/* This is called by dev loop in order to ensure correct ethernet addressing.
* Returns 0 if the destination is unknown, and -1 if the packet is not deliverable
* due to ethernet addressing (i.e., no arp association was possible.
*
* Only IP packets must pass by this. ARP will always use direct dev->send() function, so
* we assume IP is used.
*/
int32_t pico_ethernet_send(struct pico_frame *f)
{
const struct pico_eth *dstmac = NULL;
int32_t ret = -1;
if (IS_IPV6(f)) {
/*TODO: Neighbor solicitation */
dstmac = NULL;
}
else if (IS_IPV4(f)) {
if (IS_BCAST(f) || destination_is_bcast(f)) {
dstmac = (const struct pico_eth *const) PICO_ETHADDR_ALL;
}
#ifdef PICO_SUPPORT_MCAST
else if (destination_is_mcast(f)) {
uint8_t pico_mcast_mac[6] = {
0x01, 0x00, 0x5e, 0x00, 0x00, 0x00
};
dstmac = pico_ethernet_mcast_translate(f, pico_mcast_mac);
}
#endif
else {
dstmac = pico_arp_get(f);
if (!dstmac)
return 0;
}
/* This sets destination and source address, then pushes the packet to the device. */
if (dstmac && (f->start > f->buffer) && ((f->start - f->buffer) >= PICO_SIZE_ETHHDR)) {
struct pico_eth_hdr *hdr;
f->start -= PICO_SIZE_ETHHDR;
f->len += PICO_SIZE_ETHHDR;
f->datalink_hdr = f->start;
hdr = (struct pico_eth_hdr *) f->datalink_hdr;
memcpy(hdr->saddr, f->dev->eth->mac.addr, PICO_SIZE_ETH);
memcpy(hdr->daddr, dstmac, PICO_SIZE_ETH);
hdr->proto = PICO_IDETH_IPV4;
if(!memcmp(hdr->daddr, hdr->saddr, PICO_SIZE_ETH)) {
dbg("sending out packet destined for our own mac\n");
return pico_ethernet_receive(f);
} else if(IS_LIMITED_BCAST(f)) {
ret = pico_device_broadcast(f);
} else {
ret = (int32_t)f->dev->send(f->dev, f->start, (int) f->len);
/* Frame is discarded after this return by the caller */
}
if(!ret) pico_frame_discard(f);
return ret;
} else {
return -1;
}
} /* End IPV4 ethernet addressing */
return -1;
}
/* Ethernet send, first attempt: try our own address.
* Returns 0 if the packet is not for us.
* Returns 1 if the packet is cloned to our own receive queue, so the caller can discard the original frame.
* */
static int32_t pico_ethsend_local(struct pico_frame *f, struct pico_eth_hdr *hdr)
{
if (!hdr)
return 0;
/* Check own mac */
if(!memcmp(hdr->daddr, hdr->saddr, PICO_SIZE_ETH)) {
struct pico_frame *clone = pico_frame_copy(f);
dbg("sending out packet destined for our own mac\n");
(void)pico_ethernet_receive(clone);
return 1;
}
return 0;
}