simple reliable networking over ethernet. Provides IPv4 ARP, ICMP echo reply, and UDP unicast. Does NOT provide TCP, that's not simple :-).
snet.cpp
- Committer:
- altasoul
- Date:
- 2015-03-04
- Revision:
- 0:6df0a6ed91d4
- Child:
- 1:9c211ac06a12
File content as of revision 0:6df0a6ed91d4:
#include "snet.h" //extern MODSERIAL pc; //extern void print_hex(uint8_t *p, int len); //volatile uint32_t enet_rx_cnt; //volatile int enet_rx_balance; extern uint8_t my_ip[4]; //uint8_t correspondent_mac[6]; // correspondent's MAC const uint8_t Snet::broadcast_mac[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; //const char ourEtherType[] = { 0x82, 0x48 }; const uint8_t Snet::ipEtherType[] = { 0x08, 0x00 }; const uint8_t Snet::arp_req_payload_prefix[] = { 0x0, 0x1, 0x8, 0x0, 0x6, 0x4, 0x0, 0x1 }; extern void interpret_inet_packet(uint8_t *buf, int len); extern void send_packet_to_radio(uint8_t const *, int); Snet::Snet(): eth() { eth.address((char *) my_mac); printf("MAC %02x:%02x:%02x:%02x:%02x:%02x\r\n", my_mac[0], my_mac[1], my_mac[2], my_mac[3], my_mac[4], my_mac[5]); printf("no IP\r\n"); #if 0 // FIXME LPC_EMAC->IntEnable = 0; // disable all Ethernet interrupts LPC_EMAC->IntClear = ~0; // clear all interrupts //enet_rx_balance = 0; // Enable Ethernet TX and RX Packet Interrupts: //LPC_EMAC->IntEnable |= (ETH_RxFinishedInt | ETH_TxFinishedInt); LPC_EMAC->IntEnable |= (ETH_RxDoneInt | ETH_TxDoneInt); NVIC_SetPriority(ENET_IRQn, 0); // lower numbers have priority // Enable the interrupt. NVIC_EnableIRQ(ENET_IRQn); #endif } Snet::Snet(const uint8_t *ip): eth() { eth.address((char *) my_mac); printf("MAC %02x:%02x:%02x:%02x:%02x:%02x\r\n", my_mac[0], my_mac[1], my_mac[2], my_mac[3], my_mac[4], my_mac[5]); memcpy(my_ip, ip, 4); printf("IP %d.%d.%d.%d\r\n", my_ip[0], my_ip[1], my_ip[2], my_ip[3]); #if 0 // FIXME LPC_EMAC->IntEnable = 0; // disable all Ethernet interrupts LPC_EMAC->IntClear = ~0; // clear all interrupts //enet_rx_balance = 0; // Enable Ethernet TX and RX Packet Interrupts: //LPC_EMAC->IntEnable |= (ETH_RxFinishedInt | ETH_TxFinishedInt); LPC_EMAC->IntEnable |= (ETH_RxDoneInt | ETH_TxDoneInt); NVIC_SetPriority(ENET_IRQn, 0); // lower numbers have priority // Enable the interrupt. NVIC_EnableIRQ(ENET_IRQn); #endif } void Snet::handle_arp_request(uint8_t *buf, int len) { #if 0 printf("Arp from %02x:%02x:%02x:%02x:%02x:%02x ", buf[ENET_SMAC_O+0], buf[ENET_SMAC_O+1], buf[ENET_SMAC_O+2], buf[ENET_SMAC_O+3], buf[ENET_SMAC_O+4], buf[ENET_SMAC_O+5]);*/ #endif eth.read((char *) &buf[ENET_PAYLOAD_O], len-ENET_PAYLOAD_O); /*print_hex((uint8_t *) &buf[ENET_PAYLOAD_O], len-ENET_PAYLOAD_O);*/ if (!(memcmp(&buf[ENET_PAYLOAD_O], arp_req_payload_prefix, sizeof(arp_req_payload_prefix)) // ARP request || memcmp(&buf[ENET_ARP_TPA_O], my_ip, sizeof(my_ip)))) { // for me //ARP request for me. Build reply. // Ethernet packet addresses: memcpy(&buf[ENET_DMAC_O], &buf[ENET_SMAC_O], 6); // Back to sender memcpy(&buf[ENET_SMAC_O], my_mac, 6); // from me // ARP protocol packet: buf[ENET_ARP_OPER_O+1] = 0x02; // we are replying memcpy(&buf[ENET_ARP_THA_O], &buf[ENET_ARP_SHA_O], 6); // to hardware address of request sender memcpy(&buf[ENET_ARP_TPA_O], &buf[ENET_ARP_SPA_O], 4); // to IP address of request sender memcpy(&buf[ENET_ARP_SHA_O], my_mac, 6); // from my hardware address memcpy(&buf[ENET_ARP_SPA_O], my_ip, 4); // and my IP address //printf("ARP replying\r\n"); //print_hex((uint8_t *) buf, len); eth.write((char *) buf, len); eth.send(); }; }; void Snet::got_broadcast(uint8_t *buf, int len) { #if 0 printf("Broadcast from: %02x:%02x:%02x:%02x:%02x:%02x type %02x%02x count %d\r\n", buf[ENET_SMAC_O+0], buf[ENET_SMAC_O+1], buf[ENET_SMAC_O+2], buf[ENET_SMAC_O+3], buf[ENET_SMAC_O+4], buf[ENET_SMAC_O+5], buf[ENET_ETHERTYPE_O+0], buf[ENET_ETHERTYPE_O+1], enet_rx_int_cnt); #endif // ARP request? if (buf[ENET_ETHERTYPE_O+0] == 0x08 && buf[ENET_ETHERTYPE_O+1] == 0x06) handle_arp_request(buf, len); }; void Snet::got_unicast(uint8_t *buf, int len) { if (memcmp(&buf[ENET_ETHERTYPE_O], ipEtherType, 2)) return; // IP packets only from this point // printf("Unicast from: %02x:%02x:%02x:%02x:%02x:%02x %d\r\n", // buf[6], buf[7], buf[8], buf[9], buf[10], buf[11], enet_rx_int_cnt); memcpy(correspondent_mac, &buf[ENET_SMAC_O], sizeof(correspondent_mac)); eth.read((char *) &buf[ENET_PAYLOAD_O], len-ENET_PAYLOAD_O); // Read in the whole rest of the packet interpret_inet_packet(buf, len); } int Snet::rx_and_process_one_packet() { #if 0 // if the damn Ethernet worked correctly: uint8_t buf[0x600]; #else uint8_t buf[750+6+6+2]; // Experimentally-derived maximum packet size is 750 at the IP layer #endif int rv = 0; int len; while ((len = eth.receive()) > 0) { eth.read((char *) buf, ENET_PAYLOAD_O); // destination MAC, source MAC, EtherType, lengcode enet_rx_cnt++; if (memcmp(&buf[ENET_DMAC_O], my_mac, 6) == 0) { got_unicast(buf, len); rv = 1; } else if (memcmp(&buf[ENET_DMAC_O], broadcast_mac, 6) == 0) { got_broadcast(buf, len); rv = 2; } } return rv; }