6342 want signalfd support

Reviewed by: Patrick Mooney <patrick.mooney@joyent.com>
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Igor Kozhukhov <ikozhukhov@gmail.com>
Reviewed by: Garrett D'Amore <garrett@damore.org>
Approved by: Dan McDonald <danmcd@omniti.com>

1 files changed, 60 insertions, 0 deletions

diff --git a/usr/src/lib/libc/port/sys/signalfd.c b/usr/src/lib/libc/port/sys/signalfd.c
new file mode 100644
index 0000000000..0080c52bdf
--- /dev/null
+++ b/usr/src/lib/libc/port/sys/signalfd.c
@@ -0,0 +1,60 @@
+/*
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ */
+
+/*
+ * Copyright 2015, Joyent, Inc.
+ */
+
+#include <sys/signalfd.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+
+int
+signalfd(int fd, const sigset_t *mask, int flags)
+{
+	int origfd = fd;
+
+	if (fd == -1) {
+		int oflags = O_RDONLY;
+
+		if (flags & ~(SFD_NONBLOCK | SFD_CLOEXEC)) {
+			errno = EINVAL;
+			return (-1);
+		}
+
+		if (flags & SFD_NONBLOCK)
+			oflags |= O_NONBLOCK;
+
+		if (flags & SFD_CLOEXEC)
+			oflags |= O_CLOEXEC;
+
+		if ((fd = open("/dev/signalfd", oflags)) < 0)
+			return (-1);
+	}
+
+	if (ioctl(fd, SIGNALFDIOC_MASK, mask) != 0) {
+		if (origfd == -1) {
+			int old = errno;
+			(void) close(fd);
+			errno = old;
+		}
+		/*
+		 * Trying to modify an existing sigfd so if this failed
+		 * it's because it's not a valid fd or not a sigfd. ioctl
+		 * returns the correct errno for these cases.
+		 */
+		return (-1);
+	}
+
+	return (fd);
+}