OpenBSD-4.6/sbin/isakmpd/transport.c
/* $OpenBSD: transport.c,v 1.35 2005/12/28 10:57:35 hshoexer Exp $ */
/* $EOM: transport.c,v 1.43 2000/10/10 12:36:39 provos Exp $ */
/*
* Copyright (c) 1998, 1999 Niklas Hallqvist. All rights reserved.
* Copyright (c) 2001, 2004 Håkan Olsson. All rights reserved.
*
* 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 AUTHOR ``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 AUTHOR 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.
*/
/*
* This code was written under funding by Ericsson Radio Systems.
*/
#include <sys/param.h>
#include <sys/queue.h>
#include <netdb.h>
#include <string.h>
#include "conf.h"
#include "exchange.h"
#include "log.h"
#include "message.h"
#include "sa.h"
#include "timer.h"
#include "transport.h"
#include "virtual.h"
/* If no retransmit limit is given, use this as a default. */
#define RETRANSMIT_DEFAULT 10
LIST_HEAD(transport_method_list, transport_vtbl) transport_method_list;
/* Call the reinit function of the various transports. */
void
transport_reinit(void)
{
struct transport_vtbl *method;
for (method = LIST_FIRST(&transport_method_list); method;
method = LIST_NEXT(method, link))
if (method->reinit)
method->reinit();
}
/* Initialize the transport maintenance module. */
void
transport_init(void)
{
LIST_INIT(&transport_list);
LIST_INIT(&transport_method_list);
}
/* Register another transport T. */
void
transport_setup(struct transport *t, int toplevel)
{
if (toplevel) {
/* Only the toplevel (virtual) transport has sendqueues. */
LOG_DBG((LOG_TRANSPORT, 70,
"transport_setup: virtual transport %p", t));
TAILQ_INIT(&t->sendq);
TAILQ_INIT(&t->prio_sendq);
t->refcnt = 0;
} else {
/* udp and udp_encap trp goes into the transport list. */
LOG_DBG((LOG_TRANSPORT, 70,
"transport_setup: added %p to transport list", t));
LIST_INSERT_HEAD(&transport_list, t, link);
t->refcnt = 1;
}
t->flags = 0;
}
/* Add a referer to transport T. */
void
transport_reference(struct transport *t)
{
t->refcnt++;
LOG_DBG((LOG_TRANSPORT, 95,
"transport_reference: transport %p now has %d references", t,
t->refcnt));
}
/*
* Remove a referer from transport T, removing all of T when no referers left.
*/
void
transport_release(struct transport *t)
{
LOG_DBG((LOG_TRANSPORT, 95,
"transport_release: transport %p had %d references", t,
t->refcnt));
if (--t->refcnt)
return;
LOG_DBG((LOG_TRANSPORT, 70, "transport_release: freeing %p", t));
t->vtbl->remove(t);
}
void
transport_report(void)
{
struct virtual_transport *v;
struct transport *t;
struct message *msg;
for (t = LIST_FIRST(&transport_list); t; t = LIST_NEXT(t, link)) {
LOG_DBG((LOG_REPORT, 0,
"transport_report: transport %p flags %x refcnt %d", t,
t->flags, t->refcnt));
/* XXX Report sth on the virtual transport? */
t->vtbl->report(t);
/*
* This is the reason message_dump_raw lives outside
* message.c.
