tests/netlink_protocol.c - platform/external/strace.git - Git at Google

 /*
  * Check decoding of netlink protocol.
  *
  * Copyright (c) 2014-2017 Dmitry V. Levin <ldv@altlinux.org>
  * Copyright (c) 2016 Fabien Siron <fabien.siron@epita.fr>
  * Copyright (c) 2016-2018 The strace developers.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "tests.h"

 #ifdef HAVE_SYS_XATTR_H

 # include <stdio.h>
 # include <stdlib.h>
 # include <string.h>
 # include <unistd.h>
 # include <sys/xattr.h>
 # include <netinet/in.h>
 # include "netlink.h"
 # include <linux/sock_diag.h>
 # include <linux/netlink_diag.h>

 static void
 send_query(const int fd)
 {
 	static const struct req {
 		struct nlmsghdr nlh;
 		const char magic[4];
 	} c_req = {
 		.nlh = {
 			.nlmsg_len = sizeof(struct req),
 			.nlmsg_type = NLMSG_NOOP,
 			.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST
 		},
 		.magic = "abcd"
 	};
 	struct req *const req = tail_memdup(&c_req, sizeof(c_req));
 	long rc;
 	const char *errstr;

 	/* zero address */
 	rc = sendto(fd, NULL, sizeof(*req), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, NULL, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, (unsigned) sizeof(*req), sprintrc(rc));

 	/* zero length */
 	rc = sendto(fd, req, 0, MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, \"\", 0, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, sprintrc(rc));

 	/* zero address and length */
 	rc = sendto(fd, NULL, 0, MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, NULL, 0, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, sprintrc(rc));

 	/* unfetchable struct nlmsghdr */
 	const void *const efault = tail_alloc(sizeof(struct nlmsghdr) - 1);
 	rc = sendto(fd, efault, sizeof(struct nlmsghdr), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, %p, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, efault, (unsigned) sizeof(struct nlmsghdr), sprintrc(rc));

 	/* whole message length < sizeof(struct nlmsghdr) */
 	rc = sendto(fd, req->magic, sizeof(req->magic), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, \"\\x61\\x62\\x63\\x64\""
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, (unsigned) sizeof(req->magic), sprintrc(rc));

 	/* a single message with some data */
 	rc = sendto(fd, req, sizeof(*req), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, req->nlh.nlmsg_len, NLM_F_DUMP,
 	       (unsigned) sizeof(*req), sprintrc(rc));

 	/* a single message without data */
 	req->nlh.nlmsg_len = sizeof(req->nlh);
 	rc = sendto(fd, &req->nlh, sizeof(req->nlh), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 	       ", seq=0, pid=0}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, req->nlh.nlmsg_len, NLM_F_DUMP,
 	       (unsigned) sizeof(req->nlh), sprintrc(rc));

 	/* nlmsg_len > whole message length */
 	req->nlh.nlmsg_len = sizeof(*req) + 8;
 	rc = sendto(fd, req, sizeof(*req), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, req->nlh.nlmsg_len, NLM_F_DUMP,
 	       (unsigned) sizeof(*req), sprintrc(rc));

 	/* nlmsg_len < sizeof(struct nlmsghdr) */
 	req->nlh.nlmsg_len = 8;
 	rc = sendto(fd, req, sizeof(*req), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 	       ", seq=0, pid=0}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, req->nlh.nlmsg_len, NLM_F_DUMP,
 	       (unsigned) sizeof(*req), sprintrc(rc));

 	/* a sequence of two nlmsg objects */
 	struct reqs {
 		struct req req1;
 		char padding[NLMSG_ALIGN(sizeof(struct req)) - sizeof(struct req)];
 		struct req req2;
 	};
 	TAIL_ALLOC_OBJECT_CONST_PTR(struct reqs, reqs);
 	memcpy(&reqs->req1, &c_req, sizeof(c_req));
 	memcpy(&reqs->req2, &c_req, sizeof(c_req));

 	rc = sendto(fd, reqs, sizeof(*reqs), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
 	       ", {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}]"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP,
 	       reqs->req2.nlh.nlmsg_len, NLM_F_DUMP,
 	       (unsigned) sizeof(*reqs), sprintrc(rc));

