Message ID | 1458642286-32021-1-git-send-email-luis.henriques@canonical.com |
---|---|
State | New |
Headers | show |
Hi, Luis Henriques wrote: > This is a note to let you know that I have just added a patch titled > > net/ipv6: add sysctl option accept_ra_min_hop_limit > > to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree > which can be found at: > > http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue > > This patch is scheduled to be released in version 3.16.7-ckt26. > > If you, or anyone else, feels it should not be added to this tree, please > reply to this email. > > For more information about the 3.16.y-ckt tree, see > https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable > > Thanks. > -Luis > > ---8<------------------------------------------------------------ > > From dafdd3bb2296d4b70703c0bdb725f3265064ba4a Mon Sep 17 00:00:00 2001 > From: Hangbin Liu <liuhangbin@gmail.com> > Date: Thu, 30 Jul 2015 14:28:42 +0800 > Subject: net/ipv6: add sysctl option accept_ra_min_hop_limit > > commit 8013d1d7eafb0589ca766db6b74026f76b7f5cb4 upstream. > > Commit 6fd99094de2b ("ipv6: Don't reduce hop limit for an interface") > disabled accept hop limit from RA if it is smaller than the current hop > limit for security stuff. But this behavior kind of break the RFC definition. > > RFC 4861, 6.3.4. Processing Received Router Advertisements > A Router Advertisement field (e.g., Cur Hop Limit, Reachable Time, > and Retrans Timer) may contain a value denoting that it is > unspecified. In such cases, the parameter should be ignored and the > host should continue using whatever value it is already using. > > If the received Cur Hop Limit value is non-zero, the host SHOULD set > its CurHopLimit variable to the received value. > > So add sysctl option accept_ra_min_hop_limit to let user choose the minimum > hop limit value they can accept from RA. And set default to 1 to meet RFC > standards. > > Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> > Acked-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com> > Signed-off-by: David S. Miller <davem@davemloft.net> > [ luis: backported to 3.16: adjusted context ] > Signed-off-by: Luis Henriques <luis.henriques@canonical.com> > --- > Documentation/networking/ip-sysctl.txt | 8 ++++++++ > include/linux/ipv6.h | 1 + > include/uapi/linux/ipv6.h | 1 + > net/ipv6/addrconf.c | 10 ++++++++++ > net/ipv6/ndisc.c | 16 +++++++--------- > 5 files changed, 27 insertions(+), 9 deletions(-) > > diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt > index ab42c95f9985..36aa39eee48f 100644 > --- a/Documentation/networking/ip-sysctl.txt > +++ b/Documentation/networking/ip-sysctl.txt > @@ -1210,6 +1210,14 @@ accept_ra_defrtr - BOOLEAN > Functional default: enabled if accept_ra is enabled. > disabled if accept_ra is disabled. > > +accept_ra_min_hop_limit - INTEGER > + Minimum hop limit Information in Router Advertisement. > + > + Hop limit Information in Router Advertisement less than this > + variable shall be ignored. > + > + Default: 1 > + > accept_ra_pinfo - BOOLEAN > Learn Prefix Information in Router Advertisement. > > diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h > index f3d5d11b8871..9cc2240d7e52 100644 > --- a/include/linux/ipv6.h > +++ b/include/linux/ipv6.h > @@ -29,6 +29,7 @@ struct ipv6_devconf { > __s32 max_desync_factor; > __s32 max_addresses; > __s32 accept_ra_defrtr; > + __s32 accept_ra_min_hop_limit; > __s32 accept_ra_pinfo; > #ifdef CONFIG_IPV6_ROUTER_PREF > __s32 accept_ra_rtr_pref; > diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h > index 593b0e32d956..f1d321427905 100644 > --- a/include/uapi/linux/ipv6.h > +++ b/include/uapi/linux/ipv6.h > @@ -163,6 +163,7 @@ enum { > DEVCONF_MLDV1_UNSOLICITED_REPORT_INTERVAL, > DEVCONF_MLDV2_UNSOLICITED_REPORT_INTERVAL, > DEVCONF_SUPPRESS_FRAG_NDISC, Please