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486 lines
13 KiB
C
486 lines
13 KiB
C
/*-
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* ng_etf.c Ethertype filter
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*/
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/*-
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* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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*
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* Copyright (c) 2001, FreeBSD Incorporated
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice unmodified, this list of conditions, and the following
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* disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* Author: Julian Elischer <julian@freebsd.org>
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*
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* $FreeBSD$
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/mbuf.h>
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#include <sys/malloc.h>
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#include <sys/ctype.h>
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#include <sys/errno.h>
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#include <sys/queue.h>
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#include <sys/syslog.h>
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#include <net/ethernet.h>
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#include <netgraph/ng_message.h>
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#include <netgraph/ng_parse.h>
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#include <netgraph/ng_etf.h>
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#include <netgraph/netgraph.h>
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/* If you do complicated mallocs you may want to do this */
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/* and use it for your mallocs */
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#ifdef NG_SEPARATE_MALLOC
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static MALLOC_DEFINE(M_NETGRAPH_ETF, "netgraph_etf", "netgraph etf node ");
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#else
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#define M_NETGRAPH_ETF M_NETGRAPH
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#endif
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/*
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* This section contains the netgraph method declarations for the
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* etf node. These methods define the netgraph 'type'.
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*/
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static ng_constructor_t ng_etf_constructor;
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static ng_rcvmsg_t ng_etf_rcvmsg;
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static ng_shutdown_t ng_etf_shutdown;
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static ng_newhook_t ng_etf_newhook;
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static ng_rcvdata_t ng_etf_rcvdata; /* note these are both ng_rcvdata_t */
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static ng_disconnect_t ng_etf_disconnect;
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/* Parse type for struct ng_etfstat */
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static const struct ng_parse_struct_field ng_etf_stat_type_fields[]
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= NG_ETF_STATS_TYPE_INFO;
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static const struct ng_parse_type ng_etf_stat_type = {
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&ng_parse_struct_type,
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&ng_etf_stat_type_fields
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};
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/* Parse type for struct ng_setfilter */
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static const struct ng_parse_struct_field ng_etf_filter_type_fields[]
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= NG_ETF_FILTER_TYPE_INFO;
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static const struct ng_parse_type ng_etf_filter_type = {
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&ng_parse_struct_type,
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&ng_etf_filter_type_fields
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};
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/* List of commands and how to convert arguments to/from ASCII */
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static const struct ng_cmdlist ng_etf_cmdlist[] = {
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{
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NGM_ETF_COOKIE,
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NGM_ETF_GET_STATUS,
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"getstatus",
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NULL,
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&ng_etf_stat_type,
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},
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{
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NGM_ETF_COOKIE,
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NGM_ETF_SET_FLAG,
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"setflag",
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&ng_parse_int32_type,
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NULL
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},
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{
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NGM_ETF_COOKIE,
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NGM_ETF_SET_FILTER,
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"setfilter",
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&ng_etf_filter_type,
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NULL
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},
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{ 0 }
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};
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/* Netgraph node type descriptor */
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static struct ng_type typestruct = {
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.version = NG_ABI_VERSION,
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.name = NG_ETF_NODE_TYPE,
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.constructor = ng_etf_constructor,
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.rcvmsg = ng_etf_rcvmsg,
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.shutdown = ng_etf_shutdown,
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.newhook = ng_etf_newhook,
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.rcvdata = ng_etf_rcvdata,
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.disconnect = ng_etf_disconnect,
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.cmdlist = ng_etf_cmdlist,
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};
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NETGRAPH_INIT(etf, &typestruct);
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/* Information we store for each hook on each node */
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struct ETF_hookinfo {
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hook_p hook;
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};
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struct filter {
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LIST_ENTRY(filter) next;
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u_int16_t ethertype; /* network order ethertype */
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hook_p match_hook; /* Hook to use on a match */
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};
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#define HASHSIZE 16 /* Dont change this without changing HASH() */
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#define HASH(et) ((((et)>>12)+((et)>>8)+((et)>>4)+(et)) & 0x0f)
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LIST_HEAD(filterhead, filter);
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/* Information we store for each node */
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struct ETF {
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struct ETF_hookinfo downstream_hook;
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struct ETF_hookinfo nomatch_hook;
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node_p node; /* back pointer to node */
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u_int packets_in; /* packets in from downstream */
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u_int packets_out; /* packets out towards downstream */
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u_int32_t flags;
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struct filterhead hashtable[HASHSIZE];
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};
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typedef struct ETF *etf_p;
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static struct filter *
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ng_etf_findentry(etf_p etfp, u_int16_t ethertype)
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{
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struct filterhead *chain = etfp->hashtable + HASH(ethertype);
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struct filter *fil;
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LIST_FOREACH(fil, chain, next) {
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if (fil->ethertype == ethertype) {
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return (fil);
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}
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}
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return (NULL);
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}
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/*
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* Allocate the private data structure. The generic node has already
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* been created. Link them together. We arrive with a reference to the node
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* i.e. the reference count is incremented for us already.
