xref: /openbmc/linux/arch/um/os-Linux/file.c (revision d2a0a616)
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 
copy_stat(struct uml_stat * dst,const struct stat64 * src)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 
os_stat_fd(const int fd,struct uml_stat * ubuf)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 
os_stat_file(const char * file_name,struct uml_stat * ubuf)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 
os_access(const char * file,int mode)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) */
os_ioctl_generic(int fd,unsigned int cmd,unsigned long arg)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 */
os_get_ifname(int fd,char * namebuf)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 
os_set_slip(int fd)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 
os_mode_fd(int fd,int mode)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 
os_file_type(char * file)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 
os_file_mode(const char * file,struct openflags * mode_out)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 
os_open_file(const char * file,struct openflags flags,int mode)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 
os_connect_socket(const char * name)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 
os_close_file(int fd)243 void os_close_file(int fd)
244 {
245 	close(fd);
246 }
os_fsync_file(int fd)247 int os_fsync_file(int fd)
248 {
249 	if (fsync(fd) < 0)
250 	    return -errno;
251 	return 0;
252 }
253 
os_seek_file(int fd,unsigned long long offset)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 
os_read_file(int fd,void * buf,int len)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 
os_pread_file(int fd,void * buf,int len,unsigned long long offset)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 
os_write_file(int fd,const void * buf,int len)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 
os_sync_file(int fd)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 
os_pwrite_file(int fd,const void * buf,int len,unsigned long long offset)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 
os_file_size(const char * file,unsigned long long * size_out)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 
os_file_modtime(const char * file,long long * modtime)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 
os_set_exec_close(int fd)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 
os_pipe(int * fds,int stream,int close_on_exec)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 
os_set_fd_async(int fd)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 
os_clear_fd_async(int fd)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 
os_set_fd_block(int fd,int blocking)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 
os_accept_connection(int fd)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 
os_shutdown_socket(int fd,int r,int w)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 
os_rcv_fd(int fd,int * helper_pid_out)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 
os_create_unix_socket(const char * file,int len,int close_on_exec)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 
os_flush_stdout(void)572 void os_flush_stdout(void)
573 {
574 	fflush(stdout);
575 }
576 
os_lock_file(int fd,int excl)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 
os_major(unsigned long long dev)604 unsigned os_major(unsigned long long dev)
605 {
606 	return major(dev);
607 }
608 
os_minor(unsigned long long dev)609 unsigned os_minor(unsigned long long dev)
610 {
611 	return minor(dev);
612 }
613 
os_makedev(unsigned major,unsigned minor)614 unsigned long long os_makedev(unsigned major, unsigned minor)
615 {
616 	return makedev(major, minor);
617 }
618 
os_falloc_punch(int fd,unsigned long long offset,int len)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 
os_falloc_zeroes(int fd,unsigned long long offset,int len)628 int os_falloc_zeroes(int fd, unsigned long long offset, int len)
629 {
630 	int n = fallocate(fd, FALLOC_FL_ZERO_RANGE|FALLOC_FL_KEEP_SIZE, offset, len);
631 
632 	if (n < 0)
633 		return -errno;
634 	return n;
635 }
636 
os_eventfd(unsigned int initval,int flags)637 int os_eventfd(unsigned int initval, int flags)
638 {
639 	int fd = eventfd(initval, flags);
640 
641 	if (fd < 0)
642 		return -errno;
643 	return fd;
644 }
645 
os_sendmsg_fds(int fd,const void * buf,unsigned int len,const int * fds,unsigned int fds_num)646 int os_sendmsg_fds(int fd, const void *buf, unsigned int len, const int *fds,
647 		   unsigned int fds_num)
648 {
649 	struct iovec iov = {
650 		.iov_base = (void *) buf,
651 		.iov_len = len,
652 	};
653 	union {
654 		char control[CMSG_SPACE(sizeof(*fds) * OS_SENDMSG_MAX_FDS)];
655 		struct cmsghdr align;
656 	} u;
657 	unsigned int fds_size = sizeof(*fds) * fds_num;
658 	struct msghdr msg = {
659 		.msg_iov = &iov,
660 		.msg_iovlen = 1,
661 		.msg_control = u.control,
662 		.msg_controllen = CMSG_SPACE(fds_size),
663 	};
664 	struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
665 	int err;
666 
667 	if (fds_num > OS_SENDMSG_MAX_FDS)
668 		return -EINVAL;
669 	memset(u.control, 0, sizeof(u.control));
670 	cmsg->cmsg_level = SOL_SOCKET;
671 	cmsg->cmsg_type = SCM_RIGHTS;
672 	cmsg->cmsg_len = CMSG_LEN(fds_size);
673 	memcpy(CMSG_DATA(cmsg), fds, fds_size);
674 	err = sendmsg(fd, &msg, 0);
675 
676 	if (err < 0)
677 		return -errno;
678 	return err;
679 }
680 
os_poll(unsigned int n,const int * fds)681 int os_poll(unsigned int n, const int *fds)
682 {
683 	/* currently need 2 FDs at most so avoid dynamic allocation */
684 	struct pollfd pollfds[2] = {};
685 	unsigned int i;
686 	int ret;
687 
688 	if (n > ARRAY_SIZE(pollfds))
689 		return -EINVAL;
690 
691 	for (i = 0; i < n; i++) {
692 		pollfds[i].fd = fds[i];
693 		pollfds[i].events = POLLIN;
694 	}
695 
696 	ret = poll(pollfds, n, -1);
697 	if (ret < 0)
698 		return -errno;
699 
700 	/* Return the index of the available FD */
701 	for (i = 0; i < n; i++) {
702 		if (pollfds[i].revents)
703 			return i;
704 	}
705 
706 	return -EIO;
707 }
708