add some definition and driver changes in preparation for

two upcoming features:

semi-transparent mode:
    when a device is opened in this mode, the
    user program will be able to mark slots that must be forwarded
    to the "other" side (i.e. from NIC to host stack, or viceversa),
    and the forwarding will occur automatically at the next netmap syscall.
    This saves the need to open another file descriptor and do
    the forwarding manually.

direct-forwarding mode:
    when operating with a VALE port, the user can specify in the slot
    the actual destination port, overriding the forwarding decision
    made by a lookup of the destination MAC. This can be useful to
    implement packet dispatchers.

No API changes will be introduced.
No new functionality in this patch yet.

6 files changed, 19 insertions, 0 deletions

diff --git a/sys/dev/netmap/if_em_netmap.h b/sys/dev/netmap/if_em_netmap.h
index b4b268ae11a1..776f0e0ee824 100644
--- a/sys/dev/netmap/if_em_netmap.h
+++ b/sys/dev/netmap/if_em_netmap.h
@@ -292,6 +292,8 @@ em_netmap_rxsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
 	l = rxr->next_to_check;
 	j = netmap_idx_n2k(kring, l);
 	if (netmap_no_pendintr || force_update) {
+		uint16_t slot_flags = kring->nkr_slot_flags;
+
 		for (n = 0; ; n++) {
 			struct e1000_rx_desc *curr = &rxr->rx_base[l];
 			uint32_t staterr = le32toh(curr->status);
@@ -299,6 +301,7 @@ em_netmap_rxsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
 			if ((staterr & E1000_RXD_STAT_DD) == 0)
 				break;
 			ring->slot[j].len = le16toh(curr->length);
+			ring->slot[j].flags = slot_flags;
 			bus_dmamap_sync(rxr->rxtag, rxr->rx_buffers[l].map,
 				BUS_DMASYNC_POSTREAD);
 			j = (j == lim) ? 0 : j + 1;
diff --git a/sys/dev/netmap/if_igb_netmap.h b/sys/dev/netmap/if_igb_netmap.h
index bd835634884f..e817341cc9fe 100644
--- a/sys/dev/netmap/if_igb_netmap.h
+++ b/sys/dev/netmap/if_igb_netmap.h
@@ -263,6 +263,8 @@ igb_netmap_rxsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
 	l = rxr->next_to_check;
 	j = netmap_idx_n2k(kring, l);
 	if (netmap_no_pendintr || force_update) {
+		uint16_t slot_flags = kring->nkr_slot_flags;
+
 		for (n = 0; ; n++) {
 			union e1000_adv_rx_desc *curr = &rxr->rx_base[l];
 			uint32_t staterr = le32toh(curr->wb.upper.status_error);
@@ -270,6 +272,7 @@ igb_netmap_rxsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
 			if ((staterr & E1000_RXD_STAT_DD) == 0)
 				break;
 			ring->slot[j].len = le16toh(curr->wb.upper.length);
+			ring->slot[j].flags = slot_flags;
 			bus_dmamap_sync(rxr->ptag,
 				rxr->rx_buffers[l].pmap, BUS_DMASYNC_POSTREAD);
 			j = (j == lim) ? 0 : j + 1;
diff --git a/sys/dev/netmap/if_lem_netmap.h b/sys/dev/netmap/if_lem_netmap.h
index 9f24580a9e8d..d3be70017f8e 100644
--- a/sys/dev/netmap/if_lem_netmap.h
+++ b/sys/dev/netmap/if_lem_netmap.h
@@ -253,6 +253,8 @@ lem_netmap_rxsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
 	l = adapter->next_rx_desc_to_check;
 	j = netmap_idx_n2k(kring, l);
 	if (netmap_no_pendintr || force_update) {
+		uint16_t slot_flags = kring->nkr_slot_flags;
+
 		for (n = 0; ; n++) {
 			struct e1000_rx_desc *curr = &adapter->rx_desc_base[l];
 			uint32_t staterr = le32toh(curr->status);
@@ -266,6 +268,7 @@ lem_netmap_rxsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
 				len = 0;
 			}
 			ring->slot[j].len = len;
+			ring->slot[j].flags = slot_flags;
 			bus_dmamap_sync(adapter->rxtag,
 				adapter->rx_buffer_area[l].map,
 				    BUS_DMASYNC_POSTREAD);
diff --git a/sys/dev/netmap/if_re_netmap.h b/sys/dev/netmap/if_re_netmap.h
index bdd57035b7b5..1c747b7151bc 100644
--- a/sys/dev/netmap/if_re_netmap.h
+++ b/sys/dev/netmap/if_re_netmap.h
@@ -245,6 +245,8 @@ re_netmap_rxsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
 	l = sc->rl_ldata.rl_rx_prodidx; /* next pkt to check */
 	j = netmap_idx_n2k(kring, l); /* the kring index */
 	if (netmap_no_pendintr || force_update) {
+		uint16_t slot_flags = kring->nkr_slot_flags;
+
 		for (n = kring->nr_hwavail; n < lim ; n++) {
 			struct rl_desc *cur_rx = &sc->rl_ldata.rl_rx_list[l];
 			uint32_t rxstat = le32toh(cur_rx->rl_cmdstat);
@@ -256,6 +258,7 @@ re_netmap_rxsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
 			/* XXX subtract crc */
 			total_len = (total_len < 4) ? 0 : total_len - 4;
 			kring->ring->slot[j].len = total_len;
+			kring->ring->slot[j].flags = slot_flags;
 			/*  sync was in re_newbuf() */
 			bus_dmamap_sync(sc->rl_ldata.rl_rx_mtag,
 			    rxd[l].rx_dmamap, BUS_DMASYNC_POSTREAD);
diff --git a/sys/dev/netmap/ixgbe_netmap.h b/sys/dev/netmap/ixgbe_netmap.h
index 4ac7b2ea7feb..55660ec086f6 100644
--- a/sys/dev/netmap/ixgbe_netmap.h
+++ b/sys/dev/netmap/ixgbe_netmap.h
@@ -483,6 +483,7 @@ ixgbe_netmap_rxsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
 	 */
 	if (netmap_no_pendintr || force_update) {
 		int crclen = ix_crcstrip ? 0 : 4;
+		uint16_t slot_flags = kring->nkr_slot_flags;
 
