ipv6: add ip6_del_rt_reason()

Add RTA_DEL_REASON and enum rt_del_reason to the rtnetlink uAPI, and add ip6_del_rt_reason(), which takes the reason a route is being deleted. It has no skip_notify argument: a caller that records a deletion reason wants the notification that carries it. The reason is unused for now. Subsequent patches propagate it to the deletion path and report it on RTM_DELROUTE.

Yuyang Huang committed 3 months ago

Commit cc17e381 parent f6057f03 files · +35 −0Browse files

Unified · Split

3 files

include/net/ip6_route.h +2 −0
include/uapi/linux/rtnetlink.h +25 −0
net/ipv6/route.c +8 −0

include/net/ip6_route.h+2−0

 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
 		  struct netlink_ext_ack *extack);
 int ip6_ins_rt(struct net *net, struct fib6_info *f6i);
+int ip6_del_rt_reason(struct net *net, struct fib6_info *f6i,
+		      enum rt_del_reason del_reason);
 #if IS_ENABLED(CONFIG_IPV6)
 int ip6_del_rt(struct net *net, struct fib6_info *f6i, bool skip_notify);
 #else

include/uapi/linux/rtnetlink.h+25−0

@@ -399,6 +399,7 @@ enum rtattr_type_t { · 398 unmodified lines
399	RTA_DPORT,	399	RTA_DPORT,
400	RTA_NH_ID,	400	RTA_NH_ID,
401	RTA_FLOWLABEL,	401	RTA_FLOWLABEL,
		402	RTA_DEL_REASON,
402	__RTA_MAX	403	__RTA_MAX
403	};	404	};
404		405
@@ -407,6 +408,30 @@ enum rtattr_type_t { · 2 unmodified lines
407	#define RTM_RTA(r) ((struct rtattr)(((char)(r)) + NLMSG_ALIGN(sizeof(struct rtmsg))))	408	#define RTM_RTA(r) ((struct rtattr)(((char)(r)) + NLMSG_ALIGN(sizeof(struct rtmsg))))
408	#define RTM_PAYLOAD(n) NLMSG_PAYLOAD(n,sizeof(struct rtmsg))	409	#define RTM_PAYLOAD(n) NLMSG_PAYLOAD(n,sizeof(struct rtmsg))
409		410
		411	/* RTA_DEL_REASON: why the kernel deleted the route. u32.
		412	* Emitted only on RTM_DELROUTE notifications, and only when the deletion
		413	* path records a cause. Absence means either an older kernel or a
		414	* deletion path that does not (yet) record its cause - consumers must
		415	* treat "absent" and "unspec" identically. New causes may be appended.
		416	* Currently only IPv6 deletion paths record a cause.
		417	*
		418	* The attribute is notification-only: the kernel rejects it in
		419	* requests, so a notification must not be echoed back verbatim.
		420	*
		421	* The value space is family-agnostic: a value must never be
		422	* reinterpreted per address family. A cause that only one family can
		423	* produce still gets its own value rather than reusing another
		424	* family's.
		425	*/
		426	enum rt_del_reason {
		427	RT_DEL_REASON_UNSPEC, /* cause not recorded */
		428	RT_DEL_REASON_EXPIRED, /* RTF_EXPIRES lifetime ran out (GC) */
		429	RT_DEL_REASON_RA_WITHDRAWN, /* zero-lifetime RA / PIO / RIO */
		430	__RT_DEL_REASON_MAX
		431	};
		432
		433	#define RT_DEL_REASON_MAX (__RT_DEL_REASON_MAX - 1)
		434
410	/* RTM_MULTIPATH --- array of struct rtnexthop.	435	/* RTM_MULTIPATH --- array of struct rtnexthop.
411	*	436	*
412	* "struct rtnexthop" describes all necessary nexthop information,	437	* "struct rtnexthop" describes all necessary nexthop information,

net/ipv6/route.c+8−0

@@ -4004,6 +4004,14 @@ int ip6_del_rt(struct net net, struct fib6_info rt, bool skip_notify) · 4003 unmodified lines
4004	return __ip6_del_rt(rt, &info);	4004	return __ip6_del_rt(rt, &info);
4005	}	4005	}
4006		4006
		4007	int ip6_del_rt_reason(struct net net, struct fib6_info rt,
		4008	enum rt_del_reason del_reason)
		4009	{
		4010	struct nl_info info = { .nl_net = net };
		4011
		4012	return __ip6_del_rt(rt, &info);
		4013	}
		4014
4007	static int __ip6_del_rt_siblings(struct fib6_info rt, struct fib6_config cfg)	4015	static int __ip6_del_rt_siblings(struct fib6_info rt, struct fib6_config cfg)
4008	{	4016	{
4009	struct nl_info *info = &cfg->fc_nlinfo;	4017	struct nl_info *info = &cfg->fc_nlinfo;