/src/postfix/postfix/src/util/mac_expand.c

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/*++
/* NAME
/*  mac_expand 3
/* SUMMARY
/*  attribute expansion
/* SYNOPSIS
/*  #include <mac_expand.h>
/*
/*  int mac_expand(result, pattern, flags, filter, lookup, context)
/*  VSTRING *result;
/*  const char *pattern;
/*  int flags;
/*  const char *filter;
/*  const char *lookup(const char *key, int mode, void *context)
/*  void *context;
/* AUXILIARY FUNCTIONS
/*  typedef MAC_EXP_OP_RES (*MAC_EXPAND_RELOP_FN) (
/*  const char *left,
/*  int tok_val,
/*  const char *rite)
/*
/*  void  mac_expand_add_relop(
/*  int *tok_list,
/*  const char *suffix,
/*  MAC_EXPAND_RELOP_FN relop_eval)
/*
/*  MAC_EXP_OP_RES mac_exp_op_res_bool[2];
/* DESCRIPTION
/*  This module implements parameter-less named attribute
/*  expansions, both conditional and unconditional. As of Postfix
/*  3.0 this code supports relational expression evaluation.
/*
/*  In this text, an attribute is considered "undefined" when its value
/*  is a null pointer.  Otherwise, the attribute is considered "defined"
/*  and is expected to have as value a null-terminated string.
/*
/*  In the text below, the legacy form $(...) is equivalent to
/*  ${...}. The legacy form $(...) may eventually disappear
/*  from documentation. In the text below, the name in $name
/*  and ${name...} must contain only characters from the set
/*  [a-zA-Z0-9_].
/*
/*  The following substitutions are supported:
/* .IP "$name, ${name}"
/*  Unconditional attribute-based substitution. The result is the
/*  named attribute value (empty if the attribute is not defined)
/*  after optional further named attribute substitution.
/* .IP "${name?text}, ${name?{text}}"
/*  Conditional attribute-based substitution. If the named attribute
/*  value is non-empty, the result is the given text, after
/*  named attribute expansion and relational expression evaluation.
/*  Otherwise, the result is empty.  Whitespace before or after
/*  {text} is ignored.
/* .IP "${name:text}, ${name:{text}}"
/*  Conditional attribute-based substitution. If the attribute
/*  value is empty or undefined, the expansion is the given
/*  text, after named attribute expansion and relational expression
/*  evaluation.  Otherwise, the result is empty.  Whitespace
/*  before or after {text} is ignored.
/* .IP "${name?{text1}:{text2}}, ${name?{text1}:text2}"
/*  Conditional attribute-based substitution. If the named attribute
/*  value is non-empty, the result is text1.  Otherwise, the
/*  result is text2. In both cases the result is subject to
/*  named attribute expansion and relational expression evaluation.
/*  Whitespace before or after {text1} or {text2} is ignored.
/* .IP "${{text1} == ${text2} ? {text3} : {text4}}"
/*  Relational expression-based substitution.  First, the content
/*  of {text1} and ${text2} is subjected to named attribute and
/*  relational expression-based substitution.  Next, the relational
/*  expression is evaluated. If it evaluates to "true", the
/*  result is the content of {text3}, otherwise it is the content
/*  of {text4}, after named attribute and relational expression-based
/*  substitution. In addition to ==, this supports !=, <, <=,
