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-rw-r--r--src/test/test-bpf.c178
1 files changed, 178 insertions, 0 deletions
diff --git a/src/test/test-bpf.c b/src/test/test-bpf.c
new file mode 100644
index 0000000..cd8d68f
--- /dev/null
+++ b/src/test/test-bpf.c
@@ -0,0 +1,178 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <linux/libbpf.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include "bpf-firewall.h"
+#include "bpf-program.h"
+#include "load-fragment.h"
+#include "manager.h"
+#include "rm-rf.h"
+#include "service.h"
+#include "test-helper.h"
+#include "tests.h"
+#include "unit.h"
+
+/* We use the same limit here that PID 1 bumps RLIMIT_MEMLOCK to if it can */
+#define CAN_MEMLOCK_SIZE (64U*1024U*1024U)
+
+static bool can_memlock(void) {
+ void *p;
+ bool b;
+
+ /* Let's see if we can mlock() a larger blob of memory. BPF programs are charged against
+ * RLIMIT_MEMLOCK, hence let's first make sure we can lock memory at all, and skip the test if we
+ * cannot. Why not check RLIMIT_MEMLOCK explicitly? Because in container environments the
+ * RLIMIT_MEMLOCK value we see might not match the RLIMIT_MEMLOCK value actually in effect. */
+
+ p = mmap(NULL, CAN_MEMLOCK_SIZE, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_SHARED, -1, 0);
+ if (p == MAP_FAILED)
+ return false;
+
+ b = mlock(p, CAN_MEMLOCK_SIZE) >= 0;
+ if (b)
+ assert_se(munlock(p, CAN_MEMLOCK_SIZE) >= 0);
+
+ assert_se(munmap(p, CAN_MEMLOCK_SIZE) >= 0);
+ return b;
+}
+
+int main(int argc, char *argv[]) {
+ struct bpf_insn exit_insn[] = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN()
+ };
+
+ _cleanup_(rm_rf_physical_and_freep) char *runtime_dir = NULL;
+ CGroupContext *cc = NULL;
+ _cleanup_(bpf_program_unrefp) BPFProgram *p = NULL;
+ _cleanup_(manager_freep) Manager *m = NULL;
+ Unit *u;
+ char log_buf[65535];
+ struct rlimit rl;
+ int r;
+
+ test_setup_logging(LOG_DEBUG);
+
+ if (is_run_on_travis_ci())
+ return log_tests_skipped("test-bpf fails on Travis CI: https://github.com/systemd/systemd/issues/9666");
+
+ assert_se(getrlimit(RLIMIT_MEMLOCK, &rl) >= 0);
+ rl.rlim_cur = rl.rlim_max = MAX3(rl.rlim_cur, rl.rlim_max, CAN_MEMLOCK_SIZE);
+ (void) setrlimit(RLIMIT_MEMLOCK, &rl);
+
+ if (!can_memlock())
+ return log_tests_skipped("Can't use mlock(), skipping.");
+
+ r = enter_cgroup_subroot();
+ if (r == -ENOMEDIUM)
+ return log_tests_skipped("cgroupfs not available");
+
+ assert_se(set_unit_path(get_testdata_dir()) >= 0);
+ assert_se(runtime_dir = setup_fake_runtime_dir());
+
+ r = bpf_program_new(BPF_PROG_TYPE_CGROUP_SKB, &p);
+ assert(r == 0);
+
+ r = bpf_program_add_instructions(p, exit_insn, ELEMENTSOF(exit_insn));
+ assert(r == 0);
+
+ if (getuid() != 0)
+ return log_tests_skipped("not running as root");
+
+ r = bpf_firewall_supported();
+ if (r == BPF_FIREWALL_UNSUPPORTED)
+ return log_tests_skipped("BPF firewalling not supported");
+ assert_se(r > 0);
+
+ if (r == BPF_FIREWALL_SUPPORTED_WITH_MULTI)
+ log_notice("BPF firewalling with BPF_F_ALLOW_MULTI supported. Yay!");
+ else
+ log_notice("BPF firewalling (though without BPF_F_ALLOW_MULTI) supported. Good.");
+
+ r = bpf_program_load_kernel(p, log_buf, ELEMENTSOF(log_buf));
+ assert(r >= 0);
+
+ p = bpf_program_unref(p);
+
+ /* The simple tests suceeded. Now let's try full unit-based use-case. */
+
+ assert_se(manager_new(UNIT_FILE_USER, MANAGER_TEST_RUN_BASIC, &m) >= 0);
+ assert_se(manager_startup(m, NULL, NULL) >= 0);
