X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=server.c;h=a4115eb65734391128481f6fa421d548aba78e20;hp=4822ebb5c3066404e46f72b8154acc6f452bde04;hb=ad81d625737e1c096c154aedd8a1d161d3ee592e;hpb=3cfb1d880ebf22546486316cb74cce21f007eb07

diff --git a/server.c b/server.c
index 4822ebb5..a4115eb6 100644
--- a/server.c
+++ b/server.c
@@ -115,7 +115,6 @@ int mmd_mutex;
 
 /** 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. */
@@ -162,16 +161,16 @@ static void init_colors_or_die(void)
 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)
@@ -228,7 +227,7 @@ void parse_config_or_die(int override)
 			.initialize = 0,
 			.check_required = 1,
 			.check_ambiguity = 0,
-			.print_errors = 1
+			.print_errors = !conf.daemon_given
 		};
 		server_cmdline_parser_config_file(cf, &conf, &params);
 		conf.daemon_given = tmp;
@@ -301,10 +300,11 @@ static void signal_post_select(struct sched *s, struct task *t)
 		PARA_EMERG_LOG("terminating on signal %d\n", st->signum);
 genocide:
 		kill(0, SIGTERM);
+		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);
 	}
 }
@@ -331,8 +331,6 @@ static void init_signal_task(void)
 		goto err;
 	if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
 		goto err;
-	if (signal(SIGUSR1, SIG_IGN) == SIG_ERR)
-		goto err;
 	add_close_on_fork_list(st->fd);
 	register_task(&st->task);
 	return;
@@ -354,6 +352,8 @@ static void command_post_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;
@@ -366,6 +366,16 @@ static void command_post_select(struct sched *s, struct task *t)
 	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);
@@ -376,6 +386,9 @@ static void command_post_select(struct sched *s, struct task *t)
 		/* 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();
@@ -472,6 +485,12 @@ static int init_afs(void)
 	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 = {
@@ -502,6 +521,27 @@ static void server_init(int argc, char **argv)
 		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.
+	 */
+	if (signal(SIGUSR1, SIG_IGN) == SIG_ERR) {
+		PARA_EMERG_LOG("failed to ignore SIGUSR1\n");
+		exit(EXIT_FAILURE);
+	}
+	/*
+	 * 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.
+	 */
+	if (signal(SIGCHLD, tmp_sigchld_handler) == SIG_ERR) {
+		PARA_EMERG_LOG("failed to install temporary SIGCHLD handler\n");
+		exit(EXIT_FAILURE);
+	}
 	PARA_NOTICE_LOG("initializing the audio file selector\n");
 	afs_socket = init_afs();
 	init_signal_task();