selftests/bpf: Selftest for sys_sendmsg hooks (04b6ab73) · Commits · 戴 / test

tools/testing/selftests/bpf/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -34,7 +34,7 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test
		sockmap_tcp_msg_prog.o connect4_prog.o connect6_prog.o test_adjust_tail.o \
		test_btf_haskv.o test_btf_nokv.o test_sockmap_kern.o test_tunnel_kern.o \
		test_get_stack_rawtp.o test_sockmap_kern.o test_sockhash_kern.o \
		test_lwt_seg6local.o
		test_lwt_seg6local.o sendmsg4_prog.o sendmsg6_prog.o

		# Order correspond to 'make run_tests' order
		TEST_PROGS := test_kmod.sh \

tools/testing/selftests/bpf/sendmsg4_prog.c

0 → 100644

+49 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		// Copyright (c) 2018 Facebook

		#include <linux/stddef.h>
		#include <linux/bpf.h>
		#include <sys/socket.h>

		#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";

tools/testing/selftests/bpf/sendmsg6_prog.c

0 → 100644

+60 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		// Copyright (c) 2018 Facebook

		#include <linux/stddef.h>
		#include <linux/bpf.h>
		#include <sys/socket.h>

		#include "bpf_helpers.h"
		#include "bpf_endian.h"

		#define SRC_REWRITE_IP6_0 0
		#define SRC_REWRITE_IP6_1 0
		#define SRC_REWRITE_IP6_2 0
		#define SRC_REWRITE_IP6_3 6

		#define DST_REWRITE_IP6_0 0
		#define DST_REWRITE_IP6_1 0
		#define DST_REWRITE_IP6_2 0
		#define DST_REWRITE_IP6_3 1

		#define DST_REWRITE_PORT6 6666

		int _version SEC("version") = 1;

		SEC("cgroup/sendmsg6")
		int sendmsg_v6_prog(struct bpf_sock_addr *ctx)
		{
		if (ctx->type != SOCK_DGRAM)
		return 0;

		/* Rewrite source. */
		if (ctx->msg_src_ip6[3] == bpf_htonl(1) \|\|
		ctx->msg_src_ip6[3] == bpf_htonl(0)) {
		ctx->msg_src_ip6[0] = bpf_htonl(SRC_REWRITE_IP6_0);
		ctx->msg_src_ip6[1] = bpf_htonl(SRC_REWRITE_IP6_1);
		ctx->msg_src_ip6[2] = bpf_htonl(SRC_REWRITE_IP6_2);
		ctx->msg_src_ip6[3] = bpf_htonl(SRC_REWRITE_IP6_3);
		} else {
		/* Unexpected source. Reject sendmsg. */
		return 0;
		}

		/* Rewrite destination. */
		if ((ctx->user_ip6[0] & 0xFFFF) == bpf_htons(0xFACE) &&
		ctx->user_ip6[0] >> 16 == bpf_htons(0xB00C)) {
		ctx->user_ip6[0] = bpf_htonl(DST_REWRITE_IP6_0);
		ctx->user_ip6[1] = bpf_htonl(DST_REWRITE_IP6_1);
		ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_2);
		ctx->user_ip6[3] = bpf_htonl(DST_REWRITE_IP6_3);

		ctx->user_port = bpf_htons(DST_REWRITE_PORT6);
		} else {
		/* Unexpected destination. Reject sendmsg. */
		return 0;
		}

		return 1;
		}

		char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/test_sock_addr.c

+518 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0
		// Copyright (c) 2018 Facebook

		#define _GNU_SOURCE

		#include <stdio.h>
		#include <stdlib.h>
		#include <unistd.h>

		#include <arpa/inet.h>
		#include <netinet/in.h>
		#include <sys/types.h>
		#include <sys/select.h>
		#include <sys/socket.h>

		#include <linux/filter.h>
		@@ -17,6 +21,10 @@
		#include "cgroup_helpers.h"
		#include "bpf_rlimit.h"

