NetBSD/usr.bin/vndcompress/utils.c

165 lines
4.0 KiB
C

/* $NetBSD: utils.c,v 1.2 2014/01/22 06:15:04 riastradh Exp $ */
/*-
* Copyright (c) 2013 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Taylor R. Campbell.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
__RCSID("$NetBSD: utils.c,v 1.2 2014/01/22 06:15:04 riastradh Exp $");
#include <sys/types.h>
#include <assert.h>
#include <err.h>
#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
/* XXX Seems to be missing from <stdio.h>... */
int snprintf_ss(char *restrict, size_t, const char *restrict, ...)
__printflike(3, 4);
int vsnprintf_ss(char *restrict, size_t, const char *restrict, va_list)
__printflike(3, 0);
#include "utils.h"
/*
* Read, returning partial data only at end of file.
*/
ssize_t
read_block(int fd, void *buffer, size_t n)
{
char *p = buffer, *const end __unused = (p + n);
size_t total_read = 0;
while (n > 0) {
const ssize_t n_read = read(fd, p, n);
if (n_read == -1)
return -1;
assert(n_read >= 0);
if (n_read == 0)
break;
assert((size_t)n_read <= n);
n -= (size_t)n_read;
assert(p <= end);
assert(n_read <= (end - p));
p += (size_t)n_read;
assert((size_t)n_read <= (SIZE_MAX - total_read));
total_read += (size_t)n_read;
}
return total_read;
}
/*
* Signal-safe err/warn utilities. The errno varieties are limited to
* having no format arguments for reasons of laziness.
*/
void
err_ss(int exit_value, const char *msg)
{
warn_ss(msg);
_Exit(exit_value);
}
void
errx_ss(int exit_value, const char *format, ...)
{
va_list va;
va_start(va, format);
vwarnx_ss(format, va);
va_end(va);
_Exit(exit_value);
}
void
warn_ss(const char *msg)
{
int error = errno;
warnx_ss("%s: %s", msg, strerror(error));
errno = error;
}
void
warnx_ss(const char *format, ...)
{
va_list va;
va_start(va, format);
vwarnx_ss(format, va);
va_end(va);
}
void
vwarnx_ss(const char *format, va_list va)
{
char buf[128];
(void)strlcpy(buf, getprogname(), sizeof(buf));
(void)strlcat(buf, ": ", sizeof(buf));
const int n = vsnprintf_ss(&buf[strlen(buf)], (sizeof(buf) -
strlen(buf)), format, va);
if (n <= 0) {
const char fallback[] =
"vndcompress: Help! I'm trapped in a signal handler!\n";
(void)write(STDERR_FILENO, fallback, __arraycount(fallback));
} else {
(void)strlcat(buf, "\n", sizeof(buf));
(void)write(STDERR_FILENO, buf, strlen(buf));
}
}
void
block_signals(sigset_t *old_sigmask)
{
sigset_t block;
(void)sigfillset(&block);
(void)sigprocmask(SIG_BLOCK, &block, old_sigmask);
}
void
restore_sigmask(const sigset_t *sigmask)
{
(void)sigprocmask(SIG_SETMASK, sigmask, NULL);
}