diff toys/pending/syslogd.c @ 960:c0627c163893

syslogd by Madhur Verma.
author Rob Landley <rob@landley.net>
date Thu, 25 Jul 2013 13:28:53 -0500
parents
children 893c86bbe452
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toys/pending/syslogd.c	Thu Jul 25 13:28:53 2013 -0500
@@ -0,0 +1,770 @@
+/* syslogd.c - a system logging utility.
+ *
+ * Copyright 2013 Madhur Verma <mad.flexi@gmail.com>
+ *
+ * No Standard
+
+USE_SYSLOGD(NEWTOY(syslogd,">0l#<1>8=8R:b#<0>99=1s#<0=200m#<0>71582787=20O:p:f:a:nSKLD", TOYFLAG_SBIN|TOYFLAG_STAYROOT))
+
+config SYSLOGD
+  bool "syslogd"
+  default n
+  help
+  Usage: syslogd  [-a socket] [-p socket] [-O logfile] [-f config file] [-m interval]
+                  [-p socket] [-s SIZE] [-b N] [-R HOST] [-l N] [-nSLKD]
+
+  System logging utility
+
+  -a      Extra unix socket for listen
+  -O FILE Default log file <DEFAULT: /var/log/messages>
+  -f FILE Config file <DEFAULT: /etc/syslog.conf>
+  -p      Alternative unix domain socket <DEFAULT : /dev/log>
+  -n      Avoid auto-backgrounding.
+  -S      Smaller output
+  -m MARK interval <DEFAULT: 20 minutes> (RANGE: 0 to 71582787)
+  -R HOST Log to IP or hostname on PORT (default PORT=514/UDP)"
+  -L      Log locally and via network (default is network only if -R)"
+  -s SIZE Max size (KB) before rotation (default:200KB, 0=off)
+  -b N    rotated logs to keep (default:1, max=99, 0=purge)
+  -K      Log to kernel printk buffer (use dmesg to read it)
+  -l N    Log only messages more urgent than prio(default:8 max:8 min:1)
+  -D      Drop duplicates
+*/
+
+#define FOR_syslogd
+#include "toys.h"
+#include "toynet.h"
+
+GLOBALS(
+  char *socket;
+  char *config_file;
+  char *unix_socket;
+  char *logfile;
+  long interval;
+  long rot_size;
+  long rot_count;
+  char *remote_log;
+  long log_prio;
+
+  struct arg_list *lsocks;  // list of listen sockets
+  struct arg_list *lfiles;  // list of write logfiles
+  fd_set rfds;        // fds for reading
+  int sd;            // socket for logging remote messeges.
+)
+
+#define flag_get(f,v,d)  ((toys.optflags & f) ? v : d)
+#define flag_chk(f)    ((toys.optflags & f) ? 1 : 0)
+
+#ifndef SYSLOG_NAMES
+#define  INTERNAL_NOPRI  0x10
+#define  INTERNAL_MARK  LOG_MAKEPRI(LOG_NFACILITIES, 0)
+
+typedef struct _code {
+  char *c_name;
+  int c_val;
+} CODE;
+
+static CODE prioritynames[] =
+{
+  { "alert", LOG_ALERT },
+  { "crit", LOG_CRIT },
+  { "debug", LOG_DEBUG },
+  { "emerg", LOG_EMERG },
+  { "err", LOG_ERR },
+  { "error", LOG_ERR },    /* DEPRECATED */
+  { "info", LOG_INFO },
+  { "none", INTERNAL_NOPRI },    /* INTERNAL */
+  { "notice", LOG_NOTICE },
+  { "panic", LOG_EMERG },    /* DEPRECATED */
+  { "warn", LOG_WARNING },    /* DEPRECATED */
+  { "warning", LOG_WARNING },
+  { NULL, -1 }
+};
+
+static CODE facilitynames[] =
+{
+  { "auth", LOG_AUTH },
+  { "authpriv", LOG_AUTHPRIV },
+  { "cron", LOG_CRON },
+  { "daemon", LOG_DAEMON },
+  { "ftp", LOG_FTP },
+  { "kern", LOG_KERN },
+  { "lpr", LOG_LPR },
+  { "mail", LOG_MAIL },
+  { "mark", INTERNAL_MARK },    /* INTERNAL */
+  { "news", LOG_NEWS },
+  { "security", LOG_AUTH },    /* DEPRECATED */
+  { "syslog", LOG_SYSLOG },
+  { "user", LOG_USER },
+  { "uucp", LOG_UUCP },
+  { "local0", LOG_LOCAL0 },
+  { "local1", LOG_LOCAL1 },
+  { "local2", LOG_LOCAL2 },
+  { "local3", LOG_LOCAL3 },
+  { "local4", LOG_LOCAL4 },
+  { "local5", LOG_LOCAL5 },
+  { "local6", LOG_LOCAL6 },
+  { "local7", LOG_LOCAL7 },
+  { NULL, -1 }
+};
+#endif
+
+
+// Signal handling 
+struct fd_pair { int rd; int wr; };
+static struct fd_pair sigfd;
+
+// UNIX Sockets for listening
+typedef struct unsocks_s {
+  char *path;
+  struct sockaddr_un sdu;
+  int sd;
+} unsocks_t;
+
+// Log file entry to log into.
