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d5fdfe480c
Add a new selftest to verify netconsole's handling of messages that exceed the packet size limit and require fragmentation. The test sends messages with varying sizes and userdata, validating that: 1. Large messages are correctly fragmented and reassembled 2. Userdata fields are properly preserved across fragments 3. Messages work correctly with and without kernel release version appending The test creates a networking environment using netdevsim, sends messages through /dev/kmsg, and verifies the received fragments maintain message integrity. Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250203-netcons_frag_msgs-v1-1-5bc6bedf2ac0@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
122 lines
4 KiB
Bash
Executable file
122 lines
4 KiB
Bash
Executable file
#!/usr/bin/env bash
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# SPDX-License-Identifier: GPL-2.0
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# Test netconsole's message fragmentation functionality.
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#
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# When a message exceeds the maximum packet size, netconsole splits it into
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# multiple fragments for transmission. This test verifies:
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# - Correct fragmentation of large messages
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# - Proper reassembly of fragments at the receiver
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# - Preservation of userdata across fragments
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# - Behavior with and without kernel release version appending
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#
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# Author: Breno Leitao <leitao@debian.org>
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set -euo pipefail
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SCRIPTDIR=$(dirname "$(readlink -e "${BASH_SOURCE[0]}")")
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source "${SCRIPTDIR}"/lib/sh/lib_netcons.sh
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modprobe netdevsim 2> /dev/null || true
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modprobe netconsole 2> /dev/null || true
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# The content of kmsg will be save to the following file
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OUTPUT_FILE="/tmp/${TARGET}"
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# set userdata to a long value. In this case, it is "1-2-3-4...50-"
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USERDATA_VALUE=$(printf -- '%.2s-' {1..60})
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# Convert the header string in a regexp, so, we can remove
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# the second header as well.
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# A header looks like "13,468,514729715,-,ncfrag=0/1135;". If
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# release is appended, you might find something like:L
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# "6.13.0-04048-g4f561a87745a,13,468,514729715,-,ncfrag=0/1135;"
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function header_to_regex() {
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# header is everything before ;
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local HEADER="${1}"
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REGEX=$(echo "${HEADER}" | cut -d'=' -f1)
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echo "${REGEX}=[0-9]*\/[0-9]*;"
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}
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# We have two headers in the message. Remove both to get the full message,
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# and extract the full message.
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function extract_msg() {
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local MSGFILE="${1}"
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# Extract the header, which is the very first thing that arrives in the
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# first list.
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HEADER=$(sed -n '1p' "${MSGFILE}" | cut -d';' -f1)
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HEADER_REGEX=$(header_to_regex "${HEADER}")
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# Remove the two headers from the received message
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# This will return the message without any header, similarly to what
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# was sent.
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sed "s/""${HEADER_REGEX}""//g" "${MSGFILE}"
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}
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# Validate the message, which has two messages glued together.
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# unwrap them to make sure all the characters were transmitted.
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# File will look like the following:
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# 13,468,514729715,-,ncfrag=0/1135;<message>
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# key=<part of key>-13,468,514729715,-,ncfrag=967/1135;<rest of the key>
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function validate_fragmented_result() {
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# Discard the netconsole headers, and assemble the full message
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RCVMSG=$(extract_msg "${1}")
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# check for the main message
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if ! echo "${RCVMSG}" | grep -q "${MSG}"; then
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echo "Message body doesn't match." >&2
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echo "msg received=" "${RCVMSG}" >&2
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exit "${ksft_fail}"
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fi
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# check userdata
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if ! echo "${RCVMSG}" | grep -q "${USERDATA_VALUE}"; then
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echo "message userdata doesn't match" >&2
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echo "msg received=" "${RCVMSG}" >&2
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exit "${ksft_fail}"
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fi
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# test passed. hooray
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}
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# Check for basic system dependency and exit if not found
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check_for_dependencies
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# Set current loglevel to KERN_INFO(6), and default to KERN_NOTICE(5)
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echo "6 5" > /proc/sys/kernel/printk
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# Remove the namespace, interfaces and netconsole target on exit
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trap cleanup EXIT
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# Create one namespace and two interfaces
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set_network
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# Create a dynamic target for netconsole
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create_dynamic_target
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# Set userdata "key" with the "value" value
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set_user_data
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# TEST 1: Send message and userdata. They will fragment
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# =======
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MSG=$(printf -- 'MSG%.3s=' {1..150})
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# Listen for netconsole port inside the namespace and destination interface
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listen_port_and_save_to "${OUTPUT_FILE}" &
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# Wait for socat to start and listen to the port.
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wait_local_port_listen "${NAMESPACE}" "${PORT}" udp
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# Send the message
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echo "${MSG}: ${TARGET}" > /dev/kmsg
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# Wait until socat saves the file to disk
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busywait "${BUSYWAIT_TIMEOUT}" test -s "${OUTPUT_FILE}"
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# Check if the message was not corrupted
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validate_fragmented_result "${OUTPUT_FILE}"
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# TEST 2: Test with smaller message, and without release appended
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# =======
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MSG=$(printf -- 'FOOBAR%.3s=' {1..100})
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# Let's disable release and test again.
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disable_release_append
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listen_port_and_save_to "${OUTPUT_FILE}" &
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wait_local_port_listen "${NAMESPACE}" "${PORT}" udp
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echo "${MSG}: ${TARGET}" > /dev/kmsg
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busywait "${BUSYWAIT_TIMEOUT}" test -s "${OUTPUT_FILE}"
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validate_fragmented_result "${OUTPUT_FILE}"
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exit "${ksft_pass}"
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