diff --git a/net/core/filter.c b/net/core/filter.c index 451b0ec7f242..968139f4a1ac 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -11723,3 +11723,66 @@ static int __init bpf_kfunc_init(void) return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &bpf_kfunc_set_xdp); } late_initcall(bpf_kfunc_init); + +/* Disables missing prototype warnings */ +__diag_push(); +__diag_ignore_all("-Wmissing-prototypes", + "Global functions as their definitions will be in vmlinux BTF"); + +/* bpf_sock_destroy: Destroy the given socket with ECONNABORTED error code. + * + * The function expects a non-NULL pointer to a socket, and invokes the + * protocol specific socket destroy handlers. + * + * The helper can only be called from BPF contexts that have acquired the socket + * locks. + * + * Parameters: + * @sock: Pointer to socket to be destroyed + * + * Return: + * On error, may return EPROTONOSUPPORT, EINVAL. + * EPROTONOSUPPORT if protocol specific destroy handler is not supported. + * 0 otherwise + */ +__bpf_kfunc int bpf_sock_destroy(struct sock_common *sock) +{ + struct sock *sk = (struct sock *)sock; + + /* The locking semantics that allow for synchronous execution of the + * destroy handlers are only supported for TCP and UDP. + * Supporting protocols will need to acquire sock lock in the BPF context + * prior to invoking this kfunc. + */ + if (!sk->sk_prot->diag_destroy || (sk->sk_protocol != IPPROTO_TCP && + sk->sk_protocol != IPPROTO_UDP)) + return -EOPNOTSUPP; + + return sk->sk_prot->diag_destroy(sk, ECONNABORTED); +} + +__diag_pop() + +BTF_SET8_START(bpf_sk_iter_kfunc_ids) +BTF_ID_FLAGS(func, bpf_sock_destroy, KF_TRUSTED_ARGS) +BTF_SET8_END(bpf_sk_iter_kfunc_ids) + +static int tracing_iter_filter(const struct bpf_prog *prog, u32 kfunc_id) +{ + if (btf_id_set8_contains(&bpf_sk_iter_kfunc_ids, kfunc_id) && + prog->expected_attach_type != BPF_TRACE_ITER) + return -EACCES; + return 0; +} + +static const struct btf_kfunc_id_set bpf_sk_iter_kfunc_set = { + .owner = THIS_MODULE, + .set = &bpf_sk_iter_kfunc_ids, + .filter = tracing_iter_filter, +}; + +static int init_subsystem(void) +{ + return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &bpf_sk_iter_kfunc_set); +} +late_initcall(init_subsystem); diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 4d6392c16b7a..87a04c3d9425 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4682,8 +4682,10 @@ int tcp_abort(struct sock *sk, int err) return 0; } - /* Don't race with userspace socket closes such as tcp_close. */ - lock_sock(sk); + /* BPF context ensures sock locking. */ + if (!has_current_bpf_ctx()) + /* Don't race with userspace socket closes such as tcp_close. */ + lock_sock(sk); if (sk->sk_state == TCP_LISTEN) { tcp_set_state(sk, TCP_CLOSE); @@ -4707,7 +4709,8 @@ int tcp_abort(struct sock *sk, int err) bh_unlock_sock(sk); local_bh_enable(); tcp_write_queue_purge(sk); - release_sock(sk); + if (!has_current_bpf_ctx()) + release_sock(sk); return 0; } EXPORT_SYMBOL_GPL(tcp_abort); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 6e945199709b..6c2a5f1c63c4 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -3355,7 +3355,7 @@ static struct bpf_iter_reg tcp_reg_info = { .ctx_arg_info_size = 1, .ctx_arg_info = { { offsetof(struct bpf_iter__tcp, sk_common), - PTR_TO_BTF_ID_OR_NULL }, + PTR_TO_BTF_ID_OR_NULL | PTR_TRUSTED }, }, .get_func_proto = bpf_iter_tcp_get_func_proto, .seq_info = &tcp_seq_info, diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 0c999aa5ab30..6893fb867529 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2930,7 +2930,8 @@ EXPORT_SYMBOL(udp_poll); int udp_abort(struct sock *sk, int err) { - lock_sock(sk); + if (!has_current_bpf_ctx()) + lock_sock(sk); /* udp{v6}_destroy_sock() sets it under the sk lock, avoid racing * with close() @@ -2943,7 +2944,8 @@ int udp_abort(struct sock *sk, int err) __udp_disconnect(sk, 0); out: - release_sock(sk); + if (!has_current_bpf_ctx()) + release_sock(sk); return 0; } @@ -3646,7 +3648,7 @@ static struct bpf_iter_reg udp_reg_info = { .ctx_arg_info_size = 1, .ctx_arg_info = { { offsetof(struct bpf_iter__udp, udp_sk), - PTR_TO_BTF_ID_OR_NULL }, + PTR_TO_BTF_ID_OR_NULL | PTR_TRUSTED }, }, .seq_info = &udp_seq_info, };