X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/b5bd5542eb99f97561848113887d100b83e9bc43..74de13d19c5c9bd1d7d1acde810fcb5bd398a359:/util.c
diff --git a/util.c b/util.c
index f2158a02..9ebd6ba7 100644
--- a/util.c
+++ b/util.c
@@ -31,7 +31,8 @@ extern int verbose;
extern int dry_run;
extern int module_id;
extern int modify_window;
-extern struct exclude_list_struct server_exclude_list;
+extern char *partial_dir;
+extern struct filter_list_struct server_filter_list;
int sanitize_paths = 0;
@@ -78,7 +79,7 @@ int fd_pair(int fd[2])
{
int ret;
-#if HAVE_SOCKETPAIR
+#ifdef HAVE_SOCKETPAIR
ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fd);
#else
ret = pipe(fd);
@@ -104,9 +105,9 @@ void print_child_argv(char **cmd)
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"0123456789"
",.-_=+@/") != strlen(*cmd)) {
- rprintf(FINFO, "\"%s\" ", *cmd);
+ rprintf(FINFO, "\"%s\" ", safe_fname(*cmd));
} else {
- rprintf(FINFO, "%s ", *cmd);
+ rprintf(FINFO, "%s ", safe_fname(*cmd));
}
}
rprintf(FINFO, "\n");
@@ -119,7 +120,7 @@ void out_of_memory(char *str)
exit_cleanup(RERR_MALLOC);
}
-void overflow(char *str)
+void overflow_exit(char *str)
{
rprintf(FERROR, "ERROR: buffer overflow in %s\n", str);
exit_cleanup(RERR_MALLOC);
@@ -127,35 +128,46 @@ void overflow(char *str)
-int set_modtime(char *fname, time_t modtime)
+int set_modtime(char *fname, time_t modtime, mode_t mode)
{
- if (dry_run)
- return 0;
+#if !defined HAVE_LUTIMES || !defined HAVE_UTIMES
+ if (S_ISLNK(mode))
+ return 1;
+#endif
if (verbose > 2) {
rprintf(FINFO, "set modtime of %s to (%ld) %s",
- fname, (long)modtime,
+ safe_fname(fname), (long)modtime,
asctime(localtime(&modtime)));
}
+ if (dry_run)
+ return 0;
+
{
-#ifdef HAVE_UTIMBUF
+#ifdef HAVE_UTIMES
+ struct timeval t[2];
+ t[0].tv_sec = time(NULL);
+ t[0].tv_usec = 0;
+ t[1].tv_sec = modtime;
+ t[1].tv_usec = 0;
+# ifdef HAVE_LUTIMES
+ if (S_ISLNK(mode))
+ return lutimes(fname, t);
+# endif
+ return utimes(fname, t);
+#elif defined HAVE_UTIMBUF
struct utimbuf tbuf;
tbuf.actime = time(NULL);
tbuf.modtime = modtime;
return utime(fname,&tbuf);
-#elif defined(HAVE_UTIME)
+#elif defined HAVE_UTIME
time_t t[2];
t[0] = time(NULL);
t[1] = modtime;
return utime(fname,t);
#else
- struct timeval t[2];
- t[0].tv_sec = time(NULL);
- t[0].tv_usec = 0;
- t[1].tv_sec = modtime;
- t[1].tv_usec = 0;
- return utimes(fname,t);
+#error No file-time-modification routine found!
#endif
}
}
@@ -196,7 +208,7 @@ int create_directory_path(char *fname, int base_umask)
*
* Derived from GNU C's cccp.c.
*/
-static int full_write(int desc, char *ptr, size_t len)
+int full_write(int desc, char *ptr, size_t len)
{
int total_written;
@@ -244,7 +256,8 @@ static int safe_read(int desc, char *ptr, size_t len)
/** Copy a file.
