selftests/net: packetdrill: import tcp/user_timeout, tcp/validate, tcp/sendfile, tcp/limited-transmit, tcp/syscall_bad_arg

Use the standard import and testing method, as described in the
import of tcp/ecn and tcp/close , tcp/sack , tcp/tcp_info.

Signed-off-by: Willem de Bruijn <[e-mail]>
Signed-off-by: Soham Chakradeo <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

tools/testing/selftests/net/packetdrill/tcp_limited_transmit_limited-transmit-no-sack.pkt

···
+// SPDX-License-Identifier: GPL-2.0
+// Test RFC 3042 "Limited Transmit": "sending a new data segment in
+// response to each of the first two duplicate acknowledgments that
+// arrive at the sender".
+// This variation tests a receiver that doesn't support SACK.
+
+`./defaults.sh`
+
+// Establish a connection.
+    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
+
+  +.1 < S 0:0(0) win 32792 <mss 1000,nop,wscale 7>
+   +0 > S. 0:0(0) ack 1 <mss 1460,nop,wscale 8>
+  +.1 < . 1:1(0) ack 1 win 320
+   +0 accept(3, ..., ...) = 4
+
+// Write some data, and send the initial congestion window.
+   +0 write(4, ..., 15000) = 15000
+   +0 > P. 1:10001(10000) ack 1
+
+// Limited transmit: on first dupack, send a new data segment.
+ +.11 < . 1:1(0) ack 1 win 320
+   +0 > . 10001:11001(1000) ack 1
+
+// Limited transmit: on second dupack, send a new data segment.
+ +.01 < . 1:1(0) ack 1 win 320
+   +0 > . 11001:12001(1000) ack 1
+
+// It turned out to be reordering, not loss.
+// We have one packet newly acked (1001:3001 were DUP-ACK'd)
+// So we revert state back to Open. Slow start cwnd from 10 to 11
+// and send 11 - 9 = 2 packets
+ +.01 < . 1:1(0) ack 3001 win 320
+   +0 > P. 12001:14001(2000) ack 1
+
+ +.02 < . 1:1(0) ack 5001 win 320
+   +0 > P. 14001:15001(1000) ack 1
+
+// Client gradually ACKs all data.
+ +.02 < . 1:1(0) ack 7001 win 320
+ +.02 < . 1:1(0) ack 9001 win 320
+ +.02 < . 1:1(0) ack 11001 win 320
+ +.02 < . 1:1(0) ack 13001 win 320
+ +.02 < . 1:1(0) ack 15001 win 320
+
+// Clean up.
+ +.17 close(4) = 0
+   +0 > F. 15001:15001(0) ack 1
+  +.1 < F. 1:1(0) ack 15002 win 257
+   +0 > . 15002:15002(0) ack 2

tools/testing/selftests/net/packetdrill/tcp_limited_transmit_limited-transmit-sack.pkt

···
+// SPDX-License-Identifier: GPL-2.0
+// Test RFC 3042 "Limited Transmit": "sending a new data segment in
+// response to each of the first two duplicate acknowledgments that
+// arrive at the sender".
+// This variation tests a receiver that supports SACK.
+
+`./defaults.sh`
+
+// Establish a connection.
+    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
+
+  +.1 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>
+   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
+  +.1 < . 1:1(0) ack 1 win 320
+   +0 accept(3, ..., ...) = 4
+
+// Write some data, and send the initial congestion window.
+   +0 write(4, ..., 15000) = 15000
+   +0 > P. 1:10001(10000) ack 1
+
+// Limited transmit: on first dupack, send a new data segment.
+ +.11 < . 1:1(0) ack 1 win 320 <sack 1001:2001,nop,nop>
+   +0 > . 10001:11001(1000) ack 1
+
+// Limited transmit: on second dupack, send a new data segment.
+ +.01 < . 1:1(0) ack 1 win 320 <sack 1001:3001,nop,nop>
+   +0 > . 11001:12001(1000) ack 1
+
+// It turned out to be reordering, not loss.
+ +.01 < . 1:1(0) ack 3001 win 320
+   +0 > P. 12001:14001(2000) ack 1
+
+ +.02 < . 1:1(0) ack 5001 win 320
+   +0 > P. 14001:15001(1000) ack 1
+
+// Client gradually ACKs all data.
+ +.02 < . 1:1(0) ack 7001 win 320
+ +.02 < . 1:1(0) ack 9001 win 320
+ +.02 < . 1:1(0) ack 11001 win 320
+ +.02 < . 1:1(0) ack 13001 win 320
+ +.02 < . 1:1(0) ack 15001 win 320
+
+// Clean up.
+ +.17 close(4) = 0
+   +0 > F. 15001:15001(0) ack 1
+  +.1 < F. 1:1(0) ack 15002 win 257
+   +0 > . 15002:15002(0) ack 2

