[PATCH v6 COLO 11/15] COLO proxy: preresume, postresume and checkpoint

[Yang Hongyang <yanghy@cn.fujitsu.com>]

preresume, postresume and checkpoint

Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
---
 tools/libxl/libxl_colo.h       |  3 +++
 tools/libxl/libxl_colo_proxy.c | 57 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/tools/libxl/libxl_colo.h b/tools/libxl/libxl_colo.h
index 5983aa0..872c652 100644
--- a/tools/libxl/libxl_colo.h
+++ b/tools/libxl/libxl_colo.h
@@ -47,4 +47,7 @@ extern void libxl__colo_save_teardown(libxl__egc *egc,
 
 extern int colo_proxy_setup(libxl__colo_proxy_state *cps);
 extern void colo_proxy_teardown(libxl__colo_proxy_state *cps);
+extern void colo_proxy_preresume(libxl__colo_proxy_state *cps);
+extern void colo_proxy_postresume(libxl__colo_proxy_state *cps);
+extern int colo_proxy_checkpoint(libxl__colo_proxy_state *cps);
 #endif
diff --git a/tools/libxl/libxl_colo_proxy.c b/tools/libxl/libxl_colo_proxy.c
index 9f1243e..c8ff722 100644
--- a/tools/libxl/libxl_colo_proxy.c
+++ b/tools/libxl/libxl_colo_proxy.c
@@ -208,3 +208,60 @@ void colo_proxy_teardown(libxl__colo_proxy_state *cps)
         cps->sock_fd = -1;
     }
 }
+
+/* ========= colo-proxy: preresume, postresume and checkpoint ========== */
+
+void colo_proxy_preresume(libxl__colo_proxy_state *cps)
+{
+    colo_proxy_send(cps, NULL, 0, COLO_CHECKPOINT);
+    /* TODO: need to handle if the call fails... */
+}
+
+void colo_proxy_postresume(libxl__colo_proxy_state *cps)
+{
+    /* nothing to do... */
+}
+
+
+typedef struct colo_msg {
+    bool is_checkpoint;
+} colo_msg;
+
+/*
+do checkpoint: return 1
+error: return -1
+do not checkpoint: return 0
+*/
+int colo_proxy_checkpoint(libxl__colo_proxy_state *cps)
+{
+    uint8_t *buff;
+    int64_t size;
+    struct nlmsghdr *h;
+    struct colo_msg *m;
+    int ret = -1;
+
+    size = colo_proxy_recv(cps, &buff, MSG_DONTWAIT);
+
+    /* timeout, return no checkpoint message. */
+    if (size <= 0) {
+        return 0;
+    }
+
+    h = (struct nlmsghdr *) buff;
+
+    if (h->nlmsg_type == NLMSG_ERROR) {
+        goto out;
+    }
+
+    if (h->nlmsg_len < NLMSG_LENGTH(sizeof(*m))) {
+        goto out;
+    }
+
+    m = NLMSG_DATA(h);
+
+    ret = m->is_checkpoint ? 1 : 0;
+
+out:
+    free(buff);
+    return ret;
+}
-- 
1.9.1