/***************************************************************************** * * Copyright 1999 Digi International (www.digi.com) * James Puzzo * * 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 #include #include #include #include #include #include #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; }