/*  >=, and >. Comparisons are numerical when both operands are
/*  all digits, otherwise the comparisons are lexicographical.
/*
/*  Arguments:
/* .IP result
/*  Storage for the result of expansion. By default, the result
/*  is truncated upon entry.
/* .IP pattern
/*  The string to be expanded.
/* .IP flags
/*  Bit-wise OR of zero or more of the following:
/* .RS
/* .IP MAC_EXP_FLAG_RECURSE
/*  Expand attributes in lookup results. This should never be
/*  done with data whose origin is untrusted.
/* .IP MAC_EXP_FLAG_APPEND
/*  Append text to the result buffer without truncating it.
/* .IP MAC_EXP_FLAG_SCAN
/*  Scan the input for named attributes, including named
/*  attributes in all conditional result values.  Do not expand
/*  named attributes, and do not truncate or write to the result
/*  argument.
/* .IP MAC_EXP_FLAG_PRINTABLE
/*  Use the printable() function instead of \fIfilter\fR.
/* .PP
/*  The constant MAC_EXP_FLAG_NONE specifies a manifest null value.
/* .RE
/* .IP filter
/*  A null pointer, or a null-terminated array of characters that
/*  are allowed to appear in an expansion. Illegal characters are
/*  replaced by underscores.
/* .IP lookup
/*  The attribute lookup routine. Arguments are: the attribute name,
/*  MAC_EXP_MODE_TEST to test the existence of the named attribute
/*  or MAC_EXP_MODE_USE to use the value of the named attribute,
/*  and the caller context that was given to mac_expand(). A null
/*  result value means that the requested attribute was not defined.
/* .IP context
/*  Caller context that is passed on to the attribute lookup routine.
/* .PP
/*  mac_expand_add_relop() registers a function that implements
/*  support for custom relational operators. Custom operator names
/*  such as "==xxx" have two parts: a prefix that is identical to
/*  a built-in operator such as "==", and an application-specified
/*  suffix such as "xxx".
/*
/*  Arguments:
/* .IP tok_list
/*  A null-terminated list of MAC_EXP_OP_TOK_* values that support
/*  the custom operator suffix.
/* .IP suffix
/*  A null-terminated alphanumeric string that specifies the custom
/*  operator suffix.
/* .IP relop_eval
/*  A function that compares two strings according to the
/*  MAC_EXP_OP_TOK_* value specified with the tok_val argument,
/*  and that returns non-zero if the custom operator evaluates to
/*  true, zero otherwise.
/*
/*  mac_exp_op_res_bool provides an array that converts a boolean
/*  value (0 or 1) to the corresponding MAX_EXP_OP_RES_TRUE or
/*  MAX_EXP_OP_RES_FALSE value.
/* DIAGNOSTICS
/*  Fatal errors: out of memory.  Warnings: syntax errors, unreasonable
/*  recursion depth.
/*
/*  The result value is the binary OR of zero or more of the following:
/* .IP MAC_PARSE_ERROR
/*  A syntax error was found in \fBpattern\fR, or some attribute had
/*  an unreasonable nesting depth.
/* .IP MAC_PARSE_UNDEF
/*  An attribute was expanded but its value was not defined.
/* SEE ALSO
/*  mac_parse(3) locate macro references in string.
/* LICENSE
/* .ad
/* .fi
/*  The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*  Wietse Venema
/*  IBM T.J. Watson Research
/*  P.O. Box 704
/*  Yorktown Heights, NY 10598, USA
/*
/*  Wietse Venema
/*  Google, Inc.
/*  111 8th Avenue
/*  New York, NY 10011, USA
/*--*/

