freebsd-dev/lib/libc/sys/getdirentries.c
Warner Losh f86e60008b Regularize my copyright notice
o Remove All Rights Reserved from my notices
o imp@FreeBSD.org everywhere
o regularize punctiation, eliminate date ranges
o Make sure that it's clear that I don't claim All Rights reserved by listing
  All Rights Reserved on same line as other copyright holders (but not
  me). Other such holders are also listed last where it's clear.
2019-12-04 16:56:11 +00:00

117 lines
3.9 KiB
C

/*-
* Copyright (c) 2017 M. Warner Losh <imp@FreeBSD.org>
*
* 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("$FreeBSD$");
#define _WANT_FREEBSD11_DIRENT
#include "namespace.h"
#include <sys/param.h>
#include <sys/syscall.h>
#include "compat-ino64.h"
#include <dirent.h>
#include <errno.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "libc_private.h"
static ssize_t
__cvt_dirents_from11(const char *de11, ssize_t len11, char *de, ssize_t len)
{
struct dirent *dst;
const struct freebsd11_dirent *src;
const char *edst, *esrc;
ssize_t rlen;
src = (const struct freebsd11_dirent *)de11;
dst = (struct dirent *)de;
esrc = de11 + len11;
edst = de + len;
while ((const char *)src < esrc && (const char *)dst < edst) {
rlen = roundup(offsetof(struct dirent, d_name) + src->d_namlen + 1, 8);
if ((const char *)dst + rlen >= edst)
break;
dst->d_fileno = src->d_fileno;
dst->d_off = 0; /* nothing uses it yet, so safe for now */
dst->d_reclen = rlen;
dst->d_type = src->d_type;
dst->d_pad0 = 0;
dst->d_namlen = src->d_namlen;
dst->d_pad1 = 0;
memset(dst->d_name, 0, roundup(src->d_namlen + 1, 8));
memcpy(dst->d_name, src->d_name, src->d_namlen);
dst = (struct dirent *)((char *)dst + rlen);
src = (const struct freebsd11_dirent *)((const char *)src + src->d_reclen);
}
return ((char *)dst - de);
}
#undef getdirentries
__weak_reference(_getdirentries, getdirentries);
#pragma weak _getdirentries
ssize_t
_getdirentries(int fd, char *buf, size_t nbytes, off_t *basep)
{
char *oldbuf;
size_t len;
ssize_t rv;
if (__getosreldate() >= INO64_FIRST)
return (__sys_getdirentries(fd, buf, nbytes, basep));
/*
* Because the old system call returns entries that are smaller than the
* new, we could wind up in a situation where we have too many to fit in
* the buffer with the new encoding. So sacrifice a small bit of
* efficiency to ensure that never happens. We pick 1/4 the size round
* up to the next DIRBLKSIZ. This will guarnatee enough room exists in
* the dst buffer due to changes in efficiency in packing dirent
* entries. We don't check against minimum block size to avoid a lot of
* stat calls, we'll see if that's wise or not.
* TBD: Will this difference matter to lseek?
*/
len = roundup(nbytes / 4, DIRBLKSIZ);
oldbuf = malloc(len);
if (oldbuf == NULL) {
errno = EINVAL; /* ENOMEM not in possible list */
return (-1);
}
rv = syscall(SYS_freebsd11_getdirentries, fd, oldbuf, len, basep);
if (rv == -1) {
free(oldbuf);
return (rv);
}
if (rv > 0)
rv = __cvt_dirents_from11(oldbuf, rv, buf, nbytes);
free(oldbuf);
return (rv);
}