1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6 #include <stdio.h>
7 #include <unistd.h>
8 #include <stdlib.h>
9 #include <string.h>
10 #include <errno.h>
11 #include <fcntl.h>
12 #include <signal.h>
13 #include <linux/falloc.h>
14 #include <sys/ioctl.h>
15 #include <sys/mount.h>
16 #include <sys/socket.h>
17 #include <sys/stat.h>
18 #include <sys/sysmacros.h>
19 #include <sys/un.h>
20 #include <sys/types.h>
21 #include <sys/eventfd.h>
22 #include <poll.h>
23 #include <os.h>
24
25 static void copy_stat(struct uml_stat *dst, const struct stat64 *src)
26 {
27 *dst = ((struct uml_stat) {
28 .ust_dev = src->st_dev, /* device */
29 .ust_ino = src->st_ino, /* inode */
30 .ust_mode = src->st_mode, /* protection */
31 .ust_nlink = src->st_nlink, /* number of hard links */
32 .ust_uid = src->st_uid, /* user ID of owner */
33 .ust_gid = src->st_gid, /* group ID of owner */
34 .ust_size = src->st_size, /* total size, in bytes */
35 .ust_blksize = src->st_blksize, /* blocksize for filesys I/O */
36 .ust_blocks = src->st_blocks, /* number of blocks allocated */
37 .ust_atime = src->st_atime, /* time of last access */
38 .ust_mtime = src->st_mtime, /* time of last modification */
39 .ust_ctime = src->st_ctime, /* time of last change */
40 });
41 }
42
43 int os_stat_fd(const int fd, struct uml_stat *ubuf)
44 {
45 struct stat64 sbuf;
46 int err;
47
48 CATCH_EINTR(err = fstat64(fd, &sbuf));
49 if (err < 0)
50 return -errno;
51
52 if (ubuf != NULL)
53 copy_stat(ubuf, &sbuf);
54 return err;
55 }
56
57 int os_stat_file(const char *file_name, struct uml_stat *ubuf)
58 {
59 struct stat64 sbuf;
60 int err;
61
62 CATCH_EINTR(err = stat64(file_name, &sbuf));
63 if (err < 0)
64 return -errno;
65
66 if (ubuf != NULL)
67 copy_stat(ubuf, &sbuf);
68 return err;
69 }
70
71 int os_access(const char *file, int mode)
72 {
73 int amode, err;
74
75 amode = (mode & OS_ACC_R_OK ? R_OK : 0) |
76 (mode & OS_ACC_W_OK ? W_OK : 0) |
77 (mode & OS_ACC_X_OK ? X_OK : 0) |
78 (mode & OS_ACC_F_OK ? F_OK : 0);
79
80 err = access(file, amode);
81 if (err < 0)
82 return -errno;
83
84 return 0;
85 }
86
87 /* FIXME? required only by hostaudio (because it passes ioctls verbatim) */
88 int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
89 {
90 int err;
91
92 err = ioctl(fd, cmd, arg);
93 if (err < 0)
94 return -errno;
95
96 return err;
97 }
98
99 /* FIXME: ensure namebuf in os_get_if_name is big enough */
100 int os_get_ifname(int fd, char* namebuf)
101 {
102 if (ioctl(fd, SIOCGIFNAME, namebuf) < 0)
103 return -errno;
104
105 return 0;
106 }
107
108 int os_set_slip(int fd)
109 {
110 int disc, sencap;
111
112 disc = N_SLIP;
113 if (ioctl(fd, TIOCSETD, &disc) < 0)
114 return -errno;
115
116 sencap = 0;
117 if (ioctl(fd, SIOCSIFENCAP, &sencap) < 0)
118 return -errno;
119
120 return 0;
121 }
122
123 int os_mode_fd(int fd, int mode)
124 {
125 int err;
126
127 CATCH_EINTR(err = fchmod(fd, mode));
128 if (err < 0)
129 return -errno;
130
131 return 0;
132 }
133
134 int os_file_type(char *file)
135 {
136 struct uml_stat buf;
137 int err;
138
139 err = os_stat_file(file, &buf);
140 if (err < 0)
141 return err;
142
143 if (S_ISDIR(buf.ust_mode))
144 return OS_TYPE_DIR;
145 else if (S_ISLNK(buf.ust_mode))
146 return OS_TYPE_SYMLINK;
147 else if (S_ISCHR(buf.ust_mode))
148 return OS_TYPE_CHARDEV;
149 else if (S_ISBLK(buf.ust_mode))
150 return OS_TYPE_BLOCKDEV;
151 else if (S_ISFIFO(buf.ust_mode))
152 return OS_TYPE_FIFO;
153 else if (S_ISSOCK(buf.ust_mode))
154 return OS_TYPE_SOCK;
155 else return OS_TYPE_FILE;
156 }
157
158 int os_file_mode(const char *file, struct openflags *mode_out)
159 {
160 int err;
161
162 *mode_out = OPENFLAGS();
