daemon: make json_get_param() understand which args are compulsory.

So far only one isn't, so this saves us some checks.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

daemon/controlled_time.c

@@ -22,15 +22,18 @@ static void json_mocktime(struct command *cmd,
 	u64 prev_time, mocktime;
 	char mocktimestr[STR_MAX_CHARS(int64_t)];
 
-	json_get_params(buffer, params,
-			"mocktime", &mocktimetok,
-			NULL);
-
-	prev_time = controlled_time().ts.tv_sec;
-	if (!mocktimetok || !json_tok_u64(buffer, mocktimetok, &mocktime)) {
+	if (!json_get_params(buffer, params,
+			     "mocktime", &mocktimetok,
+			     NULL)) {
+		command_fail(cmd, "Need mocktime");
+		return;
+	}
+	if (!json_tok_u64(buffer, mocktimetok, &mocktime)) {
 		command_fail(cmd, "Need valid mocktime");
 		return;
 	}
+
+	prev_time = controlled_time().ts.tv_sec;
 	mock_time.ts.tv_sec = mocktime;
 
 	json_object_start(response, NULL);

daemon/json.c

@@ -195,7 +195,8 @@ const jsmntok_t *json_delve(const char *buffer,
 	return tok;
 }
 
-void json_get_params(const char *buffer, const jsmntok_t param[], ...)
+/* FIXME: Return false if unknown params specified, too! */
+bool json_get_params(const char *buffer, const jsmntok_t param[], ...)
 {
 	va_list ap;
 	const char *name;
@@ -213,6 +214,11 @@ void json_get_params(const char *buffer, const jsmntok_t param[], ...)
 	va_start(ap, param);
 	while ((name = va_arg(ap, const char *)) != NULL) {
 		tokptr = va_arg(ap, const jsmntok_t **);
+		bool compulsory = true;
+		if (name[0] == '?') {
+			name++;
+			compulsory = false;
+		}
 		if (param->type == JSMN_ARRAY) {
 			*tokptr = p;
 			if (p) {
@@ -229,9 +235,12 @@ void json_get_params(const char *buffer, const jsmntok_t param[], ...)
 		    && buffer[(*tokptr)->start] == 'n') {
 			*tokptr = NULL;
 		}
+		if (compulsory && !*tokptr)
+			return false;
 	}
 
 	va_end(ap);
+	return true;
 }
 
 jsmntok_t *json_parse_input(const char *input, int len, bool *valid)

daemon/json.h

@@ -38,11 +38,14 @@ bool json_tok_is_null(const char *buffer, const jsmntok_t *tok);
 /* Returns next token with same parent. */
 const jsmntok_t *json_next(const jsmntok_t *tok);
 
-/* Get the parameters (by position or name).  Followed by pairs
+/* Get the parameters (by position or name).  Followed by triples of
  * of const char *name, const jsmntok_t **ret_ptr, then NULL.
- * *ret_ptr will be set to NULL if it's a literal 'null' or not present.
+ *
+ * If name starts with '?' it is optional (and will be set to NULL
+ * if it's a literal 'null' or not present).
+ * Otherwise false is returned.
  */
-void json_get_params(const char *buffer, const jsmntok_t param[], ...);
+bool json_get_params(const char *buffer, const jsmntok_t param[], ...);
 
 /* Get top-level member. */
 const jsmntok_t *json_get_member(const char *buffer, const jsmntok_t tok[],

daemon/jsonrpc.c

@@ -154,7 +154,7 @@ static void json_getlog(struct command *cmd,
 	struct log_record *lr = cmd->dstate->log_record;
 	jsmntok_t *level;
 
-	json_get_params(buffer, params, "level", &level, NULL);
+	json_get_params(buffer, params, "?level", &level, NULL);
 
 	info.num_skipped = 0;
 
@@ -199,11 +199,9 @@ static void json_rhash(struct command *cmd,
 	jsmntok_t *secrettok;
 	struct sha256 secret;
 
-	json_get_params(buffer, params,
-			"secret", &secrettok,
-			NULL);
-
-	if (!secrettok) {
+	if (!json_get_params(buffer, params,
+			     "secret", &secrettok,
+			     NULL)) {
 		command_fail(cmd, "Need secret");
 		return;
 	}

daemon/peer.c

@@ -512,13 +512,11 @@ static void json_connect(struct command *cmd,
 	struct json_connecting *connect;
 	jsmntok_t *host, *port, *satoshis;
 
-	json_get_params(buffer, params,
-			"host", &host,
-			"port", &port,
-			"satoshis", &satoshis,
-			NULL);
-
-	if (!host || !port || !satoshis) {
+	if (!json_get_params(buffer, params,
+			     "host", &host,
+			     "port", &port,
+			     "satoshis", &satoshis,
+			     NULL)) {
 		command_fail(cmd, "Need host, port and satoshis");
 		return;
 	}
@@ -1395,14 +1393,12 @@ static void json_newhtlc(struct command *cmd,
 	unsigned int expiry;
 	struct newhtlc *newhtlc;
 
-	json_get_params(buffer, params,
-			"peerid", &peeridtok,
-			"msatoshis", &msatoshistok,
-			"expiry", &expirytok,
-			"rhash", &rhashtok,
-			NULL);
-
-	if (!peeridtok || !msatoshistok || !expirytok || !rhashtok) {
+	if (!json_get_params(buffer, params,
+			     "peerid", &peeridtok,
+			     "msatoshis", &msatoshistok,
+			     "expiry", &expirytok,
+			     "rhash", &rhashtok,
+			     NULL)) {
 		command_fail(cmd, "Need peerid, msatoshis, expiry and rhash");
 		return;
 	}
@@ -1525,12 +1521,10 @@ static void json_fulfillhtlc(struct command *cmd,
 	struct pubkey peerid;
 	struct fulfillhtlc *fulfillhtlc;
 
-	json_get_params(buffer, params,
-			"peerid", &peeridtok,
-			"r", &rtok,
-			NULL);
-
-	if (!peeridtok || !rtok) {
+	if (!json_get_params(buffer, params,
+			     "peerid", &peeridtok,
+			     "r", &rtok,
+			     NULL)) {
 		command_fail(cmd, "Need peerid and r");
 		return;
 	}
@@ -1615,12 +1609,10 @@ static void json_failhtlc(struct command *cmd,
 	struct pubkey peerid;
 	struct failhtlc *failhtlc;
 
-	json_get_params(buffer, params,
-			"peerid", &peeridtok,
-			"rhash", &rhashtok,
-			NULL);
-
-	if (!peeridtok || !rhashtok) {
+	if (!json_get_params(buffer, params,
+			     "peerid", &peeridtok,
+			     "rhash", &rhashtok,
+			     NULL)) {
 		command_fail(cmd, "Need peerid and rhash");
 		return;
 	}
@@ -1667,11 +1659,9 @@ static void json_close(struct command *cmd,
 	jsmntok_t *peeridtok;
 	struct pubkey peerid;
 
-	json_get_params(buffer, params,
-			"peerid", &peeridtok,
-			NULL);
-
-	if (!peeridtok) {
+	if (!json_get_params(buffer, params,
+			     "peerid", &peeridtok,
+			     NULL)) {
 		command_fail(cmd, "Need peerid");
 		return;
 	}