diff mbox series

[RFC,bpf-next,6/8] bpf: Add cookie in sk_reuseport_md.

Message ID 20201117094023.3685-7-kuniyu@amazon.co.jp (mailing list archive)
State RFC
Delegated to: BPF
Headers show
Series Socket migration for SO_REUSEPORT. | expand

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netdev/tree_selection success Clearly marked for bpf-next
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netdev/build_32bit success Errors and warnings before: 15752 this patch: 15752
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netdev/build_allmodconfig_warn success Errors and warnings before: 15664 this patch: 15664
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netdev/stable success Stable not CCed

Commit Message

Iwashima, Kuniyuki Nov. 17, 2020, 9:40 a.m. UTC 
We will call sock_reuseport.prog for socket migration in the next commit,
so the eBPF program has to know which listener is closing in order to
select the new listener.

Currently, we can get a unique ID for each listener in the userspace by
calling bpf_map_lookup_elem() for BPF_MAP_TYPE_REUSEPORT_SOCKARRAY map.
This patch exposes the ID to the eBPF program.

Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
---
 include/linux/bpf.h            | 1 +
 include/uapi/linux/bpf.h       | 1 +
 net/core/filter.c              | 8 ++++++++
 tools/include/uapi/linux/bpf.h | 1 +
 4 files changed, 11 insertions(+)

Comments

Martin KaFai Lau Nov. 19, 2020, 12:11 a.m. UTC | #1 
On Tue, Nov 17, 2020 at 06:40:21PM +0900, Kuniyuki Iwashima wrote:
> We will call sock_reuseport.prog for socket migration in the next commit,
> so the eBPF program has to know which listener is closing in order to
> select the new listener.
> 
> Currently, we can get a unique ID for each listener in the userspace by
> calling bpf_map_lookup_elem() for BPF_MAP_TYPE_REUSEPORT_SOCKARRAY map.
> This patch exposes the ID to the eBPF program.
> 
> Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
> ---
>  include/linux/bpf.h            | 1 +
>  include/uapi/linux/bpf.h       | 1 +
>  net/core/filter.c              | 8 ++++++++
>  tools/include/uapi/linux/bpf.h | 1 +
>  4 files changed, 11 insertions(+)
> 
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index 581b2a2e78eb..c0646eceffa2 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -1897,6 +1897,7 @@ struct sk_reuseport_kern {
>  	u32 hash;
>  	u32 reuseport_id;
>  	bool bind_inany;
> +	u64 cookie;
>  };
>  bool bpf_tcp_sock_is_valid_access(int off, int size, enum bpf_access_type type,
>  				  struct bpf_insn_access_aux *info);
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 162999b12790..3fcddb032838 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -4403,6 +4403,7 @@ struct sk_reuseport_md {
>  	__u32 ip_protocol;	/* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */
>  	__u32 bind_inany;	/* Is sock bound to an INANY address? */
>  	__u32 hash;		/* A hash of the packet 4 tuples */
> +	__u64 cookie;		/* ID of the listener in map */
Instead of only adding the cookie of a sk, lets make the sk pointer available:

	__bpf_md_ptr(struct bpf_sock *, sk);

and then use the BPF_FUNC_get_socket_cookie to get the cookie.

