From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gao feng Subject: [PATCH v6] ipv6: fix problem with expired dst cache Date: Fri, 6 Apr 2012 18:13:10 +0800 Message-ID: <1333707190-14075-1-git-send-email-gaofeng@cn.fujitsu.com> References: <1330064404-24763-1-git-send-email-gaofeng@cn.fujitsu.com> Cc: davem@davemloft.net, Gao feng To: netdev@vger.kernel.org Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:18681 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755926Ab2DFKNL (ORCPT ); Fri, 6 Apr 2012 06:13:11 -0400 In-Reply-To: <1330064404-24763-1-git-send-email-gaofeng@cn.fujitsu.com> Sender: netdev-owner@vger.kernel.org List-ID: If the ipv6 dst cache which copy from the dst generated by ICMPV6 RA packet. this dst cache will not check expire because it has no RTF_EXPIRES flag. So this dst cache will always be used until the dst gc run. Change the struct dst_entry,add a union contains new pointer from and expires. When rt6_info.rt6i_flags has no RTF_EXPIRES flag,the dst.expires has no use. we can use this field to point to where the dst cache copy from. The dst.from is only used in IPV6. rt6_check_expired check if rt6_info.dst.from is expired. ip6_rt_copy only set dst.from when the ort has flag RTF_ADDRCONF and RTF_DEFAULT.then hold the ort. ip6_dst_destroy release the ort. Add some functions to operate the RTF_EXPIRES flag and expires(from) together. and change the code to use these new adding functions. Changes from v5: modify ip6_route_add and ndisc_router_discovery to use new adding functions. Only set dst.from when the ort has flag RTF_ADDRCONF and RTF_DEFAULT.then hold the ort. Signed-off-by: Gao feng --- include/net/dst.h | 6 +++- include/net/ip6_fib.h | 42 +++++++++++++++++++++++++++++ net/ipv6/addrconf.c | 9 ++---- net/ipv6/ip6_fib.c | 9 +++--- net/ipv6/ndisc.c | 3 +- net/ipv6/route.c | 71 ++++++++++++++++++++++++++++++------------------ 6 files changed, 99 insertions(+), 41 deletions(-) diff --git a/include/net/dst.h b/include/net/dst.h index 59c5d18..ff4da42 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -36,7 +36,11 @@ struct dst_entry { struct net_device *dev; struct dst_ops *ops; unsigned long _metrics; - unsigned long expires; + union { + unsigned long expires; + /* point to where the dst_entry copied from */ + struct dst_entry *from; + }; struct dst_entry *path; struct neighbour __rcu *_neighbour; #ifdef CONFIG_XFRM diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index b26bb81..c64778f 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -123,6 +123,48 @@ static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) return ((struct rt6_info *)dst)->rt6i_idev; } +static inline void rt6_clean_expires(struct rt6_info *rt) +{ + if (!(rt->rt6i_flags & RTF_EXPIRES) && rt->dst.from) + dst_release(rt->dst.from); + + rt->rt6i_flags &= ~RTF_EXPIRES; + rt->dst.expires = 0; +} + +static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires) +{ + if (!(rt->rt6i_flags & RTF_EXPIRES) && rt->dst.from) + dst_release(rt->dst.from); + + rt->rt6i_flags |= RTF_EXPIRES; + rt->dst.expires = expires; +} + +static inline void rt6_update_expires(struct rt6_info *rt, int timeout) +{ + if (!(rt->rt6i_flags & RTF_EXPIRES) && rt->dst.from) + dst_release(rt->dst.from); + + dst_set_expires(&rt->dst, timeout); + rt->rt6i_flags |= RTF_EXPIRES; +} + +static inline void rt6_set_from(struct rt6_info *rt, struct rt6_info *from) +{ + struct dst_entry *new = (struct dst_entry *) from; + + if (!