Merge branch 'bpf-offload-report-dev'

Jakub Kicinski says:

====================
This series is a redo of reporting offload device information to
user space after the first attempt did not take into account name
spaces.  As requested by Kirill offloads are now protected by an
r/w sem.  This allows us to remove the workqueue and free the
offload state fully when device is removed (suggested by Alexei).

Net namespace is reported with a device/inode pair.

The accompanying bpftool support is placed in common code because
maps will have very similar info.  Note that the UAPI information
can't be nicely encapsulated into a struct, because in case we
need to grow the device information the new fields will have to
be added at the end of struct bpf_prog_info, we can't grow
structures in the middle of bpf_prog_info.

v3:
 - use dev_get_by_index();
 - redo ns code (new patch 6).
v2:
 - rework the locking in patch 1 (use RCU instead of locking
   dependencies);
 - grab RTNL for a short time in patch 6;
 - minor update to the test in patch 8.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

drivers/net/ethernet/netronome/nfp/bpf/main.h

@@ -238,7 +238,7 @@ struct nfp_bpf_vnic {
 
 int nfp_bpf_jit(struct nfp_prog *prog);
 
-extern const struct bpf_ext_analyzer_ops nfp_bpf_analyzer_ops;
+extern const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops;
 
 struct netdev_bpf;
 struct nfp_app;

drivers/net/ethernet/netronome/nfp/bpf/verifier.c

@@ -260,6 +260,6 @@ nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx)
 	return 0;
 }
 
-const struct bpf_ext_analyzer_ops nfp_bpf_analyzer_ops = {
+const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops = {
 	.insn_hook = nfp_verify_insn,
 };

drivers/net/netdevsim/bpf.c

@@ -66,7 +66,7 @@ nsim_bpf_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn)
 	return 0;
 }
 
-static const struct bpf_ext_analyzer_ops nsim_bpf_analyzer_ops = {
+static const struct bpf_prog_offload_ops nsim_bpf_analyzer_ops = {
 	.insn_hook = nsim_bpf_verify_insn,
 };
 

fs/nsfs.c

@@ -103,14 +103,14 @@ static void *__ns_get_path(struct path *path, struct ns_common *ns)
 	goto got_it;
 }
 
-void *ns_get_path(struct path *path, struct task_struct *task,
-			const struct proc_ns_operations *ns_ops)
+void *ns_get_path_cb(struct path *path, ns_get_path_helper_t *ns_get_cb,
+		     void *private_data)
 {
 	struct ns_common *ns;
 	void *ret;
 
 again:
-	ns = ns_ops->get(task);
+	ns = ns_get_cb(private_data);
 	if (!ns)
 		return ERR_PTR(-ENOENT);
 
@@ -120,6 +120,29 @@ void *ns_get_path(struct path *path, struct task_struct *task,
 	return ret;
 }
 
+struct ns_get_path_task_args {
+	const struct proc_ns_operations *ns_ops;
+	struct task_struct *task;
+};
+
+static struct ns_common *ns_get_path_task(void *private_data)
+{
+	struct ns_get_path_task_args *args = private_data;
+
+	return args->ns_ops->get(args->task);
+}
+
+void *ns_get_path(struct path *path, struct task_struct *task,
+		  const struct proc_ns_operations *ns_ops)
+{
+	struct ns_get_path_task_args args = {
+		.ns_ops	= ns_ops,
+		.task	= task,
+	};
+
+	return ns_get_path_cb(path, ns_get_path_task, &args);
+}
+
 int open_related_ns(struct ns_common *ns,
 		   struct ns_common *(*get_ns)(struct ns_common *ns))
 {

include/linux/bpf.h

@@ -17,6 +17,7 @@
 #include <linux/numa.h>
 #include <linux/wait.h>
 
+struct bpf_verifier_env;
 struct perf_event;
 struct bpf_prog;
 struct bpf_map;
@@ -184,14 +185,18 @@ struct bpf_verifier_ops {
 				  struct bpf_prog *prog, u32 *target_size);
 };
 
