strip.c

linux-2.6.15.6

 * 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 list_head *l;
	int i = 0;

	list_for_each_rcu(l, &strip_list) {
		if (pos == i)
			return list_entry(l, struct strip, list);
		++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 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 > B38400) {
		/*
		 * 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 == get_baud(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, B19200);
			if (strip_info->user_baud == B57600)
				s = baudstring[0];
			else if (strip_info->user_baud == B115200)
				s = baudstring[1];
			else
				s = baudstring[1];	/* For now */
		} else
			set_baud(tty, strip_info->user_baud);
	}

	tty->driver->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;