/*------------------------------------------------------------------------
* udp_send - send a UDP packet
*------------------------------------------------------------------------
*/
status udp_send (
uint32 remip, /* remote IP address or IP_BCAST*/
/* for a local broadcast */
uint16 remport, /* remote UDP protocol port */
uint32 locip, /* local IP address */
uint16 locport, /* local UDP protocol port */
char *buff, /* buffer of UDP data */
int32 len /* length of data in buffer */
)
{
struct eth_packet pkt; /* ptr to packet being read */
struct ipv4_packet *ippkt = (struct ipv4_packet *)(pkt.net_ethdata);
struct udp_packet *udppkt = (struct udp_packet *)(ippkt->net_ipdata);
int32 pktlen; /* total packet length */
static uint16 ident = 1; /* datagram IDENT field */
char *udataptr; /* pointer to UDP data */
byte ethbcast[] = {0xff,0xff,0xff,0xff,0xff,0xff};
/* Compute packet length as UDP data size + fixed header size */
pktlen = ((char *)(udppkt->net_udpdata) - (char *)&pkt) + len;
/* Create UDP packet in pkt */
memcpy(pkt.net_ethsrc, NetData.ethaddr, ETH_ADDR_LEN);
pkt.net_ethtype = 0x0800; /* Type is IP */
ippkt->net_ipvh = 0x45; /* IP version and hdr length */
ippkt->net_iptos = 0x00; /* Type of service */
ippkt->net_iplen= pktlen - ETH_HDR_LEN;/* total IP datagram length */
ippkt->net_ipid = ident++; /* datagram gets next IDENT */
ippkt->net_ipfrag = 0x0000; /* IP flags & fragment offset */
ippkt->net_ipttl = 0xff; /* IP time-to-live */
ippkt->net_ipproto = IP_UDP; /* datagram carries UDP */
ippkt->net_ipcksum = 0x0000; /* initial checksum */
ippkt->net_ipsrc = locip; /* IP source address */
ippkt->net_ipdst = remip; /* IP destination address */
udppkt->net_udpsport = locport; /* local UDP protocol port */
udppkt->net_udpdport = remport; /* remote UDP protocol port */
udppkt->net_udplen = (uint16)(UDP_HDR_LEN+len); /* UDP length */
udppkt->net_udpcksum = 0x0000; /* ignore UDP checksum */
udataptr = (char *) udppkt->net_udpdata;
for (; len>0; len--) {
*udataptr++ = *buff++;
}
/* Set MAC address in packet, using ARP if needed */
//kprintf("Udp_send called with ip : %x\r\n", remip);
if (remip == IP_BCAST) { /* set mac address to b-cast */
memcpy(pkt.net_ethdst, ethbcast, ETH_ADDR_LEN);
/* If destination isn't on the same subnet, send to router */
} else if ((locip & NetData.addrmask)
!= (remip & NetData.addrmask)) {
//kprintf("localip [%08x] NetData.addrmask [%08x] remote ip [%08x] 12 [%08x] 23 [%08x]\r\n",
//locip, NetData.addrmask, remip, locip&NetData.addrmask, remip & NetData.addrmask);
if (arp_resolve(NetData.routeraddr, pkt.net_ethdst)!=OK) {
kprintf("udp_send: cannot resolve router %08x\n\r",
NetData.routeraddr);
return SYSERR;
}
} else {
/* Destination is on local subnet - get MAC address */
//kprintf("UDP_Send trying to resolve address : %x\r\n", remip);
if (arp_resolve(remip, pkt.net_ethdst) != OK) {
kprintf("udp_send: cannot resolve %08x\n\r",remip);
return SYSERR;
}
}
/* Convert IP and UDP header fields from net to host byte order */
udp_hton(udppkt);
ip_hton(ippkt);
eth_hton(&pkt);
//kprintf("Cleared conversion of header fields\r\n");
/* Compute IP header checksum */
ippkt->net_ipcksum = 0xffff & ipcksum(ippkt);
//kprintf("Writing to ethernet device\r\n");
write(ETHER0, (char *)&pkt, pktlen);
return OK;
}
/*------------------------------------------------------------------------
* arp_resolve - Use ARP to resolve an IP address to an Ethernet address
*------------------------------------------------------------------------
*/
status arp_resolve (
uint32 nxthop, /* Next-hop address to resolve */
byte mac[ETH_ADDR_LEN] /* Array into which Ethernet */
) /* address should be placed */
{
intmask mask; /* Saved interrupt mask */
struct arppacket apkt; /* Local packet buffer */
int32 i; /* Index into arpcache */
int32 slot; /* ARP table slot to use */
struct arpentry *arptr; /* Ptr to ARP cache entry */
int32 msg; /* Message returned by recvtime */
/* Use MAC broadcast address for IP limited broadcast */
if (nxthop == IP_BCAST) {