+struct bpf_prog_offload_ops {
+	int (*insn_hook)(struct bpf_verifier_env *env,
+			 int insn_idx, int prev_insn_idx);
+};
+
 struct bpf_dev_offload {
 	struct bpf_prog		*prog;
 	struct net_device	*netdev;
 	void			*dev_priv;
 	struct list_head	offloads;
 	bool			dev_state;
-	bool			verifier_running;
-	wait_queue_head_t	verifier_done;
+	const struct bpf_prog_offload_ops *dev_ops;
 };
 
 struct bpf_prog_aux {
@@ -201,6 +206,7 @@ struct bpf_prog_aux {
 	u32 stack_depth;
 	u32 id;
 	u32 func_cnt;
+	bool offload_requested;
 	struct bpf_prog **func;
 	void *jit_data; /* JIT specific data. arch dependent */
 	struct latch_tree_node ksym_tnode;
@@ -351,6 +357,8 @@ void bpf_prog_put(struct bpf_prog *prog);
 int __bpf_prog_charge(struct user_struct *user, u32 pages);
 void __bpf_prog_uncharge(struct user_struct *user, u32 pages);
 
+void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock);
+
 struct bpf_map *bpf_map_get_with_uref(u32 ufd);
 struct bpf_map *__bpf_map_get(struct fd f);
 struct bpf_map * __must_check bpf_map_inc(struct bpf_map *map, bool uref);
@@ -523,13 +531,15 @@ static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
 
 int bpf_prog_offload_compile(struct bpf_prog *prog);
 void bpf_prog_offload_destroy(struct bpf_prog *prog);
+int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
+			       struct bpf_prog *prog);
 
 #if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL)
 int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr);
 
 static inline bool bpf_prog_is_dev_bound(struct bpf_prog_aux *aux)
 {
-	return aux->offload;
+	return aux->offload_requested;
 }
 #else
 static inline int bpf_prog_offload_init(struct bpf_prog *prog,

include/linux/bpf_verifier.h

@@ -166,12 +166,6 @@ static inline bool bpf_verifier_log_full(const struct bpf_verifer_log *log)
 	return log->len_used >= log->len_total - 1;
 }
 
-struct bpf_verifier_env;
-struct bpf_ext_analyzer_ops {
-	int (*insn_hook)(struct bpf_verifier_env *env,
-			 int insn_idx, int prev_insn_idx);
-};
-
 #define BPF_MAX_SUBPROGS 256
 
 /* single container for all structs
@@ -185,7 +179,6 @@ struct bpf_verifier_env {
 	bool strict_alignment;		/* perform strict pointer alignment checks */
 	struct bpf_verifier_state *cur_state; /* current verifier state */
 	struct bpf_verifier_state_list **explored_states; /* search pruning optimization */
-	const struct bpf_ext_analyzer_ops *dev_ops; /* device analyzer ops */
 	struct bpf_map *used_maps[MAX_USED_MAPS]; /* array of map's used by eBPF program */
 	u32 used_map_cnt;		/* number of used maps */
 	u32 id_gen;			/* used to generate unique reg IDs */
@@ -206,13 +199,8 @@ static inline struct bpf_reg_state *cur_regs(struct bpf_verifier_env *env)
 	return cur->frame[cur->curframe]->regs;
 }
 
-#if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL)
 int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env);
-#else
-static inline int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env)
-{
-	return -EOPNOTSUPP;
-}
-#endif
+int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
+				 int insn_idx, int prev_insn_idx);
 
 #endif /* _LINUX_BPF_VERIFIER_H */

include/linux/netdevice.h

@@ -804,7 +804,7 @@ enum bpf_netdev_command {
 	BPF_OFFLOAD_DESTROY,
 };
 
