diff options
Diffstat (limited to 'net/ipv6/route.c')
-rw-r--r-- | net/ipv6/route.c | 430 |
1 files changed, 314 insertions, 116 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 0c889cb89cc3..1a1122a6bbf5 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -72,8 +72,7 @@ enum rt6_nud_state { RT6_NUD_SUCCEED = 1 }; -static struct rt6_info *ip6_rt_copy(struct rt6_info *ort, - const struct in6_addr *dest); +static void ip6_rt_copy_init(struct rt6_info *rt, struct rt6_info *ort); static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie); static unsigned int ip6_default_advmss(const struct dst_entry *dst); static unsigned int ip6_mtu(const struct dst_entry *dst); @@ -105,11 +104,79 @@ static struct rt6_info *rt6_get_route_info(struct net *net, const struct in6_addr *gwaddr, int ifindex); #endif +struct uncached_list { + spinlock_t lock; + struct list_head head; +}; + +static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list); + +static void rt6_uncached_list_add(struct rt6_info *rt) +{ + struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list); + + rt->dst.flags |= DST_NOCACHE; + rt->rt6i_uncached_list = ul; + + spin_lock_bh(&ul->lock); + list_add_tail(&rt->rt6i_uncached, &ul->head); + spin_unlock_bh(&ul->lock); +} + +static void rt6_uncached_list_del(struct rt6_info *rt) +{ + if (!list_empty(&rt->rt6i_uncached)) { + struct uncached_list *ul = rt->rt6i_uncached_list; + + spin_lock_bh(&ul->lock); + list_del(&rt->rt6i_uncached); + spin_unlock_bh(&ul->lock); + } +} + +static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev) +{ + struct net_device *loopback_dev = net->loopback_dev; + int cpu; + + for_each_possible_cpu(cpu) { + struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); + struct rt6_info *rt; + + spin_lock_bh(&ul->lock); + list_for_each_entry(rt, &ul->head, rt6i_uncached) { + struct inet6_dev *rt_idev = rt->rt6i_idev; + struct net_device *rt_dev = rt->dst.dev; + + if (rt_idev && (rt_idev->dev == dev || !dev) && + rt_idev->dev != loopback_dev) { + rt->rt6i_idev = in6_dev_get(loopback_dev); + in6_dev_put(rt_idev); + } + + if (rt_dev && (rt_dev == dev || !dev) && + rt_dev != loopback_dev) { + rt->dst.dev = loopback_dev; + dev_hold(rt->dst.dev); + dev_put(rt_dev); + } + } + spin_unlock_bh(&ul->lock); + } +} + +static u32 *rt6_pcpu_cow_metrics(struct rt6_info *rt) +{ + return dst_metrics_write_ptr(rt->dst.from); +} + static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old) { struct rt6_info *rt = (struct rt6_info *)dst; - if (rt->rt6i_flags & RTF_CACHE) + if (rt->rt6i_flags & RTF_PCPU) + return rt6_pcpu_cow_metrics(rt); + else if (rt->rt6i_flags & RTF_CACHE) return NULL; else return dst_cow_metrics_generic(dst, old); @@ -249,10 +316,10 @@ static const struct rt6_info ip6_blk_hole_entry_template = { #endif /* allocate dst with ip6_dst_ops */ -static inline struct rt6_info *ip6_dst_alloc(struct net *net, - struct net_device *dev, - int flags, - struct fib6_table *table) +static struct rt6_info *__ip6_dst_alloc(struct net *net, + struct net_device *dev, + int flags, + struct fib6_table *table) { struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev, 0, DST_OBSOLETE_FORCE_CHK, flags); @@ -262,18 +329,53 @@ static inline struct rt6_info *ip6_dst_alloc(struct net *net, memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst)); INIT_LIST_HEAD(&rt->rt6i_siblings); + INIT_LIST_HEAD(&rt->rt6i_uncached); } return rt; } +static struct rt6_info *ip6_dst_alloc(struct net *net, + struct net_device *dev, + int flags, + struct fib6_table *table) +{ + struct rt6_info *rt = __ip6_dst_alloc(net, dev, flags, table); + + if (rt) { + rt->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, GFP_ATOMIC); + if (rt->rt6i_pcpu) { + int cpu; + + for_each_possible_cpu(cpu) { + struct rt6_info **p; + + p = per_cpu_ptr(rt->rt6i_pcpu, cpu); + /* no one shares rt */ + *p = NULL; + } + } else { + dst_destroy((struct dst_entry *)rt); + return NULL; + } + } + + return rt; +} + static void ip6_dst_destroy(struct dst_entry *dst) { struct rt6_info *rt = (struct rt6_info *)dst; - struct inet6_dev *idev = rt->rt6i_idev; struct dst_entry *from = dst->from; + struct inet6_dev *idev; dst_destroy_metrics_generic(dst); + if (rt->rt6i_pcpu) + free_percpu(rt->rt6i_pcpu); + + rt6_uncached_list_del(rt); + + idev = rt->rt6i_idev; if (idev) { rt->rt6i_idev = NULL; in6_dev_put(idev); @@ -655,6 +757,11 @@ static struct rt6_info *rt6_select(struct fib6_node *fn, int oif, int strict) return match ? match : net->ipv6.ip6_null_entry; } +static bool rt6_is_gw_or_nonexthop(const struct rt6_info *rt) +{ + return (rt->rt6i_flags & (RTF_NONEXTHOP | RTF_GATEWAY)); +} + #ifdef CONFIG_IPV6_ROUTE_INFO int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, const struct in6_addr *gwaddr) @@ -833,9 +940,9 @@ int ip6_ins_rt(struct rt6_info *rt) return __ip6_ins_rt(rt, &info, &mxc); } -static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, - const struct in6_addr *daddr, - const struct in6_addr *saddr) +static struct rt6_info *ip6_rt_cache_alloc(struct rt6_info *ort, + const struct in6_addr *daddr, + const struct in6_addr *saddr) { struct rt6_info *rt; @@ -843,15 +950,26 @@ static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, * Clone the route. */ - rt = ip6_rt_copy(ort, daddr); + if (ort->rt6i_flags & (RTF_CACHE | RTF_PCPU)) + ort = (struct rt6_info *)ort->dst.from; - if (rt) { + rt = __ip6_dst_alloc(dev_net(ort->dst.dev), ort->dst.dev, + 0, ort->rt6i_table); + + if (!rt) + return NULL; + + ip6_rt_copy_init(rt, ort); + rt->rt6i_flags |= RTF_CACHE; + rt->rt6i_metric = 0; + rt->dst.flags |= DST_HOST; + rt->rt6i_dst.addr = *daddr; + rt->rt6i_dst.plen = 128; + + if (!rt6_is_gw_or_nonexthop(ort)) { if (ort->rt6i_dst.plen != 128 && ipv6_addr_equal(&ort->rt6i_dst.addr, daddr)) rt->rt6i_flags |= RTF_ANYCAST; - - rt->rt6i_flags |= RTF_CACHE; - #ifdef CONFIG_IPV6_SUBTREES if (rt->rt6i_src.plen && saddr) { rt->rt6i_src.addr = *saddr; @@ -863,30 +981,65 @@ static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, return rt; } -static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort, - const struct in6_addr *daddr) +static struct rt6_info *ip6_rt_pcpu_alloc(struct rt6_info *rt) { - struct rt6_info *rt = ip6_rt_copy(ort, daddr); + struct rt6_info *pcpu_rt; - if (rt) - rt->rt6i_flags |= RTF_CACHE; - return rt; + pcpu_rt = __ip6_dst_alloc(dev_net(rt->dst.dev), + rt->dst.dev, rt->dst.flags, + rt->rt6i_table); + + if (!pcpu_rt) + return NULL; + ip6_rt_copy_init(pcpu_rt, rt); + pcpu_rt->rt6i_protocol = rt->rt6i_protocol; + pcpu_rt->rt6i_flags |= RTF_PCPU; + return pcpu_rt; +} + +/* It should be called with read_lock_bh(&tb6_lock) acquired */ +static struct rt6_info *rt6_get_pcpu_route(struct rt6_info *rt) +{ + struct rt6_info *pcpu_rt, *prev, **p; + + p = this_cpu_ptr(rt->rt6i_pcpu); + pcpu_rt = *p; + + if (pcpu_rt) + goto done; + + pcpu_rt = ip6_rt_pcpu_alloc(rt); + if (!pcpu_rt) { + struct net *net = dev_net(rt->dst.dev); + + pcpu_rt = net->ipv6.ip6_null_entry; + goto done; + } + + prev = cmpxchg(p, NULL, pcpu_rt); + if (prev) { + /* If someone did it before us, return prev instead */ + dst_destroy(&pcpu_rt->dst); + pcpu_rt = prev; + } + +done: + dst_hold(&pcpu_rt->dst); + rt6_dst_from_metrics_check(pcpu_rt); + return pcpu_rt; } static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, int oif, struct flowi6 *fl6, int flags) { struct fib6_node *fn, *saved_fn; - struct rt6_info *rt, *nrt; + struct rt6_info *rt; int strict = 0; - int attempts = 3; - int err; strict |= flags & RT6_LOOKUP_F_IFACE; if (net->ipv6.devconf_all->forwarding == 0) strict |= RT6_LOOKUP_F_REACHABLE; -redo_fib6_lookup_lock: read_lock_bh(&table->tb6_lock); fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); @@ -905,52 +1058,52 @@ redo_rt6_select: strict &= ~RT6_LOOKUP_F_REACHABLE; fn = saved_fn; goto redo_rt6_select; - } else { - dst_hold(&rt->dst); - read_unlock_bh(&table->tb6_lock); - goto out2; } } - dst_hold(&rt->dst); - read_unlock_bh(&table->tb6_lock); - if (rt->rt6i_flags & RTF_CACHE) - goto out2; + if (rt == net->ipv6.ip6_null_entry || (rt->rt6i_flags & RTF_CACHE)) { + dst_use(&rt->dst, jiffies); + read_unlock_bh(&table->tb6_lock); - if (!(rt->rt6i_flags & (RTF_NONEXTHOP | RTF_GATEWAY))) - nrt = rt6_alloc_cow(rt, &fl6->daddr, &fl6->saddr); - else if (!(rt->dst.flags & DST_HOST) || !(rt->rt6i_flags & RTF_LOCAL)) - nrt = rt6_alloc_clone(rt, &fl6->daddr); - else - goto out2; + rt6_dst_from_metrics_check(rt); + return rt; + } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) && + !(rt->rt6i_flags & RTF_GATEWAY))) { + /* Create a RTF_CACHE clone which will not be + * owned by the fib6 tree. It is for the special case where + * the daddr in the skb during the neighbor look-up is different + * from the fl6->daddr used to look-up route here. + */ - ip6_rt_put(rt); - rt = nrt ? : net->ipv6.ip6_null_entry; + struct rt6_info *uncached_rt; - dst_hold(&rt->dst); - if (nrt) { - err = ip6_ins_rt(nrt); - if (!err) - goto out2; - } + dst_use(&rt->dst, jiffies); + read_unlock_bh(&table->tb6_lock); - if (--attempts <= 0) - goto out2; + uncached_rt = ip6_rt_cache_alloc(rt, &fl6->daddr, NULL); + dst_release(&rt->dst); - /* - * Race condition! In the gap, when table->tb6_lock was - * released someone could insert this route. Relookup. - */ - ip6_rt_put(rt); - goto redo_fib6_lookup_lock; + if (uncached_rt) + rt6_uncached_list_add(uncached_rt); + else + uncached_rt = net->ipv6.ip6_null_entry; -out2: - rt6_dst_from_metrics_check(rt); - rt->dst.lastuse = jiffies; - rt->dst.