xref: /freebsd/contrib/ncurses/form/fty_regex.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /****************************************************************************
2  * Copyright 2018,2020 Thomas E. Dickey                                     *
3  * Copyright 1998-2012,2015 Free Software Foundation, Inc.                  *
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29 
30 /***************************************************************************
31 *                                                                          *
32 *  Author : Juergen Pfeifer                                                *
33 *                                                                          *
34 ***************************************************************************/
35 
36 #include "form.priv.h"
37 
38 MODULE_ID("$Id: fty_regex.c,v 1.32 2020/12/12 01:15:37 tom Exp $")
39 
40 #if HAVE_REGEX_H_FUNCS || HAVE_LIB_PCRE2	/* We prefer POSIX regex */
41 
42 #if HAVE_PCRE2POSIX_H
43 #include <pcre2posix.h>
44 #elif HAVE_PCREPOSIX_H
45 #include <pcreposix.h>
46 #else
47 #include <regex.h>
48 #endif
49 
50 typedef struct
51   {
52     regex_t *pRegExp;
53     unsigned long *refCount;
54   }
55 RegExp_Arg;
56 
57 #elif HAVE_REGEXP_H_FUNCS | HAVE_REGEXPR_H_FUNCS
58 #undef RETURN
59 static int reg_errno;
60 
61 static char *
62 RegEx_Init(char *instring)
63 {
64   reg_errno = 0;
65   return instring;
66 }
67 
68 static char *
69 RegEx_Error(int code)
70 {
71   reg_errno = code;
72   return 0;
73 }
74 
75 #define INIT 		register char *sp = RegEx_Init(instring);
76 #define GETC()		(*sp++)
77 #define PEEKC()		(*sp)
78 #define UNGETC(c)	(--sp)
79 #define RETURN(c)	return(c)
80 #define ERROR(c)	return RegEx_Error(c)
81 
82 #if HAVE_REGEXP_H_FUNCS
83 #include <regexp.h>
84 #else
85 #include <regexpr.h>
86 #endif
87 
88 typedef struct
89 {
90   char *compiled_expression;
91   unsigned long *refCount;
92 }
93 RegExp_Arg;
94 
95 /* Maximum Length we allow for a compiled regular expression */
96 #define MAX_RX_LEN   (2048)
97 #define RX_INCREMENT (256)
98 
99 #endif
100 
101 #if HAVE_REGEX_H_FUNCS | HAVE_REGEXP_H_FUNCS | HAVE_REGEXPR_H_FUNCS
102 # define MAYBE_UNUSED
103 #else
104 # define MAYBE_UNUSED GCC_UNUSED
105 #endif
106 
107 /*---------------------------------------------------------------------------
108 |   Facility      :  libnform
109 |   Function      :  static void *Generic_RegularExpression_Type(void * arg)
110 |
111 |   Description   :  Allocate structure for regex type argument.
