/*
*
* Copyright 1999 Digi International (www.digi.com)
* James Puzzo <jamesp at digi dot com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
*/
/*
*
* Filename:
*
* dgrp_net_ops.c
*
* Description:
*
* Handle the file operations required for the "network" devices.
* Includes those functions required to register the "net" devices
* in "/proc".
*
* Author:
*
* James A. Puzzo
*
*/
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/device.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/spinlock.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/ratelimit.h>
#include <asm/unaligned.h>
#define MYFLIPLEN TBUF_MAX
#include "dgrp_common.h"
#define TTY_FLIPBUF_SIZE 512
#define DEVICE_NAME_SIZE 50
/*
* Generic helper function declarations
*/
static void parity_scan(struct ch_struct *ch, unsigned char *cbuf,
unsigned char *fbuf, int *len);
/*
* File operation declarations
*/
static int dgrp_net_open(struct inode *, struct file *);
static int dgrp_net_release(struct inode *, struct file *);
static ssize_t dgrp_net_read(struct file *, char __user *, size_t, loff_t *);
static ssize_t dgrp_net_write(struct file *, const char __user *, size_t,
loff_t *);
static long dgrp_net_ioctl(struct file *file, unsigned int cmd,
unsigned long arg);
static unsigned int dgrp_net_select(struct file *file,
struct poll_table_struct *table);
const struct file_operations dgrp_net_ops = {
.owner = THIS_MODULE,
.read = dgrp_net_read,
.write = dgrp_net_write,
.poll = dgrp_net_select,
.unlocked_ioctl = dgrp_net_ioctl,
.open = dgrp_net_open,
.release = dgrp_net_release,
};
/**
* dgrp_dump() -- prints memory for debugging purposes.
* @mem: Memory location which should be printed to the console
* @len: Number of bytes to be dumped
*/
static void dgrp_dump(u8 *mem, int len)
{
int i;
pr_debug("dgrp dump length = %d, data = ", len);
for (i = 0; i < len; ++i)
pr_debug("%.2x ", mem[i]);
pr_debug("\n");
}
/**
* dgrp_read_data_block() -- Read a data block
* @ch: struct ch_struct *
* @flipbuf: u8 *
* @flipbuf_size: size of flipbuf
*/
static void dgrp_read_data_block(struct ch_struct *ch, u8 *flipbuf,
int flipbuf_size)
{
int t;
int n;
if (flipbuf_size <= 0)
return;
t = RBUF_MAX - ch->ch_rout;
n = flipbuf_size;
if (n >= t) {
memcpy(flipbuf, ch->ch_rbuf + ch->ch_rout, t);
flipbuf += t;
n -= t;
ch->ch_rout = 0;
}
memcpy(flipbuf, ch->ch_rbuf + ch->ch_rout, n);
flipbuf += n;
ch->ch_rout += n;
}
/**
* dgrp_input() -- send data to the line disipline
* @ch: pointer to channel struct
*
* Copys the rbuf to the flipbuf and sends to line discipline.
* Sends input buffer data to the line discipline.
*
*/
static void dgrp_input(struct ch_struct *ch)
{
struct nd_struct *nd;
struct tty_struct *tty;
int data_len;
int len;
int tty_count;
ulong lock_flags;
u8 *myflipbuf;
u8 *myflipflagbuf;
if (!ch)
return;
nd = ch->ch_nd;
if (!nd)
return;
spin_lock_irqsave(&nd->nd_lock, lock_flags);
myflipbuf = nd->nd_inputbuf;
myflipflagbuf = nd->nd_inputflagbuf;
if (!ch->ch_open_count) {
ch->ch_rout = ch->ch_rin;
goto out;
}
if (ch->ch_tun.un_flag & UN_CLOSING) {
ch->ch_rout = ch->ch_rin;
goto out;
}
tty = (ch->ch_tun).un_tty;
if (!tty || tty->magic != TTY_MAGIC) {
ch->ch_rout = ch->ch_rin;
goto out;
}
tty_count = tty->count;
if (!tty_count) {
ch->ch_rout = ch->ch_rin;
goto out;
}
if (tty->closing || test_bit(TTY_CLOSING, &tty->flags)) {
ch->ch_rout = ch->ch_rin;
goto out;
}
spin_unlock_irqrestore(&nd->nd_lock, lock_flags);
/* data_len should be the number of chars that we read in */
data_len = (ch->ch_rin - ch->ch_rout) & RBUF_MASK;
/* len is the amount of data we are going to transfer here */
len = tty_buffer_request_room(&ch->port, data_len);
/* Check DPA flow control */
if ((nd->nd_dpa_debug) &&
(nd->nd_dpa_flag & DPA_WAIT_SPACE) &&
(nd->nd_dpa_port == MINOR(tty_devnum(ch->ch_tun.un_tty))))
len = 0;
if ((len) && !(ch->ch_flag & CH_RXSTOP)) {
dgrp_read_data_block(ch, myflipbuf, len);
if (I_PARMRK(tty) || I_BRKINT(tty) || I_INPCK(tty))
parity_scan(ch, myflipbuf, myflipflagbuf, &len);
else
memset(myflipflagbuf, TTY_NORMAL, len);
if ((nd->nd_dpa_debug) &&
(nd->nd_dpa_port == PORT_NUM(MINOR(tty_devnum(tty)))))
dgrp_dpa_data(nd, 1, myflipbuf, len);
tty_insert_flip_string_flags(&ch->port, myflipbuf,
myflipflagbuf, len);
tty_flip_buffer_push(&ch->port);
ch->ch_rxcount += len;
}
/*
* Wake up any sleepers (maybe dgrp close) that might be waiting
* for a channel flag state change.
*/
wake_up_interruptible(&ch->ch_flag_wait);
return;
out:
spin_unlock_irqrestore(&nd->nd_lock, lock_flags);
}
/*
* parity_scan
*
* Loop to inspect each single character or 0xFF escape.
*
* if PARMRK & ~DOSMODE:
* 0xFF 0xFF Normal 0xFF character, escaped
* to eliminate confusion.
* 0xFF 0x00 0x00 Break
* 0xFF 0x00 CC Error character CC.
* CC Normal character CC.
*
* if PARMRK & DOSMODE:
* 0xFF 0x18 0x00 Break
* 0xFF 0x08 0x00 Framing Error
* 0xFF 0x04 0x00 Parity error
* 0xFF 0x0C 0x00 Both Framing and Parity error
*
* TODO: do we need to do the XMODEM, XOFF, XON, XANY processing??
* as per protocol
*/
static void parity_scan(struct ch_struct *ch, unsigned char *cbuf,
unsigned char *fbuf, int *len)
{
int l = *len;
int count = 0;
int DOS = ((ch->ch_iflag & IF_DOSMODE) == 0 ? 0 : 1);
unsigned char *cout; /* character buffer */
unsigned char *fout; /* flag buffer */
unsigned char *in;
unsigned char c;
in = cbuf;
cout = cbuf;
fout = fbuf;
while (l--) {
c = *in;
in++;
switch (ch->ch_pscan_state) {
default:
/* reset to sanity and fall through */
ch->ch_pscan_state = 0;
case 0:
/* No FF seen yet */
if (c == 0xff) /* delete this character from stream */
ch->ch_pscan_state = 1;
else {
*cout++ = c;
*fout++ = TTY_NORMAL;
count += 1;
}
break;
case 1:
/* first FF seen */
if (c == 0xff) {
/* doubled ff, transform to single ff */
*cout++ = c;
*fout++ = TTY_NORMAL;
count += 1;
ch->ch_pscan_state = 0;
} else {
/* save value examination in next state */
ch->ch_pscan_savechar = c;
ch->ch_pscan_state = 2;
}
break;
case 2:
/* third character of ff sequence */
*cout++ = c;
if (DOS) {
if (ch->ch_pscan_savechar & 0x10)
*fout++ = TTY_BREAK;
else if (ch->ch_pscan_savechar & 0x08)
*fout++ = TTY_FRAME;
else
/*
* either marked as a parity error,
* indeterminate, or not in DOSMODE
* call it a parity error
*/
*fout++ = TTY_PARITY;
} else {
/* case FF XX ?? where XX is not 00 */
if (ch->ch_pscan_savechar & 0xff) {
/* this should not happen */
pr_info("%s: parity_scan: error unexpected byte\n",
__func__);
*fout++ = TTY_PARITY;
}
/* case FF 00 XX where XX is not 00 */
else if (c == 0xff)
*fout++ = TTY_PARITY;
/* case FF 00 00 */
else
*fout++ = TTY_BREAK;
}
count += 1;
ch->ch_pscan_state = 0;
}
}
*len = count;
}
/**
* dgrp_net_idle() -- Idle the network connection
* @nd: pointer to node structure to idle
*/
static void dgrp_net_idle(struct nd_struct *nd)
{
struct ch_struct *ch;
int i;
nd->nd_tx_work = 1;
nd->nd_state = NS_IDLE;
nd->nd_flag = 0;
for (i = nd->nd_seq_out; ; i = (i + 1) & SEQ_MASK) {
if (!nd->nd_seq_wait[i]) {
nd->nd_seq_wait[i] = 0;
wake_up_interruptible(&nd->nd_seq_wque[i]);
}
if (i == nd->nd_seq_in)
break;
}
nd->nd_seq_out = nd->nd_seq_in;
nd->nd_unack = 0;
nd->nd_remain = 0;
nd->nd_tx_module = 0x10;
nd->nd_rx_module = 0x00;
for (i = 0, ch = nd->nd_chan; i < CHAN_MAX; i++, ch++) {
ch->ch_state = CS_IDLE;
ch->ch_otype = 0;
ch->ch_otype_waiting = 0;
}
}
/*
* Increase the number of channels, waking up any
* threads that might be waiting for the channels
* to appear.
*/
static void increase_channel_count(struct nd_struct *nd, int n)
{
struct ch_struct *ch;
struct device *classp;
char name[DEVICE_NAME_SIZE];
int ret;
u8 *buf;
int i;
for (i = nd->nd_chan_count; i < n; ++i) {
ch = nd->nd_chan + i;
/* FIXME: return a useful error instead! */
buf = kmalloc(TBUF_MAX, GFP_KERNEL);
if (!buf)
return;
if (ch->ch_tbuf)
pr_info_ratelimited("%s - ch_tbuf was not NULL\n",
__func__);
ch->ch_tbuf = buf;
buf = kmalloc(RBUF_MAX, GFP_KERNEL);
if (!buf)
return;
if (ch->ch_rbuf)
pr_info("%s - ch_rbuf was not NULL\n",
__func__);
ch->ch_rbuf = buf;
classp = tty_port_register_device(&ch->port,
nd->nd_serial_ttdriver, i,
NULL);
ch->ch_tun.un_sysfs = classp;
snprintf(name, DEVICE_NAME_SIZE, "tty_%d", i);
dgrp_create_tty_sysfs(&ch->ch_tun, classp);
ret = sysfs_create_link(&nd->nd_class_dev->kobj,
&classp->kobj, name);
/* NOTE: We don't support "cu" devices anymore,
* so you will notice we don't register them
* here anymore. */
if (dgrp_register_prdevices) {
classp = tty_register_device(nd->nd_xprint_ttdriver,
i, NULL);
ch->ch_pun.un_sysfs = classp;
snprintf(name, DEVICE_NAME_SIZE, "pr_%d", i);
dgrp_create_tty_sysfs(&ch->ch_pun, classp);
ret = sysfs_create_link(&nd->nd_class_dev->kobj,
&classp->kobj, name);
}
nd->nd_chan_count = i + 1;
wake_up_interruptible(&ch->ch_flag_wait);
}
}
/*
* Decrease the number of channels, and wake up any threads that might
* be waiting on the channels that vanished.
