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Merge pull request #128 from Greblys/master
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Fix to make library to work in local subnet.
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@Greblys
Greblys committed Jul 15, 2014
2 parents f113f28 + b26219c commit c22c408
Showing 1 changed file with 61 additions and 14 deletions.
75 changes: 61 additions & 14 deletions tcpip.cpp
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Expand Up @@ -42,6 +42,11 @@ static const char *client_urlbuf; // Pointer to c-string path part of HTTP reque
static const char *client_urlbuf_var; // Pointer to c-string filename part of HTTP request URL
static const char *client_hoststr; // Pointer to c-string hostname of current HTTP request
static void (*icmp_cb)(uint8_t *ip); // Pointer to callback function for ICMP ECHO response handler (triggers when localhost recieves ping respnse (pong))
static uint8_t destmacaddr[6]; // storing both dns server and destination mac addresses, but at different times because both are never needed at same time.
static boolean waiting_for_dns_mac = false; //might be better to use bit flags and bitmask operations for these conditions
static boolean has_dns_mac = false;
static boolean waiting_for_dest_mac = false;
static boolean has_dest_mac = false;
static uint8_t gwmacaddr[6]; // Hardware (MAC) address of gateway router
static uint8_t waitgwmac; // Bitwise flags of gateway router status - see below for states
//Define gatweay router ARP statuses
Expand Down Expand Up @@ -97,6 +102,17 @@ static uint8_t check_ip_message_is_from(const uint8_t *ip) {
return memcmp(gPB + IP_SRC_P, ip, 4) == 0;
}

static boolean is_lan(const uint8_t source[4], const uint8_t destination[4]) {
if(source[0] == 0 || destination[0] == 0) {
return false;
}
for(int i = 0; i < 4; i++)
if((source[i] & EtherCard::netmask[i]) != (destination[i] & EtherCard::netmask[i])) {
return false;
}
return true;
}

static uint8_t eth_type_is_arp_and_my_ip(uint16_t len) {
return len >= 41 && gPB[ETH_TYPE_H_P] == ETHTYPE_ARP_H_V &&
gPB[ETH_TYPE_L_P] == ETHTYPE_ARP_L_V &&
Expand Down Expand Up @@ -285,7 +301,10 @@ void EtherCard::httpServerReply_with_flags (uint16_t dlen , uint8_t flags) {
}

void EtherCard::clientIcmpRequest(const uint8_t *destip) {
setMACandIPs(gwmacaddr, destip);
if(is_lan(EtherCard::myip, destip)) {
setMACandIPs(destmacaddr, destip);
} else
setMACandIPs(gwmacaddr, destip);
gPB[ETH_TYPE_H_P] = ETHTYPE_IP_H_V;
gPB[ETH_TYPE_L_P] = ETHTYPE_IP_L_V;
memcpy_P(gPB + IP_P,iphdr,9);
Expand All @@ -306,7 +325,10 @@ void EtherCard::clientIcmpRequest(const uint8_t *destip) {
}

void EtherCard::ntpRequest (uint8_t *ntpip,uint8_t srcport) {
setMACandIPs(gwmacaddr, ntpip);
if(is_lan(myip, ntpip)) {
setMACandIPs(destmacaddr, ntpip);
} else
setMACandIPs(gwmacaddr, ntpip);
gPB[ETH_TYPE_H_P] = ETHTYPE_IP_H_V;
gPB[ETH_TYPE_L_P] = ETHTYPE_IP_L_V;
memcpy_P(gPB + IP_P,iphdr,9);
Expand Down Expand Up @@ -339,8 +361,10 @@ uint8_t EtherCard::ntpProcessAnswer (uint32_t *time,uint8_t dstport_l) {
}

void EtherCard::udpPrepare (uint16_t sport, const uint8_t *dip, uint16_t dport) {
setMACandIPs(gwmacaddr, dip);
//!@todo Use destination MAC if on local subnet - that means checking address and performing ARP which may bloat software.
if(is_lan(myip, dip)) // this works because both dns mac and destinations mac are stored in same variable - destmacaddr
setMACandIPs(destmacaddr, dip); // at different times. The program could have separate variable for dns mac, then here should be
else // checked if dip is dns ip and separately if dip is hisip and then use correct mac.
setMACandIPs(gwmacaddr, dip);
// see http://tldp.org/HOWTO/Multicast-HOWTO-2.html
// multicast or broadcast address, https://github.com/jcw/ethercard/issues/59
if ((dip[0] & 0xF0) == 0xE0 || *((unsigned long*) dip) == 0xFFFFFFFF)
Expand Down Expand Up @@ -414,18 +438,17 @@ static void client_arp_whohas(uint8_t *ip_we_search) {
EtherCard::copyMac(gPB + ETH_ARP_SRC_MAC_P, EtherCard::mymac);
EtherCard::copyIp(gPB + ETH_ARP_DST_IP_P, ip_we_search);
EtherCard::copyIp(gPB + ETH_ARP_SRC_IP_P, EtherCard::myip);
waitgwmac |= WGW_ACCEPT_ARP_REPLY;
EtherCard::packetSend(42);
}

