From: Petr Machata <petrm@nvidia.com> To: "David S. Miller" <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>, Roopa Prabhu <roopa@nvidia.com>, Nikolay Aleksandrov <razor@blackwall.org>, <netdev@vger.kernel.org> Cc: <bridge@lists.linux-foundation.org>, Petr Machata <petrm@nvidia.com>, "Ido Schimmel" <idosch@nvidia.com> Subject: [PATCH net-next v3 12/16] selftests: forwarding: lib: Add helpers for checksum handling Date: Thu, 2 Feb 2023 18:59:30 +0100 [thread overview] Message-ID: <3a152b0cf376dc1defd99d7aa78da1b409e31f4d.1675359453.git.petrm@nvidia.com> (raw) In-Reply-To: <cover.1675359453.git.petrm@nvidia.com> In order to generate IGMPv3 and MLDv2 packets on the fly, we will need helpers to calculate the packet checksum. The approach presented in this patch revolves around payload templates for mausezahn. These are mausezahn-like payload strings (01:23:45:...) with possibly one 2-byte sequence replaced with the word PAYLOAD. The main function is payload_template_calc_checksum(), which calculates RFC 1071 checksum of the message. There are further helpers to then convert the checksum to the payload format, and to expand it. For IPv6, MLDv2 message checksum is computed using a pseudoheader that differs from the header used in the payload itself. The fact that the two messages are different means that the checksum needs to be returned as a separate quantity, instead of being expanded in-place in the payload itself. Furthermore, the pseudoheader includes a length of the message. Much like the checksum, this needs to be expanded in mausezahn format. And likewise for number of addresses for (S,G) entries. Thus we have several places where a computed quantity needs to be presented in the payload format. Add a helper u16_to_bytes(), which will be used in all these cases. Signed-off-by: Petr Machata <petrm@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> --- Notes: v2: - In the comment at payload_template_calc_checksum(), s/%#02x/%02x/, that's the mausezahn payload format. tools/testing/selftests/net/forwarding/lib.sh | 56 +++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/tools/testing/selftests/net/forwarding/lib.sh b/tools/testing/selftests/net/forwarding/lib.sh index 409ff3799b55..b10c903d9abd 100755 --- a/tools/testing/selftests/net/forwarding/lib.sh +++ b/tools/testing/selftests/net/forwarding/lib.sh @@ -1730,6 +1730,62 @@ ipv6_to_bytes() expand_ipv6 "$IP" : } +u16_to_bytes() +{ + local u16=$1; shift + + printf "%04x" $u16 | sed 's/^/000/;s/^.*\(..\)\(..\)$/\1:\2/' +} + +# Given a mausezahn-formatted payload (colon-separated bytes given as %02x), +# possibly with a keyword CHECKSUM stashed where a 16-bit checksum should be, +# calculate checksum as per RFC 1071, assuming the CHECKSUM field (if any) +# stands for 00:00. +payload_template_calc_checksum() +{ + local payload=$1; shift + + ( + # Set input radix. + echo "16i" + # Push zero for the initial checksum. + echo 0 + + # Pad the payload with a terminating 00: in case we get an odd + # number of bytes. + echo "${payload%:}:00:" | + sed 's/CHECKSUM/00:00/g' | + tr '[:lower:]' '[:upper:]' | + # Add the word to the checksum. + sed 's/\(..\):\(..\):/\1\2+\n/g' | + # Strip the extra odd byte we pushed if left unconverted. + sed 's/\(..\):$//' + + echo "10000 ~ +" # Calculate and add carry. + echo "FFFF r - p" # Bit-flip and print. + ) | + dc | + tr '[:upper:]' '[:lower:]' +} + +payload_template_expand_checksum() +{ + local payload=$1; shift + local checksum=$1; shift + + local ckbytes=$(u16_to_bytes $checksum) + + echo "$payload" | sed "s/CHECKSUM/$ckbytes/g" +} + +payload_template_nbytes() +{ + local payload=$1; shift + + payload_template_expand_checksum "${payload%:}" 0 | + sed 's/:/\n/g' | wc -l +} + igmpv3_is_in_get() { local igmpv3 -- 2.39.0
