libknet: export function to allow dst cache update on link removal

Signed-off-by: Fabio M. Di Nitto <fdinitto@redhat.com>

TODO

@@ -26,8 +26,6 @@ Look into link status changes notification (maybe a signal to a thread? or write
 
 * add priority/weight to link config struct
 
-we might need to update the cache on link removal... 
-
 ring:
 
 * support 8 listener per node.

kronosnetd/vty_cli_cmds.c

@@ -692,6 +692,8 @@ static int knet_cmd_no_link(struct knet_vty *vty)
 	}
 
 	host->link[j].configured = 0;
+	if (knet_host_dst_cache_update(knet_iface->cfg_ring.knet_h, host->node_id))
+		knet_vty_write(vty, "Error: unable to update switching cache%s", telnet_newline);
 
 	return 0;
 }

libknet/handle.c

@@ -456,7 +456,7 @@ static void _handle_recv_from_links(knet_handle_t knet_h, int sockfd)
 try_again:
 				if (write(knet_h->pipefd[1], &src_host->node_id,
 					  sizeof(src_host->node_id)) != sizeof(src_host->node_id)) {
-					if (write_retry < 10) {
+					if ((write_retry < 10) && ((errno = EAGAIN) || (errno = EWOULDBLOCK))) {
 						write_retry++;
 						goto try_again;
 					} /* define what to do if we can't add a link */
@@ -566,7 +566,7 @@ static void _handle_check_each(knet_handle_t knet_h, struct knet_host *dst_host,
 			dst_link->connected = 0;
 try_again:
 			if (write(knet_h->pipefd[1], &dst_host->node_id, sizeof(dst_host->node_id)) != sizeof(dst_host->node_id)) {
-				if (write_retry < 10) {
+				if ((write_retry < 10) && ((errno = EAGAIN) || (errno = EWOULDBLOCK))) {
 					write_retry++;
 					goto try_again;
 				} /* define what to do if we can't deactivate a link */

libknet/host.c

@@ -4,6 +4,7 @@
 #include <string.h>
 #include <errno.h>
 #include <pthread.h>
+#include <unistd.h>
 
 #include "libknet-private.h"
 
@@ -149,6 +150,22 @@ int knet_host_remove(knet_handle_t knet_h, uint16_t node_id)
 	return ret;
 }
 
+int knet_host_dst_cache_update(knet_handle_t knet_h, uint16_t node_id)
+{
+	int write_retry = 0;
+
+try_again:
+	if (write(knet_h->pipefd[1], &node_id, sizeof(node_id)) != sizeof(node_id)) {
+		if ((write_retry < 10) && ((errno = EAGAIN) || (errno = EWOULDBLOCK))) {
+			write_retry++;
+			goto try_again;
+		} else {
+			return -1;
+		}
+	}
+	return 0;
+}
+
 /* bcast = 0 -> unicast packet | 1 -> broadcast|mcast */
 
 /* make this bcast/ucast aware */

libknet/libknet.h

@@ -145,6 +145,7 @@ int knet_host_acquire(knet_handle_t knet_h, struct knet_host **host);
 int knet_host_get(knet_handle_t knet_h, uint16_t node_id, struct knet_host **host);
 int knet_host_release(knet_handle_t knet_h, struct knet_host **host);
 int knet_host_remove(knet_handle_t knet_h, uint16_t node_id);
+int knet_host_dst_cache_update(knet_handle_t knet_h, uint16_t node_id);
 
 void knet_link_timeout(struct knet_link *lnk, time_t interval, time_t timeout, int precision);