Commit df3bc662 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch... 

Merge branch 'net-ipv6-addrconf-ensure-that-temporary-addresses-preferred-lifetimes-are-in-the-valid-range'

Alex Henrie says:

====================
net: ipv6/addrconf: ensure that temporary addresses' preferred lifetimes are in the valid range

No changes from v2, but there are only four patches now because the
first patch has already been applied.

https://lore.kernel.org/all/20230829054623.104293-1-alexhenrie24@gmail.com/
====================

Link: https://lore.kernel.org/r/20231024212312.299370-1-alexhenrie24@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents d8c4ef76 ec575f88

Documentation/networking/ip-sysctl.rst

+8 −2
Original line number Diff line number Diff line
@@ -2502,12 +2502,18 @@ use_tempaddr - INTEGER 
		* -1 (for point-to-point devices and loopback devices)



temp_valid_lft - INTEGER

	valid lifetime (in seconds) for temporary addresses.

	valid lifetime (in seconds) for temporary addresses. If less than the

	minimum required lifetime (typically 5 seconds), temporary addresses

	will not be created.



	Default: 172800 (2 days)



temp_prefered_lft - INTEGER

	Preferred lifetime (in seconds) for temporary addresses.

	Preferred lifetime (in seconds) for temporary addresses. If

	temp_prefered_lft is less than the minimum required lifetime (typically

	5 seconds), the preferred lifetime is the minimum required. If

	temp_prefered_lft is greater than temp_valid_lft, the preferred lifetime

	is temp_valid_lft.



	Default: 86400 (1 day)

net/ipv6/addrconf.c

+14 −5
Original line number Diff line number Diff line
@@ -1399,6 +1399,7 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, bool block) 
			      idev->cnf.temp_valid_lft + age);

	cfg.preferred_lft = cnf_temp_preferred_lft + age - idev->desync_factor;

	cfg.preferred_lft = min_t(__u32, ifp->prefered_lft, cfg.preferred_lft);

	cfg.preferred_lft = min_t(__u32, cfg.valid_lft, cfg.preferred_lft);



	cfg.plen = ifp->prefix_len;

	tmp_tstamp = ifp->tstamp;
@@ -1406,15 +1407,23 @@ static int ipv6_create_tempaddr(struct inet6_ifaddr *ifp, bool block) 


	write_unlock_bh(&idev->lock);



	/* A temporary address is created only if this calculated Preferred

	 * Lifetime is greater than REGEN_ADVANCE time units.  In particular,

	 * an implementation must not create a temporary address with a zero

	 * Preferred Lifetime.

	/* From RFC 4941:

	 *

	 *     A temporary address is created only if this calculated Preferred

	 *     Lifetime is greater than REGEN_ADVANCE time units.  In

	 *     particular, an implementation must not create a temporary address

	 *     with a zero Preferred Lifetime.

	 *

	 * Clamp the preferred lifetime to a minimum of regen_advance, unless

	 * that would exceed valid_lft.

	 *

	 * Use age calculation as in addrconf_verify to avoid unnecessary

	 * temporary addresses being generated.

	 */

	age = (now - tmp_tstamp + ADDRCONF_TIMER_FUZZ_MINUS) / HZ;

	if (cfg.preferred_lft <= regen_advance + age) {

	if (cfg.preferred_lft <= regen_advance + age)

		cfg.preferred_lft = regen_advance + age + 1;

	if (cfg.preferred_lft > cfg.valid_lft) {

		in6_ifa_put(ifp);

		in6_dev_put(idev);

		ret = -1;