/* System library. */

#include <sys_defs.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>

/* Utility library. */

#include <msg.h>
#include <htable.h>
#include <vstring.h>
#include <mymalloc.h>
#include <stringops.h>
#include <name_code.h>
#include <sane_strtol.h>
#include <mac_parse.h>
#include <mac_expand.h>

 /*
  * Simplifies the return of common relational operator results.
  */
MAC_EXP_OP_RES mac_exp_op_res_bool[2] = {
    MAC_EXP_OP_RES_FALSE,
    MAC_EXP_OP_RES_TRUE
};

 /*
  * Little helper structure.
  */
typedef struct {
    VSTRING *result;      /* result buffer */
    int     flags;      /* features */
    const char *filter;     /* character filter */
    MAC_EXP_LOOKUP_FN lookup;   /* lookup routine */
    void   *context;      /* caller context */
    int     status;     /* findings */
    int     level;      /* nesting level */
} MAC_EXP_CONTEXT;

 /*
  * Support for relational expressions.
  * 
  * As of Postfix 2.2, ${attr-name?result} or ${attr-name:result} return the
  * result respectively when the parameter value is non-empty, or when the
  * parameter value is undefined or empty; support for the ternary ?:
  * operator was anticipated, but not implemented for 10 years.
  * 
  * To make ${relational-expr?result} and ${relational-expr:result} work as
  * expected without breaking the way that ? and : work, relational
  * expressions evaluate to a non-empty or empty value. It does not matter
  * what non-empty value we use for TRUE. However we must not use the
  * undefined (null pointer) value for FALSE - that would raise the
  * MAC_PARSE_UNDEF flag.
  * 
  * The value of a relational expression can be exposed with ${relational-expr},
  * i.e. a relational expression that is not followed by ? or : conditional
  * expansion.
  */
#define MAC_EXP_BVAL_TRUE "true"
#define MAC_EXP_BVAL_FALSE  ""

 /*
  * Relational operators. The MAC_EXP_OP_TOK_* are defined in the header
  * file.
  */
#define MAC_EXP_OP_STR_EQ "=="
#define MAC_EXP_OP_STR_NE "!="
#define MAC_EXP_OP_STR_LT "<"
#define MAC_EXP_OP_STR_LE "<="
#define MAC_EXP_OP_STR_GE ">="
#define MAC_EXP_OP_STR_GT ">"
#define MAC_EXP_OP_STR_ANY  "\"" MAC_EXP_OP_STR_EQ \
        "\" or \"" MAC_EXP_OP_STR_NE "\"" \
        "\" or \"" MAC_EXP_OP_STR_LT "\"" \
        "\" or \"" MAC_EXP_OP_STR_LE "\"" \
        "\" or \"" MAC_EXP_OP_STR_GE "\"" \
        "\" or \"" MAC_EXP_OP_STR_GT "\""

static const NAME_CODE mac_exp_op_table[] =
{
    MAC_EXP_OP_STR_EQ, MAC_EXP_OP_TOK_EQ,
    MAC_EXP_OP_STR_NE, MAC_EXP_OP_TOK_NE,
    MAC_EXP_OP_STR_LT, MAC_EXP_OP_TOK_LT,
    MAC_EXP_OP_STR_LE, MAC_EXP_OP_TOK_LE,
    MAC_EXP_OP_STR_GE, MAC_EXP_OP_TOK_GE,
    MAC_EXP_OP_STR_GT, MAC_EXP_OP_TOK_GT,
    0, MAC_EXP_OP_TOK_NONE,
};

 /*
  * The whitespace separator set.
  */
#define MAC_EXP_WHITESPACE  CHARS_SPACE

 /*
  * Support for operator extensions.
  */
static HTABLE *mac_exp_ext_table;
static VSTRING *mac_exp_ext_key;

 /*
  * SLMs.
  */
#define STR(x)  vstring_str(x)

/* atol_or_die - convert or die */

static long atol_or_die(const char *strval)
{
    long    result;
    char   *remainder;

    result = sane_strtol(strval, &remainder, 10);
    if (*strval == 0 /* can't happen */ || *remainder != 0 || errno == ERANGE)
  msg_fatal("mac_exp_eval: bad conversion: %s", strval);
    return (result);
}

/* mac_exp_eval - evaluate binary expression */

static MAC_EXP_OP_RES mac_exp_eval(const char *left, int tok_val,
                   const char *rite)
{
    static const char myname[] = "mac_exp_eval";
    long    delta;

    /*
     * Numerical or string comparison.
     */
    if (alldig(left) && alldig(rite)) {
  delta = atol_or_die(left) - atol_or_die(rite);
    } else {
  delta = strcmp(left, rite);
    }
    switch (tok_val) {
    case MAC_EXP_OP_TOK_EQ:
  return (mac_exp_op_res_bool[delta == 0]);
    case MAC_EXP_OP_TOK_NE:
  return (mac_exp_op_res_bool[delta != 0]);
    case MAC_EXP_OP_TOK_LT:
  return (mac_exp_op_res_bool[delta < 0]);
    case MAC_EXP_OP_TOK_LE:
  return (mac_exp_op_res_bool[delta <= 0]);
    case MAC_EXP_OP_TOK_GE:
  return (mac_exp_op_res_bool[delta >= 0]);
    case MAC_EXP_OP_TOK_GT:
  return (mac_exp_op_res_bool[delta > 0]);
    default:
  msg_panic("%s: unknown operator: %d",
      myname, tok_val);
    }
}

