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npf_ifaddr.c revision 1.4 
      1 /*-
      2  * Copyright (c) 2014 The NetBSD Foundation, Inc.
      3  * All rights reserved.
      4  *
      5  * This code is derived from software contributed to The NetBSD Foundation
      6  * by Mindaugas Rasiukevicius.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     27  * POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 /*
     31  * NPF network interface handling module.
     32  */
     33 
     34 #ifdef _KERNEL
     35 #include <sys/cdefs.h>
     36 __KERNEL_RCSID(0, "$NetBSD: npf_ifaddr.c,v 1.4 2018/09/29 14:41:36 rmind Exp $");
     37 
     38 #include <sys/param.h>
     39 #include <sys/types.h>
     40 #include <sys/kmem.h>
     41 
     42 #include <net/if.h>
     43 #include <netinet/in.h>
     44 #include <netinet6/in6_var.h>
     45 #endif
     46 
     47 #include "npf_impl.h"
     48 
     49 static npf_table_t *
     50 lookup_ifnet_table(npf_t *npf, ifnet_t *ifp)
     51 {
     52 	const npf_ifops_t *ifops = npf->ifops;
     53 	char tname[NPF_TABLE_MAXNAMELEN];
     54 	npf_tableset_t *ts;
     55 	const char *ifname;
     56 	npf_table_t *t;
     57 	u_int tid;
     58 
     59 	/* Get the interface name and prefix it. */
     60 	ifname = ifops->getname(ifp);
     61 	snprintf(tname, sizeof(tname), ".ifnet-%s", ifname);
     62 
     63 	KERNEL_LOCK(1, NULL);
     64 	npf_config_enter(npf);
     65 	ts = npf_config_tableset(npf);
     66 
     67 	/*
     68 	 * Check whether this interface is of any interest to us.
     69 	 */
     70 	t = npf_tableset_getbyname(ts, tname);
     71 	if (!t) {
     72 		goto out;
     73 	}
     74 	tid = npf_table_getid(t);
     75 
     76 	/* Create a new NPF table for the interface. */
     77 	t = npf_table_create(tname, tid, NPF_TABLE_HASH, NULL, 16);
     78 	if (!t) {
     79 		goto out;
     80 	}
     81 	return t;
     82 out:
     83 	npf_config_exit(npf);
     84 	KERNEL_UNLOCK_ONE(NULL);
     85 	return NULL;
     86 }
     87 
     88 static void
     89 replace_ifnet_table(npf_t *npf, npf_table_t *newt)
     90 {
     91 	npf_tableset_t *ts = npf_config_tableset(npf);
     92 	npf_table_t *oldt;
     93 
     94 	KERNEL_UNLOCK_ONE(NULL);
     95 
     96 	/*
     97 	 * Finally, swap the tables and issue a sync barrier.
     98 	 */
     99 	oldt = npf_tableset_swap(ts, newt);
    100 	npf_config_sync(npf);
    101 	npf_config_exit(npf);
    102 
    103 	/* At this point, it is safe to destroy the old table. */
    104 	npf_table_destroy(oldt);
    105 }
    106 
    107 void
    108 npf_ifaddr_sync(npf_t *npf, ifnet_t *ifp)
    109 {
    110 	npf_table_t *t;
    111 	struct ifaddr *ifa;
    112 
    113 	/*
    114 	 * First, check whether this interface is of any interest to us.
    115 	 *
    116 	 * => Acquires npf-config-lock and kernel-lock on success.
    117 	 */
    118 	t = lookup_ifnet_table(npf, ifp);
    119 	if (!t)
    120 		return;
    121 
    122 	/*
    123 	 * Populate the table with the interface addresses.
    124 	 * Note: currently, this list is protected by the kernel-lock.
    125 	 */
    126 	IFADDR_FOREACH(ifa, ifp) {
    127 		struct sockaddr *sa = ifa->ifa_addr;
    128 		const void *p = NULL;
    129 		int alen = 0;
    130 
    131 		if (sa->sa_family == AF_INET) {
    132 			const struct sockaddr_in *sin4 = satosin(sa);
    133 			alen = sizeof(struct in_addr);
    134 			p = &sin4->sin_addr;
    135 		}
    136 		if (sa->sa_family == AF_INET6) {
    137 			const struct sockaddr_in6 *sin6 = satosin6(sa);
    138 			alen = sizeof(struct in6_addr);
    139 			p = &sin6->sin6_addr;
    140 		}
    141 		if (alen) {
    142 			npf_addr_t addr;
    143 			memcpy(&addr, p, alen);
    144 			npf_table_insert(t, alen, &addr, NPF_NO_NETMASK);
    145 		}
    146 	}
    147 
    148 	/* Publish the new table. */
    149 	replace_ifnet_table(npf, t);
    150 }
    151 
    152 void
    153 npf_ifaddr_flush(npf_t *npf, ifnet_t *ifp)
    154 {
    155 	npf_table_t *t;
    156 
    157 	/*
    158 	 * Flush: just load an empty table.
    159 	 */
    160 	t = lookup_ifnet_table(npf, ifp);
    161 	if (!t) {
    162 		return;
    163 	}
    164 	replace_ifnet_table(npf, t);
    165 }
    166 
    167 void
    168 npf_ifaddr_syncall(npf_t *npf)
    169 {
    170 	ifnet_t *ifp;
    171 
    172 	KERNEL_LOCK(1, NULL);
    173 	IFNET_GLOBAL_LOCK();
    174 	IFNET_WRITER_FOREACH(ifp) {
    175 		npf_ifaddr_sync(npf, ifp);
    176 	}
    177 	IFNET_GLOBAL_UNLOCK();
    178 	KERNEL_UNLOCK_ONE(NULL);
    179 }
    180