/* Handle configuration data. Copyright (C) 1997-2016 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 1997. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* This is the default path where we look for module lists. */ static const char default_gconv_path[] = GCONV_PATH; /* The path elements, as determined by the __gconv_get_path function. All path elements end in a slash. */ struct path_elem *__gconv_path_elem; /* Maximum length of a single path element in __gconv_path_elem. */ size_t __gconv_max_path_elem_len; /* We use the following struct if we couldn't allocate memory. */ static const struct path_elem empty_path_elem = { NULL, 0 }; /* Name of the file containing the module information in the directories along the path. */ static const char gconv_conf_filename[] = "gconv-modules"; /* Filename extension for the modules. */ #ifndef MODULE_EXT # define MODULE_EXT ".so" #endif static const char gconv_module_ext[] = MODULE_EXT; /* We have a few builtin transformations. */ static struct gconv_module builtin_modules[] = { #define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, BtowcFct, \ MinF, MaxF, MinT, MaxT) \ { \ .from_string = From, \ .to_string = To, \ .cost_hi = Cost, \ .cost_lo = INT_MAX, \ .module_name = Name \ }, #define BUILTIN_ALIAS(From, To) #include "gconv_builtin.h" #undef BUILTIN_TRANSFORMATION #undef BUILTIN_ALIAS }; static const char builtin_aliases[] = { #define BUILTIN_TRANSFORMATION(From, To, Cost, Name, Fct, BtowcFct, \ MinF, MaxF, MinT, MaxT) #define BUILTIN_ALIAS(From, To) From "\0" To "\0" #include "gconv_builtin.h" #undef BUILTIN_TRANSFORMATION #undef BUILTIN_ALIAS }; #include #define __getdelim(line, len, c, fp) _IO_getdelim (line, len, c, fp) /* Value of the GCONV_PATH environment variable. */ const char *__gconv_path_envvar; /* Test whether there is already a matching module known. */ static int internal_function detect_conflict (const char *alias) { struct gconv_module *node = __gconv_modules_db; while (node != NULL) { int cmpres = strcmp (alias, node->from_string); if (cmpres == 0) /* We have a conflict. */ return 1; else if (cmpres < 0) node = node->left; else node = node->right; } return node != NULL; } /* The actual code to add aliases. */ static void add_alias2 (const char *from, const char *to, const char *wp, void *modules) { /* Test whether this alias conflicts with any available module. */ if (detect_conflict (from)) /* It does conflict, don't add the alias. */ return; struct gconv_alias *new_alias = (struct gconv_alias *) malloc (sizeof (struct gconv_alias) + (wp - from)); if (new_alias != NULL) { void **inserted; new_alias->fromname = memcpy ((char *) new_alias + sizeof (struct gconv_alias), from, wp - from); new_alias->toname = new_alias->fromname + (to - from); inserted = (void **) __tsearch (new_alias, &__gconv_alias_db, __gconv_alias_compare); if (inserted == NULL || *inserted != new_alias) /* Something went wrong, free this entry. */ free (new_alias); } } /* Add new alias. */ static void add_alias (char *rp, void *modules) { /* We now expect two more string. The strings are normalized (converted to UPPER case) and strored in the alias database. */ char *from, *to, *wp; while (__isspace_l (*rp, _nl_C_locobj_ptr)) ++rp; from = wp = rp; while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr)) *wp++ = __toupper_l (*rp++, _nl_C_locobj_ptr); if (*rp == '\0') /* There is no `to' string on the line. Ignore it. */ return; *wp++ = '\0'; to = ++rp; while (__isspace_l (*rp, _nl_C_locobj_ptr)) ++rp; while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr)) *wp++ = __toupper_l (*rp++, _nl_C_locobj_ptr); if (to == wp) /* No `to' string, ignore the line. */ return; *wp++ = '\0'; add_alias2 (from, to, wp, modules); } /* Insert a data structure for a new module in the search tree. */ static void internal_function insert_module (struct gconv_module *newp, int tobefreed) { struct gconv_module **rootp = &__gconv_modules_db; while (*rootp != NULL) { struct gconv_module *root = *rootp; int cmpres; cmpres = strcmp (newp->from_string, root->from_string); if (cmpres == 0) { /* Both strings are identical. Insert the string at the end of the `same' list if it is not already there. */ while (strcmp (newp->from_string, root->from_string) != 0 || strcmp (newp->to_string, root->to_string) != 0) { rootp = &root->same; root = *rootp; if (root == NULL) break; } if (root != NULL) { /* This is a no new conversion. But