-struct bpf_ext_analyzer_ops;
+struct bpf_prog_offload_ops;
 struct netlink_ext_ack;
 
 struct netdev_bpf {
@@ -826,7 +826,7 @@ struct netdev_bpf {
 		/* BPF_OFFLOAD_VERIFIER_PREP */
 		struct {
 			struct bpf_prog *prog;
-			const struct bpf_ext_analyzer_ops *ops; /* callee set */
+			const struct bpf_prog_offload_ops *ops; /* callee set */
 		} verifier;
 		/* BPF_OFFLOAD_TRANSLATE, BPF_OFFLOAD_DESTROY */
 		struct {

include/linux/proc_ns.h

@@ -78,6 +78,9 @@ extern struct file *proc_ns_fget(int fd);
 #define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private)
 extern void *ns_get_path(struct path *path, struct task_struct *task,
 			const struct proc_ns_operations *ns_ops);
+typedef struct ns_common *ns_get_path_helper_t(void *);
+extern void *ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb,
+			    void *private_data);
 
 extern int ns_get_name(char *buf, size_t size, struct task_struct *task,
 			const struct proc_ns_operations *ns_ops);

include/uapi/linux/bpf.h

@@ -921,6 +921,9 @@ struct bpf_prog_info {
 	__u32 nr_map_ids;
 	__aligned_u64 map_ids;
 	char name[BPF_OBJ_NAME_LEN];
+	__u32 ifindex;
+	__u64 netns_dev;
+	__u64 netns_ino;
 } __attribute__((aligned(8)));
 
 struct bpf_map_info {

kernel/bpf/offload.c

@@ -16,17 +16,22 @@
 #include <linux/bpf.h>
 #include <linux/bpf_verifier.h>
 #include <linux/bug.h>
+#include <linux/kdev_t.h>
 #include <linux/list.h>
 #include <linux/netdevice.h>
 #include <linux/printk.h>
+#include <linux/proc_ns.h>
 #include <linux/rtnetlink.h>
+#include <linux/rwsem.h>
 
-/* protected by RTNL */
+/* Protects bpf_prog_offload_devs and offload members of all progs.
+ * RTNL lock cannot be taken when holding this lock.
+ */
+static DECLARE_RWSEM(bpf_devs_lock);
 static LIST_HEAD(bpf_prog_offload_devs);
 
 int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
 {
-	struct net *net = current->nsproxy->net_ns;
 	struct bpf_dev_offload *offload;
 
 	if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS &&
@@ -41,32 +46,40 @@ int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
 		return -ENOMEM;
 
 	offload->prog = prog;
-	init_waitqueue_head(&offload->verifier_done);
 
-	rtnl_lock();
-	offload->netdev = __dev_get_by_index(net, attr->prog_ifindex);
-	if (!offload->netdev) {
-		rtnl_unlock();
-		kfree(offload);
-		return -EINVAL;
-	}
+	offload->netdev = dev_get_by_index(current->nsproxy->net_ns,
+					   attr->prog_ifindex);
+	if (!offload->netdev)
+		goto err_free;
 
+	down_write(&bpf_devs_lock);
+	if (offload->netdev->reg_state != NETREG_REGISTERED)
+		goto err_unlock;
 	prog->aux->offload = offload;
 	list_add_tail(&offload->offloads, &bpf_prog_offload_devs);
-	rtnl_unlock();
+	dev_put(offload->netdev);
+	up_write(&bpf_devs_lock);
 
 	return 0;
+err_unlock:
+	up_write(&bpf_devs_lock);
+	dev_put(offload->netdev);
+err_free:
+	kfree(offload);
+	return -EINVAL;
 }
 
 static int __bpf_offload_ndo(struct bpf_prog *prog, enum bpf_netdev_command cmd,
 			     struct netdev_bpf *data)
 {
-	struct net_device *netdev = prog->aux->offload->netdev;
+	struct bpf_dev_offload *offload = prog->aux->offload;
+	struct net_device *netdev;
 
 	ASSERT_RTNL();
 
-	if (!netdev)
+	if (!offload)
 		return -ENODEV;
+	netdev = offload->netdev;
 	if (!netdev->netdev_ops->ndo_bpf)
 		return -EOPNOTSUPP;
 
@@ -87,62 +100,63 @@ int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env)
 	if (err)
 		goto exit_unlock;
 
-	env->dev_ops = data.verifier.ops;
-
+	env->prog->aux->offload->dev_ops = data.verifier.ops;
 	env->prog->aux->offload->dev_state = true;
-	env->prog->aux->offload->verifier_running = true;
 exit_unlock:
 	rtnl_unlock();
 	return err;
 }
 
