source: branches/samba-3.3.x/source/param/params.c

Last change on this file was 206, checked in by Herwig Bauernfeind, 16 years ago

Import Samba 3.3 branch at 3.0.0 level (psmedley's port)
File size: 19.0 KB
RevLine 
[206]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 3 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, see <http://www.gnu.org/licenses/>.
23 *
24 * -------------------------------------------------------------------------- **
25 *
26 * Module name: params
27 *
28 * -------------------------------------------------------------------------- **
29 *
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
34 * internally.
35 *
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.
40 *
41 * A sample parameter file might look like this:
42 *
43 * [section one]
44 * parameter one = value string
45 * parameter two = another value
46 * [section two]
47 * new parameter = some value or t'other
48 *
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
53 * syntax is:
54 *
55 * <file> :== { <section> } EOF
56 *
57 * <section> :== <section header> { <parameter line> }
58 *
59 * <section header> :== '[' NAME ']'
60 *
61 * <parameter line> :== NAME '=' VALUE '\n'
62 *
63 * Blank lines and comment lines are ignored. Comment lines are lines
64 * beginning with either a semicolon (';') or a pound sign ('#').
65 *
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.
69 *
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.
77 *
78 * -------------------------------------------------------------------------- **
79 */
80
81#include "includes.h"
82
83/* -------------------------------------------------------------------------- **
84 * Constants...
85 */
86
87#define BUFR_INC 1024
88
89
90/* -------------------------------------------------------------------------- **
91 * Variables...
92 *
93 * DEBUGLEVEL - The ubiquitous DEBUGLEVEL. This determines which DEBUG()
94 * messages will be produced.
95 * bufr - pointer to a global buffer. This is probably a kludge,
96 * but it was the nicest kludge I could think of (for now).
97 * bSize - The size of the global buffer <bufr>.
98 */
99
100/* we can't use FILE* due to the 256 fd limit - use this cheap hack
101 instead */
102typedef struct {
103 char *buf;
104 char *p;
105 size_t size;
106 char *end_section_p;
107} myFILE;
108
109static int mygetc(myFILE *f)
110{
111 if (f->p >= f->buf+f->size)
112 return EOF;
113 /* be sure to return chars >127 as positive values */
114 return (int)( *(f->p++) & 0x00FF );
115}
116
117static void myfile_close(myFILE *f)
118{
119 if (!f)
120 return;
121 SAFE_FREE(f->buf);
122 SAFE_FREE(f);
123}
124
125/* Find the end of the section. We must use mb functions for this. */
126static int FindSectionEnd(myFILE *f)
127{
128 f->end_section_p = strchr_m(f->p, ']');
129 return f->end_section_p ? 1 : 0;
130}
131
132static int AtSectionEnd(myFILE *f)
133{
134 if (f->p == f->end_section_p + 1) {
135 f->end_section_p = NULL;
136 return 1;
137 }
138 return 0;
139}
140
141/* -------------------------------------------------------------------------- **
142 * Functions...
143 */
144 /* ------------------------------------------------------------------------ **
145 * Scan past whitespace (see ctype(3C)) and return the first non-whitespace
146 * character, or newline, or EOF.
147 *
148 * Input: InFile - Input source.
149 *
150 * Output: The next non-whitespace character in the input stream.
151 *
152 * Notes: Because the config files use a line-oriented grammar, we
153 * explicitly exclude the newline character from the list of
154 * whitespace characters.
155 * - Note that both EOF (-1) and the nul character ('\0') are
156 * considered end-of-file markers.
157 *
158 * ------------------------------------------------------------------------ **
159 */
160
161static int EatWhitespace( myFILE *InFile )
162{
163 int c;
164
165 for( c = mygetc( InFile ); isspace( c ) && ('\n' != c); c = mygetc( InFile ) )
166 ;
167 return( c );
168}
169
170 /* ------------------------------------------------------------------------ **
171 * Scan to the end of a comment.
172 *
173 * Input: InFile - Input source.
174 *
175 * Output: The character that marks the end of the comment. Normally,
176 * this will be a newline, but it *might* be an EOF.
177 *
178 * Notes: Because the config files use a line-oriented grammar, we
179 * explicitly exclude the newline character from the list of
180 * whitespace characters.
181 * - Note that both EOF (-1) and the nul character ('\0') are
182 * considered end-of-file markers.
183 *
184 * ------------------------------------------------------------------------ **
185 */
186
187static int EatComment( myFILE *InFile )
188{
189 int c;
190
191 for( c = mygetc( InFile ); ('\n'!=c) && (EOF!=c) && (c>0); c = mygetc( InFile ) )
192 ;
193 return( c );
194}
195
196/*****************************************************************************
197 * Scan backards within a string to discover if the last non-whitespace
198 * character is a line-continuation character ('\\').
