UDP Send bug ...

[axwfae]

#97
#181

I'm sorry, please forgive my broken English, I was using google translation!

I was doing UDP tests, we found a problem simply is not going to update ethercard sendudp () function, specify the UDP server ip mac address!

Cause is supposed to send UDP server packets, sent into the wrong mac address.

1. Use the dhcp, mac address that will become 00: 00: 00: 00: 00: 00, if there is too dns queries or other operations before it will become a mac address of the last operation.
2. Use static ip, but only when staticSetup (myip), mac address the issue at this time becomes 00: 00: 00: 00: 00: 00
3. When using static ip, use staticSetup (myip, gwip, dnsip, netmask), mac address will become GWIP or DNSIP mac address

So my current solution is to use mode 3, the UDP server's ip settings in gwip, dnsip, so that you can on a normal pc received ethercard udp packets sent over it!

A recommendation can be added manually ipLookup function (similar dnslookup) to the user himself through this function to call to update arp hisip and its corresponding mac address in tcp / ip in!

Remarks:
You can view tcpip.cpp the EtherCard :: udpPrepare (), doing if (is_lan (myip, dip)) is judged, because UDP in LAN, it will execute setMACandIPs (destmacaddr, dip);

At this dip is udp server's ip, udp server but not destmacaddr mac address, will cause such an error occurs!

If users have ipLookup (), you can do this in some action before, to manually update the look destmacaddr to correct udp server mac address, such a mistake will not happen!

========= The following is a description of Chinese ========= 下面是中文的说明

抱歉请原谅我的破英文，我是使用 google 翻译的！

我在做 UDP 测试时，发现了一个问题，简单的说就是 ethercard 不会去更新 sendudp() 函数中，指定的 UDP server ip 的 mac 地址！

导致原本要发给 UDP server 的封包，变成发给了错误的 mac 地址。

1. 使用 dhcp , 发出的 mac 地址会 变成 00:00:00:00:00:00， 若是之前有查詢過 dns 或其他操作，就會變成最後一個操作的 mac 地址。
2. 使用 static ip , 但是只用 staticSetup(myip) 时，此时发出的 mac 地址会变成 00:00:00:00:00:00

3.使用 static ip ，使用 staticSetup(myip, gwip, dnsip, netmask) 时， mac 地址会变成 GWIP 或 DNSIP 的 mac 地址

所以我目前的解决方案是使用 3 的方式，把 UDP server 的 ip 设置在 gwip , dnsip ，这样就可以正常的在 pc 上接收到 ethercard 发送过来的 udp 封包了！

建议可以在 tcp/ip 中加一个手动 ipLookup 函数 (类似 dnslookup) 给使用者自已透过这一个函数，来调用 arp 去更新 hisip 和其对应的 mac 地址！

备注：
你可以查看 tcpip.cpp 中的 EtherCard::udpPrepare() ， 在做 if(is_lan(myip,dip)) 判断时，因为 UDP 是在 LAN ，所以会执行 setMACandIPs(destmacaddr, dip);

此时 dip 是 udp server 的 ip ，但是 destmacaddr 并不是 udp server 的 mac 地址，才会导致这样的错误发生！

若是有 ipLookup() 时，就可以在做这一些动作前，手动去更新一下 destmacaddr 到正确的 udp server 的 mac 地址，就不会发生这样的错误了！

[axwfae]

UDP SERVER IP : 192.168.123.150 MAC:00:0E:7F:A8:C9:F1
GWIP : 192.168.123.1 MAC: F4:CE:38:A5:CE:34
DM9051 : 192.168.123.170 OR DHCP MAC:74:69:69:2D:30:31

TEST_CASE_1 : USE DHCP
`
#include <dm9051.h>
#include <enc28j60.h>
#include <EtherCard.h>
#include <net.h>

static byte mymac[] = {0x74,0x69,0x69,0x2D,0x30,0x31};
byte Ethernet::buffer[600];

