KRT: Add kernel metric protocol option (4adcb9df) · Commits · 戴 / Bird

doc/bird.sgml

+14 −1

Original line number	Diff line number	Diff line
		@@ -2388,6 +2388,17 @@ limitations can be overcome using another routing table and the pipe protocol.
		protocol work with. Available only on systems supporting multiple
		routing tables.

		<tag>metric <m/number/</tag> (Linux)
		Use specified value as a kernel metric (priority) for all routes sent to
		the kernel. When multiple routes for the same network are in the kernel
		routing table, the Linux kernel chooses one with lower metric. Also,
		routes with different metrics do not clash with each other, therefore
		using dedicated metric value is a reliable way to avoid overwriting
		routes from other sources (e.g. kernel device routes). Metric 0 has a
		special meaning of undefined metric, in which either OS default is used,
		or per-route metric can be set using <cf/krt_metric/ attribute. Default:
		0 (undefined).

		<tag>graceful restart <m/switch/</tag>
		Participate in graceful restart recovery. If this option is enabled and
		a graceful restart recovery is active, the Kernel protocol will defer
		@@ -2420,9 +2431,11 @@ these attributes:
		route. See /etc/iproute2/rt_protos for common values. On BSD, it is
		based on STATIC and PROTOx flags. The attribute is read-only.

		<tag>int <cf/krt_metric/</tag>
		<tag>int <cf/krt_metric/</tag> (Linux)
		The kernel metric of the route. When multiple same routes are in a
		kernel routing table, the Linux kernel chooses one with lower metric.
		Note that preferred way to set kernel metric is to use protocol option
		<cf/metric/, unless per-route metric values are needed.

		<tag>ip <cf/krt_prefsrc/</tag> (Linux)
		The preferred source address. Used in source address selection for

sysdep/linux/krt-sys.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -88,6 +88,7 @@ static inline struct ifa * kif_get_primary_ip(struct iface *i) { return NULL; }

		struct krt_params {
		u32 table_id; /* Kernel table ID we sync with */
		u32 metric; /* Kernel metric used for all routes */
		};

		struct krt_state {

sysdep/linux/netlink.Y

+4 −5

Original line number	Diff line number	Diff line
		@@ -10,8 +10,8 @@ CF_HDR

		CF_DECLS

		CF_KEYWORDS(KERNEL, TABLE, KRT_PREFSRC, KRT_REALM, KRT_MTU, KRT_WINDOW, KRT_RTT,
		KRT_RTTVAR, KRT_SSTRESH, KRT_CWND, KRT_ADVMSS, KRT_REORDERING,
		CF_KEYWORDS(KERNEL, TABLE, METRIC, KRT_PREFSRC, KRT_REALM, KRT_MTU, KRT_WINDOW,
		KRT_RTT, KRT_RTTVAR, KRT_SSTRESH, KRT_CWND, KRT_ADVMSS, KRT_REORDERING,
		KRT_HOPLIMIT, KRT_INITCWND, KRT_RTO_MIN, KRT_INITRWND, KRT_QUICKACK,
		KRT_LOCK_MTU, KRT_LOCK_WINDOW, KRT_LOCK_RTT, KRT_LOCK_RTTVAR,
		KRT_LOCK_SSTRESH, KRT_LOCK_CWND, KRT_LOCK_ADVMSS, KRT_LOCK_REORDERING,
		@@ -22,9 +22,8 @@ CF_GRAMMAR
		CF_ADDTO(kern_proto, kern_proto kern_sys_item ';')

		kern_sys_item:
		KERNEL TABLE expr {
		THIS_KRT->sys.table_id = $3;
		}
		KERNEL TABLE expr { THIS_KRT->sys.table_id = $3; }
		\| METRIC expr { THIS_KRT->sys.metric = $2; }
		;

		CF_ADDTO(dynamic_attr, KRT_PREFSRC { $$ = f_new_dynamic_attr(EAF_TYPE_IP_ADDRESS, T_IP, EA_KRT_PREFSRC); })

sysdep/linux/netlink.c

+15 −4

Original line number	Diff line number	Diff line
		@@ -880,6 +880,8 @@ nl_send_route(struct krt_proto p, rte e, struct ea_list *eattrs, int op, int d
		eattr *ea;
		net *net = e->net;
		rta *a = e->attrs;
		u32 priority = 0;

		struct {
		struct nlmsghdr h;
		struct rtmsg r;
		@@ -912,13 +914,20 @@ nl_send_route(struct krt_proto p, rte e, struct ea_list *eattrs, int op, int d
		else
		nl_add_attr_u32(&r.h, sizeof(r), RTA_TABLE, krt_table_id(p));

		if (a->source == RTS_DUMMY)
		priority = e->u.krt.metric;
		else if (KRT_CF->sys.metric)
		priority = KRT_CF->sys.metric;
		else if ((op != NL_OP_DELETE) && (ea = ea_find(eattrs, EA_KRT_METRIC)))
		priority = ea->u.data;

		if (priority)
		nl_add_attr_u32(&r.h, sizeof(r), RTA_PRIORITY, priority);

		/* For route delete, we do not specify remaining route attributes */
		if (op == NL_OP_DELETE)
		goto dest;

		if (ea = ea_find(eattrs, EA_KRT_METRIC))
		nl_add_attr_u32(&r.h, sizeof(r), RTA_PRIORITY, ea->u.data);

		if (ea = ea_find(eattrs, EA_KRT_PREFSRC))
		nl_add_attr_ipa(&r.h, sizeof(r), RTA_PREFSRC, (ip_addr )ea->u.ptr->data);

		@@ -1585,19 +1594,21 @@ krt_sys_shutdown(struct krt_proto *p)
		int
		krt_sys_reconfigure(struct krt_proto p UNUSED, struct krt_config n, struct krt_config *o)
		{
		return n->sys.table_id == o->sys.table_id;
		return (n->sys.table_id == o->sys.table_id) && (n->sys.metric == o->sys.metric);
		}

		void
		krt_sys_init_config(struct krt_config *cf)
		{
		cf->sys.table_id = RT_TABLE_MAIN;
		cf->sys.metric = 0;
		}

		void
		krt_sys_copy_config(struct krt_config d, struct krt_config s)
		{
		d->sys.table_id = s->sys.table_id;
		d->sys.metric = s->sys.metric;
		}

		static const char *krt_metrics_names[KRT_METRICS_MAX] = {

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