*/
static void decrease_channel_count(struct nd_struct *nd, int n)
{
struct ch_struct *ch;
char name[DEVICE_NAME_SIZE];
int i;
for (i = nd->nd_chan_count - 1; i >= n; --i) {
ch = nd->nd_chan + i;
/*
* Make any open ports inoperative.
*/
ch->ch_state = CS_IDLE;
ch->ch_otype = 0;
ch->ch_otype_waiting = 0;
/*
* Only "HANGUP" if we care about carrier
* transitions and we are already open.
*/
if (ch->ch_open_count != 0) {
ch->ch_flag |= CH_HANGUP;
dgrp_carrier(ch);
}
/*
* Unlike the CH_HANGUP flag above, use another
* flag to indicate to the RealPort state machine
* that this port has disappeared.
*/
if (ch->ch_open_count != 0)
ch->ch_flag |= CH_PORT_GONE;
wake_up_interruptible(&ch->ch_flag_wait);
nd->nd_chan_count = i;
kfree(ch->ch_tbuf);
ch->ch_tbuf = NULL;
kfree(ch->ch_rbuf);
ch->ch_rbuf = NULL;
nd->nd_chan_count = i;
dgrp_remove_tty_sysfs(ch->ch_tun.un_sysfs);
snprintf(name, DEVICE_NAME_SIZE, "tty_%d", i);
sysfs_remove_link(&nd->nd_class_dev->kobj, name);
tty_unregister_device(nd->nd_serial_ttdriver, i);
/*
* NOTE: We don't support "cu" devices anymore, so don't
* unregister them here anymore.
*/
if (dgrp_register_prdevices) {
dgrp_remove_tty_sysfs(ch->ch_pun.un_sysfs);
snprintf(name, DEVICE_NAME_SIZE, "pr_%d", i);
sysfs_remove_link(&nd->nd_class_dev->kobj, name);
tty_unregister_device(nd->nd_xprint_ttdriver, i);
}
}
}
/**
* dgrp_chan_count() -- Adjust the node channel count.
* @nd: pointer to a node structure
* @n: new value for channel count
*
* Adjusts the node channel count. If new ports have appeared, it tries
* to signal those processes that might have been waiting for ports to
* appear. If ports have disappeared it tries to signal those processes
* that might be hung waiting for a response for the now non-existant port.
*/
static void dgrp_chan_count(struct nd_struct *nd, int n)
{
if (n == nd->nd_chan_count)
return;
if (n > nd->nd_chan_count)
increase_channel_count(nd, n);
if (n < nd->nd_chan_count)
decrease_channel_count(nd, n);
}
/**
* dgrp_monitor() -- send data to the device monitor queue
* @nd: pointer to a node structure
* @buf: data to copy to the monitoring buffer
* @len: number of bytes to transfer to the buffer
*
* Called by the net device routines to send data to the device
* monitor queue. If the device monitor buffer is too full to
* accept the data, it waits until the buffer is ready.
*/
static void dgrp_monitor(struct nd_struct *nd, u8 *buf, int len)
{
int n;
int r;
int rtn;
/*
* Grab monitor lock.
*/
down(&nd->nd_mon_semaphore);
/*
* Loop while data remains.
*/
while ((len > 0) && (nd->nd_mon_buf)) {
/*
* Determine the amount of available space left in the
* buffer. If there's none, wait until some appears.
*/
n = (nd->nd_mon_out - nd->nd_mon_in - 1) & MON_MASK;
if (!n) {
nd->nd_mon_flag |= MON_WAIT_SPACE;
up(&nd->nd_mon_semaphore);
/*
* Go to sleep waiting until the condition becomes true.
*/
rtn = wait_event_interruptible(nd->nd_mon_wqueue,
((nd->nd_mon_flag & MON_WAIT_SPACE) == 0));
/* FIXME: really ignore rtn? */
/*
* We can't exit here if we receive a signal, since
* to do so would trash the debug stream.
*/
down(&nd->nd_mon_semaphore);
continue;
}
/*
* Copy as much data as will fit.
*/
if (n > len)
n = len;
r = MON_MAX - nd->nd_mon_in;
if (r <= n) {
memcpy(nd->nd_mon_buf + nd->nd_mon_in, buf, r);
n -= r;
nd->nd_mon_in = 0;
buf += r;
len -= r;
}
memcpy(nd->nd_mon_buf + nd->nd_mon_in, buf, n);
nd->nd_mon_in += n;
buf += n;
len -= n;
if (nd->nd_mon_in >= MON_MAX)
pr_info_ratelimited("%s - nd_mon_in (%i) >= MON_MAX\n",
__func__, nd->nd_mon_in);
/*
* Wakeup any thread waiting for data
*/
if (nd->nd_mon_flag & MON_WAIT_DATA) {
nd->nd_mon_flag &= ~MON_WAIT_DATA;
wake_up_interruptible(&nd->nd_mon_wqueue);
}
}
/*
* Release the monitor lock.
*/
up(&nd->nd_mon_semaphore);
}
/**
* dgrp_encode_time() -- Encodes rpdump time into a 4-byte quantity.
* @nd: pointer to a node structure
* @buf: destination buffer
*
* Encodes "rpdump" time into a 4-byte quantity. Time is measured since
* open.
*/
static void dgrp_encode_time(struct nd_struct *nd, u8 *buf)
{
ulong t;
/*
* Convert time in HZ since open to time in milliseconds
* since open.
*/
t = jiffies - nd->nd_mon_lbolt;
t = 1000 * (t / HZ) + 1000 * (t % HZ) / HZ;
put_unaligned_be32((uint)(t & 0xffffffff), buf);
}
/**
* dgrp_monitor_message() -- Builds a rpdump style message.
* @nd: pointer to a node structure
* @message: destination buffer
*/
static void dgrp_monitor_message(struct nd_struct *nd, char *message)
{
u8 header[7];
int n;
header[0] = RPDUMP_MESSAGE;
dgrp_encode_time(nd, header + 1);
n = strlen(message);
put_unaligned_be16(n, header + 5);
dgrp_monitor(nd, header, sizeof(header));
dgrp_monitor(nd, (u8 *) message, n);
}
/**
* dgrp_monitor_reset() -- Note a reset in the monitoring buffer.
* @nd: pointer to a node structure
*/
static void dgrp_monitor_reset(struct nd_struct *nd)
{
u8 header[5];
header[0] = RPDUMP_RESET;
dgrp_encode_time(nd, header + 1);
dgrp_monitor(nd, header, sizeof(header));
}
/**
* dgrp_monitor_data() -- builds a monitor data packet
* @nd: pointer to a node structure
* @type: type of message to be logged
* @buf: data to be logged
* @size: number of bytes in the buffer
*/
static void dgrp_monitor_data(struct nd_struct *nd, u8 type, u8 *buf, int size)
{
u8 header[7];
header[0] = type;
dgrp_encode_time(nd, header + 1);
put_unaligned_be16(size, header + 5);
dgrp_monitor(nd, header, sizeof(header));
dgrp_monitor(nd, buf, size);
}
static int alloc_nd_buffers(struct nd_struct *nd)
{
nd->nd_iobuf = NULL;
nd->nd_writebuf = NULL;
nd->nd_inputbuf = NULL;
nd->nd_inputflagbuf = NULL;
/*
* Allocate the network read/write buffer.
*/
nd->nd_iobuf = kzalloc(UIO_MAX + 10, GFP_KERNEL);
if (!nd->nd_iobuf)
goto out_err;
/*
* Allocate a buffer for doing the copy from user space to
* kernel space in the write routines.
*/
nd->nd_writebuf = kzalloc(WRITEBUFLEN, GFP_KERNEL);
if (!nd->nd_writebuf)
goto out_err;
/*
* Allocate a buffer for doing the copy from kernel space to
* tty buffer space in the read routines.
*/
nd->nd_inputbuf = kzalloc(MYFLIPLEN, GFP_KERNEL);
if (!nd->nd_inputbuf)
goto out_err;
/*
* Allocate a buffer for doing the copy from kernel space to
* tty buffer space in the read routines.
*/
nd->nd_inputflagbuf = kzalloc(MYFLIPLEN, GFP_KERNEL);
if (!nd->nd_inputflagbuf)
goto out_err;
return 0;
out_err:
kfree(nd->nd_iobuf);
kfree(nd->nd_writebuf);
kfree(nd->nd_inputbuf);
kfree(nd->nd_inputflagbuf);
return -ENOMEM;
}
/*
* dgrp_net_open() -- Open the NET device for a particular PortServer
*/
static int dgrp_net_open(struct inode *inode, struct file *file)
{
struct nd_struct *nd;
ulong lock_flags;
int rtn;
rtn = try_module_get(THIS_MODULE);
if (!rtn)
return -EAGAIN;
if (!capable(CAP_SYS_ADMIN)) {
rtn = -EPERM;
goto done;
}
/*
* Make sure that the "private_data" field hasn't already been used.
*/
if (file->private_data) {
rtn = -EINVAL;
goto done;
}
/*
* Get the node pointer, and fail if it doesn't exist.
*/
nd = PDE_DATA(inode);
if (!nd) {
rtn = -ENXIO;
goto done;
}
file->private_data = (void *) nd;
/*
* Grab the NET lock.
*/
down(&nd->nd_net_semaphore);
if (nd->nd_state != NS_CLOSED) {
rtn = -EBUSY;
goto unlock;
}
/*
* Initialize the link speed parameters.