*
- * This is used in conjunction with the --temp-dir option */
+ * This is used in conjunction with the --temp-dir, --backup, and
+ * --copy-dest options. */
int copy_file(char *source, char *dest, mode_t mode)
{
int ifd;
@@ -349,7 +362,7 @@ int robust_unlink(char *fname)
if (verbose > 0) {
rprintf(FINFO,"renaming %s to %s because of text busy\n",
- fname, path);
+ safe_fname(fname), safe_fname(path));
}
/* maybe we should return rename()'s exit status? Nah. */
@@ -361,8 +374,8 @@ int robust_unlink(char *fname)
#endif
}
-/* Returns 0 on success, -1 on most errors, and -2 if we got an error
- * trying to copy the file across file systems. */
+/* Returns 0 on successful rename, 1 if we successfully copied the file
+ * across filesystems, -2 if copy_file() failed, and -1 on other errors. */
int robust_rename(char *from, char *to, int mode)
{
int tries = 4;
@@ -382,7 +395,7 @@ int robust_rename(char *from, char *to, int mode)
if (copy_file(from, to, mode) != 0)
return -2;
do_unlink(from);
- return 0;
+ return 1;
default:
return -1;
}
@@ -478,14 +491,14 @@ int lock_range(int fd, int offset, int len)
return fcntl(fd,F_SETLK,&lock) == 0;
}
-static int exclude_server_path(char *arg)
+static int filter_server_path(char *arg)
{
char *s;
- if (server_exclude_list.head) {
+ if (server_filter_list.head) {
for (s = arg; (s = strchr(s, '/')) != NULL; ) {
*s = '\0';
- if (check_exclude(&server_exclude_list, arg, 1) < 0) {
+ if (check_filter(&server_filter_list, arg, 1) < 0) {
/* We must leave arg truncated! */
return 1;
}
@@ -495,40 +508,53 @@ static int exclude_server_path(char *arg)
return 0;
}
-static void glob_expand_one(char *s, char **argv, int *argc_ptr, int maxargs)
+static void glob_expand_one(char *s, char ***argv_ptr, int *argc_ptr,
+ int *maxargs_ptr)
{
+ char **argv = *argv_ptr;
int argc = *argc_ptr;
-#if !(defined(HAVE_GLOB) && defined(HAVE_GLOB_H))
- if (maxargs <= argc)
- return;
+ int maxargs = *maxargs_ptr;
+#if !defined HAVE_GLOB || !defined HAVE_GLOB_H
+ if (argc == maxargs) {
+ maxargs += MAX_ARGS;
+ if (!(argv = realloc_array(argv, char *, maxargs)))
+ out_of_memory("glob_expand_one");
+ *argv_ptr = argv;
+ *maxargs_ptr = maxargs;
+ }
if (!*s)
s = ".";
s = argv[argc++] = strdup(s);
- exclude_server_path(s);
+ filter_server_path(s);
#else
glob_t globbuf;
- int i;
if (maxargs <= argc)
return;
if (!*s)
s = ".";
- s = strdup(s);
if (sanitize_paths)
- sanitize_path(s, NULL);
+ s = sanitize_path(NULL, s, "", 0);
+ else
+ s = strdup(s);
memset(&globbuf, 0, sizeof globbuf);
- if (!exclude_server_path(s))
+ if (!filter_server_path(s))
glob(s, 0, NULL, &globbuf);
+ if (MAX((int)globbuf.gl_pathc, 1) > maxargs - argc) {
+ maxargs += globbuf.gl_pathc + MAX_ARGS;
+ if (!(argv = realloc_array(argv, char *, maxargs)))
+ out_of_memory("glob_expand_one");
+ *argv_ptr = argv;
+ *maxargs_ptr = maxargs;
+ }
if (globbuf.gl_pathc == 0)
argv[argc++] = s;
else {
- int j = globbuf.gl_pathc;
- if (j > maxargs - argc)
- j = maxargs - argc;
+ int i;
free(s);
- for (i = 0; i < j; i++) {
+ for (i = 0; i < (int)globbuf.gl_pathc; i++) {
