source: branches/samba-3.0/source/param/params.c@ 182

Last change on this file since 182 was 1, checked in by Paul Smedley, 18 years ago

Initial code import
File size: 18.8 KB
Line 
1/* -------------------------------------------------------------------------- **
2 * Microsoft Network Services for Unix, AKA., Andrew Tridgell's SAMBA.
3 *
4 * This module Copyright (C) 1990-1998 Karl Auer
5 *
6 * Rewritten almost completely by Christopher R. Hertel, 1997.
7 * This module Copyright (C) 1997-1998 by Christopher R. Hertel
8 *
9 * -------------------------------------------------------------------------- **
10 *
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 2 of the License, or
14 * (at your option) any later version.
15 *
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.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 *
25 * -------------------------------------------------------------------------- **
26 *
27 * Module name: params
28 *
29 * -------------------------------------------------------------------------- **
30 *
31 * This module performs lexical analysis and initial parsing of a
32 * Windows-like parameter file. It recognizes and handles four token
33 * types: section-name, parameter-name, parameter-value, and
34 * end-of-file. Comments and line continuation are handled
35 * internally.
36 *
37 * The entry point to the module is function pm_process(). This
38 * function opens the source file, calls the Parse() function to parse
39 * the input, and then closes the file when either the EOF is reached
40 * or a fatal error is encountered.
41 *
42 * A sample parameter file might look like this:
43 *
44 * [section one]
45 * parameter one = value string
46 * parameter two = another value
47 * [section two]
48 * new parameter = some value or t'other
49 *
50 * The parameter file is divided into sections by section headers:
51 * section names enclosed in square brackets (eg. [section one]).
52 * Each section contains parameter lines, each of which consist of a
53 * parameter name and value delimited by an equal sign. Roughly, the
54 * syntax is:
55 *
56 * <file> :== { <section> } EOF
57 *
58 * <section> :== <section header> { <parameter line> }
59 *
60 * <section header> :== '[' NAME ']'
61 *
62 * <parameter line> :== NAME '=' VALUE '\n'
63 *
64 * Blank lines and comment lines are ignored. Comment lines are lines
65 * beginning with either a semicolon (';') or a pound sign ('#').
66 *
67 * All whitespace in section names and parameter names is compressed
68 * to single spaces. Leading and trailing whitespace is stipped from
69 * both names and values.
70 *
71 * Only the first equals sign in a parameter line is significant.
72 * Parameter values may contain equals signs, square brackets and
73 * semicolons. Internal whitespace is retained in parameter values,
74 * with the exception of the '\r' character, which is stripped for
75 * historic reasons. Parameter names may not start with a left square
76 * bracket, an equal sign, a pound sign, or a semicolon, because these
77 * are used to identify other tokens.
78 *
79 * -------------------------------------------------------------------------- **
80 */
81
82#include "includes.h"
83
84extern BOOL in_client;
85
86/* -------------------------------------------------------------------------- **
87 * Constants...
88 */
89
90#define BUFR_INC 1024
91
92
93/* -------------------------------------------------------------------------- **
94 * Variables...
95 *
96 * DEBUGLEVEL - The ubiquitous DEBUGLEVEL. This determines which DEBUG()
97 * messages will be produced.
98 * bufr - pointer to a global buffer. This is probably a kludge,
99 * but it was the nicest kludge I could think of (for now).
100 * bSize - The size of the global buffer <bufr>.
