Revert "remove the strip driver"
David S. Miller [Fri, 18 Jul 2008 10:58:52 +0000 (03:58 -0700)]
This reverts commit 94d9842403f770239a656586442454b7a8f2df29.

Alan says it's not appropriate to remove this driver,
Adrian Bunk also agrees with this revert.

Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS
drivers/net/wireless/Kconfig
drivers/net/wireless/Makefile
drivers/net/wireless/strip.c [new file with mode: 0644]

index f92707f..ec0c9c9 100644 (file)
@@ -3908,6 +3908,10 @@ P:       Ion Badulescu
 M:     ionut@cs.columbia.edu
 S:     Maintained
 
+STARMODE RADIO IP (STRIP) PROTOCOL DRIVER
+W:     http://mosquitonet.Stanford.EDU/strip.html
+S:     Unsupported ?
+
 STRADIS MPEG-2 DECODER DRIVER
 P:     Nathan Laredo
 M:     laredo@gnu.org
index d5b006f..91fc2c7 100644 (file)
@@ -14,6 +14,30 @@ config WLAN_PRE80211
          This option does not affect the kernel build, it only
          lets you choose drivers.
 
+config STRIP
+       tristate "STRIP (Metricom starmode radio IP)"
+       depends on INET && WLAN_PRE80211
+       select WIRELESS_EXT
+       ---help---
+         Say Y if you have a Metricom radio and intend to use Starmode Radio
+         IP. STRIP is a radio protocol developed for the MosquitoNet project
+         (on the WWW at <http://mosquitonet.stanford.edu/>) to send Internet
+         traffic using Metricom radios.  Metricom radios are small, battery
+         powered, 100kbit/sec packet radio transceivers, about the size and
+         weight of a cellular telephone. (You may also have heard them called
+         "Metricom modems" but we avoid the term "modem" because it misleads
+         many people into thinking that you can plug a Metricom modem into a
+         phone line and use it as a modem.)
+
+         You can use STRIP on any Linux machine with a serial port, although
+         it is obviously most useful for people with laptop computers. If you
+         think you might get a Metricom radio in the future, there is no harm
+         in saying Y to STRIP now, except that it makes the kernel a bit
+         bigger.
+
+         To compile this as a module, choose M here: the module will be
+         called strip.
+
 config ARLAN
        tristate "Aironet Arlan 655 & IC2200 DS support"
        depends on ISA && !64BIT && WLAN_PRE80211
index 2668934..54a4f6f 100644 (file)
@@ -6,6 +6,7 @@ obj-$(CONFIG_IPW2100) += ipw2100.o
 
 obj-$(CONFIG_IPW2200) += ipw2200.o
 
+obj-$(CONFIG_STRIP) += strip.o
 obj-$(CONFIG_ARLAN) += arlan.o 
 
 arlan-objs := arlan-main.o arlan-proc.o
diff --git a/drivers/net/wireless/strip.c b/drivers/net/wireless/strip.c
new file mode 100644 (file)
index 0000000..883af89
--- /dev/null
@@ -0,0 +1,2804 @@
+/*
+ * Copyright 1996 The Board of Trustees of The Leland Stanford
+ * Junior University. All Rights Reserved.
+ *
+ * Permission to use, copy, modify, and distribute this
+ * software and its documentation for any purpose and without
+ * fee is hereby granted, provided that the above copyright
+ * notice appear in all copies.  Stanford University
+ * makes no representations about the suitability of this
+ * software for any purpose.  It is provided "as is" without
+ * express or implied warranty.
+ *
+ * strip.c     This module implements Starmode Radio IP (STRIP)
+ *             for kernel-based devices like TTY.  It interfaces between a
+ *             raw TTY, and the kernel's INET protocol layers (via DDI).
+ *
+ * Version:    @(#)strip.c     1.3     July 1997
+ *
+ * Author:     Stuart Cheshire <cheshire@cs.stanford.edu>
+ *
+ * Fixes:      v0.9 12th Feb 1996 (SC)
+ *             New byte stuffing (2+6 run-length encoding)
+ *             New watchdog timer task
+ *             New Protocol key (SIP0)
+ *             
+ *             v0.9.1 3rd March 1996 (SC)
+ *             Changed to dynamic device allocation -- no more compile
+ *             time (or boot time) limit on the number of STRIP devices.
+ *             
+ *             v0.9.2 13th March 1996 (SC)
+ *             Uses arp cache lookups (but doesn't send arp packets yet)
+ *             
+ *             v0.9.3 17th April 1996 (SC)
+ *             Fixed bug where STR_ERROR flag was getting set unneccessarily
+ *             (causing otherwise good packets to be unneccessarily dropped)
+ *             
+ *             v0.9.4 27th April 1996 (SC)
+ *             First attempt at using "&COMMAND" Starmode AT commands
+ *             
+ *             v0.9.5 29th May 1996 (SC)
+ *             First attempt at sending (unicast) ARP packets
+ *             
+ *             v0.9.6 5th June 1996 (Elliot)
+ *             Put "message level" tags in every "printk" statement
+ *             
+ *             v0.9.7 13th June 1996 (laik)
+ *             Added support for the /proc fs
+ *
+ *              v0.9.8 July 1996 (Mema)
+ *              Added packet logging
+ *
+ *              v1.0 November 1996 (SC)
+ *              Fixed (severe) memory leaks in the /proc fs code
+ *              Fixed race conditions in the logging code
+ *
+ *              v1.1 January 1997 (SC)
+ *              Deleted packet logging (use tcpdump instead)
+ *              Added support for Metricom Firmware v204 features
+ *              (like message checksums)
+ *
+ *              v1.2 January 1997 (SC)
+ *              Put portables list back in
+ *
+ *              v1.3 July 1997 (SC)
+ *              Made STRIP driver set the radio's baud rate automatically.
+ *              It is no longer necessarily to manually set the radio's
+ *              rate permanently to 115200 -- the driver handles setting
+ *              the rate automatically.
+ */
+
+#ifdef MODULE
+static const char StripVersion[] = "1.3A-STUART.CHESHIRE-MODULAR";
+#else
+static const char StripVersion[] = "1.3A-STUART.CHESHIRE";
+#endif
+
+#define TICKLE_TIMERS 0
+#define EXT_COUNTERS 1
+
+
+/************************************************************************/
+/* Header files                                                                */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+# include <linux/ctype.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/in.h>
+#include <linux/tty.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/inetdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/if_arp.h>
+#include <linux/if_strip.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/serial.h>
+#include <linux/serialP.h>
+#include <linux/rcupdate.h>
+#include <net/arp.h>
+#include <net/net_namespace.h>
+
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/time.h>
+#include <linux/jiffies.h>
+
+/************************************************************************/
+/* Useful structures and definitions                                   */
+
+/*
+ * A MetricomKey identifies the protocol being carried inside a Metricom
+ * Starmode packet.
+ */
+
+typedef union {
+       __u8 c[4];
+       __u32 l;
+} MetricomKey;
+
+/*
+ * An IP address can be viewed as four bytes in memory (which is what it is) or as
+ * a single 32-bit long (which is convenient for assignment, equality testing etc.)
+ */
+
+typedef union {
+       __u8 b[4];
+       __u32 l;
+} IPaddr;
+
+/*
+ * A MetricomAddressString is used to hold a printable representation of
+ * a Metricom address.
+ */
+
+typedef struct {
+       __u8 c[24];
+} MetricomAddressString;
+
+/* Encapsulation can expand packet of size x to 65/64x + 1
+ * Sent packet looks like "<CR>*<address>*<key><encaps payload><CR>"
+ *                           1 1   1-18  1  4         ?         1
+ * eg.                     <CR>*0000-1234*SIP0<encaps payload><CR>
+ * We allow 31 bytes for the stars, the key, the address and the <CR>s
+ */
+#define STRIP_ENCAP_SIZE(X) (32 + (X)*65L/64L)
+
+/*
+ * A STRIP_Header is never really sent over the radio, but making a dummy
+ * header for internal use within the kernel that looks like an Ethernet
+ * header makes certain other software happier. For example, tcpdump
+ * already understands Ethernet headers.
+ */
+
+typedef struct {
+       MetricomAddress dst_addr;       /* Destination address, e.g. "0000-1234"   */
+       MetricomAddress src_addr;       /* Source address, e.g. "0000-5678"        */
+       unsigned short protocol;        /* The protocol type, using Ethernet codes */
+} STRIP_Header;
+
+typedef struct {
+       char c[60];
+} MetricomNode;
+
+#define NODE_TABLE_SIZE 32
+typedef struct {
+       struct timeval timestamp;
+       int num_nodes;
+       MetricomNode node[NODE_TABLE_SIZE];
+} MetricomNodeTable;
+
+enum { FALSE = 0, TRUE = 1 };
+
+/*
+ * Holds the radio's firmware version.
+ */
+typedef struct {
+       char c[50];
+} FirmwareVersion;
+
+/*
+ * Holds the radio's serial number.
+ */
+typedef struct {
+       char c[18];
+} SerialNumber;
+
+/*
+ * Holds the radio's battery voltage.
+ */
+typedef struct {
+       char c[11];
+} BatteryVoltage;
+
+typedef struct {
+       char c[8];
+} char8;
+
+enum {
+       NoStructure = 0,        /* Really old firmware */
+       StructuredMessages = 1, /* Parsable AT response msgs */
+       ChecksummedMessages = 2 /* Parsable AT response msgs with checksums */
+};
+
+struct strip {
+       int magic;
+       /*
+        * These are pointers to the malloc()ed frame buffers.
+        */
+
+       unsigned char *rx_buff; /* buffer for received IP packet */
+       unsigned char *sx_buff; /* buffer for received serial data */
+       int sx_count;           /* received serial data counter */
+       int sx_size;            /* Serial buffer size           */
+       unsigned char *tx_buff; /* transmitter buffer           */
+       unsigned char *tx_head; /* pointer to next byte to XMIT */
+       int tx_left;            /* bytes left in XMIT queue     */
+       int tx_size;            /* Serial buffer size           */
+
+       /*
+        * STRIP interface statistics.
+        */
+
+       unsigned long rx_packets;       /* inbound frames counter       */
+       unsigned long tx_packets;       /* outbound frames counter      */
+       unsigned long rx_errors;        /* Parity, etc. errors          */
+       unsigned long tx_errors;        /* Planned stuff                */
+       unsigned long rx_dropped;       /* No memory for skb            */
+       unsigned long tx_dropped;       /* When MTU change              */
+       unsigned long rx_over_errors;   /* Frame bigger then STRIP buf. */
+
+       unsigned long pps_timer;        /* Timer to determine pps       */
+       unsigned long rx_pps_count;     /* Counter to determine pps     */
+       unsigned long tx_pps_count;     /* Counter to determine pps     */
+       unsigned long sx_pps_count;     /* Counter to determine pps     */
+       unsigned long rx_average_pps;   /* rx packets per second * 8    */
+       unsigned long tx_average_pps;   /* tx packets per second * 8    */
+       unsigned long sx_average_pps;   /* sent packets per second * 8  */
+
+#ifdef EXT_COUNTERS
+       unsigned long rx_bytes;         /* total received bytes */
+       unsigned long tx_bytes;         /* total received bytes */
+       unsigned long rx_rbytes;        /* bytes thru radio i/f */
+       unsigned long tx_rbytes;        /* bytes thru radio i/f */
+       unsigned long rx_sbytes;        /* tot bytes thru serial i/f */
+       unsigned long tx_sbytes;        /* tot bytes thru serial i/f */
+       unsigned long rx_ebytes;        /* tot stat/err bytes */
+       unsigned long tx_ebytes;        /* tot stat/err bytes */
+#endif
+
+       /*
+        * Internal variables.
+        */
+
+       struct list_head  list;         /* Linked list of devices */
+
+       int discard;                    /* Set if serial error          */
+       int working;                    /* Is radio working correctly?  */
+       int firmware_level;             /* Message structuring level    */
+       int next_command;               /* Next periodic command        */
+       unsigned int user_baud;         /* The user-selected baud rate  */
+       int mtu;                        /* Our mtu (to spot changes!)   */
+       long watchdog_doprobe;          /* Next time to test the radio  */
+       long watchdog_doreset;          /* Time to do next reset        */
+       long gratuitous_arp;            /* Time to send next ARP refresh */
+       long arp_interval;              /* Next ARP interval            */
+       struct timer_list idle_timer;   /* For periodic wakeup calls    */
+       MetricomAddress true_dev_addr;  /* True address of radio        */
+       int manual_dev_addr;            /* Hack: See note below         */
+
+       FirmwareVersion firmware_version;       /* The radio's firmware version */
+       SerialNumber serial_number;     /* The radio's serial number    */
+       BatteryVoltage battery_voltage; /* The radio's battery voltage  */
+
+       /*
+        * Other useful structures.
+        */
+
+       struct tty_struct *tty;         /* ptr to TTY structure         */
+       struct net_device *dev;         /* Our device structure         */
+
+       /*
+        * Neighbour radio records
+        */
+
+       MetricomNodeTable portables;
+       MetricomNodeTable poletops;
+};
+
+/*
+ * Note: manual_dev_addr hack
+ * 
+ * It is not possible to change the hardware address of a Metricom radio,
+ * or to send packets with a user-specified hardware source address, thus
+ * trying to manually set a hardware source address is a questionable
+ * thing to do.  However, if the user *does* manually set the hardware
+ * source address of a STRIP interface, then the kernel will believe it,
+ * and use it in certain places. For example, the hardware address listed
+ * by ifconfig will be the manual address, not the true one.
