Implement a new test program mptcpify: if the family is AF_INET or
AF_INET6, the type is SOCK_STREAM, and the protocol ID is 0 or
IPPROTO_TCP, set it to IPPROTO_MPTCP. It will be hooked in
update_socket_protocol().
Extend the MPTCP test base, add a selftest test_mptcpify() for the
mptcpify case. Open and load the mptcpify test prog to mptcpify the
TCP sockets dynamically, then use start_server() and connect_to_fd()
to create a TCP socket, but actually what's created is an MPTCP
socket, which can be verified through the outputs of 'ss' and 'nstat'
commands.
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
.../testing/selftests/bpf/prog_tests/mptcp.c | 94 +++++++++++++++++++
tools/testing/selftests/bpf/progs/mptcpify.c | 25 +++++
2 files changed, 119 insertions(+)
create mode 100644 tools/testing/selftests/bpf/progs/mptcpify.c
diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index 4407bd5c9e9a..caab3aa6a162 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -6,6 +6,7 @@
#include "cgroup_helpers.h"
#include "network_helpers.h"
#include "mptcp_sock.skel.h"
+#include "mptcpify.skel.h"
char NS_TEST[32];
@@ -195,8 +196,101 @@ static void test_base(void)
close(cgroup_fd);
}
+static void send_byte(int fd)
+{
+ char b = 0x55;
+
+ ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "send single byte");
+}
+
+static int verify_mptcpify(void)
+{
+ char cmd[256];
+ int err = 0;
+
+ snprintf(cmd, sizeof(cmd),
+ "ip netns exec %s ss -tOni | grep -q '%s'",
+ NS_TEST, "tcp-ulp-mptcp");
+ if (!ASSERT_OK(system(cmd), "No tcp-ulp-mptcp found!"))
+ err++;
+
+ snprintf(cmd, sizeof(cmd),
+ "ip netns exec %s nstat -asz %s | awk '%s' | grep -q '%s'",
+ NS_TEST, "MPTcpExtMPCapableSYNACKRX",
+ "NR==1 {next} {print $2}", "1");
+ if (!ASSERT_OK(system(cmd), "No MPTcpExtMPCapableSYNACKRX found!"))
+ err++;
+
+ return err;
+}
+
+static int run_mptcpify(int cgroup_fd)
+{
+ int server_fd, client_fd, prog_fd, err = 0;
+ struct mptcpify *mptcpify_skel;
+
+ mptcpify_skel = mptcpify__open_and_load();
+ if (!ASSERT_OK_PTR(mptcpify_skel, "skel_open_load"))
+ return -EIO;
+
+ err = mptcpify__attach(mptcpify_skel);
+ if (!ASSERT_OK(err, "skel_attach"))
+ goto out;
+
+ prog_fd = bpf_program__fd(mptcpify_skel->progs.mptcpify);
+ if (!ASSERT_GE(prog_fd, 0, "bpf_program__fd")) {
+ err = -EIO;
+ goto out;
+ }
+
+ /* without MPTCP */
+ server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
+ if (!ASSERT_GE(server_fd, 0, "start_server")) {
+ err = -EIO;
+ goto out;
+ }
+
+ client_fd = connect_to_fd(server_fd, 0);
+ if (!ASSERT_GE(client_fd, 0, "connect to fd")) {
+ err = -EIO;
+ goto close_server;
+ }
+
+ send_byte(client_fd);
+ err += verify_mptcpify();
+
+ close(client_fd);
+close_server:
+ close(server_fd);
+out:
+ mptcpify__destroy(mptcpify_skel);
+ return err;
+}
+
+static void test_mptcpify(void)
+{
+ struct nstoken *nstoken = NULL;
+ int cgroup_fd;
+
+ cgroup_fd = test__join_cgroup("/mptcpify");
+ if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
+ return;
+
+ nstoken = create_netns();
+ if (!ASSERT_OK_PTR(nstoken, "create_netns"))
+ goto fail;
+
+ ASSERT_OK(run_mptcpify(cgroup_fd), "run_mptcpify");
+
+fail:
+ cleanup_netns(nstoken);
+ close(cgroup_fd);
+}
+
void test_mptcp(void)
{
if (test__start_subtest("base"))
test_base();
+ if (test__start_subtest("mptcpify"))
+ test_mptcpify();
}
diff --git a/tools/testing/selftests/bpf/progs/mptcpify.c b/tools/testing/selftests/bpf/progs/mptcpify.c
new file mode 100644
index 000000000000..9cf1febe982d
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/mptcpify.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023, SUSE. */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+#define AF_INET 2
+#define AF_INET6 10
+#define SOCK_STREAM 1
+#define IPPROTO_TCP 6
+#define IPPROTO_MPTCP 262
+
+SEC("fmod_ret/update_socket_protocol")
+int BPF_PROG(mptcpify, int family, int type, int protocol)
+{
+ if ((family == AF_INET || family == AF_INET6) &&
+ type == SOCK_STREAM &&
+ (!protocol || protocol == IPPROTO_TCP)) {
+ return IPPROTO_MPTCP;
+ }
+
+ return protocol;
+}
--
2.35.3
On 8/3/23 6:41 AM, Geliang Tang wrote:
> Implement a new test program mptcpify: if the family is AF_INET or
> AF_INET6, the type is SOCK_STREAM, and the protocol ID is 0 or
> IPPROTO_TCP, set it to IPPROTO_MPTCP. It will be hooked in
> update_socket_protocol().
