diff options
Diffstat (limited to 'net/ipv4/route.c')
-rw-r--r-- | net/ipv4/route.c | 307 |
1 files changed, 173 insertions, 134 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 3f7bb7185c50..ff622069fcef 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -70,7 +70,6 @@ #include <linux/types.h> #include <linux/kernel.h> #include <linux/mm.h> -#include <linux/bootmem.h> #include <linux/string.h> #include <linux/socket.h> #include <linux/sockios.h> @@ -80,7 +79,6 @@ #include <linux/netdevice.h> #include <linux/proc_fs.h> #include <linux/init.h> -#include <linux/workqueue.h> #include <linux/skbuff.h> #include <linux/inetdevice.h> #include <linux/igmp.h> @@ -88,11 +86,9 @@ #include <linux/mroute.h> #include <linux/netfilter_ipv4.h> #include <linux/random.h> -#include <linux/jhash.h> #include <linux/rcupdate.h> #include <linux/times.h> #include <linux/slab.h> -#include <linux/prefetch.h> #include <net/dst.h> #include <net/net_namespace.h> #include <net/protocol.h> @@ -147,6 +143,7 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb, u32 mtu); static void ip_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb); +static void ipv4_dst_destroy(struct dst_entry *dst); static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int how) @@ -170,6 +167,7 @@ static struct dst_ops ipv4_dst_ops = { .default_advmss = ipv4_default_advmss, .mtu = ipv4_mtu, .cow_metrics = ipv4_cow_metrics, + .destroy = ipv4_dst_destroy, .ifdown = ipv4_dst_ifdown, .negative_advice = ipv4_negative_advice, .link_failure = ipv4_link_failure, @@ -204,11 +202,6 @@ EXPORT_SYMBOL(ip_tos2prio); static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat); #define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field) -static inline int rt_genid(struct net *net) -{ - return atomic_read(&net->ipv4.rt_genid); -} - #ifdef CONFIG_PROC_FS static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos) { @@ -449,27 +442,9 @@ static inline bool rt_is_expired(const struct rtable *rth) return rth->rt_genid != rt_genid(dev_net(rth->dst.dev)); } -/* - * Perturbation of rt_genid by a small quantity [1..256] - * Using 8 bits of shuffling ensure we can call rt_cache_invalidate() - * many times (2^24) without giving recent rt_genid. - * Jenkins hash is strong enough that litle changes of rt_genid are OK. - */ -static void rt_cache_invalidate(struct net *net) -{ - unsigned char shuffle; - - get_random_bytes(&shuffle, sizeof(shuffle)); - atomic_add(shuffle + 1U, &net->ipv4.rt_genid); -} - -/* - * delay < 0 : invalidate cache (fast : entries will be deleted later) - * delay >= 0 : invalidate & flush cache (can be long) - */ -void rt_cache_flush(struct net *net, int delay) +void rt_cache_flush(struct net *net) { - rt_cache_invalidate(net); + rt_genid_bump(net); } static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst, @@ -587,11 +562,17 @@ static void ip_rt_build_flow_key(struct flowi4 *fl4, const struct sock *sk, build_sk_flow_key(fl4, sk); } -static DEFINE_SEQLOCK(fnhe_seqlock); +static inline void rt_free(struct rtable *rt) +{ + call_rcu(&rt->dst.rcu_head, dst_rcu_free); +} + +static DEFINE_SPINLOCK(fnhe_lock); static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) { struct fib_nh_exception *fnhe, *oldest; + struct rtable *orig; oldest = rcu_dereference(hash->chain); for (fnhe = rcu_dereference(oldest->fnhe_next); fnhe; @@ -599,6 +580,11 @@ static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash) if (time_before(fnhe->fnhe_stamp, oldest->fnhe_stamp)) oldest = fnhe; } + orig = rcu_dereference(oldest->fnhe_rth); + if (orig) { + RCU_INIT_POINTER(oldest->fnhe_rth, NULL); + rt_free(orig); + } return