diff options
| -rw-r--r-- | lib/canonicalize.c | 332 | ||||
| -rw-r--r-- | lib/canonicalize.h | 41 | ||||
| -rw-r--r-- | m4/canonicalize.m4 | 27 | ||||
| -rw-r--r-- | modules/canonicalize | 27 |
4 files changed, 427 insertions, 0 deletions
diff --git a/lib/canonicalize.c b/lib/canonicalize.c new file mode 100644 index 0000000000..6d1bfbc6f8 --- /dev/null +++ b/lib/canonicalize.c @@ -0,0 +1,332 @@ +/* Return the canonical absolute name of a given file. + Copyright (C) 1996-2004 Free Software Foundation, Inc. + + 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 2, 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; see the file COPYING. + If not, write to the Free Software Foundation, + 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#ifdef STDC_HEADERS +# include <stdlib.h> +#else +void free (); +#endif + +#if defined STDC_HEADERS || defined HAVE_STRING_H +# include <string.h> +#else +# include <strings.h> +#endif + +#if HAVE_SYS_PARAM_H +# include <sys/param.h> +#endif + +#include <sys/stat.h> + +#if HAVE_UNISTD_H +# include <unistd.h> +#endif + +#include <errno.h> + +#include "cycle-check.h" +#include "path-concat.h" +#include "stat-macros.h" +#include "xalloc.h" +#include "xgetcwd.h" + +#ifndef __set_errno +# define __set_errno(Val) errno = (Val) +#endif + +/* If __PTRDIFF_TYPE__ is + defined, as with GNU C, use that; that way we don't pollute the + namespace with <stddef.h>'s symbols. Otherwise, if <stddef.h> is + available, include it and use ptrdiff_t. In traditional C, long is + the best that we can do. */ + +#ifdef __PTRDIFF_TYPE__ +# define PTR_INT_TYPE __PTRDIFF_TYPE__ +#else +# ifdef HAVE_STDDEF_H +# include <stddef.h> +# define PTR_INT_TYPE ptrdiff_t +# else +# define PTR_INT_TYPE long +# endif +#endif + +#include "canonicalize.h" +#include "pathmax.h" +#include "stat-macros.h" +#include "xreadlink.h" + +#if !HAVE_CANONICALIZE_FILE_NAME +/* 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. + The result is malloc'd. */ + +char * +canonicalize_file_name (const char *name) +{ +# if HAVE_RESOLVEPATH + + char *resolved, *extra_buf = NULL; + size_t resolved_size; + ssize_t resolved_len; + + if (name == NULL) + { + __set_errno (EINVAL); + return NULL; + } + + if (name[0] == '\0') + { + __set_errno (ENOENT); + return NULL; + } + + /* All known hosts with resolvepath (e.g. Solaris 7) don't turn + relative names into absolute ones, so prepend the working + directory if the path is not absolute. */ + if (name[0] != '/') + { + char *wd; + + if (!(wd = xgetcwd ())) + return NULL; + + extra_buf = path_concat (wd, name, NULL); + name = extra_buf; + free (wd); + } + + resolved_size = strlen (name); + while (1) + { + resolved_size = 2 * resolved_size + 1; + resolved = xmalloc (resolved_size); + resolved_len = resolvepath (name, resolved, resolved_size); + if (resolved_len < 0) + { + free (resolved); + free (extra_buf); + return NULL; + } + if (resolved_len < resolved_size) + break; + free (resolved); + } + + free (extra_buf); + + /* NUL-terminate the resulting name. */ + resolved[resolved_len] = '\0'; + + return resolved; + +# else + + return canonicalize_filename_mode (name, CAN_EXISTING); + +# endif /* !HAVE_RESOLVEPATH */ +} +#endif /* !HAVE_CANONICALIZE_FILE_NAME */ + +/* Return the canonical absolute name of file NAME. A canonical name + does not contain any `.', `..' components nor any repeated path + separators ('/') or symlinks. Whether path components must exist + or not depends on canonicalize mode. The result is malloc'd. */ + +char * +canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode) +{ + char *rpath, *dest, *extra_buf = NULL; + const char *start, *end, *rpath_limit; + size_t extra_len = 0; + struct cycle_check_state cycle_state; + + if (name == NULL) + { + __set_errno (EINVAL); + return NULL; + } + + if (name[0] == '\0') + { + __set_errno (ENOENT); + return NULL; + } + + if (name[0] != '/') + { + rpath = xgetcwd (); + if (!rpath) + return NULL; + dest = strchr (rpath, '\0'); + if (dest - rpath < PATH_MAX) + { + char *p = xrealloc (rpath, PATH_MAX); + dest = p + (dest - rpath); + rpath = p; + rpath_limit = rpath + PATH_MAX; + } + else + { + rpath_limit = dest; + } + } + else + { + rpath = xmalloc (PATH_MAX); + rpath_limit = rpath + PATH_MAX; + rpath[0] = '/'; + dest = rpath + 1; + } + + cycle_check_init (&cycle_state); + for (start = end = name; *start; start = end) + { + /* 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 + { + struct stat st; + + if (dest[-1] != '/') + *dest++ = '/'; + + if (dest + (end - start) >= rpath_limit) + { + PTR_INT_TYPE dest_offset = dest - rpath; + size_t new_size = rpath_limit - rpath; + + if (end - start + 1 > PATH_MAX) + new_size += end - start + 1; + else + new_size += PATH_MAX; + rpath = xrealloc (rpath, new_size); + rpath_limit = rpath + new_size; + + dest = rpath + dest_offset; + } + + dest = memcpy (dest, start, end - start); + dest += end - start; + *dest = '\0'; + + if (lstat (rpath, &st) < 0) + { + if (can_mode == CAN_EXISTING) + goto error; + if (can_mode == CAN_ALL_BUT_LAST && *end) + goto error; + st.st_mode = 0; + } + + if (S_ISLNK (st.st_mode)) + { + char *buf; + size_t n, len; + + if (cycle_check (&cycle_state, &st)) + { + __set_errno (ELOOP); + if (can_mode == CAN_MISSING) + continue; + else + goto error; + } + + buf = xreadlink (rpath, st.st_size); + if (!buf) + { + if (can_mode == CAN_MISSING) + continue; + else + goto error; + } + + n = strlen (buf); + len = strlen (end); + + if (!extra_len) + { + extra_len = + ((n + len + 1) > PATH_MAX) ? (n + len + 1) : PATH_MAX; + extra_buf = xmalloc (extra_len); + } + else if ((n + len + 1) > extra_len) + { + extra_len = n + len + 1; + extra_buf = xrealloc (extra_buf, extra_len); + } + + /* 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] != '/'); + + free (buf); + } + else + { + if (!S_ISDIR (st.st_mode) && *end && (can_mode != CAN_MISSING)) + { + errno = ENOTDIR; + goto error; + } + } + } + } + if (dest > rpath + 1 && dest[-1] == '/') + --dest; + *dest = '\0'; + + free (extra_buf); + return rpath; + +error: + free (extra_buf); + free (rpath); + return NULL; +} diff --git a/lib/canonicalize.h b/lib/canonicalize.h new file mode 100644 index 0000000000..2f73de0eac --- /dev/null +++ b/lib/canonicalize.h @@ -0,0 +1,41 @@ +/* Return the canonical absolute name of a given file. + Copyright (C) 1996-2004 Free Software Foundation, Inc. + + 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 2, 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; see the file COPYING. + If not, write to the Free Software Foundation, + 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#ifndef CANONICALIZE_H_ +# define CANONICALIZE_H_ + +enum canonicalize_mode_t + { + /* All path components must exist. */ + CAN_EXISTING = 0, + + /* All path components excluding last one must exist. */ + CAN_ALL_BUT_LAST = 1, + + /* No requirements on components existence. */ + CAN_MISSING = 2 + }; +typedef enum canonicalize_mode_t canonicalize_mode_t; + +char *canonicalize_filename_mode (const char *, canonicalize_mode_t); + +# if !HAVE_CANONICALIZE_FILE_NAME +char *canonicalize_file_name (const char *); +# endif + +#endif /* !CANONICALIZE_H_ */ diff --git a/m4/canonicalize.m4 b/m4/canonicalize.m4 new file mode 100644 index 0000000000..0731f4dc57 --- /dev/null +++ b/m4/canonicalize.m4 @@ -0,0 +1,27 @@ +#serial 3 + +# Copyright (C) 2003, 2004 Free Software Foundation, Inc. + +# 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 2, 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, write to the Free Software Foundation, +# Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +# Written by Jim Meyering. + +AC_DEFUN([AC_FUNC_CANONICALIZE_FILE_NAME], + [ + AC_REQUIRE([AC_HEADER_STDC]) + AC_CHECK_HEADERS(string.h sys/param.h stddef.h) + AC_CHECK_FUNCS(resolvepath canonicalize_file_name) + AC_REQUIRE([AC_HEADER_STAT]) + ]) diff --git a/modules/canonicalize b/modules/canonicalize new file mode 100644 index 0000000000..a8d14c171b --- /dev/null +++ b/modules/canonicalize @@ -0,0 +1,27 @@ +Description: +Return the canonical absolute name of a given file. + +Files: +lib/canonicalize.h +lib/canonicalize.c +lib/stat-macros.h +m4/canonicalize.m4 + +Depends-on: +cycle-check +path-concat +xalloc +xgetcwd + +configure.ac: +AC_FUNC_CANONICALIZE_FILE_NAME + +Makefile.am: +lib_SOURCES += canonicalize.h canonicalize.c + +Include: +"canonicalize.h" + +Maintainer: +Jim Meyering + |