163
164 err = access(file, W_OK);
165 if (err && (errno != EACCES))
166 return -errno;
167 else if (!err)
168 *mode_out = of_write(*mode_out);
169
170 err = access(file, R_OK);
171 if (err && (errno != EACCES))
172 return -errno;
173 else if (!err)
174 *mode_out = of_read(*mode_out);
175
176 return err;
177 }
178
179 int os_open_file(const char *file, struct openflags flags, int mode)
180 {
181 int fd, err, f = 0;
182
183 if (flags.r && flags.w)
184 f = O_RDWR;
185 else if (flags.r)
186 f = O_RDONLY;
187 else if (flags.w)
188 f = O_WRONLY;
189 else f = 0;
190
191 if (flags.s)
192 f |= O_SYNC;
193 if (flags.c)
194 f |= O_CREAT;
195 if (flags.t)
196 f |= O_TRUNC;
197 if (flags.e)
198 f |= O_EXCL;
199 if (flags.a)
200 f |= O_APPEND;
201
202 fd = open64(file, f, mode);
203 if (fd < 0)
204 return -errno;
205
206 if (flags.cl && fcntl(fd, F_SETFD, 1)) {
207 err = -errno;
208 close(fd);
209 return err;
210 }
211
212 return fd;
213 }
214
215 int os_connect_socket(const char *name)
216 {
217 struct sockaddr_un sock;
218 int fd, err;
219
220 sock.sun_family = AF_UNIX;
221 snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
222
223 fd = socket(AF_UNIX, SOCK_STREAM, 0);
224 if (fd < 0) {
225 err = -errno;
226 goto out;
227 }
228
229 err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
230 if (err) {
231 err = -errno;
232 goto out_close;
233 }
234
235 return fd;
236
237 out_close:
238 close(fd);
239 out:
240 return err;
241 }
242
243 void os_close_file(int fd)
244 {
245 close(fd);
246 }
247 int os_fsync_file(int fd)
248 {
249 if (fsync(fd) < 0)
250 return -errno;
251 return 0;
252 }
253
254 int os_seek_file(int fd, unsigned long long offset)
255 {
256 unsigned long long actual;
257
258 actual = lseek64(fd, offset, SEEK_SET);
259 if (actual != offset)
260 return -errno;
261 return 0;
262 }
263
264 int os_read_file(int fd, void *buf, int len)
265 {
266 int n = read(fd, buf, len);
267
268 if (n < 0)
269 return -errno;
270 return n;
271 }
272
273 int os_pread_file(int fd, void *buf, int len, unsigned long long offset)
274 {
275 int n = pread(fd, buf, len, offset);
276
277 if (n < 0)
278 return -errno;
279 return n;
280 }
281
282 int os_write_file(int fd, const void *buf, int len)
283 {
284 int n = write(fd, (void *) buf, len);
285
286 if (n < 0)
287 return -errno;
288 return n;
289 }
290
291 int os_sync_file(int fd)
292 {
293 int n = fdatasync(fd);
294
295 if (n < 0)
296 return -errno;
297 return n;
298 }
299
300 int os_pwrite_file(int fd, const void *buf, int len, unsigned long long offset)
301 {
302 int n = pwrite(fd, (void *) buf, len, offset);
303
304 if (n < 0)
305 return -errno;
306 return n;
307 }
308
309
310 int os_file_size(const char *file, unsigned long long *size_out)
311 {
312 struct uml_stat buf;
313 int err;
314
315 err = os_stat_file(file, &buf);
316 if (err < 0) {
317 printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
318 -err);
319 return err;
320 }
321
322 if (S_ISBLK(buf.ust_mode)) {
323 int fd;
324 long blocks;
325
326 fd = open(file, O_RDONLY, 0);
327 if (fd < 0) {
328 err = -errno;
329 printk(UM_KERN_ERR "Couldn't open \"%s\", "
330 "errno = %d\n", file, errno);
331 return err;
332 }
333 if (ioctl(fd, BLKGETSIZE, &blocks) < 0) {
334 err = -errno;
335 printk(UM_KERN_ERR "Couldn't get the block size of "
336 "\"%s\", errno = %d\n", file, errno);
337 close(fd);
338 return err;
339 }
340 *size_out = ((long long) blocks) * 512;
341 close(fd);
342 }
343 else *size_out = buf.ust_size;
344
345 return 0;
346 }
347
348 int os_file_modtime(const char *file, long long *modtime)
349 {
350 struct uml_stat buf;
351 int err;
352
353 err = os_stat_file(file, &buf);