*/
nd->nd_link.lk_fast_rate = UIO_MAX;
nd->nd_link.lk_slow_rate = UIO_MAX;
nd->nd_link.lk_fast_delay = 1000;
nd->nd_link.lk_slow_delay = 1000;
nd->nd_link.lk_header_size = 46;
rtn = alloc_nd_buffers(nd);
if (rtn)
goto unlock;
/*
* The port is now open, so move it to the IDLE state
*/
dgrp_net_idle(nd);
nd->nd_tx_time = jiffies;
/*
* If the polling routing is not running, start it running here
*/
spin_lock_irqsave(&dgrp_poll_data.poll_lock, lock_flags);
if (!dgrp_poll_data.node_active_count) {
dgrp_poll_data.node_active_count = 2;
dgrp_poll_data.timer.expires = jiffies +
dgrp_poll_tick * HZ / 1000;
add_timer(&dgrp_poll_data.timer);
}
spin_unlock_irqrestore(&dgrp_poll_data.poll_lock, lock_flags);
dgrp_monitor_message(nd, "Net Open");
unlock:
/*
* Release the NET lock.
*/
up(&nd->nd_net_semaphore);
done:
if (rtn)
module_put(THIS_MODULE);
return rtn;
}
/* dgrp_net_release() -- close the NET device for a particular PortServer */
static int dgrp_net_release(struct inode *inode, struct file *file)
{
struct nd_struct *nd;
ulong lock_flags;
nd = (struct nd_struct *)(file->private_data);
if (!nd)
goto done;
/* TODO : historical locking placeholder */
/*
* In the HPUX version of the RealPort driver (which served as a basis
* for this driver) this locking code was used. Saved if ever we need
* to review the locking under Linux.
*/
/* spinlock(&nd->nd_lock); */
/*
* Grab the NET lock.
*/
down(&nd->nd_net_semaphore);
/*
* Before "closing" the internal connection, make sure all
* ports are "idle".
*/
dgrp_net_idle(nd);
nd->nd_state = NS_CLOSED;
nd->nd_flag = 0;
/*
* TODO ... must the wait queue be reset on close?
* should any pending waiters be reset?
* Let's decide to assert that the waitq is empty... and see
* how soon we break.
*/
if (waitqueue_active(&nd->nd_tx_waitq))
pr_info("%s - expected waitqueue_active to be false\n",
__func__);
nd->nd_send = 0;
kfree(nd->nd_iobuf);
nd->nd_iobuf = NULL;
/* TODO : historical locking placeholder */
/*
* In the HPUX version of the RealPort driver (which served as a basis
* for this driver) this locking code was used. Saved if ever we need
* to review the locking under Linux.
*/
/* spinunlock( &nd->nd_lock ); */
kfree(nd->nd_writebuf);
nd->nd_writebuf = NULL;
kfree(nd->nd_inputbuf);
nd->nd_inputbuf = NULL;
kfree(nd->nd_inputflagbuf);
nd->nd_inputflagbuf = NULL;
/* TODO : historical locking placeholder */
/*
* In the HPUX version of the RealPort driver (which served as a basis
* for this driver) this locking code was used. Saved if ever we need
* to review the locking under Linux.
*/
/* spinlock(&nd->nd_lock); */
/*
* Set the active port count to zero.
*/
dgrp_chan_count(nd, 0);
/* TODO : historical locking placeholder */
/*
* In the HPUX version of the RealPort driver (which served as a basis
* for this driver) this locking code was used. Saved if ever we need
* to review the locking under Linux.
*/
/* spinunlock(&nd->nd_lock); */
/*
* Release the NET lock.
*/
up(&nd->nd_net_semaphore);
/*
* Cause the poller to stop scheduling itself if this is
* the last active node.
*/
spin_lock_irqsave(&dgrp_poll_data.poll_lock, lock_flags);
if (dgrp_poll_data.node_active_count == 2) {
del_timer(&dgrp_poll_data.timer);
dgrp_poll_data.node_active_count = 0;
}
spin_unlock_irqrestore(&dgrp_poll_data.poll_lock, lock_flags);
down(&nd->nd_net_semaphore);
dgrp_monitor_message(nd, "Net Close");
up(&nd->nd_net_semaphore);
done:
module_put(THIS_MODULE);
file->private_data = NULL;
return 0;
}
/* used in dgrp_send to setup command header */
static inline u8 *set_cmd_header(u8 *b, u8 port, u8 cmd)
{
*b++ = 0xb0 + (port & 0x0f);
*b++ = cmd;
return b;
}
/**
* dgrp_send() -- build a packet for transmission to the server
* @nd: pointer to a node structure
* @tmax: maximum bytes to transmit
*
* returns number of bytes sent
*/
static int dgrp_send(struct nd_struct *nd, long tmax)
{
struct ch_struct *ch = nd->nd_chan;
u8 *b;
u8 *buf;
u8 *mbuf;
u8 port;
int mod;
long send;
int maxport;
long lastport = -1;
ushort rwin;
long in;
ushort n;
long t;
long ttotal;
long tchan;
long tsend;
ushort tsafe;
long work;
long send_sync;
long wanted_sync_port = -1;
ushort tdata[CHAN_MAX];
long used_buffer;
mbuf = nd->nd_iobuf + UIO_BASE;
buf = b = mbuf;
send_sync = nd->nd_link.lk_slow_rate < UIO_MAX;
ttotal = 0;
tchan = 0;
memset(tdata, 0, sizeof(tdata));
/*
* If there are any outstanding requests to be serviced,
* service them here.
*/
if (nd->nd_send & NR_PASSWORD) {
/*
* Send Password response.
*/
b[0] = 0xfc;
b[1] = 0x20;
put_unaligned_be16(strlen(nd->password), b + 2);
b += 4;
b += strlen(nd->password);
nd->nd_send &= ~(NR_PASSWORD);
}
/*
* Loop over all modules to generate commands, and determine
* the amount of data queued for transmit.
*/
for (mod = 0, port = 0; port < nd->nd_chan_count; mod++) {
/*
* If this is not the current module, enter a module select
* code in the buffer.
*/
if (mod != nd->nd_tx_module)
mbuf = ++b;
/*
* Loop to process one module.
*/
maxport = port + 16;
if (maxport > nd->nd_chan_count)
maxport = nd->nd_chan_count;
for (; port < maxport; port++, ch++) {
/*
* Switch based on channel state.
*/
switch (ch->ch_state) {
/*
* Send requests when the port is closed, and there
* are no Open, Close or Cancel requests expected.
*/
case CS_IDLE:
/*
* Wait until any open error code
* has been delivered to all
* associated ports.
*/
if (ch->ch_open_error) {
if (ch->ch_wait_count[ch->ch_otype]) {
work = 1;
break;
}
ch->ch_open_error = 0;
}
/*
* Wait until the channel HANGUP flag is reset
* before sending the first open. We can only
* get to this state after a server disconnect.
*/
if ((ch->ch_flag & CH_HANGUP) != 0)
break;
/*
* If recovering from a TCP disconnect, or if
* there is an immediate open pending, send an
* Immediate Open request.
*/
if ((ch->ch_flag & CH_PORT_GONE) ||
ch->ch_wait_count[OTYPE_IMMEDIATE] != 0) {
b = set_cmd_header(b, port, 10);
*b++ = 0;
ch->ch_state = CS_WAIT_OPEN;
ch->ch_otype = OTYPE_IMMEDIATE;
break;
}
/*
* If there is no Persistent or Incoming Open on the wait
* list in the server, and a thread is waiting for a
* Persistent or Incoming Open, send a Persistent or Incoming
* Open Request.
*/
if (ch->ch_otype_waiting == 0) {
if (ch->ch_wait_count[OTYPE_PERSISTENT] != 0) {
b = set_cmd_header(b, port, 10);
*b++ = 1;
ch->ch_state = CS_WAIT_OPEN;
ch->ch_otype = OTYPE_PERSISTENT;
} else if (ch->ch_wait_count[OTYPE_INCOMING] != 0) {
b = set_cmd_header(b, port, 10);
*b++ = 2;
ch->ch_state = CS_WAIT_OPEN;
ch->ch_otype = OTYPE_INCOMING;
}
break;
}
/*
* If a Persistent or Incoming Open is pending in
* the server, but there is no longer an open
* thread waiting for it, cancel the request.
*/
if (ch->ch_wait_count[ch->ch_otype_waiting] == 0) {
b = set_cmd_header(b, port, 10);
*b++ = 4;
ch->ch_state = CS_WAIT_CANCEL;
ch->ch_otype = ch->ch_otype_waiting;
}
break;
/*
* Send port parameter queries.
*/
case CS_SEND_QUERY:
/*
* Clear out all FEP state that might remain
* from the last connection.
*/
ch->ch_flag |= CH_PARAM;
ch->ch_flag &= ~CH_RX_FLUSH;
ch->ch_expect = 0;
ch->ch_s_tin = 0;
ch->ch_s_tpos = 0;
ch->ch_s_tsize = 0;
ch->ch_s_treq = 0;
ch->ch_s_elast = 0;
ch->ch_s_rin = 0;
ch->ch_s_rwin = 0;
ch->ch_s_rsize = 0;
ch->ch_s_tmax = 0;
ch->ch_s_ttime = 0;
ch->ch_s_rmax = 0;
ch->ch_s_rtime = 0;
ch->ch_s_rlow = 0;
ch->ch_s_rhigh = 0;
ch->ch_s_brate = 0;
ch->ch_s_iflag = 0;
ch->ch_s_cflag = 0;
ch->ch_s_oflag = 0;
ch->ch_s_xflag = 0;
ch->ch_s_mout = 0;
ch->ch_s_mflow = 0;
ch->ch_s_mctrl = 0;
ch->ch_s_xon = 0;
ch->ch_s_xoff = 0;
ch->ch_s_lnext = 0;
ch->ch_s_xxon = 0;
ch->ch_s_xxoff = 0;
/* Send Sequence Request */
b = set_cmd_header(b, port, 14);
/* Configure Event Conditions Packet */
b = set_cmd_header(b, port, 42);
put_unaligned_be16(0x02c0, b);
b += 2;
*b++ = (DM_DTR | DM_RTS | DM_CTS |
DM_DSR | DM_RI | DM_CD);
/* Send Status Request */
b = set_cmd_header(b, port, 16);
/* Send Buffer Request */
b = set_cmd_header(b, port, 20);
/* Send Port Capability Request */
b = set_cmd_header(b, port, 22);
ch->ch_expect = (RR_SEQUENCE |
RR_STATUS |
RR_BUFFER |
RR_CAPABILITY);
ch->ch_state = CS_WAIT_QUERY;
/* Raise modem signals */
b = set_cmd_header(b, port, 44);
if (ch->ch_flag & CH_PORT_GONE)
ch->ch_s_mout = ch->ch_mout;
else
ch->ch_s_mout = ch->ch_mout = DM_DTR | DM_RTS;
*b++ = ch->ch_mout;
*b++ = ch->ch_s_mflow = 0;
*b++ = ch->ch_s_mctrl = ch->ch_mctrl = 0;
if (ch->ch_flag & CH_PORT_GONE)
ch->ch_flag &= ~CH_PORT_GONE;
break;
/*
* Handle normal open and ready mode.
