/*
 * Copyright (c) 2000-2005 Sendmail, Inc. and its suppliers.
 *      All rights reserved.
 * Copyright (c) 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * By using this file, you agree to the terms and conditions set
 * forth in the LICENSE file which can be found at the top level of
 * the sendmail distribution.
 */

#include <sm/gen.h>
SM_RCSID("@(#)$Id: stdio.c,v 1.71 2005/06/14 23:07:20 ca Exp $")
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>     /* FreeBSD: FD_ZERO needs <string.h> */
#include <sys/stat.h>
#include <sm/time.h>
#include <sm/heap.h>
#include <sm/assert.h>
#include <sm/varargs.h>
#include <sm/io.h>
#include <sm/setjmp.h>
#include <sm/conf.h>
#include <sm/fdset.h>
#include "local.h"

static int      sm_stdsetmode __P((SM_FILE_T *, const int *));
static int      sm_stdgetmode __P((SM_FILE_T *, int *));

/*
**  Overall:
**  Small standard I/O/seek/close functions.
**  These maintain the `known seek offset' for seek optimization.
*/

/*
**  SM_STDOPEN -- open a file with stdio behavior
**
**  Not associated with the system's stdio in libc.
**
**      Parameters:
**              fp -- file pointer to be associated with the open
**              info -- pathname of the file to be opened
**              flags -- indicates type of access methods
**              rpool -- ignored
**
**      Returns:
**              Failure: -1 and set errno
**              Success: 0 or greater (fd of file from open(2)).
**
*/

/* ARGSUSED3 */
int
sm_stdopen(fp, info, flags, rpool)
        SM_FILE_T *fp;
        const void *info;
        int flags;
        const void *rpool;
{
        char *path = (char *) info;
        int oflags;

        switch (SM_IO_MODE(flags))
        {
          case SM_IO_RDWR:
                oflags = O_RDWR;
                break;
          case SM_IO_RDWRTR:
                oflags = O_RDWR | O_CREAT | O_TRUNC;
                break;
          case SM_IO_RDONLY:
                oflags = O_RDONLY;
                break;
          case SM_IO_WRONLY:
                oflags = O_WRONLY | O_CREAT | O_TRUNC;
                break;
          case SM_IO_APPEND:
                oflags = O_APPEND | O_WRONLY | O_CREAT;
                break;
          case SM_IO_APPENDRW:
                oflags = O_APPEND | O_RDWR | O_CREAT;
                break;
          default:
                errno = EINVAL;
                return -1;
        }
#ifdef O_BINARY
        if (SM_IS_BINARY(flags))
                oflags |= O_BINARY;
#endif /* O_BINARY */
        fp->f_file = open(path, oflags,
                          S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
        if (fp->f_file < 0)
                return -1; /* errno set by open() */

        if (oflags & O_APPEND)
                (void) (*fp->f_seek)((void *)fp, (off_t)0, SEEK_END);

        return fp->f_file;
}

/*
**  SM_STDREAD -- read from the file
**
**      Parameters:
**              fp -- file pointer to read from
**              buf -- location to place read data
**              n -- number of bytes to read
**
**      Returns:
**              Failure: -1 and sets errno
**              Success: number of bytes read
**
**      Side Effects:
**              Updates internal offset into file.
*/

ssize_t
sm_stdread(fp, buf, n)
        SM_FILE_T *fp;
        char *buf;
        size_t n;
{
        register int ret;

        ret = read(fp->f_file, buf, n);

        /* if the read succeeded, update the current offset */
        if (ret > 0)
                fp->f_lseekoff += ret;
        return ret;
}

/*
**  SM_STDWRITE -- write to the file
**
**      Parameters:
**              fp -- file pointer ro write to
**              buf -- location of data to be written
**              n - number of bytes to write
**
**      Returns:
**              Failure: -1 and sets errno
**              Success: number of bytes written
*/

ssize_t
sm_stdwrite(fp, buf, n)
        SM_FILE_T *fp;
        char const *buf;
        size_t n;
{
        return write(fp->f_file, buf, n);
}