 	/* unfetchable second struct nlmsghdr */
 	void *const efault2 = tail_memdup(&reqs->req1, sizeof(reqs->req1));
 	rc = sendto(fd, efault2, sizeof(*reqs), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
 	       ", ... /* %p */], %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP,
 	       &((struct reqs *) efault2)->req2, (unsigned) sizeof(*reqs),
 	       sprintrc(rc));

 	/* message length is not enough for the second struct nlmsghdr */
 	rc = sendto(fd, reqs, sizeof(*reqs) - sizeof(req->nlh), MSG_DONTWAIT,
 		    NULL, 0);
 	errstr = sprintrc(rc);
 	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}, ",
 	       fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP);
 	print_quoted_hex(&reqs->req2.nlh,
 			 sizeof(reqs->req2) - sizeof(req->nlh));
 	printf("], %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       (unsigned) (sizeof(*reqs) - sizeof(req->nlh)), errstr);

 	/* second nlmsg_len < sizeof(struct nlmsghdr) */
 	reqs->req2.nlh.nlmsg_len = 4;
 	rc = sendto(fd, reqs, sizeof(*reqs), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
 	       ", {len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 	       ", seq=0, pid=0}], %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP,
 	       reqs->req2.nlh.nlmsg_len, NLM_F_DUMP,
 	       (unsigned) sizeof(*reqs), sprintrc(rc));

 	/* abbreviated output */
 # define ABBREV_LEN (DEFAULT_STRLEN + 1)
 	const unsigned int msg_len = sizeof(struct nlmsghdr) * ABBREV_LEN;
 	struct nlmsghdr *const msgs = tail_alloc(msg_len);
 	unsigned int i;
 	for (i = 0; i < ABBREV_LEN; ++i) {
 		msgs[i].nlmsg_len = sizeof(*msgs);
 		msgs[i].nlmsg_type = NLMSG_NOOP;
 		msgs[i].nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
 		msgs[i].nlmsg_seq = i;
 		msgs[i].nlmsg_pid = 0;
 	}

 	rc = sendto(fd, msgs, msg_len, MSG_DONTWAIT, NULL, 0);
 	errstr = sprintrc(rc);
 	printf("sendto(%d, [", fd);
 	for (i = 0; i < DEFAULT_STRLEN; ++i) {
 		if (i)
 			printf(", ");
 		printf("{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 		       ", seq=%u, pid=0}",
 		       msgs[i].nlmsg_len, NLM_F_DUMP, msgs[i].nlmsg_seq);
 	}
 	printf(", ...], %u, MSG_DONTWAIT, NULL, 0) = %s\n", msg_len, errstr);
 }

 static void
 test_nlmsgerr(const int fd)
 {
 	struct nlmsgerr *err;
 	struct nlmsghdr *nlh;
 	void *const nlh0 = midtail_alloc(NLMSG_HDRLEN, sizeof(*err) + 4);
 	long rc;

 	/* error message without enough room for the error code */
 	nlh = nlh0;
 	nlh->nlmsg_len = NLMSG_HDRLEN + 4;
 	nlh->nlmsg_type = NLMSG_ERROR;
 	nlh->nlmsg_flags = NLM_F_REQUEST;
 	nlh->nlmsg_seq = 0;
 	nlh->nlmsg_pid = 0;

 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
 	       ", seq=0, pid=0}, %p}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, nlh->nlmsg_len, nlh0 + NLMSG_HDRLEN,
 	       nlh->nlmsg_len, sprintrc(rc));

 	nlh->nlmsg_len = NLMSG_HDRLEN + 2;
 	nlh = nlh0 - 2;
 	memmove(nlh, nlh0, sizeof(*nlh));
 	memcpy(NLMSG_DATA(nlh), "42", 2);

 	rc = sendto(fd, nlh, NLMSG_HDRLEN + 2, MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
 	       ", seq=0, pid=0}, \"\\x34\\x32\"}"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, NLMSG_HDRLEN + 2, NLMSG_HDRLEN + 2, sprintrc(rc));

