diff options
Diffstat (limited to 'gl/lib/canonicalize-lgpl.c')
| -rw-r--r-- | gl/lib/canonicalize-lgpl.c | 428 |
1 files changed, 428 insertions, 0 deletions
diff --git a/gl/lib/canonicalize-lgpl.c b/gl/lib/canonicalize-lgpl.c new file mode 100644 index 0000000..4d1be6d --- /dev/null +++ b/gl/lib/canonicalize-lgpl.c @@ -0,0 +1,428 @@ +/* Return the canonical absolute name of a given file. + Copyright (C) 1996-2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. */ + +#ifndef _LIBC +/* Don't use __attribute__ __nonnull__ in this compilation unit. Otherwise gcc + optimizes away the name == NULL test below. */ +# define _GL_ARG_NONNULL(params) + +# define _GL_USE_STDLIB_ALLOC 1 +# include <config.h> +#endif + +#if !HAVE_CANONICALIZE_FILE_NAME || !FUNC_REALPATH_WORKS || defined _LIBC + +/* Specification. */ +#include <stdlib.h> + +#include <alloca.h> +#include <string.h> +#include <unistd.h> +#include <limits.h> +#if HAVE_SYS_PARAM_H || defined _LIBC +# include <sys/param.h> +#endif +#include <sys/stat.h> +#include <errno.h> +#include <stddef.h> + +#ifdef _LIBC +# include <shlib-compat.h> +#else +# define SHLIB_COMPAT(lib, introduced, obsoleted) 0 +# define versioned_symbol(lib, local, symbol, version) extern int dummy +# define compat_symbol(lib, local, symbol, version) +# define weak_alias(local, symbol) +# define __canonicalize_file_name canonicalize_file_name +# define __realpath realpath +# include "pathmax.h" +# include "malloca.h" +# include "dosname.h" +# if HAVE_GETCWD +# if IN_RELOCWRAPPER + /* When building the relocatable program wrapper, use the system's getcwd + function, not the gnulib override, otherwise we would get a link error. + */ +# undef getcwd +# endif +# if defined VMS && !defined getcwd + /* We want the directory in Unix syntax, not in VMS syntax. + The gnulib override of 'getcwd' takes 2 arguments; the original VMS + 'getcwd' takes 3 arguments. */ +# define __getcwd(buf, max) getcwd (buf, max, 0) +# else +# define __getcwd getcwd +# endif +# else +# define __getcwd(buf, max) getwd (buf) +# endif +# define __readlink readlink +# define __set_errno(e) errno = (e) +# ifndef MAXSYMLINKS +# ifdef SYMLOOP_MAX +# define MAXSYMLINKS SYMLOOP_MAX +# else +# define MAXSYMLINKS 20 +# endif +# endif +#endif + +#ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT +# define DOUBLE_SLASH_IS_DISTINCT_ROOT 0 +#endif + +/* Define this independently so that stdint.h is not a prerequisite. */ +#ifndef SIZE_MAX +# define SIZE_MAX ((size_t) -1) +#endif + +#if !FUNC_REALPATH_WORKS || defined _LIBC + +static void +alloc_failed (void) +{ +#if defined _WIN32 && ! defined __CYGWIN__ + /* Avoid errno problem without using the malloc or realloc modules; see: + https://lists.gnu.org/r/bug-gnulib/2016-08/msg00025.html */ + errno = ENOMEM; +#endif +} + +/* 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; + size_t prefix_len; + + 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 = 8192; +#endif + + if (resolved == NULL) + { + rpath = malloc (path_max); + if (rpath == NULL) + { + alloc_failed (); + return NULL; + } + } + else + rpath = resolved; + rpath_limit = rpath + path_max; + + /* This is always zero for Posix hosts, but can be 2 for MS-Windows + and MS-DOS X:/foo/bar file names. */ + prefix_len = FILE_SYSTEM_PREFIX_LEN (name); + + if (!IS_ABSOLUTE_FILE_NAME (name)) + { + if (!