src/vlib/unix/main.c - fdio/vpp - Gitiles

 /*
  * Copyright (c) 2015 Cisco and/or its affiliates.
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 /*
  * main.c: Unix main routine
  *
  * Copyright (c) 2008 Eliot Dresselhaus
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
  * without limitation the rights to use, copy, modify, merge, publish,
  * distribute, sublicense, and/or sell copies of the Software, and to
  * permit persons to whom the Software is furnished to do so, subject to
  * the following conditions:
  *
  * The above copyright notice and this permission notice shall be
  * included in all copies or substantial portions of the Software.
  *
  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 #include <vlib/vlib.h>
 #include <vlib/unix/unix.h>
 #include <vlib/unix/plugin.h>

 #include <signal.h>
 #include <sys/ucontext.h>
 #include <syslog.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <unistd.h>

 /** Default CLI pager limit is not configured in startup.conf */
 #define UNIX_CLI_DEFAULT_PAGER_LIMIT 100000

 /** Default CLI history depth if not configured in startup.conf */
 #define UNIX_CLI_DEFAULT_HISTORY 50

 char *vlib_default_runtime_dir __attribute__ ((weak));
 char *vlib_default_runtime_dir = "vlib";

 unix_main_t unix_main;
 clib_file_main_t file_main;
 vlib_physmem_main_t physmem_main;

 static clib_error_t *
 unix_main_init (vlib_main_t * vm)
 {
   unix_main_t *um = &unix_main;
   um->vlib_main = vm;
   return vlib_call_init_function (vm, unix_input_init);
 }

 VLIB_INIT_FUNCTION (unix_main_init);

 static int
 unsetup_signal_handlers (int sig)
 {
   struct sigaction sa;

   sa.sa_handler = SIG_DFL;
   sa.sa_flags = 0;
   sigemptyset (&sa.sa_mask);
   return sigaction (sig, &sa, 0);
 }


 /* allocate this buffer from mheap when setting up the signal handler.
     dangerous to vec_resize it when crashing, mheap itself might have been
     corruptted already */
 static u8 *syslog_msg = 0;

 static void
 unix_signal_handler (int signum, siginfo_t * si, ucontext_t * uc)
 {
   uword fatal = 0;

   syslog_msg = format (syslog_msg, "received signal %U, PC %U",
 		       format_signal, signum, format_ucontext_pc, uc);

   if (signum == SIGSEGV)
     syslog_msg = format (syslog_msg, ", faulting address %p", si->si_addr);

   switch (signum)
     {
       /* these (caught) signals cause the application to exit */
     case SIGTERM:
       if (unix_main.vlib_main->main_loop_exit_set)
 	{
 	  syslog (LOG_ERR | LOG_DAEMON, "received SIGTERM, exiting...");
 	  unix_main.vlib_main->main_loop_exit_now = 1;
 	}
       break;
       /* fall through */
     case SIGQUIT:
     case SIGINT:
     case SIGILL:
     case SIGBUS:
     case SIGSEGV:
     case SIGHUP:
     case SIGFPE:
     case SIGABRT:
       fatal = 1;
       break;

       /* by default, print a message and continue */
     default:
       fatal = 0;
       break;
     }

   /* Null terminate. */
   vec_add1 (syslog_msg, 0);

   if (fatal)
     {
       syslog (LOG_ERR | LOG_DAEMON, "%s", syslog_msg);

       /* Address of callers: outer first, inner last. */
       uword callers[15];
       uword n_callers = clib_backtrace (callers, ARRAY_LEN (callers), 0);
       int i;
       for (i = 0; i < n_callers; i++)
 	{
 	  vec_reset_length (syslog_msg);

 	  syslog_msg =
 	    format (syslog_msg, "#%-2d 0x%016lx %U%c", i, callers[i],
 		    format_clib_elf_symbol_with_address, callers[i], 0);

 	  syslog (LOG_ERR | LOG_DAEMON, "%s", syslog_msg);
 	}

       /* have to remove SIGABRT to avoid recusive - os_exit calling abort() */
       unsetup_signal_handlers (SIGABRT);

       os_exit (1);
     }
   else
     clib_warning ("%s", syslog_msg);

 }

 static clib_error_t *
 setup_signal_handlers (unix_main_t * um)
 {
   uword i;
   struct sigaction sa;

   /* give a big enough buffer for msg, most likely it can avoid vec_resize  */
   vec_alloc (syslog_msg, 2048);

   for (i = 1; i < 32; i++)
     {
       clib_memset (&sa, 0, sizeof (sa));
       sa.sa_sigaction = (void *) unix_signal_handler;
       sa.sa_flags = SA_SIGINFO;

       switch (i)
 	{
 	  /* these signals take the default action */
 	case SIGKILL:
 	case SIGSTOP:
 	case SIGUSR1:
 	case SIGUSR2:
 	  continue;

 	  /* ignore SIGPIPE, SIGCHLD */
 	case SIGPIPE:
 	case SIGCHLD:
 	  sa.sa_sigaction = (void *) SIG_IGN;
 	  break;

