// 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]), 0);
                break;
        case SYS_GETPEERNAME:
                ret = __sys_getsockname(a0, compat_ptr(a1), compat_ptr(a[2]), 1);
                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;
}