#define DM9051_DHCP
#ifndef DM9051_DHCP
static byte fixmyip[] = {192,168,123,170};
static byte fixgwip[] = {192,168,123,1};
static byte fixdnsip[] = {192,168,123,1};
static byte fixnetmask[] = {255,255,255,0};
#endif

//callback that prints received packets to the serial port
void udpSerialPrint(word dport, byte ip[4], word sport, const char *data, word len) {
Serial.println(dport);
Serial.print(ip[0],DEC);Serial.print(".");
Serial.print(ip[1],DEC);Serial.print(".");
Serial.print(ip[2],DEC);Serial.print(".");
Serial.println(ip[3],DEC);
Serial.println(sport);
Serial.println(data);
Serial.println(len);

{
char msg[] = {"Hello World"};
uint8_t pc_ip[] = {192,168,123,150};
// ether.parseIp(pc_ip, "192.168.123.150");

ether.sendUdp(msg, sizeof msg, 1337 , pc_ip, 1024);
Serial.println("UDP Sent !!");
}

}

void setup () {

Serial.begin(57600);
Serial.println("Onenet IOT Demo");

pinMode(9, OUTPUT);
digitalWrite(9, LOW);
delay(2);
digitalWrite(9, HIGH);
delay(2);

if (!ether.begin(sizeof Ethernet::buffer, mymac))
Serial.println( "Failed to access Ethernet controller");
else
Serial.println("Ethernet controller initialized");

#ifdef DM9051_DHCP
if (!ether.dhcpSetup())
Serial.println("Failed to get configuration from DHCP");
else
Serial.println("DHCP configuration done");
#else
ether.staticSetup(fixmyip,fixgwip,fixdnsip,fixnetmask);
#endif

ether.printIp("IP Address:\t", ether.myip);
ether.printIp("Netmask:\t", ether.netmask);
ether.printIp("Gateway:\t", ether.gwip);
ether.printIp("DNS Address :\t", ether.dnsip);

ether.udpServerListenOnPort(&udpSerialPrint, 1337);

}

void loop() {
word len = ether.packetReceive();
word pos = ether.packetLoop(len);
}

`

com port output

`
Onenet IOT Demo
Ethernet controller initialized
:
:
:

DHCP configuration done
IP Address: 192.168.123.162
Netmask: 255.255.255.0
Gateway: 192.168.123.1
DNS Address : 8.8.8.8

:
:
:

DM9051_packetSend_42_:
0 E 7F A8 9C F1 74 69 69 2D 30 31 8 6 0 1 8 0 6 4 0 2 74 69 69 2D 30 31 C0 A8 7B A2 0 E 7F A8 9C F1 C0 A8 7B 96
DM9051_packetReceive_60_:
74 69 69 2D 30 31 0 E 7F A8 9C F1 8 0 45 0 0 20 C9 61 0 0 80 11 F8 E1 C0 A8 7B 96 C0 A8 7B A2 4 0 5 39 0 C 19 AD 31 32 33 34 0 0 0 0 0 0 0 0 0 0 0 0 0 0
1337
192.168.123.150
1024
1234
4
DM9051_packetSend_54_:
0 0 0 0 0 0 74 69 69 2D 30 31 8 0 45 0 0 28 0 0 40 0 40 11 C2 3B C0 A8 7B A2 C0 A8 7B 96 5 39 4 0 0 14 2C 35 48 65 6C 6C 6F 20 57 6F 72 6C 64 0
UDP Sent !!

