All of lore.kernel.org
 help / color / mirror / Atom feed
From: Daniel Borkmann <daniel@iogearbox.net>
To: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org, martin.lau@kernel.org,
	razor@blackwall.org, ast@kernel.org, andrii@kernel.org,
	john.fastabend@gmail.com, Daniel Borkmann <daniel@iogearbox.net>
Subject: [PATCH bpf-next 2/8] meta, bpf: Add bpf link support for meta device
Date: Tue, 26 Sep 2023 07:59:07 +0200	[thread overview]
Message-ID: <20230926055913.9859-3-daniel@iogearbox.net> (raw)
In-Reply-To: <20230926055913.9859-1-daniel@iogearbox.net>

This adds BPF link support for meta device (BPF_LINK_TYPE_META). Similar
as with tcx or XDP, the BPF link for meta contains the device.

The bpf_mprog API has been reused for its implementation. For details, see
also commit e420bed0250 ("bpf: Add fd-based tcx multi-prog infra with link
support").

This is now the second user of bpf_mprog after tcx, and in meta case the
implementation is also a bit more straight forward since it does not need
to deal with miniq.

The UAPI extensions for the BPF_LINK_CREATE command are similar as for tcx,
that is, relative_{fd,id} and expected_revision.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 drivers/net/meta.c             | 211 ++++++++++++++++++++++++++++++++-
 include/net/meta.h             |   7 ++
 include/uapi/linux/bpf.h       |  11 ++
 kernel/bpf/syscall.c           |   2 +-
 tools/include/uapi/linux/bpf.h |  11 ++
 5 files changed, 240 insertions(+), 2 deletions(-)

diff --git a/drivers/net/meta.c b/drivers/net/meta.c
index e464f547b0a6..8cb39281c455 100644
--- a/drivers/net/meta.c
+++ b/drivers/net/meta.c
@@ -27,6 +27,11 @@ struct meta {
 	u32 headroom;
 };
 
+struct meta_link {
+	struct bpf_link link;
+	struct net_device *dev;
+};
+
 static void meta_scrub_minimum(struct sk_buff *skb)
 {
 	skb->skb_iif = 0;
@@ -576,6 +581,207 @@ int meta_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr)
 	return ret;
 }
 
