bird/sysdep/unix/main.c
Ondrej Zajicek (work) 8a68316eb9 Nest: Add command to request graceful restart
When 'graceful down' command is entered, protocols are shut down
with regard to graceful restart. Namely Kernel protocol does
not remove routes and BGP protocol does not send notification,
just closes the connection.
2019-06-30 21:29:24 +02:00

919 lines
16 KiB
C

/*
* 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
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#include <pwd.h>
#include <grp.h>
#include <sys/stat.h>
#include <libgen.h>
#include "nest/bird.h"
#include "lib/lists.h"
#include "lib/resource.h"
#include "lib/socket.h"
#include "lib/event.h"
#include "lib/timer.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
*/
void
async_dump(void)
{
debug("INTERNAL STATE DUMP\n\n");
rdump(&root_pool);
sk_dump_all();
// XXXX tm_dump_all();
if_dump_all();
neigh_dump_all();
rta_dump_all();
rt_dump_all();
protos_dump_all();
debug("\n");
}
/*
* Dropping privileges
*/
#ifdef CONFIG_RESTRICTED_PRIVILEGES
#include CONFIG_INCLUDE_SYSPRIV_H
#else
static inline void
drop_uid(uid_t uid UNUSED)
{
die("Cannot change user on this platform");
}
#endif
static inline void
drop_gid(gid_t gid)
{
if (setgid(gid) < 0)
die("setgid: %m");
}
/*
* Reading the Configuration
*/
#ifdef PATH_IPROUTE_DIR
static inline void
add_num_const(char *name, int val)
{
struct symbol *s = cf_get_symbol(name);
s->class = SYM_CONSTANT | T_INT;
s->def = cfg_allocz(sizeof(struct f_val));
SYM_TYPE(s) = T_INT;
SYM_VAL(s).i = val;
}
/* the code of read_iproute_table() is based on
rtnl_tab_initialize() from iproute2 package */
static void
read_iproute_table(char *file, char *prefix, int max)
{
char buf[512], namebuf[512];
char *name;
int val;
FILE *fp;
strcpy(namebuf, prefix);
name = namebuf + strlen(prefix);
fp = fopen(file, "r");
if (!fp)
return;
while (fgets(buf, sizeof(buf), fp))
{
char *p = buf;
while (*p == ' ' || *p == '\t')
p++;
if (*p == '#' || *p == '\n' || *p == 0)
continue;
if (sscanf(p, "0x%x %s\n", &val, name) != 2 &&
sscanf(p, "0x%x %s #", &val, name) != 2 &&
sscanf(p, "%d %s\n", &val, name) != 2 &&
sscanf(p, "%d %s #", &val, name) != 2)
continue;
if (val < 0 || val > max)
continue;
for(p = name; *p; p++)
if ((*p < 'a' || *p > 'z') && (*p < '0' || *p > '9') && (*p != '_'))
*p = '_';
add_num_const(namebuf, val);
}
fclose(fp);
}
#endif // PATH_IPROUTE_DIR
static char *config_name = PATH_CONFIG_FILE;
static int
cf_read(byte *dest, uint len, int fd)
{
int l = read(fd, dest, len);
if (l < 0)
cf_error("Read error");
return l;
}
void
sysdep_preconfig(struct config *c)
{
init_list(&c->logfiles);
c->latency_limit = UNIX_DEFAULT_LATENCY_LIMIT;
c->watchdog_warning = UNIX_DEFAULT_WATCHDOG_WARNING;
#ifdef PATH_IPROUTE_DIR
read_iproute_table(PATH_IPROUTE_DIR "/rt_protos", "ipp_", 256);
read_iproute_table(PATH_IPROUTE_DIR "/rt_realms", "ipr_", 256);
read_iproute_table(PATH_IPROUTE_DIR "/rt_scopes", "ips_", 256);
read_iproute_table(PATH_IPROUTE_DIR "/rt_tables", "ipt_", 256);
#endif
}
int
sysdep_commit(struct config *new, struct config *old UNUSED)
{
log_switch(0, &new->logfiles, new->syslog_name);
return 0;
}
static int
unix_read_config(struct config **cp, char *name)
