/*
* ng_ether.c
*
* Copyright (c) 1996-2000 Whistle Communications, Inc.
* All rights reserved.
*
* Subject to the following obligations and disclaimer of warranty, use and
* redistribution of this software, in source or object code forms, with or
* without modifications are expressly permitted by Whistle Communications;
* provided, however, that:
* 1. Any and all reproductions of the source or object code must include the
* copyright notice above and the following disclaimer of warranties; and
* 2. No rights are granted, in any manner or form, to use Whistle
* Communications, Inc. trademarks, including the mark "WHISTLE
* COMMUNICATIONS" on advertising, endorsements, or otherwise except as
* such appears in the above copyright notice or in the software.
*
* THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
* TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
* REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
* INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
* WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
* REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
* SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
* IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
* RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
* WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
* PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER 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 WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* Authors: Archie Cobbs <archie@freebsd.org>
* Julian Elischer <julian@freebsd.org>
*
* $FreeBSD$
*/
/*
* ng_ether(4) netgraph node type
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/syslog.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_arp.h>
#include <net/if_var.h>
#include <net/ethernet.h>
#include <netgraph/ng_message.h>
#include <netgraph/netgraph.h>
#include <netgraph/ng_parse.h>
#include <netgraph/ng_ether.h>
#define IFP2AC(IFP) ((struct arpcom *)IFP)
#define IFP2NG(ifp) ((struct ng_node *)((struct arpcom *)(ifp))->ac_netgraph)
/* Per-node private data */
struct private {
struct ifnet *ifp; /* associated interface */
hook_p upper; /* upper hook connection */
hook_p lower; /* lower OR orphan hook connection */
u_char lowerOrphan; /* whether lower is lower or orphan */
u_char autoSrcAddr; /* always overwrite source address */
u_char promisc; /* promiscuous mode enabled */
u_long hwassist; /* hardware checksum capabilities */
};
typedef struct private *priv_p;
/* Functional hooks called from if_ethersubr.c */
static void ng_ether_input(struct ifnet *ifp,
struct mbuf **mp, struct ether_header *eh);
static void ng_ether_input_orphan(struct ifnet *ifp,
struct mbuf *m, struct ether_header *eh);
static int ng_ether_output(struct ifnet *ifp, struct mbuf **mp);
static void ng_ether_attach(struct ifnet *ifp);
static void ng_ether_detach(struct ifnet *ifp);
/* Other functions */
static void ng_ether_input2(node_p node,
struct mbuf **mp, struct ether_header *eh);
static int ng_ether_glueback_header(struct mbuf **mp,
struct ether_header *eh);
static int ng_ether_rcv_lower(node_p node, struct mbuf *m, meta_p meta);
static int ng_ether_rcv_upper(node_p node, struct mbuf *m, meta_p meta);
/* Netgraph node methods */
static ng_constructor_t ng_ether_constructor;
static ng_rcvmsg_t ng_ether_rcvmsg;
static ng_shutdown_t ng_ether_rmnode;
static ng_newhook_t ng_ether_newhook;
static ng_rcvdata_t ng_ether_rcvdata;
static ng_disconnect_t ng_ether_disconnect;
