bf2394b8d4
addresses to be the more usefu @freebsd.org ones so we can keep getting bug-reports. - man pages to follow..
504 lines
12 KiB
C
504 lines
12 KiB
C
|
|
/*
|
|
* ng_bpf.c
|
|
*
|
|
* Copyright (c) 1999 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, GUARANBPF, 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.
|
|
*
|
|
* Author: Archie Cobbs <archie@freebsd.org>
|
|
*
|
|
* $FreeBSD$
|
|
* $Whistle: ng_bpf.c,v 1.3 1999/12/03 20:30:23 archie Exp $
|
|
*/
|
|
|
|
/*
|
|
* BPF NETGRAPH NODE TYPE
|
|
*
|
|
* This node type accepts any number of hook connections. With each hook
|
|
* is associated a bpf(4) filter program, and two hook names (each possibly
|
|
* the empty string). Incoming packets are compared against the filter;
|
|
* matching packets are delivered out the first named hook (or dropped if
|
|
* the empty string), and non-matching packets are delivered out the second
|
|
* named hook (or dropped if the empty string).
|
|
*
|
|
* Each hook also keeps statistics about how many packets have matched, etc.
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/errno.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
|
|
#include <net/bpf.h>
|
|
|
|
#include <netgraph/ng_message.h>
|
|
#include <netgraph/netgraph.h>
|
|
#include <netgraph/ng_parse.h>
|
|
#include <netgraph/ng_bpf.h>
|
|
|
|
#define OFFSETOF(s, e) ((char *)&((s *)0)->e - (char *)((s *)0))
|
|
|
|
#define ERROUT(x) do { error = (x); goto done; } while (0)
|
|
|
|
/* Per hook private info */
|
|
struct ng_bpf_hookinfo {
|
|
node_p node;
|
|
hook_p hook;
|
|
struct ng_bpf_hookprog *prog;
|
|
struct ng_bpf_hookstat stats;
|
|
};
|
|
typedef struct ng_bpf_hookinfo *hinfo_p;
|
|
|
|
/* Netgraph methods */
|
|
static ng_constructor_t ng_bpf_constructor;
|
|
static ng_rcvmsg_t ng_bpf_rcvmsg;
|
|
static ng_shutdown_t ng_bpf_rmnode;
|
|
static ng_newhook_t ng_bpf_newhook;
|
|
static ng_rcvdata_t ng_bpf_rcvdata;
|
|
static ng_disconnect_t ng_bpf_disconnect;
|
|
|
|
/* Internal helper functions */
|
|
static int ng_bpf_setprog(hook_p hook, const struct ng_bpf_hookprog *hp);
|
|
|
|
/* Parse type for one struct bfp_insn */
|
|
static const struct ng_parse_struct_info ng_bpf_insn_type_info = {
|
|
{
|
|
{ "code", &ng_parse_hint16_type },
|
|
{ "jt", &ng_parse_uint8_type },
|
|
{ "jf", &ng_parse_uint8_type },
|
|
{ "k", &ng_parse_uint32_type },
|
|
{ NULL }
|
|
}
|
|
};
|
|
static const struct ng_parse_type ng_bpf_insn_type = {
|
|
&ng_parse_struct_type,
|
|
&ng_bpf_insn_type_info
|
|
};
|
|
|
|
/* Parse type for the field 'bpf_prog' in struct ng_bpf_hookprog */
|
|
static int
|
|
ng_bpf_hookprogary_getLength(const struct ng_parse_type *type,
|
|
const u_char *start, const u_char *buf)
|
|
{
|
|
const struct ng_bpf_hookprog *hp;
|
|
|
|
hp = (const struct ng_bpf_hookprog *)
|
|
(buf - OFFSETOF(struct ng_bpf_hookprog, bpf_prog));
|
|
return hp->bpf_prog_len;
|
|
}
|
|
|
|
static const struct ng_parse_array_info ng_bpf_hookprogary_info = {
