Implement daemon_send_simple and use it in the testclient.

daemons/common/daemon-shared.c

@@ -2,12 +2,15 @@
 #include <stdio.h>
 #include <malloc.h>
 #include <string.h>
+#include "daemon-shared.h"
 
 /*
  * Read a single message from a (socket) filedescriptor. Messages are delimited
  * by blank lines. This call will block until all of a message is received. The
  * memory will be allocated from heap. Upon error, all memory is freed and the
  * buffer pointer is set to NULL.
+ *
+ * See also write_buffer about blocking (read_buffer has identical behaviour).
  */
 int read_buffer(int fd, char **buffer) {
 	int bytes = 0;
@@ -66,3 +69,43 @@ int write_buffer(int fd, char *buffer, int length) {
 	}
 	return 0;
 }
+
+char *format_buffer(char *id, va_list ap)
+{
+	char *buffer, *old;
+	char *next;
+	char *format;
+
+	dm_asprintf(&buffer, "request = \"%s\"\n", id);
+	if (!buffer) goto fail;
+
+	while (next = va_arg(ap, char *)) {
+		old = buffer;
+		if (strstr(next, "%d") || strstr(next, "%s")) {
+			dm_asprintf(&format, "%%s%s\n", next);
+			if (!format) goto fail;
+
+			if (strstr(format, "%d"))
+				dm_asprintf(&buffer, format, buffer, va_arg(ap, int));
+			else
+				dm_asprintf(&buffer, format, buffer, va_arg(ap, char *));
+
+			dm_free(format);
+			dm_free(old);
+			if (!buffer) goto fail;
+		} else {
+			dm_asprintf(&buffer, "%s%s", buffer, next);
+			dm_free(old);
+			if (!buffer) goto fail;
+		}
+	}
+
+	old = buffer;
+	dm_asprintf(&buffer, "%s\n", buffer);
+	dm_free(old);
+
+	return buffer;
+fail:
+	dm_free(buffer);
+	return NULL;
+}

daemons/common/daemon-shared.h

@@ -1,2 +1,6 @@
+#include <stdarg.h>
+#include <libdevmapper.h>
+
 int read_buffer(int fd, char **buffer);
 int write_buffer(int fd, char *buffer, int length);
+char *format_buffer(char *id, va_list ap);

daemons/lvmetad/lvmetad-core.c

@@ -7,7 +7,7 @@ typedef struct {
 static response handler(daemon_state s, client_handle h, request r)
 {
 	response res;
-	fprintf(stderr, "handling client request: %s\n", r.buffer);
+	fprintf(stderr, "---- server obtained:\n%s\n----------------------\n", r.buffer);
 	res.error = 1;
 	res.buffer = strdup("hey hey.\n\n");
 	return res;

daemons/lvmetad/testclient.c

@@ -2,10 +2,9 @@
 
 int main() {
 	daemon_handle h = lvmetad_open();
-	daemon_request rq = { .buffer= "hello worldn\n" };
 	int i;
 	for (i = 0; i < 5; ++i ) {
-		daemon_reply reply = daemon_send(h, rq);
+		daemon_reply reply = daemon_send_simple(h, "hello world", "param = %d", 3, NULL);
 		fprintf(stderr, "daemon says: %s\n", reply.buffer);
 	}
 	daemon_close(h);