xref: /linux/arch/um/os-Linux/file.c (revision 36ca1195ad7f760a6af3814cb002bd3a3d4b4db1)
1 /*
2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5 
6 #include <stdio.h>
7 #include <unistd.h>
8 #include <errno.h>
9 #include <fcntl.h>
10 #include <signal.h>
11 #include <sys/types.h>
12 #include <sys/stat.h>
13 #include <sys/socket.h>
14 #include <sys/un.h>
15 #include <sys/ioctl.h>
16 #include <sys/mount.h>
17 #include <sys/uio.h>
18 #include "os.h"
19 #include "user.h"
20 #include "kern_util.h"
21 
22 static void copy_stat(struct uml_stat *dst, struct stat64 *src)
23 {
24 	*dst = ((struct uml_stat) {
25 		.ust_dev     = src->st_dev,     /* device */
26 		.ust_ino     = src->st_ino,     /* inode */
27 		.ust_mode    = src->st_mode,    /* protection */
28 		.ust_nlink   = src->st_nlink,   /* number of hard links */
29 		.ust_uid     = src->st_uid,     /* user ID of owner */
30 		.ust_gid     = src->st_gid,     /* group ID of owner */
31 		.ust_size    = src->st_size,    /* total size, in bytes */
32 		.ust_blksize = src->st_blksize, /* blocksize for filesys I/O */
33 		.ust_blocks  = src->st_blocks,  /* number of blocks allocated */
34 		.ust_atime   = src->st_atime,   /* time of last access */
35 		.ust_mtime   = src->st_mtime,   /* time of last modification */
36 		.ust_ctime   = src->st_ctime,   /* time of last change */
37 	});
38 }
39 
40 int os_stat_fd(const int fd, struct uml_stat *ubuf)
41 {
42 	struct stat64 sbuf;
43 	int err;
44 
45 	do {
46 		err = fstat64(fd, &sbuf);
47 	} while((err < 0) && (errno == EINTR)) ;
48 
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 	do {
63 		err = stat64(file_name, &sbuf);
64 	} while((err < 0) && (errno == EINTR)) ;
65 
66 	if(err < 0)
67 		return(-errno);
68 
69 	if(ubuf != NULL)
70 		copy_stat(ubuf, &sbuf);
71 	return(err);
72 }
73 
74 int os_access(const char* file, int mode)
75 {
76 	int amode, err;
77 
78 	amode=(mode&OS_ACC_R_OK ? R_OK : 0) | (mode&OS_ACC_W_OK ? W_OK : 0) |
79 	      (mode&OS_ACC_X_OK ? X_OK : 0) | (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 void os_print_error(int error, const char* str)
89 {
90 	errno = error < 0 ? -error : error;
91 
92 	perror(str);
93 }
94 
95 /* FIXME? required only by hostaudio (because it passes ioctls verbatim) */
96 int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
97 {
98 	int err;
99 
100 	err = ioctl(fd, cmd, arg);
101 	if(err < 0)
102 		return(-errno);
103 
104 	return(err);
105 }
106 
107 int os_window_size(int fd, int *rows, int *cols)
108 {
109 	struct winsize size;
110 
111 	if(ioctl(fd, TIOCGWINSZ, &size) < 0)
112 		return(-errno);
113 
114 	*rows = size.ws_row;
115 	*cols = size.ws_col;
116 
117 	return(0);
118 }
119 
120 int os_new_tty_pgrp(int fd, int pid)
121 {
122 	if(ioctl(fd, TIOCSCTTY, 0) < 0){
123 		printk("TIOCSCTTY failed, errno = %d\n", errno);
124 		return(-errno);
125 	}
126 
127 	if(tcsetpgrp(fd, pid) < 0){
128 		printk("tcsetpgrp failed, errno = %d\n", errno);
129 		return(-errno);
130 	}
131 
132 	return(0);
133 }
134 
135 /* FIXME: ensure namebuf in os_get_if_name is big enough */
136 int os_get_ifname(int fd, char* namebuf)
137 {
138 	if(ioctl(fd, SIOCGIFNAME, namebuf) < 0)
