Re: [PATCH v1 bpf-next 09/11] bpf: Support bpf_get_socket_cookie_sock() for BPF_PROG_TYPE_SK_REUSEPORT.
I'm sending this mail just for logging because I failed to send mails only
to LKML, netdev, and bpf yesterday.
From: Martin KaFai Lau
Date: Fri, 4 Dec 2020 11:58:07 -0800
> On Tue, Dec 01, 2020 at 11:44:16PM +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 makes the sk pointer available in sk_reuseport_md so that we can
> > get the ID by BPF_FUNC_get_socket_cookie() in the eBPF program.
> >
> > Link:
> > https://lore.kernel.org/netdev/20201119001154.kapwihc2plp4f...@kafai-mbp.dhcp.thefacebook.com/
> > Suggested-by: Martin KaFai Lau
> > Signed-off-by: Kuniyuki Iwashima
> > ---
> > include/uapi/linux/bpf.h | 8
> > net/core/filter.c | 12 +++-
> > tools/include/uapi/linux/bpf.h | 8
> > 3 files changed, 27 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > index efe342bf3dbc..3e9b8bd42b4e 100644
> > --- a/include/uapi/linux/bpf.h
> > +++ b/include/uapi/linux/bpf.h
> > @@ -1650,6 +1650,13 @@ union bpf_attr {
> > * A 8-byte long non-decreasing number on success, or 0 if
> > the
> > * socket field is missing inside *skb*.
> > *
> > + * u64 bpf_get_socket_cookie(struct bpf_sock *sk)
> > + * Description
> > + * Equivalent to bpf_get_socket_cookie() helper that
> > accepts
> > + * *skb*, but gets socket from **struct bpf_sock** context.
> > + * Return
> > + * A 8-byte long non-decreasing number.
> > + *
> > * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
> > * Description
> > * Equivalent to bpf_get_socket_cookie() helper that
> > accepts
> > @@ -4420,6 +4427,7 @@ struct sk_reuseport_md {
> > __u32 bind_inany; /* Is sock bound to an INANY address? */
> > __u32 hash; /* A hash of the packet 4 tuples */
> > __u8 migration; /* Migration type */
> > + __bpf_md_ptr(struct bpf_sock *, sk); /* current listening socket */
> > };
> >
> > #define BPF_TAG_SIZE 8
> > diff --git a/net/core/filter.c b/net/core/filter.c
> > index 0a0634787bb4..1059d31847ef 100644
> > --- a/net/core/filter.c
> > +++ b/net/core/filter.c
> > @@ -4628,7 +4628,7 @@ static const struct bpf_func_proto
> > bpf_get_socket_cookie_sock_proto = {
> > .func = bpf_get_socket_cookie_sock,
> > .gpl_only = false,
> > .ret_type = RET_INTEGER,
> > - .arg1_type = ARG_PTR_TO_CTX,
> > + .arg1_type = ARG_PTR_TO_SOCKET,
> This will break existing bpf prog (BPF_PROG_TYPE_CGROUP_SOCK)
> using this proto. A new proto is needed and there is
> an on-going patch doing this [0].
>
> [0]: https://lore.kernel.org/bpf/20201203213330.1657666-1-rev...@google.com/
Thank you for notifying me of this patch!
I will define another proto, but may drop the part if the above patch is
already merged then.
Re: [PATCH v1 bpf-next 09/11] bpf: Support bpf_get_socket_cookie_sock() for BPF_PROG_TYPE_SK_REUSEPORT.
On Tue, Dec 01, 2020 at 11:44:16PM +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 makes the sk pointer available in sk_reuseport_md so that we can
> get the ID by BPF_FUNC_get_socket_cookie() in the eBPF program.
>
> Link:
> https://lore.kernel.org/netdev/20201119001154.kapwihc2plp4f...@kafai-mbp.dhcp.thefacebook.com/
> Suggested-by: Martin KaFai Lau
> Signed-off-by: Kuniyuki Iwashima
> ---
> include/uapi/linux/bpf.h | 8
> net/core/filter.c | 12 +++-
> tools/include/uapi/linux/bpf.h | 8
> 3 files changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index efe342bf3dbc..3e9b8bd42b4e 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -1650,6 +1650,13 @@ union bpf_attr {
> * A 8-byte long non-decreasing number on success, or 0 if the
> * socket field is missing inside *skb*.
> *
> + * u64 bpf_get_socket_cookie(struct bpf_sock *sk)
> + * Description
> + * Equivalent to bpf_get_socket_cookie() helper that accepts
> + * *skb*, but gets socket from **struct bpf_sock** context.
> + * Return
> + * A 8-byte long non-decreasing number.
> + *
> * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
> * Description
> * Equivalent to bpf_get_socket_cookie() helper that accepts
> @@ -4420,6 +4427,7 @@ struct sk_reuseport_md {
> __u32 bind_inany; /* Is sock bound to an INANY address? */
> __u32 hash; /* A hash of the packet 4 tuples */
> __u8 migration; /* Migration type */
> + __bpf_md_ptr(struct bpf_sock *, sk); /* current listening socket */
> };
>
> #define BPF_TAG_SIZE 8
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 0a0634787bb4..1059d31847ef 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -4628,7 +4628,7 @@ static const struct bpf_func_proto
> bpf_get_socket_cookie_sock_proto = {
> .func = bpf_get_socket_cookie_sock,
> .gpl_only = false,
> .ret_type = RET_INTEGER,
> - .arg1_type = ARG_PTR_TO_CTX,
> + .arg1_type = ARG_PTR_TO_SOCKET,
This will break existing bpf prog (BPF_PROG_TYPE_CGROUP_SOCK)
using this proto. A new proto is needed and there is
an on-going patch doing this [0].
