X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=send_common.c;h=43aeb2b3b7597d4d5e46dfc51b036c5868d0cda1;hp=d6c734b5c8bc7cc303252dc9a3debf132a5dc692;hb=335730538150250f32c0df0b184fb494e2bb0df3;hpb=2abba90245f87fab096edfc3faf7df61646b713f

diff --git a/send_common.c b/send_common.c
index d6c734b5..43aeb2b3 100644
--- a/send_common.c
+++ b/send_common.c
@@ -16,16 +16,19 @@
 #include "afh.h"
 #include "afs.h"
 #include "server.h"
+#include "acl.h"
 #include "send.h"
 #include "close_on_fork.h"
 #include "chunk_queue.h"
 #include "vss.h"
 
+/** Clients will be kicked if there are more than that many bytes pending. */
+#define MAX_CQ_BYTES 40000
 
 /**
  * Open a passive socket of given layer4 type.
  *
- * Set the resultig file descriptor to nonblocking mode and add it to the list
+ * Set the resulting file descriptor to nonblocking mode and add it to the list
  * of fds that are being closed in the child process when the server calls
  * fork().
  *
@@ -34,7 +37,7 @@
  *
  * \return The listening fd on success, negative on errors.
  */
-int open_sender(unsigned l4type, int port)
+static int open_sender(unsigned l4type, int port)
 {
 	int fd, ret = para_listen(AF_UNSPEC, l4type, port);
 
@@ -51,15 +54,16 @@ int open_sender(unsigned l4type, int port)
 }
 
 /**
- * Shut down a connected client.
+ * Shut down a client connected to a paraslash sender.
  *
- * \param sc The client to be shut down.
+ * \param sc The client to shut down.
+ * \param ss The sender whose clients are to be shut down.
  *
  * Close the file descriptor given by \a sc, remove it from the close-on-fork
  * list, destroy the chunk queue of this client, delete the client from the
  * list of connected clients and free the sender_client struct.
  */
-void shutdown_client(struct sender_client *sc)
+void shutdown_client(struct sender_client *sc, struct sender_status *ss)
 {
 	PARA_INFO_LOG("shutting down %s on fd %d\n", sc->name, sc->fd);
 	free(sc->name);
@@ -69,6 +73,14 @@ void shutdown_client(struct sender_client *sc)
 	list_del(&sc->node);
 	free(sc->private_data);
 	free(sc);
+	ss->num_clients--;
+}
+
+void shutdown_clients(struct sender_status *ss)
+{
+	struct sender_client *sc, *tmp;
+	list_for_each_entry_safe(sc, tmp, &ss->client_list, node)
+		shutdown_client(sc, ss);
 }
 
 /**
@@ -111,11 +123,12 @@ static int write_nonblock(int fd, const char *buf, size_t len,
 }
 
 static int queue_chunk_or_shutdown(struct sender_client *sc,
-		long unsigned chunk_num, size_t sent)
+		struct sender_status *ss, long unsigned chunk_num,
+		size_t sent)
 {
 	int ret = cq_enqueue(sc->cq, chunk_num, sent);
 	if (ret < 0)
-		shutdown_client(sc);
+		shutdown_client(sc, ss);
 	return ret;
 }
 
@@ -144,6 +157,7 @@ static int send_queued_chunks(struct sender_client *sc,
  * Send one chunk of audio data to a connected client.
  *
  * \param sc The client.
+ * \param ss The sender.
  * \param max_bytes_per_write Split writes to chunks of at most that many bytes.
  * \param current_chunk The number of the chunk to write.
  * \param buf The data to write.
@@ -152,16 +166,19 @@ static int send_queued_chunks(struct sender_client *sc,
  * On errors, the client is shut down. If only a part of the buffer could be
  * written, the remainder is put into the chunk queue for that client.
  */
-void send_chunk(struct sender_client *sc, size_t max_bytes_per_write,
-		long unsigned current_chunk, const char *buf, size_t len)
+void send_chunk(struct sender_client *sc, struct sender_status *ss,
+		size_t max_bytes_per_write, long unsigned current_chunk,
+		const char *buf, size_t len)
 {
 	int ret;
 
 	if (!sc->header_sent && current_chunk) {
 		size_t header_len;
-		char *header_buf = vss_get_header(&header_len);
+		char *header_buf;
+
+		vss_get_header(&header_buf, &header_len);
 		if (header_buf && header_len > 0) {
-			ret = queue_chunk_or_shutdown(sc, -1U, 0);
+			ret = queue_chunk_or_shutdown(sc, ss, -1U, 0);
 			if (ret < 0)
 				goto out;
 		}
@@ -169,23 +186,233 @@ void send_chunk(struct sender_client *sc, size_t max_bytes_per_write,
 	}
 	ret = send_queued_chunks(sc, max_bytes_per_write);
 	if (ret < 0) {
-		shutdown_client(sc);
+		shutdown_client(sc, ss);
 		goto out;
 	}
 	if (!len)
 		goto out;
 	if (!ret) { /* still data left in the queue */
-		ret = queue_chunk_or_shutdown(sc, current_chunk, 0);
+		ret = queue_chunk_or_shutdown(sc, ss, current_chunk, 0);
 		goto out;
 	}
 	ret = write_nonblock(sc->fd, buf, len, max_bytes_per_write);
 	if (ret < 0) {
-		shutdown_client(sc);
+		shutdown_client(sc, ss);
 		goto out;
 	}
 	if (ret != len)
-		ret = queue_chunk_or_shutdown(sc, current_chunk, ret);
+		ret = queue_chunk_or_shutdown(sc, ss, current_chunk, ret);
 out:
 	if (ret < 0)
 		PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
 }
+
+/**
+ * Initialize a struct sender status.
+ *
+ * \param ss The struct to initialize.
+ * \param access_arg The array of access arguments given at the command line.
+ * \param num_access_args The number of elements in \a access_arg.
+ * \param port The tcp or dccp port to listen on.
+ * \param max_clients The maximal number of simultaneous connections.
+ * \param default_deny Whether a blacklist should be used for access control.
+ */
+void init_sender_status(struct sender_status *ss, char **access_arg,
+	int num_access_args, int port, int max_clients, int default_deny)
+{
+	ss->listen_fd = -1;
+	INIT_LIST_HEAD(&ss->client_list);
+	ss->port = port;
+	acl_init(&ss->acl, access_arg, num_access_args);
+	ss->num_clients = 0;
+	ss->max_clients = max_clients;
+	ss->default_deny = default_deny;
+}
+
+/**
+ * Return a string containing the current status of a sender.
+ *
+ * \param ss The sender.
+ * \param name Used for printing the header line.
+ *
+ * \return The string printed in the "si" command.
+ */
+char *get_sender_info(struct sender_status *ss, char *name)
+{
+	char *clnts = NULL, *ret;
+	struct sender_client *sc, *tmp_sc;
+
+	char *acl_contents = acl_get_contents(&ss->acl);
+	list_for_each_entry_safe(sc, tmp_sc, &ss->client_list, node) {
+		char *tmp = make_message("%s%s ", clnts? clnts : "", sc->name);
+		free(clnts);
+		clnts = tmp;
+	}
+	ret = make_message(
+		"%s sender:\n"
+		"\tstatus: %s\n"
+		"\tport: %d\n"
+		"\tnumber of connected clients: %d\n"
+		"\tmaximal number of clients: %d%s\n"
+		"\tconnected clients: %s\n"
+		"\taccess %s list: %s\n",
+		name,
+		(ss->listen_fd >= 0)? "on" : "off",
+		ss->port,
+		ss->num_clients,
+		ss->max_clients,
+		ss->max_clients > 0? "" : " (unlimited)",
+		clnts? clnts : "(none)",
+		ss->default_deny? "allow" : "deny",
+		acl_contents? acl_contents : "(empty)"
+	);
+	free(acl_contents);
+	free(clnts);
+	return ret;
+}
+
+/**
+ * Allow connections from the given range of IP addresses.
+ *
+ * \param scd Contains the IP and the netmask.
+ * \param ss The sender.
+ *
+ * \sa generic_com_deny().
+ */
+void generic_com_allow(struct sender_command_data *scd,
+		struct sender_status *ss)
+{
+	acl_allow(scd->addr, scd->netmask, &ss->acl, ss->default_deny);
+}
+
+/**
+ * Deny connections from the given range of IP addresses.
+ *
+ * \param scd see \ref generic_com_allow().
+ * \param ss see \ref generic_com_allow().
+ *
+ * \sa generic_com_allow().
