freebsd-skq/sys/netinet/tcp_offload.c
rwatson 57ca4583e7 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

146 lines
3.4 KiB
C

/*-
* Copyright (c) 2007, Chelsio Inc.
* 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. Neither the name of the Chelsio Corporation 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/vimage.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_var.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_pcb.h>
#include <netinet/tcp.h>
#include <netinet/tcp_var.h>
#include <netinet/tcp_offload.h>
#include <netinet/toedev.h>
uint32_t toedev_registration_count;
int
tcp_offload_connect(struct socket *so, struct sockaddr *nam)
{
struct ifnet *ifp;
struct toedev *tdev;
struct rtentry *rt;
int error;
if (toedev_registration_count == 0)
return (EINVAL);
/*
* Look up the route used for the connection to
* determine if it uses an interface capable of
* offloading the connection.
*/
rt = rtalloc1(nam, 0 /*report*/, 0 /*ignflags*/);
if (rt)
RT_UNLOCK(rt);
else
return (EHOSTUNREACH);
ifp = rt->rt_ifp;
if ((ifp->if_capenable & IFCAP_TOE) == 0) {
error = EINVAL;
goto fail;
}
tdev = TOEDEV(ifp);
if (tdev == NULL) {
error = EPERM;
goto fail;
}
if (tdev->tod_can_offload(tdev, so) == 0) {
error = EPERM;
goto fail;
}
return (tdev->tod_connect(tdev, so, rt, nam));
fail:
RTFREE(rt);
return (error);
}
/*
* This file contains code as a short-term staging area before it is moved in
* to sys/netinet/tcp_offload.c
*/
void
tcp_offload_twstart(struct tcpcb *tp)
{
INP_INFO_WLOCK(&V_tcbinfo);
INP_WLOCK(tp->t_inpcb);
tcp_twstart(tp);
INP_INFO_WUNLOCK(&V_tcbinfo);
}
struct tcpcb *
tcp_offload_close(struct tcpcb *tp)
{
INP_INFO_WLOCK(&V_tcbinfo);
INP_WLOCK(tp->t_inpcb);
tp = tcp_close(tp);
INP_INFO_WUNLOCK(&V_tcbinfo);
if (tp)
INP_WUNLOCK(tp->t_inpcb);
return (tp);
}
struct tcpcb *
tcp_offload_drop(struct tcpcb *tp, int error)
{
INP_INFO_WLOCK(&V_tcbinfo);
INP_WLOCK(tp->t_inpcb);
tp = tcp_drop(tp, error);
INP_INFO_WUNLOCK(&V_tcbinfo);
if (tp)
INP_WUNLOCK(tp->t_inpcb);
return (tp);
}