freebsd-dev/sys/net/raw_cb.c
Robert Watson eddfbb763d Build on Jeff Roberson's linker-set based dynamic per-CPU allocator
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator.  Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...).  This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack.  Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory.  Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy.  Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address.  When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by:  bz
Reviewed by:            bz, zec
Discussed with:         gnn, jamie, jeff, jhb, julian, sam
Suggested by:           peter
Approved by:            re (kensmith)
2009-07-14 22:48:30 +00:00

119 lines
3.7 KiB
C

/*-
* Copyright (c) 1980, 1986, 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.
* 4. 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.
*
* @(#)raw_cb.c 8.1 (Berkeley) 6/10/93
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/domain.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/vimage.h>
#include <net/if.h>
#include <net/raw_cb.h>
#include <net/vnet.h>
/*
* Routines to manage the raw protocol control blocks.
*
* TODO:
* hash lookups by protocol family/protocol + address family
* take care of unique address problems per AF?
* redo address binding to allow wildcards
*/
struct mtx rawcb_mtx;
VNET_DEFINE(struct rawcb_list_head, rawcb_list);
SYSCTL_NODE(_net, OID_AUTO, raw, CTLFLAG_RW, 0, "Raw socket infrastructure");
static u_long raw_sendspace = RAWSNDQ;
SYSCTL_ULONG(_net_raw, OID_AUTO, sendspace, CTLFLAG_RW, &raw_sendspace, 0,
"Default raw socket send space");
static u_long raw_recvspace = RAWRCVQ;
SYSCTL_ULONG(_net_raw, OID_AUTO, recvspace, CTLFLAG_RW, &raw_recvspace, 0,
"Default raw socket receive space");
/*
* Allocate a control block and a nominal amount of buffer space for the
* socket.
*/
int
raw_attach(struct socket *so, int proto)
{
struct rawcb *rp = sotorawcb(so);
int error;
/*
* It is assumed that raw_attach is called after space has been
* allocated for the rawcb; consumer protocols may simply allocate
* type struct rawcb, or a wrapper data structure that begins with a
* struct rawcb.
*/
KASSERT(rp != NULL, ("raw_attach: rp == NULL"));
error = soreserve(so, raw_sendspace, raw_recvspace);
if (error)
return (error);
rp->rcb_socket = so;
rp->rcb_proto.sp_family = so->so_proto->pr_domain->dom_family;
rp->rcb_proto.sp_protocol = proto;
mtx_lock(&rawcb_mtx);
LIST_INSERT_HEAD(&V_rawcb_list, rp, list);
mtx_unlock(&rawcb_mtx);
return (0);
}
/*
* Detach the raw connection block and discard socket resources.
*/
void
raw_detach(struct rawcb *rp)
{
struct socket *so = rp->rcb_socket;
KASSERT(so->so_pcb == rp, ("raw_detach: so_pcb != rp"));
so->so_pcb = NULL;
mtx_lock(&rawcb_mtx);
LIST_REMOVE(rp, list);
mtx_unlock(&rawcb_mtx);
free((caddr_t)(rp), M_PCB);
}