+
+ assert_se(u = unit_new(m, sizeof(Service)));
+ assert_se(unit_add_name(u, "foo.service") == 0);
+ assert_se(cc = unit_get_cgroup_context(u));
+ u->perpetual = true;
+
+ cc->ip_accounting = true;
+
+ assert_se(config_parse_ip_address_access(u->id, "filename", 1, "Service", 1, "IPAddressAllow", 0, "10.0.1.0/24", &cc->ip_address_allow, NULL) == 0);
+ assert_se(config_parse_ip_address_access(u->id, "filename", 1, "Service", 1, "IPAddressAllow", 0, "127.0.0.2", &cc->ip_address_allow, NULL) == 0);
+ assert_se(config_parse_ip_address_access(u->id, "filename", 1, "Service", 1, "IPAddressDeny", 0, "127.0.0.3", &cc->ip_address_deny, NULL) == 0);
+ assert_se(config_parse_ip_address_access(u->id, "filename", 1, "Service", 1, "IPAddressDeny", 0, "10.0.3.2/24", &cc->ip_address_deny, NULL) == 0);
+ assert_se(config_parse_ip_address_access(u->id, "filename", 1, "Service", 1, "IPAddressDeny", 0, "127.0.0.1/25", &cc->ip_address_deny, NULL) == 0);
+ assert_se(config_parse_ip_address_access(u->id, "filename", 1, "Service", 1, "IPAddressDeny", 0, "127.0.0.4", &cc->ip_address_deny, NULL) == 0);
+
+ assert(cc->ip_address_allow);
+ assert(cc->ip_address_allow->items_next);
+ assert(!cc->ip_address_allow->items_next->items_next);
+
+ /* The deny list is defined redundantly, let's ensure it got properly reduced */
+ assert(cc->ip_address_deny);
+ assert(cc->ip_address_deny->items_next);
+ assert(!cc->ip_address_deny->items_next->items_next);
+
+ assert_se(config_parse_exec(u->id, "filename", 1, "Service", 1, "ExecStart", SERVICE_EXEC_START, "/bin/ping -c 1 127.0.0.2 -W 5", SERVICE(u)->exec_command, u) == 0);
+ assert_se(config_parse_exec(u->id, "filename", 1, "Service", 1, "ExecStart", SERVICE_EXEC_START, "/bin/ping -c 1 127.0.0.3 -W 5", SERVICE(u)->exec_command, u) == 0);
+
+ assert_se(SERVICE(u)->exec_command[SERVICE_EXEC_START]);
+ assert_se(SERVICE(u)->exec_command[SERVICE_EXEC_START]->command_next);
+ assert_se(!SERVICE(u)->exec_command[SERVICE_EXEC_START]->command_next->command_next);
+
+ SERVICE(u)->type = SERVICE_ONESHOT;
+ u->load_state = UNIT_LOADED;
+
+ unit_dump(u, stdout, NULL);
+
+ r = bpf_firewall_compile(u);
+ if (IN_SET(r, -ENOTTY, -ENOSYS, -EPERM))
+ return log_tests_skipped("Kernel doesn't support the necessary bpf bits (masked out via seccomp?)");
+ assert_se(r >= 0);
+
+ assert(u->ip_bpf_ingress);
+ assert(u->ip_bpf_egress);
+
+ r = bpf_program_load_kernel(u->ip_bpf_ingress, log_buf, ELEMENTSOF(log_buf));
+
+ log_notice("log:");
+ log_notice("-------");
+ log_notice("%s", log_buf);
+ log_notice("-------");
+
+ assert(r >= 0);
+
+ r = bpf_program_load_kernel(u->ip_bpf_egress, log_buf, ELEMENTSOF(log_buf));
+
+ log_notice("log:");
+ log_notice("-------");
+ log_notice("%s", log_buf);
+ log_notice("-------");
+
+ assert(r >= 0);
+
+ assert_se(unit_start(u) >= 0);
+
+ while (!IN_SET(SERVICE(u)->state, SERVICE_DEAD, SERVICE_FAILED))
+ assert_se(sd_event_run(m->event, UINT64_MAX) >= 0);
+
+ assert_se(SERVICE(u)->exec_command[SERVICE_EXEC_START]->exec_status.code == CLD_EXITED &&
+ SERVICE(u)->exec_command[SERVICE_EXEC_START]->exec_status.status == EXIT_SUCCESS);
+
+ assert_se(SERVICE(u)->exec_command[SERVICE_EXEC_START]->command_next->exec_status.code != CLD_EXITED ||
+ SERVICE(u)->exec_command[SERVICE_EXEC_START]->command_next->exec_status.status != EXIT_SUCCESS);
+
+ return 0;
+}
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