packet_mmap: expose hw packet timestamps to network packet capture utilities
This patch adds a setting, PACKET_TIMESTAMP, to specify the packet
timestamp source that is exported to capture utilities like tcpdump by
packet_mmap.
PACKET_TIMESTAMP accepts the same integer bit field as
SO_TIMESTAMPING. However, only the SOF_TIMESTAMPING_SYS_HARDWARE and
SOF_TIMESTAMPING_RAW_HARDWARE values are currently recognized by
PACKET_TIMESTAMP. SOF_TIMESTAMPING_SYS_HARDWARE takes precedence over
SOF_TIMESTAMPING_RAW_HARDWARE if both bits are set.
If PACKET_TIMESTAMP is not set, a software timestamp generated inside
the networking stack is used (the behavior before this setting was
added).
Signed-off-by: Scott McMillan <scott.a.mcmillan@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/if_packet.h b/include/linux/if_packet.h
index 6ac23ef..72bfa5a 100644
--- a/include/linux/if_packet.h
+++ b/include/linux/if_packet.h
@@ -48,6 +48,7 @@
#define PACKET_LOSS 14
#define PACKET_VNET_HDR 15
#define PACKET_TX_TIMESTAMP 16
+#define PACKET_TIMESTAMP 17
struct tpacket_stats {
unsigned int tp_packets;