101 */
102
103static char *bufr = NULL;
104static int bSize = 0;
105
106/* we can't use FILE* due to the 256 fd limit - use this cheap hack
107 instead */
108typedef struct {
109 char *buf;
110 char *p;
111 size_t size;
112 char *end_section_p;
113} myFILE;
114
115static int mygetc(myFILE *f)
116{
117 if (f->p >= f->buf+f->size)
118 return EOF;
119 /* be sure to return chars >127 as positive values */
120 return (int)( *(f->p++) & 0x00FF );
121}
122
123static void myfile_close(myFILE *f)
124{
125 if (!f)
126 return;
127 SAFE_FREE(f->buf);
128 SAFE_FREE(f);
129}
130
131/* Find the end of the section. We must use mb functions for this. */
132static int FindSectionEnd(myFILE *f)
133{
134 f->end_section_p = strchr_m(f->p, ']');
135 return f->end_section_p ? 1 : 0;
136}
137
138static int AtSectionEnd(myFILE *f)
139{
140 if (f->p == f->end_section_p + 1) {
141 f->end_section_p = NULL;
142 return 1;
143 }
144 return 0;
145}
146
147/* -------------------------------------------------------------------------- **
148 * Functions...
149 */
150 /* ------------------------------------------------------------------------ **
151 * Scan past whitespace (see ctype(3C)) and return the first non-whitespace
152 * character, or newline, or EOF.
153 *
154 * Input: InFile - Input source.
155 *
156 * Output: The next non-whitespace character in the input stream.
157 *
158 * Notes: Because the config files use a line-oriented grammar, we
159 * explicitly exclude the newline character from the list of
160 * whitespace characters.
161 * - Note that both EOF (-1) and the nul character ('\0') are
162 * considered end-of-file markers.
163 *
164 * ------------------------------------------------------------------------ **
165 */
166
167static int EatWhitespace( myFILE *InFile )
168{
169 int c;
170
171 for( c = mygetc( InFile ); isspace( c ) && ('\n' != c); c = mygetc( InFile ) )
172 ;
173 return( c );
174}
175
176 /* ------------------------------------------------------------------------ **
177 * Scan to the end of a comment.
178 *
179 * Input: InFile - Input source.
180 *
181 * Output: The character that marks the end of the comment. Normally,
182 * this will be a newline, but it *might* be an EOF.
183 *
184 * Notes: Because the config files use a line-oriented grammar, we
185 * explicitly exclude the newline character from the list of
186 * whitespace characters.
187 * - Note that both EOF (-1) and the nul character ('\0') are
188 * considered end-of-file markers.
189 *
190 * ------------------------------------------------------------------------ **
191 */
192
193static int EatComment( myFILE *InFile )
194{
195 int c;
196
197 for( c = mygetc( InFile ); ('\n'!=c) && (EOF!=c) && (c>0); c = mygetc( InFile ) )
198 ;
199 return( c );
200}
201
202/*****************************************************************************
203 * Scan backards within a string to discover if the last non-whitespace
204 * character is a line-continuation character ('\\').
205 *
206 * Input: line - A pointer to a buffer containing the string to be
207 * scanned.
208 * pos - This is taken to be the offset of the end of the
209 * string. This position is *not* scanned.
210 *
211 * Output: The offset of the '\\' character if it was found, or -1 to
212 * indicate that it was not.
213 *
214 *****************************************************************************/
215
216static int Continuation(char *line, int pos )
217{
218 pos--;
219 while( (pos >= 0) && isspace((int)line[pos]))
220 pos--;
221
222 return (((pos >= 0) && ('\\' == line[pos])) ? pos : -1 );
223}
224
225/* ------------------------------------------------------------------------ **
226 * Scan a section name, and pass the name to function sfunc().
227 *
228 * Input: InFile - Input source.
229 * sfunc - Pointer to the function to be called if the section
230 * name is successfully read.
231 *
232 * Output: True if the section name was read and True was returned from
233 * <sfunc>. False if <sfunc> failed or if a lexical error was
234 * encountered.
