ipv6 addrconf: implement RFC7559 router solicitation backoff

[cascardo/linux.git] / net / ipv6 / addrconf.c

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f418d2e..8718398 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -112,6 +112,27 @@ static inline u32 cstamp_delta(unsigned long cstamp)
        return (cstamp - INITIAL_JIFFIES) * 100UL / HZ;
 }
 
+static inline s32 rfc3315_s14_backoff_init(s32 irt)
+{
+       /* multiply 'initial retransmission time' by 0.9 .. 1.1 */
+       u64 tmp = (900000 + prandom_u32() % 200001) * (u64)irt;
+       do_div(tmp, 1000000);
+       return (s32)tmp;
+}
+
+static inline s32 rfc3315_s14_backoff_update(s32 rt, s32 mrt)
+{
+       /* multiply 'retransmission timeout' by 1.9 .. 2.1 */
+       u64 tmp = (1900000 + prandom_u32() % 200001) * (u64)rt;
+       do_div(tmp, 1000000);
+       if ((s32)tmp > mrt) {
+               /* multiply 'maximum retransmission time' by 0.9 .. 1.1 */
+               tmp = (900000 + prandom_u32() % 200001) * (u64)mrt;
+               do_div(tmp, 1000000);
+       }
+       return (s32)tmp;
+}
+
 #ifdef CONFIG_SYSCTL
 static int addrconf_sysctl_register(struct inet6_dev *idev);
 static void addrconf_sysctl_unregister(struct inet6_dev *idev);
@@ -187,6 +208,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
        .dad_transmits          = 1,
        .rtr_solicits           = MAX_RTR_SOLICITATIONS,
        .rtr_solicit_interval   = RTR_SOLICITATION_INTERVAL,
+       .rtr_solicit_max_interval = RTR_SOLICITATION_MAX_INTERVAL,
        .rtr_solicit_delay      = MAX_RTR_SOLICITATION_DELAY,
        .use_tempaddr           = 0,
        .temp_valid_lft         = TEMP_VALID_LIFETIME,
@@ -232,6 +254,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
        .dad_transmits          = 1,
        .rtr_solicits           = MAX_RTR_SOLICITATIONS,
        .rtr_solicit_interval   = RTR_SOLICITATION_INTERVAL,
+       .rtr_solicit_max_interval = RTR_SOLICITATION_MAX_INTERVAL,
        .rtr_solicit_delay      = MAX_RTR_SOLICITATION_DELAY,
        .use_tempaddr           = 0,
        .temp_valid_lft         = TEMP_VALID_LIFETIME,
@@ -778,7 +801,14 @@ static int addrconf_fixup_forwarding(struct ctl_table *table, int *p, int newf)
        }
 
        if (p == &net->ipv6.devconf_all->forwarding) {
+               int old_dflt = net->ipv6.devconf_dflt->forwarding;
+
                net->ipv6.devconf_dflt->forwarding = newf;
+               if ((!newf) ^ (!old_dflt))
+                       inet6_netconf_notify_devconf(net, NETCONFA_FORWARDING,
+                                                    NETCONFA_IFINDEX_DEFAULT,
+                                                    net->ipv6.devconf_dflt);
+
                addrconf_forward_change(net, newf);
                if ((!newf) ^ (!old))
                        inet6_netconf_notify_devconf(net, NETCONFA_FORWARDING,
@@ -1941,6 +1971,7 @@ errdad:
        spin_unlock_bh(&ifp->lock);
 
        addrconf_mod_dad_work(ifp, 0);
+       in6_ifa_put(ifp);
 }
 
 /* Join to solicited addr multicast group.
@@ -3679,7 +3710,7 @@ static void addrconf_rs_timer(unsigned long data)
        if (idev->if_flags & IF_RA_RCVD)
                goto out;
 
-       if (idev->rs_probes++ < idev->cnf.rtr_solicits) {
+       if (idev->rs_probes++ < idev->cnf.rtr_solicits || idev->cnf.rtr_solicits < 0) {
                write_unlock(&idev->lock);
                if (!ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE))
                        ndisc_send_rs(dev, &lladdr,
@@ -3688,11 +3719,13 @@ static void addrconf_rs_timer(unsigned long data)
                        goto put;
 
                write_lock(&idev->lock);
+               idev->rs_interval = rfc3315_s14_backoff_update(
+                       idev->rs_interval, idev->cnf.rtr_solicit_max_interval);
                /* 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);
+                                     idev->rs_interval);
        } else {
                /*
                 * Note: we do not support deprecated "all on-link"
@@ -3850,6 +3883,7 @@ static void addrconf_dad_work(struct work_struct *w)
                addrconf_dad_begin(ifp);
                goto out;
        } else if (action == DAD_ABORT) {
+               in6_ifa_hold(ifp);
                addrconf_dad_stop(ifp, 1);
                if (disable_ipv6)
                        addrconf_ifdown(idev->dev, 0);
@@ -3940,7 +3974,7 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp)
        send_mld = ifp->scope == IFA_LINK && ipv6_lonely_lladdr(ifp);
        send_rs = send_mld &&
                  ipv6_accept_ra(ifp->idev) &&
-                 ifp->idev->cnf.rtr_solicits > 0 &&
+                 ifp->idev->cnf.rtr_solicits != 0 &&
                  (dev->flags&IFF_LOOPBACK) == 0;
        read_unlock_bh(&ifp->idev->lock);
 
