From af7ec13833619e17f03aa73a785a2f871da6d66b Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Tue, 23 Jun 2020 16:08:09 -0700 Subject: bpf: Add bpf_skc_to_tcp6_sock() helper The helper is used in tracing programs to cast a socket pointer to a tcp6_sock pointer. The return value could be NULL if the casting is illegal. A new helper return type RET_PTR_TO_BTF_ID_OR_NULL is added so the verifier is able to deduce proper return types for the helper. Different from the previous BTF_ID based helpers, the bpf_skc_to_tcp6_sock() argument can be several possible btf_ids. More specifically, all possible socket data structures with sock_common appearing in the first in the memory layout. This patch only added socket types related to tcp and udp. All possible argument btf_id and return value btf_id for helper bpf_skc_to_tcp6_sock() are pre-calculcated and cached. In the future, it is even possible to precompute these btf_id's at kernel build time. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20200623230809.3988195-1-yhs@fb.com --- include/linux/bpf.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 1e1501ee53ce..c0e38ad07848 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -265,6 +265,7 @@ enum bpf_return_type { RET_PTR_TO_TCP_SOCK_OR_NULL, /* returns a pointer to a tcp_sock or NULL */ RET_PTR_TO_SOCK_COMMON_OR_NULL, /* returns a pointer to a sock_common or NULL */ RET_PTR_TO_ALLOC_MEM_OR_NULL, /* returns a pointer to dynamically allocated memory or NULL */ + RET_PTR_TO_BTF_ID_OR_NULL, /* returns a pointer to a btf_id or NULL */ }; /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs @@ -287,6 +288,12 @@ struct bpf_func_proto { enum bpf_arg_type arg_type[5]; }; int *btf_id; /* BTF ids of arguments */ + bool (*check_btf_id)(u32 btf_id, u32 arg); /* if the argument btf_id is + * valid. Often used if more + * than one btf id is permitted + * for this argument. + */ + int *ret_btf_id; /* return value btf_id */ }; /* bpf_context is intentionally undefined structure. Pointer to bpf_context is @@ -1524,6 +1531,7 @@ static inline bool bpf_map_is_dev_bound(struct bpf_map *map) struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr); void bpf_map_offload_map_free(struct bpf_map *map); +void init_btf_sock_ids(struct btf *btf); #else static inline int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr) @@ -1549,6 +1557,9 @@ static inline struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr) static inline void bpf_map_offload_map_free(struct bpf_map *map) { } +static inline void init_btf_sock_ids(struct btf *btf) +{ +} #endif /* CONFIG_NET && CONFIG_BPF_SYSCALL */ #if defined(CONFIG_BPF_STREAM_PARSER) @@ -1638,6 +1649,7 @@ extern const struct bpf_func_proto bpf_ringbuf_reserve_proto; extern const struct bpf_func_proto bpf_ringbuf_submit_proto; extern const struct bpf_func_proto bpf_ringbuf_discard_proto; extern const struct bpf_func_proto bpf_ringbuf_query_proto; +extern const struct bpf_func_proto bpf_skc_to_tcp6_sock_proto; const struct bpf_func_proto *bpf_tracing_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); -- cgit v1.2.3 From 478cfbdf5f13dfe09cfd0b1cbac821f5e27f6108 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Tue, 23 Jun 2020 16:08:11 -0700 Subject: bpf: Add bpf_skc_to_{tcp, tcp_timewait, tcp_request}_sock() helpers Three more helpers are added to cast a sock_common pointer to an tcp_sock, tcp_timewait_sock or a tcp_request_sock for tracing programs. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20200623230811.3988277-1-yhs@fb.com --- include/linux/bpf.h | 3 ++ include/uapi/linux/bpf.h | 23 +++++++++++++++- kernel/trace/bpf_trace.c | 6 ++++ net/core/filter.c | 62 ++++++++++++++++++++++++++++++++++++++++++ scripts/bpf_helpers_doc.py | 6 ++++ tools/include/uapi/linux/bpf.h | 23 +++++++++++++++- 6 files changed, 121 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index c0e38ad07848..c23998cf6699 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1650,6 +1650,9 @@ extern const struct bpf_func_proto bpf_ringbuf_submit_proto; extern const struct bpf_func_proto bpf_ringbuf_discard_proto; extern const struct bpf_func_proto bpf_ringbuf_query_proto; extern const struct bpf_func_proto bpf_skc_to_tcp6_sock_proto; +extern const struct bpf_func_proto bpf_skc_to_tcp_sock_proto; +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; const struct bpf_func_proto *bpf_tracing_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index e90ad07b291a..b9412ab275f3 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3261,6 +3261,24 @@ union bpf_attr { * Dynamically cast a *sk* pointer to a *tcp6_sock* pointer. * Return * *sk* if casting is valid, or NULL otherwise. + * + * struct tcp_sock *bpf_skc_to_tcp_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *tcp_sock* pointer. + * Return + * *sk* if casting is valid, or NULL otherwise. + * + * struct tcp_timewait_sock *bpf_skc_to_tcp_timewait_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *tcp_timewait_sock* pointer. + * Return + * *sk* if casting is valid, or NULL otherwise. + * + * struct tcp_request_sock *bpf_skc_to_tcp_request_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer. + * Return + * *sk* if casting is valid, or NULL otherwise. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3399,7 +3417,10 @@ union bpf_attr { FN(ringbuf_discard), \ FN(ringbuf_query), \ FN(csum_level), \ - FN(skc_to_tcp6_sock), + FN(skc_to_tcp6_sock), \ + FN(skc_to_tcp_sock), \ + FN(skc_to_tcp_timewait_sock), \ + FN(skc_to_tcp_request_sock), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 2a97a268f533..48d935b0d87c 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1517,6 +1517,12 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_xdp_output_proto; case BPF_FUNC_skc_to_tcp6_sock: return &bpf_skc_to_tcp6_sock_proto; + case BPF_FUNC_skc_to_tcp_sock: + return &bpf_skc_to_tcp_sock_proto; + case BPF_FUNC_skc_to_tcp_timewait_sock: + return &bpf_skc_to_tcp_timewait_sock_proto; + case BPF_FUNC_skc_to_tcp_request_sock: + return &bpf_skc_to_tcp_request_sock_proto; #endif case BPF_FUNC_seq_printf: return prog->expected_attach_type == BPF_TRACE_ITER ? diff --git a/net/core/filter.c b/net/core/filter.c index 176e27d75c51..0b4e5aed7e20 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -74,6 +74,7 @@ #include #include #include +#include /** * sk_filter_trim_cap - run a packet through a socket filter @@ -9307,3 +9308,64 @@ const struct bpf_func_proto bpf_skc_to_tcp6_sock_proto = { .check_btf_id = check_arg_btf_id, .ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_TCP6], }; + +BPF_CALL_1(bpf_skc_to_tcp_sock, struct sock *, sk) +{ + if (sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP) + return (unsigned long)sk; + + return (unsigned long)NULL; +} + +const struct bpf_func_proto bpf_skc_to_tcp_sock_proto = { + .func = bpf_skc_to_tcp_sock, + .gpl_only = false, + .ret_type = RET_PTR_TO_BTF_ID_OR_NULL, + .arg1_type = ARG_PTR_TO_BTF_ID, + .check_btf_id = check_arg_btf_id, + .ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_TCP], +}; + +BPF_CALL_1(bpf_skc_to_tcp_timewait_sock, struct sock *, sk) +{ + if (sk->sk_prot == &tcp_prot && sk->sk_state == TCP_TIME_WAIT) + return (unsigned long)sk; + +#if IS_BUILTIN(CONFIG_IPV6) + if (sk->sk_prot == &tcpv6_prot && sk->sk_state == TCP_TIME_WAIT) + return (unsigned long)sk; +#endif + + return (unsigned long)NULL; +} + +const struct bpf_func_proto bpf_skc_to_tcp_timewait_sock_proto = { + .func = bpf_skc_to_tcp_timewait_sock, + .gpl_only = false, + .ret_type = RET_PTR_TO_BTF_ID_OR_NULL, + .arg1_type = ARG_PTR_TO_BTF_ID, + .check_btf_id = check_arg_btf_id, + .ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_TCP_TW], +}; + +BPF_CALL_1(bpf_skc_to_tcp_request_sock, struct sock *, sk) +{ + if (sk->sk_prot == &tcp_prot && sk->sk_state == TCP_NEW_SYN_RECV) + return (unsigned long)sk; + +#if IS_BUILTIN(CONFIG_IPV6) + if (sk->sk_prot == &tcpv6_prot && sk->sk_state == TCP_NEW_SYN_RECV) + return (unsigned long)sk; +#endif + + return (unsigned long)NULL; +} + +const struct bpf_func_proto bpf_skc_to_tcp_request_sock_proto = { + .func = bpf_skc_to_tcp_request_sock, + .gpl_only = false, + .ret_type = RET_PTR_TO_BTF_ID_OR_NULL, + .arg1_type = ARG_PTR_TO_BTF_ID, + .check_btf_id = check_arg_btf_id, + .ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_TCP_REQ], +}; diff --git a/scripts/bpf_helpers_doc.py b/scripts/bpf_helpers_doc.py index 6c2f64118651..d886657c6aaa 100755 --- a/scripts/bpf_helpers_doc.py +++ b/scripts/bpf_helpers_doc.py @@ -422,6 +422,9 @@ class PrinterHelpers(Printer): 'struct tcphdr', 'struct seq_file', 'struct tcp6_sock', + 'struct tcp_sock', + 'struct tcp_timewait_sock', + 'struct tcp_request_sock', 'struct __sk_buff', 'struct sk_msg_md', @@ -460,6 +463,9 @@ class PrinterHelpers(Printer): 'struct tcphdr', 'struct seq_file', 'struct tcp6_sock', + 'struct tcp_sock', + 'struct tcp_timewait_sock', + 'struct tcp_request_sock', } mapped_types = { 'u8': '__u8', diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index e90ad07b291a..b9412ab275f3 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3261,6 +3261,24 @@ union bpf_attr { * Dynamically cast a *sk* pointer to a *tcp6_sock* pointer. * Return * *sk* if casting is valid, or NULL otherwise. + * + * struct tcp_sock *bpf_skc_to_tcp_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *tcp_sock* pointer. + * Return + * *sk* if casting is valid, or NULL otherwise. + * + * struct tcp_timewait_sock *bpf_skc_to_tcp_timewait_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *tcp_timewait_sock* pointer. + * Return + * *sk* if casting is valid, or NULL otherwise. + * + * struct tcp_request_sock *bpf_skc_to_tcp_request_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer. + * Return + * *sk* if casting is valid, or NULL otherwise. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3399,7 +3417,10 @@ union bpf_attr { FN(ringbuf_discard), \ FN(ringbuf_query), \ FN(csum_level), \ - FN(skc_to_tcp6_sock), + FN(skc_to_tcp6_sock), \ + FN(skc_to_tcp_sock), \ + FN(skc_to_tcp_timewait_sock), \ + FN(skc_to_tcp_request_sock), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call -- cgit v1.2.3 From 0d4fad3e57df2bf61e8ffc8d12a34b1caf9b8835 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Tue, 23 Jun 2020 16:08:15 -0700 Subject: bpf: Add bpf_skc_to_udp6_sock() helper The helper is used in tracing programs to cast a socket pointer to a udp6_sock pointer. The return value could be NULL if the casting is illegal. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Cc: Eric Dumazet Link: https://lore.kernel.org/bpf/20200623230815.3988481-1-yhs@fb.com --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 9 ++++++++- kernel/trace/bpf_trace.c | 2 ++ net/core/filter.c | 22 ++++++++++++++++++++++ scripts/bpf_helpers_doc.py | 2 ++ tools/include/uapi/linux/bpf.h | 9 ++++++++- 6 files changed, 43 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index c23998cf6699..3d2ade703a35 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1653,6 +1653,7 @@ extern const struct bpf_func_proto bpf_skc_to_tcp6_sock_proto; extern