[people/ms/linux.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 __user *umsg,
			struct sockaddr __user **save_addr,
			compat_uptr_t *ptr, compat_size_t *len)
{
	struct compat_msghdr msg;
	ssize_t err;

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

	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_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;
	*ptr = msg.msg_iov;
	*len = msg.msg_iovlen;
	return 0;
}

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

	err = __get_compat_msghdr(kmsg, umsg, save_addr, &ptr, &len);
	if (err)
		return err;

	err = import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr), len,
			   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;
}
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 JA	36	int __get_compat_msghdr(struct msghdr *kmsg,
	37	struct compat_msghdr __user *umsg,
	38	struct sockaddr __user **save_addr,
	39	compat_uptr_t ptr, compat_size_t len)
1da177e4	40	{
5da028a8	41	struct compat_msghdr msg;
08adb7da	42	ssize_t err;
1da177e4	43
5da028a8	44	if (copy_from_user(&msg, umsg, sizeof(*umsg)))
1da177e4	45	return -EFAULT;
91edd096	46
5da028a8 AV	47	kmsg->msg_flags = msg.msg_flags;
	48	kmsg->msg_namelen = msg.msg_namelen;
	49
	50	if (!msg.msg_name)
91edd096 CM	51	kmsg->msg_namelen = 0;
	52
	53	if (kmsg->msg_namelen < 0)
	54	return -EINVAL;
	55
1661bf36	56	if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
db31c55a	57	kmsg->msg_namelen = sizeof(struct sockaddr_storage);
5da028a8	58
1f466e1f CH	59	kmsg->msg_control_is_user = true;
1f466e1f CH	60	kmsg->msg_control_user = compat_ptr(msg.msg_control);
5da028a8	61	kmsg->msg_controllen = msg.msg_controllen;
1da177e4	62
08adb7da	63	if (save_addr)
5da028a8	64	*save_addr = compat_ptr(msg.msg_name);
1da177e4	65
5da028a8	66	if (msg.msg_name && kmsg->msg_namelen) {
08adb7da	67	if (!save_addr) {
5da028a8	68	err = move_addr_to_kernel(compat_ptr(msg.msg_name),
08adb7da AV	69	kmsg->msg_namelen,
08adb7da AV	70	kmsg->msg_name);
e71a4783	71	if (err < 0)
1da177e4 LT	72	return err;
1da177e4 LT	73	}
40eea803	74	} else {
08adb7da AV	75	kmsg->msg_name = NULL;
08adb7da AV	76	kmsg->msg_namelen = 0;
40eea803	77	}
1da177e4	78
5da028a8	79	if (msg.msg_iovlen > UIO_MAXIOV)
08449320 AV	80	return -EMSGSIZE;
08449320 AV	81
0345f931	82	kmsg->msg_iocb = NULL;
0a384abf JA	83	*ptr = msg.msg_iov;
	84	*len = msg.msg_iovlen;
	85	return 0;
	86	}
	87
	88	int get_compat_msghdr(struct msghdr *kmsg,
	89	struct compat_msghdr __user *umsg,
	90	struct sockaddr __user **save_addr,
	91	struct iovec **iov)
	92	{
	93	compat_uptr_t ptr;
	94	compat_size_t len;
	95	ssize_t err;
	96
	97	err = __get_compat_msghdr(kmsg, umsg, save_addr, &ptr, &len);
	98	if (err)
	99	return err;
0345f931	100
89cd35c5 CH	101	err = import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr), len,
89cd35c5 CH	102	UIO_FASTIOV, iov, &kmsg->msg_iter);
87e5e6da	103	return err < 0 ? err : 0;