oldest; } @@ -620,7 +606,7 @@ static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, int depth; u32 hval = fnhe_hashfun(daddr); - write_seqlock_bh(&fnhe_seqlock); + spin_lock_bh(&fnhe_lock); hash = nh->nh_exceptions; if (!hash) { @@ -667,7 +653,7 @@ static void update_or_create_fnhe(struct fib_nh *nh, __be32 daddr, __be32 gw, fnhe->fnhe_stamp = jiffies; out_unlock: - write_sequnlock_bh(&fnhe_seqlock); + spin_unlock_bh(&fnhe_lock); return; } @@ -925,12 +911,14 @@ static u32 __ip_rt_update_pmtu(struct rtable *rt, struct flowi4 *fl4, u32 mtu) if (mtu < ip_rt_min_pmtu) mtu = ip_rt_min_pmtu; + rcu_read_lock(); if (fib_lookup(dev_net(rt->dst.dev), fl4, &res) == 0) { struct fib_nh *nh = &FIB_RES_NH(res); update_or_create_fnhe(nh, fl4->daddr, 0, mtu, jiffies + ip_rt_mtu_expires); } + rcu_read_unlock(); return mtu; } @@ -947,7 +935,7 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, dst->obsolete = DST_OBSOLETE_KILL; } else { rt->rt_pmtu = mtu; - dst_set_expires(&rt->dst, ip_rt_mtu_expires); + rt->dst.expires = max(1UL, jiffies + ip_rt_mtu_expires); } } @@ -1123,10 +1111,7 @@ static unsigned int ipv4_mtu(const struct dst_entry *dst) const struct rtable *rt = (const struct rtable *) dst; unsigned int mtu = rt->rt_pmtu; - if (mtu && time_after_eq(jiffies, rt->dst.expires)) - mtu = 0; - - if (!mtu) + if (!mtu || time_after_eq(jiffies, rt->dst.expires)) mtu = dst_metric_raw(dst, RTAX_MTU); if (mtu && rt_is_output_route(rt)) @@ -1164,61 +1149,118 @@ static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr) return NULL; } -static void rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, +static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe, __be32 daddr) { - __be32 fnhe_daddr, gw; - unsigned long expires; - unsigned int seq; - u32 pmtu; - -restart: - seq = read_seqbegin(&fnhe_seqlock); - fnhe_daddr = fnhe->fnhe_daddr; - gw = fnhe->fnhe_gw; - pmtu = fnhe->fnhe_pmtu; - expires = fnhe->fnhe_expires; - if (read_seqretry(&fnhe_seqlock, seq)) - goto restart; - - if (daddr != fnhe_daddr) - return; + bool ret = false; + + spin_lock_bh(&fnhe_lock); - if (pmtu) { - unsigned long diff = expires - jiffies; + if (daddr == fnhe->fnhe_daddr) { + struct rtable *orig; - if (time_before(jiffies, expires)) { - rt->rt_pmtu = pmtu; - dst_set_expires(&rt->dst, diff); + if (fnhe->fnhe_pmtu) { + unsigned long expires = fnhe->fnhe_expires; + unsigned long diff = expires - jiffies; + + if (time_before(jiffies, expires)) { + rt->rt_pmtu = fnhe->fnhe_pmtu; + dst_set_expires(&rt->dst, diff); + } } + if (fnhe->fnhe_gw) { + rt->rt_flags |= RTCF_REDIRECTED; + rt->rt_gateway = fnhe->fnhe_gw; + } + + orig = rcu_dereference(fnhe->fnhe_rth); + rcu_assign_pointer(fnhe->fnhe_rth, rt); + if (orig) + rt_free(orig); + + fnhe->fnhe_stamp = jiffies; + ret = true; + } else { + /* Routes we intend to cache in nexthop exception have + * the DST_NOCACHE bit clear. However, if we are + * unsuccessful at storing this route into the cache + * we really need to set it. + */ + rt->dst.flags |= DST_NOCACHE; } - if (gw) { - rt->rt_flags |= RTCF_REDIRECTED; - rt->rt_gateway = gw; - } - fnhe->fnhe_stamp = jiffies; -} + spin_unlock_bh(&fnhe_lock); -static inline void rt_release_rcu(struct rcu_head *head) -{ - struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head); - dst_release(dst); + return ret; } -static void rt_cache_route(struct fib_nh *nh, struct rtable *rt) +static bool rt_cache_route(struct fib_nh *nh, struct rtable *rt) { - struct rtable *orig, *prev, **p = &nh->nh_rth_output; - - if (rt_is_input_route(rt)) - p = &nh->nh_rth_input; + struct rtable *orig, *prev, **p; + bool ret = true; + if (rt_is_input_route(rt)) { + p = (struct rtable **)&nh->nh_rth_input; + } else { + if (!nh->nh_pcpu_rth_output) + goto nocache; + p = (struct rtable **)__this_cpu_ptr(nh->nh_pcpu_rth_output); + } orig = *p; prev = cmpxchg(p, orig, rt); if (prev == orig) { - dst_clone(&rt->dst); if (orig) - call_rcu_bh(&orig->dst.rcu_head, rt_release_rcu); + rt_free(orig); + } else { + /* Routes we intend to cache in the FIB nexthop have + * the DST_NOCACHE bit clear. However, if we are + * unsuccessful at storing this route into the cache + * we really need to set it. + */ +nocache: + rt->dst.flags |= DST_NOCACHE; + ret = false; + } + + return ret; +} + +static DEFINE_SPINLOCK(rt_uncached_lock); +static LIST_HEAD(rt_uncached_list); + +static void rt_add_uncached_list(struct rtable *rt) +{ + spin_lock_bh(&rt_uncached_lock); + list_add_tail(&rt->rt_uncached, &rt_uncached_list); + spin_unlock_bh(&rt_uncached_lock); +} + +static void ipv4_dst_destroy(struct dst_entry *dst) +{ + struct rtable *rt = (struct rtable *) dst; + + if (!list_empty(&rt->rt_uncached)) { + spin_lock_bh(&rt_uncached_lock); + list_del(&rt->rt_uncached); + spin_unlock_bh(&rt_uncached_lock); + } +} + +void rt_flush_dev(struct net_device *dev) +{ + if (!list_empty(&rt_uncached_list)) { + struct net *net = dev_net(dev); + struct rtable *rt; + + spin_lock_bh(&rt_uncached_lock); + list_for_each_entry(rt, &rt_uncached_list, rt_uncached) { + if (rt->dst.dev != dev) + continue; + rt->dst.dev = net->loopback_dev; + dev_hold(rt->dst.dev); + dev_put(dev); + } + spin_unlock_bh(&rt_uncached_lock); } } @@ -1234,20 +1276,24 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr, struct fib_nh_exception *fnhe, struct fib_info *fi, u16 type, u32 itag) { + bool cached = false; + if (fi) { struct fib_nh *nh = &FIB_RES_NH(*res); if (nh->nh_gw && nh->nh_scope == RT_SCOPE_LINK) rt->rt_gateway = nh->nh_gw; - if (unlikely(fnhe)) - rt_bind_exception(rt, fnhe, daddr); dst_init_metrics(&rt->dst, fi->fib_metrics, true); #ifdef CONFIG_IP_ROUTE_CLASSID rt->dst.tclassid = nh->nh_tclassid; #endif - if (!(rt->dst.flags & DST_HOST)) - rt_cache_route(nh, rt); + if (unlikely(fnhe)) + cached = rt_bind_exception(rt, fnhe, daddr); + else if (!(rt->dst.flags & DST_NOCACHE)) + cached = rt_cache_route(nh, rt); } + if (unlikely(!cached)) + rt_add_uncached_list(rt); #ifdef CONFIG_IP_ROUTE_CLASSID #ifdef CONFIG_IP_MULTIPLE_TABLES @@ -1261,7 +1307,7 @@ static struct rtable *rt_dst_alloc(struct net_device *dev, bool nopolicy, bool noxfrm, bool will_cache) { return dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK, - (will_cache ? 0 : DST_HOST) | DST_NOCACHE | + (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) | (nopolicy ? DST_NOPOLICY : 0) | (noxfrm ? DST_NOXFRM : 0)); } @@ -1314,6 +1360,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, rth->rt_iif = 0; rth->rt_pmtu = 0; rth->rt_gateway = 0; + INIT_LIST_HEAD(&rth->rt_uncached); if (our) { rth->dst.input= ip_local_deliver; rth->rt_flags |= RTCF_LOCAL; @@ -1366,8 +1413,7 @@ static void ip_handle_martian_source(struct net_device *dev, static int __mkroute_input(struct sk_buff *skb, const struct fib_result *res, struct in_device *in_dev, - __be32 daddr, __be32 saddr, u32 tos, - struct rtable **result) + __be32 daddr, __be32 saddr, u32 tos) { struct rtable *rth; int err; @@ -1416,9 +1462,9 @@ static int __mkroute_input(struct sk_buff *skb, do_cache = false; if (res->fi) { if (!itag) { - rth = FIB_RES_NH(*res).nh_rth_input; + rth = rcu_dereference(FIB_RES_NH(*res).nh_rth_input); if (rt_cache_valid(rth)) { - dst_hold(&rth->dst); + skb_dst_set_noref(skb, &rth->dst); goto out; } do_cache = true; @@ -1440,13 +1486,14 @@ static int __mkroute_input(struct sk_buff *skb, rth->rt_iif = 0; rth->rt_pmtu = 0; rth->rt_gateway = 0; + INIT_LIST_HEAD(&rth->rt_uncached); rth->dst.input = ip_forward; rth->dst.output = ip_output; rt_set_nexthop(rth, daddr, res, NULL, res->fi, res->type, itag); + skb_dst_set(skb, &rth->dst); out: - *result = rth; err = 0; cleanup: return err; @@ -1458,21 +1505,13 @@ static int ip_mkroute_input(struct sk_buff *skb, struct in_device *in_dev, __be32 daddr, __be32 saddr, u32 tos) { - struct rtable *rth = NULL; - int err; - #ifdef CONFIG_IP_ROUTE_MULTIPATH if (res->fi && res->fi->fib_nhs > 1) fib_select_multipath(res); #endif /* create a routing cache entry */ - err = __mkroute_input(skb, res, in_dev, daddr, saddr, tos, &rth); - if (err) - return err; - - skb_dst_set(skb, &rth->dst); - return 0; + return __mkroute_input(skb, res, in_dev, daddr, saddr, tos); } /* @@ -1524,11 +1563,14 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, if (ipv4_is_zeronet(daddr)) goto martian_destination; - if (likely(!IN_DEV_ROUTE_LOCALNET(in_dev))) { - if (ipv4_is_loopback(daddr)) + /* Following code try to avoid calling IN_DEV_NET_ROUTE_LOCALNET(), + * and call it once if daddr or/and saddr are loopback addresses + */ + if (ipv4_is_loopback(daddr)) { + if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) goto martian_destination; - - if (ipv4_is_loopback(saddr)) + } else if (ipv4_is_loopback(saddr)) { + if (!IN_DEV_NET_ROUTE_LOCALNET(in_dev, net)) goto martian_source; } @@ -1553,7 +1595,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, if (res.type == RTN_LOCAL) { err = fib_validate_source(skb, saddr, daddr, tos, - net->loopback_dev->ifindex, + LOOPBACK_IFINDEX, dev, in_dev, &itag); if (err < 0) goto martian_source_keep_err; @@ -1586,10 +1628,11 @@ local_input: do_cache = false; if (res.fi) { if (!itag) { - rth = FIB_RES_NH(res).nh_rth_input; + rth = rcu_dereference(FIB_RES_NH(res).nh_rth_input); if (rt_cache_valid(rth)) { - dst_hold(&rth->dst); - goto set_and_out; + skb_dst_set_noref(skb, &rth->dst); + err = 0; + goto out; } do_cache = true; } @@ -1613,6 +1656,7 @@ local_input: rth->rt_iif = 0; rth->rt_pmtu = 0; rth->rt_gateway = 0; + INIT_LIST_HEAD(&rth->rt_uncached); if (res.type == RTN_UNREACHABLE) { rth->dst.input= ip_error; rth->dst.error= -err; @@ -1620,7 +1664,6 @@ local_input: } if (do_cache) rt_cache_route(&FIB_RES_NH(res), rth); -set_and_out: skb_dst_set(skb, &rth->dst); err = 0; goto out; @@ -1658,8 +1701,8 @@ martian_source_keep_err: goto out; } -int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr, - u8 tos, struct net_device *dev) +int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr, + u8 tos, struct net_device *dev) { int res; @@ -1702,7 +1745,7 @@ int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr, rcu_read_unlock(); return res; } -EXPORT_SYMBOL(ip_route_input); +EXPORT_SYMBOL(ip_route_input_noref); /* called with rcu_read_lock() */ static struct rtable *__mkroute_output(const struct fib_result *res, @@ -1752,19 +1795,23 @@ static struct rtable *__mkroute_output(const struct fib_result *res, fnhe = NULL; if (fi) { + struct rtable __rcu **prth; + fnhe = find_exception(&FIB_RES_NH(*res), fl4->daddr); - if (!fnhe) { - rth = FIB_RES_NH(*res).nh_rth_output; - if (rt_cache_valid(rth)) { - dst_hold(&rth->dst); - return rth; - } + if (fnhe) + prth = &fnhe->fnhe_rth; + else + prth = __this_cpu_ptr(FIB_RES_NH(*res).nh_pcpu_rth_output); + rth = rcu_dereference(*prth); + if (rt_cache_valid(rth)) { + dst_hold(&rth->dst); + return