summaryrefslogtreecommitdiff
path: root/net/compat.c
blob: d5d69fa15d07a65a26975797d654813e5f055568 (plain) (blame)
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
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
/* 
 * 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/fs.h>
#include <linux/sched.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/netfilter_ipv4/ip_tables.h>
#include <linux/security.h>

#include <net/scm.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <net/compat.h>

static inline int iov_from_user_compat_to_kern(struct iovec *kiov,
					  struct compat_iovec __user *uiov32,
					  int niov)
{
	int tot_len = 0;

	while(niov > 0) {
		compat_uptr_t buf;
		compat_size_t len;

		if(get_user(len, &uiov32->iov_len) ||
		   get_user(buf, &uiov32->iov_base)) {
			tot_len = -EFAULT;
			break;
		}
		tot_len += len;
		kiov->iov_base = compat_ptr(buf);
		kiov->iov_len = (__kernel_size_t) len;
		uiov32++;
		kiov++;
		niov--;
	}
	return tot_len;
}

int get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg)
{
	compat_uptr_t tmp1, tmp2, tmp3;

	if (!access_ok(VERIFY_READ, umsg, sizeof(*umsg)) ||
	    __get_user(tmp1, &umsg->msg_name) ||
	    __get_user(kmsg->msg_namelen, &umsg->msg_namelen) ||
	    __get_user(tmp2, &umsg->msg_iov) ||
	    __get_user(kmsg->msg_iovlen, &umsg->msg_iovlen) ||
	    __get_user(tmp3, &umsg->msg_control) ||
	    __get_user(kmsg->msg_controllen, &umsg->msg_controllen) ||
	    __get_user(kmsg->msg_flags, &umsg->msg_flags))
		return -EFAULT;
	kmsg->msg_name = compat_ptr(tmp1);
	kmsg->msg_iov = compat_ptr(tmp2);
	kmsg->msg_control = compat_ptr(tmp3);
	return 0;
}

/* I've named the args so it is easy to tell whose space the pointers are in. */
int verify_compat_iovec(struct msghdr *kern_msg, struct iovec *kern_iov,
		   char *kern_address, int mode)
{
	int tot_len;

	if(kern_msg->msg_namelen) {
		if(mode==VERIFY_READ) {
			int err = move_addr_to_kernel(kern_msg->msg_name,
						      kern_msg->msg_namelen,
						      kern_address);
			if(err < 0)
				return err;
		}
		kern_msg->msg_name = kern_address;
	} else
		kern_msg->msg_name = NULL;

	tot_len = iov_from_user_compat_to_kern(kern_iov,
					  (struct compat_iovec __user *)kern_msg->msg_iov,
					  kern_msg->msg_iovlen);
	if(tot_len >= 0)
		kern_msg->msg_iov = kern_iov;

	return tot_len;
}

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

#define CMSG_COMPAT_DATA(cmsg)				\
	((void __user *)((char __user *)(cmsg) + CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr))))
#define CMSG_COMPAT_SPACE(len)				\
	(CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)) + CMSG_COMPAT_ALIGN(len))
#define CMSG_COMPAT_LEN(len)				\
	(CMSG_COMPAT_ALIGN(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 *)(ucmsg) - (char *)(mhdr)->msg_control)))

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;

	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 - CMSG_COMPAT_ALIGN(sizeof(*ucmsg))) +
		       CMSG_ALIGN(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 -ENOBUFS;

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

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

	/* 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_timeval ctv;
	struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
	struct compat_cmsghdr cmhdr;
	int cmlen;

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

	if (level == SOL_SOCKET && type == SO_TIMESTAMP) { 
		struct timeval *tv = (struct timeval *)data;
		ctv.tv_sec = tv->tv_sec;
		ctv.tv_usec = tv->tv_usec;
		data = &ctv;
		len = sizeof(struct compat_timeval);
	} 
	
