Paul forgot probably to commit privs.[c|h] changes. Had to reorder includes
in zebra.h to make it compile in debian.
diff --git a/lib/privs.c b/lib/privs.c
index 35e5a76..f3a15ce 100644
--- a/lib/privs.c
+++ b/lib/privs.c
@@ -25,7 +25,6 @@
 #include "log.h"
 #include "privs.h"
 #include "memory.h"
-       
 
 /* internal privileges state */
 static struct _zprivs_t
@@ -40,6 +39,7 @@
   uid_t zuid,                 /* uid to run as            */
         zsuid;                /* saved uid                */
   gid_t zgid;                 /* gid to run as            */
+  gid_t vtygrp;               /* gid for vty sockets      */
 } zprivs_state;
 
 /* externally exported but not directly accessed functions */
@@ -69,11 +69,9 @@
   [ZCAP_DAC_OVERRIDE] = CAP_DAC_OVERRIDE,
   [ZCAP_READ_SEARCH] = CAP_DAC_READ_SEARCH,
   [ZCAP_SYS_ADMIN] = CAP_SYS_ADMIN,
-  [ZCAP_FOWNER] = ZCAP_FOWNER
+  [ZCAP_FOWNER] = CAP_FOWNER
 };
 
-static cap_value_t cap_setuid_value [] = { CAP_SETUID };
-
 /* convert zebras privileges to system capabilities */
 static cap_value_t *
 zcaps2sys (zebra_capabilities_t *zcaps, int num)
@@ -176,6 +174,12 @@
   struct passwd *pwentry = NULL;
   struct group *grentry = NULL;
 
+  if (!zprivs)
+    {
+      zlog_err ("zprivs_init: called with NULL arg!");
+      exit (1);
+    }
+
   /* NULL privs */
   if (! (zprivs->user || zprivs->group 
          || zprivs->cap_num_p || zprivs->cap_num_i) )
@@ -188,7 +192,31 @@
   if (zprivs->user)
     {
       if ( (pwentry = getpwnam (zprivs->user)) )
-        zprivs_state.zuid = pwentry->pw_uid;
+        {
+          zprivs_state.zuid = pwentry->pw_uid;
+        }
+      else
+        {
+          zlog_err ("privs_init: could not lookup supplied user");
+          exit (1);
+        }
+    }
+
+  grentry = NULL;
+
+  if (zprivs->vty_group)
+    /* Add the vty_group to the supplementary groups so it can be chowned to */
+    {
+      if ( (grentry = getgrnam (zprivs->vty_group)) )
+        {
+          zprivs_state.vtygrp = grentry->gr_gid;
+          if ( setgroups (1, &zprivs_state.vtygrp) )
+            {
+              zlog_err ("privs_init: could not setgroups, %s",
+                         strerror (errno) );
+              exit (1);
+            }       
+        }
       else
         {
           zlog_err ("privs_init: could not lookup supplied user");
@@ -198,18 +226,20 @@
   
   if (zprivs->group)
     {
-      if ( (grentry = getgrnam (zprivs->user)) )
-        zprivs_state.zgid = grentry->gr_gid;
+      if ( (grentry = getgrnam (zprivs->group)) )
+        {
+          zprivs_state.zgid = grentry->gr_gid;
+        }
       else
         {
           zlog_err ("privs_init: could not lookup supplied user");
           exit (1);
         }
-      
       /* change group now, forever. uid we do later */
       if ( setregid (zprivs_state.zgid, zprivs_state.zgid) )
         {
-          zlog_err ("privs_init: could not setregid");
+          zlog_err ("zprivs_init: could not setregid, %s",
+                    strerror (errno) );
           exit (1);
         }
     }
@@ -238,6 +268,17 @@
       zlog_err ("privs_init: failed to cap_init, %s", strerror (errno) );
       exit (1);
     }
+
+  /* we have caps, we have no need to ever change back the original user */
+  if (zprivs_state.zuid)
+    {
+      if ( setreuid (zprivs_state.zuid, zprivs_state.zuid) )
+        {
+          zlog_err ("zprivs_init (cap): could not setreuid, %s", 
+                     strerror (errno) );
+          exit (1);
+        }
+    }
   
   if ( cap_clear (zprivs_state.caps) )
     {
@@ -251,12 +292,6 @@
   cap_set_flag(zprivs_state.caps, CAP_EFFECTIVE, 
                zprivs_state.sys_num_p, zprivs_state.syscaps_p, CAP_SET);
 
