[linux-2.6-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 ? READ : WRITE, 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;
}
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	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>
	12	* Copyright (C) 2000,2001 Andi Kleen, SuSE Labs
	13	*/
	14
	15	#include <linux/kernel.h>
	16	#include <linux/gfp.h>
	17	#include <linux/fs.h>
	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>
	25	#include <linux/security.h>
	26	#include <linux/audit.h>
	27	#include <linux/export.h>
	28
	29	#include <net/scm.h>
	30	#include <net/sock.h>
	31	#include <net/ip.h>
	32	#include <net/ipv6.h>
	33	#include <linux/uaccess.h>
	34	#include <net/compat.h>
	35
	36	int __get_compat_msghdr(struct msghdr *kmsg,
	37	struct compat_msghdr *msg,
	38	struct sockaddr __user **save_addr)
	39	{
	40	ssize_t err;
	41
	42	kmsg->msg_flags = msg->msg_flags;
	43	kmsg->msg_namelen = msg->msg_namelen;
	44
	45	if (!msg->msg_name)
	46	kmsg->msg_namelen = 0;
	47
	48	if (kmsg->msg_namelen < 0)
	49	return -EINVAL;
	50
	51	if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
	52	kmsg->msg_namelen = sizeof(struct sockaddr_storage);
	53
	54	kmsg->msg_control_is_user = true;
	55	kmsg->msg_get_inq = 0;
	56	kmsg->msg_control_user = compat_ptr(msg->msg_control);
	57	kmsg->msg_controllen = msg->msg_controllen;
	58
	59	if (save_addr)
	60	*save_addr = compat_ptr(msg->msg_name);
	61
	62	if (msg->msg_name && kmsg->msg_namelen) {
	63	if (!save_addr) {
	64	err = move_addr_to_kernel(compat_ptr(msg->msg_name),
	65	kmsg->msg_namelen,
	66	kmsg->msg_name);
	67	if (err < 0)
	68	return err;
	69	}
	70	} else {
	71	kmsg->msg_name = NULL;
	72	kmsg->msg_namelen = 0;
	73	}
	74
	75	if (msg->msg_iovlen > UIO_MAXIOV)
	76	return -EMSGSIZE;
	77
	78	kmsg->msg_iocb = NULL;
	79	kmsg->msg_ubuf = NULL;
	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	{
	88	struct compat_msghdr msg;
	89	ssize_t err;
	90
	91	if (copy_from_user(&msg, umsg, sizeof(*umsg)))
	92	return -EFAULT;
	93
	94	err = __get_compat_msghdr(kmsg, &msg, save_addr);
	95	if (err)
	96	return err;
	97
	98	err = import_iovec(save_addr ? READ : WRITE, compat_ptr(msg.msg_iov), msg.msg_iovlen,
	99	UIO_FASTIOV, iov, &kmsg->msg_iter);
	100	return err < 0 ? err : 0;
	101	}
	102
	103	/* Bleech... */
	104	#define CMSG_COMPAT_ALIGN(len) ALIGN((len), sizeof(s32))
	105
	106	#define CMSG_COMPAT_DATA(cmsg) \
	107	((void __user )((char __user )(cmsg) + sizeof(struct compat_cmsghdr)))
	108	#define CMSG_COMPAT_SPACE(len) \
	109	(sizeof(struct compat_cmsghdr) + CMSG_COMPAT_ALIGN(len))
	110	#define CMSG_COMPAT_LEN(len) \
	111	(sizeof(struct compat_cmsghdr) + (len))
	112
	113	#define CMSG_COMPAT_FIRSTHDR(msg) \
	114	(((msg)->msg_controllen) >= sizeof(struct compat_cmsghdr) ? \
	115	(struct compat_cmsghdr __user *)((msg)->msg_control) : \
	116	(struct compat_cmsghdr __user *)NULL)
	117
	118	#define CMSG_COMPAT_OK(ucmlen, ucmsg, mhdr) \
	119	((ucmlen) >= sizeof(struct compat_cmsghdr) && \
	120	(ucmlen) <= (unsigned long) \
	121	((mhdr)->msg_controllen - \
	122	((char __user )(ucmsg) - (char __user )(mhdr)->msg_control_user)))
	123
	124	static inline struct compat_cmsghdr __user cmsg_compat_nxthdr(struct msghdr msg,
	125	struct compat_cmsghdr __user *cmsg, int cmsg_len)
