-/*
- * Copyright (C) 2006-2009 Andre Noll <maan@systemlinux.org>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
/** \file dccp_send.c Paraslash's dccp sender. */
* (C) 2005 Ian McDonald <imcdnzl@gmail.com>
*/
+#include <netinet/in.h>
+#include <sys/socket.h>
#include <regex.h>
#include <sys/types.h>
-#include <dirent.h>
-#include <osl.h>
+#include <arpa/inet.h>
+#include <sys/un.h>
+#include <netdb.h>
+#include <lopsub.h>
+#include "server.lsg.h"
#include "para.h"
#include "error.h"
#include "string.h"
#include "afh.h"
-#include "afs.h"
-#include "server.h"
#include "net.h"
+#include "server.h"
#include "list.h"
-#include "vss.h"
#include "send.h"
+#include "sched.h"
+#include "vss.h"
#include "fd.h"
-#include "close_on_fork.h"
-#include "chunk_queue.h"
-#include "server.cmdline.h"
-#include "acl.h"
-
-/** Do not write more than that many bytes at once. */
-#define DCCP_MAX_BYTES_PER_WRITE 1024
static struct sender_status dccp_sender_status, *dss = &dccp_sender_status;
+struct dccp_fec_client {
+ struct fec_client_parms fcp;
+ struct fec_client *fc;
+};
+
static void dccp_pre_select(int *max_fileno, fd_set *rfds,
__a_unused fd_set *wfds)
{
- if (dss->listen_fd >= 0)
- para_fd_set(dss->listen_fd, rfds, max_fileno);
+ unsigned n;
+
+ FOR_EACH_LISTEN_FD(n, dss)
+ if (dss->listen_fds[n] >= 0)
+ para_fd_set(dss->listen_fds[n], rfds, max_fileno);
}
-static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
+/**
+ * Query the TX CCID used on the sender-client half connection.
+ * \param sockfd Server socket descriptor to query (after accept(2)).
+ * \return CCID number > 0, -1 on error/incompatibility.
+ *
+ * NB: This feature is only available on Linux > 2.6.30; on older kernels
+ * ENOPROTOOPT ("Protocol not available") will be returned.
+ */
+static int dccp_get_tx_ccid(int sockfd)
{
- struct sender_client *sc;
+ int tx_ccid;
+ socklen_t len = sizeof(tx_ccid);
- if (dss->listen_fd < 0 || !FD_ISSET(dss->listen_fd, rfds))
- return;
- sc = accept_sender_client(dss);
- if (!sc)
- return;
- /*
- * Bypass unused CCID paths: the sender does not receive application data
- * from the client; by shutting down this unused communication path we can
- * reduce processing costs a bit. See analogous comment in dccp_recv.c.
- */
- if (shutdown(sc->fd, SHUT_RD) >= 0)
- return;
- PARA_WARNING_LOG("%s\n", strerror(errno));
+ if (getsockopt(sockfd, SOL_DCCP,
+ DCCP_SOCKOPT_TX_CCID, &tx_ccid, &len) < 0) {
+ PARA_WARNING_LOG("DCCP_SOCKOPT_TX_CCID: %s\n", strerror(errno));
+ return -1;
+ }
+ return tx_ccid;
+}
+
+static void dccp_shutdown_client(struct sender_client *sc)
+{
+ struct dccp_fec_client *dfc = sc->private_data;
+
+ vss_del_fec_client(dfc->fc);
shutdown_client(sc, dss);
}
-static void dccp_send(long unsigned current_chunk,
- __a_unused long unsigned chunks_sent, const char *buf,
- size_t len, const char *header_buf, size_t header_len)
+static void dccp_shutdown_clients(void)
{
struct sender_client *sc, *tmp;
