From b7b1bfce0bb68bd8f6e62a28295922785cc63781 Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Sun, 23 Jun 2013 18:39:01 +0200 Subject: [PATCH] ipv6: split duplicate address detection and router solicitation timer This patch splits the timers for duplicate address detection and router solicitations apart. The router solicitations timer goes into inet6_dev and the dad timer stays in inet6_ifaddr. The reason behind this patch is to reduce the number of unneeded router solicitations send out by the host if additional link-local addresses are created. Currently we send out RS for every link-local address on an interface. If the RS timer fires we pick a source address with ipv6_get_lladdr. This change could hurt people adding additional link-local addresses and specifying these addresses in the radvd clients section because we no longer guarantee that we use every ll address as source address in router solicitations. Cc: Flavio Leitner Cc: Hideaki YOSHIFUJI Cc: David Stevens Signed-off-by: Hannes Frederic Sowa Reviewed-by: Flavio Leitner Signed-off-by: David S. Miller --- include/net/if_inet6.h | 8 +- net/ipv6/addrconf.c | 166 +++++++++++++++++++++++------------------ 2 files changed, 98 insertions(+), 76 deletions(-) diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h index e07feb456d19..e4c5a2d2ba34 100644 --- a/include/net/if_inet6.h +++ b/include/net/if_inet6.h @@ -50,7 +50,7 @@ struct inet6_ifaddr { int state; - __u8 probes; + __u8 dad_probes; __u8 flags; __u16 scope; @@ -58,7 +58,7 @@ struct inet6_ifaddr { unsigned long cstamp; /* created timestamp */ unsigned long tstamp; /* updated timestamp */ - struct timer_list timer; + struct timer_list dad_timer; struct inet6_dev *idev; struct rt6_info *rt; @@ -195,6 +195,10 @@ struct inet6_dev { struct neigh_parms *nd_parms; struct ipv6_devconf cnf; struct ipv6_devstat stats; + + struct timer_list rs_timer; + __u8 rs_probes; + unsigned long tstamp; /* ipv6InterfaceTable update timestamp */ struct rcu_head rcu; }; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 90788a1c6bbc..c06bc76280b2 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -253,37 +253,32 @@ static inline bool addrconf_qdisc_ok(const struct net_device *dev) return !qdisc_tx_is_noop(dev); } -static void addrconf_del_timer(struct inet6_ifaddr *ifp) +static void addrconf_del_rs_timer(struct inet6_dev *idev) { - if (del_timer(&ifp->timer)) + if (del_timer(&idev->rs_timer)) + __in6_dev_put(idev); +} + +static void addrconf_del_dad_timer(struct inet6_ifaddr *ifp) +{ + if (del_timer(&ifp->dad_timer)) __in6_ifa_put(ifp); } -enum addrconf_timer_t { - AC_NONE, - AC_DAD, - AC_RS, -}; - -static void addrconf_mod_timer(struct inet6_ifaddr *ifp, - enum addrconf_timer_t what, - unsigned long when) +static void addrconf_mod_rs_timer(struct inet6_dev *idev, + unsigned long when) { - if (!del_timer(&ifp->timer)) - in6_ifa_hold(ifp); + if (!timer_pending(&idev->rs_timer)) + in6_dev_hold(idev); + mod_timer(&idev->rs_timer, jiffies + when); +} - switch (what) { - case AC_DAD: - ifp->timer.function = addrconf_dad_timer; - break; - case AC_RS: - ifp->timer.function = addrconf_rs_timer; - break; - default: - break; - } - ifp->timer.expires = jiffies + when; - add_timer(&ifp->timer); +static void addrconf_mod_dad_timer(struct inet6_ifaddr *ifp, + unsigned long when) +{ + if (!timer_pending(&ifp->dad_timer)) + in6_ifa_hold(ifp); + mod_timer(&ifp->dad_timer, jiffies + when); } static int snmp6_alloc_dev(struct inet6_dev *idev) @@ -326,6 +321,7 @@ void in6_dev_finish_destroy(struct inet6_dev *idev) WARN_ON(!list_empty(&idev->addr_list)); WARN_ON(idev->mc_list != NULL); + WARN_ON(timer_pending(&idev->rs_timer)); #ifdef NET_REFCNT_DEBUG pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL"); @@ -357,7 +353,8 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev) rwlock_init(&ndev->lock); ndev->dev = dev; INIT_LIST_HEAD(&ndev->addr_list); - + setup_timer(&ndev->rs_timer, addrconf_rs_timer, + (unsigned long)ndev); memcpy(&ndev->cnf, dev_net(dev)->ipv6.devconf_dflt, sizeof(ndev->cnf)); ndev->cnf.mtu6 = dev->mtu; ndev->cnf.sysctl = NULL; @@ -776,7 +773,7 @@ void inet6_ifa_finish_destroy(struct inet6_ifaddr *ifp) in6_dev_put(ifp->idev); - if (del_timer(&ifp->timer)) + if (del_timer(&ifp->dad_timer)) pr_notice("Timer is still running, when freeing ifa=%p\n", ifp); if (ifp->state != INET6_IFADDR_STATE_DEAD) { @@ -869,9 +866,9 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen, spin_lock_init(&ifa->lock); spin_lock_init(&ifa->state_lock); - init_timer(&ifa->timer); + setup_timer(&ifa->dad_timer, addrconf_dad_timer, + (unsigned long)ifa); INIT_HLIST_NODE(&ifa->addr_lst); - ifa->timer.data = (unsigned long) ifa; ifa->scope = scope; ifa->prefix_len = pfxlen; ifa->flags = flags | IFA_F_TENTATIVE; @@ -994,7 +991,7 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp) } write_unlock_bh(&idev->lock); - addrconf_del_timer(ifp); + addrconf_del_dad_timer(ifp); ipv6_ifa_notify(RTM_DELADDR, ifp); @@ -1447,6 +1444,23 @@ try_nextdev: } EXPORT_SYMBOL(ipv6_dev_get_saddr); +static int __ipv6_get_lladdr(struct inet6_dev *idev, struct in6_addr *addr, + unsigned char banned_flags) +{ + struct inet6_ifaddr *ifp; + int err = -EADDRNOTAVAIL; + + list_for_each_entry(ifp, &idev->addr_list, if_list) { + if (ifp->scope == IFA_LINK && + !(ifp->flags & banned_flags)) { + *addr = ifp->addr; + err = 0; + break; + } + } + return err; +} + int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr, unsigned char banned_flags) { @@ -1456,17 +1470,8 @@ int ipv6_get_lladdr(struct net_device *dev, struct in6_addr *addr, rcu_read_lock(); idev = __in6_dev_get(dev); if (idev) { - struct inet6_ifaddr *ifp; - read_lock_bh(&idev->lock); - list_for_each_entry(ifp, &idev->addr_list, if_list) { - if (ifp->scope == IFA_LINK && - !(ifp->flags & banned_flags)) { - *addr = ifp->addr; - err = 0; - break; - } - } + err = __ipv6_get_lladdr(idev, addr, banned_flags); read_unlock_bh(&idev->lock); } rcu_read_unlock(); @@ -1580,7 +1585,7 @@ static void addrconf_dad_stop(struct inet6_ifaddr *ifp, int dad_failed) { if (ifp->flags&IFA_F_PERMANENT) { spin_lock_bh(&ifp->lock); - addrconf_del_timer(ifp); + addrconf_del_dad_timer(ifp); ifp->flags |= IFA_F_TENTATIVE; if (dad_failed) ifp->flags |= IFA_F_DADFAILED; @@ -3036,7 +3041,7 @@ static int addrconf_ifdown(struct net_device *dev, int how) hlist_for_each_entry_rcu(ifa, h, addr_lst) { if (ifa->idev == idev) { hlist_del_init_rcu(&ifa->addr_lst); - addrconf_del_timer(ifa); + addrconf_del_dad_timer(ifa); goto restart; } } @@ -3045,6 +3050,8 @@ static int addrconf_ifdown(struct net_device *dev, int how) write_lock_bh(&idev->lock); + addrconf_del_rs_timer(idev); + /* Step 2: clear flags for stateless addrconf */ if (!how) idev->if_flags &= ~(IF_RS_SENT|IF_RA_RCVD|IF_READY); @@ -3074,7 +3081,7 @@ static int addrconf_ifdown(struct net_device *dev, int how) while (!list_empty(&idev->addr_list)) { ifa = list_first_entry(&idev->addr_list, struct inet6_ifaddr, if_list); - addrconf_del_timer(ifa); + addrconf_del_dad_timer(ifa); list_del(&ifa->if_list); @@ -3116,10 +3123,10 @@ static int addrconf_ifdown(struct net_device *dev, int how) static void addrconf_rs_timer(unsigned long data) { - struct inet6_ifaddr *ifp = (struct inet6_ifaddr *) data; - struct inet6_dev *idev = ifp->idev; + struct inet6_dev *idev = (struct inet6_dev *)data; + struct in6_addr lladdr; - read_lock(&idev->lock); + write_lock(&idev->lock); if (idev->dead || !(idev->if_flags & IF_READY)) goto out; @@ -3130,18 +3137,19 @@ static void addrconf_rs_timer(unsigned long data) if (idev->if_flags & IF_RA_RCVD) goto out; - spin_lock(&ifp->lock); - if (ifp->probes++ < idev->cnf.rtr_solicits) { - /* The wait after the last probe can be shorter */ - addrconf_mod_timer(ifp, AC_RS, - (ifp->probes == idev->cnf.rtr_solicits) ? - idev->cnf.rtr_solicit_delay : - idev->cnf.rtr_solicit_interval); - spin_unlock(&ifp->lock); + if (idev->rs_probes++ < idev->cnf.rtr_solicits) { + if (!__ipv6_get_lladdr(idev, &lladdr, IFA_F_TENTATIVE)) + ndisc_send_rs(idev->dev, &lladdr, + &in6addr_linklocal_allrouters); + else + goto out; - ndisc_send_rs(idev->dev, &ifp->addr, &in6addr_linklocal_allrouters); + /* The wait after the last probe can be shorter */ + addrconf_mod_rs_timer(idev, (idev->rs_probes == + idev->cnf.rtr_solicits) ? + idev->cnf.rtr_solicit_delay : + idev->cnf.rtr_solicit_interval); } else { - spin_unlock(&ifp->lock); /* * Note: we do not support deprecated "all on-link" * assumption any longer. @@ -3150,8 +3158,8 @@ static void addrconf_rs_timer(unsigned long data) } out: - read_unlock(&idev->lock); - in6_ifa_put(ifp); + write_unlock(&idev->lock); + in6_dev_put(idev); } /* @@ -3167,8 +3175,8 @@ static void addrconf_dad_kick(struct inet6_ifaddr *ifp) else rand_num = net_random() % (idev->cnf.rtr_solicit_delay ? : 1); - ifp->probes = idev->cnf.dad_transmits; - addrconf_mod_timer(ifp, AC_DAD, rand_num); + ifp->dad_probes = idev->cnf.dad_transmits; + addrconf_mod_dad_timer(ifp, rand_num); } static void addrconf_dad_start(struct inet6_ifaddr *ifp) @@ -3229,40 +3237,40 @@ static void addrconf_dad_timer(unsigned long data) struct inet6_dev *idev = ifp->idev; struct in6_addr mcaddr; - if (!ifp->probes && addrconf_dad_end(ifp)) + if (!ifp->dad_probes && addrconf_dad_end(ifp)) goto out; - read_lock(&idev->lock); + write_lock(&idev->lock); if (idev->dead || !(idev->if_flags & IF_READY)) { - read_unlock(&idev->lock); + write_unlock(&idev->lock); goto out; } spin_lock(&ifp->lock); if (ifp->state == INET6_IFADDR_STATE_DEAD) { spin_unlock(&ifp->lock); - read_unlock(&idev->lock); + write_unlock(&idev->lock); goto out; } - if (ifp->probes == 0) { + if (ifp->dad_probes == 0) { /* * DAD was successful */ ifp->flags &= ~(IFA_F_TENTATIVE|IFA_F_OPTIMISTIC|IFA_F_DADFAILED); spin_unlock(&ifp->lock); - read_unlock(&idev->lock); + write_unlock(&idev->lock); addrconf_dad_completed(ifp); goto out; } - ifp->probes--; - addrconf_mod_timer(ifp, AC_DAD, ifp->idev->nd_parms->retrans_time); + ifp->dad_probes--; + addrconf_mod_dad_timer(ifp, ifp->idev->nd_parms->retrans_time); spin_unlock(&ifp->lock); - read_unlock(&idev->lock); + write_unlock(&idev->lock); /* send a neighbour solicitation for our addr */ addrconf_addr_solict_mult(&ifp->addr, &mcaddr); @@ -3274,6 +3282,9 @@ out: static void addrconf_dad_completed(struct inet6_ifaddr *ifp) { struct net_device *dev = ifp->idev->dev; + struct in6_addr lladdr; + + addrconf_del_dad_timer(ifp); /* * Configure the address for reception. Now it is valid. @@ -3294,13 +3305,20 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp) * [...] as part of DAD [...] there is no need * to delay again before sending the first RS */ - ndisc_send_rs(ifp->idev->dev, &ifp->addr, &in6addr_linklocal_allrouters); + if (!ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE)) + ndisc_send_rs(dev, &lladdr, + &in6addr_linklocal_allrouters); + else + return; - spin_lock_bh(&ifp->lock); - ifp->probes = 1; + write_lock_bh(&ifp->idev->lock); + spin_lock(&ifp->lock); + ifp->idev->rs_probes = 1; ifp->idev->if_flags |= IF_RS_SENT; - addrconf_mod_timer(ifp, AC_RS, ifp->idev->cnf.rtr_solicit_interval); - spin_unlock_bh(&ifp->lock); + addrconf_mod_rs_timer(ifp->idev, + ifp->idev->cnf.rtr_solicit_interval); + spin_unlock(&ifp->lock); + write_unlock_bh(&ifp->idev->lock); } }