1 /* -------------------------------------------------------------------------- **
2 * Microsoft Network Services for Unix, AKA., Andrew Tridgell's SAMBA.
4 * This module Copyright (C) 1990-1998 Karl Auer
6 * Rewritten almost completely by Christopher R. Hertel
7 * at the University of Minnesota, September, 1997.
8 * This module Copyright (C) 1997-1998 by the University of Minnesota
9 * -------------------------------------------------------------------------- **
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 3 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, see <http://www.gnu.org/licenses/>.
24 * -------------------------------------------------------------------------- **
28 * -------------------------------------------------------------------------- **
30 * This module performs lexical analysis and initial parsing of a
31 * Windows-like parameter file. It recognizes and handles four token
32 * types: section-name, parameter-name, parameter-value, and
33 * end-of-file. Comments and line continuation are handled
36 * The entry point to the module is function pm_process(). This
37 * function opens the source file, calls the Parse() function to parse
38 * the input, and then closes the file when either the EOF is reached
39 * or a fatal error is encountered.
41 * A sample parameter file might look like this:
44 * parameter one = value string
45 * parameter two = another value
47 * new parameter = some value or t'other
49 * The parameter file is divided into sections by section headers:
50 * section names enclosed in square brackets (eg. [section one]).
51 * Each section contains parameter lines, each of which consist of a
52 * parameter name and value delimited by an equal sign. Roughly, the
55 * <file> :== { <section> } EOF
57 * <section> :== <section header> { <parameter line> }
59 * <section header> :== '[' NAME ']'
61 * <parameter line> :== NAME '=' VALUE '\n'
63 * Blank lines and comment lines are ignored. Comment lines are lines
64 * beginning with either a semicolon (';') or a pound sign ('#').
66 * All whitespace in section names and parameter names is compressed
67 * to single spaces. Leading and trailing whitespace is stipped from
68 * both names and values.
70 * Only the first equals sign in a parameter line is significant.
71 * Parameter values may contain equals signs, square brackets and
72 * semicolons. Internal whitespace is retained in parameter values,
73 * with the exception of the '\r' character, which is stripped for
74 * historic reasons. Parameter names may not start with a left square
75 * bracket, an equal sign, a pound sign, or a semicolon, because these
76 * are used to identify other tokens.
78 * -------------------------------------------------------------------------- **
82 #include "system/locale.h"
84 /* -------------------------------------------------------------------------- **
91 /* we can't use FILE* due to the 256 fd limit - use this cheap hack
101 static int mygetc(myFILE
*f
)
103 if (f
->p
>= f
->buf
+f
->size
) return EOF
;
104 /* be sure to return chars >127 as positive values */
105 return (int)( *(f
->p
++) & 0x00FF );
108 /* -------------------------------------------------------------------------- **
112 static int EatWhitespace( myFILE
*InFile
)
113 /* ------------------------------------------------------------------------ **
114 * Scan past whitespace (see ctype(3C)) and return the first non-whitespace
115 * character, or newline, or EOF.
117 * Input: InFile - Input source.
119 * Output: The next non-whitespace character in the input stream.
121 * Notes: Because the config files use a line-oriented grammar, we
122 * explicitly exclude the newline character from the list of
123 * whitespace characters.
124 * - Note that both EOF (-1) and the nul character ('\0') are
125 * considered end-of-file markers.
127 * ------------------------------------------------------------------------ **
132 for( c
= mygetc( InFile
); isspace( c
) && ('\n' != c
); c
= mygetc( InFile
) )
135 } /* EatWhitespace */
137 static int EatComment( myFILE
*InFile
)
138 /* ------------------------------------------------------------------------ **
139 * Scan to the end of a comment.
141 * Input: InFile - Input source.
143 * Output: The character that marks the end of the comment. Normally,
144 * this will be a newline, but it *might* be an EOF.
146 * Notes: Because the config files use a line-oriented grammar, we
147 * explicitly exclude the newline character from the list of
148 * whitespace characters.
149 * - Note that both EOF (-1) and the nul character ('\0') are
150 * considered end-of-file markers.
