blob: 04609ba8aaf5896d8764cffe29f175eb5c3ccf9d [file] [log] [blame]
/*
* Copyright (C) 1999 Yasuhiro Ohara
*
* This file is part of GNU Zebra.
*
* GNU Zebra is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* GNU Zebra is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Zebra; see the file COPYING. If not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "ospf6d.h"
#include "ospf6_damp.h"
/* global ospf6d variable */
int ospf6_sock;
list iflist;
list nexthoplist = NULL;
struct sockaddr_in6 allspfrouters6;
struct sockaddr_in6 alldrouters6;
char *recent_reason; /* set by ospf6_lsa_check_recent () */
int proctitle_mode = 0;
char ospf6_daemon_version[] = OSPF6_DAEMON_VERSION;
#define TIMER_SEC_MICRO 1000000
void
ospf6_timeval_sub (const struct timeval *t1, const struct timeval *t2,
struct timeval *result)
{
long usec, movedown = 0;
if (t1->tv_sec < t2->tv_sec ||
(t1->tv_sec == t2->tv_sec && t1->tv_usec < t2->tv_usec))
{
result->tv_sec = 0;
result->tv_usec = 0;
return;
}
if (t1->tv_usec < t2->tv_usec)
{
usec = t1->tv_usec + TIMER_SEC_MICRO;
movedown++;
}
else
usec = t1->tv_usec;
result->tv_usec = usec - t2->tv_usec;
result->tv_sec = t1->tv_sec - t2->tv_sec - movedown;
}
void
ospf6_timeval_div (const struct timeval *t1, u_int by,
struct timeval *result)
{
long movedown;
if (by == 0)
{
result->tv_sec = 0;
result->tv_usec = 0;
return;
}
movedown = t1->tv_sec % by;
result->tv_sec = t1->tv_sec / by;
result->tv_usec = (t1->tv_usec + movedown * TIMER_SEC_MICRO) / by;
}
void
ospf6_timeval_decode (const struct timeval *t, long *dayp, long *hourp,
long *minp, long *secp, long *msecp, long *usecp)
{
long day, hour, min, sec, msec, usec, left;
left = t->tv_sec;
day = left / 86400; left -= day * 86400;
hour = left / 3600; left -= hour * 3600;
min = left / 60; left -= min * 60;
sec = left;
left = t->tv_usec;
msec = left / 1000; left -= msec * 1000;
usec = left;
if (dayp) *dayp = day;
if (hourp) *hourp = hour;
if (minp) *minp = min;
if (secp) *secp = sec;
if (msecp) *msecp = msec;
if (usecp) *usecp = usec;
}
void
ospf6_timeval_string (struct timeval *tv, char *buf, int size)
{
char days[16], hours[16], mins[16], secs[16], msecs[16], usecs[16];
long day, hour, min, sec, msec, usec;
ospf6_timeval_decode (tv, &day, &hour, &min, &sec, &msec, &usec);
snprintf (days, sizeof (days), "%ld days ", day);
snprintf (hours, sizeof (hours), "%ld hours ", hour);
snprintf (mins, sizeof (mins), "%ld mins ", min);
snprintf (secs, sizeof (secs), "%ld secs ", sec);
snprintf (msecs, sizeof (msecs), "%ld msecs ", msec);
snprintf (usecs, sizeof (usecs), "%ld usecs ", usec);
snprintf (buf, size, "%s%s%s%s%s%s",
(day ? days : ""), (hour ? hours : ""),
(min ? mins : ""), (sec ? secs : ""),
(msec ? msecs : ""), (usec ? usecs : ""));
}
void
ospf6_timeval_string_summary (struct timeval *tv, char *buf, int size)
{
char days[16], hours[16], mins[16], secs[16], msecs[16], usecs[16];
long day, hour, min, sec, msec, usec;
