| /***************************************************************************** |
| * |
| * 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_mon_ops.c |
| * |
| * Description: |
| * |
| * Handle the file operations required for the "monitor" devices. |
| * Includes those functions required to register the "mon" devices |
| * in "/proc". |
| * |
| * Author: |
| * |
| * James A. Puzzo |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/tty.h> |
| #include <linux/sched.h> |
| #include <asm/unaligned.h> |
| #include <linux/slab.h> |
| #include <linux/proc_fs.h> |
| #include <linux/uaccess.h> |
| |
| #include "dgrp_common.h" |
| |
| /* File operation declarations */ |
| static int dgrp_mon_open(struct inode *, struct file *); |
| static int dgrp_mon_release(struct inode *, struct file *); |
| static ssize_t dgrp_mon_read(struct file *, char __user *, size_t, loff_t *); |
| static long dgrp_mon_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg); |
| |
| const struct file_operations dgrp_mon_ops = { |
| .owner = THIS_MODULE, |
| .read = dgrp_mon_read, |
| .unlocked_ioctl = dgrp_mon_ioctl, |
| .open = dgrp_mon_open, |
| .release = dgrp_mon_release, |
| }; |
| |
| /** |
| * dgrp_mon_open() -- open /proc/dgrp/ports device for a PortServer |
| * @inode: struct inode * |
| * @file: struct file * |
| * |
| * Open function to open the /proc/dgrp/ports device for a PortServer. |
| */ |
| static int dgrp_mon_open(struct inode *inode, struct file *file) |
| { |
| struct nd_struct *nd; |
| struct timeval tv; |
| uint32_t time; |
| u8 *buf; |
| int rtn; |
| |
| rtn = try_module_get(THIS_MODULE); |
| if (!rtn) |
| return -ENXIO; |
| |
| rtn = 0; |
| |
| 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; |
| |
| /* |
| * Allocate the monitor buffer. |
| */ |
| |
| /* |
| * Grab the MON lock. |
| */ |
| down(&nd->nd_mon_semaphore); |
| |
| if (nd->nd_mon_buf) { |
| rtn = -EBUSY; |
| goto done_up; |
| } |
| |
| nd->nd_mon_buf = kmalloc(MON_MAX, GFP_KERNEL); |
| |
| if (!nd->nd_mon_buf) { |
| rtn = -ENOMEM; |
| goto done_up; |
| } |
| |
| /* |
| * Enter an RPDUMP file header into the buffer. |
| */ |
| |
| buf = nd->nd_mon_buf; |
| |
| strcpy(buf, RPDUMP_MAGIC); |
| buf += strlen(buf) + 1; |
| |
| do_gettimeofday(&tv); |
| |
| /* |
| * tv.tv_sec might be a 64 bit quantity. Pare |
| * it down to 32 bits before attempting to encode |
| * it. |
| */ |
| time = (uint32_t) (tv.tv_sec & 0xffffffff); |
| |
| put_unaligned_be32(time, buf); |
| put_unaligned_be16(0, buf + 4); |
| buf += 6; |
| |
| if (nd->nd_tx_module) { |
| buf[0] = RPDUMP_CLIENT; |
| put_unaligned_be32(0, buf + 1); |
| put_unaligned_be16(1, buf + 5); |
| buf[7] = 0xf0 + nd->nd_tx_module; |
| buf += 8; |
| } |
| |
| if (nd->nd_rx_module) { |
| buf[0] = RPDUMP_SERVER; |
| put_unaligned_be32(0, buf + 1); |
| put_unaligned_be16(1, buf + 5); |
| buf[7] = 0xf0 + nd->nd_rx_module; |
| buf += 8; |
| } |
| |
| nd->nd_mon_out = 0; |
| nd->nd_mon_in = buf - nd->nd_mon_buf; |