152 * ------------------------------------------------------------------------ **
157 for( c
= mygetc( InFile
); ('\n'!=c
) && (EOF
!=c
) && (c
>0); c
= mygetc( InFile
) )
162 /*****************************************************************************
163 * Scan backards within a string to discover if the last non-whitespace
164 * character is a line-continuation character ('\\').
166 * Input: line - A pointer to a buffer containing the string to be
168 * pos - This is taken to be the offset of the end of the
169 * string. This position is *not* scanned.
171 * Output: The offset of the '\\' character if it was found, or -1 to
172 * indicate that it was not.
174 *****************************************************************************/
176 static int Continuation(char *line
, int pos
)
179 while( (pos
>= 0) && isspace((int)line
[pos
]))
182 return (((pos
>= 0) && ('\\' == line
[pos
])) ? pos
: -1 );
186 static bool Section( myFILE
*InFile
, bool (*sfunc
)(const char *, void *), void *userdata
)
187 /* ------------------------------------------------------------------------ **
188 * Scan a section name, and pass the name to function sfunc().
190 * Input: InFile - Input source.
191 * sfunc - Pointer to the function to be called if the section
192 * name is successfully read.
194 * Output: true if the section name was read and true was returned from
195 * <sfunc>. false if <sfunc> failed or if a lexical error was
198 * ------------------------------------------------------------------------ **
204 const char *func
= "params.c:Section() -";
206 i
= 0; /* <i> is the offset of the next free byte in bufr[] and */
207 end
= 0; /* <end> is the current "end of string" offset. In most */
208 /* cases these will be the same, but if the last */
209 /* character written to bufr[] is a space, then <end> */
210 /* will be one less than <i>. */
212 c
= EatWhitespace( InFile
); /* We've already got the '['. Scan */
213 /* past initial white space. */
215 while( (EOF
!= c
) && (c
> 0) )
218 /* Check that the buffer is big enough for the next character. */
219 if( i
> (InFile
->bSize
- 2) )
223 tb
= talloc_realloc(InFile
, InFile
->bufr
, char, InFile
->bSize
+ BUFR_INC
);
226 DEBUG(0, ("%s Memory re-allocation failure.", func
) );
230 InFile
->bSize
+= BUFR_INC
;
233 /* Handle a single character. */
236 case ']': /* Found the closing bracket. */
237 InFile
->bufr
[end
] = '\0';
238 if( 0 == end
) /* Don't allow an empty name. */
240 DEBUG(0, ("%s Empty section name in configuration file.\n", func
));
243 if( !sfunc(InFile
->bufr
,userdata
) ) /* Got a valid name. Deal with it. */
245 (void)EatComment( InFile
); /* Finish off the line. */
248 case '\n': /* Got newline before closing ']'. */
249 i
= Continuation( InFile
->bufr
, i
); /* Check for line continuation. */
252 InFile
->bufr
[end
] = '\0';
253 DEBUG(0, ("%s Badly formed line in configuration file: %s\n",
254 func
, InFile
->bufr
));
257 end
= ( (i
> 0) && (' ' == InFile
->bufr
[i
- 1]) ) ? (i
- 1) : (i
);
258 c
= mygetc( InFile
); /* Continue with next line. */
261 default: /* All else are a valid name chars. */
262 if( isspace( c
) ) /* One space per whitespace region. */
264 InFile
->bufr
[end
] = ' ';
266 c
= EatWhitespace( InFile
);
268 else /* All others copy verbatim. */
270 InFile
->bufr
[i
++] = c
;
272 c
= mygetc( InFile
);
277 /* We arrive here if we've met the EOF before the closing bracket. */
278 DEBUG(0, ("%s Unexpected EOF in the configuration file\n", func
));
282 static bool Parameter( myFILE
*InFile
, bool (*pfunc
)(const char *, const char *, void *), int c
, void *userdata
)
283 /* ------------------------------------------------------------------------ **
284 * Scan a parameter name and value, and pass these two fields to pfunc().
286 * Input: InFile - The input source.
287 * pfunc - A pointer to the function that will be called to
288 * process the parameter, once it has been scanned.
