summaryrefslogtreecommitdiff
path: root/src/basic/exec-util.c
blob: 468c247c670a2db218b4af557ba6a5242211ec5d (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
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
/* SPDX-License-Identifier: LGPL-2.1+ */

#include <dirent.h>
#include <errno.h>
#include <sys/prctl.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>

#include "alloc-util.h"
#include "conf-files.h"
#include "env-util.h"
#include "exec-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "hashmap.h"
#include "macro.h"
#include "process-util.h"
#include "set.h"
#include "signal-util.h"
#include "stat-util.h"
#include "string-util.h"
#include "strv.h"
#include "terminal-util.h"
#include "util.h"

/* Put this test here for a lack of better place */
assert_cc(EAGAIN == EWOULDBLOCK);

static int do_spawn(const char *path, char *argv[], int stdout_fd, pid_t *pid) {

        pid_t _pid;
        int r;

        if (null_or_empty_path(path)) {
                log_debug("%s is empty (a mask).", path);
                return 0;
        }

        r = safe_fork("(direxec)", FORK_DEATHSIG|FORK_LOG, &_pid);
        if (r < 0)
                return r;
        if (r == 0) {
                char *_argv[2];

                if (stdout_fd >= 0) {
                        r = rearrange_stdio(STDIN_FILENO, stdout_fd, STDERR_FILENO);
                        if (r < 0)
                                _exit(EXIT_FAILURE);
                }

                if (!argv) {
                        _argv[0] = (char*) path;
                        _argv[1] = NULL;
                        argv = _argv;
                } else
                        argv[0] = (char*) path;

                execv(path, argv);
                log_error_errno(errno, "Failed to execute %s: %m", path);
                _exit(EXIT_FAILURE);
        }

        *pid = _pid;
        return 1;
}

static int do_execute(
                char **directories,
                usec_t timeout,
                gather_stdout_callback_t const callbacks[_STDOUT_CONSUME_MAX],
                void* const callback_args[_STDOUT_CONSUME_MAX],
                int output_fd,
                char *argv[],
                char *envp[]) {

        _cleanup_hashmap_free_free_ Hashmap *pids = NULL;
        _cleanup_strv_free_ char **paths = NULL;
        char **path, **e;
        int r;

        /* We fork this all off from a child process so that we can somewhat cleanly make
         * use of SIGALRM to set a time limit.
         *
         * If callbacks is nonnull, execution is serial. Otherwise, we default to parallel.
         */

        r = conf_files_list_strv(&paths, NULL, NULL, CONF_FILES_EXECUTABLE|CONF_FILES_REGULAR|CONF_FILES_FILTER_MASKED, (const char* const*) directories);
        if (r < 0)
                return r;

        if (!callbacks) {
                pids = hashmap_new(NULL);
                if (!pids)
                        return log_oom();
        }

        /* Abort execution of this process after the timout. We simply rely on SIGALRM as
         * default action terminating the process, and turn on alarm(). */

        if (timeout != USEC_INFINITY)
                alarm(DIV_ROUND_UP(timeout, USEC_PER_SEC));

        STRV_FOREACH(e, envp)
                if (putenv(*e) < 0)
                        return log_error_errno(errno, "Failed to set environment variable: %m");

        STRV_FOREACH(path, paths) {
                _cleanup_free_ char *t = NULL;
                _cleanup_close_ int fd = -1;
#if 0 /// No "maybe uninitialized" warning in elogind
                pid_t pid;
#else
                pid_t pid = 0;
#endif // 0

                t = strdup(*path);
                if (!t)
                        return log_oom();

                if (callbacks) {
                        fd = open_serialization_fd(basename(*path));
                        if (fd < 0)
                                return log_error_errno(fd, "Failed to open serialization file: %m");
                }

                r = do_spawn(t, argv, fd, &pid);
                if (r <= 0)
                        continue;

                if (pids) {
                        r = hashmap_put(pids, PID_TO_PTR(pid), t);
                        if (r < 0)
                                return log_oom();
                        t = NULL;
                } else {
                        r = wait_for_terminate_and_check(t, pid, WAIT_LOG);
                        if (r < 0)
                                continue;

                        if (lseek(fd, 0, SEEK_SET) < 0)
                                return log_error_errno(errno, "Failed to seek on serialization fd: %m");

                        r = callbacks[STDOUT_GENERATE](fd, callback_args[STDOUT_GENERATE]);
                        fd = -1;
                        if (r < 0)
                                return log_error_errno(r, "Failed to process output from %s: %m", *path);
                }
        }

        if (callbacks) {
                r = callbacks[STDOUT_COLLECT](output_fd, callback_args[STDOUT_COLLECT]);
                if (r < 0)
                        return log_error_errno(r, "Callback two failed: %m");
        }

        while (!hashmap_isempty(pids)) {
                _cleanup_free_ char *t = NULL;
                pid_t pid;

                pid = PTR_TO_PID(hashmap_first_key(pids));
                assert(pid > 0);

                t = hashmap_remove(pids, PID_TO_PTR(pid));
                assert(t);

