xref: /linux/arch/um/os-Linux/file.c (revision 8c749ce93ee69e789e46b3be98de9e0cbfcf8ed8)
1 /*
2  * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.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/ioctl.h>
12 #include <sys/mount.h>
13 #include <sys/socket.h>
14 #include <sys/stat.h>
15 #include <sys/un.h>
16 #include <sys/types.h>
17 #include <os.h>
18 
19 static void copy_stat(struct uml_stat *dst, const struct stat64 *src)
20 {
21 	*dst = ((struct uml_stat) {
22 		.ust_dev     = src->st_dev,     /* device */
23 		.ust_ino     = src->st_ino,     /* inode */
24 		.ust_mode    = src->st_mode,    /* protection */
25 		.ust_nlink   = src->st_nlink,   /* number of hard links */
26 		.ust_uid     = src->st_uid,     /* user ID of owner */
27 		.ust_gid     = src->st_gid,     /* group ID of owner */
28 		.ust_size    = src->st_size,    /* total size, in bytes */
29 		.ust_blksize = src->st_blksize, /* blocksize for filesys I/O */
30 		.ust_blocks  = src->st_blocks,  /* number of blocks allocated */
31 		.ust_atime   = src->st_atime,   /* time of last access */
32 		.ust_mtime   = src->st_mtime,   /* time of last modification */
33 		.ust_ctime   = src->st_ctime,   /* time of last change */
34 	});
35 }
36 
37 int os_stat_fd(const int fd, struct uml_stat *ubuf)
38 {
39 	struct stat64 sbuf;
40 	int err;
41 
42 	CATCH_EINTR(err = fstat64(fd, &sbuf));
43 	if (err < 0)
44 		return -errno;
45 
46 	if (ubuf != NULL)
47 		copy_stat(ubuf, &sbuf);
48 	return err;
49 }
50 
51 int os_stat_file(const char *file_name, struct uml_stat *ubuf)
52 {
53 	struct stat64 sbuf;
54 	int err;
55 
56 	CATCH_EINTR(err = stat64(file_name, &sbuf));
57 	if (err < 0)
58 		return -errno;
59 
60 	if (ubuf != NULL)
61 		copy_stat(ubuf, &sbuf);
62 	return err;
63 }
64 
65 int os_access(const char *file, int mode)
66 {
67 	int amode, err;
68 
69 	amode = (mode & OS_ACC_R_OK ? R_OK : 0) |
70 		(mode & OS_ACC_W_OK ? W_OK : 0) |
71 		(mode & OS_ACC_X_OK ? X_OK : 0) |
72 		(mode & OS_ACC_F_OK ? F_OK : 0);
73 
74 	err = access(file, amode);
75 	if (err < 0)
76 		return -errno;
77 
78 	return 0;
79 }
80 
81 /* FIXME? required only by hostaudio (because it passes ioctls verbatim) */
82 int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
83 {
84 	int err;
85 
86 	err = ioctl(fd, cmd, arg);
87 	if (err < 0)
88 		return -errno;
89 
90 	return err;
91 }
92 
93 /* FIXME: ensure namebuf in os_get_if_name is big enough */
94 int os_get_ifname(int fd, char* namebuf)
95 {
96 	if (ioctl(fd, SIOCGIFNAME, namebuf) < 0)
97 		return -errno;
98 
99 	return 0;
100 }
101 
102 int os_set_slip(int fd)
103 {
104 	int disc, sencap;
105 
106 	disc = N_SLIP;
107 	if (ioctl(fd, TIOCSETD, &disc) < 0)
108 		return -errno;
109 
110 	sencap = 0;
111 	if (ioctl(fd, SIOCSIFENCAP, &sencap) < 0)
112 		return -errno;
113 
114 	return 0;
115 }
116 
117 int os_mode_fd(int fd, int mode)
118 {
119 	int err;
120 
121 	CATCH_EINTR(err = fchmod(fd, mode));
122 	if (err < 0)
123 		return -errno;
124 
125 	return 0;
126 }
127 
128 int os_file_type(char *file)
129 {
130 	struct uml_stat buf;
131 	int err;
132 
133 	err = os_stat_file(file, &buf);
134 	if (err < 0)
135 		return err;
136 
137 	if (S_ISDIR(buf.ust_mode))
138 		return OS_TYPE_DIR;
139 	else if (S_ISLNK(buf.ust_mode))
140 		return OS_TYPE_SYMLINK;
141 	else if (S_ISCHR(buf.ust_mode))
