net: add sysctl accept_ra_min_rtr_lft

commit 1671bcfd76fdc0b9e65153cf759153083755fe4c upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Patrick Rohr
2023-10-13 14:44:12 -07:00
committed by Greg Kroah-Hartman
parent 1ceaf0d3a8
commit 354a96770d
5 changed files with 42 additions and 2 deletions

View File

@@ -207,6 +207,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
.accept_ra_defrtr = 1,
.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 = {
.accept_ra_defrtr = 1,
.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,
@@ -5559,6 +5561,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
array[DEVCONF_DISABLE_POLICY] = cnf->disable_policy;
array[DEVCONF_NDISC_TCLASS] = cnf->ndisc_tclass;
array[DEVCONF_RPL_SEG_ENABLED] = cnf->rpl_seg_enabled;
array[DEVCONF_ACCEPT_RA_MIN_RTR_LFT] = cnf->accept_ra_min_rtr_lft;
}
static inline size_t inet6_ifla6_size(void)
@@ -6716,6 +6719,13 @@ static const struct ctl_table addrconf_sysctl[] = {
.mode = 0644,
.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,

View File

@@ -1222,6 +1222,8 @@ static void ndisc_router_discovery(struct sk_buff *skb)
return;
}
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",
@@ -1229,6 +1231,13 @@ static void 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) {
@@ -1281,8 +1290,6 @@ static void 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) */
@@ -1429,6 +1436,13 @@ 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,