Re: [PATCH v4 bpf-next 4/4] selftests/bpf: Add tests for bpf_sock_destroy

[Aditi Ghag <aditi.ghag@isovalent.com>]

> On Mar 29, 2023, at 4:13 PM, Aditi Ghag <aditi.ghag@isovalent.com> wrote:
> 
> 
> 
>> On Mar 28, 2023, at 11:35 AM, Stanislav Fomichev <sdf@google.com> wrote:
>> 
>> On Tue, Mar 28, 2023 at 10:51 AM Aditi Ghag <aditi.ghag@isovalent.com> wrote:
>>> 
>>> 
>>> 
>>>> On Mar 27, 2023, at 9:54 AM, Stanislav Fomichev <sdf@google.com> wrote:
>>>> 
>>>> On 03/27, Aditi Ghag wrote:
>>>> 
>>>> 
>>>>>> On Mar 24, 2023, at 2:52 PM, Stanislav Fomichev <sdf@google.com> wrote:
>>>>>> 
>>>>>> On 03/23, Aditi Ghag wrote:
>>>>>>> The test cases for destroying sockets mirror the intended usages of the
>>>>>>> bpf_sock_destroy kfunc using iterators.
>>>>>> 
>>>>>>> The destroy helpers set `ECONNABORTED` error code that we can validate in
>>>>>>> the test code with client sockets. But UDP sockets have an overriding error
>>>>>>> code from the disconnect called during abort, so the error code the
>>>>>>> validation is only done for TCP sockets.
>>>>>> 
>>>>>>> Signed-off-by: Aditi Ghag <aditi.ghag@isovalent.com>
>>>>>>> ---
>>>>>>> .../selftests/bpf/prog_tests/sock_destroy.c   | 195 ++++++++++++++++++
>>>>>>> .../selftests/bpf/progs/sock_destroy_prog.c   | 151 ++++++++++++++
>>>>>>> 2 files changed, 346 insertions(+)
>>>>>>> create mode 100644 tools/testing/selftests/bpf/prog_tests/sock_destroy.c
>>>>>>> create mode 100644 tools/testing/selftests/bpf/progs/sock_destroy_prog.c
>>>>>> 
>>>>>>> diff --git a/tools/testing/selftests/bpf/prog_tests/sock_destroy.c b/tools/testing/selftests/bpf/prog_tests/sock_destroy.c
>>>>>>> new file mode 100644
>>>>>>> index 000000000000..cbce966af568
>>>>>>> --- /dev/null
>>>>>>> +++ b/tools/testing/selftests/bpf/prog_tests/sock_destroy.c
>>>>>>> @@ -0,0 +1,195 @@
>>>>>>> +// SPDX-License-Identifier: GPL-2.0
>>>>>>> +#include <test_progs.h>
>>>>>>> +
>>>>>>> +#include "sock_destroy_prog.skel.h"
>>>>>>> +#include "network_helpers.h"
>>>>>>> +
>>>>>>> +#define SERVER_PORT 6062
>>>>>>> +
>>>>>>> +static void start_iter_sockets(struct bpf_program *prog)
>>>>>>> +{
>>>>>>> + struct bpf_link *link;
>>>>>>> + char buf[50] = {};
>>>>>>> + int iter_fd, len;
>>>>>>> +
>>>>>>> + link = bpf_program__attach_iter(prog, NULL);
>>>>>>> + if (!ASSERT_OK_PTR(link, "attach_iter"))
>>>>>>> +         return;
>>>>>>> +
>>>>>>> + iter_fd = bpf_iter_create(bpf_link__fd(link));
>>>>>>> + if (!ASSERT_GE(iter_fd, 0, "create_iter"))
>>>>>>> +         goto free_link;
>>>>>>> +
>>>>>>> + while ((len = read(iter_fd, buf, sizeof(buf))) > 0)
>>>>>>> +         ;
>>>>>>> + ASSERT_GE(len, 0, "read");
>>>>>>> +
>>>>>>> + close(iter_fd);
>>>>>>> +
>>>>>>> +free_link:
>>>>>>> + bpf_link__destroy(link);
>>>>>>> +}
>>>>>>> +
>>>>>>> +static void test_tcp_client(struct sock_destroy_prog *skel)
>>>>>>> +{
>>>>>>> + int serv = -1, clien = -1, n = 0;
>>>>>>> +
>>>>>>> + serv = start_server(AF_INET6, SOCK_STREAM, NULL, 0, 0);
>>>>>>> + if (!ASSERT_GE(serv, 0, "start_server"))
>>>>>>> +         goto cleanup_serv;
>>>>>>> +
>>>>>>> + clien = connect_to_fd(serv, 0);
>>>>>>> + if (!ASSERT_GE(clien, 0, "connect_to_fd"))
>>>>>>> +         goto cleanup_serv;
>>>>>>> +
>>>>>>> + serv = accept(serv, NULL, NULL);
>>>>>>> + if (!ASSERT_GE(serv, 0, "serv accept"))
>>>>>>> +         goto cleanup;
>>>>>>> +
>>>>>>> + n = send(clien, "t", 1, 0);
>>>>>>> + if (!ASSERT_GE(n, 0, "client send"))
>>>>>>> +         goto cleanup;
>>>>>>> +
>>>>>>> + /* Run iterator program that destroys connected client sockets. */
>>>>>>> + start_iter_sockets(skel->progs.iter_tcp6_client);
>>>>>>> +
>>>>>>> + n = send(clien, "t", 1, 0);
>>>>>>> + if (!ASSERT_LT(n, 0, "client_send on destroyed socket"))
>>>>>>> +         goto cleanup;
>>>>>>> + ASSERT_EQ(errno, ECONNABORTED, "error code on destroyed socket");
>>>>>>> +
>>>>>>> +
>>>>>>> +cleanup:
>>>>>>> + close(clien);
>>>>>>> +cleanup_serv:
>>>>>>> + close(serv);
>>>>>>> +}
>>>>>>> +
>>>>>>> +static void test_tcp_server(struct sock_destroy_prog *skel)
>>>>>>> +{
>>>>>>> + int serv = -1, clien = -1, n = 0;
>>>>>>> +
>>>>>>> + serv = start_server(AF_INET6, SOCK_STREAM, NULL, SERVER_PORT, 0);
>>>>>>> + if (!ASSERT_GE(serv, 0, "start_server"))
>>>>>>> +         goto cleanup_serv;
>>>>>>> +
>>>>>>> + clien = connect_to_fd(serv, 0);
>>>>>>> + if (!ASSERT_GE(clien, 0, "connect_to_fd"))
>>>>>>> +         goto cleanup_serv;
>>>>>>> +
>>>>>>> + serv = accept(serv, NULL, NULL);
>>>>>>> + if (!ASSERT_GE(serv, 0, "serv accept"))
>>>>>>> +         goto cleanup;
>>>>>>> +
>>>>>>> + n = send(clien, "t", 1, 0);
>>>>>>> + if (!ASSERT_GE(n, 0, "client send"))
>>>>>>> +         goto cleanup;
>>>>>>> +
>>>>>>> + /* Run iterator program that destroys server sockets. */
>>>>>>> + start_iter_sockets(skel->progs.iter_tcp6_server);
>>>>>>> +
>>>>>>> + n = send(clien, "t", 1, 0);
>>>>>>> + if (!ASSERT_LT(n, 0, "client_send on destroyed socket"))
>>>>>>> +         goto cleanup;
>>>>>>> + ASSERT_EQ(errno, ECONNRESET, "error code on destroyed socket");
>>>>>>> +
>>>>>>> +
>>>>>>> +cleanup:
>>>>>>> + close(clien);
>>>>>>> +cleanup_serv:
>>>>>>> + close(serv);
>>>>>>> +}
>>>>>>> +
>>>>>>> +
>>>>>>> +static void test_udp_client(struct sock_destroy_prog *skel)
>>>>>>> +{
>>>>>>> + int serv = -1, clien = -1, n = 0;
>>>>>>> +
>>>>>>> + serv = start_server(AF_INET6, SOCK_DGRAM, NULL, 6161, 0);
>>>>>>> + if (!ASSERT_GE(serv, 0, "start_server"))
>>>>>>> +         goto cleanup_serv;
>>>>>>> +
>>>>>>> + clien = connect_to_fd(serv, 0);
>>>>>>> + if (!ASSERT_GE(clien, 0, "connect_to_fd"))
>>>>>>> +         goto cleanup_serv;
>>>>>>> +
>>>>>>> + n = send(clien, "t", 1, 0);
>>>>>>> + if (!ASSERT_GE(n, 0, "client send"))
>>>>>>> +         goto cleanup;
>>>>>>> +
>>>>>>> + /* Run iterator program that destroys sockets. */
>>>>>>> + start_iter_sockets(skel->progs.iter_udp6_client);
>>>>>>> +
>>>>>>> + n = send(clien, "t", 1, 0);
>>>>>>> + if (!ASSERT_LT(n, 0, "client_send on destroyed socket"))
>>>>>>> +         goto cleanup;
>>>>>>> + /* UDP sockets have an overriding error code after they are disconnected,
>>>>>>> +  * so we don't check for ECONNABORTED error code.
>>>>>>> +  */
>>>>>>> +
>>>>>>> +cleanup:
>>>>>>> + close(clien);
>>>>>>> +cleanup_serv:
>>>>>>> + close(serv);
>>>>>>> +}
>>>>>>> +
>>>>>>> +static void test_udp_server(struct sock_destroy_prog *skel)
>>>>>>> +{
>>>>>>> + int *listen_fds = NULL, n, i;
>>>>>>> + unsigned int num_listens = 5;
>>>>>>> + char buf[1];
>>>>>>> +
>>>>>>> + /* Start reuseport servers. */
>>>>>>> + listen_fds = start_reuseport_server(AF_INET6, SOCK_DGRAM,
>>>>>>> +                                     "::1", SERVER_PORT, 0,
>>>>>>> +                                     num_listens);
>>>>>>> + if (!ASSERT_OK_PTR(listen_fds, "start_reuseport_server"))
>>>>>>> +         goto cleanup;
>>>>>>> +
>>>>>>> + /* Run iterator program that destroys server sockets. */
>>>>>>> + start_iter_sockets(skel->progs.iter_udp6_server);
>>>>>>> +
>>>>>>> + for (i = 0; i < num_listens; ++i) {
>>>>>>> +         n = read(listen_fds[i], buf, sizeof(buf));
>>>>>>> +         if (!ASSERT_EQ(n, -1, "read") ||
>>>>>>> +             !ASSERT_EQ(errno, ECONNABORTED, "error code on destroyed socket"))
>>>>>>> +                 break;
>>>>>>> + }
>>>>>>> + ASSERT_EQ(i, num_listens, "server socket");
>>>>>>> +
>>>>>>> +cleanup:
>>>>>>> + free_fds(listen_fds, num_listens);
>>>>>>> +}
>>>>>>> +
>>>>>>> +void test_sock_destroy(void)
>>>>>>> +{
>>>>>>> + int cgroup_fd = 0;
>>>>>>> + struct sock_destroy_prog *skel;
>>>>>>> +
>>>>>>> + skel = sock_destroy_prog__open_and_load();
>>>>>>> + if (!ASSERT_OK_PTR(skel, "skel_open"))
>>>>>>> +         return;
>>>>>>> +
>>>>>>> + cgroup_fd = test__join_cgroup("/sock_destroy");
>>>>>>> + if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup"))
>>>>>>> +         goto close_cgroup_fd;
>>>>>>> +
>>>>>>> + skel->links.sock_connect = bpf_program__attach_cgroup(
>>>>>>> +         skel->progs.sock_connect, cgroup_fd);
>>>>>>> + if (!ASSERT_OK_PTR(skel->links.sock_connect, "prog_attach"))
>>>>>>> +         goto close_cgroup_fd;
>>>>>>> +
>>>>>>> + if (test__start_subtest("tcp_client"))
>>>>>>> +         test_tcp_client(skel);
>>>>>>> + if (test__start_subtest("tcp_server"))
>>>>>>> +         test_tcp_server(skel);
>>>>>>> + if (test__start_subtest("udp_client"))
>>>>>>> +         test_udp_client(skel);
>>>>>>> + if (test__start_subtest("udp_server"))
>>>>>>> +         test_udp_server(skel);
>>>>>>> +
>>>>>>> +
>>>>>>> +close_cgroup_fd:
>>>>>>> + close(cgroup_fd);
>>>>>>> + sock_destroy_prog__destroy(skel);
>>>>>>> +}
>>>>>>> diff --git a/tools/testing/selftests/bpf/progs/sock_destroy_prog.c b/tools/testing/selftests/bpf/progs/sock_destroy_prog.c
>>>>>>> new file mode 100644
>>>>>>> index 000000000000..8e09d82c50f3
>>>>>>> --- /dev/null
>>>>>>> +++ b/tools/testing/selftests/bpf/progs/sock_destroy_prog.c
>>>>>>> @@ -0,0 +1,151 @@
>>>>>>> +// SPDX-License-Identifier: GPL-2.0
>>>>>>> +
>>>>>>> +#include "vmlinux.h"
>>>>>>> +
>>>>>>> +#include "bpf_tracing_net.h"
>>>>>>> +#include <bpf/bpf_helpers.h>
>>>>>>> +#include <bpf/bpf_endian.h>
>>>>>>> +
>>>>>>> +#define AF_INET6 10
>>>>>> 
>>>>>> [..]
>>>>>> 
>>>>>>> +/* Keep it in sync with prog_test/sock_destroy. */
>>>>>>> +#define SERVER_PORT 6062
>>>>>> 
>>>>>> The test looks good, one optional unrelated nit maybe:
>>>>>> 
>>>>>> I've been guilty of these hard-coded ports in the past, but maybe
>>>>>> we should stop hard-coding them? Getting the address of the listener (bound to
>>>>>> port 0) and passing it to the bpf program via global variable should be super
>>>>>> easy now (with the skeletons and network_helpers).
>>>> 
>>>> 
>>>>> I briefly considered adding the ports in a map, and retrieving them in the test. But it didn't seem worthwhile as the tests should fail clearly when there is a mismatch.
>>>> 
>>>> My worry is that the amount of those tests that have a hard-coded port
>>>> grows and at some point somebody will clash with somebody else.
>>>> And it might not be 100% apparent because test_progs is now multi-threaded
>>>> and racy..
>>>> 
>>> 
>>> So you would like the ports to be unique across all the tests.
>> 
>> Yeah, but it's hard without having some kind of global registry. Take
>> a look at the following:
>> 
>> $ grep -Iri _port tools/testing/selftests/bpf/ | grep -P '\d{4}'
>> 
>> tools/testing/selftests/bpf/progs/connect_force_port4.c:
>> sa.sin_port = bpf_htons(22222);
>> tools/testing/selftests/bpf/progs/connect_force_port4.c:        if
>> (ctx->user_port == bpf_htons(60000)) {
>> tools/testing/selftests/bpf/progs/connect_force_port4.c:
>> ctx->user_port = bpf_htons(60123);
>> tools/testing/selftests/bpf/progs/connect_force_port4.c:        if
>> (ctx->user_port == bpf_htons(60123)) {
>> tools/testing/selftests/bpf/progs/connect_force_port4.c:
>> ctx->user_port = bpf_htons(60000);
>> tools/testing/selftests/bpf/progs/connect_force_port4.c:        if
>> (ctx->user_port == bpf_htons(60123)) {
>> tools/testing/selftests/bpf/progs/connect6_prog.c:#define
>> DST_REWRITE_PORT6     6666
>> tools/testing/selftests/bpf/progs/test_sk_lookup.c:static const __u16
>> SRC_PORT = bpf_htons(8008);
>> tools/testing/selftests/bpf/progs/test_sk_lookup.c:static const __u16
>> DST_PORT = 7007; /* Host byte order */
>> tools/testing/selftests/bpf/progs/test_tc_dtime.c:      __u16
>> dst_ns_port = __bpf_htons(50000 + test);
>> tools/testing/selftests/bpf/progs/connect4_dropper.c:   if
>> (ctx->user_port == bpf_htons(60120))
>> tools/testing/selftests/bpf/progs/connect_force_port6.c:
>> sa.sin6_port = bpf_htons(22223);
>> tools/testing/selftests/bpf/progs/connect_force_port6.c:        if
>> (ctx->user_port == bpf_htons(60000)) {
>> tools/testing/selftests/bpf/progs/connect_force_port6.c:
>> ctx->user_port = bpf_htons(60124);
>> tools/testing/selftests/bpf/progs/connect_force_port6.c:        if
>> (ctx->user_port == bpf_htons(60124)) {
>> tools/testing/selftests/bpf/progs/connect_force_port6.c:
>> ctx->user_port = bpf_htons(60000);
>> tools/testing/selftests/bpf/progs/connect_force_port6.c:        if
>> (ctx->user_port == bpf_htons(60124)) {
>> tools/testing/selftests/bpf/progs/test_tunnel_kern.c:#define
>> VXLAN_UDP_PORT 4789
>> tools/testing/selftests/bpf/progs/sendmsg4_prog.c:#define DST_PORT
>>        4040
>> tools/testing/selftests/bpf/progs/sendmsg4_prog.c:#define
>> DST_REWRITE_PORT4     4444
>> tools/testing/selftests/bpf/progs/connect4_prog.c:#define
>> DST_REWRITE_PORT4     4444
>> tools/testing/selftests/bpf/progs/bind6_prog.c:#define SERV6_PORT
>>        6060
>> tools/testing/selftests/bpf/progs/bind6_prog.c:#define
>> SERV6_REWRITE_PORT       6666
>> tools/testing/selftests/bpf/progs/sendmsg6_prog.c:#define
>> DST_REWRITE_PORT6     6666
>> tools/testing/selftests/bpf/progs/recvmsg4_prog.c:#define SERV4_PORT
>>        4040
>> <cut>
>> 
>> .... there is much more ...
