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/mman.h>
21 #include <sys/types.h>
22 #include <sys/eventfd.h>
23 #include <poll.h>
24 #include <os.h>
25
26 static void copy_stat(struct uml_stat *dst, const struct stat64 *src)
27 {
28 *dst = ((struct uml_stat) {
29 .ust_dev = src->st_dev, /* device */
30 .ust_ino = src->st_ino, /* inode */
31 .ust_mode = src->st_mode, /* protection */
32 .ust_nlink = src->st_nlink, /* number of hard links */
33 .ust_uid = src->st_uid, /* user ID of owner */
34 .ust_gid = src->st_gid, /* group ID of owner */
35 .ust_size = src->st_size, /* total size, in bytes */
36 .ust_blksize = src->st_blksize, /* blocksize for filesys I/O */
37 .ust_blocks = src->st_blocks, /* number of blocks allocated */
38 .ust_atime = src->st_atime, /* time of last access */
39 .ust_mtime = src->st_mtime, /* time of last modification */
40 .ust_ctime = src->st_ctime, /* time of last change */
41 });
42 }
43
44 int os_stat_fd(const int fd, struct uml_stat *ubuf)
45 {
46 struct stat64 sbuf;
47 int err;
48
49 CATCH_EINTR(err = fstat64(fd, &sbuf));
50 if (err < 0)
51 return -errno;
52
53 if (ubuf != NULL)
54 copy_stat(ubuf, &sbuf);
55 return err;
56 }
57
58 int os_stat_file(const char *file_name, struct uml_stat *ubuf)
59 {
60 struct stat64 sbuf;
61 int err;
62
63 CATCH_EINTR(err = stat64(file_name, &sbuf));
64 if (err < 0)
65 return -errno;
66
67 if (ubuf != NULL)
68 copy_stat(ubuf, &sbuf);
69 return err;
70 }
71
72 int os_access(const char *file, int mode)
73 {
74 int amode, err;
75
76 amode = (mode & OS_ACC_R_OK ? R_OK : 0) |
77 (mode & OS_ACC_W_OK ? W_OK : 0) |
78 (mode & OS_ACC_X_OK ? X_OK : 0) |
79 (mode & OS_ACC_F_OK ? F_OK : 0);
80
81 err = access(file, amode);
82 if (err < 0)
83 return -errno;
84
85 return 0;
86 }
87
88 /* FIXME? required only by hostaudio (because it passes ioctls verbatim) */
89 int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
90 {
91 int err;
92
93 err = ioctl(fd, cmd, arg);
94 if (err < 0)
95 return -errno;
96
97 return err;
98 }
99
100 /* FIXME: ensure namebuf in os_get_if_name is big enough */
101 int os_get_ifname(int fd, char* namebuf)
102 {
103 if (ioctl(fd, SIOCGIFNAME, namebuf) < 0)
104 return -errno;
105
106 return 0;
107 }
108
109 int os_set_slip(int fd)
110 {
111 int disc, sencap;
112
113 disc = N_SLIP;
114 if (ioctl(fd, TIOCSETD, &disc) < 0)
115 return -errno;
116
117 sencap = 0;
118 if (ioctl(fd, SIOCSIFENCAP, &sencap) < 0)
119 return -errno;
120
121 return 0;
122 }
123
124 int os_mode_fd(int fd, int mode)
125 {
126 int err;
127
128 CATCH_EINTR(err = fchmod(fd, mode));
129 if (err < 0)
130 return -errno;
131
132 return 0;
133 }
134
135 int os_file_type(char *file)
136 {
137 struct uml_stat buf;
138 int err;
139
140 err = os_stat_file(file, &buf);
141 if (err < 0)
142 return err;
143
144 if (S_ISDIR(buf.ust_mode))
145 return OS_TYPE_DIR;
146 else if (S_ISLNK(buf.ust_mode))
147 return OS_TYPE_SYMLINK;
148 else if (S_ISCHR(buf.ust_mode))
149 return OS_TYPE_CHARDEV;
150 else if (S_ISBLK(buf.ust_mode))
151 return OS_TYPE_BLOCKDEV;
