1 /*-
2 * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/lib/libc/gen/posix_spawn.c,v 1.6 2008/10/23 15:32:06 rdivacky Exp $
27 */
28
29 #include "namespace.h"
30 #include <sys/queue.h>
31
32 #include <errno.h>
33 #include <fcntl.h>
34 #include <sched.h>
35 #include <spawn.h>
36 #include <signal.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <unistd.h>
40 #include "un-namespace.h"
41 #include "libc_private.h"
42
43 extern char **environ;
44
45 struct __posix_spawnattr {
46 short sa_flags;
47 pid_t sa_pgroup;
48 struct sched_param sa_schedparam;
49 int sa_schedpolicy;
50 sigset_t sa_sigdefault;
51 sigset_t sa_sigmask;
52 };
53
54 struct __posix_spawn_file_actions {
55 STAILQ_HEAD(, __posix_spawn_file_actions_entry) fa_list;
56 };
57
58 typedef struct __posix_spawn_file_actions_entry {
59 STAILQ_ENTRY(__posix_spawn_file_actions_entry) fae_list;
60 enum { FAE_OPEN, FAE_DUP2, FAE_CLOSE } fae_action;
61
62 int fae_fildes;
63 union {
64 struct {
65 char *path;
66 #define fae_path fae_data.open.path
67 int oflag;
68 #define fae_oflag fae_data.open.oflag
69 mode_t mode;
70 #define fae_mode fae_data.open.mode
71 } open;
72 struct {
73 int newfildes;
74 #define fae_newfildes fae_data.dup2.newfildes
75 } dup2;
76 } fae_data;
77 } posix_spawn_file_actions_entry_t;
78
79 /*
80 * Spawn routines
81 */
82
83 static int
process_spawnattr(const posix_spawnattr_t sa)84 process_spawnattr(const posix_spawnattr_t sa)
85 {
86 struct sigaction sigact = { .sa_flags = 0, .sa_handler = SIG_DFL };
87 int i;
88
89 /*
90 * POSIX doesn't really describe in which order everything
91 * should be set. We'll just set them in the order in which they
92 * are mentioned.
93 */
94
95 /* Set process group */
96 if (sa->sa_flags & POSIX_SPAWN_SETPGROUP) {
97 if (setpgid(0, sa->sa_pgroup) != 0)
98 return (errno);
99 }
100
101 /* Set scheduler policy */
102 if (sa->sa_flags & POSIX_SPAWN_SETSCHEDULER) {
103 if (sched_setscheduler(0, sa->sa_schedpolicy,
104 &sa->sa_schedparam) != 0)
105 return (errno);
106 } else if (sa->sa_flags & POSIX_SPAWN_SETSCHEDPARAM) {
107 if (sched_setparam(0, &sa->sa_schedparam) != 0)
108 return (errno);
109 }
110
111 /* Reset user ID's */
112 if (sa->sa_flags & POSIX_SPAWN_RESETIDS) {
113 if (setegid(getgid()) != 0)
114 return (errno);
115 if (seteuid(getuid()) != 0)
116 return (errno);
117 }
118
119 /* Set signal masks/defaults */
120 if (sa->sa_flags & POSIX_SPAWN_SETSIGMASK) {
121 _sigprocmask(SIG_SETMASK, &sa->sa_sigmask, NULL);
122 }
123
124 if (sa->sa_flags & POSIX_SPAWN_SETSIGDEF) {
125 for (i = 1; i <= _SIG_MAXSIG; i++) {
126 if (sigismember(&sa->sa_sigdefault, i))
127 if (_sigaction(i, &sigact, NULL) != 0)
128 return (errno);
129 }
130 }
131
132 return (0);
133 }
134
135 static int
process_file_actions_entry(posix_spawn_file_actions_entry_t * fae)136 process_file_actions_entry(posix_spawn_file_actions_entry_t *fae)
137 {
138 int fd;
139
140 switch (fae->fae_action) {
141 case FAE_OPEN:
142 /* Perform an open(), make it use the right fd */
143 fd = _open(fae->fae_path, fae->fae_oflag, fae->fae_mode);
144 if (fd < 0)
145 return (errno);
146 if (fd != fae->fae_fildes) {
147 if (_dup2(fd, fae->fae_fildes) == -1)
148 return (errno);
149 if (_close(fd) != 0) {
150 if (errno == EBADF)
151 return (EBADF);
