[linux-block.git] / net / compat.c

// 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_user) :	\
	 (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_user) >
			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_is_user = false;
	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_user;
	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_user += 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_user;
	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 = scm_recv_one_fd(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_user += 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;
}
Commit	Line	Data
457c8996	1	// SPDX-License-Identifier: GPL-2.0-only
4768fbcb	2	/*
1da177e4 LT	3	* 32bit Socket syscall emulation. Based on arch/sparc64/kernel/sys_sparc32.c.
	4	*
	5	* Copyright (C) 2000 VA Linux Co
	6	* Copyright (C) 2000 Don Dugger <n0ano@valinux.com>
	7	* Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com>
	8	* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
	9	* Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
	10	* Copyright (C) 2000 Hewlett-Packard Co.
	11	* Copyright (C) 2000 David Mosberger-Tang <davidm@hpl.hp.com>
4768fbcb	12	* Copyright (C) 2000,2001 Andi Kleen, SuSE Labs
1da177e4 LT	13	*/
	14
	15	#include <linux/kernel.h>
5a0e3ad6	16	#include <linux/gfp.h>
1da177e4	17	#include <linux/fs.h>
1da177e4 LT	18	#include <linux/types.h>
	19	#include <linux/file.h>
	20	#include <linux/icmpv6.h>
	21	#include <linux/socket.h>
	22	#include <linux/syscalls.h>
	23	#include <linux/filter.h>
	24	#include <linux/compat.h>
1da177e4	25	#include <linux/security.h>
62bc306e	26	#include <linux/audit.h>
bc3b2d7f	27	#include <linux/export.h>
1da177e4 LT	28
	29	#include <net/scm.h>
	30	#include <net/sock.h>
dae50295 DS	31	#include <net/ip.h>
dae50295 DS	32	#include <net/ipv6.h>
7c0f6ba6	33	#include <linux/uaccess.h>
1da177e4 LT	34	#include <net/compat.h>
1da177e4 LT	35
0a384abf	36	int __get_compat_msghdr(struct msghdr *kmsg,
72c531f8 DY	37	struct compat_msghdr *msg,
72c531f8 DY	38	struct sockaddr __user **save_addr)
1da177e4	39	{
08adb7da	40	ssize_t err;
1da177e4	41
72c531f8 DY	42	kmsg->msg_flags = msg->msg_flags;
72c531f8 DY	43	kmsg->msg_namelen = msg->msg_namelen;
5da028a8	44
72c531f8	45	if (!msg->msg_name)
91edd096 CM	46	kmsg->msg_namelen = 0;
	47
	48	if (kmsg->msg_namelen < 0)
	49	return -EINVAL;
	50
1661bf36	51	if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
db31c55a	52	kmsg->msg_namelen = sizeof(struct sockaddr_storage);
5da028a8	53
1f466e1f	54	kmsg->msg_control_is_user = true;
d547c1b7	55	kmsg->msg_get_inq = 0;
72c531f8 DY	56	kmsg->msg_control_user = compat_ptr(msg->msg_control);
72c531f8 DY	57	kmsg->msg_controllen = msg->msg_controllen;
1da177e4	58
08adb7da	59	if (save_addr)
72c531f8	60	*save_addr = compat_ptr(msg->msg_name);
1da177e4	61
