/*
 * Copyright (c) 2000-2002, 2006 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: findfp.c,v 1.67 2006/08/28 21:24:46 ca Exp $")
#include <stdlib.h>
#include <unistd.h>
#include <sys/param.h>
#include <errno.h>
#include <string.h>
#include <syslog.h>
#include <sm/io.h>
#include <sm/assert.h>
#include <sm/heap.h>
#include <sm/string.h>
#include <sm/conf.h>
#include "local.h"
#include "glue.h"

bool    Sm_IO_DidInit;  /* IO system has been initialized? */

const char SmFileMagic[] = "sm_file";

/* An open type to map to fopen()-like behavior */
SM_FILE_T SmFtStdio_def =
    {SmFileMagic, 0, 0, 0, (SMRW|SMFBF), -1, {0, 0}, 0, 0, 0,
        sm_stdclose, sm_stdread, sm_stdseek, sm_stdwrite,
        sm_stdopen, sm_stdsetinfo, sm_stdgetinfo, SM_TIME_FOREVER,
        SM_TIME_BLOCK, "stdio" };

/* An open type to map to fdopen()-like behavior */
SM_FILE_T SmFtStdiofd_def =
    {SmFileMagic, 0, 0, 0, (SMRW|SMFBF), -1, {0, 0}, 0, 0, 0,
        sm_stdclose, sm_stdread, sm_stdseek, sm_stdwrite,
        sm_stdfdopen, sm_stdsetinfo, sm_stdgetinfo, SM_TIME_FOREVER,
        SM_TIME_BLOCK, "stdiofd" };

/* A string file type */
SM_FILE_T SmFtString_def =
    {SmFileMagic, 0, 0, 0, (SMRW|SMNBF), -1, {0, 0}, 0, 0, 0,
        sm_strclose, sm_strread, sm_strseek, sm_strwrite,
        sm_stropen, sm_strsetinfo, sm_strgetinfo, SM_TIME_FOREVER,
        SM_TIME_BLOCK, "string" };

#if 0
/* A file type for syslog communications */
SM_FILE_T SmFtSyslog_def =
    {SmFileMagic, 0, 0, 0, (SMRW|SMNBF), -1, {0, 0}, 0, 0, 0,
        sm_syslogclose, sm_syslogread, sm_syslogseek, sm_syslogwrite,
        sm_syslogopen, sm_syslogsetinfo, sm_sysloggetinfo, SM_TIME_FOREVER,
        SM_TIME_BLOCK, "syslog" };
#endif /* 0 */

#define NDYNAMIC 10             /* add ten more whenever necessary */

#define smio(flags, file, name)                                         \
    {SmFileMagic, 0, 0, 0, flags, file, {0}, 0, SmIoF+file, 0,          \
        sm_stdclose, sm_stdread, sm_stdseek, sm_stdwrite,               \
        sm_stdopen, sm_stdsetinfo, sm_stdgetinfo, SM_TIME_FOREVER,      \
        SM_TIME_BLOCK, name}

/* sm_magic p r w flags file bf lbfsize cookie ival */
#define smstd(flags, file, name)                                        \
    {SmFileMagic, 0, 0, 0, flags, -1, {0}, 0, 0, file,                  \
        sm_stdioclose, sm_stdioread, sm_stdioseek, sm_stdiowrite,       \
        sm_stdioopen, sm_stdiosetinfo, sm_stdiogetinfo, SM_TIME_FOREVER,\
        SM_TIME_BLOCK, name}

/* A file type for interfacing to stdio FILE* streams. */
SM_FILE_T SmFtRealStdio_def = smstd(SMRW|SMNBF, -1, "realstdio");

                                /* the usual - (stdin + stdout + stderr) */
static SM_FILE_T usual[SM_IO_OPEN_MAX - 3];
static struct sm_glue smuglue = { 0, SM_IO_OPEN_MAX - 3, usual };

/* List of builtin automagically already open file pointers */
SM_FILE_T SmIoF[6] =
{
        smio(SMRD|SMLBF, SMIOIN_FILENO, "smioin"),      /* smioin */
        smio(SMWR|SMLBF, SMIOOUT_FILENO, "smioout"),    /* smioout */
        smio(SMWR|SMNBF, SMIOERR_FILENO, "smioerr"),    /* smioerr */
        smstd(SMRD|SMNBF, SMIOIN_FILENO, "smiostdin"),  /* smiostdin */
        smstd(SMWR|SMNBF, SMIOOUT_FILENO, "smiostdout"),/* smiostdout */
        smstd(SMWR|SMNBF, SMIOERR_FILENO, "smiostderr") /* smiostderr */
};

/* Structure containing list of currently open file pointers */
struct sm_glue smglue = { &smuglue, 3, SmIoF };

