Check validity of interface definitions.

	Set BIRD's router ID based on an IP address of an interface specified by

	an interface pattern. The option is applicable for IPv4 version only.

	See <ref id="dsc-iface" name="interface"> section for detailed

	description of interface patterns.

	description of interface patterns with extended clauses.

	<tag>listen bgp [address <m/address/] [port <m/port/] [dual]</tag>

	This option allows to specify address and port where BGP protocol should

	given interface-specific options. A set of interfaces specified by one

	interface option is described using an interface pattern. The interface

	pattern consists of a sequence of clauses (separated by commas), each

	clause may contain a mask, a prefix, or both of them. An interface

	matches the clause if its name matches the mask (if specified) and its

	address matches the prefix (if specified). Mask is specified as

	shell-like pattern. For IPv6, the prefix part of a clause is generally

	ignored and interfaces are matched just by their name.

	clause is a mask specified as a shell-like pattern. Interfaces are

	matched by their name.

	An interface matches the pattern if it matches any of its clauses. If

	the clause begins with <cf/-/, matching interfaces are excluded. Patterns

	are parsed left-to-right, thus <cf/interface "eth0", -"eth*", "*";/

	are processed left-to-right, thus <cf/interface "eth0", -"eth*", "*";/

	means eth0 and all non-ethernets.

	Some protocols (namely OSPFv2 and Direct) support extended clauses that

	may contain a mask, a prefix, or both of them. An interface matches such

	clause if its name matches the mask (if specified) and its address

	matches the prefix (if specified). Extended clauses are used when the

	protocol handles multiple addresses on an interface independently.

	An interface option can be used more times with different interface-specific

	options, in that case for given interface the first matching interface

	option is used.

	This option is allowed in Direct, OSPF, RIP and RAdv protocols, but in

	OSPF protocol it is used in <cf/area/ subsection.

	This option is allowed in BFD, Direct, OSPF, RAdv and RIP protocols, but

	in OSPF protocol it is used in the <cf/area/ subsection.

	Default: none.

	<tag>interface <m/pattern [, ...]/</tag>

	By default, the Direct protocol will generate device routes for all the

	interfaces available. If you want to restrict it to some subset of

	interfaces (for example if you're using multiple routing tables for

	policy routing and some of the policy domains don't contain all

	interfaces), just use this clause.

	interfaces or addresses (e.g. if you're using multiple routing tables

	for policy routing and some of the policy domains don't contain all

	interfaces), just use this clause. See <ref id="dsc-iface" name="interface">

	common option for detailed description. The Direct protocol uses

	extended interface clauses.

</descrip>

<p>Direct device routes don't contain any specific attributes.

	<tag>interface <M>pattern</M> [instance <m/num/]</tag>

	Defines that the specified interfaces belong to the area being defined.

	See <ref id="dsc-iface" name="interface"> common option for detailed

	description. In OSPFv3, you can specify instance ID for that interface

	description, so it is possible to have several instances of that

	interface with different options or even in different areas.

	description. In OSPFv2, extended interface clauses are used, because

	OSPFv2 handles each network prefix as a separate virtual interface. In

	OSPFv3, you can specify instance ID for that interface description, so

	it is possible to have several instances of that interface with

	different options or even in different areas.

	<tag>virtual link <M>id</M> [instance <m/num/]</tag>

	Virtual link to router with the router id. Virtual link acts as a

static struct password_item *this_p_item;

static int password_id;

static void

iface_patt_check(void)

{

  struct iface_patt_node *pn;

  WALK_LIST(pn, this_ipatt->ipn_list)

    if (!pn->pattern || pn->pxlen)

      cf_error("Interface name/mask expected, not IP prefix");

}

static inline void

reset_passwords(void)

{

 | iface_patt_list ',' iface_patt_node

 ;

/* For name/mask-only iface patterns */

iface_patt_list_nopx: iface_patt_list { iface_patt_check(); }

iface_patt_init: {

   /* Generic this_ipatt init */

   this_ipatt = cfg_allocz(sizeof(struct iface_patt));

 | '{' bfd_iface_opts '}'

 ;

bfd_iface: bfd_iface_start iface_patt_list bfd_iface_opt_list

bfd_iface: bfd_iface_start iface_patt_list_nopx bfd_iface_opt_list

{ add_tail(&BFD_CFG->patt_list, NODE this_ipatt); };

bfd_multihop: bfd_iface_start bfd_iface_opt_list

 | INSTANCE expr { set_instance_id($2); }

 ;

ospf_iface_patt_list:

   iface_patt_list { if (OSPF_VERSION == 3) iface_patt_check(); } ospf_instance_id

 ; 

ospf_iface_opts:

   /* empty */

 | ospf_iface_opts ospf_iface_item ';'

 ;

ospf_iface:

  ospf_iface_start iface_patt_list ospf_instance_id ospf_iface_opt_list { ospf_iface_finish(); }

  ospf_iface_start ospf_iface_patt_list ospf_iface_opt_list { ospf_iface_finish(); }

 ;

opttext:

 ;

radv_iface:

  radv_iface_start iface_patt_list radv_iface_opt_list radv_iface_finish;

  radv_iface_start iface_patt_list_nopx radv_iface_opt_list radv_iface_finish;

radv_prefix_start: prefix