139 		return(-errno);
140 
141 	return(0);
142 }
143 
144 int os_set_slip(int fd)
145 {
146 	int disc, sencap;
147 
148 	disc = N_SLIP;
149 	if(ioctl(fd, TIOCSETD, &disc) < 0){
150 		printk("Failed to set slip line discipline - "
151 		       "errno = %d\n", errno);
152 		return(-errno);
153 	}
154 
155 	sencap = 0;
156 	if(ioctl(fd, SIOCSIFENCAP, &sencap) < 0){
157 		printk("Failed to set slip encapsulation - "
158 		       "errno = %d\n", errno);
159 		return(-errno);
160 	}
161 
162 	return(0);
163 }
164 
165 int os_set_owner(int fd, int pid)
166 {
167 	if(fcntl(fd, F_SETOWN, pid) < 0){
168 		int save_errno = errno;
169 
170 		if(fcntl(fd, F_GETOWN, 0) != pid)
171 			return(-save_errno);
172 	}
173 
174 	return(0);
175 }
176 
177 /* FIXME? moved wholesale from sigio_user.c to get fcntls out of that file */
178 int os_sigio_async(int master, int slave)
179 {
180 	int flags;
181 
182 	flags = fcntl(master, F_GETFL);
183 	if(flags < 0) {
184 		printk("fcntl F_GETFL failed, errno = %d\n", errno);
185 		return(-errno);
186 	}
187 
188 	if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||
189 	   (fcntl(master, F_SETOWN, os_getpid()) < 0)){
190 		printk("fcntl F_SETFL or F_SETOWN failed, errno = %d\n",
191 		       errno);
192 		return(-errno);
193 	}
194 
195 	if((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0)){
196 		printk("fcntl F_SETFL failed, errno = %d\n", errno);
197 		return(-errno);
198 	}
199 
200 	return(0);
201 }
202 
203 int os_mode_fd(int fd, int mode)
204 {
205 	int err;
206 
207 	do {
208 		err = fchmod(fd, mode);
209 	} while((err < 0) && (errno==EINTR)) ;
210 
211 	if(err < 0)
212 		return(-errno);
213 
214 	return(0);
215 }
216 
217 int os_file_type(char *file)
218 {
219 	struct uml_stat buf;
220 	int err;
221 
222 	err = os_stat_file(file, &buf);
223 	if(err < 0)
224 		return(err);
225 
226 	if(S_ISDIR(buf.ust_mode)) return(OS_TYPE_DIR);
227 	else if(S_ISLNK(buf.ust_mode)) return(OS_TYPE_SYMLINK);
228 	else if(S_ISCHR(buf.ust_mode)) return(OS_TYPE_CHARDEV);
229 	else if(S_ISBLK(buf.ust_mode)) return(OS_TYPE_BLOCKDEV);
230 	else if(S_ISFIFO(buf.ust_mode)) return(OS_TYPE_FIFO);
231 	else if(S_ISSOCK(buf.ust_mode)) return(OS_TYPE_SOCK);
232 	else return(OS_TYPE_FILE);
233 }
234 
235 int os_file_mode(char *file, struct openflags *mode_out)
236 {
237 	int err;
238 
239 	*mode_out = OPENFLAGS();
240 
241 	err = os_access(file, OS_ACC_W_OK);
242 	if((err < 0) && (err != -EACCES))
243 		return(err);
244 
245 	*mode_out = of_write(*mode_out);
246 
247 	err = os_access(file, OS_ACC_R_OK);
248 	if((err < 0) && (err != -EACCES))
249 		return(err);
250 
251 	*mode_out = of_read(*mode_out);
252 
253 	return(0);
254 }
255 
256 int os_open_file(char *file, struct openflags flags, int mode)
257 {
258 	int fd, f = 0;
259 
260 	if(flags.r && flags.w) f = O_RDWR;
261 	else if(flags.r) f = O_RDONLY;
262 	else if(flags.w) f = O_WRONLY;
263 	else f = 0;
264 
265 	if(flags.s) f |= O_SYNC;
266 	if(flags.c) f |= O_CREAT;
267 	if(flags.t) f |= O_TRUNC;
268 	if(flags.e) f |= O_EXCL;
269 
270 	fd = open64(file, f, mode);
271 	if(fd < 0)
272 		return(-errno);
273 
274 	if(flags.cl && fcntl(fd, F_SETFD, 1)){
275 		os_close_file(fd);