*/
case CS_READY:
/*
* If the port is not open, and there are no
* no longer any ports requesting an open,
* then close the port.
*/
if (ch->ch_open_count == 0 &&
ch->ch_wait_count[ch->ch_otype] == 0) {
goto send_close;
}
/*
* Process waiting input.
*
* If there is no one to read it, discard the data.
*
* Otherwise if we are not in fastcook mode, or if there is a
* fastcook thread waiting for data, send the data to the
* line discipline.
*/
if (ch->ch_rin != ch->ch_rout) {
if (ch->ch_tun.un_open_count == 0 ||
(ch->ch_tun.un_flag & UN_CLOSING) ||
(ch->ch_cflag & CF_CREAD) == 0) {
ch->ch_rout = ch->ch_rin;
} else if ((ch->ch_flag & CH_FAST_READ) == 0 ||
ch->ch_inwait != 0) {
dgrp_input(ch);
if (ch->ch_rin != ch->ch_rout)
work = 1;
}
}
/*
* Handle receive flush, and changes to
* server port parameters.
*/
if (ch->ch_flag & (CH_RX_FLUSH | CH_PARAM)) {
/*
* If we are in receive flush mode,
* and enough data has gone by, reset
* receive flush mode.
*/
if (ch->ch_flag & CH_RX_FLUSH) {
if (((ch->ch_flush_seq - nd->nd_seq_out) & SEQ_MASK) >
((nd->nd_seq_in - nd->nd_seq_out) & SEQ_MASK))
ch->ch_flag &= ~CH_RX_FLUSH;
else
work = 1;
}
/*
* Send TMAX, TTIME.
*/
if (ch->ch_s_tmax != ch->ch_tmax ||
ch->ch_s_ttime != ch->ch_ttime) {
b = set_cmd_header(b, port, 48);
ch->ch_s_tmax = ch->ch_tmax;
ch->ch_s_ttime = ch->ch_ttime;
put_unaligned_be16(ch->ch_s_tmax,
b);
b += 2;
put_unaligned_be16(ch->ch_s_ttime,
b);
b += 2;
}
/*
* Send RLOW, RHIGH.
*/
if (ch->ch_s_rlow != ch->ch_rlow ||
ch->ch_s_rhigh != ch->ch_rhigh) {
b = set_cmd_header(b, port, 45);
ch->ch_s_rlow = ch->ch_rlow;
ch->ch_s_rhigh = ch->ch_rhigh;
put_unaligned_be16(ch->ch_s_rlow,
b);
b += 2;
put_unaligned_be16(ch->ch_s_rhigh,
b);
b += 2;
}
/*
* Send BRATE, CFLAG, IFLAG,
* OFLAG, XFLAG.
*/
if (ch->ch_s_brate != ch->ch_brate ||
ch->ch_s_cflag != ch->ch_cflag ||
ch->ch_s_iflag != ch->ch_iflag ||
ch->ch_s_oflag != ch->ch_oflag ||
ch->ch_s_xflag != ch->ch_xflag) {
b = set_cmd_header(b, port, 40);
ch->ch_s_brate = ch->ch_brate;
ch->ch_s_cflag = ch->ch_cflag;
ch->ch_s_iflag = ch->ch_iflag;
ch->ch_s_oflag = ch->ch_oflag;
ch->ch_s_xflag = ch->ch_xflag;
put_unaligned_be16(ch->ch_s_brate,
b);
b += 2;
put_unaligned_be16(ch->ch_s_cflag,
b);
b += 2;
put_unaligned_be16(ch->ch_s_iflag,
b);
b += 2;
put_unaligned_be16(ch->ch_s_oflag,
b);
b += 2;
put_unaligned_be16(ch->ch_s_xflag,
b);
b += 2;
}
/*
* Send MOUT, MFLOW, MCTRL.
*/
if (ch->ch_s_mout != ch->ch_mout ||
ch->ch_s_mflow != ch->ch_mflow ||
ch->ch_s_mctrl != ch->ch_mctrl) {
b = set_cmd_header(b, port, 44);
*b++ = ch->ch_s_mout = ch->ch_mout;
*b++ = ch->ch_s_mflow = ch->ch_mflow;
*b++ = ch->ch_s_mctrl = ch->ch_mctrl;
}
/*
* Send Flow control characters.
*/
if (ch->ch_s_xon != ch->ch_xon ||
ch->ch_s_xoff != ch->ch_xoff ||
ch->ch_s_lnext != ch->ch_lnext ||
ch->ch_s_xxon != ch->ch_xxon ||
ch->ch_s_xxoff != ch->ch_xxoff) {
b = set_cmd_header(b, port, 46);
*b++ = ch->ch_s_xon = ch->ch_xon;
*b++ = ch->ch_s_xoff = ch->ch_xoff;
*b++ = ch->ch_s_lnext = ch->ch_lnext;
*b++ = ch->ch_s_xxon = ch->ch_xxon;
*b++ = ch->ch_s_xxoff = ch->ch_xxoff;
}
/*
* Send RMAX, RTIME.
*/
if (ch->ch_s_rmax != ch->ch_rmax ||
ch->ch_s_rtime != ch->ch_rtime) {
b = set_cmd_header(b, port, 47);
ch->ch_s_rmax = ch->ch_rmax;
ch->ch_s_rtime = ch->ch_rtime;
put_unaligned_be16(ch->ch_s_rmax,
b);
b += 2;
put_unaligned_be16(ch->ch_s_rtime,
b);
b += 2;
}
ch->ch_flag &= ~CH_PARAM;
wake_up_interruptible(&ch->ch_flag_wait);
}
/*
* Handle action commands.
*/
if (ch->ch_send != 0) {
/* int send = ch->ch_send & ~ch->ch_expect; */
send = ch->ch_send & ~ch->ch_expect;
/* Send character immediate */
if ((send & RR_TX_ICHAR) != 0) {
b = set_cmd_header(b, port, 60);
*b++ = ch->ch_xon;
ch->ch_expect |= RR_TX_ICHAR;
}
/* BREAK request */
if ((send & RR_TX_BREAK) != 0) {
if (ch->ch_break_time != 0) {
b = set_cmd_header(b, port, 61);
put_unaligned_be16(ch->ch_break_time,
b);
b += 2;
ch->ch_expect |= RR_TX_BREAK;
ch->ch_break_time = 0;
} else {
ch->ch_send &= ~RR_TX_BREAK;
ch->ch_flag &= ~CH_TX_BREAK;
wake_up_interruptible(&ch->ch_flag_wait);
}
}
/*
* Flush input/output buffers.
*/
if ((send & (RR_RX_FLUSH | RR_TX_FLUSH)) != 0) {
b = set_cmd_header(b, port, 62);
*b++ = ((send & RR_TX_FLUSH) == 0 ? 1 :
(send & RR_RX_FLUSH) == 0 ? 2 : 3);
if (send & RR_RX_FLUSH) {
ch->ch_flush_seq = nd->nd_seq_in;
ch->ch_flag |= CH_RX_FLUSH;
work = 1;
send_sync = 1;
wanted_sync_port = port;
}
ch->ch_send &= ~(RR_RX_FLUSH | RR_TX_FLUSH);
}
/* Pause input/output */
if ((send & (RR_RX_STOP | RR_TX_STOP)) != 0) {
b = set_cmd_header(b, port, 63);
*b = 0;
if ((send & RR_TX_STOP) != 0)
*b |= EV_OPU;
if ((send & RR_RX_STOP) != 0)
*b |= EV_IPU;
b++;
ch->ch_send &= ~(RR_RX_STOP | RR_TX_STOP);
}
/* Start input/output */
if ((send & (RR_RX_START | RR_TX_START)) != 0) {
b = set_cmd_header(b, port, 64);
*b = 0;
if ((send & RR_TX_START) != 0)
*b |= EV_OPU | EV_OPS | EV_OPX;
if ((send & RR_RX_START) != 0)
*b |= EV_IPU | EV_IPS;
b++;
ch->ch_send &= ~(RR_RX_START | RR_TX_START);
}
}
/*
* Send a window sequence to acknowledge received data.
*/
rwin = (ch->ch_s_rin +
((ch->ch_rout - ch->ch_rin - 1) & RBUF_MASK));
n = (rwin - ch->ch_s_rwin) & 0xffff;
if (n >= RBUF_MAX / 4) {
b[0] = 0xa0 + (port & 0xf);
ch->ch_s_rwin = rwin;
put_unaligned_be16(rwin, b + 1);
b += 3;
}
/*
* If the terminal is waiting on LOW
* water or EMPTY, and the condition
* is now satisfied, call the line
* discipline to put more data in the
* buffer.
*/
n = (ch->ch_tin - ch->ch_tout) & TBUF_MASK;
if ((ch->ch_tun.un_flag & (UN_EMPTY|UN_LOW)) != 0) {
if ((ch->ch_tun.un_flag & UN_LOW) != 0 ?
(n <= TBUF_LOW) :
(n == 0 && ch->ch_s_tpos == ch->ch_s_tin)) {
ch->ch_tun.un_flag &= ~(UN_EMPTY|UN_LOW);
if (waitqueue_active(&((ch->ch_tun.un_tty)->write_wait)))
wake_up_interruptible(&((ch->ch_tun.un_tty)->write_wait));
tty_wakeup(ch->ch_tun.un_tty);
n = (ch->ch_tin - ch->ch_tout) & TBUF_MASK;
}
}
/*
* If the printer is waiting on LOW
* water, TIME, EMPTY or PWAIT, and is
* now ready to put more data in the
* buffer, call the line discipline to
* do the job.
*/
/* FIXME: jiffies - ch->ch_waketime can never
be < 0. Someone needs to work out what is
actually intended here */
if (ch->ch_pun.un_open_count &&
(ch->ch_pun.un_flag &
(UN_EMPTY|UN_TIME|UN_LOW|UN_PWAIT)) != 0) {
if ((ch->ch_pun.un_flag & UN_LOW) != 0 ?
(n <= TBUF_LOW) :
(ch->ch_pun.un_flag & UN_TIME) != 0 ?
time_is_before_jiffies(ch->ch_waketime) :
(n == 0 && ch->ch_s_tpos == ch->ch_s_tin) &&
((ch->ch_pun.un_flag & UN_EMPTY) != 0 ||
((ch->ch_tun.un_open_count &&
ch->ch_tun.un_tty->ops->chars_in_buffer) ?
(ch->ch_tun.un_tty->ops->chars_in_buffer)(ch->ch_tun.un_tty) == 0
: 1
)
)) {
ch->ch_pun.un_flag &= ~(UN_EMPTY | UN_TIME | UN_LOW | UN_PWAIT);
if (waitqueue_active(&((ch->ch_pun.un_tty)->write_wait)))
wake_up_interruptible(&((ch->ch_pun.un_tty)->write_wait));
tty_wakeup(ch->ch_pun.un_tty);
n = (ch->ch_tin - ch->ch_tout) & TBUF_MASK;
} else if ((ch->ch_pun.un_flag & UN_TIME) != 0) {
work = 1;
}
}
/*
* Determine the max number of bytes
* this port can send, including
* packet header overhead.
