Internet on FIRE

/*

 *        BIRD Internet Routing Daemon -- Unix Entry Point

 *

 *        (c) 1998--2000 Martin Mares <mj@ucw.cz>

 *

 *        Can be freely distributed and used under the terms of the GNU GPL.

 */

#undef LOCAL_DEBUG

#include <stdio.h>

#include <stdlib.h>

#include <fcntl.h>

#include <unistd.h>

#include <signal.h>

#include "nest/bird.h"

#include "lib/lists.h"

#include "lib/resource.h"

#include "lib/socket.h"

#include "lib/event.h"

#include "lib/string.h"

#include "nest/route.h"

#include "nest/protocol.h"

#include "nest/iface.h"

#include "nest/cli.h"

#include "nest/locks.h"

#include "conf/conf.h"

#include "filter/filter.h"

#include "unix.h"

#include "krt.h"

/*

 *        Debugging

 */

#ifdef DEBUGGING

static int debug_flag = 1;

#else

static int debug_flag = 0;

#endif

void

async_dump(void)

{

  debug("INTERNAL STATE DUMP\n\n");

  rdump(&root_pool);

  sk_dump_all();

  tm_dump_all();

  if_dump_all();

  neigh_dump_all();

  rta_dump_all();

  rt_dump_all();

  protos_dump_all();

  debug("\n");

}

/*

 *        Reading the Configuration

 */

static int conf_fd;

static char *config_name = PATH_CONFIG;

static int

cf_read(byte *dest, unsigned int len)

{

  int l = read(conf_fd, dest, len);

  if (l < 0)

    cf_error("Read error");

  return l;

}

void

sysdep_preconfig(struct config *c)

{

  init_list(&c->logfiles);

}

int

sysdep_commit(struct config *new, struct config *old UNUSED)

{

  log_switch(debug_flag, &new->logfiles);

  return 0;

}

static int

unix_read_config(struct config **cp, char *name)

{

  struct config *conf = config_alloc(name);

  int ret;

  *cp = conf;

  conf_fd = open(name, O_RDONLY);

  if (conf_fd < 0)

    return 0;

  cf_read_hook = cf_read;

  ret = config_parse(conf);

  close(conf_fd);

  return ret;

}

static void

read_config(void)

{

  struct config *conf;

  if (!unix_read_config(&conf, config_name))

    {

      if (conf->err_msg)

        die("%s, line %d: %s", config_name, conf->err_lino, conf->err_msg);

      else

        die("Unable to open configuration file %s: %m", config_name);

    }

  config_commit(conf, RECONFIG_HARD);

}

void

async_config(void)

{

  struct config *conf;

  log(L_INFO "Reconfiguration requested by SIGHUP");

  if (!unix_read_config(&conf, config_name))

    {

      if (conf->err_msg)

        log(L_ERR "%s, line %d: %s", config_name, conf->err_lino, conf->err_msg);

      else

        log(L_ERR "Unable to open configuration file %s: %m", config_name);

      config_free(conf);

    }

  else

    config_commit(conf, RECONFIG_HARD);

}

void

cmd_reconfig(char *name, int type)

{

  struct config *conf;

  if (cli_access_restricted())

    return;

  if (!name)

    name = config_name;

  cli_msg(-2, "Reading configuration from %s", name);

  if (!unix_read_config(&conf, name))

    {

      if (conf->err_msg)

        cli_msg(8002, "%s, line %d: %s", name, conf->err_lino, conf->err_msg);

      else

        cli_msg(8002, "%s: %m", name);

      config_free(conf);

    }

  else

    {

      switch (config_commit(conf, type))

        {

        case CONF_DONE:

          cli_msg(3, "Reconfigured.");

          break;

        case CONF_PROGRESS:

          cli_msg(4, "Reconfiguration in progress.");

          break;

        case CONF_SHUTDOWN:

          cli_msg(6, "Reconfiguration ignored, shutting down.");

          break;

        default:

          cli_msg(5, "Reconfiguration already in progress, queueing new config");

        }

    }

}

/*

 *        Command-Line Interface

 */

static sock *cli_sk;

static char *path_control_socket = PATH_CONTROL_SOCKET;

static void

cli_write(cli *c)

{

  sock *s = c->priv;

  while (c->tx_pos)

    {

      struct cli_out *o = c->tx_pos;

      int len = o->wpos - o->outpos;

      s->tbuf = o->outpos;

      o->outpos = o->wpos;

      if (sk_send(s, len) <= 0)

        return;

      c->tx_pos = o->next;

    }

  /* Everything is written */

  s->tbuf = NULL;

  cli_written(c);

}

void

cli_write_trigger(cli *c)

{

  sock *s = c->priv;

  if (s->tbuf == NULL)

    cli_write(c);

}

static void

cli_tx(sock *s)

{

  cli_write(s->data);

}

int

cli_get_command(cli *c)

{

  sock *s = c->priv;

  byte *t = c->rx_aux ? : s->rbuf;

  byte *tend = s->rpos;

  byte *d = c->rx_pos;

  byte *dend = c->rx_buf + CLI_RX_BUF_SIZE - 2;

  while (t < tend)

    {

      if (*t == '\r')

        t++;

      else if (*t == '\n')

        {

          t++;

          c->rx_pos = c->rx_buf;

          c->rx_aux = t;

          *d = 0;

          return (d < dend) ? 1 : -1;

        }

      else if (d < dend)

