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daemonlogger.c
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daemonlogger.c
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/* $Id: daemonlogger.c,v 1.21 2008/11/24 19:56:48 roesch Exp $ */
/*************** IMPORTANT DAEMONLOGGER LICENSE TERMS ****************
*
* This Daemonlogger software is the copyrighted work of Sourcefire, Inc.
* (C) 2007 Sourcefire, Inc. All Rights Reserved. This program is free
* software; you may use, redistribute and/or modify this software only under
* the terms and conditions of the GNU General Public License as published by
* the Free Software Foundation; Version 2 with the clarifications and
* exceptions described below. If you wish to embed this Daemonlogger
* technology into proprietary software, we sell alternative licenses (contact
*
* Note that the GPL requires that any work that contains or is derived from
* any GPL licensed work also must be distributed under the GPL. However,
* there exists no definition of what is a "derived work." To avoid
* misunderstandings, we consider an application to constitute a "derivative
* work" for the purpose of this license if it does any of the following:
* - Integrates source code from Daemonlogger.
* - Includes Daemonlogger copyrighted data files.
* - Integrates/includes/aggregates Daemonlogger into a proprietary executable
* installer, such as those produced by InstallShield.
* - Links to a library or executes a program that does any of the above where
* the linked output is not available under the GPL.
*
* The term "Daemonlogger" should be taken to also include any portions or
* derived works of Daemonlogger. This list is not exclusive, but is just
* meant to clarify our interpretation of derived works with some common
* examples. These restrictions only apply when you actually redistribute
* Daemonlogger. For example, nothing stops you from writing and selling a
* proprietary front-end to Daemonlogger. Just distribute it by itself, and
* point people to http://www.snort.org/dl to download Daemonlogger.
*
* We don't consider these to be added restrictions on top of the GPL, but just
* a clarification of how we interpret "derived works" as it applies to our
* GPL-licensed Snort product. This is similar to the way Linus Torvalds has
* announced his interpretation of how "derived works" applies to Linux kernel
* modules. Our interpretation refers only to Daemonlogger - we don't speak
* for any other GPL products.
*
* If you have any questions about the GPL licensing restrictions on using
* Daemonlogger in non-GPL works, we would be happy to help. As mentioned
* above, we also offer alternative license to integrate Daemonlogger into
* proprietary applications and appliances. These contracts can generally
* include a perpetual license as well as providing for priority support and
* updates as well as helping to fund the continued development of Daemonlogger
* technology. Please email [email protected] for further
* information.
*
* If you received these files with a written license agreement or contract
* stating terms other than the terms above, then that alternative license
* agreement takes precedence over these comments.
*
* Source is provided to this software because we believe users have a right to
* know exactly what a program is going to do before they run it. This also
* allows you to audit the software for security holes.
*
* Source code also allows you to port Daemonlogger to new platforms, fix bugs,
* and add new features. You are highly encouraged to send your changes to
* [email protected] for possible incorporation into the main distribution.
* By sending these changes to Sourcefire or one of the Sourcefire-moderated
* mailing lists or forums, you are granting to Sourcefire, Inc. the unlimited,
* perpetual, non-exclusive right to reuse, modify, and/or relicense the code.
* Daemonlogger will always be available Open Source, but this is important
* because the inability to relicense code has caused devastating problems for
* other Free Software projects (such as KDE and NASM). We also occasionally
* relicense the code to third parties as discussed above. If you wish to
* specify special license conditions of your contributions, just say so when
* you send them.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; including without limitation any implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
* Public License for more details at http://www.gnu.org/copyleft/gpl.html,
* or in the COPYING file included with Daemonlogger.
