[PATCH net 1/2] Revert "selftests: net: packetdrill: add tests for advertised MSS with PMTU exceptions"

[Esko Mobius via B4 Relay]

From: Esko Mobius <echoowall@xxxxxxxxx>

This reverts commit e5c8e301b497 ("selftests: net: packetdrill: add
tests for advertised MSS with PMTU exceptions").

These tests assert the behaviour introduced by commit 2640e6419594
("net: advertise TCP MSS from the configured MTU, not the learned
PMTU"), which is reverted in the next patch because it causes a
regression. Remove them first so the series stays bisectable.

Signed-off-by: Esko Mobius <echoowall@xxxxxxxxx>
---
 .../net/packetdrill/tcp_advmss_pmtu_ipv4.pkt       | 67 ----------------------
 .../net/packetdrill/tcp_advmss_pmtu_ipv6.pkt       | 67 ----------------------
 2 files changed, 134 deletions(-)

diff --git a/tools/testing/selftests/net/packetdrill/tcp_advmss_pmtu_ipv4.pkt b/tools/testing/selftests/net/packetdrill/tcp_advmss_pmtu_ipv4.pkt
deleted file mode 100644
index f2ef931b7..000000000
--- a/tools/testing/selftests/net/packetdrill/tcp_advmss_pmtu_ipv4.pkt
+++ /dev/null
@@ -1,67 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-//
-// Test that IPv4 advertised MSS in SYN-ACK is derived from the configured
-// interface MTU (1500 -> MSS 1460), not the ICMP-learned Path MTU.
-
---ip_version=ipv4
-
-`./defaults.sh
-ethtool -K tun0 tso off
-`
-
-//
-// Connection 1: Learn PMTU exception (MTU 1200 -> MSS 1160)
-//
-    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
-   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
-   +0 bind(3, ..., ...) = 0
-   +0 listen(3, 1) = 0
-
-   +0 < S 0:0(0) win 65535 <mss 1460,sackOK,nop,nop,nop,wscale 8>
-   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
-  +.1 < . 1:1(0) ack 1 win 257
-   +0 accept(3, ..., ...) = 4
-
-// Send a full 1460-byte segment
-   +0 write(4, ..., 1460) = 1460
-   +0 > P. 1:1461(1460) ack 1
-
-// ICMP Fragmentation Needed arrives indicating next-hop MTU 1200
-   +0 < icmp unreachable frag_needed mtu 1200 [1:1461(1460)]
-
-// Local host retransmits using the learned MTU 1200 (MSS = 1200 - 40 = 1160)
-   +0 > . 1:1161(1160) ack 1
-   +0 > P. 1161:1461(300) ack 1
-   +0 < R 1:1(0) ack 1461 win 0
-
-// Close connection 1 and listener
-   +0 close(4) = 0
-   +0 close(3) = 0
-
-//
-// Connection 2: New connection from the same peer
-//
-   +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
-   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
-   +0 bind(3, ..., ...) = 0
-   +0 listen(3, 1) = 0
-
-   +0 < S 0:0(0) win 65535 <mss 1460,sackOK,nop,nop,nop,wscale 8>
-
-// Verify: SYN-ACK MUST advertise configured MSS 1460, NOT the learned PMTU MSS 1160
-   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
-   +0 < . 1:1(0) ack 1 win 257
-   +0 accept(3, ..., ...) = 4
-
-// Verify: Outgoing transmit MSS is still constrained by the learned PMTU 1200
-   +0 write(4, ..., 1460) = 1460
-   +0 > . 1:1161(1160) ack 1
-   +0 > P. 1161:1461(300) ack 1
-   +0 < . 1:1(0) ack 1461 win 257
-
-// Clean up
-   +0 close(4) = 0
-   +0 > F. 1461:1461(0) ack 1
-   +0 < F. 1:1(0) ack 1462 win 257
-   +0 > . 1462:1462(0) ack 2
-   +0 close(3) = 0
diff --git a/tools/testing/selftests/net/packetdrill/tcp_advmss_pmtu_ipv6.pkt b/tools/testing/selftests/net/packetdrill/tcp_advmss_pmtu_ipv6.pkt
deleted file mode 100644
index c7638b11a..000000000
--- a/tools/testing/selftests/net/packetdrill/tcp_advmss_pmtu_ipv6.pkt
+++ /dev/null
@@ -1,67 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-//
-// Test that IPv6 advertised MSS in SYN-ACK is derived from the configured
-// interface MTU (1520 -> MSS 1460), not the ICMPv6-learned Path MTU.
-
---ip_version=ipv6
-
-`./defaults.sh
-ethtool -K tun0 tso off
-`
-
-//
-// Connection 1: Learn PMTU exception (MTU 1280 -> MSS 1220)
-//
-    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
-   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
-   +0 bind(3, ..., ...) = 0
-   +0 listen(3, 1) = 0
-
-   +0 < S 0:0(0) win 65535 <mss 1460,sackOK,nop,nop,nop,wscale 8>
-   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
-  +.1 < . 1:1(0) ack 1 win 257
-   +0 accept(3, ..., ...) = 4
-
-// Send a full 1460-byte segment
-   +0 write(4, ..., 1460) = 1460
-   +0 > P. 1:1461(1460) ack 1
-
-// ICMPv6 Packet Too Big arrives indicating next-hop MTU 1280
-   +0 < icmp packet_too_big mtu 1280 [1:1461(1460)]
-
-// Local host retransmits using the learned MTU 1280 (MSS = 1280 - 40 - 20 = 1220)
-   +0 > . 1:1221(1220) ack 1
-   +0 > P. 1221:1461(240) ack 1
-   +0 < R 1:1(0) ack 1461 win 0
-
-// Close connection 1 and listener
-   +0 close(4) = 0
-   +0 close(3) = 0
-
-//
-// Connection 2: New connection from the same peer
-//
-   +0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
-   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
-   +0 bind(3, ..., ...) = 0
-   +0 listen(3, 1) = 0
-
-   +0 < S 0:0(0) win 65535 <mss 1460,sackOK,nop,nop,nop,wscale 8>
-
-// Verify: SYN-ACK MUST advertise configured MSS 1460, NOT the learned PMTU MSS 1220
-   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
-   +0 < . 1:1(0) ack 1 win 257
-   +0 accept(3, ..., ...) = 4
-
-// Verify: Outgoing transmit MSS is still constrained by the learned PMTU 1280
-   +0 write(4, ..., 1460) = 1460
-   +0 > . 1:1221(1220) ack 1
-   +0 > P. 1221:1461(240) ack 1
-   +0 < . 1:1(0) ack 1461 win 257
-
-// Clean up
-   +0 close(4) = 0
-   +0 > F. 1461:1461(0) ack 1
-   +0 < F. 1:1(0) ack 1462 win 257
-   +0 > . 1462:1462(0) ack 2
-   +0 close(3) = 0

-- 
Git-157)