354 if (err < 0) {
355 printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
356 -err);
357 return err;
358 }
359
360 *modtime = buf.ust_mtime;
361 return 0;
362 }
363
364 int os_set_exec_close(int fd)
365 {
366 int err;
367
368 CATCH_EINTR(err = fcntl(fd, F_SETFD, FD_CLOEXEC));
369
370 if (err < 0)
371 return -errno;
372 return err;
373 }
374
375 int os_pipe(int *fds, int stream, int close_on_exec)
376 {
377 int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
378
379 err = socketpair(AF_UNIX, type, 0, fds);
380 if (err < 0)
381 return -errno;
382
383 if (!close_on_exec)
384 return 0;
385
386 err = os_set_exec_close(fds[0]);
387 if (err < 0)
388 goto error;
389
390 err = os_set_exec_close(fds[1]);
391 if (err < 0)
392 goto error;
393
394 return 0;
395
396 error:
397 printk(UM_KERN_ERR "os_pipe : Setting FD_CLOEXEC failed, err = %d\n",
398 -err);
399 close(fds[1]);
400 close(fds[0]);
401 return err;
402 }
403
404 int os_set_fd_async(int fd)
405 {
406 int err, flags;
407
408 flags = fcntl(fd, F_GETFL);
409 if (flags < 0)
410 return -errno;
411
412 flags |= O_ASYNC | O_NONBLOCK;
413 if (fcntl(fd, F_SETFL, flags) < 0) {
414 err = -errno;
415 printk(UM_KERN_ERR "os_set_fd_async : failed to set O_ASYNC "
416 "and O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
417 return err;
418 }
419
420 if ((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
421 (fcntl(fd, F_SETOWN, os_getpid()) < 0)) {
422 err = -errno;
423 printk(UM_KERN_ERR "os_set_fd_async : Failed to fcntl F_SETOWN "
424 "(or F_SETSIG) fd %d, errno = %d\n", fd, errno);
425 return err;
426 }
427
428 return 0;
429 }
430
431 int os_clear_fd_async(int fd)
432 {
433 int flags;
434
435 flags = fcntl(fd, F_GETFL);
436 if (flags < 0)
437 return -errno;
438
439 flags &= ~(O_ASYNC | O_NONBLOCK);
440 if (fcntl(fd, F_SETFL, flags) < 0)
441 return -errno;
442 return 0;
443 }
444
445 int os_set_fd_block(int fd, int blocking)
446 {
447 int flags;
448
449 flags = fcntl(fd, F_GETFL);
450 if (flags < 0)
451 return -errno;
452
453 if (blocking)
454 flags &= ~O_NONBLOCK;
455 else
456 flags |= O_NONBLOCK;
457
458 if (fcntl(fd, F_SETFL, flags) < 0)
459 return -errno;
460
461 return 0;
462 }
463
464 int os_accept_connection(int fd)
465 {
466 int new;
467
468 new = accept(fd, NULL, 0);
469 if (new < 0)
470 return -errno;
471 return new;
472 }
473
474 #ifndef SHUT_RD
475 #define SHUT_RD 0
476 #endif
477
478 #ifndef SHUT_WR
479 #define SHUT_WR 1
480 #endif
481
482 #ifndef SHUT_RDWR
483 #define SHUT_RDWR 2
484 #endif
485
486 int os_shutdown_socket(int fd, int r, int w)
487 {
488 int what, err;
489
490 if (r && w)
491 what = SHUT_RDWR;
492 else if (r)
493 what = SHUT_RD;
494 else if (w)
495 what = SHUT_WR;
496 else
497 return -EINVAL;
498
499 err = shutdown(fd, what);
500 if (err < 0)
501 return -errno;
502 return 0;
503 }
504
505 int os_rcv_fd(int fd, int *helper_pid_out)
506 {
507 int new, n;
508 char buf[CMSG_SPACE(sizeof(new))];
509 struct msghdr msg;
510 struct cmsghdr *cmsg;
511 struct iovec iov;
512
513 msg.msg_name = NULL;
514 msg.msg_namelen = 0;
515 iov = ((struct iovec) { .iov_base = helper_pid_out,
516 .iov_len = sizeof(*helper_pid_out) });
517 msg.msg_iov = &iov;
518 msg.msg_iovlen = 1;
519 msg.msg_control = buf;
520 msg.msg_controllen = sizeof(buf);
521 msg.msg_flags = 0;
522
523 n = recvmsg(fd, &msg, 0);
524 if (n < 0)
525 return -errno;
526 else if (n != iov.iov_len)
527 *helper_pid_out = -1;
528
529 cmsg = CMSG_FIRSTHDR(&msg);
530 if (cmsg == NULL) {
531 printk(UM_KERN_ERR "rcv_fd didn't receive anything, "
532 "error = %d\n", errno);
533 return -1;
534 }
535 if ((cmsg->cmsg_level != SOL_SOCKET) ||
536 (cmsg->cmsg_type != SCM_RIGHTS)) {
