commit dd3022d75e6fb8957843d6d84257a5d8457822d5

Author: Siddhesh Poyarekar <siddhesh@redhat.com>

Date:   Thu Mar 27 19:49:51 2014 +0530

    Return NULL for wildcard values in getnetgrent from nscd (BZ #16759)

    getnetgrent is supposed to return NULL for values that are wildcards

    in the (host, user, domain) triplet.  This works correctly with nscd

    disabled, but with it enabled, it returns a blank ("") instead of a

    NULL.  This is easily seen with the output of `getent netgroup foonet`

    for a netgroup foonet defined as follows in /etc/netgroup:

        foonet (,foo,)

    The output with nscd disabled is:

        foonet ( ,foo,)

    while with nscd enabled, it is:

        foonet (,foo,)

    The extra space with nscd disabled is due to the fact that `getent

    netgroup` adds it if the return value from getnetgrent is NULL for

    either host or user.

diff --git glibc-2.17-c758a686/inet/getnetgrent_r.c glibc-2.17-c758a686/inet/getnetgrent_r.c

index 62cdfda..f6d064d 100644

--- glibc-2.17-c758a686/inet/getnetgrent_r.c

+++ glibc-2.17-c758a686/inet/getnetgrent_r.c

@@ -235,6 +235,14 @@ endnetgrent (void)

   __libc_lock_unlock (lock);

 }

+static const char *

+get_nonempty_val (const char *in)

+{

+  if (*in == '\0')

+    return NULL;

+  return in;

+}

+

 #ifdef USE_NSCD

 static enum nss_status

 nscd_getnetgrent (struct __netgrent *datap, char *buffer, size_t buflen,

@@ -243,11 +251,11 @@ nscd_getnetgrent (struct __netgrent *datap, char *buffer, size_t buflen,

     return NSS_STATUS_UNAVAIL;

   datap->type = triple_val;

-  datap->val.triple.host = datap->cursor;

+  datap->val.triple.host = get_nonempty_val (datap->cursor);

   datap->cursor = (char *) __rawmemchr (datap->cursor, '\0') + 1;

-  datap->val.triple.user = datap->cursor;

+  datap->val.triple.user = get_nonempty_val (datap->cursor);

   datap->cursor = (char *) __rawmemchr (datap->cursor, '\0') + 1;

-  datap->val.triple.domain = datap->cursor;

+  datap->val.triple.domain = get_nonempty_val (datap->cursor);

   datap->cursor = (char *) __rawmemchr (datap->cursor, '\0') + 1;

   return NSS_STATUS_SUCCESS;