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      1 /*
      2  * Check decoding of netlink protocol.
      3  *
      4  * Copyright (c) 2014-2017 Dmitry V. Levin <ldv (at) altlinux.org>
      5  * Copyright (c) 2016 Fabien Siron <fabien.siron (at) epita.fr>
      6  * Copyright (c) 2016-2018 The strace developers.
      7  * All rights reserved.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. The name of the author may not be used to endorse or promote products
     18  *    derived from this software without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include "tests.h"
     33 
     34 #ifdef HAVE_SYS_XATTR_H
     35 
     36 # include <stdio.h>
     37 # include <stdlib.h>
     38 # include <string.h>
     39 # include <unistd.h>
     40 # include <sys/xattr.h>
     41 # include <netinet/in.h>
     42 # include "netlink.h"
     43 # include <linux/sock_diag.h>
     44 # include <linux/netlink_diag.h>
     45 
     46 static void
     47 send_query(const int fd)
     48 {
     49 	static const struct req {
     50 		struct nlmsghdr nlh;
     51 		const char magic[4];
     52 	} c_req = {
     53 		.nlh = {
     54 			.nlmsg_len = sizeof(struct req),
     55 			.nlmsg_type = NLMSG_NOOP,
     56 			.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST
     57 		},
     58 		.magic = "abcd"
     59 	};
     60 	struct req *const req = tail_memdup(&c_req, sizeof(c_req));
     61 	long rc;
     62 	const char *errstr;
     63 
     64 	/* zero address */
     65 	rc = sendto(fd, NULL, sizeof(*req), MSG_DONTWAIT, NULL, 0);
     66 	printf("sendto(%d, NULL, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
     67 	       fd, (unsigned) sizeof(*req), sprintrc(rc));
     68 
     69 	/* zero length */
     70 	rc = sendto(fd, req, 0, MSG_DONTWAIT, NULL, 0);
     71 	printf("sendto(%d, \"\", 0, MSG_DONTWAIT, NULL, 0) = %s\n",
     72 	       fd, sprintrc(rc));
     73 
     74 	/* zero address and length */
     75 	rc = sendto(fd, NULL, 0, MSG_DONTWAIT, NULL, 0);
     76 	printf("sendto(%d, NULL, 0, MSG_DONTWAIT, NULL, 0) = %s\n",
     77 	       fd, sprintrc(rc));
     78 
     79 	/* unfetchable struct nlmsghdr */
     80 	const void *const efault = tail_alloc(sizeof(struct nlmsghdr) - 1);
     81 	rc = sendto(fd, efault, sizeof(struct nlmsghdr), MSG_DONTWAIT, NULL, 0);
     82 	printf("sendto(%d, %p, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
     83 	       fd, efault, (unsigned) sizeof(struct nlmsghdr), sprintrc(rc));
     84 
     85 	/* whole message length < sizeof(struct nlmsghdr) */
     86 	rc = sendto(fd, req->magic, sizeof(req->magic), MSG_DONTWAIT, NULL, 0);
     87 	printf("sendto(%d, \"\\x61\\x62\\x63\\x64\""
     88 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
     89 	       fd, (unsigned) sizeof(req->magic), sprintrc(rc));
     90 
     91 	/* a single message with some data */
     92 	rc = sendto(fd, req, sizeof(*req), MSG_DONTWAIT, NULL, 0);
     93 	printf("sendto(%d, {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
     94 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
     95 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
     96 	       fd, req->nlh.nlmsg_len, NLM_F_DUMP,
     97 	       (unsigned) sizeof(*req), sprintrc(rc));
     98 
     99 	/* a single message without data */
    100 	req->nlh.nlmsg_len = sizeof(req->nlh);
    101 	rc = sendto(fd, &req->nlh, sizeof(req->nlh), MSG_DONTWAIT, NULL, 0);
    102 	printf("sendto(%d, {len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
    103 	       ", seq=0, pid=0}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    104 	       fd, req->nlh.nlmsg_len, NLM_F_DUMP,