 		l = rxr->next_to_check;
 		j = netmap_idx_n2k(kring, l);
@@ -494,6 +495,7 @@ ixgbe_netmap_rxsync(struct ifnet *ifp, u_int ring_nr, int do_lock)
 			if ((staterr & IXGBE_RXD_STAT_DD) == 0)
 				break;
 			ring->slot[j].len = le16toh(curr->wb.upper.length) - crclen;
+			ring->slot[j].flags = slot_flags;
 			bus_dmamap_sync(rxr->ptag,
 			    rxr->rx_buffers[l].pmap, BUS_DMASYNC_POSTREAD);
 			j = (j == lim) ? 0 : j + 1;
diff --git a/sys/dev/netmap/netmap_kern.h b/sys/dev/netmap/netmap_kern.h
index bb0d3faae706..6b3e7ac93ce9 100644
--- a/sys/dev/netmap/netmap_kern.h
+++ b/sys/dev/netmap/netmap_kern.h
@@ -119,6 +119,10 @@ struct netmap_adapter;
  * RX rings: the next empty buffer (hwcur + hwavail + hwofs) coincides with
  * 	the next empty buffer as known by the hardware (next_to_check or so).
  * TX rings: hwcur + hwofs coincides with next_to_send
+ *
+ * For received packets, slot->flags is set to nkr_slot_flags
+ * so we can provide a proper initial value (e.g. set NS_FORWARD
+ * when operating in 'transparent' mode).
  */
 struct netmap_kring {
 	struct netmap_ring *ring;
@@ -128,6 +132,7 @@ struct netmap_kring {
 #define NKR_PENDINTR	0x1	// Pending interrupt.
 	u_int nkr_num_slots;
 
+	uint16_t	nkr_slot_flags;	/* initial value for flags */
 	int	nkr_hwofs;	/* offset between NIC and netmap ring */
 	struct netmap_adapter *na;
 	NM_SELINFO_T si;	/* poll/select wait queue */