235 *
236 * ------------------------------------------------------------------------ **
237 */
238
239static BOOL Section( myFILE *InFile, BOOL (*sfunc)(const char *) )
240{
241 int c;
242 int i;
243 int end;
244 const char *func = "params.c:Section() -";
245
246 i = 0; /* <i> is the offset of the next free byte in bufr[] and */
247 end = 0; /* <end> is the current "end of string" offset. In most */
248 /* cases these will be the same, but if the last */
249 /* character written to bufr[] is a space, then <end> */
250 /* will be one less than <i>. */
251
252
253 /* Find the end of the section. We must use mb functions for this. */
254 if (!FindSectionEnd(InFile)) {
255 DEBUG(0, ("%s No terminating ']' character in section.\n", func) );
256 return False;
257 }
258
259 c = EatWhitespace( InFile ); /* We've already got the '['. Scan */
260 /* past initial white space. */
261
262 while( (EOF != c) && (c > 0) ) {
263 /* Check that the buffer is big enough for the next character. */
264 if( i > (bSize - 2) ) {
265 char *tb = (char *)SMB_REALLOC_KEEP_OLD_ON_ERROR( bufr, bSize +BUFR_INC );
266 if(!tb) {
267 DEBUG(0, ("%s Memory re-allocation failure.", func) );
268 return False;
269 }
270 bufr = tb;
271 bSize += BUFR_INC;
272 }
273
274 /* Handle a single character other than section end. */
275 switch( c ) {
276 case '\n': /* Got newline before closing ']'. */
277 i = Continuation( bufr, i ); /* Check for line continuation. */
278 if( i < 0 ) {
279 bufr[end] = '\0';
280 DEBUG(0, ("%s Badly formed line in configuration file: %s\n", func, bufr ));
281 return False;
282 }
283 end = ( (i > 0) && (' ' == bufr[i - 1]) ) ? (i - 1) : (i);
284 c = mygetc( InFile ); /* Continue with next line. */
285 break;
286
287 default: /* All else are a valid name chars. */
288 if(isspace( c )) {
289 /* One space per whitespace region. */
290 bufr[end] = ' ';
291 i = end + 1;
292 c = EatWhitespace( InFile );
293 } else {
294 bufr[i++] = c;
295 end = i;
296 c = mygetc( InFile );
297 }
298 }
299
300 if (AtSectionEnd(InFile)) {
301 /* Got to the closing bracket. */
302 bufr[end] = '\0';
303 if( 0 == end ) {
304 /* Don't allow an empty name. */
305 DEBUG(0, ("%s Empty section name in configuration file.\n", func ));
306 return False;
307 }
308 if( !sfunc(bufr) ) /* Got a valid name. Deal with it. */
309 return False;
310 EatComment( InFile ); /* Finish off the line. */
311 return True;
312 }
313
314 }
315
316 /* We arrive here if we've met the EOF before the closing bracket. */
317 DEBUG(0, ("%s Unexpected EOF in the configuration file: %s\n", func, bufr ));
318 return False;
319}
320
321/* ------------------------------------------------------------------------ **
322 * Scan a parameter name and value, and pass these two fields to pfunc().
323 *
324 * Input: InFile - The input source.
325 * pfunc - A pointer to the function that will be called to
326 * process the parameter, once it has been scanned.
327 * c - The first character of the parameter name, which
328 * would have been read by Parse(). Unlike a comment
329 * line or a section header, there is no lead-in
330 * character that can be discarded.
331 *
332 * Output: True if the parameter name and value were scanned and processed
333 * successfully, else False.
334 *
335 * Notes: This function is in two parts. The first loop scans the
336 * parameter name. Internal whitespace is compressed, and an
337 * equal sign (=) terminates the token. Leading and trailing
338 * whitespace is discarded. The second loop scans the parameter
339 * value. When both have been successfully identified, they are
340 * passed to pfunc() for processing.
