/*
 * Copyright (c) 2000-2001, 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.
 */

#include <sm/gen.h>
SM_IDSTR(id, "@(#)$Id: vfscanf.c,v 1.54 2006/10/12 22:03:52 ca Exp $")

#include <ctype.h>
#include <stdlib.h>
#include <errno.h>
#include <setjmp.h>
#include <sm/time.h>
#include <sm/varargs.h>
#include <sm/config.h>
#include <sm/io.h>
#include <sm/signal.h>
#include <sm/clock.h>
#include <sm/string.h>
#include "local.h"

#define BUF             513     /* Maximum length of numeric string. */

/* Flags used during conversion. */
#define LONG            0x01    /* l: long or double */
#define SHORT           0x04    /* h: short */
#define QUAD            0x08    /* q: quad (same as ll) */
#define SUPPRESS        0x10    /* suppress assignment */
#define POINTER         0x20    /* weird %p pointer (`fake hex') */
#define NOSKIP          0x40    /* do not skip blanks */

/*
**  The following are used in numeric conversions only:
**  SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
**  SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
*/

#define SIGNOK          0x080   /* +/- is (still) legal */
#define NDIGITS         0x100   /* no digits detected */

#define DPTOK           0x200   /* (float) decimal point is still legal */
#define EXPOK           0x400   /* (float) exponent (e+3, etc) still legal */

#define PFXOK           0x200   /* 0x prefix is (still) legal */
#define NZDIGITS        0x400   /* no zero digits detected */

/* Conversion types. */
#define CT_CHAR         0       /* %c conversion */
#define CT_CCL          1       /* %[...] conversion */
#define CT_STRING       2       /* %s conversion */
#define CT_INT          3       /* integer, i.e., strtoll or strtoull */
#define CT_FLOAT        4       /* floating, i.e., strtod */

static void             scanalrm __P((int));
static unsigned char    *sm_sccl __P((char *, unsigned char *));
static jmp_buf          ScanTimeOut;

/*
**  SCANALRM -- handler when timeout activated for sm_io_vfscanf()
**
**  Returns flow of control to where setjmp(ScanTimeOut) was set.
**
**      Parameters:
**              sig -- unused
**
**      Returns:
**              does not return
**
**      Side Effects:
**              returns flow of control to setjmp(ScanTimeOut).
**
**      NOTE:   THIS CAN BE CALLED FROM A SIGNAL HANDLER.  DO NOT ADD
**              ANYTHING TO THIS ROUTINE UNLESS YOU KNOW WHAT YOU ARE
**              DOING.
*/

/* ARGSUSED0 */
static void
scanalrm(sig)
        int sig;
{
        longjmp(ScanTimeOut, 1);
}

/*
**  SM_VFSCANF -- convert input into data units
**
**      Parameters:
**              fp -- file pointer for input data
**              timeout -- time intvl allowed to complete (milliseconds)
**              fmt0 -- format for finding data units
**              ap -- vectors for memory location for storing data units
**
**      Results:
**              Success: number of data units assigned
**              Failure: SM_IO_EOF
*/

int
sm_vfscanf(fp, timeout, fmt0, ap)
        register SM_FILE_T *fp;
        int SM_NONVOLATILE timeout;
        char const *fmt0;
        va_list SM_NONVOLATILE ap;
{
        register unsigned char *SM_NONVOLATILE fmt = (unsigned char *) fmt0;
        register int c;         /* character from format, or conversion */
        register size_t width;  /* field width, or 0 */
        register char *p;       /* points into all kinds of strings */
        register int n;         /* handy integer */
        register int flags;     /* flags as defined above */
        register char *p0;      /* saves original value of p when necessary */
        int nassigned;          /* number of fields assigned */
        int nread;              /* number of characters consumed from fp */
        int base;               /* base argument to strtoll/strtoull */

        /* conversion function (strtoll/strtoull) */
        ULONGLONG_T (*ccfn) __P((const char *, char **, int));
        char ccltab[256];       /* character class table for %[...] */
        char buf[BUF];          /* buffer for numeric conversions */
        SM_EVENT *evt = NULL;

