1/*-
2 * Copyright (c) 2017 M. Warner Losh <imp@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#define _WANT_FREEBSD11_DIRENT
31
32#include "namespace.h"
33#include <sys/param.h>
34#include <sys/syscall.h>
35#include "compat-ino64.h"
36#include <dirent.h>
37#include <errno.h>
38#include <stddef.h>
39#include <stdlib.h>
40#include <stdio.h>
41#include <string.h>
42#include <unistd.h>
43#include "libc_private.h"
44
45static ssize_t
46__cvt_dirents_from11(const char *de11, ssize_t len11, char *de, ssize_t len)
47{
48	struct dirent *dst;
49	const struct freebsd11_dirent *src;
50	const char *edst, *esrc;
51	ssize_t rlen;
52
53	src = (const struct freebsd11_dirent *)de11;
54	dst = (struct dirent *)de;
55	esrc = de11 + len11;
56	edst = de + len;
57	while ((const char *)src < esrc && (const char *)dst < edst) {
58		rlen = roundup(offsetof(struct dirent, d_name) + src->d_namlen + 1, 8);
59		if ((const char *)dst + rlen >= edst)
60			break;
61		dst->d_fileno = src->d_fileno;
62		dst->d_off = 0;			/* nothing uses it yet, so safe for now */
63		dst->d_reclen = rlen;
64		dst->d_type = src->d_type;
65		dst->d_pad0 = 0;
66		dst->d_namlen = src->d_namlen;
67		dst->d_pad1 = 0;
68		memset(dst->d_name, 0, roundup(src->d_namlen + 1, 8));
69		memcpy(dst->d_name, src->d_name, src->d_namlen);
70		dst = (struct dirent *)((char *)dst + rlen);
71		src = (const struct freebsd11_dirent *)((const char *)src + src->d_reclen);
72	}
73	return ((char *)dst - de);
74}
75
76#undef getdirentries
77__weak_reference(_getdirentries, getdirentries);
78
79#pragma weak _getdirentries
80ssize_t
81_getdirentries(int fd, char *buf, size_t nbytes, off_t *basep)
82{
83	char *oldbuf;
84	size_t len;
85	ssize_t rv;
86
87	if (__getosreldate() >= INO64_FIRST)
88		return (__sys_getdirentries(fd, buf, nbytes, basep));
89
90	/*
91	 * Because the old system call returns entries that are smaller than the
92	 * new, we could wind up in a situation where we have too many to fit in
93	 * the buffer with the new encoding. So sacrifice a small bit of
94	 * efficiency to ensure that never happens. We pick 1/4 the size round
95	 * up to the next DIRBLKSIZ. This will guarnatee enough room exists in
96	 * the dst buffer due to changes in efficiency in packing dirent
97	 * entries. We don't check against minimum block size to avoid a lot of
98	 * stat calls, we'll see if that's wise or not.
99	 * TBD: Will this difference matter to lseek?
100	 */
101	len = roundup(nbytes / 4, DIRBLKSIZ);
102	oldbuf = malloc(len);
103	if (oldbuf == NULL) {
104		errno = EINVAL;		/* ENOMEM not in possible list */
105		return (-1);
106	}
107	rv = syscall(SYS_freebsd11_getdirentries, fd, oldbuf, len, basep);
108	if (rv == -1) {
109		free(oldbuf);
110		return (rv);
111	}
112	if (rv > 0)
113		rv = __cvt_dirents_from11(oldbuf, rv, buf, nbytes);
114	free(oldbuf);
115
116	return (rv);
117}
118