+int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
+				 int insn_idx, int prev_insn_idx)
+{
+	struct bpf_dev_offload *offload;
+	int ret = -ENODEV;
+
+	down_read(&bpf_devs_lock);
+	offload = env->prog->aux->offload;
+	if (offload)
+		ret = offload->dev_ops->insn_hook(env, insn_idx, prev_insn_idx);
+	up_read(&bpf_devs_lock);
+
+	return ret;
+}
+
 static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
 {
 	struct bpf_dev_offload *offload = prog->aux->offload;
 	struct netdev_bpf data = {};
 
-	/* Caution - if netdev is destroyed before the program, this function
-	 * will be called twice.
-	 */
-
 	data.offload.prog = prog;
 
-	if (offload->verifier_running)
-		wait_event(offload->verifier_done, !offload->verifier_running);
-
 	if (offload->dev_state)
 		WARN_ON(__bpf_offload_ndo(prog, BPF_OFFLOAD_DESTROY, &data));
 
-	offload->dev_state = false;
+	/* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */
+	bpf_prog_free_id(prog, true);
+
 	list_del_init(&offload->offloads);
-	offload->netdev = NULL;
+	kfree(offload);
+	prog->aux->offload = NULL;
 }
 
 void bpf_prog_offload_destroy(struct bpf_prog *prog)
 {
-	struct bpf_dev_offload *offload = prog->aux->offload;
-
-	offload->verifier_running = false;
-	wake_up(&offload->verifier_done);
-
 	rtnl_lock();
+	down_write(&bpf_devs_lock);
+	if (prog->aux->offload)
 		__bpf_prog_offload_destroy(prog);
+	up_write(&bpf_devs_lock);
 	rtnl_unlock();
-
-	kfree(offload);
 }
 
 static int bpf_prog_offload_translate(struct bpf_prog *prog)
 {
-	struct bpf_dev_offload *offload = prog->aux->offload;
 	struct netdev_bpf data = {};
 	int ret;
 
 	data.offload.prog = prog;
 
-	offload->verifier_running = false;
-	wake_up(&offload->verifier_done);
-
 	rtnl_lock();
 	ret = __bpf_offload_ndo(prog, BPF_OFFLOAD_TRANSLATE, &data);
 	rtnl_unlock();
@@ -164,6 +178,63 @@ int bpf_prog_offload_compile(struct bpf_prog *prog)
 	return bpf_prog_offload_translate(prog);
 }
 
+struct ns_get_path_bpf_prog_args {
+	struct bpf_prog *prog;
+	struct bpf_prog_info *info;
+};
+
+static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data)
+{
+	struct ns_get_path_bpf_prog_args *args = private_data;
+	struct bpf_prog_aux *aux = args->prog->aux;
+	struct ns_common *ns;
+	struct net *net;
+
+	rtnl_lock();
+	down_read(&bpf_devs_lock);
+
+	if (aux->offload) {
+		args->info->ifindex = aux->offload->netdev->ifindex;
+		net = dev_net(aux->offload->netdev);
+		get_net(net);
+		ns = &net->ns;
+	} else {
+		args->info->ifindex = 0;
+		ns = NULL;
+	}
+
+	up_read(&bpf_devs_lock);
+	rtnl_unlock();
+
+	return ns;
+}
+
+int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
+			       struct bpf_prog *prog)
+{
+	struct ns_get_path_bpf_prog_args args = {
+		.prog	= prog,
+		.info	= info,
+	};
+	struct inode *ns_inode;
+	struct path ns_path;
+	void *res;
+
+	res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
+	if (IS_ERR(res)) {
+		if (!info->ifindex)
+			return -ENODEV;
+		return PTR_ERR(res);
+	}
+
+	ns_inode = ns_path.dentry->d_inode;
+	info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
+	info->netns_ino = ns_inode->i_ino;
+	path_put(&ns_path);
+
+	return 0;
+}
+
 const struct bpf_prog_ops bpf_offload_prog_ops = {
 };
 
@@ -181,11 +252,13 @@ static int bpf_offload_notification(struct notifier_block *notifier,
 		if (netdev->reg_state != NETREG_UNREGISTERING)
 			break;
 