(rt->rt6i_flags & RTF_EXPIRES) && rt->dst.from) { + if (new == rt->dst.from) + return; + dst_release(rt->dst.from); + } + + rt->rt6i_flags &= ~RTF_EXPIRES; + rt->dst.from = new; + dst_hold(new); +} + struct fib6_walker_t { struct list_head lh; struct fib6_node *root, *node; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 6a3bb60..7d5cb97 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -803,8 +803,7 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp) ip6_del_rt(rt); rt = NULL; } else if (!(rt->rt6i_flags & RTF_EXPIRES)) { - rt->dst.expires = expires; - rt->rt6i_flags |= RTF_EXPIRES; + rt6_set_expires(rt, expires); } } dst_release(&rt->dst); @@ -1887,11 +1886,9 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao) rt = NULL; } else if (addrconf_finite_timeout(rt_expires)) { /* not infinity */ - rt->dst.expires = jiffies + rt_expires; - rt->rt6i_flags |= RTF_EXPIRES; + rt6_set_expires(rt, jiffies + rt_expires); } else { - rt->rt6i_flags &= ~RTF_EXPIRES; - rt->dst.expires = 0; + rt6_clean_expires(rt); } } else if (valid_lft) { clock_t expires = 0; diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index 5b27fbc..dbf6c10 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -673,11 +673,10 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, &rt->rt6i_gateway)) { if (!(iter->rt6i_flags & RTF_EXPIRES)) return -EEXIST; - iter->dst.expires = rt->dst.expires; - if (!(rt->rt6i_flags & RTF_EXPIRES)) { - iter->rt6i_flags &= ~RTF_EXPIRES; - iter->dst.expires = 0; - } + if (!(rt->rt6i_flags & RTF_EXPIRES)) + rt6_clean_expires(iter); + else + rt6_set_expires(iter, rt->dst.expires); return -EEXIST; } } diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 3dcdb81..176b469 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -1264,8 +1264,7 @@ static void ndisc_router_discovery(struct sk_buff *skb) } if (rt) - rt->dst.expires = jiffies + (HZ * lifetime); - + rt6_set_expires(rt, jiffies + (HZ * lifetime)); if (ra_msg->icmph.icmp6_hop_limit) { in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; if (rt) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 3992e26..27068be 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -62,7 +62,7 @@ #include #endif -static struct rt6_info *ip6_rt_copy(const struct rt6_info *ort, +static struct rt6_info *ip6_rt_copy(struct rt6_info *ort, const struct in6_addr *dest); static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie); static unsigned int ip6_default_advmss(const struct dst_entry *dst); @@ -285,6 +285,10 @@ static void ip6_dst_destroy(struct dst_entry *dst) rt->rt6i_idev = NULL; in6_dev_put(idev); } + + if (!(rt->rt6i_flags & RTF_EXPIRES) && dst->from) + dst_release(dst->from); + if (peer) { rt->rt6i_peer = NULL; inet_putpeer(peer); @@ -329,8 +333,17 @@ static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, static __inline__ int rt6_check_expired(const struct rt6_info *rt) { - return (rt->rt6i_flags & RTF_EXPIRES) && - time_after(jiffies, rt->dst.expires); + struct rt6_info *ort = NULL; + + if (rt->rt6i_flags & RTF_EXPIRES) { + if (time_after(jiffies, rt->dst.expires)) + return 1; + } else if (rt->dst.from) { + ort = (struct rt6_info *) rt->dst.from; + return (ort->rt6i_flags & RTF_EXPIRES) && + time_after(jiffies, ort->dst.expires); + } + return 0; } static inline int rt6_need_strict(const struct in6_addr *daddr) @@ -620,12 +633,11 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); if (rt) { - if (!addrconf_finite_timeout(lifetime)) { - rt->rt6i_flags &= ~RTF_EXPIRES; - } else { - rt->dst.expires = jiffies + HZ * lifetime; - rt->rt6i_flags |= RTF_EXPIRES; - } + if (!addrconf_finite_timeout(lifetime)) + rt6_clean_expires(rt); + else + rt6_set_expires(rt, jiffies + HZ * lifetime); + dst_release(&rt->dst); } return 0; @@ -730,7 +742,7 @@ int ip6_ins_rt(struct rt6_info *rt) return __ip6_ins_rt(rt, &info); } -static struct rt6_info *rt6_alloc_cow(const struct rt6_info *ort, +static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, const struct in6_addr *daddr, const struct in6_addr *saddr) { @@ -954,10 +966,10 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori rt->rt6i_idev = ort->rt6i_idev; if (rt->rt6i_idev) in6_dev_hold(rt->rt6i_idev); - rt->dst.expires = 0; rt->rt6i_gateway = ort->rt6i_gateway; - rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES; + rt->rt6i_flags = ort->rt6i_flags; + rt6_clean_expires(rt); rt->rt6i_metric = 0; memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key)); @@ -1019,10 +1031,9 @@ static void ip6_link_failure(struct sk_buff *skb) rt = (struct rt6_info *) skb_dst(skb); if (rt) { - if (rt->rt6i_flags & RTF_CACHE) { - dst_set_expires(&rt->dst, 0); - rt->rt6i_flags |= RTF_EXPIRES; - } else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT)) + if (rt->rt6i_flags & RTF_CACHE) + rt6_update_expires(rt, 0); + else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT)) rt->rt6i_node->fn_sernum = -1; } } @@ -1289,9 +1300,12 @@ int ip6_route_add(struct fib6_config *cfg) } rt->dst.obsolete = -1; - rt->dst.expires = (cfg->fc_flags & RTF_EXPIRES) ? - jiffies + clock_t_to_jiffies(cfg->fc_expires) : - 0; + + if (cfg->fc_flags & RTF_EXPIRES) + rt6_set_expires(rt, jiffies + + clock_t_to_jiffies(cfg->fc_expires)); + else + rt6_clean_expires(rt); if (cfg->fc_protocol == RTPROT_UNSPEC) cfg->fc_protocol = RTPROT_BOOT; @@ -1736,8 +1750,8 @@ again: features |= RTAX_FEATURE_ALLFRAG; dst_metric_set(&rt->dst, RTAX_FEATURES, features); } - dst_set_expires(&rt->dst, net->ipv6.sysctl.ip6_rt_mtu_expires); - rt->rt6i_flags |= RTF_MODIFIED|RTF_EXPIRES; + rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires); + rt->rt6i_flags |= RTF_MODIFIED; goto out; } @@ -1765,9 +1779,8 @@ again: * which is 10 mins. After 10 mins the decreased pmtu is expired * and detecting PMTU increase will be automatically happened. */ - dst_set_expires(&nrt->dst, net->ipv6.sysctl.ip6_rt_mtu_expires); - nrt->rt6i_flags |= RTF_DYNAMIC|RTF_EXPIRES; - + rt6_update_expires(nrt, net->ipv6.sysctl.ip6_rt_mtu_expires); + nrt->rt6i_flags |= RTF_DYNAMIC; ip6_ins_rt(nrt); } out: @@ -1799,7 +1812,7 @@ void rt6_pmtu_discovery(const struct in6_addr *daddr, const struct in6_addr *sad * Misc support functions */ -static struct rt6_info *ip6_rt_copy(const struct rt6_info *ort, +static struct rt6_info *ip6_rt_copy(struct rt6_info *ort, const struct in6_addr *dest) { struct net *net = dev_net(ort->dst.dev); @@ -1819,10 +1832,14 @@ static struct rt6_info *ip6_rt_copy(const struct rt6_info *ort, if (rt->rt6i_idev) in6_dev_hold(rt->rt6i_idev); rt->dst.lastuse = jiffies; - rt->dst.expires = 0; rt->rt6i_gateway = ort->rt6i_gateway; - rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES; + rt->rt6i_flags = ort->rt6i_flags; + if ((ort->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) == + (RTF_DEFAULT | RTF_ADDRCONF)) + rt6_set_from(rt, ort); + else + rt6_clean_expires(rt); rt->rt6i_metric = 0; #ifdef CONFIG_IPV6_SUBTREES -- 1.7.7.6