{
struct config *conf = config_alloc(name);
int ret;
*cp = conf;
conf->file_fd = open(name, O_RDONLY);
if (conf->file_fd < 0)
return 0;
cf_read_hook = cf_read;
ret = config_parse(conf);
close(conf->file_fd);
return ret;
}
static struct config *
read_config(void)
{
struct config *conf;
if (!unix_read_config(&conf, config_name))
{
if (conf->err_msg)
die("%s:%d:%d %s", conf->err_file_name, conf->err_lino, conf->err_chno, conf->err_msg);
else
die("Unable to open configuration file %s: %m", config_name);
}
return conf;
}
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:%d:%d %s", conf->err_file_name, conf->err_lino, conf->err_chno, 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, 0);
}
static struct config *
cmd_read_config(char *name)
{
struct config *conf;
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:%d:%d %s", conf->err_file_name, conf->err_lino, conf->err_chno, conf->err_msg);
else
cli_msg(8002, "%s: %m", name);
config_free(conf);
conf = NULL;
}
return conf;
}
void
cmd_check_config(char *name)
{
struct config *conf = cmd_read_config(name);
if (!conf)
return;
cli_msg(20, "Configuration OK");
config_free(conf);
}
static void
cmd_reconfig_msg(int r)
{
switch (r)
{
case CONF_DONE: cli_msg( 3, "Reconfigured"); break;
case CONF_PROGRESS: cli_msg( 4, "Reconfiguration in progress"); break;
case CONF_QUEUED: cli_msg( 5, "Reconfiguration already in progress, queueing new config"); break;
case CONF_UNQUEUED: cli_msg(17, "Reconfiguration already in progress, removing queued config"); break;
case CONF_CONFIRM: cli_msg(18, "Reconfiguration confirmed"); break;
case CONF_SHUTDOWN: cli_msg( 6, "Reconfiguration ignored, shutting down"); break;
case CONF_NOTHING: cli_msg(19, "Nothing to do"); break;
default: break;
}
}
/* Hack for scheduled undo notification */
cli *cmd_reconfig_stored_cli;
void
cmd_reconfig_undo_notify(void)
{
if (cmd_reconfig_stored_cli)
{
cli *c = cmd_reconfig_stored_cli;
cli_printf(c, CLI_ASYNC_CODE, "Config timeout expired, starting undo");
cli_write_trigger(c);
}
}
void
cmd_reconfig(char *name, int type, uint timeout)
{
if (cli_access_restricted())
return;
struct config *conf = cmd_read_config(name);
if (!conf)
return;
int r = config_commit(conf, type, timeout);
if ((r >= 0) && (timeout > 0))
{
cmd_reconfig_stored_cli = this_cli;
cli_msg(-22, "Undo scheduled in %d s", timeout);
}
cmd_reconfig_msg(r);
}
void
cmd_reconfig_confirm(void)
{
if (cli_access_restricted())
return;
int r = config_confirm();
cmd_reconfig_msg(r);
}
void
cmd_reconfig_undo(void)
{
if (cli_access_restricted())
return;
cli_msg(-21, "Undo requested");
int r = config_undo();
cmd_reconfig_msg(r);
}
void
cmd_reconfig_status(void)
{
int s = config_status();
btime t = config_timer_status();
switch (s)
{
case CONF_DONE: cli_msg(-3, "Daemon is up and running"); break;
case CONF_PROGRESS: cli_msg(-4, "Reconfiguration in progress"); break;
case CONF_QUEUED: cli_msg(-5, "Reconfiguration in progress, next one enqueued"); break;
case CONF_SHUTDOWN: cli_msg(-6, "Shutdown in progress"); break;
default: break;
}
if (t >= 0)
cli_msg(-22, "Configuration unconfirmed, undo in %t s", t);
cli_msg(0, "");
}
/*