199 *
200 * Input: line - A pointer to a buffer containing the string to be
201 * scanned.
202 * pos - This is taken to be the offset of the end of the
203 * string. This position is *not* scanned.
204 *
205 * Output: The offset of the '\\' character if it was found, or -1 to
206 * indicate that it was not.
207 *
208 *****************************************************************************/
209
210static int Continuation(uint8_t *line, int pos )
211{
212 pos--;
213 while( (pos >= 0) && isspace((int)line[pos]))
214 pos--;
215
216 return (((pos >= 0) && ('\\' == line[pos])) ? pos : -1 );
217}
218
219/* ------------------------------------------------------------------------ **
220 * Scan a section name, and pass the name to function sfunc().
221 *
222 * Input: InFile - Input source.
223 * sfunc - Pointer to the function to be called if the section
224 * name is successfully read.
225 *
226 * Output: True if the section name was read and True was returned from
227 * <sfunc>. False if <sfunc> failed or if a lexical error was
228 * encountered.
229 *
230 * ------------------------------------------------------------------------ **
231 */
232
233static bool Section( DATA_BLOB *buf, myFILE *InFile, bool (*sfunc)(const char *, void *), void *userdata )
234{
235 int c;
236 int i;
237 int end;
238 const char *func = "params.c:Section() -";
239
240 i = 0; /* <i> is the offset of the next free byte in bufr[] and */
241 end = 0; /* <end> is the current "end of string" offset. In most */
242 /* cases these will be the same, but if the last */
243 /* character written to bufr[] is a space, then <end> */
244 /* will be one less than <i>. */
245
246
247 /* Find the end of the section. We must use mb functions for this. */
248 if (!FindSectionEnd(InFile)) {
249 DEBUG(0, ("%s No terminating ']' character in section.\n", func) );
250 return False;
251 }
252
253 c = EatWhitespace( InFile ); /* We've already got the '['. Scan */
254 /* past initial white space. */
255
256 while( (EOF != c) && (c > 0) ) {
257 /* Check that the buffer is big enough for the next character. */
258 if( i > (buf->length - 2) ) {
259 uint8_t *tb = (uint8_t *)SMB_REALLOC_KEEP_OLD_ON_ERROR(buf->data, buf->length+BUFR_INC );
260 if(!tb) {
261 DEBUG(0, ("%s Memory re-allocation failure.", func) );
262 return False;
263 }
264 buf->data = tb;
265 buf->length += BUFR_INC;
266 }
267
268 /* Handle a single character other than section end. */
269 switch( c ) {
270 case '\n': /* Got newline before closing ']'. */
271 i = Continuation( buf->data, i ); /* Check for line continuation. */
272 if( i < 0 ) {
273 buf->data[end] = '\0';
274 DEBUG(0, ("%s Badly formed line in configuration file: %s\n", func, buf->data ));
275 return False;
276 }
277 end = ( (i > 0) && (' ' == buf->data[i - 1]) ) ? (i - 1) : (i);
278 c = mygetc( InFile ); /* Continue with next line. */
279 break;
280
281 default: /* All else are a valid name chars. */
282 if(isspace( c )) {
283 /* One space per whitespace region. */
284 buf->data[end] = ' ';
285 i = end + 1;
286 c = EatWhitespace( InFile );
287 } else {
288 buf->data[i++] = c;
289 end = i;
290 c = mygetc( InFile );
291 }
292 }
293
294 if (AtSectionEnd(InFile)) {
295 /* Got to the closing bracket. */
296 buf->data[end] = '\0';
297 if( 0 == end ) {
298 /* Don't allow an empty name. */
299 DEBUG(0, ("%s Empty section name in configuration file.\n", func ));
300 return False;
301 }
302 if( !sfunc((char *)buf->data, userdata) ) /* Got a valid name. Deal with it. */
303 return False;
304 EatComment( InFile ); /* Finish off the line. */
305 return True;
306 }
307
308 }
309
310 /* We arrive here if we've met the EOF before the closing bracket. */
311 DEBUG(0, ("%s Unexpected EOF in the configuration file: %s\n", func, buf->data ));
312 return False;
313}
314
315/* ------------------------------------------------------------------------ **
316 * Scan a parameter name and value, and pass these two fields to pfunc().
317 *
318 * Input: InFile - The input source.
319 * pfunc - A pointer to the function that will be called to
320 * process the parameter, once it has been scanned.
321 * c - The first character of the parameter name, which
322 * would have been read by Parse(). Unlike a comment
323 * line or a section header, there is no lead-in
324 * character that can be discarded.