/* mac_exp_parse_error - report parse error, set error flag, return status */

static int PRINTFLIKE(2, 3) mac_exp_parse_error(MAC_EXP_CONTEXT *mc,
                    const char *fmt,...)
{
    va_list ap;

    va_start(ap, fmt);
    vmsg_warn(fmt, ap);
    va_end(ap);
    return (mc->status |= MAC_PARSE_ERROR);
};

/* MAC_EXP_ERR_RETURN - report parse error, set error flag, return status */

#define MAC_EXP_ERR_RETURN(mc, fmt, ...) do { \
  return (mac_exp_parse_error(mc, fmt, __VA_ARGS__)); \
    } while (0)

 /*
  * Postfix 3.0 introduces support for {text} operands. Only with these do we
  * support the ternary ?: operator and relational operators.
  * 
  * We cannot support operators in random text, because that would break Postfix
  * 2.11 compatibility. For example, with the expression "${name?value}", the
  * value is random text that may contain ':', '?', '{' and '}' characters.
  * In particular, with Postfix 2.2 .. 2.11, "${name??foo:{b}ar}" evaluates
  * to "?foo:{b}ar" or empty. There are explicit tests in this directory and
  * the postconf directory to ensure that Postfix 2.11 compatibility is
  * maintained.
  * 
  * Ideally, future Postfix configurations enclose random text operands inside
  * {} braces. These allow whitespace around operands, which improves
  * readability.
  */

/* MAC_EXP_FIND_LEFT_CURLY - skip over whitespace to '{', advance read ptr */

#define MAC_EXP_FIND_LEFT_CURLY(len, cp) \
  ((cp[len = strspn(cp, MAC_EXP_WHITESPACE)] == '{') ? \
   (cp += len) : 0)

/* mac_exp_extract_curly_payload - balance {}, skip whitespace, return payload */

static char *mac_exp_extract_curly_payload(MAC_EXP_CONTEXT *mc, char **bp)
{
    char   *payload;
    char   *cp;
    int     level;
    int     ch;

    /*
     * Extract the payload and balance the {}. The caller is expected to skip
     * leading whitespace before the {. See MAC_EXP_FIND_LEFT_CURLY().
     */
    for (level = 1, cp = *bp, payload = ++cp; /* see below */ ; cp++) {
  if ((ch = *cp) == 0) {
      mac_exp_parse_error(mc, "unbalanced {} in attribute expression: "
        "\"%s\"",
        *bp);
      return (0);
  } else if (ch == '{') {
      level++;
  } else if (ch == '}') {
      if (--level <= 0)
    break;
  }
    }
    *cp++ = 0;

    /*
     * Skip trailing whitespace after }.
     */
    *bp = cp + strspn(cp, MAC_EXP_WHITESPACE);
    return (payload);
}

/* mac_exp_parse_relational - parse relational expression, advance read ptr */

static int mac_exp_parse_relational(MAC_EXP_CONTEXT *mc, const char **lookup,
                    char **bp)
{
    char   *cp = *bp;
    VSTRING *left_op_buf;
    VSTRING *rite_op_buf;
    const char *left_op_strval;
    const char *rite_op_strval;
    char   *op_pos;
    char   *op_strval;
    size_t  op_len;
    int     op_tokval;
    int     op_result;
    size_t  tmp_len;
    char   *type_pos;
    size_t  type_len;
    MAC_EXPAND_RELOP_FN relop_eval;

    /*
     * Left operand. The caller is expected to skip leading whitespace before
     * the {. See MAC_EXP_FIND_LEFT_CURLY().
     */
    if ((left_op_strval = mac_exp_extract_curly_payload(mc, &cp)) == 0)
  return (mc->status);

    /*
     * Operator. Todo: regexp operator.
     */
    op_pos = cp;
    op_len = strspn(cp, "<>!=?+-*/~&|%"); /* for better diagnostics. */
    op_strval = mystrndup(cp, op_len);
    op_tokval = name_code(mac_exp_op_table, NAME_CODE_FLAG_NONE, op_strval);
    myfree(op_strval);
    if (op_tokval == MAC_EXP_OP_TOK_NONE)
  MAC_EXP_ERR_RETURN(mc, "%s expected at: \"...%s}>>>%.20s\"",
         MAC_EXP_OP_STR_ANY, left_op_strval, cp);
    cp += op_len;

    /*
     * Custom operator suffix.
     */
    if (mac_exp_ext_table && ISALNUM(*cp)) {
  type_pos = cp;
  for (type_len = 1; ISALNUM(cp[type_len]); type_len++)
       /* void */ ;
  cp += type_len;
  vstring_sprintf(mac_exp_ext_key, "%.*s",
      (int) (op_len + type_len), op_pos);
  if ((relop_eval = (MAC_EXPAND_RELOP_FN) htable_find(mac_exp_ext_table,
            STR(mac_exp_ext_key))) == 0)
      MAC_EXP_ERR_RETURN(mc, "bad operator suffix at: \"...%.*s>>>%.*s\"",
          (int) op_len, op_pos, (int) type_len, type_pos);
    } else {
  relop_eval = mac_exp_eval;
    }

    /*
     * Right operand. Todo: syntax may depend on operator.
     */
    if (MAC_EXP_FIND_LEFT_CURLY(tmp_len, cp) == 0)
  MAC_EXP_ERR_RETURN(mc, "\"{expression}\" expected at: "
         "\"...{%s} %.*s>>>%.20s\"",
         left_op_strval, (int) op_len, op_pos, cp);
    if ((rite_op_strval = mac_exp_extract_curly_payload(mc, &cp)) == 0)
  return (mc->status);

    /*
     * Evaluate the relational expression. Todo: regexp support.
     */
    mc->status |=
  mac_expand(left_op_buf = vstring_alloc(100), left_op_strval,
       mc->flags, mc->filter, mc->lookup, mc->context);
    mc->status |=
  mac_expand(rite_op_buf = vstring_alloc(100), rite_op_strval,
       mc->flags, mc->filter, mc->lookup, mc->context);
    if ((mc->flags & MAC_EXP_FLAG_SCAN) == 0
  && (op_result = relop_eval(vstring_str(left_op_buf), op_tokval,
       vstring_str(rite_op_buf))) == MAC_EXP_OP_RES_ERROR)
  mc->status |= MAC_PARSE_ERROR;
    vstring_free(left_op_buf);
    vstring_free(rite_op_buf);
    if (mc->status & MAC_PARSE_ERROR)
  return (mc->status);

    /*
     * Here, we fake up a non-empty or empty parameter value lookup result,
     * for compatibility with the historical code that looks named parameter
     * values.
     */
    if (mc->flags & MAC_EXP_FLAG_SCAN) {
  *lookup = 0;
    } else {
  switch (op_result) {
  case MAC_EXP_OP_RES_TRUE:
      *lookup = MAC_EXP_BVAL_TRUE;
      break;
  case MAC_EXP_OP_RES_FALSE:
      *lookup = MAC_EXP_BVAL_FALSE;
      break;
  default:
      msg_panic("mac_expand: unexpected operator result: %d", op_result);
  }
    }
    *bp = cp;
    return (0);
}

/* mac_expand_add_relop - register operator extensions */

void    mac_expand_add_relop(int *tok_list, const char *suffix,
                   MAC_EXPAND_RELOP_FN relop_eval)
{
    const char myname[] = "mac_expand_add_relop";
    const char *tok_name;
    int    *tp;

