This commit is contained in:
Martin Willi
@@ -0,0 +1,537 @@
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/* timer event handling
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* Copyright (C) 1997 Angelos D. Keromytis.
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* Copyright (C) 1998-2001 D. Hugh Redelmeier.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*
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* RCSID $Id: timer.c,v 1.5 2004/09/17 21:36:57 as Exp $
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <time.h>
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#include <unistd.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <sys/queue.h>
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#include <freeswan.h>
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#include "constants.h"
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#include "defs.h"
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#include "connections.h"
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#include "state.h"
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#include "demux.h"
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#include "ipsec_doi.h" /* needs demux.h and state.h */
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#include "kernel.h"
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#include "server.h"
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#include "log.h"
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#include "rnd.h"
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#include "timer.h"
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#include "whack.h"
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#ifdef NAT_TRAVERSAL
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#include "nat_traversal.h"
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#endif
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/* monotonic version of time(3) */
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time_t
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now(void)
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{
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static time_t delta = 0
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, last_time = 0;
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time_t n = time((time_t)NULL);
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passert(n != (time_t)-1);
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if (last_time > n)
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{
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plog("time moved backwards %ld seconds", (long)(last_time - n));
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delta += last_time - n;
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}
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last_time = n;
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return n + delta;
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}
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/* This file has the event handling routines. Events are
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* kept as a linked list of event structures. These structures
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* have information like event type, expiration time and a pointer
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* to event specific data (for example, to a state structure).
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*/
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static struct event *evlist = (struct event *) NULL;
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/*
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* This routine places an event in the event list.
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*/
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void
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event_schedule(enum event_type type, time_t tm, struct state *st)
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{
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struct event *ev = alloc_thing(struct event, "struct event in event_schedule()");
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ev->ev_type = type;
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ev->ev_time = tm + now();
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ev->ev_state = st;
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/* If the event is associated with a state, put a backpointer to the
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* event in the state object, so we can find and delete the event
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* if we need to (for example, if we receive a reply).
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*/
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if (st != NULL)
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{
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if (type == EVENT_DPD || type == EVENT_DPD_TIMEOUT)
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{
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passert(st->st_dpd_event == NULL);
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st->st_dpd_event = ev;
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}
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else
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{
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passert(st->st_event == NULL);
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st->st_event = ev;
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}
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}
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DBG(DBG_CONTROL,
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if (st == NULL)
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DBG_log("inserting event %s, timeout in %lu seconds"
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, enum_show(&timer_event_names, type), (unsigned long)tm);
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else
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DBG_log("inserting event %s, timeout in %lu seconds for #%lu"
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, enum_show(&timer_event_names, type), (unsigned long)tm
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, ev->ev_state->st_serialno));
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if (evlist == (struct event *) NULL
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|| evlist->ev_time >= ev->ev_time)
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{
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ev->ev_next = evlist;
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evlist = ev;
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}
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else
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{
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struct event *evt;
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for (evt = evlist; evt->ev_next != NULL; evt = evt->ev_next)
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if (evt->ev_next->ev_time >= ev->ev_time)
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break;
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#ifdef NEVER /* this seems to be overkill */
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DBG(DBG_CONTROL,
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if (evt->ev_state == NULL)
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DBG_log("event added after event %s"
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, enum_show(&timer_event_names, evt->ev_type));
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else
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DBG_log("event added after event %s for #%lu"
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, enum_show(&timer_event_names, evt->ev_type)
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, evt->ev_state->st_serialno));
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#endif /* NEVER */
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ev->ev_next = evt->ev_next;
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evt->ev_next = ev;
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}
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}
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/*
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* Handle the first event on the list.
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*/
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void
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handle_timer_event(void)
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{
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time_t tm;
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struct event *ev = evlist;
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int type;
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struct state *st;
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struct connection *c = NULL;
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ip_address peer;
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if (ev == (struct event *) NULL) /* Just paranoid */
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{
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DBG(DBG_CONTROL, DBG_log("empty event list, yet we're called"));
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return;
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}
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type = ev->ev_type;
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st = ev->ev_state;
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tm = now();
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if (tm < ev->ev_time)
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{
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DBG(DBG_CONTROL, DBG_log("called while no event expired (%lu/%lu, %s)"
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, (unsigned long)tm, (unsigned long)ev->ev_time
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, enum_show(&timer_event_names, type)));
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/* This will happen if the most close-to-expire event was
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* a retransmission or cleanup, and we received a packet
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* at the same time as the event expired. Due to the processing
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* order in call_server(), the packet processing will happen first,
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* and the event will be removed.
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*/
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return;
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}
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evlist = evlist->ev_next; /* Ok, we'll handle this event */
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DBG(DBG_CONTROL,
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if (evlist != (struct event *) NULL)
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DBG_log("event after this is %s in %ld seconds"
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, enum_show(&timer_event_names, evlist->ev_type)
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, (long) (evlist->ev_time - tm)));
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/* for state-associated events, pick up the state pointer
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* and remove the backpointer from the state object.
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* We'll eventually either schedule a new event, or delete the state.
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*/
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passert(GLOBALS_ARE_RESET());
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if (st != NULL)
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{
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c = st->st_connection;
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if (type == EVENT_DPD || type == EVENT_DPD_TIMEOUT)
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{
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passert(st->st_dpd_event == ev);
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st->st_dpd_event = NULL;
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}
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else
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{
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passert(st->st_event == ev);
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st->st_event = NULL;
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}
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peer = c->spd.that.host_addr;
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set_cur_state(st);
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}
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switch (type)
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{
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case EVENT_REINIT_SECRET:
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passert(st == NULL);
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DBG(DBG_CONTROL, DBG_log("event EVENT_REINIT_SECRET handled"));
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init_secret();
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break;
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#ifdef KLIPS
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case EVENT_SHUNT_SCAN:
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passert(st == NULL);
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scan_proc_shunts();
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break;
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#endif
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case EVENT_LOG_DAILY:
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daily_log_event();
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break;
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case EVENT_RETRANSMIT:
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/* Time to retransmit, or give up.
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*
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* Generally, we'll only try to send the message
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* MAXIMUM_RETRANSMISSIONS times. Each time we double
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* our patience.
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*
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* As a special case, if this is the first initiating message
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* of a Main Mode exchange, and we have been directed to try
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* forever, we'll extend the number of retransmissions to
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* MAXIMUM_RETRANSMISSIONS_INITIAL times, with all these
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* extended attempts having the same patience. The intention
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* is to reduce the bother when nobody is home.
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*/
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{
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time_t delay = 0;
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DBG(DBG_CONTROL, DBG_log(
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"handling event EVENT_RETRANSMIT for %s \"%s\" #%lu"
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, ip_str(&peer), c->name, st->st_serialno));
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if (st->st_retransmit < MAXIMUM_RETRANSMISSIONS)
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delay = EVENT_RETRANSMIT_DELAY_0 << (st->st_retransmit + 1);
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else if (st->st_state == STATE_MAIN_I1
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&& c->sa_keying_tries == 0
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&& st->st_retransmit < MAXIMUM_RETRANSMISSIONS_INITIAL)
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delay = EVENT_RETRANSMIT_DELAY_0 << MAXIMUM_RETRANSMISSIONS;
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if (delay != 0)
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{
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st->st_retransmit++;
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whack_log(RC_RETRANSMISSION
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, "%s: retransmission; will wait %lus for response"
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, enum_name(&state_names, st->st_state)
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, (unsigned long)delay);
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send_packet(st, "EVENT_RETRANSMIT");
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event_schedule(EVENT_RETRANSMIT, delay, st);
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}
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else
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{
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/* check if we've tried rekeying enough times.
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* st->st_try == 0 means that this should be the only try.
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* c->sa_keying_tries == 0 means that there is no limit.
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*/
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unsigned long try = st->st_try;
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unsigned long try_limit = c->sa_keying_tries;
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const char *details = "";
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switch (st->st_state)
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{
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case STATE_MAIN_I3:
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details = ". Possible authentication failure:"
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" no acceptable response to our"
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" first encrypted message";
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break;
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case STATE_MAIN_I1:
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details = ". No response (or no acceptable response) to our"
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" first IKE message";
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break;
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case STATE_QUICK_I1:
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if (c->newest_ipsec_sa == SOS_NOBODY)
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details = ". No acceptable response to our"
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" first Quick Mode message:"
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" perhaps peer likes no proposal";
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break;
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default:
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break;
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}
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loglog(RC_NORETRANSMISSION
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, "max number of retransmissions (%d) reached %s%s"
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, st->st_retransmit
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, enum_show(&state_names, st->st_state), details);
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if (try != 0 && try != try_limit)
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{
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/* A lot like EVENT_SA_REPLACE, but over again.
