From bbea124bc99df968011e76eba105fe964a4eceab Mon Sep 17 00:00:00 2001 From: Joel Scherpelz Date: Wed, 22 Mar 2017 18:19:04 +0900 Subject: net: ipv6: Add sysctl for minimum prefix len acceptable in RIOs. This commit adds a new sysctl accept_ra_rt_info_min_plen that defines the minimum acceptable prefix length of Route Information Options. The new sysctl is intended to be used together with accept_ra_rt_info_max_plen to configure a range of acceptable prefix lengths. It is useful to prevent misconfigurations from unintentionally blackholing too much of the IPv6 address space (e.g., home routers announcing RIOs for fc00::/7, which is incorrect). Signed-off-by: Joel Scherpelz Acked-by: Lorenzo Colitti Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 10 ++++++++++ net/ipv6/ndisc.c | 2 ++ 2 files changed, 12 insertions(+) (limited to 'net/ipv6') diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 8c69768a5c46..dff5beb26a01 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -224,6 +224,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = { .accept_ra_rtr_pref = 1, .rtr_probe_interval = 60 * HZ, #ifdef CONFIG_IPV6_ROUTE_INFO + .accept_ra_rt_info_min_plen = 0, .accept_ra_rt_info_max_plen = 0, #endif #endif @@ -277,6 +278,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = { .accept_ra_rtr_pref = 1, .rtr_probe_interval = 60 * HZ, #ifdef CONFIG_IPV6_ROUTE_INFO + .accept_ra_rt_info_min_plen = 0, .accept_ra_rt_info_max_plen = 0, #endif #endif @@ -4979,6 +4981,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf, array[DEVCONF_RTR_PROBE_INTERVAL] = jiffies_to_msecs(cnf->rtr_probe_interval); #ifdef CONFIG_IPV6_ROUTE_INFO + array[DEVCONF_ACCEPT_RA_RT_INFO_MIN_PLEN] = cnf->accept_ra_rt_info_min_plen; array[DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN] = cnf->accept_ra_rt_info_max_plen; #endif #endif @@ -6121,6 +6124,13 @@ static const struct ctl_table addrconf_sysctl[] = { .proc_handler = proc_dointvec_jiffies, }, #ifdef CONFIG_IPV6_ROUTE_INFO + { + .procname = "accept_ra_rt_info_min_plen", + .data = &ipv6_devconf.accept_ra_rt_info_min_plen, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, { .procname = "accept_ra_rt_info_max_plen", .data = &ipv6_devconf.accept_ra_rt_info_max_plen, diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 112ccbc0a8ac..b5812b3f7539 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -1418,6 +1418,8 @@ skip_linkparms: if (ri->prefix_len == 0 && !in6_dev->cnf.accept_ra_defrtr) continue; + if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen) + continue; if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) continue; rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3, -- cgit v1.2.2