| Message ID | 1475045878-30455-1-git-send-email-zenczykowski@gmail.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
Hello, On Wed, Sep 28, 2016, at 08:57, Maciej Żenczykowski wrote: > From: Maciej Żenczykowski <maze@google.com> > > This implements: > https://tools.ietf.org/html/rfc7559 > > Backoff is performed according to RFC3315 section 14: > https://tools.ietf.org/html/rfc3315#section-14 > > We allow setting /proc/sys/net/ipv6/conf/*/router_solicitations > to a negative value meaning an unlimited number of retransmits, > and we make this the new default (inline with the RFC). > > We also add a new setting: > /proc/sys/net/ipv6/conf/*/router_solicitation_max_interval > defaulting to 1 hour (per RFC recommendation). > > Signed-off-by: Maciej Żenczykowski <maze@google.com> > --- > include/linux/ipv6.h | 1 + > include/net/addrconf.h | 3 ++- > include/net/if_inet6.h | 1 + > include/uapi/linux/ipv6.h | 1 + > net/ipv6/addrconf.c | 51 > ++++++++++++++++++++++++++++++++++++++++------- > 5 files changed, 49 insertions(+), 8 deletions(-) > > diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h > index c6dbcd84a2c7..7e9a789be5e0 100644 > --- a/include/linux/ipv6.h > +++ b/include/linux/ipv6.h > @@ -18,6 +18,7 @@ struct ipv6_devconf { > __s32 dad_transmits; > __s32 rtr_solicits; > __s32 rtr_solicit_interval; > + __s32 rtr_solicit_max_interval; > __s32 rtr_solicit_delay; > __s32 force_mld_version; > __s32 mldv1_unsolicited_report_interval; > diff --git a/include/net/addrconf.h b/include/net/addrconf.h > index 9826d3a9464c..f2d072787947 100644 > --- a/include/net/addrconf.h > +++ b/include/net/addrconf.h > @@ -1,8 +1,9 @@ > #ifndef _ADDRCONF_H > #define _ADDRCONF_H > > -#define MAX_RTR_SOLICITATIONS 3 > +#define MAX_RTR_SOLICITATIONS -1 /* unlimited */ > #define RTR_SOLICITATION_INTERVAL (4*HZ) > +#define RTR_SOLICITATION_MAX_INTERVAL (3600*HZ) /* 1 hour */ > > #define MIN_VALID_LIFETIME (2*3600) /* 2 hours */ > > diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h > index 1c8b6820b694..515352c6280a 100644 > --- a/include/net/if_inet6.h > +++ b/include/net/if_inet6.h > @@ -201,6 +201,7 @@ struct inet6_dev { > struct ipv6_devstat stats; > > struct timer_list rs_timer; > + __s32 rs_interval; /* in jiffies */ > __u8 rs_probes; > > __u8 addr_gen_mode; > diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h > index 395876060f50..8c2772340c3f 100644 > --- a/include/uapi/linux/ipv6.h > +++ b/include/uapi/linux/ipv6.h > @@ -177,6 +177,7 @@ enum { > DEVCONF_DROP_UNICAST_IN_L2_MULTICAST, > DEVCONF_DROP_UNSOLICITED_NA, > DEVCONF_KEEP_ADDR_ON_DOWN, > + DEVCONF_RTR_SOLICIT_MAX_INTERVAL, > DEVCONF_MAX > }; > > diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c > index 2f1f5d439788..49bee9bc5ff3 100644 > --- 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); Could you use msecs_to_jiffies here to make the units more clear like I proposed in the last mail? Or is there a reason not to? Bye, Hannes
I'm not sure what line you're referring to. There are *no* outright jiffies or msecs in this patch, with the exception of the (3600*HZ) line which is already obvious enough. The 900000 200001 1900000 1000000 constants are not jiffies nor miliseconds, they're simply numbers, such that 900000/1000000 = 0.9 and 200001/1000000 =~ 0.2 (the +1 is to deal with 0) and 1900000/1000000 = 1.9
Passes my local unittest for this behaviour.
Acked-by: Erik Kline <ek@google.com>
From: Maciej Żenczykowski <zenczykowski@gmail.com> Date: Tue, 27 Sep 2016 23:57:58 -0700 > From: Maciej Żenczykowski <maze@google.com> > > This implements: > https://tools.ietf.org/html/rfc7559 > > Backoff is performed according to RFC3315 section 14: > https://tools.ietf.org/html/rfc3315#section-14 > > We allow setting /proc/sys/net/ipv6/conf/*/router_solicitations > to a negative value meaning an unlimited number of retransmits, > and we make this the new default (inline with the RFC). > > We also add a new setting: > /proc/sys/net/ipv6/conf/*/router_solicitation_max_interval > defaulting to 1 hour (per RFC recommendation). > > Signed-off-by: Maciej Żenczykowski <maze@google.com> Applied to net-next, thanks.
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index c6dbcd84a2c7..7e9a789be5e0 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -18,6 +18,7 @@ struct ipv6_devconf { __s32 dad_transmits; __s32 rtr_solicits; __s32 rtr_solicit_interval; + __s32 rtr_solicit_max_interval; __s32 rtr_solicit_delay; __s32 force_mld_version; __s32 mldv1_unsolicited_report_interval; diff --git a/include/net/addrconf.h b/include/net/addrconf.h index 9826d3a9464c..f2d072787947 100644 --- a/include/net/addrconf.h +++ b/include/net/addrconf.h @@ -1,8 +1,9 @@ #ifndef _ADDRCONF_H #define _ADDRCONF_H -#define MAX_RTR_SOLICITATIONS 3 +#define MAX_RTR_SOLICITATIONS -1 /* unlimited */ #define RTR_SOLICITATION_INTERVAL (4*HZ) +#define RTR_SOLICITATION_MAX_INTERVAL (3600*HZ) /* 1 hour */ #define MIN_VALID_LIFETIME (2*3600) /* 2 hours */ diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h index 1c8b6820b694..515352c6280a 100644 --- a/include/net/if_inet6.h +++ b/include/net/if_inet6.h @@ -201,6 +201,7 @@ struct inet6_dev { struct ipv6_devstat stats; struct timer_list rs_timer; + __s32 rs_interval; /* in jiffies */ __u8 rs_probes; __u8 addr_gen_mode; diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h index 395876060f50..8c2772340c3f 100644 --- a/include/uapi/linux/ipv6.h +++ b/include/uapi/linux/ipv6.h @@ -177,6 +177,7 @@ enum { DEVCONF_DROP_UNICAST_IN_L2_MULTICAST, DEVCONF_DROP_UNSOLICITED_NA, DEVCONF_KEEP_ADDR_ON_DOWN, + DEVCONF_RTR_SOLICIT_MAX_INTERVAL, DEVCONF_MAX }; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 2f1f5d439788..49bee9bc5ff3 100644 --- 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, @@ -3687,7 +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, @@ -3696,11 +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" @@ -3949,7 +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); @@ -3971,10 +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); } @@ -4891,6 +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; @@ -5099,7 +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); @@ -5128,8 +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 ... */ @@ -5778,6 +5808,13 @@ static const struct ctl_table addrconf_sysctl[] = { .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, .maxlen = sizeof(int),