FreeBSD-5.3/sys/netgraph/ng_device.c
/*
* Copyright (c) 2002 Mark Santcroos <marks@ripe.net>
*
* 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 ``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 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.
*
* Netgraph "device" node
*
* This node presents a /dev/ngd%d device that interfaces to an other
* netgraph node.
*
* $FreeBSD: src/sys/netgraph/ng_device.c,v 1.11 2004/07/20 13:16:17 glebius Exp $
*
*/
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/ioccom.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/poll.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_device.h>
/* turn this on for verbose messages */
#define NGD_DEBUG
#define ERROUT(x) do { error = (x); goto done; } while (0)
/* Netgraph methods */
static ng_constructor_t ng_device_cons;
static ng_rcvmsg_t ng_device_rcvmsg;
static ng_newhook_t ng_device_newhook;
static ng_connect_t ng_device_connect;
static ng_rcvdata_t ng_device_rcvdata;
static ng_disconnect_t ng_device_disconnect;
static int ng_device_mod_event(module_t mod, int event, void *data);
static int ng_device_init(void);
static int get_free_unit(void);
/* Netgraph type */
static struct ng_type typestruct = {
.version = NG_ABI_VERSION,
.name = NG_DEVICE_NODE_TYPE,
.mod_event = ng_device_mod_event,
.constructor = ng_device_cons,
.rcvmsg = ng_device_rcvmsg,
.newhook = ng_device_newhook,
.connect = ng_device_connect,
.rcvdata = ng_device_rcvdata,
.disconnect = ng_device_disconnect,
};
NETGRAPH_INIT(device, &typestruct);
/* per hook data */
struct ngd_connection {
SLIST_ENTRY(ngd_connection) links;
struct cdev *ngddev;
struct ng_hook *active_hook;
char *readq;
int loc;
int unit;
};
/* global data */
struct ngd_softc {
SLIST_HEAD(, ngd_connection) head;
node_p node;
char nodename[NG_NODESIZ];
} ngd_softc;
/* the per connection receiving queue maximum */
#define NGD_QUEUE_SIZE (1024*10)
/* Maximum number of NGD devices */
#define MAX_NGD 25 /* should be more than enough for now */
static d_close_t ngdclose;
static d_open_t ngdopen;
static d_read_t ngdread;
static d_write_t ngdwrite;
static d_ioctl_t ngdioctl;
static d_poll_t ngdpoll;
static struct cdevsw ngd_cdevsw = {
.d_version = D_VERSION,
.d_flags = D_NEEDGIANT,
.d_open = ngdopen,
.d_close = ngdclose,
.d_read = ngdread,
.d_write = ngdwrite,
.d_ioctl = ngdioctl,
.d_poll = ngdpoll,
.d_name = "ngd",
};
/*
* this holds all the stuff that should be done at load time
*/
static int
ng_device_mod_event(module_t mod, int event, void *data)
{
int error = 0;
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif /* NGD_DEBUG */
switch (event) {
case MOD_LOAD:
ng_device_init();
break;
case MOD_UNLOAD:
/* XXX do we need to do something specific ? */
/* ng_device_breakdown */
break;
default:
error = EOPNOTSUPP;
break;
}
return(error);
}
static int
ng_device_init()
{
struct ngd_softc *sc = &ngd_softc;
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif /* NGD_DEBUG */
SLIST_INIT(&sc->head);
if (ng_make_node_common(&typestruct, &sc->node) != 0) {
printf("%s(): ng_make_node_common failed\n",__func__);
return(ENXIO);
}
sprintf(sc->nodename, "%s", NG_DEVICE_NODE_TYPE);
if (ng_name_node(sc->node, sc->nodename)) {
NG_NODE_UNREF(sc->node); /* make it go away again */
printf("%s(): ng_name_node failed\n",__func__);
return(ENXIO);
}
NG_NODE_SET_PRIVATE(sc->node, sc);
return(0);
}
/*
* don't allow to be created, only the device can do that
*/
static int
ng_device_cons(node_p node)
{
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif /* NGD_DEBUG */
return(EINVAL);
}
/*
* Receive control message. We just bounce it back as a reply.
*/
static int
ng_device_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
struct ngd_softc *sc = &ngd_softc;
struct ng_mesg *msg;
int error = 0;
struct ngd_connection * connection = NULL;
struct ngd_connection *tmp = NULL;
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif /* NGD_DEBUG */
NGI_GET_MSG(item, msg);
SLIST_FOREACH(tmp,&sc->head,links) {
if(tmp->active_hook == lasthook) {
connection = tmp;
}
}
if(connection == NULL) {
printf("%s(): connection is still NULL, no hook found\n",__func__);
return(-1);
}
return(error);
}
static int
get_free_unit()
{
struct ngd_connection *tmp = NULL;
struct ngd_softc *sc = &ngd_softc;
int n = 0;
int unit = -1;
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif /* NGD_DEBUG */
/* When there is no list yet, the first device unit is always 0. */
if SLIST_EMPTY(&sc->head) {
unit = 0;
return(unit);
}
/* Just do a brute force loop to find the first free unit that is
* smaller than MAX_NGD.