WARNING: multiple messages have this Message-ID (diff)
From: Petr Machata <petrm@nvidia.com> To: "David S. Miller" <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>, Roopa Prabhu <roopa@nvidia.com>, Nikolay Aleksandrov <razor@blackwall.org>, netdev@vger.kernel.org Cc: Petr Machata <petrm@nvidia.com>, Ido Schimmel <idosch@nvidia.com>, bridge@lists.linux-foundation.org Subject: [Bridge] [PATCH net-next v3 12/16] selftests: forwarding: lib: Add helpers for checksum handling Date: Thu, 2 Feb 2023 18:59:30 +0100 [thread overview] Message-ID: <3a152b0cf376dc1defd99d7aa78da1b409e31f4d.1675359453.git.petrm@nvidia.com> (raw) In-Reply-To: <cover.1675359453.git.petrm@nvidia.com> In order to generate IGMPv3 and MLDv2 packets on the fly, we will need helpers to calculate the packet checksum. The approach presented in this patch revolves around payload templates for mausezahn. These are mausezahn-like payload strings (01:23:45:...) with possibly one 2-byte sequence replaced with the word PAYLOAD. The main function is payload_template_calc_checksum(), which calculates RFC 1071 checksum of the message. There are further helpers to then convert the checksum to the payload format, and to expand it. For IPv6, MLDv2 message checksum is computed using a pseudoheader that differs from the header used in the payload itself. The fact that the two messages are different means that the checksum needs to be returned as a separate quantity, instead of being expanded in-place in the payload itself. Furthermore, the pseudoheader includes a length of the message. Much like the checksum, this needs to be expanded in mausezahn format. And likewise for number of addresses for (S,G) entries. Thus we have several places where a computed quantity needs to be presented in the payload format. Add a helper u16_to_bytes(), which will be used in all these cases. Signed-off-by: Petr Machata <petrm@nvidia.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> --- Notes: v2: - In the comment at payload_template_calc_checksum(), s/%#02x/%02x/, that's the mausezahn payload format. tools/testing/selftests/net/forwarding/lib.sh | 56 +++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/tools/testing/selftests/net/forwarding/lib.sh b/tools/testing/selftests/net/forwarding/lib.sh index 409ff3799b55..b10c903d9abd 100755 --- a/tools/testing/selftests/net/forwarding/lib.sh +++ b/tools/testing/selftests/net/forwarding/lib.sh @@ -1730,6 +1730,62 @@ ipv6_to_bytes() expand_ipv6 "$IP" : } +u16_to_bytes() +{ + local u16=$1; shift + + printf "%04x" $u16 | sed 's/^/000/;s/^.*\(..\)\(..\)$/\1:\2/' +} + +# Given a mausezahn-formatted payload (colon-separated bytes given as %02x), +# possibly with a keyword CHECKSUM stashed where a 16-bit checksum should be, +# calculate checksum as per RFC 1071, assuming the CHECKSUM field (if any) +# stands for 00:00. +payload_template_calc_checksum() +{ + local payload=$1; shift + + ( + # Set input radix. + echo "16i" + # Push zero for the initial checksum. + echo 0 + + # Pad the payload with a terminating 00: in case we get an odd + # number of bytes. + echo "${payload%:}:00:" | + sed 's/CHECKSUM/00:00/g' | + tr '[:lower:]' '[:upper:]' | + # Add the word to the checksum. + sed 's/\(..\):\(..\):/\1\2+\n/g' | + # Strip the extra odd byte we pushed if left unconverted. + sed 's/\(..\):$//' + + echo "10000 ~ +" # Calculate and add carry. + echo "FFFF r - p" # Bit-flip and print. + ) | + dc | + tr '[:upper:]' '[:lower:]' +} + +payload_template_expand_checksum() +{ + local payload=$1; shift + local checksum=$1; shift + + local ckbytes=$(u16_to_bytes $checksum) + + echo "$payload" | sed "s/CHECKSUM/$ckbytes/g" +} + +payload_template_nbytes() +{ + local payload=$1; shift + + payload_template_expand_checksum "${payload%:}" 0 | + sed 's/:/\n/g' | wc -l +} + igmpv3_is_in_get() { local igmpv3 -- 2.39.0
