/*
* $NetBSD: util.c,v 1.4 2000/08/03 00:04:30 fvdl Exp $
* $FreeBSD$
*/
/*-
* SPDX-License-Identifier: BSD-2-Clause-NetBSD
*
* Copyright (c) 2000 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Frank van der Linden.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/queue.h>
#include <net/if.h>
#include <netinet/in.h>
#include <ifaddrs.h>
#include <sys/poll.h>
#include <rpc/rpc.h>
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include <netconfig.h>
#include <stdio.h>
#include <arpa/inet.h>
#include "rpcbind.h"
static struct sockaddr_in *local_in4;
#ifdef INET6
static struct sockaddr_in6 *local_in6;
#endif
static int bitmaskcmp(struct sockaddr *, struct sockaddr *, struct sockaddr *);
/*
* For all bits set in "mask", compare the corresponding bits in
* "dst" and "src", and see if they match. Returns 0 if the addresses
* match.
*/
static int
bitmaskcmp(struct sockaddr *dst, struct sockaddr *src, struct sockaddr *mask)
{
int i;
u_int8_t *p1, *p2, *netmask;
int bytelen;
if (dst->sa_family != src->sa_family ||
dst->sa_family != mask->sa_family)
return (1);
switch (dst->sa_family) {
case AF_INET:
p1 = (uint8_t*) &SA2SINADDR(dst);
p2 = (uint8_t*) &SA2SINADDR(src);
netmask = (uint8_t*) &SA2SINADDR(mask);
bytelen = sizeof(struct in_addr);
break;
#ifdef INET6
case AF_INET6:
p1 = (uint8_t*) &SA2SIN6ADDR(dst);
p2 = (uint8_t*) &SA2SIN6ADDR(src);
netmask = (uint8_t*) &SA2SIN6ADDR(mask);
bytelen = sizeof(struct in6_addr);
break;
#endif
default:
return (1);
}
for (i = 0; i < bytelen; i++)
if ((p1[i] & netmask[i]) != (p2[i] & netmask[i]))
return (1);
return (0);
}
/*
* Find a server address that can be used by `caller' to contact
* the local service specified by `serv_uaddr'. If `clnt_uaddr' is
* non-NULL, it is used instead of `caller' as a hint suggesting
* the best address (e.g. the `r_addr' field of an rpc, which
* contains the rpcbind server address that the caller used).
*
* Returns the best server address as a malloc'd "universal address"
* string which should be freed by the caller. On error, returns NULL.
*/
char *
addrmerge(struct netbuf *caller, const char *serv_uaddr, const char *clnt_uaddr,
const char *netid)
{
struct ifaddrs *ifap, *ifp = NULL, *bestif;
struct netbuf *serv_nbp = NULL, *hint_nbp = NULL, tbuf;
struct sockaddr *caller_sa, *hint_sa, *ifsa, *ifmasksa, *serv_sa;
struct sockaddr_storage ss;
struct netconfig *nconf;
char *caller_uaddr = NULL;
#ifdef ND_DEBUG
const char *hint_uaddr = NULL;
#endif
char *ret = NULL;
int bestif_goodness;
#ifdef ND_DEBUG
if (debugging)
fprintf(stderr, "addrmerge(caller, %s, %s, %s\n", serv_uaddr,
clnt_uaddr == NULL ? "NULL" : clnt_uaddr, netid);
#endif
caller_sa = caller->buf;
if ((nconf = rpcbind_get_conf(netid)) == NULL)
goto freeit;
if ((caller_uaddr = taddr2uaddr(nconf, caller)) == NULL)
goto freeit;
/*
* Use `clnt_uaddr' as the hint if non-NULL, but ignore it if its
* address family is different from that of the caller.
