bird/sysdep/unix/main.c
Maria Matejka ab089f4fb5 Conf: Better error message when reading iproute2 config
Reported by: Martin Weinelt <martin@darmstadt.freifunk.net>
2020-02-04 10:34:46 +01:00

925 lines
17 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 "filter/data.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");
if (setgroups(0, NULL) < 0)
die("setgroups: %m");
}
/*
* Reading the Configuration
*/
#ifdef PATH_IPROUTE_DIR
static inline void
add_num_const(char *name, int val, const char *file, const uint line)
{
struct f_val *v = cfg_alloc(sizeof(struct f_val));
*v = (struct f_val) { .type = T_INT, .val.i = val };
struct symbol *sym = cf_get_symbol(name);
if (sym->class && (sym->scope == conf_this_scope))
cf_error("Error reading value for %s from %s:%d: already defined", name, file, line);
cf_define_symbol(sym, SYM_CONSTANT | T_INT, val, v);
}
/* 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;
for (uint line = 1; fgets(buf, sizeof(buf), fp); line++)
{
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 < 'A' || *p > 'Z') && (*p < '0' || *p > '9') && (*p != '_'))
*p = '_';
add_num_const(namebuf, val, file, line);
}
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", (s64) 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 sig_atomic_t async_config_flag;
volatile sig_atomic_t async_dump_flag;
volatile sig_atomic_t 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");
}