next prev parent reply other threads:[~2023-02-02 18:01 UTC|newest] Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-02-02 17:59 [PATCH net-next v3 00/16] bridge: Limit number of MDB entries per port, port-vlan Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-02 17:59 ` [PATCH net-next v3 01/16] net: bridge: Set strict_start_type at two policies Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-02 17:59 ` [PATCH net-next v3 02/16] net: bridge: Add extack to br_multicast_new_port_group() Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-02 17:59 ` [PATCH net-next v3 03/16] net: bridge: Move extack-setting " Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-02 17:59 ` [PATCH net-next v3 04/16] net: bridge: Add br_multicast_del_port_group() Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-02 17:59 ` [PATCH net-next v3 05/16] net: bridge: Change a cleanup in br_multicast_new_port_group() to goto Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-02 17:59 ` [PATCH net-next v3 06/16] net: bridge: Add a tracepoint for MDB overflows Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-03 8:58 ` Nikolay Aleksandrov 2023-02-03 8:58 ` [Bridge] " Nikolay Aleksandrov 2023-02-02 17:59 ` [PATCH net-next v3 07/16] net: bridge: Maintain number of MDB entries in net_bridge_mcast_port Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-03 8:59 ` Nikolay Aleksandrov 2023-02-03 8:59 ` [Bridge] " Nikolay Aleksandrov 2023-02-03 14:36 ` Ido Schimmel 2023-02-03 14:36 ` [Bridge] " Ido Schimmel 2023-02-02 17:59 ` [PATCH net-next v3 08/16] net: bridge: Add netlink knobs for number / maximum MDB entries Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-03 9:02 ` Nikolay Aleksandrov 2023-02-03 9:02 ` [Bridge] " Nikolay Aleksandrov 2023-02-03 14:39 ` Ido Schimmel 2023-02-03 14:39 ` [Bridge] " Ido Schimmel 2023-02-02 17:59 ` [PATCH net-next v3 09/16] selftests: forwarding: Move IGMP- and MLD-related functions to lib Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-02 17:59 ` [PATCH net-next v3 10/16] selftests: forwarding: bridge_mdb: Fix a typo Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-02 17:59 ` [PATCH net-next v3 11/16] selftests: forwarding: lib: Add helpers for IP address handling Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-02 17:59 ` Petr Machata [this message] 2023-02-02 17:59 ` [Bridge] [PATCH net-next v3 12/16] selftests: forwarding: lib: Add helpers for checksum handling Petr Machata 2023-02-02 17:59 ` [PATCH net-next v3 13/16] selftests: forwarding: lib: Parameterize IGMPv3/MLDv2 generation Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-02 17:59 ` [PATCH net-next v3 14/16] selftests: forwarding: lib: Allow list of IPs for IGMPv3/MLDv2 Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-02 17:59 ` [PATCH net-next v3 15/16] selftests: forwarding: lib: Add helpers to build IGMP/MLD leave packets Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-02 17:59 ` [PATCH net-next v3 16/16] selftests: forwarding: bridge_mdb_max: Add a new selftest Petr Machata 2023-02-02 17:59 ` [Bridge] " Petr Machata 2023-02-03 9:02 ` Nikolay Aleksandrov 2023-02-03 9:02 ` [Bridge] " Nikolay Aleksandrov 2023-02-06 9:00 ` [PATCH net-next v3 00/16] bridge: Limit number of MDB entries per port, port-vlan patchwork-bot+netdevbpf 2023-02-06 9:00 ` [Bridge] " patchwork-bot+netdevbpf
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