From e953f89b8563efe0b92f70033d237874c43d4a3d Mon Sep 17 00:00:00 2001
From: Joel Scherpelz <jscherpelz@google.com>
Date: Wed, 22 Mar 2017 18:19:04 +0900
Subject: [PATCH] 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).
[backport of net-next bbea124bc99df968011e76eba105fe964a4eceab]
Bug: 33333670
Test: net_test passes
Signed-off-by: Joel Scherpelz <jscherpelz@google.com>
Acked-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
Documentation/networking/ip-sysctl.txt | 13 +++++++++++--
include/linux/ipv6.h | 1 +
include/uapi/linux/ipv6.h | 10 ++++++++++
include/uapi/linux/sysctl.h | 1 +
net/ipv6/addrconf.c | 10 ++++++++++
net/ipv6/ndisc.c | 2 ++
6 files changed, 35 insertions(+), 2 deletions(-)
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 2042261408b9..5f1ea84ed72b 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1413,11 +1413,20 @@ accept_ra_pinfo - BOOLEAN
Functional default: enabled if accept_ra is enabled.
disabled if accept_ra is disabled.
+accept_ra_rt_info_min_plen - INTEGER
+ Minimum prefix length of Route Information in RA.
+
+ Route Information w/ prefix smaller than this variable shall
+ be ignored.
+
+ Functional default: 0 if accept_ra_rtr_pref is enabled.
+ -1 if accept_ra_rtr_pref is disabled.
+
accept_ra_rt_info_max_plen - INTEGER
Maximum prefix length of Route Information in RA.
- Route Information w/ prefix larger than or equal to this
- variable shall be ignored.
+ Route Information w/ prefix larger than this variable shall
+ be ignored.
Functional default: 0 if accept_ra_rtr_pref is enabled.
-1 if accept_ra_rtr_pref is disabled.
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index ce777260e9ea..1182f0e21697 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -36,6 +36,7 @@ struct ipv6_devconf {
__s32 accept_ra_rtr_pref;
__s32 rtr_probe_interval;
#ifdef CONFIG_IPV6_ROUTE_INFO
+ __s32 accept_ra_rt_info_min_plen;
__s32 accept_ra_rt_info_max_plen;
#endif
#endif
diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h
index 2b1533859749..c462f1dc175e 100644
--- a/include/uapi/linux/ipv6.h
+++ b/include/uapi/linux/ipv6.h
@@ -175,6 +175,16 @@ enum {
DEVCONF_USE_OIF_ADDRS_ONLY,
DEVCONF_ACCEPT_RA_MIN_HOP_LIMIT,
DEVCONF_IGNORE_ROUTES_WITH_LINKDOWN,
+ DEVCONF_DROP_UNICAST_IN_L2_MULTICAST,
+ DEVCONF_DROP_UNSOLICITED_NA,
+ DEVCONF_KEEP_ADDR_ON_DOWN,
+ DEVCONF_RTR_SOLICIT_MAX_INTERVAL,
+ DEVCONF_SEG6_ENABLED,
+ DEVCONF_SEG6_REQUIRE_HMAC,
+ DEVCONF_ENHANCED_DAD,
+ DEVCONF_ADDR_GEN_MODE,
+ DEVCONF_DISABLE_POLICY,
+ DEVCONF_ACCEPT_RA_RT_INFO_MIN_PLEN,
DEVCONF_MAX
};
diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
index 0956373b56db..d18980e74534 100644
--- a/include/uapi/linux/sysctl.h
+++ b/include/uapi/linux/sysctl.h
@@ -570,6 +570,7 @@ enum {
NET_IPV6_PROXY_NDP=23,
NET_IPV6_ACCEPT_SOURCE_ROUTE=25,
NET_IPV6_ACCEPT_RA_FROM_LOCAL=26,
+ NET_IPV6_ACCEPT_RA_RT_INFO_MIN_PLEN=27,
__NET_IPV6_MAX
};
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 498a664b8dc9..860ffbe778cf 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -202,6 +202,7 @@ 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
@@ -247,6 +248,7 @@ 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
@@ -4689,6 +4691,7 @@ 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
@@ -5648,6 +5651,13 @@ static struct addrconf_sysctl_table
.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 84afb9a77278..3452f9037ad4 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1358,6 +1358,8 @@ 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,
--
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