    105 	       (unsigned) sizeof(req->nlh), sprintrc(rc));
    106 
    107 	/* nlmsg_len > whole message length */
    108 	req->nlh.nlmsg_len = sizeof(*req) + 8;
    109 	rc = sendto(fd, req, sizeof(*req), MSG_DONTWAIT, NULL, 0);
    110 	printf("sendto(%d, {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
    111 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
    112 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    113 	       fd, req->nlh.nlmsg_len, NLM_F_DUMP,
    114 	       (unsigned) sizeof(*req), sprintrc(rc));
    115 
    116 	/* nlmsg_len < sizeof(struct nlmsghdr) */
    117 	req->nlh.nlmsg_len = 8;
    118 	rc = sendto(fd, req, sizeof(*req), MSG_DONTWAIT, NULL, 0);
    119 	printf("sendto(%d, {len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
    120 	       ", seq=0, pid=0}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    121 	       fd, req->nlh.nlmsg_len, NLM_F_DUMP,
    122 	       (unsigned) sizeof(*req), sprintrc(rc));
    123 
    124 	/* a sequence of two nlmsg objects */
    125 	struct reqs {
    126 		struct req req1;
    127 		char padding[NLMSG_ALIGN(sizeof(struct req)) - sizeof(struct req)];
    128 		struct req req2;
    129 	};
    130 	TAIL_ALLOC_OBJECT_CONST_PTR(struct reqs, reqs);
    131 	memcpy(&reqs->req1, &c_req, sizeof(c_req));
    132 	memcpy(&reqs->req2, &c_req, sizeof(c_req));
    133 
    134 	rc = sendto(fd, reqs, sizeof(*reqs), MSG_DONTWAIT, NULL, 0);
    135 	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
    136 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
    137 	       ", {{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
    138 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}]"
    139 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    140 	       fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP,
    141 	       reqs->req2.nlh.nlmsg_len, NLM_F_DUMP,
    142 	       (unsigned) sizeof(*reqs), sprintrc(rc));
    143 
    144 	/* unfetchable second struct nlmsghdr */
    145 	void *const efault2 = tail_memdup(&reqs->req1, sizeof(reqs->req1));
    146 	rc = sendto(fd, efault2, sizeof(*reqs), MSG_DONTWAIT, NULL, 0);
    147 	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
    148 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
    149 	       ", ... /* %p */], %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    150 	       fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP,
    151 	       &((struct reqs *) efault2)->req2, (unsigned) sizeof(*reqs),
    152 	       sprintrc(rc));
    153 
    154 	/* message length is not enough for the second struct nlmsghdr */
    155 	rc = sendto(fd, reqs, sizeof(*reqs) - sizeof(req->nlh), MSG_DONTWAIT,
    156 		    NULL, 0);
    157 	errstr = sprintrc(rc);
    158 	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
    159 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}, ",
    160 	       fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP);
    161 	print_quoted_hex(&reqs->req2.nlh,
    162 			 sizeof(reqs->req2) - sizeof(req->nlh));
    163 	printf("], %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    164 	       (unsigned) (sizeof(*reqs) - sizeof(req->nlh)), errstr);
    165 
    166 	/* second nlmsg_len < sizeof(struct nlmsghdr) */
    167 	reqs->req2.nlh.nlmsg_len = 4;
    168 	rc = sendto(fd, reqs, sizeof(*reqs), MSG_DONTWAIT, NULL, 0);
    169 	printf("sendto(%d, [{{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
    170 	       ", seq=0, pid=0}, \"\\x61\\x62\\x63\\x64\"}"
    171 	       ", {len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