*/
hint_sa = NULL;
if (clnt_uaddr != NULL) {
#ifdef ND_DEBUG
hint_uaddr = clnt_uaddr;
#endif
if ((hint_nbp = uaddr2taddr(nconf, clnt_uaddr)) == NULL)
goto freeit;
hint_sa = hint_nbp->buf;
}
if (hint_sa == NULL || hint_sa->sa_family != caller_sa->sa_family) {
#ifdef ND_DEBUG
hint_uaddr = caller_uaddr;
#endif
hint_sa = caller->buf;
}
#ifdef ND_DEBUG
if (debugging)
fprintf(stderr, "addrmerge: hint %s\n", hint_uaddr);
#endif
/* Local caller, just return the server address. */
if (strncmp(caller_uaddr, "0.0.0.0.", 8) == 0 ||
strncmp(caller_uaddr, "::.", 3) == 0 || caller_uaddr[0] == '/') {
ret = strdup(serv_uaddr);
goto freeit;
}
if (getifaddrs(&ifp) < 0)
goto freeit;
/*
* Loop through all interface addresses. We are listening to an address
* if any of the following are true:
* a) It's a loopback address
* b) It was specified with the -h command line option
* c) There were no -h command line options.
*
* Among addresses on which we are listening, choose in order of
* preference an address that is:
*
* a) Equal to the hint
* b) A link local address with the same scope ID as the client's
* address, if the client's address is also link local
* c) An address on the same subnet as the client's address
* d) A non-localhost, non-p2p address
* e) Any usable address
*/
bestif = NULL;
bestif_goodness = 0;
for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) {
ifsa = ifap->ifa_addr;
ifmasksa = ifap->ifa_netmask;
/* Skip addresses where we don't listen */
if (ifsa == NULL || ifsa->sa_family != hint_sa->sa_family ||
!(ifap->ifa_flags & IFF_UP))
continue;
if (!(ifap->ifa_flags & IFF_LOOPBACK) && !listen_addr(ifsa))
continue;
if ((hint_sa->sa_family == AF_INET) &&
((((struct sockaddr_in*)hint_sa)->sin_addr.s_addr ==
((struct sockaddr_in*)ifsa)->sin_addr.s_addr))) {
const int goodness = 4;
bestif_goodness = goodness;
bestif = ifap;
goto found;
}
#ifdef INET6
if ((hint_sa->sa_family == AF_INET6) &&
(0 == memcmp(&((struct sockaddr_in6*)hint_sa)->sin6_addr,
&((struct sockaddr_in6*)ifsa)->sin6_addr,
sizeof(struct in6_addr))) &&
(((struct sockaddr_in6*)hint_sa)->sin6_scope_id ==
(((struct sockaddr_in6*)ifsa)->sin6_scope_id))) {
const int goodness = 4;
bestif_goodness = goodness;
bestif = ifap;
goto found;
}
if (hint_sa->sa_family == AF_INET6) {
/*
* For v6 link local addresses, if the caller is on
* a link-local address then use the scope id to see
* which one.
*/
if (IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(ifsa)) &&
IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(caller_sa)) &&
IN6_IS_ADDR_LINKLOCAL(&SA2SIN6ADDR(hint_sa))) {
if (SA2SIN6(ifsa)->sin6_scope_id ==
SA2SIN6(caller_sa)->sin6_scope_id) {
const int goodness = 3;
if (bestif_goodness < goodness) {
bestif = ifap;
bestif_goodness = goodness;
}
}
}
}
#endif /* INET6 */
if (0 == bitmaskcmp(hint_sa, ifsa, ifmasksa)) {
const int goodness = 2;
if (bestif_goodness < goodness) {
bestif = ifap;
bestif_goodness = goodness;
}
}
if (!(ifap->ifa_flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
const int goodness = 1;
if (bestif_goodness < goodness) {
bestif = ifap;
bestif_goodness = goodness;
}
}
if (bestif == NULL)
bestif = ifap;
}
if (bestif == NULL)
goto freeit;
found:
/*
* Construct the new address using the address from
* `bestif', and the port number from `serv_uaddr'.
