source: umon/main/common/tfsapi.c @ 87db514

/**************************************************************************
 *
 * Copyright (c) 2013 Alcatel-Lucent
 * 
 * Alcatel Lucent licenses this file to You under the Apache License,
 * Version 2.0 (the "License"); you may not use this file except in
 * compliance with the License.  A copy of the License is contained the
 * file LICENSE at the top level of this repository.
 * You may also obtain a copy of the License at:
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 **************************************************************************
 *
 * tfsapi.c:
 *
 * This file contains the portion of TFS that provides the function-level
 * API to the application.  If this is not being used by the application
 * then it can be omitted from the monitor build.
 * Note that not all of the api-specific code is here; some of it is in
 * tfs.c.  This is because the the MicroMonitor uses some of the api itself,
 * so it cannot be omitted from the TFS package without screwing up some 
 * other monitor functionality that needs it.
 *
 * Original author:     Ed Sutter (ed.sutter@alcatel-lucent.com)
 *
 */
#include "config.h"
#include "cpu.h"
#include "stddefs.h"
#include "genlib.h"
#include "tfs.h"
#include "tfsprivate.h"
#if INCLUDE_TFSAPI

/* tfstruncate():
 *      To support the ability to truncate a file (make it smaller); this
 *      function allows the user to adjust the high-water point of the currently
 *      opened (and assumed to be opened for modification) file and replaces
 *      that with the incoming argument.  This replacement is only done if the
 *      current high-water point is higher than the incoming length.
 *      MONLIB NOTICE: this function is accessible through monlib.c.
 */
int
tfstruncate(int fd, long len)
{
        struct tfsdat *tdat;

        if (tfsTrace > 1)
                printf("tfstruncate(%d,%ld)\n",fd,len);

        /* Verify valid range of incoming file descriptor. */
        if ((fd < 0) || (fd >= TFS_MAXOPEN))
                return(TFSERR_BADFD);

        tdat = &tfsSlots[fd];

        /* Make sure the file pointed to by the incoming descriptor is active
         * and that the incoming length is greater than the current high-water
         * point...
         */
        if (tdat->offset == -1)
                return(TFSERR_BADFD);
        if (len > tdat->hwp)
                return(TFSERR_BADARG);

        /* Make the adjustment... */
        tdat->hwp = len;
        return(TFS_OKAY);
}

/* tfseof():
 *      Return 1 if at the end of the file, else 0 if not at end; else negative
 *      if error.
 *      MONLIB NOTICE: this function is accessible through monlib.c.
 */
int
tfseof(int fd)
{
        struct tfsdat *tdat;

        /* Verify valid range of incoming file descriptor. */
        if ((fd < 0) || (fd >= TFS_MAXOPEN))
                return(TFSERR_BADARG);

        tdat = &tfsSlots[fd];

        /* Make sure the file pointed to by the incoming descriptor is active. */
        if (tdat->offset == -1)
                return(TFSERR_BADFD);

        if (tdat->offset >= tdat->hdr.filsize)
                return(1);
        else
                return(0);
}

/* tfsread():
 *      Similar to a standard read call to a file.
 *      MONLIB NOTICE: this function is accessible through monlib.c.
 */
int
tfsread(int fd, char *buf, int cnt)
{
        struct tfsdat *tdat;
        uchar *from;

        if (tfsTrace > 1)
                printf("tfsread(%d,0x%lx,%d)\n",fd,(ulong)buf,cnt);

        /* Verify valid range of incoming file descriptor. */
        if ((cnt < 1) || (fd < 0) || (fd >= TFS_MAXOPEN))
                return(TFSERR_BADARG);

        tdat = &tfsSlots[fd];

        /* Make sure the file pointed to by the incoming descriptor is active. */
        if (tdat->offset == -1)
                return(TFSERR_BADFD);

        if (tdat->offset >= tdat->hdr.filsize)
                return(TFSERR_EOF);

        from = (uchar *) tdat->base + tdat->offset;

