* - Ring buffer: \ref ringbuffer.c, \ref ringbuffer.h,
* - Hashing: \ref hash.h, \ref sha1.h, \ref sha1.c,
* - Crypto: \ref crypt.c.
- *
+ * - Forward error correction: \ref fec.c
*/
#include <signal.h>
/** The file containing user information (public key, permissions). */
static char *user_list_file = NULL;
-static int mmd_shm_id;
/** The task responsible for server command handling. */
static void init_ipc_or_die(void)
{
void *shm;
- int ret = shm_new(sizeof(struct misc_meta_data));
+ int shmid, ret = shm_new(sizeof(struct misc_meta_data));
if (ret < 0)
goto err_out;
-
- ret = shm_attach(ret, ATTACH_RW, &shm);
+ shmid = ret;
+ ret = shm_attach(shmid, ATTACH_RW, &shm);
+ shm_destroy(shmid);
if (ret < 0)
goto err_out;
mmd = shm;
- mmd_shm_id = ret;
ret = mutex_new();
if (ret < 0)
void parse_config_or_die(int override)
{
char *home = para_homedir();
- int ret, ll = conf.loglevel_arg;
+ int ret;
char *cf;
daemon_close_log();
.initialize = 0,
.check_required = 1,
.check_ambiguity = 0,
- .print_errors = 1
+ .print_errors = !conf.daemon_given
};
server_cmdline_parser_config_file(cf, &conf, ¶ms);
conf.daemon_given = tmp;
daemon_set_logfile(conf.logfile_arg);
daemon_open_log_or_die();
}
- daemon_set_loglevel(ll);
+ daemon_set_loglevel(conf.loglevel_arg);
init_colors_or_die();
daemon_set_flag(DF_LOG_PID);
daemon_set_flag(DF_LOG_LL);
if (pid != mmd->afs_pid)
continue;
PARA_EMERG_LOG("fatal: afs died\n");
- goto genocide;
+ kill(0, SIGTERM);
+ goto cleanup;
}
break;
/* die on sigint/sigterm. Kill all children too. */
case SIGINT:
case SIGTERM:
PARA_EMERG_LOG("terminating on signal %d\n", st->signum);
-genocide:
kill(0, SIGTERM);
+ /*
+ * We must wait for afs because afs catches SIGINT/SIGTERM.
+ * Before reacting to the signal, afs might want to use the
+ * shared memory area and the mmd mutex. If we destroy this
+ * mutex too early and afs tries to lock the shared memory
+ * area, the call to mutex_lock() will fail and terminate the
+ * afs process. This leads to dirty osl tables.
+ *
+ * There's no such problem with the other children of the
+ * server process (the command handlers) as these reset their
+ * SIGINT/SIGTERM handlers to the default action, i.e. these
+ * processes get killed immediately by the above kill().
+ */
+ PARA_INFO_LOG("waiting for afs (pid %d) to die\n",
+ (int)mmd->afs_pid);
+ waitpid(mmd->afs_pid, NULL, 0);
+cleanup:
+ free(mmd->afd.afhi.chunk_table);
+ free(mmd->afd.afhi.info_string);
+ close_listed_fds();
mutex_destroy(mmd_mutex);
shm_detach(mmd);
- shm_destroy(mmd_shm_id);
-
exit(EXIT_FAILURE);
}
}
st->task.post_select = signal_post_select;
sprintf(st->task.status, "signal task");
+ PARA_NOTICE_LOG("setting up signal handling\n");
st->fd = para_signal_init(); /* always successful */
-
- PARA_NOTICE_LOG("setting up signal handlers\n");
- if (para_install_sighandler(SIGINT) < 0)
- goto err;
- if (para_install_sighandler(SIGTERM) < 0)
- goto err;
- if (para_install_sighandler(SIGHUP) < 0)
- goto err;
- if (para_install_sighandler(SIGCHLD) < 0)
- goto err;
- if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
- goto err;
- if (signal(SIGUSR1, SIG_IGN) == SIG_ERR)
- goto err;
+ para_install_sighandler(SIGINT);
+ para_install_sighandler(SIGTERM);
+ para_install_sighandler(SIGHUP);
+ para_install_sighandler(SIGCHLD);
+ para_sigaction(SIGPIPE, SIG_IGN);
add_close_on_fork_list(st->fd);
register_task(&st->task);
- return;
-err:
- PARA_EMERG_LOG("could not install signal handlers\n");
- exit(EXIT_FAILURE);
}
static void command_pre_select(struct sched *s, struct task *t)
int new_fd, ret, i;
char *peer_name;
pid_t child_pid;
+ uint32_t *chunk_table;
+ char *info_string;
if (!FD_ISSET(sct->listen_fd, &s->rfds))
return;
mmd->num_connects++;
mmd->active_connections++;
random();
+ /* The chunk table and the info_string are pointers located in the
+ * mmd struct that point to dynamically allocated memory that must be
+ * freed by the parent and the child. However, as the mmd struct is in
+ * a shared memory area, there's no guarantee that after the fork these
+ * pointers are still valid in child context. As these two pointers are
+ * not used in the child anyway, we save them to local variables and
+ * free the memory via that copy in the child.
+ */
+ info_string = mmd->afd.afhi.info_string;
+ chunk_table = mmd->afd.afhi.chunk_table;
child_pid = fork();
if (child_pid < 0) {
ret = -ERRNO_TO_PARA_ERROR(errno);
/* parent keeps accepting connections */
return;
}
+ /* mmd might already have changed at this point */
+ free(info_string);
+ free(chunk_table);
alarm(ALARM_TIMEOUT);
close_listed_fds();
para_signal_shutdown();
return afs_server_socket[0];
}
+__noreturn static void tmp_sigchld_handler(__a_unused int s)
+{
+ PARA_EMERG_LOG("caught early SIGCHLD\n");
+ exit(EXIT_FAILURE);
+}
+
static void server_init(int argc, char **argv)
{
struct server_cmdline_parser_params params = {
drop_privileges_or_die(conf.user_arg, conf.group_arg);
/* parse config file, open log and set defaults */
parse_config_or_die(0);
- log_welcome("para_server", conf.loglevel_arg);
+ log_welcome("para_server");
init_ipc_or_die(); /* init mmd struct and mmd->lock */
/* make sure, the global now pointer is uptodate */
gettimeofday(now, NULL);
daemonize();
PARA_NOTICE_LOG("initializing audio format handlers\n");
afh_init();
+
+ /*
+ * Although afs uses its own signal handling we must ignore SIGUSR1
+ * _before_ the afs child process gets born by init_afs() below. It's
+ * racy to do this in the child because the parent might send SIGUSR1
+ * before the child gets a chance to ignore this signal -- only the
+ * good die young.
+ */
+ para_sigaction(SIGUSR1, SIG_IGN);
+ /*
+ * We have to install a SIGCHLD handler before the afs process is being
+ * forked off. Otherwise, para_server does not notice if afs dies before
+ * the SIGCHLD handler has been installed by init_signal_task() below.
+ */
+ para_sigaction(SIGCHLD, tmp_sigchld_handler);
PARA_NOTICE_LOG("initializing the audio file selector\n");
afs_socket = init_afs();
init_signal_task();