 	  /* catch and handle all other signals */
 	default:
 	  break;
 	}

       if (sigaction (i, &sa, 0) < 0)
 	return clib_error_return_unix (0, "sigaction %U", format_signal, i);
     }

   return 0;
 }

 static void
 unix_error_handler (void *arg, u8 * msg, int msg_len)
 {
   unix_main_t *um = arg;

   /* Echo to stderr when interactive. */
   if (um->flags & UNIX_FLAG_INTERACTIVE)
     {
       CLIB_UNUSED (int r) = write (2, msg, msg_len);
     }
   else
     {
       char save = msg[msg_len - 1];

       /* Null Terminate. */
       msg[msg_len - 1] = 0;

       syslog (LOG_ERR | LOG_DAEMON, "%s", msg);

       msg[msg_len - 1] = save;
     }
 }

 void
 vlib_unix_error_report (vlib_main_t * vm, clib_error_t * error)
 {
   unix_main_t *um = &unix_main;

   if (um->flags & UNIX_FLAG_INTERACTIVE || error == 0)
     return;

   {
     char save;
     u8 *msg;
     u32 msg_len;

     msg = error->what;
     msg_len = vec_len (msg);

     /* Null Terminate. */
     save = msg[msg_len - 1];
     msg[msg_len - 1] = 0;

     syslog (LOG_ERR | LOG_DAEMON, "%s", msg);

     msg[msg_len - 1] = save;
   }
 }

 static uword
 startup_config_process (vlib_main_t * vm,
 			vlib_node_runtime_t * rt, vlib_frame_t * f)
 {
   unix_main_t *um = &unix_main;
   u8 *buf = 0;
   uword l, n = 1;

   vlib_process_suspend (vm, 2.0);

   while (um->unix_config_complete == 0)
     vlib_process_suspend (vm, 0.1);

   if (um->startup_config_filename)
     {
       unformat_input_t sub_input;
       int fd;
       struct stat s;
       char *fn = (char *) um->startup_config_filename;

       fd = open (fn, O_RDONLY);
       if (fd < 0)
 	{
 	  clib_warning ("failed to open `%s'", fn);
 	  return 0;
 	}

       if (fstat (fd, &s) < 0)
 	{
 	  clib_warning ("failed to stat `%s'", fn);
 	bail:
 	  close (fd);
 	  return 0;
 	}

       if (!(S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
 	{
 	  clib_warning ("not a regular file: `%s'", fn);
 	  goto bail;
 	}

       while (n > 0)
 	{
 	  l = vec_len (buf);
 	  vec_resize (buf, 4096);
 	  n = read (fd, buf + l, 4096);
 	  if (n > 0)
 	    {
 	      _vec_len (buf) = l + n;
 	      if (n < 4096)
 		break;
 	    }
 	  else
 	    break;
 	}
       if (um->log_fd && vec_len (buf))
 	{
 	  u8 *lv = 0;
 	  lv = format (lv, "%U: ***** Startup Config *****\n%v",
 		       format_timeval, 0 /* current bat-time */ ,
 		       0 /* current bat-format */ ,
 		       buf);
 	  {
 	    int rv __attribute__ ((unused)) =
 	      write (um->log_fd, lv, vec_len (lv));
 	  }
 	  vec_reset_length (lv);
 	  lv = format (lv, "%U: ***** End Startup Config *****\n",
 		       format_timeval, 0 /* current bat-time */ ,
 		       0 /* current bat-format */ );
 	  {
 	    int rv __attribute__ ((unused)) =
 	      write (um->log_fd, lv, vec_len (lv));
 	  }
 	  vec_free (lv);
 	}

       if (vec_len (buf))
 	{
 	  unformat_init_vector (&sub_input, buf);
 	  vlib_cli_input (vm, &sub_input, 0, 0);
 	  /* frees buf for us */
 	  unformat_free (&sub_input);
 	}
       close (fd);
     }
   return 0;
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (startup_config_node,static) = {
     .function = startup_config_process,
     .type = VLIB_NODE_TYPE_PROCESS,
     .name = "startup-config-process",
 };
 /* *INDENT-ON* */

 static clib_error_t *
 unix_config (vlib_main_t * vm, unformat_input_t * input)
 {
   unix_main_t *um = &unix_main;
   clib_error_t *error = 0;
   gid_t gid;
   int pidfd = -1;

   /* Defaults */
   um->cli_pager_buffer_limit = UNIX_CLI_DEFAULT_PAGER_LIMIT;
   um->cli_history_limit = UNIX_CLI_DEFAULT_HISTORY;

