Files
linux/tools/testing/selftests/net/.gitignore
Danielle Ratson d07d7c3dd9 selftests: net: Add kernel selftest for RFC 4884
RFC 4884 extended certain ICMP messages with a length attribute that
encodes the length of the "original datagram" field. This is needed so
that new information could be appended to these messages without
applications thinking that it is part of the "original datagram" field.

In version 5.9, the kernel was extended with two new socket options
(SOL_IP/IP_RECVERR_4884 and SOL_IPV6/IPV6_RECVERR_RFC4884) that allow
user space to retrieve this length which is basically the offset to the
ICMP Extension Structure at the end of the ICMP message. This is
required by user space applications that need to parse the information
contained in the ICMP Extension Structure. For example, the RFC 5837
extension for tracepath.

Add a selftest that verifies correct handling of the RFC 4884 length
field for both IPv4 and IPv6, with and without extension structures,
and validates that malformed extensions are correctly reported as invalid.

For each address family, the test creates:
  - a raw socket used to send locally crafted ICMP error packets to the
    loopback address, and
  - a datagram socket used to receive the encapsulated original datagram
    and associated error metadata from the kernel error queue.

ICMP packets are constructed entirely in user space rather than relying
on kernel-generated errors. This allows the test to exercise invalid
scenarios (such as corrupted checksums and incorrect length fields) and
verify that the SO_EE_RFC4884_FLAG_INVALID flag is set as expected.

Output Example:

$ ./icmp_rfc4884
Starting 18 tests from 18 test cases.
  RUN           rfc4884.ipv4_ext_small_payload.rfc4884 ...
            OK  rfc4884.ipv4_ext_small_payload.rfc4884
ok 1 rfc4884.ipv4_ext_small_payload.rfc4884
  RUN           rfc4884.ipv4_ext.rfc4884 ...
            OK  rfc4884.ipv4_ext.rfc4884
ok 2 rfc4884.ipv4_ext.rfc4884
  RUN           rfc4884.ipv4_ext_large_payload.rfc4884 ...
            OK  rfc4884.ipv4_ext_large_payload.rfc4884
ok 3 rfc4884.ipv4_ext_large_payload.rfc4884
  RUN           rfc4884.ipv4_no_ext_small_payload.rfc4884 ...
            OK  rfc4884.ipv4_no_ext_small_payload.rfc4884
ok 4 rfc4884.ipv4_no_ext_small_payload.rfc4884
  RUN           rfc4884.ipv4_no_ext_min_payload.rfc4884 ...
            OK  rfc4884.ipv4_no_ext_min_payload.rfc4884
ok 5 rfc4884.ipv4_no_ext_min_payload.rfc4884
  RUN           rfc4884.ipv4_no_ext_large_payload.rfc4884 ...
            OK  rfc4884.ipv4_no_ext_large_payload.rfc4884
ok 6 rfc4884.ipv4_no_ext_large_payload.rfc4884
  RUN           rfc4884.ipv4_invalid_ext_checksum.rfc4884 ...
            OK  rfc4884.ipv4_invalid_ext_checksum.rfc4884
ok 7 rfc4884.ipv4_invalid_ext_checksum.rfc4884
  RUN           rfc4884.ipv4_invalid_ext_length_small.rfc4884 ...
            OK  rfc4884.ipv4_invalid_ext_length_small.rfc4884
ok 8 rfc4884.ipv4_invalid_ext_length_small.rfc4884
  RUN           rfc4884.ipv4_invalid_ext_length_large.rfc4884 ...
            OK  rfc4884.ipv4_invalid_ext_length_large.rfc4884
ok 9 rfc4884.ipv4_invalid_ext_length_large.rfc4884
  RUN           rfc4884.ipv6_ext_small_payload.rfc4884 ...
            OK  rfc4884.ipv6_ext_small_payload.rfc4884
ok 10 rfc4884.ipv6_ext_small_payload.rfc4884
  RUN           rfc4884.ipv6_ext.rfc4884 ...
            OK  rfc4884.ipv6_ext.rfc4884
ok 11 rfc4884.ipv6_ext.rfc4884
  RUN           rfc4884.ipv6_ext_large_payload.rfc4884 ...
            OK  rfc4884.ipv6_ext_large_payload.rfc4884
ok 12 rfc4884.ipv6_ext_large_payload.rfc4884
  RUN           rfc4884.ipv6_no_ext_small_payload.rfc4884 ...
            OK  rfc4884.ipv6_no_ext_small_payload.rfc4884
ok 13 rfc4884.ipv6_no_ext_small_payload.rfc4884
  RUN           rfc4884.ipv6_no_ext_min_payload.rfc4884 ...
            OK  rfc4884.ipv6_no_ext_min_payload.rfc4884
ok 14 rfc4884.ipv6_no_ext_min_payload.rfc4884
  RUN           rfc4884.ipv6_no_ext_large_payload.rfc4884 ...
            OK  rfc4884.ipv6_no_ext_large_payload.rfc4884
ok 15 rfc4884.ipv6_no_ext_large_payload.rfc4884
  RUN           rfc4884.ipv6_invalid_ext_checksum.rfc4884 ...
            OK  rfc4884.ipv6_invalid_ext_checksum.rfc4884
ok 16 rfc4884.ipv6_invalid_ext_checksum.rfc4884
  RUN           rfc4884.ipv6_invalid_ext_length_small.rfc4884 ...
            OK  rfc4884.ipv6_invalid_ext_length_small.rfc4884
ok 17 rfc4884.ipv6_invalid_ext_length_small.rfc4884
  RUN           rfc4884.ipv6_invalid_ext_length_large.rfc4884 ...
            OK  rfc4884.ipv6_invalid_ext_length_large.rfc4884
ok 18 rfc4884.ipv6_invalid_ext_length_large.rfc4884
 PASSED: 18 / 18 tests passed.
 Totals: pass:18 fail:0 xfail:0 xpass:0 skip:0 error:0

Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260121114644.2863640-1-danieller@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-22 18:29:49 -08:00

61 lines
855 B
Plaintext

# SPDX-License-Identifier: GPL-2.0-only
bind_bhash
bind_timewait
bind_wildcard
busy_poller
cmsg_sender
epoll_busy_poll
fin_ack_lat
hwtstamp_config
icmp_rfc4884
io_uring_zerocopy_tx
ioam6_parser
ip_defrag
ip_local_port_range
ipsec
ipv6_flowlabel
ipv6_flowlabel_mgr
ipv6_fragmentation
log.txt
msg_zerocopy
netlink-dumps
nettest
proc_net_pktgen
psock_fanout
psock_snd
psock_tpacket
reuseaddr_conflict
reuseaddr_ports_exhausted
reuseport_addr_any
reuseport_bpf
reuseport_bpf_cpu
reuseport_bpf_numa
reuseport_dualstack
rxtimestamp
sctp_hello
sk_bind_sendto_listen
sk_connect_zero_addr
sk_so_peek_off
skf_net_off
socket
so_incoming_cpu
so_netns_cookie
so_txtime
so_rcv_listener
stress_reuseport_listen
tap
tcp_fastopen_backup_key
tcp_inq
tcp_mmap
tcp_port_share
tfo
timestamping
tls
tools
tun
txring_overwrite
txtimestamp
udpgso
udpgso_bench_rx
udpgso_bench_tx