+static struct meta_link *meta_link(struct bpf_link *link)
+{
+	return container_of(link, struct meta_link, link);
+}
+
+static const struct meta_link *meta_link_const(const struct bpf_link *link)
+{
+	return meta_link((struct bpf_link *)link);
+}
+
+static int meta_link_prog_attach(struct bpf_link *link, u32 flags,
+				 u32 id_or_fd, u64 revision)
+{
+	struct meta_link *meta = meta_link(link);
+	struct bpf_mprog_entry *entry, *entry_new;
+	struct net_device *dev = meta->dev;
+	int ret;
+
+	ASSERT_RTNL();
+	entry = meta_entry_fetch(dev, true);
+	ret = bpf_mprog_attach(entry, &entry_new, link->prog, link, NULL, flags,
+			       id_or_fd, revision);
+	if (!ret) {
+		if (entry != entry_new) {
+			meta_entry_update(dev, entry_new);
+			meta_entry_sync();
+		}
+		bpf_mprog_commit(entry);
+	}
+	return ret;
+}
+
+static void meta_link_release(struct bpf_link *link)
+{
+	struct meta_link *meta = meta_link(link);
+	struct bpf_mprog_entry *entry, *entry_new;
+	struct net_device *dev;
+	int ret = 0;
+
+	rtnl_lock();
+	dev = meta->dev;
+	if (!dev)
+		goto out;
+	entry = meta_entry_fetch(dev, false);
+	if (!entry) {
+		ret = -ENOENT;
+		goto out;
+	}
+	ret = bpf_mprog_detach(entry, &entry_new, link->prog, link, 0, 0, 0);
+	if (!ret) {
+		if (!bpf_mprog_total(entry_new))
+			entry_new = NULL;
+		meta_entry_update(dev, entry_new);
+		meta_entry_sync();
+		bpf_mprog_commit(entry);
+		meta->dev = NULL;
+	}
+out:
+	WARN_ON_ONCE(ret);
+	rtnl_unlock();
+}
+
+static int meta_link_update(struct bpf_link *link, struct bpf_prog *nprog,
+			    struct bpf_prog *oprog)
+{
+	struct meta_link *meta = meta_link(link);
+	struct bpf_mprog_entry *entry, *entry_new;
+	struct net_device *dev;
+	int ret = 0;
+
+	rtnl_lock();
+	dev = meta->dev;
+	if (!dev) {
+		ret = -ENOLINK;
+		goto out;
+	}
+	if (oprog && link->prog != oprog) {
+		ret = -EPERM;
+		goto out;
+	}
+	oprog = link->prog;
+	if (oprog == nprog) {
+		bpf_prog_put(nprog);
+		goto out;
+	}
+	entry = meta_entry_fetch(dev, false);
+	if (!entry) {
+		ret = -ENOENT;
+		goto out;
+	}
+	ret = bpf_mprog_attach(entry, &entry_new, nprog, link, oprog,
+			       BPF_F_REPLACE | BPF_F_ID,
+			       link->prog->aux->id, 0);
+	if (!ret) {
+		WARN_ON_ONCE(entry != entry_new);
+		oprog = xchg(&link->prog, nprog);
+		bpf_prog_put(oprog);
+		bpf_mprog_commit(entry);
+	}
+out:
+	rtnl_unlock();
+	return ret;
+}
+
+static void meta_link_dealloc(struct bpf_link *link)
+{
+	kfree(meta_link(link));
+}
+
+static void meta_link_fdinfo(const struct bpf_link *link, struct seq_file *seq)
+{
+	const struct meta_link *meta = meta_link_const(link);
+	u32 ifindex = 0;
+
+	rtnl_lock();
+	if (meta->dev)
+		ifindex = meta->dev->ifindex;
+	rtnl_unlock();
+
+	seq_printf(seq, "ifindex:\t%u\n", ifindex);
+}
+
+static int meta_link_fill_info(const struct bpf_link *link,
+			       struct bpf_link_info *info)
+{
+	const struct meta_link *meta = meta_link_const(link);
+	u32 ifindex = 0;
+
+	rtnl_lock();
+	if (meta->dev)
+		ifindex = meta->dev->ifindex;
+	rtnl_unlock();
+
+	info->meta.ifindex = ifindex;
+	return 0;
+}
+
+static int meta_link_detach(struct bpf_link *link)
+{
+	meta_link_release(link);
+	return 0;
+}
+
+static const struct bpf_link_ops meta_link_lops = {
+	.release	= meta_link_release,
+	.detach		= meta_link_detach,
+	.dealloc	= meta_link_dealloc,
+	.update_prog	= meta_link_update,
+	.show_fdinfo	= meta_link_fdinfo,
+	.fill_link_info	= meta_link_fill_info,
+};
+
+static int meta_link_init(struct meta_link *meta,
+			  struct bpf_link_primer *link_primer,
+			  struct net_device *dev, struct bpf_prog *prog)
+{
+	bpf_link_init(&meta->link, BPF_LINK_TYPE_META, &meta_link_lops, prog);
+	meta->dev = dev;
+	return bpf_link_prime(&meta->link, link_primer);
+}
+
+int meta_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	struct bpf_link_primer link_primer;
+	struct net_device *dev;
+	struct meta_link *meta;
+	int ret;
+
+	rtnl_lock();
+	dev = meta_dev_fetch(current->nsproxy->net_ns,
+			     attr->link_create.target_ifindex,
+			     attr->link_create.attach_type);
+	if (IS_ERR(dev)) {
+		ret = PTR_ERR(dev);
+		goto out;
+	}
+	meta = kzalloc(sizeof(*meta), GFP_USER);
+	if (!meta) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	ret = meta_link_init(meta, &link_primer, dev, prog);
+	if (ret) {
+		kfree(meta);
+		goto out;
+	}
+	ret = meta_link_prog_attach(&meta->link,
+				    attr->link_create.flags,
+				    attr->link_create.meta.relative_fd,
+				    attr->link_create.meta.expected_revision);
+	if (ret) {
+		meta->dev = NULL;
+		bpf_link_cleanup(&link_primer);
+		goto out;
+	}
+	ret = bpf_link_settle(&link_primer);
+out:
+	rtnl_unlock();
+	return ret;
+}
+
 static void meta_release_all(struct net_device *dev)
 {
 	struct bpf_mprog_entry *entry;
@@ -589,7 +795,10 @@ static void meta_release_all(struct net_device *dev)
 	meta_entry_update(dev, NULL);
 	meta_entry_sync();
 	bpf_mprog_foreach_tuple(entry, fp, cp, tuple) {
-		bpf_prog_put(tuple.prog);
+		if (tuple.link)
+			meta_link(tuple.link)->dev = NULL;
+		else
+			bpf_prog_put(tuple.prog);
 	}
 }
 
diff --git a/include/net/meta.h b/include/net/meta.h
index 20fc61d05970..f1abe1d6d02d 100644
--- a/include/net/meta.h
+++ b/include/net/meta.h
@@ -7,6 +7,7 @@
 
 #ifdef CONFIG_META
 int meta_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog);
+int meta_link_attach(const union bpf_attr *attr, struct bpf_prog *prog);
 int meta_prog_detach(const union bpf_attr *attr, struct bpf_prog *prog);
 int meta_prog_query(const union bpf_attr *attr, union bpf_attr __user *uattr);
 #else
@@ -16,6 +17,12 @@ static inline int meta_prog_attach(const union bpf_attr *attr,
 	return -EINVAL;
 }
 