+ * (Both addresses are listed in /proc/net/strip.)
+ * Also, ARP packets will be sent out giving the user-specified address as
+ * the source address, not the real address. This is dangerous, because
+ * it means you won't receive any replies -- the ARP replies will go to
+ * the specified address, which will be some other radio. The case where
+ * this is useful is when that other radio is also connected to the same
+ * machine. This allows you to connect a pair of radios to one machine,
+ * and to use one exclusively for inbound traffic, and the other
+ * exclusively for outbound traffic. Pretty neat, huh?
+ * 
+ * Here's the full procedure to set this up:
+ * 
+ * 1. "slattach" two interfaces, e.g. st0 for outgoing packets,
+ *    and st1 for incoming packets
+ * 
+ * 2. "ifconfig" st0 (outbound radio) to have the hardware address
+ *    which is the real hardware address of st1 (inbound radio).
+ *    Now when it sends out packets, it will masquerade as st1, and
+ *    replies will be sent to that radio, which is exactly what we want.
+ * 
+ * 3. Set the route table entry ("route add default ..." or
+ *    "route add -net ...", as appropriate) to send packets via the st0
+ *    interface (outbound radio). Do not add any route which sends packets
+ *    out via the st1 interface -- that radio is for inbound traffic only.
+ * 
+ * 4. "ifconfig" st1 (inbound radio) to have hardware address zero.
+ *    This tells the STRIP driver to "shut down" that interface and not
+ *    send any packets through it. In particular, it stops sending the
+ *    periodic gratuitous ARP packets that a STRIP interface normally sends.
+ *    Also, when packets arrive on that interface, it will search the
+ *    interface list to see if there is another interface who's manual
+ *    hardware address matches its own real address (i.e. st0 in this
+ *    example) and if so it will transfer ownership of the skbuff to
+ *    that interface, so that it looks to the kernel as if the packet
+ *    arrived on that interface. This is necessary because when the
+ *    kernel sends an ARP packet on st0, it expects to get a reply on
+ *    st0, and if it sees the reply come from st1 then it will ignore
+ *    it (to be accurate, it puts the entry in the ARP table, but
+ *    labelled in such a way that st0 can't use it).
+ * 
+ * Thanks to Petros Maniatis for coming up with the idea of splitting
+ * inbound and outbound traffic between two interfaces, which turned
+ * out to be really easy to implement, even if it is a bit of a hack.
+ * 
+ * Having set a manual address on an interface, you can restore it
+ * to automatic operation (where the address is automatically kept
+ * consistent with the real address of the radio) by setting a manual
+ * address of all ones, e.g. "ifconfig st0 hw strip FFFFFFFFFFFF"
+ * This 'turns off' manual override mode for the device address.
+ * 
+ * Note: The IEEE 802 headers reported in tcpdump will show the *real*
+ * radio addresses the packets were sent and received from, so that you
+ * can see what is really going on with packets, and which interfaces
+ * they are really going through.
+ */
+
+
+/************************************************************************/
+/* Constants                                                           */
+
+/*
+ * CommandString1 works on all radios
+ * Other CommandStrings are only used with firmware that provides structured responses.
+ * 
+ * ats319=1 Enables Info message for node additions and deletions
+ * ats319=2 Enables Info message for a new best node
+ * ats319=4 Enables checksums
+ * ats319=8 Enables ACK messages
+ */
+
+static const int MaxCommandStringLength = 32;
+static const int CompatibilityCommand = 1;
+
+static const char CommandString0[] = "*&COMMAND*ATS319=7";     /* Turn on checksums & info messages */
+static const char CommandString1[] = "*&COMMAND*ATS305?";      /* Query radio name */
+static const char CommandString2[] = "*&COMMAND*ATS325?";      /* Query battery voltage */
+static const char CommandString3[] = "*&COMMAND*ATS300?";      /* Query version information */
+static const char CommandString4[] = "*&COMMAND*ATS311?";      /* Query poletop list */
+static const char CommandString5[] = "*&COMMAND*AT~LA";                /* Query portables list */
+typedef struct {
+       const char *string;
+       long length;
+} StringDescriptor;
+
+static const StringDescriptor CommandString[] = {
+       {CommandString0, sizeof(CommandString0) - 1},
+       {CommandString1, sizeof(CommandString1) - 1},
+       {CommandString2, sizeof(CommandString2) - 1},
+       {CommandString3, sizeof(CommandString3) - 1},
+       {CommandString4, sizeof(CommandString4) - 1},
+       {CommandString5, sizeof(CommandString5) - 1}
+};
+
+#define GOT_ALL_RADIO_INFO(S)      \
+    ((S)->firmware_version.c[0] && \
+     (S)->battery_voltage.c[0]  && \
+     memcmp(&(S)->true_dev_addr, zero_address.c, sizeof(zero_address)))
+
+static const char hextable[16] = "0123456789ABCDEF";
+
+static const MetricomAddress zero_address;
+static const MetricomAddress broadcast_address =
+    { {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF} };
+
+static const MetricomKey SIP0Key = { "SIP0" };
+static const MetricomKey ARP0Key = { "ARP0" };
+static const MetricomKey ATR_Key = { "ATR " };
+static const MetricomKey ACK_Key = { "ACK_" };
+static const MetricomKey INF_Key = { "INF_" };
+static const MetricomKey ERR_Key = { "ERR_" };
+
+static const long MaxARPInterval = 60 * HZ;    /* One minute */
+
+/*
+ * Maximum Starmode packet length is 1183 bytes. Allowing 4 bytes for
+ * protocol key, 4 bytes for checksum, one byte for CR, and 65/64 expansion
+ * for STRIP encoding, that translates to a maximum payload MTU of 1155.
+ * Note: A standard NFS 1K data packet is a total of 0x480 (1152) bytes
+ * long, including IP header, UDP header, and NFS header. Setting the STRIP
+ * MTU to 1152 allows us to send default sized NFS packets without fragmentation.
+ */
+static const unsigned short MAX_SEND_MTU = 1152;
+static const unsigned short MAX_RECV_MTU = 1500;       /* Hoping for Ethernet sized packets in the future! */
+static const unsigned short DEFAULT_STRIP_MTU = 1152;
+static const int STRIP_MAGIC = 0x5303;
+static const long LongTime = 0x7FFFFFFF;
+
+/************************************************************************/
+/* Global variables                                                    */
+
+static LIST_HEAD(strip_list);
+static DEFINE_SPINLOCK(strip_lock);
+
+/************************************************************************/
+/* Macros                                                              */
+
+/* Returns TRUE if text T begins with prefix P */
+#define has_prefix(T,L,P) (((L) >= sizeof(P)-1) && !strncmp((T), (P), sizeof(P)-1))
+
+/* Returns TRUE if text T of length L is equal to string S */
+#define text_equal(T,L,S) (((L) == sizeof(S)-1) && !strncmp((T), (S), sizeof(S)-1))
+
+#define READHEX(X) ((X)>='0' && (X)<='9' ? (X)-'0' :      \
+                    (X)>='a' && (X)<='f' ? (X)-'a'+10 :   \
+                    (X)>='A' && (X)<='F' ? (X)-'A'+10 : 0 )
+
+#define READHEX16(X) ((__u16)(READHEX(X)))
+
+#define READDEC(X) ((X)>='0' && (X)<='9' ? (X)-'0' : 0)
+
+#define ARRAY_END(X) (&((X)[ARRAY_SIZE(X)]))
+
+#define JIFFIE_TO_SEC(X) ((X) / HZ)
+
+
+/************************************************************************/
+/* Utility routines                                                    */
+
+static int arp_query(unsigned char *haddr, u32 paddr,
+                    struct net_device *dev)
+{
+       struct neighbour *neighbor_entry;
+       int ret = 0;
+
+       neighbor_entry = neigh_lookup(&arp_tbl, &paddr, dev);
+
+       if (neighbor_entry != NULL) {
+               neighbor_entry->used = jiffies;
+               if (neighbor_entry->nud_state & NUD_VALID) {
+                       memcpy(haddr, neighbor_entry->ha, dev->addr_len);
+                       ret = 1;
+               }
+               neigh_release(neighbor_entry);
+       }
+       return ret;
+}
+
+static void DumpData(char *msg, struct strip *strip_info, __u8 * ptr,
+                    __u8 * end)
+{
+       static const int MAX_DumpData = 80;
+       __u8 pkt_text[MAX_DumpData], *p = pkt_text;
+
+       *p++ = '\"';
+
+       while (ptr < end && p < &pkt_text[MAX_DumpData - 4]) {
+               if (*ptr == '\\') {
+                       *p++ = '\\';
+                       *p++ = '\\';
+               } else {
+                       if (*ptr >= 32 && *ptr <= 126) {
+                               *p++ = *ptr;
+                       } else {
+                               sprintf(p, "\\%02X", *ptr);
+                               p += 3;
+                       }
+               }
+               ptr++;
+       }
+
+       if (ptr == end)
+               *p++ = '\"';
+       *p++ = 0;
+
+       printk(KERN_INFO "%s: %-13s%s\n", strip_info->dev->name, msg, pkt_text);
+}
+
+
+/************************************************************************/
+/* Byte stuffing/unstuffing routines                                   */
+
+/* Stuffing scheme:
+ * 00    Unused (reserved character)
+ * 01-3F Run of 2-64 different characters
+ * 40-7F Run of 1-64 different characters plus a single zero at the end
+ * 80-BF Run of 1-64 of the same character
+ * C0-FF Run of 1-64 zeroes (ASCII 0)
+ */
+
+typedef enum {
+       Stuff_Diff = 0x00,
+       Stuff_DiffZero = 0x40,
+       Stuff_Same = 0x80,
+       Stuff_Zero = 0xC0,
+       Stuff_NoCode = 0xFF,    /* Special code, meaning no code selected */
+
+       Stuff_CodeMask = 0xC0,
+       Stuff_CountMask = 0x3F,
+       Stuff_MaxCount = 0x3F,
+       Stuff_Magic = 0x0D      /* The value we are eliminating */
+} StuffingCode;
+
+/* StuffData encodes the data starting at "src" for "length" bytes.
+ * It writes it to the buffer pointed to by "dst" (which must be at least
+ * as long as 1 + 65/64 of the input length). The output may be up to 1.6%
+ * larger than the input for pathological input, but will usually be smaller.
+ * StuffData returns the new value of the dst pointer as its result.
+ * "code_ptr_ptr" points to a "__u8 *" which is used to hold encoding state
+ * between calls, allowing an encoded packet to be incrementally built up
+ * from small parts. On the first call, the "__u8 *" pointed to should be
+ * initialized to NULL; between subsequent calls the calling routine should
+ * leave the value alone and simply pass it back unchanged so that the
+ * encoder can recover its current state.
+ */
+
+#define StuffData_FinishBlock(X) \
+(*code_ptr = (X) ^ Stuff_Magic, code = Stuff_NoCode)
+
+static __u8 *StuffData(__u8 * src, __u32 length, __u8 * dst,
+                      __u8 ** code_ptr_ptr)
+{
+       __u8 *end = src + length;
+       __u8 *code_ptr = *code_ptr_ptr;
+       __u8 code = Stuff_NoCode, count = 0;
+
+       if (!length)
+               return (dst);
+
+       if (code_ptr) {
+               /*
+                * Recover state from last call, if applicable
+                */
+               code = (*code_ptr ^ Stuff_Magic) & Stuff_CodeMask;
+               count = (*code_ptr ^ Stuff_Magic) & Stuff_CountMask;
+       }
+
+       while (src < end) {
+               switch (code) {
+                       /* Stuff_NoCode: If no current code, select one */
+               case Stuff_NoCode:
+                       /* Record where we're going to put this code */
+                       code_ptr = dst++;
+                       count = 0;      /* Reset the count (zero means one instance) */
+                       /* Tentatively start a new block */
+                       if (*src == 0) {
+                               code = Stuff_Zero;
+                               src++;
+                       } else {
+                               code = Stuff_Same;
+                               *dst++ = *src++ ^ Stuff_Magic;
+                       }
+                       /* Note: We optimistically assume run of same -- */
+                       /* which will be fixed later in Stuff_Same */
+                       /* if it turns out not to be true. */
+                       break;
+
+                       /* Stuff_Zero: We already have at least one zero encoded */
+               case Stuff_Zero:
+                       /* If another zero, count it, else finish this code block */
+                       if (*src == 0) {
+                               count++;
+                               src++;
+                       } else {
+                               StuffData_FinishBlock(Stuff_Zero + count);
+                       }
+                       break;
+
+                       /* Stuff_Same: We already have at least one byte encoded */
+               case Stuff_Same:
+                       /* If another one the same, count it */
+                       if ((*src ^ Stuff_Magic) == code_ptr[1]) {
+                               count++;
+                               src++;
+                               break;
+                       }
+                       /* else, this byte does not match this block. */
+                       /* If we already have two or more bytes encoded, finish this code block */
+                       if (count) {
+                               StuffData_FinishBlock(Stuff_Same + count);
+                               break;
+                       }
+                       /* else, we only have one so far, so switch to Stuff_Diff code */
+                       code = Stuff_Diff;
+                       /* and fall through to Stuff_Diff case below
+                        * Note cunning cleverness here: case Stuff_Diff compares 
+                        * the current character with the previous two to see if it
+                        * has a run of three the same. Won't this be an error if
+                        * there aren't two previous characters stored to compare with?
