From 3bc253c2e652cf5f12cd8c00d80d8ec55d67d1a7 Mon Sep 17 00:00:00 2001 From: Geliang Tang Date: Thu, 19 May 2022 16:30:10 -0700 Subject: bpf: Add bpf_skc_to_mptcp_sock_proto This patch implements a new struct bpf_func_proto, named bpf_skc_to_mptcp_sock_proto. Define a new bpf_id BTF_SOCK_TYPE_MPTCP, and a new helper bpf_skc_to_mptcp_sock(), which invokes another new helper bpf_mptcp_sock_from_subflow() in net/mptcp/bpf.c to get struct mptcp_sock from a given subflow socket. v2: Emit BTF type, add func_id checks in verifier.c and bpf_trace.c, remove build check for CONFIG_BPF_JIT v5: Drop EXPORT_SYMBOL (Martin) Co-developed-by: Nicolas Rybowski Co-developed-by: Matthieu Baerts Signed-off-by: Nicolas Rybowski Signed-off-by: Matthieu Baerts Signed-off-by: Geliang Tang Signed-off-by: Mat Martineau Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220519233016.105670-2-mathew.j.martineau@linux.intel.com --- include/linux/bpf.h | 1 + include/linux/btf_ids.h | 3 ++- include/net/mptcp.h | 6 ++++++ include/uapi/linux/bpf.h | 7 +++++++ kernel/bpf/verifier.c | 1 + kernel/trace/bpf_trace.c | 2 ++ net/core/filter.c | 18 ++++++++++++++++++ net/mptcp/Makefile | 2 ++ net/mptcp/bpf.c | 21 +++++++++++++++++++++ scripts/bpf_doc.py | 2 ++ tools/include/uapi/linux/bpf.h | 7 +++++++ 11 files changed, 69 insertions(+), 1 deletion(-) create mode 100644 net/mptcp/bpf.c diff --git a/include/linux/bpf.h b/include/linux/bpf.h index c107392b0ba7..a3ef078401cf 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2231,6 +2231,7 @@ extern const struct bpf_func_proto bpf_skc_to_tcp_timewait_sock_proto; extern const struct bpf_func_proto bpf_skc_to_tcp_request_sock_proto; extern const struct bpf_func_proto bpf_skc_to_udp6_sock_proto; extern const struct bpf_func_proto bpf_skc_to_unix_sock_proto; +extern const struct bpf_func_proto bpf_skc_to_mptcp_sock_proto; extern const struct bpf_func_proto bpf_copy_from_user_proto; extern const struct bpf_func_proto bpf_snprintf_btf_proto; extern const struct bpf_func_proto bpf_snprintf_proto; diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h index bc5d9cc34e4c..335a19092368 100644 --- a/include/linux/btf_ids.h +++ b/include/linux/btf_ids.h @@ -178,7 +178,8 @@ extern struct btf_id_set name; BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP6, tcp6_sock) \ BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP, udp_sock) \ BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock) \ - BTF_SOCK_TYPE(BTF_SOCK_TYPE_UNIX, unix_sock) + BTF_SOCK_TYPE(BTF_SOCK_TYPE_UNIX, unix_sock) \ + BTF_SOCK_TYPE(BTF_SOCK_TYPE_MPTCP, mptcp_sock) enum { #define BTF_SOCK_TYPE(name, str) name, diff --git a/include/net/mptcp.h b/include/net/mptcp.h index 8b1afd6f5cc4..2ba09de955c7 100644 --- a/include/net/mptcp.h +++ b/include/net/mptcp.h @@ -284,4 +284,10 @@ static inline int mptcpv6_init(void) { return 0; } static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { } #endif +#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL) +struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk); +#else +static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; } +#endif + #endif /* __NET_MPTCP_H */ diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 0210f85131b3..56688bee20d9 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5172,6 +5172,12 @@ union bpf_attr { * Return * Map value associated to *key* on *cpu*, or **NULL** if no entry * was found or *cpu* is invalid. + * + * struct mptcp_sock *bpf_skc_to_mptcp_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *mptcp_sock* pointer. + * Return + * *sk* if casting is valid, or **NULL** otherwise. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5370,6 +5376,7 @@ union bpf_attr { FN(ima_file_hash), \ FN(kptr_xchg), \ FN(map_lookup_percpu_elem), \ + FN(skc_to_mptcp_sock), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 9b59581026f8..14e8c17d3d8d 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -509,6 +509,7 @@ static bool is_ptr_cast_function(enum bpf_func_id func_id) func_id == BPF_FUNC_skc_to_tcp_sock || func_id == BPF_FUNC_skc_to_tcp6_sock || func_id == BPF_FUNC_skc_to_udp6_sock || + func_id == BPF_FUNC_skc_to_mptcp_sock || func_id == BPF_FUNC_skc_to_tcp_timewait_sock || func_id == BPF_FUNC_skc_to_tcp_request_sock; } diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 7141ca8a1c2d..10b157a6d73e 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1705,6 +1705,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_skc_to_udp6_sock_proto; case BPF_FUNC_skc_to_unix_sock: return &bpf_skc_to_unix_sock_proto; + case BPF_FUNC_skc_to_mptcp_sock: + return &bpf_skc_to_mptcp_sock_proto; case BPF_FUNC_sk_storage_get: return &bpf_sk_storage_get_tracing_proto; case BPF_FUNC_sk_storage_delete: diff --git a/net/core/filter.c b/net/core/filter.c index fe0da529d00f..5af58eb48587 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -78,6 +78,7 @@ #include #include #include +#include static const struct bpf_func_proto * bpf_sk_base_func_proto(enum bpf_func_id func_id); @@ -11281,6 +11282,20 @@ const struct bpf_func_proto bpf_skc_to_unix_sock_proto = { .ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_UNIX], }; +BPF_CALL_1(bpf_skc_to_mptcp_sock, struct sock *, sk) +{ + BTF_TYPE_EMIT(struct mptcp_sock); + return (unsigned long)bpf_mptcp_sock_from_subflow(sk); +} + +const struct bpf_func_proto bpf_skc_to_mptcp_sock_proto = { + .func = bpf_skc_to_mptcp_sock, + .gpl_only = false, + .ret_type = RET_PTR_TO_BTF_ID_OR_NULL, + .arg1_type = ARG_PTR_TO_SOCK_COMMON, + .ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_MPTCP], +}; + BPF_CALL_1(bpf_sock_from_file, struct file *, file) { return (unsigned long)sock_from_file(file); @@ -11323,6 +11338,9 @@ bpf_sk_base_func_proto(enum bpf_func_id func_id) case BPF_FUNC_skc_to_unix_sock: func = &bpf_skc_to_unix_sock_proto; break; + case BPF_FUNC_skc_to_mptcp_sock: + func = &bpf_skc_to_mptcp_sock_proto; + break; case BPF_FUNC_ktime_get_coarse_ns: return &bpf_ktime_get_coarse_ns_proto; default: diff --git a/net/mptcp/Makefile b/net/mptcp/Makefile index e54daceac58b..99dddf08ca73 100644 --- a/net/mptcp/Makefile +++ b/net/mptcp/Makefile @@ -10,3 +10,5 @@ obj-$(CONFIG_INET_MPTCP_DIAG) += mptcp_diag.o mptcp_crypto_test-objs := crypto_test.o mptcp_token_test-objs := token_test.o obj-$(CONFIG_MPTCP_KUNIT_TEST) += mptcp_crypto_test.o mptcp_token_test.o + +obj-$(CONFIG_BPF_SYSCALL) += bpf.o diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c new file mode 100644 index 000000000000..5a0a84ad94af --- /dev/null +++ b/net/mptcp/bpf.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Multipath TCP + * + * Copyright (c) 2020, Tessares SA. + * Copyright (c) 2022, SUSE. + * + * Author: Nicolas Rybowski + */ + +#define pr_fmt(fmt) "MPTCP: " fmt + +#include +#include "protocol.h" + +struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) +{ + if (sk && sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk)) + return mptcp_sk(mptcp_subflow_ctx(sk)->conn); + + return NULL; +} diff --git a/scripts/bpf_doc.py b/scripts/bpf_doc.py index 096625242475..d5452f7eb996 100755 --- a/scripts/bpf_doc.py +++ b/scripts/bpf_doc.py @@ -633,6 +633,7 @@ class PrinterHelpers(Printer): 'struct socket', 'struct file', 'struct bpf_timer', + 'struct mptcp_sock', ] known_types = { '...', @@ -682,6 +683,7 @@ class PrinterHelpers(Printer): 'struct socket', 'struct file', 'struct bpf_timer', + 'struct mptcp_sock', } mapped_types = { 'u8': '__u8', diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 0210f85131b3..56688bee20d9 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5172,6 +5172,12 @@ union bpf_attr { * Return * Map value associated to *key* on *cpu*, or **NULL** if no entry * was found or *cpu* is invalid. + * + * struct mptcp_sock *bpf_skc_to_mptcp_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *mptcp_sock* pointer. + * Return + * *sk* if casting is valid, or **NULL** otherwise. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5370,6 +5376,7 @@ union bpf_attr { FN(ima_file_hash), \ FN(kptr_xchg), \ FN(map_lookup_percpu_elem), \ + FN(skc_to_mptcp_sock), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper -- cgit v1.2.3