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*/
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static int
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ng_etf_constructor(node_p node)
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{
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etf_p privdata;
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int i;
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/* Initialize private descriptor */
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privdata = malloc(sizeof(*privdata), M_NETGRAPH_ETF, M_WAITOK | M_ZERO);
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for (i = 0; i < HASHSIZE; i++) {
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LIST_INIT((privdata->hashtable + i));
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}
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/* Link structs together; this counts as our one reference to node */
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NG_NODE_SET_PRIVATE(node, privdata);
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privdata->node = node;
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return (0);
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}
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/*
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* Give our ok for a hook to be added...
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* All names are ok. Two names are special.
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*/
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static int
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ng_etf_newhook(node_p node, hook_p hook, const char *name)
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{
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const etf_p etfp = NG_NODE_PRIVATE(node);
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struct ETF_hookinfo *hpriv;
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if (strcmp(name, NG_ETF_HOOK_DOWNSTREAM) == 0) {
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etfp->downstream_hook.hook = hook;
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NG_HOOK_SET_PRIVATE(hook, &etfp->downstream_hook);
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etfp->packets_in = 0;
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etfp->packets_out = 0;
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} else if (strcmp(name, NG_ETF_HOOK_NOMATCH) == 0) {
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etfp->nomatch_hook.hook = hook;
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NG_HOOK_SET_PRIVATE(hook, &etfp->nomatch_hook);
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} else {
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/*
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* Any other hook name is valid and can
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* later be associated with a filter rule.
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*/
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hpriv = malloc(sizeof(*hpriv),
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M_NETGRAPH_ETF, M_NOWAIT | M_ZERO);
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if (hpriv == NULL) {
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return (ENOMEM);
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}
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NG_HOOK_SET_PRIVATE(hook, hpriv);
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hpriv->hook = hook;
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}
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return(0);
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}
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/*
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* Get a netgraph control message.
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* We actually receive a queue item that has a pointer to the message.
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* If we free the item, the message will be freed too, unless we remove
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* it from the item using NGI_GET_MSG();
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* The return address is also stored in the item, as an ng_ID_t,
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* accessible as NGI_RETADDR(item);
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* Check it is one we understand. If needed, send a response.
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* We could save the address for an async action later, but don't here.
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* Always free the message.
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* The response should be in a malloc'd region that the caller can 'free'.
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* The NG_MKRESPONSE macro does all this for us.
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* A response is not required.
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* Theoretically you could respond defferently to old message types if
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* the cookie in the header didn't match what we consider to be current
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* (so that old userland programs could continue to work).
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*/
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static int
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ng_etf_rcvmsg(node_p node, item_p item, hook_p lasthook)
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{
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const etf_p etfp = NG_NODE_PRIVATE(node);
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struct ng_mesg *resp = NULL;
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int error = 0;
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struct ng_mesg *msg;
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NGI_GET_MSG(item, msg);
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/* Deal with message according to cookie and command */
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switch (msg->header.typecookie) {
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case NGM_ETF_COOKIE:
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switch (msg->header.cmd) {
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case NGM_ETF_GET_STATUS:
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{
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struct ng_etfstat *stats;
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NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
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if (!resp) {
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error = ENOMEM;
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break;
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}
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stats = (struct ng_etfstat *) resp->data;
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stats->packets_in = etfp->packets_in;
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stats->packets_out = etfp->packets_out;
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break;
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}
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case NGM_ETF_SET_FLAG:
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if (msg->header.arglen != sizeof(u_int32_t)) {
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error = EINVAL;
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break;
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}
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etfp->flags = *((u_int32_t *) msg->data);
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break;
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case NGM_ETF_SET_FILTER:
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{
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struct ng_etffilter *f;
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struct filter *fil;
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hook_p hook;
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/* Check message long enough for this command */
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if (msg->header.arglen != sizeof(*f)) {
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error = EINVAL;
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break;
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}
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/* Make sure hook referenced exists */
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f = (struct ng_etffilter *)msg->data;
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hook = ng_findhook(node, f->matchhook);
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if (hook == NULL) {
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error = ENOENT;
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break;
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}
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/* and is not the downstream hook */
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if (hook == etfp->downstream_hook.hook) {
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error = EINVAL;
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break;
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}
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/* Check we don't already trap this ethertype */
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if (ng_etf_findentry(etfp,
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htons(f->ethertype))) {
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error = EEXIST;
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break;
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}
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/*
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* Ok, make the filter and put it in the
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* hashtable ready for matching.