`

mac address is error :

DM9051_packetSend_54_:
0 0 0 0 0 0

[axwfae]

TEST_CASE_2:USE staticSetup(myip)

`
:
:

//#define DM9051_DHCP
#ifndef DM9051_DHCP
static byte fixmyip[] = {192,168,123,170};
static byte fixgwip[] = {192,168,123,1};
static byte fixdnsip[] = {192,168,123,1};
static byte fixnetmask[] = {255,255,255,0};
#endif

:
:

#ifdef DM9051_DHCP
if (!ether.dhcpSetup())
Serial.println("Failed to get configuration from DHCP");
else
Serial.println("DHCP configuration done");
#else
// ether.staticSetup(fixmyip,fixgwip,fixdnsip,fixnetmask);
ether.staticSetup(fixmyip);
#endif
:
:
`

com port output

`
Onenet IOT Demo
Ethernet controller initialized
IP Address: 192.168.123.170
Netmask: 0.0.0.0
Gateway: 0.0.0.0
DNS Address : 0.0.0.0
:
:
DM9051_packetReceive_60_:
74 69 69 2D 30 31 0 E 7F A8 9C F1 8 0 45 0 0 20 5D F 0 0 80 11 65 2C C0 A8 7B 96 C0 A8 7B AA 4 0 5 39 0 C 19 A5 31 32 33 34 0 0 0 0 0 0 0 0 0 0 0 0 0 0
1337
192.168.123.150
1024
1234
4
DM9051_packetSend_54_:
0 0 0 0 0 0 74 69 69 2D 30 31 8 0 45 0 0 28 0 0 40 0 40 11 C2 33 C0 A8 7B AA C0 A8 7B 96 5 39 4 0 0 14 2C 2D 48 65 6C 6C 6F 20 57 6F 72 6C 64 0
UDP Sent !!

`

mac address is error :

DM9051_packetSend_54_:
0 0 0 0 0 0

[axwfae]

TEST_CASE_3:USE staticSetup(myip, gwip, dnsip, netmask)

`
:
:

//#define DM9051_DHCP
#ifndef DM9051_DHCP
static byte fixmyip[] = {192,168,123,170};
static byte fixgwip[] = {192,168,123,1};
static byte fixdnsip[] = {192,168,123,1};
static byte fixnetmask[] = {255,255,255,0};
#endif

:
:

#ifdef DM9051_DHCP
if (!ether.dhcpSetup())
Serial.println("Failed to get configuration from DHCP");
else
Serial.println("DHCP configuration done");
#else
ether.staticSetup(fixmyip,fixgwip,fixdnsip,fixnetmask);
#endif
:
:
`

com port output

nenet IOT Demo
Ethernet controller initialized
IP Address: 192.168.123.170
Netmask: 255.255.255.0
Gateway: 192.168.123.1
DNS Address : 192.168.123.1
DM9051_packetSend_42_:
FF FF FF FF FF FF 74 69 69 2D 30 31 8 6 0 1 8 0 6 4 0 1 74 69 69 2D 30 31 C0 A8 7B AA 0 0 0 0 0 0 C0 A8 7B 1
DM9051_packetSend_42_:
FF FF FF FF FF FF 74 69 69 2D 30 31 8 6 0 1 8 0 6 4 0 1 74 69 69 2D 30 31 C0 A8 7B AA 0 0 0 0 0 0 C0 A8 7B 1
DM9051_packetReceive_60_:
74 69 69 2D 30 31 F4 EC 38 A5 EC 34 8 6 0 1 8 0 6 4 0 2 F4 EC 38 A5 EC 34 C0 A8 7B 1 74 69 69 2D 30 31 C0 A8 7B AA 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DM9051_packetReceive_60_:
FF FF FF FF FF FF 0 E 7F A8 9C F1 8 6 0 1 8 0 6 4 0 1 0 E 7F A8 9C F1 C0 A8 7B 96 0 0 0 0 0 0 C0 A8 7B AA 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DM9051_packetSend_42_:
0 E 7F A8 9C F1 74 69 69 2D 30 31 8 6 0 1 8 0 6 4 0 2 74 69 69 2D 30 31 C0 A8 7B AA 0 E 7F A8 9C F1 C0 A8 7B 96
DM9051_packetReceive_60_:
74 69 69 2D 30 31 0 E 7F A8 9C F1 8 0 45 0 0 20 B4 7 0 0 80 11 E 34 C0 A8 7B 96 C0 A8 7B AA 4 0 5 39 0 C 19 A5 31 32 33 34 0 0 0 0 0 0 0 0 0 0 0 0 0 0
1337
192.168.123.150
1024
1234
4
DM9051_packetSend_54_:
F4 EC 38 A5 EC 34 74 69 69 2D 30 31 8 0 45 0 0 28 0 0 40 0 40 11 C2 33 C0 A8 7B AA C0 A8 7B 96 5 39 4 0 0 14 2C 2D 48 65 6C 6C 6F 20 57 6F 72 6C 64 0
UDP Sent !!
`