        *d++ = *t++;

    }

  c->rx_aux = s->rpos = s->rbuf;

  c->rx_pos = d;

  return 0;

}

static int

cli_rx(sock *s, int size UNUSED)

{

  cli_kick(s->data);

  return 0;

}

static void

cli_err(sock *s, int err)

{

  if (config->cli_debug)

    {

      if (err)

        log(L_INFO "CLI connection dropped: %s", strerror(err));

      else

        log(L_INFO "CLI connection closed");

    }

  cli_free(s->data);

}

static int

cli_connect(sock *s, int size UNUSED)

{

  cli *c;

  if (config->cli_debug)

    log(L_INFO "CLI connect");

  s->rx_hook = cli_rx;

  s->tx_hook = cli_tx;

  s->err_hook = cli_err;

  s->data = c = cli_new(s);

  s->pool = c->pool;                /* We need to have all the socket buffers allocated in the cli pool */

  c->rx_pos = c->rx_buf;

  c->rx_aux = NULL;

  rmove(s, c->pool);

  return 1;

}

static void

cli_init_unix(void)

{

  sock *s;

  cli_init();

  s = cli_sk = sk_new(cli_pool);

  s->type = SK_UNIX_PASSIVE;

  s->rx_hook = cli_connect;

  s->rbsize = 1024;

  if (sk_open_unix(s, path_control_socket) < 0)

    die("Unable to create control socket %s", path_control_socket);

}

/*

 *        Shutdown

 */

void

cmd_shutdown(void)

{

  if (cli_access_restricted())

    return;

  cli_msg(7, "Shutdown requested");

  order_shutdown();

}

void

async_shutdown(void)

{

  DBG("Shutting down...\n");

  order_shutdown();

}

void

sysdep_shutdown_done(void)

{

  unlink(path_control_socket);

  log_msg(L_FATAL "Shutdown completed");

  exit(0);

}

/*

 *        Signals

 */

static void

handle_sighup(int sig UNUSED)

{

  DBG("Caught SIGHUP...\n");

  async_config_flag = 1;

}

static void

handle_sigusr(int sig UNUSED)

{

  DBG("Caught SIGUSR...\n");

  async_dump_flag = 1;

}

static void

handle_sigterm(int sig UNUSED)

{

  DBG("Caught SIGTERM...\n");

  async_shutdown_flag = 1;

}

static void

signal_init(void)

{

  struct sigaction sa;

  bzero(&sa, sizeof(sa));

  sa.sa_handler = handle_sigusr;

  sa.sa_flags = SA_RESTART;

  sigaction(SIGUSR1, &sa, NULL);

  sa.sa_handler = handle_sighup;

  sa.sa_flags = SA_RESTART;

  sigaction(SIGHUP, &sa, NULL);

  sa.sa_handler = handle_sigterm;

  sa.sa_flags = SA_RESTART;

  sigaction(SIGTERM, &sa, NULL);

  signal(SIGPIPE, SIG_IGN);

}

/*

 *        Parsing of command-line arguments

 */

static char *opt_list = "c:dD:ps:";

static void

usage(void)

{

  fprintf(stderr, "Usage: bird [-c <config-file>] [-d] [-D <debug-file>] [-p] [-s <control-socket>]\n");

  exit(1);

}

int parse_and_exit;

static void

parse_args(int argc, char **argv)

{

  int c;

  if (argc == 2)

    {

      if (!strcmp(argv[1], "--version"))

        {

          fprintf(stderr, "BIRD version " BIRD_VERSION "\n");

          exit(0);

        }

      if (!strcmp(argv[1], "--help"))

        usage();

    }

  while ((c = getopt(argc, argv, opt_list)) >= 0)

    switch (c)

      {

      case 'c':

        config_name = optarg;

        break;

      case 'd':

        debug_flag |= 1;

        break;

      case 'D':

        log_init_debug(optarg);

        debug_flag |= 2;

        break;

      case 'p':

        parse_and_exit = 1;

        break;

      case 's':

        path_control_socket = optarg;

        break;

      default:

        usage();

      }

  if (optind < argc)

    usage();

}

/*

 *        Hic Est main()

 */

int

main(int argc, char **argv)

{

#ifdef HAVE_LIBDMALLOC

  if (!getenv("DMALLOC_OPTIONS"))

    dmalloc_debug(0x2f03d00);

#endif

  parse_args(argc, argv);

  if (debug_flag == 1)

    log_init_debug("");

  log_init(debug_flag, 1);

  if (!parse_and_exit)

    test_old_bird(path_control_socket);

  DBG("Initializing.\n");

  resource_init();

  olock_init();

  io_init();

  rt_init();

  if_init();

  protos_build();

  proto_build(&proto_unix_kernel);

  proto_build(&proto_unix_iface);

  read_config();

  if (parse_and_exit)

    exit(0);

  if (!debug_flag)

    {

      pid_t pid = fork();

      if (pid < 0)

        die("fork: %m");

      if (pid)

        return 0;

      setsid();

      close(0);

      if (open("/dev/null", O_RDWR) < 0)

        die("Cannot open /dev/null: %m");

      dup2(0, 1);

      dup2(0, 2);

    }

  signal_init();

  cli_init_unix();

#ifdef LOCAL_DEBUG

  async_dump_flag = 1;

#endif

  log(L_INFO "Started");

  DBG("Entering I/O loop.\n");

  io_loop();

  bug("I/O loop died");

}