+typedef struct logfile_s {
+  char *filename;
+  char *config;
+  uint8_t isNetwork;
+  uint32_t facility[8];
+  uint8_t level[LOG_NFACILITIES];
+  int logfd;
+  struct sockaddr_in saddr;
+} logfile_t;
+
+// Adds opened socks to rfds for select()
+static int addrfds(void)
+{
+  unsocks_t *sock;
+  int ret = 0;
+  struct arg_list *node = TT.lsocks;
+  FD_ZERO(&TT.rfds);
+
+  while (node) {
+    sock = (unsocks_t*) node->arg;
+    if (sock->sd > 2) {
+      FD_SET(sock->sd, &TT.rfds);
+      ret = sock->sd;
+    }
+    node = node->next;
+  }
+  FD_SET(sigfd.rd, &TT.rfds);
+  return (sigfd.rd > ret)?sigfd.rd:ret;
+}
+
+/*
+ * initializes unsock_t structure
+ * and opens socket for reading
+ * and adds to global lsock list.
+ */
+static int open_unix_socks(void)
+{
+  struct arg_list *node;
+  unsocks_t *sock;
+  int ret = 0;
+
+  for(node = TT.lsocks; node; node = node->next) {
+    sock = (unsocks_t*) node->arg;
+    sock->sdu.sun_family = AF_UNIX;
+    strcpy(sock->sdu.sun_path, sock->path);
+    sock->sd = socket(AF_UNIX, SOCK_DGRAM, 0);
+    if (sock->sd < 0) {
+      perror_msg("OPEN SOCKS : failed");
+      continue;
+    }
+    unlink(sock->sdu.sun_path);
+    if (bind(sock->sd, (struct sockaddr *) &sock->sdu, sizeof(sock->sdu))) {
+      perror_msg("BIND SOCKS : failed sock : %s", sock->sdu.sun_path);
+      close(sock->sd);
+      continue;
+    }
+    chmod(sock->path, 0777);
+    ret++;
+  }
+  return ret;
+}
+
+/*
+ * creates a socket of family INET and protocol UDP
+ * if successful then returns SOCK othrwise error
+ */
+static int open_udp_socks(char *host, int port, struct sockaddr_in *sadd)
+{
+  struct addrinfo *info, rp;
+
+  memset(&rp, 0, sizeof(rp));
+  rp.ai_family = AF_INET;
+  rp.ai_socktype = SOCK_DGRAM;
+  rp.ai_protocol = IPPROTO_UDP;
+
+  if (getaddrinfo(host, NULL, &rp, &info) || !info) 
+    perror_exit("BAD ADDRESS: can't find : %s ", host);
+  ((struct sockaddr_in*)info->ai_addr)->sin_port = htons(port);
+  memcpy(sadd, info->ai_addr, info->ai_addrlen);
+  freeaddrinfo(info);
+
+  return xsocket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+}
+
+// Returns node having filename
+static struct arg_list *get_file_node(char *filename, struct arg_list *list)
+{
+  while (list) {
+    if (!strcmp(((logfile_t*) list->arg)->filename, filename)) return list;
+    list = list->next;
+  }
+  return list;
+}
+
+/*
+ * recurses the logfile list and resolves config
+ * for evry file and updates facilty and log level bits.