list_for_each_entry_safe(sc, tmp, &dss->client_list, node)
- send_chunk(sc, dss, DCCP_MAX_BYTES_PER_WRITE, current_chunk, buf,
- len, header_buf, header_len);
+ dccp_shutdown_client(sc);
}
-static void dccp_shutdown_clients(void)
+static void dccp_shutdown(void)
+{
+ dccp_shutdown_clients();
+ generic_acl_deplete(&dss->acl);
+}
+
+/** * Obtain current MPS according to RFC 4340, sec. 14. */
+static int dccp_init_fec(struct sender_client *sc)
{
- shutdown_clients(dss);
+ int mps, ret;
+ socklen_t ml = sizeof(mps);
+ uint32_t mss; /* max slize size */
+
+ /* If call fails, return some sensible minimum value */
+ ret = getsockopt(sc->fd, SOL_DCCP, DCCP_SOCKOPT_GET_CUR_MPS, &mps, &ml);
+ if (ret < 0) {
+ PARA_NOTICE_LOG("can not determine MPS: %s\n", strerror(errno));
+ mps = generic_max_transport_msg_size(sc->fd) - DCCP_MAX_HEADER;
+ }
+ PARA_INFO_LOG("current MPS = %d bytes\n", mps);
+ assert(mps > 0);
+ mss = OPT_UINT32_VAL(DCCP_MAX_SLICE_SIZE);
+ if (mss > 0 && mss <= INT_MAX)
+ mps = PARA_MIN(mps, (int)mss);
+ return mps;
+}
+
+static void dccp_send_fec(struct sender_client *sc, char *buf, size_t len)
+{
+ int ret = xwrite(sc->fd, buf, len);
+
+ if (ret < 0)
+ dccp_shutdown_client(sc);
+}
+
+static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
+{
+ struct sender_client *sc;
+ struct dccp_fec_client *dfc;
+ int tx_ccid;
+ uint32_t k, n;
+
+ sc = accept_sender_client(dss, rfds);
+ if (!sc)
+ return;
+
+ /* If CCID identifiable, present client as <host>#<port>~<ccid> */
+ tx_ccid = dccp_get_tx_ccid(sc->fd);
+ if (tx_ccid != -1) {
+ char *tmp = make_message("%s~%d", sc->name, tx_ccid);
+
+ free(sc->name);
+ sc->name = tmp;
+ }
+ /*
+ * Bypass unused CCID paths: the sender does not receive application data
+ * from the client; by shutting down this unused communication path we can
+ * reduce processing costs a bit. See analogous comment in \ref dccp_recv.c.
+ */
+ if (shutdown(sc->fd, SHUT_RD) < 0) {
+ PARA_WARNING_LOG("%s\n", strerror(errno));
+ shutdown_client(sc, dss);
+ return;
+ }
+ dfc = para_calloc(sizeof(*dfc));
+ sc->private_data = dfc;
+ k = OPT_UINT32_VAL(DCCP_DATA_SLICES_PER_GROUP);
+ n = OPT_UINT32_VAL(DCCP_SLICES_PER_GROUP);
+ if (k == 0 || n == 0 || k >= n) {
+ PARA_WARNING_LOG("invalid FEC parameters, using defaults\n");
+ dfc->fcp.data_slices_per_group = 3;
+ dfc->fcp.slices_per_group = 4;
+ } else {
+ dfc->fcp.data_slices_per_group = k;
+ dfc->fcp.slices_per_group = n;
+ }
+ dfc->fcp.init_fec = dccp_init_fec;
+ dfc->fcp.send_fec = dccp_send_fec;
+ dfc->fcp.need_periodic_header = false;
+ dfc->fc = vss_add_fec_client(sc, &dfc->fcp);
}
static int dccp_com_on(__a_unused struct sender_command_data *scd)
{
- return generic_com_on(dss, IPPROTO_DCCP);
+ generic_com_on(dss, IPPROTO_DCCP);
+ return 1;
}
static int dccp_com_off(__a_unused struct sender_command_data *scd)
{
+ dccp_shutdown_clients();
generic_com_off(dss);
return 1;
}
return 1;
}
-static char *dccp_info(void)
+/**
+ * Return list of available CCIDs or warning, in static buffer.