static int ng_ether_mod_event(module_t mod, int event, void *data);
/* List of commands and how to convert arguments to/from ASCII */
static const struct ng_cmdlist ng_ether_cmdlist[] = {
{
NGM_ETHER_COOKIE,
NGM_ETHER_GET_IFNAME,
"getifname",
NULL,
&ng_parse_string_type
},
{
NGM_ETHER_COOKIE,
NGM_ETHER_GET_IFINDEX,
"getifindex",
NULL,
&ng_parse_int32_type
},
{
NGM_ETHER_COOKIE,
NGM_ETHER_GET_ENADDR,
"getenaddr",
NULL,
&ng_parse_enaddr_type
},
{
NGM_ETHER_COOKIE,
NGM_ETHER_SET_ENADDR,
"setenaddr",
&ng_parse_enaddr_type,
NULL
},
{
NGM_ETHER_COOKIE,
NGM_ETHER_GET_PROMISC,
"getpromisc",
NULL,
&ng_parse_int32_type
},
{
NGM_ETHER_COOKIE,
NGM_ETHER_SET_PROMISC,
"setpromisc",
&ng_parse_int32_type,
NULL
},
{
NGM_ETHER_COOKIE,
NGM_ETHER_GET_AUTOSRC,
"getautosrc",
NULL,
&ng_parse_int32_type
},
{
NGM_ETHER_COOKIE,
NGM_ETHER_SET_AUTOSRC,
"setautosrc",
&ng_parse_int32_type,
NULL
},
{ 0 }
};
static struct ng_type ng_ether_typestruct = {
NG_VERSION,
NG_ETHER_NODE_TYPE,
ng_ether_mod_event,
ng_ether_constructor,
ng_ether_rcvmsg,
ng_ether_rmnode,
ng_ether_newhook,
NULL,
NULL,
ng_ether_rcvdata,
ng_ether_rcvdata,
ng_ether_disconnect,
ng_ether_cmdlist,
};
NETGRAPH_INIT(ether, &ng_ether_typestruct);
/******************************************************************
ETHERNET FUNCTION HOOKS
******************************************************************/
/*
* Handle a packet that has come in on an interface. We get to
* look at it here before any upper layer protocols do.
*
* NOTE: this function will get called at splimp()
*/
static void
ng_ether_input(struct ifnet *ifp,
struct mbuf **mp, struct ether_header *eh)
{
const node_p node = IFP2NG(ifp);
const priv_p priv = node->private;
/* If "lower" hook not connected, let packet continue */
if (priv->lower == NULL || priv->lowerOrphan)
return;
ng_ether_input2(node, mp, eh);
}
/*
* Handle a packet that has come in on an interface, and which
* does not match any of our known protocols (an ``orphan'').
*
* NOTE: this function will get called at splimp()
*/
static void
ng_ether_input_orphan(struct ifnet *ifp,
struct mbuf *m, struct ether_header *eh)
{
const node_p node = IFP2NG(ifp);
const priv_p priv = node->private;
/* If "orphan" hook not connected, let packet continue */
if (priv->lower == NULL || !priv->lowerOrphan) {
m_freem(m);
return;
}
ng_ether_input2(node, &m, eh);
if (m != NULL)
m_freem(m);
}
/*
* Handle a packet that has come in on an interface.
* The Ethernet header has already been detached from the mbuf,
* so we have to put it back.
*
* NOTE: this function will get called at splimp()
*/
static void
ng_ether_input2(node_p node, struct mbuf **mp, struct ether_header *eh)
{
const priv_p priv = node->private;
meta_p meta = NULL;
int error;
/* Glue Ethernet header back on */
if ((error = ng_ether_glueback_header(mp, eh)) != 0)
return;
/* Send out lower/orphan hook */
(void)ng_queue_data(priv->lower, *mp, meta);
*mp = NULL;
}
/*
* Handle a packet that is going out on an interface.
* The Ethernet header is already attached to the mbuf.
*/
static int
ng_ether_output(struct ifnet *ifp, struct mbuf **mp)
{
const node_p node = IFP2NG(ifp);
const priv_p priv = node->private;
meta_p meta = NULL;
int error = 0;
/* If "upper" hook not connected, let packet continue */
if (priv->upper == NULL)
return (0);
/* Send it out "upper" hook */
NG_SEND_DATA(error, priv->upper, *mp, meta);
*mp = NULL;
return (error);
}
/*
* A new Ethernet interface has been attached.
* Create a new node for it, etc.