		#ifndef ENOTSUPP
		# define ENOTSUPP 524
		#endif

		#ifndef ARRAY_SIZE
		# define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
		#endif
		@@ -24,15 +32,20 @@
		#define CG_PATH "/foo"
		#define CONNECT4_PROG_PATH "./connect4_prog.o"
		#define CONNECT6_PROG_PATH "./connect6_prog.o"
		#define SENDMSG4_PROG_PATH "./sendmsg4_prog.o"
		#define SENDMSG6_PROG_PATH "./sendmsg6_prog.o"

		#define SERV4_IP "192.168.1.254"
		#define SERV4_REWRITE_IP "127.0.0.1"
		#define SRC4_IP "172.16.0.1"
		#define SRC4_REWRITE_IP "127.0.0.4"
		#define SERV4_PORT 4040
		#define SERV4_REWRITE_PORT 4444

		#define SERV6_IP "face:b00c:1234:5678::abcd"
		#define SERV6_REWRITE_IP "::1"
		#define SERV6_V4MAPPED_IP "::ffff:192.168.0.4"
		#define SRC6_IP "::1"
		#define SRC6_REWRITE_IP "::6"
		#define SERV6_PORT 6060
		#define SERV6_REWRITE_PORT 6666
		@@ -65,6 +78,8 @@ struct sock_addr_test {
		enum {
		LOAD_REJECT,
		ATTACH_REJECT,
		SYSCALL_EPERM,
		SYSCALL_ENOTSUPP,
		SUCCESS,
		} expected_result;
		};
		@@ -73,6 +88,12 @@ static int bind4_prog_load(const struct sock_addr_test *test);
		static int bind6_prog_load(const struct sock_addr_test *test);
		static int connect4_prog_load(const struct sock_addr_test *test);
		static int connect6_prog_load(const struct sock_addr_test *test);
		static int sendmsg_deny_prog_load(const struct sock_addr_test *test);
		static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test);
		static int sendmsg4_rw_c_prog_load(const struct sock_addr_test *test);
		static int sendmsg6_rw_asm_prog_load(const struct sock_addr_test *test);
		static int sendmsg6_rw_c_prog_load(const struct sock_addr_test *test);
		static int sendmsg6_rw_v4mapped_prog_load(const struct sock_addr_test *test);

		static struct sock_addr_test tests[] = {
		/* bind */
		@@ -302,6 +323,162 @@ static struct sock_addr_test tests[] = {
		SRC6_REWRITE_IP,
		SUCCESS,
		},

