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git.proxmox.com Git - systemd.git/blob - src/import/import-common.c
1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2015 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
23 #include <sys/prctl.h>
27 #include "btrfs-util.h"
28 #include "capability.h"
29 #include "signal-util.h"
31 #include "import-common.h"
33 int import_make_read_only_fd(int fd
) {
38 /* First, let's make this a read-only subvolume if it refers
40 r
= btrfs_subvol_set_read_only_fd(fd
, true);
41 if (r
== -ENOTTY
|| r
== -ENOTDIR
|| r
== -EINVAL
) {
44 /* This doesn't refer to a subvolume, or the file
45 * system isn't even btrfs. In that, case fall back to
50 return log_error_errno(errno
, "Failed to stat temporary image: %m");
53 if (fchmod(fd
, st
.st_mode
& 07555) < 0)
54 return log_error_errno(errno
, "Failed to chmod() final image: %m");
59 return log_error_errno(r
, "Failed to make subvolume read-only: %m");
64 int import_make_read_only(const char *path
) {
65 _cleanup_close_
int fd
= 1;
67 fd
= open(path
, O_RDONLY
|O_NOCTTY
|O_CLOEXEC
);
69 return log_error_errno(errno
, "Failed to open %s: %m", path
);
71 return import_make_read_only_fd(fd
);
74 int import_fork_tar_x(const char *path
, pid_t
*ret
) {
75 _cleanup_close_pair_
int pipefd
[2] = { -1, -1 };
82 if (pipe2(pipefd
, O_CLOEXEC
) < 0)
83 return log_error_errno(errno
, "Failed to create pipe for tar: %m");
87 return log_error_errno(errno
, "Failed to fork off tar: %m");
93 (1ULL << CAP_FOWNER
) |
94 (1ULL << CAP_FSETID
) |
96 (1ULL << CAP_SETFCAP
) |
97 (1ULL << CAP_DAC_OVERRIDE
);
101 (void) reset_all_signal_handlers();
102 (void) reset_signal_mask();
103 assert_se(prctl(PR_SET_PDEATHSIG
, SIGTERM
) == 0);
105 pipefd
[1] = safe_close(pipefd
[1]);
107 if (dup2(pipefd
[0], STDIN_FILENO
) != STDIN_FILENO
) {
108 log_error_errno(errno
, "Failed to dup2() fd: %m");
112 if (pipefd
[0] != STDIN_FILENO
)
113 pipefd
[0] = safe_close(pipefd
[0]);
115 null_fd
= open("/dev/null", O_WRONLY
|O_NOCTTY
);
117 log_error_errno(errno
, "Failed to open /dev/null: %m");
121 if (dup2(null_fd
, STDOUT_FILENO
) != STDOUT_FILENO
) {
122 log_error_errno(errno
, "Failed to dup2() fd: %m");
126 if (null_fd
!= STDOUT_FILENO
)
127 null_fd
= safe_close(null_fd
);
129 fd_cloexec(STDIN_FILENO
, false);
130 fd_cloexec(STDOUT_FILENO
, false);
131 fd_cloexec(STDERR_FILENO
, false);
133 if (unshare(CLONE_NEWNET
) < 0)
134 log_error_errno(errno
, "Failed to lock tar into network namespace, ignoring: %m");
136 r
= capability_bounding_set_drop(~retain
, true);
138 log_error_errno(r
, "Failed to drop capabilities, ignoring: %m");
140 execlp("tar", "tar", "--numeric-owner", "-C", path
, "-px", NULL
);
141 log_error_errno(errno
, "Failed to execute tar: %m");
145 pipefd
[0] = safe_close(pipefd
[0]);
154 int import_fork_tar_c(const char *path
, pid_t
*ret
) {
155 _cleanup_close_pair_
int pipefd
[2] = { -1, -1 };
162 if (pipe2(pipefd
, O_CLOEXEC
) < 0)
163 return log_error_errno(errno
, "Failed to create pipe for tar: %m");
167 return log_error_errno(errno
, "Failed to fork off tar: %m");
171 uint64_t retain
= (1ULL << CAP_DAC_OVERRIDE
);
175 (void) reset_all_signal_handlers();
176 (void) reset_signal_mask();
177 assert_se(prctl(PR_SET_PDEATHSIG
, SIGTERM
) == 0);
179 pipefd
[0] = safe_close(pipefd
[0]);
181 if (dup2(pipefd
[1], STDOUT_FILENO
) != STDOUT_FILENO
) {
182 log_error_errno(errno
, "Failed to dup2() fd: %m");
186 if (pipefd
[1] != STDOUT_FILENO
)
187 pipefd
[1] = safe_close(pipefd
[1]);
189 null_fd
= open("/dev/null", O_RDONLY
|O_NOCTTY
);
191 log_error_errno(errno
, "Failed to open /dev/null: %m");
195 if (dup2(null_fd
, STDIN_FILENO
) != STDIN_FILENO
) {
196 log_error_errno(errno
, "Failed to dup2() fd: %m");
200 if (null_fd
!= STDIN_FILENO
)
201 null_fd
= safe_close(null_fd
);
203 fd_cloexec(STDIN_FILENO
, false);
204 fd_cloexec(STDOUT_FILENO
, false);
205 fd_cloexec(STDERR_FILENO
, false);
207 if (unshare(CLONE_NEWNET
) < 0)
208 log_error_errno(errno
, "Failed to lock tar into network namespace, ignoring: %m");
210 r
= capability_bounding_set_drop(~retain
, true);
212 log_error_errno(r
, "Failed to drop capabilities, ignoring: %m");
214 execlp("tar", "tar", "-C", path
, "-c", ".", NULL
);
215 log_error_errno(errno
, "Failed to execute tar: %m");
219 pipefd
[1] = safe_close(pipefd
[1]);