[PATCH] No secondary ids

[Neal H Walfield]

idvec_merge_implied_gids (a part of libshouldbeinlibc) only merges in
primary ids and not secondary ids as it should.  This patch corrects
that.  The following is a test program showing what happened before and
after:

#define _GNU_SOURCE 1
#include <stdio.h>
#include <stdlib.h>
#include <idvec.h>

int
main (int argc, char *argv[])
{
  int i;
  char **arg;
  struct idvec *uids = make_idvec ();
  struct idvec *gids = make_idvec ();

  for (arg = &argv[1]; *arg; arg ++)
    idvec_add (uids, atoi (*arg));

  idvec_merge_implied_gids (gids, uids);

  for (i = 0; i < gids->num; i ++)
    printf ("%d ", gids->ids[i]);
  printf ("\n");

  return 0;
}

$ grep neal /etc/group
adm:1bTB8THYRhlbo:4:neal
neal:x:1000:
$ ./idvec-test 1000
1000 
$ ./idvec-test-new 1000
1000 4 

I am also worried about the code to cache the groups associated with an
id: if the program is long running and things change, the cache will
become stale; this should be removed.


diff --exclude CVS -Nur hurd-20010307-snapshot/libshouldbeinlibc/ChangeLog 
hurd-20010313/libshouldbeinlibc/ChangeLog
--- hurd-20010307-snapshot/libshouldbeinlibc/ChangeLog  Sun Feb 25 23:18:19 2001
+++ hurd-20010313/libshouldbeinlibc/ChangeLog   Sat Mar 17 08:44:57 2001
@@ -1,3 +1,9 @@
+2001-03-17  Neal H Walfield  <neal@cs.uml.edu>
+
+       * idvec-impgids.c (idvec_merge_implied_gids):  Add code to
+       check for secondary groups.
+       (_merge): Free cache on failure.
+
 2001-02-25  Roland McGrath  <roland@frob.com>
 
        * idvec.h: Include <string.h> for memcmp decl.
diff --exclude CVS -Nur 
hurd-20010307-snapshot/libshouldbeinlibc/idvec-impgids.c 
hurd-20010313/libshouldbeinlibc/idvec-impgids.c
--- hurd-20010307-snapshot/libshouldbeinlibc/idvec-impgids.c    Wed Aug  6 
22:57:46 1997
+++ hurd-20010313/libshouldbeinlibc/idvec-impgids.c     Sat Mar 17 08:19:00 2001
@@ -20,6 +20,7 @@
 
 #include <stdlib.h>
 #include <errno.h>
+#include <alloca.h>
 #include <idvec.h>
 #include <pwd.h>
 #include <grp.h>
@@ -84,7 +85,11 @@
        if (! cache)
          err = ENOMEM;
        else
-         err = idvec_add_new (cache, pw->pw_gid);
+         {
+           err = idvec_add_new (cache, pw->pw_gid);
+           if (err)
+             idvec_free (cache);
+         }
 #endif
 
        if (! err)
@@ -112,12 +117,49 @@
 idvec_merge_implied_gids (struct idvec *gids, const struct idvec *uids)
 {
   int i;
-  error_t err = 0;
+  error_t initial_err = 0;
+#define ERR(err) \
+       do { if ((err) && ! initial_err) initial_err = err; } while (0)
+
+  if (uids->num == 0)
+    return 0;
+
+  /* Merge the primary group associated with each uid.  */
   for (i = 0; i < uids->num; i++)
-    {
-      error_t this_err = _merge_implied_gids (gids, uids->ids[i]);
-      if (this_err && !err)
-       err = this_err;
-    }
-  return err;
+    ERR (_merge_implied_gids (gids, uids->ids[i]));
+  
+  /* Merge the secondary group associated with each uid.  */
+  {
+    struct group *group;
+    char *names[uids->num];
+    int last_name = 0;
+
+    setgrent ();
+
+    /* getgrent returns a string and we are only given the numerical uids.
+       Build a list of strings from the uids.  */
+    for (i = 0; i < uids->num; i ++)
+      {
+        struct passwd *passwd = getpwuid (uids->ids[i]);
+       if (passwd)
+          names[last_name ++] = strdupa (passwd->pw_name);
+      }
+
+    if (last_name == 0)
+      goto out;
+
+    while ((group = getgrent ()))
+      {
+        char **member;
+       for (i = 0; i < last_name; i ++)
+         for (member = group->gr_mem; *member; member ++)
+           if (strcmp (*member, names[i]) == 0)
+             ERR (idvec_add (gids, group->gr_gid));
+      }
+
+    endgrent ();
+  }
+
+out:
+  return initial_err;
 }

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