summaryrefslogtreecommitdiffstats
path: root/lib/canonicalize-lgpl.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--lib/canonicalize-lgpl.c472
1 files changed, 472 insertions, 0 deletions
diff --git a/lib/canonicalize-lgpl.c b/lib/canonicalize-lgpl.c
new file mode 100644
index 0000000..a7fa7fe
--- /dev/null
+++ b/lib/canonicalize-lgpl.c
@@ -0,0 +1,472 @@
+/* Return the canonical absolute name of a given file.
+ Copyright (C) 1996-2022 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
+ <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)
+
+# include <libc-config.h>
+#endif
+
+/* Specification. */
+#include <stdlib.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <eloop-threshold.h>
+#include <filename.h>
+#include <idx.h>
+#include <intprops.h>
+#include <scratch_buffer.h>
+
+#ifdef _LIBC
+# include <shlib-compat.h>
+# define GCC_LINT 1
+# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
+#else
+# define __canonicalize_file_name canonicalize_file_name
+# define __realpath realpath
+# include "pathmax.h"
+# define __faccessat faccessat
+# if defined _WIN32 && !defined __CYGWIN__
+# define __getcwd _getcwd
+# elif 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 __mempcpy mempcpy
+# define __pathconf pathconf
+# define __rawmemchr rawmemchr
+# define __readlink readlink
+# if IN_RELOCWRAPPER
+ /* When building the relocatable program wrapper, use the system's memmove
+ function, not the gnulib override, otherwise we would get a link error.
+ */
+# undef memmove
+# endif
+#endif
+
+/* Suppress bogus GCC -Wmaybe-uninitialized warnings. */
+#if defined GCC_LINT || defined lint
+# define IF_LINT(Code) Code
+#else
+# define IF_LINT(Code) /* empty */
+#endif
+
+#ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT
+# define DOUBLE_SLASH_IS_DISTINCT_ROOT false
+#endif
+
+#if defined _LIBC || !FUNC_REALPATH_WORKS
+
+/* Return true if FILE's existence can be shown, false (setting errno)
+ otherwise. Follow symbolic links. */
+static bool
+file_accessible (char const *file)
+{
+# if defined _LIBC || HAVE_FACCESSAT
+ return __faccessat (AT_FDCWD, file, F_OK, AT_EACCESS) == 0;
+# else
+ struct stat st;
+ return stat (file, &st) == 0 || errno == EOVERFLOW;
+# endif
+}
+
+/* True if concatenating END as a suffix to a file name means that the
+ code needs to check that the file name is that of a searchable
+ directory, since the canonicalize_filename_mode_stk code won't
+ check this later anyway when it checks an ordinary file name
+ component within END. END must either be empty, or start with a
+ slash. */
+
+static bool _GL_ATTRIBUTE_PURE
+suffix_requires_dir_check (char const *end)
+{
+ /* If END does not start with a slash, the suffix is OK. */
+ while (ISSLASH (*end))
+ {
+ /* Two or more slashes act like a single slash. */
+ do
+ end++;
+ while (ISSLASH (*end));
+
+ switch (*end++)
+ {
+ default: return false; /* An ordinary file name component is OK. */
+ case '\0': return true; /* Trailing "/" is trouble. */
+ case '.': break; /* Possibly "." or "..". */
+ }
+ /* Trailing "/.", or "/.." even if not trailing, is trouble. */
+ if (!*end || (*end == '.' && (!end[1] || ISSLASH (end[1]))))
+ return true;
+ }
+
+ return false;
+}
+
+/* Append this to a file name to test whether it is a searchable directory.
+ On POSIX platforms "/" suffices, but "/./" is sometimes needed on
+ macOS 10.13 <https://bugs.gnu.org/30350>, and should also work on
+ platforms like AIX 7.2 that need at least "/.". */
+
+# if defined _LIBC || defined LSTAT_FOLLOWS_SLASHED_SYMLINK
+static char const dir_suffix[] = "/";
+# else
+static char const dir_suffix[] = "/./";
+# endif
+
+/* Return true if DIR is a searchable dir, false (setting errno) otherwise.
+ DIREND points to the NUL byte at the end of the DIR string.
