// 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 -ENOBUFS;
  
  	/* 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;
  }