        /* `basefix' is used to avoid `if' tests in the integer scanner */
        static short basefix[17] =
                { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };

        if (timeout == SM_TIME_DEFAULT)
                timeout = fp->f_timeout;
        if (timeout == SM_TIME_IMMEDIATE)
        {
                /*
                **  Filling the buffer will take time and we are wanted to
                **  return immediately. So...
                */

                errno = EAGAIN;
                return SM_IO_EOF;
        }

        if (timeout != SM_TIME_FOREVER)
        {
                if (setjmp(ScanTimeOut) != 0)
                {
                        errno = EAGAIN;
                        return SM_IO_EOF;
                }

                evt = sm_seteventm(timeout, scanalrm, 0);
        }

        nassigned = 0;
        nread = 0;
        base = 0;               /* XXX just to keep gcc happy */
        ccfn = NULL;            /* XXX just to keep gcc happy */
        for (;;)
        {
                c = *fmt++;
                if (c == 0)
                {
                        if (evt != NULL)
                                sm_clrevent(evt); /*  undo our timeout */
                        return nassigned;
                }
                if (isspace(c))
                {
                        while ((fp->f_r > 0 || sm_refill(fp, SM_TIME_FOREVER)
                                                == 0) &&
                            isspace(*fp->f_p))
                                nread++, fp->f_r--, fp->f_p++;
                        continue;
                }
                if (c != '%')
                        goto literal;
                width = 0;
                flags = 0;

                /*
                **  switch on the format.  continue if done;
                **  break once format type is derived.
                */

again:          c = *fmt++;
                switch (c)
                {
                  case '%':
literal:
                        if (fp->f_r <= 0 && sm_refill(fp, SM_TIME_FOREVER))
                                goto input_failure;
                        if (*fp->f_p != c)
                                goto match_failure;
                        fp->f_r--, fp->f_p++;
                        nread++;
                        continue;

                  case '*':
                        flags |= SUPPRESS;
                        goto again;
                  case 'h':
                        flags |= SHORT;
                        goto again;
                  case 'l':
                        if (*fmt == 'l')
                        {
                                fmt++;
                                flags |= QUAD;
                        }
                        else
                        {
                                flags |= LONG;
                        }
                        goto again;
                  case 'q':
                        flags |= QUAD;
                        goto again;

                  case '0': case '1': case '2': case '3': case '4':
                  case '5': case '6': case '7': case '8': case '9':
                        width = width * 10 + c - '0';
                        goto again;

                /*
                **  Conversions.
                **  Those marked `compat' are for 4.[123]BSD compatibility.
                **
                **  (According to ANSI, E and X formats are supposed
                **  to the same as e and x.  Sorry about that.)
                */

                  case 'D':     /* compat */
                        flags |= LONG;
                        /* FALLTHROUGH */
                  case 'd':
                        c = CT_INT;
                        ccfn = (ULONGLONG_T (*)())sm_strtoll;
                        base = 10;
                        break;

                  case 'i':
                        c = CT_INT;
                        ccfn = (ULONGLONG_T (*)())sm_strtoll;
                        base = 0;
                        break;

                  case 'O':     /* compat */
                        flags |= LONG;
                        /* FALLTHROUGH */
                  case 'o':
                        c = CT_INT;
                        ccfn = sm_strtoull;
                        base = 8;
                        break;

                  case 'u':
                        c = CT_INT;
                        ccfn = sm_strtoull;
                        base = 10;
                        break;

                  case 'X':
                  case 'x':
                        flags |= PFXOK; /* enable 0x prefixing */
                        c = CT_INT;
                        ccfn = sm_strtoull;
                        base = 16;
                        break;

                  case 'E':
                  case 'G':
                  case 'e':
                  case 'f':
                  case 'g':
                        c = CT_FLOAT;
                        break;

                  case 's':
                        c = CT_STRING;
                        break;

                  case '[':
                        fmt = sm_sccl(ccltab, fmt);
                        flags |= NOSKIP;
                        c = CT_CCL;
                        break;

                  case 'c':
                        flags |= NOSKIP;
                        c = CT_CHAR;
                        break;

                  case 'p':     /* pointer format is like hex */
                        flags |= POINTER | PFXOK;
                        c = CT_INT;
                        ccfn = sm_strtoull;
                        base = 16;
                        break;

                  case 'n':
                        if (flags & SUPPRESS)   /* ??? */
                                continue;
                        if (flags & SHORT)
                                *SM_VA_ARG(ap, short *) = nread;
                        else if (flags & LONG)
                                *SM_VA_ARG(ap, long *) = nread;
                        else
                                *SM_VA_ARG(ap, int *) = nread;
                        continue;