   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
       char *cli_prompt;
       if (unformat (input, "interactive"))
 	um->flags |= UNIX_FLAG_INTERACTIVE;
       else if (unformat (input, "nodaemon"))
 	um->flags |= UNIX_FLAG_NODAEMON;
       else if (unformat (input, "cli-prompt %s", &cli_prompt))
 	vlib_unix_cli_set_prompt (cli_prompt);
       else
 	if (unformat (input, "cli-listen %s", &um->cli_listen_socket.config))
 	;
       else if (unformat (input, "runtime-dir %s", &um->runtime_dir))
 	;
       else if (unformat (input, "cli-line-mode"))
 	um->cli_line_mode = 1;
       else if (unformat (input, "cli-no-banner"))
 	um->cli_no_banner = 1;
       else if (unformat (input, "cli-no-pager"))
 	um->cli_no_pager = 1;
       else if (unformat (input, "poll-sleep-usec %d", &um->poll_sleep_usec))
 	;
       else if (unformat (input, "cli-pager-buffer-limit %d",
 			 &um->cli_pager_buffer_limit))
 	;
       else
 	if (unformat (input, "cli-history-limit %d", &um->cli_history_limit))
 	;
       else if (unformat (input, "coredump-size"))
 	{
 	  uword coredump_size = 0;
 	  if (unformat (input, "unlimited"))
 	    {
 	      coredump_size = RLIM_INFINITY;
 	    }
 	  else
 	    if (!unformat (input, "%U", unformat_memory_size, &coredump_size))
 	    {
 	      return clib_error_return (0,
 					"invalid coredump-size parameter `%U'",
 					format_unformat_error, input);
 	    }
 	  const struct rlimit new_limit = { coredump_size, coredump_size };
 	  if (0 != setrlimit (RLIMIT_CORE, &new_limit))
 	    {
 	      clib_unix_warning ("prlimit() failed");
 	    }
 	}
       else if (unformat (input, "full-coredump"))
 	{
 	  int fd;

 	  fd = open ("/proc/self/coredump_filter", O_WRONLY);
 	  if (fd >= 0)
 	    {
 	      if (write (fd, "0x6f\n", 5) != 5)
 		clib_unix_warning ("coredump filter write failed!");
 	      close (fd);
 	    }
 	  else
 	    clib_unix_warning ("couldn't open /proc/self/coredump_filter");
 	}
       else if (unformat (input, "startup-config %s",
 			 &um->startup_config_filename))
 	;
       else if (unformat (input, "exec %s", &um->startup_config_filename))
 	;
       else if (unformat (input, "log %s", &um->log_filename))
 	{
 	  um->log_fd = open ((char *) um->log_filename,
 			     O_CREAT | O_WRONLY | O_APPEND, 0644);
 	  if (um->log_fd < 0)
 	    {
 	      clib_warning ("couldn't open log '%s'\n", um->log_filename);
 	      um->log_fd = 0;
 	    }
 	  else
 	    {
 	      u8 *lv = 0;
 	      lv = format (0, "%U: ***** Start: PID %d *****\n",
 			   format_timeval, 0 /* current bat-time */ ,
 			   0 /* current bat-format */ ,
 			   getpid ());
 	      {
 		int rv __attribute__ ((unused)) =
 		  write (um->log_fd, lv, vec_len (lv));
 	      }
 	      vec_free (lv);
 	    }
 	}
       else if (unformat (input, "gid %U", unformat_unix_gid, &gid))
 	{
 	  if (setegid (gid) == -1)
 	    return clib_error_return_unix (0, "setegid");
 	}
       else if (unformat (input, "pidfile %s", &um->pidfile))
 	;
       else
 	return clib_error_return (0, "unknown input `%U'",
 				  format_unformat_error, input);
     }

   if (um->runtime_dir == 0)
     {
       uid_t uid = geteuid ();
       if (uid == 00)
 	um->runtime_dir = format (0, "/run/%s%c",
 				  vlib_default_runtime_dir, 0);
       else
 	um->runtime_dir = format (0, "/run/user/%u/%s%c", uid,
 				  vlib_default_runtime_dir, 0);
     }

   error = setup_signal_handlers (um);
   if (error)
     return error;

   if (um->pidfile)
     {
       if ((error = vlib_unix_validate_runtime_file (um,
 						    (char *) um->pidfile,
 						    &um->pidfile)))
 	return error;

       if (((pidfd = open ((char *) um->pidfile,
 			  O_CREAT | O_WRONLY | O_TRUNC, 0644)) < 0))
 	{
 	  return clib_error_return_unix (0, "open");
 	}
     }

   if (!(um->flags & UNIX_FLAG_INTERACTIVE))
     {
       openlog (vm->name, LOG_CONS | LOG_PERROR | LOG_PID, LOG_DAEMON);
       clib_error_register_handler (unix_error_handler, um);

       if (!(um->flags & UNIX_FLAG_NODAEMON) && daemon ( /* chdir to / */ 0,
 						       /* stdin/stdout/stderr -> /dev/null */
 						       0) < 0)
 	clib_error_return (0, "daemon () fails");
     }

   if (pidfd >= 0)
     {
       u8 *lv = format (0, "%d", getpid ());
       if (write (pidfd, (char *) lv, vec_len (lv)) != vec_len (lv))
 	{
 	  vec_free (lv);
 	  close (pidfd);
 	  return clib_error_return_unix (0, "write");
 	}
       vec_free (lv);
       close (pidfd);
     }

   um->unix_config_complete = 1;