142 		return OS_TYPE_CHARDEV;
143 	else if (S_ISBLK(buf.ust_mode))
144 		return OS_TYPE_BLOCKDEV;
145 	else if (S_ISFIFO(buf.ust_mode))
146 		return OS_TYPE_FIFO;
147 	else if (S_ISSOCK(buf.ust_mode))
148 		return OS_TYPE_SOCK;
149 	else return OS_TYPE_FILE;
150 }
151 
152 int os_file_mode(const char *file, struct openflags *mode_out)
153 {
154 	int err;
155 
156 	*mode_out = OPENFLAGS();
157 
158 	err = access(file, W_OK);
159 	if (err && (errno != EACCES))
160 		return -errno;
161 	else if (!err)
162 		*mode_out = of_write(*mode_out);
163 
164 	err = access(file, R_OK);
165 	if (err && (errno != EACCES))
166 		return -errno;
167 	else if (!err)
168 		*mode_out = of_read(*mode_out);
169 
170 	return err;
171 }
172 
173 int os_open_file(const char *file, struct openflags flags, int mode)
174 {
175 	int fd, err, f = 0;
176 
177 	if (flags.r && flags.w)
178 		f = O_RDWR;
179 	else if (flags.r)
180 		f = O_RDONLY;
181 	else if (flags.w)
182 		f = O_WRONLY;
183 	else f = 0;
184 
185 	if (flags.s)
186 		f |= O_SYNC;
187 	if (flags.c)
188 		f |= O_CREAT;
189 	if (flags.t)
190 		f |= O_TRUNC;
191 	if (flags.e)
192 		f |= O_EXCL;
193 	if (flags.a)
194 		f |= O_APPEND;
195 
196 	fd = open64(file, f, mode);
197 	if (fd < 0)
198 		return -errno;
199 
200 	if (flags.cl && fcntl(fd, F_SETFD, 1)) {
201 		err = -errno;
202 		close(fd);
203 		return err;
204 	}
205 
206 	return fd;
207 }
208 
209 int os_connect_socket(const char *name)
210 {
211 	struct sockaddr_un sock;
212 	int fd, err;
213 
214 	sock.sun_family = AF_UNIX;
215 	snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
216 
217 	fd = socket(AF_UNIX, SOCK_STREAM, 0);
218 	if (fd < 0) {
219 		err = -errno;
220 		goto out;
221 	}
222 
223 	err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
224 	if (err) {
225 		err = -errno;
226 		goto out_close;
227 	}
228 
229 	return fd;
230 
231 out_close:
232 	close(fd);
233 out:
234 	return err;
235 }
236 
237 void os_close_file(int fd)
238 {
239 	close(fd);
240 }
241 int os_fsync_file(int fd)
242 {
243 	if (fsync(fd) < 0)
244 	    return -errno;
245 	return 0;
246 }
247 
248 int os_seek_file(int fd, unsigned long long offset)
249 {
250 	unsigned long long actual;
251 
252 	actual = lseek64(fd, offset, SEEK_SET);
253 	if (actual != offset)
254 		return -errno;
255 	return 0;
256 }
257 
258 int os_read_file(int fd, void *buf, int len)
259 {
260 	int n = read(fd, buf, len);
261 
262 	if (n < 0)
263 		return -errno;
264 	return n;
265 }
266 
267 int os_pread_file(int fd, void *buf, int len, unsigned long long offset)
268 {
269 	int n = pread(fd, buf, len, offset);
270 
271 	if (n < 0)
272 		return -errno;
273 	return n;
274 }
275 
276 int os_write_file(int fd, const void *buf, int len)
277 {
278 	int n = write(fd, (void *) buf, len);
279 
280 	if (n < 0)
281 		return -errno;
282 	return n;
283 }
284 
285 int os_sync_file(int fd)
286 {
287 	int n = fsync(fd);
288 
289 	if (n < 0)
290 		return -errno;
291 	return n;
292 }
293 
294 int os_pwrite_file(int fd, const void *buf, int len, unsigned long long offset)
295 {
296 	int n = pwrite(fd, (void *) buf, len, offset);
297 
298 	if (n < 0)
299 		return -errno;
300 	return n;
301 }
302 
303 
304 int os_file_size(const char *file, unsigned long long *size_out)
305 {
306 	struct uml_stat buf;
307 	int err;
308 
309 	err = os_stat_file(file, &buf);
310 	if (err < 0) {
311 		printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
312 		       -err);
313 		return err;
314 	}
315 
316 	if (S_ISBLK(buf.ust_mode)) {
317 		int fd;
318 		long blocks;
319 
320 		fd = open(file, O_RDONLY, 0);
321 		if (fd < 0) {
322 			err = -errno;
323 			printk(UM_KERN_ERR "Couldn't open \"%s\", "
324 			       "errno = %d\n", file, errno);
325 			return err;
326 		}
327 		if (ioctl(fd, BLKGETSIZE, &blocks) < 0) {
328 			err = -errno;
329 			printk(UM_KERN_ERR "Couldn't get the block size of "
330 			       "\"%s\", errno = %d\n", file, errno);
331 			close(fd);
332 			return err;
333 		}
334 		*size_out = ((long long) blocks) * 512;
335 		close(fd);
336 	}
337 	else *size_out = buf.ust_size;
338 
339 	return 0;
340 }
341 
342 int os_file_modtime(const char *file, unsigned long *modtime)
343 {
344 	struct uml_stat buf;
345 	int err;
346 
347 	err = os_stat_file(file, &buf);
348 	if (err < 0) {
349 		printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
350 		       -err);
351 		return err;
352 	}
353 
354 	*modtime = buf.ust_mtime;
355 	return 0;
356 }
357 
358 int os_set_exec_close(int fd)
359 {
360 	int err;
361 
362 	CATCH_EINTR(err = fcntl(fd, F_SETFD, FD_CLOEXEC));
363 
364 	if (err < 0)
365 		return -errno;
366 	return err;
367 }
368 
369 int os_pipe(int *fds, int stream, int close_on_exec)
370 {
371 	int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
372 
373 	err = socketpair(AF_UNIX, type, 0, fds);
374 	if (err < 0)
375 		return -errno;
376 
377 	if (!close_on_exec)
378 		return 0;
379 
380 	err = os_set_exec_close(fds[0]);
381 	if (err < 0)
382 		goto error;
383 
384 	err = os_set_exec_close(fds[1]);
385 	if (err < 0)
386 		goto error;
387 
388 	return 0;
389 
390  error:
391 	printk(UM_KERN_ERR "os_pipe : Setting FD_CLOEXEC failed, err = %d\n",
392 	       -err);
393 	close(fds[1]);
394 	close(fds[0]);
395 	return err;
396 }
397 
398 int os_set_fd_async(int fd)
399 {
400 	int err, flags;
401 
402 	flags = fcntl(fd, F_GETFL);
403 	if (flags < 0)
404 		return -errno;
405 
406 	flags |= O_ASYNC | O_NONBLOCK;
407 	if (fcntl(fd, F_SETFL, flags) < 0) {
408 		err = -errno;
409 		printk(UM_KERN_ERR "os_set_fd_async : failed to set O_ASYNC "
410 		       "and O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
411 		return err;
412 	}
413 
414 	if ((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
415 	    (fcntl(fd, F_SETOWN, os_getpid()) < 0)) {
416 		err = -errno;
417 		printk(UM_KERN_ERR "os_set_fd_async : Failed to fcntl F_SETOWN "
418 		       "(or F_SETSIG) fd %d, errno = %d\n", fd, errno);
419 		return err;
420 	}
421 
422 	return 0;
423 }
424 
425 int os_clear_fd_async(int fd)
426 {
427 	int flags;
428 
429 	flags = fcntl(fd, F_GETFL);
430 	if (flags < 0)
431 		return -errno;
432 
433 	flags &= ~(O_ASYNC | O_NONBLOCK);
434 	if (fcntl(fd, F_SETFL, flags) < 0)
435 		return -errno;
436 	return 0;
437 }
438 
439 int os_set_fd_block(int fd, int blocking)
440 {
441 	int flags;
442 
443 	flags = fcntl(fd, F_GETFL);
444 	if (flags < 0)
445 		return -errno;
446 
447 	if (blocking)
448 		flags &= ~O_NONBLOCK;
449 	else
450 		flags |= O_NONBLOCK;
451 
452 	if (fcntl(fd, F_SETFL, flags) < 0)
453 		return -errno;
454 
455 	return 0;
456 }
457 
458 int os_accept_connection(int fd)