[0]: https://lore.kernel.org/bpf/20201203213330.1657666-1-rev...@google.com/
[PATCH v1 bpf-next 09/11] bpf: Support bpf_get_socket_cookie_sock() for BPF_PROG_TYPE_SK_REUSEPORT.
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 makes the sk pointer available in sk_reuseport_md so that we can
get the ID by BPF_FUNC_get_socket_cookie() in the eBPF program.
Link:
https://lore.kernel.org/netdev/20201119001154.kapwihc2plp4f...@kafai-mbp.dhcp.thefacebook.com/
Suggested-by: Martin KaFai Lau
Signed-off-by: Kuniyuki Iwashima
---
include/uapi/linux/bpf.h | 8
net/core/filter.c | 12 +++-
tools/include/uapi/linux/bpf.h | 8
3 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index efe342bf3dbc..3e9b8bd42b4e 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1650,6 +1650,13 @@ union bpf_attr {
* A 8-byte long non-decreasing number on success, or 0 if the
* socket field is missing inside *skb*.
*
+ * u64 bpf_get_socket_cookie(struct bpf_sock *sk)
+ * Description
+ * Equivalent to bpf_get_socket_cookie() helper that accepts
+ * *skb*, but gets socket from **struct bpf_sock** context.
+ * Return
+ * A 8-byte long non-decreasing number.
+ *
* u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
* Description
* Equivalent to bpf_get_socket_cookie() helper that accepts
@@ -4420,6 +4427,7 @@ struct sk_reuseport_md {
__u32 bind_inany; /* Is sock bound to an INANY address? */
__u32 hash; /* A hash of the packet 4 tuples */
__u8 migration; /* Migration type */
+ __bpf_md_ptr(struct bpf_sock *, sk); /* current listening socket */
};
#define BPF_TAG_SIZE 8
diff --git a/net/core/filter.c b/net/core/filter.c
index 0a0634787bb4..1059d31847ef 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4628,7 +4628,7 @@ static const struct bpf_func_proto
bpf_get_socket_cookie_sock_proto = {
.func = bpf_get_socket_cookie_sock,
.gpl_only = false,
.ret_type = RET_INTEGER,
- .arg1_type = ARG_PTR_TO_CTX,
+ .arg1_type = ARG_PTR_TO_SOCKET,
};
BPF_CALL_1(bpf_get_socket_cookie_sock_ops, struct bpf_sock_ops_kern *, ctx)
@@ -9982,6 +9982,8 @@ sk_reuseport_func_proto(enum bpf_func_id func_id,
return _reuseport_load_bytes_proto;
case BPF_FUNC_skb_load_bytes_relative:
return _reuseport_load_bytes_relative_proto;
+ case BPF_FUNC_get_socket_cookie:
+ return _get_socket_cookie_sock_proto;
default:
return bpf_base_func_proto(func_id);
}
@@ -10015,6 +10017,10 @@ sk_reuseport_is_valid_access(int off, int size,
return prog->expected_attach_type ==
BPF_SK_REUSEPORT_SELECT_OR_MIGRATE &&
size == sizeof(__u8);
+ case offsetof(struct sk_reuseport_md, sk):
+ info->reg_type = PTR_TO_SOCKET;
+ 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))
@@ -10091,6 +10097,10 @@ static u32 sk_reuseport_convert_ctx_access(enum
bpf_access_type type,
case offsetof(struct sk_reuseport_md, migration):
SK_REUSEPORT_LOAD_FIELD(migration);
break;
+
+ case offsetof(struct sk_reuseport_md, sk):
+ SK_REUSEPORT_LOAD_FIELD(sk);
+ break;
}
return insn - insn_buf;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index efe342bf3dbc..3e9b8bd42b4e 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1650,6 +1650,13 @@ union bpf_attr {
* A 8-byte long non-decreasing number on success, or 0 if the
* socket field is missing inside *skb*.
*
+ * u64 bpf_get_socket_cookie(struct bpf_sock *sk)
+ * Description
+ * Equivalent to bpf_get_socket_cookie() helper that accepts
+ * *skb*, but gets socket from **struct bpf_sock** context.
+ * Return
+ * A 8-byte long non-decreasing number.
+ *
* u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
* Description
* Equivalent to bpf_get_socket_cookie() helper that accepts
@@ -4420,6 +4427,7 @@ struct sk_reuseport_md {
__u32 bind_inany; /* Is sock bound to an INANY address? */
__u32 hash; /* A hash of the packet 4 tuples */
__u8 migration; /* Migration type */
+ __bpf_md_ptr(struct bpf_sock *, sk); /* current listening socket */
};
#define BPF_TAG_SIZE 8
--
2.17.2 (Apple
