hysdn_procconf.c

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/* $Id: hysdn_procconf.c,v 1.8.6.4 2001/09/23 22:24:54 kai Exp $
 *
 * Linux driver for HYSDN cards, /proc/net filesystem dir and conf functions.
 *
 * written by Werner Cornelius ([email protected]) for Hypercope GmbH
 *
 * Copyright 1999  by Werner Cornelius ([email protected])
 *
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 *
 */

#include <linux/cred.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <net/net_namespace.h>

#include "hysdn_defs.h"

static DEFINE_MUTEX(hysdn_conf_mutex);

#define INFO_OUT_LEN 80     /* length of info line including lf */

/********************************************************/
/* defines and data structure for conf write operations */
/********************************************************/
#define CONF_STATE_DETECT 0 /* waiting for detect */
#define CONF_STATE_CONF   1 /* writing config data */
#define CONF_STATE_POF    2 /* writing pof data */
#define CONF_LINE_LEN   255 /* 255 chars max */

struct conf_writedata {
    hysdn_card *card;   /* card the device is connected to */
    int buf_size;       /* actual number of bytes in the buffer */
    int needed_size;    /* needed size when reading pof */
    int state;      /* actual interface states from above constants */
    unsigned char conf_line[CONF_LINE_LEN]; /* buffered conf line */
    unsigned short channel;     /* active channel number */
    unsigned char *pof_buffer;  /* buffer when writing pof */
};

/***********************************************************************/
/* process_line parses one config line and transfers it to the card if */
/* necessary.                                                          */
/* if the return value is negative an error occurred.                   */
/***********************************************************************/
static int
process_line(struct conf_writedata *cnf)
{
    unsigned char *cp = cnf->conf_line;
    int i;

    if (cnf->card->debug_flags & LOG_CNF_LINE)
        hysdn_addlog(cnf->card, "conf line: %s", cp);

    if (*cp == '-') {   /* option */
        cp++;       /* point to option char */

        if (*cp++ != 'c')
            return (0); /* option unknown or used */
        i = 0;      /* start value for channel */
        while ((*cp <= '9') && (*cp >= '0'))
            i = i * 10 + *cp++ - '0';   /* get decimal number */
        if (i > 65535) {
            if (cnf->card->debug_flags & LOG_CNF_MISC)
                hysdn_addlog(cnf->card, "conf channel invalid  %d", i);
            return (-ERR_INV_CHAN);     /* invalid channel */
        }
        cnf->channel = i & 0xFFFF;  /* set new channel number */
        return (0); /* success */
    }           /* option */
    if (*cp == '*') {   /* line to send */
        if (cnf->card->debug_flags & LOG_CNF_DATA)
            hysdn_addlog(cnf->card, "conf chan=%d %s", cnf->channel, cp);
        return (hysdn_tx_cfgline(cnf->card, cnf->conf_line + 1,
                     cnf->channel));    /* send the line without * */
    }           /* line to send */
    return (0);
}               /* process_line */

/***********************************/
/* conf file operations and tables */
/***********************************/

/****************************************************/
/* write conf file -> boot or send cfg line to card */
/****************************************************/
static ssize_t
hysdn_conf_write(struct file *file, const char __user *buf, size_t count, loff_t *off)
{
    struct conf_writedata *cnf;
    int i;
    unsigned char ch, *cp;

    if (!count)
        return (0); /* nothing to handle */

    if (!(cnf = file->private_data))
        return (-EFAULT);   /* should never happen */

    if (cnf->state == CONF_STATE_DETECT) {  /* auto detect cnf or pof data */
        if (copy_from_user(&ch, buf, 1))    /* get first char for detect */
            return (-EFAULT);

        if (ch == 0x1A) {
            /* we detected a pof file */
            if ((cnf->needed_size = pof_write_open(cnf->card, &cnf->pof_buffer)) <= 0)
                return (cnf->needed_size);  /* an error occurred -> exit */
            cnf->buf_size = 0;  /* buffer is empty */
            cnf->state = CONF_STATE_POF;    /* new state */
        } else {
            /* conf data has been detected */
            cnf->buf_size = 0;  /* buffer is empty */
            cnf->state = CONF_STATE_CONF;   /* requested conf data write */
            if (cnf->card->state != CARD_STATE_RUN)
                return (-ERR_NOT_BOOTED);
            cnf->conf_line[CONF_LINE_LEN - 1] = 0;  /* limit string length */
            cnf->channel = 4098;    /* default channel for output */
        }
    }           /* state was auto detect */
    if (cnf->state == CONF_STATE_POF) { /* pof write active */
        i = cnf->needed_size - cnf->buf_size;   /* bytes still missing for write */
        if (i <= 0)
            return (-EINVAL);   /* size error handling pof */

        if (i < count)
            count = i;  /* limit requested number of bytes */
        if (copy_from_user(cnf->pof_buffer + cnf->buf_size, buf, count))
            return (-EFAULT);   /* error while copying */
        cnf->buf_size += count;

