summaryrefslogtreecommitdiff
path: root/src/core/smack-setup.c
blob: 59f6832bc21feae660a365f8fd9c0907d56683dd (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
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

/***
  This file is part of systemd.

  Copyright (C) 2013 Intel Corporation
  Authors:
        Nathaniel Chen <nathaniel.chen@intel.com>

  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 <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/vfs.h>
#include <fcntl.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/mount.h>
#include <stdint.h>

#include "macro.h"
#include "smack-setup.h"
#include "util.h"
#include "fileio.h"
#include "log.h"
#include "label.h"

#define SMACK_CONFIG "/etc/smack/accesses.d/"
#define CIPSO_CONFIG "/etc/smack/cipso.d/"

#ifdef HAVE_SMACK

static int write_rules(const char* dstpath, const char* srcdir) {
        _cleanup_fclose_ FILE *dst = NULL;
        _cleanup_closedir_ DIR *dir = NULL;
        struct dirent *entry;
        char buf[NAME_MAX];
        int dfd = -1;
        int r = 0;

        dst = fopen(dstpath, "we");
        if (!dst)  {
                if (errno != ENOENT)
                        log_warning_errno(errno, "Failed to open %s: %m", dstpath);
                return -errno; /* negative error */
        }

        /* write rules to dst from every file in the directory */
        dir = opendir(srcdir);
        if (!dir) {
                if (errno != ENOENT)
                        log_warning_errno(errno, "Failed to opendir %s: %m", srcdir);
                return errno; /* positive on purpose */
        }

        dfd = dirfd(dir);
        assert(dfd >= 0);

        FOREACH_DIRENT(entry, dir, return 0) {
                int fd;
                _cleanup_fclose_ FILE *policy = NULL;

                fd = openat(dfd, entry->d_name, O_RDONLY|O_CLOEXEC);
                if (fd < 0) {
                        if (r == 0)
                                r = -errno;
                        log_warning_errno(errno, "Failed to open %s: %m", entry->d_name);
                        continue;
                }

                policy = fdopen(fd, "re");
                if (!policy) {
                        if (r == 0)
                                r = -errno;
                        safe_close(fd);
                        log_error_errno(errno, "Failed to open %s: %m", entry->d_name);
                        continue;
                }

                /* load2 write rules in the kernel require a line buffered stream */
                FOREACH_LINE(buf, policy,
                             log_error_errno(errno, "Failed to read line from %s: %m",
                                       entry->d_name)) {
                        if (!fputs(buf, dst)) {
                                if (r == 0)
                                        r = -EINVAL;
                                log_error("Failed to write line to %s", dstpath);
                                break;
                        }
                        if (fflush(dst)) {
                                if (r == 0)
                                        r = -errno;
                                log_error_errno(errno, "Failed to flush writes to %s: %m", dstpath);
                                break;
                        }
                }
        }

       return r;
}

#endif

int mac_smack_setup(bool *loaded_policy) {

#ifdef HAVE_SMACK

        int r;

        assert(loaded_policy);

        r = write_rules("/sys/fs/smackfs/load2", SMACK_CONFIG);
        switch(r) {
        case -ENOENT:
                log_debug("Smack is not enabled in the kernel.");
                return 0;
        case ENOENT:
                log_debug("Smack access rules directory " SMACK_CONFIG " not found");
                return 0;
        case 0:
                log_info("Successfully loaded Smack policies.");
                break;
        default:
                log_warning("Failed to load Smack access rules: %s, ignoring.",
                            strerror(abs(r)));
                return 0;
        }

#ifdef SMACK_RUN_LABEL
        r = write_string_file("/proc/self/attr/current", SMACK_RUN_LABEL);
        if (r)
                log_warning("Failed to set SMACK label \"%s\" on self: %s",
                            SMACK_RUN_LABEL, strerror(-r));
#endif

        r = write_rules("/sys/fs/smackfs/cipso2", CIPSO_CONFIG);
        switch(r) {
        case -ENOENT:
                log_debug("Smack/CIPSO is not enabled in the kernel.");
                return 0;
        case ENOENT:
                log_debug("Smack/CIPSO access rules directory " CIPSO_CONFIG " not found");
                return 0;
        case 0:
                log_info("Successfully loaded Smack/CIPSO policies.");
                break;
        default:
                log_warning("Failed to load Smack/CIPSO access rules: %s, ignoring.",
                            strerror(abs(r)));
                return 0;
        }

        *loaded_policy = true;

#endif

        return 0;
}