/*      $NetBSD: session.c,v 1.36 2025/03/07 15:55:29 christos Exp $    */

/*      $KAME: session.c,v 1.32 2003/09/24 02:01:17 jinmei Exp $        */

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * 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.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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 "config.h"

#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/socket.h>
#if HAVE_SYS_WAIT_H
# include <sys/wait.h>
#endif
#ifndef WEXITSTATUS
# define WEXITSTATUS(s) ((unsigned)(s) >> 8)
#endif
#ifndef WIFEXITED
# define WIFEXITED(s)   (((s) & 255) == 0)
#endif

#include PATH_IPSEC_H

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <signal.h>
#include <sys/stat.h>
#include <paths.h>
#include <err.h>

#include <netinet/in.h>
#include <resolv.h>

#include "libpfkey.h"

#include "var.h"
#include "misc.h"
#include "vmbuf.h"
#include "plog.h"
#include "debug.h"

#include "schedule.h"
#include "session.h"
#include "grabmyaddr.h"
#include "evt.h"
#include "cfparse_proto.h"
#include "isakmp_var.h"
#include "isakmp.h"
#include "isakmp_var.h"
#include "isakmp_xauth.h"
#include "isakmp_cfg.h"
#include "admin_var.h"
#include "admin.h"
#include "privsep.h"
#include "oakley.h"
#include "pfkey.h"
#include "handler.h"
#include "localconf.h"
#include "remoteconf.h"
#include "backupsa.h"
#include "remoteconf.h"
#ifdef ENABLE_NATT
#include "nattraversal.h"
#endif

#include "algorithm.h" /* XXX ??? */

#include "sainfo.h"

struct fd_monitor {
        int (*callback)(void *ctx, int fd);
        void *ctx;
        int prio;
        int fd;
        TAILQ_ENTRY(fd_monitor) chain;
};

#define NUM_PRIORITIES 2

static void close_session(void);
static void init_signal(void);
static int set_signal(int sig, RETSIGTYPE (*func)(int));
static void check_sigreq(void);
static int close_sockets(void);

static fd_set preset_mask, active_mask;
static struct fd_monitor fd_monitors[FD_SETSIZE];
static TAILQ_HEAD(fd_monitor_list, fd_monitor) fd_monitor_tree[NUM_PRIORITIES];
static int nfds = 0;

static volatile sig_atomic_t sigreq[NSIG + 1];

void
monitor_fd(int fd, int (*callback)(void *, int), void *ctx, int priority)
{
        if (fd < 0 || fd >= FD_SETSIZE) {
                plog(LLV_ERROR, LOCATION, NULL, "fd_set overrun");
                exit(1);
        }

        FD_SET(fd, &preset_mask);
        if (fd > nfds)
                nfds = fd;
        if (priority <= 0)
                priority = 0;
        if (priority >= NUM_PRIORITIES)
                priority = NUM_PRIORITIES - 1;

        fd_monitors[fd].callback = callback;
        fd_monitors[fd].ctx = ctx;
        fd_monitors[fd].prio = priority;
        fd_monitors[fd].fd = fd;
        TAILQ_INSERT_TAIL(&fd_monitor_tree[priority],
                          &fd_monitors[fd], chain);
}

void
unmonitor_fd(int fd)
{
        if (fd < 0 || fd >= FD_SETSIZE) {
                plog(LLV_ERROR, LOCATION, NULL, "fd_set overrun");
                exit(1);
        }

        if (fd_monitors[fd].callback == NULL)
                return;

        FD_CLR(fd, &preset_mask);
        FD_CLR(fd, &active_mask);
        fd_monitors[fd].callback = NULL;
        fd_monitors[fd].ctx = NULL;
        TAILQ_REMOVE(&fd_monitor_tree[fd_monitors[fd].prio],
                     &fd_monitors[fd], chain);
}

int
session(void)
{
        struct timeval *timeout;
        int error;
        char pid_file[MAXPATHLEN];
        FILE *fp;
        pid_t racoon_pid = 0;
        int i, count;
        struct fd_monitor *fdm;

        nfds = 0;
        FD_ZERO(&preset_mask);

        for (i = 0; i < NUM_PRIORITIES; i++)
                TAILQ_INIT(&fd_monitor_tree[i]);

        /* initialize schedular */
        sched_init();
        init_signal();

        if (pfkey_init() < 0)
                errx(1, "failed to initialize pfkey socket");

        if (isakmp_init() < 0)
                errx(1, "failed to initialize ISAKMP structures");