    /*
     * Sanity checks.
     */
    if (!allalnum(suffix))
  msg_panic("%s: bad operator suffix: %s", myname, suffix);

    /*
     * One-time initialization.
     */
    if (mac_exp_ext_table == 0) {
  mac_exp_ext_table = htable_create(10);
  mac_exp_ext_key = vstring_alloc(10);
    }
    for (tp = tok_list; *tp; tp++) {
  if ((tok_name = str_name_code(mac_exp_op_table, *tp)) == 0)
      msg_panic("%s: unknown token code: %d", myname, *tp);
  vstring_sprintf(mac_exp_ext_key, "%s%s", tok_name, suffix);
  if (htable_locate(mac_exp_ext_table, STR(mac_exp_ext_key)) != 0)
      msg_panic("%s: duplicate key: %s", myname, STR(mac_exp_ext_key));
  (void) htable_enter(mac_exp_ext_table,
          STR(mac_exp_ext_key), (void *) relop_eval);
    }
}

/* mac_expand_callback - callback for mac_parse */

static int mac_expand_callback(int type, VSTRING *buf, void *ptr)
{
    static const char myname[] = "mac_expand_callback";
    MAC_EXP_CONTEXT *mc = (MAC_EXP_CONTEXT *) ptr;
    int     lookup_mode;
    const char *lookup;
    char   *cp;
    int     ch;
    ssize_t res_len;
    ssize_t tmp_len;
    const char *res_iftrue;
    const char *res_iffalse;

    /*
     * Sanity check.
     */
    if (mc->level++ > 100)
  mac_exp_parse_error(mc, "unreasonable macro call nesting: \"%s\"",
          vstring_str(buf));
    if (mc->status & MAC_PARSE_ERROR)
  return (mc->status);

    /*
     * Named parameter or relational expression. In case of a syntax error,
     * return without doing damage, and issue a warning instead.
     */
    if (type == MAC_PARSE_EXPR) {

  cp = vstring_str(buf);

  /*
   * Relational expression. If recursion is disabled, perform only one
   * level of $name expansion.
   */
  if (MAC_EXP_FIND_LEFT_CURLY(tmp_len, cp)) {
      if (mac_exp_parse_relational(mc, &lookup, &cp) != 0)
    return (mc->status);

      /*
       * Look for the ? or : operator.
       */
      if ((ch = *cp) != 0) {
    if (ch != '?' && ch != ':')
        MAC_EXP_ERR_RETURN(mc, "\"?\" or \":\" expected at: "
               "\"...}>>>%.20s\"", cp);
    cp++;
      }
  }

  /*
   * Named parameter.
   */
  else {
      char   *start;

      /*
       * Look for the ? or : operator. In case of a syntax error,
       * return without doing damage, and issue a warning instead.
       */
      start = (cp += strspn(cp, MAC_EXP_WHITESPACE));
      for ( /* void */ ; /* void */ ; cp++) {
    if ((ch = cp[tmp_len = strspn(cp, MAC_EXP_WHITESPACE)]) == 0) {
        *cp = 0;
        lookup_mode = MAC_EXP_MODE_USE;
        break;
    }
    if (ch == '?' || ch == ':') {
        *cp++ = 0;
        cp += tmp_len;
        lookup_mode = MAC_EXP_MODE_TEST;
        break;
    }
    ch = *cp;
    if (!ISALNUM(ch) && ch != '_') {
        MAC_EXP_ERR_RETURN(mc, "attribute name syntax error at: "
               "\"...%.*s>>>%.20s\"",
               (int) (cp - vstring_str(buf)),
               vstring_str(buf), cp);
    }
      }

      /*
       * Look up the named parameter. Todo: allow the lookup function
       * to specify if the result is safe for $name expansion.
       */
      lookup = mc->lookup(start, lookup_mode, mc->context);
  }