        if (cnf->needed_size == cnf->buf_size) {
            cnf->needed_size = pof_write_buffer(cnf->card, cnf->buf_size);  /* write data */
            if (cnf->needed_size <= 0) {
                cnf->card->state = CARD_STATE_BOOTERR;  /* show boot error */
                return (cnf->needed_size);  /* an error occurred */
            }
            cnf->buf_size = 0;  /* buffer is empty again */
        }
    }
    /* pof write active */
    else {          /* conf write active */

        if (cnf->card->state != CARD_STATE_RUN) {
            if (cnf->card->debug_flags & LOG_CNF_MISC)
                hysdn_addlog(cnf->card, "cnf write denied -> not booted");
            return (-ERR_NOT_BOOTED);
        }
        i = (CONF_LINE_LEN - 1) - cnf->buf_size;    /* bytes available in buffer */
        if (i > 0) {
            /* copy remaining bytes into buffer */

            if (count > i)
                count = i;  /* limit transfer */
            if (copy_from_user(cnf->conf_line + cnf->buf_size, buf, count))
                return (-EFAULT);   /* error while copying */

            i = count;  /* number of chars in buffer */
            cp = cnf->conf_line + cnf->buf_size;
            while (i) {
                /* search for end of line */
                if ((*cp < ' ') && (*cp != 9))
                    break;  /* end of line found */
                cp++;
                i--;
            }   /* search for end of line */

            if (i) {
                /* delimiter found */
                *cp++ = 0;  /* string termination */
                count -= (i - 1);   /* subtract remaining bytes from count */
                while ((i) && (*cp < ' ') && (*cp != 9)) {
                    i--;    /* discard next char */
                    count++;    /* mark as read */
                    cp++;   /* next char */
                }
                cnf->buf_size = 0;  /* buffer is empty after transfer */
                if ((i = process_line(cnf)) < 0)    /* handle the line */
                    count = i;  /* return the error */
            }
            /* delimiter found */
            else {
                cnf->buf_size += count;     /* add chars to string */
                if (cnf->buf_size >= CONF_LINE_LEN - 1) {
                    if (cnf->card->debug_flags & LOG_CNF_MISC)
                        hysdn_addlog(cnf->card, "cnf line too long %d chars pos %d", cnf->buf_size, count);
                    return (-ERR_CONF_LONG);
                }
            }   /* not delimited */

        }
        /* copy remaining bytes into buffer */
        else {
            if (cnf->card->debug_flags & LOG_CNF_MISC)
                hysdn_addlog(cnf->card, "cnf line too long");
            return (-ERR_CONF_LONG);
        }
    }           /* conf write active */

    return (count);
}               /* hysdn_conf_write */

/*******************************************/
/* read conf file -> output card info data */
/*******************************************/
static ssize_t
hysdn_conf_read(struct file *file, char __user *buf, size_t count, loff_t *off)
{
    char *cp;

    if (!(file->f_mode & FMODE_READ))
        return -EPERM;  /* no permission to read */

    if (!(cp = file->private_data))
        return -EFAULT; /* should never happen */

    return simple_read_from_buffer(buf, count, off, cp, strlen(cp));
}               /* hysdn_conf_read */

/******************/
/* open conf file */
/******************/
static int
hysdn_conf_open(struct inode *ino, struct file *filep)
{
    hysdn_card *card;
    struct proc_dir_entry *pd;
    struct conf_writedata *cnf;
    char *cp, *tmp;

    /* now search the addressed card */
    mutex_lock(&hysdn_conf_mutex);
    card = card_root;
    while (card) {
        pd = card->procconf;
        if (pd == PDE(ino))
            break;
        card = card->next;  /* search next entry */
    }
    if (!card) {
        mutex_unlock(&hysdn_conf_mutex);
        return (-ENODEV);   /* device is unknown/invalid */
    }
    if (card->debug_flags & (LOG_PROC_OPEN | LOG_PROC_ALL))
        hysdn_addlog(card, "config open for uid=%d gid=%d mode=0x%x",
                 filep->f_cred->fsuid, filep->f_cred->fsgid,
                 filep->f_mode);

    if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) {
        /* write only access -> write boot file or conf line */

        if (!(cnf = kmalloc(sizeof(struct conf_writedata), GFP_KERNEL))) {
            mutex_unlock(&hysdn_conf_mutex);
            return (-EFAULT);
        }
        cnf->card = card;
        cnf->buf_size = 0;  /* nothing buffered */
        cnf->state = CONF_STATE_DETECT;     /* start auto detect */
        filep->private_data = cnf;

    } else if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
        /* read access -> output card info data */

        if (!(tmp = kmalloc(INFO_OUT_LEN * 2 + 2, GFP_KERNEL))) {
            mutex_unlock(&hysdn_conf_mutex);
            return (-EFAULT);   /* out of memory */
        }
        filep->private_data = tmp;  /* start of string */

        /* first output a headline */
        sprintf(tmp, "id bus slot type irq iobase dp-mem     b-chans fax-chans state device");
        cp = tmp;   /* start of string */
        while (*cp)
            cp++;
        while (((cp - tmp) % (INFO_OUT_LEN + 1)) != INFO_OUT_LEN)
            *cp++ = ' ';
        *cp++ = '\n';

