qemu/linux-user/fd-trans.h

/*
 *  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 FD_TRANS_H
#define FD_TRANS_H

#include "qemu/lockable.h"

typedef abi_long (*TargetFdDataFunc)(void *, size_t);
typedef abi_long (*TargetFdAddrFunc)(void *, abi_ulong, socklen_t);
typedef struct TargetFdTrans {
    TargetFdDataFunc host_to_target_data;
    TargetFdDataFunc target_to_host_data;
    TargetFdAddrFunc target_to_host_addr;
} TargetFdTrans;

extern TargetFdTrans **target_fd_trans;
extern QemuMutex target_fd_trans_lock;

extern unsigned int target_fd_max;

static inline void fd_trans_init(void)
{
    qemu_mutex_init(&target_fd_trans_lock);
}

static inline TargetFdDataFunc fd_trans_target_to_host_data(int fd)
{
    if (fd < 0) {
        return NULL;
    }

    QEMU_LOCK_GUARD(&target_fd_trans_lock);
    if (fd < target_fd_max && target_fd_trans[fd]) {
        return target_fd_trans[fd]->target_to_host_data;
    }
    return NULL;
}

static inline TargetFdDataFunc fd_trans_host_to_target_data(int fd)
{
    if (fd < 0) {
        return NULL;
    }

    QEMU_LOCK_GUARD(&target_fd_trans_lock);
    if (fd < target_fd_max && target_fd_trans[fd]) {
        return target_fd_trans[fd]->host_to_target_data;
    }
    return NULL;
}

static inline TargetFdAddrFunc fd_trans_target_to_host_addr(int fd)
{
    if (fd < 0) {
        return NULL;
    }

    QEMU_LOCK_GUARD(&target_fd_trans_lock);
    if (fd < target_fd_max && target_fd_trans[fd]) {
        return target_fd_trans[fd]->target_to_host_addr;
    }
    return NULL;
}

static inline void internal_fd_trans_register_unsafe(int fd,
                                                     TargetFdTrans *trans)
{
    unsigned int oldmax;

    if (fd >= target_fd_max) {
        oldmax = target_fd_max;
        target_fd_max = ((fd >> 6) + 1) << 6; /* by slice of 64 entries */
        target_fd_trans = g_renew(TargetFdTrans *,
                                  target_fd_trans, target_fd_max);
        memset((void *)(target_fd_trans + oldmax), 0,
               (target_fd_max - oldmax) * sizeof(TargetFdTrans *));
    }
    target_fd_trans[fd] = trans;
}

static inline void fd_trans_register(int fd, TargetFdTrans *trans)
{
    QEMU_LOCK_GUARD(&target_fd_trans_lock);
    internal_fd_trans_register_unsafe(fd, trans);
}

static inline void internal_fd_trans_unregister_unsafe(int fd)
{
    if (fd >= 0 && fd < target_fd_max) {
        target_fd_trans[fd] = NULL;
    }
}

static inline void fd_trans_unregister(int fd)
{
    if (fd < 0) {
        return;
    }

    QEMU_LOCK_GUARD(&target_fd_trans_lock);
    internal_fd_trans_unregister_unsafe(fd);
}

static inline void fd_trans_dup(int oldfd, int newfd)
{
    QEMU_LOCK_GUARD(&target_fd_trans_lock);
    internal_fd_trans_unregister_unsafe(newfd);
    if (oldfd < target_fd_max && target_fd_trans[oldfd]) {
        internal_fd_trans_register_unsafe(newfd, target_fd_trans[oldfd]);
    }
}

extern TargetFdTrans target_packet_trans;
#ifdef CONFIG_RTNETLINK
extern TargetFdTrans target_netlink_route_trans;
#endif
extern TargetFdTrans target_netlink_audit_trans;
extern TargetFdTrans target_signalfd_trans;
extern TargetFdTrans target_eventfd_trans;
#if (defined(TARGET_NR_inotify_init) && defined(__NR_inotify_init)) || \
    (defined(CONFIG_INOTIFY1) && defined(TARGET_NR_inotify_init1) && \
     defined(__NR_inotify_init1))
extern TargetFdTrans target_inotify_trans;
#endif
#endif