__getcwd (rpath, path_max)) + { + rpath[0] = '\0'; + goto error; + } + dest = strchr (rpath, '\0'); + start = name; + prefix_len = FILE_SYSTEM_PREFIX_LEN (rpath); + } + else + { + dest = rpath; + if (prefix_len) + { + memcpy (rpath, name, prefix_len); + dest += prefix_len; + } + *dest++ = '/'; + if (DOUBLE_SLASH_IS_DISTINCT_ROOT) + { + if (ISSLASH (name[1]) && !ISSLASH (name[2]) && !prefix_len) + *dest++ = '/'; + *dest = '\0'; + } + start = name + prefix_len; + } + + for (end = start; *start; start = end) + { +#ifdef _LIBC + struct stat64 st; +#else + struct stat st; +#endif + + /* Skip sequence of multiple path-separators. */ + while (ISSLASH (*start)) + ++start; + + /* Find end of path component. */ + for (end = start; *end && !ISSLASH (*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 + prefix_len + 1) + for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest) + continue; + if (DOUBLE_SLASH_IS_DISTINCT_ROOT + && dest == rpath + 1 && !prefix_len + && ISSLASH (*dest) && !ISSLASH (dest[1])) + dest++; + } + else + { + size_t new_size; + + if (!ISSLASH (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 + prefix_len + 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) + { + alloc_failed (); + goto error; + } + rpath = new_rpath; + rpath_limit = rpath + new_size; + + dest = rpath + dest_offset; + } + +#ifdef _LIBC + dest = __mempcpy (dest, start, end - start); +#else + memcpy (dest, start, end - start); + dest += end - start; +#endif + *dest = '\0'; + + /* FIXME: if lstat fails with errno == EOVERFLOW, + the entry exists. */ +#ifdef _LIBC + if (__lxstat64 (_STAT_VER, rpath, &st) < 0) +#else + if (lstat (rpath, &st) < 0) +#endif + goto error; + + if (S_ISLNK (st.st_mode)) + { + char *buf; + size_t len; + ssize_t n; + + if (++num_links > MAXSYMLINKS) + { + __set_errno (ELOOP); + goto error; + } + + buf = malloca (path_max); + if (!buf) + { + __set_errno (ENOMEM); + goto error; + } + + n = __readlink (rpath, buf, path_max - 1); + if (n < 0) + { + int saved_errno = errno; + freea (buf); + __set_errno (saved_errno); + goto error; + } + buf[n] = '\0'; + + if (!extra_buf) + { + extra_buf = malloca (path_max); + if (!extra_buf) + { + freea (buf); + __set_errno (ENOMEM); + goto error; + } + } + + len = strlen (end); + /* Check that n + len + 1 doesn't overflow and is <= path_max. */ + if (n >= SIZE_MAX - len || n + len >= path_max) + { + freea (buf); + __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 (IS_ABSOLUTE_FILE_NAME (buf)) + { + size_t pfxlen = FILE_SYSTEM_PREFIX_LEN (buf); + + if (pfxlen) + memcpy (rpath, buf, pfxlen); + dest = rpath + pfxlen; + *dest++ = '/'; /* It's an absolute symlink */ + if (DOUBLE_SLASH_IS_DISTINCT_ROOT) + { + if (ISSLASH (buf[1]) && !ISSLASH (buf[2]) && !pfxlen) + *dest++ = '/'; + *dest = '\0'; + } + /* Install the new prefix to be in effect hereafter. */ + prefix_len = pfxlen; + } + else + { + /* Back up to previous component, ignore if at root + already: */ + if (dest > rpath + prefix_len + 1) + for (--dest; dest > rpath && !ISSLASH (dest[-1]); --dest) + continue; + if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 + && ISSLASH (*dest) && !ISSLASH (dest[1]) && !prefix_len) + dest++; + } + } + else if (!S_ISDIR (st.st_mode) && *end != '\0') + { + __set_errno (ENOTDIR); + goto error; + } + } + } + if (dest > rpath + prefix_len + 1 && ISSLASH (dest[-1])) + --dest; + if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rpath + 1 && !prefix_len + && ISSLASH (*dest) && !ISSLASH (dest[1])) + dest++; + *dest = '\0'; + + if (extra_buf) + freea (extra_buf); + + return rpath; + +error: + { + int saved_errno = errno; + if (extra_buf) + freea (extra_buf); + if (resolved == NULL) + free (rpath); + __set_errno (saved_errno); + } + return NULL; +} +versioned_symbol (libc, __realpath, realpath, GLIBC_2_3); +#endif /* !FUNC_REALPATH_WORKS || defined _LIBC */ + + +#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) + +#else + +/* This declaration is solely to ensure that after preprocessing + this file is never empty. */ +typedef int dummy; + +#endif |