maybe the cost is better. */ if (newp->cost_hi < root->cost_hi || (newp->cost_hi == root->cost_hi && newp->cost_lo < root->cost_lo)) { newp->left = root->left; newp->right = root->right; newp->same = root->same; *rootp = newp; free (root); } else if (tobefreed) free (newp); return; } break; } else if (cmpres < 0) rootp = &root->left; else rootp = &root->right; } /* Plug in the new node here. */ *rootp = newp; } /* Add new module. */ static void internal_function add_module (char *rp, const char *directory, size_t dir_len, void **modules, size_t *nmodules, int modcounter) { /* We expect now 1. `from' name 2. `to' name 3. filename of the module 4. an optional cost value */ struct gconv_alias fake_alias; struct gconv_module *new_module; char *from, *to, *module, *wp; int need_ext; int cost_hi; while (__isspace_l (*rp, _nl_C_locobj_ptr)) ++rp; from = rp; while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr)) { *rp = __toupper_l (*rp, _nl_C_locobj_ptr); ++rp; } if (*rp == '\0') return; *rp++ = '\0'; to = wp = rp; while (__isspace_l (*rp, _nl_C_locobj_ptr)) ++rp; while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr)) *wp++ = __toupper_l (*rp++, _nl_C_locobj_ptr); if (*rp == '\0') return; *wp++ = '\0'; do ++rp; while (__isspace_l (*rp, _nl_C_locobj_ptr)); module = wp; while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr)) *wp++ = *rp++; if (*rp == '\0') { /* There is no cost, use one by default. */ *wp++ = '\0'; cost_hi = 1; } else { /* There might be a cost value. */ char *endp; *wp++ = '\0'; cost_hi = strtol (rp, &endp, 10); if (rp == endp || cost_hi < 1) /* No useful information. */ cost_hi = 1; } if (module[0] == '\0') /* No module name given. */ return; if (module[0] == '/') dir_len = 0; /* See whether we must add the ending. */ need_ext = 0; if (wp - module < (ptrdiff_t) sizeof (gconv_module_ext) || memcmp (wp - sizeof (gconv_module_ext), gconv_module_ext, sizeof (gconv_module_ext)) != 0) /* We must add the module extension. */ need_ext = sizeof (gconv_module_ext) - 1; /* See whether we have already an alias with this name defined. */ fake_alias.fromname = strndupa (from, to - from); if (__tfind (&fake_alias, &__gconv_alias_db, __gconv_alias_compare) != NULL) /* This module duplicates an alias. */ return; new_module = (struct gconv_module *) calloc (1, sizeof (struct gconv_module) + (wp - from) + dir_len + need_ext); if (new_module != NULL) { char *tmp; new_module->from_string = tmp = (char *) (new_module + 1); tmp = __mempcpy (tmp, from, to - from); new_module->to_string = tmp; tmp = __mempcpy (tmp, to, module - to); new_module->cost_hi = cost_hi; new_module->cost_lo = modcounter; new_module->module_name = tmp; if (dir_len != 0) tmp = __mempcpy (tmp, directory, dir_len); tmp = __mempcpy (tmp, module, wp - module); if (need_ext) memcpy (tmp - 1, gconv_module_ext, sizeof (gconv_module_ext)); /* Now insert the new module data structure in our search tree. */ insert_module (new_module, 1); } } /* Read the next configuration file. */ static void internal_function read_conf_file (const char *filename, const char *directory, size_t dir_len, void **modules, size_t *nmodules) { /* Note the file is opened with cancellation in the I/O functions disabled. */ FILE *fp = fopen (filename, "rce"); char *line = NULL; size_t line_len = 0; static int modcounter; /* Don't complain if a file is not present or readable, simply silently ignore it. */ if (fp == NULL) return; /* No threads reading from this stream. */ __fsetlocking (fp, FSETLOCKING_BYCALLER); /* Process the known entries of the file. Comments start with `#' and end with the end of the line. Empty lines are ignored. */ while (!feof_unlocked (fp)) { char *rp, *endp, *word; ssize_t n = __getdelim (&line, &line_len, '\n', fp); if (n < 0) /* An error occurred. */ break; rp = line; /* Terminate the line (excluding comments or newline) by an NUL byte to simplify the following code. */ endp = strchr (rp, '#'); if (endp != NULL) *endp = '\0'; else if (rp[n - 1] == '\n') rp[n - 1] = '\0'; while (__isspace_l (*rp, _nl_C_locobj_ptr)) ++rp; /* If this is an empty line go on with the next one. */ if (rp == endp) continue; word = rp; while (*rp != '\0' && !