From c89359a42e2a49656451569c382eed63e781153c Mon Sep 17 00:00:00 2001 From: Roopa Prabhu Date: Tue, 1 Dec 2015 22:18:11 -0800 Subject: mpls: support for dead routes Adds support for RTNH_F_DEAD and RTNH_F_LINKDOWN flags on mpls routes due to link events. Also adds code to ignore dead routes during route selection. Unlike ip routes, mpls routes are not deleted when the route goes dead. This is current mpls behaviour and this patch does not change that. With this patch however, routes will be marked dead. dead routes are not notified to userspace (this is consistent with ipv4 routes). dead routes: ----------- $ip -f mpls route show 100 nexthop as to 200 via inet 10.1.1.2 dev swp1 nexthop as to 700 via inet 10.1.1.6 dev swp2 $ip link set dev swp1 down $ip link show dev swp1 4: swp1: mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000 link/ether 00:02:00:00:00:01 brd ff:ff:ff:ff:ff:ff $ip -f mpls route show 100 nexthop as to 200 via inet 10.1.1.2 dev swp1 dead linkdown nexthop as to 700 via inet 10.1.1.6 dev swp2 linkdown routes: ---------------- $ip -f mpls route show 100 nexthop as to 200 via inet 10.1.1.2 dev swp1 nexthop as to 700 via inet 10.1.1.6 dev swp2 $ip link show dev swp1 4: swp1: mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000 link/ether 00:02:00:00:00:01 brd ff:ff:ff:ff:ff:ff /* carrier goes down */ $ip link show dev swp1 4: swp1: mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000 link/ether 00:02:00:00:00:01 brd ff:ff:ff:ff:ff:ff $ip -f mpls route show 100 nexthop as to 200 via inet 10.1.1.2 dev swp1 linkdown nexthop as to 700 via inet 10.1.1.6 dev swp2 Signed-off-by: Roopa Prabhu Acked-by: Robert Shearman Signed-off-by: David S. Miller --- net/mpls/af_mpls.c | 185 ++++++++++++++++++++++++++++++++++++++++++++-------- net/mpls/internal.h | 2 + 2 files changed, 159 insertions(+), 28 deletions(-) (limited to 'net/mpls') diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index c70d750148b6..4b3b9b310c3a 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -96,22 +96,15 @@ bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) } EXPORT_SYMBOL_GPL(mpls_pkt_too_big); -static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt, - struct sk_buff *skb, bool bos) +static u32 mpls_multipath_hash(struct mpls_route *rt, + struct sk_buff *skb, bool bos) { struct mpls_entry_decoded dec; struct mpls_shim_hdr *hdr; bool eli_seen = false; int label_index; - int nh_index = 0; u32 hash = 0; - /* No need to look further into packet if there's only - * one path - */ - if (rt->rt_nhn == 1) - goto out; - for (label_index = 0; label_index < MAX_MP_SELECT_LABELS && !bos; label_index++) { if (!pskb_may_pull(skb, sizeof(*hdr) * label_index)) @@ -165,7 +158,38 @@ static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt, } } - nh_index = hash % rt->rt_nhn; + return hash; +} + +static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt, + struct sk_buff *skb, bool bos) +{ + int alive = ACCESS_ONCE(rt->rt_nhn_alive); + u32 hash = 0; + int nh_index = 0; + int n = 0; + + /* No need to look further into packet if there's only + * one path + */ + if (rt->rt_nhn == 1) + goto out; + + if (alive <= 0) + return NULL; + + hash = mpls_multipath_hash(rt, skb, bos); + nh_index = hash % alive; + if (alive == rt->rt_nhn) + goto out; + for_nexthops(rt) { + if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) + continue; + if (n == nh_index) + return nh; + n++; + } endfor_nexthops(rt); + out: return &rt->rt_nh[nh_index]; } @@ -365,6 +389,7 @@ static struct mpls_route *mpls_rt_alloc(int num_nh, u8 max_alen) GFP_KERNEL); if (rt) { rt->rt_nhn = num_nh; + rt->rt_nhn_alive = num_nh; rt->rt_max_alen = max_alen_aligned; } @@ -536,6 +561,16 @@ static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt, RCU_INIT_POINTER(nh->nh_dev, dev); + if (!