rth; } } rth = rt_dst_alloc(dev_out, IN_DEV_CONF_GET(in_dev, NOPOLICY), IN_DEV_CONF_GET(in_dev, NOXFRM), - fi && !fnhe); + fi); if (!rth) return ERR_PTR(-ENOBUFS); @@ -1777,6 +1824,7 @@ static struct rtable *__mkroute_output(const struct fib_result *res, rth->rt_iif = orig_oif ? : 0; rth->rt_pmtu = 0; rth->rt_gateway = 0; + INIT_LIST_HEAD(&rth->rt_uncached); RT_CACHE_STAT_INC(out_slow_tot); @@ -1823,7 +1871,7 @@ struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) orig_oif = fl4->flowi4_oif; - fl4->flowi4_iif = net->loopback_dev->ifindex; + fl4->flowi4_iif = LOOPBACK_IFINDEX; fl4->flowi4_tos = tos & IPTOS_RT_MASK; fl4->flowi4_scope = ((tos & RTO_ONLINK) ? RT_SCOPE_LINK : RT_SCOPE_UNIVERSE); @@ -1912,7 +1960,7 @@ struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) if (!fl4->daddr) fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK); dev_out = net->loopback_dev; - fl4->flowi4_oif = net->loopback_dev->ifindex; + fl4->flowi4_oif = LOOPBACK_IFINDEX; res.type = RTN_LOCAL; flags |= RTCF_LOCAL; goto make_route; @@ -1959,7 +2007,6 @@ struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4) } dev_out = net->loopback_dev; fl4->flowi4_oif = dev_out->ifindex; - res.fi = NULL; flags |= RTCF_LOCAL; goto make_route; } @@ -2056,6 +2103,8 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or rt->rt_type = ort->rt_type; rt->rt_gateway = ort->rt_gateway; + INIT_LIST_HEAD(&rt->rt_uncached); + dst_free(new); } @@ -2082,7 +2131,7 @@ struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, EXPORT_SYMBOL_GPL(ip_route_output_flow); static int rt_fill_info(struct net *net, __be32 dst, __be32 src, - struct flowi4 *fl4, struct sk_buff *skb, u32 pid, + struct flowi4 *fl4, struct sk_buff *skb, u32 portid, u32 seq, int event, int nowait, unsigned int flags) { struct rtable *rt = skb_rtable(skb); @@ -2092,7 +2141,7 @@ static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 error; u32 metrics[RTAX_MAX]; - nlh = nlmsg_put(skb, pid, seq, event, sizeof(*r), flags); + nlh = nlmsg_put(skb, portid, seq, event, sizeof(*r), flags); if (nlh == NULL) return -EMSGSIZE; @@ -2252,12 +2301,12 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, void rt->rt_flags |= RTCF_NOTIFY; err = rt_fill_info(net, dst, src, &fl4, skb, - NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, + NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, RTM_NEWROUTE, 0, 0); if (err <= 0) goto errout_free; - err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).pid); + err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); errout: return err; @@ -2273,7 +2322,7 @@ int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb) void ip_rt_multicast_event(struct in_device *in_dev) { - rt_cache_flush(dev_net(in_dev->dev), 0); + rt_cache_flush(dev_net(in_dev->dev)); } #ifdef CONFIG_SYSCTL @@ -2282,16 +2331,7 @@ static int ipv4_sysctl_rtcache_flush(ctl_table *__ctl, int write, size_t *lenp, loff_t *ppos) { if (write) { - int flush_delay; - ctl_table ctl; - struct net *net; - - memcpy(&ctl, __ctl, sizeof(ctl)); - ctl.data = &flush_delay; - proc_dointvec(&ctl, write, buffer, lenp, ppos); - - net = (struct net *)__ctl->extra1; - rt_cache_flush(net, flush_delay); + rt_cache_flush((struct net *)__ctl->extra1); return 0; } @@ -2461,8 +2501,7 @@ static __net_initdata struct pernet_operations sysctl_route_ops = { static __net_init int rt_genid_init(struct net *net) { - get_random_bytes(&net->ipv4.rt_genid, - sizeof(net->ipv4.rt_genid)); + atomic_set(&net->rt_genid, 0); get_random_bytes(&net->ipv4.dev_addr_genid, sizeof(net->ipv4.dev_addr_genid)); return 0; |