	126	{
	127	char __user ptr = (char __user )cmsg + CMSG_COMPAT_ALIGN(cmsg_len);
	128	if ((unsigned long)(ptr + 1 - (char __user *)msg->msg_control) >
	129	msg->msg_controllen)
	130	return NULL;
	131	return (struct compat_cmsghdr __user *)ptr;
	132	}
	133
	134	/* There is a lot of hair here because the alignment rules (and
	135	* thus placement) of cmsg headers and length are different for
	136	* 32-bit apps. -DaveM
	137	*/
	138	int cmsghdr_from_user_compat_to_kern(struct msghdr kmsg, struct sock sk,
	139	unsigned char *stackbuf, int stackbuf_size)
	140	{
	141	struct compat_cmsghdr __user *ucmsg;
	142	struct cmsghdr kcmsg, kcmsg_base;
	143	compat_size_t ucmlen;
	144	__kernel_size_t kcmlen, tmp;
	145	int err = -EFAULT;
	146
	147	BUILD_BUG_ON(sizeof(struct compat_cmsghdr) !=
	148	CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)));
	149
	150	kcmlen = 0;
	151	kcmsg_base = kcmsg = (struct cmsghdr *)stackbuf;
	152	ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
	153	while (ucmsg != NULL) {
	154	if (get_user(ucmlen, &ucmsg->cmsg_len))
	155	return -EFAULT;
	156
	157	/* Catch bogons. */
	158	if (!CMSG_COMPAT_OK(ucmlen, ucmsg, kmsg))
	159	return -EINVAL;
	160
	161	tmp = ((ucmlen - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
	162	tmp = CMSG_ALIGN(tmp);
	163	kcmlen += tmp;
	164	ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, ucmlen);
	165	}
	166	if (kcmlen == 0)
	167	return -EINVAL;
	168
	169	/* The kcmlen holds the 64-bit version of the control length.
	170	* It may not be modified as we do not stick it into the kmsg
	171	* until we have successfully copied over all of the data
	172	* from the user.
	173	*/
	174	if (kcmlen > stackbuf_size)
	175	kcmsg_base = kcmsg = sock_kmalloc(sk, kcmlen, GFP_KERNEL);
	176	if (kcmsg == NULL)
	177	return -ENOMEM;
	178
	179	/* Now copy them over neatly. */
	180	memset(kcmsg, 0, kcmlen);
	181	ucmsg = CMSG_COMPAT_FIRSTHDR(kmsg);
	182	while (ucmsg != NULL) {
	183	struct compat_cmsghdr cmsg;
	184	if (copy_from_user(&cmsg, ucmsg, sizeof(cmsg)))
	185	goto Efault;
	186	if (!CMSG_COMPAT_OK(cmsg.cmsg_len, ucmsg, kmsg))
	187	goto Einval;
	188	tmp = ((cmsg.cmsg_len - sizeof(*ucmsg)) + sizeof(struct cmsghdr));
	189	if ((char )kcmsg_base + kcmlen - (char )kcmsg < CMSG_ALIGN(tmp))
	190	goto Einval;
	191	kcmsg->cmsg_len = tmp;
	192	kcmsg->cmsg_level = cmsg.cmsg_level;
	193	kcmsg->cmsg_type = cmsg.cmsg_type;
	194	tmp = CMSG_ALIGN(tmp);
	195	if (copy_from_user(CMSG_DATA(kcmsg),
	196	CMSG_COMPAT_DATA(ucmsg),
	197	(cmsg.cmsg_len - sizeof(*ucmsg))))
	198	goto Efault;
	199
	200	/* Advance. */
	201	kcmsg = (struct cmsghdr )((char )kcmsg + tmp);
	202	ucmsg = cmsg_compat_nxthdr(kmsg, ucmsg, cmsg.cmsg_len);
	203	}
	204
	205	/*
	206	* check the length of messages copied in is the same as the
	207	* what we get from the first loop
	208	*/
	209	if ((char )kcmsg - (char )kcmsg_base != kcmlen)
	210	goto Einval;
	211
	212	/* Ok, looks like we made it. Hook it up and return success. */
	213	kmsg->msg_control = kcmsg_base;
	214	kmsg->msg_controllen = kcmlen;
	215	return 0;
	216
	217	Einval:
	218	err = -EINVAL;
	219	Efault:
	220	if (kcmsg_base != (struct cmsghdr *)stackbuf)
	221	sock_kfree_s(sk, kcmsg_base, kcmlen);
	222	return err;
	223	}
	224
