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Add new gets_s(3) stdio function.

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This implements the gets_s(3) function as documented at
http://en.cppreference.com/w/c/io/gets. It facilitates the
optional removal of gets(3).

Reviewed by:	ed
MFC after:	2 weeks
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D12785
This commit is contained in:
Cy Schubert 2018-04-03 18:52:38 +00:00
parent 362e958eec
commit a77546fbb3
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=331936
6 changed files with 275 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
lib/libc/stdio/Makefile.inc
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@ -14,7 +14,7 @@ SRCS+= _flock_stub.c asprintf.c clrerr.c dprintf.c \
fputwc.c fputws.c fread.c freopen.c fscanf.c fseek.c fsetpos.c \
ftell.c funopen.c fvwrite.c fwalk.c fwide.c fwprintf.c fwscanf.c \
fwrite.c getc.c getchar.c getdelim.c getline.c \
gets.c getw.c getwc.c getwchar.c makebuf.c mktemp.c \
gets.c gets_s.c getw.c getwc.c getwchar.c makebuf.c mktemp.c \
open_memstream.c open_wmemstream.c \
perror.c printf.c printf-pos.c putc.c putchar.c \
puts.c putw.c putwc.c putwchar.c \
@ -50,6 +50,7 @@ MLINKS+=ferror.3 ferror_unlocked.3 \
ferror.3 fileno.3 ferror.3 fileno_unlocked.3
MLINKS+=fflush.3 fpurge.3
MLINKS+=fgets.3 gets.3
MLINKS+=fgets.3 gets_s.3
MLINKS+=flockfile.3 ftrylockfile.3 flockfile.3 funlockfile.3
MLINKS+=fopen.3 fdopen.3 fopen.3 freopen.3 fopen.3 fmemopen.3
MLINKS+=fputs.3 puts.3

1
lib/libc/stdio/Symbol.map
View File

@ -165,6 +165,7 @@ FBSD_1.3 {
FBSD_1.4 {
fdclose;
fopencookie;
gets_s;
};
FBSDprivate_1.0 {

26
lib/libc/stdio/fgets.3
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@ -46,6 +46,8 @@
.Ft char *
.Fn fgets "char * restrict str" "int size" "FILE * restrict stream"
.Ft char *
.Fn gets_s "char *str" "rsize_t size"
.Ft char *
.Fn gets "char *str"
.Sh DESCRIPTION
The
@ -65,6 +67,17 @@ If any characters are read and there is no error, a
character is appended to end the string.
.Pp
The
.Fn gets_s
function
is equivalent to
.Fn fgets
with a
.Fa stream
of
.Dv stdin ,
except that the newline character (if any) is not stored in the string.
.Pp
The
.Fn gets
function
is equivalent to
@ -80,7 +93,8 @@ It is the caller's responsibility to ensure that the input line,
if any, is sufficiently short to fit in the string.
.Sh RETURN VALUES
Upon successful completion,
.Fn fgets
.Fn fgets ,
.Fn gets_s ,
and
.Fn gets
return
@ -94,7 +108,8 @@ they return
.Dv NULL
and the buffer contents are indeterminate.
The
.Fn fgets
.Fn fgets ,
.Fn gets_s ,
and
.Fn gets
functions
@ -141,6 +156,13 @@ and
.Fn gets
conform to
.St -isoC-99 .
.Fn gets_s
conforms to
.St -isoC-2011
K.3.7.4.1.
.Fn gets
has been removed from
.St -isoC-2011 .
.Sh SECURITY CONSIDERATIONS
The
.Fn gets

102
lib/libc/stdio/gets_s.c Normal file
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@ -0,0 +1,102 @@
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
* Copyright (c) 2017, 2018
* Cyril S. E. Schubert. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 "namespace.h"
#include <errno.h>
#include <unistd.h>
#include <stdint.h>
#include <stdio.h>
#include "un-namespace.h"
#include "libc_private.h"
#include "local.h"
static inline char *
_gets_s(char *buf, rsize_t n)
{
int c;
char *s;
ORIENT(stdin, -1);
for (s = buf, n--; (c = __sgetc(stdin)) != '\n' && n > 0 ; n--) {
if (c == EOF) {
if (s == buf) {
return (NULL);
} else
break;
} else
*s++ = c;
}
/*
* If end of buffer reached, discard until \n or eof.
* Then throw an error.
*/
if (n == 0) {
/* discard */
while ((c = __sgetc(stdin)) != '\n' && c != EOF);
/* throw the error after lock released prior to exit */
__throw_constraint_handler_s("gets_s : end of buffer", E2BIG);
return (NULL);
}
*s = 0;
return (buf);
}
/* ISO/IEC 9899:2011 K.3.7.4.1 */
char *
gets_s(char *buf, rsize_t n)
{
char *ret;
if (buf == NULL) {
__throw_constraint_handler_s("gets_s : str is NULL", EINVAL);
return(NULL);
} else if (n > RSIZE_MAX) {
__throw_constraint_handler_s("gets_s : n > RSIZE_MAX",
EINVAL);
return(NULL);
} else if (n == 0) {
__throw_constraint_handler_s("gets_s : n == 0", EINVAL);
return(NULL);
}
FLOCKFILE_CANCELSAFE(stdin);
ret = _gets_s(buf, n);
FUNLOCKFILE_CANCELSAFE();
return (ret);
}

1
lib/libc/tests/stdio/Makefile
View File

@ -7,6 +7,7 @@ ATF_TESTS_C+= fmemopen2_test
ATF_TESTS_C+= fopen2_test
ATF_TESTS_C+= freopen_test
ATF_TESTS_C+= getdelim_test
ATF_TESTS_C+= gets_s_test
ATF_TESTS_C+= mkostemp_test
ATF_TESTS_C+= open_memstream2_test
ATF_TESTS_C+= open_wmemstream_test

145
lib/libc/tests/stdio/gets_s_test.c Normal file
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@ -0,0 +1,145 @@
/*-
* Copyright (c) 2017 Cyril S. E. Schubert. 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 REGENTS 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 REGENTS 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 <assert.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/wait.h>
#include <atf-c.h>
static errno_t error_code;
static const char * message;
void
h(const char * msg, void * ptr __unused, errno_t error)
{
error_code = error;
message = msg;
}
/* null ptr */
ATF_TC_WITHOUT_HEAD(null_ptr);
ATF_TC_BODY(null_ptr, tc)
{
ATF_CHECK_MSG(gets_s(NULL, 1) == NULL,
"gets_s() failed to handle NULL pointer");
}
/* normal */
ATF_TC_WITHOUT_HEAD(normal);
ATF_TC_BODY(normal, tc)
{
pid_t kidpid;
int fd[2];
int nfd;
// close(STDIN_FILENO);
// close(STDOUT_FILENO);
pipe(fd);
if ((kidpid = fork()) == 0) {
char b[10];
close(fd[1]);
nfd = dup2(fd[0], 0);
close(fd[0]);
stdin = fdopen(nfd, "r");
ATF_CHECK_MSG(gets_s(b, sizeof(b)) == 0, "gets_s() normal failed");
fclose(stdin);
} else {
int stat;
close(fd[0]);
stdout = fdopen(fd[1], "w");
puts("a sting");
fclose(stdout);
(void) waitpid(kidpid, &stat, WEXITED);
}
}
/* n > rmax */
ATF_TC_WITHOUT_HEAD(n_gt_rmax);
ATF_TC_BODY(n_gt_rmax, tc)
{
char b;
ATF_CHECK_MSG(gets_s(&b, RSIZE_MAX + 1) == NULL,
"gets_s() n > RSIZE_MAX");
}
/* n == 0 */
ATF_TC_WITHOUT_HEAD(n_eq_zero);
ATF_TC_BODY(n_eq_zero, tc)
{
char b;
ATF_CHECK_MSG(gets_s(&b, 0) == NULL, "gets_s() n is zero");
}
/* n > rmax, handler */
ATF_TC_WITHOUT_HEAD(n_gt_rmax_handler);
ATF_TC_BODY(n_gt_rmax_handler, tc)
{
char b;
error_code = 0;
message = NULL;
set_constraint_handler_s(h);
ATF_CHECK_MSG(gets_s(&b, RSIZE_MAX + 1) == NULL, "gets_s() n > RSIZE_MAX");
ATF_CHECK_MSG(error_code > 0, "gets_s() error code is %d", error_code);
ATF_CHECK_MSG(strcmp(message, "gets_s : n > RSIZE_MAX") == 0, "gets_s(): incorrect error message");
}
/* n == 0, handler */
ATF_TC_WITHOUT_HEAD(n_eq_zero_handler);
ATF_TC_BODY(n_eq_zero_handler, tc)
{
char b;
error_code = 0;
message = NULL;
set_constraint_handler_s(h);
ATF_CHECK(gets_s(&b, 0) == NULL);
ATF_CHECK_MSG(error_code > 0, "gets_s() error code is %d", error_code);
ATF_CHECK_MSG(strcmp(message, "gets_s : n == 0") == 0, "gets_s(): incorrect error message");
}
ATF_TP_ADD_TCS(tp)
{
ATF_TP_ADD_TC(tp, null_ptr);
ATF_TP_ADD_TC(tp, normal);
ATF_TP_ADD_TC(tp, n_gt_rmax);
ATF_TP_ADD_TC(tp, n_eq_zero);
ATF_TP_ADD_TC(tp, n_gt_rmax_handler);
ATF_TP_ADD_TC(tp, n_eq_zero_handler);
return (atf_no_error());
}