Other fields of the sk can also be directly accessed too once
the sk pointer is available.
Iwashima, Kuniyuki Nov. 19, 2020, 10:10 p.m. UTC | #2 
From:   Martin KaFai Lau <kafai@fb.com>
Date:   Wed, 18 Nov 2020 16:11:54 -0800
> On Tue, Nov 17, 2020 at 06:40:21PM +0900, Kuniyuki Iwashima wrote:
> > We will call sock_reuseport.prog for socket migration in the next commit,
> > so the eBPF program has to know which listener is closing in order to
> > select the new listener.
> > 
> > Currently, we can get a unique ID for each listener in the userspace by
> > calling bpf_map_lookup_elem() for BPF_MAP_TYPE_REUSEPORT_SOCKARRAY map.
> > This patch exposes the ID to the eBPF program.
> > 
> > Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
> > Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
> > ---
> >  include/linux/bpf.h            | 1 +
> >  include/uapi/linux/bpf.h       | 1 +
> >  net/core/filter.c              | 8 ++++++++
> >  tools/include/uapi/linux/bpf.h | 1 +
> >  4 files changed, 11 insertions(+)
> > 
> > diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> > index 581b2a2e78eb..c0646eceffa2 100644
> > --- a/include/linux/bpf.h
> > +++ b/include/linux/bpf.h
> > @@ -1897,6 +1897,7 @@ struct sk_reuseport_kern {
> >  	u32 hash;
> >  	u32 reuseport_id;
> >  	bool bind_inany;
> > +	u64 cookie;
> >  };
> >  bool bpf_tcp_sock_is_valid_access(int off, int size, enum bpf_access_type type,
> >  				  struct bpf_insn_access_aux *info);
> > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > index 162999b12790..3fcddb032838 100644
> > --- a/include/uapi/linux/bpf.h
> > +++ b/include/uapi/linux/bpf.h
> > @@ -4403,6 +4403,7 @@ struct sk_reuseport_md {
> >  	__u32 ip_protocol;	/* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */
> >  	__u32 bind_inany;	/* Is sock bound to an INANY address? */
> >  	__u32 hash;		/* A hash of the packet 4 tuples */
> > +	__u64 cookie;		/* ID of the listener in map */
> Instead of only adding the cookie of a sk, lets make the sk pointer available:
> 
> 	__bpf_md_ptr(struct bpf_sock *, sk);
> 
> and then use the BPF_FUNC_get_socket_cookie to get the cookie.
> 
> Other fields of the sk can also be directly accessed too once
> the sk pointer is available.

Oh, I did not know BPF_FUNC_get_socket_cookie.
I will add the sk pointer and use the helper function in the next spin!
Thank you.
diff mbox series

Patch

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 581b2a2e78eb..c0646eceffa2 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1897,6 +1897,7 @@  struct sk_reuseport_kern {
 	u32 hash;
 	u32 reuseport_id;
 	bool bind_inany;
+	u64 cookie;
 };
 bool bpf_tcp_sock_is_valid_access(int off, int size, enum bpf_access_type type,
 				  struct bpf_insn_access_aux *info);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 162999b12790..3fcddb032838 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -4403,6 +4403,7 @@  struct sk_reuseport_md {
 	__u32 ip_protocol;	/* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */
 	__u32 bind_inany;	/* Is sock bound to an INANY address? */
 	__u32 hash;		/* A hash of the packet 4 tuples */
+	__u64 cookie;		/* ID of the listener in map */
 };
 
 #define BPF_TAG_SIZE	8
diff --git a/net/core/filter.c b/net/core/filter.c
index 2ca5eecebacf..01e28f283962 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -9862,6 +9862,7 @@  static void bpf_init_reuseport_kern(struct sk_reuseport_kern *reuse_kern,
 	reuse_kern->hash = hash;
 	reuse_kern->reuseport_id = reuse->reuseport_id;
 	reuse_kern->bind_inany = reuse->bind_inany;
+	reuse_kern->cookie = sock_gen_cookie(sk);
 }
 
 struct sock *bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk,
@@ -10010,6 +10011,9 @@  sk_reuseport_is_valid_access(int off, int size,
 	case offsetof(struct sk_reuseport_md, hash):
 		return size == size_default;
 
+	case bpf_ctx_range(struct sk_reuseport_md, cookie):
+		return size == sizeof(__u64);
+
 	/* Fields that allow narrowing */
 	case bpf_ctx_range(struct sk_reuseport_md, eth_protocol):
 		if (size < sizeof_field(struct sk_buff, protocol))
@@ -10082,6 +10086,10 @@  static u32 sk_reuseport_convert_ctx_access(enum bpf_access_type type,
 	case offsetof(struct sk_reuseport_md, bind_inany):
 		SK_REUSEPORT_LOAD_FIELD(bind_inany);
 		break;
+
+	case offsetof(struct sk_reuseport_md, cookie):
+		SK_REUSEPORT_LOAD_FIELD(cookie);
+		break;
 	}
 
 	return insn - insn_buf;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 162999b12790..3fcddb032838 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -4403,6 +4403,7 @@  struct sk_reuseport_md {
 	__u32 ip_protocol;	/* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */
 	__u32 bind_inany;	/* Is sock bound to an INANY address? */
 	__u32 hash;		/* A hash of the packet 4 tuples */
+	__u64 cookie;		/* ID of the listener in map */
 };
 
 #define BPF_TAG_SIZE	8