From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97B54CCA481 for ; Fri, 10 Jun 2022 16:59:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349978AbiFJQ67 (ORCPT ); Fri, 10 Jun 2022 12:58:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350029AbiFJQ62 (ORCPT ); Fri, 10 Jun 2022 12:58:28 -0400 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B298326D2 for ; Fri, 10 Jun 2022 09:58:23 -0700 (PDT) Received: by mail-pf1-x44a.google.com with SMTP id p123-20020a625b81000000b0051c31cc75dfso6362232pfb.5 for ; Fri, 10 Jun 2022 09:58:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=XPlVIGcuyESqI9K2qw2nIwxLGEd6+5Om5+wZM5PYzXk=; b=a7efYLh6zKTiEPp2rBqj3EsmNpB/h6KYufSZFitEzGragalQxSp5p/EtWCnBm8A4et TsAR4XcZNQaEmBgyq5MDcJLWHuTx6dlD+Rt9ddLNx/YqDweEjOAVFWb/RdoY0cdii/MI 8WN941IIyE+NKOvmhbQqBDMFKAg/JzjInAPjdIvQc4eYhd6cJ6PuzBNpPImDcaeak911 E7PeqcLY4oaB8aW0pK/RYummkKxCj/O8nksrd7dEyWU99i935cNVRpzqoajBQK9GK7X4 oC0VZqdPPoLmhdcOwg4eRYo1RrixfC5bwW2J0xyYhpTV3EdnkMdo18lOujWdwhdu7mVe NjQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=XPlVIGcuyESqI9K2qw2nIwxLGEd6+5Om5+wZM5PYzXk=; b=kBcwFU1tak4ADL6ZYIQD9Wbr7dDdLmtRyJrRnwymPc2rwfxHwzYT4PuMuIquubdXq9 01c86sm+sQzqORlUw6Tw7OmRQhZr9zCeQAxyPZDfypR4gkJXIgCAwKYypGztMVZK4Hbz SoaRy2zYJqZuHGx3IXrScfeGM06s33oi2SbUNv7wiYRqSp7ZW45WSG8l9GWmixWyvnbU h2qt1HnOQBEj99z16COJeaO42OGzPnVK0WFfdoYkFENTSqlgJovgc89UXj3AUfdcoExo ledCnvFh+vVssJ0Ysgw8FBUjmkcGSv5idvMAZfyLXyaPtcHnUu7iaktCLRvdtZPTgqCD msGQ== X-Gm-Message-State: AOAM533N6sJo6Be19PsfpcmRhYOu82yUHHveqe7AOgUZMR7L2qDwQLmy xqJv7HjGhHOURNyj8XsxZIkhT0BJCVKESlnHqmXQ6k+YEm7PXspZRbS43v6dPCNloUTxaE1jF8O w6GQoFR7xSQoTI0jXRHOykjHDxu5BJ+RbZRghFo53o1uLzgZZKW+xPA== X-Google-Smtp-Source: ABdhPJxAASSWmcQ8ya61FB6iw2Zms+TFac3XGw5Pm94Pwr7NetJXUQ7VkUYCiRQI96OsFnTTl7P39ZY= X-Received: from sdf.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5935]) (user=sdf job=sendgmr) by 2002:a05:6a00:2181:b0:51b:560b:dd30 with SMTP id h1-20020a056a00218100b0051b560bdd30mr60202007pfi.44.1654880302827; Fri, 10 Jun 2022 09:58:22 -0700 (PDT) Date: Fri, 10 Jun 2022 09:58:03 -0700 In-Reply-To: <20220610165803.2860154-1-sdf@google.com> Message-Id: <20220610165803.2860154-11-sdf@google.com> Mime-Version: 1.0 References: <20220610165803.2860154-1-sdf@google.com> X-Mailer: git-send-email 2.36.1.476.g0c4daa206d-goog Subject: [PATCH bpf-next v9 10/10] selftests/bpf: lsm_cgroup functional test From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, Stanislav Fomichev Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Functional test that exercises the following: 1. apply default sk_priority policy 2. permit TX-only AF_PACKET socket 3. cgroup attach/detach/replace 4. reusing trampoline shim Signed-off-by: Stanislav Fomichev --- .../selftests/bpf/prog_tests/lsm_cgroup.c | 277 ++++++++++++++++++ .../selftests/bpf/progs/bpf_tracing_net.h | 1 + .../testing/selftests/bpf/progs/lsm_cgroup.c | 180 ++++++++++++ 3 files changed, 458 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/lsm_cgroup.c create mode 100644 tools/testing/selftests/bpf/progs/lsm_cgroup.c diff --git a/tools/testing/selftests/bpf/prog_tests/lsm_cgroup.c b/tools/testing/selftests/bpf/prog_tests/lsm_cgroup.c new file mode 100644 index 000000000000..a96057ec7dd4 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/lsm_cgroup.c @@ -0,0 +1,277 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include + +#include "lsm_cgroup.skel.h" +#include "cgroup_helpers.h" +#include "network_helpers.h" + +static __u32 query_prog_cnt(int cgroup_fd, const char *attach_func) +{ + LIBBPF_OPTS(bpf_prog_query_opts, p); + static struct btf *btf; + int cnt = 0; + int i; + + ASSERT_OK(bpf_prog_query_opts(cgroup_fd, BPF_LSM_CGROUP, &p), "prog_query"); + + if (!attach_func) + return p.prog_cnt; + + /* When attach_func is provided, count the number of progs that + * attach to the given symbol. + */ + + if (!btf) + btf = btf__load_vmlinux_btf(); + if (!ASSERT_OK(libbpf_get_error(btf), "btf_vmlinux")) + return -1; + + p.prog_ids = malloc(sizeof(u32) * p.prog_cnt); + p.prog_attach_flags = malloc(sizeof(u32) * p.prog_cnt); + ASSERT_OK(bpf_prog_query_opts(cgroup_fd, BPF_LSM_CGROUP, &p), "prog_query"); + + for (i = 0; i < p.prog_cnt; i++) { + struct bpf_prog_info info = {}; + __u32 info_len = sizeof(info); + int fd; + + fd = bpf_prog_get_fd_by_id(p.prog_ids[i]); + ASSERT_GE(fd, 0, "prog_get_fd_by_id"); + ASSERT_OK(bpf_obj_get_info_by_fd(fd, &info, &info_len), "prog_info_by_fd"); + close(fd); + + if (info.attach_btf_id == + btf__find_by_name_kind(btf, attach_func, BTF_KIND_FUNC)) + cnt++; + } + + return cnt; +} + +static void test_lsm_cgroup_functional(void) +{ + DECLARE_LIBBPF_OPTS(bpf_prog_attach_opts, attach_opts); + DECLARE_LIBBPF_OPTS(bpf_link_update_opts, update_opts); + int cgroup_fd, cgroup_fd2, err, fd, prio; + int listen_fd, client_fd, accepted_fd; + struct lsm_cgroup *skel = NULL; + int post_create_prog_fd2 = -1; + int post_create_prog_fd = -1; + int bind_link_fd2 = -1; + int bind_prog_fd2 = -1; + int alloc_prog_fd = -1; + int bind_prog_fd = -1; + int bind_link_fd = -1; + int clone_prog_fd = -1; + socklen_t socklen; + + cgroup_fd = test__join_cgroup("/sock_policy"); + if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup")) + goto close_skel; + + cgroup_fd2 = create_and_get_cgroup("/sock_policy2"); + if (!ASSERT_GE(cgroup_fd2, 0, "create second cgroup")) + goto close_skel; + + skel = lsm_cgroup__open_and_load(); + if (!ASSERT_OK_PTR(skel, "open_and_load")) + goto close_cgroup; + + post_create_prog_fd = bpf_program__fd(skel->progs.socket_post_create); + post_create_prog_fd2 = bpf_program__fd(skel->progs.socket_post_create2); + bind_prog_fd = bpf_program__fd(skel->progs.socket_bind); + bind_prog_fd2 = bpf_program__fd(skel->progs.socket_bind2); + alloc_prog_fd = bpf_program__fd(skel->progs.socket_alloc); + clone_prog_fd = bpf_program__fd(skel->progs.socket_clone); + + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_sk_alloc_security"), 0, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 0, "total prog count"); + err = bpf_prog_attach(alloc_prog_fd, cgroup_fd, BPF_LSM_CGROUP, 0); + if (!ASSERT_OK(err, "attach alloc_prog_fd")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_sk_alloc_security"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 1, "total prog count"); + + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_inet_csk_clone"), 0, "prog count"); + err = bpf_prog_attach(clone_prog_fd, cgroup_fd, BPF_LSM_CGROUP, 0); + if (!ASSERT_OK(err, "attach clone_prog_fd")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_inet_csk_clone"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 2, "total prog count"); + + /* Make sure replacing works. */ + + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_post_create"), 