   return 0;
 }

 /* unix { ... } configuration. */
 /*?
  *
  * @cfgcmd{interactive}
  * Attach CLI to stdin/out and provide a debugging command line interface.
  * Implies @c nodaemon.
  *
  * @cfgcmd{nodaemon}
  * Do not fork or background the VPP process. Typically used when invoking
  * VPP applications from a process monitor.
  *
  * @cfgcmd{exec, &lt;filename&gt;}
  * @par <code>startup-config &lt;filename&gt;</code>
  * Read startup operational configuration from @c filename.
  * The contents of the file will be performed as though entered at the CLI.
  * The two keywords are aliases for the same function; if both are specified,
  * only the last will have an effect.
  *
  * @cfgcmd{log, &lt;filename&gt;}
  * Logs the startup configuration and all subsequent CLI commands in
  * @c filename.
  * Very useful in situations where folks don't remember or can't be bothered
  * to include CLI commands in bug reports.
  *
  * @cfgcmd{pidfile, &lt;filename&gt;}
  * Writes the pid of the main thread in @c filename.
  *
  * @cfgcmd{full-coredump}
  * Ask the Linux kernel to dump all memory-mapped address regions, instead
  * of just text+data+bss.
  *
  * @cfgcmd{runtime-dir}
  * Define directory where VPP is going to store all runtime files.
  * Default is /run/vpp.
  *
  * @cfgcmd{cli-listen, &lt;address:port&gt;}
  * Bind the CLI to listen at the address and port given. @clocalhost
  * on TCP port @c 5002, given as <tt>cli-listen localhost:5002</tt>,
  * is typical.
  *
  * @cfgcmd{cli-line-mode}
  * Disable character-by-character I/O on stdin. Useful when combined with,
  * for example, <tt>emacs M-x gud-gdb</tt>.
  *
  * @cfgcmd{cli-prompt, &lt;string&gt;}
  * Configure the CLI prompt to be @c string.
  *
  * @cfgcmd{cli-history-limit, &lt;nn&gt;}
  * Limit commmand history to @c nn  lines. A value of @c 0
  * disables command history. Default value: @c 50
  *
  * @cfgcmd{cli-no-banner}
  * Disable the login banner on stdin and Telnet connections.
  *
  * @cfgcmd{cli-no-pager}
  * Disable the output pager.
  *
  * @cfgcmd{cli-pager-buffer-limit, &lt;nn&gt;}
  * Limit pager buffer to @c nn lines of output.
  * A value of @c 0 disables the pager. Default value: @c 100000
 ?*/
 VLIB_EARLY_CONFIG_FUNCTION (unix_config, "unix");

 static clib_error_t *
 unix_exit (vlib_main_t * vm)
 {
   /* Close syslog connection. */
   closelog ();
   return 0;
 }

 VLIB_MAIN_LOOP_EXIT_FUNCTION (unix_exit);

 u8 **vlib_thread_stacks;

 static uword
 thread0 (uword arg)
 {
   vlib_main_t *vm = (vlib_main_t *) arg;
   unformat_input_t input;
   int i;

   unformat_init_command_line (&input, (char **) vm->argv);
   i = vlib_main (vm, &input);
   unformat_free (&input);

   return i;
 }

 u8 *
 vlib_thread_stack_init (uword thread_index)
 {
   vec_validate (vlib_thread_stacks, thread_index);
   vlib_thread_stacks[thread_index] = clib_mem_alloc_aligned
     (VLIB_THREAD_STACK_SIZE, VLIB_THREAD_STACK_SIZE);

   /*
    * Disallow writes to the bottom page of the stack, to
    * catch stack overflows.
    */
   if (mprotect (vlib_thread_stacks[thread_index],
 		clib_mem_get_page_size (), PROT_READ) < 0)
     clib_unix_warning ("thread stack");
   return vlib_thread_stacks[thread_index];
 }

 int
 vlib_unix_main (int argc, char *argv[])
 {
   vlib_main_t *vm = &vlib_global_main;	/* one and only time for this! */
   unformat_input_t input;
   clib_error_t *e;
   int i;

   vm->argv = (u8 **) argv;
   vm->name = argv[0];
   vm->heap_base = clib_mem_get_heap ();
   vm->heap_aligned_base = (void *)
     (((uword) vm->heap_base) & ~(VLIB_FRAME_ALIGN - 1));
   ASSERT (vm->heap_base);

   unformat_init_command_line (&input, (char **) vm->argv);
   if ((e = vlib_plugin_config (vm, &input)))
     {
       clib_error_report (e);
       return 1;
     }
   unformat_free (&input);

   i = vlib_plugin_early_init (vm);
   if (i)
     return i;

   unformat_init_command_line (&input, (char **) vm->argv);
   if (vm->init_functions_called == 0)
     vm->init_functions_called = hash_create (0, /* value bytes */ 0);
   e = vlib_call_all_config_functions (vm, &input, 1 /* early */ );
   if (e != 0)
     {
       clib_error_report (e);
       return 1;
     }
   unformat_free (&input);

   /* always load symbols, for signal handler and mheap memory get/put backtrace */
   clib_elf_main_init (vm->name);

   vlib_thread_stack_init (0);