if (!(argv[argc++] = strdup(globbuf.gl_pathv[i])))
out_of_memory("glob_expand_one");
}
@@ -539,9 +565,9 @@ static void glob_expand_one(char *s, char **argv, int *argc_ptr, int maxargs)
}
/* This routine is only used in daemon mode. */
-void glob_expand(char *base1, char **argv, int *argc_ptr, int maxargs)
+void glob_expand(char *base1, char ***argv_ptr, int *argc_ptr, int *maxargs_ptr)
{
- char *s = argv[*argc_ptr];
+ char *s = (*argv_ptr)[*argc_ptr];
char *p, *q;
char *base = base1;
int base_len = strlen(base);
@@ -562,7 +588,7 @@ void glob_expand(char *base1, char **argv, int *argc_ptr, int maxargs)
for (q = s; *q; q = p + base_len) {
if ((p = strstr(q, base)) != NULL)
*p = '\0'; /* split it at this point */
- glob_expand_one(q, argv, argc_ptr, maxargs);
+ glob_expand_one(q, argv_ptr, argc_ptr, maxargs_ptr);
if (!p)
break;
}
@@ -635,122 +661,143 @@ size_t stringjoin(char *dest, size_t destsize, ...)
return ret;
}
-void clean_fname(char *name)
+int count_dir_elements(const char *p)
{
- char *p;
- int l;
- int modified = 1;
+ int cnt = 0, new_component = 1;
+ while (*p) {
+ if (*p++ == '/')
+ new_component = 1;
+ else if (new_component) {
+ new_component = 0;
+ cnt++;
+ }
+ }
+ return cnt;
+}
- if (!name)
- return;
+/* Turns multiple adjacent slashes into a single slash, gets rid of "./"
+ * elements (but not a trailing dot dir), removes a trailing slash, and
+ * optionally collapses ".." elements (except for those at the start of the
+ * string). If the resulting name would be empty, change it into a ".". */
+unsigned int clean_fname(char *name, BOOL collapse_dot_dot)
+{
+ char *limit = name - 1, *t = name, *f = name;
+ int anchored;
- while (modified) {
- modified = 0;
+ if (!name)
+ return 0;
- if ((p = strstr(name,"/./")) != NULL) {
- modified = 1;
- while (*p) {
- p[0] = p[2];
- p++;
- }
+ if ((anchored = *f == '/') != 0)
+ *t++ = *f++;
+ while (*f) {
+ /* discard extra slashes */
+ if (*f == '/') {
+ f++;
+ continue;
}
-
- if ((p = strstr(name,"//")) != NULL) {
- modified = 1;
- while (*p) {
- p[0] = p[1];
- p++;
+ if (*f == '.') {
+ /* discard "." dirs (but NOT a trailing '.'!) */
+ if (f[1] == '/') {
+ f += 2;
+ continue;
+ }
+ /* collapse ".." dirs */
+ if (collapse_dot_dot
+ && f[1] == '.' && (f[2] == '/' || !f[2])) {
+ char *s = t - 1;
+ if (s == name && anchored) {
+ f += 2;
+ continue;
+ }
+ while (s > limit && *--s != '/') {}
+ if (s != t - 1 && (s < name || *s == '/')) {
+ t = s + 1;
+ f += 2;
+ continue;
+ }
+ limit = t + 2;
}
}
+ while (*f && (*t++ = *f++) != '/') {}
+ }
- if (strncmp(p = name, "./", 2) == 0) {
- modified = 1;
- do {
- p[0] = p[2];
- } while (*p++);
- }
+ if (t > name+anchored && t[-1] == '/')
+ t--;
+ if (t == name)
+ *t++ = '.';
+ *t = '\0';
- l = strlen(p = name);
- if (l > 1 && p[l-1] == '/') {
- modified = 1;
- p[l-1] = 0;
- }
- }
+ return t - name;
}
-/**
- * Make path appear as if a chroot had occurred:
+/* Make path appear as if a chroot had occurred. This handles a leading
+ * "/" (either removing it or expanding it) and any leading or embedded
+ * ".." components that attempt to escape past the module's top dir.