112 |
113 |   Return Values :  Pointer to argument structure or NULL on error
114 +--------------------------------------------------------------------------*/
115 static void *
116 Generic_RegularExpression_Type(void *arg MAYBE_UNUSED)
117 {
118 #if HAVE_REGEX_H_FUNCS
119   char *rx = (char *)arg;
120   RegExp_Arg *preg = (RegExp_Arg *)0;
121 
122   if (rx)
123     {
124       preg = typeCalloc(RegExp_Arg, 1);
125 
126       if (preg)
127 	{
128 	  T((T_CREATE("RegExp_Arg %p"), (void *)preg));
129 	  if (((preg->pRegExp = typeMalloc(regex_t, 1)) != 0)
130 	      && !regcomp(preg->pRegExp, rx,
131 			  (REG_EXTENDED | REG_NOSUB | REG_NEWLINE)))
132 	    {
133 	      T((T_CREATE("regex_t %p"), (void *)preg->pRegExp));
134 	      if ((preg->refCount = typeMalloc(unsigned long, 1)) != 0)
135 		 *(preg->refCount) = 1;
136 	    }
137 	  else
138 	    {
139 	      if (preg->pRegExp)
140 		free(preg->pRegExp);
141 	      free(preg);
142 	      preg = (RegExp_Arg *)0;
143 	    }
144 	}
145     }
146   return ((void *)preg);
147 #elif HAVE_REGEXP_H_FUNCS | HAVE_REGEXPR_H_FUNCS
148   char *rx = (char *)arg;
149   RegExp_Arg *pArg = (RegExp_Arg *)0;
150 
151   if (rx)
152     {
153       pArg = typeMalloc(RegExp_Arg, 1);
154 
155       if (pArg)
156 	{
157 	  int blen = RX_INCREMENT;
158 
159 	  T((T_CREATE("RegExp_Arg %p"), pArg));
160 	  pArg->compiled_expression = NULL;
161 	  if ((pArg->refCount = typeMalloc(unsigned long, 1)) != 0)
162 	     *(pArg->refCount) = 1;
163 
164 	  do
165 	    {
166 	      char *buf = typeMalloc(char, blen);
167 
168 	      if (buf)
169 		{
170 #if HAVE_REGEXP_H_FUNCS
171 		  char *last_pos = compile(rx, buf, &buf[blen], '\0');
172 
173 #else /* HAVE_REGEXPR_H_FUNCS */
174 		  char *last_pos = compile(rx, buf, &buf[blen]);
175 #endif
176 		  if (reg_errno)
177 		    {
178 		      free(buf);
179 		      if (reg_errno == 50)
180 			blen += RX_INCREMENT;
181 		      else
182 			{
183 			  free(pArg);
184 			  pArg = NULL;
185 			  break;
186 			}
187 		    }
188 		  else
189 		    {
190 		      pArg->compiled_expression = buf;
191 		      break;
192 		    }
193 		}
194 	    }
195 	  while (blen <= MAX_RX_LEN);
196 	}
197       if (pArg && !pArg->compiled_expression)
198 	{
199 	  free(pArg);
200 	  pArg = NULL;
201 	}
202     }
203   return (void *)pArg;
204 #else
205   return 0;
206 #endif
207 }
208 
209 /*---------------------------------------------------------------------------
210 |   Facility      :  libnform
211 |   Function      :  static void *Make_RegularExpression_Type(va_list * ap)
212 |
213 |   Description   :  Allocate structure for regex type argument.
214 |
215 |   Return Values :  Pointer to argument structure or NULL on error
216 +--------------------------------------------------------------------------*/
217 static void *
218 Make_RegularExpression_Type(va_list *ap)
219 {
220   char *rx = va_arg(*ap, char *);
221 
222   return Generic_RegularExpression_Type((void *)rx);
223 }
224 
225 /*---------------------------------------------------------------------------
226 |   Facility      :  libnform
227 |   Function      :  static void *Copy_RegularExpression_Type(
228 |                                      const void * argp)
229 |
230 |   Description   :  Copy structure for regex type argument.
231 |
232 |   Return Values :  Pointer to argument structure or NULL on error.
233 +--------------------------------------------------------------------------*/
234 static void *
235 Copy_RegularExpression_Type(const void *argp MAYBE_UNUSED)
236 {
237 #if (HAVE_REGEX_H_FUNCS | HAVE_REGEXP_H_FUNCS | HAVE_REGEXPR_H_FUNCS)
238   const RegExp_Arg *ap = (const RegExp_Arg *)argp;
239   const RegExp_Arg *result = (const RegExp_Arg *)0;
240 
241   if (ap)
242     {
243       *(ap->refCount) += 1;
244       result = ap;
245     }
246   return (void *)result;
247 #else
248   return 0;
249 #endif
250 }
251 
252 /*---------------------------------------------------------------------------
253 |   Facility      :  libnform
254 |   Function      :  static void Free_RegularExpression_Type(void * argp)
255 |
256 |   Description   :  Free structure for regex type argument.