|
|
&ng_bpf_insn_type,
|
|
&ng_bpf_hookprogary_getLength,
|
|
NULL
|
|
};
|
|
static const struct ng_parse_type ng_bpf_hookprogary_type = {
|
|
&ng_parse_array_type,
|
|
&ng_bpf_hookprogary_info
|
|
};
|
|
|
|
/* Parse type for struct ng_bpf_hookprog */
|
|
static const struct ng_parse_struct_info ng_bpf_hookprog_type_info
|
|
= NG_BPF_HOOKPROG_TYPE_INFO(&ng_bpf_hookprogary_type);
|
|
static const struct ng_parse_type ng_bpf_hookprog_type = {
|
|
&ng_parse_struct_type,
|
|
&ng_bpf_hookprog_type_info
|
|
};
|
|
|
|
/* Parse type for struct ng_bpf_hookstat */
|
|
static const struct ng_parse_struct_info
|
|
ng_bpf_hookstat_type_info = NG_BPF_HOOKSTAT_TYPE_INFO;
|
|
static const struct ng_parse_type ng_bpf_hookstat_type = {
|
|
&ng_parse_struct_type,
|
|
&ng_bpf_hookstat_type_info
|
|
};
|
|
|
|
/* List of commands and how to convert arguments to/from ASCII */
|
|
static const struct ng_cmdlist ng_bpf_cmdlist[] = {
|
|
{
|
|
NGM_BPF_COOKIE,
|
|
NGM_BPF_SET_PROGRAM,
|
|
"setprogram",
|
|
&ng_bpf_hookprog_type,
|
|
NULL
|
|
},
|
|
{
|
|
NGM_BPF_COOKIE,
|
|
NGM_BPF_GET_PROGRAM,
|
|
"getprogram",
|
|
&ng_parse_hookbuf_type,
|
|
&ng_bpf_hookprog_type
|
|
},
|
|
{
|
|
NGM_BPF_COOKIE,
|
|
NGM_BPF_GET_STATS,
|
|
"getstats",
|
|
&ng_parse_hookbuf_type,
|
|
&ng_bpf_hookstat_type
|
|
},
|
|
{
|
|
NGM_BPF_COOKIE,
|
|
NGM_BPF_CLR_STATS,
|
|
"clrstats",
|
|
&ng_parse_hookbuf_type,
|
|
NULL
|
|
},
|
|
{
|
|
NGM_BPF_COOKIE,
|
|
NGM_BPF_GETCLR_STATS,
|
|
"getclrstats",
|
|
&ng_parse_hookbuf_type,
|
|
&ng_bpf_hookstat_type
|
|
},
|
|
{ 0 }
|
|
};
|
|
|
|
/* Netgraph type descriptor */
|
|
static struct ng_type typestruct = {
|
|
NG_VERSION,
|
|
NG_BPF_NODE_TYPE,
|
|
NULL,
|
|
ng_bpf_constructor,
|
|
ng_bpf_rcvmsg,
|
|
ng_bpf_rmnode,
|
|
ng_bpf_newhook,
|
|
NULL,
|
|
NULL,
|
|
ng_bpf_rcvdata,
|
|
ng_bpf_rcvdata,
|
|
ng_bpf_disconnect,
|
|
ng_bpf_cmdlist
|
|
};
|
|
NETGRAPH_INIT(bpf, &typestruct);
|
|
|
|
/* Default BPF program for a hook that matches nothing */
|
|
static const struct ng_bpf_hookprog ng_bpf_default_prog = {
|
|
{ '\0' }, /* to be filled in at hook creation time */
|
|
{ '\0' },
|
|
{ '\0' },
|
|
1,
|
|
{ BPF_STMT(BPF_RET+BPF_K, 0) }
|
|
};
|
|
|
|
/*
|
|
* Node constructor
|
|
*
|
|
* We don't keep any per-node private data
|
|
*/
|
|
static int
|
|
ng_bpf_constructor(node_p *nodep)
|
|
{
|
|
int error = 0;
|
|
|
|
if ((error = ng_make_node_common(&typestruct, nodep)))
|
|
return (error);
|
|
(*nodep)->private = NULL;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Add a hook
|
|
*/
|
|
static int
|
|
ng_bpf_newhook(node_p node, hook_p hook, const char *name)
|
|
{
|
|
hinfo_p hip;
|
|
int error;
|
|
|
|
/* Create hook private structure */
|
|
MALLOC(hip, hinfo_p, sizeof(*hip), M_NETGRAPH, M_NOWAIT);
|
|
if (hip == NULL)
|
|
return (ENOMEM);
|
|
bzero(hip, sizeof(*hip));
|
|
hip->hook = hook;
|
|
hook->private = hip;
|
|
hip->node = node;
|
|
|
|
/* Attach the default BPF program */
|
|