(dev->flags & IFF_UP)) { + nh->nh_flags |= RTNH_F_DEAD; + } else { + unsigned int flags; + + flags = dev_get_flags(dev); + if (!(flags & (IFF_RUNNING | IFF_LOWER_UP))) + nh->nh_flags |= RTNH_F_LINKDOWN; + } + return 0; errout: @@ -570,6 +605,9 @@ static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg, if (err) goto errout; + if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) + rt->rt_nhn_alive--; + return 0; errout: @@ -577,8 +615,8 @@ errout: } static int mpls_nh_build(struct net *net, struct mpls_route *rt, - struct mpls_nh *nh, int oif, - struct nlattr *via, struct nlattr *newdst) + struct mpls_nh *nh, int oif, struct nlattr *via, + struct nlattr *newdst) { int err = -ENOMEM; @@ -681,11 +719,13 @@ static int mpls_nh_build_multi(struct mpls_route_config *cfg, goto errout; err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh, - rtnh->rtnh_ifindex, nla_via, - nla_newdst); + rtnh->rtnh_ifindex, nla_via, nla_newdst); if (err) goto errout; + if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) + rt->rt_nhn_alive--; + rtnh = rtnh_next(rtnh, &remaining); nhs++; } endfor_nexthops(rt); @@ -875,34 +915,74 @@ free: return ERR_PTR(err); } -static void mpls_ifdown(struct net_device *dev) +static void mpls_ifdown(struct net_device *dev, int event) { struct mpls_route __rcu **platform_label; struct net *net = dev_net(dev); - struct mpls_dev *mdev; unsigned index; platform_label = rtnl_dereference(net->mpls.platform_label); for (index = 0; index < net->mpls.platform_labels; index++) { struct mpls_route *rt = rtnl_dereference(platform_label[index]); + if (!rt) continue; - for_nexthops(rt) { + + change_nexthops(rt) { if (rtnl_dereference(nh->nh_dev) != dev) continue; - nh->nh_dev = NULL; + switch (event) { + case NETDEV_DOWN: + case NETDEV_UNREGISTER: + nh->nh_flags |= RTNH_F_DEAD; + /* fall through */ + case NETDEV_CHANGE: + nh->nh_flags |= RTNH_F_LINKDOWN; + ACCESS_ONCE(rt->rt_nhn_alive) = rt->rt_nhn_alive - 1; + break; + } + if (event == NETDEV_UNREGISTER) + RCU_INIT_POINTER(nh->nh_dev, NULL); } endfor_nexthops(rt); } - mdev = mpls_dev_get(dev); - if (!mdev) - return; - mpls_dev_sysctl_unregister(mdev); + return; +} + +static void mpls_ifup(struct net_device *dev, unsigned int nh_flags) +{ + struct mpls_route __rcu **platform_label; + struct net *net = dev_net(dev); + unsigned index; + int alive; + + platform_label = rtnl_dereference(net->mpls.platform_label); + for (index = 0; index < net->mpls.platform_labels; index++) { + struct mpls_route *rt = rtnl_dereference(platform_label[index]); + + if (!rt) + continue; + + alive = 0; + change_nexthops(rt) { + struct net_device *nh_dev = + rtnl_dereference(nh->nh_dev); + + if (!(nh->nh_flags & nh_flags)) { + alive++; + continue; + } + if (nh_dev != dev) + continue; + alive++; + nh->nh_flags &= ~nh_flags; + } endfor_nexthops(rt); - RCU_INIT_POINTER(dev->mpls_ptr, NULL); + ACCESS_ONCE(rt->rt_nhn_alive) = alive; + } - kfree_rcu(mdev, rcu); + return; } static int mpls_dev_notify(struct notifier_block *this, unsigned long event, @@ -910,9 +990,9 @@ static int mpls_dev_notify(struct notifier_block *this, unsigned long event, { struct net_device *dev = netdev_notifier_info_to_dev(ptr); struct mpls_dev *mdev; + unsigned int flags; - switch(event) { - case NETDEV_REGISTER: + if (event == NETDEV_REGISTER) { /* For now just support ethernet devices */ if ((dev->type == ARPHRD_ETHER) || (dev->type == ARPHRD_LOOPBACK)) { @@ -920,10 +1000,39 @@ static int mpls_dev_notify(struct notifier_block *this, unsigned long event, if (IS_ERR(mdev)) return