1 /* Handle configuration data.
2 Copyright (C) 1997-2020 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
28 #include <stdio_ext.h>
32 #include <sys/param.h>
34 #include <libc-lock.h>
35 #include <gconv_int.h>
38 /* This is the default path where we look for module lists. */
39 static const char default_gconv_path
[] = GCONV_PATH
;
41 /* Type to represent search path. */
48 /* The path elements, as determined by the __gconv_get_path function.
49 All path elements end in a slash. */
50 struct path_elem
*__gconv_path_elem
;
51 /* Maximum length of a single path element in __gconv_path_elem. */
52 size_t __gconv_max_path_elem_len
;
54 /* We use the following struct if we couldn't allocate memory. */
55 static const struct path_elem empty_path_elem
= { NULL
, 0 };
57 /* Name of the file containing the module information in the directories
59 static const char gconv_conf_filename
[] = "gconv-modules";
61 /* Filename extension for the modules. */
63 # define MODULE_EXT ".so"
65 static const char gconv_module_ext
[] = MODULE_EXT
;
67 /* We have a few builtin transformations. */
68 static struct gconv_module builtin_modules
[] =
70 #define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, BtowcFct, \
71 MinF, MaxF, MinT, MaxT) \
73 .from_string = From, \
79 #define BUILTIN_ALIAS(From, To)
81 #include "gconv_builtin.h"
83 #undef BUILTIN_TRANSFORMATION
87 static const char builtin_aliases
[] =
89 #define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, BtowcFct, \
90 MinF, MaxF, MinT, MaxT)
91 #define BUILTIN_ALIAS(From, To) From "\0" To "\0"
93 #include "gconv_builtin.h"
95 #undef BUILTIN_TRANSFORMATION
99 #include <libio/libioP.h>
100 #define __getdelim(line, len, c, fp) _IO_getdelim (line, len, c, fp)
103 /* Value of the GCONV_PATH environment variable. */
104 const char *__gconv_path_envvar
;
107 /* Test whether there is already a matching module known. */
109 detect_conflict (const char *alias
)
111 struct gconv_module
*node
= __gconv_modules_db
;
115 int cmpres
= strcmp (alias
, node
->from_string
);
118 /* We have a conflict. */
130 /* The actual code to add aliases. */
132 add_alias2 (const char *from
, const char *to
, const char *wp
, void *modules
)
134 /* Test whether this alias conflicts with any available module. */
135 if (detect_conflict (from
))
136 /* It does conflict, don't add the alias. */
139 struct gconv_alias
*new_alias
= (struct gconv_alias
*)
140 malloc (sizeof (struct gconv_alias
) + (wp
- from
));
141 if (new_alias
!= NULL
)
145 new_alias
->fromname
= memcpy ((char *) new_alias
146 + sizeof (struct gconv_alias
),
148 new_alias
->toname
= new_alias
->fromname
+ (to
- from
);
150 inserted
= (void **) __tsearch (new_alias
, &__gconv_alias_db
,
151 __gconv_alias_compare
);
152 if (inserted
== NULL
|| *inserted
!= new_alias
)
153 /* Something went wrong, free this entry. */
161 add_alias (char *rp
, void *modules
)
163 /* We now expect two more string. The strings are normalized
164 (converted to UPPER case) and strored in the alias database. */
165 char *from
, *to
, *wp
;
167 while (__isspace_l (*rp
, _nl_C_locobj_ptr
))
170 while (*rp
!= '\0' && !__isspace_l (*rp
, _nl_C_locobj_ptr
))
171 *wp
++ = __toupper_l (*rp
++, _nl_C_locobj_ptr
);
173 /* There is no `to' string on the line. Ignore it. */
177 while (__isspace_l (*rp
, _nl_C_locobj_ptr
))
179 while (*rp
!= '\0' && !__isspace_l (*rp
, _nl_C_locobj_ptr
))
180 *wp
++ = __toupper_l (*rp
++, _nl_C_locobj_ptr
);
182 /* No `to' string, ignore the line. */
186 add_alias2 (from
, to
, wp
, modules
);
190 /* Insert a data structure for a new module in the search tree. */
192 insert_module (struct gconv_module
*newp
, int tobefreed
)
194 struct gconv_module
**rootp
= &__gconv_modules_db
;
196 while (*rootp
!= NULL
)
198 struct gconv_module
*root
= *rootp
;
201 cmpres
= strcmp (newp
->from_string
, root
->from_string
);
204 /* Both strings are identical. Insert the string at the
205 end of the `same' list if it is not already there. */
206 while (strcmp (newp
->from_string
, root
->from_string
) != 0
207 || strcmp (newp
->to_string
, root
->to_string
) != 0)
217 /* This is a no new conversion. But maybe the cost is
219 if (newp
->cost_hi
< root
->cost_hi
220 || (newp
->cost_hi
== root
->cost_hi
221 && newp
->cost_lo
< root
