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mainloop.c
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mainloop.c
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/*
* OpenConnect (SSL + DTLS) VPN client
*
* Copyright © 2008-2011 Intel Corporation.
*
* Author: David Woodhouse <dwmw2@infradead.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* version 2.1, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to:
*
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
#include <errno.h>
#include <poll.h>
#include <limits.h>
#include <sys/select.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <string.h>
#include "openconnect-internal.h"
void queue_packet(struct pkt **q, struct pkt *new)
{
while (*q)
q = &(*q)->next;
new->next = NULL;
*q = new;
}
int queue_new_packet(struct pkt **q, void *buf, int len)
{
struct pkt *new = malloc(sizeof(struct pkt) + len);
if (!new)
return -ENOMEM;
new->len = len;
new->next = NULL;
memcpy(new->data, buf, len);
queue_packet(q, new);
return 0;
}
int killed;
static void handle_sigint(int sig)
{
killed = sig;
}
int vpn_mainloop(struct openconnect_info *vpninfo)
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = handle_sigint;
sigaction(SIGTERM, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
sigaction(SIGHUP, &sa, NULL);
while (!vpninfo->quit_reason) {
int did_work = 0;
int timeout = INT_MAX;
struct timeval tv;
fd_set rfds, wfds, efds;
#ifdef HAVE_DTLS
if (vpninfo->new_dtls_ssl)
dtls_try_handshake(vpninfo);
if (vpninfo->dtls_attempt_period && !vpninfo->dtls_ssl && !vpninfo->new_dtls_ssl &&
vpninfo->new_dtls_started + vpninfo->dtls_attempt_period < time(NULL)) {
vpn_progress(vpninfo, PRG_TRACE, _("Attempt new DTLS connection\n"));
connect_dtls_socket(vpninfo);
}
if (vpninfo->dtls_ssl)
did_work += dtls_mainloop(vpninfo, &timeout);
#endif
if (vpninfo->quit_reason)
break;
did_work += cstp_mainloop(vpninfo, &timeout);
if (vpninfo->quit_reason)
break;
/* Tun must be last because it will set/clear its bit
in the select_rfds according to the queue length */
did_work += tun_mainloop(vpninfo, &timeout);
if (vpninfo->quit_reason)
break;
if (killed) {
if (killed == SIGHUP)
vpninfo->quit_reason = "Client received SIGHUP";
else if (killed == SIGINT)
vpninfo->quit_reason = "Client received SIGINT";
else
vpninfo->quit_reason = "Client killed";
break;
}
if (did_work)
continue;
vpn_progress(vpninfo, PRG_TRACE,
_("No work to do; sleeping for %d ms...\n"), timeout);
memcpy(&rfds, &vpninfo->select_rfds, sizeof(rfds));
memcpy(&wfds, &vpninfo->select_wfds, sizeof(wfds));
memcpy(&efds, &vpninfo->select_efds, sizeof(efds));
tv.tv_sec = timeout / 1000;
tv.tv_usec = (timeout % 1000) * 1000;
select(vpninfo->select_nfds, &rfds, &wfds, &efds, &tv);
}
cstp_bye(vpninfo, vpninfo->quit_reason);
shutdown_tun(vpninfo);
return 0;
}
/* Called when the socket is unwritable, to get the deadline for DPD.
Returns 1 if DPD deadline has already arrived. */
int ka_stalled_action(struct keepalive_info *ka, int *timeout)
{
time_t due, now = time(NULL);
if (ka->rekey) {
due = ka->last_rekey + ka->rekey;
if (now >= due)
return KA_REKEY;
if (*timeout > (due - now) * 1000)
*timeout = (due - now) * 1000;
}
if (!ka->dpd)
return KA_NONE;
due = ka->last_rx + (2 * ka->dpd);
if (now > due)
return KA_DPD_DEAD;
if (*timeout > (due - now) * 1000)
*timeout = (due - now) * 1000;
return KA_NONE;
}
int keepalive_action(struct keepalive_info *ka, int *timeout)
{
time_t now = time(NULL);
if (ka->rekey) {
time_t due = ka->last_rekey + ka->rekey;
if (now >= due)
return KA_REKEY;
if (*timeout > (due - now) * 1000)
*timeout = (due - now) * 1000;
}
/* DPD is bidirectional -- PKT 3 out, PKT 4 back */
if (ka->dpd) {
time_t due = ka->last_rx + ka->dpd;
time_t overdue = ka->last_rx + (2 * ka->dpd);
/* Peer didn't respond */
if (now > overdue)
return KA_DPD_DEAD;
/* If we already have DPD outstanding, don't flood. Repeat by
all means, but only after half the DPD period. */
if (ka->last_dpd > ka->last_rx)
due = ka->last_dpd + ka->dpd / 2;
/* We haven't seen a packet from this host for $DPD seconds.
Prod it to see if it's still alive */
if (now >= due) {
ka->last_dpd = now;
return KA_DPD;
}
if (*timeout > (due - now) * 1000)
*timeout = (due - now) * 1000;
}
/* Keepalive is just client -> server */
if (ka->keepalive) {
time_t due = ka->last_tx + ka->keepalive;
/* If we haven't sent anything for $KEEPALIVE seconds, send a
dummy packet (which the server will discard) */
if (now >= due)
return KA_KEEPALIVE;
if (*timeout > (due - now) * 1000)
*timeout = (due - now) * 1000;
}
return KA_NONE;
}