tools/testing/selftests/net/packetdrill/tcp_sendfile_sendfile-simple.pkt

···
+// SPDX-License-Identifier: GPL-2.0
+// Simplest possible test of open() and then sendfile().
+// We write some zeroes into a file (since packetdrill expects payloads
+// to be all zeroes) and then open() the file, then use sendfile()
+// and verify that the correct number of zeroes goes out.
+
+`./defaults.sh
+/bin/rm -f /tmp/testfile
+/bin/dd bs=1 count=5 if=/dev/zero of=/tmp/testfile status=none
+`
+
+// Initialize connection
+    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 32792 <mss 1000,sackOK,nop,nop,nop,wscale 10>
+   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
+   +0 < . 1:1(0) ack 1 win 514
+
+   +0 accept(3, ..., ...) = 4
+
+   +0 open("/tmp/testfile", O_RDONLY) = 5
+   +0 sendfile(4, 5, [0], 5) = 5
+   +0 > P. 1:6(5) ack 1

tools/testing/selftests/net/packetdrill/tcp_syscall_bad_arg_fastopen-invalid-buf-ptr.pkt

···
+// SPDX-License-Identifier: GPL-2.0
+// Test TCP fastopen behavior with NULL as buffer pointer, but a non-zero
+// buffer length.
+`./defaults.sh
+./set_sysctls.py /proc/sys/net/ipv4/tcp_timestamps=0`
+
+// Cache warmup: send a Fast Open cookie request
+ 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
++0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0
++0 setsockopt(3, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0
++0 connect(3, ..., ...) = -1 EINPROGRESS (Operation is now in progress)
++0 > S 0:0(0) <mss 1460,nop,nop,sackOK,nop,wscale 8,FO,nop,nop>
++0 < S. 123:123(0) ack 1 win 14600 <mss 1460,nop,nop,sackOK,nop,wscale 6,FO abcd1234,nop,nop>
++0 > . 1:1(0) ack 1
++0 close(3) = 0
++0 > F. 1:1(0) ack 1
++0 < F. 1:1(0) ack 2 win 92
++0 > .  2:2(0) ack 2
+
+// Test with MSG_FASTOPEN without TCP_FASTOPEN_CONNECT.
++0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 4
++0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0
++0 sendto(4, NULL, 1, MSG_FASTOPEN, ..., ...) = -1
++0 close(4) = 0
+
+// Test with TCP_FASTOPEN_CONNECT without MSG_FASTOPEN.
++0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 5
++0 fcntl(5, F_SETFL, O_RDWR|O_NONBLOCK) = 0
++0 setsockopt(5, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0
++0 connect(5, ..., ...) = 0
++0 sendto(5, NULL, 1, 0, ..., ...) = -1
++0 close(5) = 0
+
+// Test with both TCP_FASTOPEN_CONNECT and MSG_FASTOPEN.
++0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 6
++0 fcntl(6, F_SETFL, O_RDWR|O_NONBLOCK) = 0
++0 setsockopt(6, SOL_TCP, TCP_FASTOPEN_CONNECT, [1], 4) = 0
++0 connect(6, ..., ...) = 0
++0 sendto(6, NULL, 1, MSG_FASTOPEN, ..., ...) = -1
++0 close(6) = 0
+
+`/tmp/sysctl_restore_${PPID}.sh`

tools/testing/selftests/net/packetdrill/tcp_syscall_bad_arg_sendmsg-empty-iov.pkt

···
+// SPDX-License-Identifier: GPL-2.0
+// Test that we correctly skip zero-length IOVs.
+`./defaults.sh`
+    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+   +0 setsockopt(3, SOL_SOCKET, SO_ZEROCOPY, [1], 4) = 0
+   +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 32792 <mss 1000,nop,wscale 7>
+   +0 > S. 0:0(0) ack 1 <mss 1460,nop,wscale 8>
+ +.01 < . 1:1(0) ack 1 win 257
+   +0 accept(3, ..., ...) = 4
+   +0 setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = 0
+
+   +0 sendmsg(4, {msg_name(...)=...,
+                  msg_iov(4)=[{..., 0}, {..., 40}, {..., 0}, {..., 20}],
+                  msg_flags=0}, 0) = 60
+   +0 > P. 1:61(60) ack 1
+ +.01 < . 1:1(0) ack 61 win 257
+
+   +0 sendmsg(4, {msg_name(...)=...,
+                  msg_iov(4)=[{..., 0}, {..., 0}, {..., 0}, {..., 0}],
+                  msg_flags=0}, MSG_ZEROCOPY) = 0
+
+   +0 sendmsg(4, {msg_name(...)=...,
+                  msg_iov(4)=[{..., 0}, {..., 10}, {..., 0}, {..., 50}],
+                  msg_flags=0}, MSG_ZEROCOPY) = 60
+   +0 > P. 61:121(60) ack 1
+ +.01 < . 1:1(0) ack 121 win 257

tools/testing/selftests/net/packetdrill/tcp_syscall_bad_arg_syscall-invalid-buf-ptr.pkt