1da177e4 LT	104	}
	105
	106	/* Bleech... */
	107	#define CMSG_COMPAT_ALIGN(len) ALIGN((len), sizeof(s32))
	108
	109	#define CMSG_COMPAT_DATA(cmsg) \
1ff8cebf	110	((void __user )((char __user )(cmsg) + sizeof(struct compat_cmsghdr)))
1da177e4	111	#define CMSG_COMPAT_SPACE(len) \
1ff8cebf	112	(sizeof(struct compat_cmsghdr) + CMSG_COMPAT_ALIGN(len))
1da177e4	113	#define CMSG_COMPAT_LEN(len) \
1ff8cebf	114	(sizeof(struct compat_cmsghdr) + (len))
1da177e4 LT	115
	116	#define CMSG_COMPAT_FIRSTHDR(msg) \
	117	(((msg)->msg_controllen) >= sizeof(struct compat_cmsghdr) ? \
	118	(struct compat_cmsghdr __user *)((msg)->msg_control) : \
	119	(struct compat_cmsghdr __user *)NULL)
	120
	121	#define CMSG_COMPAT_OK(ucmlen, ucmsg, mhdr) \
	122	((ucmlen) >= sizeof(struct compat_cmsghdr) && \
	123	(ucmlen) <= (unsigned long) \
	124	((mhdr)->msg_controllen - \
1f466e1f	125	((char __user )(ucmsg) - (char __user )(mhdr)->msg_control_user)))
1da177e4 LT	126
	127	static inline struct compat_cmsghdr __user cmsg_compat_nxthdr(struct msghdr msg,
	128	struct compat_cmsghdr __user *cmsg, int cmsg_len)
	129	{
	130	char __user ptr = (char __user )cmsg + CMSG_COMPAT_ALIGN(cmsg_len);
	131	if ((unsigned long)(ptr + 1 - (char __user *)msg->msg_control) >
	132	msg->msg_controllen)
	133	return NULL;
	134	return (struct compat_cmsghdr __user *)ptr;
	135	}
	136
	137	/* There is a lot of hair here because the alignment rules (and
	138	* thus placement) of cmsg headers and length are different for
	139	* 32-bit apps. -DaveM
	140	*/
8920e8f9	141	int cmsghdr_from_user_compat_to_kern(struct msghdr kmsg, struct sock sk,
1da177e4 LT	142	unsigned char *stackbuf, int stackbuf_size)
	143	{
	144	struct compat_cmsghdr __user *ucmsg;
	145	struct cmsghdr kcmsg, kcmsg_base;
	146	compat_size_t ucmlen;
	147	__kernel_size_t kcmlen, tmp;
8920e8f9	148	int err = -EFAULT;
1da177e4	149
ac4340fc DM	150	BUILD_BUG_ON(sizeof(struct compat_cmsghdr) !=
	151	CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)));
	152
1da177e4 LT	153	kcmlen = 0;
	154	kcmsg_base = kcmsg = (struct cmsghdr *)stackbuf;
	155	ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
e71a4783 SH	156	while (ucmsg != NULL) {
e71a4783 SH	157	if (get_user(ucmlen, &ucmsg->cmsg_len))
1da177e4 LT	158	return -EFAULT;
	159
	160	/* Catch bogons. */
	161	if (!CMSG_COMPAT_OK(ucmlen, ucmsg, kmsg))
	162	return -EINVAL;
	163
1ff8cebf	164	tmp = ((ucmlen - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
8920e8f9	165	tmp = CMSG_ALIGN(tmp);
1da177e4 LT	166	kcmlen += tmp;
	167	ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, ucmlen);
	168	}
e71a4783	169	if (kcmlen == 0)
1da177e4 LT	170	return -EINVAL;
	171
	172	/* The kcmlen holds the 64-bit version of the control length.
	173	* It may not be modified as we do not stick it into the kmsg
	174	* until we have successfully copied over all of the data
	175	* from the user.
