diff options
author | David S. Miller <davem@davemloft.net> | 2019-04-11 14:24:07 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2019-04-11 14:24:07 -0700 |
commit | 78f07adac86186b5ef0318b7faec377b6d31ea9f (patch) | |
tree | 4c67f46492b695373ffde163f26ef2e3c7bb8594 | |
parent | 62720b12d20aecebc2e74642c37a3dc84717ac7a (diff) | |
parent | 0b34eb004347308ed0952ddb5b3898a71869ac3c (diff) | |
download | linux-78f07adac86186b5ef0318b7faec377b6d31ea9f.tar.bz2 |
Merge branch 'ipv6-Refactor-nexthop-selection-helpers-during-a-fib-lookup'
David Ahern says:
====================
ipv6: Refactor nexthop selection helpers during a fib lookup
IPv6 has a fib6_nh embedded within each fib6_info and a separate
fib6_info for each path in a multipath route. A side effect is that
a fib6_info is passed all the way down the stack when selecting a path
on a fib lookup. Refactor the fib lookup functions and associated
helper functions to take a fib6_nh when appropriate to enable IPv6
to work with nexthop objects where the fib6_nh is not directly part
of a fib entry.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | include/net/ip6_fib.h | 8 | ||||
-rw-r--r-- | net/ipv6/route.c | 266 |
2 files changed, 149 insertions, 125 deletions
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index 58dbb4e82908..2e9235adfa0d 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -127,6 +127,10 @@ struct rt6_exception { struct fib6_nh { struct fib_nh_common nh_common; + +#ifdef CONFIG_IPV6_ROUTER_PREF + unsigned long last_probe; +#endif }; struct fib6_info { @@ -155,10 +159,6 @@ struct fib6_info { struct rt6_info * __percpu *rt6i_pcpu; struct rt6_exception_bucket __rcu *rt6i_exception_bucket; -#ifdef CONFIG_IPV6_ROUTER_PREF - unsigned long last_probe; -#endif - u32 fib6_metric; u8 fib6_protocol; u8 fib6_type; diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 69f92d2b780e..d555edaaff13 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -102,7 +102,8 @@ static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb, u32 mtu); static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb); -static int rt6_score_route(struct fib6_info *rt, int oif, int strict); +static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif, + int strict); static size_t rt6_nlmsg_size(struct fib6_info *rt); static int rt6_fill_node(struct net *net, struct sk_buff *skb, struct fib6_info *rt, struct dst_entry *dst, @@ -446,12 +447,13 @@ struct fib6_info *fib6_multipath_select(const struct net *net, list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings, fib6_siblings) { + const struct fib6_nh *nh = &sibling->fib6_nh; int nh_upper_bound; - nh_upper_bound = atomic_read(&sibling->fib6_nh.fib_nh_upper_bound); + nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound); if (fl6->mp_hash > nh_upper_bound) continue; - if (rt6_score_route(sibling, oif, strict) < 0) + if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0) break; match = sibling; break; @@ -464,12 +466,34 @@ struct fib6_info *fib6_multipath_select(const struct net *net, * Route lookup. rcu_read_lock() should be held. */ +static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh, + const struct in6_addr *saddr, int oif, int flags) +{ + const struct net_device *dev; + + if (nh->fib_nh_flags & RTNH_F_DEAD) + return false; + + dev = nh->fib_nh_dev; + if (oif) { + if (dev->ifindex == oif) + return true; + } else { + if (ipv6_chk_addr(net, saddr, dev, + flags & RT6_LOOKUP_F_IFACE)) + return true; + } + + return false; +} + static inline struct fib6_info *rt6_device_match(struct net *net, struct fib6_info *rt, const struct in6_addr *saddr, int