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npf_ext_log.c revision 1.8 
      1 /*	$NetBSD: npf_ext_log.c,v 1.8 2014/07/20 00:37:41 rmind Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2010-2012 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This material is based upon work partially supported by The
      8  * NetBSD Foundation under a contract with Mindaugas Rasiukevicius.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * NPF logging extension.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 __KERNEL_RCSID(0, "$NetBSD: npf_ext_log.c,v 1.8 2014/07/20 00:37:41 rmind Exp $");
     38 
     39 #include <sys/types.h>
     40 #include <sys/module.h>
     41 
     42 #include <sys/conf.h>
     43 #include <sys/kmem.h>
     44 #include <sys/mbuf.h>
     45 #include <sys/mutex.h>
     46 #include <sys/queue.h>
     47 
     48 #include <net/if.h>
     49 #include <net/if_types.h>
     50 #include <net/bpf.h>
     51 
     52 #include "npf_impl.h"
     53 
     54 NPF_EXT_MODULE(npf_ext_log, "");
     55 
     56 #define	NPFEXT_LOG_VER		1
     57 
     58 static void *		npf_ext_log_id;
     59 
     60 typedef struct {
     61 	unsigned int	if_idx;
     62 } npf_ext_log_t;
     63 
     64 static int
     65 npf_log_ctor(npf_rproc_t *rp, prop_dictionary_t params)
     66 {
     67 	npf_ext_log_t *meta;
     68 
     69 	meta = kmem_zalloc(sizeof(npf_ext_log_t), KM_SLEEP);
     70 	prop_dictionary_get_uint32(params, "log-interface", &meta->if_idx);
     71 	npf_rproc_assign(rp, meta);
     72 	return 0;
     73 }
     74 
     75 static void
     76 npf_log_dtor(npf_rproc_t *rp, void *meta)
     77 {
     78 	kmem_free(meta, sizeof(npf_ext_log_t));
     79 }
     80 
     81 static bool
     82 npf_log(npf_cache_t *npc, void *meta, int *decision)
     83 {
     84 	struct mbuf *m = nbuf_head_mbuf(npc->npc_nbuf);
     85 	const npf_ext_log_t *log = meta;
     86 	ifnet_t *ifp;
     87 	int family;
     88 
     89 	/* Set the address family. */
     90 	if (npf_iscached(npc, NPC_IP4)) {
     91 		family = AF_INET;
     92 	} else if (npf_iscached(npc, NPC_IP6)) {
     93 		family = AF_INET6;
     94 	} else {
     95 		family = AF_UNSPEC;
     96 	}
     97 
     98 	KERNEL_LOCK(1, NULL);
     99 
    100 	/* Find a pseudo-interface to log. */
    101 	ifp = if_byindex(log->if_idx);
    102 	if (ifp == NULL) {
    103 		/* No interface. */
    104 		KERNEL_UNLOCK_ONE(NULL);
    105 		return true;
    106 	}
    107 
    108 	/* Pass through BPF. */
    109 	ifp->if_opackets++;
    110 	ifp->if_obytes += m->m_pkthdr.len;
    111 	bpf_mtap_af(ifp, family, m);
    112 	KERNEL_UNLOCK_ONE(NULL);
    113 
    114 	return true;
    115 }
    116 
    117 /*
    118  * Module interface.
    119  */
    120 static int
    121 npf_ext_log_modcmd(modcmd_t cmd, void *arg)
    122 {
    123 	static const npf_ext_ops_t npf_log_ops = {
    124 		.version	= NPFEXT_LOG_VER,
    125 		.ctx		= NULL,
    126 		.ctor		= npf_log_ctor,
    127 		.dtor		= npf_log_dtor,
    128 		.proc		= npf_log
    129 	};
    130 	int error;
    131 
    132 	switch (cmd) {
    133 	case MODULE_CMD_INIT:
    134 		/*
    135 		 * Initialise the NPF logging extension.
    136 		 */
    137 		npf_ext_log_id = npf_ext_register("log", &npf_log_ops);
    138 		if (!npf_ext_log_id) {
    139 			return EEXIST;
    140 		}
    141 		break;
    142 
    143 	case MODULE_CMD_FINI:
    144 		error = npf_ext_unregister(npf_ext_log_id);
    145 		if (error) {
    146 			return error;
    147 		}
    148 		break;
    149 
    150 	case MODULE_CMD_AUTOUNLOAD:
    151 		/* Allow auto-unload only if NPF permits it. */
    152 		return npf_autounload_p() ? 0 : EBUSY;
    153 
    154 	default:
    155 		return ENOTTY;
    156 	}
    157 	return 0;
    158 }
    159