*/
t = ((ch->ch_s_tsize + ch->ch_s_tpos - ch->ch_s_tin) & 0xffff);
if (n > t)
n = t;
if (n != 0) {
n += (n <= 8 ? 1 : n <= 255 ? 2 : 3);
tdata[tchan++] = n;
ttotal += n;
}
break;
/*
* Close the port.
*/
send_close:
case CS_SEND_CLOSE:
b = set_cmd_header(b, port, 10);
if (ch->ch_otype == OTYPE_IMMEDIATE)
*b++ = 3;
else
*b++ = 4;
ch->ch_state = CS_WAIT_CLOSE;
break;
/*
* Wait for a previous server request.
*/
case CS_WAIT_OPEN:
case CS_WAIT_CANCEL:
case CS_WAIT_FAIL:
case CS_WAIT_QUERY:
case CS_WAIT_CLOSE:
break;
default:
pr_info("%s - unexpected channel state (%i)\n",
__func__, ch->ch_state);
}
}
/*
* If a module select code is needed, drop one in. If space
* was reserved for one, but none is needed, recover the space.
*/
if (mod != nd->nd_tx_module) {
if (b != mbuf) {
mbuf[-1] = 0xf0 | mod;
nd->nd_tx_module = mod;
} else {
b--;
}
}
}
/*
* Adjust "tmax" so that under worst case conditions we do
* not overflow either the daemon buffer or the internal
* buffer in the loop that follows. Leave a safe area
* of 64 bytes so we start getting asserts before we start
* losing data or clobbering memory.
*/
n = UIO_MAX - UIO_BASE;
if (tmax > n)
tmax = n;
tmax -= 64;
tsafe = tmax;
/*
* Allocate space for 5 Module Selects, 1 Sequence Request,
* and 1 Set TREQ for each active channel.
*/
tmax -= 5 + 3 + 4 * nd->nd_chan_count;
/*
* Further reduce "tmax" to the available transmit credit.
* Note that this is a soft constraint; The transmit credit
* can go negative for a time and then recover.
*/
n = nd->nd_tx_deposit - nd->nd_tx_charge - nd->nd_link.lk_header_size;
if (tmax > n)
tmax = n;
/*
* Finally reduce tmax by the number of bytes already in
* the buffer.
*/
tmax -= b - buf;
/*
* Suspend data transmit unless every ready channel can send
* at least 1 character.
*/
if (tmax < 2 * nd->nd_chan_count) {
tsend = 1;
} else if (tchan > 1 && ttotal > tmax) {
/*
* If transmit is limited by the credit budget, find the
* largest number of characters we can send without driving
* the credit negative.
*/
long tm = tmax;
int tc = tchan;
int try;
tsend = tm / tc;
for (try = 0; try < 3; try++) {
int i;
int c = 0;
for (i = 0; i < tc; i++) {
if (tsend < tdata[i])
tdata[c++] = tdata[i];
else
tm -= tdata[i];
}
if (c == tc)
break;
tsend = tm / c;
if (c == 1)
break;
tc = c;
}
tsend = tm / nd->nd_chan_count;
if (tsend < 2)
tsend = 1;
} else {
/*
* If no budgetary constraints, or only one channel ready
* to send, set the character limit to the remaining
* buffer size.
*/
tsend = tmax;
}
tsend -= (tsend <= 9) ? 1 : (tsend <= 257) ? 2 : 3;
/*
* Loop over all channels, sending queued data.
*/
port = 0;
ch = nd->nd_chan;
used_buffer = tmax;
for (mod = 0; port < nd->nd_chan_count; mod++) {
/*
* If this is not the current module, enter a module select
* code in the buffer.
*/
if (mod != nd->nd_tx_module)
mbuf = ++b;
/*
* Loop to process one module.
*/
maxport = port + 16;
if (maxport > nd->nd_chan_count)
maxport = nd->nd_chan_count;
for (; port < maxport; port++, ch++) {
if (ch->ch_state != CS_READY)
continue;
lastport = port;
n = (ch->ch_tin - ch->ch_tout) & TBUF_MASK;
/*
* If there is data that can be sent, send it.
*/
if (n != 0 && used_buffer > 0) {
t = (ch->ch_s_tsize + ch->ch_s_tpos - ch->ch_s_tin) & 0xffff;
if (n > t)
n = t;
if (n > tsend) {
work = 1;
n = tsend;
}
if (n > used_buffer) {
work = 1;
n = used_buffer;
}
if (n <= 0)
continue;
/*
* Create the correct size transmit header,
* depending on the amount of data to transmit.
*/
if (n <= 8) {
b[0] = ((n - 1) << 4) + (port & 0xf);
b += 1;
} else if (n <= 255) {
b[0] = 0x80 + (port & 0xf);
b[1] = n;
b += 2;
} else {
b[0] = 0x90 + (port & 0xf);
put_unaligned_be16(n, b + 1);
b += 3;
}
ch->ch_s_tin = (ch->ch_s_tin + n) & 0xffff;
/*
* Copy transmit data to the packet.
*/
t = TBUF_MAX - ch->ch_tout;
if (n >= t) {
memcpy(b, ch->ch_tbuf + ch->ch_tout, t);
b += t;
n -= t;
used_buffer -= t;
ch->ch_tout = 0;
}
memcpy(b, ch->ch_tbuf + ch->ch_tout, n);
b += n;
used_buffer -= n;
ch->ch_tout += n;
n = (ch->ch_tin - ch->ch_tout) & TBUF_MASK;
}
/*
* Wake any terminal unit process waiting in the
* dgrp_write routine for low water.
*/
if (n > TBUF_LOW)
continue;
if ((ch->ch_flag & CH_LOW) != 0) {
ch->ch_flag &= ~CH_LOW;
wake_up_interruptible(&ch->ch_flag_wait);
}
/* selwakeup tty_sel */
if (ch->ch_tun.un_open_count) {
struct tty_struct *tty = (ch->ch_tun.un_tty);
if (waitqueue_active(&tty->write_wait))
wake_up_interruptible(&tty->write_wait);
tty_wakeup(tty);
}
if (ch->ch_pun.un_open_count) {
struct tty_struct *tty = (ch->ch_pun.un_tty);
if (waitqueue_active(&tty->write_wait))
wake_up_interruptible(&tty->write_wait);
tty_wakeup(tty);
}
/*
* Do EMPTY processing.
*/
if (n != 0)
continue;
if ((ch->ch_flag & (CH_EMPTY | CH_DRAIN)) != 0 ||
(ch->ch_pun.un_flag & UN_EMPTY) != 0) {
/*
* If there is still data in the server, ask the server
* to notify us when its all gone.
*/
if (ch->ch_s_treq != ch->ch_s_tin) {
b = set_cmd_header(b, port, 43);
ch->ch_s_treq = ch->ch_s_tin;
put_unaligned_be16(ch->ch_s_treq,
b);
b += 2;
}
/*
* If there is a thread waiting for buffer empty,
* and we are truly empty, wake the thread.
*/
else if ((ch->ch_flag & CH_EMPTY) != 0 &&
(ch->ch_send & RR_TX_BREAK) == 0) {
ch->ch_flag &= ~CH_EMPTY;
wake_up_interruptible(&ch->ch_flag_wait);
}
}
}
/*
* If a module select code is needed, drop one in. If space
* was reserved for one, but none is needed, recover the space.
*/
if (mod != nd->nd_tx_module) {
if (b != mbuf) {
mbuf[-1] = 0xf0 | mod;
nd->nd_tx_module = mod;
} else {
b--;
}
}
}
/*
* Send a synchronization sequence associated with the last open
* channel that sent data, and remember the time when the data was
* sent.
*/
in = nd->nd_seq_in;
if ((send_sync || nd->nd_seq_wait[in] != 0) && lastport >= 0) {
u8 *bb = b;
/*
* Attempt the use the port that really wanted the sync.
* This gets around a race condition where the "lastport" is in
* the middle of the close() routine, and by the time we
* send this command, it will have already acked the close, and
* thus not send the sync response.
*/
if (wanted_sync_port >= 0)
lastport = wanted_sync_port;
/*
* Set a flag just in case the port is in the middle of a close,
* it will not be permitted to actually close until we get an
* sync response, and clear the flag there.
*/
ch = nd->nd_chan + lastport;
ch->ch_flag |= CH_WAITING_SYNC;
mod = lastport >> 4;
if (mod != nd->nd_tx_module) {
bb[0] = 0xf0 + mod;
bb += 1;
nd->nd_tx_module = mod;
}
bb = set_cmd_header(bb, lastport, 12);
*bb++ = in;
nd->nd_seq_size[in] = bb - buf;
nd->nd_seq_time[in] = jiffies;
if (++in >= SEQ_MAX)
in = 0;
if (in != nd->nd_seq_out) {
b = bb;
nd->nd_seq_in = in;
nd->nd_unack += b - buf;
}
}
/*
* If there are no open ports, a sync cannot be sent.
* There is nothing left to wait for anyway, so wake any
* thread waiting for an acknowledgement.
*/
else if (nd->nd_seq_wait[in] != 0) {
nd->nd_seq_wait[in] = 0;
wake_up_interruptible(&nd->nd_seq_wque[in]);
}
/*
* If there is no traffic for an interval of IDLE_MAX, then
* send a single byte packet.
*/
if (b != buf) {
nd->nd_tx_time = jiffies;
} else if ((ulong)(jiffies - nd->nd_tx_time) >= IDLE_MAX) {
*b++ = 0xf0 | nd->nd_tx_module;
nd->nd_tx_time = jiffies;
}
n = b - buf;
if (n >= tsafe)
pr_info("%s - n(%i) >= tsafe(%i)\n",
__func__, n, tsafe);
if (tsend < 0)
dgrp_dump(buf, n);
nd->nd_tx_work = work;
return n;
}
/*
* dgrp_net_read()
* Data to be sent TO the PortServer from the "async." half of the driver.
*/
static ssize_t dgrp_net_read(struct file *file, char __user *buf, size_t count,
loff_t *ppos)
{
struct nd_struct *nd;
long n;
u8 *local_buf;
u8 *b;
ssize_t rtn;
/*
* Get the node pointer, and quit if it doesn't exist.
*/
nd = (struct nd_struct *)(file->private_data);
if (!nd)
return -ENXIO;
if (count < UIO_MIN)
return -EINVAL;
/*
* Only one read/write operation may be in progress at
* any given time.
*/
/*
* Grab the NET lock.