		/* sendmsg */
		{
		"sendmsg4: load prog with wrong expected attach type",
		sendmsg4_rw_asm_prog_load,
		BPF_CGROUP_UDP6_SENDMSG,
		BPF_CGROUP_UDP4_SENDMSG,
		AF_INET,
		SOCK_DGRAM,
		NULL,
		0,
		NULL,
		0,
		NULL,
		LOAD_REJECT,
		},
		{
		"sendmsg4: attach prog with wrong attach type",
		sendmsg4_rw_asm_prog_load,
		BPF_CGROUP_UDP4_SENDMSG,
		BPF_CGROUP_UDP6_SENDMSG,
		AF_INET,
		SOCK_DGRAM,
		NULL,
		0,
		NULL,
		0,
		NULL,
		ATTACH_REJECT,
		},
		{
		"sendmsg4: rewrite IP & port (asm)",
		sendmsg4_rw_asm_prog_load,
		BPF_CGROUP_UDP4_SENDMSG,
		BPF_CGROUP_UDP4_SENDMSG,
		AF_INET,
		SOCK_DGRAM,
		SERV4_IP,
		SERV4_PORT,
		SERV4_REWRITE_IP,
		SERV4_REWRITE_PORT,
		SRC4_REWRITE_IP,
		SUCCESS,
		},
		{
		"sendmsg4: rewrite IP & port (C)",
		sendmsg4_rw_c_prog_load,
		BPF_CGROUP_UDP4_SENDMSG,
		BPF_CGROUP_UDP4_SENDMSG,
		AF_INET,
		SOCK_DGRAM,
		SERV4_IP,
		SERV4_PORT,
		SERV4_REWRITE_IP,
		SERV4_REWRITE_PORT,
		SRC4_REWRITE_IP,
		SUCCESS,
		},
		{
		"sendmsg4: deny call",
		sendmsg_deny_prog_load,
		BPF_CGROUP_UDP4_SENDMSG,
		BPF_CGROUP_UDP4_SENDMSG,
		AF_INET,
		SOCK_DGRAM,
		SERV4_IP,
		SERV4_PORT,
		SERV4_REWRITE_IP,
		SERV4_REWRITE_PORT,
		SRC4_REWRITE_IP,
		SYSCALL_EPERM,
		},
		{
		"sendmsg6: load prog with wrong expected attach type",
		sendmsg6_rw_asm_prog_load,
		BPF_CGROUP_UDP4_SENDMSG,
		BPF_CGROUP_UDP6_SENDMSG,
		AF_INET6,
		SOCK_DGRAM,
		NULL,
		0,
		NULL,
		0,
		NULL,
		LOAD_REJECT,
		},
		{
		"sendmsg6: attach prog with wrong attach type",
		sendmsg6_rw_asm_prog_load,
		BPF_CGROUP_UDP6_SENDMSG,
		BPF_CGROUP_UDP4_SENDMSG,
		AF_INET6,
		SOCK_DGRAM,
		NULL,
		0,
		NULL,
		0,
		NULL,
		ATTACH_REJECT,
		},
		{
		"sendmsg6: rewrite IP & port (asm)",
		sendmsg6_rw_asm_prog_load,
		BPF_CGROUP_UDP6_SENDMSG,
		BPF_CGROUP_UDP6_SENDMSG,
		AF_INET6,
		SOCK_DGRAM,
		SERV6_IP,
		SERV6_PORT,
		SERV6_REWRITE_IP,
		SERV6_REWRITE_PORT,
		SRC6_REWRITE_IP,
		SUCCESS,
		},
		{
		"sendmsg6: rewrite IP & port (C)",
		sendmsg6_rw_c_prog_load,
		BPF_CGROUP_UDP6_SENDMSG,
		BPF_CGROUP_UDP6_SENDMSG,
		AF_INET6,
		SOCK_DGRAM,
		SERV6_IP,
		SERV6_PORT,
		SERV6_REWRITE_IP,
		SERV6_REWRITE_PORT,
		SRC6_REWRITE_IP,
		SUCCESS,
		},
		{
		"sendmsg6: IPv4-mapped IPv6",
		sendmsg6_rw_v4mapped_prog_load,
		BPF_CGROUP_UDP6_SENDMSG,
		BPF_CGROUP_UDP6_SENDMSG,
		AF_INET6,
		SOCK_DGRAM,
		SERV6_IP,
		SERV6_PORT,
		SERV6_REWRITE_IP,
		SERV6_REWRITE_PORT,
		SRC6_REWRITE_IP,
		SYSCALL_ENOTSUPP,
		},
		{
		"sendmsg6: deny call",
		sendmsg_deny_prog_load,
		BPF_CGROUP_UDP6_SENDMSG,
		BPF_CGROUP_UDP6_SENDMSG,
		AF_INET6,
		SOCK_DGRAM,
		SERV6_IP,
		SERV6_PORT,
		SERV6_REWRITE_IP,
		SERV6_REWRITE_PORT,
		SRC6_REWRITE_IP,
		SYSCALL_EPERM,
		},
		};

		static int mk_sockaddr(int domain, const char *ip, unsigned short port,
		@@ -540,6 +717,141 @@ static int connect6_prog_load(const struct sock_addr_test *test)
		return load_path(test, CONNECT6_PROG_PATH);
		}

		static int sendmsg_deny_prog_load(const struct sock_addr_test *test)
		{
		struct bpf_insn insns[] = {
		/* return 0 */
		BPF_MOV64_IMM(BPF_REG_0, 0),
		BPF_EXIT_INSN(),
		};
		return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
		}

		static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test)
		{
		struct sockaddr_in dst4_rw_addr;
		struct in_addr src4_rw_ip;

		if (inet_pton(AF_INET, SRC4_REWRITE_IP, (void *)&src4_rw_ip) != 1) {
		log_err("Invalid IPv4: %s", SRC4_REWRITE_IP);
		return -1;
		}

		if (mk_sockaddr(AF_INET, SERV4_REWRITE_IP, SERV4_REWRITE_PORT,
		(struct sockaddr *)&dst4_rw_addr,
		sizeof(dst4_rw_addr)) == -1)
		return -1;

		struct bpf_insn insns[] = {
		BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),

