xref: /linux/arch/um/os-Linux/file.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 <os.h>
17 
18 static void copy_stat(struct uml_stat *dst, const struct stat64 *src)
19 {
20 	*dst = ((struct uml_stat) {
21 		.ust_dev     = src->st_dev,     /* device */
22 		.ust_ino     = src->st_ino,     /* inode */
23 		.ust_mode    = src->st_mode,    /* protection */
24 		.ust_nlink   = src->st_nlink,   /* number of hard links */
25 		.ust_uid     = src->st_uid,     /* user ID of owner */
26 		.ust_gid     = src->st_gid,     /* group ID of owner */
27 		.ust_size    = src->st_size,    /* total size, in bytes */
28 		.ust_blksize = src->st_blksize, /* blocksize for filesys I/O */
29 		.ust_blocks  = src->st_blocks,  /* number of blocks allocated */
30 		.ust_atime   = src->st_atime,   /* time of last access */
31 		.ust_mtime   = src->st_mtime,   /* time of last modification */
32 		.ust_ctime   = src->st_ctime,   /* time of last change */
33 	});
34 }
35 
36 int os_stat_fd(const int fd, struct uml_stat *ubuf)
37 {
38 	struct stat64 sbuf;
39 	int err;
40 
41 	CATCH_EINTR(err = fstat64(fd, &sbuf));
42 	if (err < 0)
43 		return -errno;
44 
45 	if (ubuf != NULL)
46 		copy_stat(ubuf, &sbuf);
47 	return err;
48 }
49 
50 int os_stat_file(const char *file_name, struct uml_stat *ubuf)
51 {
52 	struct stat64 sbuf;
53 	int err;
54 
55 	CATCH_EINTR(err = stat64(file_name, &sbuf));
56 	if (err < 0)
57 		return -errno;
58 
59 	if (ubuf != NULL)
60 		copy_stat(ubuf, &sbuf);
61 	return err;
62 }
63 
64 int os_access(const char *file, int mode)
65 {
66 	int amode, err;
67 
68 	amode = (mode & OS_ACC_R_OK ? R_OK : 0) |
69 		(mode & OS_ACC_W_OK ? W_OK : 0) |
70 		(mode & OS_ACC_X_OK ? X_OK : 0) |
71 		(mode & OS_ACC_F_OK ? F_OK : 0);
72 
73 	err = access(file, amode);
74 	if (err < 0)
75 		return -errno;
76 
77 	return 0;
78 }
79 
80 /* FIXME? required only by hostaudio (because it passes ioctls verbatim) */
81 int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
82 {
83 	int err;
84 
85 	err = ioctl(fd, cmd, arg);
86 	if (err < 0)
87 		return -errno;
88 
89 	return err;
90 }
91 
92 /* FIXME: ensure namebuf in os_get_if_name is big enough */
93 int os_get_ifname(int fd, char* namebuf)
94 {
95 	if (ioctl(fd, SIOCGIFNAME, namebuf) < 0)
96 		return -errno;
97 
98 	return 0;
99 }
100 
101 int os_set_slip(int fd)
102 {
103 	int disc, sencap;
104 
105 	disc = N_SLIP;
106 	if (ioctl(fd, TIOCSETD, &disc) < 0)
107 		return -errno;
108 
109 	sencap = 0;
110 	if (ioctl(fd, SIOCSIFENCAP, &sencap) < 0)
111 		return -errno;
112 
113 	return 0;
114 }
115 
116 int os_mode_fd(int fd, int mode)
117 {
118 	int err;
119 
120 	CATCH_EINTR(err = fchmod(fd, mode));
121 	if (err < 0)
122 		return -errno;
123 
124 	return 0;
125 }
126 
127 int os_file_type(char *file)
128 {
129 	struct uml_stat buf;
130 	int err;
131 
132 	err = os_stat_file(file, &buf);
133 	if (err < 0)
134 		return err;
135 
136 	if (S_ISDIR(buf.ust_mode))
137 		return OS_TYPE_DIR;
138 	else if (S_ISLNK(buf.ust_mode))
139 		return OS_TYPE_SYMLINK;
140 	else if (S_ISCHR(buf.ust_mode))
141 		return OS_TYPE_CHARDEV;
142 	else if (S_ISBLK(buf.ust_mode))
