kernel/net/ipv6/ndisc.c, branch linux-6.2.y

net: fix potential refcount leak in ndisc_router_discovery()

2022-08-15T10:40:28Z

The issue happens on specific paths in the function. After both the object `rt` and `neigh` are grabbed successfully, when `lifetime` is nonzero but the metric needs change, the function just deletes the route and set `rt` to NULL. Then, it may try grabbing `rt` and `neigh` again if above conditions hold. The function simply overwrite `neigh` if succeeds or returns if fails, without decreasing the reference count of previous `neigh`. This may result in memory leaks. Fix it by decrementing the reference count of `neigh` in place. Fixes: 6b2e04bc240f ("net: allow user to set metric on default route learned via Router Advertisement") Signed-off-by: Xin Xiong Signed-off-by: Xin Tan Signed-off-by: David S. Miller

net: ipv6: new accept_untracked_na option to accept na only if in-network

2022-07-16T01:55:50Z

This patch adds a third knob, '2', which extends the accept_untracked_na option to learn a neighbor only if the src ip is in the same subnet as an address configured on the interface that received the neighbor advertisement. This is similar to the arp_accept configuration for ipv4. Signed-off-by: Jaehee Park Suggested-by: Roopa Prabhu Signed-off-by: Jakub Kicinski

net, neigh: introduce interval_probe_time_ms for periodic probe

2022-06-30T11:14:35Z

commit ed6cd6a17896 ("net, neigh: Set lower cap for neigh_managed_work rearming") fixed a case when DELAY_PROBE_TIME is configured to 0, the processing of the system work queue hog CPU to 100%, and further more we should introduce a new option used by periodic probe Signed-off-by: Yuwei Wang Signed-off-by: Paolo Abeni

net/ipv6: Expand and rename accept_unsolicited_na to accept_untracked_na

2022-05-31T09:36:57Z

RFC 9131 changes default behaviour of handling RX of NA messages when the corresponding entry is absent in the neighbour cache. The current implementation is limited to accept just unsolicited NAs. However, the RFC is more generic where it also accepts solicited NAs. Both types should result in adding a STALE entry for this case. Expand accept_untracked_na behaviour to also accept solicited NAs to be compliant with the RFC and rename the sysctl knob to accept_untracked_na. Fixes: f9a2fb73318e ("net/ipv6: Introduce accept_unsolicited_na knob to implement router-side changes for RFC9131") Signed-off-by: Arun Ajith S Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20220530101414.65439-1-aajith@arista.com Signed-off-by: Paolo Abeni

net/ipv6: Introduce accept_unsolicited_na knob to implement router-side changes for RFC9131

2022-04-17T12:23:49Z

Add a new neighbour cache entry in STALE state for routers on receiving an unsolicited (gratuitous) neighbour advertisement with target link-layer-address option specified. This is similar to the arp_accept configuration for IPv4. A new sysctl endpoint is created to turn on this behaviour: /proc/sys/net/ipv6/conf/interface/accept_unsolicited_na. Signed-off-by: Arun Ajith S Reviewed-by: David Ahern Signed-off-by: David S. Miller

ipv6: separate ndisc_ns_create() from ndisc_send_ns()

2022-02-21T12:13:45Z

This patch separate NS message allocation steps from ndisc_send_ns(), so it could be used in other places, like bonding, to allocate and send IPv6 NS message. Also export ndisc_send_skb() and ndisc_ns_create() for later bonding usage. Signed-off-by: Hangbin Liu Signed-off-by: David S. Miller

Generate netlink notification when default IPv6 route preference changes

2022-02-14T11:15:37Z

Generate RTM_NEWROUTE netlink notification when the route preference changes on an existing kernel generated default route in response to RA messages. Currently netlink notifications are generated only when this route is added or deleted but not when the route preference changes, which can cause userspace routing application state to go out of sync with kernel. Signed-off-by: Kalash Nainwal Reviewed-by: David Ahern Signed-off-by: David S. Miller

net: ndisc: introduce ndisc_evict_nocarrier sysctl parameter

2021-11-02T02:57:14Z

In most situations the neighbor discovery cache should be cleared on a NOCARRIER event which is currently done unconditionally. But for wireless roams the neighbor discovery cache can and should remain intact since the underlying network has not changed. This patch introduces a sysctl option ndisc_evict_nocarrier which can be disabled by a wireless supplicant during a roam. This allows packets to be sent after a roam immediately without having to wait for neighbor discovery. A user reported roughly a 1 second delay after a roam before packets could be sent out (note, on IPv4). This delay was due to the ARP cache being cleared. During testing of this same scenario using IPv6 no delay was noticed, but regardless there is no reason to clear the ndisc cache for wireless roams. Signed-off-by: James Prestwood Reviewed-by: David Ahern Signed-off-by: Jakub Kicinski

ipv6: constify dev_addr passing

2021-10-13T16:40:46Z

In preparation for netdev->dev_addr being constant make all relevant arguments in ndisc constant. Signed-off-by: Jakub Kicinski

ipv6: add IFLA_INET6_RA_MTU to expose mtu value

2021-08-28T00:29:18Z

The kernel provides a "/proc/sys/net/ipv6/conf//mtu" file, which can temporarily record the mtu value of the last received RA message when the RA mtu value is lower than the interface mtu, but this proc has following limitations: (1) when the interface mtu (/sys/class/net//mtu) is updeated, mtu6 (/proc/sys/net/ipv6/conf//mtu) will be updated to the value of interface mtu; (2) mtu6 (/proc/sys/net/ipv6/conf//mtu) only affect ipv6 connection, and not affect ipv4. Therefore, when the mtu option is carried in the RA message, there will be a problem that the user sometimes cannot obtain RA mtu value correctly by reading mtu6. After this patch set, if a RA message carries the mtu option, you can send a netlink msg which nlmsg_type is RTM_GETLINK, and then by parsing the attribute of IFLA_INET6_RA_MTU to get the mtu value carried in the RA message received on the inet6 device. In addition, you can also get a link notification when ra_mtu is updated so it doesn't have to poll. In this way, if the MTU values that the device receives from the network in the PCO IPv4 and the RA IPv6 procedures are different, the user can obtain the correct ipv6 ra_mtu value and compare the value of ra_mtu and ipv4 mtu, then the device can use the lower MTU value for both IPv4 and IPv6. Signed-off-by: Rocco Yue Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20210827150412.9267-1-rocco.yue@mediatek.com Signed-off-by: Jakub Kicinski