    172 	       ", seq=0, pid=0}], %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    173 	       fd, reqs->req1.nlh.nlmsg_len, NLM_F_DUMP,
    174 	       reqs->req2.nlh.nlmsg_len, NLM_F_DUMP,
    175 	       (unsigned) sizeof(*reqs), sprintrc(rc));
    176 
    177 	/* abbreviated output */
    178 # define ABBREV_LEN (DEFAULT_STRLEN + 1)
    179 	const unsigned int msg_len = sizeof(struct nlmsghdr) * ABBREV_LEN;
    180 	struct nlmsghdr *const msgs = tail_alloc(msg_len);
    181 	unsigned int i;
    182 	for (i = 0; i < ABBREV_LEN; ++i) {
    183 		msgs[i].nlmsg_len = sizeof(*msgs);
    184 		msgs[i].nlmsg_type = NLMSG_NOOP;
    185 		msgs[i].nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
    186 		msgs[i].nlmsg_seq = i;
    187 		msgs[i].nlmsg_pid = 0;
    188 	}
    189 
    190 	rc = sendto(fd, msgs, msg_len, MSG_DONTWAIT, NULL, 0);
    191 	errstr = sprintrc(rc);
    192 	printf("sendto(%d, [", fd);
    193 	for (i = 0; i < DEFAULT_STRLEN; ++i) {
    194 		if (i)
    195 			printf(", ");
    196 		printf("{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
    197 		       ", seq=%u, pid=0}",
    198 		       msgs[i].nlmsg_len, NLM_F_DUMP, msgs[i].nlmsg_seq);
    199 	}
    200 	printf(", ...], %u, MSG_DONTWAIT, NULL, 0) = %s\n", msg_len, errstr);
    201 }
    202 
    203 static void
    204 test_nlmsgerr(const int fd)
    205 {
    206 	struct nlmsgerr *err;
    207 	struct nlmsghdr *nlh;
    208 	void *const nlh0 = midtail_alloc(NLMSG_HDRLEN, sizeof(*err) + 4);
    209 	long rc;
    210 
    211 	/* error message without enough room for the error code */
    212 	nlh = nlh0;
    213 	nlh->nlmsg_len = NLMSG_HDRLEN + 4;
    214 	nlh->nlmsg_type = NLMSG_ERROR;
    215 	nlh->nlmsg_flags = NLM_F_REQUEST;
    216 	nlh->nlmsg_seq = 0;
    217 	nlh->nlmsg_pid = 0;
    218 
    219 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
    220 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
    221 	       ", seq=0, pid=0}, %p}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    222 	       fd, nlh->nlmsg_len, nlh0 + NLMSG_HDRLEN,
    223 	       nlh->nlmsg_len, sprintrc(rc));
    224 
    225 	nlh->nlmsg_len = NLMSG_HDRLEN + 2;
    226 	nlh = nlh0 - 2;
    227 	memmove(nlh, nlh0, sizeof(*nlh));
    228 	memcpy(NLMSG_DATA(nlh), "42", 2);
    229 
    230 	rc = sendto(fd, nlh, NLMSG_HDRLEN + 2, MSG_DONTWAIT, NULL, 0);
    231 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
    232 	       ", seq=0, pid=0}, \"\\x34\\x32\"}"
    233 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    234 	       fd, NLMSG_HDRLEN + 2, NLMSG_HDRLEN + 2, sprintrc(rc));
    235 
    236 	/* error message with room for the error code only */
    237 	nlh = nlh0 - sizeof(err->error);
    238 	nlh->nlmsg_len = NLMSG_HDRLEN + sizeof(err->error);
    239 	nlh->nlmsg_type = NLMSG_ERROR;
    240 	nlh->nlmsg_flags = NLM_F_REQUEST;
    241 	nlh->nlmsg_seq = 0;
    242 	nlh->nlmsg_pid = 0;
    243 	err = NLMSG_DATA(nlh);
    244 	err->error = 42;
    245 
    246 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
    247 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
    248 	       ", seq=0, pid=0}, {error=42}}, %u, MSG_DONTWAIT, NULL, 0)"
    249 	       " = %s\n", fd, nlh->nlmsg_len, nlh->nlmsg_len, sprintrc(rc));
    250 
    251 	err->error = -1;
    252 
    253 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
    254 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
    255 	       ", seq=0, pid=0}, {error=-EPERM}}, %u, MSG_DONTWAIT, NULL, 0)"
    256 	       " = %s\n", fd, nlh->nlmsg_len, nlh->nlmsg_len, sprintrc(rc));
    257 
    258 	err->error = -32767;
    259 	nlh->nlmsg_len += sizeof(err->msg.nlmsg_len);