>> 
>>>> Getting the address of the listener (bound to
>>>> port 0) and passing it to the bpf program via global variable should be super
>>>> easy now (with the skeletons and network_helpers).
>>> 
>>> Just so that we are on the same page, could you point to which network helpers are you referring to here for passing global variables?
>> 
>> Take a look at the following existing tests:
>> * prog_tests/cgroup_skb_sk_lookup.c
>> * run_lookup_test(&skel->bss->g_serv_port, out_sk);
>> * progs/cgroup_skb_sk_lookup_kern.c
>> * g_serv_port
>> 
>> Fundamentally, here is what's preferable to have:
>> 
>> fd = start_server(..., port=0, ...);
>> listener_port = get_port(fd); /* new network_helpers.h helper that
>> calls getsockname */
>> obj->bss->port = listener_port; /* populate the port in the BPF program */
>> 
>> Does it make sense?
> 
> That makes sense. Good to know for future references. The client tests don't have hard-coded ports anyway, only the server tests do as they are using the so_resuseport option. You did mention that this was an optional nit, so I'll leave the hard-coded ports for the server tests for now. Hope that's reasonable.
> 

Looks like that shouldn't be a problem as you can pass port 0 to start_reuseport_server. I'll give this a shot, as it looks like a better option than contributing to the long list of hard-coded ports that you pointed out above. 

>> 
>>>>>> 
>>>>>> And, unrelated, maybe also fix a bunch of places where the reverse christmas
>>>>>> tree doesn't look reverse anymore?
>>>> 
>>>>> Ok. The checks should be part of tooling (e.g., checkpatch) though if they are meant to be enforced consistently, no?
>>>> 
>>>> They are networking specific, so they are not part of a checkpath :-(
>>>> I won't say they are consistently enforced, but we try to keep then
>>>> whenever possible.
>>>> 
>>>>>> 
>>>>>>> +
>>>>>>> +int bpf_sock_destroy(struct sock_common *sk) __ksym;
>>>>>>> +
>>>>>>> +struct {
>>>>>>> + __uint(type, BPF_MAP_TYPE_ARRAY);
>>>>>>> + __uint(max_entries, 1);
>>>>>>> + __type(key, __u32);
>>>>>>> + __type(value, __u64);
>>>>>>> +} tcp_conn_sockets SEC(".maps");
>>>>>>> +
>>>>>>> +struct {
>>>>>>> + __uint(type, BPF_MAP_TYPE_ARRAY);
>>>>>>> + __uint(max_entries, 1);
>>>>>>> + __type(key, __u32);
>>>>>>> + __type(value, __u64);
>>>>>>> +} udp_conn_sockets SEC(".maps");
>>>>>>> +
>>>>>>> +SEC("cgroup/connect6")
>>>>>>> +int sock_connect(struct bpf_sock_addr *ctx)
>>>>>>> +{
>>>>>>> + int key = 0;
>>>>>>> + __u64 sock_cookie = 0;
>>>>>>> + __u32 keyc = 0;
>>>>>>> +
>>>>>>> + if (ctx->family != AF_INET6 || ctx->user_family != AF_INET6)
>>>>>>> +         return 1;
>>>>>>> +
>>>>>>> + sock_cookie = bpf_get_socket_cookie(ctx);
>>>>>>> + if (ctx->protocol == IPPROTO_TCP)
>>>>>>> +         bpf_map_update_elem(&tcp_conn_sockets, &key, &sock_cookie, 0);
>>>>>>> + else if (ctx->protocol == IPPROTO_UDP)
>>>>>>> +         bpf_map_update_elem(&udp_conn_sockets, &keyc, &sock_cookie, 0);
>>>>>>> + else
>>>>>>> +         return 1;
>>>>>>> +
>>>>>>> + return 1;
>>>>>>> +}
>>>>>>> +
>>>>>>> +SEC("iter/tcp")
>>>>>>> +int iter_tcp6_client(struct bpf_iter__tcp *ctx)