#ifdef ENABLE_HYBRID
        if (isakmp_cfg_init(ISAKMP_CFG_INIT_COLD))
                errx(1, "could not initialize ISAKMP mode config structures");
#endif

#ifdef HAVE_LIBLDAP
        if (xauth_ldap_init_conf() != 0)
                errx(1, "could not initialize ldap config");
#endif

#ifdef HAVE_LIBRADIUS
        if (xauth_radius_init_conf(0) != 0)
                errx(1, "could not initialize radius config");
#endif

        myaddr_init_lists();

        /*
         * in order to prefer the parameters by command line,
         * saving some parameters before parsing configuration file.
         */
        save_params();
        if (cfparse() != 0)
                errx(1, "failed to parse configuration file.");
        restore_params();

#ifdef ENABLE_ADMINPORT
        if (admin_init() < 0)
                errx(1, "failed to initialize admin port socket");
#endif


#ifdef ENABLE_HYBRID
        if(isakmp_cfg_config.network4 && isakmp_cfg_config.pool_size == 0)
                if ((error = isakmp_cfg_resize_pool(ISAKMP_CFG_MAX_CNX)) != 0)
                        return error;
#endif

        if (dump_config)
                dumprmconf();

#ifdef HAVE_LIBRADIUS
        if (xauth_radius_init() != 0)
                errx(1, "could not initialize libradius");
#endif

        if (myaddr_init() != 0)
                errx(1, "failed to listen to configured addresses");
        myaddr_sync();

#ifdef ENABLE_NATT
        natt_keepalive_init ();
#endif

        /* write .pid file */
        if (lcconf->pathinfo[LC_PATHTYPE_PIDFILE] == NULL)
                strlcpy(pid_file, _PATH_VARRUN "racoon.pid", MAXPATHLEN);
        else if (lcconf->pathinfo[LC_PATHTYPE_PIDFILE][0] == '/')
                strlcpy(pid_file, lcconf->pathinfo[LC_PATHTYPE_PIDFILE], MAXPATHLEN);
        else {
                strlcat(pid_file, _PATH_VARRUN, MAXPATHLEN);
                strlcat(pid_file, lcconf->pathinfo[LC_PATHTYPE_PIDFILE], MAXPATHLEN);
        }
        fp = fopen(pid_file, "w");
        if (fp) {
                if (fchmod(fileno(fp),
                        S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH) == -1) {
                        syslog(LOG_ERR, "%s", strerror(errno));
                        fclose(fp);
                        exit(1);
                }
        } else {
                plog(LLV_ERROR, LOCATION, NULL,
                        "cannot open %s", pid_file);
        }

        if (privsep_init() != 0)
                exit(1);

        /*
         * The fork()'ed privileged side will close its copy of fp.  We wait
         * until here to get the correct child pid.
         */
        racoon_pid = getpid();
        fprintf(fp, "%ld\n", (long)racoon_pid);
        fclose(fp);

        for (i = 0; i <= NSIG; i++)
                sigreq[i] = 0;

        for (;;) {
                /*
                 * asynchronous requests via signal.
                 * make sure to reset sigreq to 0.
                 */
                check_sigreq();

                /* scheduling */
                timeout = schedular();

                /* schedular can change select() mask, so we reset
                 * the working copy here */
                active_mask = preset_mask;

                error = select(nfds + 1, &active_mask, NULL, NULL, timeout);
                if (error < 0) {
                        switch (errno) {
                        case EINTR:
                                continue;
                        default:
                                plog(LLV_ERROR, LOCATION, NULL,
                                        "failed to select (%s)\n",
                                        strerror(errno));
                                return -1;
                        }
                        /*NOTREACHED*/
                }

                count = 0;
                for (i = 0; i < NUM_PRIORITIES; i++) {
                        TAILQ_FOREACH(fdm, &fd_monitor_tree[i], chain) {
                                if (!FD_ISSET(fdm->fd, &active_mask))
                                        continue;

                                FD_CLR(fdm->fd, &active_mask);
                                if (fdm->callback != NULL) {
                                        fdm->callback(fdm->ctx, fdm->fd);
                                        count++;
                                } else
                                        plog(LLV_ERROR, LOCATION, NULL,
                                        "fd %d set, but no active callback\n", i);
                        }
                        if (count != 0)
                                break;
                }