72c531f8	62	if (msg->msg_name && kmsg->msg_namelen) {
08adb7da	63	if (!save_addr) {
72c531f8	64	err = move_addr_to_kernel(compat_ptr(msg->msg_name),
08adb7da AV	65	kmsg->msg_namelen,
08adb7da AV	66	kmsg->msg_name);
e71a4783	67	if (err < 0)
1da177e4 LT	68	return err;
1da177e4 LT	69	}
40eea803	70	} else {
08adb7da AV	71	kmsg->msg_name = NULL;
08adb7da AV	72	kmsg->msg_namelen = 0;
40eea803	73	}
1da177e4	74
72c531f8	75	if (msg->msg_iovlen > UIO_MAXIOV)
08449320 AV	76	return -EMSGSIZE;
08449320 AV	77
0345f931	78	kmsg->msg_iocb = NULL;
7c701d92	79	kmsg->msg_ubuf = NULL;
0a384abf JA	80	return 0;
	81	}
	82
	83	int get_compat_msghdr(struct msghdr *kmsg,
	84	struct compat_msghdr __user *umsg,
	85	struct sockaddr __user **save_addr,
	86	struct iovec **iov)
	87	{
72c531f8	88	struct compat_msghdr msg;
0a384abf JA	89	ssize_t err;
0a384abf JA	90
72c531f8 DY	91	if (copy_from_user(&msg, umsg, sizeof(*umsg)))
	92	return -EFAULT;
	93
4f6a94d3	94	err = __get_compat_msghdr(kmsg, &msg, save_addr);
0a384abf JA	95	if (err)
0a384abf JA	96	return err;
0345f931	97
de4eda9d AV	98	err = import_iovec(save_addr ? ITER_DEST : ITER_SOURCE,
de4eda9d AV	99	compat_ptr(msg.msg_iov), msg.msg_iovlen,
89cd35c5	100	UIO_FASTIOV, iov, &kmsg->msg_iter);
87e5e6da	101	return err < 0 ? err : 0;
1da177e4 LT	102	}
	103
	104	/* Bleech... */
	105	#define CMSG_COMPAT_ALIGN(len) ALIGN((len), sizeof(s32))
	106
	107	#define CMSG_COMPAT_DATA(cmsg) \
1ff8cebf	108	((void __user )((char __user )(cmsg) + sizeof(struct compat_cmsghdr)))
1da177e4	109	#define CMSG_COMPAT_SPACE(len) \
1ff8cebf	110	(sizeof(struct compat_cmsghdr) + CMSG_COMPAT_ALIGN(len))
1da177e4	111	#define CMSG_COMPAT_LEN(len) \
1ff8cebf	112	(sizeof(struct compat_cmsghdr) + (len))
1da177e4 LT	113
	114	#define CMSG_COMPAT_FIRSTHDR(msg) \
	115	(((msg)->msg_controllen) >= sizeof(struct compat_cmsghdr) ? \
c39ef213	116	(struct compat_cmsghdr __user *)((msg)->msg_control_user) : \
1da177e4 LT	117	(struct compat_cmsghdr __user *)NULL)
	118
	119	#define CMSG_COMPAT_OK(ucmlen, ucmsg, mhdr) \
	120	((ucmlen) >= sizeof(struct compat_cmsghdr) && \
	121	(ucmlen) <= (unsigned long) \
	122	((mhdr)->msg_controllen - \
1f466e1f	123	((char __user )(ucmsg) - (char __user )(mhdr)->msg_control_user)))
1da177e4 LT	124
	125	static inline struct compat_cmsghdr __user cmsg_compat_nxthdr(struct msghdr msg,
	126	struct compat_cmsghdr __user *cmsg, int cmsg_len)
	127	{
	128	char __user ptr = (char __user )cmsg + CMSG_COMPAT_ALIGN(cmsg_len);
c39ef213	129	if ((unsigned long)(ptr + 1 - (char __user *)msg->msg_control_user) >
1da177e4 LT	130	msg->msg_controllen)
	131	return NULL;
	132	return (struct compat_cmsghdr __user *)ptr;
	133	}
	134
	135	/* There is a lot of hair here because the alignment rules (and
	136	* thus placement) of cmsg headers and length are different for
	137	* 32-bit apps. -DaveM
	138	*/