>
> Extend the MPTCP test base, add a selftest test_mptcpify() for the
> mptcpify case. Open and load the mptcpify test prog to mptcpify the
> TCP sockets dynamically, then use start_server() and connect_to_fd()
> to create a TCP socket, but actually what's created is an MPTCP
> socket, which can be verified through the outputs of 'ss' and 'nstat'
> commands.
>
> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
> Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> ---
> .../testing/selftests/bpf/prog_tests/mptcp.c | 94 +++++++++++++++++++
> tools/testing/selftests/bpf/progs/mptcpify.c | 25 +++++
> 2 files changed, 119 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/progs/mptcpify.c
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> index 4407bd5c9e9a..caab3aa6a162 100644
> --- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
> +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> @@ -6,6 +6,7 @@
> #include "cgroup_helpers.h"
> #include "network_helpers.h"
> #include "mptcp_sock.skel.h"
> +#include "mptcpify.skel.h"
>
> char NS_TEST[32];
>
> @@ -195,8 +196,101 @@ static void test_base(void)
> close(cgroup_fd);
> }
>
> +static void send_byte(int fd)
> +{
> + char b = 0x55;
> +
> + ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "send single byte");
> +}
> +
> +static int verify_mptcpify(void)
> +{
> + char cmd[256];
> + int err = 0;
> +
> + snprintf(cmd, sizeof(cmd),
> + "ip netns exec %s ss -tOni | grep -q '%s'",
> + NS_TEST, "tcp-ulp-mptcp");
Could you show what is the expected output from the above command line
ip netns exec %s ss -tOni
?
This way, users can easily reason about the ss states based on tests.
> + if (!ASSERT_OK(system(cmd), "No tcp-ulp-mptcp found!"))
> + err++;
> +
> + snprintf(cmd, sizeof(cmd),
> + "ip netns exec %s nstat -asz %s | awk '%s' | grep -q '%s'",
> + NS_TEST, "MPTcpExtMPCapableSYNACKRX",
> + "NR==1 {next} {print $2}", "1");
The same thing here. Could you show the expected output with
ip netns exec %s nstat -asz %s
?
> + if (!ASSERT_OK(system(cmd), "No MPTcpExtMPCapableSYNACKRX found!"))
> + err++;
> +
> + return err;
> +}
> +
[...]
Hi Yonghong,
On Thu, Aug 03, 2023 at 06:23:57PM -0700, Yonghong Song wrote:
>
>
> On 8/3/23 6:41 AM, Geliang Tang wrote:
> > Implement a new test program mptcpify: if the family is AF_INET or
> > AF_INET6, the type is SOCK_STREAM, and the protocol ID is 0 or
> > IPPROTO_TCP, set it to IPPROTO_MPTCP. It will be hooked in
> > update_socket_protocol().
> >
> > Extend the MPTCP test base, add a selftest test_mptcpify() for the
> > mptcpify case. Open and load the mptcpify test prog to mptcpify the
> > TCP sockets dynamically, then use start_server() and connect_to_fd()
> > to create a TCP socket, but actually what's created is an MPTCP
> > socket, which can be verified through the outputs of 'ss' and 'nstat'
> > commands.