	225	int put_cmsg_compat(struct msghdr kmsg, int level, int type, int len, void data)
	226	{
	227	struct compat_cmsghdr __user cm = (struct compat_cmsghdr __user ) kmsg->msg_control;
	228	struct compat_cmsghdr cmhdr;
	229	struct old_timeval32 ctv;
	230	struct old_timespec32 cts[3];
	231	int cmlen;
	232
	233	if (cm == NULL \|\| kmsg->msg_controllen < sizeof(*cm)) {
	234	kmsg->msg_flags \|= MSG_CTRUNC;
	235	return 0; /* XXX: return error? check spec. */
	236	}
	237
	238	if (!COMPAT_USE_64BIT_TIME) {
	239	if (level == SOL_SOCKET && type == SO_TIMESTAMP_OLD) {
	240	struct __kernel_old_timeval tv = (struct __kernel_old_timeval )data;
	241	ctv.tv_sec = tv->tv_sec;
	242	ctv.tv_usec = tv->tv_usec;
	243	data = &ctv;
	244	len = sizeof(ctv);
	245	}
	246	if (level == SOL_SOCKET &&
	247	(type == SO_TIMESTAMPNS_OLD \|\| type == SO_TIMESTAMPING_OLD)) {
	248	int count = type == SO_TIMESTAMPNS_OLD ? 1 : 3;
	249	int i;
	250	struct __kernel_old_timespec *ts = data;
	251	for (i = 0; i < count; i++) {
	252	cts[i].tv_sec = ts[i].tv_sec;
	253	cts[i].tv_nsec = ts[i].tv_nsec;
	254	}
	255	data = &cts;
	256	len = sizeof(cts[0]) * count;
	257	}
	258	}
	259
	260	cmlen = CMSG_COMPAT_LEN(len);
	261	if (kmsg->msg_controllen < cmlen) {
	262	kmsg->msg_flags \|= MSG_CTRUNC;
	263	cmlen = kmsg->msg_controllen;
	264	}
	265	cmhdr.cmsg_level = level;
	266	cmhdr.cmsg_type = type;
	267	cmhdr.cmsg_len = cmlen;
	268
	269	if (copy_to_user(cm, &cmhdr, sizeof cmhdr))
	270	return -EFAULT;
	271	if (copy_to_user(CMSG_COMPAT_DATA(cm), data, cmlen - sizeof(struct compat_cmsghdr)))
	272	return -EFAULT;
	273	cmlen = CMSG_COMPAT_SPACE(len);
	274	if (kmsg->msg_controllen < cmlen)
	275	cmlen = kmsg->msg_controllen;
	276	kmsg->msg_control += cmlen;
	277	kmsg->msg_controllen -= cmlen;
	278	return 0;
	279	}
	280
	281	static int scm_max_fds_compat(struct msghdr *msg)
	282	{
	283	if (msg->msg_controllen <= sizeof(struct compat_cmsghdr))
	284	return 0;
	285	return (msg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
	286	}
	287
	288	void scm_detach_fds_compat(struct msghdr msg, struct scm_cookie scm)
	289	{
	290	struct compat_cmsghdr __user *cm =
	291	(struct compat_cmsghdr __user *)msg->msg_control;
	292	unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0;
	293	int fdmax = min_t(int, scm_max_fds_compat(msg), scm->fp->count);
	294	int __user *cmsg_data = CMSG_COMPAT_DATA(cm);
	295	int err = 0, i;
	296
	297	for (i = 0; i < fdmax; i++) {
	298	err = receive_fd_user(scm->fp->fp[i], cmsg_data + i, o_flags);
	299	if (err < 0)
	300	break;
	301	}
	302
	303	if (i > 0) {
	304	int cmlen = CMSG_COMPAT_LEN(i * sizeof(int));
	305
	306	err = put_user(SOL_SOCKET, &cm->cmsg_level);
	307	if (!err)
	308	err = put_user(SCM_RIGHTS, &cm->cmsg_type);
	309	if (!err)
	310	err = put_user(cmlen, &cm->cmsg_len);
	311	if (!err) {
	312	cmlen = CMSG_COMPAT_SPACE(i * sizeof(int));
	313	if (msg->msg_controllen < cmlen)
	314	cmlen = msg->msg_controllen;
	315	msg->msg_control += cmlen;
	316	msg->msg_controllen -= cmlen;
	317	}
	318	}
	319
	320	if (i < scm->fp->count \|\| (scm->fp->count && fdmax <= 0))
	321	msg->msg_flags \|= MSG_CTRUNC;
	322
	323	/*
	324	* All of the files that fit in the message have had their usage counts
	325	* incremented, so we just free the list.