*/
static void
ng_ether_attach(struct ifnet *ifp)
{
char name[IFNAMSIZ + 1];
priv_p priv;
node_p node;
/* Create node */
KASSERT(!IFP2NG(ifp), ("%s: node already exists?", __FUNCTION__));
snprintf(name, sizeof(name), "%s%d", ifp->if_name, ifp->if_unit);
if (ng_make_node_common(&ng_ether_typestruct, &node) != 0) {
log(LOG_ERR, "%s: can't %s for %s\n",
__FUNCTION__, "create node", name);
return;
}
/* Allocate private data */
MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT);
if (priv == NULL) {
log(LOG_ERR, "%s: can't %s for %s\n",
__FUNCTION__, "allocate memory", name);
ng_unref(node);
return;
}
bzero(priv, sizeof(*priv));
node->private = priv;
priv->ifp = ifp;
IFP2NG(ifp) = node;
priv->autoSrcAddr = 1;
priv->hwassist = ifp->if_hwassist;
/* Try to give the node the same name as the interface */
if (ng_name_node(node, name) != 0) {
log(LOG_WARNING, "%s: can't name node %s\n",
__FUNCTION__, name);
}
}
/*
* An Ethernet interface is being detached.
* Destroy its node.
*/
static void
ng_ether_detach(struct ifnet *ifp)
{
const node_p node = IFP2NG(ifp);
priv_p priv;
if (node == NULL) /* no node (why not?), ignore */
return;
ng_rmnode(node); /* break all links to other nodes */
node->flags |= NG_INVALID;
ng_unname(node); /* free name (and its reference) */
IFP2NG(ifp) = NULL; /* detach node from interface */
priv = node->private; /* free node private info */
bzero(priv, sizeof(*priv));
FREE(priv, M_NETGRAPH);
node->private = NULL;
ng_unref(node); /* free node itself */
}
/*
* Optimization for gluing the Ethernet header back onto
* the front of an incoming packet.
*/
static int
ng_ether_glueback_header(struct mbuf **mp, struct ether_header *eh)
{
struct mbuf *m = *mp;
int error = 0;
/*
* Optimize for the case where the header is already in place
* at the front of the mbuf. This is actually quite likely
* because many Ethernet drivers generate packets this way.
*/
if (eh == mtod(m, struct ether_header *) - 1) {
m->m_len += sizeof(*eh);
m->m_data -= sizeof(*eh);
m->m_pkthdr.len += sizeof(*eh);
goto done;
}
/* Prepend the header back onto the front of the mbuf */
M_PREPEND(m, sizeof(*eh), M_DONTWAIT);
if (m == NULL) {
error = ENOBUFS;
goto done;
}
/* Copy header into front of mbuf */
bcopy(eh, mtod(m, void *), sizeof(*eh));
done:
/* Done */
*mp = m;
return error;
}
/******************************************************************
NETGRAPH NODE METHODS
******************************************************************/
/*
* It is not possible or allowable to create a node of this type.
* Nodes get created when the interface is attached (or, when
* this node type's KLD is loaded).
*/
static int
ng_ether_constructor(node_p *nodep)
{
return (EINVAL);
}
/*
* Check for attaching a new hook.
*/
static int
ng_ether_newhook(node_p node, hook_p hook, const char *name)
{
const priv_p priv = node->private;
u_char orphan = priv->lowerOrphan;
hook_p *hookptr;
/* Divert hook is an alias for lower */
if (strcmp(name, NG_ETHER_HOOK_DIVERT) == 0)
name = NG_ETHER_HOOK_LOWER;
/* Which hook? */
if (strcmp(name, NG_ETHER_HOOK_UPPER) == 0)
hookptr = &priv->upper;
else if (strcmp(name, NG_ETHER_HOOK_LOWER) == 0) {
hookptr = &priv->lower;
orphan = 0;
} else if (strcmp(name, NG_ETHER_HOOK_ORPHAN) == 0) {
hookptr = &priv->lower;
orphan = 1;
} else
return (EINVAL);
/* Check if already connected (shouldn't be, but doesn't hurt) */
if (*hookptr != NULL)
return (EISCONN);
/* Disable hardware checksums while 'upper' hook is connected */
if (hookptr == &priv->upper)
priv->ifp->if_hwassist = 0;
/* OK */
*hookptr = hook;
priv->lowerOrphan = orphan;
return (0);
}
/*
* Receive an incoming control message.