 	/* error message with room for the error code only */
 	nlh = nlh0 - sizeof(err->error);
 	nlh->nlmsg_len = NLMSG_HDRLEN + sizeof(err->error);
 	nlh->nlmsg_type = NLMSG_ERROR;
 	nlh->nlmsg_flags = NLM_F_REQUEST;
 	nlh->nlmsg_seq = 0;
 	nlh->nlmsg_pid = 0;
 	err = NLMSG_DATA(nlh);
 	err->error = 42;

 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
 	       ", seq=0, pid=0}, {error=42}}, %u, MSG_DONTWAIT, NULL, 0)"
 	       " = %s\n", fd, nlh->nlmsg_len, nlh->nlmsg_len, sprintrc(rc));

 	err->error = -1;

 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
 	       ", seq=0, pid=0}, {error=-EPERM}}, %u, MSG_DONTWAIT, NULL, 0)"
 	       " = %s\n", fd, nlh->nlmsg_len, nlh->nlmsg_len, sprintrc(rc));

 	err->error = -32767;
 	nlh->nlmsg_len += sizeof(err->msg.nlmsg_len);

 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
 	       ", seq=0, pid=0}, {error=-32767, msg=%p}}"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, nlh->nlmsg_len, nlh0 + NLMSG_HDRLEN,
 	       nlh->nlmsg_len, sprintrc(rc));

 	/* error message with room for the error code and a header */
 	nlh = nlh0 - sizeof(*err);
 	nlh->nlmsg_len = NLMSG_HDRLEN + sizeof(*err);
 	nlh->nlmsg_type = NLMSG_ERROR;
 	nlh->nlmsg_flags = NLM_F_REQUEST;
 	nlh->nlmsg_seq = 0;
 	nlh->nlmsg_pid = 0;
 	err = NLMSG_DATA(nlh);
 	err->error = -13;
 	err->msg.nlmsg_len = NLMSG_HDRLEN;
 	err->msg.nlmsg_type = NLMSG_NOOP;
 	err->msg.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
 	err->msg.nlmsg_seq = 42;
 	err->msg.nlmsg_pid = 1234;

 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
 	       ", seq=0, pid=0}, {error=-EACCES"
 	       ", msg={len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 	       ", seq=%u, pid=%u}}}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, nlh->nlmsg_len, err->msg.nlmsg_len, NLM_F_DUMP,
 	       err->msg.nlmsg_seq, err->msg.nlmsg_pid,
 	       nlh->nlmsg_len, sprintrc(rc));

 	/* error message with room for the error code, a header, and some data */
 	nlh = nlh0 - sizeof(*err) - 4;
 	nlh->nlmsg_len = NLMSG_HDRLEN + sizeof(*err) + 4;
 	nlh->nlmsg_type = NLMSG_ERROR;
 	nlh->nlmsg_flags = NLM_F_REQUEST;
 	nlh->nlmsg_seq = 0;
 	nlh->nlmsg_pid = 0;
 	err = NLMSG_DATA(nlh);
 	err->error = -13;
 	err->msg.nlmsg_len = NLMSG_HDRLEN + 4;
 	err->msg.nlmsg_type = NLMSG_NOOP;
 	err->msg.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
 	err->msg.nlmsg_seq = 421;
 	err->msg.nlmsg_pid = 12345;
 	memcpy(NLMSG_DATA(&err->msg), "abcd", 4);

 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
 	       ", seq=0, pid=0}, {error=-EACCES"
 	       ", msg={{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
 	       ", seq=%u, pid=%u}, \"\\x61\\x62\\x63\\x64\"}}}"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, nlh->nlmsg_len, err->msg.nlmsg_len, NLM_F_DUMP,
 	       err->msg.nlmsg_seq, err->msg.nlmsg_pid,
 	       nlh->nlmsg_len, sprintrc(rc));
 }

 static void
 test_nlmsg_done(const int fd)
 {
 	struct nlmsghdr *nlh;
 	const int num = 0xfacefeed;
 	void *const nlh0 = midtail_alloc(NLMSG_HDRLEN, sizeof(num));
 	long rc;