		/* if (sk.family == AF_INET && */
		BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
		offsetof(struct bpf_sock_addr, family)),
		BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET, 8),

		/* sk.type == SOCK_DGRAM) { */
		BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
		offsetof(struct bpf_sock_addr, type)),
		BPF_JMP_IMM(BPF_JNE, BPF_REG_7, SOCK_DGRAM, 6),

		/* msg_src_ip4 = src4_rw_ip */
		BPF_MOV32_IMM(BPF_REG_7, src4_rw_ip.s_addr),
		BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
		offsetof(struct bpf_sock_addr, msg_src_ip4)),

		/* user_ip4 = dst4_rw_addr.sin_addr */
		BPF_MOV32_IMM(BPF_REG_7, dst4_rw_addr.sin_addr.s_addr),
		BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
		offsetof(struct bpf_sock_addr, user_ip4)),

		/* user_port = dst4_rw_addr.sin_port */
		BPF_MOV32_IMM(BPF_REG_7, dst4_rw_addr.sin_port),
		BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
		offsetof(struct bpf_sock_addr, user_port)),
		/* } */

		/* return 1 */
		BPF_MOV64_IMM(BPF_REG_0, 1),
		BPF_EXIT_INSN(),
		};

		return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
		}

		static int sendmsg4_rw_c_prog_load(const struct sock_addr_test *test)
		{
		return load_path(test, SENDMSG4_PROG_PATH);
		}

		static int sendmsg6_rw_dst_asm_prog_load(const struct sock_addr_test *test,
		const char *rw_dst_ip)
		{
		struct sockaddr_in6 dst6_rw_addr;
		struct in6_addr src6_rw_ip;

		if (inet_pton(AF_INET6, SRC6_REWRITE_IP, (void *)&src6_rw_ip) != 1) {
		log_err("Invalid IPv6: %s", SRC6_REWRITE_IP);
		return -1;
		}

		if (mk_sockaddr(AF_INET6, rw_dst_ip, SERV6_REWRITE_PORT,
		(struct sockaddr *)&dst6_rw_addr,
		sizeof(dst6_rw_addr)) == -1)
		return -1;

		struct bpf_insn insns[] = {
		BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),

		/* if (sk.family == AF_INET6) { */
		BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
		offsetof(struct bpf_sock_addr, family)),
		BPF_JMP_IMM(BPF_JNE, BPF_REG_7, AF_INET6, 18),

		#define STORE_IPV6_WORD_N(DST, SRC, N) \
		BPF_MOV32_IMM(BPF_REG_7, SRC[N]), \
		BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7, \
		offsetof(struct bpf_sock_addr, DST[N]))

		#define STORE_IPV6(DST, SRC) \
		STORE_IPV6_WORD_N(DST, SRC, 0), \
		STORE_IPV6_WORD_N(DST, SRC, 1), \
		STORE_IPV6_WORD_N(DST, SRC, 2), \
		STORE_IPV6_WORD_N(DST, SRC, 3)

		STORE_IPV6(msg_src_ip6, src6_rw_ip.s6_addr32),
		STORE_IPV6(user_ip6, dst6_rw_addr.sin6_addr.s6_addr32),

		/* user_port = dst6_rw_addr.sin6_port */
		BPF_MOV32_IMM(BPF_REG_7, dst6_rw_addr.sin6_port),
		BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_7,
		offsetof(struct bpf_sock_addr, user_port)),

