lib/uplinkc: add user agent

Change-Id: I6627851112823a72e4001b45d9a1b80ba76b8346

lib/uplinkc/uplink.go

@@ -45,6 +45,7 @@ func new_uplink(cfg C.UplinkConfig, tempDir *C.char, cerr **C.char) C.UplinkRef
 	libcfg.Volatile.MaxInlineSize = memory.Size(cfg.Volatile.max_inline_size)
 	libcfg.Volatile.MaxMemory = memory.Size(cfg.Volatile.max_memory)
 	libcfg.Volatile.DialTimeout = time.Duration(cfg.Volatile.dial_timeout)
+	libcfg.Volatile.UserAgent = C.GoString(cfg.Volatile.user_agent)
 
 	lib, err := uplink.NewUplink(scope.ctx, libcfg)
 	if err != nil {

lib/uplinkc/uplink_definitions.h

@@ -43,6 +43,7 @@ typedef struct UplinkConfig {
         int32_t max_inline_size;
         int32_t max_memory;
         int32_t dial_timeout;
+        char *user_agent;
     } Volatile;
 } UplinkConfig;