152 else if (S_ISFIFO(buf.ust_mode))
153 return OS_TYPE_FIFO;
154 else if (S_ISSOCK(buf.ust_mode))
155 return OS_TYPE_SOCK;
156 else return OS_TYPE_FILE;
157 }
158
159 int os_file_mode(const char *file, struct openflags *mode_out)
160 {
161 int err;
162
163 *mode_out = OPENFLAGS();
164
165 err = access(file, W_OK);
166 if (err && (errno != EACCES))
167 return -errno;
168 else if (!err)
169 *mode_out = of_write(*mode_out);
170
171 err = access(file, R_OK);
172 if (err && (errno != EACCES))
173 return -errno;
174 else if (!err)
175 *mode_out = of_read(*mode_out);
176
177 return err;
178 }
179
180 int os_open_file(const char *file, struct openflags flags, int mode)
181 {
182 int fd, err, f = 0;
183
184 if (flags.r && flags.w)
185 f = O_RDWR;
186 else if (flags.r)
187 f = O_RDONLY;
188 else if (flags.w)
189 f = O_WRONLY;
190 else f = 0;
191
192 if (flags.s)
193 f |= O_SYNC;
194 if (flags.c)
195 f |= O_CREAT;
196 if (flags.t)
197 f |= O_TRUNC;
198 if (flags.e)
199 f |= O_EXCL;
200 if (flags.a)
201 f |= O_APPEND;
202
203 fd = open64(file, f, mode);
204 if (fd < 0)
205 return -errno;
206
207 if (flags.cl && fcntl(fd, F_SETFD, 1)) {
208 err = -errno;
209 close(fd);
210 return err;
211 }
212
213 return fd;
214 }
215
216 int os_connect_socket(const char *name)
217 {
218 struct sockaddr_un sock;
219 int fd, err;
220
221 sock.sun_family = AF_UNIX;
222 snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
223
224 fd = socket(AF_UNIX, SOCK_STREAM, 0);
225 if (fd < 0) {
226 err = -errno;
227 goto out;
228 }
229
230 err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
231 if (err) {
232 err = -errno;
233 goto out_close;
234 }
235
236 return fd;
237
238 out_close:
239 close(fd);
240 out:
241 return err;
242 }
243
244 int os_dup_file(int fd)
245 {
246 int new_fd = dup(fd);
247
248 if (new_fd < 0)
249 return -errno;
250
251 return new_fd;
252 }
253
254 void os_close_file(int fd)
255 {
256 close(fd);
257 }
258 int os_fsync_file(int fd)
259 {
260 if (fsync(fd) < 0)
261 return -errno;
262 return 0;
263 }
264
265 int os_seek_file(int fd, unsigned long long offset)
266 {
267 unsigned long long actual;
268
269 actual = lseek64(fd, offset, SEEK_SET);
270 if (actual != offset)
271 return -errno;
272 return 0;
273 }
274
275 int os_read_file(int fd, void *buf, int len)
276 {
277 int n = read(fd, buf, len);
278
279 if (n < 0)
280 return -errno;
281 return n;
282 }
283
284 int os_pread_file(int fd, void *buf, int len, unsigned long long offset)
285 {
286 int n = pread(fd, buf, len, offset);
287
288 if (n < 0)
289 return -errno;
290 return n;
291 }
292
293 int os_write_file(int fd, const void *buf, int len)
294 {
295 int n = write(fd, (void *) buf, len);
296
297 if (n < 0)
298 return -errno;
299 return n;
300 }
301
302 int os_sync_file(int fd)
303 {
304 int n = fdatasync(fd);
305
306 if (n < 0)
307 return -errno;
308 return n;
309 }
310
311 int os_pwrite_file(int fd, const void *buf, int len, unsigned long long offset)
312 {
313 int n = pwrite(fd, (void *) buf, len, offset);
314
315 if (n < 0)