@@ -3962,10 +3996,11 @@ static void addrconf_dad_completed(struct inet6_ifaddr *ifp)
 
                write_lock_bh(&ifp->idev->lock);
                spin_lock(&ifp->lock);
+               ifp->idev->rs_interval = rfc3315_s14_backoff_init(
+                       ifp->idev->cnf.rtr_solicit_interval);
                ifp->idev->rs_probes = 1;
                ifp->idev->if_flags |= IF_RS_SENT;
-               addrconf_mod_rs_timer(ifp->idev,
-                                     ifp->idev->cnf.rtr_solicit_interval);
+               addrconf_mod_rs_timer(ifp->idev, ifp->idev->rs_interval);
                spin_unlock(&ifp->lock);
                write_unlock_bh(&ifp->idev->lock);
        }
@@ -4882,6 +4917,8 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
        array[DEVCONF_RTR_SOLICITS] = cnf->rtr_solicits;
        array[DEVCONF_RTR_SOLICIT_INTERVAL] =
                jiffies_to_msecs(cnf->rtr_solicit_interval);
+       array[DEVCONF_RTR_SOLICIT_MAX_INTERVAL] =
+               jiffies_to_msecs(cnf->rtr_solicit_max_interval);
        array[DEVCONF_RTR_SOLICIT_DELAY] =
                jiffies_to_msecs(cnf->rtr_solicit_delay);
        array[DEVCONF_FORCE_MLD_VERSION] = cnf->force_mld_version;
@@ -4952,18 +4989,18 @@ static inline size_t inet6_if_nlmsg_size(void)
 }
 
 static inline void __snmp6_fill_statsdev(u64 *stats, atomic_long_t *mib,
-                                     int items, int bytes)
+                                       int bytes)
 {
        int i;
-       int pad = bytes - sizeof(u64) * items;
+       int pad = bytes - sizeof(u64) * ICMP6_MIB_MAX;
        BUG_ON(pad < 0);
 
        /* Use put_unaligned() because stats may not be aligned for u64. */
-       put_unaligned(items, &stats[0]);
-       for (i = 1; i < items; i++)
+       put_unaligned(ICMP6_MIB_MAX, &stats[0]);
+       for (i = 1; i < ICMP6_MIB_MAX; i++)
                put_unaligned(atomic_long_read(&mib[i]), &stats[i]);
 
-       memset(&stats[items], 0, pad);
+       memset(&stats[ICMP6_MIB_MAX], 0, pad);
 }
 
 static inline void __snmp6_fill_stats64(u64 *stats, void __percpu *mib,
@@ -4996,7 +5033,7 @@ static void snmp6_fill_stats(u64 *stats, struct inet6_dev *idev, int attrtype,
                                     offsetof(struct ipstats_mib, syncp));
                break;
        case IFLA_INET6_ICMP6STATS:
-               __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs, ICMP6_MIB_MAX, bytes);
+               __snmp6_fill_statsdev(stats, idev->stats.icmpv6dev->mibs, bytes);
                break;
        }
 }
@@ -5090,7 +5127,7 @@ static int inet6_set_iftoken(struct inet6_dev *idev, struct in6_addr *token)
                return -EINVAL;
        if (!ipv6_accept_ra(idev))
                return -EINVAL;
-       if (idev->cnf.rtr_solicits <= 0)
+       if (idev->cnf.rtr_solicits == 0)
                return -EINVAL;
 
        write_lock_bh(&idev->lock);
@@ -5119,8 +5156,10 @@ update_lft:
 
        if (update_rs) {
                idev->if_flags |= IF_RS_SENT;
+               idev->rs_interval = rfc3315_s14_backoff_init(
+                       idev->cnf.rtr_solicit_interval);
                idev->rs_probes = 1;
-               addrconf_mod_rs_timer(idev, idev->cnf.rtr_solicit_interval);
+               addrconf_mod_rs_timer(idev, idev->rs_interval);
        }
 
        /* Well, that's kinda nasty ... */
@@ -5768,6 +5807,13 @@ static const struct ctl_table addrconf_sysctl[] = {
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
+       {
+               .procname       = "router_solicitation_max_interval",
+               .data           = &ipv6_devconf.rtr_solicit_max_interval,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec_jiffies,
+       },
        {
                .procname       = "router_solicitation_delay",
                .data           = &ipv6_devconf.rtr_solicit_delay,
@@ -6025,7 +6071,7 @@ static const struct ctl_table addrconf_sysctl[] = {
 static int __addrconf_sysctl_register(struct net *net, char *dev_name,
                struct inet6_dev *idev, struct ipv6_devconf *p)
 {
-       int i;
+       int i, ifindex;
        struct ctl_table *table;
        char path[sizeof("net/ipv6/conf/") + IFNAMSIZ];
 
@@ -6045,6 +6091,13 @@ static int __addrconf_sysctl_register(struct net *net, char *dev_name,
        if (!p->sysctl_header)
                goto free;
 
+       if (!strcmp(dev_name, "all"))
+               ifindex = NETCONFA_IFINDEX_ALL;
+       else if (!strcmp(dev_name, "default"))
+               ifindex = NETCONFA_IFINDEX_DEFAULT;
+       else
+               ifindex = idev->dev->ifindex;
+       inet6_netconf_notify_devconf(net, NETCONFA_ALL, ifindex, p);
        return 0;
 
 free: