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
25static 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
43int 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
57int 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
71int 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) */
88int 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 */
100int os_get_ifname(int fd, char* namebuf)
101{
102	if (ioctl(fd, SIOCGIFNAME, namebuf) < 0)
103		return -errno;
104
105	return 0;
106}
107
108int 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
123int 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
134int 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
158int 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
179int 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
215int 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
237out_close:
238	close(fd);
239out:
240	return err;
241}
242
243void os_close_file(int fd)
244{
245	close(fd);
246}
247int os_fsync_file(int fd)
248{
249	if (fsync(fd) < 0)
250	    return -errno;
251	return 0;
252}
253
254int 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
264int 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
273int 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
282int 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
291int os_sync_file(int fd)
292{
293	int n = fdatasync(fd);
294
295	if (n < 0)
296		return -errno;
297	return n;
298}
299
300int 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
310int 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
348int 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
364int 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
375int 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
404int 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
431int 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
445int 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
464int 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
486int 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
505int 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
545int 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
572void os_flush_stdout(void)
573{
574	fflush(stdout);
575}
576
577int 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
604unsigned os_major(unsigned long long dev)
605{
606	return major(dev);
607}
608
609unsigned os_minor(unsigned long long dev)
610{
611	return minor(dev);
612}
613
614unsigned long long os_makedev(unsigned major, unsigned minor)
615{
616	return makedev(major, minor);
617}
618
619int 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
628int 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
637int 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
646int 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
681int 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