+ */
+static const char *dccp_list_available_ccids(void)
{
- return get_sender_info(dss, "dccp");
+ /* Worst case length: n * 3 digits + n-1 spaces + '\0' */
+ static char list[DCCP_MAX_HOST_CCIDS * 4];
+ uint8_t *ccids;
+ int i, len, nccids;
+
+ nccids = dccp_available_ccids(&ccids);
+ if (nccids < 0) {
+ snprintf(list, sizeof(list), "Unable to query available CCIDs");
+ } else {
+ for (i = len = 0; i < nccids; i++)
+ len += snprintf(list + len, sizeof(list) - len,
+ "%s%d", i ? " " : "", ccids[i]);
+ }
+ return list;
}
-/**
- * The init function of the dccp sender.
- *
- * \param s pointer to the dccp sender struct.
- *
- * It initializes all function pointers of \a s and starts
- * listening on the given port.
+static char *dccp_status(void)
+{
+ char *status = generic_sender_status(dss, "dccp");
+ char *result = make_message("%ssupported ccids: %s\n", status,
+ dccp_list_available_ccids());
+ free(status);
+ return result;
+}
+
+/*
+ * Initialize the client list and the access control list and listen on the
+ * dccp port.
*/
-void dccp_send_init(struct sender *s)
+static void dccp_send_init(void)
{
- int ret;
-
- s->info = dccp_info;
- s->send = dccp_send;
- s->pre_select = dccp_pre_select;
- s->post_select = dccp_post_select;
- s->shutdown_clients = dccp_shutdown_clients;
- s->help = generic_sender_help;
- s->client_cmds[SENDER_ON] = dccp_com_on;
- s->client_cmds[SENDER_OFF] = dccp_com_off;
- s->client_cmds[SENDER_DENY] = dccp_com_deny;
- s->client_cmds[SENDER_ALLOW] = dccp_com_allow;
- s->client_cmds[SENDER_ADD] = NULL;
- s->client_cmds[SENDER_DELETE] = NULL;
-
- init_sender_status(dss, conf.dccp_access_arg, conf.dccp_access_given,
- conf.dccp_port_arg, conf.dccp_max_clients_arg,
- conf.dccp_default_deny_given);
- ret = generic_com_on(dss, IPPROTO_DCCP);
- if (ret < 0)
- PARA_ERROR_LOG("%s\n", para_strerror(-ret));
+ init_sender_status(dss, OPT_RESULT(DCCP_ACCESS),
+ OPT_RESULT(DCCP_LISTEN_ADDRESS),
+ OPT_UINT32_VAL(DCCP_PORT), OPT_UINT32_VAL(DCCP_MAX_CLIENTS),
+ OPT_GIVEN(DCCP_DEFAULT_DENY));
+ generic_com_on(dss, IPPROTO_DCCP);
}
+
+/**
+ * The DCCP sender.
+ *
+ * This sender offers congestion control not available in plain TCP. Most
+ * methods of the sender structure are implemented as simple wrappers for the
+ * generic functions defined in \ref send_common.c. Like UDP streams, DCCP
+ * streams are sent FEC-encoded.
+ */
+const struct sender dccp_sender = {
+ .name = "dccp",
+ .init = dccp_send_init,
+ .shutdown = dccp_shutdown,
+ .pre_select = dccp_pre_select,
+ .post_select = dccp_post_select,
+ .shutdown_clients = dccp_shutdown_clients,
+ .client_cmds = {
+ [SENDER_on] = dccp_com_on,
+ [SENDER_off] = dccp_com_off,
+ [SENDER_deny] = dccp_com_deny,
+ [SENDER_allow] = dccp_com_allow,
+ },
+ .help = generic_sender_help,
+ .status = dccp_status,
+};