* Set MAX_NGD to a large value, doesn't impact performance.
*/
for(n = 0;n<MAX_NGD && unit == -1;n++) {
SLIST_FOREACH(tmp,&sc->head,links) {
if(tmp->unit == n) {
unit = -1;
break;
}
unit = n;
}
}
return(unit);
}
/*
* incoming hook
*/
static int
ng_device_newhook(node_p node, hook_p hook, const char *name)
{
struct ngd_softc *sc = &ngd_softc;
struct ngd_connection * new_connection = NULL;
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif
new_connection = malloc(sizeof(struct ngd_connection), M_DEVBUF, M_NOWAIT);
if(new_connection == NULL) {
printf("%s(): ERROR: new_connection == NULL\n",__func__);
return(ENOMEM);
}
new_connection->unit = get_free_unit();
if(new_connection->unit<0) {
printf("%s: No free unit found by get_free_unit(), "
"increase MAX_NGD\n",__func__);
free(new_connection, M_DEVBUF);
return(EINVAL);
}
new_connection->ngddev = make_dev(&ngd_cdevsw, new_connection->unit, 0, 0,0600,"ngd%d",new_connection->unit);
if(new_connection->ngddev == NULL) {
printf("%s(): make_dev failed\n",__func__);
free(new_connection, M_DEVBUF);
return(EINVAL);
}
new_connection->readq = malloc(sizeof(char)*NGD_QUEUE_SIZE, M_DEVBUF, M_NOWAIT | M_ZERO);
if(new_connection->readq == NULL) {
printf("%s(): readq malloc failed\n",__func__);
free(new_connection, M_DEVBUF);
return(ENOMEM);
}
/* point to begin of buffer */
new_connection->loc = 0;
new_connection->active_hook = hook;
SLIST_INSERT_HEAD(&sc->head, new_connection, links);
return(0);
}
/*
* we gave ok to a new hook
* now connect
*/
static int
ng_device_connect(hook_p hook)
{
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif /* NGD_DEBUG */
return(0);
}
/*
* Receive data from hook
*/
static int
ng_device_rcvdata(hook_p hook, item_p item)
{
struct mbuf *m;
struct ngd_softc *sc = &ngd_softc;
struct ngd_connection * connection = NULL;
struct ngd_connection * tmp;
char *buffer;
int error = 0;
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif
NGI_GET_M(item, m);
NG_FREE_ITEM(item);
SLIST_FOREACH(tmp,&sc->head,links)
if(tmp->active_hook == hook)
connection = tmp;
if (connection == NULL) {
printf("%s(): connection is still NULL, no hook found\n",__func__);
ERROUT(ENOTCONN);
}
if ((m = m_pullup(m,m->m_len)) == NULL) {
printf("%s(): ERROR: m_pullup failed\n",__func__);
ERROUT(ENOMEM);
}
buffer = mtod(m,char *);
if ((connection->loc + m->m_len) < NGD_QUEUE_SIZE) {
memcpy(connection->readq + connection->loc, buffer, m->m_len);
connection->loc += m->m_len;
} else {
printf("%s(): queue full, first read out a bit\n",__func__);
ERROUT(ENOSPC);
}
done:
NG_FREE_M(m);
return(error);
}
/*
* Removal of the last link destroys the node
*/
static int
ng_device_disconnect(hook_p hook)
{
struct ngd_softc *sc = &ngd_softc;
struct ngd_connection * connection = NULL;
struct ngd_connection * tmp;
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif
SLIST_FOREACH(tmp,&sc->head,links)
if(tmp->active_hook == hook)
connection = tmp;
if(connection == NULL) {
printf("%s(): connection is still NULL, no hook found\n",__func__);
return(ENOTCONN);
}
free(connection->readq, M_DEVBUF);
destroy_dev(connection->ngddev);
SLIST_REMOVE(&sc->head,connection,ngd_connection,links);
free(connection, M_DEVBUF);
return(0);
}
/*
* the device is opened
*/
static int
ngdopen(struct cdev *dev, int flag, int mode, struct thread *td)
{
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif /* NGD_DEBUG */
return(0);
}
/*
* the device is closed
*/
static int
ngdclose(struct cdev *dev, int flag, int mode, struct thread *td)
{
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif
return(0);
}
/*
* process ioctl
*
* they are translated into netgraph messages and passed on
*
*/
static int
ngdioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
{
struct ngd_softc *sc = &ngd_softc;
struct ngd_connection * connection = NULL;
struct ngd_connection * tmp;
int error = 0;
struct ng_mesg *msg;
struct ngd_param_s * datap;
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif /* NGD_DEBUG */
SLIST_FOREACH(tmp,&sc->head,links) {
if(tmp->ngddev == dev) {
connection = tmp;
}
}
if(connection == NULL) {
printf("%s(): connection is still NULL, no dev found\n",__func__);
return(-1);
}
/* NG_MKMESSAGE(msg, cookie, cmdid, len, how) */
NG_MKMESSAGE(msg, NGM_DEVICE_COOKIE, cmd, sizeof(struct ngd_param_s),
M_NOWAIT);
if (msg == NULL) {
printf("%s(): msg == NULL\n",__func__);
goto nomsg;
}
/* pass the ioctl data into the ->data area */
datap = (struct ngd_param_s *)msg->data;
datap->p = addr;
NG_SEND_MSG_HOOK(error, sc->node, msg, connection->active_hook, 0);
if(error)
printf("%s(): NG_SEND_MSG_HOOK error: %d\n",__func__,error);
nomsg:
return(0);
}
/*
* This function is called when a read(2) is done to our device.
* We pass the data available in kernelspace on into userland using
* uiomove.
*/
static int
ngdread(struct cdev *dev, struct uio *uio, int flag)
{
int ret = 0, amnt;
char buffer[uio->uio_resid+1];
struct ngd_softc *sc = &ngd_softc;
struct ngd_connection * connection = NULL;
struct ngd_connection * tmp;
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif /* NGD_DEBUG */
SLIST_FOREACH(tmp,&sc->head,links) {
if(tmp->ngddev == dev) {
connection = tmp;
}
}
if(connection == NULL) {
printf("%s(): connection is still NULL, no dev found\n",__func__);
return(-1);
}
while ( ( uio->uio_resid > 0 ) && ( connection->loc > 0 ) ) {
amnt = MIN(uio->uio_resid,connection->loc);
memcpy(buffer,connection->readq, amnt);
memcpy(connection->readq, connection->readq+amnt,
connection->loc-amnt);
connection->loc -= amnt;
ret = uiomove((caddr_t)buffer, amnt, uio);
if(ret != 0)
goto error;
}
return(0);
error:
printf("%s(): uiomove returns error %d\n",__func__,ret);
/* do error cleanup here */
return(ret);
}
/*
* This function is called when our device is written to.
* We read the data from userland into our local buffer and pass it on
* into the remote hook.
*
*/
static int
ngdwrite(struct cdev *dev, struct uio *uio, int flag)
{
int ret;
int error = 0;
struct mbuf *m;
char buffer[uio->uio_resid];
int len = uio->uio_resid;
struct ngd_softc *sc =& ngd_softc;
struct ngd_connection * connection = NULL;
struct ngd_connection * tmp;
#ifdef NGD_DEBUG
printf("%s()\n",__func__);
#endif /* NGD_DEBUG */
SLIST_FOREACH(tmp,&sc->head,links) {
if(tmp->ngddev == dev) {
connection = tmp;
}
}
if(connection == NULL) {
printf("%s(): connection is still NULL, no dev found\n",__func__);
return(-1);
}
if (len > 0) {
if ((ret = uiomove((caddr_t)buffer, len, uio)) != 0)
goto error;
} else
printf("%s(): len <= 0 : is this supposed to happen?!\n",__func__);
m = m_devget(buffer,len,0,NULL,NULL);
NG_SEND_DATA_ONLY(error,connection->active_hook,m);
return(0);
error:
/* do error cleanup here */
printf("%s(): uiomove returned err: %d\n",__func__,ret);
return(ret);
}
/*
* we are being polled/selected
* check if there is data available for read
*/
static int
ngdpoll(struct cdev *dev, int events, struct thread *td)
{
int revents = 0;
struct ngd_softc *sc = &ngd_softc;
struct ngd_connection * connection = NULL;
struct ngd_connection * tmp;
if (events & (POLLIN | POLLRDNORM)) {
/* get the connection we have to know the loc from */
SLIST_FOREACH(tmp,&sc->head,links) {
if(tmp->ngddev == dev) {
connection = tmp;
}
}
if(connection == NULL) {
printf("%s(): ERROR: connection is still NULL,"
"no dev found\n",__func__);
return(-1);
}
if (connection->loc > 0)
revents |= events & (POLLIN | POLLRDNORM);
}
return(revents);
}