why winsock cannot get my UDP packet ?

[mehmet.karakaya]

Posted on December 28, 2012 at 15:01

#include ''stm32f4xx_conf.h'' 
#include ''ethernet.h'' 
#include <stdio.h> 
#include <string.h> 
//source IP 
#define S_IP1 192 
#define S_IP2 168 
#define S_IP3 1 
#define S_IP4 100 
//dest IP 
#define D_IP1 192 
#define D_IP2 168 
#define D_IP3 1 
#define D_IP4 2 
struct
ip_eth_addr { 
uint8_t addr[4]; 
}; 
struct
mac_addr { 
uint8_t addr[6]; 
}; 
struct
ip_eth_addr s_ip = { {S_IP1, S_IP2, S_IP3, S_IP4}}; 
struct
ip_eth_addr d_ip = { {D_IP1, D_IP2, D_IP3, D_IP4}}; 
struct
mac_addr mymac = { {0x1c, 0x9a, 0x65, 0x4a, 0xd9, 0x6c} } ; 
struct
mac_addr destmac = { {0xff, 0xff, 0xff, 0xff, 0xff, 0xff} } ; 
char
ipstring [20]; 
void
* first_data_byte; 
//define ethernet II header 
struct
eth_header 
{ 
//ether frame 
uint8_t ether_dest[6]; 
//destination mac address 
uint8_t ether_src[6]; 
//source mac address 
uint16_t ether_type; 
//ether type 
//ip frame 
uint8_t vhl;
//version / IHL 
uint8_t tos;
//type of service 
uint16_t len;
//len 
uint16_t ipid; 
uint16_t ipoffset; 
uint8_t ttl; 
uint8_t proto; 
uint16_t ipchksum; 
uint16_t srcipaddr[2]; 
//26 
uint16_t destipaddr[2]; 
//udp 
uint16_t srcport; 
uint16_t destport; 
uint16_t udplen; 
uint16_t udpchksum; 
}; 
//struct eth_header frame; 
#define frame ((struct eth_header*)&uip_buf[0]) 
unsigned 
char
frame_counter; 
unsigned 
int
test_counter; 
char
test1[] = 
''TEST''
; 
unsigned 
int
data_len = 64; 
//udp data len 
void
send_UDP_frame(
void
) 
{ 
frame_counter++; 
uip_len = 
sizeof
(
struct
eth_header); 
//get struct header len = 42 
memcpy
(frame->ether_dest, &destmac, 6); 
//0xff = broadcast 
memcpy
(frame->ether_src, &mymac, 6); 
frame->ether_type = HTONS(0x0800); 
//IP following 
frame->vhl = 0x45; 
//IP4, 20byte header 
frame->tos = 0x00; 
// 
frame->len = HTONS(28 + data_len); 
frame->ipid = HTONS(frame_counter);
// 
frame->ipoffset = HTONS(0); 
frame->ttl = 0x80; 
//time to live 
frame->proto = 0x11; 
//UDP (17) 
frame->ipchksum = 0; 
//reset checksum (will be calculated and inserted later) 
memcpy
(frame->srcipaddr, &s_ip,4); 
//insert source ip 
memcpy
(frame->destipaddr,&d_ip,4); 
//insert dest ip 
//calculate IP4 header checksum 
frame->ipchksum=~uip_chksum((uint16_t*)&uip_buf[14],20); 
//20 byte header checksum 
frame->srcport = HTONS(1024); 
//source port 
frame->destport = HTONS(1023); 
//destination port 
frame->udplen = HTONS(data_len+8); 
//data len + 8 byte udp header 
tapdev_send(uip_buf,uip_len+data_len); 
} 

hello forum, I am trying to send an empty UDP packet to visual basic 6.0 winsock as you can see in attached picture wireshark ''sees'' theUDP packets howeverwinsock never go into below subroutine ( it doesnot getthe packets) what is the missing thinghere? thank you

Private
Sub
Winsock1_DataArrival(
ByVal
bytesTotal 
As
Long
) 
Text1 = bytesTotal 
Dim
strData 
As
String
Winsock1.GetData strData, vbString 
End
Sub

#udp-winsock

[Tesla DeLorean]

Posted on December 28, 2012 at 16:44

Not familiar with how it works in VB, but building an app using WinSock you need to register the application with the Windows Firewall for it to work as expected.

[dandan9]

Posted on December 28, 2012 at 19:31

The easiest way to debug your VB program is to create a second socket in VB and send data to yourself. You can either use your own IP or the loopback address 127.0.0.1; whether it will actually make it out on the wire or not depends on the stack in Windows (though I wouldn't count on it). Either way you can test your construction of listening on port 1023 and the data receive function without even leaving your PC.

Dan

[mehmet.karakaya]

Posted on April 22, 2013 at 14:00

hello forum ,

I succeeded to send ''TEST'' to PC from my STM32F4 however only with a cross cable ( directly from STM to PC ) why cant I send when I conect STM to adsl router ? has anybody a working UDP code for STM32F4 thank you

[Andrew Neil]

Posted on April 22, 2013 at 15:23

''why cant I send when I conect STM to adsl router?''

Probably because your rouer configuration does not allow it?

This might be useful:

http://www.simplecomtools.com/productcart/pc/viewPrd.asp?idproduct=6&idcategory=5

You should start by seeing if you can successfully send & receive UDP packets between 1 PCs on your network...

[Tesla DeLorean]

Posted on April 22, 2013 at 16:43

You'd want to confirm the IP/MAC addresses involved, if you have the IP for a Gateway and DNS.

I'd generally recommend the use of standard cables, and a dumb hub (ie not a switch), this reduces complication, and permits you to ''T'' connect into an active network and observe traffic.