linux-stable.git/include/linux/ipv6.h, branch v6.5.2

ipv6: remove hard coded limitation on ipv6_pinfo

2023-09-02T07:13:30+00:00

commit f5f80e32de12fad2813d37270e8364a03e6d3ef0 upstream.

IPv6 inet sockets are supposed to have a "struct ipv6_pinfo"
field at the end of their definition, so that inet6_sk_generic()
can derive from socket size the offset of the "struct ipv6_pinfo".

This is very fragile, and prevents adding bigger alignment
in sockets, because inet6_sk_generic() does not work
if the compiler adds padding after the ipv6_pinfo component.

We are currently working on a patch series to reorganize
TCP structures for better data locality and found issues
similar to the one fixed in commit f5d547676ca0
("tcp: fix tcp_inet6_sk() for 32bit kernels")

Alternative would be to force an alignment on "struct ipv6_pinfo",
greater or equal to __alignof__(any ipv6 sock) to ensure there is
no padding. This does not look great.

v2: fix typo in mptcp_proto_v6_init() (Paolo)

Signed-off-by: Eric Dumazet 
Cc: Chao Wu 
Cc: Wei Wang 
Cc: Coco Li 
Cc: YiFei Zhu 
Reviewed-by: Simon Horman 
Signed-off-by: David S. Miller 
Cc: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

ipv6: raw: preserve const qualifier in raw6_sk()

2023-03-18T12:23:33+00:00

We can change raw6_sk() to propagate its argument const qualifier,
thanks to container_of_const().

Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Signed-off-by: David S. Miller

net/ipv6: Expand and rename accept_unsolicited_na to accept_untracked_na

2022-05-31T09:36:57+00:00

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

ipv6: Add hop-by-hop header to jumbograms in ip6_output

2022-05-16T09:18:56+00:00

Instead of simply forcing a 0 payload_len in IPv6 header,
implement RFC 2675 and insert a custom extension header.

Note that only TCP stack is currently potentially generating
jumbograms, and that this extension header is purely local,
it wont be sent on a physical link.

This is needed so that packet capture (tcpdump and friends)
can properly dissect these large packets.

Signed-off-by: Coco Li 
Signed-off-by: Eric Dumazet 
Acked-by: Alexander Duyck 
Signed-off-by: David S. Miller

ipv6: Remove __ipv6_only_sock().

2022-04-22T11:47:50+00:00

Since commit 9fe516ba3fb2 ("inet: move ipv6only in sock_common"),
ipv6_only_sock() and __ipv6_only_sock() are the same macro.  Let's
remove the one.

Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller

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

2022-04-17T12:23:49+00:00

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: make mc_forwarding atomic

2022-02-05T15:20:34+00:00

This fixes minor data-races in ip6_mc_input() and
batadv_mcast_mla_rtr_flags_softif_get_ipv6()

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

ipv6: remove inet6_rsk() and tcp_twsk_ipv6only()

2022-01-27T13:53:27+00:00

The stubs under !CONFIG_IPV6 were missed when real functions
got deleted ca. v3.13.

Signed-off-by: Jakub Kicinski 
Signed-off-by: David S. Miller

icmp: ICMPV6: Examine invoking packet for Segment Route Headers.

2022-01-04T12:17:35+00:00

RFC8754 says:

ICMP error packets generated within the SR domain are sent to source
nodes within the SR domain.  The invoking packet in the ICMP error
message may contain an SRH.  Since the destination address of a packet
with an SRH changes as each segment is processed, it may not be the
destination used by the socket or application that generated the
invoking packet.

For the source of an invoking packet to process the ICMP error
message, the ultimate destination address of the IPv6 header may be
required.  The following logic is used to determine the destination
address for use by protocol-error handlers.

*  Walk all extension headers of the invoking IPv6 packet to the
   routing extension header preceding the upper-layer header.

   -  If routing header is type 4 Segment Routing Header (SRH)

      o  The SID at Segment List[0] may be used as the destination
         address of the invoking packet.

Mangle the skb so the network header points to the invoking packet
inside the ICMP packet. The seg6 helpers can then be used on the skb
to find any segment routing headers. If found, mark this fact in the
IPv6 control block of the skb, and store the offset into the packet of
the SRH. Then restore the skb back to its old state.

Signed-off-by: Andrew Lunn 
Reviewed-by: David Ahern 
Reviewed-by: Willem de Bruijn 
Signed-off-by: David S. Miller

net: ndisc: introduce ndisc_evict_nocarrier sysctl parameter

2021-11-02T02:57:14+00:00

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