On Tue, Mar 28, 2023 at 10:51 AM Aditi Ghag <aditi.ghag@xxxxxxxxxxxxx> wrote:
>
>
>
> > On Mar 27, 2023, at 9:54 AM, Stanislav Fomichev <sdf@xxxxxxxxxx> wrote:
> >
> > On 03/27, Aditi Ghag wrote:
> >
> >
> >> > On Mar 24, 2023, at 2:52 PM, Stanislav Fomichev <sdf@xxxxxxxxxx> 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@xxxxxxxxxxxxx>
> >> >> ---
> >> >> .../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?
> >> >
> >> > 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
>
