qemu/bsd-user/bsd-file.h

/*
 *  file related system call shims and definitions
 *
 *  Copyright (c) 2013 Stacey D. Son
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#ifndef BSD_FILE_H
#define BSD_FILE_H

#include "qemu/path.h"

#define LOCK_PATH(p, arg)                   \
do {                                        \
    (p) = lock_user_string(arg);            \
    if ((p) == NULL) {                      \
        return -TARGET_EFAULT;              \
    }                                       \
} while (0)

#define UNLOCK_PATH(p, arg)     unlock_user(p, arg, 0)


extern struct iovec *lock_iovec(int type, abi_ulong target_addr, int count,
        int copy);
extern void unlock_iovec(struct iovec *vec, abi_ulong target_addr, int count,
        int copy);

int safe_open(const char *path, int flags, mode_t mode);
int safe_openat(int fd, const char *path, int flags, mode_t mode);

ssize_t safe_read(int fd, void *buf, size_t nbytes);
ssize_t safe_pread(int fd, void *buf, size_t nbytes, off_t offset);
ssize_t safe_readv(int fd, const struct iovec *iov, int iovcnt);
ssize_t safe_preadv(int fd, const struct iovec *iov, int iovcnt, off_t offset);

ssize_t safe_write(int fd, void *buf, size_t nbytes);
ssize_t safe_pwrite(int fd, void *buf, size_t nbytes, off_t offset);
ssize_t safe_writev(int fd, const struct iovec *iov, int iovcnt);
ssize_t safe_pwritev(int fd, const struct iovec *iov, int iovcnt, off_t offset);

/* read(2) */
static abi_long do_bsd_read(abi_long arg1, abi_long arg2, abi_long arg3)
{
    abi_long ret;
    void *p;

    p = lock_user(VERIFY_WRITE, arg2, arg3, 0);
    if (p == NULL) {
        return -TARGET_EFAULT;
    }
    ret = get_errno(safe_read(arg1, p, arg3));
    unlock_user(p, arg2, ret);

    return ret;
}

/* pread(2) */
static abi_long do_bsd_pread(void *cpu_env, abi_long arg1,
    abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6)
{
    abi_long ret;
    void *p;

    p = lock_user(VERIFY_WRITE, arg2, arg3, 0);
    if (p == NULL) {
        return -TARGET_EFAULT;
    }
    if (regpairs_aligned(cpu_env) != 0) {
        arg4 = arg5;
        arg5 = arg6;
    }
    ret = get_errno(safe_pread(arg1, p, arg3, target_arg64(arg4, arg5)));
    unlock_user(p, arg2, ret);

    return ret;
}

/* readv(2) */
static abi_long do_bsd_readv(abi_long arg1, abi_long arg2, abi_long arg3)
{
    abi_long ret;
    struct iovec *vec = lock_iovec(VERIFY_WRITE, arg2, arg3, 0);

    if (vec != NULL) {
        ret = get_errno(safe_readv(arg1, vec, arg3));
        unlock_iovec(vec, arg2, arg3, 1);
    } else {
        ret = -host_to_target_errno(errno);
    }

    return ret;
}

/* preadv(2) */
static abi_long do_bsd_preadv(void *cpu_env, abi_long arg1,
    abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6)
{
    abi_long ret;
    struct iovec *vec = lock_iovec(VERIFY_WRITE, arg2, arg3, 1);

    if (vec != NULL) {
        if (regpairs_aligned(cpu_env) != 0) {
            arg4 = arg5;
            arg5 = arg6;
        }
        ret = get_errno(safe_preadv(arg1, vec, arg3, target_arg64(arg4, arg5)));
        unlock_iovec(vec, arg2, arg3, 0);
    } else {
        ret = -host_to_target_errno(errno);
    }

    return ret;
}

/* write(2) */
static abi_long do_bsd_write(abi_long arg1, abi_long arg2, abi_long arg3)
{
    abi_long nbytes, ret;
    void *p;