if ((error = ng_bpf_setprog(hook, &ng_bpf_default_prog)) != 0) {
|
|
FREE(hip, M_NETGRAPH);
|
|
hook->private = NULL;
|
|
return (error);
|
|
}
|
|
|
|
/* Set hook name */
|
|
strncpy(hip->prog->thisHook, name, sizeof(hip->prog->thisHook) - 1);
|
|
hip->prog->thisHook[sizeof(hip->prog->thisHook) - 1] = '\0';
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Receive a control message
|
|
*/
|
|
static int
|
|
ng_bpf_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
|
|
struct ng_mesg **rptr, hook_p lasthook)
|
|
{
|
|
struct ng_mesg *resp = NULL;
|
|
int error = 0;
|
|
|
|
switch (msg->header.typecookie) {
|
|
case NGM_BPF_COOKIE:
|
|
switch (msg->header.cmd) {
|
|
case NGM_BPF_SET_PROGRAM:
|
|
{
|
|
struct ng_bpf_hookprog *const
|
|
hp = (struct ng_bpf_hookprog *)msg->data;
|
|
hook_p hook;
|
|
|
|
/* Sanity check */
|
|
if (msg->header.arglen < sizeof(*hp)
|
|
|| msg->header.arglen
|
|
!= NG_BPF_HOOKPROG_SIZE(hp->bpf_prog_len))
|
|
ERROUT(EINVAL);
|
|
|
|
/* Find hook */
|
|
if ((hook = ng_findhook(node, hp->thisHook)) == NULL)
|
|
ERROUT(ENOENT);
|
|
|
|
/* Set new program */
|
|
if ((error = ng_bpf_setprog(hook, hp)) != 0)
|
|
ERROUT(error);
|
|
break;
|
|
}
|
|
|
|
case NGM_BPF_GET_PROGRAM:
|
|
{
|
|
struct ng_bpf_hookprog *hp;
|
|
hook_p hook;
|
|
|
|
/* Sanity check */
|
|
if (msg->header.arglen == 0)
|
|
ERROUT(EINVAL);
|
|
msg->data[msg->header.arglen - 1] = '\0';
|
|
|
|
/* Find hook */
|
|
if ((hook = ng_findhook(node, msg->data)) == NULL)
|
|
ERROUT(ENOENT);
|
|
|
|
/* Build response */
|
|
hp = ((hinfo_p)hook->private)->prog;
|
|
NG_MKRESPONSE(resp, msg,
|
|
NG_BPF_HOOKPROG_SIZE(hp->bpf_prog_len), M_NOWAIT);
|
|
if (resp == NULL)
|
|
ERROUT(ENOMEM);
|
|
bcopy(hp, resp->data,
|
|
NG_BPF_HOOKPROG_SIZE(hp->bpf_prog_len));
|
|
break;
|
|
}
|
|
|
|
case NGM_BPF_GET_STATS:
|
|
case NGM_BPF_CLR_STATS:
|
|
case NGM_BPF_GETCLR_STATS:
|
|
{
|
|
struct ng_bpf_hookstat *stats;
|
|
hook_p hook;
|
|
|
|
/* Sanity check */
|
|
if (msg->header.arglen == 0)
|
|
ERROUT(EINVAL);
|
|
msg->data[msg->header.arglen - 1] = '\0';
|
|
|
|
/* Find hook */
|
|
if ((hook = ng_findhook(node, msg->data)) == NULL)
|
|
ERROUT(ENOENT);
|
|
stats = &((hinfo_p)hook->private)->stats;
|
|
|
|
/* Build response (if desired) */
|
|
if (msg->header.cmd != NGM_BPF_CLR_STATS) {
|
|
NG_MKRESPONSE(resp,
|
|
msg, sizeof(*stats), M_NOWAIT);
|
|
if (resp == NULL)
|
|
ERROUT(ENOMEM);
|
|
bcopy(stats, resp->data, sizeof(*stats));
|
|
}
|
|
|
|
/* Clear stats (if desired) */
|
|
if (msg->header.cmd != NGM_BPF_GET_STATS)
|
|
bzero(stats, sizeof(*stats));
|
|
break;
|
|
}
|
|
|
|
default:
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
break;
|
|
default:
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
if (rptr)
|
|
*rptr = resp;
|
|
else if (resp)
|
|
FREE(resp, M_NETGRAPH);
|
|
|
|
done:
|
|
FREE(msg, M_NETGRAPH);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Receive data on a hook
|
|
*
|
|
* Apply the filter, and then drop or forward packet as appropriate.