276 		return(-errno);
277 	}
278 
279 	return(fd);
280 }
281 
282 int os_connect_socket(char *name)
283 {
284 	struct sockaddr_un sock;
285 	int fd, err;
286 
287 	sock.sun_family = AF_UNIX;
288 	snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
289 
290 	fd = socket(AF_UNIX, SOCK_STREAM, 0);
291 	if(fd < 0)
292 		return(fd);
293 
294 	err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
295 	if(err)
296 		return(-errno);
297 
298 	return(fd);
299 }
300 
301 void os_close_file(int fd)
302 {
303 	close(fd);
304 }
305 
306 int os_seek_file(int fd, __u64 offset)
307 {
308 	__u64 actual;
309 
310 	actual = lseek64(fd, offset, SEEK_SET);
311 	if(actual != offset)
312 		return(-errno);
313 	return(0);
314 }
315 
316 static int fault_buffer(void *start, int len,
317 			int (*copy_proc)(void *addr, void *buf, int len))
318 {
319 	int page = getpagesize(), i;
320 	char c;
321 
322 	for(i = 0; i < len; i += page){
323 		if((*copy_proc)(start + i, &c, sizeof(c)))
324 			return(-EFAULT);
325 	}
326 	if((len % page) != 0){
327 		if((*copy_proc)(start + len - 1, &c, sizeof(c)))
328 			return(-EFAULT);
329 	}
330 	return(0);
331 }
332 
333 static int file_io(int fd, void *buf, int len,
334 		   int (*io_proc)(int fd, void *buf, int len),
335 		   int (*copy_user_proc)(void *addr, void *buf, int len))
336 {
337 	int n, err;
338 
339 	do {
340 		n = (*io_proc)(fd, buf, len);
341 		if((n < 0) && (errno == EFAULT)){
342 			err = fault_buffer(buf, len, copy_user_proc);
343 			if(err)
344 				return(err);
345 			n = (*io_proc)(fd, buf, len);
346 		}
347 	} while((n < 0) && (errno == EINTR));
348 
349 	if(n < 0)
350 		return(-errno);
351 	return(n);
352 }
353 
354 int os_read_file(int fd, void *buf, int len)
355 {
356 	return(file_io(fd, buf, len, (int (*)(int, void *, int)) read,
357 		       copy_from_user_proc));
358 }
359 
360 int os_write_file(int fd, const void *buf, int len)
361 {
362 	return(file_io(fd, (void *) buf, len,
363 		       (int (*)(int, void *, int)) write, copy_to_user_proc));
364 }
365 
366 int os_file_size(char *file, unsigned long long *size_out)
367 {
368 	struct uml_stat buf;
369 	int err;
370 
371 	err = os_stat_file(file, &buf);
372 	if(err < 0){
373 		printk("Couldn't stat \"%s\" : err = %d\n", file, -err);
374 		return(err);
375 	}
376 
377 	if(S_ISBLK(buf.ust_mode)){
378 		int fd, blocks;
379 
380 		fd = os_open_file(file, of_read(OPENFLAGS()), 0);
381 		if(fd < 0){
382 			printk("Couldn't open \"%s\", errno = %d\n", file, -fd);
383 			return(fd);
384 		}
385 		if(ioctl(fd, BLKGETSIZE, &blocks) < 0){
386 			printk("Couldn't get the block size of \"%s\", "
387 			       "errno = %d\n", file, errno);
388 			err = -errno;
389 			os_close_file(fd);
390 			return(err);
391 		}
392 		*size_out = ((long long) blocks) * 512;
393 		os_close_file(fd);
394 		return(0);
395 	}
396 	*size_out = buf.ust_size;
397 	return(0);
398 }
399 
400 int os_file_modtime(char *file, unsigned long *modtime)
401 {
402 	struct uml_stat buf;
403 	int err;
404 
405 	err = os_stat_file(file, &buf);
406 	if(err < 0){
407 		printk("Couldn't stat \"%s\" : err = %d\n", file, -err);
408 		return(err);
409 	}
410 
411 	*modtime = buf.ust_mtime;