*
- * @li 1. remove leading "/" (or replace with "." if at end)
+ * If dest is NULL, a buffer is allocated to hold the result. It is legal
+ * to call with the dest and the path (p) pointing to the same buffer, but
+ * rootdir will be ignored to avoid expansion of the string.
*
- * @li 2. remove leading ".." components (except those allowed by @p reldir)
+ * The rootdir string contains a value to use in place of a leading slash.
+ * Specify NULL to get the default of lp_path(module_id).
*
- * @li 3. delete any other "
/.." (recursively)
+ * If depth is >= 0, it is a count of how many '..'s to allow at the start
+ * of the path. Use -1 to allow unlimited depth.
*
- * Can only shrink paths, so sanitizes in place.
+ * We also clean the path in a manner similar to clean_fname() but with a
+ * few differences:
*
- * While we're at it, remove double slashes and "." components like
- * clean_fname() does, but DON'T remove a trailing slash because that
- * is sometimes significant on command line arguments.
- *
- * If @p reldir is non-null, it is a sanitized directory that the path will be
- * relative to, so allow as many ".." at the beginning of the path as
- * there are components in reldir. This is used for symbolic link targets.
- * If reldir is non-null and the path began with "/", to be completely like
- * a chroot we should add in depth levels of ".." at the beginning of the
- * path, but that would blow the assumption that the path doesn't grow and
- * it is not likely to end up being a valid symlink anyway, so just do
- * the normal removal of the leading "/" instead.
- *
- * Contributed by Dave Dykstra
- */
-void sanitize_path(char *p, char *reldir)
+ * Turns multiple adjacent slashes into a single slash, gets rid of "." dir
+ * elements (INCLUDING a trailing dot dir), PRESERVES a trailing slash, and
+ * ALWAYS collapses ".." elements (except for those at the start of the
+ * string up to "depth" deep). If the resulting name would be empty,
+ * change it into a ".". */
+char *sanitize_path(char *dest, const char *p, const char *rootdir, int depth)
{
char *start, *sanp;
- int depth = 0;
- int allowdotdot = 0;
-
- if (reldir) {
- int new_component = 1;
- while (*reldir) {
- if (*reldir++ == '/')
- new_component = 1;
- else if (new_component) {
- new_component = 0;
- depth++;
- }
+ int rlen = 0;
+
+ if (dest != p) {
+ int plen = strlen(p);
+ if (*p == '/') {
+ if (!rootdir)
+ rootdir = lp_path(module_id);
+ rlen = strlen(rootdir);
+ depth = 0;
+ p++;
+ }
+ if (dest) {
+ if (rlen + plen + 1 >= MAXPATHLEN)
+ return NULL;
+ } else if (!(dest = new_array(char, rlen + plen + 1)))
+ out_of_memory("sanitize_path");
+ if (rlen) {
+ memcpy(dest, rootdir, rlen);
+ if (rlen > 1)
+ dest[rlen++] = '/';
}
}
- start = p;
- sanp = p;
- while (*p == '/') {
- /* remove leading slashes */
- p++;
- }
+
+ start = sanp = dest + rlen;
while (*p != '\0') {
+ /* discard leading or extra slashes */
+ if (*p == '/') {
+ p++;
+ continue;
+ }
/* this loop iterates once per filename component in p.
