add core select() routine and (un-)registration functions

2 files changed, 101 insertions, 0 deletions

diff --git a/include/ulogd/select.h b/include/ulogd/select.h
new file mode 100644
index 0000000..9562a6e
--- /dev/null
+++ b/include/ulogd/select.h
@@ -0,0 +1,20 @@
+#ifndef ULOGD_SELECT_H
+#define ULOGD_SELECT_H
+
+#define ULOGD_FD_F_READ		0x0001
+#define ULOGD_FD_F_WRITE	0x0002
+
+struct ulogd_fd {
+	struct list_head list;
+	int fd;
+	unsigned int flags;
+	void *data;
+	int (*cb)(int fd, int flags, void *data);
+};
+
+
+int ulogd_register_fd(struct ulogd_fd *fd);
+int ulogd_unregister_fd(struct ulogd_fd *fd);
+int ulogd_select_main();
+
+#endif
diff --git a/select.c b/select.c
new file mode 100644
index 0000000..941600b
--- /dev/null
+++ b/select.c
@@ -0,0 +1,81 @@
+/* ulogd, Version $LastChangedRevision: 476 $
+ *
+ * $Id: ulogd.c 476 2004-07-23 03:19:35Z laforge $
+ *
+ * userspace logging daemon for the iptables ULOG target
+ * of the linux 2.4 netfilter subsystem.
+ *
+ * (C) 2000-2003 by Harald Welte <laforge@gnumonks.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 
+ *  as published by the Free Software Foundation
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+static maxfd = 0;
+static list_head ulogd_fds;
+
+int ulogd_register_fd(struct ulogd_fd *fd)
+{
+	int flags;
+
+	/* make FD nonblocking */
+	flags = fcntl(fd->fd, F_GETFL);
+	if (flags < 0)
+		return -1;
+	flags |= O_NONBLOCK;
+	flags = fcntl(fd->fd, F_SETFL, flags);
+	if (flags < 0)
+		return -1;
+
+	/* Register FD */
+	if (fd->fd > maxfd)
+		maxfd = fd->fd;
+	return list_add_tail(&fd->list, &ulogd_fds);
+}
+
+int ulogd_unregister_fd(struct ulogd_fd *fd)
+{
+	return list_del(&fd->list);
+}
+
+int ulogd_select_main()
+{
+	struct ulogd_fd *ufd;
+	fd_set readset, writeset;
+	int i;
+
+	FD_ZERO(&readset);
+	FD_ZERO(&writeset);
+
+	/* prepare read and write fdsets */
+	list_for_each_entry(&ulogd_fds, ufd, list) {
+		if (ufd->flags & ULOGD_FD_F_READ)
+			FD_SET(ufd->fd, &readset);
+
+		if (ufd->flags & UlOGD_FD_F_WRITE)
+			FD_SET(ufd->fd, &writeset);
+	}
+
+	i = select(maxfd, &readset, &writeset, NULL, NULL);
+	if (i > 0) {
+		/* call registered callback functions */
+		list_for_each_entry(&ulogd_fds, ufd, list) {
+			if (FD_ISSET(ufd->fd, &readset))
+				ret = ufd->cb(ufd->fd, UFD_FD_F_READ, 
+					      ufd->data);
+			if (FD_ISSET(ufd->fd, &writeset))
+				ret = ufd->cb(ufd->fd, UFD_FD_F_WRITE,
+					      ufd->data);
+		}
+	}
+}