289 * c - The first character of the parameter name, which
290 * would have been read by Parse(). Unlike a comment
291 * line or a section header, there is no lead-in
292 * character that can be discarded.
294 * Output: true if the parameter name and value were scanned and processed
295 * successfully, else false.
297 * Notes: This function is in two parts. The first loop scans the
298 * parameter name. Internal whitespace is compressed, and an
299 * equal sign (=) terminates the token. Leading and trailing
300 * whitespace is discarded. The second loop scans the parameter
301 * value. When both have been successfully identified, they are
302 * passed to pfunc() for processing.
304 * ------------------------------------------------------------------------ **
307 int i
= 0; /* Position within bufr. */
308 int end
= 0; /* bufr[end] is current end-of-string. */
309 int vstart
= 0; /* Starting position of the parameter value. */
310 const char *func
= "params.c:Parameter() -";
312 /* Read the parameter name. */
313 while( 0 == vstart
) /* Loop until we've found the start of the value. */
316 if( i
> (InFile
->bSize
- 2) ) /* Ensure there's space for next char. */
320 tb
= talloc_realloc(InFile
, InFile
->bufr
, char, InFile
->bSize
+ BUFR_INC
);
323 DEBUG(0, ("%s Memory re-allocation failure.", func
) );
327 InFile
->bSize
+= BUFR_INC
;
332 case '=': /* Equal sign marks end of param name. */
333 if( 0 == end
) /* Don't allow an empty name. */
335 DEBUG(0, ("%s Invalid parameter name in config. file.\n", func
));
338 InFile
->bufr
[end
++] = '\0'; /* Mark end of string & advance. */
339 i
= end
; /* New string starts here. */
340 vstart
= end
; /* New string is parameter value. */
341 InFile
->bufr
[i
] = '\0'; /* New string is nul, for now. */
344 case '\n': /* Find continuation char, else error. */
345 i
= Continuation( InFile
->bufr
, i
);
348 InFile
->bufr
[end
] = '\0';
349 DEBUG(1,("%s Ignoring badly formed line in configuration file: %s\n",
350 func
, InFile
->bufr
));
353 end
= ( (i
> 0) && (' ' == InFile
->bufr
[i
- 1]) ) ? (i
- 1) : (i
);
354 c
= mygetc( InFile
); /* Read past eoln. */
357 case '\0': /* Shouldn't have EOF within param name. */
359 InFile
->bufr
[i
] = '\0';
360 DEBUG(1,("%s Unexpected end-of-file at: %s\n", func
, InFile
->bufr
));
364 if( isspace( c
) ) /* One ' ' per whitespace region. */
366 InFile
->bufr
[end
] = ' ';
368 c
= EatWhitespace( InFile
);
370 else /* All others verbatim. */
372 InFile
->bufr
[i
++] = c
;
374 c
= mygetc( InFile
);
379 /* Now parse the value. */
380 c
= EatWhitespace( InFile
); /* Again, trim leading whitespace. */
381 while( (EOF
!=c
) && (c
> 0) )
384 if( i
> (InFile
->bSize
- 2) ) /* Make sure there's enough room. */
388 tb
= talloc_realloc(InFile
, InFile
->bufr
, char, InFile
->bSize
+ BUFR_INC
);
391 DEBUG(0, ("%s Memory re-allocation failure.", func
) );
395 InFile
->bSize
+= BUFR_INC
;
400 case '\r': /* Explicitly remove '\r' because the older */
401 c
= mygetc( InFile
); /* version called fgets_slash() which also */
402 break; /* removes them. */
404 case '\n': /* Marks end of value unless there's a '\'. */
405 i
= Continuation( InFile
->bufr
, i
);
410 for( end
= i
; (end
>= 0) && isspace((int)InFile
->bufr
[end
]); end
-- )
412 c
= mygetc( InFile
);
416 default: /* All others verbatim. Note that spaces do */
417 InFile
->bufr
[i
++] = c
; /* not advance <end>. This allows trimming */
418 if( !isspace( c
) ) /* of whitespace at the end of the line. */
420 c
= mygetc( InFile
);
424 InFile
->bufr
[end
] = '\0'; /* End of value. */
426 return( pfunc( InFile
->bufr
, &InFile
->bufr
[vstart
], userdata
) ); /* Pass name & value to pfunc(). */
429 static bool Parse( myFILE
*InFile
,
430 bool (*sfunc
)(const char *, void *),
431 bool (*pfunc
)(const char *, const char *, void *),
433 /* ------------------------------------------------------------------------ **
434 * Scan & parse the input.