		/* } */

		/* return 1 */
		BPF_MOV64_IMM(BPF_REG_0, 1),
		BPF_EXIT_INSN(),
		};

		return load_insns(test, insns, sizeof(insns) / sizeof(struct bpf_insn));
		}

		static int sendmsg6_rw_asm_prog_load(const struct sock_addr_test *test)
		{
		return sendmsg6_rw_dst_asm_prog_load(test, SERV6_REWRITE_IP);
		}

		static int sendmsg6_rw_v4mapped_prog_load(const struct sock_addr_test *test)
		{
		return sendmsg6_rw_dst_asm_prog_load(test, SERV6_V4MAPPED_IP);
		}

		static int sendmsg6_rw_c_prog_load(const struct sock_addr_test *test)
		{
		return load_path(test, SENDMSG6_PROG_PATH);
		}

		static int cmp_addr(const struct sockaddr_storage *addr1,
		const struct sockaddr_storage *addr2, int cmp_port)
		{
		@@ -656,6 +968,135 @@ out:
		return fd;
		}

		int init_pktinfo(int domain, struct cmsghdr *cmsg)
		{
		struct in6_pktinfo *pktinfo6;
		struct in_pktinfo *pktinfo4;

		if (domain == AF_INET) {
		cmsg->cmsg_level = SOL_IP;
		cmsg->cmsg_type = IP_PKTINFO;
		cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
		pktinfo4 = (struct in_pktinfo *)CMSG_DATA(cmsg);
		memset(pktinfo4, 0, sizeof(struct in_pktinfo));
		if (inet_pton(domain, SRC4_IP,
		(void *)&pktinfo4->ipi_spec_dst) != 1)
		return -1;
		} else if (domain == AF_INET6) {
		cmsg->cmsg_level = SOL_IPV6;
		cmsg->cmsg_type = IPV6_PKTINFO;
		cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
		pktinfo6 = (struct in6_pktinfo *)CMSG_DATA(cmsg);
		memset(pktinfo6, 0, sizeof(struct in6_pktinfo));
		if (inet_pton(domain, SRC6_IP,
		(void *)&pktinfo6->ipi6_addr) != 1)
		return -1;
		} else {
		return -1;
		}

		return 0;
		}

		static int sendmsg_to_server(const struct sockaddr_storage *addr,
		socklen_t addr_len, int set_cmsg, int *syscall_err)
		{
		union {
		char buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
		struct cmsghdr align;
		} control6;
		union {
		char buf[CMSG_SPACE(sizeof(struct in_pktinfo))];
		struct cmsghdr align;
		} control4;
		struct msghdr hdr;
		struct iovec iov;
		char data = 'a';
		int domain;
		int fd = -1;

		domain = addr->ss_family;

		if (domain != AF_INET && domain != AF_INET6) {
		log_err("Unsupported address family");
		goto err;
		}

		fd = socket(domain, SOCK_DGRAM, 0);
		if (fd == -1) {
		log_err("Failed to create client socket");
		goto err;
		}

		memset(&iov, 0, sizeof(iov));
		iov.iov_base = &data;
		iov.iov_len = sizeof(data);

		memset(&hdr, 0, sizeof(hdr));
		hdr.msg_name = (void *)addr;
		hdr.msg_namelen = addr_len;
		hdr.msg_iov = &iov;
		hdr.msg_iovlen = 1;

		if (set_cmsg) {
		if (domain == AF_INET) {
		hdr.msg_control = &control4;
		hdr.msg_controllen = sizeof(control4.buf);
		} else if (domain == AF_INET6) {
		hdr.msg_control = &control6;
		hdr.msg_controllen = sizeof(control6.buf);
		}
		if (init_pktinfo(domain, CMSG_FIRSTHDR(&hdr))) {
		log_err("Fail to init pktinfo");
		goto err;
		}
		}

		if (sendmsg(fd, &hdr, 0) != sizeof(data)) {
		log_err("Fail to send message to server");
		*syscall_err = errno;
		goto err;
		}

		goto out;
		err:
		close(fd);
		fd = -1;
		out:
		return fd;
		}

		static int recvmsg_from_client(int sockfd, struct sockaddr_storage *src_addr)
		{
		struct timeval tv;
		struct msghdr hdr;
		struct iovec iov;
		char data[64];
		fd_set rfds;