        /* and now the data */
        sprintf(cp, "%d  %3d %4d %4d %3d 0x%04x 0x%08lx %7d %9d %3d   %s",
            card->myid,
            card->bus,
            PCI_SLOT(card->devfn),
            card->brdtype,
            card->irq,
            card->iobase,
            card->membase,
            card->bchans,
            card->faxchans,
            card->state,
            hysdn_net_getname(card));
        while (*cp)
            cp++;
        while (((cp - tmp) % (INFO_OUT_LEN + 1)) != INFO_OUT_LEN)
            *cp++ = ' ';
        *cp++ = '\n';
        *cp = 0;    /* end of string */
    } else {        /* simultaneous read/write access forbidden ! */
        mutex_unlock(&hysdn_conf_mutex);
        return (-EPERM);    /* no permission this time */
    }
    mutex_unlock(&hysdn_conf_mutex);
    return nonseekable_open(ino, filep);
}               /* hysdn_conf_open */

/***************************/
/* close a config file.    */
/***************************/
static int
hysdn_conf_close(struct inode *ino, struct file *filep)
{
    hysdn_card *card;
    struct conf_writedata *cnf;
    int retval = 0;
    struct proc_dir_entry *pd;

    mutex_lock(&hysdn_conf_mutex);
    /* search the addressed card */
    card = card_root;
    while (card) {
        pd = card->procconf;
        if (pd == PDE(ino))
            break;
        card = card->next;  /* search next entry */
    }
    if (!card) {
        mutex_unlock(&hysdn_conf_mutex);
        return (-ENODEV);   /* device is unknown/invalid */
    }
    if (card->debug_flags & (LOG_PROC_OPEN | LOG_PROC_ALL))
        hysdn_addlog(card, "config close for uid=%d gid=%d mode=0x%x",
                 filep->f_cred->fsuid, filep->f_cred->fsgid,
                 filep->f_mode);

    if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) {
        /* write only access -> write boot file or conf line */
        if (filep->private_data) {
            cnf = filep->private_data;

            if (cnf->state == CONF_STATE_POF)
                retval = pof_write_close(cnf->card);    /* close the pof write */
            kfree(filep->private_data); /* free allocated memory for buffer */

        }       /* handle write private data */
    } else if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
        /* read access -> output card info data */

        kfree(filep->private_data); /* release memory */
    }
    mutex_unlock(&hysdn_conf_mutex);
    return (retval);
}               /* hysdn_conf_close */

/******************************************************/
/* table for conf filesystem functions defined above. */
/******************************************************/
static const struct file_operations conf_fops =
{
    .owner      = THIS_MODULE,
    .llseek         = no_llseek,
    .read           = hysdn_conf_read,
    .write          = hysdn_conf_write,
    .open           = hysdn_conf_open,
    .release        = hysdn_conf_close,
};

/*****************************/
/* hysdn subdir in /proc/net */
/*****************************/
struct proc_dir_entry *hysdn_proc_entry = NULL;

/*******************************************************************************/
/* hysdn_procconf_init is called when the module is loaded and after the cards */
/* have been detected. The needed proc dir and card config files are created.  */
/* The log init is called at last.                                             */
/*******************************************************************************/
int
hysdn_procconf_init(void)
{
    hysdn_card *card;
    unsigned char conf_name[20];

    hysdn_proc_entry = proc_mkdir(PROC_SUBDIR_NAME, init_net.proc_net);
    if (!hysdn_proc_entry) {
        printk(KERN_ERR "HYSDN: unable to create hysdn subdir\n");
        return (-1);
    }
    card = card_root;   /* point to first card */
    while (card) {

        sprintf(conf_name, "%s%d", PROC_CONF_BASENAME, card->myid);
        if ((card->procconf = (void *) proc_create(conf_name,
                               S_IFREG | S_IRUGO | S_IWUSR,
                               hysdn_proc_entry,
                               &conf_fops)) != NULL) {
            hysdn_proclog_init(card);   /* init the log file entry */
        }
        card = card->next;  /* next entry */
    }

    printk(KERN_NOTICE "HYSDN: procfs initialised\n");
    return (0);
}               /* hysdn_procconf_init */

/*************************************************************************************/
/* hysdn_procconf_release is called when the module is unloaded and before the cards */
/* resources are released. The module counter is assumed to be 0 !                   */
/*************************************************************************************/
void
hysdn_procconf_release(void)
{
    hysdn_card *card;
    unsigned char conf_name[20];

    card = card_root;   /* start with first card */
    while (card) {

        sprintf(conf_name, "%s%d", PROC_CONF_BASENAME, card->myid);
        if (card->procconf)
            remove_proc_entry(conf_name, hysdn_proc_entry);

        hysdn_proclog_release(card);    /* init the log file entry */

        card = card->next;  /* point to next card */
    }

    remove_proc_entry(PROC_SUBDIR_NAME, init_net.proc_net);
}