freebsd-dev/sys/net/vnet.h
Mike Karels efe58855f3 IPv4: experimental changes to allow net 0/8, 240/4, part of 127/8
Combined changes to allow experimentation with net 0/8 (network 0),
240/4 (Experimental/"Class E"), and part of the loopback net 127/8
(all but 127.0/16).  All changes are disabled by default, and can be
enabled by the following sysctls:

    net.inet.ip.allow_net0=1
    net.inet.ip.allow_net240=1
    net.inet.ip.loopback_prefixlen=16

When enabled, the corresponding addresses can be used as normal
unicast IP addresses, both as endpoints and when forwarding.

Add descriptions of the new sysctls to inet.4.

Add <machine/param.h> to vnet.h, as CACHE_LINE_SIZE is undefined in
various C files when in.h includes vnet.h.

The proposals motivating this experimentation can be found in

    https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-0
    https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-240
    https://datatracker.ietf.org/doc/draft-schoen-intarea-unicast-127

Reviewed by:	rgrimes, pauamma_gundo.com; previous versions melifaro, glebius
Differential Revision: https://reviews.freebsd.org/D35741
2022-07-13 09:46:05 -05:00

464 lines
15 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2006-2009 University of Zagreb
* Copyright (c) 2006-2009 FreeBSD Foundation
* All rights reserved.
*
* This software was developed by the University of Zagreb and the
* FreeBSD Foundation under sponsorship by the Stichting NLnet and the
* FreeBSD Foundation.
*
* Copyright (c) 2009 Jeffrey Roberson <jeff@freebsd.org>
* Copyright (c) 2009 Robert N. M. Watson
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
/*-
* This header file defines several sets of interfaces supporting virtualized
* network stacks:
*
* - Definition of 'struct vnet' and functions and macros to allocate/free/
* manipulate it.
*
* - A virtual network stack memory allocator, which provides support for
* virtualized global variables via a special linker set, set_vnet.
*
* - Virtualized sysinits/sysuninits, which allow constructors and
* destructors to be run for each network stack subsystem as virtual
* instances are created and destroyed.
*
* If VIMAGE isn't compiled into the kernel, virtualized global variables
* compile to normal global variables, and virtualized sysinits to regular
* sysinits.
*/
#ifndef _NET_VNET_H_
#define _NET_VNET_H_
/*
* struct vnet describes a virtualized network stack, and is primarily a
* pointer to storage for virtualized global variables. Expose to userspace
* as required for libkvm.
*/
#if defined(_KERNEL) || defined(_WANT_VNET)
#include <machine/param.h> /* for CACHE_LINE_SIZE */
#include <sys/queue.h>
struct vnet {
LIST_ENTRY(vnet) vnet_le; /* all vnets list */
u_int vnet_magic_n;
u_int vnet_ifcnt;
u_int vnet_sockcnt;
u_int vnet_state; /* SI_SUB_* */
void *vnet_data_mem;
uintptr_t vnet_data_base;
bool vnet_shutdown; /* Shutdown in progress. */
} __aligned(CACHE_LINE_SIZE);
#define VNET_MAGIC_N 0x5e4a6f28
/*
* These two virtual network stack allocator definitions are also required
* for libkvm so that it can evaluate virtualized global variables.
*/
#define VNET_SETNAME "set_vnet"
#define VNET_SYMPREFIX "vnet_entry_"
#endif
#ifdef _KERNEL
#define VNET_PCPUSTAT_DECLARE(type, name) \
VNET_DECLARE(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
#define VNET_PCPUSTAT_DEFINE(type, name) \
VNET_DEFINE(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
#define VNET_PCPUSTAT_DEFINE_STATIC(type, name) \
VNET_DEFINE_STATIC(counter_u64_t, name[sizeof(type) / sizeof(uint64_t)])
#define VNET_PCPUSTAT_ALLOC(name, wait) \
