1 files changed, 122 insertions, 0 deletions
diff --git a/lib/libc/resolv/res_state.c b/lib/libc/resolv/res_state.c
new file mode 100644
index 000000000000..9a0226a05ace
--- /dev/null
+++ b/lib/libc/resolv/res_state.c
@@ -0,0 +1,122 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2006 The FreeBSD Project. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+#include <resolv.h>
+#include <stdlib.h>
+
+#include "namespace.h"
+#include "reentrant.h"
+#include "un-namespace.h"
+
+#include "res_private.h"
+
+#undef _res
+
+struct __res_state _res;
+
+static thread_key_t res_key;
+static once_t res_init_once = ONCE_INITIALIZER;
+static int res_thr_keycreated = 0;
+
+static void
+free_res(void *ptr)
+{
+	res_state statp = ptr;
+
+	if (statp->_u._ext.ext != NULL)
+		res_ndestroy(statp);
+	free(statp);
+}
+
+static void
+res_keycreate(void)
+{
+	res_thr_keycreated = thr_keycreate(&res_key, free_res) == 0;
+}
+
+static res_state
+res_check_reload(res_state statp)
+{
+	struct timespec now;
+	struct stat sb;
+	struct __res_state_ext *ext;
+
+	if ((statp->options & RES_INIT) == 0) {
+		return (statp);
+	}
+
+	ext = statp->_u._ext.ext;
+	if (ext == NULL || ext->reload_period == 0) {
+		return (statp);
+	}
+
+	if (clock_gettime(CLOCK_MONOTONIC_FAST, &now) != 0 ||
+	    (now.tv_sec - ext->conf_stat) < ext->reload_period) {
+		return (statp);
+	}
+
+	ext->conf_stat = now.tv_sec;
+	if (stat(_PATH_RESCONF, &sb) == 0 &&
+	    (sb.st_mtim.tv_sec  != ext->conf_mtim.tv_sec ||
+	     sb.st_mtim.tv_nsec != ext->conf_mtim.tv_nsec)) {
+		statp->options &= ~RES_INIT;
+	}
+
+	return (statp);
+}
+
+res_state
+__res_state(void)
+{
+	res_state statp;
+
+	if (thr_main() != 0)
+		return res_check_reload(&_res);
+
+	if (thr_once(&res_init_once, res_keycreate) != 0 ||
+	    !res_thr_keycreated)
+		return (&_res);
+
+	statp = thr_getspecific(res_key);
+	if (statp != NULL)
+		return res_check_reload(statp);
+	statp = calloc(1, sizeof(*statp));
+	if (statp == NULL)
+		return (&_res);
+#ifdef __BIND_RES_TEXT
+	statp->options = RES_TIMEOUT;			/* Motorola, et al. */
+#endif
+	if (thr_setspecific(res_key, statp) == 0)
+		return (statp);
+	free(statp);
+	return (&_res);
+}