*/
v = (struct virtual_transport *)t->virtual;
if ((v->encap_is_active && v->encap == t) ||
(!v->encap_is_active && v->main == t)) {
for (msg = TAILQ_FIRST(&t->virtual->prio_sendq); msg;
msg = TAILQ_NEXT(msg, link))
message_dump_raw("udp_report(prio)", msg,
LOG_REPORT);
for (msg = TAILQ_FIRST(&t->virtual->sendq); msg;
msg = TAILQ_NEXT(msg, link))
message_dump_raw("udp_report", msg,
LOG_REPORT);
}
}
}
int
transport_prio_sendqs_empty(void)
{
struct transport *t;
for (t = LIST_FIRST(&transport_list); t; t = LIST_NEXT(t, link))
if (TAILQ_FIRST(&t->virtual->prio_sendq))
return 0;
return 1;
}
/* Register another transport method T. */
void
transport_method_add(struct transport_vtbl *t)
{
LIST_INSERT_HEAD(&transport_method_list, t, link);
}
/*
* Build up a file descriptor set FDS with all transport descriptors we want
* to read from. Return the number of file descriptors select(2) needs to
* check in order to cover the ones we setup in here.
*/
int
transport_fd_set(fd_set * fds)
{
struct transport *t;
int n;
int max = -1;
for (t = LIST_FIRST(&transport_list); t; t = LIST_NEXT(t, link))
if (t->virtual->flags & TRANSPORT_LISTEN) {
n = t->vtbl->fd_set(t, fds, 1);
if (n > max)
max = n;
LOG_DBG((LOG_TRANSPORT, 95, "transport_fd_set: "
"transport %p (virtual %p) fd %d", t,
t->virtual, n));
}
return max + 1;
}
/*
* Build up a file descriptor set FDS with all the descriptors belonging to
* transport where messages are queued for transmittal. Return the number
* of file descriptors select(2) needs to check in order to cover the ones
* we setup in here.
*/
int
transport_pending_wfd_set(fd_set * fds)
{
struct transport *t;
int n;
int max = -1;
for (t = LIST_FIRST(&transport_list); t; t = LIST_NEXT(t, link)) {
if (TAILQ_FIRST(&t->virtual->sendq) ||
TAILQ_FIRST(&t->virtual->prio_sendq)) {
n = t->vtbl->fd_set(t, fds, 1);
LOG_DBG((LOG_TRANSPORT, 95,
"transport_pending_wfd_set: "
"transport %p (virtual %p) fd %d pending", t,
t->virtual, n));
if (n > max)
max = n;
}
}
return max + 1;
}
/*
* For each transport with a file descriptor in FDS, try to get an
* incoming message and start processing it.
*/
void
transport_handle_messages(fd_set *fds)
{
struct transport *t;
for (t = LIST_FIRST(&transport_list); t; t = LIST_NEXT(t, link)) {
if ((t->flags & TRANSPORT_LISTEN) &&
(*t->vtbl->fd_isset)(t, fds)) {
(*t->virtual->vtbl->handle_message)(t);
(*t->vtbl->fd_set)(t, fds, 0);
}
}
}
/*
* Send the first queued message on the transports found whose file
* descriptor is in FDS and has messages queued. Remove the fd bit from
* FDS as soon as one message has been sent on it so other transports
* sharing the socket won't get service without an intervening select
* call. Perhaps a fairness strategy should be implemented between
* such transports. Now early transports in the list will potentially
* be favoured to later ones sharing the file descriptor.
*/
void
transport_send_messages(fd_set * fds)
{
struct transport *t, *next;
struct message *msg;
struct exchange *exchange;
struct sockaddr *dst;
struct timeval expiration;
int expiry, ok_to_drop_message;
char peer[NI_MAXHOST], peersv[NI_MAXSERV];
/*
* Reference all transports first so noone will disappear while in
* use.