COUNTER_ARRAY_ALLOC(VNET(name), \
sizeof(VNET(name)) / sizeof(counter_u64_t), (wait))
#define VNET_PCPUSTAT_FREE(name) \
COUNTER_ARRAY_FREE(VNET(name), sizeof(VNET(name)) / sizeof(counter_u64_t))
#define VNET_PCPUSTAT_ADD(type, name, f, v) \
counter_u64_add(VNET(name)[offsetof(type, f) / sizeof(uint64_t)], (v))
#define VNET_PCPUSTAT_FETCH(type, name, f) \
counter_u64_fetch(VNET(name)[offsetof(type, f) / sizeof(uint64_t)])
#define VNET_PCPUSTAT_SYSINIT(name) \
static void \
vnet_##name##_init(const void *unused) \
{ \
VNET_PCPUSTAT_ALLOC(name, M_WAITOK); \
} \
VNET_SYSINIT(vnet_ ## name ## _init, SI_SUB_INIT_IF, \
SI_ORDER_FIRST, vnet_ ## name ## _init, NULL)
#define VNET_PCPUSTAT_SYSUNINIT(name) \
static void \
vnet_##name##_uninit(const void *unused) \
{ \
VNET_PCPUSTAT_FREE(name); \
} \
VNET_SYSUNINIT(vnet_ ## name ## _uninit, SI_SUB_INIT_IF, \
SI_ORDER_FIRST, vnet_ ## name ## _uninit, NULL)
#ifdef SYSCTL_OID
#define SYSCTL_VNET_PCPUSTAT(parent, nbr, name, type, array, desc) \
static int \
array##_sysctl(SYSCTL_HANDLER_ARGS) \
{ \
type s; \
CTASSERT((sizeof(type) / sizeof(uint64_t)) == \
(sizeof(VNET(array)) / sizeof(counter_u64_t))); \
COUNTER_ARRAY_COPY(VNET(array), &s, sizeof(type) / sizeof(uint64_t));\
if (req->newptr) \
COUNTER_ARRAY_ZERO(VNET(array), \
sizeof(type) / sizeof(uint64_t)); \
return (SYSCTL_OUT(req, &s, sizeof(type))); \
} \
SYSCTL_PROC(parent, nbr, name, \
CTLFLAG_VNET | CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_NEEDGIANT, \
NULL, 0, array ## _sysctl, "I", desc)
#endif /* SYSCTL_OID */
#ifdef VIMAGE
#include <sys/lock.h>
#include <sys/proc.h> /* for struct thread */
#include <sys/rwlock.h>
#include <sys/sx.h>
/*
* Location of the kernel's 'set_vnet' linker set.
*/
extern uintptr_t *__start_set_vnet;
__GLOBL(__start_set_vnet);
extern uintptr_t *__stop_set_vnet;
__GLOBL(__stop_set_vnet);
#define VNET_START (uintptr_t)&__start_set_vnet
#define VNET_STOP (uintptr_t)&__stop_set_vnet
/*
* Functions to allocate and destroy virtual network stacks.
*/
struct vnet *vnet_alloc(void);
void vnet_destroy(struct vnet *vnet);
/*
* The current virtual network stack -- we may wish to move this to struct
* pcpu in the future.
*/
#define curvnet curthread->td_vnet
/*
* Various macros -- get and set the current network stack, but also
* assertions.
*/
#if defined(INVARIANTS) || defined(VNET_DEBUG)
#define VNET_ASSERT(exp, msg) do { \
if (!(exp)) \
panic msg; \
} while (0)
#else
#define VNET_ASSERT(exp, msg) do { \
} while (0)
#endif
#ifdef VNET_DEBUG
void vnet_log_recursion(struct vnet *, const char *, int);
#define CURVNET_SET_QUIET(arg) \
VNET_ASSERT((arg) != NULL && (arg)->vnet_magic_n == VNET_MAGIC_N, \
("CURVNET_SET at %s:%d %s() curvnet=%p vnet=%p", \
__FILE__, __LINE__, __func__, curvnet, (arg))); \
struct vnet *saved_vnet = curvnet; \
const char *saved_vnet_lpush = curthread->td_vnet_lpush; \
curvnet = arg; \
curthread->td_vnet_lpush = __func__;
#define CURVNET_SET_VERBOSE(arg) \
CURVNET_SET_QUIET(arg) \
if (saved_vnet) \
vnet_log_recursion(saved_vnet, saved_vnet_lpush, __LINE__);
#define CURVNET_SET(arg) CURVNET_SET_VERBOSE(arg)
#define CURVNET_RESTORE() \
VNET_ASSERT(curvnet != NULL && (saved_vnet == NULL || \
saved_vnet->vnet_magic_n == VNET_MAGIC_N), \
("CURVNET_RESTORE at %s:%d %s() curvnet=%p saved_vnet=%p", \
__FILE__, __LINE__, __func__, curvnet, saved_vnet)); \
curvnet = saved_vnet; \
curthread->td_vnet_lpush = saved_vnet_lpush;
#else /* !VNET_DEBUG */
#define CURVNET_SET_QUIET(arg) \
VNET_ASSERT((arg) != NULL && (arg)->vnet_magic_n == VNET_MAGIC_N, \