* 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, uint 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, uint 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 */
s->fast_rx = 1;
c->rx_pos = c->rx_buf;
c->rx_aux = NULL;
rmove(s, c->pool);
return 1;
}
static void
cli_init_unix(uid_t use_uid, gid_t use_gid)
{
sock *s;
cli_init();
s = cli_sk = sk_new(cli_pool);
s->type = SK_UNIX_PASSIVE;
s->rx_hook = cli_connect;
s->rbsize = 1024;
s->fast_rx = 1;
/* Return value intentionally ignored */
unlink(path_control_socket);
if (sk_open_unix(s, path_control_socket) < 0)
die("Cannot create control socket %s: %m", path_control_socket);
if (use_uid || use_gid)
if (chown(path_control_socket, use_uid, use_gid) < 0)
die("chown: %m");
if (chmod(path_control_socket, 0660) < 0)
die("chmod: %m");
}
/*
* PID file
*/
static char *pid_file;
static int pid_fd;
static inline void
open_pid_file(void)
{
if (!pid_file)
return;
pid_fd = open(pid_file, O_WRONLY|O_CREAT, 0664);
if (pid_fd < 0)
die("Cannot create PID file %s: %m", pid_file);
}
static inline void
write_pid_file(void)
{
int pl, rv;
char ps[24];
if (!pid_file)
return;
/* We don't use PID file for uniqueness, so no need for locking */
pl = bsnprintf(ps, sizeof(ps), "%ld\n", (long) getpid());
if (pl < 0)
bug("PID buffer too small");
rv = ftruncate(pid_fd, 0);
if (rv < 0)
die("fruncate: %m");
rv = write(pid_fd, ps, pl);
if(rv < 0)
die("write: %m");
close(pid_fd);
}
static inline void
unlink_pid_file(void)
{
if (pid_file)
unlink(pid_file);
}
/*
* Shutdown
*/
void
cmd_shutdown(void)
{
if (cli_access_restricted())
return;
cli_msg(7, "Shutdown requested");
order_shutdown(0);
}
void
async_shutdown(void)
{
DBG("Shutting down...\n");
order_shutdown(0);
}
void
sysdep_shutdown_done(void)
{
unlink_pid_file();
unlink(path_control_socket);
log_msg(L_FATAL "Shutdown completed");
exit(0);
}
void
cmd_graceful_restart(void)
{
if (cli_access_restricted())
return;
cli_msg(25, "Graceful restart requested");
order_shutdown(1);
}
/*
* Signals
*/
volatile int async_config_flag;
volatile int async_dump_flag;
volatile int async_shutdown_flag;
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;
}
void watchdog_sigalrm(int sig UNUSED);
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);
sa.sa_handler = watchdog_sigalrm;
sa.sa_flags = 0;
sigaction(SIGALRM, &sa, NULL);
signal(SIGPIPE, SIG_IGN);
}
/*
* Parsing of command-line arguments
*/
static char *opt_list = "bc:dD:ps:P:u:g:flRh";
static int parse_and_exit;
char *bird_name;
static char *use_user;
static char *use_group;
static int run_in_foreground = 0;
static void
display_usage(void)
{
fprintf(stderr, "Usage: %s [--version] [--help] [-c <config-file>] [OPTIONS]\n", bird_name);
}
static void
display_help(void)
{
display_usage();
fprintf(stderr,
"\n"
"Options: \n"
" -c <config-file> Use given configuration file instead of\n"
" " PATH_CONFIG_FILE "\n"
" -d Enable debug messages and run bird in foreground\n"
" -D <debug-file> Log debug messages to given file instead of stderr\n"
" -f Run bird in foreground\n"
" -g <group> Use given group ID\n"
" -h, --help Display this information\n"
" -l Look for a configuration file and a control socket\n"
" in the current working directory\n"
