strio.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* Copyright (c) 2000-2002, 2004 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.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include "local.h"
/*
** Cookie structure for the "strio" file type
*/
struct sm_str_obj
{
char *strio_base;
char *strio_end;
int strio_flags;
const void *strio_rpool;
};
typedef struct sm_str_obj SM_STR_OBJ_T;
/*
** SM_STRGROW -- increase storage space for string
**
** Parameters:
** s -- current cookie
** size -- new storage size request
**
** Returns:
** true iff successful.
*/
static bool
sm_strgrow(s, size)
SM_STR_OBJ_T *s;
{
register void *p;
if (s->strio_size >= size)
return true;
if (p == NULL)
return false;
s->strio_base = p;
s->strio_size = size;
return true;
}
/*
** SM_STRREAD -- read a portion of the string
**
** Parameters:
** fp -- the file pointer
** buf -- location to place read data
** n -- number of bytes to read
**
** Returns:
** Failure: -1 and sets errno
** Success: >=0, number of bytes read
*/
char *buf;
size_t n;
{
int len;
{
return -1;
}
s->strio_offset += len;
return len;
}
/*
** SM_STRWRITE -- write a portion of the string
**
** Parameters:
** fp -- the file pointer
** buf -- location of data for writing
** n -- number of bytes to write
**
** Returns:
** Failure: -1 and sets errno
** Success: >=0, number of bytes written
*/
char const *buf;
size_t n;
{
{
return -1;
}
if (n + s->strio_offset > s->strio_size)
{
if (!sm_strgrow(s, n + s->strio_offset))
return 0;
}
s->strio_offset += n;
return n;
}
/*
** SM_STRSEEK -- position the offset pointer for the string
**
** Only SM_IO_SEEK_SET, SM_IO_SEEK_CUR and SM_IO_SEEK_END are valid
** values for whence.
**
** Parameters:
** fp -- the file pointer
** offset -- number of bytes offset from "base"
** whence -- determines "base" for 'offset'
**
** Returns:
** Failure: -1 and sets errno
** Success: >=0, number of bytes read
*/
int whence;
{
switch (whence)
{
case SM_IO_SEEK_SET:
break;
case SM_IO_SEEK_CUR:
break;
case SM_IO_SEEK_END:
ret = s->strio_size;
break;
default:
return -1;
}
return -1;
{
goto reseek;
/* errno set by sm_strgrow */
return -1;
}
return ret;
}
/*
** SM_STROPEN -- open a string file type
**
** Parameters:
** fp -- file pointer open to be associated with
** info -- initial contents (NULL for none)
** flags -- flags for methods of access (was mode)
** rpool -- resource pool to use memory from (if applicable)
**
** Results:
** Success: 0 (zero)
** Failure: -1 and sets errno
*/
int
const void *info;
int flags;
const void *rpool;
{
register SM_STR_OBJ_T *s;
#if SM_RPOOL
#else /* SM_RPOOL */
s = sm_malloc(sizeof(SM_STR_OBJ_T));
if (s == NULL)
return -1;
#endif /* SM_RPOOL */
s->strio_rpool = rpool;
s->strio_offset = 0;
s->strio_size = 0;
s->strio_base = NULL;
s->strio_end = 0;
switch (flags)
{
case SM_IO_RDWR:
s->strio_flags = SMRW;
break;
case SM_IO_RDONLY:
s->strio_flags = SMRD;
break;
case SM_IO_WRONLY:
s->strio_flags = SMWR;
break;
case SM_IO_APPEND:
if (s->strio_rpool == NULL)
sm_free(s);
return -1;
default:
if (s->strio_rpool == NULL)
sm_free(s);
return -1;
}
{
if (s->strio_base == NULL)
{
int save_errno = errno;
if (s->strio_rpool == NULL)
sm_free(s);
errno = save_errno;
return -1;
}
}
return 0;
}
/*
** SM_STRCLOSE -- close the string file type and free resources
**
** Parameters:
** fp -- file pointer
**
** Results:
** Success: 0 (zero)
*/
int
{
#if !SM_RPOOL
sm_free(s->strio_base);
s->strio_base = NULL;
#endif /* !SM_RPOOL */
return 0;
}
/*
** SM_STRSETMODE -- set mode info for the file
**
** Note: changing the mode can be a safe way to have the "parent"
** set up a string that the "child" is not to modify
**
** Parameters:
** fp -- the file pointer
** mode -- location of new mode to set
**
** Results:
** Success: 0 (zero)
** Failure: -1 and sets errno
*/
static int
const int *mode;
{
int flags;
switch (*mode)
{
case SM_IO_RDWR:
break;
case SM_IO_RDONLY:
break;
case SM_IO_WRONLY:
break;
case SM_IO_APPEND:
return -1;
default:
return -1;
}
s->strio_flags &= ~SMMODEMASK;
s->strio_flags |= flags;
return 0;
}
/*
** SM_STRGETMODE -- get mode info for the file
**
** Parameters:
** fp -- the file pointer
** mode -- location to store current mode
**
** Results:
** Success: 0 (zero)
** Failure: -1 and sets errno
*/
int
int *mode;
{
switch (s->strio_flags & SMMODEMASK)
{
case SMRW:
*mode = SM_IO_RDWR;
break;
case SMRD:
*mode = SM_IO_RDONLY;
break;
case SMWR:
*mode = SM_IO_WRONLY;
break;
default:
return -1;
}
return 0;
}
/*
** SM_STRSETINFO -- set info for the file
**
** Currently only SM_IO_WHAT_MODE is supported for 'what'.
**
** Parameters:
** fp -- the file pointer
** what -- type of information to set
** valp -- location to data for doing set
**
** Results:
** Failure: -1 and sets errno
** Success: sm_strsetmode() return [0 (zero)]
*/
int
int what;
void *valp;
{
switch(what)
{
case SM_IO_WHAT_MODE:
default:
return -1;
}
}
/*
** SM_STRGETINFO -- get info for the file
**
** Currently only SM_IO_WHAT_MODE is supported for 'what'.
**
** Parameters:
** fp -- the file pointer
** what -- type of information requested
** valp -- location to return information in
**
** Results:
** Failure: -1 and sets errno
** Success: sm_strgetmode() return [0 (zero)]
*/
int
int what;
void *valp;
{
switch(what)
{
case SM_IO_WHAT_MODE:
default:
return -1;
}
}
/*
** SM_STRIO_INIT -- initializes a write-only string type
**
** Original comments below. This function does not appear to be used anywhere.
** The same functionality can be done by changing the mode of the file.
** ------------
** sm_strio_init initializes an SM_FILE_T structure as a write-only file
** that writes into the specified buffer:
** - Use sm_io_putc, sm_io_fprintf, etc, to write into the buffer.
** Attempts to write more than size-1 characters into the buffer will fail
** silently (no error is reported).
** - Use sm_io_fflush to nul terminate the string in the buffer
** (the write pointer is not advanced).
** No memory is allocated either by sm_strio_init or by sm_io_{putc,write} etc.
**
** Parameters:
** fp -- file pointer
** buf -- memory location for stored data
** size -- size of 'buf'
**
** Results:
** none.
*/
void
char *buf;
{
}