Commit ba413803 authored by Ido Schimmel's avatar Ido Schimmel Committed by Paolo Abeni
Browse files

ipv6: Add flow label to route get requests 



The default IPv6 multipath hash policy takes the flow label into account
when calculating a multipath hash and previous patches added a flow
label selector to IPv6 FIB rules.

Allow user space to specify a flow label in route get requests by adding
a new netlink attribute and using its value to populate the "flowlabel"
field in the IPv6 flow info structure prior to a route lookup.

Deny the attribute in RTM_{NEW,DEL}ROUTE requests by checking for it in
rtm_to_fib6_config() and returning an error if present.

A subsequent patch will use this capability to test the new flow label
selector in IPv6 FIB rules.

Reviewed-by: default avatarPetr Machata <petrm@nvidia.com>
Signed-off-by: default avatarIdo Schimmel <idosch@nvidia.com>
Reviewed-by: default avatarGuillaume Nault <gnault@redhat.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent c72004aa

include/uapi/linux/rtnetlink.h

+1 −0
Original line number Diff line number Diff line
@@ -393,6 +393,7 @@ enum rtattr_type_t { 
	RTA_SPORT,

	RTA_DPORT,

	RTA_NH_ID,

	RTA_FLOWLABEL,

	__RTA_MAX

};

net/ipv6/route.c

+19 −1
Original line number Diff line number Diff line
@@ -5005,6 +5005,7 @@ static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = { 
	[RTA_SPORT]		= { .type = NLA_U16 },

	[RTA_DPORT]		= { .type = NLA_U16 },

	[RTA_NH_ID]		= { .type = NLA_U32 },

	[RTA_FLOWLABEL]		= { .type = NLA_BE32 },

};



static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
@@ -5030,6 +5031,12 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, 
		goto errout;

	}



	if (tb[RTA_FLOWLABEL]) {

		NL_SET_ERR_MSG_ATTR(extack, tb[RTA_FLOWLABEL],

				    "Flow label cannot be specified for this operation");

		goto errout;

	}



	*cfg = (struct fib6_config){

		.fc_table = rtm->rtm_table,

		.fc_dst_len = rtm->rtm_dst_len,
@@ -6013,6 +6020,13 @@ static int inet6_rtm_valid_getroute_req(struct sk_buff *skb, 
		return -EINVAL;

	}



	if (tb[RTA_FLOWLABEL] &&

	    (nla_get_be32(tb[RTA_FLOWLABEL]) & ~IPV6_FLOWLABEL_MASK)) {

		NL_SET_ERR_MSG_ATTR(extack, tb[RTA_FLOWLABEL],

				    "Invalid flow label");

		return -EINVAL;

	}



	for (i = 0; i <= RTA_MAX; i++) {

		if (!tb[i])

			continue;
@@ -6027,6 +6041,7 @@ static int inet6_rtm_valid_getroute_req(struct sk_buff *skb, 
		case RTA_SPORT:

		case RTA_DPORT:

		case RTA_IP_PROTO:

		case RTA_FLOWLABEL:

			break;

		default:

			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
@@ -6049,6 +6064,7 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 
	struct sk_buff *skb;

	struct rtmsg *rtm;

	struct flowi6 fl6 = {};

	__be32 flowlabel;

	bool fibmatch;



	err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
@@ -6057,7 +6073,6 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 


	err = -EINVAL;

	rtm = nlmsg_data(nlh);

	fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);

	fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);



	if (tb[RTA_SRC]) {
@@ -6103,6 +6118,9 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 
			goto errout;

	}



	flowlabel = nla_get_be32_default(tb[RTA_FLOWLABEL], 0);

	fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, flowlabel);



	if (iif) {

		struct net_device *dev;

		int flags = 0;