net: consume descriptor on tx

kernel-src/include/kernel/net.h

@@ -44,6 +44,7 @@ typedef struct netdev_t {
 	short flags;
 	int (*allocdesc)(struct netdev_t *netdev, size_t requestedsize, netdesc_t *desc);
 	int (*freedesc)(struct netdev_t *netdev, netdesc_t *desc);
+	// consumes desc regardless of the returned status
 	int (*sendpacket)(struct netdev_t *_internal, netdesc_t desc, mac_t targetmac, int proto);
 } netdev_t;
 

kernel-src/io/net/arp.c

@@ -146,8 +146,7 @@ static void send_reply(netdev_t *netdev, uint32_t ip, mac_t mac) {
 
 	memcpy((void *)((uintptr_t)desc.address + desc.curroffset), &frame, sizeof(frame));
 
-	e = netdev->sendpacket(netdev, desc, mac, ETH_PROTO_ARP);
-	netdev->freedesc(netdev, &desc);
+	netdev->sendpacket(netdev, desc, mac, ETH_PROTO_ARP);
 }
 
 static void handlerthreadfn() {
@@ -237,7 +236,6 @@ static int sendrequest(netdev_t *netdev, uint32_t ip) {
 	memcpy((void *)((uintptr_t)desc.address + desc.curroffset), &frame, sizeof(frame));
 
 	e = netdev->sendpacket(netdev, desc, NET_BROADCAST_MAC, ETH_PROTO_ARP);
-	netdev->freedesc(netdev, &desc);
 	return e;
 }
 

kernel-src/io/net/ipv4.c

@@ -215,7 +215,6 @@ int ipv4_sendpacket(void *buffer, size_t packetsize, uint32_t ip, int proto, net
 		memcpy((void *)((uintptr_t)fragdesc.address + fragdesc.curroffset + sizeof(ipv4frame_t)), (void *)((uintptr_t)buffer + i * devfragmentsize), fragmentlen);
 
 		e = dispatch_fragment(netdev, fragdesc, i * devfragmentsize, fragmentlen, id, ip, mac, proto, i == fragmentcount - 1);
-		netdev->freedesc(netdev, &fragdesc);
 		if (e)
 			return e;
 	}

kernel-src/io/net/loopback.c

@@ -6,13 +6,10 @@
 #include <hashtable.h>
 #include <arch/cpu.h>
 #include <kernel/init.h>
+#include <kernel/interrupt.h>
 
 static netdev_t loopbacknetdev;
 
-static void rx_dpc(context_t *context, dpcarg_t arg) {
-	eth_process(&loopbacknetdev, arg);
-}
-
 // requested size doesn't account for ethernet header or the virtio header
 static int loopback_allocdesc(netdev_t *netdev, size_t requestedsize, netdesc_t *desc) {
 	__assert(requestedsize <= netdev->mtu);
@@ -42,11 +39,11 @@ static int loopback_sendpacket(netdev_t *netdev, netdesc_t desc, mac_t targetmac
 	memcpy(&ethframe.destination, &broadcast, sizeof(mac_t));
 	memcpy(desc.address, &ethframe, sizeof(ethframe_t));
 
-	dpc_t dpc = {0};
-	dpc_prepare(&dpc, rx_dpc);
-	dpc_enqueue(&dpc, desc.address);
+	long ipl = interrupt_raiseipl(IPL_DPC);
+	eth_process(netdev, desc.address);
+	interrupt_loweripl(ipl);
 
-	return 0;
+	return netdev->freedesc(netdev, &desc);
 }
 
 netdev_t *loopback_device() {

kernel-src/io/net/rtl8169.c

@@ -191,7 +191,7 @@ static int rtl8169_sendpacket(netdev_t *internal, netdesc_t desc, mac_t target,
 	spinlock_release_lower_ipl(&netdev->tx_lock, ipl);
 	sched_yield();
 
-	return 0;
+	return internal->freedesc(internal, &desc);
 }
 
 // requested size doesn't account for ethernet header

kernel-src/io/net/vionet.c

@@ -148,7 +148,7 @@ static int vionet_sendpacket(netdev_t *internal, netdesc_t desc, mac_t targetmac
 	sched_yield();
 
 	interrupt_set(intstatus);
-	return 0;
+	return internal->freedesc(internal, &desc);
 }
 
 int vionet_newdevice(viodevice_t *viodevice) {