root/sys/net/if_clone.h
/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1982, 1986, 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef _NET_IF_CLONE_H_
#define _NET_IF_CLONE_H_

#ifdef _KERNEL

#include <sys/_eventhandler.h>

#define CLONE_COMPAT_13

struct if_clone;

/* Public KPI */
struct ifc_data {
        uint32_t        flags;
        uint32_t        unit;   /* Selected unit when IFC_C_AUTOUNIT set */
        void            *params;
        struct vnet     *vnet;
};

typedef int ifc_match_f(struct if_clone *ifc, const char *name);
typedef int ifc_create_f(struct if_clone *ifc, char *name, size_t maxlen,
    struct ifc_data *ifd, struct ifnet **ifpp);
typedef int ifc_destroy_f(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags);

struct nl_parsed_link;
struct nlattr_bmask;
struct nl_pstate;
struct nl_writer;
struct ifc_data_nl {
        struct nl_parsed_link           *lattrs;/* (in) Parsed link attributes */
        const struct nlattr_bmask       *bm;    /* (in) Bitmask of set link attributes */
        struct nl_pstate                *npt;   /* (in) Netlink context */
        void                            *params;/* (in) (Compat) data from ioctl */
        uint32_t                        flags;  /* (in) IFC_F flags */
        uint32_t                        unit;   /* (in/out) Selected unit when IFC_C_AUTOUNIT set */
        int                             error;  /* (out) Return error code */
        struct ifnet                    *ifp;   /* (out) Returned ifp */
};

typedef int ifc_create_nl_f(struct if_clone *ifc, char *name, size_t maxlen,
    struct ifc_data_nl *ifd);
typedef int ifc_modify_nl_f(struct ifnet *ifp, struct ifc_data_nl *ifd);
typedef void ifc_dump_nl_f(struct ifnet *ifp, struct nl_writer *nw);

struct if_clone_addreq {
        uint16_t        version; /* Always 0 for now */
        uint16_t        spare;
        uint32_t        flags;
        uint32_t        maxunit; /* Maximum allowed unit number */
        ifc_match_f     *match_f;
        ifc_create_f    *create_f;
        ifc_destroy_f   *destroy_f;
};

struct if_clone_addreq_v2 {
        uint16_t        version; /* 2 */
        uint16_t        spare;
        uint32_t        flags;
        uint32_t        maxunit; /* Maximum allowed unit number */
        ifc_match_f     *match_f;
        ifc_create_f    *create_f;
        ifc_destroy_f   *destroy_f;
        ifc_create_nl_f *create_nl_f;
        ifc_modify_nl_f *modify_nl_f;
        ifc_dump_nl_f   *dump_nl_f;
};

#define IFC_F_SPARE     0x01
#define IFC_F_AUTOUNIT  0x02    /* Creation flag: automatically select unit */
#define IFC_F_SYSSPACE  0x04    /* Cloner callback: params pointer is in kernel memory */
#define IFC_F_FORCE     0x08    /* Deletion flag: force interface deletion */
#define IFC_F_CREATE    0x10    /* Creation flag: indicate creation request */
#define IFC_F_LIMITUNIT 0x20    /* Creation flag: the unit number is limited */

_Static_assert(offsetof(struct if_clone_addreq, destroy_f) ==
    offsetof(struct if_clone_addreq_v2, destroy_f),
    "destroy_f in if_clone_addreq and if_clone_addreq_v2 are at different offset");

struct if_clone *ifc_attach_cloner(const char *name, struct if_clone_addreq *req);
void ifc_detach_cloner(struct if_clone *ifc);
int ifc_create_ifp(const char *name, struct ifc_data *ifd, struct ifnet **ifpp);

bool ifc_create_ifp_nl(const char *name, struct ifc_data_nl *ifd);
bool ifc_modify_ifp_nl(struct ifnet *ifp, struct ifc_data_nl *ifd);
bool ifc_dump_ifp_nl(struct ifnet *ifp, struct nl_writer *nw);

void ifc_link_ifp(struct if_clone *ifc, struct ifnet *ifp);
bool ifc_unlink_ifp(struct if_clone *ifc, struct ifnet *ifp);

int ifc_copyin(const struct ifc_data *ifd, void *target, size_t len);
#ifdef CLONE_COMPAT_13

/* Methods. */
typedef int     ifc_match_t(struct if_clone *, const char *);
typedef int     ifc_create_t(struct if_clone *, char *, size_t, caddr_t);
typedef int     ifc_destroy_t(struct if_clone *, struct ifnet *);

typedef int     ifcs_create_t(struct if_clone *, int, caddr_t);
typedef void    ifcs_destroy_t(struct ifnet *);

/* Interface cloner (de)allocating functions. */
struct if_clone *
        if_clone_advanced(const char *, u_int, ifc_match_t, ifc_create_t,
                      ifc_destroy_t);
struct if_clone *
        if_clone_simple(const char *, ifcs_create_t, ifcs_destroy_t, u_int);
void    if_clone_detach(struct if_clone *);
#endif

/* Unit (de)allocating functions. */
int     ifc_name2unit(const char *name, int *unit);
int     ifc_alloc_unit(struct if_clone *, int *);
void    ifc_free_unit(struct if_clone *, int);

/* Interface clone event. */
typedef void (*if_clone_event_handler_t)(void *, struct if_clone *);
EVENTHANDLER_DECLARE(if_clone_event, if_clone_event_handler_t);

/* The below interfaces used only by net/if.c. */
int     if_clone_create(char *, size_t, caddr_t);
int     if_clone_destroy(const char *);
int     if_clone_list(struct if_clonereq *);
void    if_clone_restoregroup(struct ifnet *);

/* The below interfaces are used only by epair(4) and tun(4)/tap(4). */
void    if_clone_addif(struct if_clone *, struct ifnet *);
int     if_clone_destroyif(struct if_clone *, struct ifnet *);

#endif /* _KERNEL */
#endif /* !_NET_IF_CLONE_H_ */