MDP ping getting closer: ping loop showing server-returned error

messages now works.  Server currently reports error when trying to
send MDP_TX frames (since it is not yet implemented), which the
client successfully displays. Onto making the server handle the
MDP_TX frames.

commandline.c

@@ -387,12 +387,20 @@ int app_mdp_ping(int argc,char **argv,struct command_line_option *o)
   unsigned int firstSeq=random();
   unsigned int sequence_number=firstSeq;
 
+  /* Get SID that we want to ping */
+  int i;
+  unsigned char ping_sid[SID_SIZE];
+  if (strcasecmp(sid,"broadcast")) {
+    stowSid(ping_sid,0,sid);
+  } else {
+    for(i=0;i<SID_SIZE;i++) ping_sid[i]=0xff;
+  }
+
   while(1) {
-    int i;
     /* Now send the ping packets */
     mdp.packetTypeAndFlags=MDP_TX;
     /* Set destination to broadcast */
-    for(i=0;i<SID_SIZE;i++) mdp.out.dst.sid[i]=0xff;
+    for(i=0;i<SID_SIZE;i++) mdp.out.dst.sid[i]=ping_sid[i];
     /* Set port to well known echo port (from /etc/services) */
     mdp.out.dst.port=7;
     mdp.out.payload_length=4;
@@ -417,11 +425,25 @@ int app_mdp_ping(int argc,char **argv,struct command_line_option *o)
       result = overlay_mdp_client_poll(timeout_ms);
 
       if (result>0) {
-	fprintf(stderr,"Frames ready for reception.\n");
+	int ttl=-1;
+	while (overlay_mdp_recv(&mdp,&ttl)==0) {
+	  switch(mdp.packetTypeAndFlags&MDP_TYPE_MASK) {
+	  case MDP_ERROR:
+	    fprintf(stderr,"mdpping: overlay_mdp_recv: %s (code %d)\n",
+		    mdp.error.message,mdp.error.error);
+	    break;
+	  case MDP_RX:
+	    break;
+	  default:
+	    fprintf(stderr,"mdpping: overlay_mdp_recv: Unexpected MDP frame type 0x%x\n",mdp.packetTypeAndFlags);
+	    break;
+	  }
+	}
       }
       now=overlay_gettime_ms();
       if (servalShutdown) {
 	/* XXX Report final statistics before going */
+	WHY("I should be giving you ping statistics now");
 	return 0;
       }
     }

overlay_mdp.c

@@ -254,6 +254,12 @@ int overlay_mdp_poll()
       overlay_mdp_frame *mdp=(overlay_mdp_frame *)&buffer[0];
       switch(mdp->packetTypeAndFlags&MDP_TYPE_MASK) {
       case MDP_TX: /* Send payload */
+	/* Construct MDP packet frame from overlay_mdp_frame structure
+	   (need to add return address from bindings list, and copy
+	   payload etc). */
+	WHY("Not implemented");
+	overlay_mdp_reply_error(mdp_named_socket,recvaddr_un,recvaddrlen,
+				1,"Sending MDP packets not implemented");
 	break;
       case MDP_BIND: /* Bind to port */
 	return overlay_mdp_process_bind_request(mdp_named_socket,mdp,
@@ -322,7 +328,6 @@ int overlay_mdp_dispatch(overlay_mdp_frame *mdp,int flags,int timeout_ms)
     overlay_mdp_client_done();
     return -1;
   } else {
-    WHY("packet sent");
     if (!(flags&MDP_AWAITREPLY)) {       
       return 0;
     }
@@ -341,33 +346,8 @@ int overlay_mdp_dispatch(overlay_mdp_frame *mdp,int flags,int timeout_ms)
     return -1;
   }
 
