[Cluster-devel] [PATCH v2 3/3] dlm: allow binding to all network interfaces

[David Windsor <dwindsor@redhat.com>]

Currently, in the kernel, DLM only is able to bind its
listen socket to a single network interface.  To support
more robust network configurations, DLM should be able
to bind to all network interfaces.

This patch adds a configfs node to enable/disable binding
to all network interfaces.  When 1 is written to this
configfs node, the DLM listen socket will bind to all network
interfaces.  When 0 is written to the node, DLM will bind
only to its current local network interface.

Signed-off-by: David Windsor <dwindsor@redhat.com>
---
 fs/dlm/config.c   | 21 +++++++++++++++++++++
 fs/dlm/config.h   |  3 ++-
 fs/dlm/lowcomms.c | 19 ++++++++++++++++++-
 3 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/fs/dlm/config.c b/fs/dlm/config.c
index 96db7b1346f9..16b83d61b060 100644
--- a/fs/dlm/config.c
+++ b/fs/dlm/config.c
@@ -29,6 +29,7 @@
  * /config/dlm/<cluster>/spaces/<space>/nodes/<node>/weight
  * /config/dlm/<cluster>/comms/<comm>/nodeid
  * /config/dlm/<cluster>/comms/<comm>/local
+ * /config/dlm/<cluster>/comms/<comm>/bind_all
  * /config/dlm/<cluster>/comms/<comm>/addr      (write only)
  * /config/dlm/<cluster>/comms/<comm>/addr_list (read only)
  * /config/dlm/<cluster>/comms/<comm>/error	(write only)
@@ -39,6 +40,7 @@ static struct config_group *space_list;
 static struct config_group *comm_list;
 static struct dlm_comm *local_comm;
 static uint32_t dlm_comm_count;
+static int bind_all;
 
 struct dlm_clusters;
 struct dlm_cluster;
@@ -200,6 +202,7 @@ enum {
 	COMM_ATTR_ADDR,
 	COMM_ATTR_ADDR_LIST,
 	COMM_ATTR_ERROR,
+	COMM_ATTR_BIND_ALL,
 };
 
 enum {
@@ -681,11 +684,23 @@ static ssize_t comm_error_store(struct config_item *item, const char *buf,
 	return len;
 }
 
+static ssize_t comm_bind_all_show(struct config_item *item, char *buf)
+{
+	return sprintf(buf, "%d\n", bind_all);
+}
+
+static ssize_t comm_bind_all_store(struct config_item *item, const char *buf,
+				   size_t len)
+{
+	return kstrtoint(buf, 0, &bind_all);
+}
+
 CONFIGFS_ATTR(comm_, nodeid);
 CONFIGFS_ATTR(comm_, local);
 CONFIGFS_ATTR_WO(comm_, addr);
 CONFIGFS_ATTR_RO(comm_, addr_list);
 CONFIGFS_ATTR_WO(comm_, error);
+CONFIGFS_ATTR(comm_, bind_all);
 
 static struct configfs_attribute *comm_attrs[] = {
 	[COMM_ATTR_NODEID] = &comm_attr_nodeid,
@@ -693,6 +708,7 @@ static struct configfs_attribute *comm_attrs[] = {
 	[COMM_ATTR_ADDR] = &comm_attr_addr,
 	[COMM_ATTR_ADDR_LIST] = &comm_attr_addr_list,
 	[COMM_ATTR_ERROR] = &comm_attr_error,
+	[COMM_ATTR_BIND_ALL] = &comm_attr_bind_all,
 	NULL,
 };
 
@@ -868,6 +884,11 @@ int dlm_our_addr(struct sockaddr_storage *addr, int num)
 	return 0;
 }
 
+int dlm_bind_all(void)
+{
+	return bind_all;
+}
+
 /* Config file defaults */
 #define DEFAULT_TCP_PORT       21064
 #define DEFAULT_BUFFER_SIZE     4096
diff --git a/fs/dlm/config.h b/fs/dlm/config.h
index 6041eec886ab..e3fd8ce45874 100644
--- a/fs/dlm/config.h
+++ b/fs/dlm/config.h
@@ -21,7 +21,7 @@ struct dlm_config_node {
 	uint32_t comm_seq;
 };
 
-#define DLM_MAX_ADDR_COUNT 3
+#define DLM_MAX_ADDR_COUNT 9
 
 struct dlm_config_info {
 	int ci_tcp_port;
@@ -49,6 +49,7 @@ int dlm_config_nodes(char *lsname, struct dlm_config_node **nodes_out,
 int dlm_comm_seq(int nodeid, uint32_t *seq);
 int dlm_our_nodeid(void);
 int dlm_our_addr(struct sockaddr_storage *addr, int num);
+int dlm_bind_all(void);
 
 #endif				/* __CONFIG_DOT_H__ */
 
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index be0e134d4fc4..60ae7c53a8a1 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -1394,6 +1394,9 @@ static int sctp_listen_for_all(void)
 static int tcp_listen_for_all(void)
 {
 	struct socket *sock = NULL;
+	struct sockaddr_in *sin4;
+	struct sockaddr_in6 *sin6;
+	struct sockaddr_storage sas, laddr;
 	struct connection *con = nodeid2con(0, GFP_NOFS);
 	int result = -EINVAL;
 
@@ -1402,7 +1405,21 @@ static int tcp_listen_for_all(void)
 
 	log_print("Using TCP for communications");
 
-	sock = tcp_create_listen_sock(con, dlm_local_addr[dlm_local_idx]);
+	memcpy(&sas, dlm_local_addr[dlm_local_idx], sizeof(sas));
+	memcpy(&laddr, dlm_local_addr[dlm_local_idx], sizeof(laddr));
+	if (dlm_bind_all()) {
+		if (sas.ss_family == AF_INET) {
+			sin4 = (struct sockaddr_in *) &sas;
+			sin4->sin_addr.s_addr = htonl(INADDR_ANY);
+			memcpy(&laddr, sin4, sizeof(laddr));
+		} else {
+			sin6 = (struct sockaddr_in6 *) &sas;
+			sin6->sin6_addr = in6addr_any;
+			memcpy(&laddr, sin6, sizeof(laddr));
+		}
+	}
+
+	sock = tcp_create_listen_sock(con, &laddr);
 	if (sock) {
 		add_sock(sock, con);
 		result = 0;
-- 
2.20.1