 	/* NLMSG_DONE message without enough room for an integer payload */
 	nlh = nlh0;
 	*nlh = (struct nlmsghdr) {
 		.nlmsg_len = NLMSG_HDRLEN + sizeof(num),
 		.nlmsg_type = NLMSG_DONE,
 		.nlmsg_flags = NLM_F_MULTI
 	};

 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {{len=%u, type=NLMSG_DONE, flags=NLM_F_MULTI"
 	       ", seq=0, pid=0}, %p}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, nlh->nlmsg_len, nlh0 + NLMSG_HDRLEN,
 	       nlh->nlmsg_len, sprintrc(rc));

 	/* NLMSG_DONE message with enough room for an oddly short payload */
 	nlh->nlmsg_len = NLMSG_HDRLEN + 2;
 	nlh = nlh0 - 2;
 	/* Beware of unaligned access to nlh members. */
 	memmove(nlh, nlh0, sizeof(*nlh));
 	memcpy(NLMSG_DATA(nlh), "42", 2);

 	rc = sendto(fd, nlh, NLMSG_HDRLEN + 2, MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {{len=%u, type=NLMSG_DONE, flags=NLM_F_MULTI, seq=0"
 	       ", pid=0}, \"\\x34\\x32\"}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, NLMSG_HDRLEN + 2, NLMSG_HDRLEN + 2, sprintrc(rc));

 	/* NLMSG_DONE message with enough room for an integer payload */
 	nlh = nlh0 - sizeof(num);
 	*nlh = (struct nlmsghdr) {
 		.nlmsg_len = NLMSG_HDRLEN + sizeof(num),
 		.nlmsg_type = NLMSG_DONE,
 		.nlmsg_flags = NLM_F_MULTI
 	};
 	memcpy(NLMSG_DATA(nlh), &num, sizeof(num));

 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {{len=%u, type=NLMSG_DONE, flags=NLM_F_MULTI"
 	       ", seq=0, pid=0}, %d}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, nlh->nlmsg_len, num, nlh->nlmsg_len, sprintrc(rc));
 }

 #if defined NLM_F_CAPPED || defined NLM_F_ACK_TLVS
 static void
 test_ack_flags(const int fd)
 {
 	long rc;
 	struct nlmsghdr nlh = {
 		.nlmsg_len = sizeof(nlh),
 		.nlmsg_type = NLMSG_ERROR,
 	};

 #ifdef NLM_F_CAPPED
 	nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CAPPED,
 	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {len=%u, type=NLMSG_ERROR"
 	       ", flags=NLM_F_REQUEST|NLM_F_CAPPED, seq=0, pid=0}"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
 #endif

 #ifdef NLM_F_ACK_TLVS
 	nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK_TLVS;
 	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {len=%u, type=NLMSG_ERROR"
 	       ", flags=NLM_F_REQUEST|NLM_F_ACK_TLVS, seq=0, pid=0}"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
 #endif

 #if defined NLM_F_CAPPED && defined NLM_F_ACK_TLVS
 	nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CAPPED | NLM_F_ACK_TLVS;
 	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
 	printf("sendto(%d, {len=%u, type=NLMSG_ERROR"
 	       ", flags=NLM_F_REQUEST|NLM_F_CAPPED|NLM_F_ACK_TLVS, seq=0, pid=0}"
 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
 	       fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
 #endif
 }
 #endif

 int main(void)
 {
 	const int fd = create_nl_socket(NETLINK_SOCK_DIAG);

 	char *path;
 	if (asprintf(&path, "/proc/self/fd/%u", fd) < 0)
 		perror_msg_and_fail("asprintf");
 	char buf[256];
 	if (getxattr(path, "system.sockprotoname", buf, sizeof(buf) - 1) < 0)
 		perror_msg_and_skip("getxattr");
 	free(path);

 	send_query(fd);
 	test_nlmsgerr(fd);
 	test_nlmsg_done(fd);
 #if defined NLM_F_CAPPED || defined NLM_F_ACK_TLVS
 	test_ack_flags(fd);
 #endif

 	puts("+++ exited with 0 +++");
 	return 0;
 }

 #else

 SKIP_MAIN_UNDEFINED("HAVE_SYS_XATTR_H")