                /* Disgusting backwards compatibility hacks.    XXX */
                  case '\0':    /* compat */
                        if (evt != NULL)
                                sm_clrevent(evt); /*  undo our timeout */
                        return SM_IO_EOF;

                  default:      /* compat */
                        if (isupper(c))
                                flags |= LONG;
                        c = CT_INT;
                        ccfn = (ULONGLONG_T (*)()) sm_strtoll;
                        base = 10;
                        break;
                }

                /* We have a conversion that requires input. */
                if (fp->f_r <= 0 && sm_refill(fp, SM_TIME_FOREVER))
                        goto input_failure;

                /*
                **  Consume leading white space, except for formats
                **  that suppress this.
                */

                if ((flags & NOSKIP) == 0)
                {
                        while (isspace(*fp->f_p))
                        {
                                nread++;
                                if (--fp->f_r > 0)
                                        fp->f_p++;
                                else if (sm_refill(fp, SM_TIME_FOREVER))
                                        goto input_failure;
                        }
                        /*
                        **  Note that there is at least one character in
                        **  the buffer, so conversions that do not set NOSKIP
                        **  can no longer result in an input failure.
                        */
                }

                /* Do the conversion. */
                switch (c)
                {
                  case CT_CHAR:
                        /* scan arbitrary characters (sets NOSKIP) */
                        if (width == 0)
                                width = 1;
                        if (flags & SUPPRESS)
                        {
                                size_t sum = 0;
                                for (;;)
                                {
                                        if ((size_t) (n = fp->f_r) < width)
                                        {
                                                sum += n;
                                                width -= n;
                                                fp->f_p += n;
                                                if (sm_refill(fp,
                                                              SM_TIME_FOREVER))
                                                {
                                                        if (sum == 0)
                                                                goto input_failure;
                                                        break;
                                                }
                                        }
                                        else
                                        {
                                                sum += width;
                                                fp->f_r -= width;
                                                fp->f_p += width;
                                                break;
                                        }
                                }
                                nread += sum;
                        }
                        else
                        {
                                size_t r;

                                r = sm_io_read(fp, SM_TIME_FOREVER,
                                                (void *) SM_VA_ARG(ap, char *),
                                                width);
                                if (r == 0)
                                        goto input_failure;
                                nread += r;
                                nassigned++;
                        }
                        break;

                  case CT_CCL:
                        /* scan a (nonempty) character class (sets NOSKIP) */
                        if (width == 0)
                                width = (size_t)~0;     /* `infinity' */

                        /* take only those things in the class */
                        if (flags & SUPPRESS)
                        {
                                n = 0;
                                while (ccltab[*fp->f_p] != '\0')
                                {
                                        n++, fp->f_r--, fp->f_p++;
                                        if (--width == 0)
                                                break;
                                        if (fp->f_r <= 0 &&
                                            sm_refill(fp, SM_TIME_FOREVER))
                                        {
                                                if (n == 0) /* XXX how? */
                                                        goto input_failure;
                                                break;
                                        }
                                }
                                if (n == 0)
                                        goto match_failure;
                        }
                        else
                        {
                                p0 = p = SM_VA_ARG(ap, char *);
                                while (ccltab[*fp->f_p] != '\0')
                                {
                                        fp->f_r--;
                                        *p++ = *fp->f_p++;
                                        if (--width == 0)
                                                break;
                                        if (fp->f_r <= 0 &&
                                            sm_refill(fp, SM_TIME_FOREVER))
                                        {
                                                if (p == p0)
                                                        goto input_failure;
                                                break;
                                        }
                                }
                                n = p - p0;
                                if (n == 0)
                                        goto match_failure;
                                *p = 0;
                                nassigned++;
                        }
                        nread += n;
                        break;

