Add self-contained test for NSS.

While at it fix interaction between __nss_configure_lookup and nscd.
Otherwise the test fails if nscd is runnung.

nss/nss_test1.c

@@ -0,0 +1,154 @@
+#include <errno.h>
+#include <nss.h>
+#include <pthread.h>
+#include <string.h>
+
+
+#define COPY_IF_ROOM(s) \
+  ({ size_t len_ = strlen (s) + 1;		\
+     char *start_ = cp;				\
+     buflen - (cp - buffer) < len_		\
+     ? NULL					\
+     : (cp = mempcpy (cp, s, len_), start_); })
+
+
+/* Password handling.  */
+#include <pwd.h>
+
+static struct passwd pwd_data[] =
+  {
+#define PWD(u) \
+    { .pw_name = (char *) "name" #u, .pw_passwd = (char *) "*", .pw_uid = u,  \
+      .pw_gid = 100, .pw_gecos = (char *) "*", .pw_dir = (char *) "*",	      \
+      .pw_shell = (char *) "*" }
+    PWD (100),
+    PWD (30),
+    PWD (200),
+    PWD (60),
+    PWD (20000)
+  };
+#define npwd_data (sizeof (pwd_data) / sizeof (pwd_data[0]))
+
+static size_t pwd_iter;
+#define CURPWD pwd_data[pwd_iter]
+
+static pthread_mutex_t pwd_lock = PTHREAD_MUTEX_INITIALIZER;
+
+
+enum nss_status
+_nss_test1_setpwent (int stayopen)
+{
+  pwd_iter = 0;
+  return NSS_STATUS_SUCCESS;
+}
+
+
+enum nss_status
+_nss_test1_endpwent (void)
+{
+  return NSS_STATUS_SUCCESS;
+}
+
+
+enum nss_status
+_nss_test1_getpwent_r (struct passwd *result, char *buffer, size_t buflen,
+		       int *errnop)
+{
+  char *cp = buffer;
+  int res = NSS_STATUS_SUCCESS;
+
+  pthread_mutex_lock (&pwd_lock);
+
+  if (pwd_iter >= npwd_data)
+    res = NSS_STATUS_NOTFOUND;
+  else
+    {
+      result->pw_name = COPY_IF_ROOM (CURPWD.pw_name);
+      result->pw_passwd = COPY_IF_ROOM (CURPWD.pw_passwd);
+      result->pw_uid = CURPWD.pw_uid;
+      result->pw_gid = CURPWD.pw_gid;
+      result->pw_gecos = COPY_IF_ROOM (CURPWD.pw_gecos);
+      result->pw_dir = COPY_IF_ROOM (CURPWD.pw_dir);
+      result->pw_shell = COPY_IF_ROOM (CURPWD.pw_shell);
+
+      if (result->pw_name == NULL || result->pw_passwd == NULL
+	  || result->pw_gecos == NULL || result->pw_dir == NULL
+	  || result->pw_shell == NULL)
+	{
+	  *errnop = ERANGE;
+	  res = NSS_STATUS_TRYAGAIN;
+	}
+
+      ++pwd_iter;
+    }
+
+  pthread_mutex_unlock (&pwd_lock);
+
+  return res;
+}
+
+
+enum nss_status
+_nss_test1_getpwuid_r (uid_t uid, struct passwd *result, char *buffer,
+		       size_t buflen, int *errnop)
+{
+  for (size_t idx = 0; idx < npwd_data; ++idx)
+    if (pwd_data[idx].pw_uid == uid)
+      {
+	char *cp = buffer;
+	int res = NSS_STATUS_SUCCESS;
+
+	result->pw_name = COPY_IF_ROOM (pwd_data[idx].pw_name);
+	result->pw_passwd = COPY_IF_ROOM (pwd_data[idx].pw_passwd);
+	result->pw_uid = pwd_data[idx].pw_uid;
+	result->pw_gid = pwd_data[idx].pw_gid;
+	result->pw_gecos = COPY_IF_ROOM (pwd_data[idx].pw_gecos);
+	result->pw_dir = COPY_IF_ROOM (pwd_data[idx].pw_dir);
+	result->pw_shell = COPY_IF_ROOM (pwd_data[idx].pw_shell);
+
+	if (result->pw_name == NULL || result->pw_passwd == NULL
+	    || result->pw_gecos == NULL || result->pw_dir == NULL
+	    || result->pw_shell == NULL)
+	  {
+	    *errnop = ERANGE;
+	    res = NSS_STATUS_TRYAGAIN;
+	  }
+
+	return res;
+      }
+
+  return NSS_STATUS_NOTFOUND;
+}
+
+
+enum nss_status
+_nss_test1_getpwnam_r (const char *name, struct passwd *result, char *buffer,
+		       size_t buflen, int *errnop)
+{
+  for (size_t idx = 0; idx < npwd_data; ++idx)
+    if (strcmp (pwd_data[idx].pw_name, name) == 0)
+      {
+	char *cp = buffer;
+	int res = NSS_STATUS_SUCCESS;
+
+	result->pw_name = COPY_IF_ROOM (pwd_data[idx].pw_name);
+	result->pw_passwd = COPY_IF_ROOM (pwd_data[idx].pw_passwd);
+	result->pw_uid = pwd_data[idx].pw_uid;
+	result->pw_gid = pwd_data[idx].pw_gid;
+	result->pw_gecos = COPY_IF_ROOM (pwd_data[idx].pw_gecos);
+	result->pw_dir = COPY_IF_ROOM (pwd_data[idx].pw_dir);
+	result->pw_shell = COPY_IF_ROOM (pwd_data[idx].pw_shell);
+
+	if (result->pw_name == NULL || result->pw_passwd == NULL
+	    || result->pw_gecos == NULL || result->pw_dir == NULL
+	    || result->pw_shell == NULL)
+	  {
+	    *errnop = ERANGE;
+	    res = NSS_STATUS_TRYAGAIN;
+	  }
+
+	return res;
+      }
+
+  return NSS_STATUS_NOTFOUND;
+}