ospf6_timeval_decode (tv, &day, &hour, &min, &sec, &msec, &usec);
snprintf (days, sizeof (days), "%02ldd", day);
snprintf (hours, sizeof (hours), "%ldh", hour);
snprintf (mins, sizeof (mins), "%ldm", min);
snprintf (secs, sizeof (secs), "%lds", sec);
snprintf (msecs, sizeof (msecs), "%ldms", msec);
snprintf (usecs, sizeof (usecs), "%ldus", usec);
snprintf (buf, size, "%s%02ld:%02ld:%02ld",
(day ? days : ""), hour, min, sec);
}
/* foreach function */
void
ospf6_count_state (void *arg, int val, void *obj)
{
int *count = (int *) arg;
u_char state = val;
struct ospf6_neighbor *nei = (struct ospf6_neighbor *) obj;
if (nei->state == state)
(*count)++;
}
/* VTY commands. */
DEFUN (reload,
reload_cmd,
"reload",
"Reloads\n")
{
extern void _reload ();
_reload ();
return CMD_SUCCESS;
}
DEFUN (garbage_collection,
garbage_collection_cmd,
"ipv6 ospf6 garbage collect",
IPV6_STR
OSPF6_STR
"garbage collection by hand\n"
"Remove Maxages if possible and recalculate routes\n")
{
ospf6_maxage_remover ();
#if 0
ospf6_route_calculation_schedule ();
#endif
return CMD_SUCCESS;
}
/* Show version. */
DEFUN (show_version_ospf6,
show_version_ospf6_cmd,
"show version ospf6",
SHOW_STR
"Displays ospf6d version\n")
{
vty_out (vty, "Zebra OSPF6d Version: %s%s",
ospf6_daemon_version, VTY_NEWLINE);
return CMD_SUCCESS;
}
/* start ospf6 */
DEFUN (router_ospf6,
router_ospf6_cmd,
"router ospf6",
OSPF6_ROUTER_STR
OSPF6_STR)
{
if (ospf6 == NULL)
ospf6_start ();
/* set current ospf point. */
vty->node = OSPF6_NODE;
vty->index = ospf6;
return CMD_SUCCESS;
}
/* stop ospf6 */
DEFUN (no_router_ospf6,
no_router_ospf6_cmd,
"no router ospf6",
NO_STR
OSPF6_ROUTER_STR)
{
if (!ospf6)
vty_out (vty, "OSPFv3 is not running%s", VTY_NEWLINE);
else
ospf6_stop ();
/* return to config node . */
vty->node = CONFIG_NODE;
vty->index = NULL;
return CMD_SUCCESS;
}
/* show top level structures */
DEFUN (show_ipv6_ospf6,
show_ipv6_ospf6_cmd,
"show ipv6 ospf6",
SHOW_STR
IP6_STR
OSPF6_STR)
{
OSPF6_CMD_CHECK_RUNNING ();
ospf6_show (vty);
return CMD_SUCCESS;
}
DEFUN (show_ipv6_ospf6_nexthoplist,
show_ipv6_ospf6_nexthoplist_cmd,
"show ipv6 ospf6 nexthop-list",
SHOW_STR
IP6_STR
OSPF6_STR
"List of nexthop\n")
{
#if 0
listnode i;
struct ospf6_nexthop *nh;
char buf[128];
for (i = listhead (nexthoplist); i; nextnode (i))
{
nh = (struct ospf6_nexthop *) getdata (i);
nexthop_str (nh, buf, sizeof (buf));
vty_out (vty, "%s%s", buf,
VTY_NEWLINE);
}
#endif
return CMD_SUCCESS;
}
DEFUN (show_ipv6_ospf6_statistics,
show_ipv6_ospf6_statistics_cmd,
"show ipv6 ospf6 statistics",
SHOW_STR
IP6_STR
OSPF6_STR
"Statistics\n")
{
OSPF6_CMD_CHECK_RUNNING ();
ospf6_statistics_show (vty, ospf6);
return CMD_SUCCESS;
}
/* change Router_ID commands. */
DEFUN (ospf6_router_id,
ospf6_router_id_cmd,
"router-id ROUTER_ID",
"Configure ospf Router-ID.\n"
V4NOTATION_STR)
{
int ret;
u_int32_t router_id;
ret = inet_pton (AF_INET, argv[0], &router_id);
if (!ret)
{
vty_out (vty, "malformed ospf router identifier%s", VTY_NEWLINE);
vty_out (vty, "%s", VTY_NEWLINE);
return CMD_WARNING;
}
if (IS_OSPF6_DUMP_CONFIG)
zlog_info ("CONFIG: router-id %s", argv[0]);
ospf6->router_id = router_id;
return CMD_SUCCESS;
}
int
ospf6_interface_bind_area (struct vty *vty,
char *if_name, char *area_name,
char *plist_name, int passive)
{
struct interface *ifp;
struct ospf6_interface *o6i;
struct ospf6_area *o6a;
u_int32_t area_id;
/* find/create ospf6 interface */
ifp = if_get_by_name (if_name);
o6i = (struct ospf6_interface *) ifp->info;
if (! o6i)
o6i = ospf6_interface_create (ifp);
/* parse Area-ID */
if (inet_pton (AF_INET, area_name, &area_id) != 1)
{
vty_out (vty, "Invalid Area-ID: %s%s", area_name, VTY_NEWLINE);
return CMD_ERR_AMBIGUOUS;
}
/* find/create ospf6 area */
o6a = ospf6_area_lookup (area_id, ospf6);
if (!o6a)
{
o6a = ospf6_area_create (area_id);
o6a->ospf6 = ospf6;
listnode_add (ospf6->area_list, o6a);
}
if (o6i->area)
{
if (o6i->area != o6a)
{
vty_out (vty, "Aready attached to area %s%s",
o6i->area->str, VTY_NEWLINE);
return CMD_ERR_NOTHING_TODO;
}
}
else
{
listnode_add (o6a->if_list, o6i);
o6i->area = o6a;
}
/* prefix-list name */
if (plist_name)
{
if (o6i->plist_name)
XFREE (MTYPE_PREFIX_LIST_STR, o6i->plist_name);
o6i->plist_name = XSTRDUP (MTYPE_PREFIX_LIST_STR, plist_name);
}
else
{
if (o6i->plist_name)
XFREE (MTYPE_PREFIX_LIST_STR, o6i->plist_name);
o6i->plist_name = NULL;
}
if (passive)
{
listnode node;
struct ospf6_neighbor *o6n;
SET_FLAG (o6i->flag, OSPF6_INTERFACE_FLAG_PASSIVE);
if (o6i->thread_send_hello)
{
thread_cancel (o6i->thread_send_hello);
o6i->thread_send_hello = (struct thread *) NULL;
}
for (node = listhead (o6i->neighbor_list); node; nextnode (node))
{
o6n = getdata (node);
if (o6n->inactivity_timer)
thread_cancel (o6n->inactivity_timer);
thread_execute (master, inactivity_timer, o6n, 0);
}
}
else
{
UNSET_FLAG (o6i->flag, OSPF6_INTERFACE_FLAG_PASSIVE);
if (o6i->thread_send_hello == NULL)
thread_add_event (master, ospf6_send_hello, o6i, 0);
}
/* enable I/F if it's not enabled still */
if (! ospf6_interface_is_enabled (o6i->interface->ifindex))
thread_add_event (master, interface_up, o6i, 0);
else
CALL_FOREACH_LSA_HOOK (hook_interface, hook_change, o6i);
CALL_CHANGE_HOOK (&interface_hook, o6i);
return CMD_SUCCESS;
}
DEFUN (ospf6_interface_area_plist,
ospf6_interface_area_plist_cmd,
"interface IFNAME area A.B.C.D prefix-list WORD",
"Enable routing on an IPv6 interface\n"
IFNAME_STR
"Set the OSPF6 area ID\n"
"OSPF6 area ID in IPv4 address notation\n"
OSPF6_PREFIX_LIST_STR
"IPv6 prefix-list name\n"
)
{
if (IS_OSPF6_DUMP_CONFIG)
zlog_info ("CONFIG: interface %s area %s prefix-list %s",
argv[0], argv[1], argv[2]);
return ospf6_interface_bind_area (vty, argv[0], argv[1], argv[2], 0);
}
DEFUN (ospf6_interface_area_plist_passive,
ospf6_interface_area_plist_passive_cmd,
"interface IFNAME area A.B.C.D prefix-list WORD passive",
"Enable routing on an IPv6 interface\n"