                  case CT_STRING:
                        /* like CCL, but zero-length string OK, & no NOSKIP */
                        if (width == 0)
                                width = (size_t)~0;
                        if (flags & SUPPRESS)
                        {
                                n = 0;
                                while (!isspace(*fp->f_p))
                                {
                                        n++, fp->f_r--, fp->f_p++;
                                        if (--width == 0)
                                                break;
                                        if (fp->f_r <= 0 &&
                                            sm_refill(fp, SM_TIME_FOREVER))
                                                break;
                                }
                                nread += n;
                        }
                        else
                        {
                                p0 = p = SM_VA_ARG(ap, char *);
                                while (!isspace(*fp->f_p))
                                {
                                        fp->f_r--;
                                        *p++ = *fp->f_p++;
                                        if (--width == 0)
                                                break;
                                        if (fp->f_r <= 0 &&
                                            sm_refill(fp, SM_TIME_FOREVER))
                                                break;
                                }
                                *p = 0;
                                nread += p - p0;
                                nassigned++;
                        }
                        continue;

                  case CT_INT:
                        /* scan an integer as if by strtoll/strtoull */
#if SM_CONF_BROKEN_SIZE_T
                        if (width == 0 || width > sizeof(buf) - 1)
                                width = sizeof(buf) - 1;
#else /* SM_CONF_BROKEN_SIZE_T */
                        /* size_t is unsigned, hence this optimisation */
                        if (--width > sizeof(buf) - 2)
                                width = sizeof(buf) - 2;
                        width++;
#endif /* SM_CONF_BROKEN_SIZE_T */
                        flags |= SIGNOK | NDIGITS | NZDIGITS;
                        for (p = buf; width > 0; width--)
                        {
                                c = *fp->f_p;

                                /*
                                **  Switch on the character; `goto ok'
                                **  if we accept it as a part of number.
                                */

                                switch (c)
                                {

                                /*
                                **  The digit 0 is always legal, but is
                                **  special.  For %i conversions, if no
                                **  digits (zero or nonzero) have been
                                **  scanned (only signs), we will have
                                **  base==0.  In that case, we should set
                                **  it to 8 and enable 0x prefixing.
                                **  Also, if we have not scanned zero digits
                                **  before this, do not turn off prefixing
                                **  (someone else will turn it off if we
                                **  have scanned any nonzero digits).
                                */

                                  case '0':
                                        if (base == 0)
                                        {
                                                base = 8;
                                                flags |= PFXOK;
                                        }
                                        if (flags & NZDIGITS)
                                            flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
                                        else
                                            flags &= ~(SIGNOK|PFXOK|NDIGITS);
                                        goto ok;

                                /* 1 through 7 always legal */
                                  case '1': case '2': case '3':
                                  case '4': case '5': case '6': case '7':
                                        base = basefix[base];
                                        flags &= ~(SIGNOK | PFXOK | NDIGITS);
                                        goto ok;

                                /* digits 8 and 9 ok iff decimal or hex */
                                  case '8': case '9':
                                        base = basefix[base];
                                        if (base <= 8)
                                                break;  /* not legal here */
                                        flags &= ~(SIGNOK | PFXOK | NDIGITS);
                                        goto ok;

                                /* letters ok iff hex */
                                  case 'A': case 'B': case 'C':
                                  case 'D': case 'E': case 'F':
                                  case 'a': case 'b': case 'c':
                                  case 'd': case 'e': case 'f':

                                        /* no need to fix base here */
                                        if (base <= 10)
                                                break;  /* not legal here */
                                        flags &= ~(SIGNOK | PFXOK | NDIGITS);
                                        goto ok;

                                /* sign ok only as first character */
                                  case '+': case '-':
                                        if (flags & SIGNOK)
                                        {
                                                flags &= ~SIGNOK;
                                                goto ok;
                                        }
                                        break;

                                /* x ok iff flag still set & 2nd char */
                                  case 'x': case 'X':
                                        if (flags & PFXOK && p == buf + 1)
                                        {
                                                base = 16;      /* if %i */
                                                flags &= ~PFXOK;
                                                goto ok;
                                        }
                                        break;
                                }

                                /*
                                **  If we got here, c is not a legal character
                                **  for a number.  Stop accumulating digits.
                                */

                                break;
                ok:
                                /* c is legal: store it and look at the next. */
                                *p++ = c;
                                if (--fp->f_r > 0)
                                        fp->f_p++;
                                else if (sm_refill(fp, SM_TIME_FOREVER))
                                        break;          /* SM_IO_EOF */
                        }

                        /*
                        **  If we had only a sign, it is no good; push
                        **  back the sign.  If the number ends in `x',
                        **  it was [sign] '0' 'x', so push back the x
                        **  and treat it as [sign] '0'.
                        */

                        if (flags & NDIGITS)
                        {
                                if (p > buf)
                                        (void) sm_io_ungetc(fp, SM_TIME_DEFAULT,
                                                            *(unsigned char *)--p);
                                goto match_failure;
                        }
                        c = ((unsigned char *)p)[-1];
                        if (c == 'x' || c == 'X')
                        {
                                --p;
                                (void) sm_io_ungetc(fp, SM_TIME_DEFAULT, c);
                        }
                        if ((flags & SUPPRESS) == 0)
                        {
                                ULONGLONG_T res;

                                *p = 0;
                                res = (*ccfn)(buf, (char **)NULL, base);
                                if (flags & POINTER)
                                        *SM_VA_ARG(ap, void **) =
                                            (void *)(long) res;
                                else if (flags & QUAD)
                                        *SM_VA_ARG(ap, LONGLONG_T *) = res;
                                else if (flags & LONG)
                                        *SM_VA_ARG(ap, long *) = res;
                                else if (flags & SHORT)
                                        *SM_VA_ARG(ap, short *) = res;
                                else
                                        *SM_VA_ARG(ap, int *) = res;
                                nassigned++;
                        }
                        nread += p - buf;
                        break;

                  case CT_FLOAT:
                        /* scan a floating point number as if by strtod */
                        if (width == 0 || width > sizeof(buf) - 1)
                                width = sizeof(buf) - 1;
                        flags |= SIGNOK | NDIGITS | DPTOK | EXPOK;
                        for (p = buf; width; width--)
                        {
                                c = *fp->f_p;

                                /*
                                **  This code mimicks the integer conversion
                                **  code, but is much simpler.
                                */

                                switch (c)
                                {

                                  case '0': case '1': case '2': case '3':
                                  case '4': case '5': case '6': case '7':
                                  case '8': case '9':
                                        flags &= ~(SIGNOK | NDIGITS);
                                        goto fok;

                                  case '+': case '-':
                                        if (flags & SIGNOK)
                                        {
                                                flags &= ~SIGNOK;
                                                goto fok;
                                        }
                                        break;
                                  case '.':
                                        if (flags & DPTOK)
                                        {
                                                flags &= ~(SIGNOK | DPTOK);
                                                goto fok;
                                        }
                                        break;
                                  case 'e': case 'E':

                                        /* no exponent without some digits */
                                        if ((flags&(NDIGITS|EXPOK)) == EXPOK)
                                        {
                                                flags =
                                                    (flags & ~(EXPOK|DPTOK)) |
                                                    SIGNOK | NDIGITS;
                                                goto fok;
                                        }
                                        break;
                                }
                                break;
                fok:
                                *p++ = c;
                                if (--fp->f_r > 0)
                                        fp->f_p++;
                                else if (sm_refill(fp, SM_TIME_FOREVER))
                                        break;  /* SM_IO_EOF */
                        }

                        /*
                        **  If no digits, might be missing exponent digits
                        **  (just give back the exponent) or might be missing
                        **  regular digits, but had sign and/or decimal point.
                        */

                        if (flags & NDIGITS)
                        {
                                if (flags & EXPOK)
                                {
                                        /* no digits at all */
                                        while (p > buf)
                                                (void) sm_io_ungetc(fp,
                                                             SM_TIME_DEFAULT,
                                                             *(unsigned char *)--p);
                                        goto match_failure;
                                }