* both p (and sanp if the original had a slash) should
* always be left pointing after a slash
*/
if (*p == '.' && (p[1] == '/' || p[1] == '\0')) {
/* skip "." component */
- while (*++p == '/') {
- /* skip following slashes */
- ;
- }
+ p++;
continue;
}
- allowdotdot = 0;
if (*p == '.' && p[1] == '.' && (p[2] == '/' || p[2] == '\0')) {
/* ".." component followed by slash or end */
- if (depth > 0 && sanp == start) {
- /* allow depth levels of .. at the beginning */
- --depth;
- allowdotdot = 1;
- } else {
+ if (depth <= 0 || sanp != start) {
p += 2;
- if (*p == '/')
- p++;
if (sanp != start) {
/* back up sanp one level */
--sanp; /* now pointing at slash */
@@ -761,68 +808,21 @@ void sanitize_path(char *p, char *reldir)
}
continue;
}
- }
- while (1) {
- /* copy one component through next slash */
- *sanp++ = *p++;
- if (*p == '\0' || p[-1] == '/') {
- while (*p == '/') {
- /* skip multiple slashes */
- p++;
- }
- break;
- }
- }
- if (allowdotdot) {
+ /* allow depth levels of .. at the beginning */
+ depth--;
/* move the virtual beginning to leave the .. alone */
- start = sanp;
+ start = sanp + 3;
}
+ /* copy one component through next slash */
+ while (*p && (*sanp++ = *p++) != '/') {}
}
- if (sanp == start && !allowdotdot) {
+ if (sanp == dest) {
/* ended up with nothing, so put in "." component */
- /*
- * note that the !allowdotdot doesn't prevent this from
- * happening in all allowed ".." situations, but I didn't
- * think it was worth putting in an extra variable to ensure
- * it since an extra "." won't hurt in those situations.
- */
*sanp++ = '.';
}
*sanp = '\0';
-}
-/* Works much like sanitize_path(), with these differences: (1) a new buffer
- * is allocated for the sanitized path rather than modifying it in-place; (2)
- * a leading slash gets transformed into the rootdir value (which can be empty
- * or NULL if you just want the slash to get dropped); (3) no "reldir" can be
- * specified. */
-char *alloc_sanitize_path(const char *path, const char *rootdir)
-{
- char *buf;
- int rlen, plen = strlen(path);
-
- if (*path == '/' && rootdir) {
- rlen = strlen(rootdir);
- if (rlen == 1)
- path++;
- } else
- rlen = 0;
- if (!(buf = new_array(char, rlen + plen + 1)))
- out_of_memory("alloc_sanitize_path");
- if (rlen)
- memcpy(buf, rootdir, rlen);
- memcpy(buf + rlen, path, plen + 1);
-
- if (rlen > 1)
- rlen++;
- sanitize_path(buf + rlen, NULL);
- if (rlen && buf[rlen] == '.' && buf[rlen+1] == '\0') {
- if (rlen > 1)
- rlen--;
- buf[rlen] = '\0';
- }
-
- return buf;
+ return dest;
}
char curr_dir[MAXPATHLEN];
@@ -866,7 +866,7 @@ int push_dir(char *dir)
curr_dir_len += len;
}
- clean_fname(curr_dir);
+ curr_dir_len = clean_fname(curr_dir, 1);
return 1;
}
@@ -887,6 +887,43 @@ int pop_dir(char *dir)
return 1;
}
+/* Return the filename, turning any non-printable characters into escaped
+ * characters (e.g. \n -> \012, \ -> \\). This ensures that outputting it
+ * cannot generate an empty line nor corrupt the screen. This function can
+ * return only MAX_SAFE_NAMES values at a time! The returned value can be
+ * longer than MAXPATHLEN (because we may be trying to output an error about
+ * a too-long filename)! */
+char *safe_fname(const char *fname)
+{
+#define MAX_SAFE_NAMES 4
+ static char fbuf[MAX_SAFE_NAMES][MAXPATHLEN*2];
+ static int ndx = 0;
+ int limit = sizeof fbuf / MAX_SAFE_NAMES - 1;
+ char *t;
+
+ ndx = (ndx + 1) % MAX_SAFE_NAMES;
+ for (t = fbuf[ndx]; *fname; fname++) {
+ if (*fname == '\\') {
+ if ((limit -= 2) < 0)
+ break;
+ *t++ = '\\';
+ *t++ = '\\';
+ } else if (!isprint(*(uchar*)fname)) {
+ if ((limit -= 4) < 0)
+ break;
+ sprintf(t, "\\%03o", *(uchar*)fname);
+ t += 4;
+ } else {
+ if (--limit < 0)
+ break;
+ *t++ = *fname;
+ }
+ }
+ *t = '\0';
+
+ return fbuf[ndx];
+}
+
/**
* Return a quoted string with the full pathname of the indicated filename.
