summaryrefslogtreecommitdiff
path: root/net/ipv6
diff options
context:
space:
mode:
authorPatrick Rohr <prohr@google.com>2023-07-19 07:52:13 -0700
committerDavid S. Miller <davem@davemloft.net>2023-07-23 11:51:24 +0100
commit1671bcfd76fdc0b9e65153cf759153083755fe4c (patch)
tree2cdf85b02de36c2fe6ad26db0cf77c6a6a47717f /net/ipv6
parent5c9f7b04aadf79f783542d096dfbb8184e7c91f5 (diff)
net: add sysctl accept_ra_min_rtr_lft
This change adds a new sysctl accept_ra_min_rtr_lft to specify the minimum acceptable router lifetime in an RA. If the received RA router lifetime is less than the configured value (and not 0), the RA is ignored. This is useful for mobile devices, whose battery life can be impacted by networks that configure RAs with a short lifetime. On such networks, the device should never gain IPv6 provisioning and should attempt to drop RAs via hardware offload, if available. Signed-off-by: Patrick Rohr <prohr@google.com> Cc: Maciej Żenczykowski <maze@google.com> Cc: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/addrconf.c10
-rw-r--r--net/ipv6/ndisc.c18
2 files changed, 26 insertions, 2 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index e5213e598a04..19eb4b3d26ea 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -202,6 +202,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
.ra_defrtr_metric = IP6_RT_PRIO_USER,
.accept_ra_from_local = 0,
.accept_ra_min_hop_limit= 1,
+ .accept_ra_min_rtr_lft = 0,
.accept_ra_pinfo = 1,
#ifdef CONFIG_IPV6_ROUTER_PREF
.accept_ra_rtr_pref = 1,
@@ -262,6 +263,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
.ra_defrtr_metric = IP6_RT_PRIO_USER,
.accept_ra_from_local = 0,
.accept_ra_min_hop_limit= 1,
+ .accept_ra_min_rtr_lft = 0,
.accept_ra_pinfo = 1,
#ifdef CONFIG_IPV6_ROUTER_PREF
.accept_ra_rtr_pref = 1,
@@ -5596,6 +5598,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
array[DEVCONF_IOAM6_ID_WIDE] = cnf->ioam6_id_wide;
array[DEVCONF_NDISC_EVICT_NOCARRIER] = cnf->ndisc_evict_nocarrier;
array[DEVCONF_ACCEPT_UNTRACKED_NA] = cnf->accept_untracked_na;
+ array[DEVCONF_ACCEPT_RA_MIN_RTR_LFT] = cnf->accept_ra_min_rtr_lft;
}
static inline size_t inet6_ifla6_size(void)
@@ -6790,6 +6793,13 @@ static const struct ctl_table addrconf_sysctl[] = {
.proc_handler = proc_dointvec,
},
{
+ .procname = "accept_ra_min_rtr_lft",
+ .data = &ipv6_devconf.accept_ra_min_rtr_lft,
+ .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 18634ebd20a4..29ddad1c1a2f 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1280,6 +1280,8 @@ static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb)
if (!ndisc_parse_options(skb->dev, opt, optlen, &ndopts))
return SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS;
+ lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
+
if (!ipv6_accept_ra(in6_dev)) {
ND_PRINTK(2, info,
"RA: %s, did not accept ra for dev: %s\n",
@@ -1287,6 +1289,13 @@ static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb)
goto skip_linkparms;
}
+ if (lifetime != 0 && lifetime < in6_dev->cnf.accept_ra_min_rtr_lft) {
+ ND_PRINTK(2, info,
+ "RA: router lifetime (%ds) is too short: %s\n",
+ lifetime, skb->dev->name);
+ goto skip_linkparms;
+ }
+
#ifdef CONFIG_IPV6_NDISC_NODETYPE
/* skip link-specific parameters from interior routers */
if (skb->ndisc_nodetype == NDISC_NODETYPE_NODEFAULT) {
@@ -1339,8 +1348,6 @@ static enum skb_drop_reason ndisc_router_discovery(struct sk_buff *skb)
goto skip_defrtr;
}
- lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime);
-
#ifdef CONFIG_IPV6_ROUTER_PREF
pref = ra_msg->icmph.icmp6_router_pref;
/* 10b is handled as if it were 00b (medium) */
@@ -1492,6 +1499,13 @@ skip_linkparms:
goto out;
}
+ if (lifetime != 0 && lifetime < in6_dev->cnf.accept_ra_min_rtr_lft) {
+ ND_PRINTK(2, info,
+ "RA: router lifetime (%ds) is too short: %s\n",
+ lifetime, skb->dev->name);
+ goto out;
+ }
+
#ifdef CONFIG_IPV6_ROUTE_INFO
if (!in6_dev->cnf.accept_ra_from_local &&
ipv6_chk_addr(dev_net(in6_dev->dev), &ipv6_hdr(skb)->saddr,