                                /* just a bad exponent (e and maybe sign) */
                                c = *(unsigned char *) --p;
                                if (c != 'e' && c != 'E')
                                {
                                        (void) sm_io_ungetc(fp, SM_TIME_DEFAULT,
                                                            c); /* sign */
                                        c = *(unsigned char *)--p;
                                }
                                (void) sm_io_ungetc(fp, SM_TIME_DEFAULT, c);
                        }
                        if ((flags & SUPPRESS) == 0)
                        {
                                double res;

                                *p = 0;
                                res = strtod(buf, (char **) NULL);
                                if (flags & LONG)
                                        *SM_VA_ARG(ap, double *) = res;
                                else
                                        *SM_VA_ARG(ap, float *) = res;
                                nassigned++;
                        }
                        nread += p - buf;
                        break;
                }
        }
input_failure:
        if (evt != NULL)
                sm_clrevent(evt); /*  undo our timeout */
        return nassigned ? nassigned : -1;
match_failure:
        if (evt != NULL)
                sm_clrevent(evt); /*  undo our timeout */
        return nassigned;
}

/*
**  SM_SCCL -- sequenced character comparison list
**
**  Fill in the given table from the scanset at the given format
**  (just after `[').  Return a pointer to the character past the
**  closing `]'.  The table has a 1 wherever characters should be
**  considered part of the scanset.
**
**      Parameters:
**              tab -- array flagging "active" char's to match (returned)
**              fmt -- character list (within "[]")
**
**      Results:
*/

static unsigned char *
sm_sccl(tab, fmt)
        register char *tab;
        register unsigned char *fmt;
{
        register int c, n, v;

        /* first `clear' the whole table */
        c = *fmt++;             /* first char hat => negated scanset */
        if (c == '^')
        {
                v = 1;          /* default => accept */
                c = *fmt++;     /* get new first char */
        }
        else
                v = 0;          /* default => reject */

        /* should probably use memset here */
        for (n = 0; n < 256; n++)
                tab[n] = v;
        if (c == 0)
                return fmt - 1; /* format ended before closing ] */

        /*
        **  Now set the entries corresponding to the actual scanset
        **  to the opposite of the above.
        **
        **  The first character may be ']' (or '-') without being special;
        **  the last character may be '-'.
        */

        v = 1 - v;
        for (;;)
        {
                tab[c] = v;             /* take character c */
doswitch:
                n = *fmt++;             /* and examine the next */
                switch (n)
                {

                  case 0:                       /* format ended too soon */
                        return fmt - 1;

                  case '-':
                        /*
                        **  A scanset of the form
                        **      [01+-]
                        **  is defined as `the digit 0, the digit 1,
                        **  the character +, the character -', but
                        **  the effect of a scanset such as
                        **      [a-zA-Z0-9]
                        **  is implementation defined.  The V7 Unix
                        **  scanf treats `a-z' as `the letters a through
                        **  z', but treats `a-a' as `the letter a, the
                        **  character -, and the letter a'.
                        **
                        **  For compatibility, the `-' is not considerd
                        **  to define a range if the character following
                        **  it is either a close bracket (required by ANSI)
                        **  or is not numerically greater than the character
                        **  we just stored in the table (c).
                        */

                        n = *fmt;
                        if (n == ']' || n < c)
                        {
                                c = '-';
                                break;  /* resume the for(;;) */
                        }
                        fmt++;
                        do
                        {
                                /* fill in the range */
                                tab[++c] = v;
                        } while (c < n);
#if 1   /* XXX another disgusting compatibility hack */

                        /*
                        **  Alas, the V7 Unix scanf also treats formats
                        **  such as [a-c-e] as `the letters a through e'.
                        **  This too is permitted by the standard....
                        */

                        goto doswitch;
#else
                        c = *fmt++;
                        if (c == 0)
                                return fmt - 1;
                        if (c == ']')
                                return fmt;
                        break;
#endif

                  case ']':             /* end of scanset */
                        return fmt;

                  default:              /* just another character */
                        c = n;
                        break;
                }
        }
        /* NOTREACHED */
}