316 return -errno;
317 return n;
318 }
319
320
321 int os_file_size(const char *file, unsigned long long *size_out)
322 {
323 struct uml_stat buf;
324 int err;
325
326 err = os_stat_file(file, &buf);
327 if (err < 0) {
328 printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
329 -err);
330 return err;
331 }
332
333 if (S_ISBLK(buf.ust_mode)) {
334 int fd;
335 long blocks;
336
337 fd = open(file, O_RDONLY, 0);
338 if (fd < 0) {
339 err = -errno;
340 printk(UM_KERN_ERR "Couldn't open \"%s\", "
341 "errno = %d\n", file, errno);
342 return err;
343 }
344 if (ioctl(fd, BLKGETSIZE, &blocks) < 0) {
345 err = -errno;
346 printk(UM_KERN_ERR "Couldn't get the block size of "
347 "\"%s\", errno = %d\n", file, errno);
348 close(fd);
349 return err;
350 }
351 *size_out = ((long long) blocks) * 512;
352 close(fd);
353 }
354 else *size_out = buf.ust_size;
355
356 return 0;
357 }
358
359 int os_file_modtime(const char *file, long long *modtime)
360 {
361 struct uml_stat buf;
362 int err;
363
364 err = os_stat_file(file, &buf);
365 if (err < 0) {
366 printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
367 -err);
368 return err;
369 }
370
371 *modtime = buf.ust_mtime;
372 return 0;
373 }
374
375 int os_set_exec_close(int fd)
376 {
377 int err;
378
379 CATCH_EINTR(err = fcntl(fd, F_SETFD, FD_CLOEXEC));
380
381 if (err < 0)
382 return -errno;
383 return err;
384 }
385
386 int os_pipe(int *fds, int stream, int close_on_exec)
387 {
388 int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
389
390 err = socketpair(AF_UNIX, type, 0, fds);
391 if (err < 0)
392 return -errno;
393
394 if (!close_on_exec)
395 return 0;
396
397 err = os_set_exec_close(fds[0]);
398 if (err < 0)
399 goto error;
400
401 err = os_set_exec_close(fds[1]);
402 if (err < 0)
403 goto error;
404
405 return 0;
406
407 error:
408 printk(UM_KERN_ERR "os_pipe : Setting FD_CLOEXEC failed, err = %d\n",
409 -err);
410 close(fds[1]);
411 close(fds[0]);
412 return err;
413 }
414
415 int os_set_fd_async(int fd)
416 {
417 int err, flags;
418
419 flags = fcntl(fd, F_GETFL);
420 if (flags < 0)
421 return -errno;
422
423 flags |= O_ASYNC | O_NONBLOCK;
424 if (fcntl(fd, F_SETFL, flags) < 0) {
425 err = -errno;
426 printk(UM_KERN_ERR "os_set_fd_async : failed to set O_ASYNC "
427 "and O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
428 return err;
429 }
430
431 if ((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
432 (fcntl(fd, F_SETOWN, os_getpid()) < 0)) {
433 err = -errno;
434 printk(UM_KERN_ERR "os_set_fd_async : Failed to fcntl F_SETOWN "
435 "(or F_SETSIG) fd %d, errno = %d\n", fd, errno);
436 return err;
437 }
438
439 return 0;
440 }
441
442 int os_clear_fd_async(int fd)
443 {
444 int flags;
445
446 flags = fcntl(fd, F_GETFL);
447 if (flags < 0)
448 return -errno;
449
450 flags &= ~(O_ASYNC | O_NONBLOCK);
451 if (fcntl(fd, F_SETFL, flags) < 0)
452 return -errno;
453 return 0;
454 }
455
456 int os_set_fd_block(int fd, int blocking)
457 {
458 int flags;
459
460 flags = fcntl(fd, F_GETFL);
461 if (flags < 0)
