[RFC PATCH 1/6] net: Added SetSteeringEBPF method for NetClientState.

[Andrew Melnychenko <andrew@daynix.com>]

From: Andrew <andrew@daynix.com>

For now, that method supported only by Linux TAP.
Linux TAP uses TUNSETSTEERINGEBPF ioctl.
TUNSETSTEERINGBPF was added 3 years ago.
Qemu checks if it was defined before using.

Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
---
 include/net/net.h |  2 ++
 net/tap-bsd.c     |  5 +++++
 net/tap-linux.c   | 19 +++++++++++++++++++
 net/tap-solaris.c |  5 +++++
 net/tap-stub.c    |  5 +++++
 net/tap.c         |  9 +++++++++
 net/tap_int.h     |  1 +
 7 files changed, 46 insertions(+)

diff --git a/include/net/net.h b/include/net/net.h
index 897b2d7595..d8a41fb010 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -60,6 +60,7 @@ typedef int (SetVnetBE)(NetClientState *, bool);
 typedef struct SocketReadState SocketReadState;
 typedef void (SocketReadStateFinalize)(SocketReadState *rs);
 typedef void (NetAnnounce)(NetClientState *);
+typedef bool (SetSteeringEBPF)(NetClientState *, int);
 
 typedef struct NetClientInfo {
     NetClientDriver type;
@@ -81,6 +82,7 @@ typedef struct NetClientInfo {
     SetVnetLE *set_vnet_le;
     SetVnetBE *set_vnet_be;
     NetAnnounce *announce;
+    SetSteeringEBPF *set_steering_ebpf;
 } NetClientInfo;
 
 struct NetClientState {
diff --git a/net/tap-bsd.c b/net/tap-bsd.c
index 77aaf674b1..4f64f31e98 100644
--- a/net/tap-bsd.c
+++ b/net/tap-bsd.c
@@ -259,3 +259,8 @@ int tap_fd_get_ifname(int fd, char *ifname)
 {
     return -1;
 }
+
+int tap_fd_set_steering_ebpf(int fd, int prog_fd)
+{
+    return -1;
+}
diff --git a/net/tap-linux.c b/net/tap-linux.c
index b0635e9e32..196373019f 100644
--- a/net/tap-linux.c
+++ b/net/tap-linux.c
@@ -31,6 +31,7 @@
 
 #include <net/if.h>
 #include <sys/ioctl.h>
+#include <linux/if_tun.h> /* TUNSETSTEERINGEBPF */
 
 #include "qapi/error.h"
 #include "qemu/error-report.h"
@@ -316,3 +317,21 @@ int tap_fd_get_ifname(int fd, char *ifname)
     pstrcpy(ifname, sizeof(ifr.ifr_name), ifr.ifr_name);
     return 0;
 }
+
+int tap_fd_set_steering_ebpf(int fd, int prog_fd)
+{
+#ifdef TUNSETSTEERINGEBPF
+    if (ioctl(fd, TUNSETSTEERINGEBPF, (void *) &prog_fd) != 0) {
+        error_report("Issue while setting TUNSETSTEERINGEBPF:"
+                    " %s with fd: %d, prog_fd: %d",
+                    strerror(errno), fd, prog_fd);
+
+       return -1;
+    }
+
+    return 0;
+#else
+    error_report("TUNSETSTEERINGEBPF is not supported");
+    return -1;
+#endif
+}
diff --git a/net/tap-solaris.c b/net/tap-solaris.c
index 0475a58207..d85224242b 100644
--- a/net/tap-solaris.c
+++ b/net/tap-solaris.c
@@ -255,3 +255,8 @@ int tap_fd_get_ifname(int fd, char *ifname)
 {
     return -1;
 }
+
+int tap_fd_set_steering_ebpf(int fd, int prog_fd)
+{
+    return -1;
+}
diff --git a/net/tap-stub.c b/net/tap-stub.c
index de525a2e69..a0fa25804b 100644
--- a/net/tap-stub.c
+++ b/net/tap-stub.c
@@ -85,3 +85,8 @@ int tap_fd_get_ifname(int fd, char *ifname)
 {
     return -1;
 }
+
+int tap_fd_set_steering_ebpf(int fd, int prog_fd)
+{
+    return -1;
+}
diff --git a/net/tap.c b/net/tap.c
index c46ff66184..81f50017bd 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -337,6 +337,14 @@ static void tap_poll(NetClientState *nc, bool enable)
     tap_write_poll(s, enable);
 }
 
+static bool tap_set_steering_ebpf(NetClientState *nc, int prog_fd)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    assert(nc->info->type == NET_CLIENT_DRIVER_TAP);
+
+    return tap_fd_set_steering_ebpf(s->fd, prog_fd) == 0;
+}
+
 int tap_get_fd(NetClientState *nc)
 {
     TAPState *s = DO_UPCAST(TAPState, nc, nc);
@@ -362,6 +370,7 @@ static NetClientInfo net_tap_info = {
     .set_vnet_hdr_len = tap_set_vnet_hdr_len,
     .set_vnet_le = tap_set_vnet_le,
     .set_vnet_be = tap_set_vnet_be,
+    .set_steering_ebpf = tap_set_steering_ebpf,
 };
 
 static TAPState *net_tap_fd_init(NetClientState *peer,
diff --git a/net/tap_int.h b/net/tap_int.h
index 225a49ea48..547f8a5a28 100644
--- a/net/tap_int.h
+++ b/net/tap_int.h
@@ -44,5 +44,6 @@ int tap_fd_set_vnet_be(int fd, int vnet_is_be);
 int tap_fd_enable(int fd);
 int tap_fd_disable(int fd);
 int tap_fd_get_ifname(int fd, char *ifname);
+int tap_fd_set_steering_ebpf(int fd, int prog_fd);
 
 #endif /* NET_TAP_INT_H */
-- 
2.28.0