152 }
153 }
154 if (_fcntl(fae->fae_fildes, F_SETFD, 0) == -1)
155 return (errno);
156 break;
157 case FAE_DUP2:
158 /* Perform a dup2() */
159 if (_dup2(fae->fae_fildes, fae->fae_newfildes) == -1)
160 return (errno);
161 if (_fcntl(fae->fae_newfildes, F_SETFD, 0) == -1)
162 return (errno);
163 break;
164 case FAE_CLOSE:
165 /* Perform a close() */
166 if (_close(fae->fae_fildes) != 0) {
167 if (errno == EBADF)
168 return (EBADF);
169 }
170 break;
171 }
172 return (0);
173 }
174
175 static int
process_file_actions(const posix_spawn_file_actions_t fa)176 process_file_actions(const posix_spawn_file_actions_t fa)
177 {
178 posix_spawn_file_actions_entry_t *fae;
179 int error;
180
181 /* Replay all file descriptor modifications */
182 STAILQ_FOREACH(fae, &fa->fa_list, fae_list) {
183 error = process_file_actions_entry(fae);
184 if (error)
185 return (error);
186 }
187 return (0);
188 }
189
190 static int
do_posix_spawn(pid_t * pid,const char * path,const posix_spawn_file_actions_t * fa,const posix_spawnattr_t * sa,char * const argv[],char * const envp[],int use_env_path)191 do_posix_spawn(pid_t *pid, const char *path,
192 const posix_spawn_file_actions_t *fa,
193 const posix_spawnattr_t *sa, char * const argv[],
194 char * const envp[], int use_env_path)
195 {
196 pid_t p;
197 volatile int error = 0;
198
199 p = vfork();
200 switch (p) {
201 case -1:
202 return (errno);
203 case 0:
204 if (sa != NULL) {
205 error = process_spawnattr(*sa);
206 if (error)
207 _exit(127);
208 }
209 if (fa != NULL) {
210 error = process_file_actions(*fa);
211 if (error)
212 _exit(127);
213 }
214 if (use_env_path)
215 _execvpe(path, argv, envp != NULL ? envp : environ);
216 else
217 _execve(path, argv, envp != NULL ? envp : environ);
218 error = errno;
219 _exit(127);
220 default:
221 if (pid != NULL)
222 *pid = p;
223 return (error);
224 }
225 }
226
227 int
posix_spawn(pid_t * __restrict pid,const char * __restrict path,const posix_spawn_file_actions_t * fa,const posix_spawnattr_t * __restrict sa,char * const argv[__restrict_arr],char * const envp[__restrict_arr])228 posix_spawn(pid_t * __restrict pid, const char * __restrict path,
229 const posix_spawn_file_actions_t *fa,
230 const posix_spawnattr_t * __restrict sa, char * const argv[__restrict_arr],
231 char * const envp[__restrict_arr])
232 {
233 return do_posix_spawn(pid, path, fa, sa, argv, envp, 0);
234 }
235
236 int
posix_spawnp(pid_t * __restrict pid,const char * __restrict path,const posix_spawn_file_actions_t * fa,const posix_spawnattr_t * __restrict sa,char * const argv[__restrict_arr],char * const envp[__restrict_arr])237 posix_spawnp(pid_t * __restrict pid, const char * __restrict path,
238 const posix_spawn_file_actions_t *fa,
239 const posix_spawnattr_t * __restrict sa, char * const argv[__restrict_arr],
240 char * const envp[__restrict_arr])
241 {
242 return do_posix_spawn(pid, path, fa, sa, argv, envp, 1);
243 }
244
245 /*
246 * File descriptor actions
247 */
248
249 int
posix_spawn_file_actions_init(posix_spawn_file_actions_t * ret)250 posix_spawn_file_actions_init(posix_spawn_file_actions_t *ret)
251 {
252 posix_spawn_file_actions_t fa;
253
254 fa = malloc(sizeof(struct __posix_spawn_file_actions));
255 if (fa == NULL)
256 return (-1);
257
