cls_bpf: allow attaching programs loaded for specific device

If TC program is loaded with skip_sw flag, we should allow
the device-specific programs to be accepted.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

kernel/bpf/syscall.c

@@ -1115,6 +1115,7 @@ struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
 		trace_bpf_prog_get_type(prog);
 	return prog;
 }
+EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
 
 /* last field in 'union bpf_attr' used by this command */
 #define	BPF_PROG_LOAD_LAST_FIELD prog_target_ifindex

net/sched/cls_bpf.c

@@ -374,7 +374,7 @@ static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
 }
 
 static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
-				 const struct tcf_proto *tp)
+				 u32 gen_flags, const struct tcf_proto *tp)
 {
 	struct bpf_prog *fp;
 	char *name = NULL;
@@ -382,7 +382,11 @@ static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
 
 	bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
 
-	fp = bpf_prog_get_type(bpf_fd, BPF_PROG_TYPE_SCHED_CLS);
+	if (gen_flags & TCA_CLS_FLAGS_SKIP_SW)
+		fp = bpf_prog_get_type_dev(bpf_fd, BPF_PROG_TYPE_SCHED_CLS,
+					   qdisc_dev(tp->q));
+	else
+		fp = bpf_prog_get_type(bpf_fd, BPF_PROG_TYPE_SCHED_CLS);
 	if (IS_ERR(fp))
 		return PTR_ERR(fp);
 
@@ -440,7 +444,7 @@ static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
 	prog->gen_flags = gen_flags;
 
 	ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
-		       cls_bpf_prog_from_efd(tb, prog, tp);
+		       cls_bpf_prog_from_efd(tb, prog, gen_flags, tp);
 	if (ret < 0)
 		return ret;