oif, int flags) { + const struct fib6_nh *nh; struct fib6_info *sprt; if (!oif && ipv6_addr_any(saddr) && @@ -477,19 +501,9 @@ static inline struct fib6_info *rt6_device_match(struct net *net, return rt; for (sprt = rt; sprt; sprt = rcu_dereference(sprt->fib6_next)) { - const struct net_device *dev = sprt->fib6_nh.fib_nh_dev; - - if (sprt->fib6_nh.fib_nh_flags & RTNH_F_DEAD) - continue; - - if (oif) { - if (dev->ifindex == oif) - return sprt; - } else { - if (ipv6_chk_addr(net, saddr, dev, - flags & RT6_LOOKUP_F_IFACE)) - return sprt; - } + nh = &sprt->fib6_nh; + if (__rt6_device_match(net, nh, saddr, oif, flags)) + return sprt; } if (oif && flags & RT6_LOOKUP_F_IFACE) @@ -517,7 +531,7 @@ static void rt6_probe_deferred(struct work_struct *w) kfree(work); } -static void rt6_probe(struct fib6_info *rt) +static void rt6_probe(struct fib6_nh *fib6_nh) { struct __rt6_probe_work *work = NULL; const struct in6_addr *nh_gw; @@ -533,11 +547,11 @@ static void rt6_probe(struct fib6_info *rt) * Router Reachability Probe MUST be rate-limited * to no more than one per minute. */ - if (!rt || !rt->fib6_nh.fib_nh_gw_family) + if (fib6_nh->fib_nh_gw_family) return; - nh_gw = &rt->fib6_nh.fib_nh_gw6; - dev = rt->fib6_nh.fib_nh_dev; + nh_gw = &fib6_nh->fib_nh_gw6; + dev = fib6_nh->fib_nh_dev; rcu_read_lock_bh(); idev = __in6_dev_get(dev); neigh = __ipv6_neigh_lookup_noref(dev, nh_gw); @@ -554,13 +568,13 @@ static void rt6_probe(struct fib6_info *rt) __neigh_set_probe_once(neigh); } write_unlock(&neigh->lock); - } else if (time_after(jiffies, rt->last_probe + + } else if (time_after(jiffies, fib6_nh->last_probe + idev->cnf.rtr_probe_interval)) { work = kmalloc(sizeof(*work), GFP_ATOMIC); } if (work) { - rt->last_probe = jiffies; + fib6_nh->last_probe = jiffies; INIT_WORK(&work->work, rt6_probe_deferred); work->target = *nh_gw; dev_hold(dev); @@ -572,7 +586,7 @@ out: rcu_read_unlock_bh(); } #else -static inline void rt6_probe(struct fib6_info *rt) +static inline void rt6_probe(struct fib6_nh *fib6_nh) { } #endif @@ -580,27 +594,14 @@ static inline void rt6_probe(struct fib6_info *rt) /* * Default Router Selection (RFC 2461 6.3.6) */ -static inline int rt6_check_dev(struct fib6_info *rt, int oif) -{ - const struct net_device *dev = rt->fib6_nh.fib_nh_dev; - - if (!oif || dev->ifindex == oif) - return 2; - return 0; -} - -static inline enum rt6_nud_state rt6_check_neigh(struct fib6_info *rt) +static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh) { enum rt6_nud_state ret = RT6_NUD_FAIL_HARD; struct neighbour *neigh; - if (rt->fib6_flags & RTF_NONEXTHOP || - !rt->fib6_nh.fib_nh_gw_family) - return RT6_NUD_SUCCEED; - rcu_read_lock_bh(); - neigh = __ipv6_neigh_lookup_noref(rt->fib6_nh.fib_nh_dev, - &rt->fib6_nh.fib_nh_gw6); + neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev, + &fib6_nh->fib_nh_gw6); if (neigh) { read_lock(&neigh->lock); if (neigh->nud_state & NUD_VALID) @@ -621,43 +622,44 @@ static inline enum rt6_nud_state rt6_check_neigh(struct fib6_info *rt) return ret; } -static int rt6_score_route(struct fib6_info *rt, int oif, int strict) +static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif, + int strict) { - int m; + int m = 0; + + if (!oif || nh->fib_nh_dev->ifindex == oif) + m = 2; - m = rt6_check_dev(rt, oif); if (!m && (strict & RT6_LOOKUP_F_IFACE)) return RT6_NUD_FAIL_HARD; #ifdef CONFIG_IPV6_ROUTER_PREF - m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->fib6_flags)) << 2; + m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2; #endif - if (strict & RT6_LOOKUP_F_REACHABLE) { - int n = rt6_check_neigh(rt); + if ((strict & RT6_LOOKUP_F_REACHABLE) && + !