*/
for (t = LIST_FIRST(&transport_list); t; t = LIST_NEXT(t, link))
transport_reference(t->virtual);
for (t = LIST_FIRST(&transport_list); t; t = LIST_NEXT(t, link)) {
if ((TAILQ_FIRST(&t->virtual->sendq) ||
TAILQ_FIRST(&t->virtual->prio_sendq)) &&
t->vtbl->fd_isset(t, fds)) {
/* Remove fd bit. */
t->vtbl->fd_set(t, fds, 0);
/* Prefer a message from the prioritized sendq. */
if (TAILQ_FIRST(&t->virtual->prio_sendq)) {
msg = TAILQ_FIRST(&t->virtual->prio_sendq);
TAILQ_REMOVE(&t->virtual->prio_sendq, msg,
link);
} else {
msg = TAILQ_FIRST(&t->virtual->sendq);
TAILQ_REMOVE(&t->virtual->sendq, msg, link);
}
msg->flags &= ~MSG_IN_TRANSIT;
exchange = msg->exchange;
exchange->in_transit = 0;
/*
* We disregard the potential error message here,
* hoping that the retransmit will go better.
* XXX Consider a retry/fatal error discriminator.
*/
t->virtual->vtbl->send_message(msg, 0);
msg->xmits++;
/*
* This piece of code has been proven to be quite
* delicate. Think twice for before altering.
* Here's an outline:
*
* If this message is not the one which finishes an
* exchange, check if we have reached the number of
* retransmit before queuing it up for another.
*
* If it is a finishing message we still may have to
* keep it around for an on-demand retransmit when
* seeing a duplicate of our peer's previous message.
*/
if ((msg->flags & MSG_LAST) == 0) {
if (msg->xmits > conf_get_num("General",
"retransmits", RETRANSMIT_DEFAULT)) {
t->virtual->vtbl->get_dst(t->virtual, &dst);
if (getnameinfo(dst, SA_LEN(dst), peer,
sizeof peer, peersv, sizeof peersv,
NI_NUMERICHOST | NI_NUMERICSERV)) {
strlcpy(peer, "<unknown>", sizeof peer);
strlcpy(peersv, "<?>", sizeof peersv);
}
log_print("transport_send_messages: "
"giving up on exchange %s, no "
"response from peer %s:%s",
exchange->name ? exchange->name :
"<unnamed>", peer, peersv);
exchange->last_sent = 0;
#ifdef notyet
exchange_free(exchange);
exchange = 0;
#endif
} else {
gettimeofday(&expiration, 0);
/*
* XXX Calculate from round trip
* timings and a backoff func.
*/
expiry = msg->xmits * 2 + 5;
expiration.tv_sec += expiry;
LOG_DBG((LOG_TRANSPORT, 30,
"transport_send_messages: "
"message %p scheduled for "
"retransmission %d in %d secs",
msg, msg->xmits, expiry));
if (msg->retrans)
timer_remove_event(msg->retrans);
msg->retrans
= timer_add_event("message_send_expire",
(void (*) (void *)) message_send_expire,
msg, &expiration);
/*
* If we cannot retransmit, we
* cannot...
*/
exchange->last_sent =
msg->retrans ? msg : 0;
}
} else
exchange->last_sent =
exchange->last_received ? msg : 0;
/*
* If this message is not referred to for later
* retransmission it will be ok for us to drop it
* after the post-send function. But as the post-send
* function may remove the exchange, we need to
* remember this fact here.
*/
ok_to_drop_message = exchange->last_sent == 0;
/*
* If this is not a retransmit call post-send
* functions that allows parallel work to be done
* while the network and peer does their share of
* the job. Note that a post-send function may take
* away the exchange we belong to, but only if no
* retransmits are possible.
*/
if (msg->xmits == 1)
message_post_send(msg);
if (ok_to_drop_message)
message_free(msg);
}
}
for (t = LIST_FIRST(&transport_list); t; t = next) {
next = LIST_NEXT(t, link);
transport_release(t->virtual);
}
}
/*
* Textual search after the transport method denoted by NAME, then create
* a transport connected to the peer with address ADDR, given in a transport-
* specific string format.
*/
struct transport *
transport_create(char *name, char *addr)
{
struct transport_vtbl *method;
for (method = LIST_FIRST(&transport_method_list); method;
method = LIST_NEXT(method, link))
if (strcmp(method->name, name) == 0)
return (*method->create) (addr);
return 0;
}