treewide: deduplicate token parameter parsing

Author: f00b4r0

acarsdec.c

@@ -561,3 +561,41 @@ int main(int argc, char **argv)
 
 	exit(res);
 }
+
+/**
+ * Parse a parameter string.
+ * Parameter string formatted like "param1=foo,param2=blah,param3=42"
+ * @paramsp pointer to params string input
+ * @sp pointer to struct containing expected parameters, the #valp member will be updated for each match
+ * @np array size of #sp
+ * @return NULL if the input has been succesfully exhausted (or was NULL), pointer to first unmatched token otherwise
+ * @note Behavior matching that of strsep(): *paramsp is updated to point to next token group or NULL if EOL
+ * If an unidentified parameter is found in the string, it is returned by the function, with the '=' separator restored
+ */
+char * parse_params(char **paramsp, struct params_s *sp, const int np)
+{
+	char *param, *sep;
+	int i;
+
+	while ((param = strsep(paramsp, ","))) {
+		sep = strchr(param, '=');
+		if (!sep)
+			continue;
+
+		*sep++ = '\0';
+
+		for (i = 0; i < np; i++) {
+			if (!strcmp(sp[i].name, param)) {
+				*sp[i].valp = sep;
+				break;
+			}
+		}
+
+		if (np == i) {		// unknown param
+			*--sep = '=';	// restore key-value separator for external processing
+			return param;
+		}
+	}
+
+	return NULL;
+}

acarsdec.h

@@ -160,4 +160,11 @@ typedef struct {
 
 extern runtime_t R;
 
+struct params_s {
+	const char *const name;
+	char **valp;
+};
+
+char * parse_params(char **, struct params_s *, const int);
+
 #endif /* acarsdec_h */

fileout.c

@@ -77,22 +77,18 @@ static FILE *open_outfile(fileout_t *fout)
 // optional "rotate=" parameter followed by "none" (default), "hourly", "daily"
 fileout_t *Fileoutinit(char *params)
 {
-	char *param, *sep, *path = NULL, *rotate = NULL;
+	char *path = NULL, *rotate = NULL;
+	struct params_s filep[] = {
+		{ .name = "path", .valp = &path, },
+		{ .name = "rotate", .valp = &rotate, },
+	};
+	char *retp;
 	fileout_t *fout;
 
-	while ((param = strsep(&params, ","))) {
-		sep = strchr(param, '=');
-		if (!sep)
-			continue;
-		*sep++ = '\0';
-		if (!strcmp("path", param))
-			path = sep;
-		if (!strcmp("rotate", param))
-			rotate = sep;
-		else {
-			fprintf(stderr, ERRPFX "unknown parameter '%s'\n", param);
-			return NULL;
-		}
+	retp = parse_params(&params, filep, ARRAY_SIZE(filep));
+	if (retp) {
+		fprintf(stderr, ERRPFX "unknown parameter '%s'\n", retp);
+		return NULL;
 	}
 
 	fout = calloc(1, sizeof(*fout));

mqttout.c

@@ -35,34 +35,36 @@ mqttout_t *MQTTinit(char *params)
 	mqttout_t *mqpriv;
 	char *urls[15] = {};
 	char **url, *topic = NULL, *user = NULL, *passwd = NULL, *msgtopic = NULL;
-	char *param, *sep;
+	struct params_s mqttp[] = {
+		{ .name = "topic", .valp = &topic, },
+		{ .name = "user", .valp = &user, },
+		{ .name = "passwd", .valp = &passwd, },
+	};
+	char *retp, *sep;
 	int rc;
 	MQTTAsync_createOptions create_opts = MQTTAsync_createOptions_initializer;
 	MQTTAsync_connectOptions conn_opts = MQTTAsync_connectOptions_initializer;
 
