Date: Wed, 21 Mar 2018 01:15:45 +0000 (UTC) From: Conrad Meyer <cem@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r331279 - in head: include lib/libc/gen lib/libc/sys lib/libc/tests/gen sys/compat/freebsd32 sys/conf sys/kern sys/sys tests/sys/kern usr.bin/truss Message-ID: <201803210115.w2L1Fjt9084698@repo.freebsd.org>
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Author: cem Date: Wed Mar 21 01:15:45 2018 New Revision: 331279 URL: https://svnweb.freebsd.org/changeset/base/331279 Log: Implement getrandom(2) and getentropy(3) The general idea here is to provide userspace programs with well-defined sources of entropy, in a fashion that doesn't require opening a new file descriptor (ulimits) or accessing paths (/dev/urandom may be restricted by chroot or capsicum). getrandom(2) is the more general API, and comes from the Linux world. Since our urandom and random devices are identical, the GRND_RANDOM flag is ignored. getentropy(3) is added as a compatibility shim for the OpenBSD API. truss(1) support is included. Tests for both system calls are provided. Coverage is believed to be at least as comprehensive as LTP getrandom(2) test coverage. Additionally, instructions for running the LTP tests directly against FreeBSD are provided in the "Test Plan" section of the Differential revision linked below. (They pass, of course.) PR: 194204 Reported by: David CARLIER <david.carlier AT hardenedbsd.org> Discussed with: cperciva, delphij, jhb, markj Relnotes: maybe Differential Revision: https://reviews.freebsd.org/D14500 Added: head/lib/libc/gen/getentropy.3 (contents, props changed) head/lib/libc/gen/getentropy.c (contents, props changed) head/lib/libc/sys/getrandom.2 (contents, props changed) head/lib/libc/tests/gen/getentropy_test.c (contents, props changed) head/sys/kern/sys_getrandom.c (contents, props changed) head/tests/sys/kern/sys_getrandom.c (contents, props changed) Modified: head/include/unistd.h head/lib/libc/gen/Makefile.inc head/lib/libc/gen/Symbol.map head/lib/libc/sys/Makefile.inc head/lib/libc/sys/Symbol.map head/lib/libc/tests/gen/Makefile head/sys/compat/freebsd32/syscalls.master head/sys/conf/files head/sys/kern/syscalls.master head/sys/sys/random.h head/tests/sys/kern/Makefile head/usr.bin/truss/syscalls.c Modified: head/include/unistd.h ============================================================================== --- head/include/unistd.h Tue Mar 20 23:08:42 2018 (r331278) +++ head/include/unistd.h Wed Mar 21 01:15:45 2018 (r331279) @@ -506,6 +506,7 @@ int execvP(const char *, const char *, char * const * int feature_present(const char *); char *fflagstostr(u_long); int getdomainname(char *, int); +int getentropy(void *, size_t); int getgrouplist(const char *, gid_t, gid_t *, int *); int getloginclass(char *, size_t); mode_t getmode(const void *, mode_t); Modified: head/lib/libc/gen/Makefile.inc ============================================================================== --- head/lib/libc/gen/Makefile.inc Tue Mar 20 23:08:42 2018 (r331278) +++ head/lib/libc/gen/Makefile.inc Wed Mar 21 01:15:45 2018 (r331279) @@ -57,6 +57,7 @@ SRCS+= __getosreldate.c \ getcap.c \ getcwd.c \ getdomainname.c \ + getentropy.c \ getgrent.c \ getgrouplist.c \ gethostname.c \ @@ -220,6 +221,7 @@ MAN+= alarm.3 \ getcwd.3 \ getdiskbyname.3 \ getdomainname.3 \ + getentropy.3 \ getfsent.3 \ getgrent.3 \ getgrouplist.3 \ Modified: head/lib/libc/gen/Symbol.map ============================================================================== --- head/lib/libc/gen/Symbol.map Tue Mar 20 23:08:42 2018 (r331278) +++ head/lib/libc/gen/Symbol.map Wed Mar 21 01:15:45 2018 (r331279) @@ -408,6 +408,7 @@ FBSD_1.5 { fts_set; fts_set_clientptr; ftw; + getentropy; getmntinfo; glob; globfree; Added: head/lib/libc/gen/getentropy.3 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/lib/libc/gen/getentropy.3 Wed Mar 21 01:15:45 2018 (r331279) @@ -0,0 +1,86 @@ +.\" $OpenBSD: getentropy.2,v 1.8 2015/01/31 00:20:12 schwarze Exp $ +.\" +.\" Copyright (c) 2018 Conrad Meyer <cem@FreeBSD.org> +.\" Copyright (c) 2014 Theo de Raadt +.\" +.\" Permission to use, copy, modify, and distribute this software for any +.\" purpose with or without fee is hereby granted, provided that the above +.\" copyright notice and this permission notice appear in all copies. +.\" +.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +.\" +.\" $FreeBSD$ +.\" +.Dd February 24, 2018 +.Dt GETENTROPY 3 +.Os +.Sh NAME +.Nm getentropy +.Nd get entropy +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In unistd.h +.Ft int +.Fn getentropy "void *buf" "size_t buflen" +.Sh DESCRIPTION +.Fn getentropy +fills a buffer with high-quality random data. +.Pp +The maximum +.Fa buflen +permitted is 256 bytes. +.Pp +If it does not produce an error, +.Fn getentropy +always provides the requested number of bytes of random data. +.Pp +Similar to reading from +.Pa /dev/urandom +just after boot, +.Fn getentropy +may block until the system has collected enough entropy to seed the CSPRNG. +.Sh IMPLEMENTATION NOTES +The +.Fn getentropy +function is implemented using +.Xr getrandom 2 . +.Sh RETURN VALUES +.Rv -std +.Sh ERRORS +.Fn getentropy +will succeed unless: +.Bl -tag -width Er +.It Bq Er EFAULT +The +.Fa buf +parameter points to an +invalid address. +.It Bq Er EIO +Too many bytes requested, or some other fatal error occurred. +.El +.Sh SEE ALSO +.Xr arc4random 3 , +.Xr getrandom 2 , +.Xr random 4 +.Sh STANDARDS +.Fn getentropy +is non-standard. +It is present on +.Ox +and Linux. +.Sh HISTORY +The +.Fn getentropy +function appeared in +.Ox 5.6 . +The +.Fx +libc compatibility shim first appeared in +.Fx 12.0 . Added: head/lib/libc/gen/getentropy.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/lib/libc/gen/getentropy.c Wed Mar 21 01:15:45 2018 (r331279) @@ -0,0 +1,70 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD + * + * Copyright (c) 2018 Conrad Meyer <cem@FreeBSD.org> + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/random.h> + +#include <errno.h> +#include <stdlib.h> + +#include "libc_private.h" + +int +getentropy(void *buf, size_t buflen) +{ + ssize_t rd; + + if (buflen > 256) { + errno = EIO; + return (-1); + } + + while (buflen > 0) { + rd = getrandom(buf, buflen, 0); + if (rd == -1) { + if (errno == EINTR) + continue; + else if (errno == ENOSYS) + abort(); + else + return (-1); + } + + /* This cannot happen. */ + if (rd == 0) + abort(); + + buf = (char *)buf + rd; + buflen -= rd; + } + + return (0); +} Modified: head/lib/libc/sys/Makefile.inc ============================================================================== --- head/lib/libc/sys/Makefile.inc Tue Mar 20 23:08:42 2018 (r331278) +++ head/lib/libc/sys/Makefile.inc Wed Mar 21 01:15:45 2018 (r331279) @@ -197,6 +197,7 @@ MAN+= abort2.2 \ getpgrp.2 \ getpid.2 \ getpriority.2 \ + getrandom.2 \ getrlimit.2 \ getrusage.2 \ getsid.2 \ Modified: head/lib/libc/sys/Symbol.map ============================================================================== --- head/lib/libc/sys/Symbol.map Tue Mar 20 23:08:42 2018 (r331278) +++ head/lib/libc/sys/Symbol.map Wed Mar 21 01:15:45 2018 (r331279) @@ -392,6 +392,7 @@ FBSD_1.5 { getdents; getdirentries; getfsstat; + getrandom; kevent; lstat; mknod; @@ -627,6 +628,8 @@ FBSDprivate_1.0 { __sys_getppid; _getpriority; __sys_getpriority; + _getrandom; + __sys_getrandom; _getresgid; __sys_getresgid; _getresuid; Added: head/lib/libc/sys/getrandom.2 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/lib/libc/sys/getrandom.2 Wed Mar 21 01:15:45 2018 (r331279) @@ -0,0 +1,121 @@ +.\" Copyright (c) 2018 Conrad Meyer <cem@FreeBSD.org> +.\" 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. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``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 AUTHORS OR CONTRIBUTORS 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. +.\" +.\" $FreeBSD$ +.\" +.Dd February 24, 2018 +.Dt GETRANDOM 2 +.Os +.Sh NAME +.Nm getrandom +.Nd get random data +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In sys/random.h +.Ft ssize_t +.Fn getrandom "void *buf" "size_t buflen" "unsigned int flags" +.Sh DESCRIPTION +.Fn getrandom +fills +.Fa buf +with up to +.Fa buflen +bytes of random data. +.Pp +The +.Fa flags +argument may include zero or more of the following: +.Bl -tag -width _GRND_NONBLOCK_ +.It Ql GRND_NONBLOCK +Return +.Er EAGAIN +instead of blocking, if the +.Xr random 4 +device has not yet been seeded. +By default, +.Fn getrandom +will block until the device is seeded. +.It Ql GRND_RANDOM +This flag does nothing on +.Fx . +.Pa /dev/random +and +.Pa /dev/urandom +are identical. +.El +.Pp +If the +.Xr random 4 +device has been seeded, reads of up to 256 bytes will always return as many +bytes as requested and will not be interrupted by signals. +.Pp +.Sh RETURN VALUES +Upon successful completion, the number of bytes which were actually read is +returned. +For requests larger than 256 bytes, this can be fewer bytes than were +requested. +Otherwise, -1 is returned and the global variable +.Va errno +is set to indicate the error. +.Sh ERRORS +The +.Fn getrandom +operation returns the following errors: +.Bl -tag -width Er +.It Bq Er EAGAIN +The +.Ql GRND_NONBLOCK +flag was set and the +.Xr random 4 +device was not yet seeded. +.It Bq Er EFAULT +The +.Fa buf +parameter points to an invalid address. +.It Bq Er EINTR +The sleep was interrupted by a signal. +.It Bq Er EINVAL +An invalid +.Fa flags +was specified. +.It Bq Er EINVAL +The requested +.Fa buflen +was larger than +.Dv IOSIZE_MAX . +.El +.Sh SEE ALSO +.Xr arc4random 3 , +.Xr getentropy 3 , +.Xr random 4 +.Sh STANDARDS +.Fn getentropy +is non-standard. +It is present in Linux. +.Sh HISTORY +The +.Fn getrandom +system call first appeared in +.Fx 12.0 . Modified: head/lib/libc/tests/gen/Makefile ============================================================================== --- head/lib/libc/tests/gen/Makefile Tue Mar 20 23:08:42 2018 (r331278) +++ head/lib/libc/tests/gen/Makefile Wed Mar 21 01:15:45 2018 (r331279) @@ -10,6 +10,7 @@ ATF_TESTS_C+= fmtmsg_test ATF_TESTS_C+= fnmatch2_test ATF_TESTS_C+= fpclassify2_test ATF_TESTS_C+= ftw_test +ATF_TESTS_C+= getentropy_test ATF_TESTS_C+= getmntinfo_test ATF_TESTS_C+= glob2_test ATF_TESTS_C+= makecontext_test @@ -61,6 +62,8 @@ NETBSD_ATF_TESTS_C+= vis_test .include "../Makefile.netbsd-tests" +CFLAGS.getentropy_test+= -I${SRCTOP}/include +LIBADD.getentropy_test+= c LIBADD.humanize_number_test+= util LIBADD.fpclassify_test+=m Added: head/lib/libc/tests/gen/getentropy_test.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/lib/libc/tests/gen/getentropy_test.c Wed Mar 21 01:15:45 2018 (r331279) @@ -0,0 +1,84 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD + * + * Copyright (c) 2018 Conrad Meyer <cem@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <errno.h> +#include <unistd.h> + +#include <atf-c.h> + +ATF_TC_WITHOUT_HEAD(getentropy_count); +ATF_TC_BODY(getentropy_count, tc) +{ + char buf[2]; + int ret; + + /* getentropy(2) does not modify buf past the requested length */ + buf[1] = 0x7C; + ret = getentropy(buf, 1); + ATF_REQUIRE_EQ(ret, 0); + ATF_REQUIRE_EQ(buf[1], 0x7C); +} + +ATF_TC_WITHOUT_HEAD(getentropy_fault); +ATF_TC_BODY(getentropy_fault, tc) +{ + int ret; + + ret = getentropy(NULL, 1); + ATF_REQUIRE_EQ(ret, -1); + ATF_REQUIRE_EQ(errno, EFAULT); +} + +ATF_TC_WITHOUT_HEAD(getentropy_sizes); +ATF_TC_BODY(getentropy_sizes, tc) +{ + char buf[512]; + + ATF_REQUIRE_EQ(getentropy(buf, sizeof(buf)), -1); + ATF_REQUIRE_EQ(errno, EIO); + ATF_REQUIRE_EQ(getentropy(buf, 257), -1); + ATF_REQUIRE_EQ(errno, EIO); + + /* Smaller sizes always succeed: */ + ATF_REQUIRE_EQ(getentropy(buf, 256), 0); + ATF_REQUIRE_EQ(getentropy(buf, 128), 0); + ATF_REQUIRE_EQ(getentropy(buf, 0), 0); +} + +ATF_TP_ADD_TCS(tp) +{ + + ATF_TP_ADD_TC(tp, getentropy_count); + ATF_TP_ADD_TC(tp, getentropy_fault); + ATF_TP_ADD_TC(tp, getentropy_sizes); + return (atf_no_error()); +} Modified: head/sys/compat/freebsd32/syscalls.master ============================================================================== --- head/sys/compat/freebsd32/syscalls.master Tue Mar 20 23:08:42 2018 (r331278) +++ head/sys/compat/freebsd32/syscalls.master Wed Mar 21 01:15:45 2018 (r331279) @@ -1116,5 +1116,7 @@ cpuwhich_t which, uint32_t id1, uint32_t id2, \ size_t domainsetsize, domainset_t *mask, \ int policy); } +563 AUE_NULL NOPROTO { int getrandom(void *buf, size_t buflen, \ + unsigned int flags); } ; vim: syntax=off Modified: head/sys/conf/files ============================================================================== --- head/sys/conf/files Tue Mar 20 23:08:42 2018 (r331278) +++ head/sys/conf/files Wed Mar 21 01:15:45 2018 (r331279) @@ -3895,6 +3895,7 @@ kern/subr_vmem.c standard kern/subr_witness.c optional witness kern/sys_capability.c standard kern/sys_generic.c standard +kern/sys_getrandom.c standard kern/sys_pipe.c standard kern/sys_procdesc.c standard kern/sys_process.c standard Added: head/sys/kern/sys_getrandom.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/sys/kern/sys_getrandom.c Wed Mar 21 01:15:45 2018 (r331279) @@ -0,0 +1,97 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD + * + * Copyright (c) 2018 Conrad Meyer <cem@FreeBSD.org> + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "opt_compat.h" + +#include <sys/param.h> +#include <sys/errno.h> +#include <sys/proc.h> +#include <sys/random.h> +#include <sys/sysproto.h> +#include <sys/systm.h> +#include <sys/uio.h> + +#define GRND_VALIDFLAGS (GRND_NONBLOCK | GRND_RANDOM) + +/* + * random_read_uio(9) returns EWOULDBLOCK if a nonblocking request would block, + * but the Linux API name is EAGAIN. On FreeBSD, they have the same numeric + * value for now. + */ +CTASSERT(EWOULDBLOCK == EAGAIN); + +static int +kern_getrandom(struct thread *td, void *user_buf, size_t buflen, + unsigned int flags) +{ + struct uio auio; + struct iovec aiov; + int error; + + if ((flags & ~GRND_VALIDFLAGS) != 0) + return (EINVAL); + if (buflen > IOSIZE_MAX) + return (EINVAL); + + if (buflen == 0) { + td->td_retval[0] = 0; + return (0); + } + + aiov.iov_base = user_buf; + aiov.iov_len = buflen; + auio.uio_iov = &aiov; + auio.uio_iovcnt = 1; + auio.uio_offset = 0; + auio.uio_resid = buflen; + auio.uio_segflg = UIO_USERSPACE; + auio.uio_rw = UIO_READ; + auio.uio_td = td; + + error = read_random_uio(&auio, (flags & GRND_NONBLOCK) != 0); + if (error == 0) + td->td_retval[0] = buflen - auio.uio_resid; + return (error); +} + +#ifndef _SYS_SYSPROTO_H_ +struct getrandom_args { + void *buf; + size_t buflen; + unsigned int flags; +}; +#endif + +int +sys_getrandom(struct thread *td, struct getrandom_args *uap) +{ + return (kern_getrandom(td, uap->buf, uap->buflen, uap->flags)); +} Modified: head/sys/kern/syscalls.master ============================================================================== --- head/sys/kern/syscalls.master Tue Mar 20 23:08:42 2018 (r331278) +++ head/sys/kern/syscalls.master Wed Mar 21 01:15:45 2018 (r331279) @@ -1021,6 +1021,8 @@ cpuwhich_t which, id_t id, \ size_t domainsetsize, domainset_t *mask, \ int policy); } +563 AUE_NULL STD { int getrandom(void *buf, size_t buflen, \ + unsigned int flags); } ; Please copy any additions and changes to the following compatability tables: ; sys/compat/freebsd32/syscalls.master Modified: head/sys/sys/random.h ============================================================================== --- head/sys/sys/random.h Tue Mar 20 23:08:42 2018 (r331278) +++ head/sys/sys/random.h Wed Mar 21 01:15:45 2018 (r331279) @@ -31,10 +31,10 @@ #ifndef _SYS_RANDOM_H_ #define _SYS_RANDOM_H_ -#ifdef _KERNEL - #include <sys/types.h> +#ifdef _KERNEL + #if !defined(KLD_MODULE) #if defined(RANDOM_LOADABLE) && defined(RANDOM_YARROW) #error "Cannot define both RANDOM_LOADABLE and RANDOM_YARROW" @@ -126,5 +126,9 @@ void random_harvest_deregister_source(enum random_entr #endif /* defined(RANDOM_ENABLE_UMA) */ #endif /* _KERNEL */ + +#define GRND_NONBLOCK 0x1 +#define GRND_RANDOM 0x2 +ssize_t getrandom(void *buf, size_t buflen, unsigned int flags); #endif /* _SYS_RANDOM_H_ */ Modified: head/tests/sys/kern/Makefile ============================================================================== --- head/tests/sys/kern/Makefile Tue Mar 20 23:08:42 2018 (r331278) +++ head/tests/sys/kern/Makefile Wed Mar 21 01:15:45 2018 (r331279) @@ -11,6 +11,7 @@ ATF_TESTS_C+= ptrace_test TEST_METADATA.ptrace_test+= timeout="15" ATF_TESTS_C+= reaper PLAIN_TESTS_C+= subr_unit_test +ATF_TESTS_C+= sys_getrandom ATF_TESTS_C+= unix_seqpacket_test ATF_TESTS_C+= unix_passfd_test TEST_METADATA.unix_seqpacket_test+= timeout="15" @@ -21,6 +22,10 @@ ATF_TESTS_SH+= coredump_phnum_test BINDIR= ${TESTSDIR} PROGS+= coredump_phnum_helper +CFLAGS.sys_getrandom+= -I${SRCTOP}/sys/contrib/zstd/lib +LIBADD.sys_getrandom+= zstd +LIBADD.sys_getrandom+= c +LIBADD.sys_getrandom+= pthread LIBADD.ptrace_test+= pthread LIBADD.unix_seqpacket_test+= pthread Added: head/tests/sys/kern/sys_getrandom.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/tests/sys/kern/sys_getrandom.c Wed Mar 21 01:15:45 2018 (r331279) @@ -0,0 +1,130 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause-FreeBSD + * + * Copyright (c) 2018 Conrad Meyer <cem@FreeBSD.org> + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/random.h> +#include <errno.h> + +#include <atf-c.h> + +#include <zstd.h> + +const static unsigned valid_flags[] = { 0, GRND_NONBLOCK, GRND_RANDOM, + GRND_NONBLOCK | GRND_RANDOM }; + +ATF_TC_WITHOUT_HEAD(getrandom_randomness); +ATF_TC_BODY(getrandom_randomness, tc) +{ + char randomb[4096], compressed[5000]; + ssize_t ret; + size_t i, j, c; + unsigned mode; + + for (i = 0; i < nitems(valid_flags); i++) { + mode = valid_flags[i]; + + /* Get new random data, filling randomb. */ + + memset(randomb, 0, sizeof(randomb)); + + for (j = 0; j < sizeof(randomb);) { + ret = getrandom(&randomb[j], sizeof(randomb) - j, mode); + if (ret < 0 && (mode & GRND_NONBLOCK) != 0 && + errno == EAGAIN) + continue; + + ATF_REQUIRE_MSG(ret >= 0, "other error: %d", errno); + ATF_REQUIRE_MSG(ret > 0, "bogus zero return"); + + j += (size_t)ret; + } + + /* Perform compressibility test */ + c = ZSTD_compress(compressed, sizeof(compressed), randomb, + sizeof(randomb), ZSTD_maxCLevel()); + ATF_REQUIRE_MSG(!ZSTD_isError(c), "zstd compress: %s", + ZSTD_getErrorName(c)); + + /* + * If the output is very compressible, it's probably not random + */ + ATF_REQUIRE_MSG(c > (sizeof(randomb) * 4 / 5), + "purportedly random data was compressible: %zu/%zu or %f%%", + c, sizeof(randomb), (double)c / (double)sizeof(randomb)); + } +} + +ATF_TC_WITHOUT_HEAD(getrandom_fault); +ATF_TC_BODY(getrandom_fault, tc) +{ + ssize_t ret; + + ret = getrandom(NULL, 1, 0); + ATF_REQUIRE_EQ(ret, -1); + ATF_REQUIRE_EQ(errno, EFAULT); +} + +ATF_TC_WITHOUT_HEAD(getrandom_count); +ATF_TC_BODY(getrandom_count, tc) +{ + char buf[4096], reference[4096]; + ssize_t ret; + + /* getrandom(2) does not modify buf past the requested length */ + _Static_assert(sizeof(reference) == sizeof(buf), "must match"); + memset(reference, 0x7C, sizeof(reference)); + + memset(buf, 0x7C, sizeof(buf)); + ret = getrandom(buf, 1, 0); + ATF_REQUIRE_EQ(ret, 1); + ATF_REQUIRE_EQ(memcmp(&buf[1], reference, sizeof(reference) - 1), 0); + + memset(buf, 0x7C, sizeof(buf)); + ATF_REQUIRE_EQ(getrandom(buf, 15, 0), 15); + ATF_REQUIRE_EQ(memcmp(&buf[15], reference, sizeof(reference) - 15), 0); + + memset(buf, 0x7C, sizeof(buf)); + ATF_REQUIRE_EQ(getrandom(buf, 255, 0), 255); + ATF_REQUIRE_EQ(memcmp(&buf[255], reference, sizeof(reference) - 255), 0); + + memset(buf, 0x7C, sizeof(buf)); + ATF_REQUIRE_EQ(getrandom(buf, 4095, 0), 4095); + ATF_REQUIRE_EQ(memcmp(&buf[4095], reference, sizeof(reference) - 4095), 0); +} + +ATF_TP_ADD_TCS(tp) +{ + + ATF_TP_ADD_TC(tp, getrandom_count); + ATF_TP_ADD_TC(tp, getrandom_fault); + ATF_TP_ADD_TC(tp, getrandom_randomness); + return (atf_no_error()); +} Modified: head/usr.bin/truss/syscalls.c ============================================================================== --- head/usr.bin/truss/syscalls.c Tue Mar 20 23:08:42 2018 (r331278) +++ head/usr.bin/truss/syscalls.c Wed Mar 21 01:15:45 2018 (r331279) @@ -259,6 +259,8 @@ static struct syscall decoded_syscalls[] = { .args = { { Int, 0 } } }, { .name = "getpriority", .ret_type = 1, .nargs = 2, .args = { { Priowhich, 0 }, { Int, 1 } } }, + { .name = "getrandom", .ret_type = 1, .nargs = 3, + .args = { { BinString | OUT, 0 }, { Sizet, 1 }, { UInt, 2 } } }, { .name = "getrlimit", .ret_type = 1, .nargs = 2, .args = { { Resource, 0 }, { Rlimit | OUT, 1 } } }, { .name = "getrusage", .ret_type = 1, .nargs = 2,
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