+ Store garbage into DIREND[0 .. strlen (dir_suffix)]. */
+
+static bool
+dir_check (char *dir, char *dirend)
+{
+ strcpy (dirend, dir_suffix);
+ return file_accessible (dir);
+}
+
+static idx_t
+get_path_max (void)
+{
+# ifdef PATH_MAX
+ long int path_max = PATH_MAX;
+# else
+ /* The caller invoked realpath with a null RESOLVED, even though
+ PATH_MAX is not defined as a constant. The glibc manual says
+ programs should not do this, and POSIX says the behavior is undefined.
+ Historically, glibc here used the result of pathconf, or 1024 if that
+ failed; stay consistent with this (dubious) historical practice. */
+ int err = errno;
+ long int path_max = __pathconf ("/", _PC_PATH_MAX);
+ __set_errno (err);
+# endif
+ return path_max < 0 ? 1024 : path_max <= IDX_MAX ? path_max : IDX_MAX;
+}
+
+/* Act like __realpath (see below), with an additional argument
+ rname_buf that can be used as temporary storage.
+
+ If GCC_LINT is defined, do not inline this function with GCC 10.1
+ and later, to avoid creating a pointer to the stack that GCC
+ -Wreturn-local-addr incorrectly complains about. See:
+ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644
+ Although the noinline attribute can hurt performance a bit, no better way
+ to pacify GCC is known; even an explicit #pragma does not pacify GCC.
+ When the GCC bug is fixed this workaround should be limited to the
+ broken GCC versions. */
+# if __GNUC_PREREQ (10, 1)
+# if defined GCC_LINT || defined lint
+__attribute__ ((__noinline__))
+# elif __OPTIMIZE__ && !__NO_INLINE__
+# define GCC_BOGUS_WRETURN_LOCAL_ADDR
+# endif
+# endif
+static char *
+realpath_stk (const char *name, char *resolved,
+ struct scratch_buffer *rname_buf)
+{
+ char *dest;
+ char const *start;
+ char const *end;
+ 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;
+ }
+
+ struct scratch_buffer extra_buffer, link_buffer;
+ scratch_buffer_init (&extra_buffer);
+ scratch_buffer_init (&link_buffer);
+ scratch_buffer_init (rname_buf);
+ char *rname_on_stack = rname_buf->data;
+ char *rname = rname_on_stack;
+ bool end_in_extra_buffer = false;
+ bool failed = true;
+
+ /* This is always zero for Posix hosts, but can be 2 for MS-Windows
+ and MS-DOS X:/foo/bar file names. */
+ idx_t prefix_len = FILE_SYSTEM_PREFIX_LEN (name);
+
+ if (!IS_ABSOLUTE_FILE_NAME (name))
+ {
+ while (!__getcwd (rname, rname_buf->length))
+ {
+ if (errno != ERANGE)
+ {
+ dest = rname;
+ goto error;
+ }
+ if (!scratch_buffer_grow (rname_buf))
+ goto error_nomem;
+ rname = rname_buf->data;
+ }
+ dest = __rawmemchr (rname, '\0');
+ start = name;
+ prefix_len = FILE_SYSTEM_PREFIX_LEN (rname);
+ }
+ else
+ {
+ dest = __mempcpy (rname, name, prefix_len);
+ *dest++ = '/';
+ if (DOUBLE_SLASH_IS_DISTINCT_ROOT)
+ {
+ if (prefix_len == 0 /* implies ISSLASH (name[0]) */
+ && ISSLASH (name[1]) && !ISSLASH (name[2]))
+ *dest++ = '/';
+ *dest = '\0';
+ }
+ start = name + prefix_len;
+ }
+
+ for ( ; *start; start = end)
+ {
+ /* Skip sequence of multiple file name separators. */
+ while (ISSLASH (*start))
+ ++start;
+
+ /* Find end of component. */
+ for (end = start; *end && !ISSLASH (*end); ++end)
+ /* Nothing. */;
+
+ /* Length of this file name component; it can be zero if a file
+ name ends in '/'. */
+ idx_t startlen = end - start;
+
+ if (startlen == 0)
+ break;
+ else if (startlen == 1 && start[0] == '.')
+ /* nothing */;
+ else if (startlen == 2 && start[0] == '.' && start[1] == '.')