 	url = urls;
-	while ((param = strsep(&params, ","))) {
-		sep = strchr(param, '=');
-		if (!sep)
-			continue;
-		*sep++ = '\0';
-		if (!strcmp("topic", param))
-			topic = sep;
-		else if (!strcmp("user", param))
-			user = sep;
-		else if (!strcmp("passwd", param))
-			passwd = sep;
-		else if (!strcmp("uri", param)) {
-			if (url > &urls[14])
-				fprintf(stderr, WARNPFX "too many urls provided, ignoring '%s'\n", sep);
-			else
-				*url++ = sep;
-		}
-		else {
-			fprintf(stderr, ERRPFX "unknown parameter '%s'\n", param);
-			return NULL;
+
+	do {
+		retp = parse_params(&params, mqttp, ARRAY_SIZE(mqttp));
+		if (retp) {
+			sep = strchr(retp, '=');	// guaranteed to exist due to parse_params()
+			*sep++ = '\0';
+			if (!strcmp("uri", retp)) {
+				if (url > &urls[14])
+					fprintf(stderr, WARNPFX "too many urls provided, ignoring '%s'\n", sep);
+				else
+					*url++ = sep;
+			}
+			else {
+				fprintf(stderr, ERRPFX "unknown parameter '%s'\n", retp);
+				return NULL;
+
+			}
 		}
-	}
+	} while (retp);
 
 	if (!urls[0]) {
 		fprintf(stderr, ERRPFX "no URI provided\n");

netout.c

@@ -38,26 +38,21 @@
 // params is "host=xxx,port=yyy"
 netout_t *Netoutinit(char *params)
 {
-	char *param, *sep;
 	char *addr = NULL;
 	char *port = NULL;
+	struct params_s netp[] = {
+		{ .name = "host", .valp = &addr, },
+		{ .name = "port", .valp = &port, },
+	};
+	char *retp;
 	struct addrinfo hints, *servinfo, *p;
 	int sockfd, rv;
 	netout_t *netpriv = NULL;
 
-	while ((param = strsep(&params, ","))) {
-		sep = strchr(param, '=');
-		if (!sep)
-			continue;
-		*sep++ = '\0';
-		if (!strcmp("host", param))
-			addr = sep;
-		else if (!strcmp("port", param))
-			port = sep;
-		else {
-			fprintf(stderr, ERRPFX "unknown parameter '%s'\n", param);
-			return NULL;
-		}
+	retp = parse_params(&params, netp, ARRAY_SIZE(netp));
+	if (retp) {
+		fprintf(stderr, ERRPFX "unknown parameter '%s'\n", retp);
+		return NULL;
 	}
 
 	if (!addr) {

statsd.c

@@ -49,26 +49,20 @@ static struct {
  */
 int statsd_init(char *params, const char *idstation)
 {
-	const char *host = NULL, *port = NULL;
-	char *param, *sep;
+	char *host = NULL, *port = NULL, *retp;
+	struct params_s statsdp[] = {
+		{ .name = "host", .valp = &host, },
+		{ .name = "port", .valp = &port, },
+	};
 	int sockfd;
 	struct addrinfo hints;
 	struct addrinfo *result, *rp;
 	int ret;
 
-	while ((param = strsep(&params, ","))) {
-		sep = strchr(param, '=');
-		if (!sep)
-			continue;
-		*sep++ = '\0';
-		if (!strcmp("host", param))
-			host = sep;
-		else if (!strcmp("port", param))
-			port = sep;
-		else {
-			fprintf(stderr, ERRPFX "unknown parameter '%s'\n", param);
-			return -1;
-		}
+	retp = parse_params(&params, statsdp, ARRAY_SIZE(statsdp));
+	if (retp) {
+		fprintf(stderr, ERRPFX "unknown parameter '%s'\n", retp);
+		return -1;
 	}
 
 	if (!host || !port) {
@@ -111,9 +105,9 @@ int statsd_init(char *params, const char *idstation)
 		perror("statsd");
 		goto cleanup;
 	}
-	sep = stpcpy(statsd_runtime.namespace, STATSD_NAMESPACE);
+	retp = stpcpy(statsd_runtime.namespace, STATSD_NAMESPACE);
 	if (idstation) {
-		strcpy(sep, idstation);
+		strcpy(retp, idstation);
 		statsd_runtime.namespace[ret++] = '.';
 		statsd_runtime.namespace[ret] = '\0';
 	}