* The string " (in MODNAME)" may also be appended. The returned pointer
@@ -901,29 +938,26 @@ char *full_fname(const char *fn)
if (result)
free(result);
+ fn = safe_fname(fn);
if (*fn == '/')
p1 = p2 = "";
else {
p1 = curr_dir;
- p2 = "/";
+ for (p2 = p1; *p2 == '/'; p2++) {}
+ if (*p2)
+ p2 = "/";
}
if (module_id >= 0) {
m1 = " (in ";
m2 = lp_name(module_id);
m3 = ")";
- if (*p1) {
+ if (p1 == curr_dir) {
if (!lp_use_chroot(module_id)) {
char *p = lp_path(module_id);
if (*p != '/' || p[1])
p1 += strlen(p);
}
- if (!*p1)
- p2++;
- else
- p1++;
}
- else
- fn++;
} else
m1 = m2 = m3 = "";
@@ -932,6 +966,73 @@ char *full_fname(const char *fn)
return result;
}
+static char partial_fname[MAXPATHLEN];
+
+char *partial_dir_fname(const char *fname)
+{
+ char *t = partial_fname;
+ int sz = sizeof partial_fname;
+ const char *fn;
+
+ if ((fn = strrchr(fname, '/')) != NULL) {
+ fn++;
+ if (*partial_dir != '/') {
+ int len = fn - fname;
+ strncpy(t, fname, len); /* safe */
+ t += len;
+ sz -= len;
+ }
+ } else
+ fn = fname;
+ if ((int)pathjoin(t, sz, partial_dir, fn) >= sz)
+ return NULL;
+ if (server_filter_list.head) {
+ static int len;
+ if (!len)
+ len = strlen(partial_dir);
+ t[len] = '\0';
+ if (check_filter(&server_filter_list, partial_fname, 1) < 0)
+ return NULL;
+ t[len] = '/';
+ if (check_filter(&server_filter_list, partial_fname, 0) < 0)
+ return NULL;
+ }
+
+ return partial_fname;
+}
+
+/* If no --partial-dir option was specified, we don't need to do anything
+ * (the partial-dir is essentially '.'), so just return success. */
+int handle_partial_dir(const char *fname, int create)
+{
+ char *fn, *dir;
+
+ if (fname != partial_fname)
+ return 1;
+ if (!create && *partial_dir == '/')
+ return 1;
+ if (!(fn = strrchr(partial_fname, '/')))
+ return 1;
+
+ *fn = '\0';
+ dir = partial_fname;
+ if (create) {
+ STRUCT_STAT st;
+ int statret = do_lstat(dir, &st);
+ if (statret == 0 && !S_ISDIR(st.st_mode)) {
+ if (do_unlink(dir) < 0)
+ return 0;
+ statret = -1;
+ }
+ if (statret < 0 && do_mkdir(dir, 0700) < 0)
+ return 0;
+ } else
+ do_rmdir(dir);
+ *fn = '/';
+
+ return 1;
+}
+
/** We need to supply our own strcmp function for file list comparisons
to ensure that signed/unsigned usage is consistent between machines. */
int u_strcmp(const char *cs1, const char *cs2)
@@ -1140,3 +1241,110 @@ void *_realloc_array(void *ptr, unsigned int size, unsigned long num)
return malloc(size * num);
return realloc(ptr, size * num);
}
+
+/* Take a filename and filename length and return the most significant
+ * filename suffix we can find. This ignores suffixes such as "~",
