+
+/**
+ * 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, const 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->host, 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->host, 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[/netmask]\n"
+ " where mask defaults to 32\n"
+ "example: allow 192.168.0.1/24\n"
+ );
+}
+
+static int parse_fec_parms(const char *arg, struct sender_command_data *scd)
+{
+ int32_t val;
+ char *a = para_strdup(arg), *b = a, *e = strchr(b, ':');
+ int ret = -E_COMMAND_SYNTAX;
+
+ /* parse max slice bytes */
+ if (!e)
+ goto out;
+ *e = '\0';
+ ret = para_atoi32(b, &val);
+ if (ret < 0)
+ goto out;
+ ret = -ERRNO_TO_PARA_ERROR(EINVAL);
+ if (val < 0 || val > 65535)
+ goto out;
+ scd->max_slice_bytes = val;
+ /* parse data_slices_per_group */
+ b = e + 1;
+ e = strchr(b, ':');
+ ret = -E_COMMAND_SYNTAX;
+ if (!e)
+ goto out;
+ *e = '\0';
+ ret = para_atoi32(b, &val);
+ if (ret < 0)
+ goto out;
+ ret = -ERRNO_TO_PARA_ERROR(EINVAL);
+ if (val < 0 || val > 255)
+ goto out;
+ scd->data_slices_per_group = val;
+ /* parse slices_per_group */
+ b = e + 1;
+ ret = para_atoi32(b, &val);
+ if (ret < 0)
+ goto out;
+ ret = -ERRNO_TO_PARA_ERROR(EINVAL);
+ if (val < 0 || val < scd->data_slices_per_group)
+ goto out;
+ scd->slices_per_group = val;
+ ret = 0;
+out:
+ free(a);
+ return ret;
+}
+
+/**
+ * Parse a FEC URL string.
+ *
+ * \param arg the URL string to parse.
+ * \param scd The structure containing host, port and the FEC parameters.
+ *
+ * \return Standard.
+ *
+ * A FEC URL consists of an ordinary URL string according to RFC 3986,
+ * optionally followed by a slash and the three FEC parameters slice_size,
+ * data_slices_per_group and slices_per_group. The three FEC parameters are
+ * separated by colons.
+ *
+ * \sa \ref parse_url().
+ */
+int parse_fec_url(const char *arg, struct sender_command_data *scd)
+{
+ int ret;
+ ssize_t len = sizeof(scd->host);
+ char *a = para_strdup(arg), *p = strchr(a, '/');
+
+ if (p) {
+ *p = '\0';
+ len = strlen(a);
+ }
+ ret = -ERRNO_TO_PARA_ERROR(EINVAL);
+ if (!parse_url(a, scd->host, len, &scd->port))
+ goto out;
+ if (p) {
+ ret = parse_fec_parms(p + 1, scd);
+ goto out;
+ }
+ /* use default fec parameters. */
+ scd->max_slice_bytes = 1490;
+ scd->slices_per_group = 16;
+ scd->data_slices_per_group = 14;
+ ret = 0;
+out:
+ free(a);
+ return ret;
+}