+		down_write(&bpf_devs_lock);
 		list_for_each_entry_safe(offload, tmp, &bpf_prog_offload_devs,
 					 offloads) {
 			if (offload->netdev == netdev)
 				__bpf_prog_offload_destroy(offload->prog);
 		}
+		up_write(&bpf_devs_lock);
 		break;
 	default:
 		break;

kernel/bpf/syscall.c

@@ -905,9 +905,13 @@ static int bpf_prog_alloc_id(struct bpf_prog *prog)
 	return id > 0 ? 0 : id;
 }
 
-static void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
+void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
 {
-	/* cBPF to eBPF migrations are currently not in the idr store. */
+	/* cBPF to eBPF migrations are currently not in the idr store.
+	 * Offloaded programs are removed from the store when their device
+	 * disappears - even if someone grabs an fd to them they are unusable,
+	 * simply waiting for refcnt to drop to be freed.
+	 */
 	if (!prog->aux->id)
 		return;
 
@@ -917,6 +921,7 @@ static void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
 		__acquire(&prog_idr_lock);
 
 	idr_remove(&prog_idr, prog->aux->id);
+	prog->aux->id = 0;
 
 	if (do_idr_lock)
 		spin_unlock_bh(&prog_idr_lock);
@@ -1157,6 +1162,8 @@ static int bpf_prog_load(union bpf_attr *attr)
 	if (!prog)
 		return -ENOMEM;
 
+	prog->aux->offload_requested = !!attr->prog_ifindex;
+
 	err = security_bpf_prog_alloc(prog->aux);
 	if (err)
 		goto free_prog_nouncharge;
@@ -1178,7 +1185,7 @@ 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_ifindex) {
+	if (bpf_prog_is_dev_bound(prog->aux)) {
 		err = bpf_prog_offload_init(prog, attr);
 		if (err)
 			goto free_prog;
@@ -1700,6 +1707,12 @@ static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
 			return -EFAULT;
 	}
 
+	if (bpf_prog_is_dev_bound(prog->aux)) {
+		err = bpf_prog_offload_info_fill(&info, prog);
+		if (err)
+			return err;
+	}
+
 done:
 	if (copy_to_user(uinfo, &info, info_len) ||
 	    put_user(info_len, &uattr->info.info_len))

kernel/bpf/verifier.c

@@ -4438,15 +4438,6 @@ static int is_state_visited(struct bpf_verifier_env *env, int insn_idx)
 	return 0;
 }
 
-static int ext_analyzer_insn_hook(struct bpf_verifier_env *env,
-				  int insn_idx, int prev_insn_idx)
-{
-	if (env->dev_ops && env->dev_ops->insn_hook)
-		return env->dev_ops->insn_hook(env, insn_idx, prev_insn_idx);
-
-	return 0;
-}
-
 static int do_check(struct bpf_verifier_env *env)
 {
 	struct bpf_verifier_state *state;
@@ -4531,9 +4522,12 @@ static int do_check(struct bpf_verifier_env *env)
 			print_bpf_insn(&cbs, env, insn, env->allow_ptr_leaks);
 		}
 
-		err = ext_analyzer_insn_hook(env, insn_idx, prev_insn_idx);
+		if (bpf_prog_is_dev_bound(env->prog->aux)) {
+			err = bpf_prog_offload_verify_insn(env, insn_idx,
+							   prev_insn_idx);
 			if (err)
 				return err;
+		}
 
 		regs = cur_regs(env);
 		env->insn_aux_data[insn_idx].seen = true;
@@ -5463,7 +5457,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr)
 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS))
 		env->strict_alignment = true;
 
-	if (env->prog->aux->offload) {
+	if (bpf_prog_is_dev_bound(env->prog->aux)) {
 		ret = bpf_prog_offload_verifier_prep(env);
 		if (ret)
 			goto err_unlock;

tools/bpf/bpftool/common.c

@@ -44,7 +44,9 @@
 #include <unistd.h>
 #include <linux/limits.h>
 #include <linux/magic.h>
+#include <net/if.h>
 #include <sys/mount.h>
+#include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/vfs.h>
 