__use++; + dst_hold(&uncached_rt->dst); + return uncached_rt; - return rt; + } else { + /* Get a percpu copy */ + + struct rt6_info *pcpu_rt; + + rt->dst.lastuse = jiffies; + rt->dst.__use++; + pcpu_rt = rt6_get_pcpu_route(rt); + read_unlock_bh(&table->tb6_lock); + + return pcpu_rt; + } } static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *table, @@ -1061,6 +1214,26 @@ static void rt6_dst_from_metrics_check(struct rt6_info *rt) dst_init_metrics(&rt->dst, dst_metrics_ptr(rt->dst.from), true); } +static struct dst_entry *rt6_check(struct rt6_info *rt, u32 cookie) +{ + if (!rt->rt6i_node || (rt->rt6i_node->fn_sernum != cookie)) + return NULL; + + if (rt6_check_expired(rt)) + return NULL; + + return &rt->dst; +} + +static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt, u32 cookie) +{ + if (rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && + rt6_check((struct rt6_info *)(rt->dst.from), cookie)) + return &rt->dst; + else + return NULL; +} + static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie) { struct rt6_info *rt; @@ -1071,15 +1244,13 @@ static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie) * DST_OBSOLETE_FORCE_CHK which forces validation calls down * into this function always. */ - if (!rt->rt6i_node || (rt->rt6i_node->fn_sernum != cookie)) - return NULL; - - if (rt6_check_expired(rt)) - return NULL; rt6_dst_from_metrics_check(rt); - return dst; + if ((rt->rt6i_flags & RTF_PCPU) || unlikely(dst->flags & DST_NOCACHE)) + return rt6_dst_from_check(rt, cookie); + else + return rt6_check(rt, cookie); } static struct dst_entry *ip6_negative_advice(struct dst_entry *dst) @@ -1118,24 +1289,63 @@ static void ip6_link_failure(struct sk_buff *skb) } } -static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, - struct sk_buff *skb, u32 mtu) +static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu) +{ + struct net *net = dev_net(rt->dst.dev); + + rt->rt6i_flags |= RTF_MODIFIED; + rt->rt6i_pmtu = mtu; + rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires); +} + +static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk, + const struct ipv6hdr *iph, u32 mtu) { struct rt6_info *rt6 = (struct rt6_info *)dst; - dst_confirm(dst); - if (mtu < dst_mtu(dst) && (rt6->rt6i_flags & RTF_CACHE)) { - struct net *net = dev_net(dst->dev); + if (rt6->rt6i_flags & RTF_LOCAL) + return; - rt6->rt6i_flags |= RTF_MODIFIED; - if (mtu < IPV6_MIN_MTU) - mtu = IPV6_MIN_MTU; + dst_confirm(dst); + mtu = max_t(u32, mtu, IPV6_MIN_MTU); + if (mtu >= dst_mtu(dst)) + return; - rt6->rt6i_pmtu = mtu; - rt6_update_expires(rt6, net->ipv6.sysctl.ip6_rt_mtu_expires); + if (rt6->rt6i_flags & RTF_CACHE) { + rt6_do_update_pmtu(rt6, mtu); + } else { + const struct in6_addr *daddr, *saddr; + struct rt6_info *nrt6; + + if (iph) { + daddr = &iph->daddr; + saddr = &iph->saddr; + } else if (sk) { + daddr = &sk->sk_v6_daddr; + saddr = &inet6_sk(sk)->saddr; + } else { + return; + } + nrt6 = ip6_rt_cache_alloc(rt6, daddr, saddr); + if (nrt6) { + rt6_do_update_pmtu(nrt6, mtu); + + /* ip6_ins_rt(nrt6) will bump the + * rt6->rt6i_node->fn_sernum + * which will fail the next rt6_check() and + * invalidate the sk->sk_dst_cache. + */ + ip6_ins_rt(nrt6); + } } } +static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb, u32 