trafgen: take advantage of PACKET_QDISC_BYPASS sock option

Since Linux 3.14, the kernel supports a socket option PACKET_QDISC_BYPASS,
which trafgen enables by default. That allow us to bypass the kernels
normal qdisc (traffic control) layer.

An option -q, --qdisc-path is added to allow enabling the qdisc path
explicity, useful for testing purposes.

This will be avail in kernels >= 3.14 via
 commit d346a3fae3 (packet: introduce PACKET_QDISC_BYPASS socket option).

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/sock.h b/sock.h
index 75be501..0e680ef 100644
--- a/sock.h
+++ b/sock.h
@@ -7,6 +7,7 @@ extern int pf_tx_socket(void);
 extern void set_nonblocking(int fd);
 extern int set_nonblocking_sloppy(int fd);
 extern int set_reuseaddr(int fd);
+extern void set_sock_qdisc_bypass(int fd, int verbose);
 extern void set_sock_prio(int fd, int prio);
 extern void set_tcp_nodelay(int fd);
 extern void set_socket_keepalive(int fd);