IFNAME_STR
"Set the OSPF6 area ID\n"
"OSPF6 area ID in IPv4 address notation\n"
OSPF6_PREFIX_LIST_STR
"IPv6 prefix-list name\n"
"IPv6 prefix-list name\n"
OSPF6_PASSIVE_STR
)
{
if (IS_OSPF6_DUMP_CONFIG)
zlog_info ("CONFIG: interface %s area %s prefix-list %s passive",
argv[0], argv[1], argv[2]);
return ospf6_interface_bind_area (vty, argv[0], argv[1], argv[2], 1);
}
DEFUN (ospf6_interface_area,
ospf6_interface_area_cmd,
"interface IFNAME area A.B.C.D",
"Enable routing on an IPv6 interface\n"
IFNAME_STR
"Set the OSPF6 area ID\n"
"OSPF6 area ID in IPv4 address notation\n"
)
{
struct interface *ifp;
struct ospf6_interface *o6i;
int passive;
char *plist_name;
if (IS_OSPF6_DUMP_CONFIG)
zlog_info ("CONFIG: interface %s area %s",
argv[0], argv[1]);
ifp = if_get_by_name (argv[0]);
o6i = (struct ospf6_interface *) ifp->info;
if (o6i)
{
passive = CHECK_FLAG (o6i->flag, OSPF6_INTERFACE_FLAG_PASSIVE);
plist_name = o6i->plist_name;
}
else
{
passive = 0;
plist_name = NULL;
}
return ospf6_interface_bind_area (vty, argv[0], argv[1],
plist_name, passive);
}
DEFUN (ospf6_interface_area_passive,
ospf6_interface_area_passive_cmd,
"interface IFNAME area A.B.C.D passive",
"Enable routing on an IPv6 interface\n"
IFNAME_STR
"Set the OSPF6 area ID\n"
"OSPF6 area ID in IPv4 address notation\n"
OSPF6_PASSIVE_STR
)
{
if (IS_OSPF6_DUMP_CONFIG)
zlog_info ("CONFIG: interface %s area %s passive",
argv[0], argv[1]);
return ospf6_interface_bind_area (vty, argv[0], argv[1], NULL, 1);
}
DEFUN (no_ospf6_interface_area,
no_ospf6_interface_area_cmd,
"no interface IFNAME area A.B.C.D",
NO_STR
"Disable routing on an IPv6 interface\n"
IFNAME_STR)
{
struct interface *ifp;
struct ospf6_interface *o6i;
struct ospf6 *o6;
u_int32_t area_id;
o6 = (struct ospf6 *) vty->index;
ifp = if_lookup_by_name (argv[0]);
if (!ifp)
return CMD_ERR_NO_MATCH;
o6i = (struct ospf6_interface *) ifp->info;
if (!o6i)
return CMD_SUCCESS;
/* parse Area-ID */
if (inet_pton (AF_INET, argv[1], &area_id) != 1)
{
vty_out (vty, "Invalid Area-ID: %s%s", argv[1], VTY_NEWLINE);
return CMD_ERR_AMBIGUOUS;
}
if (o6i->area->area_id != area_id)
{
vty_out (vty, "Wrong Area-ID: %s aready attached to area %s%s",
o6i->interface->name, o6i->area->str, VTY_NEWLINE);
return CMD_ERR_NOTHING_TODO;
}
if (o6i->area)
thread_execute (master, interface_down, o6i, 0);
listnode_delete (o6i->area->if_list, o6i);
o6i->area = (struct ospf6_area *) NULL;
return CMD_SUCCESS;
}
DEFUN (ospf6_area_range,
ospf6_area_range_cmd,
"area A.B.C.D range X:X::X:X/M",
"OSPFv3 area parameters\n"
"OSPFv3 area ID in IPv4 address format\n"
"Summarize routes matching address/mask (border routers only)\n"
"IPv6 address range\n")
{
struct ospf6 *o6;
struct ospf6_area *o6a;
u_int32_t area_id;
int ret;
o6 = (struct ospf6 *) vty->index;
inet_pton (AF_INET, argv[0], &area_id);
o6a = ospf6_area_lookup (area_id, o6);
if (! o6a)
{
vty_out (vty, "No such area%s", VTY_NEWLINE);
return CMD_ERR_NO_MATCH;
