Add multiple ../../.. support in sftp-server for changing directories or get/put

Before one could provide only one .. ; now it can be any numbers. cd
../../..  or get ../backup/myfile.c  --- all these formations now work.

Author: quamrulmina

openbsd-compat/realpath.c

@@ -203,101 +203,65 @@ realpath(const char *path, char resolved[PATH_MAX])
 
 #else
 
-char *realpathWin32(const char *path, char resolved[PATH_MAX])
+void backslashconvert(char *str)
 {
-  size_t path_len;
-  unsigned int lastSlash;
-  char realpath[PATH_MAX];
-  char * pch;
+	while (*str) {
+		if (*str == '/')
+			*str = '\\'; // convert forward slash to back slash
+		str++;
+	}
 
-  path_len = strlcpy(realpath, path+1, sizeof(realpath));
+}
 
-  char * pchMac;
-  pchMac = strstr (realpath, "._");
-  if (pchMac != NULL)
-  {
-    pchMac[0] = '\0';
-    pchMac++;
-    pchMac++;
-    strcat(realpath, pchMac);
-  }
+// convert back slash to forward slash
+void slashconvert(char *str)
+{
+	while (*str) {
+		if (*str == '\\')
+			*str = '/'; // convert back slash to forward slash
+		str++;
+	}
+}
 
-  pch = strrchr(realpath, '/');
-  lastSlash =  pch - realpath + 1;
-  if(path_len == lastSlash)
-  {
-    realpath[lastSlash-1] = '\0';
-  }	
+char *realpathWin32(const char *path, char resolved[PATH_MAX])
+{
+	char realpath[PATH_MAX];
 
-  pch = strrchr(realpath,'.');
-  if(pch != NULL)
-  {
-    if (realpath[pch-realpath - 1] == '.')
-    {
-      realpath[pch - realpath - 2] = '\0';	
-      pch = strrchr(realpath, '/');
-      if(pch != NULL)
-        realpath[pch - realpath] = '\0';
-    }
-  }
+	strlcpy(resolved, path + 1, sizeof(realpath));
+	backslashconvert(resolved);
+	PathCanonicalizeA(realpath, resolved);
+	slashconvert(realpath);
 
-  /*
-   * Store terminating slash in 'X:/' on Windows.
-   */
-   
-  if (realpath[1] == ':' && realpath[2] == 0)
-  {
-    realpath[2] = '/';
-    realpath[3] = 0;
-  }
-  
-  resolved[0] = *path; // will be our first slash in /x:/users/test1 format
-  strncpy (resolved+1, realpath, sizeof(realpath));
-  return resolved;	
+	/*
+	* Store terminating slash in 'X:/' on Windows.
+	*/
+
+	if (realpath[1] == ':' && realpath[2] == 0)
+	{
+		realpath[2] = '/';
+		realpath[3] = 0;
+	}
+
+	resolved[0] = *path; // will be our first slash in /x:/users/test1 format
+	strncpy(resolved + 1, realpath, sizeof(realpath));
+	return resolved;
 }
 
+// like realpathWin32() but takes out the first slash so that windows systems can work on the actual file or directory
 char *realpathWin32i(const char *path, char resolved[PATH_MAX])
 {
-	size_t path_len;
-	unsigned int lastSlash;
 	char realpath[PATH_MAX];
-	char * pch;
 
 	if (path[0] != '/') {
 		// absolute form x:/abc/def given, no first slash to take out
-		path_len = strlcpy(realpath, path, sizeof(realpath));
+		strlcpy(resolved, path, sizeof(realpath));
 	}
 	else
-		path_len = strlcpy(realpath, path + 1, sizeof(realpath));
-
-	char * pchMac;
-	pchMac = strstr(realpath, "._");
-	if (pchMac != NULL)
-	{
-		pchMac[0] = '\0';
-		pchMac++;
-		pchMac++;
-		strcat(realpath, pchMac);
-	}
-
-	pch = strrchr(realpath, '/');
-	lastSlash = pch - realpath + 1;
-	if (path_len == lastSlash)
-	{
-		realpath[lastSlash - 1] = '\0';
-	}
+		strlcpy(resolved, path + 1, sizeof(realpath));
 
-	pch = strrchr(realpath, '.');
-	if (pch != NULL)
-	{
-		if (realpath[pch - realpath - 1] == '.')
-		{
-			realpath[pch - realpath - 2] = '\0';
-			pch = strrchr(realpath, '/');
-			if (pch != NULL)
-				realpath[pch - realpath] = '\0';
-		}
-	}
+	backslashconvert(resolved);
+	PathCanonicalizeA(realpath, resolved);
+	slashconvert(realpath);
 
 	/*
 	* Store terminating slash in 'X:/' on Windows.