI_H__ */