+                        * No. Because we know the current character is *not* the same
+                        * as the previous one, the first test below will necessarily
+                        * fail and the send half of the "if" won't be executed.
+                        */
+
+                       /* Stuff_Diff: We have at least two *different* bytes encoded */
+               case Stuff_Diff:
+                       /* If this is a zero, must encode a Stuff_DiffZero, and begin a new block */
+                       if (*src == 0) {
+                               StuffData_FinishBlock(Stuff_DiffZero +
+                                                     count);
+                       }
+                       /* else, if we have three in a row, it is worth starting a Stuff_Same block */
+                       else if ((*src ^ Stuff_Magic) == dst[-1]
+                                && dst[-1] == dst[-2]) {
+                               /* Back off the last two characters we encoded */
+                               code += count - 2;
+                               /* Note: "Stuff_Diff + 0" is an illegal code */
+                               if (code == Stuff_Diff + 0) {
+                                       code = Stuff_Same + 0;
+                               }
+                               StuffData_FinishBlock(code);
+                               code_ptr = dst - 2;
+                               /* dst[-1] already holds the correct value */
+                               count = 2;      /* 2 means three bytes encoded */
+                               code = Stuff_Same;
+                       }
+                       /* else, another different byte, so add it to the block */
+                       else {
+                               *dst++ = *src ^ Stuff_Magic;
+                               count++;
+                       }
+                       src++;  /* Consume the byte */
+                       break;
+               }
+               if (count == Stuff_MaxCount) {
+                       StuffData_FinishBlock(code + count);
+               }
+       }
+       if (code == Stuff_NoCode) {
+               *code_ptr_ptr = NULL;
+       } else {
+               *code_ptr_ptr = code_ptr;
+               StuffData_FinishBlock(code + count);
+       }
+       return (dst);
+}
+
+/*
+ * UnStuffData decodes the data at "src", up to (but not including) "end".
+ * It writes the decoded data into the buffer pointed to by "dst", up to a
+ * maximum of "dst_length", and returns the new value of "src" so that a
+ * follow-on call can read more data, continuing from where the first left off.
+ * 
+ * There are three types of results:
+ * 1. The source data runs out before extracting "dst_length" bytes:
+ *    UnStuffData returns NULL to indicate failure.
+ * 2. The source data produces exactly "dst_length" bytes:
+ *    UnStuffData returns new_src = end to indicate that all bytes were consumed.
+ * 3. "dst_length" bytes are extracted, with more remaining.
+ *    UnStuffData returns new_src < end to indicate that there are more bytes
+ *    to be read.
+ * 
+ * Note: The decoding may be destructive, in that it may alter the source
+ * data in the process of decoding it (this is necessary to allow a follow-on
+ * call to resume correctly).
+ */
+
+static __u8 *UnStuffData(__u8 * src, __u8 * end, __u8 * dst,
+                        __u32 dst_length)
+{
+       __u8 *dst_end = dst + dst_length;
+       /* Sanity check */
+       if (!src || !end || !dst || !dst_length)
+               return (NULL);
+       while (src < end && dst < dst_end) {
+               int count = (*src ^ Stuff_Magic) & Stuff_CountMask;
+               switch ((*src ^ Stuff_Magic) & Stuff_CodeMask) {
+               case Stuff_Diff:
+                       if (src + 1 + count >= end)
+                               return (NULL);
+                       do {
+                               *dst++ = *++src ^ Stuff_Magic;
+                       }
+                       while (--count >= 0 && dst < dst_end);
+                       if (count < 0)
+                               src += 1;
+                       else {
+                               if (count == 0)
+                                       *src = Stuff_Same ^ Stuff_Magic;
+                               else
+                                       *src =
+                                           (Stuff_Diff +
+                                            count) ^ Stuff_Magic;
+                       }
+                       break;
+               case Stuff_DiffZero:
+                       if (src + 1 + count >= end)
+                               return (NULL);
+                       do {
+                               *dst++ = *++src ^ Stuff_Magic;
+                       }
+                       while (--count >= 0 && dst < dst_end);
+                       if (count < 0)
+                               *src = Stuff_Zero ^ Stuff_Magic;
+                       else
+                               *src =
+                                   (Stuff_DiffZero + count) ^ Stuff_Magic;
+                       break;
+               case Stuff_Same:
+                       if (src + 1 >= end)
+                               return (NULL);
+                       do {
+                               *dst++ = src[1] ^ Stuff_Magic;
+                       }
+                       while (--count >= 0 && dst < dst_end);
+                       if (count < 0)
+                               src += 2;
+                       else
+                               *src = (Stuff_Same + count) ^ Stuff_Magic;
+                       break;
+               case Stuff_Zero:
+                       do {
+                               *dst++ = 0;
+                       }
+                       while (--count >= 0 && dst < dst_end);
+                       if (count < 0)
+                               src += 1;
+                       else
+                               *src = (Stuff_Zero + count) ^ Stuff_Magic;
+                       break;
+               }
+       }
+       if (dst < dst_end)
+               return (NULL);
+       else
+               return (src);
+}
+
+
+/************************************************************************/
+/* General routines for STRIP                                          */
+
+/*
+ * set_baud sets the baud rate to the rate defined by baudcode
+ */
+static void set_baud(struct tty_struct *tty, speed_t baudrate)
+{
+       struct ktermios old_termios;
+
+       mutex_lock(&tty->termios_mutex);
+       old_termios =*(tty->termios);
+       tty_encode_baud_rate(tty, baudrate, baudrate);
+       tty->ops->set_termios(tty, &old_termios);
+       mutex_unlock(&tty->termios_mutex);
+}
+
+/*
+ * Convert a string to a Metricom Address.
+ */
+
+#define IS_RADIO_ADDRESS(p) (                                                 \
+  isdigit((p)[0]) && isdigit((p)[1]) && isdigit((p)[2]) && isdigit((p)[3]) && \
+  (p)[4] == '-' &&                                                            \
+  isdigit((p)[5]) && isdigit((p)[6]) && isdigit((p)[7]) && isdigit((p)[8])    )
+
+static int string_to_radio_address(MetricomAddress * addr, __u8 * p)
+{
+       if (!IS_RADIO_ADDRESS(p))
+               return (1);
+       addr->c[0] = 0;
+       addr->c[1] = 0;
+       addr->c[2] = READHEX(p[0]) << 4 | READHEX(p[1]);
+       addr->c[3] = READHEX(p[2]) << 4 | READHEX(p[3]);
+       addr->c[4] = READHEX(p[5]) << 4 | READHEX(p[6]);
+       addr->c[5] = READHEX(p[7]) << 4 | READHEX(p[8]);
+       return (0);
+}
+
+/*
+ * Convert a Metricom Address to a string.
+ */
+
+static __u8 *radio_address_to_string(const MetricomAddress * addr,
+                                    MetricomAddressString * p)
+{
+       sprintf(p->c, "%02X%02X-%02X%02X", addr->c[2], addr->c[3],
+               addr->c[4], addr->c[5]);
+       return (p->c);
+}
+
+/*
+ * Note: Must make sure sx_size is big enough to receive a stuffed
+ * MAX_RECV_MTU packet. Additionally, we also want to ensure that it's
+ * big enough to receive a large radio neighbour list (currently 4K).
+ */
+
+static int allocate_buffers(struct strip *strip_info, int mtu)
+{
+       struct net_device *dev = strip_info->dev;
+       int sx_size = max_t(int, STRIP_ENCAP_SIZE(MAX_RECV_MTU), 4096);
+       int tx_size = STRIP_ENCAP_SIZE(mtu) + MaxCommandStringLength;
+       __u8 *r = kmalloc(MAX_RECV_MTU, GFP_ATOMIC);
+       __u8 *s = kmalloc(sx_size, GFP_ATOMIC);
+       __u8 *t = kmalloc(tx_size, GFP_ATOMIC);
+       if (r && s && t) {
+               strip_info->rx_buff = r;
+               strip_info->sx_buff = s;
+               strip_info->tx_buff = t;
+               strip_info->sx_size = sx_size;
+               strip_info->tx_size = tx_size;
+               strip_info->mtu = dev->mtu = mtu;
+               return (1);
+       }
+       kfree(r);
+       kfree(s);
+       kfree(t);
+       return (0);
+}
+
+/*
+ * MTU has been changed by the IP layer. 
+ * We could be in
+ * an upcall from the tty driver, or in an ip packet queue.
+ */
+static int strip_change_mtu(struct net_device *dev, int new_mtu)
+{
+       struct strip *strip_info = netdev_priv(dev);
+       int old_mtu = strip_info->mtu;
+       unsigned char *orbuff = strip_info->rx_buff;
+       unsigned char *osbuff = strip_info->sx_buff;
+       unsigned char *otbuff = strip_info->tx_buff;
+
+       if (new_mtu > MAX_SEND_MTU) {
+               printk(KERN_ERR
+                      "%s: MTU exceeds maximum allowable (%d), MTU change cancelled.\n",
+                      strip_info->dev->name, MAX_SEND_MTU);
+               return -EINVAL;
+       }
+
+       spin_lock_bh(&strip_lock);
+       if (!allocate_buffers(strip_info, new_mtu)) {
+               printk(KERN_ERR "%s: unable to grow strip buffers, MTU change cancelled.\n",
+                      strip_info->dev->name);
+               spin_unlock_bh(&strip_lock);
+               return -ENOMEM;
+       }
+
+       if (strip_info->sx_count) {
+               if (strip_info->sx_count <= strip_info->sx_size)
+                       memcpy(strip_info->sx_buff, osbuff,
+                              strip_info->sx_count);
+               else {
+                       strip_info->discard = strip_info->sx_count;
+                       strip_info->rx_over_errors++;
+               }
+       }
+
+       if (strip_info->tx_left) {
+               if (strip_info->tx_left <= strip_info->tx_size)
+                       memcpy(strip_info->tx_buff, strip_info->tx_head,
+                              strip_info->tx_left);
+               else {
+                       strip_info->tx_left = 0;
+                       strip_info->tx_dropped++;
+               }
+       }
+       strip_info->tx_head = strip_info->tx_buff;
+       spin_unlock_bh(&strip_lock);
+
+       printk(KERN_NOTICE "%s: strip MTU changed fom %d to %d.\n",
+              strip_info->dev->name, old_mtu, strip_info->mtu);
+
+       kfree(orbuff);
+       kfree(osbuff);
+       kfree(otbuff);
+       return 0;
+}
+
+static void strip_unlock(struct strip *strip_info)
+{
+       /*
+        * Set the timer to go off in one second.
+        */
+       strip_info->idle_timer.expires = jiffies + 1 * HZ;
+       add_timer(&strip_info->idle_timer);
+       netif_wake_queue(strip_info->dev);
+}
+
+
+
+/*
+ * If the time is in the near future, time_delta prints the number of
+ * seconds to go into the buffer and returns the address of the buffer.
+ * If the time is not in the near future, it returns the address of the
+ * string "Not scheduled" The buffer must be long enough to contain the
+ * ascii representation of the number plus 9 charactes for the " seconds"
+ * and the null character.
+ */
+#ifdef CONFIG_PROC_FS
+static char *time_delta(char buffer[], long time)
+{
+       time -= jiffies;
+       if (time > LongTime / 2)
+               return ("Not scheduled");
+       if (time < 0)
+               time = 0;       /* Don't print negative times */
+       sprintf(buffer, "%ld seconds", time / HZ);
+       return (buffer);
+}
+
+/* get Nth element of the linked list */
+static struct strip *strip_get_idx(loff_t pos) 
+{
+       struct strip *str;
+       int i = 0;
+
+       list_for_each_entry_rcu(str, &strip_list, list) {
+               if (pos == i)
+                       return str;
+               ++i;
+       }
+       return NULL;
+}
+
+static void *strip_seq_start(struct seq_file *seq, loff_t *pos)
+{
+       rcu_read_lock();
+       return *pos ? strip_get_idx(*pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *strip_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+       struct list_head *l;
+       struct strip *s;
+
+       ++*pos;
+       if (v == SEQ_START_TOKEN)
+               return strip_get_idx(1);
+
+       s = v;
+       l = &s->list;
+       list_for_each_continue_rcu(l, &strip_list) {
+               return list_entry(l, struct strip, list);
+       }
+       return NULL;
+}
+
+static void strip_seq_stop(struct seq_file *seq, void *v)
+{
+       rcu_read_unlock();
+}
+
+static void strip_seq_neighbours(struct seq_file *seq,
+                          const MetricomNodeTable * table,
+                          const char *title)
+{
+       /* We wrap this in a do/while loop, so if the table changes */
+       /* while we're reading it, we just go around and try again. */
+       struct timeval t;
+
+       do {
+               int i;
+               t = table->timestamp;
+               if (table->num_nodes)
+                       seq_printf(seq, "\n %s\n", title);
+               for (i = 0; i < table->num_nodes; i++) {
+                       MetricomNode node;
+
+                       spin_lock_bh(&strip_lock);
+                       node = table->node[i];
+                       spin_unlock_bh(&strip_lock);
+                       seq_printf(seq, "  %s\n", node.c);
+               }
+       } while (table->timestamp.tv_sec != t.tv_sec
+                || table->timestamp.tv_usec != t.tv_usec);
+}
+
+/*
+ * This function prints radio status information via the seq_file
+ * interface.  The interface takes care of buffer size and over
+ * run issues. 
