tcptracer-bpf.c: remove dead entries from the tuplepid_ipv{4,6} #23

iaguis · 2017-02-23T14:54:31Z

This patch avoids that tuplepid_ipv{4,6} fill up with dead entries
because a connection was refused.

Fixes #21

Depends on #25

alban · 2017-02-23T20:23:33Z

I tested this branch with half-duplex connections because the tcp connections goes to different states in the kernel in those cases (calling tcp_set_state differently).

Calling shutdown(..., SHUT_WR) server-side:

echo foo | busybox nc -l -p 1234
busybox nc 127.0.0.1 1234

Calling shutdown(..., SHUT_WR) client-side:

busybox nc -l -p 1234
echo bar | busybox nc 127.0.0.1 1234

Note: I am using the busybox netcat. The GNU netcat or BSD netcat have a different implementation, they might not use shutdown(2) in the same way. It's best to check with "strace" that shutdown(2) is called according to the test scenario.

And it worked fine for me.

tcptracer-bpf.c

@@ -538,6 +538,9 @@ int kprobe__tcp_set_state(struct pt_regs *ctx)
 		if (!read_ipv4_tuple(&t, status, skp)) {
 			return 0;
 		}
+		if (state == TCP_CLOSE) {
+			bpf_map_delete_elem(&tuplepid_ipv4, &t);


This patch avoids that `tuplepid_ipv{4,6}` fill up with dead entries because a connection was refused. Fixes weaveworks#21

This test makes sure that `tuplepid_ipv{4,6}` do not fill up with dead connections.

schu

LGTM

…racer Remove network-tracer agent as it's been merged into another repo

iaguis force-pushed the iaguis/fix-set-state branch 3 times, most recently from 998563b to 7ca3e09 Compare February 23, 2017 15:26

alban reviewed Feb 23, 2017

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alban mentioned this pull request Feb 23, 2017

Add tests covering possible transitions #20

Open

iaguis force-pushed the iaguis/fix-set-state branch 2 times, most recently from a2673fb to 5078a60 Compare February 27, 2017 11:04

iaguis changed the title ~~tcptracer-bpf.c: remove dead entries form the tuplepid_ipv{4,6}~~ tcptracer-bpf.c: remove dead entries from the tuplepid_ipv{4,6} Feb 28, 2017

iaguis force-pushed the iaguis/fix-set-state branch 7 times, most recently from 7832fa1 to 0f7607a Compare March 1, 2017 11:12

Alessandro Puccetti and others added 3 commits March 8, 2017 11:42

tcptracer-bpf.c: remove dead entries from the tuplepid_ipv{4,6}

871abac

This patch avoids that `tuplepid_ipv{4,6}` fill up with dead entries because a connection was refused. Fixes weaveworks#21

tests: add multiple connections refused test

6993240

This test makes sure that `tuplepid_ipv{4,6}` do not fill up with dead connections.

Ignore .git/* when linting

a3e68dd

iaguis force-pushed the iaguis/fix-set-state branch from 0f7607a to a3e68dd Compare March 8, 2017 10:43

schu approved these changes Mar 8, 2017

View reviewed changes

iaguis force-pushed the iaguis/fix-set-state branch from 513e367 to a3e68dd Compare March 8, 2017 11:25

iaguis merged commit 2a95dd0 into weaveworks:master Mar 8, 2017

schu deleted the iaguis/fix-set-state branch March 28, 2017 07:28

sunhay added a commit to DataDog/tcptracer-bpf that referenced this pull request Feb 21, 2019

Merge pull request weaveworks#23 from DataDog/sunhay/delete-network-t…

43c8726

…racer Remove network-tracer agent as it's been merged into another repo

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tcptracer-bpf.c: remove dead entries from the tuplepid_ipv{4,6} #23

tcptracer-bpf.c: remove dead entries from the tuplepid_ipv{4,6} #23

iaguis commented Feb 23, 2017 •

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tcptracer-bpf.c: remove dead entries from the tuplepid_ipv{4,6} #23

tcptracer-bpf.c: remove dead entries from the tuplepid_ipv{4,6} #23

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iaguis commented Feb 23, 2017 •

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alban commented Feb 23, 2017 •

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