@@ -412,3 +414,53 @@ void delete_pinned_obj_table(struct pinned_obj_table *tab)
 		free(obj);
 	}
 }
+
+static char *
+ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
+{
+	struct stat st;
+	int err;
+
+	err = stat("/proc/self/ns/net", &st);
+	if (err) {
+		p_err("Can't stat /proc/self: %s", strerror(errno));
+		return NULL;
+	}
+
+	if (st.st_dev != ns_dev || st.st_ino != ns_ino)
+		return NULL;
+
+	return if_indextoname(ifindex, buf);
+}
+
+void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
+{
+	char name[IF_NAMESIZE];
+
+	if (!ifindex)
+		return;
+
+	printf(" dev ");
+	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
+		printf("%s", name);
+	else
+		printf("ifindex %u ns_dev %llu ns_ino %llu",
+		       ifindex, ns_dev, ns_inode);
+}
+
+void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode)
+{
+	char name[IF_NAMESIZE];
+
+	if (!ifindex)
+		return;
+
+	jsonw_name(json_wtr, "dev");
+	jsonw_start_object(json_wtr);
+	jsonw_uint_field(json_wtr, "ifindex", ifindex);
+	jsonw_uint_field(json_wtr, "ns_dev", ns_dev);
+	jsonw_uint_field(json_wtr, "ns_inode", ns_inode);
+	if (ifindex_to_name_ns(ifindex, ns_dev, ns_inode, name))
+		jsonw_string_field(json_wtr, "ifname", name);
+	jsonw_end_object(json_wtr);
+}

tools/bpf/bpftool/main.h

@@ -96,6 +96,8 @@ struct pinned_obj {
 int build_pinned_obj_table(struct pinned_obj_table *table,
 			   enum bpf_obj_type type);
 void delete_pinned_obj_table(struct pinned_obj_table *tab);
+void print_dev_plain(__u32 ifindex, __u64 ns_dev, __u64 ns_inode);
+void print_dev_json(__u32 ifindex, __u64 ns_dev, __u64 ns_inode);
 
 struct cmd {
 	const char *cmd;

tools/bpf/bpftool/prog.c

@@ -230,6 +230,8 @@ static void print_prog_json(struct bpf_prog_info *info, int fd)
 		     info->tag[0], info->tag[1], info->tag[2], info->tag[3],
 		     info->tag[4], info->tag[5], info->tag[6], info->tag[7]);
 
+	print_dev_json(info->ifindex, info->netns_dev, info->netns_ino);
+
 	if (info->load_time) {
 		char buf[32];
 
@@ -287,6 +289,7 @@ static void print_prog_plain(struct bpf_prog_info *info, int fd)
 
 	printf("tag ");
 	fprint_hex(stdout, info->tag, BPF_TAG_SIZE, "");
+	print_dev_plain(info->ifindex, info->netns_dev, info->netns_ino);
 	printf("\n");
 
 	if (info->load_time) {

tools/include/uapi/linux/bpf.h

@@ -921,6 +921,9 @@ struct bpf_prog_info {
 	__u32 nr_map_ids;
 	__aligned_u64 map_ids;
 	char name[BPF_OBJ_NAME_LEN];
+	__u32 ifindex;
+	__u64 netns_dev;
+	__u64 netns_ino;
 } __attribute__((aligned(8)));
 
 struct bpf_map_info {

tools/testing/selftests/bpf/test_offload.py

@@ -18,6 +18,8 @@ import argparse
 import json
 import os
 import pprint
+import random
+import string
 import subprocess
 import time
 
@@ -27,6 +29,7 @@ bpf_test_dir = os.path.dirname(os.path.realpath(__file__))
 pp = pprint.PrettyPrinter()
 devs = [] # devices we created for clean up
 files = [] # files to be removed
+netns = [] # net namespaces to be removed
 
 def log_get_sec(level=0):
     return "*" * (log_level + level)
@@ -128,22 +131,25 @@ def rm(f):
     if f in files:
         files.remove(f)
 
-def tool(name, args, flags, JSON=True, fail=True):
+def tool(name, args, flags, JSON=True, ns="", fail=True):
     params = ""
     if JSON:
         params += "%s " % (flags["json"])
 