        /* If request size is within the range of the file and current
         * then copy the data to the requestors buffer, increment offset 
         * and return the count.
         */
        if ((tdat->offset + cnt) <= tdat->hdr.filsize) {
                if (s_memcpy((char *)buf, (char *)from, cnt,0,0) != 0)
                        return(TFSERR_MEMFAIL);
        }
        /* If request size goes beyond the size of the file, then copy
         * to the end of the file and return that smaller count.
         */
        else {
                cnt = tdat->hdr.filsize - tdat->offset;
                if (s_memcpy((char *)buf, (char *)from, cnt, 0, 0) != 0)
                        return(TFSERR_MEMFAIL);
        }
        tdat->offset += cnt;
        return(cnt);
}

/* tfswrite():
 *      Similar to a standard write call to a file.
 *      MONLIB NOTICE: this function is accessible through monlib.c.
 */
int
tfswrite(int fd, char *buf, int cnt)
{
        struct tfsdat *tdat;

        if (tfsTrace > 1)
                printf("tfswrite(%d,0x%lx,%d)\n", fd,(ulong)buf,cnt);

        /* Verify valid range of incoming file descriptor. */
        if ((cnt < 1) || (fd < 0) || (fd >= TFS_MAXOPEN))
                return(TFSERR_BADARG);

        /* Make sure the file pointed to by the incoming descriptor is active. */
        if (tfsSlots[fd].offset == -1)
                return(TFSERR_BADARG);

        tdat = &tfsSlots[fd];

        /* Make sure file is not opened as read-only */
        if (tdat->flagmode & TFS_RDONLY)
                return(TFSERR_RDONLY);

        if (s_memcpy((char *)tdat->base+tdat->offset,(char *)buf,cnt,0,0) != 0)
                return(TFSERR_MEMFAIL);

        tdat->offset += cnt;

        /* If new offset is greater than current high-water point, then
         * adjust the high water point so that it is always reflecting the
         * highest offset into which the file has had some data written.
         */
        if (tdat->offset > tdat->hwp)
                tdat->hwp = tdat->offset;

        return(TFS_OKAY);
}

/* tfsseek():
 *      Adjust the current pointer into the specified file.
 *      If file is read-only, then the offset cannot exceed the file size;
 *      otherwise, the only check made to the offset is that it is positive.
 *      MONLIB NOTICE: this function is accessible through monlib.c.
 */
int
tfsseek(int fd, int offset, int whence)
{
        int     o_offset;
        struct tfsdat *tdat;

        if (tfsTrace > 1)
                printf("tfsseek(%d,%d,%d)\n",fd,offset,whence);

        if ((fd < 0) || (fd >= TFS_MAXOPEN))
                return(TFSERR_BADARG);

        tdat = &tfsSlots[fd];
        o_offset = tdat->offset;

        switch (whence) {
                case TFS_BEGIN:
                        tdat->offset = offset;
                        break;
                case TFS_CURRENT:
                        tdat->offset += offset;
                        break;
                default:
                        return(TFSERR_BADARG);
        }

        /* If new offset is less than zero or if the file is read-only and the
         * new offset is greater than the file size, return EOF...
         */
        if ((tdat->offset < 0) ||
                ((tdat->flagmode & TFS_RDONLY) && (tdat->offset > tdat->hdr.filsize))){
                tdat->offset = o_offset;
                return(TFSERR_EOF);
        }
        return(tdat->offset);
}

