strace/tests/netlink_protocol.c

/*
 * Check decoding of netlink protocol.
 *
 * Copyright (c) 2014-2017 Dmitry V. Levin <ldv@altlinux.org>
 * Copyright (c) 2016 Fabien Siron <fabien.siron@epita.fr>
 * 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;
	} *const reqs = tail_alloc(sizeof(*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 = tail_alloc(NLMSG_HDRLEN);
	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;
	void *const nlh0 = tail_alloc(NLMSG_HDRLEN);
	long rc;
	const int num = 0xfacefeed;

	/* 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