selftests/net: packetdrill: import tcp/zerocopy

Same as initial tests, import verbatim from
github.com/google/packetdrill, aside from:

- update `source ./defaults.sh` path to adjust for flat dir
- add SPDX headers
- remove author statements if any
- drop blank lines at EOF (new)

Also import set_sysctls.py, which many scripts depend on to set
sysctls and then restore them later. This is no longer strictly needed
for namespacified sysctl. But not all sysctls are namespacified, and
doesn't hurt if they are.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20240912005317.1253001-3-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 61 insertions, 0 deletions

diff --git a/tools/testing/selftests/net/packetdrill/tcp_zerocopy_epoll_edge.pkt b/tools/testing/selftests/net/packetdrill/tcp_zerocopy_epoll_edge.pkt
new file mode 100644
index 000000000000..7671c20e01cf
--- /dev/null
+++ b/tools/testing/selftests/net/packetdrill/tcp_zerocopy_epoll_edge.pkt
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0
+// epoll zerocopy test:
+//
+// EPOLLERR is known to be not edge-triggered unlike EPOLLIN and EPOLLOUT but
+// it is not level-triggered either.
+//
+// fire two sends with MSG_ZEROCOPY and receive the acks. confirm that EPOLLERR
+// is correctly fired only once, when EPOLLET is set. send another packet with
+// MSG_ZEROCOPY. confirm that EPOLLERR is correctly fired again only once.
+`./defaults.sh`
+
+    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+   +0 setsockopt(3, SOL_SOCKET, SO_ZEROCOPY, [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 7>
+   +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
+
+   +0 fcntl(4, F_SETFL, O_RDWR|O_NONBLOCK) = 0
+   +0 epoll_create(1) = 5
+   +0 epoll_ctl(5, EPOLL_CTL_ADD, 4, {events=EPOLLOUT|EPOLLET, fd=4}) = 0
+   +0 epoll_wait(5, {events=EPOLLOUT, fd=4}, 1, 0) = 1
+
+   +0 send(4, ..., 4000, MSG_ZEROCOPY) = 4000
+   +0 > P. 1:4001(4000) ack 1
+   +0 < . 1:1(0) ack 4001 win 257
+
+   +0 send(4, ..., 4000, MSG_ZEROCOPY) = 4000
+   +0 > P. 4001:8001(4000) ack 1
+   +0 < . 1:1(0) ack 8001 win 257
+
+// receive only one EPOLLERR for the two sends above.
+   +0 epoll_wait(5, {events=EPOLLERR|EPOLLOUT, fd=4}, 1, 0) = 1
+   +0 epoll_wait(5, {events=0, ptr=0}, 1, 0) = 0
+
+   +0 send(4, ..., 4000, MSG_ZEROCOPY) = 4000
+   +0 > P. 8001:12001(4000) ack 1
+   +0 < . 1:1(0) ack 12001 win 257
+
+// receive only one EPOLLERR for the third send above.
+   +0 epoll_wait(5, {events=EPOLLERR|EPOLLOUT, fd=4}, 1, 0) = 1
+   +0 epoll_wait(5, {events=0, ptr=0}, 1, 0) = 0
+
+   +0 recvmsg(4, {msg_name(...)=...,
+                  msg_iov(1)=[{...,0}],
+                  msg_flags=MSG_ERRQUEUE,
+                  msg_control=[
+                        {cmsg_level=CMSG_LEVEL_IP,
+                         cmsg_type=CMSG_TYPE_RECVERR,
+                         cmsg_data={ee_errno=0,
+                                    ee_origin=SO_EE_ORIGIN_ZEROCOPY,
+                                    ee_type=0,
+                                    ee_code=SO_EE_CODE_ZEROCOPY_COPIED,
+                                    ee_info=0,
+                                    ee_data=2}}
+                   ]}, MSG_ERRQUEUE) = 0