memcpy(mac, NetData.ethbcast, ETH_ADDR_LEN);
return OK;
}
/* Use MAC broadcast address for IP network broadcast */
if (nxthop == NetData.ipbcast) {
memcpy(mac, NetData.ethbcast, ETH_ADDR_LEN);
return OK;
}
/* Ensure only one process uses ARP at a time */
mask = disable();
/* See if next hop address is already present in ARP cache */
for (i=0; i<ARP_SIZ; i++) {
arptr = &arpcache[i];
if (arptr->arstate == AR_FREE) {
continue;
}
if (arptr->arpaddr == nxthop) { /* Adddress is in cache */
break;
}
}
if (i < ARP_SIZ) { /* Entry was found */
/* If entry is resolved - handle and return */
if (arptr->arstate == AR_RESOLVED) {
memcpy(mac, arptr->arhaddr, ARP_HALEN);
restore(mask);
return OK;
}
/* Entry is already pending - return error because */
/* only one process can be waiting at a time */
if (arptr->arstate == AR_PENDING) {
restore(mask);
return SYSERR;
}
}
/* IP address not in cache - allocate a new cache entry and */
/* send an ARP request to obtain the answer */
slot = arp_alloc();
if (slot == SYSERR) {
restore(mask);
return SYSERR;
}
arptr = &arpcache[slot];
arptr->arstate = AR_PENDING;
arptr->arpaddr = nxthop;
arptr->arpid = currpid;
/* Hand-craft an ARP Request packet */
memcpy(apkt.arp_ethdst, NetData.ethbcast, ETH_ADDR_LEN);
memcpy(apkt.arp_ethsrc, NetData.ethucast, ETH_ADDR_LEN);
apkt.arp_ethtype = ETH_ARP; /* Packet type is ARP */
apkt.arp_htype = ARP_HTYPE; /* Hardware type is Ethernet */
apkt.arp_ptype = ARP_PTYPE; /* Protocol type is IP */
apkt.arp_hlen = 0xff & ARP_HALEN; /* Ethernet MAC size in bytes */
apkt.arp_plen = 0xff & ARP_PALEN; /* IP address size in bytes */
apkt.arp_op = 0xffff & ARP_OP_REQ;/* ARP type is Request */
memcpy(apkt.arp_sndha, NetData.ethucast, ARP_HALEN);
apkt.arp_sndpa = NetData.ipucast; /* IP address of interface */
memset(apkt.arp_tarha, '\0', ARP_HALEN); /* Target HA is unknown*/
apkt.arp_tarpa = nxthop; /* Target protocol address */
/* Convert ARP packet from host to net byte order */
arp_hton(&apkt);
/* Convert Ethernet header from host to net byte order */
eth_hton((struct netpacket *)&apkt);
/* Send the packet ARP_RETRY times and await response */
msg = recvclr();
for (i=0; i<ARP_RETRY; i++) {
write(ETHER0, (char *)&apkt, sizeof(struct arppacket));
msg = recvtime(ARP_TIMEOUT);
if (msg == TIMEOUT) {
continue;
} else if (msg == SYSERR) {
restore(mask);
return SYSERR;
} else { /* entry is resolved */
break;
}
}
/* If no response, return TIMEOUT */
if (msg == TIMEOUT) {
arptr->arstate = AR_FREE; /* Invalidate cache entry */
restore(mask);
return TIMEOUT;
}
/* Return hardware address */
memcpy(mac, arptr->arhaddr, ARP_HALEN);
restore(mask);
return OK;
}
status rpl_send_with_ip(char * node_phy_addr, char *src_node, byte msg_type, char *msg, uint32 msg_len, uint32 remip){
struct eth_packet pkt;
struct rpl_sim_packet *rpl_sim_pkt = NULL;
byte ethbcast[] = {0xff,0xff,0xff,0xff,0xff,0xff};
#ifdef DEBUG
kprintf("Simulator is : %04x dest : %04x source : %04x my addr : %04x\r\n", remip, *((uint32*)node_phy_addr), *((uint32*)src_node), NetData.ipaddr);
#endif
if ( ! NetData.ipvalid){
getlocalip();
}
if(msg_len > 1500-ETH_HDR_LEN-RPL_SIM_HDR_LEN){
kprintf("WARN : Simulator : Message too big \r\n");
return SYSERR;
}
memcpy(pkt.net_ethsrc, NetData.ethaddr, ETH_ADDR_LEN);
/* FIXME : Needs to be changed to something that is valid */
pkt.net_ethtype = 0x1000;
if (remip == IP_BCAST) { /* set mac address to b-cast */
memcpy(pkt.net_ethdst, ethbcast, ETH_ADDR_LEN);
/* If destination isn't on the same subnet, send to router */
} else if ((NetData.ipaddr & NetData.addrmask)
!= (remip & NetData.addrmask)) {
if (arp_resolve(NetData.routeraddr, pkt.net_ethdst)!=OK) {
kprintf("rpl_send: cannot resolve router %08x\n\r",
NetData.routeraddr);
return SYSERR;
}
} else {
/* Destination is on local subnet - get MAC address */
if (arp_resolve(remip, pkt.net_ethdst) != OK) {
kprintf("rpl_send: cannot resolve %08x\n\r",remip);
return SYSERR;
}
}
rpl_sim_pkt = (struct rpl_sim_packet *)pkt.net_ethdata;