341 *
342 * ------------------------------------------------------------------------ **
343 */
344
345static BOOL Parameter( myFILE *InFile, BOOL (*pfunc)(const char *, const char *), int c )
346{
347 int i = 0; /* Position within bufr. */
348 int end = 0; /* bufr[end] is current end-of-string. */
349 int vstart = 0; /* Starting position of the parameter value. */
350 const char *func = "params.c:Parameter() -";
351
352 /* Read the parameter name. */
353 while( 0 == vstart ) {
354 /* Loop until we've found the start of the value. */
355 if( i > (bSize - 2) ) {
356 /* Ensure there's space for next char. */
357 char *tb = (char *)SMB_REALLOC_KEEP_OLD_ON_ERROR( bufr, bSize + BUFR_INC );
358 if (!tb) {
359 DEBUG(0, ("%s Memory re-allocation failure.", func) );
360 return False;
361 }
362 bufr = tb;
363 bSize += BUFR_INC;
364 }
365
366 switch(c) {
367 case '=': /* Equal sign marks end of param name. */
368 if( 0 == end ) {
369 /* Don't allow an empty name. */
370 DEBUG(0, ("%s Invalid parameter name in config. file.\n", func ));
371 return False;
372 }
373 bufr[end++] = '\0'; /* Mark end of string & advance. */
374 i = end; /* New string starts here. */
375 vstart = end; /* New string is parameter value. */
376 bufr[i] = '\0'; /* New string is nul, for now. */
377 break;
378
379 case '\n': /* Find continuation char, else error. */
380 i = Continuation( bufr, i );
381 if( i < 0 ) {
382 bufr[end] = '\0';
383 DEBUG(1,("%s Ignoring badly formed line in configuration file: %s\n", func, bufr ));
384 return True;
385 }
386 end = ( (i > 0) && (' ' == bufr[i - 1]) ) ? (i - 1) : (i);
387 c = mygetc( InFile ); /* Read past eoln. */
388 break;
389
390 case '\0': /* Shouldn't have EOF within param name. */
391 case EOF:
392 bufr[i] = '\0';
393 DEBUG(1,("%s Unexpected end-of-file at: %s\n", func, bufr ));
394 return True;
395
396 default:
397 if(isspace( c )) {
398 /* One ' ' per whitespace region. */
399 bufr[end] = ' ';
400 i = end + 1;
401 c = EatWhitespace( InFile );
402 } else {
403 bufr[i++] = c;
404 end = i;
405 c = mygetc( InFile );
406 }
407 }
408 }
409
410 /* Now parse the value. */
411 c = EatWhitespace( InFile ); /* Again, trim leading whitespace. */
412 while( (EOF !=c) && (c > 0) ) {
413 if( i > (bSize - 2) ) {
414 /* Make sure there's enough room. */
415 char *tb = (char *)SMB_REALLOC_KEEP_OLD_ON_ERROR( bufr, bSize + BUFR_INC );
416 if (!tb) {
417 DEBUG(0, ("%s Memory re-allocation failure.", func));
418 return False;
419 }
420 bufr = tb;
421 bSize += BUFR_INC;
422 }
423
424 switch(c) {
425 case '\r': /* Explicitly remove '\r' because the older */
426 c = mygetc( InFile ); /* version called fgets_slash() which also */
427 break; /* removes them. */
428
429 case '\n': /* Marks end of value unless there's a '\'. */
430 i = Continuation( bufr, i );
431 if( i < 0 ) {
432 c = 0;
433 } else {
434 for( end = i; (end >= 0) && isspace((int)bufr[end]); end-- )
435 ;
436 c = mygetc( InFile );
437 }
438 break;
439
440 default: /* All others verbatim. Note that spaces do not advance <end>. This allows trimming */
441 bufr[i++] = c;
442 if( !isspace( c ) ) /* of whitespace at the end of the line. */
443 end = i;
444 c = mygetc( InFile );
445 break;
446 }
447 }
448 bufr[end] = '\0'; /* End of value. */
449
450 return( pfunc( bufr, &bufr[vstart] ) ); /* Pass name & value to pfunc(). */
451}
452
453/* ------------------------------------------------------------------------ **
454 * Scan & parse the input.
455 *
456 * Input: InFile - Input source.
457 * sfunc - Function to be called when a section name is scanned.
458 * See Section().
459 * pfunc - Function to be called when a parameter is scanned.
460 * See Parameter().
461 *
462 * Output: True if the file was successfully scanned, else False.
463 *
464 * Notes: The input can be viewed in terms of 'lines'. There are four
465 * types of lines:
466 * Blank - May contain whitespace, otherwise empty.
467 * Comment - First non-whitespace character is a ';' or '#'.