462 return -errno;
463
464 if (blocking)
465 flags &= ~O_NONBLOCK;
466 else
467 flags |= O_NONBLOCK;
468
469 if (fcntl(fd, F_SETFL, flags) < 0)
470 return -errno;
471
472 return 0;
473 }
474
475 int os_accept_connection(int fd)
476 {
477 int new;
478
479 new = accept(fd, NULL, 0);
480 if (new < 0)
481 return -errno;
482 return new;
483 }
484
485 #ifndef SHUT_RD
486 #define SHUT_RD 0
487 #endif
488
489 #ifndef SHUT_WR
490 #define SHUT_WR 1
491 #endif
492
493 #ifndef SHUT_RDWR
494 #define SHUT_RDWR 2
495 #endif
496
497 int os_shutdown_socket(int fd, int r, int w)
498 {
499 int what, err;
500
501 if (r && w)
502 what = SHUT_RDWR;
503 else if (r)
504 what = SHUT_RD;
505 else if (w)
506 what = SHUT_WR;
507 else
508 return -EINVAL;
509
510 err = shutdown(fd, what);
511 if (err < 0)
512 return -errno;
513 return 0;
514 }
515
516 /**
517 * os_rcv_fd_msg - receive message with (optional) FDs
518 * @fd: the FD to receive from
519 * @fds: the array for FDs to write to
520 * @n_fds: number of FDs to receive (@fds array size)
521 * @data: the message buffer
522 * @data_len: the size of the message to receive
523 *
524 * Receive a message with FDs.
525 *
526 * Returns: the size of the received message, or an error code
527 */
528 ssize_t os_rcv_fd_msg(int fd, int *fds, unsigned int n_fds,
529 void *data, size_t data_len)
530 {
531 char buf[CMSG_SPACE(sizeof(*fds) * n_fds)];
532 struct cmsghdr *cmsg;
533 struct iovec iov = {
534 .iov_base = data,
535 .iov_len = data_len,
536 };
537 struct msghdr msg = {
538 .msg_iov = &iov,
539 .msg_iovlen = 1,
540 .msg_control = buf,
541 .msg_controllen = sizeof(buf),
542 };
543 int n;
544
545 n = recvmsg(fd, &msg, 0);
546 if (n < 0)
547 return -errno;
548
549 cmsg = CMSG_FIRSTHDR(&msg);
550 if (!cmsg ||
551 cmsg->cmsg_level != SOL_SOCKET ||
552 cmsg->cmsg_type != SCM_RIGHTS)
553 return n;
554
555 memcpy(fds, CMSG_DATA(cmsg), cmsg->cmsg_len);
556 return n;
557 }
558
559 int os_create_unix_socket(const char *file, int len, int close_on_exec)
560 {
561 struct sockaddr_un addr;
562 int sock, err;
563
564 sock = socket(PF_UNIX, SOCK_DGRAM, 0);
565 if (sock < 0)
566 return -errno;
567
568 if (close_on_exec) {
569 err = os_set_exec_close(sock);
570 if (err < 0)
571 printk(UM_KERN_ERR "create_unix_socket : "
572 "close_on_exec failed, err = %d", -err);
573 }
574
575 addr.sun_family = AF_UNIX;
576
577 snprintf(addr.sun_path, len, "%s", file);
578
579 err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
580 if (err < 0)
581 return -errno;
582
583 return sock;
584 }
585
586 void os_flush_stdout(void)
587 {
588 fflush(stdout);
589 }
590
591 int os_lock_file(int fd, int excl)
592 {
593 int type = excl ? F_WRLCK : F_RDLCK;
594 struct flock lock = ((struct flock) { .l_type = type,
595 .l_whence = SEEK_SET,
596 .l_start = 0,
597 .l_len = 0 } );
598 int err, save;
599
600 err = fcntl(fd, F_SETLK, &lock);
601 if (!err)
602 goto out;
603
604 save = -errno;
605 err = fcntl(fd, F_GETLK, &lock);
606 if (err) {
607 err = -errno;
608 goto out;
609 }
610