/*
**  SM_STDSEEK -- set the file offset position
**
**      Parmeters:
**              fp -- file pointer to position
**              offset -- how far to position from "base" (set by 'whence')
**              whence -- indicates where the "base" of the 'offset' to start
**
**      Results:
**              Failure: -1 and sets errno
**              Success: the current offset
**
**      Side Effects:
**              Updates the internal value of the offset.
*/

off_t
sm_stdseek(fp, offset, whence)
        SM_FILE_T *fp;
        off_t offset;
        int whence;
{
        register off_t ret;

        ret = lseek(fp->f_file, (off_t) offset, whence);
        if (ret != (off_t) -1)
                fp->f_lseekoff = ret;
        return ret;
}

/*
**  SM_STDCLOSE -- close the file
**
**      Parameters:
**              fp -- the file pointer to close
**
**      Returns:
**              Success: 0 (zero)
**              Failure: -1 and sets errno
*/

int
sm_stdclose(fp)
        SM_FILE_T *fp;
{
        return close(fp->f_file);
}

/*
**  SM_STDSETMODE -- set the access mode for the file
**
**  Called by sm_stdsetinfo().
**
**      Parameters:
**              fp -- file pointer
**              mode -- new mode to set the file access to
**
**      Results:
**              Success: 0 (zero);
**              Failure: -1 and sets errno
*/

static int
sm_stdsetmode(fp, mode)
        SM_FILE_T *fp;
        const int *mode;
{
        int flags = 0;

        switch (SM_IO_MODE(*mode))
        {
          case SM_IO_RDWR:
                flags |= SMRW;
                break;
          case SM_IO_RDONLY:
                flags |= SMRD;
                break;
          case SM_IO_WRONLY:
                flags |= SMWR;
                break;
          case SM_IO_APPEND:
          default:
                errno = EINVAL;
                return -1;
        }
        fp->f_flags = fp->f_flags & ~SMMODEMASK;
        fp->f_flags |= flags;
        return 0;
}

/*
**  SM_STDGETMODE -- for getinfo determine open mode
**
**  Called by sm_stdgetinfo().
**
**      Parameters:
**              fp -- the file mode being determined
**              mode -- internal mode to map to external value
**
**      Results:
**              Failure: -1 and sets errno
**              Success: external mode value
*/

static int
sm_stdgetmode(fp, mode)
        SM_FILE_T *fp;
        int *mode;
{
        switch (fp->f_flags & SMMODEMASK)
        {
          case SMRW:
                *mode = SM_IO_RDWR;
                break;
          case SMRD:
                *mode = SM_IO_RDONLY;
                break;
          case SMWR:
                *mode = SM_IO_WRONLY;
                break;
          default:
                errno = EINVAL;
                return -1;
        }
        return 0;
}

/*
**  SM_STDSETINFO -- set/modify information for a file
**
**      Parameters:
**              fp -- file to set info for
**              what -- type of info to set
**              valp -- location of data used for setting
**
**      Returns:
**              Failure: -1 and sets errno
**              Success: >=0
*/

int
sm_stdsetinfo(fp, what, valp)
        SM_FILE_T *fp;
        int what;
        void *valp;
{
        switch (what)
        {
          case SM_IO_WHAT_MODE:
                return sm_stdsetmode(fp, (const int *)valp);

          default:
                errno = EINVAL;
                return -1;
        }
}

/*
**  SM_GETINFO -- get information about the open file
**
**      Parameters:
**              fp -- file to get info for
**              what -- type of info to get
**              valp -- location to place found info
**
**      Returns:
**              Success: may or may not place info in 'valp' depending
**                      on 'what' value, and returns values >=0. Return
**                      value may be the obtained info
**              Failure: -1 and sets errno
*/

int
sm_stdgetinfo(fp, what, valp)
        SM_FILE_T *fp;
        int what;
        void *valp;
{
        switch (what)
        {
          case SM_IO_WHAT_MODE:
                return sm_stdgetmode(fp, (int *)valp);

          case SM_IO_WHAT_FD:
                return fp->f_file;

          case SM_IO_WHAT_SIZE:
          {
                  struct stat st;

                  if (fstat(fp->f_file, &st) == 0)
                          return st.st_size;
                  else
                          return -1;
          }

          case SM_IO_IS_READABLE:
          {
                  fd_set readfds;
                  struct timeval timeout;