8920e8f9	139	int cmsghdr_from_user_compat_to_kern(struct msghdr kmsg, struct sock sk,
1da177e4 LT	140	unsigned char *stackbuf, int stackbuf_size)
	141	{
	142	struct compat_cmsghdr __user *ucmsg;
	143	struct cmsghdr kcmsg, kcmsg_base;
	144	compat_size_t ucmlen;
	145	__kernel_size_t kcmlen, tmp;
8920e8f9	146	int err = -EFAULT;
1da177e4	147
ac4340fc DM	148	BUILD_BUG_ON(sizeof(struct compat_cmsghdr) !=
	149	CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)));
	150
1da177e4 LT	151	kcmlen = 0;
	152	kcmsg_base = kcmsg = (struct cmsghdr *)stackbuf;
	153	ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
e71a4783 SH	154	while (ucmsg != NULL) {
e71a4783 SH	155	if (get_user(ucmlen, &ucmsg->cmsg_len))
1da177e4 LT	156	return -EFAULT;
	157
	158	/* Catch bogons. */
	159	if (!CMSG_COMPAT_OK(ucmlen, ucmsg, kmsg))
	160	return -EINVAL;
	161
1ff8cebf	162	tmp = ((ucmlen - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
8920e8f9	163	tmp = CMSG_ALIGN(tmp);
1da177e4 LT	164	kcmlen += tmp;
	165	ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, ucmlen);
	166	}
e71a4783	167	if (kcmlen == 0)
1da177e4 LT	168	return -EINVAL;
	169
	170	/* The kcmlen holds the 64-bit version of the control length.
	171	* It may not be modified as we do not stick it into the kmsg
	172	* until we have successfully copied over all of the data
	173	* from the user.
	174	*/
8920e8f9 AV	175	if (kcmlen > stackbuf_size)
	176	kcmsg_base = kcmsg = sock_kmalloc(sk, kcmlen, GFP_KERNEL);
	177	if (kcmsg == NULL)
49251cd0	178	return -ENOMEM;
1da177e4 LT	179
	180	/* Now copy them over neatly. */
	181	memset(kcmsg, 0, kcmlen);
	182	ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
e71a4783	183	while (ucmsg != NULL) {
547ce4cf AV	184	struct compat_cmsghdr cmsg;
547ce4cf AV	185	if (copy_from_user(&cmsg, ucmsg, sizeof(cmsg)))
8920e8f9	186	goto Efault;
547ce4cf	187	if (!CMSG_COMPAT_OK(cmsg.cmsg_len, ucmsg, kmsg))
8920e8f9	188	goto Einval;
547ce4cf	189	tmp = ((cmsg.cmsg_len - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
8920e8f9 AV	190	if ((char )kcmsg_base + kcmlen - (char )kcmsg < CMSG_ALIGN(tmp))
8920e8f9 AV	191	goto Einval;
1da177e4	192	kcmsg->cmsg_len = tmp;
547ce4cf AV	193	kcmsg->cmsg_level = cmsg.cmsg_level;
547ce4cf AV	194	kcmsg->cmsg_type = cmsg.cmsg_type;
8920e8f9	195	tmp = CMSG_ALIGN(tmp);
547ce4cf	196	if (copy_from_user(CMSG_DATA(kcmsg),
8920e8f9	197	CMSG_COMPAT_DATA(ucmsg),
547ce4cf	198	(cmsg.cmsg_len - sizeof(*ucmsg))))
8920e8f9	199	goto Efault;
1da177e4 LT	200
1da177e4 LT	201	/* Advance. */
8920e8f9	202	kcmsg = (struct cmsghdr )((char )kcmsg + tmp);
181964e6	203	ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, cmsg.cmsg_len);
1da177e4 LT	204	}
1da177e4 LT	205
c2a64bb9 MX	206	/*
	207	* check the length of messages copied in is the same as the
	208	* what we get from the first loop
	209	*/
	210	if ((char )kcmsg - (char )kcmsg_base != kcmlen)
	211	goto Einval;
	212