| nd->nd_mon_lbolt = jiffies; |
| |
| done_up: |
| up(&nd->nd_mon_semaphore); |
| |
| done: |
| if (rtn) |
| module_put(THIS_MODULE); |
| return rtn; |
| } |
| |
| |
| /** |
| * dgrp_mon_release() - Close the MON device for a particular PortServer |
| * @inode: struct inode * |
| * @file: struct file * |
| */ |
| static int dgrp_mon_release(struct inode *inode, struct file *file) |
| { |
| struct nd_struct *nd; |
| |
| /* |
| * Get the node pointer, and quit if it doesn't exist. |
| */ |
| nd = (struct nd_struct *)(file->private_data); |
| if (!nd) |
| goto done; |
| |
| /* |
| * Free the monitor buffer. |
| */ |
| |
| down(&nd->nd_mon_semaphore); |
| |
| kfree(nd->nd_mon_buf); |
| nd->nd_mon_buf = NULL; |
| nd->nd_mon_out = nd->nd_mon_in; |
| |
| /* |
| * Wakeup any thread waiting for buffer space. |
| */ |
| |
| if (nd->nd_mon_flag & MON_WAIT_SPACE) { |
| nd->nd_mon_flag &= ~MON_WAIT_SPACE; |
| wake_up_interruptible(&nd->nd_mon_wqueue); |
| } |
| |
| up(&nd->nd_mon_semaphore); |
| |
| /* |
| * Make sure there is no thread in the middle of writing a packet. |
| */ |
| down(&nd->nd_net_semaphore); |
| up(&nd->nd_net_semaphore); |
| |
| done: |
| module_put(THIS_MODULE); |
| file->private_data = NULL; |
| return 0; |
| } |
| |
| /** |
| * dgrp_mon_read() -- Copy data from the monitoring buffer to the user |
| */ |
| static ssize_t dgrp_mon_read(struct file *file, char __user *buf, size_t count, |
| loff_t *ppos) |
| { |
| struct nd_struct *nd; |
| int r; |
| int offset = 0; |
| int res = 0; |
| 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; |
| |
| /* |
| * Wait for some data to appear in the buffer. |
| */ |
| |
| down(&nd->nd_mon_semaphore); |
| |
| for (;;) { |
| res = (nd->nd_mon_in - nd->nd_mon_out) & MON_MASK; |
| |
| if (res) |
| break; |
| |
| nd->nd_mon_flag |= MON_WAIT_DATA; |
| |
| 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_DATA) == 0)); |
| |
| if (rtn) |
| return rtn; |
| |
| down(&nd->nd_mon_semaphore); |
| } |
| |
| /* |
| * Read whatever is there. |
| */ |
| |
| if (res > count) |
| res = count; |
| |
| r = MON_MAX - nd->nd_mon_out; |
| |
| if (r <= res) { |
| rtn = copy_to_user((void __user *)buf, |
| nd->nd_mon_buf + nd->nd_mon_out, r); |
| if (rtn) { |
| up(&nd->nd_mon_semaphore); |
| return -EFAULT; |
| } |
| |
| nd->nd_mon_out = 0; |
| res -= r; |
| offset = r; |
| } |
| |
| rtn = copy_to_user((void __user *) buf + offset, |
| nd->nd_mon_buf + nd->nd_mon_out, res); |
| if (rtn) { |
| up(&nd->nd_mon_semaphore); |
| return -EFAULT; |
| } |
| |
| nd->nd_mon_out += res; |
| |
| *ppos += res; |
| |
| up(&nd->nd_mon_semaphore); |
| |
| /* |
| * Wakeup any thread waiting for buffer space. |
| */ |
| |
| if (nd->nd_mon_flag & MON_WAIT_SPACE) { |
| nd->nd_mon_flag &= ~MON_WAIT_SPACE; |
| wake_up_interruptible(&nd->nd_mon_wqueue); |
| } |
| |
| return res; |
| } |
| |
| /* ioctl is not valid on monitor device */ |
| static long dgrp_mon_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| return -EINVAL; |
| } |