}
ret = str2prefix_ipv6 (argv[1], &o6a->area_range);
if (ret <= 0)
{
vty_out (vty, "Malformed IPv6 address%s", VTY_NEWLINE);
return CMD_WARNING;
}
return CMD_SUCCESS;
}
DEFUN (ospf6_passive_interface,
ospf6_passive_interface_cmd,
"passive-interface IFNAME",
OSPF6_PASSIVE_STR
IFNAME_STR)
{
struct interface *ifp;
struct ospf6_interface *o6i;
ifp = if_get_by_name (argv[0]);
if (ifp->info)
o6i = (struct ospf6_interface *) ifp->info;
else
o6i = ospf6_interface_create (ifp);
SET_FLAG (o6i->flag, OSPF6_INTERFACE_FLAG_PASSIVE);
if (o6i->thread_send_hello)
{
thread_cancel (o6i->thread_send_hello);
o6i->thread_send_hello = (struct thread *) NULL;
}
return CMD_SUCCESS;
}
DEFUN (no_ospf6_passive_interface,
no_ospf6_passive_interface_cmd,
"no passive-interface IFNAME",
NO_STR
OSPF6_PASSIVE_STR
IFNAME_STR)
{
struct interface *ifp;
struct ospf6_interface *o6i;
ifp = if_lookup_by_name (argv[0]);
if (! ifp)
return CMD_ERR_NO_MATCH;
o6i = (struct ospf6_interface *) ifp->info;
UNSET_FLAG (o6i->flag, OSPF6_INTERFACE_FLAG_PASSIVE);
if (o6i->thread_send_hello == NULL)
thread_add_event (master, ospf6_send_hello, o6i, 0);
return CMD_SUCCESS;
}
#ifdef HAVE_SETPROCTITLE
extern int _argc;
extern char **_argv;
DEFUN (set_proctitle,
set_proctitle_cmd,
"set proctitle (version|normal|none)",
"Set command\n"
"Process title\n"
"Version information\n"
"Normal command-line options\n"
"Just program name\n")
{
int i;
char buf[64], tmp[64];
if (strncmp (argv[0], "v", 1) == 0)
{
proctitle_mode = 1;
setproctitle ("%s Zebra: %s", OSPF6_DAEMON_VERSION, ZEBRA_VERSION);
}
else if (strncmp (argv[0], "nor", 3) == 0)
{
proctitle_mode = 0;
memset (tmp, 0, sizeof (tmp));
memset (buf, 0, sizeof (buf));
for (i = 0; i < _argc; i++)
{
snprintf (buf, sizeof (buf), "%s%s ", tmp, _argv[i]);
memcpy (&tmp, &buf, sizeof (tmp));
}
setproctitle (buf);
}
else if (strncmp (argv[0], "non", 3) == 0)
{
proctitle_mode = -1;
setproctitle (NULL);
}
else
return CMD_ERR_NO_MATCH;
return CMD_SUCCESS;
}
#endif /* HAVE_SETPROCTITLE */
/* OSPF configuration write function. */
int
ospf6_config_write (struct vty *vty)
{
listnode j, k;
char buf[64];
struct ospf6_area *area;
struct ospf6_interface *o6i;
if (proctitle_mode == 1)
vty_out (vty, "set proctitle version%s", VTY_NEWLINE);
else if (proctitle_mode == -1)
vty_out (vty, "set proctitle none%s", VTY_NEWLINE);
vty_out (vty, "!%s", VTY_NEWLINE);
if (! ospf6)
return 0;
/* OSPFv6 configuration. */
if (!ospf6)
return CMD_SUCCESS;
inet_ntop (AF_INET, &ospf6->router_id, buf, sizeof (buf));
vty_out (vty, "router ospf6%s", VTY_NEWLINE);
vty_out (vty, " router-id %s%s", buf, VTY_NEWLINE);
ospf6_redistribute_config_write (vty);
ospf6_damp_config_write (vty);
for (j = listhead (ospf6->area_list); j; nextnode (j))
{
area = (struct ospf6_area *)getdata (j);
for (k = listhead (area->if_list); k; nextnode (k))
{
o6i = (struct ospf6_interface *) getdata (k);
vty_out (vty, " interface %s area %s%s",
