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

Source file repositories/reference/linux-study-clean/tools/testing/selftests/net/packetdrill/tcp_timestamping_tcp_tx_timestamp_bug.pkt

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/net/packetdrill/tcp_timestamping_tcp_tx_timestamp_bug.pkt
Extension
.pkt
Size
2719 bytes
Lines
71
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: tools
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
// Test after "tcp: tcp_tx_timestamp() must look at the rtx queue"

// This test is about receiving the SCM_TSTAMP_ACK,
// we do not care about its SCM_TIMESTAMPING precision.
--tolerance_usecs=1000000

`./defaults.sh
sysctl -q net.ipv4.tcp_min_tso_segs=70
`

// Create a socket and set it to non-blocking.
    0	socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
   +0	fcntl(3, F_GETFL) = 0x2 (flags O_RDWR)
   +0	fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0

// Establish connection and verify that there was no error.
   +0	connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress)
   +0	> S 0:0(0) <mss 1460,sackOK,TS val 100 ecr 0,nop,wscale 8>
+.010	< S. 0:0(0) ack 1 win 65535 <mss 1000,sackOK,TS val 700 ecr 100,nop,wscale 7>
   +0	> . 1:1(0) ack 1 <nop,nop,TS val 200 ecr 700>
   +0	getsockopt(3, SOL_SOCKET, SO_ERROR, [0], [4]) = 0
   +0	setsockopt(3, SOL_SOCKET, SO_SNDBUF, [30000], 4) = 0

   +0   write(3, ..., 9880) = 9880
   +0   > P. 1:9881(9880) ack 1 <nop,nop,TS val 200 ecr 700>
+.010   < . 1:1(0) ack 9881 win 10000 <nop,nop,TS val 701 ecr 200>

   +0   write(3, ..., 19760) = 19760
   +0   > P. 9881:29641(19760) ack 1 <nop,nop,TS val 201 ecr 701>
+.010   < . 1:1(0) ack 29641 win 10000 <nop,nop,TS val 702 ecr 201>

   +0   write(3, ..., 39520) = 39520
   +0   > P. 29641:69161(39520) ack 1 <nop,nop,TS val 202 ecr 702>
+.010   < . 1:1(0) ack 69161 win 10000 <nop,nop,TS val 703 ecr 202>

// One more write to increase cwnd
   +0	write(3, ..., 79040) = 79040
   +0	> P. 69161:108681(39520) ack 1 <nop,nop,TS val 203 ecr 703>
   +0	> P. 108681:148201(39520) ack 1 <nop,nop,TS val 203 ecr 703>
+.010	< . 1:1(0) ack 148201 win 1000 <nop,nop,TS val 704 ecr 203>

   +0	setsockopt(3, SOL_SOCKET, SO_TIMESTAMPING,
		   [SOF_TIMESTAMPING_TX_ACK | SOF_TIMESTAMPING_SOFTWARE |
		    SOF_TIMESTAMPING_OPT_ID], 4) = 0

// We have one write filling one skb
// last byte can not be stored because of our small SO_SNDBUF
   +0	write(3, ..., 65209) = 65208
   +0	> P. 148201:213409(65208) ack 1 <nop,nop,TS val 204 ecr 704>
+.010	< . 1:1(0) ack 213409 win 1000 <nop,nop,TS val 705 ecr 204>

// SCM_TSTAMP_ACK should be received after the last ack at
// t=60ms.
   +0	recvmsg(3, {msg_name(...)=...,
		    msg_iov(1)=[{...,0}],
                    msg_flags=MSG_ERRQUEUE|MSG_TRUNC,
                    msg_control=[
			{cmsg_level=SOL_SOCKET,
			 cmsg_type=SCM_TIMESTAMPING,
			 cmsg_data={scm_sec=0,scm_nsec=60000000}},
			{cmsg_level=CMSG_LEVEL_IP,
			 cmsg_type=CMSG_TYPE_RECVERR,
			 cmsg_data={ee_errno=ENOMSG,
				    ee_origin=SO_EE_ORIGIN_TIMESTAMPING,
				    ee_type=0,
				    ee_code=0,
				    ee_info=SCM_TSTAMP_ACK,
				    ee_data=65207}}
		    ]}, MSG_ERRQUEUE) = 0

Annotation

Implementation Notes