summaryrefslogtreecommitdiffstats
path: root/net/compat.c
blob: 161b7bea1f6204ff9120a0c2347f6105c8975772 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
// SPDX-License-Identifier: GPL-2.0-only
/*
 * 32bit Socket syscall emulation. Based on arch/sparc64/kernel/sys_sparc32.c.
 *
 * Copyright (C) 2000		VA Linux Co
 * Copyright (C) 2000		Don Dugger <n0ano@valinux.com>
 * Copyright (C) 1999 		Arun Sharma <arun.sharma@intel.com>
 * Copyright (C) 1997,1998 	Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 * Copyright (C) 1997 		David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 2000		Hewlett-Packard Co.
 * Copyright (C) 2000		David Mosberger-Tang <davidm@hpl.hp.com>
 * Copyright (C) 2000,2001	Andi Kleen, SuSE Labs
 */

#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/file.h>
#include <linux/icmpv6.h>
#include <linux/socket.h>
#include <linux/syscalls.h>
#include <linux/filter.h>
#include <linux/compat.h>
#include <linux/security.h>
#include <linux/audit.h>
#include <linux/export.h>

#include <net/scm.h>
#include <net/sock.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <linux/uaccess.h>
#include <net/compat.h>

int __get_compat_msghdr(struct msghdr *kmsg,
			struct compat_msghdr *msg,
			struct sockaddr __user **save_addr)
{
	ssize_t err;

	kmsg->msg_flags = msg->msg_flags;
	kmsg->msg_namelen = msg->msg_namelen;

	if (!msg->msg_name)
		kmsg->msg_namelen = 0;

	if (kmsg->msg_namelen < 0)
		return -EINVAL;

	if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
		kmsg->msg_namelen = sizeof(struct sockaddr_storage);

	kmsg->msg_control_is_user = true;
	kmsg->msg_get_inq = 0;
	kmsg->msg_control_user = compat_ptr(msg->msg_control);
	kmsg->msg_controllen = msg->msg_controllen;

	if (save_addr)
		*save_addr = compat_ptr(msg->msg_name);

	if (msg->msg_name && kmsg->msg_namelen) {
		if (!save_addr) {
			err = move_addr_to_kernel(compat_ptr(msg->msg_name),
						  kmsg->msg_namelen,
						  kmsg->msg_name);
			if (err < 0)
				return err;
		}
	} else {
		kmsg->msg_name = NULL;
		kmsg->msg_namelen = 0;
	}

	if (msg->msg_iovlen > UIO_MAXIOV)
		return -EMSGSIZE;

	kmsg->msg_iocb = NULL;
	kmsg->msg_ubuf = NULL;
	return 0;
}

int get_compat_msghdr(struct msghdr *kmsg,
		      struct compat_msghdr __user *umsg,
		      struct sockaddr __user **save_addr,
		      struct iovec **iov)
{
	struct compat_msghdr msg;
	ssize_t err;

	if (copy_from_user(&msg, umsg, sizeof(*umsg)))
		return -EFAULT;

	err = __get_compat_msghdr(kmsg, &msg, save_addr);
	if (err)
		return err;

	err = import_iovec(save_addr ? ITER_DEST : ITER_SOURCE,
			   compat_ptr(msg.msg_iov), msg.msg_iovlen,
			   UIO_FASTIOV, iov, &kmsg->msg_iter);
	return err < 0 ? err : 0;
}

/* Bleech... */
#define CMSG_COMPAT_ALIGN(len)	ALIGN((len), sizeof(s32))

#define CMSG_COMPAT_DATA(cmsg)				\
	((void __user *)((char __user *)(cmsg) + sizeof(struct compat_cmsghdr)))
#define CMSG_COMPAT_SPACE(len)				\
	(sizeof(struct compat_cmsghdr) + CMSG_COMPAT_ALIGN(len))
#define CMSG_COMPAT_LEN(len)				\
	(sizeof(struct compat_cmsghdr) + (len))

#define CMSG_COMPAT_FIRSTHDR(msg)			\
	(((msg)->msg_controllen) >= sizeof(struct compat_cmsghdr) ?	\
	 (struct compat_cmsghdr __user *)((msg)->msg_control) :		\
	 (struct compat_cmsghdr __user *)NULL)