add followings: __DEVCONF_ACCEPT_RA_FROM_LOCAL, __DEVCONF_USE_OPTIMISTIC, __DEVCONF_ACCEPT_RA_MTU, __DEVCONF_STABLE_SECRET, __DEVCONF_USE_OIF_ADDRS_ONLY, Otherwise > + DEVCONF_ACCEPT_RA_MIN_HOP_LIMIT, has different value than the value we have in mainline. --yoshfuji > DEVCONF_MAX > }; > > diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c > index 75630e173adf..405575f9ae77 100644 > --- a/net/ipv6/addrconf.c > +++ b/net/ipv6/addrconf.c > @@ -186,6 +186,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = { > .max_desync_factor = MAX_DESYNC_FACTOR, > .max_addresses = IPV6_MAX_ADDRESSES, > .accept_ra_defrtr = 1, > + .accept_ra_min_hop_limit= 1, > .accept_ra_pinfo = 1, > #ifdef CONFIG_IPV6_ROUTER_PREF > .accept_ra_rtr_pref = 1, > @@ -222,6 +223,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = { > .max_desync_factor = MAX_DESYNC_FACTOR, > .max_addresses = IPV6_MAX_ADDRESSES, > .accept_ra_defrtr = 1, > + .accept_ra_min_hop_limit= 1, > .accept_ra_pinfo = 1, > #ifdef CONFIG_IPV6_ROUTER_PREF > .accept_ra_rtr_pref = 1, > @@ -4294,6 +4296,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, > array[DEVCONF_MAX_DESYNC_FACTOR] = cnf->max_desync_factor; > array[DEVCONF_MAX_ADDRESSES] = cnf->max_addresses; > array[DEVCONF_ACCEPT_RA_DEFRTR] = cnf->accept_ra_defrtr; > + array[DEVCONF_ACCEPT_RA_MIN_HOP_LIMIT] = cnf->accept_ra_min_hop_limit; > array[DEVCONF_ACCEPT_RA_PINFO] = cnf->accept_ra_pinfo; > #ifdef CONFIG_IPV6_ROUTER_PREF > array[DEVCONF_ACCEPT_RA_RTR_PREF] = cnf->accept_ra_rtr_pref; > @@ -5079,6 +5082,13 @@ static struct addrconf_sysctl_table > .proc_handler = proc_dointvec, > }, > { > + .procname = "accept_ra_min_hop_limit", > + .data = &ipv6_devconf.accept_ra_min_hop_limit, > + .maxlen = sizeof(int), > + .mode = 0644, > + .proc_handler = proc_dointvec, > + }, > + { > .procname = "accept_ra_pinfo", > .data = &ipv6_devconf.accept_ra_pinfo, > .maxlen = sizeof(int), > diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c > index e2eb53c719dc..577338204863 100644 > --- a/net/ipv6/ndisc.c > +++ b/net/ipv6/ndisc.c > @@ -1189,18 +1189,16 @@ static void ndisc_router_discovery(struct sk_buff *skb) > > if (rt) > rt6_set_expires(rt, jiffies + (HZ * lifetime)); > - if (ra_msg->icmph.icmp6_hop_limit) { > - /* Only set hop_limit on the interface if it is higher than > - * the current hop_limit. > - */ > - if (in6_dev->cnf.hop_limit < ra_msg->icmph.icmp6_hop_limit) { > + if (in6_dev->cnf.accept_ra_min_hop_limit < 256 && > + ra_msg->icmph.icmp6_hop_limit) { > + if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) { > in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; > + if (rt) > + dst_metric_set(&rt->dst, RTAX_HOPLIMIT, > + ra_msg->icmph.icmp6_hop_limit); > } else { > - ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than current\n"); > + ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n"); > } > - if (rt) > - dst_metric_set(&rt->dst, RTAX_HOPLIMIT, > - ra_msg->icmph.icmp6_hop_limit); > } > > skip_defrtr: >
On Tue, Mar 22, 2016 at 08:02:28PM +0900, YOSHIFUJI Hideaki/吉藤英明 wrote: > > diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h > > index 593b0e32d956..f1d321427905 100644 > > --- a/include/uapi/linux/ipv6.h > > +++ b/include/uapi/linux/ipv6.h > > @@ -163,6 +163,7 @@ enum { > > DEVCONF_MLDV1_UNSOLICITED_REPORT_INTERVAL, > > DEVCONF_MLDV2_UNSOLICITED_REPORT_INTERVAL, > > DEVCONF_SUPPRESS_FRAG_NDISC, > > Please add followings: > __DEVCONF_ACCEPT_RA_FROM_LOCAL, > __DEVCONF_USE_OPTIMISTIC, > __DEVCONF_ACCEPT_RA_MTU, > __DEVCONF_STABLE_SECRET, > __DEVCONF_USE_OIF_ADDRS_ONLY, > > Otherwise > > > + DEVCONF_ACCEPT_RA_MIN_HOP_LIMIT, > > has different value than the value we have in mainline. Thank you for your review, Yoshifuji. I guess that makes sense, as this is an uapi include file. I'll modify this patch to include these additional definitions in the enum. Cheers, -- Luís