                  if (SM_FD_SETSIZE > 0 && fp->f_file >= SM_FD_SETSIZE)
                  {
                          errno = EINVAL;
                          return -1;
                  }
                  FD_ZERO(&readfds);
                  SM_FD_SET(fp->f_file, &readfds);
                  timeout.tv_sec = 0;
                  timeout.tv_usec = 0;
                  if (select(fp->f_file + 1, FDSET_CAST &readfds,
                             NULL, NULL, &timeout) > 0 &&
                      SM_FD_ISSET(fp->f_file, &readfds))
                          return 1;
                  return 0;
          }

          default:
                errno = EINVAL;
                return -1;
        }
}

/*
**  SM_STDFDOPEN -- open file by primitive 'fd' rather than pathname
**
**      I/O function to handle fdopen() stdio equivalence. The rest of
**      the functions are the same as the sm_stdopen() above.
**
**      Parameters:
**              fp -- the file pointer to be associated with the open
**              name -- the primitive file descriptor for association
**              flags -- indicates type of access methods
**              rpool -- ignored
**
**      Results:
**              Success: primitive file descriptor value
**              Failure: -1 and sets errno
*/

/* ARGSUSED3 */
int
sm_stdfdopen(fp, info, flags, rpool)
        SM_FILE_T *fp;
        const void *info;
        int flags;
        const void *rpool;
{
        int oflags, tmp, fdflags, fd = *((int *) info);

        switch (SM_IO_MODE(flags))
        {
          case SM_IO_RDWR:
                oflags = O_RDWR | O_CREAT;
                break;
          case SM_IO_RDONLY:
                oflags = O_RDONLY;
                break;
          case SM_IO_WRONLY:
                oflags = O_WRONLY | O_CREAT | O_TRUNC;
                break;
          case SM_IO_APPEND:
                oflags = O_APPEND | O_WRONLY | O_CREAT;
                break;
          case SM_IO_APPENDRW:
                oflags = O_APPEND | O_RDWR | O_CREAT;
                break;
          default:
                errno = EINVAL;
                return -1;
        }
#ifdef O_BINARY
        if (SM_IS_BINARY(flags))
                oflags |= O_BINARY;
#endif /* O_BINARY */

        /* Make sure the mode the user wants is a subset of the actual mode. */
        if ((fdflags = fcntl(fd, F_GETFL, 0)) < 0)
                return -1;
        tmp = fdflags & O_ACCMODE;
        if (tmp != O_RDWR && (tmp != (oflags & O_ACCMODE)))
        {
                errno = EINVAL;
                return -1;
        }
        fp->f_file = fd;
        if (oflags & O_APPEND)
                (void) (*fp->f_seek)(fp, (off_t)0, SEEK_END);
        return fp->f_file;
}

/*
**  SM_IO_FOPEN -- open a file
**
**      Same interface and semantics as the open() system call,
**      except that it returns SM_FILE_T* instead of a file descriptor.
**
**      Parameters:
**              pathname -- path of file to open
**              flags -- flags controlling the open
**              ...  -- option "mode" for opening the file
**
**      Returns:
**              Raises an exception on heap exhaustion.
**              Returns NULL and sets errno if open() fails.
**              Returns an SM_FILE_T pointer on success.
*/

SM_FILE_T *
#if SM_VA_STD
sm_io_fopen(char *pathname, int flags, ...)
#else /* SM_VA_STD */
sm_io_fopen(pathname, flags, va_alist)
        char *pathname;
        int flags;
        va_dcl
#endif /* SM_VA_STD */
{
        MODE_T mode;
        SM_FILE_T *fp;
        int ioflags;

        if (flags & O_CREAT)
        {
                SM_VA_LOCAL_DECL

                SM_VA_START(ap, flags);
                mode = (MODE_T) SM_VA_ARG(ap, int);
                SM_VA_END(ap);
        }
        else
                mode = 0;

        switch (flags & O_ACCMODE)
        {
          case O_RDONLY:
                ioflags = SMRD;
                break;
          case O_WRONLY:
                ioflags = SMWR;
                break;
          case O_RDWR:
                ioflags = SMRW;
                break;
          default:
                sm_abort("sm_io_fopen: bad flags 0%o", flags);
        }

        fp = sm_fp(SmFtStdio, ioflags, NULL);
        fp->f_file = open(pathname, flags, mode);
        if (fp->f_file == -1)
        {
                fp->f_flags = 0;
                fp->sm_magic = NULL;
                return NULL;
        }
        return fp;
}