net: Added SetSteeringEBPF method for NetClientState.

For now, that method supported only by Linux TAP.
Linux TAP uses TUNSETSTEERINGEBPF ioctl.

Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

include/net/net.h

@@ -61,6 +61,7 @@ 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;
@@ -82,6 +83,7 @@ typedef struct NetClientInfo {
     SetVnetLE *set_vnet_le;
     SetVnetBE *set_vnet_be;
     NetAnnounce *announce;
+    SetSteeringEBPF *set_steering_ebpf;
 } NetClientInfo;
 
 struct NetClientState {

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;
+}

net/tap-linux.c

@@ -316,3 +316,16 @@ 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)
+{
+    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;
+}

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;
+}

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;
+}

net/tap.c

@@ -347,6 +347,14 @@ 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);
@@ -372,6 +380,7 @@ 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,

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 */