static void backend_create_netif(struct backend_info *be)
{
int err;
long handle;
struct xenbus_device *dev = be->dev;
if (be->netif != NULL)
return;
err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
if (err != 1) {
xenbus_dev_fatal(dev, err, "reading handle");
return;
}
be->netif = netif_alloc(&dev->dev, dev->otherend_id, handle);
if (IS_ERR(be->netif)) {
err = PTR_ERR(be->netif);
be->netif = NULL;
xenbus_dev_fatal(dev, err, "creating interface");
return;
}
kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
}
// ARP请求
void arp_request(u32 req_ip)
{
arp_frm *arp_rep;
eth_frm *eth_arp;
eth_arp = netif_alloc(ETH_HDRLEN + ARP_FRMLEN);
if(eth_arp != NULL)
{
arp_rep = (arp_frm *)(eth_arp->data);
arp_rep->hardware_type = htons(ARP_HWTYPE_ETH);
arp_rep->protocol_type = htons(ARP_PTTYPE_IP);
arp_rep->hw_addr_len = MAC_ADDR_LEN;
arp_rep->pt_addr_len = IP_ADDR_LEN;
arp_rep->operation = htons(ARP_TYPE_REQ);
mem_copy(arp_rep->src_mac, local.mac, MAC_ADDR_LEN);
arp_rep->src_ip.inw = local.ip.inw;
mem_setbytes(arp_rep->dst_mac, 0x00, MAC_ADDR_LEN);
arp_rep->dst_ip.inw = req_ip;
mem_setbytes(eth_arp->dst, 0xFF, MAC_ADDR_LEN);
mem_copy(eth_arp->src, local.mac, MAC_ADDR_LEN);
eth_arp->type = htons(ETH_TYPE_ARP);
netif_push(eth_arp, ETH_HDRLEN + ARP_FRMLEN, &local);
}
}
/**
* Callback received when the hotplug scripts have placed the handle node.
* Read it, and create a netif structure. If the frontend is ready, connect.
*/
static void backend_changed(struct xenbus_watch *watch,
const char **vec, unsigned int len)
{
int err;
long handle;
struct backend_info *be
= container_of(watch, struct backend_info, backend_watch);
struct xenbus_device *dev = be->dev;
DPRINTK("");
err = xenbus_scanf(XBT_NULL, dev->nodename, "handle", "%li", &handle);
if (XENBUS_EXIST_ERR(err)) {
/* Since this watch will fire once immediately after it is
registered, we expect this. Ignore it, and wait for the
hotplug scripts. */
return;
}
if (err != 1) {
xenbus_dev_fatal(dev, err, "reading handle");
return;
}
if (be->netif == NULL) {
u8 be_mac[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 };
be->netif = netif_alloc(dev->otherend_id, handle, be_mac);
if (IS_ERR(be->netif)) {
err = PTR_ERR(be->netif);
be->netif = NULL;
xenbus_dev_fatal(dev, err, "creating interface");
return;
}
kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
maybe_connect(be);
}
}