From: Ido Schimmel Date: Mon, 16 Dec 2024 17:11:58 +0000 (+0200) Subject: ipv6: Add flow label to route get requests X-Git-Tag: block-6.14-20240131~28^2~186^2~3 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=ba4138032ae3b5b8e2b68d2f2647cdc0817b05a6;p=linux-block.git 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: Petr Machata Signed-off-by: Ido Schimmel Reviewed-by: Guillaume Nault Signed-off-by: Paolo Abeni --- diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h index eccc0e7dcb7d..5ee94c511a28 100644 --- a/include/uapi/linux/rtnetlink.h +++ b/include/uapi/linux/rtnetlink.h @@ -393,6 +393,7 @@ enum rtattr_type_t { RTA_SPORT, RTA_DPORT, RTA_NH_ID, + RTA_FLOWLABEL, __RTA_MAX }; diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 67ff16c04718..78362822b907 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -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;