   __os_thread_index = 0;
   vm->thread_index = 0;

   i = clib_calljmp (thread0, (uword) vm,
 		    (void *) (vlib_thread_stacks[0] +
 			      VLIB_THREAD_STACK_SIZE));
   return i;
 }

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* Copyright (c) 2015 Cisco and/or its affiliates.
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at:
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	/*
	* main.c: Unix main routine
	*
	* Copyright (c) 2008 Eliot Dresselhaus
	*
	* Permission is hereby granted, free of charge, to any person obtaining
	* a copy of this software and associated documentation files (the
	* "Software"), to deal in the Software without restriction, including
	* without limitation the rights to use, copy, modify, merge, publish,
	* distribute, sublicense, and/or sell copies of the Software, and to
	* permit persons to whom the Software is furnished to do so, subject to
	* the following conditions:
	*
	* The above copyright notice and this permission notice shall be
	* included in all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
	* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
	* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
	* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*/
	#include <vlib/vlib.h>
	#include <vlib/unix/unix.h>
	#include <vlib/unix/plugin.h>

	#include <signal.h>
	#include <sys/ucontext.h>
	#include <syslog.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <sys/time.h>
	#include <sys/resource.h>
	#include <unistd.h>

	/** Default CLI pager limit is not configured in startup.conf */
	#define UNIX_CLI_DEFAULT_PAGER_LIMIT 100000

	/** Default CLI history depth if not configured in startup.conf */
	#define UNIX_CLI_DEFAULT_HISTORY 50

	char *vlib_default_runtime_dir __attribute__ ((weak));
	char *vlib_default_runtime_dir = "vlib";

	unix_main_t unix_main;
	clib_file_main_t file_main;
	vlib_physmem_main_t physmem_main;

	static clib_error_t *
	unix_main_init (vlib_main_t * vm)
	{
	unix_main_t *um = &unix_main;
	um->vlib_main = vm;
	return vlib_call_init_function (vm, unix_input_init);
	}

	VLIB_INIT_FUNCTION (unix_main_init);

	static int
	unsetup_signal_handlers (int sig)
	{
	struct sigaction sa;

	sa.sa_handler = SIG_DFL;
	sa.sa_flags = 0;
	sigemptyset (&sa.sa_mask);
	return sigaction (sig, &sa, 0);
	}


	/* allocate this buffer from mheap when setting up the signal handler.
	dangerous to vec_resize it when crashing, mheap itself might have been
	corruptted already */
	static u8 *syslog_msg = 0;

	static void
	unix_signal_handler (int signum, siginfo_t * si, ucontext_t * uc)
	{
	uword fatal = 0;

	syslog_msg = format (syslog_msg, "received signal %U, PC %U",
	format_signal, signum, format_ucontext_pc, uc);

	if (signum == SIGSEGV)
	syslog_msg = format (syslog_msg, ", faulting address %p", si->si_addr);

	switch (signum)
	{
	/* these (caught) signals cause the application to exit */
	case SIGTERM:
	if (unix_main.vlib_main->main_loop_exit_set)
	{
	syslog (LOG_ERR \| LOG_DAEMON, "received SIGTERM, exiting...");
	unix_main.vlib_main->main_loop_exit_now = 1;
	}
	break;
	/* fall through */
	case SIGQUIT:
	case SIGINT:
	case SIGILL:
	case SIGBUS:
	case SIGSEGV:
	case SIGHUP:
	case SIGFPE:
	case SIGABRT:
	fatal = 1;
	break;

	/* by default, print a message and continue */
	default:
	fatal = 0;
	break;
	}

	/* Null terminate. */
	vec_add1 (syslog_msg, 0);

	if (fatal)
	{
	syslog (LOG_ERR \| LOG_DAEMON, "%s", syslog_msg);

	/* Address of callers: outer first, inner last. */
	uword callers[15];
	uword n_callers = clib_backtrace (callers, ARRAY_LEN (callers), 0);
	int i;
	for (i = 0; i < n_callers; i++)
	{
	vec_reset_length (syslog_msg);

	syslog_msg =
	format (syslog_msg, "#%-2d 0x%016lx %U%c", i, callers[i],
	format_clib_elf_symbol_with_address, callers[i], 0);

	syslog (LOG_ERR \| LOG_DAEMON, "%s", syslog_msg);
	}

	/* have to remove SIGABRT to avoid recusive - os_exit calling abort() */
	unsetup_signal_handlers (SIGABRT);

	os_exit (1);
	}
	else
	clib_warning ("%s", syslog_msg);

	}

	static clib_error_t *
	setup_signal_handlers (unix_main_t * um)
	{
	uword i;
	struct sigaction sa;

	/* give a big enough buffer for msg, most likely it can avoid vec_resize */
	vec_alloc (syslog_msg, 2048);

	for (i = 1; i < 32; i++)
	{
	clib_memset (&sa, 0, sizeof (sa));
	sa.sa_sigaction = (void *) unix_signal_handler;
	sa.sa_flags = SA_SIGINFO;

	switch (i)
	{
	/* these signals take the default action */
	case SIGKILL:
	case SIGSTOP:
	case SIGUSR1:
	case SIGUSR2:
	continue;