> >
> > Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
> > Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> > ---
> > .../testing/selftests/bpf/prog_tests/mptcp.c | 94 +++++++++++++++++++
> > tools/testing/selftests/bpf/progs/mptcpify.c | 25 +++++
> > 2 files changed, 119 insertions(+)
> > create mode 100644 tools/testing/selftests/bpf/progs/mptcpify.c
> >
> > diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> > index 4407bd5c9e9a..caab3aa6a162 100644
> > --- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
> > +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> > @@ -6,6 +6,7 @@
> > #include "cgroup_helpers.h"
> > #include "network_helpers.h"
> > #include "mptcp_sock.skel.h"
> > +#include "mptcpify.skel.h"
> > char NS_TEST[32];
> > @@ -195,8 +196,101 @@ static void test_base(void)
> > close(cgroup_fd);
> > }
> > +static void send_byte(int fd)
> > +{
> > + char b = 0x55;
> > +
> > + ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "send single byte");
> > +}
> > +
> > +static int verify_mptcpify(void)
> > +{
> > + char cmd[256];
> > + int err = 0;
> > +
> > + snprintf(cmd, sizeof(cmd),
> > + "ip netns exec %s ss -tOni | grep -q '%s'",
> > + NS_TEST, "tcp-ulp-mptcp");
>
> Could you show what is the expected output from the above command line
> ip netns exec %s ss -tOni
> ?
> This way, users can easily reason about the ss states based on tests.
There're too many items in the output of command 'ip netns exec %s ss -tOni':
'''
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
ESTAB 0 0 127.0.0.1:42225 127.0.0.1:44180 cubic wscale:7,7 rto:201 rtt:0.034/0.017 ato:40 mss:16640 pmtu:65535 rcvmss:536 advmss:65483 cwnd:10 bytes_received:1 segs_out:1 segs_in:3 data_segs_in:1 send 39152941176bps lastsnd:7 lastrcv:7 lastack:7 pacing_rate 78305882352bps delivered:1 app_limited rcv_space:33280 rcv_ssthresh:33280 minrtt:0.034 snd_wnd:33280 tcp-ulp-mptcp flags:Mec token:0000(id:0)/3a1e0d3c(id:0) seq:c2802f11c5228db6 sfseq:1 ssnoff:49d3c135 maplen:1
ESTAB 0 0 127.0.0.1:44180 127.0.0.1:42225 cubic wscale:7,7 rto:201 rtt:0.036/0.02 mss:16640 pmtu:65535 rcvmss:536 advmss:65483 cwnd:10 bytes_sent:1 bytes_acked:2 segs_out:3 segs_in:2 data_segs_out:1 send 36977777778bps lastsnd:7 lastrcv:7 lastack:7 pacing_rate 72200677960bps delivery_rate 8874666664bps delivered:2 rcv_space:33280 rcv_ssthresh:33280 minrtt:0.015 snd_wnd:33280 tcp-ulp-mptcp flags:Mmec token:0000(id:0)/39429ce(id:0) seq:e3ed00de37c805c sfseq:1 ssnoff:d4e4d561 maplen:0
'''
We only care about this 'tcp-ulp-mptcp' item.
Show all output will confuse users. So we just pick and test the only
item we care.
>
> > + if (!ASSERT_OK(system(cmd), "No tcp-ulp-mptcp found!"))
> > + err++;
> > +
> > + snprintf(cmd, sizeof(cmd),
> > + "ip netns exec %s nstat -asz %s | awk '%s' | grep -q '%s'",
> > + NS_TEST, "MPTcpExtMPCapableSYNACKRX",
> > + "NR==1 {next} {print $2}", "1");
>
> The same thing here. Could you show the expected output with
> ip netns exec %s nstat -asz %s
> ?
The output of 'ip netns exec %s nstat -asz %s' is:
'''
#kernel
MPTcpExtMPCapableSYNACKRX 1 0.0
'''
The same, we only check if it contains an MPTcpExtMPCapableSYNACKRX, not
show the output.
-Geliang
>
> > + if (!ASSERT_OK(system(cmd), "No MPTcpExtMPCapableSYNACKRX found!"))