/* tfsipmod():
 *      Modify "in-place" a portion of a file in TFS.
 *      This is a cheap and dirty way to modify a file...
 *      The idea is that a file is created with a lot of writeable flash space
 *      (data = 0xff).  This function can then be called to immediately modify
 *      blocks of space in that flash.  It will not do any tfsunlink/tfsadd, and
 *      it doesn't even require a tfsopen() tfsclose() wrapper.  Its a fast and
 *      efficient way to modify flash in the file system.
 *      Arguments:
 *      name    =       name of the file to be in-place-modified;
 *      buf             =       new data to be written to flash;
 *      offset  =       offset into file into which new data is to be written;
 *      size    =       size of new data (in bytes).
 *      
 *      With offset of -1, set offset to location containing first 0xff value.
 *      MONLIB NOTICE: this function is accessible through monlib.c.
 */
int
tfsipmod(char *name,char *buf,int offset,int size)
{
        int             rc;
        TFILE   *fp;
        uchar   *cp;

        fp = tfsstat(name);
        if (!fp)
                return (TFSERR_NOFILE);
        if (!(fp->flags & TFS_IPMOD))
                return(TFSERR_NOTIPMOD);
        
        if (offset == -1) {
                cp = (uchar *)(TFS_BASE(fp));
                for (offset=0;offset<fp->filsize;offset++,cp++) {
                        if (*cp == 0xff)
                                break;
                }
        }
        else if (offset < -1)
                return(TFSERR_BADARG);
        
        if ((offset + size) > fp->filsize)
                return(TFSERR_WRITEMAX);
        
        /* BUG fixed: 2/21/2001:
         * The (ulong *) cast was done prior to adding offset to the base.
         * This caused the offset to be quadrupled.
         */
        rc = tfsflashwrite((uchar *)(TFS_BASE(fp)+offset),(uchar *)buf,size);
        if (rc != TFS_OKAY)
                return(rc);

        tfslog(TFSLOG_IPM,name);
        return(TFS_OKAY);
}

/* tfsopen():
 *      Open a file for reading or creation.  If file is opened for writing,
 *      then the caller must provide a RAM buffer  pointer to be used for
 *      the file storage until it is transferred to flash by tfsclose().
 *      Note that the "buf" pointer is only needed for opening a file for
 *      creation or append (writing).
 *      MONLIB NOTICE: this function is accessible through monlib.c.
 */
int
tfsopen(char *file,long flagmode,char *buf)
{
        register int i;
        int             errno, retval;
        long    fmode;
        TFILE   *fp;
        struct  tfsdat *slot;

        errno = TFS_OKAY;

        fmode = flagmode & (TFS_RDONLY | TFS_APPEND | TFS_CREATE | TFS_CREATERM);

        /* See if file exists... */
        fp = tfsstat(file);

        /* If file exists, do a crc32 on the data.
         * If the file is in-place-modifiable, then the only legal flagmode
         * is TFS_RDONLY.  Plus, in this case, the crc32 test is skipped.
         */
        if (fp) {
                if (!((fmode == TFS_RDONLY) && (fp->flags & TFS_IPMOD))) {
                        if (crc32((unsigned char *)TFS_BASE(fp),fp->filsize) != fp->filcrc) {
                                retval = TFSERR_BADCRC;
                                goto done;
                        }
                }
        }

        /* This switch verifies...
         * - that the file exists if TFS_RDONLY or TFS_APPEND
         * - that the file does not exist if TFS_CREATE
         */
        switch(fmode) {
        case TFS_RDONLY:        /* Read existing file only, no change to file at all. */
                if (!fp) {
                        if (_tfsstat(file,0))
                                errno = TFSERR_LINKERROR;
                        else
                        errno = TFSERR_NOFILE;
                }
                else {
                        if ((fp->flags & TFS_UNREAD) && (TFS_USRLVL(fp) > getUsrLvl()))
                                errno = TFSERR_USERDENIED;
                }
                break;
        case TFS_APPEND:        /* Append to the end of the current file. */
                if (!fp)
                        errno = TFSERR_NOFILE;
                else {
                        if (TFS_USRLVL(fp) > getUsrLvl())
                                errno = TFSERR_USERDENIED;
                }
                break;
        case TFS_CREATERM:              /* Create a new file, allow tfsadd() to remove */
                fmode = TFS_CREATE;     /* it if it exists. */
                break;          
        case TFS_CREATE:        /* Create a new file, error if it exists. */
                if (fp)
                        errno = TFSERR_FILEEXISTS;
                break;
        case (TFS_APPEND|TFS_CREATE):   /* If both mode bits are set, clear one */
                if (fp) {                                       /* based on the presence of the file. */
                        if (TFS_USRLVL(fp) > getUsrLvl())
                                errno = TFSERR_USERDENIED;
                        fmode = TFS_APPEND;
                }
                else {
                        fmode = TFS_CREATE;
                }
                break;
        default:
                errno = TFSERR_BADARG;
                break;
        }

