ring: implement setup of tpacket v3 ring

Implement ring setup routines and structures for TPACKET_V3.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>

3 files changed, 30 insertions, 3 deletions

diff --git a/ring.h b/ring.h
index f618a35..7590223 100644
--- a/ring.h
+++ b/ring.h
@@ -45,6 +45,7 @@ struct ring {
 	union {
 		struct tpacket_req layout;
 		struct tpacket_req3 layout3;
+		uint8_t raw;
 	};
 };
 
@@ -113,6 +114,18 @@ static inline void __set_sockopt_tpacket(int sock, int val)
 		panic("Cannot set tpacketv2!\n");
 }
 
+static inline int __get_sockopt_tpacket(int sock)
+{
+	int val, ret;
+	socklen_t len = sizeof(val);
+
+	ret = getsockopt(sock, SOL_PACKET, PACKET_VERSION, &val, &len);
+	if (ret)
+		panic("Cannot set tpacketv2!\n");
+
+	return val;
+}
+
 static inline void set_sockopt_tpacket_v2(int sock)
 {
 	__set_sockopt_tpacket(sock, TPACKET_V2);
@@ -123,4 +136,9 @@ static inline void set_sockopt_tpacket_v3(int sock)
 	__set_sockopt_tpacket(sock, TPACKET_V3);
 }
 
+static inline int get_sockopt_tpacket(int sock)
+{
+	return __get_sockopt_tpacket(sock);
+}
+
 #endif /* RING_H */
diff --git a/ring_rx.c b/ring_rx.c
index fc735cc..a3d8e4d 100644
--- a/ring_rx.c
+++ b/ring_rx.c
@@ -57,6 +57,10 @@ void setup_rx_ring_layout(int sock, struct ring *ring, unsigned int size,
 			     sizeof(struct tpacket_req) !=
 			     offsetof(struct tpacket_req3, tp_retire_blk_tov));
 
+		ring->layout3.tp_retire_blk_tov = 0;
+		ring->layout3.tp_sizeof_priv = 0;
+		ring->layout3.tp_feature_req_word = 0;
+
 		set_sockopt_tpacket_v3(sock);
 	} else {
 		set_sockopt_tpacket_v2(sock);
@@ -68,10 +72,11 @@ void setup_rx_ring_layout(int sock, struct ring *ring, unsigned int size,
 void create_rx_ring(int sock, struct ring *ring, int verbose)
 {
 	int ret;
+	bool v3 = get_sockopt_tpacket(sock) == TPACKET_V3;
 
 retry:
-	ret = setsockopt(sock, SOL_PACKET, PACKET_RX_RING, &ring->layout,
-			 sizeof(ring->layout));
+	ret = setsockopt(sock, SOL_PACKET, PACKET_RX_RING, &ring->raw,
+			 v3 ? sizeof(ring->layout3) : sizeof(ring->layout));
 	if (errno == ENOMEM && ring->layout.tp_block_nr > 1) {
 		ring->layout.tp_block_nr >>= 1;
 		ring->layout.tp_frame_nr = ring->layout.tp_block_size / 
@@ -79,7 +84,6 @@ retry:
 					   ring->layout.tp_block_nr;
 		goto retry;
 	}
-
 	if (ret < 0)
 		panic("Cannot allocate RX_RING!\n");
 
diff --git a/ring_rx.h b/ring_rx.h
index b1114a6..0a2701f 100644
--- a/ring_rx.h
+++ b/ring_rx.h
@@ -23,6 +23,11 @@ static inline int user_may_pull_from_rx(struct tpacket2_hdr *hdr)
 	return ((hdr->tp_status & TP_STATUS_USER) == TP_STATUS_USER);
 }
 
+static inline int user_may_pull_from_rx_block(struct block_desc *pbd)
+{
+	return ((pbd->h1.block_status & TP_STATUS_USER) == TP_STATUS_USER);
+}
+
 static inline void kernel_may_pull_from_rx(struct tpacket2_hdr *hdr)
 {
 	hdr->tp_status = TP_STATUS_KERNEL;