o6i->interface->name, area->str, VTY_NEWLINE);
}
}
vty_out (vty, "!%s", VTY_NEWLINE);
return 0;
}
/* OSPF6 node structure. */
struct cmd_node ospf6_node =
{
OSPF6_NODE,
"%s(config-ospf6)# ",
vtysh: 1
};
/* Install ospf related commands. */
void
ospf6_init ()
{
/* Install ospf6 top node. */
install_node (&ospf6_node, ospf6_config_write);
install_element (VIEW_NODE, &show_ipv6_ospf6_cmd);
install_element (VIEW_NODE, &show_version_ospf6_cmd);
install_element (ENABLE_NODE, &show_ipv6_ospf6_cmd);
install_element (ENABLE_NODE, &show_version_ospf6_cmd);
install_element (ENABLE_NODE, &reload_cmd);
install_element (CONFIG_NODE, &router_ospf6_cmd);
install_element (CONFIG_NODE, &interface_cmd);
install_element (CONFIG_NODE, &no_interface_cmd);
#ifdef OSPF6_STATISTICS
install_element (VIEW_NODE, &show_ipv6_ospf6_statistics_cmd);
install_element (ENABLE_NODE, &show_ipv6_ospf6_statistics_cmd);
#endif /* OSPF6_STATISTICS */
#ifdef OSPF6_GARBAGE_COLLECT
install_element (ENABLE_NODE, &garbage_collection_cmd);
#endif /* OSPF6_GARBAGE_COLLECT */
#ifdef HAVE_SETPROCTITLE
install_element (CONFIG_NODE, &set_proctitle_cmd);
#endif /* HAVE_SETPROCTITLE */
install_default (OSPF6_NODE);
install_element (OSPF6_NODE, &ospf6_router_id_cmd);
install_element (OSPF6_NODE, &ospf6_interface_area_cmd);
install_element (OSPF6_NODE, &ospf6_interface_area_passive_cmd);
install_element (OSPF6_NODE, &ospf6_interface_area_plist_cmd);
install_element (OSPF6_NODE, &ospf6_interface_area_plist_passive_cmd);
install_element (OSPF6_NODE, &no_ospf6_interface_area_cmd);
install_element (OSPF6_NODE, &ospf6_passive_interface_cmd);
install_element (OSPF6_NODE, &no_ospf6_passive_interface_cmd);
install_element (OSPF6_NODE, &ospf6_area_range_cmd);
/* Make empty list of top list. */
if_init ();
/* Install access list */
access_list_init ();
/* Install prefix list */
prefix_list_init ();
ospf6_dump_init ();
#ifdef HAVE_OSPF6_DAMP
ospf6_damp_init ();
#endif /*HAVE_OSPF6_DAMP*/
ospf6_hook_init ();
ospf6_lsa_init ();
ospf6_top_init ();
ospf6_area_init ();
ospf6_interface_init ();
ospf6_neighbor_init ();
ospf6_zebra_init ();
ospf6_routemap_init ();
ospf6_lsdb_init ();
ospf6_spf_init ();
ospf6_intra_init ();
ospf6_abr_init ();
ospf6_asbr_init ();
}
void
ospf6_terminate ()
{
/* stop ospf6 */
ospf6_stop ();
/* log */
zlog (NULL, LOG_INFO, "OSPF6d terminated");
}
void
ospf6_maxage_remover ()
{
#if 0
if (IS_OSPF6_DUMP_LSDB)
zlog_info ("MaxAge Remover");
#endif
ospf6_top_schedule_maxage_remover (NULL, 0, ospf6);
(*ospf6->foreach_area) (ospf6, NULL, 0,
ospf6_area_schedule_maxage_remover);
(*ospf6->foreach_if) (ospf6, NULL, 0,
ospf6_interface_schedule_maxage_remover);
}
void *
ospf6_lsa_get_scope (u_int16_t type, struct ospf6_interface *o6i)
{
if (OSPF6_LSA_IS_SCOPE_LINKLOCAL (ntohs (type)))
return o6i;
else if (OSPF6_LSA_IS_SCOPE_AREA (ntohs (type)))
return o6i->area;
else if (OSPF6_LSA_IS_SCOPE_AS (ntohs (type)))
return o6i->area->ospf6;
else
return NULL;
}