*/
static int
ng_ether_rcvmsg(node_p node, struct ng_mesg *msg,
const char *retaddr, struct ng_mesg **rptr)
{
const priv_p priv = node->private;
struct ng_mesg *resp = NULL;
int error = 0;
switch (msg->header.typecookie) {
case NGM_ETHER_COOKIE:
switch (msg->header.cmd) {
case NGM_ETHER_GET_IFNAME:
NG_MKRESPONSE(resp, msg, IFNAMSIZ + 1, M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
snprintf(resp->data, IFNAMSIZ + 1,
"%s%d", priv->ifp->if_name, priv->ifp->if_unit);
break;
case NGM_ETHER_GET_IFINDEX:
NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
*((u_int32_t *)resp->data) = priv->ifp->if_index;
break;
case NGM_ETHER_GET_ENADDR:
NG_MKRESPONSE(resp, msg, ETHER_ADDR_LEN, M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
bcopy((IFP2AC(priv->ifp))->ac_enaddr,
resp->data, ETHER_ADDR_LEN);
break;
case NGM_ETHER_SET_ENADDR:
{
if (msg->header.arglen != ETHER_ADDR_LEN) {
error = EINVAL;
break;
}
error = if_setlladdr(priv->ifp,
(u_char *)msg->data, ETHER_ADDR_LEN);
break;
}
case NGM_ETHER_GET_PROMISC:
NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
*((u_int32_t *)resp->data) = priv->promisc;
break;
case NGM_ETHER_SET_PROMISC:
{
u_char want;
if (msg->header.arglen != sizeof(u_int32_t)) {
error = EINVAL;
break;
}
want = !!*((u_int32_t *)msg->data);
if (want ^ priv->promisc) {
if ((error = ifpromisc(priv->ifp, want)) != 0)
break;
priv->promisc = want;
}
break;
}
case NGM_ETHER_GET_AUTOSRC:
NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
if (resp == NULL) {
error = ENOMEM;
break;
}
*((u_int32_t *)resp->data) = priv->autoSrcAddr;
break;
case NGM_ETHER_SET_AUTOSRC:
if (msg->header.arglen != sizeof(u_int32_t)) {
error = EINVAL;
break;
}
priv->autoSrcAddr = !!*((u_int32_t *)msg->data);
break;
default:
error = EINVAL;
break;
}
break;
default:
error = EINVAL;
break;
}
if (rptr)
*rptr = resp;
else if (resp != NULL)
FREE(resp, M_NETGRAPH);
FREE(msg, M_NETGRAPH);
return (error);
}
/*
* Receive data on a hook.
*/
static int
ng_ether_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
{
const node_p node = hook->node;
const priv_p priv = node->private;
if (hook == priv->lower)
return ng_ether_rcv_lower(node, m, meta);
if (hook == priv->upper)
return ng_ether_rcv_upper(node, m, meta);
panic("%s: weird hook", __FUNCTION__);
}
/*
* Handle an mbuf received on the "lower" hook.
*/
static int
ng_ether_rcv_lower(node_p node, struct mbuf *m, meta_p meta)
{
const priv_p priv = node->private;
struct ifnet *const ifp = priv->ifp;
/* Discard meta info */
NG_FREE_META(meta);
/* Check whether interface is ready for packets */
if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
m_freem(m);
return (ENETDOWN);
}
/* Make sure header is fully pulled up */
if (m->m_pkthdr.len < sizeof(struct ether_header)) {
m_freem(m);
return (EINVAL);
}
if (m->m_len < sizeof(struct ether_header)
&& (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
return (ENOBUFS);
/* Drop in the MAC address if desired */
if (priv->autoSrcAddr) {
/* Make the mbuf writable if it's not already */
if (!M_WRITABLE(m)
&& (m = m_pullup(m, sizeof(struct ether_header))) == NULL)
return (ENOBUFS);
/* Overwrite source MAC address */
bcopy((IFP2AC(ifp))->ac_enaddr,
mtod(m, struct ether_header *)->ether_shost,
ETHER_ADDR_LEN);
}
/* Send it on its way */
return ether_output_frame(ifp, m);
}
/*
* Handle an mbuf received on the "upper" hook.