		FD_ZERO(&rfds);
		FD_SET(sockfd, &rfds);

		tv.tv_sec = 2;
		tv.tv_usec = 0;

		if (select(sockfd + 1, &rfds, NULL, NULL, &tv) <= 0 \|\|
		!FD_ISSET(sockfd, &rfds))
		return -1;

		memset(&iov, 0, sizeof(iov));
		iov.iov_base = data;
		iov.iov_len = sizeof(data);

		memset(&hdr, 0, sizeof(hdr));
		hdr.msg_name = src_addr;
		hdr.msg_namelen = sizeof(struct sockaddr_storage);
		hdr.msg_iov = &iov;
		hdr.msg_iovlen = 1;

		return recvmsg(sockfd, &hdr, 0);
		}

		static int init_addrs(const struct sock_addr_test *test,
		struct sockaddr_storage *requested_addr,
		struct sockaddr_storage *expected_addr,
		@@ -753,6 +1194,69 @@ out:
		return err;
		}

		static int run_sendmsg_test_case(const struct sock_addr_test *test)
		{
		socklen_t addr_len = sizeof(struct sockaddr_storage);
		struct sockaddr_storage expected_src_addr;
		struct sockaddr_storage requested_addr;
		struct sockaddr_storage expected_addr;
		struct sockaddr_storage real_src_addr;
		int clientfd = -1;
		int servfd = -1;
		int set_cmsg;
		int err = 0;

		if (test->type != SOCK_DGRAM)
		goto err;

		if (init_addrs(test, &requested_addr, &expected_addr,
		&expected_src_addr))
		goto err;

		/* Prepare server to sendmsg to */
		servfd = start_server(test->type, &expected_addr, addr_len);
		if (servfd == -1)
		goto err;

		for (set_cmsg = 0; set_cmsg <= 1; ++set_cmsg) {
		if (clientfd >= 0)
		close(clientfd);

		clientfd = sendmsg_to_server(&requested_addr, addr_len,
		set_cmsg, &err);
		if (err)
		goto out;
		else if (clientfd == -1)
		goto err;

		/* Try to receive message on server instead of using
		* getpeername(2) on client socket, to check that client's
		* destination address was rewritten properly, since
		* getpeername(2) doesn't work with unconnected datagram
		* sockets.
		*
		* Get source address from recvmsg(2) as well to make sure
		* source was rewritten properly: getsockname(2) can't be used
		* since socket is unconnected and source defined for one
		* specific packet may differ from the one used by default and
		* returned by getsockname(2).
		*/
		if (recvmsg_from_client(servfd, &real_src_addr) == -1)
		goto err;

		if (cmp_addr(&real_src_addr, &expected_src_addr, /cmp_port/0))
		goto err;
		}

		goto out;
		err:
		err = -1;
		out:
		close(clientfd);
		close(servfd);
		return err;
		}

		static int run_test_case(int cgfd, const struct sock_addr_test *test)
		{
		int progfd = -1;
		@@ -784,10 +1288,24 @@ static int run_test_case(int cgfd, const struct sock_addr_test *test)
		case BPF_CGROUP_INET6_CONNECT:
		err = run_connect_test_case(test);
		break;
		case BPF_CGROUP_UDP4_SENDMSG:
		case BPF_CGROUP_UDP6_SENDMSG:
		err = run_sendmsg_test_case(test);
		break;
		default:
		goto err;
		}

		if (test->expected_result == SYSCALL_EPERM && err == EPERM) {
		err = 0; /* error was expected, reset it */
		goto out;
		}

		if (test->expected_result == SYSCALL_ENOTSUPP && err == ENOTSUPP) {
		err = 0; /* error was expected, reset it */
		goto out;
		}

		if (err \|\| test->expected_result != SUCCESS)
		goto err;

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