" -p Test configuration file and exit without start\n"
" -P <pid-file> Create a PID file with given filename\n"
" -R Apply graceful restart recovery after start\n"
" -s <control-socket> Use given filename for a control socket\n"
" -u <user> Drop privileges and use given user ID\n"
" --version Display version of BIRD\n");
exit(0);
}
static void
display_version(void)
{
fprintf(stderr, "BIRD version " BIRD_VERSION "\n");
exit(0);
}
static inline char *
get_bird_name(char *s, char *def)
{
char *t;
if (!s)
return def;
t = strrchr(s, '/');
if (!t)
return s;
if (!t[1])
return def;
return t+1;
}
static inline uid_t
get_uid(const char *s)
{
struct passwd *pw;
char *endptr;
long int rv;
if (!s)
return 0;
errno = 0;
rv = strtol(s, &endptr, 10);
if (!errno && !*endptr)
return rv;
pw = getpwnam(s);
if (!pw)
die("Cannot find user '%s'", s);
return pw->pw_uid;
}
static inline gid_t
get_gid(const char *s)
{
struct group *gr;
char *endptr;
long int rv;
if (!s)
return 0;
errno = 0;
rv = strtol(s, &endptr, 10);
if (!errno && !*endptr)
return rv;
gr = getgrnam(s);
if (!gr)
die("Cannot find group '%s'", s);
return gr->gr_gid;
}
static void
parse_args(int argc, char **argv)
{
int config_changed = 0;
int socket_changed = 0;
int c;
bird_name = get_bird_name(argv[0], "bird");
if (argc == 2)
{
if (!strcmp(argv[1], "--version"))
display_version();
if (!strcmp(argv[1], "--help"))
display_help();
}
while ((c = getopt(argc, argv, opt_list)) >= 0)
switch (c)
{
case 'c':
config_name = optarg;
config_changed = 1;
break;
case 'd':
log_init_debug("");
run_in_foreground = 1;
break;
case 'D':
log_init_debug(optarg);
break;
case 'p':
parse_and_exit = 1;
break;
case 's':
path_control_socket = optarg;
socket_changed = 1;
break;
case 'P':
pid_file = optarg;
break;
case 'u':
use_user = optarg;
break;
case 'g':
use_group = optarg;
break;
case 'f':
run_in_foreground = 1;
break;
case 'l':
if (!config_changed)
config_name = xbasename(config_name);
if (!socket_changed)
path_control_socket = xbasename(path_control_socket);
break;
case 'R':
graceful_restart_recovery();
break;
case 'h':
display_help();
break;
default:
fputc('\n', stderr);
display_usage();
exit(1);
}
if (optind < argc)
{
display_usage();
exit(1);
}
}
/*
* Hic Est main()
*/
int
main(int argc, char **argv)
{
#ifdef HAVE_LIBDMALLOC
if (!getenv("DMALLOC_OPTIONS"))
dmalloc_debug(0x2f03d00);
#endif
parse_args(argc, argv);
log_switch(1, NULL, NULL);
net_init();
resource_init();
timer_init();
olock_init();
io_init();
rt_init();
if_init();
// roa_init();
config_init();
uid_t use_uid = get_uid(use_user);
gid_t use_gid = get_gid(use_group);
if (!parse_and_exit)
{
test_old_bird(path_control_socket);
cli_init_unix(use_uid, use_gid);
}
if (use_gid)
drop_gid(use_gid);
if (use_uid)
drop_uid(use_uid);
if (!parse_and_exit)
open_pid_file();
protos_build();
proto_build(&proto_unix_kernel);
proto_build(&proto_unix_iface);
struct config *conf = read_config();
if (parse_and_exit)
exit(0);
if (!run_in_foreground)
{
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);
}
main_thread_init();
write_pid_file();
signal_init();
config_commit(conf, RECONFIG_HARD, 0);
graceful_restart_init();
#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");
}