|
|
*/
|
|
static int
|
|
ng_bpf_rcvdata(hook_p hook, struct mbuf *m, meta_p meta,
|
|
struct mbuf **ret_m, meta_p *ret_meta)
|
|
{
|
|
const hinfo_p hip = hook->private;
|
|
int totlen = m->m_pkthdr.len;
|
|
int needfree = 0, error = 0;
|
|
u_char *data, buf[256];
|
|
hinfo_p dhip;
|
|
hook_p dest;
|
|
u_int len;
|
|
|
|
/* Update stats on incoming hook */
|
|
hip->stats.recvFrames++;
|
|
hip->stats.recvOctets += totlen;
|
|
|
|
/* Need to put packet in contiguous memory for bpf */
|
|
if (m->m_next != NULL) {
|
|
if (totlen > sizeof(buf)) {
|
|
MALLOC(data, u_char *, totlen, M_NETGRAPH, M_NOWAIT);
|
|
if (data == NULL) {
|
|
NG_FREE_DATA(m, meta);
|
|
return (ENOMEM);
|
|
}
|
|
needfree = 1;
|
|
} else
|
|
data = buf;
|
|
m_copydata(m, 0, totlen, (caddr_t)data);
|
|
} else
|
|
data = mtod(m, u_char *);
|
|
|
|
/* Run packet through filter */
|
|
len = bpf_filter(hip->prog->bpf_prog, data, totlen, totlen);
|
|
if (needfree)
|
|
FREE(data, M_NETGRAPH);
|
|
|
|
/* See if we got a match and find destination hook */
|
|
if (len > 0) {
|
|
|
|
/* Update stats */
|
|
hip->stats.recvMatchFrames++;
|
|
hip->stats.recvMatchOctets += totlen;
|
|
|
|
/* Truncate packet length if required by the filter */
|
|
if (len < totlen) {
|
|
m_adj(m, -(totlen - len));
|
|
totlen -= len;
|
|
}
|
|
dest = ng_findhook(hip->node, hip->prog->ifMatch);
|
|
} else
|
|
dest = ng_findhook(hip->node, hip->prog->ifNotMatch);
|
|
if (dest == NULL) {
|
|
NG_FREE_DATA(m, meta);
|
|
return (0);
|
|
}
|
|
|
|
/* Deliver frame out destination hook */
|
|
dhip = (hinfo_p)dest->private;
|
|
dhip->stats.xmitOctets += totlen;
|
|
dhip->stats.xmitFrames++;
|
|
NG_SEND_DATA(error, dest, m, meta);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Shutdown processing
|
|
*/
|
|
static int
|
|
ng_bpf_rmnode(node_p node)
|
|
{
|
|
node->flags |= NG_INVALID;
|
|
ng_cutlinks(node);
|
|
ng_unname(node);
|
|
ng_unref(node);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Hook disconnection
|
|
*/
|
|
static int
|
|
ng_bpf_disconnect(hook_p hook)
|
|
{
|
|
const hinfo_p hip = hook->private;
|
|
|
|
KASSERT(hip != NULL, ("%s: null info", __FUNCTION__));
|
|
FREE(hip->prog, M_NETGRAPH);
|
|
bzero(hip, sizeof(*hip));
|
|
FREE(hip, M_NETGRAPH);
|
|
hook->private = NULL; /* for good measure */
|
|
if (hook->node->numhooks == 0)
|
|
ng_rmnode(hook->node);
|
|
return (0);
|
|
}
|
|
|
|
/************************************************************************
|
|
HELPER STUFF
|
|
************************************************************************/
|
|
|
|
/*
|
|
* Set the BPF program associated with a hook
|
|
*/
|
|
static int
|
|
ng_bpf_setprog(hook_p hook, const struct ng_bpf_hookprog *hp0)
|
|
{
|
|
const hinfo_p hip = hook->private;
|
|
struct ng_bpf_hookprog *hp;
|
|
int size;
|
|
|
|
/* Check program for validity */
|
|
if (!bpf_validate(hp0->bpf_prog, hp0->bpf_prog_len))
|
|
return (EINVAL);
|
|
|
|
/* Make a copy of the program */
|
|
size = NG_BPF_HOOKPROG_SIZE(hp0->bpf_prog_len);
|
|
MALLOC(hp, struct ng_bpf_hookprog *, size, M_NETGRAPH, M_NOWAIT);
|
|
if (hp == NULL)
|
|
return (ENOMEM);
|
|
bcopy(hp0, hp, size);
|
|
|
|
/* Free previous program, if any, and assign new one */
|
|
if (hip->prog != NULL)
|
|
FREE(hip->prog, M_NETGRAPH);
|
|
hip->prog = hp;
|
|
return (0);
|
|
}
|
|
|