0, "prog count"); + err = bpf_prog_attach(post_create_prog_fd, cgroup_fd, + BPF_LSM_CGROUP, 0); + if (!ASSERT_OK(err, "attach post_create_prog_fd")) + goto close_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_post_create"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 3, "total prog count"); + + attach_opts.replace_prog_fd = post_create_prog_fd; + err = bpf_prog_attach_opts(post_create_prog_fd2, cgroup_fd, + BPF_LSM_CGROUP, &attach_opts); + if (!ASSERT_OK(err, "prog replace post_create_prog_fd")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_post_create"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 3, "total prog count"); + + /* Try the same attach/replace via link API. */ + + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_bind"), 0, "prog count"); + bind_link_fd = bpf_link_create(bind_prog_fd, cgroup_fd, + BPF_LSM_CGROUP, NULL); + if (!ASSERT_GE(bind_link_fd, 0, "link create bind_prog_fd")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_bind"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 4, "total prog count"); + + update_opts.old_prog_fd = bind_prog_fd; + update_opts.flags = BPF_F_REPLACE; + + err = bpf_link_update(bind_link_fd, bind_prog_fd2, &update_opts); + if (!ASSERT_OK(err, "link update bind_prog_fd")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_bind"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 4, "total prog count"); + + /* Attach another instance of bind program to another cgroup. + * This should trigger the reuse of the trampoline shim (two + * programs attaching to the same btf_id). + */ + + ASSERT_EQ(query_prog_cnt(cgroup_fd, "bpf_lsm_socket_bind"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd2, "bpf_lsm_socket_bind"), 0, "prog count"); + bind_link_fd2 = bpf_link_create(bind_prog_fd2, cgroup_fd2, + BPF_LSM_CGROUP, NULL); + if (!ASSERT_GE(bind_link_fd2, 0, "link create bind_prog_fd2")) + goto detach_cgroup; + ASSERT_EQ(query_prog_cnt(cgroup_fd2, "bpf_lsm_socket_bind"), 1, "prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd, NULL), 4, "total prog count"); + ASSERT_EQ(query_prog_cnt(cgroup_fd2, NULL), 1, "total prog count"); + + /* AF_UNIX is prohibited. */ + + fd = socket(AF_UNIX, SOCK_STREAM, 0); + ASSERT_LT(fd, 0, "socket(AF_UNIX)"); + + /* AF_INET6 gets default policy (sk_priority). */ + + fd = socket(AF_INET6, SOCK_STREAM, 0); + if (!ASSERT_GE(fd, 0, "socket(SOCK_STREAM)")) + goto detach_cgroup; + + prio = 0; + socklen = sizeof(prio); + ASSERT_GE(getsockopt(fd, SOL_SOCKET, SO_PRIORITY, &prio, &socklen), 0, + "getsockopt"); + ASSERT_EQ(prio, 123, "sk_priority"); + + close(fd); + + /* TX-only AF_PACKET is allowed. */ + + ASSERT_LT(socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL)), 0, + "socket(AF_PACKET, ..., ETH_P_ALL)"); + + fd = socket(AF_PACKET, SOCK_RAW, 0); + ASSERT_GE(fd, 0, "socket(AF_PACKET, ..., 0)"); + + /* TX-only AF_PACKET can not be rebound. */ + + struct sockaddr_ll sa = { + .sll_family = AF_PACKET, + .sll_protocol = htons(ETH_P_ALL), + }; + ASSERT_LT(bind(fd, (struct sockaddr *)&sa, sizeof(sa)), 0, + "bind(ETH_P_ALL)"); + + close(fd); + + /* Trigger passive open. */ + + listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0); + ASSERT_GE(listen_fd, 0, "start_server"); + client_fd = connect_to_fd(listen_fd, 0); + ASSERT_GE(client_fd, 0, "connect_to_fd"); + accepted_fd = accept(listen_fd, NULL, NULL); + ASSERT_GE(accepted_fd, 0, "accept"); + + prio = 0; + socklen = sizeof(prio); + ASSERT_GE(getsockopt(accepted_fd, SOL_SOCKET, SO_PRIORITY, &prio, &socklen), 0, + "getsockopt"); + ASSERT_EQ(prio, 234, "sk_priority"); + + /* These are replaced and never called. */ + ASSERT_EQ(skel->bss->called_socket_post_create, 0, "called_create"); + ASSERT_EQ(skel->bss->called_socket_bind, 0, "called_bind"); + + /* AF_INET6+SOCK_STREAM + * AF_PACKET+SOCK_RAW + * listen_fd + * client_fd + * accepted_fd + */ + ASSERT_EQ(skel->bss->called_socket_post_create2, 5, "called_create2"); + + /* start_server + * bind(ETH_P_ALL) + */ + ASSERT_EQ(skel->bss->called_socket_bind2, 2, "called_bind2"); + /* Single accept(). */ + ASSERT_EQ(skel->bss->called_socket_clone, 1, "called_clone"); + + /* AF_UNIX+SOCK_STREAM (failed) + * AF_INET6+SOCK_STREAM + * AF_PACKET+SOCK_RAW (failed) + * AF_PACKET+SOCK_RAW + * listen_fd + * client_fd + * accepted_fd + */ + ASSERT_EQ(skel->bss->called_socket_alloc, 7, "called_alloc"); + + /* Make sure other cgroup doesn't trigger the programs. */ + + if (!ASSERT_OK(join_cgroup(""), "join root cgroup")) + goto detach_cgroup; + + fd = socket(AF_INET6, SOCK_STREAM, 0); + if (!ASSERT_GE(fd, 0, "socket(SOCK_STREAM)")) + goto detach_cgroup; + + prio = 0; + socklen = sizeof(prio); + ASSERT_GE(getsockopt(fd, SOL_SOCKET, SO_PRIORITY, &prio, &socklen), 0, + "getsockopt"); + ASSERT_EQ(prio, 0, "sk_priority"); + + close(fd); + +detach_cgroup: + ASSERT_GE(bpf_prog_detach2(post_create_prog_fd2, cgroup_fd, + BPF_LSM_CGROUP), 0, "detach_create"); + close(bind_link_fd); + /* Don't close bind_link_fd2, exercise cgroup release cleanup. */ + ASSERT_GE(bpf_prog_detach2(alloc_prog_fd, cgroup_fd, + BPF_LSM_CGROUP), 0, "detach_alloc"); + ASSERT_GE(bpf_prog_detach2(clone_prog_fd, cgroup_fd, + BPF_LSM_CGROUP), 0, "detach_clone"); + +close_cgroup: + close(cgroup_fd); +close_skel: + lsm_cgroup__destroy(skel); +} + +void test_lsm_cgroup(void) +{ + if (test__start_subtest("functional")) + test_lsm_cgroup_functional(); +} diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h index 1c1289ba5fc5..98dd2c4815f0 100644 --- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h +++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h @@ -8,6 +8,7 @@ #define SOL_SOCKET 1 #define SO_SNDBUF 7 #define __SO_ACCEPTCON (1 << 16) +#define SO_PRIORITY 12 #define SOL_TCP 6 #define TCP_CONGESTION 13 diff --git a/tools/testing/selftests/bpf/progs/lsm_cgroup.c b/tools/testing/selftests/bpf/progs/lsm_cgroup.c new file mode 100644 index 000000000000..89f3b1e961a8 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/lsm_cgroup.c @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "vmlinux.h" +#include "bpf_tracing_net.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +#ifndef AF_PACKET +#define AF_PACKET 17 +#endif + +#ifndef AF_UNIX +#define AF_UNIX 1 +#endif + +#ifndef EPERM +#define EPERM 1 +#endif + +struct { + __uint(type, BPF_MAP_TYPE_CGROUP_STORAGE); + __type(key, __u64); + __type(value, __u64); +} cgroup_storage SEC(".maps"); + +int called_socket_post_create; +int called_socket_post_create2; +int called_socket_bind; +int called_socket_bind2; +int called_socket_alloc; +int called_socket_clone; + +static __always_inline int test_local_storage(void) +{ + __u64 *val; + + val = bpf_get_local_storage(&cgroup_storage, 