+ *
+ * The buffer in seq_file is PAGESIZE (4K) 
+ * so this routine should never print more or it will get truncated.
+ * With the maximum of 32 portables and 32 poletops
+ * reported, the routine outputs 3107 bytes into the buffer.
+ */
+static void strip_seq_status_info(struct seq_file *seq, 
+                                 const struct strip *strip_info)
+{
+       char temp[32];
+       MetricomAddressString addr_string;
+
+       /* First, we must copy all of our data to a safe place, */
+       /* in case a serial interrupt comes in and changes it.  */
+       int tx_left = strip_info->tx_left;
+       unsigned long rx_average_pps = strip_info->rx_average_pps;
+       unsigned long tx_average_pps = strip_info->tx_average_pps;
+       unsigned long sx_average_pps = strip_info->sx_average_pps;
+       int working = strip_info->working;
+       int firmware_level = strip_info->firmware_level;
+       long watchdog_doprobe = strip_info->watchdog_doprobe;
+       long watchdog_doreset = strip_info->watchdog_doreset;
+       long gratuitous_arp = strip_info->gratuitous_arp;
+       long arp_interval = strip_info->arp_interval;
+       FirmwareVersion firmware_version = strip_info->firmware_version;
+       SerialNumber serial_number = strip_info->serial_number;
+       BatteryVoltage battery_voltage = strip_info->battery_voltage;
+       char *if_name = strip_info->dev->name;
+       MetricomAddress true_dev_addr = strip_info->true_dev_addr;
+       MetricomAddress dev_dev_addr =
+           *(MetricomAddress *) strip_info->dev->dev_addr;
+       int manual_dev_addr = strip_info->manual_dev_addr;
+#ifdef EXT_COUNTERS
+       unsigned long rx_bytes = strip_info->rx_bytes;
+       unsigned long tx_bytes = strip_info->tx_bytes;
+       unsigned long rx_rbytes = strip_info->rx_rbytes;
+       unsigned long tx_rbytes = strip_info->tx_rbytes;
+       unsigned long rx_sbytes = strip_info->rx_sbytes;
+       unsigned long tx_sbytes = strip_info->tx_sbytes;
+       unsigned long rx_ebytes = strip_info->rx_ebytes;
+       unsigned long tx_ebytes = strip_info->tx_ebytes;
+#endif
+
+       seq_printf(seq, "\nInterface name\t\t%s\n", if_name);
+       seq_printf(seq, " Radio working:\t\t%s\n", working ? "Yes" : "No");
+       radio_address_to_string(&true_dev_addr, &addr_string);
+       seq_printf(seq, " Radio address:\t\t%s\n", addr_string.c);
+       if (manual_dev_addr) {
+               radio_address_to_string(&dev_dev_addr, &addr_string);
+               seq_printf(seq, " Device address:\t%s\n", addr_string.c);
+       }
+       seq_printf(seq, " Firmware version:\t%s", !working ? "Unknown" :
+                    !firmware_level ? "Should be upgraded" :
+                    firmware_version.c);
+       if (firmware_level >= ChecksummedMessages)
+               seq_printf(seq, " (Checksums Enabled)");
+       seq_printf(seq, "\n");
+       seq_printf(seq, " Serial number:\t\t%s\n", serial_number.c);
+       seq_printf(seq, " Battery voltage:\t%s\n", battery_voltage.c);
+       seq_printf(seq, " Transmit queue (bytes):%d\n", tx_left);
+       seq_printf(seq, " Receive packet rate:   %ld packets per second\n",
+                    rx_average_pps / 8);
+       seq_printf(seq, " Transmit packet rate:  %ld packets per second\n",
+                    tx_average_pps / 8);
+       seq_printf(seq, " Sent packet rate:      %ld packets per second\n",
+                    sx_average_pps / 8);
+       seq_printf(seq, " Next watchdog probe:\t%s\n",
+                    time_delta(temp, watchdog_doprobe));
+       seq_printf(seq, " Next watchdog reset:\t%s\n",
+                    time_delta(temp, watchdog_doreset));
+       seq_printf(seq, " Next gratuitous ARP:\t");
+
+       if (!memcmp
+           (strip_info->dev->dev_addr, zero_address.c,
+            sizeof(zero_address)))
+               seq_printf(seq, "Disabled\n");
+       else {
+               seq_printf(seq, "%s\n", time_delta(temp, gratuitous_arp));
+               seq_printf(seq, " Next ARP interval:\t%ld seconds\n",
+                            JIFFIE_TO_SEC(arp_interval));
+       }
+
+       if (working) {
+#ifdef EXT_COUNTERS
+               seq_printf(seq, "\n");
+               seq_printf(seq,
+                            " Total bytes:         \trx:\t%lu\ttx:\t%lu\n",
+                            rx_bytes, tx_bytes);
+               seq_printf(seq,
+                            "  thru radio:         \trx:\t%lu\ttx:\t%lu\n",
+                            rx_rbytes, tx_rbytes);
+               seq_printf(seq,
+                            "  thru serial port:   \trx:\t%lu\ttx:\t%lu\n",
+                            rx_sbytes, tx_sbytes);
+               seq_printf(seq,
+                            " Total stat/err bytes:\trx:\t%lu\ttx:\t%lu\n",
+                            rx_ebytes, tx_ebytes);
+#endif
+               strip_seq_neighbours(seq, &strip_info->poletops,
+                                       "Poletops:");
+               strip_seq_neighbours(seq, &strip_info->portables,
+                                       "Portables:");
+       }
+}
+
+/*
+ * This function is exports status information from the STRIP driver through
+ * the /proc file system.
+ */
+static int strip_seq_show(struct seq_file *seq, void *v)
+{
+       if (v == SEQ_START_TOKEN)
+               seq_printf(seq, "strip_version: %s\n", StripVersion);
+       else
+               strip_seq_status_info(seq, (const struct strip *)v);
+       return 0;
+}
+
+
+static struct seq_operations strip_seq_ops = {
+       .start = strip_seq_start,
+       .next  = strip_seq_next,
+       .stop  = strip_seq_stop,
+       .show  = strip_seq_show,
+};
+
+static int strip_seq_open(struct inode *inode, struct file *file)
+{
+       return seq_open(file, &strip_seq_ops);
+}
+
+static const struct file_operations strip_seq_fops = {
+       .owner   = THIS_MODULE,
+       .open    = strip_seq_open,
+       .read    = seq_read,
+       .llseek  = seq_lseek,
+       .release = seq_release,
+};
+#endif
+
+
+
+/************************************************************************/
+/* Sending routines                                                    */
+
+static void ResetRadio(struct strip *strip_info)
+{
+       struct tty_struct *tty = strip_info->tty;
+       static const char init[] = "ate0q1dt**starmode\r**";
+       StringDescriptor s = { init, sizeof(init) - 1 };
+
+       /* 
+        * If the radio isn't working anymore,
+        * we should clear the old status information.
+        */
+       if (strip_info->working) {
+               printk(KERN_INFO "%s: No response: Resetting radio.\n",
+                      strip_info->dev->name);
+               strip_info->firmware_version.c[0] = '\0';
+               strip_info->serial_number.c[0] = '\0';
+               strip_info->battery_voltage.c[0] = '\0';
+               strip_info->portables.num_nodes = 0;
+               do_gettimeofday(&strip_info->portables.timestamp);
+               strip_info->poletops.num_nodes = 0;
+               do_gettimeofday(&strip_info->poletops.timestamp);
+       }
+
+       strip_info->pps_timer = jiffies;
+       strip_info->rx_pps_count = 0;
+       strip_info->tx_pps_count = 0;
+       strip_info->sx_pps_count = 0;
+       strip_info->rx_average_pps = 0;
+       strip_info->tx_average_pps = 0;
+       strip_info->sx_average_pps = 0;
+
+       /* Mark radio address as unknown */
+       *(MetricomAddress *) & strip_info->true_dev_addr = zero_address;
+       if (!strip_info->manual_dev_addr)
+               *(MetricomAddress *) strip_info->dev->dev_addr =
+                   zero_address;
+       strip_info->working = FALSE;
+       strip_info->firmware_level = NoStructure;
+       strip_info->next_command = CompatibilityCommand;
+       strip_info->watchdog_doprobe = jiffies + 10 * HZ;
+       strip_info->watchdog_doreset = jiffies + 1 * HZ;
+
+       /* If the user has selected a baud rate above 38.4 see what magic we have to do */
+       if (strip_info->user_baud > 38400) {
+               /*
+                * Subtle stuff: Pay attention :-)
+                * If the serial port is currently at the user's selected (>38.4) rate,
+                * then we temporarily switch to 19.2 and issue the ATS304 command
+                * to tell the radio to switch to the user's selected rate.
+                * If the serial port is not currently at that rate, that means we just
+                * issued the ATS304 command last time through, so this time we restore
+                * the user's selected rate and issue the normal starmode reset string.
+                */
+               if (strip_info->user_baud == tty_get_baud_rate(tty)) {
+                       static const char b0[] = "ate0q1s304=57600\r";
+                       static const char b1[] = "ate0q1s304=115200\r";
+                       static const StringDescriptor baudstring[2] =
+                           { {b0, sizeof(b0) - 1}
+                       , {b1, sizeof(b1) - 1}
+                       };
+                       set_baud(tty, 19200);
+                       if (strip_info->user_baud == 57600)
+                               s = baudstring[0];
+                       else if (strip_info->user_baud == 115200)
+                               s = baudstring[1];
+                       else
+                               s = baudstring[1];      /* For now */
+               } else
+                       set_baud(tty, strip_info->user_baud);
+       }
+
+       tty->ops->write(tty, s.string, s.length);
+#ifdef EXT_COUNTERS
+       strip_info->tx_ebytes += s.length;
+#endif
+}
+
+/*
+ * Called by the driver when there's room for more data.  If we have
+ * more packets to send, we send them here.
+ */
+
+static void strip_write_some_more(struct tty_struct *tty)
+{
+       struct strip *strip_info = (struct strip *) tty->disc_data;
+
+       /* First make sure we're connected. */
+       if (!strip_info || strip_info->magic != STRIP_MAGIC ||
+           !netif_running(strip_info->dev))
+               return;
+
+       if (strip_info->tx_left > 0) {
+               int num_written =
+                   tty->ops->write(tty, strip_info->tx_head,
+                                     strip_info->tx_left);
+               strip_info->tx_left -= num_written;
+               strip_info->tx_head += num_written;
+#ifdef EXT_COUNTERS
+               strip_info->tx_sbytes += num_written;
+#endif
+       } else {                /* Else start transmission of another packet */
+
+               tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
+               strip_unlock(strip_info);
+       }
+}
+
+static __u8 *add_checksum(__u8 * buffer, __u8 * end)
+{
+       __u16 sum = 0;
+       __u8 *p = buffer;
+       while (p < end)
+               sum += *p++;
+       end[3] = hextable[sum & 0xF];
+       sum >>= 4;
+       end[2] = hextable[sum & 0xF];
+       sum >>= 4;
+       end[1] = hextable[sum & 0xF];
+       sum >>= 4;
+       end[0] = hextable[sum & 0xF];
+       return (end + 4);
+}
+
+static unsigned char *strip_make_packet(unsigned char *buffer,
+                                       struct strip *strip_info,
+                                       struct sk_buff *skb)
+{
+       __u8 *ptr = buffer;
+       __u8 *stuffstate = NULL;
+       STRIP_Header *header = (STRIP_Header *) skb->data;
+       MetricomAddress haddr = header->dst_addr;
+       int len = skb->len - sizeof(STRIP_Header);
+       MetricomKey key;
+
+       /*HexDump("strip_make_packet", strip_info, skb->data, skb->data + skb->len); */
+
+       if (header->protocol == htons(ETH_P_IP))
+               key = SIP0Key;
+       else if (header->protocol == htons(ETH_P_ARP))
+               key = ARP0Key;
+       else {
+               printk(KERN_ERR
+                      "%s: strip_make_packet: Unknown packet type 0x%04X\n",
+                      strip_info->dev->name, ntohs(header->protocol));
+               return (NULL);
+       }
+
+       if (len > strip_info->mtu) {
+               printk(KERN_ERR
+                      "%s: Dropping oversized transmit packet: %d bytes\n",
+                      strip_info->dev->name, len);
+               return (NULL);
+       }
+
+       /*
+        * If we're sending to ourselves, discard the packet.
+        * (Metricom radios choke if they try to send a packet to their own address.)
+        */
+       if (!memcmp(haddr.c, strip_info->true_dev_addr.c, sizeof(haddr))) {
+               printk(KERN_ERR "%s: Dropping packet addressed to self\n",
+                      strip_info->dev->name);
+               return (NULL);
+       }
+
+       /*
+        * If this is a broadcast packet, send it to our designated Metricom
+        * 'broadcast hub' radio (First byte of address being 0xFF means broadcast)
+        */
+       if (haddr.c[0] == 0xFF) {
+               __be32 brd = 0;
+               struct in_device *in_dev;
+
+               rcu_read_lock();
+               in_dev = __in_dev_get_rcu(strip_info->dev);
+               if (in_dev == NULL) {
+                       rcu_read_unlock();
+                       return NULL;
+               }
+               if (in_dev->ifa_list)
+                       brd = in_dev->ifa_list->ifa_broadcast;
+               rcu_read_unlock();
+
+               /* arp_query returns 1 if it succeeds in looking up the address, 0 if it fails */
+               if (!arp_query(haddr.c, brd, strip_info->dev)) {
+                       printk(KERN_ERR
+                              "%s: Unable to send packet (no broadcast hub configured)\n",
+                              strip_info->dev->name);
+                       return (NULL);
+               }
+               /*
+                * If we are the broadcast hub, don't bother sending to ourselves.