	/* ignore SIGPIPE, SIGCHLD */
	case SIGPIPE:
	case SIGCHLD:
	sa.sa_sigaction = (void *) SIG_IGN;
	break;

	/* catch and handle all other signals */
	default:
	break;
	}

	if (sigaction (i, &sa, 0) < 0)
	return clib_error_return_unix (0, "sigaction %U", format_signal, i);
	}

	return 0;
	}

	static void
	unix_error_handler (void arg, u8 msg, int msg_len)
	{
	unix_main_t *um = arg;

	/* Echo to stderr when interactive. */
	if (um->flags & UNIX_FLAG_INTERACTIVE)
	{
	CLIB_UNUSED (int r) = write (2, msg, msg_len);
	}
	else
	{
	char save = msg[msg_len - 1];

	/* Null Terminate. */
	msg[msg_len - 1] = 0;

	syslog (LOG_ERR \| LOG_DAEMON, "%s", msg);

	msg[msg_len - 1] = save;
	}
	}

	void
	vlib_unix_error_report (vlib_main_t * vm, clib_error_t * error)
	{
	unix_main_t *um = &unix_main;

	if (um->flags & UNIX_FLAG_INTERACTIVE \|\| error == 0)
	return;

	{
	char save;
	u8 *msg;
	u32 msg_len;

	msg = error->what;
	msg_len = vec_len (msg);

	/* Null Terminate. */
	save = msg[msg_len - 1];
	msg[msg_len - 1] = 0;

	syslog (LOG_ERR \| LOG_DAEMON, "%s", msg);

	msg[msg_len - 1] = save;
	}
	}

	static uword
	startup_config_process (vlib_main_t * vm,
	vlib_node_runtime_t * rt, vlib_frame_t * f)
	{
	unix_main_t *um = &unix_main;
	u8 *buf = 0;
	uword l, n = 1;

	vlib_process_suspend (vm, 2.0);

	while (um->unix_config_complete == 0)
	vlib_process_suspend (vm, 0.1);

	if (um->startup_config_filename)
	{
	unformat_input_t sub_input;
	int fd;
	struct stat s;
	char fn = (char ) um->startup_config_filename;

	fd = open (fn, O_RDONLY);
	if (fd < 0)
	{
	clib_warning ("failed to open `%s'", fn);
	return 0;
	}

	if (fstat (fd, &s) < 0)
	{
	clib_warning ("failed to stat `%s'", fn);
	bail:
	close (fd);
	return 0;
	}

	if (!(S_ISREG (s.st_mode) \|\| S_ISLNK (s.st_mode)))
	{
	clib_warning ("not a regular file: `%s'", fn);
	goto bail;
	}

	while (n > 0)
	{
	l = vec_len (buf);
	vec_resize (buf, 4096);
	n = read (fd, buf + l, 4096);
	if (n > 0)
	{
	_vec_len (buf) = l + n;
	if (n < 4096)
	break;
	}
	else
	break;
	}
	if (um->log_fd && vec_len (buf))
	{
	u8 *lv = 0;
	lv = format (lv, "%U: *** Startup Config ***\n%v",
	format_timeval, 0 /* current bat-time */ ,
	0 /* current bat-format */ ,
	buf);
	{
	int rv __attribute__ ((unused)) =
	write (um->log_fd, lv, vec_len (lv));
	}
	vec_reset_length (lv);
	lv = format (lv, "%U: *** End Startup Config ***\n",
	format_timeval, 0 /* current bat-time */ ,
	0 /* current bat-format */ );
	{
	int rv __attribute__ ((unused)) =
	write (um->log_fd, lv, vec_len (lv));
	}
	vec_free (lv);
	}

	if (vec_len (buf))
	{
	unformat_init_vector (&sub_input, buf);
	vlib_cli_input (vm, &sub_input, 0, 0);
	/* frees buf for us */
	unformat_free (&sub_input);
	}
	close (fd);
	}
	return 0;
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (startup_config_node,static) = {
	.function = startup_config_process,
	.type = VLIB_NODE_TYPE_PROCESS,
	.name = "startup-config-process",
	};
	/* INDENT-ON */

	static clib_error_t *
	unix_config (vlib_main_t * vm, unformat_input_t * input)
	{
	unix_main_t *um = &unix_main;
	clib_error_t *error = 0;
	gid_t gid;
	int pidfd = -1;

	/* Defaults */
	um->cli_pager_buffer_limit = UNIX_CLI_DEFAULT_PAGER_LIMIT;
	um->cli_history_limit = UNIX_CLI_DEFAULT_HISTORY;

	while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
	{
	char *cli_prompt;
	if (unformat (input, "interactive"))
	um->flags \|= UNIX_FLAG_INTERACTIVE;
	else if (unformat (input, "nodaemon"))
	um->flags \|= UNIX_FLAG_NODAEMON;
	else if (unformat (input, "cli-prompt %s", &cli_prompt))
	vlib_unix_cli_set_prompt (cli_prompt);
	else
	if (unformat (input, "cli-listen %s", &um->cli_listen_socket.config))
	;
	else if (unformat (input, "runtime-dir %s", &um->runtime_dir))
	;
	else if (unformat (input, "cli-line-mode"))
	um->cli_line_mode = 1;
	else if (unformat (input, "cli-no-banner"))
	um->cli_no_banner = 1;
	else if (unformat (input, "cli-no-pager"))
	um->cli_no_pager = 1;
	else if (unformat (input, "poll-sleep-usec %d", &um->poll_sleep_usec))
	;
	else if (unformat (input, "cli-pager-buffer-limit %d",
	&um->cli_pager_buffer_limit))
	;
	else
	if (unformat (input, "cli-history-limit %d", &um->cli_history_limit))
	;
	else if (unformat (input, "coredump-size"))
	{
	uword coredump_size = 0;
	if (unformat (input, "unlimited"))
	{
	coredump_size = RLIM_INFINITY;
	}
	else
	if (!unformat (input, "%U", unformat_memory_size, &coredump_size))
	{
	return clib_error_return (0,
	"invalid coredump-size parameter `%U'",
	format_unformat_error, input);
	}
	const struct rlimit new_limit = { coredump_size, coredump_size };
	if (0 != setrlimit (RLIMIT_CORE, &new_limit))
	{
	clib_unix_warning ("prlimit() failed");
	}
	}
	else if (unformat (input, "full-coredump"))
	{
	int fd;

	fd = open ("/proc/self/coredump_filter", O_WRONLY);
	if (fd >= 0)
	{
	if (write (fd, "0x6f\n", 5) != 5)
	clib_unix_warning ("coredump filter write failed!");
	close (fd);
	}
	else
	clib_unix_warning ("couldn't open /proc/self/coredump_filter");
	}
	else if (unformat (input, "startup-config %s",
	&um->startup_config_filename))
	;
	else if (unformat (input, "exec %s", &um->startup_config_filename))
	;
	else if (unformat (input, "log %s", &um->log_filename))
	{
	um->log_fd = open ((char *) um->log_filename,
	O_CREAT \| O_WRONLY \| O_APPEND, 0644);
	if (um->log_fd < 0)
	{
	clib_warning ("couldn't open log '%s'\n", um->log_filename);
	um->log_fd = 0;
	}
	else
	{
	u8 *lv = 0;
	lv = format (0, "%U: *** Start: PID %d ***\n",
	format_timeval, 0 /* current bat-time */ ,
	0 /* current bat-format */ ,
	getpid ());
	{
	int rv __attribute__ ((unused)) =
	write (um->log_fd, lv, vec_len (lv));
	}
	vec_free (lv);
	}
	}
	else if (unformat (input, "gid %U", unformat_unix_gid, &gid))
	{
	if (setegid (gid) == -1)
	return clib_error_return_unix (0, "setegid");
	}
	else if (unformat (input, "pidfile %s", &um->pidfile))
	;
	else
	return clib_error_return (0, "unknown input `%U'",
	format_unformat_error, input);
	}

	if (um->runtime_dir == 0)
	{
	uid_t uid = geteuid ();
	if (uid == 00)
	um->runtime_dir = format (0, "/run/%s%c",
	vlib_default_runtime_dir, 0);
	else
	um->runtime_dir = format (0, "/run/user/%u/%s%c", uid,
	vlib_default_runtime_dir, 0);
	}

	error = setup_signal_handlers (um);
	if (error)
	return error;

	if (um->pidfile)
	{
	if ((error = vlib_unix_validate_runtime_file (um,
	(char *) um->pidfile,
	&um->pidfile)))
	return error;

	if (((pidfd = open ((char *) um->pidfile,
	O_CREAT \| O_WRONLY \| O_TRUNC, 0644)) < 0))
	{
	return clib_error_return_unix (0, "open");
	}
	}

	if (!(um->flags & UNIX_FLAG_INTERACTIVE))
	{
	openlog (vm->name, LOG_CONS \| LOG_PERROR \| LOG_PID, LOG_DAEMON);
	clib_error_register_handler (unix_error_handler, um);

	if (!(um->flags & UNIX_FLAG_NODAEMON) && daemon ( /* chdir to / */ 0,
	/* stdin/stdout/stderr -> /dev/null */
	0) < 0)
	clib_error_return (0, "daemon () fails");
	}

	if (pidfd >= 0)
	{
	u8 *lv = format (0, "%d", getpid ());
	if (write (pidfd, (char *) lv, vec_len (lv)) != vec_len (lv))
	{
	vec_free (lv);
	close (pidfd);
	return clib_error_return_unix (0, "write");
	}
	vec_free (lv);
	close (pidfd);
	}

	um->unix_config_complete = 1;