*/
static int
ng_ether_rcv_upper(node_p node, struct mbuf *m, meta_p meta)
{
const priv_p priv = node->private;
struct ether_header *eh;
/* Discard meta info */
NG_FREE_META(meta);
/* Check length and pull off header */
if (m->m_pkthdr.len < sizeof(*eh)) {
m_freem(m);
return (EINVAL);
}
if (m->m_len < sizeof(*eh) && (m = m_pullup(m, sizeof(*eh))) == NULL)
return (ENOBUFS);
eh = mtod(m, struct ether_header *);
m->m_data += sizeof(*eh);
m->m_len -= sizeof(*eh);
m->m_pkthdr.len -= sizeof(*eh);
m->m_pkthdr.rcvif = priv->ifp;
/* Route packet back in */
ether_demux(priv->ifp, eh, m);
return (0);
}
/*
* Shutdown node. This resets the node but does not remove it.
*/
static int
ng_ether_rmnode(node_p node)
{
const priv_p priv = node->private;
ng_cutlinks(node);
node->flags &= ~NG_INVALID; /* bounce back to life */
if (priv->promisc) { /* disable promiscuous mode */
(void)ifpromisc(priv->ifp, 0);
priv->promisc = 0;
}
priv->autoSrcAddr = 1; /* reset auto-src-addr flag */
return (0);
}
/*
* Hook disconnection.
*/
static int
ng_ether_disconnect(hook_p hook)
{
const priv_p priv = hook->node->private;
if (hook == priv->upper) {
priv->upper = NULL;
priv->ifp->if_hwassist = priv->hwassist; /* restore h/w csum */
} else if (hook == priv->lower) {
priv->lower = NULL;
priv->lowerOrphan = 0;
} else
panic("%s: weird hook", __FUNCTION__);
if (hook->node->numhooks == 0)
ng_rmnode(hook->node); /* reset node */
return (0);
}
/******************************************************************
INITIALIZATION
******************************************************************/
/*
* Handle loading and unloading for this node type.
*/
static int
ng_ether_mod_event(module_t mod, int event, void *data)
{
struct ifnet *ifp;
int error = 0;
int s;
s = splnet();
switch (event) {
case MOD_LOAD:
/* Register function hooks */
if (ng_ether_attach_p != NULL) {
error = EEXIST;
break;
}
ng_ether_attach_p = ng_ether_attach;
ng_ether_detach_p = ng_ether_detach;
ng_ether_output_p = ng_ether_output;
ng_ether_input_p = ng_ether_input;
ng_ether_input_orphan_p = ng_ether_input_orphan;
/* Create nodes for any already-existing Ethernet interfaces */
TAILQ_FOREACH(ifp, &ifnet, if_link) {
if (ifp->if_type == IFT_ETHER ||
ifp->if_type == IFT_L2VLAN)
ng_ether_attach(ifp);
}
break;
case MOD_UNLOAD:
/*
* Note that the base code won't try to unload us until
* all nodes have been removed, and that can't happen
* until all Ethernet interfaces are removed. In any
* case, we know there are no nodes left if the action
* is MOD_UNLOAD, so there's no need to detach any nodes.
*/
/* Unregister function hooks */
ng_ether_attach_p = NULL;
ng_ether_detach_p = NULL;
ng_ether_output_p = NULL;
ng_ether_input_p = NULL;
ng_ether_input_orphan_p = NULL;
break;
default:
error = EOPNOTSUPP;
break;
}
splx(s);
return (error);
}