File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/net/slip/slip.h b/drivers/net/slip/slip.h
new file mode 100644
index 0000000..cf32aad
--- /dev/null
+++ b/drivers/net/slip/slip.h
@@ -0,0 +1,102 @@
+/*
+ * slip.h	Define the SLIP device driver interface and constants.
+ *
+ * NOTE:	THIS FILE WILL BE MOVED TO THE LINUX INCLUDE DIRECTORY
+ *		AS SOON AS POSSIBLE!
+ *
+ * Version:	@(#)slip.h	1.2.0	03/28/93
+ *
+ * Fixes:
+ *		Alan Cox	: 	Added slip mtu field.
+ *		Matt Dillon	:	Printable slip (borrowed from net2e)
+ *		Alan Cox	:	Added SL_SLIP_LOTS
+ *	Dmitry Gorodchanin	:	A lot of changes in the 'struct slip'
+ *	Dmitry Gorodchanin	:	Added CSLIP statistics.
+ *	Stanislav Voronyi	:	Make line checking as created by
+ *					Igor Chechik, RELCOM Corp.
+ *	Craig Schlenter		:	Fixed #define bug that caused
+ *					CSLIP telnets to hang in 1.3.61-6
+ *
+ * Author:	Fred N. van Kempen, <waltje@uwalt.nl.mugnet.org>
+ */
+#ifndef _LINUX_SLIP_H
+#define _LINUX_SLIP_H
+
+
+#if defined(CONFIG_INET) && defined(CONFIG_SLIP_COMPRESSED)
+# define SL_INCLUDE_CSLIP
+#endif
+
+#ifdef SL_INCLUDE_CSLIP
+# define SL_MODE_DEFAULT SL_MODE_ADAPTIVE
+#else
+# define SL_MODE_DEFAULT SL_MODE_SLIP
+#endif
+
+/* SLIP configuration. */
+#define SL_NRUNIT	256		/* MAX number of SLIP channels;
+					   This can be overridden with
+					   insmod -oslip_maxdev=nnn	*/
+#define SL_MTU		296		/* 296; I am used to 600- FvK	*/
+
+/* SLIP protocol characters. */
+#define END             0300		/* indicates end of frame	*/
+#define ESC             0333		/* indicates byte stuffing	*/
+#define ESC_END         0334		/* ESC ESC_END means END 'data'	*/
+#define ESC_ESC         0335		/* ESC ESC_ESC means ESC 'data'	*/
+
+
+struct slip {
+  int			magic;
+
+  /* Various fields. */
+  struct tty_struct	*tty;		/* ptr to TTY structure		*/
+  struct net_device	*dev;		/* easy for intr handling	*/
+  spinlock_t		lock;
+  struct work_struct	tx_work;	/* Flushes transmit buffer	*/
+
+#ifdef SL_INCLUDE_CSLIP
+  struct slcompress	*slcomp;	/* for header compression 	*/
+  unsigned char		*cbuff;		/* compression buffer		*/
+#endif
+
+  /* These are pointers to the malloc()ed frame buffers. */
+  unsigned char		*rbuff;		/* receiver buffer		*/
+  int                   rcount;         /* received chars counter       */
+  unsigned char		*xbuff;		/* transmitter buffer		*/
+  unsigned char         *xhead;         /* pointer to next byte to XMIT */
+  int                   xleft;          /* bytes left in XMIT queue     */
+  int			mtu;		/* Our mtu (to spot changes!)   */
+  int                   buffsize;       /* Max buffers sizes            */
+
+#ifdef CONFIG_SLIP_MODE_SLIP6
+  int			xdata, xbits;	/* 6 bit slip controls 		*/
+#endif
+
+  unsigned long		flags;		/* Flag values/ mode etc	*/
+#define SLF_INUSE	0		/* Channel in use               */
+#define SLF_ESCAPE	1               /* ESC received                 */
+#define SLF_ERROR	2               /* Parity, etc. error           */
+#define SLF_KEEPTEST	3		/* Keepalive test flag		*/
+#define SLF_OUTWAIT	4		/* is outpacket was flag	*/
+
+  unsigned char		mode;		/* SLIP mode			*/
+  unsigned char		leased;
+  pid_t			pid;
+#define SL_MODE_SLIP	0
+#define SL_MODE_CSLIP	1
+#define SL_MODE_SLIP6	2		/* Matt Dillon's printable slip */
+#define SL_MODE_CSLIP6	(SL_MODE_SLIP6|SL_MODE_CSLIP)
+#define SL_MODE_AX25	4
+#define SL_MODE_ADAPTIVE 8
+#ifdef CONFIG_SLIP_SMART
+  unsigned char		outfill;	/* # of sec between outfill packet */
+  unsigned char		keepalive;	/* keepalive seconds		*/
+  struct timer_list	outfill_timer;
+  struct timer_list	keepalive_timer;
+#endif
+};
+
+#define SLIP_MAGIC 0x5302
+
+#endif	/* _LINUX_SLIP.H */