uint8_t EtherCard::clientWaitingGw () {
return !(waitgwmac & WGW_HAVE_GW_MAC);
}

static uint8_t client_store_gw_mac() {
if (memcmp(gPB + ETH_ARP_SRC_IP_P, EtherCard::gwip, 4) != 0)
static uint8_t client_store_mac(uint8_t *source_ip, uint8_t *mac) {
if (memcmp(gPB + ETH_ARP_SRC_IP_P, source_ip, 4) != 0)
return 0;
EtherCard::copyMac(gwmacaddr, gPB + ETH_ARP_SRC_MAC_P);
EtherCard::copyMac(mac, gPB + ETH_ARP_SRC_MAC_P);
return 1;
}

Expand All @@ -447,7 +470,10 @@ void EtherCard::updateBroadcastAddress()
}

static void client_syn(uint8_t srcport,uint8_t dstport_h,uint8_t dstport_l) {
setMACandIPs(gwmacaddr, EtherCard::hisip);
if(is_lan(EtherCard::myip, EtherCard::hisip)) {
setMACandIPs(destmacaddr, EtherCard::hisip);
} else
setMACandIPs(gwmacaddr, EtherCard::hisip);
gPB[ETH_TYPE_H_P] = ETHTYPE_IP_H_V;
gPB[ETH_TYPE_L_P] = ETHTYPE_IP_L_V;
memcpy_P(gPB + IP_P,iphdr,9);
Expand Down Expand Up @@ -624,34 +650,55 @@ uint16_t EtherCard::accept(const uint16_t port, uint16_t plen) {

uint16_t EtherCard::packetLoop (uint16_t plen) {
uint16_t len;

if(using_dhcp){
ether.DhcpStateMachine(plen);
}

if (plen==0) {
//Check every 65536 (no-packet) cycles whether we need to retry ARP request for gateway
if ((waitgwmac & WGW_INITIAL_ARP || waitgwmac & WGW_REFRESHING) &&
delaycnt==0 && isLinkUp())
delaycnt==0 && isLinkUp()) {
client_arp_whohas(gwip);
waitgwmac |= WGW_ACCEPT_ARP_REPLY;
}
delaycnt++;
//Initiate TCP/IP session if pending
if (tcp_client_state==1 && (waitgwmac & WGW_HAVE_GW_MAC)) { // send a syn
tcp_client_state = 2;
tcpclient_src_port_l++; // allocate a new port
client_syn(((tcp_fd<<5) | (0x1f & tcpclient_src_port_l)),tcp_client_port_h,tcp_client_port_l);
}
return 0;
//!@todo this is trying to find mac only once. Need some timeout to make another call if first one doesn't succeed.
if(is_lan(myip, dnsip) && !has_dns_mac && !waiting_for_dns_mac) {
client_arp_whohas(dnsip);
waiting_for_dns_mac = true;
}
//!@todo this is trying to find mac only once. Need some timeout to make another call if first one doesn't succeed.
if(is_lan(myip, hisip) && !has_dest_mac && !waiting_for_dest_mac) {
client_arp_whohas(hisip);
waiting_for_dest_mac = true;
}

return 0;
}

if (eth_type_is_arp_and_my_ip(plen))
{ //Service ARP request
if (gPB[ETH_ARP_OPCODE_L_P]==ETH_ARP_OPCODE_REQ_L_V)
make_arp_answer_from_request();
if (waitgwmac & WGW_ACCEPT_ARP_REPLY && (gPB[ETH_ARP_OPCODE_L_P]==ETH_ARP_OPCODE_REPLY_L_V) && client_store_gw_mac())
if (waitgwmac & WGW_ACCEPT_ARP_REPLY && (gPB[ETH_ARP_OPCODE_L_P]==ETH_ARP_OPCODE_REPLY_L_V) && client_store_mac(gwip, gwmacaddr))
waitgwmac = WGW_HAVE_GW_MAC;
if (!has_dns_mac && waiting_for_dns_mac && client_store_mac(dnsip, destmacaddr)) {
has_dns_mac = true;
waiting_for_dns_mac = false;
}
if (!has_dest_mac && waiting_for_dest_mac && client_store_mac(hisip, destmacaddr)){
has_dest_mac = true;
waiting_for_dest_mac = false;
}
return 0;
}

if (eth_type_is_ip_and_my_ip(plen)==0)
{ //Not IP so ignoring
//!@todo Add other protocols (and make each optional at compile time)
Expand Down

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