+                * (Metricom radios choke if they try to send a packet to their own address.)
+                */
+               if (!memcmp
+                   (haddr.c, strip_info->true_dev_addr.c, sizeof(haddr)))
+                       return (NULL);
+       }
+
+       *ptr++ = 0x0D;
+       *ptr++ = '*';
+       *ptr++ = hextable[haddr.c[2] >> 4];
+       *ptr++ = hextable[haddr.c[2] & 0xF];
+       *ptr++ = hextable[haddr.c[3] >> 4];
+       *ptr++ = hextable[haddr.c[3] & 0xF];
+       *ptr++ = '-';
+       *ptr++ = hextable[haddr.c[4] >> 4];
+       *ptr++ = hextable[haddr.c[4] & 0xF];
+       *ptr++ = hextable[haddr.c[5] >> 4];
+       *ptr++ = hextable[haddr.c[5] & 0xF];
+       *ptr++ = '*';
+       *ptr++ = key.c[0];
+       *ptr++ = key.c[1];
+       *ptr++ = key.c[2];
+       *ptr++ = key.c[3];
+
+       ptr =
+           StuffData(skb->data + sizeof(STRIP_Header), len, ptr,
+                     &stuffstate);
+
+       if (strip_info->firmware_level >= ChecksummedMessages)
+               ptr = add_checksum(buffer + 1, ptr);
+
+       *ptr++ = 0x0D;
+       return (ptr);
+}
+
+static void strip_send(struct strip *strip_info, struct sk_buff *skb)
+{
+       MetricomAddress haddr;
+       unsigned char *ptr = strip_info->tx_buff;
+       int doreset = (long) jiffies - strip_info->watchdog_doreset >= 0;
+       int doprobe = (long) jiffies - strip_info->watchdog_doprobe >= 0
+           && !doreset;
+       __be32 addr, brd;
+
+       /*
+        * 1. If we have a packet, encapsulate it and put it in the buffer
+        */
+       if (skb) {
+               char *newptr = strip_make_packet(ptr, strip_info, skb);
+               strip_info->tx_pps_count++;
+               if (!newptr)
+                       strip_info->tx_dropped++;
+               else {
+                       ptr = newptr;
+                       strip_info->sx_pps_count++;
+                       strip_info->tx_packets++;       /* Count another successful packet */
+#ifdef EXT_COUNTERS
+                       strip_info->tx_bytes += skb->len;
+                       strip_info->tx_rbytes += ptr - strip_info->tx_buff;
+#endif
+                       /*DumpData("Sending:", strip_info, strip_info->tx_buff, ptr); */
+                       /*HexDump("Sending", strip_info, strip_info->tx_buff, ptr); */
+               }
+       }
+
+       /*
+        * 2. If it is time for another tickle, tack it on, after the packet
+        */
+       if (doprobe) {
+               StringDescriptor ts = CommandString[strip_info->next_command];
+#if TICKLE_TIMERS
+               {
+                       struct timeval tv;
+                       do_gettimeofday(&tv);
+                       printk(KERN_INFO "**** Sending tickle string %d      at %02d.%06d\n",
+                              strip_info->next_command, tv.tv_sec % 100,
+                              tv.tv_usec);
+               }
+#endif
+               if (ptr == strip_info->tx_buff)
+                       *ptr++ = 0x0D;
+
+               *ptr++ = '*';   /* First send "**" to provoke an error message */
+               *ptr++ = '*';
+
+               /* Then add the command */
+               memcpy(ptr, ts.string, ts.length);
+
+               /* Add a checksum ? */
+               if (strip_info->firmware_level < ChecksummedMessages)
+                       ptr += ts.length;
+               else
+                       ptr = add_checksum(ptr, ptr + ts.length);
+
+               *ptr++ = 0x0D;  /* Terminate the command with a <CR> */
+
+               /* Cycle to next periodic command? */
+               if (strip_info->firmware_level >= StructuredMessages)
+                       if (++strip_info->next_command >=
+                           ARRAY_SIZE(CommandString))
+                               strip_info->next_command = 0;
+#ifdef EXT_COUNTERS
+               strip_info->tx_ebytes += ts.length;
+#endif
+               strip_info->watchdog_doprobe = jiffies + 10 * HZ;
+               strip_info->watchdog_doreset = jiffies + 1 * HZ;
+               /*printk(KERN_INFO "%s: Routine radio test.\n", strip_info->dev->name); */
+       }
+
+       /*
+        * 3. Set up the strip_info ready to send the data (if any).
+        */
+       strip_info->tx_head = strip_info->tx_buff;
+       strip_info->tx_left = ptr - strip_info->tx_buff;
+       strip_info->tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
+
+       /*
+        * 4. Debugging check to make sure we're not overflowing the buffer.
+        */
+       if (strip_info->tx_size - strip_info->tx_left < 20)
+               printk(KERN_ERR "%s: Sending%5d bytes;%5d bytes free.\n",
+                      strip_info->dev->name, strip_info->tx_left,
+                      strip_info->tx_size - strip_info->tx_left);
+
+       /*
+        * 5. If watchdog has expired, reset the radio. Note: if there's data waiting in
+        * the buffer, strip_write_some_more will send it after the reset has finished
+        */
+       if (doreset) {
+               ResetRadio(strip_info);
+               return;
+       }
+
+       if (1) {
+               struct in_device *in_dev;
+
+               brd = addr = 0;
+               rcu_read_lock();
+               in_dev = __in_dev_get_rcu(strip_info->dev);
+               if (in_dev) {
+                       if (in_dev->ifa_list) {
+                               brd = in_dev->ifa_list->ifa_broadcast;
+                               addr = in_dev->ifa_list->ifa_local;
+                       }
+               }
+               rcu_read_unlock();
+       }
+
+
+       /*
+        * 6. If it is time for a periodic ARP, queue one up to be sent.
+        * We only do this if:
+        *  1. The radio is working
+        *  2. It's time to send another periodic ARP
+        *  3. We really know what our address is (and it is not manually set to zero)
+        *  4. We have a designated broadcast address configured
+        * If we queue up an ARP packet when we don't have a designated broadcast
+        * address configured, then the packet will just have to be discarded in
+        * strip_make_packet. This is not fatal, but it causes misleading information
+        * to be displayed in tcpdump. tcpdump will report that periodic APRs are
+        * being sent, when in fact they are not, because they are all being dropped
+        * in the strip_make_packet routine.
+        */
+       if (strip_info->working
+           && (long) jiffies - strip_info->gratuitous_arp >= 0
+           && memcmp(strip_info->dev->dev_addr, zero_address.c,
+                     sizeof(zero_address))
+           && arp_query(haddr.c, brd, strip_info->dev)) {
+               /*printk(KERN_INFO "%s: Sending gratuitous ARP with interval %ld\n",
+                  strip_info->dev->name, strip_info->arp_interval / HZ); */
+               strip_info->gratuitous_arp =
+                   jiffies + strip_info->arp_interval;
+               strip_info->arp_interval *= 2;
+               if (strip_info->arp_interval > MaxARPInterval)
+                       strip_info->arp_interval = MaxARPInterval;
+               if (addr)
+                       arp_send(ARPOP_REPLY, ETH_P_ARP, addr,  /* Target address of ARP packet is our address */
+                                strip_info->dev,       /* Device to send packet on */
+                                addr,  /* Source IP address this ARP packet comes from */
+                                NULL,  /* Destination HW address is NULL (broadcast it) */
+                                strip_info->dev->dev_addr,     /* Source HW address is our HW address */
+                                strip_info->dev->dev_addr);    /* Target HW address is our HW address (redundant) */
+       }
+
+       /*
+        * 7. All ready. Start the transmission
+        */
+       strip_write_some_more(strip_info->tty);
+}
+
+/* Encapsulate a datagram and kick it into a TTY queue. */
+static int strip_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       struct strip *strip_info = netdev_priv(dev);
+
+       if (!netif_running(dev)) {
+               printk(KERN_ERR "%s: xmit call when iface is down\n",
+                      dev->name);
+               return (1);
+       }
+
+       netif_stop_queue(dev);
+
+       del_timer(&strip_info->idle_timer);
+
+
+       if (time_after(jiffies, strip_info->pps_timer + HZ)) {
+               unsigned long t = jiffies - strip_info->pps_timer;
+               unsigned long rx_pps_count = (strip_info->rx_pps_count * HZ * 8 + t / 2) / t;
+               unsigned long tx_pps_count = (strip_info->tx_pps_count * HZ * 8 + t / 2) / t;
+               unsigned long sx_pps_count = (strip_info->sx_pps_count * HZ * 8 + t / 2) / t;
+
+               strip_info->pps_timer = jiffies;
+               strip_info->rx_pps_count = 0;
+               strip_info->tx_pps_count = 0;
+               strip_info->sx_pps_count = 0;
+
+               strip_info->rx_average_pps = (strip_info->rx_average_pps + rx_pps_count + 1) / 2;
+               strip_info->tx_average_pps = (strip_info->tx_average_pps + tx_pps_count + 1) / 2;
+               strip_info->sx_average_pps = (strip_info->sx_average_pps + sx_pps_count + 1) / 2;
+
+               if (rx_pps_count / 8 >= 10)
+                       printk(KERN_INFO "%s: WARNING: Receiving %ld packets per second.\n",
+                              strip_info->dev->name, rx_pps_count / 8);
+               if (tx_pps_count / 8 >= 10)
+                       printk(KERN_INFO "%s: WARNING: Tx        %ld packets per second.\n",
+                              strip_info->dev->name, tx_pps_count / 8);
+               if (sx_pps_count / 8 >= 10)
+                       printk(KERN_INFO "%s: WARNING: Sending   %ld packets per second.\n",
+                              strip_info->dev->name, sx_pps_count / 8);
+       }
+
+       spin_lock_bh(&strip_lock);
+
+       strip_send(strip_info, skb);
+
+       spin_unlock_bh(&strip_lock);
+
+       if (skb)
+               dev_kfree_skb(skb);
+       return 0;
+}
+
+/*
+ * IdleTask periodically calls strip_xmit, so even when we have no IP packets
+ * to send for an extended period of time, the watchdog processing still gets
+ * done to ensure that the radio stays in Starmode
+ */
+
+static void strip_IdleTask(unsigned long parameter)
+{
+       strip_xmit(NULL, (struct net_device *) parameter);
+}
+
+/*
+ * Create the MAC header for an arbitrary protocol layer
+ *
+ * saddr!=NULL        means use this specific address (n/a for Metricom)
+ * saddr==NULL        means use default device source address
+ * daddr!=NULL        means use this destination address
+ * daddr==NULL        means leave destination address alone
+ *                 (e.g. unresolved arp -- kernel will call
+ *                 rebuild_header later to fill in the address)
+ */
+
+static int strip_header(struct sk_buff *skb, struct net_device *dev,
+                       unsigned short type, const void *daddr,
+                       const void *saddr, unsigned len)
+{
+       struct strip *strip_info = netdev_priv(dev);
+       STRIP_Header *header = (STRIP_Header *) skb_push(skb, sizeof(STRIP_Header));
+
+       /*printk(KERN_INFO "%s: strip_header 0x%04X %s\n", dev->name, type,
+          type == ETH_P_IP ? "IP" : type == ETH_P_ARP ? "ARP" : ""); */
+
+       header->src_addr = strip_info->true_dev_addr;
+       header->protocol = htons(type);
+
+       /*HexDump("strip_header", netdev_priv(dev), skb->data, skb->data + skb->len); */
+
+       if (!daddr)
+               return (-dev->hard_header_len);
+
+       header->dst_addr = *(MetricomAddress *) daddr;
+       return (dev->hard_header_len);
+}
+
+/*
+ * Rebuild the MAC header. This is called after an ARP
+ * (or in future other address resolution) has completed on this
+ * sk_buff. We now let ARP fill in the other fields.
+ * I think this should return zero if packet is ready to send,
+ * or non-zero if it needs more time to do an address lookup
+ */
+
+static int strip_rebuild_header(struct sk_buff *skb)
+{
+#ifdef CONFIG_INET
+       STRIP_Header *header = (STRIP_Header *) skb->data;
+
+       /* Arp find returns zero if if knows the address, */
+       /* or if it doesn't know the address it sends an ARP packet and returns non-zero */
+       return arp_find(header->dst_addr.c, skb) ? 1 : 0;
+#else
+       return 0;
+#endif
+}
+
+
+/************************************************************************/
+/* Receiving routines                                                  */
+
+/*
+ * This function parses the response to the ATS300? command,
+ * extracting the radio version and serial number.