143 		return OS_TYPE_BLOCKDEV;
144 	else if (S_ISFIFO(buf.ust_mode))
145 		return OS_TYPE_FIFO;
146 	else if (S_ISSOCK(buf.ust_mode))
147 		return OS_TYPE_SOCK;
148 	else return OS_TYPE_FILE;
149 }
150 
151 int os_file_mode(const char *file, struct openflags *mode_out)
152 {
153 	int err;
154 
155 	*mode_out = OPENFLAGS();
156 
157 	err = access(file, W_OK);
158 	if (err && (errno != EACCES))
159 		return -errno;
160 	else if (!err)
161 		*mode_out = of_write(*mode_out);
162 
163 	err = access(file, R_OK);
164 	if (err && (errno != EACCES))
165 		return -errno;
166 	else if (!err)
167 		*mode_out = of_read(*mode_out);
168 
169 	return err;
170 }
171 
172 int os_open_file(const char *file, struct openflags flags, int mode)
173 {
174 	int fd, err, f = 0;
175 
176 	if (flags.r && flags.w)
177 		f = O_RDWR;
178 	else if (flags.r)
179 		f = O_RDONLY;
180 	else if (flags.w)
181 		f = O_WRONLY;
182 	else f = 0;
183 
184 	if (flags.s)
185 		f |= O_SYNC;
186 	if (flags.c)
187 		f |= O_CREAT;
188 	if (flags.t)
189 		f |= O_TRUNC;
190 	if (flags.e)
191 		f |= O_EXCL;
192 	if (flags.a)
193 		f |= O_APPEND;
194 
195 	fd = open64(file, f, mode);
196 	if (fd < 0)
197 		return -errno;
198 
199 	if (flags.cl && fcntl(fd, F_SETFD, 1)) {
200 		err = -errno;
201 		close(fd);
202 		return err;
203 	}
204 
205 	return fd;
206 }
207 
208 int os_connect_socket(const char *name)
209 {
210 	struct sockaddr_un sock;
211 	int fd, err;
212 
213 	sock.sun_family = AF_UNIX;
214 	snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
215 
216 	fd = socket(AF_UNIX, SOCK_STREAM, 0);
217 	if (fd < 0) {
218 		err = -errno;
219 		goto out;
220 	}
221 
222 	err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
223 	if (err) {
224 		err = -errno;
225 		goto out_close;
226 	}
227 
228 	return fd;
229 
230 out_close:
231 	close(fd);
232 out:
233 	return err;
234 }
235 
236 void os_close_file(int fd)
237 {
238 	close(fd);
239 }
240 
241 int os_seek_file(int fd, unsigned long long offset)
242 {
243 	unsigned long long actual;
244 
245 	actual = lseek64(fd, offset, SEEK_SET);
246 	if (actual != offset)
247 		return -errno;
248 	return 0;
249 }
250 
251 int os_read_file(int fd, void *buf, int len)
252 {
253 	int n = read(fd, buf, len);
254 
255 	if (n < 0)
256 		return -errno;
257 	return n;
258 }
259 
260 int os_write_file(int fd, const void *buf, int len)
261 {
262 	int n = write(fd, (void *) buf, len);
263 
264 	if (n < 0)
265 		return -errno;
266 	return n;
267 }
268 
269 int os_sync_file(int fd)
270 {
271 	int n = fsync(fd);
272 
273 	if (n < 0)
274 		return -errno;
275 	return n;
276 }
277 
278 int os_file_size(const char *file, unsigned long long *size_out)
279 {
280 	struct uml_stat buf;
281 	int err;
282 
283 	err = os_stat_file(file, &buf);
284 	if (err < 0) {
285 		printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
286 		       -err);
287 		return err;
288 	}
289 
290 	if (S_ISBLK(buf.ust_mode)) {
291 		int fd;
292 		long blocks;
293 
294 		fd = open(file, O_RDONLY, 0);
295 		if (fd < 0) {
296 			err = -errno;
297 			printk(UM_KERN_ERR "Couldn't open \"%s\", "
298 			       "errno = %d\n", file, errno);