	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);
	kmsg->msg_control += cmlen;
	kmsg->msg_controllen -= cmlen;
	return 0;
}

void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm)
{
	struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
	int fdmax = (kmsg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
	int fdnum = scm->fp->count;
	struct file **fp = scm->fp->fp;
	int __user *cmfptr;
	int err = 0, i;

	if (fdnum < fdmax)
		fdmax = fdnum;

	for (i = 0, cmfptr = (int __user *) CMSG_COMPAT_DATA(cm); i < fdmax; i++, cmfptr++) {
		int new_fd;
		err = security_file_receive(fp[i]);
		if (err)
			break;
		err = get_unused_fd();
		if (err < 0)
			break;
		new_fd = err;
		err = put_user(new_fd, cmfptr);
		if (err) {
			put_unused_fd(new_fd);
			break;
		}
		/* Bump the usage count and install the file. */
		get_file(fp[i]);
		fd_install(new_fd, fp[i]);
	}

	if (i > 0) {
		int cmlen = CMSG_COMPAT_LEN(i * sizeof(int));
		if (!err)
			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));
			kmsg->msg_control += cmlen;
			kmsg->msg_controllen -= cmlen;
		}
	}
	if (i < fdnum)
		kmsg->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);
}

/*
 * For now, we assume that the compatibility and native version
 * of struct ipt_entry are the same - sfr.  FIXME
 */
struct compat_ipt_replace {
	char			name[IPT_TABLE_MAXNAMELEN];
	u32			valid_hooks;
	u32			num_entries;
	u32			size;
	u32			hook_entry[NF_IP_NUMHOOKS];
	u32			underflow[NF_IP_NUMHOOKS];
	u32			num_counters;
	compat_uptr_t		counters;	/* struct ipt_counters * */
	struct ipt_entry	entries[0];
};

static int do_netfilter_replace(int fd, int level, int optname,
				char __user *optval, int optlen)
{
	struct compat_ipt_replace __user *urepl;
	struct ipt_replace __user *repl_nat;
	char name[IPT_TABLE_MAXNAMELEN];
	u32 origsize, tmp32, num_counters;
	unsigned int repl_nat_size;
	int ret;
	int i;
	compat_uptr_t ucntrs;

	urepl = (struct compat_ipt_replace __user *)optval;
	if (get_user(origsize, &urepl->size))
		return -EFAULT;

	/* Hack: Causes ipchains to give correct error msg --RR */
	if (optlen != sizeof(*urepl) + origsize)
		return -ENOPROTOOPT;

	/* XXX Assumes that size of ipt_entry is the same both in
	 *     native and compat environments.
	 */
	repl_nat_size = sizeof(*repl_nat) + origsize;
	repl_nat = compat_alloc_user_space(repl_nat_size);

	ret = -EFAULT;
	if (put_user(origsize, &repl_nat->size))
		goto out;

	if (!access_ok(VERIFY_READ, urepl, optlen) ||
	    !access_ok(VERIFY_WRITE, repl_nat, optlen))
		goto out;

	if (__copy_from_user(name, urepl->name, sizeof(urepl->name)) ||
	    __copy_to_user(repl_nat->name, name, sizeof(repl_nat->name)))
		goto out;

	if (__get_user(tmp32, &urepl->valid_hooks) ||
	    __put_user(tmp32, &repl_nat->valid_hooks))
		goto out;

	if (__get_user(tmp32, &urepl->num_entries) ||
	    __put_user(tmp32, &repl_nat->num_entries))
		goto out;

	if (__get_user(num_counters, &urepl->num_counters) ||
	    __put_user(num_counters, &repl_nat->num_counters))
		goto out;

	if (__get_user(ucntrs, &urepl->counters) ||
	    __put_user(compat_ptr(ucntrs), &repl_nat->counters))
		goto out;

	if (__copy_in_user(&repl_nat->entries[0],
			   &urepl->entries[0],
			   origsize))
		goto out;

	for (i = 0; i < NF_IP_NUMHOOKS; i++) {
		if (__get_user(tmp32, &urepl->hook_entry[i]) ||
		    __put_user(tmp32, &repl_nat->hook_entry[i]) ||
		    __get_user(tmp32, &urepl->underflow[i]) ||
		    __put_user(tmp32, &repl_nat->underflow[i]))
			goto out;
	}

