ip_srcid.c revision bd670b35a010421b6e1a5536c34453a827007c81
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* This is used to support the hidden __sin6_src_id in the sockaddr_in6
* structure which is there to ensure that applications (such as UDP apps)
* which get an address from recvfrom and use that address in a sendto
* or connect will by default use the same source address in the "response"
* as the destination address in the "request" they received.
*
* This is built using some new functions (in IP - doing their own locking
* so they can be called from the transports) to map between integer IDs
* and in6_addr_t.
* The use applies to sockaddr_in6 - whether or not mapped addresses are used.
*
* This file contains the functions used by both IP and the transports
* to implement __sin6_src_id.
* The routines do their own locking since they are called from
* the transports (to map between a source id and an address)
* and from IP proper when IP addresses are added and removed.
*
* The routines handle both IPv4 and IPv6 with the IPv4 addresses represented
* as IPv4-mapped addresses.
*/
#include <sys/types.h>
#include <sys/stream.h>
#include <sys/dlpi.h>
#include <sys/stropts.h>
#include <sys/sysmacros.h>
#include <sys/strsubr.h>
#include <sys/strlog.h>
#define _SUN_TPI_VERSION 2
#include <sys/tihdr.h>
#include <sys/xti_inet.h>
#include <sys/ddi.h>
#include <sys/cmn_err.h>
#include <sys/debug.h>
#include <sys/modctl.h>
#include <sys/atomic.h>
#include <sys/zone.h>
#include <sys/systm.h>
#include <sys/param.h>
#include <sys/kmem.h>
#include <sys/callb.h>
#include <sys/socket.h>
#include <sys/vtrace.h>
#include <sys/isa_defs.h>
#include <sys/kmem.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <net/route.h>
#include <sys/sockio.h>
#include <netinet/in.h>
#include <net/if_dl.h>
#include <inet/common.h>
#include <inet/mi.h>
#include <inet/mib2.h>
#include <inet/nd.h>
#include <inet/arp.h>
#include <inet/snmpcom.h>
#include <netinet/igmp_var.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <inet/ip.h>
#include <inet/ip6.h>
#include <inet/tcp.h>
#include <inet/ip_multi.h>
#include <inet/ip_if.h>
#include <inet/ip_ire.h>
#include <inet/ip_rts.h>
#include <inet/optcom.h>
#include <inet/ip_ndp.h>
#include <netinet/igmp.h>
#include <netinet/ip_mroute.h>
#include <inet/ipclassifier.h>
#include <sys/kmem.h>
static uint_t srcid_nextid(ip_stack_t *);
static srcid_map_t **srcid_lookup_addr(const in6_addr_t *addr,
zoneid_t zoneid, ip_stack_t *);
static srcid_map_t **srcid_lookup_id(uint_t id, ip_stack_t *);
/*
* Insert/add a new address to the map.
* Returns zero if ok; otherwise errno (e.g. for memory allocation failure).
*/
int
ip_srcid_insert(const in6_addr_t *addr, zoneid_t zoneid, ip_stack_t *ipst)
{
srcid_map_t **smpp;
#ifdef DEBUG
char abuf[INET6_ADDRSTRLEN];
ip1dbg(("ip_srcid_insert(%s, %d)\n",
inet_ntop(AF_INET6, addr, abuf, sizeof (abuf)), zoneid));
#endif
rw_enter(&ipst->ips_srcid_lock, RW_WRITER);
smpp = srcid_lookup_addr(addr, zoneid, ipst);
if (*smpp != NULL) {
/* Already present - increment refcount */
(*smpp)->sm_refcnt++;
ASSERT((*smpp)->sm_refcnt != 0); /* wraparound */
rw_exit(&ipst->ips_srcid_lock);
return (0);
}
/* Insert new */
*smpp = kmem_alloc(sizeof (srcid_map_t), KM_NOSLEEP);
if (*smpp == NULL) {
rw_exit(&ipst->ips_srcid_lock);
return (ENOMEM);
}
(*smpp)->sm_next = NULL;
(*smpp)->sm_addr = *addr;
(*smpp)->sm_srcid = srcid_nextid(ipst);
(*smpp)->sm_refcnt = 1;
(*smpp)->sm_zoneid = zoneid;
rw_exit(&ipst->ips_srcid_lock);
return (0);
}
/*
* Remove an new address from the map.
* Returns zero if ok; otherwise errno (e.g. for nonexistent address).