1da177e4	213	/* Ok, looks like we made it. Hook it up and return success. */
60daf8d4	214	kmsg->msg_control_is_user = false;
1da177e4 LT	215	kmsg->msg_control = kcmsg_base;
	216	kmsg->msg_controllen = kcmlen;
	217	return 0;
	218
8920e8f9 AV	219	Einval:
	220	err = -EINVAL;
	221	Efault:
	222	if (kcmsg_base != (struct cmsghdr *)stackbuf)
	223	sock_kfree_s(sk, kcmsg_base, kcmlen);
	224	return err;
1da177e4 LT	225	}
	226
	227	int put_cmsg_compat(struct msghdr kmsg, int level, int type, int len, void data)
	228	{
c39ef213	229	struct compat_cmsghdr __user cm = (struct compat_cmsghdr __user ) kmsg->msg_control_user;
1da177e4	230	struct compat_cmsghdr cmhdr;
13c6ee2a DD	231	struct old_timeval32 ctv;
13c6ee2a DD	232	struct old_timespec32 cts[3];
1da177e4 LT	233	int cmlen;
1da177e4 LT	234
e71a4783	235	if (cm == NULL \|\| kmsg->msg_controllen < sizeof(*cm)) {
1da177e4 LT	236	kmsg->msg_flags \|= MSG_CTRUNC;
	237	return 0; /* XXX: return error? check spec. */
	238	}
	239
ee4fa23c	240	if (!COMPAT_USE_64BIT_TIME) {
7f1bc6e9	241	if (level == SOL_SOCKET && type == SO_TIMESTAMP_OLD) {
13c6ee2a	242	struct __kernel_old_timeval tv = (struct __kernel_old_timeval )data;
ee4fa23c L	243	ctv.tv_sec = tv->tv_sec;
	244	ctv.tv_usec = tv->tv_usec;
	245	data = &ctv;
	246	len = sizeof(ctv);
	247	}
	248	if (level == SOL_SOCKET &&
7f1bc6e9 DD	249	(type == SO_TIMESTAMPNS_OLD \|\| type == SO_TIMESTAMPING_OLD)) {
7f1bc6e9 DD	250	int count = type == SO_TIMESTAMPNS_OLD ? 1 : 3;
ee4fa23c	251	int i;
df1b4ba9	252	struct __kernel_old_timespec *ts = data;
ee4fa23c L	253	for (i = 0; i < count; i++) {
	254	cts[i].tv_sec = ts[i].tv_sec;
	255	cts[i].tv_nsec = ts[i].tv_nsec;
	256	}
	257	data = &cts;
	258	len = sizeof(cts[0]) * count;
20d49473	259	}
4768fbcb YH	260	}
4768fbcb YH	261
1da177e4	262	cmlen = CMSG_COMPAT_LEN(len);
e71a4783	263	if (kmsg->msg_controllen < cmlen) {
1da177e4 LT	264	kmsg->msg_flags \|= MSG_CTRUNC;
	265	cmlen = kmsg->msg_controllen;
	266	}
	267	cmhdr.cmsg_level = level;
	268	cmhdr.cmsg_type = type;
	269	cmhdr.cmsg_len = cmlen;
	270
e71a4783	271	if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
1da177e4	272	return -EFAULT;
e71a4783	273	if (copy_to_user(CMSG_COMPAT_DATA(cm), data, cmlen - sizeof(struct compat_cmsghdr)))
1da177e4 LT	274	return -EFAULT;
1da177e4 LT	275	cmlen = CMSG_COMPAT_SPACE(len);
1ac70e7a WY	276	if (kmsg->msg_controllen < cmlen)
1ac70e7a WY	277	cmlen = kmsg->msg_controllen;
c39ef213	278	kmsg->msg_control_user += cmlen;
1da177e4 LT	279	kmsg->msg_controllen -= cmlen;
	280	return 0;
	281	}
	282
c0029de5	283	static int scm_max_fds_compat(struct msghdr *msg)
1da177e4	284	{
c0029de5 KC	285	if (msg->msg_controllen <= sizeof(struct compat_cmsghdr))
	286	return 0;
	287	return (msg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
	288	}
1da177e4	289
c0029de5 KC	290	void scm_detach_fds_compat(struct msghdr msg, struct scm_cookie scm)