412 	return(0);
413 }
414 
415 int os_get_exec_close(int fd, int* close_on_exec)
416 {
417 	int ret;
418 
419 	do {
420 		ret = fcntl(fd, F_GETFD);
421 	} while((ret < 0) && (errno == EINTR)) ;
422 
423 	if(ret < 0)
424 		return(-errno);
425 
426 	*close_on_exec = (ret&FD_CLOEXEC) ? 1 : 0;
427 	return(ret);
428 }
429 
430 int os_set_exec_close(int fd, int close_on_exec)
431 {
432 	int flag, err;
433 
434 	if(close_on_exec) flag = FD_CLOEXEC;
435 	else flag = 0;
436 
437 	do {
438 		err = fcntl(fd, F_SETFD, flag);
439 	} while((err < 0) && (errno == EINTR)) ;
440 
441 	if(err < 0)
442 		return(-errno);
443 	return(err);
444 }
445 
446 int os_pipe(int *fds, int stream, int close_on_exec)
447 {
448 	int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
449 
450 	err = socketpair(AF_UNIX, type, 0, fds);
451 	if(err < 0)
452 		return(-errno);
453 
454 	if(!close_on_exec)
455 		return(0);
456 
457 	err = os_set_exec_close(fds[0], 1);
458 	if(err < 0)
459 		goto error;
460 
461 	err = os_set_exec_close(fds[1], 1);
462 	if(err < 0)
463 		goto error;
464 
465 	return(0);
466 
467  error:
468 	printk("os_pipe : Setting FD_CLOEXEC failed, err = %d\n", -err);
469 	os_close_file(fds[1]);
470 	os_close_file(fds[0]);
471 	return(err);
472 }
473 
474 int os_set_fd_async(int fd, int owner)
475 {
476 	/* XXX This should do F_GETFL first */
477 	if(fcntl(fd, F_SETFL, O_ASYNC | O_NONBLOCK) < 0){
478 		printk("os_set_fd_async : failed to set O_ASYNC and "
479 		       "O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
480 		return(-errno);
481 	}
482 #ifdef notdef
483 	if(fcntl(fd, F_SETFD, 1) < 0){
484 		printk("os_set_fd_async : Setting FD_CLOEXEC failed, "
485 		       "errno = %d\n", errno);
486 	}
487 #endif
488 
489 	if((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
490 	   (fcntl(fd, F_SETOWN, owner) < 0)){
491 		printk("os_set_fd_async : Failed to fcntl F_SETOWN "
492 		       "(or F_SETSIG) fd %d to pid %d, errno = %d\n", fd,
493 		       owner, errno);
494 		return(-errno);
495 	}
496 
497 	return(0);
498 }
499 
500 int os_clear_fd_async(int fd)
501 {
502 	int flags = fcntl(fd, F_GETFL);
503 
504 	flags &= ~(O_ASYNC | O_NONBLOCK);
505 	if(fcntl(fd, F_SETFL, flags) < 0)
506 		return(-errno);
507 	return(0);
508 }
509 
510 int os_set_fd_block(int fd, int blocking)
511 {
512 	int flags;
513 
514 	flags = fcntl(fd, F_GETFL);
515 
516 	if(blocking) flags &= ~O_NONBLOCK;
517 	else flags |= O_NONBLOCK;
518 
519 	if(fcntl(fd, F_SETFL, flags) < 0){
520 		printk("Failed to change blocking on fd # %d, errno = %d\n",
521 		       fd, errno);
522 		return(-errno);
523 	}
524 	return(0);
525 }
526 
527 int os_accept_connection(int fd)
528 {
529 	int new;
530 
531 	new = accept(fd, NULL, 0);
532 	if(new < 0)
533 		return(-errno);
534 	return(new);
535 }
536 
537 #ifndef SHUT_RD
538 #define SHUT_RD 0
539 #endif
540 
541 #ifndef SHUT_WR
542 #define SHUT_WR 1
543 #endif
544 
545 #ifndef SHUT_RDWR
546 #define SHUT_RDWR 2
547 #endif
548 
549 int os_shutdown_socket(int fd, int r, int w)
550 {
551 	int what, err;
552 
553 	if(r && w) what = SHUT_RDWR;
554 	else if(r) what = SHUT_RD;
555 	else if(w) what = SHUT_WR;
556 	else {