+ */
+static void get_radio_version(struct strip *strip_info, __u8 * ptr, __u8 * end)
+{
+       __u8 *p, *value_begin, *value_end;
+       int len;
+
+       /* Determine the beginning of the second line of the payload */
+       p = ptr;
+       while (p < end && *p != 10)
+               p++;
+       if (p >= end)
+               return;
+       p++;
+       value_begin = p;
+
+       /* Determine the end of line */
+       while (p < end && *p != 10)
+               p++;
+       if (p >= end)
+               return;
+       value_end = p;
+       p++;
+
+       len = value_end - value_begin;
+       len = min_t(int, len, sizeof(FirmwareVersion) - 1);
+       if (strip_info->firmware_version.c[0] == 0)
+               printk(KERN_INFO "%s: Radio Firmware: %.*s\n",
+                      strip_info->dev->name, len, value_begin);
+       sprintf(strip_info->firmware_version.c, "%.*s", len, value_begin);
+
+       /* Look for the first colon */
+       while (p < end && *p != ':')
+               p++;
+       if (p >= end)
+               return;
+       /* Skip over the space */
+       p += 2;
+       len = sizeof(SerialNumber) - 1;
+       if (p + len <= end) {
+               sprintf(strip_info->serial_number.c, "%.*s", len, p);
+       } else {
+               printk(KERN_DEBUG
+                      "STRIP: radio serial number shorter (%zd) than expected (%d)\n",
+                      end - p, len);
+       }
+}
+
+/*
+ * This function parses the response to the ATS325? command,
+ * extracting the radio battery voltage.
+ */
+static void get_radio_voltage(struct strip *strip_info, __u8 * ptr, __u8 * end)
+{
+       int len;
+
+       len = sizeof(BatteryVoltage) - 1;
+       if (ptr + len <= end) {
+               sprintf(strip_info->battery_voltage.c, "%.*s", len, ptr);
+       } else {
+               printk(KERN_DEBUG
+                      "STRIP: radio voltage string shorter (%zd) than expected (%d)\n",
+                      end - ptr, len);
+       }
+}
+
+/*
+ * This function parses the responses to the AT~LA and ATS311 commands,
+ * which list the radio's neighbours.
+ */
+static void get_radio_neighbours(MetricomNodeTable * table, __u8 * ptr, __u8 * end)
+{
+       table->num_nodes = 0;
+       while (ptr < end && table->num_nodes < NODE_TABLE_SIZE) {
+               MetricomNode *node = &table->node[table->num_nodes++];
+               char *dst = node->c, *limit = dst + sizeof(*node) - 1;
+               while (ptr < end && *ptr <= 32)
+                       ptr++;
+               while (ptr < end && dst < limit && *ptr != 10)
+                       *dst++ = *ptr++;
+               *dst++ = 0;
+               while (ptr < end && ptr[-1] != 10)
+                       ptr++;
+       }
+       do_gettimeofday(&table->timestamp);
+}
+
+static int get_radio_address(struct strip *strip_info, __u8 * p)
+{
+       MetricomAddress addr;
+
+       if (string_to_radio_address(&addr, p))
+               return (1);
+
+       /* See if our radio address has changed */
+       if (memcmp(strip_info->true_dev_addr.c, addr.c, sizeof(addr))) {
+               MetricomAddressString addr_string;
+               radio_address_to_string(&addr, &addr_string);
+               printk(KERN_INFO "%s: Radio address = %s\n",
+                      strip_info->dev->name, addr_string.c);
+               strip_info->true_dev_addr = addr;
+               if (!strip_info->manual_dev_addr)
+                       *(MetricomAddress *) strip_info->dev->dev_addr =
+                           addr;
+               /* Give the radio a few seconds to get its head straight, then send an arp */
+               strip_info->gratuitous_arp = jiffies + 15 * HZ;
+               strip_info->arp_interval = 1 * HZ;
+       }
+       return (0);
+}
+
+static int verify_checksum(struct strip *strip_info)
+{
+       __u8 *p = strip_info->sx_buff;
+       __u8 *end = strip_info->sx_buff + strip_info->sx_count - 4;
+       u_short sum =
+           (READHEX16(end[0]) << 12) | (READHEX16(end[1]) << 8) |
+           (READHEX16(end[2]) << 4) | (READHEX16(end[3]));
+       while (p < end)
+               sum -= *p++;
+       if (sum == 0 && strip_info->firmware_level == StructuredMessages) {
+               strip_info->firmware_level = ChecksummedMessages;
+               printk(KERN_INFO "%s: Radio provides message checksums\n",
+                      strip_info->dev->name);
+       }
+       return (sum == 0);
+}
+
+static void RecvErr(char *msg, struct strip *strip_info)
+{
+       __u8 *ptr = strip_info->sx_buff;
+       __u8 *end = strip_info->sx_buff + strip_info->sx_count;
+       DumpData(msg, strip_info, ptr, end);
+       strip_info->rx_errors++;
+}
+
+static void RecvErr_Message(struct strip *strip_info, __u8 * sendername,
+                           const __u8 * msg, u_long len)
+{
+       if (has_prefix(msg, len, "001")) {      /* Not in StarMode! */
+               RecvErr("Error Msg:", strip_info);
+               printk(KERN_INFO "%s: Radio %s is not in StarMode\n",
+                      strip_info->dev->name, sendername);
+       }
+
+       else if (has_prefix(msg, len, "002")) { /* Remap handle */
+               /* We ignore "Remap handle" messages for now */
+       }
+
+       else if (has_prefix(msg, len, "003")) { /* Can't resolve name */
+               RecvErr("Error Msg:", strip_info);
+               printk(KERN_INFO "%s: Destination radio name is unknown\n",
+                      strip_info->dev->name);
+       }
+
+       else if (has_prefix(msg, len, "004")) { /* Name too small or missing */
+               strip_info->watchdog_doreset = jiffies + LongTime;
+#if TICKLE_TIMERS
+               {
+                       struct timeval tv;
+                       do_gettimeofday(&tv);
+                       printk(KERN_INFO
+                              "**** Got ERR_004 response         at %02d.%06d\n",
+                              tv.tv_sec % 100, tv.tv_usec);
+               }
+#endif
+               if (!strip_info->working) {
+                       strip_info->working = TRUE;
+                       printk(KERN_INFO "%s: Radio now in starmode\n",
+                              strip_info->dev->name);
+                       /*
+                        * If the radio has just entered a working state, we should do our first
+                        * probe ASAP, so that we find out our radio address etc. without delay.
+                        */
+                       strip_info->watchdog_doprobe = jiffies;
+               }
+               if (strip_info->firmware_level == NoStructure && sendername) {
+                       strip_info->firmware_level = StructuredMessages;
+                       strip_info->next_command = 0;   /* Try to enable checksums ASAP */
+                       printk(KERN_INFO
+                              "%s: Radio provides structured messages\n",
+                              strip_info->dev->name);
+               }
+               if (strip_info->firmware_level >= StructuredMessages) {
+                       /*
+                        * If this message has a valid checksum on the end, then the call to verify_checksum
+                        * will elevate the firmware_level to ChecksummedMessages for us. (The actual return
+                        * code from verify_checksum is ignored here.)
+                        */
+                       verify_checksum(strip_info);
+                       /*
+                        * If the radio has structured messages but we don't yet have all our information about it,
+                        * we should do probes without delay, until we have gathered all the information
+                        */
+                       if (!GOT_ALL_RADIO_INFO(strip_info))
+                               strip_info->watchdog_doprobe = jiffies;
+               }
+       }
+
+       else if (has_prefix(msg, len, "005"))   /* Bad count specification */
+               RecvErr("Error Msg:", strip_info);
+
+       else if (has_prefix(msg, len, "006"))   /* Header too big */
+               RecvErr("Error Msg:", strip_info);
+
+       else if (has_prefix(msg, len, "007")) { /* Body too big */
+               RecvErr("Error Msg:", strip_info);
+               printk(KERN_ERR
+                      "%s: Error! Packet size too big for radio.\n",
+                      strip_info->dev->name);
+       }
+
+       else if (has_prefix(msg, len, "008")) { /* Bad character in name */
+               RecvErr("Error Msg:", strip_info);
+               printk(KERN_ERR
+                      "%s: Radio name contains illegal character\n",
+                      strip_info->dev->name);
+       }
+
+       else if (has_prefix(msg, len, "009"))   /* No count or line terminator */
+               RecvErr("Error Msg:", strip_info);
+
+       else if (has_prefix(msg, len, "010"))   /* Invalid checksum */
+               RecvErr("Error Msg:", strip_info);
+
+       else if (has_prefix(msg, len, "011"))   /* Checksum didn't match */
+               RecvErr("Error Msg:", strip_info);
+
+       else if (has_prefix(msg, len, "012"))   /* Failed to transmit packet */
+               RecvErr("Error Msg:", strip_info);
+
+       else
+               RecvErr("Error Msg:", strip_info);
+}
+
+static void process_AT_response(struct strip *strip_info, __u8 * ptr,
+                               __u8 * end)
+{
+       u_long len;
+       __u8 *p = ptr;
+       while (p < end && p[-1] != 10)
+               p++;            /* Skip past first newline character */
+       /* Now ptr points to the AT command, and p points to the text of the response. */
+       len = p - ptr;
+
+#if TICKLE_TIMERS
+       {
+               struct timeval tv;
+               do_gettimeofday(&tv);
+               printk(KERN_INFO "**** Got AT response %.7s      at %02d.%06d\n",
+                      ptr, tv.tv_sec % 100, tv.tv_usec);
+       }
+#endif
+
+       if (has_prefix(ptr, len, "ATS300?"))
+               get_radio_version(strip_info, p, end);
+       else if (has_prefix(ptr, len, "ATS305?"))
+               get_radio_address(strip_info, p);
+       else if (has_prefix(ptr, len, "ATS311?"))
+               get_radio_neighbours(&strip_info->poletops, p, end);
+       else if (has_prefix(ptr, len, "ATS319=7"))
+               verify_checksum(strip_info);
+       else if (has_prefix(ptr, len, "ATS325?"))
+               get_radio_voltage(strip_info, p, end);
+       else if (has_prefix(ptr, len, "AT~LA"))
+               get_radio_neighbours(&strip_info->portables, p, end);
+       else
+               RecvErr("Unknown AT Response:", strip_info);
+}
+
+static void process_ACK(struct strip *strip_info, __u8 * ptr, __u8 * end)
+{
+       /* Currently we don't do anything with ACKs from the radio */
+}
+
+static void process_Info(struct strip *strip_info, __u8 * ptr, __u8 * end)
+{
+       if (ptr + 16 > end)
+               RecvErr("Bad Info Msg:", strip_info);
+}
+
+static struct net_device *get_strip_dev(struct strip *strip_info)
+{
+       /* If our hardware address is *manually set* to zero, and we know our */
+       /* real radio hardware address, try to find another strip device that has been */
+       /* manually set to that address that we can 'transfer ownership' of this packet to  */
+       if (strip_info->manual_dev_addr &&
+           !memcmp(strip_info->dev->dev_addr, zero_address.c,
+                   sizeof(zero_address))
+           && memcmp(&strip_info->true_dev_addr, zero_address.c,
+                     sizeof(zero_address))) {
+               struct net_device *dev;
+               read_lock_bh(&dev_base_lock);
+               for_each_netdev(&init_net, dev) {
+                       if (dev->type == strip_info->dev->type &&
+                           !memcmp(dev->dev_addr,
+                                   &strip_info->true_dev_addr,
+                                   sizeof(MetricomAddress))) {
+                               printk(KERN_INFO
+                                      "%s: Transferred packet ownership to %s.\n",
+                                      strip_info->dev->name, dev->name);
+                               read_unlock_bh(&dev_base_lock);
+                               return (dev);
+                       }
+               }
+               read_unlock_bh(&dev_base_lock);
+       }
+       return (strip_info->dev);
+}
+
+/*
+ * Send one completely decapsulated datagram to the next layer.