    260 
    261 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
    262 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
    263 	       ", seq=0, pid=0}, {error=-32767, msg=%p}}"
    264 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    265 	       fd, nlh->nlmsg_len, nlh0 + NLMSG_HDRLEN,
    266 	       nlh->nlmsg_len, sprintrc(rc));
    267 
    268 	/* error message with room for the error code and a header */
    269 	nlh = nlh0 - sizeof(*err);
    270 	nlh->nlmsg_len = NLMSG_HDRLEN + sizeof(*err);
    271 	nlh->nlmsg_type = NLMSG_ERROR;
    272 	nlh->nlmsg_flags = NLM_F_REQUEST;
    273 	nlh->nlmsg_seq = 0;
    274 	nlh->nlmsg_pid = 0;
    275 	err = NLMSG_DATA(nlh);
    276 	err->error = -13;
    277 	err->msg.nlmsg_len = NLMSG_HDRLEN;
    278 	err->msg.nlmsg_type = NLMSG_NOOP;
    279 	err->msg.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
    280 	err->msg.nlmsg_seq = 42;
    281 	err->msg.nlmsg_pid = 1234;
    282 
    283 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
    284 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
    285 	       ", seq=0, pid=0}, {error=-EACCES"
    286 	       ", msg={len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
    287 	       ", seq=%u, pid=%u}}}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    288 	       fd, nlh->nlmsg_len, err->msg.nlmsg_len, NLM_F_DUMP,
    289 	       err->msg.nlmsg_seq, err->msg.nlmsg_pid,
    290 	       nlh->nlmsg_len, sprintrc(rc));
    291 
    292 	/* error message with room for the error code, a header, and some data */
    293 	nlh = nlh0 - sizeof(*err) - 4;
    294 	nlh->nlmsg_len = NLMSG_HDRLEN + sizeof(*err) + 4;
    295 	nlh->nlmsg_type = NLMSG_ERROR;
    296 	nlh->nlmsg_flags = NLM_F_REQUEST;
    297 	nlh->nlmsg_seq = 0;
    298 	nlh->nlmsg_pid = 0;
    299 	err = NLMSG_DATA(nlh);
    300 	err->error = -13;
    301 	err->msg.nlmsg_len = NLMSG_HDRLEN + 4;
    302 	err->msg.nlmsg_type = NLMSG_NOOP;
    303 	err->msg.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
    304 	err->msg.nlmsg_seq = 421;
    305 	err->msg.nlmsg_pid = 12345;
    306 	memcpy(NLMSG_DATA(&err->msg), "abcd", 4);
    307 
    308 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
    309 	printf("sendto(%d, {{len=%u, type=NLMSG_ERROR, flags=NLM_F_REQUEST"
    310 	       ", seq=0, pid=0}, {error=-EACCES"
    311 	       ", msg={{len=%u, type=NLMSG_NOOP, flags=NLM_F_REQUEST|0x%x"
    312 	       ", seq=%u, pid=%u}, \"\\x61\\x62\\x63\\x64\"}}}"
    313 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    314 	       fd, nlh->nlmsg_len, err->msg.nlmsg_len, NLM_F_DUMP,
    315 	       err->msg.nlmsg_seq, err->msg.nlmsg_pid,
    316 	       nlh->nlmsg_len, sprintrc(rc));
    317 }
    318 
    319 static void
    320 test_nlmsg_done(const int fd)
    321 {
    322 	struct nlmsghdr *nlh;
    323 	const int num = 0xfacefeed;
    324 	void *const nlh0 = midtail_alloc(NLMSG_HDRLEN, sizeof(num));
    325 	long rc;
    326 
    327 	/* NLMSG_DONE message without enough room for an integer payload */
    328 	nlh = nlh0;
    329 	*nlh = (struct nlmsghdr) {
    330 		.nlmsg_len = NLMSG_HDRLEN + sizeof(num),
    331 		.nlmsg_type = NLMSG_DONE,
    332 		.nlmsg_flags = NLM_F_MULTI
    333 	};
    334 
    335 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
    336 	printf("sendto(%d, {{len=%u, type=NLMSG_DONE, flags=NLM_F_MULTI"
    337 	       ", seq=0, pid=0}, %p}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    338 	       fd, nlh->nlmsg_len, nlh0 + NLMSG_HDRLEN,
    339 	       nlh->nlmsg_len, sprintrc(rc));
    340 
    341 	/* NLMSG_DONE message with enough room for an oddly short payload */