 #endif
	/*
	* Check decoding of netlink protocol.
	*
	* Copyright (c) 2014-2017 Dmitry V. Levin <ldv@altlinux.org>
	* Copyright (c) 2016 Fabien Siron <fabien.siron@epita.fr>
	* Copyright (c) 2016-2018 The strace developers.
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. The name of the author may not be used to endorse or promote products
	* derived from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "tests.h"

	#ifdef HAVE_SYS_XATTR_H

	# include <stdio.h>
	# include <stdlib.h>
	# include <string.h>
	# include <unistd.h>
	# include <sys/xattr.h>
	# include <netinet/in.h>
	# include "netlink.h"
	# include <linux/sock_diag.h>
	# include <linux/netlink_diag.h>

	static void
	send_query(const int fd)
	{
	static const struct req {
	struct nlmsghdr nlh;
	const char magic[4];
	} c_req = {
	.nlh = {
	.nlmsg_len = sizeof(struct req),
	.nlmsg_type = NLMSG_NOOP,
	.nlmsg_flags = NLM_F_DUMP \| NLM_F_REQUEST
	},
	.magic = "abcd"
	};
	struct req *const req = tail_memdup(&c_req, sizeof(c_req));
	long rc;
	const char *errstr;

	/* zero address */
	rc = sendto(fd, NULL, sizeof(*req), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, NULL, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, (unsigned) sizeof(*req), sprintrc(rc));

	/* zero length */
	rc = sendto(fd, req, 0, MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, \"\", 0, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, sprintrc(rc));

	/* zero address and length */
	rc = sendto(fd, NULL, 0, MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, NULL, 0, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, sprintrc(rc));

	/* unfetchable struct nlmsghdr */
	const void *const efault = tail_alloc(sizeof(struct nlmsghdr) - 1);
	rc = sendto(fd, efault, sizeof(struct nlmsghdr), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, %p, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, efault, (unsigned) sizeof(struct nlmsghdr), sprintrc(rc));

	/* whole message length < sizeof(struct nlmsghdr) */
	rc = sendto(fd, req->magic, sizeof(req->magic), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, \"\\x61\\x62\\x63\\x64\""
	", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, (unsigned) sizeof(req->magic), sprintrc(rc));

	/* a single message with some data */
	rc = sendto(fd, req, sizeof(*req), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
	", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, req->nlh.nlmsg_len, NLM_F_DUMP,
	(unsigned) sizeof(*req), sprintrc(rc));

	/* a single message without data */
	req->nlh.nlmsg_len = sizeof(req->nlh);
	rc = sendto(fd, &req->nlh, sizeof(req->nlh), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=0, pid=0}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, req->nlh.nlmsg_len, NLM_F_DUMP,
	(unsigned) sizeof(req->nlh), sprintrc(rc));

	/* nlmsg_len > whole message length */
	req->nlh.nlmsg_len = sizeof(*req) + 8;
	rc = sendto(fd, req, sizeof(*req), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
	", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, req->nlh.nlmsg_len, NLM_F_DUMP,
	(unsigned) sizeof(*req), sprintrc(rc));

	/* nlmsg_len < sizeof(struct nlmsghdr) */
	req->nlh.nlmsg_len = 8;
	rc = sendto(fd, req, sizeof(*req), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=0, pid=0}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, req->nlh.nlmsg_len, NLM_F_DUMP,
	(unsigned) sizeof(*req), sprintrc(rc));

	/* a sequence of two nlmsg objects */
	struct reqs {
	struct req req1;
	char padding[NLMSG_ALIGN(sizeof(struct req)) - sizeof(struct req)];
	struct req req2;
	};
	TAIL_ALLOC_OBJECT_CONST_PTR(struct reqs, reqs);
	memcpy(&reqs->req1, &c_req, sizeof(c_req));
	memcpy(&reqs->req2, &c_req, sizeof(c_req));

	rc = sendto(fd, reqs, sizeof(*reqs), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
	", {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}]"
	", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP,
	reqs->req2.nlh.nlmsg_len, NLM_F_DUMP,
	(unsigned) sizeof(*reqs), sprintrc(rc));