	/*
	 * Since struct ipt_counters just contains two u_int64_t members
	 * we can just do the access_ok check here and pass the (converted)
	 * pointer into the standard syscall.  We hope that the pointer is
	 * not misaligned ...
	 */
	if (!access_ok(VERIFY_WRITE, compat_ptr(ucntrs),
		       num_counters * sizeof(struct ipt_counters)))
		goto out;


	ret = sys_setsockopt(fd, level, optname,
			     (char __user *)repl_nat, repl_nat_size);

out:
	return ret;
}

/*
 * A struct sock_filter is architecture independent.
 */
struct compat_sock_fprog {
	u16		len;
	compat_uptr_t	filter;		/* struct sock_filter * */
};

static int do_set_attach_filter(struct socket *sock, int level, int optname,
				char __user *optval, int optlen)
{
	struct compat_sock_fprog __user *fprog32 = (struct compat_sock_fprog __user *)optval;
	struct sock_fprog __user *kfprog = compat_alloc_user_space(sizeof(struct sock_fprog)); 
	compat_uptr_t ptr;
	u16 len;

	if (!access_ok(VERIFY_READ, fprog32, sizeof(*fprog32)) ||
	    !access_ok(VERIFY_WRITE, kfprog, sizeof(struct sock_fprog)) ||
	    __get_user(len, &fprog32->len) ||
	    __get_user(ptr, &fprog32->filter) ||
	    __put_user(len, &kfprog->len) ||
	    __put_user(compat_ptr(ptr), &kfprog->filter))
		return -EFAULT;

	return sock_setsockopt(sock, level, optname, (char __user *)kfprog,
			      sizeof(struct sock_fprog));
}

static int do_set_sock_timeout(struct socket *sock, int level,
		int optname, char __user *optval, int optlen)
{
	struct compat_timeval __user *up = (struct compat_timeval __user *) optval;
	struct timeval ktime;
	mm_segment_t old_fs;
	int err;

	if (optlen < sizeof(*up))
		return -EINVAL;
	if (!access_ok(VERIFY_READ, up, sizeof(*up)) ||
	    __get_user(ktime.tv_sec, &up->tv_sec) ||
	    __get_user(ktime.tv_usec, &up->tv_usec))
		return -EFAULT;
	old_fs = get_fs();
	set_fs(KERNEL_DS);
	err = sock_setsockopt(sock, level, optname, (char *) &ktime, sizeof(ktime));
	set_fs(old_fs);

	return err;
}

static int compat_sock_setsockopt(struct socket *sock, int level, int optname,
				char __user *optval, int optlen)
{
	if (optname == SO_ATTACH_FILTER)
		return do_set_attach_filter(sock, level, optname,
					    optval, optlen);
	if (optname == SO_RCVTIMEO || optname == SO_SNDTIMEO)
		return do_set_sock_timeout(sock, level, optname, optval, optlen);

	return sock_setsockopt(sock, level, optname, optval, optlen);
}

asmlinkage long compat_sys_setsockopt(int fd, int level, int optname,
				char __user *optval, int optlen)
{
	int err;
	struct socket *sock;

	if (level == SOL_IPV6 && optname == IPT_SO_SET_REPLACE)
		return do_netfilter_replace(fd, level, optname,
					    optval, optlen);

	if (optlen < 0)
		return -EINVAL;

	if ((sock = sockfd_lookup(fd, &err))!=NULL)
	{
		err = security_socket_setsockopt(sock,level,optname);
		if (err) {
			sockfd_put(sock);
			return err;
		}

		if (level == SOL_SOCKET)
			err = compat_sock_setsockopt(sock, level,
					optname, optval, optlen);
		else if (sock->ops->compat_setsockopt)
			err = sock->ops->compat_setsockopt(sock, level,
					optname, optval, optlen);
		else
			err = sock->ops->setsockopt(sock, level,
					optname, optval, optlen);
		sockfd_put(sock);
	}
	return err;
}

static int do_get_sock_timeout(struct socket *sock, int level, int optname,
		char __user *optval, int __user *optlen)
{
	struct compat_timeval __user *up;
	struct timeval ktime;
	mm_segment_t old_fs;
	int len, err;