468 * The remainder of the line is ignored.
469 * Section - First non-whitespace character is a '['.
470 * Parameter - The default case.
471 *
472 * ------------------------------------------------------------------------ **
473 */
474
475static BOOL Parse( myFILE *InFile,
476 BOOL (*sfunc)(const char *),
477 BOOL (*pfunc)(const char *, const char *) )
478{
479 int c;
480
481 c = EatWhitespace( InFile );
482 while( (EOF != c) && (c > 0) ) {
483 switch( c ) {
484 case '\n': /* Blank line. */
485 c = EatWhitespace( InFile );
486 break;
487
488 case ';': /* Comment line. */
489 case '#':
490 c = EatComment( InFile );
491 break;
492
493 case '[': /* Section Header. */
494 if( !Section( InFile, sfunc ) )
495 return False;
496 c = EatWhitespace( InFile );
497 break;
498
499 case '\\': /* Bogus backslash. */
500 c = EatWhitespace( InFile );
501 break;
502
503 default: /* Parameter line. */
504 if( !Parameter( InFile, pfunc, c ) )
505 return False;
506 c = EatWhitespace( InFile );
507 break;
508 }
509 }
510 return True;
511}
512
513/* ------------------------------------------------------------------------ **
514 * Open a configuration file.
515 *
516 * Input: FileName - The pathname of the config file to be opened.
517 *
518 * Output: A pointer of type (char **) to the lines of the file
519 *
520 * ------------------------------------------------------------------------ **
521 */
522
523static myFILE *OpenConfFile( const char *FileName )
524{
525 const char *func = "params.c:OpenConfFile() -";
526 int lvl = in_client?1:0;
527 myFILE *ret;
528
529 ret = SMB_MALLOC_P(myFILE);
530 if (!ret)
531 return NULL;
532
533 ret->buf = file_load(FileName, &ret->size, 0);
534 if( NULL == ret->buf ) {
535 DEBUG( lvl, ("%s Unable to open configuration file \"%s\":\n\t%s\n",
536 func, FileName, strerror(errno)) );
537 SAFE_FREE(ret);
538 return NULL;
539 }
540
541 ret->p = ret->buf;
542 ret->end_section_p = NULL;
543 return( ret );
544}
545
546/* ------------------------------------------------------------------------ **
547 * Process the named parameter file.
548 *
549 * Input: FileName - The pathname of the parameter file to be opened.
550 * sfunc - A pointer to a function that will be called when
551 * a section name is discovered.
552 * pfunc - A pointer to a function that will be called when
553 * a parameter name and value are discovered.
554 *
555 * Output: TRUE if the file was successfully parsed, else FALSE.
556 *
557 * ------------------------------------------------------------------------ **
558 */
559
560BOOL pm_process( const char *FileName,
561 BOOL (*sfunc)(const char *),
562 BOOL (*pfunc)(const char *, const char *) )
563{
564 int result;
565 myFILE *InFile;
566 const char *func = "params.c:pm_process() -";
567
568 InFile = OpenConfFile( FileName ); /* Open the config file. */
569 if( NULL == InFile )
570 return False;
571
572 DEBUG( 3, ("%s Processing configuration file \"%s\"\n", func, FileName) );
573
574 if( NULL != bufr ) {
575 /* If we already have a buffer */
576 /* (recursive call), then just */
577 /* use it. */
578 result = Parse( InFile, sfunc, pfunc );
579 } else {
580 bSize = BUFR_INC;
581 bufr = (char *)SMB_MALLOC( bSize );
582 if( NULL == bufr ) {
583 DEBUG(0,("%s memory allocation failure.\n", func));
584 myfile_close(InFile);
585 return False;
586 }
587
588 result = Parse( InFile, sfunc, pfunc );
589 SAFE_FREE( bufr );
590 bSize = 0;
591 }
592
593 myfile_close(InFile);
594
595 if( !result ) {
596 DEBUG(0,("%s Failed. Error returned from params.c:parse().\n", func));
597 return False;
598 }
599
600 return True;
601}
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