*/
down(&nd->nd_net_semaphore);
nd->nd_read_count++;
nd->nd_tx_ready = 0;
/*
* Determine the effective size of the buffer.
*/
if (nd->nd_remain > UIO_BASE)
pr_info_ratelimited("%s - nd_remain(%i) > UIO_BASE\n",
__func__, nd->nd_remain);
b = local_buf = nd->nd_iobuf + UIO_BASE;
/*
* Generate data according to the node state.
*/
switch (nd->nd_state) {
/*
* Initialize the connection.
*/
case NS_IDLE:
if (nd->nd_mon_buf)
dgrp_monitor_reset(nd);
/*
* Request a Product ID Packet.
*/
b[0] = 0xfb;
b[1] = 0x01;
b += 2;
nd->nd_expect |= NR_IDENT;
/*
* Request a Server Capability ID Response.
*/
b[0] = 0xfb;
b[1] = 0x02;
b += 2;
nd->nd_expect |= NR_CAPABILITY;
/*
* Request a Server VPD Response.
*/
b[0] = 0xfb;
b[1] = 0x18;
b += 2;
nd->nd_expect |= NR_VPD;
nd->nd_state = NS_WAIT_QUERY;
break;
/*
* We do serious communication with the server only in
* the READY state.
*/
case NS_READY:
b = dgrp_send(nd, count) + local_buf;
break;
/*
* Send off an error after receiving a bogus message
* from the server.
*/
case NS_SEND_ERROR:
n = strlen(nd->nd_error);
b[0] = 0xff;
b[1] = n;
memcpy(b + 2, nd->nd_error, n);
b += 2 + n;
dgrp_net_idle(nd);
/*
* Set the active port count to zero.
*/
dgrp_chan_count(nd, 0);
break;
default:
break;
}
n = b - local_buf;
if (n != 0) {
nd->nd_send_count++;
nd->nd_tx_byte += n + nd->nd_link.lk_header_size;
nd->nd_tx_charge += n + nd->nd_link.lk_header_size;
}
rtn = copy_to_user((void __user *)buf, local_buf, n);
if (rtn) {
rtn = -EFAULT;
goto done;
}
*ppos += n;
rtn = n;
if (nd->nd_mon_buf)
dgrp_monitor_data(nd, RPDUMP_CLIENT, local_buf, n);
/*
* Release the NET lock.
*/
done:
up(&nd->nd_net_semaphore);
return rtn;
}
/**
* dgrp_receive() -- decode data packets received from the remote PortServer.
* @nd: pointer to a node structure
*/
static void dgrp_receive(struct nd_struct *nd)
{
struct ch_struct *ch;
u8 *buf;
u8 *b;
u8 *dbuf;
char *error;
long port;
long dlen;
long plen;
long remain;
long n;
long mlast;
long elast;
long mstat;
long estat;
char ID[3];
nd->nd_tx_time = jiffies;
ID_TO_CHAR(nd->nd_ID, ID);
b = buf = nd->nd_iobuf;
remain = nd->nd_remain;
/*
* Loop to process Realport protocol packets.
*/
while (remain > 0) {
int n0 = b[0] >> 4;
int n1 = b[0] & 0x0f;
if (n0 <= 12) {
port = (nd->nd_rx_module << 4) + n1;
if (port >= nd->nd_chan_count) {
error = "Improper Port Number";
goto prot_error;
}
ch = nd->nd_chan + port;
} else {
port = -1;
ch = NULL;
}
/*
* Process by major packet type.
*/
switch (n0) {
/*
* Process 1-byte header data packet.
*/
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
dlen = n0 + 1;
plen = dlen + 1;
dbuf = b + 1;
goto data;
/*
* Process 2-byte header data packet.
*/
case 8:
if (remain < 3)
goto done;
dlen = b[1];
plen = dlen + 2;
dbuf = b + 2;
goto data;
/*
* Process 3-byte header data packet.
*/
case 9:
if (remain < 4)
goto done;
dlen = get_unaligned_be16(b + 1);
plen = dlen + 3;
dbuf = b + 3;
/*
* Common packet handling code.
*/
data:
nd->nd_tx_work = 1;
/*
* Otherwise data should appear only when we are
* in the CS_READY state.
*/
if (ch->ch_state < CS_READY) {
error = "Data received before RWIN established";
goto prot_error;
}
/*
* Assure that the data received is within the
* allowable window.
*/
n = (ch->ch_s_rwin - ch->ch_s_rin) & 0xffff;
if (dlen > n) {
error = "Receive data overrun";
goto prot_error;
}
/*
* If we received 3 or less characters,
* assume it is a human typing, and set RTIME
* to 10 milliseconds.
*
* If we receive 10 or more characters,
* assume its not a human typing, and set RTIME
* to 100 milliseconds.
*/
if (ch->ch_edelay != DGRP_RTIME) {
if (ch->ch_rtime != ch->ch_edelay) {
ch->ch_rtime = ch->ch_edelay;
ch->ch_flag |= CH_PARAM;
}
} else if (dlen <= 3) {
if (ch->ch_rtime != 10) {
ch->ch_rtime = 10;
ch->ch_flag |= CH_PARAM;
}
} else {
if (ch->ch_rtime != DGRP_RTIME) {
ch->ch_rtime = DGRP_RTIME;
ch->ch_flag |= CH_PARAM;
}
}
/*
* If a portion of the packet is outside the
* buffer, shorten the effective length of the
* data packet to be the amount of data received.
*/
if (remain < plen)
dlen -= plen - remain;
/*
* Detect if receive flush is now complete.
*/
if ((ch->ch_flag & CH_RX_FLUSH) != 0 &&
((ch->ch_flush_seq - nd->nd_seq_out) & SEQ_MASK) >=
((nd->nd_seq_in - nd->nd_seq_out) & SEQ_MASK)) {
ch->ch_flag &= ~CH_RX_FLUSH;
}
/*
* If we are ready to receive, move the data into
* the receive buffer.
*/
ch->ch_s_rin = (ch->ch_s_rin + dlen) & 0xffff;
if (ch->ch_state == CS_READY &&
(ch->ch_tun.un_open_count != 0) &&
(ch->ch_tun.un_flag & UN_CLOSING) == 0 &&
(ch->ch_cflag & CF_CREAD) != 0 &&
(ch->ch_flag & (CH_BAUD0 | CH_RX_FLUSH)) == 0 &&
(ch->ch_send & RR_RX_FLUSH) == 0) {
if (ch->ch_rin + dlen >= RBUF_MAX) {
n = RBUF_MAX - ch->ch_rin;
memcpy(ch->ch_rbuf + ch->ch_rin, dbuf, n);
ch->ch_rin = 0;
dbuf += n;
dlen -= n;
}
memcpy(ch->ch_rbuf + ch->ch_rin, dbuf, dlen);
ch->ch_rin += dlen;
/*
* If we are not in fastcook mode, or
* if there is a fastcook thread
* waiting for data, send the data to
* the line discipline.
*/
if ((ch->ch_flag & CH_FAST_READ) == 0 ||
ch->ch_inwait != 0) {
dgrp_input(ch);
}
/*
* If there is a read thread waiting
* in select, and we are in fastcook
* mode, wake him up.
*/
if (waitqueue_active(&ch->ch_tun.un_tty->read_wait) &&
(ch->ch_flag & CH_FAST_READ) != 0)
wake_up_interruptible(&ch->ch_tun.un_tty->read_wait);
/*
* Wake any thread waiting in the
* fastcook loop.
*/
if ((ch->ch_flag & CH_INPUT) != 0) {
ch->ch_flag &= ~CH_INPUT;
wake_up_interruptible(&ch->ch_flag_wait);
}
}
/*
* Fabricate and insert a data packet header to
* preced the remaining data when it comes in.
*/
if (remain < plen) {
dlen = plen - remain;
b = buf;
b[0] = 0x90 + n1;
put_unaligned_be16(dlen, b + 1);
remain = 3;
goto done;
}
break;
/*
* Handle Window Sequence packets.
*/
case 10:
plen = 3;
if (remain < plen)
goto done;
nd->nd_tx_work = 1;
{
ushort tpos = get_unaligned_be16(b + 1);
ushort ack = (tpos - ch->ch_s_tpos) & 0xffff;
ushort unack = (ch->ch_s_tin - ch->ch_s_tpos) & 0xffff;
ushort notify = (ch->ch_s_treq - ch->ch_s_tpos) & 0xffff;
if (ch->ch_state < CS_READY || ack > unack) {
error = "Improper Window Sequence";
goto prot_error;
}
ch->ch_s_tpos = tpos;
if (notify <= ack)
ch->ch_s_treq = tpos;
}
break;
/*
* Handle Command response packets.
*/
case 11:
/*
* RealPort engine fix - 03/11/2004
*
* This check did not used to be here.
*
* We were using b[1] without verifying that the data
* is actually there and valid. On a split packet, it
* might not be yet.
*
* NOTE: I have never actually seen the failure happen
* under Linux, but since I have seen it occur
* under both Solaris and HP-UX, the assumption
* is that it *could* happen here as well...
*/
if (remain < 2)
goto done;
switch (b[1]) {
/*
* Handle Open Response.
*/
case 11:
plen = 6;
if (remain < plen)
goto done;
nd->nd_tx_work = 1;
{
int req = b[2];
int resp = b[3];
port = get_unaligned_be16(b + 4);
if (port >= nd->nd_chan_count) {
error = "Open channel number out of range";
goto prot_error;
}
ch = nd->nd_chan + port;
/*
* How we handle an open response depends primarily
* on our current channel state.
*/
switch (ch->ch_state) {
case CS_IDLE:
/*
* Handle a delayed open.
*/
if (ch->ch_otype_waiting != 0 &&
req == ch->ch_otype_waiting &&
resp == 0) {
ch->ch_otype = req;
ch->ch_otype_waiting = 0;
ch->ch_state = CS_SEND_QUERY;
break;
}
goto open_error;
case CS_WAIT_OPEN:
/*
* Handle the open response.
*/
if (req == ch->ch_otype) {
switch (resp) {
/*
* On successful response, open the
* port and proceed normally.
*/
case 0:
ch->ch_state = CS_SEND_QUERY;
break;
/*
* On a busy response to a persistent open,
* remember that the open is pending.
*/
case 1:
case 2:
if (req != OTYPE_IMMEDIATE) {
ch->ch_otype_waiting = req;
ch->ch_state = CS_IDLE;
break;
}
/*
* Otherwise the server open failed. If
* the Unix port is open, hang it up.
*/
default:
if (ch->ch_open_count != 0) {
ch->ch_flag |= CH_HANGUP;
dgrp_carrier(ch);
ch->ch_state = CS_IDLE;
break;
}
ch->ch_open_error = resp;
ch->ch_state = CS_IDLE;
wake_up_interruptible(&ch->ch_flag_wait);
}
break;
}
/*
* Handle delayed response arrival preceding
* the open response we are waiting for.