/*
**  SM_MOREGLUE -- adds more space for open file pointers
**
**      Parameters:
**              n -- number of new spaces for file pointers
**
**      Returns:
**              Raises an exception if no more memory.
**              Otherwise, returns a pointer to new spaces.
*/

static struct sm_glue *sm_moreglue_x __P((int));
static SM_FILE_T empty;

static struct sm_glue *
sm_moreglue_x(n)
        register int n;
{
        register struct sm_glue *g;
        register SM_FILE_T *p;

        g = (struct sm_glue *) sm_pmalloc_x(sizeof(*g) + SM_ALIGN_BITS +
                                            n * sizeof(SM_FILE_T));
        p = (SM_FILE_T *) SM_ALIGN(g + 1);
        g->gl_next = NULL;
        g->gl_niobs = n;
        g->gl_iobs = p;
        while (--n >= 0)
                *p++ = empty;
        return g;
}

/*
**  SM_FP -- allocate and initialize an SM_FILE structure
**
**      Parameters:
**              t -- file type requested to be opened.
**              flags -- control flags for file type behavior
**              oldfp -- file pointer to reuse if available (optional)
**
**      Returns:
**              Raises exception on memory exhaustion.
**              Aborts if type is invalid.
**              Otherwise, returns file pointer for requested file type.
*/

SM_FILE_T *
sm_fp(t, flags, oldfp)
        const SM_FILE_T *t;
        const int flags;
        SM_FILE_T *oldfp;
{
        register SM_FILE_T *fp;
        register int n;
        register struct sm_glue *g;

        SM_REQUIRE(t->f_open && t->f_close && (t->f_read || t->f_write));

        if (!Sm_IO_DidInit)
                sm_init();

        if (oldfp != NULL)
        {
                fp = oldfp;
                goto found; /* for opening reusing an 'fp' */
        }

        for (g = &smglue;; g = g->gl_next)
        {
                for (fp = g->gl_iobs, n = g->gl_niobs; --n >= 0; fp++)
                        if (fp->sm_magic == NULL)
                                goto found;
                if (g->gl_next == NULL)
                        g->gl_next = sm_moreglue_x(NDYNAMIC);
        }
found:
        fp->sm_magic = SmFileMagic; /* 'fp' now valid and in-use */
        fp->f_p = NULL;         /* no current pointer */
        fp->f_w = 0;            /* nothing to write */
        fp->f_r = 0;            /* nothing to read */
        fp->f_flags = flags;
        fp->f_file = -1;                /* no file */
        fp->f_bf.smb_base = NULL;       /* no buffer */
        fp->f_bf.smb_size = 0;  /* no buffer size with no buffer */
        fp->f_lbfsize = 0;      /* not line buffered */
        fp->f_flushfp = NULL;   /* no associated flush file */

        fp->f_cookie = fp;      /* default: *open* overrides cookie setting */
        fp->f_close = t->f_close;       /* assign close function */
        fp->f_read = t->f_read;         /* assign read function */
        fp->f_seek = t->f_seek;         /* assign seek function */
        fp->f_write = t->f_write;       /* assign write function */
        fp->f_open = t->f_open;         /* assign open function */
        fp->f_setinfo = t->f_setinfo;   /* assign setinfo function */
        fp->f_getinfo = t->f_getinfo;   /* assign getinfo function */
        fp->f_type = t->f_type;         /* file type */

        fp->f_ub.smb_base = NULL;       /* no ungetc buffer */
        fp->f_ub.smb_size = 0;          /* no size for no ungetc buffer */

        if (fp->f_timeout == SM_TIME_DEFAULT)
                fp->f_timeout = SM_TIME_FOREVER;
        else
                fp->f_timeout = t->f_timeout; /* traditional behavior */
        fp->f_timeoutstate = SM_TIME_BLOCK; /* by default */

        return fp;
}

/*
**  SM_CLEANUP -- cleanup function when exit called.
**
**      This function is registered via atexit().
**
**      Parameters:
**              none
**
**      Returns:
**              nothing.
**
**      Side Effects:
**              flushes open files before they are forced closed
*/

void
sm_cleanup()
{
        int timeout = SM_TIME_DEFAULT;

        (void) sm_fwalk(sm_flush, &timeout); /* `cheating' */
}

/*
**  SM_INIT -- called whenever sm_io's internal variables must be set up.
**
**      Parameters:
**              none
**
**      Returns:
**              none
**
**      Side Effects:
**              Registers sm_cleanup() using atexit().
*/

void
sm_init()
{
        if (Sm_IO_DidInit)      /* paranoia */
                return;

        /* more paranoia: initialize pointers in a static variable */
        empty.f_type = NULL;
        empty.sm_magic = NULL;

        /* make sure we clean up on exit */
        atexit(sm_cleanup);             /* conservative */
        Sm_IO_DidInit = true;
}