-    ret, out = cmd(name + " " + params + args, fail=fail)
+    if ns != "":
+        ns = "ip netns exec %s " % (ns)
+
+    ret, out = cmd(ns + name + " " + params + args, fail=fail)
     if JSON and len(out.strip()) != 0:
         return ret, json.loads(out)
     else:
         return ret, out
 
-def bpftool(args, JSON=True, fail=True):
-    return tool("bpftool", args, {"json":"-p"}, JSON=JSON, fail=fail)
+def bpftool(args, JSON=True, ns="", fail=True):
+    return tool("bpftool", args, {"json":"-p"}, JSON=JSON, ns=ns, fail=fail)
 
-def bpftool_prog_list(expected=None):
-    _, progs = bpftool("prog show", JSON=True, fail=True)
+def bpftool_prog_list(expected=None, ns=""):
+    _, progs = bpftool("prog show", JSON=True, ns=ns, fail=True)
     if expected is not None:
         if len(progs) != expected:
             fail(True, "%d BPF programs loaded, expected %d" %
@@ -158,13 +164,13 @@ def bpftool_prog_list_wait(expected=0, n_retry=20):
         time.sleep(0.05)
     raise Exception("Time out waiting for program counts to stabilize want %d, have %d" % (expected, nprogs))
 
-def ip(args, force=False, JSON=True, fail=True):
+def ip(args, force=False, JSON=True, ns="", fail=True):
     if force:
         args = "-force " + args
-    return tool("ip", args, {"json":"-j"}, JSON=JSON, fail=fail)
+    return tool("ip", args, {"json":"-j"}, JSON=JSON, ns=ns, fail=fail)
 
-def tc(args, JSON=True, fail=True):
-    return tool("tc", args, {"json":"-p"}, JSON=JSON, fail=fail)
+def tc(args, JSON=True, ns="", fail=True):
+    return tool("tc", args, {"json":"-p"}, JSON=JSON, ns=ns, fail=fail)
 
 def ethtool(dev, opt, args, fail=True):
     return cmd("ethtool %s %s %s" % (opt, dev["ifname"], args), fail=fail)
@@ -178,6 +184,15 @@ def bpf_pinned(name):
 def bpf_bytecode(bytecode):
     return "bytecode \"%s\"" % (bytecode)
 
+def mknetns(n_retry=10):
+    for i in range(n_retry):
+        name = ''.join([random.choice(string.ascii_letters) for i in range(8)])
+        ret, _ = ip("netns add %s" % (name), fail=False)
+        if ret == 0:
+            netns.append(name)
+            return name
+    return None
+
 class DebugfsDir:
     """
     Class for accessing DebugFS directories as a dictionary.
@@ -237,6 +252,8 @@ class NetdevSim:
         self.dev = self._netdevsim_create()
         devs.append(self)
 
+        self.ns = ""
+
         self.dfs_dir = '/sys/kernel/debug/netdevsim/%s' % (self.dev['ifname'])
         self.dfs_refresh()
 
@@ -257,7 +274,7 @@ class NetdevSim:
 
     def remove(self):
         devs.remove(self)
-        ip("link del dev %s" % (self.dev["ifname"]))
+        ip("link del dev %s" % (self.dev["ifname"]), ns=self.ns)
 
     def dfs_refresh(self):
         self.dfs = DebugfsDir(self.dfs_dir)
@@ -285,6 +302,11 @@ class NetdevSim:
             time.sleep(0.05)
         raise Exception("Time out waiting for program counts to stabilize want %d/%d, have %d bound, %d loaded" % (bound, total, nbound, nprogs))
 
+    def set_ns(self, ns):
+        name = "1" if ns == "" else ns
+        ip("link set dev %s netns %s" % (self.dev["ifname"], name), ns=self.ns)
+        self.ns = ns
+
     def set_mtu(self, mtu, fail=True):
         return ip("link set dev %s mtu %d" % (self.dev["ifname"], mtu),
                   fail=fail)
@@ -372,6 +394,8 @@ def clean_up():
         dev.remove()
     for f in files:
         cmd("rm -f %s" % (f))
+    for ns in netns:
+        cmd("ip netns delete %s" % (ns))
 
 def pin_prog(file_name, idx=0):
     progs = bpftool_prog_list(expected=(idx + 1))
@@ -381,6 +405,35 @@ def pin_prog(file_name, idx=0):
 
     return file_name, bpf_pinned(file_name)
 