+ */
+
+static void deliver_packet(struct strip *strip_info, STRIP_Header * header,
+                          __u16 packetlen)
+{
+       struct sk_buff *skb = dev_alloc_skb(sizeof(STRIP_Header) + packetlen);
+       if (!skb) {
+               printk(KERN_ERR "%s: memory squeeze, dropping packet.\n",
+                      strip_info->dev->name);
+               strip_info->rx_dropped++;
+       } else {
+               memcpy(skb_put(skb, sizeof(STRIP_Header)), header,
+                      sizeof(STRIP_Header));
+               memcpy(skb_put(skb, packetlen), strip_info->rx_buff,
+                      packetlen);
+               skb->dev = get_strip_dev(strip_info);
+               skb->protocol = header->protocol;
+               skb_reset_mac_header(skb);
+
+               /* Having put a fake header on the front of the sk_buff for the */
+               /* benefit of tools like tcpdump, skb_pull now 'consumes' that  */
+               /* fake header before we hand the packet up to the next layer.  */
+               skb_pull(skb, sizeof(STRIP_Header));
+
+               /* Finally, hand the packet up to the next layer (e.g. IP or ARP, etc.) */
+               strip_info->rx_packets++;
+               strip_info->rx_pps_count++;
+#ifdef EXT_COUNTERS
+               strip_info->rx_bytes += packetlen;
+#endif
+               skb->dev->last_rx = jiffies;
+               netif_rx(skb);
+       }
+}
+
+static void process_IP_packet(struct strip *strip_info,
+                             STRIP_Header * header, __u8 * ptr,
+                             __u8 * end)
+{
+       __u16 packetlen;
+
+       /* Decode start of the IP packet header */
+       ptr = UnStuffData(ptr, end, strip_info->rx_buff, 4);
+       if (!ptr) {
+               RecvErr("IP Packet too short", strip_info);
+               return;
+       }
+
+       packetlen = ((__u16) strip_info->rx_buff[2] << 8) | strip_info->rx_buff[3];
+
+       if (packetlen > MAX_RECV_MTU) {
+               printk(KERN_INFO "%s: Dropping oversized received IP packet: %d bytes\n",
+                      strip_info->dev->name, packetlen);
+               strip_info->rx_dropped++;
+               return;
+       }
+
+       /*printk(KERN_INFO "%s: Got %d byte IP packet\n", strip_info->dev->name, packetlen); */
+
+       /* Decode remainder of the IP packet */
+       ptr =
+           UnStuffData(ptr, end, strip_info->rx_buff + 4, packetlen - 4);
+       if (!ptr) {
+               RecvErr("IP Packet too short", strip_info);
+               return;
+       }
+
+       if (ptr < end) {
+               RecvErr("IP Packet too long", strip_info);
+               return;
+       }
+
+       header->protocol = htons(ETH_P_IP);
+
+       deliver_packet(strip_info, header, packetlen);
+}
+
+static void process_ARP_packet(struct strip *strip_info,
+                              STRIP_Header * header, __u8 * ptr,
+                              __u8 * end)
+{
+       __u16 packetlen;
+       struct arphdr *arphdr = (struct arphdr *) strip_info->rx_buff;
+
+       /* Decode start of the ARP packet */
+       ptr = UnStuffData(ptr, end, strip_info->rx_buff, 8);
+       if (!ptr) {
+               RecvErr("ARP Packet too short", strip_info);
+               return;
+       }
+
+       packetlen = 8 + (arphdr->ar_hln + arphdr->ar_pln) * 2;
+
+       if (packetlen > MAX_RECV_MTU) {
+               printk(KERN_INFO
+                      "%s: Dropping oversized received ARP packet: %d bytes\n",
+                      strip_info->dev->name, packetlen);
+               strip_info->rx_dropped++;
+               return;
+       }
+
+       /*printk(KERN_INFO "%s: Got %d byte ARP %s\n",
+          strip_info->dev->name, packetlen,
+          ntohs(arphdr->ar_op) == ARPOP_REQUEST ? "request" : "reply"); */
+
+       /* Decode remainder of the ARP packet */
+       ptr =
+           UnStuffData(ptr, end, strip_info->rx_buff + 8, packetlen - 8);
+       if (!ptr) {
+               RecvErr("ARP Packet too short", strip_info);
+               return;
+       }
+
+       if (ptr < end) {
+               RecvErr("ARP Packet too long", strip_info);
+               return;
+       }
+
+       header->protocol = htons(ETH_P_ARP);
+
+       deliver_packet(strip_info, header, packetlen);
+}
+
+/*
+ * process_text_message processes a <CR>-terminated block of data received
+ * from the radio that doesn't begin with a '*' character. All normal
+ * Starmode communication messages with the radio begin with a '*',
+ * so any text that does not indicates a serial port error, a radio that
+ * is in Hayes command mode instead of Starmode, or a radio with really
+ * old firmware that doesn't frame its Starmode responses properly.
+ */
+static void process_text_message(struct strip *strip_info)
+{
+       __u8 *msg = strip_info->sx_buff;
+       int len = strip_info->sx_count;
+
+       /* Check for anything that looks like it might be our radio name */
+       /* (This is here for backwards compatibility with old firmware)  */
+       if (len == 9 && get_radio_address(strip_info, msg) == 0)
+               return;
+
+       if (text_equal(msg, len, "OK"))
+               return;         /* Ignore 'OK' responses from prior commands */
+       if (text_equal(msg, len, "ERROR"))
+               return;         /* Ignore 'ERROR' messages */
+       if (has_prefix(msg, len, "ate0q1"))
+               return;         /* Ignore character echo back from the radio */
+
+       /* Catch other error messages */
+       /* (This is here for backwards compatibility with old firmware) */
+       if (has_prefix(msg, len, "ERR_")) {
+               RecvErr_Message(strip_info, NULL, &msg[4], len - 4);
+               return;
+       }
+
+       RecvErr("No initial *", strip_info);
+}
+
+/*
+ * process_message processes a <CR>-terminated block of data received
+ * from the radio. If the radio is not in Starmode or has old firmware,
+ * it may be a line of text in response to an AT command. Ideally, with
+ * a current radio that's properly in Starmode, all data received should
+ * be properly framed and checksummed radio message blocks, containing
+ * either a starmode packet, or a other communication from the radio
+ * firmware, like "INF_" Info messages and &COMMAND responses.
+ */
+static void process_message(struct strip *strip_info)
+{
+       STRIP_Header header = { zero_address, zero_address, 0 };
+       __u8 *ptr = strip_info->sx_buff;
+       __u8 *end = strip_info->sx_buff + strip_info->sx_count;
+       __u8 sendername[32], *sptr = sendername;
+       MetricomKey key;
+
+       /*HexDump("Receiving", strip_info, ptr, end); */
+
+       /* Check for start of address marker, and then skip over it */
+       if (*ptr == '*')
+               ptr++;
+       else {
+               process_text_message(strip_info);
+               return;
+       }
+
+       /* Copy out the return address */
+       while (ptr < end && *ptr != '*'
+              && sptr < ARRAY_END(sendername) - 1)
+               *sptr++ = *ptr++;
+       *sptr = 0;              /* Null terminate the sender name */
+
+       /* Check for end of address marker, and skip over it */
+       if (ptr >= end || *ptr != '*') {
+               RecvErr("No second *", strip_info);
+               return;
+       }
+       ptr++;                  /* Skip the second '*' */
+
+       /* If the sender name is "&COMMAND", ignore this 'packet'       */
+       /* (This is here for backwards compatibility with old firmware) */
+       if (!strcmp(sendername, "&COMMAND")) {
+               strip_info->firmware_level = NoStructure;
+               strip_info->next_command = CompatibilityCommand;
+               return;
+       }
+
+       if (ptr + 4 > end) {
+               RecvErr("No proto key", strip_info);
+               return;
+       }
+
+       /* Get the protocol key out of the buffer */
+       key.c[0] = *ptr++;
+       key.c[1] = *ptr++;
+       key.c[2] = *ptr++;
+       key.c[3] = *ptr++;
+
+       /* If we're using checksums, verify the checksum at the end of the packet */
+       if (strip_info->firmware_level >= ChecksummedMessages) {
+               end -= 4;       /* Chop the last four bytes off the packet (they're the checksum) */
+               if (ptr > end) {
+                       RecvErr("Missing Checksum", strip_info);
+                       return;
+               }
+               if (!verify_checksum(strip_info)) {
+                       RecvErr("Bad Checksum", strip_info);
+                       return;
+               }
+       }
+
+       /*printk(KERN_INFO "%s: Got packet from \"%s\".\n", strip_info->dev->name, sendername); */
+
+       /*
+        * Fill in (pseudo) source and destination addresses in the packet.
+        * We assume that the destination address was our address (the radio does not
+        * tell us this). If the radio supplies a source address, then we use it.
+        */
+       header.dst_addr = strip_info->true_dev_addr;
+       string_to_radio_address(&header.src_addr, sendername);
+
+#ifdef EXT_COUNTERS
+       if (key.l == SIP0Key.l) {
+               strip_info->rx_rbytes += (end - ptr);
+               process_IP_packet(strip_info, &header, ptr, end);
+       } else if (key.l == ARP0Key.l) {
+               strip_info->rx_rbytes += (end - ptr);
+               process_ARP_packet(strip_info, &header, ptr, end);
+       } else if (key.l == ATR_Key.l) {
+               strip_info->rx_ebytes += (end - ptr);
+               process_AT_response(strip_info, ptr, end);
+       } else if (key.l == ACK_Key.l) {
+               strip_info->rx_ebytes += (end - ptr);
+               process_ACK(strip_info, ptr, end);
+       } else if (key.l == INF_Key.l) {
+               strip_info->rx_ebytes += (end - ptr);
+               process_Info(strip_info, ptr, end);
+       } else if (key.l == ERR_Key.l) {
+               strip_info->rx_ebytes += (end - ptr);
+               RecvErr_Message(strip_info, sendername, ptr, end - ptr);
+       } else
+               RecvErr("Unrecognized protocol key", strip_info);
+#else
+       if (key.l == SIP0Key.l)
+               process_IP_packet(strip_info, &header, ptr, end);
+       else if (key.l == ARP0Key.l)
+               process_ARP_packet(strip_info, &header, ptr, end);
+       else if (key.l == ATR_Key.l)
+               process_AT_response(strip_info, ptr, end);
+       else if (key.l == ACK_Key.l)
+               process_ACK(strip_info, ptr, end);
+       else if (key.l == INF_Key.l)
+               process_Info(strip_info, ptr, end);
+       else if (key.l == ERR_Key.l)
+               RecvErr_Message(strip_info, sendername, ptr, end - ptr);
+       else
+               RecvErr("Unrecognized protocol key", strip_info);
+#endif
+}
+
+#define TTYERROR(X) ((X) == TTY_BREAK   ? "Break"            : \
+                     (X) == TTY_FRAME   ? "Framing Error"    : \
+                     (X) == TTY_PARITY  ? "Parity Error"     : \
+                     (X) == TTY_OVERRUN ? "Hardware Overrun" : "Unknown Error")
+
+/*
+ * Handle the 'receiver data ready' interrupt.
+ * This function is called by the 'tty_io' module in the kernel when
+ * a block of STRIP data has been received, which can now be decapsulated
+ * and sent on to some IP layer for further processing.
+ */
+
+static void strip_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+                 char *fp, int count)
+{
+       struct strip *strip_info = (struct strip *) tty->disc_data;
+       const unsigned char *end = cp + count;
+
+       if (!strip_info || strip_info->magic != STRIP_MAGIC
+           || !netif_running(strip_info->dev))
+               return;
+
+       spin_lock_bh(&strip_lock);
+#if 0
+       {
+               struct timeval tv;
+               do_gettimeofday(&tv);
+               printk(KERN_INFO
+                      "**** strip_receive_buf: %3d bytes at %02d.%06d\n",
+                      count, tv.tv_sec % 100, tv.tv_usec);
+       }
+#endif
+
+#ifdef EXT_COUNTERS
+       strip_info->rx_sbytes += count;
+#endif
+
+       /* Read the characters out of the buffer */
+       while (cp < end) {
+               if (fp && *fp)
+                       printk(KERN_INFO "%s: %s on serial port\n",
+                              strip_info->dev->name, TTYERROR(*fp));
+               if (fp && *fp++ && !strip_info->discard) {      /* If there's a serial error, record it */
+                       /* If we have some characters in the buffer, discard them */
+                       strip_info->discard = strip_info->sx_count;
+                       strip_info->rx_errors++;
+               }
+
+               /* Leading control characters (CR, NL, Tab, etc.) are ignored */
+               if (strip_info->sx_count > 0 || *cp >= ' ') {
+                       if (*cp == 0x0D) {      /* If end of packet, decide what to do with it */
+                               if (strip_info->sx_count > 3000)
+                                       printk(KERN_INFO
+                                              "%s: Cut a %d byte packet (%zd bytes remaining)%s\n",
+                                              strip_info->dev->name,
+                                              strip_info->sx_count,
+                                              end - cp - 1,
+                                              strip_info->
+                                              discard ? " (discarded)" :
+                                              "");
+                               if (strip_info->sx_count >
+                                   strip_info->sx_size) {
+                                       strip_info->rx_over_errors++;
+                                       printk(KERN_INFO
+                                              "%s: sx_buff overflow (%d bytes total)\n",
+                                              strip_info->dev->name,
+                                              strip_info->sx_count);
+                               } else if (strip_info->discard)
+                                       printk(KERN_INFO
+                                              "%s: Discarding bad packet (%d/%d)\n",
+                                              strip_info->dev->name,
+                                              strip_info->discard,
+                                              strip_info->sx_count);
+                               else
+                                       process_message(strip_info);
+                               strip_info->discard = 0;
+                               strip_info->sx_count = 0;
+                       } else {
+                               /* Make sure we have space in the buffer */
+                               if (strip_info->sx_count <
+                                   strip_info->sx_size)
+                                       strip_info->sx_buff[strip_info->
+                                                           sx_count] =
+                                           *cp;
+                               strip_info->sx_count++;
+                       }
+               }
+               cp++;
+       }
+       spin_unlock_bh(&strip_lock);
+}
+
+
+/************************************************************************/
+/* General control routines                                            */
+
+static int set_mac_address(struct strip *strip_info,
+                          MetricomAddress * addr)
+{
+       /*
+        * We're using a manually specified address if the address is set
+        * to anything other than all ones. Setting the address to all ones
+        * disables manual mode and goes back to automatic address determination
+        * (tracking the true address that the radio has).
