HardenedBSD/sys/net/if_clone.h
Zhenlei Huang a2cac544a6 if_clone: Allow maxunit to be zero
Some drivers, e.g. if_enc(4), only allow one instance to be created, but
the KPI ifc_attach_cloner() treat zero value of maxunit as not limited,
aka IF_MAXUNIT.

Introduce a new flag IFC_F_LIMITUNIT to indicate that the requested
maxunit is limited and should be respected.

Consumers should use the new flag if there is an intended limit.

Reviewed by:	glebius
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D45757
2024-07-03 21:14:08 +08:00

163 lines
6.1 KiB
C

/*-
* 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. */
void vnet_if_clone_init(void);
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). */
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_ */