	291	{
	292	struct compat_cmsghdr __user *cm =
c39ef213	293	(struct compat_cmsghdr __user *)msg->msg_control_user;
c0029de5 KC	294	unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0;
c0029de5 KC	295	int fdmax = min_t(int, scm_max_fds_compat(msg), scm->fp->count);
16b89f69	296	int __user *cmsg_data = CMSG_COMPAT_DATA(cm);
c0029de5	297	int err = 0, i;
1da177e4	298
c0029de5	299	for (i = 0; i < fdmax; i++) {
eac9189c	300	err = scm_recv_one_fd(scm->fp->fp[i], cmsg_data + i, o_flags);
1da177e4 LT	301	if (err < 0)
1da177e4 LT	302	break;
1da177e4 LT	303	}
	304
	305	if (i > 0) {
	306	int cmlen = CMSG_COMPAT_LEN(i * sizeof(int));
c0029de5	307
effee6a0	308	err = put_user(SOL_SOCKET, &cm->cmsg_level);
1da177e4 LT	309	if (!err)
	310	err = put_user(SCM_RIGHTS, &cm->cmsg_type);
	311	if (!err)
	312	err = put_user(cmlen, &cm->cmsg_len);
	313	if (!err) {
	314	cmlen = CMSG_COMPAT_SPACE(i * sizeof(int));
c0029de5 KC	315	if (msg->msg_controllen < cmlen)
c0029de5 KC	316	cmlen = msg->msg_controllen;
c39ef213	317	msg->msg_control_user += cmlen;
c0029de5	318	msg->msg_controllen -= cmlen;
1da177e4 LT	319	}
1da177e4 LT	320	}
c0029de5 KC	321
	322	if (i < scm->fp->count \|\| (scm->fp->count && fdmax <= 0))
	323	msg->msg_flags \|= MSG_CTRUNC;
1da177e4 LT	324
1da177e4 LT	325	/*
c0029de5 KC	326	* All of the files that fit in the message have had their usage counts
c0029de5 KC	327	* incremented, so we just free the list.
1da177e4 LT	328	*/
	329	__scm_destroy(scm);
	330	}
	331
1da177e4 LT	332	/* Argument list sizes for compat_sys_socketcall */
1da177e4 LT	333	#define AL(x) ((x) * sizeof(u32))
228e548e	334	static unsigned char nas[21] = {
c6d409cf ED	335	AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
	336	AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
	337	AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
228e548e	338	AL(4), AL(5), AL(4)
c6d409cf	339	};
1da177e4 LT	340	#undef AL
1da177e4 LT	341
6df35465 DB	342	static inline long __compat_sys_sendmsg(int fd,
	343	struct compat_msghdr __user *msg,
	344	unsigned int flags)
1da177e4	345	{
e1834a32 DB	346	return __sys_sendmsg(fd, (struct user_msghdr __user *)msg,
e1834a32 DB	347	flags \| MSG_CMSG_COMPAT, false);
1da177e4 LT	348	}
1da177e4 LT	349
6df35465 DB	350	COMPAT_SYSCALL_DEFINE3(sendmsg, int, fd, struct compat_msghdr __user *, msg,
	351	unsigned int, flags)
	352	{
	353	return __compat_sys_sendmsg(fd, msg, flags);
	354	}
	355
	356	static inline long __compat_sys_sendmmsg(int fd,
	357	struct compat_mmsghdr __user *mmsg,
	358	unsigned int vlen, unsigned int flags)
228e548e AB	359	{
228e548e AB	360	return __sys_sendmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
e1834a32	361	flags \| MSG_CMSG_COMPAT, false);
228e548e AB	362	}
228e548e AB	363
6df35465 DB	364	COMPAT_SYSCALL_DEFINE4(sendmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