	up = (struct compat_timeval __user *) optval;
	if (get_user(len, optlen))
		return -EFAULT;
	if (len < sizeof(*up))
		return -EINVAL;
	len = sizeof(ktime);
	old_fs = get_fs();
	set_fs(KERNEL_DS);
	err = sock_getsockopt(sock, level, optname, (char *) &ktime, &len);
	set_fs(old_fs);

	if (!err) {
		if (put_user(sizeof(*up), optlen) ||
		    !access_ok(VERIFY_WRITE, up, sizeof(*up)) ||
		    __put_user(ktime.tv_sec, &up->tv_sec) ||
		    __put_user(ktime.tv_usec, &up->tv_usec))
			err = -EFAULT;
	}
	return err;
}

static int compat_sock_getsockopt(struct socket *sock, int level, int optname,
				char __user *optval, int __user *optlen)
{
	if (optname == SO_RCVTIMEO || optname == SO_SNDTIMEO)
		return do_get_sock_timeout(sock, level, optname, optval, optlen);
	return sock_getsockopt(sock, level, optname, optval, optlen);
}

int compat_sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
{
	struct compat_timeval __user *ctv =
			(struct compat_timeval __user*) userstamp;
	int err = -ENOENT;

	if (!sock_flag(sk, SOCK_TIMESTAMP))
		sock_enable_timestamp(sk);
	if (sk->sk_stamp.tv_sec == -1)
		return err;
	if (sk->sk_stamp.tv_sec == 0)
		do_gettimeofday(&sk->sk_stamp);
	if (put_user(sk->sk_stamp.tv_sec, &ctv->tv_sec) ||
			put_user(sk->sk_stamp.tv_usec, &ctv->tv_usec))
		err = -EFAULT;
	return err;
}
EXPORT_SYMBOL(compat_sock_get_timestamp);

asmlinkage long compat_sys_getsockopt(int fd, int level, int optname,
				char __user *optval, int __user *optlen)
{
	int err;
	struct socket *sock;

	if ((sock = sockfd_lookup(fd, &err))!=NULL)
	{
		err = security_socket_getsockopt(sock, level,
							   optname);
		if (err) {
			sockfd_put(sock);
			return err;
		}

		if (level == SOL_SOCKET)
			err = compat_sock_getsockopt(sock, level,
					optname, optval, optlen);
		else if (sock->ops->compat_getsockopt)
			err = sock->ops->compat_getsockopt(sock, level,
					optname, optval, optlen);
		else
			err = sock->ops->getsockopt(sock, level,
					optname, optval, optlen);
		sockfd_put(sock);
	}
	return err;
}
/* Argument list sizes for compat_sys_socketcall */
#define AL(x) ((x) * sizeof(u32))
static unsigned char nas[18]={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)};
#undef AL

asmlinkage long compat_sys_sendmsg(int fd, struct compat_msghdr __user *msg, unsigned flags)
{
	return sys_sendmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
}

asmlinkage long compat_sys_recvmsg(int fd, struct compat_msghdr __user *msg, unsigned int flags)
{
	return sys_recvmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
}

asmlinkage long compat_sys_socketcall(int call, u32 __user *args)
{
	int ret;
	u32 a[6];
	u32 a0, a1;
				 
	if (call < SYS_SOCKET || call > SYS_RECVMSG)
		return -EINVAL;
	if (copy_from_user(a, args, nas[call]))
		return -EFAULT;
	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_accept(a0, compat_ptr(a1), compat_ptr(a[2]));
		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_send(a0, compat_ptr(a1), a[2], a[3]);
		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 = sys_recv(a0, compat_ptr(a1), a[2], a[3]);
		break;
	case SYS_RECVFROM:
		ret = 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 = compat_sys_setsockopt(a0, a1, a[2],
				compat_ptr(a[3]), a[4]);
		break;
	case SYS_GETSOCKOPT:
		ret = compat_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_RECVMSG:
		ret = compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
		break;
	default:
		ret = -EINVAL;
		break;
	}
	return ret;
}