#define CMSG_COMPAT_OK(ucmlen, ucmsg, mhdr) \
	((ucmlen) >= sizeof(struct compat_cmsghdr) && \
	 (ucmlen) <= (unsigned long) \
	 ((mhdr)->msg_controllen - \
	  ((char __user *)(ucmsg) - (char __user *)(mhdr)->msg_control_user)))

static inline struct compat_cmsghdr __user *cmsg_compat_nxthdr(struct msghdr *msg,
		struct compat_cmsghdr __user *cmsg, int cmsg_len)
{
	char __user *ptr = (char __user *)cmsg + CMSG_COMPAT_ALIGN(cmsg_len);
	if ((unsigned long)(ptr + 1 - (char __user *)msg->msg_control) >
			msg->msg_controllen)
		return NULL;
	return (struct compat_cmsghdr __user *)ptr;
}

/* There is a lot of hair here because the alignment rules (and
 * thus placement) of cmsg headers and length are different for
 * 32-bit apps.  -DaveM
 */
int cmsghdr_from_user_compat_to_kern(struct msghdr *kmsg, struct sock *sk,
			       unsigned char *stackbuf, int stackbuf_size)
{
	struct compat_cmsghdr __user *ucmsg;
	struct cmsghdr *kcmsg, *kcmsg_base;
	compat_size_t ucmlen;
	__kernel_size_t kcmlen, tmp;
	int err = -EFAULT;

	BUILD_BUG_ON(sizeof(struct compat_cmsghdr) !=
		     CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)));

	kcmlen = 0;
	kcmsg_base = kcmsg = (struct cmsghdr *)stackbuf;
	ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
	while (ucmsg != NULL) {
		if (get_user(ucmlen, &ucmsg->cmsg_len))
			return -EFAULT;

		/* Catch bogons. */
		if (!CMSG_COMPAT_OK(ucmlen, ucmsg, kmsg))
			return -EINVAL;

		tmp = ((ucmlen - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
		tmp = CMSG_ALIGN(tmp);
		kcmlen += tmp;
		ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, ucmlen);
	}
	if (kcmlen == 0)
		return -EINVAL;

	/* The kcmlen holds the 64-bit version of the control length.
	 * It may not be modified as we do not stick it into the kmsg
	 * until we have successfully copied over all of the data
	 * from the user.
	 */
	if (kcmlen > stackbuf_size)
		kcmsg_base = kcmsg = sock_kmalloc(sk, kcmlen, GFP_KERNEL);
	if (kcmsg == NULL)
		return -ENOMEM;

	/* Now copy them over neatly. */
	memset(kcmsg, 0, kcmlen);
	ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
	while (ucmsg != NULL) {
		struct compat_cmsghdr cmsg;
		if (copy_from_user(&cmsg, ucmsg, sizeof(cmsg)))
			goto Efault;
		if (!CMSG_COMPAT_OK(cmsg.cmsg_len, ucmsg, kmsg))
			goto Einval;
		tmp = ((cmsg.cmsg_len - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
		if ((char *)kcmsg_base + kcmlen - (char *)kcmsg < CMSG_ALIGN(tmp))
			goto Einval;
		kcmsg->cmsg_len = tmp;
		kcmsg->cmsg_level = cmsg.cmsg_level;
		kcmsg->cmsg_type = cmsg.cmsg_type;
		tmp = CMSG_ALIGN(tmp);
		if (copy_from_user(CMSG_DATA(kcmsg),
				   CMSG_COMPAT_DATA(ucmsg),
				   (cmsg.cmsg_len - sizeof(*ucmsg))))
			goto Efault;

		/* Advance. */
		kcmsg = (struct cmsghdr *)((char *)kcmsg + tmp);
		ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, cmsg.cmsg_len);
	}

	/*
	 * check the length of messages copied in is the same as the
	 * what we get from the first loop
	 */
	if ((char *)kcmsg - (char *)kcmsg_base != kcmlen)
		goto Einval;

	/* Ok, looks like we made it.  Hook it up and return success. */
	kmsg->msg_control = kcmsg_base;
	kmsg->msg_controllen = kcmlen;
	return 0;

Einval:
	err = -EINVAL;
Efault:
	if (kcmsg_base != (struct cmsghdr *)stackbuf)
		sock_kfree_s(sk, kcmsg_base, kcmlen);
	return err;
}

int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *data)
{
	struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
	struct compat_cmsghdr cmhdr;
	struct old_timeval32 ctv;
	struct old_timespec32 cts[3];
	int cmlen;

	if (cm == NULL || kmsg->msg_controllen < sizeof(*cm)) {
		kmsg->msg_flags |= MSG_CTRUNC;
		return 0; /* XXX: return error? check spec. */
	}