mac address is error (is GWIP OR DNSIP mac address):

DM9051_packetSend_54_:
F4 EC 38 A5 EC 34

[axwfae]

TEST_CASE_4:USE staticSetup(myip, udp_serverip, udp_serverip, netmask)

`
:
:
//#define DM9051_DHCP
#ifndef DM9051_DHCP
static byte fixmyip[] = {192,168,123,170};
static byte fixgwip[] = {192,168,123,1};
static byte fixdnsip[] = {192,168,123,1};
static byte udp_serverip[] = {192,168,123,150};
static byte fixnetmask[] = {255,255,255,0};
#endif

:
:

#ifdef DM9051_DHCP
if (!ether.dhcpSetup())
Serial.println("Failed to get configuration from DHCP");
else
Serial.println("DHCP configuration done");
#else
ether.staticSetup(fixmyip,udp_serverip,udp_serverip,fixnetmask);
#endif
:
:
`

com port output

`
Onenet IOT Demo
Ethernet controller initialized
IP Address: 192.168.123.170
Netmask: 255.255.255.0
Gateway: 192.168.123.150
DNS Address : 192.168.123.150
DM9051_packetSend_42_:
FF FF FF FF FF FF 74 69 69 2D 30 31 8 6 0 1 8 0 6 4 0 1 74 69 69 2D 30 31 C0 A8 7B AA 0 0 0 0 0 0 C0 A8 7B 96
DM9051_packetSend_42_:
FF FF FF FF FF FF 74 69 69 2D 30 31 8 6 0 1 8 0 6 4 0 1 74 69 69 2D 30 31 C0 A8 7B AA 0 0 0 0 0 0 C0 A8 7B 96
DM9051_packetReceive_60_:
74 69 69 2D 30 31 0 E 7F A8 9C F1 8 6 0 1 8 0 6 4 0 2 0 E 7F A8 9C F1 C0 A8 7B 96 74 69 69 2D 30 31 C0 A8 7B AA 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
DM9051_packetReceive_60_:
74 69 69 2D 30 31 0 E 7F A8 9C F1 8 0 45 0 0 20 22 68 0 0 80 11 9F D3 C0 A8 7B 96 C0 A8 7B AA 4 0 5 39 0 C 19 A5 31 32 33 34 0 0 0 0 0 0 0 0 0 0 0 0 0 0
1337
192.168.123.150
1024
1234
4
DM9051_packetSend_54_:
0 E 7F A8 9C F1 74 69 69 2D 30 31 8 0 45 0 0 28 0 0 40 0 40 11 C2 33 C0 A8 7B AA C0 A8 7B 96 5 39 4 0 0 14 2C 2D 48 65 6C 6C 6F 20 57 6F 72 6C 64 0
UDP Sent !!

`

mac address is ok:

DM9051_packetSend_54_:
0 E 7F A8 9C F1

[ManfredBartz]

if the destination is on the local subnet the library must make an ARP request for the destination IP.
It doesn't.

One would have to add another state machine to implement this. Doing this properly with timeouts and error handling would be a considerable effort.

A work-around is to send to the local subnet's broadcast address.