257 |
258 |   Return Values :  -
259 +--------------------------------------------------------------------------*/
260 static void
261 Free_RegularExpression_Type(void *argp MAYBE_UNUSED)
262 {
263 #if HAVE_REGEX_H_FUNCS | HAVE_REGEXP_H_FUNCS | HAVE_REGEXPR_H_FUNCS
264   RegExp_Arg *ap = (RegExp_Arg *)argp;
265 
266   if (ap)
267     {
268       if (--(*(ap->refCount)) == 0)
269 	{
270 #if HAVE_REGEX_H_FUNCS
271 	  if (ap->pRegExp)
272 	    {
273 	      free(ap->refCount);
274 	      regfree(ap->pRegExp);
275 	      free(ap->pRegExp);
276 	    }
277 #elif HAVE_REGEXP_H_FUNCS | HAVE_REGEXPR_H_FUNCS
278 	  if (ap->compiled_expression)
279 	    {
280 	      free(ap->refCount);
281 	      free(ap->compiled_expression);
282 	    }
283 #endif
284 	  free(ap);
285 	}
286     }
287 #endif
288 }
289 
290 /*---------------------------------------------------------------------------
291 |   Facility      :  libnform
292 |   Function      :  static bool Check_RegularExpression_Field(
293 |                                      FIELD * field,
294 |                                      const void  * argp)
295 |
296 |   Description   :  Validate buffer content to be a valid regular expression
297 |
298 |   Return Values :  TRUE  - field is valid
299 |                    FALSE - field is invalid
300 +--------------------------------------------------------------------------*/
301 static bool
302 Check_RegularExpression_Field(FIELD *field MAYBE_UNUSED,
303 			      const void *argp MAYBE_UNUSED)
304 {
305   bool match = FALSE;
306 
307 #if HAVE_REGEX_H_FUNCS
308   const RegExp_Arg *ap = (const RegExp_Arg *)argp;
309 
310   if (ap && ap->pRegExp)
311     match = (regexec(ap->pRegExp, field_buffer(field, 0), 0, NULL, 0)
312 	     ? FALSE
313 	     : TRUE);
314 #elif HAVE_REGEXP_H_FUNCS | HAVE_REGEXPR_H_FUNCS
315   RegExp_Arg *ap = (RegExp_Arg *)argp;
316 
317   if (ap && ap->compiled_expression)
318     match = (step(field_buffer(field, 0), ap->compiled_expression)
319 	     ? TRUE
320 	     : FALSE);
321 #endif
322   return match;
323 }
324 
325 static FIELDTYPE typeREGEXP =
326 {
327   _HAS_ARGS | _RESIDENT,
328   1,				/* this is mutable, so we can't be const */
329   (FIELDTYPE *)0,
330   (FIELDTYPE *)0,
331   Make_RegularExpression_Type,
332   Copy_RegularExpression_Type,
333   Free_RegularExpression_Type,
334   INIT_FT_FUNC(Check_RegularExpression_Field),
335   INIT_FT_FUNC(NULL),
336   INIT_FT_FUNC(NULL),
337   INIT_FT_FUNC(NULL),
338 #if NCURSES_INTEROP_FUNCS
339   Generic_RegularExpression_Type
340 #endif
341 };
342 
343 FORM_EXPORT_VAR(FIELDTYPE *) TYPE_REGEXP = &typeREGEXP;
344 
345 #if NCURSES_INTEROP_FUNCS
346 /* The next routines are to simplify the use of ncurses from
347    programming languages with restrictions on interop with C level
348    constructs (e.g. variable access or va_list + ellipsis constructs)
349 */
350 FORM_EXPORT(FIELDTYPE *)
351 _nc_TYPE_REGEXP(void)
352 {
353   return TYPE_REGEXP;
354 }
355 #endif
356 
357 /* fty_regex.c ends here */
358