325 *
326 * Output: True if the parameter name and value were scanned and processed
327 * successfully, else False.
328 *
329 * Notes: This function is in two parts. The first loop scans the
330 * parameter name. Internal whitespace is compressed, and an
331 * equal sign (=) terminates the token. Leading and trailing
332 * whitespace is discarded. The second loop scans the parameter
333 * value. When both have been successfully identified, they are
334 * passed to pfunc() for processing.
335 *
336 * ------------------------------------------------------------------------ **
337 */
338
339static bool Parameter( DATA_BLOB *buf, myFILE *InFile, bool (*pfunc)(const char *, const char *, void *), int c, void *userdata )
340{
341 int i = 0; /* Position within bufr. */
342 int end = 0; /* bufr[end] is current end-of-string. */
343 int vstart = 0; /* Starting position of the parameter value. */
344 const char *func = "params.c:Parameter() -";
345
346 /* Read the parameter name. */
347 while( 0 == vstart ) {
348 /* Loop until we've found the start of the value. */
349 if( i > (buf->length - 2) ) {
350 /* Ensure there's space for next char. */
351 uint8_t *tb = (uint8_t *)SMB_REALLOC_KEEP_OLD_ON_ERROR( buf->data, buf->length + BUFR_INC );
352 if (!tb) {
353 DEBUG(0, ("%s Memory re-allocation failure.", func) );
354 return False;
355 }
356 buf->data = tb;
357 buf->length += BUFR_INC;
358 }
359
360 switch(c) {
361 case '=': /* Equal sign marks end of param name. */
362 if( 0 == end ) {
363 /* Don't allow an empty name. */
364 DEBUG(0, ("%s Invalid parameter name in config. file.\n", func ));
365 return False;
366 }
367 buf->data[end++] = '\0'; /* Mark end of string & advance. */
368 i = end; /* New string starts here. */
369 vstart = end; /* New string is parameter value. */
370 buf->data[i] = '\0'; /* New string is nul, for now. */
371 break;
372
373 case '\n': /* Find continuation char, else error. */
374 i = Continuation( buf->data, i );
375 if( i < 0 ) {
376 buf->data[end] = '\0';
377 DEBUG(1,("%s Ignoring badly formed line in configuration file: %s\n", func, buf->data ));
378 return True;
379 }
380 end = ( (i > 0) && (' ' == buf->data[i - 1]) ) ? (i - 1) : (i);
381 c = mygetc( InFile ); /* Read past eoln. */
382 break;
383
384 case '\0': /* Shouldn't have EOF within param name. */
385 case EOF:
386 buf->data[i] = '\0';
387 DEBUG(1,("%s Unexpected end-of-file at: %s\n", func, buf->data ));
388 return True;
389
390 default:
391 if(isspace( c )) {
392 /* One ' ' per whitespace region. */
393 buf->data[end] = ' ';
394 i = end + 1;
395 c = EatWhitespace( InFile );
396 } else {
397 buf->data[i++] = c;
398 end = i;
399 c = mygetc( InFile );
400 }
401 }
402 }
403
404 /* Now parse the value. */
405 c = EatWhitespace( InFile ); /* Again, trim leading whitespace. */
406 while( (EOF !=c) && (c > 0) ) {
407 if( i > (buf->length - 2) ) {
408 /* Make sure there's enough room. */
409 uint8_t *tb = (uint8_t *)SMB_REALLOC_KEEP_OLD_ON_ERROR( buf->data, buf->length + BUFR_INC );
410 if (!tb) {
411 DEBUG(0, ("%s Memory re-allocation failure.", func));
412 return False;
413 }
414 buf->data = tb;
415 buf->length += BUFR_INC;
416 }
417
418 switch(c) {
419 case '\r': /* Explicitly remove '\r' because the older */
420 c = mygetc( InFile ); /* version called fgets_slash() which also */
421 break; /* removes them. */
422
423 case '\n': /* Marks end of value unless there's a '\'. */
424 i = Continuation( buf->data, i );
425 if( i < 0 ) {
426 c = 0;
427 } else {
428 for( end = i; (end >= 0) && isspace((int)buf->data[end]); end-- )
429 ;
430 c = mygetc( InFile );
431 }
432 break;
433
434 default: /* All others verbatim. Note that spaces do not advance <end>. This allows trimming */
435 buf->data[i++] = c;
436 if( !isspace( c ) ) /* of whitespace at the end of the line. */
437 end = i;
438 c = mygetc( InFile );
439 break;
440 }
441 }
442 buf->data[end] = '\0'; /* End of value. */
443
444 return( pfunc( (char *)buf->data, (char *)&buf->data[vstart], userdata ) ); /* Pass name & value to pfunc(). */
445}
446
447/* ------------------------------------------------------------------------ **
448 * Scan & parse the input.