+        */
+       strip_info->manual_dev_addr =
+           memcmp(addr->c, broadcast_address.c,
+                  sizeof(broadcast_address));
+       if (strip_info->manual_dev_addr)
+               *(MetricomAddress *) strip_info->dev->dev_addr = *addr;
+       else
+               *(MetricomAddress *) strip_info->dev->dev_addr =
+                   strip_info->true_dev_addr;
+       return 0;
+}
+
+static int strip_set_mac_address(struct net_device *dev, void *addr)
+{
+       struct strip *strip_info = netdev_priv(dev);
+       struct sockaddr *sa = addr;
+       printk(KERN_INFO "%s: strip_set_dev_mac_address called\n", dev->name);
+       set_mac_address(strip_info, (MetricomAddress *) sa->sa_data);
+       return 0;
+}
+
+static struct net_device_stats *strip_get_stats(struct net_device *dev)
+{
+       struct strip *strip_info = netdev_priv(dev);
+       static struct net_device_stats stats;
+
+       memset(&stats, 0, sizeof(struct net_device_stats));
+
+       stats.rx_packets = strip_info->rx_packets;
+       stats.tx_packets = strip_info->tx_packets;
+       stats.rx_dropped = strip_info->rx_dropped;
+       stats.tx_dropped = strip_info->tx_dropped;
+       stats.tx_errors = strip_info->tx_errors;
+       stats.rx_errors = strip_info->rx_errors;
+       stats.rx_over_errors = strip_info->rx_over_errors;
+       return (&stats);
+}
+
+
+/************************************************************************/
+/* Opening and closing                                                 */
+
+/*
+ * Here's the order things happen:
+ * When the user runs "slattach -p strip ..."
+ *  1. The TTY module calls strip_open;;
+ *  2. strip_open calls strip_alloc
+ *  3.                  strip_alloc calls register_netdev
+ *  4.                  register_netdev calls strip_dev_init
+ *  5. then strip_open finishes setting up the strip_info
+ *
+ * When the user runs "ifconfig st<x> up address netmask ..."
+ *  6. strip_open_low gets called
+ *
+ * When the user runs "ifconfig st<x> down"
+ *  7. strip_close_low gets called
+ *
+ * When the user kills the slattach process
+ *  8. strip_close gets called
+ *  9. strip_close calls dev_close
+ * 10. if the device is still up, then dev_close calls strip_close_low
+ * 11. strip_close calls strip_free
+ */
+
+/* Open the low-level part of the STRIP channel. Easy! */
+
+static int strip_open_low(struct net_device *dev)
+{
+       struct strip *strip_info = netdev_priv(dev);
+
+       if (strip_info->tty == NULL)
+               return (-ENODEV);
+
+       if (!allocate_buffers(strip_info, dev->mtu))
+               return (-ENOMEM);
+
+       strip_info->sx_count = 0;
+       strip_info->tx_left = 0;
+
+       strip_info->discard = 0;
+       strip_info->working = FALSE;
+       strip_info->firmware_level = NoStructure;
+       strip_info->next_command = CompatibilityCommand;
+       strip_info->user_baud = tty_get_baud_rate(strip_info->tty);
+
+       printk(KERN_INFO "%s: Initializing Radio.\n",
+              strip_info->dev->name);
+       ResetRadio(strip_info);
+       strip_info->idle_timer.expires = jiffies + 1 * HZ;
+       add_timer(&strip_info->idle_timer);
+       netif_wake_queue(dev);
+       return (0);
+}
+
+
+/*
+ * Close the low-level part of the STRIP channel. Easy!
+ */
+
+static int strip_close_low(struct net_device *dev)
+{
+       struct strip *strip_info = netdev_priv(dev);
+
+       if (strip_info->tty == NULL)
+               return -EBUSY;
+       strip_info->tty->flags &= ~(1 << TTY_DO_WRITE_WAKEUP);
+
+       netif_stop_queue(dev);
+
+       /*
+        * Free all STRIP frame buffers.
+        */
+       kfree(strip_info->rx_buff);
+       strip_info->rx_buff = NULL;
+       kfree(strip_info->sx_buff);
+       strip_info->sx_buff = NULL;
+       kfree(strip_info->tx_buff);
+       strip_info->tx_buff = NULL;
+
+       del_timer(&strip_info->idle_timer);
+       return 0;
+}
+
+static const struct header_ops strip_header_ops = {
+       .create = strip_header,
+       .rebuild = strip_rebuild_header,
+};
+
+/*
+ * This routine is called by DDI when the
+ * (dynamically assigned) device is registered
+ */
+
+static void strip_dev_setup(struct net_device *dev)
+{
+       /*
+        * Finish setting up the DEVICE info.
+        */
+
+       dev->trans_start = 0;
+       dev->last_rx = 0;
+       dev->tx_queue_len = 30; /* Drop after 30 frames queued */
+
+       dev->flags = 0;
+       dev->mtu = DEFAULT_STRIP_MTU;
+       dev->type = ARPHRD_METRICOM;    /* dtang */
+       dev->hard_header_len = sizeof(STRIP_Header);
+       /*
+        *  dev->priv             Already holds a pointer to our struct strip
+        */
+
+       *(MetricomAddress *) & dev->broadcast = broadcast_address;
+       dev->dev_addr[0] = 0;
+       dev->addr_len = sizeof(MetricomAddress);
+
+       /*
+        * Pointers to interface service routines.
+        */
+
+       dev->open = strip_open_low;
+       dev->stop = strip_close_low;
+       dev->hard_start_xmit = strip_xmit;
+       dev->header_ops = &strip_header_ops;
+
+       dev->set_mac_address = strip_set_mac_address;
+       dev->get_stats = strip_get_stats;
+       dev->change_mtu = strip_change_mtu;
+}
+
+/*
+ * Free a STRIP channel.
+ */
+
+static void strip_free(struct strip *strip_info)
+{
+       spin_lock_bh(&strip_lock);
+       list_del_rcu(&strip_info->list);
+       spin_unlock_bh(&strip_lock);
+
+       strip_info->magic = 0;
+
+       free_netdev(strip_info->dev);
+}
+
+
+/*
+ * Allocate a new free STRIP channel
+ */
+static struct strip *strip_alloc(void)
+{
+       struct list_head *n;
+       struct net_device *dev;
+       struct strip *strip_info;
+
+       dev = alloc_netdev(sizeof(struct strip), "st%d",
+                          strip_dev_setup);
+
+       if (!dev)
+               return NULL;    /* If no more memory, return */
+
+
+       strip_info = netdev_priv(dev);
+       strip_info->dev = dev;
+
+       strip_info->magic = STRIP_MAGIC;
+       strip_info->tty = NULL;
+
+       strip_info->gratuitous_arp = jiffies + LongTime;
+       strip_info->arp_interval = 0;
+       init_timer(&strip_info->idle_timer);
+       strip_info->idle_timer.data = (long) dev;
+       strip_info->idle_timer.function = strip_IdleTask;
+
+
+       spin_lock_bh(&strip_lock);
+ rescan:
+       /*
+        * Search the list to find where to put our new entry
+        * (and in the process decide what channel number it is
+        * going to be)
+        */
+       list_for_each(n, &strip_list) {
+               struct strip *s = hlist_entry(n, struct strip, list);
+
+               if (s->dev->base_addr == dev->base_addr) {
+                       ++dev->base_addr;
+                       goto rescan;
+               }
+       }
+
+       sprintf(dev->name, "st%ld", dev->base_addr);
+
+       list_add_tail_rcu(&strip_info->list, &strip_list);
+       spin_unlock_bh(&strip_lock);
+
+       return strip_info;
+}
+
+/*
+ * Open the high-level part of the STRIP channel.
+ * This function is called by the TTY module when the
+ * STRIP line discipline is called for.  Because we are
+ * sure the tty line exists, we only have to link it to
+ * a free STRIP channel...
+ */
+
+static int strip_open(struct tty_struct *tty)
+{
+       struct strip *strip_info = (struct strip *) tty->disc_data;
+
+       /*
+        * First make sure we're not already connected.
+        */
+
+       if (strip_info && strip_info->magic == STRIP_MAGIC)
+               return -EEXIST;
+
+       /*
+        * We need a write method.
+        */
+
+       if (tty->ops->write == NULL || tty->ops->set_termios == NULL)
+               return -EOPNOTSUPP;
+
+       /*
+        * OK.  Find a free STRIP channel to use.
+        */
+       if ((strip_info = strip_alloc()) == NULL)
+               return -ENFILE;
+
+       /*
+        * Register our newly created device so it can be ifconfig'd
+        * strip_dev_init() will be called as a side-effect
+        */
+
+       if (register_netdev(strip_info->dev) != 0) {
+               printk(KERN_ERR "strip: register_netdev() failed.\n");
+               strip_free(strip_info);
+               return -ENFILE;
+       }
+
+       strip_info->tty = tty;
+       tty->disc_data = strip_info;
+       tty->receive_room = 65536;
+
+       tty_driver_flush_buffer(tty);
+
+       /*
+        * Restore default settings
+        */
+
+       strip_info->dev->type = ARPHRD_METRICOM;        /* dtang */
+
+       /*
+        * Set tty options
+        */
+
+       tty->termios->c_iflag |= IGNBRK | IGNPAR;       /* Ignore breaks and parity errors. */
+       tty->termios->c_cflag |= CLOCAL;        /* Ignore modem control signals. */
+       tty->termios->c_cflag &= ~HUPCL;        /* Don't close on hup */
+
+       printk(KERN_INFO "STRIP: device \"%s\" activated\n",
+              strip_info->dev->name);
+
+       /*
+        * Done.  We have linked the TTY line to a channel.
+        */
+       return (strip_info->dev->base_addr);
+}
+
+/*
+ * Close down a STRIP channel.
+ * This means flushing out any pending queues, and then restoring the
+ * TTY line discipline to what it was before it got hooked to STRIP
+ * (which usually is TTY again).
+ */
+
+static void strip_close(struct tty_struct *tty)
+{
+       struct strip *strip_info = (struct strip *) tty->disc_data;
+
+       /*
+        * First make sure we're connected.
+        */
+
+       if (!strip_info || strip_info->magic != STRIP_MAGIC)
+               return;
+
+       unregister_netdev(strip_info->dev);
+
+       tty->disc_data = NULL;
+       strip_info->tty = NULL;
+       printk(KERN_INFO "STRIP: device \"%s\" closed down\n",
+              strip_info->dev->name);
+       strip_free(strip_info);
+       tty->disc_data = NULL;
+}
+
+
+/************************************************************************/
+/* Perform I/O control calls on an active STRIP channel.               */
+
+static int strip_ioctl(struct tty_struct *tty, struct file *file,
+                      unsigned int cmd, unsigned long arg)
+{
+       struct strip *strip_info = (struct strip *) tty->disc_data;
+
+       /*
+        * First make sure we're connected.
+        */
+
+       if (!strip_info || strip_info->magic != STRIP_MAGIC)
+               return -EINVAL;
+
+       switch (cmd) {
+       case SIOCGIFNAME:
+               if(copy_to_user((void __user *) arg, strip_info->dev->name, strlen(strip_info->dev->name) + 1))
+                       return -EFAULT;
+               break;
+       case SIOCSIFHWADDR:
+       {
+               MetricomAddress addr;
+               //printk(KERN_INFO "%s: SIOCSIFHWADDR\n", strip_info->dev->name);
+               if(copy_from_user(&addr, (void __user *) arg, sizeof(MetricomAddress)))
+                       return -EFAULT;
+               return set_mac_address(strip_info, &addr);
+       }
+       default:
+               return tty_mode_ioctl(tty, file, cmd, arg);
+               break;
+       }
+       return 0;
+}
+
+
+/************************************************************************/
+/* Initialization                                                      */
+
+static struct tty_ldisc strip_ldisc = {
+       .magic = TTY_LDISC_MAGIC,
+       .name = "strip",
+       .owner = THIS_MODULE,
+       .open = strip_open,
+       .close = strip_close,
+       .ioctl = strip_ioctl,
+       .receive_buf = strip_receive_buf,
+       .write_wakeup = strip_write_some_more,
+};
+
+/*
+ * Initialize the STRIP driver.
+ * This routine is called at boot time, to bootstrap the multi-channel
+ * STRIP driver
+ */
+
+static char signon[] __initdata =
+    KERN_INFO "STRIP: Version %s (unlimited channels)\n";
+
+static int __init strip_init_driver(void)
+{
+       int status;
+
+       printk(signon, StripVersion);
+
+       
+       /*
+        * Fill in our line protocol discipline, and register it
+        */
+       if ((status = tty_register_ldisc(N_STRIP, &strip_ldisc)))
+               printk(KERN_ERR "STRIP: can't register line discipline (err = %d)\n",
+                      status);
+
+       /*
+        * Register the status file with /proc
+        */
+       proc_net_fops_create(&init_net, "strip", S_IFREG | S_IRUGO, &strip_seq_fops);
+
+       return status;
+}
+
+module_init(strip_init_driver);
+
+static const char signoff[] __exitdata =
+    KERN_INFO "STRIP: Module Unloaded\n";
+
+static void __exit strip_exit_driver(void)
+{
+       int i;
+       struct list_head *p,*n;
+
+       /* module ref count rules assure that all entries are unregistered */
+       list_for_each_safe(p, n, &strip_list) {
+               struct strip *s = list_entry(p, struct strip, list);
+               strip_free(s);
+       }
+
+       /* Unregister with the /proc/net file here. */
+       proc_net_remove(&init_net, "strip");
+
+       if ((i = tty_unregister_ldisc(N_STRIP)))
+               printk(KERN_ERR "STRIP: can't unregister line discipline (err = %d)\n", i);
+
+       printk(signoff);
+}
+
+module_exit(strip_exit_driver);
+
+MODULE_AUTHOR("Stuart Cheshire <cheshire@cs.stanford.edu>");
+MODULE_DESCRIPTION("Starmode Radio IP (STRIP) Device Driver");
+MODULE_LICENSE("Dual BSD/GPL");
+
+MODULE_SUPPORTED_DEVICE("Starmode Radio IP (STRIP) modem");