+ {
+ /* Back up to previous component, ignore if at root already. */
+ if (dest > rname + prefix_len + 1)
+ for (--dest; dest > rname && !ISSLASH (dest[-1]); --dest)
+ continue;
+ if (DOUBLE_SLASH_IS_DISTINCT_ROOT
+ && dest == rname + 1 && !prefix_len
+ && ISSLASH (*dest) && !ISSLASH (dest[1]))
+ dest++;
+ }
+ else
+ {
+ if (!ISSLASH (dest[-1]))
+ *dest++ = '/';
+
+ while (rname + rname_buf->length - dest
+ < startlen + sizeof dir_suffix)
+ {
+ idx_t dest_offset = dest - rname;
+ if (!scratch_buffer_grow_preserve (rname_buf))
+ goto error_nomem;
+ rname = rname_buf->data;
+ dest = rname + dest_offset;
+ }
+
+ dest = __mempcpy (dest, start, startlen);
+ *dest = '\0';
+
+ char *buf;
+ ssize_t n;
+ while (true)
+ {
+ buf = link_buffer.data;
+ idx_t bufsize = link_buffer.length;
+ n = __readlink (rname, buf, bufsize - 1);
+ if (n < bufsize - 1)
+ break;
+ if (!scratch_buffer_grow (&link_buffer))
+ goto error_nomem;
+ }
+ if (0 <= n)
+ {
+ if (++num_links > __eloop_threshold ())
+ {
+ __set_errno (ELOOP);
+ goto error;
+ }
+
+ buf[n] = '\0';
+
+ char *extra_buf = extra_buffer.data;
+ idx_t end_idx IF_LINT (= 0);
+ if (end_in_extra_buffer)
+ end_idx = end - extra_buf;
+ size_t len = strlen (end);
+ if (INT_ADD_OVERFLOW (len, n))
+ {
+ __set_errno (ENOMEM);
+ goto error_nomem;
+ }
+ while (extra_buffer.length <= len + n)
+ {
+ if (!scratch_buffer_grow_preserve (&extra_buffer))
+ goto error_nomem;
+ extra_buf = extra_buffer.data;
+ }
+ if (end_in_extra_buffer)
+ end = extra_buf + end_idx;
+
+ /* Careful here, end may be a pointer into extra_buf... */
+ memmove (&extra_buf[n], end, len + 1);
+ name = end = memcpy (extra_buf, buf, n);
+ end_in_extra_buffer = true;
+
+ if (IS_ABSOLUTE_FILE_NAME (buf))
+ {
+ idx_t pfxlen = FILE_SYSTEM_PREFIX_LEN (buf);
+
+ dest = __mempcpy (rname, buf, 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 > rname + prefix_len + 1)
+ for (--dest; dest > rname && !ISSLASH (dest[-1]); --dest)
+ continue;
+ if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1
+ && ISSLASH (*dest) && !ISSLASH (dest[1]) && !prefix_len)
+ dest++;
+ }
+ }
+ else if (! (suffix_requires_dir_check (end)
+ ? dir_check (rname, dest)
+ : errno == EINVAL))
+ goto error;
+ }
+ }
+ if (dest > rname + prefix_len + 1 && ISSLASH (dest[-1]))
+ --dest;
+ if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1 && !prefix_len
+ && ISSLASH (*dest) && !ISSLASH (dest[1]))
+ dest++;
+ failed = false;
+
+error:
+ *dest++ = '\0';
+ if (resolved != NULL && dest - rname <= get_path_max ())
+ rname = strcpy (resolved, rname);
+
+error_nomem:
+ scratch_buffer_free (&extra_buffer);
+ scratch_buffer_free (&link_buffer);
+
+ if (failed || rname == resolved)
+ {
+ scratch_buffer_free (rname_buf);
+ return failed ? NULL : resolved;
+ }
+
+ return scratch_buffer_dupfree (rname_buf, dest - rname);
+}
+
+/* Return the canonical absolute name of file NAME. A canonical name
+ does not contain any ".", ".." components nor any repeated file name
+ separators ('/') or symlinks. All file name 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 name of the first component
+ that cannot be resolved. If the name can be resolved, RESOLVED
+ holds the same value as the value returned. */
+
+char *
+__realpath (const char *name, char *resolved)
+{
+ #ifdef GCC_BOGUS_WRETURN_LOCAL_ADDR
+ #warning "GCC might issue a bogus -Wreturn-local-addr warning here."
+ #warning "See <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93644>."
+ #endif
+ struct scratch_buffer rname_buffer;
+ return realpath_stk (name, resolved, &rname_buffer);
+}
+libc_hidden_def (__realpath)
+versioned_symbol (libc, __realpath, realpath, GLIBC_2_3);
+
+#endif /* defined _LIBC || !FUNC_REALPATH_WORKS */
+
+
+#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)