notifier_from_errno(PTR_ERR(mdev)); } - break; + return NOTIFY_OK; + } + mdev = mpls_dev_get(dev); + if (!mdev) + return NOTIFY_OK; + + switch (event) { + case NETDEV_DOWN: + mpls_ifdown(dev, event); + break; + case NETDEV_UP: + flags = dev_get_flags(dev); + if (flags & (IFF_RUNNING | IFF_LOWER_UP)) + mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); + else + mpls_ifup(dev, RTNH_F_DEAD); + break; + case NETDEV_CHANGE: + flags = dev_get_flags(dev); + if (flags & (IFF_RUNNING | IFF_LOWER_UP)) + mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); + else + mpls_ifdown(dev, event); + break; case NETDEV_UNREGISTER: - mpls_ifdown(dev); + mpls_ifdown(dev, event); + mdev = mpls_dev_get(dev); + if (mdev) { + mpls_dev_sysctl_unregister(mdev); + RCU_INIT_POINTER(dev->mpls_ptr, NULL); + kfree_rcu(mdev, rcu); + } break; case NETDEV_CHANGENAME: mdev = mpls_dev_get(dev); @@ -1237,9 +1346,15 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event, dev = rtnl_dereference(nh->nh_dev); if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex)) goto nla_put_failure; + if (nh->nh_flags & RTNH_F_LINKDOWN) + rtm->rtm_flags |= RTNH_F_LINKDOWN; + if (nh->nh_flags & RTNH_F_DEAD) + rtm->rtm_flags |= RTNH_F_DEAD; } else { struct rtnexthop *rtnh; struct nlattr *mp; + int dead = 0; + int linkdown = 0; mp = nla_nest_start(skb, RTA_MULTIPATH); if (!mp) @@ -1253,6 +1368,15 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event, dev = rtnl_dereference(nh->nh_dev); if (dev) rtnh->rtnh_ifindex = dev->ifindex; + if (nh->nh_flags & RTNH_F_LINKDOWN) { + rtnh->rtnh_flags |= RTNH_F_LINKDOWN; + linkdown++; + } + if (nh->nh_flags & RTNH_F_DEAD) { + rtnh->rtnh_flags |= RTNH_F_DEAD; + dead++; + } + if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST, nh->nh_labels, nh->nh_label)) @@ -1266,6 +1390,11 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event, rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh; } endfor_nexthops(rt); + if (linkdown == rt->rt_nhn) + rtm->rtm_flags |= RTNH_F_LINKDOWN; + if (dead == rt->rt_nhn) + rtm->rtm_flags |= RTNH_F_DEAD; + nla_nest_end(skb, mp); } diff --git a/net/mpls/internal.h b/net/mpls/internal.h index bde52ce88c94..732a5c17e986 100644 --- a/net/mpls/internal.h +++ b/net/mpls/internal.h @@ -41,6 +41,7 @@ enum mpls_payload_type { struct mpls_nh { /* next hop label forwarding entry */ struct net_device __rcu *nh_dev; + unsigned int nh_flags; u32 nh_label[MAX_NEW_LABELS]; u8 nh_labels; u8 nh_via_alen; @@ -74,6 +75,7 @@ struct mpls_route { /* next hop label forwarding entry */ u8 rt_payload_type; u8 rt_max_alen; unsigned int rt_nhn; + unsigned int rt_nhn_alive; struct mpls_nh rt_nh[0]; }; -- cgit v1.2.3 From 6e71b29908e9e9bffc03b8e991c9e58a0fa92d9c Mon Sep 17 00:00:00 2001 From: Roopa Prabhu Date: Wed, 9 Dec 2015 06:56:41 -0800 Subject: mpls_iptunnel: add static qualifier to mpls_output This gets rid of the following compile warn: net/mpls/mpls_iptunnel.c:40:5: warning: no previous prototype for mpls_output [-Wmissing-prototypes] Signed-off-by: Roopa Prabhu Acked-by: Robert Shearman Signed-off-by: David S. Miller --- net/mpls/mpls_iptunnel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/mpls') diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c index 67591aef9cae..cdd01e6416db 100644 --- a/net/mpls/mpls_iptunnel.c +++ b/net/mpls/mpls_iptunnel.c @@ -37,7 +37,7 @@ static unsigned int mpls_encap_size(struct mpls_iptunnel_encap *en) return en->labels * sizeof(struct mpls_shim_hdr); } -int mpls_output(struct net *net, struct sock *sk, struct sk_buff *skb) +static int mpls_output(struct net *net, struct sock *sk, struct sk_buff *skb) { struct mpls_iptunnel_encap *tun_encap_info; struct mpls_shim_hdr *hdr; -- cgit v1.2.3