/* Must be called under rtnl. */
void netmap_catch_tx(struct netmap_generic_adapter *gna, int enable)
{
struct netmap_adapter *na = &gna->up.up;
struct ifnet *ifp = netmap_generic_getifp(gna);
if (enable) {
/*
* Save the old pointer to the netdev_ops,
* create an updated netdev ops replacing the
* ndo_select_queue() and ndo_start_xmit() methods
* with our custom ones, and make the driver use it.
*/
na->if_transmit = (void *)ifp->netdev_ops;
/* Save a redundant copy of ndo_start_xmit(). */
gna->save_start_xmit = ifp->netdev_ops->ndo_start_xmit;
gna->generic_ndo = *ifp->netdev_ops; /* Copy all */
gna->generic_ndo.ndo_start_xmit = &generic_ndo_start_xmit;
#ifndef NETMAP_LINUX_SELECT_QUEUE
printk("%s: no packet steering support\n", __FUNCTION__);
#else
gna->generic_ndo.ndo_select_queue = &generic_ndo_select_queue;
#endif
ifp->netdev_ops = &gna->generic_ndo;
} else {
/* Restore the original netdev_ops. */
ifp->netdev_ops = (void *)na->if_transmit;
}
}
/* Ask the Linux RX subsystem to intercept (or stop intercepting)
* the packets incoming from the interface attached to 'na'.
*/
int
nm_os_catch_rx(struct netmap_generic_adapter *gna, int intercept)
{
#ifndef NETMAP_LINUX_HAVE_RX_REGISTER
return 0;
#else /* HAVE_RX_REGISTER */
struct netmap_adapter *na = &gna->up.up;
struct ifnet *ifp = netmap_generic_getifp(gna);
if (intercept) {
return -netdev_rx_handler_register(ifp,
&linux_generic_rx_handler, na);
} else {
netdev_rx_handler_unregister(ifp);
return 0;
}
#endif /* HAVE_RX_REGISTER */
}
static int
nm_os_catch_qdisc(struct netmap_generic_adapter *gna, int intercept)
{
struct netmap_adapter *na = &gna->up.up;
struct ifnet *ifp = netmap_generic_getifp(gna);
struct nm_generic_qdisc *qdiscopt = NULL;
struct Qdisc *fqdisc = NULL;
struct nlattr *nla = NULL;
struct netdev_queue *txq;
unsigned int i;
if (!gna->txqdisc) {
return 0;
}
if (intercept) {
nla = kmalloc(nla_attr_size(sizeof(*qdiscopt)),
GFP_KERNEL);
if (!nla) {
D("Failed to allocate netlink attribute");
return ENOMEM;
}
nla->nla_type = RTM_NEWQDISC;
nla->nla_len = nla_attr_size(sizeof(*qdiscopt));
qdiscopt = (struct nm_generic_qdisc *)nla_data(nla);
memset(qdiscopt, 0, sizeof(*qdiscopt));
qdiscopt->limit = na->num_tx_desc;
}
if (ifp->flags & IFF_UP) {
dev_deactivate(ifp);
}
/* Replace the current qdiscs with our own. */
for (i = 0; i < ifp->real_num_tx_queues; i++) {
struct Qdisc *nqdisc = NULL;
struct Qdisc *oqdisc;
int err;
txq = netdev_get_tx_queue(ifp, i);
if (intercept) {
/* This takes a refcount to netmap module, alloc the
* qdisc and calls the init() op with NULL netlink
* attribute. */
nqdisc = qdisc_create_dflt(
#ifndef NETMAP_LINUX_QDISC_CREATE_DFLT_3ARGS
ifp,
#endif /* NETMAP_LINUX_QDISC_CREATE_DFLT_3ARGS */
txq, &generic_qdisc_ops,
TC_H_UNSPEC);
if (!nqdisc) {
D("Failed to create qdisc");
goto qdisc_create;
}
fqdisc = fqdisc ?: nqdisc;
/* Call the change() op passing a valid netlink
* attribute. This is used to set the queue idx. */
qdiscopt->qidx = i;
err = nqdisc->ops->change(nqdisc, nla);
if (err) {
D("Failed to init qdisc");
goto qdisc_create;
}
}
oqdisc = dev_graft_qdisc(txq, nqdisc);
/* We can call this also with
* odisc == &noop_qdisc, since the noop
* qdisc has the TCQ_F_BUILTIN flag set,
* and so qdisc_destroy will skip it. */
qdisc_destroy(oqdisc);
}
kfree(nla);
if (ifp->qdisc) {
qdisc_destroy(ifp->qdisc);
}
if (intercept) {
atomic_inc(&fqdisc->refcnt);
ifp->qdisc = fqdisc;
} else {
ifp->qdisc = &noop_qdisc;
}
if (ifp->flags & IFF_UP) {
dev_activate(ifp);
}
return 0;
qdisc_create:
if (nla) {
kfree(nla);
}
nm_os_catch_qdisc(gna, 0);
return -1;
}