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* Since we know that st cannot be in use,
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* we can delete it right away.
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*/
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char story[80]; /* arbitrary limit */
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try++;
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snprintf(story, sizeof(story), try_limit == 0
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? "starting keying attempt %ld of an unlimited number"
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: "starting keying attempt %ld of at most %ld"
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, try, try_limit);
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if (st->st_whack_sock != NULL_FD)
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{
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/* Release whack because the observer will get bored. */
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loglog(RC_COMMENT, "%s, but releasing whack"
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, story);
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release_pending_whacks(st, story);
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}
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else
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{
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/* no whack: just log to syslog */
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plog("%s", story);
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}
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ipsecdoi_replace(st, try);
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}
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delete_state(st);
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}
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}
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break;
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case EVENT_SA_REPLACE:
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case EVENT_SA_REPLACE_IF_USED:
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{
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so_serial_t newest = IS_PHASE1(st->st_state)
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? c->newest_isakmp_sa : c->newest_ipsec_sa;
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if (newest != st->st_serialno
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&& newest != SOS_NOBODY)
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{
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/* not very interesting: no need to replace */
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DBG(DBG_LIFECYCLE
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, plog("not replacing stale %s SA: #%lu will do"
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, IS_PHASE1(st->st_state)? "ISAKMP" : "IPsec"
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, newest));
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}
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else if (type == EVENT_SA_REPLACE_IF_USED
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&& st->st_outbound_time <= tm - c->sa_rekey_margin)
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{
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/* we observed no recent use: no need to replace
|
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*
|
||||
* The sampling effects mean that st_outbound_time
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* could be up to SHUNT_SCAN_INTERVAL more recent
|
||||
* than actual traffic because the sampler looks at change
|
||||
* over that interval.
|
||||
* st_outbound_time could also not yet reflect traffic
|
||||
* in the last SHUNT_SCAN_INTERVAL.
|
||||
* We expect that SHUNT_SCAN_INTERVAL is smaller than
|
||||
* c->sa_rekey_margin so that the effects of this will
|
||||
* be unimportant.
|
||||
* This is just an optimization: correctness is not
|
||||
* at stake.
|
||||
*
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||||
* Note: we are abusing the DBG mechanism to control
|
||||
* normal log output.
|
||||
*/
|
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DBG(DBG_LIFECYCLE
|
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, plog("not replacing stale %s SA: inactive for %lus"
|
||||
, IS_PHASE1(st->st_state)? "ISAKMP" : "IPsec"
|
||||
, (unsigned long)(tm - st->st_outbound_time)));
|
||||
}
|
||||
else
|
||||
{
|
||||
DBG(DBG_LIFECYCLE
|
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, plog("replacing stale %s SA"
|
||||
, IS_PHASE1(st->st_state)? "ISAKMP" : "IPsec"));
|
||||
ipsecdoi_replace(st, 1);
|
||||
}
|
||||
delete_dpd_event(st);
|
||||
event_schedule(EVENT_SA_EXPIRE, st->st_margin, st);
|
||||
}
|
||||
break;
|
||||
|
||||
case EVENT_SA_EXPIRE:
|
||||
{
|
||||
const char *satype;
|
||||
so_serial_t latest;
|
||||
|
||||
if (IS_PHASE1(st->st_state))
|
||||
{
|
||||
satype = "ISAKMP";
|
||||
latest = c->newest_isakmp_sa;
|
||||
}
|
||||
else
|
||||
{
|
||||
satype = "IPsec";
|
||||
latest = c->newest_ipsec_sa;
|
||||
}
|
||||
|
||||
if (st->st_serialno != latest)
|
||||
{
|
||||
/* not very interesting: already superseded */
|
||||
DBG(DBG_LIFECYCLE
|
||||
, plog("%s SA expired (superseded by #%lu)"
|
||||
, satype, latest));
|
||||
}
|
||||
else
|
||||
{
|
||||
plog("%s SA expired (%s)", satype
|
||||
, (c->policy & POLICY_DONT_REKEY)
|
||||
? "--dontrekey"
|
||||
: "LATEST!"