	176	*/
8920e8f9 AV	177	if (kcmlen > stackbuf_size)
	178	kcmsg_base = kcmsg = sock_kmalloc(sk, kcmlen, GFP_KERNEL);
	179	if (kcmsg == NULL)
49251cd0	180	return -ENOMEM;
1da177e4 LT	181
	182	/* Now copy them over neatly. */
	183	memset(kcmsg, 0, kcmlen);
	184	ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
e71a4783	185	while (ucmsg != NULL) {
547ce4cf AV	186	struct compat_cmsghdr cmsg;
547ce4cf AV	187	if (copy_from_user(&cmsg, ucmsg, sizeof(cmsg)))
8920e8f9	188	goto Efault;
547ce4cf	189	if (!CMSG_COMPAT_OK(cmsg.cmsg_len, ucmsg, kmsg))
8920e8f9	190	goto Einval;
547ce4cf	191	tmp = ((cmsg.cmsg_len - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
8920e8f9 AV	192	if ((char )kcmsg_base + kcmlen - (char )kcmsg < CMSG_ALIGN(tmp))
8920e8f9 AV	193	goto Einval;
1da177e4	194	kcmsg->cmsg_len = tmp;
547ce4cf AV	195	kcmsg->cmsg_level = cmsg.cmsg_level;
547ce4cf AV	196	kcmsg->cmsg_type = cmsg.cmsg_type;
8920e8f9	197	tmp = CMSG_ALIGN(tmp);
547ce4cf	198	if (copy_from_user(CMSG_DATA(kcmsg),
8920e8f9	199	CMSG_COMPAT_DATA(ucmsg),
547ce4cf	200	(cmsg.cmsg_len - sizeof(*ucmsg))))
8920e8f9	201	goto Efault;
1da177e4 LT	202
1da177e4 LT	203	/* Advance. */
8920e8f9	204	kcmsg = (struct cmsghdr )((char )kcmsg + tmp);
181964e6	205	ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, cmsg.cmsg_len);
1da177e4 LT	206	}
1da177e4 LT	207
c2a64bb9 MX	208	/*
	209	* check the length of messages copied in is the same as the
	210	* what we get from the first loop
	211	*/
	212	if ((char )kcmsg - (char )kcmsg_base != kcmlen)
	213	goto Einval;
	214
1da177e4 LT	215	/* Ok, looks like we made it. Hook it up and return success. */
	216	kmsg->msg_control = kcmsg_base;
	217	kmsg->msg_controllen = kcmlen;
	218	return 0;
	219
8920e8f9 AV	220	Einval:
	221	err = -EINVAL;
	222	Efault:
	223	if (kcmsg_base != (struct cmsghdr *)stackbuf)
	224	sock_kfree_s(sk, kcmsg_base, kcmlen);
	225	return err;
1da177e4 LT	226	}
	227
	228	int put_cmsg_compat(struct msghdr kmsg, int level, int type, int len, void data)
	229	{
1da177e4 LT	230	struct compat_cmsghdr __user cm = (struct compat_cmsghdr __user ) kmsg->msg_control;
1da177e4 LT	231	struct compat_cmsghdr cmhdr;
13c6ee2a DD	232	struct old_timeval32 ctv;
13c6ee2a DD	233	struct old_timespec32 cts[3];
1da177e4 LT	234	int cmlen;
1da177e4 LT	235
e71a4783	236	if (cm == NULL \|\| kmsg->msg_controllen < sizeof(*cm)) {
1da177e4 LT	237	kmsg->msg_flags \|= MSG_CTRUNC;
	238	return 0; /* XXX: return error? check spec. */
	239	}
	240
ee4fa23c	241	if (!COMPAT_USE_64BIT_TIME) {
7f1bc6e9	242	if (level == SOL_SOCKET && type == SO_TIMESTAMP_OLD) {
13c6ee2a	243	struct __kernel_old_timeval tv = (struct __kernel_old_timeval )data;
ee4fa23c L	244	ctv.tv_sec = tv->tv_sec;
	245	ctv.tv_usec = tv->tv_usec;
	246	data = &ctv;
	247	len = sizeof(ctv);
	248	}
	249	if (level == SOL_SOCKET &&
7f1bc6e9 DD	250	(type == SO_TIMESTAMPNS_OLD \|\| type == SO_TIMESTAMPING_OLD)) {
