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 <ka...@fb.com> Signed-off-by: Kuniyuki Iwashima <kun...@amazon.co.jp> --- include/uapi/linux/bpf.h | 8 ++++++++ net/core/filter.c | 22 ++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 8 ++++++++ 3 files changed, 38 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index cf518e83df5c..a688a7a4fe85 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1655,6 +1655,13 @@ 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 @@ -4463,6 +4470,7 @@ 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 7bdf62f24044..9f7018e3f545 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4631,6 +4631,18 @@ static const struct bpf_func_proto bpf_get_socket_cookie_sock_proto = { .arg1_type = ARG_PTR_TO_CTX, }; +BPF_CALL_1(bpf_get_socket_pointer_cookie, struct sock *, sk) +{ + return __sock_gen_cookie(sk); +} + +static const struct bpf_func_proto bpf_get_socket_pointer_cookie_proto = { + .func = bpf_get_socket_pointer_cookie, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_SOCKET, +}; + BPF_CALL_1(bpf_get_socket_cookie_sock_ops, struct bpf_sock_ops_kern *, ctx) { return __sock_gen_cookie(ctx->sk); @@ -9989,6 +10001,8 @@ sk_reuseport_func_proto(enum bpf_func_id func_id, return &sk_reuseport_load_bytes_proto; case BPF_FUNC_skb_load_bytes_relative: return &sk_reuseport_load_bytes_relative_proto; + case BPF_FUNC_get_socket_cookie: + return &bpf_get_socket_pointer_cookie_proto; default: return bpf_base_func_proto(func_id); } @@ -10022,6 +10036,10 @@ 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)) @@ -10098,6 +10116,10 @@ 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 cf518e83df5c..a688a7a4fe85 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1655,6 +1655,13 @@ 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 @@ -4463,6 +4470,7 @@ 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 Git-113)