	/* unfetchable second struct nlmsghdr */
	void *const efault2 = tail_memdup(&reqs->req1, sizeof(reqs->req1));
	rc = sendto(fd, efault2, sizeof(*reqs), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
	", ... /* %p */], %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP,
	&((struct reqs ) efault2)->req2, (unsigned) sizeof(reqs),
	sprintrc(rc));

	/* message length is not enough for the second struct nlmsghdr */
	rc = sendto(fd, reqs, sizeof(*reqs) - sizeof(req->nlh), MSG_DONTWAIT,
	NULL, 0);
	errstr = sprintrc(rc);
	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}, ",
	fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP);
	print_quoted_hex(&reqs->req2.nlh,
	sizeof(reqs->req2) - sizeof(req->nlh));
	printf("], %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	(unsigned) (sizeof(*reqs) - sizeof(req->nlh)), errstr);

	/* second nlmsg_len < sizeof(struct nlmsghdr) */
	reqs->req2.nlh.nlmsg_len = 4;
	rc = sendto(fd, reqs, sizeof(*reqs), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
	", {len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=0, pid=0}], %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP,
	reqs->req2.nlh.nlmsg_len, NLM_F_DUMP,
	(unsigned) sizeof(*reqs), sprintrc(rc));

	/* abbreviated output */
	# define ABBREV_LEN (DEFAULT_STRLEN + 1)
	const unsigned int msg_len = sizeof(struct nlmsghdr) * ABBREV_LEN;
	struct nlmsghdr *const msgs = tail_alloc(msg_len);
	unsigned int i;
	for (i = 0; i < ABBREV_LEN; ++i) {
	msgs[i].nlmsg_len = sizeof(*msgs);
	msgs[i].nlmsg_type = NLMSG_NOOP;
	msgs[i].nlmsg_flags = NLM_F_DUMP \| NLM_F_REQUEST;
	msgs[i].nlmsg_seq = i;
	msgs[i].nlmsg_pid = 0;
	}

	rc = sendto(fd, msgs, msg_len, MSG_DONTWAIT, NULL, 0);
	errstr = sprintrc(rc);
	printf("sendto(%d, [", fd);
	for (i = 0; i < DEFAULT_STRLEN; ++i) {
	if (i)
	printf(", ");
	printf("{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=%u, pid=0}",
	msgs[i].nlmsg_len, NLM_F_DUMP, msgs[i].nlmsg_seq);
	}
	printf(", ...], %u, MSG_DONTWAIT, NULL, 0) = %s\n", msg_len, errstr);
	}

	static void
	test_nlmsgerr(const int fd)
	{
	struct nlmsgerr *err;
	struct nlmsghdr *nlh;
	void const nlh0 = midtail_alloc(NLMSG_HDRLEN, sizeof(err) + 4);
	long rc;

	/* error message without enough room for the error code */
	nlh = nlh0;
	nlh->nlmsg_len = NLMSG_HDRLEN + 4;
	nlh->nlmsg_type = NLMSG_ERROR;
	nlh->nlmsg_flags = NLM_F_REQUEST;
	nlh->nlmsg_seq = 0;
	nlh->nlmsg_pid = 0;

	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
	", seq=0, pid=0}, %p}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, nlh->nlmsg_len, nlh0 + NLMSG_HDRLEN,
	nlh->nlmsg_len, sprintrc(rc));

	nlh->nlmsg_len = NLMSG_HDRLEN + 2;
	nlh = nlh0 - 2;
	memmove(nlh, nlh0, sizeof(*nlh));
	memcpy(NLMSG_DATA(nlh), "42", 2);

	rc = sendto(fd, nlh, NLMSG_HDRLEN + 2, MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
	", seq=0, pid=0}, \"\\x34\\x32\"}"
	", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, NLMSG_HDRLEN + 2, NLMSG_HDRLEN + 2, sprintrc(rc));