|
||||
);
|
||||
}
|
||||
}
|
||||
/* FALLTHROUGH */
|
||||
case EVENT_SO_DISCARD:
|
||||
/* Delete this state object. It must be in the hash table. */
|
||||
delete_state(st);
|
||||
break;
|
||||
|
||||
case EVENT_DPD:
|
||||
dpd_outI(st);
|
||||
break;
|
||||
case EVENT_DPD_TIMEOUT:
|
||||
dpd_timeout(st);
|
||||
break;
|
||||
#ifdef NAT_TRAVERSAL
|
||||
case EVENT_NAT_T_KEEPALIVE:
|
||||
nat_traversal_ka_event();
|
||||
break;
|
||||
#endif
|
||||
default:
|
||||
loglog(RC_LOG_SERIOUS, "INTERNAL ERROR: ignoring unknown expiring event %s"
|
||||
, enum_show(&timer_event_names, type));
|
||||
}
|
||||
|
||||
pfree(ev);
|
||||
reset_cur_state();
|
||||
}
|
||||
|
||||
/*
|
||||
* Return the time until the next event in the queue
|
||||
* expires (never negative), or -1 if no jobs in queue.
|
||||
*/
|
||||
long
|
||||
next_event(void)
|
||||
{
|
||||
time_t tm;
|
||||
|
||||
if (evlist == (struct event *) NULL)
|
||||
return -1;
|
||||
|
||||
tm = now();
|
||||
|
||||
DBG(DBG_CONTROL,
|
||||
if (evlist->ev_state == NULL)
|
||||
DBG_log("next event %s in %ld seconds"
|
||||
, enum_show(&timer_event_names, evlist->ev_type)
|
||||
, (long)evlist->ev_time - (long)tm);
|
||||
else
|
||||
DBG_log("next event %s in %ld seconds for #%lu"
|
||||
, enum_show(&timer_event_names, evlist->ev_type)
|
||||
, (long)evlist->ev_time - (long)tm
|
||||
, evlist->ev_state->st_serialno));
|
||||
|
||||
if (evlist->ev_time - tm <= 0)
|
||||
return 0;
|
||||
else
|
||||
return evlist->ev_time - tm;
|
||||
}
|
||||
|
||||
/*
|
||||
* Delete an event.
|
||||
*/
|
||||
void
|
||||
delete_event(struct state *st)
|
||||
{
|
||||
if (st->st_event != (struct event *) NULL)
|
||||
{
|
||||
struct event **ev;
|
||||
|
||||
for (ev = &evlist; ; ev = &(*ev)->ev_next)
|
||||
{
|
||||
if (*ev == NULL)
|
||||
{
|
||||
DBG(DBG_CONTROL, DBG_log("event %s to be deleted not found",
|
||||
enum_show(&timer_event_names, st->st_event->ev_type)));
|
||||
break;
|
||||
}
|
||||
if ((*ev) == st->st_event)
|
||||
{
|
||||
*ev = (*ev)->ev_next;
|
||||
|
||||
if (st->st_event->ev_type == EVENT_RETRANSMIT)
|
||||
st->st_retransmit = 0;
|
||||
pfree(st->st_event);
|
||||
st->st_event = (struct event *) NULL;
|
||||
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Delete a DPD event.
|
||||
*/
|
||||
void
|
||||
delete_dpd_event(struct state *st)
|
||||
{
|
||||
if (st->st_dpd_event != (struct event *) NULL)
|
||||
{
|
||||
struct event **ev;
|
||||
|
||||
for (ev = &evlist; ; ev = &(*ev)->ev_next)
|
||||
{
|
||||
if (*ev == NULL)
|
||||
{
|
||||
DBG(DBG_CONTROL, DBG_log("event %s to be deleted not found",
|
||||
enum_show(&timer_event_names, st->st_dpd_event->ev_type)));
|
||||
break;
|
||||
}
|
||||
if ((*ev) == st->st_dpd_event)
|
||||
{
|
||||
*ev = (*ev)->ev_next;
|
||||
pfree(st->st_dpd_event);
|
||||
st->st_dpd_event = (struct event *) NULL;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
Reference in New Issue
Block a user