USER adaptor: localxml

This is the localxml user directory adaptor for the wftk. It encapsulates user directory functionality, storing users and groups as XML files in local directories. The directories in question are determined by the config module using the USER_DIRECTORY and GROUP_DIRECTORY named values.

#include <stdio.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef WINDOWS
#include <io.h>
#endif
#include <errno.h>
#include "xmlapi.h"
#include "../wftk_session.h"
#include "../wftk_internals.h"

The adaptor_info structure is used to pass adaptor info (duh) back to the config module when it's building an adaptor instance. Here's what it contains:

static char *names[] = 
{
   "init",
   "free",
   "info",
   "get",
   "auth",
   "ingroup"
};

XML * USER_localxml_init    (WFTK_ADAPTOR * ad, va_list args);
XML * USER_localxml_free    (WFTK_ADAPTOR * ad, va_list args);
XML * USER_localxml_info    (WFTK_ADAPTOR * ad, va_list args);
XML * USER_localxml_get     (WFTK_ADAPTOR * ad, va_list args);
XML * USER_localxml_auth    (WFTK_ADAPTOR * ad, va_list args);
XML * USER_localxml_ingroup (WFTK_ADAPTOR * ad, va_list args);

static WFTK_API_FUNC vtab[] = 
{
   USER_localxml_init,
   USER_localxml_free,
   USER_localxml_info,
   USER_localxml_get,
   USER_localxml_auth,
   USER_localxml_ingroup
};

static struct wftk_adaptor_info _USER_localxml_info =
{
   6,
   names,
   vtab
};

Cool. So here's the incredibly complex function which returns a pointer to that:

struct wftk_adaptor_info * USER_localxml_get_info ()
{
   return & _USER_localxml_info;
}

Thus concludes the communication with the config module. Now on with the actual implementation of functionality.

XML * USER_localxml_init (WFTK_ADAPTOR * ad, va_list args) {
   struct stat statbuf;
   const char * parms;
   char directory[256];
   char * end;

   parms = xml_attrval (ad->parms, "parm");
   if (!*parms) parms = wftk_config_get_value (ad->session, "user.localxml.directory");

   /* Check for existence, return error if the directory doesn't exist or if it isn't a directory. */
   strcpy (directory, parms);
   end = directory + strlen (directory) - 1;
   if (*end == '\\') *end = '\0';
   if (*end == '/') *end = '\0';

   if (stat (directory, &statbuf) == -1) {
      xml_setf (ad->parms, "error", "Directory '%s' not found.", directory);
      return (XML *) 0;
   }
   if (!(statbuf.st_mode & S_IFDIR)) {
      xml_setf (ad->parms, "error", "Directory '%s' not directory.", directory);
      return (XML *) 0;
   }

   strcat (directory, "/");
   xml_set (ad->parms, "dir", directory);
   strcpy (directory, "localxml:");
   strcat (directory, xml_attrval (ad->parms, "dir"));
   xml_set (ad->parms, "spec", directory);
   return (XML *) 0;
}

That wasn't so hard, was it? Well, freeing up the adaptor is much easier:

XML * USER_localxml_free (WFTK_ADAPTOR * ad, va_list args) { return (XML *) 0; }

Next up is the info call, which builds and returns a little XML telling the caller about the adaptor. If the adaptor itself is NULL, then it just returns info about the installed adaptor handler; otherwise it's free to elaborate on the adaptor instance.

XML * USER_localxml_info (WFTK_ADAPTOR * ad, va_list args) {
   XML * info;

   info = xml_create ("info");
   xml_set (info, "type", "user");
   xml_set (info, "name", "localxml");
   xml_set (info, "ver", "1.0.0");
   xml_set (info, "compiled", __TIME__ " " __DATE__);
   xml_set (info, "author", "Michael Roberts");
   xml_set (info, "contact", "wftk@vivtek.com");
   xml_set (info, "extra_functions", "0");

   return (info);
}

We've got two functions in the user adaptor, one to retrieve a descriptive XML file (which will, at least at first, just be the user entry itself), and one to authenticate a password against a user. For the time being we're going to be really slipshod about that last, and just store the password in plaintext. Post-v1.0 (sigh) we'll want to at least encrypt the password or something. Or just switch to LDAP.

November 25, 2002: OK. This model is stupid. On my second approach (more than a year later) whilst adding user auth to the repository manager, I realize that really for authentication I want to pass the user's ID in to authenticate -- not the entire user definition, which I may not have. This gives a lot more leeway to the adaptor to implement authentication correctly.

I also see that this code is really, really old. Frankly, I don't care about it much; it's just going to be the default for the wftk-core configuration, and any repmgr system is going to ignore it completely in favor of the repository manager list implementation. So I'm not going to waste any time bringing it up to date. If you're actually using the wftk-core configuration, well, congratulations -- you've found another place to try out your debugging skills!

XML * USER_localxml_get (WFTK_ADAPTOR * ad, va_list args) {
   char path[256];
   char *id = (char *) 0;
   FILE *file;
   XML * ret;

   if (args) id = va_arg (args, char *);
   if (!id) {
      xml_set (ad->parms, "error", "No ID given.");
      return (XML *) 0;
   }

   strcpy (path, xml_attrval (ad->parms, "dir"));
   strcat (path, id);
   strcat (path, ".xml");
   file = fopen (path, "r");
   if (!file) {
      xml_setf (ad->parms, "error", "Couldn't open file '%s' for reading.", path);
      return (XML *) 0;
   }

   ret = xml_read (file);
   fclose (file);

   return ret;

}

XML * USER_localxml_auth (WFTK_ADAPTOR * ad, va_list args) {
   char * userid = NULL;
   XML * user = 0;
   char * password;
   char path[256];
   FILE * file;

   if (args) userid = va_arg (args, char *);
   if (!userid) {
      xml_set (ad->parms, "error", "No user given.");
      return (XML *) 0;
   }
   password = va_arg (args, char *);

   strcpy (path, xml_attrval (ad->parms, "dir"));
   strcat (path, userid);
   strcat (path, ".xml");
   file = fopen (path, "r");
   if (!file) {
      xml_setf (ad->parms, "error", "Couldn't open file '%s' for reading.", path);
      return (XML *) 0;
   }

   user = xml_read (file);
   fclose (file);

   if (!strcmp (password, xml_attrval (user, "password"))) return user;
   xml_free (user);
   return (XML *) 0;
}

(November 25, 2002) Also I realize I need an in-group function to test group membership. The localxml adaptor is so stupid that it doesn't really implement groups yet. So I punt.

XML * USER_localxml_ingroup (WFTK_ADAPTOR * ad, va_list args) {
   return (XML *) 0;
}

This code and documentation are released under the terms of the GNU license. They are additionally copyright (c) 2000, Vivtek. All rights reserved except those explicitly granted under the terms of the GNU license. This presentation was prepared with LPML. Try literate programming. You'll like it.