From 1d9c037a898b3c0344cfe5064ba6c482bf9b46b0 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Sun, 24 May 2020 09:51:36 -0700 Subject: bpf, selftests: Add sk_msg helpers load and attach test The test itself is not particularly useful but it encodes a common pattern we have. Namely do a sk storage lookup then depending on data here decide if we need to do more work or alternatively allow packet to PASS. Then if we need to do more work consult task_struct for more information about the running task. Finally based on this additional information drop or pass the data. In this case the suspicious check is not so realisitic but it encodes the general pattern and uses the helpers so we test the workflow. This is a load test to ensure verifier correctly handles this case. Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/159033909665.12355.6166415847337547879.stgit@john-Precision-5820-Tower Signed-off-by: Alexei Starovoitov --- .../selftests/bpf/progs/test_skmsg_load_helpers.c | 47 ++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/test_skmsg_load_helpers.c (limited to 'tools/testing/selftests/bpf/progs') diff --git a/tools/testing/selftests/bpf/progs/test_skmsg_load_helpers.c b/tools/testing/selftests/bpf/progs/test_skmsg_load_helpers.c new file mode 100644 index 000000000000..45e8fc75a739 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_skmsg_load_helpers.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2020 Isovalent, Inc. +#include "vmlinux.h" +#include + +struct { + __uint(type, BPF_MAP_TYPE_SOCKMAP); + __uint(max_entries, 2); + __type(key, __u32); + __type(value, __u64); +} sock_map SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_SOCKHASH); + __uint(max_entries, 2); + __type(key, __u32); + __type(value, __u64); +} sock_hash SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_SK_STORAGE); + __uint(map_flags, BPF_F_NO_PREALLOC); + __type(key, __u32); + __type(value, __u64); +} socket_storage SEC(".maps"); + +SEC("sk_msg") +int prog_msg_verdict(struct sk_msg_md *msg) +{ + struct task_struct *task = (struct task_struct *)bpf_get_current_task(); + int verdict = SK_PASS; + __u32 pid, tpid; + __u64 *sk_stg; + + pid = bpf_get_current_pid_tgid() >> 32; + sk_stg = bpf_sk_storage_get(&socket_storage, msg->sk, 0, BPF_SK_STORAGE_GET_F_CREATE); + if (!sk_stg) + return SK_DROP; + *sk_stg = pid; + bpf_probe_read_kernel(&tpid , sizeof(tpid), &task->tgid); + if (pid != tpid) + verdict = SK_DROP; + bpf_sk_storage_delete(&socket_storage, (void *)msg->sk); + return verdict; +} + +char _license[] SEC("license") = "GPL"; -- cgit v1.2.3