rfscontrol.c

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/* rfscontrol.c - rfscontrol */

#include <xinu.h>

/*------------------------------------------------------------------------
 * rfscontrol  -  Provide control functions for the remote file system
 *------------------------------------------------------------------------
 */
devcall rfscontrol (
     struct dentry  *devptr,    /* Entry in device switch table */
     int32  func,           /* A control function       */
     int32  arg1,           /* Argument #1          */
     int32  arg2            /* Argument #2          */
    )
{
    int32   len;            /* Length of name       */
    struct  rf_msg_sreq msg;    /* Buffer for size request  */
    struct  rf_msg_sres resp;   /* Buffer for size response */
    char    *to, *from;     /* Used during name copy    */
    int32   retval;         /* Return value         */

    /* Wait for exclusive access */

    wait(Rf_data.rf_mutex);

    /* Check length of name (copy during the check even though the  */
    /*  copy is only used for a size request)           */

    from = (char *)arg1;
    to = msg.rf_name;
    len = 0;
    memset(to, NULLCH, RF_NAMLEN);  /* Start name as all zeroes */
    while ( (*to++ = *from++) ) {   /* Copy name to message     */
        len++;
        if (len >= (RF_NAMLEN - 1) ) {
            signal(Rf_data.rf_mutex);
            return SYSERR;
        }
    }

    switch (func) {

    /* Delete a file */

    case RFS_CTL_DEL:
        if (rfsndmsg(RF_MSG_DREQ, (char *)arg1) == SYSERR) {
            signal(Rf_data.rf_mutex);
            return SYSERR;
        }
        break;

    /* Truncate a file */

    case RFS_CTL_TRUNC:
        if (rfsndmsg(RF_MSG_TREQ, (char *)arg1) == SYSERR) {
            signal(Rf_data.rf_mutex);
            return SYSERR;
        }
        break;



    /* Make a directory */

    case RFS_CTL_MKDIR:
        if (rfsndmsg(RF_MSG_MREQ, (char *)arg1) == SYSERR) {
            signal(Rf_data.rf_mutex);
            return SYSERR;
        }
        break;

    /* Remove a directory */

    case RFS_CTL_RMDIR:
        if (rfsndmsg(RF_MSG_XREQ, (char *)arg1) == SYSERR) {
            signal(Rf_data.rf_mutex);
            return SYSERR;
        }
        break;

    /* Obtain current file size (cannot use rfsndmsg because a  */
    /*  response contains a value in addition to the header)    */

    case RFS_CTL_SIZE:

        /* Hand-craft a size request message */

        msg.rf_type = htons(RF_MSG_SREQ);
        msg.rf_status = htons(0);
        msg.rf_seq = 0;     /* Rfscomm will set the seq num */

        /* Send the request to server and obtain a response */

        retval = rfscomm( (struct rf_msg_hdr *)&msg,
                    sizeof(struct rf_msg_sreq),
                  (struct rf_msg_hdr *)&resp,
                    sizeof(struct rf_msg_sres) );
        if ( (retval == SYSERR) || (retval == TIMEOUT) ) {
            signal(Rf_data.rf_mutex);
            return SYSERR;
        } else {
            signal(Rf_data.rf_mutex);
            return ntohl(resp.rf_size);
        }

    default:
        kprintf("rfscontrol: function %d not valid\n", func);
        signal(Rf_data.rf_mutex);
        return SYSERR;
    }

    signal(Rf_data.rf_mutex);
    return OK;
}