Merge remote-tracking branch 'origin/master' into mq-parallel-import

Version 2.0.7 (2019-10-11)

  o BGP: Accumulated IGP metric (RFC 7311)

  o Important filter reconfiguration bugfix

  o Several other bugfixes

Version 2.0.6 (2019-09-10)

  o RAdv: Solicited unicast RAs

  o BGP: Optional Adj-RIB-Out

  o BGP: Extended optional parameters length

  o Filter: Sets and set expressions in path masks

  o Several important bugfixes

Version 2.0.5 (2019-08-01)

  o OSPF Graceful restart (RFC 3623, RFC 5187)

  o BGP: Dynamic BGP

variable number of options, they are grouped using the <cf/{ }/ brackets. Each

option is terminated by a <cf/;/. Configuration is case sensitive. There are two

ways how to name symbols (like protocol names, filter names, constants etc.).

You can either use a simple string starting with a letter followed by any

combination of letters and numbers (e.g. <cf/R123/, <cf/myfilter/, <cf/bgp5/) or

you can enclose the name into apostrophes (<cf/'/) and than you can use any

combination of numbers, letters. hyphens, dots and colons (e.g.

<cf/'1:strange-name'/, <cf/'-NAME-'/, <cf/'cool::name'/).

You can either use a simple string starting with a letter (or underscore)

followed by any combination of letters, numbers and underscores (e.g. <cf/R123/,

<cf/my_filter/, <cf/bgp5/) or you can enclose the name into apostrophes (<cf/'/)

and than you can use any combination of numbers, letters, underscores, hyphens,

dots and colons (e.g.  <cf/'1:strange-name'/, <cf/'-NAME-'/, <cf/'cool::name'/).

<p>Here is an example of a simple config file. It enables synchronization of

routing tables with OS kernel, learns network interfaces and runs RIP on all

	<tag><label id="opt-attribute">attribute <m/type/ <m/name/</tag>

	Declare a custom route attribute. You can set and get it in filters like

	any other route atribute. This feature is intended for marking routes

	any other route attribute. This feature is intended for marking routes

	in import filters for export filtering purposes instead of locally

	assigned BGP communities which have to be deleted in export filters.

	on all interfaces that have address from 192.168.0.0/16, but not from

	192.168.1.0/24.

	<cf>interface -192.168.1.0/24, 192.168.0.0/16;</cf> - start the protocol

	on all interfaces that have address from 192.168.0.0/16, but not from

	192.168.1.0/24.

	<cf>interface "eth*" 192.168.1.0/24;</cf> - start the protocol on all

	ethernet interfaces that have address from 192.168.1.0/24.

<label id="data-types">

<p>Each variable and each value has certain type. Booleans, integers and enums

are incompatible with each other (that is to prevent you from shooting in the

foot).

are incompatible with each other (that is to prevent you from shooting oneself

in the foot).

<descrip>

	<tag><label id="type-bool">bool</tag>

	This type can hold a single IP address. The IPv4 addresses are stored as

	IPv4-Mapped IPv6 addresses so one data type for both of them is used.

	Whether the address is IPv4 or not may be checked by <cf>.is_ip4</cf>

	which returns <cf/bool/. IP addresses are written in the standard

	which returns a <cf/bool/. IP addresses are written in the standard

	notation (<cf/10.20.30.40/ or <cf/fec0:3:4::1/). You can apply special

	operator <cf>.mask(<M>num</M>)</cf> on values of type ip. It masks out

	all but first <cf><M>num</M></cf> bits from the IP address. So

	but <tt>bgp_path &tilde; [= * 4 5 * =]</tt> is false. BGP mask

	expressions can also contain integer expressions enclosed in parenthesis

	and integer variables, for example <tt>[= * 4 (1+2) a =]</tt>. You can

        also use ranges, for example <tt>[= * 3..5 2 100..200 * =]</tt>.

	also use ranges (e.g. <tt>[= * 3..5 2 100..200 * =]</tt>) and sets

	(e.g. <tt>[= 1 2 [3, 5, 7] * =]</tt>).

	<tag><label id="type-clist">clist</tag>

	Clist is similar to a set, except that unlike other sets, it can be

	<cf/!&tilde;/ membership operators) can be used to modify or test

	eclists, with ECs instead of pairs as arguments.

	<tag><label id="type-lclist">lclist/</tag>

	<tag><label id="type-lclist">lclist</tag>

	Lclist is a data type used for BGP large community lists. Like eclists,

	lclists are very similar to clists, but they are sets of LCs instead of

	pairs. The same operations (like <cf/add/, <cf/delete/ or <cf/&tilde;/

<p>There is one operator related to ROA infrastructure - <cf/roa_check()/. It

examines a ROA table and does <rfc id="6483"> route origin validation for a

given network prefix. The basic usage is <cf>roa_check(<m/table/)</cf>, which

checks current route (which should be from BGP to have AS_PATH argument) in the

specified ROA table and returns ROA_UNKNOWN if there is no relevant ROA,

checks the current route (which should be from BGP to have AS_PATH argument) in

the specified ROA table and returns ROA_UNKNOWN if there is no relevant ROA,

ROA_VALID if there is a matching ROA, or ROA_INVALID if there are some relevant

ROAs but none of them match. There is also an extended variant

<cf>roa_check(<m/table/, <m/prefix/, <m/asn/)</cf>, which allows to specify a

<item> <rfc id="6286"> - AS-Wide Unique BGP Identifier

<item> <rfc id="6608"> - Subcodes for BGP Finite State Machine Error

<item> <rfc id="6793"> - BGP Support for 4-Octet AS Numbers

<item> <rfc id="7311"> - Accumulated IGP Metric Attribute for BGP

<item> <rfc id="7313"> - Enhanced Route Refresh Capability for BGP

<item> <rfc id="7606"> - Revised Error Handling for BGP UPDATE Messages

<item> <rfc id="7911"> - Advertisement of Multiple Paths in BGP

	TX direction. When active, all available routes accepted by the export

	filter are advertised to the neighbor. Default: off.

