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 `disconnect()` called during abort, so the error code
validation is only done for TCP sockets.
The failure test cases validate that the `bpf_sock_destroy` kfunc is not
allowed from program attach types other than BPF trace iterator, and
such programs fail to load.
Signed-off-by: Aditi Ghag <aditi.ghag@xxxxxxxxxxxxx>
---
.../selftests/bpf/prog_tests/sock_destroy.c | 221 ++++++++++++++++++
.../selftests/bpf/progs/sock_destroy_prog.c | 145 ++++++++++++
.../bpf/progs/sock_destroy_prog_fail.c | 22 ++
3 files changed, 388 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
create mode 100644 tools/testing/selftests/bpf/progs/sock_destroy_prog_fail.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..b0583309a94e
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/sock_destroy.c
@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+#include <bpf/bpf_endian.h>
+
+#include "sock_destroy_prog.skel.h"
+#include "sock_destroy_prog_fail.skel.h"
+#include "network_helpers.h"
+
+#define TEST_NS "sock_destroy_netns"
+
+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, accept_serv = -1, n;
+
+ serv = start_server(AF_INET6, SOCK_STREAM, NULL, 0, 0);
+ if (!ASSERT_GE(serv, 0, "start_server"))
+ goto cleanup;
+
+ clien = connect_to_fd(serv, 0);
+ if (!ASSERT_GE(clien, 0, "connect_to_fd"))
+ goto cleanup;
+
+ accept_serv = accept(serv, NULL, NULL);
+ if (!ASSERT_GE(accept_serv, 0, "serv accept"))
+ goto cleanup;
+
+ n = send(clien, "t", 1, 0);
+ if (!ASSERT_EQ(n, 1, "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:
+ if (clien != -1)
+ close(clien);
+ if (accept_serv != -1)
+ close(accept_serv);
+ if (serv != -1)
+ close(serv);
+}
+
+static void test_tcp_server(struct sock_destroy_prog *skel)
+{
+ int serv = -1, clien = -1, accept_serv = -1, n, serv_port;
+
+ serv = start_server(AF_INET6, SOCK_STREAM, NULL, 0, 0);
+ if (!ASSERT_GE(serv, 0, "start_server"))
+ goto cleanup;
+ serv_port = get_socket_local_port(serv);
+ if (!ASSERT_GE(serv_port, 0, "get_sock_local_port"))
+ goto cleanup;
+ skel->bss->serv_port = (__be16) serv_port;
+
+ clien = connect_to_fd(serv, 0);
+ if (!ASSERT_GE(clien, 0, "connect_to_fd"))
+ goto cleanup;
+
+ accept_serv = accept(serv, NULL, NULL);
+ if (!ASSERT_GE(accept_serv, 0, "serv accept"))
+ goto cleanup;
+
+ n = send(clien, "t", 1, 0);
+ if (!ASSERT_EQ(n, 1, "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:
+ if (clien != -1)
+ close(clien);
+ if (accept_serv != -1)
+ close(accept_serv);
+ if (serv != -1)
+ 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, 0, 0);
+ if (!ASSERT_GE(serv, 0, "start_server"))
+ goto cleanup;
+
+ clien = connect_to_fd(serv, 0);
+ if (!ASSERT_GE(clien, 0, "connect_to_fd"))
+ goto cleanup;
+
+ n = send(clien, "t", 1, 0);
+ if (!ASSERT_EQ(n, 1, "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:
+ if (clien != -1)
+ close(clien);
+ if (serv != -1)
+ close(serv);
+}
+
+static void test_udp_server(struct sock_destroy_prog *skel)
+{
+ int *listen_fds = NULL, n, i, serv_port;
+ unsigned int num_listens = 5;
+ char buf[1];
+
+ /* Start reuseport servers. */
+ listen_fds = start_reuseport_server(AF_INET6, SOCK_DGRAM,
+ "::1", 0, 0, num_listens);
+ if (!ASSERT_OK_PTR(listen_fds, "start_reuseport_server"))
+ goto cleanup;
+ serv_port = get_socket_local_port(listen_fds[0]);
+ if (!ASSERT_GE(serv_port, 0, "get_sock_local_port"))
+ goto cleanup;
+ skel->bss->serv_port = (__be16) serv_port;
+
+ /* 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)
+{
+ struct sock_destroy_prog *skel;
+ struct nstoken *nstoken = NULL;
+ int cgroup_fd;
+
+ 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 cleanup;
+
+ 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 cleanup;
+
+ SYS(cleanup, "ip netns add %s", TEST_NS);
+ SYS(cleanup, "ip -net %s link set dev lo up", TEST_NS);
+
+ nstoken = open_netns(TEST_NS);
+ if (!ASSERT_OK_PTR(nstoken, "open_netns"))
+ goto cleanup;
+
+ 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);
+
+ RUN_TESTS(sock_destroy_prog_fail);
+
+cleanup:
+ if (nstoken)
+ close_netns(nstoken);
+ SYS_NOFAIL("ip netns del " TEST_NS " &> /dev/null");
+ if (cgroup_fd >= 0)
+ 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..9e0bf7a54cec
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/sock_destroy_prog.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#include "bpf_tracing_net.h"
+
+__be16 serv_port = 0;
+
+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)
+{
+ __u64 sock_cookie = 0;
+ int key = 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;
+ __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;
+ const struct inet_connection_sock *icsk;
+ const struct inet_sock *inet;
+ struct tcp6_sock *tcp_sk;
+ __be16 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 = inet->inet_sport;
+
+ /* Destroy server sockets. */
+ if (srcp == serv_port)
+ bpf_sock_destroy(sk_common);
+
+ return 0;
+}
+
+
+SEC("iter/udp")
+int iter_udp6_client(struct bpf_iter__udp *ctx)
+{
+ 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 udp_sock *udp_sk = ctx->udp_sk;
+ struct sock *sk = (struct sock *) udp_sk;
+ struct inet_sock *inet;
+ __be16 srcp;
+
+ if (!sk)
+ return 0;
+
+ inet = &udp_sk->inet;
+ srcp = inet->inet_sport;
+ if (srcp == serv_port)
+ bpf_sock_destroy((struct sock_common *)sk);
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/sock_destroy_prog_fail.c b/tools/testing/selftests/bpf/progs/sock_destroy_prog_fail.c
new file mode 100644
index 000000000000..dd6850b58e25
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/sock_destroy_prog_fail.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+
+#include "bpf_misc.h"
+
+char _license[] SEC("license") = "GPL";
+
+int bpf_sock_destroy(struct sock_common *sk) __ksym;
+
+SEC("tp_btf/tcp_destroy_sock")
+__failure __msg("calling kernel function bpf_sock_destroy is not allowed")
+int BPF_PROG(trace_tcp_destroy_sock, struct sock *sk)
+{
+ /* should not load */
+ bpf_sock_destroy((struct sock_common *)sk);
+
+ return 0;
+}
+
--
2.34.1