+ */
+static int resolve_config(logfile_t *file)
+{
+  char *tk, *fac, *lvl, *tmp, *nfac;
+  int count = 0;
+  unsigned facval = 0;
+  uint8_t set, levval, neg;
+  CODE *val = NULL;
+
+  tmp = xstrdup(file->config);
+  for (tk = strtok(tmp, "; \0"); tk; tk = strtok(NULL, "; \0")) {
+    fac = tk;
+    tk = strchr(fac, '.');
+    if (!tk) return -1;
+    *tk = '\0';
+    lvl = tk + 1;
+
+    while(1) {
+      count = 0;
+      if (*fac == '*') {
+        facval = 0xFFFFFFFF;
+        fac++;
+      }
+      nfac = strchr(fac, ',');
+      if (nfac) *nfac = '\0';
+      while (*fac && ((CODE*) &facilitynames[count])->c_name) {
+        val = (CODE*) &facilitynames[count];
+        if (!strcmp(fac, val->c_name)) {
+          facval |= (1<<LOG_FAC(val->c_val));
+          break;
+        }
+        count++;
+      }
+      if (((CODE*) &facilitynames[count])->c_val == -1)
+        return -1;
+
+      if (nfac) fac = nfac+1;
+      else break;
+    }
+
+    count = 0;
+    set = 0;
+    levval = 0;
+    neg = 0;
+    if (*lvl == '!') {
+      neg = 1;
+      lvl++;
+    }
+    if (*lvl == '=') {
+      set = 1;
+      lvl++;
+    }
+    if (*lvl == '*') {
+      levval = 0xFF;
+      lvl++;
+    }
+    while (*lvl && ((CODE*) &prioritynames[count])->c_name) {
+      val = (CODE*) &prioritynames[count];
+      if (!strcmp(lvl, val->c_name)) {
+        levval |= set ? LOG_MASK(val->c_val):LOG_UPTO(val->c_val);
+        if (neg) levval = ~levval;
+        break;
+      }
+      count++;
+    }
+    if (((CODE*) &prioritynames[count])->c_val == -1) return -1;
+
+    count = 0;
+    set = levval;
+    while(set) {
+      if (set & 0x1) file->facility[count] |= facval;
+      set >>= 1;
+      count++;
+    }
+    for (count = 0; count < LOG_NFACILITIES; count++) {
+      if (facval & 0x1) file->level[count] |= levval;
+      facval >>= 1;
+    }
+  }
+  free(tmp);
+
+  return 0;
+}
+
+// Parse config file and update the log file list.
+static int parse_config_file(void)
+{
+  logfile_t *file;
+  FILE *fp = NULL;
+  char *confline = NULL, *tk = NULL, *tokens[2] = {NULL, NULL};
+  int len, linelen, tcount, lineno = 0;
+  struct arg_list *node;
+  /*
+   * if -K then open only /dev/kmsg
+   * all other log files are neglected
+   * thus no need to open config either.
+   */
+  if (flag_chk(FLAG_K)) {
+    node = xzalloc(sizeof(struct arg_list));
+    file = xzalloc(sizeof(logfile_t));
+    file->filename = "/dev/kmsg";
+    file->config = "*.*";
+    memset(file->level, 0xFF, sizeof(file->level));
+    memset(file->facility, 0xFFFFFFFF, sizeof(file->facility));
+    node->arg = (char*) file;
+    TT.lfiles = node;
+    return 0;
+  }
+  /*
+   * if -R then add remote host to log list
+   * if -L is not provided all other log
+   * files are neglected thus no need to
+   * open config either so just return.
+   */
+   if (flag_chk(FLAG_R)) {
+     node = xzalloc(sizeof(struct arg_list));
+     file = xzalloc(sizeof(logfile_t));
+     file->filename = xmsprintf("@%s",TT.remote_log);
+     file->isNetwork = 1;
+     file->config = "*.*";
+     memset(file->level, 0xFF, sizeof(file->level));
+     memset(file->facility, 0xFFFFFFFF, sizeof(file->facility));
+     node->arg = (char*) file;
+     TT.lfiles = node;
+     if (!flag_chk(FLAG_L))return 0;
+   }
+  /*
+   * Read config file and add logfiles to the list
+   * with their configuration.
+   */
+  fp = fopen(TT.config_file, "r");
+  if (!fp && flag_chk(FLAG_f))
+    perror_exit("can't open '%s'", TT.config_file);
+
+  for (len = 0, linelen = 0; fp;) {
+    len = getline(&confline, (size_t*) &linelen, fp);
+    if (len <= 0) break;
+    lineno++;
+    for (; *confline == ' '; confline++, len--) ;
+    if ((confline[0] == '#') || (confline[0] == '\n')) continue;
+    for (tcount = 0, tk = strtok(confline, " \t"); tk && (tcount < 2); tk =
+        strtok(NULL, " \t"), tcount++) {
+      if (tcount == 2) {
+        error_msg("error in '%s' at line %d", TT.config_file, lineno);
+        return -1;
+      }
+      tokens[tcount] = xstrdup(tk);
+    }
+    if (tcount <= 1 || tcount > 2) {
+      if (tokens[0]) free(tokens[0]);
+      error_msg("bad line %d: 1 tokens found, 2 needed", lineno);
+      return -1;
+    }
+    tk = (tokens[1] + (strlen(tokens[1]) - 1));
+    if (*tk == '\n') *tk = '\0';
+    if (*tokens[1] == '\0') {
+      error_msg("bad line %d: 1 tokens found, 2 needed", lineno);
+      return -1;
+    }
+    if (*tokens[1] == '*') goto loop_again;
+
+    node = get_file_node(tokens[1], TT.lfiles);
+    if (!node) {
+      node = xzalloc(sizeof(struct arg_list));
+      file = xzalloc(sizeof(logfile_t));
+      file->config = xstrdup(tokens[0]);
+      if (resolve_config(file)==-1) {
+        error_msg("error in '%s' at line %d", TT.config_file, lineno);
+        return -1;
+      }
+      file->filename = xstrdup(tokens[1]);
+      if (*file->filename == '@') file->isNetwork = 1;
+      node->arg = (char*) file;
+      node->next = TT.lfiles;
+      TT.lfiles = node;
+    } else {
+      file = (logfile_t*) node->arg;
+      int rel = strlen(file->config) + strlen(tokens[0]) + 2;
+      file->config = xrealloc(file->config, rel);
+      sprintf(file->config, "%s;%s", file->config, tokens[0]);
+    }
+loop_again:
+    if (tokens[0]) free(tokens[0]);
+    if (tokens[1]) free(tokens[1]);
+    free(confline);
+    confline = NULL;
+  }
+  /*
+   * Can't open config file or support is not enabled
+   * adding default logfile to the head of list.
+   */
+  if (!fp){
+    node = xzalloc(sizeof(struct arg_list));
+    file = xzalloc(sizeof(logfile_t));
+    file->filename = flag_get(FLAG_O, TT.logfile, "/var/log/messages"); //DEFLOGFILE
+    file->isNetwork = 0;
+    file->config = "*.*";
+    memset(file->level, 0xFF, sizeof(file->level));
+    memset(file->facility, 0xFFFFFFFF, sizeof(file->facility));
+    node->arg = (char*) file;
+    node->next = TT.lfiles;
+    TT.lfiles = node;
+  }
+  if (fp) {
+    fclose(fp);
+    fp = NULL;
+  }
+  return 0;
+}
+
+static int getport(char *str, char *filename)
+{
+  char *endptr = NULL;
+  int base = 10;
+  errno = 0;
+  if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X')) {
+    base = 16;
+    str += 2;
+  }
+  long port = strtol(str, &endptr, base);
+  if (errno || *endptr!='\0'|| endptr == str 
+    || port < 0 || port > 65535) error_exit("wrong port no in %s", filename);
+  return (int)port;
+}
+
+// open every log file in list.
+static void open_logfiles(void)
+{
+  logfile_t *tfd;
+  char *p, *tmpfile;
+  int port = -1;
+  struct arg_list *node = TT.lfiles;
+
+  while (node) {
+    tfd = (logfile_t*) node->arg;
+    if (tfd->isNetwork) {
+      tmpfile = xstrdup(tfd->filename +1);
+      if ((p = strchr(tmpfile, ':'))) {
+        *p = '\0';
+        port = getport(p + 1, tfd->filename);
+      }
+      tfd->logfd = open_udp_socks(tmpfile, (port>=0)?port:514, &tfd->saddr);
+      free(tmpfile);
+    } else tfd->logfd = open(tfd->filename, O_CREAT | O_WRONLY | O_APPEND, 0666);
+    if (tfd->logfd < 0) {
+      tfd->filename = "/dev/console";
+      tfd->logfd = open(tfd->filename, O_APPEND);
+    }
+    node = node->next;
+  }
+}
+
+//write to file with rotation
+static int write_rotate( logfile_t *tf, int len)
+{
+  int size, isreg;
+  struct stat statf;
+  isreg = (!fstat(tf->logfd, &statf) && S_ISREG(statf.st_mode));
+  size = statf.st_size;
+
+  if (flag_chk(FLAG_s) || flag_chk(FLAG_b)) {
+    if (TT.rot_size && isreg && (size + len) > (TT.rot_size*1024)) {
+      if (TT.rot_count) { /* always 0..99 */
+        int i = strlen(tf->filename) + 3 + 1;
+        char old_file[i];
+        char new_file[i];
+        i = TT.rot_count - 1;
+        while (1) {
+          sprintf(new_file, "%s.%d", tf->filename, i);
+          if (!i) break;
+          sprintf(old_file, "%s.%d", tf->filename, --i);
+          rename(old_file, new_file);
+        }
+        rename(tf->filename, new_file);
+        unlink(tf->filename);
+        close(tf->logfd);
+        tf->logfd = open(tf->filename, O_CREAT | O_WRONLY | O_APPEND, 0666);
+      }
+      ftruncate(tf->logfd, 0);
+    }
+  }
+  return write(tf->logfd, toybuf, len);
+}
+
+//search the given name and return its value
+static char *dec(int val, CODE *clist)
+{
+  const CODE *c;
+
+  for (c = clist; c->c_name; c++) 
+    if (val == c->c_val) return c->c_name;
+  return itoa(val);
+}
+
+// Compute priority from "facility.level" pair
+static void priority_to_string(int pri, char **facstr, char **lvlstr)
+{
+  int fac,lev;
+
+  fac = LOG_FAC(pri);
+  lev = LOG_PRI(pri);
+  *facstr = dec(fac<<3, facilitynames);
+  *lvlstr = dec(lev, prioritynames);
+}
+
+//Parse messege and write to file.
+static void logmsg(char *msg, int len)
+{
+  time_t now;
+  char *p, *ts, *lvlstr, *facstr;
+  struct utsname uts;
+  int pri = 0;
+  struct arg_list *lnode = TT.lfiles;
+
+  char *omsg = msg;
+  int olen = len, fac, lvl;
+  
+  if (*msg == '<') { // Extract the priority no.
+    pri = (int) strtoul(msg + 1, &p, 10);
+    if (*p == '>') msg = p + 1;
+  }
+  /* Jan 18 00:11:22 msg...
+   * 01234567890123456
+   */
+  if (len < 16 || msg[3] != ' ' || msg[6] != ' ' || msg[9] != ':'
+      || msg[12] != ':' || msg[15] != ' ') {
+    time(&now);
+    ts = ctime(&now) + 4; /* skip day of week */
+  } else {
+    now = 0;
+    ts = msg;
+    msg += 16;
+  }
+  ts[15] = '\0';
+  fac = LOG_FAC(pri);
+  lvl = LOG_PRI(pri);
+
+  if (flag_chk(FLAG_K)) {
+    len = sprintf(toybuf, "<%d> %s\n", pri, msg);
+    goto do_log;
+  }
+  priority_to_string(pri, &facstr, &lvlstr);
+
+  p = "local";
+  if (!uname(&uts)) p = uts.nodename;
+  if (flag_chk(FLAG_S)) len = sprintf(toybuf, "%s %s\n", ts, msg);
+  else len = sprintf(toybuf, "%s %s %s.%s %s\n", ts, p, facstr, lvlstr, msg);
+
+do_log:
+  if (lvl >= TT.log_prio) return;
+
+  while (lnode) {
+    logfile_t *tf = (logfile_t*) lnode->arg;
+    if (tf->logfd > 0) {
+      if ((tf->facility[lvl] & (1 << fac)) && (tf->level[fac] & (1<<lvl))) {
+        int wlen;
+        if (tf->isNetwork)
+          wlen = sendto(tf->logfd, omsg, olen, 0, (struct sockaddr*)&tf->saddr, sizeof(tf->saddr));
+        else wlen = write_rotate(tf, len);
+        if (wlen < 0) perror_msg("write failed file : %s ", (tf->isNetwork)?(tf->filename+1):tf->filename);
+      }
+    }
+    lnode = lnode->next;
+  }
+}
+
+/*
+ * closes all read and write fds
+ * and frees all nodes and lists
+ */
+static void cleanup(void)
+{
+  struct arg_list *fnode;
+  while (TT.lsocks) {
+    fnode = TT.lsocks;
+    if (((unsocks_t*) fnode->arg)->sd >= 0)
+      close(((unsocks_t*) fnode->arg)->sd);
+    free(fnode->arg);
+    TT.lsocks = fnode->next;
+    free(fnode);
+  }
+  unlink("/dev/log");
+
+  while (TT.lfiles) {
+    fnode = TT.lfiles;
+    if (((logfile_t*) fnode->arg)->logfd >= 0)
+      close(((logfile_t*) fnode->arg)->logfd);
+    free(fnode->arg);
+    TT.lfiles = fnode->next;
+    free(fnode);
+  }
+}
+
+static void signal_handler(int sig)
+{
+  unsigned char ch = sig;
+  if (write(sigfd.wr, &ch, 1) != 1) error_msg("can't send signal");
+}
+
+static void setup_signal()
+{
+  if (pipe((int *)&sigfd) < 0) error_exit("pipe failed\n");
+
+  fcntl(sigfd.wr , F_SETFD, FD_CLOEXEC);
+  fcntl(sigfd.rd , F_SETFD, FD_CLOEXEC);
+  int flags = fcntl(sigfd.wr, F_GETFL);
+  fcntl(sigfd.wr, F_SETFL, flags | O_NONBLOCK);
+  signal(SIGHUP, signal_handler);
+  signal(SIGTERM, signal_handler);
+  signal(SIGINT, signal_handler);
+  signal(SIGQUIT, signal_handler);
+}
+
+static void syslog_daemon(void)
+{
+  int fd = open("/dev/null", O_RDWR);
+  if (fd < 0) fd = xcreate("/", O_RDONLY, 0666);
+
+  pid_t pid = fork();
+  if (pid < 0) perror_exit("DAEMON: failed to fork");
+  if (pid) exit(EXIT_SUCCESS);
+
+  setsid();
+  dup2(fd, 0);
+  dup2(fd, 1);
+  dup2(fd, 2);
+  if (fd > 2) close(fd);
+
+  //don't daemonize again if SIGHUP received.
+  toys.optflags |= FLAG_n;
+}
+
+void syslogd_main(void)
+{
+  unsocks_t *tsd;
+  int maxfd, retval, last_len=0;
+  struct timeval tv;
+  struct arg_list *node;
+  char *temp, *buffer = (toybuf +2048), *last_buf = (toybuf + 3072); //these two buffs are of 1K each
+
+  if (flag_chk(FLAG_p) && strlen(TT.unix_socket) > 108)
+    error_exit("Socket path should not be more than 108");
+
+  TT.config_file = flag_get(FLAG_f, TT.config_file, "/etc/syslog.conf"); //DEFCONFFILE
+init_jumpin:
+  TT.lsocks = xzalloc(sizeof(struct arg_list));
+  tsd = xzalloc(sizeof(unsocks_t));
+
+  tsd->path = flag_get(FLAG_p, TT.unix_socket , "/dev/log"); // DEFLOGSOCK
+  TT.lsocks->arg = (char*) tsd;
+
+  if (flag_chk(FLAG_a)) {
+    for (temp = strtok(TT.socket, ":"); temp; temp = strtok(NULL, ":")) {
+      struct arg_list *ltemp = xzalloc(sizeof(struct arg_list));
+      if (strlen(temp) > 107) temp[108] = '\0';
+      tsd = xzalloc(sizeof(unsocks_t));
+      tsd->path = temp;
+      ltemp->arg = (char*) tsd;
+      ltemp->next = TT.lsocks;
+      TT.lsocks = ltemp;
+    }
+  }
+  if (!open_unix_socks()) {
+    error_msg("Can't open single socket for listenning.");
+    goto clean_and_exit;
+  }
+  setup_signal();
+  if (parse_config_file() == -1) goto clean_and_exit;
+  open_logfiles();
+  if (!flag_chk(FLAG_n)) syslog_daemon();
+  {
+    int pid_fd = open("/var/run/syslogd.pid", O_CREAT | O_WRONLY | O_TRUNC, 0666);
+    if (pid_fd > 0) {
+      unsigned pid = getpid();
+      int len = sprintf(toybuf, "%u\n", pid);
+      write(pid_fd, toybuf, len);
+      close(pid_fd);
+    }
+  }
+
+  logmsg("<46>Toybox: syslogd started", 27); //27 : the length of message
+  for (;;) {
+    maxfd = addrfds();
+    tv.tv_usec = 0;
+    tv.tv_sec = TT.interval*60;
+
+    retval = select(maxfd + 1, &TT.rfds, NULL, NULL, (TT.interval)?&tv:NULL);
+    if (retval < 0) { /* Some error. */
+      if (errno == EINTR) continue;
+      perror_msg("Error in select ");
+      continue;
+    }
+    if (!retval) { /* Timed out */
+      logmsg("<46>-- MARK --", 14);
+      continue;
+    }
+    if (FD_ISSET(sigfd.rd, &TT.rfds)) { /* May be a signal */
+      unsigned char sig;
+
+      if (read(sigfd.rd, &sig, 1) != 1) {
+        error_msg("signal read failed.\n");
+        continue;
+      }
+      switch(sig) {
+        case SIGTERM:    /* FALLTHROUGH */
+        case SIGINT:     /* FALLTHROUGH */
+        case SIGQUIT:
+          logmsg("<46>syslogd exiting", 19);
+          if (CFG_TOYBOX_FREE ) cleanup();
+          signal(sig, SIG_DFL);
+          sigset_t ss;
+          sigemptyset(&ss);
+          sigaddset(&ss, sig);
+          sigprocmask(SIG_UNBLOCK, &ss, NULL);
+          raise(sig);
+          _exit(1);  /* Should not reach it */
+          break;
+        case SIGHUP:
+          logmsg("<46>syslogd exiting", 19);
+          cleanup(); //cleanup is done, as we restart syslog.
+          goto init_jumpin;
+        default: break;
+      }
+    }
+    if (retval > 0) { /* Some activity on listen sockets. */
+      node = TT.lsocks;
+      while (node) {
+        int sd = ((unsocks_t*) node->arg)->sd;
+        if (FD_ISSET(sd, &TT.rfds)) {
+          int len = read(sd, buffer, 1023); //buffer is of 1K, hence readingonly 1023 bytes, 1 for NUL
+          if (len > 0) {
+            buffer[len] = '\0';
+            if(flag_chk(FLAG_D) && (len == last_len))
+              if (!memcmp(last_buf, buffer, len)) break;
+
+            memcpy(last_buf, buffer, len);
+            last_len = len;
+            logmsg(buffer, len);
+          }
+          break;
+        }
+        node = node->next;
+      }
+    }
+  }
+clean_and_exit:
+  logmsg("<46>syslogd exiting", 19);
+  if (CFG_TOYBOX_FREE ) cleanup();
+}