1 files changed, 120 insertions, 0 deletions
diff --git a/soundserver/artswrapper.c b/soundserver/artswrapper.c
new file mode 100644
index 0000000..53cc56a
--- /dev/null
+++ b/soundserver/artswrapper.c
@@ -0,0 +1,120 @@
+#include <stdio.h>
+#include <sys/stat.h>
+#include <sys/resource.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdlib.h>
+
+/*
+ * adjust_priority
+ *
+ * sets realtime priority
+ */
+
+#include "config.h"
+
+#ifdef HAVE_REALTIME_SCHED
+#include <sched.h>
+
+void adjust_priority()
+{
+	int sched = sched_getscheduler(0);
+	if(sched == SCHED_FIFO || sched == SCHED_RR)
+	{
+		printf(">> since the scheduling policy is not standard, I assume\n");
+		printf("   it has been adjusted to fit the needs of realtime audio\n");
+	}
+	else
+	{
+		struct sched_param sp;
+		long priority = (sched_get_priority_max(SCHED_FIFO) +
+			             sched_get_priority_min(SCHED_FIFO))/2;
+		
+		sp.sched_priority = priority;
+
+		if(sched_setscheduler(0, SCHED_FIFO, &sp) != -1)
+		{
+			printf(">> running as realtime process now (priority %ld)\n",
+																	priority);
+			putenv("STARTED_THROUGH_ARTSWRAPPER=1");
+		}
+		else
+		{
+			/* can't set realtime priority */
+			putenv("STARTED_THROUGH_ARTSWRAPPER=2");
+		}
+	}
+}
+#else
+void adjust_priority()
+{
+	int prio;
+
+	prio = getpriority(PRIO_PROCESS,getpid());
+	if(prio > -10)
+	{
+		setpriority(PRIO_PROCESS,getpid(),-17);
+		prio = getpriority(PRIO_PROCESS,getpid());
+	}
+
+	/* no system support for realtime priority */
+	putenv("STARTED_THROUGH_ARTSWRAPPER=3");
+
+	if(prio > -10) {
+		printf(">> synthesizer priority is %d (which is unacceptable,",prio);
+		printf(" try running as root)\n");
+	}
+	else {
+		printf(">> synthesizer priority is %d (which is the best\n",prio);
+		printf("   we can get out of a non realtime system)\n");
+	}
+}
+#endif
+
+int main(int argc, char **argv)
+{
+	if(argc == 2)
+	{
+		if(strcmp(argv[1],"check") == 0)
+		{
+			/* backward compatibility with old artswrapper */
+			printf("okay\n");
+			return 0;
+		}
+	}
+
+	adjust_priority();
+
+	/* drop root privileges if running setuid root
+	   (due to realtime priority stuff) */
+	if (geteuid() != getuid()) 
+	{
+#if defined (HAVE_SETEUID) && !defined (HAVE_SETEUID_FAKE) 
+		seteuid(getuid());
+#else
+		setreuid(-1, getuid());
+#endif
+		if (geteuid() != getuid()) {
+			perror("setuid()");
+			return 2;
+		}
+	}
+
+	if(argc == 0)
+		return 1;
+
+/*
+ * Real-time status is passed to artsd via the environment variable
+ * STARTED_THROUGH_ARTSWRAPPER. It has one of the following values:
+ *
+ * unset - not running as real-time
+ * 1     - running as real-time
+ * 2     - no privileges to set real-time scheduling
+ * 3     - no support for real-time scheduling
+ */
+	argv[0] = EXECUTE;
+	execv(EXECUTE,argv);
+	perror(EXECUTE);
+	return 1;
+}