Add rtems_mdns_sethostname()

Use it to set the multi-cast hostname of the default mDNS resolver
instance via sethostname().

Makefile

@@ -102,6 +102,7 @@ LIB_C_FILES += rtemsbsd/rtems/rtems-syslog-initialize.c
 LIB_C_FILES += rtemsbsd/rtems/syslog.c
 LIB_C_FILES += rtemsbsd/ftpd/ftpd.c
 LIB_C_FILES += rtemsbsd/mdns/mdns.c
+LIB_C_FILES += rtemsbsd/mdns/mdns-sethostname-default.c
 LIB_C_FILES += rtemsbsd/pppd/auth.c
 LIB_C_FILES += rtemsbsd/pppd/ccp.c
 LIB_C_FILES += rtemsbsd/pppd/chap.c

freebsd-to-rtems.py

@@ -700,6 +700,7 @@ rtems.addRTEMSSourceFiles(
 		'rtems/syslog.c',
 		'ftpd/ftpd.c',
 		'mdns/mdns.c',
+		'mdns/mdns-sethostname-default.c',
 		'pppd/auth.c',
 		'pppd/ccp.c',
 		'pppd/chap.c',

freebsd/sys/kern/kern_mib.c

@@ -56,6 +56,9 @@ __FBSDID("$FreeBSD$");
 #include <sys/smp.h>
 #include <sys/sx.h>
 #include <rtems/bsd/sys/unistd.h>
+#ifdef __rtems__
+#include <rtems/mdns.h>
+#endif /* __rtems__ */
 
 SYSCTL_NODE(, 0,	  sysctl, CTLFLAG_RW, 0,
 	"Sysctl internal magic");
@@ -326,6 +329,10 @@ sysctl_hostname(SYSCTL_HANDLER_ARGS)
 #else /* __rtems__ */
 		(void) cpr;
 		(void) descend;
+
+		if (pr_offset == offsetof(struct prison, pr_hostname)) {
+			rtems_mdns_sethostname(tmpname);
+		}
 #endif /* __rtems__ */
 		mtx_unlock(&pr->pr_mtx);
 #ifndef __rtems__

rtemsbsd/include/rtems/mdns.h

@@ -40,6 +40,9 @@
 extern "C" {
 #endif /* __cplusplus */
 
+/* Private variable, do not touch.  Use rtems_mdns_sethostname() instead. */
+extern void (*rtems_mdns_sethostname_handler)(const char *hostname);
+
 /**
  * @brief Initializes an mDNS resolver instance.
  *
@@ -67,6 +70,20 @@ rtems_status_code rtems_mdns_initialize(rtems_task_priority daemon_priority,
  */
 mDNS *rtems_mdns_get_instance(void);
 
+/**
+ * @brief Sets the multi-cast hostname of the mDNS resolver instance.
+ *
+ * In case the mDNS resolver instance is not initialized, then this function
+ * has no effect.
+ *
+ * @param[in] hostname The new multi-cast hostname.
+ */
+static inline void
+rtems_mdns_sethostname(const char *hostname)
+{
+  (*rtems_mdns_sethostname_handler)(hostname);
+}
+
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */

rtemsbsd/mdns/mdns-sethostname-default.c

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2014 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * 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 <rtems/mdns.h>
+
+static void
+mdns_sethostname_default(const char *hostname)
+{
+	/* Do nothing */
+}
+
+void (*rtems_mdns_sethostname_handler)(const char *hostname) =
+    mdns_sethostname_default;

rtemsbsd/mdns/mdns.c

@@ -31,6 +31,7 @@
 
 #include <mDNSEmbeddedAPI.h>
 #include <mDNSPosix.h>
+#include <DNSCommon.h>
 
 #include <sys/select.h>
 #include <sys/socket.h>
@@ -54,7 +55,7 @@
 #include <rtems/bsd/util.h>
 #include <rtems/mdns.h>
 
-static rtems_id daemon_id;
+static rtems_id mdns_daemon_id;
 
 static mDNS mDNSStorage;
 
@@ -223,7 +224,7 @@ mdns_gethostbyname(void *rval, void *cb_data, va_list ap)
 	ctx.task_id = rtems_task_self();
 
 	mDNS_StartQuery(&mDNSStorage, &q);
-	rtems_bsd_force_select_timeout(daemon_id);
+	rtems_bsd_force_select_timeout(mdns_daemon_id);
 
 	sc = rtems_event_transient_receive(RTEMS_WAIT,
 	    10 * rtems_clock_get_ticks_per_second());
@@ -261,6 +262,36 @@ mdns_daemon(rtems_task_argument arg)
 	}
 }
 
+static void
+truncate_at_first_dot(domainlabel *name)
+{
+	int c = name->c[0];
+	int n = 0;
+
+	while (n < c && name->c[n + 1] != '.') {
+		++n;
+	}
+
+	name->c[0] = n;
+}
+
+static void
+mdns_sethostname(const char *hostname)
+{
+	mDNS *m = &mDNSStorage;
+
+	mDNS_Lock(m);
+
+	MakeDomainLabelFromLiteralString(&m->hostlabel, hostname);
+	truncate_at_first_dot(&m->hostlabel);
+
+	mDNS_Unlock(m);
+
+	mDNS_SetFQDN(m);
+
+	rtems_bsd_force_select_timeout(mdns_daemon_id);
+}
+
 rtems_status_code
 rtems_mdns_initialize(rtems_task_priority daemon_priority,
     CacheEntity *rrcachestorage, mDNSu32 rrcachesize)
@@ -279,12 +310,12 @@ rtems_mdns_initialize(rtems_task_priority daemon_priority,
 
 	sc = rtems_task_create(rtems_build_name('m', 'D', 'N', 'S'),
 	    daemon_priority, 16 * 1024, RTEMS_DEFAULT_MODES,
-	    RTEMS_DEFAULT_ATTRIBUTES, &daemon_id);
+	    RTEMS_DEFAULT_ATTRIBUTES, &mdns_daemon_id);
 	if (sc != RTEMS_SUCCESSFUL) {
 		return (RTEMS_UNSATISFIED);
 	}
 
-	sc = rtems_task_start(daemon_id, mdns_daemon, 0);
+	sc = rtems_task_start(mdns_daemon_id, mdns_daemon, 0);
 	if (sc != RTEMS_SUCCESSFUL) {
 		return (RTEMS_UNSATISFIED);
 	}
@@ -311,6 +342,8 @@ rtems_mdns_initialize(rtems_task_priority daemon_priority,
 		}
 	}
 
+	rtems_mdns_sethostname_handler = mdns_sethostname;
+
 	return (RTEMS_SUCCESSFUL);
 }