> > + err++;
> > +
> > + return err;
> > +}
> > +
> [...]
On 8/3/23 7:24 PM, Geliang Tang wrote:
> Hi Yonghong,
>
> On Thu, Aug 03, 2023 at 06:23:57PM -0700, Yonghong Song wrote:
>>
>>
>> On 8/3/23 6:41 AM, Geliang Tang wrote:
>>> Implement a new test program mptcpify: if the family is AF_INET or
>>> AF_INET6, the type is SOCK_STREAM, and the protocol ID is 0 or
>>> IPPROTO_TCP, set it to IPPROTO_MPTCP. It will be hooked in
>>> update_socket_protocol().
>>>
>>> Extend the MPTCP test base, add a selftest test_mptcpify() for the
>>> mptcpify case. Open and load the mptcpify test prog to mptcpify the
>>> TCP sockets dynamically, then use start_server() and connect_to_fd()
>>> to create a TCP socket, but actually what's created is an MPTCP
>>> socket, which can be verified through the outputs of 'ss' and 'nstat'
>>> commands.
>>>
>>> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
>>> Signed-off-by: Geliang Tang <geliang.tang@suse.com>
>>> ---
>>> .../testing/selftests/bpf/prog_tests/mptcp.c | 94 +++++++++++++++++++
>>> tools/testing/selftests/bpf/progs/mptcpify.c | 25 +++++
>>> 2 files changed, 119 insertions(+)
>>> create mode 100644 tools/testing/selftests/bpf/progs/mptcpify.c
>>>
>>> diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
>>> index 4407bd5c9e9a..caab3aa6a162 100644
>>> --- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
>>> +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
>>> @@ -6,6 +6,7 @@
>>> #include "cgroup_helpers.h"
>>> #include "network_helpers.h"
>>> #include "mptcp_sock.skel.h"
>>> +#include "mptcpify.skel.h"
>>> char NS_TEST[32];
>>> @@ -195,8 +196,101 @@ static void test_base(void)
>>> close(cgroup_fd);
>>> }
>>> +static void send_byte(int fd)
>>> +{
>>> + char b = 0x55;
>>> +
>>> + ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "send single byte");
>>> +}
>>> +
>>> +static int verify_mptcpify(void)
>>> +{
>>> + char cmd[256];
>>> + int err = 0;
>>> +
>>> + snprintf(cmd, sizeof(cmd),
>>> + "ip netns exec %s ss -tOni | grep -q '%s'",
>>> + NS_TEST, "tcp-ulp-mptcp");
>>
>> Could you show what is the expected output from the above command line
>> ip netns exec %s ss -tOni
>> ?
>> This way, users can easily reason about the ss states based on tests.
>
> There're too many items in the output of command 'ip netns exec %s ss -tOni':
>
> '''
> State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
> ESTAB 0 0 127.0.0.1:42225 127.0.0.1:44180 cubic wscale:7,7 rto:201 rtt:0.034/0.017 ato:40 mss:16640 pmtu:65535 rcvmss:536 advmss:65483 cwnd:10 bytes_received:1 segs_out:1 segs_in:3 data_segs_in:1 send 39152941176bps lastsnd:7 lastrcv:7 lastack:7 pacing_rate 78305882352bps delivered:1 app_limited rcv_space:33280 rcv_ssthresh:33280 minrtt:0.034 snd_wnd:33280 tcp-ulp-mptcp flags:Mec token:0000(id:0)/3a1e0d3c(id:0) seq:c2802f11c5228db6 sfseq:1 ssnoff:49d3c135 maplen:1
> ESTAB 0 0 127.0.0.1:44180 127.0.0.1:42225 cubic wscale:7,7 rto:201 rtt:0.036/0.02 mss:16640 pmtu:65535 rcvmss:536 advmss:65483 cwnd:10 bytes_sent:1 bytes_acked:2 segs_out:3 segs_in:2 data_segs_out:1 send 36977777778bps lastsnd:7 lastrcv:7 lastack:7 pacing_rate 72200677960bps delivery_rate 8874666664bps delivered:2 rcv_space:33280 rcv_ssthresh:33280 minrtt:0.015 snd_wnd:33280 tcp-ulp-mptcp flags:Mmec token:0000(id:0)/39429ce(id:0) seq:e3ed00de37c805c sfseq:1 ssnoff:d4e4d561 maplen:0
> '''
>
> We only care about this 'tcp-ulp-mptcp' item.
