mirror of https://gitee.com/openkylin/linux.git
net: ipv6: Add support to dump multipath routes via RTA_MULTIPATH attribute
IPv6 returns multipath routes as a series of individual routes making their display and handling by userspace different and more complicated than IPv4, putting the burden on the user to see that a route is part of a multipath route and internally creating a multipath route if desired (e.g., libnl does this as of commit 29b71371e764). This patch addresses this difference, allowing multipath routes to be returned using the RTA_MULTIPATH attribute. The end result is that IPv6 multipath routes can be treated and displayed in a format similar to IPv4: $ ip -6 ro ls vrf red 2001:db8:1::/120 dev eth1 proto kernel metric 256 pref medium 2001:db8:2::/120 dev eth2 proto kernel metric 256 pref medium 2001:db8:200::/120 metric 1024 nexthop via 2001:db8:1::2 dev eth1 weight 1 nexthop via 2001:db8:2::2 dev eth2 weight 1 Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
parent
0ae8133586
commit
beb1afac51
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@ -318,6 +318,16 @@ static int fib6_dump_node(struct fib6_walker *w)
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w->leaf = rt;
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return 1;
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}
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/* Multipath routes are dumped in one route with the
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* RTA_MULTIPATH attribute. Jump 'rt' to point to the
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* last sibling of this route (no need to dump the
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* sibling routes again)
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*/
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if (rt->rt6i_nsiblings)
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rt = list_last_entry(&rt->rt6i_siblings,
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struct rt6_info,
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rt6i_siblings);
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}
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w->leaf = NULL;
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return 0;
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112
net/ipv6/route.c
112
net/ipv6/route.c
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@ -3195,8 +3195,20 @@ static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
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return ip6_route_add(&cfg);
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}
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static inline size_t rt6_nlmsg_size(struct rt6_info *rt)
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static size_t rt6_nlmsg_size(struct rt6_info *rt)
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{
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int nexthop_len = 0;
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if (rt->rt6i_nsiblings) {
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nexthop_len = nla_total_size(0) /* RTA_MULTIPATH */
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+ NLA_ALIGN(sizeof(struct rtnexthop))
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+ nla_total_size(16) /* RTA_GATEWAY */
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+ nla_total_size(4) /* RTA_OIF */
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+ lwtunnel_get_encap_size(rt->dst.lwtstate);
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nexthop_len *= rt->rt6i_nsiblings;
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}
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return NLMSG_ALIGN(sizeof(struct rtmsg))
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+ nla_total_size(16) /* RTA_SRC */
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+ nla_total_size(16) /* RTA_DST */
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@ -3210,7 +3222,62 @@ static inline size_t rt6_nlmsg_size(struct rt6_info *rt)
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+ nla_total_size(sizeof(struct rta_cacheinfo))
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+ nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
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+ nla_total_size(1) /* RTA_PREF */
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+ lwtunnel_get_encap_size(rt->dst.lwtstate);
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+ lwtunnel_get_encap_size(rt->dst.lwtstate)
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+ nexthop_len;
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}
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static int rt6_nexthop_info(struct sk_buff *skb, struct rt6_info *rt,
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unsigned int *flags)
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{
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if (!netif_running(rt->dst.dev) || !netif_carrier_ok(rt->dst.dev)) {
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*flags |= RTNH_F_LINKDOWN;
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if (rt->rt6i_idev->cnf.ignore_routes_with_linkdown)
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*flags |= RTNH_F_DEAD;
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}
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if (rt->rt6i_flags & RTF_GATEWAY) {
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if (nla_put_in6_addr(skb, RTA_GATEWAY, &rt->rt6i_gateway) < 0)
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goto nla_put_failure;
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}
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if (rt->dst.dev &&
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nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
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goto nla_put_failure;
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if (rt->dst.lwtstate &&
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lwtunnel_fill_encap(skb, rt->dst.lwtstate) < 0)
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -EMSGSIZE;
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}
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static int rt6_add_nexthop(struct sk_buff *skb, struct rt6_info *rt)
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{
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struct rtnexthop *rtnh;
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unsigned int flags = 0;
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rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
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if (!rtnh)
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goto nla_put_failure;
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rtnh->rtnh_hops = 0;
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rtnh->rtnh_ifindex = rt->dst.dev ? rt->dst.dev->ifindex : 0;
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if (rt6_nexthop_info(skb, rt, &flags) < 0)
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goto nla_put_failure;
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rtnh->rtnh_flags = flags;
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/* length of rtnetlink header + attributes */
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rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
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return 0;
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nla_put_failure:
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return -EMSGSIZE;
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}
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static int rt6_fill_node(struct net *net,
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@ -3264,11 +3331,6 @@ static int rt6_fill_node(struct net *net,
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else
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rtm->rtm_type = RTN_UNICAST;
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rtm->rtm_flags = 0;
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if (!netif_running(rt->dst.dev) || !netif_carrier_ok(rt->dst.dev)) {
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rtm->rtm_flags |= RTNH_F_LINKDOWN;
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if (rt->rt6i_idev->cnf.ignore_routes_with_linkdown)
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rtm->rtm_flags |= RTNH_F_DEAD;
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}
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rtm->rtm_scope = RT_SCOPE_UNIVERSE;
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rtm->rtm_protocol = rt->rt6i_protocol;
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if (rt->rt6i_flags & RTF_DYNAMIC)
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@ -3332,17 +3394,35 @@ static int rt6_fill_node(struct net *net,
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if (rtnetlink_put_metrics(skb, metrics) < 0)
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goto nla_put_failure;
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if (rt->rt6i_flags & RTF_GATEWAY) {
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if (nla_put_in6_addr(skb, RTA_GATEWAY, &rt->rt6i_gateway) < 0)
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goto nla_put_failure;
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}
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if (rt->dst.dev &&
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nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex))
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goto nla_put_failure;
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if (nla_put_u32(skb, RTA_PRIORITY, rt->rt6i_metric))
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goto nla_put_failure;
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/* For multipath routes, walk the siblings list and add
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* each as a nexthop within RTA_MULTIPATH.
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*/
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if (rt->rt6i_nsiblings) {
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struct rt6_info *sibling, *next_sibling;
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struct nlattr *mp;
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mp = nla_nest_start(skb, RTA_MULTIPATH);
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if (!mp)
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goto nla_put_failure;
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if (rt6_add_nexthop(skb, rt) < 0)
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goto nla_put_failure;
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list_for_each_entry_safe(sibling, next_sibling,
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&rt->rt6i_siblings, rt6i_siblings) {
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if (rt6_add_nexthop(skb, sibling) < 0)
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goto nla_put_failure;
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}
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nla_nest_end(skb, mp);
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} else {
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if (rt6_nexthop_info(skb, rt, &rtm->rtm_flags) < 0)
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goto nla_put_failure;
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}
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expires = (rt->rt6i_flags & RTF_EXPIRES) ? rt->dst.expires - jiffies : 0;
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if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, rt->dst.error) < 0)
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@ -3351,8 +3431,6 @@ static int rt6_fill_node(struct net *net,
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if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt->rt6i_flags)))
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goto nla_put_failure;
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if (lwtunnel_fill_encap(skb, rt->dst.lwtstate) < 0)
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goto nla_put_failure;
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nlmsg_end(skb, nlh);
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return 0;
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