/*
**  SM_IO_SETINFO -- change info for an open file type (fp)
**
**      The generic SM_IO_WHAT_VECTORS is auto supplied for all file types.
**      If the request is to set info other than SM_IO_WHAT_VECTORS then
**      the request is passed on to the file type's specific setinfo vector.
**      WARNING: this is working on an active/open file type.
**
**      Parameters:
**              fp -- file to make the setting on
**              what -- type of information to set
**              valp -- structure to obtain info from
**
**      Returns:
**              0 on success
**              -1 on error and sets errno:
**                      - when what != SM_IO_WHAT_VECTORS and setinfo vector
**                              not set
**                      - when vectored setinfo returns -1
*/

int
sm_io_setinfo(fp, what, valp)
        SM_FILE_T *fp;
        int what;
        void *valp;
{
        SM_FILE_T *v = (SM_FILE_T *) valp;

        SM_REQUIRE_ISA(fp, SmFileMagic);
        switch (what)
        {
          case SM_IO_WHAT_VECTORS:

                /*
                **  This is the "generic" available for all.
                **  This allows the function vectors to be replaced
                **  while the file type is active.
                */

                fp->f_close = v->f_close;
                fp->f_read = v->f_read;
                fp->f_seek = v->f_seek;
                fp->f_write = v->f_write;
                fp->f_open = v->f_open;
                fp->f_setinfo = v->f_setinfo;
                fp->f_getinfo = v->f_getinfo;
                sm_free(fp->f_type);
                fp->f_type = sm_strdup_x(v->f_type);
                return 0;
          case SM_IO_WHAT_TIMEOUT:
                fp->f_timeout = *((int *)valp);
                return 0;
        }

        /* Otherwise the vector will check it out */
        if (fp->f_setinfo == NULL)
        {
                errno = EINVAL;
                return -1;
        }
        else
                return (*fp->f_setinfo)(fp, what, valp);
}

/*
**  SM_IO_GETINFO -- get information for an active file type (fp)
**
**  This function supplies for all file types the answers for the
**              three requests SM_IO_WHAT_VECTORS, SM_IO_WHAT_TYPE and
**              SM_IO_WHAT_ISTYPE. Other requests are handled by the getinfo
**              vector if available for the open file type.
**      SM_IO_WHAT_VECTORS returns information for the file pointer vectors.
**      SM_IO_WHAT_TYPE returns the type identifier for the file pointer
**      SM_IO_WHAT_ISTYPE returns >0 if the passed in type matches the
**              file pointer's type.
**      SM_IO_IS_READABLE returns 1 if there is data available for reading,
**              0 otherwise.
**
**      Parameters:
**              fp -- file pointer for active file type
**              what -- type of information request
**              valp -- structure to place obtained info into
**
**      Returns:
**              -1 on error and sets errno:
**                      - when valp==NULL and request expects otherwise
**                      - when request is not SM_IO_WHAT_VECTORS and not
**                              SM_IO_WHAT_TYPE and not SM_IO_WHAT_ISTYPE
**                              and getinfo vector is NULL
**                      - when getinfo type vector returns -1
**              >=0 on success
*/

int
sm_io_getinfo(fp, what, valp)
        SM_FILE_T *fp;
        int what;
        void *valp;
{
        SM_FILE_T *v = (SM_FILE_T *) valp;

        SM_REQUIRE_ISA(fp, SmFileMagic);

        switch (what)
        {
          case SM_IO_WHAT_VECTORS:
                if (valp == NULL)
                {
                        errno = EINVAL;
                        return -1;
                }

                /* This is the "generic" available for all */
                v->f_close = fp->f_close;
                v->f_read = fp->f_read;
                v->f_seek = fp->f_seek;
                v->f_write = fp->f_write;
                v->f_open = fp->f_open;
                v->f_setinfo = fp->f_setinfo;
                v->f_getinfo = fp->f_getinfo;
                v->f_type = fp->f_type;
                return 0;

          case SM_IO_WHAT_TYPE:
                if (valp == NULL)
                {
                        errno = EINVAL;
                        return -1;
                }
                valp = sm_strdup_x(fp->f_type);
                return 0;

          case SM_IO_WHAT_ISTYPE:
                if (valp == NULL)
                {
                        errno = EINVAL;
                        return -1;
                }
                return strcmp(fp->f_type, valp) == 0;

          case SM_IO_IS_READABLE:

                /* if there is data in the buffer, it must be readable */
                if (fp->f_r > 0)
                        return 1;

                /* otherwise query the underlying file */
                break;

           case SM_IO_WHAT_TIMEOUT:
                *((int *) valp) = fp->f_timeout;
                return 0;

          case SM_IO_WHAT_FD:
                if (fp->f_file > -1)
                        return fp->f_file;

                /* try the file type specific getinfo to see if it knows */
                break;
        }

        /* Otherwise the vector will check it out */
        if (fp->f_getinfo == NULL)
        {
                errno = EINVAL;
                return -1;
        }
        return (*fp->f_getinfo)(fp, what, valp);
}