diff options
Diffstat (limited to 'net/ipv6/route.c')
| -rw-r--r-- | net/ipv6/route.c | 141 |
1 files changed, 115 insertions, 26 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 1054b059747f..1076ae0ea9d5 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -455,7 +455,6 @@ static struct rt6_info *rt6_multipath_select(struct rt6_info *match, int strict) { struct rt6_info *sibling, *next_sibling; - int route_choosen; /* We might have already computed the hash for ICMPv6 errors. In such * case it will always be non-zero. Otherwise now is the time to do it. @@ -463,28 +462,19 @@ static struct rt6_info *rt6_multipath_select(struct rt6_info *match, if (!fl6->mp_hash) fl6->mp_hash = rt6_multipath_hash(fl6, NULL); - route_choosen = fl6->mp_hash % (match->rt6i_nsiblings + 1); - /* Don't change the route, if route_choosen == 0 - * (siblings does not include ourself) - */ - if (route_choosen) - list_for_each_entry_safe(sibling, next_sibling, - &match->rt6i_siblings, rt6i_siblings) { - route_choosen--; - if (route_choosen == 0) { - struct inet6_dev *idev = sibling->rt6i_idev; - - if (sibling->rt6i_nh_flags & RTNH_F_DEAD) - break; - if (sibling->rt6i_nh_flags & RTNH_F_LINKDOWN && - idev->cnf.ignore_routes_with_linkdown) - break; - if (rt6_score_route(sibling, oif, strict) < 0) - break; - match = sibling; - break; - } - } + if (fl6->mp_hash <= atomic_read(&match->rt6i_nh_upper_bound)) + return match; + + list_for_each_entry_safe(sibling, next_sibling, &match->rt6i_siblings, + rt6i_siblings) { + if (fl6->mp_hash > atomic_read(&sibling->rt6i_nh_upper_bound)) + continue; + if (rt6_score_route(sibling, oif, strict) < 0) + break; + match = sibling; + break; + } + return match; } @@ -1833,10 +1823,10 @@ u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb) if (skb) { ip6_multipath_l3_keys(skb, &hash_keys); - return flow_hash_from_keys(&hash_keys); + return flow_hash_from_keys(&hash_keys) >> 1; } - return get_hash_from_flowi6(fl6); + return get_hash_from_flowi6(fl6) >> 1; } void ip6_route_input(struct sk_buff *skb) @@ -2604,6 +2594,7 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg, #endif rt->rt6i_metric = cfg->fc_metric; + rt->rt6i_nh_weight = 1; /* We cannot add true routes via loopback here, they would result in kernel looping; promote them to reject routes @@ -3481,6 +3472,99 @@ struct arg_netdev_event { }; }; +static struct rt6_info *rt6_multipath_first_sibling(const struct rt6_info *rt) +{ + struct rt6_info *iter; + struct fib6_node *fn; + + fn = rcu_dereference_protected(rt->rt6i_node, + lockdep_is_held(&rt->rt6i_table->tb6_lock)); + iter = rcu_dereference_protected(fn->leaf, + lockdep_is_held(&rt->rt6i_table->tb6_lock)); + while (iter) { + if (iter->rt6i_metric == rt->rt6i_metric && + rt6_qualify_for_ecmp(iter)) + return iter; + iter = rcu_dereference_protected(iter->rt6_next, + lockdep_is_held(&rt->rt6i_table->tb6_lock)); + } + + return NULL; +} + +static bool rt6_is_dead(const struct rt6_info *rt) +{ + if (rt->rt6i_nh_flags & RTNH_F_DEAD || + (rt->rt6i_nh_flags & RTNH_F_LINKDOWN && + rt->rt6i_idev->cnf.ignore_routes_with_linkdown)) + return true; + + return false; +} + +static int rt6_multipath_total_weight(const struct rt6_info *rt) +{ + struct rt6_info *iter; + int total = 0; + + if (!rt6_is_dead(rt)) + total += rt->rt6i_nh_weight; + + list_for_each_entry(iter, &rt->rt6i_siblings, rt6i_siblings) { + if (!rt6_is_dead(iter)) + total += iter->rt6i_nh_weight; + } + + return total; +} + +static void rt6_upper_bound_set(struct rt6_info *rt, int *weight, int total) +{ + int upper_bound = -1; + + if (!rt6_is_dead(rt)) { + *weight += rt->rt6i_nh_weight; + upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31, + total) - 1; + } + atomic_set(&rt->rt6i_nh_upper_bound, upper_bound); +} + +static void rt6_multipath_upper_bound_set(struct rt6_info *rt, int total) +{ + struct rt6_info *iter; + int weight = 0; + + rt6_upper_bound_set(rt, &weight, total); + + list_for_each_entry(iter, &rt->rt6i_siblings, rt6i_siblings) + rt6_upper_bound_set(iter, &weight, total); +} + +void rt6_multipath_rebalance(struct rt6_info *rt) +{ + struct rt6_info *first; + int total; + + /* In case the entire multipath route was marked for flushing, + * then there is no need to rebalance upon the removal of every + * sibling route. + */ + if (!rt->rt6i_nsiblings || rt->should_flush) + return; + + /* During lookup routes are evaluated in order, so we need to + * make sure upper bounds are assigned from the first sibling + * onwards. + */ + first = rt6_multipath_first_sibling(rt); + if (WARN_ON_ONCE(!first)) + return; + + total = rt6_multipath_total_weight(first); + rt6_multipath_upper_bound_set(first, total); +} + static int fib6_ifup(struct rt6_info *rt, void *p_arg) { const struct arg_netdev_event *arg = p_arg; @@ -3489,6 +3573,7 @@ static int fib6_ifup(struct rt6_info *rt, void *p_arg) if (rt != net->ipv6.ip6_null_entry && rt->dst.dev == arg->dev) { rt->rt6i_nh_flags &= ~arg->nh_flags; fib6_update_sernum_upto_root(dev_net(rt->dst.dev), rt); + rt6_multipath_rebalance(rt); } return 0; @@ -3588,6 +3673,7 @@ static int fib6_ifdown(struct rt6_info *rt, void *p_arg) rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD | RTNH_F_LINKDOWN); fib6_update_sernum(rt); + rt6_multipath_rebalance(rt); } return -2; case NETDEV_CHANGE: @@ -3595,6 +3681,7 @@ static int fib6_ifdown(struct rt6_info *rt, void *p_arg) rt->rt6i_flags & (RTF_LOCAL | RTF_ANYCAST)) break; rt->rt6i_nh_flags |= RTNH_F_LINKDOWN; + rt6_multipath_rebalance(rt); break; } @@ -3938,6 +4025,8 @@ static int ip6_route_multipath_add(struct fib6_config *cfg, goto cleanup; } + rt->rt6i_nh_weight = rtnh->rtnh_hops + 1; + err = ip6_route_info_append(&rt6_nh_list, rt, &r_cfg); if (err) { dst_release_immediate(&rt->dst); @@ -4160,7 +4249,7 @@ static int rt6_add_nexthop(struct sk_buff *skb, struct rt6_info *rt) if (!rtnh) goto nla_put_failure; - rtnh->rtnh_hops = 0; + rtnh->rtnh_hops = rt->rt6i_nh_weight - 1; rtnh->rtnh_ifindex = rt->dst.dev ? rt->dst.dev->ifindex : 0; if (rt6_nexthop_info(skb, rt, &flags, true) < 0) |