linux.git/include/net/ipv6.h, branch v7.1-rc2 Linux kernel source tree bpf: remove ipv6_bpf_stub completely and use direct function calls 2026-03-29T18:21:24+00:00 Fernando Fernandez Mancera fmancera@suse.de 2026-03-25T12:08:50+00:00 ad84b1eefe28cee96c572b84bfa4f0fbfd425b68 As IPv6 is built-in only, the ipv6_bpf_stub can be removed completely. Convert all ipv6_bpf_stub usage to direct function calls instead. The fallback functions introduced previously will prevent linkage errors when CONFIG_IPV6 is disabled. Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Tested-by: Ricardo B. Marlière <rbm@suse.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://patch.msgid.link/20260325120928.15848-10-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
As IPv6 is built-in only, the ipv6_bpf_stub can be removed completely.

Convert all ipv6_bpf_stub usage to direct function calls instead. The
fallback functions introduced previously will prevent linkage errors
when CONFIG_IPV6 is disabled.

Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Tested-by: Ricardo B. Marlière <rbm@suse.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20260325120928.15848-10-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ipv6: prepare headers for ipv6_stub removal 2026-03-29T18:21:23+00:00 Fernando Fernandez Mancera fmancera@suse.de 2026-03-25T12:08:46+00:00 4b70b20215049472f200ed563a7a0d44a7188fd3 In preparation for dropping ipv6_stub and converting its users to direct function calls, introduce static inline dummy functions and fallback macros in the IPv6 networking headers. In addition, introduce checks on fib6_nh_init(), ip6_dst_lookup_flow() and ip6_fragment() to avoid a crash due to ipv6.disable=1 set during booting. The other functions are safe as they cannot be called with ipv6.disable=1 set. These fallbacks ensure that when CONFIG_IPV6 is completely disabled, there are no compiling or linking errors due to code paths not guarded by preprocessor macro IS_ENABLED(CONFIG_IPV6). In addition, export ndisc_send_na(), ip6_route_input() and ip6_fragment(). Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Tested-by: Ricardo B. Marlière <rbm@suse.com> Link: https://patch.msgid.link/20260325120928.15848-6-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
In preparation for dropping ipv6_stub and converting its users to direct
function calls, introduce static inline dummy functions and fallback
macros in the IPv6 networking headers. In addition, introduce checks on
fib6_nh_init(), ip6_dst_lookup_flow() and ip6_fragment() to avoid a
crash due to ipv6.disable=1 set during booting. The other functions are
safe as they cannot be called with ipv6.disable=1 set.

These fallbacks ensure that when CONFIG_IPV6 is completely disabled,
there are no compiling or linking errors due to code paths not guarded
by preprocessor macro IS_ENABLED(CONFIG_IPV6).

In addition, export ndisc_send_na(), ip6_route_input() and
ip6_fragment().

Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Tested-by: Ricardo B. Marlière <rbm@suse.com>
Link: https://patch.msgid.link/20260325120928.15848-6-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ipv6: Retire UDP-Lite. 2026-03-14T01:57:44+00:00 Kuniyuki Iwashima kuniyu@google.com 2026-03-11T05:19:49+00:00 62554a51c5844feebe0466d8b31980e110b481de As announced in commit be28c14ac8bb ("udplite: Print deprecation notice."), it's time to deprecate UDP-Lite. As a first step, let's drop support for IPv6 UDP-Lite sockets. We will remove the remaining dead code gradually. Along with the removal of udplite.c, most of the functions exposed via udp_impl.h are made static. The prototypes of udpv6_sendmsg() and udpv6_recvmsg() are moved to udp.h, but only udpv6_recvmsg() has INDIRECT_CALLABLE_DECLARE() because udpv6_sendmsg() is exported for rxrpc since commit ed472b0c8783 ("rxrpc: Call udp_sendmsg() directly"). Also, udpv6_recvmsg() needs INDIRECT_CALLABLE_SCOPE for CONFIG_MITIGATION_RETPOLINE=n. Note that udplite.h is included temporarily for udplite_csum(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260311052020.1213705-3-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
As announced in commit be28c14ac8bb ("udplite: Print deprecation
notice."), it's time to deprecate UDP-Lite.

As a first step, let's drop support for IPv6 UDP-Lite sockets.

We will remove the remaining dead code gradually.

Along with the removal of udplite.c, most of the functions exposed
via udp_impl.h are made static.

The prototypes of udpv6_sendmsg() and udpv6_recvmsg() are moved
to udp.h, but only udpv6_recvmsg() has INDIRECT_CALLABLE_DECLARE()
because udpv6_sendmsg() is exported for rxrpc since commit ed472b0c8783
("rxrpc: Call udp_sendmsg() directly").

Also, udpv6_recvmsg() needs INDIRECT_CALLABLE_SCOPE for
CONFIG_MITIGATION_RETPOLINE=n.

Note that udplite.h is included temporarily for udplite_csum().