	365	unsigned int, vlen, unsigned int, flags)
	366	{
	367	return __compat_sys_sendmmsg(fd, mmsg, vlen, flags);
	368	}
	369
	370	static inline long __compat_sys_recvmsg(int fd,
	371	struct compat_msghdr __user *msg,
	372	unsigned int flags)
1da177e4	373	{
e1834a32 DB	374	return __sys_recvmsg(fd, (struct user_msghdr __user *)msg,
e1834a32 DB	375	flags \| MSG_CMSG_COMPAT, false);
1da177e4 LT	376	}
1da177e4 LT	377
6df35465 DB	378	COMPAT_SYSCALL_DEFINE3(recvmsg, int, fd, struct compat_msghdr __user *, msg,
	379	unsigned int, flags)
	380	{
	381	return __compat_sys_recvmsg(fd, msg, flags);
	382	}
	383
fd4e82f5 DB	384	static inline long __compat_sys_recvfrom(int fd, void __user *buf,
	385	compat_size_t len, unsigned int flags,
	386	struct sockaddr __user *addr,
	387	int __user *addrlen)
	388	{
	389	return __sys_recvfrom(fd, buf, len, flags \| MSG_CMSG_COMPAT, addr,
	390	addrlen);
	391	}
	392
3a49a0f7	393	COMPAT_SYSCALL_DEFINE4(recv, int, fd, void __user *, buf, compat_size_t, len, unsigned int, flags)
1dacc76d	394	{
fd4e82f5	395	return __compat_sys_recvfrom(fd, buf, len, flags, NULL, NULL);
1dacc76d JB	396	}
1dacc76d JB	397
3a49a0f7 HC	398	COMPAT_SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, buf, compat_size_t, len,
	399	unsigned int, flags, struct sockaddr __user *, addr,
	400	int __user *, addrlen)
1dacc76d	401	{
fd4e82f5	402	return __compat_sys_recvfrom(fd, buf, len, flags, addr, addrlen);
1dacc76d JB	403	}
1dacc76d JB	404
e11d4284 AB	405	COMPAT_SYSCALL_DEFINE5(recvmmsg_time64, int, fd, struct compat_mmsghdr __user *, mmsg,
	406	unsigned int, vlen, unsigned int, flags,
	407	struct __kernel_timespec __user *, timeout)
a2e27255	408	{
e11d4284 AB	409	return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
e11d4284 AB	410	flags \| MSG_CMSG_COMPAT, timeout, NULL);
a2e27255 ACM	411	}
a2e27255 ACM	412
e11d4284	413	#ifdef CONFIG_COMPAT_32BIT_TIME
8dabe724	414	COMPAT_SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct compat_mmsghdr __user *, mmsg,
157b334a	415	unsigned int, vlen, unsigned int, flags,
9afc5eee	416	struct old_timespec32 __user *, timeout)
157b334a	417	{
e11d4284 AB	418	return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
e11d4284 AB	419	flags \| MSG_CMSG_COMPAT, NULL, timeout);
157b334a	420	}
e11d4284	421	#endif
157b334a	422
361d93c4	423	COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
1da177e4	424	{
62bc306e RGB	425	u32 a[AUDITSC_ARGS];
62bc306e RGB	426	unsigned int len;
1da177e4	427	u32 a0, a1;
62bc306e	428	int ret;
4768fbcb	429
228e548e	430	if (call < SYS_SOCKET \|\| call > SYS_SENDMMSG)
1da177e4	431	return -EINVAL;
62bc306e RGB	432	len = nas[call];
	433	if (len > sizeof(a))
	434	return -EINVAL;
	435
	436	if (copy_from_user(a, args, len))
1da177e4	437	return -EFAULT;
62bc306e RGB	438
	439	ret = audit_socketcall_compat(len / sizeof(a[0]), a);
	440	if (ret)
