/* Network Interface functions */
static void
utun_start(ifnet_t interface)
{
mbuf_t data;
struct utun_pcb*pcb = ifnet_softc(interface);
for (;;) {
bool can_accept_packets = true;
ifnet_lock_shared(pcb->utun_ifp);
can_accept_packets = (pcb->utun_pending_packets < pcb->utun_max_pending_packets);
if (!can_accept_packets && pcb->utun_ctlref) {
u_int32_t difference = 0;
if (ctl_getenqueuereadable(pcb->utun_ctlref, pcb->utun_unit, &difference) == 0) {
if (difference > 0) {
// If the low-water mark has not yet been reached, we still need to enqueue data
// into the buffer
can_accept_packets = true;
}
}
}
if (!can_accept_packets) {
errno_t error = ifnet_disable_output(interface);
if (error != 0) {
printf("utun_start: ifnet_disable_output returned error %d\n", error);
}
ifnet_lock_done(pcb->utun_ifp);
break;
}
ifnet_lock_done(pcb->utun_ifp);
if (ifnet_dequeue(interface, &data) != 0)
break;
if (utun_output(interface, data) != 0)
break;
}
}
static void
utun_ctl_rcvd(kern_ctl_ref kctlref, u_int32_t unit, void *unitinfo, int flags)
{
#pragma unused(flags)
bool reenable_output = false;
struct utun_pcb *pcb = unitinfo;
if (pcb == NULL) {
return;
}
ifnet_lock_exclusive(pcb->utun_ifp);
u_int32_t utun_packet_cnt;
errno_t error_pc = ctl_getenqueuepacketcount(kctlref, unit, &utun_packet_cnt);
if (error_pc != 0) {
printf("utun_ctl_rcvd: ctl_getenqueuepacketcount returned error %d\n", error_pc);
utun_packet_cnt = 0;
}
if (utun_packet_cnt < pcb->utun_max_pending_packets) {
reenable_output = true;
}
if (reenable_output) {
errno_t error = ifnet_enable_output(pcb->utun_ifp);
if (error != 0) {
printf("utun_ctl_rcvd: ifnet_enable_output returned error %d\n", error);
}
}
ifnet_lock_done(pcb->utun_ifp);
}
int
if_set_low_power(ifnet_t ifp, bool on)
{
int error = 0;
if (ifp == NULL)
return (EINVAL);
os_log(OS_LOG_DEFAULT,
"%s: ifp %s low_power mode %d", __func__, if_name(ifp), on);
ifnet_lock_exclusive(ifp);
ifp->if_xflags = on ? (ifp->if_xflags | IFXF_LOW_POWER) :
(ifp->if_xflags & ~IFXF_LOW_POWER);
ifnet_lock_done(ifp);
return (error);
}
static void
if_low_power_evhdlr_callback(__unused struct eventhandler_entry_arg arg,
struct ifnet *ifp, if_low_power_ev_code_t event_code)
{
struct kev_dl_low_power_mode kev;
if (!IF_FULLY_ATTACHED(ifp))
return;
if (if_low_power_verbose > 0) {
os_log_info(OS_LOG_DEFAULT,
"%s: ifp %s event_code %d", __func__,
if_name(ifp), event_code);
}
ifnet_lock_exclusive(ifp);
if (event_code == IF_LOW_POWER_EVENT_OFF) {
ifp->if_xflags &= ~IFXF_LOW_POWER;
} else {
ifp->if_xflags |= IFXF_LOW_POWER;
}
ifnet_lock_done(ifp);
if (event_code == IF_LOW_POWER_EVENT_ON) {
atomic_add_32(&ifp->if_low_power_gencnt, 1);
if (if_low_power_restricted != 0) {
shutdown_sockets_on_interface(ifp);
intf_event_enqueue_nwk_wq_entry(ifp, NULL,
INTF_EVENT_CODE_LOW_POWER_UPDATE);
}
}
bzero(&kev, sizeof(struct kev_dl_low_power_mode));
kev.low_power_event = event_code;
dlil_post_msg(ifp,
KEV_DL_SUBCLASS,
KEV_DL_LOW_POWER_MODE_CHANGED,
(struct net_event_data *)&kev,
sizeof(struct kev_dl_low_power_mode));
}
static errno_t
utun_output(
ifnet_t interface,
mbuf_t data)
{
struct utun_pcb *pcb = ifnet_softc(interface);
errno_t result;
if (m_pktlen(data) >= 4) {
bpf_tap_out(pcb->utun_ifp, DLT_NULL, data, 0, 0);
}
if (pcb->utun_flags & UTUN_FLAGS_NO_OUTPUT) {
/* flush data */
mbuf_freem(data);
return 0;
}
// otherwise, fall thru to ctl_enqueumbuf
if (pcb->utun_ctlref) {
int length;
// only pass packets to utun-crypto if crypto is enabled and 'suspend data traffic' is not.
if ((pcb->utun_flags & (UTUN_FLAGS_CRYPTO | UTUN_FLAGS_CRYPTO_STOP_DATA_TRAFFIC)) == UTUN_FLAGS_CRYPTO) {
if (utun_pkt_crypto_output(pcb, &data) == 0) {
return 0;
}
}
/*
* The ABI requires the protocol in network byte order
*/
if (m_pktlen(data) >= 4)
*(u_int32_t *)mbuf_data(data) = htonl(*(u_int32_t *)mbuf_data(data));
length = mbuf_pkthdr_len(data);
// Increment packet count optimistically
ifnet_lock_exclusive(pcb->utun_ifp);
pcb->utun_pending_packets++;
ifnet_lock_done(pcb->utun_ifp);
result = ctl_enqueuembuf(pcb->utun_ctlref, pcb->utun_unit, data, CTL_DATA_EOR);
if (result != 0) {
// Decrement packet count if errored
ifnet_lock_exclusive(pcb->utun_ifp);
pcb->utun_pending_packets--;
ifnet_lock_done(pcb->utun_ifp);
mbuf_freem(data);
printf("utun_output - ctl_enqueuembuf failed: %d\n", result);
ifnet_stat_increment_out(interface, 0, 0, 1);
}
else {
if (!pcb->utun_ext_ifdata_stats)
ifnet_stat_increment_out(interface, 1, length, 0);
}
}
else
mbuf_freem(data);
return 0;
}
