Merge branch 'bpf-add-offload-as-a-first-class-citizen'

Jakub Kicinski says:

====================
bpf: add offload as a first class citizen

This series is my stab at what was discussed at a recent IOvisor
bi-weekly call.  The idea is to make the device translator run at
the program load time.  This makes the offload more explicit to
the user space.  It also makes it easy for the device translator
to insert information into the original verifier log.

v2:
 - include linux/bug.h instead of asm/bug.h;
 - rebased on top of Craig's verifier fix (no changes, the last patch
   just removes more code now).  I checked the set doesn't conflict
   with Jiri's, Josef's or Roman's patches, but missed Craig's fix :(
v1:
 - rename the ifindex member on load;
 - improve commit messages;
 - split nfp patches more.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 46 insertions, 6 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 323be2473c4b..416d70cdfc76 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -824,7 +824,10 @@ static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
 	if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type])
 		return -EINVAL;
 
-	prog->aux->ops = bpf_prog_types[type];
+	if (!bpf_prog_is_dev_bound(prog->aux))
+		prog->aux->ops = bpf_prog_types[type];
+	else
+		prog->aux->ops = &bpf_offload_prog_ops;
 	prog->type = type;
 	return 0;
 }
@@ -1054,7 +1057,22 @@ struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
 }
 EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
 
-static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *type)
+static bool bpf_prog_can_attach(struct bpf_prog *prog,
+				enum bpf_prog_type *attach_type,
+				struct net_device *netdev)
+{
+	struct bpf_dev_offload *offload = prog->aux->offload;
+
+	if (prog->type != *attach_type)
+		return false;
+	if (offload && offload->netdev != netdev)
+		return false;
+
+	return true;
+}
+
+static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
+				       struct net_device *netdev)
 {
 	struct fd f = fdget(ufd);
 	struct bpf_prog *prog;
@@ -1062,7 +1080,7 @@ static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *type)
 	prog = ____bpf_prog_get(f);
 	if (IS_ERR(prog))
 		return prog;
-	if (type && prog->type != *type) {
+	if (attach_type && !bpf_prog_can_attach(prog, attach_type, netdev)) {
 		prog = ERR_PTR(-EINVAL);
 		goto out;
 	}
@@ -1075,12 +1093,12 @@ out:
 
 struct bpf_prog *bpf_prog_get(u32 ufd)
 {
-	return __bpf_prog_get(ufd, NULL);
+	return __bpf_prog_get(ufd, NULL, NULL);
 }
 
 struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type)
 {
-	struct bpf_prog *prog = __bpf_prog_get(ufd, &type);
+	struct bpf_prog *prog = __bpf_prog_get(ufd, &type, NULL);
 
 	if (!IS_ERR(prog))
 		trace_bpf_prog_get_type(prog);
@@ -1088,8 +1106,19 @@ struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type)
 }
 EXPORT_SYMBOL_GPL(bpf_prog_get_type);
 
+struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
+				       struct net_device *netdev)
+{
+	struct bpf_prog *prog = __bpf_prog_get(ufd, &type, netdev);
+
+	if (!IS_ERR(prog))
+		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_name
+#define	BPF_PROG_LOAD_LAST_FIELD prog_target_ifindex
 
 static int bpf_prog_load(union bpf_attr *attr)
 {
@@ -1152,6 +1181,12 @@ static int bpf_prog_load(union bpf_attr *attr)
 	atomic_set(&prog->aux->refcnt, 1);
 	prog->gpl_compatible = is_gpl ? 1 : 0;
 
+	if (attr->prog_target_ifindex) {
+		err = bpf_prog_offload_init(prog, attr);
+		if (err)
+			goto free_prog;
+	}
+
 	/* find program type: socket_filter vs tracing_filter */
 	err = find_prog_type(type, prog);
 	if (err < 0)
@@ -1583,6 +1618,11 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
 			return -EFAULT;
 	}
 
+	if (bpf_prog_is_dev_bound(prog->aux)) {
+		info.status |= BPF_PROG_STATUS_DEV_BOUND;
+		info.ifindex = bpf_prog_offload_ifindex(prog);
+	}
+
 done:
 	if (copy_to_user(uinfo, &info, info_len) ||
 	    put_user(info_len, &uattr->info.info_len))