On 7/25/24 3:47 PM, Kui-Feng Lee wrote:
+/* Start to monitor the network traffic in the given network namespace.
+ *
+ * netns: the name of the network namespace to monitor. If NULL, the
+ * current network namespace is monitored.
+ *
+ * This function will start a thread to capture packets going through NICs
+ * in the give network namespace.
+ */
+struct tmonitor_ctx *traffic_monitor_start(const char *netns)
There is opportunity to make the traffic monitoring easier for tests that
create its own netns which I hope most of the networking tests fall into this
bucket now. Especially for tests that create multiple netns such that the test
does not have to start/stop for each individual netns.
May be adding an API like "struct nstoken *netns_new(const char *netns_name)".
The netns_new() will create the netns and (optionally) start the monitoring
thread also. It will need another "void netns_free(struct nstoken *nstoken)"
to stop the thread and remove the netns. The "struct tmonitor_ctx" probably
makes sense to be embedded into "struct nstoken" if we go with this new API.
Agree! But, I think we need another type rather than to reuse "struct
netns". People may accidentally call close_netns() on the nstoken
returned by this function.
ah. Good point. close_netns() does free the nstoken also...
yep. probably make sense to have another type for netns create/destroy which
start/stop the monitoring automatically based on the on/off in the libpcap.list.
This will need some changes to the tests creating netns but it probably should
be obvious change considering most test do "ip netns add..." and then
open_netns(). It can start with the flaky test at hand first like tc_redirect.
May be a little more changes for the test using "unshare(CLONE_NEWNET)" but
should not be too bad either. This can be done only when we need to turn on
libpcap to debug that test.
Also, when the test is flaky, make it easier for people not familiar with the
codes of the networking test to turn on traffic monitoring without changing
the test code. May be in a libpcap.list file (in parallel to the existing
DENYLIST)?
For the tests without having its own netns, they can either move to netns
(which I think it is a good thing to do) or use the
traffic_monitor_start/stop() manually by changing the testing code,
or a better way is to ask test_progs do it for the host netns (init_netns)
automatically for all tests in the libpcap.list.
Agree! I will start move some tests to netns, and use libpcap.list to
enable them.
The tc_redirect test should be in netns already. It seems the select_reuseport
and the sockmap_listen test, that this patchset is touching, are not in netns. I
hope the netns migration changes should be obvious for them. Other than those
two flaky tests, I would separate other netns moving work to another effort.