449 *
450 * Input: InFile - Input source.
451 * sfunc - Function to be called when a section name is scanned.
452 * See Section().
453 * pfunc - Function to be called when a parameter is scanned.
454 * See Parameter().
455 *
456 * Output: True if the file was successfully scanned, else False.
457 *
458 * Notes: The input can be viewed in terms of 'lines'. There are four
459 * types of lines:
460 * Blank - May contain whitespace, otherwise empty.
461 * Comment - First non-whitespace character is a ';' or '#'.
462 * The remainder of the line is ignored.
463 * Section - First non-whitespace character is a '['.
464 * Parameter - The default case.
465 *
466 * ------------------------------------------------------------------------ **
467 */
468
469static bool Parse( DATA_BLOB *buf, myFILE *InFile,
470 bool (*sfunc)(const char *, void *),
471 bool (*pfunc)(const char *, const char *, void *),
472 void *userdata)
473{
474 int c;
475
476 c = EatWhitespace( InFile );
477 while( (EOF != c) && (c > 0) ) {
478 switch( c ) {
479 case '\n': /* Blank line. */
480 c = EatWhitespace( InFile );
481 break;
482
483 case ';': /* Comment line. */
484 case '#':
485 c = EatComment( InFile );
486 break;
487
488 case '[': /* Section Header. */
489 if( !Section( buf, InFile, sfunc, userdata ) )
490 return False;
491 c = EatWhitespace( InFile );
492 break;
493
494 case '\\': /* Bogus backslash. */
495 c = EatWhitespace( InFile );
496 break;
497
498 default: /* Parameter line. */
499 if( !Parameter( buf, InFile, pfunc, c, userdata ) )
500 return False;
501 c = EatWhitespace( InFile );
502 break;
503 }
504 }
505 return True;
506}
507
508/* ------------------------------------------------------------------------ **
509 * Open a configuration file.
510 *
511 * Input: FileName - The pathname of the config file to be opened.
512 *
513 * Output: A pointer of type (char **) to the lines of the file
514 *
515 * ------------------------------------------------------------------------ **
516 */
517
518static myFILE *OpenConfFile( const char *FileName )
519{
520 const char *func = "params.c:OpenConfFile() -";
521 int lvl = lp_is_in_client() ? 1 : 0;
522 myFILE *ret;
523
524 ret = SMB_MALLOC_P(myFILE);
525 if (!ret)
526 return NULL;
527
528 ret->buf = file_load(FileName, &ret->size, 0);
529 if( NULL == ret->buf ) {
530 DEBUG( lvl, ("%s Unable to open configuration file \"%s\":\n\t%s\n",
531 func, FileName, strerror(errno)) );
532 SAFE_FREE(ret);
533 return NULL;
534 }
535
536 ret->p = ret->buf;
537 ret->end_section_p = NULL;
538 return( ret );
539}
540
541/* ------------------------------------------------------------------------ **
542 * Process the named parameter file.
543 *
544 * Input: FileName - The pathname of the parameter file to be opened.
545 * sfunc - A pointer to a function that will be called when
546 * a section name is discovered.
547 * pfunc - A pointer to a function that will be called when
548 * a parameter name and value are discovered.
549 *
550 * Output: TRUE if the file was successfully parsed, else FALSE.
551 *
552 * ------------------------------------------------------------------------ **
553 */
554
555bool pm_process( const char *FileName,
556 bool (*sfunc)(const char *, void *),
557 bool (*pfunc)(const char *, const char *, void *),
558 void *userdata)
559{
560 int result;
561 myFILE *InFile;
562 const char *func = "params.c:pm_process() -";
563 DATA_BLOB buf;
564
565 InFile = OpenConfFile( FileName ); /* Open the config file. */
566 if( NULL == InFile )
567 return False;
568
569 DEBUG( 3, ("%s Processing configuration file \"%s\"\n", func, FileName) );
570
571 buf = data_blob(NULL, 256);
572
573 if (buf.data == NULL) {
574 DEBUG(0,("%s memory allocation failure.\n", func));
575 myfile_close(InFile);
576 return False;
577 }
578
579 result = Parse( &buf, InFile, sfunc, pfunc, userdata );
580 data_blob_free(&buf);
581
582 myfile_close(InFile);
583
584 if( !result ) {
585 DEBUG(0,("%s Failed. Error returned from params.c:parse().\n", func));
586 return False;
587 }
588
589 return True;
590}
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