537 printk(UM_KERN_ERR "rcv_fd didn't receive a descriptor\n");
538 return -1;
539 }
540
541 new = ((int *) CMSG_DATA(cmsg))[0];
542 return new;
543 }
544
545 int os_create_unix_socket(const char *file, int len, int close_on_exec)
546 {
547 struct sockaddr_un addr;
548 int sock, err;
549
550 sock = socket(PF_UNIX, SOCK_DGRAM, 0);
551 if (sock < 0)
552 return -errno;
553
554 if (close_on_exec) {
555 err = os_set_exec_close(sock);
556 if (err < 0)
557 printk(UM_KERN_ERR "create_unix_socket : "
558 "close_on_exec failed, err = %d", -err);
559 }
560
561 addr.sun_family = AF_UNIX;
562
563 snprintf(addr.sun_path, len, "%s", file);
564
565 err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
566 if (err < 0)
567 return -errno;
568
569 return sock;
570 }
571
572 void os_flush_stdout(void)
573 {
574 fflush(stdout);
575 }
576
577 int os_lock_file(int fd, int excl)
578 {
579 int type = excl ? F_WRLCK : F_RDLCK;
580 struct flock lock = ((struct flock) { .l_type = type,
581 .l_whence = SEEK_SET,
582 .l_start = 0,
583 .l_len = 0 } );
584 int err, save;
585
586 err = fcntl(fd, F_SETLK, &lock);
587 if (!err)
588 goto out;
589
590 save = -errno;
591 err = fcntl(fd, F_GETLK, &lock);
592 if (err) {
593 err = -errno;
594 goto out;
595 }
596
597 printk(UM_KERN_ERR "F_SETLK failed, file already locked by pid %d\n",
598 lock.l_pid);
599 err = save;
600 out:
601 return err;
602 }
603
604 unsigned os_major(unsigned long long dev)
605 {
606 return major(dev);
607 }
608
609 unsigned os_minor(unsigned long long dev)
610 {
611 return minor(dev);
612 }
613
614 unsigned long long os_makedev(unsigned major, unsigned minor)
615 {
616 return makedev(major, minor);
617 }
618
619 int os_falloc_punch(int fd, unsigned long long offset, int len)
620 {
621 int n = fallocate(fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, offset, len);
622
623 if (n < 0)
624 return -errno;
625 return n;
626 }
627
628 int os_eventfd(unsigned int initval, int flags)
629 {
630 int fd = eventfd(initval, flags);
631
632 if (fd < 0)
633 return -errno;
634 return fd;
635 }
636
637 int os_sendmsg_fds(int fd, const void *buf, unsigned int len, const int *fds,
638 unsigned int fds_num)
639 {
640 struct iovec iov = {
641 .iov_base = (void *) buf,
642 .iov_len = len,
643 };
644 union {
645 char control[CMSG_SPACE(sizeof(*fds) * OS_SENDMSG_MAX_FDS)];
646 struct cmsghdr align;
647 } u;
648 unsigned int fds_size = sizeof(*fds) * fds_num;
649 struct msghdr msg = {
650 .msg_iov = &iov,
651 .msg_iovlen = 1,
652 .msg_control = u.control,
653 .msg_controllen = CMSG_SPACE(fds_size),
654 };
655 struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
656 int err;
657
658 if (fds_num > OS_SENDMSG_MAX_FDS)
659 return -EINVAL;
660 memset(u.control, 0, sizeof(u.control));
661 cmsg->cmsg_level = SOL_SOCKET;
662 cmsg->cmsg_type = SCM_RIGHTS;
663 cmsg->cmsg_len = CMSG_LEN(fds_size);
664 memcpy(CMSG_DATA(cmsg), fds, fds_size);
665 err = sendmsg(fd, &msg, 0);
666
667 if (err < 0)
668 return -errno;
669 return err;
670 }
671
672 int os_poll(unsigned int n, const int *fds)
673 {
674 /* currently need 2 FDs at most so avoid dynamic allocation */
675 struct pollfd pollfds[2] = {};
676 unsigned int i;
677 int ret;
678
679 if (n > ARRAY_SIZE(pollfds))
680 return -EINVAL;
681
682 for (i = 0; i < n; i++) {
683 pollfds[i].fd = fds[i];
684 pollfds[i].events = POLLIN;
685 }
686
687 ret = poll(pollfds, n, -1);
688 if (ret < 0)
689 return -errno;
690
691 /* Return the index of the available FD */
692 for (i = 0; i < n; i++) {
693 if (pollfds[i].revents)
694 return i;
695 }
696
697 return -EIO;
698 }
699
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.