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260311052020.1213705-3-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: remove addr_len argument of recvmsg() handlers 2026-03-03T02:17:17+00:00 Eric Dumazet edumazet@google.com 2026-02-27T15:11:20+00:00 8341c989ac77d712c7d6e2bce29e8a4bcb2eeae4 Use msg->msg_namelen as a place holder instead of a temporary variable, notably in inet[6]_recvmsg(). This removes stack canaries and allows tail-calls. $ scripts/bloat-o-meter -t vmlinux.old vmlinux add/remove: 0/0 grow/shrink: 2/19 up/down: 26/-532 (-506) Function old new delta rawv6_recvmsg 744 767 +23 vsock_dgram_recvmsg 55 58 +3 vsock_connectible_recvmsg 50 47 -3 unix_stream_recvmsg 161 158 -3 unix_seqpacket_recvmsg 62 59 -3 unix_dgram_recvmsg 42 39 -3 tcp_recvmsg 546 543 -3 mptcp_recvmsg 1568 1565 -3 ping_recvmsg 806 800 -6 tcp_bpf_recvmsg_parser 983 974 -9 ip_recv_error 588 576 -12 ipv6_recv_rxpmtu 442 428 -14 udp_recvmsg 1243 1224 -19 ipv6_recv_error 1046 1024 -22 udpv6_recvmsg 1487 1461 -26 raw_recvmsg 465 437 -28 udp_bpf_recvmsg 1027 984 -43 sock_common_recvmsg 103 27 -76 inet_recvmsg 257 175 -82 inet6_recvmsg 257 175 -82 tcp_bpf_recvmsg 663 568 -95 Total: Before=25143834, After=25143328, chg -0.00% Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260227151120.1346573-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Use msg->msg_namelen as a place holder instead of a
temporary variable, notably in inet[6]_recvmsg().

This removes stack canaries and allows tail-calls.

$ scripts/bloat-o-meter -t vmlinux.old vmlinux
add/remove: 0/0 grow/shrink: 2/19 up/down: 26/-532 (-506)
Function                                     old     new   delta
rawv6_recvmsg                                744     767     +23
vsock_dgram_recvmsg                           55      58      +3
vsock_connectible_recvmsg                     50      47      -3
unix_stream_recvmsg                          161     158      -3
unix_seqpacket_recvmsg                        62      59      -3
unix_dgram_recvmsg                            42      39      -3
tcp_recvmsg                                  546     543      -3
mptcp_recvmsg                               1568    1565      -3
ping_recvmsg                                 806     800      -6
tcp_bpf_recvmsg_parser                       983     974      -9
ip_recv_error                                588     576     -12
ipv6_recv_rxpmtu                             442     428     -14
udp_recvmsg                                 1243    1224     -19
ipv6_recv_error                             1046    1024     -22
udpv6_recvmsg                               1487    1461     -26
raw_recvmsg                                  465     437     -28
udp_bpf_recvmsg                             1027     984     -43
sock_common_recvmsg                          103      27     -76
inet_recvmsg                                 257     175     -82
inet6_recvmsg                                257     175     -82
tcp_bpf_recvmsg                              663     568     -95
Total: Before=25143834, After=25143328, chg -0.00%

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260227151120.1346573-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ipv6: fix a race in ip6_sock_set_v6only() 2026-02-18T00:45:29+00:00 Eric Dumazet edumazet@google.com 2026-02-16T10:22:02+00:00 452a3eee22c57a5786ae6db5c97f3b0ec13bb3b7 It is unlikely that this function will be ever called with isk->inet_num being not zero. Perform the check on isk->inet_num inside the locked section for complete safety. Fixes: 9b115749acb24 ("ipv6: add ip6_sock_set_v6only") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Link: https://patch.msgid.link/20260216102202.3343588-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
It is unlikely that this function will be ever called
with isk->inet_num being not zero.

Perform the check on isk->inet_num inside the locked section
for complete safety.

Fixes: 9b115749acb24 ("ipv6: add ip6_sock_set_v6only")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Link: https://patch.msgid.link/20260216102202.3343588-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/ipv6: Remove HBH helpers 2026-02-07T04:50:13+00:00 Alice Mikityanska alice@isovalent.com 2026-02-05T13:39:25+00:00 35f66ce900370ed0eab6553977adc0a2fb9cccfb Now that the HBH jumbo helpers are not used by any driver or GSO, remove them altogether. Signed-off-by: Alice Mikityanska <alice@isovalent.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260205133925.526371-13-alice.kernel@fastmail.im Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Now that the HBH jumbo helpers are not used by any driver or GSO, remove
them altogether.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260205133925.526371-13-alice.kernel@fastmail.im
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/ipv6: Introduce payload_len helpers 2026-02-07T04:50:03+00:00 Alice Mikityanska alice@isovalent.com 2026-02-05T13:39:14+00:00 b2936b4fd56294e49d6c8e9152ea6c4982757c7d The next commits will transition away from using the hop-by-hop extension header to encode packet length for BIG TCP. Add wrappers around ip6->payload_len that return the actual value if it's non-zero, and calculate it from skb->len if payload_len is set to zero (and a symmetrical setter). The new helpers are used wherever the surrounding code supports the hop-by-hop jumbo header for BIG TCP IPv6, or the corresponding IPv4 code uses skb_ip_totlen (e.g., in include/net/netfilter/nf_tables_ipv6.h). No behavioral change in this commit. Signed-off-by: Alice Mikityanska <alice@isovalent.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260205133925.526371-2-alice.kernel@fastmail.im Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
The next commits will transition away from using the hop-by-hop
extension header to encode packet length for BIG TCP. Add wrappers
around ip6->payload_len that return the actual value if it's non-zero,
and calculate it from skb->len if payload_len is set to zero (and a
symmetrical setter).