>>>>>>> +{
>>>>>>> + struct sock_common *sk_common = ctx->sk_common;
>>>>>>> + struct seq_file *seq = ctx->meta->seq;
>>>>>>> + __u64 sock_cookie = 0;
>>>>>>> + __u64 *val;
>>>>>>> + int key = 0;
>>>>>>> +
>>>>>>> + if (!sk_common)
>>>>>>> +         return 0;
>>>>>>> +
>>>>>>> + if (sk_common->skc_family != AF_INET6)
>>>>>>> +         return 0;
>>>>>>> +
>>>>>>> + sock_cookie  = bpf_get_socket_cookie(sk_common);
>>>>>>> + val = bpf_map_lookup_elem(&tcp_conn_sockets, &key);
>>>>>>> + if (!val)
>>>>>>> +         return 0;
>>>>>>> + /* Destroy connected client sockets. */
>>>>>>> + if (sock_cookie == *val)
>>>>>>> +         bpf_sock_destroy(sk_common);
>>>>>>> +
>>>>>>> + return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +SEC("iter/tcp")
>>>>>>> +int iter_tcp6_server(struct bpf_iter__tcp *ctx)
>>>>>>> +{
>>>>>>> + struct sock_common *sk_common = ctx->sk_common;
>>>>>>> + struct seq_file *seq = ctx->meta->seq;
>>>>>>> + struct tcp6_sock *tcp_sk;
>>>>>>> + const struct inet_connection_sock *icsk;
>>>>>>> + const struct inet_sock *inet;
>>>>>>> + __u16 srcp;
>>>>>>> +
>>>>>>> + if (!sk_common)
>>>>>>> +         return 0;
>>>>>>> +
>>>>>>> + if (sk_common->skc_family != AF_INET6)
>>>>>>> +         return 0;
>>>>>>> +
>>>>>>> + tcp_sk = bpf_skc_to_tcp6_sock(sk_common);
>>>>>>> + if (!tcp_sk)
>>>>>>> +         return 0;
>>>>>>> +
>>>>>>> + icsk = &tcp_sk->tcp.inet_conn;
>>>>>>> + inet = &icsk->icsk_inet;
>>>>>>> + srcp = bpf_ntohs(inet->inet_sport);
>>>>>>> +
>>>>>>> + /* Destroy server sockets. */
>>>>>>> + if (srcp == SERVER_PORT)
>>>>>>> +         bpf_sock_destroy(sk_common);
>>>>>>> +
>>>>>>> + return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +
>>>>>>> +SEC("iter/udp")
>>>>>>> +int iter_udp6_client(struct bpf_iter__udp *ctx)
>>>>>>> +{
>>>>>>> + struct seq_file *seq = ctx->meta->seq;
>>>>>>> + struct udp_sock *udp_sk = ctx->udp_sk;
>>>>>>> + struct sock *sk = (struct sock *) udp_sk;
>>>>>>> + __u64 sock_cookie = 0, *val;
>>>>>>> + int key = 0;
>>>>>>> +
>>>>>>> + if (!sk)
>>>>>>> +         return 0;
>>>>>>> +
>>>>>>> + sock_cookie  = bpf_get_socket_cookie(sk);
>>>>>>> + val = bpf_map_lookup_elem(&udp_conn_sockets, &key);
>>>>>>> + if (!val)
>>>>>>> +         return 0;
>>>>>>> + /* Destroy connected client sockets. */
>>>>>>> + if (sock_cookie == *val)
>>>>>>> +         bpf_sock_destroy((struct sock_common *)sk);
>>>>>>> +
>>>>>>> + return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +SEC("iter/udp")
>>>>>>> +int iter_udp6_server(struct bpf_iter__udp *ctx)
>>>>>>> +{
>>>>>>> + struct seq_file *seq = ctx->meta->seq;
>>>>>>> + struct udp_sock *udp_sk = ctx->udp_sk;
>>>>>>> + struct sock *sk = (struct sock *) udp_sk;
>>>>>>> + __u16 srcp;
>>>>>>> + struct inet_sock *inet;
>>>>>>> +
>>>>>>> + if (!sk)
>>>>>>> +         return 0;
>>>>>>> +
>>>>>>> + inet = &udp_sk->inet;
>>>>>>> + srcp = bpf_ntohs(inet->inet_sport);
>>>>>>> + if (srcp == SERVER_PORT)
>>>>>>> +         bpf_sock_destroy((struct sock_common *)sk);
>>>>>>> +
>>>>>>> + return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +char _license[] SEC("license") = "GPL";
>>>>>>> --
>>>>>>> 2.34.1