("CURVNET_SET at %s:%d %s() curvnet=%p vnet=%p", \
__FILE__, __LINE__, __func__, curvnet, (arg))); \
struct vnet *saved_vnet = curvnet; \
curvnet = arg;
#define CURVNET_SET_VERBOSE(arg) \
CURVNET_SET_QUIET(arg)
#define CURVNET_SET(arg) CURVNET_SET_VERBOSE(arg)
#define CURVNET_RESTORE() \
VNET_ASSERT(curvnet != NULL && (saved_vnet == NULL || \
saved_vnet->vnet_magic_n == VNET_MAGIC_N), \
("CURVNET_RESTORE at %s:%d %s() curvnet=%p saved_vnet=%p", \
__FILE__, __LINE__, __func__, curvnet, saved_vnet)); \
curvnet = saved_vnet;
#endif /* VNET_DEBUG */
#define CURVNET_ASSERT_SET() \
VNET_ASSERT(curvnet != NULL, ("vnet is not set at %s:%d %s()", \
__FILE__, __LINE__, __func__))
extern struct vnet *vnet0;
#define IS_DEFAULT_VNET(arg) ((arg) == vnet0)
#define CRED_TO_VNET(cr) (cr)->cr_prison->pr_vnet
#define TD_TO_VNET(td) CRED_TO_VNET((td)->td_ucred)
#define P_TO_VNET(p) CRED_TO_VNET((p)->p_ucred)
/*
* Global linked list of all virtual network stacks, along with read locks to
* access it. If a caller may sleep while accessing the list, it must use
* the sleepable lock macros.
*/
LIST_HEAD(vnet_list_head, vnet);
extern struct vnet_list_head vnet_head;
extern struct rwlock vnet_rwlock;
extern struct sx vnet_sxlock;
#define VNET_LIST_RLOCK() sx_slock(&vnet_sxlock)
#define VNET_LIST_RLOCK_NOSLEEP() rw_rlock(&vnet_rwlock)
#define VNET_LIST_RUNLOCK() sx_sunlock(&vnet_sxlock)
#define VNET_LIST_RUNLOCK_NOSLEEP() rw_runlock(&vnet_rwlock)
/*
* Iteration macros to walk the global list of virtual network stacks.
*/
#define VNET_ITERATOR_DECL(arg) struct vnet *arg
#define VNET_FOREACH(arg) LIST_FOREACH((arg), &vnet_head, vnet_le)
/*
* Virtual network stack memory allocator, which allows global variables to
* be automatically instantiated for each network stack instance.
*/
#define VNET_NAME(n) vnet_entry_##n
#define VNET_DECLARE(t, n) extern t VNET_NAME(n)
/* struct _hack is to stop this from being used with static data */
#define VNET_DEFINE(t, n) \
struct _hack; t VNET_NAME(n) __section(VNET_SETNAME) __used
#if defined(KLD_MODULE) && (defined(__aarch64__) || defined(__riscv) \
|| defined(__powerpc64__))
/*
* As with DPCPU_DEFINE_STATIC we are unable to mark this data as static
* in modules on some architectures.
*/
#define VNET_DEFINE_STATIC(t, n) \
t VNET_NAME(n) __section(VNET_SETNAME) __used
#else
#define VNET_DEFINE_STATIC(t, n) \
static t VNET_NAME(n) __section(VNET_SETNAME) __used
#endif
#define _VNET_PTR(b, n) (__typeof(VNET_NAME(n))*) \
((b) + (uintptr_t)&VNET_NAME(n))
#define _VNET(b, n) (*_VNET_PTR(b, n))
/*
* Virtualized global variable accessor macros.
*/
#define VNET_VNET_PTR(vnet, n) _VNET_PTR((vnet)->vnet_data_base, n)
#define VNET_VNET(vnet, n) (*VNET_VNET_PTR((vnet), n))
#define VNET_PTR(n) VNET_VNET_PTR(curvnet, n)
#define VNET(n) VNET_VNET(curvnet, n)
/*
* Virtual network stack allocator interfaces from the kernel linker.
*/
void *vnet_data_alloc(int size);
void vnet_data_copy(void *start, int size);
void vnet_data_free(void *start_arg, int size);
/*
* Virtual sysinit mechanism, allowing network stack components to declare
* startup and shutdown methods to be run when virtual network stack
* instances are created and destroyed.
*/
#include <sys/kernel.h>
/*
* SYSINIT/SYSUNINIT variants that provide per-vnet constructors and
* destructors.
*/
struct vnet_sysinit {
enum sysinit_sub_id subsystem;
enum sysinit_elem_order order;
sysinit_cfunc_t func;
const void *arg;
TAILQ_ENTRY(vnet_sysinit) link;
};
#define VNET_SYSINIT(ident, subsystem, order, func, arg) \
CTASSERT((subsystem) > SI_SUB_VNET && \
(subsystem) <= SI_SUB_VNET_DONE); \
