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Diffstat (limited to 'REORG.TODO/stdlib/canonicalize.c')
| -rw-r--r-- | REORG.TODO/stdlib/canonicalize.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/REORG.TODO/stdlib/canonicalize.c b/REORG.TODO/stdlib/canonicalize.c new file mode 100644 index 0000000000..c3d892c862 --- /dev/null +++ b/REORG.TODO/stdlib/canonicalize.c @@ -0,0 +1,246 @@ +/* Return the canonical absolute name of a given file. + Copyright (C) 1996-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + 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 + <http://www.gnu.org/licenses/>. */ + +#include <assert.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <limits.h> +#include <sys/stat.h> +#include <errno.h> +#include <stddef.h> + +#include <eloop-threshold.h> +#include <shlib-compat.h> + +/* Return the canonical absolute name of file NAME. A canonical name + does not contain any `.', `..' components nor any repeated path + separators ('/') or symlinks. All path components must exist. If + RESOLVED is null, the result is malloc'd; otherwise, if the + canonical name is PATH_MAX chars or more, returns null with `errno' + set to ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars, + returns the name in RESOLVED. If the name cannot be resolved and + RESOLVED is non-NULL, it contains the path of the first component + that cannot be resolved. If the path can be resolved, RESOLVED + holds the same value as the value returned. */ + +char * +__realpath (const char *name, char *resolved) +{ + char *rpath, *dest, *extra_buf = NULL; + const char *start, *end, *rpath_limit; + long int path_max; + int num_links = 0; + + if (name == NULL) + { + /* As per Single Unix Specification V2 we must return an error if + either parameter is a null pointer. We extend this to allow + the RESOLVED parameter to be NULL in case the we are expected to + allocate the room for the return value. */ + __set_errno (EINVAL); + return NULL; + } + + if (name[0] == '\0') + { + /* As per Single Unix Specification V2 we must return an error if + the name argument points to an empty string. */ + __set_errno (ENOENT); + return NULL; + } + +#ifdef PATH_MAX + path_max = PATH_MAX; +#else + path_max = pathconf (name, _PC_PATH_MAX); + if (path_max <= 0) + path_max = 1024; +#endif + + if (resolved == NULL) + { + rpath = malloc (path_max); + if (rpath == NULL) + return NULL; + } + else + rpath = resolved; + rpath_limit = rpath + path_max; + + if (name[0] != '/') + { + if (!__getcwd (rpath, path_max)) + { + rpath[0] = '\0'; + goto error; + } + dest = __rawmemchr (rpath, '\0'); + } + else + { + rpath[0] = '/'; + dest = rpath + 1; + } + + for (start = end = name; *start; start = end) + { + struct stat64 st; + int n; + + /* Skip sequence of multiple path-separators. */ + while (*start == '/') + ++start; + + /* Find end of path component. */ + for (end = start; *end && *end != '/'; ++end) + /* Nothing. */; + + if (end - start == 0) + break; + else if (end - start == 1 && start[0] == '.') + /* nothing */; + else if (end - start == 2 && start[0] == '.' && start[1] == '.') + { + /* Back up to previous component, ignore if at root already. */ + if (dest > rpath + 1) + while ((--dest)[-1] != '/'); + } + else + { + size_t new_size; + + if (dest[-1] != '/') + *dest++ = '/'; + + if (dest + (end - start) >= rpath_limit) + { + ptrdiff_t dest_offset = dest - rpath; + char *new_rpath; + + if (resolved) + { + __set_errno (ENAMETOOLONG); + if (dest > rpath + 1) + dest--; + *dest = '\0'; + goto error; + } + new_size = rpath_limit - rpath; + if (end - start + 1 > path_max) + new_size += end - start + 1; + else + new_size += path_max; + new_rpath = (char *) realloc (rpath, new_size); + if (new_rpath == NULL) + goto error; + rpath = new_rpath; + rpath_limit = rpath + new_size; + + dest = rpath + dest_offset; + } + + dest = __mempcpy (dest, start, end - start); + *dest = '\0'; + + if (__lxstat64 (_STAT_VER, rpath, &st) < 0) + goto error; + + if (S_ISLNK (st.st_mode)) + { + char *buf = __alloca (path_max); + size_t len; + + if (++num_links > __eloop_threshold ()) + { + __set_errno (ELOOP); + goto error; + } + + n = __readlink (rpath, buf, path_max - 1); + if (n < 0) + goto error; + buf[n] = '\0'; + + if (!extra_buf) + extra_buf = __alloca (path_max); + + len = strlen (end); + if ((long int) (n + len) >= path_max) + { + __set_errno (ENAMETOOLONG); + goto error; + } + + /* Careful here, end may be a pointer into extra_buf... */ + memmove (&extra_buf[n], end, len + 1); + name = end = memcpy (extra_buf, buf, n); + + if (buf[0] == '/') + dest = rpath + 1; /* It's an absolute symlink */ + else + /* Back up to previous component, ignore if at root already: */ + if (dest > rpath + 1) + while ((--dest)[-1] != '/'); + } + else if (!S_ISDIR (st.st_mode) && *end != '\0') + { + __set_errno (ENOTDIR); + goto error; + } + } + } + if (dest > rpath + 1 && dest[-1] == '/') + --dest; + *dest = '\0'; + + assert (resolved == NULL || resolved == rpath); + return rpath; + +error: + assert (resolved == NULL || resolved == rpath); + if (resolved == NULL) + free (rpath); + return NULL; +} +versioned_symbol (libc, __realpath, realpath, GLIBC_2_3); + + +#if SHLIB_COMPAT(libc, GLIBC_2_0, GLIBC_2_3) +char * +attribute_compat_text_section +__old_realpath (const char *name, char *resolved) +{ + if (resolved == NULL) + { + __set_errno (EINVAL); + return NULL; + } + + return __realpath (name, resolved); +} +compat_symbol (libc, __old_realpath, realpath, GLIBC_2_0); +#endif + + +char * +__canonicalize_file_name (const char *name) +{ + return __realpath (name, NULL); +} +weak_alias (__canonicalize_file_name, canonicalize_file_name) |