	if (!COMPAT_USE_64BIT_TIME) {
		if (level == SOL_SOCKET && type == SO_TIMESTAMP_OLD) {
			struct __kernel_old_timeval *tv = (struct __kernel_old_timeval *)data;
			ctv.tv_sec = tv->tv_sec;
			ctv.tv_usec = tv->tv_usec;
			data = &ctv;
			len = sizeof(ctv);
		}
		if (level == SOL_SOCKET &&
		    (type == SO_TIMESTAMPNS_OLD || type == SO_TIMESTAMPING_OLD)) {
			int count = type == SO_TIMESTAMPNS_OLD ? 1 : 3;
			int i;
			struct __kernel_old_timespec *ts = data;
			for (i = 0; i < count; i++) {
				cts[i].tv_sec = ts[i].tv_sec;
				cts[i].tv_nsec = ts[i].tv_nsec;
			}
			data = &cts;
			len = sizeof(cts[0]) * count;
		}
	}

	cmlen = CMSG_COMPAT_LEN(len);
	if (kmsg->msg_controllen < cmlen) {
		kmsg->msg_flags |= MSG_CTRUNC;
		cmlen = kmsg->msg_controllen;
	}
	cmhdr.cmsg_level = level;
	cmhdr.cmsg_type = type;
	cmhdr.cmsg_len = cmlen;

	if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
		return -EFAULT;
	if (copy_to_user(CMSG_COMPAT_DATA(cm), data, cmlen - sizeof(struct compat_cmsghdr)))
		return -EFAULT;
	cmlen = CMSG_COMPAT_SPACE(len);
	if (kmsg->msg_controllen < cmlen)
		cmlen = kmsg->msg_controllen;
	kmsg->msg_control += cmlen;
	kmsg->msg_controllen -= cmlen;
	return 0;
}

static int scm_max_fds_compat(struct msghdr *msg)
{
	if (msg->msg_controllen <= sizeof(struct compat_cmsghdr))
		return 0;
	return (msg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
}

void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm)
{
	struct compat_cmsghdr __user *cm =
		(struct compat_cmsghdr __user *)msg->msg_control;
	unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0;
	int fdmax = min_t(int, scm_max_fds_compat(msg), scm->fp->count);
	int __user *cmsg_data = CMSG_COMPAT_DATA(cm);
	int err = 0, i;

	for (i = 0; i < fdmax; i++) {
		err = receive_fd_user(scm->fp->fp[i], cmsg_data + i, o_flags);
		if (err < 0)
			break;
	}

	if (i > 0) {
		int cmlen = CMSG_COMPAT_LEN(i * sizeof(int));

		err = put_user(SOL_SOCKET, &cm->cmsg_level);
		if (!err)
			err = put_user(SCM_RIGHTS, &cm->cmsg_type);
		if (!err)
			err = put_user(cmlen, &cm->cmsg_len);
		if (!err) {
			cmlen = CMSG_COMPAT_SPACE(i * sizeof(int));
			if (msg->msg_controllen < cmlen)
				cmlen = msg->msg_controllen;
			msg->msg_control += cmlen;
			msg->msg_controllen -= cmlen;
		}
	}

	if (i < scm->fp->count || (scm->fp->count && fdmax <= 0))
		msg->msg_flags |= MSG_CTRUNC;

	/*
	 * All of the files that fit in the message have had their usage counts
	 * incremented, so we just free the list.
	 */
	__scm_destroy(scm);
}

/* Argument list sizes for compat_sys_socketcall */
#define AL(x) ((x) * sizeof(u32))
static unsigned char nas[21] = {
	AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
	AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
	AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
	AL(4), AL(5), AL(4)
};
#undef AL

static inline long __compat_sys_sendmsg(int fd,
					struct compat_msghdr __user *msg,
					unsigned int flags)
{
	return __sys_sendmsg(fd, (struct user_msghdr __user *)msg,
			     flags | MSG_CMSG_COMPAT, false);
}

COMPAT_SYSCALL_DEFINE3(sendmsg, int, fd, struct compat_msghdr __user *, msg,
		       unsigned int, flags)
{
	return __compat_sys_sendmsg(fd, msg, flags);
}

static inline long __compat_sys_sendmmsg(int fd,
					 struct compat_mmsghdr __user *mmsg,
					 unsigned int vlen, unsigned int flags)
{
	return __sys_sendmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
			      flags | MSG_CMSG_COMPAT, false);
}

COMPAT_SYSCALL_DEFINE4(sendmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
		       unsigned int, vlen, unsigned int, flags)
{
	return __compat_sys_sendmmsg(fd, mmsg, vlen, flags);
}

static inline long __compat_sys_recvmsg(int fd,
					struct compat_msghdr __user *msg,
					unsigned int flags)
{
	return __sys_recvmsg(fd, (struct user_msghdr __user *)msg,
			     flags | MSG_CMSG_COMPAT, false);
}

COMPAT_SYSCALL_DEFINE3(recvmsg, int, fd, struct compat_msghdr __user *, msg,
		       unsigned int, flags)
{
	return __compat_sys_recvmsg(fd, msg, flags);
}

static inline long __compat_sys_recvfrom(int fd, void __user *buf,
					 compat_size_t len, unsigned int flags,
					 struct sockaddr __user *addr,
					 int __user *addrlen)
{
	return __sys_recvfrom(fd, buf, len, flags | MSG_CMSG_COMPAT, addr,
			      addrlen);
}

COMPAT_SYSCALL_DEFINE4(recv, int, fd, void __user *, buf, compat_size_t, len, unsigned int, flags)
{
	return __compat_sys_recvfrom(fd, buf, len, flags, NULL, NULL);
}

COMPAT_SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, buf, compat_size_t, len,
		       unsigned int, flags, struct sockaddr __user *, addr,
		       int __user *, addrlen)
{
	return __compat_sys_recvfrom(fd, buf, len, flags, addr, addrlen);
}

COMPAT_SYSCALL_DEFINE5(recvmmsg_time64, int, fd, struct compat_mmsghdr __user *, mmsg,
		       unsigned int, vlen, unsigned int, flags,
		       struct __kernel_timespec __user *, timeout)
{
	return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
			      flags | MSG_CMSG_COMPAT, timeout, NULL);
}

#ifdef CONFIG_COMPAT_32BIT_TIME
COMPAT_SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct compat_mmsghdr __user *, mmsg,
		       unsigned int, vlen, unsigned int, flags,
		       struct old_timespec32 __user *, timeout)
{
	return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
			      flags | MSG_CMSG_COMPAT, NULL, timeout);
}
#endif

COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
{
	u32 a[AUDITSC_ARGS];
	unsigned int len;
	u32 a0, a1;
	int ret;

	if (call < SYS_SOCKET || call > SYS_SENDMMSG)
		return -EINVAL;
	len = nas[call];
	if (len > sizeof(a))
		return -EINVAL;

	if (copy_from_user(a, args, len))
		return -EFAULT;

	ret = audit_socketcall_compat(len / sizeof(a[0]), a);
	if (ret)
		return ret;

	a0 = a[0];
	a1 = a[1];

	switch (call) {
	case SYS_SOCKET:
		ret = __sys_socket(a0, a1, a[2]);
		break;
	case SYS_BIND:
		ret = __sys_bind(a0, compat_ptr(a1), a[2]);
		break;
	case SYS_CONNECT:
		ret = __sys_connect(a0, compat_ptr(a1), a[2]);
		break;
	case SYS_LISTEN:
		ret = __sys_listen(a0, a1);
		break;
	case SYS_ACCEPT:
		ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
		break;
	case SYS_GETSOCKNAME:
		ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
		break;
	case SYS_GETPEERNAME:
		ret = __sys_getpeername(a0, compat_ptr(a1), compat_ptr(a[2]));
		break;
	case SYS_SOCKETPAIR:
		ret = __sys_socketpair(a0, a1, a[2], compat_ptr(a[3]));
		break;
	case SYS_SEND:
		ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3], NULL, 0);
		break;
	case SYS_SENDTO:
		ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3],
				   compat_ptr(a[4]), a[5]);
		break;
	case SYS_RECV:
		ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
					    NULL, NULL);
		break;
	case SYS_RECVFROM:
		ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
					    compat_ptr(a[4]),
					    compat_ptr(a[5]));
		break;
	case SYS_SHUTDOWN:
		ret = __sys_shutdown(a0, a1);
		break;
	case SYS_SETSOCKOPT:
		ret = __sys_setsockopt(a0, a1, a[2], compat_ptr(a[3]), a[4]);
		break;
	case SYS_GETSOCKOPT:
		ret = __sys_getsockopt(a0, a1, a[2], compat_ptr(a[3]),
				       compat_ptr(a[4]));
		break;
	case SYS_SENDMSG:
		ret = __compat_sys_sendmsg(a0, compat_ptr(a1), a[2]);
		break;
	case SYS_SENDMMSG:
		ret = __compat_sys_sendmmsg(a0, compat_ptr(a1), a[2], a[3]);
		break;
	case SYS_RECVMSG:
		ret = __compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
		break;
	case SYS_RECVMMSG:
		ret = __sys_recvmmsg(a0, compat_ptr(a1), a[2],
				     a[3] | MSG_CMSG_COMPAT, NULL,
				     compat_ptr(a[4]));
		break;
	case SYS_ACCEPT4:
		ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]);
		break;
	default:
		ret = -EINVAL;
		break;
	}
	return ret;
}