459 {
460 	int new;
461 
462 	new = accept(fd, NULL, 0);
463 	if (new < 0)
464 		return -errno;
465 	return new;
466 }
467 
468 #ifndef SHUT_RD
469 #define SHUT_RD 0
470 #endif
471 
472 #ifndef SHUT_WR
473 #define SHUT_WR 1
474 #endif
475 
476 #ifndef SHUT_RDWR
477 #define SHUT_RDWR 2
478 #endif
479 
480 int os_shutdown_socket(int fd, int r, int w)
481 {
482 	int what, err;
483 
484 	if (r && w)
485 		what = SHUT_RDWR;
486 	else if (r)
487 		what = SHUT_RD;
488 	else if (w)
489 		what = SHUT_WR;
490 	else
491 		return -EINVAL;
492 
493 	err = shutdown(fd, what);
494 	if (err < 0)
495 		return -errno;
496 	return 0;
497 }
498 
499 int os_rcv_fd(int fd, int *helper_pid_out)
500 {
501 	int new, n;
502 	char buf[CMSG_SPACE(sizeof(new))];
503 	struct msghdr msg;
504 	struct cmsghdr *cmsg;
505 	struct iovec iov;
506 
507 	msg.msg_name = NULL;
508 	msg.msg_namelen = 0;
509 	iov = ((struct iovec) { .iov_base  = helper_pid_out,
510 				.iov_len   = sizeof(*helper_pid_out) });
511 	msg.msg_iov = &iov;
512 	msg.msg_iovlen = 1;
513 	msg.msg_control = buf;
514 	msg.msg_controllen = sizeof(buf);
515 	msg.msg_flags = 0;
516 
517 	n = recvmsg(fd, &msg, 0);
518 	if (n < 0)
519 		return -errno;
520 	else if (n != iov.iov_len)
521 		*helper_pid_out = -1;
522 
523 	cmsg = CMSG_FIRSTHDR(&msg);
524 	if (cmsg == NULL) {
525 		printk(UM_KERN_ERR "rcv_fd didn't receive anything, "
526 		       "error = %d\n", errno);
527 		return -1;
528 	}
529 	if ((cmsg->cmsg_level != SOL_SOCKET) ||
530 	    (cmsg->cmsg_type != SCM_RIGHTS)) {
531 		printk(UM_KERN_ERR "rcv_fd didn't receive a descriptor\n");
532 		return -1;
533 	}
534 
535 	new = ((int *) CMSG_DATA(cmsg))[0];
536 	return new;
537 }
538 
539 int os_create_unix_socket(const char *file, int len, int close_on_exec)
540 {
541 	struct sockaddr_un addr;
542 	int sock, err;
543 
544 	sock = socket(PF_UNIX, SOCK_DGRAM, 0);
545 	if (sock < 0)
546 		return -errno;
547 
548 	if (close_on_exec) {
549 		err = os_set_exec_close(sock);
550 		if (err < 0)
551 			printk(UM_KERN_ERR "create_unix_socket : "
552 			       "close_on_exec failed, err = %d", -err);
553 	}
554 
555 	addr.sun_family = AF_UNIX;
556 
557 	snprintf(addr.sun_path, len, "%s", file);
558 
559 	err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
560 	if (err < 0)
561 		return -errno;
562 
563 	return sock;
564 }
565 
566 void os_flush_stdout(void)
567 {
568 	fflush(stdout);
569 }
570 
571 int os_lock_file(int fd, int excl)
572 {
573 	int type = excl ? F_WRLCK : F_RDLCK;
574 	struct flock lock = ((struct flock) { .l_type	= type,
575 					      .l_whence	= SEEK_SET,
576 					      .l_start	= 0,
577 					      .l_len	= 0 } );
578 	int err, save;
579 
580 	err = fcntl(fd, F_SETLK, &lock);
581 	if (!err)
582 		goto out;
583 
584 	save = -errno;
585 	err = fcntl(fd, F_GETLK, &lock);
586 	if (err) {
587 		err = -errno;
588 		goto out;
589 	}
590 
591 	printk(UM_KERN_ERR "F_SETLK failed, file already locked by pid %d\n",
592 	       lock.l_pid);
593 	err = save;
594  out:
595 	return err;
596 }
597 
598 unsigned os_major(unsigned long long dev)
599 {
600 	return major(dev);
601 }
602 
603 unsigned os_minor(unsigned long long dev)
604 {
605 	return minor(dev);
606 }
607 
608 unsigned long long os_makedev(unsigned major, unsigned minor)
609 {
610 	return makedev(major, minor);
611 }
612