+def check_dev_info(other_ns, ns, pin_file=None, removed=False):
+    if removed:
+        bpftool_prog_list(expected=0)
+        ret, err = bpftool("prog show pin %s" % (pin_file), fail=False)
+        fail(ret == 0, "Showing prog with removed device did not fail")
+        fail(err["error"].find("No such device") == -1,
+             "Showing prog with removed device expected ENODEV, error is %s" %
+             (err["error"]))
+        return
+    progs = bpftool_prog_list(expected=int(not removed), ns=ns)
+    prog = progs[0]
+
+    fail("dev" not in prog.keys(), "Device parameters not reported")
+    dev = prog["dev"]
+    fail("ifindex" not in dev.keys(), "Device parameters not reported")
+    fail("ns_dev" not in dev.keys(), "Device parameters not reported")
+    fail("ns_inode" not in dev.keys(), "Device parameters not reported")
+
+    if not removed and not other_ns:
+        fail("ifname" not in dev.keys(), "Ifname not reported")
+        fail(dev["ifname"] != sim["ifname"],
+             "Ifname incorrect %s vs %s" % (dev["ifname"], sim["ifname"]))
+    else:
+        fail("ifname" in dev.keys(), "Ifname is reported for other ns")
+        if removed:
+            fail(dev["ifindex"] != 0, "Device perameters not zero on removed")
+            fail(dev["ns_dev"] != 0, "Device perameters not zero on removed")
+            fail(dev["ns_inode"] != 0, "Device perameters not zero on removed")
+
 # Parse command line
 parser = argparse.ArgumentParser()
 parser.add_argument("--log", help="output verbose log to given file")
@@ -417,6 +470,12 @@ for s in samples:
     skip(ret != 0, "sample %s/%s not found, please compile it" %
          (bpf_test_dir, s))
 
+# Check if net namespaces seem to work
+ns = mknetns()
+skip(ns is None, "Could not create a net namespace")
+cmd("ip netns delete %s" % (ns))
+netns = []
+
 try:
     obj = bpf_obj("sample_ret0.o")
     bytecode = bpf_bytecode("1,6 0 0 4294967295,")
@@ -549,6 +608,8 @@ try:
     progs = bpftool_prog_list(expected=1)
     fail(ipl["xdp"]["prog"]["id"] != progs[0]["id"],
          "Loaded program has wrong ID")
+    fail("dev" in progs[0].keys(),
+         "Device parameters reported for non-offloaded program")
 
     start_test("Test XDP prog replace with bad flags...")
     ret, _ = sim.set_xdp(obj, "offload", force=True, fail=False)
@@ -673,6 +734,35 @@ try:
     fail(time_diff < delay_sec, "Removal process took %s, expected %s" %
          (time_diff, delay_sec))
 
+    # Remove all pinned files and reinstantiate the netdev
+    clean_up()
+    bpftool_prog_list_wait(expected=0)
+
+    sim = NetdevSim()
+    sim.set_ethtool_tc_offloads(True)
+    sim.set_xdp(obj, "offload")
+
+    start_test("Test bpftool bound info reporting (own ns)...")
+    check_dev_info(False, "")
+
+    start_test("Test bpftool bound info reporting (other ns)...")
+    ns = mknetns()
+    sim.set_ns(ns)
+    check_dev_info(True, "")
+
+    start_test("Test bpftool bound info reporting (remote ns)...")
+    check_dev_info(False, ns)
+
+    start_test("Test bpftool bound info reporting (back to own ns)...")
+    sim.set_ns("")
+    check_dev_info(False, "")
+
+    pin_file, _ = pin_prog("/sys/fs/bpf/tmp")
+    sim.remove()
+
+    start_test("Test bpftool bound info reporting (removed dev)...")
+    check_dev_info(True, "", pin_file=pin_file, removed=True)
+
     print("%s: OK" % (os.path.basename(__file__)))
 
 finally: