ndisc: improve debug log message

src/libsystemd-network/ndisc-internal.h

@@ -38,3 +38,6 @@ struct sd_ndisc {
 
 #define log_ndisc_errno(error, fmt, ...) log_internal(LOG_DEBUG, error, __FILE__, __LINE__, __func__, "NDISC: " fmt, ##__VA_ARGS__)
 #define log_ndisc(fmt, ...) log_ndisc_errno(0, fmt, ##__VA_ARGS__)
+
+const char* ndisc_event_to_string(sd_ndisc_event e) _const_;
+sd_ndisc_event ndisc_event_from_string(const char *s) _pure_;

src/libsystemd-network/sd-ndisc.c

@@ -16,19 +16,30 @@
 #include "ndisc-router.h"
 #include "random-util.h"
 #include "socket-util.h"
+#include "string-table.h"
 #include "string-util.h"
 #include "util.h"
 
 #define NDISC_TIMEOUT_NO_RA_USEC (NDISC_ROUTER_SOLICITATION_INTERVAL * NDISC_MAX_ROUTER_SOLICITATIONS)
 
+static const char * const ndisc_event_table[_SD_NDISC_EVENT_MAX] = {
+        [SD_NDISC_EVENT_TIMEOUT] = "timeout",
+        [SD_NDISC_EVENT_ROUTER] = "router",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(ndisc_event, sd_ndisc_event);
+
 static void ndisc_callback(sd_ndisc *ndisc, sd_ndisc_event event, sd_ndisc_router *rt) {
         assert(ndisc);
+        assert(event >= 0 && event < _SD_NDISC_EVENT_MAX);
 
-        log_ndisc("Invoking callback for '%c'.", event);
 
-        if (!ndisc->callback)
+        if (!ndisc->callback) {
+                log_ndisc("Received '%s' event.", ndisc_event_to_string(event));
                 return;
+        }
 
+        log_ndisc("Invoking callback for '%s' event.", ndisc_event_to_string(event));
         ndisc->callback(ndisc, event, rt, ndisc->userdata);
 }