···
+// SPDX-License-Identifier: GPL-2.0
+// Test kernel behavior with NULL as buffer pointer
+
+`./defaults.sh`
+
+    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+   +0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0
+   +0 bind(3, ..., ...) = 0
+   +0 listen(3, 1) = 0
+
+   +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 10>
+   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
+  +.2 < . 1:1(0) ack 1 win 514
+
+   +0 accept(3, ..., ...) = 4
+
+   +0 write(4, NULL, 1000) = -1 EFAULT (Bad address)
+   +0 send(4, NULL, 1000, 0) = -1 EFAULT (Bad address)
+   +0 sendto(4, NULL, 1000, 0, ..., ...) = -1 EFAULT (Bad address)
+
+   +0 < . 1:1001(1000) ack 1 win 200
+   +0 read(4, NULL, 1000) = -1 EFAULT (Bad address)
+   +0 recv(4, NULL, 1000, 0) = -1 EFAULT (Bad address)
+   +0 recvfrom(4, NULL, 1000, 0, ..., ...) = -1 EFAULT (Bad address)

tools/testing/selftests/net/packetdrill/tcp_user_timeout_user-timeout-probe.pkt

···
+// SPDX-License-Identifier: GPL-2.0
+
+`./defaults.sh`
+
+    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 0 <mss 1460>
+   +0 > S. 0:0(0) ack 1 <mss 1460>
+
+  +.1 < . 1:1(0) ack 1 win 65530
+   +0 accept(3, ..., ...) = 4
+
+   +0 setsockopt(4, SOL_TCP, TCP_USER_TIMEOUT, [3000], 4) = 0
+   +0 write(4, ..., 24) = 24
+   +0 > P. 1:25(24) ack 1
+   +.1 < . 1:1(0) ack 25 win 65530
+   +0 %{ assert tcpi_probes == 0, tcpi_probes; \
+         assert tcpi_backoff == 0, tcpi_backoff }%
+
+// install a qdisc dropping all packets
+   +0 `tc qdisc delete dev tun0 root 2>/dev/null ; tc qdisc add dev tun0 root pfifo limit 0`
+   +0 write(4, ..., 24) = 24
+   // When qdisc is congested we retry every 500ms
+   // (TCP_RESOURCE_PROBE_INTERVAL) and therefore
+   // we retry 6 times before hitting 3s timeout.
+   // First verify that the connection is alive:
++3.250 write(4, ..., 24) = 24
+   // Now verify that shortly after that the socket is dead:
+ +.100 write(4, ..., 24) = -1 ETIMEDOUT (Connection timed out)
+
+   +0 %{ assert tcpi_probes == 6, tcpi_probes; \
+         assert tcpi_backoff == 0, tcpi_backoff }%
+   +0 close(4) = 0

tools/testing/selftests/net/packetdrill/tcp_user_timeout_user_timeout.pkt

···
+// SPDX-License-Identifier: GPL-2.0
+`./defaults.sh`
+
+// Initialize connection
+    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 32792 <mss 1000,sackOK,nop,nop>
+   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK>
+  +.1 < . 1:1(0) ack 1 win 32792
+
+
+   +0 accept(3, ..., ...) = 4
+
+// Okay, we received nothing, and decide to close this idle socket.
+// We set TCP_USER_TIMEOUT to 3 seconds because really it is not worth
+// trying hard to cleanly close this flow, at the price of keeping
+// a TCP structure in kernel for about 1 minute !
+   +2 setsockopt(4, SOL_TCP, TCP_USER_TIMEOUT, [3000], 4) = 0
+   +0 close(4) = 0
+
+   +0 > F. 1:1(0) ack 1
+  +.3~+.400 > F. 1:1(0) ack 1
+  +.3~+.400 > F. 1:1(0) ack 1
+  +.6~+.800 > F. 1:1(0) ack 1
+
+// We finally receive something from the peer, but it is way too late
+// Our socket vanished because TCP_USER_TIMEOUT was really small
+   +0 < . 1:2(1) ack 1 win 32792
+   +0 > R 1:1(0)

tools/testing/selftests/net/packetdrill/tcp_validate_validate-established-no-flags.pkt

···
+// SPDX-License-Identifier: GPL-2.0
+// Verify that established connections drop a segment without the ACK flag set.
+
+`./defaults.sh`
+
+// Create a socket.
+    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
+
+// Establish a connection.
+   +0 < S 0:0(0) win 20000 <mss 1000,sackOK,nop,nop>
+   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK>
+ +.01 < . 1:1(0) ack 1 win 20000
+   +0 accept(3, ..., ...) = 4
+
+// Receive a segment with no flags set, verify that it's not enqueued.
+ +.01 < - 1:1001(1000) win 20000
+   +0 ioctl(4, SIOCINQ, [0]) = 0
+
+// Receive a segment with ACK flag set, verify that it is enqueued.
+ +.01 < . 1:1001(1000) ack 1 win 20000
+   +0 ioctl(4, SIOCINQ, [1000]) = 0