*/
if (ch->ch_otype_waiting != 0 &&
req == ch->ch_otype_waiting &&
resp == 0) {
ch->ch_otype = ch->ch_otype_waiting;
ch->ch_otype_waiting = 0;
ch->ch_state = CS_WAIT_FAIL;
break;
}
goto open_error;
case CS_WAIT_FAIL:
/*
* Handle response to immediate open arriving
* after a delayed open success.
*/
if (req == OTYPE_IMMEDIATE) {
ch->ch_state = CS_SEND_QUERY;
break;
}
goto open_error;
case CS_WAIT_CANCEL:
/*
* Handle delayed open response arriving before
* the cancel response.
*/
if (req == ch->ch_otype_waiting &&
resp == 0) {
ch->ch_otype_waiting = 0;
break;
}
/*
* Handle cancel response.
*/
if (req == 4 && resp == 0) {
ch->ch_otype_waiting = 0;
ch->ch_state = CS_IDLE;
break;
}
goto open_error;
case CS_WAIT_CLOSE:
/*
* Handle a successful response to a port
* close.
*/
if (req >= 3) {
ch->ch_state = CS_IDLE;
break;
}
goto open_error;
open_error:
default:
{
error = "Improper Open Response";
goto prot_error;
}
}
}
break;
/*
* Handle Synchronize Response.
*/
case 13:
plen = 3;
if (remain < plen)
goto done;
{
int seq = b[2];
int s;
/*
* If channel was waiting for this sync response,
* unset the flag, and wake up anyone waiting
* on the event.
*/
if (ch->ch_flag & CH_WAITING_SYNC) {
ch->ch_flag &= ~(CH_WAITING_SYNC);
wake_up_interruptible(&ch->ch_flag_wait);
}
if (((seq - nd->nd_seq_out) & SEQ_MASK) >=
((nd->nd_seq_in - nd->nd_seq_out) & SEQ_MASK)) {
break;
}
for (s = nd->nd_seq_out;; s = (s + 1) & SEQ_MASK) {
if (nd->nd_seq_wait[s] != 0) {
nd->nd_seq_wait[s] = 0;
wake_up_interruptible(&nd->nd_seq_wque[s]);
}
nd->nd_unack -= nd->nd_seq_size[s];
if (s == seq)
break;
}
nd->nd_seq_out = (seq + 1) & SEQ_MASK;
}
break;
/*
* Handle Sequence Response.
*/
case 15:
plen = 6;
if (remain < plen)
goto done;
{
/* Record that we have received the Sequence
* Response, but we aren't interested in the
* sequence numbers. We were using RIN like it
* was ROUT and that was causing problems,
* fixed 7-13-2001 David Fries. See comment in
* drp.h for ch_s_rin variable.
int rin = get_unaligned_be16(b + 2);
int tpos = get_unaligned_be16(b + 4);
*/
ch->ch_send &= ~RR_SEQUENCE;
ch->ch_expect &= ~RR_SEQUENCE;
}
goto check_query;
/*
* Handle Status Response.
*/
case 17:
plen = 5;
if (remain < plen)
goto done;
{
ch->ch_s_elast = get_unaligned_be16(b + 2);
ch->ch_s_mlast = b[4];
ch->ch_expect &= ~RR_STATUS;
ch->ch_send &= ~RR_STATUS;
/*
* CH_PHYS_CD is cleared because something _could_ be
* waiting for the initial sense of carrier... and if
* carrier is high immediately, we want to be sure to
* wake them as soon as possible.
*/
ch->ch_flag &= ~CH_PHYS_CD;
dgrp_carrier(ch);
}
goto check_query;
/*
* Handle Line Error Response.
*/
case 19:
plen = 14;
if (remain < plen)
goto done;
break;
/*
* Handle Buffer Response.
*/
case 21:
plen = 6;
if (remain < plen)
goto done;
{
ch->ch_s_rsize = get_unaligned_be16(b + 2);
ch->ch_s_tsize = get_unaligned_be16(b + 4);
ch->ch_send &= ~RR_BUFFER;
ch->ch_expect &= ~RR_BUFFER;
}
goto check_query;
/*
* Handle Port Capability Response.
*/
case 23:
plen = 32;
if (remain < plen)
goto done;
{
ch->ch_send &= ~RR_CAPABILITY;
ch->ch_expect &= ~RR_CAPABILITY;
}
/*
* When all queries are complete, set those parameters
* derived from the query results, then transition
* to the READY state.
*/
check_query:
if (ch->ch_state == CS_WAIT_QUERY &&
(ch->ch_expect & (RR_SEQUENCE |
RR_STATUS |
RR_BUFFER |
RR_CAPABILITY)) == 0) {
ch->ch_tmax = ch->ch_s_tsize / 4;
if (ch->ch_edelay == DGRP_TTIME)
ch->ch_ttime = DGRP_TTIME;
else
ch->ch_ttime = ch->ch_edelay;
ch->ch_rmax = ch->ch_s_rsize / 4;
if (ch->ch_edelay == DGRP_RTIME)
ch->ch_rtime = DGRP_RTIME;
else
ch->ch_rtime = ch->ch_edelay;
ch->ch_rlow = 2 * ch->ch_s_rsize / 8;
ch->ch_rhigh = 6 * ch->ch_s_rsize / 8;
ch->ch_state = CS_READY;
nd->nd_tx_work = 1;
wake_up_interruptible(&ch->ch_flag_wait);
}
break;
default:
goto decode_error;
}
break;
/*
* Handle Events.
*/
case 12:
plen = 4;
if (remain < plen)
goto done;
mlast = ch->ch_s_mlast;
elast = ch->ch_s_elast;
mstat = ch->ch_s_mlast = b[1];
estat = ch->ch_s_elast = get_unaligned_be16(b + 2);
/*
* Handle modem changes.
*/
if (((mstat ^ mlast) & DM_CD) != 0)
dgrp_carrier(ch);
/*
* Handle received break.
*/
if ((estat & ~elast & EV_RXB) != 0 &&
(ch->ch_tun.un_open_count != 0) &&
I_BRKINT(ch->ch_tun.un_tty) &&
!(I_IGNBRK(ch->ch_tun.un_tty))) {
tty_buffer_request_room(&ch->port, 1);
tty_insert_flip_char(&ch->port, 0, TTY_BREAK);
tty_flip_buffer_push(&ch->port);
}
/*
* On transmit break complete, if more break traffic
* is waiting then send it. Otherwise wake any threads
* waiting for transmitter empty.
*/
if ((~estat & elast & EV_TXB) != 0 &&
(ch->ch_expect & RR_TX_BREAK) != 0) {
nd->nd_tx_work = 1;
ch->ch_expect &= ~RR_TX_BREAK;
if (ch->ch_break_time != 0) {
ch->ch_send |= RR_TX_BREAK;
} else {
ch->ch_send &= ~RR_TX_BREAK;
ch->ch_flag &= ~CH_TX_BREAK;
wake_up_interruptible(&ch->ch_flag_wait);
}
}
break;
case 13:
case 14:
error = "Unrecognized command";
goto prot_error;
/*
* Decode Special Codes.
*/
case 15:
switch (n1) {
/*
* One byte module select.
*/
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
plen = 1;
nd->nd_rx_module = n1;
break;
/*
* Two byte module select.
*/
case 8:
plen = 2;
if (remain < plen)
goto done;
nd->nd_rx_module = b[1];
break;
/*
* ID Request packet.
*/
case 11:
if (remain < 4)
goto done;
plen = get_unaligned_be16(b + 2);
if (plen < 12 || plen > 1000) {
error = "Response Packet length error";
goto prot_error;
}
nd->nd_tx_work = 1;
switch (b[1]) {
/*
* Echo packet.
*/
case 0:
nd->nd_send |= NR_ECHO;
break;
/*
* ID Response packet.
*/
case 1:
nd->nd_send |= NR_IDENT;
break;
/*
* ID Response packet.
*/
case 32:
nd->nd_send |= NR_PASSWORD;
break;
}
break;
/*
* Various node-level response packets.
*/
case 12:
if (remain < 4)
goto done;
plen = get_unaligned_be16(b + 2);
if (plen < 4 || plen > 1000) {
error = "Response Packet length error";
goto prot_error;
}
nd->nd_tx_work = 1;
switch (b[1]) {
/*
* Echo packet.
*/
case 0:
nd->nd_expect &= ~NR_ECHO;
break;
/*
* Product Response Packet.
*/
case 1:
{
int desclen;
nd->nd_hw_ver = (b[8] << 8) | b[9];
nd->nd_sw_ver = (b[10] << 8) | b[11];
nd->nd_hw_id = b[6];
desclen = (plen - 12 > MAX_DESC_LEN - 1) ? MAX_DESC_LEN - 1 :
plen - 12;
if (desclen <= 0) {
error = "Response Packet desclen error";
goto prot_error;
}
strncpy(nd->nd_ps_desc, b + 12, desclen);
nd->nd_ps_desc[desclen] = 0;
}
nd->nd_expect &= ~NR_IDENT;
break;
/*
* Capability Response Packet.
*/
case 2:
{
int nn = get_unaligned_be16(b + 4);
if (nn > CHAN_MAX)
nn = CHAN_MAX;
dgrp_chan_count(nd, nn);
}
nd->nd_expect &= ~NR_CAPABILITY;
break;
/*
* VPD Response Packet.
*/
case 15:
/*
* NOTE: case 15 is here ONLY because the EtherLite
* is broken, and sends a response to 24 back as 15.
* To resolve this, the EtherLite firmware is now
* fixed to send back 24 correctly, but, for backwards
* compatibility, we now have reserved 15 for the
* bad EtherLite response to 24 as well.
*/
/* Fallthru! */
case 24:
/*
* If the product doesn't support VPD,
* it will send back a null IDRESP,
* which is a length of 4 bytes.
*/
if (plen > 4) {
memcpy(nd->nd_vpd, b + 4, min(plen - 4, (long) VPDSIZE));
nd->nd_vpd_len = min(plen - 4, (long) VPDSIZE);
}
nd->nd_expect &= ~NR_VPD;
break;
default:
goto decode_error;
}
if (nd->nd_expect == 0 &&
nd->nd_state == NS_WAIT_QUERY) {
nd->nd_state = NS_READY;
}
break;
/*
* Debug packet.
*/
case 14:
if (remain < 4)
goto done;
plen = get_unaligned_be16(b + 2) + 4;
if (plen > 1000) {
error = "Debug Packet too large";
goto prot_error;
}
if (remain < plen)
goto done;
break;
/*
* Handle reset packet.
