X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fcanonicalize.c;h=2b94ebc03529f97132a91fdf55077b15d6ceae68;hb=cd56634a4a8179fd5a4419fbb3e27211b042ab1c;hp=2f008e0689a369f1486113704765ce1fc18a4707;hpb=441aa3044f43e5572f58c354f01e6bc070acd5c7;p=gnulib.git diff --git a/lib/canonicalize.c b/lib/canonicalize.c index 2f008e068..2b94ebc03 100644 --- a/lib/canonicalize.c +++ b/lib/canonicalize.c @@ -1,5 +1,5 @@ /* Return the canonical absolute name of a given file. - Copyright (C) 1996-2009 Free Software Foundation, Inc. + Copyright (C) 1996-2014 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 @@ -30,15 +30,30 @@ #include "pathmax.h" #include "xalloc.h" #include "xgetcwd.h" +#include "dosname.h" + +#define MULTIPLE_BITS_SET(i) (((i) & ((i) - 1)) != 0) + +/* 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 #ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT # define DOUBLE_SLASH_IS_DISTINCT_ROOT 0 #endif +#if ISSLASH ('\\') +# define SLASHES "/\\" +#else +# define SLASHES "/" +#endif + #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 file name + does not contain any ".", ".." components nor any repeated file name separators ('/') or symlinks. All components must exist. The result is malloc'd. */ @@ -75,9 +90,10 @@ seen_triple (Hash_table **ht, char const *filename, struct stat const *st) /* 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 symlinks. Whether components must exist - or not depends on canonicalize mode. The result is malloc'd. */ + 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) @@ -89,6 +105,17 @@ canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode) size_t extra_len = 0; 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) { @@ -102,7 +129,11 @@ canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode) 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)) { rname = xgetcwd (); if (!rname) @@ -119,25 +150,37 @@ canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode) { rname_limit = dest; } + start = name; + prefix_len = FILE_SYSTEM_PREFIX_LEN (rname); } else { rname = xmalloc (PATH_MAX); rname_limit = rname + PATH_MAX; - rname[0] = '/'; - dest = rname + 1; - if (DOUBLE_SLASH_IS_DISTINCT_ROOT && name[1] == '/') - *dest++ = '/'; + 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; } - for (start = name; *start; start = end) + for ( ; *start; start = end) { /* Skip sequence of multiple file name separators. */ - while (*start == '/') + while (ISSLASH (*start)) ++start; /* Find end of component. */ - for (end = start; *end && *end != '/'; ++end) + for (end = start; *end && !ISSLASH (*end); ++end) /* Nothing. */; if (end - start == 0) @@ -147,17 +190,18 @@ canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode) else if (end - start == 2 && start[0] == '.' && start[1] == '.') { /* Back up to previous component, ignore if at root already. */ - if (dest > rname + 1) - while ((--dest)[-1] != '/'); + if (dest > rname + prefix_len + 1) + for (--dest; dest > rname && !ISSLASH (dest[-1]); --dest) + continue; if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1 - && *dest == '/') + && !prefix_len && ISSLASH (*dest) && !ISSLASH (dest[1])) dest++; } else { struct stat st; - if (dest[-1] != '/') + if (!ISSLASH (dest[-1])) *dest++ = '/'; if (dest + (end - start) >= rname_limit) @@ -179,14 +223,21 @@ canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode) dest += end - start; *dest = '\0'; - if (lstat (rname, &st) != 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, "/")] || saved_errno != ENOENT) + if (end[strspn (end, SLASHES)] || saved_errno != ENOENT) goto error; continue; } @@ -238,20 +289,32 @@ canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode) memmove (&extra_buf[n], end, len + 1); name = end = memcpy (extra_buf, buf, n); - if (buf[0] == '/') + if (IS_ABSOLUTE_FILE_NAME (buf)) { - dest = rname + 1; /* It's an absolute symlink */ - if (DOUBLE_SLASH_IS_DISTINCT_ROOT && buf[1] == '/') - *dest++ = '/'; + 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 + 1) - while ((--dest)[-1] != '/'); + if (dest > rname + prefix_len + 1) + for (--dest; dest > rname && !ISSLASH (dest[-1]); --dest) + continue; if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 1 - && *dest == '/') + && ISSLASH (*dest) && !ISSLASH (dest[1]) && !prefix_len) dest++; } @@ -267,11 +330,14 @@ canonicalize_filename_mode (const char *name, canonicalize_mode_t can_mode) } } } - if (dest > rname + 1 && dest[-1] == '/') + if (dest > rname + prefix_len + 1 && ISSLASH (dest[-1])) --dest; - if (DOUBLE_SLASH_IS_DISTINCT_ROOT && dest == rname + 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); if (ht)