0); + if (!val) + return 0; + *val += 1; + + return 1; +} + +static __always_inline int real_create(struct socket *sock, int family, + int protocol) +{ + struct sock *sk; + int prio = 123; + + /* Reject non-tx-only AF_PACKET. */ + if (family == AF_PACKET && protocol != 0) + return 0; /* EPERM */ + + sk = sock->sk; + if (!sk) + return 1; + + /* The rest of the sockets get default policy. */ + if (bpf_setsockopt(sk, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 0; /* EPERM */ + + /* Make sure bpf_getsockopt is allowed and works. */ + prio = 0; + if (bpf_getsockopt(sk, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 0; /* EPERM */ + if (prio != 123) + return 0; /* EPERM */ + + /* Can access cgroup local storage. */ + if (!test_local_storage()) + return 0; /* EPERM */ + + return 1; +} + +/* __cgroup_bpf_run_lsm_socket */ +SEC("lsm_cgroup/socket_post_create") +int BPF_PROG(socket_post_create, struct socket *sock, int family, + int type, int protocol, int kern) +{ + called_socket_post_create++; + return real_create(sock, family, protocol); +} + +/* __cgroup_bpf_run_lsm_socket */ +SEC("lsm_cgroup/socket_post_create") +int BPF_PROG(socket_post_create2, struct socket *sock, int family, + int type, int protocol, int kern) +{ + called_socket_post_create2++; + return real_create(sock, family, protocol); +} + +static __always_inline int real_bind(struct socket *sock, + struct sockaddr *address, + int addrlen) +{ + struct sockaddr_ll sa = {}; + + if (sock->sk->__sk_common.skc_family != AF_PACKET) + return 1; + + if (sock->sk->sk_kern_sock) + return 1; + + bpf_probe_read_kernel(&sa, sizeof(sa), address); + if (sa.sll_protocol) + return 0; /* EPERM */ + + /* Can access cgroup local storage. */ + if (!test_local_storage()) + return 0; /* EPERM */ + + return 1; +} + +/* __cgroup_bpf_run_lsm_socket */ +SEC("lsm_cgroup/socket_bind") +int BPF_PROG(socket_bind, struct socket *sock, struct sockaddr *address, + int addrlen) +{ + called_socket_bind++; + return real_bind(sock, address, addrlen); +} + +/* __cgroup_bpf_run_lsm_socket */ +SEC("lsm_cgroup/socket_bind") +int BPF_PROG(socket_bind2, struct socket *sock, struct sockaddr *address, + int addrlen) +{ + called_socket_bind2++; + return real_bind(sock, address, addrlen); +} + +/* __cgroup_bpf_run_lsm_current (via bpf_lsm_current_hooks) */ +SEC("lsm_cgroup/sk_alloc_security") +int BPF_PROG(socket_alloc, struct sock *sk, int family, gfp_t priority) +{ + called_socket_alloc++; + if (family == AF_UNIX) + return 0; /* EPERM */ + + /* Can access cgroup local storage. */ + if (!test_local_storage()) + return 0; /* EPERM */ + + return 1; +} + +/* __cgroup_bpf_run_lsm_sock */ +SEC("lsm_cgroup/inet_csk_clone") +int BPF_PROG(socket_clone, struct sock *newsk, const struct request_sock *req) +{ + int prio = 234; + + called_socket_clone++; + + if (!newsk) + return 1; + + /* Accepted request sockets get a different priority. */ + if (bpf_setsockopt(newsk, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 0; /* EPERM */ + + /* Make sure bpf_getsockopt is allowed and works. */ + prio = 0; + if (bpf_getsockopt(newsk, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio))) + return 0; /* EPERM */ + if (prio != 234) + return 0; /* EPERM */ + + /* Can access cgroup local storage. */ + if (!test_local_storage()) + return 0; /* EPERM */ + + return 1; +} -- 2.36.1.476.g0c4daa206d-goog