+static inline int meta_link_attach(const union bpf_attr *attr,
+				   struct bpf_prog *prog)
+{
+	return -EINVAL;
+}
+
 static inline int meta_prog_detach(const union bpf_attr *attr,
 				   struct bpf_prog *prog)
 {
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 00a875720e84..fd069f285fbc 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1068,6 +1068,7 @@ enum bpf_link_type {
 	BPF_LINK_TYPE_NETFILTER = 10,
 	BPF_LINK_TYPE_TCX = 11,
 	BPF_LINK_TYPE_UPROBE_MULTI = 12,
+	BPF_LINK_TYPE_META = 12,
 	MAX_BPF_LINK_TYPE,
 };
 
@@ -1653,6 +1654,13 @@ union bpf_attr {
 				__u32		flags;
 				__u32		pid;
 			} uprobe_multi;
+			struct {
+				union {
+					__u32	relative_fd;
+					__u32	relative_id;
+				};
+				__u64		expected_revision;
+			} meta;
 		};
 	} link_create;
 
@@ -6564,6 +6572,9 @@ struct bpf_link_info {
 			__u32 ifindex;
 			__u32 attach_type;
 		} tcx;
+		struct {
+			__u32 ifindex;
+		} meta;
 	};
 } __attribute__((aligned(8)));
 
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 51baf4355c39..b689da4de280 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -4969,7 +4969,7 @@ static int link_create(union bpf_attr *attr, bpfptr_t uattr)
 		    attr->link_create.attach_type == BPF_TCX_EGRESS)
 			ret = tcx_link_attach(attr, prog);
 		else
-			ret = -EINVAL;
+			ret = meta_link_attach(attr, prog);
 		break;
 	case BPF_PROG_TYPE_NETFILTER:
 		ret = bpf_nf_link_attach(attr, prog);
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 00a875720e84..fd069f285fbc 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1068,6 +1068,7 @@ enum bpf_link_type {
 	BPF_LINK_TYPE_NETFILTER = 10,
 	BPF_LINK_TYPE_TCX = 11,
 	BPF_LINK_TYPE_UPROBE_MULTI = 12,
+	BPF_LINK_TYPE_META = 12,
 	MAX_BPF_LINK_TYPE,
 };
 
@@ -1653,6 +1654,13 @@ union bpf_attr {
 				__u32		flags;
 				__u32		pid;
 			} uprobe_multi;
+			struct {
+				union {
+					__u32	relative_fd;
+					__u32	relative_id;
+				};
+				__u64		expected_revision;
+			} meta;
 		};
 	} link_create;
 
@@ -6564,6 +6572,9 @@ struct bpf_link_info {
 			__u32 ifindex;
 			__u32 attach_type;
 		} tcx;
+		struct {
+			__u32 ifindex;
+		} meta;
 	};
 } __attribute__((aligned(8)));
 
-- 
2.34.1


  parent reply	other threads:[~2023-09-26  5:59 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-26  5:59 [PATCH bpf-next 0/8] Add bpf programmable device Daniel Borkmann
2023-09-26  5:59 ` [PATCH bpf-next 1/8] meta, bpf: Add bpf programmable meta device Daniel Borkmann
2023-09-26 21:26   ` Stanislav Fomichev
2023-09-28  9:16   ` Toke Høiland-Jørgensen
2023-09-28 12:01     ` Willem de Bruijn
2023-09-28 21:14     ` Daniel Borkmann
2023-09-29 19:25       ` Alexei Starovoitov
2023-10-13 11:26   ` Florian Kauer
2023-09-26  5:59 ` Daniel Borkmann [this message]
2023-09-28  0:12   ` [PATCH bpf-next 2/8] meta, bpf: Add bpf link support for " Andrii Nakryiko
2023-09-26  5:59 ` [PATCH bpf-next 3/8] tools: Sync if_link uapi header Daniel Borkmann
2023-09-26  5:59 ` [PATCH bpf-next 4/8] libbpf: Add link-based API for meta Daniel Borkmann
2023-09-26 11:19   ` Quentin Monnet
2023-09-28  0:12   ` Andrii Nakryiko
2023-09-28 21:30     ` Daniel Borkmann
2023-09-26  5:59 ` [PATCH bpf-next 5/8] bpftool: Implement link show support " Daniel Borkmann
2023-09-26 11:19   ` Quentin Monnet
2023-09-26  5:59 ` [PATCH bpf-next 6/8] bpftool: Extend net dump with meta progs Daniel Borkmann
2023-09-26 11:19   ` Quentin Monnet
2023-09-26  5:59 ` [PATCH bpf-next 7/8] selftests/bpf: Add netlink helper library Daniel Borkmann
2023-09-26 21:35   ` Stanislav Fomichev
2023-09-26  5:59 ` [PATCH bpf-next 8/8] selftests/bpf: Add selftests for meta Daniel Borkmann

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20230926055913.9859-3-daniel@iogearbox.net \
    --to=daniel@iogearbox.net \
    --cc=andrii@kernel.org \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=john.fastabend@gmail.com \
    --cc=martin.lau@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=razor@blackwall.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.