*
*/
/*
** Copyright (C) 2006 Sourcefire Inc. All Rights Reserved.
** Author: Martin Roesch <[email protected]>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <sys/types.h>
#include <errno.h>
#include <getopt.h>
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <signal.h>
#include <time.h>
#include <sys/time.h>
#include <arpa/inet.h>
#include <limits.h>
#include <dirent.h>
#include <syslog.h>
#include <pcap.h>
#include <dnet.h>
#include <grp.h>
#include <pwd.h>
#include <ctype.h>
#include <sys/queue.h>
#include <sys/param.h>
#include <sys/mount.h>
#ifdef LINUX
#include <sys/statvfs.h>
#include <sys/vfs.h>
#endif
#define SUCCESS 0
#define ERROR 1
#define STDBUF 1024
#define KILOBYTE (1UL << 10)
#define MEGABYTE (1UL << 20)
#define GIGABYTE (1UL << 30)
#define TERABYTE (1ULL << 40)
#ifndef VERSION
#define VERSION "1.2.1"
#endif
#define _FILE_OFFSET_BITS 64
#define PRUNE_OLDEST_ABSOLUTE 0
#define PRUNE_OLDEST_IN_RUN 1
/* Fix for broken linux <sys/queue.h> */
#ifndef HAVE_TAILQFOREACH
#define _EVENT_DEFINED_TQENTRY
#define TAILQ_ENTRY(type) \
struct { \
struct type *tqe_next; /* next element */ \
struct type **tqe_prev; /* address of previous next element */ \
}
#define TAILQ_FIRST(head) ((head)->tqh_first)
#define TAILQ_END(head) NULL
#define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next)
#define TAILQ_FOREACH(var, head, field) \
for((var) = TAILQ_FIRST(head); \
(var) != TAILQ_END(head); \
(var) = TAILQ_NEXT(var, field))
#define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \
(elm)->field.tqe_prev = (listelm)->field.tqe_prev; \
(elm)->field.tqe_next = (listelm); \
*(listelm)->field.tqe_prev = (elm); \
(listelm)->field.tqe_prev = &(elm)->field.tqe_next; \
} while (0)
#endif /* TAILQ_FOREACH */
typedef enum {
MINUTES=1,
HOURS,
DAYS
} interval;
static char *interval_names[] = {
"none",
"minutes",
"hours",
"days"
};
typedef enum {
KILOBYTES = 1,
MEGABYTES,
GIGABYTES,
TERABYTES
} size;
static char *size_names[] = {
"none",
"kilobytes",
"megabytes",
"gigabytes",
"terabytes"
};
typedef struct filelist Filelist;
struct file_entry
{
TAILQ_ENTRY(file_entry) next;
char *filename;
};
TAILQ_HEAD(filelist, file_entry);
static Filelist file_list;
/* Runtime config struct */
typedef struct _rt_config
{
int count;
int daemon_mode;
int rollover;
int maxfiles;
int filecount;
int showver;
int datalink;
int shutdown_requested;
int restart_requested;
int ringbuffer;
int use_syslog;
int readback_mode;
int snaplen;
int drop_privs_flag;
int chroot_flag;
int rollover_interval;
int flush_flag;
int maxpct;
int prune_flag;
char *archivepath;
char *interface;
char *retrans_interface;
char *logpath;
char *logfilename;
char *pcap_cmd;
char *readfile;
char *true_pid_name;
char *group_name;
char *user_name;
char *chroot_dir;
char logdir[STDBUF];
char testpath[STDBUF];
u_int64_t rollsize;
time_t lastroll;
time_t nextroll;
u_int64_t rollsize_in_blocks;
pcap_t *pd;
pcap_dumper_t *pdp;
eth_t *eth_retrans;
u_int64_t part_total_blocks;
u_int64_t part_min_free_blocks;
} rt_config_t;
rt_config_t rt_config;
static char *pidfile = "daemonlogger.pid";
static char *pidpath = "/var/run";
static void (*packet_handler)(char *user,
struct pcap_pkthdr *pkthdr,
u_char *pkt);
static int sniff_loop();
static int set_rollover_time();
#ifdef LINUX
#define d_statfs(p, s) statvfs(p, s)
typedef struct statvfs d_statfs_t;
#elif MACOSX
#define d_statfs(p, s) statfs64(p, s)
typedef struct statfs64 d_statfs_t;
#else
#define d_statfs(p, s) statfs(p, s)
typedef struct statfs d_statfs_t;
#endif
static void fatal(const char *format, ...)
{
char buf[STDBUF+1];
va_list ap;
va_start(ap, format);
vsnprintf(buf, STDBUF, format, ap);
if(rt_config.use_syslog)
{
syslog(LOG_CONS | LOG_DAEMON | LOG_ERR, "FATAL ERROR: %s", buf);
}
else
{
fprintf(stderr, "ERROR: %s\n", buf);
fprintf(stderr,"Fatal Error, Quitting..\n");
}
va_end(ap);
exit(1);
}
static void msg(const char *format, ...)
{
char buf[STDBUF+1];
va_list ap;
va_start(ap, format);
vsnprintf(buf, STDBUF, format, ap);
if(rt_config.use_syslog)
{
syslog(LOG_DAEMON | LOG_NOTICE, "%s", buf);
}
else
{
fprintf(stderr, "%s\n", buf);
}
va_end(ap);
}
static int is_valid_path(char *path)
{
struct stat st;
if(path == NULL)
return 0;
if(stat(path, &st) != 0)
return 0;
if(!S_ISDIR(st.st_mode) || access(path, W_OK) == -1)
{
return 0;
}
return 1;
}
static int create_pid_file(char *path, char *filename)
{
char filepath[STDBUF];
char *fp = NULL;
char *fn = NULL;
char pid_buffer[12];
struct flock lock;
int rval;
int fd;
memset(filepath, 0, STDBUF);
if(!filename)
fn = pidfile;
else
fn = filename;
if(!path)
fp = pidpath;
else
fp = path;
if(is_valid_path(fp))
snprintf(filepath, STDBUF-1, "%s/%s", fp, fn);
else
fatal("PID path \"%s\" isn't a writeable directory!", fp);
rt_config.true_pid_name = strdup(filename);
if((fd = open(filepath, O_CREAT | O_WRONLY,
S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)) == -1)
{
return ERROR;
}
/* pid file locking */
lock.l_type = F_WRLCK;
lock.l_start = 0;
lock.l_whence = SEEK_SET;
lock.l_len = 0;
if (fcntl(fd, F_SETLK, &lock) == -1)
{
if (errno == EACCES || errno == EAGAIN)
{
rval = ERROR;
}
else
{
rval = ERROR;
}
close(fd);
return rval;
}
snprintf(pid_buffer, sizeof(pid_buffer), "%d\n", (int) getpid());
ftruncate(fd, 0);
write(fd, pid_buffer, strlen(pid_buffer));
return SUCCESS;
}
int daemonize()
{
pid_t pid;
int fd;
pid = fork();
if (pid > 0)
exit(0); /* parent */
rt_config.use_syslog = 1;
if (pid < 0)
return ERROR;
/* new process group */
setsid();
/* close file handles */
if ((fd = open("/dev/null", O_RDWR)) >= 0)
{
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
if (fd > 2) close(fd);
}
if (pidfile) return create_pid_file(pidpath, pidfile);
return SUCCESS;
}
char *get_filename()
{
time_t currtime;
memset(rt_config.logdir, 0, STDBUF);
currtime = time(NULL);
if(rt_config.logpath != NULL)
{
if(snprintf(rt_config.logdir,
STDBUF,
"%s/%s.%lu",
rt_config.logpath,
rt_config.logfilename,
(long unsigned int) currtime) < 0)
return NULL;
}
else
{
if(snprintf(rt_config.logdir,
STDBUF,
"%s.%lu",
rt_config.logfilename,
(long unsigned int) currtime) < 0)
return NULL;
}
return rt_config.logdir;
}
/*static int go_daemon()
{
return daemonize();
}
*/
static void dl_shutdown(int signal)
{
msg("Quitting!");
if(rt_config.retrans_interface != NULL)
{
eth_close(rt_config.eth_retrans);
}
else
{
if(rt_config.pdp != NULL)
{
pcap_dump_flush(rt_config.pdp);
pcap_dump_close(rt_config.pdp);
}
}
if(rt_config.pd != NULL)
pcap_close(rt_config.pd);
if(rt_config.true_pid_name != NULL)
unlink(rt_config.true_pid_name);
exit(0);
}
static void quitter(int signal)
{
rt_config.shutdown_requested = 1;
alarm(1);
}
static int prune_oldest_file_this_run()
{
struct stat sb;
struct file_entry *fe;
while((fe = TAILQ_FIRST(&file_list)) != NULL)
{
if(fe->filename != NULL)
{
if(stat(fe->filename, &sb) != 0)
{
msg("[ERR] stat failed for \"%s\": %s\n", fe->filename,
strerror(errno));
TAILQ_REMOVE(&file_list, fe, next);
free(fe->filename);
free(fe);
}
else
{
if((sb.st_mode & S_IFMT) == S_IFREG)
{
msg("[!] Ringbuffer: deleting %s", fe->filename);
unlink(fe->filename);
TAILQ_REMOVE(&file_list, fe, next);
free(fe->filename);
free(fe);
break;
}
}
}
else
{
TAILQ_REMOVE(&file_list, fe, next);
free(fe);
}
}
return 0;
}
static int prune_oldest_file_in_dir()
{
DIR *dirp;
struct dirent *dp;
struct stat sb;
time_t oldtime = 0;
char *oldname = NULL;
char fpath[STDBUF+1];
memset(fpath, 0, STDBUF+1);
if(rt_config.logpath != NULL)
{
dirp = opendir(rt_config.logpath);
}
else
dirp = opendir(".");
if(dirp == NULL)
{
msg("opendir failed\n");
return 0;
}
while((dp = readdir(dirp)) != NULL)
{
snprintf(fpath, STDBUF, "%s/%s", rt_config.logpath?rt_config.logpath:".", dp->d_name);
if(stat(fpath, &sb) != 0)
msg("stat failed for \"%s\": %s\n", fpath, strerror(errno));
if((sb.st_mode & S_IFMT) == S_IFREG)
{
if(strstr(dp->d_name, rt_config.logfilename))
{
if(oldtime == 0 || sb.st_mtime < oldtime)
{
oldtime = sb.st_mtime;
if(oldname != NULL)
{
free(oldname);
}
oldname = strdup(fpath);
}
}
}
}
closedir(dirp);
msg("[!] Ringbuffer: deleting %s", oldname);
if(*oldname != 0)
unlink(oldname);
return 0;
}
static int open_log_file()
{
struct file_entry *fe;
char *filepath = get_filename();
if(rt_config.maxfiles == 0 || (rt_config.maxfiles > 0 && rt_config.filecount > 0))
{
if(rt_config.maxfiles > 0)
{
rt_config.filecount--;
if(rt_config.ringbuffer == 0)
msg("%d files to go before quitting", rt_config.filecount+1);
}
}
else
{
if(rt_config.ringbuffer == 0)
{
msg("Max file count reached, exiting");
quitter(1);
return ERROR;
}
else
{
if(rt_config.prune_flag == PRUNE_OLDEST_IN_RUN)
prune_oldest_file_this_run();
else
prune_oldest_file_in_dir();
}
}
if(rt_config.maxpct != 0)
{
d_statfs_t s;
if(d_statfs(rt_config.testpath, &s) != 0)
{
perror("Unable to stat partition!\n");
fatal("EPIC FAIL!");
}
if((s.f_bavail - rt_config.rollsize_in_blocks) < rt_config.part_min_free_blocks)
{
msg("Disk max utilization reached, rolling over and pruning");
if(rt_config.prune_flag == PRUNE_OLDEST_IN_RUN)
prune_oldest_file_this_run();
else
prune_oldest_file_in_dir();
}
}
if(filepath != NULL)
{
if(rt_config.ringbuffer == 1)
{
fe = calloc(sizeof(struct file_entry), sizeof(char));
if((fe->filename = strdup(filepath)) != NULL)
{
if(rt_config.prune_flag == PRUNE_OLDEST_IN_RUN)
TAILQ_INSERT_TAIL(&file_list, fe, next);
#ifdef DEBUG
msg("File_list contents:\n");
TAILQ_FOREACH(fe, &file_list, next)
{
msg(" %s\n", fe->filename);
}
#endif
}
else
{
fatal("Lurene sez ur fucked\n");
}
}
msg("Logging packets to %s", filepath);
if((rt_config.pdp = pcap_dump_open(rt_config.pd, filepath)) == NULL)
{
fatal("Unable to open log file %s\n", pcap_geterr(rt_config.pd));
}
}
else
return ERROR;
return SUCCESS;
}
static int drop_privs(void)
{
struct group *gr;
struct passwd *pw;
char *endptr;
int i;
int do_setuid = 0;
int do_setgid = 0;
unsigned long groupid = 0;
unsigned long userid = 0;
if(rt_config.group_name != NULL)
{
do_setgid = 1;
if(isdigit(rt_config.group_name[0]) == 0)
{
gr = getgrnam(rt_config.group_name);
groupid = gr->gr_gid;
}
else
{
groupid = strtoul(rt_config.group_name, &endptr, 10);
}
}
if(rt_config.user_name != NULL)
{
do_setuid = 1;
do_setgid = 1;
if(isdigit(rt_config.user_name[0]) == 0)
{
pw = getpwnam(rt_config.user_name);
userid = pw->pw_uid;
}
else
{
userid = strtoul(rt_config.user_name, &endptr, 10);
pw = getpwuid(userid);
}
if(rt_config.group_name == NULL)
groupid = pw->pw_gid;
}
if(do_setgid)
{
if((i = setgid(groupid)) < 0)
fatal("Unable to set group ID: %s", strerror(i));
}
endgrent();
endpwent();
if(do_setuid)
{
if(getuid() == 0 && initgroups(rt_config.user_name, groupid) < 0)
fatal("Unable to init group names (%s/%lu)", rt_config.user_name, groupid);
if((i = setuid(userid)) < 0)
fatal("Unable to set user ID: %s\n", strerror(i));
}
return 0;
}
char *get_abs_path(char *dir)
{
char *savedir, *dirp;
if(dir == NULL)
{
return NULL;
}
if((savedir = getcwd(NULL, 0)) == NULL)
{
msg("ERROR: getcwd() failed: %s", strerror(errno));
return NULL;
}
if(chdir(dir) < 0)
{
msg("ERROR: Can't change to directory: %s\n", dir);
free(savedir);
return NULL;
}
dirp = getcwd(NULL, 0);
if(chdir(savedir) < 0)
{
msg("Can't change back to directory: %s\n", dir);
free(savedir);
return NULL;
}
free(savedir);
return (char *) dirp;
}
static int set_chroot(void)
{
char *absdir;
//int abslen = 0;
//char *logdir = NULL;
//logdir = get_abs_path(rt_config.logpath);
/* change to the directory */
if(chdir(rt_config.chroot_dir) != 0)
{
fatal("set_chroot: Can not chdir to \"%s\": %s\n", rt_config.chroot_dir,
strerror(errno));
}
/* always returns an absolute pathname */
absdir = getcwd(NULL, 0);
//abslen = strlen(absdir);
/* make the chroot call */
if(chroot(absdir) < 0)
{
fatal("Can not chroot to \"%s\": absolute: %s: %s\n",
rt_config.chroot_dir, absdir, strerror(errno));
}
if(chdir("/") < 0)
{
fatal("Can not chdir to \"/\" after chroot: %s\n",
strerror(errno));
}
return 0;
}
static int init_retrans()
{
if((rt_config.eth_retrans = eth_open(rt_config.retrans_interface)) == NULL)
fatal("init_retrans() eth_open failed\n");
return 0;
}
static int start_sniffing()
{
bpf_u_int32 localnet, netmask; /* net addr holders */
struct bpf_program fcode; /* Finite state machine holder */
char errorbuf[PCAP_ERRBUF_SIZE]; /* buffer to put error strings in */
bpf_u_int32 defaultnet = 0xFFFFFF00;
if(rt_config.readback_mode == 0)
{
if(rt_config.interface == NULL)
{
rt_config.interface = pcap_lookupdev(errorbuf);
if(rt_config.interface == NULL)
{
fatal("start_sniffing() interface lookup: \n\t%s\n", errorbuf);
}
}
msg("sniffing on interface %s", rt_config.interface);
rt_config.pd = pcap_open_live(rt_config.interface,
rt_config.snaplen?rt_config.snaplen:65535,
1,
500,
errorbuf);
if(rt_config.pd == NULL)
{
fatal("start_sniffing(): interface %s open: %s\n",
rt_config.interface,
errorbuf);
}
}
else
{
msg("Reading network traffic from \"%s\" file.\n", rt_config.readfile);
rt_config.pd = pcap_open_offline(rt_config.readfile, errorbuf);
if(rt_config.pd == NULL)
{
fatal("unable to open file \"%s\" for readback: %s\n",
rt_config.readfile, errorbuf);
}
rt_config.snaplen = pcap_snapshot(rt_config.pd);
msg("snaplen = %d\n", rt_config.snaplen);
}
if(pcap_lookupnet(rt_config.interface, &localnet, &netmask, errorbuf) < 0)
{
msg("start_sniffing() device %s network lookup: "
"\t%s",
rt_config.interface,
errorbuf);
netmask = htonl(defaultnet);
}
if(pcap_compile(rt_config.pd, &fcode, rt_config.pcap_cmd, 1, netmask) < 0)
{
fatal("start_sniffing() FSM compilation failed: \n\t%s\n"
"PCAP command: %s\n", pcap_geterr(rt_config.pd), rt_config.pcap_cmd);
}
/* set the pcap filter */
if(pcap_setfilter(rt_config.pd, &fcode) < 0)
{
fatal("start_sniffing() setfilter: \n\t%s\n",
pcap_geterr(rt_config.pd));
}
/* get data link type */
rt_config.datalink = pcap_datalink(rt_config.pd);
if(rt_config.datalink < 0)
{
fatal("OpenPcap() datalink grab: \n\t%s\n",
pcap_geterr(rt_config.pd));
}
return 0;
}
static int log_rollover()
{
msg("Rolling over logfile...");
if(rt_config.pdp != NULL)
{
pcap_dump_flush(rt_config.pdp);
pcap_dump_close(rt_config.pdp);
rt_config.pdp = NULL;
}
open_log_file();
return SUCCESS;
}
static void dl_restart()
{
rt_config.restart_requested = 0;
if(rt_config.retrans_interface == NULL)
{
pcap_dump_flush(rt_config.pdp);
pcap_dump_close(rt_config.pdp);
}
else
{
eth_close(rt_config.eth_retrans);
}
pcap_close(rt_config.pd);
start_sniffing();
sniff_loop();
}
static void restarter(int signal)
{
msg("Caught SIGHUP, restarting...");
rt_config.restart_requested = 1;
}
static char *load_bpf_file(char *filename)
{
int fd;
int readbytes;
char *filebuf;
char *comment;
struct stat buf;
if((fd = open(filename, O_RDONLY)) < 0)
fatal("Unable to open BPF filter file %s: %s\n",
filename,
pcap_strerror(errno));
if(fstat(fd, &buf) < 0)
fatal("Stat failed on %s: %s\n", filename, pcap_strerror(errno));
filebuf = calloc((unsigned int)buf.st_size + 1, sizeof(unsigned char));
if((readbytes = read(fd, filebuf, (int) buf.st_size)) < 0)
fatal("Read failed on %s: %s\n", filename, pcap_strerror(errno));
if(readbytes != buf.st_size)
fatal("Read bytes != file bytes on %s (%d != %d)\n",
filename, readbytes, (int) buf.st_size);
filebuf[(int)buf.st_size] = '\0';
close(fd);
/* strip comments and <CR>'s */
while((comment = strchr(filebuf, '#')) != NULL)
{
while(*comment != '\r' && *comment != '\n' && comment != '\0')
{
*comment++ = ' ';
}
}
return (filebuf);
}
void packet_dump(char *user, struct pcap_pkthdr *pkthdr, u_char *pkt)
{
time_t now;
if(rt_config.rollover)
{
now = time(NULL);
if(rt_config.rollover_interval == 0)
{
if(rt_config.lastroll + rt_config.rollover < now)
{
msg("Rollover timer has expired!");
log_rollover();
rt_config.lastroll = now;
}
}
else
{
if(now > rt_config.nextroll)
{
msg("Rollover timer has expired!");
log_rollover();
set_rollover_time();
}
}
}
if(rt_config.shutdown_requested == 1)
dl_shutdown(0);
if(rt_config.restart_requested == 1)
dl_restart();