diff mbox

[v2,3/7] ipv6 addrconf: rtr_solicits == -1 means unlimited

Message ID 1474797596-13320-3-git-send-email-zenczykowski@gmail.com
State Changes Requested, archived
Delegated to: David Miller
Headers show

Commit Message

Maciej Żenczykowski Sept. 25, 2016, 9:59 a.m. UTC 
From: Maciej Żenczykowski <maze@google.com>

This allows setting /proc/sys/net/ipv6/conf/*/router_solicitations
to -1 meaning an unlimited number of retransmits.

Signed-off-by: Maciej Żenczykowski <maze@google.com>
---
 net/ipv6/addrconf.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

Comments

Lorenzo Colitti Sept. 26, 2016, 3:34 p.m. UTC | #1 
On Sun, Sep 25, 2016 at 6:59 PM, Maciej Żenczykowski
<zenczykowski@gmail.com> wrote:
> +                 ifp->idev->cnf.rtr_solicits != 0 &&

Given that some of this patch checks for == -1, and some of it checks
for != 0... is it possible that setting the value to something
unexpected like -3 will cause any issues to the stack? (Other than
just rendering IPv6 unusable on this interface, which seems like a
given.)
Maciej Żenczykowski Sept. 27, 2016, 2:23 a.m. UTC | #2 
> Given that some of this patch checks for == -1, and some of it checks
> for != 0... is it possible that setting the value to something
> unexpected like -3 will cause any issues to the stack? (Other than
> just rendering IPv6 unusable on this interface, which seems like a
> given.)

You shouldn't be able to set it to -3, that's what the extra1 is for...
Erik Kline Sept. 27, 2016, 2:25 a.m. UTC | #3 
On 27 September 2016 at 11:23, Maciej Żenczykowski
<zenczykowski@gmail.com> wrote:
>> Given that some of this patch checks for == -1, and some of it checks
>> for != 0... is it possible that setting the value to something
>> unexpected like -3 will cause any issues to the stack? (Other than
>> just rendering IPv6 unusable on this interface, which seems like a
>> given.)
>
> You shouldn't be able to set it to -3, that's what the extra1 is for...

the proc_dointvec_minmax reference with &minus_one means you shouldn't
be able to set it below -1.
diff mbox

Patch

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 3a835495fb53..6c63bf06fbcf 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3687,7 +3687,7 @@  static void addrconf_rs_timer(unsigned long data)
 	if (idev->if_flags & IF_RA_RCVD)
 		goto out;
 
-	if (idev->rs_probes++ < idev->cnf.rtr_solicits) {
+	if (idev->rs_probes++ < idev->cnf.rtr_solicits || idev->cnf.rtr_solicits == -1) {
 		write_unlock(&idev->lock);
 		if (!ipv6_get_lladdr(dev, &lladdr, IFA_F_TENTATIVE))
 			ndisc_send_rs(dev, &lladdr,
@@ -3949,7 +3949,7 @@  static void addrconf_dad_completed(struct inet6_ifaddr *ifp)
 	send_mld = ifp->scope == IFA_LINK && ipv6_lonely_lladdr(ifp);
 	send_rs = send_mld &&
 		  ipv6_accept_ra(ifp->idev) &&
-		  ifp->idev->cnf.rtr_solicits > 0 &&
+		  ifp->idev->cnf.rtr_solicits != 0 &&
 		  (dev->flags&IFF_LOOPBACK) == 0;
 	read_unlock_bh(&ifp->idev->lock);
 
@@ -5099,7 +5099,7 @@  static int inet6_set_iftoken(struct inet6_dev *idev, struct in6_addr *token)
 		return -EINVAL;
 	if (!ipv6_accept_ra(idev))
 		return -EINVAL;
-	if (idev->cnf.rtr_solicits <= 0)
+	if (idev->cnf.rtr_solicits == 0)
 		return -EINVAL;
 
 	write_lock_bh(&idev->lock);
@@ -5699,6 +5699,7 @@  int addrconf_sysctl_ignore_routes_with_linkdown(struct ctl_table *ctl,
 	return ret;
 }
 
+static int minus_one = -1;
 static int one = 1;
 static int two_five_five = 255;
 
@@ -5759,7 +5760,8 @@  static const struct ctl_table addrconf_sysctl[] = {
 		.data		= &ipv6_devconf.rtr_solicits,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &minus_one,
 	},
 	{
 		.procname	= "router_solicitation_interval",