  /*
   * Return the requested result. After parsing the result operand
   * following ?, we fall through to parse the result operand following
   * :. This is necessary with the ternary ?: operator: first, with
   * MAC_EXP_FLAG_SCAN to parse both result operands with mac_parse(),
   * and second, to find garbage after any result operand. Without
   * MAC_EXP_FLAG_SCAN the content of only one of the ?: result
   * operands will be parsed with mac_parse(); syntax errors in the
   * other operand will be missed.
   */
  switch (ch) {
  case '?':
      if (MAC_EXP_FIND_LEFT_CURLY(tmp_len, cp)) {
    if ((res_iftrue = mac_exp_extract_curly_payload(mc, &cp)) == 0)
        return (mc->status);
      } else {
    res_iftrue = cp;
    cp = "";      /* no left-over text */
      }
      if ((lookup != 0 && *lookup != 0) || (mc->flags & MAC_EXP_FLAG_SCAN))
    mc->status |= mac_parse(res_iftrue, mac_expand_callback,
          (void *) mc);
      if (*cp == 0)     /* end of input, OK */
    break;
      if (*cp != ':')     /* garbage */
    MAC_EXP_ERR_RETURN(mc, "\":\" expected at: "
           "\"...%s}>>>%.20s\"", res_iftrue, cp);
      cp += 1;
      /* FALLTHROUGH: do not remove, see comment above. */
  case ':':
      if (MAC_EXP_FIND_LEFT_CURLY(tmp_len, cp)) {
    if ((res_iffalse = mac_exp_extract_curly_payload(mc, &cp)) == 0)
        return (mc->status);
      } else {
    res_iffalse = cp;
    cp = "";      /* no left-over text */
      }
      if (lookup == 0 || *lookup == 0 || (mc->flags & MAC_EXP_FLAG_SCAN))
    mc->status |= mac_parse(res_iffalse, mac_expand_callback,
          (void *) mc);
      if (*cp != 0)     /* garbage */
    MAC_EXP_ERR_RETURN(mc, "unexpected input at: "
           "\"...%s}>>>%.20s\"", res_iffalse, cp);
      break;
  case 0:
      if (lookup == 0) {
    mc->status |= MAC_PARSE_UNDEF;
      } else if (*lookup == 0 || (mc->flags & MAC_EXP_FLAG_SCAN)) {
     /* void */ ;
      } else if (mc->flags & MAC_EXP_FLAG_RECURSE) {
    vstring_strcpy(buf, lookup);
    mc->status |= mac_parse(vstring_str(buf), mac_expand_callback,
          (void *) mc);
      } else {
    res_len = VSTRING_LEN(mc->result);
    vstring_strcat(mc->result, lookup);
    if (mc->flags & MAC_EXP_FLAG_PRINTABLE) {
        printable(vstring_str(mc->result) + res_len, '_');
    } else if (mc->filter) {
        cp = vstring_str(mc->result) + res_len;
        while (*(cp += strspn(cp, mc->filter)))
      *cp++ = '_';
    }
      }
      break;
  default:
      msg_panic("%s: unknown operator code %d", myname, ch);
  }
    }

    /*
     * Literal text.
     */
    else if ((mc->flags & MAC_EXP_FLAG_SCAN) == 0) {
  vstring_strcat(mc->result, vstring_str(buf));
    }
    mc->level--;

    return (mc->status);
}

/* mac_expand - expand $name instances */

int     mac_expand(VSTRING *result, const char *pattern, int flags,
               const char *filter,
               MAC_EXP_LOOKUP_FN lookup, void *context)
{
    MAC_EXP_CONTEXT mc;
    int     status;

