freebsd-nq/usr.bin/tail/misc.c
Mariusz Zaborski c851fce6d7 tail: fix the checks if the file was rotated
The freopen(3) was replaced with fileargs_open(3) and fclose(3).
In the following function, we skip if the stream is standard in, so it is
safe to do so.
This also requires us to change the logic first to open the file and then
check its status. The stat(2) is disallowed in capability mode.

This commit unbrakes the -F option.
The bug was introduced in the r348708.

Reported by:	pho
Tested by:	pho
2019-06-09 22:55:21 +00:00

135 lines
3.5 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Edward Sze-Tyan Wang.
*
* 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("$FreeBSD$");
#ifndef lint
static const char sccsid[] = "@(#)misc.c 8.1 (Berkeley) 6/6/93";
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libcasper.h>
#include <casper/cap_fileargs.h>
#include "extern.h"
void
ierr(const char *fname)
{
warn("%s", fname);
rval = 1;
}
void
oerr(void)
{
err(1, "stdout");
}
/*
* Print `len' bytes from the file associated with `mip', starting at
* absolute file offset `startoff'. May move map window.
*/
int
mapprint(struct mapinfo *mip, off_t startoff, off_t len)
{
int n;
while (len > 0) {
if (startoff < mip->mapoff || startoff >= mip->mapoff +
(off_t)mip->maplen) {
if (maparound(mip, startoff) != 0)
return (1);
}
n = (mip->mapoff + mip->maplen) - startoff;
if (n > len)
n = len;
WR(mip->start + (startoff - mip->mapoff), n);
startoff += n;
len -= n;
}
return (0);
}
/*
* Move the map window so that it contains the byte at absolute file
* offset `offset'. The start of the map window will be TAILMAPLEN
* aligned.
*/
int
maparound(struct mapinfo *mip, off_t offset)
{
if (mip->start != NULL && munmap(mip->start, mip->maplen) != 0)
return (1);
mip->mapoff = offset & ~((off_t)TAILMAPLEN - 1);
mip->maplen = TAILMAPLEN;
if ((off_t)mip->maplen > mip->maxoff - mip->mapoff)
mip->maplen = mip->maxoff - mip->mapoff;
if (mip->maplen <= 0)
abort();
if ((mip->start = mmap(NULL, mip->maplen, PROT_READ, MAP_SHARED,
mip->fd, mip->mapoff)) == MAP_FAILED)
return (1);
return (0);
}
/*
* Print the file name without stdio buffering.
*/
void
printfn(const char *fn, int print_nl)
{
if (print_nl)
WR("\n", 1);
WR("==> ", 4);
WR(fn, strlen(fn));
WR(" <==\n", 5);
}