                (void) wait_for_terminate_and_check(t, pid, WAIT_LOG);
        }

        return 0;
}

int execute_directories(
                const char* const* directories,
                usec_t timeout,
                gather_stdout_callback_t const callbacks[_STDOUT_CONSUME_MAX],
                void* const callback_args[_STDOUT_CONSUME_MAX],
                char *argv[],
                char *envp[]) {

        char **dirs = (char**) directories;
        _cleanup_close_ int fd = -1;
        char *name;
        int r;

        assert(!strv_isempty(dirs));

        name = basename(dirs[0]);
        assert(!isempty(name));

        if (callbacks) {
                assert(callback_args);
                assert(callbacks[STDOUT_GENERATE]);
                assert(callbacks[STDOUT_COLLECT]);
                assert(callbacks[STDOUT_CONSUME]);

                fd = open_serialization_fd(name);
                if (fd < 0)
                        return log_error_errno(fd, "Failed to open serialization file: %m");
        }

        /* Executes all binaries in the directories serially or in parallel and waits for
         * them to finish. Optionally a timeout is applied. If a file with the same name
         * exists in more than one directory, the earliest one wins. */

        r = safe_fork("(sd-executor)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG|FORK_WAIT, NULL);
        if (r < 0)
                return r;
        if (r == 0) {
                r = do_execute(dirs, timeout, callbacks, callback_args, fd, argv, envp);
                _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
        }

        if (!callbacks)
                return 0;

        if (lseek(fd, 0, SEEK_SET) < 0)
                return log_error_errno(errno, "Failed to rewind serialization fd: %m");

        r = callbacks[STDOUT_CONSUME](fd, callback_args[STDOUT_CONSUME]);
        fd = -1;
        if (r < 0)
                return log_error_errno(r, "Failed to parse returned data: %m");
        return 0;
}

#if 0 /// UNNEEDED by elogind
static int gather_environment_generate(int fd, void *arg) {
        char ***env = arg, **x, **y;
        _cleanup_fclose_ FILE *f = NULL;
        _cleanup_strv_free_ char **new = NULL;
        int r;

        /* Read a series of VAR=value assignments from fd, use them to update the list of
         * variables in env. Also update the exported environment.
         *
         * fd is always consumed, even on error.
         */

        assert(env);

        f = fdopen(fd, "r");
        if (!f) {
                safe_close(fd);
                return -errno;
        }

        r = load_env_file_pairs(f, NULL, NULL, &new);
        if (r < 0)
                return r;

        STRV_FOREACH_PAIR(x, y, new) {
                char *p;

                if (!env_name_is_valid(*x)) {
                        log_warning("Invalid variable assignment \"%s=...\", ignoring.", *x);
                        continue;
                }

                p = strjoin(*x, "=", *y);
                if (!p)
                        return -ENOMEM;

                r = strv_env_replace(env, p);
                if (r < 0)
                        return r;

                if (setenv(*x, *y, true) < 0)
                        return -errno;
        }

        return r;
}

static int gather_environment_collect(int fd, void *arg) {
        char ***env = arg;
        _cleanup_fclose_ FILE *f = NULL;
        int r;

        /* Write out a series of env=cescape(VAR=value) assignments to fd. */

        assert(env);

        f = fdopen(fd, "w");
        if (!f) {
                safe_close(fd);
                return -errno;
        }

        r = serialize_environment(f, *env);
        if (r < 0)
                return r;

        if (ferror(f))
                return errno > 0 ? -errno : -EIO;

        return 0;
}

static int gather_environment_consume(int fd, void *arg) {
        char ***env = arg;
        _cleanup_fclose_ FILE *f = NULL;
        char line[LINE_MAX];
        int r = 0, k;

        /* Read a series of env=cescape(VAR=value) assignments from fd into env. */

        assert(env);

        f = fdopen(fd, "r");
        if (!f) {
                safe_close(fd);
                return -errno;
        }

        FOREACH_LINE(line, f, return -EIO) {
                truncate_nl(line);

                k = deserialize_environment(env, line);
                if (k < 0)
                        log_error_errno(k, "Invalid line \"%s\": %m", line);
                if (k < 0 && r == 0)
                        r = k;
        }

        return r;
}

const gather_stdout_callback_t gather_environment[] = {
        gather_environment_generate,
        gather_environment_collect,
        gather_environment_consume,
};
#endif // 0