-  /* still need CAP_SETUID for the moment */
-  cap_set_flag(zprivs_state.caps, CAP_PERMITTED,
-               1, cap_setuid_value, CAP_SET);
-  cap_set_flag(zprivs_state.caps, CAP_EFFECTIVE,
-  				1, cap_setuid_value, CAP_SET);
-
   /* set inheritable caps, if any */
   if (zprivs_state.sys_num_i)
     {
@@ -264,8 +299,8 @@
                    zprivs_state.sys_num_i, zprivs_state.syscaps_i, CAP_SET);
     }
   
-  /* apply caps. CAP_EFFECTIVE is clear bar cap_setuid_value. 
-   * we'll raise the caps as and when, and only when, they are needed.
+  /* apply caps. CAP_EFFECTIVE is cleared. we'll raise the caps as 
+   * and when, and only when, they are needed.
    */
   if ( cap_set_proc (zprivs_state.caps) ) 
     {
@@ -273,28 +308,7 @@
       exit (1);
     }
   
-  /* we have caps, we have no need to ever change back the original user */
-  if (zprivs_state.zuid)
-    {
-      if ( setreuid (zprivs_state.zuid, zprivs_state.zuid) )
-        {
-          zlog_err ("privs_init (cap): could not setreuid, %s", strerror (errno) );
-          exit (1);
-        }
-    }
-
-  /* No more need for cap_setuid_value */
-  cap_set_flag(zprivs_state.caps, CAP_PERMITTED,
-               1, cap_setuid_value, CAP_CLEAR);
-  cap_set_flag(zprivs_state.caps, CAP_EFFECTIVE,
-  				1, cap_setuid_value, CAP_CLEAR);
-  if ( cap_set_proc (zprivs_state.caps) ) 
-    {
-      zlog_err ("privs_init: cap_set_proc failed to clear cap_setuid, %s",
-                strerror (errno) );
-      exit (1);
-    }
-
+  /* set methods for the caller to use */
   zprivs->change = zprivs_change_caps;
   zprivs->current_state = zprivs_state_caps;
 
@@ -354,3 +368,18 @@
 #endif /* HAVE_LCAPS */
   return;
 }
+
+void
+zprivs_get_ids(struct zprivs_ids_t *ids)
+{
+
+   ids->uid_priv = getuid();
+   (zprivs_state.zuid) ? (ids->uid_normal = zprivs_state.zuid)
+                     : (ids->uid_normal = -1);
+   (zprivs_state.zgid) ? (ids->gid_normal = zprivs_state.zgid)
+                     : (ids->gid_normal = -1);
+   (zprivs_state.vtygrp) ? (ids->gid_vty = zprivs_state.vtygrp)
+                       : (ids->gid_vty = -1);
+   
+   return;
+}
diff --git a/lib/privs.h b/lib/privs.h
index 3cdd20d..65c9f35 100644
--- a/lib/privs.h
+++ b/lib/privs.h
@@ -63,7 +63,7 @@
   int cap_num_i;                    
   char *user;                         /* user and group to run as */
   char *group;
-
+  char *vty_group;                    /* group to chown vty socket to */
   /* methods */
   int 
     (*change) (zebra_privs_ops_t);    /* change privileges, 0 on success */
@@ -71,9 +71,21 @@
     (*current_state) (void);          /* current privilege state */
 };
 
+struct zprivs_ids_t
+{
+  /* -1 is undefined */
+  uid_t uid_priv;                     /* privileged uid */
+  uid_t uid_normal;                   /* normal uid */
+  gid_t gid_priv;                     /* privileged uid */
+  gid_t gid_normal;                   /* normal uid */
+  gid_t gid_vty;                      /* vty gid */
+};
+
   /* initialise zebra privileges */
 void zprivs_init (struct zebra_privs_t *zprivs);
   /* drop all and terminate privileges */ 
 void zprivs_terminate (void);
+  /* query for runtime uid's and gid's, eg vty needs this */
+void zprivs_get_ids(struct zprivs_ids_t *);
 
 #endif /* _ZEBRA_PRIVS_H */
diff --git a/lib/zebra.h b/lib/zebra.h
index 15608db..3d71ad8 100644
--- a/lib/zebra.h
+++ b/lib/zebra.h
@@ -72,10 +72,6 @@
 #ifdef HAVE_RUSAGE
 #include <sys/resource.h>
 #endif /* HAVE_RUSAGE */
-#ifdef HAVE_LCAPS
-#include <sys/capability.h>
-#include <sys/prctl.h>
-#endif /* HAVE_LCAPS */
 
 /* machine dependent includes */
 #ifdef SUNOS_5
@@ -96,6 +92,11 @@
 #include <stdarg.h>
 #include <assert.h>
 
+#ifdef HAVE_LCAPS
+#include <sys/capability.h>
+#include <sys/prctl.h>
+#endif /* HAVE_LCAPS */
+
 /* network include group */
 
 #include <sys/socket.h>