        if (errno != TFS_OKAY) {
                retval = errno;
                goto done;
        }

        /* Find an empty slot...
         */
        slot = tfsSlots;
        for (i=0;i<TFS_MAXOPEN;i++,slot++) {
                if (slot->offset == -1)
                        break;
        }

        /* Populate the slot structure if a slot is found to be
         * available...
         */
        if (i < TFS_MAXOPEN) {
                retval = i;
                slot->hwp = 0;
                slot->offset = 0;
                slot->flagmode = fmode;
                if (fmode & TFS_CREATE) {
                        strncpy(slot->hdr.name,file,TFSNAMESIZE);
                        slot->flagmode |= (flagmode & TFS_FLAGMASK);
                        slot->base = (uchar *)buf;
                }
                else if (fmode & TFS_APPEND) {
                        memcpy((char *)&slot->hdr,(char *)fp,sizeof(struct tfshdr));
                        if (s_memcpy((char *)buf,(char *)(TFS_BASE(fp)),
                                fp->filsize,0,0) != 0) {
                                retval = TFSERR_MEMFAIL;
                                goto done;
                        }
                        slot->flagmode = fp->flags;
                        slot->flagmode |= TFS_APPEND;
                        slot->base = (uchar *)buf;
                        slot->hwp = fp->filsize;
                        slot->offset = fp->filsize;
                }
                else {
                        slot->base = (uchar *) (TFS_BASE(fp));
                        memcpy((char *)&slot->hdr,(char *)fp,sizeof(struct tfshdr));
                }
        }
        else {
                retval = TFSERR_NOSLOT;
        }

done:           
        if (tfsTrace > 0)
                printf("tfsopen(%s,0x%lx,0x%lx)=%d\n",file,flagmode,(ulong)buf,retval);

        return(retval);
}

/* tfsclose():
 *      If the file was opened for reading only, then just close out the 
 *      entry in the tfsSlots table.  If the file was opened for creation,
 *      then add it to the tfs list.  Note the additional argument is
 *      only needed for tfsclose() of a newly created file.
 *      info  = additional text describing the file.
 *      MONLIB NOTICE: this function is accessible through monlib.c.
 */
int
tfsclose(int fd,char *info)
{
        int             err;
        struct tfsdat *tdat;

        if (!info) info = "";

        if (tfsTrace > 0)
                printf("tfsclose(%d,%s)\n",fd,info);

        if ((fd < 0) || (fd >= TFS_MAXOPEN))
                return(TFSERR_BADARG);

        tdat = &tfsSlots[fd];

        if (tdat->offset == -1)
                return(TFSERR_BADFD);

        /* Mark the file as closed by setting the offset to -1.
         * Note that this is done prior to potentially calling tfsadd() so
         * that tfsadd() will not think the file is opened and reject the add...
         */
        tdat->offset = -1;

        /* If the file was opened for creation or append, and the hwp
         * (high-water-point) is greater than zero, then add it now.
         *
         * Note regarding hwp==0...
         * In cases where a non-existent file is opened for creation,
         * but then nothing is written to the file, the hwp value will
         * be zero; hence, no need to call tfsadd().
         */
        if ((tdat->flagmode & (TFS_CREATE | TFS_APPEND)) && (tdat->hwp > 0)) {
                char    buf[16];

                err = tfsadd(tdat->hdr.name, info, tfsflagsbtoa(tdat->flagmode,buf),
                        tdat->base, tdat->hwp);
                if (err != TFS_OKAY) {
                        printf("%s: %s\n",tdat->hdr.name,tfserrmsg(err));
                        return(err);
                }
        }
        return(TFS_OKAY);
}