611 printk(UM_KERN_ERR "F_SETLK failed, file already locked by pid %d\n",
612 lock.l_pid);
613 err = save;
614 out:
615 return err;
616 }
617
618 unsigned os_major(unsigned long long dev)
619 {
620 return major(dev);
621 }
622
623 unsigned os_minor(unsigned long long dev)
624 {
625 return minor(dev);
626 }
627
628 unsigned long long os_makedev(unsigned major, unsigned minor)
629 {
630 return makedev(major, minor);
631 }
632
633 int os_falloc_punch(int fd, unsigned long long offset, int len)
634 {
635 int n = fallocate(fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, offset, len);
636
637 if (n < 0)
638 return -errno;
639 return n;
640 }
641
642 int os_falloc_zeroes(int fd, unsigned long long offset, int len)
643 {
644 int n = fallocate(fd, FALLOC_FL_ZERO_RANGE|FALLOC_FL_KEEP_SIZE, offset, len);
645
646 if (n < 0)
647 return -errno;
648 return n;
649 }
650
651 int os_eventfd(unsigned int initval, int flags)
652 {
653 int fd = eventfd(initval, flags);
654
655 if (fd < 0)
656 return -errno;
657 return fd;
658 }
659
660 int os_sendmsg_fds(int fd, const void *buf, unsigned int len, const int *fds,
661 unsigned int fds_num)
662 {
663 struct iovec iov = {
664 .iov_base = (void *) buf,
665 .iov_len = len,
666 };
667 union {
668 char control[CMSG_SPACE(sizeof(*fds) * OS_SENDMSG_MAX_FDS)];
669 struct cmsghdr align;
670 } u;
671 unsigned int fds_size = sizeof(*fds) * fds_num;
672 struct msghdr msg = {
673 .msg_iov = &iov,
674 .msg_iovlen = 1,
675 .msg_control = u.control,
676 .msg_controllen = CMSG_SPACE(fds_size),
677 };
678 struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
679 int err;
680
681 if (fds_num > OS_SENDMSG_MAX_FDS)
682 return -EINVAL;
683 memset(u.control, 0, sizeof(u.control));
684 cmsg->cmsg_level = SOL_SOCKET;
685 cmsg->cmsg_type = SCM_RIGHTS;
686 cmsg->cmsg_len = CMSG_LEN(fds_size);
687 memcpy(CMSG_DATA(cmsg), fds, fds_size);
688 err = sendmsg(fd, &msg, 0);
689
690 if (err < 0)
691 return -errno;
692 return err;
693 }
694
695 int os_poll(unsigned int n, const int *fds)
696 {
697 /* currently need 2 FDs at most so avoid dynamic allocation */
698 struct pollfd pollfds[2] = {};
699 unsigned int i;
700 int ret;
701
702 if (n > ARRAY_SIZE(pollfds))
703 return -EINVAL;
704
705 for (i = 0; i < n; i++) {
706 pollfds[i].fd = fds[i];
707 pollfds[i].events = POLLIN;
708 }
709
710 ret = poll(pollfds, n, -1);
711 if (ret < 0)
712 return -errno;
713
714 /* Return the index of the available FD */
715 for (i = 0; i < n; i++) {
716 if (pollfds[i].revents)
717 return i;
718 }
719
720 return -EIO;
721 }
722
723 void *os_mmap_rw_shared(int fd, size_t size)
724 {
725 void *res = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
726
727 if (res == MAP_FAILED)
728 return NULL;
729
730 return res;
731 }
732
733 void *os_mremap_rw_shared(void *old_addr, size_t old_size, size_t new_size)
734 {
735 void *res;
736
737 res = mremap(old_addr, old_size, new_size, MREMAP_MAYMOVE, NULL);
738
739 if (res == MAP_FAILED)
740 return NULL;
741
742 return res;
743 }
744
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