statd: share the date-and-time formatter

The mDNS neighbor code has a private formatter for YANG date-and-time
strings.  More operational leaves need the same encoding, so give it a
home in shared.c and let callers pass the time to format.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

Author: troglobit

src/statd/avahi.c

@@ -36,6 +36,7 @@
 #include <srx/common.h>
 
 #include "avahi.h"
+#include "shared.h"
 
 /* Complete the opaque avahi types declared in avahi-common/watch.h */
 struct AvahiWatch {
@@ -336,15 +337,6 @@ static void free_all(struct mdns_ctx *ctx)
 
 #define XPATH_BASE "/infix-services:mdns/neighbors"
 
-static void format_timestamp(char *buf, size_t sz)
-{
-	struct tm tm;
-	time_t now = time(NULL);
-
-	gmtime_r(&now, &tm);
-	strftime(buf, sz, "%Y-%m-%dT%H:%M:%S+00:00", &tm);
-}
-
 static int sr_setstr(sr_session_ctx_t *ses, const char *xpath, const char *val)
 {
 	int err = sr_set_item_str(ses, xpath, val, NULL, 0);
@@ -449,7 +441,7 @@ static void ds_push_resolver(struct mdns_ctx *ctx, struct avahi_service *svc,
 	}
 
 	/* last-seen */
-	format_timestamp(ts, sizeof(ts));
+	format_timestamp(time(NULL), ts, sizeof(ts));
 	snprintf(xpath, sizeof(xpath),
 		 XPATH_BASE "/neighbor[hostname='%s']/last-seen", svc->hostname);
 	err = err ?: sr_setstr(ctx->sr_ses, xpath, ts);

src/statd/shared.c

@@ -2,6 +2,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <time.h>
 #include <jansson.h>
 #include <net/if.h>
 #include <libite/lite.h>
@@ -76,3 +77,12 @@ int ip_link_check_group(const char *ifname, const char *group)
 
 	return 0;
 }
+
+/* YANG date-and-time, always in UTC */
+void format_timestamp(time_t when, char *buf, size_t sz)
+{
+	struct tm tm;
+
+	gmtime_r(&when, &tm);
+	strftime(buf, sz, "%Y-%m-%dT%H:%M:%S+00:00", &tm);
+}

src/statd/shared.h

@@ -3,9 +3,12 @@
 #ifndef STATD_SHARED_H_
 #define STATD_SHARED_H_
 
+#include <stddef.h>
+#include <time.h>
 #include <jansson.h>
 
 json_t *json_get_output(const char *cmd);
 int ip_link_check_group(const char *ifname, const char *group);
+void format_timestamp(time_t when, char *buf, size_t sz);
 
 #endif