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      1 /*-
      2  * Copyright (c) 2013 The NetBSD Foundation, Inc.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  *
     14  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     15  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     16  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     18  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     19  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     20  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     21  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     22  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     23  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     24  * POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 
     27 #include <sys/cdefs.h>
     28 __COPYRIGHT("@(#) Copyright (c) 2013\
     29  The NetBSD Foundation, inc. All rights reserved.");
     30 __RCSID("$NetBSD: t_kauth_pr_47598.c,v 1.6 2022/01/26 11:48:54 andvar Exp $");
     31 
     32 #include <errno.h>
     33 #include <unistd.h>
     34 #include <stdio.h>
     35 #include <stdlib.h>
     36 #include <sys/sysctl.h>
     37 #include <sys/socket.h>
     38 #include <netinet/in.h>
     39 #include <arpa/inet.h>
     40 #include <atf-c.h>
     41 
     42 /*
     43  * helper function
     44  */
     45 static const char curtain_name[] = "security.models.bsd44.curtain";
     46 static const char securelevel_name[] = "security.models.bsd44.securelevel";
     47 
     48 static bool may_lower_curtain(void);
     49 static int get_curtain(void);
     50 static void set_curtain(int newval);
     51 
     52 static bool
     53 may_lower_curtain(void)
     54 {
     55 	int seclevel;
     56 	size_t len = sizeof(seclevel);
     57 
     58 	if (sysctlbyname(securelevel_name, &seclevel, &len, NULL, 0) != 0)
     59 		atf_tc_fail("failed to read %s", securelevel_name);
     60 
     61 	return seclevel <= 0;
     62 }
     63 
     64 static int
     65 get_curtain(void)
     66 {
     67 	int curtain;
     68 	size_t len = sizeof(curtain);
     69 
     70 	if (sysctlbyname(curtain_name, &curtain, &len, NULL, 0) != 0)
     71 		atf_tc_fail("failed to read %s", curtain_name);
     72 
     73 	return curtain;
     74 }
     75 
     76 static void
     77 set_curtain(int newval)
     78 {
     79 
     80 	if (sysctlbyname(curtain_name, NULL, 0, &newval, sizeof(newval)) != 0)
     81 		atf_tc_fail("failed to set %s to %d", curtain_name, newval);
     82 }
     83 
     84 /*
     85  * PR kern/47598: if security.models.extensions.curtain = 1 we crash when
     86  * doing a netstat while an embryonic (not yet fully accepted) connection
     87  * exists.
     88  * This has been fixed with rev. 1.5 of
     89  *   src/sys/secmodel/extensions/secmodel_extensions.c.
     90  */
     91 
     92 
     93 ATF_TC(kauth_curtain);
     94 ATF_TC_HEAD(kauth_curtain, tc)
     95 {
     96 	atf_tc_set_md_var(tc, "require.user", "root");
     97 	atf_tc_set_md_var(tc, "require.progs", "netstat");
     98 	atf_tc_set_md_var(tc, "descr",
     99 	    "Checks for kernel crash with curtain active (PR kern/47598)");
    100 }
    101 
    102 ATF_TC_BODY(kauth_curtain, tc)
    103 {
    104 
    105 	int old_curtain, s, s2, err;
    106 	socklen_t slen;
    107 	struct sockaddr_in sa;
    108 
    109 	/*
    110 	 * save old value of "curtain" and enable it
    111 	 */
    112 	old_curtain = get_curtain();
    113 	if (old_curtain < 1 && !may_lower_curtain())
    114 		atf_tc_skip("curtain is not enabled and we would not be able"
    115 		    " to drop it later due to securelevel settings");
    116 
    117 	set_curtain(1);
    118 
    119 	/*
    120 	 * create a socket and bind it to some arbitrary free port
    121 	 */
    122 	s = socket(PF_INET, SOCK_STREAM|SOCK_NONBLOCK, 0);
    123 	ATF_REQUIRE_MSG(s != -1, "socket: %d", errno);
    124 	memset(&sa, 0, sizeof(sa));
    125 	sa.sin_family = AF_INET;
    126 	sa.sin_len = sizeof(sa);
    127 	sa.sin_addr.s_addr = inet_addr("127.0.0.1");
    128 	ATF_REQUIRE_MSG(bind(s, (struct sockaddr *)&sa, sizeof(sa)) == 0,
    129 	    "bind: %d", errno);
    130 	ATF_REQUIRE_MSG(listen(s, 16) == 0, "listen: %d", errno);
    131 
    132 	/*
    133 	 * extract address and open a connection to the port
    134 	 */
    135 	slen = sizeof(sa);
    136 	ATF_REQUIRE_MSG(getsockname(s, (struct sockaddr *)&sa, &slen) == 0,
    137 	    "getsockname: %d", errno);
    138 	s2 = socket(PF_INET, SOCK_STREAM|SOCK_NONBLOCK, 0);
    139 	ATF_REQUIRE_MSG(s2 != -1, "socket: %d", errno);
    140 	printf("port is %d\n", ntohs(sa.sin_port));
    141 	err = connect(s2, (struct sockaddr *)&sa, sizeof(sa));
    142 	ATF_REQUIRE_MSG(err == -1 && errno == EINPROGRESS,
    143 	    "connect returned %d with errno %d", err, errno);
    144 	fflush(stdout);
    145 	fflush(stderr);
    146 
    147 	/*
    148 	 * we now have a pending, not yet accepted connection - run netstat
    149 	 */
    150 	system("netstat -aA");
    151 
    152 	/*
    153 	 * cleanup
    154 	 */
    155 	close(s2);
    156 	close(s);
    157 
    158 	/*
    159 	 * restore old value of curtain
    160 	 */
    161 	set_curtain(old_curtain);
    162 }
    163 
    164 ATF_TP_ADD_TCS(tp)
    165 {
    166 	ATF_TP_ADD_TC(tp, kauth_curtain);
    167 
    168 	return atf_no_error();
    169 }
    170 
    171 
    172