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
132
133
134
135
136
137
138
139
140
141
142
143
|
/*
* SPDX-License-Identifier: ISC
*
* 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 <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <unistd.h>
#ifdef HAVE_PSTAT_GETPROC
# include <sys/pstat.h>
#else
# include <dirent.h>
#endif
#include "sudo_compat.h"
#include "sudo_util.h"
#include "pathnames.h"
#ifndef OPEN_MAX
# define OPEN_MAX 256
#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). This is equivalent to
* checking the RLIMIT_NOFILE soft limit. It is possible for
* there to be open file descriptors past this limit but there's
* not much we can do about that since the hard limit may be
* RLIM_INFINITY (LLONG_MAX or ULLONG_MAX on modern systems).
*/
maxfd = sysconf(_SC_OPEN_MAX);
if (maxfd < OPEN_MAX)
maxfd = OPEN_MAX;
/* Make sure we didn't get RLIM_INFINITY as the upper limit. */
if (maxfd > INT_MAX)
maxfd = INT_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 pst;
#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)
/*
* EOVERFLOW is not a fatal error for the fields we use.
* See the "EOVERFLOW Error" section of pstat_getvminfo(3).
*/
if (pstat_getproc(&pst, sizeof(pst), 0, getpid()) != -1 ||
errno == EOVERFLOW) {
int fd;
for (fd = lowfd; fd <= pst.pst_highestfd; fd++)
(void) close(fd);
return;
}
#elif defined(HAVE_DIRFD)
/* Use /proc/self/fd (or /dev/fd on macOS) if it exists. */
# ifdef __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 = sudo_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 */
|
