2 * Copyright (C) 2006-2014 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file dccp_send.c Paraslash's dccp sender. */
10 * based on server.c of dccp-cs-0.01.tar.bz2,
11 * (C) 2005 Ian McDonald <imcdnzl@gmail.com>
15 #include <sys/types.h>
30 #include "close_on_fork.h"
31 #include "chunk_queue.h"
32 #include "server.cmdline.h"
35 static struct sender_status dccp_sender_status, *dss = &dccp_sender_status;
37 struct dccp_fec_client {
38 struct fec_client_parms fcp;
39 struct fec_client *fc;
42 static void dccp_pre_select(int *max_fileno, fd_set *rfds,
43 __a_unused fd_set *wfds)
45 if (dss->listen_fd >= 0)
46 para_fd_set(dss->listen_fd, rfds, max_fileno);
50 * Query the TX CCID used on the sender-client half connection.
51 * \param sockfd Server socket descriptor to query (after accept(2)).
52 * \return CCID number > 0, -1 on error/incompatibility.
54 * NB: This feature is only available on Linux > 2.6.30; on older kernels
55 * ENOPROTOOPT ("Protocol not available") will be returned.
57 static int dccp_get_tx_ccid(int sockfd)
60 socklen_t len = sizeof(tx_ccid);
62 if (getsockopt(sockfd, SOL_DCCP,
63 DCCP_SOCKOPT_TX_CCID, &tx_ccid, &len) < 0) {
64 PARA_WARNING_LOG("DCCP_SOCKOPT_TX_CCID: %s\n", strerror(errno));
70 static void dccp_shutdown_client(struct sender_client *sc)
72 struct dccp_fec_client *dfc = sc->private_data;
74 vss_del_fec_client(dfc->fc);
75 shutdown_client(sc, dss);
78 static void dccp_shutdown_clients(void)
80 struct sender_client *sc, *tmp;
82 list_for_each_entry_safe(sc, tmp, &dss->client_list, node)
83 dccp_shutdown_client(sc);
86 /** * Obtain current MPS according to RFC 4340, sec. 14. */
87 static int dccp_init_fec(struct sender_client *sc)
90 socklen_t ml = sizeof(mps);
92 /* If call fails, return some sensible minimum value */
93 ret = getsockopt(sc->fd, SOL_DCCP, DCCP_SOCKOPT_GET_CUR_MPS, &mps, &ml);
95 PARA_NOTICE_LOG("can not determine MPS: %s\n", strerror(errno));
96 mps = generic_max_transport_msg_size(sc->fd) - DCCP_MAX_HEADER;
98 PARA_INFO_LOG("current MPS = %d bytes\n", mps);
100 if (conf.dccp_max_slice_size_arg > 0)
101 mps = PARA_MIN(mps, conf.dccp_max_slice_size_arg);
105 static void dccp_send_fec(struct sender_client *sc, char *buf, size_t len)
107 int ret = xwrite(sc->fd, buf, len);
110 dccp_shutdown_client(sc);
113 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
115 struct sender_client *sc;
116 struct dccp_fec_client *dfc;
119 sc = accept_sender_client(dss, rfds);
123 /* If CCID identifiable, present client as <host>#<port>~<ccid> */
124 tx_ccid = dccp_get_tx_ccid(sc->fd);
126 char *tmp = make_message("%s~%d", sc->name, tx_ccid);
132 * Bypass unused CCID paths: the sender does not receive application data
133 * from the client; by shutting down this unused communication path we can
134 * reduce processing costs a bit. See analogous comment in dccp_recv.c.
136 if (shutdown(sc->fd, SHUT_RD) < 0) {
137 PARA_WARNING_LOG("%s\n", strerror(errno));
138 shutdown_client(sc, dss);
141 dfc = para_calloc(sizeof(*dfc));
142 sc->private_data = dfc;
143 dfc->fcp.data_slices_per_group = conf.dccp_data_slices_per_group_arg;
144 dfc->fcp.slices_per_group = conf.dccp_slices_per_group_arg;
145 dfc->fcp.init_fec = dccp_init_fec;
146 dfc->fcp.send_fec = dccp_send_fec;
147 dfc->fcp.need_periodic_header = false;
148 dfc->fc = vss_add_fec_client(sc, &dfc->fcp);
151 static int dccp_com_on(__a_unused struct sender_command_data *scd)
153 return generic_com_on(dss, IPPROTO_DCCP);
156 static int dccp_com_off(__a_unused struct sender_command_data *scd)
158 dccp_shutdown_clients();
159 generic_com_off(dss);
164 static int dccp_com_deny(struct sender_command_data *scd)
166 generic_com_deny(scd, dss);
170 static int dccp_com_allow(struct sender_command_data *scd)
172 generic_com_allow(scd, dss);
177 * Return list of available CCIDs or warning, in static buffer.
179 static const char *dccp_list_available_ccids(void)
181 /* Worst case length: n * 3 digits + n-1 spaces + '\0' */
182 static char list[DCCP_MAX_HOST_CCIDS * 4];
186 nccids = dccp_available_ccids(&ccids);
188 snprintf(list, sizeof(list), "Unable to query available CCIDs");
190 for (i = len = 0; i < nccids; i++)
191 len += snprintf(list + len, sizeof(list) - len,
192 "%s%d", i ? " " : "", ccids[i]);
197 static char *dccp_info(void)
199 char *info = get_sender_info(dss, "dccp");
200 char *ret = make_message("%s" "\tsupported ccids: %s\n",
201 info, dccp_list_available_ccids());
207 * The init function of the dccp sender.
209 * \param s pointer to the dccp sender struct.
211 * It initializes all function pointers of \a s and starts
212 * listening on the given port.
214 void dccp_send_init(struct sender *s)
220 s->pre_select = dccp_pre_select;
221 s->post_select = dccp_post_select;
222 s->shutdown_clients = dccp_shutdown_clients;
223 s->resolve_target = NULL;
224 s->help = generic_sender_help;
225 s->client_cmds[SENDER_ON] = dccp_com_on;
226 s->client_cmds[SENDER_OFF] = dccp_com_off;
227 s->client_cmds[SENDER_DENY] = dccp_com_deny;
228 s->client_cmds[SENDER_ALLOW] = dccp_com_allow;
229 s->client_cmds[SENDER_ADD] = NULL;
230 s->client_cmds[SENDER_DELETE] = NULL;
232 k = conf.dccp_data_slices_per_group_arg;
233 n = conf.dccp_slices_per_group_arg;
235 if (k <= 0 || n <= 0 || k >= n) {
236 PARA_WARNING_LOG("invalid FEC parameters, using defaults\n");
237 conf.dccp_data_slices_per_group_arg = 3;
238 conf.dccp_slices_per_group_arg = 4;
241 init_sender_status(dss, conf.dccp_access_arg, conf.dccp_access_given,
242 conf.dccp_port_arg, conf.dccp_max_clients_arg,
243 conf.dccp_default_deny_given);
244 ret = generic_com_on(dss, IPPROTO_DCCP);
246 PARA_ERROR_LOG("%s\n", para_strerror(-ret));