const struct bpf_func_proto bpf_skc_to_tcp_sock_proto; 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; const struct bpf_func_proto *bpf_tracing_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index b9412ab275f3..0cb8ec948816 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3279,6 +3279,12 @@ union bpf_attr { * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer. * Return * *sk* if casting is valid, or NULL otherwise. + * + * struct udp6_sock *bpf_skc_to_udp6_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *udp6_sock* pointer. + * Return + * *sk* if casting is valid, or NULL otherwise. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3420,7 +3426,8 @@ union bpf_attr { FN(skc_to_tcp6_sock), \ FN(skc_to_tcp_sock), \ FN(skc_to_tcp_timewait_sock), \ - FN(skc_to_tcp_request_sock), + FN(skc_to_tcp_request_sock), \ + FN(skc_to_udp6_sock), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 48d935b0d87c..5d59dda5f661 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1523,6 +1523,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_skc_to_tcp_timewait_sock_proto; case BPF_FUNC_skc_to_tcp_request_sock: return &bpf_skc_to_tcp_request_sock_proto; + case BPF_FUNC_skc_to_udp6_sock: + return &bpf_skc_to_udp6_sock_proto; #endif case BPF_FUNC_seq_printf: return prog->expected_attach_type == BPF_TRACE_ITER ? diff --git a/net/core/filter.c b/net/core/filter.c index 0b4e5aed7e20..c796e141ea8e 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -9369,3 +9369,25 @@ const struct bpf_func_proto bpf_skc_to_tcp_request_sock_proto = { .check_btf_id = check_arg_btf_id, .ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_TCP_REQ], }; + +BPF_CALL_1(bpf_skc_to_udp6_sock, struct sock *, sk) +{ + /* udp6_sock type is not generated in dwarf and hence btf, + * trigger an explicit type generation here. + */ + BTF_TYPE_EMIT(struct udp6_sock); + if (sk_fullsock(sk) && sk->sk_protocol == IPPROTO_UDP && + sk->sk_type == SOCK_DGRAM && sk->sk_family == AF_INET6) + return (unsigned long)sk; + + return (unsigned long)NULL; +} + +const struct bpf_func_proto bpf_skc_to_udp6_sock_proto = { + .func = bpf_skc_to_udp6_sock, + .gpl_only = false, + .ret_type = RET_PTR_TO_BTF_ID_OR_NULL, + .arg1_type = ARG_PTR_TO_BTF_ID, + .check_btf_id = check_arg_btf_id, + .ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_UDP6], +}; diff --git a/scripts/bpf_helpers_doc.py b/scripts/bpf_helpers_doc.py index d886657c6aaa..6bab40ff442e 100755 --- a/scripts/bpf_helpers_doc.py +++ b/scripts/bpf_helpers_doc.py @@ -425,6 +425,7 @@ class PrinterHelpers(Printer): 'struct tcp_sock', 'struct tcp_timewait_sock', 'struct tcp_request_sock', + 'struct udp6_sock', 'struct __sk_buff', 'struct sk_msg_md', @@ -466,6 +467,7 @@ class PrinterHelpers(Printer): 'struct tcp_sock', 'struct tcp_timewait_sock', 'struct tcp_request_sock', + 'struct udp6_sock', } mapped_types = { 'u8': '__u8', diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index b9412ab275f3..0cb8ec948816 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3279,6 +3279,12 @@ union bpf_attr { * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer. * Return * *sk* if casting is valid, or NULL otherwise. + * + * struct udp6_sock *bpf_skc_to_udp6_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *udp6_sock* pointer. + * Return + * *sk* if casting is valid, or NULL otherwise. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3420,7 +3426,8 @@ union bpf_attr { FN(skc_to_tcp6_sock), \ FN(skc_to_tcp_sock), \ FN(skc_to_tcp_timewait_sock), \ - FN(skc_to_tcp_request_sock), + FN(skc_to_tcp_request_sock), \ + FN(skc_to_udp6_sock), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call -- cgit v1.2.3