7f1bc6e9 DD	251	int count = type == SO_TIMESTAMPNS_OLD ? 1 : 3;
ee4fa23c	252	int i;
df1b4ba9	253	struct __kernel_old_timespec *ts = data;
ee4fa23c L	254	for (i = 0; i < count; i++) {
	255	cts[i].tv_sec = ts[i].tv_sec;
	256	cts[i].tv_nsec = ts[i].tv_nsec;
	257	}
	258	data = &cts;
	259	len = sizeof(cts[0]) * count;
20d49473	260	}
4768fbcb YH	261	}
4768fbcb YH	262
1da177e4	263	cmlen = CMSG_COMPAT_LEN(len);
e71a4783	264	if (kmsg->msg_controllen < cmlen) {
1da177e4 LT	265	kmsg->msg_flags \|= MSG_CTRUNC;
	266	cmlen = kmsg->msg_controllen;
	267	}
	268	cmhdr.cmsg_level = level;
	269	cmhdr.cmsg_type = type;
	270	cmhdr.cmsg_len = cmlen;
	271
e71a4783	272	if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
1da177e4	273	return -EFAULT;
e71a4783	274	if (copy_to_user(CMSG_COMPAT_DATA(cm), data, cmlen - sizeof(struct compat_cmsghdr)))
1da177e4 LT	275	return -EFAULT;
1da177e4 LT	276	cmlen = CMSG_COMPAT_SPACE(len);
1ac70e7a WY	277	if (kmsg->msg_controllen < cmlen)
1ac70e7a WY	278	cmlen = kmsg->msg_controllen;
1da177e4 LT	279	kmsg->msg_control += cmlen;
	280	kmsg->msg_controllen -= cmlen;
	281	return 0;
	282	}
	283
c0029de5	284	static int scm_max_fds_compat(struct msghdr *msg)
1da177e4	285	{
c0029de5 KC	286	if (msg->msg_controllen <= sizeof(struct compat_cmsghdr))
	287	return 0;
	288	return (msg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
	289	}
1da177e4	290
c0029de5 KC	291	void scm_detach_fds_compat(struct msghdr msg, struct scm_cookie scm)
	292	{
	293	struct compat_cmsghdr __user *cm =
	294	(struct compat_cmsghdr __user *)msg->msg_control;
	295	unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0;
	296	int fdmax = min_t(int, scm_max_fds_compat(msg), scm->fp->count);
16b89f69	297	int __user *cmsg_data = CMSG_COMPAT_DATA(cm);
c0029de5	298	int err = 0, i;
1da177e4	299
c0029de5	300	for (i = 0; i < fdmax; i++) {
66590610	301	err = receive_fd_user(scm->fp->fp[i], cmsg_data + i, o_flags);
1da177e4 LT	302	if (err < 0)
1da177e4 LT	303	break;
1da177e4 LT	304	}
	305
	306	if (i > 0) {
	307	int cmlen = CMSG_COMPAT_LEN(i * sizeof(int));
c0029de5	308
effee6a0	309	err = put_user(SOL_SOCKET, &cm->cmsg_level);
1da177e4 LT	310	if (!err)
	311	err = put_user(SCM_RIGHTS, &cm->cmsg_type);
	312	if (!err)
	313	err = put_user(cmlen, &cm->cmsg_len);
	314	if (!err) {
	315	cmlen = CMSG_COMPAT_SPACE(i * sizeof(int));
c0029de5 KC	316	if (msg->msg_controllen < cmlen)
	317	cmlen = msg->msg_controllen;
	318	msg->msg_control += cmlen;
	319	msg->msg_controllen -= cmlen;
1da177e4 LT	320	}
1da177e4 LT	321	}
c0029de5 KC	322
	323	if (i < scm->fp->count \|\| (scm->fp->count && fdmax <= 0))
	324	msg->msg_flags \|= MSG_CTRUNC;
1da177e4 LT	325
1da177e4 LT	326	/*
c0029de5 KC	327	* All of the files that fit in the message have had their usage counts
c0029de5 KC	328	* incremented, so we just free the list.