	326	*/
	327	__scm_destroy(scm);
	328	}
	329
	330	/* Argument list sizes for compat_sys_socketcall */
	331	#define AL(x) ((x) * sizeof(u32))
	332	static unsigned char nas[21] = {
	333	AL(0), AL(3), AL(3), AL(3), AL(2), AL(3),
	334	AL(3), AL(3), AL(4), AL(4), AL(4), AL(6),
	335	AL(6), AL(2), AL(5), AL(5), AL(3), AL(3),
	336	AL(4), AL(5), AL(4)
	337	};
	338	#undef AL
	339
	340	static inline long __compat_sys_sendmsg(int fd,
	341	struct compat_msghdr __user *msg,
	342	unsigned int flags)
	343	{
	344	return __sys_sendmsg(fd, (struct user_msghdr __user *)msg,
	345	flags \| MSG_CMSG_COMPAT, false);
	346	}
	347
	348	COMPAT_SYSCALL_DEFINE3(sendmsg, int, fd, struct compat_msghdr __user *, msg,
	349	unsigned int, flags)
	350	{
	351	return __compat_sys_sendmsg(fd, msg, flags);
	352	}
	353
	354	static inline long __compat_sys_sendmmsg(int fd,
	355	struct compat_mmsghdr __user *mmsg,
	356	unsigned int vlen, unsigned int flags)
	357	{
	358	return __sys_sendmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
	359	flags \| MSG_CMSG_COMPAT, false);
	360	}
	361
	362	COMPAT_SYSCALL_DEFINE4(sendmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
	363	unsigned int, vlen, unsigned int, flags)
	364	{
	365	return __compat_sys_sendmmsg(fd, mmsg, vlen, flags);
	366	}
	367
	368	static inline long __compat_sys_recvmsg(int fd,
	369	struct compat_msghdr __user *msg,
	370	unsigned int flags)
	371	{
	372	return __sys_recvmsg(fd, (struct user_msghdr __user *)msg,
	373	flags \| MSG_CMSG_COMPAT, false);
	374	}
	375
	376	COMPAT_SYSCALL_DEFINE3(recvmsg, int, fd, struct compat_msghdr __user *, msg,
	377	unsigned int, flags)
	378	{
	379	return __compat_sys_recvmsg(fd, msg, flags);
	380	}
	381
	382	static inline long __compat_sys_recvfrom(int fd, void __user *buf,
	383	compat_size_t len, unsigned int flags,
	384	struct sockaddr __user *addr,
	385	int __user *addrlen)
	386	{
	387	return __sys_recvfrom(fd, buf, len, flags \| MSG_CMSG_COMPAT, addr,
	388	addrlen);
	389	}
	390
	391	COMPAT_SYSCALL_DEFINE4(recv, int, fd, void __user *, buf, compat_size_t, len, unsigned int, flags)
	392	{
	393	return __compat_sys_recvfrom(fd, buf, len, flags, NULL, NULL);
	394	}
	395
	396	COMPAT_SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, buf, compat_size_t, len,
	397	unsigned int, flags, struct sockaddr __user *, addr,
	398	int __user *, addrlen)
	399	{
	400	return __compat_sys_recvfrom(fd, buf, len, flags, addr, addrlen);
	401	}
	402
	403	COMPAT_SYSCALL_DEFINE5(recvmmsg_time64, int, fd, struct compat_mmsghdr __user *, mmsg,
	404	unsigned int, vlen, unsigned int, flags,
	405	struct __kernel_timespec __user *, timeout)
	406	{
	407	return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
	408	flags \| MSG_CMSG_COMPAT, timeout, NULL);
	409	}
	410
	411	#ifdef CONFIG_COMPAT_32BIT_TIME
	412	COMPAT_SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct compat_mmsghdr __user *, mmsg,
	413	unsigned int, vlen, unsigned int, flags,
	414	struct old_timespec32 __user *, timeout)
	415	{
	416	return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,
	417	flags \| MSG_CMSG_COMPAT, NULL, timeout);
	418	}
	419	#endif
	420
	421	COMPAT_SYSCALL_DEFINE2(socketcall, int, call, u32 __user *, args)
	422	{
	423	u32 a[AUDITSC_ARGS];
	424	unsigned int len;
	425	u32 a0, a1;
	426	int ret;
	427
	428	if (call < SYS_SOCKET \|\| call > SYS_SENDMMSG)
	429	return -EINVAL;
	430	len = nas[call];
	431	if (len > sizeof(a))
	432	return -EINVAL;
	433
	434	if (copy_from_user(a, args, len))
	435	return -EFAULT;
	436
	437	ret = audit_socketcall_compat(len / sizeof(a[0]), a);
	438	if (ret)
	439	return ret;
	440
	441	a0 = a[0];
	442	a1 = a[1];
	443
	444	switch (call) {
	445	case SYS_SOCKET:
	446	ret = __sys_socket(a0, a1, a[2]);
	447	break;
	448	case SYS_BIND:
	449	ret = __sys_bind(a0, compat_ptr(a1), a[2]);
	450	break;
	451	case SYS_CONNECT:
	452	ret = __sys_connect(a0, compat_ptr(a1), a[2]);
	453	break;
	454	case SYS_LISTEN:
	455	ret = __sys_listen(a0, a1);
	456	break;
	457	case SYS_ACCEPT:
	458	ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), 0);
	459	break;
	460	case SYS_GETSOCKNAME:
	461	ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]));
	462	break;
	463	case SYS_GETPEERNAME:
	464	ret = __sys_getpeername(a0, compat_ptr(a1), compat_ptr(a[2]));
	465	break;
	466	case SYS_SOCKETPAIR:
	467	ret = __sys_socketpair(a0, a1, a[2], compat_ptr(a[3]));
	468	break;
	469	case SYS_SEND:
	470	ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3], NULL, 0);
	471	break;
	472	case SYS_SENDTO:
	473	ret = __sys_sendto(a0, compat_ptr(a1), a[2], a[3],
	474	compat_ptr(a[4]), a[5]);
	475	break;
	476	case SYS_RECV:
	477	ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
	478	NULL, NULL);
	479	break;
	480	case SYS_RECVFROM:
	481	ret = __compat_sys_recvfrom(a0, compat_ptr(a1), a[2], a[3],
	482	compat_ptr(a[4]),
	483	compat_ptr(a[5]));
	484	break;
	485	case SYS_SHUTDOWN:
	486	ret = __sys_shutdown(a0, a1);
	487	break;
	488	case SYS_SETSOCKOPT:
	489	ret = __sys_setsockopt(a0, a1, a[2], compat_ptr(a[3]), a[4]);
	490	break;
	491	case SYS_GETSOCKOPT:
	492	ret = __sys_getsockopt(a0, a1, a[2], compat_ptr(a[3]),
	493	compat_ptr(a[4]));
	494	break;
	495	case SYS_SENDMSG:
	496	ret = __compat_sys_sendmsg(a0, compat_ptr(a1), a[2]);
	497	break;
	498	case SYS_SENDMMSG:
	499	ret = __compat_sys_sendmmsg(a0, compat_ptr(a1), a[2], a[3]);
	500	break;
	501	case SYS_RECVMSG:
	502	ret = __compat_sys_recvmsg(a0, compat_ptr(a1), a[2]);
	503	break;
	504	case SYS_RECVMMSG:
	505	ret = __sys_recvmmsg(a0, compat_ptr(a1), a[2],
	506	a[3] \| MSG_CMSG_COMPAT, NULL,
	507	compat_ptr(a[4]));
	508	break;
	509	case SYS_ACCEPT4:
	510	ret = __sys_accept4(a0, compat_ptr(a1), compat_ptr(a[2]), a[3]);
	511	break;
	512	default:
	513	ret = -EINVAL;
	514	break;
	515	}
	516	return ret;
	517	}