[PATCH v2 03/23] nscd: Enhance tst-nscd-basic with query counters

[Florian Weimer]

This helps to test that the cache is actually used.
---
 nscd/tst-nscd-basic.c  | 58 ++++++++++++++++++++++++++++++++++++++++++
 support/nscd_test.h    |  4 +++
 support/support_nscd.c | 33 ++++++++++++++++++++++++
 3 files changed, 95 insertions(+)

diff --git a/nscd/tst-nscd-basic.c b/nscd/tst-nscd-basic.c
index 2ce1fece60..3dfde92c36 100644
--- a/nscd/tst-nscd-basic.c
+++ b/nscd/tst-nscd-basic.c
@@ -31,6 +31,8 @@
 #include <support/xmemstream.h>
 #include <support/xstdio.h>
 
+#include <nscd/nscd-statdata.h>
+
 /* Large GECOS string for the large-gecos user.  */
 static char *large_gecos;
 
@@ -452,17 +454,73 @@ do_test (void)
   /* First run the tests without nscd running, to check that the test
      expectations are correct.  Use a separate process to avoid
      caching nscd availability.  */
+  puts ("info: testing without nscd");
   support_isolate_in_subprocess (all_tests, NULL);
 
   support_nscd_copy_configuration ();
 
   support_nscd_start ();
 
+  /* Initially the query counters are all zero.  */
+  {
+    struct statdata stat;
+    support_nscd_get_statistics (&stat);
+    for (int i = 0; i < lastdb; ++i)
+      {
+        TEST_COMPARE (stat.dbs[i].nentries, 0);
+        TEST_COMPARE (stat.dbs[i].poshit, 0);
+        TEST_COMPARE (stat.dbs[i].neghit, 0);
+        TEST_COMPARE (stat.dbs[i].posmiss, 0);
+        TEST_COMPARE (stat.dbs[i].negmiss, 0);
+      }
+  }
+
+  puts ("info: first pass with nscd");
   all_tests (NULL);
 
+  /* After running the tests, we have cache entries in all databases.
+   The counters have been empirically determined.  They mostly check
+   that nscd is actually used. */
+  struct statdata stat_first_pass;
+  support_nscd_get_statistics (&stat_first_pass);
+  TEST_COMPARE (stat_first_pass.dbs[pwddb].nentries, 10);
+  TEST_COMPARE (stat_first_pass.dbs[pwddb].posmiss, 4);
+  TEST_COMPARE (stat_first_pass.dbs[pwddb].negmiss, 2);
+  TEST_COMPARE (stat_first_pass.dbs[grpdb].nentries, 10);
+  TEST_COMPARE (stat_first_pass.dbs[grpdb].posmiss, 5);
+  TEST_COMPARE (stat_first_pass.dbs[grpdb].negmiss, 2);
+  TEST_COMPARE (stat_first_pass.dbs[hstdb].nentries, 5);
+  TEST_COMPARE (stat_first_pass.dbs[hstdb].posmiss, 5);
+  TEST_COMPARE (stat_first_pass.dbs[hstdb].negmiss, 0);
+  TEST_COMPARE (stat_first_pass.dbs[netgrdb].nentries, 25);
+  TEST_COMPARE (stat_first_pass.dbs[netgrdb].posmiss, 25);
+  TEST_COMPARE (stat_first_pass.dbs[netgrdb].negmiss, 0);
+  TEST_COMPARE (stat_first_pass.dbs[servdb].nentries, 5);
+  TEST_COMPARE (stat_first_pass.dbs[servdb].posmiss, 3);
+  TEST_COMPARE (stat_first_pass.dbs[servdb].negmiss, 2);
+
   /* Retry from cache.  */
+  puts ("info: second pass with nscd, with caching");
   all_tests (NULL);
 
+  /* Retries should have used the cache and not increment the query
+     counters.  This means that the shared mapping is used, not the
+     socket query interface or the in-process nss_files service
+     module.  */
+  {
+    struct statdata stat;
+    support_nscd_get_statistics (&stat);
+    for (int i = 0; i < lastdb; ++i)
+      {
+        TEST_COMPARE (stat.dbs[i].nentries, stat_first_pass.dbs[i].nentries);
+        TEST_COMPARE (stat.dbs[i].poshit, stat_first_pass.dbs[i].poshit);
+        TEST_COMPARE (stat.dbs[i].neghit, stat_first_pass.dbs[i].neghit);
+        TEST_COMPARE (stat.dbs[i].posmiss, stat_first_pass.dbs[i].posmiss);
+        TEST_COMPARE (stat.dbs[i].negmiss, stat_first_pass.dbs[i].negmiss);
+      }
+  }
+
+  puts ("info: pass with interleaved invalidation");
   invalidate = support_nscd_invalidate;
   all_tests (NULL);
 
diff --git a/support/nscd_test.h b/support/nscd_test.h
index 60208098f4..95d9c1cd38 100644
--- a/support/nscd_test.h
+++ b/support/nscd_test.h
@@ -36,4 +36,8 @@ void support_nscd_stop (void);
    services).  */
 void support_nscd_invalidate (const char *database);
 
+/* Fill in *STATS with data from the running nscd daemon.  */
+struct statdata;
+void support_nscd_get_statistics (struct statdata *stat);
+
 #endif /* SUPPORT_NSCD_TEST_H */
diff --git a/support/support_nscd.c b/support/support_nscd.c
index 2d7d503ad6..96d1e6b874 100644
--- a/support/support_nscd.c
+++ b/support/support_nscd.c
@@ -18,20 +18,25 @@
 
 #include <support/nscd_test.h>
 
+#include <errno.h>
 #include <libgen.h>
 #include <signal.h>
 #include <spawn.h>
 #include <stdbool.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <support/check.h>
 #include <support/support.h>
 #include <support/xspawn.h>
 #include <support/xunistd.h>
+#include <sys/socket.h>
+#include <sys/un.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
 #include <nscd/nscd.h>
 #include <nscd/nscd-client.h>
+#include <nscd/nscd-statdata.h>
 
 static pid_t nscd_pid;
 
@@ -113,3 +118,31 @@ support_nscd_invalidate (const char *database)
   TEST_COMPARE (system (cmd), 0);
   free (cmd);
 }
+
+void
+support_nscd_get_statistics (struct statdata *stat)
+{
+  struct sockaddr_un sun;
+  sun.sun_family = AF_UNIX;
+  strcpy (sun.sun_path, _PATH_NSCDSOCKET);
+
+  int sock = socket (PF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0);
+  if (sock < 0 || connect (sock, (struct sockaddr *) &sun, sizeof (sun)) < 0)
+    FAIL_EXIT1 ("failed to open nscd socket: %m");
+
+  request_header req;
+  req.version = NSCD_VERSION;
+  req.type = GETSTAT;
+  req.key_len = 0;
+
+  if (TEMP_FAILURE_RETRY (send (sock, &req, sizeof (req), MSG_NOSIGNAL))
+   != sizeof (req))
+    FAIL_EXIT1 ("failed to send request to nscd: %m");
+
+  ssize_t ret = TEMP_FAILURE_RETRY (recv (sock, stat, sizeof (*stat), 0));
+
+  errno = EMSGSIZE;
+  if (ret != sizeof (*stat) || stat->version != STATDATA_VERSION_FULL)
+    FAIL_EXIT1 ("failed to receive statistics from nscd: %m");
+  close (sock);
+}
-- 
2.53.0