+ * ".bak", ".orig", ".~1~", etc. */
+const char *find_filename_suffix(const char *fn, int fn_len, int *len_ptr)
+{
+ const char *suf, *s;
+ BOOL had_tilde;
+ int s_len;
+
+ /* One or more dots at the start aren't a suffix. */
+ while (fn_len && *fn == '.') fn++, fn_len--;
+
+ /* Ignore the ~ in a "foo~" filename. */
+ if (fn_len > 1 && fn[fn_len-1] == '~')
+ fn_len--, had_tilde = True;
+ else
+ had_tilde = False;
+
+ /* Assume we don't find an suffix. */
+ suf = "";
+ *len_ptr = 0;
+
+ /* Find the last significant suffix. */
+ for (s = fn + fn_len; fn_len > 1; ) {
+ while (*--s != '.' && s != fn) {}
+ if (s == fn)
+ break;
+ s_len = fn_len - (s - fn);
+ fn_len = s - fn;
+ if (s_len == 4) {
+ if (strcmp(s+1, "bak") == 0
+ || strcmp(s+1, "old") == 0)
+ continue;
+ } else if (s_len == 5) {
+ if (strcmp(s+1, "orig") == 0)
+ continue;
+ } else if (s_len > 2 && had_tilde
+ && s[1] == '~' && isdigit(*(uchar*)(s+2)))
+ continue;
+ *len_ptr = s_len;
+ suf = s;
+ if (s_len == 1)
+ break;
+ /* Determine if the suffix is all digits. */
+ for (s++, s_len--; s_len > 0; s++, s_len--) {
+ if (!isdigit(*(uchar*)s))
+ return suf;
+ }
+ /* An all-digit suffix may not be that signficant. */
+ s = suf;
+ }
+
+ return suf;
+}
+
+/* This is an implementation of the Levenshtein distance algorithm. It
+ * was implemented to avoid needing a two-dimensional matrix (to save
+ * memory). It was also tweaked to try to factor in the ASCII distance
+ * between changed characters as a minor distance quantity. The normal
+ * Levenshtein units of distance (each signifying a single change between
+ * the two strings) are defined as a "UNIT". */
+
+#define UNIT (1 << 16)
+
+uint32 fuzzy_distance(const char *s1, int len1, const char *s2, int len2)
+{
+ uint32 a[MAXPATHLEN], diag, above, left, diag_inc, above_inc, left_inc;
+ int32 cost;
+ int i1, i2;
+
+ if (!len1 || !len2) {
+ if (!len1) {
+ s1 = s2;
+ len1 = len2;
+ }
+ for (i1 = 0, cost = 0; i1 < len1; i1++)
+ cost += s1[i1];
+ return (int32)len1 * UNIT + cost;
+ }
+
+ for (i2 = 0; i2 < len2; i2++)
+ a[i2] = (i2+1) * UNIT;
+
+ for (i1 = 0; i1 < len1; i1++) {
+ diag = i1 * UNIT;
+ above = (i1+1) * UNIT;
+ for (i2 = 0; i2 < len2; i2++) {
+ left = a[i2];
+ if ((cost = *((uchar*)s1+i1) - *((uchar*)s2+i2)) != 0) {
+ if (cost < 0)
+ cost = UNIT - cost;
+ else
+ cost = UNIT + cost;
+ }
+ diag_inc = diag + cost;
+ left_inc = left + UNIT + *((uchar*)s1+i1);
+ above_inc = above + UNIT + *((uchar*)s2+i2);
+ a[i2] = above = left < above
+ ? (left_inc < diag_inc ? left_inc : diag_inc)
+ : (above_inc < diag_inc ? above_inc : diag_inc);
+ diag = left;
+ }
+ }
+
+ return a[len2-1];
+}