>
> Show all output will confuse users. So we just pick and test the only
> item we care.
Thanks. Originally I thought at least we should put one line in
the comment which has 'tcp-ulp-mptcp' like
ESTAB 0 0 127.0.0.1:44180 127.0.0.1:42225 cubic
wscale:7,7 rto:201 rtt:0.036/0.02 mss:16640 pmtu:65535 rcvmss:536
advmss:65483 cwnd:10 bytes_sent:1 bytes_acked:2 segs_out:3 segs_in:2
data_segs_out:1 send 36977777778bps lastsnd:7 lastrcv:7 lastack:7
pacing_rate 72200677960bps delivery_rate 8874666664bps delivered:2
rcv_space:33280 rcv_ssthresh:33280 minrtt:0.015 snd_wnd:33280
tcp-ulp-mptcp flags:Mmec token:0000(id:0)/39429ce(id:0)
seq:e3ed00de37c805c sfseq:1 ssnoff:d4e4d561 maplen:0
or simplified version
ESTAB 0 0 127.0.0.1:44180 127.0.0.1:42225 cubic
... tcp-ulp-mptcp flags:Mmec ...
But people familiar with 'ss' should be able to dump it and get
the above (maybe without tcp-ulp-mptcp) easily. So I am okay
with no additional comments.
>
>>
>>> + if (!ASSERT_OK(system(cmd), "No tcp-ulp-mptcp found!"))
>>> + err++;
>>> +
>>> + snprintf(cmd, sizeof(cmd),
>>> + "ip netns exec %s nstat -asz %s | awk '%s' | grep -q '%s'",
>>> + NS_TEST, "MPTcpExtMPCapableSYNACKRX",
>>> + "NR==1 {next} {print $2}", "1");
>>
>> The same thing here. Could you show the expected output with
>> ip netns exec %s nstat -asz %s
>> ?
>
> The output of 'ip netns exec %s nstat -asz %s' is:
>
> '''
> #kernel
> MPTcpExtMPCapableSYNACKRX 1 0.0
> '''
>
> The same, we only check if it contains an MPTcpExtMPCapableSYNACKRX, not
> show the output.
>
> -Geliang
>
>>
>>> + if (!ASSERT_OK(system(cmd), "No MPTcpExtMPCapableSYNACKRX found!"))
>>> + err++;
>>> +
>>> + return err;
>>> +}
>>> +
>> [...]
On 8/3/23 6:41 AM, Geliang Tang wrote:
> Implement a new test program mptcpify: if the family is AF_INET or
> AF_INET6, the type is SOCK_STREAM, and the protocol ID is 0 or
> IPPROTO_TCP, set it to IPPROTO_MPTCP. It will be hooked in
> update_socket_protocol().
>
> Extend the MPTCP test base, add a selftest test_mptcpify() for the
> mptcpify case. Open and load the mptcpify test prog to mptcpify the
> TCP sockets dynamically, then use start_server() and connect_to_fd()
> to create a TCP socket, but actually what's created is an MPTCP
> socket, which can be verified through the outputs of 'ss' and 'nstat'
> commands.
>
> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
> Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> ---
> .../testing/selftests/bpf/prog_tests/mptcp.c | 94 +++++++++++++++++++
> tools/testing/selftests/bpf/progs/mptcpify.c | 25 +++++
> 2 files changed, 119 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/progs/mptcpify.c
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> index 4407bd5c9e9a..caab3aa6a162 100644
> --- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
> +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> @@ -6,6 +6,7 @@
> #include "cgroup_helpers.h"
> #include "network_helpers.h"
> #include "mptcp_sock.skel.h"
> +#include "mptcpify.skel.h"
>
> char NS_TEST[32];
>
> @@ -195,8 +196,101 @@ static void test_base(void)
> close(cgroup_fd);
> }
>
> +static void send_byte(int fd)
> +{
> + char b = 0x55;
> +
> + ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "send single byte");
> +}
> +
> +static int verify_mptcpify(void)
> +{
> + char cmd[256];
> + int err = 0;
> +
> + snprintf(cmd, sizeof(cmd),
> + "ip netns exec %s ss -tOni | grep -q '%s'",
> + NS_TEST, "tcp-ulp-mptcp");
> + if (!ASSERT_OK(system(cmd), "No tcp-ulp-mptcp found!"))