        }
}

/* clear all status and exit program. */
static void
close_session()
{
        evt_generic(EVT_RACOON_QUIT, NULL);
        pfkey_send_flush(lcconf->sock_pfkey, SADB_SATYPE_UNSPEC);
        flushph2();
        flushph1();
        flushrmconf();
        flushsainfo();
        close_sockets();
        backupsa_clean();

        plog(LLV_INFO, LOCATION, NULL, "racoon process %d shutdown\n", getpid());

        exit(0);
}

static int signals[] = {
        SIGHUP,
        SIGINT,
        SIGTERM,
        SIGUSR1,
        SIGUSR2,
        SIGCHLD,
        0
};

/*
 * asynchronous requests will actually dispatched in the
 * main loop in session().
 */
RETSIGTYPE
signal_handler(int sig)
{
        sigreq[sig] = 1;
}


/* XXX possible mem leaks and no way to go back for now !!!
 */
static void reload_conf(void)
{
        int error;

#ifdef ENABLE_HYBRID
        if ((isakmp_cfg_init(ISAKMP_CFG_INIT_WARM)) != 0) {
                plog(LLV_ERROR, LOCATION, NULL,
                    "ISAKMP mode config structure reset failed, "
                    "not reloading\n");
                return;
        }
#endif

        sainfo_start_reload();

        /* TODO: save / restore / flush old lcconf (?) / rmtree
         */
        rmconf_start_reload();

#ifdef HAVE_LIBRADIUS
        /* free and init radius configuration */
        xauth_radius_init_conf(1);
#endif

        pfkey_reload();

        save_params();
        flushlcconf();
        error = cfparse();
        if (error != 0){
                plog(LLV_ERROR, LOCATION, NULL, "config reload failed\n");
                /* We are probably in an inconsistant state... */
                return;
        }
        restore_params();

#if 0
        if (dump_config)
                dumprmconf ();
#endif

        myaddr_sync();

#ifdef HAVE_LIBRADIUS
        /* re-initialize radius state */
        xauth_radius_init();
#endif

        /* Revalidate ph1 / ph2tree !!!
         * update ctdtree if removing some ph1 !
         */
        revalidate_ph12();
        /* Update ctdtree ?
         */

        sainfo_finish_reload();
        rmconf_finish_reload();
}

static void
check_sigreq()
{
        int sig, s;

        for (sig = 0; sig <= NSIG; sig++) {
                if (sigreq[sig] == 0)
                        continue;
                sigreq[sig] = 0;

                switch(sig) {
                case 0:
                        return;

                case SIGCHLD:
                        /* Reap all pending children */
                        while (waitpid(-1, &s, WNOHANG) > 0)
                                ;
                        break;

#ifdef DEBUG_RECORD_MALLOCATION
                /*
                 * XXX This operation is signal handler unsafe and may lead to
                 * crashes and security breaches: See Henning Brauer talk at
                 * EuroBSDCon 2005. Do not run in production with this option
                 * enabled.
                 */
                case SIGUSR2:
                        DRM_dump();
                        break;
#endif

                case SIGHUP:
                        /* Save old configuration, load new one...  */
                        reload_conf();
                        break;

                case SIGINT:
                case SIGTERM:
                        plog(LLV_INFO, LOCATION, NULL,
                            "caught signal %d\n", sig);
                        close_session();
                        break;

                default:
                        plog(LLV_INFO, LOCATION, NULL,
                            "caught signal %d\n", sig);
                        break;
                }
        }
}

static void
init_signal()
{
        int i;

        /*
         * Ignore SIGPIPE as we check the return value of system calls
         * that write to pipe-like fds.
         */
        signal(SIGPIPE, SIG_IGN);

        for (i = 0; signals[i] != 0; i++)
                if (set_signal(signals[i], signal_handler) < 0) {
                        plog(LLV_ERROR, LOCATION, NULL,
                                "failed to set_signal (%s)\n",
                                strerror(errno));
                        exit(1);
                }
}

static int
set_signal(int sig, RETSIGTYPE (*func)(int))
{
        struct sigaction sa;

        memset((caddr_t)&sa, 0, sizeof(sa));
        sa.sa_handler = func;
        sa.sa_flags = SA_RESTART;

        if (sigemptyset(&sa.sa_mask) < 0)
                return -1;

        if (sigaction(sig, &sa, (struct sigaction *)0) < 0)
                return(-1);

        return 0;
}

static int
close_sockets(void)
{
        myaddr_close();
        pfkey_close(lcconf->sock_pfkey);
#ifdef ENABLE_ADMINPORT
        (void)admin_close();
#endif
        return 0;
}