memcpy((char *)rpl_sim_pkt->dest_node, (char *)node_phy_addr, RPL_NODE_PHY_ADDR_LEN);
/*
* FIXME Change this to my_phsical_address which is 64 bits
*/
memcpy((char *)rpl_sim_pkt->src_node, (char *)(src_node), RPL_NODE_PHY_ADDR_LEN);
rpl_sim_pkt->msg_type = msg_type;
rpl_sim_pkt->msg_len = msg_len;
memcpy(rpl_sim_pkt->data, msg, msg_len);
/*
* FIXME : Perform host to network order translations
*/
#ifdef DEBUG
kprintf("The packet is destined for : %06x with length : %d\r\n", *(pkt.net_ethdst+4), msg_len);
#endif
eth_hton(&pkt);
write(ETHER0, (char *)&pkt, ETH_HDR_LEN + RPL_SIM_HDR_LEN + msg_len);
return OK;
}
/*------------------------------------------------------------------------
* arp_in - Handle an incoming ARP packet
*------------------------------------------------------------------------
*/
void arp_in (
struct arppacket *pktptr /* Ptr to incoming packet */
)
{
intmask mask; /* Saved interrupt mask */
struct arppacket apkt; /* Local packet buffer */
int32 slot; /* Slot in cache */
struct arpentry *arptr; /* Ptr to ARP cache entry */
bool8 found; /* Is the sender's address in */
/* the cache? */
/* Convert packet from network order to host order */
arp_ntoh(pktptr);
/* Verify ARP is for IPv4 and Ethernet */
if ( (pktptr->arp_htype != ARP_HTYPE) ||
(pktptr->arp_ptype != ARP_PTYPE) ) {
freebuf((char *)pktptr);
return;
}
/* Ensure only one process uses ARP at a time */
mask = disable();
/* Search cache for sender's IP address */
found = FALSE;
for (slot=0; slot < ARP_SIZ; slot++) {
arptr = &arpcache[slot];
/* Skip table entries that are unused */
if (arptr->arstate == AR_FREE) {
continue;
}
/* If sender's address matches, we've found it */
if (arptr->arpaddr == pktptr->arp_sndpa) {
found = TRUE;
break;
}
}
if (found) {
/* Update sender's hardware address */
memcpy(arptr->arhaddr, pktptr->arp_sndha, ARP_HALEN);
/* If a process was waiting, inform the process */
if (arptr->arstate == AR_PENDING) {
/* Mark resolved and notify waiting process */
arptr->arstate = AR_RESOLVED;
arptr->time = clktime;
send(arptr->arpid, OK);
}
}
/* For an ARP reply, processing is complete */
if (pktptr->arp_op == ARP_OP_RPLY) {
freebuf((char *)pktptr);
restore(mask);
return;
}
/* The following is for an ARP request packet: if the local */
/* machine is not the target or the local IP address is not */
/* yet known, ignore the request (i.e., processing is complete)*/
if ((!NetData.ipvalid) ||
(pktptr->arp_tarpa != NetData.ipucast)) {
freebuf((char *)pktptr);
restore(mask);
return;
}
/* Request has been sent to the local machine's address. So, */
/* add sender's info to cache, if not already present */
if (!found) {
slot = arp_alloc();
if (slot == SYSERR) { /* Cache is full */
kprintf("ARP cache overflow on interface\n");
freebuf((char *)pktptr);
restore(mask);
return;
}
arptr = &arpcache[slot];
arptr->arpaddr = pktptr->arp_sndpa;
memcpy(arptr->arhaddr, pktptr->arp_sndha, ARP_HALEN);
arptr->arstate = AR_RESOLVED;
}
/* Hand-craft an ARP reply packet and send back to requester */
memcpy(apkt.arp_ethdst, pktptr->arp_sndha, ARP_HALEN);
memcpy(apkt.arp_ethsrc, NetData.ethucast, ARP_HALEN);
apkt.arp_ethtype= ETH_ARP; /* Frame carries ARP */
apkt.arp_htype = ARP_HTYPE; /* Hardware is Ethernet */
apkt.arp_ptype = ARP_PTYPE; /* Protocol is IP */
apkt.arp_hlen = ARP_HALEN; /* Ethernet address size*/
apkt.arp_plen = ARP_PALEN; /* IP address size */
apkt.arp_op = ARP_OP_RPLY; /* Type is Reply */
/* Insert local Ethernet and IP address in sender fields */
memcpy(apkt.arp_sndha, NetData.ethucast, ARP_HALEN);
apkt.arp_sndpa = NetData.ipucast;
/* Copy target Ethernet and IP addresses from request packet */
memcpy(apkt.arp_tarha, pktptr->arp_sndha, ARP_HALEN);
apkt.arp_tarpa = pktptr->arp_sndpa;
/* Convert ARP packet from host to network byte order */
arp_hton(&apkt);
/* Convert the Ethernet header to network byte order */
eth_hton((struct netpacket *)&apkt);
/* Send the reply */
write(ETHER0, (char *)&apkt, sizeof(struct arppacket));
freebuf((char *)pktptr);
restore(mask);
return;
}
