On older kernels, when userspace program disables SIGSYS, catch ENOSYS and emulate getrandom(2) syscall with the kern.arandom sysctl (via existing arc4_sysctl wrapper). Special care is taken to faithfully emulate EFAULT on NULL pointers, because sysctl(3) as used by kern.arandom ignores NULL oldp. (This was caught by getentropy(3) ATF tests.) Reported by: kib Reviewed by: kib Discussed with: delphij Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D14785
88 lines
2.6 KiB
C
88 lines
2.6 KiB
C
/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2018 Conrad Meyer <cem@FreeBSD.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <errno.h>
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#include <signal.h>
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#include <unistd.h>
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#include <atf-c.h>
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ATF_TC_WITHOUT_HEAD(getentropy_count);
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ATF_TC_BODY(getentropy_count, tc)
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{
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char buf[2];
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int ret;
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/* getentropy(2) does not modify buf past the requested length */
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buf[1] = 0x7C;
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ret = getentropy(buf, 1);
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ATF_REQUIRE_EQ(ret, 0);
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ATF_REQUIRE_EQ(buf[1], 0x7C);
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}
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ATF_TC_WITHOUT_HEAD(getentropy_fault);
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ATF_TC_BODY(getentropy_fault, tc)
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{
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int ret;
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ret = getentropy(NULL, 1);
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ATF_REQUIRE_EQ(ret, -1);
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ATF_REQUIRE_EQ(errno, EFAULT);
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}
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ATF_TC_WITHOUT_HEAD(getentropy_sizes);
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ATF_TC_BODY(getentropy_sizes, tc)
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{
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char buf[512];
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ATF_REQUIRE_EQ(getentropy(buf, sizeof(buf)), -1);
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ATF_REQUIRE_EQ(errno, EIO);
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ATF_REQUIRE_EQ(getentropy(buf, 257), -1);
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ATF_REQUIRE_EQ(errno, EIO);
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/* Smaller sizes always succeed: */
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ATF_REQUIRE_EQ(getentropy(buf, 256), 0);
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ATF_REQUIRE_EQ(getentropy(buf, 128), 0);
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ATF_REQUIRE_EQ(getentropy(buf, 0), 0);
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}
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ATF_TP_ADD_TCS(tp)
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{
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signal(SIGSYS, SIG_IGN);
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ATF_TP_ADD_TC(tp, getentropy_count);
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ATF_TP_ADD_TC(tp, getentropy_fault);
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ATF_TP_ADD_TC(tp, getentropy_sizes);
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return (atf_no_error());
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}
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