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*/
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fil = malloc(sizeof(*fil),
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M_NETGRAPH_ETF, M_NOWAIT | M_ZERO);
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if (fil == NULL) {
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error = ENOMEM;
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break;
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}
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fil->match_hook = hook;
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fil->ethertype = htons(f->ethertype);
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LIST_INSERT_HEAD( etfp->hashtable
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+ HASH(fil->ethertype),
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fil, next);
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}
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break;
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default:
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error = EINVAL; /* unknown command */
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break;
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}
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break;
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default:
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error = EINVAL; /* unknown cookie type */
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break;
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}
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/* Take care of synchronous response, if any */
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NG_RESPOND_MSG(error, node, item, resp);
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/* Free the message and return */
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NG_FREE_MSG(msg);
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return(error);
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}
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/*
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* Receive data, and do something with it.
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* Actually we receive a queue item which holds the data.
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* If we free the item it will also free the data unless we have previously
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* disassociated it using the NGI_GET_etf() macro.
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* Possibly send it out on another link after processing.
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* Possibly do something different if it comes from different
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* hooks. The caller will never free m , so if we use up this data
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* or abort we must free it.
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*
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* If we want, we may decide to force this data to be queued and reprocessed
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* at the netgraph NETISR time.
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* We would do that by setting the HK_QUEUE flag on our hook. We would do that
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* in the connect() method.
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*/
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static int
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ng_etf_rcvdata(hook_p hook, item_p item )
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{
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const etf_p etfp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
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struct ether_header *eh;
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int error = 0;
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struct mbuf *m;
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u_int16_t ethertype;
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struct filter *fil;
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if (NG_HOOK_PRIVATE(hook) == NULL) { /* Shouldn't happen but.. */
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NG_FREE_ITEM(item);
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}
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/*
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* Everything not from the downstream hook goes to the
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* downstream hook. But only if it matches the ethertype
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* of the source hook. Un matching must go to/from 'nomatch'.
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*/
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/* Make sure we have an entire header */
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NGI_GET_M(item, m);
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if (m->m_len < sizeof(*eh) ) {
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m = m_pullup(m, sizeof(*eh));
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if (m == NULL) {
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NG_FREE_ITEM(item);
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return(EINVAL);
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}
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}
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eh = mtod(m, struct ether_header *);
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ethertype = eh->ether_type;
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fil = ng_etf_findentry(etfp, ethertype);
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/*
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* if from downstream, select between a match hook or
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* the nomatch hook
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*/
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if (hook == etfp->downstream_hook.hook) {
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etfp->packets_in++;
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if (fil && fil->match_hook) {
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NG_FWD_NEW_DATA(error, item, fil->match_hook, m);
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} else {
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NG_FWD_NEW_DATA(error, item,etfp->nomatch_hook.hook, m);
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}
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} else {
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/*
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* It must be heading towards the downstream.
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* Check that it's ethertype matches
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* the filters for it's input hook.
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* If it doesn't have one, check it's from nomatch.
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*/
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if ((fil && (fil->match_hook != hook))
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|| ((fil == NULL) && (hook != etfp->nomatch_hook.hook))) {
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NG_FREE_ITEM(item);
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NG_FREE_M(m);
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return (EPROTOTYPE);
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}
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NG_FWD_NEW_DATA( error, item, etfp->downstream_hook.hook, m);
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if (error == 0) {
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etfp->packets_out++;
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}
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}
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return (error);
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}
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/*
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* Do local shutdown processing..
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* All our links and the name have already been removed.
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*/
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static int
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ng_etf_shutdown(node_p node)
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{
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const etf_p privdata = NG_NODE_PRIVATE(node);
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NG_NODE_SET_PRIVATE(node, NULL);
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NG_NODE_UNREF(privdata->node);
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free(privdata, M_NETGRAPH_ETF);
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return (0);
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}
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/*
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* Hook disconnection
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*
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* For this type, removal of the last link destroys the node
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*/
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static int
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ng_etf_disconnect(hook_p hook)
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{
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const etf_p etfp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
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int i;
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struct filter *fil1, *fil2;
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/* purge any rules that refer to this filter */
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for (i = 0; i < HASHSIZE; i++) {
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fil1 = LIST_FIRST(&etfp->hashtable[i]);
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while (fil1 != NULL) {
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fil2 = LIST_NEXT(fil1, next);
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if (fil1->match_hook == hook) {
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LIST_REMOVE(fil1, next);
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free(fil1, M_NETGRAPH_ETF);
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}
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fil1 = fil2;
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}
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}
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/* If it's not one of the special hooks, then free it */
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if (hook == etfp->downstream_hook.hook) {
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etfp->downstream_hook.hook = NULL;
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} else if (hook == etfp->nomatch_hook.hook) {
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etfp->nomatch_hook.hook = NULL;
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} else {
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if (NG_HOOK_PRIVATE(hook)) /* Paranoia */
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free(NG_HOOK_PRIVATE(hook), M_NETGRAPH_ETF);
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}
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NG_HOOK_SET_PRIVATE(hook, NULL);
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if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
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&& (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) /* already shutting down? */
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ng_rmnode_self(NG_HOOK_NODE(hook));
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return (0);
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}
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