*/
int
ip_srcid_remove(const in6_addr_t *addr, zoneid_t zoneid, ip_stack_t *ipst)
{
srcid_map_t **smpp;
srcid_map_t *smp;
#ifdef DEBUG
char abuf[INET6_ADDRSTRLEN];
ip1dbg(("ip_srcid_remove(%s, %d)\n",
inet_ntop(AF_INET6, addr, abuf, sizeof (abuf)), zoneid));
#endif
rw_enter(&ipst->ips_srcid_lock, RW_WRITER);
smpp = srcid_lookup_addr(addr, zoneid, ipst);
smp = *smpp;
if (smp == NULL) {
/* Not preset */
rw_exit(&ipst->ips_srcid_lock);
return (ENOENT);
}
/* Decrement refcount */
ASSERT(smp->sm_refcnt != 0);
smp->sm_refcnt--;
if (smp->sm_refcnt != 0) {
rw_exit(&ipst->ips_srcid_lock);
return (0);
}
/* Remove entry */
*smpp = smp->sm_next;
rw_exit(&ipst->ips_srcid_lock);
smp->sm_next = NULL;
kmem_free(smp, sizeof (srcid_map_t));
return (0);
}
/*
* Map from an address to a source id.
* If the address is unknown return the unknown id (zero).
*/
uint_t
ip_srcid_find_addr(const in6_addr_t *addr, zoneid_t zoneid,
netstack_t *ns)
{
srcid_map_t **smpp;
srcid_map_t *smp;
uint_t id;
ip_stack_t *ipst = ns->netstack_ip;
rw_enter(&ipst->ips_srcid_lock, RW_READER);
smpp = srcid_lookup_addr(addr, zoneid, ipst);
smp = *smpp;
if (smp == NULL) {
char abuf[INET6_ADDRSTRLEN];
/* Not present - could be broadcast or multicast address */
ip1dbg(("ip_srcid_find_addr: unknown %s in zone %d\n",
inet_ntop(AF_INET6, addr, abuf, sizeof (abuf)), zoneid));
id = 0;
} else {
ASSERT(smp->sm_refcnt != 0);
id = smp->sm_srcid;
}
rw_exit(&ipst->ips_srcid_lock);
return (id);
}
/*
* Map from a source id to an address.
* If the id is unknown return the unspecified address.
*/
void
ip_srcid_find_id(uint_t id, in6_addr_t *addr, zoneid_t zoneid,
netstack_t *ns)
{
srcid_map_t **smpp;
srcid_map_t *smp;
ip_stack_t *ipst = ns->netstack_ip;
rw_enter(&ipst->ips_srcid_lock, RW_READER);
smpp = srcid_lookup_id(id, ipst);
smp = *smpp;
if (smp == NULL || (smp->sm_zoneid != zoneid && zoneid != ALL_ZONES)) {
/* Not preset */
ip1dbg(("ip_srcid_find_id: unknown %u or in wrong zone\n", id));
*addr = ipv6_all_zeros;
} else {
ASSERT(smp->sm_refcnt != 0);
*addr = smp->sm_addr;
}
rw_exit(&ipst->ips_srcid_lock);
}
/* Assign the next available ID */
static uint_t
srcid_nextid(ip_stack_t *ipst)
{
uint_t id;
srcid_map_t **smpp;
ASSERT(rw_owner(&ipst->ips_srcid_lock) == curthread);
if (!ipst->ips_srcid_wrapped) {
id = ipst->ips_ip_src_id++;
if (ipst->ips_ip_src_id == 0)
ipst->ips_srcid_wrapped = B_TRUE;
return (id);
}
/* Once it wraps we search for an unused ID. */
for (id = 0; id < 0xffffffff; id++) {
smpp = srcid_lookup_id(id, ipst);
if (*smpp == NULL)
return (id);
}
panic("srcid_nextid: No free identifiers!");
/* NOTREACHED */
}
/*
* Lookup based on address.
* Always returns a non-null pointer.
* If found then *ptr will be the found object.
* Otherwise *ptr will be NULL and can be used to insert a new object.
*/
static srcid_map_t **
srcid_lookup_addr(const in6_addr_t *addr, zoneid_t zoneid, ip_stack_t *ipst)
{
srcid_map_t **smpp;
ASSERT(RW_LOCK_HELD(&ipst->ips_srcid_lock));
smpp = &ipst->ips_srcid_head;
while (*smpp != NULL) {
if (IN6_ARE_ADDR_EQUAL(&(*smpp)->sm_addr, addr) &&
(zoneid == (*smpp)->sm_zoneid || zoneid == ALL_ZONES))
return (smpp);
smpp = &(*smpp)->sm_next;
}
return (smpp);
}
/*
* Lookup based on address.
* Always returns a non-null pointer.
* If found then *ptr will be the found object.
* Otherwise *ptr will be NULL and can be used to insert a new object.
*/
static srcid_map_t **
srcid_lookup_id(uint_t id, ip_stack_t *ipst)
{
srcid_map_t **smpp;
ASSERT(RW_LOCK_HELD(&ipst->ips_srcid_lock));
smpp = &ipst->ips_srcid_head;
while (*smpp != NULL) {
if ((*smpp)->sm_srcid == id)
return (smpp);
smpp = &(*smpp)->sm_next;
}
return (smpp);
}