    342 	nlh->nlmsg_len = NLMSG_HDRLEN + 2;
    343 	nlh = nlh0 - 2;
    344 	/* Beware of unaligned access to nlh members. */
    345 	memmove(nlh, nlh0, sizeof(*nlh));
    346 	memcpy(NLMSG_DATA(nlh), "42", 2);
    347 
    348 	rc = sendto(fd, nlh, NLMSG_HDRLEN + 2, MSG_DONTWAIT, NULL, 0);
    349 	printf("sendto(%d, {{len=%u, type=NLMSG_DONE, flags=NLM_F_MULTI, seq=0"
    350 	       ", pid=0}, \"\\x34\\x32\"}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    351 	       fd, NLMSG_HDRLEN + 2, NLMSG_HDRLEN + 2, sprintrc(rc));
    352 
    353 	/* NLMSG_DONE message with enough room for an integer payload */
    354 	nlh = nlh0 - sizeof(num);
    355 	*nlh = (struct nlmsghdr) {
    356 		.nlmsg_len = NLMSG_HDRLEN + sizeof(num),
    357 		.nlmsg_type = NLMSG_DONE,
    358 		.nlmsg_flags = NLM_F_MULTI
    359 	};
    360 	memcpy(NLMSG_DATA(nlh), &num, sizeof(num));
    361 
    362 	rc = sendto(fd, nlh, nlh->nlmsg_len, MSG_DONTWAIT, NULL, 0);
    363 	printf("sendto(%d, {{len=%u, type=NLMSG_DONE, flags=NLM_F_MULTI"
    364 	       ", seq=0, pid=0}, %d}, %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    365 	       fd, nlh->nlmsg_len, num, nlh->nlmsg_len, sprintrc(rc));
    366 }
    367 
    368 #if defined NLM_F_CAPPED || defined NLM_F_ACK_TLVS
    369 static void
    370 test_ack_flags(const int fd)
    371 {
    372 	long rc;
    373 	struct nlmsghdr nlh = {
    374 		.nlmsg_len = sizeof(nlh),
    375 		.nlmsg_type = NLMSG_ERROR,
    376 	};
    377 
    378 #ifdef NLM_F_CAPPED
    379 	nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CAPPED,
    380 	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
    381 	printf("sendto(%d, {len=%u, type=NLMSG_ERROR"
    382 	       ", flags=NLM_F_REQUEST|NLM_F_CAPPED, seq=0, pid=0}"
    383 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    384 	       fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
    385 #endif
    386 
    387 #ifdef NLM_F_ACK_TLVS
    388 	nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK_TLVS;
    389 	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
    390 	printf("sendto(%d, {len=%u, type=NLMSG_ERROR"
    391 	       ", flags=NLM_F_REQUEST|NLM_F_ACK_TLVS, seq=0, pid=0}"
    392 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    393 	       fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
    394 #endif
    395 
    396 #if defined NLM_F_CAPPED && defined NLM_F_ACK_TLVS
    397 	nlh.nlmsg_flags = NLM_F_REQUEST | NLM_F_CAPPED | NLM_F_ACK_TLVS;
    398 	rc = sendto(fd, &nlh, sizeof(nlh), MSG_DONTWAIT, NULL, 0);
    399 	printf("sendto(%d, {len=%u, type=NLMSG_ERROR"
    400 	       ", flags=NLM_F_REQUEST|NLM_F_CAPPED|NLM_F_ACK_TLVS, seq=0, pid=0}"
    401 	       ", %u, MSG_DONTWAIT, NULL, 0) = %s\n",
    402 	       fd, nlh.nlmsg_len, (unsigned) sizeof(nlh), sprintrc(rc));
    403 #endif
    404 }
    405 #endif
    406 
    407 int main(void)
    408 {
    409 	const int fd = create_nl_socket(NETLINK_SOCK_DIAG);
    410 
    411 	char *path;
    412 	if (asprintf(&path, "/proc/self/fd/%u", fd) < 0)
    413 		perror_msg_and_fail("asprintf");
    414 	char buf[256];
    415 	if (getxattr(path, "system.sockprotoname", buf, sizeof(buf) - 1) < 0)
    416 		perror_msg_and_skip("getxattr");
    417 	free(path);
    418 
    419 	send_query(fd);
    420 	test_nlmsgerr(fd);
    421 	test_nlmsg_done(fd);
    422 #if defined NLM_F_CAPPED || defined NLM_F_ACK_TLVS
    423 	test_ack_flags(fd);
    424 #endif
    425 
    426 	puts("+++ exited with 0 +++");
    427 	return 0;
    428 }
    429 
    430 #else
    431 
    432 SKIP_MAIN_UNDEFINED("HAVE_SYS_XATTR_H")
    433 
    434 #endif
    435