kernel/include/net/if_inet6.h, branch linux-4.14.y

net, ipv6: convert ifacaddr6.aca_refcnt from atomic_t to refcount_t

2017-07-04T08:29:04Z

refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: David S. Miller

net, ipv6: convert ifmcaddr6.mca_refcnt from atomic_t to refcount_t

2017-07-04T08:29:04Z

net, ipv6: convert inet6_ifaddr.refcnt from atomic_t to refcount_t

2017-07-04T08:29:04Z

net, ipv6: convert inet6_dev.refcnt from atomic_t to refcount_t

2017-07-04T08:29:04Z

net/ipv6: allow sysctl to change link-local address generation mode

2017-01-27T15:25:34Z

The address generation mode for IPv6 link-local can only be configured by netlink messages. This patch adds the ability to change the address generation mode via sysctl. v1 -> v2 Removed the rtnl lock and switch to use RCU lock to iterate through the netdev list. v2 -> v3 Removed the addrgenmode variable from the idev structure and use the systcl storage for the flag. Simplifed the logic for sysctl handling by removing the supported for all operation. Added support for more types of tunnel interfaces for link-local address generation. Based the patches from net-next. v3 -> v4 Removed unnecessary whitespace changes. Signed-off-by: Felix Jia Signed-off-by: David S. Miller

ipv6 addrconf: Implemented enhanced DAD (RFC7527)

2016-12-04T04:21:37Z

Implemented RFC7527 Enhanced DAD. IPv6 duplicate address detection can fail if there is some temporary loopback of Ethernet frames. RFC7527 solves this by including a random nonce in the NS messages used for DAD, and if an NS is received with the same nonce it is assumed to be a looped back DAD probe and is ignored. RFC7527 is enabled by default. Can be disabled by setting both of conf/{all,interface}/enhanced_dad to zero. Signed-off-by: Erik Nordmark Signed-off-by: Bob Gilligan Reviewed-by: Hannes Frederic Sowa Signed-off-by: David S. Miller

IPv6: fix DESYNC_FACTOR

2016-10-14T14:59:15Z

The IPv6 temporary address generation uses a variable called DESYNC_FACTOR to prevent hosts updating the addresses at the same time. Quoting RFC 4941: ... The value DESYNC_FACTOR is a random value (different for each client) that ensures that clients don't synchronize with each other and generate new addresses at exactly the same time ... DESYNC_FACTOR is defined as: DESYNC_FACTOR -- A random value within the range 0 - MAX_DESYNC_FACTOR. It is computed once at system start (rather than each time it is used) and must never be greater than (TEMP_VALID_LIFETIME - REGEN_ADVANCE). First, I believe the RFC has a typo in it and meant to say: "and must never be greater than (TEMP_PREFERRED_LIFETIME - REGEN_ADVANCE)" The reason is that at various places in the RFC, DESYNC_FACTOR is used in a calculation like (TEMP_PREFERRED_LIFETIME - DESYNC_FACTOR) or (TEMP_PREFERRED_LIFETIME - REGEN_ADVANCE - DESYNC_FACTOR). It needs to be smaller than (TEMP_PREFERRED_LIFETIME - REGEN_ADVANCE) for the result of these calculations to be larger than zero. It's never used in a calculation together with TEMP_VALID_LIFETIME. I already submitted an errata to the rfc-editor: https://www.rfc-editor.org/errata_search.php?rfc=4941 The Linux implementation of DESYNC_FACTOR is very wrong: max_desync_factor is used in places DESYNC_FACTOR should be used. max_desync_factor is initialized to the RFC-recommended value for MAX_DESYNC_FACTOR (600) but the whole point is to get a _random_ value. And nothing ensures that the value used is not greater than (TEMP_PREFERRED_LIFETIME - REGEN_ADVANCE), which leads to underflows. The effect can easily be observed when setting the temp_prefered_lft sysctl e.g. to 60. The preferred lifetime of the temporary addresses will be bogus. TEMP_PREFERRED_LIFETIME and REGEN_ADVANCE are not constants and can be influenced by these three sysctls: regen_max_retry, dad_transmits and temp_prefered_lft. Thus, the upper bound for desync_factor needs to be re-calculated each time a new address is generated and if desync_factor is larger than the new upper bound, a new random value needs to be re-generated. And since we already have max_desync_factor configurable per interface, we also need to calculate and store desync_factor per interface. Signed-off-by: Jiri Bohac Signed-off-by: David S. Miller

IPv6: Drop the temporary address regen_timer

2016-10-14T14:59:15Z

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 Signed-off-by: David S. Miller

ipv6 addrconf: implement RFC7559 router solicitation backoff

2016-09-30T05:54:28Z

This implements: https://tools.ietf.org/html/rfc7559 Backoff is performed according to RFC3315 section 14: https://tools.ietf.org/html/rfc3315#section-14 We allow setting /proc/sys/net/ipv6/conf/*/router_solicitations to a negative value meaning an unlimited number of retransmits, and we make this the new default (inline with the RFC). We also add a new setting: /proc/sys/net/ipv6/conf/*/router_solicitation_max_interval defaulting to 1 hour (per RFC recommendation). Signed-off-by: Maciej Żenczykowski Acked-by: Erik Kline Signed-off-by: David S. Miller

ipv6: do retries on stable privacy addresses

2015-03-24T02:12:09Z

If a DAD conflict is detected, we want to retry privacy stable address generation up to idgen_retries (= 3) times with a delay of idgen_delay (= 1 second). Add the logic to addrconf_dad_failure. By design, we don't clean up dad failed permanent addresses. Cc: Erik Kline Cc: Fernando Gont Cc: Lorenzo Colitti Cc: YOSHIFUJI Hideaki/吉藤英明 Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller