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npf_rproc.c revision 1.1.4.2 
      1 /*	$NetBSD: npf_rproc.c,v 1.1.4.2 2012/02/18 07:35:38 mrg Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2009-2012 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 rule procedure interface.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 __KERNEL_RCSID(0, "$NetBSD");
     38 
     39 #include <sys/param.h>
     40 #include <sys/kernel.h>
     41 
     42 #include <sys/atomic.h>
     43 #include <sys/kmem.h>
     44 #include <sys/types.h>
     45 
     46 #include "npf_impl.h"
     47 
     48 #define	NPF_RNAME_LEN		16
     49 
     50 /* Rule procedure structure. */
     51 struct npf_rproc {
     52 	/* Name. */
     53 	char			rp_name[NPF_RNAME_LEN];
     54 	/* Reference count. */
     55 	u_int			rp_refcnt;
     56 	uint32_t		rp_flags;
     57 	/* Normalisation options. */
     58 	bool			rp_rnd_ipid;
     59 	bool			rp_no_df;
     60 	u_int			rp_minttl;
     61 	u_int			rp_maxmss;
     62 	/* Logging interface. */
     63 	u_int			rp_log_ifid;
     64 };
     65 
     66 npf_rproc_t *
     67 npf_rproc_create(prop_dictionary_t rpdict)
     68 {
     69 	npf_rproc_t *rp;
     70 	const char *rname;
     71 
     72 	rp = kmem_zalloc(sizeof(npf_rproc_t), KM_SLEEP);
     73 	rp->rp_refcnt = 1;
     74 
     75 	/* Name and flags. */
     76 	prop_dictionary_get_cstring_nocopy(rpdict, "name", &rname);
     77 	strlcpy(rp->rp_name, rname, NPF_RNAME_LEN);
     78 	prop_dictionary_get_uint32(rpdict, "flags", &rp->rp_flags);
     79 
     80 	/* Logging interface ID (integer). */
     81 	prop_dictionary_get_uint32(rpdict, "log-interface", &rp->rp_log_ifid);
     82 
     83 	/* IP ID randomisation and IP_DF flag cleansing. */
     84 	prop_dictionary_get_bool(rpdict, "randomize-id", &rp->rp_rnd_ipid);
     85 	prop_dictionary_get_bool(rpdict, "no-df", &rp->rp_no_df);
     86 
     87 	/* Minimum IP TTL and maximum TCP MSS. */
     88 	prop_dictionary_get_uint32(rpdict, "min-ttl", &rp->rp_minttl);
     89 	prop_dictionary_get_uint32(rpdict, "max-mss", &rp->rp_maxmss);
     90 
     91 	return rp;
     92 }
     93 
     94 void
     95 npf_rproc_acquire(npf_rproc_t *rp)
     96 {
     97 
     98 	atomic_inc_uint(&rp->rp_refcnt);
     99 }
    100 
    101 void
    102 npf_rproc_release(npf_rproc_t *rp)
    103 {
    104 
    105 	/* Destroy on last reference. */
    106 	KASSERT(rp->rp_refcnt > 0);
    107 	if (atomic_dec_uint_nv(&rp->rp_refcnt) != 0) {
    108 		return;
    109 	}
    110 	kmem_free(rp, sizeof(npf_rproc_t));
    111 }
    112 
    113 void
    114 npf_rproc_run(npf_cache_t *npc, nbuf_t *nbuf, npf_rproc_t *rp, int error)
    115 {
    116 	const uint32_t flags = rp->rp_flags;
    117 
    118 	KASSERT(rp->rp_refcnt > 0);
    119 
    120 	/* Normalise the packet, if required. */
    121 	if ((flags & NPF_RPROC_NORMALIZE) != 0 && !error) {
    122 		(void)npf_normalize(npc, nbuf,
    123 		    rp->rp_rnd_ipid, rp->rp_no_df,
    124 		    rp->rp_minttl, rp->rp_maxmss);
    125 		npf_stats_inc(NPF_STAT_RPROC_NORM);
    126 	}
    127 
    128 	/* Log packet, if required. */
    129 	if ((flags & NPF_RPROC_LOG) != 0) {
    130 		npf_log_packet(npc, nbuf, rp->rp_log_ifid);
    131 		npf_stats_inc(NPF_STAT_RPROC_LOG);
    132 	}
    133 }
    134