->cost_lo
))
223 newp
->left
= root
->left
;
224 newp
->right
= root
->right
;
225 newp
->same
= root
->same
;
240 rootp
= &root
->right
;
243 /* Plug in the new node here. */
248 /* Add new module. */
250 add_module (char *rp
, const char *directory
, size_t dir_len
, void **modules
,
251 size_t *nmodules
, int modcounter
)
256 3. filename of the module
257 4. an optional cost value
259 struct gconv_alias fake_alias
;
260 struct gconv_module
*new_module
;
261 char *from
, *to
, *module
, *wp
;
265 while (__isspace_l (*rp
, _nl_C_locobj_ptr
))
268 while (*rp
!= '\0' && !__isspace_l (*rp
, _nl_C_locobj_ptr
))
270 *rp
= __toupper_l (*rp
, _nl_C_locobj_ptr
);
277 while (__isspace_l (*rp
, _nl_C_locobj_ptr
))
279 while (*rp
!= '\0' && !__isspace_l (*rp
, _nl_C_locobj_ptr
))
280 *wp
++ = __toupper_l (*rp
++, _nl_C_locobj_ptr
);
286 while (__isspace_l (*rp
, _nl_C_locobj_ptr
));
288 while (*rp
!= '\0' && !__isspace_l (*rp
, _nl_C_locobj_ptr
))
292 /* There is no cost, use one by default. */
298 /* There might be a cost value. */
302 cost_hi
= strtol (rp
, &endp
, 10);
303 if (rp
== endp
|| cost_hi
< 1)
304 /* No useful information. */
308 if (module
[0] == '\0')
309 /* No module name given. */
311 if (module
[0] == '/')
314 /* See whether we must add the ending. */
316 if (wp
- module
< (ptrdiff_t) sizeof (gconv_module_ext
)
317 || memcmp (wp
- sizeof (gconv_module_ext
), gconv_module_ext
,
318 sizeof (gconv_module_ext
)) != 0)
319 /* We must add the module extension. */
320 need_ext
= sizeof (gconv_module_ext
) - 1;
322 /* See whether we have already an alias with this name defined. */
323 fake_alias
.fromname
= strndupa (from
, to
- from
);
325 if (__tfind (&fake_alias
, &__gconv_alias_db
, __gconv_alias_compare
) != NULL
)
326 /* This module duplicates an alias. */
329 new_module
= (struct gconv_module
*) calloc (1,
330 sizeof (struct gconv_module
)
332 + dir_len
+ need_ext
);
333 if (new_module
!= NULL
)
337 new_module
->from_string
= tmp
= (char *) (new_module
+ 1);
338 tmp
= __mempcpy (tmp
, from
, to
- from
);
340 new_module
->to_string
= tmp
;
341 tmp
= __mempcpy (tmp
, to
, module
- to
);
343 new_module
->cost_hi
= cost_hi
;
344 new_module
->cost_lo
= modcounter
;
346 new_module
->module_name
= tmp
;
349 tmp
= __mempcpy (tmp
, directory
, dir_len
);
351 tmp
= __mempcpy (tmp
, module
, wp
- module
);
354 memcpy (tmp
- 1, gconv_module_ext
, sizeof (gconv_module_ext
));
356 /* Now insert the new module data structure in our search tree. */
357 insert_module (new_module
, 1);
362 /* Read the next configuration file. */
364 read_conf_file (const char *filename
, const char *directory
, size_t dir_len
,
365 void **modules
, size_t *nmodules
)
367 /* Note the file is opened with cancellation in the I/O functions
369 FILE *fp
= fopen (filename
, "rce");
372 static int modcounter
;
374 /* Don't complain if a file is not present or readable, simply silently
379 /* No threads reading from this stream. */
380 __fsetlocking (fp
, FSETLOCKING_BYCALLER
);
382 /* Process the known entries of the file. Comments start with `#' and
383 end with the end of the line. Empty lines are ignored. */
384 while (!__feof_unlocked (fp
))
386 char *rp
, *endp
, *word
;
387 ssize_t n
= __getdelim (&line
, &line_len
, '\n', fp
);
389 /* An error occurred. */
393 /* Terminate the line (excluding comments or newline) by an NUL byte
394 to simplify the following code. */
395 endp
= strchr (rp
, '#');
399 if (rp
[n
- 1] == '\n')
402 while (__isspace_l (*rp
, _nl_C_locobj_ptr
))
405 /* If this is an empty line go on with the next one. */
410 while (*rp
!= '\0' && !__isspace_l (*rp
, _nl_C_locobj_ptr
))
413 if (rp
- word
== sizeof ("alias") - 1
414 && memcmp (word
, "alias", sizeof ("alias") - 1) == 0)
415 add_alias (rp
, *modules
);
416 else if (rp
- word
== sizeof ("module") - 1
417 && memcmp (word
, "module", sizeof ("module") - 1) == 0)
418 add_module (rp
, directory
, dir_len
, modules
, nmodules
, modcounter
++);
420 /* Otherwise ignore the line. */
429 /* Determine the directories we are looking for data in. This function should
430 only be called from __gconv_read_conf. */
432 __gconv_get_path (void)
434 struct path_elem
*result
;
436 /* This function is only ever called when __gconv_path_elem is NULL. */
437 result
= __gconv_path_elem