1da177e4 LT	329	*/
	330	__scm_destroy(scm);
	331	}
	332
1da177e4 LT	333	/* Argument list sizes for compat_sys_socketcall */
1da177e4 LT	334	#define AL(x) ((x) * sizeof(u32))
228e548e	335	static unsigned char nas[21] = {
c6d409cf ED	336	AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
	337	AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
	338	AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
228e548e	339	AL(4), AL(5), AL(4)
c6d409cf	340	};
1da177e4 LT	341	#undef AL
1da177e4 LT	342
6df35465 DB	343	static inline long __compat_sys_sendmsg(int fd,
	344	struct compat_msghdr __user *msg,
	345	unsigned int flags)
1da177e4	346	{
e1834a32 DB	347	return __sys_sendmsg(fd, (struct user_msghdr __user *)msg,
e1834a32 DB	348	flags \| MSG_CMSG_COMPAT, false);
1da177e4 LT	349	}
1da177e4 LT	350
6df35465 DB	351	COMPAT_SYSCALL_DEFINE3(sendmsg, int, fd, struct compat_msghdr __user *, msg,
	352	unsigned int, flags)
	353	{
	354	return __compat_sys_sendmsg(fd, msg, flags);
	355	}
	356
	357	static inline long __compat_sys_sendmmsg(int fd,
	358	struct compat_mmsghdr __user *mmsg,
	359	unsigned int vlen, unsigned int flags)
228e548e AB	360	{
228e548e AB	361	return __sys_sendmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
e1834a32	362	flags \| MSG_CMSG_COMPAT, false);
228e548e AB	363	}
228e548e AB	364
6df35465 DB	365	COMPAT_SYSCALL_DEFINE4(sendmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
	366	unsigned int, vlen, unsigned int, flags)
	367	{
	368	return __compat_sys_sendmmsg(fd, mmsg, vlen, flags);
	369	}
	370
	371	static inline long __compat_sys_recvmsg(int fd,
	372	struct compat_msghdr __user *msg,
	373	unsigned int flags)
1da177e4	374	{
e1834a32 DB	375	return __sys_recvmsg(fd, (struct user_msghdr __user *)msg,
e1834a32 DB	376	flags \| MSG_CMSG_COMPAT, false);
1da177e4 LT	377	}
1da177e4 LT	378
6df35465 DB	379	COMPAT_SYSCALL_DEFINE3(recvmsg, int, fd, struct compat_msghdr __user *, msg,
	380	unsigned int, flags)
	381	{
	382	return __compat_sys_recvmsg(fd, msg, flags);
	383	}
	384
fd4e82f5 DB	385	static inline long __compat_sys_recvfrom(int fd, void __user *buf,
	386	compat_size_t len, unsigned int flags,
	387	struct sockaddr __user *addr,
	388	int __user *addrlen)
	389	{
	390	return __sys_recvfrom(fd, buf, len, flags \| MSG_CMSG_COMPAT, addr,
	391	addrlen);
	392	}
	393
3a49a0f7	394	COMPAT_SYSCALL_DEFINE4(recv, int, fd, void __user *, buf, compat_size_t, len, unsigned int, flags)
1dacc76d	395	{
fd4e82f5	396	return __compat_sys_recvfrom(fd, buf, len, flags, NULL, NULL);
1dacc76d JB	397	}
1dacc76d JB	398
3a49a0f7 HC	399	COMPAT_SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, buf, compat_size_t, len,
	400	unsigned int, flags, struct sockaddr __user *, addr,
	401	int __user *, addrlen)
1dacc76d	402	{
fd4e82f5	403	return __compat_sys_recvfrom(fd, buf, len, flags, addr, addrlen);
1dacc76d JB	404	}
1dacc76d JB	405
e11d4284 AB	406	COMPAT_SYSCALL_DEFINE5(recvmmsg_time64, int, fd, struct compat_mmsghdr __user *, mmsg,
	407	unsigned int, vlen, unsigned int, flags,
	408	struct __kernel_timespec __user *, timeout)
a2e27255	409	{
e11d4284 AB	410	return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
e11d4284 AB	411	flags \| MSG_CMSG_COMPAT, timeout, NULL);
a2e27255 ACM	412	}
a2e27255 ACM	413
e11d4284	414	#ifdef CONFIG_COMPAT_32BIT_TIME
8dabe724	415	COMPAT_SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct compat_mmsghdr __user *, mmsg,
157b334a	416	unsigned int, vlen, unsigned int, flags,
9afc5eee	417	struct old_timespec32 __user *, timeout)
157b334a	418	{