    /*
     * Bundle up the request and do the substitutions.
     */
    mc.result = result;
    mc.flags = flags;
    mc.filter = filter;
    mc.lookup = lookup;
    mc.context = context;
    mc.status = 0;
    mc.level = 0;
    if ((flags & (MAC_EXP_FLAG_APPEND | MAC_EXP_FLAG_SCAN)) == 0)
  VSTRING_RESET(result);
    status = mac_parse(pattern, mac_expand_callback, (void *) &mc);
    if ((flags & MAC_EXP_FLAG_SCAN) == 0)
  VSTRING_TERMINATE(result);

    return (status);
}

#ifdef TEST

 /*
  * This code certainly deserves a stand-alone test program.
  */
#include <stringops.h>
#include <htable.h>
#include <vstream.h>
#include <vstring_vstream.h>

static const char *lookup(const char *name, int unused_mode, void *context)
{
    HTABLE *table = (HTABLE *) context;

    return (htable_find(table, name));
}

static MAC_EXP_OP_RES length_relop_eval(const char *left, int relop,
                  const char *rite)
{
    const char myname[] = "length_relop_eval";
    ssize_t delta = strlen(left) - strlen(rite);

    switch (relop) {
    case MAC_EXP_OP_TOK_EQ:
  return (mac_exp_op_res_bool[delta == 0]);
    case MAC_EXP_OP_TOK_NE:
  return (mac_exp_op_res_bool[delta != 0]);
    case MAC_EXP_OP_TOK_LT:
  return (mac_exp_op_res_bool[delta < 0]);
    case MAC_EXP_OP_TOK_LE:
  return (mac_exp_op_res_bool[delta <= 0]);
    case MAC_EXP_OP_TOK_GE:
  return (mac_exp_op_res_bool[delta >= 0]);
    case MAC_EXP_OP_TOK_GT:
  return (mac_exp_op_res_bool[delta > 0]);
    default:
  msg_panic("%s: unknown operator: %d",
      myname, relop);
    }
}

int     main(int unused_argc, char **argv)
{
    VSTRING *buf = vstring_alloc(100);
    VSTRING *result = vstring_alloc(100);
    char   *cp;
    char   *name;
    char   *value;
    HTABLE *table;
    int     stat;
    int     length_relops[] = {
  MAC_EXP_OP_TOK_EQ, MAC_EXP_OP_TOK_NE,
  MAC_EXP_OP_TOK_GT, MAC_EXP_OP_TOK_GE,
  MAC_EXP_OP_TOK_LT, MAC_EXP_OP_TOK_LE,
  0,
    };

    /*
     * Add relops that compare string lengths instead of content.
     */
    mac_expand_add_relop(length_relops, "length", length_relop_eval);

    /*
     * Loop over the inputs.
     */
    while (!vstream_feof(VSTREAM_IN)) {

  table = htable_create(0);

  /*
   * Read a block of definitions, terminated with an empty line.
   */
  while (vstring_get_nonl(buf, VSTREAM_IN) != VSTREAM_EOF) {
      vstream_printf("<< %s\n", vstring_str(buf));
      vstream_fflush(VSTREAM_OUT);
      if (VSTRING_LEN(buf) == 0)
    break;
      cp = vstring_str(buf);
      name = mystrtok(&cp, CHARS_SPACE "=");
      value = mystrtok(&cp, CHARS_SPACE "=");
      htable_enter(table, name, value ? mystrdup(value) : 0);
  }

  /*
   * Read a block of patterns, terminated with an empty line or EOF.
   */
  while (vstring_get_nonl(buf, VSTREAM_IN) != VSTREAM_EOF) {
      vstream_printf("<< %s\n", vstring_str(buf));
      vstream_fflush(VSTREAM_OUT);
      if (VSTRING_LEN(buf) == 0)
    break;
      cp = vstring_str(buf);
      VSTRING_RESET(result);
      stat = mac_expand(result, vstring_str(buf), MAC_EXP_FLAG_NONE,
            (char *) 0, lookup, (void *) table);
      vstream_printf("stat=%d result=%s\n", stat, vstring_str(result));
      vstream_fflush(VSTREAM_OUT);
  }
  htable_free(table, myfree);
  vstream_printf("\n");
    }

    /*
     * Clean up.
     */
    vstring_free(buf);
    vstring_free(result);
    exit(0);
}

#endif

Coverage Report

Created: 2024-02-11 06:14