> + err++;
> +
> + snprintf(cmd, sizeof(cmd),
> + "ip netns exec %s nstat -asz %s | awk '%s' | grep -q '%s'",
> + NS_TEST, "MPTcpExtMPCapableSYNACKRX",
> + "NR==1 {next} {print $2}", "1");
> + if (!ASSERT_OK(system(cmd), "No MPTcpExtMPCapableSYNACKRX found!"))
> + err++;
> +
> + return err;
> +}
> +
> +static int run_mptcpify(int cgroup_fd)
> +{
> + int server_fd, client_fd, prog_fd, err = 0;
> + struct mptcpify *mptcpify_skel;
> +
> + mptcpify_skel = mptcpify__open_and_load();
> + if (!ASSERT_OK_PTR(mptcpify_skel, "skel_open_load"))
> + return -EIO;
> +
> + err = mptcpify__attach(mptcpify_skel);
> + if (!ASSERT_OK(err, "skel_attach"))
> + goto out;
> +
> + prog_fd = bpf_program__fd(mptcpify_skel->progs.mptcpify);
> + if (!ASSERT_GE(prog_fd, 0, "bpf_program__fd")) {
> + err = -EIO;
> + goto out;
> + }
load success means prog_fd is always valid. So above
ASSERT_GE not needed.
> +
> + /* without MPTCP */
> + server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
> + if (!ASSERT_GE(server_fd, 0, "start_server")) {
> + err = -EIO;
> + goto out;
> + }
> +
> + client_fd = connect_to_fd(server_fd, 0);
> + if (!ASSERT_GE(client_fd, 0, "connect to fd")) {
> + err = -EIO;
> + goto close_server;
> + }
> +
> + send_byte(client_fd);
> + err += verify_mptcpify();
> +
> + close(client_fd);
> +close_server:
> + close(server_fd);
> +out:
> + mptcpify__destroy(mptcpify_skel);
> + return err;
> +}
> +
> +static void test_mptcpify(void)
> +{
> + struct nstoken *nstoken = NULL;
> + int cgroup_fd;
> +
> + cgroup_fd = test__join_cgroup("/mptcpify");
> + if (!ASSERT_GE(cgroup_fd, 0, "test__join_cgroup"))
> + return;
> +
> + nstoken = create_netns();
> + if (!ASSERT_OK_PTR(nstoken, "create_netns"))
> + goto fail;
> +
> + ASSERT_OK(run_mptcpify(cgroup_fd), "run_mptcpify");
> +
> +fail:
> + cleanup_netns(nstoken);
> + close(cgroup_fd);
> +}
> +
> void test_mptcp(void)
> {
> if (test__start_subtest("base"))
> test_base();
> + if (test__start_subtest("mptcpify"))
> + test_mptcpify();
> }
> diff --git a/tools/testing/selftests/bpf/progs/mptcpify.c b/tools/testing/selftests/bpf/progs/mptcpify.c
> new file mode 100644
> index 000000000000..9cf1febe982d
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/mptcpify.c
> @@ -0,0 +1,25 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2023, SUSE. */
> +
> +#include <linux/bpf.h>
> +#include <bpf/bpf_tracing.h>
> +
> +char _license[] SEC("license") = "GPL";
> +
> +#define AF_INET 2
> +#define AF_INET6 10
> +#define SOCK_STREAM 1
> +#define IPPROTO_TCP 6
> +#define IPPROTO_MPTCP 262
To avoid the above macros, you can use
vmlinux.h and bpf_tracing_net.h.
> +
> +SEC("fmod_ret/update_socket_protocol")
> +int BPF_PROG(mptcpify, int family, int type, int protocol)
> +{
> + if ((family == AF_INET || family == AF_INET6) &&
> + type == SOCK_STREAM &&
> + (!protocol || protocol == IPPROTO_TCP)) {
> + return IPPROTO_MPTCP;
> + }
> +
> + return protocol;
> +}
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