557 		printk("os_shutdown_socket : neither r or w was set\n");
558 		return(-EINVAL);
559 	}
560 	err = shutdown(fd, what);
561 	if(err < 0)
562 		return(-errno);
563 	return(0);
564 }
565 
566 int os_rcv_fd(int fd, int *helper_pid_out)
567 {
568 	int new, n;
569 	char buf[CMSG_SPACE(sizeof(new))];
570 	struct msghdr msg;
571 	struct cmsghdr *cmsg;
572 	struct iovec iov;
573 
574 	msg.msg_name = NULL;
575 	msg.msg_namelen = 0;
576 	iov = ((struct iovec) { .iov_base  = helper_pid_out,
577 				.iov_len   = sizeof(*helper_pid_out) });
578 	msg.msg_iov = &iov;
579 	msg.msg_iovlen = 1;
580 	msg.msg_control = buf;
581 	msg.msg_controllen = sizeof(buf);
582 	msg.msg_flags = 0;
583 
584 	n = recvmsg(fd, &msg, 0);
585 	if(n < 0)
586 		return(-errno);
587 
588 	else if(n != sizeof(iov.iov_len))
589 		*helper_pid_out = -1;
590 
591 	cmsg = CMSG_FIRSTHDR(&msg);
592 	if(cmsg == NULL){
593 		printk("rcv_fd didn't receive anything, error = %d\n", errno);
594 		return(-1);
595 	}
596 	if((cmsg->cmsg_level != SOL_SOCKET) ||
597 	   (cmsg->cmsg_type != SCM_RIGHTS)){
598 		printk("rcv_fd didn't receive a descriptor\n");
599 		return(-1);
600 	}
601 
602 	new = ((int *) CMSG_DATA(cmsg))[0];
603 	return(new);
604 }
605 
606 int os_create_unix_socket(char *file, int len, int close_on_exec)
607 {
608 	struct sockaddr_un addr;
609 	int sock, err;
610 
611 	sock = socket(PF_UNIX, SOCK_DGRAM, 0);
612 	if (sock < 0){
613 		printk("create_unix_socket - socket failed, errno = %d\n",
614 		       errno);
615 		return(-errno);
616 	}
617 
618 	if(close_on_exec) {
619 		err = os_set_exec_close(sock, 1);
620 		if(err < 0)
621 			printk("create_unix_socket : close_on_exec failed, "
622 		       "err = %d", -err);
623 	}
624 
625 	addr.sun_family = AF_UNIX;
626 
627 	/* XXX Be more careful about overflow */
628 	snprintf(addr.sun_path, len, "%s", file);
629 
630 	err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
631 	if (err < 0){
632 		printk("create_listening_socket at '%s' - bind failed, "
633 		       "errno = %d\n", file, errno);
634 		return(-errno);
635 	}
636 
637 	return(sock);
638 }
639 
640 void os_flush_stdout(void)
641 {
642 	fflush(stdout);
643 }
644 
645 int os_lock_file(int fd, int excl)
646 {
647 	int type = excl ? F_WRLCK : F_RDLCK;
648 	struct flock lock = ((struct flock) { .l_type	= type,
649 					      .l_whence	= SEEK_SET,
650 					      .l_start	= 0,
651 					      .l_len	= 0 } );
652 	int err, save;
653 
654 	err = fcntl(fd, F_SETLK, &lock);
655 	if(!err)
656 		goto out;
657 
658 	save = -errno;
659 	err = fcntl(fd, F_GETLK, &lock);
660 	if(err){
661 		err = -errno;
662 		goto out;
663 	}
664 
665 	printk("F_SETLK failed, file already locked by pid %d\n", lock.l_pid);
666 	err = save;
667  out:
668 	return(err);
669 }
670 
671 /*
672  * Overrides for Emacs so that we follow Linus's tabbing style.
673  * Emacs will notice this stuff at the end of the file and automatically
674  * adjust the settings for this buffer only.  This must remain at the end
675  * of the file.
676  * ---------------------------------------------------------------------------
677  * Local variables:
678  * c-file-style: "linux"
679  * End:
680  */
681