*/
serv_nbp = uaddr2taddr(nconf, serv_uaddr);
if (serv_nbp == NULL)
goto freeit;
serv_sa = serv_nbp->buf;
memcpy(&ss, bestif->ifa_addr, bestif->ifa_addr->sa_len);
switch (ss.ss_family) {
case AF_INET:
SA2SIN(&ss)->sin_port = SA2SIN(serv_sa)->sin_port;
break;
#ifdef INET6
case AF_INET6:
SA2SIN6(&ss)->sin6_port = SA2SIN6(serv_sa)->sin6_port;
break;
#endif
}
tbuf.len = ss.ss_len;
tbuf.maxlen = sizeof(ss);
tbuf.buf = &ss;
ret = taddr2uaddr(nconf, &tbuf);
freeit:
free(caller_uaddr);
if (hint_nbp != NULL) {
free(hint_nbp->buf);
free(hint_nbp);
}
if (serv_nbp != NULL) {
free(serv_nbp->buf);
free(serv_nbp);
}
if (ifp != NULL)
freeifaddrs(ifp);
#ifdef ND_DEBUG
if (debugging)
fprintf(stderr, "addrmerge: returning %s\n", ret);
#endif
return ret;
}
void
network_init(void)
{
#ifdef INET6
struct ifaddrs *ifap, *ifp;
struct ipv6_mreq mreq6;
unsigned int ifindex;
int s;
#endif
int ecode;
struct addrinfo hints, *res;
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_INET;
if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) {
if (debugging)
fprintf(stderr, "can't get local ip4 address: %s\n",
gai_strerror(ecode));
} else {
local_in4 = (struct sockaddr_in *)malloc(sizeof *local_in4);
if (local_in4 == NULL) {
if (debugging)
fprintf(stderr, "can't alloc local ip4 addr\n");
exit(1);
}
memcpy(local_in4, res->ai_addr, sizeof *local_in4);
freeaddrinfo(res);
}
#ifdef INET6
hints.ai_family = AF_INET6;
if ((ecode = getaddrinfo(NULL, "sunrpc", &hints, &res))) {
if (debugging)
fprintf(stderr, "can't get local ip6 address: %s\n",
gai_strerror(ecode));
} else {
local_in6 = (struct sockaddr_in6 *)malloc(sizeof *local_in6);
if (local_in6 == NULL) {
if (debugging)
fprintf(stderr, "can't alloc local ip6 addr\n");
exit(1);
}
memcpy(local_in6, res->ai_addr, sizeof *local_in6);
freeaddrinfo(res);
}
/*
* Now join the RPC ipv6 multicast group on all interfaces.
*/
if (getifaddrs(&ifp) < 0)
return;
mreq6.ipv6mr_interface = 0;
inet_pton(AF_INET6, RPCB_MULTICAST_ADDR, &mreq6.ipv6mr_multiaddr);
s = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
if (s == -1) {
if (debugging)
fprintf(stderr, "couldn't create ip6 socket");
goto done_inet6;
}
/*
* Loop through all interfaces. For each IPv6 multicast-capable
* interface, join the RPC multicast group on that interface.
*/
for (ifap = ifp; ifap != NULL; ifap = ifap->ifa_next) {
if (ifap->ifa_addr->sa_family != AF_INET6 ||
!(ifap->ifa_flags & IFF_MULTICAST))
continue;
ifindex = if_nametoindex(ifap->ifa_name);
if (ifindex == mreq6.ipv6mr_interface)
/*
* Already did this one.
*/
continue;
mreq6.ipv6mr_interface = ifindex;
if (setsockopt(s, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq6,
sizeof mreq6) < 0)
if (debugging)
perror("setsockopt v6 multicast");
}
done_inet6:
freeifaddrs(ifp);
#endif
/* close(s); */
}
struct sockaddr *
local_sa(int af)
{
switch (af) {
case AF_INET:
return (struct sockaddr *)local_in4;
#ifdef INET6
case AF_INET6:
return (struct sockaddr *)local_in6;
#endif
default:
return NULL;
}
}
