/*
* 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,
struct iovec **iov)
{
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 = 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;
return compat_import_iovec(save_addr ? READ : WRITE,
compat_ptr(msg.msg_iov), msg.msg_iovlen,
UIO_FASTIOV, iov, &kmsg->msg_iter);
}
/* 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 *)(ucmsg) - (char *)(mhdr)->msg_control)))
static inline struct compat_cmsghdr __user *cmsg_compat_nxthdr(struct msghdr *msg,
struct compat_cmsghdr __user *cmsg, int cmsg_len)
{
char __user *ptr = (char __user *)cmsg + CMSG_COMPAT_ALIGN(cmsg_len);
if ((unsigned long)(ptr + 1 - (char __user *)msg->msg_control) >
msg->msg_controllen)
return NULL;
return (struct compat_cmsghdr __user *)ptr;
}
/* There is a lot of hair here because the alignment rules (and
* thus placement) of cmsg headers and length are different for
* 32-bit apps. -DaveM
*/
int cmsghdr_from_user_compat_to_kern(struct msghdr *kmsg, struct sock *sk,
unsigned char *stackbuf, int stackbuf_size)
{
struct compat_cmsghdr __user *ucmsg;
struct cmsghdr *kcmsg, *kcmsg_base;
compat_size_t ucmlen;
__kernel_size_t kcmlen, tmp;
int err = -EFAULT;
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 -ENOBUFS;
/* Now copy them over neatly. */