	return 0;
	}

	/* unix { ... } configuration. */
	/*?
	*
	* @cfgcmd{interactive}
	* Attach CLI to stdin/out and provide a debugging command line interface.
	* Implies @c nodaemon.
	*
	* @cfgcmd{nodaemon}
	* Do not fork or background the VPP process. Typically used when invoking
	* VPP applications from a process monitor.
	*
	* @cfgcmd{exec, <filename>}
	* @par <code>startup-config <filename></code>
	* Read startup operational configuration from @c filename.
	* The contents of the file will be performed as though entered at the CLI.
	* The two keywords are aliases for the same function; if both are specified,
	* only the last will have an effect.
	*
	* @cfgcmd{log, <filename>}
	* Logs the startup configuration and all subsequent CLI commands in
	* @c filename.
	* Very useful in situations where folks don't remember or can't be bothered
	* to include CLI commands in bug reports.
	*
	* @cfgcmd{pidfile, <filename>}
	* Writes the pid of the main thread in @c filename.
	*
	* @cfgcmd{full-coredump}
	* Ask the Linux kernel to dump all memory-mapped address regions, instead
	* of just text+data+bss.
	*
	* @cfgcmd{runtime-dir}
	* Define directory where VPP is going to store all runtime files.
	* Default is /run/vpp.
	*
	* @cfgcmd{cli-listen, <address:port>}
	* Bind the CLI to listen at the address and port given. @clocalhost
	* on TCP port @c 5002, given as <tt>cli-listen localhost:5002</tt>,
	* is typical.
	*
	* @cfgcmd{cli-line-mode}
	* Disable character-by-character I/O on stdin. Useful when combined with,
	* for example, <tt>emacs M-x gud-gdb</tt>.
	*
	* @cfgcmd{cli-prompt, <string>}
	* Configure the CLI prompt to be @c string.
	*
	* @cfgcmd{cli-history-limit, <nn>}
	* Limit commmand history to @c nn lines. A value of @c 0
	* disables command history. Default value: @c 50
	*
	* @cfgcmd{cli-no-banner}
	* Disable the login banner on stdin and Telnet connections.
	*
	* @cfgcmd{cli-no-pager}
	* Disable the output pager.
	*
	* @cfgcmd{cli-pager-buffer-limit, <nn>}
	* Limit pager buffer to @c nn lines of output.
	* A value of @c 0 disables the pager. Default value: @c 100000
	?*/
	VLIB_EARLY_CONFIG_FUNCTION (unix_config, "unix");

	static clib_error_t *
	unix_exit (vlib_main_t * vm)
	{
	/* Close syslog connection. */
	closelog ();
	return 0;
	}

	VLIB_MAIN_LOOP_EXIT_FUNCTION (unix_exit);

	u8 **vlib_thread_stacks;

	static uword
	thread0 (uword arg)
	{
	vlib_main_t vm = (vlib_main_t ) arg;
	unformat_input_t input;
	int i;

	unformat_init_command_line (&input, (char **) vm->argv);
	i = vlib_main (vm, &input);
	unformat_free (&input);

	return i;
	}

	u8 *
	vlib_thread_stack_init (uword thread_index)
	{
	vec_validate (vlib_thread_stacks, thread_index);
	vlib_thread_stacks[thread_index] = clib_mem_alloc_aligned
	(VLIB_THREAD_STACK_SIZE, VLIB_THREAD_STACK_SIZE);

	/*
	* Disallow writes to the bottom page of the stack, to
	* catch stack overflows.
	*/
	if (mprotect (vlib_thread_stacks[thread_index],
	clib_mem_get_page_size (), PROT_READ) < 0)
	clib_unix_warning ("thread stack");
	return vlib_thread_stacks[thread_index];
	}

	int
	vlib_unix_main (int argc, char *argv[])
	{
	vlib_main_t vm = &vlib_global_main; / one and only time for this! */
	unformat_input_t input;
	clib_error_t *e;
	int i;

	vm->argv = (u8 **) argv;
	vm->name = argv[0];
	vm->heap_base = clib_mem_get_heap ();
	vm->heap_aligned_base = (void *)
	(((uword) vm->heap_base) & ~(VLIB_FRAME_ALIGN - 1));
	ASSERT (vm->heap_base);

	unformat_init_command_line (&input, (char **) vm->argv);
	if ((e = vlib_plugin_config (vm, &input)))
	{
	clib_error_report (e);
	return 1;
	}
	unformat_free (&input);

	i = vlib_plugin_early_init (vm);
	if (i)
	return i;

	unformat_init_command_line (&input, (char **) vm->argv);
	if (vm->init_functions_called == 0)
	vm->init_functions_called = hash_create (0, /* value bytes */ 0);
	e = vlib_call_all_config_functions (vm, &input, 1 /* early */ );
	if (e != 0)
	{
	clib_error_report (e);
	return 1;
	}
	unformat_free (&input);

	/* always load symbols, for signal handler and mheap memory get/put backtrace */
	clib_elf_main_init (vm->name);

	vlib_thread_stack_init (0);

	__os_thread_index = 0;
	vm->thread_index = 0;

	i = clib_calljmp (thread0, (uword) vm,
	(void *) (vlib_thread_stacks[0] +
	VLIB_THREAD_STACK_SIZE));
	return i;
	}

	/*
	* fd.io coding-style-patch-verification: ON
	*
	* Local Variables:
	* eval: (c-set-style "gnu")
	* End:
	*/