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) { + int n = rt6_check_neigh(nh); if (n < 0) return n; } return m; } -static struct fib6_info *find_match(struct fib6_info *rt, int oif, int strict, - int *mpri, struct fib6_info *match, - bool *do_rr) +static bool find_match(struct fib6_nh *nh, u32 fib6_flags, + int oif, int strict, int *mpri, bool *do_rr) { - int m; bool match_do_rr = false; + bool rc = false; + int m; - if (rt->fib6_nh.fib_nh_flags & RTNH_F_DEAD) + if (nh->fib_nh_flags & RTNH_F_DEAD) goto out; - if (ip6_ignore_linkdown(rt->fib6_nh.fib_nh_dev) && - rt->fib6_nh.fib_nh_flags & RTNH_F_LINKDOWN && + if (ip6_ignore_linkdown(nh->fib_nh_dev) && + nh->fib_nh_flags & RTNH_F_LINKDOWN && !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE)) goto out; - if (fib6_check_expired(rt)) - goto out; - - m = rt6_score_route(rt, oif, strict); + m = rt6_score_route(nh, fib6_flags, oif, strict); if (m == RT6_NUD_FAIL_DO_RR) { match_do_rr = true; m = 0; /* lowest valid score */ @@ -666,53 +668,64 @@ static struct fib6_info *find_match(struct fib6_info *rt, int oif, int strict, } if (strict & RT6_LOOKUP_F_REACHABLE) - rt6_probe(rt); + rt6_probe(nh); /* note that m can be RT6_NUD_FAIL_PROBE at this point */ if (m > *mpri) { *do_rr = match_do_rr; *mpri = m; - match = rt; + rc = true; } out: - return match; + return rc; } -static struct fib6_info *find_rr_leaf(struct fib6_node *fn, - struct fib6_info *leaf, - struct fib6_info *rr_head, - u32 metric, int oif, int strict, - bool *do_rr) +static void __find_rr_leaf(struct fib6_info *rt_start, + struct fib6_info *nomatch, u32 metric, + struct fib6_info **match, struct fib6_info **cont, + int oif, int strict, bool *do_rr, int *mpri) { - struct fib6_info *rt, *match, *cont; - int mpri = -1; + struct fib6_info *rt; - match = NULL; - cont = NULL; - for (rt = rr_head; rt; rt = rcu_dereference(rt->fib6_next)) { - if (rt->fib6_metric != metric) { - cont = rt; - break; + for (rt = rt_start; + rt && rt != nomatch; + rt = rcu_dereference(rt->fib6_next)) { + struct fib6_nh *nh; + + if (cont && rt->fib6_metric != metric) { + *cont = rt; + return; } - match = find_match(rt, oif, strict, &mpri, match, do_rr); + if (fib6_check_expired(rt)) + continue; + + nh = &rt->fib6_nh; + if (find_match(nh, rt->fib6_flags, oif, strict, mpri, do_rr)) + *match = rt; } +} - for (rt = leaf; rt && rt != rr_head; - rt = rcu_dereference(rt->fib6_next)) { - if (rt->fib6_metric != metric) { - cont = rt; - break; - } +static struct fib6_info *find_rr_leaf(struct fib6_node *fn, + struct fib6_info *leaf, + struct fib6_info *rr_head, + u32 metric, int oif, int strict, + bool *do_rr) +{ + struct fib6_info *match = NULL, *cont = NULL; + int mpri = -1; - match = find_match(rt, oif, strict, &mpri, match, do_rr); - } + __find_rr_leaf(rr_head, NULL, metric, &match, &cont, + oif, strict, do_rr, &mpri); + + __find_rr_leaf(leaf, rr_head, metric, &match, &cont, + oif, strict, do_rr, &mpri); if (match || !cont) return match; - for (rt = cont; rt; rt = rcu_dereference(rt->fib6_next)) - match = find_match(rt, oif, strict, &mpri, match, do_rr); + __find_rr_leaf(cont, NULL, metric, &match, NULL, + oif, strict, do_rr, &mpri); return match; } @@ -1061,36 +1074,37 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net, fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); restart: f6i = rcu_dereference(fn->leaf); - if (!f6i) { + if (!f6i) f6i = net->ipv6.fib6_null_entry; - } else { + else f6i = rt6_device_match(net, f6i, &fl6->saddr, fl6->flowi6_oif, flags); - if (f6i->fib6_nsiblings && fl6->flowi6_oif == 0) - f6i = fib6_multipath_select(net, f6i, fl6, - fl6->flowi6_oif, skb, - flags); - } + if (f6i == net->ipv6.fib6_null_entry) { fn = fib6_backtrack(fn, &fl6->saddr); if (fn) goto restart; - } - trace_fib6_table_lookup(net, f6i, table, fl6); + rt = net->ipv6.ip6_null_entry; + dst_hold(&rt->dst); + goto out; + } + if (f6i->fib6_nsiblings && fl6->flowi6_oif == 0) + f6i = fib6_multipath_select(net, f6i, fl6, fl6->flowi6_oif, skb, + flags); /* Search through exception table */ rt = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr); if (rt) { if (ip6_hold_safe(net, &rt)) dst_use_noref(&rt->dst, jiffies); - } else if (f6i == net->ipv6.fib6_null_entry) { - rt = net->ipv6.ip6_null_entry; - dst_hold(&rt->dst); } else { rt = ip6_create_rt_rcu(f6i); } +out: + trace_fib6_table_lookup(net, f6i, table, fl6); + rcu_read_unlock(); return rt; @@ -1841,9 +1855,6 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, rcu_read_lock(); f6i = fib6_table_lookup(net, table, oif, fl6, strict); - if (f6i->fib6_nsiblings) - f6i = fib6_multipath_select(net, f6i, fl6, oif, skb, strict); - if (f6i == net->ipv6.fib6_null_entry) { rt = net->ipv6.ip6_null_entry; rcu_read_unlock(); @@ -1851,6 +1862,9 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, return rt; } + if (f6i->fib6_nsiblings) + f6i = fib6_multipath_select(net, f6i, fl6, oif, skb, strict); + /*Search through exception table */ rt = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr); if (rt) { @@ -2393,6 +2407,35 @@ void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst, NULL); } +static bool ip6_redirect_nh_match(struct fib6_info *f6i, + struct fib6_nh *nh, + struct flowi6 *fl6, + const struct in6_addr *gw, + struct rt6_info **ret) +{ + if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family || + fl6->flowi6_oif != nh->fib_nh_dev->ifindex) + return false; + + /* rt_cache's gateway might be different from its 'parent' + * in the case of an ip redirect. + * So we keep searching in the exception table if the gateway + * is different. + */ + if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) { + struct rt6_info *rt_cache; + + rt_cache = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr); + if (rt_cache && + ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) { + *ret = rt_cache; + return true; + } + return false; + } + return true; +} + /* Handle redirects */ struct ip6rd_flowi { struct flowi6 fl6; @@ -2406,7 +2449,7 @@ static struct rt6_info *__ip6_route_redirect(struct net *net, int flags) { struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6; - struct rt6_info *ret = NULL, *rt_cache; + struct rt6_info *ret = NULL; struct fib6_info *rt; struct fib6_node *fn; @@ -2424,34 +2467,15 @@ static struct rt6_info *__ip6_route_redirect(struct net *net, fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); restart: for_each_fib6_node_rt_rcu(fn) { - if (rt->fib6_nh.fib_nh_flags & RTNH_F_DEAD) - continue; if (fib6_check_expired(rt)) continue; if (rt->fib6_flags & RTF_REJECT) break; - if (!rt->fib6_nh.fib_nh_gw_family) - continue; if (fl6->flowi6_oif != rt->fib6_nh.fib_nh_dev->ifindex) continue; - /* rt_cache's gateway might be different from its 'parent' - * in the case of an ip redirect. - * So we keep searching in the exception table if the gateway - * is different. - */ - if (!ipv6_addr_equal(&rdfl->gateway, &rt->fib6_nh.fib_nh_gw6)) { - rt_cache = rt6_find_cached_rt(rt, - &fl6->daddr, - &fl6->saddr); - if (rt_cache && - ipv6_addr_equal(&rdfl->gateway, - &rt_cache->rt6i_gateway)) { - ret = rt_cache; - break; - } - continue; - } - break; + if (ip6_redirect_nh_match(rt, &rt->fib6_nh, fl6, + &rdfl->gateway, &ret)) + goto out; } if (!rt) |