+ */
+void generic_com_deny(struct sender_command_data *scd,
+		struct sender_status *ss)
+{
+	acl_deny(scd->addr, scd->netmask, &ss->acl, ss->default_deny);
+}
+
+/**
+ * Activate a paraslash sender.
+ *
+ * \param ss The sender to activate.
+ * \param protocol The symbolic name of the transport-layer protocol.
+ *
+ * \return Standard.
+ */
+int generic_com_on(struct sender_status *ss, unsigned protocol)
+{
+	int ret;
+
+	if (ss->listen_fd >= 0)
+		return 1;
+	ret = open_sender(protocol, ss->port);
+	if (ret < 0)
+		return ret;
+	ss->listen_fd = ret;
+	return 1;
+}
+
+/**
+ * Deactivate a paraslash sender.
+ *
+ * Shutdown all connected clients and stop listening on the TCP/DCCP socket.
+ *
+ * \param ss The sender to deactivate.
+ *
+ * \sa \ref del_close_on_fork_list(), shutdown_clients().
+ */
+void generic_com_off(struct sender_status *ss)
+{
+	if (ss->listen_fd < 0)
+		return;
+	PARA_NOTICE_LOG("closing port %d\n", ss->port);
+	close(ss->listen_fd);
+	del_close_on_fork_list(ss->listen_fd);
+	shutdown_clients(ss);
+	ss->listen_fd = -1;
+}
+
+/**
+ * Accept a connection on the socket this server is listening on.
+ *
+ * \param ss The sender whose listening fd is ready for reading.
+ *
+ * This must be called only if the socket fd of \a ss is ready for reading.  It
+ * calls para_accept() to accept the connection and performs the following
+ * actions on the resulting file descriptor \a fd:
+ *
+ *	- Checks whether the maximal number of connections are exceeded.
+ *	- Sets \a fd to nonblocking mode.
+ *	- Checks the acl of the sender to find out whether connections
+ *	  are allowed from the IP of the connecting peer.
+ * 	- Increases the number of connections for this sender.
+ *	- Creates and initializes a new chunk queue for queuing network
+ *	  packets that can not be sent immediately.
+ *	- Allocates a new struct sender_client and fills in its \a fd, \a cq
+ *	  and \a name members.
+ *	- Adds \a fd to the list of connected clients for this sender.
+ *	- Adds \a fd to the list of file descriptors that should be closed
+ *	  in the child process when the server calls fork().
+ *
+ * \return A pointer to the allocated sender_client structure on success, \p
+ * NULL on errors.
+ *
+ * \sa \ref para_accept(), \ref mark_fd_nonblocking(), \ref acl_check_access(),
+ * \ref cq_new(), \ref add_close_on_fork_list().
+ */
+struct sender_client *accept_sender_client(struct sender_status *ss)
+{
+	struct sender_client *sc;
+	int fd, ret = para_accept(ss->listen_fd, NULL, 0);
+	if (ret < 0) {
+		PARA_ERROR_LOG("%s\n", para_strerror(-ret));
+		return NULL;
+	}
+	fd = ret;
+	ret = -E_MAX_CLIENTS;
+	if (ss->max_clients > 0 && ss->num_clients >= ss->max_clients)
+		goto err_out;
+	ret = mark_fd_nonblocking(fd);
+	if (ret < 0)
+		goto err_out;
+	ret = acl_check_access(fd, &ss->acl, ss->default_deny);
+	if (ret < 0)
+		goto err_out;
+	ss->num_clients++;
+	sc = para_calloc(sizeof(*sc));
+	sc->fd = fd;
+	sc->name = make_message("%s", remote_name(fd));
+	sc->cq = cq_new(MAX_CQ_BYTES);
+	para_list_add(&sc->node, &ss->client_list);
+	add_close_on_fork_list(fd);
+	PARA_INFO_LOG("accepted client #%d: %s (fd %d)\n", ss->num_clients,
+		sc->name, fd);
+	return sc;
+err_out:
+	PARA_WARNING_LOG("%s\n", para_strerror(-ret));
+	close(fd);
+	return NULL;
+}
+
+/**
+ * Get the generic help text.
+ *
+ * \return A dynamically allocated string containing the help text for
+ * a paraslash sender.
+ */
+char *generic_sender_help(void)
+{
+	return make_message(
+		"usage: {on|off}\n"
+		"usage: {allow|deny} IP mask\n"
+		"example: allow 127.0.0.1 32\n"
+	);
+}