1 /* This file is part of GNU Pies
2 Copyright (C) 2015-2020 Sergey Poznyakoff
3
4 GNU Pies is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 3, or (at your option)
7 any later version.
8
9 GNU Pies is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with GNU Pies. If not, see <http://www.gnu.org/licenses/>. */
16
17 #include <config.h>
18 #include <stdlib.h>
19 #include <unistd.h>
20 #include "libpies.h"
21
22 #if defined (HAVE_FUNC_CLOSEFROM)
23 # include <unistd.h>
24
25 static int
close_fds_sys(int minfd)26 close_fds_sys (int minfd)
27 {
28 closefrom (minfd);
29 return 0;
30 }
31
32 #elif defined (HAVE_FCNTL_CLOSEM)
33 # include <fcntl.h>
34
35 static int
close_fds_sys(int minfd)36 close_fds_sys (int minfd)
37 {
38 fcntl (minfd, F_CLOSEM, 0);
39 return 0;
40 }
41
42 #elif defined (HAVE_LIBPROC_H) && defined (HAVE_FUNC_PROC_PIDINFO)
43 #include <libproc.h>
44
45 static int
close_fds_sys(int minfd)46 close_fds_sys (int minfd)
47 {
48 pid_t pid = getpid ();
49 struct proc_fdinfo *fdinfo;
50 int i, n, size;
51
52 size = proc_pidinfo (pid, PROC_PIDLISTFDS, 0, NULL, 0);
53 if (size == 0)
54 return 0;
55 else if (size < 0)
56 return -1;
57
58 fdinfo = calloc (size, sizeof (fdinfo[0]));
59 if (!fdinfo)
60 return -1;
61
62 n = proc_pidinfo (pid, PROC_PIDLISTFDS, 0, fdinfo, size);
63 if (n <= 0)
64 {
65 free (fdinfo);
66 return -1;
67 }
68
69 n /= PROC_PIDLISTFD_SIZE;
70
71 for (i = 0; i < n; i++)
72 {
73 if (fdinfo_buf[i].proc_fd >= minfd)
74 close (fdinfo_buf[i].proc_fd);
75 }
76
77 free (fdinfo);
78 return 0;
79 }
80
81 #elif defined (HAVE_PROC_SELF_FD)
82 # include <sys/types.h>
83 # include <dirent.h>
84 # include <limits.h>
85
86 static int
close_fds_sys(int minfd)87 close_fds_sys (int minfd)
88 {
89 DIR *dir;
90 struct dirent *ent;
91
92 dir = opendir ("/proc/self/fd");
93 if (!dir)
94 return -1;
95 while ((ent = readdir (dir)) != NULL)
96 {
97 long n;
98 char *p;
99
100 if (ent->d_name[0] == '.')
101 continue;
102
103 n = strtol (ent->d_name, &p, 10);
104 if (n >= minfd && n < INT_MAX && *p == 0)
105 close ((int) n);
106 }
107 closedir (dir);
108 return 0;
109 }
110
111 #else
112 # define close_fds_sys(fd) (-1)
113 #endif
114
115 static int
close_fds_bruteforce(int minfd)116 close_fds_bruteforce (int minfd)
117 {
118 int i, n = getmaxfd ();
119
120 for (i = minfd; i < n; i++)
121 close (i);
122
123 return 0;
124 }
125
126 void
pies_close_fds(int minfd)127 pies_close_fds (int minfd)
128 {
129 if (close_fds_sys (minfd))
130 close_fds_bruteforce (minfd);
131 }
132