436 * Input: InFile - Input source.
437 * sfunc - Function to be called when a section name is scanned.
439 * pfunc - Function to be called when a parameter is scanned.
442 * Output: true if the file was successfully scanned, else false.
444 * Notes: The input can be viewed in terms of 'lines'. There are four
446 * Blank - May contain whitespace, otherwise empty.
447 * Comment - First non-whitespace character is a ';' or '#'.
448 * The remainder of the line is ignored.
449 * Section - First non-whitespace character is a '['.
450 * Parameter - The default case.
452 * ------------------------------------------------------------------------ **
457 c
= EatWhitespace( InFile
);
458 while( (EOF
!= c
) && (c
> 0) )
462 case '\n': /* Blank line. */
463 c
= EatWhitespace( InFile
);
466 case ';': /* Comment line. */
468 c
= EatComment( InFile
);
471 case '[': /* Section Header. */
472 if( !Section( InFile
, sfunc
, userdata
) )
474 c
= EatWhitespace( InFile
);
477 case '\\': /* Bogus backslash. */
478 c
= EatWhitespace( InFile
);
481 default: /* Parameter line. */
482 if( !Parameter( InFile
, pfunc
, c
, userdata
) )
484 c
= EatWhitespace( InFile
);
491 static myFILE
*OpenConfFile( const char *FileName
)
492 /* ------------------------------------------------------------------------ **
493 * Open a configuration file.
495 * Input: FileName - The pathname of the config file to be opened.
497 * Output: A pointer of type (char **) to the lines of the file
499 * ------------------------------------------------------------------------ **
502 const char *func
= "params.c:OpenConfFile() -";
505 ret
= talloc(talloc_autofree_context(), myFILE
);
506 if (!ret
) return NULL
;
508 ret
->buf
= file_load(FileName
, &ret
->size
, 0, ret
);
509 if( NULL
== ret
->buf
)
512 ("%s Unable to open configuration file \"%s\":\n\t%s\n",
513 func
, FileName
, strerror(errno
)) );
524 bool pm_process( const char *FileName
,
525 bool (*sfunc
)(const char *, void *),
526 bool (*pfunc
)(const char *, const char *, void *),
528 /* ------------------------------------------------------------------------ **
529 * Process the named parameter file.
531 * Input: FileName - The pathname of the parameter file to be opened.
532 * sfunc - A pointer to a function that will be called when
533 * a section name is discovered.
534 * pfunc - A pointer to a function that will be called when
535 * a parameter name and value are discovered.
537 * Output: TRUE if the file was successfully parsed, else FALSE.
539 * ------------------------------------------------------------------------ **
544 const char *func
= "params.c:pm_process() -";
546 InFile
= OpenConfFile( FileName
); /* Open the config file. */
550 DEBUG( 3, ("%s Processing configuration file \"%s\"\n", func
, FileName
) );
552 if( NULL
!= InFile
->bufr
) /* If we already have a buffer */
553 result
= Parse( InFile
, sfunc
, pfunc
, userdata
); /* (recursive call), then just */
556 else /* If we don't have a buffer */
557 { /* allocate one, then parse, */
558 InFile
->bSize
= BUFR_INC
; /* then free. */
559 InFile
->bufr
= talloc_array(InFile
, char, InFile
->bSize
);
560 if( NULL
== InFile
->bufr
)
562 DEBUG(0,("%s memory allocation failure.\n", func
));
566 result
= Parse( InFile
, sfunc
, pfunc
, userdata
);
573 if( !result
) /* Generic failure. */
575 DEBUG(0,("%s Failed. Error returned from params.c:parse().\n", func
));
579 return( true ); /* Generic success. */
582 /* -------------------------------------------------------------------------- */