	<tag><label id="bgp-aigp">aigp <m/switch/|originate</tag>

	The BGP protocol does not use a common metric like other routing

	protocols, instead it uses a set of criteria for route selection

	consisting both overall AS path length and a distance to the nearest AS

	boundary router. Assuming that metrics of different autonomous systems

	are incomparable, once a route is propagated from an AS to a next one,

	the distance in the old AS does not matter.

	The AIGP extension (<rfc id="7311">) allows to propagate accumulated

	IGP metric (in the AIGP attribute) through both IBGP and EBGP links,

	computing total distance through multiple autonomous systems (assuming

	they use comparable IGP metric). The total AIGP metric is compared in

	the route selection process just after Local Preference comparison (and

	before AS path length comparison).

	This option controls whether AIGP attribute propagation is allowed on

	the session. Optionally, it can be set to <cf/originate/, which not only

	allows AIGP attribute propagation, but also new AIGP attributes are

	automatically attached to non-BGP routes with valid IGP metric (e.g.

	<cf/ospf_metric1/) as they are exported to the BGP session. Default:

	enabled for IBGP (and intra-confederation EBGP), disabled for regular

	EBGP.

	<tag><label id="bgp-cost">cost <m/number/</tag>

	When BGP <ref id="bgp-gateway" name="gateway mode"> is <cf/recursive/

	(mainly multihop IBGP sessions), then the distance to BGP next hop is

	based on underlying IGP metric. This option specifies the distance to

	BGP next hop for BGP sessions in direct gateway mode (mainly direct

	EBGP sessions).

	<tag><label id="bgp-graceful-restart-c">graceful restart <m/switch/</tag>

	Although BGP graceful restart is configured mainly by protocol-wide

	<ref id="bgp-graceful-restart" name="options">, it is possible to

	presence of which indicates that the route has been aggregated from

	multiple routes by some router on the path from the originator.

<!-- we don't handle aggregators right since they are of a very obscure type

	<tag>bgp_aggregator</tag>

-->

	<tag><label id="rta-bgp-aggregator">void bgp_aggregator [O]</tag>

	This is an optional attribute specifying AS number and IP address of the

	BGP router that created the route by aggregating multiple BGP routes.

	Currently, the attribute is not accessible from filters.

	<tag><label id="rta-bgp-community">clist bgp_community [O]</tag>

	List of community values associated with the route. Each such value is a

	pair (represented as a <cf/pair/ data type inside the filters) of 16-bit

	<tag><label id="rta-bgp-cluster-list">clist bgp_cluster_list [I, O]</tag>

	This attribute contains a list of cluster IDs of route reflectors. Each

	route reflector prepends its cluster ID when reflecting the route.

	<tag><label id="rta-bgp-aigp">void bgp_aigp [O]</tag>

	This attribute contains accumulated IGP metric, which is a total

	distance to the destination through multiple autonomous systems.

	Currently, the attribute is not accessible from filters.

</descrip>

<sect1>Example

filter peer_in_v4 {

	if (roa_check(r4, net, bgp_path.last) = ROA_INVALID) then

	{

		print "Ignore invalid ROA ", net, " for ASN ", bgp_path.last;

		print "Ignore RPKI invalid ", net, " for ASN ", bgp_path.last;

		reject;

	}

	accept;

    NEVER_CONSTANT;

    SYMBOL;

    FID_SAME_BODY()

      if (!(f2->sym->flags & SYM_FLAG_SAME))

	return 0;

    FID_INTERPRET_BODY()

    /* Push the body on stack */

    LINEX(sym->function);

    curline.emask |= FE_RETURN;

struct filter *f_new_where(struct f_inst *where)

{

  struct f_inst acc = {

    .fi_code = FI_DIE,

    .lineno = ifs->lino,

    .size = 1,

    .i_FI_DIE = { .fret = F_ACCEPT, },

  };

  struct f_inst rej = {

    .fi_code = FI_DIE,

    .lineno = ifs->lino,

    .size = 1,

    .i_FI_DIE = { .fret = F_REJECT, },

  };

  struct f_inst i = {

    .fi_code = FI_CONDITION,

    .lineno = ifs->lino,

    .size = 3 + where->size,

    .i_FI_CONDITION = {

      .f1 = where,

      .f2 = &acc,

      .f3 = &rej,

    },

  };

  struct f_inst *cond = f_new_inst(FI_CONDITION, where,

				   f_new_inst(FI_DIE, F_ACCEPT),

				   f_new_inst(FI_DIE, F_REJECT));

  struct filter *f = cfg_allocz(sizeof(struct filter));

  f->root = f_linearize(&i);

  f->root = f_linearize(cond);

  return f;

}

{

  struct f_val val;

  enum filter_return fret = f_eval(expr, tmp_pool, &val);

  if (fret > F_RETURN)

  if (fret <= F_RETURN)

    val_format(&val, buf);

  return fret;

}