	441	return ret;
	442
1da177e4 LT	443	a0 = a[0];
1da177e4 LT	444	a1 = a[1];
4768fbcb	445
e71a4783	446	switch (call) {
1da177e4	447	case SYS_SOCKET:
9d6a15c3	448	ret = __sys_socket(a0, a1, a[2]);
1da177e4 LT	449	break;
1da177e4 LT	450	case SYS_BIND:
a87d35d8	451	ret = __sys_bind(a0, compat_ptr(a1), a[2]);
1da177e4 LT	452	break;
1da177e4 LT	453	case SYS_CONNECT:
1387c2c2	454	ret = __sys_connect(a0, compat_ptr(a1), a[2]);
1da177e4 LT	455	break;
1da177e4 LT	456	case SYS_LISTEN:
25e290ee	457	ret = __sys_listen(a0, a1);
1da177e4 LT	458	break;
1da177e4 LT	459	case SYS_ACCEPT:
4541e805	460	ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
1da177e4 LT	461	break;
1da177e4 LT	462	case SYS_GETSOCKNAME:
8882a107	463	ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
1da177e4 LT	464	break;
1da177e4 LT	465	case SYS_GETPEERNAME:
b21c8f83	466	ret = __sys_getpeername(a0, compat_ptr(a1), compat_ptr(a[2]));
1da177e4 LT	467	break;
1da177e4 LT	468	case SYS_SOCKETPAIR:
6debc8d8	469	ret = __sys_socketpair(a0, a1, a[2], compat_ptr(a[3]));
1da177e4 LT	470	break;
1da177e4 LT	471	case SYS_SEND:
f3bf896b	472	ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3], NULL, 0);
1da177e4 LT	473	break;
1da177e4 LT	474	case SYS_SENDTO:
211b634b DB	475	ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3],
211b634b DB	476	compat_ptr(a[4]), a[5]);
1da177e4 LT	477	break;
1da177e4 LT	478	case SYS_RECV:
fd4e82f5 DB	479	ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
fd4e82f5 DB	480	NULL, NULL);
1da177e4 LT	481	break;
1da177e4 LT	482	case SYS_RECVFROM:
fd4e82f5 DB	483	ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
	484	compat_ptr(a[4]),
	485	compat_ptr(a[5]));
1da177e4 LT	486	break;
1da177e4 LT	487	case SYS_SHUTDOWN:
005a1aea	488	ret = __sys_shutdown(a0, a1);
1da177e4 LT	489	break;
1da177e4 LT	490	case SYS_SETSOCKOPT:
55db9c0e	491	ret = __sys_setsockopt(a0, a1, a[2], compat_ptr(a[3]), a[4]);
1da177e4 LT	492	break;
1da177e4 LT	493	case SYS_GETSOCKOPT:
55db9c0e CH	494	ret = __sys_getsockopt(a0, a1, a[2], compat_ptr(a[3]),
55db9c0e CH	495	compat_ptr(a[4]));
1da177e4 LT	496	break;
1da177e4 LT	497	case SYS_SENDMSG:
6df35465	498	ret = __compat_sys_sendmsg(a0, compat_ptr(a1), a[2]);
1da177e4	499	break;
228e548e	500	case SYS_SENDMMSG:
6df35465	501	ret = __compat_sys_sendmmsg(a0, compat_ptr(a1), a[2], a[3]);
228e548e	502	break;
1da177e4	503	case SYS_RECVMSG:
6df35465	504	ret = __compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
1da177e4	505	break;
a2e27255	506	case SYS_RECVMMSG:
e11d4284 AB	507	ret = __sys_recvmmsg(a0, compat_ptr(a1), a[2],
	508	a[3] \| MSG_CMSG_COMPAT, NULL,
	509	compat_ptr(a[4]));
a2e27255	510	break;
de11defe	511	case SYS_ACCEPT4:
4541e805	512	ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]);
aaca0bdc	513	break;
1da177e4 LT	514	default:
	515	ret = -EINVAL;
	516	break;
	517	}
	518	return ret;
	519	}