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