tests: add a helper that dumps /run/utmp in detail

utmpdump doesn't print all the details. Looking at the list if useful
when trying to tweak the wall filtering logic.

This doesn't do much, but at least it serves as a smoke test for the cleanup
functions.

1 files changed, 61 insertions, 0 deletions

diff --git a/src/test/test-utmp.c b/src/test/test-utmp.c
new file mode 100644
index 0000000000..2f66003e65
--- /dev/null
+++ b/src/test/test-utmp.c
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "format-util.h"
+#include "socket-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "utmp-wtmp.h"
+#include "tests.h"
+
+#ifndef UT_LINESIZE
+#  define UT_LINESIZE      32
+#endif
+#ifndef UT_NAMESIZE
+#  define UT_NAMESIZE      32
+#endif
+#ifndef UT_HOSTSIZE
+#  define UT_HOSTSIZE     256
+#endif
+
+TEST(dump_run_utmp) {
+        _unused_ _cleanup_(utxent_cleanup) bool utmpx = false;
+
+        utmpx = utxent_start();
+
+        for (struct utmpx *u; (u = getutxent()); ) {
+                char _type_buf[DECIMAL_STR_MAX(short)];
+                const char *type =
+                        u->ut_type == EMPTY         ? "EMPTY" :
+                        u->ut_type == RUN_LVL       ? "RUN_LVL" :
+                        u->ut_type == BOOT_TIME     ? "BOOT_TIME" :
+                        u->ut_type == NEW_TIME      ? "NEW_TIME" :
+                        u->ut_type == OLD_TIME      ? "OLD_TIME" :
+                        u->ut_type == INIT_PROCESS  ? "INIT_PROCESS" :
+                        u->ut_type == LOGIN_PROCESS ? "LOGIN_PROCESS" :
+                        u->ut_type == USER_PROCESS  ? "USER_PROCESS" :
+                        u->ut_type == DEAD_PROCESS  ? "DEAD_PROCESS" :
+                        u->ut_type == ACCOUNTING    ? "ACCOUNTING" :
+                        _type_buf;
+                if (type == _type_buf)
+                        xsprintf(_type_buf, "%hd", u->ut_type);
+
+                union in_addr_union addr = {};
+                memcpy(&addr, u->ut_addr_v6, MIN(sizeof(addr), sizeof(u->ut_addr_v6)));
+                _cleanup_free_ char *pretty = NULL;
+                bool is_ipv4 = memeqzero((const uint8_t*) &addr + 4, sizeof(addr) - 4);
+                (void) in_addr_to_string(is_ipv4 ? AF_INET : AF_INET6,
+                                         &addr, &pretty);
+
+                log_info("%14s %10"PID_PRI" line=%-7.*s id=%-4.4s name=%-8.*s session=%lu host=%.*s addr=%s",
+                         type,
+                         u->ut_pid,
+                         UT_LINESIZE, u->ut_line,
+                         u->ut_id,
+                         UT_NAMESIZE, u->ut_user,
+                         (long unsigned) u->ut_session,
+                         UT_HOSTSIZE, u->ut_host,
+                         strempty(pretty));
+        }
+}
+
+DEFINE_TEST_MAIN(LOG_DEBUG);