#else /* INCLUDE_TFSAPI */

int
tfstruncate(int fd, long len)
{
        return(TFSERR_NOTAVAILABLE);
}

int
tfseof(int fd)
{
        return(TFSERR_NOTAVAILABLE);
}

int
tfsread(int fd, char *buf, int cnt)
{
        return(TFSERR_NOTAVAILABLE);
}

int
tfswrite(int fd, char *buf, int cnt)
{
        return(TFSERR_NOTAVAILABLE);
}

int
tfsseek(int fd, int offset, int whence)
{
        return(TFSERR_NOTAVAILABLE);
}

int
tfsopen(char *file,long flagmode,char *buf)
{
        return(TFSERR_NOTAVAILABLE);
}

int
tfsclose(int fd,char *info)
{
        return(TFSERR_NOTAVAILABLE);
}

int
tfsipmod(char *name,char *buf,int offset,int size)
{
        return(TFSERR_NOTAVAILABLE);
}

#endif  /* INCLUDE_TFSAPI else */

#if INCLUDE_TFSAPI || INCLUDE_TFSSCRIPT

/* tfsgetline():
 *      Read into the buffer a block of characters upto the next EOL delimiter
 *      the file.  After the EOL, or after max-1 chars are loaded, terminate
 *      with a NULL.  Return the number of characters loaded.
 *      At end of file return 0.
 *      MONLIB NOTICE: this function is accessible through monlib.c.
 */
int
tfsgetline(int fd,char *buf,int max)
{
        uchar   *from;
        int             tot, rtot;
        struct  tfsdat *tdat;
        volatile char   *to;

        max--;

        if (tfsTrace > 1)
                printf("tfsgetline(%d,0x%lx,%d)\n",fd,(ulong)buf,max);

        /* Verify valid range of incoming file descriptor. */
        if ((max < 1) || (fd < 0) || (fd >= TFS_MAXOPEN))
                return(TFSERR_BADARG);

        /* Make sure the file pointed to by the incoming descriptor is active. */
        if (tfsSlots[fd].offset == -1)
                return(TFSERR_BADARG);

        tdat = &tfsSlots[fd];

        if (tdat->offset == -1)
                return(TFSERR_BADFD);

        if (tdat->offset >= tdat->hdr.filsize)
                return(0);

        from = (uchar *) tdat->base + tdat->offset;
        to = buf;

        /* If the incoming buffer size is larger than needed, adjust the
         * 'max' value so that we don't pass the end of the file...
         */
        if ((tdat->offset + max) > tdat->hdr.filsize) 
                max = tdat->hdr.filsize - tdat->offset + 1;

        /* Read from the file data area until newline (0x0a) is found 
         * (or until the 'max buffer space' value is reached).
         * Strip 0x0d (if present) and terminate with NULL  in all cases.  
         */
        for(rtot=0,tot=0;tot < max; from++) {
                /* Terminate on Ctrl-Z, non-ASCII, Newline or NULL.
                 * Ignore carriage return completely...
                 */
                if ((*from == 0x1a) || (*from > 0x7f) || (*from == 0))          
                        break;

                tot++;

                if (*from == 0x0d) 
                        continue;

                *to = *from;
                if (*to != *from)
                        return(TFSERR_MEMFAIL);

                to++; rtot++;

                if (*from == 0x0a)
                        break;
        }
        *to = 0;

        tdat->offset += tot;
        return(rtot);
}

#else

int
tfsgetline(int fd,char *buf,int max)
{
        return(TFSERR_NOTAVAILABLE);
}

#endif