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index ab42c95f9985..36aa39eee48f 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -1210,6 +1210,14 @@ accept_ra_defrtr - BOOLEAN Functional default: enabled if accept_ra is enabled. disabled if accept_ra is disabled. +accept_ra_min_hop_limit - INTEGER + Minimum hop limit Information in Router Advertisement. + + Hop limit Information in Router Advertisement less than this + variable shall be ignored. + + Default: 1 + accept_ra_pinfo - BOOLEAN Learn Prefix Information in Router Advertisement. diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index f3d5d11b8871..9cc2240d7e52 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -29,6 +29,7 @@ struct ipv6_devconf { __s32 max_desync_factor; __s32 max_addresses; __s32 accept_ra_defrtr; + __s32 accept_ra_min_hop_limit; __s32 accept_ra_pinfo; #ifdef CONFIG_IPV6_ROUTER_PREF __s32 accept_ra_rtr_pref; diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h index 593b0e32d956..f1d321427905 100644 --- a/include/uapi/linux/ipv6.h +++ b/include/uapi/linux/ipv6.h @@ -163,6 +163,7 @@ enum { DEVCONF_MLDV1_UNSOLICITED_REPORT_INTERVAL, DEVCONF_MLDV2_UNSOLICITED_REPORT_INTERVAL, DEVCONF_SUPPRESS_FRAG_NDISC, + DEVCONF_ACCEPT_RA_MIN_HOP_LIMIT, DEVCONF_MAX }; diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 75630e173adf..405575f9ae77 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -186,6 +186,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = { .max_desync_factor = MAX_DESYNC_FACTOR, .max_addresses = IPV6_MAX_ADDRESSES, .accept_ra_defrtr = 1, + .accept_ra_min_hop_limit= 1, .accept_ra_pinfo = 1, #ifdef CONFIG_IPV6_ROUTER_PREF .accept_ra_rtr_pref = 1, @@ -222,6 +223,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = { .max_desync_factor = MAX_DESYNC_FACTOR, .max_addresses = IPV6_MAX_ADDRESSES, .accept_ra_defrtr = 1, + .accept_ra_min_hop_limit= 1, .accept_ra_pinfo = 1, #ifdef CONFIG_IPV6_ROUTER_PREF .accept_ra_rtr_pref = 1, @@ -4294,6 +4296,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, array[DEVCONF_MAX_DESYNC_FACTOR] = cnf->max_desync_factor; array[DEVCONF_MAX_ADDRESSES] = cnf->max_addresses; array[DEVCONF_ACCEPT_RA_DEFRTR] = cnf->accept_ra_defrtr; + array[DEVCONF_ACCEPT_RA_MIN_HOP_LIMIT] = cnf->accept_ra_min_hop_limit; array[DEVCONF_ACCEPT_RA_PINFO] = cnf->accept_ra_pinfo; #ifdef CONFIG_IPV6_ROUTER_PREF array[DEVCONF_ACCEPT_RA_RTR_PREF] = cnf->accept_ra_rtr_pref; @@ -5079,6 +5082,13 @@ static struct addrconf_sysctl_table .proc_handler = proc_dointvec, }, { + .procname = "accept_ra_min_hop_limit", + .data = &ipv6_devconf.accept_ra_min_hop_limit, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { .procname = "accept_ra_pinfo", .data = &ipv6_devconf.accept_ra_pinfo, .maxlen = sizeof(int), diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index e2eb53c719dc..577338204863 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -1189,18 +1189,16 @@ static void ndisc_router_discovery(struct sk_buff *skb) if (rt) rt6_set_expires(rt, jiffies + (HZ * lifetime)); - if (ra_msg->icmph.icmp6_hop_limit) { - /* Only set hop_limit on the interface if it is higher than - * the current hop_limit. - */ - if (in6_dev->cnf.hop_limit < ra_msg->icmph.icmp6_hop_limit) { + if (in6_dev->cnf.accept_ra_min_hop_limit < 256 && + ra_msg->icmph.icmp6_hop_limit) { + if (in6_dev->cnf.accept_ra_min_hop_limit <= ra_msg->icmph.icmp6_hop_limit) { in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; + if (rt) + dst_metric_set(&rt->dst, RTAX_HOPLIMIT, + ra_msg->icmph.icmp6_hop_limit); } else { - ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than current\n"); + ND_PRINTK(2, warn, "RA: Got route advertisement with lower hop_limit than minimum\n"); } - if (rt) - dst_metric_set(&rt->dst, RTAX_HOPLIMIT, - ra_msg->icmph.icmp6_hop_limit); } skip_defrtr: