summaryrefslogtreecommitdiff
path: root/src/basic/fd-util.h
blob: 0f5a950f175a7a6fb7feb673f3e857ba4105f136 (plain)
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
/* SPDX-License-Identifier: LGPL-2.1+ */
#pragma once

/***
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <dirent.h>
#include <stdbool.h>
#include <stdio.h>
#include <sys/socket.h>

#include "macro.h"

/* Make sure we can distinguish fd 0 and NULL */
#define FD_TO_PTR(fd) INT_TO_PTR((fd)+1)
#define PTR_TO_FD(p) (PTR_TO_INT(p)-1)

int close_nointr(int fd);
int safe_close(int fd);
void safe_close_pair(int p[]);

static inline int safe_close_above_stdio(int fd) {
        if (fd < 3) /* Don't close stdin/stdout/stderr, but still invalidate the fd by returning -1 */
                return -1;

        return safe_close(fd);
}

void close_many(const int fds[], unsigned n_fd);

int fclose_nointr(FILE *f);
FILE* safe_fclose(FILE *f);
#if 0 /// UNNEEDED by elogind
DIR* safe_closedir(DIR *f);
#endif // 0

static inline void closep(int *fd) {
        safe_close(*fd);
}

static inline void close_pairp(int (*p)[2]) {
        safe_close_pair(*p);
}

static inline void fclosep(FILE **f) {
        safe_fclose(*f);
}

DEFINE_TRIVIAL_CLEANUP_FUNC(FILE*, pclose);
DEFINE_TRIVIAL_CLEANUP_FUNC(DIR*, closedir);

#define _cleanup_close_ _cleanup_(closep)
#define _cleanup_fclose_ _cleanup_(fclosep)
#define _cleanup_pclose_ _cleanup_(pclosep)
#define _cleanup_closedir_ _cleanup_(closedirp)
#define _cleanup_close_pair_ _cleanup_(close_pairp)

int fd_nonblock(int fd, bool nonblock);
int fd_cloexec(int fd, bool cloexec);

int close_all_fds(const int except[], unsigned n_except);

#if 0 /// UNNEEDED by elogind
int same_fd(int a, int b);

void cmsg_close_all(struct msghdr *mh);

bool fdname_is_valid(const char *s);
#endif // 0

int fd_get_path(int fd, char **ret);

int move_fd(int from, int to, int cloexec);

enum {
        ACQUIRE_NO_DEV_NULL = 1 << 0,
        ACQUIRE_NO_MEMFD    = 1 << 1,
        ACQUIRE_NO_PIPE     = 1 << 2,
        ACQUIRE_NO_TMPFILE  = 1 << 3,
        ACQUIRE_NO_REGULAR  = 1 << 4,
};

int acquire_data_fd(const void *data, size_t size, unsigned flags);

/* Hint: ENETUNREACH happens if we try to connect to "non-existing" special IP addresses, such as ::5 */
#define ERRNO_IS_DISCONNECT(r) \
        IN_SET(r, ENOTCONN, ECONNRESET, ECONNREFUSED, ECONNABORTED, EPIPE, ENETUNREACH)

int fd_move_above_stdio(int fd);

int rearrange_stdio(int original_input_fd, int original_output_fd, int original_error_fd);

static inline int make_null_stdio(void) {
        return rearrange_stdio(-1, -1, -1);
}

/* Like TAKE_PTR() but for file descriptors, resetting them to -1 */
#define TAKE_FD(fd)                             \
        ({                                      \
                int _fd_ = (fd);                \
                (fd) = -1;                      \
                _fd_;                           \
        })

int fd_reopen(int fd, int flags);