e11d4284 AB	419	return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
e11d4284 AB	420	flags \| MSG_CMSG_COMPAT, NULL, timeout);
157b334a	421	}
e11d4284	422	#endif
157b334a	423
361d93c4	424	COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
1da177e4	425	{
62bc306e RGB	426	u32 a[AUDITSC_ARGS];
62bc306e RGB	427	unsigned int len;
1da177e4	428	u32 a0, a1;
62bc306e	429	int ret;
4768fbcb	430
228e548e	431	if (call < SYS_SOCKET \|\| call > SYS_SENDMMSG)
1da177e4	432	return -EINVAL;
62bc306e RGB	433	len = nas[call];
	434	if (len > sizeof(a))
	435	return -EINVAL;
	436
	437	if (copy_from_user(a, args, len))
1da177e4	438	return -EFAULT;
62bc306e RGB	439
	440	ret = audit_socketcall_compat(len / sizeof(a[0]), a);
	441	if (ret)
	442	return ret;
	443
1da177e4 LT	444	a0 = a[0];
1da177e4 LT	445	a1 = a[1];
4768fbcb	446
e71a4783	447	switch (call) {
1da177e4	448	case SYS_SOCKET:
9d6a15c3	449	ret = __sys_socket(a0, a1, a[2]);
1da177e4 LT	450	break;
1da177e4 LT	451	case SYS_BIND:
a87d35d8	452	ret = __sys_bind(a0, compat_ptr(a1), a[2]);
1da177e4 LT	453	break;
1da177e4 LT	454	case SYS_CONNECT:
1387c2c2	455	ret = __sys_connect(a0, compat_ptr(a1), a[2]);
1da177e4 LT	456	break;
1da177e4 LT	457	case SYS_LISTEN:
25e290ee	458	ret = __sys_listen(a0, a1);
1da177e4 LT	459	break;
1da177e4 LT	460	case SYS_ACCEPT:
4541e805	461	ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
1da177e4 LT	462	break;
1da177e4 LT	463	case SYS_GETSOCKNAME:
8882a107	464	ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
1da177e4 LT	465	break;
1da177e4 LT	466	case SYS_GETPEERNAME:
b21c8f83	467	ret = __sys_getpeername(a0, compat_ptr(a1), compat_ptr(a[2]));
1da177e4 LT	468	break;
1da177e4 LT	469	case SYS_SOCKETPAIR:
6debc8d8	470	ret = __sys_socketpair(a0, a1, a[2], compat_ptr(a[3]));
1da177e4 LT	471	break;
1da177e4 LT	472	case SYS_SEND:
f3bf896b	473	ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3], NULL, 0);
1da177e4 LT	474	break;
1da177e4 LT	475	case SYS_SENDTO:
211b634b DB	476	ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3],
211b634b DB	477	compat_ptr(a[4]), a[5]);
1da177e4 LT	478	break;
1da177e4 LT	479	case SYS_RECV:
fd4e82f5 DB	480	ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
fd4e82f5 DB	481	NULL, NULL);
1da177e4 LT	482	break;
1da177e4 LT	483	case SYS_RECVFROM:
fd4e82f5 DB	484	ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
	485	compat_ptr(a[4]),
	486	compat_ptr(a[5]));
1da177e4 LT	487	break;
1da177e4 LT	488	case SYS_SHUTDOWN:
005a1aea	489	ret = __sys_shutdown(a0, a1);
1da177e4 LT	490	break;
1da177e4 LT	491	case SYS_SETSOCKOPT:
55db9c0e	492	ret = __sys_setsockopt(a0, a1, a[2], compat_ptr(a[3]), a[4]);
1da177e4 LT	493	break;
1da177e4 LT	494	case SYS_GETSOCKOPT:
55db9c0e CH	495	ret = __sys_getsockopt(a0, a1, a[2], compat_ptr(a[3]),
55db9c0e CH	496	compat_ptr(a[4]));
1da177e4 LT	497	break;
1da177e4 LT	498	case SYS_SENDMSG:
6df35465	499	ret = __compat_sys_sendmsg(a0, compat_ptr(a1), a[2]);
1da177e4	500	break;
228e548e	501	case SYS_SENDMMSG:
6df35465	502	ret = __compat_sys_sendmmsg(a0, compat_ptr(a1), a[2], a[3]);
228e548e	503	break;
1da177e4	504	case SYS_RECVMSG:
6df35465	505	ret = __compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
1da177e4	506	break;
a2e27255	507	case SYS_RECVMMSG:
e11d4284 AB	508	ret = __sys_recvmmsg(a0, compat_ptr(a1), a[2],
	509	a[3] \| MSG_CMSG_COMPAT, NULL,
	510	compat_ptr(a[4]));
a2e27255	511	break;
de11defe	512	case SYS_ACCEPT4:
4541e805	513	ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]);
aaca0bdc	514	break;
1da177e4 LT	515	default:
	516	ret = -EINVAL;
	517	break;
	518	}
	519	return ret;
	520	}