X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fcanonicalize.c;h=6a39a022340842f8c88d65737774b3fb622e9f1d;hb=43593319b31e6b0175b8eec4433bac744959822d;hp=ba60248d94bc4e0c8be863053a643b60793692b4;hpb=267a39bafd249d7eb9c37df06dc6defcf41cb343;p=gnulib.git diff --git a/lib/canonicalize.c b/lib/canonicalize.c index ba60248d9..6a39a0223 100644 --- a/lib/canonicalize.c +++ b/lib/canonicalize.c @@ -1,10 +1,10 @@ /* Return the canonical absolute name of a given file. - Copyright (C) 1996-2005 Free Software Foundation, Inc. + Copyright (C) 1996-2013 Free Software Foundation, Inc. - This program is free software; you can redistribute it and/or modify + 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. + 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 @@ -12,320 +12,343 @@ 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, - 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + along with this program. If not, see . */ -#ifdef HAVE_CONFIG_H -# include -#endif - -#ifdef STDC_HEADERS -# include -#else -void free (); -#endif - -#if defined STDC_HEADERS || defined HAVE_STRING_H -# include -#else -# include -#endif +#include -#if HAVE_SYS_PARAM_H -# include -#endif - -#include - -#if HAVE_UNISTD_H -# include -#endif +#include "canonicalize.h" #include +#include +#include +#include +#include -#include "cycle-check.h" -#include "path-concat.h" -#include "stat-macros.h" +#include "areadlink.h" +#include "file-set.h" +#include "hash-triple.h" +#include "pathmax.h" #include "xalloc.h" #include "xgetcwd.h" +#include "dosname.h" + +#define MULTIPLE_BITS_SET(i) (((i) & ((i) - 1)) != 0) -#ifndef __set_errno -# define __set_errno(Val) errno = (Val) +/* In this file, we cannot handle file names longer than PATH_MAX. + On systems with no file name length limit, use a fallback. */ +#ifndef PATH_MAX +# define PATH_MAX 8192 #endif -/* If __PTRDIFF_TYPE__ is - defined, as with GNU C, use that; that way we don't pollute the - namespace with 's symbols. Otherwise, if is - available, include it and use ptrdiff_t. In traditional C, long is - the best that we can do. */ +#ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT +# define DOUBLE_SLASH_IS_DISTINCT_ROOT 0 +#endif -#ifdef __PTRDIFF_TYPE__ -# define PTR_INT_TYPE __PTRDIFF_TYPE__ +#if ISSLASH ('\\') +# define SLASHES "/\\" #else -# ifdef HAVE_STDDEF_H -# include -# define PTR_INT_TYPE ptrdiff_t -# else -# define PTR_INT_TYPE long -# endif +# define SLASHES "/" #endif -#include "canonicalize.h" -#include "pathmax.h" -#include "xreadlink.h" - -#if !HAVE_CANONICALIZE_FILE_NAME +#if !((HAVE_CANONICALIZE_FILE_NAME && FUNC_REALPATH_WORKS) \ + || GNULIB_CANONICALIZE_LGPL) /* 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. + does not contain any ".", ".." components nor any repeated file name + separators ('/') or symlinks. All 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); - } + return canonicalize_filename_mode (name, CAN_EXISTING); +} +#endif /* !HAVE_CANONICALIZE_FILE_NAME */ - resolved_size = strlen (name); - while (1) +/* Return true if we've already seen the triple, . + If *HT is not initialized, initialize it. */ +static bool +seen_triple (Hash_table **ht, char const *filename, struct stat const *st) +{ + if (*ht == NULL) { - 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); + size_t initial_capacity = 7; + *ht = hash_initialize (initial_capacity, + NULL, + triple_hash, + triple_compare_ino_str, + triple_free); + if (*ht == NULL) + xalloc_die (); } - free (extra_buf); - - /* NUL-terminate the resulting name. */ - resolved[resolved_len] = '\0'; + if (seen_file (*ht, filename, st)) + return true; - return resolved; - -# else - - return canonicalize_filename_mode (name, CAN_EXISTING); - -# endif /* !HAVE_RESOLVEPATH */ + record_file (*ht, filename, st); + return false; } -#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. */ +/* Return the canonical absolute name of file NAME, while treating + missing elements according to CAN_MODE. A canonical name + does not contain any ".", ".." components nor any repeated file name + separators ('/') or, depending on other CAN_MODE flags, symlinks. + Whether 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; + char *rname, *dest, *extra_buf = NULL; + char const *start; + char const *end; + char const *rname_limit; size_t extra_len = 0; - struct cycle_check_state cycle_state; + Hash_table *ht = NULL; + int saved_errno; + int can_flags = can_mode & ~CAN_MODE_MASK; + bool logical = can_flags & CAN_NOLINKS; + size_t prefix_len; + + can_mode &= CAN_MODE_MASK; + + if (MULTIPLE_BITS_SET (can_mode)) + { + errno = EINVAL; + return NULL; + } if (name == NULL) { - __set_errno (EINVAL); + errno = EINVAL; return NULL; } if (name[0] == '\0') { - __set_errno (ENOENT); + errno = ENOENT; return NULL; } - if (name[0] != '/') + /* 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)) { - 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; - } + rname = xgetcwd (); + if (!rname) + return NULL; + dest = strchr (rname, '\0'); + if (dest - rname < PATH_MAX) + { + char *p = xrealloc (rname, PATH_MAX); + dest = p + (dest - rname); + rname = p; + rname_limit = rname + PATH_MAX; + } else - { - rpath_limit = dest; - } + { + rname_limit = dest; + } + start = name; + prefix_len = FILE_SYSTEM_PREFIX_LEN (rname); } else { - rpath = xmalloc (PATH_MAX); - rpath_limit = rpath + PATH_MAX; - rpath[0] = '/'; - dest = rpath + 1; + rname = xmalloc (PATH_MAX); + rname_limit = rname + PATH_MAX; + dest = rname; + if (prefix_len) + { + memcpy (rname, 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; } - cycle_check_init (&cycle_state); - for (start = end = name; *start; start = end) + for ( ; *start; start = end) { - /* Skip sequence of multiple path-separators. */ - while (*start == '/') - ++start; + /* Skip sequence of multiple file name separators. */ + while (ISSLASH (*start)) + ++start; - /* Find end of path component. */ - for (end = start; *end && *end != '/'; ++end) - /* Nothing. */; + /* Find end of component. */ + for (end = start; *end && !ISSLASH (*end); ++end) + /* Nothing. */; if (end - start == 0) - break; + break; else if (end - start == 1 && start[0] == '.') - /* nothing */; + /* 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] != '/'); - } + { + /* 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 - { - 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; - } - } - } + { + struct stat st; + + if (!ISSLASH (dest[-1])) + *dest++ = '/'; + + if (dest + (end - start) >= rname_limit) + { + ptrdiff_t dest_offset = dest - rname; + size_t new_size = rname_limit - rname; + + if (end - start + 1 > PATH_MAX) + new_size += end - start + 1; + else + new_size += PATH_MAX; + rname = xrealloc (rname, new_size); + rname_limit = rname + new_size; + + dest = rname + dest_offset; + } + + dest = memcpy (dest, start, end - start); + dest += end - start; + *dest = '\0'; + + if (logical && (can_mode == CAN_MISSING)) + { + /* Avoid the stat in this case as it's inconsequential. + i.e. we're neither resolving symlinks or testing + component existence. */ + st.st_mode = 0; + } + else if ((logical ? stat (rname, &st) : lstat (rname, &st)) != 0) + { + saved_errno = errno; + if (can_mode == CAN_EXISTING) + goto error; + if (can_mode == CAN_ALL_BUT_LAST) + { + if (end[strspn (end, SLASHES)] || saved_errno != ENOENT) + goto error; + continue; + } + st.st_mode = 0; + } + + if (S_ISLNK (st.st_mode)) + { + char *buf; + size_t n, len; + + /* Detect loops. We cannot use the cycle-check module here, + since it's actually possible to encounter the same symlink + more than once in a given traversal. However, encountering + the same symlink,NAME pair twice does indicate a loop. */ + if (seen_triple (&ht, name, &st)) + { + if (can_mode == CAN_MISSING) + continue; + saved_errno = ELOOP; + goto error; + } + + buf = areadlink_with_size (rname, st.st_size); + if (!buf) + { + if (can_mode == CAN_MISSING && errno != ENOMEM) + continue; + saved_errno = errno; + 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 (IS_ABSOLUTE_FILE_NAME (buf)) + { + size_t pfxlen = FILE_SYSTEM_PREFIX_LEN (buf); + + if (pfxlen) + memcpy (rname, buf, pfxlen); + dest = rname + 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++; + } + + free (buf); + } + else + { + if (!S_ISDIR (st.st_mode) && *end && (can_mode != CAN_MISSING)) + { + saved_errno = ENOTDIR; + goto error; + } + } + } } - if (dest > rpath + 1 && dest[-1] == '/') + 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++; *dest = '\0'; + if (rname_limit != dest + 1) + rname = xrealloc (rname, dest - rname + 1); free (extra_buf); - return rpath; + if (ht) + hash_free (ht); + return rname; error: free (extra_buf); - free (rpath); + free (rname); + if (ht) + hash_free (ht); + errno = saved_errno; return NULL; }