mtu) +{ + __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu); +} + void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif, u32 mark) { @@ -1152,7 +1362,7 @@ void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, dst = ip6_route_output(net, NULL, &fl6); if (!dst->error) - ip6_rt_update_pmtu(dst, NULL, skb, ntohl(mtu)); + __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu)); dst_release(dst); } EXPORT_SYMBOL_GPL(ip6_update_pmtu); @@ -1879,7 +2089,7 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu NEIGH_UPDATE_F_ISROUTER)) ); - nrt = ip6_rt_copy(rt, &msg->dest); + nrt = ip6_rt_cache_alloc(rt, &msg->dest, NULL); if (!nrt) goto out; @@ -1921,46 +2131,25 @@ static void rt6_set_from(struct rt6_info *rt, struct rt6_info *from) dst_init_metrics(&rt->dst, dst_metrics_ptr(&from->dst), true); } -static struct rt6_info *ip6_rt_copy(struct rt6_info *ort, - const struct in6_addr *dest) +static void ip6_rt_copy_init(struct rt6_info *rt, struct rt6_info *ort) { - struct net *net = dev_net(ort->dst.dev); - struct rt6_info *rt; - - if (ort->rt6i_flags & RTF_CACHE) - ort = (struct rt6_info *)ort->dst.from; - - rt = ip6_dst_alloc(net, ort->dst.dev, 0, - ort->rt6i_table); - - if (rt) { - rt->dst.input = ort->dst.input; - rt->dst.output = ort->dst.output; - rt->dst.flags |= DST_HOST; - - rt->rt6i_dst.addr = *dest; - rt->rt6i_dst.plen = 128; - rt->dst.error = ort->dst.error; - rt->rt6i_idev = ort->rt6i_idev; - if (rt->rt6i_idev) - in6_dev_hold(rt->rt6i_idev); - rt->dst.lastuse = jiffies; - - if (ort->rt6i_flags & RTF_GATEWAY) - rt->rt6i_gateway = ort->rt6i_gateway; - else - rt->rt6i_gateway = *dest; - rt->rt6i_flags = ort->rt6i_flags; - rt6_set_from(rt, ort); - rt->rt6i_metric = 0; - + rt->dst.input = ort->dst.input; + rt->dst.output = ort->dst.output; + rt->rt6i_dst = ort->rt6i_dst; + rt->dst.error = ort->dst.error; + rt->rt6i_idev = ort->rt6i_idev; + if (rt->rt6i_idev) + in6_dev_hold(rt->rt6i_idev); + rt->dst.lastuse = jiffies; + rt->rt6i_gateway = ort->rt6i_gateway; + rt->rt6i_flags = ort->rt6i_flags; + rt6_set_from(rt, ort); + rt->rt6i_metric = ort->rt6i_metric; #ifdef CONFIG_IPV6_SUBTREES - memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key)); + rt->rt6i_src = ort->rt6i_src; #endif - memcpy(&rt->rt6i_prefsrc, &ort->rt6i_prefsrc, sizeof(struct rt6key)); - rt->rt6i_table = ort->rt6i_table; - } - return rt; + rt->rt6i_prefsrc = ort->rt6i_prefsrc; + rt->rt6i_table = ort->rt6i_table; } #ifdef CONFIG_IPV6_ROUTE_INFO @@ -2335,6 +2524,7 @@ void rt6_ifdown(struct net *net, struct net_device *dev) fib6_clean_all(net, fib6_ifdown, &adn); icmp6_clean_all(fib6_ifdown, &adn); + rt6_uncached_list_flush_dev(net, dev); } struct rt6_mtu_change_arg { @@ -3231,6 +3421,7 @@ static struct notifier_block ip6_route_dev_notifier = { int __init ip6_route_init(void) { int ret; + int cpu; ret = -ENOMEM; ip6_dst_ops_template.kmem_cachep = @@ -3290,6 +3481,13 @@ int __init ip6_route_init(void) if (ret) goto out_register_late_subsys; + for_each_possible_cpu(cpu) { + struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); + + INIT_LIST_HEAD(&ul->head); + spin_lock_init(&ul->lock); + } + out: return ret; |