258 STAILQ_INIT(&fa->fa_list);
259 *ret = fa;
260 return (0);
261 }
262
263 int
posix_spawn_file_actions_destroy(posix_spawn_file_actions_t * fa)264 posix_spawn_file_actions_destroy(posix_spawn_file_actions_t *fa)
265 {
266 posix_spawn_file_actions_entry_t *fae;
267
268 while ((fae = STAILQ_FIRST(&(*fa)->fa_list)) != NULL) {
269 /* Remove file action entry from the queue */
270 STAILQ_REMOVE_HEAD(&(*fa)->fa_list, fae_list);
271
272 /* Deallocate file action entry */
273 if (fae->fae_action == FAE_OPEN)
274 free(fae->fae_path);
275 free(fae);
276 }
277
278 free(*fa);
279 return (0);
280 }
281
282 int
posix_spawn_file_actions_addopen(posix_spawn_file_actions_t * __restrict fa,int fildes,const char * __restrict path,int oflag,mode_t mode)283 posix_spawn_file_actions_addopen(posix_spawn_file_actions_t * __restrict fa,
284 int fildes, const char * __restrict path,
285 int oflag, mode_t mode)
286 {
287 posix_spawn_file_actions_entry_t *fae;
288 int error;
289
290 if (fildes < 0)
291 return (EBADF);
292
293 /* Allocate object */
294 fae = malloc(sizeof(posix_spawn_file_actions_entry_t));
295 if (fae == NULL)
296 return (errno);
297
298 /* Set values and store in queue */
299 fae->fae_action = FAE_OPEN;
300 fae->fae_path = strdup(path);
301 if (fae->fae_path == NULL) {
302 error = errno;
303 free(fae);
304 return (error);
305 }
306 fae->fae_fildes = fildes;
307 fae->fae_oflag = oflag;
308 fae->fae_mode = mode;
309
310 STAILQ_INSERT_TAIL(&(*fa)->fa_list, fae, fae_list);
311 return (0);
312 }
313
314 int
posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t * fa,int fildes,int newfildes)315 posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *fa,
316 int fildes, int newfildes)
317 {
318 posix_spawn_file_actions_entry_t *fae;
319
320 if (fildes < 0 || newfildes < 0)
321 return (EBADF);
322
323 /* Allocate object */
324 fae = malloc(sizeof(posix_spawn_file_actions_entry_t));
325 if (fae == NULL)
326 return (errno);
327
328 /* Set values and store in queue */
329 fae->fae_action = FAE_DUP2;
330 fae->fae_fildes = fildes;
331 fae->fae_newfildes = newfildes;
332
333 STAILQ_INSERT_TAIL(&(*fa)->fa_list, fae, fae_list);
334 return (0);
335 }
336
337 int
posix_spawn_file_actions_addclose(posix_spawn_file_actions_t * fa,int fildes)338 posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *fa,
339 int fildes)
340 {
341 posix_spawn_file_actions_entry_t *fae;
342
343 if (fildes < 0)
344 return (EBADF);
345
346 /* Allocate object */
347 fae = malloc(sizeof(posix_spawn_file_actions_entry_t));
348 if (fae == NULL)
349 return (errno);
350
351 /* Set values and store in queue */
352 fae->fae_action = FAE_CLOSE;
353 fae->fae_fildes = fildes;
354
355 STAILQ_INSERT_TAIL(&(*fa)->fa_list, fae, fae_list);
356 return (0);
357 }
358
359 /*
360 * Spawn attributes
361 */
362
363 int
posix_spawnattr_init(posix_spawnattr_t * ret)364 posix_spawnattr_init(posix_spawnattr_t *ret)
365 {
366 posix_spawnattr_t sa;
367
368 sa = calloc(1, sizeof(struct __posix_spawnattr));
369 if (sa == NULL)
370 return (errno);
371
372 /* Set defaults as specified by POSIX, cleared above */
373 *ret = sa;
374 return (0);
375 }
376
377 int
posix_spawnattr_destroy(posix_spawnattr_t * sa)378 posix_spawnattr_destroy(posix_spawnattr_t *sa)
379 {