    /* nbytes < 0 implies that it was larger than SIZE_MAX. */
    nbytes = arg3;
    if (nbytes < 0) {
        return -TARGET_EINVAL;
    }
    p = lock_user(VERIFY_READ, arg2, nbytes, 1);
    if (p == NULL) {
        return -TARGET_EFAULT;
    }
    ret = get_errno(safe_write(arg1, p, arg3));
    unlock_user(p, arg2, 0);

    return ret;
}

/* pwrite(2) */
static abi_long do_bsd_pwrite(void *cpu_env, abi_long arg1,
    abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6)
{
    abi_long ret;
    void *p;

    p = lock_user(VERIFY_READ, arg2, arg3, 1);
    if (p == NULL) {
        return -TARGET_EFAULT;
    }
    if (regpairs_aligned(cpu_env) != 0) {
        arg4 = arg5;
        arg5 = arg6;
    }
    ret = get_errno(safe_pwrite(arg1, p, arg3, target_arg64(arg4, arg5)));
    unlock_user(p, arg2, 0);

    return ret;
}

/* writev(2) */
static abi_long do_bsd_writev(abi_long arg1, abi_long arg2, abi_long arg3)
{
    abi_long ret;
    struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1);

    if (vec != NULL) {
        ret = get_errno(safe_writev(arg1, vec, arg3));
        unlock_iovec(vec, arg2, arg3, 0);
    } else {
        ret = -host_to_target_errno(errno);
    }

    return ret;
}

/* pwritev(2) */
static abi_long do_bsd_pwritev(void *cpu_env, abi_long arg1,
    abi_long arg2, abi_long arg3, abi_long arg4, abi_long arg5, abi_long arg6)
{
    abi_long ret;
    struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1);

    if (vec != NULL) {
        if (regpairs_aligned(cpu_env) != 0) {
            arg4 = arg5;
            arg5 = arg6;
        }
        ret = get_errno(safe_pwritev(arg1, vec, arg3, target_arg64(arg4, arg5)));
        unlock_iovec(vec, arg2, arg3, 0);
    } else {
        ret = -host_to_target_errno(errno);
    }

    return ret;
}

/* open(2) */
static abi_long do_bsd_open(abi_long arg1, abi_long arg2, abi_long arg3)
{
    abi_long ret;
    void *p;

    LOCK_PATH(p, arg1);
    ret = get_errno(safe_open(path(p), target_to_host_bitmask(arg2,
                fcntl_flags_tbl), arg3));
    UNLOCK_PATH(p, arg1);

    return ret;
}

/* openat(2) */
static abi_long do_bsd_openat(abi_long arg1, abi_long arg2,
        abi_long arg3, abi_long arg4)
{
    abi_long ret;
    void *p;

    LOCK_PATH(p, arg2);
    ret = get_errno(safe_openat(arg1, path(p),
                target_to_host_bitmask(arg3, fcntl_flags_tbl), arg4));
    UNLOCK_PATH(p, arg2);

    return ret;
}

/* close(2) */
static inline abi_long do_bsd_close(abi_long arg1)
{
    return get_errno(close(arg1));
}

/* fdatasync(2) */
static abi_long do_bsd_fdatasync(abi_long arg1)
{
    return get_errno(fdatasync(arg1));
}

/* fsync(2) */
static abi_long do_bsd_fsync(abi_long arg1)
{
    return get_errno(fsync(arg1));
}

/* closefrom(2) */
static abi_long do_bsd_closefrom(abi_long arg1)
{
    closefrom(arg1);  /* returns void */
    return get_errno(0);
}

/* revoke(2) */
static abi_long do_bsd_revoke(abi_long arg1)
{
    abi_long ret;
    void *p;

    LOCK_PATH(p, arg1);
    ret = get_errno(revoke(p)); /* XXX path(p)? */
    UNLOCK_PATH(p, arg1);

    return ret;
}

/* access(2) */
static abi_long do_bsd_access(abi_long arg1, abi_long arg2)
{
    abi_long ret;
    void *p;

    LOCK_PATH(p, arg1);
    ret = get_errno(access(path(p), arg2));
    UNLOCK_PATH(p, arg1);

    return ret;
}

/* eaccess(2) */
static abi_long do_bsd_eaccess(abi_long arg1, abi_long arg2)
{
    abi_long ret;
    void *p;

    LOCK_PATH(p, arg1);
    ret = get_errno(eaccess(path(p), arg2));
    UNLOCK_PATH(p, arg1);

    return ret;
}

/* faccessat(2) */
static abi_long do_bsd_faccessat(abi_long arg1, abi_long arg2,
        abi_long arg3, abi_long arg4)
{
    abi_long ret;
    void *p;

    LOCK_PATH(p, arg2);
    ret = get_errno(faccessat(arg1, p, arg3, arg4)); /* XXX path(p)? */
    UNLOCK_PATH(p, arg2);

    return ret;
}

#endif /* BSD_FILE_H */