How to send data to all TCP Clients from TCP Server?

1

Hi all,

I’ve created a TCP Server inside Q2687 series module and it works fine. I also developed a desktop Client App to connect to the Server. I can connect to the Server with multiple Celient App at the same time. For some reason, I need to send data to all “connected TCP Clients” from the Server but I could not find an API or command for this. Is there any way to do this? (This is the main problem, if there is a way to do it, I won’t use the below method to solve the problem.)

So, I tried to solve the problem with my custom way. There should be used a linked list structure because of automatic list management advantages (add, remove, etc.). I decided to use the list API of Open AT Framework (wm_lst_t) to store TCP Clients’ ID’s to send them data manually. When a Client connect to the Server, I am adding the Client ID to list as follows;

position = wm_lstAddItem ( ListPtr, ev->channel ); //ev->channel gives me an ID like “0x180ce034”

And, when a Client disconnected (by the event WIP_CEV_PEER_CLOSE) or got an Error (by the event WIP_CEV_ERROR), I am deleting the Client from the list as follows;

clientCount = wm_lstDeleteItem ( ListPtr, wm_lstFindItem ( ListPtr, ev->channel ) );

From the above code line, the API wm_lstFindItem should find and give me the ID of current Client that need to be deleted from the list. It doesn’t work :interrobang: It always give 0 as index. (This is my second problem)

Any idea that you give me to solve one of the two problems would be appreciated.

Thanks in advance.

MÇ.

2

Hi all,

Does anyone have idea? Actually, this is a very common issue and there should be an easy way for this? :frowning_face:

MÇ.

3

Hi,

I don’t know why but I could not use the list API of OpenAT, it gives me error and resetting my modem each time when a client disconnected from the server so I solved the problem with my custom linked list. I am posting the solution below for those people who got similar problem for the future :slight_smile:

In the global variable section:

typedef struct node {
wip_channel_t val;
struct node * next;
} node_t;

node_t *head = NULL;

To Add Client to the Linked List Method:

void AddClientToList ( node_t * h, wip_channel_t v )
{
node_t *current = h;

while (current->next != NULL)
    current = current->next;

current->next = malloc(sizeof(node_t));
current->next->val = v;
current->next->next = NULL;

}

To Remove Client from the Linked List Method:

node_t * RemoveClientFromList ( node_t *h, wip_channel_t v )
{
node_t *temp = NULL;
node_t *current = h;

if (h->val == v)
{
	temp = h;
	h = h->next;
	free(temp);
	return h;
}

while (current->next != NULL && current->next->val != v)
	current = current->next;

if (current->next == NULL)
	return h;

temp = current->next;
current->next = current->next->next;
free(temp);
return h;

}

To Show Connected Clients into the Linked List:

void ShowConnectedClients ( node_t *h )
{
u8 i = 1;
node_t *current = h;

while (current != NULL)
{
if ( isDebug )
TRACE ( ( NORMAL_TRACE_LEVEL, “Client %d: 0x%x.”, i, current->val ) );

  current = current->next;
  i++;

}
}

Into the WIP_CEV_OPEN event of TCP server (when a TCP Client Connected to the Server):

if (clientCount == 0)
{
head = malloc ( sizeof ( node_t ));
head->val = ev->channel;
head->next = NULL;
}
else
AddClientToList ( head, ev->channel );

ShowConnectedClients ( head );
clientCount++;

Into the WIP_CEV_ERROR and WIP_CEV_PEER_CLOSE events (When a TCP Client Disconnected from the TCP Server):

head = RemoveClientFromList ( head, ev->channel );
ShowConnectedClients ( head );

To send data to all Clients:

ascii msg[4] = “test”;
node_t *current = head;
while (current != NULL)
{
wip_write ( current->val, msg, wm_strlen ( msg ) );
current = current->next;
}

Best regards,

MÇ.