__isspace_l (*rp, _nl_C_locobj_ptr)) ++rp; if (rp - word == sizeof ("alias") - 1 && memcmp (word, "alias", sizeof ("alias") - 1) == 0) add_alias (rp, *modules); else if (rp - word == sizeof ("module") - 1 && memcmp (word, "module", sizeof ("module") - 1) == 0) add_module (rp, directory, dir_len, modules, nmodules, modcounter++); /* else */ /* Otherwise ignore the line. */ } free (line); fclose (fp); } /* Determine the directories we are looking for data in. */ void internal_function __gconv_get_path (void) { struct path_elem *result; __libc_lock_define_initialized (static, lock); __libc_lock_lock (lock); /* Make sure there wasn't a second thread doing it already. */ result = (struct path_elem *) __gconv_path_elem; if (result == NULL) { /* Determine the complete path first. */ char *gconv_path; size_t gconv_path_len; char *elem; char *oldp; char *cp; int nelems; char *cwd; size_t cwdlen; if (__gconv_path_envvar == NULL) { /* No user-defined path. Make a modifiable copy of the default path. */ gconv_path = strdupa (default_gconv_path); gconv_path_len = sizeof (default_gconv_path); cwd = NULL; cwdlen = 0; } else { /* Append the default path to the user-defined path. */ size_t user_len = strlen (__gconv_path_envvar); gconv_path_len = user_len + 1 + sizeof (default_gconv_path); gconv_path = alloca (gconv_path_len); __mempcpy (__mempcpy (__mempcpy (gconv_path, __gconv_path_envvar, user_len), ":", 1), default_gconv_path, sizeof (default_gconv_path)); cwd = __getcwd (NULL, 0); cwdlen = __glibc_unlikely (cwd == NULL) ? 0 : strlen (cwd); } assert (default_gconv_path[0] == '/'); /* In a first pass we calculate the number of elements. */ oldp = NULL; cp = strchr (gconv_path, ':'); nelems = 1; while (cp != NULL) { if (cp != oldp + 1) ++nelems; oldp = cp; cp = strchr (cp + 1, ':'); } /* Allocate the memory for the result. */ result = (struct path_elem *) malloc ((nelems + 1) * sizeof (struct path_elem) + gconv_path_len + nelems + (nelems - 1) * (cwdlen + 1)); if (result != NULL) { char *strspace = (char *) &result[nelems + 1]; int n = 0; /* Separate the individual parts. */ __gconv_max_path_elem_len = 0; elem = __strtok_r (gconv_path, ":", &gconv_path); assert (elem != NULL); do { result[n].name = strspace; if (elem[0] != '/') { assert (cwd != NULL); strspace = __mempcpy (strspace, cwd, cwdlen); *strspace++ = '/'; } strspace = __stpcpy (strspace, elem); if (strspace[-1] != '/') *strspace++ = '/'; result[n].len = strspace - result[n].name; if (result[n].len > __gconv_max_path_elem_len) __gconv_max_path_elem_len = result[n].len; *strspace++ = '\0'; ++n; } while ((elem = __strtok_r (NULL, ":", &gconv_path)) != NULL); result[n].name = NULL; result[n].len = 0; } __gconv_path_elem = result ?: (struct path_elem *) &empty_path_elem; free (cwd); } __libc_lock_unlock (lock); } /* Read all configuration files found in the user-specified and the default path. */ void attribute_hidden __gconv_read_conf (void) { void *modules = NULL; size_t nmodules = 0; int save_errno = errno; size_t cnt; /* First see whether we should use the cache. */ if (__gconv_load_cache () == 0) { /* Yes, we are done. */ __set_errno (save_errno); return; } #ifndef STATIC_GCONV /* Find out where we have to look. */ if (__gconv_path_elem == NULL) __gconv_get_path (); for (cnt = 0; __gconv_path_elem[cnt].name != NULL; ++cnt) { const char *elem = __gconv_path_elem[cnt].name; size_t elem_len = __gconv_path_elem[cnt].len; char *filename; /* No slash needs to be inserted between elem and gconv_conf_filename; elem already ends in a slash. */ filename = alloca (elem_len + sizeof (gconv_conf_filename)); __mempcpy (__mempcpy (filename, elem, elem_len), gconv_conf_filename, sizeof (gconv_conf_filename)); /* Read the next configuration file. */ read_conf_file (filename, elem, elem_len, &modules, &nmodules); } #endif /* Add the internal modules. */ for (cnt = 0; cnt < sizeof (builtin_modules) / sizeof (builtin_modules[0]); ++cnt) { struct gconv_alias fake_alias; fake_alias.fromname = (char *) builtin_modules[cnt].from_string; if (__tfind (&fake_alias, &__gconv_alias_db, __gconv_alias_compare) != NULL) /* It'll conflict so don't add it. */ continue; insert_module (&builtin_modules[cnt], 0); } /* Add aliases for builtin conversions. */ const char *cp = builtin_aliases; do { const char *from = cp; const char *to = __rawmemchr (from, '\0') + 1; cp = __rawmemchr (to, '\0') + 1; add_alias2 (from, to, cp, modules); } while (*cp != '\0'); /* Restore the error number. */ __set_errno (save_errno); } /* Free all resources if necessary. */ libc_freeres_fn (free_mem) { if (__gconv_path_elem != NULL && __gconv_path_elem != &empty_path_elem) free ((void *) __gconv_path_elem); }