The new helpers are used wherever the surrounding code supports the
hop-by-hop jumbo header for BIG TCP IPv6, or the corresponding IPv4 code
uses skb_ip_totlen (e.g., in include/net/netfilter/nf_tables_ipv6.h).

No behavioral change in this commit.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260205133925.526371-2-alice.kernel@fastmail.im
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ipv6: colocate inet6_cork in inet_cork_full 2026-02-03T01:49:30+00:00 Eric Dumazet edumazet@google.com 2026-01-30T21:03:03+00:00 b409a7f7176bb8fc0002b8592d14b11ebe481b1d All inet6_cork users also use one inet_cork_full. Reduce number of parameters and increase data locality. This saves ~275 bytes of code on x86_64. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260130210303.3888261-9-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
All inet6_cork users also use one inet_cork_full.

Reduce number of parameters and increase data locality.

This saves ~275 bytes of code on x86_64.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260130210303.3888261-9-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ipv6: pass proto by value to ipv6_push_nfrag_opts() and ipv6_push_frag_opts() 2026-02-03T01:49:28+00:00 Eric Dumazet edumazet@google.com 2026-01-30T21:02:56+00:00 1bc46dd209667346c5aa56c351995e7c260696d0 With CONFIG_STACKPROTECTOR_STRONG=y, it is better to avoid passing a pointer to an automatic variable. Change these exported functions to return 'u8 proto' instead of void. - ipv6_push_nfrag_opts() - ipv6_push_frag_opts() For instance, replace ipv6_push_frag_opts(skb, opt, &proto); with: proto = ipv6_push_frag_opts(skb, opt, proto); Note that even after this change, ip6_xmit() has to use a stack canary because of @first_hop variable. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260130210303.3888261-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
With CONFIG_STACKPROTECTOR_STRONG=y, it is better to avoid passing
a pointer to an automatic variable.

Change these exported functions to return 'u8 proto'
instead of void.

- ipv6_push_nfrag_opts()
- ipv6_push_frag_opts()

For instance, replace
	ipv6_push_frag_opts(skb, opt, &proto);
with:
	proto = ipv6_push_frag_opts(skb, opt, proto);

Note that even after this change, ip6_xmit() has to use a stack canary
because of @first_hop variable.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260130210303.3888261-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ipv6: optimize fl6_update_dst() 2026-01-30T02:47:21+00:00 Eric Dumazet edumazet@google.com 2026-01-28T18:55:47+00:00 b1cd687e3e387aafde03ae3d862ef44410131ae4 fl6_update_dst() is called for every TCP (and others) transmit, and is a nop for common cases. Split it in two parts : 1) fl6_update_dst() inline helper, small and fast. 2) __fl6_update_dst() for the exception, out of line. Small size increase to get better TX performance. $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new add/remove: 2/2 grow/shrink: 8/0 up/down: 296/-125 (171) Function old new delta __fl6_update_dst - 104 +104 rawv6_sendmsg 2244 2284 +40 udpv6_sendmsg 3013 3043 +30 tcp_v6_connect 1514 1534 +20 cookie_v6_check 1501 1519 +18 ip6_datagram_dst_update 673 690 +17 inet6_sk_rebuild_header 499 516 +17 inet6_csk_route_socket 507 524 +17 inet6_csk_route_req 343 360 +17 __pfx___fl6_update_dst - 16 +16 __pfx_fl6_update_dst 16 - -16 fl6_update_dst 109 - -109 Total: Before=22570304, After=22570475, chg +0.00% Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260128185548.3738781-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
fl6_update_dst() is called for every TCP (and others) transmit,
and is a nop for common cases.

Split it in two parts :

1) fl6_update_dst() inline helper, small and fast.

2) __fl6_update_dst() for the exception, out of line.

Small size increase to get better TX performance.

$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 2/2 grow/shrink: 8/0 up/down: 296/-125 (171)
Function                                     old     new   delta
__fl6_update_dst                               -     104    +104
rawv6_sendmsg                               2244    2284     +40
udpv6_sendmsg                               3013    3043     +30
tcp_v6_connect                              1514    1534     +20
cookie_v6_check                             1501    1519     +18
ip6_datagram_dst_update                      673     690     +17
inet6_sk_rebuild_header                      499     516     +17
inet6_csk_route_socket                       507     524     +17
inet6_csk_route_req                          343     360     +17
__pfx___fl6_update_dst                         -      16     +16
__pfx_fl6_update_dst                          16       -     -16
fl6_update_dst                               109       -    -109
Total: Before=22570304, After=22570475, chg +0.00%

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260128185548.3738781-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>