Skip to content

Commit

Permalink
IPv6: Drop the temporary address regen_timer
Browse files Browse the repository at this point in the history 
The randomized interface identifier (rndid) was periodically updated from
the regen_timer timer. Simplify the code by updating the rndid only when
needed by ipv6_try_regen_rndid().

This makes the follow-up DESYNC_FACTOR fix much simpler.  Also it fixes a
reference counting error in this error path, where an in6_dev_put was
missing:
		err = addrconf_sysctl_register(ndev);
		if (err) {
			ipv6_mc_destroy_dev(ndev);
	-               del_timer(&ndev->regen_timer);
			snmp6_unregister_dev(ndev);
			goto err_release;

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
Jiri Bohac authored and David S. Miller committed Oct 14, 2016
1 parent fc791b6 commit 9d6280d
Show file tree
Hide file tree
Showing 2 changed files with 9 additions and 53 deletions.
1 change: 0 additions & 1 deletion include/net/if_inet6.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -191,7 +191,6 @@ struct inet6_dev {
int dead;

u8 rndid[8];
struct timer_list regen_timer;
struct list_head tempaddr_list;

struct in6_addr token;
Expand Down
61 changes: 9 additions & 52 deletions net/ipv6/addrconf.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -147,9 +147,8 @@ static inline void addrconf_sysctl_unregister(struct inet6_dev *idev)
}
#endif

static void __ipv6_regen_rndid(struct inet6_dev *idev);
static void __ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr);
static void ipv6_regen_rndid(unsigned long data);
static void ipv6_regen_rndid(struct inet6_dev *idev);
static void ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr);

static int ipv6_generate_eui64(u8 *eui, struct net_device *dev);
static int ipv6_count_addresses(struct inet6_dev *idev);
Expand Down Expand Up @@ -409,9 +408,7 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
goto err_release;
}

/* One reference from device. We must do this before
* we invoke __ipv6_regen_rndid().
*/
/* One reference from device. */
in6_dev_hold(ndev);

if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
Expand All @@ -425,17 +422,14 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
#endif

INIT_LIST_HEAD(&ndev->tempaddr_list);
setup_timer(&ndev->regen_timer, ipv6_regen_rndid, (unsigned long)ndev);
if ((dev->flags&IFF_LOOPBACK) ||
dev->type == ARPHRD_TUNNEL ||
dev->type == ARPHRD_TUNNEL6 ||
dev->type == ARPHRD_SIT ||
dev->type == ARPHRD_NONE) {
ndev->cnf.use_tempaddr = -1;
} else {
in6_dev_hold(ndev);
ipv6_regen_rndid((unsigned long) ndev);
}
} else
ipv6_regen_rndid(ndev);

ndev->token = in6addr_any;

Expand All @@ -447,7 +441,6 @@ static struct inet6_dev *ipv6_add_dev(struct net_device *dev)
err = addrconf_sysctl_register(ndev);
if (err) {
ipv6_mc_destroy_dev(ndev);
del_timer(&ndev->regen_timer);
snmp6_unregister_dev(ndev);
goto err_release;
}
Expand Down Expand Up @@ -1222,7 +1215,7 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, struct inet6_ifaddr *i
}
in6_ifa_hold(ifp);
memcpy(addr.s6_addr, ifp->addr.s6_addr, 8);
__ipv6_try_regen_rndid(idev, tmpaddr);
ipv6_try_regen_rndid(idev, tmpaddr);
memcpy(&addr.s6_addr[8], idev->rndid, 8);
age = (now - ifp->tstamp) / HZ;
tmp_valid_lft = min_t(__u32,
Expand Down Expand Up @@ -2150,7 +2143,7 @@ static int ipv6_inherit_eui64(u8 *eui, struct inet6_dev *idev)
}

/* (re)generation of randomized interface identifier (RFC 3041 3.2, 3.5) */
static void __ipv6_regen_rndid(struct inet6_dev *idev)
static void ipv6_regen_rndid(struct inet6_dev *idev)
{
regen:
get_random_bytes(idev->rndid, sizeof(idev->rndid));
Expand Down Expand Up @@ -2179,43 +2172,10 @@ static void __ipv6_regen_rndid(struct inet6_dev *idev)
}
}

static void ipv6_regen_rndid(unsigned long data)
{
struct inet6_dev *idev = (struct inet6_dev *) data;
unsigned long expires;

rcu_read_lock_bh();
write_lock_bh(&idev->lock);

if (idev->dead)
goto out;

__ipv6_regen_rndid(idev);

expires = jiffies +
idev->cnf.temp_prefered_lft * HZ -
idev->cnf.regen_max_retry * idev->cnf.dad_transmits *
NEIGH_VAR(idev->nd_parms, RETRANS_TIME) -
idev->cnf.max_desync_factor * HZ;
if (time_before(expires, jiffies)) {
pr_warn("%s: too short regeneration interval; timer disabled for %s\n",
__func__, idev->dev->name);
goto out;
}

if (!mod_timer(&idev->regen_timer, expires))
in6_dev_hold(idev);

out:
write_unlock_bh(&idev->lock);
rcu_read_unlock_bh();
in6_dev_put(idev);
}

static void __ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr)
static void ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpaddr)
{
if (tmpaddr && memcmp(idev->rndid, &tmpaddr->s6_addr[8], 8) == 0)
__ipv6_regen_rndid(idev);
ipv6_regen_rndid(idev);
}

/*
Expand Down Expand Up @@ -3594,9 +3554,6 @@ static int addrconf_ifdown(struct net_device *dev, int how)
if (!how)
idev->if_flags &= ~(IF_RS_SENT|IF_RA_RCVD|IF_READY);

if (how && del_timer(&idev->regen_timer))
in6_dev_put(idev);

/* Step 3: clear tempaddr list */
while (!list_empty(&idev->tempaddr_list)) {
ifa = list_first_entry(&idev->tempaddr_list,
Expand Down

0 comments on commit 9d6280d

Please sign in to comment.