diff options
| -rw-r--r-- | include/net/ip6_fib.h | 1 | ||||
| -rw-r--r-- | include/net/ip6_route.h | 7 | ||||
| -rw-r--r-- | net/ipv6/ip6_fib.c | 8 | ||||
| -rw-r--r-- | net/ipv6/route.c | 96 |
4 files changed, 106 insertions, 6 deletions
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index ddf53dd1e948..97cd05d87780 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -149,6 +149,7 @@ struct rt6_info { */ struct list_head rt6i_siblings; unsigned int rt6i_nsiblings; + atomic_t rt6i_nh_upper_bound; atomic_t rt6i_ref; diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index 34cd3b0c6ded..27d23a65f3cd 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -66,6 +66,12 @@ static inline bool rt6_need_strict(const struct in6_addr *daddr) (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK); } +static inline bool rt6_qualify_for_ecmp(const struct rt6_info *rt) +{ + return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == + RTF_GATEWAY; +} + void ip6_route_input(struct sk_buff *skb); struct dst_entry *ip6_route_input_lookup(struct net *net, struct net_device *dev, @@ -171,6 +177,7 @@ void rt6_clean_tohost(struct net *net, struct in6_addr *gateway); void rt6_sync_up(struct net_device *dev, unsigned int nh_flags); void rt6_disable_ip(struct net_device *dev, unsigned long event); void rt6_sync_down_dev(struct net_device *dev, unsigned long event); +void rt6_multipath_rebalance(struct rt6_info *rt); static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb) { diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index b5f19703fca6..e31118f417b4 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -796,12 +796,6 @@ insert_above: return ln; } -static bool rt6_qualify_for_ecmp(struct rt6_info *rt) -{ - return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == - RTF_GATEWAY; -} - static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc) { int i; @@ -991,6 +985,7 @@ next_iter: rt6i_nsiblings++; } BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings); + rt6_multipath_rebalance(temp_sibling); } /* @@ -1672,6 +1667,7 @@ static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, sibling->rt6i_nsiblings--; rt->rt6i_nsiblings = 0; list_del_init(&rt->rt6i_siblings); + rt6_multipath_rebalance(next_sibling); } /* Adjust walkers */ diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 1054b059747f..ced2c9bed10b 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -3481,6 +3481,99 @@ 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++; + + list_for_each_entry(iter, &rt->rt6i_siblings, rt6i_siblings) { + if (!rt6_is_dead(iter)) + total++; + } + + 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)++; + 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 +3582,7 @@ 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 +3682,7 @@ 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 +3690,7 @@ 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; } |