1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
/*
* Copyright (c) 2004-2005, 2007, 2010, 2012-2015, 2017-2018
* Todd C. Miller <Todd.Miller@sudo.ws>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/*
* This is an open source non-commercial project. Dear PVS-Studio, please check it.
* PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
*/
#include <config.h>
#ifndef HAVE_CLOSEFROM
#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <limits.h>
#ifdef HAVE_PSTAT_GETPROC
# include <sys/pstat.h>
#else
# include <dirent.h>
#endif
#include "sudo_compat.h"
#include "pathnames.h"
#ifndef _POSIX_OPEN_MAX
# define _POSIX_OPEN_MAX 20
#endif
/*
* Close all file descriptors greater than or equal to lowfd.
* This is the expensive (fallback) method.
*/
static void
closefrom_fallback(int lowfd)
{
long fd, maxfd;
/*
* Fall back on sysconf(_SC_OPEN_MAX). We avoid checking
* resource limits since it is possible to open a file descriptor
* and then drop the rlimit such that it is below the open fd.
*/
maxfd = sysconf(_SC_OPEN_MAX);
if (maxfd < 0)
maxfd = _POSIX_OPEN_MAX;
for (fd = lowfd; fd < maxfd; fd++) {
#ifdef __APPLE__
/* Avoid potential libdispatch crash when we close its fds. */
(void) fcntl((int) fd, F_SETFD, FD_CLOEXEC);
#else
(void) close((int) fd);
#endif
}
}
/*
* Close all file descriptors greater than or equal to lowfd.
* We try the fast way first, falling back on the slow method.
*/
void
sudo_closefrom(int lowfd)
{
#if defined(HAVE_PSTAT_GETPROC)
struct pst_status pstat;
#elif defined(HAVE_DIRFD)
const char *path;
DIR *dirp;
#endif
/* Try the fast method first, if possible. */
#if defined(HAVE_FCNTL_CLOSEM)
if (fcntl(lowfd, F_CLOSEM, 0) != -1)
return;
#endif
#if defined(HAVE_PSTAT_GETPROC)
if (pstat_getproc(&pstat, sizeof(pstat), 0, getpid()) != -1) {
int fd;
for (fd = lowfd; fd <= pstat.pst_highestfd; fd++)
(void) close(fd);
return;
}
#elif defined(HAVE_DIRFD)
/* Use /proc/self/fd (or /dev/fd on FreeBSD) if it exists. */
# if defined(__FreeBSD__) || defined(__APPLE__)
path = _PATH_DEV "fd";
# else
path = "/proc/self/fd";
# endif
if ((dirp = opendir(path)) != NULL) {
struct dirent *dent;
while ((dent = readdir(dirp)) != NULL) {
const char *errstr;
int fd = strtonum(dent->d_name, lowfd, INT_MAX, &errstr);
if (errstr == NULL && fd != dirfd(dirp)) {
# ifdef __APPLE__
/* Avoid potential libdispatch crash when we close its fds. */
(void) fcntl(fd, F_SETFD, FD_CLOEXEC);
# else
(void) close(fd);
# endif
}
}
(void) closedir(dirp);
return;
}
#endif /* HAVE_DIRFD */
/* Do things the slow way. */
closefrom_fallback(lowfd);
}
#endif /* HAVE_CLOSEFROM */
|
