[lwip-devel] lwIP 1.4.0 sockets bug? Not receiving packets on connect

[David Buzz Carlson]

Hello,

I am seeing unexpected behavior using lwIP on an STM32 platform running 
the chibiOS kernel/hal.  I am trying to open a socket to a server that 
immediately sends a handshake upon connection initiation.  The code 
looks like this:

    my_sock = lwip_socket(AF_INET, SOCK_STREAM, 0);
    opt = 2500;
    ret = lwip_setsockopt(my_sock, SOL_SOCKET, SO_RCVTIMEO, &opt, 
sizeof(int));
    ret = lwip_connect(my_sock, (struct sockaddr*)&my_conn, 
sizeof(my_conn));
    if(ret != 0) {
        lwip_close(my_sock);
        return BAD_CONN;
    }
    ret = lwip_read(my_sock, m_buf, BUF_SIZE);
    if(ret < 24) {
        chprintf((BaseChannel *)&SD1,"Did not read expected 24 bytes: 
%d\n", ret);
    }

The lwip_read function is always returning -1 even though tcpdump is 
showing that packets are being sent:

20:50:11.145020 IP comp.local.3000 > 192.168.0.89.49161: Flags [FP.], 
seq 1:70, ack 2, win 14600, length 69
20:50:17.161010 IP comp.local.3000 > 192.168.0.89.49161: Flags [FP.], 
seq 1:70, ack 2, win 14600, length 69
20:50:19.097013 IP comp.local.3000 > 192.168.0.89.49160: Flags [FP.], 
seq 1:70, ack 2, win 14600, length 69
20:50:23.221211 IP comp.local.3000 > 192.168.0.89.49162: Flags [P.], seq 
1:70, ack 2, win 14600, length 69

Just to convince myself that the server was sending the hello packet, I 
modified the code to work on my Linux box using the sockets and saw the 
hello packets exactly as I expected.

Does anybody know what would cause this, if it has been seen before, and 
how to fix it?

I very much appreciate any help,
Buzz