static struct vnet_sysinit ident ## _vnet_init = { \
subsystem, \
order, \
(sysinit_cfunc_t)(sysinit_nfunc_t)func, \
(arg) \
}; \
SYSINIT(vnet_init_ ## ident, subsystem, order, \
vnet_register_sysinit, &ident ## _vnet_init); \
SYSUNINIT(vnet_init_ ## ident, subsystem, order, \
vnet_deregister_sysinit, &ident ## _vnet_init)
#define VNET_SYSUNINIT(ident, subsystem, order, func, arg) \
CTASSERT((subsystem) > SI_SUB_VNET && \
(subsystem) <= SI_SUB_VNET_DONE); \
static struct vnet_sysinit ident ## _vnet_uninit = { \
subsystem, \
order, \
(sysinit_cfunc_t)(sysinit_nfunc_t)func, \
(arg) \
}; \
SYSINIT(vnet_uninit_ ## ident, subsystem, order, \
vnet_register_sysuninit, &ident ## _vnet_uninit); \
SYSUNINIT(vnet_uninit_ ## ident, subsystem, order, \
vnet_deregister_sysuninit, &ident ## _vnet_uninit)
/*
* Run per-vnet sysinits or sysuninits during vnet creation/destruction.
*/
void vnet_sysinit(void);
void vnet_sysuninit(void);
/*
* Interfaces for managing per-vnet constructors and destructors.
*/
void vnet_register_sysinit(void *arg);
void vnet_register_sysuninit(void *arg);
void vnet_deregister_sysinit(void *arg);
void vnet_deregister_sysuninit(void *arg);
/*
* EVENTHANDLER(9) extensions.
*/
#include <sys/eventhandler.h>
void vnet_global_eventhandler_iterator_func(void *, ...);
#define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
do { \
if (IS_DEFAULT_VNET(curvnet)) { \
(tag) = vimage_eventhandler_register(NULL, #name, func, \
arg, priority, \
vnet_global_eventhandler_iterator_func); \
} \
} while(0)
#define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority) \
do { \
if (IS_DEFAULT_VNET(curvnet)) { \
vimage_eventhandler_register(NULL, #name, func, \
arg, priority, \
vnet_global_eventhandler_iterator_func); \
} \
} while(0)
#else /* !VIMAGE */
/*
* Various virtual network stack macros compile to no-ops without VIMAGE.
*/
#define curvnet NULL
#define VNET_ASSERT(exp, msg)
#define CURVNET_SET(arg)
#define CURVNET_SET_QUIET(arg)
#define CURVNET_RESTORE()
#define CURVNET_ASSERT_SET() \
#define VNET_LIST_RLOCK()
#define VNET_LIST_RLOCK_NOSLEEP()
#define VNET_LIST_RUNLOCK()
#define VNET_LIST_RUNLOCK_NOSLEEP()
#define VNET_ITERATOR_DECL(arg)
#define VNET_FOREACH(arg) for (int _vn = 0; _vn == 0; _vn++)
#define IS_DEFAULT_VNET(arg) 1
#define CRED_TO_VNET(cr) NULL
#define TD_TO_VNET(td) NULL
#define P_TO_VNET(p) NULL
/*
* Versions of the VNET macros that compile to normal global variables and
* standard sysctl definitions.
*/
#define VNET_NAME(n) n
#define VNET_DECLARE(t, n) extern t n
#define VNET_DEFINE(t, n) struct _hack; t n
#define VNET_DEFINE_STATIC(t, n) static t n
#define _VNET_PTR(b, n) &VNET_NAME(n)
/*
* Virtualized global variable accessor macros.
*/
#define VNET_VNET_PTR(vnet, n) (&(n))
#define VNET_VNET(vnet, n) (n)
#define VNET_PTR(n) (&(n))
#define VNET(n) (n)
/*
* When VIMAGE isn't compiled into the kernel, VNET_SYSINIT/VNET_SYSUNINIT
* map into normal sysinits, which have the same ordering properties.
*/
#define VNET_SYSINIT(ident, subsystem, order, func, arg) \
SYSINIT(ident, subsystem, order, func, arg)
#define VNET_SYSUNINIT(ident, subsystem, order, func, arg) \
SYSUNINIT(ident, subsystem, order, func, arg)
/*
* Without VIMAGE revert to the default implementation.
*/
#define VNET_GLOBAL_EVENTHANDLER_REGISTER_TAG(tag, name, func, arg, priority) \
(tag) = eventhandler_register(NULL, #name, func, arg, priority)
#define VNET_GLOBAL_EVENTHANDLER_REGISTER(name, func, arg, priority) \
eventhandler_register(NULL, #name, func, arg, priority)
#endif /* VIMAGE */
#endif /* _KERNEL */
#endif /* !_NET_VNET_H_ */