;
438 assert (result
== NULL
);
440 /* Determine the complete path first. */
442 size_t gconv_path_len
;
450 if (__gconv_path_envvar
== NULL
)
452 /* No user-defined path. Make a modifiable copy of the
454 gconv_path
= strdupa (default_gconv_path
);
455 gconv_path_len
= sizeof (default_gconv_path
);
461 /* Append the default path to the user-defined path. */
462 size_t user_len
= strlen (__gconv_path_envvar
);
464 gconv_path_len
= user_len
+ 1 + sizeof (default_gconv_path
);
465 gconv_path
= alloca (gconv_path_len
);
466 __mempcpy (__mempcpy (__mempcpy (gconv_path
, __gconv_path_envvar
,
469 default_gconv_path
, sizeof (default_gconv_path
));
470 cwd
= __getcwd (NULL
, 0);
471 cwdlen
= __glibc_unlikely (cwd
== NULL
) ? 0 : strlen (cwd
);
473 assert (default_gconv_path
[0] == '/');
475 /* In a first pass we calculate the number of elements. */
477 cp
= strchr (gconv_path
, ':');
484 cp
= strchr (cp
+ 1, ':');
487 /* Allocate the memory for the result. */
488 result
= malloc ((nelems
+ 1)
489 * sizeof (struct path_elem
)
490 + gconv_path_len
+ nelems
491 + (nelems
- 1) * (cwdlen
+ 1));
494 char *strspace
= (char *) &result
[nelems
+ 1];
497 /* Separate the individual parts. */
498 __gconv_max_path_elem_len
= 0;
499 elem
= __strtok_r (gconv_path
, ":", &gconv_path
);
500 assert (elem
!= NULL
);
503 result
[n
].name
= strspace
;
506 assert (cwd
!= NULL
);
507 strspace
= __mempcpy (strspace
, cwd
, cwdlen
);
510 strspace
= __stpcpy (strspace
, elem
);
511 if (strspace
[-1] != '/')
514 result
[n
].len
= strspace
- result
[n
].name
;
515 if (result
[n
].len
> __gconv_max_path_elem_len
)
516 __gconv_max_path_elem_len
= result
[n
].len
;
521 while ((elem
= __strtok_r (NULL
, ":", &gconv_path
)) != NULL
);
523 result
[n
].name
= NULL
;
527 __gconv_path_elem
= result
?: (struct path_elem
*) &empty_path_elem
;
533 /* Read all configuration files found in the user-specified and the default
534 path. This function should only be called once during the program's
535 lifetime. It disregards locking and synchronization because its only
536 caller, __gconv_load_conf, handles this. */
538 __gconv_read_conf (void)
540 void *modules
= NULL
;
542 int save_errno
= errno
;
545 /* First see whether we should use the cache. */
546 if (__gconv_load_cache () == 0)
548 /* Yes, we are done. */
549 __set_errno (save_errno
);
554 /* Find out where we have to look. */
557 for (cnt
= 0; __gconv_path_elem
[cnt
].name
!= NULL
; ++cnt
)
559 const char *elem
= __gconv_path_elem
[cnt
].name
;
560 size_t elem_len
= __gconv_path_elem
[cnt
].len
;
563 /* No slash needs to be inserted between elem and gconv_conf_filename;
564 elem already ends in a slash. */
565 filename
= alloca (elem_len
+ sizeof (gconv_conf_filename
));
566 __mempcpy (__mempcpy (filename
, elem
, elem_len
),
567 gconv_conf_filename
, sizeof (gconv_conf_filename
));
569 /* Read the next configuration file. */
570 read_conf_file (filename
, elem
, elem_len
, &modules
, &nmodules
);
574 /* Add the internal modules. */
575 for (cnt
= 0; cnt
< sizeof (builtin_modules
) / sizeof (builtin_modules
[0]);
578 struct gconv_alias fake_alias
;
580 fake_alias
.fromname
= (char *) builtin_modules
[cnt
].from_string
;
582 if (__tfind (&fake_alias
, &__gconv_alias_db
, __gconv_alias_compare
)
584 /* It'll conflict so don't add it. */
587 insert_module (&builtin_modules
[cnt
], 0);
590 /* Add aliases for builtin conversions. */
591 const char *cp
= builtin_aliases
;
594 const char *from
= cp
;
595 const char *to
= __rawmemchr (from
, '\0') + 1;
596 cp
= __rawmemchr (to
, '\0') + 1;
598 add_alias2 (from
, to
, cp
, modules
);
602 /* Restore the error number. */
603 __set_errno (save_errno
);
607 /* This "once" variable is used to do a one-time load of the configuration. */
608 __libc_once_define (static, once
);
611 /* Read all configuration files found in the user-specified and the default
612 path, but do it only "once" using __gconv_read_conf to do the actual
613 work. This is the function that must be called when reading iconv
616 __gconv_load_conf (void)
618 __libc_once (once
, __gconv_read_conf
);
622 /* Free all resources if necessary. */
623 libc_freeres_fn (free_mem
)
625 if (__gconv_path_elem
!= NULL
&& __gconv_path_elem
!= &empty_path_elem
)
626 free ((void *) __gconv_path_elem
);