299 			return err;
300 		}
301 		if (ioctl(fd, BLKGETSIZE, &blocks) < 0) {
302 			err = -errno;
303 			printk(UM_KERN_ERR "Couldn't get the block size of "
304 			       "\"%s\", errno = %d\n", file, errno);
305 			close(fd);
306 			return err;
307 		}
308 		*size_out = ((long long) blocks) * 512;
309 		close(fd);
310 	}
311 	else *size_out = buf.ust_size;
312 
313 	return 0;
314 }
315 
316 int os_file_modtime(const char *file, unsigned long *modtime)
317 {
318 	struct uml_stat buf;
319 	int err;
320 
321 	err = os_stat_file(file, &buf);
322 	if (err < 0) {
323 		printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
324 		       -err);
325 		return err;
326 	}
327 
328 	*modtime = buf.ust_mtime;
329 	return 0;
330 }
331 
332 int os_set_exec_close(int fd)
333 {
334 	int err;
335 
336 	CATCH_EINTR(err = fcntl(fd, F_SETFD, FD_CLOEXEC));
337 
338 	if (err < 0)
339 		return -errno;
340 	return err;
341 }
342 
343 int os_pipe(int *fds, int stream, int close_on_exec)
344 {
345 	int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
346 
347 	err = socketpair(AF_UNIX, type, 0, fds);
348 	if (err < 0)
349 		return -errno;
350 
351 	if (!close_on_exec)
352 		return 0;
353 
354 	err = os_set_exec_close(fds[0]);
355 	if (err < 0)
356 		goto error;
357 
358 	err = os_set_exec_close(fds[1]);
359 	if (err < 0)
360 		goto error;
361 
362 	return 0;
363 
364  error:
365 	printk(UM_KERN_ERR "os_pipe : Setting FD_CLOEXEC failed, err = %d\n",
366 	       -err);
367 	close(fds[1]);
368 	close(fds[0]);
369 	return err;
370 }
371 
372 int os_set_fd_async(int fd)
373 {
374 	int err, flags;
375 
376 	flags = fcntl(fd, F_GETFL);
377 	if (flags < 0)
378 		return -errno;
379 
380 	flags |= O_ASYNC | O_NONBLOCK;
381 	if (fcntl(fd, F_SETFL, flags) < 0) {
382 		err = -errno;
383 		printk(UM_KERN_ERR "os_set_fd_async : failed to set O_ASYNC "
384 		       "and O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
385 		return err;
386 	}
387 
388 	if ((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
389 	    (fcntl(fd, F_SETOWN, os_getpid()) < 0)) {
390 		err = -errno;
391 		printk(UM_KERN_ERR "os_set_fd_async : Failed to fcntl F_SETOWN "
392 		       "(or F_SETSIG) fd %d, errno = %d\n", fd, errno);
393 		return err;
394 	}
395 
396 	return 0;
397 }
398 
399 int os_clear_fd_async(int fd)
400 {
401 	int flags;
402 
403 	flags = fcntl(fd, F_GETFL);
404 	if (flags < 0)
405 		return -errno;
406 
407 	flags &= ~(O_ASYNC | O_NONBLOCK);
408 	if (fcntl(fd, F_SETFL, flags) < 0)
409 		return -errno;
410 	return 0;
411 }
412 
413 int os_set_fd_block(int fd, int blocking)
414 {
415 	int flags;
416 
417 	flags = fcntl(fd, F_GETFL);
418 	if (flags < 0)
419 		return -errno;
420 
421 	if (blocking)
422 		flags &= ~O_NONBLOCK;
423 	else
424 		flags |= O_NONBLOCK;
425 
426 	if (fcntl(fd, F_SETFL, flags) < 0)
427 		return -errno;
428 
429 	return 0;
430 }
431 
432 int os_accept_connection(int fd)
433 {
434 	int new;
435 
436 	new = accept(fd, NULL, 0);
437 	if (new < 0)
438 		return -errno;
439 	return new;
440 }
441 
442 #ifndef SHUT_RD
443 #define SHUT_RD 0
444 #endif
445 
446 #ifndef SHUT_WR
447 #define SHUT_WR 1
448 #endif
449 
450 #ifndef SHUT_RDWR
451 #define SHUT_RDWR 2
452 #endif
453 
454 int os_shutdown_socket(int fd, int r, int w)
455 {
456 	int what, err;
457 
458 	if (r && w)
459 		what = SHUT_RDWR;
460 	else if (r)
461 		what = SHUT_RD;
462 	else if (w)
463 		what = SHUT_WR;
464 	else
465 		return -EINVAL;
466 
467 	err = shutdown(fd, what);
468 	if (err < 0)
469 		return -errno;
470 	return 0;
471 }
472 
473 int os_rcv_fd(int fd, int *helper_pid_out)
474 {
475 	int new, n;
476 	char buf[CMSG_SPACE(sizeof(new))];
477 	struct msghdr msg;
478 	struct cmsghdr *cmsg;
479 	struct iovec iov;
480 
481 	msg.msg_name = NULL;
482 	msg.msg_namelen = 0;
483 	iov = ((struct iovec) { .iov_base  = helper_pid_out,
484 				.iov_len   = sizeof(*helper_pid_out) });
485 	msg.msg_iov = &iov;
486 	msg.msg_iovlen = 1;
487 	msg.msg_control = buf;
488 	msg.msg_controllen = sizeof(buf);
489 	msg.msg_flags = 0;
490 
491 	n = recvmsg(fd, &msg, 0);
492 	if (n < 0)
493 		return -errno;
494 	else if (n != iov.iov_len)
495 		*helper_pid_out = -1;
496 
497 	cmsg = CMSG_FIRSTHDR(&msg);
498 	if (cmsg == NULL) {
499 		printk(UM_KERN_ERR "rcv_fd didn't receive anything, "
500 		       "error = %d\n", errno);
501 		return -1;
502 	}
503 	if ((cmsg->cmsg_level != SOL_SOCKET) ||
504 	    (cmsg->cmsg_type != SCM_RIGHTS)) {
505 		printk(UM_KERN_ERR "rcv_fd didn't receive a descriptor\n");
506 		return -1;
507 	}
508 
509 	new = ((int *) CMSG_DATA(cmsg))[0];
510 	return new;
511 }
512 
513 int os_create_unix_socket(const char *file, int len, int close_on_exec)
514 {
515 	struct sockaddr_un addr;
516 	int sock, err;
517 
518 	sock = socket(PF_UNIX, SOCK_DGRAM, 0);
519 	if (sock < 0)
520 		return -errno;
521 
522 	if (close_on_exec) {
523 		err = os_set_exec_close(sock);
524 		if (err < 0)
525 			printk(UM_KERN_ERR "create_unix_socket : "
526 			       "close_on_exec failed, err = %d", -err);
527 	}
528 
529 	addr.sun_family = AF_UNIX;
530 
531 	snprintf(addr.sun_path, len, "%s", file);
532 
533 	err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
534 	if (err < 0)
535 		return -errno;
536 
537 	return sock;
538 }
539 
540 void os_flush_stdout(void)
541 {
542 	fflush(stdout);
543 }
544 
545 int os_lock_file(int fd, int excl)
546 {
547 	int type = excl ? F_WRLCK : F_RDLCK;
548 	struct flock lock = ((struct flock) { .l_type	= type,
549 					      .l_whence	= SEEK_SET,
550 					      .l_start	= 0,
551 					      .l_len	= 0 } );
552 	int err, save;
553 
554 	err = fcntl(fd, F_SETLK, &lock);
555 	if (!err)
556 		goto out;
557 
558 	save = -errno;
559 	err = fcntl(fd, F_GETLK, &lock);
560 	if (err) {
561 		err = -errno;
562 		goto out;
563 	}
564 
565 	printk(UM_KERN_ERR "F_SETLK failed, file already locked by pid %d\n",
566 	       lock.l_pid);
567 	err = save;
568  out:
569 	return err;
570 }
571 
572 unsigned os_major(unsigned long long dev)
573 {
574 	return major(dev);
575 }
576 
577 unsigned os_minor(unsigned long long dev)
578 {
579 	return minor(dev);
580 }
581 
582 unsigned long long os_makedev(unsigned major, unsigned minor)
583 {
584 	return makedev(major, minor);
585 }
586