	/* error message with room for the error code only */
	nlh = nlh0 - sizeof(err->error);
	nlh->nlmsg_len = NLMSG_HDRLEN + sizeof(err->error);
	nlh->nlmsg_type = NLMSG_ERROR;
	nlh->nlmsg_flags = NLM_F_REQUEST;
	nlh->nlmsg_seq = 0;
	nlh->nlmsg_pid = 0;
	err = NLMSG_DATA(nlh);
	err->error = 42;

	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
	", seq=0, pid=0}, {error=42}}, %u, MSG_DONTWAIT, NULL, 0)"
	" = %s\n", fd, nlh->nlmsg_len, nlh->nlmsg_len, sprintrc(rc));

	err->error = -1;

	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
	", seq=0, pid=0}, {error=-EPERM}}, %u, MSG_DONTWAIT, NULL, 0)"
	" = %s\n", fd, nlh->nlmsg_len, nlh->nlmsg_len, sprintrc(rc));

	err->error = -32767;
	nlh->nlmsg_len += sizeof(err->msg.nlmsg_len);

	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
	", seq=0, pid=0}, {error=-32767, msg=%p}}"
	", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, nlh->nlmsg_len, nlh0 + NLMSG_HDRLEN,
	nlh->nlmsg_len, sprintrc(rc));

	/* error message with room for the error code and a header */
	nlh = nlh0 - sizeof(*err);
	nlh->nlmsg_len = NLMSG_HDRLEN + sizeof(*err);
	nlh->nlmsg_type = NLMSG_ERROR;
	nlh->nlmsg_flags = NLM_F_REQUEST;
	nlh->nlmsg_seq = 0;
	nlh->nlmsg_pid = 0;
	err = NLMSG_DATA(nlh);
	err->error = -13;
	err->msg.nlmsg_len = NLMSG_HDRLEN;
	err->msg.nlmsg_type = NLMSG_NOOP;
	err->msg.nlmsg_flags = NLM_F_DUMP \| NLM_F_REQUEST;
	err->msg.nlmsg_seq = 42;
	err->msg.nlmsg_pid = 1234;

	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
	", seq=0, pid=0}, {error=-EACCES"
	", msg={len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=%u, pid=%u}}}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, nlh->nlmsg_len, err->msg.nlmsg_len, NLM_F_DUMP,
	err->msg.nlmsg_seq, err->msg.nlmsg_pid,
	nlh->nlmsg_len, sprintrc(rc));

	/* error message with room for the error code, a header, and some data */
	nlh = nlh0 - sizeof(*err) - 4;
	nlh->nlmsg_len = NLMSG_HDRLEN + sizeof(*err) + 4;
	nlh->nlmsg_type = NLMSG_ERROR;
	nlh->nlmsg_flags = NLM_F_REQUEST;
	nlh->nlmsg_seq = 0;
	nlh->nlmsg_pid = 0;
	err = NLMSG_DATA(nlh);
	err->error = -13;
	err->msg.nlmsg_len = NLMSG_HDRLEN + 4;
	err->msg.nlmsg_type = NLMSG_NOOP;
	err->msg.nlmsg_flags = NLM_F_DUMP \| NLM_F_REQUEST;
	err->msg.nlmsg_seq = 421;
	err->msg.nlmsg_pid = 12345;
	memcpy(NLMSG_DATA(&err->msg), "abcd", 4);

	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
	", seq=0, pid=0}, {error=-EACCES"
	", msg={{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST\|0x%x"
	", seq=%u, pid=%u}, \"\\x61\\x62\\x63\\x64\"}}}"
	", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, nlh->nlmsg_len, err->msg.nlmsg_len, NLM_F_DUMP,
	err->msg.nlmsg_seq, err->msg.nlmsg_pid,
	nlh->nlmsg_len, sprintrc(rc));
	}

	static void
	test_nlmsg_done(const int fd)
	{
	struct nlmsghdr *nlh;
	const int num = 0xfacefeed;
	void *const nlh0 = midtail_alloc(NLMSG_HDRLEN, sizeof(num));
	long rc;

	/* NLMSG_DONE message without enough room for an integer payload */
	nlh = nlh0;
	*nlh = (struct nlmsghdr) {
	.nlmsg_len = NLMSG_HDRLEN + sizeof(num),
	.nlmsg_type = NLMSG_DONE,
	.nlmsg_flags = NLM_F_MULTI
	};

