From 04b6ab731209eac1e130fa00281a29278eca2f57 Mon Sep 17 00:00:00 2001 From: Andrey Ignatov Date: Fri, 25 May 2018 08:55:27 -0700 Subject: selftests/bpf: Selftest for sys_sendmsg hooks Add selftest for BPF_CGROUP_UDP4_SENDMSG and BPF_CGROUP_UDP6_SENDMSG attach types. Try to sendmsg(2) to specific IP:port and test that: * source IP is overridden as expected. * remote IP:port pair is overridden as expected; Both UDPv4 and UDPv6 are tested. Output: # test_sock_addr.sh 2>/dev/null Wait for testing IPv4/IPv6 to become available ... OK ... pre-existing test-cases skipped ... Test case: sendmsg4: load prog with wrong expected attach type .. [PASS] Test case: sendmsg4: attach prog with wrong attach type .. [PASS] Test case: sendmsg4: rewrite IP & port (asm) .. [PASS] Test case: sendmsg4: rewrite IP & port (C) .. [PASS] Test case: sendmsg4: deny call .. [PASS] Test case: sendmsg6: load prog with wrong expected attach type .. [PASS] Test case: sendmsg6: attach prog with wrong attach type .. [PASS] Test case: sendmsg6: rewrite IP & port (asm) .. [PASS] Test case: sendmsg6: rewrite IP & port (C) .. [PASS] Test case: sendmsg6: IPv4-mapped IPv6 .. [PASS] Test case: sendmsg6: deny call .. [PASS] Summary: 27 PASSED, 0 FAILED Signed-off-by: Andrey Ignatov Acked-by: Alexei Starovoitov Acked-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/sendmsg4_prog.c | 49 +++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 tools/testing/selftests/bpf/sendmsg4_prog.c (limited to 'tools/testing/selftests/bpf/sendmsg4_prog.c') diff --git a/tools/testing/selftests/bpf/sendmsg4_prog.c b/tools/testing/selftests/bpf/sendmsg4_prog.c new file mode 100644 index 000000000000..a91536b1c47e --- /dev/null +++ b/tools/testing/selftests/bpf/sendmsg4_prog.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Facebook + +#include +#include +#include + +#include "bpf_helpers.h" +#include "bpf_endian.h" + +#define SRC1_IP4 0xAC100001U /* 172.16.0.1 */ +#define SRC2_IP4 0x00000000U +#define SRC_REWRITE_IP4 0x7f000004U +#define DST_IP4 0xC0A801FEU /* 192.168.1.254 */ +#define DST_REWRITE_IP4 0x7f000001U +#define DST_PORT 4040 +#define DST_REWRITE_PORT4 4444 + +int _version SEC("version") = 1; + +SEC("cgroup/sendmsg4") +int sendmsg_v4_prog(struct bpf_sock_addr *ctx) +{ + if (ctx->type != SOCK_DGRAM) + return 0; + + /* Rewrite source. */ + if (ctx->msg_src_ip4 == bpf_htonl(SRC1_IP4) || + ctx->msg_src_ip4 == bpf_htonl(SRC2_IP4)) { + ctx->msg_src_ip4 = bpf_htonl(SRC_REWRITE_IP4); + } else { + /* Unexpected source. Reject sendmsg. */ + return 0; + } + + /* Rewrite destination. */ + if ((ctx->user_ip4 >> 24) == (bpf_htonl(DST_IP4) >> 24) && + ctx->user_port == bpf_htons(DST_PORT)) { + ctx->user_ip4 = bpf_htonl(DST_REWRITE_IP4); + ctx->user_port = bpf_htons(DST_REWRITE_PORT4); + } else { + /* Unexpected source. Reject sendmsg. */ + return 0; + } + + return 1; +} + +char _license[] SEC("license") = "GPL"; -- cgit v1.2.3