Fix x52d_send_command prototype

Prior to this change, the recv call was using the same buflen as that of
the send, which meant that the response would be truncated at by the
client, while the server was sending the entire message. This was
evident by running a Python client which manually called recv with the
maximum buffer size.

This change updates the prototype to take both a bufin (length of the
input buffer), and a bufout (length of the output buffer) argument,
instead of a single buflen. With this change, commands work as expected
in x52ctl.

daemon/x52ctl.c

@@ -71,7 +71,7 @@ static int send_command(int sock_fd, int argc, char **argv)
         buflen += arglen;
     }
 
-    rc = x52d_send_command(sock_fd, buffer, buflen);
+    rc = x52d_send_command(sock_fd, buffer, buflen, sizeof(buffer));
     if (rc >= 0) {
         if (write(STDOUT_FILENO, buffer, rc) < 0) {
             perror("write");

daemon/x52d_comm_client.c

@@ -51,7 +51,7 @@ int x52d_dial_command(const char *sock_path)
     return sock;
 }
 
-int x52d_send_command(int sock_fd, char *buffer, size_t buflen)
+int x52d_send_command(int sock_fd, char *buffer, size_t bufin, size_t bufout)
 {
     int rc;
 
@@ -60,7 +60,7 @@ int x52d_send_command(int sock_fd, char *buffer, size_t buflen)
          * Unix sockets should have sufficient capacity to send the full
          * datagram in a single message. Assume that is the case.
          */
-        rc = send(sock_fd, buffer, buflen, 0);
+        rc = send(sock_fd, buffer, bufin, 0);
         if (rc < 0) {
             // Error
             if (errno == EINTR) {
@@ -77,7 +77,7 @@ int x52d_send_command(int sock_fd, char *buffer, size_t buflen)
 
     /* Wait till we get a response */
     for (;;) {
-        rc = recv(sock_fd, buffer, buflen, 0);
+        rc = recv(sock_fd, buffer, bufout, 0);
         if (rc < 0) {
             // Error
             if (errno == EINTR) {

daemon/x52dcomm.h

@@ -75,12 +75,13 @@ int x52d_dial_command(const char *sock_path);
  *                          parameters. This is also used to save the returned
  *                          response.
  *
- * @param[in]       buflen  Length of the buffer to hold the returned response.
+ * @param[in]       bufin   Length of the command in the input buffer
+ * @param[in]       bufout  Maximum length of the response
  *
  * @returns number of bytes returned from the server
  * @returns -1 on an error condition, and \c errno is set accordingly.
  */
-int x52d_send_command(int sock_fd, char *buffer, size_t buflen);
+int x52d_send_command(int sock_fd, char *buffer, size_t bufin, size_t bufout);
 
 /** @} */
 #ifdef __cplusplus