libcephfs_proxy: add negotiation structures

Signed-off-by: Xavi Hernandez <xhernandez@gmail.com>

diff --git a/src/libcephfs_proxy/proxy.h b/src/libcephfs_proxy/proxy.h
index cfb69072f199f26ca384d7af8bc791dc5e6e134f..239cd5d1cb542ca3e3ecfda0e2140fe7a8753ff3 100644 (file)
--- a/src/libcephfs_proxy/proxy.h
+++ b/src/libcephfs_proxy/proxy.h
@@ -45,6 +45,9 @@ typedef struct _proxy_manager proxy_manager_t;
 struct _proxy_link;
 typedef struct _proxy_link proxy_link_t;
 
+struct _proxy_link_negotiate;
+typedef struct _proxy_link_negotiate proxy_link_negotiate_t;
+
 typedef int32_t (*proxy_output_write_t)(proxy_output_t *);
 typedef int32_t (*proxy_output_full_t)(proxy_output_t *);
 

diff --git a/src/libcephfs_proxy/proxy_link.h b/src/libcephfs_proxy/proxy_link.h
index ae24b2ff931294ff419eac0a0c44749f3b663ff4..09fa3be673462c2914490e2524c49687c09225ca 100644 (file)
--- a/src/libcephfs_proxy/proxy_link.h
+++ b/src/libcephfs_proxy/proxy_link.h
@@ -9,6 +9,46 @@
 
 #define PROXY_LINK_DISCONNECTED { NULL, -1 }
 
+/* To define newer versions of the negotiate structure, look for comments
+ * starting with "NEG_VERSION" and do the appropriate changes in each place. */
+
+/* NEG_VERSION: Update this value to the latest implemented version. */
+#define PROXY_LINK_NEGOTIATE_VERSION 1
+
+/* Version 0 structure will be used to handle legacy clients that don't support
+ * negotiation. */
+typedef struct _proxy_link_negotiate_v0 {
+       /* Size of the entire structure. Don't use sizeof() to compute it, use
+        * NEG_VERSION_SIZE() to avoid alignement issues. */
+       uint16_t size;
+
+       /* Version of the negotiation structure. */
+       uint16_t version;
+
+       /* Minimum version that the peer needs to support to proceed. */
+       uint16_t min_version;
+
+       /* Reserved. Must be 0. */
+       uint16_t flags;
+} proxy_link_negotiate_v0_t;
+
+typedef struct _proxy_link_negotiate_v1 {
+       uint32_t supported;
+       uint32_t required;
+       uint32_t enabled;
+} proxy_link_negotiate_v1_t;
+
+/* NEG_VERSION: Add typedefs for new negotiate extensions above this comment. */
+
+struct _proxy_link_negotiate {
+       proxy_link_negotiate_v0_t v0;
+       proxy_link_negotiate_v1_t v1;
+
+       /* NEG_VERSION: Add newly defined typedefs above this comment. */
+};
+
+typedef int32_t (*proxy_link_negotiate_cbk_t)(proxy_link_negotiate_t *);
+
 struct _proxy_link {
        proxy_link_stop_t stop;
        int32_t sd;
@@ -27,6 +67,11 @@ typedef struct _proxy_link_ans {
        uint32_t data_len;
 } proxy_link_ans_t;
 
+#define NEG_VERSION_SIZE_1(_ver) \
+       (offset_of(proxy_link_negotiate_t, v##_ver) + \
+        sizeof(proxy_link_negotiate_v##_ver##_t))
+#define NEG_VERSION_SIZE(_ver) NEG_VERSION_SIZE_1(_ver)
+
 static inline bool proxy_link_is_connected(proxy_link_t *link)
 {
        return link->sd >= 0;