	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {{len=%u, type=NLMSG_DONE, flags=NLM_F_MULTI"
	", seq=0, pid=0}, %p}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, nlh->nlmsg_len, nlh0 + NLMSG_HDRLEN,
	nlh->nlmsg_len, sprintrc(rc));

	/* NLMSG_DONE message with enough room for an oddly short payload */
	nlh->nlmsg_len = NLMSG_HDRLEN + 2;
	nlh = nlh0 - 2;
	/* Beware of unaligned access to nlh members. */
	memmove(nlh, nlh0, sizeof(*nlh));
	memcpy(NLMSG_DATA(nlh), "42", 2);

	rc = sendto(fd, nlh, NLMSG_HDRLEN + 2, MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {{len=%u, type=NLMSG_DONE, flags=NLM_F_MULTI, seq=0"
	", pid=0}, \"\\x34\\x32\"}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, NLMSG_HDRLEN + 2, NLMSG_HDRLEN + 2, sprintrc(rc));

	/* NLMSG_DONE message with enough room for an integer payload */
	nlh = nlh0 - sizeof(num);
	*nlh = (struct nlmsghdr) {
	.nlmsg_len = NLMSG_HDRLEN + sizeof(num),
	.nlmsg_type = NLMSG_DONE,
	.nlmsg_flags = NLM_F_MULTI
	};
	memcpy(NLMSG_DATA(nlh), &num, sizeof(num));

	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {{len=%u, type=NLMSG_DONE, flags=NLM_F_MULTI"
	", seq=0, pid=0}, %d}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, nlh->nlmsg_len, num, nlh->nlmsg_len, sprintrc(rc));
	}

	#if defined NLM_F_CAPPED \|\| defined NLM_F_ACK_TLVS
	static void
	test_ack_flags(const int fd)
	{
	long rc;
	struct nlmsghdr nlh = {
	.nlmsg_len = sizeof(nlh),
	.nlmsg_type = NLMSG_ERROR,
	};

	#ifdef NLM_F_CAPPED
	nlh.nlmsg_flags = NLM_F_REQUEST \| NLM_F_CAPPED,
	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {len=%u, type=NLMSG_ERROR"
	", flags=NLM_F_REQUEST\|NLM_F_CAPPED, seq=0, pid=0}"
	", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
	#endif

	#ifdef NLM_F_ACK_TLVS
	nlh.nlmsg_flags = NLM_F_REQUEST \| NLM_F_ACK_TLVS;
	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {len=%u, type=NLMSG_ERROR"
	", flags=NLM_F_REQUEST\|NLM_F_ACK_TLVS, seq=0, pid=0}"
	", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
	#endif

	#if defined NLM_F_CAPPED && defined NLM_F_ACK_TLVS
	nlh.nlmsg_flags = NLM_F_REQUEST \| NLM_F_CAPPED \| NLM_F_ACK_TLVS;
	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
	printf("sendto(%d, {len=%u, type=NLMSG_ERROR"
	", flags=NLM_F_REQUEST\|NLM_F_CAPPED\|NLM_F_ACK_TLVS, seq=0, pid=0}"
	", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
	fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
	#endif
	}
	#endif

	int main(void)
	{
	const int fd = create_nl_socket(NETLINK_SOCK_DIAG);

	char *path;
	if (asprintf(&path, "/proc/self/fd/%u", fd) < 0)
	perror_msg_and_fail("asprintf");
	char buf[256];
	if (getxattr(path, "system.sockprotoname", buf, sizeof(buf) - 1) < 0)
	perror_msg_and_skip("getxattr");
	free(path);

	send_query(fd);
	test_nlmsgerr(fd);
	test_nlmsg_done(fd);
	#if defined NLM_F_CAPPED \|\| defined NLM_F_ACK_TLVS
	test_ack_flags(fd);
	#endif

	puts("+++ exited with 0 +++");
	return 0;
	}

	#else

	SKIP_MAIN_UNDEFINED("HAVE_SYS_XATTR_H")

	#endif