*/
case 15:
if (remain < 2)
goto done;
plen = 2 + b[1];
if (remain < plen)
goto done;
nd->nd_tx_work = 1;
n = b[plen];
b[plen] = 0;
b[plen] = n;
error = "Client Reset Acknowledge";
goto prot_error;
default:
goto decode_error;
}
break;
default:
goto decode_error;
}
b += plen;
remain -= plen;
}
/*
* When the buffer is exhausted, copy any data left at the
* top of the buffer back down to the bottom for the next
* read request.
*/
done:
if (remain > 0 && b != buf)
memcpy(buf, b, remain);
nd->nd_remain = remain;
return;
/*
* Handle a decode error.
*/
decode_error:
error = "Protocol decode error";
/*
* Handle a general protocol error.
*/
prot_error:
nd->nd_remain = 0;
nd->nd_state = NS_SEND_ERROR;
nd->nd_error = error;
}
/*
* dgrp_net_write() -- write data to the network device.
*
* A zero byte write indicates that the connection to the RealPort
* device has been broken.
*
* A non-zero write indicates data from the RealPort device.
*/
static ssize_t dgrp_net_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct nd_struct *nd;
ssize_t rtn = 0;
long n;
long total = 0;
/*
* Get the node pointer, and quit if it doesn't exist.
*/
nd = (struct nd_struct *)(file->private_data);
if (!nd)
return -ENXIO;
/*
* Grab the NET lock.
*/
down(&nd->nd_net_semaphore);
nd->nd_write_count++;
/*
* Handle disconnect.
*/
if (count == 0) {
dgrp_net_idle(nd);
/*
* Set the active port count to zero.
*/
dgrp_chan_count(nd, 0);
goto unlock;
}
/*
* Loop to process entire receive packet.
*/
while (count > 0) {
n = UIO_MAX - nd->nd_remain;
if (n > count)
n = count;
nd->nd_rx_byte += n + nd->nd_link.lk_header_size;
rtn = copy_from_user(nd->nd_iobuf + nd->nd_remain,
(void __user *) buf + total, n);
if (rtn) {
rtn = -EFAULT;
goto unlock;
}
*ppos += n;
total += n;
count -= n;
if (nd->nd_mon_buf)
dgrp_monitor_data(nd, RPDUMP_SERVER,
nd->nd_iobuf + nd->nd_remain, n);
nd->nd_remain += n;
dgrp_receive(nd);
}
rtn = total;
unlock:
/*
* Release the NET lock.
*/
up(&nd->nd_net_semaphore);
return rtn;
}
/*
* dgrp_net_select()
* Determine whether a device is ready to be read or written to, and
* sleep if not.
*/
static unsigned int dgrp_net_select(struct file *file,
struct poll_table_struct *table)
{
unsigned int retval = 0;
struct nd_struct *nd = file->private_data;
poll_wait(file, &nd->nd_tx_waitq, table);
if (nd->nd_tx_ready)
retval |= POLLIN | POLLRDNORM; /* Conditionally readable */
retval |= POLLOUT | POLLWRNORM; /* Always writeable */
return retval;
}
/*
* dgrp_net_ioctl
*
* Implement those functions which allow the network daemon to control
* the network parameters in the driver. The ioctls include ones to
* get and set the link speed parameters for the PortServer.
*/
static long dgrp_net_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct nd_struct *nd;
int rtn = 0;
long size = _IOC_SIZE(cmd);
struct link_struct link;
nd = file->private_data;
if (_IOC_DIR(cmd) & _IOC_READ)
rtn = access_ok(VERIFY_WRITE, (void __user *) arg, size);
else if (_IOC_DIR(cmd) & _IOC_WRITE)
rtn = access_ok(VERIFY_READ, (void __user *) arg, size);
if (!rtn)
return rtn;
switch (cmd) {
case DIGI_SETLINK:
if (size != sizeof(struct link_struct))
return -EINVAL;
if (copy_from_user(&link, (void __user *)arg, size))
return -EFAULT;
if (link.lk_fast_rate < 9600)
link.lk_fast_rate = 9600;
if (link.lk_slow_rate < 2400)
link.lk_slow_rate = 2400;
if (link.lk_fast_rate > 10000000)
link.lk_fast_rate = 10000000;
if (link.lk_slow_rate > link.lk_fast_rate)
link.lk_slow_rate = link.lk_fast_rate;
if (link.lk_fast_delay > 2000)
link.lk_fast_delay = 2000;
if (link.lk_slow_delay > 10000)
link.lk_slow_delay = 10000;
if (link.lk_fast_delay < 60)
link.lk_fast_delay = 60;
if (link.lk_slow_delay < link.lk_fast_delay)
link.lk_slow_delay = link.lk_fast_delay;
if (link.lk_header_size < 2)
link.lk_header_size = 2;
if (link.lk_header_size > 128)
link.lk_header_size = 128;
link.lk_fast_rate /= 8 * 1000 / dgrp_poll_tick;
link.lk_slow_rate /= 8 * 1000 / dgrp_poll_tick;
link.lk_fast_delay /= dgrp_poll_tick;
link.lk_slow_delay /= dgrp_poll_tick;
nd->nd_link = link;
break;
case DIGI_GETLINK:
if (size != sizeof(struct link_struct))
return -EINVAL;
if (copy_to_user((void __user *)arg, (void *)(&nd->nd_link),
size))
return -EFAULT;
break;
default:
return -EINVAL;
}
return 0;
}
/**
* dgrp_poll_handler() -- handler for poll timer
*
* As each timer expires, it determines (a) whether the "transmit"
* waiter needs to be woken up, and (b) whether the poller needs to
* be rescheduled.
*/
void dgrp_poll_handler(unsigned long arg)
{
struct dgrp_poll_data *poll_data;
struct nd_struct *nd;
struct link_struct *lk;
ulong time;
ulong poll_time;
ulong freq;
ulong lock_flags;
poll_data = (struct dgrp_poll_data *) arg;
freq = 1000 / poll_data->poll_tick;
poll_data->poll_round += 17;
if (poll_data->poll_round >= freq)
poll_data->poll_round -= freq;
/*
* Loop to process all open nodes.
*
* For each node, determine the rate at which it should
* be transmitting data. Then if the node should wake up
* and transmit data now, enable the net receive select
* to get the transmit going.
*/
list_for_each_entry(nd, &nd_struct_list, list) {
lk = &nd->nd_link;
/*
* Decrement statistics. These are only for use with
* KME, so don't worry that the operations are done
* unlocked, and so the results are occasionally wrong.
*/
nd->nd_read_count -= (nd->nd_read_count +
poll_data->poll_round) / freq;
nd->nd_write_count -= (nd->nd_write_count +
poll_data->poll_round) / freq;
nd->nd_send_count -= (nd->nd_send_count +
poll_data->poll_round) / freq;
nd->nd_tx_byte -= (nd->nd_tx_byte +
poll_data->poll_round) / freq;
nd->nd_rx_byte -= (nd->nd_rx_byte +
poll_data->poll_round) / freq;
/*
* Wake the daemon to transmit data only when there is
* enough byte credit to send data.
*
* The results are approximate because the operations
* are performed unlocked, and we are inspecting
* data asynchronously updated elsewhere. The whole
* thing is just approximation anyway, so that should
* be okay.
*/
if (lk->lk_slow_rate >= UIO_MAX) {
nd->nd_delay = 0;
nd->nd_rate = UIO_MAX;
nd->nd_tx_deposit = nd->nd_tx_charge + 3 * UIO_MAX;
nd->nd_tx_credit = 3 * UIO_MAX;
} else {
long rate;
long delay;
long deposit;
long charge;
long size;
long excess;
long seq_in = nd->nd_seq_in;
long seq_out = nd->nd_seq_out;
/*
* If there are no outstanding packets, run at the
* fastest rate.
*/
if (seq_in == seq_out) {
delay = 0;
rate = lk->lk_fast_rate;
}
/*
* Otherwise compute the transmit rate based on the
* delay since the oldest packet.
*/
else {
/*
* The actual delay is computed as the
* time since the oldest unacknowledged
* packet was sent, minus the time it
* took to send that packet to the server.
*/
delay = ((jiffies - nd->nd_seq_time[seq_out])
- (nd->nd_seq_size[seq_out] /
lk->lk_fast_rate));
/*
* If the delay is less than the "fast"
* delay, transmit full speed. If greater
* than the "slow" delay, transmit at the
* "slow" speed. In between, interpolate
* between the fast and slow speeds.
*/
rate =
(delay <= lk->lk_fast_delay ?
lk->lk_fast_rate :
delay >= lk->lk_slow_delay ?
lk->lk_slow_rate :
(lk->lk_slow_rate +
(lk->lk_slow_delay - delay) *
(lk->lk_fast_rate - lk->lk_slow_rate) /
(lk->lk_slow_delay - lk->lk_fast_delay)
)
);
}
nd->nd_delay = delay;
nd->nd_rate = rate;
/*
* Increase the transmit credit by depositing the
* current transmit rate.
*/
deposit = nd->nd_tx_deposit;
charge = nd->nd_tx_charge;
deposit += rate;
/*
* If the available transmit credit becomes too large,
* reduce the deposit to correct the value.
*
* Too large is the max of:
* 6 times the header size
* 3 times the current transmit rate.
*/
size = 2 * nd->nd_link.lk_header_size;
if (size < rate)
size = rate;
size *= 3;
excess = deposit - charge - size;
if (excess > 0)
deposit -= excess;
nd->nd_tx_deposit = deposit;
nd->nd_tx_credit = deposit - charge;
/*
* Wake the transmit task only if the transmit credit
* is at least 3 times the transmit header size.
*/
size = 3 * lk->lk_header_size;
if (nd->nd_tx_credit < size)
continue;
}
/*
* Enable the READ select to wake the daemon if there
* is useful work for the drp_read routine to perform.
*/
if (waitqueue_active(&nd->nd_tx_waitq) &&
(nd->nd_tx_work != 0 ||
(ulong)(jiffies - nd->nd_tx_time) >= IDLE_MAX)) {
nd->nd_tx_ready = 1;
wake_up_interruptible(&nd->nd_tx_waitq);
/* not needed */
/* nd->nd_flag &= ~ND_SELECT; */
}
}
/*
* Schedule ourself back at the nominal wakeup interval.
*/
spin_lock_irqsave(&poll_data->poll_lock, lock_flags);
poll_data->node_active_count--;
if (poll_data->node_active_count > 0) {
poll_data->node_active_count++;
poll_time = poll_data->timer.expires +
poll_data->poll_tick * HZ / 1000;
time = poll_time - jiffies;
if (time >= 2 * poll_data->poll_tick)
poll_time = jiffies + dgrp_poll_tick * HZ / 1000;
poll_data->timer.expires = poll_time;
add_timer(&poll_data->timer);
}
spin_unlock_irqrestore(&poll_data->poll_lock, lock_flags);
}
