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      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 1.8 2022/02/13 19:20:11 riastradh 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 	const char *ifname;
     55 	npf_config_t *nc;
     56 	npf_table_t *t;
     57 	unsigned tid;
     58 
     59 	/* Get the interface name and prefix it. */
     60 	ifname = ifops->getname(npf, ifp);
     61 	snprintf(tname, sizeof(tname), ".ifnet-%s", ifname);
     62 
     63 	KERNEL_LOCK(1, NULL);
     64 	nc = npf_config_enter(npf);
     65 
     66 	/*
     67 	 * Check whether this interface is of any interest to us.
     68 	 */
     69 	t = npf_tableset_getbyname(nc->tableset, tname);
     70 	if (!t) {
     71 		goto out;
     72 	}
     73 	tid = npf_table_getid(t);
     74 
     75 	/* Create a new NPF table for the interface. */
     76 	t = npf_table_create(tname, tid, NPF_TABLE_IFADDR, NULL, 0);
     77 	if (!t) {
     78 		goto out;
     79 	}
     80 	return t;
     81 out:
     82 	npf_config_exit(npf);
     83 	KERNEL_UNLOCK_ONE(NULL);
     84 	return NULL;
     85 }
     86 
     87 static void
     88 replace_ifnet_table(npf_t *npf, npf_table_t *newt)
     89 {
     90 	npf_tableset_t *ts = atomic_load_relaxed(&npf->config)->tableset;
     91 	npf_table_t *oldt;
     92 
     93 	KASSERT(npf_config_locked_p(npf));
     94 
     95 	KERNEL_UNLOCK_ONE(NULL);
     96 
     97 	/*
     98 	 * Finally, swap the tables and issue a sync barrier.
     99 	 */
    100 	oldt = npf_tableset_swap(ts, newt);
    101 	npf_config_sync(npf);
    102 	npf_config_exit(npf);
    103 
    104 	/* At this point, it is safe to destroy the old table. */
    105 	npf_table_destroy(oldt);
    106 }
    107 
    108 void
    109 npf_ifaddr_sync(npf_t *npf, ifnet_t *ifp)
    110 {
    111 	npf_table_t *t;
    112 	struct ifaddr *ifa;
    113 
    114 	/*
    115 	 * First, check whether this interface is of any interest to us.
    116 	 *
    117 	 * => Acquires npf-config-lock and kernel-lock on success.
    118 	 */
    119 	t = lookup_ifnet_table(npf, ifp);
    120 	if (!t)
    121 		return;
    122 
    123 	/*
    124 	 * Populate the table with the interface addresses.
    125 	 * Note: currently, this list is protected by the kernel-lock.
    126 	 */
    127 	IFADDR_FOREACH(ifa, ifp) {
    128 		struct sockaddr *sa = ifa->ifa_addr;
    129 		const void *p = NULL;
    130 		int alen = 0;
    131 
    132 		if (sa->sa_family == AF_INET) {
    133 			const struct sockaddr_in *sin4 = satosin(sa);
    134 			alen = sizeof(struct in_addr);
    135 			p = &sin4->sin_addr;
    136 		}
    137 		if (sa->sa_family == AF_INET6) {
    138 			const struct sockaddr_in6 *sin6 = satosin6(sa);
    139 			alen = sizeof(struct in6_addr);
    140 			p = &sin6->sin6_addr;
    141 		}
    142 		if (alen) {
    143 			npf_addr_t addr;
    144 			memcpy(&addr, p, alen);
    145 			npf_table_insert(t, alen, &addr, NPF_NO_NETMASK);
    146 		}
    147 	}
    148 
    149 	/* Publish the new table. */
    150 	replace_ifnet_table(npf, t);
    151 }
    152 
    153 void
    154 npf_ifaddr_flush(npf_t *npf, ifnet_t *ifp)
    155 {
    156 	npf_table_t *t;
    157 
    158 	/*
    159 	 * Flush: just load an empty table.
    160 	 */
    161 	t = lookup_ifnet_table(npf, ifp);
    162 	if (!t) {
    163 		return;
    164 	}
    165 	replace_ifnet_table(npf, t);
    166 }
    167 
    168 void
    169 npf_ifaddr_syncall(npf_t *npf)
    170 {
    171 	ifnet_t *ifp;
    172 
    173 	KERNEL_LOCK(1, NULL);
    174 	IFNET_GLOBAL_LOCK();
    175 	IFNET_WRITER_FOREACH(ifp) {
    176 		npf_ifaddr_sync(npf, ifp);
    177 	}
    178 	IFNET_GLOBAL_UNLOCK();
    179 	KERNEL_UNLOCK_ONE(NULL);
    180 }
    181