-  /* Check if reply available */
-  unsigned char replybuffer[2048];
-  fcntl(mdp_client_socket, F_SETFL, 
-	fcntl(mdp_client_socket, F_GETFL, NULL)|O_NONBLOCK); 
   int ttl=-1;
-  unsigned char recvaddrbuffer[1024];
-  struct sockaddr *recvaddr=(struct sockaddr *)recvaddrbuffer;
-  unsigned int recvaddrlen=sizeof(recvaddrbuffer);
-  struct sockaddr_un *recvaddr_un;
-  mdp->packetTypeAndFlags=0;
-  len = recvwithttl(mdp_client_socket,(unsigned char *)mdp,
-		    sizeof(overlay_mdp_frame),&ttl,recvaddr,&recvaddrlen);
-  recvaddr_un=(struct sockaddr_un *)recvaddr;
-  if (len>0) {
-    /* Make sure recvaddr matches who we sent it to */
-    if (strcmp(mdp_socket_name,recvaddr_un->sun_path)) {
-      /* Okay, reply was PROBABLY not from the server, but on OSX if the path
-	 has a symlink in it, it is resolved in the reply path, but might not
-	 be in the request path (mdp_socket_name), thus we need to stat() and
-	 compare inode numbers etc */
-      struct stat sb1,sb2;
-      if (stat(mdp_socket_name,&sb1)) return WHY("stat(mdp_socket_name) failed, so could not verify that reply came from MDP server");
-      if (stat(recvaddr_un->sun_path,&sb2)) return WHY("stat(ra->sun_path) failed, so could not verify that reply came from MDP server");
-      if ((sb1.st_ino!=sb2.st_ino)||(sb1.st_dev!=sb2.st_dev))
-	return WHY("Reply did not come from server");
-    }
-
+  if (!overlay_mdp_recv(mdp,&ttl)) {
     /* If all is well, examine result and return error code provided */
     WHY("Got a reply from server");
     if ((mdp->packetTypeAndFlags&MDP_TYPE_MASK)==MDP_ERROR)
@@ -426,10 +406,49 @@ int overlay_mdp_client_done()
 int overlay_mdp_client_poll(long long timeout_ms)
 {
   if (timeout_ms<0) timeout_ms=0;
-  printf("waiting for %lldms on client socket.\n",timeout_ms);
   struct pollfd fds[1];
   int fdcount=1;
   fds[0].fd=mdp_client_socket; fds[0].events=POLLIN;
 
   return poll(fds,fdcount,timeout_ms);
 }
+
+int overlay_mdp_recv(overlay_mdp_frame *mdp,int *ttl) 
+{
+  char mdp_socket_name[101];
+  mdp_socket_name[100]=0;
+  snprintf(mdp_socket_name,100,"%s/mdp.socket",serval_instancepath());
+
+  /* Check if reply available */
+  fcntl(mdp_client_socket, F_SETFL, 
+	fcntl(mdp_client_socket, F_GETFL, NULL)|O_NONBLOCK); 
+  unsigned char recvaddrbuffer[1024];
+  struct sockaddr *recvaddr=(struct sockaddr *)recvaddrbuffer;
+  unsigned int recvaddrlen=sizeof(recvaddrbuffer);
+  struct sockaddr_un *recvaddr_un;
+  mdp->packetTypeAndFlags=0;
+  int len = recvwithttl(mdp_client_socket,(unsigned char *)mdp,
+		    sizeof(overlay_mdp_frame),ttl,recvaddr,&recvaddrlen);
+  recvaddr_un=(struct sockaddr_un *)recvaddr;
+  if (len>0) {
+    /* Make sure recvaddr matches who we sent it to */
+    /* Null terminate recvaddr->sun_path as required */
+    recvaddr_un->sun_path[recvaddr_un->sun_len-sizeof(recvaddr_un->sun_len)-sizeof(recvaddr_un->sun_family)]=0;
+    if (strcmp(mdp_socket_name,recvaddr_un->sun_path)) {
+      /* Okay, reply was PROBABLY not from the server, but on OSX if the path
+	 has a symlink in it, it is resolved in the reply path, but might not
+	 be in the request path (mdp_socket_name), thus we need to stat() and
+	 compare inode numbers etc */
+      struct stat sb1,sb2;
+      if (stat(mdp_socket_name,&sb1)) return WHY("stat(mdp_socket_name) failed, so could not verify that reply came from MDP server");
+      if (stat(recvaddr_un->sun_path,&sb2)) return WHY("stat(ra->sun_path) failed, so could not verify that reply came from MDP server");
+      if ((sb1.st_ino!=sb2.st_ino)||(sb1.st_dev!=sb2.st_dev))
+	return WHY("Reply did not come from server");
+    }
+    /* Valid packet received */
+    return 0;
+  } else 
+    /* no packet received */
+    return -1;
+
+}

serval.h

@@ -1041,4 +1041,6 @@ int setVerbosity(char *optarg);
 int overlay_mdp_client_init();
 int overlay_mdp_client_done();
 int overlay_mdp_client_poll(long long timeout_ms);
+int overlay_mdp_recv(overlay_mdp_frame *mdp,int *ttl);
 extern int mdp_client_socket;
+