380 free(*sa);
381 return (0);
382 }
383
384 int
posix_spawnattr_getflags(const posix_spawnattr_t * __restrict sa,short * __restrict flags)385 posix_spawnattr_getflags(const posix_spawnattr_t * __restrict sa,
386 short * __restrict flags)
387 {
388 *flags = (*sa)->sa_flags;
389 return (0);
390 }
391
392 int
posix_spawnattr_getpgroup(const posix_spawnattr_t * __restrict sa,pid_t * __restrict pgroup)393 posix_spawnattr_getpgroup(const posix_spawnattr_t * __restrict sa,
394 pid_t * __restrict pgroup)
395 {
396 *pgroup = (*sa)->sa_pgroup;
397 return (0);
398 }
399
400 int
posix_spawnattr_getschedparam(const posix_spawnattr_t * __restrict sa,struct sched_param * __restrict schedparam)401 posix_spawnattr_getschedparam(const posix_spawnattr_t * __restrict sa,
402 struct sched_param * __restrict schedparam)
403 {
404 *schedparam = (*sa)->sa_schedparam;
405 return (0);
406 }
407
408 int
posix_spawnattr_getschedpolicy(const posix_spawnattr_t * __restrict sa,int * __restrict schedpolicy)409 posix_spawnattr_getschedpolicy(const posix_spawnattr_t * __restrict sa,
410 int * __restrict schedpolicy)
411 {
412 *schedpolicy = (*sa)->sa_schedpolicy;
413 return (0);
414 }
415
416 int
posix_spawnattr_getsigdefault(const posix_spawnattr_t * __restrict sa,sigset_t * __restrict sigdefault)417 posix_spawnattr_getsigdefault(const posix_spawnattr_t * __restrict sa,
418 sigset_t * __restrict sigdefault)
419 {
420 *sigdefault = (*sa)->sa_sigdefault;
421 return (0);
422 }
423
424 int
posix_spawnattr_getsigmask(const posix_spawnattr_t * __restrict sa,sigset_t * __restrict sigmask)425 posix_spawnattr_getsigmask(const posix_spawnattr_t * __restrict sa,
426 sigset_t * __restrict sigmask)
427 {
428 *sigmask = (*sa)->sa_sigmask;
429 return (0);
430 }
431
432 int
posix_spawnattr_setflags(posix_spawnattr_t * sa,short flags)433 posix_spawnattr_setflags(posix_spawnattr_t *sa, short flags)
434 {
435 (*sa)->sa_flags = flags;
436 return (0);
437 }
438
439 int
posix_spawnattr_setpgroup(posix_spawnattr_t * sa,pid_t pgroup)440 posix_spawnattr_setpgroup(posix_spawnattr_t *sa, pid_t pgroup)
441 {
442 (*sa)->sa_pgroup = pgroup;
443 return (0);
444 }
445
446 int
posix_spawnattr_setschedparam(posix_spawnattr_t * __restrict sa,const struct sched_param * __restrict schedparam)447 posix_spawnattr_setschedparam(posix_spawnattr_t * __restrict sa,
448 const struct sched_param * __restrict schedparam)
449 {
450 (*sa)->sa_schedparam = *schedparam;
451 return (0);
452 }
453
454 int
posix_spawnattr_setschedpolicy(posix_spawnattr_t * sa,int schedpolicy)455 posix_spawnattr_setschedpolicy(posix_spawnattr_t *sa, int schedpolicy)
456 {
457 (*sa)->sa_schedpolicy = schedpolicy;
458 return (0);
459 }
460
461 int
posix_spawnattr_setsigdefault(posix_spawnattr_t * __restrict sa,const sigset_t * __restrict sigdefault)462 posix_spawnattr_setsigdefault(posix_spawnattr_t * __restrict sa,
463 const sigset_t * __restrict sigdefault)
464 {
465 (*sa)->sa_sigdefault = *sigdefault;
466 return (0);
467 }
468
469 int
posix_spawnattr_setsigmask(posix_spawnattr_t * __restrict sa,const sigset_t * __restrict sigmask)470 posix_spawnattr_setsigmask(posix_spawnattr_t * __restrict sa,
471 const sigset_t * __restrict sigmask)
472 {
473 (*sa)->sa_sigmask = *sigmask;
474 return (0);
475 }
476